JP2767041B2 - Impact resistant resin composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a resin composition having good weather resistance and excellent impact resistance.

[Conventional technology]

Conventionally, acrylonitrile-butadiene-styrene copolymer (ABS resin), high impact polystyrene (HIPS), impact resistant methacrylic resin and the like have been widely used as impact resistant thermoplastic resins. These include thermoplastic resins such as acrylonitrile-styrene copolymer (AS resin), polystyrene, styrene methacrylate-styrene copolymer (MS resin), methacrylic resin, and polybutadiene rubber such as polybutadiene or butadiene-styrene copolymer. And exhibits excellent impact resistance.

In recent years, the above resin compositions have been widely used mainly in the field of vehicles. Particularly in the case of a vehicle, a material having weather resistance, impact resistance, and heat deformation resistance is often required.

By the way, polybutadiene-based rubber has poor stability to ultraviolet rays due to unsaturated bonds in the molecule, and remarkably deteriorates appearance. Thus, as a method of imparting impact resistance while maintaining weather resistance, a method of blending an acrylic rubber such as a polyacrylic acid alkyl ester or an alkyl acrylate-styrene copolymer with a thermoplastic resin has been performed. .

[Problems to be solved by the invention]

However, in the above method of compounding an acrylic rubber, the effect of improving impact resistance is smaller than in the case of compounding a butadiene rubber, and in order to obtain a desired impact strength, a large amount of a rubber component must be compounded. As a result, the properties of the resin such as heat deformation resistance, scratch resistance, rigidity, etc., are impaired.

[Means for solving the problem]

Therefore, the present inventors have added the excellent weather resistance, heat deformation resistance, and abrasion resistance of a conventional thermoplastic resin, particularly to the transparent resin in addition to the above-mentioned properties, and without sacrificing the excellent transparency. As a result of intensive studies to obtain a resin composition having excellent impact resistance, the present invention has been achieved.

The gist of the present invention is that the thermoplastic resin (I) 97
A crosslinked rubbery polymer having an average particle diameter of 0.05 to 1 μm containing at least one selected from an aromatic vinyl compound and an alkyl (meth) acrylate in an amount of from 50 to 50 parts by weight and an alkyl acrylate as a structural unit With respect to 100 parts by weight of the total amount of 3 to 50 parts by weight of the graft copolymer (II) obtained by graft-polymerizing the monomer mixture containing
The following general formula (Wherein, R ₁ represents hydrogen or a methyl group, and R ₂ represents an aliphatic or alicyclic hydrocarbon group or an arylalkyl group.) 10-90% by weight of a (meth) acrylic acid alkyl ester (a) And the following general formula (Wherein, R ₃ is hydrogen or a methyl group, l and n are each 0 to 2
M is 0 or 1, R ₄ is an alkyl group or a phenyl group, and x is an integer of 1 to 100. (B) 90 to 10% by weight of a copolymer (III) and 0.001 to 5 parts by weight of a radically polymerizable silicone macromer (b).

Hereinafter, the impact-resistant resin composition of the present invention will be described in detail.

The thermoplastic resin (I) used in the present invention may be any resin that is hard at room temperature, but may be a methyl methacrylate polymer, a methyl methacrylate-styrene copolymer, or a methyl methacrylate-acrylonitrile-styrene copolymer. Copolymer, methyl methacrylate-N-substituted maleimide copolymer, N-substituted dimethylglutarimide-containing methyl methacrylate-based polymer, methyl methacrylate-α-methylstyrene-styrene-maleic anhydride copolymer, methyl methacrylate- α-methylstyrene-styrene-N-substituted maleic acid copolymer, styrene-based polymer, acrylonitrile-styrene copolymer, acrylonitrile-styrene-N-substituted maleimide copolymer, and polycarbonate are preferred. In particular, the effect is large for a copolymer containing methyl methacrylate as a main component.

Next, the graft copolymer (II) has an average particle diameter of 0.05 to 1 μm containing an alkyl acrylate as a constituent unit.
m, a crosslinked rubbery polymer and an aromatic vinyl compound
At least one selected from alkyl acrylates
It is obtained by graft-polymerizing a monomer mixture containing a seed as a constituent unit.

Examples of the alkyl acrylate constituting the crosslinked rubbery polymer include methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate,
And cyclohexyl acrylate. Other copolymerizable monomers include aromatic vinyl monomers such as styrene and α-methylstyrene, aliphatic monomers such as ethylene, propylene and butylene, methyl methacrylate, phenyl methacrylate, and benzyl methacrylate. And the like, methacrylic acid esters, acrylonitrile, methacrylonitrile and the like.

The crosslinked rubber-like polymer is preferably in the range of 0.05 to 1 μm in consideration of the impact strength and the appearance after molding, and 0.05 μm.
m, the effect of modifying the impact strength is not exhibited.
If it exceeds m, the appearance of the molded plate, particularly gloss, is impaired, which is not preferred.

Further, the glass transition temperature of the crosslinked rubbery polymer is preferably 25 ° C. or lower, particularly preferably 0 ° C. or lower.
When the temperature exceeds 25 ° C., the physical properties of the elastomer are not exhibited, which is not preferable.

Next, styrene, α-methylstyrene, and the like are used as the aromatic vinyl compound as the graft component, and methyl methacrylate, methyl acrylate, ethyl acrylate, n-butyl acrylate, and acryl are used as the alkyl (meth) acrylate. Phenyl acid, cyclohexyl acrylate, and the like. Examples of other copolymerizable monomers include acrylonitrile, methacrylonitrile, N-substituted maleimide, and N-substituted glutarimide.

As the graft copolymer (II), those produced by a known polymerization method can be used.

The usage ratio of the thermoplastic resin (I) and the graft copolymer (II) is in the range of 3 to 50 parts by weight of the graft copolymer (II) based on 97 to 50 parts by weight of the thermoplastic resin (I). If the amount of the graft copolymer (II) used is less than 3 parts by weight, the effect of exhibiting impact resistance is poor, while if it exceeds 50 parts by weight, heat resistance and rigidity tend to be poor.

Further, the copolymer (II) which is an important component of the present invention
I) is the following general formula (Wherein, R ₁ represents hydrogen or a methyl group, and R ₂ represents an aliphatic or alicyclic hydrocarbon group or an arylalkyl group.) 10-90% by weight of a (meth) acrylic acid alkyl ester (a) And the following general formula (Wherein, R ₃ is hydrogen or a methyl group, l and n are each 0 to 2
M represents 0 or 1, R ₄ represents an alkyl group or a phenyl group, and x represents an integer of 1 to 100. ) Is a copolymer comprising 90 to 10% by weight of a radical polymerizable silicone macromer (b).

As the alkyl (meth) acrylate, R _{2 in} the formula is an aliphatic hydrocarbon group such as methyl, ethyl, propyl, butyl, amyl, hexyl, stearyl, an alicyclic hydrocarbon group such as cyclopentyl or cyclohexyl, or benzyl. , Cinnamyl and the like.

Further, as the radical polymerizable silicone macromer (b), the effect of silicone as a copolymer (III),
That is, when considering impact resistance, water repellency, oil repellency, etc.,
It is effective that the degree of polymerization x of the silicone part is 1 to 100, and especially 1
A range from 0 to 50 is preferred. In the formula, R ₄ represents an alkyl group such as methyl, ethyl, propyl or the like or a phenyl group, such as those shown below.

The copolymer (III) of the present invention contains, as an active ingredient, an addition copolymer with one or two or more of the alkyl (meth) acrylate (a) and the radically polymerizable silicone macromer (b). It is a thing. In order to obtain such a copolymer (III), a method of dissolving the raw material monomer in an appropriate organic solvent and performing solution polymerization with a polymerization initiator is usually adopted. Suitable solvents for solution polymerization are ethyl acetate, butyl acetate, methyl ethyl ketone, toluene, ethylbenzene and the like. Other various types and conditions of the non-aqueous polymerization reaction and the method of the aqueous emulsion polymerization can be arbitrarily selected, and examples thereof include bulk polymerization and radiation polymerization. The average molecular weight of the copolymer oligomer thus obtained is usually 10,000 to 100,000
May be employed.

The copolymer (III) of the present invention is dispersed in water,
Alternatively, those dissolved in an organic solvent can be used.

Further, as the copolymer (III) of the present invention, "LSI-60"
Commercial products such as (product of Soken Chemical Co., Ltd.) and "Aron GS-30" (product of Toa Gosei Chemical Co., Ltd.) can be used.

The amount of the copolymer (III) is 0.001 to 0.001 parts by weight based on 100 parts by weight of the total amount of the thermoplastic resin (I) and the graft copolymer (II).
5 parts by weight. If the amount is less than 0.001 part by weight, the effect of improving the impact resistance is not seen, while if it exceeds 5 parts by weight, the effect is saturated and does not increase, and the heat resistance tends to decrease.

In the impact-resistant resin composition of the present invention, the thermoplastic resin (I) and the graft copolymer (II) and the copolymer (III)
As a method of blending and mixing thermoplastic resin (I),
Graft copolymer (II) and copolymer (III),
Alternatively, a mixture of a thermoplastic hard resin (I) and a graft copolymer (II) and a copolymer (III) are mixed with a Hensiel mixer or a V-type tumbler, and then mixed with a screw extruder or a mixing roll. And a method of melting and mixing at 150 to 300 ° C. In addition, at the time of melt mixing, a stabilizer, a lubricant, a plasticizer, a dye / pigment, a filler, and the like can be appropriately added, if necessary, in addition to the above-mentioned respective resin composition components.

By forming the thermoplastic resin composition obtained as described above using an extrusion molding machine, an injection molding machine, or the like, the weather resistance is good, and the impact resistance is excellent, and particularly, the transparency of the transparent resin is improved. A molded article that is not hindered can be obtained.

〔Example〕

 Hereinafter, the present invention will be described in more detail with reference to examples.

In the examples, "parts" means "parts by weight",
“%” Represents “% by weight”, respectively.

 The evaluation of the physical properties in the examples was performed by the following methods.

(1) The heat distortion temperature (° C.) was measured according to ASTM-D-6481.

(2) Izod impact strength (kg-cm / cm ² ) is ASTM-D
Measured according to -256.

(3) Total light transmittance (%) and haze (%) are as
It measured according to D-1003-52.

The following was used as the thermoplastic resin (I) in the examples.

MMA resin: The viscosity (η) measured in chloroform at 25 ° C. and the ratio (part) of methyl methacrylate to methyl acrylate is 97: 3, and the viscosity [η] is 0.056 (/ g). Graft copolymer (II) is obtained by the following method. The one manufactured was used.

(1) Production of graft copolymer (II-1) (1-1) Production of first step (a) First, the following raw materials (a) and (b) are placed in a stainless steel reaction vessel having an inner volume of 50. Was charged, and nitrogen was blown under stirring to make the state substantially free from the influence of oxygen. Then, the temperature was raised to 65 ° C, the following raw materials (C) were added, and the temperature was further raised to 80 ° C for polymerization for 90 minutes. Continued. Then again (b) raw material
5 kg was continuously added over 90 minutes, and polymerization was further performed for 120 minutes to obtain an acrylic latex.

(A) Raw material Deionized water 30 kg sarcosinate LN (S-LN) ^{* 1)} 100 g boric acid 100 g sodium carbonate 10 g * 1) N-acyl sarcosic acid salt (manufactured by Nikko Chemicals Co., Ltd.) (b) Raw material Butyl acrylate (BA) (80%) 4 kg Styrene (ST) (19%) 950 g Acrylic methacrylate (AMA) (1%) 50 g Cumene hydroperoxide (CHP) 15 g (C) Raw material Deionized water 500 g Didium formaldehyde sulfoxylate (hereinafter, referred to as
Rongalit) 50 g In this polymerization, the degree of polymerization of BA was 98%, and the degree of polymerization of ST was 99%. As a result of measurement by an absorbance method, the particle size of the obtained latex was 0.08 μm.

(1-2) Production of the second step (b) In the same reaction vessel in which the latex containing 10 kg (100 parts) of the solid component of the first step (a) is present, (d) raw material deionized water 500 g S- After 25 g of LN was added and stirred, 80 parts of the following raw material (e) was continuously added at a rate of 40 parts / hour while maintaining the temperature at 80 ° C.
Thereafter, polymerization was continued for another hour. Then, the graft copolymer (II-1) was obtained in the form of a latex. The polymerization rate of the monomer of the raw material (e) was 99.5% or more.

(E) Raw materials Methyl methacrylate (MMA) (96.0%) 7680 g Ethyl acrylate (EA) (4%) 320 g Normal octyl mercaptan 28 g CHP 24 g This latex is coagulated, washed and dried by the methods described below to form a multi-layer A rubber component powder was obtained.

50 kg of 1.0% sulfuric acid aqueous solution is charged into a stainless steel container, the temperature is raised to 85 ° C. with stirring, 25 kg of the latex previously produced is continuously added over 15 minutes, and then the internal temperature is raised to 90 ° C. for 5 minutes. Held. After cooling to room temperature, the polymer was separated and washed with deionized water to obtain a white creamy polymer, which was dried at 70 ° C for 36 hours to obtain a white powdery polymer.

(2) Production of graft copolymer (II-2) (2-1) Production of first step (c) First, the following raw material (f) was added into a stainless steel reaction vessel having an inner volume of 50, Nitrogen was blown in under stirring to make the state substantially free from the influence of oxygen, and then the temperature was raised to 70 ° C., and the following raw material (g) was added, followed by polymerization for 2 hours to obtain a latex of a hard crosslinked resin body. .

(F) Raw material Deionized water 20 kg S-LN 16 g Boric acid 80 g Sodium carbonate 8 g MMA (97%) 1940 g EA (1%) 20 g 1,3-butylene methacrylate (BDMA) (2%) 40
g (g) Raw material Deionized water 500 g Potassium persulfate (KPS) 24 g (2-2) Production of the second step (d)
In the above-mentioned container containing the amount of the hard crosslinked resin latex corresponding to the part, the aqueous solution of the following (h) is added, and the temperature is raised to 80 ° C. Was added. After the addition was completed, polymerization was continued for further 3 hours to obtain a multi-layered acrylic elastic latex containing a hard cross-linked resin inside the particles.

(H) Raw material Sarcosinate LN 30g Rongalite 32g Deionized water 500g (R) Raw material BA (80%) 6400g ST (18%) 1440g Allyl cinnamate (ACM) (1.5%) 96g 1,4-butanediol diacrylate (C) ₄ −DA) (0.5
%) 32 g t-butyl hydroperoxide (TBH) 23 g In the above case, the polymerization yields of BA and ST are 97% and 99.5% or more, respectively.
The particle size of the obtained latex was 0.26 to 0.28 μm.

(2-3) Production of Third Step (e) Into the above-mentioned container containing latex corresponding to 100 parts of the solid component obtained in the above polymerization (2-2), an aqueous solution of the following (nu) was added. After stirring, the following monomer mixture (I) was continuously added over 2.5 hours. Then one more
The polymerization was continued for a period of time to obtain a graft copolymer (II-2) in the form of a latex. The polymerization yield of MMA in the monomer mixture was 99.5
% Or more.

(Nu) Raw material Sarcosinate LN 20 g Deionized water 500 g (L) Raw material MMA (96%) 4800 g EA (4%) 200 g Normal octyl mercaptan (nC ₈ SH) 12.5 g TBH 5 g This latex is described below. Coagulation, washing and drying were performed according to the method to obtain a powder of the graft copolymer (II-2). That is, 60 kg of 1.0% sulfuric acid aqueous solution was charged into a stainless steel container, the temperature was raised to 80 ° C. with stirring, 35 kg of latex was continuously added over 20 minutes, and then the internal temperature was raised to 95 ° C. and maintained for 5 minutes. After cooling to room temperature, the polymer was separated and washed with deionized water to obtain a white creamy polymer, which was dried at 70 ° C. for 24 hours to obtain a white powdery polymer.

Examples 1 to 5, Comparative Examples 1 to 4 Alon GS-30 (product of Toa Gosei Chemical Co., Ltd.) as a thermoplastic resin (I), a graft copolymer (II), and a copolymer (III), and Super Mixer (SMV manufactured by Kawada Seisakusho Co., Ltd.) containing 20 stabilizers in the ratio shown in Table 1
-20 type) and blended for 3 minutes at a stirring speed of 1800 rpm.

A blend of the obtained resin composition was used as a screw-type extruder having an outer diameter of 40 mmφ (P-40-26AB- manufactured by Japan Steel Works, Ltd.).
V type, L / D = 26), cylinder temperature 150 ~ 240
After melt-kneading at 200 ° C. and a die temperature of 200 to 240 ° C. to form pellets, test pieces obtained by injection molding under the following conditions were evaluated, and the results shown in Table 2 were obtained.

Injection molding machine: V-17-65 type screw-type automatic injection molding machine manufactured by Nippon Steel Works Injection molding conditions: Cylinder temperature 200-240 ° C Mold temperature 55 ° C Specimen size: 110mm × 110mm × 2mm (thickness) ) (For measuring gloss, total light transmittance, haze and observing the appearance of molded products) 70mm x 12.5mm x 6.2mm (thickness) (for measuring Izod impact strength) Example 6, Comparative Example 5 MMA resin as the thermoplastic resin (I), graft copolymer (II-2) as the graft copolymer (II), and "LSI-60" (Soken) as the copolymer (III) An experiment was performed in the same manner as in Example 1 in the case where (Chemical Co., Ltd. product) was used (Example 6) and in the case where it was not used (Comparative Example 5). Table 3 shows the usage ratio, and Table 4 shows the evaluation results.

Comparative Example 6 In the same manner as in Example 5 except that dimethylpolysiloxane “L-49-100 centistokes” having a number average molecular weight of 6290 (manufactured by Nippon Unicar Co., Ltd.) was used instead of the copolymer (III). An experiment was performed. Table 3 shows the usage ratio, and Table 4 shows the evaluation results.

[Effects of the Invention] The impact-resistant resin composition of the present invention is imparted with good impact resistance without sacrificing the inherent characteristics of the thermoplastic hard resin, and the transparency is particularly high in a transparent resin. It is not hindered and has excellent industrial effects.

Claims (1)

(57) [Claims] 1. A crosslinked rubbery polymer having an average particle size of 0.05 to 1 μm containing 97 to 50 parts by weight of a thermoplastic resin (I) and an alkyl acrylate as a constitutional unit, and an aromatic vinyl compound and (meth) acrylic acid. With respect to 100 parts by weight of a total amount of 3 to 50 parts by weight of a graft copolymer (II) obtained by graft-polymerizing a monomer mixture containing at least one selected from alkyl esters as a constituent unit, the following general formula: (Wherein R ₁ represents hydrogen or a methyl group, and R ₂ represents an aliphatic or alicyclic hydrocarbon group or an arylalkyl group).
90% by weight and the following general formula (Wherein, R ₃ is hydrogen or a methyl group, l and n are each 0 to
An integer of 2, m is 0 or 1, R ₄ is an alkyl group or a phenyl group, and x is an integer of 1 to 100. An impact-resistant resin composition comprising 0.001 to 5 parts by weight of a copolymer (III) with 90 to 10% by weight of a radically polymerizable silicone macromer (b) represented by the formula (1).