JPS591111B2 - Decorative board manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing decorative laminates, and more specifically to water resistance,
This invention relates to a method for producing a decorative board with excellent weather resistance and an elaborate printed pattern.

Conventionally, various types of base materials for decorative boards have been known, such as plywood, metal plates, and noncombustible boards, and appropriate designs are usually formed on these base materials by printing, painting, transfer, etc. It is widely used as a building material.

Recently, composite laminates with a sandwich structure, in which the core material is a thermoplastic resin and the surface material is metal, particularly aluminum foil, have become commercially available.

This composite laminate combines the characteristics of thermoplastic resin and aluminum foil, such as being lightweight as a structural material, having rigidity, good workability, water resistance, and corrosion resistance. It is attracting attention as a new base material for building materials due to its excellent resistance to various types of materials. However, at present, this composite laminate is only coated with a very simple two-component polyol-cured polyurethane paint, and technology is needed to increase the product value by adding more luxurious or elaborate patterns. development was desired. According to research such as the present invention,
Even when various known patterning methods are applied to the composite laminate, it has been found that it is extremely difficult to provide elaborate patterns without impairing the excellent functions of the base material.

In other words, in direct printing using the silk screen method,
Although it is relatively simple, it is not possible to perform sophisticated printing; multicolor printing is technically or process-difficult and is not suitable for mass production; gravure offset printing is suitable for mass production, but requires expensive gravure offset printing machines. requires
Moreover, an elaborate multicolor printing pattern cannot be obtained. Furthermore, in the sublimation transfer method of dyes, color unevenness may occur due to temperature unevenness during transfer, and since the dye is a dye, there are problems with weather resistance, heat resistance, water resistance, etc. In the method of hot-pressing molding decorative paper impregnated with a thermosetting resin, since the core material of the base material is a thermoplastic resin, there are drawbacks such as distortion caused by hot pressure. Furthermore,
The conventional method uses transfer paper to form elaborate printed patterns.
Printing patterns are simply printed using thermoplastic resin as a vehicle, and because they are not strongly bonded by chemical reactions, solvent resistance is insufficient, and transfer is achieved by applying a top coat layer. Protecting the layer still does not fundamentally improve this drawback. In view of the above-mentioned current situation, the present inventors conducted intensive research on a method for applying beautiful patterns without impairing the excellent performance of the composite laminate. Focusing on various properties such as excellent weather resistance, water resistance, and corrosion resistance of the film produced by the company, they discovered that the desired objective could be achieved by a combination of a specific base coat layer, transfer ink layer, and top coat layer, and completed the present invention. This is what I did.

That is, the present invention includes a step of applying a two-component polyol-cured polyurethane resin paint with an excess of hydroxyl groups as a base coat layer to the surface of a substrate, a step of heating if necessary, and a step of using a resin containing a functional group that reacts with isocyanate groups as a vehicle component. A step of overlapping a transfer paper on which a desired pattern layer has been formed on a base sheet using printing ink such that the base coat layer and the pattern layer are in contact with each other, and if necessary, at the same time as or at the same time as the overlapping step. Subsequently, the method includes the following steps: heat-transferring the pattern layer to the base coat layer, peeling off the base sheet, and applying a two-component polyol-cured polyurethane resin paint with an excess of isocyanate groups as a top coat layer and curing it. The present invention provides a method for manufacturing a decorative board.

As mentioned above, the method of the present invention is particularly effective in forming designs on composite laminates with a sandwich structure in which metal is the surface material and thermoplastic resin is the core material. A laminate of aluminum foil/thermoplastic resin/aluminum foil manufactured by Co., Ltd. is commercially available.

However, it is naturally possible to apply the method of the present invention to other substrates, such as plywood, metal plates, particle boards, resin plates or films, gypsum boards, slate plates, glass plates, composite substrates of these, thermal A molded plate using a curable resin may also be used. The two-component polyol-cured polyurethane resin coating used in the present invention is composed of a polyol component and a polyisocyanate component, which are known per se, and are mixed at the time of use.

Polyol components include acrylic polyols, polyester polyols, and polyether polyols. Polyester polyols are obtained by condensing polycarboxylic acids or their anhydrides with polyols. Typical polycarboxylic acids include adipic acid, glutaric acid, peric acid, sebacic acid, azelaic acid, and phthalic acid. Typical polyols include ethylene glycol, propylene glycol, butylene glycol, glycerol, trimethylolpropane, and pentaerythritol. Polyether polyols are those obtained by polyoxyalkylation of polyols, such as poly(oxyethylene) glycol, poly(oxypropylene) glycol, poly(oxyethylene) trimethylolethane, and poly(oxypropylene). ) diethylene glycol, etc. Furthermore, examples of the ataryl polyol include polymers obtained by known methods using hydroxyalkyl acrylate or methacrylate as a monomer component. As the polyisocyanate component, p-phenylene diisocyanate, biphenyl diisocyanate,
Tolylene diisocyanate, 3,3'-dimethyl-4,
4'-biphenylene diisocyanate, 1,4-tetramethylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethyl-1,6-hexylene diisocyanate, methylene bis(phenyl isocyanate), lysine methyl ester diisocyanate , isoborone diisocyanate and methylcyclohexyl diisocyanate, polyphenylene polymethylene polyisocyanate, and prepolymers having terminal isocyanate groups. The prepolymer having a terminal isocyanate group is a composition obtained by reacting a polyester or polyether having an active hydrogen at the terminal with an excess organic isocyanate. By setting the polyol component and polyisocyanate component in excess of the stoichiometric amount, a two-component polyol-cured polyurethane paint with an excess of hydroxyl groups can be obtained. It is preferable to select from a range of 1.05 to 1.40.

If there is too little hydroxyl group, there may be a problem in adhesion with the top coat layer in the subsequent step, while if there is too much, there may be a problem in adhesion with the base material. In the present invention, the two-component polyol-cured polyurethane resin material may be transparent, or may be colored to be transparent or opaque by adding pigments, fillers, and other additives according to the purpose by known means. can.

Further, this paint is applied as a base coat layer to the surface of the substrate by a known coating method such as a curtain flow coater, a roll coater, spraying, or brushing. The viscosity can be adjusted depending on the coating method selected, and in some cases it can be diluted with an appropriate solvent before use. In the present invention, the transfer paper may be a synthetic resin film such as polyester film or polyolefin film, a base sheet material such as aluminum foil, or high-quality paper, provided with a release layer as necessary, and an appropriate method such as offset printing or gravure printing. A desired pattern is formed using the following steps.

The vehicle component of the printing ink in this case contains a resin component that reacts with isocyanate groups, and examples of the resin component include acrylic polyols, polyether polyols, polyester polyols, and cellulose resins. In addition to the above-mentioned resin components, vehicle components of the printing ink in the present invention include vinyl resins, thermoplastic acrylic resins, thermoplastic polyester resins,
An olefin resin or the like can also be used in combination if necessary. Generally, the hydroxyl value of these vehicles is 5 to 50ηKOH/9, preferably 10 to 307V.
．． Set to K0H/9 range. Using these vehicles, pigments,
Colorants such as dyes and other necessary additives are added and kneaded to make printing ink. In the present invention, the isocyanate group-excessive two-component polyol-cured polyurethane resin paint applied as the top coat layer is one in which the polyol component and polyisocyanate component of the polyurethane paint used for the base coat layer as described above are blended.
The ratio of isocyanate group/hydroxyl group is about 1.05 to 1.40.

In the method of the present invention, the two-component polyol-cured polyurethane paint with excess hydroxyl groups has excellent adhesion to the base material, the transferability of printed designs to the base coat layer by this paint, and the hydroxyl groups remaining in the base coat layer and the transferred design layer. A decorative board that achieves the desired purpose can be obtained by chemically integrating the above and the excess isocyanate groups of the top coat layer.

The present invention will be explained in more detail below based on the drawings. 1 to 4 are cross-sectional views illustrating the method of implementing the present invention, and FIG. 5 is a cross-sectional view showing a composite laminate. FIG. 1 shows a base material 1 coated with a base coat layer 2, which is designated as A.

Although the base coat layer 2 is cured at room temperature, it is better to accelerate the curing by a known heating means such as applying hot air, infrared rays, far infrared rays, or the like. In this case, the degree of curing does not necessarily have to be complete. FIG. 2 shows a transfer paper B on which a desired pattern layer 4 is formed on a base sheet 3.

Although FIG. 2 shows a case where the pattern layer 4 is partially formed, there is no problem even if the pattern layer is formed on the entire surface.
FIG. 3 shows a series of steps in which the above A and transfer paper B are superimposed, heated and pressed at the same time, and the base sheet 3 is immediately peeled off. That is, the above A is preheated by the heater 5 as necessary and sent in the direction of the arrow,
On the other hand, the transfer paper B is sent out from the unwinding roll 6, passed through the wrinkle removing roll 7, and is superposed together with A between the transfer roll 8 and the impression roll 9, and the transfer roll 8 is heated by the heater 10. Therefore, they are heated at the same time as they are overlapped, the pattern layer 4 is transferred to the surface of A, and the base sheet 3 is wound up on a winding roll 11. In the present invention, a series of steps as shown in FIG. 3 are used to describe an embodiment that is industrially most convenient in that it involves overlapping, heat-pressing, and peeling off the base sheet. Therefore, each process may be divided as appropriate. FIG. 4 is a cross-sectional view of a final product, a decorative board, on which a transparent two-component polyol-cured polyurethane resin paint rich in isocyanate groups is applied as the top coat layer 12.

This paint partially penetrates into the pattern layer 4 and the base coat layer 2 and chemically reacts with the remaining hydroxyl groups, thereby making it possible to integrate them. The method for applying the top coat layer is not particularly limited, and any known method, such as the above-mentioned method for applying the base coat layer, can be employed as appropriate. Although the curing method may take a long time even at room temperature, a method using appropriate heating means is generally adopted. FIG. 5 is a cross-sectional view of the composite laminate having the sandwich structure, in which the metal foil 13
A thermoplastic resin 14 is laminated therebetween as a core material.

Even when such a laminate is used as a base material, if a decorative board is manufactured by the method of the present invention, the thermoplasticity of the base material can be improved by heating during transfer, drying of the base coat resin and top coat resin, and heating during curing. Since there is no problem of softening or deformation of the resin, a decorative board with good design and dimensional stability can be obtained. The decorative board obtained by the method of the present invention described above can be used for various purposes,
For example, wall covering materials, ceiling materials, flooring materials, furniture, cabinets, etc.
It can be applied to bathtub aprons, bath unit interior materials, etc.

In the present invention, since the pattern layer is formed by transfer, there is an advantage that gravure printing, which facilitates precise multicolor printing, can be applied to the transfer sheet used therein.

In addition, a two-component polyurethane with excess hydroxyl groups is used as the resin for the base coat layer to improve adhesion to the base material, and the resin for the pattern layer is a resin containing hydroxyl groups that reacts with isocyanate groups, and the resin for the top coat layer is a resin containing isocyanate groups. By using an excess of two-component polyurethane, the top coat layer, base coat layer, and pattern layer are chemically bonded to increase adhesion and become integrated with the base material, making it suitable for use in humid environments or areas with a lot of moisture. Even if the polyurethane coating is damaged, peeling does not occur between the layers over time, and this combined with the properties of the polyurethane coating itself, which is excellent in various resistances such as weather resistance and corrosion resistance, results in an extremely strong and beautiful decorative board. Next, the present invention will be described in more detail with reference to Examples. Example 1 22 parts of acrylic polyol resin (hereinafter expressed in parts by weight), vinyl chloride and vinyl monoacetate were printed using a gravure printing machine using coated paper coated with polyamide and a release agent as a base sheet on high-quality paper with a basis weight of 709/wl. Using a resin composition consisting of 72 parts of copolymer resin and 6 parts of cellulose resin as Vihtar and gravure printing ink consisting of pigment, extender pigment, ink additive, and solvent, a three-color printed pine straight-grain pattern was created. Print in the reverse order of the normal printing order, and finally print 150 lines 60μ
Transfer paper was prepared by performing colored solid printing with opacity using a solid plate.

On the other hand, planium grade #2100 soil was used as the base material.
22 parts of acrylic polyol resin containing 15% excess hydroxyl groups than the chemical equivalent, 5 parts of hexamethylene diisocyanate prepolymer, 20 parts of titanium white,
An acrylic urethane paint consisting of 53 parts of solvent and trace amounts of paint additives (leveling agent, curing catalyst, etc.) is prepared and applied as a base coat layer by airless automatic spraying to a dry film thickness of 25 to 30 microns. The base coat layer was cured by heating and drying for 6 minutes in a far-infrared oven set at a substrate temperature of 110° C. or lower, and then allowed to cool.

Next, the substrate on which the base coat layer was applied was heated to a substrate temperature of 80° C. using a far-infrared heater attached to the transfer machine.
Under these conditions, the pattern on the transfer paper is heated to a rubber hardness of 70 (JIS hardness A) using the attached heater using the transfer machine shown in Fig. 3, and under the condition that 8'C is maintained. It was continuously transferred onto the surface of the base coat layer. Unlike in FIG. 3, the base sheet was not peeled off until the next step and was left to play the role of surface protection. Next, after peeling off the base sheet of the transfer paper to expose the ink surface transferred to the base material,
33 parts of acrylic polyol resin in which isocyanate groups are blended in an excess of 25% over the chemical equivalent, 7 parts of hexamethylene diisocyanate-based prepolymer, 60 parts of solvent,
An acrylic urethane paint containing a trace amount of paint additives was prepared, and a dry film thickness of 15 mm was prepared using the same equipment as for the base coat layer.
The coating was coated to a thickness of 20 to 20 microns, dried by heating, reacted and cured, and then allowed to cool.

Through the above process, a planium decorative board with a straight-grain pine pattern on the surface was obtained.

The results of performance tests on this product are summarized in Table 1. Example 2 On the same base sheet as in Example 1,
A three-color rosewood pattern was printed using printing ink of a similar composition and a transfer paper was prepared in the same printing order.

However, colored solid printing was not performed. The same base material as in Example 1 has a hydroxyl value of 50T with 15% excess of hydroxyl groups than the chemical equivalent! f! KOH/9 acrylic polyol resin 22
Part, hexamethylene diisocyanate prepolymer 5
parts, titanium white 10 parts, red iron oxide 10 parts, solvent 53 parts
A brown acrylic urethane paint consisting of a small amount of paint additives and a paint additive was prepared, and a dry film thickness of 2
After the transfer, the base sheet was peeled off in the same manner as in Example 1, and then an acrylic film having a hydroxyl value of 30ηKOH/9 and containing isocyanate groups in excess of 25% of the chemical equivalent was coated to a thickness of 0 to 30 microns. A matte and transparent acrylic urethane paint was prepared consisting of 33 parts of polyol resin, 7 parts of hexamethylene diisocyanate prepolymer, 4 parts of matting agent (silica), 56 parts of solvent, and a trace amount of paint additive. In the same manner as above, a planium decorative board with a matte rosewood pattern on the surface was obtained.

The results of performance tests on this product are summarized in Table 1. Example 3 A planium decorative board with a straight-grained pine pattern on the surface was obtained using a printing ink containing a resin composition having the composition shown below as a vehicle component, but in the same manner as in Example 1. .

The results of performance tests on this product are summarized in Table 1. Acrylic polyol resin 22 parts Thermoplastic acrylic resin 72 parts Cellulose resin 6 parts Example 4 A veneer with a pine straight-grain pattern was made in the same manner as in Example 1 except that the base material was a galvanized steel sheet with a thickness of 0.6 mm. A steel plate was obtained.

The results of performance tests on this product are summarized in Table 1. Comparative Example 1 A branium decorative board with a straight-grained pine pattern on the surface was prepared using a printing ink whose vehicle component was a resin composition having no hydroxyl group as shown below, but in the same manner as in Example 1. was gotten.

The results of performance tests on this product are summarized in Table 1. Vinyl acetate vinyl monochloride copolymer resin 100
Comparative Example 2 Using the same printing ink as in Comparative Example 1 and in the same manner as in Example 2, a planium decorative board with a rosewood pattern on its surface was obtained.

The results of performance tests on this product are summarized in Table 1.

[Brief explanation of the drawing]

1 to 4 are cross-sectional views for illustrating the method of carrying out the present invention, and FIG. 5 is a cross-sectional view for illustrating a composite laminate. The main symbols in the diagram are as follows. 1... (material, 2... base coat layer,
4...Design layer, B...Transfer paper, 8...
...Transfer roll, 12...Top layer, 1
3... Metal foil, 14... Thermoplastic tree a
layer.

Claims (1)

[Claims] 1 A step of applying a two-component polyol-cured polyurethane resin paint with an excess of hydroxyl groups as a base coat layer to the surface of the substrate, a heating step if necessary, and a printing ink whose vehicle component is a resin containing hydroxyl groups that reacts with isocyanate groups. A step of overlapping a transfer paper on which a desired pattern layer has been formed on a base sheet so that the base coat layer and the pattern layer are in contact with each other, and if necessary, applying the pattern layer at the same time as or following the overlapping step. A decorative laminate comprising the following steps: heat-transferring the base coat layer, peeling off the base sheet, and applying a two-component polyol-cured polyurethane resin paint containing an excess of isocyanate groups as a top coat layer, and curing the coating. Manufacturing method.