JPWO2018061524A1 - Water-based polyurethane resin composition - Google Patents

Abstract

  As component (A), a urethane prepolymer which is a reaction product of a polyol compound, a polyisocyanate compound and an anionic group introducing agent, and as a component (B), a blocked polyisocyanate compound is contained, and the content of blocked isocyanate group is It is 0.5-4 mmol / g with respect to solid content, The water-based polyurethane resin composition characterized by the above-mentioned. The polyol compound is preferably a polycarbonate diol. Moreover, it is also preferable that the content of the anionic group in the component (A) is 0.2 to 1.5 mmol / g with respect to the amount of the urethane prepolymer of the component (A).

Description

  The present invention relates to a water-based polyurethane resin composition useful as a material of an easily adhesive layer of a polyester resin layer and a photocurable resin layer.

  In a backlight unit of a liquid crystal display, a prism sheet is used to improve luminance. The prism sheet has a prism pattern formed on the surface in order to condense the light emitted from the light guide toward the liquid crystal panel. The prism sheet is usually made of a photo-curing resin on which a prism pattern is formed and a polyester resin film such as polyethylene terephthalate (PET) resin, and the photo-curing having a prism pattern on a polyester resin film coated with an easy adhesion layer It is manufactured by adhering and bonding a system resin. Since the prism sheet is required to have transparency, heat resistance for maintaining performance at high temperature such as summer, and transparency under high humidity conditions, the adhesion layer of the prism sheet also has the same performance. There is a need. In addition, adhesion to a photocurable resin and a polyester resin, and blocking resistance are required for the easy adhesion layer. Although a polyurethane resin is used for the easily bonding layer, in recent years, a 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.

JP, 2011-140139, A WO 2013/014837 A1

However, water-based polyurethane resins have the disadvantage of being less adhesive to polyester resins than solvent-based or solvent-free polyurethane resins, and therefore, when water-based polyurethane resins are used, the adhesion surface is corona-treated. It is necessary to use a polyester resin film which has been surface-modified by plasma treatment, glow discharge treatment or the like. In addition, since the water-based polyurethane resin may be subjected to an environment exposed to high temperature such as storage and transportation under high temperature in summer, it is necessary to be excellent in storage stability. An object of the present invention is to provide an aqueous polyurethane resin excellent in adhesion to a resin and blocking resistance, and further to provide an aqueous polyurethane resin excellent in transparency. Another object of the present invention is to provide a water-based polyurethane resin excellent in storage stability.

As a result of intensive investigations to solve the above problems, the present inventors apply a water-based polyurethane resin having a specific amount of blocked isocyanate group and thermally cure it to facilitate adhesion with excellent adhesion to the polyester resin. We found that a layer was obtained and completed the present invention.
That is, the present invention comprises, as component (A), a urethane prepolymer which is a reaction product of a polyol compound, a polyisocyanate compound and an anionic group introducing agent, and a blocked polyisocyanate compound as component (B). It is an object of the present invention to provide an aqueous polyurethane resin composition characterized in that the content of the fluorinated isocyanate group is 0.5 to 4 mmol / g with respect to the solid content.

Moreover, this invention provides the adhesive agent for polyester resin films which consists of said water-based polyurethane resin composition, and the adhesive agent for optical films which consists of said water-based polyurethane resin composition.
Further, the present invention provides a process for producing a urethane prepolymer by reacting a polyol compound, a polyisocyanate compound and an anionic group introducing agent, a urethane prepolymer, and a non-self-emulsifiable blocked poly as the blocked polyisocyanate compound. A process for producing a waterborne polyurethane resin composition, comprising the steps of mixing isocyanate compounds to form a mixture, and dispersing the mixture in water.
In the present invention, the above-mentioned aqueous polyurethane resin composition is applied to a substrate film, the applied aqueous polyurethane resin composition is dried, and the dried aqueous polyurethane resin composition is thermally cured at 150 to 250 ° C. It is intended to provide a method of producing an optical film having a step.

[(A) component]
Component (A) in the aqueous 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 which is the component (A) is a polymer compound having a relatively low molecular weight, which is obtained by reacting the hydroxyl group of the polyol compound, the isocyanate group of the polyisocyanate compound, and the 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 described later. Therefore, the structure of the urethane prepolymer is largely different depending on the structure of the raw material used for producing the urethane prepolymer. For this reason, it is impossible at present to represent the structure of the above urethane prepolymer uniformly with a certain general formula, which is the common sense of the person skilled in the art. And, if the structure is not specified, the property of the substance determined according to it can not be easily understood, so it can not be expressed at all as a property. Therefore, in the present invention, the urethane prepolymer contained in the aqueous polyurethane resin composition can not but be defined by the expression "urethane prepolymer which is a reaction product of a polyol compound, a polyisocyanate compound and an anionic group introducing agent". Absent. That is, there is a circumstance in which "specifying the urethane prepolymer directly by its structure or characteristics at the time of filing" is impossible or almost impossible for the urethane prepolymer used in the present invention.

  Further, in the present invention, as described later, the urethane prepolymer may be a reaction product of four components of a polyol compound, a polyisocyanate compound, an anionic group introducing agent, and a blocking agent. When these four components are reacted, the blocking agent blocks part or all of the polyisocyanate groups in the reactant urethane prepolymer. Therefore, the difference between the reactant of the four components and the reactant of the three components of the polyol compound, the polyisocyanate compound and the anionic group introducing agent is that the isocyanate group is blocked by the blocking agent or not It is only a difference, there is no essential difference in the other configurations. Since the other configurations are the same, the same effect as in the case of using the reactants of three components is exhibited even when using the reactant of four components as the component (A). Therefore, the reaction product of the four components of the polyol compound, the polyisocyanate compound, the anionic group introducing agent, 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.

  As the polyester polyol, a compound obtained by esterification reaction of 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, γ-valerolactone, and the like Copolymerized polyesters thereof can be used.

  Examples of low molecular weight polyols used for polyester polyols 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, ne Pentyl glycol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,8-octanediol Aliphatic diols such as, aliphatic polyols such as glycerin, trimethylolpropane, ditrimethylolpropane, trimethylololpropane, pentaerythritol and the like; aliphatic cyclic structure-containing polyols such as 1,4-cyclohexanedimethanol and hydrogenated bisphenol A And bisphenol compounds such as bisphenol A, bisphenol F, bisphenol S, and alkylene oxide adducts thereof. From the viewpoint of light transmittance and flexibility, aliphatic polyols and aliphatic cyclic structure-containing polyols are preferable as low molecular weight polyols used in polyester polyols, and aliphatic diols are more preferable, and ethylene glycol 1,4 Butanediol 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 polycarboxylic acids used in polyester polyols include aliphatic polycarboxylic acids such as succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, dimer acid, etc .; 1,4-cyclohexanedicarboxylic acid Alicyclic polycarboxylic acids such as cyclohexanetricarboxylic acid; orthophthalic acid, isophthalic acid, terephthalic acid, 1,4-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, biphenyldicarboxylic acid, Aromatic polycarboxylic acids such as trimellitic acid and pyromellitic acid can be mentioned. Polycarboxylic acids can be used even if they are anhydrides or ester derivatives. The polycarboxylic acid used for the polyester polyol is preferably an aliphatic polycarboxylic acid, more preferably an aliphatic dicarboxylic acid, still more preferably adipic acid and sebacic acid, from the viewpoint of light transmittance and flexibility. The polycarboxylic acids can be used alone or in combination of two or more.

  As said polycarbonate diol, what is obtained by making a carbonate and / or a phosgene and a polyol react is mentioned. Examples of the carbonic ester include dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, ethylene carbonate, propylene carbonate, butylene carbonate, diphenyl carbonate, dinaphthyl carbonate, phenyl naphthyl carbonate and the like.

  Examples of polyols used for polycarbonate diols 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, neo-pinch Glycol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,8-octanediol, etc. Aliphatic diols; aliphatic cyclic structure-containing diols such as 1,4-cyclohexanedimethanol, hydrogenated bisphenol A; and aromatic dihydroxy compounds such as hydroquinone, resorcinol, bisphenol A, bisphenol F, 4,4'-biphenol; Polyether polyols such as polyethylene glycol, polypropylene glycol and polytetramethylene glycol; and polyester polyols such as polyhexamethylene adipate, polyhexamethylene succinate and polycaprolactone. The polyol used for the polycarbonate diol is preferably an aliphatic diol from the viewpoint of light transmittance and flexibility, more preferably 1,4-butanediol and 1,6-hexanediol, and 1,6-hexanediol. More preferable.

  As said polyether polyol, what carried out addition polymerization of the alkylene oxide can be used by using 1 type, or 2 or more types of a compound which has 2 or more of active hydrogen atoms as an initiator.

  As an initiator of polyether polyol, for example, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 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-1,8-octanediol, glycerin, diglycerin, trimethylolpropane, ditrimethylolpropane, tritrimethylolpropane, 1,2,6-hexanetriol, triethanolamine, triisopropanolamine, pentaerythritol, Dipentaerythritol, sorbitol, sucrose, ethylenediamine, N-ethyldiethylenetriamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,2-diaminobutane, 1,3-diaminobutane, 1,4-diaminobutane, Diethylene triamine, phosphoric acid, acidic phosphoric acid ester etc. are mentioned.

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

  The low molecular weight polyols having a number average molecular weight of less than 200 include, for example, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, diethylene glycol, 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, 3,5-heptanediol, 1,8-octanediol, 2-methyl-1,8-octanedio Aliphatic diols such as 1,9-nonanediol; cycloaliphatic diols such as cyclohexanedimethanol and cyclohexanediol; trivalents such as trimethylolethane, trimethylolpropane, hexitols, pentitols, glycerin and pentaerythritol The above polyols etc. are mentioned.

  The polyol compound used for the component (A) is preferably a polycarbonate diol from the viewpoint of heat resistance and light transmittance, preferably an aliphatic diol-derived polycarbonate diol, and particularly preferably a 1,6-hexanediol-derived polycarbonate diol .

  The number average molecular weight of the polyol compound is preferably 500 to 5,000, more preferably 600 to 3,000, and most preferably 700 to 2,000. In addition, as a polyol compound, it can also be used combining two or more types of polyol compounds from which a number average molecular weight differs. The number average molecular weight of the polyol compound can be measured, for example, by gel permeation chromatography (GPC).

  Examples of polyisocyanate compounds used for the component (A) include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, diphenylmethane-4,4'-diisocyanate, p-phenylene diisocyanate, xylylene diisocyanate, Aromatic diisocyanates such as 1,5-naphthalene diisocyanate, 3,3'-dimethyl diphenyl-4,4'-diisocyanate, dianisidine diisocyanate, tetramethyl xylylene diisocyanate; isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, Alicyclic diisocyanates such as trans-1,4-cyclohexyl diisocyanate and norbornene diisocyanate; 1,4-tetramethylene diisocyanate, 1,6-hexene Methylene 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-1,6-hexamethylene diisocyanate, 2,4-dimethyl-1,8-octamethylene diisocyanate, 5-methyl-1,9- Aliphatic diisocyanates such as nonamethylene diisocyanate, lysine diisocyanate, lysine methyl ester diisocyanate and the like can be mentioned.

  Further, as the polyisocyanate compound, isocyanurate trimerization of the above-mentioned diisocyanate, trimethylolpropane adduct of the above-mentioned diisocyanate, biuret trimerization of the above-mentioned diisocyanate, allophanate of the above-mentioned diisocyanate, triphenylmethane triisocyanate, 1-methylbenzene Trifunctional or higher isocyanates such as -2,4,6-triisocyanate, dimethyltriphenylmethane tetraisocyanate, 1,5,11-undecamethylenediisocyanate, and 2,4,6-toluene isocyanate are also included.

  The polyisocyanate compound used for the component (A) is preferably an alicyclic diisocyanate or an aliphatic diisocyanate from the viewpoint of light transmittance, heat resistance and adhesiveness, more preferably an alicyclic diisocyanate, and dicyclohexylmethane-4. , 4'-diisocyanate and isophorone diisocyanate are more preferred, and dicyclohexylmethane-4,4'-diisocyanate is most preferred.

  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. The anionic group introducing agent preferably has a functional group capable of reacting with a polyol compound or a polyisocyanate compound. As such a functional group, a hydroxyl group is mentioned, for example. As the anionic group introducing agent used for the component (A), for example, polyols containing a carboxyl group such as dimethylol propionic acid, dimethylol butanoic acid, dimethylol butyric acid, and dimethylol valeric acid; 1,4-butanediol Polyols containing a sulfonic acid group such as -2-sulfonic acid can be mentioned. From the viewpoint of heat resistance and industrial availability, polyols containing a carboxyl group are preferred, and dimethylol propionic acid is more preferred.

  When 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 when it is too large, the heat resistance may decrease, so (A) The content of anionic groups in the component is preferably 0.2 to 1.5 mmol / g, preferably 0.3 to 1.2 mmol / g, relative to the amount of the urethane prepolymer of component (A). Is more preferred, and most preferably 0.4 to 1.0 mmol / g. The content of anionic group (unit: mmol / g) can be calculated from the acid value (unit: mg KOH / 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 as referred to herein is a molar amount relative 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 neutralizing agent in the urethane prepolymer is not included in the above total amount. In addition, the acid value of the above-mentioned (A) component is a theoretical value calculated | required from the compounding quantity of the reaction component of the urethane prepolymer which is (A) component. When the urethane prepolymer is a reaction product of a polyol compound, a polyisocyanate compound and an anionic group introducing agent, the amount of the urethane prepolymer is the total amount of the polyol compound, the polyisocyanate compound and the anionic group introducing agent It is. When the urethane prepolymer is a reaction product of a polyol compound, a polyisocyanate compound, an anionic group introducing agent, and a blocking agent, the amount of the urethane prepolymer is a polyol compound, a polyisocyanate compound, an anion It is the total amount of the reactive group introducing agent and the blocking agent.

  In the present invention, the molar ratio of isocyanate group to hydroxyl group is called 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. In general, the terminal group of the urethane prepolymer is an isocyanate group when the NCO index in the preparation of the urethane prepolymer is more than 1 and is a hydroxyl group when the NCO index is less than 1. The terminal group of the urethane prepolymer is preferably an isocyanate group rather than a hydroxyl group, since the dispersibility in water is high and the polymerization by chain elongation is also easy, and thus the NCO index is preferably larger than 1.

  However, even if the NCO index is greater than 1, if it is very close to 1, a urethane prepolymer having relatively high molecular weight but poor dispersibility in water is easily obtained, and the NCO index is too high. If it is large, a large amount of carbon dioxide is generated by the reaction of the remaining isocyanate groups with water in the step of dispersing in water to cause rapid foaming, which may cause problems in production, and the resulting aqueous polyurethane composition There is also a risk that the adhesion may be reduced. 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 most preferred. 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 urethanation reaction to proceed smoothly. As such a catalyst, for example, 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 Propylenetriamine, 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'-dimethylpi Lazine, dimethylcyclohexylamine, N-methylmorpholine, N-ethylmorpholine, bis (2-dimethylaminoethyl) ether, N, N-dimethyllaurylamine, 1-methylimidazole, 1,2-dimethylimidazole, 1-isobutyl- Tertiary amines such as 2-methylimidazole and 1-dimethylaminopropylimidazole; tetraalkyl ammonium halides such as tetramethyl ammonium chloride; tetraalkyl ammonium hydroxides such as tetramethyl ammonium hydroxide; tetramethyl ammonium 2- Quaternary ammonium salts such as tetraalkyl ammonium organic acid salts such as ethyl hexanoate; stanas diacetate, stanas dioctoate, stanas dioleate, stanas dilaurate, dibutyric acid Tin oxide, dibutyl tin diacetate, dibutyltin dilaurate, dibutyltin dichloride, dioctyltin dilaurate, lead octanoate, lead naphthenate, nickel naphthenate, organic metal catalysts such as cobalt naphthenate, and the like. Among these catalysts, an organic metal catalyst is preferable, and dibutyltin dilaurate or dioctyltin dilaurate is more preferable because the reactivity is good and yellowing of the obtained polyurethane resin is small. 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, and 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. .

  It is preferable that the isocyanate group of (A) component in the water-based polyurethane resin composition of this invention is the blocked isocyanate group by which the one part or all was blocked with the blocking agent from the adhesive property improving. Examples of blocking agents include phenol-based blocking agents such as phenol, cresol, xylenol, chlorophenol and ethylphenol; and lactam-based blocking agents such as ε-caprolactam, δ-valerolactam, γ-butyrolactam and β-butyrolactam Active methylene-based blocking agents such as ethyl acetoacetate, 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; formaldoxime, acetoaldoxime, aceto Shim, oxime-based blocking agents such as methyl ethyl ketoxime, diacetyl monoxime, cyclohexane oxime; mercaptan-based blocking agents such as butyl mercaptan, hexyl mercaptan, t-butyl mercaptan, thiophenol, methylthiophenol, ethyl thiophenol; acetic acid amide, Amide-based blocking agents such as benzamide; imide-based blocking agents such as succinimide and maleimide; pyrazole, 3,5-dimethylpyrazole, 4-benzyl-3,5-dimethylpyrazole, 4-nitro-3, Pyrazole based blocking agents such as 5-dimethylpyrazole, 4-bromo-3,5-dimethylpyrazole and 3-methyl-5-phenylpyrazole; and imidazole based blocking agents such as 2-ethylimidazole. An oxime-based blocking agent and a pyrazole-based blocking agent are preferable, and the methyl ethyl keto is preferable because the dissociation 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 handling is easy. Oxime and 3,5-dimethylpyrazole are more preferred. When the content of the blocked isocyanate group in the component (A) is too small, a sufficient adhesion improvement effect can not be obtained, and when all the isocyanate groups are converted to the blocked isocyanate group, the component (A) can not be obtained. As the molecular weight does not become high in the aqueous dispersion step described later and the adhesiveness is rather reduced, the content of the blocked isocyanate group in the component (A) corresponds to 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%, and more preferably 15 to 30 mol%. When the content of the anionic group in the component (A) is calculated, the content of the anionic group is a molar amount relative to the total amount of the mass of the structural site derived from the polyol compound, the polyisocyanate compound and the anionic group introducing agent 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 and calculated.

  It is preferable that the anionic group of the component (A) be neutralized with an anionic group neutralizing agent, because the water dispersibility is improved. Examples of the anionic group neutralizing agent include trialkylamines such as trimethylamine, triethylamine and tributylamine; and basic compounds such as ammonia, trimethyl ammonium hydroxide, sodium hydroxide, potassium hydroxide and lithium hydroxide. When the anionic group neutralizing agent remains in the easily adhesive layer of the aqueous polyurethane resin composition of the present invention, the light resistance of the easily adhesive layer may be adversely affected. Therefore, as the anionic group neutralizing agent, it is easy by heat. The compound which dissociates and volatilizes into is preferable, and trimethylamine and a triethylamine are preferable.

  If the amount of the anionic group neutralizer used is too small, the water dispersibility of the component (A) will not be sufficiently improved, and if too large, the light resistance of the adhesive layer may be adversely affected. 0.5-2.0 equivalent is preferable with respect to 1 equivalent of anionic group, and, as for the usage-amount of group neutralization agent, 0.8-1.5 equivalent is more preferable.

  The component (A) is preferably polymerized with a chain extender because durability and adhesion are improved. The chain extender can react with the isocyanate group of the urethane prepolymer dispersed in water to polymerize the component (A), as described later.

  Examples of chain extenders include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, diethylene glycol, 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, 3,5-heptanediol, 1 Aliphatic compounds such as 8-octanediol, 2-methyl-1, 8-octanediol and 1,9-nonanediol Cycloaliphatic diols such as cyclohexanedimethanol, cyclohexanediol; low molecular weight diamines such as ethylenediamine, propylenediamine, hexamethylenediamine, tolylenediamine, piperazine, 2-methylpiperazine; diethylenetriamine, triethylenetetramine, tetraethylene Polyalkylene polyamines such as pentamine; Alkanolamines such as monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, 2- (2-aminoethylamino) ethanol and the like; polyoxypropylene diamine , Polyether diamines such as polyoxyethylene diamine; mensene diamine, isophorone diamine, norbornene diamine Aminoethylaminoethanol, bis (4-amino-3-methyldicyclohexyl) methane, diaminodicyclohexylmethane, bis (aminomethyl) cyclohexane, 3,9-bis (3-aminopropyl) -2,4,8,10-tetra Alicyclic diamines such as oxaspiro (5,5) undecane; m-xylenediamine, α- (m / p-aminophenyl) ethylamine, m-phenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, diaminodimethyldiphenylmethane, diamino Polyamines of aromatic diamines such as diethyldiphenylmethane, dimethylthiotoluenediamine, diethyltoluenediamine, α, α'-bis (4-aminophenyl) -p-diisopropylbenzene; succinic acid dihydrazide, adipic acid dihydrate Dorazide, sebacic acid dihydrazide, phthalic acid dihydrazide, 1,6-hexamethylene bis (N, N-dimethylsemicarbazide), 1,1,1 ′, 1′-tetramethyl-4,4 ′-(methylene-di-para) Hydrazides such as -phenylene) 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 an isocyanate group is not always rapid.

  As chain extenders, low molecular weight diamines, alkanolamines, polyalkyleneamines, hydrazides and hydrated hydrazine are preferable because they are easy to react and industrially available, ethylenediamine, monoethanol Amines are more preferred. The amount of the chain extender used is such that the amount of the group capable of reacting with the isocyanate group of the chain extender is 0.01 to 1 in molar ratio with respect to the isocyanate group of the urethane prepolymer (excluding the blocked isocyanate group). It is preferably 0.

[(B) component]
The component (B) in the aqueous polyurethane resin composition of the present invention is a blocked polyisocyanate compound. In the water-based polyurethane resin composition, a self-emulsifying blocked polyisocyanate compound and a forced emulsifying blocked polyisocyanate compound are often used because of their excellent dispersibility in water. In the present invention, a self-emulsifiable blocked polyisocyanate compound is a blocked polyisocyanate compound which has the compound itself with emulsifying and dispersing properties 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-self-emulsifying blocked polyisocyanate compound dispersed in water by a surfactant. The non-self-emulsifying blocked polyisocyanate compound refers to a blocked polyisocyanate compound which is not dispersed in water by itself. In addition, in the case of a self-emulsifiable blocked polyisocyanate compound, in order to impart self-emulsifiability, a polyethylene glycol chain which is a hydrophilic group is often introduced into the molecule. When a forced emulsifying blocked polyisocyanate compound or a self emulsifying blocked polyisocyanate compound is used, the surfactant of the forced emulsifying blocked polyisocyanate compound or the polyethylene glycol chain of the self emulsifying blocked polyisocyanate compound is A non-self-emulsifiable blocked polyisocyanate compound is preferable as the component (B) in the present invention because it may adversely affect the transparency of the adhesion layer in a high humidity atmosphere.

  Examples of the non-emulsifiable blocked polyisocyanate compound include a compound obtained by blocking the isocyanate group of a diisocyanate compound with a blocking agent, and a compound obtained by blocking an isocyanate group of a trifunctional or higher polyisocyanate compound with a blocking agent. From the viewpoint of adhesion, compounds in which the isocyanate group of the trifunctional or higher functional polyisocyanate compound is blocked with a blocking agent are preferable. Examples of such polyisocyanate compounds include isocyanurate trimers of diisocyanate exemplified by the polyisocyanate compound of component (A), trimethylolpropane adduct of diisocyanate, biuret trimer of diisocyanate, allophanate of diisocyanate, triphenyl Trifunctional compounds such as methanetriisocyanate, 1-methylbenzene-2,4,6-triisocyanate, dimethyltriphenylmethanetetraisocyanate, 1,5,11-undecamethylenediisocyanate, 2,4,6-toluentisocyanate The above isocyanate etc. are mentioned. Moreover, what trivalent or more than trifunctional polyisocyanate compound was made to connect with a polyol compound may be used. Examples of the blocking agent of the non-emulsifiable blocked polyisocyanate compound include the compounds exemplified as the blocking agent of the component (A), and the separation temperature of the blocking agent from the blocked isocyanate group is that of the urethane resin composition. Since the curing temperature (described later) is somewhat lower and handling is easy, oxime-based blocking agents and pyrazole-based blocking agents are preferable, and methyl ethyl ketoxime and 3,5-dimethylpyrazole are more preferable. Particularly preferred as the component (B), isocyanurate trimers of hexamethylene diisocyanate blocked with methyl ethyl ketoxime, isocyanurate trimers of hexamethylene diisocyanate blocked with 3,5-dimethylpyrazole, The isocyanurate trimers of hexamethylene diisocyanate are linked with polytetramethylene glycol and blocked with methyl ethyl ketoxime, and the isocyanurate trimers of hexamethylene diisocyanate are linked with polytetramethylene glycol and blocked with 3,5-dimethylpyrazole. And the like.

  Although there is no restriction | limiting in particular about the weight average molecular weight of the block forming polyisocyanate compound of (B) component used for the water-based polyurethane resin of this invention, It is preferable that it is 50000 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 is increased and the handling property is deteriorated. The weight average molecular weight of the blocked polyisocyanate compound can be measured, for example, by gel permeation chromatography (GPC).

  In the water-based polyurethane resin composition of the present invention, the content of blocked isocyanate groups is 0.5 to 4 mmol / g based on the solid content. When the content of the blocked isocyanate group is less than 0.5 mmol / g, the adhesion to the substrate is insufficient, and when it exceeds 4 mmol / g, the flexibility of the easily bonding layer is lowered or relatively The content of the component B) may be increased, and the dispersion stability of the component (B) may be reduced. The content of the blocked isocyanate group is preferably 0.7 mmol / g or more, more preferably 0.9 mmol / g or more, and more preferably 1.0 mmol / g or more with respect to the solid content. In addition, 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, and still more preferably 2 mmol / g or less based on the solid content. And 1.9 mmol / g or less is more preferable, 1.8 mmol / g or less is particularly preferable, and 1.7 mmol / g or less is most preferable. In the present invention, solid content refers to components other than volatile components such as water in the composition, organic solvent, etc. For example, it is calculated from 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 based on the solid content, If the amount of component (A) is too small, the dispersion stability of component (B) decreases, so the content of component (A) as a solid is the total amount of components (A) and (B) as a solid. It is preferably at least 20 parts by weight, more preferably at least 25 parts by weight, per 100 parts by weight.

  The smaller the amount of water in the water-based polyurethane resin composition of the present invention, the relatively more the amount of the active ingredient becomes and the more preferable it is. However, if the amount is too small, the dispersion stability decreases, so the water-based polyurethane resin composition of the present invention 60 to 1000 parts by mass is preferable, 100 to 400 parts by mass is more preferable, and 150 to 250 parts by mass is most preferable with respect to 100 parts by mass of the solid content of the aqueous polyurethane resin composition of the present invention .

[Other additives]
A well-known additive can be added to the water-based polyurethane resin composition of this invention in the range which does not inhibit the effect of this invention. Such additives include, for example, crosslinking agents, various weathering agents (hindered amine light stabilizers, ultraviolet light absorbers and antioxidants), silane coupling agents that make the adhesion to the substrate particularly strong, colloidal silica or Inorganic colloidal sols such as colloidal alumina, tetraalkoxysilanes and condensation products thereof, chelating agents, epoxy compounds, pigments, dyes, film-forming aids, curing agents, external crosslinking agents, viscosity modifiers, leveling agents, antifoaming agents, coagulation Inhibitors, radical scavengers, heat resistance imparting agents, inorganic or organic fillers, plasticizers, lubricants, fluorine-based or siloxane-based antistatic agents, reinforcing agents, catalysts, thixotropic agents, waxes, anti-fogging agents Antimicrobial agents, antifungal agents, anticorrosive agents, and anticorrosive agents can be used.

  The said crosslinking agent can improve durability by introduce | transducing a crosslinked structure into the water-based polyurethane resin composition of this invention. Examples of the crosslinking agent include urea, melamine compounds, adducts of benzoguanamine and the like with formaldehyde, the above adducts, amino resins comprising alkyl ether compounds containing an alcohol unit having 1 to 6 carbon atoms, and the like; polyfunctional epoxy compounds; A polyfunctional isocyanate compound; a polyfunctional aziridine compound etc. are mentioned and a melamine compound is preferable from being excellent in the reactivity. Examples of the melamine compound include melamine, monomethylolmelamine, dimethylololmelamine, trimethylolmelamine, tetramethylolmelamine, pentamethylolmelamine, hexamethylolmelamine, methylated methylolmelamine, butylated methylolmelamine, melamine resin and the like. Melamine is preferred because it is inexpensive and has excellent dispersibility.

  Examples of the above-mentioned hindered amine light stabilizer include 1,6-bis (2,2,6,6-tetramethyl-4-piperidylamino) hexane / dibromoethane polycondensate, 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-tert-octylamino-s-triazine polycondensate, 1,5,8,12-tetrakis [2,4-bis (N-butyl-N- (2) 2,2,6,6-Tetramethyl-4-piperidyl) amino) -s-triazin-6-yl] -1,5,8,12-tetraazadodecane, 1,5,8,12-tetrakis [2, 2, 4-Bis (N-butyl-N (1,2,2,6,6-pentamethyl-4-piperidyl) amino) -s-triazin-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-triazin-6-ylaminoundecane, 1,6,11-tris [2,2, 4-bis (N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino) -s-triazin-6-ylaminoundecane and the like can be mentioned.

  Examples of the UV absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, and 5,5'-methylenebis (2-hydroxy-4-methoxybenzophenone). And the like) 2-hydroxybenzophenones such as 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy-5-tert-octylphenyl) benzotriazole, 2- (2-hydroxy-3, 5-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2-hydroxy-3-tert-butyl-5-methylphenyl) -5-chlorobenzotriazole, 2- (2-hydroxy-3,5) -Dicumylphenyl) benzotriazole, 2,2'-methylenebis (4- Octyl-6-benzotriazolylphenol), polyethylene glycol ester of 2- (2-hydroxy-3-tert-butyl-5-carboxyphenyl) benzotriazole, 2- [2-hydroxy-3- (2-acryloyloxy) Ethyl) -5-methylphenyl] benzotriazole, 2- [2-hydroxy-3- (2-methacryloyloxyethyl) -5-tert-butylphenyl] benzotriazole, 2- [2-hydroxy-3- (2-) Methacryloyloxyethyl) -5-tert-octylphenyl] benzotriazole, 2- [2-hydroxy-3- (2-methacryloyloxyethyl) -5-tert-butylphenyl] -5-chlorobenzotriazole, 2- [2 -Hydroxy-5- (2-methacryloyloxyethyl) phenyl] bene Zotriazole, 2- [2-hydroxy-3-tert-butyl-5- (2-methacryloyloxyethyl) phenyl] benzotriazole, 2- [2-hydroxy-3-tert-amyl-5- (2-methacryloyloxy) Ethyl) phenyl] benzotriazole, 2- [2-hydroxy-3-tert-butyl-5- (3-methacryloyloxypropyl) phenyl] -5-chlorobenzotriazole, 2- [2-hydroxy-4- (2-) Methacryloyloxymethyl) phenyl] benzotriazole, 2- [2-hydroxy-4- (3-methacryloyloxy-2-hydroxypropyl) phenyl] benzotriazole, 2- [2-hydroxy-4- (3-methacryloyloxypropyl) 2- (2-hydroxyphenyl) such as phenyl] benzotriazole B) 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- Hydroxy-4- (2-acryloyloxyethoxy) phenyl] -4,6-bis (4-methylphenyl) -1,3,5-triazine, 2- (2,4-dihydroxy-3-allylpheny) ) -4,6-Bis (2,4-dimethylphenyl) -1,3,5-triazine, 2,4,6-tris (2-hydroxy-3-methyl-4-hexyloxyphenyl) -1,3 2- (2-hydroxyphenyl) -4,6-diaryl-1,3,5-triazines such as 5-triazine; phenyl salicylate, resorcinol monobenzoate, 2,4-di-tert-butylphenyl-3, 5 -Di-tert-butyl-4-hydroxybenzoate, octyl (3,5-di-tert-butyl-4-hydroxy) benzoate, dodecyl (3,5-di-tert-butyl-4-hydroxy) benzoate, tetradecyl (3,5 -Di-tert-butyl-4-hydroxy) benzoate, hexadecyl (3,5-di-tert-butyl-4-hydroxy) benzoate, octadecyl (3,5-di-butyl) Benzoates such as 3-butyl-4-hydroxy) benzoate, behenyl (3,5- di-tert-butyl-4-hydroxy) benzoate; 2-ethyl-2 '-ethoxyoxanilide, 2-ethoxy-4'-dodecyl Substituted oxanilides such as oxanilide; Cyanoacrylates such as ethyl-.alpha.-cyano-.beta.,. Beta.-diphenyl acrylate, methyl-2-cyano-3-methyl-3- (p-methoxyphenyl) acrylate and the like Metal salts or metal chelates, such as salts or chelates of nickel or chromium are used.

  As said antioxidant, phosphorus type antioxidant, phenol type antioxidant, and sulfur type antioxidant can be used. As a phosphorus antioxidant, for example, triphenyl phosphite, tris (2,4-di-tert-butylphenyl) phosphite, tris (2,5-di-tert-butylphenyl) phosphite, tris (nonylphenyl) Phosphite, tris (dinonylphenyl) phosphite, tris (mono, di-mixed nonylphenyl) phosphite, diphenyl acid phosphite, 2,2′-methylenebis (4,6-di-tert-butylphenyl) octyl phosphite, Diphenyl decyl phosphite, diphenyl octyl phosphite, di (nonylphenyl) pentaerythritol diphosphite, phenyl diisodecyl phosphite, tributyl phosphite, tris (2-ethylhexyl) phosphite, tridecyl phosphite, trilauryl phosphite Dibutyl acid phosphite, dilauryl acid phosphite, trilauryl trithiophosphite, bis (neopentyl glycol) -1,4-cyclohexanedimethyl diphosphite, bis (2,4-di-tert-butylphenyl) pentaerythritol diphos Phyto, bis (2,5-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, bis (2,4-dicumyl) Phenyl) pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, tetra (mixed alkyl of C12 alkyl to C15 alkyl) -4,4'-isopropylidene diphenyl phosphite, bis [2,2'-methylene bis (4,4, 6-di Milphenyl)]-isopropylidene diphenyl phosphite, tetratridecyl-4,4'-butylidenebis (2-tert-butyl-5-methylphenol) diphosphite, hexa (tridecyl) -1,1,3-tris (2-) Methyl-5-tert-butyl-4-hydroxyphenyl) butane triphosphite, tetrakis (2,4-di-tert-butylphenyl) biphenylene diphosphonite, tris (2-[(2,4,7,9-tetrakis) Tert-Butyldibenzo [d, f] [1,3,2] dioxaphosphepin-6-yl) oxy] ethyl) amine, 9,10-dihydro-9-oxa-10-phosphaphenanthrene- 10-oxide, tris (2-[(2,4,8,10-tetrakis tert-butyl dibenzo [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] dioxaphosphepin-6-yl] oxy] propyl] phenol, and 2-butyl-2-ethylpropanediol-2,4,6-tri-tert-butylphenol mono Phosphites can be used.

  Examples of the above-mentioned phenolic antioxidants include 2,6-di-tert-butyl-p-cresol, 2,6-diphenyl-4-octadecyloxyphenol, stearyl (3,5-di-tert-butyl-4-4 Hydroxyphenyl) propionate, distearyl (3,5-di-tert-butyl-4-hydroxybenzyl) phosphonate, tridecyl 3,5-di-tert-butyl-4-hydroxybenzyl thioacetate, thiodiethylene bis [(3,5 -Di-tert-butyl-4-hydroxyphenyl) propionate], 4,4'-thiobis (6-tert-butyl-m-cresol), 2-octylthio-4,6-di (3,5-di-tert-butyl) -4-hydroxyphenoxy) -s-triazine, 2,2′-methylenebis (4-methyl-6-tert-butylphenol), bis [3,3 Bis (4-hydroxy-3-tert-butylphenyl) butyric acid] glycol ester, 4,4′-butylidenebis (2,6-di-tert-butylphenol), 4,4′-butylidenebis (6-tert-butyl- 3-Methylphenol), 2,2'-Ethylidenebis (4,6-di-tert-butylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, bis [2-tert-butyl-4-methyl-6- (2-hydroxy-3-tert-butyl-5-methylbenzyl) phenyl] terephthalate, 1,3,5-tris (2,6-dimethyl-3-hydroxyl -4-tert-butylbenzyl) isocyanurate, 1,3,5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 1,3,5-to Di- (3,5-di-tert-butyl-4-hydroxybenzyl) -2,4,6-trimethylbenzene, 1,3,5-tris [(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl Oxyethyl] isocyanurate, tetrakis [methylene-3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate] methane, 2-tert-butyl-4-methyl-6- (2-acro) Yloxy-3-tert-butyl-5-methylbenzyl) phenol, 3,9-bis [2- (3-tert-butyl-4-hydroxy-5-methylhydrocinnamoyloxy) -1,1-dimethylethyl ] -2,4,8,10-tetraoxaspiro [5.5] undecane, triethylene glycol bis [β- (3-tert-butyl-4-hydroxy-5-methylphenyl) ester Pioneto], and it can be used tocopherol.

  Examples of the sulfur-based antioxidant include dialkylthiodipropionates such as dilauryl, dimyristyl, myristyl stearyl, distearyl ester of thiodipropionic acid, and pentaerythritol tetra (β-dodecylmercaptopropionate). And β-alkylmercaptopropionic acid esters of polyols can be used.

The amount of the weathering agent (hindered amine light stabilizer, ultraviolet light absorber and antioxidant) used is preferably 0.001 to 10 parts by mass, more preferably 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 weathering agent is less than 0.001 parts by mass with respect to 100 parts by mass of the solid content, sufficient addition effects 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 properties of the coating film may be adversely affected.
Further, the total amount of other additives including the weathering 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 known additives are used, surfactants may be used as dispersants and emulsifiers. When the content of the surfactant in the aqueous polyurethane resin composition is high, the transparency of the easily adhesive layer in a high humidity atmosphere may be adversely affected. Therefore, the content of the surfactant in the aqueous polyurethane resin composition of the present invention is preferably 1 part by mass or less, and 0.2 parts by mass with respect to 100 parts by mass of the solid content of the aqueous polyurethane resin composition. It is more preferable that it is the following.

〔Production method〕
The aqueous polyurethane resin composition of the present invention is characterized by containing a blocked polyisocyanate compound as the component (B) and containing a blocked isocyanate group at a high concentration. When the component (B) is a self-emulsifiable blocked polyisocyanate compound or a forced emulsification type blocked polyisocyanate compound, even after the component (A) is dispersed in water, blending the component (B) can be carried out Although it is easy, when the component (B) is a non-self-emulsifying blocked polyisocyanate compound, it is difficult to blend the component (B) after dispersing the component (A) in water. Below, the manufacturing method in case (B) component is a non-self-emulsifying blocked polyisocyanate compound is demonstrated.

  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 optionally reacted by adding a catalyst and a crosslinking agent, and the urethane prepolymer of component (A) Manufacture. The preparation of the urethane prepolymer can be carried out by a conventional method, and the reaction temperature can be a reaction temperature of a usual urethanization, for example, 50 to 100 ° C., and does not react with isocyanate group to smoothly proceed the reaction. Inert solvents can also be used. The inert solvent used for the production is preferably an organic solvent having a high affinity for water, since it does not inhibit the water dispersibility of the urethane prepolymer, and examples thereof include 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, it can be reacted with charging the blocking agent simultaneously with the polyisocyanate compound etc. during the production of the urethane prepolymer, or A blocking agent can be charged and reacted halfway or after completion. The reaction temperature of the blocking agent varies depending on the blocking agent, but in the case of an oxime based blocking agent or a pyrazole based blocking agent, 50 to 100 ° C. is preferable.

  The non-self-emulsifying blocked polyisocyanate is difficult to disperse in water, so that 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 (A) component and the (B) component and then dispersing it in water, the (B) component, which has been difficult to disperse in water, can also be dispersed in water. It is considered that, since the component (A) functions as an emulsifier for the component (B), the component (B) can be dispersed because of its emulsifying property. As a method of dispersing in water, a prepolymer mixing method and a phase inversion method are preferable since the dispersibility in water is good. In the prepolymer mixing method, an anionic group neutralizing agent is added to the urethane prepolymer of component (A) and mixed, and then the mixture is poured into water and dispersed in water, and in the phase inversion method, the urethane of component (A) is Either add water containing an anionic group neutralizing agent to the prepolymer, or add an anionic group neutralizing agent to the urethane prepolymer of component (A) and mix, then add water to the mixture and disperse it in water In any method, the timing of mixing the component (A) and the component (B) is not particularly limited as long as the component (A) coexists with water, but neutralization of the anionic group to the urethane prepolymer is possible. When adding and mixing the agent, it is preferable to add and mix an anionic group neutralizing agent together with the component (B).

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

  When a chain extender is used, it is dissolved in water used to disperse the (A) component and the (B) component. When a chain extender is used, if the temperature of water is low, the reaction takes a long time, the production efficiency is lowered, and if it is too high, the reaction between isocyanate groups and water is accompanied by the generation of carbon dioxide as described above. Since the foaming phenomenon may occur, the temperature of water in the case of using a chain extender is preferably 20 to 75 ° C, and more preferably 30 to 65 ° C. In addition, as a method of determining the end point of the reaction in chain extension, a method of confirming the disappearance of the isocyanate group using IR (infrared spectrophotometer) is preferable because it is simple.

  When the above-mentioned other additives are blended, it is preferable to blend the water-soluble or water-dispersible additive after dispersing the (A) component and the (B) component in water, and it is non-water-soluble and non-water-dispersible It is preferable that the additive of (1) is mixed with the urethane prepolymer of the component (A) and then dispersed in water, as the component (B).

  In addition, when an organic solvent is used for manufacture of (A) component, although a water-based polyurethane resin composition contains an organic solvent, it is a water-based polyurethane resin composition from a viewpoint of safety | security, such as environmental pollution and occupational hygiene. The organic solvent in the substance is preferably removed by a method such as distillation under reduced pressure.

[Use]
Although the water-based polyurethane resin composition of the present invention is excellent in adhesion to a substrate, blocking resistance, transparency, heat resistance and the like, it can be used as various adhesives, but various optical films can be used. It can be suitably used as an easily adhesive layer. A film intended to transmit or reflect and absorb light and provide various effects is called an optical film. As an optical film, a reflective film, an antireflection film, an orientation film, a polarizing film, a polarizing layer protective film, a retardation film, a viewing angle improving film, a brightness improving film, an electromagnetic wave shielding film, a light shielding film, a specific frequency selective blocking film, optical Examples include low pass filters, lens filters, conductive films for touch panels, light diffusion films, antiglare films, prism sheets, and the like. As resin film substrates for optical films, polyester resins such as polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT) and polybutylene terephthalate (PBT) are generally used because they are excellent in transparency, flexibility and physical strength. used. The conventional water-based polyurethane resin composition used for the easily adhesive layer of the optical film has a poor adhesion to the polyester resin of the substrate and thus the surface of the substrate is corona treated. In some cases, the surface is reformed by plasma treatment, glow discharge treatment or the like. Since the water-based polyurethane resin composition of the present invention is excellent in adhesion to polyester resins, high adhesion to such non-surface-treated substrates is obtained, and an adhesive for polyester resins Above all, it can be suitably used as an easy-adhesion layer of an optical film which is required to have transparency and adhesion. The water-based polyurethane resin composition of the present invention is also excellent in adhesion to an acrylic resin, and therefore, an optical sheet using an acrylic resin, such as a polarizing film, a light diffusion film, a reflective film, a reflection film, an antireflection film, It is preferably used as an easy-adhesion layer such as a glare film or a prism sheet, and is preferably used as an easy-adhesion layer such as a prism sheet.

  The aqueous polyurethane resin composition of the present invention can be applied to a substrate, dried, and then heat treated to be cured to form an easily adhesive layer. The coating method of the aqueous polyurethane resin composition of the present invention is not particularly limited, and any known method can be used. For example, slit coater method such as curtain flow coater method and die coater method, knife coater method, roll coater method Etc. can be used.

  The coating film of the water-based polyurethane resin composition of the present invention is cured by heating to a temperature equal to or higher than the deviation temperature of the blocking agent. That is, by heating, the blocking agent is dissociated from the blocked isocyanate group to regenerate the active isocyanate group and react with the hydroxyl group or amino group to generate a urethane group or 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, the isocyanate group reacts with the urethane group or the urea group to form the allophanate group or the biuret group and crosslinks, and the generated groups improve the adhesion of the easy adhesion layer. Therefore, although the one where heating temperature is high is preferable, when heating temperature is too high, a base material and an easily bonding layer may thermally deteriorate. For this reason, 150-250 degreeC is preferable, as for the heating temperature of the coating film of the water-based polyurethane resin composition of this invention, 160-210 degreeC is still more preferable, and 170-190 degreeC is the most preferable. Although heating time changes with heating temperature, when heating temperature is 180 degreeC, 1 to 30 minutes become a standard. The heating method is not particularly limited, and, for example, known heating methods such as hot air heating, infrared heating, high frequency heating and the like can be applied.

Hereinafter, the present invention will be specifically described by way of examples.
In the following examples and the like, the blending ratio (%) means a mass-based ratio unless otherwise specified. Moreover, the raw material used by the following manufacture example, an Example, and a comparative example is as follows.

Polyol a1: Polycarbonate diol polyol a2 of number average molecular weight 2000: Polytetramethylene glycol monool a'1 of number average molecular weight 1000: polyethylene glycol monomethyl ether polyisocyanate b1 of number average molecular weight 550: Isophorone diisocyanate polyisocyanate b2: Dicyclohexylmethane- 4,4'-diisocyanate polyisocyanate b3: isocyanurate trimerization of hexamethylene diisocyanate (isocyanate content 21.8%)
Anionic group introducing agent c1: dimethylol propionic acid anionic group neutralizing agent d1: triethylamine chain extender e1: ethylene diamine chain extender e2: monoethanolamine blocking agent f1: methyl ethyl ketoxime blocking agent f2: 3,5,5- Dimethyl pyrazole MEK: methyl ethyl ketone

Preparation Example 1: Prepolymer A1
14. 313.9 g of polyol a1, 280.0 g of polyisocyanate b1, 80.8 g of anionic group introducing agent c1, 250 g of MEK, and 14. g in a glass reaction vessel having a stirrer, a cooling pipe, and a nitrogen introducing pipe. 4 g of blocking agent f1 was charged, reacted at 80 ° C. for 5 hours with stirring, and solvent-containing prepolymer A1 was produced. The content of anionic groups in the prepolymer A1 is 0.642 mmol / g, and the content of anionic groups when the solvent is removed is 0.875 mmol / g. Further, the content of blocked isocyanate groups (hereinafter also referred to as B-NCO) in prepolymer A1 is 0.177 mmol / g, and the content of blocked isocyanate groups relative to the solid content of prepolymer A1 is 0.241 mmol / g It is.

Preparation Examples 2 to 8: Prepolymers A2 to A8
A urethane prepolymer A2 to A8 was produced in the same manner as in Production Example 1 except that the amounts of the raw materials charged were changed as described in Table 1.
In addition, the numerical value of the preparation amount of each raw material in Table 1 is g number. Further, the values of the content of anionic group and B-NCO are the values for the solid content of the prepolymer at the top, and the values in () at the bottom are the values for the prepolymer containing a solvent.

Preparation 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, 250 g of MEK as a solvent in a glass reaction vessel having a stirrer, a cooling pipe and a nitrogen introducing pipe The mixture was charged and reacted at 80 ° C. for 5 hours with stirring 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 relative to solids is 3.47 mmol / g. In addition, blocked polyisocyanate B1 is a non-self-emulsifying blocked polyisocyanate compound.

Preparation Examples 10 to 11 and 13: Blocked Polyisocyanate B2, B3, B5
Operations similar to those of Production Example 8 were carried out except that the preparation amounts (g) of the respective raw materials were changed as described in Table 2, to produce blocked polyisocyanates B2, B3 and B5. 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 a nonionic surfactant (made by ADEKA, trade name: adecanol SP-12, HLB: 12.7), 45 g of water are treated with a homomixer to be blocked A blocked polyisocyanate B4, which is an emulsified dispersion of the polyisocyanate B1, was obtained. Blocked polyisocyanate B4 is a forced emulsification type blocked polyisocyanate compound.

  Table 2 shows the feed amounts (g) of each raw material of blocked polyisocyanates B1 to 5 and the content of B-NCO. In addition, the value of the content of B-NCO is a value with respect to solid content of blocked polyisocyanate, and the value in the upper part is a value in () of the lower part is a value containing a solvent.

Example 1
In a resin container, 56.35 g of prepolymer A1, 3.65 g of anionic group neutralizer d1 and 40 g of blocked polyisocyanate B1 were charged 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 prepolymer. In a glass reaction vessel having a stirrer, 150 g of water, 0.02 g of an antifoam (made by ADEKA Co., Ltd., trade name: Adenanate B-1016) are charged, and the mixture is stirred at 40 ° C. The mixture was added over a minute and further stirred at 40 ° C. for 30 minutes. After adding 0.224 g of a 25% by weight aqueous solution (0.056 g as a chain extender e1) of a chain extender e1 and stirring at 40 ° C. for 1 hour, MEK was removed under reduced pressure; 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 preparation amounts (g) of the respective raw materials were changed as described in Table 3, to obtain aqueous 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 as that of the anionic group introducing agent in the brepolymer, and the amount of the chain extenders e1 and e2 charged is the amount of a 25% aqueous solution. . Examples 2 to 10 and Comparative Examples 1 to 8 are all examples using non-self-emulsifying blocked polyisocyanate compounds.

[Example 11]
In a resin container, 46.95 g of the prepolymer A1 and 3.05 g of the anionic group neutralizer d1 were charged, and the mixture was stirred for 5 minutes to obtain a mixture. In a glass reaction vessel having a stirrer, 150 g of water, 0.02 g of an antifoam (made by ADEKA Co., Ltd., trade name: Adenanate B-1016) are charged, and the mixture is stirred at 40 ° C. After adding over a minute and further stirring at 40 ° C. for 30 minutes, 0.19 g of a 25% by weight aqueous solution of a chain extender e1 was added and stirred at 40 ° C. for 1 hour. To this, 50 g of blocked polyisocyanate B3 was added and stirred at 40 ° C. for 1 hour for dispersion, and then MEK was removed under reduced pressure to obtain an aqueous polyurethane resin composition of Example 11. Example 11 is an example using a self-emulsifying blocked polyisocyanate compound.

[Example 12]
In a resin container, 56.35 g of prepolymer A1 and 3.65 g of anionic group neutralizer d1 were charged and stirred for 5 minutes to obtain a mixture. In a glass reaction vessel having a stirrer, 120 g of water, 0.02 g of an antifoam (made by ADEKA Co., Ltd., trade name: Adenanate B-1016), and 70 g of blocked polyisocyanate B4 are charged, and at 40 ° C. The mixture was added over 2 minutes while stirring. After further stirring for 30 minutes at 40 ° C., 0.23 g of a 25% by weight aqueous solution of a chain extender e1 was added and stirred for 1 hour at 40 ° C. Thereafter, MEK was removed under reduced pressure to obtain an aqueous polyurethane resin composition of Example 12. Example 12 is an example using a forced emulsifying type blocked polyisocyanate compound.

  In Table 3, the preparation amount (g) of each raw material of the water-based polyurethane resin composition of Examples 1-12 and Comparative Examples 1-8 is shown. In addition, (A) / (B) ratio of Table 3 is mass ratio of solid content of (A) component and (B) component, and the value of the content of B-NCO is a value with respect to solid content.

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

Test specimen A: A water-based polyurethane resin composition is applied to a commercially available PET film (thickness 20 μm, non-corona treated, surface average water contact angle 70 °) such that the thickness of the coating after drying is about 1 μm, After air drying at 25 ° C., the test piece A was prepared by heating at 180 ° C. for 10 minutes.
Specimen B: A commercially available PET film is corona-treated with a corona treatment device until the average water contact angle on the surface is 28-32 °, and the thickness of the coating film after drying is about 1 μm. The aqueous 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 specimen C: A commercially available acrylic photo-curable resin (made by ADEKA, trade name: Adekaoptomer HC-211 so that the thickness becomes about 3 μm on the surface coated with the urethane resin of the test specimen B -9) was applied and dried at 80 ° C., and then cured using a metal halide lamp under the conditions of 600 mW / cm ² intensity and 500 mJ / cm ² integrated light quantity 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. From the presence or absence of separation, storage stability was evaluated based on the following evaluation criteria. In addition, the thing with poor storage stability did not test the following.
(Evaluation criteria)
○: No separation was observed, storage stability was good ×: Separation was observed, storage stability was poor

<Adhesiveness test method>
Test according to JIS K 5600-5-6 (General test method for paints-Part 5: Mechanical properties of coating-Section 6: Adhesion (cross-cut method)) using a cutter guide with a gap of 1 mm A piece of urethane-based cured film was cut into 100 squares. After adhering the adhesive tape to the cut cured film, the adhesive tape was peeled off at an angle of about 60 ° to the peeling direction. After performing the adhesion tape peeling and peeling operations three times on the same test piece, the number of squares without peeling was counted. The greater the number of squares without peeling, the higher the adhesion.

<Humidity-resistant transparency test method>
After leaving test specimen A in a constant temperature and humidity chamber at 80 ° C. and 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) did. The value obtained by subtracting the haze value of the commercial PET film used for the preparation of the test piece A from this value was taken as ΔH. The larger the ΔH, the lower the transparency of the urethane-based cured film, or the lower the transparency by the moisture resistance transparency test.

<Method for testing blocking resistance>
Using two pieces of test specimen A, the urethane-based cured film surfaces are stacked, sandwiched between two glass plates, and a load of 10 kgf / cm ² is applied to a thermostatic chamber with a temperature of 60 ° C and a relative humidity of 80%. Let stand for 24 hours. Thereafter, the overlapping test pieces were peeled off, and the ratio (%) of the area of the broken surface to the area of the superposed 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 procedures as in Example 1 were carried out except that the preparation amounts (g) of the respective raw materials were changed as described 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 as that of the anionic group introducing agent in the prepolymer, and the amount of the chain extender e2 charged is the amount of a 25% aqueous solution.
Examples 13 and 14 and Comparative Example 9 are all Examples and Comparative Examples in which a non-self-emulsifying block polyisocyanate compound was used.

  Table 5 shows the amounts (g) of the raw materials of the water-based polyurethane resin compositions of Examples 13 and 14 and Comparative Example 9. In addition, (A) / (B) ratio of Table 5 is mass ratio of solid content of (A) component and (B) component, and the value of the content of B-NCO is a value with respect to solid content.

  The storage stability of the aqueous 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, stored at 40 ° C., and precipitation and separation were visually observed to evaluate storage stability. The evaluation criteria are as follows. The results are shown in Table 6. A: 1 month or more, good storage stability B: Less than 2 weeks, precipitation and separation are observed, storage stability is poor C: less than 1 week, precipitation and separation is observed, storage stability is poor

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

  According to the present invention, it is possible to provide a water-based polyurethane resin excellent in adhesion to a polyester resin and blocking resistance, and furthermore, by using a specific polyisocyanate compound in the production of the polyurethane resin, it is transparent. It is possible to provide a water-based polyurethane resin which is also excellent in properties. Further, according to the present invention, a water-based polyurethane resin excellent in storage stability can be provided.

Claims (10)

  As component (A), a urethane prepolymer which is a reaction product of a polyol compound, a polyisocyanate compound and an anionic group introducing agent, and as a component (B), a blocked polyisocyanate compound is contained, and the content of blocked isocyanate group is It is 0.5-4 mmol / g with respect to solid content, The water-based polyurethane resin composition characterized by the above-mentioned.   The water based polyurethane resin composition according to claim 1, wherein the polyol compound is a polycarbonate diol.   The water-based polyurethane resin composition according to claim 1 or 2, wherein the content of the anionic group in the component (A) is 0.2 to 1.5 mmol / g with respect to the amount of the urethane prepolymer of the component (A). .   The water-based polyurethane resin composition according to any one of claims 1 to 3, wherein part or all of the isocyanate groups in the component (A) is a blocked isocyanate group blocked with a blocking agent.   The water-based polyurethane resin composition according to any one of claims 1 to 4, wherein the component (B) is a non-self-emulsifying blocked polyisocyanate compound.   The aqueous polyurethane resin composition according to any one of claims 1 to 5, wherein the blocking agent for the blocked isocyanate group is an oxime-based blocking agent or a pyrazole-based blocking agent.   The adhesive agent for polyester resins which consists of a water-based polyurethane resin composition of any one of Claims 1-6.   The adhesive for optical films which consists of a water-based polyurethane resin composition of any one of Claims 1-6. It is a manufacturing method of the water-based polyurethane resin composition according to claim 5,
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 The manufacturing method of the water-based polyurethane resin composition which has the process of disperse | distributing to water.   The process of apply | coating the water-based polyurethane resin composition of any one of Claims 1-6 to a base film, the process of drying the apply | coated water-based polyurethane resin composition, and the dried water-based polyurethane resin composition 150-150 A method for producing an optical film comprising the step of heat curing at 250 ° C.