JPH0647875A - Decorative sheet and production thereof - Google Patents

Abstract

PURPOSE:To provide a decorative sheet having various functions and design effect different from those of a prior art decorative sheet composed of an ethylene/vinyl acetate copolymer. CONSTITUTION:A decorative layer composed of an emulsion containing an acrylic resin and an ethylene/vinyl acetate resin is formed. This emulsion shows good embossing properties, good film forming properties (coating or printing aptitude) and excellent yellowing resistance (in its turn excellent color developability of pigment) by the synergistic action of the acrylic resin (or an acrylic emulsion) and the ethylene/vinyl acetate resin (or an ethylene/vinyl acetate emulsion) and the sheet due to the emulsion has good flexibility capable of withstanding practical use as wall paper or various decorative sheets.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to construction (ceiling materials, wall materials,
Floor material), furniture, vehicles, bags, electric appliances, footwear, etc., and more specifically to a decorative sheet in which the decorative layer is made of a specific synthetic resin emulsion and a method for producing the same. .

[0002]

BACKGROUND ART Conventionally, as a decorative sheet of this type, a foamable or non-foamable ethylene-vinyl acetate copolymer emulsion has been used, which is applied to a base material and printed to form a decorative layer. there were. However, this product is not sufficiently satisfactory in terms of embossing property, yellowing resistance, coatability or printability, and its improvement has been demanded.

[0003]

OBJECTS OF THE INVENTION The present invention has been made in order to meet such a demand, and one of the objects thereof is that the emboss is sharp and the yellowing resistance is excellent, and the coating or printing suitability is also excellent. It is to provide a decorative sheet exhibiting the above characteristics. Another object is to provide a decorative sheet that does not generate harmful gas upon incineration after use.

[0004]

SUMMARY OF THE INVENTION As a result of repeated studies to achieve the above object, the present inventors have replaced an ethylene-vinyl acetate copolymer emulsion with an acrylic resin and an ethylene-vinyl acetate resin. If a mixed emulsion is used, not only a sharp uneven pattern can be formed by embossing, but also there is no problem of yellowing, and the coating property on the substrate or printability is excellent, and a good decorative layer is formed. We have found that it can be easily formed.

The decorative sheet of the present invention is based on the above findings and is characterized in that a decorative layer made of an emulsion containing an acrylic resin and an ethylene-vinyl acetate resin is formed.

In the present invention, as the acrylic resin, polymers such as acrylic acid ester, methacrylic acid ester, acrylic acid, methacrylic acid, acrylamide, acrylonitrile, and other monomers copolymerizable with these compounds are used. These copolymers and the like can be used alone or in admixture of two or more.

In the present invention, the ethylene-vinyl acetate resin used together with the above acrylic resin has an ethylene content of 5 to 95% by weight, preferably 5% by weight.
Those of 0 to 90% by weight are suitable. When the content of ethylene is smaller than the above (in other words, the content of vinyl acetate is larger than the above), the heat resistance is lowered and the yellowing tends to occur easily. On the other hand, when the ethylene content is higher than the above (the vinyl acetate content is lower than the above), the foamability at the time of foaming deteriorates.
The above ethylene contents may be used alone or in combination of two or more kinds.

If the above acrylic resin, ethylene-vinyl acetate resin, or a mixture thereof has a high glass transition point (hereinafter, Tg point), the product sheet has a high dry feel, and the Tg point is higher. The lower the value, the higher the wet feeling. Therefore, a combination having an appropriate Tg point may be selected and used according to the tactile sensation required for the product sheet.

The mixing ratio of the acrylic resin and the ethylene-vinyl acetate resin in the mixed emulsion containing the acrylic resin and the ethylene-vinyl acetate resin is 20 to 80% by weight of the acrylic resin and ethylene-acetic acid. The vinyl resin is preferably 80 to 20% by weight, more preferably the acrylic resin is 30 to 50% by weight and the ethylene-vinyl acetate resin is 70 to 50% by weight.

When the mixing ratio of the acrylic resin to the ethylene-vinyl acetate resin is less than the above lower limit, properties such as embossing property, yellowing resistance and foaming property become insufficient, while when it is more than the above upper limit, it is obtained. The decorative layer becomes fairly hard and tends to crack and crack. Therefore, in the present invention, the mixing ratio is as described above.

If the solid content of the above-mentioned mixed emulsion is too small, it becomes difficult to dry, so that the solid content is 30% by weight.
It is preferable that the amount is above, and more preferably 50% by weight.
That is all.

When a foamed product is used as the decorative layer of the above mixed emulsion, a mechanical foaming method in which air is contained in the emulsion by a mechanical stirring means or a microcapsule containing a thermal expansion agent is used. And the like, and a chemical foaming method in which a thermal decomposition type chemical foaming agent is contained in the emulsion.

The microcapsules containing the above-mentioned thermal expansion agent used in the present invention have a particle size of about 10 to 30 μm in which a low boiling point solvent is wrapped in a coating or shell of a thermoplastic polymer material.
It is a container consisting of m microspheres, and the shape of the capsule is
It may be a single capsule, a polynuclear capsule, a polynuclear tufted capsule, a double capsule, a capsule cluster, or a self-contained type capsule. The shell of the heat-expandable microcapsule generally has a wall thickness of 10 μm or less, more preferably 7 μm or less, but it is necessary that it is thermoplastic and has a good gas barrier property. For example, it is formed from a copolymer mainly containing vinylidene chloride / acrylonitrile or a polymer mainly containing acrylonitrile / acrylic copolymer. In carrying out the method of the present invention, it is desirable that the heat-expandable microcapsules be blended in an amount of 40 parts or less, more preferably 20 parts or less, based on the weight of the polyvinyl chloride paste resin.

The amount of air blown in by the above mechanical foaming method, or the expansion agent such as microcapsules and the thermal decomposition type chemical foaming agent in the case of the chemical foaming method are determined by the desired foaming of the decorative layer of the product sheet. It may be adjusted appropriately according to the degree. Further, as the microcapsules and the thermal decomposition type chemical foaming agent, usual ones used for foaming various layers of emulsion can be used.

However, in the case of mechanical foaming, bubbles may be broken and aggregated during application, or gas may escape to the outside at the time of foaming, so that desired foaming may not be achieved.
In the case of foaming using a thermal decomposition type chemical foaming agent, in order to obtain a foaming agent having a sufficient expansion ratio, the foamable decorative sheet must be exposed to an atmosphere of a high temperature of 200 ° C. or higher. Thermal discoloration may occur and there is a concern that it will turn yellow.

In this respect, the one using a thermal expansion type foaming agent typified by microcapsules can secure a sufficient expansion ratio even at a temperature of 140 to 200 ° C., so that it is uniform in terms of yellowing. It can be said to be advantageous and preferable for obtaining the state. In addition, in the present invention, the thermal expansion type foaming agent such as the microcapsules is not limited to be used alone at the time of foaming, and it is of course possible to use it together with the thermal decomposition type chemical foaming agent depending on the purpose. Is.

Further, in the present invention, in the above mixed emulsion, in addition to the above-mentioned microcapsules and the thermal decomposition type chemical foaming agent, a screen printing suitability improving agent (the emulsion of the present invention can be prepared by a screen printing technique. It has a function of improving the printability when applied to the base material of the decorative sheet (details will be described later), and a drying retardant (only the surface portion of the applied emulsion is quickly dried to form a so-called skin on the surface). Acts to prevent spills), thickeners,
Additives such as a filler, a defoaming agent, a pigment, a flame retardant, and an antifungal agent can also be added.

In the case of screen printing, an emulsified terpene (comprising a terpene, water and an emulsifier) can be used as a screen printing suitability improving agent, and the mixing ratio is 15 with respect to 100 parts by weight of the above mixed emulsion. To 50 parts by weight, and more preferably 25 to 35 parts by weight.
Parts by weight.

As the drying delay agent, ethylene glycol, diethylene glycol, polyethylene glycol or the like can be used, and polyethylene glycol is preferably liquid at room temperature. The mixing ratio of the dry retarder is preferably 2 to 10 parts by weight with respect to 100 parts by weight of the above mixed emulsion.

As the thickener, sodium polyacrylate,
What is normally used as a thickener of an emulsion, such as carboxymethyl cellulose (CMC) and hydroxyethyl cellulose (HEC), can be used. The mixing ratio of the thickener may be a ratio that can adjust the above-mentioned mixed emulsion to a necessary viscosity.

As the filler, those generally used as fillers for emulsions such as aluminum hydroxide, magnesium hydroxide, calcium carbonate and magnesium carbonate can be used. The blending ratio of the filler is
0-50 based on 100 parts by weight of the above mixed emulsion
It is preferable to set it as a weight part, More preferably, it is 10-4.
0 parts by weight.

As the defoaming agent, those generally used as the defoaming agent for emulsions can be used.
The mixing ratio is preferably 0.01 to 1.5 parts by weight with respect to 100 parts by weight of the above mixed emulsion.

As the pigment, either organic or inorganic pigments generally used as emulsion pigments can be used, and the mixing ratio thereof can be appropriately adjusted according to the desired color of the decorative layer. .

Examples of the flame retardant include halogen flame retardants such as halogenated phosphoric acid ester, antimony trioxide, zinc borate, magnesium triphosphate, magnesium phosphite, guanidine sulfamate, thiourea and guanidine phosphate. Although non-halogen flame retardants such as the above can be used, non-halogen flame retardants are preferable.

As the antifungal agent, 10,10'-oxybisphenoxyarsine, N- (fluorodichloromethylthio) -phthalimide, 2- (4-thiazole) benzimidazole, N-trichloromethylmercapto-4.
-Cyclohexane-1,2-dicarboximide, 2,
Organic antifungal agents such as 4,5,6-tetrachloroisophthalonitrile and inorganic antifungal agents such as barium metaborate can be used.

The base material on which the decorative layer is formed by the above mixed emulsion is a base material used for a conventional synthetic resin sheet such as backing paper, synthetic resin sheet, woven cloth, non-woven cloth, knitted cloth and the like. Can be used. In addition,
As the above-mentioned backing paper, it is also possible to use embossed backing paper which has been given an uneven design by embossing or the like in advance.

When the base material is a backing paper using ordinary pulp or the like, the backing paper absorbs the water content of the emulsion to cause uneven expansion of the backing paper, uneven expansion and contraction of fibers constituting the backing paper, etc. In many cases, a so-called wavy phenomenon occurs in the entire decorative sheet. In such a case, the technique disclosed in Japanese Patent Application No. 2-248082 proposed by the present inventor is applied to apply an inorganic powder to at least the surface side of the backing paper on which the decorative layer is formed. It is preferable to use one having a coating layer as a main component.

As the inorganic powder, aluminum hydroxide, magnesium hydroxide, titanium oxide, silicon dioxide,
Aluminum silicate, magnesium silicate, calcium carbonate, zinc oxide, barium sulfate, talc, kaolin, clay and the like can be used. These inorganic powders are casein,
Made into a paint with a binder such as starch or a synthetic resin such as acrylic resin, vinyl chloride resin, vinyl acetate resin, ethylene-vinyl acetate copolymer resin, styrene-butadiene rubber (SBR), polyvinyl alcohol (PVA), and melamine resin. Has been used. The paint may be either an emulsion type or a solvent type, but the emulsion type is preferable from the viewpoint of preventing atmospheric (air) pollution.

As the coating means for coating the above-mentioned paint on the backing paper, a general coating means such as a doctor knife coater, a roll coater, an air coater or the like is adopted. Immediately before forming the decorative layer (however, forming the decorative layer is performed after drying the coating layer)
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The means for forming the decorative layer by the above mixed emulsion is the same as the above-mentioned means for coating the backing paper with the coating layer mainly composed of the inorganic powder, such as a doctor knife coater, a roll coater and an air knife coater. In addition to the general coating means described in (1), printing means such as gravure printing and rotary screen printing can be adopted. When the printing means such as gravure printing or rotary screen printing is used, the decorative layer can be formed on the entire surface or a part of the base material.

The layer of the mixed emulsion thus coated or printed is dried to form a decorative layer. The drying conditions at this time are 100 to 130 ° C. and 10
Seconds to 5 minutes are sufficient. If desired, a pattern layer can be printed on this decorative layer. When the decorative layer is formed into a foam layer by the above-mentioned chemical foaming method, after this drying, heat treatment is performed under conditions suitable for the foam material used. For example, when microcapsules are mixed, it is necessary to hold at 160 to 190 ° C. for about 30 to 90 seconds, and when a pyrolytic chemical foaming agent is mixed, the temperature at which the foaming agent decomposes. And holding time is required.

The above decorative layer may be formed of a single layer or a plurality of layers. In the case of a plurality of layers, a combination of a foamed layer and a non-foamed layer can be used. If necessary, the surface of the decorative layer formed as described above may be subjected to various surface treatments such as adjusting the gloss such as matting and polishing, imparting antifouling properties, and increasing the surface strength. It can also be applied.

This surface treatment is carried out by applying and drying a surface treatment agent to form a surface treatment layer, or laminating various films. As the surface treatment agent, either an aqueous system containing an acrylic resin or a urethane resin as a main component or a solvent system can be used, but an aqueous system is preferable from the viewpoint of preventing atmospheric (air) pollution. As the film to be laminated, an acrylic resin film,
Polyester resin film, olefin resin film (including ethylene-vinyl acetate copolymer film, ethylene-vinyl alcohol copolymer film, etc.), fluorine resin film, and other films made of resins other than vinyl chloride resin Any of these can be used.

The laminate may be a thermal laminate that does not use an adhesive or an adhesive laminate that uses an adhesive. As the adhesive used for the adhesive laminate, any adhesive such as an acrylic adhesive and a urethane adhesive can be used, and may be a water-based adhesive or a solvent-based adhesive, and a resin that forms a film. It is preferred to use compatible adhesives. Further, it is preferable that the adhesive is applied and adhered to the film side to be laminated.

The film may be laminated before being embossed by mechanical means described later, or may be laminated simultaneously with the embossing. The film to be laminated may have a thickness of 10 to 100 μm, preferably 10 to 50 μm. When the thickness is less than 10 μm, the film is too thin and the workability is deteriorated, and wrinkles easily occur during lamination, which is not preferable. On the contrary, if it exceeds 100 μm, the film becomes too thick and the cost becomes high, which is not preferable.

Further, the concavo-convex design can be imparted simultaneously with the formation of the decorative layer by the above-mentioned mechanical foaming or chemical foaming embossing means, or by the mechanical embossing means such as an embossing roll. It can also be performed after forming the decorative layer.

[0037]

In the present invention, the acrylic resin (or acrylic emulsion) and ethylene
The synergistic action with the vinyl acetate resin (or ethylene-vinyl acetate emulsion) produces the following action. (1) In order to exhibit a good embossing property, a sharp uneven pattern is formed by embossing. (2) Since it exhibits good film forming (layer) properties (applicability or printability), it is easy to form a good decorative layer without scratches and the like. (3) Since the pigment exhibits excellent yellowing resistance, the color developability of the pigment becomes good. (4) It exhibits sufficient flexibility. (5) Due to these (1) to (4), it is possible to provide wallpaper that can be sufficiently put into practical use and other various decorative sheets.

[0038]

【Example】

Example 1 The formulations having the compositions shown in Table 1 were mixed by stirring with a mixer, and the air entrained during stirring was degassed in vacuum to prepare a heat-expandable mixed emulsion.

[0039]

[Table 1]

On the other hand, on the side of the backing paper having a basis weight of 100 g / m ² (trade name "TT-100C" manufactured by Tokushu Paper Co., Ltd.) on which the decorative layer is formed (the surface on which the layer containing the inorganic powder main component is formed). The thickness of the above heat-expandable mixed emulsion is 0.1 after drying.
to 130 mm with a doctor knife
And dried for 2 minutes to form an expandable decorative layer. Then, this is heat-treated at 180 ° C. for 70 seconds to expand the microcapsules in the decoration layer to form a foamed decoration layer, and immediately after the heat treatment, embossing is performed with a cold embossing roll to form an uneven pattern. It formed and obtained the sheet | seat of this invention.

The obtained sheet of the present invention has an expansion ratio of 4.
5 times, there is no heat discoloration, the uneven pattern is sharp,
The surface feel is dry, and the decoration layer is flexible enough,
It was a good wallpaper.

Example 2 After forming an expansive decorative layer under the same conditions as in Example 1, this is heat-treated at 180 ° C. for 70 seconds to expand the microcapsules in the decorative layer and to have a thickness of 15 μm. An ethylene-vinyl alcohol copolymer film (using Kuraray Co., Ltd. trade name "EVAL") is heat-laminated along the cold embossing roll with the embossing roll and the backup roll, and at the same time embossed to form an uneven pattern. did.

The obtained sheet of the present invention has the same expansion ratio as that of the sheet of the present invention obtained in Example 1, there is no discoloration by heating, the uneven pattern is sharper, the surface feel is dry, and The decorative layer is sufficiently flexible and is preferable as a wallpaper, and at the same time, since the surface treatment layer formed by film lamination is formed, it is also excellent in scratch resistance, durability and antifouling property, and is obtained in Example 1. It is more preferable as a wallpaper than the sheet of the present invention.

Example 3 Of the compositional formulations shown in Table 1 of Example 1, an acrylic acid ester-methyl methacrylate copolymer / ethylene-vinyl acetate copolymer emulsion having an ethylene content of 70% by weight was mixed with acrylic acid. Ester-methyl methacrylate copolymer / ethylene-vinyl acetate copolymer = 30/70
% By weight (solid content 55% by weight, and Example 1 except that the coating thickness of the heat-expandable mixed emulsion with a doctor knife is 0.12 mm in thickness after drying)
In the same manner as above, an expandable decorative layer was formed.

An acrylic surface treatment agent was dried on the surface of this decorative layer by a gravure coater, and then coated to an average thickness of 3 μm, and dried at 130 ° C. for 1 minute. Then, this was heat-treated under the same conditions as in Example 1 to expand the microcapsules in the decoration, and embossed to form a concavo-convex pattern to obtain a sheet of the present invention.

Like the sheet of the present invention obtained in Example 1, the obtained sheet of the present invention had a foaming ratio of 4.5 times, no heat discoloration, a sharp uneven pattern, and a dry surface feel. Moreover, the decorative layer is sufficiently flexible and is preferable as a wallpaper, and at the same time, since the surface treatment layer is formed, it is also excellent in scratch resistance and antifouling property, and the sheet of the present invention obtained in Example 1 It is more preferable than wallpaper.

Comparative Example A heat-expandable emulsion was prepared in the same manner as in Example 1 except that the compositions shown in Table 2 were used.

[0048]

[Table 2]

An intumescent decorative layer was formed in the same manner as in Example 1 except that the above emulsion was used and the thickness of the emulsion coated with a doctor knife was 0.12 mm after drying. .

This is heat-treated at 180 ° C. for 70 seconds,
While expanding the microcapsules in the decorative layer,
Immediately after the heat treatment, embossing was performed with a cold embossing roll to form an uneven pattern to obtain a comparative sheet.

The obtained comparative sheet had a foaming ratio of 4.0 times lower than that of the sheets of the present invention obtained in Examples 1 and 2, and had good flexibility, but only if yellowing due to heating was observed. Without embossing, the surface feel was slightly wet (viscous) and the wallpaper lacked a high-class feel.

[0052]

As described above in detail, since the present invention uses the mixed emulsion, it exhibits good embossing property, film-forming (layer) property (applicability for printing or printing), foamability, and sharpness by embossing. It is possible to easily form a fine uneven pattern and a good decorative layer, and also to have excellent flexibility. In addition, since the decorative layer formed of the mixed emulsion exhibits excellent yellowing resistance, the coloring property of the pigment becomes good, and it is possible to provide wallpaper and other various decorative sheets that are extremely useful in practice.

Claims (12)

[Claims] 1. A decorative sheet comprising a decorative layer made of an emulsion containing an acrylic resin and an ethylene-vinyl acetate resin. 2. A decorative sheet comprising a foamed decorative layer formed of an emulsion containing an acrylic resin and an ethylene-vinyl acetate resin and an expanding agent. 3. A mixing ratio of the acrylic resin and the ethylene-vinyl acetate resin in the emulsion containing the acrylic resin and the ethylene-vinyl acetate resin is 20 to 80% by weight of the acrylic resin, and the ethylene-vinyl acetate resin. Resin 8
The decorative sheet according to any one of claims 1 to 4, which is 0 to 20% by weight. 4. The decorative sheet according to claim 2, wherein the expanding agent is a microcapsule containing a thermal expanding agent. 5. The decorative sheet according to claim 1, wherein a coating layer mainly composed of inorganic powder is formed between the base material and the decorative layer. 6. The decorative sheet according to claim 1, wherein a surface treatment layer made of a film laminate or a surface treatment agent is formed on the decoration layer. 7. A substrate is coated with an emulsion composition comprising an emulsion containing an acrylic resin and an ethylene-vinyl acetate resin and a swelling agent by a coating method,
After drying, a pattern layer is printed on this surface, followed by heat-foaming and embossing, which is a method for producing a decorative sheet. 8. An emulsion composition comprising an emulsion containing an acrylic resin and an ethylene-vinyl acetate resin and a swelling agent is applied to a substrate entirely or partially by a rotary screen method, dried and then heated and foamed. A method for manufacturing a decorative sheet, comprising: 9. A base material is coated with an emulsion composition containing an acrylic resin and an ethylene-vinyl acetate resin by a coating method or a rotary screen method, partially or entirely, and dried, and then an acrylic resin and ethylene are further added. A method for producing a decorative sheet, which comprises applying an emulsion composition containing a vinyl acetate-based resin entirely or partially by a rotary screen method, drying and then surface-treating. 10. A coating material containing an inorganic powder is applied by a coating method and dried prior to applying the emulsion composition to the substrate.
A method for producing a decorative sheet according to. 11. The method for producing a decorative sheet according to claim 9, wherein the emulsion composition contains a swelling agent and is subjected to surface treatment and then foamed by heating. 12. The method for producing a decorative sheet according to claim 9, wherein one of the emulsion compositions contains a swelling agent and the other does not contain a swelling agent.