JP6946314B2 - Water-based polyurethane resin composition - Google Patents

Description

The present invention relates to an aqueous polyurethane resin composition useful as a material for an easy-adhesion layer between a polyester resin layer and a photocurable resin layer.

In the backlight unit of the liquid crystal display, a prism sheet is used to improve the brightness. A prism pattern is formed on the surface of the prism sheet in order to collect the light emitted from the light guide in the direction of the liquid crystal panel. The prism sheet is usually composed of a photocurable resin on which a prism pattern is formed and a polyester resin film such as polyethylene terephthalate (PET) resin, and is a photocurable polyester resin film coated with an easy-adhesion layer and having a prism pattern. Manufactured by adhering and adhering based resins. Since the prism sheet is required to have transparency, heat resistance to maintain its performance at high temperatures such as summer, and transparency under high humidity conditions, the easy-adhesion layer of the prism sheet also has the same performance. There is a need. Further, the easy-adhesion layer is required to have adhesiveness to a photocurable resin and a polyester resin and blocking resistance. Polyurethane resin is used for the easy-adhesion layer, but in recent years, water-based polyurethane resin (see, for example, Patent Documents 1 and 2) has been studied from the viewpoint of safety such as environmental pollution and occupational health.

Japanese Unexamined Patent Publication No. 2011-140139 WO2013 / 014837A1

However, the water-based polyurethane resin has a drawback that the adhesion to the polyester resin is inferior to that of the solvent-based or solvent-free polyurethane resin. Therefore, when the water-based polyurethane resin is used, the adhesive surface is treated with corona. , It was necessary to use a polyester resin film whose surface was modified by plasma treatment, glow discharge treatment, or the like. Further, since the water-based polyurethane resin may be exposed to high temperature such as storage and transportation in high temperature in summer, it is necessary to have excellent storage stability. Therefore, the subject of the present invention is polyester. It is an object of the present invention to provide an aqueous polyurethane resin having excellent adhesion to a resin and blocking resistance, and further to provide an aqueous polyurethane resin having excellent transparency. Another object of the present invention is to provide an aqueous polyurethane resin having excellent storage stability.

As a result of diligent studies to solve the above problems, the present inventors apply an aqueous polyurethane resin having a specific amount of blocked isocyanate groups and heat-cure the resin to easily adhere to the polyester resin. We have found that a layer can be obtained and completed the present invention.
That is, the present invention contains, as the component (A), a urethane prepolymer which is a reaction product of a polyol compound, a polyisocyanate compound and an anionic group introducer, and as a component (B), a blocked polyisocyanate compound, and blocks. The present invention provides an aqueous polyurethane resin composition characterized in that the content of the diisocyanate group is 0.5 to 4 mmol / g with respect to the solid content.

The present invention also provides an adhesive for a polyester resin film made of the water-based polyurethane resin composition and an adhesive for an optical film made of the water-based polyurethane resin composition.
Further, the present invention relates to a step of reacting a polyol compound, a polyisocyanate compound and an anionic group-introducing agent to produce a urethane prepolymer, a urethane prepolymer, and a non-self-emulsifying blocked poly as the blocked polyisocyanate compound. The present invention provides a method for producing an aqueous polyurethane resin composition, which comprises a step of mixing an isocyanate compound to form a mixture and a step of dispersing the mixture in water.
Further, in the present invention, the step of applying the above-mentioned aqueous polyurethane resin composition to the base film, the step of drying the applied aqueous polyurethane resin composition, and the step of thermosetting the dried aqueous polyurethane resin composition at 150 to 250 ° C. It provides a method of manufacturing an optical film having a process.

[(A) component]
The component (A) in the water-based polyurethane resin composition of the present invention is a urethane prepolymer. This urethane prepolymer is a reaction product of a polyol compound, a polyisocyanate compound, and an anionic group-introducing agent. The urethane prepolymer as the component (A) is a polymer compound having a relatively low molecular weight, which is obtained by reacting a hydroxyl group of a polyol compound, an isocyanate group of a polyisocyanate compound, and an anionic group introducing agent.

The urethane prepolymer is a reaction product of a polyol compound, a polyisocyanate compound, and an anionic group-introducing agent. In the present invention, a wide variety of compounds can be used as the polyol compound, the polyisocyanate compound and the anionic group introducing agent, as will be described later. Therefore, the structure of the urethane prepolymer differs greatly depending on the structure of the raw material used for producing the urethane prepolymer. Therefore, it is impossible to uniformly express the structure of the urethane prepolymer by a certain general formula, which is a common general technical knowledge of those skilled in the art. And, if the structure is not specified, the characteristics of the substance determined accordingly cannot be easily understood, so that it cannot be expressed by the characteristics. Therefore, in the present invention, the urethane prepolymer contained in the aqueous polyurethane resin composition must be defined by the expression "urethane prepolymer which is a reaction product of a polyol compound, a polyisocyanate compound and an anionic group introducer". No. That is, with respect to the urethane prepolymer used in the present invention, there are circumstances in which it is impossible or approximately impractical to "directly specify the urethane prepolymer by its structure or properties at the time of filing."

Further, in the present invention, the urethane prepolymer may be a reaction product of four components of a polyol compound, a polyisocyanate compound, an anionic group introducer, and a blocking agent, as will be described later. When these four components are reacted, the blocking agent blocks some or all of the polyisocyanate groups in the reaction urethane prepolymer. Therefore, the difference between the four-component reactant and the three-component reactant of the polyol compound, polyisocyanate compound and anionic group introducer is whether or not the isocyanate group is blocked by the blocking agent. Only the difference, there is no essential difference in the other configurations. Since the other configurations are the same, the same effect as when the reactants of the four components are used as the component (A) is obtained as in the case of using the reactants of the three components. Therefore, the reaction product of the four components of the polyol compound, the polyisocyanate compound, the anionic group introducer, and the blocking agent is included in the component (A) used in the aqueous polyurethane composition of the present invention.

Examples of the polyol compound include polyester polyols, polycarbonate diols, polyether polyols, low molecular weight polyols having a number average molecular weight of less than 200, and the like.

The polyester polyol includes a compound obtained by esterifying a low molecular weight polyol and a polycarboxylic acid, a compound obtained by ring-opening polymerization reaction of a cyclic ester compound such as ε-caprolactone and γ-valerolactone, and a compound obtained by ring-opening polymerization reaction. Those copolymerized polyesters and the like can be used.

Examples of the low molecular weight polyol used for the polyester polyol include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol and tripropylene glycol. 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanediol, 1,6-hexanediol, 2 , 5-Hexanediol, 1,7-Heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 2- Methyl-1,3-propanediol, neopentyl glycol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, Aliper diols such as 2-methyl-1,8-octanediol and aliphatic polyols such as glycerin, trimethylolpropane, ditrimethylolpropane, tritrimethylolpropane, pentaerythritol; 1,4-cyclohexanedimethanol, hydrogenated bisphenols Examples thereof include aliphatic cyclic structure-containing polyols such as A; bisphenol compounds such as bisphenol A, bisphenol F, and bisphenol S, and alkylene oxide adducts thereof. As the low molecular weight polyol used for the polyester polyol, an aliphatic polyol and an aliphatic cyclic structure-containing polyol are preferable, an aliphatic diol is more preferable, and ethylene glycol, 1,4 is preferable from the viewpoint of light transmission and flexibility. -Butandiol and 1,6-hexanediol are more preferred. The low molecular weight polyol may be used alone or in combination of two or more.

Examples of the polycarboxylic acid used for the polyester polyol include aliphatic polycarboxylic acids such as succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, dodecandicarboxylic acid and dimer acid; 1,4-cyclohexanedicarboxylic acid. , Cyclohexanetricarboxylic acid and other alicyclic polycarboxylic acids; orthophthalic acid, isophthalic acid, terephthalic acid, 1,4-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, biphenyldicarboxylic acid, Examples thereof include aromatic polycarboxylic acids such as trimellitic acid and pyromellitic acid, and the polycarboxylic acid can be used even if it is an anhydride or an ester derivative. As the polycarboxylic acid used for the polyester polyol, an aliphatic polycarboxylic acid is preferable, an aliphatic dicarboxylic acid is more preferable, and adipic acid and sebacic acid are further preferable, from the viewpoint of light transmission and flexibility. The polycarboxylic acid may be used alone or in combination of two or more.

Examples of the polycarbonate diol include those obtained by reacting a carbonate ester and / or phosgene with a polyol. Examples of the carbonate ester include dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, ethylene carbonate, propylene carbonate, butylene carbonate, diphenyl carbonate, dinaphthyl carbonate, phenylnaphthyl carbonate and the like.

Examples of the polyol used for the polycarbonate diol include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, 1,2. -Butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanediol, 1,6-hexanediol, 2,5- Hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 2-methyl-1 , 3-Propanediol, neopentyl glycol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl Aliphatic diols such as -1,8-octanediol; aliphatic cyclic structure-containing diols such as 1,4-cyclohexanedimethanol and hydrogenated bisphenol A; hydroquinone, resorcin, bisphenol A, bisphenol F, 4,4'- Aromatic dihydroxy compounds such as biphenol; polyether polyols such as polyethylene glycol, polypropylene glycol and polytetramethylene glycol; polyester polyols such as polyhexamethylene adipate, polyhexamethylene succinate and polycaprolactone can be mentioned. As the polyol used for the polycarbonate diol, an aliphatic diol is preferable, 1,4-butanediol and 1,6-hexanediol are more preferable, and 1,6-hexanediol is preferable from the viewpoint of light transmission and flexibility. More preferred.

As the above-mentioned polyether polyol, one or more compounds having two or more active hydrogen atoms may be used as an initiator, and a compound obtained by addition polymerization of an alkylene oxide can be used.

Examples of the initiator of the polyether polyol include ethyleneglycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, and 1,4-butanediol. , 2,3-Butanediol, 1,5-pentanediol, 1,5-hexanediol, 1,6-hexanediol, 2,5-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-Nonandiol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 2-butyl-2-ethyl -1,3-propanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,8-octanediol, glycerin, diglycerin, trimethylolpropane, Ditrimethylolpropane, tritrimethylolpropane, 1,2,6-hexanetriol, triethanolamine, triisopropanolamine, pentaerythritol, dipentaerythritol, sorbitol, saccharose, ethylenediamine, N-ethyldiethylenetriamine, 1,2-diamino Examples thereof include propane, 1,3-diaminopropane, 1,2-diaminobutane, 1,3-diaminobutane, 1,4-diaminobutane, diethylenetriamine, phosphoric acid, and acidic phosphate esters.

Examples of the alkylene oxide used for the polyether polyol include ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, and tetrahydrofuran.

Examples of the low molecular weight polyol having a number average molecular weight of less than 200 include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, diethylene glycol, and triethylene glycol. 2-Butyl-2-ethyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-2,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol , 3-Methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, Adipose diols such as 3,5-heptanediol, 1,8-octanediol, 2-methyl-1,8-octanediol and 1,9-nonanediol; alicyclic diols such as cyclohexanedimethanol and cyclohexanediol; Examples thereof include trivalent or higher valent polyols such as trimethylolethane, trimethylolpropane, hexitols, pentitols, glycerin, and pentaerythritol.

As the polyol compound used as the component (A), a polycarbonate diol is preferable, a polycarbonate diol derived from an aliphatic diol is preferable, and a polycarbonate diol derived from 1,6-hexanediol is particularly preferable from the viewpoint of heat resistance and light transmission. ..

The molecular weight of the polyol compound is preferably 500 to 5000, more preferably 600 to 3000, and most preferably 700 to 2000 in terms of number average molecular weight. As the polyol compound, two or more kinds of polyol compounds having different number average molecular weights can be used in combination. The number average molecular weight of the polyol compound can be measured, for example, by gel permeation chromatography (GPC).

Examples of the polyisocyanate compound used for the component (A) include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, diphenylmethane-4,4'-diisocyanate, p-phenylene diisocyanate, and xylylene diisocyanate. Aromatic diisocyanis such as 1,5-naphthalenedisocyanis, 3,3'-dimethyldiphenyl-4,4'-diisocyanate, dianisidine diisocyanate, tetramethylxamethylene diisocyanate; isophorone diisocyanate, dicyclohexamethylene-4,4'-diisocyanate, Alicyclic diisocyanis such as trans-1,4-cyclohexamethylene diisocyanate, norbornen diisocyanate; 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,8-octamethylene diisocyanate, 2-methyl-1,5- Pentamethylene diisocyanate, 2,2-dimethyl-1,5-pentamethylene diisocyanate, 1,11-undecamethylene diisocyanate, 2,2,4-trimethyl-1,6-hexamethylene diisocyanate, 2,4,4-trimethyl Examples include aliphatic diisocyanis such as -1,6-hexamethylene diisocyanate, 2,4-dimethyl-1,8-octamethylene diisocyanate, 5-methyl-1,9-nonamethylene diisocyanis, ricin diisocyanis, and ricin methyl ester diisocyanis. Be done.

Further, as the polyisocyanate compound, the isocyanurate trimerate of the diisocyanate, the trimethylolpropane adductate of the diisocyanate, the biuret trimeride of the diisocyanate, the allophanate of the diisocyanate, the triphenylmethane triisocyanate, and 1-methylbenzol. Examples thereof include trifunctional or higher trifunctional isocyanates such as −2,4,6-triisocyanate, dimethyltriphenylmethanetetraisocyanate, 1,5,11-undecamethylene tridiisocyanate, and 2,4,6-toluentisocyanate.

As the polyisocyanate compound used as the component (A), alicyclic diisocyanate and aliphatic diisocyanate are preferable, alicyclic diisocyanate is more preferable, and dicyclohexylmethane-4 is preferable from the viewpoint of light transmission, heat resistance and adhesiveness. , 4'-diisocyanate and isophorone diisocyanate are more preferable, and dicyclohexylmethane-4,4'-diisocyanate is most preferable.

The anionic group-introducing agent used for the component (A) is an agent for introducing an anionic group into the urethane prepolymer. The anionic group-introducing agent used in the present invention has an anionic group of a carboxyl group and a sulfonic acid group. Further, the anionic group-introducing agent preferably has a functional group capable of reacting with a polyol compound or a polyisocyanate compound. Examples of such a functional group include a hydroxyl group. Examples of the anionic group-introducing agent used in the component (A) include polyols containing a carboxyl group such as dimethylol propionic acid, dimethylol butanoic acid, dimethylol butyric acid, and dimethylol valeric acid; 1,4-butanediol. Examples thereof include polyols containing a sulfonic acid group such as -2-sulfonic acid. From the viewpoint of heat resistance and industrial availability, polyols containing a carboxyl group are preferable, and dimethylolpropionic acid is more preferable.

If the content of the anionic group in the component (A) is too small, the water dispersibility of the component (A) tends to be insufficient, and if it is too large, the heat resistance may decrease. The content of the anionic group in the component is preferably 0.2 to 1.5 mmol / g, preferably 0.3 to 1.2 mmol / g, with respect to the amount of the urethane prepolymer of the component (A). It is more preferably 0.4 to 1.0 mmol / g, and most preferably 0.4 to 1.0 mmol / g. The content of anionic groups (unit: mmol / g) can be calculated from the acid value (unit: mgKOH / g). That is, the value obtained by multiplying the content of the anionic group by 56.1 (molecular weight of potassium hydroxide) corresponds to the acid value. The content of the anionic group referred to here is a molar amount with respect to the amount of the urethane prepolymer of the component (A), and when the anionic group of the component (A) is neutralized to form a salt. , The site derived from the anionic group neutralizer in the urethane prepolymer shall not be included in the above total amount. The acid value of the component (A) described above is a theoretical value obtained from the blending amount of the reaction component of the urethane prepolymer which is the component (A). The amount of the urethane prepolymer is the total amount of the polyol compound, the polyisocyanate compound and the anionic group introducer when the urethane prepolymer is a reaction product of the polyol compound, the polyisocyanate compound and the anionic group introducer. Is. The amount of urethane prepolymer is determined when the urethane prepolymer is a reaction product of a polyol compound, a polyisocyanate compound, an anionic group introducer, and a blocking agent, a polyol compound, a polyisocyanate compound, and an anion. It is the total amount of the sex group introducing agent and the blocking agent.

In the present invention, the molar ratio of isocyanate groups to hydroxyl groups is referred to as the NCO index. In the component (A) of the aqueous polyurethane resin composition of the present invention, the hydroxyl group is derived from the polyol compound and the anionic group-introducing agent, and the isocyanate group is derived from the polyisocyanate compound. Generally, the terminal group of the urethane prepolymer is an isocyanate group when the NCO index in producing the urethane prepolymer is larger than 1, and a hydroxyl group when the NCO index is smaller than 1. As the terminal group of the urethane prepolymer, an isocyanate group is preferable to a hydroxyl group because the dispersibility in water becomes high and polymerization due to chain extension becomes easy, and therefore an NCO index of more than 1 is preferable.

However, even when the NCO index is larger than 1, if it is very close to 1, a urethane prepolymer having a relatively high molecular weight but poor dispersibility in water can be easily obtained, and the NCO index is too high. If it is large, a large amount of carbon dioxide due to the reaction between the residual isocyanate group and water may be generated in the process of dispersing in water, causing rapid foaming, which may cause a manufacturing problem. There is a risk that the adhesion of objects will decrease. The NCO index for producing the component (A) is preferably 1.1 to 2.5, more preferably 1.2 to 2.0, and 1.3 to 1.8. Is the most preferable. The reaction ratio of the polyol compound, the polyisocyanate compound and the anionic group introducing agent may be determined in consideration of the content of the anionic group in the component (A) and the NCO index.

In the production of the component (A), it is preferable to use a known catalyst in order to allow the urethanization reaction to proceed smoothly. Examples of such a catalyst include N, N, N', N'-tetramethylethylenediamine, N, N, N', N'-tetramethylpropylenediamine, N, N, N', N'', N. '' -Pentamethyldiethylenetriamine, N, N, N', N'', N''-Pentamethyl- (3-aminopropyl) ethylenediamine, N, N, N', N'', N''-Pentamethyldi Propropylene triamine, N, N, N', N'-tetramethylguanidine, 1,3,5-tris (N, N-dimethylaminopropyl) hexahydro-S-triazine, 1,8-diazabicyclo [5.4.0 ] Undecene-7, triethylenediamine, N, N, N', N'-tetramethylhexamethylenediamine, N-methyl-N'-(2-dimethylaminoethyl) piperazine, N, N'-dimethylpiperazin, dimethylcyclohexyl Amine, N-methylmorpholin, N-ethylmorpholin, bis (2-dimethylaminoethyl) ether, N, N-dimethyllaurylamine, 1-methylimidazole, 1,2-dimethylimidazole, 1-isobutyl-2-methylimidazole , 1-Dimethylaminopropyl imidazole and other tertiary amines; tetraalkylammonium halides such as tetramethylammonium chloride, tetraalkylammonium hydroxides such as tetramethylammonium hydroxide salt, tetramethylammonium 2-ethylhexanoate Quaternary ammonium salts such as tetraalkylammonium organic acid salts, etc .; , Organic metal catalysts such as dioctyltin dilaurate, lead octanate, lead naphthenate, nickel naphthenate, cobalt naphthenate and the like. Among these catalysts, an organometallic catalyst is preferable, and dibutyltin dilaurate or dioctyltin dilaurate is more preferable because the reactivity is good and the obtained polyurethane resin is less yellowed. These catalysts can be used alone or in combination of two or more. The amount of the catalyst used is preferably 0.001 to 1% by mass, more preferably 0.01 to 0.1% by mass, based on the total amount of the polyol compound, the polyisocyanate compound and the anionic group-introducing agent. ..

Since the isocyanate group of the component (A) in the aqueous polyurethane resin composition of the present invention improves the adhesiveness, it is preferable that the isocyanate group is a blocked isocyanate group in which a part or the whole thereof is blocked by a blocking agent. Examples of the blocking agent include phenolic blocking agents such as phenol, cresol, xylenol, chlorophenol and ethylphenol; lactam blocking agents such as ε-caprolactam, δ-valerolactam, γ-butyrolactam and β-butyrolactam. Active oxime-based blocking agents such as ethyl acetoacetate and acetylacetone; methanol, ethanol, propanol, butanol, amyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, benzyl alcohol, methyl glycolate, glycol Alcohol-based blocking agents such as butyl acid, diacetone alcohol, methyl lactate, ethyl lactate; oxime-based blocking agents such as formaldehyde, acetaldoxime, acetoxime, methylethylketooxime, diacetylmonooxime, cyclohexaneoxime; butyl mercaptan, Mercaptan-based blocking agents such as hexyl mercaptan, t-butyl mercaptan, thiophenol, methyl thiophenol, and ethyl thiophenol; amide-based blocking agents such as acetate amide and benzamide; imide-based blocking agents such as imide succinate and imide maleate. Agents; pyrazole, 3,5-dimethylpyrazole, 4-benzyl-3,5-dimethylpyrazole, 4-nitro-3,5-dimethylpyrazole, 4-bromo-3,5-dimethylpyrazole and 3-methyl-5- Pyrazole-based blocking agents such as phenylpyrazole; imidazole-based blocking agents such as 2-ethylimidazole and the like can be mentioned. Oxime-based blocking agents and pyrazole-based blocking agents are preferable because the divergence temperature of the blocking agent from the blocked isocyanate group is slightly lower than the curing temperature of the urethane resin composition (described later) and it is easy to handle. Oxime, 3,5-dimethylpyrazole is more preferred. When the content of the blocked isocyanate group in the component (A) is too small, a sufficient adhesiveness improving effect cannot be obtained, and when all the isocyanate groups are converted into blocked isocyanate groups, the component (A) However, the molecular weight is not increased in the water dispersion step described later, and the adhesiveness is rather lowered. Therefore, the content of the blocked isocyanate group in the component (A) is the content of the polyol compound of the component (A) and the anionic group introducing agent. The excess of the isocyanate group of the polyisocyanate compound with respect to the hydroxyl group is preferably 10 to 50 mol%, more preferably 15 to 30 mol%. When calculating the content of the anionic group in the component (A), the content of the anionic group is the molar amount with respect to the total mass of the structural sites derived from the polyol compound, the polyisocyanate compound and the anionic group introducing agent. Therefore, the structural site derived from the anionic group neutralizing agent is not included in the total amount, but the structural site derived from the blocking agent is included in the total amount for calculation.

Since the water dispersibility is improved, the anionic group of the component (A) is preferably neutralized with an anionic group neutralizer. Examples of the anionic group neutralizing agent include trialkylamines such as trimethylamine, triethylamine and tributylamine; basic compounds such as ammonia, trimethylammonium hydroxide, sodium hydroxide, potassium hydroxide and lithium hydroxide. If the anionic group neutralizing agent remains in the easy-adhesion layer of the aqueous polyurethane resin composition of the present invention, the light resistance of the easy-adhesion layer may be adversely affected. A compound that dissociates and volatilizes is preferable, and trimethylamine and triethylamine are preferable.

If the amount of the anionic group neutralizing agent used is too small, the water dispersibility of the component (A) is not sufficiently improved, and if it is too large, the light resistance of the easy-adhesion layer may be adversely affected. The amount of the group neutralizing agent used is preferably 0.5 to 2.0 equivalents, more preferably 0.8 to 1.5 equivalents, relative to 1 equivalent of the anionic group.

The component (A) is preferably polymerized with a chain extender because it improves durability and adhesiveness. As will be described later, the chain extender can react with the isocyanate group of the urethane prepolymer dispersed in water to increase the molecular weight of the component (A).

Examples of the chain extender include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, diamine glycol, triethylene glycol, and 2-butyl-2-ethyl-. 1,3-Propanediol, 1,4-Butanediol, Neopentylglycol, 3-Methyl-2,4-Pentanediol, 2,4-Pentanediol, 1,5-Pentanediol, 3-Methyl-1,5 -Pentanediol, 2-methyl-2,4-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 3,5-heptandiol, 1, , 8-octanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol and other aliphatic diols; cyclohexanedimethanol, cyclohexanediol and other alicyclic diols; ethylenediamine, propylenediamine, hexamethylenediamine , Low molecular weight diamines such as tolylene diamine, piperazine, 2-methylpiperazin; polyalkylene polyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine; monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanol Alkanol amines such as amines, triisopropanolamines and 2- (2-aminoethylamino) ethanol; polyether diamines such as polyoxypropylene diamines and polyoxyethylene diamines; mensene diamines, isophorone diamines, norbornene diamines and aminoethyl aminos. Ethanol, bis (4-amino-3-methyldicyclohexyl) methane, diaminodicyclohexylmethane, bis (aminomethyl) cyclohexane, 3,9-bis (3-aminopropyl) -2,4,8,10-tetraoxaspiro ( 5,5) Alicyclic diamines such as undecane; m-xylene diamine, α- (m / p-aminophenyl) ethylamine, m-phenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, diaminodimethyldiphenylmethane, diaminodiethyldiphenylmethane, Polyamines of aromatic diamines such as dimethylthiotoluenediamine, diethyltoluenediamine, α, α'-bis (4-aminophenyl) -p-diisopropylbenzene; dihydrazide succinate, di-adipate Hydrazide, dihydrazide sebatate, dihydrazide phthalate, 1,6-hexamethylenebis (N, N-dimethylsemicarbazide), 1,1,1', 1'-tetramethyl-4,4'-(methylene-di-para) -Phenylene) Hydrazides such as disemicarbazide; hydrated hydrazine and the like. Although water functions not only as a dispersion medium but also as a chain extender, it is not included in the chain extender in the present invention because the reaction with the isocyanate group is not always rapid.

As the chain extender, low molecular weight diamines, alkanolamines, polyalkyleneamines, hydrazines, and hydrated hydrazines are preferable, and ethylenediamine and monoethanol are preferable because the reaction is easy and industrial availability is easy. Amine is more preferred. The amount of the chain extender used is such that the amount of groups capable of reacting with the isocyanate group of the chain extender is 0.01 to 1. in terms of molar ratio with respect to the isocyanate group (excluding the blocked isocyanate group) of the urethane prepolymer. It is preferably 0.

[Component (B)]
The component (B) in the water-based polyurethane resin composition of the present invention is a blocked polyisocyanate compound. Since the aqueous polyurethane resin composition is excellent in dispersibility in water, a self-emulsifying blocked polyisocyanate compound or a forced emulsifying blocked polyisocyanate compound is often used. In the present invention, the self-emulsifying blocked polyisocyanate compound means a blocked polyisocyanate compound that has emulsifying dispersibility in water and can be dispersed in water without using a surfactant, and is a forced emulsifying type. The blocked polyisocyanate compound refers to a non-emulsifying blocked polyisocyanate compound dispersed in water with a surfactant. The non-self-emulsifying blocked polyisocyanate compound means a blocked polyisocyanate compound that does not disperse in water by itself. In the self-emulsifying blocked polyisocyanate compound, a polyethylene glycol chain which is a hydrophilic group is often introduced into the molecule in order to impart self-emulsifying property. When a forced emulsifying blocked polyisocyanate compound or a self-emulsifying blocked polyisocyanate compound is used, the surfactant of the forced emulsified blocked polyisocyanate compound and the polyethylene glycol chain of the self-emulsifying blocked polyisocyanate compound are used. A non-self-emulsifying blocked polyisocyanate compound is preferable as the component (B) in the present invention because it may adversely affect the transparency of the easy-adhesion layer in a high humidity atmosphere.

Examples of the non-self-emulsifying blocked polyisocyanate compound include a compound in which the isocyanate group of the diisocyanate compound is blocked by a blocking agent, a compound in which the isocyanate group of a trifunctional or higher polyisocyanate compound is blocked by a blocking agent, and the like. From the viewpoint of adhesion, a compound in which the isocyanate group of a trifunctional or higher polyisocyanate compound is blocked with a blocking agent is preferable. Examples of such a polyisocyanate compound include isocyanurate trimerates of diisocyanate exemplified by the polyisocyanate compound of component (A), trimethyl propane adductate of diisocyanate, biuret trimeride of diisocyanate, allophanate of diisocyanate, and triphenyl. Trifunctionals such as methanetriisocyanate, 1-methylbenzol-2,4,6-triisocyanate, dimethyltriphenylmethanetetraisocyanate, 1,5,11-undecamethylene tridiisocyanate, 2,4,6-toluentisocyanate, etc. The above isocyanates and the like can be mentioned. Further, the trifunctional or higher polyisocyanate compounds may be linked with a polyol compound. Examples of the blocking agent for the non-self-emulsifying blocked polyisocyanate compound include the compounds exemplified by the blocking agent for the component (A), and the deviation temperature of the blocking agent from the blocked isocyanate group is the urethane resin composition. Oxime-based blocking agents and pyrazole-based blocking agents are preferable, and methylethylketooxime and 3,5-dimethylpyrazole are more preferable because they are slightly lower than the curing temperature (described later) and are easy to handle. Particularly preferable components (B) are those in which the isocyanurate trimerate of hexamethylene diisocyanate is blocked with methyl ethyl ketooxime, and those in which the isocyanurate trimerate of hexamethylene diisocyanate is blocked with 3,5-dimethylpyrazole. Hexamethylene diisocyanate isocyanurate trimerate is linked with polytetramethylene glycol and blocked with methyl ethyl ketooxime, and hexamethylene diisocyanate isocyanurate trimerate is linked with polytetramethylene glycol and blocked with 3,5-dimethylpyrazole. Examples include those that have been converted.

The weight average molecular weight of the blocked polyisocyanate compound of the component (B) used in the aqueous polyurethane resin of the present invention is not particularly limited, but is preferably 50,000 or less. When the weight average molecular weight of the blocked polyisocyanate compound of the component (B) is more than 50,000, the viscosity of the blocked polyisocyanate compound increases and the handleability deteriorates. The weight average molecular weight of the blocked polyisocyanate compound can be measured, for example, by gel permeation chromatography (GPC).

In the aqueous polyurethane resin composition of the present invention, the content of the blocked isocyanate group is 0.5 to 4 mmol / g with respect to the solid content. If the content of the blocked isocyanate group is less than 0.5 mmol / g, the adhesion to the substrate becomes insufficient, and if it exceeds 4 mmol / g, the flexibility of the easy-adhesion layer decreases, or relatively ( The content of the component (B) may increase, and the dispersion stability of the component (B) may decrease. The content of the blocked isocyanate group is preferably 0.7 mmol / g or more, more preferably 0.9 mmol / g or more, and even more preferably 1.0 mmol / g or more with respect to the solid content. The content of the blocked isocyanate group is preferably 3.9 mmol / g or less, more preferably 3.8 mmol / g or less, more preferably 3.7 mmol / g or less, still more preferably 2 mmol / g or less, based on the solid content. It is more preferably 1.9 mmol / g or less, particularly preferably 1.8 mmol / g or less, and most preferably 1.7 mmol / g or less. In the present invention, the solid content refers to a component other than the volatile components such as water and organic solvent in the composition, and is calculated from, for example, the volatile residue when the composition is heated at 105 ° C. for 1 hour. be able to.

The ratio of the component (A) to the component (B) of the aqueous polyurethane resin composition of the present invention is not particularly limited as long as the content of the blocked isocyanate group is 0.5 to 4 mmol / g with respect to the solid content. If the amount of the component (A) is too small, the dispersion stability of the component (B) is lowered. Therefore, the content of the component (A) as a solid content is the total amount of the component (A) and the component (B) as a solid content. It is preferably at least 20 parts by mass, and more preferably at least 25 parts by mass with respect to 100 parts by mass.

The smaller the amount of water in the aqueous polyurethane resin composition of the present invention is, the larger the amount of active ingredient is, which is preferable. However, if it is too small, the dispersion stability is lowered. Therefore, the aqueous polyurethane resin composition of the present invention The amount of water in the water is preferably 60 to 1000 parts by mass, more preferably 100 to 400 parts by mass, and most preferably 150 to 250 parts by mass with respect to 100 parts by mass of the solid content of the aqueous polyurethane resin composition of the present invention. ..

[Other additives]
Known additives can be added to the water-based polyurethane resin composition of the present invention as long as the effects of the present invention are not impaired. Such additives include, for example, cross-linking agents, various weather resistant agents (hindered amine-based light stabilizers, ultraviolet absorbers and antioxidants), silane coupling agents that particularly strengthen adhesion to substrates, colloidal silica or Inorganic colloidal sol such as colloidal alumina, tetraalkoxysilane and its polycondensate, chelating agent, epoxy compound, pigment, dye, film-forming aid, curing agent, external cross-linking agent, viscosity modifier, leveling agent, defoaming agent, coagulation Antistatic agents, radical trapping agents, heat resistance imparting agents, inorganic or organic fillers, plasticizers, lubricants, antistatic agents such as fluorine-based or siloxane-based agents, reinforcing agents, catalysts, rocking agents, waxes, antifogging agents , Antibacterial agents, antifungal agents, anticorrosive agents, anticorrosive agents and the like can be used.

The durability of the above-mentioned cross-linking agent can be improved by introducing a cross-linked structure into the water-based polyurethane resin composition of the present invention. Examples of the cross-linking agent include an adduct of urea, a melamine compound, benzoguanamine and the like and formaldehyde, an amino resin composed of the adduct and an alkyl ether compound containing an alcohol unit having 1 to 6 carbon atoms, and a polyfunctional epoxy compound; Polyfunctional isocyanate compound; Polyfunctional aziridine compound and the like can be mentioned, and a melamine compound is preferable because it has excellent reactivity. Examples of the melamine compound include melamine, monomethylol melamine, dimethylol melamine, trimethyl melamine, tetramethylol melamine, pentamethylol melamine, hexamethylol melamine, methylated methylol melamine, butylated methylol melamine, and melamine resin. Melamine is preferable because it is inexpensive and has excellent dispersibility.

Examples of the hindered amine-based light stabilizer include 1,6-bis (2,2,6,6-tetramethyl-4-piperidylamino) hexane / dibromoethane polycondensate and 1,6-bis (2,2). , 6,6-Tetramethyl-4-piperidylamino) hexane / 2,4-dichloro-6-morpholino-s-triazine polycondensate, 1,6-bis (2,2,6,6-tetramethyl-4) -Piperidylamino) hexane / 2,4-dichloro-6-third octylamino-s-triazine polycondensate, 1,5,8,12-tetrakis [2,4-bis (N-butyl-N- (2) , 2,6,6-tetramethyl-4-piperidyl) amino) -s-triazine-6-yl] -1,5,8,12-tetraazadodecane, 1,5,8,12-tetrakis [2, 4-Bis (N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino) -s-triazine-6-yl] -1,5,8,12-tetraazadodecane , 1,6,11-Tris [2,4-bis (N-butyl-N- (2,2,6,6-tetramethyl-4-piperidyl) amino) -s-triazine-6-ylaminoundecane, 1,6,11-Tris [2,4-bis (N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino) -s-triazine-6-ylaminoundecane, etc. Can be mentioned.

Examples of the ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, and 5,5'-methylenebis (2-hydroxy-4-methoxybenzophenone). 2- (2-Hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy-5-third octylphenyl) benzotriazole, 2- (2-hydroxy-3, 5-Dith Butylphenyl) -5-Chlorobenzotriazole, 2- (2-Hydroxy-3-3rd Butyl-5-Methylphenyl) -5-Chlorobenzotriazole, 2- (2-Hydroxy-3,5) -Dicumylphenyl) benzotriazole, 2,2'-methylenebis (4-thioctyl-6-benzotriazolylphenol), 2- (2-hydroxy-3-3th butyl-5-carboxyphenyl) benzotriazole Polyethylene glycol ester, 2- [2-hydroxy-3- (2-acryloyloxyethyl) -5-methylphenyl] benzotriazole, 2- [2-hydroxy-3- (2-methacryloyloxyethyl) -5th 3 Butylphenyl] benzotriazole, 2- [2-hydroxy-3- (2-methacryloyloxyethyl) -5-third octylphenyl] benzotriazole, 2- [2-hydroxy-3- (2-methacryloyloxyethyl)) -5-Third Butylphenyl] -5-Chlorobenzotriazole, 2- [2-Hydroxy-5- (2-methacryloyloxyethyl) phenyl] benzotriazole, 2- [2-Hydroxy-3-3rd Butyl-5 -(2-Methacryloxyethyl) phenyl] benzotriazole, 2- [2-hydroxy-3-3rd amyl-5- (2-methacryloyloxyethyl) phenyl] benzotriazole, 2- [2-hydroxy-3-th 3 Butyl-5- (3-methacryloyloxypropyl) phenyl] -5-chlorobenzotriazole, 2- [2-hydroxy-4- (2-methacryloyloxymethyl) phenyl] benzotriazole, 2- [2-hydroxy-4 2- (2-Hydroxypheni) such as-(3-methacryloyloxy-2-hydroxypropyl) phenyl] benzotriazole, 2- [2-hydroxy-4- (3-methacryloyloxypropyl) phenyl] benzotriazole, etc. Le) Benzotriazoles; 2- (2-hydroxy-4-methoxyphenyl) -4,6-diphenyl-1,3,5-triazine, 2- (2-hydroxy-4-hexyloxyphenyl) -4,6 -Diphenyl-1,3,5-triazine, 2- (2-hydroxy-4-octoxyphenyl) -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2-[ 2-Hydroxy-4- (3-C12-C13 mixed alkoxy-2-hydroxypropoxy) phenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- [2- [2- Hydroxy-4- (2-acryloyloxyethoxy) phenyl] -4,6-bis (4-methylphenyl) -1,3,5-triazine, 2- (2,4-dihydroxy-3-allylphenyl) -4 , 6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2,4,6-tris (2-hydroxy-3-methyl-4-hexyloxyphenyl) -1,3,5- 2- (2-Hydroxyphenyl) -4,6-diaryl-1,3,5-triazines such as triazine; phenylsalicylate, resorcinol monobenzoate, 2,4-dithiary butylphenyl-3,5-dith. 3butyl-4-hydroxybenzoate, octyl (3,5-dith butyl-4-hydroxy) benzoate, dodecyl (3,5-dith) benzoate, tetradecyl (3,5-dith) 3 butyl-4-hydroxy) benzoate, hexadecyl (3,5-dith butyl-4-hydroxy) benzoate, octadecyl (3,5-dith butyl-4-hydroxy) benzoate, behenyl (3,5-di) Phenylates such as ternary butyl-4-hydroxy) benzoate; substituted oxanilides such as 2-ethyl-2'-ethoxyoxanilide, 2-ethoxy-4'-dodecyloxanilide; ethyl-α-cyano-β , Β-Diphenyl acrylate, cyanoacrylates such as methyl-2-cyano-3-methyl-3- (p-methoxyphenyl) acrylate; and various metal salts or metal chelate, such as nickel or chromium salts or chelates, etc. Is used.

As the antioxidant, a phosphorus-based antioxidant, a phenol-based antioxidant, and a sulfur-based antioxidant can be used. Examples of phosphorus-based antioxidants include triphenyl phosphite, tris (2,4-dith butylphenyl) phosphite, tris (2,5-dithirth butylphenyl) phosphite, and tris (nonylphenyl). Phosphite, Tris (dinonylphenyl) phosphite, Tris (mono, dimixed nonylphenyl) phosphite, diphenylacid phosphite, 2,2'-methylenebis (4,6-dithibylphenyl) octylphosphite, Diphenyldecylphosphite, diphenyloctylphosphite, di (nonylphenyl) pentaerythritol diphosphite, phenyldiisodecylphosphite, tributylphosphite, tris (2-ethylhexyl) phosphite, tridecylphosphite, trilaurylphosphite, dibutyl Acid phosphite, dilauryl acid phosphite, trilauryl trithiophosphite, bis (neopentylglycol) -1,4-cyclohexanedimethyldiphosphite, bis (2,4-dithibylphenyl) pentaerythritol diphosphite , Bis (2,5-dith butylphenyl) pentaerythritol diphosphite, bis (2,6-dith butyl-4-methylphenyl) pentaerythritol diphosphite, bis (2,4-dicumylphenyl) ) Pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, tetra (mixed alkyl of C12 alkyl to C15 alkyl) -4,4'-isopropyridene diphenylphosphite, bis [2,2'-methylenebis (4,6) -Diamilphenyl)]-isopropyridene diphenylphosphite, tetratridecyl-4,4'-butylidenebis (2-third butyl-5-methylphenol) diphosphite, hexa (tridecyl) -1,1,3-tris ( 2-Methyl-5th Butyl-4-Hydroxyphenyl) Butane Triphosphite, Tetraquis (2,4-Dith Butylphenyl) Biphenylenediphosphonite, Tris (2-[(2,4,7,9) -Tetraxyl butyldibenzo [d, f] [1,3,2] dioxaphosfepine-6-yl) oxy] ethyl) amine, 9,10-dihydro-9-oxa-10-phosphaphenance Len-10-oxide, tris (2-[(2,4,8,10-tetrax tertiary butyldibenzo [d, f] [1,3,2] dioxaphos Fepin-6-yl) oxy] ethylamine, 2- (1,1-dimethylethyl) -6-methyl-4- [3-[[2,4,8,10-tetrakis (1,1-dimethylethyl) dibenzo [D, f] [1,3,2] dioxaphosphepine-6-yl] oxy] propyl] phenol, and 2-butyl-2-ethylpropanediol-2,4,6-tritrith butylphenol mono Phosphite or the like can be used.

Examples of the phenolic antioxidant include 2,6-dith butyl-p-cresol, 2,6-diphenyl-4-octadecyloxyphenol, and stearyl (3,5-dithbutyl-4-). Hydroxyphenyl) propionate, distearyl (3,5-dith butyl-4-hydroxybenzyl) phosphonate, tridecyl 3,5-dithibyl-4-hydroxybenzylthioacetate, thiodiethylenebis [(3,5) -3 Butyl-4-hydroxyphenyl) propionate], 4,4'-thiobis (6-thibyl-m-cresol), 2-octylthio-4,6-di (3,5-di-tertiary butyl) -4-Hydroxyphenoxy) -s-triazine, 2,2'-methylenebis (4-methyl-6-3 butylphenol), bis [3,3-bis (4-hydroxy-3-3 butylphenyl) butyl Acid] Glycolester, 4,4'-butylidenebis (2,6-di-3 butylphenol), 4,4'-butylidenebis (6-3 butyl-3-methylphenol), 2,2'-ethylidenebis (4) , 6-Dith Butylphenol), 1,1,3-Tris (2-Methyl-4-hydroxy-5-Third Butylphenyl) Butan, Bis [2-Third Butyl-4-Methyl-6- (2) −Hydroxy-3-3rd Butyl-5-Methylbenzyl) phenyl] terephthalate, 1,3,5-tris (2,6-dimethyl-3-hydroxy-4-3th butylbenzyl) isocyanurate, 1,3 5-Tris (3,5-Dith Butyl-4-Hydroxybenzyl) isocyanurate, 1,3,5-Tris (3,5-Dith Butyl-4-Hydroxybenzyl) -2,4,6- Trimethylbenzene, 1,3,5-tris [(3,5-dithiary butyl-4-hydroxyphenyl) propionyloxyethyl] isocyanurate, tetrakis [methylene-3- (3', 5'-dithirth butyl) -4'-Hydroxyphenyl) propionate] methane, 2-3th butyl-4-methyl-6- (2-acroyloxy-3-3rd butyl-5-methylbenzyl) phenol, 3,9-bis [2 -(3-3 Butyl-4-hydroxy-5-methylhydrocinnamoyloxy) -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5.5] undecane, triethylene glycol Bis [β- (3-th butyl-4-hydroxy-5-methylphenyl) Lopionate], tocopherol and the like can be used.

Examples of the sulfur-based antioxidant include dialkylthiodipropionates such as dilauryl, dimyristyl, myristylstearyl, and distearyl ester of thiodipropionic acid, pentaerythritol tetra (β-dodecyl mercaptopropionate), and the like. The β-alkyl mercaptopropionic acid esters of polyols can be used.

The amount of the weather resistant agent (hindered amine-based light stabilizer, ultraviolet absorber, and antioxidant) used is preferably 0.001 to 10 parts by mass, more preferably 0.001 to 10 parts by mass, based on 100 parts by mass of the solid content of the aqueous polyurethane resin composition. It is 0.01 to 5 parts by mass. If the amount of the weatherproofing agent is less than 0.001 part by mass with respect to 100 parts by mass of the solid content, a sufficient addition effect may not be obtained. If the amount of the weathering agent is more than 10 parts by mass with respect to 100 parts by mass of the solid content, the water dispersion stability and the physical characteristics of the coating film may be adversely affected.
The total amount of other additives including the weather resistant agent is preferably 25 parts by mass or less in total with respect to 100 parts by mass of the solid content of the aqueous polyurethane resin composition.

When such a known additive is used, a surfactant may be used as a dispersant or an emulsifier. If the content of the surfactant in the aqueous polyurethane resin composition is high, the transparency of the easy-adhesion layer in a high humidity atmosphere may be adversely affected. Therefore, the content of the surfactant in the water-based polyurethane resin composition of the present invention is preferably 1 part by mass or less, preferably 0.2 parts by mass, based on 100 parts by mass of the solid content of the water-based polyurethane resin composition. The following is more preferable.

〔Production method〕
The water-based polyurethane resin composition of the present invention is characterized by containing a blocked polyisocyanate compound as a component (B) and containing a blocked isocyanate group at a high concentration. When the component (B) is a self-emulsifying blocked polyisocyanate compound or a forced emulsifying blocked polyisocyanate compound, the component (B) can be blended even after the component (A) is dispersed in water. Although it is easy, when the component (B) is a non-self-emulsifying blocked polyisocyanate compound, it is difficult to add the component (B) after dispersing the component (A) in water. Hereinafter, the production method when the component (B) is a non-self-emulsifying blocked polyisocyanate compound will be described.

In the production of the aqueous polyurethane resin composition of the present invention, first, a polyol compound, a polyisocyanate compound, and an anionic group-introducing agent are reacted by optionally adding a catalyst or a cross-linking agent, and the urethane prepolymer of the component (A) is reacted. To manufacture. The urethane prepolymer can be produced by a conventional method, and the reaction temperature can be a normal reaction temperature for urethanization, for example, 50 to 100 ° C., and does not react with the isocyanate group in order to proceed smoothly. An inert solvent can also be used. The inert solvent used in the production is preferably an organic solvent having a high affinity with water because it does not inhibit the water dispersibility of the urethane prepolymer. For example, acetone, methyl ethyl ketone, dioxane, tetrahydrofuran, N-methyl-2- Pyrrolidone, N-ethyl-2-pyrrolidone and the like are preferable. The amount of the solvent used is preferably 3 to 200 parts by mass with respect to 100 parts by mass of the total amount of the polyol compound, the polyisocyanate compound, and the anionic group-introducing agent.

When the isocyanate group of the component (A) is blocked with a blocking agent, the blocking agent can be charged at the same time as the polyisocyanate compound or the like at the time of producing the urethane prepolymer, or the urethanization reaction can be carried out. It is also possible to charge a blocking agent during or after the end to react. The reaction temperature of the blocking agent varies depending on the blocking agent, but is preferably 50 to 100 ° C. in the case of an oxime-based blocking agent or a pyrazole-based blocking agent.

Since the non-self-emulsifying blocked polyisocyanate is difficult to disperse in water, the urethane prepolymer of the component (A) and the non-self-emulsifying blocked polyisocyanate of the component (B) are mixed and then dispersed in water. By mixing the component (A) and the component (B) and then dispersing them in water, the component (B), which was difficult to disperse in water, can also be dispersed in water. Since it has emulsifying properties, it is considered that the component (A) functions as an emulsifier for the component (B), so that the component (B) can be dispersed. As a method of dispersing in water, a prepolymer mixing method and a phase inversion method are preferable because the dispersibility in water is good. In the prepolymer mixing method, an anionic group neutralizing agent is added to the urethane prepolymer of the component (A) and mixed, and then the mixture is poured into water and dispersed in water. In the phase inversion method, the urethane of the component (A) is used. Water containing an anionic group neutralizing agent is added to the prepolymer, or an anionic group neutralizing agent is added to the urethane prepolymer of the component (A) and mixed, and then water is added to the mixture to disperse it in water. In any of the methods, the timing of mixing the component (A) and the component (B) is not particularly limited as long as the component (A) is before coexisting with water, but the urethane prepolymer is neutralized with an anionic group. When the agent is added and mixed, it is preferable to add and mix the anionic group neutralizing agent together with the component (B).

When the component (A) and the component (B) are dispersed in water, if the temperature of the water is too high, the rapid reaction between the isocyanate group of the urethane prepolymer and the water may cause a foaming phenomenon accompanying the generation of carbon dioxide. Therefore, the temperature of water is preferably 75 ° C. or lower, more preferably 65 ° C. or lower.

When a chain extender is used, it is dissolved in water used for dispersing the component (A) and the component (B). When a chain extender is used, if the temperature of water is low, it takes a long time for the reaction to reduce the production efficiency, and if it is too high, the rapid reaction between the isocyanate group and water causes the generation of carbon dioxide. Since a foaming phenomenon may occur, the temperature of water when the chain extender is used is preferably 20 to 75 ° C, more preferably 30 to 65 ° C. As a method for determining the end point of the reaction in the chain extension, a method for confirming the disappearance of the isocyanate group using an IR (infrared spectrophotometer) is preferable because it is simple.

When the other additives are blended, the water-soluble or water-dispersible additive is preferably blended after the components (A) and (B) are dispersed in water, and is water-insoluble and non-aqueous-dispersible. The additive of is preferably mixed with the urethane prepolymer of the component (A) and then dispersed in water, similarly to the component (B).

When an organic solvent is used for the production of the component (A), the aqueous polyurethane resin composition contains the organic solvent, but from the viewpoint of safety such as environmental pollution and occupational hygiene, the aqueous polyurethane resin composition The organic solvent in the substance is preferably removed by a method such as distillation under reduced pressure.

[Use]
The water-based polyurethane resin composition of the present invention can be used as various adhesives because it is excellent in adhesion to a substrate, blocking resistance, transparency, heat resistance, etc. It can be suitably used as an easy-adhesion layer. An optical film is a film that transmits or reflects and absorbs light rays to give various effects. Optical films include reflective films, antireflection films, alignment films, polarizing films, polarizing layer protective films, retardation films, viewing angle improving films, brightness improving films, electromagnetic wave shielding films, light shielding films, specific frequency selective blocking films, and optics. Examples thereof include low-pass filters, lens filters, conductive films for touch panels, light diffusing films, antiglare films, and prism sheets. As the resin film base material of the optical film, polyester resins such as polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), and polybutylene terephthalate (PBT) are generally used because of their excellent transparency, flexibility, and physical strength. used. Since the conventional water-based polyurethane resin composition used for the easy-adhesion layer of the optical film has insufficient adhesion to the polyester resin of the base material and the easy-adhesion layer, the surface of the base material is treated with corona. In some cases, the surface was modified by plasma treatment, glow discharge treatment, or the like. Since the water-based polyurethane resin composition of the present invention has excellent adhesion to the polyester resin, high adhesion can be obtained even on such a base material that has not been surface-treated, and an adhesive for the polyester resin. Above all, it can be suitably used as an easy-adhesion layer of an optical film that requires transparency and adhesion. Since the water-based polyurethane resin composition of the present invention is also excellent in adhesion to an acrylic resin, an optical sheet in which an acrylic resin is used, for example, a polarizing film, a light diffusing film, a reflective film, an antireflection film, and an anti-reflection film. It is preferably used as an easy-adhesion layer for a dazzling film, a prism sheet, etc., and particularly preferably as an easy-adhesion layer for a prism sheet or the like.

The water-based polyurethane resin composition of the present invention can be applied to a base material, dried, and then heat-treated to be cured to form an easy-adhesion layer. The method for applying the water-based polyurethane resin composition of the present invention is not particularly limited, and known methods can be used. For example, a slit coater method such as a curtain flow coater method or a die coater method, a knife coater method, or a roll coater method can be used. Etc. can be used.

The coating film of the water-based polyurethane resin composition of the present invention is cured by heating above the deviation temperature of the blocking agent. That is, by heating, the blocking agent is dissociated from the blocked isocyanate group, the active isocyanate group is regenerated, and the group reacts with the hydroxyl group and the amino group to generate a urethane group and a urea group, thereby curing. The dissociation temperature of the blocked isocyanate group is about 140 to 160 ° C. for the oxime-based blocking agent and about 110 to 120 ° C. for the pyrazole-based blocking agent. When the temperature is high, not only the isocyanate group reacts with the urethane group and the urea group to generate an allophanate group and a burette group and crosslink the group, but these groups also improve the adhesion of the easy-adhesion layer. Therefore, it is preferable that the heating temperature is high, but if the heating temperature is too high, the base material and the easy-adhesion layer may be thermally deteriorated. Therefore, the heating temperature of the coating film of the water-based polyurethane resin composition of the present invention is preferably 150 to 250 ° C, more preferably 160 to 210 ° C, and most preferably 170 to 190 ° C. The heating time varies depending on the heating temperature, but when the heating temperature is 180 ° C., 1 to 30 minutes is a guide. The heating method is not particularly limited, and for example, known heating methods such as hot air heating, infrared heating, and high frequency heating can be applied.

Hereinafter, the present invention will be specifically described with reference to Examples.
In the following examples and the like, the blending ratio (%) means a mass-based ratio unless otherwise specified. The raw materials used in the following production examples, examples and comparative examples are as follows.

Polyol a1: Polypolydiol polyol a2 with a number average molecular weight of 2000: Polytetramethylene glycol monool with a number average molecular weight of 1000 a'1: Polyethylene glycol monomethyl ether polyisocyanate b1: isophorone diisocyanate polyisocyanate b2: dicyclohexylmethane- 4,4'-Diisocyanate polyisocyanate b3: isocyanurate trimerid of hexamethylene diisocyanate (isocyanate content 21.8%)
Anionic group introducer c1: Dimethylolpropionic acid Anionic group neutralizer d1: Triethylamine chain extender e1: Ethylenediamine chain extender e2: Monoethanolamine blocking agent f1: Methylethylketooxime blocking agent f2: 3,5- Dimethylpyrazole MEK: Methylethylketone

[Production Example 1: Prepolymer A1]
In a glass reaction vessel with a stirrer, cooling tube and nitrogen introduction tube, 313.9 g of polyol a1, 280.0 g of polyisocyanate b1, 80.8 g of anionic group introducer c1, 250 g of MEK, and 14. 4 g of the blocking agent f1 was charged, and the mixture was stirred and reacted at 80 ° C. for 5 hours to produce a solvent-containing prepolymer A1. The content of the anionic group in the prepolymer A1 is 0.642 mmol / g, and the content of the anionic group when the solvent is removed is 0.875 mmol / g. The content of the blocked isocyanate group (hereinafter, also referred to as B-NCO) in the prepolymer A1 is 0.177 mmol / g, and the content of the blocked isocyanate group with respect to the solid content of the prepolymer A1 is 0.241 mmol / g. Is.

[Production Examples 2-8: Prepolymers A2-8]
Urethane prepolymers A2 to A8 were produced by performing the same operations as in Production Example 1 except that the amount of each raw material charged was changed as shown in Table 1.
The numerical value of the amount of each raw material charged in Table 1 is the number of g. The values of the anionic group and B-NCO contents in the upper row are the values for the solid content of the prepolymer, and the values in () in the lower row are the values for the prepolymer containing a solvent.

[Production Example 9: Blocked Polyisocyanate B1]
506.4 g of polyisocyanate b3, 230.9 g of blocking agent f1, 12.7 g of polyol a2 as a linking agent, and 250 g of MEK as a solvent in a glass reaction vessel having a stirrer, a cooling tube, and a nitrogen introduction tube. The mixture was charged and stirred at 80 ° C. for 5 hours to react to obtain a blocked polyisocyanate B1 containing MEK. The B-NCO content of the blocked polyisocyanate B1 is 2.60 mmol / g, and the B-NCO content with respect to the solid content is 3.47 mmol / g. The blocked polyisocyanate B1 is a non-self-emulsifying blocked polyisocyanate compound.

[Production Examples 10 to 11 and 13: Blocked Polyisocyanates B2, B3, B5]
Blocked polyisocyanates B2, B3 and B5 were produced in the same manner as in Production Example 8 except that the amount (g) of each raw material charged was changed as shown in Table 2. The blocked polyisocyanates B2 and B5 are non-self-emulsifying blocked polyisocyanates, and the blocked polyisocyanate B3 is a self-emulsifying blocked polyisocyanate compound.

[Production Example 12: Blocked Polyisocyanate B4]
50 g of blocked polyisocyanate B1, 5 g of nonionic surfactant (manufactured by ADEKA Corporation, trade name: Adecanol SP-12, HLB: 12.7), 45 g of water treated with a homomixer to block A blocked polyisocyanate B4, which is an emulsified dispersion of the polyisocyanate B1, was obtained. Blocked polyisocyanate B4 is a forced emulsified blocked polyisocyanate compound.

Table 2 shows the charged amount (g) of each raw material of the blocked polyisocyanates B1 to 5 and the content of B-NCO. As for the value of B-NCO content, the value in the upper row is a value with respect to the solid content of the blocked polyisocyanate, and the value in () in the lower row is a value containing a solvent.

[Example 1]
A resin container was charged with 56.35 g of prepolymer A1, 3.65 g of anionic group neutralizer d1 and 40 g of blocked polyisocyanate B1 and stirred for 5 minutes to obtain a mixture. The amount of the anionic group neutralizing agent used is the same as that of the anionic group introducing agent in the blepolymer. In a glass reaction vessel having a stirrer, 150 g of water and 0.02 g of a defoaming agent (manufactured by ADEKA Corporation, trade name: ADEKANET B-1016) are charged, and the mixture is mixed at 40 ° C. The mixture was added over a minute and further stirred at 40 ° C. for 30 minutes. A 25 mass% aqueous solution of 0.224 g of the chain extender e1 (0.056 g as the chain extender e1) was added, and the mixture was stirred at 40 ° C. for 1 hour, and then MEK was removed under reduced pressure conditions. An aqueous polyurethane resin composition was obtained. Example 1 is an example using a non-self-emulsifying blocked polyisocyanate compound.

[Examples 2 to 10, Comparative Examples 1 to 8]
The same operations as in Example 1 were carried out except that the amount (g) of each raw material charged was changed as shown in Table 3, to obtain water-based polyurethane resin compositions of Examples 2 to 10 and Comparative Examples 1 to 8. .. In Table 3, the amount of the anionic group neutralizing agent used is the same molar amount as that of the anionic group introducing agent in the blepolymer, and the amount of the chain extenders e1 and e2 charged is the amount of the 25% aqueous solution. .. Examples 2 to 10 and Comparative Examples 1 to 8 are examples in which a non-self-emulsifying blocked polyisocyanate compound is used.

[Example 11]
A resin container was charged with 46.95 g of prepolymer A1 and 3.05 g of anionic group neutralizer d1 and stirred for 5 minutes to obtain a mixture. In a glass reaction vessel having a stirrer, 150 g of water and 0.02 g of a defoaming agent (manufactured by ADEKA Corporation, trade name: Adecanate B-1016) are charged, and the mixture is mixed with 2 at 40 ° C. The mixture was added over a minute, and the mixture was further stirred at 40 ° C. for 30 minutes, then 0.19 g of a 25% by mass aqueous solution of the chain extender e1 was added, and the mixture was stirred at 40 ° C. for 1 hour. To this, 50 g of blocked polyisocyanate B3 was added, and the mixture was stirred and dispersed at 40 ° C. for 1 hour, and then MEK was removed under reduced pressure conditions to obtain the aqueous polyurethane resin composition of Example 11. Example 11 is an example using a self-emulsifying blocked polyisocyanate compound.

[Example 12]
A resin container was charged with 56.35 g of prepolymer A1 and 3.65 g of anionic group neutralizer d1 and stirred for 5 minutes to obtain a mixture. 120 g of water, 0.02 g of antifoaming agent (manufactured by ADEKA Corporation, trade name: ADEKANET B-1016), and 70 g of blocked polyisocyanate B4 are charged in a glass reaction vessel having a stirrer at 40 ° C. The mixture was added over 2 minutes with stirring. Further, after stirring at 40 ° C. for 30 minutes, 0.23 g of a 25% by mass aqueous solution of the chain extender e1 was added, and the mixture was stirred at 40 ° C. for 1 hour. Then, MEK was removed under reduced pressure conditions to obtain the aqueous polyurethane resin composition of Example 12. Example 12 is an example using a forced emulsification type blocked polyisocyanate compound.

Table 3 shows the amount (g) of each raw material charged in the water-based polyurethane resin compositions of Examples 1 to 12 and Comparative Examples 1 to 8. The (A) / (B) ratio in Table 3 is the mass ratio of the solid content of the component (A) and the component (B), and the value of the B-NCO content is a value with respect to the solid content.

The water-based polyurethane resin compositions of Examples 1 to 12 and Comparative Examples 1 to 8 were tested for storage stability, adhesion, moisture transparency and blocking resistance by the following methods, respectively. The following test pieces A to C were used for the evaluation of adhesion, and the following test pieces A were used for the evaluation of moisture transparency and blocking resistance. The results are shown in Table 4.

Test piece A: A water-based polyurethane resin composition was applied to a commercially available PET film (thickness 20 μm, uncorona treated, surface average water contact angle 70 °) so that the thickness of the coating film after drying was about 1 μm. After air-drying at 25 ° C., the test piece A was prepared by heating at 180 ° C. for 10 minutes.
Test piece B: A commercially available PET film is corona-treated with a corona treatment device until the average water contact angle of the surface becomes 28 to 32 °, and then the thickness of the coating film after drying on this film is about 1 μm. A water-based urethane resin composition was applied, air-dried at 25 ° C., and then heated at 180 ° C. for 10 minutes to prepare a test piece B.
Test piece C: Commercially available acrylic photocurable resin (manufactured by ADEKA Corporation, trade name: ADEKA PUTMER HC-211) so that the thickness of the test piece B is about 3 μm on the surface coated with the urethane resin. -9) was applied, dried at 80 ° C., ^{and then cured using a metal halide lamp under the conditions of an intensity of 600 mW / cm 2} and an integrated light amount of 500 mJ / cm ² , to prepare a test piece C.

<Storage stability test method>
The aqueous polyurethane resin composition was placed in a closed container and stored at 40 ° C. for 24 hours, and then the storage stability was evaluated based on the following evaluation criteria based on the presence or absence of separation. Those with poor storage stability were not subjected to the subsequent tests.
(Evaluation criteria)
◯: Separation is not seen and storage stability is good ×: Separation is seen and storage stability is poor

<Adhesion test method>
Tested in accordance with JIS K5600-5-6 (General paint test method-Part 5: Mechanical properties of coating film-Section 6: Adhesiveness (cross-cut method)) using a cutter guide with a gap spacing of 1 mm. One piece of urethane-based cured film was cut into 100 squares. After attaching the adhesive tape to the cut cured film, the adhesive tape was peeled off at an angle of about 60 ° with respect to the peeling direction. After the operation of attaching and peeling the adhesive tape to the same test piece was performed three times, the number of cells that did not peel off was counted. The larger the number of cells that have not been peeled off, the higher the adhesion.

<Moisture resistance transparency test method>
After allowing the test piece A to stand in a constant temperature and humidity chamber at 80 ° C. and a relative humidity of 80% for 250 hours, the haze value (%) is measured using a haze meter (manufactured by Nippon Denshoku Kogyo Co., Ltd., model: NDH-5000). bottom. The value obtained by subtracting the haze value of the commercially available PET film used for preparing the test piece A from this value was defined as ΔH. The larger ΔH, the lower the transparency of the urethane-based cured film, or the lower the transparency by the moisture-resistant transparency test.

<Blocking resistance test method>
Using two test pieces A, the urethane-based cured film surfaces are overlapped with each other, sandwiched between two glass plates, and ^{a load of 10 kgf / cm 2} is applied to a constant temperature and humidity chamber at 60 ° C. and a relative humidity of 80%. It was allowed to stand for 24 hours. Then, the overlapping test pieces were peeled off, and the ratio (%) of the area of the damaged surface to the area of the overlapped surface of the urethane-based cured film surface was calculated. The smaller the ratio of the area of the damaged surface, the higher the blocking resistance.

[Examples 13 and 14, Comparative Example 9]
The same operations as in Example 1 were carried out except that the amount (g) of each raw material charged was changed as shown in Table 5, to obtain water-based polyurethane resin compositions of Examples 13 and 14 and Comparative Example 9. In Table 5, the amount of the anionic group neutralizing agent used is the same molar amount as that of the anionic group introducing agent in the prepolymer, and the amount of the chain extender e2 charged is the amount of the 25% aqueous solution.
In addition, Examples 13 and 14 and Comparative Example 9 are examples and comparative examples using a non-self-emulsifying block polyisocyanate compound.

Table 5 shows the amount (g) of each raw material charged in the water-based polyurethane resin compositions of Examples 13 and 14 and Comparative Example 9. The (A) / (B) ratio in Table 5 is the mass ratio of the solid content of the component (A) and the component (B), and the value of the B-NCO content is a value with respect to the solid content.

The storage stability of the water-based polyurethane resin compositions of Examples 13 and 14 and Comparative Example 9 was tested by the following method.

The aqueous urethane resin composition was placed in a closed container and stored at 40 ° C., and the precipitation and separation were visually observed to evaluate the storage stability. The evaluation criteria are as follows. The results are shown in Table 6. A: Good storage stability for 1 month or more B: Precipitation / separation is observed in less than 2 weeks and storage stability is poor C: Precipitation / separation is observed in less than 1 week and storage stability is poor

Further, the water-based polyurethane resin compositions of Examples 13 and 14 and Comparative Example 9 were evaluated for moisture transparency and blocking resistance in the same manner as in the methods of Examples 1 to 12 and Comparative Examples 1 to 8.

According to the present invention, it is possible to provide an aqueous polyurethane resin having excellent adhesion to a polyester resin and blocking resistance, and further, by using a specific polyisocyanate compound in the production of the polyurethane resin, it is transparent. It is possible to provide an aqueous polyurethane resin having excellent properties. Further, according to the present invention, it is possible to provide an aqueous polyurethane resin having excellent storage stability.

Claims (7)

The component (A) contains a polyol compound, a polyisocyanate compound, and a urethane prepolymer which is a reaction product of an anionic group-introducing agent, and the component (B) contains a blocked polyisocyanate compound.
In the component (A), the polyol compound is a polycarbonate diol having a number average molecular weight of 500 to 5000, the polyisocyanate compound is an alicyclic diisocyanate, and the anionic group-introducing agent is a carboxyl group-containing polyol, which is a polyol compound. The reaction ratio of the polyisocyanate compound and the anionic group introducer is 1.1 to 2.5 as the molar ratio of the isocyanate group to the hydroxyl group, and the content of the anionic group is 0. 2 to 1.5 mmol / g
A water-based polyurethane resin composition, wherein the component (B) is a non-self-emulsifying blocked polyisocyanate compound, and the content of the blocked isocyanate group is 0.5 to 4 mmol / g with respect to the solid content. The aqueous polyurethane resin composition according to claim 1 , wherein a part or all of the isocyanate groups in the component (A) are blocked isocyanate groups blocked by a blocking agent. The aqueous polyurethane resin composition according to claim 1 or 2 , wherein the blocking agent for the blocked isocyanate group is an oxime-based blocking agent or a pyrazole-based blocking agent. An adhesive for a polyester resin comprising the water-based polyurethane resin composition according to any one of claims 1 to 3. An adhesive for an optical film comprising the water-based polyurethane resin composition according to any one of claims 1 to 3. The method for producing a water-based polyurethane resin composition according to any one of claims 1 to 3.
A step of reacting a polyol compound, a polyisocyanate compound and an anionic group-introducing agent to produce a urethane prepolymer, a step of mixing a urethane prepolymer and a non-self-emulsifying blocked polyisocyanate compound to form a mixture, and the mixture thereof. A method for producing an aqueous polyurethane resin composition, which comprises a step of dispersing in water. A step of applying the aqueous polyurethane resin composition according to any one of claims 1 to 3 to a base film, a step of drying the applied aqueous polyurethane resin composition, and 150 to the dried aqueous polyurethane resin composition. A method for producing an optical film, which comprises a step of thermosetting at 250 ° C.