JPS6135913A - Decoration of molded product - Google Patents

Abstract

PURPOSE:To present three-dimensional deep marble pattern on a molded part by a method wherein liquid polymerizable substance and colored composition respectively blended with fillers, the specific weights of which are different from each other, are mixed. CONSTITUTION:Base material composition is obtained by adding polymerization initiator and aluminium hydroxide having mean particle diameter of 4mum (specific weight 2.4) to monomeric mixture consisting in dissolving polymethyl methacrylate in methyl methacrylate and mixing them and deaerating the resultant mixture. Colored composition is obtained by adding polymerization initiator, alumina having mean particle diameter of 4mum (specific weight 3.98) and coloring agent (phthalocyanine green or carbon black) to said monomeric mixture and completely mixing them and deaerating the resultant mixture. The obtained base material composition and colored composition are mixed together and poured in a casting mold and hardened by heating. The deep marble pattern, the green pattern of which is formed in the interior of a molded product, is presented on the obtained molded part.

Description

[Detailed Description of the Invention] This invention relates to a method for patterning a molded product, and more specifically, a method for patterning a molded product so that the pattern is not limited to the surface of the molded product, but extends to the inside, and has a three-dimensional depth. Regarding.

Conventionally, methods for adding patterns to molded products by cast molding include placing printed paper or printed nonwoven fabric on the inside of the mold during molding, and adding patterns at the same time as casting.
After molding, there are methods such as direct printing or thermal transfer on the surface of the molded product.

Patterning by these methods only provides a flat, depthless, and cheap-looking product because the pattern is only on the surface of the molded product.

In addition, as a method for patterning the inside of a molded product, a base material composition and a patterning composition of several colors different from this composition are mixed so as not to be completely uniform. There is a method of injecting it into a mold and allowing it to polymerize and harden. In this method, the coloring composition used for patterning is dispersed throughout the molded product, so the pattern is applied to areas that do not require patterning, such as the opposite side of the used surface or the inner layer, and the pattern on the surface of the molded product. There were problems such as a low percentage of

This invention was made by paying attention to the above-mentioned problems.

The purpose is to make the pattern reach the inside of the molded product to give it a deep appearance, and the density of the colored pattern increases as it gets closer to the surface of use.

The purpose of this invention is to propose a method that can effectively form patterns near the surface.

The gist of the present invention is to inject a base composition containing a liquid polymerizable substance and a coloring composition into a mold, polymerize and harden the mixture in a state in which the two are mixed uniformly, and apply a pattern to a molded product. A coloring composition is characterized in that a filler having a higher specific gravity or a filler having a lower specific gravity than both the liquid polymerizable substance of the base composition and the filler blended in the base composition is blended. Patterning molded products is a method.

Molded articles patterned by this method have a pattern formed by non-uniform mixing of the base composition and the coloring composition, which is created by the difference in specific gravity of the filler in the coloring composition during the polymerization process. Since it can be transferred to the surface, a colored pattern with high density can be formed on the surface layer of the molded product.

In other words, if the filler added to the coloring composition has a higher specific gravity than both the liquid polymerizable substance and the filler in the base composition, the filler in the coloring composition will be absorbed during the polymerization and curing process of the composition. The agent sediments, and along with this sedimentation, a portion of the coloring composition also sediments, so that the pattern density near the surface of the lower die of the mold becomes high. Therefore, by designing the entire mold so that the lower mold side is the working surface, the colored pattern is dense near the working surface of the molded product, and the pattern extends not only to the surface but also to the inside, creating a three-dimensional and deep pattern. A molded article having the following properties is obtained.

In addition, if the filler blended into the coloring composition has a smaller specific gravity than either the liquid polymerizable substance or the filler in the base composition, the above case will be reversed, and a part of the coloring composition will be It migrates to the vicinity of the surface of the upper mold. Therefore, by designing the mold so that the upper mold is used as the surface to be used, it is possible to provide a three-dimensional and deep pattern as described above.

The base composition and coloring composition used in this method contain a liquid polymerizable substance as a main component.

This liquid polymerizable substance is a liquid monomer that undergoes addition polymerization at room temperature or by heating, or a monomer solution (so-called Shirabu) of a polymer dissolved in a liquid monomer that can undergo addition polymerization.
It is. In addition, fillers are blended in both groups of acids, and in the case of base material compositions, the blending amount is usually 10 to 85% by weight.
A polymerization initiator is added as necessary.

In addition, it is preferable to use a monomer solution of the same monomer or the same polymer as the liquid polymerizable substance of the coloring composition and the base material composition.

The filler blended into the coloring composition settles or floats under the control of the factors in the Stokes equation, such as specific gravity, particle size, viscosity, etc. In addition, the amount of filler blended or the polymerization rate of the composition is also greatly affected. That is, if it is desired to increase the amount of movement, the specific gravity difference and particle size may be increased, the viscosity of the liquid polymerizable substance of the base material composition may be reduced, the amount of filler blended may be reduced, and the polymerization rate may be slowed down. however,
In order to achieve the effects of the present invention, it is preferable that the difference in specific gravity of the filler blended into the coloring composition with respect to the liquid polymerizable substance of the base composition and the filler is at least 0.5.

When the coloring composition is added to the base composition, it is required to have an appropriate viscosity so that it does not easily diffuse and mix uniformly. It is desired that the temperature at the time of normal mixing is 5 poise or more, preferably 30 poise or more, and more preferably 60 poise or more. At the same time, in order to reduce the tendency of the filler blended in the coloring composition to settle or float during polymerization and separate, the viscosity of the liquid polymerizable substance is preferably 20 centipoise or more at the mixing temperature. It is desirable that the number is 1 voice or more. For this reason, as the liquid polymerizable substance of the coloring composition, it is preferable to use a highly viscous solution of a polymer dissolved in a monomer, that is, a sillage.

A relatively high viscosity coloring composition made by blending fillers and colorants with such a sillage forms a lump that does not easily spread when added to a base composition, and can be mixed non-uniformly. . In order to cause the lumps of the coloring composition to settle or float at an appropriate rate in the base material composition in this state, the apparent specific gravity of the coloring composition must be such that the difference in specific gravity between the coloring composition and the liquid polymerizable substance of the base material composition is It is desirable that it be 0.2 or more, more preferably 0.5 or more. (The apparent specific gravity here is the value obtained by dividing the weight of the composition by its volume.) The coloring composition with such an apparent specific gravity has a higher apparent specific gravity than both the liquid polymerizable substance and the filler in the base composition. It can be made by blending a filler with a high specific gravity or a filler with a low specific gravity.

The addition polymerizable vine monomer used in this invention includes:
Methyl acrylate, ethyl acrylate, n-acrylate
Acrylic acid alkyl esters such as propyl, n-butyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, methacrylic acid alkyl ester, 2-hydroxyethyl acrylate, 2-methacrylic acid Examples include hydroxyethyl, acrylonitrile, styrene, and vinyl acetate.

Examples of the polymer that can be dissolved in the monomer include vinyl polymers obtained by polymerizing or copolymerizing the above-mentioned monomers, saturated or unsaturated polyester resins, and epoxy resins.

Examples of the filler include calcium carbonate, calcium sulfate, quartz, glass powder, aluminum hydroxide, magnesium hydroxide, aluminum silicate, barium talc carbonate, barium sulfate, zircon, alumina, shirasu balloon, silica balloon, and the like.

Polymerization initiators include azo- or peroxide-containing compounds, such as 2,2'-azobisisobutyronitrile, benzoyl peroxide, lauroyl peroxide, diisopropyl peroxydicarbonate, etc. Sixth class amines may be added.

The coloring agent is a dye or pigment that is dissolved or dispersed in the monomer mixture to be subjected to addition polymerization, and specifically,
These include alizarin yellow, palatine chrome brown, anthraquinone violet, methylene blue, titanium white, carbon black, cadmium yellow, iron oxide, phthalonanine pigments, quinacridone pigments, and dioxazine pigments.

In addition, in this invention, a filler having a refractive index similar to the optical refractive index of a polymer obtained by polymerizing the liquid polymerizable substances of the base composition and the coloring composition is added to the base composition in an amount of 10 to 10%.
When blended in an amount of 85% by weight, appropriate hiding properties and transparency can be imparted to the obtained molded product. Therefore, this molded product exhibits a deep appearance similar to natural marble due to the interaction of the three-dimensional pattern, appropriate hiding power, and transparency.

Example 1 1 kg of a monomer mixture prepared by dissolving 100 t of polymethyl methacrylate with an average molecular weight of i o o, o o o in 900 t of methyl methacrylate was added with 2,2 as a polymerization initiator.
- 5f of azobis(4-methoxy-2,4-dimethylvaleronitrile) and aluminum hydroxide (with an average particle size of 4μ)
Specific gravity: 2.4) 2Kp was added, thoroughly mixed and defoamed to obtain a base material composition.

The coloring composition consists of polymethyl methacrylate (100F) with an average molecular weight of ioo, ooo and methyl methacrylate (400F).
To 500 g of the monomer mixture dissolved in 1F, 2.52 g of 2,2-azobis(4-methoxy-2,4-dimethylvaleronitrile) as a polymerization initiator, and alumina with an average particle size of 4 μm (specific gravity; 5. 98) 4, phthalocyanine green 0.07S', and carbon black 0.029 were added to 1, mixed well, and defoamed to obtain a colored composition.

The base composition and coloring composition described above were poured into a polyethylene container and lightly stirred to obtain a non-uniformly mixed composition.

Furthermore, a cast mold with a mold release agent applied to the inner surface was placed with the surface to be used facing downward, and after pouring the unevenly mixed composition into the mold, the mold was sealed and soaked in hot water at 50°C. It was heated and cured for about 6 hours.

The molded product removed from the mold is placed in a heating oven for 11 days.
After-cure was performed at 0°C for 3 hours.

The molded product obtained had a deep green pattern with a high density on the side to be used, almost no pattern on the opposite side, and was marble-like with a deep pattern.

Example 2 2,2-azobis(4-methoxy-2゜4-dimethylvaleronitrile) was added as a polymerization initiator to 500f of a monomer mixture in which 100g of polymethyl methacrylate having an average molecular weight of 100,000 was dissolved in methyl methacrylate 4002. 2.59. Silica balloon with an average particle size of 65μ (specific gravity: 0.21) 150F, and phthalocyanine green 0.07? , 0.02 t of carbon black was added, mixed well, and defoamed to obtain a colored composition.

This colored composition and the base material composition obtained in Example 1 were poured into a polyethylene container and lightly stirred to obtain a non-uniformly mixed composition.

After pouring the unevenly mixed composition into a casting mold whose inner surface is coated with a release agent and placed with the surface to be used facing upward, it is sealed and soaked in warm water at 50°C for about 3 hours. Heat and harden.

The molded product removed from the mold is placed in a heating oven for 11 days.
After-cure was performed at 0°C for 3 hours.

The molded product obtained had a deep green pattern with a high density on the side to be used, almost no pattern on the opposite side, and was marble-like with a deep pattern.

This invention is as described above, and this method makes it possible to efficiently apply a deep three-dimensional pattern extending from the surface to the inside of a molded product obtained by cast molding near the surface of use. .

Claims (1)

[Claims] (1) A method in which a base composition containing a liquid polymerizable substance and a coloring composition are injected into a mold, and the two are polymerized and cured in a state in which they are mixed uniformly to form a pattern on a molded product. A molded article containing a filler having a higher specific gravity or a filler having a lower specific gravity than both the liquid polymerizable substance of the base composition and the filler blended in the base composition. Patterning method.