JPH0583578B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a multilayer structure polymer resin composition, and more specifically, it is made by blending a specific thermoplastic resin with a multilayer structure polymer having excellent flexibility, transparency, and weather resistance. The present invention relates to a multilayer structure polymer resin composition having no or extremely low properties. Generally, as a means to improve the impact resistance of thermoplastic resins, various attempts have been made to introduce so-called rubber components into the resins. The most common method for this is to introduce diene rubber, but since diene rubber has extremely poor weather resistance, this method is inappropriate for applications that require weather resistance. In order to impart impact resistance without reducing weather resistance, various methods of blending acrylic rubber-based polymers have been studied, and although the problem of weather resistance has been solved to some extent, such blend systems Significant stress whitening occurs, greatly reducing its commercial value, and the transparency that can be obtained is typically subject to limitations. For example, polymethyl methacrylate (hereinafter abbreviated as PMMA), which has an extremely beautiful appearance and excellent weather resistance, is strongly desired to have improved impact resistance and elasticity. Attempts to introduce a rubber component into PMMA by simply copolymerizing the components have been proposed in the past, but in both cases, the introduction of a rubber component significantly reduces weather resistance and transparency, resulting in poor appearance. No satisfactory results have been obtained. Several methyl methacrylate-based multilayer polymers containing acrylic rubber have been proposed so far, especially from the viewpoint of molding materials for films and sheets, but these have sacrificed transparency, which is an inherent characteristic of methyl methacrylate-based resins. Moreover, stress whitening resistance, which is a common drawback of impact-resistant resins, has hardly been improved. In order to obtain a thermoplastic resin composition with excellent transparency, weather resistance, impact resistance, and stress whitening resistance, it is necessary to use a crosslinked elastic layer and a resin layer mainly composed of alkyl acrylate, which have been proposed so far. At present, a satisfactory thermoplastic resin composition cannot be obtained even if a simple multilayer polymerization of the above is blended with other thermoplastic resins. In view of the current situation, the present inventors have conducted intensive studies to obtain a thermoplastic resin composition having the above-mentioned properties, and as a result, have developed a multilayer structure polymer having a specific structure and excellent flexibility, transparency, and weather resistance. The present inventors have discovered that by blending a specific thermoplastic resin within a specific range, a thermoplastic resin composition with excellent transparency and no or very little stress whitening property can be obtained, and the present invention has been achieved. That is, the present invention provides the following multilayer structure polymer []99
It is a multilayer structure polymer resin composition consisting of ~1% by weight and 1 to 99% by weight of a thermoplastic resin. Multilayer structure polymer [ ]: (A) 80 to 100 parts by weight of alkyl acrylate having an alkyl group having 1 to 8 carbon atoms and/or alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms (A ₁ ), 0 to 100 parts by weight 20 parts by weight of a monomer having a copolymerizable double bond (A ₂ ), 0 to 10 parts by weight of a polyfunctional monomer (A ₃ ), and the total of (A ₁ ) to (A ₃ ) It consists of a polymer of 0.1 to 5 parts by weight of a grafting agent per 100 parts by weight, and the proportion in the multilayer structure polymer is 5 to 5 parts by weight.
35% by weight of the innermost layer polymer (A); (B) 80 to 100 parts by weight of an alkyl acrylate (B ₁ ) having an alkyl group having 1 to 8 carbon atoms; 0.1 to 100 parts by weight of a monomer having a heavy bond (B ₂ ), 0 to 10 parts by weight of a polyfunctional monomer (B ₃ ), and 100 parts by weight of the total amount of (B ₁ ) to (B ₃ ). A crosslinked elastic polymer (B) consisting of a polymer of 5 parts by weight of a grafting cross-agent, having a glass transition temperature of 0°C or less, and having a proportion of 45 to 80% by weight in the multilayer structure polymer; (C ) 10 to 90 parts by weight of alkyl acrylate (C ₁ ) having an alkyl group having 1 to 8 carbon atoms, 10 to 90 parts by weight of an alkyl methacrylate (C ₂ ) having an alkyl group having 1 to 4 carbon atoms, 0 to 20 Parts by weight of a monomer having a copolymerizable double bond (C ₃ ), 0 to 10 parts by weight of a polyfunctional monomer (C ₄ ), and the total of (C ₁ ) to (C ₄ ) It consists of a polymer containing 0.1 to 5 parts by weight of a grafting agent per 100 parts by weight, and consists of a crosslinked elastic polymer (B) to an outermost layer polymer (D).
one or more layers in which the proportion of alkyl acrylate (C ₁ ) monotonically decreases toward
(D) 51 to 100 parts by weight of alkyl methacrylate (D ₁ ) having an alkyl group having 1 to 4 carbon atoms; 0 to 49 parts by weight of a monomer having a copolymerizable double bond; polymer (D ₂ ), with a glass transition temperature of 60°C or higher, and a proportion of 10 to 40% in the multilayer structure polymer.
% by weight of the outermost layer polymer (D); is successively graft-bonded, and has a gel content of 65% by weight or more. Thermoplastic resin []: Following formula:

[Formula] (In the formula, X and Y each represent H, Cl, Br, or F) A homopolymer of a halogenated vinyl monomer or a halogenated vinylidene monomer, or a copolymer containing these monomers as the main component At least one polymer selected from The present invention will be explained in more detail below. The alkyl acrylate (A ₁ ) having an alkyl group having 1 to 8 carbon atoms and constituting the innermost layer polymer (A) of the multilayer structure polymer used in the present invention may be linear or branched, and may be methyl Acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, etc. are used alone or in combination, and the glass transition temperature (hereinafter referred to as Tg
(abbreviated as ) is more preferable. Further, the alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms may be either linear or branched,
Methyl methacrylate, ethyl methacrylate,
Propyl methacrylate, butyl methacrylate, etc. may be used alone or in combination. These alkyl (meth)acrylates (A ₁ ) (which includes alkyl acrylates and alkyl methacrylates) are used in an amount of 80 to 100 parts by weight (hereinafter "parts by weight" is abbreviated as "parts"). Furthermore, it is most preferable that the same monomer is used for all the multi-stage layers, but depending on the final purpose, two or more types of monomers may be mixed or different types of alkyl (meth)acrylates may be used. (meth)acrylates may be used. Furthermore, the monomer (A ₂ ) having a copolymerizable double bond is preferably an acrylic monomer other than the above, such as alkyl methacrylate, lower alkoxy acrylate, cyanoethyl acrylate, acrylamide, acrylic acid, or methacrylic acid. ,0
Used in the range of ~20 parts. As the other (A ₂ ) component, styrene, alkyl-substituted styrene, acrylonitrile, methacrylonitrile, etc. can be used in an amount not exceeding 20% by weight. Further, the polyfunctional monomer (A ₃ ) is preferably an alkylene glycol dimethacrylate such as ethylene glycol dimethacrylate, 1,3-butylene glycol methacrylate, 1,4-butylene glycol dimethacrylate and propylene glycol dimethacrylate, and divinyl Benzene, polyvinylbenzene such as trivinylbenzene, alkylene glycol diacrylate, etc. can also be used. These monomers work effectively to crosslink the layer in which they are contained, but do not work on bonding between layers with other layers. Even if the polyfunctional monomer (A ₃ ) is not used at all, a fairly stable multilayer structure polymer can be obtained as long as the grafting agent is present, but it can be used as desired depending on the required physical properties. The amount used ranges from 0 to 10 parts. On the other hand, as the grafting agent, copolymerizable allyl, methallyl or crotyl esters of α,β-unsaturated carboxylic acids or dicarboxylic acids, preferably allyl esters of acrylic acid, methacrylic acid, maleic acid and fumaric acid are used. However, allyl methacrylate has particularly excellent effects. In addition, triallyl cyanurate, triallyl isocyanurate, etc. can also be effectively used. In such a grafting cross-agent, the conjugated unsaturated bond of the ester reacts much faster than allyl acid, methallyl group, or crotyl group, and is chemically bonded. During this time, a substantial portion of the allyl group, methallyl group, or crotyl group effectively functions in the polymerization of the next layer polymer (B) and provides a graft bond between the two adjacent layers. The amount of graft cross-agent used is extremely important, and should be 0.1 to 100 parts of the total amount of the above components (A ₁ ) to (A ₃ ).
It is used in an amount of 5 parts, preferably 0.5 to 2 parts.
If the amount used is less than 0.1 part, the effective amount of graft bonding will be small, resulting in insufficient bonding between layers. In addition, if the amount used exceeds 5 parts, the amount of reaction with the crosslinked elastic polymer (B) polymerized in the second stage becomes large, resulting in a two-layer crosslinked polymer consisting of polymer (A) and polymer (B). This causes a decrease in the elasticity of the elastic body. The innermost layer polymer (A) is the graft active layer;
Tg is appropriately set depending on the required physical properties of the final polymer. Further, in general, it is advantageous in terms of quality that the crosslink density is the same as that of the crosslinked elastic polymer (B), or even higher. Note that the innermost layer polymer A and the crosslinked elastic polymer
Although it is possible that the composition is the same as (B), it is important to create a two-layer elastic body structure through two-stage polymerization rather than one-time charging, and the amount of desolvation,
It is advantageous for the polymer (A) to have a higher crosslinking density and the like. The content of the innermost layer polymer (A) in the multilayer structure polymer is 5 to 35% by weight, preferably 5 to 25% by weight,
The content of the crosslinked elastic polymer (B) is more preferably in the range of 10 to 30%. Next, the crosslinked elastic polymer that composes the multilayer structure polymer
(B) is a main component that gives rubber elasticity to the polymer, and can be copolymerized with 80 to 100 parts of an alkyl acrylate (B ₁ ) having an alkyl group having 1 to 8 carbon atoms; a monomer (B ₂ ) having a double bond,
0 to 10 parts of polyfunctional monomer (B ₃ ) and (B ₁ )
It is obtained by polymerizing 0.1 to 5 parts of a graft cross-agent to 100 parts of the total amount of (B ₃ ). As the alkyl acrylate (B ₁ ) having an alkyl group having 1 to 8 carbon atoms, the alkyl acrylates exemplified in (A ₁ ) can be used alone or in combination, and those with a low Tg are preferable. Monomer with copolymerizable double bond (B ₂ )
Although lower alkyl methacrylate is most preferred, other monomers exemplified in (A ₂ ) can also be used. Furthermore, polyfunctional monomer (B ₃ )
and the graft cross-agent are also the innermost layer polymer (A), respectively.
The example given in is used. The Tg of the crosslinked elastic body (B) alone must be 0°C or lower, preferably -20°C or lower, more preferably -30°C or lower. The content of the crosslinked elastic polymer (B) in the multilayer structure polymer is 45 to 80% by weight; if it is less than 45% by weight, the desired flexibility cannot be obtained, and on the other hand, if it exceeds 80% by weight, the multilayer structure The entire combination becomes rubbery and difficult to handle. The cross-linked elastic layer formed by graft bonding of the innermost polymer (A) and the cross-linked elastic polymer (B) has a gel content of 85
% or more, and the degree of swelling is preferably in the range of 3 to 20. Furthermore, the intermediate layer (C) interposed between the crosslinked elastic polymer (B) and the outermost layer polymer contains 10 to 90 parts of carbon atoms having 1 to 8 carbon atoms.
Alkyl acrylate (C ₁ ) having an alkyl group of 10 to 90 parts, alkyl methacrylate (C ₂ ) having an alkyl group having 1 to 4 carbon atoms, 0 to 20 parts of a monomer having a copolymerizable double bond body ( _C3 ),
0 to 10 parts of polyfunctional monomer ( _C4 ), ( _C1 ) to ( _C4 )
0.1 to 5 parts of a graft cross-agent is polymerized to 100 parts of the total amount. Components (C ₁ ) to (C ₄ ) and grafting agents are the above-mentioned (A ₁ ) to
It is the same grafting agent used in (A ₃ ) and the innermost layer polymer (A). Also in the intermediate layer (C), the grafting agent is essential in order to tightly bond each polymer layer and obtain excellent physical properties. The intermediate layer may be one layer or two or more layers,
It is necessary to form each layer so that the alkyl acrylate (C ₁ ) ratio in the multilayer gradually decreases from the crosslinked elastic polymer (B) to the outermost layer polymer (D). The content of the intermediate layer (C) in the multilayer structure polymer is 5 to
40% by weight, preferably in the range from 5 to 30% by weight. When the intermediate layer (C) consists of two or more layers, the content of each layer is preferably 5 to 25% by weight.
When the ratio of the intermediate layer is less than 5% by weight, the function as an intermediate layer is not exhibited, and when it exceeds 40% by weight, the structure of the final polymer becomes unstable. Furthermore, the outermost layer polymer that constitutes the multilayer structure polymer
(D) is involved in distributing moldability, mechanical properties, etc. to the polymer, and the component (D ₁ ) constituting this is the alkyl group exemplified in the component (A ₁ ) mentioned above. Methacrylate is used as the component (D ₂ ), and lower alkyl acrylates and the monomers exemplified as the component (A ₂ ) described above are used alone or in combination. (D ₁ ) component is 51 to 100 parts, (D ₂ ) component is 0 to 49 parts
They are used within the scope of each section. In addition, the Tg of the outermost layer polymer (D) alone must be 60°C or higher in order to obtain excellent physical properties.
Preferably the temperature is 80°C or higher. The polymer (D) alone
If Tg is less than 60°C, the final polymer described later cannot have excellent physical properties even if the gel content is 65% or more. The content of the outermost layer polymer (D) in the multilayer structure polymer is
It is 10-40% by weight. If it is less than 10% by weight, sufficient weather resistance will not be obtained, and if it exceeds 40% by weight, the ratio of the crosslinked elastic layer will decrease and flexibility will be insufficient. Furthermore, the multilayer structure polymer used in the present invention must have a gel content of at least 65%, and only when this is satisfied together with the above-mentioned special structure can it achieve excellent properties such as transparency, weather resistance, and flexibility. will be granted. In addition, the gel content in this case refers to the whole including the two-layer crosslinked elastic body itself and the graft components of the intermediate layer (C) and the outermost layer polymer (D) to the crosslinked elastic body, Here, the gel content refers to 1% by weight methyl ethyl ketone (hereinafter MEK) of the multilayer structure polymer.
This is the weight % of the insoluble matter after preparing a solution (referred to as . The gel content is the added weight of the two-layer crosslinked elastic body and the grafted chains, and this can be replaced by the grafting ratio, but in the present invention, since the polymer has a special structure, it has a gel content. This was used as a guideline for the amount of grafting. Moreover, the gel content and degree of swelling of the two-layer crosslinked elastic body refer to values measured as follows. A predetermined amount of the two-layer crosslinked elastic body was collected in accordance with JIS K6388, immersed in MEK for 48 hours at 25°C to swell, and then pulled out.
After wiping off the adhered MEK, measure its weight.
After that, MEK is removed by drying in a vacuum dryer, and the absolute dry weight, which has reached a constant weight, is read and calculated using the following formula. Swelling degree = MEK weight after swelling - Bone dry weight / Bone dry
Weight Gel content (%) = Absolute dry weight / Weight of collected sample x 100 Generally, increasing the degree of polymerization of the crosslinked elastic polymer (B) as much as possible imparts a high impact strength to the final polymer. Further, the glass transition temperature (Tg) as used in the present invention is calculated from the commonly known FOX equation: 1/Tg=a ₁ /Tg ₁ +a ₂ /Tg ₂ . In the formula, a ₁ and a ₂
each represents a weight fraction. The multilayer structure polymer used in the present invention is usually obtained by a sequential multistage polymerization method using an emulsion polymerization method. When the intermediate layer (C) is made of multiple metals, multistage polymerization may be carried out while gradually decreasing the amount of alkyl acrylate (C ₁ ). When carrying out a sequential multi-stage polymerization method using emulsion polymerization method, a predetermined amount of an emulsifier, a dissolving agent, a monomer, etc. are added to an aqueous solvent and reacted, and after each reaction, the monomers and monomers forming the upper layer are added. By sequentially adding a polymerization initiator to the reaction system, the multilayer structure polymer used in the present invention can be obtained. There are no particular restrictions on the emulsifier, desolvent, etc. used in the production of the multilayer structure polymer, and emulsifiers, desolvents, etc. used in ordinary emulsion polymerization can be used. Typical examples of emulsifiers include anionic surfactants such as long-chain fatty acid salts, sulfonic acid salts, ester salts of sulfosuccinic acid, phosphate ester salts, and acid amide type anionic surfactants. Typical examples of desolators include inorganic peroxides such as potassium persulfate, organic peroxides such as cumene hydroperoxide and lauroyl peroxide, and azo initiators such as azobisisobutyronitrile. However, preferred examples include redox initiators such as cumene hydroperoxide-sodium formaldehyde sulfoxylate. The temperature conditions and polymerization time for polymerization of the multilayer structure polymer depend on the decomposition solvent used, etc., and any conditions are possible as long as the polymerization proceeds smoothly to the final stage. Usually 30-95
The polymerization is carried out within the temperature range of 0.degree. C., and the polymerization time is 3 to 20 hours. Note that it is often preferable to polymerize the crosslinked elastic body portion of the polymer at a relatively low temperature. Furthermore, the method for producing the multilayer structure polymer used in the present invention is not particularly limited to the above method, and may, for example, be an emulsion suspension polymerization method in which after emulsion polymerization, the polymerization of the outermost layer is converted to suspension polymerization. You can get it even if you twist it. Note that there is no particular restriction on the emulsion particle size in the final polymer of the multilayer structure polymer;
The most preferable range is about 800 to 2000 Å. Multilayer polymer latex is processed by salting out by adding additives such as antioxidants, lubricants, coagulants, etc. as necessary, and then filtered, washed with water, dehydrated, and dried to form a powder. It is said to be a polymer with a shape. As explained above, the basic polymer structure of the multilayer structure polymer used in the present invention has the following characteristics. (1) The crosslinked elastic layer has a two-layer elastic structure containing the innermost polymer (A) as an inner layer. (2) The Tg of the crosslinked elastic layer is 0°C or less, and the Tg of the outermost layer is
The temperature was set at 60℃ or higher. (3) The proportion of the crosslinked elastic layer (including the innermost layer) in the polymer is 50% by weight or more. (4) At least one intermediate layer is arranged between the crosslinked elastic layer and the outermost layer in such a manner that the ratio of alkyl acrylate in each layer decreases monotonically from the crosslinked elastic layer to the outermost layer; ) By chemically grafting the layers between each layer using a grafting agent, (6) By ensuring that the gel content of the final polymer is 65% by weight or more, and by satisfying all of these requirements. This is the first time that the multilayer structure polymer used in the present invention can satisfy all the basic characteristics of the multilayer structure polymer, which is extremely flexible and has excellent transparency and weather resistance, and these requirements. If you multiply even just one, you won't get anything satisfactory. In particular, the multilayer structure polymer used in the present invention is characterized in that the crosslinked elastic body is a two-layer removed elastic body containing the innermost layer polymer as an inner layer, and as a result, it maintains excellent weather resistance. It becomes possible to impart excellent elastic properties to the polymer while maintaining the elasticity. In other words, although acrylic rubber generally has superior weather resistance compared to diene rubber, it has slow elastic recovery, large deformation under stress, and low rubber efficiency. There was a limit to imparting elastic properties without increasing the elasticity, but by creating an innermost layer (A) in the core and polydispersively relaxing the stress concentrated in the crosslinked elastic material (B) layer. , further elasticity can be imparted without sacrificing weather resistance. The multilayer structure polymer resin composition of the present invention comprises 99 to 1 part by weight of the multilayer structure polymer [] and a homopolymer of the above-mentioned vinyl halide monomer or vinylidene halide monomer, or a copolymer mainly composed of these monomers. It is manufactured by blending 1 to 99 parts by weight of at least one kind of polymer selected from the following. It is surprising that stress whitening properties are extremely low even in polymer blend systems. This is based on the effect of the special structure of the multilayer polymer, and cannot be predicted from conventional methods of introducing rubber components. In addition, blend compositions containing polyvinylidene fluoride have excellent properties such as weather resistance, transparency, stress whitening resistance, chemical resistance, toughness, and moldability. A resin composition comprising 50 to 90 parts of a multilayer polymer is also an excellent material for film molding, and provides a transparent, tough film with excellent weather resistance, stress whitening resistance, chemical resistance, etc. Such a film can easily impart weather resistance and a design effect by laminating it on the surface of an ordinary molded article, and has extremely high commercial value. The present invention will be specifically explained below using Examples. Note that all parts in the examples are parts by weight. Furthermore, the abbreviations used in the examples are as follows. MMA: Methyl methacrylate BuA: Butyl acrylate BD: 1,3-butylene dimethacrylate AMA: Allyl methacrylate CHP: Cumene hydroperoxide SFS: Sodium formaldehyde sulfoxylate n-OSH: n-octyl mercaptan Example 1 Stirrer, cooler, Into a reaction vessel equipped with a nitrogen gas introduction tube, 250 parts of ion-exchanged water, 2 parts of sulfosuccinic acid ester soda salt, and 0.05 part of SFS were charged.
After stirring under a nitrogen stream, the temperature was raised to 70°C. After that, 9 parts of BuA, 0.6 parts of MMA, 0.4 parts of
A monomer mixture consisting of BD and 0.05 parts of CHP was charged, and the reaction was continued for 60 minutes to complete the polymerization of layer (A). Next, 65 parts of BuA, 0.455 parts of
A monomer mixture consisting of AMA and 0.15 parts of CHP was added over a period of 60 minutes and maintained for an additional 60 minutes to polymerize a crosslinked elastic body consisting of two layers (A) and (B). The crosslinked elastic body thus obtained had a gel content of 94% and a swelling degree of 12. The glass transition temperature (Tg) of layer (B) was -40°C. Next, 3.5 parts of MMA, which corresponds to the middle class,
A monomer mixture consisting of 3.5 parts BuA, 0.07 parts AMA and 0.05 parts CHP was added and polymerized over 30 minutes, and finally 17 parts MMA, 1 part BuA,
An outermost layer polymer (D) consisting of 0.18 parts of n-OSH, CHP, and 0.1 parts was similarly polymerized to obtain a multilayer polymer latex. The Tg of layer (D) was 90°C.
This latex was salted out using 5 parts of calcium chloride, filtered and washed with water, dehydrated and dried to obtain a powdery multilayer polymer. The gel content of the polymer was 88%. 75 parts of this multilayer structure polymer, 25 parts of polyvinylidene fluoride, and 1.5 parts of ultraviolet absorber were mixed, and
It was extruded at 190°C using an extruder with a mm screw, and the pellets were cut into pellets. A film with a thickness of 100 μm was formed from this pellet by the T-die method using the same extruder. It should be noted that from this pellet, it was possible to form a thin film of about 20 μm by changing the film forming conditions. The total light transmittance of the obtained 100 μm thick film is
It was 92.5%, and the haze value was 1.7. Further, the tensile modulus at 20° C. was 1500 Kg/cm ² and the elongation at break was 400% (measured at an elongation rate of 100%/min). Furthermore, this film was laminated onto a commercially available PVC steel plate by a heat-press bonding method, and its weather resistance was evaluated by an accelerated exposure test using a sunshine weather meter. Commercially available PVC steel sheets were considerably discolored after 500 hours, but those laminated with the film obtained from the product of the present invention did not discolor at all even after 2000 hours.

Claims (1)

[Scope of Claims] 1. A multilayer structure polymer resin composition comprising 99 to 1% by weight of the following multilayer structure polymer [] and 1 to 99% by weight of a thermoplastic resin []. Multilayer structure polymer [ ]: (A) 80 to 100 parts by weight of alkyl acrylate having an alkyl group having 1 to 8 carbon atoms and/or alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms (A ₁ ), 0 to 100 parts by weight 20 parts by weight of a monomer having a copolymerizable double bond (A ₂ ), 0 to 10 parts by weight of a polyfunctional monomer (A ₃ ), and the total of (A ₁ ) to (A ₃ ) It consists of a polymer of 0.1 to 5 parts by weight of a grafting agent per 100 parts by weight, and the proportion in the multilayer structure polymer is 5 to 5 parts by weight.
35% by weight of the innermost layer polymer (A); (B) 80 to 100 parts by weight of an alkyl acrylate (B ₁ ) having an alkyl group having 1 to 8 carbon atoms; 0.1 to 100 parts by weight of a monomer having a heavy bond (B ₂ ), 0 to 10 parts by weight of a polyfunctional monomer (B ₃ ), and 100 parts by weight of the total amount of (B ₁ ) to (B ₃ ). A crosslinked elastic polymer (B) consisting of a polymer of 5 parts by weight of a grafting cross-agent, having a glass transition temperature of 0°C or less, and having a proportion of 45 to 80% by weight in the multilayer structure polymer; (C ) 10 to 90 parts by weight of alkyl acrylate (C ₁ ) having an alkyl group having 1 to 8 carbon atoms, 10 to 90 parts by weight of an alkyl methacrylate (C ₂ ) having an alkyl group having 1 to 4 carbon atoms, 0 to 20 Parts by weight of a monomer having a copolymerizable double bond (C ₃ ), 0 to 10 parts by weight of a polyfunctional monomer (C ₄ ), and the total of (C ₁ ) to (C ₄ ) It consists of a polymer containing 0.1 to 5 parts by weight of a grafting agent per 100 parts by weight, and consists of a crosslinked elastic polymer (B) to an outermost layer polymer (D).
one or more layers in which the proportion of alkyl acrylate (C ₁ ) monotonically decreases toward
(D) 51 to 100 parts by weight of alkyl methacrylate (D ₁ ) having an alkyl group having 1 to 4 carbon atoms; 0 to 49 parts by weight of a monomer having a copolymerizable double bond; polymer (D ₂ ), with a glass transition temperature of 60°C or higher, and a proportion of 10 to 40% in the multilayer structure polymer.
% by weight of the outermost layer polymer (D); is successively graft-bonded, and the gel content is 65% by weight or more. Thermoplastic resin [ ]: The following formula: [Chemical formula] (wherein, X and Y each represent H, Cl, Br or F) A homopolymer of a halogenated vinyl monomer or a halogenated vinylidene monomer or a homopolymer thereof At least one type of polymer selected from copolymers whose main component is a monomer.