JP2519764B2 - Stamping molding material with improved strength - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a stamping molding material composed of a long fiber material and a thermoplastic resin and having a directional strength that enables stamping molding.

(Prior Art) A composition in which a thermoplastic resin is impregnated into a mat of fibers and integrated therein is known as a stampable sheet. Molding using stampable sheets (stamping molding)
Is performed by supplying the heat-melted sheet between a pair of heated molds and applying pressure to shape the sheet. Stamping molding generally has high productivity because the time required for molding is short, unlike molded products, it does not rust, and because it has high strength and elastic modulus relative to specific gravity, it is possible to reduce the weight. Widely used in.

Conventionally, what is known as a stampable sheet is
It is made by impregnating resin into a needle-punched long fiber mat or a mat made of chipped strands.

Molded products of these stampable sheets are characterized in that they have no directionality in terms of physical properties and have uniform mechanical properties. However, the mechanical strength of various members used in practice is uniform. Is not necessary. That is, there are some members that require very high bending strength and rigidity in a certain direction. For example, in the case of a member such as a beam, when a conventional homogeneous stampable sheet is used, the strength necessary for the design is secured, so that the member becomes thick as a whole and it is difficult to reduce the weight.

As a method to deal with these problems, it is possible to impregnate the fibrous materials in one direction and impregnate them with a resin, and then use the amount necessary for the design in the required part. Has been done. (Japanese Patent Publication No. 62-13906, Japanese Unexamined Patent Publication No. 62-19429, Japanese Unexamined Patent Publication No. 62-11735, etc.) (Problems to be solved by the invention) However, unidirectionally aligned fibers are impregnated with a resin. In some cases, there are many problems.

One of them is that in the process of impregnating and integrating the resin using only the fibers aligned in one direction, a large tension is applied in the fiber direction to heat the resin in order to impregnate the resin without disturbing the arrangement of the fibers. It is necessary to apply a method such as pressing, or aligning the fibers to which the resin is attached in advance and then applying heat and pressure.

When an epoxy resin or an unsaturated polyester resin, which is a thermosetting resin, is used as the resin, a material that has been increased in viscosity after being impregnated, that is, a material integrated by a process called B-stage or aging is used. It is necessary to be able to handle the fiber arrangement without disturbing it.

When a thermoplastic resin is used as the resin, it is difficult to supply the fiber array impregnated and aligned with the resin to the molding die without being disturbed by the heating and melting before molding, and the impregnated resin It is necessary to loosely join the aligned fibers to each other beforehand. Separately, in an example in which fibers that are aligned in one direction are used together with a chopped strand, it is known to have layers that are sequentially laminated on each other, but the mechanical properties of a molded product using this are However, there is only an improvement in tensile strength corresponding to the amount of fibers contained in the aligned fiber directions.

Further, mechanical properties are improved by combining upper and lower layers made of a stampable sheet containing fibers aligned in one direction and a stampable sheet containing fibers having no directionality as an intermediate layer at the time of molding. However, according to such a method, a very thin unidirectional stampable sheet is required to obtain a molded product having a small thickness,
In addition to the difficulty in manufacturing, it is also difficult to supply the fibers, which are heated and melted in one direction and aligned in one direction, into the molding die during molding, and it is not practical because the overlapping work during molding is complicated.

The object of the present invention is to improve the above-mentioned drawbacks found in conventional stamping molding materials, and to expand the range of application in the industrial field, easy production, good handling at the time of molding, In addition, it is possible to design and use a material for mechanical properties required for a molded product, and to provide a stamping molding material that can effectively use the physical properties of fibrous materials aligned in one direction. is there.

(Means for Solving the Problems) According to the present invention, the above-mentioned object is a stamping molding material comprising an inorganic fiber reinforcing material impregnated and integrated with a thermoplastic resin, wherein the outermost layer of the material is an inorganic long fiber. The innermost layer contains mat-shaped reinforcing material made of inorganic fibers, and the outermost layer and the innermost layer are reinforced in one direction with the inorganic fiber reinforcing material being the outermost layer. This is achieved by providing a stamping molding material characterized in that it is included adjacent to the reinforcement of the innermost layer.

An important point in the present invention is that between the mat-shaped reinforcing material made of inorganic fibers and the cross-shaped reinforcing material made of inorganic long fibers, the reinforcing material made of inorganic long fibers aligned in one direction. Since it is configured to be protected, when the reinforcing material is impregnated with the thermoplastic resin, the arrangement of fibers in the reinforcing material made of inorganic long fibers aligned in one direction is less likely to be disturbed, and Similar effects are exhibited even when stamping molding material is stamped, so that the resulting molded product has extremely good mechanical properties in a specific direction.

Further, since the outermost layer is provided with the cross-shaped reinforcing material, the strength in the direction perpendicular to the direction of the fibers aligned in one direction is also improved.

The inorganic fibers and the inorganic long fibers used in the present invention are glass fibers, carbon fibers, metal fibers, ceramic fibers, various whiskers, and the like, and these fibers can be used alone or in combination of two or more. Further, it is desirable to use carbon fibers, glass fibers, metal fibers or the like having high strength and elastic modulus as the inorganic long fibers aligned in one direction. It is possible to use various fibers as the fibers for forming the innermost layer, and the shape may be a cut fiber in a mat shape, or a needling formed by forming a non-directional mat made of long fibers. These may be used or these may be combined.

The cloth-like reinforcing material composed of inorganic long fibers used in the present invention means a thin woven fabric or a tape-like material obtained by weaving yarn in which one to several strands of inorganic long fibers are twisted and wound. . As the inorganic long fibers used here, various fibers can be used, but glass fibers, carbon fibers and the like are preferably used.

The diameter of the fiber used in the present invention may be any, but it is preferably about 2μ to 30μ, and the surface of the fiber is treated with a silane coupling agent or the like so as to give an adhesive property suitable for the thermoplastic resin used. It is desirable that it has been processed.

The thermoplastic resin used in the present invention is, for example,
Polyethylene terephthalate, polybutylene terephthalate, polypropylene, polyethylene, polyamide, polycarbonate, polysulfone, polyacetal, polyarylate, polyether ether ketone, polyphenylene sulfide, polyphenylene oxide, thermoplastic polyurethane, polymethylmethacrylate, polyvinyl chloride , Polyvinylidene chloride, polystyrene, styrene-butadiene-acrylonitrile copolymer, and the like, and includes a mixture of two or more of these. In the present invention, polyethylene terephthalate is particularly preferably used. These resins include commonly used plasticizers, heat stabilizers and light stabilizers, nucleating agents, fillers, dyes and pigments, internal release agents, processing aids, impact resistance agents, extenders, crushed inorganic fibers. Etc. can be added as appropriate.

The method for producing the stamping molding material in the present invention is not particularly limited, and for example, it can be prepared by placing a thermoplastic resin sheet of an appropriate thickness between the reinforcing fiber layers and heating and pressing to integrate them. I can. The cross-shaped material made of inorganic long fibers used here has a thickness of 0.03 mm to 1.0 mm.
Degree, the unit weight 25g / m ² ~1000g / m ² approximately, one-way consists引揃the obtained fiber layer 100g / m ² ~2000g / m ² approximately, mat-like reinforcing layer of the innermost layer is 100 g / About m ^{2 to} 4000 g / m ² is preferable, but the thickness, unit weight, etc. may be changed if necessary. Further, the ratio of the thermoplastic resin to the reinforcing fiber is preferably about 50% to 80% by weight of the resin.

The stamping molding material of the present invention thus obtained can be used for a number of purposes by utilizing its directional strength. For example, automobile parts such as bumper beams and chassis, building materials such as I-beams, and civil engineering articles. Is applicable to.

Further, the stamping molding material of the present invention can be used in combination with various molding materials including conventional stamping molding materials.

(Examples) The present invention will be described using specific examples, but the present invention is not limited to the following examples.

Example 1 A glass cloth (trade name: WF110D 100BV, manufactured by Nitto Boseki Co., Ltd., thickness: 0.15 mm, 97 g / m ² ) and a mat made of unidirectionally aligned glass roving and glass short fibers are 300 g / m, respectively. ^One layer of inorganic fiber laminated by ^two (trade name:
Lamimatsu LM303KA-104 (manufactured by Nittobo Co., Ltd.) reinforcement material and 45
Four layers of 0 g / m ² of Chopped Strand Matte (manufactured by Nitto Boseki Co., Ltd., product name MC450S) are sequentially laminated in the configuration shown in FIG. 1 to form a polyethylene layer having a thickness of 0.2 mm between the layers. After stacking sheets of terephthalate resin so that the weight ratio of glass fiber to resin is 60%, then 290 to 300
The mixture was heated to ℃ and pressure-impregnated at a pressure of 10 kg / cm ² . The obtained stamping molding material is dried at 140 ℃ for 4 hours and then 290 ℃ -30
200kg / with a mold heated to 0 ℃ for 10 minutes and heated to 160 ℃
The physical properties of the molded product obtained by stamping molding under a pressure of m ² were 40 kg / mm ^{2 in} bending strength in the direction of the fibers aligned in one direction, and 15 kg / mm ² in the direction perpendicular to the fibers.

This stamping molding material had no problem in handling in a heated and melted state, and the bending strength in the direction perpendicular to the fibers was confirmed to be almost doubled as compared with the molded product in which the glass cloth was not used as the outer layer. (See Comparative Example 2) Comparative Example 1 A sheet made up of 6 layers of 450 g / m ² of Chiropped Strand Matte (manufactured by Nitto Boseki Co., Ltd., product name MC450S) and a polyethylene terephthalate resin having a thickness of 0.2 m / m. After sequentially stacking the resin so that the weight ratio thereof was 60% of the resin, a stamping molding material was obtained in the same manner as in Example 1, and the stamping molding material was further obtained, and the physical properties were measured. As a result, the bending strength was 25.0 kg / mm ² .

Comparative Example 2 A stamping molded article was obtained in the same manner as in Example 1 except that glass cloth was not used. The physical properties of the obtained molded article were a bending strength of 38 kg / mm ² in the fiber direction and a bending perpendicular to the fiber. The strength was 8.2 kg / mm ² , and the strength in the direction perpendicular to the fiber was not sufficiently obtained.

(Effects of the Invention) The stamping molding material of the present invention has directionality in strength and can be applied to many uses.

[Brief description of drawings]

FIG. 1 is a sectional view of a stamping molding material of the present invention. 1. A layer of a cross-shaped reinforcing material of inorganic long fibers impregnated with a thermoplastic resin 2. A layer of a reinforcing material made of inorganic long fibers aligned in one direction impregnated with a thermoplastic resin. 3. Mat-like reinforcing material layer made of inorganic fiber impregnated with thermoplastic resin

Claims (5)

(57) [Claims] 1. A stamping molding material comprising an inorganic fiber reinforcing material impregnated and integrated with a thermoplastic resin, wherein the outermost layer of the material comprises a cross reinforcing material comprising inorganic long fibers, and the innermost layer comprises inorganic fiber. Including mat-shaped reinforcement,
A stamping molding material, characterized in that a reinforcing material composed of inorganic long fibers aligned in one direction is included between the outermost layer and the innermost layer adjacent to the reinforcing materials of the outermost layer and the innermost layer. 2. The stamping molding material according to claim 1, wherein the thermoplastic resin is polyethylene terephthalate. 3. The stamping molding material according to claim 1 or 2, wherein the cloth-shaped reinforcing material made of inorganic long fibers is glass cloth. 4. The glass chopped strand mat according to claim 1, wherein the mat-like reinforcing material made of inorganic fibers is a glass chopped strand mat.
The stamping molding material according to any one of items 1 to 3. 5. The stamping molding according to any one of claims 1 to 4, wherein the reinforcing material composed of inorganic long fibers aligned in one direction is a reinforcing material composed of glass fibers. material.