JPS6397654A - Polypropylene resin composition containing talc - Google Patents

Abstract

PURPOSE:To provide the title compsn. which has excellent moldability and gives molded products having no flow mark and excellent high-temperature rigidity, impact resistance and gloss, by blending a specified highly crystalline propylene/ethylene block copolymer with an ethylene polymer and ultrafine talc particles having a treated surface. CONSTITUTION:70-95% (by weight; the same applies hereinbelow) C3H6 is polymerized in the presence of a catalyst composed of a combination of a solid product (a) obtd. by reacting an org. Al compd., etc. with TiCl4 and then reacting the reaction product with an electron donor and an electron acceptor with an org. Al compd. and an arom. carboxylic acid ester (b) in a molar ratio of (b) to (a) of 0.1-10.0 to obtain a C3H6 homopolymer having the relationship of the formula between an isotactic fraction P and MFR. 30-5% C2H4 is polymerized with said homopolymer in one or more stages to obtain a highly crystalline C2H4/C3H6 block copolymer (A) having a C2H4 content of 3-12% and an MFR of not lower than 4. 40-70% component A is blended with 20-30% C2H4 polymer (B) having a density of not lower than 0.94g/cm<3> and an MI of 10-50g/10min and 10-30% talc (C) having an average particle size of 0.2-3mu and a surface treated with a silane compd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to Merck-containing polypropylene resin compositions. More specifically, the present invention relates to a talc-containing polypropylene resin composition having high moldability and high temperature rigidity of the molded product, excellent impact resistance, and excellent appearance of the molded product.

[Prior art]

In recent years, automobile interior parts and parts for home appliances have increasingly been made of plastic for reasons such as weight reduction and economic efficiency.
Among them, 4 formability, economic efficiency, external shape of molded product, mechanical 1
Polypropylene resins are widely used because of their excellent strength, weather resistance, and durability. In addition, inorganic filler-containing polypropylene resin compositions are used for automotive interior parts, especially various parts around the instrument panels such as instrument panel lowers and console box Yakuro box outer parts, taking into account rigidity at high temperatures. ing.

However, although conventionally used inorganic filler-containing polypropylene resin compositions have high rigidity at high temperatures, it cannot be said that they have sufficient impact resistance at room temperature. In order to improve this drawback, compositions in which polypropylene is blended with a specific inorganic filler and a specific pigment, preferably polyethylene, and polypropylene resin compositions in which these are further blended with ethylene-propylene polymer rubber have been disclosed. ing. (Unexamined Japanese Patent Publication No. 59-10
8049, JP-A-59-108050) [
[Problems to be Solved by the Invention] However, it cannot be said that the surface appearance of the molded product obtained using the composition disclosed herein is sufficiently glossy, and the surface of the molded product has a tiger cub mark. (Hereinafter, 70
- This is called a mark, and refers to a state in which shiny parts and non-glossy parts appear alternately. ) appears.

In addition, the present inventors have previously developed polypropylene obtained by blending a specific crystalline propylene-ethylene block copolymer with an inorganic filler treated with a silane compound and a modified polypropylene modified with an unsaturated carboxylic acid or its anhydride. A resin composition was proposed. (jp#gansho 60-38
(No. 329) However, although the molded product obtained using the composition proposed here has excellent high-temperature rigidity, its impact resistance at room temperature is not sufficient, and the high-temperature rigidity,
It has been desired to develop a polypropylene resin composition that provides molded products with excellent impact resistance and appearance.

The present inventors continued to conduct intensive research in order to solve the above-mentioned problems regarding inorganic filler-containing polypropylene resin compositions. As a result, a composition made by blending a specific highly crystalline propylene-ethylene block copolymer with predetermined amounts of ultrafine talc particles surface-embedded with a specific ethylene polymer and a silane compound solved the above-mentioned problems once and for all. The present invention was completed based on this knowledge.

As is clear from the above description, one object of the present invention is to have good moldability, and when formed into a molded product, maintain high high temperature rigidity (flexural modulus at SO'C) and impact resistance. Excellent properties and appearance of molded products (glossy, flow marks)
K is also to provide excellent molded products.

[Means for solving problems]

The present invention has the following configuration.

The relationship between the isotactic pendant fraction (P) and melt 70-ray (MFR) of propylene homopolymer is 1.
00≧P≧0.015 log MFR+ 0. ．． 95
The first stage polymer of 5 is 70 to 95 weight of the total polymerized amount.
Then, 30 to 5 weight of the total polymerized amount of ethylene and propylene are polymerized in one or more steps, the ethylene content is 3 to 12 weight of the total polymerized amount, and the MFR is 4.
The above propylene-ethylene block copolymer Kl
Ethylene polymer 20 to 30 with l& of 0.94 f/cd or higher or Kumelt index of 10 to 50 F/10 minutes
1, and the average particle diameter surface-treated with a silane compound is 0.
A talc-containing polypropylene resin composition comprising 2 to 3 μm of Merck 10 to 30% by weight.

The propylene-ethylene block copolymer used in the present invention is a highly crystalline propylene-ethylene block copolymer (hereinafter referred to as a high-rigidity propylene-ethylene block copolymer) having a specific composition and monoproperty. be.

Ordinary propylene-ethylene block copolymers are manufactured using a polymerization method that involves two or more polymerization steps, each of which involves manufacturing a propylene homopolymer portion and an ethylene homopolymer portion, or an ethylene and propylene copolymer portion. Although it has better impact resistance than propylene homopolymer, it has the disadvantage that its heat distortion temperature is slightly lower than that of propylene homopolymer.

However, in the highly rigid propylene-ethylene block copolymer used in the present invention, the isotactic bent fraction (P) of the propylene homopolymer portion that accounts for 70 to 95% of the total weight and the MFR are 1.00≧P. ≧0.015
It is a highly rigid polypropylene with a log MFR + 0.955 relationship, and the ethylene content in the remaining ethylene-propylene copolymer is 3 to 3% of the total amount of the polymer.
12 weight.

Such a copolymer can be obtained, for example, by the method disclosed in JP-A-58-201816.

That is, a solid product obtained by reacting an organoaluminum compound or a reaction product of an organoaluminum compound and an electron donor with titanium tetrachloride is further reacted with an electron donor and an electron acceptor. Things (1)
) is combined with an organoaluminum compound and an aromatic carboxylic acid ester (...), and the molar ratio of the aromatic carboxylic acid ester and the solid product (1) is (II)/(1) = 0
．． In the presence of a catalyst with a concentration of 1 to 1 O10, the total polymerization amount was 70 to 10.
A highly rigid molded product with an ethylene content of 3 to 20 weight can be obtained by polymerizing 95 weight of propylene and then polymerizing 30 to 5 weight of the total polymerized amount of ethylene or ethylene and propylene at lR# or more. It can be obtained by a method for producing a propylene-ethylene block copolymer. The highly rigid propylene-ethylene block copolymer used in the present invention described in the same issue has various strengths and heat distortion temperatures compared to conventionally known propylene base polymers or propylene-ethylene block copolymers. . Further, the MFIt of the highly rigid propylene-ethylene block copolymer used is 4r/10 minutes or more, preferably 6F/10 minutes or more. If a material with an MFR of less than 4 is used, flow marks will be observed on the surface of the molded product, which is not preferable. In addition, the amount of the highly rigid propylene-ethylene block copolymer used is 40 to 70% by weight,
Preferably FiSO~65 wt.

If the blending amount is less than 40% by weight, the high temperature rigidity of the molded product will not be sufficiently improved, and if the blending amount exceeds 70% by weight, the performance of high temperature rigidity and impact resistance will decrease. This is not desirable as it will make things worse.

Next, the ethylene polymer used in the present invention has a density of 0.94.
C1/- or more, preferably 0.950 f/- or more, and the melt indef of the ethylene polymer is 1; R,
(MI, JIS K6760) is 10~5of/1
0 minutes, preferably 15 to 251/10 minutes.

Such ethylene polymers improve gloss, but are also effective in improving impact resistance.

Further, the density of the specific ethylene polymer is 0.9402/
If it is less than -, it is not preferable because it lowers high-temperature rigidity and reduces the effect of improving impact resistance. %,yt
If I is less than lof/10 minutes, compatibility with the propylene-ethylene block copolymer will be poor and flow marks will be observed on the surface of the molded product, which is undesirable. Furthermore, it is not preferable to use a material with an MI of more than 50 f710 minutes because it will reduce the impact resistance of the resulting molded product.

In addition, the amount of the specific ethylene polymer used is 20 to
30 weight, preferably 20 to 25 weight. If the blending amount is less than 20% by weight, the effect of improving impact resistance will not be sufficient, and if it exceeds 30% by weight, the high temperature rigidity will be significantly reduced and 70-marks will be observed on the surface of the molded product, so it is preferable. do not have.

Next, the talc used in the present invention has an average particle size of 0.
2 μ to 3 μ, chemically or physically by a silane compound! It has been processed on two sides. Particles with an average particle diameter of less than 0.2μ are not preferable because they do not improve high-temperature rigidity despite the amount of Merck added, and those with an average particle diameter of more than 3μ deteriorate impact resistance. Undesirable. Further, the use of talc whose back surface has been treated with a silane compound is effective in improving various mechanical strengths such as bending strength and tensile strength. In addition, silane compounds used for surface treatment of talc include γ-glycidoxyprobyltrimethoxysilane, glycidoxyethyltriethoxysilane, epoxyethyltriethoxysilane, and 1,2-epoxybutoxyprobyltriethoxysilane. Silane, r-aminobutyltriethoxysilane, disilane in r-aminobutyltriethane, aminoethyltriethoxysilane, β-(
Examples include 3,4-epoxycyclohexyl)ethyltrimethoxysilane and bis(β-human gastric xethyl)r-aminopropyltriethoxysilane.

A conventionally known method may be used to surface-treat the above-mentioned talc with the silane compound, and the amount of the silane compound used for the surface treatment is usually 0.1 to 100% of the talc.
5% by weight, preferably 0.1-3% by weight.

The amount of the surface-treated talc is 10 to 30% by weight, preferably 15 to 25% by weight.

If the blending amount is less than 10% by weight, it is difficult to say that the high temperature rigidity of the molded product is sufficient, and secondary deformation prevention property is not achieved sufficiently, which is not preferable.
If it exceeds 0 weight, the impact resistance of the resulting molded product will be lowered and flow marks will appear, which is not preferable.

The composition of the present invention may contain various additives that are normally added to polypqpyrene resin, such as antioxidants, antistatic agents, ultraviolet absorbers, copper inhibitors, pigments, etc., as necessary. can.

The composition of the present invention can be produced by mixing predetermined amounts of each component and thoroughly kneading the mixture. As a mixing device, a Hensel mixer (
A high-speed stirring device such as Super Mixer (trade name) or Super Mixer may be used, and as a mixing device, a Hanhari mixer, Roll, Conita +, single-screw or twin-screw extruder, etc. may be used. In addition, the crosstalk temperature is 180 tll: ~ 300
The temperature is preferably 210°C to 260°C.

The talc-containing polypropylene resin composition of the present invention can be used to produce various molded products by molding methods such as injection molding and extrusion molding, depending on the purpose.

〔effect〕

Molded products manufactured using the talc-containing polypropylene resin composition of the present invention maintain high-temperature rigidity as high as possible compared to molded products manufactured from conventional talc-containing polypropylene resin compositions, have low impact resistance, and have a glossy appearance. It has the characteristics of good resistance and no 70-mark, and can be suitably used for automobile interior parts, home appliance parts, 0μ equipment parts, and the like.

〔Example〕

Hereinafter, the present invention will be specifically explained with reference to Examples and Comparative Examples. In addition, in the Examples and Comparative Examples, the following method of evaluation was used.

1) Rigidity: Measurement of flexural modulus at 23°C and 80°C (J
ISK? 203) 2) Gloss: Measurement of translated version (based on JIS Z78411C) 3) Impact resistance: DuPont impact strength (Chisso method) DuPont impact tester [Toyo Seiki ■back], striking core V4 inch R1 Strike center cradle inner diameter 3/2 inch R1 load 0. I Kf~
Test piece 50X under the conditions of 2.5Kf, load drop height 1m
Using a 50x2n flat plate, after being conditioned at 23°C,
Place the test piece on the striking center stand and apply the striking center to the height IFFK.
Drop the load from the Tests were conducted one after another using a light load if the test piece broke, and a heavy load if it did not break, and the impact strength was calculated from the load at which approximately 50% of the test piece broke, and the impact resistance was evaluated.

4) Appearance of the molded product: Injection molding was performed using a rs zooBm injection molding machine [manufactured by Toshiba Machine ■] under the following molding conditions: Gold Fjl: 400 x 80 x 3M flat plate injection temperature: 230 ° C. Metal amount temperature: 30 ° C. The appearance of the obtained flat plate was visually evaluated, and when there were no silver streaks or 70-marks, the appearance of the molded product was judged to be good.

5) Overall judgment Flexural modulus and impact resistance at 80°C of the same composition,
Gloss and appearance were comprehensively evaluated and judged based on the following criteria.

O: Good High-rigidity propyle/-ethylene block copolymer 55% by weight MI13 with content 8.8% by weight, high density ethylene polymer 20% by weight with specific gravity 0.959 and 0 for Merck
．． Talc (1325% by weight) with an average particle size of 1.5 μm treated with 2 wt.
Stir and mix for 10 minutes using a Henchilum mixer (trade name).
A composition in the form of pellets was obtained by melt-kneading and extrusion using a single-screw extruder at a melt-kneading temperature of 1f250°C. Examples 2 to 5 will be described later using a high-rigidity propylene-ethylene block copolymer, a high-density ethylene polymer, and a surface-treated Merck (1) having the same physical properties as those used in Example 1 and having an average particle size of 1.5μ. They were blended at the blending ratios shown in Table 1, stirred and mixed in accordance with Example 1, and melt mixed and extruded to obtain a pellet-shaped composition.

Moreover, as Comparative Examples 1 to 6, Comparative Example 1 had an MFR of 6, P=0.92, and an ethylene content of 8.
In Comparative Examples 2 and 3, ethylene polymer and ethylene-propylene copolymer rubber ( Mooney viscosity M1+, =2
4. EP02P (trade name) manufactured by Japan Synthetic Rubber ■ was used, and in Comparative Example 5, silane-treated LUKU (2) with an average particle size of 5 μm was used, and in Comparative Example 6, MI 5, specific gravity 0.
Example I was prepared by blending each component in the proportions listed in Table 1 below, except that 952 high-density polyethylene (2) was used.
A pellet-shaped composition was obtained by stirring and mixing in accordance with K and melt cross-wire extrusion.

Predetermined test pieces were molded by injection molding using the pellets obtained in each of the above-mentioned cases and each comparative side, and the flexural modulus, gloss, impact resistance, and appearance were measured. The result is the first
! They are summarized in 2.

Claims (1)

[Claims] (1) The relationship between isotactic pentad fraction (P) and melt flow rate (MFR) of propylene homopolymer is 1.00≧P≧0.015 log MFB+0.9
55 is 70 to 95% by weight of the total polymerization amount, and then 30 to 5% by weight of the total polymerization amount of ethylene and propylene are polymerized in one or more steps, and the ethylene content is 70 to 95% by weight of the total polymerization amount. A propylene-ethylene block copolymer having an MFR of 4 or more and an ethylene polymer having a density of 0.94 g/cm^3 or more and a melt index of 10 to 50 g/10 min 20 ~30% by weight and average particle size 0.2-3 surface treated with silane compound
A talc-containing polypropylene resin composition containing 10 to 30% by weight of μ talc.