JPS6143612A - Preparation of heat-and impact-resistant resin - Google Patents

Abstract

PURPOSE:To obtain the titled resin having improved mechanical strength, by emulsion graft copolymerizing styrene and methacrylic acid with a rubber-like polymer latex, and transferring the polymerization system to a suspension state to carry out the suspension graft copolymerization. CONSTITUTION:(B) Styrene and (C) methacrylic acid are (continuously) added to (A) a rubber-like polymer latex, e.g. polybutadiene, to carry out graft copolymerization, and the resultant graft polymer latex is partially salted out with CaCl2, etc. preferably at 80-100% conversion. A partially saponified polyvinyl alcohol (PVA), etc. is subsequently added to transfer the polymerization system to a suspension state. Both above-mentioned monomers are simultaneously added ir styrene is added, and methacrylic acid is then added to complete the graft copolymerization and give the aimed polymer. The component (A) is used in an amount of 3-40wt% based on the copolymer, and the ratio (B/C) of the component (B) to (C) is preferably 97-70/3-30wt%. 1-20wt% styrene may be replaced with another copolymerizable vinyl monomer.

Description

DETAILED DESCRIPTION OF THE INVENTION In more detail, styrene and methacrylic acid in the presence of a latex-like rubbery polymer are
As an i-body, a specific emulsion-! ! This invention relates to an improved method for producing moldable thermoplastic styrene-methacrylic acid copolymer resins with excellent T81 mechanical strength, which comprises graft copolymerization using a turbidity polymerization method, and which is used as various molding materials.

Styrene-methacrylic acid copolymer resin is a type of styrene resin that is used as a molding material with extremely high heat resistance in a wide range of fields such as home appliance parts, automobile parts, OA equipment, and precision equipment. be.

By the way, -rN has recently filed a patent application for an impact-resistant styrene/methacrylic acid copolymer resin obtained by making full use of its unique polymerization technology as a rubber-reinforced brand with high impact resistance (patent application). Showa 58-2133
No. 12 and No. 59-38358).

The resin according to these inventions has heat resistance and #411g! In addition to having both physical properties and physical characteristics, it is located between conventional general-purpose resins and engineering plastics, so it is attracting attention in anticipation of future demand trends in these fields. It is something that should be done.

Therefore, it is used in fields where both high heat resistance and tMil' resistance are required, such as instruments, etc.
Automobile related parts such as panels, heater ducts or tail lamp housings, home appliance parts such as near conditioner ducts, breaker covers, TV cabinets, hair curlers or iron handles, V
Cassette for TR tape, cassette for audio tape,
Floppy disk case or 0Alli! OA related parts such as housings, optical related parts such as camera or projector housings or slide magazines, food container parts such as microwave tableware, or l! This will lead to the expansion of the use of -1 into various paddle fields such as insulation materials for stages.

[Conventional technology]

In order to prepare impact-resistant styrene-methacrylic acid copolymer resin using such a promising material, bulk polymerization, solution polymerization, and bulk polymerization methods can be used. ! Both turbidity polymerization method and emulsion polymerization method can be used, but the heat resistance and impact resistance are short.
Moreover, in order to obtain a resin with good appearance of molded products such as surface gloss, styrene and methacrylic acid are emulsion polymerized in the presence of a rubbery polymer latex, or the emulsion polymer obtained in this way is It is necessary to use a polymer blend method consisting of a styrene/methacrylic acid copolymerized 4M resin and a styrene/methacrylic acid copolymer resin.

Therefore, we used latex-like rubber (rubber-based latex) as the rubbery polymer and peroxide as the initiator.
When graft copolymerization is carried out at 40 to 100 tons in an emulsified state, the emulsion system becomes unstable during such polymerization because methacrylic acid causes enlargement or destruction of the latex, and often results in agglomeration (IJ). You may also experience symptoms that lead to #-like symptoms.

In order to overcome these difficulties in the prior art, the present inventors used a special method to continuously add a portion of the methacrylic acid used as the polymerization progresses.
We have discovered that it is possible to suppress the concentration of latex during polymerization, and to make the copolymer composition uniform in terms of physical properties, resulting in a product with superior impact strength compared to the batch addition method. , and both previously filed applications.

[Problem that the invention seeks to solve]

However, as long as you follow the special measures mentioned above,
When coagulating the graft copolymer latex and recovering the resin, the latex must be salted out, granulated to facilitate filtration, and then filtered, washed, hydrophilized, and then dried, which is a complicated process. This requires a lot of labor and utility costs such as electricity.
Furthermore, the powder with low bulk density obtained by emulsion copolymerization and bead-shaped or pellet-shaped styrene/methacrylic acid copolymer resin are blended using an extruder to produce a molding material. In some cases, special equipment is required to prevent bridging in the hopper, a screw structure is required to uniformly knead both resins, or expensive equipment such as a two-wheel extruder is required. It is often necessary.

[Means for solving problems]

However, the present inventors have attempted to solve the above-mentioned problems in the emulsion polymerization method or the emulsion-blending method (as a result of extensive studies, we have developed the emulsion-amim polymerization method described below, which changes the state from an emulsion state to a suspension state). A resin that can be transferred smoothly and that can provide molded products with dramatically superior mechanical strength while retaining the inherent heat resistance and induction shock resistance compared to conventional manufacturing methods. The present invention was completed based on the discovery that the following could be obtained.

That is, the present invention involves a step of graft copolymerizing styrene and methacrylic acid in an emulsified state to a rubbery polymer latex, partially salting out the graft copolymer latex obtained in this way, and then! ! ! In a method for producing a heat-resistant and impact-resistant resin, which comprises a step of carrying out a pre-turbid state and a step of completing graft copolymerization in this suspended state, a salting-out agent and a suspension stabilizer are first added, and then Thereafter, the monomers styrene and methacrylic acid are added simultaneously, or styrene is added and then methacrylic acid is added to convert the suspension into a suspension state, and this suspension state is then reacted in the presence of an initiator. The present invention provides a method for producing a heat-resistant and impact-resistant resin, which comprises completing graft copolymerization.

The method of the present invention will be explained in detail below. First, as a method for preparing this type of impact-resistant resin, recently, emulsion polymerization is first carried out, and then the obtained graft copolymer latex is suspended. The so-called emulsion-gm polymerization method, in which the reaction is completed by suspension polymerization by converting the material into a cloudy state, has become well known.

Regarding this manufacturing method, please refer to acrylonitrile/butadiene rubber/styrene copolymer resin (ABS resin) or methyl methacrylate/butadiene rubber/styrene copolymer resin (
A large number of patent applications have been filed, including lIn5 resin).
In order to transition from an emulsified state to a suspended state, measures suitable for each resin have also been devised.

However, in the case of styrene/methacrylic acid copolymer resin, when the system is transferred from an emulsion system to a suspension system, methacrylic acid as a monomer has a large effect on the aqueous dispersion state. As long as the conventional technology is followed, the actual situation is that agglomeration (cake-like formation) often occurs during the demulsification failure of 14F, which can be called partial salting out, and it becomes impossible to obtain a stable suspension state. For example, in Japanese Patent Publication No. 43-21073, polymerization is initiated using a rubbery polymer latex (rubber-based latex), styrene, and acrylonitrile, and a water-soluble polymerization initiator and an oil-soluble polymerization initiator. , a method for preparing ABSiMN has been disclosed in which the reaction proceeds in an emulsion polymerization system in the early stage, and in the latter stage, the reaction is transferred to a suspension polymerization system in the presence of a fi turbidity stabilizer to complete the reaction. Even if the method was repeated using methacrylic acid instead of acrylonitrile, the viscosity increased during the polymerization and eventually coagulated and became impossible to stir. ! ! Styrene/methacrylic acid copolymer resin
It was impossible to create one.

In contrast, the present invention provides an improved emulsification-suspension method for producing impact-resistant styrene-methacrylic acid copolymer resins that have both high heat resistance and impact resistance, and also have excellent mechanical strength. The present invention provides a polymerization method, and its features include an emulsion polymerization step for grafting styrene and methacrylic acid onto fi+ rubbery polymer latex, and (2) a graft copolymer obtained in this manner. A step of partially salting out the latex and transitioning it to a suspended state;
Furthermore, (3) this! ! ! ! It consists of three major steps: the step of completing the graft copolymerization in a cloudy state, and the step of transitioning from an emulsion system to a layer system, that is, the above-mentioned (
2) In the step, first, a salting-out agent and a suspension stabilizer are added to cause partial salting-out, and then the monomers, that is, styrene and methacrylic acid, are added at the same time, or the styrene is first added.
Subsequently, methacrylic acid is added separately in this order to completely transform the suspension into a suspended state.

In the present invention, the term "partial salting out" does not refer to a state in which latex aggregates into a cream-like state, but a state in which the latex particles themselves have agglomerated but are still uniformly dispersed. I would like to understand that this is a word that refers to

Moreover, in carrying out the method of the present invention, as mentioned above, in order to form a stable suspension system from the emulsion system, a salting-out agent is used! ! Only by following the unique addition order of stabilizers and monomers can the object of the invention be achieved.

Here, since methacrylic acid, which is an essential monomer of the present invention, exhibits acidity in an aqueous solution, it has an aggregating effect on latex, and moreover, it is necessary to note that methacrylic acid, which is an essential monomer of the present invention, has an aggregating effect on latex. The timing of addition of methacrylic acid is a key point in reliably carrying out the emulsion-suspension polymerization method, since it has a significant effect on the viscosity of the liquid.

In other words, it is best to add methacrylic acid either after or at the same time as styrene; if it is added before styrene, the latex will coagulate and the system will become creamy. As a result, it becomes difficult to transfer to the ↓ layer system.

Although it is possible to add both polymers of styrene and methacrylic acid by bulk addition or continuous Vt addition, it is necessary to obtain and maintain a stable aqueous dispersion state with low viscosity. It is preferable to use a continuous addition method.

By doing so, the latex particles and these ffi-mers do not cause aggregation and agglomeration (cake-like formation), and also prevent the generation of abnormal particles caused by aggregation of latex particles. It is now possible to suppress the

The suspension stabilizer may be added either before or after the salting-out agent is added, but it is preferable to add the monomers styrene and methacrylic acid.

If these two vehicle mass bodies are added, it will be difficult to achieve a suspended state, and this may even lead to agglomeration (cake-like formation) during the process, so this method should be avoided. It is.

In addition, if necessary, the salting-out agent may be added after the suspension system has been transferred.

In this way, the time to transition to a suspended state (!!turbid system) by adding a salting-out agent is determined by the polymerization rate of the monomer mixture during the ill step, that is, the emulsion polymerization step (during emulsion polymerization). It may be at any time as long as it is 50 to 100%, and preferably a polymerization rate of 80 to 100% is suitable.

If the polymerization rate is too low, transferring to a suspension system is not preferable because the final product will not have excellent physical properties.

If this emulsion polymerization is not carried out at all, but the rubbery polymer latex is salted out, the iti substance mixture is swollen and melted, and the reaction is then completed by suspension polymerization, the resulting molded product number It was also found that it was too brittle to be put to practical use.

Also, emulsification improved as in the method of the present invention-2! As a result of measuring various physical properties of molded products of impact-resistant styrene/methacrylic acid copolymer resin obtained by the turbidity polymerization method, it was found that among the mechanical strength, the DuPont impact strength was lower than that of the molded products made by the emulsion-blending method. It was also found that there was a dramatic improvement compared to .

By the way, when using this emulsion-blending method, physical properties such as eye shift impact strength, tensile strength, and bending strength were comparable, but DuPont impact strength is considered to be more similar to the practical strength of actual molded products. high values could not be obtained.

In general, rubber-modified copolymer resins consist of a copolymer grafted to a rubbery polymer and a free copolymer that does not participate in the grafting. Resistance of modified copolymer 414 fat! It is also known that the content of the rubbery polymer, its particle diameter, the grafting rate, the average molecular weight, its distribution, etc. are important factors for developing ionic impact properties.

That is, for example, one of the reasons for this problem is how to suppress the aggregation of the grafted rubbery polymers during the polymerization or extrusion process and uniformly disperse them into the resin phase. In many cases, small protrusions occur on the resin surface and the mechanical properties cannot be fully exhibited.

Conventionally, in order to avoid or fundamentally eliminate this y5 state, there have been methods of combining a graft copolymer latex and a lubricant, or using a copolymer resin that has been separately emulsion copolymerized in latex form to modify this rubber. There is a method of mixing it with a copolymer resin, coagulating it, and turning it into powder.

On the other hand, it is conceivable that impact-resistant styrene-methacrylic acid copolymer resins with significantly improved DuPont impact strength can be easily obtained using a modified emulsion-suspension polymerization method such as the method of the present invention. By gradually transitioning from an emulsifying system to a cloudy system, the grafted rubber l! This is thought to be because uniform dispersion of the polymer into the resin phase is achieved during the polymerization process, and this effect is sufficiently expressed.

The impact-resistant styrene-methacrylic acid copolymer resin, which is the final product obtained by the method of the present invention, is made of rubber? [Fusion 3
~40 parts by weight and a total amount of both vinyl monomers styrene and methacrylic acid, or if necessary, a total amount of other vinyl monomers, from 97 to 60 parts by weight,
And the breakdown of the vinyl monomers is 97 to 70% by weight of styrene and 3 to 30% by weight of methacrylic acid.
mm% of other vinyl tPL copolymerizable with this styrene
Typical examples of such copolymerizable vinyl monomers include α-methylstyrene, tert-butylstyrene, various halogen F [styrene, vinyltoluene (meth)7, IJLl, etc. Nitrile, alpha
-Chloroacrylonitrile or various (meth)acrylic acid esters.

If the rubbery polymer content is less than 111 parts of 3F, it has no practical value due to low impact resistance (on the contrary, it has no practical value)
If it exceeds 0 parts by weight, fluidity and processability will deteriorate, which is not preferable.

Furthermore, the total amount of styrene and methacrylic acid added at the end of emulsion polymerization is suitably within the range of 50 to 300 parts by weight based on 100 parts by weight of the solid content of the grafted latex (graft copolymer latex). However, it is not particularly limited thereto, and as long as the composition of the final product is within the above-mentioned range, clause 'rI4 can be used as appropriate.

The composition of the monomer mixture added when carrying out cloud polymerization does not need to be the same as that used during emulsion polymerization, and can be changed as appropriate in accordance with the required performance of the resin.

Regarding the previous step in the method of the present invention, that is, the emulsion polymerization step, the above-mentioned 1ζ patent applications, especially Japanese Patent Application No. 58-213
As described in the specification of No. 312, the initiator, chain transfer agent, antioxidant, etc. used in this case are not particularly limited, and any known and commonly used ones can be used as they are.

However, type a surfactants (emulsifiers) are important for the stability of the emulsion system, and various sulfate-type and sulfonate-type anionic surfactants are used in this case. The use of metal salts of higher fatty acids, which are commonly used in polymerization, is not preferred because it causes demulsification during polymerization.

In addition, as a method of adding methacrylic acid, first 1 to 7 of the total methacrylic mu used in emulsion polymerization is added to the reaction initiator.
0% by weight, preferably in the range of 1-50% by weight, and then the remaining amount, i.e. 99-30% of the total amount of methacrylic acid. Ei weight%, preferably 99-50% by weight
1iil hit! As the polymerization progresses, the amount in Il is
A special method of continuous addition until the polymerization rate reaches 90% is recommended.

Further, as the suspension stabilizer (dispersant) used in carrying out the method of the present invention, ordinary organic dispersants can be used as they are. Particularly representative among them are partially saponified polyvinyl alcohol, partially saponified polymethyl methacrylate, polyacrylic acid or its salts, cellulose, methylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, polyalkylene oxide, polyvinylpyrrolidone, sulfonated Examples include polystyrene and alkylbenzene sulfonates, and these may be used alone or in combination of two or more.

On the other hand, typical salting-out agents for partial salting-out include sodium chloride, potassium chloride, sodium sulfate, Ii[r
711 magnesium, calcium chloride, aluminum chloride, etc., but of course, in addition to these, electrolytes commonly used for salting out latex can be used as they are.

Also,! ! ! As the initiator for the i-turbidity polymerization, known and commonly used oil-soluble initiators can be used as they are, but lauroyl peroxide, benzoyl peroxide, azobisisobutyronitrile, etc. are particularly representative.

Furthermore, in order to adjust the molecular weight of the target resin obtained, tertiary dodecyl mercaptan or α-methylstyrene.
Chain transfer agents such as Gwimar can be used.

Furthermore, typical rubbery polymer latexes (rubber-based latexes) include polybutadiene, butadiene-styrene copolymers, butadiene-acrylonitrile copolymers, acrylic ester elastomers, and ethylene-propylene elastomers. Examples include various latexes.

Thus, in the heat-resistant and impact-resistant resin obtained by the method of the present invention, during the preparation of the impact-resistant styrene-methacrylic acid copolymer resin, that is, during emulsion or suspension polymerization,
It is also possible to add plasticizers, pickling agents, stabilizers, ultraviolet absorbers, etc. that can be dissolved in the weight temperature mixture and do not hinder the progress of polymerization.

〔Example〕

Next, the present invention will be explained in more detail with reference to Reference Examples, Examples, and Comparative Examples. In the following, all parts and percentages are based on wit unless otherwise specified.

Reference Example 1 [Preparation example of styrene/methacrylic acid copolymer resin] 200 parts of distilled water was charged into a No. 51 autoclave equipped with a stirring device, and 1 part of partially saponified polyvinyl alcohol as a suspension stabilizer and sodium dodecylbenzenesulfonate were added. 0.005 parts of styrene, 15 parts of methacrylic acid, 0.2 parts of ditert-butyl peroxyhexahydroterephthalate, and 0.1 parts of perbenzoic acid. Tertiary butyl was charged one after another, the temperature was raised to 90°C while stirring at a rotational speed of 400 rpm, the temperature was maintained for 10 hours to carry out suspension polymerization, the reaction was further continued at 120°C for 3 hours, and then The resulting beaded styrene/methacrylic acid copolymer resin was washed, dehydrated, and then dried to obtain the desired resin.

Reference Example 2 [Preparation Example of Graft Copolymer] In a reactor similar to Reference Example 1, the following substances were charged.

Polybutadiene latex 87 parts (solid content -57.4%) Steel
40 #metallic acid 3
Potassium persulfate 0.3#Tertiary dodecylmercapkun 0.1#Sodium dodecyl lebenzenesulfonate 2#Steamed
Distilled water 200%Next, nitrogen gas was introduced into this reactor and 700% distilled water was introduced while stirring.
The temperature was raised to .degree. C., and after reaching the same temperature, 7 parts of methacrylic acid was continuously added over 3 hours, and emulsion polymerization was further carried out at the same temperature for 2 hours to complete the reaction.

A 10% aqueous solution of calcium chloride adjusted to 5% based on the solid content of the graft copolymer latex thus obtained was added, and the latex was coagulated at 90 to 110°C with stirring, and then Filter, wash with water,
IRX Sase.

Thereafter, it was dried to obtain the desired powdery graft copolymer.

Example 1 11 of the graft copolymer latex obtained in Reference Example 2
9 parts and 130 parts of distilled water were charged into a reactor and heated to 50°C.
The temperature rose to .

The latex was partially salted out by adding 10 parts of a 10% aqueous calcium chloride solution and 2.5 parts of an 8% partially saponified aqueous polyvinyl alcohol solution under stirring at 300 rpm, followed by the addition of 55 parts of styrene. At this point, the dispersion had converted to a completely limpid state.

Then 10 parts of methacrylic acid was added and then 0.
2 parts of tert-butyl peroxyhexahydroterephthalate, 0.1 part of tert-butyl perbenzoate, and 0.1 part of tert-dodecyl mercaptan were charged sequentially.

After completing these preparations, the temperature of this suspension was raised to 90°C,
Heat polymerization at the same temperature for 5 hours, then further at 120℃
The reaction was continued for 3 hours to obtain bead-shaped graft copolymer resins, which were then washed, dehydrated, and dried.

After that, "Irganox 107" was applied to this copolymer resin.
0.2 part of 6J (I!i, an antioxidant manufactured by Nava Geigy, Germany) was added, and the mixture was pelletized using an extruder with a cylinder temperature of 230°C.

Next, injection molding was performed using this pellet, and the physical properties of the molded articles thus obtained were measured and are summarized in Table 1.

Example 2 Grafting was carried out in the same manner as in Example 1, except that the monomer addition method was changed to continuous addition of a mixed solution of 55 parts of styrene and 10 parts of methacrylic acid over 1 hour. A polymer resin was obtained.

Example 3 13 of the graft copolymer latex obtained in Reference Example 2
6 parts and 120 parts of distilled water were charged into the same reactor as in Example 1, and the temperature was raised to 50°C. Under stirring at 350 rpm+a, 10 parts of 109A calcium chloride aqueous solution and 8
2.5 parts of an aqueous solution of partially saponified polyvinyl alcohol were added to partially salt out the latex, and then 51 parts of styrene was added to convert it into a suspension.

Thereafter, 9 parts of methacrylic acid was added and an additional 0.
2 parts of tert-butyl peroxyhexahydroterephthalate, 0.1 part of tert-butyl perbenzoate and 0.1 part of tert-dodecyl mercaptan were added sequentially.

Next, heating polymerization was carried out at 90°C for 5 hours, and further 120°C
The reaction was continued at ℃ for 3 hours, resulting in the graft copolymerization 4! Fat A was treated in the same manner as in Example 1, and the Rf value of the physical properties was determined.

Example 4 The desired graft copolymer resin was obtained in the same manner as in Example 3, except that 41 parts of styrene and 10 parts of methyl methacrylate were used instead of 51 parts of styrene.

Comparative Example 1 This example is about W type classification by emulsification-blending method. First, 40 parts of the powdered graft copolymer resin obtained in Reference Example 2 and the bead-like 60 parts of styrene-methacrylic acid copolymer resin and 0.2 parts of Irganox 1076J were mixed and pelletized using an extruder with a cylinder temperature of 260°C.

Next, the pellets were injection molded, and the physical properties of the molded products thus obtained were measured, and the results are summarized in Table 1.

Comparative Example 2 This example is also about a preparation example by emulsion-blending method, but 35% of the powdered graft copolymer resin of Reference Example 2
The pellets were made into pellets in the same manner as in Comparative Example 1, and then injection molded, and the physical properties were measured, except that the ratio was changed to 65 parts of the beaded styrene/methacrylic acid copolymer resin of Reference Example 2. Table 1 shows the places we visited.

Table 1 shows the physical properties of the molded products obtained in each of the above Examples and Comparative Examples. Of these, the Izot impact strength is in accordance with ASTM D-256, and the tensile yield point strength and bending strength are in accordance with ASTM D-256. D-
638 and D-790, and the heat distortion temperature is 8 STM D under the condition that the maximum fiber stress is 18.6 kg/-.
-648.

In addition, the DuPont impact strength was measured using a DuPont TFI impact tester manufactured by A1 Toyo Seiki Seisakusho, and the diameter of the striking tip tip was 4 inches, and the thickness of the striking center receiver was 4.0 inches, with a base diameter of 4 inches.
A weight of 500 g was dropped from an arbitrary height onto a molded product fi, and the height at which cracks appeared in the molded product was measured.

[Effects of the Invention] As mentioned above, an object of the present invention is to provide a method for producing impact-resistant styrene/methacrylic acid copolymer resin by emulsion-suspension polymerization. In summary, the advantages of following this method are that a copolymer resin with extremely superior mechanical strength can be obtained compared to conventional methods, and that the polymerization process is finally completed in the form of ai!QS synthesis. The 4MIIFl produced in the form of beads with extremely high filterability does not require a salting-out step as seen in ordinary emulsion polymerization methods, and the subsequent washing, dehydration, and drying steps are not required. It also has excellent workability.As a result, it is easy to understand that economic efficiency is significantly improved.

Agent: Patent Attorney Ko Kei Writ Procedural Amendment September-7, 1980 Manabu Shiga, Commissioner of the Japan Patent Office1, Indication of the case 1982 Patent Application No. 1648773, Relationship with the person making the amendment Patent Applicant: 174 Tokyo Department #i! 35-58 Sakashita 3-chome, Yu-ku (
288) For the representative of Dainippon Ink and Chemicals Co., Ltd.
Kuni Mura Shigeru 4, Agent: Dainippon Ink and Chemicals Co., Ltd., 3-7-20 Nihonbashi, Chuo-ku, Tokyo 103, Japan Sponsored by 6, Section 7 of "Detailed Description of the Invention" of the subject of amendment II'gF , Contents of amendment (1) The statement on page 20, line 20 of the specification is corrected as follows.

"And the bead-shaped styrene/meccrylic acid copolymer tree of Reference Example 1"

Claims (1)

[Claims] 1. A step of graft copolymerizing styrene and methacrylic acid in an emulsified state to a rubbery polymer latex, then partially salting out the graft copolymer latex obtained in this way, and then turning it into a suspended state. In the method for producing a heat-resistant and impact-resistant resin, which comprises a step of transferring the mixture and a step of completing the graft copolymerization in the suspended state, a salting-out agent and a suspension stabilizer are first added, and then a simple The polymer styrene and methacrylic acid are added simultaneously, or styrene is added and then methacrylic acid is added to transform the suspension into a suspension, and this suspension is then grafted in the presence of an initiator. A method for producing a heat-resistant and impact-resistant resin with excellent mechanical strength, characterized by completing polymerization. 2. A rubbery polymer containing 3 to 40 parts by weight of the heat-resistant and impact-resistant resin, and a total amount of 97 to 97 parts by weight of styrene and methacrylic acid.
A moldable thermoplastic resin obtained by copolymerizing styrene and methacrylic acid in a ratio of 60 parts by weight, and in which the percentages of styrene and methacrylic acid described above are 97 to 70% by weight and 3 to 30% by weight. A manufacturing method according to claim 1, characterized in that: 3. The monomeric styrene mentioned above is 1 to 20 of the styrene.
3. The method according to claim 1, wherein the styrene is replaced by another vinyl monomer copolymerizable with the styrene within a range of % by weight.