DE2713732A1 - TRANSPARENT POLYMER MATERIALS - Google Patents

Description

CHpUng. P. WIRTH Dr. V. SCH MIED-KOWARZI K DlpUne. G. DANNENBERG Dr. P. WEINHOLD Dr. D. GUDEL

335024 StEGFRIEDSTRASSE β

TELEPHONE: COM) _{e000 MQNCHEN AQ}

C-9634-G

UNION CARBIDE CORPORATION

270 Park Avenue

New York, N.Y. 10017 / USA

Transparent polymer materials .

709842/0735

The present invention relates to polymer alloys " (compatible mixtures of polymers). It is known that mixtures of polystyrene and styrene-acrylonitrile copolymers are incompatible and opaque. It is also known that even styrene-acrylonitrile copolymers whose acrylonitrile content is more than 4% by weight are mutually incompatible A composite material comprising both resins in a compatible mixture and having the properties of both resins would be a significant advance.

In this connection, reference is made to U.S. Patent Nos. 3,448,175, 3,681,475 and 3,678,133, Belgian Patent No. 775,373 and Japanese Patent No. 4,709,993 referenced.

The object of the present invention is to provide a transparent polymeric material and alloys with this which have similar mechanical properties as the individual polymeric constituents, and in particular to provide a transparent, compatible polymer alloy which contains polystyrene and a styrene-acrylonitrile blend polymer .

This object is achieved by the present invention.

The transparent polymer material according to the invention comprises a portion of polystyrene, a non-uniform polymer portion of styrene and acrylonitrile and a portion of a styrene-acrylonitrile mixed polymer. The transparent polymer material has mechanical and other properties which correspond to the properties of the component mentioned in the first and third places. The non-uniform polymer fraction is produced by a process that comprises the following steps: supplying at least one primary polymerizable 3eschangungszusanmensanmensification from the group of monomers: styrene, acrylonitrile and
70984 2/07 3 5 = "tail portion"

= "intermediate portion"

- ir-

a mixture of styrene and acrylonitrile, from at least one primary feed source into a polymerization zone, wherein the primary polymerizable feed composition in terms of the proportion of polymerizable therein contained Reactants varied continuously during the continuous feed; simultaneous provision of at least a secondary feed source in addition to the primary feed source to reduce the content of the polymerizable Reactants in the primary polymerizable feed composition continuously changing from the primary feed source; and continuous polymerizing of the primary polymerizable feed composition introduced into the polymerization zone until the desired one Polymerization is achieved, this being carried out under conditions depleted of monomers. The primary polymerizable feed composition is different from the secondary polymerizable feed composition.

In a monomer-depleted system which means rapid polymerization, the monomers become practical reacted immediately after they have been introduced into the polymerization zone. In a system based on monomers the polymer that differs to any particular one! Time period has been established in the composition of the polymer produced in previous or following periods.

According to the invention, a transparent, compatible polymer alloy of polystyrene and a styrene-acrylonitrile mixed polymer is obtained. This transparency and better clarity is evident on a better tolerability and / or one better gradients compared to a physical blend of polystyrene and a styrene-acrylonitrile copolymer traced back. ■ an achieves the best degree of transparency when the transparent polymer material is from around 30% by weight of the non-uniform polymeric material.

"starved conditioSlD ^ 8 k 2 I 0 7 3 5

With the transparent polymeric material according to the invention, polymer alloys with a very high transparency are obtained, when mixed with polystyrene, a styrene-acrylonitrile copolymer, or any of these, and regardless of the manufacturing process.

An improved method of making the improved, non-uniform transparent material of the present invention Polymeric material is disclosed in U.S. Patent No. 3,804 described. The method in which there is no change in the composition of the reaction vessel charge is preferred at the beginning and at the end of the reaction, as described in Example 1. This procedure enables the Production of copolymers with very different compositions on easily controllable and reproducible Way.

The principle according to the invention can also be used for many other polymerization processes be applied. For example, polymerization in solution can be based on free radicals or bulk polymerization can be used; an anionic "living-type" chain growth or cationic Procedures are applied. In the case of the anionic "livingtype" polymerisation The change in the composition of the feed is reflected in each polymer chain. Except Acrylonitrile, other monomers can also be present in the material - including vinyl chloride, acrylate esters, etc. These monomers can be part of the first and third part, the non-uniform polymer part (des second part) or of all of these parts. The concept of compatibility described here is new and can be applied to various addition and condensation polymers.

Fig. 1 is a schematic representation of a typical device arrangement for the method according to the invention.

see last paragraph on page 2

709842/0735

The method used is the improved method of U.S. Patent No. 3,804,881, which allows interpolymerization reactions with excellent control Distribution of the monomers achieved. A typical apparatus used in this improved method of making the non-uniform proportion of the copolymers can be used, is shown in Figure 1 schematically. The polymerization is essentially carried out by adding the monomer A is pumped from tank I into the reaction vessel and at the same time the monomer B is pumped from tank II into tank I. this leads to to an accumulation of monomer B both in tank I and in the charge of the reaction vessel. Assuming that the polymerization takes place at the same rate as the monomer feed, the composition of the polymer formed at a certain point in time corresponds the composition of the charge at the same time. This leads to excellent compositional control and compositional profile in the obtained one Polymer.

In a typical free radical polymerization in which the composition of the feed If 100 % of monomer A is changed to 100 % of monomer B, the resulting polymer mixture would be, for example, as follows:

AAAAA ... A at 100 % of the monomer A

AABAB ... A

BBABA ... B up to BBBBB ... B at 100 % of the monomer B.

By varying the composition and the amount of monomers In tank I and tank II as well as the pumping speeds it is ■ possible to obtain a practically unlimited number of non-uniform proportions.

709842/0735

The non-uniform polymer portion of the polymerization scheme of the present invention must be made under "monomer depleted conditions" - this is essential. If these conditions are maintained, then the composition of the non-uniform polymer portion of the polymer molecule formed at any given point in time will correspond to the composition of the feed. The monomer depleted conditions are best achieved in a typical emulsion system using a free radical initiator. The preferred initiating agent is potassium persulfate (K ₂ S ₂ Oq); and the reaction is preferably carried out at about 50-80 ° C. In general, a yield of about 95 % polymer (based on the added monomers) is obtained.

The final non-uniform interpolymer is a blend of chains with constantly changing composition, starting with pure polystyrene up to a pure styrene-acrylonitrile mixed polymer. The result is a compatible material that contains chains of the two components. It is transparent when it is compression molded (mixtures of polystyrene and a styrene-acrylonitrile interpolymer, these are not), and it has mechanical properties within the desired intermediate range.

It is preferred that the non-uniform fraction make up about 20-40% by weight of the total molecule, with about 30% by weight aa are most preferred. However, amounts as little as about 10% by weight can be effectively used.

Another aspect of the present invention is the production and use of the mixed polymer which contains the non-uniform fraction.

709842/0735

An improved one is disclosed in U.S. Patent No. 3,804,881 Process for the production of non-uniform copolymers described, which essentially consists in that at least one primary polymerizable feed composition is introduced into a polymerization zone, the composition of the reactants in the primary polymerizable feed composition is continuously changing while at least one primary Polymerization feed composition in at least one primary feed source at least one different secondary polymerizable feed composition is added from at least one secondary feed source to the level of reactants of the primary polymerizable feed composition in the primary feed source to change continuously; and the primary polymerizable feed composition fed to the polymerization zone has been introduced, is polymerized.

In this process, styrene and acrylonitrile are used as the starting materials and a monomer depleted system is used. The following discussion of the improved method is general in terms of starting materials, as this procedure is also applied to other starting materials can be. Corresponding sections of U.S. Patent No. 3,804,881 are expressly incorporated herein by reference taken.

In this process, the concentrations of polymerizable Reactants in the primary polymerizable feed composition during the introduction of the primary polymerizable feed mixture into the polymer ion zone by simultaneously adding another, second polymerizable feed mixture to the primary polymerizable feed mixture is constantly changing. The essential feature of this improved method is in that a primary polymerizable feed mixture

709842/0735

is introduced from a primary feed source into the polymerization zone, while at the same time at least one secondary, another polymerizable feed composition from a secondary feed source to the primary polymerizable Feed composition in the primary feed source is introduced.

Any appropriately equipped reaction vessel suitable for the production of polymers can be used as the polymerization zone. The various types of reaction vessels and their suitability for special polymerization reactions are known to the person skilled in the art and need not be explained here. At least one primary feed source is connected to the polymerization reaction vessel. The term "primary feed source" refers to one or more tanks or sources of polymerizable reactants which are fed directly into the polymerization zone or reaction vessel; it can be, for example, a special mixer ("in-line mixer ¹ *)" or a tank. The primary feed source is equipped with an effective mixing device to ensure sufficient mixing of the contents. Each primary feed source is then at least one Secondary feed source connected. The term "secondary feed ^{source 11"} refers to one or more tanks or sources of polymerizable reactants which are fed into the primary feed sources. There can be one or more secondary feed sources, with either the feed from all secondary feed sources taking place directly into the primary feed source, or the secondary feed mixture can / passed from a secondary feed source into the next secondary feed source and thoroughly mixed therein until finally a last one secondary feed mixture from a final secondary feed source is passed directly into one or more primary feed sources. The speed of loading

I 709842/0735

"Inner tube mixer"

Sending from one feed source to another feed source or a tank - regardless of whether it is primary or secondary - can be varied as desired by the person skilled in the art, depending on the desired product. The improved method can be done in many different ways; in any event, however, there must be a polymerization zone or reaction vessel connected to at least one primary feed source or tank equipped with mixing devices, which in turn is connected to at least one secondary feed source or tank is connected, with - if there are several - the secondary feed mixture from either all secondary sources or tanks or only from some of them is fed directly into one or more primary feed sources or tanks, or the secondary mixture from one secondary tank to the next and then to the primary feed source or tank last will.

The primary polymerizable feed composition is the mix of respondents leading to any one is present in the primary feed source or tank at a certain point in time. This mix can be either just that contain polymerizable reactants or else Contain additives that have no adverse effect on the polymerizable reactants (e.g. diluents or solvents, dyes, dispersants or Enilsionsmittel, antioxidants, stabilizers, chain transfer agents, crosslinking agents, initiators ■ ittel, one of the components of a reduction-oxidation catalyst system and the like). The concentration of primary polymerizable feed composition is continuously changed by adding and mixing with a secondary polymerizable feed composition. By the term "concentration" is meant the level of each reactant in the polymerizable feed composition

709842/0735

meant. As can be seen from the present description, has the simultaneous supply of the primary polymerizable feed composition from the primary feed source into the polymerization zone and another secondary polymerizable feed composition from the secondary feed source to the primary feed source a constant change in the content or concentration of any in the primary polymerizable feed composition. the reaction participants present. This constant change The concentration can also occur in the secondary polymerizable feed compositions, if more than one of these is used and they are passed "in series" from one secondary source to the next before being incorporated into the primary polymerizable feed composition be directed.

The secondary polymerizable feed composition is the mixture of reactants present at any particular time in one or more of the secondary feed sources or tanks, and it may also contain the additives noted above for the primary polymerizable feed composition. (It should be remembered, however, that if one of the polymerizable feed mixtures contains one of the components of a redox catalyst system, the other of these mixtures must not contain the other component, otherwise polymerization will take place in the feed tanks before the polymerizable reactants enter the Polymerization zone have been introduced.)

The primary polymerizable feed composition can start with a single polymerizable reactant, or it can start with multiple polymerizable reactants; the same is true of the initial composition of the secondary polymerizable feed composition. However, if the primary polymerizable feed composition consists of a single reactant, then the secondary polymerizable

709842/0735

sizable feed composition not also consist solely of that same reactant; it can then be either a different single reactant or a mixture of several reactants, which can also include the reactant of the primary composition. Likewise, when the primary polymerizable feed composition is a mixture of multiple reactants, the secondary polymerizable feed composition cannot be the same mixture with the same concentrations of each reactant; it can either be a single reactant or a different mixture of reactants or else a mixture of the same reactants but with different initial concentrations. It is essential that the initial concentrations in the primary polymerizable feed composition and in the secondary polymerizable feed composition are always different, they are not identical in terms of the replenishment of the polymerizable reactants. I _

_Infolge the initial differences between the concentrations in the primary and secondary polymerizable feed compositions and the addition of the secondary polymerizable feed composition to the primary polyinerisier- cash feed composition with simultaneous retraction of the primary polymerizable feed composition in the polymerization zone is a permanent change in concentrations take place in the primary polymerizable feed composition. Thus, each portion of the primary polymerizable feed composition that enters the polymerization zone will always be different from the previous and subsequent portions. As a result , the composition of the polymer produced in the reaction vessel during the addition is also constantly changing, and it corresponds to the composition of the primary polymerizable feed composition which enters the polymerization zone. In the case of a rapid polymerization reaction (such as the so-called polymerization reaction "at bar ¹¹ ), in which the

709842/0735

Monomers are reacted practically immediately after they have entered the polymerization zone, one has a system that is referred to as a "monomer depleted system". (In other reactions one can use a so-called "monomers rich system ", i.e. a system in which there is some time lag between the introduction of the reactants into the polymerization zone and the practically complete one Polymerization of the reactants exists.) In a system depleted of monomers differs i.e. the polymer produced at a certain point in time in the component concentration of those polymers which are made before or after. (In the case of a system rich in monomers, on the other hand, the composition depends of the polymer formed at any given point in time on the concentration of each monomer in the polymerization zone and the respective reactivity of each monomer present in relation to the other monomers.) So there will be certain non-uniform polymer compositions made from polymer molecules, which have unlimited variations have the molecular structure. With the term "unlimited Variations of the Molecular Structures "is meant the mixture of the unlimited number of different polymers, which is produced by the improved process in the polymerization zone. The term "non-uniform" means that at any point during the polymerization reaction The polymer molecules formed are different from the polymer molecules formed at any other point in time.

The improved process can most easily be described in terms of a reaction in which a single primary Feed source, which initially has a single polymerizable Contains reactants, and a single secondary source of attention, which initially includes a single, contains other polymerizable reactants will. The one in the primary feed source or tank at all times during the process Contents are combined as the primary polymerizable charge

709842/0735

and the contents of the secondary feed source or tank are called the secondary polymerizable feed composition. The supply from the secondary feed source to the primary feed source is through suitable lines and pumps; the primary feed source is equipped with an effective agitator or mixer and from there it is fed into the polymerization zone. At the beginning of the polymerization reaction, the flow of the primary polymerizable feed composition from the primary feed source into the polymerization zone is started at a predetermined rate, and at the same time the flow of the secondary polymerizable feed composition from the secondary feed source into the primary feed source is started, the second flow rate being either the same or can be different from the flow rate from the primary feed source to the polymerization zone. As the secondary polymerizable feed composition enters the primary feed source , it is thoroughly mixed with its contents, resulting in a constant change in the concentrations in the primary polymerizable feed composition. This ever-changing primary polymerizable feed composition is introduced simultaneously and continuously into the polymerization zone and the polymer produced therein varies according to the level of reactants in the mixture in the polymerization zone. As previously mentioned, either one of the two feed sources, namely the primary and secondary feed sources, or both feed sources can contain more than one polymerizable reactant.

The possible variations in the arrangement of the primary and secondary feed sources are and should be numerous not all are described in detail here; it is easy for those skilled in the art to find a suitable shape or arrangement for achieving this of optimal working conditions or for the manufacture of product

^th 709842/0735

■ to develop it with certain desired properties. A simple arrangement using a single primary feed source and a single secondary feed source has been described in the preceding paragraph. For example, in a somewhat more complicated arrangement there could be a single primary feed source and multiple secondary feed sources; in these cases the feed from all of the secondary feed sources in parallel could be directly into the primary feed source, or it could come from some of the secondary feed sources in

. Series take place in other secondary 3 loading sources, in which case the supply from at least one secondary loading source finally takes place directly into the primary loading source. In other arrangements there can be multiple primary feed sources; in these cases the feed can be from a single secondary feed source into one or more of the primary feed sources, or there can be several secondary feed sources from which the feed is made in parallel directly into only one of the primary feed sources, or the feed can be from several secondary feed sources directly into more than one of the primary feed sources, or the secondary feed composition can be fed from all of the secondary feed sources in series into only one of the primary feed sources, or can be fed from multiple secondary feed sources in series into more than one primary feed source. If multiple secondary feed sources are used, they can be arranged in any desired combination; they can all be arranged in series, or some can be arranged in series while the others are arranged differently, or they can be fed directly into the primary feed source from all of the secondary feed sources. In all cases the primary polymerizable feed composition is introduced into the polymerization zone from the primary feed sources; the secondary polymerizable feed composition is made up of the secondary feed

709842/0735

swell directly into or over the primary feed source other secondary feed source qh) into the primary feed source before it finally reaches the polymerisation zone. During this carriage the Reactant from one feed source to the next finds a constant change in the concentrations of the The contents of the tank to which the polymerizable reactants are added and the contents of the tanks are added stirred to achieve efficient mixing of the contents. One can also vary the method in that one the primary polymerizable feed composition at certain times at the beginning, during, or towards the end of the reaction passes from the primary feed source into the polymerization zone without simultaneous for a period of time a secondary polymerization feed composition to the primary feed source or tank is directed. In addition, the flow rates between the feed tanks and the polymerization zone can be varied during the polymerization reaction they become deserted in a correspondingly different way. The polymerizable Reactants from multiple secondary feed sources

Via a mixer within "the supply line, which

serves as the primary feed source and wherein the primary polymerizable feed composition is prepared, respectively. From the mixer in the feed line becomes the primary polymerizable feed composition then passed directly into the polymerization zone.

In the improved process, non-uniform polymers are produced in a controlled manner. With the term "Non-uniform polymer" are polymer compositions meant that are prepared by reacting a polymerizable reactant mixture, which during the Duration of the polymerization in the concentrations is constantly changing. The polymer made by this process can have unexpected properties. With a certain one

709842/0735

Polymerization processes ("at bar") give polymer compositions of styrene and acrylonitrile, which have unexpectedly good clarity (i.e., they are clear or transparent).

The concentration of a particular polymerizable reactant, which is initially present in the primary polymerizable Beschickungszusainmensetzung or in the secondary polymerizable feed composition can be between about 0.01 and 100 wt -.%, Based on the total weight of polymerizable reactants initially present in the feed stream be . These concentrations can be varied by those skilled in the art in order to obtain the desired final concentrations of each reactant in the polymer or to obtain certain properties in the polymer. The flow rates from the secondary feed sources to the primary feed sources can also be varied by those skilled in the art and need not be specifically discussed here; however, they must be chosen so that a monomer-depleted system is obtained when a rapid polymerization process ("at bar") is carried out. The process uses the appropriate temperature and pressure conditions for the reactants used.

The polymerizable feed compositions can contain the usual amounts of dispersing aids, emulsifying agents, Colorants, activators, catalysts and others are conventional in polymerization reactions Contain additives used. All known dispersants can be used in the conventional concentrations e.g. hydroxyethyl cellulose, carboxymethyl cellulose, poly (vinyl alcohol), methyl cellulose, sulfated Cellulose and the like. Each of the known emulsifying agents can be used in a total concentration of preferably less than about 1 weight percent based on the total weight of the polymerizable reactants can be used.

709842/0735

Suitable emulsifying agents include soaps, sulfonated Alkylbenzenes, alkylphenoxyethylsulphonates, sodium laurylsulphonate, Salts of long-chain amines, salts of long-chain carboxylic or sulfonic acids, allylphenol ethoxylates, linear alcohol ethoxylates and other emulsifying agents.

The particular catalyst to be used depends on the polymerizable Respondents. In the system depleted in monomers ("at bar"), an initiating agent is used on the Used based on free radicals. The catalysts themselves are not the subject of the present invention, and the suitable catalyst is known to depend on the type of polymerization being carried out and the reactants used away. The catalysts are used in the conventional manner in the conventional concentrations. examples for Initiating agents based on free radicals are hydrogen peroxide, peracetic acid, tert-butyl hydroperoxide, Di-tert-butyl peroxide, dibenzoyl peroxide, benzoyl hydroperoxide, 2,4-dichlorobenzoyl peroxide, 2,5-dimethyl-2,5-bis (hydroperoxy) -hexane, Ferbenzoic acid, tert-butyl peroxypivalate, tert-butyl peracetate, Azo-bis-isobutyronitrile, ammonium persulfate, potassium persulfate, sodium persulfate, sodium perphosphate and the like.

The improved process can be used to carry out emulsion polymerization reactions, aqueous and non-aqueous dispersion polymerization reactions, suspension polymerization reactions, Solution polymerization reactions and bulk polymerization reactions are applied, the basic concept being is observed for these reactions, but the reaction is carried out according to the procedures described here. the Basic concepts for each procedure are so well known that they do not need to be described in detail here, and if they are with the teachings of the present invention are combined, they are to one skilled in the art of polymer manufacture fully understandable. The solid polymers can be recovered in a conventional manner.

709842/0735

The following test procedures were used:

ASTM-D 638-72 for elongation, tensile strength, and stiffness. ASTM-D 1822-68 for Izod impact strength. ASTM-D 648-72 for heat deformation. ASTM-D 746-73 for brittleness temperature.

In a preferred polymerization scheme, the apparatus of Figure 1 was used, as was all of the examples listed herein. Tank I, Tank II, and the reaction vessel were round bottom flasks. The reaction vessel was provided with a nitrogen gas inlet, a mechanical stirrer, a condenser, and a thermometer with a temperature control unit. The tanks were fitted with magnetic stirrers and nitrogen inlets. The monomers (styrene and acrylonitrile) were added to Tank I and Tank II; 1,000 ml of distilled and pre-boiled water, 1.8 g of an emulsifying agent and KpSpOg as initiating agent (0.4 g plus 0.2 g at the end of each hour of reaction time in the reaction vessel) were added at the beginning. The response was at 75. +. 1 ° C_ carried out. Nitrogen was passed through Tank I and Tank II and bubbled through the reaction mixtures. A micrometer pump was used to pump the monomers from Tank II into Tank I and from Tank I into the reaction vessel. The pumping speeds were adjusted to empty both tanks at the same time, usually over the course of 4-6 hours. Typically this meant a pumping rate of about 50 ml of monomer (s) per hour from Tank I into the reaction vessel. The pumping speed from Tank II to Tank I was adjusted according to the desired feed composition and concentration of monomers. Monitoring of the "monomer depleted" conditions in the reaction vessel was accomplished by periodically sampling the reaction mixture. The total amount of polymer formed at the time of sampling was compared with the amount of added monomers. Normally, the reactions had a degree of polymerization of 90-10Θ "at any point in time. 709842/0735

- W-

In addition, infrared absorption analysis of these samples showed the change in the composition of the polymer with the passage of time. The reaction mixture was prepared by pouring the mixture into a 2-3 liter v / ater jar containing either H ₂ SO ^ or Al ₂ (SO ^ K to break up the emulsion. This material was then filtered, washed well with methanol and dried overnight in a vacuum oven at about 70 ° C. This gave compression-molded films (about 0.43 mm) which were analyzed (see the following examples).

Specific examples of interpolymerization reactions with styrene and acrylonitrile are given below. In these In the examples, the feed rate from tank I to the reaction vessel was always about 50 ml / hour. In the following examples the polymerization process mentioned above as preferred and the initial charge to the reaction zone were used, unless otherwise stated.

The following examples serve to explain the present invention in more detail. Parts and percentages are by weight unless otherwise indicated.

example 1

In this example, a non-uniform proportion as well as polystyrene and styrene-acrylonitrile mixed polymer proportions were obtained.

Tank I was charged with 60 grams of styrene. After this material had been pumped into the reaction vessel (50 ml / hour), Tank I was charged again with 40 g of styrene, while Tank II was charged with 29 g of styrene and 11 g of acrylonitrile (weight ratio 72:28), The non-uniform polymerization was carried out according to the preferred polymerization scheme described above. During the reaction, the volume of the monomers was in

709842/0735

- ar-

ffc 27Ί3 "32

Tank I and Tank II about the same; the pumping speed from Tank II to Tank I was set to about 25 ml / hour. and from tank I into the reaction vessel at about 50 ml / hour. set. Upon completion of the non-uniform polymer fraction, Tank I was charged again with 43 g of styrene and 17 g of acrylonitrile and the reaction was continued at the same pumping rate (50 ml / hour). After working up, the polymer composition obtained had a proportion of 30 % polystyrene, a proportion of 30 % of the styrene-acrylonitrile mixed polymer and a non-uniform proportion of 40 % .

Example 2

The course of the reaction of Example 1 was repeated to obtain a polymer having an identical composition.

Tank I was sent with 60 grams of styrene and acrylonitrile (weight ratio 72:28) and the charge was transferred to the reaction vessel. Tank I was then charged with 40 g of the same styrene-acrylonitrile monomer mixture and Tank II with 40 g of styrene. The polymerization was carried out in a manner similar to Example 1 (with the same pumping speeds). Upon completion of this non-uniform portion, Tank I was again charged with 60 g of styrene. The reaction continued. After completion, the mixture was worked up according to the general procedure described in Example 1.

The overall yield obtained in Examples 1 and 2 was about 90 % with each product containing 14% acrylonitrile.

Example 3

A compatible styrene-styrene-acrylonitrile polymer was obtained in this experiment.

7098A2 / 0735

Tank I was charged with 100 g of styrene and Tank II with 100 g of styrene and acrylonitrile (weight ratio 72:28). The polymerization was carried out in a manner similar to that in Example 1. The feed rate from Tank I to the reaction vessel was increased to about 50 ml / hr. and from tank II to tank I to 25 ml / h. set. The product obtained was a non-uniform copolymer of styrene and styrene-acrylonitrile. The overall yield of the reaction was 90-9h % after the product had been worked up as in Example 1. The product contained 14% acrylonitrile.

With this polymer can be practically clear or transparent Mixtures of polystyrenes and styrene-acrylonitrile mixed polymers ■ are produced.

Example 4

In this experiment a compatible styrene / styrene-acrylonitrile polymer was made.

Tank I was charged with 130 g of styrene and acrylonitrile (weight ratio 72-28) and tank II with 66 g of styrene. The polymerization was carried out by the same procedure as in Example 1. The pumping rate of tank I for R _e action vessel was about 50 ml / min., And the pumping rate of tank II in tank I was about 17 ml / hr. The product obtained was ■ a non-uniform styrene-acrylonitrile copolymer ■ with a total acrylonitrile content in the reaction vessel charge of 18.7 % a styrene-acrylonitrile copolymer. The overall yield after work-up was 88 %.

This polymer can be used to produce practically transparent mixtures of polystyrenes and styrene-acrylonitrile copolymers.

709842/0735

271? ^ 3 2

Example 5

A compatible styrene / styrene-acrylonitrile polymer was used in this experiment manufactured.

Tank I was charged with 134 g of styrene and Tank II with 66 g of styrene and acrylonitrile (weight ratio 72:28). The polymerization was carried out by the same procedure as in Example 1. As in Example 4, the pumping speeds were about 50 ml / hour. from tank I into the reaction vessel and about 17 ml / hour. from Tank II to Tank I. The product obtained was a non-uniform styrene-acrylonitrile copolymer with a total acrylonitrile content of 9.3% in the monomer charge. This resulted in a slower gradation of the polymer at the end of the styrene reaction, allowing better association with a polystyrene. The overall yield after work-up was 93 % »

This polymer can be used to produce practically transparent mixtures of polystyrenes and styrene-acrylonitrile copolymers be used.

Comparative experiment A

For comparison purposes, a standard reaction was carried out with the monomer feed which contained a constant acrylonitrile concentration of 14% throughout the reaction. Tank I was charged with 172 grams of styrene and 28 grams of acrylonitrile. The polymerization was carried out according to the same procedure as in Example 1, except that the monomer mixture was only fed from tank I (50 ml / hour). The overall yield was 95%.

The mechanical properties of some of the polymer products from the above examples were determined and compared to the properties of polystyrene and a styrene-acrylonitrile copolymer (24 % acrylonitrile). The results are

709847/0735 ORIGINAL INSPECTED

listed in Table I. 40 parts of the polymer from Example 4 were also mixed in a roller mill (190 ° C.) with 30 parts of the styrene-acrylonitrile mixed polymer - this mixture was designated as Experiment 5. Another mixture was prepared which contained 40 parts of the polymer obtained in Example 4, 30 parts of the styrene-acrylonitrile mixed polymer and 30 parts of polystyrene - it was designated as Experiment 6. The mechanical properties of each of these materials are listed in Table I. They were compared with the mechanical properties of a mixture in the ratio 1: 1 (roller mill) of polystyrene and the styrene-acrylonitrile mixed polymer (24 % acrylonitrile), which was designated as Experiment 7.

Tabel

material Tensile module train
strength strain
until
fracture Izod blow
festi ^ k ^ it,
cmkcr / cn TG. ,
OC S-A 390,000 9,400 3.5 32.64 100 Poly
styrene 334,000 4,960 1.6 21.76 100 Example 1 370,000 5.26ο 1.7 16.32 - Example 2 364,000 5.110 1.5 21.76 105 Belsp. 3 373,000 7,000 2.5 16.32 - Attempt 5 381,000 7,530 2.3 10.88 - Vers. 6 380,000 5,300 1.6 16.32 105 Vers. 7 372,000 5,470 1.5 10.88 - comment : S-A is a styrene-acrylonitrile copolymer (24 %

Acrylonitrile).

The transmittance and the haze in % were measured (corrected to a thickness of 0.43 mm) in order to determine the transparency of the film as an indication of the compatibility.

709842/0735

The permeability data in% agreed very well with the turbidity data in> ί. The turbidity in Ji for films of each of the polymers and blends with the styrene-acrylonitrile mixed polymer (24 % acrylonitrile) (40:30) , measured with polystyrene (40:30) and with both polystyrene and the styrene-acrylonitrile copolymer (24 % acrylonitrile) (40:30:30) - the results are listed in Table II.

material

AS
PS

Example 2
Example 3
Example 4
Example 5

Tab 1 1 e

material

6.7

8.7 14.3

6.9

8.7 10.4

Material + A-S

91.3 14.4 10.2 10.0 28.7

II

Material + PS

91.3

25.7 18.4 35.4 11.9

Material + A-S + PS

43.3 34.8

49.3

Notes: PS is polystyrene.

AS is a styrene-acrylonitrile mixed polymer (24 % acrylonitrile).

It is an improvement in clarity due to better compatibility (and / or gradation) in those of the present invention Products compared to a mixture of a styrene-acrylonitrile mixed polymer (24% acrylonitrile) and polystyrene in a 50:50 ratio.

A thin film of the polymer from Example 3 exhibited excellent adhesion between polystyrene and the styrene-acrylonitrile copolymer (24 % acrylonitrile). There was also an excellent match between high-impact polystyrene and ABS

709842/0735

Liability received. All samples were made by placing at 19 »
became

pressed at 190 ⁰ C and a pressure of 2.8 kg / cm plates

Module temperature and rebound temperature curves were obtained for the product of Example 2, the product of Example 3, a 50:50 blend of polystyrene and a styrene-acrylonitrile copolymer (24 % acrylonitrile), a blend of the product of Example 3 with polystyrene and a styrene-acrylonitrile mixed polymer (24 % acrylonitrile) (40:30:30). These curves were compared with curves for polystyrene and a styrene-acrylonitrile copolymer (24% acrylonitrile). The curves were the same in all cases; however, no curve was as sharp as the rebound temperature curve of the styrene-acrylonitrile mixed polymer (24% acrylonitrile). The composition of the invention and mixtures of these showed a slightly higher Tg (105 ⁰ C) than polystyrene (1OO ° C) or the styrene-acrylonitrile copolymer (24% acrylonitrile) (100 ⁰ C).

709842/0735

L e r s e i t e

Claims (3)

--26T- claims: 1. Transparent polymer material which comprises a polystyrene component, a non-uniform mixed polymer of styrene and acrylonitrile and a styrene-acrylonitrile mixed component, characterized in that the non-uniform polymer component has been produced by a process, which comprises the following stages: - supply of at least one primary polymerizable feed composition from the monomer group: Styrene, acrylonitrile and a mixture of styrene and acrylonitrile from at least one primary broom in the vile in a polymerization zone, the primary polymerizable Charge composition in the concentrations of the polymerizable reaction stones contained therein is constantly changed during continuous feeding; - Simultaneous feeding of at least one other secondary polymerizable feed composition from the group of monomers: styrene, acrylonitrile and a mixture of styrene and acrylonitrile from at least a secondary feed source to the primary feed source, the concentration of the polymerizable reactants in the primary polymerizable Constantly changing feed composition in the primary feed source; and - continuous polymerisation of the polymerisable feed composition introduced into the polymerisation zone, until the desired polymerization is achieved, this polymerization becoming depleted in monomers Conditions is carried out and the primary polymerizable feed composition is different from that secondary polymerizable feed composition. 709842/0735 ORIGINAL INSPECTED 2. Material according to claim 1, characterized in that it contains about 20-40 % by weight, preferably about 30% by weight, of the non-uniform polymer fraction. 3. Transparent polymer, in particular a polymer alloy, characterized in that it comprises the transparent polymer material according to claims 1-2, optionally together with styrene, acrylonitrile or copolymers of these. 709842/0735