JP4536405B2 - Resin sheet laminated metal plate - Google Patents

Description

The present invention is a resin sheet laminate in which the metal plate and the resin sheet are firmly bonded, the adhesion at the bonding interface is good, and the water resistance (adhesion after hot water test) and workability (adhesion after processing) are excellent. It relates to a metal plate .

  Conventionally, resin sheet (thin film or film; hereinafter abbreviated as resin sheet) laminated metal plates such as resin-laminated steel plates and resin-laminated aluminum plates have various designs utilizing the design properties and composite material functionality of the resin sheets. Used in the field. In this resin sheet laminated metal plate, generally, a lamination method using an adhesive or a lamination method by heat fusion is employed for laminating the resin sheet and the metal plate. Among them, the laminating method using an adhesive is widely used from the viewpoints of convenience and low cost.

When laminating a resin sheet and a metal plate with an adhesive, the metal plate is generally coated with a coater or the like in a state where the adhesive is diluted with a solvent. However, in recent years, there has been a movement to regulate the use of solvents due to contamination of the work environment and health problems of workers, and various types of emulsified adhesives that do not use solvents have been proposed (for example, Patent Document 1). And Patent Document 2). Resin sheet laminated metal plates are often used in applications where design is important by taking advantage of their design properties, especially resin sheet laminated metal plates used for manufacturing parts around water, such as unit baths. However, water resistance is required, but conventionally proposed emulsion adhesives have a problem of insufficient water resistance and workability.
JP 2002-309216 A JP 2003-246974 A

The inventors of the present invention have arrived at the present invention as a result of intensive studies to solve the above-mentioned problems and provide a resin sheet laminated metal plate having excellent water resistance and workability . The object of the present invention is a resin in which the metal plate and the resin sheet are firmly bonded, the adhesion at the bonding interface is good, and the water resistance (adhesion after hot water test) and workability (adhesion after processing) are excellent. The object is to provide a sheet metal sheet .

In order to solve the above problems, a urethane component resin emulsion (A) having a carboxyl group and a resin component comprising a crosslinking agent (B) having an isocyanate group, the silane coupling agent (C) is a urethane having a carboxyl group. The main component is a metal plate and polyvinyl chloride through a laminating adhesive composed mainly of a resin composition composed of 0.1 to 5 parts by weight per 100 parts by weight of the solid content of the resin-based resin emulsion (A). A resin sheet-laminated metal plate is provided, wherein the resin sheet is laminated.

The present invention has the following particularly advantageous effects, and its industrial utility value is extremely great.
1. The resin composition used for the production of the resin sheet laminated metal plate according to the present invention exhibits an emulsion state and is used as a main component of a paint, an adhesive, etc., and a film (thin film) formed from this emulsion is a substrate. Excellent adhesion to metal plates , water resistance and chemical resistance.
2. Since the resin composition used for the production of the resin sheet laminated metal plate according to the present invention is a solvent-free type or contains a small amount of a solvent, when used for a paint or an adhesive, There are no health problems for workers.
3. Since the adhesive for laminating the metal plate and the resin sheet according to the present invention is in an emulsion state, it is excellent in applicability.
4). In the resin sheet laminated metal plate according to the present invention , the metal plate and the resin sheet are firmly bonded , and are excellent in water resistance (adhesion after hot water test) and workability (adhesion after processing). It is suitable for various uses of sheet-laminated metal plates, particularly for resin-laminated metal plates having design properties, or for manufacturing parts around water.

Hereinafter, the present invention will be described in detail.
In the present invention, the urethane resin emulsion (A) having a carboxyl group (hereinafter sometimes abbreviated as component (A)) is, for example, a polymer polyol (a) having two or more hydroxyl groups and one or more carboxyl groups. A urethane-based resin synthesized from the compound (b) having an organic polyisocyanate (c) and, if necessary, the chain extender (d) and / or the polymerization terminator (e), It means an anionic self-emulsifying urethane resin emulsion emulsified in water by f). In the present invention, the self-emulsifying emulsion means an emulsion having a hydrophilic carboxyl group in the molecule and exhibiting water solubility or water dispersibility by itself.

  Examples of the polymer polyol (a) include polyether polyol (a1), polyester polyol (a2), polylactone polyol (a3), polycarbonate polyol (a4), and polyolefin polyol (a5). Specific examples of the polyether polyol (a1) include those obtained by polymerizing or copolymerizing alkylene oxides such as ethylene oxide, propylene oxide, 1,2-butylene oxide, and tetrahydrofuran. Specific examples include polyethylene glycol, polypropylene glycol, polyoxyethylene-polyoxypropylene (block copolymer or random copolymer) glycol, polyoxyethylene-polytetramethylene ether glycol (block copolymer or random copolymer), polytetra And methylene ether glycol.

  Specific examples of the polyester polyol (a2) include aliphatic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, glutaric acid, and azelaic acid, and / or aromatic dicarboxylic acids such as isophthalic acid and terephthalic acid, and ethylene. A dihydric alcohol such as glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, 3-methyl-1,5-pentadiol, neopentyl glycol, 1,4-dihydroxymethylcyclohexane, A condensed product may be mentioned. Specific examples thereof include polyethylene adipate diol, polybutylene adipate diol, pohexamethylene adipate diol, polyneopentyl adipate diol, polyethylene / butylene adipate diol, poly-3-methylpentane adipate diol, polybutylene isophthalate diol, and the like. .

  Specific examples of the polylactone polyol (a3) include polycaprolactone diol, polycaprolactone triol, and poly-3-methylvalerolactone diol. Specific examples of the polycarbonate polyol (a4) include polyhexamethylene carbonate diol. Specific examples of the polyolefin polyol (a5) include polybutadiene glycol, polyisobutylene glycol, and hydrides thereof. These exemplified polymer polyols (a) may be used alone or in combination of two or more. Among these polymer polyols (a), polyether polyol (a1), polyester polyol (a2), polylactone polyol (a3) and polycarbonate polyol (a4) are preferred. The number average amount of the polymer polyol (a) is preferably 300 to 5,000, more preferably 500 to 3,000.

  Examples of the compound (b) having two or more hydroxyl groups and one or more carboxyl groups (hereinafter sometimes simply referred to as the compound (b)) include dimethylol such as dimethylolacetic acid, dimethylolpropionic acid, and dimethylolbutyric acid. An alkanoic acid is mentioned. Of these, dimethylolpropionic acid is preferred. The amount of the compound (b) is 5% by weight or less, more preferably 0.1 to 4% by weight with respect to the polymer polyol (a). If the amount of the compound (b) is less than 0.1% by weight, it is difficult to obtain a stable urethane-based resin emulsion (A) of the resin component, and if it exceeds 5% by weight, the hydrophilicity in the resin component becomes high. Since the viscosity of the resin emulsion is remarkably increased, and the water resistance of the film (thin film or sheet) obtained from the urethane resin emulsion (A) is lowered, both are not preferable.

  The organic polyisocyanate (c) is an organic compound having an NCO group in the molecule, the aliphatic diisocyanate (c1) having 2 to 12 carbon atoms (excluding carbon in the NCO group, the same shall apply hereinafter), and 4 carbon atoms. Derived from -15 cycloaliphatic diisocyanate (c2), araliphatic diisocyanate (c3) having 8 to 12 carbon atoms, and aromatic diisocyanate, aliphatic diisocyanate or alicyclic diisocyanate having 6 to 20 carbon atoms. Isocyanurate and pyret-modified polyisocyanate.

  Specific examples of the aliphatic diisocyanate (c1) include hexamethylene diisocyanate and lysine diisocyanate. Specific examples of the alicyclic diisocyanate (c2) include cyclohexylmethane diisocyanate, isophorone diisocyanate, cyclohexane diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylylene diisocyanate, and the like. Specific examples of the aromatic diisocyanate (c3) include tolylene diisocyanate, α, α, α ′, α′-tetramethylxylylene diisocyanate, diphenylmethane diisocyanate, naphthylene diisocyanate, xylylene diisocyanate, and the like. These exemplified organic polyisocyanates (c) may be used alone or in combination of two or more.

  Among these organic polyisocyanates (c), preferred are aliphatic diisocyanate (c1) and alicyclic diisocyanate (c2), and particularly preferred are hexamethylene diisocyanate, cyclohexylmethane diisocyanate and isophorone diisocyanate. Preference is likewise given to isocyanurates and pyret-modified polyisocyanates derived from aliphatic diisocyanates (c1) or alicyclic diisocyanates (c2). The amount of the organic polyisocyanate (c) is preferably 60% by weight or less, more preferably 1 to 50% by weight, based on the polymer polyol (a).

  Specific examples of the chain extender (d) to be included in the resin component as necessary include a low molecular polyol (d1) and a polyamine (d2). As the low molecular polyol (d1), for example, the dihydric alcohol mentioned as the raw material of the polyester polyol (a2), and its alkylene oxide low molar adduct (number average molecular weight less than 500), bisphenol alkylene oxide low molar adduct (Number average molecular weight less than 500), trihydric alcohols such as glycerin, trimethylolethane, trimethylolpropane, and alkylene oxide low molar adducts thereof (number average molecular weight less than 500).

  Specific examples of the polyamine (d2) include aliphatic polyamines such as ethylenediamine, N-hydroxyethylethylenediamine, tetramethylenediamine, hexamethylenediamine, and diethylenetriamine, 4,4′-diaminodicyclohexylmethane, 1,4-diaminocyclohexane, Alicyclic polyamines such as isophoronediamine, aliphatic polyamines having an aromatic ring such as xylylenediamine, α, α, α ′, α′-tetramethylxylylenediamine, 4,4′-diaminodiphenylmethane, tolylene Aromatic polyamines such as amine, benzidine, and phenylenediamine are listed. These may be used alone or in combination of two or more. The amount of the chain extender (d) is preferably 30% by weight or less, more preferably 0.5 to 20% by weight, based on the polymer polyol (a) used.

  Further, as necessary, the polymerization terminator (e) contained in the resin component includes low-molecular monoalcohols such as methanol, butanol and cyclohexanol, and alkanolamines such as mono- and di-ethylamine, mono- and di-butylamine. Kind. The compounding quantity of a polymerization terminator (e) is 20 weight% or less with respect to the high molecular polyol (a) to be used, More preferably, it is 0.1 to 10 weight%.

  Specific examples of the salt forming agent (f) include trialkylamines such as trimethylamine, triethylamine, triisopropylamine, tri-n-propylamine, tri-n-butylamine, N-methylmorpholine, N-ethylmorpholine, and the like. N-dialkylalkanolamines such as N-alkylmorpholines, N-dimethylethanolamine, N-diethylethanolamine and the like can be mentioned. These can be used alone or in combination of two or more. Of these, preferred are trialkylamines, and particularly preferred is triethylamine. The amount of the salt forming agent (f) is preferably 0.3 to 1 equivalent, more preferably 0.4 to 0.8 equivalent, relative to 1 equivalent of the carboxyl group of the compound (b) used.

  In producing a urethane resin emulsion, first, in the presence or absence of an organic solvent, a polymer polyol (a), a compound (b) having two or more hydroxyl groups and one or more carboxyl groups, an organic polymer, The carboxyl group-containing urethane resin is formed by reacting the isocyanate (c), if necessary, the chain extender (d) and / or the polymerization terminator (e) by a one-stage method or a multistage method. Next, the obtained carboxyl group-containing urethane resin is neutralized with the salt forming agent (f) or mixed with water while neutralizing to obtain a dispersion (emulsion). Thereafter, the solvent is removed as necessary, and a self-emulsifying urethane resin emulsion (A) in which urethane resin particles having an average particle diameter of about 0.001 to 1 μm are dispersed is obtained. The formation reaction of the urethane-based resin is usually performed at a temperature of 20 to 150 ° C., preferably 50 to 120 ° C., but when an amine is used, it is performed at a temperature of 80 ° C. or less, preferably 60 to 0 ° C.

  In order to accelerate the reaction, an amine catalyst used in a usual urethane resin forming reaction, or dioctyltin dimaleate, dibutyltin dilaurate, stannous octylate, dibutyltin oxide, bis (tri-n-butyl) Tin-based catalysts such as tin oxide) can be used. In the case of using an organic solvent, a solvent that is water-soluble and has a boiling point comparable to or lower than that of water is preferable. Specific examples include acetone, methyl ethyl ketone, tetrahydrofuran, and dioxane.

  The production method of the urethane resin emulsion (A) is not particularly limited. The urethane resin emulsion (A) may be a commercially available product as long as it has the above-mentioned characteristics. Examples of commercially available urethane resin emulsions (A) include Sanyo Kasei Kogyo Co., Ltd., Permarin (all trade names), Dai-ichi Kogyo Seiyaku Superflex (trade names), Dainippon Ink Co., Ltd. Bondic (trade name) and the like are listed.

  In the present invention, the crosslinking agent (B) having an isocyanate group (hereinafter sometimes simply referred to as component (B)) means one having at least one isocyanate group in the molecule and capable of being dispersed in water. . There is no particular limitation as long as it has such characteristics, but considering the progress of the crosslinking reaction with the urethane-based resin emulsion (A), compatibility, workability, etc., it is easy to mix with water. Preferably, self-emulsifying polyisocyanate (B1) or aqueous block polyisocyanate (B2) having one or more of polyethylene oxide, carboxyl group, sulfonic acid group and the like and modified with a hydrophilic component is preferable.

  The self-emulsifying polyisocyanate (B1) can be produced, for example, by introducing a hydrophilic group having at least one active hydrogen group capable of reacting with an isocyanate group and a hydrophobic group into the polyisocyanate molecular chain. it can. The introduction of the hydrophobic group simultaneously with the hydrophilic group is because when the polyisocyanate is dispersed in water, the reaction between the water molecules present around the polyisocyanate and the unreacted isocyanate group present in the vicinity is performed. This is because the effect of suppressing surface chemistry is obtained based on steric hindrance or its lipophilicity. Examples of the hydrophobic group include higher alcohols having one or more active hydrogen groups, and hydroxyl group-containing fatty acid esters.

  Examples of the polyisocyanate used to obtain the self-emulsifying polyisocyanate (B1) include phenylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, naphthylene diisocyanate, diphenylmethane diisocyanate, and the isomers thereof. Aromatic diisocyanates consisting of, aliphatic diisocyanates such as 1,6-hexamethylene diisocyanate, 1,12-dodecane diisocyanate, cycloaliphatic diisocyanates such as cyclohexane diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, norbornane diisocyanate, 2, 4,6-triisocyanatotoluene, 2,4,4'-triisocyanate DOO diphenylether, birds and the like triisocyanates such as (isocyanate phenyl) methane.

  In addition, isocyanate group-terminated compounds by reaction of polyisocyanates with active hydrogen group-containing compounds, or reactions of these compounds, such as adduct type polyisocyanates, uretdioneation reactions, isocyanurate reactions, carbodiimidization reactions, ureton iminization reactions, burettes. Examples thereof include isocyanate-modified products obtained by chemical reaction and mixtures thereof. Of these polyisocyanates, aliphatic polyisocyanates and alicyclic polyisocyanates are preferred from the viewpoints of water dispersion stability, stability of isocyanate groups after water dispersion, non-yellowing, and the like. From the viewpoint, an isocyanurate ring-containing polyisocyanate having an average number of isocyanate groups of 2 or more is more preferable.

  This isocyanurate ring-containing polyisocyanate includes, for example, raw diisocyanates such as tertiary amines, alkyl-substituted ethyleneimines, tertiary alkylphosphines, acetylacene metal salts, and metal salts of various organic acids. Liquid polyol or dioctyl phthalate (DOP) in the temperature range of 0 to 90 ° C. in the presence or absence of a solvent using a catalyst and / or an isocyanurate catalyst and, if necessary, a cocatalyst. It can be obtained by reacting in a plasticizer.

  Examples of the cocatalyst used in the above reaction include phenolic hydroxyl group-containing compounds and alcoholic hydroxyl group-containing compounds. Examples of the solvent used in the above reaction include aromatics such as toluene and xylene, ketones such as methyl ethyl ketone and methyl isobutyl ketone, esters such as ethyl acetate and butyl acetate, propylene glycol methyl ether acetate, ethyl- Examples thereof include solvents inert to isocyanate groups, such as glycol ether esters such as 3-ethoxypropionate. Further, the reaction can be stopped by inactivating the catalyst with a reaction terminator. Examples of the reaction terminator include phosphoric acid, methyl paratoluenesulfonate, sulfur and the like.

  Examples of the hydrophilic compound for introducing a hydrophilic group into the polyisocyanate used in obtaining the self-emulsifying polyisocyanate (B1) include anions such as fatty acid salts, sulfonates, phosphate esters, and sulfate ester salts. Active compounds, primary amine salts, secondary amine salts, tertiary amine salts, quaternary ammonium salts, pyridinium salts and other cationic compounds, anionic compounds, nonionic compounds, amphoteric compounds such as sulfobetaines Can be mentioned.

  Examples of the nonionic compound for introducing a nonionic group into the polyisocyanate used for obtaining the self-emulsifying polyisocyanate (B1) include polyalkylene ether alcohols and polyalkylene fatty acid esters. Examples of the active hydrogen-containing compound used as an initiator when obtaining a polyalkylene ether alcohol include methanol, n-butanol, cyclohexanol, phenol, ethylene glycol, propylene glycol, aniline, trimethylolpropane, and glycerin. . Of these, lower alcohols are preferred from the viewpoint of water dispersion stability. Examples of the fatty acid used as an initiator when obtaining a polyalkylene fatty acid ester include acetic acid, propionic acid, butyric acid and the like, and among these, a lower fatty acid is preferable from the viewpoint of water dispersion stability.

  The number of alkylene oxide chains present in polyalkylene ether alcohol, polyalkylene fatty acid ester and the like is 3 to 90, preferably 5 to 50. Moreover, all the alkylene oxide chains may be composed of ethylene oxide chains, but may be composed of other alkylene oxide units such as ethylene oxide units and propylene oxide units in the entire alkylene oxide chains. In this case, considering the water dispersibility of the polyisocyanate, it is preferable to contain 70% by weight or more of ethylene oxide units.

  Examples of the higher alcohol for introducing a hydrophobic group into the polyisocyanate used for obtaining the self-emulsifying polyisocyanate (B1) include octyl alcohol, capryl alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol, Examples include lauryl alcohol, tridecyl alcohol, mystyryl alcohol, pentadecyl alcohol, cetyl alcohol, and cinnamyl alcohol.

  Furthermore, as the fatty acid as a raw material of the hydroxyl group-containing ester for introducing a hydrophobic group into the polyisocyanate used when obtaining the self-emulsifying polyisocyanate (B1), for example, α-oxypropionic acid, oxysuccinic acid, Dioxysuccinic acid, ε-oxypropane-1,2,3-tricarboxylic acid, hydroxyacetic acid, α-hydroxybutyric acid, hydroxystearic acid, ricinoleic acid, ricinoelaidic acid, ricinostearolic acid, salicylic acid, mandelic acid, etc. It is done. Examples of the hydroxyl group-containing compound as a raw material include methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, dodecyl alcohol, and lauryl alcohol.

  The self-emulsifying polyisocyanate (B1) is generally produced in the temperature range of 50 to 130 ° C. in the absence of a solvent, but an inert solvent, a catalyst or the like can also be used as necessary. Self-emulsifying polyisocyanates can improve water dispersion stability by introducing hydrophilic groups into the molecular chain. Furthermore, by introducing a lipophilic group having an appropriate length in consideration of the balance with the hydrophilic group, the reaction between the isocyanate group and water in water can be suppressed interfacially. Moreover, other various resin additives can be mix | blended with self-emulsification type polyisocyanate (B1) as needed. Examples of resin additives that can be blended include antioxidants, ultraviolet absorbers, heat resistance improvers, colorants, inorganic or organic fillers, plasticizers, lubricants, antistatic agents, reinforcing materials, and catalysts.

  The self-emulsifying polyisocyanate (B1) introduced with a hydrophilic group can be easily made into an aqueous dispersion by mixing with water. In the resulting aqueous dispersion, the isocyanate groups that exist relatively stably after being dispersed in water react with the active hydrogen present on the surface of the substrate, so that the adhesion to the substrate is extremely excellent, and the water resistance In addition, excellent paints and adhesives can be obtained. Further, after the self-emulsifying type polyisocyanate (B1) is dispersed in water, the polyisocyanate particles having a particle size of about 0.1 to 0.3 μm are in an emulsion state even after a considerable time has passed and the isocyanate group has disappeared. Therefore, the film obtained by applying this emulsion and drying at room temperature or drying by heating becomes hard and tough. However, when importance is attached to the adhesion to the substrate, it is desirable to use it within a period in which the isocyanate group does not disappear.

  As the self-emulsifying polyisocyanate (B1), a commercially available product that meets the object of the present invention can be obtained. Examples of commercially available self-emulsifying polyisocyanates (B1) that can be used in the present invention include Aquanate (trade names) 100, 110, 200, and 210 manufactured by Nippon Polyurethane Industry Co., Ltd.

  As the crosslinking agent (B) having an isocyanate group, an aqueous blocked isocyanate (B2) can also be used as in the self-emulsifying polyisocyanate (B1). As a method for obtaining the aqueous blocked isocyanate (B2), (1) in order to disperse the blocked isocyanate in water, for example, a method in which the blocked isocyanate is dispersed in water using a highly hydrophilic blocking agent such as sodium bisulfite, (2) A method in which a part of polyisocyanate is modified with a compound having a hydrophilic group and dispersed in water. The modification of the polyisocyanate of the above (1) with a hydrophilic group is carried out by using, for example, glycols having a hydrophilic group such as carboxylic acid such as dimethylolpropionic acid and dimethylolbutanoic acid, and polyethylene glycol. It is possible by a method of reacting hydrophilic polyols, and this reaction is carried out in the presence of a catalyst if necessary.

  Examples of the polyisocyanate used in the aqueous dispersion of blocked isocyanate include the same as those used in the above self-emulsifying polyisocyanate. In these polyisocyanates, isocyanate groups are blocked with a blocking agent to become blocked isocyanates. Examples of the blocking agent include active methylene compounds such as dimethyl malonate, diethyl malonate, methyl acetoacetate, ethyl acetoacetate, and acetylacetone, and oxime compounds such as formaldehyde, acetoaldoxime, acetone oxime, methylethylketoxime, and cyclohexanone oxime. These may be used alone or in combination of two or more.

  The blocking reaction can be performed in the presence or absence of a solvent. When using a solvent, it is necessary to use a solvent inert to the isocyanate group. As the solvent, those used in general urethanization reactions can be used. Moreover, when using a solvent, after dispersing blocked isocyanate in water, you may remove a solvent by a well-known method if necessary. In the blocking reaction, an organic metal salt such as tin, zinc, or lead, a tertiary amine, or the like can be used as a catalyst. The blocking reaction is performed in the temperature range of -20 to 150 ° C. If the isocyanate group is not blocked, it reacts with water or an active hydrogen-containing compound during storage and cannot participate in crosslinking, so that all isocyanate groups of the polyisocyanate are preferably blocked.

  The obtained blocked isocyanate is dispersed in water as necessary using a protective colloid such as an emulsifier and polyvinyl alcohol to obtain an aqueous blocked isocyanate (B2). When dispersing the blocked isocyanate in water, an emulsifier such as a homomixer or a homogenizer can be used.

  This aqueous blocked isocyanate (B2) can be easily obtained from commercially available products that meet the purpose of the present invention. Commercially available products suitable for the purpose include those manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Elastron (trade names) H-3, E-37, C-9, F-29, H-38, W-11, MF-25, and BN. -08, BN-11 and the like. Further, when using the aqueous blocked isocyanate (B2), a catalyst for promoting the reaction may be used. As the catalyst, for example, when using the commercially available product, Daiichi Kogyo Seiyaku Co., Ltd. Elastron catalyst (trade name) 64 can be used.

  When the water-based blocked isocyanate (B2) is blended with the urethane-based resin emulsion (A) having a carboxyl group, the resin component becomes an aqueous curable resin composition. When this aqueous curable resin composition is heated during use, the blocking agent is dissociated from the latent aqueous blocked isocyanate (B2), and the isocyanate group and the carboxyl group of the urethane resin in the urethane resin emulsion (A) A cross-linking reaction occurs to form a film (resin sheet or thin film) having excellent adhesion to the substrate, water resistance, solvent resistance and the like.

  In the resin composition according to the present invention, self-emulsifying polyisocyanate (B1) or aqueous blocked isocyanate (B2) is used as the crosslinking agent (B) having an isocyanate group in the urethane resin emulsion (A) having a carboxyl group. ), When the film (resin sheet or thin film) is formed, functional bonds are expressed in or between the urethane resin emulsion (A) particles, and the performance of the film can be remarkably improved. When the self-emulsifying polyisocyanate (B1) is used as the cross-linking agent (B), the isocyanate group of the self-emulsifying polyisocyanate (B1) is mixed with the urethane resin emulsion (A) immediately before use so that the urethane group Since it reacts with the carboxyl group in the resin of the particles of the resin-based resin emulsion (A), the adhesion between the film and the substrate, water resistance, solvent resistance, etc. are improved, which is suitable for use in paints and adhesives. . Moreover, when using aqueous | water-based blocked isocyanate (B2) as a crosslinking agent (B), the dissociated isocyanate group is rapidly and the carboxyl group in the resin particle of a urethane type resin emulsion (A) by heating at the time of use. react.

  The blending ratio of the urethane resin emulsion (A) and the crosslinking agent (B) is 1 to 50 parts by weight of the crosslinking agent (B) based on 100 parts by weight of the solid content of the urethane resin emulsion (A). Is preferable. When the blending amount of the crosslinking agent (B) is less than 1 part by weight, the water resistance of the film is deteriorated, and even when it exceeds 50 parts by weight, the effect of improving the water resistance is lost.

  In the resin composition according to the present invention, the silane coupling agent (C), which is an essential constituent component (hereinafter sometimes simply referred to as component (C)), has two or more different reactions in the molecule. An organosilicon compound having a group. Of the at least two reactive groups of the silane coupling agent (C), one is a reactive group that chemically bonds to inorganic substances such as glass and metal, and the other is bonded to the resin particles of the urethane resin emulsion (A). It is preferable to make it a reactive group. The reactive group bonded to the inorganic metal surface is not particularly limited. For example, the reactive group bonded to the resin particles of the urethane resin emulsion, which is an organic material, is, for example, a methoxy group or an ethoxy group. A glycid group, an amino group, an acrylic group, and the like.

  Examples of the silane coupling agent (C) include vinyltrimethoxysilane, vinyltriethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, and N- (2-aminoethyl) -3- Aminopropylmethylmethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, 3-glycyl Sidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylpentamethyldisiloxane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyldimethylethoxysilane, ( γ-glycidoxypropyl) -bis- (Trimethylsiloxy) methylsilane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane and the like. Of these, silane compounds having a glycidyl group or an amino group as a reactive group are preferred. Many of these silane coupling agents are commercially available and are readily available.

  The compounding quantity of a silane coupling agent (C) shall be chosen in the range of 0.1-5 weight part with respect to 100 weight part of solid content of a urethane type resin emulsion (A). When the blending amount is less than 0.1 parts by weight, there is no improvement effect such as adhesion to the film (resin sheet or thin film) and water resistance, and when it exceeds 5 parts by weight, the coatability is inferior and the water resistance of the film is remarkably improved. Since there is no effect, neither is preferable.

The resin composition used for the production of the resin sheet laminated metal plate according to the present invention is used as a main component such as a paint or an adhesive, and is particularly useful as an adhesive. When the resin composition used for the production of the resin sheet laminated metal plate according to the present invention is used as an adhesive, the resin composition can be used as it is, and depending on the use and purpose, various additives may be blended and used. it can. Additives that can be blended include pigments, fillers, aggregates, dispersants, dispersion stabilizers, wetting agents, thickeners, leveling agents, rheology control agents, antifoaming agents, plasticizers, film-forming aids, organic solvents , Antiseptics, pH adjusters, rust inhibitors, antioxidants, ultraviolet absorbers and the like. These additives may be used alone or in combination of two or more.

The adhesive comprising the resin composition used for the production of the resin sheet laminated metal plate according to the present invention is excellent in coatability on the surface of a metal plate such as a steel plate or plated steel plate, and excellent in adhesion to the surface of the metal plate, The film has excellent adhesion and water resistance, and also has excellent adhesion to organic substrates such as polyvinyl chloride resin film, so it can be used as an adhesive when producing resin sheet laminated metal plates such as resin laminated steel sheets. Are also used .

Examples of the metal plate to which the present invention can be applied include an iron plate, a steel plate, a tin plate, a tin-free steel plate, a brass plate, an aluminum plate, a stainless steel plate, or an alloy plate containing these as one component. The surface of these metal plates is subjected to chemical treatment such as chromic acid treatment, phosphoric acid treatment, chromic acid / phosphoric acid treatment, electrolytic chromic acid treatment, chromate treatment, or electrochemical treatment or physical treatment. It may be given. Although the thickness of a metal plate changes with uses, it is not specifically limited, Preferably it is 0.02-1 mm, More preferably, it is 0.1-0.6 mm.

  The method for applying the adhesive to the surface of the metal plate is not particularly limited, and any of an airless method, a spray method, a dipping method, a roll coating method, a brush coating method, and the like may be used. The thickness of the adhesive applied to the metal plate is preferably in the range of 1 to 10 μm, and after the application, drying treatment is performed at a temperature of 80 to 120 ° C. for several tens of seconds.

  The resin sheet laminated on the metal plate when adjusting the resin-laminated steel sheet is not particularly limited. For example, amorphous polyolefin such as polyethylene, polypropylene, ethylene-propylene copolymer, polybutene, and cyclic polyolefin Resin, polystyrene, ABS resin, styrene resin such as SBS, SEBS, polyvinyl chloride resin, polyvinylidene chloride resin, polymethyl methacrylate, polymethyl acrylate, copolymerized acrylic (meth) acrylate resin, polyurethane and other urethanes Resin, epoxy resin, polyester resin such as polyethylene terephthalate, polyethylene-2,6-naphthalate, polyamide resin such as polyamide 6, polyamide 12, copolymer polyamide, polyvinyl alcohol, ethylene-vinyl Polyvinyl alcohol resins such as alcohol copolymers, polyimide resins, polyetherimide resins, polysulfone resins, polyethersulfone resins, polyamideimide resins, polyetheretherketone resins, polycarbonate resins, polyvinyl butyral resins, polyarylate resins, ethylene -Tetrafluoroethylene copolymer, Trifluoroethylene chloride polymer, Tetrafluoroethylene- Hexafluoropropylene copolymer, Tetrafluoroethylene-Perfluoroalkoxyethylene copolymer, Polyvinyl fluoride, Polyvinylidene fluoride , A fluororesin such as perfluoroethylene-perfluoropropylene-perfluorovinyl ether terpolymer, or a blend thereof.

  Moreover, various additives can be mix | blended with the said raw material resin according to the use and the objective of a resin sheet. Examples of the additive include pigments, fillers, plasticizers, antioxidants, ultraviolet absorbers, antistatic agents, lubricants, and the like, and they are used alone or in combination as appropriate. Examples of the resin sheet include a single layer or a laminated sheet of two or more layers. These resin sheets may be unstretched or may be stretched uniaxially or axially. The resin sheet preferably has a thickness in the range of 5 to 500 μm. Further, the resin sheet may be subjected to a known surface treatment such as corona discharge treatment, plasma treatment, flame treatment, chemical treatment, and further polar polymer coating treatment, color pattern printing, embossing, etc. It may be given.

  The method for laminating the resin sheet on the metal plate is not particularly limited, and can be produced by a conventionally known method. As a conventionally known method, for example, (1) A die such as a coat hanger die, a T die, or an I die is provided at the tip of the extruder, a raw material resin is melted by the extruder, and a sheet (thin film) A so-called extrusion laminating method in which the surface of the metal plate is coated while being extruded into a shape, and (2) a method in which a sheet is prepared in advance and this sheet is pressure-bonded onto a heated metal plate with a nip roll or the like.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited to the example described below. In the examples, “parts” means parts by weight.

[Example 1]
<Preparation of resin composition emulsion>
Urethane resin emulsion having a carboxyl group as a hydrophilic group {component (A), manufactured by Sanyo Kasei Kogyo Co., Ltd., trade name: U-coat UWS145}, 100 parts of self-emulsifying polyisocyanate {component (B1), Japan Made by Polyurethane Industry Co., Ltd., trade name: Aquanate 100} 15 parts, and 0.5 part of 3-glycidoxypropyltrimethoxysilane (Nihon Unicar Co., A187) as a silane coupling agent (component C) A resin composition emulsion was prepared.

<Preparation of resin laminated steel sheet>
The liquid emulsion of the obtained resin composition is diluted with water to a solid content concentration of 10% by weight, and the film thickness after drying is 3 μm on a hot-dip galvanized steel sheet having a thickness of 0.45 mm by roll coating. It was applied to. Separately, a soft PVC film having a thickness of 150 μm was prepared by adding 30 parts of a plasticizer, a stabilizer, and a pigment in terms of DOP to 100 parts of polyvinyl chloride (PVC) having a polymerization degree of 1000. . The application of the steel sheet was heated to 220 ° C., and the soft PVC film was pressure-bonded to one side of the steel sheet with a nip roll to prepare a PVC resin laminated steel sheet. The obtained PVC resin laminated steel sheet was subjected to a property evaluation test by the method described below, and the results are shown in Table-1.

<Method for evaluating characteristics of resin-laminated steel sheet>
Evaluation items and evaluation methods for various properties of the resin-laminated steel sheet are as follows.
(1) Coatability: When the resin composition emulsion prepared by the above method is applied on the surface of the metal plate by the roll coating method so that the thickness of the solid content is 3 μm, the coating solution is repelled on the surface of the metal plate. Visual observation was performed. The case where no abnormality was observed in the appearance was judged as “◯”, and the case where abnormality was found in the appearance was judged as “X”.
(2) Initial adhesion: From a PVC resin-laminated steel sheet, a test piece having a size of 30 mm × 120 mm was cut out, and the PVC film part of this test piece was 20 mm wide and peeled at 50 mm / min from the steel sheet surface. Peeled in the direction of 180 degrees. The maximum load at the time of peeling is taken as the peel strength. The peel strength is 40N / 20mm width or more when the material breaks, ○, 30N / 20mm width or more and less than 40N / 20mm width, Δ, 30N / 20mm width Those not present were judged as x.

(3) Adhesiveness after hot water test: A test piece having a size of 30 mm × 120 mm was cut out from the PVC resin laminated steel sheet prepared by the above method, and this test piece was dipped in boiling water for 5 hours and pulled up. The adhesion of the PVC film was evaluated in the same manner as in (2) above. Peel strength ○ more than a 30 N / 20 mm width, which is less than 30 N / 20 mm width 25 N / 20 mm width or more △, and × those less than 25 N / 20 mm width, and determination. The excellent adhesion after the hot water test means that the water resistance is also excellent.
(4) Adhesion after processing: A PVC resin laminated steel sheet prepared in the same manner as in (2) above was cut into a 30 mm × 120 mm size test piece, and two horizontal lines were cut into this test piece at intervals of 50 mm. Was drawn and uniaxially stretched until the distance between the horizontal lines reached 60 mm. Using this as a sample, the adhesion between the metal plate and the PVC film was evaluated by the same method as in (2) above. Those having a peel strength of 30 N / 20 mm width or more were evaluated as “◯”, and those having a peel strength of less than 30 N / 20 mm width as “X”. In this test, since the adhesiveness between the steel sheet and the PVC film is lowered by stretching the PVC resin laminated steel sheet, the adhesiveness (peelability) at the time of drawing can be evaluated.
(5) Comprehensive evaluation: evaluated by comprehensively considering the results of the evaluation items (1) to (4).

[Example 2]
In the example described in Example 1, the crosslinking agent {component (B)} was mixed with 30 parts of an aqueous blocked isocyanate (B2) (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: Elastron BN-08), and a catalyst for blocked isocyanate ( Daiichi Kogyo Seiyaku Co., Ltd., trade name: Elastron Catalyst 64) A PVC resin laminated steel sheet was prepared in the same procedure as in the same example except that the combination was changed to 0.5 part. The obtained PVC resin laminated steel sheet was evaluated by the above method, and the results are shown in Table-1.

[Comparative Example 1]
In the example described in Example 1, except that the cross-linking agent {component (B)} was replaced with 5 parts of melamine resin (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumimar 40WT), the same procedure as in the same example, A PVC resin laminated steel sheet was prepared. The obtained PVC resin laminated steel sheet was evaluated by the above method, and the results are shown in Table-1.

[Comparative Example 2]
In the example described in Example 1, except that the urethane resin emulsion {component (A)} is replaced with a polyester resin emulsion having a carboxyl group (manufactured by Toyobo Co., Ltd., trade name: Vylonal MD1250), A PVC resin laminated steel sheet was created in the same procedure. The obtained PVC resin laminated steel sheet was evaluated by the above method, and the results are shown in Table-1.

[Comparative Example 3]
In the example described in Example 1, except that the urethane resin emulsion {component (A)} is replaced with a urethane resin emulsion having a polyethylene oxide (trade name: Superflex 500, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), A PVC resin laminated steel sheet was prepared in the same procedure as in the example. The obtained PVC resin laminated steel sheet was evaluated by the above method, and the results are shown in Table-1.

[Comparative Example 4]
In the example described in Example 1, a PVC resin laminated steel sheet was prepared in the same procedure as in the same example except that the silane coupling agent {component (C)} was not added. The obtained PVC resin laminated steel sheet was evaluated by the above method, and the results are shown in Table-1.

[Example 3]
In the example described in Example 1, except that the silane coupling agent {component (C)} was replaced with γ-aminopropyltriethoxysilane (manufactured by Nihon Unicar Co., Ltd., brand name: A1100), the same as in the example A PVC resin laminated steel sheet was prepared by the procedure described above. The obtained PVC resin laminated steel sheet was evaluated by the above method, and the results are shown in Table-2.

[Example 4]
In the example described in Example 1, except that the silane coupling agent {component (C)} was replaced with 3-methacryloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., brand name: KBM503) A PVC resin laminated steel sheet was prepared in the same procedure as above. The obtained PVC resin laminated steel sheet was evaluated by the above method, and the results are shown in Table-2.

[Example 5]
In the example described in Example 1, except that the silane coupling agent {component (C)} is replaced with 3-mercaptopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., brand name: KBM803) A PVC resin laminated steel sheet was created in the same procedure. The obtained PVC resin laminated steel sheet was evaluated by the above method, and the results are shown in Table-2.

[Example 6]
In the example described in Example 1, a PVC resin laminated steel sheet was prepared in the same procedure as in the same example except that the addition amount of the silane coupling agent {component (C)} was changed to 0.1 part. . The obtained PVC resin laminated steel sheet was evaluated by the above method, and the results are shown in Table-2.

[Example 7]
In the example described in Example 1, a PVC resin laminated steel sheet was prepared in the same procedure as in the same example except that the addition amount of the silane coupling agent {component (C)} was changed to 1 part. The obtained PVC resin laminated steel sheet was evaluated by the above method, and the results are shown in Table-2.

[Comparative Example 5]
In the example described in Example 1, except that 0.5 part of the addition amount of the silane coupling agent {component (C)} was changed to 8 parts, the PVC resin laminated steel sheet was prepared in the same procedure as in the example. Created. The obtained PVC resin laminated steel sheet was evaluated by the above method, and the results are shown in Table 2.

From Table-1 and Table-2, the following is clear.
(1) Self-emulsifying polyisocyanate (B1) or aqueous blocked isocyanate (B2) is added to urethane resin emulsion (A) having a carboxyl group, and 3-glycidoxypropyltrimethoxysilane is used as silane coupling agent (C). When the resin composition is used as an adhesive by adhering within the range specified in claim 1 and is used for adhesion between the soft PVC film and the steel sheet, the obtained PVC laminated steel sheet is subjected to initial adhesion and hot water test. Excellent adhesion (water resistance), adhesion after processing, etc. (see Examples 1 and 2).
(2) On the other hand, when the component (C) is changed to a melamine compound not specified in claim 1, the PVC resin laminated steel sheet has low initial adhesion and adhesion after a hot water test (water resistance). Inferior in adhesion after processing (see Comparative Example 1).
(3) Even if it is a resin emulsion having a carboxyl group, if it is a polyester resin emulsion having a carboxyl group that is not a urethane resin emulsion, the PVC resin-laminated steel sheet has good initial adhesion, and adhesion after a hot water test ( Water resistance) and poor adhesion after processing (see Comparative Example 2).
(4) Even if it is a urethane-based resin emulsion, if it is a urethane-based resin emulsion having a polyethylene oxide that is not a carboxyl group, the PVC resin-laminated steel sheet has low initial adhesion, and adhesion after hot water testing (water resistance), Poor adhesion after processing (see Comparative Example 3).

(5) Even when the urethane-based resin emulsion (A) having a carboxyl group and the self-emulsifying type polyisocyanate (B1) are used, when the silane coupling agent (C) is not added, the PVC resin laminated steel sheet has an initial adhesiveness. Although excellent in adhesion after processing, it is inferior in adhesion (water resistance) after a hot water test (see Comparative Example 4).
(6) Even if a silane coupling agent having an amino group is used as the silane coupling agent (C) in Example 1, the PVC resin laminated steel sheet has the same initial adhesiveness and heat as in Example 1. The adhesion after water test (water resistance) and the adhesion after processing are excellent (see Example 3).
(7) Even if it is a silane coupling agent (C), those in which the functional groups are methacryloxy and mercapto groups are those in Example 1 using a silane coupling agent having a glycidyl group, and a silane coupling agent having an amino group Compared with the one in Example 3 using the same, the adhesion after the hot water test and water resistance are slightly inferior, but the adhesion after the hot water test is improved as compared with the one in Comparative Example 4 in which no silane coupling agent is added. (See Example 4 and Example 5).
(8) When the silane coupling agent (C) is blended within the range specified in claim 1 to the resin component containing the urethane-based resin emulsion (A) having a carboxyl group and the self-emulsifying polyisocyanate (B1). The PVC resin laminated steel sheet is excellent in initial adhesion, adhesion after a hot water test, adhesion after processing, and water resistance (see Examples 6 and 7).
(9) However, when the silane coupling agent (C) is blended beyond the range specified in claim 1, the coatability when creating a PVC resin laminated steel sheet is remarkably inferior. Despite the high peel strength, the coatability is poor and the adhesion after the hot water test is poor (see Comparative Example 5).

The adhesive comprising the resin composition used for producing the resin sheet laminated metal plate according to the present invention is excellent in coatability and can form a film excellent in adhesion to the metal plate , water resistance and chemical resistance. Therefore, it is suitable for use as a solventless paint or adhesive. In the resin sheet laminated metal plate according to the present invention, the metal plate and the resin sheet are firmly bonded, and are excellent in water resistance (adhesion after hot water test) and workability (adhesion after processing). It is suitable for various uses of sheet-laminated metal plates, particularly for resin-laminated metal plates having design properties, or for manufacturing parts around water.

Claims (8)

The urethane resin emulsion (A) in which the silane coupling agent (C) is added to the resin component comprising the urethane resin emulsion (A) having a carboxyl group and the crosslinking agent (B) having an isocyanate group. A metal sheet and a resin sheet mainly composed of polyvinyl chloride are laminated via a laminating adhesive mainly composed of a resin composition blended in an amount of 0.1 to 5 parts by weight with respect to 100 parts by weight solids. A resin sheet laminated metal plate, characterized by comprising: 2. The resin sheet laminated metal plate according to claim 1, wherein the resin sheet laminated metal plate has a peel strength of 25 N / 20 mm width or more according to evaluation of adhesion after a hot water test described below.
Adhesion after hot water test: A test piece of 30 mm × 120 mm in size was cut out from the resin sheet laminated metal plate, and this test piece was immersed in boiling water for 5 hours and pulled up. The resin sheet portion of this test piece was 20 mm wide. The maximum load when peeling from the steel sheet surface in the direction of 180 degrees under the peeling speed of 50 mm / min is defined as peeling strength. The resin sheet laminated metal plate according to claim 1 or 2, wherein the resin sheet laminated metal plate has a peeling strength of 30 N / 20 mm width or more according to the following post-processing adhesion evaluation.
Adhesion after processing: Cut the resin sheet laminated metal plate into a 30 mm x 120 mm test piece, draw two horizontal lines at an interval of 50 mm on this test piece, and stretch it uniaxially until the distance between the horizontal lines reaches 60 mm The maximum load when the resin sheet portion of the test piece is 20 mm wide and peeled from the steel sheet surface in the direction of 180 degrees under the condition of a peeling speed of 50 mm / min is defined as the peel strength. The resin sheet laminated metal plate according to any one of claims 1 to 3, wherein the resin sheet laminated metal plate has a peel strength of 40 N / 20 mm width or more according to the following evaluation of initial adhesion.
Initial adhesion: The resin sheet laminated metal plate was cut into a 30 mm × 120 mm size test piece, and the resin sheet portion of the test piece was 20 mm wide and peeled at a peel rate of 50 mm / min. The maximum load at the time of peeling is defined as peeling strength.   Urethane resin emulsion (A) is a polymer polyol (a) having a number average quantity of 300 to 5000, a compound (b) having two or more hydroxyl groups and one or more carboxyl groups, an organic polyisocyanate (c), and necessary An anionic self-emulsifying urethane resin obtained by further emulsifying a urethane resin synthesized from a chain extender (d) and / or a polymerization terminator (e) in water with a salt forming agent (f) The resin sheet laminated metal plate according to any one of claims 1 to 4, which is an emulsion.     The resin sheet laminated metal plate according to any one of claims 1 to 5, wherein the silane coupling agent (C) is a silane coupling agent having a glycidyl group or a silane coupling agent having an amino group.     The resin sheet laminated metal plate according to any one of claims 1 to 6, wherein the crosslinking agent (B) having an isocyanate group is a self-emulsifying polyisocyanate.     The resin sheet laminated metal plate according to any one of claims 1 to 7, wherein the crosslinking agent (B) having an isocyanate group is an aqueous blocked isocyanate.