JP2012092311A - Primer coating agent and laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a primer coating agent formable of a primer layer which is excellent in adhesion to a substrate and a top coat layer, etc., and water resistance such as wet adhesion and water whitening resistance.SOLUTION: The primer coating agent contains: urethane resin (C) having an acid value of 16 to 40 and an aqueous medium (D). The urethane resin (C) is obtained by reacting polyol (A) including polyol (a1) containing aliphatic cyclic structure, polyester polyol (a2) containing aromatic structure, and hydrophilic group-containing polyol (a3) with polyisocyanate (B) including polyisocyanate (b1) containing aliphatic cyclic structure.

Description

  The present invention relates to a primer coating agent that can be used for surface coating of various substrates including plastic substrates and metal substrates.

  Coating agents are used in various applications including home appliances, building members, and automobiles for the purpose of imparting design properties to various substrate surfaces and protecting the substrate surfaces.

  As the application field of the coating agent becomes wide as described above, the characteristics required for the coating agent also vary widely.

  For example, in surface coating applications such as optical members and home appliances, for the purpose of imparting stain resistance, fog resistance, fingerprint resistance, etc., and for building exterior applications, for the purpose of imparting stain resistance, etc. There is a need for a coating agent capable of forming a highly hydrophilic film.

  However, since the hydrophilic film formed using the coating agent is generally not sufficient in terms of adhesion to various substrates, it causes peeling of the hydrophilic film over time, and as a result, the contamination resistance, etc. There was a case of causing a significant decrease in

  Therefore, as a method for improving the adhesion of the hydrophilic film to the substrate, a method of providing a primer layer between the substrate and the hydrophilic film is known. As a primer coating agent capable of forming such a primer layer, for example, a polyester polyol, a polyisocyanate composed of an acid component and a glycol component composed of a specific proportion of aromatic dicarboxylic acid and aliphatic (ring) dicarboxylic acid, and necessary A high molecular weight product obtained by reacting a chain extender according to the above, and containing 0.5 to 5% by weight of a pendant carboxyl group in the high molecular weight material, and the carboxyl group is neutralized with ammonia or an organic amine A primer coating agent containing a water-based polyester polyurethane resin is known (see, for example, Patent Document 1).

  By providing the primer layer as described above, the adhesion of the hydrophilic film to the substrate was improved in each stage.

  However, the hydrophilic film is highly compatible with water such as moisture, and in applications such as optical members, home appliances, and exterior buildings, condensation that may occur due to heat of the backlight, etc., or temperature differences in the atmosphere, etc. In addition, since there are many opportunities to come into contact with moisture such as rainwater and moisture, the primer layer causes swelling and the like due to the influence of the water, and causes water layer peeling and whitening of the primer layer. Sometimes it was not enough.

  Further, in the above applications, the hydrophilic coating is often exposed to a relatively high temperature of about 50 ° C. to 80 ° C., and when exposed to the high temperature in a state where the water or the like is in contact, the hydrophilic coating is still used. In some cases, it may cause peeling.

JP 61-228030 A

  The problem to be solved by the present invention is to provide a primer coating agent capable of forming a primer layer excellent in water resistance such as adhesion to a base material or top coat layer, water resistance adhesion and water whitening resistance. is there.

  In order to improve the base material adhesion, the present inventors considered that it is effective to use a resin having an aromatic structure as a resin constituting the primer layer. The investigation was advanced based on the primer coat described in Patent Document 1.

  Specifically, an investigation was made of a primer coating agent containing a urethane resin having a combination of the aromatic structure and an aliphatic cyclic structure that is thought to contribute to the improvement of water resistance.

  With the primer coating agent, although a primer layer having relatively good substrate adhesion could be formed, the required performance was not reached one step further in terms of water resistance. Moreover, the said water resistance fall was seen under comparatively high temperature.

  Therefore, the present inventors have examined various combinations as the polyol and polyisocyanate constituting the urethane resin, and include an aliphatic cyclic structure-containing polyol, an aromatic structure-containing polyester polyol, and a hydrophilic group-containing polyol. Among the urethane resins obtained by combining and reacting polyols and polyisocyanates containing aliphatic cyclic structure-containing polyisocyanates, a primer coating agent containing a urethane resin having a specific acid value of 16 to 40, It has been found that the problems of the present invention can be solved.

  That is, the present invention relates to a polyol (A) containing an aliphatic cyclic structure-containing polyol (a1), an aromatic structure-containing polyester polyol (a2), and a hydrophilic group-containing polyol (a3), and an aliphatic cyclic structure. Primer coat characterized by containing urethane resin (C) having an acid value of 16 to 40 obtained by reacting polyisocyanate (B) containing polyisocyanate (b1), and aqueous medium (D) It relates to the agent.

  Since the primer coating agent of the present invention can form a film having excellent adhesion and water resistance to a substrate and the like, for example, a metal substrate such as a steel plate, ABS resin, PC resin, ABS / PC resin, PS resin And a primer layer provided between a plastic substrate such as PMMA resin and the topcoat layer.

  Specifically, the primer coating agent is a heat exchanger such as an air conditioner or a refrigerator, an antireflection film that requires antifouling properties and antifogging properties, an optical filter, an optical lens, an eyeglass lens, an optical member such as a mirror. It can be used for forming a primer layer when painting home appliances such as home appliances and displays, automobile interior materials and exterior materials, and building members such as wall materials and roof materials.

  In addition, the primer coating agent of the present invention includes, for example, galvanized steel sheets such as galvanized steel sheets and aluminum-zinc alloy steel sheets, and rust of metal substrates such as aluminum plates, aluminum alloy plates, electromagnetic steel plates, copper plates, and stainless steel plates. Because it can form a coating with excellent corrosion resistance that can be prevented from occurring, it can be used for surface coating of building parts such as outer walls and roofs, civil engineering members such as guardrails, soundproof walls, and drainage grooves, home appliances, industrial machinery, and automotive parts. It can be used as a coating agent.

  The primer coating agent of the present invention comprises a polyol (A) containing an aliphatic cyclic structure-containing polyol (a1), an aromatic structure-containing polyester polyol (a2), and a hydrophilic group-containing polyol (a3), and an aliphatic ring. Urethane resin (C) having an acid value of 16 to 40 obtained by reacting polyisocyanate (B) containing polyisocyanate (b1) having the formula structure, aqueous medium (D), and other additives as required The urethane resin (C) can be dissolved or dispersed in the aqueous medium (D).

  The urethane resin (C) used in the present invention includes an aliphatic cyclic structure-containing polyol (a1) and an aliphatic cyclic structure derived from an aliphatic cyclic structure-containing polyisocyanate (b1), and an aromatic structure-containing polyester polyol. Those having a combination of the aromatic structure derived from (a2) and a hydrophilic group are used.

  Specifically, the urethane resin (C) is a polyol (A) containing an aliphatic cyclic structure-containing polyol (a1), an aromatic structure-containing polyester polyol (a2), and a hydrophilic group-containing polyol (a3). And a polyisocyanate (B) containing an aliphatic cyclic structure-containing polyisocyanate (b1) is obtained by a combination reaction.

  Here, the aliphatic cyclic structure of the urethane resin (C) includes the aliphatic cyclic structure-containing polyol (a1) and the aliphatic cyclic structure-containing polyisocyanate as the polyol (A) and the polyisocyanate (B). It is important to be introduced into the urethane resin (C) by using a combination of (b1).

  Here, instead of the urethane resin (C), a urethane resin obtained by using only one of the aliphatic cyclic structure-containing polyol (a1) and the aliphatic cyclic structure-containing polyisocyanate (b1) is used. In some cases, the primer coating agent that is included cannot form a primer layer excellent in water resistance such as water-resistant adhesion and water whitening resistance.

  Examples of the aliphatic cyclic structure include a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a propylcyclohexyl group, a tricyclo [5,2,1,0,2,6] decyl group, and a bicyclo [4]. , 3,0] -nonyl group, tricyclo [5,3,1,1] dodecyl group, propyltricyclo [5,3,1,1] dodecyl group, norbornene group, isobornyl group, dicyclopentanyl group, adamantyl Groups and the like. Of these, a cyclohexyl group, a norbornene group, an isobornyl group, and an adamantyl group are preferable because a primer layer having excellent substrate adhesion and water resistance can be formed, and a cyclohexyl group is more preferable.

  The aliphatic cyclic structure is preferably included in the range of 10% by mass to 40% by mass with respect to the total amount of the urethane resin (C) in order to form a primer layer excellent in adhesion and water resistance. . The ratio of the aliphatic cyclic structure derived from the aliphatic cyclic structure-containing polyol (a1) to the total amount of the urethane resin (C) is in the range of 0.1% by mass to 35% by mass. It is preferable for forming a film having excellent substrate adhesion and water resistance and having good substrate followability. The content of the aliphatic cyclic structure is the mass of the aliphatic cyclic structure contained in the aliphatic cyclic structure-containing polyol (a1) and the aliphatic cyclic structure-containing polyisocyanate (b1). (C) A value calculated by dividing by the total mass.

  In addition, it is important that the aromatic structure of the urethane resin (C) is introduced into the urethane resin (C) by using the aromatic structure-containing polyester polyol (a2) as the polyol (A). is there.

  In the primer coat agent containing the urethane resin obtained by using the aromatic structure-containing polyisocyanate, for example, without using the aromatic structure-containing polyester polyol (a2) instead of the urethane resin (C), In some cases, it is not possible to form a primer layer having excellent adhesion to water and the like and water-resistant adhesion. The aromatic structure may be introduced into the urethane resin (C) by using the aromatic structure-containing polyisocyanate in combination with the aromatic structure-containing polyester polyol (a2).

  Moreover, the ratio of the aromatic structure derived from the said aromatic structure containing polyester polyol (a2) which the said urethane resin (C) has is the range of 5 mass%-30 mass% with respect to the whole quantity of the said urethane resin (C). It is preferable that The content of the aromatic structure is calculated by dividing the mass of the aromatic structure contained in the aromatic structure-containing polyol (a2) and the aromatic structure-containing polyisocyanate by the total mass of the urethane resin (C). It is the value.

  Moreover, as said urethane resin (C), what has a hydrophilic group from a viewpoint which provides the favorable water dispersion stability in an aqueous medium (D), and obtains the aqueous resin composition excellent in storage stability. It is preferable to use it.

  As the hydrophilic group, an anionic group, a cationic group, and a nonionic group can be used. Among them, an anionic group or a cationic group is preferably used, and an anionic group is more preferably used. .

  As the anionic group, for example, a carboxyl group, a sulfonic acid group, a carboxylate group, a sulfonate group, or the like in which part or all of them are neutralized with a basic compound or the like can be used. Of these, the use of a carboxyl group or a carboxylate group is preferable for imparting good water dispersibility.

  Examples of basic compounds that can be used for neutralization of the anionic group include organic amines such as ammonia, triethylamine, pyridine, morpholine, alkanolamines such as monoethanolamine, Na, K, Li, and Ca. A metal base compound etc. are mentioned.

  Moreover, as said cationic group, a tertiary amino group etc. can be used, for example. The tertiary amino group may be partially or entirely neutralized with acetic acid or propionic acid.

  Examples of the nonionic group include a polyoxyethylene group, a polyoxypropylene group, and a polyoxyethylene-polyoxypropylene group.

  The hydrophilic resin such as the anionic group and the cationic group is present in the range of 50 mmol / kg to 1000 mmol / kg with respect to the entire urethane resin (C). ) Is preferable for imparting good water dispersion stability.

Moreover, as said urethane resin (C), it is essential to use the thing which has the acid value of the range of 16-40, and there exists an effect of this invention. Here, the said acid value is 15. If it is 41 or 41, the effects of the present invention may not be achieved.
The acid value is preferably in the range of 20-30, and more preferably in the range of 20-25. In addition, the acid value said by this invention is the theoretical value computed based on the usage-amount of acid group containing compounds, such as a carboxyl group containing polyol used for manufacture of the said urethane resin (C).

  The urethane resin (C) as described above preferably uses a resin having a weight average molecular weight in the range of 10,000 to 500,000 in order to form a film having both excellent adhesion and water resistance. It is more preferable to use those having a weight average molecular weight in the range of 200,000, and it is particularly preferable to use a weight average molecular weight in the range of 20000 to 100,000.

  The urethane resin (C) includes the polyol (A) containing the aliphatic cyclic structure-containing polyol (a1), the aromatic structure-containing polyester polyol (a2), and the hydrophilic group-containing polyol (a3), and an aliphatic group. A polyisocyanate (B) containing a cyclic structure-containing polyisocyanate (b1) can be used in combination, and the polyol (A) and the polyisocyanate (B) can be reacted by a conventionally known method. .

  As the polyol (A), the aliphatic cyclic structure-containing polyol (a1), the aromatic structure-containing polyester polyol (a2), and the hydrophilic group-containing polyol (a3) are used as essential components. Other polyols can be used in combination.

  Examples of the aliphatic cyclic structure-containing polyol (a1) include cyclobutanediol, cyclopentanediol, 1,4-cyclohexanediol, cycloheptanediol, cyclooctanediol, cyclohexanedimethanol, hydroxypropylcyclohexanol, tricyclo [5, 2,1,0,2,6] decane-dimethanol, bicyclo [4,3,0] -nonanediol, dicyclohexanediol, tricyclo [5,3,1,1] dodecanediol, bicyclo [4,3, 0] nonanedimethanol, tricyclo [5,3,1,1] dodecane-diethanol, hydroxypropyltricyclo [5,3,1,1] dodecanol, spiro [3,4] octanediol, butylcyclohexanediol, 1, 1'-bicyclohexylidene Ol, cyclohexane triol, hydrogenated bisphenol - Le A, such as 1,3-adamantane-diol, generally be used 100 to 500 as low molecular weight aliphatic cyclic structure-containing polyol (a1-1) preferably. Among these, it is preferable to use cyclohexanedimethanol for forming a primer layer having excellent adhesion and water resistance. The molecular weight of the aliphatic cyclic structure-containing polyol is based on the formula weight.

  When using the aliphatic cyclic structure-containing polyol (a1-1) having a low molecular weight of about 100 to 500, the aliphatic cyclic structure-containing polyol (a1-1) is derived from the total amount of the urethane resin (C). The ratio of the aliphatic cyclic structure is preferably in the range of 0.1% by mass to 10% by mass in order to form a primer layer excellent in substrate adhesion and water resistance.

  The aliphatic cyclic structure-containing polyol (a1) contains an aliphatic cyclic structure obtained by reacting the low molecular weight aliphatic cyclic structure-containing polyol (a1-1) with other components. Polycarbonate polyols, aliphatic cyclic structure-containing polyester polyols, aliphatic cyclic structure-containing polyether polyols, and the like can be used.

  As the aliphatic cyclic structure-containing polycarbonate polyol, for example, a product obtained by reacting the low molecular weight aliphatic cyclic structure-containing polyol (a1-1) with dimethyl carbonate, phosgene or the like may be used. it can.

  As said aliphatic cyclic structure containing polycarbonate polyol, it is preferable to use the aliphatic cyclic structure containing polycarbonate polyol which has a number average molecular weight of 800-3000, and what has a number average molecular weight of 800-2000 is used. Is more preferable.

Examples of the aliphatic cyclic structure-containing polyester polyol include those obtained by esterifying the aliphatic cyclic structure-containing polyol (a1-1) and a polycarboxylic acid, and chain aliphatic polyols. Or an aromatic polyol and an aliphatic cyclic structure-containing polycarboxylic acid obtained by esterification reaction can be used.
Examples of the polycarboxylic acid that can be esterified with the aliphatic cyclic structure-containing polyol (a1-1) include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic acid, fumaric acid, 1, 3-Cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, and anhydrides or ester-forming derivatives thereof can be used.
Examples of the chain aliphatic polyol include ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, and 3-methylpentanediol. it can. As said aromatic polyol, bisphenol compounds, such as bisphenol A and bisphenol F, those alkylene oxide adducts, etc. can be used, for example.
Examples of the aliphatic cyclic structure-containing polycarboxylic acid that can be esterified with the chain aliphatic polyol or aromatic polyol include 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and anhydrides thereof. Things can be used.

  In addition, as the aliphatic cyclic structure-containing polyether polyol, for example, the low molecular weight aliphatic cyclic structure-containing polyol (a1-1) is used as an initiator, and an alkylene oxide such as ethylene oxide or propylene oxide is added. A polymerized product can be used.

  The amount of the aliphatic cyclic structure-containing polyol (a1) used is in the range of 0.1% by mass to 40% by mass with respect to the total amount of the polyol (A) used for the production of the urethane resin (C). It is preferable.

  Moreover, as an aromatic structure containing polyester polyol (a2) used for the said polyol (A), what has a 1 or more aromatic ring structure in a molecule | numerator is used.

  Adhesion can be improved by using the aromatic structure-containing polyester polyol (a2) and introducing the aromatic structure derived from the (a2) into the urethane resin (C).

  As said aromatic structure containing polyester polyol (a2), what is obtained by esterifying a polyol and polycarboxylic acid can be used, for example.

Examples of the polyol include aliphatic polyols such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol and neopentyl glycol, bisphenol compounds such as bisphenol A and bisphenol F, and the like. Low molecular polyols such as alkylene oxide adducts can be used.
Can be used.

  Examples of the polycarboxylic acid include aliphatic polycarboxylic acids such as succinic acid, adipic acid, sebacic acid, and dodecanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, and anhydrides or esterified products thereof. Aromatic polycarboxylic acids can be used.

  As the combination of the polyol and the polycarboxylic acid, it is essential to use one having one or both having an aromatic structure. Specifically, examples of the aromatic structure-containing polyester polyol (a2) include aliphatic polyols such as ethylene glycol, diethylene glycol, and 1,4-butanediol, and aromatic polycarboxylic acids such as terephthalic acid, isophthalic acid, and phthalic acid. It is preferable to use what is obtained by combining and reacting with an acid.

  As said aromatic structure containing polyester polyol (a2), since the adhesiveness with respect to the base material etc. of the film | membrane obtained can further be improved, it is preferable to use what has a number average molecular weight of 500-5000.

  The aromatic structure-containing polyester polyol (a2) is preferably used in the range of 50% by mass to 95% by mass with respect to the total amount of the polyol (A) used in the production of the urethane resin (C).

  Moreover, as said hydrophilic group containing polyol (a3) used for the said polyol (A), hydrophilic groups other than the said aliphatic cyclic structure containing polyol (a1) and the said aromatic structure containing polyester polyol (a2). For example, an anionic group-containing polyol, a cationic group-containing polyol, and a nonionic group-containing polyol can be used. Especially, it is preferable to use an anionic group containing polyol or a cationic group containing polyol, and it is more preferable to use an anionic group containing polyol.

  As the anionic group-containing polyol, for example, a carboxyl group-containing polyol or a sulfonic acid group-containing polyol can be used.

  Examples of the carboxyl group-containing polyol include 2,2′-dimethylolpropionic acid, 2,2′-dimethylolbutanoic acid, 2,2′-dimethylolbutyric acid, 2,2′-dimethylolvaleric acid, and the like. Among them, it is preferable to use 2,2′-dimethylolpropionic acid. Moreover, the carboxyl group-containing polyester polyol obtained by making the said carboxyl group-containing polyol and various polycarboxylic acids react can also be used.

  Examples of the sulfonic acid group-containing polyol include dicarboxylic acids such as 5-sulfoisophthalic acid, sulfoterephthalic acid, 4-sulfophthalic acid, and 5 [4-sulfophenoxy] isophthalic acid, and salts thereof, and the aromatic structure-containing polyester. The polyester polyol obtained by making it react with the low molecular weight polyol illustrated as what can be used for manufacture of a polyol (a2) can be used.

  The carboxyl group-containing polyol and the sulfonic acid group-containing polyol are preferably used in the range where the acid value of the urethane resin (C) is 16 to 40, and more preferably in the range of 20 to 30.

  The anionic groups are preferably partially or wholly neutralized with a basic compound or the like in order to exhibit good water dispersibility.

  Examples of basic compounds that can be used for neutralizing the anionic group include organic amines having a boiling point of 200 ° C. or higher, such as ammonia, triethylamine, morpholine, monoethanolamine, and diethylethanolamine, NaOH, KOH, and LiOH. A metal hydroxide containing etc. can be used. The basic compound is preferably used in the range of basic compound / anionic group = 0.5 to 3.0 (molar ratio) from the viewpoint of improving the water dispersion stability of the resulting coating agent. It is more preferable to use in the range which becomes 0.9-2.0 (molar ratio).

  Further, as the cationic group-containing polyol, for example, a tertiary amino group-containing polyol can be used. Specifically, N-methyl-diethanolamine, a compound having two epoxies in one molecule, and a secondary amine. A polyol obtained by reacting with can be used.

  It is preferable that a part or all of the cationic group is neutralized with an acidic compound such as formic acid, acetic acid, propionic acid, succinic acid, glutaric acid, tartaric acid and adipic acid.

  Further, the tertiary amino group as the cationic group is preferably partly or entirely quaternized. As the quaternizing agent, for example, dimethyl sulfate, diethyl sulfate, methyl chloride, ethyl chloride and the like can be used, and dimethyl sulfate is preferably used.

  Further, as the nonionic group-containing polyol, polyalkylene glycol having a structural unit derived from ethylene oxide can be used.

  The hydrophilic group-containing polyol (a3) is preferably used in the range of 0.1% by mass to 30% by mass with respect to the total amount of the polyol (A) used for the production of the urethane resin (C).

  As the polyol (A), in addition to the aliphatic cyclic structure-containing polyol (a1), the aromatic structure-containing polyester polyol (a2), and the hydrophilic group-containing polyol (a3), as necessary. Other polyols can be used in combination.

  As said other polyol, the polyester polyol, polyether polyol, polycarbonate polyol etc. which do not have an aliphatic cyclic structure, an aromatic structure, or a hydrophilic group can be used, for example.

  Moreover, as polyisocyanate (B) used for manufacture of the said urethane resin (C), aliphatic cyclic structure containing polyisocyanate (b1) is made essential, and another polyisocyanate is used in combination as needed.

  The aliphatic cyclic structure-containing polyisocyanate (b1) is used together with the aliphatic cyclic structure-containing polyol (a1) in the urethane resin (C) to give an aliphatic cyclic structure in the urethane resin (C). Use to do.

  As the aliphatic cyclic structure-containing polyisocyanate (b1), cyclohexane diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate and the like can be used. Among them, it is preferable to use dicyclohexylmethane diisocyanate or isophorone diisocyanate for forming a primer layer having excellent durability and flexibility as well as water resistance.

  Examples of the other polyisocyanates include aromatic polyisocyanates such as 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate, crude diphenylmethane diisocyanate, phenylene diisocyanate, tolylene diisocyanate, and naphthalene diisocyanate. Aliphatic polyisocyanates such as hexamethylene diisocyanate, lysine diisocyanate, xylylene diisocyanate, and tetramethylxylylene diisocyanate can be used.

  As the polyisocyanate (B), from the viewpoint of imparting excellent adhesion and water resistance, the aliphatic cyclic structure-containing polyisocyanate (b1) is added in an amount of 90 mass with respect to the total amount of the polyisocyanate (B). % Is preferably used in the range of 95% by mass or more and preferably in the range of 95% by mass to 100% by mass.

  The reaction between the polyol (A) and the polyisocyanate (B) is carried out, for example, in the absence of a solvent or in the presence of an organic solvent, the aliphatic cyclic structure-containing polyol (a1) and the aromatic structure-containing polyester polyol (a2). ) And the hydrophilic group-containing polyol (a3) and, if necessary, a polyol (A) containing the other polyol and the polyisocyanate (B) are mixed, and the reaction temperature is in the range of about 50 ° C to 150 ° C. It can be carried out.

  In the reaction of the polyol (A) and the polyisocyanate (B), for example, the equivalent ratio of the isocyanate group of the polyisocyanate (B) to the hydroxyl group of the polyol (A) is in the range of 0.8 to 2.5. Preferably, it is carried out in the range of 0.9 to 1.5.

  Moreover, when manufacturing the said urethane resin (C), in order to improve adhesiveness and water resistance further, and to improve chemical resistance and corrosion resistance, of the said polyol (A) and the said polyisocyanate (B) In addition, a chain extender can be used as needed.

  As a chain extender that can be used when the urethane resin (C) is produced, polyamine, other active hydrogen atom-containing compounds, and the like can be used.

  Examples of the polyamine include ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2,5-dimethylpiperazine, isophoronediamine, 4,4′-dicyclohexylmethanediamine, and 3,3′-. Diamines such as dimethyl-4,4′-dicyclohexylmethanediamine, 1,4-cyclohexanediamine; N-hydroxymethylaminoethylamine, N-hydroxyethylaminoethylamine, N-hydroxypropylaminopropylamine, N-ethylaminoethylamine, N-methylaminopropylamine; diethylenetriamine, dipropylenetriamine, triethylenetetramine; hydrazine, N, N′-dimethylhydrazine, 1,6-hexamethylenebishydrazine; Razide, adipic acid dihydrazide, glutaric acid dihydrazide, sebacic acid dihydrazide, isophthalic acid dihydrazide; β-semicarbazide propionic acid hydrazide, 3-semicarbazide-propyl-carbazate, semicarbazide-3-semicarbazide methyl-3,5 5-Trimethylcyclohexane can be used, and ethylenediamine is preferably used.

  Examples of the other active hydrogen-containing compounds include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, hexamethylene glycol, saccharose, Glycols such as methylene glycol, glycerin and sorbitol; phenols such as bisphenol A, 4,4′-dihydroxydiphenyl, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxydiphenyl sulfone, hydrogenated bisphenol A, hydroquinone, In addition, water and the like can be used alone or in combination of two or more within a range in which the storage stability of the coating agent of the present invention does not decrease.

  For example, when the polyamine is used, the chain extender is an isocyanate group of a urethane prepolymer obtained by reacting the amino group of the polyamine with the polyol (a1) and the polyisocyanate (a2). Is preferably used in a range of 1.9 or less (equivalent ratio), more preferably in a range of 0.3 to 1.0 (equivalent ratio). By using the chain extender in the above-described range, the solvent resistance and mechanical strength of the film to be formed can be improved.

  The chain extension reaction between the chain extender and the urethane prepolymer can be carried out, for example, by mixing the urethane prepolymer obtained by the above method or an aqueous dispersion thereof and a chain extender. The chain extension reaction may be performed before the step of neutralizing the hydrophilic group of the urethane prepolymer.

  The chain extender such as polyamine is used in a range where the urea bond equivalent of the urethane resin (C) is 500 to 50,000, and forms a film excellent in adhesion, water resistance, chemical resistance, and corrosion resistance. In addition, it is preferable.

  Moreover, when manufacturing the said urethane resin (C), in forming the film | membrane excellent in water resistance and solvent resistance, such as water-resistant adhesiveness and water-whitening resistance, the said polyol (A) and the said polyisocyanate ( In addition to B) and the chain extender, a hydrolyzable silyl group-containing amine (F) can be used as necessary.

  Examples of the hydrolyzable silyl group-containing amine (F) include γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropylmethyldiethoxysilane, N-β- (aminoethyl)- γ-aminopropylmethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-γ-trimethoxysilylpropyl-m-phenylenediamine, N, N-bis [3- (Trimethoxysilyl) propyl] ethylenediamine, N- (2-aminoethyl) -γ-aminopropylmethyldimethoxysilane, p- [N- (2-aminoethyl) aminomethyl] phenethyltrimethoxysilane, etc. may be used. it can.

  Among these, γ-aminopropyltriethoxysilane is preferably used for forming a film having a high crosslinking density and excellent water resistance.

  The hydrolyzable silyl group-containing amine (F) is 0.1% by mass to 15% by mass with respect to the total mass of the polyol (A) and polyisocyanate (B) used in the production of the urethane resin (C). It is preferable to use in the range.

  Examples of the organic solvent that can be used in producing the urethane resin (C) include ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran and dioxane; acetates such as ethyl acetate and butyl acetate; Nitriles: Amides such as dimethylformamide and N-methylpyrrolidone can be used alone or in combination of two or more. When the organic solvent is used when producing the urethane resin (C), from the viewpoint of reducing environmental burden, etc., during the production or after production of the urethane resin (C), if necessary, by a distillation method or the like. It is preferable to remove the organic solvent.

  For example, the urethane resin (C) obtained by the above method neutralizes part or all of the hydrophilic group of the urethane resin (C), and then mixes the neutralized product with the aqueous medium (D). By doing this, a urethane resin composition in which the urethane resin (C) is dissolved or dispersed in the aqueous medium (D) can be obtained. In the mixing, a machine such as a homogenizer may be used as necessary.

  Examples of the aqueous medium (D) include water, an organic solvent miscible with water, and a mixture thereof. Examples of the organic solvent miscible with water include alcohols such as methanol, ethanol, n- and isopropanol; ketones such as acetone and methyl ethyl ketone; polyalkylene glycols such as ethylene glycol, diethylene glycol and propylene glycol; Alkyl ethers; lactams such as N-methyl-2-pyrrolidone, and the like. In the present invention, only water may be used, a mixture of water and an organic solvent miscible with water may be used, or only an organic solvent miscible with water may be used. From the viewpoint of safety and load on the environment, water alone or a mixture of water and an organic solvent miscible with water is preferable, and only water is particularly preferable.

  The primer coating agent of the present invention suppresses a sudden increase in viscosity during production, and improves the productivity of the primer coating agent, ease of coating, drying properties, and the like. (D) is preferably included in the range of 40% by mass to 90% by mass, and more preferably in the range of 60% by mass to 80% by mass.

  In addition, the primer coating agent of the present invention, particularly when a hydrophilic topcoat layer is provided as a topcoat layer, is used to prevent the hydrophilic topcoat layer from peeling off or sinking into the primer layer. Polyol (G) containing aliphatic polyol (g1), aliphatic cyclic structure-containing polyol (g2), and hydrophilic group-containing polyol (g3) together with resin (C), and aliphatic cyclic structure-containing polyisocyanate The urethane resin (I) obtained by reacting the polyisocyanate (H) containing (h) can be used in combination.

  Examples of the aliphatic polyol (g1) used for the production of the urethane resin (I) include ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol and the like. be able to.

  As said aliphatic cyclic structure containing polyol (g2), the thing similar to what was illustrated as said aliphatic cyclic structure containing polyol (a2) can be used.

  As said hydrophilic group containing polyol (g3), the thing similar to what was illustrated as said hydrophilic group containing polyol (a3) can be used.

  The polyisocyanate (H) containing the aliphatic cyclic structure-containing polyisocyanate (h) is the same as that exemplified as the polyisocyanate (B) containing the aliphatic cyclic structure-containing polyisocyanate (b1). Can be used.

  The method for producing the urethane resin (I) by reacting the polyol (G) with the polyisocyanate (H) also reacts the polyol (A) with the polyisocyanate (B) to produce the urethane resin (C). It can manufacture by the method similar to the method illustrated as a manufacturing method.

  As the urethane resin (I), one having a weight average molecular weight in the range of 10,000 to 500,000 is preferably used.

  Moreover, when using the said urethane resin (I), as a primer coating agent of this invention, the mass ratio [(C) / (I)] of the said urethane resin (C) and the said urethane resin (I) Is preferably used in the range of 99/1 to 30/70 and used in the range of 90/10 to 70/30 to provide good adhesion to the substrate and the top coat layer. And more preferable.

  The primer coating agent of the present invention obtained by the method described above may contain, for example, a film forming aid, a filler, a thixotropic agent, a tackifier, a pigment, an antibacterial agent, etc. It can be used as long as the object of the invention is not impaired.

  The film forming aid is not particularly limited, and examples thereof include anionic surfactants (such as dioctyl sulfosuccinate soda salt), hydrophobic nonionic surfactants (such as sorbitan monooleate), and silicone oil. It is done.

  Examples of the filler include metal oxides such as silicon, aluminum, titanium, zirconium, zinc, and tin and their hydrolysis condensates, carbonates (for example, calcium salts, calcium / magnesium salts, magnesium salts, etc.), Silicic acid, silicate (eg aluminum salt, magnesium salt, calcium salt etc.), hydroxide (eg aluminum salt, magnesium salt, calcium salt etc.), sulfate (eg barium salt, calcium salt, magnesium salt etc.), borate (For example, aluminum salt, zinc salt, calcium salt, etc.), titanate (for example, potassium salt, etc.) and the like.

  Examples of the thixotropy-imparting agent include fatty acid, fatty acid metal salt, fatty acid ester, paraffin, resin acid, surfactant, polyacrylic acid and the like surface-treated filler, polyvinyl chloride powder, hydrogenated castor oil, Fine powder silica, organic bentonite, sepiolite and the like can be mentioned.

  Although it does not specifically limit as said tackifier, For example, tackifiers, such as a rosin resin type, a terpene resin type, a phenol resin type, are mentioned.

As the pigment, known and commonly used inorganic pigments and organic pigments can be used.
As the inorganic pigment, for example, titanium oxide, antimony red, bengara, cadmium red, cadmium yellow, cobalt blue, bitumen, ultramarine, carbon black, graphite and the like can be used.

  Examples of the organic pigment include quinacridone pigments, quinacridone quinone pigments, dioxazine pigments, phthalocyanine pigments, anthrapyrimidine pigments, ansanthrone pigments, indanthrone pigments, flavanthrone pigments, perylene pigments, Organic pigments such as diketopyrrolopyrrole pigments, perinone pigments, quinophthalone pigments, anthraquinone pigments, thioindigo pigments, benzimidazolone pigments, and azo pigments can be used. Two or more kinds of these pigments can be used in combination. These pigments may be surface-treated and have a self-dispersing ability with respect to an aqueous medium.

  As the antibacterial agent, for example, silver chloride, trifuranide, dichlorofluanide, fluorophorpet, zinc pyrithione, methyl 2-benzimidazole carbanate, 2- (4-thiazolyl) benzimidazole and the like can be used.

  Furthermore, other additives include, for example, reaction accelerators (metal-based, metal salt-based, amine-based, etc.), stabilizers (ultraviolet absorbers, antioxidants, heat-resistant stabilizers, etc.), moisture removal agents (4- And various additives such as adsorbents (quick lime, slaked lime, zeolite, molecular sieves, etc.), adhesion-imparting agents, antifoaming agents, and leveling agents.

  The primer coating agent of the present invention can be suitably used, for example, as a coating agent for forming a primer layer of a topcoat layer used for functional protection such as surface protection, designability, and solvent resistance of various substrates. it can.

  Examples of the substrate on which the primer coating agent can be applied to form a primer layer include a glass substrate, a metal substrate, a plastic substrate, paper, a wood substrate, and a fibrous substrate. Moreover, it can also be used for the base material of porous body structures, such as a urethane foam.

  Examples of plastic base materials include polycarbonate base materials, polyester base materials, acrylonitrile-butadiene-styrene base materials, polyacryl base materials, polystyrene base materials, polyurethane base materials, epoxy resin base materials, polyvinyl chloride base materials, and polyamide base materials. A base material etc. can be used.

  As said metal base material, galvanized steel plates, such as a galvanized steel plate and an aluminum zinc alloy steel plate, an iron plate, an aluminum plate, an aluminum alloy plate, an electromagnetic steel plate, a copper plate, a stainless steel plate etc. can be used, for example.

  The base material may be a planar material made of the above material or may have a curved portion, or may be a base material made of fibers such as a nonwoven fabric.

  The primer coating agent or the like of the present invention can form a film (primer layer) on its surface, for example, by directly applying it to the surface of the base material and then drying and curing.

  Examples of the method for applying the primer coating agent or the like on the substrate include a spray method, a curtain coater method, a flow coater method, a roll coater method, a brush coating method, and a dipping method.

  The method for drying and proceeding with curing may be a method of curing for about 1 to 10 days at room temperature, but from the viewpoint of rapidly proceeding curing, at a temperature of 50 to 250 ° C., 1 to A method of heating for about 600 seconds is preferable. Moreover, when using the plastic base material which is easy to deform | transform and discolor at comparatively high temperature, it is preferable to cure at comparatively low temperature of about 30 degreeC-100 degreeC.

  Although the film thickness of the primer layer formed using the primer coating agent of this invention can be suitably adjusted according to the use etc. which a base material is used for, it is preferable that it is normally about 0.5 micrometer-20 micrometers.

  Moreover, it is preferable that the laminated body which has the primer layer formed using the primer coating agent of this invention on the said base material has a topcoat layer further on the said primer layer. If it is a primer layer formed using the primer coating agent of the present invention, it is possible to improve the adhesion between the base material and the top coat layer and to prevent the decrease in adhesion and whitening due to the influence of water. Is possible.

  As the top coat layer, for example, a top coat layer having high hydrophilic performance can be used although it varies depending on the use of the obtained laminate.

  As the coating agent capable of forming the highly hydrophilic topcoat layer, for example, an acrylic resin, an acrylamide resin, a polyethylene glycol resin, a cellulose resin, or the like can be used. Among them, an acrylic resin is preferable, and an acrylic resin having a hydrophilic group such as a carboxyl group is preferable because a highly hydrophilic topcoat layer can be formed.

  In addition, the hydrophilic topcoat layer may contain a water-soluble resin from the viewpoint of imparting better hydrophilicity and improving surface slippage during processing.

Examples of the water-soluble resin include polyvinyl alcohol resins that are resins having a hydroxy group as a hydrophilic structural unit [polyvinyl alcohol (PVA), acetoacetyl-modified polyvinyl alcohol, cation-modified polyvinyl alcohol, anion-modified polyvinyl alcohol, silanol-modified. Polyvinyl alcohol, polyvinyl acetal, etc.], cellulosic resins [methyl cellulose (MC), ethyl cellulose (EC), hydroxyethyl cellulose (HEC), carboxymethyl cellulose (CMC), hydroxypropyl cellulose (HPC), hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose, etc.] , Chitins, chitosans, starch, resins with ether linkages [polyethylene oxide (PEO), Propylene oxide (PPO), polyethylene glycol (PEG), poly ether (PVE)], and resins having carbamoyl groups [polyacrylamide (PAAM), polyvinyl pyrrolidone (PVP), polyacrylic acid hydrazide, etc.] and the like. In addition, polyacrylic acid salts having a carboxyl group as a dissociable group, maleic acid resin, alginate, gelatins and the like can also be mentioned. The topcoat layer forms the primer layer on the substrate surface, and then the It can be formed by applying the coating agent for forming the topcoat layer on the primer coat layer and drying it.

  The top coat layer is preferably in the range of 0.5 μm to 2 μm from the viewpoint of maintaining high hydrophilic performance over a long period of time.

  As described above, the laminate having the primer layer on the base material and having the top coat layer provided on the primer layer can peel the top coat layer over a long period of time regardless of the influence of water or the like. For example, heat exchangers such as air conditioners and refrigerators, antireflection films that require antifouling properties and antifogging properties, optical filters, optical lenses, spectacle lenses, mirrors, and other optical members are used. It can be used for home appliances, displays, automobile interior materials, exterior materials, building materials such as wall materials and roof materials.

  Hereinafter, the present invention will be specifically described by way of examples and comparative examples.

[Example 1]
Aromatic structure-containing polyester polyol obtained by reacting ethylene glycol, 1,4-butanediol, isophthalic acid and terephthalic acid in a nitrogen-substituted container equipped with a thermometer, a nitrogen gas introduction tube and a stirrer ( Hydroxyl group equivalent 840 g / equivalent] 64 parts by mass, 1,4-cyclohexanedimethanol 6 parts by mass, 2,2-dimethylolpropionic acid 7 parts by mass, and dicyclohexylmethane diisocyanate 47 parts by mass were mixed with 80 parts by mass of methyl ethyl ketone, By making it react on the conditions of the temperature of 80 degreeC in the said reaction container, the organic solvent solution of the urethane prepolymer which has an isocyanate group in the molecule terminal was obtained.

  Next, after neutralizing part or all of the carboxyl groups of the urethane resin by mixing the organic solvent solution of the urethane prepolymer and 5 parts by mass of triethylamine, 264 parts by mass of water was further added and sufficiently stirred. Then, 7 parts by mass of a 20% by mass aqueous ethylenediamine solution was added to cause chain elongation reaction, and further distilled under reduced pressure, whereby water dispersion of urethane resin (C-1) having a non-volatile content of 35% by mass and a pH of 8.0. Primer coating agent (I) consisting of body was obtained.

[Example 2]
Aromatic structure-containing polyester polyol (hydroxyl group) obtained by reacting ethylene glycol, 1,4-butanediol, isophthalic acid and terephthalic acid in a nitrogen-substituted container equipped with a thermometer, a nitrogen gas introduction tube and a stirrer Equivalent 840 g / equivalent] 64 parts by mass, 1,4-cyclohexanedimethanol 6 parts by mass, 2,2-dimethylolpropionic acid 7 parts by mass, and dicyclohexylmethane diisocyanate 47 parts by mass are mixed with methyl ethyl ketone 100 parts by mass and reacted. By doing so, an organic solvent solution of a urethane prepolymer having an isocyanate group at the molecular end was obtained.

  Next, an organic solvent solution of the urethane prepolymer and 5 parts by mass of 3-aminopropyltriethoxysilane are mixed, and the urethane prepolymer and 3-aminopropyltriethoxysilane are reacted to produce an ethoxysilyl group. And the organic solvent solution of the urethane resin (C'-2) which has any one or both of a silanol group, and a hydrophilic group was obtained.

  Next, by adding 5 parts by mass of triethylamine to the organic solvent solution of the urethane resin (C′-2) having the hydrophilic group, part or all of the carboxyl groups of the urethane resin (C′-2). Then, 278 parts by mass of water was further added and sufficiently stirred, and 7 parts by mass of a 20% by mass aqueous ethylenediamine solution was added to cause chain extension reaction, followed by distillation under reduced pressure to obtain a non-volatile content of 35% by mass. The primer coating agent (II) which consists of an aqueous dispersion of the urethane resin (C-2) whose is is 8.1 was obtained.

[Example 3]
Aromatic structure-containing polyester polyol (hydroxyl group) obtained by reacting ethylene glycol, 1,4-butanediol, isophthalic acid and terephthalic acid in a nitrogen-substituted container equipped with a thermometer, a nitrogen gas introduction tube and a stirrer Equivalent 840 g / equivalent] 74 parts by mass, 6 parts by mass of 1,4-cyclohexanedimethanol, 7 parts by mass of 2,2-dimethylolpropionic acid, and 37 parts by mass of dicyclohexylmethane diisocyanate were mixed with 80 parts by mass of methyl ethyl ketone, An organic solvent solution of urethane resin (C′-3) having an isocyanate group at the molecular end was obtained by reacting under a condition of a temperature of 80 ° C. in the reaction vessel.

  After the solution viscosity became constant, the temperature was lowered to 60 ° C., 0.2 parts by mass of methanol was added, and further reacted to obtain an organic solvent solution of urethane resin (C′-3) having a hydrophilic group. .

  Next, a part or all of the carboxyl groups of the urethane resin (C′-3) are mixed by mixing an organic solvent solution of the urethane resin (C′-3) and 18 parts by mass of 5% by mass ammonia water. After neutralization, 490 parts by mass of water was further added, and the mixture was sufficiently stirred and further distilled under reduced pressure, whereby an aqueous dispersion of urethane resin (C-3) having a nonvolatile content of 25% by mass and a pH of 7.9. Primer coating agent (III) consisting of

[Example 4]
Aromatic structure-containing polyester polyol (hydroxyl group) obtained by reacting ethylene glycol, 1,4-butanediol, isophthalic acid and terephthalic acid in a nitrogen-substituted container equipped with a thermometer, a nitrogen gas introduction tube and a stirrer Equivalent 840 g / equivalent] 26 parts by mass, 26 parts by mass of 1,4-cyclohexanedimethanol, 7 parts by mass of 2,2-dimethylolpropionic acid, and 65 parts by mass of dicyclohexylmethane diisocyanate were mixed with 80 parts by mass of methyl ethyl ketone, An organic solvent solution of a urethane resin (C′-4) having an isocyanate group at the molecular end was obtained by reacting under a temperature of 80 ° C. in a reaction vessel.

  After the solution viscosity became constant, the temperature was lowered to 60 ° C., 0.2 parts by mass of methanol was added, and further reacted to obtain an organic solvent solution of urethane resin (C′-4) having a hydrophilic group. .

  Next, by mixing an organic solvent solution of the urethane resin (C′-4) and 18 parts by mass of 5 mass% ammonia water, part or all of the carboxyl groups of the urethane resin (C′-4) are mixed. After neutralization, 490 parts by mass of water was further added, and the mixture was sufficiently stirred and further distilled under reduced pressure, whereby an aqueous dispersion of urethane resin (C-4) having a nonvolatile content of 25% by mass and a pH of 7.5. Primer coating agent (IV) consisting of

[Example 5]
Aliphatic cyclic structure-containing polycarbonate diol [500 g of hydroxyl group equivalent] obtained by reacting 1,6-cyclohexanedimethanol and carbonate in a nitrogen-substituted container equipped with a thermometer, a nitrogen gas introduction tube and a stirrer / Equivalent] 46 parts by mass, an aromatic structure-containing polyester polyol obtained by reacting ethylene glycol, 1,4-butanediol, isophthalic acid and terephthalic acid (hydroxyl equivalent 840 g / equivalent) 31 parts by mass, 2,2-di By mixing 7 parts by mass of methylolpropionic acid and 41 parts by mass of dicyclohexylmethane diisocyanate with 80 parts by mass of methyl ethyl ketone and reacting them at a temperature of 80 ° C. in the reaction vessel, a urethane prepolymer having an isocyanate group at the molecular terminal is obtained. An organic solvent solution of the polymer was obtained.

  Next, after neutralizing part or all of the carboxyl groups of the urethane resin by mixing the organic solvent solution of the urethane prepolymer and 5 parts by mass of triethylamine, 277 parts by mass of water was further added and sufficiently stirred. Then, 6 parts by mass of a 20% by mass aqueous ethylenediamine solution was added to cause chain extension reaction, and further distilled under reduced pressure, whereby water dispersion of a urethane resin (C-5) having a non-volatile content of 35% by mass and a pH of 8.0. A primer coating agent (V) comprising a body was obtained.

[Comparative Example 1]
Aromatic structure-containing polyester polyol obtained by reacting ethylene glycol, 1,4-butanediol, isophthalic acid and terephthalic acid in a nitrogen-substituted container equipped with a thermometer, a nitrogen gas introduction tube and a stirrer ( Hydroxyl group equivalent 840 g / equivalent] 82 parts by mass, 2,2-dimethylolpropionic acid 7 parts by mass, and dicyclohexylmethane diisocyanate 35 parts by mass were mixed with 80 parts by mass of methyl ethyl ketone, and the temperature in the reaction vessel was 80 ° C. To obtain an organic solvent solution of a urethane prepolymer having an isocyanate group at the molecular end.

  Next, after neutralizing part or all of the carboxyl groups of the urethane resin by mixing the organic solvent solution of the urethane prepolymer and 5 parts by mass of triethylamine, 264 parts by mass of water was further added and sufficiently stirred. Then, 5 parts by mass of a 20% by mass ethylenediamine aqueous solution was added to cause chain elongation reaction, and further distilled under reduced pressure, whereby water dispersion of urethane resin (C-6) having a non-volatile content of 35% by mass and a pH of 8.2. A primer coating agent (VI) comprising a body was obtained.

[Comparative Example 2]
In a nitrogen-substituted container equipped with a thermometer, a nitrogen gas inlet tube, and a stirrer, “PTMG-2000” [manufactured by Mitsubishi Chemical Corporation, polytetramethylene glycol, hydroxyl group equivalent 1000 g / equivalent] 66 parts by mass, 1, By reacting 6 parts by mass of 4-cyclohexanedimethanol, 7 parts by mass of 2,2-dimethylolpropionic acid, and 45 parts by mass of dicyclohexylmethane diisocyanate in 100 parts by mass of methyl ethyl ketone at 80 ° C., the molecular terminal has an isocyanate group. An organic solvent solution of urethane prepolymer was obtained.

  Next, after neutralizing a part or all of the carboxyl groups of the urethane resin by mixing the organic solvent solution of the urethane prepolymer and 5 parts by mass of triethylamine, 278 parts by mass of water was further added and sufficiently stirred. Then, 7 parts by mass of a 20% by mass ethylenediamine aqueous solution was added to cause chain elongation reaction, and further distilled under reduced pressure, whereby water dispersion of urethane resin (C-7) having a non-volatile content of 35% by mass and a pH of 8.1 Primer coating agent (VII) consisting of body was obtained.

[Comparative Example 3]
Aliphatic polyester polyol obtained by reacting neopentyl glycol, 1,6-hexanediol and adipic acid in a nitrogen-substituted container equipped with a thermometer, a nitrogen gas introduction tube and a stirrer (hydroxyl equivalent: 1000 g / Equivalent] By reacting 66 parts by mass, 6 parts by mass of 1,4-cyclohexanedimethanol, 7 parts by mass of 2,2-dimethylolpropionic acid, and 45 parts by mass of dicyclohexylmethane diisocyanate at 80 ° C. in 100 parts by mass of methyl ethyl ketone. An organic solvent solution of a urethane prepolymer having an isocyanate group at the molecular end was obtained.

  Next, after neutralizing a part or all of the carboxyl groups of the urethane resin by mixing the organic solvent solution of the urethane prepolymer and 5 parts by mass of triethylamine, 278 parts by mass of water was further added and sufficiently stirred. Then, 7 parts by mass of a 20% by mass aqueous ethylenediamine solution was added to cause chain extension reaction, and further distilled under reduced pressure, whereby water dispersion of urethane resin (C-8) having a non-volatile content of 35% by mass and a pH of 8.1. A primer coating agent (VIII) comprising a body was obtained.

[Comparative Example 4]
Aromatic structure-containing polyester polyol obtained by reacting ethylene glycol, 1,4-butanediol, isophthalic acid and terephthalic acid in a nitrogen-substituted container equipped with a thermometer, a nitrogen gas introduction tube and a stirrer ( Hydroxyl group equivalent 840 g / equivalent] 62 parts by mass, 1,4-cyclohexanedimethanol 6 parts by mass, 2,2-dimethylolpropionic acid 7 parts by mass, 4,4'-diphenylmethane diisocyanate 49 parts by mass, methyl ethyl ketone 80 parts by mass And an organic solvent solution of a urethane prepolymer having an isocyanate group at the molecular end was obtained by reacting under the conditions of a temperature of 80 ° C. in the reaction vessel.

  Next, after neutralizing part or all of the carboxyl groups of the urethane resin by mixing the organic solvent solution of the urethane prepolymer and 5 parts by mass of triethylamine, 264 parts by mass of water was further added and sufficiently stirred. Then, 7 parts by mass of a 20% by mass aqueous ethylenediamine solution was added to cause chain elongation reaction, and further distilled under reduced pressure, whereby water dispersion of urethane resin (C-9) having a non-volatile content of 35% by mass and a pH of 8.1 Primer coating agent (IX) consisting of body was obtained.

[Comparative Example 5]
Aromatic structure-containing polyester polyol obtained by reacting ethylene glycol, 1,4-butanediol, isophthalic acid and terephthalic acid in a nitrogen-substituted container equipped with a thermometer, a nitrogen gas introduction tube and a stirrer ( Hydroxyl group equivalent 840 g / equivalent] 57 parts by mass, 1,4-butanediol 6 parts by mass, 2,2-dimethylolpropionic acid 7 parts by mass, and dicyclohexylmethane diisocyanate 54 parts by mass were mixed with 80 parts by mass of methyl ethyl ketone, An organic solvent solution of a urethane prepolymer having an isocyanate group at the molecular end was obtained by reacting under a condition of a temperature of 80 ° C. in the reaction vessel.

  Next, after neutralizing part or all of the carboxyl groups of the urethane resin by mixing the organic solvent solution of the urethane prepolymer and 5 parts by mass of triethylamine, 264 parts by mass of water was further added and sufficiently stirred. Then, 8 parts by mass of a 20% by mass aqueous ethylenediamine solution was added to cause chain extension reaction, and further distilled under reduced pressure, whereby water dispersion of a urethane resin (C-10) having a non-volatile content of 35% by mass and a pH of 8.2. Primer coating agent (X) consisting of body was obtained.

[Comparative Example 6]
Aromatic structure-containing polyester polyol obtained by reacting ethylene glycol, 1,4-butanediol, isophthalic acid and terephthalic acid in a nitrogen-substituted container equipped with a thermometer, a nitrogen gas introduction tube and a stirrer ( Hydroxyl group equivalent 840 g / equivalent] 134 parts by mass, 1,4-cyclohexanedimethanol 14 parts by mass, 2,2-dimethylolpropionic acid 7 parts by mass, and dicyclohexylmethane diisocyanate 74 parts by mass were mixed with methyl ethyl ketone 120 parts by mass, By making it react on the conditions of the temperature of 80 degreeC in the said reaction container, the organic solvent solution of the urethane prepolymer which has an isocyanate group in the molecule terminal was obtained.

  Next, after neutralizing part or all of the carboxyl groups of the urethane resin by mixing the organic solvent solution of the urethane prepolymer and 5 parts by mass of triethylamine, 419 parts by mass of water was further added and sufficiently stirred. Then, 11 parts by mass of a 20% by mass ethylenediamine aqueous solution was added to cause chain elongation reaction, and further distilled under reduced pressure, whereby water dispersion of urethane resin (C-11) having a nonvolatile content of 35% by mass and a pH of 7.7 Primer coating agent (XI) consisting of body was obtained.

[Comparative Example 7]
Aromatic structure-containing polyester polyol obtained by reacting ethylene glycol, 1,4-butanediol, isophthalic acid and terephthalic acid in a nitrogen-substituted container equipped with a thermometer, a nitrogen gas introduction tube and a stirrer ( Hydroxyl group equivalent 840 g / equivalent] 49 parts by mass, 1,4-cyclohexanedimethanol 0.3 part by mass, 2,2-dimethylolpropionic acid 7 parts by mass, and dicyclohexylmethane diisocyanate 27 parts by mass were mixed with methyl ethyl ketone 47 parts by mass. And the organic solvent solution of the urethane prepolymer which has an isocyanate group in the molecular terminal was obtained by making it react on the conditions of the temperature of 80 degreeC in the said reaction container.

  Next, after neutralizing part or all of the carboxyl groups of the urethane resin by mixing the organic solvent solution of the urethane prepolymer and 5 parts by mass of triethylamine, 148 parts by mass of water was further added and sufficiently stirred. Then, 4 parts by mass of a 20% by mass ethylenediamine aqueous solution was added to cause chain elongation reaction, and further distilled under reduced pressure, whereby water dispersion of urethane resin (C-12) having a non-volatile content of 32% by mass and a pH of 8.4. Primer coating agent (XII) consisting of body was obtained.

[Adhesion evaluation method]
(Evaluation method for adhesion between substrate and primer layer)
The primer coat agent was applied to the surfaces of eight types of substrates shown in the following [1] to [8] using a bar coater so that the film thickness was 2 μm, and a hot air dryer was used. Was dried at 80 ° C. for 30 seconds and then dried at 23 ° C. for 24 hours to obtain 8 types of test plates 1 in which a film composed of a primer layer was laminated on the surface of each substrate.

〔Base material〕
All base materials are purchased from Engineering Test Service.

[1] PET: Polyethylene terephthalate, 1.0 mm x 70 mm x 150 mm
[2] PC: Polycarbonate, 1.0 mm x 70 mm x 150 mm
[3] PVC: Vinyl chloride, 2.0 mm x 70 mm x 150 mm
[4] SUS: JIS G4305 SUS304, 0.5 mm x 70 mm x 150 mm
[5] SPC: JIS G3141 SPCC-SB, 0.8 mm x 70 mm x 150 mm
[6] Aluminum: JIS H4000 A1050P, 0.8 mm x 70 mm x 150 mm
[7] Glass: JIS R3202, 2.0 mm x 70 mm x 150 mm
[8] GL: Hot-dip galvanized steel sheet (45% by mass of zinc, 55% by mass of aluminum), 0.8 mm × 70 mm × 150 mm
The adhesion between the primer layer (coating) constituting the test plate 1 obtained above and the substrate was measured based on the JIS K5600 cross cut test method and evaluated according to the following evaluation criteria.

A: No peeling of the film was observed.
○: The area where the film was peeled off was less than 3% of the total grid area.
Δ: The area where the film was peeled was 3% or more and less than 50% of the total grid area.
X: The area where the film was peeled off was 50% or more of the total grid area.

(Evaluation method for adhesion between topcoat layer and primer layer)
The primer coating agent was applied to the surface of the above [6] aluminum substrate (JIS H4000 A1050P, 0.8 × 70 × 150 mm) using a bar coater so that the film thickness was 2 μm, After drying at 80 ° C. for 30 seconds using a hot air dryer, drying was performed at 23 ° C. for 24 hours, thereby forming a primer layer on the surface of the aluminum substrate.

Next, a hydrophilic topcoat agent containing polyethylene glycol and an acrylic resin obtained by copolymerizing (meth) acrylic acid, acrylamide and N-methylolacrylamide on the primer layer described above, and the film thickness of the film Was applied under the condition of 2 μm, and then dried at 250 ° C. for 5 seconds to obtain a laminate 1 having a hydrophilic topcoat layer on the primer layer.
On the other hand, the primer coating agent was applied to the surface of the transparent film made of [1] PET (polyethylene terephthalate, 1.0 mm × 70 mm × 150 mm) using a bar coater so that the film thickness was 2 μm. And then dried at 80 ° C. for 30 seconds using a hot air dryer, and then dried at 23 ° C. for 24 hours to form a primer layer on the surface of the transparent film.

Next, a hydrophilic topcoat agent containing polyethylene glycol and an acrylic resin obtained by copolymerizing (meth) acrylic acid, acrylamide and N-methylolacrylamide on the primer layer described above, and the film thickness of the film Was applied under the condition of 2 μm, and then dried at 80 ° C. for 30 seconds to obtain a laminate 2 having a hydrophilic topcoat layer on the primer layer.
In order to evaluate the adhesion between the top coat layer and the primer layer constituting the laminates 1 and 2, a friction piece (2 cm long × 2 cm wide) of a Gakushin type friction tester (manufactured by Daiei Kagaku Seiki Seisakusho). A cotton cloth (Kanakin No. 3) impregnated with 0.1 ml of water was attached, and the surface of the top coat layer of the laminates 1 and 2 was rubbed 50 times in a range of 10 cm long × 2 cm wide with a load of 200 g. The number of rubbing was set to once when the same location on the surface of the hydrophilic topcoat layer was reciprocated once using a cotton cloth. In the table, “*” indicates that peeling occurred between the primer layer and the base material and the adhesion between the topcoat layer and the primer layer could not be evaluated.

A: The top coat layer was not peeled off at all.
A: The area where the topcoat layer was peeled off was less than 3% of the total scratched area.
Δ: The area where the top coat layer was peeled was 3% or more and less than 50% of the total scratched area.
X: The area where the topcoat layer was peeled was 50% or more of the total scratched area.

[Evaluation method of water resistance]
(Evaluation method for water-resistant adhesion)
The primer coat agent was applied to the surface of the above [6] aluminum substrate (JIS H4000 A1050P, 0.8 × 70 × 150 mm) using a bar coater so that the film thickness was 2 μm. Then, after drying at 80 ° C. for 30 seconds using a hot air dryer, drying was performed at 23 ° C. for 24 hours to obtain a test plate 2 in which a film made of a primer layer was laminated on the surface of the aluminum substrate.
On the other hand, the primer coat agent was applied to the surface of the transparent film made of [1] PET (polyethylene terephthalate, 1.0 mm × 70 mm × 150 mm) using a bar coater so that the film thickness of the film was 2 μm. After coating and drying at 80 ° C. for 30 seconds using a hot air dryer, drying is performed at 23 ° C. for 24 hours to obtain a test plate 3 in which a film made of a primer layer is laminated on the surface of the transparent film. It was.

  The test plates 2 and 3 are immersed in warm water of 40 ° C. for 24 hours, wiped off the water on the surface, and then the primer layer (film) constituting the test plates 2 and 3 after immersion and the base material, respectively. The adhesion was measured based on the JIS K5600 cross cut test method and evaluated according to the following evaluation criteria.

A: No peeling of the film was observed.
○: The area where the film was peeled off was less than 3% of the total grid area.
Δ: The area where the film was peeled was 3% or more and less than 50% of the total grid area.
X: The area where the film was peeled off was 50% or more of the total grid area.

(Evaluation method for water whitening resistance)
The primer coat agent was applied to the surface of the transparent film made of [1] PET (polyethylene terephthalate, 1.0 mm × 70 mm × 150 mm) using a bar coater so that the film thickness was 2 μm. Then, after drying at 80 ° C. for 30 seconds using a hot air dryer, drying was performed at 23 ° C. for 24 hours to obtain a test plate 4 in which a primer layer (film) was laminated on the surface of the transparent film.

  The test plate 4 is immersed in warm water at 40 ° C. for 24 hours, and the surface water is wiped off. Then, the primer layer constituting the test plate 4 is visually observed for the presence of turbidity and evaluated according to the following evaluation criteria. did.

(Double-circle): There was no change with the external appearance of the test board 4 before immersion, and whitening was not recognized.
○: Slight whitening was confirmed in a very small part, but it was at a level where there was no practical problem.
Δ: Slight whitening was observed throughout the test plate 4.
X: Remarkable whitening was recognized over the whole test plate 4.

[Evaluation method of solvent resistance]
The primer coat agent was applied to the surface of the above [6] aluminum substrate (JIS H4000 A1050P, 0.8 × 70 × 150 mm) using a bar coater so that the film thickness was 2 μm. Then, after drying at 80 ° C. for 30 seconds using a hot air dryer, drying was performed at 23 ° C. for 24 hours to obtain a test plate 5 in which a film made of a primer layer was laminated on the surface of each substrate.
On the other hand, the primer coat agent was applied to the surface of the transparent film made of [1] PET (polyethylene terephthalate, 1.0 mm × 70 mm × 150 mm) using a bar coater so that the film thickness of the film was 2 μm. After coating and drying at 80 ° C. for 30 seconds using a hot air dryer, drying was performed at 23 ° C. for 24 hours to obtain a test plate 6 in which a film made of a primer layer was laminated on the surface of each substrate.
Gauze impregnated with methyl ethyl ketone is brought into contact with the primer layer (coating) surfaces of the test plates 5 and 6, and using a rubbing tester (manufactured by Kayaku Giken Kogyo Co., Ltd.), the load is 0.5 kgf / cm ² The surface of the primer layer (film) was rubbed back and forth 50 times.

The surface of the film after rubbing was visually observed and evaluated based on the following criteria.
A: There is no change on the surface of the film.
○: Although some dissolution of the film was observed, it was at a level where there was no practical problem.
Δ: Dissolution or desorption from the substrate was observed in the range of 10% or more and less than 30% with respect to the entire coating surface.
X: Dissolution or desorption from the substrate was observed in a range of 30% or more with respect to the entire coating surface.

  In addition, instead of using gauze impregnated with methyl ethyl ketone, the surface of the primer layer is rubbed in the same manner as described above except that gauze impregnated with ethanol is used, and the surface state after rubbing is visually observed, Evaluation was based on criteria.

[Alkali resistance evaluation method]
The primer coat agent was applied to the surface of the above [6] aluminum substrate (JIS H4000 A1050P, 0.8 × 70 × 150 mm) using a bar coater so that the film thickness was 2 μm. Then, after drying at 80 ° C. for 30 seconds using a hot air dryer, drying was performed at 23 ° C. for 24 hours to obtain a test plate 7 in which a film made of a primer layer was laminated on the surface of each substrate.

  One drop of a 5% by mass aqueous sodium hydroxide solution was dropped on the surface of the primer layer (coating) of the test plate 7, and the deterioration state of the coating film after standing for 20 minutes was observed.

A: There was no change on the surface of the film.
A: Some discoloration was observed on a part of the surface of the film, but it was at a level where there was no practical problem.
Δ: Discoloration was observed on the surface of the film.
X: The film was dissolved and the substrate was exposed.

  The description of “aliphatic cyclic structure ratio 1” in Tables 1 and 2 indicates the mass ratio of the aliphatic cyclic structure contained in the total amount of the urethane resin (C). Moreover, "aliphatic cyclic structure ratio 2" in Tables 1 and 2 is the mass ratio of the aliphatic cyclic structure derived from the aliphatic cyclic structure-containing polyol (a1) contained in the total amount of the urethane resin (C). Indicates.

Claims (12)

Polyol (A) containing aliphatic cyclic structure-containing polyol (a1), aromatic structure-containing polyester polyol (a2) and hydrophilic group-containing polyol (a3), and aliphatic cyclic structure-containing polyisocyanate (b1) A primer coating agent characterized by containing a urethane resin (C) having an acid value of 16 to 40 obtained by reacting a polyisocyanate (B) containing an aqueous medium (D). The ratio of the aliphatic cyclic structure derived from the aliphatic cyclic structure-containing polyol (a1) to the total amount of the urethane resin (C) is in the range of 0.1% by mass to 35% by mass. Primer coating agent. The primer coating agent according to claim 1, wherein the aliphatic cyclic structure-containing polyol (a1) has a molecular weight of 100 to 500. The primer coating agent of Claim 1 whose ratio of the aromatic structure derived from the said aromatic structure containing polyester polyol (a2) with respect to the whole quantity of the said urethane resin (C) is the range of 5 mass%-30 mass%. The primer coating agent according to claim 1, wherein the aromatic structure-containing polyester polyol (a2) has a number average molecular weight of 500 to 5,000 obtained by reacting an aliphatic polyol and an aromatic polycarboxylic acid. The urethane resin (C) is obtained by reacting the urethane prepolymer obtained by reacting the polyol (A) and the polyisocyanate (B), and the chain extender (E). The primer coating agent according to claim 1, wherein The urethane resin (C) is a urethane prepolymer, a chain extender (E), and a hydrolyzable silyl group-containing amine (F) obtained by reacting the polyol (A) and the polyisocyanate (B). The primer coating agent according to claim 1, which is obtained by reacting. The primer coating agent of Claim 6 whose urea bond equivalent of the said urethane resin (C) is the range of 500-50000. A laminate having a primer layer formed by applying and drying the primer coating agent according to any one of claims 1 to 8 on the surface of the base material, and having a top coat layer on the surface of the primer layer body. The laminate according to claim 9, wherein the top coat layer is formed using a coating agent containing a hydrophilic acrylic resin. The laminate according to claim 9, wherein the top coat layer is formed using a coating agent containing a water-soluble resin and a hydrophilic acrylic resin. The laminate according to claim 9, wherein the substrate is a metal substrate or a plastic substrate.