JPH06122827A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To obtain thermoplastic resin composition composed of a thermoplastic resin and a specific impact modifier at a specific ratio, having excellent weather resistance, surface luster and moldability and useful for molded article, etc. CONSTITUTION:This resin composition is composed of (A) 100 pts.wt. of a thermoplastic resin such as PVC and (B) 3-50 pts.wt. of an impact modifier for thermoplastic resin, consisting of a multilayer graft copolymer composed of monomers selected from monomer groups of alkyl (meth)acrylate, aromatic vinyl compound and vinyl cyanide compound and having at least three layers of (i), (ii) and (iii) each containing 0-5wt.% of a polyfunctional crosslinking agent based on each layer. The glass transition temperature of the polymer constituting the outermost layer (i) is <=0 deg.C, that of the polymer constituting the 2nd layer (ii) from the outermost layer is >=60 deg.C and that of the polymer constituting the 3rd layer (iii) from the outermost layer is <=0 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin composition which can impart high impact resistance and good moldability and has good weather resistance.

[0002]

2. Description of the Related Art Thermoplastic resins, particularly vinyl chloride resins (hereinafter abbreviated as PVC) are widely used as general-purpose resins, but their mechanical properties are not always satisfactory. That is, PVC is inferior in impact strength, particularly impact strength with a notch, and various modifiers have been proposed for the purpose of improving such impact strength.

The most effective method among these proposals is so-called MBS resin in which a conjugated diene elastic body is graft-polymerized with a methacrylic acid alkyl ester and an aromatic vinyl compound, and a conjugated diene elastic body is graft-polymerized with a vinyl cyan compound and an aromatic vinyl compound. It is known to blend the ABS resin with PVC. However, since these MBS resins and ABS resins contain many double bonds in the main chain of the elastic body component, when used outdoors for a long time, they tend to cause a choking phenomenon, a drop in impact strength, etc. and are not suitable for outdoor applications. .

Also proposed is a method of using an elastic body in which a saturated alkyl acrylate is partially replaced by a conjugated diene. In this case, although a high impact strength improving effect is exhibited, it has a drawback that the weather resistance is not so good as that of the MBS resin or the ABS resin.

Further, a resin composition having a good weather resistance is prepared by blending a copolymer obtained by using a saturated polyacrylic acid alkyl ester as an elastic body and graft-polymerizing an alkyl methacrylic acid ester, an aromatic vinyl compound and a vinyl cyan compound with PVC. Have also been proposed.

However, these copolymers show a considerable impact strength-improving effect under well kneading conditions (hereinafter referred to as low-sliding condition) even though they are not as good as MBS resin, but a large amount of lubricant is used. In the case where there is no kneading (hereinafter referred to as a high-sliding condition) such as when it is processed, or when it is processed at a relatively low temperature, almost no effect of improving the impact strength is exhibited.

[0007]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention As a result of intensive investigations made by the present inventors in view of the present situation, it is found that evenly dispersing a multi-layer graft copolymer using an alkyl acrylate elastomer in PVC has impact strength developing properties. It is known that the glass transition temperature of the outermost layer (hereinafter, referred to as "the outermost layer") is more surprising than that of the multi-layered graft copolymer in which a resin component having good compatibility with PVC is graft-polymerized to an elastic body, which is surprisingly well known. Abbreviated as Tg) is 0 ° C. or less, the second layer from the outermost layer has a Tg of 60 ° C. or more, and the third layer from the outermost layer has a Tg of 0 ° C. or less. Even when the multi-layer graft copolymer has a high sliding condition and a low shear stress, the multi-layer graft copolymer is easily melted quickly, the PVC resin composition is gelled quickly, and the dispersed state is very good. In addition, it was found that such a PVC resin composition can exhibit high impact strength under a wide range of molding conditions, has good processability, excellent surface gloss, and good weather resistance. The present invention has been reached.

[0008]

The present invention provides a thermoplastic resin 1
Of the polymer constituting the outermost layer (A), which is composed of 100 parts by weight of a monomer selected from the group consisting of acrylic acid alkyl ester, methacrylic acid alkyl ester, aromatic vinyl compound and vinyl cyan compound. The glass transition temperature is 0 ° C. or lower, the glass transition temperature of the polymer forming the second layer (B) from the outermost layer (A) is 60 ° C. or higher, and the third layer (C) from the outermost layer (A) is formed. (A), (B) and (C) in which the glass transition temperature of the polymer to be used is 0 ° C. or lower
Impact resistance for thermoplastic resin having a multilayer structure consisting of at least three layers and comprising a multi-layer graft copolymer containing 0 to 5% by weight of a polyfunctional crosslinking agent for each layer in each layer A thermoplastic resin composition comprising 3 to 50 parts by weight of a property modifier and having good weather resistance, impact resistance and moldability.

It is essential for the impact modifier of the present invention to have a multi-layer structure of three or more layers obtained by polymerizing at least three stages, and the fourth layer counted from the outermost layer is the sole layer. A four-layer graft copolymer composed of a polymer having a Tg of 60 ° C. or higher, but the fifth layer counted from the outermost layer has a homopolymer Tg of 0 ° C. or lower. It may be a multi-layered graft copolymer such as a five-layered graft copolymer, and in such a case, the impact resistance improving effect is similarly exhibited.

The group of monomers constituting the impact modifier of the present invention is composed of alkyl acrylate, alkyl methacrylate, aromatic vinyl compounds and vinyl cyan compounds.

The alkyl acrylate is preferably one having an alkyl group having 2 to 10 carbon atoms, for example, ethyl acrylate, propyl acrylate, acrylic acid n.
-Butyl, isobutyl acrylate, hexyl acrylate, octyl acrylate, 2-ethyl-hexyl acrylate and the like.

As the methacrylic acid alkyl ester,
An alkyl group having 1 to 4 carbon atoms is preferable, and examples thereof include methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, and tert-butyl methacrylate. . Methyl methacrylate is particularly preferable in consideration of compatibility with PVC.

Examples of the aromatic vinyl compound include styrene, α-substituted styrene, each substituted styrene and its derivative such as α-methylstyrene, chlorostyrene, vinyltoluene and the like.

Furthermore, examples of the vinyl cyan compound include acrylonitrile and methacrylonitrile.

The component of the outermost layer (A) constituting the impact modifier of the present invention is selected from the above monomer group so that the Tg of the outermost layer (A) itself is 0 ° C. or lower. Outermost layer (A)
The composition ratio of the monomer in the acrylic acid alkyl ester is 60 to 100% by weight, methacrylic acid alkyl ester is 0 to 40% by weight, aromatic vinyl compound is 0 to 40% by weight, and vinylcyanide compound is 0 to 20% by weight. It can be used in a range. When the Tg of the outermost layer (A) itself exceeds 0 ° C, the final modifier obtained is blended with PVC and molded, and the (A) layer portion melts slowly, resulting in a desired impact resistance improving effect. Is difficult to obtain.

The proportion of the outermost layer (A) in the total amount of the multi-layer graft copolymer is preferably 10 to 50% by weight, and the proportion of less than 10% by weight has a small effect of improving impact resistance.
A proportion of more than 0% by weight is not preferable because the moldability when blending with PVC and molding becomes poor.

The components of the outermost layer (A) to the second layer (B) are selected from the above monomer group so that the Tg of the layer (B) itself is 60 ° C. or higher. The composition ratio of the monomer in the layer (B) is 0 to 10 methacrylic acid alkyl ester.
It can be used in the range of 0% by weight, 0 to 100% by weight of aromatic vinyl compound, 0 to 30% by weight of vinylcyanide compound, and 0 to 20% by weight of alkyl acrylate. When the Tg of the layer (B) itself is less than 60 ° C, it is difficult to obtain a multilayer graft polymer as a good powder. As the component of the layer (B),
When blended with PVC, alkyl methacrylate is preferable, and methyl methacrylate is particularly preferable. An aromatic vinyl compound improves its fluidity during blend molding with PVC, but when used in a large amount, its compatibility deteriorates and its impact resistance decreases. A vinyl cyan compound is preferable because it promotes gelation at the time of blending with PVC, but when used in a large amount, it tends to give a coloration at the time of molding and also deteriorates processability.

The proportion of the layer (B) in the total amount of the multilayer graft copolymer is preferably 20 to 60% by weight, and 20% by weight.
If it is less than the above range, the molding processability at the time of blending with PVC and molding is inferior, which is not preferable. On the other hand, if the proportion exceeds 60% by weight, the amount of the elastic material component in the whole multilayer graft copolymer is reduced, and the impact resistance improving effect is small, which is not preferable.

Further, the third layer (C) from the outermost layer (A)
The component (1) is selected from the monomer group so that the Tg of the layer (C) itself is 0 ° C. or lower. The composition ratio of the monomer in the layer (C) is 60 to 10 of alkyl acrylate.
It can be used in the range of 0% by weight, 0 to 40% by weight of methacrylic acid alkyl ester, 0 to 40% by weight of aromatic vinyl compound, and 0 to 20% by weight of vinyl cyan compound. When the Tg of the layer (C) itself exceeds 0 ° C., the elastic properties of the layer (C) itself are impaired, and it is difficult to obtain the desired impact resistance improving effect.

The proportion of the layer (C) in the total amount of the multilayer graft copolymer is preferably 10 to 60% by weight, and 10% by weight.
If it is less than 60% by weight, the impact resistance improving effect is small, and if it exceeds 60% by weight, the molding processability at the time of blending with PVC and molding is inferior.

The polyfunctional crosslinking agent of the present invention not only facilitates the graft cross-linking in producing the impact modifier of the present invention, but also significantly improves the coagulability of the emulsion polymer latex. It is a thing. As the polyfunctional crosslinking agent, divinylbenzene, diacrylic acid ester or dimethacrylic acid ester which is an ester of polyhydric alcohol with acrylic acid or methacrylic acid, or triallyl cyanurate, triallyl isocyanurate, allyl acrylate, allyl methacrylate. , Diallyl itaconate, diallyl phthalate and the like. From the viewpoint of graft crossing property, a cross-linking agent having an allyl group is preferable.

The proportion of the polyfunctional crosslinking agent in each layer is 0.
~ 5% by weight. When it is used in an amount of more than 5% by weight, the outermost layer (A) or layer (C) which is an elastic layer too impairs the elastic properties. Further, since the compatibility of the resin layer (B) with PVC is deteriorated, the effect of improving impact resistance is reduced, which is not preferable. The proportion of the polyfunctional crosslinking agent in each layer is 0.1 to 0.1 in consideration of the coagulability of the emulsion polymer latex during the production of the multilayer graft copolymer and the impact resistance improving effect of the resulting multilayer graft copolymer. 3% by weight
Is more preferable.

The multi-layer graft copolymer as the impact modifier of the present invention is preferably produced by a usual emulsion polymerization method.

Examples of the emulsifier include anionic surfactants such as fatty acid salts, alkyl sulfate ester salts, alkylbenzene sulfonates, alkyl phosphate ester salts, dialkylsulfosuccinates, polyoxyethylene alkyl ethers and polyoxyethylene. Nonionic surfactants such as fatty acid esters, sorbitan fatty acid esters, and glycerin fatty acid esters, and cationic surfactants such as alkylamine salts can be used. These surfactants can be used alone or in combination. Further, depending on the kind of the emulsifier, when the pH of the polymerization system is on the alkaline side, an appropriate pH adjusting agent can be used in order to prevent the hydrolysis of the alkyl acrylate.

As the polymerization initiator, an ordinary inorganic initiator such as a persulfate salt, an organic peroxide, an azo compound or the like may be used alone, or the above compound and a sulfite salt, a hydrogen sulfite salt, a thiosulfate salt, It can also be used as a redox initiator by combining with a first metal salt, sodium formaldehyde sulfoxylate, and the like. Preferred persulfates as the initiator are sodium persulfate, potassium persulfate, ammonium persulfate and the like, and the organic peroxide is t
-Butyl hydroperoxide, cumene hydroperoxide, benzoyl peroxide, lauroyl peroxide and the like.

A chain transfer agent may be used to control the molecular weight of the polymer, and alkyl mercaptan having 5 to 20 carbon atoms can be used.

Polymerization is carried out at a temperature above the decomposition temperature of the initiator,
Under normal emulsion polymerization conditions, at least the outermost layer (A), the second outermost layer (A) to the second layer (B) and the outermost layer (A) to 3
This can be done so that the second layer (C) has the structure as described above. At this time, the polymerization in each of the steps can be carried out while adding the whole amount of each monomer or a mixture of the monomers at once, or continuously adding the whole amount or a part thereof. However, from the viewpoints of stability of polymerization, removal of heat of polymerization reaction, etc., it is preferable to carry out the polymerization while adding the whole amount or a part thereof.

The particle size of the multilayer graft copolymer is PVC
It greatly affects the impact strength of the resin composition. If the particle size is too small, the impact strength improving effect is small, and it is preferable that the particle size is as large as possible without impairing the stability of the latex.
The particle size of the graft copolymer is preferably in the range of 0.15 to 0.40μ, and is adjusted with an appropriate emulsifier type and amount, or with an enlargement agent such as an acid or an inorganic salt at an appropriate polymerization stage. You can also do it.

When recovering the multi-layered graft copolymer from the latex thus obtained, it may be recovered by salting out or acidifying and coagulating, filtering and washing and then collecting in powder form, or by spray drying, freeze drying and the like. it can. further,
It can also be recovered by the method described in JP-A-57-187322.

The impact modifier of the present invention is a graft copolymer having the above-mentioned multi-layer structure and imparts high impact resistance and good processability to various thermoplastic resins, and molded articles. It is also a modifier having good weather resistance.

The proportion of the impact modifier of the present invention incorporated into the thermoplastic resin is 3 to 5 relative to 100 parts by weight of the thermoplastic resin.
0 parts by weight. If the compounding ratio is less than 3 parts by weight, the impact resistance improving effect is small, and if it exceeds 50 parts by weight, the mechanical properties inherent in the thermoplastic resin are impaired, which is not preferable. Here, the thermoplastic resin is PVC,
Examples thereof include polycarbonate resin, polyester resin, acrylonitrile-styrene resin, and methyl methacrylate-styrene resin. As PVC, in addition to polyvinyl chloride, a vinyl chloride-based copolymer containing 70% by weight or more of vinyl chloride can be used. As the monomer to be copolymerized with vinyl chloride, ethylene, propylene, vinyl bromide, vinylidene chloride, vinyl acetate, acrylic acid ester, methacrylic acid ester and the like are used.

The impact modifier of the present invention and the thermoplastic resin are preferably compounded in a powder form, for example, by a ribbon blender, a Henschel mixer, etc., and a known kneader,
For example, it is molded by a mixing roll, a Banbury mixer, an extruder, an injection molding machine and the like. When blending, known stabilizers, plasticizers, lubricants, colorants and the like may be added as necessary.

[0033]

The present invention will be described in detail with reference to the following examples. In the examples, "part" and "%" are "part by weight",
It means "% by weight".

Further, the T of the copolymer in each Example and Comparative Example
g is obtained from the Fox equation.

Example 1 (a) Production of Multilayer Graft Copolymer 190 parts of nitrogen-exchanged deionized water was placed in a reaction vessel,
While dissolving 1.2 parts of semi-cured beef tallow fatty acid soap and 0.6 part of potassium persulfate and maintaining the temperature at 70 ° C., n-butyl acrylate 19.85 parts and triallyl isocyanurate 0. A mixture of 15 parts was added dropwise over 1 hour. After completion of the dropping, the temperature was maintained for 1 hour while maintaining the same temperature to complete the polymerization. The polymerization rate was 99.0%.

A mixture of 49.7 parts of methyl methacrylate and 0.3 part of triallyl isocyanurate as a layer (B) component was added to this polymer latex for 2 hours.
The temperature was kept at 70 ° C., and the mixture was added dropwise, and after completion of the addition, the mixture was kept for 1 hour to complete the polymerization. The polymerization rate was 99.5%.

0.2 part of potassium persulfate was dissolved in 10 parts of water and added to the obtained polymer latex, and 29.8 parts of n-butyl acrylate as a component of layer (A) and triallyl isocyanurate of 0. The mixture of 2 parts was added dropwise over 90 minutes while maintaining the temperature at 70 ° C., and after completion of the addition, the mixture was maintained for 1 hour to complete the polymerization. The polymerization rate was 99.3%, and the average particle size of the obtained graft copolymer was 0.25 μ.

The resulting multi-layered graft copolymer latex was added to an aqueous sulfuric acid solution, coagulated by acid precipitation, washed, dehydrated and dried to recover the graft copolymer in powder form (Example 1-1)). .

Further, the composition ratios of the layer (C), the layer (B) and the layer (A) were variously changed to obtain a multi-layer graft copolymer obtained by the same polymerization formulation as described above. These are shown in Table 1.

(B) Production of compounding composition with vinyl chloride resin Each multilayer graft copolymer 13 obtained in the above (a)
And a total of 87 parts of vinyl chloride resin having an average degree of polymerization of 700
Dibutyltin malate (2.5 parts), butyl stearate (0.8 parts) and lubricant (0.7 parts) were added to 0 parts, and the mixture was heated to 115 ° C. in a Henschel mixer to obtain a uniform mixture. The vinyl chloride resin composition was kneaded with a mixing roll adjusted to 175 ° C. for 3 minutes, and the obtained sheet was hot-pressed to prepare a test piece, and its impact strength was measured. The Izod impact test with a V notch was performed for the impact strength according to ASTM-D256. Compounding conditions of this vinyl chloride resin composition,
The molding condition is a low slip condition.

Further, 13 parts of each multilayer graft copolymer obtained in the above (a) and 87 parts of vinyl chloride resin having an average degree of polymerization of 700 are added to 100 parts in total, 2.0 parts of tribasic lead sulfate and dibasic stearin. 0.3 part lead acid, 2.0 lead stearate
And 0.3 part of stearic acid were added and the temperature was raised to 115 ° C. in a Henschel mixer to obtain a uniform mixture. This vinyl chloride resin composition was formed into a square rod under the following conditions with a 30 mmφ single screw extruder.

Cylinder 1 150 ° C. Cylinder 2 165 ° C. Cylinder 3 180 ° C. Die 200 ° C. Screw CR = 3.0, 30 mmφ full flight screw The impact strength of the molded product is 2 mm deep except that a U-notched sample is used. It was measured according to ASTM-D-256.
The compounding conditions and molding conditions of this vinyl chloride resin composition are high lubricity conditions.

The results of these measurements are also shown in Table 1.

Table 1 also shows the impact strength of the vinyl chloride resin itself under high-sliding condition and low-sliding condition.

Comparative Example 1 190 parts of ion-exchanged water which had been replaced with nitrogen were placed in a reaction vessel,
A mixture of 1.2 parts of semi-cured tallow fatty acid soap and 0.4 parts of potassium persulfate was dissolved in 59.7 parts of n-butyl acrylate and 0.3 parts of triallyl isocyanurate while maintaining at 70 ° C. Dropped over time. After the completion of the dropping, the temperature was maintained for 1 hour to maintain the same temperature to complete the polymerization. The polymerization rate was 99.5%.

0.2% potassium persulfate was added to this polymer latex.
Parts dissolved in 10 parts water and added, methyl methacrylate 3
A mixture of 9.8 parts and 0.2 part of triallyl isocyanurate was added dropwise over 2 hours while maintaining the temperature at 70 ° C. After the completion of the dropping, the temperature was kept for 1 hour to keep the temperature the same to complete the polymerization. The polymerization rate was 99.7%. The average particle diameter of the graft polymer was 0.23μ.

A graft copolymer was recovered from this graft polymer latex in the same manner as in Example 1.

This graft copolymer was used in Example 1 (b).
The composition blended by the same formulation was measured for impact strength under the same high slip condition and low slip condition. The results are shown in Table 2.

Comparative Example 2 In Comparative Example 1, the first stage potassium persulfate was changed to 0.2 parts, and a mixture of 39.8 parts of methyl methacrylate and 0.2 parts of triallyl isocyanurate was similarly polymerized. Let

Further, 0.4 parts of potassium persulfate dissolved in 10 parts of water was added to the polymer latex to add acrylic acid n-
Butyl 59.7 parts, triallyl isocyanurate 0.3
Polymerization was completed in the same manner as in Comparative Example 1 using the mixture of parts, and the graft copolymer was recovered.

This graft copolymer was used in Example 1 (b).
The composition blended by the same formulation was measured for impact strength under the same high slip condition and low slip condition. The results are also shown in Table 2.

As is clear from the results shown in Tables 1 and 2, the impact modifier of the present invention exhibits a high effect of improving impact resistance, especially under high slip conditions.

[0053]

[Table 1]

[0054]

[Table 2]

The abbreviations in Tables 1 and 2 are as follows, and the same applies to the subsequent cases.

BA: n-butyl acrylate MMA: methyl methacrylate TAIC: triallyl isocyanurate Example 2, Comparative Examples 3 to 4 Layer (C) Component, Layer (B) Component and Layer (A) Component Monomer A multilayer graft copolymer obtained by the same operation as in Example 1 except that the types of the polymer and the cross-linking agent and the number of parts used are changed as shown in Table 3 was obtained in the same manner as in Example 1 (b). The impact strength was measured at. The results are shown in Table 3.

[0057]

[Table 3]

The abbreviations in Table 3 are as follows, and the same applies to the subsequent cases.

2EHA: 2 Ethyl-hexyl acrylate St: Styrene AN: Acrylonitrile AMA: Allyl methacrylate As can be seen from Comparative Examples 3 and 4, the layer (C) component or the layer (A) component having a high Tg is impact resistant. It can be seen that the effect of improving the sex is small.

Example 3 180 parts of ion-exchanged water substituted with nitrogen was placed in a reaction vessel,
1.4 parts of sodium lauroylbenzene sulfonate,
Sodium formaldehyde sulfoxylate 0.35
While maintaining the temperature at 70 ° C., a mixture of 29.8 parts of n-octyl acrylate, 0.2 part of triallyl cyanurate and 0.15 part of cumene hydroperoxide as a component of the layer (C) is dissolved for 1 hour. Dropwise over 30 minutes. After the completion of the dropping, the temperature was maintained for 1 hour to maintain the same temperature to complete the polymerization.

To this polymer latex, 34.7 parts of methyl methacrylate and 5 parts of acrylonitrile as the component (B) were added.
Part, 0.3 parts of triallyl cyanurate and 0.2 part of cumene hydroperoxide were added dropwise over 2 hours while maintaining the temperature at 70 ° C. After completion of dropping, the mixture was kept for 1 hour to complete the polymerization.

To the obtained polymer latex, 0.6 part of sodium lauroylbenzenesulfonate and 0.15 part of sodium formaldehyde sulfoxylate were dissolved in 20 parts of water and added, and acrylic acid n- was added as the layer (A) component.
Octyl 29.8 parts, triallyl cyanurate 0.2
Part and cumene hydroperoxide (0.15 part) were added dropwise over 1 hour and 30 minutes while maintaining the temperature at 70 ° C. After the dropping, hold for 1 hour while keeping the same temperature,
The polymerization was completed. The average particle size of the obtained graft copolymer was 0.22μ.

A graft copolymer was recovered from the obtained multi-layered graft copolymer latex in the same manner as in Example 1 (a), and a PVC resin composition was obtained in the same manner as in Example 1 (b). . The impact strength of this was measured in the same manner as in Example 1 (b). The results are shown in Table 4.

Table 4 also shows the results when the composition ratios of the layer (C), the layer (B) and the layer (A) were changed.

[0065]

[Table 4]

The abbreviations in Table 4 are as follows.

OA: n-octyl acrylate TAC: triallyl cyanurate As shown in Table 4, when the amount of the crosslinking agent in each component is large, the impact resistance improving effect is small.

Example 4 A commercially available PVC resin modifier, methyl methacrylate-butadiene-styrene resin (MBS resin) and chlorinated polyethylene (ClPE) were prepared under the high lubricity condition of Example 1 (b). PVC resin composition and Example 1 of the present invention
Example 1 using the multilayer graft copolymer obtained in (a)
Table 5 shows the weather resistance of the PVC resin composition under the condition (b) of high lubricity. The weather resistance is shown by the Izod impact strength and the degree of coloring after accelerated exposure treatment with a weatherometer (WE-II type manufactured by Toyo Rika).

[0069]

[Table 5]

The indication of the degree of coloring in Table 5 is as follows.

◯: Almost no coloration and good. Δ: Slightly colored, which is not very preferable. X: Colored and defective.

From the results shown in Table 5, it is understood that the modifier according to the present invention has very good weather resistance (initial impact retention rate, coloration) as compared with commercially available MBS and ClPE.

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Claims (3)

[Claims] 1. A thermoplastic resin of 100 parts by weight, an acrylic acid alkyl ester, a methacrylic acid alkyl ester,
Outermost layer (A) composed of a monomer selected from the group consisting of aromatic vinyl compounds and vinyl cyan compounds
The glass transition temperature of the polymer constituting the polymer is 0 ° C. or lower, the glass transition temperature of the polymer constituting the second layer (B) from the outermost layer (A) is 60 ° C. or higher, and the third layer from the outermost layer (A) is The polymer constituting the layer (C) has a glass transition temperature of 0 ° C. or lower and has a multi-layer structure consisting of at least three layers of the layers (A), (B) and (C), and each layer has a multi-layer structure. Of a multi-layered graft copolymer containing 0 to 5% by weight of a multifunctional cross-linking agent, and a weather resistance, impact resistance and impact resistance modifier of 3 to 50 parts by weight having good weather resistance. A thermoplastic resin composition having good molding processability. 2. The outermost layer (A) of the impact modifier for a thermoplastic resin according to claim 1, wherein the polymer constituting the layer (A) from the monomer group has a glass transition temperature of 0. 95 to 100% by weight of at least one monomer selected so as to be below ℃
And a multifunctional cross-linking agent in an amount of 0 to 5% by weight, and the proportion in the multilayer graft copolymer is 10 to 50% by weight, and the outermost layer (A) to the second layer (B) are: 95-100% by weight of at least one monomer selected so that the glass transition temperature of the polymer constituting the layer (B) from the monomer group is 60 ° C. or higher, and the polyfunctional crosslinking agent 0- 5% by weight of the polymer, and the proportion in the multilayer graft copolymer is 20 to 60% by weight, and the third layer (C) from the outermost layer (A) is a layer from the monomer group. A polymer comprising 95 to 100% by weight of at least one monomer selected so that the glass transition temperature of the polymer constituting (C) is 0 ° C. or lower, and 0 to 5% by weight of a polyfunctional crosslinking agent. And the proportion in the multilayer graft copolymer is 10 to 60% by weight. Claim 1 Thermoplastic resin composition. 3. The thermoplastic resin composition according to claim 1, wherein the thermoplastic resin mixed with the impact modifier for thermoplastic resin according to claim 1 is a vinyl chloride resin.