JP2854855B1 - Manufacturing method of natural wood decorative metal plate and natural wood decorative metal plate - Google Patents

Abstract

Abstract: PROBLEM TO BE SOLVED: To provide a coating solvent which does not contain formaldehyde which is presumed to be a cause of new-building disease and can be bent at an acute angle even if it is a type of plate which is easily cracked and causes peeling over time after coating. [Problem] To provide a natural wood decorative metal plate which is not easily affected by heat. [SOLUTION] When bonding a natural wood thin veneer and a metal plate, a porous buffer sheet is inserted between the two plates, and ethylene vinyl acetate copolymer having a crosslinkable component is provided. Polyethylene glycol is applied to the surface of a natural wood decorative metal plate obtained by bonding using an adhesive in which an emulsion adhesive and a cross-linking agent are blended, and hot-press bonded. In particular, a natural wood decorative thin veneer sheet in which a natural wood decorative thin veneer and a porous buffer sheet are pre-adhered is bonded to a metal plate to produce a natural wood decorative thin veneer sheet. A veneer sheet and a metal plate are adhered to produce a natural wood decorative metal plate, and polyethylene glycol is applied to the surface of the obtained natural wood decorative metal plate and hot-press bonded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a decorative metal sheet of natural wood and a decorative metal sheet for natural wood produced by the method.

[0002]

2. Description of the Related Art As an ordinary adhesive used for producing a natural wood decorative board, a polyvinyl acetate emulsion adhesive for woodworking or an aqueous adhesive obtained by blending SBR latex with a urea-formalin resin is used. In the case of conventional adhesives, they contain formaldehyde in essence, have a hard adhesive layer, and have poor adhesion to metal surfaces. Even if a metal plate is obtained, a large crack will occur in a thin natural wood veneer (hereinafter referred to as a “attached plate”) if it is bent. In order to solve this difficulty, Tokuho 4-56725
In the method of inserting a porous buffer sheet using an aqueous urethane resin dispersion and a cross-linking agent as an adhesive as in the proposal of No. 2, a certain effect is recognized, but the adhesive is limited and the merapi (tree species name) The selectivity of the attached plate has been a problem, such as the occurrence of cracks in the attached plate which is liable to crack.

[0003]

The problem to be solved by the present invention is that it does not contain formaldehyde which is presumed to be the cause of new diseases (referred to as chemical sensitivity in newly built houses) and is liable to cracks. It is an object of the present invention to obtain a natural wood decorative metal plate which can be bent at an acute angle even if it is a plate type and is not easily affected by a paint solvent which causes peeling over time after coating.

[0004]

In order to solve the problems, the adhesive must have the following properties. First, aluminum, alumite, steel plate, stainless steel, duralumin, titanium alloy, copper foil, zinc-coated steel plate,
Not only must it adhere well to various metal materials such as tinned steel sheets, but it must also exhibit good adhesion to resin-coated metal materials. That is, the metal plate may obstruct the adhesion due to the formation of an oxide on the surface, and the appearance of the metal plate or the resin-coated metal plate is made of an organic polymer material. Thus, it must be recognized that bonding of a metal plate requires such a wide range of adhesiveness, and the bonding problem must be solved. Second, since the film is formed by bending, the formed film of the adhesive must be flexible and conformable, and at the same time, must have high solvent resistance which is not affected by the organic solvent of various paints at the time of painting. For this reason, it is necessary to impart not only flexibility but also toughness with a crosslinked structure.
Third, it does not contain formaldehyde, which is one of the causative substances of new diseases. Therefore, it is necessary to avoid formalin resins such as urea resins and phenol resins. In this way, the adhesive that bonds the plate and the metal plate is a non-formalin type, which shows good adhesion to a wide range of metals and plastics, forms a flexible polymer film that can be followed, and forms the adhesive layer itself. The solvent resistance must also be good. In addition, ease of handling, risk of fire,
A water-based adhesive is desirable in consideration of worker health and the environment.

[0005] On the other hand, even if the attached plate is susceptible to cracks such as merapi, the occurrence of cracks during bending is eliminated.
High quality must be given. For that purpose, not only a device of the adhesive but also a technical means for essentially softening the attached plate itself is indispensable.

[0006] That is, the gist of the present invention is to solve the problems by both technical means of selecting a specific adhesive and softening the attachment plate.

[0007] That is, in order to solve the problem of the present invention, in the first aspect of the present invention, a porous buffer sheet is inserted between the attached plates and the metal plate at the time of bonding between the attached plates and the metal plate. Formaldehyde characterized by applying polyethylene glycol to the surface of a natural wood decorative metal plate obtained by bonding using an adhesive containing a vinyl acetate copolymer emulsion-based adhesive and a cross-linking agent, followed by hot-press bonding The present invention relates to a method for manufacturing a natural wood decorative metal plate having a crack preventing property at the time of bending without bending. The present invention, using this specific adhesive, Japanese paper, rayon paper, cloth, insert a porous buffer sheet such as non-woven fabric, and apply polyethylene glycol to the surface of a natural wood decorative metal plate as an intermediate layer, This is to apply heat and pressure to impregnate the inside of the attaching plate to make the attaching plate itself flexible.

[0008] In the invention of claim 2, the adhesive according to the above-mentioned means, that is, an adhesive obtained by mixing an ethylene-vinyl acetate copolymer emulsion-based adhesive having a crosslinking component and a crosslinking agent, is used. And a porous cushioning sheet are bonded in advance to produce a natural wood decorative thin veneer sheet, that is, a veneer cushioning material sheet. Then, the obtained natural wood decorative thin veneer sheet and a metal plate are further bonded to obtain a natural wood decorative veneer sheet. 2. The method according to claim 1, wherein a decorative metal plate is manufactured, and polyethylene glycol is applied to the surface of the obtained natural wood decorative metal plate and bonded by heat and pressure. That is, this means is a preferable means for carrying out the present invention.

In the invention of claim 3, the crosslinking component and the crosslinking agent of the adhesive in the means of claim 1 or 2 are polyvinyl alcohol, a self-emulsifying aqueous urethane resin dispersion, a polyisocyanate compound or a polyisocyanate compound thereof. Isocyanate-terminated prepolymers, oil-soluble epoxy resins, water-soluble epoxy resins, polyamines, amine pendant polymers, aziridine ring compounds, carbodiimide compounds, polymers having an oxazoline ring, and hydrazide compounds.
2. The method according to claim 1, wherein the combination comprises at least one kind.
And a method according to claim 2. The specific adhesive is a non-formalin-type aqueous adhesive in which a crosslinkable component and a crosslinking agent are blended with an ethylene-vinyl acetate copolymer emulsion in which polyvinyl alcohol is a protective colloid.

[0010] That is, the ethylene-vinyl acetate copolymer emulsion of the present invention is used as an ordinary adhesive base obtained by emulsion polymerization of modified polyvinyl alcohol such as polyvinyl alcohol and acetoacetylated polyvinyl alcohol as a protective colloid. A one-pack or two-pack water-based adhesive is obtained by blending a crosslinkable component such as a crosslinkable polymer and a reactive resin and a crosslinker such as a polyisocyanate and a reactive resin with the polymer emulsion.

Specifically, an ethylene-vinyl acetate copolymer emulsion containing polyvinyl alcohol (hereinafter, referred to as “polyvinyl alcohol”)
Abbreviated as "EVAEm". EVAEm-based water-soluble polymer-isocyanate type adhesive referred to in Japanese Adhesive Industry Standard (JAI standard) using a polyisocyanate compound or its isocyanate-terminated prepolymer as a hydroxyl group and a crosslinking agent, JP-B-63-33518 and JP-B-63-33518. Fairness 4-56
No. 725, an adhesive obtained by adding a water-soluble epoxy compound or an aziridine ring compound as a crosslinking agent to an adhesive containing a carboxyl group-containing urethane emulsion and EVAEm, a self-emulsifying urethane emulsion containing the urethane emulsion, and an EVAEm An adhesive obtained by adding a polyisocyanate compound or an isocyanate-terminated prepolymer thereof, a carbodiimide compound, or a polymer having an oxazoline ring as a crosslinking agent other than the above to an adhesive containing EVA as described in JP-B-7-47720.
Combination of epoxy-modified EVAEm-type adhesive and curing agent represented by an adhesive containing a bisphenol-type epoxy resin mixed with Em as a cross-linking agent and an amine-pendant-type polymer added as a crosslinking agent, acetoacetylated polyvinyl There is an EVAEm-based adhesive containing an alcohol in which a hydrazide compound such as adipic dihydrazide is blended as a crosslinking agent.

Among them, the adhesion between the attached plate and the porous buffer sheet is disclosed in Japanese Patent Publication No. 7-4 where the film properties are flexible and the solvent resistance is excellent.
No. 7720, JP-B-63-33518
No. or Japanese Patent Publication No. 4-56725, or an EVAEm-based water-soluble polymer-isocyanate type adhesive is preferable, and the adhesive between the obtained buffer plate and various metal plates is various metal plates or resins. An adhesive disclosed in JP-B-63-33518 or JP-B-4-56725, which exhibits good adhesiveness to a coated metal plate and has excellent film properties and excellent solvent resistance, or an EVAEm-based water-soluble polymer-isocyanate type Adhesives are preferred.

[0013] In a fourth aspect of the present invention, in any one of the first to third aspects, the polyethylene glycol has a molecular weight of 400 to 2,000. The present invention provides a method for producing a natural wood decorative metal plate having a crack-preventing property at the time of bending in the means. That is, polyethylene glycol has a molecular weight in the range of 200 to 4,000. However, the preferred molecular weight range is such that the raw material can be easily melted in a liquid state or in a water bath, and can be easily impregnated with hot pressure after application to soften the plate. This is the range of the means of claim 4. Molecular weight 4
If the molecular weight is less than 00, the residue after hot pressing may lower the adhesion depending on the type of coating, and the molecular weight is 2,000.
Above, it is difficult to melt and impregnate, so that the softening effect tends to slightly decrease.

A fifth aspect of the present invention relates to a natural wood decorative metal sheet which does not contain formaldehyde and which has a crack-preventing property at the time of bending, which is obtained by the method according to any one of the first to fourth aspects. That is, a natural wood decorative metal plate which has a porous buffer sheet inserted between an attached plate and a metal plate, and is adhered with an ethylene-vinyl acetate copolymer emulsion-based adhesive having a crosslinkable component and an adhesive containing a cross-linking agent. ,
5. The cracking during the bending process of the manufacturing method according to any one of claims 1 to 4, wherein the decorative plate of the natural wood decorative metal plate is a flexible plate softened by impregnation with polyethylene glycol. It is a natural wood decorative metal plate with protection.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The most preferred embodiments of the present invention are described in the followings. The followings are applied to a laminated plate, a porous buffer sheet such as thin Japanese paper used daily in the laminated plate industry, and a galvanized steel plate as a metal plate. The description will be made assuming that a natural wood decorative metal plate is manufactured. In addition, as a porous buffer sheet,
Rayon paper, cloth, and non-woven fabric are also preferable.

The terminating board is a sliced veneer having a thickness of about 0.08 to 1.0 mm obtained by slicing a tree species called a precious tree. First, a standard bonding operation between the attached plate and the porous buffer sheet will be described. Thin Japanese paper, which is often used in the attached board industry, is spread and loaded on a polyester decorative plywood board, temporarily fixed with an adhesive tape or the like, and then applied through a roll spreader. The adhesive is a water-based adhesive that is flexible and has good cross-linking properties. As shown in JP-B-7-47720, an adhesive obtained by adding an amine-pendant polymer solution as a cross-linking agent to an epoxy-modified EVA Em as a main agent is used. Is preferably about 50 to 150 g / m ² . After the application, the attached plates are arranged side by side and inserted into a hot press within 30 minutes for a deposition time, and 0.5 to 10 kg /
It is manufactured by thermocompression bonding at a pressure of cm ² for about 10 to 180 seconds. This production may be performed by cold pressing at room temperature,
Hot pressing gives a better finish and better adhesion,
It is preferable because productivity is good.

[0017] The thus-prepared cushioning sheet and the metal plate are then bonded together. In this description, a zinc-plated steel plate (about 0.1 to 3 mm in thickness), which is relatively difficult to bond, is used as the metal plate. The adhesive at this time is a water-based adhesive with excellent crosslinkability, which is flexible and has good adhesion to metals and plastics.
As shown in JP-B-63-33518 and JP-B-4-56725, urethane emulsion and EVAEm are used as main ingredients.
And an adhesive to which an aqueous dispersion of an aziridine ring compound is added as a crosslinking agent. The galvanized steel sheet is applied as it is or on a base plate such as plywood, and is applied through a roll spreader. The coating amount is 50 to 150 g / m ²
Is good. Further, it may be applied to the side of the cushioning material sheet side, or may be a double coat method of applying to both. The post-coating buffer sheet is placed on the metal plate within a deposition time of about 30 minutes after application, and inserted into a hot press. Normal bonding conditions are 0.5 to ¹⁰ kg / cm ² at 80 to 150 ° C.
The pressure is about 10 to 180 seconds.
In this production, cold pressing may be performed at room temperature, but hot pressing is preferable because the finish is good, the adhesion is reliable, and the productivity is good. In this way, a natural wood decorative metal plate which is a metal plate without surface treatment is obtained.

The surface of the metal plate has a molecular weight of 200
4,000, preferably polyethylene glycol having a molecular weight of 400-2000 (hereinafter abbreviated as PEG) as a stock solution or, in the case of a solid form, water-bath and melted, followed by spraying,
Apply by an appropriate method such as brushing. The coating amount is 5 to 150 g
/ M ² . If it is 5 g / m ² or less, the softening effect is poor, and if it is 150 g / m ² or more, the attached plate becomes a wet color, impairs aesthetic appearance, and deteriorates paint adhesion. The preferred application amount is 2
0 to 80 g / m ² . Further, within the above-mentioned range of the substantial application amount, application with a spray method or a brush may be performed after dilution with water, alcohol, or the like. Although hot pressing may be performed immediately after the application, it is preferable that the PEG is allowed to stand at room temperature for about 30 minutes or more to allow the PEG to penetrate the entire board and then hot pressed, so that the PEG is uniformly impregnated and the entire board is softened. It is preferred. The heat and pressure conditions are a press temperature of 50 to 120 ° C., a press time of 10 seconds to 10 minutes,
The pressure is selected in the range of 0.1 to 30 kg / cm ² . Below the respective lower limits, flexibility is poor, and above the respective upper limits, depending on the resin of the covering plate, discoloration such as burnt color may impair the appearance. To carry out the present invention effectively,
Pressing temperature is 60-100 ° C, pressing time is 30 seconds-5
The pressure is in the range of 1 to 10 kg / cm ² .

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to embodiments. (Reference example) First, using a sticking board (tree type name maple) having few cracks in a bending test, a sticking board (0.2 mm) was used.
Thickness) / Japanese paper / Zinc-coated steel sheet (0.3 mm thick) adhesion test was conducted using a commercially available ethylene-vinyl acetate copolymer emulsion-based adhesive without using a crosslinking agent, and a polyvinyl acetate-based adhesive for woodworking (one-pack type, two-part type). Liquid type), urethane emulsion type adhesive (two-part type), ethylene vinyl acetate copolymer emulsion type adhesive containing phenol resin or urea resin, and acrylic emulsion type adhesive (two-part type) An adhesion test similar to that described above was conducted, but none of them satisfied the adhesion and the adhesion strength. In addition, J
AS1 class immersion peeling test, occurrence of blistering at the time of painting or occurrence of poor bonding over time, notable cracks in bending test, and at least one problem of poor bonding. Even so, no adhesive was found that could have high adhesiveness, solvent resistance, and prevent cracking during bending.

(Embodiment 1) Maple (0.2 mm thick) and Merapi (0.2 mm thick), which are easy to crack, are used for the wood with low cracking. Was used to produce an attached buffer sheet comprising an attached sheet and a porous buffer sheet. That is, the thin Japanese paper was spread on a polyester decorative plywood on a base plate, loaded and temporarily fixed with an adhesive tape or the like, and then an adhesive was applied through a roll spreader. Adhesive is 7-47
No. 720 two-component aqueous adhesive was used. This is the main agent Bond CEL10 (trade name: manufactured by Konishi Co., Ltd.) 10
An adhesive obtained by mixing 3 parts by weight of a curing agent M (trade name: manufactured by Konishi Co., Ltd.) with 0 parts by weight. The coating amount was 70 g / m ² . After the application, the attached plates are arranged side by side and inserted into a hot press within 15 minutes for the deposition time,
It was manufactured by thermocompression bonding at a pressure of kg / cm ² for 60 seconds.

The sheet of cushioning material thus produced and the metal plate were then bonded. The metal plate used was a zinc-coated steel plate (0.3 mm thick). The adhesive used at this time was a two-part aqueous adhesive based on JP-B-63-33518 and JP-B-4-56725. This is the main agent name Bond CVC
An adhesive prepared by blending 5 parts by weight of a crosslinker CVC curing agent (trade name: Konishi Corporation) with 100 parts by weight of 33 (trade name: Konishi Corporation). The zinc-coated steel sheet was loaded on a base plate such as plywood, and applied by passing through a roll spreader. The coating amount was 80 g / m ² . With a deposition time of less than 15 minutes after the application, the attached buffer sheet was placed on a metal plate and inserted into a hot press. The bonding condition is 110
Thermocompression bonding was performed at a pressure of 5 kg / cm ² at 60 ° C. for 60 seconds. The natural wood decorative metal sheet treated with the following polyethylene glycol is referred to as the present invention 1, and the natural wood decorative metal sheet not treated is referred to as the comparative example 1.

The production conditions of the present invention 1 are as follows: polyethylene glycol having a molecular weight of 1500 (hereinafter referred to as P
After melting with hot water (abbreviated as EG), it was applied by air spray. The coating amount was 30 g / m ² . After the application, the mixture was left at room temperature for 1 hour to allow PEG to permeate the entire plate. The hot pressure conditions were a press temperature of 80 ° C., a press time of 60 seconds, and a pressure of 5 kg / cm ² .

The surfaces of the thus-prepared natural wood decorative metal sheets of the present invention 1 and comparative example 1 were both subjected to sanding treatment under the same conditions and finished with a woodworking urethane paint.

[0024]

[Table 1]

Further, a bending test was performed on each of the natural wood decorative metal plates. This bending test is 150mm
The square test piece was sandwiched between vice, and was bent at a stretch so that the bending angle became about 60 degrees (obtuse angle bending test) and about 100 degrees (a sharp angle bending test), and the occurrence of cracks in the bent portion was visually observed. In addition, the bending angle in this test is an angle representing how many times the flat metal plate itself (180 degrees) is bent so that the attached plate side of the natural wood decorative metal plate faces the front side. That is, when the metal plate is bent at 60 degrees, the bending angle of the metal plate itself is 120 degrees. And about 100
Bending at an acute angle (bent angle) increases the number of cracks and cracks in the bent portion. Table 1 shows the results.

In Table 1, the cross-cut adhesion test means that a diagonal line of a 150 mm square test piece is cut from the attached plate surface to the metal plate with a sharp knife, and a strong adhesive cloth tape is applied to the center cross-cut portion. Are adhered to each other, and then rapidly peeled off to see the adhesion state. The term “bulging during painting” refers to the occurrence of blistering in the attached plate conduit portion due to paint thinner after painting. The time-dependent peeling after painting is 10 with a weatherometer.
After irradiation for 0 hours, a cross-cut adhesion test is performed to check the change in the adhesion state. The JAS1 class immersion peeling test is performed on a painted test piece by applying the immersion peeling test of ordinary plywood in boiling water of Japanese Agricultural Standards mutatis mutandis. The judgment of the bending test was none, slightly, and the judgment became worse in the order of noticeable cracks and floating at the cracked portions. Here, "none" means that cracks are not visually observed in the bent portion.

(Example 2) An aluminum plate (0.
When a test was performed in the same manner as in Example 1 using a melamine-epoxy baked steel plate (thickness: 1.0 mm) as a resin-coated metal plate, the same results as those of the first invention were obtained.

[0028]

According to the method for producing a decorative metal sheet of a natural wood of the present invention, even a tree species such as merapi, which is liable to crack,
Even if it is bent at an acute angle, it is possible to obtain a natural wood decorative board which is high in quality and free of cracks in the bent portion and has high industrial value. Moreover, a good adhesion state can be obtained even with a poorly-adhesive metal plate or a resin-coated metal plate. Furthermore, since the adhesive and the plate softener are non-formalin type,
There is no emission of formaldehyde, which is the cause of new construction diseases.

The natural wood decorative metal plate of the present invention has functions as a metal such as precious wood's inherent warmth, toughness, and non-flammability. It is a high-performance material with functionality that can be bent freely at the same time as quality, and non-formalin type environmentally friendly characteristics. Therefore, it can be widely used for building materials, furniture, housing members, building materials such as heating floors, electronic material members such as electromagnetic wave shielding cabinets, and automobile interior members such as insole panels.

────────────────────────────────────────────────── ─── Continued on the front page (72) Hirofumi Matsubata Hiroshi Matsubata 3-14 Kamitenma-cho, Nishi-ku, Hiroshima Konishi Co., Ltd. Hiroshima Sales Office (58) Field surveyed (Int. Cl. ⁶ , DB name) B32B 15 / 10 B32B 5/18

Claims (5)

(57) [Claims] (1) A porous buffer sheet is inserted in bonding a thin natural wood veneer to a metal plate, and is obtained using an adhesive prepared by mixing an ethylene-vinyl acetate copolymer emulsion adhesive having a crosslinkable component and a crosslinking agent. A method for producing a natural wood decorative metal plate having a crack-preventing property at the time of bending, characterized in that polyethylene glycol is applied to the surface of a natural wood decorative metal plate and bonded by hot pressing. 2. A natural wood veneer thin veneer and a porous buffer sheet are adhered to each other by using an ethylene-vinyl acetate copolymer emulsion-based adhesive having a crosslinkable component according to claim 1 and an adhesive containing a crosslinking agent. After the natural wood veneer thin veneer sheet is once produced, the polyethylene wood is applied to the surface of the natural wood veneer metal plate obtained by bonding the natural wood veneer thin veneer sheet and the metal plate, and then hot-press bonded. Claim 1 characterized by the following:
A method for producing a natural wood decorative metal sheet having a crack-preventing property at the time of bending according to the above description. 3. The crosslinkable component and the crosslinker of the adhesive according to claim 1 or 2 are polyvinyl alcohol, an aqueous dispersion of a self-emulsifying urethane resin, a polyisocyanate compound or an isocyanate-terminated prepolymer thereof, and an oil-soluble polymer. 2. The method according to claim 1, wherein the resin is a combination of two or more of an epoxy resin, a water-soluble epoxy resin, a polyamine, an amine pendant polymer, an aziridine ring compound, a carbodiimide compound, a polymer having an oxazoline ring, and a hydrazide compound. 3. The method for producing a natural wood decorative metal plate having a crack-preventing property at the time of bending according to 2. 4. The method according to claim 1, wherein the polyethylene glycol has a molecular weight of 400 to 2,000. 4. The method according to claim 1, wherein the polyethylene glycol has a molecular weight of 400 to 2,000. Method for producing a natural wood decorative metal plate. 5. A natural wood bonded with an adhesive comprising a cross-linking agent and an ethylene-vinyl acetate copolymer emulsion adhesive having a cross-linkable component and a porous buffer sheet inserted between a thin veneer of a natural wood and a metal plate. 5. The decorative metal plate, wherein the natural wooden veneer is a natural wooden veneer softened by impregnation with polyethylene glycol. 4. A natural wood decorative metal plate having a crack-preventing property at the time of bending in the production by the production method described in 1).