JPH115870A - Thermosetting resin-forming material and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject forming material excellent in productivity and qualities without spoiling mechanical strengths, dimensional stability, heat resistant, etc., by blending and kneading solely a glass woven fabric or together with chopped strands of glass fiber as essential components of fillers to a thermosetting resin. SOLUTION: This thermosetting resin-forming material without generating pillings during kneading and in the forming material by blending 20-70 wt.%, preferably 30-50 wt.% of a thermosetting resin, 20-60 wt.%, preferably 40-60% of a glass woven fabric (e.g. edge pieces of a glass fabric generated in a production process, etc., of epoxy resin laminates) solely or together with chopped strands of a glass fiber and bringing the shape of the glass woven fabric after kneading to be monofilaments having 10-500 μm fiber length.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosetting resin molding material having excellent mechanical strength, dimensional stability, heat resistance and the like by blending a glass woven fabric, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, glass-filled thermosetting, which has excellent strength, heat resistance, dimensional stability, stress relaxation characteristics, etc. in accordance with demands for miniaturization, weight reduction and high performance of structural and mechanical parts such as automobiles and electric parts. Resin molding materials are attracting attention as metal substitutes. The raw material form of glass fiber usually used as a filler is a so-called chopped strand obtained by bundling hundreds of monofilaments having a fiber diameter of about 5 to 15 μm and then cutting them to a predetermined length after applying the surface treatment agent. It is common to use the type of glass fiber called, and rarely use other forms of glass fiber. Therefore, the molding material price naturally depends on the price of the glass fiber to be blended at a high level, and the glass fiber is expensive, so that it has not actually led to a significant cost reduction.

[0003] However, at the early stage of the raw material charging and mixing stage of the production process of the thermosetting resin molding material, a part of the glass fiber, which should remain bundled, is defibrated into a ball-like shape, which causes clogging of pipes and hopper bridges. In some cases, this may be caused or mixed in the molding material, which may cause poor appearance during molding, and may significantly deteriorate productivity and quality. To prevent this, it is effective to improve the focusing power.However, when chopped strands are formed into a molding material and become a constituent unit of a thermosetting resin molding material,
Since the various properties are exhibited only when the monofilament is dispersed again in the material as a monofilament, there is naturally a limit to the improvement of the focusing power. On the other hand, the inventor has learned from experience that the impact strength can be improved by suppressing the shearing of the glass fiber when forming the molding material and leaving the remaining fiber length in the material longer, but on the other hand, the glass fiber and the resin It was inevitable that the adhesion at the interface was reduced and pills were easily generated.

[0004]

DISCLOSURE OF THE INVENTION The present invention was made as a result of various studies in order to solve such problems that may occur in the process of producing a conventional glass-filled thermosetting resin molding material. The reason is that thermosetting resin molding with excellent productivity and quality without impairing the mechanical strength, dimensional stability, heat resistance, etc., which are the characteristics of thermosetting resin molding material using glass fiber as filler. An object of the present invention is to provide a material and a method for manufacturing the same.

According to the present invention, as a result of various studies, even if a glass woven fabric is blended with a thermosetting resin molding material, mechanical properties almost equal to those obtained by blending a chopped strand, which is a conventional technique, can be obtained. This led to the completion of the present invention. In the present invention, if a piece of glass woven fabric is used as the glass woven fabric, it is possible to effectively use the scrap material that has been usually discarded or regenerated at a high cost,
Further, since the cost of raw materials can be significantly reduced, the cost of materials can be reduced.

[Means for Solving the Problems]

According to the present invention, in a thermosetting resin molding material, a glass woven fabric is blended with a thermosetting resin as an essential component of a filler alone or in combination with a glass fiber chopped strand and kneaded. A thermosetting resin molding material characterized by comprising: preferably 20 to 70% by weight, preferably 30 to 50% by weight, and filling of the thermosetting resin with respect to the entire thermosetting resin molding material. A thermosetting resin molding material obtained by mixing and kneading 20 to 60% by weight, preferably 40 to 60% by weight of a glass woven fabric alone or in combination with a glass fiber chopped strand as a material, The woven glass fabric after kneading is in the form of a single fiber and has a fiber length of 10 to 500 μm. Further, the present invention provides a method for producing a thermosetting resin molding material containing glass fiber as a filler, wherein the glass fiber is blended in the form of a glass woven fabric and kneaded. It is a manufacturing method, more preferably 20 to 70% by weight, preferably 30 to 50% by weight of a thermosetting resin and preferably a glass woven fabric alone or a chopped glass fiber as a filler. The method for producing a thermosetting resin molding material as described above, wherein the composition is blended with a strand in an amount of 20 to 60% by weight, preferably 40 to 60% by weight.

[0007]

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermosetting resin molding material containing a glass fiber as a filler, wherein the raw material of the glass fiber to be compounded is a glass woven fabric. The present invention relates to a material and a method for producing the same. According to the present invention, productivity and quality are maintained while maintaining mechanical strength, dimensional stability, heat resistance, and the like, which are features of a glass fiber-filled thermosetting resin molding material. Can be improved.

When the thermosetting resin molding material of the present invention is obtained, usually, a glass woven fabric is cut into a predetermined size by a rotary cutter or the like and used as one of the raw materials. The cut woven fabric is uniformly mixed with other raw materials, that is, a resin, a curing agent, a curing aid, a filler, a release agent, a pigment, and the like, if necessary, and is usually kneaded with a kneading machine. Alternatively, the mixture is mixed with other raw materials, and is kneaded by a kneader, and is charged into the kneader and heated and kneaded. Thereafter, the mixture is cooled and pulverized to obtain a molding material. The kneader is used alone with a roll, a co-kneader, a twin-screw extruder or a combination of a roll with a co-kneader, a twin-screw extruder or the like. Furthermore, pelletization may be performed using a twin-screw extruder, a single-screw extruder, or the like. When the raw material mixed with the glass woven fabric is heated and kneaded and pulverized, the woven fabric is loosened, and the glass fibers constituting the yarn are cut and separated during kneading, and are uniformly dispersed as short fibers in the molding material. Therefore, a molding material having the same properties as those obtained when the chopped strand of glass fiber is blended is obtained. Glass woven fabrics can be better in terms of mechanical properties because, in some cases, they are present with longer fiber lengths in the molding material than in the case of glass fiber chopped strands.

[0009] The glass woven fabric untwists during kneading to become a single fiber, is uniformly dispersed in the molding material, and has the same properties as in the case of chopped strands, but does not untwist before the kneading step. Therefore, it has the feature that pills do not occur during kneading or in the molding material. As the glass woven fabric used here, if the scrap material of the glass woven fabric generated in the manufacturing process of the epoxy resin laminate is used, the raw material cost can be reduced,
And it can be recycled. As a method of supplying the glass woven fabric or its scrap material, the glass woven fabric or the cut material is cut into a predetermined size (for example, 1 to 10 × 1 to 10 cm) in advance, and before the kneading step in forming the molding material, another Is preferred, but the method is not particularly limited to this method, and it can be added immediately before or during kneading.

The fiber diameter of the glass woven fabric used in the present invention is desirably 5 to 15 μm from the balance of the reinforcing effect. Glass woven fabric alone or in combination with chopped strands is 20 to 6
It is desirable to add 0% by weight, preferably 40 to 60% by weight. If it is less than 20% by weight, a sufficient reinforcing effect cannot be obtained, and if it exceeds 60% by weight, the workability at the time of materialization is deteriorated, and the flowability of the molding material is reduced, so that the moldability is reduced.
This is because the strength of the molded product is reduced.

The thermosetting resin used here may be any one of phenol resin, epoxy resin, melamine resin, unsaturated polyester resin, diallyl phthalate resin and the like, and is not particularly limited. For example, in the case of a phenolic resin, the amount of the resin is 20 to 70% by weight, preferably 30 to 50% by weight based on the entire molding material, from the viewpoint of workability, moldability, and characteristics of the obtained molded product at the stage of forming a molding material.
It is desirable that Next, fillers other than glass fibers will be described. In the present invention, other inorganic fillers may be blended in order to improve the dimensional stability and heat resistance of the molded product. Aluminum hydroxide as such an inorganic filler,
Examples include talc, calcium carbonate, clay, and mica. If necessary, an organic filler such as pulp or crushed woven material can be blended. The thermosetting resin molding material of the present invention has excellent mechanical strength for automobiles, electricity,
This can be an effective means to greatly promote the replacement of metals such as electronic components.

[0012]

Examples of the present invention will be described below. The glass woven fabric was used by cutting off a piece of glass woven fabric for a printed circuit board into a predetermined size. Raw materials other than this glass woven fabric
The mixture was previously mixed in a blender, preliminarily kneaded in a twin-screw kneader, then kneaded with a heating roll, cooled and pulverized to obtain a phenolic resin molding material. In Example 1, the waste material of the glass woven fabric was added at the stage of kneading with a heating roll, and in Examples 2, 3 and 4, it was added at the stage of preliminary kneading with a biaxial kneader. The composition of the raw materials is as shown in Table 1, but the following materials were used for the scraps of glass woven fabric and glass fibers.・ Glass woven material A: Glass woven material (fiber diameter 9 μm)
Cut to 100 mm x 100 mm.・ Glass woven material B: Glass woven material (fiber diameter 7 μm)
Is cut into 10 mm x 10 mm. Glass fiber: chopped strand having a fiber diameter of 10 μm and a cut length of 3 mm. Transfer molding (175 ° C / 3
A test piece for property evaluation was molded by the (minute curing) and the property evaluation was performed based on JIS K 6911. Table 1 shows the results.

Table 1 Example Comparative Example 1 2 3 4 1 << Composition (parts by weight) >> Novolak resin 35 35 35 35 35 Hexamethylenetetramine 5 5 5 5 5 Glass fiber 25 50 Glass woven cloth scrap A 50 50 Glass woven cloth scrap B 50 25 Release agent, pigment, etc. 10 10 10 10 10 << Characteristics >> Appearance of molded article Good Good Good Good Good Specific gravity 1.8 1.8 1.8 1.8 1.8 1.8 Flexural strength (MPa) 210 230 230 210 210 200 Tensile strength (MPa) 120 120 120 120 120 Charpy impact strength (KJ / m ² ) 5.0 4.5 4.5 4.3 4.3 4.0 Mold shrinkage (%) 0.3 0.3 0.3 0.3 0.3 Residual fiber length (μm) 150 120 120 110 100

[0014]

As is clear from the examples and comparative examples,
The thermosetting resin molding material of the present invention is excellent in mechanical strength and greatly promotes replacement of metals in the fields of automobiles, electricity, and electronics. INDUSTRIAL APPLICABILITY The thermosetting resin molding material and the method for producing the same according to the present invention can effectively utilize the scrap material of glass woven fabric that has been conventionally discarded as unnecessary material, and is extremely useful for improving productivity and quality. . in this way,
Productivity and quality can be improved while maintaining characteristics such as strength, dimensional stability, and heat resistance, which are characteristics of thermosetting resin molding materials such as glass fiber-filled phenolic resin molding materials.

Claims (5)

[Claims] In a thermosetting resin molding material, a glass woven fabric is used alone as an essential component of a filler in a thermosetting resin;
Alternatively, a thermosetting resin molding material characterized by being blended and kneaded with a glass fiber chopped strand together with this. 2. A thermosetting resin is used in an amount of 20 to 70% by weight based on the whole thermosetting resin molding material, and a glass woven fabric is used alone or in combination with a glass fiber chopped strand. The thermosetting resin molding material according to claim 1, which is blended in an amount of 20 to 60% by weight. 3. The thermosetting resin molding material according to claim 1, wherein the glass woven fabric after kneading is a single fiber and has a fiber length of 10 to 500 μm. 4. A method for producing a thermosetting resin molding material containing glass fiber as a filler, wherein said glass fiber is blended in the form of a glass woven cloth and kneaded. Manufacturing method. 5. A thermosetting resin is used in an amount of 20 to 70% by weight based on the entire thermosetting resin molding material, and a glass woven fabric is used alone or in combination with a glass fiber chopped strand. The method for producing a thermosetting resin molding material according to claim 4, wherein the composition is blended in an amount of 20 to 60% by weight.