DE1947924B2 - VlnylcMorMpolymerlsate and process for their production - Google Patents

Description

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Vinyl chloride homopolymers and their copolymers with other ethylenically unsaturated monomers have long been known and are currently used in a wide range of applications by the plastics industry. You can search for different Processes that are described in detail in numerous patents and technical publications »Are written, are made. These processes are generally carried out as bulk or bulk polymerization a monomer or a monomer mixture or as a solution, emulsion or Denotes suspension polymerization in an aqueous medium. In all processes, the polymer tion primarily by bringing the monomers together or the mixture of manomers with suitable polymerization catalysts which generate free radicals accelerated. However, since higher polymer yields are generally more economical and convenient can be generated by the emulsion or suspension process in an aqueous medium these types of processes are mainly preferred in practice for the production of vinyl chloride polymers.

In the previously used aqueous suspension polymerization processes, the vinyl chloride monomer or a mixture with one or more other copolymerizable monomers is brought into contact with a polymerization catalyst which generates free radicals, a suspension which is stable in an aqueous medium being maintained by means of a suspending or dispersing agent. The reaction mixture, which usually fills the reactor by up to 80% by volume, is then kept under a pressure which is established and at different temperatures for different periods of time. The different time periods depend, for example, on the particular catalyst used and the desired average molecular weight. The reaction temperature used is usually between 20 and 100 ° C., preferably between -v and 80 ° C. the reaction time is up to 24 hours or even longer.

More recently, the vinyl chloride graft copolymers are known. These products usually have properties that are somewhat different from the Differentiate vinyl chloride homopolymers or their statistical copolymers. Graft copolymers are mainly made by reacting a polymer in an aqueous suspension with vinyl chloride or a mixture of this compound rr.with another monoethylenically unsaturated compound Monomers produced. Usually this reaction takes place in the presence of a free radical generating connection carried out.

This method is in numerous patents. e.g. in U.S. Patents 3,305,606 and 3,332,858 and British Patents 1,021,324, 1,075,642 and 1,075,643. the The catalysts used are the same as those used for the production of previously known vinyl chloride homo- and copolymers became. The conditions for carrying out the graft polymerization are essentially the same the same as for the preparation of the other polymers, i.e. the graft polymerization generally at temperatures between 20 and 100 ° C., preferably between 20 and 80 ° C., while carried out for a period of around 20 or more hours.

The invention now relates to branched, thermoplastic vinyl chloride _{polymers with CH 3} and 3 to 14 CHjCl end groups on the branches per 1000 CH ₂ groups and a content of at least 50 percent by weight of vinyl chloride units. obtained by suspension polymerization of vinyl chloride, a mixture of vinyl chloride and a comonomer or a mixture of vinyl chloride and a solid polymer graftable with this in the aqueous phase in the presence of monomer-soluble, free radical-forming catalysts at temperatures of 90 to 165 ⁶ C and under increased pressure, the are characterized in that they were obtained by polymerization at hydrostatic pressures of 28 to 350 kg / cm ² maintained throughout the reaction time.

The invention furthermore relates to a process for the production of vinyl chloride polymers, which contain at least 50 percent by weight of vinyl chloride units, by suspension polymerization of vinyl chloride, a mixture of vinyl chloride

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and a Comonorneren or a hybrid »us vinyl chloride and a solid polymer graftable with this in the presence of monomer-soluble, free radical-forming catalysts in the aqueous phase at temperatures from 90 to 165 ° C and under increased pressure, which is characterized in that the polymerization is carried out during the entire reaction time is carried out at hydrostatic pressures of 28 to 350 kg / cm ² .

The polymers according to the invention are distinguished by a special structure, an unexpectedly high one Heat resistance and good processing properties the end.

It is already known. Polymerize vinyl chloride in aqueous suspension in the presence of catalysts which form free radicals at temperatures within the range from 90 to 165 ° C. and high pressures for times within the range from 1 to 12 hours (cf. Journal of Polymer Science. Vol. XLI [1959]) , P. 73 82. especially p. 74, table 1, experiments 1 and 2 and the last two lines before the table). In these known processes, however, if the autoclave is charged with the filling quantities customary for vinyl chloride suspension polymerization and the autogenous pressure is consequently established, a pressure within the range from 28 to 350 kg.cm does not occur during the entire reaction time ² maintained. In this way, polymers are obtained which are inferior to those obtained according to the invention - as the comparative experiments A and B below and FIGS. 1 and 2 show - in terms of heat resistance.

The polymers produced according to the invention can be used for many different plastic applications. The vinyl chloride horn copolymers can be used, for example, as an adhesive, as a flame retardant and as a processing aid in production other polymers can be used. They can also be used as a plastic component in vinyl flooring material as well as in the production of solid vinyl foam.

The statistical copolymers are currently used as process modifiers and as plastic components use in vinyl flooring material and in records. The graft polymers are particularly valuable for making coatings and for various articles that pass through Compression or injection molding are produced.

The terms "vinyl polymers" and "vinyl chloride polymers" used here and below refer to vinyl chloride homopolymers and random «: copolymers with one or more other monoethylenically unsaturated compounds. Special comonomers which can be used are suitable are olefins with 2 to 4 carbon atoms, i.e. ethylene. Propylene or butene-1. monoolefinically unsaturated Carboxylic acids with 3 to 4 carbon atoms, such as acrylic or methacrylic acid, lower alkyl esters Acrylic and methacrylic acid and their hydroxy and amino-substituted derivatives, vinyl esters of unbranched or branched monocarboxylic acids with 2 up to 12 carbon atoms, maleic anhydride and the diesters of maleic and fumaric acid with aliphatic alcohols that contain up to 18 carbon atoms. Likewise can according to the process of the invention, random copolymers of vinyl chloride with styrene or its suitable ones Derivatives, e.g. μ-chlorostyrene or p-tert-butylstyrene, can be obtained. The HemeUbarkeit this particular copolymer is completely unexpected, given that it has not been it was easy to produce these polymers by aqueous suspension polymerization, which was enormous Difference between the reactivity of the two monomers in the polymerization system is attributable.

In general, the random copolymers according to the invention contain 50 to 99.5 percent by weight, preferably about 65 to 99 percent by weight of polymerized vinyl chloride and 0.5 to 50 percent by weight, preferably 1 to 35 percent by weight of the polymerized comonomer. The currently preferred polymers are those which contain vinyl chloride which is copolymerized with olefins, in particular with propylene, since these products can best be adapted to a wide range of applications.

The terms "vinyl polymers" and "vinyl chloride polymer" are intended to refer to copolymers which contain polymerized vinyl chloride that is grafted onto another polymer, which can be a homopolymer or a copolymer. Currently preferred polymers for grafting according to the method of the invention are e.g. B. polyolefins such as polyethylene or polypropylene, their chlorinated derivatives and copolymers of the olefins mentioned. Homopolymers of vinyl esters of monocarboxylic acids having 1 to 8 carbon atoms, e.g. As vinyl acetate, vinyl propionate or vinyl butyrate, and copolymers thereof with C ₂ _ ₄ olefins, said copolymers containing a varying weight percent of polymerized Vinylester. Homopolymers of acrylic and methacrylic acids and their lower alkyl esters, homopolymers of acrylamide, methacrylamide and acrylonitrile and the copolymers of these monomers.

The grafted copolymers according to the invention generally contain 60 to 95 percent by weight of polymerized vinyl chloride, the total weight of the polymer being 5 to 40 percent by weight Polymerisal substrate are included. The currently preferred graft polymers contain 75 to 85 percent by weight of polymerized vinyl chloride and 15 to 25 percent by weight of ethylene-vinyl acetate copolymer. The copolymer in turn contains 10 up to 40 percent by weight, preferably 18 to 30 percent by weight, polymerized vinyl acetate.

Both the products according to the invention and representative examples of known vinyl chloride polymers with different average molecular weights were examined for methyl end groups (--CHI ₃ ) with the aid of infrared spectroscopy (Ik). These samples were examined before and after they were reduced by the known standard method of hydrogenation with lithium aluminum hydride (LiAlH _4). Details of the testing methods used will be given later in a specific example.

The investigations into the tacticity in the molecule by means of IR showed that conventional polyvinyl chloride (produced at below 90 ^° C.) has a somewhat more syndiotactic structure than the polymers of this invention. The test results also show that in the branches of conventional polyvinyl chloride the CH _{3 end} groups adjacent to the monomer units predominantly have a head-to-head

Have configuration. This can be seen from the fact that, for both polymers before and after the reduction, almost the same values are found for the number of CHi uppers per 1000 CH ₂ groups. As already established, conventional Vinykshiöridpölymeiisate those at polymerization ■ tionstempefäturen ^ ÖTI be won 0 to 90 ° C, preferably from 20 to 80 ⁰ C. The average Qehafr at CHj end group * H in these non-reduced polymers is about 9 to 10 CH, groups AUfIOOOCH ₂ -OrUPpCn. The analysis of the polymers from the reduction gives values of about 10 to 13 CH.-O groups per 1000 CH.sub.1 groups. Since chlorine is replaced by hydrogen during the reduction, it must be concluded that the difference found in CHj groups of the unreduced polymer compared to those of the reduced, ie 1 to 3 CHj groups per 1000 CHj groups. can be attributed to the chlorine methyl groups at the ends of the branching chains of the unreduced polymer. During the reduction of the polymer, the CH ₂ -Cl end groups are converted into CHj groups. On the basis of the analysis it is concluded that conventional vinyl chloride polymers contain an average of about 10 CHj groups and a maximum of 3 CHjCl groups for every 1000 CH ₂ groups.

It has been found that the vinyl chloride polymers according to the invention have almost no tacticity, ie these polymers have almost the same percentage of syndiotactic and isotactic components. In these polymers the branching increases with the same order of magnitude with which the polymerisation temperature to be used is increased from 90 to 165 "C. According to analysis, these polymers contain 10 to 13 CH 1 end groups on the branches for _{every 1000 CH 2 groups: the highest CH 3} -Gruppenwert has been demonstrated in a polymer which was produced at the highest polymerization temperature the same analysis of the reduced polymer yields values 13 to 27 CH, end groups per 1000 CH ₂ groups. the increase of the content of CH ₃ groups in the polymers of the invention is accordingly after reduction between 3 to 14 CH ₃ groups per 1,000 CH ₂ groups. when comparing the number of the conventional vinyl chloride polymers to place the end groups being the said increase in the larger number of CH ₂ Cl end groups of the Side chain «, in contrast to the conventional polymerizates contain the invented polymerizates on average 3 to 14 CHjCt groups for every 100 CH ₂ groups

It is noted that melting point measurements on the reduced polymers did not show any degradation, i.e. none occurred in the course of the reduction Caused splitting of the chain.

Further analyzes showed that a polymer dter Although the invention has a higher average molecular weight than some other conventional vinyl chloride potytnerizates, it nonetheless has a lower limit viscosity value than conventional vinyl chloride polymerizates, which can be ascribed to a higher degree of branching.

To a Viiiytehlorid-HoTnopolyrnerisat or a random copolymer according to the method 'the Invention to prepare, is in a suitable container, which is dissolved in an aqueous medium Contains suspension aid. Vinyl chloride or a Mixture of the same with one or more, with this copolymerizable monomers introduced. Thereafter, the monomers contained in aqueous suspension is heated ⁰ C with stirring at 90 to His, S whereupon as much water in the Reaktionigefaß pumped: is to excite a pressure which at least ktionsbedingungcn at the applied Rejl the same, but preferably above the vapor * print of the bin of the given Polyrnerisatltönstehipera for the monomer or monomers used Cherishes. While stirring the monomer ·: fisuspetision continues, the free radical becomes; generating catalyst is added all at once to the reaction vessel or, alternatively, the required

Amount of catalyst running during the reaction added. The particular way in which the catalyst is added depends on the particular catalyst as well also by others, described in more detail Factors dependent. During the reac ion,

to additionally required water in the reaction vessel pumped in order to maintain a pressure therein which is at least equal to or above the vapor pressure of the monomer or of the monomer mixture which has not yet reacted in the reaction mixture. lie

$ 2 must.

In order to prepare PfiDpfpolymerisationsprodukte g: according to the invention, the process is carried out essentially as described; jedocli will be in front of the Addition of the vinyl chloride monomer; u grafting Tanning polymer in the reaction vessel and in dispersed in the aqueous medium. In addition, before the addition of the catalyst, after running Addition of the monomer, heating the reaction mixture to the desired polymerisation temperature and, after reaching a sufficient reaction pressure, the reaction mixture. preferably for a period of r. B. 15 to 30 Minutes, stirred. In this way, the suspended polymer swells and eventually becomes part dissolved by the monomer, whereby de grafting effect is increased.

The method according to the invention can be carried out in any suitable reaction vessel which is provided with a stirrer and which is made of corrosion-resistant material. material. z. B. made of stainless steel. 1 can be taken. The reaction container must ο be designed so that it can hold pressures that are at least equal to who. t is not greater than the vapor pressure of the monomer or the monomer mixture at the polymer temperature

fatures are, endure. Stainless steel reactors, which can withstand 35 to 30 kg / cm ² , are particularly suitable and clever as potentiating tanks.

As has already been pointed out above, the process is generally carried out at a pressure which is at least the vapor pressure of the Vmytehloridimnomere or the monomer mixture is the same at the specific polymerization temperature. Of the The required pressure in the container is created by pumping in a sufficient amount of water.

posed. In the presently practiced preferred practice of the invention, the reaction vessel is after the potentiating temperature is reached and before a catalyst is added, essentially filled with liquid. According to this, lies

then the pressure in the container is substantially above that Vapor pressure of the monomer. This embodiment is used with preference, since in the case of SbIkIi en arrangements heat-degraded Porynts are at the

Walls of the reaction vessel above the surface the liquid on <jruntl the applied, extreme high polymerization temperatures arise very easily. However, if one proceeds in such a way that none develop to high local catalyst furnace concentrations, z '. fc. by inserting the catalyst below the surface of the reaction mixture the reaction vessel needs to avoid the formation of products that are not thermally degraded not to be almost entirely filled with liquid, in a similar way as previously set out the The total amount of catalyst required is introduced into the reaction mixture at the start of the reaction will. However, the required amount of catalyst can also increase as the reaction proceeds and after being admitted. At present, the continuous addition of the catalyst is preferred because this technique to control both the rate of the reaction and that of the indirect reaction temperature serves. The process of continuous or portion-wise addition of the catalyst enables the use of many catalysts which are extremely unstable at the polymerization temperature used are. If all of these are added to the reaction mixture at the beginning, would these catalysts decompose very quickly and are ineffective for the polymerisation reaction that takes place be. They could also represent a hazard in that they could tend to explode. Of course you can the polymerization catalyst can be added to the reaction mixture at the beginning, provided that the catalyst is not too unstable at the polymerization temperature. It is said to have a half-life have that is sufficient. around free radicals for a sufficiently long period of time Maintaining the polymerization reaction to produce its essential completion.

Any of the currently available monomer soluble free radical generating catalysts that have hitherto normally been beneficial for polymerization were used, e.g. B. for vinyl chloride in aqueous Suspension, provided that they have a suitable rate of decomposition at the polymerization temperatures and reasonably stable on storage and are in use can be used as suitable catalysts. In selecting of the catalysts is their half-life at the polymerization temperature of primary importance. This should be such that the catalyst is in the whole Reaction mixture can be distributed before decomposition. On the other hand, the half-life should be short be enough that the catalyst is substantially completely decomposed during the polymerization and none of this remains in the final polymer. Depending on the individual polymerization temperatures used Specifically suitable catalysts are 2,4-dichlorobenzoyl. Caprylyl. and the lauroyl peroxide, the tert-butyl peroxyisobutyrate, tert-butyl peroxypivalate, benzoyl peroxide, p-benzoyl peroxide, Hydroxyheptyr peroxide. Cyclohexanone peroxtd, Di-tert-butyl diperphthalate, tert-butyl peracetate. tert-butyl perbenzoate. Dicumyl peroxide. tert-butyl hydroperoxide, Methyl ethyl ketoperoxide, di-tert-butyl peroxide, acetylcyclohexanesulfonyl peroxide, di- (sec-butyl) peroxydicarbonate and isobutyryl peroxtd. Of these compounds are preferred for the Implementation of the invention, according to which the catalyst is introduced in portions, those especially suitable which have a half-life within the polymerization temperature range from 0.1 second to 12 minutes, preferably from 0.5 to 5 minutes, exhibit. Such currently preferred kataiysa * gates are e.g. Benzoyipcroxid, tert.-ίlUtylperoxypivalat, Lauroyl peroxide, 2,4-dichlorobfin ^ oyl peroxide, Caprylyl peroxide, tert-butyl peracetate luride p-chlorobenzoyl peroxide. In general, the concentration of the catalyst currently used is from 0.01 to

■ ο 2.0 ° _o . based on the total batch of monomers. The preferred concentration is 0.05 to 0.5 percent by weight, calculated on the monomer.

Apart from the extremely high polymerization temperature, the process is generally similar to

is the well-known suspension polymerization! directed. For any proportion of vinyl chloride monomer or mixture of monomers 0.4 to 6 parts of Wnisser are required. The ratio of water to monomer is 0.5 to 2: 1.

ίο To ensure a stable suspension of the monomer in the aqueous medium can be any of the currently available dispersing aids or the Protective colloids, which are usually used in the system for vinyl chloride suspension polymerization serve, are used. The prerequisite for this is that these agents are both stable and completely soluble in the The polymerization temperature. Suitable suspension aids are currently e.g. polyvinyl alcohol, Carboxymethyl cellulose, polyvinylpyrrolidone and copolymers thereof, as well as the nonionics Alkylene oxide-alkylene glycol adducts. The concentration of the suspending aid is generally in the range between 0.05 and 4 percent by weight, based on the monomer or on the monomer mixture.

The concentration of the suspension aid is preferably between 0.1 and 2 percent by weight, based on the monomer or on the monomer mixture. 0.2 to 1.0 percent by weight is more preferred.

The method according to the invention is, as already said, carried out in a temperature range of 90 to 165 "C. As is to be expected. the at the upper limit of this temperature range produced Polymers have a lower average molecular weight and are more branched than those Polymers made at lower temperatures will. Measurements due to reduced viscosity are used throughout to provide comparative molecular weights of products to get hn average. The low viscosity numbers and the average molecular weights of the products can be compared with those made conventionally Polymers draw conclusions about the degree of branching. Procedure for determining these values will be described later.

The process according to the invention generally proceeds within 1 to 12 hours in front of him and depends on the specific temperature used, the specific catalyst and its Concentration. The entire reaction time. i.e. the rate of polymerization also depends on the extent to which the heat of reaction is applied is discharged from the polymerization mixture. In current practice, effective development

6s removal of the heat of reaction through the use double-walled reaction vessel or, more advantageously, through a cooling coil, soft in the reaction material is located. With the currently preferred

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Execution of the process are carried out using such a cooling coil and with portiöilSwelser addition of the catalyst during the 90 to 95% of the monomer over the course of the reaction wtfifefld a duration of 1 to 3 hours reversed, ÖömgerhäÖ the process according to the invention represents an extremely economical method for the production of vinyl chloride polynie products.

The average particle size of the VinyldWoridpolymerisate of the invention can be between SO and 400 μ. These products are valuable depending on their structure, e.g. B. as a flame retardant, as a processing aid for other polymers, so as Plastic component in polyvinyl foam and flooring material, in the manufacture of various pressed article and of various coating compositions by calendering or roller coating.

For the preparation of liquid coating compositions for the production of coatings on various substrates, however, polymers are important smaller particle size is required. Accordingly, the method according to the invention when the vinyl chloride polymers as a dispersion, latex or with Use of coating material in dissolved form should be used to reduce the fine particle size of the polymer carried out with modifications. This is done, for example, by a small amount an emulsifying or wetting agent is added one after the other or at the same time as the suspending agent to the polymerization batch in order to achieve the desired reduction in the average particle size of the polymer.

The reduced viscosity values for the polymers according to the invention are used to measure the Molecular weights. These values are obtained by preparing a solution of 1 g of polymer in 100 ml Cyclohexanone and measurement at 30 ° C determined: the flow time of this solution is compared with that of the cyclohexane using a calibrated pipette. the reduced viscosity is then calculated as follows:

T ₁₁ - · ■ solvent discharge in seconds,

7, - The dissolved polymer flows out in seconds.

Specific viscosity -

1.

Red viscosity =

Specific viscosity Γ

C is the concentration of the polymer in g / polymer per 100 ml of solvent.

According to the specific polymerization temperature used and the one used in each case As a catalyst, the vinyl chloride polymers have a reduced viscosity ranging from 0.12 to 0.58. It must be noted that in the folds where a homopolymerizate with an extremely low molecular weight is desired, a chain stopper is added to the reaction mixture can. In this way, polymers with a reduced viscosity value as low as 0.08 can be obtained. Suitable chain transfer agents are the lower aliphatic alcohols, such as isopropanol. and halogenated «, e.g. chlorinated or bronzed. Hydrocarbons with 1 to 6 carbon atoms.

The examples illustrate the invention. Parts are by weight.

example 1 Production of the vinyl chloride polymer A 3.8 1 reaction vessel made of rustproof

Free steel, which can withstand a pressure of 350 kg / cm ² , is connected to a mechanical stirrer, a cooling coil, a thermocouple, a pressure gauge, with cashing for charging, a safety valve which is connected to a vent line

• 5 is equipped. Be in this reaction vessel 1.5 l of fully demineralized, degassed water containing 7.2 g of dissolved polyvinyl alcohol are added. The reaction vessel is then sealed and oxygenated by pumping out several times to a pressure

ίο freed from 10 Torr, whereupon the vacuum is replaced by the introduction of vinyl chloride. The reaction vessel is then charged with 908 g of distilled vinyl chloride with stirring, whereupon the reaction mixture is heated ^{to 90 ° C.} After that, will

»5 a sufficient amount of deionized, degassed water was pumped into the reaction vessel in order to achieve a pressure of about 35 kg / cm ^2. At this pressure the reaction vessel is almost completely filled with liquid.

While stirring is continued add 5 ml a solution of tert-butyl peroxypivalate in trichlorotrifluoroethane (40 g of catalyst with 75% activity in 200 ml of solvent) is pumped into the reaction vessel. The polymerization is allowed to proceed without further action Run addition of catalyst until at least 30 "" (about 15 minutes reaction time) conversion is reached are. Thereafter, 2 ml of catalyst are added every 5 minutes until the polymerization is complete solution added, whereby in a suitable manner the

Necessary water is additionally pumped in to achieve that the reaction vessel is substantially filled with liquid. The total concentration of the catalyst is 0.37 percent by weight, based on the monomer. After the addition ά

Catalyst is stopped. will be the reaction

mixture stirred for 15 minutes at LOCTC

total response time amounts to about 75 Mi grooves.

The contents of the reaction vessel are then gßkähh |

taken out and the polymer withdrawn. It is repeated with fully demineralized Wa: washed and finally under reduced pressure down to a moisture content of a few dried as 0.1 percent by weight. This polymeri

sat. which is 95 ° "of the theoretical yield g < is obtained has a reduced viscosity of 0.40.

Use of the polymer as a flame-retardant additive

In order to test the effectiveness as a flame-retardant Zi, a portion of the polymer is ge .. Example 1 with commercially available, bottom rope * hehen low-pressure polyethylene and mixed with it polypropylene. With every attempt ~ « 30 parts by weight, based on the total mixture m the polyolefin nattels a heated 2-Wafc siuhtes mixed in. After a humble wade

The mixture is peeled off the stool as fur. Rolled heads of the polyolefin are made as a control material. Samples are made from the skins cut off and tested for flammability according to ASTM test standard D-635-63. The following results were obtained:

Table I.

Polymer Rolling temperature
("C) Hntnammungsbc rich Burning speed Polyethylene D = 0.921,
Melt index 3.0
Polyethylene 0 = 0.921,
Schmeb index 3.0+ PVC
Polyethylene D ₂ = 0.962,
Melt index 6.0
Polyethylene D ₂ = 0.962,
Schinelz Index 6.0+ PVC
Polypiopyien D = 0.905,
Schinelz index 5.0
Polypropylene D = 0.905,
Melt index 5.0+ PVC 138
138
168
168
177
177 burns
self-extinguishing
burns
self-extinguishing
burns
self-extinguishing 18.5 cm / minute
15.2 cm / minute
19.5 cm / minute

Those samples which contain the vinyl chloride polymer and are not dripping will burn or glow for 1.5 minutes before they scale.

The determination of the physical properties of pressed samples of each of the polymers and polymer mixtures listed above show that the addition of the vinyl chloride polymer according to Example 1 achieves a significant increase in the strength of the polyolefins, what when comparing the higher tensile strength moduli for the samples from the polymer mixture compared to those of the straight-chain polyolefins.

This comparative experiment A shows that a thermally evaporated vinyl chloride polymer is formed if the reaction vessel is not substantially filled with liquid while the process according to the invention is being carried out. 1715 ml of full, salted, degassed water, which contains 4.8 g of dissolved polyvinyl alcohol, are placed in a reaction vessel of the type according to Example 1. The apparatus is closed and degassed as in Example 1, then 613 g of the purified vinyl chloride monomer are added under pressure. While stirring is continued, the pressure in the system is about 28 kg, cm ² . The reaction mixture is then warmed to 100, 4 ml of the 20% tert-butyric oxyprate solution with trichlorotrifluoroethane as solvent (cf. Example 1) are pumped into the reaction vessel, and the resulting mixture is continued for about 15 minutes touched. Thereafter, a total of 44 ml of the catalyst solution are added in portions of 2 ml each after every 5th minute. The pressure in the reaction vessel has now dropped to 7 kg / cm ² . The total reaction time is a little more than 2 hours. The reaction vessel is then cooled and the polymer is deposited, washed and dried as described in Example 1. The yield is about 85% of theory. The polymer has a reduced viscosity of 0.39. In contrast to the product of Example 1, however, this polymer is partially decomposed, as can be seen from the o \ mklen particles, which are contained in a considerable percentage.

Examples 2 and 3

In these examples, vinyl chloride homopolymers at 130 and i 60 ° C according to the example 1 described method using the same apparatus. With every attempt the The total amount of catalyst required is continuously pumped in during the reaction and fully demineralized water are also pumped in as required to maintain the working pressure The polymerization regulation and the reaction conditions indications are as follows:

Polymerization temp. ⁰ C ... Example 2 Example 3 40 Working pressure, kg / cm ² Total reaction time. 130 160 Minutes 42 84 45 Fully demineralized water, ml ... Aqueous suspending aid 45 90 medium solution, g (2% 1000 1000 Polyvinyl alcohol i. Water) Vinyl chloride E so total concentration of 360 Catalyst,% 908 913 Yield. ° "of theory ... Reduced viscosity of the 1.0 1.9 Polymers * I 95 72.5 0.25 0.14

Example 4

Polymerization products of Examples 1.2 and (or selected samples of conventionally produced polyvinyl chloride are analyzed for the content of a CHj groups at the ends of the branches using a specially developed: IR method Compensation for the interference of the CH ₂ -afeso (ptionsbaisten for the amorphous TeO, which usually in the range of 138OcBT ¹ bfe BStTan ¹ m the spectra d «

Polyvinyl chloride occur a linear

higher density used. By this, this area is that the polyethylene is of the analog, switched off and a sharp, symmetrical band of CHj-Grappas can be observed in the vicinity of the range of 1 380 cm ^"l The procedure is as follows.:

Made of high density polyethylene, according to the M.C. Harvey and UL. Peters, Anal. Chemistry, VoJ 32, No. 12, 1960, p. 1725, reported the method used to produce a wedge. The wedge is pointed and has a different thickness from 0.076 to 0.46 mm. ■ It is cut up to obtain a sample of 31.7 χ 82.5 which is then placed on the metal frame of the Barnes variable path cell (the salt block removed). The frame is attached to the cell holder on a Teflon slider. the The sample is rotatably mounted to change the thickness.

In order to be able to analyze each polymer, a film is produced by pouring a solution of the polymer in tetrahydrofuran (0.25 g of polymer in 5 ml of solvent) onto a KBr plate. The solvent is in a furnace in which a reduced pressure prevails, for 30 minutes at 8O ⁰ C verdünstet. The dried film is examined for residual solvent by checking the 5.5 μ to 6.0 μ and 9.2 to 9.5 μ ranges in the IR. The completely dried film is then mounted on the holder.

The spectra of the polyethylene and polyvinyl chloride are recorded on a Perkin-Elmer model 521 infrared grating spectrophotometer. The slit diaphragm is at 332 μ; the gain factor is 4. The recorder is manually set to 90% permeability at 1600 cm '. The sample film is brought into the beam path for samples and the polyethylene wedge into the reference beam path. The wedge is rotated until the writer is at 90% permeability. The program speed is 50 cm / min., The zero-order interference being suppressed. If the two wings of the 13150 cm "'band are uneven, they are compensated by rotating the recording drum back to 1369 cm' and adjusting the polyethylene wedge until the two wings of the 1380 cm 'band are even. Then the Drum on 1600 waves / cm
turned back and - if necessary - adjusted the adjustment knob of the spectrophotometer so that the recorder is at 90% transmittance. Now the area from 1600 to 1100 cm 'is covered. A sharp, symmetrical band at 1380 cm 'is observed in the polyvinyl chloride spectrum. The intensity of this band is corrected until the absorption ratio is proportional to the effective thickness of the film (K value).

The absorption of the corrected band at about 1338 cm " ^l is roughly proportional to the thickness of the film sample.

portional. The ratio of the absorptions A 1380 cm " ¹ to A 1338 cm" ¹ represents the K value. The branching of the non-reduced polyvinyl chloride products is determined from the calculated K values (A 1380 / A1338) and converted into the ratio CH ₃ /! 000 CIl ₂

ίο converted, wherein the ratio of 1.5 CH _3/1000 CH ₂ (Marlex 6350) serves as a basis as Verzwiugungsindex a commercially available PVC. The results of these determinations show that commercially available PVC materials or PVC materials produced in a conventional manner have a K value in the range of 0.12) and a content of about 10 CH ₃ groups per 1000 CH _r groups, as is shown in FIG summarizing Table II below> J can be seen. The polyvinyl chloride according to the invention have 10 to 13

ίο CH ₃ groups to 1000 CH ₂ inip.

The polymers of Examples 1, 2 and 3 as well as selected conventionally produced polyvinyl chloride products with approximately the same average molecular weight are in a nitrogen atmosphere in

known manner, in which LiZJH _{4 is used} as a catalyst, subjected to the reducing hydrogenation. This method is described in detail by A. N akajima et al in "Makromolekulare Chemie", 95, 1966, p. 40. The first reduction phase

is carried out at 65 ° C for 360 hours, with Tetrahydrofuraa as the solvent. The second reduction stage is carried out at 100 ⁰ C using a tetrahydrofuran Dekalinmischung during 155 hours. After each reduction phase, the reduced polymer is obtained by pouring the reaction mixture into excess water, adding so much H ₂ SO ₄ until a pH of 2 is reached and then filtering the mixture. The polymer is washed repeatedly and then dried.

The branching values for the reduced polyvinyl chloride samples were obtained using the calibration curve A 1378 cm "Al 368 cm" ¹ = / (CH _{3 ZCH 2} ). Which was established for the linear C ₁₆ C ₈₀ hydrocarbons. Details of how these were obtained Calibration curves are given by B ο ccat ο A. et al. In “Makromolekulare Chemie”, 108, 1967, pp. 218 to 233. On the basis of the A 1378 cm ', A 1368 cm' values recorded and the calibration relationship:

A 1378, A 1368 = 20 iCH ₃ / CH ₂ ) +0.2939 66.14 (CH ₃ CH ₂ ) the ratio of CF ₃ to 1000 CH ₂ in the analyzed polyvinyl chloride samples was determined. The results for this are given in Table II.

Table Il

sample Polymer! sation temperature
CC) CH _{1/1000 of} CH ₁
not reduced
Polymer reduced polymer Conventional polyvinyl chloride
(red. visc, 1.55)
Conventional polyvinyl chloride
fred. Visc. ^ 63)
Polyvinylchkiride with 8 percent by weight
Chain carrier (reduced viscosity 0.17) 55
55
71-74 9
9
10 10.0)
10.0 *)
13th

continuation

sample Polymerization temperature
IC) CH ₁ / 1000th CH,
not reduced
Polymer reduced polymcisai Product according to example I,
Product according to example 2
Product according to example 3 90
130
160 10
11th
13th 13th
23
27

*) CHj / 1000 CH ₂ values in the literature.

D ^; These results show that the vinyl chloride polymers according to the invention _{contain a higher percentage of CH 2} Cl terminus than conventional polyvinyl chloride, which is evident _{from the larger number of CH 1} to 1000 CH _{2 found.}

The intrinsic viscosity of the polymer samples was measured szahl in tetrahydrofuran at 25 C using a modified ^G Ositwald capillary viscometer.

The melting points of the reduced vinyl chloride polymers and the ces polyethylene are alike and were determined by the Perkin-Elmer differential calorimetry method found at three different heating rates. These experiments show that the reduced products have a polyethylene structure and that they are keirt-free during the reduction Breakdown of the chain took place.

In the following, number average and weight average molecular weights are given which by means of gel permeation chromatography for some of the polymers listed in Table II and which also ^{relate to the homopolymers produced at 100 and 120 °} C. according to the invention. The limiting viscosity number of the polymers is:

Table III

sample

Polymerisation temperature

Γ Ct

Limiting viscosity number
(dl / g)

Conventional polyvinyl chloride
(reduced viscosity == 0.63)

Polyvinyl chloride - 8% chain carrier.

Polyvinyl chloride - li)% chain carrier

Polymer according to Example 1 ...

Polymer g: according to the invention ...

Polymer according to the invention ...

Polymer according to Example 2 ...

Polymer according to Example 3 ...

55
71-74

55

90
100
120
130
160

The values given show that the homopolymers according to the invention, the higher polymerization temperature have a higher average molecular weight than any of the conventional polymers, such as those made with chain transfer agents. However, the highly branched structure of these products is reflected in a significantly lower intrinsic viscosity.

It can be safely based on the homopolymers alu Molecular structure data found are assumed that the vinyl chloride polymer chains of random and graft copolymers, which were manufactured according to detailed processes, have a different structure than other similar polymeric cuticles obtained by conventional means will. Support for this assumption are the various improved processing properties of these products.

38000
36800

13600
5000

10200 4100 36800 18700 25100 12500 17500 9000 13000 7800 10561 6164 Example 5

0.52

0.188

0.162

0.438

0.39

0.25

0.145

0.09

Production of a copolymer

A copolymer of vinyl chloride and propylene is produced in a 38 l stainless steel reaction vessel of the type described in Example 1. 11.3 l of fully deionized water and a solution of 72.6 g of polyvinyl alcohol in 3.6 l of water are added to the reaction vessel, whereupon the reactor is closed and, as in Example 1, freed from oxygen. The reaction vessel is further charged with 8808 g of distilled vinyl chloride and with 272 g of propylene while stirring. The reaction mixture is ^{heated to 100 °} C., whereupon a sufficient amount of deionized water is pumped into the reaction vessel until the pressure is 35 kg / cm ² . At this pressure the monomers are liquid. The reaction vessel is then in

409 584/394

IO

essentially filled with liquid. While stirring is continued, a solution of 20 ml of Prt.-ButyJperoxypivalat solution according to Example 1 is pumped into the reaction vessel, then the reaction mixture is stirred for a further 15 minutes. Until the end of the polymerization, 10 ml of the catalyst solution W are poured in every 10 minutes, and water is poured in in a similar manner as required to maintain the working pressure. The total reaction time is 2 l ₁ hours. The total concentration used for the catalyst used is 0.23 °, based on the weight of the monomer charge.

The copolymer is recovered, purified and Dried as in Example 1. The yield is 90% of theory. The polymer has a reduced Viscosity of 0.44 and contains approximately 3.0 weight percent polymerized propylene.

The use of the copolymer as a binder m polyvinyl asbestos flooring

A floor covering material which contains the copolymer and asbestos is produced according to the following approach: _{Tej) e}

Copolymer 100

Butyl benzyl phthalate plasticizer ... 25

Epoxy type plasticizer 5

Containing solid nitrogen

organic stabilizer 3

Calcium carbonate 360

Asbes-t 120

Titanium dioxide 48

Stearic acid 0.5

The ingredients listed above are mixed together, the mixture in a Banbury mixer given and then treated at a temperature of 148 to 163 ° C for 3 minutes. That Heat treated material is then placed in a 2-roll mill and processed at 12PC. After this the material treated for 5 minutes at this temperature is mixed, it is considered as thin, 3.175 mm thick skin peeled off. Another approach for similar purposes is processed in the same way. This other approach is the same except that instead of the vinyl chloride-propylene copolymer according to the above example a conventional vinyl chloride copolymer (containing 15 percent by weight Vinyl acetate), as it is usually used for flooring will. The vinyl acetate copolymer has a reduced viscosity of 0.61.

Samples of the rolled pelts are taken from each batch in accordance with the regulations of the Revised Federal Specifications for Vinyl-Asbestos Floor Tile ", L-T-00345 (COM-NBS). Checked August 28, 1959. on Based on these regulations, the following results were obtained:

Table IV properties

Notch test (McBurney)
Room temperature 46 ° C,
1 min. - 25.4 mm

plate

Vinyl chloride

Propylene copolymer

0.007

Vinyl chloride Vinyl acetate Copolymer properties

10 min-26.4 mm ....

30 sec. - 25.4 mm

Abrasion (taber)

g / 1000 cycles

Deflection test
Deflection, kg / cm ".
Break angle, degrees -

tiller

Vinyl chloride

Propylene copolymers

0.0085
0.014

0.23

213
10

Vinyl chloride. Vinyl acetate

0.00875 0.021

0.40

194
7th

These values show that the copolymer according to Example 5 gives a floor covering of which a specimen is harder and more resistant to Abrasion is, as a folche, which comes from the well-known tradeIspoiyvinyl asbestos footbcL ;; bdag. There" Flooring material mixed with the copolymerisai manufactured according to the example is more flexible, wa < becomes clearly visible by applying a greater force when bending the specimen until it breaks

In order to test the water resistance of the panels according to the above approaches, samples were taken from each Plate weighed and immersed in water for 1, 2 and 3 weeks at room temperature At the end of each storage period, the samples were removed, wiping off most of the water released and weighed. The percentage de: water absorbed during storage was determined on the basis of the weight differences, with reference to the original weight of the sample was taken. Using this method the following results are obtained:

Table V Flatware

Vinyl chloride-propylene copolymer

Vinyl chloride-vinyl acetate copolymer ..

Water absorption. ',
storage

1 week

0.35
0.90

2 weeks 3 weeks

0.60
1.17

0.78 1.43

0.007

One approach to producing a plate containing the copolymer according to Example 5 is more resistant against moisture, as such that with a vinyl chloride-vinyl acetate copolymer de « Prior art is produced. Accordingly a panel made in accordance with the present example should remain scaled during use

It is difficult to make vinyl chloride-propylene copolymers by conventional methods since long polymerization times, e.g. 18 hours or less more are needed because of the low catalytic converter efficiency. It is characteristic that nut up to 70% can be implemented. The conventional copolymers cannot be used as binders in batches be used in asbestos-containing flooring material because of the in their manufacture temperatures used are poorly suited for further processing,

Use as rigid foam

Was constructed using the following approach _e jn HartschaumstofTmit the polymer prepared according to Example!:

Polymer 2500 parts

Liquid Organotin Mercaptide

Stabilizer '75 x _e j | _e

Stabilizer-Metal and Thermit Corp.

The constituents are mixed with one another and milled at 235 ° C. for 5 minutes. The soft one Material is peeled off as a thin layer and formed into pellets. The material made up of cubes is immersed in trichlorethylene for one hour, about 35 percent by weight of the solvent were recorded.

The cubes treated in this way are processed in a 25.4 mm injection molding machine which contains a simple worm screw. The machine has a 3.175 mm slot nozzle. The screw speed is 20 rpm, and the temperature of the injection molding machine between the funnel and the nozzle is 9? to 177 ⁰ C. The die temperature is 146 ° C. The Schaumstoffhat a density of 0.320 g / cc.

Use as a processing aid
for high molecular weight polyvinyl chloride

The following describes the use of the polymer according to Example 1 as a processing aid for a high molecular weight polyvinyl chloride (reduced viscosity 1.55).

An approach is put together according to which 80 parts of the high molecular weight polyvinyl chloride are used 20 parts of the polymer according to Example 1 come. Each 10 (i Tsile of the mixture are made with 3 parts a liquid organotin mercaptide stabilizer added.

The components are mixed with one another and treated for 5 minutes at 177 ° C. on a 2-roll mill. Part of the softened material is pressed at 177 ° C., the pressure increasing continuously to 3500 kg / cm ² and the pressing time is a total of 8 minutes. For comparison purposes, a batch which contains only the high molecular weight polyvinyl chloride and the stabilizer (3 parts to 100 parts of polyvinyl chloride) is rolled and pressed in the same way.

Samples from each crimped batch are tested for strength according to ASTM D-638 64T. The results are as follows:

Table VI

Check

Tensile strength, kg / cm ²
Tensile modulus, kg / cm ² ..
Elongation at break,% ...

Molecular weight

Polyvinyl chloride mixture

536

255 · 10 ³
85

534

262 10 ³
93

The rheology of the melt of each of the above mixtures is used with the Sieglaff-McKelvey rheometer in which a 25.4 mm long and 1.01 mm in diameter measured capillary, determined at 216 ⁰ C. The results are as follows:

Table VII

Viscosity (Poise) mixture Shear speed High molecular 35-10 * (see " ¹ ) Polyvinyl chloride 11.4-10 * 10 ° 58-10 * 3.0 · 10 * 10 ^l 17-10 * 0.57 10 * ΙΟ ² 4.3 · 10 * 10 ³ 0.98 ■ 10 * Shear rate 490 in case of melt fracture, lake"" 110

These results show dall d ^; e mixture which contains 20 percent by weight of vinyl chloride homopolymer according to the invention, compared to that whose plastic only has a high molecular weight, has significantly improved flow properties. Accordingly, they also have excellent processing properties.

The use of the product according to the invention as a processing aid for other high molecular weight Plastics do not reduce the physical properties of the in any discernible way the former. This can be seen from the equivalent values for the properties in Table VI.

Example 6

According to this example, a vinyl chloride-vinyl acetate copolymer is produced at 100.degree. C. using the method and apparatus according to Example 1. After 1850 ml of deionized water, which contains 7 g of polyvinyl alcohol and 180 g of vinyl acetate monomer, have been added to the reaction vessel, the reaction vessel is closed and evacuated. While stirring, the vinyl chloride (1020 g) is then added, whereupon the reaction mixture heated to 100 ⁰ C and sufficient water is geptimpt into the reaction vessel, until a pressure of 35 kg / cm ² (working pressure) is reached. Thereafter, dissolved tert-butyl peroxypivalate catalyst (as in Example 1) is added in proportions of 2 ml over the duration of the reaction. The GesamtkonzenUation of catalyst is 0.68 "", based on the total weight of the introduced monomers. The reaction takes 45 minutes The polymer obtained in 83 ° _n yield contains 13.6 weight percent polymerized vinyl acetate and has a reduced viscosity of 0.37.

This product has excellent viscosity behavior in solution, as shown by the following results, obtained for differently concentrated solutions of this copolymer in methyl ethyl ketone were, recognize louse. The concentrations are based on the weight of the copolymers. To the Comparison are made for matching solutions of a vinyl chloride copolymer yeasted in the usual way, that contains 13 to 15 percent by weight of vinyl acetate, also indicated.

Table VItI

Concentration of the solution
(Weight) 15% V skosiiät.
20% cF *)
25% Copolymer according to 20th 4! 71 Conventional
Copolymer 39 78 194

based on the weight of the vinyl chloride contained. Similar extractions with hot toluene gave a soluble fraction. After evaporation of the solvent, it was found that this fraction contains a percentage of chlorine which is equivalent to the percentage by weight of the vinyl chloride contained in the graft polymer. Based on these results can turn assumed that the graft copolymer no free i ^H opoljfmersubstrat

to contain more. However, straight vinyl chloride homopolymer can be used. contain.

*) Determined with the Brookfield viscometer (model RV). using spindle # 3 at 100 rpm.

• 5

The low viscosity of the lorning of the vinyl chloride-vinyl acetate copolymer According to Example 6, it is used for coatings on paper, in color batches and in other areas where flowable solutions of polymers with large solids- »> proportion could have been applied advantageously close.

Example 7

Production of
Vinyl chloride graft copolymers

Using a 38 l stainless steel reaction vessel, which is manufactured in accordance with Betspiel 1 equipped, a graft copolymer is prepared as follows:

A solution of 72.6 g of polyvinyl alcohol in 3600 ml of deionized water is placed in the reaction vessel. 15.1 1 deionized water and 1816 g ethylene-vinyl acetate copolymer. which contains 26 percent by weight vinyl acetate (melt index = 3). After closing and cleaning the reaction vessel, as described in Example 1, 7264 g of distilled vinyl chloride are added, whereupon the reaction mixture is heated to 100.degree. Fully demineralized water is pumped in up to 35 kg / cm ^2.

Thereafter, a solution of tert-butyl peroxypivalate are (40 g of catalyst with 95 ° _o sodium ethanol diluted to 200 ml) was added into the reaction container, 20 ml, is stirred and the reaction mixture over 15 minutes. During this time, the polymerization proceeds to a reaction of 30 to 40 ″, as can be seen from the need to add water so that the reaction vessel remains essentially filled with liquid Polymerization 10 ml of the catalyst solution was added every 5 minutes; no further addition is necessary. The total reaction time is 90 minutes. The total concentration of the catalyst used for this experiment is 0.29 °, based on the weight of the vinyl chloride monomer charge.

After the polymerization is over. the copolymer is obtained, cleaned and as in the previous previous examples dried. The yield of copolymer (8626 g) is slightly higher than 95% Theory.

Extraction searches were carried out on this copolymer with hot cyclohexanone. It was found that the remaining, insoluble fraction (a copolymer based on ethylene vinyl acetate) contains at least about 60% chlorine, physical properties
the graft polymers

The physical properties of samples obtained by means of an injection molding machine using a copolymer are then determined. These samples are obtained after rolling and chopping up an Ansat2ss (100 parts of copolymer to 3 parts of stabilizer) using a Mini-Jector injection molding machine, model 65-HA 100 (Newbury Industries, Newbury, Ohio). Deformation conditions: cylinder temperature 177 ° C; Nozzle i65'17rC; Form: Raumtetr <peratiiir; Injection pressure: 84 kg / cm ² ; Deformation cycle 30 seconds (injection). 10 seconds (filling). 5 seconds (curing).

Table IX

Tensile strength, kg / cm ² 210 -:! 8O

Tensile modulus, kg / cm ² · 10 ³ 8.4 13.6

Elongation at break

(ASTM D-638-64 T) 40

Izod impact strength

cm · kg / cm

Notch (ASTM D-256-56) .. approximately 49-54.5 Distortion Temp. at

18.5 kg / cm ² . ⁰ C

(ASTM D-648-56) 46-49

Brittleness at low temperatures.

⁰ C (ASTM D-746-64 T) ... 10

Self-extinguishing flammability

In comparison, there is a mixture of 80 parts of the homopolymer according to Example 1 with 20 parts of the ethylene-vinyl acetate copolymer. which is wasted at 121 ⁰ C, crumbly and not firm. The mixture cannot be pulled off the roller mill as a tough skin. *

Mixtures of conventional polyvinyl chloride (reduced viscosity = 1.10) with 15 to 20 parts of the Ethylene-vinyl acetate copolymer ratios at 171 ° C rolled, peeled off as skin and deformed by means of pressure. Samples of this mixture have an average impact strength of about 8.15 to 10.9 cm · kg / cm Score.

Mixtures filled with calcium carbonate, asbestos and glass fiber are mixed, ^{ground at 1140 ° C. for 5 minutes and then deformed under pressure at 149 ° C. and 70 kg / cm 2} for a period of 5 minutes. The physical properties of these briquettes are according to ASTId 638-64 T as follows:

Tabel X 100
308
242
59 asbestos Glass
fiber Calcium carbonate 75
501
478
69 25th
401
312
66 Filling quantity | i> hr ....
Tensile strenght,
kj ^ crtt *
Tensile module,
k | j / cm ² -ΙΟ ³ ...
Dtstorsions'Temp.
at 18.5 kg / cm *,
(ASTM D-648-56) 50
28
108
57

Comparative experiment B
A. Manufacturing

The reaction vessel of Example 1 is charged with a solution of 4.8 g of polyvinyl alcohol in 1715 ml of water. Mach repeated pumping out of the oxygen and refilling of vinyl chloride up to Atmos phärenclruck 613 g of vinyl chloride are fed with stirring, and then ^{heated to 100 0} C, so that a pressure of 23.8 kg / cm ^{2 is} set. 4 ml of a 20% solution of tert-butylpiroxypivalate are then added with constant stirring. The start of the polymerization reaction is noticeable by a pressure drop. Every further 5 minutes, 2 ml of the solution of the peroxy compound are then pumped in again, so that after 120 minutes a total of i> 2 ml of the solution have been fed in, corresponding to a concentration of 1.7% of peroxy compound, based on the amount of monomer used. At this point in time, the reaction vessel pressure has dropped ^{to 7 kg / cm 2.} The reaction mixture is stirred for a further 15 minutes at 100 ° C., then cooled and the polymer is separated off by centrifugation. After the usual washing and drying, a yield of about 80 "is obtained.

This polymer is reddish brown in color and contains numerous hard, dark brown colored lumps, which indicates a material decomposition already during the polymerization.

ίο B. Testing of thermal stability

a) Both a sample of the polymer prepared according to Section A and a sample of the product from Example 1 are ^{heated to 150 °} C. in air, and the weight loss is then measured over 60 minutes. The results are shown graphically in FIG. 1, curve 1 relating to the comparative sample and curve 2 relating to the product according to the invention. It is evident that

jo the latter has a very high stability (weight loss maximum 0.5 "J for 60 minutes.

b) In a further stability test, both material samples are run at a speed of 3 C / Minute in the air, and the weight loss

* 5 lust is continuously followed. The results are shown in FIG. 2 reproduced. Curve 1 again relates to the comparative sample and shows that decomposition begins at below 150.degree. The sample according to the invention, on the other hand, only begins ^{to decompose at about 225 °} C., the weight loss being very small ^{even at 250 ° C.}

C. Test by Differential Calorimetry Analysis

In contrast, the Vergieichsprobe showed a second-order transition point (transition into the glass state) at 64 "C. The sample of the invention at a higher to 1O ⁰ C value (74 ° C) This fact suggests the better processing properties .- 'chaften.

For this purpose 2 sheets of drawings

409584/39

Claims (3)

Patent claims: ^). Branched, thermoplastic vinylchloride “fjgojymerisate” with CH ₃ and 3 to 14 CH ₂ C1 end groups on the branches per 1000 CH _? - uruppen and a content of at least 50 • ^ percent by weight vinyl chloride units, obtained I, by suspension polymerization of vinyl chloride. ^ rid, a mixture of vinyl chloride and a w 'comonomer or a mixture of vinyl chloride and a solid polymer graftable with this in the aqueous phase in the presence of monomer-soluble, free radical-forming catalysts at temperatures of 90 to 165 ° C and under increased pressure, characterized that they were obtained by polymerization at hydrostatic pressures of 28 to 350 kg / cm ² maintained throughout the reaction time. 2. Process for the preparation of vinyl chloride polymers containing at least 50 percent by weight vinyl chloride units by suspension polymerization of vinyl chloride, a mixture of vinyl chloride and a comonomer or a mixture of vinyl chloride and a solid polymer graftable with this in the presence of monomer-soluble, free radical-forming catalysts in the aqueous phase at temperatures from 90 to 165 ° C. and under increased pressure, as a result of which the polymerization is carried out for the entire reaction time at hydrostatic pressures of from 28 to 350 kg / cm ² . 3. The method according to claim 2, characterized in that the polymerization during the total reaction time with the polymerization vessel essentially completely filled with liquid performs.