JPH10100596A - Method of manufacturing decorative board and decorative board manufactured thereby - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a decorative plate having a highly designable surface having an uneven shape on the surface and at the same time having a good surface property of a decorative layer without occurrence of pattern missing or generation of burrs. SOLUTION: In a method for manufacturing a decorative board, in which a desired decorative layer 6 is transferred by a transfer sheet 8 to a base material 1 having an uneven surface, a moisture-curable hot melt adhesive is applied only to the uneven portions. Forming the adhesive layer 4, placing the transfer sheet 8 thereon and pressing it with the hot roll 9, and peeling the support sheet 5 of the transfer sheet 8 so that only the protrusions on the surface of the base material are desired. A step of transferring the decoration layer 6 is employed.
After the support sheet 5 of the transfer sheet 8 is peeled off, it is preferable to add a step of further pressing with a roll. Since the moisture-curable hot-melt adhesive has a high initial adhesive strength, it does not cause pattern missing or burrs during transfer. In addition, since the adhesive force increases with the passage of time, the surface properties such as the abrasion resistance of the decorative layer are also good.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a decorative plate having a decorative layer on the surface, and more particularly to a method for efficiently manufacturing a decorative plate having a highly designed surface having an uneven surface.

[0002]

Conventionally, as a method of manufacturing a decorative board having a decorative layer on the surface, a method of laminating a printed sheet on the surface, painting with a single color paint, or sprinkling a sand-like material is used. Simple methods such as However, in the method of laminating the printed sheet, when the decorative layer is formed only on the convex portion of the substrate having a large irregular shape on the surface and fine irregularities on the convex portion of the large irregular shape, the substrate convex It is not possible to express even fine irregularities in the part. Further, in the method of painting with a single-color paint or sprinkling a sand-like material, it is difficult to selectively decorate by aligning the register only with the convex portion having a large pattern, in addition to poor design.

Further, a method of using a transfer sheet having a heat transferable ink layer (transfer layer) on a support sheet and transferring the heat transferable ink layer as a decorative layer with a two-component curable adhesive layer (for example, Japanese Patent Laid-Open No. Japanese Patent Application Laid-Open No. 6-278400) or a transfer method using a heat-sensitive adhesive layer (for example, see Japanese Patent Publication No. 60-59876). However, in the method of transferring with a two-component curable adhesive layer, the adhesive force is large when completely cured, but the adhesive force until complete curing is low. , The transfer layer is not cut at the boundary between the transfer area and the non-transfer area, and a part of the transfer layer protrudes and remains at the periphery of the transfer area. Some of them remain on the support sheet side without being processed, and the pattern is likely to be missing. In addition, if peeling is performed after a lapse of a sufficient time (usually 3 to 5 days in the case of two-component cured polyurethane), these can be eliminated, but the production efficiency deteriorates. Further, in the method of transferring with the heat-sensitive adhesive layer, the initial adhesive strength is higher than that of the above-mentioned method, and although the problem at the time of peeling the transfer sheet is solved, the adhesive strength does not increase over time, and the method described above is used. Significantly lower than when fully cured. Therefore, the adhesive strength between the transferred decorative layer and the base material is low, and the surface properties of the decorative layer such as abrasion resistance, cellophane tape peeling resistance and heat resistance are low.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a decorative plate having a highly designed surface having an uneven surface, and at the same time, a surface of a decorative layer. It is an object of the present invention to provide a method capable of manufacturing a decorative board having good physical properties without occurrence of pattern removal or generation of burrs.

[0005]

Means for Solving the Problems In order to achieve the above object, the present invention relates to a method for manufacturing a decorative board, comprising transferring a desired decorative layer to a base material having an uneven surface by using a transfer sheet. Providing an adhesive layer made of a moisture-curable hot-melt adhesive only on the projections, placing a transfer sheet thereon and pressing while heating with a hot roll, and peeling the support sheet of the transfer sheet Transferring the desired decorative layer only to the projections on the surface of the base material. After the support sheet of the transfer sheet is peeled off, it is preferable to add a step of further pressing with a roll.

According to the present invention, the initial adhesive force at the time of the heat and pressure transfer is appropriately high, and the adhesive force is greatly increased with time even after the transfer. By applying the layer, it is possible to satisfactorily transfer the pattern only to the projections of the substrate having the uneven shape on the surface without causing pattern missing or burrs. In addition, after the support sheet is peeled off, by further pressing with a roll, the convex portion of the substrate having a large irregular shape on the surface is transferred to a portion having a fine irregular surface without causing detachment or adhesion failure. can do.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

First, as shown in FIG. 1, a base coat layer 2 is formed by applying a base coat to the entire surface of a substrate 1 having irregularities by means of flow coating, spray coating, brush coating or the like. This base coat layer is aimed at coloring the surface of the base material to a desired color, or for sealing a rough surface of the base material surface, and in the case of a porous base material, aiming at a sealer for closing pores, or It is formed for the purpose of a primer (or an anchor coat) for enhancing the adhesive strength with the adhesive layer.
Of course, if the surface of the base material does not require coloring, no sealer or primer is required, the base coat layer is omitted. Then
As shown in FIG. 2, the adhesive layer 4 is formed by applying a moisture-curable hot-melt adhesive to the convex portion 3 of the base material 1 covered with the base coat layer 2 by means such as roll coating.

On the other hand, as shown in FIG.
The transfer sheet is formed by forming a transfer layer thereon. The transfer layer includes at least the decorative layer 6. The decorative layer 6 includes, for example, a thermal transfer ink layer on which a pattern to be transferred by a thermal adhesive ink is printed, and a metal thin film layer formed by vacuum deposition of metal. Then, if necessary, the decorative layer 6
A release layer 7 may be formed between the support sheet 5 and the support sheet 5 to facilitate the separation of the two. This release layer 7 is transferred to the substrate 1 together with the decorative layer 6.

Next, as shown in FIG. 4, the decorative layer 6 of the transfer sheet 8 is brought into contact with the adhesive layer 4, and the decorative layer 6, the release layer 7 After the transfer, the support sheet 5 of the transfer sheet 8 is peeled off, and the decorative layer 6 and the peeling layer 7 are transferred onto the adhesive layer 4. Here, the portion of the transfer layer that is not in contact with the adhesive layer 4 is not transferred to the base material side, so that the concave portion of the base material 1 is not colored, and therefore, a very clear and sharp picture is transferred onto the base material 1. Is done.

After the above steps, if necessary, as shown in FIG. 5, a transparent paint is applied to the entire surface of the coated base material 1 by means of flow coating, spray coating or the like. A protective layer 10 is provided.

In the present invention, the substrate 1 is a plate-shaped body having a surface with an uneven shape (uneven pattern). As the concavo-convex shape, a joint of a porcelain tile or a brick arrangement, a groove between siding boards, and the like are representative. In addition, these relatively large convex-concave projections may further have fine irregularities such as a fine line sculpture pattern, a grain of sand, a satin finish, a hairline, and a granite cleavage plane. Examples of the material of the base material 1 include various veneers or plywood made of natural wood, chipboard, hardboard, particle board, inflation board, wood board of medium density fiber board (MDF), pulp cement board, and lightweight cellular concrete board. (ALC),
Various inorganic plates such as glass fiber reinforced concrete plate (GRC), asbestos calcium silicate plate, slate plate, and ceramic plate, and metal plates such as aluminum plate and iron plate can be used.

The base coat for forming the base coat layer 2 includes natural resins and synthetic resins, specifically, alkyd resins (including so-called unsaturated polyester resins), butylated aluminaldehyde resins, phenol resins, and phthalic acid-based resins. Synthetic resins such as resins, polyamide resins, vinyl resins, acrylic resins, epoxy resins, urethane resins, vinyl butyral resins, cellulose derivatives such as nitrocellulose, acetylcellulose, acetylbutyrol, etc., and rubber derivatives. As a vehicle, a paint obtained by kneading an organic pigment, an inorganic pigment, a dye, an extender (filler) or the like as a colorant, if necessary, can be used.

The moisture-curable hot-melt adhesive forming the adhesive layer 4 is essentially a urethane prepolymer having an isocyanate group (NCO group) at an end obtained by reacting a polyol (polyhydric alcohol) with an excess of polyisocyanate. As an ingredient. This prepolymer is thermoplastic in an uncured state, and exhibits the same behavior as a normal hot-melt adhesive. The prepolymer reacts with moisture (water) to form a three-dimensional cross-linked structure, thereby providing heat resistance and creep resistance. That is, the NCO group of the applied moisture-curable hot melt adhesive reacts with the moisture in the air or the adherend to extend the chain by urea bonds, and further reacts with active hydrogen of urethane bonds or urea bonds in the prepolymer component. The NCO groups react to form a branch-crosslinking reaction to form a three-dimensional crosslinked structure. In this state, the physical properties are the same as those of a cured product of a normal two-component curable adhesive. These reactions are, of course, affected by temperature and humidity, and the higher the temperature and humidity, the faster the reaction.

The following are specific examples of the polyol. Polycarbonate polyols as disclosed in JP-A-2-305882 and the like. For example, by condensation of a polyol having an average molecular weight in the range of 500 to 10,000 such as 1,6-hexanediol, 1,4-butanediol, and 1,5 pentanediol with phosgene, chloroformate, diallyl carbonate and the like. What you get. A mixture of (A) a polyester polyol and (B) a polyol having a polybutadiene skeleton (both of which are subjected to an addition reaction with an isocyanate) as disclosed in JP-A-64-14287. For example,
As the polyester polyol (A), one or more of a linear alkylene glycol having an even number of carbon atoms and a linear alkylene dicarboxylic acid having an even number of carbon atoms are appropriately combined, and preferably have an acid value of 2 or less. , Average molecular weight of 1,000 to 3
As the polyol having a polybutadiene skeleton (B), a polybutadiene having a hydroxyl group added to both terminals has an average molecular weight of 500 to 10,000.
(A) / (B) = 95/5 to 60 /
A compound blended at an equivalent ratio of 40. Polyether polyol Acryl polyol

Examples of the isocyanate include aromatic isocyanates such as 2,4-tolylene diisocyanate and 4,4'-diphenylmethane diisocyanate, and aliphatic or alicyclic isocyanates such as hexamethylene diisocyanate, isophorone diisocyanate and hydrogenated diphenylmethane diisocyanate. Is used.

In order to impart various properties to the moisture-curable hot melt adhesive, a thermoplastic resin, a tackifier, a plasticizer, a filler, and the like are usually added to the above prepolymer. Ethylene-vinyl acetate resin is used as the thermoplastic resin, and terpene-phenol resin, abietic acid rosin ester and the like are used as the tackifier. In addition, as a thermoplastic resin, low-molecular-weight polyethylene, modified polyolefin (EVA) is used for the purpose of improving adhesiveness to various adherends.
Including atactic polypropylene, linear polyester resin, and EAA. Most of these moisture-curable hot-melt adhesives contain a tackifier. Since the functional groups (-OH, -COOH, -NH, etc.) which react with the isocyanate groups are not completely eliminated, if added as they are, the moisture-curable hot-melt adhesive may lack heat stability. .
In order to improve this, a method has been proposed in which a tackifier is pretreated with an isocyanate and then added.

The time required for the moisture-curable hot-melt adhesive to complete its curing (adhesive strength is saturated) depends on the temperature, humidity and type of adhesive, but is typically 20 ° C., 60 ° C.
It is about 10 hours under the condition of% RH. And, the higher the temperature and humidity, the shorter the time required for completing the curing. Generally, it is shorter than the two-component curing type polyurethane. This moisture-curable hot-melt adhesive is applied to the substrate to be transferred. The application amount is about 10 to 300 g / m ² .

As the support sheet 5 of the transfer sheet 8,
For example, various papers such as thin paper, roll paper, woodfree paper, kraft paper, and coated paper; polyesters such as polyethylene terephthalate and polybutylene terephthalate; polyolefins such as polypropylene and polyethylene; films of various resins such as polyvinyl chloride and nylon. Alternatively, a sheet, a metal foil such as aluminum, a lamination film obtained by optionally laminating two or more of the above-mentioned paper and resin films or a sheet and a metal foil can be used. The surface of the support sheet 5 may be, for example, a silicone resin, a polyamide resin, a modified silicone resin modified with an amino alkyd resin or an epoxy resin, a polyolefin resin such as polyethylene or polypropylene, or a metal acetate of a higher fatty acid. The release layer may be formed by coating the support with a releasing agent such as roll coating, gravure coating, flow coating, spraying, or extrusion coating. This release layer (not shown) is peeled off together with the support sheet during transfer.

Examples of the heat-adhesive ink for forming the decorative layer 6 of the transfer sheet 8 include various oils and fats such as linseed oil, soybean oil, and synthetic drying oil, rosin, copearl, dammar, cured rosin, rosin ester, and the like. Natural resin and processed resin such as polymerized rosin, rosin-modified phenol resin, 100%
Synthetic resins such as phenolic resins, maleic resins, alkyd resins (including unsaturated polyester resins), vinyl acetate resins, butyral resins, acrylic resins, polyamide resins, epoxy resins, aminoalkyd resins, and nitrocellulose , Cellulose acetate, rubber derivatives such as cyclized rubber and the like as a constituent material of a vehicle, and a coloring agent such as an organic pigment, an inorganic pigment, or a dye is added to the vehicle, and further, for example, a plasticizer, a stabilizer, a drying agent, and an auxiliary drying agent. An ink obtained by arbitrarily adding known additives such as, and kneading with a solvent, a diluent or the like can be used. The pattern to be transferred onto the support sheet using this ink may be formed by a known printing method such as a gravure printing method, a flexographic printing method, a screen printing method, and an offset printing method.

In the above manufacturing method, the conditions of the heating and pressurizing treatment for transferring the transfer layer onto the adhesive layer 4 are as follows: the surface temperature of the roll is about 100 to 250 ° C .;
kg / cm ² , and the roll feed speed is preferably 5 to 20 m / min. As the heat roll 9, a roll in which the periphery of a rigid shaft made of iron or the like is covered with rubber is used. Known rubbers such as silicone rubber, neoprene rubber, SBR (styrene-butadiene rubber), fluorine rubber and viton rubber are used as the rubber, and materials having durability in addition to heat resistance are used. desirable.
Among them, the silicone rubber roll is preferable in the present invention.
The rubber hardness is preferably in the range of 60 ° to 70 °. When the rubber hardness is higher than 70 °, the transfer sheet does not easily follow the fine unevenness of the convex portion of the uneven base material, and the transfer is likely to be omitted. Conversely, if the angle is softer than 60 °, the rubber roll is pushed to the concave portions of the uneven substrate, and a desired design cannot be obtained.
Particularly good results were obtained with a silicone roll having a rubber hardness of 65 °.

In particular, in the case where there is a finer uneven pattern on the convex portion of the base material to be transferred, a heat roll is first placed on the support sheet 5 so that the transfer layer follows and adheres to the fine unevenness. It is preferable to heat and press at 9 and then peel off and remove only the support sheet 5, and then heat and press again with a hot roll. The heat roll used for the second heating and pressurization may be the same heat roll as that at the time of the first heat and pressurization. However, in order to ensure the adhesion of the transfer layer to the fine unevenness, a soft roll having a rubber hardness of 60 ° or less is required. The heat roll using the rubber of the above is more preferable.

Examples of the paint for forming the surface protective layer 10 include synthetic resins such as natural resins and synthetic resins, alkyd resins, silicone resins, acrylic resins, epoxy resins, urethane resins, and fluorine resins. Those containing a cellulose derivative such as nitrocellulose as a main component can be used. These resins may be used alone or in combination of two or more. Further, if necessary, an ultraviolet absorber such as benzotriazole and fine particle cerium oxide, a light stabilizer such as a hindered amine radical scavenger, a wax such as a wax and a polyethylene wax, and a coloring agent are added to the paint.

[0024]

Next, the present invention will be described specifically with reference to examples.

(Example 1) As a substrate, a calcium silicate ceramic panel having a brickwork pattern with a sealer treated and a joint part forming a recess was prepared. However, the surface of the convex portion was finished flat. Then, a white two-component curable urethane paint using titanium oxide as a pigment was applied over the entire uneven surface of the substrate at 50 g / m ² and cured to form a base coat layer. Next, a moisture-curable polyurethane hot melt adhesive containing a linear urethane prepolymer having an excess isocyanate group at the end as a component is applied at 50 g / m ² only to the projections of large irregularities by a roll coater to form an adhesive layer. Was provided.

On the other hand, a polypropylene film having a thickness of 50 μm was used as a support sheet, a pigment comprising carbon black, iron oxide, titanium white, quinacridone, and isoindolidone, an acrylic resin and vinyl chloride-vinyl acetate copolymer. A brick-like pattern was printed as a decorative layer with an ink composed of a binder of a mixture of a combined resin and a weight ratio of 8: 2 to prepare a transfer sheet.

Then, the transfer sheet is placed so that the decorative layer surface faces the uneven surface of the substrate, and the surface temperature is 130 ° C.
Pressure was applied from the back with a silicone rubber heat roll having a rubber hardness of 65 °. The pressure was 10 kg / cm in linear pressure, and the feed speed of the hot roll was 15 m / min. After pressing, the support sheet was peeled off after cooling to room temperature. As a result, a decorative plate having the decorative layer transferred only to the convex portions of the base material was obtained. further,
A polyvinylidene fluoride paint containing a benzotriazole-based UV absorber was applied to a thickness of 10 μm on the decorative layer to form a transparent protective layer.

(Example 2) As the substrate, the substrate used in Example 1 was used in which the convex surface (brick portion) was further provided with a floral sculpture pattern (fine irregularities) by fine wire grooves. After the process up to the transfer of the decorative layer was performed in the same manner as in Example 1, ie, the process up to the step of peeling the support sheet was performed, the surface of the decorative layer was re-applied with a silicone rubber heat roll having a surface temperature of 130 ° C and a rubber hardness of 65 ° C. Pressed. Then, the same polyvinylidene fluoride paint as in Example 1 having a thickness of 10 μm was applied to the entire surface to form a transparent protective layer to obtain a decorative plate.

(Comparative Example 1) A decorative board was prepared in the same manner as in Example 1, except that a hot melt type adhesive composed of a vinyl acetate resin was used as the adhesive and the other conditions were the same.

Comparative Example 2 A decorative board was prepared under the same conditions as in Example 1, except that a two-part curable polyurethane adhesive comprising a reaction equivalent mixture of acrylic polyol and hexamethylene diisocyanate was used as the adhesive.

(Comparative Example 3) In Example 2, a decorative plate was produced under the same conditions except that the step of pressing the decorative layer again was omitted.

(Evaluation of Performance) After the decorative plates obtained in each of the above Examples and Comparative Examples were left in an atmosphere of 25 ° C. and 60% RH for one day, a notch extending from the transparent protective layer side to the adhesive layer was cut vertically. Eleven pieces and eleven pieces were inserted orthogonally, and a total of 100 grids were cut. Next, a test of attaching and peeling an adhesive surface of a cellophane adhesive tape having a width of 25 mm (Nichiban Cellotape (registered trademark), industrial use) to the surface of the grid was repeated five times, and the test was performed without peeling off the base material side. The evaluation result when the number of meshes of the remaining decoration layer was N (0 ≦ N ≦ 100, 100-N is the number of stripped meshes) was evaluated as N / 100. The value of this cellophane tape peel test is 10
It can be considered that the closer to 0/100, the better the adhesion between the decorative layer and the substrate. For comparison of the curing time, the decorative board of Comparative Example 2 was at 40 ° C. and 60% RH.
The same test was conducted on the test pieces cured in an atmosphere for three days. In addition, the occurrence (deletion) of the decoration layer transferred to the convex portion and the occurrence of burrs at the end of the transfer region (convex portion)
The evaluation was performed at a portion other than the portion where the peeling test was performed. Table 1 shows the evaluation results.

[0033]

[Table 1]

As can be seen from Table 1, according to the embodiment, the decorative layer does not come off and burrs do not occur.
Moreover, the result of the peeling test was also good.

[0035]

As described above, according to the present invention,
The initial adhesive strength of the moisture-curable hot-melt adhesive used to transfer the decorative layer to the projections of the decorative plate with irregularities on the surface is high, which may cause pattern missing and burrs during transfer. Absent. In addition, after a sufficient time has passed, the adhesive strength is greatly improved, so that the surface properties of the decorative layer such as adhesion (adhesive strength) and abrasion resistance are also good. Also, the time required for complete curing is shorter than that of a two-component cured polyurethane.

Then, after the support sheet of the transfer sheet is peeled off, a step of pressing with a roll is further performed, so that the convex portions of the substrate having the large irregularities on the surface are reduced to the portions having the minute irregularities. Good transfer can be achieved without floating of the decorative layer and poor adhesion.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state in which a base coat layer is formed on a surface of a substrate having an uneven shape.

FIG. 2 is a cross-sectional view showing a state in which an adhesive layer is provided only on the convex portions of the unevenness.

FIG. 3 is a sectional view of a transfer sheet.

FIG. 4 is a cross-sectional view illustrating a step of pressing a transfer sheet against a base material.

FIG. 5 is a sectional view of a decorative plate provided with a surface protective layer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base material 2 Base coat layer 3 Convex part 4 Adhesive layer 5 Support sheet 6 Decorative layer 7 Release layer 8 Transfer sheet 9 Heat roll 10 Surface protective layer

Claims (4)

[Claims] 1. A method of manufacturing a decorative board comprising transferring a desired decorative layer to a base material having an uneven surface on a transfer sheet using a transfer sheet, wherein the adhesive is formed of a moisture-curable hot melt adhesive only on the convex portions of the uneven surface. A step of providing a layer, a step of placing a transfer sheet thereon and pressing while heating with a hot roll, and a step of peeling off the support sheet of the transfer sheet and transferring a desired decorative layer only to the convex portions of the substrate surface A method of manufacturing a decorative board. 2. The method for producing a decorative sheet according to claim 1, wherein the support sheet of the transfer sheet is peeled off and then further pressed by a roll. 3. A decorative plate comprising a cured layer of a moisture-curable hot melt adhesive on a convex portion of a substrate having irregularities on its surface, and a decorative layer laminated on the cured layer. 4. The decorative plate according to claim 3, wherein the projection has a fine uneven surface.