JPS6365223B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a filler-reinforced resin composition that has excellent dimensional stability, good moldability and paintability, and a high balance of physical properties (especially heat-resistant rigidity and low-temperature impact). Conventionally, metal has been widely used for automobile interior and exterior parts such as bumpers, bumper skirts, fascias, fenders, and trims, but in recent years, the use of propylene-based resin materials has increased and is being replaced by them. For example, paint performance for bumpers, facias, fenders, etc.
Propylene-based resins with improved appearance, low-temperature impact performance, etc. are being applied. Many proposals have been made regarding these improvement methods. In other words, ethylene-propylene copolymer rubber (hereinafter referred to as EPR) is blended mainly to improve paintability and impact resistance.
Attempts have been made to fill inorganic fillers such as talc to improve stiffness (Japanese Patent Application Laid-Open No. 57-55942, 57-
159841, 57-159842, 58-111846, 58-
168648, 58-213043). However, as products used in this field tend to have increasingly diversified designs and larger sizes, the materials used need to be improved in terms of dimensional stability, heat-resistant rigidity and low-temperature impact balance, moldability, and paintability. However, these prior art technologies have not been able to satisfy these demands. The present invention aims to meet such requirements by blending a specific crystalline propylene-ethylene block copolymer (hereinafter referred to as EPP), an ethylene polymer (hereinafter referred to as PE), EPR, and talc in a specific ratio. As a result, it exhibits excellent appearance, moldability, rigidity-low-temperature impact strength balance, and extremely excellent dimensional stability and paintability (particularly in terms of paint performance, surface treatment with solvents has a large effect on the quality of partial paintability). The degree of change in gloss: If this degree is large, the gloss will be different from the unpainted area, resulting in poor appearance. Note that the paintability also includes initial adhesion, resistance to solvent treatment to reduce gloss, moisture resistance, hot water resistance, and the like. That is, the present invention is a filler-reinforced resin composition characterized by comprising each of the following components (a) to (d). (a) Contains 5-12% by weight of boiling xylene solubles with an ethylene content of 25-50% by weight, an ethylene content of the entire polymer of 1-7% by weight, and an MFR of 30-80
g/10 min propylene-ethylene block copolymer resin 55-64% by weight (b) Density 0.930 g/cm ³ or more and MFR 5-30 g/10
(c) Ethylene-propylene copolymer rubber with a propylene content of 25-50% by weight and a Mooney viscosity ML ₁₊₄ (100°C) of 40-60 29-26% by weight % (d) Specific surface area is 35000cm ² /g or more, average particle size is 0.3
~2.2μ, aspect ratio of 4 or more and particle size distribution of 10μ or less is 97% or more, 5μ or less is 87%
Above, 1μ or less is 5-95% talc 12-8
Weight % (However, the above specific surface area means the value measured by an air permeation method, and the average particle size and particle size distribution mean the values measured by a liquid phase sedimentation method light transmission method.) The composition of the present invention is used, for example, in automobiles. It enables high-quality applications in the field of industrial parts such as parts and home appliance parts, especially in the field of large automobile parts such as bumpers, bumper skirts, facias, and fenders. The EPP used in the present invention as the component (a) has a boiling xylene soluble content of 5 to 50% by weight with an ethylene content of 25 to 50% by weight.
12% by weight (preferably 5 to 10% by weight), the ethylene content of the entire polymer is 1 to 7% by weight (preferably 1 to 5% by weight), and the MFR is 30 to 80 g/10 min. Here, the ethylene content is the value measured by conventional methods such as infrared spectrometry and NMR methods, and the boiling xylene soluble content is measured by immersing 2 g of the sample in 600 g of boiling xylene for 20 minutes to dissolve it, then room temperature. This value is calculated from the weight of the solid phase obtained by cooling the sample to 100%, filtering it through a G4 type glass filter, and drying it. If the ethylene content and boiling xylene soluble content of the copolymer are outside the above ranges, the composition will have poor dimensional stability, paintability, appearance, and balance of physical properties, making it unsuitable. In addition, MFR is a value measured according to JIS-K7210 (230℃, 2.16Kg load), and anything less than 30g/10 minutes has poor moldability, appearance, and paintability, and anything over 80g/10 minutes is a normal value. Not suitable for molding. Conventional stereoregular catalysts are used in the production of this copolymer. Typically, there is a mixed catalyst of a halogenated titanium compound or a supported titanium catalyst component and a halogenated organoaluminium compound, and if necessary, an electron-donating compound such as benzoic acid may be added, or by means such as co-pulverization. You can use the activated one. As a polymerization method, the special public interest law
1836, 44-16668, 49-30264, Unexamined Japanese Patent Publication 1973-
The method described in Publication No. 11529 is used. Further, the MFR may be adjusted by using an organic peroxide such as diacyl peroxide or dialkyl peroxide that has been polymerized in advance. The isotactic index (II) of this copolymer is 40 or more, preferably 60 or more,
A score of 90 or above is especially desirable. Here, this copolymer may be a mixture of two or more resins as long as the properties are within the above property range. It can also be used in an amount not exceeding the amount (weight) of . In addition, this EPP may contain other unsaturated monomers (for example, α-olefins such as butene-1, hexene-1, octene-1, 4-methylpentene-1, etc.) to the extent that the effects of the present invention are not significantly impaired. ; Vinyl esters such as vinyl acetate; (meth)acrylic acid (ester), unsaturated organic acids such as maleic anhydride, or derivatives thereof, etc.). It may be of any type). Furthermore, a mixture of these may be used. Next, PE, which is the component (b) used in the present invention, is
It has a density of 0.930g/cm3 or ^more , and types include ethylene homopolymer (polyethylene),
Ethylene and other α-olefins (e.g. propylene, butene, pentene, hexene, heptene, etc.)
Or unsaturated organic acids or their anhydrides (e.g. acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, etc.) or unsaturated esters (e.g. vinyl acetate, methyl acrylate, methyl methacrylate, etc.), vinyl silane, or aromatic Examples include block, random or graft copolymers of two or more elements with so-called vinyl monomers such as group vinyl compounds. Furthermore, a mixture of these polymers may also be used. In the case of the above copolymer of ethylene and other vinyl monomers, ethylene must account for at least a majority by weight. MFR of these PEs (JIS-K7210, 190℃, 2.16
Kg load) used is 5 to 30 g/10 minutes.
Furthermore, among these PEs, those having a density of less than 0.930 g/cm ³ are less effective in preventing changes in appearance and paint gloss, and are not preferred in terms of rigidity. These P.E.
Among these, high-density polyethylene is particularly preferred. Such PE not only further improves the ability to prevent paint gloss from changing, but is also effective in improving scratch resistance and impact resistance. Next, the above component (c) used in the present invention, EPR, is
Ethylene-propylene binary copolymer rubber (EPM)
or ethylene-propylene-nonconjugated diene terpolymer rubber (EPDM) with a propylene content (weight) of 25 to 50% and a Mooney viscosity of ML ₁₊₄ (100
C) is 40 to 60, and EPDM preferably has an iodine value of 20 or less. If the propylene content is less than 25% or more than 50%, the impact resistance of the composition is insufficient. Those with a Mooney viscosity of less than 40 have poor paintability and are more likely to cause mold delamination, while those with a Mooney viscosity of less than 40 are unsuitable because they have poor appearance (flow marks, etc.), paintability, and prevention of changes in paint gloss. It is. Here, if the Mooney viscosity range is 40 to 60, the EPR may be a combination of two or more components. for example,
It is like a blend of EPM and EPDM, high viscosity products and low viscosity products, and in this case, it is okay to use materials outside the viscosity range together. In addition, the talc, which is the component (d) used in the present invention, has a specific surface area of 35000 cm ² /g or more and an average particle size of 0.3
~2.2μ, the particle size distribution is virtually all below 15μ,
10μ or less is 97% or more, 5μ or less is 87% or less, and 1μ
The following are 5-95%. If the composition does not fall within the above range, the dimensional stability of the composition will be poor, and the rigidity-low-temperature impact balance, paintability, and appearance will be poor, which is not preferable. Here, the specific surface area is measured using a constant pressure aeration type specific surface area measuring device, such as a powder specific surface area measuring device SS-100 manufactured by Shimadzu Corporation, based on a conventional method, the so-called air permeation method. Further, the particle size distribution is measured by an integrated distribution value by a light transmission method using a liquid phase sedimentation method. An example of a measuring device is the SA-CP model manufactured by Shimadzu Corporation (for example,
SA-CP2-20) or the SKN type manufactured by Seishin Enterprises (for example, the SKN-1000 type). On the other hand, the average particle size is 50% of the particle size cumulative distribution curve measured with the same device as the particle size distribution measurement device.
This is the particle size value at the point. In addition, the above-mentioned physical properties of the filler dispersed in the resin can be obtained by boiling point extraction of this composition with an organic solvent (for example, dipping and dissolving in xylene at 130 to 140°C for about 10 hours, passing it through a cylindrical paper and adding it to talc. The filler obtained by separating the resin or by firing the composition can be determined by the above method. Incidentally, the average value of the aspect ratio, which indicates the ratio between either the vertical or horizontal length and the thickness of this talc, is 4 or more. Talc with an average particle size of 1.5μ or less can be easily obtained by wet classification, and talc with an average particle size of 0.7μ or more can be obtained by dry classification. Such talc is produced, for example, by the following classification method. That is, talc raw stone is crushed using a device such as a tube mill type crusher, an impact type crusher, a micron mill type crusher, a centrifugal roller type Raymond mill, etc., and if fine crushing is required, a micron mill, a jet type crusher, Jet-O.
Miser, micronizer, jet pulverizer, stirring mill (tower mill), vibration mill,
Dry or wet pulverize using a coloyl mill, etc. Next, these crushed talc are passed through a cyclone,
Dry or wet classification is performed once or multiple times using equipment such as Multilon, Micron Separator, Micronplex, Cyclone Air Separator, Ultra Separator, Jet Chron, Cracyclon, Rake Classifier, Hydrocyclone, Hydraulic Classifier, Centrifugal Classifier, etc. and adjust its physical properties. The blending ratio of components (a) to (d) as above is (a) + (b) +
(a) 55-64% by weight, (b) 2-4% by weight, (c) 26-29% by weight, (d) 8-12% by weight, based on the total amount of (c) + (d), respectively. It is. If component (a) is less than the above range, the moldability and mechanical strength are unsatisfactory, while if it is in excess, the dimensional stability and rigidity are unfavorable. Furthermore, if the component (b) exceeds the above range, no further improvement in the effect of preventing paint gloss change, appearance, impact resistance, or scratch resistance can be expected, and it is not preferable in terms of heat resistance and rigidity. Furthermore, those containing component (c) below the above range are inferior in paintability and low-temperature impact resistance, and those in excess are unsuitable because they are inferior in rigidity, dimensional stability, and scratch resistance. Further, if the content of component (d) is less than the above range, the dimensional stability will be significantly inferior and the rigidity will be insufficient, while if it exceeds the above range, the appearance, paintability, moldability, and low temperature impact will be poor, making it undesirable. In addition to the above-mentioned components, the composition of the present invention may contain other additional components as long as the effects of the present invention are not significantly impaired. These additional components include treated or untreated inorganic or organic fillers other than talc used in the present invention; rubber or latex components other than EPR used in the present invention; thermoplastic resins other than EPP and PE used in the present invention; Thermosetting resin; In addition, there are various stabilizers, pigments, dispersants, cross-linking agents, foaming agents, flame retardants, nucleating agents, antistatic agents, paintability improvers, etc., but the addition of fillers as additional ingredients is It is effective in improving plating properties, paintability, adhesion, gloss, moldability, tucking properties, kneading properties, weld strength, creep resistance, dimensional stability, heat resistance, etc. In addition,
The addition of calcium carbonate, barium sulfate, titanium oxide, and zinc oxide significantly improves these effects. The composition of the present invention can be produced using a conventional kneading machine such as a single-screw extruder, a twin-screw extruder, a Banbury mixer, a roll, a Brabender plastograph, or a kneader. Usually, it is kneaded in an extruder or the like to form a pellet-like compound and then subjected to processing, but in special cases, the four components can be directly fed to various molding machines and molded while being kneaded by the molding machine. Alternatively, talc or EPR can be kneaded in advance at a high concentration (with various additives as necessary) to form a masterbatch, and then diluted with propylene polymer etc. separately for blend compounding or molding. can. The molding method of the composition of the present invention is not particularly limited, and regardless of the molding method such as extrusion molding, blow molding, injection molding, sheet molding, thermoforming, rotational molding, lamination molding, etc., the molded product according to the present invention may be formed. Of these, injection molding is the most suitable. The composition of the present invention thus obtained has excellent dimensional stability and paintability that conventional filler-reinforced resin compositions do not have, as well as a high balance of physical properties (rigidity - low temperature impact), good appearance, Has moldability,
In addition, sink marks and warping are not noticeable, and printability and adhesion are excellent.
It has good scratch resistance, hardly noticeable weld lines, and good weld strength and tensile elongation. EXAMPLES The present invention will be specifically described below with reference to Examples. The various measurement methods used here are as follows. (1) Dimensional stability: Linear expansion coefficient measured according to ASTM-D696. However, the temperature range is -30℃ to 120℃ (2) MFR: Based on JIS-K7210 (230℃, 2.16℃)
Kg). However, for PE (190℃, 2.16Kg) (3) Flexural modulus: Compliant with JIS-K7203 (23℃). (4) Dart impact strength: A dart, which is a load sensor, was dropped onto a test piece (100 x 100 x 2 mm each) installed on a support (hole diameter φ40 mm) (2 m x 7 kg).
f) The deformation and fracture behavior of the test piece under impact load was measured, and the impact energy absorbed up to the point of crack initiation in the resulting impact pattern was calculated and used as the impact strength of the material. The measurement atmosphere temperature is -30°C. (5) Measurement of surface gloss reduction: Injection molded product (100×100
x 2 mm) and 1,1,1-trichloroethane steam cleaning for 30 seconds, the glossiness was measured and designated as GO and G, respectively, and compared. Generally, G has a lower value than GO, and if the decrease is large, a difference in gloss will occur between the solvent-treated area and the untreated area, reducing the commercial value. Note that the glossiness was measured at an incident angle of 60° and a light receiving angle of 60° in accordance with ASTM-D523. The evaluation is as follows: ◎: Good gloss with very little loss of gloss. ○: There is little reduction in gloss and there is no problem in practical use. △: Gloss reduction is considerably large and not suitable for practical use. ×: Gloss is significantly decreased and gloss is poor. (6) Painting method: After exposing the test piece to 1,1,1-trichloroethane vapor for 30 seconds, apply primer for polypropylene (RB-291 manufactured by Nippon B Chemical Co., Ltd.)
Spray paint to a film thickness of approximately 10μ and heat at 90℃.
After baking for 20 minutes and cooling, apply two-component urethane paint (R-263 manufactured by Nippon B Chemical Co., Ltd.).
Spray paint to a film thickness of approximately 30μ and heat at 90℃.
I baked it for 40 minutes. (7) Initial adhesion of paint film: After leaving the paint test piece prepared in (6) at room temperature for two days and nights, use a cutter to insert 10 squares of 2 mm square into the paint film, totaling 100 squares, and place 24
A piece of cellophane tape (manufactured by Nichiban Co., Ltd.) with a width of mm was pasted, and this was rapidly peeled off in a direction perpendicular to the painted surface, and the number of squares that had not been peeled off was counted. (8) Paint film moisture resistance test: The painted test piece prepared in (6) was left at a good temperature for two days and nights, and then hung in a constant temperature and humidity chamber maintained at 50°C and 95% RH for 240 hours. 2 taken out
After an hour, a grid test similar to (7) was performed. (9) Paint film hot water resistance test: After leaving the painted test piece prepared in (6) at room temperature for 2 days and nights, it was placed in a constant temperature water bath at 40°C for 240°C.
Soaked for an hour. Two hours after removal, a grid test similar to (7) was conducted. Example Each component in Tables 1 to 4 was blended as shown in Table 5, and 100 parts by weight of the blend was further added with 2,6-di-
0.08 parts by weight of t-butyl-p-phenol, 0.1 parts by weight of tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane and 0.5 parts by weight of carbon black. When the blended filler is talc, mix it for 2 minutes with a super mixer made by Kawada Seisakusho, or if the blended filler is glass fiber, mix it with a tumbler blender for 15 minutes, and then mix it with an FCM twin-shaft kneader.
A composition was obtained by kneading and granulating at 230°C. After this, with a screw in-line injection molding machine
Form specimens at 230℃ and check their dimensional stability, paintability,
Appearance and physical properties were evaluated. As a result, compositions No. 1 to 3 showed a good quality balance. That is, the linear expansion coefficient was small, there was very little change in gloss due to solvent treatment, and in addition to showing good paintability, it also showed a practically sufficient balance of physical properties and good moldability. On the other hand, Nos. 4 to 14 had poor quality balance. That is, the dimensional stability was poor, the appearance was poor, the balance of physical properties was at a low level, and the paintability was poor.

[Table] (Note) * Adjusted by treatment with organic peroxide

【table】

【table】

【table】

[Table] Using the composition of Reference Example No. 1, width 300 x length 600 x thickness 3
(mm) modem flat plates were molded to be used as industrial parts such as bumpers, bumper skirts, trims, and other automobile parts. The molding fluidity at this time was extremely good, the appearance was beautiful, and no sink marks or warpage were noticeable.
The obtained molded product not only has good dimensional stability at high temperatures (80°C), but also has sufficient heat-resistant rigidity, low-temperature impact strength, and paintability for practical use, and satisfies weld strength, appearance, and scratch resistance. It was hot.

Claims (1)

[Scope of Claims] 1. A filler-reinforced resin composition comprising the following components (a) to (d). (a) Contains 5-12% by weight of boiling xylene solubles with an ethylene content of 25-50% by weight, an ethylene content of the entire polymer of 1-7% by weight, and an MFR of 30-80
g/10 min propylene-ethylene block copolymer resin 55-64% by weight (b) Density 0.930 g/cm ³ or more and MFR 5-30 g/10
(c) Ethylene-propylene copolymer rubber with a propylene content of 25-50% by weight and a Mooney viscosity ML ₁₊₄ (100°C) of 40-60 29-26% by weight % (d) Specific surface area is 35000cm ² /g or more, average particle size is 0.3
~2.2μ, aspect ratio of 4 or more and particle size distribution of 10μ or less is 97% or more, 5μ or less is 87%
Above, 1μ or less is 5-95% talc 12-8
Weight% (However, the above specific surface area means the value measured by the air transmission method, and the average particle size and particle size distribution mean the values measured by the liquid phase sedimentation method light transmission method.)