JPS62243633A - Polyolefin resin composition - Google Patents

Abstract

PURPOSE:To provide a resin composition outstanding in mechanical strength, heat resistance, rigidity and dimensional stability, enhanced in impact strength, especially falling weight impact strength, comprising polyolefin, styrene-maleic anhydride copolymer and glass fiber. CONSTITUTION:The objective resin composition can be obtained by blending (A) 40-90(pref. 50-80)wt% of a polyolefin (pref. propylene homopolymer, propylene-ethylene copolymer or polybutene-1), (B) 5-30(pref. 10-20)wt% of a styrene-maleic anhydride copolymer containing pref. 70-98mol% of styrene unit, and (C) 5-50(pref. 10-40)wt% of glass fiber (pref. E-glass fiber), and pref. furthermore, (D) <=10pts. by wt. per 100pts. by wt. of the components A, B plus C, of a modified polyolefin (pref. modified with unsaturated carboxylic acid (derivative) or epoxy compound).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a polyolefin resin composition blended with glass fiber. More specifically, the present invention not only has excellent mechanical strength, heat resistance, and rigidity, but also improves dimensional stability by suppressing warping during molding, and improves impact strength, especially falling weight impact strength. The present invention relates to a reinforced glass fiber reinforced polyolefin resin composition.

[Conventional technology]

Polyolefins have excellent tensile strength, rigidity, heat resistance, chemical resistance, etc., and are easy to mold, so they are used as general-purpose resins in many fields. In such applications, even higher mechanical strength, rigidity, heat resistance, etc. are required, so polyolefin resins reinforced by various methods have been developed.

Glass fiber reinforced polyolefin resin is known as a typical reinforced polyolefin resin. Although this glass fiber-reinforced polyolefin resin generally has excellent mechanical strength and heat resistance, it suffers from warping during molding and has poor dimensional stability.

Therefore, many methods have been taken to overcome these drawbacks. For example, compositions have been proposed in which a relatively small anisotropic inorganic filler such as talc or mica is blended with polyolefin together with glass fiber (Japanese Patent Publication No. 49-20930, Japanese Unexamined Patent Publication No. 59-18
Publication No. 4247, Japanese Unexamined Patent Publication No. 59-226041 f0
However, although these compositions have relatively improved dimensional stability, they have the disadvantage of inevitably decreasing impact resistance, and compositions containing glass fibers and amorphous rubber reinforcement has also been proposed (Japanese Patent Publication No. 59-2294), but this has the drawback of insufficient heat-resistant rigidity.

Furthermore, there are compositions in which a copolymer containing ethylene units, acrylic acid or methacrylic acid units, and vinyl alcohol units is blended with polyolefin together with glass fiber (Japanese Patent Publication No. 35419/1983), and polyolefin in the presence of polystyrene. A composition (Japanese Unexamined Patent Publication No. 50-58153) has been proposed in which a modified glass fiber is added to the modified composition. However, in the former composition,
Although the adhesion between polyolefin and glass fiber has been improved, and mechanical strength and heat resistance have been relatively improved, dimensional stability is not always satisfactory, and in the latter composition, It has a disadvantage that it has poor compatibility with polyolefins and inevitably suffers a decrease in impact strength, especially falling weight impact strength.

[Problem that the invention seeks to solve]

In view of these circumstances, the present invention not only has excellent mechanical strength, heat resistance, and rigidity, but also improves dimensional stability by suppressing warpage during molding, and improves impact strength, especially falling weight impact. The object of the present invention is to provide a glass fiber reinforced polyolefin resin composition with increased strength.

[Means for solving problems]

As a result of intensive research to achieve the above object, the present inventors found that the adhesion between styrene-maleic anhydride copolymer and glass fiber was good. , focused on the fact that polyolefins mix well, and discovered that this goal could be achieved by blending this styrene-maleic anhydride copolymer with glass fibers into polyolefins in a predetermined ratio, and based on this knowledge, As a result, the present invention was completed.

That is, in the present invention, (A) polyolefin 40 to 90
Weight %, (B) styrene-maleic anhydride copolymer 5~
30% by weight and (C') a polyolefin resin composition containing 5 to 50% by weight of glass fiber, and 100 parts by weight of (D) modified polyolefin 1
The object of the present invention is to provide a polyolefin resin composition containing 0 parts by weight or less.

Examples of the polyolefin used as component (A) in the composition of the present invention include polypropylene, propylene-
Ethylene copolymer, polyethylene, or ethylene-
propylene copolymer, ethylene-butene-1 copolymer,
Ethylene-α olefin copolymers such as ethylene-octene-1 copolymer and ethylene-hexene-1 copolymer,
Examples include polybutene-11 poly-4-methylpentene-1, among which propylene homopolymer,
Propylene-ethylene copolymers and polybutene-1 are preferred.

These polyolefins may be used alone or in combination of two or more (and their content is 40 to 90% by weight, preferably 5% by weight, based on the composition).
It is selected in the range of 0 to 80% by weight. In a composition in which the content of polyolefin is outside the above range, the object of the present invention cannot be achieved.

The styrene-maleic anhydride copolymer used as component (B) in the composition of the present invention can be prepared by polymerizing the styrene component and the maleic anhydride component using known methods such as solution polymerization, bulk polymerization, and bulk-suspension polymerization. It is obtained by polymerization according to the method. Examples of the styrene component include styrene, α-methylstyrene, dichlorostyrene, dimethylstyrene, etc. Each of these may be used alone or in combination of two or more. It may be partially substituted with, for example, methacrylic acid, methyl methacrylate, methyl acrylate, ethyl methacrylate, acrylonitrile, methacrylonitrile, halogen-containing polymers, etc., within a range that does not impair the purpose. On the other hand, the maleic anhydride component includes maleic anhydride, which may be partially substituted with itaconic anhydride, ethylmaleic anhydride, chloromaleic anhydride, etc., to the extent that the object of the present invention is not impaired. It's okay.

Further, the copolymer may be a copolymer of the styrene component and maleic anhydride component in the presence of a rubber component such as butadiene rubber, ethylene propylene rubber, MBS, etc. Regarding the proportion of styrene units and maleic anhydride units in the polymer, preferably 70 to 98 mol% of styrene units, 30 to 2 mol% of maleic anhydride units, more preferably 80 to 96 mol% of styrene units, maleic anhydride units. Acid units 20-4 mol%
It is desirable that it be within the range of .

The amount of the styrene-maleic anhydride copolymer in the composition of the present invention is 5 to 30% by weight, preferably 10 to 2% by weight.
It is selected in the range of 0% by weight. If this amount is less than 5% by weight, the effect of improving warpage during molding will not be sufficient, while if it exceeds 30% by weight, heat resistance and fluidity will inevitably deteriorate.

In the composition of the present invention, examples of the glass fiber used as component (C) include E glass fiber, A glass fiber, C
Any type of glass fiber may be used or a combination of these may be used, but E glass fiber is preferred.

The length of glass fibers in the composition is preferably 0.
．． It is desirable that the length of the glass fibers be within the range of 1 to 2 cm, particularly preferably 0.3 to 11 cm, and since there is a risk that the glass fibers may be broken during kneading, the length of the glass fibers when feeding is The diameter is preferably in the range of 2 to 6 M, and the diameter is usually selected in the range of 1 to 20 μm, preferably 3 to 15 μm. The form of the glass fiber is not particularly limited, and any form such as roving, milled fiber, chopped strand, etc. may be used.

The glass fibers may be used as they are, but in order to increase their adhesion to both the polyolefin and the styrene-maleic anhydride copolymer and improve their physical properties, various coupling agents such as silane, titanate, and aluminum may be used. It is also possible to use a material whose surface has been treated with a coupling agent such as chromium-based, chromium-based, or boron-based. Among these coupling agents, silane coupling agents such as vinyl silanes such as vinyltris(2-methoxyethoxy)silane, aminosilanes such as T-aminopropyltriethoxysilane, and γ-glycidoxypropyltoxysilane are used. Preferred are epoxysilanes such as methoxysilane, acrylicsilanes such as T-methacryloxypropyltrimethoxysilane, and particularly preferred are aminosilanes.

The blending amount of the glass fiber in the composition of the present invention is 5 to 50
% by weight, preferably in the range of 10 to 40% by weight. When this amount is less than 5% by weight, the effect of improving bending strength, rigidity, and heat resistance is not sufficiently exhibited.

On the other hand, if it exceeds 50% by weight, the moldability will be significantly reduced and the appearance will be poor, and furthermore, it will be difficult to prepare the composition.

In order to further improve the physical properties such as impact strength, rigidity, and heat resistance of the polyolefin resin composition, component (A), (B
Also included in the present invention is a composition in which less than 100 parts by weight of modified polyolefin IO is blended as component (D) with respect to a mixture containing components () and (C) in the above proportions.

As the modified polyolefin, for example, one modified with an unsaturated carboxylic acid or a derivative thereof, or one modified with an epoxy compound is preferably used. Preferably, the polyolefin used in the modified polyolefin is a polypropylene resin such as a propylene homopolymer, a block copolymer of propylene and another copolymer component such as ethylene, or a random copolymer. Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, citraconic acid, sorbic acid, mesaconic acid, and angelic acid. There are acid anhydrides, esters, amides, imides, metal salts, etc., such as maleic anhydride, itaconic anhydride, citraconic anhydride, methyl acrylate, methyl methacrylate,
Examples include ethyl acrylate, butyl acrylate, maleic acid monoethyl ester, acrylamide, maleic acid monoamide, maleimide, N-butylmaleimide, sodium acrylate, and sodium methacrylate. Among these, acrylic acid, maleic anhydride and the like are preferred.

There are no particular limitations on the method for modifying polyolefins with these unsaturated carboxylic acids or derivatives thereof, and various known methods can be used. For example, by adding a radical initiator to polyolefin and maleic anhydride in the presence or absence of a solvent,
This is done by heating. During the reaction, other vinyl monomers such as styrene or rubbers such as liquid rubber and thermoplastic rubber may also be present. The modified polyolefin used in the present invention has an acid addition amount of 0.5 to 1.
0% by weight is preferred.

In addition, polyolefins modified with epoxy compounds are
For example, it can be obtained by modifying the polyolefin in a similar manner using an epoxy compound such as glycidyl acrylate or glycidyl methacrylate.

A mixture 100 containing the above-mentioned components (A), (B) and (C) in which the blended amounts of these modified polyolefins are
If the amount exceeds 10 parts by weight, the physical properties will not improve in proportion to the amount, but rather the impact strength will decrease and the cost will increase, which is economically disadvantageous.

In the present invention, a composition containing components (A), (B), and (C) or a composition containing components (A), (B), (C), and (D), Furthermore, in order to suppress warping and improve impact strength, rigidity, and heat resistance, the organic peroxide is preferably 0.01 to 0.11 parts by weight, more preferably 0.01 to 0.11 parts by weight, per 100 parts by weight of the composition. may be added as desired in the range of 0.03 to 0.05 parts by weight and melt-kneaded. If this amount is less than 0.01 parts by weight, the addition effect will not be sufficiently exhibited, and 0.1 parts by weight. If it exceeds this amount, the polymer will be severely cut and the impact strength will inevitably decrease.

Examples of the organic peroxide include benzoyl peroxide, lauroyl peroxide, dicumyl peroxide, di-t-butyl peroxide, 1,3-bis(t-butylperoxyisopropyl)benzene, t-
Butyl peracetate, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane-3,2,5-dimethyl-2,5-(t-butylperoxy)hexane,
t-butyl perbenzony 1-1 t-butyl perphenyl acetate, t-butyl perisobutylene-1, t-
Examples include butyl per-5ec-oftate, t-butyl perpipalate, cumyl perbivalate, [-butyl per diethyl acetate, dichlorobenzoyl peroxide and the like. Among these, benzoyl peroxide, lauroyl peroxide, dicumyl peroxide, 1,3-bis(t-butylperoxyisopropyl)benzene and the like are preferred.

The composition of the present invention may optionally contain non-fibrous inorganic fillers such as talc, mica, and calcium carbonate, and elastomers such as polybutadiene, EPR, EPDM, and MBS within the range that does not impair the purpose of the present invention. You can also
Furthermore, various additives commonly used in polyolefin resin compositions, such as antistatic agents, ultraviolet absorbers, antioxidants, and colorants, can also be added.

The composition of the present invention includes, for example, components (A), (B), and (C) or the respective required amounts of components (A), (B), (C), and (D), and optionally added organic peroxides. Adjust the amount of other additives required using a tumbler-1V blender,
It may be prepared by mixing with a ribbon blender etc., then melting and kneading with a -shaft kneader etc. to form pellets.Also, each essential component except the glass fiber of component (C) may be prepared according to the required amount. After mixing the required amount of organic peroxide and other additives to be added as desired using a tumbler-1V type blender, ribbon blender, etc.,
For example, this is put into the hopper of a cantilever twin-screw kneader, and the glass fibers are put into the hopper in the middle of the cylinder, melted, kneaded, and pelletized while minimizing cutting. Good too. In addition, it is preferable to use a quantitative feeder for the above-mentioned feeding.

〔Example〕

EXAMPLES Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to these examples in any way.

In addition, each physical property was evaluated according to the following method.

(1) Isotsu impact strength (notched) JIS
Measured according to K 7110.

(2) Falling weight impact strength Measured under the following conditions: 1 kg load, 1/2 inch percussion system, and saucer 501φ.

(3) Bending strength Measured in accordance with JIS K 7203.

(4) Flexural modulus: Measured according to JIS K 7203. (5) Heat distortion temperature: Measured according to JIS K 7207.

(6) Warpage rate A disk with a diameter of 150n+ and a thickness of 3fl is formed, and this disk is placed on a flat plate, and the height from the plate surface to the part along the disk, that is -D1 and D2 was measured, and the warpage rate was calculated using the following formula.

D, +D.

Examples 1 to 12, Comparative Examples 1 to 6 A predetermined amount of each component as shown in the attached table was placed in a tumbler.
After tri-blending, the mixture was melt-kneaded at 240°C using a 50φ pent-shaft kneader and pelletized to prepare a polyolefin resin composition.
A test piece and a disk for measuring the warpage rate were prepared using an injection molding machine, and each physical property was determined. The results are shown in the table.

Example 13 Glass fiber was removed (each component was tri-blended in a tumbler, then a twin-screw kneader (manufactured by Uniluna, ZSK-57) was used.
The glass fibers were side-fed using a
A polyolefin resin composition was prepared by melt-kneading at 0° C. and pelletizing. Then, using this, a test piece and a disk for measuring the warp rate were prepared using an injection molding machine, and each physical property was determined. The results are shown in the cough table.

Below margins A: Ml 3g/10min propylene-ethylene copolymer (Idemitsu Polypropylene J465H1 manufactured by Idemitsu Petrochemical Co., Ltd.) B: Mr 7g/10min polypropylene (Idemitsu Polypropylene J700G, manufactured by Idemitsu Petrochemical & Engineering Co., Ltd.) a: Styrene-maleic anhydride copolymer KuMoamax UG8 containing maleic anhydride units at FF114% by mole
30, manufactured by Idemitsu Petrochemical Co., Ltd.) b: Styrene-maleic anhydride copolymer containing 1114 mol% of maleic anhydride units and 20% by weight of MBS (Moremax U H
830, manufactured by Idemitsu Petrochemical Co., Ltd.) C: Styrene with a maleic anhydride unit content of 7 mol%
Anhydrous maleic M co-M combination (Moremax UG430, manufactured by Idemitsu Petrochemical Co., Ltd.) *d: Polystyrene (Idemitsu Styrene HH30, manufactured by Idemitsu Petrochemical Co., Ltd.) *e: Rubber reinforced polystyrene (Idemitsu Styrene HT5)
0, manufactured by Idemitsu Petrochemical Co., Ltd.) Modified polyolefin: Maleic anhydride-modified polypropylene with a maleic acid addition amount of 6.5% by weight (Polytac ■ (-1ooop, manufactured by Idemitsu Petrochemical Co., Ltd.) Organic peroxide: 1.3- Bis(t-butylperoxyisopropyl)benzene glass fiber: Glass fiber with fiber system of 13 μm and fiber length of 3-lens, aminosilane coupling index surface treated [Effects of the Invention] The polyolefin resin composition of the present invention can be In addition to having excellent physical strength, heat resistance, and rigidity, it also suppresses warping during molding, improves dimensional stability, and has excellent impact strength, especially falling weight impact strength. Therefore, it is suitable for use in mechanical parts, home appliance parts, automobile parts, structural materials, and applications exposed to high temperatures.For example, home appliance parts include fans and fan shrouds, and automobile parts include air cleaner cases and fans. Useful for shrouds, etc.

[Brief explanation of drawings]

The figure is an explanatory diagram for determining the warpage rate of a molded article obtained from a polyolefin resin composition.

Claims (1)

[Claims] 1. Contains (A) 40 to 90% by weight of polyolefin, (B) 5 to 30% by weight of styrene-maleic anhydride copolymer, and (C) 5 to 50% by weight of glass fiber. Polyolefin resin composition. 2. Mixture 10 containing (A) 40 to 90% by weight of polyolefin, (B) 5 to 30% by weight of styrene-maleic anhydride copolymer, and (C) 5 to 50% by weight of glass fiber
A polyolefin resin composition containing 10 parts by weight or less of modified polyolefin (D) per 0 parts by weight. 3. The polyolefin resin composition according to claim 2, wherein the modified polyolefin is modified with an unsaturated carboxylic acid, a derivative thereof, or an epoxy compound.