JPS63241058A - Thermoplastic rein composition - Google Patents

Abstract

PURPOSE:To form a thermoplastic resin compsn. having well-balanced properties among resistance to impact, heat and weather, moldability and coatability, by blending a polyphenylene ether with a specific maleimide resin and a styrene polymers. CONSTITUTION:This thermoplastic resin compsn. is formed from 5-40wt.% polyphenylene ether (A), 10-95wt.% maleimide copolymer (B) having an N- substd. maleimide content of 1-15wt.% obtd. by polymerizing an N-substd. maleimide with an arom. vinyl compd. and optionally, other copolymerizable monomer in the presence or absence of rubber, and 0-65wt.% styrene polymer (C). Preferred examples of the arom. vinyl compd. in the component B are styrene and alpha-methylstyrene. Examples of other copolymerizable monomer are vinyl cyanide compds. and (meth)acrylic esters.

Description

DETAILED DESCRIPTION OF THE INVENTION a. Industrial fields of application The present invention relates to heat resistance, moldability, particularly weather resistance, paintability,
The present invention relates to a thermoplastic resin composition having excellent practical impact resistance, and more particularly to a thermoplastic resin composition comprising polyphenylene nityl, a maleimide resin, and a styrene resin.

b. Prior Art Polyphenylene ether is widely known as a resin with excellent heat resistance, mechanical properties, and electrical properties, but it has low impact resistance, poor processability, weather resistance, and paintability, and is difficult to use at high temperatures. It has drawbacks such as thermal discoloration and gelation. Therefore, it is rarely used alone, and is usually used as a modified polyphenylene ether resin composed of a composition with polystyrene or rubber-modified polystyrene.

This modified polyphenylene ether resin has excellent mechanical properties, electrical properties, processability, etc., and is therefore widely used in automobile parts, office equipment, electrical appliance parts, and the like.

However, although the impact resistance and moldability are improved, the paintability is not sufficient, and furthermore, the heat resistance, which is an excellent feature of polyphenylene ether resin, is sacrificed. These drawbacks are a major obstacle when using the above-mentioned modified polyphenylene ether resin in applications that take advantage of the characteristics of polyphenylene ether resin.

In order to improve heat resistance, methods have been used to increase the content of polyphenylene ether.

However, although heat resistance is improved, weather resistance, moldability,
It has the disadvantage of poor impact resistance.

In this way, conventional modified polyphenylene ether resins
Impact resistance, heat resistance, moldability, and weather resistance.

It had the disadvantage that the physical property balance of paintability was not sufficient.

Problems to be Solved by the C0 Invention The inventors of the present invention have conducted extensive studies on polyphenylene ether compositions with an excellent balance of physical properties including impact resistance, heat resistance, moldability, weather resistance, and chemical resistance, and have found a surprising result. In particular, when polyphenylene ether is blended with a maleimide resin or styrene resin with a low maleimide content in a specific location,
Excellent impact resistance.

It was discovered that a thermoplastic resin composition having a well-balanced physical property of heat resistance, moldability, weather resistance, and paintability can be obtained, and the present invention was achieved based on this knowledge.

Means for solving the d0 problem The present invention is based on (A) 5 to 40% by weight of polyphenylene ether.
, (B) in the presence or absence of rubber, N-1 ft (
N-substituted maleimide, an aromatic vinyl compound, and if necessary, other copolymerizable monomers are polymerized, and the content of N-substituted maleimide in the resin component is 1 to 1.
The present invention provides a thermoplastic resin composition comprising 10 to 95% by weight of a maleimide copolymer (15% by weight) and 0 to 65% by weight of (C) a styrene resin.

The polyphenylene ether (a) used in the present invention is obtained by oxidative coupling polymerization of at least one phenol compound represented by the general formula in the presence of a known catalyst.

Particularly preferred among the phenol compounds are those represented by the general formula, and specific examples (X) of the most preferred phenol compounds include 2,6-dimethylphenol, 2,6-dimethylphenol, 2 -Methyl-6-ethylphenol, 2-methyl-6-allylphenol, 2-methyl-6-phenylphenol, 2
, 6-diphenylphenol, 2,6-sibutylphenol, 2-methyl-6-propylphenol, 2,3.
Examples include 6-dolimethylphenol and 2,3-dimethyl-6-ethylphenol.

On the other hand, specific examples (Y) of other preferred phenol compounds include 2,3.6-dolimethylphenol, 2,3-
Dimethyl-6-ethylphenol, 2.3.6-driethylphenol, 2,3.6-driprovirphenol, 2,6-dimethyl-3-ethylphenol, 2,6-
It is dimethyl-3-propylphenol. these(
X) and (Y) may be polymerized alone, or may be a copolymerization of (X) and (Y).

In the case of copolymerization of (X) and (Y), there are no particular restrictions on the ratio of each component, but the preferred content of (Y) is 1 to 20 mol%, more preferably 3 to 15 mol%. The intrinsic viscosity [η] (30"C in chloroform) of polyphenylene ether (a) is not particularly limited, but is preferably 0.2 to 1 dll/g, more preferably 0.3 to 1 dll/g.
0,7 dQ/g.

The amount of polyphenylene ether blended in the thermoplastic resin composition of the present invention is 5 to 40% by weight, preferably 7% by weight.
It is preferably 10 to 30% by weight, preferably 10 to 30% by weight. If the amount of polyphenylene ether is less than 5% by weight, no remarkable effect on improving heat resistance is observed, and when it exceeds 40% by weight, no effect on improving processability, light resistance, or paintability is observed.

The amount of N-substituted maleimide used in the copolymerization components (excluding the rubbery polymer component) of the maleimide copolymer (hereinafter also referred to as copolymer (b)) used in the present invention is 1
~15% by weight, preferably 2-10% by weight, more preferably 2-8% by weight. If it is less than 1% by weight, it is not preferable because the heat resistance and paintability, which are the objectives of the present invention, decrease.

Moreover, if it exceeds 15% by weight, it is not preferable because the practical impact resistance, which is the object of the present invention, decreases, but if it is in the range of 2 to 8% by weight, a product with excellent heat resistance and paint resistance can be obtained.

On the other hand, the aromatic vinyl compound is 85 to 99% in the copolymer component.
% by weight, preferably 90-98% by weight.

More preferably, it is used in an amount of 92 to 98% by weight. If the aromatic vinyl compound is less than 85% by weight, the practical impact resistance, which is the objective of the present invention, will be lowered, and if it exceeds 99% by weight, the heat resistance, which is the objective of the present invention, will be lowered.

The copolymer (b) may be a copolymer of a monomer that copolymerizes with the above monomer in addition to the above monomer components, and the copolymerizable monomer is 55 It is used in an amount of at most 40% by weight, more preferably at most 14% by weight. Examples of the copolymerizable monomer include vinyl cyanide compounds, acrylic esters, and methacrylic esters.

The N-substituted maleimide used in the present invention includes N-
These include phenylmaleimide, N-methylmaleimide, N-ethylmaleimide, Nt-butylmaleimide, N-cyclohexylmaleimide, Np-chlorophenylmaleimide, N-naphthylmaleimide, and the like. Especially N-
Phenylmaleimide, N-cyclohexylmaleimide,
N-.

-Methylphenylmaleimide and the like are preferably used.

Aromatic vinyl compounds used in the present invention include styrene, 0-methylstyrene, m-methylstyrene, p-
Methylstyrene, chlorstyrene.

Dichlorostyrene, bromstyrene, dibromstyrene, α-methylstyrene, α-ethylstyrene, methyl-
Examples include α-methylstyrene, dimethylstyrene, and vinylnaphthalene. Among these, styrene, p-methylstyrene, and α-methylstyrene are preferred, and styrene, α-methylstyrene, or a mixture thereof is more preferred.

Rubbers include polybutadiene, polyisoprene, styrene-butadiene copolymer, diene rubber such as nitrile rubber, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, non-diene rubber such as acrylic rubber, etc. can be used. The amount of rubber used is the copolymer (
b) Medium O~60% by weight, more preferably O~
It is preferably 0 to 40% by weight with respect to 45% weight.

The amount of copolymer (b) used is 10 to 95% by weight.

Preferably 15 to 90% by weight, more preferably 20 to 90% by weight
It is 80% by weight. When it is less than 10% by weight, the desired weather resistance and paintability cannot be obtained, and when it exceeds 95% by weight, heat resistance decreases.

The copolymer (b) may generally be produced by any method such as solution polymerization, suspension polymerization, or emulsion polymerization.

Further, the intrinsic viscosity [η] of the copolymer (b) is 0.05 to 0.
5 (30° C. in methyl ethyl ketone) dll/g.

The styrenic resin (c) of the present invention is a rubber-modified resin obtained by copolymerizing a monomer containing an aromatic vinyl compound as a main component in the presence of a polymer containing an aromatic vinyl compound as a main component and/or rubber. It is a styrene resin.

The amount of styrene resin (Q) used is 0 to 65% by weight, preferably 0 to 60% by weight, and more preferably 0 to 60% by weight.
~55% by weight. If it exceeds 65% by weight, it is not preferable because the heat resistance, which is the objective of the present invention, decreases.

As the aromatic vinyl compound, those listed for copolymer (b) can be used.

Monomers copolymerizable with aromatic vinyl compounds include vinyl cyanide compounds, such as acrylonitrile, (meth)
Examples include acrylic acid esters.

These copolymerizable monomers can be used depending on the purpose. It is preferable to use a vinyl cyanide compound because a composition with excellent chemical resistance and paintability can be obtained.

Among copolymers containing an aromatic vinyl compound and cyanide, the composition of the copolymer is a mixture of copolymers having different amounts of vinyl cyanide bond. The composition distribution of the vinyl cyanide compound in such a copolymer (mixture) is as follows: The copolymer component is 1 to 50% by weight.

(b) The vinyl cyanide compound has a binder content of 10% by weight or more and a copolymer component with a composition of less than 20% by weight from 1 to 70%.
(c) Binding content of vinyl cyanide compound is 20% by weight
In the above, the copolymer component with a composition of less than 40% by weight is 5 to 9
0% by weight and a copolymer component having a composition of 40% by weight or more of (d) vinyl cyanide compound, and the average bond of the vinyl cyanide compound in the copolymer. The implication is 10-40% by weight.

The rubber used in rubber-modified styrenic resins contains a polymer of conjugated diene monomers and/or a conjugated diene as essential components, and vinyl cyanide compounds, aromatic vinyl compounds, (meth)acrylic esters, ( 0, which is a rubber obtained by copolymerizing with at least one type of meth)acrylic acid.
For example, polybutadiene rubber, styrene butadiene rubber,
Examples include polyisoprene rubber, butadiene acrylonitrile rubber, and chloroprene rubber. Examples of the non-diene rubber include ethylene propylene rubber, ethylene propylene non-conjugated diene rubber, butyl rubber, acrylic rubber, chlorinated polyethylene, and butadiene copolymerized acrylic rubber.

As the monomer component that polymerizes in the presence of rubber, the above-mentioned monomer components can be used, and the same effects as described above can be obtained when a vinyl cyanide compound is coexisting.

The compositional distribution of the vinyl cyanide compound in the total free polymer (methyl ethyl ketone soluble portion) in the rubber-modified styrenic resin is preferably within the above-mentioned range.

Furthermore, an aromatic vinyl compound-conjugated diene block copolymer (referred to as a block copolymer) can be added if necessary.

Addition of a block copolymer is preferred because it provides even better impact resistance and weld strength. The amount added is preferably 2 to 30% by weight based on the total composition of the present invention in order to exhibit the effect of addition.

Preferred block copolymers have the following general formula.

(A-B)+n and/or A-B-A and/or (
A-B)nX In the formula, A is a polymer block of an aromatic vinyl compound, and as the aromatic vinyl compound, those shown above apply. B is a block copolymer of a conjugated diene, and the conjugated diene is preferably butadiene or isoprene.

m is an integer of 1 or more, preferably 1 to 4, or a residue of a coupling agent, and n is an integer of 2 to 6, preferably 3 to 6.

The content of wholly aromatic vinyl compounds in the block copolymer is 2
5 to 95% by weight, preferably 28 to 90% by weight.

Methods for preparing the thermoplastic resin composition of the present invention include: (1) A method in which each component is dissolved in an organic solvent, swollen, and mixed.

■ A method in which each component is mixed using a mixer, etc., then melted and mixed using an extruder, and then pelletized.

(2) A method in which the powder mixture recovered using a non-solvent in (2) is melt-mixed using an extruder and then pelletized.

■ A method in which a thermoplastic resin, styrene resin, polyphenylene ether, etc. is further added to the pellets of (■), mixed in a mixer, etc., and then melted and mixed using an extruder and then pelletized.

There is a method in which the pellets or powders of (1) and (2) to (3) are used alone or in a mixture, or each component is further added and mixed, and then a molded article is obtained using an injection molding machine.

Further, it is also possible to use known mixing equipment such as a Banbury or a kneader in each of the above methods.

Further, in the composition of the present invention, other polyethylene,
A composition may be obtained by adding and mixing a thermoplastic resin such as polypropylene, polycarbonate, polyamide, polyester, or acrylic resin, and melt-mixing the mixture using an extruder.

The thermoplastic resin composition of the present invention can be used as various molded products by injection molding, sheet extrusion, vacuum molding, irregular molding, foam molding, and the like.

When using the thermoplastic resin composition of the present invention, commonly used antioxidants, ultraviolet absorbers, lubricants, flame retardants, antistatic agents, blowing agents, glass fibers, etc. can be added.

The thermoplastic resin of the present invention can be suitably used for automobile parts, electrical products, household goods, various industrial goods, and the like.

e. Examples Next, the present invention will be explained in more detail with reference to Production Examples and Examples, but these are merely illustrative and do not limit the content of the present invention. Note that parts and % on each side below indicate flt parts and weight %, respectively.

Production Examples Polyphenylene ether used in Examples and Comparative Examples was obtained by the following method.

(1) Production of polyphenylene ether 1 After thoroughly purging the inside of the stainless steel reaction vessel equipped with an oxygen suction device, a cooling coil, and a stirrer at the bottom of the reactor, cupric bromide 53.6 g, 1110 g of di-n-butylamine, and 8.75 kg of 2,6-xylenol dissolved in 40Q toluene were added. After stirring to make a homogeneous solution.

Polymerization was carried out for 120 minutes while rapidly blowing oxygen into the reaction vessel. During the polymerization, water was circulated through a cooling coil to maintain the internal temperature at 30°C. After the polymerization was completed, 30 M of toluene was added, and a 20% aqueous solution of 430 g of disodium ethylenediaminetetraacetate dissolved in water was added to stop one reaction.

Next, the polymer solution phase was taken out by centrifugation. While vigorously stirring this polymer solution phase, methanol was gradually added to form a slurry. After being separated by filtration, the polymer was thoroughly washed with methanol, further separated by filtration, and then dried to obtain Polymer A-1.

1) 2A Instead of the 2,6-xylenol used in the production of Polymer A-1, 2,6-xylenol/2,3゜6-dolimethylphenol = 90/10 (molar ratio) was used. Polymer A-2 was obtained.

(2) Method for producing maleimide copolymers 1) Method for producing maleimide copolymers B-1 to B-6 Solution polymerization method using the monomer components shown in Table 1 and using toluene as a solvent The polymerization was almost completed. Maleimide copolymers B-1 to B-6 shown in Table 1 were obtained.

2) Manufacturing method of maleimide copolymer B-7 Average particle size: 2,700 people Polybutadiene latex (solid content): 40
in the presence of 0.1 part of diisopropylbenzene hydroperoxide and 0.110.000310.2 parts of sodium ethylenediaminetetraacetate/ferrous sulfate heptahydrate/sodium formaldehyde sulfoxylate as an initiator. 3 parts of N-phenylmaleimide in 57 parts of styrene
The monomer mixture in which 1 part was dissolved was subjected to emulsion polymerization continuously for 2 hours at a polymerization temperature of 70°C. Polymerization was almost complete.

Rubber modified maleimide copolymer B-7 shown in Table 1 was obtained.

(3) Method for producing styrene resin Styrene was polymerized by solution polymerization to obtain polystyrene C-,1.

Rubber-modified styrene resin C-2 was obtained by bulk polymerization using 90 parts of styrene in the presence of 10 parts of polybutadiene rubber.

Examples and Comparative Examples According to the composition ratios in Table 2, each m polymer was mixed,
After extruding into pellets using a twin-screw kneading extruder at a temperature of 260 to 300 degrees Celsius, they are thoroughly dried and made into test pieces for measuring impact resistance and heat resistance using an injection molding machine at 240 to 280 degrees Celsius. Table 2 shows the results of molding and measurement according to the test method below.

Evaluation method ■ After annealing the heat-resistant molded product at 110°C for 2 hours, AST
Thickness 174' according to M D648, 261 ps
The heat distortion temperature was measured at i.

■ Impact resistance (Izot impact strength) Measured with a thickness of 1741 notches according to ASTM D256.

■ Practical impact resistance (falling weight strength) A striking frame (12,
7 mm) and a saucer (43+ nm in diameter) to determine the impact energy.

■ Molding processability Using Takara Kogyo's melt indexer, JISK72LO
The melt flow index (MFR) (g/10 m1n) was measured at a cylinder temperature of 280° C. and a load of LO kg according to .

■ Paintability To evaluate paintability, samples were painted under the following conditions and their appearance was evaluated.

Coating conditions Paint FZ Nikryl X-D and thinner 0R-90ONα411 manufactured by Tanabe Kagaku ■ were used.

Paint/Thinner-400/120 Setting time 10 minutes Baking drying 80℃, 20 minutes Film thickness
25-30 μm Evaluation Method The appearance was visually judged and the results are shown in Table 3 based on the following criteria.

○: Good ×: Poor ■ Weather resistance fade meter (63° C., no rain) The degree of change in color tone after 300 hours is measured with a color difference meter (Suga Test Instruments ■).

The larger the value, the greater the change in color tone, and therefore the worse the weather resistance.

Examples 1 to 9 The thermoplastic resin compositions of the present invention have the physical properties targeted by the present invention.

Comparative Example 1: This is an example in which the maleimide content in the resin component of the maleimide resin exceeds the scope of the present invention.

It is inferior in Izotsu impact strength, falling weight strength, and paintability.

Comparative Example 2: This is an example in which the amount of polyphenylene ether used is less than the range of the present invention, and the heat resistance is poor.

Comparative Example 3: Maleimide resin was out of range (low amount), and heat distortion temperature, weather resistance, and paintability were poor.

Comparative Example 4: Maleimide resin is out of range (a lot),
Poor isot impact strength, falling weight strength, and moldability.

Effects of the Invention The present invention provides a composition comprising a polyphenylene ether and a maleimide copolymer, in which the content of N-substituted maleimide, which is a co-electrical component in the maleimide copolymer, is extremely low compared to conventionally known compositions. By using a small amount of maleimide copolymer, it is possible to obtain a composition that has a high level of physical property balance, with particularly excellent weather resistance, paintability, and practical impact resistance, as well as excellent heat resistance and moldability. It is a highly practical thermoplastic resin.

Claims (1)

[Scope of Claims] (A) 5 to 40% by weight of polyphenylene ether, (B)
N-substituted maleimide, in the presence or absence of rubber;
A maleimide-based product obtained by polymerizing a resin component consisting of an aromatic vinyl compound and, if necessary, other copolymerizable monomers, and in which the content of N-substituted maleimide in the resin component is 1 to 15% by weight. A thermoplastic resin composition comprising 10 to 95% by weight of a copolymer and 0 to 65% by weight of (C) a styrene resin.