JPS5941853B2 - Method for manufacturing foam with uneven surface - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for imparting uneven steps to the surface of a foamed resin composition layer, and more specifically, the present invention relates to a method of imparting uneven steps to the surface of a foamed resin composition layer. This creates a viscosity difference during heating between the polymerized or cured area and other areas of the foamed resin composition layer, thereby increasing the thickness of the foamed resin composition layer or The present invention relates to a novel method for producing a foam having an uneven pattern on the surface by changing the surface shape.

One of the features of the present invention is that it is possible to easily produce a product with an embossed pattern that matches the pattern printed on the surface of the foam. Its characteristics will be explained in comparison with the manufacturing method. BACKGROUND ART Conventionally, two methods have been proposed for producing a foam having an uneven surface that is in sync with printing.

The first method is a so-called mechanical embossing method that involves contact with materials such as molds, embossing rolls, and release paper during the foam manufacturing process, and the second method is chemical embossing. In this method, an uneven surface is formed by partially changing the decomposition temperature of the blowing agent used to form the foam. In the mechanical embossing method,
Generally, there are disadvantages such as the high cost of the equipment used for stamping and limitations on processing speed, but the biggest problem is that it is difficult to synchronize with the printed pattern. For this purpose, a method of printing and embossing using the same plate, so-called burley printing, has been used, but it has been difficult to satisfy the requirements of multicolor, high speed, and low cost. In the chemical embossing method, which aims to solve the problem of synchronization with the printed pattern,
Control of the decomposition temperature of the decomposable blowing agent contained in the resin The melt viscosity of the resin composition layer is controlled by the components in the printing ink for the resin layer before foaming, and then the expansion in the heating and foaming step is This is a partial change in degree. The biggest advantage of this method is that the printed pattern and the embossed pattern match, but it is necessary to balance the decomposition conditions of the foaming agent, the resin composition, and the heating conditions, and there are significant compositional limitations. Further, problems caused by decomposed foaming agent residues, undecomposed foaming agents remaining, etc. cannot be avoided. The method of the present invention differs from the above methods in that it forms a foamed resin layer in advance, hardens only a portion of the resin layer to provide resistance to heat deformation, and then heats it to make it uncured. By melting only the resin layer in that part and collapsing this cell structure, the foamed resin layer in the previous hardened part forms a convex part, and the other part becomes a concave part. The purpose is to produce a foam having a

To explain the present invention in more detail with reference to the drawings, first, a foamed resin composition layer 2 is formed on a base material 1 as shown in FIG.

Methods for forming the foamed resin composition layer include a sintering method in which resin composition particles are mechanically compressed or further heated, and a substance soluble in a specific solvent is dispersed in the composition and then eluted. The elution method uses mainly inorganic blowing agents among decomposition type blowing agents to form pores, or the volatile components such as water are used to disperse or dissolve them in the resin composition and then heat to release the gas. A blowing agent method in which a resin composition is generated, a mechanical foaming method in which a resin composition and a gas such as air are mechanically mixed under pressure or normal pressure, a chemical reaction method in which a condensation reaction product is used as a gas, and a combination thereof. However, in order to increase the difference in unevenness, it is necessary that the pore volume in the foamed resin composition layer is large. The foamed resin composition layer formed by the above method mainly has an open cell structure, but a foamed resin composition having a closed cell structure may also be used.

The resin composition used for the foamed resin composition layer must have a viscosity that allows the composition containing the resin to be formed into a foamed form by any of the methods described above, and that the composition causes collapse of the cell structure by heating. Any material may be used as long as it produces fluidity to the extent that this fluidity is inhibited by partial curing. Depending on the means of partial curing, for example, heat or In the case of photopolymerization, corresponding resin systems and curing catalysts are used.

Curing here refers not only to phenomena such as insolubility and infusibility caused by the formation of a three-dimensional network structure in the case of thermosetting resins, but also to the thermal fluidity of the composition due to polymerization or crosslinking of components in the composition. refers to a phenomenon in which the As the base material 1, any material can be used, for example, paper, synthetic paper, nonwoven fabric, woven fabric, wood base materials such as plywood, inorganic base materials such as particle board, hardboard, cement board, synthetic resin film or sheet. A single type of base material or a composite base material of two or more of these base materials is selected depending on the purpose.

Further, these base materials 1 may become part of the final product, or may not become part of the final product and may be peeled off from the product. In the present invention, a cured portion and an uncured portion are formed in the foamed resin composition layer 2.

Various means can be considered to form a hardened portion and an uncured portion in the foamed resin composition layer 2. To illustrate some of the means, as shown in FIG. 2, a curing catalyst, a curing initiator, or a curing accelerator 3 for the foamed resin composition layer 2 is partially applied to the surface of the foamed resin composition layer 2 to cause curing. This is a method in which the portion to which the catalyst, curing initiator, or curing accelerator 3 has been applied is cured, and the other portions are left uncured. Another method is to partially apply a substance 3'' containing a curable component to the surface of the foamed resin composition layer 2, as shown in FIG. In these cases, known thermosetting and thermoplastic resins are used as the resin composition forming the foamed resin composition layer.For example, diallylphthalate resin, unsaturated polyester When a thermosetting resin such as resin is used, the substance 3 is t-
Those containing an organic peroxide curing initiator such as butyl peroxide and methyl ethyl ketone peroxide, and those containing a known curing accelerator such as cobalt naphthenate and dimethylaniline can be used. Other known combinations of curing catalysts for the resin layer include toluene sulfonic acid for the initial condensate of condensation resins such as funinol formaldehyde resin, melamine formaldehyde resin, urea formaldehyde resin, and xylene formaldehyde resin. Combinations such as acid catalysts or tertiary amines to epoxy resins can also be used. As the substance 3', a substance containing a crosslinking component such as styrene, diallyl phthalate, methacrylic acid ester, and phosphoacrylic acid ester can also be used.

In addition, as for 3, in the case of containing a curable component, that is, a component that increases the heat deformation resistance of the composition layer by polymerizing itself, curing of the resin itself is not necessarily necessary, as described below. Therefore, it goes without saying that resins other than thermosetting resins can also be used as resin composition components.
As the resin used in the resin composition layer, known thermoplastic resins such as polyvinyl chloride, polyvinyl acetate, polystyrene, polyethylene, polypropylene, or their binary or ternary copolymers can also be used.

When these thermoplastic resins are used as the resin composition, the 3' substance is a polymerizable component such as neopentyl glycol triacrylate, trimethylolpropane triacrylate, 1,6-hexanediol diacrylate, 1, Those containing known polyfunctional monomers such as 4-butanediol diacrylate, polyethylene glycol diacrylate, diallyl phthalate, and triallyl cyanuric acid are preferred, but they penetrate into the resin composition and are polymerized and cured at room temperature or by heating. Any material that can be obtained may be used, and in addition to the above-mentioned polyfunctional monomers, those containing combinations of known polymerizable monomers, oligomers, polymers, etc. and their polymerization catalysts are generally used. Other methods for forming cured portions and uncured portions in the foamed resin composition layer 2 include visible light, ultraviolet light, infrared light,
It is also possible to form a foamed resin composition layer that is cured by radiation, etc., and partially apply active energy rays such as visible light, ultraviolet rays, infrared rays, and radiation to form a cured portion and an uncured portion. good.

As a means of partially applying active energy rays, the fourth
As shown in the figure, ink or paint 5 that blocks active energy rays may be applied partially. Alternatively, although not shown, a mask may be used that has a portion that transmits active energy rays and a portion that does not transmit active energy rays. In this case, the mask is peeled off after irradiation with active energy rays. Further, the thermoplastic resin film may be provided with a portion that transmits the active energy rays and a portion that does not transmit the active energy rays, and the thermoplastic film may be integrated with the foamable resin composition layer 2 by pasting or fusing. As described above, by irradiating active energy rays from the direction shown by arrow 6, a cured portion and an uncured portion are formed.

Of course, it goes without saying that active energy rays such as visible light, ultraviolet rays, electron beams, and radiation may be used to irradiate only the areas to be cured in a spot-like manner. FIG. 4 shows a state in which an ink or paint 5 that blocks active energy rays is partially formed on the surface of a foamed resin composition layer formed on a base material, and in this case, the foamed resin composition The material must be UV curable.

Such compositions include not only known ultraviolet curable resins, but also compounds having two or more ethylenically unsaturated groups and combinations thereof with ultraviolet ray polymerization initiators or photosensitizers. It is fine as long as it includes. In the above, 3 or y is partially applied to the surface of the foamed resin composition layer.
The method of forming the substance or the shielding layer of 5 includes printing, transfer,
Known methods such as lamination may be used and the shielding layer 5 need not necessarily be part of the product as shown.

After forming the cured portion and the uncured portion in the foamed resin composition layer 2 as described above, the foamed resin composition layer 2 is heated.

Due to this heating, the uncured portion of the foamed resin composition layer melts and sinks, forming the recess 4. Therefore, the heating conditions in this case, that is, the temperature and time sufficient to cause the uncured portion to melt and collapse, are appropriately selected depending on each resin.

Note that a surface protective resin layer may be further applied if necessary.As described above, in the present invention, a cured portion and an uncured portion are formed in the foamed resin composition layer, and then heated. This provides a new method for manufacturing a foam with an uneven surface by melting and sinking the uncured portion, and the products obtained in this way can be used as flooring materials, wall materials, ceiling materials, Its application range is extremely wide, including furniture materials.

Next, examples will be shown.

[Example 1] (1) Plastisol having the following composition was prepared using a mixer with a capacity of 15 tons.

(2) This plus sol was stirred for 12 minutes using a Hobart mixer to create a foaming sol with a density of 0.329/d.

This is applied to asbestos paper soil with a basis weight of 100g/M2.
2.2m7! Apply to a thickness of L and heat in 140℃ hot air for 5 minutes.
The mixture was heated for a minute to gel and form a foamed sheet. Screen printing was performed on the surface of this gelled sheet using an ink with the following composition. (3) This printed sheet was heated with infrared rays for 3 minutes from the printed side in a hot air oven at an ambient temperature of 190°C, and then allowed to cool.

(4) As a result, a decorative foam sheet was obtained which had an uneven surface that matched the printed pattern, with the printed pattern portion becoming a convex portion and the non-printing portion becoming a concave portion.

[Example 2] (1) A latex with the following composition was prepared.

Stir for a while to form a foamed latex with a density of 0.38 and a basis weight of 8.
09/M2 base paper to a thickness of approximately 1.0 mm,
A foamed sheet was created by heating at 45° C. for 4 minutes. 3)
Gravure printing was performed on the surface of this sheet using an ink having the following composition.

4) Ultraviolet rays were irradiated from the surface of the sheet with the above printing applied.

Irradiation was performed using a high-pressure mercury lamp (output 80W/Cfn).
Distance from lamp 10CI! The test was carried out by moving the sheet on the plane L at a speed of 6 m/min. Next, gravure printing was performed using a general soft vinyl chloride ink, and then heating was performed at 190° C. for 2 minutes in a hot air heating furnace equipped with an infrared heating device at the end. 5) As a result, a decorative foam sheet having an uneven surface in which the printed portions in (3) were concave portions and the other portions were convex portions was obtained.

[Example 3] 1) A plastisol with the composition below was created.

Claims (1)

[Scope of Claims] 1. A surface characterized by forming a cured portion and an uncured portion in a foamed resin composition layer and then heating the foamed resin composition layer to cause the uncured portion of the foamed resin composition layer to melt and sink. A method for producing a foam having unevenness. 2. The method according to claim 1, wherein active energy rays such as ultraviolet rays, visible rays, infrared rays, and radiation are used as means for forming a cured portion in the foamed resin composition layer. 3. The method according to claim 1, wherein a foamed resin composition formed by mechanical foaming is used as the foamed resin composition.