JPH0999448A - Vacuum press laminate molding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the quality of a product by reducing the blisters, wrinkles and unevenness of an outer surface caused by air between a molding base material and a decorative sheet by adding a powder with a specific particle size to the adhesive interposed between the base material and the sheet. SOLUTION: A molding base material 5 is arranged on the suction placing stand 22 provided in a chamber 21 on a base material side and the adhesive 3 preliminarily applied to the molding base material 5 and/or a decorative sheet to be held to a dry state is a heat-sensitive adhesive (e.g. acrylic emulsion) containing a powder with a particle size of 0.01-0.5mm and interposed between the molding base material 5 and the decorative sheet 1 is activated after the air between the molding base material 5 and the decorative sheet 1 is sucked and degassed to the chamber 21 to bond both of them.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum press lamination molding method suitable for adhering a decorative sheet to the outer surface of a molding substrate having a three-dimensional shape such as an automobile interior material.

[0002]

2. Description of the Related Art A method of adhering a decorative sheet to the outer surface of a molding substrate and laminating it is to divide the upper chamber and the lower chamber by a decorative sheet, pressurize the upper chamber, and lower the chamber where the molding substrate is placed. In order to bond the decorative sheet along the outer surface of the molding base material by depressurizing by vacuum suction to generate a pressure difference between them and pressurizing and softening the decorative sheet at approximately the same time. Are known.

[0003]

However, since the surface of the adhesive coated in a dry state which is previously applied to the molding substrate and / or the decorative sheet is a smooth surface, the decorative sheet and the adhesive are softened by heating. Then, slippage of the adhesive-coated surface became poor, and skill was required to set the decorative sheet on the surface of the molding substrate, and even after the setting, they did not sufficiently match.

At the time of lamination molding, the air existing between the molding substrate and the decorative sheet is not completely exhausted and often remains in the form of bubbles. There is a problem that blisters and wrinkles occur on the surface.

The problem as described above is that when the molding base material is a wood molded article having air permeability, the air remaining between the molding base material and the decorative sheet is vacuum sucked to the outside through the molding base material. It can be avoided because it can be degassed, but it cannot be avoided if the molding substrate is a synthetic resin molded product having no air permeability unless new measures are taken.

In view of the above points, the present invention is caused by air remaining between a molding base material and a decorative sheet in order to solve the above problems in a conventional vacuum press lamination molding method. It is an object of the present invention to provide a vacuum press lamination molding method capable of reducing blisters, wrinkles, irregularities, etc. on the outer surface as much as possible.

[0007]

According to the present invention, a vacuum press lamination is provided in which a molding base material is placed on a suction table provided in a base material side chamber and a decorative sheet is adhered onto the outer surface of the molding base material. In the molding method, the adhesive which is previously applied to the molding base material and / or the decorative sheet and kept in a dry state is a powder having a particle diameter of 0.01 to 0.5 mm, which is mainly composed of a thermoplastic resin or an elastomer. A heat-sensitive adhesive containing
Air existing between the molding substrate and the decorative sheet is sucked and degassed into the chamber on the substrate side, and then the above adhesive agent interposed between the molding substrate and the decorative sheet is activated to bond them. It is a vacuum press lamination molding method characterized by

In carrying out the vacuum press lamination molding method of the present invention, conventionally known vacuum press equipment can be used as it is for the basic components.

Further, the molding base material to be adhered may be a plate-like body such as a flat plate or a curved plate, or a relatively complicated three-dimensional object having an uneven portion, and the material thereof is not particularly limited. ,
It may be wood, synthetic resin, metal, ceramics, etc.,
The characteristics of the present invention are particularly three-dimensional synthetic resin molded products having no air permeability, or metal molded products, porcelain having no air permeability,
It is used for hard pottery. In this case, examples of the material of the synthetic resin molded product include ABS, polystyrene, acryl and vinyl chloride resin.

The decorative sheet includes both a transfer sheet and a sticking sheet (sticking laminated sheet) made of synthetic resin, and may be a sheet-shaped material other than resin such as a veneer.

As the thermoplastic resin which is the main component of the adhesive applied to the molding substrate or the decorative sheet, acrylic resins (polymethylmethacrylate, polyethylmethacrylate,
Polyethyl acrylate, polybutyl acrylate, etc.),
Vinyl polymer (polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl acetate copolymer, etc.), rosin ester resin (rosin, rosin-modified maleic acid resin, rosin-modified phenolic resin, polymerized rosin Etc.) and the like, which are used as an organic solvent type or a water dispersion type (emulsion type), but the emulsion type is suitable from the viewpoint of safety.

As the elastomer as the main component of the adhesive, chloroprene type, ethylene butadiene type,
There are solvent type or water dispersion type (latex type) such as nitrile rubber type, but latex type is suitable from the viewpoint of safety.

The powder mixed in the adhesive includes olefin resins (polyethylene, polypropylene, EPT).
Etc.), elastomers (natural rubber, reclaimed rubber, various synthetic rubbers, etc.), synthetic resins (melamine resin, phenol resin, urethane resin, silicone resin), inorganic fillers (glass balls, calcium carbonate, silica powder, etc.), organic fillers (Wheat flour, soybean flour, starch, etc.)
A polyolefin-based filler having a specific gravity of about 1.0 and a particle size of 0.01 to 0.5 mm is optimal in terms of quality variation and durability, and the effect of the present invention is exhibited with a particle size smaller than this. On the contrary, when the particle size is large, the finished surface becomes uneven and is not suitable. The added amount is 0.1 to 50 per 100 parts by weight of the adhesive component in terms of solid content.
Parts by weight are suitable.

Here, in the vacuum press lamination molding method according to the present invention, the heat-sensitive adhesive used for bonding the decorative sheet has a temperature at which it activates along the outer surface of the molding substrate due to the heat of the decorative sheet. It is desirable that the temperature is higher than the softening temperature (hereinafter referred to as softening temperature).

Therefore, the specific material of the adhesive is appropriately selected in relation to the material and thickness of the decorative sheet used for molding or the shape of the outer surface of the molding substrate. For example, the softening temperature of a polyvinyl chloride sheet, which is often used as a material for a decorative sheet because of its excellent moldability, is 60 to 90 ° C.
Moreover, the softening temperature of the ABS sheet is about 90 to 100 ° C., and the activation temperature of the series of heat-sensitive adhesives described above is higher than normal 100 ° C. You can select it. Further, as the adhesive, other than the heat-sensitive adhesive, an adhesive that is activated at a high frequency under conditions other than heat may be used.

In the vacuum press lamination molding method of the present invention, the time for sucking and deaerating the air existing between the molding substrate and the decorative sheet is as long as the decorative sheet is not yet adhered to the molding substrate. Well, specifically, before the decorative sheet is heat-softened, or when the decorative sheet is heat-softened but the adhesive layer is below the activation temperature. In the present invention, the adhesive is activated after suction and deaeration between the molding substrate and the decorative sheet. In that case, the decorative sheet is heated and softened so as to follow the outer surface of the molding substrate. It is more preferable to activate the adhesive after it is brought into close contact with.

[0017]

In the vacuum press lamination molding method according to the present invention, the powder having the above-mentioned specific particle diameter is mixed in the adhesive which is applied to the molding substrate and / or the decorative sheet and is in a dry state. Adhesive coated surface has a fine uneven surface, and when sucking and deaerating the air existing between the molding base material and the decorative sheet, it functions as a ventilation hole and does not mix conventional powder Compared to the surface, the air existing between the molding base material and the decorative sheet is reliably and completely excluded, and is less likely to remain there. As a result, the blisters and wrinkles on the outer surface, which are caused by the air remaining between the molding base material and the decorative sheet, are significantly reduced, and the quality of the molded product obtained without the uneven surface is improved. To do.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A description will be given below with reference to the accompanying drawings. FIG. 1 is a main part of an example of a vacuum press lamination molding apparatus used for carrying out the method of the present invention, showing a schematic configuration diagram before setting a decorative sheet on a molding substrate, and FIG. Fig. 1 shows a schematic configuration diagram after setting the decorative sheet.

The substrate-side chamber 21 has a box-shaped opening at the upper side, and a plate-shaped suction table 22 having a large number of through holes 23 formed in a predetermined arrangement state is attached to the upper opening. A supply / exhaust port 26 for supplying / exhausting air to / from the chamber 21 is formed on the side surface of the chamber. Further, a base material mounting base 6 for supporting and fixing the molding base material 5 during the lamination molding is attached to the central portion on the upper surface side of the suction mounting base 22. The mounting table 6 is
Although it can be omitted, it is preferable to use the mounting table 6 in order to extend the decorative sheet to the side surface of the molding substrate 5 and even part of the back surface. In this case, the mounting table having a width narrower than that of the molding substrate 5. Is preferably used.

Although not shown, the supply / discharge ports 16 and 26 are adapted to be selectively connected to a compressor and a vacuum pump via three-way switching valves, respectively.
If necessary, the inside of the seat side chamber 11 and the base material side chamber 21 can be depressurized or pressurized from the state of being open to the atmosphere, or can be maintained at a constant pressure.

It should be noted that this device is merely an example, and essentially all vacuum press lamination molding devices conventionally known in the present invention can be used as they are. Next, a procedure for carrying out the vacuum press laminating method according to the present invention will be described.

First, as shown in FIG. 1, a molding base 5 made of synthetic resin having a three-dimensional shape is positioned and installed on a base mounting table 6, and the molding base 5 serves as an adhesive surface. The adhesive 3 of Example 1 and Comparative Example 1 having the composition shown in Table 1 is applied to the surface of the above-mentioned surface to form a dry film.

When the other adherend, that is, the decorative sheet 1 is set, the heater 15 does not generate heat yet, the temperature of the decorative sheet 1 is maintained at about room temperature, and the base material side chamber 21. The suction of the air inside is started. Next, the seat side chamber 11 is lowered, and the heater 15 is caused to generate heat in this state.
Pressurized air is supplied to the seat side chamber 11 to increase the internal pressure. As a result, the decorative sheet 1 is heated and softened. However, at this time, the decorative sheet 1 is softened but does not completely follow the outer surface of the molding substrate 5, and the temperature (Ts) of the decorative sheet 1 is equal to or higher than the softening temperature of the decorative sheet 1, but the adhesive 3 Below the activation temperature of. Then, in such a state, in the substrate-side chamber 21 and
It exists in a sealed space surrounded by the side peripheral portions of the molding substrate 5 and the substrate mounting table 6, the upper surface of the suction table 22, and a space surrounded by the upper surface of the molding substrate 5 and the decorative sheet 1. Degas by aspirating air completely. As a result, as shown in FIG.
The entire decorative sheet 1 comes into close contact with the adhesive-coated surface of the molding substrate 5. After that, the temperature (Ts) of the decorative sheet 1 changes to the adhesive layer 3
When the heat generation operation of the heater 15 is continued so as to reach the activation temperature or above and the adhesive layer 3 is activated, the entire decorative sheet 1 is adhered to the outer surface of the molding substrate 5 in a close contact state.

After the adhesion of the decorative sheet 1 is completed in this manner, the heat generation operation of the heater 15 is stopped before the melting point of the decorative sheet 1 is reached, and the sheet-side chamber 11 and the substrate-side chamber 21 are in the atmosphere. The sheet-side chamber 11 is raised, and the laminated molded product in which the decorative sheet 1 is bonded to the molding substrate 5 is taken out.

Occurrence of blisters, wrinkles and the like and the presence or absence of surface irregularities were visually measured on the outer surface of the taken out laminated molded product, and the results are shown in Table 1.

[0026]

[Table 1]

[0027]

As described above, in the vacuum press lamination molding method according to the present invention, since the adhesive agent interposed between the molding substrate and the decorative sheet contains the powder having a specific particle diameter,
Air existing between the molding substrate and the decorative sheet is reliably and completely removed, and no wrinkles, swelling or unevenness appears on the surface after lamination.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a main part of an example of a vacuum press lamination molding apparatus used when carrying out a method of the present invention before setting a decorative sheet on a molding substrate.

FIG. 2 is a schematic configuration diagram of a main part of an example of a vacuum press lamination molding apparatus used for carrying out the method of the present invention after setting a decorative sheet on a molding substrate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Decorative sheet 3 Adhesive 5 Molding base material 6 Base material mounting table 10 Vacuum press lamination molding apparatus 11 Sheet side chamber 12 Cylinder device 16 Supply / discharge port 21 Base material side chamber 22 Suction table 23 Through hole 26 Supply / discharge port

Claims (1)

[Claims] 1. A vacuum press laminate molding method in which a molding substrate is placed on a suction table provided in a substrate chamber, and a decorative sheet is adhered to the outer surface of the molding substrate. / Or a decorative sheet, an adhesive which is applied in advance and dried is a heat-sensitive adhesive containing a thermoplastic resin or an elastomer as a main component and a powder having a particle diameter of 0.01 to 0.5 mm, After sucking and deaerating the air existing between the molding base material and the decorative sheet into the base material side chamber,
A vacuum press lamination molding method comprising activating the above-mentioned adhesive agent interposed between a molding substrate and a decorative sheet to bond them together.