JPH04173862A - Resin composition - Google Patents

Abstract

PURPOSE:To provide the title composition excellent in heat resistance, impact resistance etc., suitable for automotive parts, electrical and electronic instrument parts etc., comprising a specific styrene-based multicomponent copolymer, polyamide resin and core shell-type acrylic rubber at specified proportion. CONSTITUTION:The objective composition comprising (A) 10-60 (pref. 15-55)wt.% of a styrene-based multicomponent copolymer produced from (1)>=20wt.% of at least styrene-based compound, (2) 5-60wt.% of an imide compound of alpha,beta-unsaturated dicarboxylic acid and (3) 0.1-30wt.% of an unsaturated carboxylic acid and/or unsaturated dicarboxylic acid anhydride, (B) 30-80 (pref. 35-70)wt.% of a polyamide resin and (C) 1-15 (pref. 5-15)wt.%, based on the total weight of the components B and C, of a core shell-type acrylic rubber wherein the shell part is modified with carboxylic acid.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a highly rigid resin composition with excellent impact resistance.

More specifically, the present invention relates to a resin composition with an excellent balance of physical properties, such as high rigidity, excellent impact resistance, and heat resistance, which is suitable as a material for automobile parts, electric/electronic equipment parts, etc.

[Conventional technology]

Polyamide resin is used as an ensuring plastic due to its excellent physical and chemical properties.
It is widely used in automobile parts, electrical equipment parts, electronic equipment parts, mechanical parts, etc.

However, polyamide resins have the drawback of not having sufficient impact resistance. In order to improve this point, a composition has been proposed in which a modified polyolefin obtained by grafting α,β-unsaturated carboxylic acids onto a polyamide resin is blended (JP-A-50-96442 and JP-A-52-151348). , No. 55-9661, No. 55-
No. 9962, No. 55-1135922, No. 57-82
No. 96, No. 57-200948, etc.), and some of these compositions are in practical use.

[Invention or problem to be solved]

However, although these compositions have improved impact resistance, they not only have poor heat resistance;
There is also the problem that the rigidity decreases, and furthermore, the rigidity decreases significantly when moisture is absorbed.

The present invention overcomes the drawbacks of such conventional compositions and provides a resin composition with an excellent balance of physical properties, such as high rigidity, excellent impact resistance and heat resistance. It was made for the purpose of

[Means for Solving the Problems] As a result of extensive research, the inventors found that a composition consisting of a styrene multi-component copolymer, a polyamide resin, and a core-shell type acrylic rubber is suitable for the above purpose, The present invention has now been completed. That is, the present invention provides (A) a styrenic multi-component copolymer comprising at least a styrene compound, an imide compound of an α,β-unsaturated dicarboxylic acid, and an unsaturated carboxylic acid and/or an unsaturated dicarboxylic acid anhydride; ( B) A composition consisting of a polyamide resin and (C) a core-shell type acrylic rubber whose shell portion is modified with a carboxylic acid, and the proportions of components (A) and (B) in the composition are 10 to 60% by weight, respectively. % and 30 to 80% by weight, and the proportion of component (C) in the total amount of components (B) and (C) is 1 to 15% by weight.
The copolymerization ratio of unsaturated carboxylic acid and unsaturated dicarboxylic acid anhydride in component (A) is 0.1 to 30% by weight as their total amount, and the copolymerization ratio of imide compound is 5%. 0 to 60% by weight, or the copolymerization ratio of the styrene compound is at least 20% by weight.

The present invention will be explained in detail below.

(A) Styrenic multi-component copolymer The styrene compound which is the copolymerization component of component (A) used in the present invention is styrene or a derivative thereof, and the derivatives include α-methylstyrene, 0-methylstyrene. , m-methylstyrene, p-methylstyrene, chlorostyrene and bromstyrene.

Further, examples of imide compounds of α,β-unsaturated dicarboxylic acids include those represented by formula (1) or formula (1).

R, -C=C-R20N ○ In the formula (I), R, R and R3 may be the same or different, and are a hydrogen atom or a hydrocarbon group having at most 12 carbon atoms.

Representative examples of the imide compounds include maleimide, N-
Phenylmaleimide, N-methylphenylmaleimide,
Examples include N-ethylphenylmaleimide, N-cyclohexylmaleimide, N-laurylmaleimide, and Np-chlorophenylmaleimide.

Furthermore, as an unsaturated carboxylic acid, the number of carbon atoms or at most 3
Mention may be made of α,β-unsaturated monocarboxylic acids having 0 carbon atoms, preferably 25 or less carbon atoms, and α,β-unsaturated dicarboxylic acids having at most 30 carbon atoms, preferably 25 carbon atoms or less. Representative examples of preferred unsaturated carboxylic acids include acrylic acid, methacrylic acid, maleic acid, fumaric acid, and itaconic acid.

Preferred unsaturated dicarboxylic anhydrides include the aforementioned α,β-unsaturated dicarboxylic acid anhydrides, representative examples of which include maleic anhydride, fumaric anhydride, itaconic anhydride, etc. It will be done.

Component (A) can be produced by any of the commonly used methods such as aqueous suspension polymerization, emulsion polymerization, solution polymerization, and bulk polymerization, and these polymerization methods are generally well known.

The copolymerization ratio of the imide compound in component (A) is 5.
The content is 0 to 60% by weight, preferably 5.0 to 55% by weight, and particularly preferably 5.0 to 50% by weight. If the copolymerization ratio of the imide compound in component (A) is less than 5.0% by weight, heat resistance will be insufficient. On the other hand, if it exceeds 60% by weight, moldability and mechanical properties are poor.

In addition, the copolymerization ratio of unsaturated carboxylic acid and unsaturated dicarboxylic acid anhydride is 0.1 to 30% by weight as their total amount, preferably 0.1 to 25% by weight, particularly 0.5 to 20% by weight. % is preferred. If the copolymerization ratio of unsaturated carboxylic acid and unsaturated dicarboxylic acid anhydride in component (A) is less than 0.1% by weight as a total amount of the unsaturated carboxylic acid and unsaturated dicarboxylic acid anhydride, (
B) Poor compatibility with ingredients. On the other hand, if it exceeds 30% by weight, moldability decreases. The copolymerization ratio of the styrene compound in component (A) is at least 20% by weight, and if it is less than 20% by weight, the moldability of the resulting composition is poor.

Component (A) of the present invention further includes unsaturated nitrile compounds (for example, acrylonitrile, methacrylonitrile).
A copolymer of at most 30% by weight of an ester of acrylic acid or methacrylic acid (for example, methyl acrylate, methyl methacrylate) as a copolymerization component may also be used.

In addition, producing component (A) containing a high proportion of unsaturated carboxylic acid and/or unsaturated dicarboxylic acid anhydride,
Component (A) and a styrenic copolymer containing no unsaturated carboxylic acid and/or unsaturated dicarboxylic acid anhydride are mixed in the above proportions when producing the final composition. You can.

Melt index of component (A) of the present invention (JISK7
210, measured at a temperature of 250°C and a load of 5.0 kg, hereinafter referred to as MI] is usually 0.01 to O
g/10 minutes, preferably 0.05 to 100 g/10 minutes, particularly preferably 0.1 to 50 g/10 minutes.

When the M I is less than 0.01 g/10 minutes, the moldability of the resulting composition is poor. On the other hand, if it exceeds 100 g/10 minutes, the mechanical strength is poor.

(B) Polyamide resin The component (B) in the present invention is described in Japanese Patent Application Laid-Open No.
．． The polyamide resins described in Publication No. 51547, page 3, lower left column, line 17 to page 4, upper left column, line 7, can be used.

(C) Acrylic Rubber The acrylic rubber in the present invention is a core-shell type. The core part is mainly composed of an acrylic ester polymer, for example, it is made by polymerizing an acrylic ester monomer and a small amount of a crosslinking monomer, and has a glass transition temperature of 130°C.
Examples include the following rubbery polymers. As the acrylic acid ester monomer, one having an alkyl group preferably having 1 to 12 carbon atoms, most preferably 2 to 8 carbon atoms is used. Further, examples of the crosslinkable monomer include compounds having two or more double bonds such as butylene glycol diacrylate and hexane diacrylate. Furthermore, a monomer capable of copolymerizing with acrylic acid ester,
For example, acrylic esters copolymerized with styrene, α-methylstyrene, vinyl halides, vinylidene halides, acrylonitrile, methyl methacrylate, etc. can also be used.

On the other hand, the shell portion is made of a hard polymer, such as polymethyl methacrylate, polystyrene, or a copolymer of styrene and acrylonitrile. The proportion of the core portion in the acrylic rubber is 50 to 90% by weight.
It is. If the proportion of the core portion is less than 50% by weight, the resulting composition will not have good impact resistance, and if it exceeds 90% by weight, the heat resistance will decrease, which is not preferable.

Moreover, the average particle size of the acrylic rubber is 0.02 to 1.0 microns. If the average particle size is outside the above range, impact resistance will be poor.

Furthermore, in the present invention, it is necessary that the shell portion of the acrylic rubber be modified with carboxylic acid.

As the carboxylic acid, α,β-unsaturated carboxylic acids such as acrylic acid and methacrylic acid are used, and these carboxylic acids are obtained by copolymerizing the monomer that will become the shell portion. The proportion of carboxylic acid in the shell is 01
~30% by weight. Proportion of carboxylic acid or 01 heavy ffi
If it is less than 96, the resulting composition will have poor impact resistance. On the other hand, if it exceeds 30% by weight, the viscosity of the resulting composition will increase significantly and moldability will deteriorate.

(D) Composition ratio The ratio of component (A) in the composition of the present invention is 10 to 6.
0% by weight, preferably 15-55% by weight.

If the proportion of component (A) is less than 10% by weight, the resulting composition will have poor heat resistance and stiffness upon moisture absorption, which is undesirable.

Moreover, if it exceeds 60% by weight, the chemical resistance and four-sided impact resistance of the resulting composition will deteriorate, which is not preferable.

Further, the proportion of component (B) in the composition of the present invention is 3
0 to 80% by weight, preferably 30 to 75% by weight,
In particular, 35-70-6 is suitable. If the proportion of component (B) is less than 30% by weight, the resulting composition will have poor chemical resistance. On the other hand, if it exceeds 80 weight 9.6, the resulting composition will have a poor balance between heat resistance, impact resistance, and rigidity (flexural modulus). Moreover, the rigidity decreases significantly due to moisture absorption.

Furthermore, (
The proportion of component C) is 1 to 15% by weight, preferably 5% by weight.
~15% by weight. If the proportion of component (C) is less than 1% by weight, the impact resistance of the resulting composition will deteriorate, which is undesirable. On the other hand, if it exceeds 15% by weight, heat resistance and rigidity decrease, which is not preferable.

(E) Production and molding method of resin composition The resin composition of the present invention can achieve its purpose by uniformly blending the components (A), (B), and (C) described above.

There are no particular restrictions on the blending method (mixing method).
Any method commonly used in the field of synthetic resins may be applied. Mixing methods include tri-blending using commonly used mixers such as Henschel mixers, tumblers and ribbon blenders, and melting using mixers such as open rolls, extrusion mixers, kneaders and Banbury mixers. I can give you a method of mixing it while doing so. Among these mixing methods, two or more of these mixing methods may be used in combination to obtain a composition with a uniform layer (for example, after tri-blending in advance, the mixture is melt-mixed).

Among these, even when using tri-blend together, or when using one or more melt-kneading methods,
When producing a molded product by the molding method described below, it is preferable to use a pelletizer to produce a pellet.

Furthermore, in producing the composition, two or a portion of these components may be premixed, and the resulting mixture may be mixed with the remaining components.

In producing the resin composition of the present invention, stabilizers against heat, oxygen and light, flame retardants, fillers, colorants, which are widely used in the field of synthetic resins and synthetic rubbers,
Additives such as lubricants, plasticizers, and antistatic agents may be added depending on the intended use of the composition, to the extent that they do not essentially impair the properties of the composition of the present invention.

Of the above-mentioned mixing methods, both melt-kneading and molding using the molding method described below must be carried out at a temperature that melts the polymeric substance used. but,
If carried out at high temperatures, the polymeric material will undergo thermal decomposition and deterioration. For these reasons, the temperature is generally 180 to 350℃.
(preferably 200 to 320°C).

The composition of the present invention may be molded into a desired shape by applying molding methods commonly practiced in the field of synthetic resins, such as injection molding, extrusion molding, compression molding, and blow molding. Alternatively, after forming the sheet into a sheet using an extrusion molding machine, the sheet may be formed into a desired shape by a secondary processing method such as a vacuum forming method or a pressure forming method.

[Examples and comparative examples]

Hereinafter, the present invention will be explained in more detail with reference to Examples.

In the Examples and Comparative Examples, Izod impact strength was measured with a notch at a temperature of 23° C. according to ASTM D256. In addition, the heat distortion temperature is ASTM
Measured according to D648 at a stress of 18.6 kg/c-.

Furthermore, the flexural modulus is 23 according to ASTM D790.
Measured at a temperature of °C. In the moisture absorption test, the test piece was immersed in boiling water at 100°C for 30 minutes, and then the flexural modulus was measured.

In addition, in the examples and comparative examples, (A) used
, (B) and (C) The manufacturing method, type, physical properties, etc. of each component are shown below.

[(A) Styrenic multi-component copolymer]

As component (A), one manufactured as follows was used.

1 (eoooo g of water in the IQ autoclave, 240
0 g styrene (ST), 680 g acrylonitrile (AN), 800 g N-phenylmaleimide (N-P
MI) and 120 g of methacrylic acid (MAA), as well as 8 g of lauryl peroxide and 96 g of tertiary-butyl peroxylaurate as initiators, and 8 g of tertiary-butyl peroxide as chain transfer agent. In addition, as a suspension stabilizer, fliOg triphosphoric acid and 09 g of sodium todenrugensulfonate were added, and polymerization was carried out at a temperature of 80° C. for 2 hours with stirring. Then, the temperature of the polymerization system was raised to 120°C, and after polymerization was carried out at this temperature for 3 hours, the polymerization system was allowed to cool to room temperature. As a result, about 3500 g of pale yellow powder was obtained. When the obtained powder was determined by infrared absorption spectroscopy (solution method), it was found that ST.
AN: N-PMI: MAA-60: 17.
The ratio was 20:3. The heat distortion temperature of the obtained powder (polymer) was 130° C., and the Ml was 16.2 g/10 minutes. This is referred to as copolymer (1).

For comparison, polymerization was carried out in the same manner as for copolymer (1) except that the entire amount of MAA used in producing copolymer (1) was replaced with AN. About 3500 g of the obtained powder was analyzed in the same manner as copolymer (1), and the weight ratio was ST:AN:N-PMI-60:
20: It was 20. The heat distortion temperature of the obtained powder (polymer) was 134.2°C, and the Ml was 17.8g.
/10 minutes. This is referred to as copolymer (2).

[(B) Polyamide resin]

In addition, as component (B), relative viscosity η (in concentrated sulfuric acid,
mj constant at 30°C) or nylon 66 (hereinafter P
A (hereinafter referred to as P A (a)) and η 2,7 (hereinafter referred to as P A (b)) were used.

[(C) Core-shell type acrylic rubber] Furthermore, as a core-shell type acrylic rubber whose shell portion is modified with carboxylic acid, Staphyloid I M
-301 (manufactured by Takeda Pharmaceutical Co., Ltd.) was used. The average particle size of this rubber is 0.3 microns. Add this to rubber (1
).

As comparative examples, rubber (1) whose shell was not modified with carboxylic acid (rubber (2)) and EPR rubber modified with maleic anhydride (rubber (3)) were used.

Examples 1 to 4, Comparative Examples 1 to 4 Each component whose blending amount is shown in Table 1 was charged into a Henschel mixer, and triblended for 5 minutes. A pellet (composition) was produced by kneading each of the obtained mixtures using a twin-screw extruder (diameter: 40 m11) set at 270°C. Each of the obtained pellets was vacuum dried at a temperature of 80°C for 48 hours, and then injection molded using an injection molding machine set at 270°C to prepare test pieces for measurement.

Each test piece was subjected to a heat resistance test, a moisture absorption test, and measurements of Izot impact strength and flexural modulus. The results are shown in Table 2.

Table 2 ■) Notched 〔Effect of the invention〕 The resin composition of the present invention exhibits the following effects.

(1) Excellent heat resistance.

(2) Decrease in rigidity due to moisture absorption is small.

(3) Impact resistance is poor.

(4) Good rigidity (flexural modulus).

The resin composition of the present invention can be used in a wide variety of ways to achieve the effects described above. Typical uses are shown below.

(1) Automotive exterior panels such as fenders and reactor panels.

(2) Automotive parts such as oil covers and radiator grills.

(3) Mechanical and electrical parts such as connectors and transformer cases.

Claims (1)

[Scope of Claims] (A) A styrenic multi-component copolymer comprising at least a styrene compound, an imide compound of an α,β-unsaturated dicarboxylic acid, and an unsaturated carboxylic acid and/or an unsaturated dicarboxylic acid anhydride; It is a composition consisting of (B) a polyamide resin and (C) a core-shell type acrylic rubber whose shell portion is modified with carboxylic acid, and the proportions of components (A) and (B) in the composition are 10 to 60% respectively. % by weight and 30 to 80% by weight, and the proportion of component (C) in the total amount of components (B) and (C) is 1 to 15% by weight.
The copolymerization ratio of unsaturated carboxylic acid and unsaturated dicarboxylic acid anhydride in component (A) is 0.1 to 20% by weight as their total amount, and the copolymerization ratio of imide compound is 5. .0 to 60% by weight, but the copolymerization proportion of the styrenic compound is at least 20% by weight.