JPS6225176B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a thermoplastic resin composition that has an excellent balance of mechanical properties such as impact resistance and weather resistance, and is capable of producing molded articles with good appearance. Known as a typical impact-resistant resin
ABS resin has a serious drawback of poor weather resistance due to the fact that the diene rubber, which is the graft rubber substrate, easily deteriorates. Searches have been conducted to improve this drawback and obtain thermoplastic resins with excellent both impact resistance and weather resistance.For example, as a graft rubber substrate (1) ethylene-propylene-nonconjugated diene A method using a tertiary copolymer rubber and (2) a method using an acrylic acid ester rubber polymer have been proposed. However, since method (1) above uses bulk polymerization or solution polymerization, there are problems such as the inability to obtain a polymer with a high rubber content and the complicated process of removing the solvent. In addition, since the emulsion polymerization method is adopted in the above method (2), there are problems such as difficulty in controlling the particle size of the rubbery polymer and a complicated polymer recovery process. Therefore, the above-mentioned conventional method not only has several problems in terms of the manufacturing process, but also the impact resistance of the resulting thermoplastic resin is not fully satisfactory. Therefore, the present inventors aimed to solve the problems of the above-mentioned conventional methods and efficiently obtain a thermoplastic resin with excellent balance between impact resistance and weather resistance. As a result of investigation from this viewpoint, we found that a copolymer of ethylene and α,β-unsaturated carboxylic acid glycidyl ester is effective as a blended rubbery polymer, and that a copolymer of α,β-unsaturated carboxylic acid glycidyl ester is effective as a blended rubber polymer. -We have discovered that the best effects can be obtained by using a modified vinyl polymer copolymerized with a small proportion of unsaturated carboxylic acid, and have thus arrived at the present invention. That is, the present invention provides (b) α for at least one vinyl monomer selected from the group consisting of (A) (b) aromatic vinyl monomers, vinyl cyanide monomers, and (meth)acrylic acid ester monomers. ,β
- At least one unsaturated carboxylic acid from 0.01 to 5
A modified vinyl polymer obtained by copolymerizing % by weight, and
(B) The proportion of the ethylene copolymer obtained by copolymerizing ethylene with 0.5 to 30% by weight of at least one α,β-unsaturated carboxylic acid glycidyl ester in 100 parts by weight of the total composition is ( A): 50 to 99 parts by weight, (B): 1 to 50 parts by weight of a thermoplastic resin composition (first invention), and (A) (b) α,
(B) a modified vinyl polymer similar to the above (A) in which the copolymerized amount of β-unsaturated carboxylic acid is 0.1 to 10% by weight;
A vinyl polymer consisting of the same ethylene copolymer as above and (C) at least one vinyl monomer selected from the group consisting of aromatic vinyl monomers, vinyl cyanide monomers, and (meth)acrylic acid ester monomers. The proportions of the combined components in 100 parts by weight of the total composition are (A): 5 to 90 parts by weight, (B): 1 to 50 parts by weight, and (C): 5 to 90 parts by weight. The present invention provides a thermoplastic resin composition (second invention) comprising: Since the thermoplastic resin composition of the present invention can be obtained as a simple blend compound without undergoing the graft polymerization process as in the conventional method, various problems in the manufacturing process are solved. Furthermore, the present invention is characterized in that a vinyl polymer such as a styrene/acrylonitrile copolymer is used after being modified with an α,β-unsaturated carboxylic acid such as acrylic acid. , β-unsaturated carboxylic acid glycidyl ester copolymer).
A composition having sufficient impact resistance and weather resistance can be obtained. The modified vinyl polymer (A) used in the present invention is (a)
Aromatic vinyl monomers such as styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o-chlorostyrene, m-chlorostyrene, and p-chlorostyrene, acrylonitrile, methacrylonitrile, etc. (b) α, A specific amount of at least one β-unsaturated carboxylic acid is copolymerized. Among the vinyl monomers (a) above, styrene, α-methylstyrene, acrylonitrile, and methyl methacrylate are particularly preferred;
A species or a combination of two or more species can be used. The α,β-unsaturated carboxylic acids mentioned here include acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, fumaric acid, itaconic acid, etc., with acrylic acid and methacrylic acid being preferably used. . (b) α, β- in this modified vinyl polymer (A)
The amount of copolymerized unsaturated carboxylic acid is 0.01 to 5% by weight, preferably 0.05 to 3% by weight in the case of the first invention, and 0.1 to 10% by weight, preferably 0.5 to 3% by weight in the case of the second invention. 5% by weight is appropriate; in any case, if the copolymerization amount is below the above lower limit, the affinity with the ethylene copolymer (B) explained below will be insufficient and the desired impact resistance will not be obtained; If it exceeds the above upper limit, the surface gloss of the molded product made from the composition will decrease, which is not preferable. Typical modified vinyl polymers (A) include styrene/acrylic acid copolymer, styrene/acrylonitrile/acrylic acid copolymer, styrene/methyl methacrylate/acrylic acid copolymer, and styrene/acrylic acid copolymer.
Examples thereof include acrylonitrile/methyl methacrylate/acrylic acid copolymers and copolymers in which methacrylic acid is used instead of acrylic acid. These modified vinyl copolymers (A) can be produced by known polymerization methods such as bulk polymerization and bulk-suspension polymerization. On the other hand, the ethylene copolymer (B) used in the present invention
is a glycidyl group-containing ethylene copolymer obtained by copolymerizing 0.5 to 30% by weight of α,β-unsaturated carboxylic acid glycidyl ester with respect to ethylene. Here, α,β-unsaturated carboxylic acid glycidyl ester has the general formula

[Formula] (wherein R is a hydrogen atom, a lower alkyl group, or a lower alkyl group substituted with a glycidyl ester group), specifically glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate,
Examples include glycidyl itaconate, among which glycidyl methacrylate is preferably used. The copolymerized amount of α,β-unsaturated carboxylic acid glycidyl ester in the ethylene copolymer (B) is
A range of 0.5 to 30% by weight, especially 1 to 20% by weight is appropriate; if it is less than 0.5% by weight, sufficient affinity with the modified vinyl polymer (A) cannot be exhibited;
The above is not preferable because the flexibility of the ethylene copolymer itself is impaired and a composition with excellent mechanical properties cannot be obtained. The ethylene copolymer (B) also contains a small proportion of other copolymerizable unsaturated monomers, such as propylene, α-olefins such as budene-1, vinyl ethers, vinyl acetate, vinyl propionate, etc. One or more types of vinyl esters, acrylics and methacrylic esters such as methyl, ethyl, propyl, butyl, acrylonitrile, styrene, carbon monoxide, etc. may be copolymerized. Specific examples of the ethylene copolymer (B) include ethylene/glycidyl methacrylate copolymer, ethylene/vinyl acetate/glycidyl methacrylate copolymer, ethylene/carbon monoxide/glycidyl methacrylate copolymer, and ethylene/glycidyl methacrylate copolymer. Examples include glycidyl acrylate copolymer and ethylene/glycidyl acrylate/vinyl acetate copolymer, which can be produced by known polymerization methods. In the composition of the present invention, the proportion of the ethylene copolymer (B) in 100 parts by weight of the total composition is preferably 1 to 50 parts by weight, particularly 5 to 40 parts by weight. The impact resistance is insufficient, and if the amount exceeds 50 parts by weight, mechanical properties such as tensile properties will deteriorate, which is not preferable. In the present invention, a thermoplastic resin composition that has the desired impact resistance and weather resistance is obtained by blending two components, a modified vinyl copolymer (A) and an ethylene copolymer (B), in the above ratio. Furthermore, this modified vinyl copolymer (A) and a vinyl polymer (C) that does not contain α,β-unsaturated carboxylic acid as a modified copolymerization component can be obtained. The same object can also be achieved by a three-component thermoplastic resin composition (second invention) in which the ethylene copolymer (B) is blended with the mixture. The vinyl polymer (C) used here is styrene,
Aromatic vinyl monomers such as α-methylstyrene, vinyl cyanide monomers such as acrylonitrile, and (meth)
A polymer formed by polymerizing at least one selected from acrylic acid ester monomers, specifically polystyrene, polymethyl methacrylate, styrene/acrylonitrile copolymer, styrene/
Examples include methyl methacrylate copolymer, styrene/acrylonitrile/methyl methacrylate copolymer, etc., which are produced by known polymerization methods such as suspension polymerization, bulk polymerization, and bulk-suspension polymerization. Ru. Modified vinyl copolymer (A) and ethylene copolymer (B) in the three-component composition of the present invention (second invention)
The blending ratio of vinyl polymer (C) is 100% of the total composition.
Appropriate ratios are such that (A) occupies 5 to 90 parts by weight, (B) occupies 1 to 50 parts by weight, and (C) occupies 5 to 90 parts by weight. In this three-component thermoplastic resin composition, the amount of α,β-unsaturated carboxylic acid copolymerized in the modified vinyl copolymer (A) is slightly increased, and this is diluted with the vinyl polymer (C). The so-called master batch method is also adopted. In addition, when adding at least one selected from organic sulfonates and sulfate ester salts to the thermoplastic resin composition of the present invention, if desired,
A composition with further improved impact resistance and weather resistance can be obtained. The organic sulfonate and sulfuric ester salt mentioned here have the general formula R(SO ₃ M)n
and R(OSO ₃ M)n.
However, in the formula, M represents a metal atom, R represents an organic group, and n represents an integer of 1 or more. Preferred examples of M include alkali metals such as lithium, sodium, and potassium; alkaline earth metals such as magnesium, calcium, strontium, and barium;
Alternatively, zinc, aluminum, etc. may be mentioned.
Preferred examples of R include phenyl, α-naphthyl, β-naphthyl, dodecyl phenyl, dodecylnaphthyl, allyl, methacryl, and high molecular weight substances such as polystyrene and polyethylene glycol. A preferable example of the organic sulfonate is the general formula (wherein M is lithium, sodium, potassium, calcium, R' and R'' are methyl, ethyl, phenyl, 2-hydroxyethyl, 4-hydroxybutyl), sodium dodecylbenzenesulfonate, These include sodium dodecylnaphthalene sulfonate, sodium methacryl sulfonate, potassium 1,5-naphthalenedisulfonate, formalin condensate of naphthalene sulfonate, sodium salt of sulfonated polystyrene, etc. Preferred examples of sulfate ester salts include sodium lauryl sulfate and lauryl sulfate. Potassium sulfate, calcium stearyl sulfate, barium stearyl sulfate, sodium polyoxyethylene ether sulfate, sodium polyoxyethylene dodecyl phenyl ether sulfate, etc. Two or more of these organic sulfonates and sulfate ester salts may be used in combination. The amount of these organic sulfonate salts and sulfate ester salts is determined by
10 parts by weight or less, preferably 0.1 to 100 parts by weight
A suitable amount is 5 parts by weight, and 10 parts by weight or more is not preferred because the color tone of the composition deteriorates. In addition, the thermoplastic resin composition of the present invention may contain conventional additives such as antioxidants, ultraviolet absorbers, heat stabilizers, lubricants, mold release agents, dyes, and pigments within a range that does not impair the purpose of the present invention. Contains colorants, fibrous and particulate fillers (e.g. glass fibers,
glass beads, carbon fiber, calcium carbonate, magnesium carbonate, barium sulfate, finely divided silicic acid, wollastenite, talc, clay, mica, sericite, zeolite, pennite, dolomite, kaolin, etc.) and reinforcing agents, nucleating agents, flame retardants It may be modified with, etc. These additives may be added singly or in combination of two or more. Small amounts of other thermoplastic resins may also be added. Although there are no particular limitations on the method for producing the thermoplastic resin composition of the present invention, a mixture of two or three polymers and other additives added as necessary are mixed into a modified vinyl copolymer (A), A method of melting and mixing at a temperature higher than the softening point of is preferred. Specifically, a method of melt-mixing polymers (A) and (B), polymers (A), (B)
and (C), a method of melt-mixing polymers (A) and (C)
Examples include a method in which the polymer (B) is further melt-mixed into the molten mixture, and a method in which desired additives are simultaneously melt-mixed in the polymer (B). Note that as the melt-mixing means, any means such as a Banbury mixer and an extruder can be employed. The thermoplastic resin composition of the present invention obtained in this way has excellent mechanical properties such as impact resistance and tensile properties, and excellent weather resistance in a well-balanced manner, and can be expected to be applied to a variety of uses that take advantage of these properties. . The effects of the present invention will be explained in further detail with reference to Examples below. In addition, the evaluation of mechanical properties in the examples is
This is a value measured according to ASTM standards. Examples 1 to 7 and Comparative Examples 1 to 4 The modified vinyl copolymer (A), ethylene copolymer (B) and additives shown in Table 1 were mixed in the proportions shown in Table 1, and 250 The mixture was melt-kneaded and pelletized using a screw extruder set at ℃. Test pieces were molded from each pellet by injection molding, and the mechanical properties, weather resistance, and appearance of the molded products were evaluated. Table 1 shows the results. Regarding the 1/4″ Izotsu impact test piece,
Impact resistance and weather resistance were simultaneously evaluated by measuring the impact strength before (a) and after (b) irradiation with a weather meter for 100 hours, and by determining the degree of decrease in impact strength after irradiation. The appearance of the molded product was determined by visual inspection of the test piece.
The criteria for judgment were ○ - good, and × - poor due to loss of gloss. Further, the contents of the abbreviations in Tables 1 and 2 below are as follows. ST: Styrene AN: Acrylonitrile MMA: Methyl methacrylate AA: Acrylic acid MAA: Methacrylic acid MLA: Maleic acid anhydride E: Ethylene GMA: Glycidyl methacrylate VA: Vinyl acetate MA: Methyl acrylate SDBS: Sodium dodecylbenzenesulfonate SSIA: Sodium 3,5-dicarboxybenzenesulfonate LSN: Sodium lauryl sulfate As is clear from the results in Table 1, the thermoplastic resin compositions of the present invention (Examples 1 to 7) have excellent impact resistance and tensile properties. It has excellent weather resistance and a balanced appearance of molded products. On the other hand, modified with α,β-unsaturated carboxylic acid

[Table] When using a vinyl copolymer that does not contain epoxy groups as a base (Comparative Example 1) or when blending polyethylene that does not contain epoxy groups with a modified vinyl copolymer (Comparative Example 2), the affinity between the polymers is As a result, only compositions with extremely low impact resistance can be obtained. Also, α, β- for modified vinyl copolymer (A)
If the copolymerization amount of unsaturated carboxylic acid is 5% by weight or more (Comparative Example 3), the fluidity of the composition decreases, resulting in extremely poor appearance of the molded product, and the ethylene copolymer (B)
If the blending amount is 50 parts by weight or more (Comparative Example 4), the tensile properties of the composition will deteriorate significantly, which is not preferable. Examples 8 to 12 and Comparative Examples 5 to 6 The modified vinyl copolymer (A), ethylene copolymer (B), vinyl polymer (C) and additives shown in Table 2 were each They were mixed in the proportions shown in the table and melt-kneaded and pelletized using a screw extruder set at 250°C. Test pieces were molded from each pellet by injection molding, and the mechanical properties, weather resistance, and appearance of the molded pieces were evaluated. The results are shown in Table 2.

[Table] As is clear from the results in Table 2, the three-component thermoplastic resin compositions of the present invention (Examples 8 to 12) also have mechanical properties such as impact resistance, weather resistance, and molded products. To give a molded product with a well-balanced appearance. On the other hand, α and β for modified vinyl copolymer (A)
- When the amount of unsaturated carboxylic acid copolymerized is 0.1% by weight or less (Comparative Example 5) or 10% by weight or more (Comparative Example 6), the affinity between polymers does not improve and sufficient impact resistance cannot be obtained. do not have.

Claims (1)

[Scope of Claims] 1 (A) (B) At least one vinyl monomer selected from the group consisting of aromatic vinyl monomers, vinyl cyanide monomers, and (meth)acrylic acid ester monomers, ) a modified vinyl polymer copolymerized with 0.01 to 5% by weight of at least one α,β-unsaturated carboxylic acid; and (B) at least one α,β-unsaturated carboxylic acid glycidyl ester based on ethylene. The proportion of the ethylene copolymer obtained by copolymerizing 0.5 to 30% by weight of (A) to 100 parts by weight of the total composition is 50 to 99 parts by weight, and 1 to 50 parts by weight (B). A thermoplastic resin composition formulated as follows. 2 (A) (a) At least one vinyl monomer selected from the group consisting of aromatic vinyl monomers, vinyl cyanide monomers, and (meth)acrylic acid ester monomers, (b) A modified vinyl polymer obtained by copolymerizing at least one saturated carboxylic acid from 0.1 to 10% by weight, (B) α, β with respect to ethylene.
- Ethylene copolymer obtained by copolymerizing 0.5 to 30% by weight of at least one type of unsaturated carboxylic acid glycidyl ester, and (C) aromatic vinyl monomer, vinyl cyanide monomer, and (meth)acrylic acid ester type The proportion of the vinyl polymer made of at least one vinyl monomer selected from the group consisting of monomers in 100 parts by weight of the total composition is (A): 5
~90 parts by weight, (B): 1 to 50 parts by weight, and (C): 5 to
A thermoplastic resin composition containing 90 parts by weight.