JPH0637537B2 - Method for producing thermoplastic resin - Google Patents

Description

The present invention relates to a method for producing a rubber-modified thermoplastic resin which is excellent in mechanical properties and moldability and has a matte surface with no gloss.

Rubber-modified thermoplastic resins are used in various applications because of their excellent impact resistance, moldability, and good surface gloss. However, depending on the intended use, it may be desired that the surface of the molded article be matte without deteriorating other physical properties.

Examples of applications in which such matting is required include interior parts of automobiles, office and household electric equipment parts, and the like.

As a conventional method for matting a molded article, a method of adding oxides or carbonates of titanium, magnesium, calcium, etc. to a rubber-reinforced resin is well known, but in this method, mechanical properties of the resin, particularly There is a drawback that the impact strength is greatly reduced, and there is a defect that the gloss of the surface of the molded product does not disappear even though it is matte.

A well-known method is to add a rubber-like elastic material to a rubber-reinforced resin to remove the luster, but this method lowers the mechanical properties of the resin, particularly hardness and rigidity. Also,
Foreign matters appear on the surface of the molded product, and the commercial value of the molded product is significantly impaired.

Further, a method of adding a three-dimensional resin component using a crosslinkable monomer is also known, but it has drawbacks such as uneven gloss on the surface of the molded product and deterioration of moldability.

The present inventors have developed a matte rubber reinforced thermoplastic resin that has improved the above-mentioned conventionally known technical problems such as impact resistance, rigidity, deterioration of moldability, and occurrence of uneven gloss. As a result of earnest studies for the purpose of achieving the above, the present invention has been achieved.

That is, the present invention provides a vinyl aromatic compound (b), a vinyl cyan compound (c), an ethylenically unsaturated carboxylic acid (d), and a compound (copolymerizable with these in the presence of the rubbery polymer (a) ( A method for producing a rubber-modified thermoplastic resin by polymerizing a monomer (f) comprising e), wherein the content of each component in the rubber-modified thermoplastic resin is a rubber-like polymer (a).
Of 5 to 60% by weight, copolymerized vinyl aromatic compound (b) of 34.7 to 90% by weight, copolymerized vinyl cyan compound (c) of 4.7 to 40% by weight, and The ethylenically unsaturated carboxylic acid (d) is 0.3
-3% by weight, and 0-20% by weight of the copolymerizable compound (e) being copolymerized, the present invention provides a method for producing a matte thermoplastic resin.

As the constituent component of the resin of the present invention, the rubber-like polymer (a)
In the presence of a vinyl aromatic compound (b), a vinyl cyan compound (c), an ethylenically unsaturated carboxylic acid (d), and optionally a compound (e) copolymerizable therewith It relates to the copolymer (A) obtained by polymerizing the mixture (f).

As the rubbery polymer (a), a diene rubbery polymer and a non-diene rubbery polymer can be used. Examples of the diene rubber polymer include polybutadiene, natural rubber, styrene-butadiene copolymer (SBR), acrylonitrile-butadiene copolymer (NBR), polyisoprene,
Examples thereof include polychloroprene. These rubber-like polymers are produced by emulsion polymerization, solution polymerization, etc., and polybutadiene, polyisoprene, SBR coupled with tin or lithium, etc., and styrene-butadiene block copolymers, etc. can also be used. .
These rubber-like polymers may be used alone or in admixture of two or more.

On the other hand, examples of the non-diene rubber-like polymer include ethylene-propylene copolymer, ethylene-propylene-non-conjugated diene copolymer, chlorinated polyethylene and macryl rubber-like polymer. These non-diene rubbery polymers can be used alone or in admixture of two or more. Further, the diene rubber-like polymer and the non-diene rubber-like polymer may be mixed and used.

As the vinyl aromatic compound (b), styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-ethylstyrene, methyl-α-methylstyrene, dimethylstyrene, chlorostyrene, Dichlorostyrene, bromostyrene, dibromostyrene, vinylnaphthalene and the like can be mentioned, but preferred monomers are styrene and α-methylstyrene.

Examples of the vinyl cyan compound (c) include acrylonitrile and methacrylonitrile.

Examples of the ethylenically unsaturated carboxylic acid (d) include acrylic acid, methacrylic acid, ethacrylic acid, itaconic acid, maleic acid, fumaric acid, and the like. Preferred monomers are acrylic acid and methacrylic acid.

The compound (e) copolymerizable with the above-mentioned monomer, such as a vinyl compound having an amide group, an N-methylol compound, an ethylenically unsaturated carboxylic acid ester and a polyfunctional monomer can be used.

Examples of the compound having an amide group or the N-methylol compound include acrylamide, methacrylamide,
Examples include N-methylol acrylamide. Examples of the ethylenically unsaturated carboxylic acid ester compound include alkyl acrylate, alkyl methacrylate, and esters of ethylenically unsaturated carboxylic acid and hydroxyalkyl, and examples of the alkyl acrylate include methyl acrylate and ethyl acrylate. Examples of the alkyl methacrylate include methyl methacrylate and ethyl methacrylate. Examples of the hydroxyalkyl ester of ethylenically unsaturated carboxylic acid include β-hydroxyethyl acrylate and β-hydroxyethyl methacrylate. Examples of polyfunctional monomers include divinylbenzene.

Among the embodiments of the present invention, preferable ones will be described below.

(1) Copolymerizable with vinyl aromatic compound (b), vinyl cyanide compound (c), ethylenically unsaturated carboxylic acid (d), and if necessary, in the presence of rubbery polymer (a) A resin comprising a graft copolymer resin (A) obtained by polymerizing a monomer mixture (f) comprising a compound (e).

(2) A composition comprising the above (A) as an essential component and a vinyl aromatic (co) polymer (B).

The graft copolymer (A) is obtained by emulsion-polymerizing, suspension-polymerizing, solution-polymerizing, bulk-polymerizing the monomer mixture (f) in the presence of the rubber-like polymer (a), or combining them. It is obtained by such as.

As the vinyl aromatic (co) polymer (B), a polymer of the vinyl aromatic compound (b) alone, or the vinyl aromatic compound (b) and the vinyl cyan compound (c), and the above copolymerizable And a copolymer with at least one compound selected from the above compounds (d).

The content of the rubbery polymer (a) in the above (A) of the present invention is 5 to 60% by weight, preferably 5 to 40% by weight, and more preferably 5 to 30% by weight.

The content of ethylenically unsaturated carboxylic acid in (A) is 0.3 to 3% by weight, preferably 0.5 to 2% by weight.

The content of the vinyl aromatic compound (b) in the (A) is 34.7 to 90% by weight, preferably 54.7 to 90% by weight, and more preferably 59.5 to 90% by weight. Cyan compound (c) content is 4.7-40% by weight
Is more preferable, 4.5 to 35% by weight is more preferable, and the other copolymerizable compound (e) is preferably 20% by weight or less, more preferably 0 to 10% by weight.

The rubbery polymer contributes to the improvement of impact resistance, and if the amount is small, the impact resistance cannot be obtained, while if the amount is large, the hardness decreases.
The usage will be limited. When the content of the ethylenically unsaturated carboxylic acid monomer is 0.3% by weight or less, the matting effect is not sufficient, and when it exceeds 3.0% by weight, uneven gloss is generated on the surface of the molded product. It is not preferable because it gives a non-uniform matte state.

The content of the vinyl cyan compound contributes to the improvement of impact resistance and chemical resistance, and when it is small, it is not preferable because it causes reduction of impact resistance and chemical resistance. On the other hand, when it is large, the processability and color tone are not preferable.

The content of the vinyl aromatic compound contributes to the moldability, and when it is too small, the moldability is deteriorated, which is not preferable. On the other hand, when the amount is large, the amount of the vinyl cyan compound monomer used is small, and the unfavorable behavior described above occurs.

The component ratio (% by weight) of the rubbery polymer and the monomer mixture (f) used in the production of the above (A) is 5 to 60 /
95-40 is preferable, More preferably, it is 5-40 / 9.
5 to 60.

The composition ratio (total 100% by weight) of the monomer mixture (f) is vinyl aromatic compound (b) / vinyl cyan compound (c) / ethylenically unsaturated carboxylic acid (d) /
The ratio of the other copolymerizable compound (e) is 30 to 92.6.
8/7 to 40 / 0.32 to 30/0 to 25 are preferable,
More preferably 45 to 89.47 / 10 to 35/0.
It is 53-20 / 0-15.

By appropriately using a monomer within the above-mentioned monomer range, 34.7 to 90% by weight of the copolymerized vinyl aromatic compound (b) in (A) and a copolymerized cyan Vinyl chloride compound (c) is 4.7 to 40% by weight, copolymerized ethylenically unsaturated carboxylic acid is 0.3 to 3% by weight, and copolymerizable compound (e) is 0.
It is preferable that the content be ˜20% by weight.

When the content of the ethylenically unsaturated carboxylic acid in the above (A) is too small, the matting effect is not sufficiently obtained, and when it is too large, the mixing property with the rubber-modified thermoplastic resin is deteriorated.

The intrinsic viscosity [η] (MEK30 ° C) of the methyl ethyl ketone (MEK) soluble component (A) is 0.3 to 0.8.
d / g is preferable, and if it is less than 0.3 d / g, the matte effect is not sufficient, and if it exceeds 0.8 d / g, the matte state of the molded product is not uniform, which is not preferable.

The resin (A) of the present invention is a resin having a matte property by itself. It can be blended with other resins such as polyphenylene oxide, vinylidene fluoride resin, nylon, polyacetal and the like, and has a matting effect, but especially the above vinyl aromatic (co) polymer and rubber-modified thermoplastic resin. The composition with and has excellent characteristics.

That is, the resin according to the present invention retains its high impact strength and rigidity and can obtain a good matting effect without causing uneven gloss on the surface of the molded product, and can be used for internal parts of automobiles and interior materials and household products. Also, it can be used for business electrical equipment parts and the like.

Further, the resin of the present invention is not limited to injection molding, but extrusion molding,
It also provides a good matt molded product in vacuum molding and the like, and has an extremely high industrial utility value.

Next, the present invention will be described more specifically based on Examples and Comparative Examples, but the present invention does not exceed the gist of the invention.
It is not limited by the examples.

Example 1 Polybutadiene latex JSR # 0700 20 parts (solid content 58%), water 250 parts, potassium oleate 1
To 0 part of the mixed solution, 0.2 part of sodium pyrophosphate, 0.2 part of dextrose, 0.004 part of ferrous sulfate and 0.4 part of cumene hydroperoxide are added.

Each of the monomers shown in Table 1 (total 80 parts) and t-
A mixture of 0.3 parts of dodecyl mercaptan was stirred and added dropwise to the reactor under a nitrogen stream. The dropping time was 2 hours and the polymerization temperature was 60 ° C. The polymerization was almost complete. As a result, the obtained resin latex was coagulated, dried, pelletized and then subjected to injection molding. The evaluation results are shown in Table 1.

It can be seen from Table 1 that the resin composition of the present invention has good impact resistance and the gloss of the molded product disappears uniformly.

On the other hand, when the amount of unsaturated carboxylic acid is small, the matte effect cannot be obtained, and when it is excessive, the gloss decreases, but
The surface of the molded product becomes uneven in gloss, resulting in an uneven matte state.

Comparative Example c (Use of Rubber Copolymerized with Acrylic Acid) A rubbery polymer latex was prepared by the following method. Three
Into a reaction vessel equipped with a stirrer of paddle type, 92 parts of butadiene, 8 parts of acrylic acid, 2 parts of t-dodecyl mercaptan, 0.5 parts of potassium rosinate, 200 parts of ion-exchanged water, 2 parts of potassium persulfate, and polymerized at 50 ° C. The reaction was carried out until the conversion rate reached 90%. Unreacted monomers were removed, and the obtained latex was used for graft polymerization by the following method. 20 parts of the above latex (solid content), 250 parts of water, 10 parts of potassium oleate, 0.2 parts of sodium pyrophosphate, 0.2 parts of dextrose were placed in a container equipped with a stirrer, a jacket for heating, and a nitrogen gas blowing port. Parts, 0.004 parts of ferrous sulfate and cumene hydroperoxide were charged and the temperature was raised to 60 ° C. A mixed solution of 60 parts of styrene, 20 parts of acrylonitrile and 0.3 part of t-dodecyl mercaptan was added thereto over 2 hours to complete the graft polymerization. As a result, the obtained resin latex was coagulated with calcium chloride, dried, pelletized, and subjected to injection molding. Evaluation result is impact value 32kgcm
/ cm, the surface gloss was 72%, and a resin having a good surface appearance but having no loss of gloss was obtained.

Comparative Example d (MAH Copolymer) Styrene 67 parts Acrylonitrile 15.5 parts Styrene-butadiene copolymer rubber in an autoclave equipped with a stirrer, a thermometer, a temperature controller, a dropping funnel, a reflux condenser and a nitrogen gas inlet. 10 parts (Asahi Kasei product Tafuden 2000) benzoyl peroxide 0.2 parts dicumyl opaxide 0.1 part t-dodecyl mercaptan 0.5 parts were charged and sufficiently dissolved, and then the atmosphere in the autoclave was replaced with nitrogen. Separately, a mixed solution of 2.5 parts of maleic anhydride and 5 parts of acrylonitrile was prepared and charged in a dropping funnel. Then, while maintaining the temperature in the polymerization tank at 72 ° C., while stirring the solution, the above maleic anhydride-acrylonitrile solution was added from the dropping funnel.
Added continuously over time. After the addition is complete, continue 1
Bulk polymerization was continued for hours.

Then, to this polymerization system was added a prepared suspension consisting of tricalcium phosphate 10 parts dodecylbenzene 0.01 part sodium sulfonate ion-exchanged water 90 parts with stirring, and the prepolymer produced in the bulk polymerization step was added. Suspended. Then 12
After suspension polymerization was carried out at a temperature of 0 ° C. for 4 hours, polymer beads were separated from the slurry, washed with water and dried. The obtained polymer contained 2.8% by weight of maleic anhydride. As a result of the evaluation, the impact value was as low as 5 kgcm / cm, the surface gloss was 38%, and uneven gloss was seen on the surface appearance.

Continuation of the front page (56) Reference JP 58-2313 (JP, A) JP 57-14612 (JP, A) JP 55-19247 (JP, B2) JP 55-5765 (JP) , B2)

Claims (1)

[Claims] 1. A vinyl aromatic compound (b), a vinyl cyan compound (c), an ethylenically unsaturated carboxylic acid (d) in the presence of a rubbery polymer (a), and a compound copolymerizable with these ( A method for producing a rubber-modified thermoplastic resin by polymerizing a monomer (f) comprising e), wherein the content of each component in the rubber-modified thermoplastic resin is 5 or more for the rubber-like polymer (a). ~ 60 wt%, copolymerized vinyl aromatic compound (b) 34.7 to 90 wt%, copolymerized vinyl cyan compound (c) 4.7 to 40 wt%, copolymerized The ethylenically unsaturated carboxylic acid (d) is 0.3 to
3% by weight, and the copolymerizable compound (e) being copolymerized is 0 to 20% by weight, a method for producing a thermoplastic resin.