JPH08104774A - Glass fiber reinforced resin molding - Google Patents

Abstract

PURPOSE: To provide a glass fiber reinforced thermoplastic resin molding which retains the length of glass fibers even after color matching and which has high mechanical strength and heat resistance. CONSTITUTION: This molding consists of 20-94.99wt.% thermoplastic resin, 0.01-10wt.% zinc sulfide and 5-70wt.% glass fibers having an average diameter of 3-20μm, with the average length of the fibers therein being 1-10mm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass fiber reinforced resin molded product which is preferably used as a material for automobile parts, home electric appliance parts, OA equipment parts and the like.

[0002]

Molded articles of glass fiber reinforced thermoplastic resins such as glass fiber reinforced polypropylene are used as important materials in various industrial fields because of their high mechanical strength. In this case, it is important to disperse the glass fibers in the molded product as long and uniformly as possible in order to bring out the performance of the glass fiber reinforced resin molded product.

Further, in the case of producing a glass fiber reinforced resin molded product, it is often necessary to adjust the color of the glass fiber reinforced resin in various applications. Titanium oxide, which is a typical white pigment, is used for the colored glass fiber reinforced resin composition based on white. However, in this case, there is a drawback that the mechanical strength and heat resistance of the molded product are lowered. Therefore, a resin composition using a zinc sulfide-based pigment instead of titanium oxide has been proposed. For example, a resin composition in which a polyethylene terephthalate resin, glass fiber and a zinc sulfide pigment are blended in a predetermined ratio (Japanese Patent Laid-Open No. Sho 60).
No. 233150) is disclosed.

[0004]

However, what is shown in this is a resin composition in which the respective components are uniformly kneaded, and when this is further molded into a molded article, it is confirmed from the examples. As is also clear, the length of the glass fiber in the molded product compared to the length of the raw glass fiber (6 mm) is
Extremely short at 0.42 mm or less, instead of titanium oxide,
Even if zinc sulfide is used, a molded product having an average fiber length of 1 mm or more has not been obtained. Therefore, the molded product is not always sufficient in strength and heat resistance, and there is a problem that the performance of glass fiber is not fully utilized.

The present invention has been made in view of the above problems, and has high mechanical strength such as tensile strength, bending strength and impact strength even when toning is performed, and has high heat resistance such as high temperature bending strength and heat distortion temperature. It is an object to provide a high glass fiber reinforced resin molded product.

[0006]

In order to achieve the above object, according to the present invention, (A) thermoplastic resin 20-94.
99% by weight, (B) 0.01 to 10% by weight of zinc sulfide, and (C) 5 to 5 μm of glass fibers having an average fiber diameter of 3 to 20 μm.
The average fiber length in a molded product composed of 70% by weight is 1 to 10 m.
There is provided a glass fiber reinforced resin molded product characterized by having m.

Further, (A) thermoplastic resin 20 to 94.9
9% by weight, (B) zinc sulfide 0.01 to 10% by weight,
(C) Glass fibers 5 to 70 having an average fiber diameter of 3 to 20 μm
% Based on 100% by weight and (D) 100 parts by weight of zinc sulfide.
Provided is a glass fiber reinforced resin molded product, characterized in that an average fiber length in the molded product composed of 01 to 10 parts by weight of a cobalt salt is 1 to 10 mm.

The present invention will be described in more detail below.
First, each component will be described. There are no particular restrictions on the type of the thermoplastic resin as the component (A), and examples thereof include polyolefin, polyamide, styrene maleic anhydride copolymer resin (SMA), acrylonitrile-styrene copolymer resin (AS), and acrylonitrile-butadiene-. Styrene copolymer resin (ABS), acrylonitrile-
Any of styrene resins such as ethylene-styrene copolymer resin (AES), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycarbonate, polyphenylene sulfide (PPS), polyacetal, polymethylpentene, polyphenylene oxide (PPO), etc. It can also be used.
Among these, polyolefin or SMA, AS, A
Styrene resins such as BS and AES, especially polypropylene homopolymer and crystalline ethylene-propylene copolymer are preferred.

As the polypropylene homopolymer and crystalline ethylene-propylene copolymer, more specifically,
Isotactic propylene homopolymer having crystallinity, a copolymerization part consisting of an ethylene propylene random copolymer having a low ethylene unit content or a homopolymerization part consisting of a propylene homopolymer and the content of ethylene units are relatively small. A block copolymer of substantially crystalline propylene and ethylene, which is commercially available as a so-called propylene block copolymer, or a block copolymer thereof, which is composed of a copolymerization portion composed of a large number of ethylene propylene random copolymers. Each homopolymerization part or copolymerization part in
In addition, butene-1,2-methylpentene-1 and other α-
Preferable examples include propylene-ethylene-α-olefin copolymers which are substantially crystalline and which are obtained by copolymerizing olefins.

The content (composition ratio) of the component (A) is 20 to 94.99% by weight, preferably 50 to 90% by weight, based on the whole. When it is less than 20% by weight, the moldability is deteriorated and the appearance of the molded product is deteriorated. If it exceeds 94.99% by weight, the tensile strength, bending strength, rigidity and heat resistance will decrease.

Component (B) The component (B), zinc sulfide, is added as a pigment, which makes it possible to keep the fiber length of the glass fiber in the molded product long. On the other hand, when titanium oxide is used as the pigment instead of zinc sulfide, it is difficult to hold the glass fiber in the molded product for a long time, and the tensile strength, bending strength, rigidity and heat resistance of the molded product are reduced. The properties of zinc sulfide are not limited, but the average particle size is 0.1 to 1 μm, particularly 0.2 to 0.8 μm, and the purity is 9
It is preferably 0% or more, particularly 95% or more. If the average particle size is less than 0.1 μm, the pigment dispersion may be poor, and if it exceeds 1 μm, sufficient toning may not be achieved. Further, if the purity is less than 90%, heat resistance and weather resistance may deteriorate.

The content (composition ratio) of zinc sulfide is 0.01 to 10% by weight, preferably 0.03 to 10% by weight based on the total amount of zinc sulfide.
It is 5% by weight. If it is less than 0.01% by weight, coloring (toning) becomes insufficient. If it exceeds 10% by weight, the molded product becomes heavy and the physical properties are deteriorated. Also, if it is added in excess of 10% by weight, there is no merit in toning, and it is not economical.

Component (C) As the component (C), glass fiber having an average fiber diameter of 3 to 20 μm, preferably 6 to 15 μm is used. If the average fiber diameter is less than 3 μm, the fibers are easily broken during molding, and the impact strength of the molded product is insufficient. If it exceeds 20 μm, the appearance of the molded product is deteriorated and the strength of the molded product is insufficient. Also,
The content (composition ratio) of the glass fiber is 5 to 70% by weight, preferably 10 to 50% by weight of the whole. When it is less than 5% by weight, the effect of improving various physical properties such as tensile strength, bending strength, rigidity and heat resistance is small, and when it exceeds 70% by weight, the moldability is deteriorated and the appearance of the molded product is deteriorated.

Component (D) The type of the cobalt salt used as the component (D), if necessary, is not particularly limited, and examples thereof include cobalt naphthenate, basic cobalt carbonate, cobalt chloride, and cobalt stearate. However, cobalt naphthenate can be preferably used. Cobalt salt content (composition ratio)
Is 0.01 to 100 parts by weight of zinc sulfide of (B).
10 parts by weight, preferably 0.05 to 5 parts by weight.
If it is less than 0.01 part by weight, the effect of improving the durability performance such as weather resistance will be small, and if it exceeds 10 parts by weight, the hue of the molded article will be deteriorated and the heat resistance and rigidity will be deteriorated. In addition,
In addition to the above components (A) to (D), the molded article of the present invention comprises
Additives such as an antioxidant, a weather resistance agent, a release agent, a dispersant, and a pigment may be appropriately contained according to the purpose.

The method of producing the molded article of the present invention is not particularly limited, but for example, thermoplastic resin pellets (P1) containing glass fibers are prepared. At that time, a method other than melt-kneading is used. That is, a fiber bundle of glass fibers (C) having an average fiber diameter of 3 to 20 μm is continuously passed through a melt of a thermoplastic resin, and the fiber bundle is impregnated with the melt to form a strand, Cut it after cooling. Specifically, as described in Japanese Patent Application No. 1-332269, when the fiber bundle is impregnated with a molten resin, the fiber bundle has at least one predetermined side with respect to a straight line passing through the center of the rod. The rod may be wound around the rod while being inclined at an angle. In this case, preferably, the fiber bundle is wound around the rod with at least one side having an inclination angle of 10 degrees or more with respect to a straight line passing through the center of the rod. In addition, the fiber bundle is brought into contact with a plurality of rods so that the fiber bundle forms a corrugation if necessary.

More specifically, first, a fiber bundle (glass roving) is continuously passed through a molten thermoplastic resin to impregnate the fiber bundle with the molten resin. At this time, the fiber bundle is repeatedly bent so as to form a corrugated shape so as to pass through the thermoplastic resin. In this way, the fiber bundle is sufficiently opened, and the fiber bundle can be sufficiently impregnated with the thermoplastic resin. Next, the fiber bundle (strand) impregnated with the thermoplastic resin is cooled, and then finely cut by a pelletizer to be pelletized. That is, the length of the glass fiber is approximately the length of the pellet. By adjusting the cutting length of this pellet, the average length of the glass fiber is adjusted to 30 mm or less.

On the other hand, prior to the molding of the molded article, the thermoplastic resin and zinc sulfide are melt-kneaded to form pellets (P2). In this case, the thermoplastic resin is the pellet (P
It may be the same as or different from the thermoplastic resin used in the production of 1). In addition, it is preferable to mix the cobalt salt (D) with the pellet (P2) from the viewpoint of improving the long-term performance of the molded product.

In the present invention, the above pellet (P1)
If necessary, a thermoplastic resin is added to (P2) to adjust the amount of resin in the resin composition, and the mixture is melt-kneaded to directly form a molded product. Examples of this melt-kneading molding method include molding methods such as injection molding and extrusion molding.
In the above-mentioned molding example, using a reinforced resin pellet obtained by compounding glass fiber and a thermoplastic resin without using a melt-kneading step, a direct molded article is formed by using pellets obtained by uniformly kneading zinc sulfide and a thermoplastic resin. Since it is molded, there is little contact between glass fibers and direct contact between zinc sulfide and glass fibers, glass fibers are wrapped by impregnation of thermoplastic resin, and melting and kneading of glass fibers and resin once Therefore, the average fiber length of the glass fibers in the molded product can be kept as long as 1 to 10 mm, and the dispersibility is excellent, so that the molded product is remarkably excellent in strength, rigidity and heat resistance. It has become possible to obtain. That is, in the case of a conventional glass fiber reinforced resin molded product, usually a resin and glass fiber are melt-kneaded by an extruder to produce a composition (pellet), and the molded product is molded using this pellet. , The obtained molded product was ruptured due to direct contact between glass fiber and zinc sulfide and double melting and kneading, and the average fiber length of the glass fiber in the molded product was short, resulting in strength and heat resistance. However, the effect of improving rigidity was insufficient. Therefore, a molded product in which the glass fiber in the molded product is kept long and the dispersibility is improved is not known.

[0019]

Next, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. Examples 1 to 3 and Comparative Examples 1 to 3 According to the method described in Japanese Patent Application No. 1-232269, 40% by weight of polypropylene having MI of 60 g / 10 min.
And a glass fiber having a fiber diameter of 10 μm and 60% by weight of glass fiber were continuously formed into strands, which were then cut to a pellet length of 9 mm and used as a masterbatch MB-1. Also, MI is 2
Pellets PP1 to PP6 were obtained by dry blending 0 g / 10 min of polypropylene with titanium oxide and zinc sulfide in the proportions shown in Table 1 below, and then kneading with a biaxial kneader.

[0020]

[Table 1]

Next, 75% by weight of the above PP-1 (Example 1), PP-2 (Example 2), PP-3 (Example 3),
PP-4 (Comparative Example 1), PP-5 (Comparative Example 2) or PP
-6 (Comparative Example 3) and 25% by weight of the above masterbatch M
After dry blending with B-1 respectively, test pieces of Examples 1 to 3 and Comparative Examples 1 to 3 were prepared using an injection molding machine. Table 2 shows the ratio of each component in these test pieces.
The obtained test piece was conditioned for 48 hours, and then its physical properties were measured. The results are shown in Table 3. In addition, each physical property of Table 3 was measured by the following method.

Hue: It was visually observed. Tensile strength: Measured according to JIS K7113. Elongation: Measured according to JIS K7113. Bending strength: Measured according to JIS K7203. Flexural modulus: Measured according to JIS K7203. Bending strength at 120 ° C .: Measured according to JIS K7203. IZOD impact strength: Measured according to JIS K7110. HDT (high load): Measured in accordance with JIS K7207.

[0023]

[Table 2]

[0024]

[Table 3]

Example 4 80% by weight of a crystalline ethylene-propylene copolymer having an MI of 30 g / 10 min and 20% by weight of zinc sulfide were dry blended and then kneaded by a twin-screw extruder to prepare pellets. This was used as a pigment masterbatch MB-2. Masterbatch M of 45% by weight and 50% by weight of crystalline ethylene-propylene copolymer having MI of 30 g / 10 min
After dry blending B-1 and 5% by weight of masterbatch MB-2, injection molding was performed in the same manner as in Example 1 to prepare a test piece, and the physical property test was performed in the same manner. The results are shown in Table 4.

Example 5 80% by weight of a crystalline ethylene-propylene copolymer having an MI of 30 g / 10 minutes and 20% by weight of zinc sulfide, and further 2 parts by weight of cobalt naphthenate was added to 100 parts by weight of zinc sulfide. Then, after dry-blending, the mixture was kneaded with a twin-screw extruder to prepare pellets, which were used as a pigment master batch MB-3. MI of 30 g / 10 minutes crystalline ethylene-propylene copolymer 45% by weight, 50% by weight
After the masterbatch MB-1 and the masterbatch MB-3 of 5% by weight were dry blended, injection molding was performed in the same manner as in Example 1 to prepare a test piece, and the physical property test was performed in the same manner. The results are shown in Table 4.

Comparative Example 4 80% by weight of a crystalline ethylene-propylene copolymer having an MI of 30 g / 10 min and 20% by weight of titanium oxide were dry-blended and then kneaded with a twin-screw extruder to prepare pellets. This was used as pigment masterbatch MB-4. Masterbatch M of 45% by weight and 50% by weight of crystalline ethylene-propylene copolymer having MI of 30 g / 10 min
After dry blending B-1 and 5% by weight of masterbatch MB-4, injection molding was carried out in the same manner as in Example 1 to prepare a test piece, and the same physical property test was carried out. The results are shown in Table 4. Table 4 shows the proportion of each component in Examples 4 and 5 and Comparative Example 4 described above. In addition, Example 4 and Example 5
For, the weather resistance was examined by the following method. The results are shown in Table 6. Weather resistance evaluation method: A 63 ° C. SWOM was used to measure the color difference (ΔE) of the sample surface after exposure for 250 hours or 500 hours in accordance with JIS K7105.

[0028]

[Table 4]

[0029]

[Table 5]

[0030]

[Table 6]

[0031]

As described above, according to the present invention,
It is possible to provide a glass fiber-reinforced resin molded article having high mechanical strength and high heat resistance, which is obtained by keeping the fiber length of glass fiber long even when toning is performed.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location C08L 101/00

Claims (2)

[Claims] 1. A thermoplastic resin (A) of 20 to 94.99% by weight, (B) zinc sulfide of 0.01 to 10% by weight, and (C) an average fiber diameter of 3 to 20 μm of glass fibers 5 to 70.
A glass fiber reinforced resin molded product, characterized in that the average fiber length in the molded product composed of wt% is 1 to 10 mm. 2. (A) 20 to 94.99% by weight of a thermoplastic resin, (B) 0.01 to 10% by weight of zinc sulfide, (C) 5 to 70% by weight of glass fiber having an average fiber diameter of 3 to 20 μm. And (D) 0.01 to 1 with respect to 100 parts by weight of zinc sulfide
A glass fiber reinforced resin molded product, characterized in that the average fiber length in the molded product consisting of 0 parts by weight of cobalt salt is 1 to 10 mm.