JP2671492B2 - Thermoplastic resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a thermoplastic resin composition excellent in impact resistance, molding processability, heat resistance, chemical resistance and surface appearance.

[Prior Art] Acrylonitrile-styrene-based rubber-reinforced resins (ABS, AES, AAS resins, etc.) have excellent impact resistance,
It has processability and surface appearance and is widely used as a molding resin. However, chemical resistance and abrasion resistance are not sufficient, and use under severe conditions is restricted.

Polyamide resins have excellent chemical resistance and abrasion resistance and are widely used as engineering plastics, but they have the drawback of being inferior in impact resistance.

In order to improve the impact resistance of polyamide resin, AB
A blend with S resin has been proposed (Japanese Patent Publication No. 38-23476).
No.).

Further, a blend of a graft copolymer formed by graft-copolymerizing an α, β-unsaturated dicarboxylic acid anhydride or an unsaturated carbonamide with a rubber-like polymer together with another polymer, and a polyamide resin has also been proposed. (JP-B-56-112957, JP-A-58-93745).

Also, in Japanese Patent Application No. 62-12856, we have proposed a blend of a polyamide resin and a graft copolymer obtained by copolymerizing an α, β-unsaturated carboxylic acid.

[Problems to be Solved by the Invention] However, a mere blend of an ABS resin and a polyamide resin has poor compatibility and remarkably low mechanical properties. Further, by graft-copolymerizing a monomer having a functional group having an affinity with the amide group of the polyamide resin to the rubber-like polymer, the compatibility with the polyamide resin can be improved, but the impact resistance is insufficient, Further, only those having high melt viscosity and poor moldability have been obtained.

Further, although the impact resistance of the composition of Japanese Patent Application No. 62-12856 previously proposed by us is dramatically improved as compared with the above-mentioned system,
The surface appearance was inferior.

An object of the present invention is to resist a thermoplastic resin composition having an extremely high impact resistance and an excellent surface appearance, without impairing the molding processability of the ABS resin, and also having the chemical resistance of the polyamide resin. It is in.

"Means for Solving Problems" The present inventors have arrived at the present invention as a result of intensive studies to solve the above problems.

 That is, the present invention has the following configurations.

(A) (a) 5 to 80 parts by weight of a rubbery polymer, (b) 10 to 90% by weight of an aromatic vinyl monomer, a vinyl cyanide monomer and / or a (meth) acrylic acid alkyl ester. Graft copolymer obtained by graft-polymerizing 95 to 20 parts by weight of a monomer mixture consisting of 90 to 10% by weight of a base monomer and 0 to 40% by weight of another vinyl monomer copolymerizable therewith ( 1 to 99% by weight (based on the sum of components A and B), (B) a polyamide resin (based on the sum of components A and B) 99 to 1% by weight, and (C) an aqueous metal hydroxide solution. , The following formulas (I) and (I
A thermoplastic resin composition added so as to satisfy I) and a method for producing the same.

(Where x is the number of moles of water in the metal hydroxide aqueous solution, y
Is the number of moles of the metal hydroxide in the aqueous metal hydroxide solution, m is the vinyl cyanide monomer and / or (meth) acrylic acid alkyl ester-based monomer residue (A) in (A)
Indicates the number of moles in the composition consisting of + (B). ) Hereinafter, the present invention will be specifically described.

The rubbery polymer (a) which is a constituent of the graft copolymer (A) used in the present invention is preferably one having a glass transition temperature of 0 ° C. or lower, and specifically, polybutadiene and poly (styrene). -Butadiene), poly (acrylonitrile-butadiene) and other diene rubbers, polyisoprene, polychloroprene, polybutyl acrylate and other acrylic rubbers, and ethylene-propylene-diene monomer terpolymers and other rubbery polymers Can be used. Particularly, butadiene or butadiene copolymer is preferred.

(B) Aromatic vinyl monomers include styrene and α-
Methylstyrene, vinyltoluene, o-ethylstyrene, op-dichlorostyrene and the like can be mentioned, but styrene is particularly preferable, and one or more of these can be used.

Examples of the vinyl cyanide-based monomer include acrylonitrile, methacrylonitrile, ethacrylonitrile and the like, and acrylonitrile is particularly preferable.

Examples of the (meth) acrylic acid alkyl ester-based monomer include methyl methacrylate, ethyl methacrylate, propyl methacrylate, methyl acrylate, cyclohexyl methacrylate, chloromethyl methacrylate, acrylic acid-
Examples thereof include 2-hydroxyethyl, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, glycidyl acrylate, and glycidyl methacrylate.

Other copolymerizable vinyl monomers include (meth) acrylamides such as acrylamide, methacrylamide, N-methylacrylamide, N, N-dimethylacrylamide, and α, β such as maleic anhydride and itaconic anhydride. -Imide compounds of α, β-unsaturated carboxylic acids such as unsaturated dicarboxylic acid anhydrides, N-methylmaleimide, Nt-butylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-O-chlorophenylmaleimide And vinyl carboxylic acid esters such as vinyl acetate and vinyl propionate.

In addition, the graft copolymer (A) is (a) rubber polymer 5 to 80 parts by weight, preferably 7 to 75 parts by weight, more preferably 10 to 70 parts by weight, the monomer mixture 95 to 20 parts. Parts by weight, preferably 93 to 25 parts by weight, more preferably 90 to 30 parts by weight by a known polymerization method, for example, continuous the monomer mixture and the polymerization initiator in the above proportion in the presence of a rubbery polymer latex. It can be obtained by a method of emulsion graft polymerization.

If the proportion of the rubbery polymer (a) in the graft copolymer is less than 5 parts by weight, the resulting resin will have poor impact resistance,
If the amount exceeds the weight part, the rubbery polymer becomes poorly dispersed,
It is not practical because it impairs the appearance of the molded article.

Further, if the proportion of the aromatic vinyl-based monomer in the monomer mixture (b) is less than 10% by weight, the moldability is poor, and if it exceeds 90% by weight, the impact resistance and the resistance of the resulting resin are low. It is not preferable because it lowers the chemical properties.

Further, the ratio of the vinyl cyanide-based monomer and the (meth) acrylic acid alkyl ester-based monomer is arbitrary, and if the total ratio of these is less than 10% by weight, the resulting resin is inferior in impact resistance, which is not preferable. On the other hand, if it exceeds 90% by weight, the thermal stability of the copolymer is remarkably lowered, resulting in a molded product having a poor color tone, which is not preferable.

Further, the content of (a) in the total thermoplastic resin composition is 1
It is preferably in the range of 60 to 60% by weight, particularly preferably in the range of 3 to 55% by weight, and further preferably in the range of 5 to 50% by weight. Furthermore, when the weight of the diene rubber in the resin composition is 15% by weight or more, and particularly 15 to 25% by weight, the impact resistance of the resin composition is higher than that of each of the graft copolymer composition and the polyamide resin. Compared to that, it will be dramatically improved.

As the polyamide resin (B) used in the present invention, ε-
Polyamides obtained by ring-opening polymerization of lactams such as caprolactam and ω-dodecalactam, polyamides derived from amino acids such as 6-aminocaproic acid, 11-aminoundecanoic acid and 12-aminododecanoic acid, ethylenediamine, tetramethylenediamine, hexa Methylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4- and 2,4,4-trimethylhexamethylenediamine, 1,3- and 1,4-bis (aminomethyl) cyclohexane, bis (4, 4'-aminocyclohexyl)
Aliphatic, alicyclic, aromatic diamines and adipic acid, such as methane, meta and para-xylylenediamine, speric acid, sebacic acid, dodecanedioic acid, 1,3- and 1,4-cyclohexanedicarboxylic acid, isophthalic acid, Examples thereof include polyamide resins derived from aliphatic, alicyclic and aromatic dicarboxylic acids such as terephthalic acid and dimer acid, and copolymerized polyamide resins and mixed polyamide resins thereof. Of these, polycaproamide (nylon 6), polyundecane amide (nylon 11), polydodecane amide (nylon 12), polyhexamethylene adipamide (nylon 66), and copolymers containing these as the main components are usually used. Polyamide resins are useful.

The above polyamide resins can be used alone or in combination of two or more.

Polyamide resin polymerization method is usually known melt polymerization,
Solid phase polymerization and methods combining these can be employed. The degree of polymerization of the polyamide resin is not particularly limited, and a polyamide resin having a relative viscosity (measured at 25 ° C by dissolving 1 g of the polymer in 100 g of 98% concentration acid at 25 ° C) in the range of 2.0 to 5.0 is arbitrarily selected according to the purpose. it can.

As the (C) metal hydroxide used in the present invention, those represented by the following formula (III) are preferable.

M (OH) or M (OH) ₂ (III) (where M is an element periodic table, the 2nd to 6th periods, I to II)
Represents a group metal. ) Specifically, lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, rubidium hydroxide,
Examples thereof include strontium hydroxide and barium hydroxide, with sodium hydroxide and potassium hydroxide being particularly preferred.

Moreover, these can be used individually or in combination of 2 or more types.

When the above (C) is added to the resin component,
It is necessary to add (C) as an aqueous solution in consideration of dispersibility in the resin component.

The suitable concentration of the aqueous solution (C) is 1 to 45% by weight, more preferably 2 to 45% by weight, and further preferably 3 to 40% by weight. If the concentration exceeds 45% by weight, the amount of heat generated by the dissolution is considerably large depending on the metal species, and the dissolution time becomes long, which is not preferable. On the other hand, if the concentration is less than 1% by weight, the amount of water required to dissolve the amount of the metal hydroxide required in the resin composition is too large, which is not preferable.

The blending ratio of the graft copolymer (A) and the polyamide resin (B) in the thermoplastic resin composition of the present invention is
(A) is 1 to 99% by weight, preferably 2 to 94% by weight, more preferably 5 to 90% by weight, and (B) is 1 to 99% by weight, preferably 6 to 98% by weight, further preferably 10 ~ 95
% By weight. When (A) is less than 1% by weight and (B) exceeds 99% by weight, the resulting resin composition is inferior in impact resistance, and when (A) exceeds 99% by weight and (B) Is less than 1% by weight, chemical resistance and mold transferability are poor, which is not preferable.

Further, the addition amount of the metal hydroxide aqueous solution in the resin composition needs to satisfy the following formulas (I) and (II).

Here, x / m means the amount of water added and y / m means the amount of metal hydroxide added.

That is, with respect to the number of moles (m) of the vinyl cyanide-based monomer and / or (meth) acrylic acid alkyl ester-based monomer residue in (A), the moles of water in the aqueous metal hydroxide solution are used. The number (x) is 0.02 to 0.5 mole ratio, and the number of moles (y) of the metal hydroxide in the metal hydroxide aqueous solution is 1 × 10 ^−4.
~ 0.2 molar ratio.

By adding this aqueous metal hydroxide solution, the nitrile group and / or the ester group in the resin composition are hydrolyzed, and the generated carboxyl group is neutralized by the metal hydroxide.

Here, when the water content of the aqueous metal hydroxide solution to be added is less than 0.02 in terms of the molar ratio of the vinyl cyanide-based monomer and / or the (meth) acrylic acid alkyl ester-based monomer residue, Since the amount of groups produced is small, the compatibility between the graft copolymer and the polyamide resin is insufficient.
On the other hand, when it exceeds 0.5 mol ratio, the graft copolymer component is apt to gel, and a molded product having a good surface condition cannot be obtained.

When the amount of metal hydroxide in the aqueous solution is less than 1 × 10 ^{−4 in} terms of the molar ratio of vinyl cyanide-based monomer and / or (meth) acrylic acid alkyl ester-based monomer residue,
Since the neutralization amount of the carboxyl group is small, a composition having a good surface appearance cannot be obtained, which is not preferable. In addition, 0.2
If it exceeds the molar ratio, the processability of the resin composition is poor, and this is also not preferable.

By adding an appropriate amount of a metal hydroxide aqueous solution, the compatibility of the acrylonitrile-styrene resin and the polyamide resin is improved without adding a polymer compatibilizer, and the resin composition has excellent mechanical properties such as impact resistance. The thing is obtained.

The present invention is a novel compatibilization technique for the two resins, and a significant cost reduction is achieved in that only an inorganic compound is added.

The thermoplastic resin composition of the present invention can be used for other thermoplastic polymers such as styrene / acrylonitrile copolymer, α-
Melt by mixing methylstyrene / acrylonitrile copolymer, α-methylstyrene / styrene / acrylonitrile copolymer, styrene / methyl methacrylate / acrylonitrile copolymer, styrene / acrylamide copolymer, polymethylmethacrylate, etc. Liquidity,
It is also possible to further improve the balance between heat resistance and impact resistance.

For example, when the concentration of the rubbery polymer in the graft polymer (A) is high, a method of adding one or more of the above copolymers such as styrene / acrylonitrile / methyl methacrylate copolymer is generally used. is there.

In addition, depending on the purpose, pigments and dyes, glass fibers, metal fibers, metal flakes, reinforcing agents and fillers such as carbon fibers, heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, lubricants,
Plasticizers, antistatic agents, flame retardants and the like can also be added.

[Examples] Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

AST with 1/2 ″ Izod impact strength as an evaluation of impact resistance
It was measured according to MD 256-56. As an evaluation of molding processability, the resin temperature was increased by a flow tester that increased the melt viscosity.
It was measured under the conditions of 250 to 280 ° C and a load of 50 kg. As an evaluation of heat resistance, the Vicat softening temperature was measured according to ASTM D-1525. Regarding the chemical resistance, the injection-molded square plate was immersed in methanol and gasoline at 23 ° C. for 24 hours, and the square plate surface was visually observed. The surface appearance was measured by measuring the glossiness of the molded article surface.

In addition, the following parts and% represent parts by weight and% by weight, respectively.

Reference Example Graft copolymers A-1 to A-3 were produced by the following formulations.

A-1: polybutadiene latex (rubber particle diameter 0.25μ,
Monomer mixture consisting of 70% styrene and 30% acrylonitrile in the presence of 60 parts (gel content 80%) (solid content equivalent) 40
Part was emulsion polymerized.

The obtained graft copolymer was coagulated with sulfuric acid, neutralized with caustic soda, washed, dried and dried to prepare a powdery graft copolymer (A-1).

A-2: 15 parts of methyl methacrylate in the presence of 40 parts (as solid content) of the polybutadiene latex used in A-1
After emulsion-polymerizing 60 parts of a monomer mixture consisting of 65% styrene and 20% acrylonitrile, a powdery graft copolymer (A-2) was prepared in the same manner as in A-1.

A-3: 20 parts of polybutadiene rubber ("Diene" NF35A, manufactured by Asahi Kasei Co., Ltd.) was dissolved in 70 parts of styrene and 10 parts of acrylonitrile, and then bulk polymerized to obtain a graft copolymer (A-
3) was prepared.

Examples 1 to 9 and Comparative Examples 1 to 5 Aqueous metal hydroxides were added to A-1 to A-3 produced in Reference Examples according to the ratio shown in Table-1, mixed with a Henschel mixer, and then a vented 40 mmφ extruder. Cylinder temperature using
It was extruded at 220 ° C and pelletized.

The obtained pellets were dried with hot air at 80 ° C. for 8 hours or more, and then mixed with a polyamide resin (CM1010, manufactured by Toray Industries, Inc., nylon 6) in the mixing ratio shown in Table 1. This mixture is extruded with a vented 40 mmφ extruder at a cylinder temperature of 250 ° C.,
After pelletizing each, each pellet was subjected to injection molding under the conditions of a molding temperature of 250 ° C. and a mold temperature of 60 ° C. to prepare each test piece. The physical properties thereof were evaluated and the results are shown in Table-1.

Examples 10 to 18 and Comparative Examples 6 to 10 CM3001N (nylon 66, manufactured by Toray Industries, Inc.) was used as a polyamide resin, and the extrusion temperature was 280 ° C. and the molding temperature was 280.
C. and the mold temperature was set to 80.degree. C., and the same conditions as in Examples 1 to 9 were used. The results of measurement of compounding composition and physical properties are shown in the table.
It is shown in FIG.

The following is clear from the examples and comparative examples.

That is, the products obtained by the present invention are all excellent in impact resistance, moldability, heat resistance, chemical resistance and surface appearance. On the other hand, those having a small addition amount of metal hydroxide (Comparative Examples 1 and 6) are not preferable because the surface appearance is inferior. In addition, those with a large amount of added water (Comparative Examples 2 and 7) have high melt viscosity, poor moldability, and poor surface appearance. Further, those containing only metal hydroxide (Comparative Examples 3 and 8) and those containing no metal hydroxide aqueous solution (Comparative Examples 4 and 9) are inferior in impact resistance, which is not preferable. Those containing no polyamide resin (Comparative Examples 5 and 10) are inferior in heat resistance and chemical resistance, which is not preferable.

[Effect of the Invention] The thermoplastic resin composition of the present invention contains the graft copolymer (A), the polyamide resin (B) and the aqueous metal hydroxide solution (C) in a specific ratio, and is particularly suitable. The presence of an appropriate amount of the metal hydroxide aqueous solution at a concentration makes the compatibility of (A) and (B) extremely good.

Further, the thermoplastic resin composition of the present invention has molding processability equivalent to that of the rubber-reinforced acrylonitrile-styrene resin, impact resistance and heat resistance of the polyamide resin, and chemical resistance, so that these properties were utilized. It can be used for various molded products.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display area C08L 77:00) (C08L 55/02 77:00) (C08L 77/00 51:04) (C08L 77/00 55:02) (56) Reference JP-A-2-173142 (JP, A) JP-A-2-127457 (JP, A) JP-A-1-315462 (JP, A) JP-A-64- 56750 (JP, A) JP 60-53550 (JP, A) JP 52-121660 (JP, A)

Claims (4)

(57) [Claims] (A) (A) 5 to 80 parts by weight of a rubbery polymer (b) 10 to 90% by weight of an aromatic vinyl monomer, a vinyl cyanide monomer and / or (meth) 90 to 10% by weight of acrylic acid alkyl ester monomers and 0 to 40% by weight of other vinyl monomers copolymerizable with them
1 to 99% by weight of a graft copolymer (based on the sum of components A and B) obtained by graft-polymerizing 95 to 20 parts by weight of a monomer mixture consisting of (B) polyamide resin (components A and B) 99% to 1% by weight) and (C) an aqueous metal hydroxide solution are represented by the following formulas (I) and (II):
A thermoplastic resin composition, which is added so as to satisfy the above condition. (Where x is the number of moles of water in the metal hydroxide aqueous solution, y
Is the number of moles of metal hydroxide in the aqueous metal hydroxide solution, m is the vinyl cyanide monomer and / or (meth) acrylic acid alkyl ester monomer residue (A) in (A)
Indicates the number of moles in the composition consisting of + (B). ) 2. (A) 5 to 80 parts by weight of a rubbery polymer (b) 10 to 90% by weight of an aromatic vinyl monomer, vinyl cyanide monomer and / or (meth) 90 to 10% by weight of acrylic acid alkyl ester monomers and 0 to 40% by weight of other vinyl monomers copolymerizable with them
1 to 99% by weight of a graft copolymer (based on the sum of components A and B) obtained by graft-polymerizing 95 to 20 parts by weight of a monomer mixture consisting of (B) polyamide resin (components A and B) 99% to 1% by weight and (C) an aqueous metal hydroxide solution represented by the following formulas (I) and (II)
A method for producing a thermoplastic resin composition, characterized in that the thermoplastic resin composition is added and mixed in a ratio that satisfies the above condition. (Where x is the number of moles of water in the metal hydroxide aqueous solution, y
Is the number of moles of metal hydroxide in the aqueous metal hydroxide solution, m is the vinyl cyanide monomer and / or (meth) acrylic acid alkyl ester monomer residue (A) in (A)
Indicates the number of moles in the composition consisting of + (B). ) 3. The concentration of the aqueous metal hydroxide solution is 1 to 45% by weight.
The method for producing a thermoplastic resin composition according to claim 2, wherein 4. The thermoplastic resin according to claim 2 or 3, characterized in that the metal hydroxide is a hydroxide of a metal of groups I to II with a period of 2 to 6 of the periodic table of the elements. A method for producing a resin composition.