JPS6129787B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a method for quickly and economically forming a sandy pattern on the surface of a plate to be coated.

Traditionally, in factory painting, the method of applying a sand-like pattern (resin finish) to a molded board is as follows: (1) Paint mixed with granular aggregate, which is used at general building construction sites, is applied with a spray gun, etc. Method of coating the molded board using a roller coater and drying by heating. There is a method of further applying a paint on top of the coating using a flow coater and drying it by heating.

However, in method (1), not only the thickness of the coating film becomes larger than necessary, but also the yield of the coating material is poor and there are economical drawbacks. Method (2) had a defect in that it required a large number of steps and required labor to maintain and manage the equipment. Furthermore, in conventional methods, the paint must be heated and dried in order to solidify or harden, and large amounts of organic solvents contained in the paint can volatilize into the atmosphere, causing odor and air pollution. There was a possibility.

The present invention is a method invented to eliminate the above-mentioned drawbacks, and can provide a method for forming a sand-like pattern at low cost and with greatly improved productivity.

That is, in the present invention, granular aggregate coated with a hot melt adhesive is spread on a plate to be painted, and then heated, and the granular aggregate is fixed to the surface of the plate to be painted by melting the hot melt adhesive. This method of forming a sand-like pattern is characterized by: scattering granular aggregate coated with a hot melt adhesive onto an already heated plate to be coated; This is a method for forming a sand-like pattern, which is characterized by fixing it to the surface of a plate to be coated.

The basic structure of the present invention is a plywood board, a magnesium carbonate board, a calcium silicate board, a calcium carbonate board,
It concerns a method for quickly and economically applying a sand-like pattern (resin finish) to molded boards used for the interior and exterior of buildings, such as asbestos cement boards and wood chip cement boards, and the important component is the evaporation of organic solvents. The use of granular aggregate coated with a colored or transparent hot melt adhesive that does not contain volatile components or evaporable components such as water, and the use of granular aggregate coated with a colored or transparent hot melt adhesive that does not contain volatile components or evaporative components such as water; The heating process melts the hot melt adhesive coated on the granular aggregate, and the molten hot melt adhesive adheres the granular aggregate to the surface of the plate to be coated to form a sand-like pattern.

The method of the present invention will now be described in detail.

The granular aggregate is not limited, but can be used, such as cold water sand, silica sand, pulverized products of various minerals, and pulverized products of synthetic aggregate ceramics. Of course, it is also possible to mix and use two or more of the above. Moreover, the size, shape, and particle size distribution are not limited either.

The hot melt adhesive may be made of only a thermoplastic resin, but other modifiers such as a tackifying resin, a softener, an inorganic filler, a coloring agent, a stabilizer, and the like are used as additives.

Thermoplastic resins include polyurethane resins, polyamide resins, vinyl acetate resins, acrylic resins, epoxy resins, synthetic rubber resins, vinyl chloride resins, olefin resins, polyester resins, and copolymerization of two or more of these resins. Even if it is a thing,
No problem.

Tackifying resins include coumarone resin, indene resin, polyterpene resin, rosin, petroleum resin,
Styrene resin, etc., and softeners include phthalate esters, phosphate esters, paraffin, etc.

Examples of inorganic fillers include titanium oxide, zinc white, magnesium oxide, aluminum hydroxide, calcium carbonate, and silica powder.

These examples are not intended to limit the invention. Moreover, the above-mentioned ones can be used alone or as a mixture of two or more.

The melting point of the hot melt adhesive used in the method of the present invention is not particularly limited, but preferably
A temperature of 50℃ or higher is best. At temperatures below 50°C, there is a risk that the sand-like pattern on the processed plate to be coated may undergo thermal deformation under normal usage conditions.

The plate to be coated may be of any type as long as it does not denature or deform at the melting point temperature of the hot melt resin material. Examples include plywood, gypsum board, asbestos cement board, particle board, plastic board, fiberboard, magnesium carbonate board, calcium carbonate board, calcium silicate board, wood chip cement board, and the like.

The method of compounding hot melt adhesive is to perform hot melt stirring mixing using an extruder etc., but the method of coating it on granular aggregate is after mixing the granular aggregate and hot melt adhesive by melting and stirring. By introducing the hot melt adhesive into the rotary kiln and adjusting the temperature near the outlet to below the softening point temperature of the hot melt adhesive, the holding temperature will be lowered and it will be possible to obtain aggregates that are evenly adhered around each grain of granular aggregate. can.

Another method for attaching hot melt adhesive around granular aggregate is to mix and coexist the granular aggregate and hot melt adhesive, melt the hot melt adhesive by heating, and then cool the granular aggregate. The process involves producing a lump of hot melt adhesive, pulverizing the lump to a suitable particle size, and then classifying it to a predetermined particle size.

The method of dispersing the granular aggregate onto the plate to be coated is by using a vibrating sieve or by rotating the hopper at the bottom of the hopper for receiving the granular aggregate along the bottom opening surface. It is also possible to use a device equipped with a perforated cylinder with a large number of through holes.

If the surface temperature of the plate to be coated is preheated to a temperature higher than the melting point of the coated hot melt adhesive (preferably at least 10°C higher than that) when the granular aggregate is spread, the sandy pattern will be removed. It is completed at the same time as the spraying is finished, but if the surface temperature of the plate to be coated is below that temperature, a heating step is required after the granular aggregate is spread.

The furnace conditions for this heating are mainly determined by the heating time and heating temperature, and it is necessary to provide the necessary thermal energy to melt the hot melt adhesive coated on the granular aggregate.

This will be explained in detail using an example.

Example 1 50 parts by weight of ethylene vinyl acetate resin, 20 parts by weight of Coumaron resin, 10 parts by weight of titanium oxide, and 20 parts by weight of calcium carbonate were sufficiently stirred and mixed in a blender and then heated and melted and kneaded using a booster.

Put 100 parts by weight of the kneaded product into a hot blender, and add 200 parts by weight of the 5th ring of Kansuiseki into the mixture and heat to melt and stir. Before it gets cold, it is put into a rotary kiln and left there for 30 minutes. The rotary kiln is set at an inlet temperature of 250°C and an outlet temperature of 30°C.

Next, the above granular aggregate was spread on an asbestos slate board with a thickness of 9 m/m using a vibrating sieve, and then heated at 150°C for 5 minutes using a hot air circulation dryer and then taken out. A decorative board with a pattern could be obtained.

Example 2 60 parts by weight of polyamide resin, 30 parts by weight of petroleum resin,
After sufficiently stirring and mixing 10 parts by weight of paraffin in a blender, the mixture is heated and melted and kneaded using an extruder.

Put 100 parts by weight of the kneaded product into a hot blender, add 200 parts by weight of No. 3 silica sand, melt and stir while heating, and while the mixture is still cool, put it into a rotary kiln and leave it there for 30 minutes. The rotary kiln has an inlet temperature of 250℃ and an outlet temperature of 30℃.
It is set to .

Next, the above granular aggregate was spread using a vibrating sieve onto a calcium silicate board whose surface temperature had been preheated to 110°C, and then allowed to cool naturally, yielding a decorative board with a ricin pattern. Ta.

Claims (1)

[Claims] 1. Sprinkling granular aggregate coated with a hot melt adhesive onto a plate to be coated and then heating it;
A method for forming a sand-like pattern, which comprises fixing the granular aggregate to the surface of a plate to be painted by melting a hot melt adhesive. 2 Spreading the granular aggregate coated with hot melt adhesive onto the already heated plate to be coated,
A method for forming a sand-like pattern, which comprises fixing the granular aggregate to the surface of a plate to be painted by melting a hot melt adhesive.