JPS5917663B2 - Method for producing decorative material with composite foam decorative pattern surface - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a decorative material having a composite foam decorative pattern surface on which a foam layer is formed by several-order foaming.

In order to compensate for the monotony of the decorative surface due to a mere printed pattern, it has been conventionally practiced to create a pattern of an appropriate shape on the surface of the base material by foaming.

For example, by laminating a Netsumachi plastic sheet containing a foaming agent on the surface of a base material, and strongly foaming the part of the sheet surface where a pattern has been printed with printing ink containing a foaming accelerator, a foamed decorative surface can be created. There is a method that forms a 5j raised pattern (Japanese Patent Publication No. 43-15713), and the pattern is similarly printed on a foamed resin coating using a printing ink containing a foaming promoter, but at this time, the foaming promoter does not adhere. A device that changes the degree of foaming in the pattern printed area by making the amount of foaming different and foaming more than in the normal area (Special Publication Publication No. 46-1)
No. 3929) is also available.

In addition, a pattern is printed directly on the surface of the base material using a printing ink containing amine substances, and then a top coat is applied on top of the pattern using a synthetic resin mixed with an acid, resulting in a large amount of amine substances being mixed with the acid. There is a method (Japanese Patent Laid-Open No. 48-99266) that forms a bubble pattern in a synthetic resin coating using gas. Each of these forms a raised foam layer by applying a foaming agent or accelerator to the resin on the surface decorative material using a special method; At first glance, it appears to be a paint pattern, as it is simply a relatively smooth raised pattern, and it is nothing more than a poor design.

In the present invention, without using a special foaming agent or without using a special application means, a pattern portion formed by applying a foaming agent-containing resin to the surface of a base material is foamed in several steps. The purpose of this invention is to provide a method for manufacturing a decorative material that forms a foam pattern with a unique texture in which foam cells protrude on the decorative surface; After forming a pattern by applying a thermoplastic resin mixed with a foaming agent to the surface of the foaming agent, primary heating is performed at a temperature higher than the decomposition temperature of the foaming agent to foam the surface layer of the applied resin, This surface foam layer is then solidified, and the lower coated resin layer is heated and foamed in the same manner. .

That is, in the present invention, when heat-treating the patterned portion formed by coating the foaming agent-containing resin on the surface of the base material; This is done by foaming and fixing in stages. This stepwise foaming involves first foaming and solidifying the foaming agent located on the surface of the resin that has been primarily applied to the surface of the base material, and then foaming the foaming agent located inside the resin in stages. made by. By the first heat foaming,
Numerous bubbles protruding from the surface of the decorative layer are formed, and the second and subsequent heat foaming treatments complement the surface shape and form a foam layer below to swell the surface layer. Thus, depending on how the decorative surface is designed, a gorgeous loop embroidery-like pattern or a satin-like coating can be formed on the surface of the decorative material. Hereinafter, the present invention will be explained based on the illustrated embodiments.

FIG. 1 is a diagram showing a cross section, where 1 is a base material, 2 is a printed pattern made of resin mixed with a foaming agent, and 3, 3! ,31
... is a foaming agent mixed in the resin of the printed pattern, 3a, 3
b, 3c, 3a', 3a''''... are foams after the blowing agent has been decomposed, and 4 is a foamed decorative layer.

As the base material 1, an appropriate one can be used among various plate-like materials such as plywood, hardboard, particle board, gypsum board, asbestos cement board, and iron plate, or sheet materials such as paper and cloth. In addition, in order to form a pattern on the base material, especially in the case of a plate-like object, filler, sealer, etc. are applied to the base material surface.
It is preferable to form the base 5 by performing a base treatment such as undercoating, or by pasting paper, cloth, vinyl sheet, etc. A synthetic resin ink or paint containing a foaming agent is applied onto the base material 1 .

In the illustrated embodiment, a partial cross section of a pattern 2 formed using a synthetic resin ink containing this foaming agent is shown. The blowing agents 3, 3″, 3″, etc. used here are as follows:
There are dinitrosopentamethylenetetramine (DPT), azodicarbonamide (AZC), para-toluenesulfonyl hydrazide (TSH), etc., and the resins include polyvinyl chloride (PVC), polypropylene (PP), polyethylene (PE), Ethylene vinyl acetate copolymer (E
Thermoplastic resins such as VA) and polystyrene (PS) are used.

Further, pattern printing using the foaming agent-containing resin can be performed using a gravure offset printing machine, a silk screen printing machine, a letterpress printing machine, or the like. The base material 1 on which the pattern 2 is printed in this manner is heat-treated using an infrared drying oven or the like. In this case, pattern 2 is heat treated several times to ensure that all the blowing agents present in the printed pattern on the substrate do not decompose at the same time.

If the foaming agent-containing resin were heated and foamed at the same time without dividing it into several batches, the entire resin would become plasticized at the same time.
The result is a simple foaming pattern that is no different from the conventional foam pattern. In the present invention, the first
The second heat treatment is performed to decompose only the foaming agent 3 located near the surface of the pattern-applied resin.

The foaming agent decomposed by this heating gasifies, and the resin layer is easily deformed at the surface layer by the pressure of the generated gas.
Spherical bubbles 3c are formed on the surface, and as the bubbles grow, the sides of the spherical bubbles 3c come into contact with each other. The growth develops to form dome-shaped bubbles 3b, and as this state progresses further, protruding-shaped bubbles 3a are formed and stand in a forest. The first finishing treatment is stopped before the pressure of the generated gas exceeds the surface tension of the thermoplastic resin and before the blowing agent 3'' located below starts to decompose.

When this heating is stopped, the bubbles 3a protruding from the resin surface solidify and maintain their original shape. After the foam 3a generated by the primary heating is solidified, secondary heating is similarly performed to decompose the foaming agent 3'' in the internal portion that was not foamed during the primary heating.

Bubbles 3a formed by primary heating during secondary heating
The content per unit volume of the plasticizer mixed in the resin forming the foam 3a decreases due to foaming of the resin, resulting in a decrease in plasticizing ability, and even after secondary heating, the unfoamed portion remains. The plasticization is slower than that of the resin, and even if bubbles 3''a are formed by secondary heating, plasticization does not proceed and the form is sufficiently maintained.Cubs 3 formed by secondary heating
``a'' pushes up the bubbles 3a formed by the primary heating from below, and also cuts in between the bubbles 3a, 3a, so that they are slightly exposed on the surface.Then, the secondary heating is completed, and the secondary foamed portions are also exposed. In this way, further heat treatment is performed if necessary, so that all of the foamed resin 2 coated on the base material 1 is foamed, and the foamed resin 2 formed by the primary foaming treatment is characterized by air bubbles 3a;
A special foam pattern 4 is formed by being raised by the secondary foaming process. Note that during several heat treatments, the foamed resin may be actively cooled, in which case the base material is alternately conveyed between the drying oven and the cooling oven by a belt conveyor. Alternatively, this can be done by alternately operating an infrared lamp and a cooling fan.

In addition, by mixing and using foaming agents with different decomposition and foaming temperatures, volatile solvent-type foaming agents, inorganic foaming agents, etc. as foaming agents added to thermoplastic resins, the foaming process can be made different, resulting in even more change. It is also possible to express a certain foam pattern. As described above, according to the present invention,
Without using special foaming agents or foaming aids, it is possible to form a foam pattern with protruding bubbles, and the overall pattern is full of three-dimensionality and rich in variety, creating a pattern similar to heavy loop embroidery such as floral patterns. Alternatively, it is possible to obtain a decorative surface material with a pattern having a satin-like texture.

Example A 3-fly plywood board measuring 606 mm in width and 2430 mm in length with jointed edges was used as the base material, and after pasting a coarse cloth lined with paper on its surface, A floral pattern was printed using an ink containing an azobis foaming agent added to ethylene vinyl acetate emulsion using a gravure printing machine.

The base material was fed into an infrared heating furnace to a temperature of 120°C to 140°C.
After heat treatment for 30 seconds at a temperature of .degree. C., the sample was immediately taken out and allowed to cool.

During this 30 seconds of heating, many foams were formed protruding from the surface of the floral pattern. Then, the heat treatment was repeated five times under the same conditions. The obtained decorative material had a loop embroidery-like foam pattern with a large number of bubbles protruding from the surface of the foam pattern.

[Brief explanation of the drawing]

Figures 1A to 2 are schematic diagrams of the bubble generation process, and Figure 1A shows a vertical cross section of a partially broken substrate with a pattern printed with foaming agent-containing ink. C shows a longitudinal cross section of the state after secondary heating, C shows a longitudinal cross section of the foam pattern formed in the final heating step. Description of symbols, 1...Base material, 2...Resin mixed with foaming agent, 3, 3'', 3...Blowing agent, 3a,
3b, 3c, 3a'', 3a...Bubble, 4.
...Foam makeup layer, 5...Base.

Claims (1)

[Claims] 1. After forming a pattern by adhering a thermoplastic resin mixed with a foaming agent to the surface of the base material as appropriate, primary heating is performed at a temperature higher than the decomposition temperature of the foaming agent to foam the surface layer of the applied resin. A method for producing a decorative material having a composite foam decorative pattern surface with a foam layer formed on the surface, the method comprising: solidifying the foamed surface layer; and subsequently heating and foaming the lower layer of the applied resin in the same manner.