JPH0225307A - Manufacturing method of molding material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing a molding material having excellent moldability and having a thermoplastic resin as a matrix.

[Conventional technology and Problems that the invention seeks to solve]

A typical material for fiber-reinforced plastics having a thermoplastic resin as a matrix is injection molding pellets in which reinforcing fibers are cut into several pieces or less than one size and dispersed in a thermoplastic resin. In addition, there are plate-shaped press molding materials in which chopped fibers cut into several meters are dispersed in thermoplastic resin, and plate-shaped materials in which continuous reinforcing fibers are spread out in a loop shape and impregnated with thermoplastic resin. It has existed as a typical example, and although these characteristics are excellent in formability, it has been pointed out that the problem is that the strength utilization rate is low and the fiber content (hereinafter abbreviated as Vf) cannot be increased. ing. All of these problems are due to the random orientation of fibers in the material.

On the other hand, are there any materials in which continuous tow-shaped reinforcing fibers (hereinafter abbreviated as tow) are impregnated with thermoplastic resin?
In this case, the fiber orientation is sufficient and it is possible to improve Vf, but since the fibers are continuous, it is not possible to shape them into a three-dimensional shape, and the application is limited to materials for flat plates. Ta.

In conventional methods, the above two molding materials have their own drawbacks, and when the cut reinforcing fibers are dispersed in a thermoplastic resin in an oriented state, the above problems can be solved. Although this was predicted, at present no effective manufacturing method has been found.

The object of the present invention is to provide a new method for producing a molding material in which cut reinforcing fibers are dispersed in a thermoplastic resin in a well-oriented state.

[Means to solve the problem]

The gist of the present invention is to obtain a sheet-like aggregate from a film-like material obtained by forming a thermoplastic resin into a film or a tow-like material obtained by spinning and a substantially non-twisted inorganic fiber tow-like material. Then, under the tension of the sheet-like aggregate, the inorganic fiber tow-like material is cut, thereby separating the cut inorganic fibers and the film-like material or tow-like material obtained from the thermoplastic resin in a continuous state. A method for producing a thermoplastic molding material, characterized by obtaining a sheet-like molding material comprising:

The present invention will be explained below with reference to the drawings.

FIG. 1 shows a basic conceptual diagram of the method of the invention. The substantially untwisted reinforcing fiber tow (1) and, for example, the thermoplastic fiber tow (2) obtained from the thermoplastic matrix resin are abraded under tension with, for example, several fixed rods before reaching FIG. By this, the tension is made uniform, each fiber is divided, and preferably the tows (1) and (2) are mixed, and then the tows (1) and (2) are fed to the feed roll (3). The feed roll (3) is
It is necessary to be able to nip the sheet-like aggregate consisting of , and the sheet-like aggregate is taut.

That is, the feed roll (3) and delivery roll (4) provide a trough to the sheet-like aggregate. By selecting this draft for whitening, the reinforcing fiber tow can be continuously cut.

This means that the elongation at break of the inorganic reinforcing fiber tow is much lower than that of the matrix tow, and the elongation at break of the inorganic reinforcing fiber tow is much lower than that of the matrix tow. It is possible to do one thing.

Further, by using an auxiliary means such as a breaker knife shown in symbol (5), it is also possible to easily cut the reinforcing fiber tow under a low draft.

In the present invention, cutting of the reinforcing fibers is performed by placing the sheet-like aggregate under tension, which does not at least hinder the cutting of the reinforcing fibers.

It has long been known that an inorganic reinforcing fiber tow is stretched by two pairs of rolls and then cut continuously, or because reinforcing fiber tow does not have crimps, a sheet-like product made of cut fibers is used. (It was impossible to treat it as an engineering continuum, and it did not exist as a practical technology.

In the method of the present invention, most of the matrix fiber tow reaches the delivery roll (4) without being cut, and the cut inorganic reinforcing fibers are oriented in the longitudinal direction and dispersed in the matrix fiber tow. It becomes possible to maintain the structure. In other words, by giving the matrix tow a role as a carrier for reinforcing fibers, it is possible to obtain a sheet-like product containing cut reinforcing fibers.

As mentioned in the explanation of the above method, the most typical sheet-like material obtained from the thermoplastic resin used in the method of the present invention is a tow-like material obtained by bundling fibers obtained by spinning the resin. Alternatively, as shown in FIG. 2, it is also possible to interpose reinforcing fiber tows in a plurality of films obtained from the resin and cut the reinforcing fibers. When a film is used instead of a film, the process is similar to that when fibers are used, and the performance is almost the same, but better economical efficiency can be obtained.

As the thermoplastic resin, low melting point copolymer polyamide, polybutylene terephthalate, polyethylene terephthalate, etc. can be used as appropriate, and there is no particular limitation.

Further, the reinforcing fiber tow used in the method of the present invention is preferably a substantially untwisted tow, and it is preferable that the surface treatment of the sizing agent of the tow is removed. Examples of inorganic reinforcing fibers include glass fiber, alumina fiber, carbon fiber, etc., and the types are not particularly limited. It is necessary to have a degree.

The structure in which cut inorganic reinforcing fibers are present in the sheet-like material obtained from the thermoplastic resin that has not been cut in the longitudinal direction obtained in this way is passed through the delivery roll (4) and then passed through the delivery roll (1). ) It is possible to use the material as it is as a unidirectional thermoplastic matrix molding material that can be rolled up with release paper interposed and can be highly deformed with high orientation and high Vf.

(2) It can be used as a unidirectional thermoplastic matrix molding material by immediately melting part or all of the thermoplastic resin. The fixing method is not particularly limited, but the simplest method is partial heat welding using a heat pattern roll. The partially welded material has excellent flexibility and also has the property of preventing misalignment between the laminations. The thermal belt method is convenient for total melting, but
The misalignment between the laminated layers can be easily accommodated in small molded products, and can be used in long molded products. This material can be wound as is without release paper, and is not suitable for molding that requires large deformations, but it is a material with excellent handling properties for small deformations.

〔Example〕

The present invention will be explained in more detail below with reference to Examples.

Example 1 Substantially untwisted carbon fiber tow 8 of well-washed 12
The books were arranged at 15-square intervals and rubbed on a satin matte roll to form a sheet with no cracks.

Separately, a 30 micron thick copolyamide having a melting point of 110 to 120 DEG C. was split in a conventional manner to have a splint width of 0.5 degrees to obtain a split film.

Split films were laminated on top and bottom of a sheet-like carbon fiber sheet so that the carbon fiber sheet served as an intermediate layer, and the laminated film was passed through a rotating matte finish roll and led to a feed roll. The distance between the feed roll and delivery roll is 300 mm, and a breaker made of alumina porcelain is used.
The distance between the bar and the delivery roll was 50 mm, the draft provided by the feed roll and the delivery roll was about 5%, and the delivery speed was 60 m/min.

When the split film and carbon fiber sheet were passed under these conditions, the split film was not cut and remained continuous, but the carbon fibers were cut into approximately 70 to 80 m lengths and were completely oriented in the longitudinal direction. A unidirectional molding material having a width of about 10 tM in which carbon fibers were dispersed in a split film sheet was obtained.

Since this molding material has an unstable structure, in order to further improve its handling performance, it is passed through a heated roll having streaks at a pitch of 10 degrees in the circumferential direction, melting a part of the polyamide, and forming a sheet. was fused and fixed in the medial direction.

The obtained unidirectional molding material has flexibility,
Laminate the required number of sheets according to the fiber orientation required for the molded product,
It can be used for three-dimensional press molding.

Example 2 In Example 1, polybutylene terephthalate having a melting point of around 220°C was spun into untwisted filament yarn of 500 denier 9° filaments instead of the co-polyamide split film, and after washing the spinning oil. Using a film-like material in which 20 pieces are arranged at an 8ml pitch and formed into a sheet without cracks, the lengths of both film-like products can be mixed,
After being dispersed, the carbon fibers were cut under the same conditions as in Example 1 to obtain a sheet-like aggregate containing carbon fibers cut into 70 to 80 m lengths and having polybutylene terephthalate as a continuous thread. This sheet-like aggregate was immediately passed through a hot embossing roll for point adhesion to obtain a unidirectional molding material having dotted fusion points. This material has flexibility similar to Example 1,
Although the mixing condition was better than that of Example 1, the lamination and molding performance was as satisfactory as in Example 1.

〔Effect of the invention〕

By using the method of the present invention, the cut fibers essential for molding a three-dimensional object can be oriented at 1100% V1, making it possible to efficiently produce a molding material present in a matrix.

[Brief explanation of the drawing]

1 and 2 are conceptual diagrams of the reinforcing fiber cutting process utilized in the present invention. 1.2.2'...Tow 3...Feed roll 4...Delivery roll 5...Play carver Figure 7 procedural amendment (voluntary) 1. Patent Application No. 63-1765 2. Name of the Invention Relationship with the Case of Person Who Amends the Manufacturing Method of Molding Materials Patent Applicant No. 28, 2-3-19 Kyobashi, Chuo-ku, Tokyo (606) President and Director of Mitsubishi Rayon Co., Ltd. Yatabe Nagai 4, Substitute No. 19, 2-3, Kyobashi, Chuo-ku, Tokyo 104 The specification is amended as follows. Page 5, line 10, next to ``1 Reinforcing Fiber'' add ``IJ Tuxedo (IJT) cutting fee''. 2) On page 9, line 16, add "average fiber length" after "fiber". Specification “Detailed description of the invention” column

Claims (1)

[Claims] 1. A sheet-like aggregate is obtained from a film-like material obtained by forming a thermoplastic resin into a film or a tow-like material obtained by spinning and a substantially untwisted inorganic fiber tow-like material, and then the sheet-like aggregate is tensioned. Below, by cutting an inorganic fiber tow-like material, a sheet-like molding material consisting of cut inorganic fibers and a film-like material or a tow-like material obtained from a thermoplastic resin in a continuous state is obtained. Characteristic manufacturing method for thermoplastic molding materials.