DE2534781A1 - METHOD FOR MANUFACTURING POLYBLENDS - Google Patents

Description

DR. BERG DtPl.-ING. STAPF DIPL.-ING. SCHWABE DR. DR. SANDMAIR

PATENT LAWYERS

8 MUNICH 86, POST BOX 86 02 45 2534781

Attorney's file 26 249 \ AUG 4. 1975

MONSANTO COMPANY ST. LOUIS / MISSOURI / USA

Process for the production of polyblends

The invention relates to an improved process for the production of polyblends with low residual monomer contents and unexpectedly high impact strength with a polymerizable mixture of a monovinylidene aromatic monomer and a diene rubber in the block is partially polymerized beyond the phase inversion, whereupon-

t (089) 98 8272 8 Munich 80, Mauerkircherstraße 45 Banks: Bayerische Vereinsbank Munich 453100

70 43 Telegrams: BERGSTAPFPATENT Munich Hypo-Bank Munich 389 2623

983310 TELEX: 0524560 BERG d Postscheck Munich 65343-808

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the partially polymerized mixture is suspended in an inert liquid and the polymerization is practically brought to an end; the improvement consists in the use of a special catalyst system during the bulk and suspension polymerization of the process, namely the catalyst system has a half-life of less than 1 hour at 130 ^° C. and a ten-hour half-life at a temperature of 95-115 ° C.

It is known that polyblends made from rubber and aromatic monovinylidene hydrocarbons have significant advantages, since they result in preparations with good impact resistance for many areas of application. Different procedures have been proposed or used for the production of such polyblends, including emulsion suspension and bulk polymerization processes, as well as combinations thereof. Although graft copolymers produced in the block a monovinylidene aromatic hydrocarbon and rubber have useful properties, there is a practical limitation on this method in relation to the maximum attainable degree of conversion of the monomers to the polymer, since the viscosities are high and, as a result, a great deal of energy and equipment occurs when the reactions are over a very small one Degree after the phase inversion

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sion took place. Procedures have been developed in which the initial polymerization in the block to a degree of conversion beyond the phase inversion is carried out at which the viscosity is still within practical limits! then the prepolymerization syrup obtained becomes suspended in water or another inert liquid and the polymerization of the monomers is practical completely completed.

Polyblends made with aromatic monovinylidene monomers consist of grafted diene rubbers, can by means of masses / Suspension polymerization prepared in accordance with US Pat. No. 3,488,7 ^ 3 will.

The polyblends according to the invention are commercially available as highly impact-resistant Polystyrenes (HIPS) known. These HIPS polybiends are used in large quantities in the packaging industry for molded food containers. These types of use make a low residual monomer content in the finished product Polyblend required for food packaging approval to ensure. In the processes customary up to now, high temperatures and catalysts with longer half-life times were used used at higher temperatures to make the suspension polymerization practically complete lead and thus an unpolymerized residual monomer content

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in the finished polyblend of about $ 0.5.

These processes were unsuccessful, neither in reducing the residual monomer content of the polyblend nor for the Preservation of the quality of the rubber phase and the strength of the polyblend. Polymerization at a higher temperature and higher temperature catalysts cause excessive wetting of the rubber during the final Conversion of the monomers and lead to a lower swelling index and a lower quality of the rubber. Furthermore, the processes lower the molecular weight of the solid phase of the polyblend and lead at higher temperatures to further loss of strength. These earlier processes often resorted to subsequent degassing, e.g. by means of extrusion, in order to reduce the residual monomer content of the polyblend. The physical breakdown during extrusion however, worsened the properties of the polyblend even more.

The invention therefore relates to a polymerization process for the production of polyblends with the following process steps:

a) Solution of a graftable rubber-like polymer in a ^ r v-pj3ly ^ e ^ iabaren monomer preparation which at least contains an aromatic monovinylidene monomer,

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to form a polymerizable mixture,

b) bulk polymerization with stirring of this mixture until a partially polymerized mixture is produced with a grafted, inverted and dispersed rubber phase,

c) suspension of the partially polymerized mixture in an inert liquid

d) suspension polymerization in which the partially polymerized Mixture is polymerized to a higher degree of polymerization and

e) recovery of the suspended polyblend from this suspension,

the improvement being having a peroxide catalyst with a half-life of less than 1 hour at a temperature of 130 ° C and a 10-hour half-life is used at a temperature of about 95 to 115 ° C in steps b) and d), with step b) at carried out at a temperature of 95 to 125 ° C and thereby the polymerizable mixture up to a degree of conversion is polymerized from about 10 to 45%, and step d) at a temperature of 110 to 150 ° C, the partially polymerized mixture to a practically complete

Conversion is polymerized.

The type of catalyst, the amounts used, the time of addition, along with the temperature of catalysis and polymerization was found to be critical to the process.

Small amounts of catalyst are added during bulk polymerization to initiate solid phase polymerization and to obtain the proper degree of grafting of monomers as superstrate onto the rubber phase substrate so that a stable dispersion of rubber particles which are optimally smaller in size is obtained and thereby guarantee a high gloss, but also retain strength. The temperature during the bulk polymerization is maintained in a range of about 95 to 125 ° C, preferably at 100 to 115 ° C, in order to ensure a high molecular weight of the plague phase polymer of the aromatic monovinylidene monomers, as well as a high molecular weight graft phase in the rubber, so that a stable dispersion of the grafted rubber particles is obtained. The amount of catalyst used during the bulk polymerization step can be from about 0.01 to 0.2 weight percent of the polymerizing mixture, preferably from about 0.02 to 0.1 weight percent. The bulk polymerization stage can, depending on the amount of catalyst used,

Take 120 to 240 minutes.

After phase inversion of the rubber phase and after the rubber particles have been stabilized at 10 to 50%, preferably 20 to 35% conversion during the bulk polymerization step, larger amounts of catalyst are added during the suspension polymerization step so that the remaining monomers are converted . The catalyst can be added to the partially polymerized mixture for catalyzing the suspension polymerization before or after the suspension. The amounts of catalyst for the suspension step can be based on the partially polymerized mixture, preferably at from 0.18 to 0.22 Gew.l at 0.15 to 0.30 wt.%. The temperature of the suspension polymerization stage can be about up to 150.degree. C., preferably about 130 to 140.degree. The time cycle of the polymerization can last from 150 to 210 minutes, depending on the amount of catalyst used.

It has been found to be critical that the time / temperature cycle is sufficient in duration or magnitude so that when the final conversion occurs of the monomers from 80 to 100? is carried out, the catalyst has already largely decomposed and the crosslinking of the rubber particles is no longer catalyzed will.

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It has been found that if one during the suspension polymerization step operates at temperatures of 115 to 150 ° C, a matrix polymer with a molecular weight of obtained from about 180,000 to about 320,000 (average weight) with optimal impact strength, modulus and melt flow . And it is also ensured that the catalyst has been decomposed within the processing period and in the the rubber is not crosslinked in the final conversion stages.

Critical the half-life of the catalyst during the mass polymerization step and a half-life of less at 130 ⁰ C over an hour is used in accordance with the second proviso that the catalyst has a 10-hour half life at temperatures from 95 to 115 C. Catalysts that are too active at low temperatures, for example peroxides such as lauroyl, benzoyl, cyclohexanone, etc., and have 10 hour half-lives at less than 95 C, are not used because temperature control during the bulk polymerization step is difficult and the Control over the polymerization can be lost. Catalysts are therefore used which have the time / temperature and half-life properties that are desirable according to the invention in order to ensure optimum polymerization and grafting rates for the polyblend process, in accordance with the improved technical time /

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Temperature cycles used,

Catalysts for high temperatures, such as di-tert-butyl peroxide, with a 10-hour half-life at 126 ° C. and a half-life of 6.4 hours at 130 ° C. make it necessary to carry out the polymerization at higher temperatures (155 ° C. to 165 ° C.) ⁰ C) is carried out so that the decomposition of the catalyst is ensured. Such catalysts and time / temperature cycles reduce the molecular weight of the solid phase and cause crosslinking of the rubber phase.

With the catalyst system and time / temperature cycle according to the invention, the monomer conversion can be up to 99.8% and more, which results in less than $ 0.2 less monomer residue in the polyblend, however unexpectedly retained the quality of the rubber phase and the strength of the polyblend. The mechanism is not fully explainable, since in known processes in which high conversion rates of, for example, over 905? were forced, the rubber phase was excessively crosslinked, the rubber had a lower swelling index and the polyblend had poor strength.

In the polymerization stages of the improved mass /

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In suspension polymerization processes, free radical generating catalysts of a certain organic peroxide type are used. It is critical that the catalysts have a half-life of less than one hour at 130.degree. C. and, at the same time, a 10-hour half-life at temperatures of 95 to 115.degree. (All half-life determinations are made in benzene at concentrations of 0.1 to 0.2 mol). In "Modern Plastic Encyclopedia" 1972-1973, Volume 49, McGraw-Hill Company, New York, on pages 459-462 there is a compilation and description of the commercially available peroxides according to their half-lives. The above critical specifications of the catalysts are known to those skilled in the art, and catalysts conforming to these specifications can be manufactured or purchased commercially. In the inventive method, the residual monomer content of the polyblend can be less than 0.2 wt.% Reduced, and the strength and the elongation at break can be improved if a specific type of catalyst and time / temperature cycles are used in the inventive polymerization steps, in Verlgeieh to other catalysts , Catalyst combinations or systems, as they were known from previous processes. This is illustrated in the examples below.

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Examples of such peroxides are the peroxyesters, e.g. tert-butyl peracetate, tert-butyl perbenzoate, tert-butyl percrotonate, 2,5 dimethyl-2,5-bis (benzoylperoxy) hexane, aryl substituted tertiary butyl perbenzoates, e.g., tertiary butyl peroxy-2-methylbenzoate; Alkyl peroxides, e.g., dicumyl peroxide, di-tert-butylperoxy-3,3,5-trimethylcyclohexane; Peroxycarbonates, e.g. tert-butyl peroxyisopropyl carbonate, etc.

The amount of rubber used will generally be between approximately 2 and 20%, based on the total weight of polymerizable monomer preparation and rubber substrate, and the amount of monomer accordingly between approximately 98 and 80%. In the preferred polymerization mixtures, the above amounts are approximately between $ 5 and $ 15 and $ 95 and $ 85, respectively.

Although the amount of the polymeric superstrate grafted onto the rubber substrate is between 10.0 parts by weight per 100.0 parts of substrate and 250.0 parts by weight per 100.0 parts and even more are preferred Graft copolymers generally have a superstrate to substrate ratio of about 50 to 200: 100, most preferably about 70 to 150: 100. With graft ratios of more than 50: 100 is obtained one generally has an extremely favorable degree of improvement in various properties.

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The rubbery polymer or substrate is dissolved in the polymerizable preparation, which consists of monomers, catalyst and other optional ingredients. This polymerization mixture is then polymerized in the block by heating to a temperature of about 95 to 125 ° C. for a period of about 1 to 4 hours and at a pressure of 1.1 to 8.1 kg / cm until one part the monomer has polymerized at least to such an extent that phase irradiation occurs; this proportion is generally 10.0 to 45.0% by weight . Conventional agitation is used during the process to help distribute heat during the reaction. The time required for this partial polymerization depends on the catalyst, the amount of catalyst, the pressures and temperatures used, and the particular monomers and their ratio to one another. In general, it is preferred to carry out such a prepolymerization process to the conversion of about 20.0 to 35.0 sew. % of the monomers to be carried out.

Those skilled is known that in the solution of this diene rubber in the monomers described the rubber during the Po-l _v yme.r is ation forms a separate rubber-monomer with the Mqnomer, and the polymerized polymer Eirie rPolymer-monomer with the Monomer. If the polymer-monomer phase becomes larger during the polymerization,

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ORIGINAL INSPECTED

Inverts and disperses the rubber monomer phase as rubber monomer droplets in the polymer / monomer phase. When the polymerization mixture is completely polymerized, either by means of bulk or suspension polymerization, for example polymerize the Rubber / monomer droplets to form individual rubber particles which are dispersed in the polymer phase, with a polyblend is formed by grafted rubber particles in the polymer phase. The rubber particles are made with polymer molecules grafted and also contain entrapped polymers of the monomers described.

It was found possible to analyze the amount of total entrapped polymer phase and grafted polymers. The finished polymerized polyblend product (Ig) is dissolved in a 50:50 solvent (10 ml) consisting of dimethylformamide and methyl ethyl ketone, which dissolves the matrix of the polymeric phase and leaves the rubber phase dispersed. The rubber phase is separated from the dispersion as a gel by means of a centrifuge and ^{dried in a vacuum oven for 12 hours at 50 °} C. and weighed as a dry gel.

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% Drying gel
In polyblend

Weight of the drying gel ₁₀₀ Weight of the polyblend

% Grafting and)
Inclusions In)
Rubber)

% Dry gel - % rubber % rubber *

χ 100

Percent rubber determined by iodine monochloride analysis of the polyblend

Parts by weight)

of graft polymer)

and inclusion polymer)

per unit weight)

of rubber)

% Dry gel - % rubber percent rubber

According to the invention, about 0.5 to 3.5 g are included and grafted polymers per gram of diene rubber are preferred.

The amount of polymer entrapped or grafted in the rubber particles may vary and in the grafted Diene rubber in an amount of about 0.5 to 3.5 parts per rubber portion, preferably in an amount of about 1.5 to 2.5 parts per portion of rubber may be present.

That consisting of the partially polymerized preparation Syrup is mixed with water in the presence of a suspending agent such as acrylic acid / acrylate interpolymers according to the ÜS-PSs 2 9 ^ 5 013 and 3 051 682. It

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? B3u7 81

Secondary dispersion aids can also be added to obtain the desired suspension of the syrup in water. The suspending agent is preferably added to the water, although it can also be added to the monomers from the beginning or during the initial polymerization. This suspension is stirred and heated for two to four hours at a temperature of about 100-150 ^° C. in order to obtain practically complete polymerization of the monomers contained therein. Preferably, this further polymerization is carried out at a temperature of about 115 to 140 ° C. for a period of two to three hours, depending on the catalyst and the amount thereof used. After the reaction has ended, the polymer beads are centrifuged off, washed and dried.

In addition to the monomers to be polymerized, the preparation can contain ingredients such as stabilizers, molecular weight regulators, etc. included. The polymerizable monomer preparation contains one or more aromatic Monovinylidene hydrocarbon monomers and may additionally contain smaller amounts, i.e. up to 20%, of a monomer which can be polymerized therewith. Those are preferred Compositions in which the polymerizable monomer preparation aromatic monovinylidene hydrocarbons and preferably contains styrene, although minor amounts of

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the copolymerizable monomer having a g £% wiss can graze added n .Vorteil for certain compositions contain less than about 5 wt.%.

β-

Examples of the monovinylidene aromatic monomers are Styrene; monoaromatic alpha-alkyl monovinylidene compounds

C's

gen, ziB. alpha-methylstyrene, alpha-ethylstyrene, alpha-meth / vinyltoluene, alpha-methyl dialkyl styrenes, etc .; Ring-substituted alkylstyrenes, e.g. vinyl toluene, o-ethylstyrenes, p'-ethylstyrene, 2,4-dimethylstyrene, etc .; ring-substituted Halostyrenes, e.g. o-chlorostyrene, p-chlorostyrene, o-bromostyrene, 2,4-dichlorostyrene, etc .; Ring alkyl or halogen-substituted styrenes, e.g. 2-chloro-4-methylstyrene, Hjo-dichloro - ^ - methylstyrene, etc .; Vinyl naphthalene; Vinyl anthracene, etc. The alkyl substituents generally have one to four carbon atoms and can include isopropyl and isobutyl groups. If desired, mixtures of such aromatic monovinylidene monomers can be used be used.

«F -

Examples of the monomers used or polymerized with the monovinylidene aromatic monomers are alpha- or beta-unsaturated monobasic acids and their derivatives, such as acrylic acid, methyl acrylate, Ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate,

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G 0.9 8 Ö8 / 09 2 4 ORIginal ^ spectso

Fatty acid acrylates with long chains ( ^c ₁₂ -i8 ^ methacrylic acid and its corresponding esters, e.g. methyl methacrylate, stearyl methacrylate, acrylamide, methacrylamide, vinyl esters, dialkyl maleates or fumarates such as dimethyl maleate, diethyl maleate, dibutyl maleate, the corresponding fumarates, etc .; alkenyl nitrile monomers, e.g. methacrylonitrile, etc. The preferred polymerizable monomer formulations contain at least 10 wt.? monovinylidene aromatic monomers and preferably at least 50 wt.% thereof.

It is known that it is often desirable to add molecular weight regulators such as mercaptans, halides and terpenes in relatively small proportions by weight, namely in the order of magnitude of from 0.001 to 1.0% by weight , based on the polymerizable material. In addition, it may be desirable to include relatively small amounts of antioxidants or stabilizers, such as the conventional alkylated phenols, although these can also be added during or after the polymerization. The preparation may also contain additives such as plasticizers, lubricants, dyes and other non-reactive preformed polymer materials suitable for or dispersible therein.

Examples of the different types of rubbers on which

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2 5 3 U 7 8

during the polymerization, the polymerizable monomer preparation for the production of graft copolymers can be grafted are diene rubbers, natural rubber, ethylene / propylene / terpolymers, acrylate rubbers, Polyisoprene rubbers and their mixtures, as well as interpolymers of these substances with one another or with other copolymerizable monomers.

The preferred substrates, however, are diene rubbers (including mixtures of diene rubbers), ie each rubbery homopolymer (a polymer having a transition temperature of the second order of not more than ⁰ ° C, preferably not more than -20 ⁰ C, according to ASTM Test D -746-52T) from one or more of the conjugated 1,3-dienes, for example butadiene, isoprene, piperylene, chloroprene, etc. These types of rubber include copolymers of conjugated 1,3-dienes with up to an equal weight fraction of one or more copolymerizable ones Monomers which are unsaturated with respect to monoethylene, such as aromatic monovinylidene hydrocarbons (e.g. styrene; an aralkylstyrene such as o-, m- and p-methylstyrenes, 2,4-dimethylstyrene, the arylated ethylstyrenes, p-tert-butylstyrene, etc .; an alpha-methylstyrene, alpha-ethylstyrene, alpha-methyl-pmethylstyrene, etc .; vinyl naphthalene, etc.); aromatic aryl halo-monovinylidene hydrocarbons, for example the o-, m- and p-chlorostyrenes, 2,4-dibromostyrene, 2-methyl-4-chlorostyrene, etc.); Acrylonitrile, methacrylonitrile,

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2Β3Λ7Β1

Alkyl acrylates (e.g. methyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, etc.), the corresponding alkyl methacrylates; Acrylamides (e.g. acrylamide, methacrylamide, N-butyl acrylamide, etc .; unsaturated ketones (e.g. vinyl methyl ketone, Methyl isopropenyl ketone, etc.); alpha olefins (e.g. ethylene, propylene, etc.); Pyridines; Vinyl esters (e.g. vinyl acetate, vinyl stearate, etc.); Vinyl and Vinylidene halides (e.g. the vinyl and vinylidene chlorides and vinylidene chlorides and bromides, etc.); and similar.

Although the rubber can contain up to about 2.0% of a crosslinking agent based on the weight of the of the rubber-forming monomers, can cause problems in solving the rubber in the monomers for the crosslinking Raise graft polymerization reaction. Furthermore can excessive crosslinking lead to loss of rubber properties.

A preferred group includes those rubbers which consist substantially 75.0 to 100.0 wt.% Of butadiene and / or isoprene and up to 25 wt.% Of a monomer of the group consisting of aromatic Monovihylidenkohlenwasserstoffen (eg, styrene) , and unsaturated nitriles (e.g. acrylonitrile) or mixtures thereof. Butadiene homopolymers are particularly advantageous substrates

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ORIGINAL INSPECTED

or interpolymer of 90.0 to 95.0 wt. % butadiene and 5.0 to 10.0 wt. % acrylonitrile or styrene.

A particularly preferred group of rubbers are the stereospecific polybutadiene rubbers, which are formed by the polymerization of 1,3 butadiene. These rubbers have a cis isomer content of about 30-98% and a trans isomer content of about 70 to 2% and generally contain at least about 85% polybutadiene formed by 1,4 addition and no more than 15% that was formed by addition of 1,2. The Mooney viscosity of the rubber (ML-4, 100 ^° C.) can be between

about 20 and 70, at a transition temperature of the second order
Test D-746-52T.

second order of about -50 ⁰ C to -110 ° C, according to ASTM

Polyblends made from Dlen rubbers grafted with aromatic monovinylidene monomers can be

Suspension polymerization process according to U.S. Patent 3,488,713 getting produced. The mean particle size of the dispersed rubber particles can be between 0.1 and 7.0 µm preferably between 1.0 and 3.0 µm. The mean particle size is determined using a photosedimentometer that of Graves, M.J. et al published procedure "Size Analysis of Subsleve Powders Using a Centrifugal

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Photosedimentometer ", British Chemical Engineering 9: 742-7 ^ 4 (1964). A Model 3000 Particle Size Analyzer used by the Martin Sweets Company, 3131 West Market Street, Lousville, Kentucky. Of the Rubber is grafted with the described monomers and the grafted polymer preferably has the same Monomer composition as the polymer in which the grafted rubber is dispersed.

The swelling index of the particles of the rubber phase is important for the final! Properties of the HIPS polyblend. A low swell index of less than 9 indicates that the rubber phase has been excessively crosslinked by the monomer is, while this polymerized in step d) to a polymeric phase in the rubber monomer particles, in particular, when the conversion of the monomer had already progressed more than 90%. In general, the conversion follows of the monomer to the polymer in the inclusions the rate of conversion of the monomer to the polymer in the Monomer-polymer phase carried out in steps b) and d). For conversions beyond about 90Ji However, the polystyrene chains are less mobile and there are fewer monomers to continue the chains, so that the resulting chain radical transfers the chain to the rubber molecules and crosslinks them. As already

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As stated above, see the catalyst systems according to the invention and time / temperature cycles of steps b) and d) half-life properties that ensure that the catalyst activity is kept to a minimum in the last polymerization stages and that no excessive Crosslinking of the rubber phase takes place. The method according to the invention provides a step d), in which a grafted rubber phase with a swelling index of preferably about 9 to 25 and most preferably of about 9 to 20 arises.

The swelling index of the rubber phase is determined by dispersing the gel test for hours Gels in toluene. The swollen gel is centrifuged and the toluene drained. The wet gel is weighed.

Swelling index = weight of the wet gel

Weight of dry gel

Some preferred embodiments are described below, the usefulness of the invention Process in reducing the residual monomer content in HIPS polyblends show, unexpectedly their Strength increases.

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example 1

A polymerization mixture of about 13 wt.% Butadiene rubber having a 1,4 ice content of about 35 wt.! " and a Mooney viscosity of 55 dissolved in about 87 % styrene monomer is placed in a suitable reaction vessel. After the addition of about 0.1 wt.% Of a di-tert-butyl peroxide catalyst and about 0.06 Gew.2 "a tert-dodecyl mercaptan chain transfer agent, based on the polymerization, the vessel is cleaned by means of a nitrogen stream of oxygen and the The polymerization mixture was stirred and heated under reflux conditions at 115 ° G for 195 minutes so that the heat was distributed and about 30% of the styrene monomer would polymerize.

The partially polymerized syrup obtained is then dispersed in heated water in the appropriate suspending agent are suspended. The suspension is then heated to 160 ° C. and stirred in order to distribute the heat and maintain the suspension for 170 minutes, which is sufficient in order to achieve a practically complete conversion of the monomers to the polymer. Finally the suspension is cooled, centrifuged, washed and dried to give the polyblend particles as beads.

The suspension polymerization is carried out with a ratio

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Water to partially polymerized mixture of about 1: 1 carried out. This ratio can be varied between 2: 1 and 4: 5, but about 1: 1 is preferred. An antioxidant (trisnonylphenyl phosphate 0.15 wt %) is used along with 0.01 wt % stearic acid in the bulk polymerization step. The suspending agent is a polymer of 95.5 mol # acrylic acid and 4.5 ο15ί 2-ethylhexyl acrylate with a specific viscosity of 4.0 determined in an aqueous solution and described in US Pat. No. 3,051,682. The suspending agent is described in US Pat amounts of about 0.18 wt.% based on the water together with 0.24 wt.% Epsomsalzen and 0.15 wt.% of sodium sulphate is used.

The about 13% polybutadiene rubber wt. Containing PoIyblendperlen were mixed with polystyrene homopolymer to obtain a polyblend having about 5.5 wt.% Rubber, this was molded into test bars for impact resistance test in accordance with ASTM D-256-56 and samples for testing of physical properties.

Examples 2 to 10

The procedure of Example 1 was followed using the inventive catalyst systems and time / temperature cycles repeated. The preparations and ingredients used

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are listed in Table I for Examples 1-10 along with the test results.

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Table I.

preparation
procedure
Test results 1 2 3 4th 5 6th 7th 8th 9 10 Bulk polymerization
Step: weight!? Styrene 87 87 87 87 87 87 87 87 87 87 Dlen rubber 13th 13th 13th 13th 13th 13th 13th 13 ¹² 13th tert-dodecyl mercaptan 0.06 0.06 0.06 0.06 0.09 0.02 0.06 0.06 0.06 0.06 Polymerization
temperature (C) 115 115 115 115 95 125 115 115 115 115 Polymerization time
(MIN.) 195 195 195 195 195 180 195 195 195 I.
stopped- _Μ Catalysts (wt.?) th SS σ ^
ι

εο di-tert-butyl peroxide ² 0.10 0.10

NJ X

^, Lauroyl peroxide · ^ 0.10

Ii
tert-butyl peracetate 0.015

tert-butyl perbenzoate ⁵ 0.025 0.025 0.20 0.01 0.025 0.025

Suspension polymerization

»Isation

Polymerization
temperature C 160 140 l40 140 130 130 150 IiIO 140 Polymerisation
time (min.) 170 170 170 170 210 200 150 170 170

Table I (port setting)

preparation
procedure
Test results 1 2.7 2 2.5 3 0.18 4th 0.18 VJi 0.15 6th 0.30 7th 0.15 8th 0.18 9 0.18 1 Catalysts (wt.?) ro Di-tert-butyl peroxide 186 196 2.1 2.3 1.7 2.0 2.2 2.5 2.0 t Lauroyl peroxide 42 39 tert-butyl peracetate 2.07 1.98 257 272 286 270 210 230 230 tert-butyl perbenzoate 7.3
0.44 8.0
0.43 35.7 36.8 39.7 35.1 35.8 37.4 32.5 Properties of the
Poly blend beads 1.75 1.83 2.05 1.70 1.75 1.88 1.50 <£> Rubber particles
size (T) 10.5
0.13 9.7
0.14 13th
0.19 12th
0.17 9.5
0.19 10.6
0.19 12.0
0.16 Matrix molecular 3 weight χ 10 "" 3 co
ISJ Gel wt. JS Grafting and a
conclusions' Swelling index rubber
O
Residual monomer weight i ⁰

Polyblend properties ^

Impact strength ¹⁰ elongation at break

1.17 1.15 1 * 85 1.80 1.60 1.70 1.60 1.65 1.70 NJ cn 34 37 53 48 40 45 40 40 42 OO • Ρ--

2 B 3 L 7 8

1. Linear polybutadlene rubber with about $ 35 ice 1.4 Content (Mooney viscosity 55)

2. half-life at 130 ⁰ C is 6.4 hours, 10-hour half-life at 126 ° C.

3. Half-life at 85 ° C is 0.5 hours, 10-hour half-life at 62 ° C.

4. half-life at 130 ° C 0.33 hours, 10-hour half-life at 102 ⁰ C.

5. half-life at 130 ⁰ C 0.55 hours, 10-hour half-life at 105 ° C.

6. Weighted average molecular weight

7. Grafting and inclusions in rubber phase particles as parts / parts of rubber.

8. Residual Monoraere - Ig polymer dissolved in 10 ml tetrahydrofuran, of which 5 µl injected into a chromatograph and the styrene monomer relative to styrene and one internal standard of 1 ml butyl cellosolve / 200 ml Tetrahydrofuran analyzed as a percentage by weight of the polyblend.

9. Polyblend diluted with homopolymer styrene with the same molecular weight as the matrix phase to a rubber content of 5.5% by weight of the polyblend.

10. ASTM D-256-56

11. ASTM D-2256-D-I3

12. Linear polybutadiene rubber with about 91% ice,

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1.4 content (Mooney viscosity 42) Table I shows:

Examples 1-2: when using di-tert-butylperoxil with a 10-hour half-life at 12 ° C., the residual monomer content is high (0.44%) and the swelling index is low, (^ 9), which means low impact strength and elongation at break results.

Examples 3 to 7 '. using tert-butyl perbenzoate with a 10-hour half-life at 105 ° C with variation of the time / temperature and concentration ranges results in an unexpectedly low residual monomer content (^ X) ₃ 20%) and a high swelling index 0> 9), which leads to unexpectedly high impact strength and elongation at break.

Example 8: when using tert-butyl peracetate with a 10-hour half-life at 102 ⁰ G, the same desirable properties as tert-butyl perbenzoate yield with a 10-hour half life in the range of 95 to 115 ° C

Example 9: when using a linear diene rubber with a 1.4 isomer content of about 95 $, a polyblend according to the invention with unexpectedly good physical properties results.

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see properties and at the same time low monomer content and high swelling index.

Example 10: when using lauroyl peroxide with a 10-hour half-life at 62 ° C., temperature control was lost under the conditions according to the invention and the process had to be stopped with hydroquinone (SS). These catalysts must be used at low temperatures in the range of 80 to 90 ° C in long polymerization cycles in order to achieve a high degree of conversion, which, however, has little commercial utility.

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609808/0924

Claims (5)

Claims a) solution of a graftable rubber-like polymer in a polymerizable monomer preparation which at least contains an aromatic monovinylidene monomer to form a polymerizable mixture, b) bulk polymerization with stirring of this mixture until a partially polymerized one is produced Mixture with a grafted, inverted and dispersed rubber phase, c) suspension of the partially polymerized mixture in an inert liquid d) suspension polymerization of the partially polymerized mixture to a higher degree of polymerization and e) recovering the suspended polyblends of this suspension, characterized in that a peroxide catalyst having a half life of less than 1 hour at a temperature of 130 ⁰ C and a 10-hour half-life at a temperature of about 95 to 115 ° C in steps b) and d) is used, wherein step b) is carried out at a temperature of 95 to 125 ° C and the polymerizable mixture up to a degree of conversion of about - 32 - 609808/0 9 24 10 to ^ 5? is polymerized, and step d) at a temperature of 110 to 150 ⁰ C, wherein the partially polymerized mixture is polymerized to a practically complete conversion, the grafted rubber having an average particle size of 0.1 to 7.0 µm, a swelling index from 9 to 25 and the rubber has 2 to 20 wt. the polymerization preparation contains. 2. The method according to claim 1, characterized in that the catalyst in step b) in Amounts of 0.01 wt. up to 0.20 wt.?, based on the polymerizable mixture, and in step d) in amounts of 0.15 to 0.30 wt.?, based on the partially polymerized Mixture, is used and the polymerization is carried out to a conversion of at least 99.8 will. 3. The method according to claim 1, characterized that the aromatic monovinylidene hydrocarbon is styrene, arylhalostyrene, aralkylstyrene, Alpha halogen styrene, beta halogen styrene, alpha alkyl styrene, Is beta-alkyl styrene or a mixture thereof, and that the graftable rubber polymer is a diene rubber. 4. The method according to claim 1, characterized - 33 - 609808/0924 shows that the peroxide catalyst is tert-butyl peracetate, tert-butyl perbenzoate, tert-butyl peroxycrotonate, 2,5-dimethy1-2,5-bis (benoylperoxy) hexane, di-tert-butyl diperoxyphthalate, dicumyl peroxide, tert-butyl peroxyisopropyl carbonate, di-tert-buty1-peroxy 3,3,5 trimethylcyelohexane, tert-butyl peroxy-2-methylbenzoate, tert-butyl peroxy-2-methoxybenzoate or a mixture thereof. 5. The method according to claim 1, characterized in that step b) has a time cycle of 120 to 240 minutes and step d) a time cycle of Has 150 to 210 minutes. 609808/0924