JPS6145960B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention involves printing on a foamable resin composition using an ink containing a foaming inhibitor, and then applying a transparent resin layer thereon and heating and foaming it to create unevenness that matches the pattern. The present invention relates to a method for producing a surface-covered foam having a surface, in which unevenness is formed on the surface of the foam and at the same time, a difference in gloss is imparted thereto.

Conventionally, in order to coat the surface of such foams, many thermoplastic resin compositions such as polyvinyl chloride plastisol have been coated uniformly, but it has not been possible to provide a difference in gloss that matches the irregularities. I couldn't do it.

This invention was made in view of the above points, and uses a thermoplastic resin such as vinyl chloride plastisol containing an organic tin compound as a transparent resin layer.
This method takes advantage of the phenomenon that when an ink containing a sulfur compound is used as a foaming inhibitor, the surface gloss of the transparent coating layer, which forms concave portions during foaming, is significantly reduced. This method has been proposed in the past, such as a mechanical post-embossing method tailored to the irregularities, or a method of applying resin compositions with different glosses by printing or other methods onto the transparent layer on the concave or convex portions. Compared to conventional methods, there is no need for post-processing, the manufacturing conditions are the same as for conventional products, and the properties of the product's surface hardly change. It has outstanding effects.

This will be explained below based on the drawings.

Figure 1 shows the state before foaming, and Figure 2 shows the state after foaming. First, as shown in Figure 1, foamable resin layer 2 is coated on base material 1 to a thickness of 50 to 1000μ, and after film formation, Printing is carried out in the usual manner using normal ink 3 and suppression ink 5. In this case, the usual ink 3 can be omitted if necessary. 20 layers of transparent resin layer 4 on top of this
Apply to a thickness of ~150μ.

Next, this is heated and foamed, and then cooled to form an uneven shape as shown in FIG. In other words, the portion of normal ink 3 is sufficiently foamed to form convex portions 7, and the portion of suppressed ink 5 is suppressed from foaming to form concave portions 6.
becomes. At this time, the surface of the concave portion 6 has significantly less gloss than the surface of the convex portion 7, and this difference in gloss has the effect of significantly emphasizing the unevenness of the surface. The reason for this effect is not clear, but it is believed that sulfur compounds that decompose or sublimate during heating promote the leaching of organotin compounds to the surface, which causes a difference in surface gloss when it cools and solidifies. Guessed.

The base material may be paper, plastic sheet, plastic film, inorganic board, inorganic sheet, metal plate, metal sheet, wood base material, or any other material that has the heat resistance required during the process, and is suitable for the product. It may be a part of the material, or it may be used simply as a support during the process, such as a release paper or a metal belt.

For the foamable resin layer, a thermoplastic resin composition (preferably vinyl chloride plastisol) containing an organic blowing agent such as azodicarbonamide is coated by any method such as knife coating, roll coating, reverse roll coating, curtain flow coating, etc. Any material may be used as long as it is applied onto a base material and heated to form a film to the extent necessary for the next printing or transfer process.

Ordinary ink has wettability and adhesion with the foamed resin layer, so it only needs to have the properties required for the final product (light resistance, etc.), and the application methods include gravure, offset, and gravure offset. Any printing method such as , screen, letterpress etc. can be applied. (Preferably vinyl chloride ink and gravure printing method) The transparent resin layer is preferably vinyl chloride plastisol, but a thermoplastic resin layer that has the necessary surface protection performance, is suitable for coating, and becomes transparent. If available, other latexes and thermoplastic resins in the form of organosol solutions can also be used.

The transparent resin layer contains 1 to 15% by weight of an organic tin compound.
It is necessary to preferably contain 2 to 7% by weight,
Examples of organic tin compounds include dibutyltin dilaurate,
Any material can be used as long as it is partially compatible with other components of the transparent resin composition, such as dibutyltin dimaleate and dibutyltin mercaptite.

As a suppression ink, 1 to 40% by weight of a sulfur compound is added to the same ink as shown in the normal ink section.
Preferably, a sulfur compound containing 5 to 20% by weight can be used, and triazine derivatives such as 2,4,6-trimercaptotriazine can be used as the sulfur compound.

〔Example〕

Apply the following expandable vinyl chloride plastisol onto 500μ thick asbestos paper using a knife coater.
Apply to a thickness of 200μ, heat at 150°C for 1 minute to gel, and after cooling, it contains an ordinary vinyl chloride ink using acrylic vinyl chloride as a binder and 30% by weight of 2,4,6-trimercaptotriazine. A pattern is printed using anti-foaming ink, and then the transparent vinyl chloride plastisol shown below is applied to a thickness of 80 μm using a knife coater and coated at 200°C.
A foamed vinyl chloride sheet with unevenness was obtained by heating for a minute and a half. As a result, a beautiful ornament was obtained in which the gloss of the concave portions was significantly lower than that of the convex portions, and the difference in gloss was in sync with the concave and convex portions.

Resin for foamable vinyl chloride plastisol vinyl chloride paste (average degree of polymerization
1000) 100 parts by weight Dioctylphthalate (plasticizer) 35 parts by weight Butylbenzyl phthalate (plasticizer) 18 parts by weight Zn-based stabilizer 3 parts by weight Titanium dioxide 5 parts by weight Azodicarbonamide 2.5 parts by weight Mineral spirits Some amount Transparent vinyl chloride Resin for plastisol vinyl chloride paste (average degree of polymerization
1750) 90 parts by weight Vinyl chloride coarse grain resin (average degree of polymerization 1000)
10 parts by weight Dioctyl phthalate 30 parts by weight Butylbenzyl phthalate 15 parts by weight Dibutyltin dilaurate 4 parts by weight Mineral spirits Some

[Brief explanation of the drawing]

The drawings are cross-sectional views showing an example of a decorative article obtained by the present invention, with FIG. 1 showing a cross-sectional view before foaming, and FIG. 2 showing a cross-sectional view after foaming. DESCRIPTION OF SYMBOLS 1... Base material, 2... Foamable resin layer, 3... Normal ink, 4... Transparent resin layer, 5... Suppression ink, 6... Concave portion, 7... Convex portion.

Claims (1)

[Claims] 1. Printing is performed on the foamable resin composition layer using an ink containing a foaming inhibitor, and then a transparent resin layer is applied thereon and heated and foamed to form a surface-covered foam having an uneven surface that matches the pattern. The manufacturing method is characterized in that a polyvinyl chloride resin containing an organotin compound is used as the transparent resin layer, and a triazine derivative-based sulfur compound is used as the foaming suppressor, thereby reducing the gloss on the surface of the suppression zone. A method for manufacturing decorative items.