JP3450474B2 - Fibrous filler reinforced resin composition - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a mechanical strength balance, a creep resistance, a product suitable for parts around an engine, parts for vehicles such as wheel caps requiring heat resistance and rigidity, parts for various electric products and the like. The present invention relates to a fibrous filler-reinforced resin composition excellent in appearance and the like.

[0002]

2. Description of the Related Art Conventionally, a propylene-based polymer resin and a fibrous filler, and a propylene-based polymer resin modified with maleic anhydride or the like for imparting adhesiveness to these (hereinafter, referred to as
It is called "modified PP". It has been widely attempted to improve the heat resistance rigidity, mechanical strength, creep resistance, etc.

However, conventionally used modified P
P is mainly a method of performing a melt graft reaction in an extruder in the presence of an organic peroxide, for example, JP-A-3-13715.
No. 0 and No. 5-1184 often have a modification rate of about 0.2 to 2% by weight, and if the modification rate exceeds this, the content of the gel-like modified polymer resin is high. Not only is it unsuitable for use as a molding material, but a troublesome problem of remaining unreacted monomer arises, so that it is difficult to obtain a modified PP having a high modification rate in the manufacturing process. The modified PP has a number average molecular weight of 50,0.
A propylene-based polymer resin of about 00 is used, and since the molecular weight is too high, the adhesiveness between the propylene-based polymer resin and the fibrous filler is improved, and thus the heat-resistant rigidity,
The effect of improving mechanical strength, creep resistance and the like was poor, and improvement was required.

On the other hand, for example, as disclosed in JP-A-6-228376, a method of using a modified PP having a high modification rate of 3 to 5% by weight has been proposed. However, in the case of this modified PP, the molecular weight is 15 × 10 ⁴ to
It is as high as 20 × 10 ^4, and the effect of improving the adhesiveness is insufficient because there are many cases where the monomer is grafted to other than the polymer end, and this also requires improvement. In these conventional modified PPs, a large amount must be added to the propylene-based polymer resin composition for reinforcing the fibrous filler. For example, in the case of the modified PP having a modification rate of 0.5% by weight, the propylene-based polymer resin and A blending amount of 5 to 7 parts by weight is required with respect to 100 parts by weight of the total of the fibrous filler, which is not satisfactory in terms of product physical properties. Further, particularly in a propylene polymer resin composition which is a general-purpose resin. It was necessary to reduce the amount of compounding from the viewpoint of important low cost requirements.

As a method of graft-modifying a propylene polymer resin having a low molecular weight at a high modification rate, a method of carrying out a graft reaction in a solution of an organic solvent is considered,
With this method, the modification rate can be increased to about 5 to 7% by weight, and the unreacted monomer remaining in the modified PP can be reduced. However, the manufacturing process such as a device for dissolution and the removal of the organic solvent becomes complicated, and the manufacturing cost becomes high, which is not preferable.

[0006]

The object of the present invention is to solve the above-mentioned drawbacks of the prior art and to obtain a mechanical strength balance obtained by blending a small amount of modified PP, which is suitable for products requiring heat resistance and rigidity. Another object of the present invention is to provide a fibrous filler-reinforced resin composition excellent in creep resistance, product appearance and the like.

[0007]

[Means for Solving the Problems]

[Summary of the Invention] The present inventors have conducted extensive studies to solve the above problems, using a specific modified propylene-based polymer, and by specifying the blending amount thereof, it is possible to achieve the above object. The present invention was completed by finding out.

That is, the present invention provides the following component (a)
50 to 90 % by weight, component (b) to 10 to 50 % by weight, and component (c) to total 100 of component (a) and component (b).
S parts by weight relative to parts by weight, where the s parts by weight is the content of the component (b) p% by weight, the diameter of the fibrous filler is q μm
And a maleic anhydride content of the component (c) of r% by weight through a constant k of 0.2 or more and 1.5 or less, qrs /
The fibrous filler-reinforced resin composition is characterized in that it satisfies the relation of p = k. Component (a): Propylene polymer resin consisting of propylene homopolymer resin and / or propylene / ethylene block copolymer resin with melt flow rate of 1 to 500 dg / min Component (b): Surface treatment with silane coupling agent Fibrous filler component (c): number average molecular weight of 7,000 to 15,000
Maleic anhydride graft-modified polypropylene polymer having a maleic anhydride content of 3 to 12% by weight obtained by subjecting the propylene-based polymer and maleic anhydride to graft reaction conditions

[Detailed Description of the Invention] Component (a): Propylene-based Polymer Resin The propylene-based polymer resin used in the present invention has a melt flow rate (MFR) of 1 to 500 dg / min and is used for injection molding. It is preferably 10 to 500 dg / min, and particularly preferably 30 to 500 dg / min of a propylene homopolymer resin and / or a propylene / ethylene block copolymer resin. When the MFR is less than this range, the modified propylene-based polymer is poorly dispersed, the reinforcing effect is not sufficiently exhibited, and the heat resistance rigidity and impact strength are lowered. On the other hand, if it exceeds this range, the mechanical strength is poor. Here, the propylene / ethylene block copolymer resin is composed of a crystalline propylene homopolymerization portion (X unit portion) and a propylene / ethylene random copolymerization portion (Y unit portion), of which the Y unit portion is a block copolymer resin. The ethylene content is 5 to 40% by weight, and the ethylene content thereof is preferably 20 to 80% by weight, particularly 25 to 50% by weight from the viewpoint of surface impact strength. Also, X
The density of the unit portion is 0.9070 g / cm ³ or more, and particularly, 0.
9086 g / cm ³ or more is preferable from the viewpoint of heat resistance and rigidity.

The content of this Y unit is 2 g.
The sample is immersed in 300 g of boiling xylene for 20 minutes to dissolve it, then cooled to room temperature, and the solid phase thus deposited is filtered by a glass filter and dried to calculate back by the solid phase weight. .

The propylene-based polymer resin as the component (a) is produced by a slurry polymerization, a gas phase polymerization or a liquid phase bulk polymerization using a highly stereoregular catalyst in either a batch system or a continuous system. To be done. In producing the propylene / ethylene block copolymer resin, either polymerization unit may be polymerized first, but it is preferable to first form the X unit and then form the Y unit. A specific method for producing the propylene / ethylene block copolymer resin is a catalyst in which a solid phase component formed by contacting titanium tetrachloride, an organic acid halide and an organic silicon compound with magnesium chloride is combined with an organic aluminum compound component. A method can be mentioned in which propylene is homopolymerized first, and then random copolymerization with propylene and ethylene is carried out. At this time, in the block copolymer resin, in a range that does not significantly impair the effects of the present invention, for example, 15% by weight or less, other unsaturated monomers such as butene-1, hexene-1 and the like α −
Olefin: vinyl acetate, vinyl butyrate, and other vinyl esters; acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, methyl methacrylate, and other unsaturated carboxylic acids or their derivatives are copolymerized as constituents to form ternary or more It is also possible to use a copolymer of Further, the propylene polymer resin may be a combination of plural kinds of resins.

Component (b): Fibrous filler The fibrous filler used in the present invention is an inorganic or organic fibrous filler surface-treated with a silane coupling agent, and is, for example, glass fiber or wollastonite. Examples thereof include inorganic fibers such as various whiskers, polyamide fibers, polyester fibers, polyetherketone fibers and the like, and organic synthetic resin fibers having a melting point of 200 ° C. or higher. Among them, glass fiber is particularly preferable, and glass fiber having an average fiber diameter of 5 to 17 μm, particularly 6 to 13 μm is preferable in view of difficulty of production and appearance of the product.

As the silane coupling agent, aminosilane such as γ-aminopropyltriethoxysilane, γ
-Epoxy silanes such as glycoxypropyltrimethoxysilane and / or vinylsilanes such as vinyltrichlorosilane are preferred. The final adhesion amount of the sizing agent containing the coupling agent component for the purpose of adhesiveness / compatibility between the resin and the filler and the sizing agent for the sizing on the surface of the fibrous filler is the fiber disintegration property and the product. From the appearance, it is generally 0.01 to 1.5% by weight, preferably 0.1 to 0.4% by weight. As the focusing component, a resin having a film-forming property such as a urethane resin, a modified or unmodified olefin resin is usually used.

This preferred glass fiber is, as an example,
It can be manufactured by the following method. First, the melted glass is molded into a glass ball of a predetermined size called a marble, which is heated and softened in a molding furnace called a bushing and made to flow down from a large number of nozzles of the furnace table, and this base material is drawn at a high speed. On the other hand, a sizing agent coating device provided on the way dips the sizing agent so that the sizing agent is attached to the sizing agent, the sizing agent is dried and wound on a rotary drum. At this time, the nozzle diameter and the take-up speed are adjusted so that the average fiber diameter of the glass fibers becomes a predetermined value. At the same time, the concentration, type and application time of the sizing agent are adjusted so that the final amount of the sizing agent attached after drying falls within the above range.

Further, the length of the glass fiber is not particularly limited, and therefore the shape may be any of roving, chopped strand, strand and the like, but the chopped strand having a length of about 1 to 8 mm is kneaded with the propylene polymer resin. Is preferred. The number of bundles at this time is usually 1
The number is preferably 00 to 5000, and particularly preferably 500 to 2000. As long as an average length of 0.1 mm or more after kneading with a propylene-based polymer resin can be obtained, so-called milled fiber or a pulverized product of strands called glass powder may be used, or a continuous short fiber sliver shape It can be one. The composition of the raw material glass is preferably non-alkali, and E glass is an example.

Component (c): Modified propylene-based polymer The modified polypropylene-based polymer used in the present invention comprises a propylene-based polymer having a number average molecular weight of 7,000 to 15,000 and maleic anhydride as graft reaction conditions. It is a maleic anhydride graft modified propylene polymer having a maleic anhydride content of 3 to 12% by weight, preferably 4 to 10% by weight. The propylene-based polymer used here is preferably a propylene-based polymer having a weight average molecular weight / number average molecular weight ratio (Mw / Mn) of 1.5 to 3, particularly 2 to 3.

Examples of the propylene-based polymer include homopolymers of propylene, block or random copolymers of propylene containing propylene as a main component with other α-olefins, propylene containing propylene as a main component and other unsaturated compounds. Polymers such as copolymers with monomers, which may be resin-like or rubber-like, can be used, but resin-like ones are preferable.

If the maleic anhydride content is below this range,
There is a problem that the amount of the modified propylene-based polymer necessary for interfacial adhesion between the above-mentioned components (a) and (b) becomes too large and the mechanical strength decreases, while if it exceeds this range, There is a problem that a modified propylene-based polymer having an excessively low molecular weight is generated to similarly lower the mechanical strength, which is not preferable. If the number average molecular weight is less than this range, the compatibility with the above-mentioned component (a) becomes poor and the reinforcing effect cannot be sufficiently exhibited. On the other hand, if the number average molecular weight exceeds this range, the maleic anhydride graft-bonded to the terminal per molecule is not produced. If the amount is too small, the reinforcing effect cannot be sufficiently exerted, which is not preferable. The maleic anhydride content, which is the modification rate, was ¹³
It is measured by C nuclear magnetic resonance spectroscopy, infrared absorption spectroscopy, or the like.

Such a maleic anhydride graft-modified propylene-based polymer is melt-grafted by a solution method in which a graft reaction is carried out in a solution of an organic solvent, or by an extruder, roll, Brabender plastograph, kneader blender, Banbury mixer or the like. It can be obtained by subjecting the propylene polymer and maleic anhydride to the graft reaction conditions by a method such as a melting method. As an example, a particularly preferable method will be described below.

First, the number average molecular weight of 50,000 to 15
A number average molecule having a carbon-carbon double bond at least at one end by thermal degradation of 10,000 propylene-based polymer in an inert gas at 300 to 450 ° C. for 0.5 to 10 hours.
The amount 7, 000～150,000 and Mw / Mn1.5~
A propylene-based polymer of 3 is produced. Maleic anhydride is added to this, and it melt | dissolves in 150-250 degreeC in inert gas. Then, an azo compound-based radical generator such as 1,1′-azobis (cyclohexane-1-carbonitrile) is added to this, and in the presence of it, the reaction is subjected to a graft reaction condition, and after the reaction, depressurization is performed by depressurizing. To obtain a modified propylene-based polymer. By manufacturing by this method,
Since maleic anhydride can be selectively graft-bonded to the terminal of a low molecular weight propylene-based polymer, a small amount of it can effectively act to improve the adhesion between the above-mentioned components (a) and (b). You can

Mixing ratio of each component As for the mixing ratio of each component, the component (a) is 50 to 90 % by weight, the component (b) is 10 to 50 % by weight, and the component (c) is the component (a) and the component (a). S for 100 parts by weight of (b)
Parts by weight, where s parts by weight is the content p of the component (b) p
0.2% or more between the weight%, the diameter qμm of the fibrous filler and the maleic anhydride content r weight% in the component (c).
It is a mixing ratio that satisfies the relationship of qrs / p = k via a constant k of 1.5 or less.

The range of blending amounts of the component (a) and the component (b) is defined in view of difficulty of the kneading step and molding step, mechanical strength, product appearance and the like. Therefore, if the content of these components is outside the above range, it is not preferable from these viewpoints. Regarding the blending amount of the component (c), if the value of the constant k is too low, the amount required for improving the adhesiveness between the component (a) and the component (b) will be insufficient and the mechanical strength balance will decrease. On the other hand, when the value of the constant k is too high, the mechanical strength balance is deteriorated due to the excess amount of the compound and the product is colored, which is not preferable.

Optional Ingredients In the present invention, optional ingredients other than the above-mentioned essential ingredients can be further blended within a range that does not significantly impair the effects of the present invention. As an optional component, an antioxidant, a light stabilizer,
In addition to additives such as UV absorbers, nucleating agents, dispersants, colorants, flame retardants, foaming agents, molecular weight modifiers, fillers, various resins other than the above essential components, ethylene / propylene binary copolymer rubber (EPM), ethylene / butene-1 terpolymer rubber (EBM), ethylene / propylene / diene terpolymer rubber (EPDM), ethylene / propylene / butene-1 terpolymer rubber, styrene Examples include various elastomers such as rubber.

Production of Resin Composition (1) Kneading / Granulation An ordinary melt kneading machine, for example, a single-screw or twin-screw extruder, a Banbury mixer, a kneader blender, is prepared by blending the above-mentioned essential components and optional components. The fibrous filler-reinforced resin composition can be obtained by kneading using a mixing roll, Brabender Plastograph, Labo Plastomill or the like, and preferably granulating. In this case, all the components to be used may be kneaded together, but in order to more effectively develop the reinforcing effect of the fibrous filler, a method of kneading and granulation that allows good dispersion of each component. It is desirable that the component (a), the component (c) of the resin component and optionally the optional resin component are melt-kneaded in advance using a single-screw or twin-screw extruder, and the molten resin is then side-fed. A component (b) is added to the mixture and the mixture is melt-kneaded.

(2) Molding The fibrous filler-reinforced resin composition thus obtained is subjected to various molding methods, that is, injection molding, injection compression molding (press injection), compression molding, extrusion molding (sheet molding, film molding). , Blow molding, etc.), gas injection, etc. to form a product.

Application of Product The fibrous filler-reinforced resin composition of the present invention has superior heat resistance and rigidity, impact resistance, creep resistance, product appearance, etc., to those of conventional molding materials, Above all, it is suitable for parts around the engine, wheel caps, exterior plates, and the like. Further, the present invention can be applied not only to automobile parts but also to various plastic parts required to have heat resistance and rigidity.

[0027]

The present invention will be further described below with reference to specific examples. Evaluation method ○ Bending stress and bending elastic modulus: Measured at a temperature of 23 ° C and 110 ° C in accordance with JIS-K7203. ○ Heat distortion temperature: Based on JIS-K7207, load 1
Measured at 8.5 kgf. ○ Surface impact strength: Diameter 20m at measurement temperature 23 ° C
m and a load of 4 kg from a height of 2 m to 100 m
Drop onto an injection molded sheet of mx 100 mm x 2 mm,
Measure the impact absorption energy at that time. ○ Surface roughness: The average roughness of the center plane surface is measured according to JIS-B0601. ○ GF dispersion: Regarding the appearance of the surface of the molded product, the dispersion unevenness of the glass fiber (GF) was visually determined as follows. Best: There is no uneven dispersion of GF. Good: Almost no uneven dispersion of GF. Poor: Uneven dispersion of GF partially clouded is observed.

Raw material component (a) -all are pellets A1: 90% by weight of a crystalline polypropylene part (X unit part) having a density of 0.9089 g / cm ³ and an ethylene content of 3
9% by weight of propylene / ethylene random copolymerization part (Y unit) 10% by weight, and M of the whole component (a)
FR (230 ° C., 2.16 kg load) 0.5 dg / min propylene / ethylene block copolymer ○ A2: 90% by weight of crystalline polypropylene part (X unit part) having a density of 0.9090 g / cm ³ , ethylene content 3
9% by weight of propylene / ethylene random copolymerization part (Y unit) 10% by weight, and M of the whole component (a)
FR30 dg / min propylene / ethylene block copolymer ○ A3: Density 0.9090 g / cm ³ and MFR30
dg / min Crystalline propylene homopolymer ○ A4: 90% by weight of crystalline polypropylene part (X unit part) having a density of 0.9090 g / cm ³ , ethylene content 3
9% by weight of propylene / ethylene random copolymerization part (Y unit) 10% by weight, and M of the whole component (a)
FR300dg / min propylene / ethylene block copolymer

Component (b) -Glass fiber chopped strands each having a fiber length of 3 mm ○ B1: average diameter 10 µm, sizing agent adhesion amount 0.3% by weight, surface treatment with aminosilane ○ B2: average diameter 10 µm, sizing agent adhesion amount 0.3% by weight, no surface treatment ○ B3: average diameter 6 μm, amount of sizing agent attached 0.3% by weight, surface treatment with aminosilane

Component (c) -the following C1, C3, C4, C
6 is pellets, C2 and C5 are pulverized products. C1: Ethylene content 2.6% by weight, number average molecular weight 1
Modified propylene-based polymer obtained by grafting 4.5% by weight of maleic anhydride onto a crystalline propylene / ethylene random copolymer of 4,000 and Mw / Mn2.6 ○ C2: ethylene content 2.8% by weight, number average molecular weight Modified propylene-based polymer obtained by grafting 9% by weight of maleic anhydride to a crystalline propylene / ethylene random copolymer of 7,000, Mw / Mn2.7. C3: ethylene content 2.5% by weight, number average molecular weight 5
Modified propylene-based polymer obtained by grafting 0.7% by weight of maleic anhydride onto a crystalline propylene / ethylene random copolymer of 30,000 and Mw / Mn3.5.

○ C4: number average molecular weight 50,000, M
Modified propylene-based polymer obtained by grafting 0.7% by weight of maleic anhydride to a crystalline propylene homopolymer having w / Mn of 3.5 C5: ethylene content of 2.7% by weight, number average molecular weight of 4,000, Mw / Mn2 18% by weight of maleic anhydride to the crystalline propylene / ethylene random copolymer of No. 6
Grafted modified propylene-based polymer ○ C6: number average molecular weight 14,000, Mw / Mn2.
Modified propylene-based polymer obtained by grafting 4.5% by weight of maleic anhydride onto the crystalline propylene homopolymer of 6

Examples 1 to 10 and Comparative Examples 1 to 10 First, the above components (a) and (c) were blended in the proportions shown in Table 1 to 20 with a twin-screw extruder KTX44 manufactured by Kobe Steel.
The mixture was melted at 0 ° C., the component (b) was fed midway, and kneaded and granulated. The obtained pellets were evaluated by molding a test piece for evaluation using an injection molding machine IS100FB manufactured by Toshiba Kikai. The results are shown in Table 2. As shown in Table 2, each of the resin compositions of Examples showed a good mechanical strength balance as compared with the resin compositions of Comparative Examples. In addition, the resin compositions of all the examples had good creep resistance and molding appearance.

[0033]

[Table 1]

[0034]

[Table 2]

[0035]

According to the present invention, a fibrous filler-reinforced resin having excellent mechanical strength balance, creep resistance, product appearance and cost performance superior to those obtained by using a conventional modified PP. The remarkable effect that the composition is obtained is exhibited. Since this resin composition can be applied to various industrial parts, especially parts requiring heat resistance and rigidity, it can be an extremely important material in industry.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI (C08L 23/16 23:26) (56) Reference JP-A-2-6545 (JP, A) JP-A-59-226041 ( JP, A) JP 60-58465 (JP, A) JP 5-125111 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08L 23 / 00-23 / 36 C08L 3/00-13/08

Claims (3)

(57) [Claims] 1. The following component (a) is 50 to 90 % by weight, component (b) is 10 to 50 % by weight, and component (c) is 100 parts by weight in total of component (a) and component (b). On the other hand, s parts by weight, where the s parts by weight is between the content of component (b) p% by weight, the diameter of the fibrous filler q μm and the content of maleic anhydride in component (c) r% by weight. 0.2 or more to 1.5
A fibrous filler-reinforcing resin composition, characterized by satisfying the relationship of qrs / p = k via the following constant k. Component (a): Propylene polymer resin consisting of propylene homopolymer resin and / or propylene / ethylene block copolymer resin with melt flow rate of 1 to 500 dg / min Component (b): Surface treatment with silane coupling agent Fibrous filler component (c): number average molecular weight of 7,000 to 15,000
Maleic anhydride graft-modified polypropylene polymer having a maleic anhydride content of 3 to 12% by weight obtained by subjecting the propylene-based polymer and maleic anhydride to graft reaction conditions 2. The fibrous filler-reinforced resin composition according to claim 1, wherein the component (b) is a glass fiber surface-treated with aminosilane, epoxysilane and / or vinylsilane. 3. The component (c) has a number average molecular weight of 7,000.
To 15,000, a weight average molecular weight / number average molecular weight ratio (Mw / Mn) of 1.5 to 3, and a propylene polymer having a carbon-carbon double bond at least at one end and maleic anhydride as an azo compound radical. The fibrous filler-reinforced resin composition according to claim 1, which is a maleic anhydride graft-modified propylene-based polymer obtained by subjecting to graft reaction conditions in the presence of a generator.