JP3307132B2 - Thermoplastic resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin composition comprising a copolymer of ethylene and an .alpha.,. Beta.-unsaturated carboxylic acid ester, a polyphenylene ether and an epoxy group-containing ethylene copolymer as essential components. Specifically, the present invention has improved heat resistance and coating film adhesion without impairing the excellent impact resistance and flexibility of a copolymer of ethylene and an α, β-unsaturated carboxylic acid ester. The present invention relates to a thermoplastic resin composition.

[0002]

2. Description of the Related Art A copolymer of ethylene and an α, β-unsaturated carboxylic acid ester has excellent impact resistance, flexibility,
Utilizing high temperature processability, low odor, weather resistance, flexibility, etc.
It is used for extrusion lamination, wire coating, various sheets and films, and the like.

[0003]

However, an injection molded article of a copolymer of ethylene and an α, β-unsaturated carboxylic acid ester, such as an automobile exterior material such as a side molding or a mudguard, has impact resistance and flexibility. An injection-molded article which is required to have good heat resistance, heat resistance, and adhesion to a coating film during coating has a problem that the heat resistance and the adhesion to the coating film are insufficient.
However, in order to improve the heat resistance of a copolymer of ethylene and an α, β-unsaturated carboxylic acid ester, when a polyolefin such as polypropylene is blended with the copolymer, the heat resistance of the resulting blend is improved. Is improved, but the coating adhesion is worse than that of the copolymer. An object of the present invention is to improve the heat resistance and coating adhesion of a copolymer of ethylene and an α, β-unsaturated carboxylic acid ester without impairing the excellent impact resistance and flexibility of the copolymer. The object is to provide a thermoplastic resin composition.

[0004]

Means for Solving the Problems The present inventors have studied the heat resistance of a copolymer of ethylene and an α, β-unsaturated carboxylic acid ester without deteriorating its excellent impact resistance and flexibility. In addition, intensive studies have been made to develop a thermoplastic resin composition having improved coating film adhesion. As a result, a thermoplastic resin composition obtained by blending a copolymer of ethylene and an α, β-unsaturated car- unsaturated carboxylic acid ester with a polyphenylene ether and an epoxy group-containing ethylene copolymer was obtained. Without impairing the excellent impact resistance and flexibility of the copolymer with the unsaturated carboxylic acid ester, it was found that the heat resistance and coating film adhesion were improved, and the present invention was completed. . That is, the present invention relates to a copolymer of ethylene and an α, β-unsaturated carboxylic acid ester (hereinafter also referred to as “component (A)”).
100 parts by weight of a component containing 1 to 60% by weight of a polyphenylene ether (hereinafter also referred to as "component (B)") and an ethylene copolymer having an epoxy group (hereinafter, referred to as "component (B)")
It is a thermoplastic resin composition containing 1 to 50 parts by weight of “component (C)”.

[0005] α according to the component (A) used in the present invention,
As β-unsaturated carboxylic acid esters, ethyl acrylate, methyl acrylate, 2-ethyl acrylate,
Examples include acrylates such as stearyl acrylate, methacrylates such as methyl methacrylate, ethyl methacrylate, 2-ethylhexyl methacrylate, and stearyl methacrylate.

Preferred examples of the component (A) used in the present invention include a copolymer of ethylene and ethyl acrylate, a copolymer of ethylene and methyl acrylate, and a copolymer of ethylene and methyl methacrylate.

The component (A) can be produced from ethylene and an α, β-unsaturated carboxylic acid ester by a known polymerization method, or a known copolymer as the component (A) can be used.

[0008] α, β in component (A) used in the present invention
The content of the repeating unit derived from the unsaturated carboxylic acid ester is 3 to 60% by weight, preferably 5 to 40% by weight; When the content of the repeating unit is less than 3% by weight, the adhesion of the coating of the composition of the present invention is insufficient, and when the content is more than 60% by weight, the composition of the present invention Insufficient heat resistance.

The melt index of the component (A) used in the present invention is 0.2 to 400 g / 10 min (measurement method is AS
TM I-1238, 190 ° C).

The component (B) used in the present invention is a known polymer. One or more of the phenol compounds represented by the general formula (1) can be converted to oxygen or an oxygen-containing gas using an oxidation coupling catalyst. It is a polymer obtained by oxidative polymerization.

[0011]

Embedded image (Wherein R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are selected from hydrogen, a halogen atom, a hydrocarbon group or a substituted hydrocarbon group, and one of them is always a hydrogen atom)

In general formula 1, R ₁ , R ₂ , R ₃ , R
₄ and specific examples of R ₅ are hydrogen, chlorine, bromine, fluorine, iodine, methyl, ethyl, n- or iso- propyl, pri, sec-or t- butyl, chloroethyl, hydroxyethyl, phenylethyl, benzyl , Hydroxymethyl, carboxyethyl, methoxycarbonylethyl, cyanoethyl, phenyl, chlorophenyl, methylphenyl, dimethylphenyl, ethylphenyl and allyl.

Specific examples of the general formula 1 include phenol, o-, m-, or p-cresol, 2,6-,
2,5-, 2,4- or 3,5-dimethylphenol, 2-methyl-6-phenylphenol, 2,6-diphenylphenol, 2,6-diethylphenol,
-Methyl-6-ethylphenol, 2,3,5-, 2
3,6- or 2,4,6-trimethylphenol, 3
-Methyl-6-t-butylphenol, thymol, 2-
Methyl-6-allylphenol is exemplified.

Further, a phenolic compound other than the general formula 1 such as bisphenol-A, tetrabromobisphenol-A, resorcinol, hydroquinone, and a polyhydric hydroxyaromatic compound such as a novolak resin is used.
Can also be used as the component (B).

The preferred component (B) used in the present invention is a homopolymer of 2,6-dimethylphenol or 2,6-diphenylphenol, a large part of 2,6-xylenol and a small part of 3-methyl-phenol. Copolymers with 6-t-butylphenol or 2,3,6-trimethylphenol are exemplified. The intrinsic viscosity η ₀ of the component (B) is 0.45 or less, preferably 0.4 or less.

The oxidative coupling catalyst used in the oxidative polymerization of the phenol compound is not particularly limited, and any catalyst having a polymerization ability can be used.

The mixing ratio of the component (A) and the component (B) used in the production of the composition of the present invention is 40 to 40%.
99% by weight and 1 to 60% by weight of the component (B), where the combined amount of both components is 100% by weight.

The component (C) used in the present invention is an epoxy group-containing ethylene copolymer having an epoxy group in a main chain or a side chain. The copolymer is obtained by copolymerizing ethylene and a monomer having an epoxy group, or by oxidizing a carbon-carbon double bond in a copolymer of ethylene and a diene compound such as butadiene with ozone or the like. can get. Component (C) is preferably a unit derived from ethylene (hereinafter also referred to as “unit (a)”) and a unit derived from unsaturated glycidyl carboxylate copolymerizable with ethylene (hereinafter referred to as “unit”). (B-1)) or a unit derived from a glycidyl ether having an unsaturated group copolymerizable with ethylene (hereinafter referred to as “unit (b)
-2) ") as an essential repeating unit.

The unsaturated carboxylic acid glycidyl ester for deriving the unit (b-1) is a compound represented by the general formula (2).

[0020]

Embedded image (Wherein, R is a group having 2 to 2 carbon atoms having an ethylenically unsaturated bond)
18 alkenyl groups)

Examples of the compound represented by the general formula 2 include glycidyl acrylate, glycidyl methacrylate and glycidyl itaconate.

The glycidyl ether having an unsaturated group for deriving the unit (b-2) is a compound represented by the general formula (3).

[0023]

Embedded image (Wherein, R is a group having 2 to 2 carbon atoms having an ethylenically unsaturated bond)
18 is an alkenyl group, and X is CH ₂ —O or O)

Examples of the compound represented by the general formula 3 include allyl glycidyl ether, 2-methylallyl glycidyl ether and styrene-p-glycidyl ether.

The component (C) comprises a unit (a) and a unit (b-
In addition to 1) or (b-2), a unit derived from an ethylenically unsaturated compound (hereinafter, also referred to as “unit (c)”)
Can be included as an arbitrary repeating unit.

Examples of the ethylenically unsaturated compound from which the unit (c) is derived include α, β-unsaturated carboxylic acid alkyl esters such as methyl acrylate, ethyl acrylate, butyl acrylate and methyl methacrylate, vinyl acetate, vinyl propionate and butanoic acid. Examples thereof include carboxylic acid vinyl esters such as vinyl, vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether and phenyl vinyl ether, and styrenes such as styrene, methyl styrene and ethyl styrene.

The proportion of each unit constituting the component (C) is 50 to 99% by weight of the unit (a) and 0.1 to 100% by weight of the unit (b).
It is 50% by weight, preferably 0.5 to 20% by weight, and the unit (c) is 0 to 50% by weight, preferably 10 to 40% by weight.

Specific examples of the component (C) include ethylene-glycidyl methacrylate copolymer, ethylene-glycidyl methacrylate-methyl acrylate copolymer, ethylene-glycidyl methacrylate-ethyl acrylate copolymer, ethylene-glycidyl methacrylate-vinyl acetate. And copolymers. Among them, an ethylene-glycidyl methacrylate copolymer, an ethylene-glycidyl methacrylate-methyl acrylate copolymer, and an ethylene-glycidyl methacrylate-ethyl acrylate copolymer are preferable.

The glycidyl group content of component (C) is 0.1
% Or more, and the melt index of the component (C) is 0.5 to 3000 g / 10 min (J
ISK6760).

The component (C) can be produced by various known polymerization methods. For example, a method of copolymerizing ethylene with a compound represented by general formula 2, a method of copolymerizing ethylene with a compound represented by general formula 3, a method of copolymerizing ethylene with a compound represented by general formula 2, A method of copolymerizing the compound represented by formula (3) with a homopolymer of ethylene or a copolymer of ethylene with an olefin such as propylene copolymerizable with ethylene (hereinafter, also referred to as “ethylene copolymer”). A method of graft-polymerizing a compound represented by Formula 2 or 3, graft-polymerizing a compound represented by General Formula 2 or 3 onto a copolymer of ethylene and an ethylenically unsaturated compound that induces a unit (c). The method of making it perform can be illustrated.

As an example of a specific method for producing the component (C), ethylene and the compound represented by the general formula (2) or (3) may be used in the presence of a radical generator at a pressure of 500 to 4000 atm. At a temperature of ° C., in the presence or absence of a suitable solvent or chain transfer agent,
An ethylene homopolymer or an ethylene copolymer, which is a copolymer of ethylene and propylene, has a general formula 2 or 3
And a method in which a compound represented by the formula (1) and a radical generator are mixed, and the mixture is melt-kneaded in a Banbury kneader or an extruder to carry out graft copolymerization.

The composition of the present invention is a polymer of a monomer selected from the group consisting of olefins, diolefins and vinyl aromatic compounds in addition to the components (A), (B) and (C). A polymer having no ester or epoxy functional group (hereinafter, also referred to as “component (D)”) may be included.

Examples of the polymer as component (D) include ethylene, propylene, butene-1, pentene-1,4-methylpentene-1, isobutylene, 1,4-hexadiene, dicyclopentadiene, 2,5-norbornadiene, 5-ethylidene norbornene, 5-ethyl-2,5
-Norbornadiene, 5- (1'-propenyl) -2-
A polymer of at least one monomer selected from norbornene can be exemplified. Preferred examples of the component (D) include, besides polyethylene and polypropylene, a block or random copolymer of α-olefin such as ethylene, propylene and butene.

The mixing ratio of the component (D) is 1 to 200 parts by weight based on 100 parts by weight of the total of the components (A) and (B). If the mixing ratio of the component (D) exceeds 200 parts by weight, the resulting composition will have insufficient impact resistance and coating film adhesion.

The composition of the present invention may contain various fillers in order to improve rigidity and hardness as required. Examples of fillers include calcium carbonate, magnesium carbonate, aluminum hydroxide, magnesium hydroxide, zinc oxide, titanium oxide, magnesium oxide, aluminum silicate, magnesium silicate, calcium silicate, silicic acid, hydrous calcium silicate, and hydrous silica. Aluminum acid,
Mica, mineral fiber, zonotrite, potassium titanate
Whisker, magnesium oxysulfate, glass balun, glass fiber, glass beads, carbon fiber, inorganic fiber such as stainless steel fiber, aramid fiber, carbon black, and the like, and the composition of the present invention can contain one or more of these fillers. .

The compositions of the present invention can also include various additives such as flame retardants, plasticizers, antioxidants, weathering agents. In particular, when additives known as additives for component (A), component (B) or component (D) are used, the physical properties of the resulting composition may be further improved.

The thermoplastic resin composition of the present invention can be produced by melt-kneading components to be used by a known method. The order of blending and melt-kneading of the components at the time of melt-kneading is arbitrary.For example, a method of melt-kneading the blend after blending all the components at once, some components of all the components and the After separately compounding and melt-kneading the remaining components, a method of further melt-kneading the obtained plurality of kneaded materials at once, having a plurality of feed ports from the upstream side to the downstream side of the extruder. In one extruder, a method of sequentially feeding each component from each feed port and melt-kneading in the extruder may be exemplified. As a preferred melt-kneading method, the components (B), (C) and (D) are fed from the upstream feed port of an extruder having two feed ports, and the component (A) is fed from the downstream feed port. May be exemplified.

The thermoplastic resin composition of the present invention can be easily molded by molding methods generally applied to thermoplastic resins and resin compositions, such as injection molding, extrusion molding, and hollow molding. Can be. Since the composition of the present invention has good impact resistance, flexibility, heat resistance, coating film adhesion and the like, it is suitably used as an injection molded product such as a side molding, a mudguard, a bumper, a window frame and other automobile parts. obtain.

The composition of the present invention has a morphology in which the component (A) is a continuous phase and the component (B) is a dispersed phase. In order to achieve the object of the present invention, the dispersed phase particles comprising the component (B) are required. Preferably has a diameter of 5 μm or less.

[0040]

In the present invention, component (B) is used for improving heat resistance and coating film adhesion, and component (D) is used for improving heat resistance and impact resistance. How component (C) acts in the composition,
The mechanism of action itself is not clear. However, the component (B) in the composition obtained when the components (A) and (B) inherently having low compatibility are melt-kneaded in the absence of the component (C).
Has a large dispersed particle size of 10 μm or more, and the mechanical properties of the composition are extremely low, but surprisingly, when both components are melt-kneaded in the presence of component (C). The dispersed particle size of (B) in the composition obtained in (1) is smaller than that, and the mechanical properties of the composition are extremely good. Therefore, it is estimated that the dispersibility of (B) in the obtained composition is improved as a result of improving the compatibility between the component (A) and the component (B) by the component (C).

[0041]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples. The components used are as follows.

Component (A) Polymer-A: a copolymer of ethylene and methyl methacrylate having a methyl methacrylate content of 5
Wt%, melt index 2 (190 ° C, 216
kg load). Polymer-B: a copolymer of ethylene and methyl methacrylate having a methyl methacrylate content of 2
0% by weight and a melt index of 20 (190 ° C., 2.
16kg load). Polymer-C: a copolymer of ethylene and methyl methacrylate having a methyl methacrylate content of 2
0 wt%, melt index 70 (190 ° C, 2.
16kg load). Polymer-D: a copolymer of ethylene and ethyl acrylate, having an ethyl acrylate content of 20% by weight and a melt index of 20 (190 ° C., 2.16
kg load).

Component (B) A chloroform solution (concentration: 0.5 g / d ) obtained by homopolymerizing 2,6-dimethylphenol
1) Polyphenylene ether having a logarithmic viscosity at 30 ° C. of 0.30. Hereinafter, the polyphenylene ether is referred to as “PP
E ".

Component (C) EPO-1: a copolymer of ethylene and glycidyl methacrylate having a glycidyl methacrylate content of 6
Wt%, melt index 3 (190 ° C., 2.16
kg load). EPO-2: a copolymer of ethylene, glycidyl methacrylate and methyl acrylate, having a glycidyl methacrylate content of 3% by weight, a methyl acrylate content of 30% by weight, and a melt index of 9 (190 ° C.,
2.16 kg load). EPO-3: a copolymer of ethylene, glycidyl methacrylate and methyl acrylate, having a glycidyl methacrylate content of 6% by weight, a methyl acrylate content of 30% by weight, and a melt index of 20 (190 ° C.,
2.16 kg load).

Component (D) BPP: 30 wt% ethylene-propylene part, block polypropylene, having a melt index of 8 d
g / min (230 ° C, 2.16 kg load). EPR: Ethylene-propylene rubber obtained by polymerization of ethylene and propylene, having an ethylene content of 22% by weight and a melt index of 0.9 dg / min (19
0 ° C, 2.16 kg load).

Examples 1 to 7 The mixing ratio (parts by weight) of each component is as shown in Tables 1 and 2. The component (B) and the component (C), or the component (B), the component (C) and the component (D) are mixed with each other by a first twin-screw kneading extruder (TEM50 manufactured by Toshiba Machine Co., Ltd.) on the upstream side. After being charged from the feed port and melt-kneaded at a cylinder temperature of 260 ° C., the component (A) is charged from the downstream second feed port provided between the first feed port and the die, and fed from the upstream side. The obtained melt-kneaded product and the component (A) were melt-kneaded. The cylinder temperature downstream of the second feeder port is 20
It was set to 0 ° C. The molten resin extruded from the die was cooled in a water bath and then pelletized by a strand cutter.

Comparative Examples 1 to 3 Comparative Example 1 was the same as Example 1 except that the component (C) was not used.
This is an example performed in the same manner. Comparative Examples 2 and 3 show that component (B)
This is an example performed in the same manner as in Example 2 except that no component (C) was used.

The preparation method and test method of the test piece are as follows. That is, after vacuum drying the obtained pellets at a temperature of 60 ° C. for 3 hours, an injection molding machine (TOSHIBA MACHINE IS
220EN), a flat plate having a thickness of 3.0 mm was formed from the pellets under the conditions of a cylinder temperature of 200 ° C, an injection pressure of 1200 kg / cm ² , and a mold temperature of 30 ° C.

Melt index (hereinafter also referred to as “MI”; unit is dg / min) After the above pellets were vacuum-dried at a temperature of 60 ° C. for 3 hours,
It was determined by measuring at 230 ° C. under a load of 2.16 kg.

Izod impact strength (unit: kgfcm /
cm) The above-mentioned flat plate having a thickness of 3.0 mm was cut to prepare a test piece (with a notch) for an Izod impact test, and was subjected to ASTM D256.
The test was carried out in a -30 ° C atmosphere according to.

Flexural modulus (unit: kgf / cm ² ) The above-mentioned flat plate having a thickness of 3.0 mm was cut to prepare a test piece for a bending test, which was tested in an atmosphere at 23 ° C.

Heat sag (unit: mm) 125 mm formed by cutting a flat plate having a thickness of 3.0 mm.
A test piece of 25 mm x 25 mm x 3.0 mm (thickness) was fixed at one end with an overhang of 100 mm, allowed to stand at 90 ° C for 1 hour, then left at 23 ° C for 1 hour, Was measured for the amount of deformation due to the thermal history of the sample (the amount of the sample was lowered compared to before the test).

Adhesiveness of coating film 150 was prepared by cutting a flat plate having a thickness of 3.0 mm.
A test piece having a size of 150 mm x 3 mm (thickness) was coated with a paint called RECOLAC # 2300 (manufactured by Fujikura Kasei Co., Ltd.) under a normal condition to a thickness of about 25 to 30 µm with a coating gun. Dry in oven at 80 ° C. for 30 minutes. The test pieces after 24 hours and 48 hours from drying were subjected to a cellophane tape peeling test. Here, the cellophane peel test is as follows. That is, first, a parallel linear notch having a width of about 2 mm is formed using a knife in the vertical and horizontal directions on the coating surface of the test piece.
10 squares with a size of about 2 mm x about 2 mm on the coating surface
Create 0 items. Thereafter, a cellophane tape is stuck on the grid. Thereafter, the cellophane tape was peeled off, and the remaining rate of the coating film that was not peeled off (residual rate per 100 squares)
Is measured. The higher the residual ratio, the greater the coating film adhesion.

Dispersion particle size of polyphenylene ether (unit: μm) After cooling the above flat plate having a thickness of 3.0 mm with liquid nitrogen,
An ultrathin section was prepared from the plate at 80 ° C. using a microtome, stained with ruthenium oxide (RuO ₄ ), and observed with a transmission electron microscope to determine the number average dispersed particle size of polyphenylene ether.

Tables 1 to 5 for Examples 1 to 5 show Examples 6 to
Table 2 summarizes Table 7 and Comparative Examples 1 to 3.

[0056]

According to the present invention, by dispersing and stabilizing polyphenylene ether using a copolymer of ethylene and an α, β-unsaturated carboxylic acid ester with an epoxy group-containing ethylene copolymer, ethylene and α, β, A resin composition having improved heat resistance and coating film adhesion without impairing the excellent impact resistance and flexibility of a copolymer with a β-unsaturated carboxylic acid ester can be obtained.

[0057]

[Table 1] ──────────────────────────────────── Example 1 Example 2 Example 3 Example Example 4 Example 5 Component (A) Polymer-A 70---50 Polymer-B--30--Polymer-C-30----Polymer-D---30-Component (B) PPE 15 15 15 15 15Component (C) EPO-2-10 10 10 15 EPO-3 15-----Component (D) BPP-35 35 35 20 EPR-10 10 10 10 10 MI 3 15 11 11 4 Izod impact strength 4.7 6.2 6.2 6.5 6.6 9.1 Flexural modulus 2300 3500 3600 3400 1900 Heat sag 3.2 4.2 2.1 2.2 4.9 Coating adhesion After 24 hours 75 95 75 81 85 After 48 hours 99 100 99 99 99 PPE dispersed particle size 2.3---- ────────────────

[0058]

２ Example 6 Example 7 Comparative Example 1 Comparison Example 2 Comparative Example 3 Component (A) Polymer-A--82.4--Polymer-C 30 30-45 33Component (B) PPE 1520 17.6-17Component (C) EPO-1 10----EPO-2---10-EPO-3-10---Component (D) BPP 35 30-35 39 EPR 10 10 -10 11 ＭＩMI 12 12 6 35 22 Izod impact strength 5.5 6.3 1.3 13 1.7 Flexural modulus 4100 3500 4100 2600 3900 Heat sag 1.8 3.8 3.0> 508Coating adhesion After passage of 24 hours 65 98 11 82 72 After passage of 48 hours 98 100 29 93 86 Dispersion particle size of PPE-1.9 12-- ────────────────

Claims (4)

(57) [Claims] 100 parts by weight of component (A) containing 40 to 99% by weight of a copolymer of ethylene and an α, β-unsaturated carboxylic acid ester and component (B) of 1 to 60% by weight of polyphenylene ether and component (C) A thermoplastic resin composition containing 1 to 50 parts by weight of an epoxy group-containing ethylene copolymer. 2. An epoxy group-containing ethylene copolymer of the component (C) is composed of (a) units derived from ethylene of 50 to 99 units.
% By weight, (b-1) a unit derived from an unsaturated carboxylic acid glycidyl ester copolymerizable with ethylene or (b)
-2) an epoxy containing 0.1 to 50% by weight of units derived from a glycidyl ether having an unsaturated group copolymerizable with ethylene and (c) 0 to 50% by weight of units derived from an ethylenically unsaturated compound The thermoplastic resin composition according to claim 1, which is a group-containing ethylene copolymer. 3. The total amount of the components (A), (B) and (C) is 1.
Further, component (D) olefin and geo
A polymer of a monomer selected from the group consisting of refins , which has no ester or epoxy functional group;
2. The thermoplastic resin composition according to claim 1, comprising 200 parts by weight. 4. The thermoplastic resin composition according to claim 1, wherein the dispersed particle diameter of the polyphenylene ether of the component (B) is 5 μm or less.