JP2004059894A - Water-based polyurethane resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water-based polyurethane resin having flexibility specific to the water-based polyurethane resin, having good stability under high temperature and low temperature conditions, and having good adhesion to a plastic. <P>SOLUTION: This water-based polyurethane resin comprises a high-molecular weight polyol component, a polyisocyanate compound, and a chain extender, wherein the high-molecular weight polyol component contains a liquid polytetrahydrofuran-based polyether polyol which is obtained by copolymerizing tetrahydrofuran with an alkylene oxide having an alkyl in its side chain or an alcohol having an alkyl in its side chain. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an aqueous polyurethane resin. In more detail, it has excellent adhesion and blocking resistance to plastics such as nylon and polyester, paint, ink, glass shatterproof film, synthetic leather, artificial leather, non-woven fabric, woven fabric, paper, wood, The present invention relates to an aqueous polyurethane resin that can be suitably used as a coating agent for a steel plate, rubber, leather, floor polish, a sizing agent for glass fiber, a coating agent for an ink jet receiving layer, an adhesive, an adhesive, and the like.
[0002]
[Prior art]
In the past, polymer organic solvent solutions were mainly used as coatings and adhesives for paints, inks, etc., but recently, prevention of air pollution and other pollution, regulations under the Fire Service Law, working conditions In consideration of the safety and hygiene of the polymer, replacement with a water-soluble polymer or an emulsion of a polymer is eagerly desired. As the water-soluble polymer, an aqueous polyurethane resin having flexibility is conceivable, but the aqueous polyurethane resin has insufficient adhesion to plastic, and has stability at high or low temperature. There was a disadvantage that it was insufficient. In order to improve the adhesion to plastic, a polyurethane resin having a polyethylene oxide constituent unit and a pendant anionic group has been proposed (see Patent Document 1). Was not sufficiently stable.
[0003]
By the way, a method of using a specific polyether glycol has been proposed as a method for improving the elastic properties of a polyurethane resin at a low temperature (see Patent Document 2). However, an aqueous polyurethane resin using the polyether glycol has been proposed. Has not been considered before.
[0004]
[Patent Document 1]
JP-A-6-346012
[Patent Document 2]
JP-A-5-32775
[0005]
[Problems to be solved by the invention]
The present invention has been made in view of the above prior art, and has the flexibility unique to aqueous polyurethane resins, has good stability at high and low temperatures, and has good adhesion to plastics. It is intended to provide a resin.
[0006]
[Means for Solving the Problems]
Means for Solving the ProblemsThe present inventors have conducted intensive studies in order to solve the above problems, and by using a specific liquid polytetrahydrofuran-based polyether polyol, solved the above problems completely, and printed the aqueous polyurethane resin. It has been found that when used as a binder for inks, in addition to stability at low and high temperatures, adhesion to various plastics can be improved. The present invention has been completed based on such findings.
[0007]
That is, in an aqueous polyurethane resin comprising a high molecular weight polyol component, a polyisocyanate compound and a chain extender, the high molecular weight polyol component copolymerizes tetrahydrofuran and an alkylene oxide having an alkyl group in a side chain or an alcohol having an alkyl group in a side chain. An aqueous polyurethane resin containing a liquid polytetrahydrofuran-based polyether polyol obtained by the above method; a binder for a printing ink using the aqueous polyurethane resin; and a printing ink composition containing the binder for a printing ink.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention is characterized in that a liquid polytetrahydrofuran-based polyether polyol is contained as a high molecular weight polyol component which is a constituent component of the aqueous polyurethane resin. The liquid polytetrahydrofuran-based polyether polyol used in the present invention is obtained by copolymerizing tetrahydrofuran and an alkylene oxide having an alkyl group in a side chain or an alcohol having an alkyl group in a side chain by various known methods. is there. Examples of the copolymerization include a method in which tetrahydrofuran and an alkylene oxide having an alkyl group in a side chain are polymerized in the presence of a ring-opening catalyst, and a method in which tetrahydrofuran and an alcohol having an alkyl group in a side chain are reacted with a catalyst such as a heteropoly acid or toluene sulfonic acid. And a method of polymerizing in the presence. The ring-opening catalyst is not particularly limited, and a known one can be used. Specifically, for example, strong acids such as chlorosulfonic acid and fluorosulfonic acid can be mentioned. Specific examples of the alkylene oxide having an alkyl group in a side chain, which is one of the components of the copolymer, include 1,2-propylene oxide, 1,2-butylene oxide, 3-methyltetrahydrofuran, 3-methyloxetane, 3,3-dimethyloxetane and the like. Among them, industrially useful ones are 1,2-propylene oxide and 3-methyltetrahydrofuran. Examples of the alcohol having an alkyl group in the side chain include neopentyl glycol, 1,3-butanediol, 3-methyl-1,5-pentanediol, and the like. As the liquid polytetrahydrofuran-based polyether polyol, a block copolymer, a random copolymer, or the like can be used without limitation, but a random copolymer is preferable because the low-temperature stability is better. In addition, the usage ratio of the alkylene oxide having an alkyl group in a side chain in the liquid polytetrahydrofuran-based polyether polyol is usually about 5 to 50% by weight, and more preferably 10 to 40%. When the use ratio of the alkylene oxide having an alkyl group in the side chain is 5% or more, the high-temperature stability and the low-temperature stability, which are the effects of the present invention, can be further improved. It is preferable because the film properties such as toughness of the obtained aqueous polyurethane resin can be improved. The number average molecular weight of the liquid polytetrahydrofuran-based polyether polyol is preferably about 500 to 5,000. By setting the number average molecular weight of the liquid polytetrahydrofuran-based polyether polyol to 500 or more, it is possible to prevent the film of the obtained aqueous polyurethane resin from becoming brittle. It is preferable because the heat resistance of the film can be improved and the blocking property can be improved.
[0009]
A high molecular weight polyol other than the liquid polytetrahydrofuran-based polyether polyol can be used in combination with the high molecular weight polyol component of the present invention. Examples of the high molecular weight polyol other than the polyol of the present invention include polyether polyols such as polymers such as ethylene oxide, propylene oxide, and tetrahydrofuran; ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, and 1,3- Propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, octanediol, 1,4-butyne Various known saturated or unsaturated low molecular weight glycols such as diol and dipropylene glycol, alkyl glycidyl ethers such as n-butyl glycidyl ether and 2-ethylhexyl glycidyl ether, and glycidyl ester versatate Glycidyl esters of monocarboxylic acids such as adipic acid, maleic acid, fumaric acid, phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, azelaic acid, sebacic acid, Polyester polyols obtained by dehydrating and condensing dibasic acids such as suberic acid or their corresponding acid anhydrides or dimer acids; polyester polyols obtained by ring-opening polymerization of cyclic ester compounds; other polycarbonate polyols And various known high-molecular-weight polyols generally used in the production of polyurethane resins, such as polybutadiene glycols, glycols obtained by adding ethylene oxide or propylene oxide to bisphenol A, and the like.
[0010]
When the polymer polyol component is a mixture of a liquid polytetrahydrofuran-based polyether polyol and another polymer polyol, the use ratio of the liquid polytetrahydrofuran-based polyether polyol in the high-molecular-weight polyol component is 30% by weight. The above is preferable because the high-temperature stability and low-temperature stability of the obtained aqueous polyurethane resin can be improved.
[0011]
Examples of the polyisocyanate compound which is one of the components of the aqueous polyurethane resin of the present invention include a diisocyanate compound. Specific examples of the diisocyanate compound include, for example, methylene diisocyanate, isopropylene diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene Linear aliphatic diisocyanates such as diisocyanate and dimer diisocyanate in which the carboxyl group of dimer acid is substituted with an isocyanate group; cyclohexane-1,4-diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-diisocyanate Cycloaliphatic diisocyanates such as (isocyanatomethyl) cyclohexane and methylcyclohexane diisocyanate; 4,4'-diphenyldiisocyanate Dialkyldiphenylmethane diisocyanate such as methylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate such as 4,4'-diphenyltetramethylmethane diisocyanate, 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane Aromatic diisocyanates such as diisocyanate, 4,4'-dibenzyl isocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, and m-tetramethyl xylylene diisocyanate; lysine diisocyanate Amino acid diisocyanate and the like. These polyisocyanate compounds including these diisocyanate compounds are used alone or in combination of two or more. Among these diisocyanate compounds, by using a chain aliphatic diisocyanate and a cyclic aliphatic diisocyanate, the weather resistance can be improved. The mixing ratio of the high molecular weight polyol and the polyisocyanate compound is determined based on the molar ratio of the active hydrogen group of the high molecular weight polyol to the NCO group of the polyisocyanate compound from the viewpoint of the drying property and blocking resistance of the obtained aqueous polyurethane. (Hereinafter referred to as an NCO group / active hydrogen group ratio) is preferably adjusted to be 1.1 / 1 or more, preferably 1.3 / 1 or more, and a film formed from the obtained aqueous polyurethane resin is hard. In order to prevent the ratio from becoming excessive, it is preferable to adjust the NCO group / active hydrogen group ratio to be 10/1 or less, more preferably 8/1 or less.
[0012]
Specific examples of the chain extender used in the present invention include, for example, low molecular weight glycols described in the section of the high molecular weight polyol; ethylenediamine, propylenediamine, hexamethylenediamine, triethylenetetramine, diethylenetriamine, isophoronediamine, dicyclohexyl. Amines such as methane-4,4'-diamine; 2-hydroxyethylethylenediamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, di- Diamine having a hydroxyl group in a molecule such as 2-hydroxypropylethylenediamine; dimer diamine in which a carboxyl group of dimer acid is replaced with an amino group, hydrazine, adipic acid Hydrazide and the like. These chain extenders are used alone or in combination of two or more. Among these chain extenders, it is preferable to use a chain extender having an ionic functional group in order to impart an ionic functional group to the polyurethane resin for the purpose of improving dispersibility in water. The ionic functional group is not particularly limited, and includes, for example, a quaternary amino base and a carboxyl group. Specific examples include N-methyldiethanolamine, N-ethyldiethanolamine, N-propyldiethanolamine, N-isopropyldiethanolamine, N-butyldiethanolamine, N-isobutyldiethanolamine, N-oleyldiethanolamine, N-stearyldiethanolamine, ethoxylated coconut oil amine, N-allyldiethanolamine, N-methyldiisopropanolamine, N-ethyldiisopropanolamine, N-propyldiisopropanolamine, N-butyldiisopropanolamine, dimethyldiethoxyhydrazine, propoxymethyldiethanolamine, N- (3-aminopropyl) -N-methylethanolamine, N, N'-bis (oxyethyl) propylenediamine, diethanolaminoacetate Alkoxylated chain aliphatic amines such as amide, diethanolaminopropionamide, N, N-bis (oxymethyl) semicarbazide; alkoxylated cyclic aliphatic amines such as N-cyclohexyldiisopropanolamine; N, N-diethoxyaniline; N, N-diethoxytoluidine, N, N-diethoxy-1-aminopyridine, N, N'-bis (2-hydroxyethyl) -N, N'-diethylhexahydro-p-phenylenediamine, N, N ' Alkoxylated aromatic amines such as -bis (oxyethyl) phenyl semicarbazide; alkoxylated heterocyclic amines such as N, N'-diethoxypiperazine and N-2-hydroxyethylpiperazine; N-methyl-N, N-bis (3 -Aminopropyl) amine, N- (3-aminopropyl) -N, N'- Methyl ethylenediamine, N, N'-bis (3-aminopropyl) -N, N'-dimethylethylenediamine, 2-methyl-2-[(N, N-dimethylamino) methyl] propane-1,3-diol, etc. Linear aliphatic amines; aromatic amines such as 2,6-diaminopyridine and p, p'-bis-aminomethyldibenzylmethylamine; N, N'-bis (3-aminopropyl) piperazine, N- (2 And heterocyclic amines such as (-aminoethyl) piperazine. Incidentally, the basic nitrogen having the chain extender, before dispersing the chain extender in water, or after dispersing the chain extender in water, chloride ion, sulfate ion, organic carboxylic acid of It is quaternized using a quaternizing agent such as an anion.
[0013]
The chain extender having a carboxyl group is used when introducing a carboxyl group into the obtained polyurethane resin, and specific examples thereof include, for example, glyceric acid, dioxymaleic acid, dioxyfumaric acid, tartaric acid, dimethylolpropionic acid, Aliphatic carboxylic acids such as dimethylolbutanoic acid, 2,2-dimethylolvaleric acid, 2,2-dimethylolpentanoic acid, 4,4-di (hydroxyphenyl) valeric acid, and 4,4-di (hydroxyphenyl) butyric acid Aromatic carboxylic acids such as 2,6-dioxybenzoic acid and the like; Further, the carboxyl group of the chain extender includes alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; ammonia; trimethylamine, triethylamine, triethanolamine, triisopropanolamine, N-methyldiethanolamine and N-ethyldiethanolamine. Neutralization with a neutralizing agent such as tertiary amines such as N-alkyldiethanolamine, N, N-dimethylethanolamine and N, N-dialkylethanolamine including N, N-diethylethanolamine. It may be. The chain extender may be used before dispersing the polymerization component in water, or may be used after dispersing the polymerization component in water.
[0014]
The amount of the chain extender is not particularly limited, but is preferably about 1 to 20% by weight of the polymerization component from the viewpoint of achieving both flexibility and toughness of a film formed from the obtained aqueous polyurethane resin. Is desirably adjusted to be 3 to 10% by weight.
[0015]
When the chain extender having the ionic functional group is used, the compounding amount is not particularly limited. For example, the basic nitrogen in the polyurethane resin having the basic nitrogen is 1 g of the resin solid content of the polyurethane resin. 3 × 10 ^-5 ~ 1.8 × 10 ^-3 It is preferable to adjust so as to be about gram equivalent. The amount of the chain extender having a carboxyl group, which is a chain extender having the ionic functional group, is not particularly limited, but, for example, the carboxyl group in the polyurethane resin having the carboxyl group may be used in the polyurethane resin. 3 × 10 for 1 g of resin solids ^-5 ~ 1.8 × 10 ^-3 It is preferable to adjust so as to be about gram equivalent.
[0016]
In the present invention, a chain length terminator can be used if necessary. Specific examples of the chain terminator include, for example, monoamines such as di-n-butylamine and diethanolamine; and monohydric alcohols such as ethanol and isopropanol. These chain terminators may be used alone or in combination of two or more. Used as a mixture.
[0017]
The amount of the chain terminator is not particularly limited, but from the viewpoint of facilitating the control of the molecular weight of the obtained aqueous polyurethane resin, about 0.1 to 5% by weight, preferably 0.5 to 5% by weight of the polymerization component. It is desirable to adjust so as to be 3% by weight.
[0018]
The aqueous polyurethane resin of the present invention is obtained by reacting these components by a known method, and the number average molecular weight of the aqueous polyurethane resin is usually about 5,000 to 100,000. As a method for improving the dispersibility of water-based polyurethane in water, a method of imparting an ionic functional group to an aqueous polyurethane resin obtained using a chain extender having an ionic functional group has been exemplified. It is effective that at least one of them is adopted. The aqueous polyurethane resin of the present invention can be obtained by reacting each of the above components, but is usually not isolated as an aqueous polyurethane resin, and is used as it is as an aqueous solution as a binder for printing ink. Hereinafter, the method for producing the printing ink binder by each method will be described.
[0019]
Specific examples of a method of dispersing an aqueous polyurethane resin having an ionic functional group obtained by a method of imparting an ionic functional group in water include, for example, a high molecular weight polyol containing a liquid polytetrahydrofuran-based polyether polyol, A polyisocyanate compound is copolymerized with a high molecular weight polyol and under conditions that the NCO groups of the polyisocyanate compound are excessive with respect to the active hydrogen groups of the hydride of the petroleum resin having the active hydrogen to form an NCO group at the end of the molecular chain. Is formed into a solution of an appropriate organic solvent, and a chain extender containing the chain extender having an ionic functional group and, if necessary, a chain terminator are added to the solution. And then quaternized or neutralized using the quaternizing agent or neutralizing agent. A method of removing an organic solvent if necessary after dispersing in water, a high molecular weight polyol containing a liquid polytetrahydrofuran-based polyether polyol, a polyisocyanate compound, a chain containing a chain extender having the ionic functional group After reacting the extender and, if necessary, the chain terminator in an appropriate organic solvent at once, quaternizing or neutralizing is performed using the quaternizing agent or neutralizing agent, and then dispersed in water. A method for removing an organic solvent as necessary after the reaction, a high molecular weight polyol containing a liquid polytetrahydrofuran-based polyether polyol, a polyisocyanate compound and a chain extender having the ionic functional group, a high molecular weight polyol, active hydrogen With respect to the hydride of the petroleum resin having and the active hydrogen group of the chain extender having the ionic functional group, The reaction is carried out in an appropriate organic solvent under the condition that the NCO group of the lysocyanate compound becomes excessive to form a prepolymer having an NCO group at the terminal of the molecule, and quaternized by using the quaternizing agent or neutralizing agent. After neutralization or neutralization, a method of dispersing in water, adding a chain extender and, if necessary, a chain terminator, and reacting the resultant, and then removing the organic solvent as necessary, may be mentioned.
[0020]
The organic solvent is not particularly limited, and a generally known organic solvent can be used. Specific examples of such organic solvents include aromatic solvents such as benzene, toluene and xylene; ester solvents such as ethyl acetate and butyl acetate; ketone solvents such as acetone, methyl ethyl ketone, diethyl ketone and methyl isobutyl ketone; Examples include amide solvents such as formamide; sulfoxide solvents such as dimethyl sulfoxide; ether solvents such as dimethyl ether and diethyl ether; alcohols such as isopropyl alcohol and ethanol; and N-methylpyrrolidone. These organic solvents are used alone or in combination of two or more.
[0021]
The binder for the printing ink thus obtained is subjected to milling and dispersion by adding a pigment and the like, and if necessary, an aqueous polyurethane resin, an aqueous polyamide resin, an aqueous acrylic ester different from those obtained in the present invention. A printing ink composition can be easily obtained by appropriately blending an aqueous resin such as a system copolymer salt, an aqueous styrene-maleic acid copolymer salt, and additives such as an antiblocking agent and a plasticizer. .
[0022]
The reason that the aqueous polyurethane resin obtained by the present invention is excellent in high-temperature stability and low-temperature stability is because of the hydrolysis resistance of the alkylene oxide chain mainly containing the polytetrahydrofuran skeleton and the crystal inhibition of the polytetrahydrofuran skeleton by copolymerization. It is considered.
[0023]
【The invention's effect】
According to the present invention, water-based polyurethane resin has flexibility, especially when used as a binder for printing ink, while having excellent adhesion to plastics such as nylon and polyester, high-temperature stability and low temperature. An aqueous polyurethane resin having excellent stability can be provided. In addition, the water-based polyurethane resin has excellent adhesion and blocking resistance, so that it can be used as a paint, glass shatterproof film, synthetic leather, artificial leather, nonwoven fabric, woven fabric, paper, wood, steel plate, rubber, leather, floor polish, glass It can also be suitably used as a fiber sizing agent, a coating agent such as an inkjet receiving layer, an adhesive, a pressure-sensitive adhesive, and the like.
[0024]
【Example】
Next, the aqueous polyurethane resin of the present invention will be described in more detail based on Examples, but the present invention is not limited to only these Examples.
[0025]
Example 1
In a reaction vessel equipped with a stirrer, a thermometer, a cooling pipe and a nitrogen gas introducing pipe, 59.4 parts of dimethylolbutanoic acid, PTG-L2000 (copolymer of tetrahydrofuran / 3-methyltetrahydrofuran = 85/15, Hodogaya Chemical 489.9 parts of a number average molecular weight of 2000 (manufactured by K.K.) and 200.8 parts of isophorone diisocyanate were charged and reacted at 85 ° C. for 5 hours under a nitrogen stream to obtain 750 parts of a urethane prepolymer having an isocyanate group end. Then, the urethane prepolymer was added and dispersed in an aqueous solution comprising 1208 parts of water, 225 parts of isopropyl alcohol, 40.5 parts of triethylamine and 43.3 parts of adipic dihydrazide with stirring, and reacted at 50 ° C. for 3 hours. I let it. The aqueous polyurethane resin dispersion thus obtained had a resin solid content concentration of 35%, a viscosity of 600 mPa · s / 25 ° C., and a pH of 8.0.
[0026]
Example 2
In a reaction vessel equipped with a stirrer, a thermometer, a cooling pipe and a nitrogen gas introduction pipe, 59.4 parts of dimethylolbutanoic acid, PPTG2000 (copolymer of tetrahydrofuran / 1,2-propylene oxide = 70/30, Hodogaya Chemical 489.9 parts of a number average molecular weight of 2000 (manufactured by K.K.) and 200.8 parts of isophorone diisocyanate were charged and reacted at 85 ° C. for 5 hours under a nitrogen stream to obtain 750 parts of a urethane prepolymer having an isocyanate group end. Then, the urethane prepolymer was added and dispersed in an aqueous solution comprising 1208 parts of water, 225 parts of isopropyl alcohol, 40.5 parts of triethylamine and 43.3 parts of adipic dihydrazide with stirring, and reacted at 50 ° C. for 3 hours. I let it. The aqueous polyurethane resin dispersion thus obtained had a resin solids concentration of 35%, a viscosity of 800 mPa · s / 25 ° C., and a pH of 8.0.
[0027]
Example 3
In a reaction vessel equipped with a stirrer, a thermometer, a cooling pipe and a nitrogen gas introducing pipe, 59.4 parts of dimethylolbutanoic acid, PTXG1800 (copolymer of tetrahydrofuran / neopentyl glycol, manufactured by Asahi Kasei Corporation, number average molecular weight 1800) ) 440.9 parts and isophorone diisocyanate 200.8 parts were charged and reacted at 85 ° C for 5 hours under a nitrogen stream to obtain 750 parts of a urethane prepolymer having an isocyanate group end. Then, the urethane prepolymer was added and dispersed in an aqueous solution consisting of 1117 parts of water, 225 parts of isopropyl alcohol, 40.5 parts of triethylamine and 43.3 parts of adipic dihydrazide with stirring, and reacted at 50 ° C. for 3 hours. I let it. The aqueous polyurethane resin dispersion thus obtained had a resin solid content concentration of 35%, a viscosity of 600 mPa · s / 25 ° C., and a pH of 8.0.
[0028]
Comparative Example 1
A reaction vessel equipped with a stirrer, thermometer, cooling pipe and nitrogen gas inlet pipe was charged with 59.4 parts of dimethylolbutanoic acid, 489.9 parts of polytetramethylene glycol having a number average molecular weight of 2000, and 200.8 parts of isophorone diisocyanate. The reaction was carried out at 85 ° C. for 5 hours under a nitrogen stream to obtain 750 parts of an isocyanate group-terminated urethane prepolymer. Then, the urethane prepolymer was added and dispersed in an aqueous solution comprising 1208 parts of water, 225 parts of isopropyl alcohol, 40.5 parts of triethylamine and 43.3 parts of adipic dihydrazide with stirring, and reacted at 50 ° C. for 3 hours. I let it. The aqueous polyurethane resin dispersion thus obtained had a resin solids concentration of 35%, a viscosity of 500 mPa · s / 25 ° C., and a pH of 8.0.
[0029]
Comparative Example 2
A reaction vessel equipped with a stirrer, thermometer, cooling pipe and nitrogen gas inlet pipe was charged with 59.4 parts of dimethylolbutanoic acid, 489.9 parts of polydiethylene adipate glycol having a number average molecular weight of 2000, and 200.8 parts of isophorone diisocyanate. The reaction was carried out at 85 ° C. for 5 hours under a nitrogen stream to obtain 750 parts of an isocyanate group-terminated urethane prepolymer. Then, the urethane prepolymer was added and dispersed in an aqueous solution comprising 1208 parts of water, 225 parts of isopropyl alcohol, 40.5 parts of triethylamine and 43.3 parts of adipic dihydrazide with stirring, and reacted at 50 ° C. for 3 hours. I let it. The aqueous polyurethane resin dispersion thus obtained had a resin solid content concentration of 35%, a viscosity of 650 mPa · s / 25 ° C., and a pH of 8.0.
[0030]
Each of the aqueous polyurethane resin dispersions obtained in Examples 1 to 3 and Comparative Examples 1 and 2 was evaluated for the following items. Table 1 shows the results.
[0031]
Stability at low temperature and high temperature: Mixtures of the following compositions were each kneaded with a paint shaker to prepare a blue printing ink.
15 parts phthalocyanine blue
Aqueous dispersion of polyurethane resin 50 parts
Isopropyl alcohol 5 parts
30 parts of ion exchange water
The obtained blue printing ink was allowed to stand for one week in an atmosphere of -10 ° C, and the flow state at a low temperature was observed. Further, the viscosity of the obtained blue printing ink was determined by Zahn Cup No. 3 (25 ° C.), and then allowed to stand in a 40 ° C. atmosphere for one week. 3 (25 ° C.) and measured again.
[0032]
Adhesion to plastic: The blue printing ink prepared with the above composition was applied to a corona-treated polypropylene film (OPP), polyethylene terephthalate film (PET), and nylon film (NY) with a bar coder (No. 4). ) And dried for 30 seconds with a heat gun. Next, an adhesive tape was applied to the coated surface, and the remaining state of the coating film when peeled off in a direction perpendicular to the coated surface was visually evaluated.
：: No peeling at all.
Δ: 50% or more remained.
X: Less than 50% remained.
[0033]
[Table 1]

Claims (7)

In an aqueous polyurethane resin comprising a high molecular weight polyol component, a polyisocyanate compound and a chain extender, the high molecular weight polyol component is obtained by copolymerizing tetrahydrofuran and an alkylene oxide having an alkyl group in a side chain or an alcohol having an alkyl group in a side chain. An aqueous polyurethane resin containing the obtained liquid polytetrahydrofuran-based polyether polyol. The aqueous polyurethane resin according to claim 1, wherein the liquid polytetrahydrofuran-based polyether polyol is a copolymer of tetrahydrofuran and 1,2-propylene oxide, or a copolymer of tetrahydrofuran and 3-methyltetrahydrofuran. The aqueous polyurethane resin according to claim 1 or 2, wherein the proportion of the alkylene oxide having an alkyl group in a side chain in the liquid polytetrahydrofuran-based polyether polyol is 5 to 50% by weight. The aqueous polyurethane resin according to any one of claims 1 to 3, wherein the proportion of the liquid polytetrahydrofuran-based polyether polyol in the high molecular weight polyol component is 30% by weight or more. The aqueous polyurethane resin according to any one of claims 1 to 4, which has an ionic functional group. A printing ink binder comprising the aqueous polyurethane resin according to claim 1. A printing ink composition comprising the printing ink binder according to claim 6.