JPH0776294B2 - Modified polyolefin resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a modified polyolefin resin composition. More specifically, the present invention is suitable as a molding material in the fields of automobiles and home appliances, or in other industrial fields, and is excellent in balance of impact strength, rigidity, heat distortion temperature, surface hardness, moldability, and the like. The present invention relates to a glass fiber reinforced modified polyolefin resin composition in which warpage is significantly suppressed.

[Conventional technology]

In recent years, polyolefins such as polyethylene, polypropylene and their copolymers have greatly expanded their uses as molding materials with excellent physical properties, mechanical properties, electrical properties, chemical stability, etc. that are easy to mold. Came.
However, this polyolefin is, for example, a mechanical part,
In structural materials, or in applications that are exposed to high temperatures, mechanical strength, dimensional stability, heat resistance, etc. may not be sufficient, so they may not be able to withstand their intended use, and the limitation of use cannot be avoided. There is.

Therefore, many proposals have been made so far regarding a method for reinforcing a polyolefin. Among them, the method of filling a glass fiber with a polyolefin has a large mechanical strength such as tensile strength and rigidity and heat resistance. For this reason, this glass fiber reinforced polyolefin is widely used as a material for industrial parts such as automobile parts and electric parts.

However, this glass fiber reinforced polyolefin
When the molten resin cools and solidifies during molding, warpage occurs due to the difference in shrinkage between the glass fiber and resin, the crystallization of the resin, and the anisotropy of shrinkage due to the orientation of the glass fiber, which causes internal stress. However, there was a problem that it was deformed and the dimensional accuracy was not obtained, and it was unavoidable that its use in precision parts was restricted.

Therefore, various methods have hitherto been attempted in order to suppress the occurrence of warpage of the glass fiber reinforced polyolefin during such molding. For example, a polyolefin composition in which synthetic rubber or natural rubber, glass fiber and powdered talc-based filler are mixed with polyolefin (JP-A-51-136736), modified crystalline polyolefin, glass fiber and amorphous rubber-like elasticity A polyolefin composition containing a polymer (Japanese Patent Publication No. 59-2294), a crystalline polypropylene, a sizing agent-attached glass fiber, a modified polypropylene, an amorphous ethylene-α-olefin copolymer and an inorganic filler. A propylene polymer composition containing a filler (JP-A-59-226041) has been proposed.

However, in these compositions, although warpage at the time of molding is considerably suppressed, the mixing ratio is unsuitable, and necessary constituent components are insufficient, so that mechanical strength such as impact strength and rigidity is reduced. Is insufficient, the fluidity is lowered, the appearance is deteriorated, or the surface hardness is lowered.

Further, it has been attempted to suppress warpage during molding by using fine glass fibers, but this is not practical because of high cost.

[Problems to be solved by the invention]

The present invention improves the drawbacks of such conventional glass fiber reinforced polyolefin, and has excellent balance of mechanical strength such as impact strength and rigidity, heat distortion temperature, surface hardness, moldability, and the like. An object of the present invention is to provide a modified polyolefin resin composition containing ordinary glass fibers, in which warpage is significantly suppressed.

[Means for solving problems]

The present inventors have conducted intensive studies to achieve the above-mentioned object, and as a result, the modified polyolefin can be achieved by adding glass fiber, an elastomer and a plate-like inorganic filler in a specific ratio. The present invention has been completed, and the present invention has been completed based on this finding.

That is, the present invention is a composition comprising a weight% elastomer, a weight% plate-like inorganic filler b%, glass fiber c weight% and the balance modified polyolefin, wherein a and b are:
Expressions b ≧ 1 / 3a, b ≧ −2a + 25, b ≦ a + 24, b ≦ −2a + 54 are satisfied, and c is expression 20 ≦ c ≦ 40, 0.107c ² − (7.2−0.0725a−0.0482b) c −3.63a−2.15b
The present invention provides a modified polyolefin resin composition characterized by satisfying the relationship of + 0.0786a ² + 0.0923ab + 0.0106b ² + 95.7 ≦ 0.

Examples of the modified polyolefin used in the composition of the present invention include unsaturated carboxylic acids, derivatives of unsaturated carboxylic acids, chlorine, polyethylene modified with vinylsilane,
Examples thereof include polypropylene and ethylene-propylene copolymer. As the unsaturated carboxylic acid used for the modification,
Examples thereof include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, citraconic acid, sorbic acid, mesaconic acid, angelic acid, and the like, and as the derivative of the unsaturated carboxylic acid, an acid anhydride or an ester. , Amides, imides, metal salts, and the like, for example, maleic anhydride, itaconic anhydride, citraconic anhydride, methyl acrylate, methyl methacrylate, ethyl acrylate, butyl acrylate, maleic acid monoethyl ester, acrylamide, arrayin. Examples thereof include acid monoamide, maleimide, N-butyl maleimide, sodium acrylate, sodium methacrylate and the like.

Among the various modified polyolefins described above, polypropylene modified with maleic anhydride or acrylic acid is particularly preferable.

The addition amount of the modifier in the modified polyolefin is preferably in the range of 0.01 to 5% by weight. In this case, the unmodified polyolefin may be modified so that the amount of the modifier added is in the range of 0.01 to 5% by weight, or a modified polyolefin to which a high concentration of the modifier is added is prepared. Blended with the polyolefin of
You may adjust so that it may be 0.01 to 5 weight%.

In this modification, organic peroxides such as benzoyl peroxide, lauroyl peroxide, dicumyl peroxide and t-butyl hydroperoxide are usually used in order to promote the modification degree, and the amount thereof is 100 parts by weight of polyolefin. On the other hand, it is preferably selected in the range of 0.01 to 3.0 parts by weight.

The method for producing the modified polyolefin is not particularly limited, but, for example, a polyolefin, an unsaturated organic acid or a derivative thereof and an organic peroxide are blended, sufficiently mixed with a Henschel mixer, and heated and melt-kneaded at a temperature not lower than the melting point of the polyolefin. Can be used.

The glass fiber used in the composition of the present invention is not particularly limited, and any glass fiber conventionally used for resin reinforcement can be used, but the fiber diameter is 9 to 13
Alkali-free glass fibers of μm are preferred. The form of the glass fiber is not particularly limited and may be any of roving, chopped strands, strands, etc., but if the fiber diameter is too large, the strength of the composition may decrease, and the appearance may deteriorate. On the other hand, if it is too thin, the fibers may be broken during kneading or molding and the strength may be reduced.

In order to obtain a composition having more excellent heat resistance and mechanical strength, this glass fiber is optionally combined with a coupling agent such as aminosilane-based, epoxysilane-based, borane-based, vinylsilane-based, methacrylosilane-based, or a chromium complex. You may use after surface-treating with a compound, a boron compound, etc.

Examples of the elastomer used in the composition of the present invention include ethylene propylene rubber, ethylene propylene diene rubber, styrene butadiene rubber, styrene butadiene ethylene styrene rubber, acrylic rubber, epichlorohydrin rubber, and butadiene rubber.
Of these, Mooney viscosity ML _{1 + 4} (100 ° C) is preferred.
Ethylene propylene rubber having a ratio of 10 to 100, more preferably 20 to 70 is suitable.

Examples of the plate-like inorganic filler used in the composition of the present invention include talc, mica, sericite, glass flakes, clay and the like. Among these, talc, mica and sericite having an aspect ratio of 5 or more are It is suitable.

In the composition of the present invention, the elastomer content is a% by weight, the plate-like inorganic filler content is b% by weight, the glass fiber content is c% by weight, and the modified polyolefin content is {100- ( a + b + c)}% by weight,
And b must satisfy the relations of the formulas b ≧ 1 / 3a, b ≧ −2a + 25, b ≦ a + 24, b ≦ −2a + 54. When b <1 / 3a, the surface hardness is low, and when b <−2a + 25, the warpage during molding is large. On the other hand, when b> a + 24, the impact strength is low, and when b> -2a + 54, the heat distortion temperature is low. Preferably, a and b are expressed by the formulas b ≧ 1 / 2a, b ≧ −2a + 30, b ≦ a + 20, b ≦ −2a + 50. It is desirable to satisfy the relationship.

FIG. 1 is a graph showing the relationship between a and b, where the horizontal axis represents a and the vertical axis represents b. In this figure, a region surrounded by a solid line is a variable range of a and b in the essential condition of the present invention, and a region surrounded by a dotted line is a variable range of a and b in a preferable condition. As can be seen from this figure, the variable range of a and b is 1/3 each.
~ 162/7, 75/21 ~ 34.

From such a relationship between a and b, arbitrary values of a and b are selected within the above range, and c is calculated from the values of a and b.
Formula 20 ≦ c ≦ 40 and 0.107c ² − (7.2−0.0725a−0.0482b) c−3.63a−2.15b
+ 0.0786a ² + 0.0923ab + 0.0106b ² + 95.7 ≦ 0 Preferably 0.107c ^2- (7.2-0.0725a-0.0482b) c-3.63a-2.15b
+ 0.0786a ² + 0.0923ab + 0.0106b ² +100.7 ≤ 0 More preferably 0.107c ^2- (7.2-0.0725a-0.0482b) c-3.63a-2.15b
It is determined by + 0.0786a ² + 0.0923ab + 0.0106b ² + 105.7 ≦ 0.

If c is larger than the value in this range, the moldability is deteriorated and the appearance is deteriorated. On the other hand, if it is smaller than the value in this range, the heat resistance is deteriorated and the warpage during molding is increased. The range of c determined by the quadratic inequality, which depends on a and b, is approximately 8.5 <c <47.

In the composition of the present invention, when the values of a, b and c satisfy the above formula, warpage, heat distortion temperature, impact strength and surface hardness are well balanced and each shows a high value.

The composition of the present invention can be prepared by heating and kneading each component using a normal kneader such as a single-screw extruder, a twin-screw kneader, a Banbury mixer, a roll, a Brabender, and a kneader. It is preferable to use a shaft kneader to prepare only glass fibers by side-feeding from the middle of the kneader. When an organic peroxide is added during this kneading, the effect of suppressing warpage is further improved.

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) hexyne-3,2,5-dimethyl-2,5
-Di- (t-butylperoxy) hexane, t-butylperbenzoate, t-butylperphenylacetate, t-butylperisobutyrate, t-butylper-
sec-octate, t-butyl perpivalate, cumyl perpivalate, t-butyl perdiethyl acetate,
Examples thereof include dichlorobenzoyl peroxide. Of these, benzoyl peroxide,
Lauroyl peroxide, dicumyl peroxide,
Preferred are 1,3-bis (t-butylperoxyisopropyl) benzene and the like.

The blending amount of these organic peroxides is 0.005 to 0.1 part by weight, preferably 0.01 to 0.05 part by weight, based on 100 parts by weight of the modified polyolefin resin composition.

The heat treatment is performed by melt-kneading at a temperature of 200 to 260 ° C, preferably 210 to 250 ° C. Treatment time is 0.1 to 5 minutes, preferably 0.3 to 3
Minutes.

The composition of the present invention is usually kneaded in an extruder or the like to form a pellet-shaped compound, and then subjected to processing.In a special case, each component is directly supplied to various molding machines and kneaded in the molding machine. It can also be molded. As the molding processing method, methods such as extrusion molding, hollow molding, injection molding, sheet molding, thermoforming, rotational molding, and laminated molding can be used.

〔Example〕

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

In addition, each physical property was calculated | required as follows.

Tensile strength: Compliant with JIS K 7113 Bending strength: Compliant with JIS K 7203 Bending elastic modulus: Compliant with JIS K 7203 Izod impact strength: Compliant with JIS K 7110 (using notched test piece) Heat distortion temperature: Compliant with JIS K 7207 Warpage rate: A disk with a diameter of 150 mm and a thickness of 3 mm is formed from the obtained pellet, the obtained disk is placed on a flat plate, and the warpage height from the plate surface to the warped part of the disk ( Shown in FIG.
D ₁ , D ₂ ) was measured and the warpage rate was calculated by the following formula.

⊚: Warp rate value is 0 to 2% ◯: Warp rate value is 2 to 4% △: Warp rate value is 4 to 6% ×: Warp rate value is 6% or more Surface hardness: Rockwell hardness JIS K According to 7202 Production Example 1 Production of Modified Polyolefin A 99 parts by weight of polypropylene (Idemitsu Polypro 750H) and 1 part by weight of modified polypropylene (Idemitsu Polytac H-1000P) with a maleic acid addition amount of 5% by weight are melt-kneaded by a uniaxial extruder. And pelletized to produce a modified polyolefin A.

Production Example 2 Production of Modified Polyolefin B Polypropylene (MI8g / 10min, density 0.90, in a three-neck separable flask with an internal volume of 1 equipped with a stirring blade and a reflux device,
Product name Idemitsu Polypro J750H) 100 parts by weight of terminally hydroxylated 1.2-polybutadiene (number average molecular weight 2000,
Product name: Nisso PBG-2000 Nippon Soda Co., Ltd. 5 parts by weight,
Maleic anhydride 20 parts by weight, dicumyl peroxide 1.72
1 part by weight and 600 parts by weight of xylene were charged, heated in an oil bath using a heater, stirred, reacted at 120 ° C. for 1 hour, and then continued at 140 ° C. for 3 hours. After completion of the reaction, the mixture was cooled, precipitated in a large excess of acetone, suction-filtered, and further dried (70 ° C. for 50 hours) to obtain a white powdery polymer (modified polyolefin B). The amount of added maleic anhydride in this polymer was 0.5% by weight.

Production Example 3 Production of Modified Polyolefin C In Production Example 2, instead of 20 parts by weight of maleic anhydride,
Modified Polyolefin C was obtained in the same manner as in Production Example 2 except that 10 parts by weight of acrylic acid was used. The amount of acrylic acid added to this product was 2.0% by weight.

Examples 1 to 17 and Comparative Examples 1 to 9 Other components except glass fiber were blended with a Henschel mixer, and then fed to a hopper of a twin-screw kneader with a constant amount feeder, while glass fiber was side-fed with a constant amount feeder. Then, an organic peroxide was added if necessary, and the mixture was melt-kneaded at 220 ° C. to obtain pellets.

After drying the obtained pellets at 100 ° C. for 3 hours, a test piece and a disk of 150 mmφ were molded with an injection molding machine, and each physical property was measured. The results are shown in the table.

In the column of modified polyolefin in the table, D is an unmodified polyolefin of Idemitsu Polypro J750H.

[Effects of the Invention] The glass fiber reinforced modified polyolefin resin composition of the present invention is a modified polyolefin in which an elastomer, a plate-like inorganic filler and glass fibers are blended in a specific ratio, and has impact strength, rigidity and heat. In addition to having a good balance of deformation temperature, surface hardness, moldability, etc., it also has excellent features such as extremely small warpage during molding, and is suitable as a molding material in the fields of automobiles, home appliances, and other industrial fields. Used.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the amount of elastomer and the amount of plate-like inorganic filler in the composition of the present invention, and the region surrounded by a solid line is the amount of elastomer and the plate-like inorganic filler under the essential conditions of the present invention. The range in which the amount can vary, and the region surrounded by the dotted line is the range in which the preferable condition can vary. FIG. 2 is an explanatory diagram for measuring the warpage rate of the molded body.

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Claims (1)

[Claims] 1. An elastomer a% by weight, a plate-like inorganic filler b.
%, Glass fiber c% by weight, and the balance consisting of modified polyolefin, wherein a and b satisfy the following formulas: b ≧ 1 / 3a, b ≧ −2a + 25, b ≦ a + 24, b ≦ −2a + 54, And c is the formula 20 ≦ c ≦ 40, 0.107c ² − (7.2−0.0725a−0.0482b) c−3.63a−2.15b
A modified polyolefin resin composition characterized by satisfying the relation of + 0.0786a ² + 0.0923ab + 0.0106b ² + 95.7 ≦ 0.