4761 4765.output

* GB785168 (A)

Description: GB785168 (A) ? 1957-10-23

Oil-collector to prevent loss of oil in rotary high-vacuum pumps

Description of GB785168 (A)

PATENT SPECIFICATION 785,168 f i Date of Application and filing Complete Specification: Dec 6, 1955. No 34977155. Application made in Germany on Dec 6, 1954. Complete Specification Published: Oct 23, 1957. Index at acceptance:-Class 110 ( 2), A 2 E. International Classification:-FO 5 g. COMPLETE SPECIFICATION Oil-collector to Prevent Loss of Oil in Rotary High-vacuum Pumps We, E LEYBOLD'S NACHFOLGER, of 504, Bonner Strasse, Koln-Bayental, Germany, a German Body Corporate, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement:- This invention relates to oil-sealed rotary vacuum pumps which have an exhaust valve surrounded by a housing which is partly filled with oil so as to cover the valve The oil seal is essential if a high vacuum is desired. But since the exhausted gas has to pass through a layer of oil before it is free to escape or to enter the discharge pipe, it is unavoidable that in the case of high deliveries, for instance at the beginning of the evacuation or if it is desired to operate the vacuum pump as a compressor, oil particles are entrained by the gas stream and are carried away into the discharge pipe This is the reason why the mentioned rotary pumps, when used as compressors, are operated without sealing oil for their delivery valve. It is the object of the present invention to improve the construction of oil-sealed rotary vacuum pumps so as to reduce as far as possible oil losses during starting of the evacuation or when it is desired to

use these pumps as compressors. Many suggestions were made in the past to prevent the oil from escaping, i e to reduce the loss of oil. For instance, a system of baffle plates were arranged in the housing which surrounds the exhaust valve so as to impart a multiple acute-angled deflection to the gas stream and to precipitate the entrained oil on the walls of the baffle plates However, in order to obtain a satisfactory result, it was necessary to make the housing rather large in order to keep the velocity of the gas small, and the large housing forms a large cooling surface which involves the danger of low wall tenlPrice 3 s 6 d l peratures and condensation of vapours particularly in the case of gas-ballast pumps. With large pumps, which have a comparatively large oil supply in the housing, it has been proposed to surround the exhaust valve 50 by a wall extending from the body of the pump and open at the top so as to produce an annular chamber for the oil Small holes are provided in the said wall near the bottom thereof through which the oil could pass 55 into the inner chamber formed by the wall. This arrangement prevents excessive quantities of oil from flowing over the valves It cannot, however, prevent oil from still entering the valve chamber and being with 60 drawn in the exhaust with high deliveries. In contrast to the known arrangements, a rotary vacuum pump with oil-covered exhaust valve surrounded by a housing which has a discharge opening forthe delivered 65 air and is adapted to receive a supply of oil, is characterized according to the invention in that within the said housing the exhaust valve is surrounded by a casing which is smaller than the housing, which easing has 70 at its upper end opposite to the exhaust valve a restricted discharge opening and which is provided with several small openings in the lateral wall near the exhaust valve. The restricted discharge opening of the 75 inner casing will be advantageously so dimensioned that at high deliveries of the pump the pressure within the inner casing is so much higher than in the space between this casing and the housing that the oil is 80 prevented to flow into the inner casing through the small opening near the lower end thereof. In order that the invention may be clearly understood, it will now be described with 85 reference to the accompanying drawing which shows diagrammatically by way of example an exhaust valve of a high-vacuum pump. As shown, the valve 1 is surrounded by 90 a housing 6 which merges at the top into an exhaust pipe Within the housing 6, the valve 1 is surrounded by a casing 2 which is substantially smaller than the

housing; it thus forms together with the housing an annular chamber which is filled with oil The casing 2 has at its upper end opposite to the exhaust valve a restricted discharge opening 5, and it is provided with several openings 3 near its bottom, i e near the exhaust valve A baffle plate 4 is provided within the housing 6 above the restricted opening 5 of the inner casing 2 The height of the inner casing 2 is such that the oil supply in the annular space between this casing and the outer housing may amount to more than half of the height of the outer housing as shown. The restricted discharge opening 5 of the inner casing 2 is so dimensioned that at high deliveries of the pump the pressure within the inner casing 2 is so much higher that in the space between this casing and the housing 6 that the oil is prevented to flow into the inner casing through the small openings 3 near the lower end thereof. As a result of the described construction the following is achieved: (a) With increasing delivery, an increasing excess pressure is produced in the inner casing 2, which excess pressure increasingly prevents the oil from flowing back into the casing 2 through the holes 3, i e I as the exhaust pressure increases, the valves are covered with less and less oil and thus less and less oil can be entrained This excess pressure is so determined that the valves are still adequately covered with oil when the vacuum pump is reaching end vacuum with gas -40 ballast At full suction power, no more oil flows into the collector casing. (b) At the restriction 5, oil withdrawn from the interior of the pump, enters at a high velocity the chamber formed by the housing 6 where there is a lower velocity of flow, and, being diverted by the baffle plate 4, is reliably precipitated in the oil supply or on the walls of the housing 6. (c) The oil level can amount to more than half the height of the casing 6 As a result, 50 a large oil supply and sufficient heat in the walls of the whole casing 6 are ensured.

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* GB785169 (A)

Description: GB785169 (A) ? 1957-10-23

Redox type polymerization


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PATENT SPECIFICATION 7853169 Date of Application and filing Complete Specification: Dec 13, 1955. No 35797/55. Application made in Canada on Dec 14, 1954. Complete Specification Published: Oct 23, 1957. Index at acceptance:-Class 2 ( 6), P 2 D( 1 A: 1 X), P 2 K( 7: 8), P 2 PI(B: El: F), P 2 P 2 (A 1: A 3: A 4: X), P 2 P 4 A, P 7 (D 2 A 1: K 2), P 7 P 1 (B: El), P 7 P 2 (A 1: A 3: A 4: X), P 7 P 4 A, P 8 (D 3 A: K 2), P 8 P 1 (B; El; F), P 8 P 2 (A 1; A 3; A 4; X), P 8 P 4 A, International Classification -CO 8 d, f, COMPLETE SPECIFICATION Redox Type Polymerization We, POLYMER CORPORATION LIMITED, a comnpany organised under the laws of Canada, of Sarnia, Ontario, do' hereby declare the invention, for which we pray that a patent may be granted to us and the method by which it is I to be performed, to be particularly described, in and by the following statement:- This invention relates to low temperature redox type polymerization of conjugated diolefins containing from 4 -toi 12 carbon atoms. Such, polymerization includes straight polymerization of the diolefins

themselves or copolymerization of the diolefins with copolymerizablb cornpounds. Low temperature polymerization, e g below C, is new preferred toi polymerizations taking place at elevated temperatures because the resultant polymers have superior physical properties The reactions are of the redox. type, and hence the polymerization formula contains an oxidizing agent, a reducing agent and an oxidation catalyst. The oxidizing agent is usually a peroxide or a hydroperoxide Suitable oxidants would be inorganic preroxidles such as hydrogen peroxide, a penitrate, -a persulphate and a permanganate, or organic peroxides such as benzoyl peroxide, or organic hydropleoxidts such asi tertiary butyl hydroperoxide, metyli cyclohiexyly hydroperoxide, cumene hydro, peroxide and diisopropylbenzene hydroperoxide As, oxidation catalysts, there are used compgunds of a multivalent metal in such a condition that it can change its valence state re Versibly The compounds normally used are those of metals such as iron, cobalt, nickels manganese or copper The reducing agent normally used is an easily oxidizablo organic compound, such as a reducing sugar Sodium fonnaldiehyde sulphoxylate has recnly come, into wide-spread use 'for this, purpose. In the usual rtedox system, for example with ferrous iron oxidation catalyst and a monohydrlopetoxide oxidizing agent, the polymerizationi' of the mionomers is, initiated by a reaction between a complex of -the ferrous iron and the nmonohydroperoxide resulting in the release of free radicals (A free radical:is defined as an) unsaturated molecular fragment in which sonm of the va Lence electrons remain 50 free, that is, do' not partake in bonding) These free radicals then cause thej polymerization. However, it has been found that most of the hydroperoxides used suffer from a number of defects when used according voi this scheme 55 It has been found that at low temperatures some hydroperoxddes doi not react satisfactorily with the comlex of ferrous iron so that an inadequate amount of fe radicals arc produced In other cases the hydroperoxides de 60 compose at higher temperature so that the free radicals are produced too abundantly. -These free radicias do, not effect prolymierization, but react with themselves until all the lhydroperoxide is used up= 65 Even N cases where the release of free -radicals from the hydroperoxidie is adequate, other factors comre intol play to cause unsatisofactory results There are -side reactions which tend to have an adverse effect on the polymer 70 ization There are four ways in which these free radicals may react: they may react the preferred way causing polymerization of the monomer; they may react with themselves thus

-depleting the supply; they may react 75 with the ferrousi iron caidation catalyst; or they may react withb-the parent hydroperoxide. In tfie last three cases the polymerization, is reduced dhe to the wastage of free radicals. There are a number of means of redtcing 80 th 5 e wastage, but all of them include theo imposition of fairly rigid and exprensive requirements on the piolynienzation flormula These mens IM lu the use of an emulsifying agent. This brings appreciable amounts of Othe mono 85 mers into the aqueous phase and hence increases the chanced of collisions between free radicals and monomcr molecules whi Ch cause reaction. The attackof the free tadicals N the ferrous 90 iron can be minimized by keeping the ferrous iron concentration low relative to thle nono1 i -1 i i 1 1 1 1 1 i i =mer concentration in the aqueous phase This may be accomplished by the use of an expensive sequestering agent (A sequestering agent is defined as a suistance which forms a complex sompound, complex ionr or other aggregate with a metal or a metallic compound, commonly with a mntallic ion, and: thereby modifies the action of the ion or compound. Many, but not all, sequestering agents, owe t 10 heir action toi the formation of chelate coniipounds) Some examples: of sequestering agents are ethylenedamnetetraacetic acid and its sodium salts, triplyplhosphates, citrates, ori po um, pyrphosphate The product of ithe sequestering agent andi the ferrous iron has a very low dissociation constant and, thereforem, permits only a small quantity of ferrous iron to be present in the ionized sate. According to the present invention the difficultes inherent in the above described redox type reactionsl are overcome by using difiopropylbenene dihydroperoxide as the oxidizing agent It is prederablei that at least 0 01 parts of this dihlydroperoxide be used per 100 parts by weight of the polymerizable starting materials The upper limit is not theoretically critical, but it is undesirable to have ftee dihydroperoxide in the final product. Thusi O 5 parts is a suitable upper limit for the dihydroperoxide,. An indication of the relative efficiency of diisoptopylbenzene dihydropidd as compared with-other peroxide oxidizing agents may be seen by a comparison of relative reaction rates If we let k, be the absolute reaction rate of the free radical towards the ferrous iron, k 2, be the absolute reaction rate of the free radical on the monomer, and k, bu the absolute reaction, rate of the free radical towards the peroxide, we may obtain two; very useful relative reaction rates (The method of determination of these three absolute reaction rate constants is being currently submitted to the Journal of the American Chemical Society in an article by Orr andl Williams).

X ' -' 4 k 2 We may le K 1 =-aiid K =- Thus K :: k, k 3 gives an indication of the preference of attack by free radicals m the monomer rather than to its attack on ferrous iron, and K 2 gives an indication of the preference of attack by free radicals on the monomer rather than the attack on the peroxide. It can be seen that higher values for K 1 and K, indicate a greater probability that polymerization will take place. A comparison of the relative reaction rate constants for various peroxide oxidizing agents in the palymerization of acrylonitrile is given below in Table 1 The temperatures, m degrees C at which the values were deterrpined, are shown in brackets. Peroxide 3 p-ndtoumene hydroperoxide cumene hydroperoxide p-tert-buwtyl cumene iliyd eroxide diisopropylbenzene dihyerxide : TABLE I 1 ( 4 1 X 10 ', 2 ( 40) 1.3 x 10-3 ( 25) 1.1 x I 0-2 ( 20) 8 x 10-' ( 40) 4.0 ( 25) K. 1 x 10 ' ( 40) 6.5 x 10-3 ( 25) 5.5 x 102 ( 20) 8 x 10-2 ( 40) 1.0 ( 25) It can be seem that the values of K 1 and K, are very much higher for diisopropylh enzen dihydroperoxide than -for the other peroxides -tested It is, -therefore, apparent that diisopropylbe-nie dihydroperoxide is vastly superior as an oxidizing agent in the redox -low temperature polymerizations contemplated herein. The polymerizable starting materials suitable for the present invention are those which ar known to be silitable in redox type reactions: As is well knownh butadiene-1,3 is the most suitableconjugatd: diolefia though= higher homologues such as pentadiene, hexadiene, etc, may be used up to dodeeadiene. Suitable copolymerizable compounds are those containing the olefinic linkage CI,= C<, e g. acrylic acid derivatives such as acrylonitrile and vinyl aromatic compounds such as styrene. The following, examples are given to demonstrate the superiority of diisopropylbenzene dihydroperoxide as an oxidizing agent in these low temperatures polymerizations over the catalyst previously used when the various parametric conditions in the process are changed, -785,169, 785,169 EXAMPLE 1. A series of polymerizations were carried out at 550 F, using the following charge recipe All the quantities are expressed as parts by weights. Butadiene 72 Syene 28 Sodium fatty acid soap (e ' sifer) 50 Mied tertiary miercaptan 0 3: Potassium pyroph"ate 0 133 Ferrous sulphate (Fe SO 47 HQ) O 08 Hydroperoxide, oxidizing agent variable Water 180 The efficiency of the polymerization is of monomets converted to polymer in 17

conveniently expressed as percentage conver- houls i S shown in Table II for various sion within a definite thie limit In all the amounts of diisopropylbenzene dihydroperexamples quoted herein, the percentae con oxi& andi diisopropylbenzene hydroperoxide: version is taken at 17 hours The peretapg TABLE II Diisopropylbenzene dihydroperoxide Diisopropylbenzene hydroperoxide Charge (parts by % Conversion in Charge (parts by % Conversion in weight) 17 hours weight) -17 hours 0.02 21 0 02 5 0.04 83 O 04 4 0.06 84 O 06 23 0.08 80 0 08 27 0.10 72 0 10 72 0.14 76 0.17 77 0.20 77 , 1 It can be seen from these results tiet the dihydroperoxidb is, a much better oxidizing agent than the mnohydtoperoxide, especially in conctration ranges of less than 0 10 parts by weight of the total charge recipe when a sodium fatty acid soap is used as an ermulsifier Further, this shows that the sodium soap,, which is cheaper -than the alternative potassium soap, can now be used. Previously, the sodium soap cld not be t 5, used because it formed a thixatropic gel with prior art oxidizing agents which did not emulsify properly. EXAMPLE 2. The comparisons of the efficiencies, of diisopropylbeuzene hydroperoxidl and of diisopropylbenzene dihydroperoxide were continued In this case, the same chargy recipe was used as ig Example 1 above, except that 5.0 pares potassium fatty acid soap, were used as the emulsifier instil of the sodium fatty acid soap The efficiencies of t Be two hydroperoxides, are given in Table III, which shows the percentage conversion of monomers in 17 hours. 10785,169 TALE III' Diisopropylbenzene dihydroperoxide Diisopropylbenzene hydroperoxide Charge (Parts % conversion Charge (Parts % Conversion by weight) in 17 hours by weight) in 17 hours 0.01 23 0.02 90 002 29 0.04 97 O 04 94 _ = 0 06 92 0.20 87, 0, 20 2 91 This data shows that the 4 lihydroperoxtidb is a superior oxidizing agent at low concentrations, about 0 02 parts by weight, even with the potassium fatty aidd soap, as an emulsifier. EXAMPLE 3. It has always been desirable to add an electro Lyte, such as potassium sulphate, to the charge recipe in order to makd the emulsionless viscous and so aid in ithe dissipation of. heat Howerer, upi to) now this involved the disadvantage that the polymerization tended to slow dom -due'to the dissociation of the 1 S electrolyte. A series of polymerizations was carried out using the followit charge iecipe firsldy'with diisopropylbenze dihydroperoxide and then with diisopropylb=nzen hydroperoxide as, the oxidizing agent, using varying quantities The amounts are in; parts by weight.

Butadiene Styrene Potassium fatty acid, soap (emulslifier) Mixed tertiary mercaptan Potassiumn pyrophosphate Ferrous sulphate (Fe SO 4 7 H 00) Potassoum sulphate Oxidizing agent Water 72 5.0 0.3 0.133 0.08 1.0 variable The results are sumnmarized, in Table IV, which shows the effect on the extent of polymenzation of variable amounts of both the monohydkoperoxide and dihydroperoxide oxidizing agent TABLE IV Diisopropylbenzene dihydroperoxide Diisoprolpylbenzene hydropeioxiie Charge (Parts conversion Charge (Parts t/ Conveisibn by weight) in 17 hours by weight) in 17 hours -0 Ai Y-M '-_ 81,, 01-0 24 0.20 100 0 20 70 These results show thst the polmaration, using the dihydoperoxide ws the oxidizing ageni, is inaffeicted by t addition of the eleafrolyte while the polymerization using the -imnohydreperoxide as the oxidizing agent -is greatly reduceds especially at lowconcentations. EXAMPLE 4. Inn order to det&niine the effect of variable amioun P 1 rof igequesterrngtagent on the copolymerization using diisopropylb'enee dihydroperoxidbe as the oxidizing agent, a series of copolymerizations were carried out at 550 F. using the following charge recipe The amounts are in parts by weight. Butadiene 64 Acrylonitrile 36 Nacconol 3 0 Daxad F 11 O 6 -Trisodiunm phosphate -05 = Mixed tertiary mercaptan 0 3 Potdssium pyrophosphate variable Ferrous sulphate (Fe SO 4 7 H O-) 0 08 Diisoproplylbenzene dihydro peroxide ' -: 020 Water 250 4. manufactured by Dewey and Alny Chiemical Co', Cambridge, Mass Daxad' is a Registered Trade Mark. The results of these polymerizations are given in Talble V. Nacconol is an alkyl aryl sulphonate wetting agment manufactured by National Aniline Division, Allied Chemical & Dye, Corporatin, New York, N Y. Daxad 11 is a polymerized sodium salt of alkyl aryl and aryl alkyl sulphonic acids. TABLE V Potassium pyrophosphate charge (parts by weight) % Conversion in 17 hours 0.013 43 0.027 68 0.040 93 0.053 100 0.067 97 0.080 97 This data shows that the conversion, attained in 17 hours is practically insensitive to variations in the amount of sequestering agent when the amount of sequestering agent is greater than about 0 040 pars by weight. Event though the extent of polymerization is low when-the-sequesterig agent concetration is, about 0 013 parts by weight, yet the reaction rate is increased It was found that the 43 % conversion when 0 013-parts sequestering agent was used was accomplished in about 10 hours.

EXAMPLE 5. A series of copolymerizations were carried out similar tot those in Example 4 above except that the potassium pyrophosphate charge was; fixed at O 13 3 parts by weight, and varying amounts of the hydiroperoxide and dihy operoxide were used The results are given in Table VI: TABLE VI q Di'sopopylbenzene dihydroperoxide Diisopropylbenzene hydroperoxide Charge (Parts % conversion Charge (Parts % conversionby weight) in 17 hours by weight) in 17 hours 0,04 100 0 04 90 0.08 100 0 06 98 0.20 100 0 08 95 0.10 96 This data shows that the yiekl of polymer 3 S is indepndent of wide variations in the amount of the dffiydroperoxide, but is somwewhat dependent upon the amount of the monoehydroperoxide. EXAMPLE 6 f One of the principal disadvantages in the copolymerization of butadiene and acrylonitrile gt -low temperature has ben thast the mnalmu rate Oe conversion coincides with the maximum viscosity of the latex A consequefice of thisi condition is that many of the 45 ' reactions, are unontrollable since the exo-. thermic heat of reaction canot be removed' rapidly enough from the viscous solution' An. indication that the maximum rate of conver sion' coincidesi with the nm u viscosity is 50 Phown when a plot of the perea conver85,16, 185,160 sion against timer is a sigmoidal curve Butadiene and acrylonitrile were copolymerized according to the recipe of Example 4 with 0 C 133 parts of portasiunm pyrophosphate and with -first 0 10 parts diisoprbpylbenzene dihydrperoxide and then with 0 20 parts diisop'ropylbenzen dihydroperoxide The copolymerizations were also performed according -to Example 4 except that 0 133 parts potassium pyrzophosphate was used, and also 0 10 parts diisoprop'ylbenztne hydroperoxide and 0 04 par Fe SOQ 7 HO Th results are -phown, in-Tables VII and VIII TABLE VII 0.10 parts, diisopropylbenzene O 20 parts diisopropylbenzenedihydroperoxide, dihydroperoxide Reaction Time % conversion Reaction Time % conversion (hours) (hours) ' 1.75 50 50 19 O 5.0 26 0 8 0 38 0 8.0 34 0 14 0 78 0 14.0 70 0 D:: TABLE VIII 0.10 Parts diisopropylbenzene hydroperoxide Reaction -Time (hrs) Conversion 3.0 8 4 5.0 44 3 0 8.0 _ _ 73 8 11.0 83 6 If these results& are plotted on a graph of % conversion against seaction time, it will be seern that ther pelymerizations using the :dihydroperoxiwd give a linear plot, whereas that using manolhydroperoxide gives a sigmoidal plot It is 1thus evident that -thei use -of the dihydroperoxide results in a controllable piolymerizaticu: It should be mentioned that because diisopropylbfenzene dihydroperoxide is a solid at room teinperature it must ber handled in

a different way from some of the previously used' hydiloperoxides s uch as diisopropylbenzen= hydroperoxi-de which is a liquid The method of using the dihydroperoxide of this invention, which -may be added either as a. powder or as a solution in a non-reactive solvent, -e g ' acetone, will be largely dependent upon the poly aion system used. Seven ( 7) ounce bottles were used for the -polymerizaton of teabove Examples It was found satisfactory to add the di-hydroperoxide in suspension in styrene when the latr is the comonomer In the case of recipes containing acrylonitrile, it was readily 40 dissolved in a portion of the acrylonitrile just -prior to charging it to the bottes Unless this precaution is talemn, the diisopropylbemzene dihydropreroxide reacting with; impurities in the acrylonitrile may bring about polymerization 45 of the acrylontrile before it is charged.


* GB785170 (A)

Description: GB785170 (A) ? 1957-10-23

Polyvinyl acetals

Description of GB785170 (A) Translate this text into Tooltip



O" Ml -w s" r, 1 " k > < t,) And t Na t= 5, " m - Vs \'.,, PATENT SPECIFICATION 785,1 ' Date of Application and filing Complete Specification: Dec IS, 1955. V\) No 36016/55. Application made in United States of America on Dec 15, 1954. Complete Specification Published: Oct 23, 1957. Index at acceptance:-Class 2 ( 6), Pl(D 1 B: P). Internatioial Classification:-CO 81. COMPLETE SPECIFICATION Polyvinyl Acetals We, CELANESE CORPORATION OF Am DERICA, of 180 Madison Avenue, New York 16, New York, 'United States of America, a company incorporated in accordance with the laws of the State of Delaware, United States of America, do hereby declare the invention, for which we pray that a patent may be It has been found according to the present invention that very advantageous results can be obtained by carrying out the acetalization under such conditions that discolouration of the acetal by reaction -with atmospheric oxygen is inhibited. Thus in accordance with one mefhod of ERRATUM SPECIFICATION NO 7857170 Page 4, line 42, for nwashing by,' read Rwashing witli. -THE PATENT OFFICE,2;st A Pril, 11958 l'6 fr fatty -aicid co'ain 8 slhrc''-c Aftei-the astiabeen complet'ea the soluti 6 N is -utiz'd>The polyvinyl acetal is then precipitated from -the solution,' as by the addition'of water, and then washed It has been found that polyvinyl acetals produced in this manner are not entirely suitable for use as moulding materials since they exhibit a tendency to yellow and to become insoluble when moulded or extruded at elevated temperatures Furthermore, the polyvinyl acetals produced in this manner do not have the desired degree of purity It is an object of this invention to provide a new economical and efficient process for the production of polyvnyl acetals which is free from the foreoing a'nd othei disadvantages The invention enables polyvinyl abetals to he' obtained which are' very light 'in colour, do not readily develop colour at moulding temperatures and are of low ash-content: '' lPritg DB 04375/2 ( 9)/Z 601/A 15 C sup'eratmiospheric proissiue as T, pa'ss'e-sover the"'re'cfionfixt A{e' ig 'trlo prvn{ the outside air from entering the system. Pressures of, for 'oekabiple, 0-1 pound per square inch gauge are satisfactory for this purpose If desired, however, higher superatmospheric pressures, subatmospheric pressures or atmospheric pressure may be used, suitable apparatus being employed.

Another method of avoiding discolouration according to the inventioi L, when making a polyvinyl formal is'to 'carry out the formalization reaction in 'the presence of small amounts of 'sodium sulphoxylate formaldehyde Conveniently, the sodium sulphoxylate formaldehyde is' incorporated into the reaction 'mixture eby' ading 'sodim irosulphite (Na SO 4) 'to' said nmixtuie; the reaction of' the ' frialdeliyde' 'with 'the sodium hydrosiilphitie producing sodiumf suilphloxylate for'maldehyde: The formalization reaction in the presence of the S 6 diumi ? PATENT SPECIFICATION 785,170 4 'u Date of Application and filing Complete Specification: Dec 15, 1955. No 36016/55. Application mode in United States of America on Dec 15, 1954. Complete Specification Published: Oct 23, 1957. Indek at acceptance:-Class 2 ( 6), Pl(Dl B: P). International Classification:-C 08 f. COMPLETE SPECIFICATION' Polyvinyl Acetals We, CELANESE CORPORATION OF AMERICA, of 180 Madison Avenue, New York 16, New York, 'Uinited states of America, a company incorporated in accordance with the laws of the State of Delaware, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to the production of polyvinyl acetals. As is well known in the art, polyvinyl acetals are produced by the reaction of aldehydes, such as formaldehyde, with polyvinyl alcohol or esters thereof, such as polyvinyl acetate or polyvinyl propionate, in the presence of acidic catalysts According to one process which has been employed in the art, the polyvinyl acetals are produced by reacting polyvinyl acetate or other polyvinyl ester and formaldehyde, acetaldehyde or other lower aldehyde in solution in an aqueous lower fatty acid containing sulphuric acid. After the reaction has been completed the solution is neutralized The polyvinyl acetal is then precipitated from the solution, as by the addition of water, and then washed It has been found that polyvinyl acetals produced in this manner are not entirely suitable for use as moulding materials since they exhibit a tendency to yellow and to become insoluble when moulded or extruded at elevated temperatures Furthermore, the polyvinyl acetals produced in this manner do not have the desired degree of purity. It is an object of this invention to provide a new economical and efficient process for the production of polyvinyl acetals which is free from the foregoing and other disadvantages The invention enables

polyvinyl acetals to be obtained which are very light in colour, do not readily develop colour at moulding temperatures and are of low ash-content. lPridc It has been found according to the present invention that very advantageous results can be obtained by carrying out the acetalization under such conditions that discolouration of the acetal by reaction -with 50 atmospheric oxygen is inhibited. Thus, in accordance with one method of carrying out the invention such discolouration is avoided by carrying out the acetalization reaction in an atmosphere of an inert gas 55 substantially free from oxygen Inert gases which may be employed in the practice of the invention include nitrogen and carbon dioxide, containing not more than 01 % by volume of oxygen Thus, in one convenient 60 procedure, a stream of purified nitrogen containing less than 0002 % by volume of oxygen is led, before and during the acetalization reaction, over the surface of a reaction miiture comprising polyvinyl ace 65 tate, formaldehyde, aqueous acetic acid and the acetalization catalyst The inert gas is preferably maintained at a slight superatmospheric pressure as it passes over the reaction mixture in order to prevent the 70 outside air from entering the system. Pressures of, for example, 01 pound per square inch gauge are satisfactory fof this purpose If desired, however, higher superatmospheric pressures, subatmospheric pres 75 sures or atmospheric pressure may be used, suitable apparatus being employed. Another method of avoiding discolouration according to the invention, when making a polyvinyl formal is to carry out the forma 80 lization reaction in the presence of small amounts of sodium sulphoxylate formaldehyde Conveniently, the sodium sulphoxylate formaldehyde is incorporated into the reaction mixture by adding sodium hydco 85 sulphite (Na 25204) to said mixture; the reaction of the formaldehyde with the sodium hydrosulphite producing sodium sulphoxylate formaldehyde The formalization reaction in the presence of the sodium 90 7 j 1 1 sulphoxylate formaldehyde may be carried out in air or in an atmosphere of nitrogen or other inert gas The amount of sodium sulphoxylate formaldehyde desirably is in the range of 05 % to 4 % by weight, based on the weight of polyvinyl acetate. In the process of the invention the concentration of the lower fatty acid in the aqueous reaction medium is such that the reaction, mixture is homogeneous, i e the reactants as well as the polyvinyl acetal reaction product are soluble therein Thus, aqueous acetic acid containing 50 to 90 % by weight of acetic acid has been found to be a very suitable reaction medium If desired, other lower saturated fatty acids, such as formic acid, may be used in place of, or in combination with, the acetic acid The proportion of polyvinyl acetate dissolved in

the reaction medium may be varied widely, e g. from 10 to 40 %, by weight, based on the weight of aqueous acetic' acid. With respect to the catalyst employed for effecting the formalization reaction, very good results have been obtained by the use of sulphuric acid, e g in amounts of 1 % to % by weight, based on the weight of aqueous acetic acid Perchloric acid is also a very good catalyst, since when this acid is used the content of bound acid residues of the resulting polyvinyl acetal is extremely small This seems to be due to the fact that when the reaction is carried out in the aqueous lower fatty acid medium the chlorate ion of the perchloric acid is prevented from combining with the polymer molecules, being readily displaced, therefrom by the acetate or other lower fatty acid ion In addition, the rate of formalization when perchloric acid is used as the catalyst is much higher than when sulphuric acid is employed. Thus, a small amount of perchloric acid catalyses the reaction at the same rate as a much larger amount of sulphuric acid. Another acidic catalyst which may be employed in the practice of the invention is a strongly acidic cation-exchange resin such as a cation-exchange resin containing a plurality of sulphonic acid groups Examples of such resins are sulphonated cross-linked water-insoluble polymers such as sulphonated phenol-formaldehyde resins or sulphonated styrenedivinylbenzene copolymers One suitable resin is sold under the name "Permutit Q", which may be activated to the acid form by treatment with sulphuric acid The use of the cationexchange resin as the catalyst permits ready and complete removal of the catalyst from the reaction mixture and avoids any contamination of the polyvinyl acetal by catalyst residues The cation-exchange resin catalyst also lends itself readily to use in continuous processes Thus, in one convenient process polyvinyl acetate, or other polyvinyl fatty acid ester, is dissolved in aqueous acetic acid, together with an excess of formaldehyde, and the resulting solution is blended with fine particles of the cation 70 exchange resin to form a slurry atmospheric oxygen being excluded This slurry is passed continuously through a heated reaction zone, which may be, for example, in the form of a long coiled pipe surrounded by a heating 75 medium such as steam, the rate of flow of the slurry being adjusted so that its residence time in said reaction zone is sufficient to cause the reaction to take place to the desired extent After the stream of slurry 80 emerges from the reaction zone, the particles of cation-exchange resin are continuously separated from the rest of the reaction mixture, as by means of a centrifugal filter, and the separated particles are recycled 85 by admixing them with fresh reactants and reaction medium The cation-exchange resins maintain their activity in such a process for

long periods of time so that little, if any, addition of fresh catalyst or regeneration of 90 spent catalyst is required. Some cation-exchange resins contain colour bodies which may be extracted from the resin and thus colour the resulting polyvinyl acetal during the process In such cases the 95 cation-exchange resin should be pretreated, as by extracting it with the most active solvent portion of the reaction medium, e.g with hot acetic acid at or above the temperature of the acetalization reaction 100 Also, as the resin is recycled in the process the colour bodies thereof are continuously extracted so that the tendency of the resin to colour the product decreases. The acetalization reaction is advant 105 ageously carried out to such an extent as to produce a polyvinyl acetal in which at least 75 %, e g 80 or 83 to 86 %, of the polymer units, i e -H-C 01-12 units, are attached to acetal groups, e g -0-CH 2 110 0 groups, and in which the proportion of polymer units attached to acetate or other ester groups is relatively low, e g less than 17 % preferably about 5 %, the balance of the polymer units being attached to hydroxyl 115 groups At the preferred temperatures of the reaction, i e about 60 to 12000, the reaction times are usually several hours, e.g 8 to 24 hours The amount of formaldehyde present, by weight, is advan 120 tageously 25 % to 35 % based on the weight of the polyvinyl acetate. After the acetalization reaction has been carried out to the desired extent the polyvinyl acetal is recovered from the solution, 125 as by precipitation with a non-solvent therefor, and washed One convenient method of precipitation involves feeding a stream of the reaction mixture and a stream of water into a violently agitated precipitation 130 785,170 chip containing p-t-amyl phenol shows a yellowness coefficient of 0995 while the other chip shows a yellowness coefficient of only 0-46. The following examples, in which all the 70 parts are by weight, illustrate the invention. EXAMPLE 1 parts of the polyvinyl acetate sold under the name "Gelva V 7 " ("Gelva" is a registered trade mark) were dissolved in 75 parts of glacial acetic acid, 6-94 parts of formaldehyde (in the form of formalin of 37 % by weight concentration) and 0-38 parts of sodium hydrosulphite were added to the resulting solution, following which 80 the mixture was heated to 7000 while it was maintained under a stream of purified nitrogen containing less than 0002 % by volume of oxygen Thereafter there were added 30 parts of concentrated ( 97 %) 85 sulphuric acid and an amount of water sufficient to provide a total of 350 parts of water in the resulting mixture, and the mixture was agitated at a temperature of 7000 under a stream of said purified nitrogen 90.

for 24 hours Thereafter, the sulphuric acid catalyst was neutralized by the addition of 3-6 parts of anhydrous sodium acetate and the resulting mixture was heated at 9500 for 6 hours with agitation under an atmosphere 95 of said purified nitrogen Then the polyvinyl formal was precipitated from the solution in the form of fine particles by continuously mixing a stream of the solution with a stream of deionized water The 100 precipitated polyvinyl formal was filtered soaked in deionized water overnight, again filtered and thereafter mixed with 10 times its weight of a dilute aqueous sodium hydroxide solution having a p Hl of 11-2 105 and containing 40 % by weight of methanol. This mixture was heated for 2 hours at refiux temperature and atmospheric pressure, following which the polyvinyl formal was separated by filtration, washed twice more 110 with water and then slurried in 10 times its weight of deionized water To the resulting slurry there was added 05 %, based on the weight of the polyvinyl formal, of di-tertiary butyl p-cresol, in the form of 115 a 5 % solution thereof in ethanol while the slurry was stirred for 20 minutes Thereafter the slurry was filtered and dried in an air oven at 6000 for 24 hours Analysis of the product showed that 105 % ofthe polymer 120 units were attached to hydroxyl groups, 5.2 % to acetate groups and 843 % to formal radicals (i e the degree of formallization was 843 %), the ash content was 0-08 %, the total sulphate content was 0116 % 125 and the soluble sulphate content was 0-048 %, the bound or combined sulphate content being therefore 0068 % The product was moulded in a Carver press for 15 minutes at 2400 C into a disk 0-060 in thickness This 130 zone to form fine particles of the polyvinyl acetal. When the catalyst used is sulphuric acid, it is advantageous, before precipitation, to incorporate an alkali metal salt of a lower fatty acid in the reaction mixture and to heat the resulting mixture for a period of several hours, preferably at a temperature of 60 to 13000 for a period of 1 to 6 hours or more, while the polyvinyl acetal remains dissolved in said reaction mixture. The use of this procedure effects a considerable reduction in the combined sulphate content and colour-forming tendencies of the polyvinyl acetal, in an efficient and economical manner Suitable amounts of the alkali metal salt of the lower fatty acids are, for example, 0 7 to 1 1 equivalents per equivalent of sulphuric acid The alkali metal salt of the lower fatty acid may be incorporated into the reaction mixture in any convenient manner Thus, sodium acetate, as such, may be added to the reaction mixture or the sodium acetate may be incorporated by the addition of sodium hydroxide to a reaction mixture containing acetic acid Similarly, when the reaction medium is

an aqueous formic acid, it is most convenient to incorporate an alkali metal formate rather than the sodium, or other alkali metal, acetate into the reaction mixture In place of, or in addition to, the alkali metal salt of the lower fatty acid, the alkali metal (e g sodium or potassium) thiocyanates, thiosulphates and thiophosphates may be employed It is advantageous to carry out the heating of the solution containing the alkali metal salt while the solution is in an inert atmosphere. After the precipitation and washing, the polyvinyl acetal is dried in air or in vacuo An antioxidant should be added to-the polyvinyl acetal before drying, particularly when the drying is carried out in air, in order to prevent development of colour in the product Especially good results are obtained by the use as the antioxidant of 2,6-dialkyl phenols and 2,4,6-trialkyl phenols, preferably having tertiary alkyl groups, e g. tertiary butyl or tertiary amyl groups, in the 2 and 6 positions, for example, 2,6-di-t-butyl-pcresol It has been suggested in the art that p-t-amyl phenol be employed as an antioxidant in the drying operation However, it has been found in the practice of this invention that the use of p-t-amyl phenol leads to much greater colour formation than the aforementioned 2,6-dialkyl and 2,4,6-trialkyl phenols For example, when two otherwise identical portions of a polyvinyl formal resin, one containing 1 % of p-t-amyl phenol and the other containing 1 % of 2,6-di-t-butyl-p-cresol are dried in air at 60 TC for 96 hours and then moulded at 24000 into chips 0060 inches thick, the 785,170 disk transmitted 859 % of the incident light having a wavelength of 640 mt, and its yellowness coefficient was 012 % The yellowness coefficient is defined by the formula 1 % light transmission at 440 mjt % light transmission at 640 mrat EXAMPLE 2 Example 1 was repeated except that the 1 = 0 sulphuric acid was replaced by an equal weight of perchloric acid The polyvinyl formal was of good colour and low ash content; 859 % of its polymer units were attached to formal radicals, 87 % to hydroxyl groups, and 54 % to acetate radicals. EXAMPLE 3 A mixture of 88-9 parts of glacial acetic acid, 11 1 parts of water, 19-8 parts of the polyvinyl acetate known as "Gelva V 15 ", 8-85 parts of formaldehyde and 4-05 parts of perchloric acid were heated at 700 G with agitation for 24 hours, then neutralized with ammonia water at 700 C, and thereafter precipitated in water with agitation The precipitated polyvinyl formal was separated from the mother liquor, slurried in deionized water, filtered, slurried in dilute aqueous sodium hydroxide solution having a p H of 9 and then washed for one hour in a stream of tap water On moulding into a disk 0-060 inches in

thickness at 2400 C for 15 minutes the product turned light yellow in colour Its ash content was only 002 % and its degree of formalization was 87-3 %. EXAMPLE 4 The spherical granular cation-exchange resin containing sulphonic acid groups having a particle size of 1 to 2 mm and known as "Permutit Q" was activated to its acidic form by stirring it with a large excess of aqueous 5 % sulphuric acid for 1 hour followed by washing by deionized water until the inflowing water and outflowing wash water had the same p H A mixture containing 200 parts of the activated resin (weight calculated on a dry basis), 500 parts of the polyvinyl acetate known as "Gelva V 15 ", 1625 parts of glacial acetic acid, 189 parts of formaldehyde, 94 parts of sodium hydrosulphite and 760 parts of water were agitated for 24 hours at 1000 C. The resin was separated from the liquid by centrifugation and reused, and the polyvinyl formal was precipitated from the liquid reaction mixture and washed. EXAMPLE 5 A mixture of 20 parts of polyvinyl acetate, 67 parts of glacial acetic acid, 33 parts of water, 6-6 parts of formaldehyde, 2 parts of perchloric acid and 0-38 parts of sodium hydrosulphite were heated in an atmosphere of purified nitrogen to a temperature of 100 CC, while agitating, for 5 hours The reaction mixture was then neutralized with aqueous sodium hydroxide and sodium acetate and the polyvinyl formal was precipitated by the addition of water The polyvinyl formal was then washed with water, stabilized by treatment with aqueous sodium hydroxide, and mixed with di-t-butyl-p-cresol The 70 degree of formalization of the product was 85.5 %. EXAMPLE 6 Example 1 was repeated except that instead of heating the neutralized reaction 75 mixture for 6 hours at 9500 it was heated for 1 hour at 90 WC and then at 120 to 1300 C. for 4 hours under an atmosphere of nitrogen, containing less than 0002 % by volume of oxygen, under pressure Further treatment 80 was the same as in Example 1 The bound or combined sulphate content of the product was only 001 %.


* GB785171 (A)

Description: GB785171 (A) ? 1957-10-23

Process of coating cathode ray tube screens

Description of GB785171 (A) Translate this text into Tooltip



PATENT SPECIFICATION 785,171 4 i ' Date of Application and filing Complete Specification: Dec 23, 1955. No 36882/55. Application made in United States of America on Dec 27, 1954. Complete Specification Published: Oct 23, 1957. Index at acceptance:-Class 39 ( 1), D'F 1. International Classification:-H Olj. CCOMPLETE SPECIFICATION Process of Coating Cathode Ray Tube Screens We, STANDARD TELEPHONES AND CABLES LIMITED, a British Company, of Connaught House, 63 Aldwych, London, -W.C 2, England, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to the process of coating cathode ray tube screens preparatory to applying a metal backing thereto. In the manufacture of cathode ray tubes, the use of metallized screens, that is the application of a metal backing to the phosphor screen has become wide-spread Aluminium has been the principal metal employed and such screens are usually referred to as "aluminised" screens In the manufacture of such metallized screens it has been

customary first to apply a layer of phosphors to the inside of the glass tube face which, after being dried as by heating, has applied thereon a barrier layer or film upon which in turn there is precipitated, usually by evaporation, a layer of aluminium The barrier layer or film is required for several reasons, Among these is the fact that the phosphor is full of crevices and holes and if the metal were directly applied thereto it would be very uneven and instead of reflecting the light, would diffuse and diffract it It is desired that the final metal film should be similar to a mirror in smoothness and rest on the high points of the irregular surface of the phosphor This is accomplished by providing the thin film barrier layer on the phosphor screen before application of the evaporated metal Several techniques have been used for forming this film, such as applying water and freezing it so as to produce a smooth surface and then applying over the smooth surface a film forming material which is usually organic The water is removed after the film has been set. Another technique is to cover the phosphor lPrice 3 s 6 d l with a shallow level of water and apply an organic solution in drops Usually nitrocellulose in a butyl-alcohol-ether solution is employed and spreads naturally to form a film on the water The water is then slowly 50 removed from the film by a tipping operation so that the film settles on the surface of the phosphor screen Both of the methods just described involve considerable difficulty. Particularly in the first-mentioned process 55 the freezing of the water in the bulb and the removal of the water thereafter introduces many problems In the second method great care must be used in floating the material on the water to form the film, and 60 then removing the water without disturbing the film. An object of the present invention is the provision of an improved, method for metallizing a cathode ray tube screen and particu 65 larly for forming the barrier layer. In accordance with a major aspect of the present invention the compounds used in forming the barrier or boundary layer are water soluble Various water soluble oxy 70 polymers particularly cellulose and polyvinyl compounds, have been found to be especially suitable'for this purpose Cellulose compounds such as sodium carboxymethyl cellulose and methyl cellulose have proven 75 satisfactory Polyvinyls, such as polyvinyl alcohol and polyvinyl acetate have given excellent results These compounds can be used separately or combined in various portions, and also with the addition of a water 80 soluble plasticizer such as glycerin, or polymethacrylic acid These are then dissolved in water The lhickness of the film produced is controlled by controlling the concentration and viscosity of the solution The solution 85 is poured into a bulb containing an air-dried screen so as to avoid

splashing or turbulence, is kept there for a period of time such as for example 5 minutes, and then slowly drained off, the part remaining on the screen being 90 Afl'1 j, S then dried thereby producing a film ready for aluminising. In greater detail a preferred example of the technique for coating the phosphor screen in accordance with the present invention is as follows The bulb or glass tube containing an air-dried screen is placed on a tilt table and the table is tilted from a normal position to an angle of approximately 60 to 70 degrees A mixture or solution of a suitable compound or compounds dissolved in water is prepared as described below. This mixture or solution is slowly poured into the bulb in such a manner as not to cause splashing or turbulence The quantity of mixture used is preferably that which will cover all parts of the screen to a depth of 1/4 inch when the bulb is tilted back to the normal position in which the phosphor has is substantially horizontal After the mixture has been poured the bulb has been tilted back to the normal position and held there for 5 minutes The bulb is then tilted so as to pour off the mixture slowly, the tilting being at an angle such that it takes from 10 to 12 minutes to pour off the excess mixture. The poured-off mixture is caught and may be used again The remainder of the mixture that is on the screen is dried thereby producing a film which is ready for the application of an evaporated metal, such as aluminium. The film thus produced is smooth, tough, compatible with the phosphor screen and suitable for metallizing. Various solutions of water soluble organio compounds have proven satisfactory Four examples are as follows:1 Methyl cellulose and polyvinyl alcohol and distilled water. 2 Sodium carboxymethyl cellulose and polyvinyl alcohol and distilled water. 3 Polyvinyl alcohol and distilled water. 4 Polyvinyl acetate and distilled water. The first solution is prepared as follows: 300 grams of methyl cellulose is mixed with one litre of distilled water, 300 grams of polyvinyl alcohol is mixed with one litre of distilled water and these two solutions are poured together The thickness of the film is controlled by adjusting the weight of the cellulose and alcohol over a narrow range of 280 to 340 grams per litre of water The most satisfactory solution was found to be 300 grams per litre for the alcohol and the cellulose. Solution No 2 is prepared in the same way as No 1: 300 grams sodium carboxymethyl cellulose mixed with a litre of distilled water and 300 grams of polyvinyl alcohol in one litre of distilled water and the two

solutions are mixed together The viscosity is adjusted by varying the weights of the cellulose and alcohol over a range of 200 to 400 grams per litre The most desirable Weight for the particle size of the screen used in one example was found to be 300 grams of the cellulose and 300 grams of the alcohol per litre. The third solution is made by dissolving 300 grams of polyvinyl alcohol in a litre of distilled water and this gave slightly better 70 results than the mixture of the cellulose and alcohol Again, the viscosity of the solution is adjusted by varying the weight of the polyvinyl alcohol. The fourth solution is prepared by mixing 75 300 grams of polyvinyl acetate in a litre of distilled water and the viscosity is adjusted. With loose control of the temperature and humidity of the atmosphere in the room where the coating operation is performed, 80 it is necessary to make adjustments in the composition of the four solutions for each set of humidity and temperature conditions. The composition of the solution also influences the burn-off time required for the coated 85 screens and should be adjusted to obtain the desired time In general, solutions No 3 and 4 are found to be superior; however, all four solutions, or variations thereof, could be satisfactorily used in coating screens 90 on a production basis after adjustments in the compositions are made to adapt the process for a particular condition encountered in any locality.


* GB785172 (A)

Description: GB785172 (A) ? 1957-10-23

Rigid and impact resistant vinyl halide resin composition


A high quality text as facsimile in your desired language may be available amongst the following family members:

FR1143244 (A) US2956980 (A) FR1143244 (A) US2956980 (A) less Translate this text into Tooltip



PATENT SPECIFICATION 785172 Date of Application and filing Complete Specification: Dec 28, 1955. No 37128/55. Application made in United States of America on June 29, 1955. 3 i Complete Specification Published: -Oct 23, 1957. Index at acceptane Class 2 ( 6), P 4 A, P 4 C( 2: 8 B: 13 C: 18: 20 A), P 4 (D 3 B 1: K 10), P 7 A, P 7 C( 2: 8 B: 13 C: 18: 20 A), P 7 D 1 A, P 7 T 2 (D: E), P 8 A, P 8 C( 2: 8 B: 13 C: 18: 20 A), P 8 (D 2 A: K 1 O), -P 9 A, P 9 C( 2: 8 B: 13 C: 18: 20 A), P 9 (D 1 81: K 10), P 10 A, P 1 OC( 2: 8 B: 13 C: 18: 20 A)i Pl OD( 1 A: 2 A), P 1 OK( 4: 8: 9:10). International Classification:-CO 8 f. COMPLETE SPECIFICATION Rigid' and Impact Resistant Vinyl Halide Resin Composition We, THE GOODYEAR Ti RB & RUBBER COM tion comprises a blend or mixture of a vinyl PANY, a corporation organized under the Laws halide resin and a minor amount of chloroof the-State of-Ohio, United States of America, sulfonated polyethylene rubber The vinyl with offices at 1144 East Market Street, Akron, halide resins as a class are found to be Ohio, United States of America, do hereby improved in regard to these properties,, par 50 declare the invention, for which we pray that ticularly impact strength Examples of vinyl a patent may be granted to us, and the method halide resins so improved include polyvinyl by which it is to be performed, to be particu chloride, the copolymers of vinyl chloride with larly described in and by the following vinylidene chloride, with diethyl maleate, with statement: vinyl acetate, and with diethyl acrylate in 55 This invention relates to a -thermoplastic and which the vinyl

chloride monomer is used in rigid vinyl halide resin compound having a amount from about 80 to 95 % by weight high resistance to fracture when subjected to a based on the total weight of monomers severe shock: present Specific copolymers representative of Vinyl halide resins, particularly polyvinyl the vinyl halide resin that may be used include 60 chloride, have many desirable properties, in the copolymer resulting from, tdie emulsion cluding resistance to abrasion, hardness, ten polymerization of 95 parts of vinyl chloride sile strength, and chemical inertness Polyvinyl and 5 parts of diethyl maleate; the copolymer chloride does not have the desirable property resulting from the emulsion polymerization of of I impact -strength or, in-other words, resis 95 -parts of vinyl chloride and 5 parts of vinyl 65 tance to fracture when subjected to a severe acetate; the copolymer resulting from the emulblow: sion, polymerization of 95 parts of vinyl The object to this invention, therefore, is to chloride and 5 parts of vinylidene chloride; improve the impact strength of polyvinyl the copolymer resulting from the emulsion _ chloride considerably -above one foot pound polymerization of 90 parts of vinyl chloride 70 per inch of notch as determined by the Charpy 'and 10 parts of ethyl acrylate; and the co-Impact Test, without sacrificing the many polymer resulting from the emulsion polyother desirable properties, particularly stiff merization of 80 parts of vinyl chloride and ness and -high heat distortion point, possessed:20 parts of dibutyl maleate. -by polyvinyl chloride The rubbery chlorosulfonated polyethylene 75 It has now been discovered that the object component of this invention is commercially of this invention is obtained when chloro known by the trade name " Hypalon S-2 " isulfonated polyethylene -rubber is blended (Hypalon is a Registered Trade Mark) It is -with the vinyl halide resin, and particularly made by chlorosulfonating normally solid -when blended in amounts from about 8 parts ethylene polymers or interpolymers The 80 -to about 16 parts per -100 parts of resin In typical commercial material contains about addition to producing, a vinyl halide resin 28 % chlorine and 5 % sulfur This material -stock having high impact strength, the stock -is vulcanizable -usually with the aid of metal -also unexpectedly possesses improved plasti oxides, accelerators, -and organic acids. city when used as a hot melt, having, for The vinyl halide resin blends of this inven 85 example, lower Olsen flow values at 1500 tion may be prepared in any suitable manner pouids -per square inch at 180 T 1 C, improved using common-mixing equipment, including toughness and increased transluscency in roll mills or internal mixers Control of temmilled sheet form peratures in the processing of the elastomer The plastic resin composition of this inven and the resinous materials is

important in order 90 to properly flux and disperse the components fluxed, fillers, plasticizers, vulcanization agents of the blend A practical procedure involves when desired, colouring agents, lubricants, and 10 first fluxing the vinyl resin -together with a other compounding ingredients, if required, heat stabilizer on the rolls of a mill at a term are then added and homogeneously blended perature ranging from 300 F to 3750 F, into the mixture followed byithe addition of the elastomer The following formulation is typical for After the resin and elastomer components are making the blend of the present invention, all 15 homogeneously dispersed and thoroughly -parts being by weight: Polyvinyl chloride 100 parts Heat Stabilizer (tin -mercaptide) 2 parts 2 '0 '-X 'Chlorosulfonated Poly ethylene g HypalonS-2) As indicated below Lubricant (Stearic acid) 25 parts Specifically, 100 parts of the polyvinyl stock at 3450 F, a tape was extruded at 3400 35 chloride and two parts of stabilizer were F, and a test piece was injection molded at added to a two-roll mill at 350 F and home 350 ' -F 7 Physical-test specimens were molded geneouslymixectand-ban-dedintoa-continuous -on a plaren press -at 350 F under 1500 psi sheet -to-which was thenw added the thloro pressure for 15 minutes from blends made in sulfonated polyethylenie rubber, and milling accordance with the formulation set forth 40 -30 continued until -the components were homo above and containing -chlorosulfonated polygeneously -blended into a continuous band -ethylene rubber in amounts as indicated below. The -other ingredients were then added until The -following physical properties -were -homogeneously blended mTineasuredon these specimens: Aheet was calendered fromi the resulting -Examples: 1 2 -3 4 5 6 -7 8 9 artsaof cblorosulfonated polye-ethylene c: -e 1 3 5 10 13 15 20 25 Softening Temperature 'C 73 5 f 75 i76 75 73 75:73 5 74 72 Olsen flow in secondsmeasured: at 1500 psi at 1800 C for _ __ _ 12-__ flow: '_ _ _Q___ 102 102 82, 54 17 15 12 6 3 Charpy Impact Strength psi per inch'of notch 5 - 5 5 5 21 22 20 2 5 1 9 Hardness Durometer "D" 77 :1 84:: 85 83 81 78 78 78 74 73 -The-composition of Example 1 ihaving an The blends of this invention are useful in impact strength of -lefs than 1, is easily frac iiidng-plastic-pite, football helmets, shoulder tured and is not useful in applications requir pads, golf club heads, trays, bobbins, electrical ing-resistance to fracture even though the teirfinal>f-blicks, radio cabinets, luggage, 80 composition -has many other desirable phonograph records, and many other applicafeatures -The addition of chlorosulfonatedc tions where resistance to shock and toughness polyethylene rubber to the -vinyl halide resin are -required

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