JPH04175354A - Reinforced polypropylene resin composition - Google Patents

Abstract

PURPOSE:To improve moldability, tensile strength of a molded item, etc., by compounding a specific modified PP, an amorphous ethylene-alpha-oleiefin copolymer, a hydrogenated styrene block copolymer, glass fibers, and a rigid mica. CONSTITUTION:100 pts.wt. crystalline ethylene-propylene block copolymer (a) contg. 2-20wt.% ethylene units is modified with 0.01-3 pts.wt. modifier comprising an org. silane compd. or an unsatd. acid to give a modified block copolymer (b). At least 20wt.% copolymer (b) is, if necessary, blended with copolymer (a), giving a modified PP. 45-75wt.% the modified PP, 1-10wt.% amorphous ethylene-alpha-olefin copolymer having an ethylene unit content of 30-80wt.% and Mooney viscosity (100 deg.C) of 10-150, 1-10wt.% hydrogenated styrene block copolymer, 2-12wt.% glass fibers having a mean fiber diameter of 4-15mmu and a mean fiber length of 2-5mm, 15-35wt.% rigid mica having a tensile strength of 30kg/mm<2> or higher, an average particle size of 50-250mmu, and an aspect ratio of 15-80, and, if necessary, a nucleating agent are compounded to give the title compsn.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a reinforced polypropylene resin composition particularly suitable for use in instrument panels, more specifically,
When molded into a molded product, the molded product has practically sufficient tensile strength, flexural modulus, flexural strength, hardness, falling ball impact strength, etc., has excellent other physical properties, and has excellent properties under high temperature conditions. The present invention relates to a reinforced polypropylene resin composition that is well-balanced in various respects, such as being able to reduce warpage while maintaining rigidity and impact resistance, and has good moldability.

[Intelligence B to be solved by the prior art and the invention] Various fillers, such as glass fibers, carbon fibers, whiskers, metal fibers, etc., are used to improve the mechanical strength, rigidity, heat deformation resistance, etc. of polypropylene molded products. It is conventional to add fibrous fillers such as mica, talc, kaolinite, plate-like fillers such as glass flakes, and granular fillers such as calcium carbonate, diatomaceous earth, alumina, and glass peas to polypropylene. It has already been used in a wide range of applications.

Among these various shapes of fillers, fibrous fillers have a particularly large reinforcing effect compared to other shapes of fillers, and in particular, polypropylene resin compositions reinforced with glass fibers are highly rigid and highly heat resistant. It is widely used in various fields as a material suitable for manufacturing products.

However, when producing particularly large molded products from glass fiber-reinforced polypropylene resin compositions, the resulting molded products do not have any problems in terms of rigidity and heat resistance, but the "warping" (deformation) of the molded products may occur. This is a problem when using glass fiber reinforced polypropylene resin compositions as molding materials for large molded products.

On the other hand, when polypropylene resin is used as a plate-shaped filler or a granular filler, the warping deformation becomes smaller, but
Compared to the case where a fibrous filler is used, the reinforcing effect on tensile strength, flexural modulus, flexural strength, isot impact strength and heat-resistant stiffness is significantly smaller. However, since molded products made of polypropylene resin compositions reinforced with plate-shaped fillers such as mica and talc exhibit good rigidity, attempts have been made to use both fibrous fillers and plate-shaped fillers. Ori,
For example, JP-A-52-36141, JP-A-54-
Publication No. 130647, Japanese Patent Application Publication No. 16049/1983,
JP-A-55-2] No. 438, JP-A-55-4571
No. 5, JP-A-58-206659, JP-A-Sho 5
It is disclosed in JP-A-9-226041, JP-A-60-23432, JP-A-61-98758, and the like.

However, even with the inventions disclosed in these publications, a molded article that satisfactorily prevents warpage and twisting has not been obtained.

Therefore, an object of the present invention is to ensure that, when processed into a molded product, the molded product has practically sufficient tensile strength, flexural modulus,
It has good bending strength, hardness, ball impact strength, and other physical properties, and is well-balanced in many aspects, such as being able to maintain the rigidity and impact resistance of the molded product while minimizing warping deformation. An object of the present invention is to provide a reinforced polypropylene resin composition with good processability.

(Means for Solving the Problem) As a result of intensive efforts, the present inventors have found that by blending specific amounts of mica and a specific elastomer having a specific shape into glass fiber reinforced polypropylene resin,
It has been found that a reinforced polypropylene resin composition that can achieve the above object can be obtained.

The present invention was made based on the above findings, and consists of (a) modified polypropylene modified with an organic silane compound or unsaturated acid, or modified polypropylene containing unmodified polypropylene ---45 to 75% by weight (% by weight) (b) Amorphous ethylene/α-olefin copolymer---1 to 1
0% by weight (C) Styrenic hydrogenated bronc copolymer------
1 to 10% by weight fd) Glass fiber with an average fiber diameter of 4 to 15 mμ---
--2 to 12% by weight and (e) tensile strength of 30 kg/mm2 or more and average particle size of 50
~250mμ, hard mica with aspect ratio 15-80
--15 to 35% by weight, and the total amount of the component (b) and the component (c) is 2 to 14% by weight. .

The reinforced polypropylene resin composition of the present invention will be explained in detail below.

In the present invention, as the polypropylene constituting the component (a), a crystalline ethylene/propylene block copolymer having an ethylene content of 2 to 20% by weight, preferably 3 to 15% by weight is used. If it exceeds 20% by weight, the rigidity may be insufficient, and if it is less than 2% by weight, the impact resistance may be insufficient.

The modified polypropylene, which is the component (a), is modified with an organic silane compound or an unsaturated acid, and the polypropylene and the organic silane compound or an unsaturated acid are melt mixed in the presence of a peroxide. obtained by doing.

In addition, the modified polypropylene containing unmodified polypropylene, which is the component (a), refers to the combination of the above polypropylene and the above modified polypropylene, and (a)
It is preferable that the modified polypropylene component is used in an amount of 20% by weight or more in the composition.

If the amount of modified polypropylene is less than 20% by weight,
There is a risk that both rigidity and impact strength will be insufficient.

The organosilane compound used to prepare the modified polypropylene is an organosilane compound containing an ethylenically unsaturated bond such as a vinyl group, an allyl group, or a methacryloxy group. Examples thereof include vinyltrimethoquinonerane, Examples include vinyltrinidoxinlan, vinyltris(β-methoxoethoxy)solane, and T-methacryloxobrobyltrimethoxysilane.

Further, an unsaturated acid may be used instead of the organic silane compound. Examples of unsaturated acids include unsaturated carboxylic acids or their anhydrides, such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, ntraconic acid, maleic anhydride,
Itaconic anhydride or the like can be used.

In the present invention, the amount of the organic silane compound or unsaturated acid is preferably in the range of 0.01 to 3 parts by weight, and 0.3 parts by weight based on 100 parts by weight of the crystalline ethylene/propylene block copolymer. More preferably, the amount is in the range of 1 part by weight. If it exceeds 3 parts by weight, the molded appearance tends to be poor, and if it is less than 0.01 part by weight, it is difficult to improve the physical properties.

The organic peroxide used in the preparation of the modified polypropylene has a decomposition temperature of 200°C to obtain a half-life of 1 minute.
The following are preferred. Examples of such organic peroxides include t-butyl baroquinhendoate, t-
butyl peroxymaleic acid, t-butyl peroxylaurate, cyclohexanone peroxide,
2.5-dimethyl-2,5-di(benzoylperoxy)hexane, t-butylperoxyacetate, t-butylperoxybenzoate, methyl ethyl ketone peroxide, dicumyl peroxide, 2,5-dimethyl-2,5 -di(t-butylperoxy)hexane, t
-butylcumyl peroxide, di-t-butyl peroxide, and the like.

The amount of organic peroxide blended is preferably in the range of 0.05 to 1 part by weight per 100 parts by weight of the crystalline ethylene-propylene block copolymer.

To obtain modified polypropylene by dissolving and kneading polypropylene and an organic silane compound or unsaturated acid,
Various known methods can be used. The above-mentioned organic silane compound or unsaturated acid and the above-mentioned organic peroxide are added to polypropylene, and after stirring and mixing using a Henschel mixer, etc., the mixture is preferably mixed using an extruder at a melt mixing temperature of 180 to 250°C. A method of melt-kneading and extruding for about 1 to 20 minutes is simple and suitable.

The amount of polypropylene used as component (a) is 45 to
If the content is less than 45% by weight, moldability will deteriorate, and if it exceeds 75% by weight, the balance between rigidity and impact resistance will deteriorate.

Amorphous ethylene α- which is the component (b) of the present invention
As an olefin copolymer, the ethylene content is 30 to 8.
Mooney viscosity ML, at 0% by weight. , (100°C) is preferably 10 to 150.

Examples of such copolymers include ethylene propylene rubber, ethylene butene rubber, ethylene propylene butene rubber, ethylene propylene diene rubber, and ethylene butene diene rubber. The amount used is 1 to 10% by weight, preferably 1 to 8% by weight.

As the styrenic hydrogenated bronc copolymer which is the component (C) of the present invention, 5EBS and 5EPS are preferably used, and these are known as Kraton C (Shell Chemical), Tuftic (Asahi Kasei), and Cefton (Kuraray). , is commercially available. The amount used is 1 to 10% by weight, preferably 1 to 8% by weight.

The total usage amount of the component (b) and the component (C) in the present invention is 2 to 14% by weight, preferably 2 to 10jl.
The amount is %. If it is less than 2% by weight, the warpage will be excessive and 1
If it exceeds 4% by weight, rigidity will be insufficient.

The glass fiber, which is the component (d) in the present invention, is usually produced for resin reinforcement and is commercially available glass chopped strand or glass roving, and has an average fiber diameter of 4 to 15 mμ and an average fiber length. is 2~],
A 5mm one is used. In particular, from the viewpoint of physical properties such as rigidity and impact resistance, those having an average fiber diameter of 6 to 13 mμ and an average fiber length of 2 to 5 m are preferred. If the fiber diameter is less than 4 mμ, it will break during kneading and the rigidity will decrease, and if it exceeds 15 mIJ, the glass fiber will stand out in the molded product. If the fiber length is less than 2 m++, the rigidity will be insufficient, and if it exceeds 5 m, the dispersibility will decrease and the appearance of the molded product will deteriorate.

In addition, the glass fibers include aminosolane compounds,
Those surface-treated with a coupling agent such as an epoxysilane compound, a vinylsilane compound, or a methacrylosilane compound are preferably used.

In addition, the average fiber length of the glass fibers in the final molded product is preferably 0.5 rim or more from the viewpoint of physical properties, and for this purpose, in the production of glass fiber reinforced polypropylene, in addition to the usual raw material supply port, it is necessary to Using an extruder equipped with a raw material supply port in a part of the cylinder, the components (a), (b), (C), and (e) are supplied through the usual raw material supply port, and the raw material supply port in a part of the cylinder. More preferable is a method in which the components (d) are individually supplied and melt-kneaded. The amount of glass fiber added is 2 to 12% by weight, preferably 3 to 10% by weight. If it is less than 2% by weight, the rigidity will be insufficient, and if it exceeds 12% by weight, the warpage will be excessive.

The hard mica which is the component (e) in the present invention has a tensile strength of 30 kg/111111'' or more and an average particle size of 50 to 250 mu.
If the average particle diameter is less than 50 mμ, the rigidity of the molded product will be insufficient; if the average particle diameter is less than 50 mμ, the rigidity will be insufficient, and the warpage will be excessive; and if it exceeds 250 mμ, the impact resistance will be insufficient.

Furthermore, the mica used in the composition of the present invention is not particularly limited as long as it has the above-mentioned tensile strength, average particle size, and aspect ratio, and can be selected from a wide range of biotite, muscovite, phlogopite, etc. can.

Furthermore, the mica used in the present invention may be unsurface-treated or may be surface-treated with various surface-treating agents.

Mica is used in an amount of 15 to 35% by weight; if mica is less than 15% by weight, rigidity is insufficient, and if it exceeds 35% by weight, impact resistance is insufficient.

Furthermore, in order to shorten the molding cycle when injection molding the composition of the present invention, 0.1 to 1.5 parts, preferably 0.2 to 1.5 parts of a nucleating agent is added to 100 parts of the composition of the present invention. A nucleating agent is preferably blended in an amount of 1.0 part, and usually deforms the molded product, so it is not used when the purpose is to improve deformation. Nucleating agents increase rigidity but reduce impact resistance, so nucleating agents are used for materials with low rigidity. By incorporating the agent, we obtained the completely unexpected result that a composition with high rigidity and a short molding cycle could be obtained without increasing the deformation of the molded article or reducing the impact resistance.

Further, various additives such as antioxidants, ultraviolet absorbers, antistatic agents, heat resistant agents, nucleating agents, pigments, etc. can be used in combination with the composition of the present invention.

[Examples] Hereinafter, the present invention will be specifically explained with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

As a test method for evaluating the effects of the present invention, physical properties were evaluated according to the following method.

Real J12 length this l''■1 power U1 type 1. Melt flow rate (VFR) JIS K
7210 (230°C)2, Flexural strength (FS) Based on JIS K7203 (23°C)3, Flexural modulus (FM) Based on JIS K7203 (23°C)4, Izod impact strength; Notched (Izod) ) JIS K7
110 (23°C) 5, heat distortion temperature (HDT) JIS K7207 (load 18.5 kg/ctfl
) Compliant with 6, Warp deformation thickness 2s, vertical direction 360+n+++, horizontal direction 160mm
The test piece was made by injection molding a rectangular flat plate with one gate (side gate) located 75 pixels inside from the end in the vertical direction.
After leaving it for 48 hours under conditions of 50% humidity, place the test piece on a surface plate and measure the distance (height) between both ends of the test piece and the surface plate.
were measured and the average value of the distances was calculated.

7. Aspect ratio Calculated from the average particle diameter and average thickness of mica.

- Average particle diameter of mica The particle size structure was measured using a JIS standard sieve with a sieve using ALP TNE's Air Jet Sieve 200LS model, and the average particle diameter was determined from the diameter on log probability paper.

・Average thickness of mica The average thickness was measured from the area of the monomolecular film using the Kyoto University method.

・Average aspect ratio It was calculated using the following formula.

8. When injection molding an instrument panel with a molding cycle length of 1400 wm, height 300 am, width 450 mm, and weight 3.5 kg (molding machine: 2500), Toshiba Machine IS-2500DN, molding temperature 230''C). The shortest molding cycle.

9. Heat deformation resistance The surface temperature of the instrument panel is 115±3°C1
The instrument panel was irradiated with an infrared lamp (Tabai Espec Model T-1O5) for 4 hours so that the atmosphere was 80±2°C, and then left at room temperature.

Then, a judgment was made based on whether the amount of deformation (in the vertical direction) of the front end (garnish) of the instrument panel was greater or less than the reference value (3■).

G: Deformation amount is 3m or less NG, Deformation amount is 3mm or more 10, Impact resistance Based on FMVSS201, ECE No. 21, 24km of Radform (165φ, 6.8kg) to aluminum
The instrument panel is struck at a speed of /h (Test device: Ito Seiki Model Al-150P). The criteria for this impact test is that the generated acceleration is 3 m5e.
Judgment was made based on whether or not the weight did not exceed 80 g continuously for more than c and whether sharp edges did not occur on the hitting surface.

G; Satisfied NG; Unsatisfactory Example I Anhydrous Itacone is added to 100 parts by weight of a crystalline ethylene-propylene block copolymer having a VFR of Ig/10 min and an ethylene content of 7.6% by weight! 0.3 parts by weight, 0.15 parts by weight of t-butylperoxybenzoate and 2.6-di-t
-Butyl-4-methylphenol 0.1 part by weight, pentaerythrityl tetrakis C3-(3,5-di-t-butyl-4-hydroxyphenylpropione)) 0.1
The weight parts were mixed in a tumbler, and 20 parts were mixed in a screw extruder.
The mixture was melt-kneaded at 0° C. for 2 minutes to obtain MFRI graft-modified with itaconic anhydride and modified polypropylene (hereinafter abbreviated as modified PP-1) of 2 g/10 min.

This modified PP-1 is 65% by weight, and the enalene content is 75%.
3% by weight of ethylene-propylene copolymer (hereinafter abbreviated as EPR) with a Mooney viscosity ML of 70 (100°C), Kraton G1650 (shell chemical type, hereinafter referred to as a styrene-based hydrogenated block copolymer) , 5t-1
(abbreviated as) 2% by weight and tensile strength of 34kg/m”
, mica with an average particle diameter of 140 mμ and an average aspect ratio of 64 (■ manufactured by Revco, hereinafter abbreviated as mica-1) 25
% by weight in a tumbler, and using a twin-screw extruder having two raw material supply ports, the above mixture was supplied from a normal raw material supply port to form an aminosilane 0.5 mm with a diameter of 10 mμ and a length of 3 cm. 3% by weight of chopped strand glass fiber (manufactured by Nippon Electric Glass, hereinafter abbreviated as CF) was metered and fed from another raw material supply port provided in a part of the cylinder. , temperature 230-240°C
The mixture was melt-kneaded, extruded, and pelletized. The obtained pellets were injection molded to prepare test pieces, which were subjected to various evaluation tests. The evaluation test results are shown in Table 1.

Example 2 59% by weight of modified pp-i, 1% by weight of EPR, 5t-
Example 1 was carried out in the same manner as in Example 1, except that the blending ratios were changed to 7% by weight of 1 and 8% by weight of CF. The evaluation test results are shown in Table 1.

Example 3 The blending ratio of modified PP-1 was changed to 30@ii%, and the MFR
was added for 9 g/10 minutes, 30% by weight of a crystalline ethylene/propylene block copolymer (hereinafter abbreviated as unmodified PP) with an ethylene content of 7.5% by weight, 3% by weight of 5t-1, and 3% by weight of OF. The blending ratio was changed to 6% by weight of Mica-1 and 28% by weight of Mica-1, and all components 1 including 3% by weight of EPR.
Example 1 was carried out in the same manner as in Example 1, except that 044 parts by weight of a nucleating agent (p-t-butyl aluminum benzoate) was added to 00M parts. The evaluation test results are shown in Table 1.

Example 4 The blending ratio of unmodified PP was changed to 32% by weight, and the styrene-based hydrogenated block copolymer was changed to Septon 2003 (manufactured by Kuraray ■, hereinafter abbreviated as 5t-2), and 3% by weight was blended. Example 3 was carried out in the same manner as in Example 3, except that the mixing ratios were changed to 2% by weight for EPR and 5% by weight for CF. The evaluation test results are shown in Table 1.

Example 5 25% by weight of modified pp-i, 47% by weight of unmodified PP,
1% by weight of EPR, 1% by weight of 5t-2, 4% by weight of GF, 12% by weight of mica-1, and a tensile strength of 39 kg/
m'', average particle diameter 60 mμ, average aspect ratio 37 mica (made by Repco, hereinafter abbreviated as mica-2) was
For 100 parts by weight of all ingredients blended at a blending ratio of % by weight,
The same procedure as in Example 4 was carried out except that the nucleating agent was changed to 0.8 parts by weight and added. The evaluation test results are shown in Table 1.

Example 6 Example 1 was performed using 0.5 parts by weight of γ-methacryloxypropyltrimethoxysilane and 0.25 parts by weight of t-butylperoxyhenzoate in place of itaconic anhydride in Example 1. A modified polypropylene graft-modified with silane and having an MFR of 15 g/10 minutes (hereinafter abbreviated as modified PP-2) was obtained in the same manner as above. Next, 38% by weight of modified PP-2 was used instead of modified PP-1 in Example 5, 14% by weight of unmodified PP, 7% by weight of EPR, 2% by weight of 5t-1 instead of 5t-2, and 6% of CF. Weight%, mica-1
10% by weight of Mica-2, 23% by weight of Mica-2, and 0.0% of the nucleating agent.
The same procedure as in Example 5 was carried out except that 5 parts of fU was used.

The evaluation test results are shown in Table 1.

Comparative Example I The same procedure as in Example 1 was carried out except that the blending ratio of CF was 15% by weight and the blending ratio of Mica-1 was 15% by weight.

The evaluation test results are shown in Table 2.

Comparative Example 2 The same procedure as Example 1 was carried out except that modified PP-1 was 60% by weight, 5t-1 was 10% by weight, and EPR was not added. The evaluation test results are shown in Table 2.

Comparative Example 3.4 In Comparative Example 3, the blending ratio of mica-1 was 30% by weight, CF
Comparative Example 4 was carried out in the same manner as in Example 1 except that no additive was added, and in Comparative Example 4, the blending ratio of modified PP-1 was 50% by weight, and the blending ratio of mica-1 was 40% by weight. Table 2 shows the evaluation test results.
Shown below.

Comparative Example 5.6 In Comparative Example 5, the blending ratio of modified PP-1 was 35% by weight, and E
PR and 5t-2 were not added, and in Comparative Example 6, mica (manufactured by Revco, hereinafter referred to as Mica-3) with a tensile strength of 18 kg/Im'', an average particle diameter of 160 mμ, and an average aspect ratio of 65 was used instead of Mica-1. The evaluation test results are shown in Table 2.

Comparative Example 7 The same procedure as in Example 1 was conducted except that 5% by weight of the EPR of Example 1 was used and 5t-1 was not used. The evaluation test results are shown in Table 2.

[Effects of the Invention] When the reinforced polypropylene resin composition of the present invention is molded into a molded product, the molded product has practically sufficient tensile strength, flexural modulus, flexural strength, hardness, It is a well-balanced composition with good ball impact strength and other excellent physical properties.

In particular, when the reinforced polypropylene composition of the present invention is molded into a large-sized molded article, the molded article is compared to molded articles obtained from conventionally known glass fiber-reinforced polypropylene compositions. , the "warpage" is significantly improved and reduced to the extent that it hardly poses a problem in practice.

Therefore, the reinforced polypropylene composition of the present invention can achieve "
This is a solution to the problem of reducing "warpage."

For example, the core of the instrument panel of an automobile part (
It is particularly useful as a reinforced polypropylene resin composition with good carving processability, which is suitable for manufacturing molded products used in applications that require large molded products that are difficult to deform, such as core materials. .

INDUSTRIAL APPLICABILITY The reinforced polypropylene composition according to the present invention can be used to obtain molded products that have high rigidity, high heat resistance, and high impact resistance under high-temperature conditions, and have extremely low warping deformation, and are particularly suitable for use in cores of automobile instrument panels. This composition is suitable as a material.

Claims (2)

[Claims] (1) (a) Modified polypropylene modified with an organic silane compound or unsaturated acid, or modified polypropylene containing unmodified polypropylene...45 to 75% by weight (% by weight is a percentage of the composition, the same applies hereinafter) ) (b) Amorphous ethylene/α-olefin copolymer 1~
10% by weight (c) 1 to 10% by weight of styrenic hydrogenated block copolymer (d) 2 to 12% by weight of glass fibers with an average fiber diameter of 4 to 15 mμ, and (e) Tensile strength of 30 kg/mm^2 or more Average particle size 5
0 to 250 mμ and an aspect ratio of 15 to 80 hard mica...15 to 35% by weight, and the total amount of the component (b) and the component (c) is 2 to 14% by weight. A reinforced polypropylene resin composition. (2) A claim characterized in that 0.1 to 1.5 parts of the nucleating agent is used with respect to 100 parts (parts by weight, the same applies hereinafter) of the components (a) to (e) in total. 1) The reinforced polypropylene resin composition described above.