JPH07314570A - Method of coating reticulate structure with resin - Google Patents

Abstract

PURPOSE:To apply the desired amount of thermoplastic resin on a reticulate structure consisting of heat-resistant fibers without generating clogging of meshes due to applied resin. CONSTITUTION:Thermoplastic resin films 2 are laminated on the upper and lower surfaces of a reticulate structure 1. Soft sheet type materials 3a are laminated on the upper and lower surfaces thereof and mold parting sheets 5 are superposed on the outside thereof if necessary, then, the laminate is pressed under heating by hot press boards 4. The thermoplastic resin films are welded by fusion to each other through the meshes thereof. The laminate is heated at a temperature higher than the melting point of the thermoplastic resin films to aggromerate the thermoplastic resin films. Spaces are formed in the meshes while the surfaces of the fibers of reticulate structure are coated by the thermoplsatic resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of coating a thermoplastic resin on the fiber surface of a network structure composed of heat resistant fibers.

[0002]

2. Description of the Related Art Conventionally, when a net-like structure made of a heat-resistant fiber such as glass fiber, carbon fiber or aramid fiber, a woven fabric or a cross-woven fabric is coated with a thermoplastic resin, , A method of immersing a network structure in a resin solution in which a thermoplastic resin is dissolved and then drying, or a method of thermally melting the thermoplastic resin and drawing it out together with the network structure from a T die and then drying (pull-out molding method). It is being appreciated.

However, the method of immersing in a resin solution and then drying it has a problem that the viscosity of the resin solution is extremely high even if the resin solution is at a low concentration, and the resin solution adheres too much and the mesh of the network structure is easily clogged. There is a point. If the solution concentration is lowered to avoid this, naturally there is a problem that only a small amount of resin is coated, the solvent is not easily removed by drying, and microvoids are more likely to occur.

On the other hand, the pultrusion molding method has a problem that it is difficult to coat with a small amount of resin adhered and the mesh is easily clogged.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to coat a network structure made of heat resistant fibers with a desired amount of thermoplastic resin. At the same time, another object of the present invention is to provide a method for coating a reticulated structure with a thermoplastic resin, which does not cause clogging of networks and microvoids caused by the resin.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to laminate a thermoplastic resin film on the upper and lower surfaces of a network structure made of heat resistant fibers, and further to laminate a soft sheet material on the upper and lower surfaces thereof. After heating under pressure, the thermoplastic resin film disposed on the upper surface of the network structure and the thermoplastic resin film disposed on the lower surface are fused at the network of the network structure, and then the melting point of the thermoplastic resin film. Heated above,
This is achieved by a resin coating method for a network structure, which comprises coagulating the thermoplastic resin film to form a space in the network and coating the network structure with the thermoplastic resin.

The heat-resistant fibers constituting the reticulated structure used in the present invention refer to fibers which do not easily melt or thermally expand even at high temperatures, and examples of the inorganic fibers include glass fibers, carbon fibers and alumina fibers. The organic fibers include aramid fibers and polyimide fibers. In any case, it is a fiber that does not substantially soften, decompose, thermally expand, or shrink at the melting point of the thermoplastic resin to be coated.

The reticulated structure used in the present invention is not particularly limited as long as it is formed into a reticulated structure using the above-mentioned heat-resistant fiber. For example, a reticulated product, an open plain woven fabric, a woven fabric Etc. can be mentioned. In addition, the intersection of the warp and the weft, such as a cross cloth, may be stitched with a binder, but in this case, the melting point of the binder is preferably sufficiently higher than the melting point of the thermoplastic resin to be coated.

The thermoplastic resin film used in the present invention is formed by molding a thermoplastic resin such as polypropylene, polyethylene or polyester into a film shape, and the thickness of the film is appropriately selected according to the desired resin adhesion amount. do it. The thermoplastic resin, which is the material of the film, does not deform the heat-resistant fiber in the subsequent step of heating and aggregating the mesh portion, and therefore has a melting point at a temperature at which the heat-resistant fiber is not substantially deformed.

In the method of the present invention, first, the thermoplastic resin film is laminated on the upper surface and the lower surface of the reticulated structure, and then a soft sheet material is superposed on the upper surface and the lower surface thereof, and then pressed from above and below. And heat. By this pressurization and heating, the thermoplastic resin films arranged above and below the mesh portion of the network structure are pressed by the soft sheet-like material, deformed, and the thermoplastic resin films are pressed against each other and fused. The fusion in the mesh portion is preferably almost the entire surface of the mesh, but at least the central portion of the mesh may be bonded.

The soft sheet material used here is not particularly limited as long as it has elasticity or flexibility that exhibits the above-mentioned effects, and for example, knitted fabric such as knitted fabric, non-woven fabric such as felt, and sheet shaped product. Heat resistant rubber etc. can be mentioned. When the softness of the sheet-like material used here is insufficient, the thermoplastic resin films arranged above and below cannot be sufficiently pressed and fused at the mesh portion.

The above-mentioned pressurizing and heating conditions may be set by appropriately setting the conditions under which the thermoplastic resin films are brought into pressure contact with each other and fused, but at least the heating temperature is not lower than the softening point of the thermoplastic resin films. When the pressurizing pressure or the heating temperature is insufficient, the thermoplastic resin films cannot be pressed and fused at the mesh portion. However, if the heating temperature is set too high, the thermoplastic resin film will shrink due to heat, which is not preferable.

The pressure and heating method may be, for example, a method in which the above materials are successively laminated and then pressed by a hot press while being heated by hot air, radiant heat, or the like, or each material in roll form is fed out by a nip roller. A method of pressing and heating with a hot roller after laminating may be mentioned, but the method is not particularly limited to these methods, and a known appropriate method may be used.

It is preferable that the thermoplastic resin film and the soft sheet-like material are easily peeled off when the pressure and heating are performed. Therefore, when the thermoplastic resin film and the soft sheet-like material are easily fixed to each other, a sheet-like material that easily separates from the melt of the thermoplastic resin film is laminated between them, or the soft sheet-like material is laminated. It is preferable to subject the surface to a release treatment.

By the pressure and heat treatment described above, a composite sheet in which the net-like structure is sandwiched and integrated by the thermoplastic resin film is obtained. Then, the obtained composite sheet is further subjected to heat treatment. The temperature in this heat treatment is a temperature at which the thermoplastic resin is sufficiently fluidized, that is, at least the melting point of the thermoplastic resin film or higher. By this heat treatment,
The thermoplastic resin film fused at the mesh portion is aggregated and shrinks toward the heat-resistant fibers forming each mesh, the thermoplastic resin film at the center portion of the mesh is removed, and a space is formed in the mesh. Then, the aggregate of the thermoplastic resin film covers the surface of the network structure.

The above-mentioned heat treatment may be carried out by a known appropriate method, but a method of directly applying hot air to the mesh is preferable because the mesh space can be quickly formed by the aggregation of the thermoplastic resin film.

[0017]

【Example】

Example 1 A net-like structure in which glass fibers are entangled and woven (the number of hammered in: 2.4 warps / m ² , weft 3.5 warps / m ² , thickness 0.9).
mm, basis weight 390 g / m ² ) thickness 50 on top and bottom
A polypropylene (PP) film with a μm and a melting point of 164 ° C. is laminated, and fluororesin-coated aluminum foil is further laminated on the upper and lower surfaces thereof, and the thickness of 1.3 mm on both upper and lower surfaces.
Put the cotton knitted fabrics on top of each other, set the temperature of the heat press board to 170 ° C, press and heat with a pressing force of 1 kg / cm ² for 5 minutes, and sandwich the mesh structure with PP film to form a composite sheet. Obtained. In the obtained composite sheet, the PP films arranged on the upper and lower sides were fused to each other in the mesh portion, although not on the entire surface.

Next, the obtained composite sheet was heated at 180 ° C. for 10 minutes. In the obtained sheet-like material, the PP film was aggregated to form a clean space in the mesh portion, and the fiber surface of the network structure was uniformly coated with PP.

Example 2 Polyethylene having a thickness of 130 μm and a melting point of 111 ° C. (P) was formed on the upper and lower surfaces of a net-like structure similar to that used in Example 1.
E) A film is laminated, and a heat resistant rubber sheet having a thickness of 2 mm is further laminated on the upper and lower surfaces thereof, and the temperature of the hot press machine is heated at 120 ° C. and a pressing force of 1 kg / cm ² for 10 minutes,
A composite sheet was obtained in which the mesh structure was sandwiched and integrated with the PE film. In the obtained composite sheet, the PE films arranged above and below were fused at the mesh portion.

Then, the obtained composite sheet was heated at 160 ° C. for 20 minutes. During heating, hot air at 160 ° C. was blown from the direction perpendicular to the mesh. In the obtained sheet-like material, PE was uniformly coated on the net-like structure (coating), and a clean space was formed in the mesh part.

COMPARATIVE EXAMPLE A composite sheet was prepared by pressurizing and heating in the same manner as in Example 1 except that the cotton knitted fabric used in Example 1 was not overlapped and the temperature of the hot press machine was set to 150 ° C. Obtained. In the obtained composite sheet, the PP films arranged on the upper and lower sides were fused to each other in only a small portion in the mesh portion.

The composite sheet was heated as in Example 1. In the obtained sheet-like material, the fusion between the PP films in the mesh and the fusion between the PP film and the glass fiber were insufficient, so that the PP film showed irregular heat shrinkage. In addition, the resin surface was not scattered on the fiber surface of the network structure, and the coating state was extremely uneven. Furthermore, there were some spots where a clean space was not formed in the mesh.

[0023]

EFFECTS OF THE INVENTION According to the method of the present invention, a desired amount of thermoplastic resin can be coated on a network structure made of heat resistant fibers easily and efficiently without clogging the network. Further, since the method of the present invention does not use the resin solution, it is possible to form an extremely dense coating layer without generating microvoids inside the coated resin.

[Brief description of drawings]

FIG. 1 is an exploded explanatory diagram illustrating a pressure heating step in a manufacturing method of Example 1.

FIG. 2 is an exploded explanatory diagram illustrating a pressurizing and heating step in the manufacturing method of Example 2.

FIG. 3 is an enlarged plan view showing an example of a network structure (A) to which the present invention is applied and a state (B) in which the network structure is coated with a resin by the method of the present invention.

[Explanation of symbols] 1 reticulated structure 2 thermoplastic resin film 3a cotton knit 3b heat resistant rubber sheet 4 heat press board 5 fluororesin-coated aluminum foil 11 thermoplastic resin 12 entangled woven warp 13 entangled weft 14 mesh

[Procedure amendment]

[Submission date] May 23, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 1

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to laminate a thermoplastic resin film on the upper and lower surfaces of a network structure made of heat resistant fibers, and further to laminate a soft sheet material on the upper and lower surfaces thereof. After heating under pressure, the thermoplastic resin film disposed on the upper surface of the network structure and the thermoplastic resin film disposed on the lower surface are fused at the network of the network structure, and then the melting point of the thermoplastic resin film. Heated above,
This is achieved by a resin coating method for a network structure, which comprises coagulating a thermoplastic resin film to form a space in a mesh and coating the heat- resistant fiber with the thermoplastic resin.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction content]

[0017]

Example 1 A glass fiber entangled woven net-like structure (the number of driving: warp 2.4 / 25 mm , weft 3.5 / 25 mm , thickness 0.9 mm, basis weight 390 g / m ² ). Polypropylene with a thickness of 50 μm and a melting point of 164 ° C. on the upper and lower surfaces (P
P) Laminate the film, and further stack the fluororesin-coated aluminum foil on the upper and lower surfaces of the film, and then stack 1.3 mm thick cotton knitted cloth on the upper and lower surfaces thereof,
The temperature of the hot press board is set to 170 ° C and the pressing force is 1 kg /
It was pressurized and heated at 5 cm ² for 5 minutes to obtain a composite sheet in which the network structure was sandwiched and integrated with the PP film. In the obtained composite sheet, the PP films arranged on the upper and lower sides were fused to each other in the mesh portion, although not on the entire surface.

Claims (1)

[Claims] 1. A thermoplastic resin film is laminated on an upper surface and a lower surface of a net-like structure made of heat-resistant fiber, and a soft sheet-like material is further laminated on the upper surface and the lower surface thereof and heated under pressure to form the net-like structure. After fusing the thermoplastic resin film arranged on the upper surface and the thermoplastic resin film arranged on the lower surface with the mesh of the reticulated structure, the thermoplastic resin film is heated to a temperature equal to or higher than the melting point of the thermoplastic resin film to form a thermoplastic resin film. A method for coating a resin on a reticulated structure, which comprises coagulating to form a space in the reticulated structure and coating the reticulated structure with a thermoplastic resin.