JPS6137106B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a decorative board having excellent cigarette resistance and having a resin-coated cured thin paper as a surface layer.

Conventionally, pre-coated decorative laminates using thin paper have been produced by applying a small amount of urethane resin, amino alkyd resin, etc. to wood-grain printed or monochrome printed thin paper and curing it. Products that are bonded to a base material through an adhesive are produced in large quantities. Although this decorative board is low in price and very economical, the surface resin layer of the decorative board is very thin, so the surface properties are not sufficient, so it cannot be used for durable walls in buildings or for furniture. It could not pass the FW type of the Uru JAS special plywood standard, and in terms of cigarette resistance, surface faults were easily burned and peeled off.
In some cases, the burn even reached the base material.

On the other hand, decorative boards with a thick surface resin layer, which is made by impregnating ordinary decorative paper cloth with melamine resin or diallyl phthalate resin and curing it under heat and pressure, which is inferior in economic efficiency to the above-mentioned printed decorative boards, have excellent surface properties. However, they did not necessarily have sufficient properties in terms of the above-mentioned cigarette resistance. In other words, when a lit cigarette is placed on these decorative boards, the surface layer becomes noticeably scorched within 1 to 2 minutes, and if left for even longer, cracks appear in the surface resin layer.
Moreover, the resin layer often peeled off.

The inventor of the present invention complies with the JAS special plywood standard in the production of decorative laminates whose surface layer is resin-coated hardened tissue paper.
As a result of intensive research in order to obtain a decorative board that satisfies the FW type and satisfies the cigarette resistance, we used a thermosetting resin composition containing diallyl phthalate monomer as the coating resin, applied it and cured it. A decorative board that satisfies the above requirements can be obtained by laminating cured paper having a surface resin layer of a certain thickness on a base material and integrating the adhesive using an adhesive containing aluminum powder as an adhesive. This discovery has led to the completion of the present invention.

That is, in the present invention, a thermosetting resin composition containing a diallyl phthalate monomer is coated on a thin paper and cured, and the surface resin layer has a thickness of 10 to 40 microns. This is a method for producing a decorative board with excellent cigarette resistance, which is characterized by being integrated with a base material.

As the coating resin composition used in the present invention, a thermosetting resin composition containing a diallyl phthalate monomer is suitable. The diallyl phthalate monomer may be any of the ortho, iso, and tele isomers. Further, as the thermosetting resin, diallyl phthalate prepolymer, unsaturated polyester resin, acrylic urethane resin, urethane resin, etc. are used. In particular, an air-curable unsaturated polyester resin alone or a mixture with another resin containing the resin as one component is preferred from the viewpoint of producing cured paper. Such air-curable unsaturated polyester resins include aliphatic cyclic unsaturated polybases such as tetrahydrophthalic acid, 3,6-endomethylenetetrahydrophthalic acid, and methyl-3,6-endomethylenetetrahydrophthalic acid as acid components. Acids and mixed acids with unsaturated polybasic acids such as maleic acid, fumaric acid, itaconic acid, citraconic acid, phthalic acid, succinic acid, and adipic acid, and saturated polybasic acids, and alcohol components such as ethylene glycol, diethylene glycol, propylene glycol, etc. Polyesters produced from the above-mentioned unsaturated polybasic acids, saturated polybasic acids, the above-mentioned aliphatic polyhydric alcohols and allyl glycidyl ether, and the like are exemplified.

The proportion of diallyl phthalate monomer and thermosetting resin in the resin composition of the present invention is suitably in the range of 5 to 60% by weight based on the total amount thereof. If the content of diallyl phthalate monomer is less than 5% by weight, satisfactory results cannot be obtained in the surface properties of the decorative board;
If the curing time is exceeded, the time required for curing becomes longer, and the shrinkage during curing is significant, making it difficult to suppress the occurrence of wrinkles in the cured paper.

A curing catalyst depending on the resin used is added to the resin composition of the present invention. In addition, if necessary, a curing accelerator,
Various additives such as polymerization inhibitors, internal lubricants, viscosity imparting agents, leveling agents, and anti-shrinkage agents can be added.

As the resin-coated cured thin paper of the present invention, a cured paper with a surface resin layer having a thickness of 10 to 40 microns is used, which is obtained by coating a thin paper with the above-mentioned resin composition and curing it. Thin paper having a basis weight of 20 to 55 g/m ² is suitable, and may be printed or untreated. Furthermore, the thin paper may be treated to adjust the permeability of the resin, and the thin paper may be treated with a resin to increase the strength between the sheets. Thin paper with a basis weight of less than 20 g/m ² is undesirable because the strength of the paper itself is low, causing problems in workability when producing hardened paper, and poor hiding power as decorative paper. In addition, if the basis weight exceeds 55g/ ^m2 , the permeability of the coating resin into the paper will increase, and the amount of resin deposited on the surface of the cured paper will be relatively reduced, so the surface characteristics as a decorative board will not be sufficient. This is not preferable because the cured paper itself is not flexible and the flexibility of the cured paper itself is deteriorated. The manufacturing method of hardened paper is as follows:
Although it is convenient to use the method described in JP-A No. 55-57098, which was filed by the applicant earlier, the resin composition of the present invention is not limited to this method. Any hardened paper with a surface resin layer thickness of 10 to 40 microns may be used.

If the thickness of the surface resin layer of the cured paper is less than 10 microns, sufficient surface properties as a decorative board cannot be obtained, and therefore the paper cannot pass the JAS FW standard.
Furthermore, if the thickness of the surface resin layer exceeds 40 microns, the flexibility of the cured paper itself deteriorates, and the cured paper is significantly deformed due to curing shrinkage of the resin during production of the cured paper. It is also preferable from the point of view of economy.

In the present invention, it has been found that an adhesive containing 5 to 70% by weight of aluminum powder is effective as an adhesive for imparting cigarette resistance to the decorative board as the adhesive for integrating the cured paper and the base material. Ta. That is, 5 to 70% by weight of aluminum powder with a particle size of 10 to 200 microns in the adhesive, preferably
Contain 30-50% by weight, 50-50% per 3 x 6 base material
The decorative board obtained by applying 200 g of cured paper and pressing it together with a press has excellent cigarette resistance, as shown in the examples below. The particle size of the aluminum powder is preferably within the above range; if it exceeds 200 microns, it will be difficult to uniformly disperse the aluminum powder in the adhesive, and the cigarette resistance of the decorative board will therefore be uneven. Also, particles as small as 10 microns are undesirable because they are too fine and difficult to handle, and there is a risk of fire. If the amount of aluminum powder in the adhesive is less than 5% by weight, the thermal conductivity will be insufficient and the cigarette resistance effect will also be poor. On the other hand, if it exceeds 70% by weight, the viscosity of the adhesive itself becomes too high, making application work difficult and reducing adhesive strength.

Any curable adhesive may be used as the adhesive, and solution-type or solvent-free urethane resins, epoxy resins, and acrylic resins are particularly preferably used in the present invention.

One embodiment of the present invention will be described below.

First, in the production of cured paper, the viscosity of the coating resin composition is appropriately adjusted with a solvent in order to produce a cured paper with a surface resin layer having a thickness of 10 to 40 micrometers. Usually, the amount of solvent is preferably selected within a range of 40% by weight or less depending on the basis weight of the thin paper. As a coating machine, a comma coater, a reverse roll coater, a gravure roll coater, etc. are used.

When thin paper coated with resin is produced by passing it through a heating furnace while applying tension to harden it (as disclosed in Japanese Patent Application Laid-Open No. 57-57098), it becomes a continuous hardened paper with no wrinkles. It is convenient because it can be obtained in

Next, apply 50 to 200 g of adhesive per 3 x 6 square with a roll coater etc. to the base material such as plywood, pre-dry if necessary, then layer hardened paper and use a roll laminator or press to dry at room temperature or The decorative laminate of the present invention can be obtained by pressing and laminating the sheets by heating, and releasing the press after an appropriate period of time.

The decorative board obtained in this way has a thick surface resin layer of 10 to 40 microns and uses a resin composition containing diallyl phthalate, so its surface properties meet the JAS FW standard and are organic. It is not attacked in any way even when immersed in solvents, etc., and has excellent cigarette resistance, so it can be used as an inexpensive material for walls, kotatsu boards, table surfaces, etc.

This will be explained below using examples.

Example 1 40% by weight of diallyl phthalate monomer, air-curable unsaturated polyester resin ("Epolack NW")
-2001 (manufactured by Nippon Shokubai Kagaku Kogyo Co., Ltd.) 50% by weight, 100 parts by weight of a resin solution consisting of 10% by weight toluene, 2 parts by weight of benzoyl peroxide, and 2 parts by weight of methyl ethyl ketone peroxide, 8% by weight as a curing catalyst and curing accelerator. A resin composition was prepared by adding 0.5 parts by weight of the cobalt octylate solution and small amounts of other slip agents and leveling agents.

The above resin composition was applied to thin paper having a basis weight of 30 g/m ² and printed with a teak grain pattern using a gravure roll coater so that the solid content upon curing would be 35 g/m ² . Next, this thin paper was cured in a heating furnace at 100 to 130°C while applying tension to the paper and wound into a roll to obtain a cured paper.

The surface resin layer of this cured paper was confirmed to have a thickness of 25μ as a result of measurement with a micrometer.

Next, polyurethane adhesive (“Takerakku A-
Aluminum paste (manufactured by Toyo Aluminum Co., Ltd., aluminum powder with a particle size of 100μ) is added to an adhesive consisting of 100 parts by weight of "369" manufactured by Takeda Pharmaceutical Co., Ltd. and 10 parts by weight of a curing agent ("A-19" manufactured by Takeda Pharmaceutical Co., Ltd.) and dioctyl phthalate. A paste was prepared by mixing 70 parts by weight (aluminum content: 65% by weight).

Using 2.7 mm thick plywood as a base material, apply the above adhesive with a roll coater to a total of 160 g/3 x 6 squares. After air drying, paste the above cured paper onto it and apply it to the surface of the cured paper. A plate was applied to the plate and pressurized at 130° C. and 5 kg/cm ² for 5 minutes, then rapidly cooled, left to stand for 5 minutes, and then decompressed to obtain a beautiful decorative board. About this decorative board JAS special plywood
I passed all of the FW standard tests. Also, spot tests using acetone and chloroform showed no abnormalities. Next, place a lit cigarette case (double-cut piece) directly on top of this decorative board.
Although it was left for a minute, no abnormality such as discoloration or burntness was observed.

Example 2 To 100 parts by weight of an air-curable unsaturated polyester resin ("Spirac U-3000X" manufactured by Showa Kobunshi Co., Ltd.) containing 20% by weight of diallyl phthalate monomer, 20 parts by weight of diallyl phthalate monomer was added,
A coating resin composition was prepared by adding 5 parts by weight of toluene, 1 part by weight of benzoyl peroxide, 1 part by weight of methyl ethyl ketone peroxide, 0.4 parts by weight of an 8% by weight cobalt octylate solution, and a small amount of a slip agent.

The above resin composition was applied to a thin paper having a basis weight of 23 g/m ² and printed with an oak grain pattern using a gravure coater so that the thickness of the surface resin layer after curing would be 20 μm. Next, this thin paper was cured in a heating furnace at 90 to 120°C while applying tension to the paper and wound up into a roll.

Next, 100 parts by weight of the same adhesive as in Example 1 was added to aluminum paste (Toyo Aluminum Co., Ltd. particle size
An adhesive prepared by mixing 90 parts by weight of 80 μ aluminum powder made into a paste with dioctyl phthalate (aluminum content 60% by weight) was applied to plywood plywood at 150 g/3 x 6 dimensions using a roll coater, and then heated at 100°C. After drying for a minute, the above-mentioned cured paper was laminated to this and pressed and laminated in the same manner as in Example 1 to obtain a decorative board. Example 1 about the obtained decorative board
Similarly, we conducted the FW standard test, acetone spot test, and cigarette resistance test, but no abnormalities were found in any of them.

Comparative Example 1 Using cured paper produced in the same manner as in Example 2,
A decorative board was obtained in the same manner as in Example 2 except that an adhesive containing no aluminum paste in the contact agent of Example 2 was used.

When this decorative board was subjected to the same tests as in Example 2, it passed the FW standard test and the acetone spot test, but in the cigarette resistance test, it turned yellow 1 minute after the start of the test, and After a few minutes, it turned black, and when it was left to stand further, cracks appeared in the surface resin layer.

Comparative Example 2 A cured paper was manufactured using the same resin composition and thin paper as in Example 1, and applying the resin composition in the same manner as in Example 1 so that the amount of the resin composition at the time of curing was 9+1 g/m ² . The thickness of the surface resin layer of this product was 5 μm.

Using this cured paper, it was laminated to a 2.7 mm plywood board using an adhesive containing aluminum powder to obtain a decorative board in the same manner as in Example 1.

When the above decorative board was subjected to the FW standard test, it failed the abrasion test and the scratch hardness test.

In addition to the FW standard test, as a practical water resistance test, we placed a piece of cloth containing a large amount of water on a decorative board and left it for 24 hours. did. By the way,
A similar test was performed on the decorative board of Example 1, and no abnormality was found.

Next, when a lit cigarette piece was placed directly on the decorative board of Comparative Example 2 and left for 2 minutes, the part was burnt and turned black.

Comparative Example 3 Using the same resin composition as in Example 1, a roll coater was used to coat 30 g/m ² thin paper with a solid content of 55
It was coated so that the amount was 2 g/m ² . This was cured in a heating oven while applying tension in the same manner as in Example 1, but as the curing progressed in the oven, the curling of the cured paper due to curing shrinkage became significant, and furthermore, the cured paper was partially cut. Also, the cured paper could not be normally wound into a roll. The thickness of the surface resin layer of this cured paper was 45 μm.

Claims (1)

[Claims] 1. Cured paper with a surface resin layer thickness of 10 to 40 microns, which is obtained by applying a thermosetting resin composition containing a diallyl phthalate monomer to thin paper and curing it, is integrated with a base material via an adhesive containing aluminum powder. A method for producing a decorative board with excellent cigarette resistance.