WO2018061524A1

WO2018061524A1 - Aqueous polyurethane resin composition

Info

Publication number: WO2018061524A1
Application number: PCT/JP2017/029874
Authority: WO
Inventors: 剛伊本; 竜巳小坂
Original assignee: 株式会社Adeka
Priority date: 2016-09-27
Filing date: 2017-08-22
Publication date: 2018-04-05
Also published as: TW201819446A; CN109415482B; CN109415482A; JPWO2018061524A1; KR20190055780A; TWI742149B; KR102385074B1; JP6946314B2

Abstract

Provided is an aqueous polyurethane resin composition characterized by including, as component (A), an urethane prepolymer which is a reactant of a polyol compound, a polyisocyanate compound, and an anionic group introducing agent, and as component (B), a blocked polyisocyanate compound, wherein the content of blocked isocyanate groups is 0.5 to 4 mmol/g based on the solid content. The polyol compound is preferably a polycarbonate diol. The content of the anionic groups in the component (A) is preferably 0.2 to 1.5 mmol/g based on the amount of the urethane prepolymer of the component (A).

Description

Water-based polyurethane resin composition

The present invention relates to a water-based polyurethane resin composition useful as a material for an easy adhesion layer of 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 luminance. The prism sheet has a prism pattern formed on the surface in order to condense light emitted from the light guide toward the liquid crystal panel. A prism sheet is usually composed of a photo-curing resin having a prism pattern formed thereon 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. Manufactured by adhering and adhering resin. Since prism sheets are required to have transparency, heat resistance to maintain performance at high temperatures such as in summer, and transparency under high humidity conditions, the easily adhesive layer of the prism sheet has equivalent performance. There is a need. In addition, the easy-adhesion layer is required to have adhesiveness with a photocurable resin and a polyester resin and blocking resistance. Polyurethane resins are used for the easy-adhesion layer, but recently, water-based polyurethane resins (for example, see Patent Documents 1 and 2) have been studied from the viewpoint of safety such as environmental pollution and occupational health.

JP 2011-140139 A WO2013 / 014837A1

However, water-based polyurethane resins have the disadvantage of poor adhesion to polyester resins compared to solvent-based or solvent-free polyurethane resins. Therefore, when water-based polyurethane resins are used, the adhesive surface is corona-treated. It was necessary to use a polyester resin film whose surface was modified by plasma treatment, glow discharge treatment or the like. In addition, since the water-based polyurethane resin may be placed in an environment exposed to high temperatures, such as storage and transportation at high temperatures in summer, it is necessary to have excellent storage stability. It is to provide a water-based polyurethane resin excellent in adhesion to resin and blocking resistance, and further to provide a water-based polyurethane resin excellent in transparency. Moreover, the subject of this invention is providing the water-based polyurethane resin excellent in storage stability.

As a result of intensive studies to solve the above-mentioned problems, the present inventors applied a water-based polyurethane resin having a specific amount of a blocked isocyanate group and thermally cured, thereby easily adhering to the polyester resin. It was found that a layer was obtained and the present invention was completed.
That is, the present invention comprises a urethane prepolymer which is a reaction product of a polyol compound, a polyisocyanate compound and an anionic group introducing agent as the component (A), and a blocked polyisocyanate compound as the component (B), An aqueous polyurethane resin composition is characterized in that the content of sulfonated isocyanate groups is 0.5 to 4 mmol / g based on the solid content.

Moreover, this invention provides the adhesive agent for polyester resin films which consists of the said aqueous polyurethane resin composition, and the adhesive agent for optical films which consists of the said aqueous polyurethane resin composition.
The present invention also 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-emulsifying blocked poly (polyethylene) as the blocked polyisocyanate compound. The present invention provides a method for producing a water-based polyurethane resin composition, which comprises a step of mixing an isocyanate compound into a mixture and a step of dispersing the mixture in water.
The present invention also includes a step of applying the aqueous polyurethane resin composition to a base film, a step of drying the applied aqueous polyurethane resin composition, and thermosetting the dried aqueous polyurethane resin composition at 150 to 250 ° C. The manufacturing method of the optical film which has a process is provided.

[Component (A)]
The 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 as the component (A) is a polymer compound having a relatively low molecular weight 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, various 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 differs greatly depending on the structure of the raw material used for the production of the urethane prepolymer. For this reason, it is impossible to represent the structure of the urethane prepolymer uniformly by a certain general formula, and this is the common general technical knowledge of those skilled in the art. And if the structure is not specified, the characteristics of the substance determined according to it cannot be easily understood, so it cannot be expressed by characteristics. Therefore, in the present invention, the urethane prepolymer contained in the aqueous polyurethane resin composition must be defined by the expression “a urethane prepolymer that is a reaction product of a polyol compound, a polyisocyanate compound, and an anionic group introducing agent”. Absent. In other words, regarding the urethane prepolymer used in the present invention, there is a situation where it is impossible or almost impractical to “directly specify the urethane prepolymer by its structure or characteristics at the time of filing”.

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 some or all of the polyisocyanate groups in the urethane prepolymer that is the reactant. Therefore, the difference between the four-component reactant and the three-component reactant of the polyol compound, the polyisocyanate compound and the anionic group introducing agent is whether or not the isocyanate group is blocked by the blocking agent. It is only a difference, and there is no essential difference in other configurations. Since the other configurations are the same, the same effects as when the three-component reactant is used as the component (A) can be obtained even when the four-component reactant is used. 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 polyol, polycarbonate diol, polyether polyol, and low molecular weight polyol having a number average molecular weight of less than 200.

Examples of the polyester polyol include compounds obtained by esterification reaction of low molecular weight polyols and polycarboxylic acids, compounds obtained by ring-opening polymerization reaction of cyclic ester compounds such as ε-caprolactone and γ-valerolactone, and the like. Those copolyesters can be used.

Examples of the low molecular weight polyol used in the polyester polyol 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, Opentyl glycol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,8-octane Aliphatic diols such as diol, aliphatic polyols such as glycerin, trimethylolpropane, ditrimethylolpropane, tritrimethylolpropane and pentaerythritol; aliphatic cyclic structures such as 1,4-cyclohexanedimethanol and hydrogenated bisphenol A Polyols: Bisphenol compounds such as bisphenol A, bisphenol F, bisphenol S, and alkylene oxide adducts thereof. The low molecular weight polyol used in the polyester polyol is preferably an aliphatic polyol or an aliphatic cyclic structure-containing polyol, more preferably an aliphatic diol, ethylene glycol, 1, 4 from the viewpoint of light transmittance and flexibility. More preferred are butanediol and 1,6-hexanediol. The low molecular weight polyol can be used alone or in combination of two or more.

Examples of the polycarboxylic acid used in the polyester polyol include aliphatic polycarboxylic acids such as succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, and dimer acid; 1,4-cyclohexanedicarboxylic acid , Cycloaliphatic tricarboxylic 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 may be an anhydride or an ester derivative. The polycarboxylic acid used in the polyester polyol is preferably an aliphatic polycarboxylic acid, more preferably an aliphatic dicarboxylic acid, and even more preferably adipic acid or sebacic acid from the viewpoint of light transmittance and flexibility. Polycarboxylic acid can be used alone or in combination of two or more.

Examples of the polycarbonate diol include those obtained by reacting a carbonate 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, and phenyl naphthyl carbonate.

Examples of the polyol used in 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, neopen 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 1,4-cyclohexanedimethanol, hydrogenated bisphenol A and other aliphatic cyclic structure-containing diols; Hydroquinone, resorcin, bisphenol A, bisphenol F, aromatic dihydroxy compounds such as 4,4′-biphenol Polyether polyols such as polyethylene glycol, polypropylene glycol and polytetramethylene glycol; polyester polyols such as polyhexamethylene adipate, polyhexamethylene succinate and polycaprolactone. The polyol used for the polycarbonate diol is preferably an aliphatic diol, more preferably 1,4-butanediol or 1,6-hexanediol, and more preferably 1,6-hexanediol from the viewpoint of light transmittance and flexibility. Further preferred.

As the polyether polyol, one obtained by addition polymerization of alkylene oxide using one or more compounds having two or more active hydrogen atoms as an initiator can be used.

Examples of the polyether polyol initiator include ethylene glycol, 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-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, saccharose, ethylenediamine, N-ethyldiethylenetriamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,2-diaminobutane, 1,3-diaminobutane, 1,4-diaminobutane , Diethylenetriamine, phosphoric acid, acidic phosphate, and the like.

Examples of the alkylene oxide used in 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, 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-octanedi And alicyclic diols such as cyclohexanedimethanol and cyclohexanediol; 3 such as trimethylolethane, trimethylolpropane, hexitols, pentitols, glycerin and pentaerythritol And higher polyols.

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

The molecular weight of the polyol compound is preferably a number average molecular weight of 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 in combination of 2 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 the polyisocyanate compound 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′-dimethyldiphenyl-4,4′-diisocyanate, dianisidine diisocyanate, tetramethylxylylene diisocyanate; isophorone diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, Cycloaliphatic diisocyanates such as trans-1,4-cyclohexyl diisocyanate and norbornene diisocyanate; 1,4-tetramethylene diisocyanate, 1,6-he Samethylene 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.

Examples of the polyisocyanate compound further include isocyanurate trimerized diisocyanate, trimethylolpropane adduct of diisocyanate, biuret trimerized diisocyanate, allophanate of diisocyanate, triphenylmethane triisocyanate, 1-methylbenzol. Examples thereof include trifunctional or higher functional isocyanates such as -2,4,6-triisocyanate, dimethyltriphenylmethane tetraisocyanate, 1,5,11-undecamethylene tridiisocyanate, and 2,4,6-toluene isocyanate.

The polyisocyanate compound used for the component (A) is preferably an alicyclic diisocyanate or an aliphatic diisocyanate, more preferably an alicyclic diisocyanate, from the viewpoints of light transmittance, heat resistance and adhesiveness, and dicyclohexylmethane-4. 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. An example of such a functional group is a hydroxyl group. Examples of the anionic group-introducing agent used for the component (A) include polyols containing a carboxyl group such as dimethylolpropionic acid, dimethylolbutanoic acid, dimethylolbutyric acid, dimethylolvaleric acid, and the like; 1,4-butanediol Examples include polyols containing sulfonic acid groups such as -2-sulfonic acid. From the viewpoint of heat resistance and industrial availability, polyols containing a carboxyl group are preferred, and dimethylolpropionic acid is more preferred.

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 be lowered. 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, based on the amount of the urethane prepolymer of component (A). More preferred is 0.4 to 1.0 mmol / g. The anionic group content (unit: mmol / g) can be calculated from the acid value (unit: mgKOH / g). That is, a value obtained by multiplying the content of the anionic group by 56.1 (potassium hydroxide molecular weight) corresponds to the acid value. In addition, the content of an anionic group 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 part derived from the anionic group neutralizing agent in the urethane prepolymer is not included in the total amount. In addition, the acid value of the above-mentioned (A) component is the 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. In addition, the amount of the urethane prepolymer is such that when the urethane prepolymer is a reaction product of a polyol compound, a polyisocyanate compound, an anionic group introducing agent, and a blocking agent, a polyol compound, a polyisocyanate compound, an anion This is the total amount of the sex group introducing agent and 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) in 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 production of the urethane prepolymer is greater than 1, and a hydroxyl group when the NCO index is less than 1. Since the end group of the urethane prepolymer is highly dispersible in water and can be easily polymerized by chain extension, an isocyanate group is preferable to a hydroxyl group, and thus the NCO index is preferably larger than 1.

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 is 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 remaining isocyanate groups and water is generated in the process of dispersing in water, which may cause rapid foaming and cause manufacturing problems. There is also a risk that the adhesiveness of the object may be lowered. When the component (A) is produced, the NCO index is preferably 1.1 to 2.5, more preferably 1.2 to 2.0, and preferably 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 facilitate the urethanization reaction. 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 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 Razine, 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; tetraalkylammonium halides such as tetramethylammonium chloride, tetraalkylammonium hydroxides such as tetramethylammonium hydroxide, tetramethylammonium 2- Quaternary ammonium salts such as tetraalkylammonium organic acid salts such as ethylhexanoate; stanas diacetate, stanas dioctoate, stanas dioleate, stanas dilaurate, dibuty 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 organometallic catalyst is preferred because of good reactivity and less yellowing of the resulting polyurethane resin, and dibutyltin dilaurate or dioctyltin dilaurate is more preferred. 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, polyisocyanate compound and anionic group introducing agent. .

The isocyanate group of the component (A) in the water-based polyurethane resin composition of the present invention is preferably a blocked isocyanate group in which a part or all of the isocyanate group is blocked with a blocking agent because of improved adhesiveness. Examples of the blocking agent include phenol blocking agents such as phenol, cresol, xylenol, chlorophenol, and ethylphenol; lactam blocking agents such as ε-caprolactam, δ-valerolactam, γ-butyrolactam, β-butyrolactam, and the like. Active methylene 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 blocking agents such as butyl acid, diacetone alcohol, methyl lactate, ethyl lactate; formaldoxime, acetoaldoxime, aceto Oxime blocking agents such as shim, methyl ethyl ketoxime, diacetyl monooxime, cyclohexane oxime; mercaptan blocking agents such as butyl mercaptan, hexyl mercaptan, t-butyl mercaptan, thiophenol, methylthiophenol, ethylthiophenol; Amide blocking agents such as benzamide; Imide blocking agents such as succinimide and maleic imide; pyrazole, 3,5-dimethylpyrazole, 4-benzyl-3,5-dimethylpyrazole, 4-nitro-3, Examples thereof include pyrazole-based blocking agents such as 5-dimethylpyrazole, 4-bromo-3,5-dimethylpyrazole and 3-methyl-5-phenylpyrazole; imidazole-based blocking agents such as 2-ethylimidazole. Since 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 is easy to handle, oxime blocking agents and pyrazole blocking agents are preferred, and methyl ethyl keto More preferred are oxime and 3,5-dimethylpyrazole. When the content of the blocked isocyanate group in the component (A) is too small, a sufficient effect of improving adhesiveness cannot be obtained, and when all the isocyanate groups are converted to blocked isocyanate groups, the component (A) However, the content of the blocked isocyanate group in the component (A) is that of the polyol compound and the anionic group introducing agent in the component (A). The excess amount 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%. In addition, when calculating the content of the anionic group in the component (A), the content of the anionic group is a molar amount relative to the total amount of the mass of the structural portion derived from the polyol compound, the polyisocyanate compound and the anionic group introducing agent. And although the structure part originating in an anionic group neutralizing agent shall not be included in the said total amount, it shall calculate by including in the said total amount about the structure part derived from a blocking agent.

Since the water dispersibility is improved, the anionic group of the component (A) is preferably neutralized with an anionic group neutralizing agent. Examples of the anionic group neutralizing agent include trialkylamines such as trimethylamine, triethylamine, and tributylamine; and basic compounds such as ammonia, trimethylammonium hydroxide, sodium hydroxide, potassium hydroxide, and lithium hydroxide. If the anionic group neutralizing agent remains in the easily adhesive layer of the water-based polyurethane resin composition of the present invention, it may adversely affect the light resistance of the easily adhesive layer. Compounds that dissociate and volatilize are preferred, and trimethylamine and triethylamine are preferred.

If the amount of the anionic group neutralizer used is too small, the water dispersibility of the component (A) is not sufficiently improved, and if 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 an anionic group.

The component (A) is preferably polymerized with a chain extender because durability and adhesion are improved. As 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, 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-octanediol, 1,9-nonanediol, etc. All; cycloaliphatic diols such as cyclohexanedimethanol and cyclohexanediol; low molecular diamines such as ethylenediamine, propylenediamine, hexamethylenediamine, tolylenediamine, piperazine, 2-methylpiperazine; diethylenetriamine, triethylenetetramine, tetraethylenepenta Polyalkylene polyamines such as min; alkanolamines such as monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, 2- (2-aminoethylamino) ethanol; polyoxypropylenediamine, Polyether diamines such as polyoxyethylene diamine; mensen 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- Cycloaliphatic diamines such as tetraoxaspiro (5,5) undecane; m-xylenediamine, α- (m / p-aminophenyl) ethylamine, m-phenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, diaminodimethyldiphenylmethane, Polyamines of aromatic diamines such as diaminodiethyldiphenylmethane, dimethylthiotoluenediamine, diethyltoluenediamine, α, α'-bis (4-aminophenyl) -p-diisopropylbenzene; succinic dihydrazide, adipic acid di Hydrazide, sebacic acid dihydrazide, phthalic acid dihydrazide, 1,6-hexamethylenebis (N, N-dimethylsemicarbazide), 1,1,1 ′, 1′-tetramethyl-4,4 ′-(methylene-di-para Hydrazides such as -phenylene) disemicarbazide; hydrated hydrazine and the like. Water functions not only as a dispersion medium but also as a chain extender. However, since the reaction with an isocyanate group is not always rapid, it is not included in the chain extender in the present invention.

As the chain extender, low-molecular diamines, alkanolamines, polyalkyleneamines, hydrazides, and hydrated hydrazines are preferable because they are easy to react and industrially available. Ethylenediamine, monoethanol More preferred are amines. The chain extender is used in an amount of 0.01 to 1. mol of the group capable of reacting with the isocyanate group of the chain extender relative to the isocyanate group of the urethane prepolymer (excluding the blocked isocyanate group). 0 is preferred.

[(B) component]
The component (B) in the aqueous polyurethane resin composition of the present invention is a blocked polyisocyanate compound. Since the water-based polyurethane resin composition is excellent in dispersibility in water, a self-emulsifying blocked polyisocyanate compound or a forced emulsification type blocked polyisocyanate compound is often used. In the present invention, the self-emulsifying blocked polyisocyanate compound refers to a blocked polyisocyanate compound which has an emulsifying and dispersing property in water and can be dispersed in water without using a surfactant. The blocked polyisocyanate compound is a non-self-emulsifying blocked polyisocyanate compound dispersed in water with a surfactant. Further, the non-self-emulsifying blocked polyisocyanate compound refers to a blocked polyisocyanate compound that is not dispersed 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-emulsification. When a forced emulsification type blocked polyisocyanate compound or a self-emulsifying blocked polyisocyanate compound is used, the surfactant of the forced emulsification type blocked polyisocyanate compound or the polyethylene glycol chain of the self-emulsifying blocked polyisocyanate compound is A non-self-emulsifying blocked polyisocyanate compound is preferred as the component (B) in the present invention because it may adversely affect the transparency of the easily adhesive layer in a high humidity atmosphere.

Examples of the non-self-emulsifying blocked polyisocyanate compound include a compound obtained by blocking an isocyanate group of a diisocyanate compound with a blocking agent, a compound obtained by blocking an isocyanate group of a trifunctional or higher polyisocyanate compound with a blocking agent, and the like. From the viewpoint of adhesion, a compound obtained by blocking the isocyanate group of a trifunctional or higher polyisocyanate compound with a blocking agent is preferable. Examples of such a polyisocyanate compound include the isocyanurate trimerized diisocyanate exemplified for the polyisocyanate compound (A), the trimethylolpropane adduct of diisocyanate, the biuret trimerized diisocyanate, the allophanate of diisocyanate, and triphenyl. Trifunctional such as methane triisocyanate, 1-methylbenzole-2,4,6-triisocyanate, dimethyltriphenylmethane tetraisocyanate, 1,5,11-undecamethylene tridiisocyanate, 2,4,6-toluene isocyanate The above isocyanate etc. are mentioned. Moreover, what connected triisocyanate or more polyisocyanate compounds with a polyol compound may be sufficient. Examples of the blocking agent for the non-self-emulsifying blocked polyisocyanate compound include the compounds exemplified as the blocking agent for component (A), and the dissociation temperature of the blocking agent from the blocked isocyanate group is that of the urethane resin composition. An oxime blocking agent and a pyrazole blocking agent are preferred, and methyl ethyl ketoxime and 3,5-dimethylpyrazole are more preferred because they are slightly lower than the curing temperature (described later) and easy to handle. Particularly preferred as the component (B) are those obtained by blocking the isocyanurate trimerization of hexamethylene diisocyanate with methyl ethyl ketoxime, those obtained by blocking the isocyanurate trimerization of hexamethylene diisocyanate with 3,5-dimethylpyrazole, Hexamethylene diisocyanate isocyanurate trimerized with polytetramethylene glycol and blocked with methyl ethyl ketoxime, hexamethylene diisocyanate isocyanurate trimerized with polytetramethylene glycol and blocked with 3,5-dimethylpyrazole And the like.

The weight average molecular weight of the blocked polyisocyanate compound (B) used in the aqueous polyurethane resin of the present invention is not particularly limited, but is preferably 50000 or less. When the weight average molecular weight of the (B) component blocked polyisocyanate compound is more than 50000, 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 aqueous 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 easy-adhesion layer is reduced, or relatively ( There are cases where the content of the component (B) increases and the dispersion stability of the component (B) decreases. 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 based on the solid content. Further, the content of the blocked isocyanate group is preferably 3.9 mmol / g or less, more preferably 3.8 mmol / g or less, still more preferably 3.7 mmol / g or even 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 addition, in this invention, solid content means components other than volatile components, such as a water | moisture content in a composition, and an organic solvent, for example, calculates from the volatile residue when a composition is heated at 105 degreeC for 1 hour. be able to.

The ratio of the component (A) to the component (B) in 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. Since the dispersion stability of the component (B) is lowered when the amount of the component (A) is too small, the content of the component (A) as the solid content is the total amount of the solid content of the component (A) and the component (B). The amount is preferably at least 20 parts by mass, more preferably at least 25 parts by mass with respect to 100 parts by mass.

The amount of water in the water-based polyurethane resin composition of the present invention is preferably smaller because the amount of active ingredients is relatively larger. However, if the amount is too small, the dispersion stability decreases, so the water-based polyurethane resin composition of the present invention. The amount of water is preferably 60 to 1000 parts by weight, more preferably 100 to 400 parts by weight, and most preferably 150 to 250 parts by weight with respect to 100 parts by weight 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. Examples of such additives include cross-linking agents, various weathering agents (hindered amine light stabilizers, ultraviolet absorbers and antioxidants), silane coupling agents that particularly strengthen adhesion to substrates, colloidal silica, Inorganic colloidal sol such as colloidal alumina, tetraalkoxysilane and its condensation polymer, chelating agent, epoxy compound, pigment, dye, film-forming aid, curing agent, external cross-linking agent, viscosity modifier, leveling agent, antifoaming agent, coagulation Inhibitors, radical scavengers, heat resistance imparting agents, inorganic or organic fillers, plasticizers, lubricants, antistatic agents such as fluorine or siloxane, reinforcing agents, catalysts, thixotropic agents, waxes, antifogging agents Antibacterial agents, fungicides, anticorrosives, rust inhibitors, and the like can be used.

The above crosslinking agent can improve durability by introducing a crosslinked structure into the aqueous polyurethane resin composition of the present invention. Examples of the cross-linking agent include urea, melamine compounds, adducts of benzoguanamine and the like with formaldehyde, amino resins composed of the above adducts and alkyl ether compounds containing an alcohol unit having 1 to 6 carbon atoms, and polyfunctional epoxy compounds; A polyfunctional isocyanate compound; a polyfunctional aziridine compound and the like can be mentioned, and a melamine compound is preferable because of excellent reactivity. Examples of the melamine compound include melamine, monomethylol melamine, dimethylol melamine, trimethylol melamine, tetramethylol melamine, pentamethylol melamine, hexamethylol melamine, methylated methylol melamine, butylated methylol melamine, and melamine resin. Melamine is preferred because it is inexpensive and has excellent dispersibility.

Examples of the 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 , 2,6,6-tetramethyl-4-piperidyl) amino) -s-triazin-6-yl] -1,5,8,12-tetraazadodecane, 1,5,8,12-tetrakis [2, 4-bis (N-butyl- -(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 , 4-bis (N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino) -s-triazin-6-ylaminoundecane and the like.

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-hydroxybenzophenones such as 2-; 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- 3-octyl-6-benzotriazolylphenol), 2- (2-hydroxy-3-tert-butyl-5-carboxyphenyl) benzotriazole polyethylene glycol ester, 2- [2-hydroxy-3- (2-acryloyl) Oxyethyl) -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] Nzotriazole, 2- [2-hydroxy-3-tert-butyl-5- (2-methacryloyloxyethyl) phenyl] benzotriazole, 2- [2-hydroxy-3-tert-amyl-5- (2-methacryloyl) Oxyethyl) 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) ) Phenyl] benzotriazole and the like 2- (2-hydroxyphene) Nyl) 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-allylphenol ) -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2,4,6-tris (2-hydroxy-3-methyl-4-hexyloxyphenyl) -1, 2- (2-hydroxyphenyl) -4,6-diaryl-1,3,5-triazines such as 3,5-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- Benzoates such as tert-butyl-4-hydroxy) benzoate and behenyl (3,5-ditert-butyl-4-hydroxy) benzoate; 2-ethyl-2′-ethoxyoxanilide, 2-ethoxy-4′- Substituted oxanilides such as dodecyl oxanilide; Cyanoacrylates such as ethyl-α-cyano-β, β-diphenyl acrylate, methyl-2-cyano-3-methyl-3- (p-methoxyphenyl) acrylate; and various Metal salts or metal chelates, such as nickel or chromium salts or chelates.

As the antioxidant, phosphorus antioxidants, phenol antioxidants, sulfur antioxidants can be used. Examples of phosphorus antioxidants include triphenyl phosphite, tris (2,4-di-tert-butylphenyl) phosphite, tris (2,5-di-tert-butylphenyl) phosphite, tris (nonylphenyl) Phosphite, tris (dinonylphenyl) phosphite, tris (mono, dimixed nonylphenyl) phosphite, diphenyl acid phosphite, 2,2′-methylenebis (4,6-ditertiarybutylphenyl) octyl phosphite, Diphenyldecyl phosphite, diphenyloctyl 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 (neopentylglycol) -1,4-cyclohexanedimethyldiphosphite, bis (2,4-ditertiarybutylphenyl) pentaerythritol diphos Phyto, bis (2,5-ditertiarybutylphenyl) pentaerythritol diphosphite, bis (2,6-ditertiarybutyl-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′-methylenebis (4 6-ji 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-ditert-butylphenyl) biphenylene diphosphonite, tris (2-[(2,4,7,9-tetrakis) Tert-butyldibenzo [d, f] [1,3,2] dioxaphosphin-6-yl) oxy] ethyl) amine, 9,10-dihydro-9-oxa-10-phosphaphenanthrene- 10-oxide, tris (2-[(2,4,8,10-tetrakis tert-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] dioxaphosphin-6-yl] oxy] propyl] phenol and 2-butyl-2-ethylpropanediol-2,4,6-tritert-butylphenol mono Phosphite or the like can be used.

Examples of the phenol-based antioxidant include 2,6-ditertiarybutyl-p-cresol, 2,6-diphenyl-4-octadecyloxyphenol, stearyl (3,5-ditertiarybutyl-4- Hydroxyphenyl) propionate, distearyl (3,5-ditertiarybutyl-4-hydroxybenzyl) phosphonate, tridecyl 3,5-ditertiarybutyl-4-hydroxybenzylthioacetate, thiodiethylenebis [(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, -Bis (4-hydroxy-3-tert-butylphenyl) butyric acid] glycol ester, 4,4'-butylidenebis (2,6-ditert-butylphenol), 4,4'-butylidenebis (6-tert-butyl) -3-methylphenol), 2,2′-ethylidenebis (4,6-ditert-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- Hydroxy-4-tert-butylbenzyl) isocyanurate, 1,3,5-tris (3,5-ditert-butyl-4-hydroxybenzyl) isocyanurate, 1,3,5- Lis (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′-ditert-butyl-4′-hydroxyphenyl) propionate] methane, 2-tert-butyl-4-methyl-6- (2-acrophenyl) 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) Ropioneto], and it can be used tocopherol.

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

The amount of the weathering agent (hindered amine light stabilizer, ultraviolet absorber and antioxidant) used is preferably 0.001 to 10 parts by mass, more preferably 100 parts by mass based on the solid content of the aqueous polyurethane resin composition. 0.01 to 5 parts by mass. If the amount of the weathering 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 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 a known additive is used, a surfactant may be used as a dispersant or an emulsifier. When the content of the surfactant in the aqueous polyurethane resin composition is large, the transparency of the easy-adhesion 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, based on 100 parts by mass of the solid content of the aqueous polyurethane resin composition, and 0.2 parts by mass. More preferably, it is as follows.

〔Production method〕
The water-based 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. In the case where the component (B) is a self-emulsifying blocked polyisocyanate compound or a forced emulsification type blocked polyisocyanate compound, the component (B) is 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 blend the component (B) after the component (A) is dispersed in water. Below, the manufacturing method in case (B) component is a non-self-emulsification 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 reacted by optionally adding a catalyst or a crosslinking agent, and a urethane prepolymer as component (A). Manufacturing. The urethane prepolymer can be produced by a conventional method, and the reaction temperature can be set to a normal urethanization reaction temperature, for example, 50 to 100 ° C., and does not react with an isocyanate group in order to facilitate the reaction. An inert solvent can also be used. The inert solvent used for the production is preferably an organic solvent having a high affinity with water since 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, polyisocyanate compound, and anionic group introducing agent.

When the isocyanate group of the component (A) is blocked with a blocking agent, it can be reacted with the polyisocyanate compound at the same time as the production of the urethane prepolymer, or the urethane group can be reacted. A blocking agent may be charged and reacted during or after the reaction. 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 blocking agent or a pyrazole blocking agent.

Since the non-self-emulsifying blocked polyisocyanate is difficult to disperse in water, the urethane prepolymer (A) and the non-self-emulsifying blocked polyisocyanate (B) are mixed and then dispersed in water. By mixing the component (A) and the component (B) and then dispersing in water, the component (B), which was difficult to disperse in water, can be dispersed in water. Since it has emulsifying properties, it is considered that component (B) can be dispersed when component (A) functions as an emulsifier for component (B). As a method for dispersing in water, a prepolymer mixing method and a phase inversion method are preferable because of good dispersibility in water. In the prepolymer mixing method, an anionic group neutralizing agent is added to and mixed with the urethane prepolymer of component (A), and the mixture is poured into water and dispersed in water. In the phase inversion method, urethane of component (A) is used. Add water containing an anionic group neutralizer to the prepolymer, or add an anionic group neutralizer to the urethane prepolymer of component (A) and mix, then add water to the mixture and disperse 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) is before the coexistence with water, but the urethane prepolymer is neutralized with an anionic group. When adding and mixing the agent, it is preferable to add and mix the anionic group neutralizing agent together with the component (B).

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

When using a chain extender, dissolve it in water used to disperse the components (A) and (B). When a chain extender is used, if the temperature of water is low, the reaction takes a long time, resulting in a decrease in production efficiency. If it is too high, carbon dioxide is generated due to the rapid reaction between the isocyanate group and water as described above. Since a foaming phenomenon may occur, the temperature of water when a 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 chain extension, a method of confirming disappearance of the isocyanate group using 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-water-dispersible. In the same manner as the component (B), the additive is preferably mixed with the urethane prepolymer of the component (A) and then dispersed in water.

In addition, when an organic solvent is used for manufacture of (A) component, although an aqueous polyurethane resin composition will contain an organic solvent, from a viewpoint of safety, such as environmental pollution and occupational health, an aqueous polyurethane resin composition The organic solvent in the product is preferably removed by a method such as distillation under reduced pressure.

[Use]
Since the water-based polyurethane resin composition of the present invention is excellent in adhesion to a substrate, blocking resistance, transparency, heat resistance, etc., it can be used as various adhesives. It can be suitably used as an easy adhesion layer. A film intended to transmit or reflect and absorb light and give various effects is called an optical film. As an optical film, a reflection 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 thereof include a low-pass filter, a lens filter, a conductive film for a touch panel, a light diffusion film, an antiglare film, and a prism sheet. Since the resin film substrate of the optical film is excellent in transparency, flexibility and physical strength, polyester resins such as polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT) are generally used. used. The conventional water-based polyurethane resin composition used in the easy-adhesion layer of the optical film has insufficient adhesion to the easy-adhesion layer with the polyester resin of the base material. 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 is excellent in adhesiveness with a polyester resin, high adhesiveness is obtained even for such a non-surface-treated substrate, and an adhesive for polyester resin. Especially, it can be used conveniently as an easily bonding layer of the optical film in which transparency and adhesiveness are required. 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 the acrylic resin is used, for example, a polarizing film, a light diffusion film, a reflective film, an antireflection film, an anti-reflection film, and the like. It is preferably used as an easy-adhesion layer for a dazzling film, a prism sheet or the like, and more preferably used 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 substrate, dried, and then heat treated and cured to form an easy adhesion layer. The application method of the aqueous polyurethane resin composition of the present invention is not particularly limited, and a known method 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, a 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 above the dissociation temperature of the blocking agent. That is, the blocking agent is dissociated from the blocked isocyanate group by heating, the active isocyanate group is regenerated, and is cured by reacting with a hydroxyl group or an amino group to form a urethane group or a urea group. The dissociation temperature of the blocked isocyanate group is about 140 to 160 ° C. for the oxime blocking agent and about 110 to 120 ° C. for the pyrazole blocking agent. When the temperature is high, the isocyanate group reacts with the urethane group or urea group to form an allophanate group or a burette group and crosslink, and these generated groups 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 substrate 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 standard. 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 by way of 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: Polycarbonate diol polyol a2 having a number average molecular weight of 2000 a2: Polytetramethylene glycol monool having a number average molecular weight of 1000 a′1: Polyethylene glycol monomethyl ether polyisocyanate having a number average molecular weight of 550 b1: Isophorone diisocyanate polyisocyanate b2: Dicyclohexylmethane 4,4′-Diisocyanate polyisocyanate b3: Isocyanurate trimerized hexamethylene diisocyanate (isocyanate content 21.8%)
Anionic group introduction agent c1: dimethylolpropionic acid anionic group neutralizing agent d1: triethylamine chain extender e1: ethylenediamine chain extender e2: monoethanolamine blocking agent f1: methyl ethyl ketoxime blocking agent f2: 3, 5- Dimethylpyrazole MEK: Methyl ethyl ketone

[Production Example 1: Prepolymer A1]
13. In a glass reaction vessel having a stirrer, a cooling tube, and a nitrogen introduction tube, 313.9 g of polyol a1, 280.0 g of polyisocyanate b1, 80.8 g of anionic group introduction agent 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 prepolymer A1 containing a solvent. 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 blocked isocyanate groups (hereinafter also referred to as B-NCO) in the prepolymer A1 is 0.177 mmol / g, and the content of blocked isocyanate groups relative to the solid content of the prepolymer A1 is 0.241 mmol / g. It is.

[Production Examples 2 to 8: Prepolymers A2 to A8]
Urethane prepolymers A2 to A8 were produced in the same manner as in Production Example 1 except that the amount of each raw material charged was changed as shown in Table 1.
In addition, the numerical value of the preparation amount of each raw material in Table 1 is g number. As for the content of anionic groups and B-NCO, the upper value is the value for the solid content of the prepolymer, and the lower value in () is the value for the prepolymer containing the solvent.

[Production Example 9: Blocked polyisocyanate B1]
In a glass reaction vessel having a stirrer, a cooling tube, and a nitrogen introduction tube, 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. The mixture was stirred and reacted at 80 ° C. for 5 hours 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 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 polyisocyanate 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 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, trade name: Adecanol SP-12, HLB: 12.7), 45 g of water were treated with a homomixer to be blocked. Blocked polyisocyanate B4, which is an emulsified dispersion of polyisocyanate B1, was obtained. Blocked polyisocyanate B4 is a forced emulsification type blocked polyisocyanate compound.

Table 2 shows the charged amount (g) of each raw material of blocked polyisocyanate B1 to 5 and the content of B-NCO. The B-NCO content value is the upper value relative to the solid content of the blocked polyisocyanate, and the lower value in parentheses is the value containing the solvent.

[Example 1]
In a resin container, 56.35 g of prepolymer A1, 3.65 g of anionic group neutralizing agent 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 molar amount as the anionic group introducing agent in the brepolymer. A glass reaction vessel having a stirrer was charged with 150 g of water and 0.02 g of an antifoaming agent (manufactured by ADEKA, trade name: Adecanate B-1016). The mixture was added over a period of 30 minutes and further stirred at 40 ° C. for 30 minutes. After adding 0.224 g of a 25% by weight aqueous solution of chain extender e1 (0.056 g as chain extender e1) and stirring at 40 ° C. for 1 hour, MEK was removed under reduced pressure conditions. An aqueous polyurethane resin composition was obtained. In addition, Example 1 is an Example using a non-self-emulsifying blocked polyisocyanate compound.

[Examples 2 to 10, Comparative Examples 1 to 8]
Except for changing the charged amount (g) of each raw material as described in Table 3, the same operations as in Example 1 were performed 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 molar amount as the anionic group introducing agent in the brepolymer, and the amounts of the chain extenders e1 and e2 are 25% aqueous solution. . Examples 2 to 10 and Comparative Examples 1 to 8 are examples using a non-self-emulsifying blocked polyisocyanate compound.

Example 11
A resin container was charged with 46.95 g of prepolymer A1 and 3.05 g of an anionic group neutralizing agent d1, and stirred for 5 minutes to obtain a mixture. A glass reaction vessel having a stirrer was charged with 150 g of water and 0.02 g of an antifoaming agent (manufactured by ADEKA, trade name: Adecanate B-1016). After adding for 30 minutes and further stirring at 40 ° C. for 30 minutes, 0.19 g of a 25% by mass aqueous solution of chain extender e1 was added and stirred at 40 ° C. for 1 hour. To this was added 50 g of blocked polyisocyanate B3, and the mixture was stirred and dispersed at 40 ° C. for 1 hour, 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 neutralizing agent d1 were charged and stirred for 5 minutes to obtain a mixture. A glass reaction vessel having a stirrer was charged with 120 g of water, 0.02 g of an antifoaming agent (manufactured by ADEKA, trade name: Adecanate B-1016), and 70 g of blocked polyisocyanate B4 at 40 ° C. While stirring, the mixture was added over 2 minutes. Furthermore, after stirring at 40 ° C. for 30 minutes, 0.23 g of a 25% by mass aqueous solution of a chain extender e1 was added, and the mixture was stirred at 40 ° C. for 1 hour. 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 emulsification type blocked polyisocyanate compound.

Table 3 shows the charged amount (g) of each raw material of the aqueous 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 components (A) and (B), and the B-NCO content value is the value relative to the solid content.

The aqueous 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 evaluation of adhesion, and the following test piece A was used for evaluation of moisture resistance 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., test piece A was prepared by heating at 180 ° C. for 10 minutes.
Specimen B: A commercially available PET film was subjected to corona treatment with a corona treatment device until the average water contact angle on the surface reached 28 to 32 °, and the thickness of the coating film after drying was 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: A commercially available acrylic photocurable resin (manufactured by ADEKA Co., Ltd., trade name: ADEKA OPTMER HC-211) having a thickness of about 3 μm on the surface of test piece B coated with urethane resin After applying −9) and drying at 80 ° C., a specimen C was prepared by curing 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 .

<Storage stability test method>
The aqueous polyurethane resin composition was put in a sealed container and stored at 40 ° C. for 24 hours, and then storage stability was evaluated based on the following evaluation criteria from the presence or absence of separation. In addition, the following test was not performed for those having poor storage stability.
(Evaluation criteria)
○: No separation was observed and storage stability was good. ×: Separation was observed and storage stability was poor.

<Adhesion test method>
In accordance with JIS K5600-5-6 (General test method for paints-Part 5: Mechanical properties of coating film-Section 6: Adhesiveness (cross-cut method)), using a cutter guide with a gap interval 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 performing the operation of attaching and peeling the adhesive tape three times on the same test piece, the number of squares where no peeling occurred was counted. It shows that adhesiveness is so high that the number of the squares where peeling does not occur is large.

<Moisture transparency test method>
Specimen A was allowed to stand in a constant temperature and humidity chamber at 80 ° C. and 80% relative humidity for 250 hours, and then the haze value (%) was measured using a haze meter (Nippon Denshoku Industries Co., Ltd., model: NDH-5000). did. A value obtained by subtracting the haze value of the commercially available PET film used for the preparation of 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 resistance 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, applied with a load of 10 kgf / cm ² , and placed in a constant temperature and humidity chamber at 60 ° C. and a relative humidity of 80%. It was allowed to stand for 24 hours. Thereafter, the overlapping test pieces were peeled off, and the ratio (%) of the area of the damaged 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 broken surface, the higher the blocking resistance.

[Examples 13 and 14, Comparative Example 9]
Except having changed the preparation amount (g) of each raw material as described in Table 5, the same operation as Example 1 was performed and the water-based polyurethane resin composition of Examples 13 and 14 and the comparative example 9 was obtained. In Table 5, the amount of the anionic group neutralizing agent used is the same molar amount as the anionic group introducing agent in the prepolymer, and the amount of the chain extender e2 charged is the amount of 25% aqueous solution.
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 charged amounts (g) of the respective raw materials of the aqueous 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 components (A) and (B), and the B-NCO content value is the value relative to the 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 put in a sealed container and 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: One month or more, good storage stability B: Precipitation / separation is observed in less than 2 weeks, storage stability is poor C: Precipitation / separation is observed in less than one week, storage stability is poor

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

ADVANTAGE OF THE INVENTION According to this invention, the water-based polyurethane resin excellent in adhesiveness and blocking resistance with a polyester resin can be provided, Furthermore, by using a specific polyisocyanate compound in the case of manufacture of a polyurethane resin, it is transparent. A water-based polyurethane resin having excellent properties can be provided. Moreover, according to this invention, the water-based polyurethane resin excellent in storage stability can be provided.

Claims

As the 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 the component (B), a blocked polyisocyanate compound is contained, and the content of the blocked isocyanate group is An aqueous polyurethane resin composition having a solid content of 0.5 to 4 mmol / g.
The water-based polyurethane resin composition according to claim 1, wherein the polyol compound is a polycarbonate diol.
The aqueous 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 based on 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 a part or all of the isocyanate groups in the component (A) are blocked isocyanate groups 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.
6. The aqueous polyurethane resin composition according to claim 1, wherein the blocking agent for the blocked isocyanate group is an oxime blocking agent or a pyrazole blocking agent.
A polyester resin adhesive comprising the water-based polyurethane resin composition according to any one of claims 1 to 6.
An optical film adhesive comprising the water-based polyurethane resin composition according to any one of claims 1 to 6.
A method for producing the aqueous polyurethane resin composition according to claim 5,
A step of producing a urethane prepolymer by reacting a polyol compound, a polyisocyanate compound and an anionic group-introducing agent, a step of mixing a urethane prepolymer and a non-self-emulsifying blocked polyisocyanate compound, and a mixture thereof; A method for producing an aqueous polyurethane resin composition, comprising a step of dispersing in water.
A step of applying the aqueous polyurethane resin composition according to any one of claims 1 to 6 to a substrate film, a step of drying the applied aqueous polyurethane resin composition, and 150 to 150 of the dried aqueous polyurethane resin composition. The manufacturing method of the optical film which has the process of thermosetting at 250 degreeC.