JPH0211315B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved method of manufacturing decorative laminates having recesses.

Several methods are known for forming recesses, particularly recesses that match a printed pattern, in a thermosetting resin decorative board, such as a melamine decorative board or a diallyl phthalate decorative board. In particular, the method using a printing method is extremely easy because the location where the concave portion is to be provided and the other pattern are matched in the printing process, and moreover, it has a surface shape that matches the other methods, especially the printed pattern. Compared to a method using a mold or the like, this method is industrially superior because most of the normal steps after printing can be used as they are. As a method using such a printing method, the present applicant has previously produced impregnated paper using a decorative base paper on which a foamed printing layer and other printed patterns are provided using heat-foamable ink, and then the impregnated paper. A method for manufacturing a three-dimensional decorative board using paper by heating and pressure molding is disclosed (Japanese Patent Application Laid-Open No. 111554/1983). This method applies conventional printing plates and printing methods to form recesses that match the printed pattern, and although it uses a special heat-foaming ink, it can be used under normal printing press operating conditions. This is a method using ink, in which the thermosetting resin around the foamed part causes poor curing, and only this part is taken up by a mirror plate, etc., and becomes partially matted or recessed. However, in such a method, uncured resin adheres to the mirror plate, so
If the same mirror plate is used for heating and pressure molding without removing it, the surface of the product will become uneven. To avoid uneven gloss, the mirror plate must be washed every time, or heat-resistant It is complicated to insert a disposable sheet with a smooth surface between the mirror plate and the decorative board during the heat-pressing molding process, and the time required for the heat-pressing molding process, which takes a long time for one cycle (usually around 10 to 20 minutes), is complicated. If this is undesirable as it will cause further extension, or the coating thickness of the foaming pattern or the content of the foaming agent may be adjusted to prevent the foaming of the foaming pattern from reaching the surface to prevent uncured resin from being removed on the mirror plate. This reduces the feeling of depression, which is also undesirable, and the method of controlling the coating thickness is difficult due to changes in printing conditions such as speed, printing pressure, ink viscosity, etc. during printing.

As a result of repeated research to eliminate the above-mentioned drawbacks of the invention described in the above-mentioned publication, the present inventor found that the following differences occur due to differences in heating and drying conditions when creating impregnated paper. .

(a) When the heating temperature is lower than the foaming temperature of the foaming agent in the foamable print layer, a large amount of uncured resin adheres to the mirror plate during the subsequent heating and pressure treatment.

(b) When the heating temperature is higher than the foaming temperature of the foaming agent in the foamable printed layer, virtually no uncured resin adheres to the mirror plate during the subsequent heating and pressure treatment; however, the recesses that are formed The depth is shallow or it is simply matte.

In the case of (b) above, the foamable printing layer has already foamed at the time the impregnated paper is created, and it is observed that convex portions are formed on the resin surface of the impregnated paper.
It may seem as if it easily adheres to the mirror plate during heating and pressure treatment, but the reality is different. The reason for this is that in case (b), the surface of the convex part of the impregnated paper is coated with a resin that has been dried from the impregnated thermosetting resin liquid, so the foamed print of the convex part occurs during the heating and pressure treatment. This is because the layer does not directly touch the mirror plate, and the printed layer is bulky and lacks strength, so it is easily compressed by heating and pressure treatment. or,
The reason why there is a large amount of uncured resin adhering to the mirror plate in (a) above is that the foamable printing layer on the impregnated paper in (a) has not lost its foaming ability and expands rapidly during the heating and pressure treatment. This is because when the resin of the impregnated paper becomes fluid during expansion, it is easily pushed away and adheres closely to the mirror plate.

Based on the above findings, the present inventor has conducted further studies and found that by controlling the heating and drying conditions of the impregnated paper, it is possible to prevent the foamable printing layer from adhering to the mirror plate during the heating and pressure treatment. This is the heading that led to the present invention.

Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a sectional view showing the structure of the decorative paper 4 according to the present invention. First, the decorative base paper 1 is a paper commonly called titanium paper that is used for ordinary melamine decorative boards and diallyl phthalate decorative boards, such as paper that uses purified pulp and contains a large amount of titanium oxide etc. You can use any of them if you have them.

Next, a normal printing layer 2 with a desired pattern is formed on the decorative base paper 1 using normal printing ink, and then a foamable printing layer 3 with a desired pattern is formed using heat-foamable printing ink to form the decorative paper. Create.

As ordinary printing ink, one prepared using an appropriate vehicle can be used, but
Those with good impregnability with the thermosetting resin liquid described below are preferable, and preferable examples include cellulose derivatives such as ethyl cellulose, ethyl hydroxyethyl cellulose, cellulose acetate propionate, nitrocellulose, and cellulose acetate, and butyral resin. can. In order to form the normal printing layer 2 with a desired pattern using normal printing ink, gravure printing, gravure offset printing, lithographic offset printing, die-line printing, intaglio printing, jet printing, silk screen printing,
This can be carried out by a known printing method such as electrostatic printing, and in particular, to form a regular printing layer with a wood grain pattern, a gravure printing plate that can continuously (endlessly) make a wood grain pattern is used. Gravure printing, gravure offset printing, rotary screen printing, etc. are preferred, but are not limited thereto.

As the heat-foamable printing ink, one obtained by adding a known foaming agent to a printing ink using an appropriate vehicle can be used, and suitable vehicles include those mentioned above as an example of a vehicle for ordinary printing ink. In addition to resins, acrylic or methacrylic resins alone such as styrene resins such as polystyrene and polyα-methylstyrene, styrene copolymer resins, polymethyl methacrylate, polyethyl methacrylate, polyethyl acrylate, and polybutyl acrylate Or copolymer resin, rosin, rosin-modified maleic acid resin, rosin-modified phenolic resin,
Rosin ester resins such as polymerized rosin, polyvinyl acetate resins, coumaron resins, vinyltoluene resins,
One or more of vinyl chloride resin, polyester resin, polyurethane resin, butyral resin, polyamide resin, vinyl chloride-vinyl acetate copolymer resin, etc. is used, and the blowing agent is bicarbonate, which is a known blowing agent. sodium, ammonium carbonate,
Inorganic blowing agents such as sodium boron hydride and silicon oxyhydride, azodicarbonamide, azobisisobutyronitrile, dinitrosopentamethylenetetramine, paratoluenesulfonyl hydrazide, 4,4-oxybisbenzenesulfonylhydrazide, etc. organic blowing agents, and furthermore,
Microballoons (or microspheres), which are gases or low-boiling organic solvents encapsulated in synthetic resin capsules, are selected according to the softening temperature of the vehicle, the processing conditions of the decorative paper, etc., and used. In addition to vehicles and foaming agents, colorants for dyes and pigments, plasticizers, stabilizers, surfactants, waxes and greases, desiccants, auxiliary desiccants, curing agents, emulsifiers,
Thickeners, fillers, dispersants, solvents and diluents are added as appropriate, and the mixture is kneaded and used. As a method for forming the foamable print layer 3 with a desired pattern using the heat foamable ink as described above, there may be mentioned a known printing method similar to the method for forming the normal print layer 2 described above. A method using a printing method that transfers a relatively large amount of ink during printing is preferable because the pattern is raised due to foaming, and in that sense, gravure printing, gravure offset printing, intaglio printing, or silk screen printing are preferable. preferable. In addition,
When a wood grain pattern is formed as a normal printing layer, a wood grain conduit groove pattern is printed as a foamable print layer, and a recess is created in the conduit groove pattern in a post-process, the woodgrain pattern that is the normal print pattern and the foamable print layer are used. It is preferable that certain wood grain conduit groove patterns be formed by the same printing method because they can be formed using the same printing machine, and the two patterns can be easily adjusted.
In addition to the above-mentioned wood grain conduit groove pattern, the foamable printed layer 3 may also include a pattern of a part where a concave portion is desired to be formed within the pattern of the printed layer, for example, a tile joint,
It is preferable to use a printing plate made by removing a peeling groove in a tree, a crack in a stone, or a desired part of a material having a three-dimensional surface texture such as leather or cloth.

As described above, the decorative paper 4 is formed by forming two types of printing layers, that is, the normal printing layer 2 and the foamable printing layer 3, on the decorative base paper 1, and then the decorative paper 4 is impregnated with a thermosetting resin liquid. let As the thermosetting resin liquid, a known thermosetting resin used in manufacturing decorative boards, such as melamine resin, phenolic resin, diallyl phthalate resin, benzoguanamine resin, epoxy resin, or thermosetting modified vinyl chloride resin, is used. These resins can be dissolved in, for example, a suitable solvent or monomer, and a catalyst or the like may be added thereto to form a resin liquid, as required, and the resin liquid is coated and impregnated onto the decorative paper using a known coating method. The coating method can be gravure coating, roll coating, dip coating, or the like.

After the decorative paper is impregnated with the thermosetting resin liquid as described above, it is heated and dried, and the foamable printing layer is pre-foamed to reduce the foamability, thereby producing the impregnated paper 5. 6 in FIG. 2 indicates the impregnated and dried resin. Such heating and foaming conditions also depend on conditions such as the thickness of the decorative base paper, the type or amount of the vehicle and foaming agent of the heat-foamable printing ink constituting the foamable printing layer, the composition and coating amount of the thermosetting resin liquid, etc. Although it varies, depending on the foaming temperature of the foaming agent used, the time required for the foamable pattern of the impregnated paper to completely foam at that temperature is 20 to 80%, preferably 30 to 50%, or 10-80% of the fully foamed thickness of the printing layer, preferably
It can be obtained by adjusting the foaming conditions of temperature and time so that the thickness is 20 to 70%.

As an example, the foaming temperature for titanium paper with a basis weight of 80g/ ^m2
When forming a foam printing layer with a thickness of 15 to 20 μm using an ink containing 20 parts by weight of a capsule-type foaming agent at 120°C and 25 parts by weight of a butyl methacrylate resin vehicle, the heating time at a temperature of 120°C is
It foams completely in 90 seconds and reaches a thickness of 80 to 100 μm, but
In this case, heat at the same temperature for 25 to 45 seconds.
A foaming ratio of 40 to 60 μm is obtained, and when decorative paper is produced in a subsequent process using the impregnated paper obtained in this time range, the resin does not adhere to the mirror plate, but the foamable printing layer foams and is very close to the surface. However, if the resin is used for less than 25 seconds, the resin will adhere to the mirror plate, and if it exceeds 45 seconds, the foaming properties will decrease and foaming will not be sufficient in the subsequent process.
Even with solvent coating and polishing, sufficient recesses are not formed. Alternatively, instead of heating at 120°C for 25 to 45 seconds, it is preferable to heat at a temperature lower than 120°C, since the required heating time will be longer and the heating time will be less susceptible to setting errors; for example, in the above example. When heated at 100℃ for 7 to 15 minutes, it heats at 120℃.
A similar effect can be achieved by heating for 27 to 45 seconds.

The impregnated paper 5 is formed as described above, and the obtained impregnated paper 5 is then heated and pressed together with the base material 7 as shown in FIG. 3. The base material 7 may be, for example, a core paper made by stacking several sheets of paper with a basis weight of 140 to 180 g/m ² impregnated with 40 to 50% phenol resin, or a wood base such as wood, plywood, or particle board. Gypsum board, gypsum base materials such as gypsum slag board, fiber cement board such as pulp cement board, asbestos cement board, wood chip cement board, GRC
Also usable are concrete, metal foils or sheets of iron, aluminum, copper, etc., and composites of the above base materials.

In particular, when applying the method of the present invention to a melamine decorative board, the structure for producing a normal melamine decorative board, for example, a core paper (basis weight 140 g/m ² - 180
g/m ² ) impregnated with 40 to 50% phenolic resin depending on the required thickness, and balance paper (basis weight 80 g/m ² ) impregnated with 60% melamine resin in the order listed above. I'll turn around and go. In the present invention, it is preferable not to use overlay paper, which is used in general melamine decorative boards, because it prevents the formation of recesses. Alternatively, for the purpose of combining the effect of recessed portions and abrasion resistance, decorative paper is impregnated with a melamine resin solution containing known wear-resistant particulates, and the decorative paper thus obtained is used. , abrasion resistance is improved without the use of resin-impregnated overlay paper.

After the impregnated paper is combined with the base material and, if necessary, other materials as described above, a heating and pressure treatment is performed to integrate the impregnated paper, the base material, and the others. The heating and pressurizing treatment is carried out using a conventional press machine as shown in FIG. 3, using a pair of heated surface plates 8 and 8' and a pair of mirror plates 9 and 9'. The heating and pressurizing conditions depend on the type of decorative board, the type of base material,
The conditions may vary depending on the thickness of the material, etc., but normal conditions can be used as they are. For example, for melamine decorative boards, especially high-pressure melamine decorative boards, the heating temperature is 130 to 150°C, the pressure is 80 to 12 Kg/ ^cm2 , and the time is 10.
-20 minutes, and for low-pressure melamine decorative boards, heating temperature is 140-190℃, pressure is 10-20Kg/ ^cm2 , time is 1-20 minutes.
For diallylphthalate decorative boards, the heating temperature is 125-140°C, the pressure is 10-20 kg/cm, and the heating time is ² hours and 5-15 minutes.

As a result of the heating and pressure treatment described above, the foamable printing layer of the impregnated paper foams and exerts pressure on its surroundings. Therefore, even though it is pressurized by a press etc., its volume is almost unchanged without being compressed. maintained,
From the decorative base paper surface of the impregnated paper to the decorative board surface,
A foamed layer is formed by foaming the foamable printing layer, and since the foaming properties have been reduced by pre-foaming, the resin near the surface of the impregnated paper is pushed away as foaming progresses, making it impossible for it to directly adhere to the mirror plate. The solvent that will be described later is likely to penetrate into areas where foaming occurs.

Next, a solvent is applied to the entire surface of the decorative board having the foam layer. The solvent to be used is one that dissolves or swells the foam layer, and more specifically, a solvent that dissolves or swells the heat-foamable ink vehicle or the microballoons constituting the foam print layer is appropriately selected and used. For example,
It can be selected from aromatic hydrocarbons such as toluene and xylene, ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate and n-butyl acetate, and alcohols such as methanol, ethanol and isopropanol.

These solvents may be applied to the decorative board by any application method such as roll coating, spray coating, pour coating, flow coating, or spraying.

After applying a solvent to the entire surface of the decorative board to dissolve or swell the foam layer as described above, the entire surface is polished using a buff roller or a brush to remove the foam layer portion, as shown in FIG. As shown in FIG. 2, a recess 10 is formed in a portion of the decorative paper corresponding to the foamable printing layer.

The present invention consists of the configuration as explained above,
Therefore, compared to conventional methods, there is no need to wash and remove uncured resin adhering to the mirror plate during heating and pressure treatment, or to insert and remove a sheet to prevent uncured resin from adhering to the mirror plate. Furthermore, since the time required for these processes can be eliminated, the time for one cycle of heating and pressurizing treatment can be shortened to the necessary minimum, and it is also possible to reduce the time required for one cycle of heating and pressurizing treatment to the necessary minimum. too,
The more aggressive method of the present invention, which involves dissolution or swelling with a solvent and subsequent removal, can remove the foam layer more completely, making it possible to form recesses more reliably and sharply and clearly. It is suitable for thermosetting resin decorative boards with a wood grain pattern in which conduit grooves are formed as recesses in the wood grain pattern, and it is suitable for use in recesses such as tile joints, beading grooves, and stone cracks. It is also suitable for expressing textures such as leather and textiles.

Examples for explaining the present invention more specifically are listed below.

Example 1 A wood grain pattern was printed on the surface of base paper for decorative laminates containing titanium oxide having a basis weight of 80 g/m ² by gravure printing using ordinary gravure inks of various colors having the following composition.

Composition of ordinary gravure ink Cellulose acetate 5-6% by weight Color pigment 15-35% by weight Dibutyl phthalate 2-3% by weight Solvent (2) 56-78% by weight However, in the above composition, the solvent (2) has the following composition.

Solvent () Methanol 15% by weight Ethyl acetate 60% by weight Xylene 15% by weight Cyclohexanone 10% by weight Next, a wood grain conduit groove pattern was printed in synchronization with this wood grain pattern by gravure printing using a heat-foamable gravure ink having the following composition. .

Composition of heat-foamable gravure ink: Butyl methacrylate resin 25% by weight Foaming agent (Matsumoto Yushi Pharmaceutical Co., Ltd. Micropearl F-30)
20% by weight Colored pigment 5% by weight Diphenyloctyl phosphate 1% by weight Solvent () 49% by weight However, in the above composition, the solvent () has the following composition.

Solvents () Toluene 35% by weight Normal hexane 45% by weight Isopropanol 20% by weight The decorative paper obtained above was coated with a melamine resin solution having the following composition using a normal impregnating machine to give an impregnated amount of 90 g/cm ² when dried. It was impregnated so that

Melamine resin solution Melamine formaldehyde resin 50% by weight Water 45% by weight Isopropanol 5% by weight Next, the mixture was dried for 10 minutes in a dryer at a temperature of 100°C±2°C to obtain impregnated paper.

The obtained impregnated paper was layered on top of four sheets of ordinary phenolic resin-impregnated core paper, and heated and heated using a press at a heating temperature of 135°C, a pressure of 100 kg/cm ² , and a time of 10 minutes. When pressurized, cooled to room temperature, and then taken out, a decorative board was obtained in which the surface corresponding to the wood grain conduit groove pattern became somewhat matte, and ethyl acetate was further applied to the surface of the decorative board at a rate of 10 g/ ^m2 . When the surface was immediately polished using a buff roller, the portion corresponding to the wood grain conduit groove was removed by polishing.
A decorative board was obtained in which the removed traces became recesses. In this example, the resin in the conduit groove portion did not adhere to the press surface.

Example 2 Same as Example 1, except that the foaming agent in the heat-foamable gravure ink was Microvar manufactured by Matsumoto Yushi Seiyaku Co., Ltd.
Decorative paper was created by changing to RQ-507, and the resulting decorative paper was impregnated with a normal fast-curing melamine resin solution with the following composition using a normal impregnation machine, and the dry coating amount was 108
Impregnated to a concentration of g/m ² at a temperature of 100℃±2℃
It was dried for 10 minutes to create impregnated paper.

Next, the above-mentioned impregnated paper was layered on a 15 mm thick particle board with the pattern facing up, and then heated and pressured at a pressure of 20 kg/cm ² and a heating temperature of 150°C for 8 minutes to integrate them. Then, in the same manner as in Example 1, a decorative board having concave portions was obtained.

Fast-curing melamine resin solution Melamine formaldehyde resin (Santop M-700 manufactured by Nissan Chemical Co., Ltd.) 100 parts by weight of curing agent (same as above, AA-1) 0.35 parts by weight of curing agent (same as above, AA-2) 0.05 parts by weight of penetrant ( Same as above, MA) 1.31 parts by weight Example 3 A decorative paper was prepared in the same manner as in Example 2, and a thermosetting resin liquid of the following composition was added to the obtained decorative sheet so that the dry impregnation amount was 120 g/ ^m2. An impregnated decorative sheet was prepared by impregnating the sheet and drying it for 10 minutes at a temperature of 100°±2°C.

Thermosetting resin liquid diallyl phthalate prepolymer 100 parts by weight Benzoyl peroxide 3 parts by weight Internal mold release agent 0.5 parts by weight Heavy inhibitor (hydroquinone) 0.01 parts by weight Methylated silica (diameter 16 mμ) 3 parts by weight Acetone 150 parts by weight This impregnation The decorative sheet was layered on a particle board with a thickness of 15 mm, and heated and pressure molded using a mirror-finished duralumin board at a pressure of 20 kg/cm ² at 130°C for 15 minutes, so that the conduit pattern part was slightly larger than the surrounding area. A matching embossed diallyl lid notebook decorative board was obtained which was matte and slightly concave. Note that the resin of the conduit portion did not adhere to the duralumin board.

Furthermore, when 10 g/m ² of ethyl acetate was applied to the above decorative board using a roll coater and the surface was polished with a buff roller, the conduit pattern was further recessed.
A decorative board with a three-dimensional effect was obtained.

[Brief explanation of drawings]

Figures 1 to 3 are cross-sectional views showing each process of the present invention, where Figure 1 is decorative paper, Figure 2 is impregnated paper, and Figure 3 is
The figure shows the heating and pressurizing treatment process, and FIG. 4 shows the decorative board obtained in the present invention. 1... Decorative base paper, 2... Normal printing layer, 3... Foaming printing layer, 4... Decorative paper, 5... Impregnated paper, 6...
...Resin, 7...Base material, 8,8'...Press, 9,
9'...Mirror plate, 10...Recessed portion.

Claims (1)

[Claims] 1. A normal printing layer with a desired pattern was formed on decorative base paper using normal printing ink, and then a foamable printing layer with a desired pattern was formed using heat-foamable printing ink, which was formed as described above. After impregnating decorative paper with a thermosetting resin liquid, it is heated and dried, and the foamable printing layer is pre-foamed to create impregnated paper, and the impregnated paper is combined with a base material and then heated and pressure molded. 1. A method for producing a decorative board having recessed portions, which comprises applying a solvent to the entire surface after treatment, and then removing the foam layer formed by foaming the foamable printed layer.