DE1595209A1 - Impact-resistant graft copolymers - Google Patents

Description

84oO Beverly Boulevard Los Angeles 54, California, U. S. A.

Impact-resistant graft copolymers.

The invention relates to new graft copolymers which are made from a moivinyl aromatic compound and a rubber-like material, in particular impact-resistant resins of the polystyrene type made from a linear polybutadiene rubber with a 1.4 content of at least yrf . The graft polymerizate resins according to the invention have excellent physical properties.

It has been known in the art to make chewy modified polymers of vinyl aromatic compounds such as styrene, methyl styrene and the like with various vulcanizable rubber-like materials. The graft copolymers obtained have varying physical properties depending on the rubber type and - in some areas - of the particular applied Verfahri dependence · «. In general, the prior art the rubber and process conditions selected to be safe to be that a certain physical property like higher Melt flow or high impact strength is achieved. Unfortunately, So far the technology has had one or two physical properties highlighted at the expense of other very important physical properties. For example, mixed polymer

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Resins that have been purposely made with the aim of increasing the Serj.-Tiv'lE flux , generally speaking, the high impact strength leaves a lot to be desired and vice versa. They are different resins. have been proposed which have excellent melt flow and impact strength values, but which have inferior low temperature and thermal deflection properties for many low-temperature tar; niche applications are unacceptable. On the other hand, some are. Interpolymer resins have been deficient in such properties as tensile elongation and transparency. ■ '

The use of certain commercially available rubbers has raised some problems with regard to the process itself or the equipment used for handling or polymerizing. For example, it was found that certain? It chewed somewhat as a result of impurities found in it. This requires the use of either a special non-corrosive device, such as stainless steel, or an expensive cleaning device and additional cleaning steps . Other rubbers only give technically acceptable products when Ahren in a special Polymerisationaverf instead be used in other known methods, eg Massepoly merlsation rather than suspension polymerization. ~ 'the term "ausgewogeiie physical properties ¹ * and" balanced properties "as in the written description and claims taken in conjunction with Mixed polymer resins are used, should denote Mi schpolyrneri satharze ,, which are excellent *. “Have low temperature strength and heat deflection values.

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also have excellent elongation and transparency properties. It goes without saying that the resin has tensile strength and flexibility Have temperature and hardness values which are comparable to the polystyrene-type chewable resins currently available on the market. Kit other hoardings, the Mlsehpolyerisat resins have a unique · combination of properties, which to leads to improved processability.

It is an object of the present invention to provide a heart type compound of a graft copolymer which has excellent physical properties and processability properties.

Another object of the present invention is to provide a resinous graft copolymer composition which Is characterized by balanced physical properties.

% s 1st another object of the present invention, a ten kautsehukfflodifiziertesPolyetyrolharz old excellent Sohlagfestigkeits-, Sohmelzflui- Tiefentenperaturfestlgkeits- and Wärmeblegungseigensohaf be shuttered.

It is another object of the invention to provide a rubber modified one To provide graft copolymer which can be readily made in a variety of polymerization processes with excellent properties being obtained.

It is yet another object of the present invention to provide a chew modified graft copolymer of a nonovinyl aromatic To create a connection that is more economical and without the

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Turning a non-corroding special direction or pre-cleaning stages can be produced.

Unfortunately, these and other goals result from the following description the invention.

According to the present invention, it has now been found that excellent Kautsohukmodifleierte, monovinylaromatic graft polymerizate can be obtained by using linear polybutadiene with an ois-1,4 content of at least J50 # as the rubber component. The linear polybutadienes which are used in the preparation of the graft copolymers according to the invention have a cis-1,4 content which is in the range from about 50 to 9%, and preferably about 35 to 60%. The molecular weight of the linear polybutadiene is at least 15,000. The Mooney Vlskosität of the linear polybutadiene ML-4 at 100 ⁰ C (ASTM-D-927-55T) generally ranges from about 20 to 90, and preferably from about 40 to 60. A commercial grade linear polybutadiene having a cis-l, 4 content of about 35 # had a Mooney value of about 55. Polymerization blends containing linear polybutadiene are much less viscous than blends containing common rubbers, as discussed below. It has generally been found that commercially available linear polybutadiene rubbers having the aforementioned properties contain mainly 98-100 # polybutadiene excluding the common stabilizers, and it has been found that any impurity is certainly below the level of an impurity. Indeed, it has been found that a water extract is essentially

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was; thereby becoming a non-corrosive operation during In addition, it was found that almost 9% of outer double bonds in the linear polybutadiene are possible in the case of handling and polymerization internal double bonds were, with only about% in pendants Vinylgruppeη were present. The high degree of purity and unsaturation, which in the linear ^ οIybutadieneη, which in the production of the new graft mixes & pölymerisate used according to the invention exist? is are important Properties, which are among the outstanding, achieved Contributing Results., The importance of purity is discussed above while the high degree of unsaturation the excellent plugging and ease with which it Grafting occurs in the practice of the present invention, Seems to facilitate · It was also unexpectedly found that linear polybutadienes with the aforementioned properties in smaller amounts than the usual rubber components are used can be if you have a graft copolymer resin with excellent properties.

In another useful feature of the invention, it has been found important to have the linear polybutadiene component in the graft copolymer in an average particle size of less than about 6 microns. The general range is about 0.2 to 6 microns * with a preferred average particle size is about 0.5 to 2 microns. The actual particle size may range from less than 0 _r 2 to hand up to about IO microns * It should be understood, however, that linear polybutadiene actually a certain

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May contain a percentage of particles which are less than 0.5 microns in size. Indeed, in some cases the presence of these smaller particles is beneficial in that they lead to improved processability and improved surface properties. " These further advantages ^: are achieved without the other properties discussed above being adversely affected.

The amount of linear polybutadiene used in the manufacture The graft copolymers used according to the invention are generally in the range from about 5 to 35% by weight, preferably about 5 to 15% by weight, based on the total weight of the udischpolymerisatharzest »

The monovinylaromatic compounds which can be used in the preparation of the rubber-modified polymers according to the invention include monovinylaromatic compounds in which the vinyl radical or the ethylenically unsaturated radical is located directly on a carbon atom of the aromatic nucleus. Styrene is the preferred monovinyl aromatic compound used in this process. Examples of other compounds which can be used herein which are alkyl and halogen derivatives of styrene are p-, m- and o-methylstyrenes, p-, m- and o - Aöhy! Styrenes, p-isopropylstyrene, o-, p- and m-chlorostyrenes, ar-dimethylstyrenes, ar-dichlorostyrenes, ar-methyl-ar-ethylstyrenes, ar-methyl-a-chlorostyrenes, ar-diethylstyrenes, p-fluorostyrene, p-bromostyrene, ar-methyl-ar-isopropylstyrenes, alphajMethylstyröl, 1,3-methoxystysol, p-tert, -butylstyrene, p-cyclohexylstyrene, p-MethyX-alpha-methy! styrene,

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Ar-aimethyl-alpha-methylstyrene, 3,4-i) iciloro-alpha-methylstyrene or p-isopropyl-alpha-methylstyrene, or mixtures of these compounds with styrene or with one another. Alpha-Mfcthylstyroi is the preferred replacement for small amounts of styrene, for _e B _o 3 to improve to 35% "to the physical .uijensciiaften such as heat resistant wedge ;, ,, monitoring the wide Ivlerkmal the Br invention Covers the vinyl aromatic ^ compound is from about 65 to 973ew% of the total weight of the i'fropfmischpolj never risat s and according to the more preferred features it includes; about 65 to 95% o For reasons of convenience, the invention is explained in detail on styrene as the moiiovinyl aromatic compound. However, it should be noted that the other ocen monoviny aromatic compounds combined oaer idcaiin jü by xaono vinylaromatic Yerbindutiijen used throw cones to produce the new graft copolymers according to the invention

The rubber modified polystyrene resins of the invention can also use small amounts of various additives, such as iCette regulators used in polymerization, antioxidants, Lubricant Uodgl · contain »Generally exceeds the total amount of these additives is not 6% by weight of the total weight of the graft copolymer and is preferably less than about 3% by weight.

There can be various aliphatic or aromatic mercaptans can be used as the iCettenreglex. Examples of this are tertiary dodecyl mercaptan, lauroyl mercaptan, honey mercaptan, Becylmerkaptan and other alkylmerkaptana, rich alkyl

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have radicals with preferably 6 to 24 carbon atoms, or mixtures of the above or higher mercaptans. In similar- ' Rather, aryl mercaptans with aryl radicals, as above were mentioned, also useful as chain regulators in the reaction «, The alkyl mercaptans, which contain 10 or more carbon atoms are particularly preferred »These chain regulators are used in amounts from about 0.01 up to a maximum amount of 0.2 GewjS used.

It has also been shown to be beneficial in a small amount up to about 5% by weight and preferably from about 0.5 to 2% by weight, based on the total weight of the copolymer, to use a substance that can act as a scimper. Small amounts of lubricants, such as paraffin wax or mineral oil, improve tensile strength and elongation. Other lubricants that Esters or metal salts of saturated higher fatty acids, e.g., those containing 16 or more carbon atoms in the alkyl radical of the acid, such as butyl palmitate, Butyl stearate, amyl palmitate, amyl stearate and hexyl stearate It is preferred that the lubricant be compatible with the graft copolymer and not be unsaturation and is therefore inert in the polymerization reaction. Another job of the lubricant is to remove it of objects made from the graft copolymer can be made to ease out of the shapes.

It is also suitable antioxidants into ^M narrow from about 0 to 1.0 wt% or more, and preferably in one of lvlenge

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about 0.05 to 0.2 Gevf / o are added · Examples of antioxidants are trisnonylphenylphasphite (Polygard) and substances • of the phenolic type such as 2,6-di-tert. ~ butyl-4-methylphenol (Ional) ₀

It will be understood that the use of a particular antioxidant or the use of any of the other additives mentioned herein is not critical. Moreover, it is also believed that the amount of additives used will vary over a wide range they only need to be used in an amount sufficient to accomplish their ordinary puncture, i. _e . Prevention of oxidation, stabilization and lubrication *

As stated above, the invention is various Graft polymerization process for making chews sohukmodmfizier Polymers applicable For a more detailed explanation of the invention, it is in detail in connection with a Number of such processes described. Generally speaking, these processes include the use of an initial prepolymerization step a, wherein the preferable particle size of the Rubber is set, which is followed by the transfer to a second polymerization stage, in which the necessary grafting and networking takes place and where the conversion is carried out substantially completed or the desired degree of conversion achieved »However, it should be understood that the following Descriptions and the associated special designs are presented for illustration only and certain preferred methods of practicing the present invention

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to illustrate.

One of the polymerization processes that can be used here is a bulk solvent process in which an alkyl substituted benzene, which has at least one alkyl group with at least 2 carbon atoms and which is liquid at room temperatures, is used as the inert diluent or solvent » it is preferred that aas inert diluent has a boiling point above about 110 ° C, and preferably about 130 to 200 ⁰ C. Examples of such compounds are ethyl benzene, methyl benzene, and the ethyl ethylbenzenes, with ethylbenzene being particularly preferred. Ethylbenzene is referred to below as the preferred diluent »

The procedure can be briefly described as encompassing the following major steps. The filling mixture, which comprises ethylbenzene, styrene, the linear polybutadiene and the additives, is mixed in one or more containers where the rubber is dissolved. Anscriliessend the Ge is heated mixed with agitation in one or more containers and the polymerization at the catalytic or thermal initiation to a certain point executed In this be wegten or first Polyaierisationsstufe the rubbery material is also precipitated and Nimat certain critical properties of _e In the following In the second or second polymerization stage, the partially polymerized mixture is further polymerized without vigorous agitation.

the use of supplied energy is sufficient for the movement:

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of the polymerizing mixture. In second or, stationary-stage of the process- is the polymerization The mixture of polymerized material and diluent (ethylbenzene) is described in the following ■ Process stages subject to conditions where the diluent and unrelated or volatile constituents removed. Eventually, that of volatile Freed polymer melts, extruded or through some other means in their final physical Pormen converted.

While the basic procedural stages are described above have been, it is understood that such procedural steps can be carried out continuously or in batches or any of the above steps or a combination of the above steps can be carried out continuously while the remainder Stages can be executed character by character »

The amount of the inert diluent to be used is sufficient from 3 to 30% by weight, based on the total weight of the reaction mixture, the weight of the diluent excluded. For the most favorable conditions there will be no less than about 5i (preferably for batches with a low Jlautsch.uk content, e.g. initbelsciilag-resistant polystyrenes) and not more than about 2% (preferably for batches with a high chewing glucose content, e.g. Graiidmischun. ^ skonzeatrate) used. If less than about 3 to 5 Gew? a are added, then results from the Addition only a slight improvement. In some cases the diluent acts as a mild chain transfer agent "

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When carrying out the method, a mixture of about 65 to 97% by weight of the vinylaromatic component, about 3 to 35% by weight of the linear polybutadiene with a cis-1,4 content of at least 30%, the diluent is excluded, and an amount of ethyl benzene comprising 3 to 30% of the total weight of the reaction mixture are mixed together to form a solution. If necessary, a small amount of heat can be applied at this time to hasten the complete dissolution of the components. Then some or all of the additives to be introduced can be added to this mixture.These can be additives, initiators, lubricants, antioxidants or other stabilizers, and any other substances known in the art to be useful in such polymerization reactions in order to improve the oil properties to improve the finished product. The polymerization is initiated by heating the mixture to 60 to 140 ° with adequate agitation (peroxide introduction at the lower temperatures), preferably in a container or in containers (prepolymer (s)} from the one in which the polymerization is to take place heren ^ is completed raden are separated * J? ÜR the mixtures for the process according to the invention into consideration, to be achieved in the prepolymerizer temperatures of at least 60 ⁰ G "at this stage polymerization takes place, and preferably, a conversion level of the monomer (s) reaches between about 10 and 45 percent of the total reactants. Agitation by agitation should be provided in the prepolymerizer to achieve the preferred particle size of the rubber. It must be cooled somehow because the

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■ polymerization is an exothermic reaction and if that does not happen, to hot spots and burnout temperatures may develop. Uncontrolled temperatures at this stage of the process can lead to the formation of product with undesirable molecular weight distribution and / or undesirable gel structure, such as highly crosslinked materials.

The prepolymerized mixture is next in a second Polyuierizer passed, in which the .Polymerization im essential is accomplished »in this second polymerizer the temperatures are increased to between about 150 and 210 C. and they are critically monitored «. It is important to "polish" so as far as possible to the top end, preferably up to about 90 to 10C $> Conversion of the added or existing polymerizable material «Der second polymerization tank (or tanks) is with one more or less common, but carefully worked out v / arm transfer device provided to the inner To control temperatures ο if desired, can further polymerisation stages can also be used,

When the reaction reaches the desired level of completion the mixture is subjected to an evaporation step in order to the ethylbenzene and any other volatile present Substances, including possibly unreacted styrene or other vinyl aromatic compounds, must be removed. The hot polymer is then a 3t_-angpreß- or other Finished to the final resin product to manufacture «

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The experimentelle- observation shows that for specific reactive mixtures, d _e h .. a selected weight percent genalt the polymerizable monovinyl aromatic compound, the linear -Polybutadiens, the diluent and the verscniedenartigen additives which at or close to the initiation of the reaction in the Polymerization system are introduced, and for special pre-polymerization conditions, - there are certain critical time-temperature cycles which result in the best properties of the resin and thus the most satisfactory polymerization. It has been found, for example, that such a set of critical conditions for the second stage of the polymerization reaction, an approximately 8 to 18 hours' temperature cycle ( "cheraiische .Polymerisation) is that from 2 to 7 do £>" s at etv / a 100 to IA-O ⁰ C, followed by a allmähxichen increase aif a ündtemperacur at the end of 8 to 18 Stunienperiode of about 150 to 220 ⁰ G, composed "There we d preferable o.a3 one, but the temperature de * Chemical solire not drop below about 110 C after the initial Erwärmun _o spe Riode before completion of the R-jantion to veraeiden to the formation of polymer with undesirable tr Ia oils ocular weight distribution .

It is possible to carry out the process of the invention without an initiator, and preferably no initiator is added to the polymerization system. However, if desired, a relatively small amount, d _o h <, etv / a 0.02 to Oy ^ fooxs to a maximum of 1% based on the monomeric material of a compound of the free radical generating type,

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. Suitable are such as an organic "peroxide compound used peroxide initiators are, for example benzoyl peroxide, lauroyl peroxide, t-butyl peroxide, t-butyl-peroxydbenaoat, t- butyl hydroperoxide, Diacetylperoxyd, Diäthylperoxydcarbonat, Giimenhydroperoxyd, Cumylperoxyd u _e like.

In a more specific embodiment of the method according to the invention werlen et, .a 94 to j2 wt% styrene and about 6 to 8 wt% _? ; Excluding the diluent, a synthetic linear x-olybutadiene rubber, which has 30 to 98% polymer content of the cis-1,4-configuration, is combined into a dissolving container with about 10 by 15% by weight, based on the total weight of the charging vessel B. iithylbenzene added is stirred in order to ensure that these substances form a solution. The solution obtained is then transferred to a second container and additives are introduced into it. These additives comprise about 0.5 to 3% by weight of an inert i.iineralol, about 0.05 to 1% by weight of an antioxidant such as trisnonylphenyl phosphite, and about 0.02 to 0.08% t-dodecyl mercaptan.

The mixture is next transferred to a prepolymerizer which is agitated and which has an agitator of the polishing type. Both the supply and guidance of heat should also be provided in the prepolymerization tank by a circulating heat exchange medium. It's a fast but controlled heating desired, but the Realctortemperaturen should not exceed 130 ⁰ G in this reactor, let us preferably they should when the reaction was not

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fall below 10O ⁰ G. The batch is left in the prepolymerizer until about 15 to 40% conversion of the monomer. The reaction product obtained is transferred to a second polymerization vessel, where the polymerization is essentially completed in bulk. If desired, a filter stage will be interposed. -During the transfer should the temperature of the mixture is preferably not less than 100 G ⁰ let fall, otherwise undesirable results can be obtained.

The non-agitated polymerizer (or polymerizers) has high-capacity heat dissipation means and heat supply. The temperature is indicated as above - and in accordance with a specific Time-temperature cycle controlled when the polymerisation is run in batch operation, or alternatively, a number of reactors are operated in continuous operation Used temperatures which are adjusted so that the polymer mixture is exposed to the above time-temperature cycle.

It is preferred to strictly exclude air during both the prepolymerization and the polymerization stage, and indeed at the specified time when the polymer is in the dissolved and / or molten state. When exposed to air it tends to cause the formation of products which contain weak bonds which are unstable and which lead to undesirable properties, including odor and discoloration. The exclusion of air is done by replacing it with an inert gas and all

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■ Verifying units covered with inert gas or cleaned will. These two polymerization stages are approximately atmospheric pressure or which can run at superatmospheric Press to be executed. In any case, the polymerization is expediently carried out under a pressure which is sufficient Loss of monomers, ethylbenzene or any other the other substances by evaporation from the polymerization mixture to prevent at the reaction temperatures *

After completion of the polymerization, the mixture can, if desired, in a * Storage "or intermediate container are passed, or it may be unmitöelbar transferred to a degassing * This system consists of a heat exchanger (if any), where the melting temperature is increased to 140 to 240 ⁰ C, the this is followed by an evaporation zone where the low-boiling components evaporate, and finally from a suitable container for the separation of the vapors from the polymer melt * The degassing can be improved by using lower than atmospheric pressures, such as 5 to 150 mm Hg abs applies «The unreacted monomeric material, e.g. Styrene and ethylbenzene, which is recovered during the degassing, can either be returned to the dissolving tank or to the prepolymerization reactor. If necessary, these substances can be purified by conventional methods before being returned. The melted product is finally passed through an extruder and obtained as a finished resin within a wide temperature range

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high impact strength, excellent melt flow properties and gure has tensile and elongation properties in addition to improved surface properties,

jjJin another polymerization method to that described above is closely related, is the so-called mass-Verr'anren. The latter differs from the mass-solvent method in that no inert diluent is required and the ent; gas ongs stage can possibly be omitted The rules below show how to apply this Procedural failures.

The invention will now be explained in more detail on the basis of yet another usable process, i.e. a mass-overtaking process, which consists in adding a linear polybutadiene rubber with an ice-1,4 content of at least 30% Styrene is added in a prepolymerization tank equipped with a rinder. The linear polybutadiene rubber is preferably finely ground and is used in a narrow range ranging from about 4 to 15 weight percent based on the total weight of the styrene. It is also possible to ernaltenen solution of styrene and linear polybutadiene chain regulators, Antioxydan zien, mn lubricants and inert fillers are added to the above-threading th ^m close "

! laughs at the dissolution of the linear olybutadiene in styrene the prepolymerization in bulk and thorough agitation under " Use of a peroxydin initiator of the oil-soluble type or thermally initiated and the prepolymerization is also

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as in the procedure in. Hasse öler mass solvent. The copolymerization continues until 15 to 3% the preferred Ausl'ühruttöSf orm - the monomers in the Mixture that are polymerized and the rubber an average 'Particle size of. about 0.5 to 4 microns. The prepolymerization step generally takes about 2 to 4 hours, if you want to be sure that all rubber has come out of solution is. # if an oxygen initiator is used, such as BenzoyIp ^ roxyd, lauroyl peroxide, tertiary butyl perbenzoate, He becomes t-butyl peroxide, cyclohexanone peroxide, etc. in amounts of 0.05 to 0.2, preferably 0.5 to 0.15 g based on the mixture, ends / ends.

Completion of the pre-polymerization stage up to outer ge iiten Umvandluiig becomes aemic in an aqueous system suspended, which contains suspension stabilizers, and the polymerization continued to make grains of high impact strength Form material. It becomes an additional initiator to the Suspension added to the polymerization essentially to make completely. It is preferable to use thermal induction in the prepolymerization stage, then an initiator just prior to the suspension polymerization stage to be added * It is possible, however, in the prepolymerization stage Use peroxide initiation or two initially To include initiators in the pre-polymerization stages, such as a low temperature initiator for the pre ^. olymerisation and a high temperature initiator for the following suspension stage. A suitable initiator to be used during suspension polymerization can be used is an organic

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Peroxide, such as benzoyl peroxide, "Ca .royl peroxide, lauryl peroxide, t-butyl perbenzoate, .t-butyl peroxide, cyclohexanone peroxide and Their Mixtures “It usually becomes an initiator for suspension polymerization needed to shorten the entire time-temperature cycle of the polymerization, but needs in in some cases no initiator to be used.

The amount of initiator used for the suspension stage is based on the weight of the prepolymer and is at about 0.05 to 0.3 wt% if a particular one is used alone, or at 0.1 to 0.4 wt% if a combination is used. Preferred amounts are about 0.1 to 0.2% by weight for a single initiator and 0.075 to 0.15 wt% for each a combination »*

Ss can be desired after completion of the prepolymerization step if other additives such as chain transfer agents, lubricants sth. and further amounts of monomers can be added.

The prepolymer is added before or after the addition of the initiator for the suspension stage in an aqueous solution which contains a suspending agent, and the polymerization continued with the time-partial-temperature cycles indicated below until the monomer is essentially completely or completely granulated Balls of uniform size is polymerized. It can sus pendants such as carboxymethyl cellulose, polyvinyl alcohol, methyl cellulose, sulfonated polystyrenes, polyglyca & ether etc. be used.

An excellent suspending agent is a water-soluble,

High viscosity michtionic colloid in an aqueous one

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Solution. Hydroxyethyl cellulose is of particular interest because it provides optimal polymerisation results. The use of this suspending agent leads to no agglomeration of the polymer granules, minimal water entrapment in the granules and to granules with a narrow size distribution. Hydroxyäthylcellulooe with a viscosity in a l ^ oi ^ en aqueous solution at 25 ⁰ C of 750-10 OuO cps. (Brookfield viscometer) is appropriate ^"ü edoch is a preferred Visicositätsbereich for l ^ aqueous solution of hydroxyethyl 1500-3500 cps. at 25 ° C. The hydroxyethyl cellulose, preferred according to the invention, is readily available commercially and is soluble in hot or cold water.

The amount of hydroxyethyl cellulose used is about 0.025 up to 1.5% by weight and preferably 0.050 to 0.25% by weight, based on on the water. There will be any dissolved oxygen or oxygen in the atmosphere immediately above the suspension displaced by nitrogen.

The prepolymer is preferably placed in the vicinity of the impeller blades or scoops are added to the suspension to prevent it from forming and to facilitate distribution of the polymer grains. The prepoly msr is added in such an amount that the ratio of prepolymer to water is generally about 1: 2 to 3: 2, with the best results with a water ratio of 3; 4 · up to 1: 1 can be achieved ·.

The temperature of the suspension is gradually increased from the example as Raumtemparatur or high, such as up to 150 ⁰ C increased 90 ° C until up increases to about 135 ⁰ C and can, under appropriate conditions, followed by non-agglomerated, uniformly sized

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The most suitable time-temperature cycle for completing the present polymerization process after transferring the bulk prepolymer into the aqueous system is generally about 4 to 10 hours from 60 to 145 ° receive 0 · ils v / ground excellent SrgeDnisse when the Sus board 2 to 4 hours at a temperature of 100-115 ⁰ C, then for 1 to 2 hours at 115 to 125 ° G and seihließlich 1 to 2 Stunaen at 125 to 145 ° C is held.

The essentially completely iiolynurized polymer granules, which have been produced in accordance with the method described here, are separated from the suspension water by any of the customary methods such as sieving, sedimentation or centrifugation, dried, extruded, pelletized and packaged. . - .. " _:

For the following work, this will be done in each of the below Examples of applied methods explained in more detail.

It was finely ground linear polybutadiene in a monomer mixture dissolved by styrene. The monomer solution was placed in a container equipped with a stirrer and while the Solution was stirred, initiator (if one was used will) and additives such as chain transfer agents, antioxidants and lubricants added. The flask and its contents were purged thoroughly with nitrogen and a nitrogen blanket maintained above the solution.

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The moving 'solution and das'Monomer was partially polymerized in the Polymerisationstemperätur how ⁱ et «a..l2o Q under thermal initiation, heated until the liautsciiuktöilciien an average size of 1 to 4 microns had. An aqueous suspension bath would be produced in the hydroxyl acid cellulose, which in an aqueous solution at 25 ° C. had a viscosity of about 1500 to 2500 cps. (Brookfield Viscometer) was dissolved in the suspension reactor, which was provided with a drill and a heat transfer device. The prepolymer, after initiator addition, was added to the aqueous suspension at a moderate rate while the suspension was kept in constant motion. cm nitrogen - pressurized «Me polymerisation, was carried out under Be. Movement at a temperature cycle of 3 hours at 115 ° C. for one hour at 125 ° C. and one hour at 15 ° C. continued after completion of the polymerization, the mixture was cooled, the reactor opened and the contents filtered to reduce the temperature Isolate grains. The grains were washed with water and dried in vacuum oven at S5 C ₀ dried on injection-molded samples were measured for physical properties. A series of comparative runs representing the three polymerization processes described above were carried out with the results reported in the following table. Is the viscosity and shear conditions in the prepolymerization stage and this stage up to one

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Precisely stated that ... the rubber separated completely from the solution and the chewing particles had an average particle size of 0.2 to 6 microns. The Polymerisationsbedinguneen were chosen depending on the particular-applied process so that the final polymer has a gel content below 30% and a ^ uelluiigsindex higher than 5 had contains _β The gel content of se llagfesten polystyrene, which is linear polybutadiene as the kautscnukartige component is determined by immersing the polymer in methyl ethyl ketone and centrifuging it to obtain the insoluble gel portion, "after the swollen egg is dried in an oven, the gel content can be determined by weighing. The swelling index is then determined as follows calculated:

■ each of the swollen gel in grams

For polystyrene modified with linear polybutadiene, the gel content (with 3 to 1Jjb rubber in aem polymer) should preferably range from 5 to 1K)% by weight of the polymer, while the ue j. The swelling index (measured in methyl ethyl ketone) should preferably range from 8 to 15 (if it is determined in toluene, the swelling index is higher, for example for the preferred values given above - 10 to 20) "

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¹ f method, mass mass mass mass mass mass mass ^ e Mcs.se mass mass mass Lasse

r . . '■. . ■ '..'. ■■■ Sol. Sol. · Sol. Sol. Sol. Sol. Susd. S-aso. Susd. öusp.

{■; 'Rubber type,, ■ SBR F ^VJ "-' SBR P 3BR P - SBR P SBR ..? P? "'' Rubber $ 8 7 .. ■ 8 ο, 7 7 S 7 f 5 6 3

^J Melt flow ^ ² ^ b.190 ⁰ C 7.4 7.7 2.6 2.8 1.3 2.0 5-7 5-Ό G.25 10.2 1.0 1.4

O Izod impact strength P '<23 ⁰ ) 0.5-l 1-3 1.7 2.7 1-5 2.0 1.2 1.8 lo 1.8 2, b 0.9

^ Yield point (tensile «Tield) 4300 - 3330 30 & 0 4bl0 4220 3360 3280 2540 3000 3o60 6o2C

Breaking stress (tensile #fail) - - - 3420 276Ο 4bpO 4320 2 <> jQ 3300 33IO 2010 4020 5720

Q elongation ^^ 30.0 24.6 43.0 30.ο 34.4 35.2 25.L 44.> · - 43.2 34.4 -

^ ¥ heat deflection ^^ 8c - - 82.8 84.0 84.5 i ^ OO - - - 76. 9 οβ.Ο &i> .o

«» Flexural strength ■ - - 4220 5200 5860 - - - - - -> 3C0

r *. .Hardiiess, Bockwell ΐΛ '- - 55 64 Co 71-5 -. - - 59 73 90

** · (l) Linear polybutadiene with a cis-l _i 4 content of 35) j (Mooney viscosity = 55).

, (2) gramn / 10 minutes; ASTM D-1238 -57T (InstrUiiientbedingungen: 190 ⁰ C and a load of 5,000

(3) Ft.lb/inch notch: ASTM D-256-56

(4) The strength properties, as they are given here, measure the ultimate elongation in the form more plastic, fabrics using the gauge length disk on an Instron Tensile Tester as eii Display of elongation up to the break point. Test samples were produced according to D-638.

(5) ASTM D-648-56

(6) ASTM D-7S5

The introductory values show that the new rubber modified monovinylaromatic graft polymers easily by either the bulk, bulk-solvent or bulk suspension polymerization process ears can be produced. The «Verte also clearly show the unexpected superiority of linear polybutadiene as the rubber component compared to a common rubber such as 8BR, (an in emulsion polymerized copolymer of about 25% styrene and 75% butadiene) «

Experiments A and B were made according to the mass method »Bei With similar melt flow properties, significantly higher impact strength was obtained even when the linear poly was butadiene in a smaller amount than the SBR was used.,

Experiments 0 to H show comparisons between the two different types of rubber in the bulk-solvent polymerization process. In experiments G and D, polymers with a medium-high melt flow were produced with 8% rubber. It must be emphasized that in Experiment D the use of linear polybutadiene rubber resulted in extraordinarily high impact strength and also excellent heat resistance, and improved hardness, to an excellent level. indicate the weight of the physical properties. In attempt. E and J , heat-resistant, impact-resistant polystyrene was made with ^ * 7fr rubber. Experiment F, which was made with the linear ^ f polybutadiene, resulted in a completely unique- ^

gen combination, of excellent melt flow, Izod impact <o

Toughness, heat deflection and hardness, it became an easy flow ⁰

of the resin in trial. G and H made. The latter attempt.

¹ BADORiGINAL -27 ^

made with a small amount of linear χolybutadiene had unusually high impact strength for a resin with such a high melt flow

The suspension polymerization process is shown in Trials I to L. As shown in Trial I, a high percentage of SBR resulted in acceptable impact strength but decidedly inferior melt flow _β. For comparison, <Wer ·. ■:;.:, ■ J and K, die were made with only 6% linear polybutadiene, a well-balanced combination of either good impact strength with extremely high melt flow (for high-speed compression processes) or high-melt flow in the extrusion area in connection with extremely high impact strength, hardness and good heat resistance

Experiment L shows that a medium-impact polystyrene having been drawing animal heat resistance with a very small Kautschukkonzencra1; ion of 3: J, which is much clotting ^ he has been usually used for such iii _u characteris tics amount of SBR, Herge q represents may be.

Poljrjaere LIischun, s which are provided by the above methods forth can find manifold uses and jexiigen which have high impact strength have, together with AEEN higher values for the melt flow, are particularly useful comparatively heavy in the formation, semi-rigid films, for example, directly as flat paneling, etc., or to form food containers, drinking cups for hot liquids, devices for handling food, charging

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909884 / 16U bath

ORIGINAL

boxes, housings used for radio and television receivers can be, as well as pressed and covered with foil parts for refrigerators. The high impact strengths of the resins guarantee that they will be free from cracking or splintering under any of the ordinary stresses or impacts, they in use even under extreme temperature conditions could suffer. These resins can also be subjected to compression molding and injection molding for various articles will.

As also stated above, a considerable number of advantages are achieved by using linear polybutadiene with a cis-1,4 content of at least 30%. It has been found that the graft copolymers have high impact strength at low temperatures compared to products which are obtained when SBR or other conventional rubbery substances are used, also advantageously, the high melt flows together with the high impact Zähigkeite are Furthermore, the resin products are characterized by aer invention through excellent üVärmebiegung, tensile elongation, transparency and other properties Aeus _o the balanced properties The chewing-modified resins according to the invention lead to numerous technical applications which were not possible with the previously available graft copolymer products.

The outstanding properties that were in linear PoIybutadienkautsch.uk modified monovinylaromatic graft copolymers according to the invention found, occur more in the following discussion of their properties revealed _β

■ '■ §09.884 / 1614 - 29 -

The Izod notched impact strength (i / 8 "in.Stab), determined according to AuTM" D-256-56 is at least 1.5 ft. Lb / in. with a general • Range from approximately 1.5 to 3.0 ft "lb / in. for a high impact Approach. The preferred value is about 1.5 to 2.2 ft » .lb / in. (Score)

The melt flow determined) -57 ^ -12p8 at 19O ⁰ C ranges from about 0.5 to 12 grams per 10 minutes after AoTM J. For certain resin grades, a melt flow value of about 3 to 7 is preferred, while for other or heat-resistant resin grades a melt flow of about 1.5 to 3 »0 is desired. When using the linear polybutadiene with a cis-1,4 content iefc of at least 30%, the coveted impact strength and melt flow properties can be achieved even with low rubber concentrations. It will be understood, however, that another advantage obtained with the linear polybutadiene arises from the fact that one can use large concentrations of the rubber to make masterbatches which can be easily used for blending

When producing the graft polymers according to the invention, it was found that the reaction mixture which contained the linear polybutadiene was much less viscous than when graft polymers are produced using conventional (SBR) rubbers. This feature permits are or erleichterij the necessary in the polymerization degree of movement, seibst _r wenn.hohe percentages of rubber used · It was also the heat transfer in both polymerization -

098 04/1614 BATH ⁰ ^

stages facilitated due to the lower viscosity of the linear poly butadiene-containing mixture. For example, in prepolymers made with 8fo SBR and linear polybutadiene having a total solids content of about 32%, the Brookfield viscosity at 75 ° C was about 1380 cps for the prepolymer containing SBR, while it was only 6,800 cps for the Prepolymer with linear polybutadiene was «

As previously discussed, a high degree of grafting is also coupled with the desired degree of crosslinking with linear Polybutadiene achieved as the rubber component »This is determined by the gel content and the ullage index. With a salary of linear polybutadiene on the order of 8% by weight, the gel content is below 30 / j and generally in the range from about 5 to 20 years of age The source index is over 5 and in general about 10 to 20 (if it is determined in toluene) · This Values vary depending on the amount used Rubber*

A very important property of the new graft copolymers according to the invention is the low-temperature impact strength or the temperature at which the resins become brittle. When play has been indicated that linear polybutadiene rubber with a high cis-1,4-Gahalt such a low Sprädigkeitstemperatur as has -85 ⁰ C. In contrast, it has been stated that SBB under the same conditions has a temperature of -50 ⁰ O, wherein these temperatures show breakage. Consequently, it was found that resins made from linear polybutadiene had impact strengths ^{below -20 0 C,}

. - 31 -

9098 84 / 16U

- - ■ ORIGINAL BATHROOM

which were 50 to 100% higher than resins made from SBR were o

The heat bending 3 is inherent in the graft copolymers

Λ

according to the invention are also excellent. In general, the V / G ärmebiegung than 85 and there may be shallow by Ausfahrung graft copolymers of the invention are provided here, the preferred heat deflection values in the range of about 88 to 90 ⁰ C have. Previously, high heat deflection values were obtained at the expense of significantly lowering impact and melt flow values. In the present invention, all three properties can be achieved.

There are also excellent surface and optical properties in the graft copolymers according to the invention. It has been found that the Rockwell L-hardness in the range of about 50 to ^ O, and preferably about 65 to 75 at a high impact strength liegte The transparency of the graft copolymer, which is made with a linear polybutadiene is also superior to that associated with conventional liautschuken such as SBR is obtained. It has also been found that gloss can be easily controlled to give either a predetermined gloss or dullness "

The graft copolymers, ax according to the invention Herge provides have tensile elongation values that are also greater are than with graft copolymers, which are made from conventional Eaut-

. : - 32 - ■

90988 4/1 6U ORIGINAL BATHROOM

15952G9

r 52 -

schuke.n, like SBR, manufactured sincU Die, · '.u gdetuning at break, which was measured according to AoTM D-6J8-44T, was within the range of about 20 to 50% and was preferably about 30 to 40% o In contrast to known products, both V / poor bending and tensile elongation showed high values. (Up to now, increases in tensile elongation have been obtained at the cost of low bending values and surface hardness

Finally, the tensile strength and flexural strength were the Resin products according to the invention are comparable with the values advertise those found in first-class products currently on the market «

While special embodiments of the invention are shown above it is to be understood that the invention will be apparent Can be subjected to variations and modifications, without deviating from the concept of the invention.

Patent claims:

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Claims (1)

". Claims: 1. Impact-resistant resinous graft copolymer having well-balanced physical ü! I _L jun shank s, characterized in that it comprises x ³ olymerisationsprodukt from 65 to 97 wt% of a mbnovinylaromatischen compound and 3 to 35 wt% of a linear polybutadienes having a cis-l, 4 content of at least 3o? O and a Mooney viscosity of about 30 o to 90 is » ■ 2. Graft copolymer according to Claim 1, characterized in that the monovinylaromatic compound is selected from that of styrene Alkyl derivatives of styrene, halogen derivatives of styrene and their mixtures standing group is selected » 3. Graft copolymer according to claim 1, characterized in that the linear polybutadiene has a cis-1,4 content in the range from about 30 to 38fc . 4c graft copolymer according to claim 3 »marked thereby net that the linear polybutadiene has a cis-1,4-Ga content of about 35 to 60%. 5 »Graft copolymer according to claim 1, characterized in that that the linear polybutadiene is an average Particle size less than about 6 microns, preferably 0.2 up to 6 microns, has - 34 ■ -.-. ' 909884 / 16U ^^^ \ 6J Verfanrai for producing an impact-resistant resinous graft copolymers, characterized in that about 65 to 97 wt% of a monoviny! Aromatic compound and from about 3 to 35 Gevf / o linear polybutadiene having a cis-1,4 content of at least 3Q / o and an Ivlooney viscosity of about 30 to 90 can be polymerized o 7o method according to claim 6, characterized in that about 65 to 97% by weight of styrene and about 3 to 25% by weight of linear polybuta Serve with a cis-1,4 salary of at least £ 30> and a Mooney viscosity of 40 to 60 can be polymerized o 8e method according to claim 6 or 7 »characterized in that that a linear polybutadiene with a cis-1,4 content of about 30 to 985S is used » 9 · Method according to claim 7 or 8, characterized that alpha-methylstyrene in a small amount for styrene is used. 10. The method according to claim 6-9, characterized in that a linear polybutadiene with an average particle size of about 0.2 to 6 microns is used / is / 909884/1614