JPH06200229A - Polyurethane adhesive and production of article covered with decorative sheet using the same - Google Patents

Abstract

PURPOSE:To obtain a polyurethane adhesive excellent in initial tack, bonding strength in an ordinary state and heat resistance by mixing a base, prepared by mixing a thermoplastic polyester-based urethane resin with a specified tackifier and dissolving the mixture in a solvent, with a polyisocyanate curing agent. CONSTITUTION:A base is prepared by mixing a thermoplastic polyester-based urethane resin with a tackifier comprising a phenol-modified xylene/ formaldehyde resin and/or a phenol-modified mesitylene/formaldehyde resin and dissolving this mixture in a solvent. This base is mixed with a polyisocyanate curing agent to obtain a polyurethane adhesive. This adhesive is applied to the back of a decorative sheet and dried, and the sheet is applied to a curved or irregular-surface core material and bonded to obtain an article covered with a decorative sheet.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyurethane adhesive and a method for producing a decorative sheet coating material using this adhesive.

[0002]

2. Description of the Related Art Polyurethane adhesives consisting of a base material prepared by dissolving a thermoplastic polyester-based urethane resin in a solvent and a polyisocyanate curing agent are excellent in normal-state adhesive strength and heat resistance and adhere to various materials such as plastics, metals and woods. Widely used in.

However, this type of polyurethane adhesive is
Initial adhesion is not sufficient. For example, when using this adhesive to coat a decorative sheet on a core material having a curved surface or an uneven surface and adhere the core sheet to produce a decorative sheet coating material, the decorative sheet repels to make a decorative sheet immediately after bonding. It is difficult to obtain a product of good quality because floating occurs between the core and the curved surface or the uneven surface of the core material.

It is known to incorporate tackifiers to improve the initial adhesion of polyurethane adhesives.
Examples of this tackifier include terpene resin, phenol resin, terpene phenol resin, rosin resin, and xylene resin (for example, September 25, 1987).
"Polyurethane resin handbook" published by Nikkan Kogyo Shimbun
Pp. 441-445).

[0005]

However, even when a polyurethane adhesive containing a tackifier as described above is used, when a decorative sheet is coated and adhered to a core material having a curved surface or an uneven surface, Immediately after bonding, floating still occurs between the decorative sheet and the curved or uneven surface of the core material,
Initial adhesion is not yet sufficient. Further, when such a tackifier is blended, there is a problem that the heat resistance of the polyurethane adhesive is lowered.

The present invention is intended to solve the above problems, and an object of the present invention is to provide a polyurethane adhesive having excellent initial adhesiveness, normal adhesive strength and heat resistance, and the use of this adhesive. Another object of the present invention is to provide a method for producing a decorative sheet coating material having a curved surface or an uneven surface.

[0007]

In order to achieve the above object, the present inventor has made detailed studies on various tackifiers to be blended with a polyurethane adhesive. As a result, they have found that the specific tackifier has an excellent effect. That is, the polyurethane adhesive of the present invention comprises a thermoplastic polyester-based urethane resin, a phenol-modified xylene formaldehyde resin or / and a phenol-modified mesitylene formaldehyde resin as a tackifier, which is dissolved in a solvent, and a polyisocyanate curing agent. Consists of.

Further, the method for producing a decorative sheet coating material of the present invention comprises applying the above-mentioned polyurethane adhesive to the back surface of the decorative sheet and drying it, and coating and adhering this on a core material having a curved surface or an uneven surface. is there.

The thermoplastic polyester-based urethane resin used in the present invention includes an active hydroxyl group of a saturated polyester resin having a terminal hydroxyl group obtained by a condensation reaction of a polybasic acid and a polyvalent hydroxyl compound, and an isocyanate group of a diisocyanate compound. It is an elastomer resin obtained by reacting in approximately equivalent amounts, which is a linear polymer having a urethane bond in the molecular chain. The average molecular weight is generally 10,000 to 500,000.

In this case, a saturated dicarboxylic acid such as adipic acid, azelaic acid, sebacic acid, terephthalic acid, isophthalic acid, phthalic acid or succinic acid is used as the polybasic acid. Further, as the polyvalent hydroxyl compound,
Ethylene glycol, propylene glycol, 1,4-
Saturated dihydric alcohols such as butanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, polyethylene glycol and polypropylene glycol are used.

As the diisocyanate compound to be reacted with the active hydroxyl group of the saturated polyester resin, tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, cyclohexyl methane diisocyanate and the like are used. In particular, a thermoplastic polyester-based urethane resin using adipic acid as the polybasic acid and 1,4-butanediol or 1,6-hexanediol as the polyvalent hydroxyl compound has a high crystallization rate and thus has a problem of initial adhesiveness. It is excellent and suitable.

In the present invention, a phenol-modified xylene formaldehyde resin or / and a phenol-modified mesitylene formaldehyde resin as a tackifier is blended in an appropriate amount with the above-mentioned thermoplastic polyester urethane resin, and this is dissolved in a suitable solvent to prepare a base resin. Is prepared.

The above-mentioned phenol-modified xylene-formaldehyde resin is a conventional xylene-formaldehyde resin obtained by addition-condensing m-xylene and formaldehyde with phenols. When excess phenols remain, formaldehyde is further added. It is an oligomer obtained by adding and post-condensing. In this case, the ratio of xylene formaldehyde resin and phenols is
Generally, the weight is 5: 5 to 7: 3. Further, the phenol-modified mesitylene formaldehyde resin is the above-mentioned m-
It is an oligomer obtained by using mesitylene in place of xylene. In both oligomers, the ratio of xylene or mesitylene formaldehyde resin to phenols is generally 5: 5 to 7: 3 by weight, and the average molecular weight thereof is
In general, those of 200 to 5000 are used.

The phenols to be reacted with xylene or mesitylene formaldehyde resin include phenol,
Cresol, bisphenolpropane, bisphenolmethane, resorcin, pyrocatechol, hydroquinone, pt-butylphenol, p-octylphenol, p-cyclohexylphenol, pt-aminophenol, p-phenylphenol, bisphenolsulfone, bisphenolether, etc. Alternatively, two or more kinds may be mixed and used. In particular, it is preferable to use p-t-butylphenol alone or a mixture of p-t-butylphenol and phenol. Such phenol-modified xylene-formaldehyde resin and phenol-modified mesitylene-formaldehyde resin are commercially available and can be easily obtained.

The phenol-modified xylene formaldehyde resin and / or the phenol-modified mesitylene formaldehyde resin is a thermoplastic polyester urethane resin 10
10 to 200 parts by weight, preferably 30 to 0 parts by weight
˜150 parts by weight are blended. If this amount is less than 10 parts by weight, the normal adhesive strength will decrease, and if it exceeds 200 parts by weight, the initial adhesiveness will decrease.

As a solvent for dissolving these resin blends, ethyl acetate, methyl ethyl ketone, acetone, toluene, xylene, dichloromethane, 1,1,1-trichloroethane, etc. may be used alone or in admixture of two or more. To be These solvents are generally used in the range of 50 to 5000 parts by weight with respect to 100 parts by weight of the resin composition.

Examples of the polyisocyanate curing agent used in the present invention include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate and triphenylmethane triisocyanate; hexamethylene diisocyanate and 2,2,4-trimethyl. Aliphatic polyisocyanates such as hexamethylene diisocyanate; alicyclic polyisocyanates such as isophorone diisocyanate, hydrogenated tolylene diisocyanate and hydrogenated diphenylmethane diisocyanate are used. These polyisocyanate curing agents may be used alone or in admixture of two or more.

The polyurethane adhesive of the present invention is usually
It is a two-component mixed type adhesive consisting of the above-mentioned main agent and a curing agent, and the main agent and the curing agent are mixed immediately before use. The curing agent is generally used by mixing it in the range of 1 to 200 parts by weight with respect to 100 parts by weight of the thermoplastic polyester urethane resin in the base material. If necessary, an inorganic filler, a colorant, a stabilizer, a reaction accelerator, etc. may be added.

The polyurethane adhesive of the present invention thus obtained is excellent in initial adhesiveness, normal adhesive strength, heat resistance and water resistance and is widely used for adhering various materials such as plastic, metal and wood. In particular, it is suitably used for producing a decorative sheet coating material having a curved surface or an uneven surface that requires strong initial adhesiveness.

The method for producing a decorative sheet coating material having a curved surface or an uneven surface will be described below. A decorative sheet and a core material having a curved surface or an uneven surface are prepared. Decorative sheets include vinyl chloride resin, vinylidene chloride resin,
Printing plain or letters or patterns made of synthetic resin such as polyethylene resin, polypropylene resin, polystyrene resin, ABS resin, polyamide resin, polyester resin, polyurethane resin, polyvinyl alcohol resin, ethylene-vinyl acetate copolymer resin, chlorinated polypropylene resin The sheet used is a laminated sheet, a laminated sheet made of wood, a laminated sheet impregnated with a synthetic resin, a metal foil such as an aluminum foil, paper or cloth.

Examples of the core material having a curved surface or an uneven surface are vinyl chloride resin, vinylidene chloride resin, polyethylene resin, polypropylene resin, polystyrene resin, ABS resin, polyamide resin, polyester resin, polyurethane resin, polyvinyl alcohol resin, ethylene-acetic acid. Cross-section made of vinyl copolymer resin, synthetic resin such as chlorinated polypropylene resin, natural wood, plywood, particle board, hard fiber board, semi-hard fiber board, wood such as laminated wood, metal such as aluminum, iron, stainless steel, etc. A modified shaped body is used.

First, a decorative sheet is supplied, the polyurethane adhesive of the present invention is applied to the back surface of the decorative sheet, and then dried with hot air or the like. The application of the adhesive is performed by a knife coater, a roll coater, a curtain flow coater, a spray, or the like, and the coating film thickness is usually 1 to 500.
It is coated so as to have a thickness of μm, preferably 5 to 300 μm. Drying is generally room temperature to 100 ° C., preferably 40 to
It is carried out at about 60 ° C. for 1 second to 30 minutes, preferably about 5 seconds to 1 minute.

Next, this decorative sheet is coated along the surface of the core material having a curved surface or an uneven surface, and is pressed by a roll or the like, or is adsorbed by a rubber plate or the like of a vacuum forming machine. The pressure is generally 0.1 to 10 kg / cm (linear pressure) and is applied instantaneously. The combination of the decorative sheet and the core material is not limited at all, but particularly preferable combinations are a synthetic resin sheet and wood, a synthetic resin sheet and metal, a synthetic resin sheet and synthetic resin, a laminated sheet and wood. In this way, a decorative sheet coating material having a curved surface or an uneven surface is manufactured.

[0024]

[Function] A polyurethane adhesive consisting of a main agent prepared by dissolving a thermoplastic polyester urethane resin in a solvent and a polyisocyanate curing agent contains a phenol-modified xylene formaldehyde resin and / or a phenol-modified mesitylene formaldehyde resin as a tackifier. When,
An adhesive having excellent initial adhesiveness, adhesive strength, and heat resistance can be obtained. The reason is not clear. Such tackifiers are not used in conventional polyurethane adhesives and are unique in this respect.

When the above-mentioned polyurethane adhesive is applied to the back surface of a decorative sheet and dried, and the core material having a curved surface or an uneven surface is coated and adhered, this adhesive has excellent initial adhesiveness. The floating due to the repulsion of the decorative sheet does not occur between the decorative sheet immediately after bonding and the curved surface or uneven surface of the core material.

[0026]

EXAMPLES Examples and comparative examples of the present invention will be shown below. Example 1 100 parts by weight of adipic acid / butanediol / tolylene diisocyanate (Desmocol 400: manufactured by Bayer) as a thermoplastic polyester urethane resin, and t-butylphenol-modified xylene formaldehyde resin (Nicanol HP100: as a tackifier). 100 parts by weight (manufactured by Mitsubishi Gas Chemical Co., Inc.) was dissolved in 450 parts by weight of dichloromethane to prepare the main agent. A polyurethane adhesive was manufactured by mixing 100 parts by weight of this main agent with 5 parts by weight of crude diphenylmethane diisocyanate (Sumijour 44V20: manufactured by Sumitomo Bayer) as a curing agent.

Profile Laminator (PL-30
(0: manufactured by Marunaka Shoji Co., Ltd.), a vinyl chloride resin sheet having a thickness of 170 μm is supplied at a rate of 15 m / min, and one side thereof is coated with the adhesive having a thickness of 100 μm by a knife coater, The material is dried by passing through a hot air drying oven, and while covering the core material consisting of a semi-rigid fiber board with a cross-section of irregular shape from the front surface to both edges of the back surface, it is pressure-bonded with a pressure-bonding roller to cover the decorative sheet material ( Building materials). The core material has a length of 2 m and a width of 10
0mm, thickness 20mm, depth and width of about 5mm,
Two U-shaped grooves having a corner R of 2 mm are provided at intervals of 70 mm in the length direction.

The profile laminator includes a supply roll for continuously feeding the decorative sheet, a knife coater for applying the adhesive to the decorative sheet, a hot air dryer for drying the applied adhesive, and a fixed length. Core material feeder for supplying the core material, a pressure roll for pressing the decorative sheet along the curved surface or uneven surface of the core material while covering the decorative sheet with the core material, and the decorative sheet to the length of the core material It is equipped with a cutter for cutting. With respect to this decorative sheet-covered building material, the initial adhesion, normal-state peel adhesion strength, and heat creep resistance were measured by the following methods. The results are shown in Table 1.

(1) Initial Adhesion With regard to the decorative sheet-covered building material immediately after production, it was visually judged whether or not there was an abnormality such as floating on the decorative sheet on the surface irregularities.

(2) Normal peel strength The flat surface of the decorative sheet-covered building material is 100 mm long x 25 mm wide
Cut to the size of, peel off one end of the decorative sheet in advance,
After holding this at 20 ° C for 2 days, fix one end of the core material and the decorative sheet to the chuck, and set the temperature to 20 ° C and the humidity to 60% R.
The 180-degree peel strength was measured in an atmosphere of H using an autograph at a tensile speed of 200 mm / min.

(3) Heat-resistant creep resistance The flat portion of the decorative sheet-covered building material is 100 mm in length and 25 mm in width.
Cut to the size of, peel off one end of the decorative sheet in advance,
After holding this at 20 ° C for 2 days, hold it vertically and fix the upper end of the core material, attach a weight of 500g to one end of the decorative sheet, and remove the 180 ° peel length after 24 hours in the atmosphere of 60 ° C. Was measured.

Example 2 In Example 1, the tackifier was changed to phenol / t-butylphenol modified xylene formaldehyde resin (Nikanol HP210: manufactured by Mitsubishi Gas Chemical Co., Inc.). Other than that is the same as that of the first embodiment. The results are shown in Table 1.

Example 3 In Example 1, the tackifier was t-butylphenol modified xylene formaldehyde resin (Nicanol HP7.
0: manufactured by Mitsubishi Gas Chemical Co., Inc.). Other than that is the same as that of the first embodiment. The results are shown in Table 1.

Example 4 In Example 1, the tackifier was t-butylphenol modified xylene formaldehyde resin (Nicanol HP1).
20: manufactured by Mitsubishi Gas Chemical Co., Inc.). Other than that is the same as that of the first embodiment. The results are shown in Table 1.

Example 5 In Example 1, the thermoplastic polyester urethane resin was changed to adipic acid / hexanediol / tolylene diisocyanate (Desmocoll 500: manufactured by Bayer). Other than that, it is the same as that of the first embodiment. The results are shown in Table 1.

Example 6 In Example 1, the compounding amount of the tackifier was changed to 30 parts by weight. Other than that is the same as that of the first embodiment. The results are shown in Table 2.

Example 7 In Example 1, the compounding amount of the tackifier was changed to 50 parts by weight. Other than that is the same as that of the first embodiment. The results are shown in Table 2.

Example 8 In Example 1, the compounding amount of the tackifier was changed to 150 parts by weight. Other than that is the same as that of the first embodiment. The results are shown in Table 2.

Example 9 In Example 1, the tackifier was t-butylphenol modified mesitylene formaldehyde resin (Nicanol HP).
150: manufactured by Mitsubishi Gas Chemical Co., Inc.). Other than that is the same as that of the first embodiment. The results are shown in Table 2.

Example 10 In Example 1, the thermoplastic polyester urethane resin was changed to adipic acid / hexanediol / tolylene diisocyanate (Desmocoll 500: manufactured by Bayer). Further, the tackifier is t-butylphenol-modified mesitylene formaldehyde resin (Nicanol HP1
50: manufactured by Mitsubishi Gas Chemical Co., Inc.). Other than that is the same as that of the first embodiment. The results are shown in Table 2.

Comparative Example 1 In Example 1, the tackifier was changed to xylene formaldehyde resin (Nikanol H: manufactured by Mitsubishi Gas Chemical Co., Inc.). Other than that is the same as that of the first embodiment. The results are shown in Table 3.
Shown in.

Comparative Example 2 In Example 1, the tackifier was changed to t-butylphenol resin (Hitanol 643KN: manufactured by Hitachi Chemical Co., Ltd.). Other than that is the same as that of the first embodiment. The results are shown in Table 3.
Shown in.

Comparative Example 3 In Example 1, the tackifier was changed to a terpene phenol resin (Tamanol 803 manufactured by Arakawa Chemical Co., Ltd.). Other than that is the same as that of the first embodiment. The results are shown in Table 3.

Comparative Example 4 In Example 1, the tackifier was changed to a rosin ester resin (ester gum H: Arakawa Chemical Co., Ltd.). Other than that is the same as that of the first embodiment. The results are shown in Table 3.

Comparative Example 5 In Example 1, the tackifier was changed to coumarone indene resin (Coumaron V120: manufactured by Nippon Steel Chemical Co., Ltd.). Other than that is the same as that of the first embodiment. The results are shown in Table 3.

[0046]

[Table 1]

[0047]

[Table 2]

[0048]

[Table 3]

[0049]

As described above, in the polyurethane adhesive of the present invention, a phenol-modified xylene-formaldehyde resin or / and a phenol-modified mesitylene-formaldehyde resin are blended as a tackifier with a thermoplastic polyester-based urethane resin, which is used as a solvent. Comprised of a dissolved main agent and a polyisocyanate curing agent, in particular, by blending a phenol-modified xylene formaldehyde resin or / and a phenol-modified mesitylene formaldehyde resin as a tackifier, initial adhesiveness, compared to conventional polyurethane adhesives, Excellent normal strength and heat resistance. Also, the water resistance is excellent. Therefore, this adhesive is widely used for bonding various materials such as plastic, metal, and wood.

In the method for producing a decorative sheet coating material of the present invention, the above-mentioned polyurethane adhesive is applied to the back surface of the decorative sheet and dried, and this is coated and adhered to a core material having a curved surface or an uneven surface. And, due to the excellent initial adhesiveness of the adhesive, the decorative sheet is prevented from floating from the curved surface or uneven surface of the core material, has excellent workability, and has a normal adhesive strength, heat resistance, and water resistance. Alternatively, a decorative sheet coating material having an uneven surface can be obtained. The decorative sheet coating material thus obtained is suitably used for building materials, automobile interior materials and the like.

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[Procedure amendment]

[Submission date] November 2, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

The above phenol-modified xylene-formaldehyde resin is obtained by reacting a normal xylene-formaldehyde resin obtained by addition-condensing xylene and formaldehyde with phenols and adding excess formaldehyde when excess phenols remain. It is an oligomer obtained by post-condensation. In this case, the ratio of xylene formaldehyde resin to phenols is generally 5: 5 to 7: 3 by weight. The phenol-modified xylene-formaldehyde resin is an oligomer obtained by using mesitylene instead of the above xylene .
In both oligomers, the ratio of xylene or mesitylene formaldehyde resin to phenols is generally 5: 5 to 7: 3 by weight, and the average molecular weight thereof is generally 2
The thing of 00-5000 is used.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0023

[Correction method] Change

[Correction content]

Next, this decorative sheet is coated along the surface of the core material having a curved surface or an uneven surface, and is pressed by a roll or the like, or is adsorbed by a rubber plate or the like of a vacuum forming machine. The pressure is generally 0.1 to 10 kg / cm (linear pressure) and is applied instantaneously. The combination of the decorative sheet and the core material is not limited at all, but particularly preferable combinations are a synthetic resin sheet and wood, a synthetic resin sheet and metal, a synthetic resin sheet and synthetic resin, a laminated sheet and wood. In this way, a decorative sheet coating material having a curved surface or an uneven surface is manufactured.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0048

[Correction method] Change

[Correction content]

[0048]

[Table 3]

Claims (2)

[Claims] 1. A polyurethane adhesive consisting of a thermoplastic polyester-based urethane resin and a phenol-modified xylene formaldehyde resin or / and a phenol-modified mesitylene formaldehyde resin as a tackifier, which is dissolved in a solvent, and a polyisocyanate curing agent. Agent. 2. A method for producing a decorative sheet coating material, characterized in that the polyurethane adhesive according to claim 1 is applied to the back surface of a decorative sheet, dried, and coated on and adhered to a core material having a curved surface or an uneven surface. Method.