JPH10219027A - Powdery glass fiber-reinforced resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition capable of reducing warpage and twist of shaped articles and giving shaped articles having little reduction in mechanical strengths by mixing a little amount of powdery glass fiber. SOLUTION: In a composition containing at least 2-66wt.% of glass fiber as a blended material, 1-60wt.% of (A) chopped strands of glass fiber having 2-30mm length and 2-19μm diameter and 1-60wt.% of (B) powdery glass fiber having 5-100μm average fiber length and 5-23μm diameter are blended to a resin composition and the blended weight ratio of the component A and the component B is brought to 1/40-10/1. As the resin, e.g. a polyamide 66 resin, etc., can be used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin reinforced resin composition, and more particularly to an injection molded article having improved strength and warpage.

[0002]

2. Description of the Related Art Glass fibers having a circular cross section are mixed in a thermoplastic resin to reinforce the resin and improve physical properties, and are widely used for producing various fiber-reinforced plastic molded products. However, the glass fiber has a longer length than the diameter and has anisotropy, so that a mixture of resin and glass fiber is pressed into the mold gate as in injection molding and flows in a certain direction. The thermal expansion coefficient varies depending on the location, and appears as warpage and twist. In order to prevent this warping and twisting, glass flakes with little vertical and horizontal directions, mica, etc. are compounded.
Products containing glass flakes, mica, and the like have a problem that the warpage and torsion decrease in proportion to an increase in the amount, but the mechanical strength decreases. Further, glass flakes are expensive, and there is a problem that a molded product using mica is colored in the color of mica.

[0003]

When glass flakes, mica powder and the like are blended, warpage and torsion of the injection molded product are reduced, but if the blending amount is increased to ensure the effect, the tensile strength etc. However, there is a problem that the mechanical strength of the material rapidly decreases. An object of the present invention is to provide a thermoplastic resin composition in which warpage and twist of an injection-molded article are reduced and strength is less reduced.

[0004]

Means for Solving the Problems The inventors of the present invention have made a product which is commercially available under the name of glass fiber powder or milled fiber (hereinafter referred to as glass fiber powder) and a conventional glass fiber chopped strand into a thermoplastic resin. And injection molding, found that the warpage and torsion of the molded product were reduced and the mechanical strength of the molded product was less reduced compared to the molded product using only ordinary glass fiber chopped strands. As a result of various studies, the present invention has been completed.

[0005]

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermoplastic resin having a diameter of 5-23 .mu.
m, glass fiber powder having an average fiber length of 5-100 μm
1 to 60% by weight, 2-19 μm in diameter and 2-3 in length
1 to 60% by weight of a 0 mm glass fiber chopped strand is blended. At this time, the mixing ratio of the glass fiber powder and the glass fiber chopped strand is 1 / 40-10 /
1, and its proportion to the resin composition is 2-66% by weight. In addition, talc, charcoal, mica,
Materials normally compounded according to the use of the injection molded product, such as inorganic fillers such as glass flakes, flame retardants, pigments, antistatic agents, etc., can be appropriately compounded.

[0006] The thermoplastic resin used in the present invention is not particularly limited in use. Examples thereof include polycarbonate resin, acrylic resin, ABS resin, polyamide resin, saturated polyester resin and polyacetal resin. , Polyphenylene sulfide resin, and alloys of these various resins, or a mixture of two or more of these resins can also be used.

The glass fiber chopped strand used in the present invention is manufactured by a known glass fiber manufacturing method, and a silane coupling agent, a titanium-based coupling agent,
At least one type of coupling agent such as a zirconia-based coupling agent is bundled with a known sizing agent containing an antistatic agent, a film forming agent, and the like, and the collected glass fiber strands are collected and cut into a predetermined length. Used in the form of chopped strands. Its length is usually 2-3
0 mm.

The glass fiber powder used in the present invention is obtained by pulverizing glass fiber by a known pulverizing method. Those having a length of about 10 times or less with respect to the diameter of the cylindrical particles are kept powdery. However, when the length is further increased, each particle becomes a form aggregated in a granular form. Usually, this glass fiber powder contains
The same surface treatment as that of the glass fiber chopped strand is applied. It is desirable that this glass fiber powder is blended in an amount of 1 to 60% by weight, preferably 5 to 50% by weight, based on the resin composition, and ordinary glass fiber is blended in an amount of 1 to 60% by weight, preferably 5 to 50% by weight. It is desirable to do. At the same time, the mixing ratio of these two types of glass fibers is a weight ratio, and the weight ratio of the glass fiber powder to the normal glass fiber is in the range of 1 / 40-10 / 1, preferably 1 / 10-1 / It is desirably 2. If it is 1/40 or less, the effect of adding the glass fiber powder is small, and
With 1 or more, there is no difference in effect as compared with the case where glass fiber powder is blended alone. The total amount of these two types of glass fibers is preferably 2-66% by weight, and more preferably 10-55% by weight, based on the entire resin composition.

[0009] The resin composition of the present invention has less warpage than a conventional composition containing glass fiber alone, and depending on the application, a molded article more suitable for the application can be obtained by adding other inorganic fillers. be able to. Examples of such inorganic fillers include various powders such as silica, fine powder of glass, kaolin, talc, titanium oxide, calcium carbonate, and alumina. Further, known antistatic agents, coloring agents, lubricants, release agents, nucleating agents, flame retardants, impact resistance improvers, and the like can also be added.

These resins, glass fibers and the like are blended, heated, kneaded, extruded by an extruder, and the continuously extruded resin composition is cooled, cut and pelletized. Although a method of molding a pellet by an injection molding machine to obtain a predetermined molded product is a general method, it is also possible to directly injection-mold a mixture without pelletizing. As the glass fiber used in the present invention, a fiber having a general glass fiber composition such as E glass is used, but any composition can be used as long as the glass fiber can be used. is not.

The effect of the present invention is that a small amount of glass fiber powder is used.
When the compound is blended, the effect of reducing the warpage of the screw pre-thermoplasticization type and the in-line screw type injection molded product is remarkable as compared with the case where the compound is not blended.

[0012]

The present invention will now be described by way of examples, which should not be construed as limiting the invention. The evaluation method is as follows. 1. Measurement of physical properties Tensile strength: Measured according to ASTM 0638. Strength after water absorption: A test piece used for tensile strength is placed in a pressure cooker, treated at 120 ° C. for 15 hours, and then subjected to the above tensile test. 2. Measurement of warpage A 120 mm square flat plate test piece (thickness: 3 mm, gate is one place at the center of the side) is molded, and the test piece is placed on a flat platen and the maximum distance from the platen is measured. The portion was measured as the amount of deformation.

Examples 1-3 As shown in Table 1, 70% by weight of polyamide 66 resin (Nylon 6621015B manufactured by Ube Industries) was used as the resin, and the glass fiber had a fiber diameter of 10 μm and an average fiber length of 2%.
Glass fiber powder provided with 6 μm and 0.1% by weight of aminosilane and a glass fiber chopped strand having a fiber diameter of 13 μm and a fiber length of 3 mm (CS3PE-94 manufactured by Nitto Boseki)
8) was used. These resins and glass fibers were dried in a hot air circulating drier for 12 hours at 120 ° C. for 6 hours, and these materials were blended in the proportions shown in Table 1, premixed, and immediately set at a cylinder temperature of 280 ° C. The mixture was extruded by a twin-screw vented extruder and cut into pellets. Next, the obtained pellet was dried at 120 ° C. for 6 hours, and then a test sample was molded using an injection molding machine.

Comparative Example 1-6 The matrix resin and glass fiber used in the examples were used. The glass flakes had an average particle diameter of 100 μm, the average thickness was 4 μm, and the mica had an average particle diameter of 1 μm.
One having a thickness of 95 μm and an average aspect ratio of 75 was used. The proportions of these materials are shown in Table 1. Other molding conditions were the same as in the examples, and test samples were prepared using an injection molding machine.

[0015]

As is clear from the tables of Examples and Comparative Examples, when glass flakes and mica powder are blended to prevent warping of a molded product, any of them has a tensile strength,
Water resistance is greatly reduced. However, the injection molded product using the glass fiber chopped strand and the glass fiber powder in combination according to the present invention has a small decrease in tensile strength and water resistance,
In addition, there is an effect that the sled is also small.

[0016]

[Table 1]

Claims (2)

[Claims] 1. At least 2-66% by weight as a compounding material
In the thermoplastic resin composition for injection molding containing the glass fiber of (1), a glass fiber chopped strand having a length of 2 to 30 mm and a diameter of 2 to 19 μm is 1 to 60% by weight based on the resin composition, and the average fiber length is 5 to 5. 100 μm, glass fiber powder having a diameter of 5 to 23 μm is 1 to 60% by weight,
A thermoplastic resin composition for injection molding, wherein the weight ratio of the glass fiber powder to the glass fiber chopped strand is 1 / 40-10 / 1. 2. A resin molded article obtained by molding the thermoplastic resin composition according to claim 1.