JP2002275230A - Method for producing water-based urethane resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a water-based urethane resin composition allowing for environmental protection, good in productivity, excellent in physical properties including water resistance, and suitable as a binder for water-based printing inks. SOLUTION: This method for producing a water-based urethane resin composition comprises reaction between (A) a urethane prepolymer terminated with isocyanate groups and having carboxy groups on the side chain, (B) a chain extender and (C) a basic compound in (D) a reaction solvent; wherein the urethane prepolymer A to be used is (a) a urethane prepolymer soluble to (d) an alcohol-based solvent and such that >=70 mol% of the terminal isocyanate groups are bound to the carbon atoms of secondary and/or tertiary aliphatic hydrocarbons, the chain extender B to be used is (b) a polyamine having at least two amino groups each having an active hydrogen atom, and the reaction solvent D to be used is an aqueous solvent including the alcohol-based solvent d.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a resin for printing ink, particularly an aqueous urethane resin composition useful as a binder for gravure printing ink.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for binders and printing inks containing the binders, which are excellent in productivity as well as environmental protection on a global scale. For example, JP-A-9-286945, JP-A-10-2
JP-A-31342 and JP-A-10-279650
The publication discloses a urethane prepolymer having an isocyanate at a terminal and having a carboxyl group in a molecular side chain, a chain extender, and a basic compound such as triethylamine or ammonia, and a toxic compound such as acetone, toluene, and methyl ethyl ketone. A method for producing an aqueous urethane resin composition which is dispersed or dissolved in water by performing a reaction in a reaction solvent composed of a high organic solvent and neutralizing a carboxyl group is disclosed. However, these production methods use organic solvents such as acetone, toluene, and methyl ethyl ketone, which are highly toxic and have a risk of ignition.
It did not fully satisfy the consideration for environmental conservation.

[0003]

The problem to be solved by the present invention is to provide an aqueous urethane which is suitable for a binder for aqueous printing inks in consideration of environmental preservation, good productivity, excellent properties such as water resistance, and the like. An object of the present invention is to provide a method for producing a resin composition.

[0004]

Means for Solving the Problems As a result of intensive studies on the above-mentioned problems, the present inventors have found that a urethane prepolymer (A) having an isocyanate group at a terminal and a carboxyl group at a molecular side chain and the urethane prepolymer. Prepolymer (A)
A method of producing an aqueous urethane resin composition by reacting a chain extender (B) with a basic compound (C) in a reaction solvent (D), comprising the following steps (1) to (3): The present inventors have found that the above-mentioned problems can be solved by a manufacturing method that satisfies the conditions shown, and have completed the present invention.

(1) As the urethane prepolymer (A), at least 70 mol% of terminal isocyanate groups are isocyanate groups bonded to carbons of secondary and / or tertiary aliphatic hydrocarbons, and alcohol-based Solvent (d)
And (2) a polyamine (b) having two or more active hydrogen-containing amino groups as a chain extender (B) of the urethane prepolymer (A). (3) An aqueous solvent containing an alcoholic solvent (d) is used as the reaction solvent (D).

In the production method satisfying the conditions (1) to (3), an isocyanate group bonded to carbon of a secondary and / or tertiary aliphatic hydrocarbon of the urethane prepolymer (a) and an alcohol-based solvent are used. Since the reaction of the hydroxyl group in (b) is slow, synthesis of a urethane resin by a chain extension reaction between the urethane prepolymer (a) and the polyamine (b);
Urethane prepolymer (a) with basic compound (C)
Alternatively, neutralization of the carboxyl group in the urethane resin easily proceeds, and the obtained urethane resin is easily dispersed or dissolved in an aqueous medium containing an alcohol solvent (d) and water (E). An aqueous urethane resin composition having excellent physical properties such as water resistance and suitable as a binder for aqueous printing inks can be produced.

Further, in this manufacturing method, since it is not necessary to use a highly toxic organic solvent such as acetone, toluene, methyl ethyl ketone, etc., a solvent removing step which requires a long time is not required, the productivity is high, and environmental protection is high. It is valid.

Accordingly, the present invention provides a urethane prepolymer (A) having an isocyanate group at a terminal and a carboxyl group in a molecular side chain, and the urethane prepolymer (A)
A method for producing an aqueous urethane resin composition by reacting a chain extender (B) with a basic compound (C) in a reaction solvent (D). And, as a urethane prepolymer (A) having a carboxyl group in the molecular side chain, isocyanate groups in which 70 mol% or more of terminal isocyanate groups are bonded to carbons of secondary and / or tertiary aliphatic hydrocarbons, And (2) a polyamine having two or more amino groups having active hydrogen as a chain extender (B) of the urethane prepolymer (A) using a urethane prepolymer (a) soluble in an alcohol solvent (d). (B) and (3) an aqueous solvent containing an alcohol-based solvent (d) as a reaction solvent (D). It is intended to provide.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. In the present invention, the isocyanate group bonded to the carbon of the aliphatic hydrocarbon means an isocyanate group bonded to the carbon of the linear aliphatic hydrocarbon and an isocyanate group bonded to the carbon of the ring structure of the cycloaliphatic hydrocarbon, For example, an isocyanate group directly bonded to an isopropylene group bonded to a benzene ring, such as bis (1-isocyanate-1-methylethyl) benzene, is also an isocyanate group bonded to carbon of an aliphatic hydrocarbon. In addition, first grade, 2
The isocyanate group bonded to the carbon of the primary or tertiary aliphatic hydrocarbon means the isocyanate group bonded to the primary, secondary or tertiary carbon of the linear aliphatic hydrocarbon and the ring structure of the cyclic aliphatic hydrocarbon. Refers to isocyanate groups bonded to primary, secondary, and tertiary carbons.

The urethane prepolymer (a) used in the present invention is a linear urethane prepolymer having an isocyanate group bonded to the carbon of an aliphatic hydrocarbon at a terminal and a carboxyl group at a molecular side chain. 70 of the isocyanate groups bonded to the carbons of the aliphatic hydrocarbons
It is sufficient that at least mol% is an isocyanate group bonded to the carbon of the secondary and / or tertiary aliphatic hydrocarbon and that it is dissolved in an alcoholic solvent (d) described below to form a solution. Not limited. Among them, 85 mol% or more of the isocyanate groups bonded to the carbon of the terminal aliphatic hydrocarbon are secondary and / or tertiary.
A linear urethane prepolymer which is an isocyanate group bonded to carbon of a higher aliphatic hydrocarbon is preferable, and all of the isocyanate groups bonded to carbon of the terminal aliphatic hydrocarbon are secondary and / or tertiary aliphatic hydrocarbons. Particular preference is given to linear urethane prepolymers (a ') which are isocyanate groups bonded to hydrogen carbon.

In the urethane prepolymer, the proportion of the isocyanate groups bonded to the carbons of the secondary and / or tertiary aliphatic hydrocarbons among the isocyanate groups bonded to the carbons of the terminal aliphatic hydrocarbons is 70 mol%. If it is less than 3, the hydroxyl group of the alcohol-based solvent (d) easily reacts with the isocyanate group of the urethane prepolymer, and the molecular weight of the obtained urethane resin is reduced. It is not preferable because physical properties are deteriorated.

The urethane prepolymer (a) used in the present invention has, for example, a diol (a1) having a carboxyl group, another diol (a2), and two isocyanate groups bonded to carbons of an aliphatic hydrocarbon. A diisocyanate (a3) and, if necessary, a trivalent or higher polyol, wherein the terminal is an isocyanate group, and 70 mol% or more of the terminal isocyanate group is a secondary and / or tertiary aliphatic. It can be obtained by reacting in a composition or a reaction sequence that becomes an isocyanate group bonded to carbon of a hydrocarbon.

The acid value of the urethane prepolymer (a) is such that a urethane resin which can be easily dispersed or dissolved in an aqueous medium containing an alcohol solvent (d) and water (E) is obtained. It is preferably from 10 to 100 mgKOH / g, and particularly preferably from 20 to 80 mgKOH / g. For this reason, these diols (a1) having a carboxyl group and other diols (a
The weight ratio of (2) [(a1) / (a2)] is (1/1).
99) to (30/70), and particularly preferably (5/95) to (25/75).

The number-average molecular weight of the urethane prepolymer (a) is preferably from 800 to 30,000 because of its excellent solubility in the alcoholic solvent (d). It is particularly preferred that it is from 000 to 20,000.

In the present invention, the number average molecular weight refers to a number average molecular weight indicated by a value measured by gel permeation chromatography (GPC), and the numerical value is a value in terms of polystyrene.

The above-mentioned linear urethane prepolymer (a ') wherein all of the isocyanate groups bonded to the carbons of the terminal aliphatic hydrocarbons are isocyanate groups bonded to the carbons of the secondary and / or tertiary aliphatic hydrocarbons. Can be produced, for example, by using a diol having a carboxyl group (a
1), another diol (a2), and a diisocyanate (a3) having two isocyanate groups bonded to carbons of an aliphatic hydrocarbon with the diol (a1) with respect to the isocyanate group of the diisocyanate (a3). (A
After synthesizing a urethane prepolymer having hydroxyl groups at both ends by using a ratio in which the total of the hydroxyl groups in 2) becomes an excess in an equivalent ratio, the urethane prepolymer is added with secondary and / or tertiary aliphatic hydrocarbons. A method of reacting a diisocyanate (a3-1) having two isocyanate groups bonded to carbon, a diol having a carboxyl group (a
1), another diol (a2), and a diisocyanate (a3-1) having two isocyanate groups bonded to carbons of secondary and / or tertiary aliphatic hydrocarbons, with diol (a1) and ( For example, a method may be used in which the reaction is carried out by using an isocyanate group of the diisocyanate (a3-1) in an equivalent ratio excess with respect to the total of the hydroxyl groups of a2).

The diisocyanate (a3) having two isocyanate groups bonded to carbon of an aliphatic hydrocarbon used in the above-mentioned production method is, for example, an isocyanate group bonded to carbon of a primary aliphatic hydrocarbon. It is preferable to use two diisocyanates (a3-2), and the diisocyanate (a3-1) and the isocyanate (a3-2) may be used in a molar ratio of [(a3-1) / (a3-2). )] Is preferably 2/8 to 5/5. At this time, diisocyanate (a3
Instead of -2), diisocyanates (a3-3) having secondary and primary aliphatic isocyanate groups can also be used.

Examples of the diol having a carboxyl group (a1) used for producing the urethane prepolymer (a) include dimethylolpropionic acid, dimethylolbutanoic acid, dimethylolpentanoic acid, dimethylolbutyric acid, dimethylolvaleric acid, and the like. Is mentioned.

The other diol (a2) is preferably a polyether diol or a polyester diol.

As the polyether diol, for example,
Polyethylene glycol, polypropylene glycol,
Examples thereof include polyoxytetramethylene glycol, and copolymerized polyether diols thereof.

The polyester diol can be obtained, for example, by a condensation reaction between a dicarboxylic acid and a diol. Examples of the dicarboxylic acid include aliphatic dicarboxylic acids such as adipic acid, succinic acid, glutaric acid, maleic acid, and fumaric acid, and anhydrides thereof; phthalic acid, isophthalic acid, and aromatic carboxylic acids such as terephthalic acid; Or phthalic anhydride. Examples of the diol include ethylene glycol, propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butanediol, 2,3-butylene glycol, isobutylene glycol, neopentyl glycol, -Methyl-2-propyl-1,3-propanediol, 1,5-pentanediol, 1,6-hexanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,5 pentanediol, 2,2,4
-Trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2,5-methyl-2,5
-Hexanediol, 1,4-cyclohexanedimethanol, 1,4-butynediol, 1,4-butenediol, 2,5-dimethyl-3-hexyne-2,5-diol and the like.

Preferred examples of the polyester diol include a condensate of methylpentaneddiol and adipic acid, a condensate of neopentylglycol and adipic acid,
A condensate of 1,4-butanediol and adipic acid,
Condensates of 6-hexanediol and adipic acid, condensates of ethylene glycol and isophthalic acid, condensates of propylene glycol and isophthalic acid, condensates of methylpentanediole and terephthalic acid, etc. Is mentioned.

The polyester diol is, for example,
A lactone compound such as ε-caprolactone and β-methyl-δ-valerolactone and a diol compound such as a diol monomer, a polyester polyol, and a polyether are used in 15
It can also be obtained by heating and stirring at 0 to 250 ° C. Specific examples thereof include a polymer of ε-caprolactone and methylpentanediol, and a polymer of β-methyl-δ-valerolactone and 1,6-hexanediol.

The number average molecular weight of the other diol (a2) is from 300 to 5, because when used in an aqueous printing ink, the abrasion of the plate during high-speed printing is reduced and the ink adhesion can be kept good. 000 is preferred.

Among the diisocyanates (a3) having two isocyanate groups bonded to the carbon of the aliphatic hydrocarbon, the diisocyanates (a3-1) having two secondary and / or tertiary aliphatic isocyanate groups are as follows. A diisocyanate having an isocyanate group bonded to carbon of an aliphatic hydrocarbon having 9 to 17 carbon atoms is preferable, for example, isopropylidenebis-4-cyclohexyl diisocyanate, dicyclohexylmethane diisocyanate, methylcyclohexane diisocyanate,
1,2-bis (1-isocyanate-1-methylethyl) benzene, 1,3-bis (1-isocyanate-1)
-Methylethyl) benzene, 1,4-bis (1-isocyanate-1-methylethyl) benzene, and the like.

Examples of the diisocyanate (a3-2) having two isocyanate groups bonded to the carbon of the primary aliphatic hydrocarbon include hexamethylene diisocyanate, meta-xylylene diisocyanate,
2,4-trimethylhexamethylene diisocyanate,
And dimer acid diisocyanate.

Diisocyanates having an isocyanate group bonded to the carbons of secondary and primary aliphatic hydrocarbons (a3
Examples of -3) include isophorone diisocyanate and lysine diisocyanate methyl ester.

Examples of the polyamine (b) having two or more active hydrogen-containing amino groups in the present invention include diamines such as aliphatic diamines, alicyclic diamines and heterocyclic diamines, aliphatic triamines and alicyclic triamines. And triamines such as heterocyclic triamines. Among them, it is preferable to use a diamine having a lower basicity constant (Kb) (lower basicity) than the basic compound (D).
Among these diamines, a diamine having one or more hydroxyl groups in one molecule and a diamine having a polyether skeleton are preferable, and an alkanolamine having one to three hydroxyl groups in one molecule and one molecule in one molecule are preferable. Etheramines having 1 to 10 ether groups are particularly preferred.

Examples of the alkanolamine include, for example, aminoethylethanolamine, aminoethylisopropanolamine, aminoethylpropanolamine, aminoethylbutanolamine, aminoethylisobutanolamine, di- (2-hydroxyethyl) -ethylenediamine, di- (2-hydroxyethyl) -propylenediamine, di- (2-hydroxypropyl) -ethylenediamine, di- (2-hydroxypropyl) -ethylenediamine, 2,3-di-hydroxypropyleneethylenediamine, and the like.

Examples of the ether amine include polyoxyethylene diamine having a molecular weight of 104 to 2,000, including diethylene glycol diamine, triethylene glycol diamine, and tetraethylene glycol diamine; dipropylene glycol diamine, tripropylene glycol diamine, and tetrapropylene glycol. Polyoxypropylene diamine having a molecular weight of 132 to 2,000 containing diamine and the like; copolymer of these polyoxyethylene diamine and polyoxypropylene diamine; bis- (3-aminopropyl) -ether, 1,2-bis-
(3-aminopropoxy) -ethane, 1,3-bis-
(3-Amipropoxy) -2,2-dimethylpropane and the like.

These diamines can be used alone or in combination of two or more. If necessary, monoamines such as di-n-butylamine, diisobutylamine and 2-ethylhexylamine can be used in combination. .

The amount of the polyamine (b) used is as follows:
Terminal isocyanate group 1 of urethane prepolymer (a)
The amino group in polyamine (b) is 0.9 to the equivalent weight.
0 to 0.99 equivalents, preferably 0.93 to
The range is 0.97 equivalent.

The basic compound (C) used in the present invention includes, for example, ammonia or aqueous ammonia; tertiary amines such as trimethylamine, triethylamine, N, N-dimethylethano-amine and N, N-diethylethano-amine. Is mentioned. Among them, ammonia or aqueous ammonia is preferable because an aqueous printing ink having excellent drying properties can be obtained. The basic compound (C) may be one that can be used as the polyamine (b) as long as it neutralizes the carboxyl group of the urethane prepolymer (a). Can be used as a polyamine (b) and a basic compound (C), for example, in combination with a polyamine.

The amount of the basic compound (C) used is such that the urethane resin having a carboxyl group obtained by the reaction between the urethane prepolymer (a) and the polyamine (b) is hydrophilized to make the alcohol-based solvent (d) Any amount can be used so long as it can be dispersed or dissolved in an aqueous medium containing water and water (E).
It is used in a range of 3 to 1.0, preferably 0.6 to 1.0.

The aqueous solvent containing the alcoholic solvent (d) used in the present invention may be any aqueous solvent containing the alcoholic solvent (d). Alone, alcoholic solvent (d)
And a mixture of water (E).

Examples of the alcohol-based solvent (d) include those having 1 to 7 carbon atoms such as methanol, ethanol, normal propanol, isopropanol, normal butanol, isobutanol and tertiary butanol.
Aliphatic alcohols (d1); glycol ethers (d2) such as propylene glycol monomethyl ether, propylene glycol propyl ether, propylene glycol isopropyl ether, and propylene glycol monobutyl ether. Among these,
Water-soluble ones are preferable, and the aliphatic alcohol (d1) having 1 to 7 carbon atoms and the aliphatic alcohol (d1) 10
More preferably, glycol ether (d2) is used in a range of 50 parts by weight or less with respect to 0 parts by weight, and an aliphatic alcohol having 1 to 7 carbon atoms is particularly preferable.

In the method for producing the aqueous urethane resin composition of the present invention, at least 70 mol% of the terminal isocyanate groups are isocyanate groups bonded to carbons of secondary and / or tertiary aliphatic hydrocarbons, A urethane prepolymer (a) soluble in an alcoholic solvent (d), a polyamine (b) having two or more amino groups having active hydrogen, a basic compound (C), and water (E). Use
The urethane prepolymer (a), the polyamine (b) and the basic compound (C) in the presence of the alcohol solvent (d)
Is reacted in an aqueous solvent containing an alcoholic solvent (d) to disperse or dissolve in an aqueous medium containing an alcoholic solvent (d) and water (E). What is necessary is just a manufacturing method of an aqueous urethane resin composition. For example, a solution obtained by dissolving a urethane prepolymer (a) in an alcohol solvent (d) and a mixture of a polyamine (b), a basic compound (C) and water (E) are mixed to form a urethane prepolymer ( a) and a chain extension reaction of the polyamine (b), neutralization of the carboxyl group of the urethane prepolymer (a) with the basic compound (C), and conversion of the resulting urethane resin into an alcoholic solvent (d) and water (E). ), Or a method of dispersing or dissolving the same in an aqueous medium containing the following. More specifically, the following methods can be exemplified.

(1) A mixture of polyamine (b), basic compound (C) and water (E) is added to a solution obtained by dissolving urethane prepolymer (a) in alcoholic solvent (d) to react. And dispersing or dissolving the obtained urethane resin in an aqueous medium containing an alcohol solvent (d) and water (E).

(2) A solution obtained by dissolving the urethane prepolymer (a) in the alcoholic solvent (d) is added to a mixture of the polyamine (b), the basic compound (C) and the water (E), and the reaction is carried out. And dispersing or dissolving the obtained urethane resin in an aqueous medium containing an alcohol solvent (d) and water (E).

(3) After dissolving the urethane prepolymer (a) in the alcoholic solvent (d), a part or all of the carboxyl groups of the urethane prepolymer (a) are converted into a base in the presence of water (E). Aqueous medium containing an alcoholic solvent (d) and water (E) by neutralizing with a reactive compound (C) and then reacting by adding a polyamine (b) while stirring. Method of dispersing or dissolving in.

(4) After dissolving the urethane prepolymer (a) in the alcohol solvent (d), a part or all of the carboxyl groups of the urethane prepolymer (a) are neutralized with the basic compound (C). Then, the polyamine (b) is added and reacted while stirring in the presence of water (E), and the obtained urethane resin is added to an aqueous medium containing an alcohol solvent (d) and water (E). Dispersing or dissolving in water.

(5) The urethane prepolymer (a) is dissolved in an alcohol solvent (d), and then reacted with a polyamine (b) dissolved in the alcohol solvent (d) to form a carboxyl group-containing urethane resin. A basic compound (C) is added to neutralize a part or all of the carboxyl group, and the obtained urethane resin is placed in an aqueous medium containing an alcohol solvent (d) and water (E). A method of dispersing or dissolving.

(6) The urethane prepolymer (a) is dissolved in an alcohol solvent (d), and then reacted with a polyamine (b) dissolved in the alcohol solvent (d) to form a carboxyl group-containing urethane resin. A mixture of the basic compound (C) and water (E) is added to neutralize some or all of the carboxyl groups, and the resulting urethane resin contains an alcohol solvent (d) and water (E). Dispersing or dissolving in an aqueous medium.

(7) The urethane prepolymer (a) is dissolved in a mixture of the basic compound (C), the alcohol solvent (d) and the water (E), and the carboxyl group of the urethane prepolymer (a) is dissolved. A part or the whole is neutralized with the basic compound (C), and then the polyamine (b) is added and reacted, and the obtained urethane resin contains an alcohol solvent (d) and water (E). Dispersing or dissolving in an aqueous medium.

(8) The urethane prepolymer (a) is dissolved in a mixture of the polyamine (b), the basic compound (C), the alcohol solvent (d) and water (E), and the urethane prepolymer (a) is dissolved. Some or all of the carboxyl groups in the mixture are neutralized with a basic compound (C) and reacted with a polyamine (b), and the resulting urethane resin contains an alcohol solvent (d) and water (E). A method of dispersing or dissolving in an aqueous medium.

Among these manufacturing methods, (1) to (4)
Is preferred, and the production methods (1) and (2) are particularly preferred.

In the production method of the present invention, the urethane prepolymer (a) and the amino group having active hydrogen
The reaction temperature with the polyamine (b) having at least one
The temperature is 0 to 40 ° C, preferably 20 to 40 ° C. The reaction time of this reaction is usually 10 minutes or more, preferably 30 minutes to 6 hours, and the terminal isocyanate group of the obtained urethane resin is sealed with the alcohol-based solvent (d).

The urethane resin in the aqueous urethane resin composition obtained by the production method of the present invention has a number average molecular weight of 10,10 to maintain good adhesion and to prevent plate wear and print density from being lowered. It is preferably from 000 to 100,000, and particularly preferably from 20,000 to 60,000.

The aqueous printing ink using the aqueous urethane resin composition of the present invention includes, for example, the aqueous urethane resin composition of the present invention, a colorant, and if necessary, an alcohol solvent, water, a filler, an additive and the like. Are dispersed and mixed.

As the coloring agent used herein, for example, various coloring agents used in ordinary printing inks such as organic pigments, inorganic pigments and dyes can be used.

As the organic pigment, for example, carmine 6
B, lake red C, permanent red 2B, disazo yellow, pyrazolone orange, carmine FB, chromophthal yellow, chromophthal red, phthalocyanine blue, phthalocyanine green, dioxazine violet, quinacridone magenta, quinacridone red, indanthrone blue, pyrimidine yellow , Thioindigo bordeaux, thioindigo magenta, perylene red, perinone orange, isoindolinone yellow,
Aniline black, diketopyrrolopyrrole red, daylight fluorescent pigments and the like.

Examples of the inorganic pigments include carbon black, aluminum powder, bronze powder, chromium vermillion, graphite, cadmium yellow, cadmium red,
Ultramarine, navy blue, red iron oxide, yellow iron oxide, iron black, titanium oxide, zinc oxide and the like.

Examples of the dye include tartrazine lake, Rhodan 6G lake, Victoria Pure Blue lake, alkali blue G toner, brilliant green lake, and the like, and coal tar and the like can also be used.

Among them, it is preferable to use an organic pigment or an inorganic pigment from the viewpoint of water resistance and the like.

As the alcohol solvent, the alcohol solvent (c) used in the production of the aqueous urethane resin is used.
Can be used, and among them, ethanol, normal propanol and isopropanol are preferable.

Examples of the filler include those used in ordinary printing inks, such as carbonates such as calcium carbonate and magnesium carbonate; sulfates such as precipitated barium sulfate; silicates such as silica and talc. These can be used alone or in combination of two or more.

As additives, wax, pigment dispersant,
Defoamers and other various additives can be used.

In the aqueous printing ink using the aqueous urethane resin composition of the present invention, the mixing amounts of various raw materials are 5 to 30% by weight of a urethane resin (as solid content), 4 to 60% by weight of an alcoholic solvent, 10-70% by weight,
Colorants are preferably in the range of 0 to 55% by weight, fillers in the range of 0 to 20% by weight, and additives in the range of 0 to 10% by weight. Among them, 5 to 20% by weight of an aqueous urethane resin (as a solid content), It is particularly preferred that the amount is 50% by weight, the colorant is 5 to 50% by weight, the filler is 1 to 10% by weight, and the additive is 0.5 to 3% by weight.

Examples of the base material on which the aqueous printing ink is printed include absorbent base materials such as paper, non-absorbable base materials such as polyethylene, polypropylene, nylon, polyethylene terephthalate (PET), and polypropylene (PP). Substrates are included.

[0060]

Next, the present invention will be described more specifically with reference to examples and comparative examples. In the following, all parts and percentages are by weight unless otherwise specified.

Example 1 A 1-liter four-necked flask equipped with a stirrer, a thermometer, a Dimroth type reflux condenser, and a nitrogen gas inlet tube was charged with 200 parts of polypropylene glycol having a molecular weight of 2,000 and polyoxyethylene having a molecular weight of 1,000. Tetramethylene glycol 1
00 parts and dimethylolbutanoic acid (hereinafter referred to as DMBA
Called. ) 30 parts were charged, and the temperature was raised to 90 ° C while flowing and stirring nitrogen gas. Subsequently, 122 parts of 1,3-bis (1-isocyanate-1-methylethyl) benzene were added, and the mixture was reacted at 115 ° C. until the isocyanate group content (NCO%) reached 1.9%. And cooled to 75 ° C.
A solution of a linear urethane prepolymer having an isocyanate group bonded to carbon of a high-grade aliphatic hydrocarbon and having an acid value of 25.1 mgKOH / g was obtained.

Next, 842 parts of water, 11 parts of 25% aqueous ammonia and 11 parts of aminoethylethanolamine 9 were placed in a 2-liter four-necked flask equipped with a stirrer, a thermometer, a Dimroth-type reflux condenser, and a nitrogen gas inlet tube. Then, 0.4 parts of the mixture was charged, nitrogen gas was supplied, and the mixture was stirred at 25 ° C. Subsequently, 488 parts of the linear urethane prepolymer solution was added,
For 3 hours while stirring to obtain an aqueous urethane resin dispersion (X-1) in which the urethane resin was dispersed in an aqueous medium containing isopropyl alcohol.

Example 2 200 parts of a condensate of neopentyl glycol having a molecular weight of 2,000 and adipic acid was placed in a 1-liter four-necked flask equipped with a stirrer, a thermometer, a Dimroth reflux condenser and a nitrogen gas inlet tube. 100 parts of a condensate of methylpentanediol having a molecular weight of 1,000 and adipic acid, and DMB
A30 parts, charged with nitrogen gas, and stirred for 90 minutes.
The temperature was raised to ° C. Subsequently, 131 parts of dicyclohexylmethane diisocyanate was added, reacted at 115 ° C. until the isocyanate group content (NCO%) reached 1.8%, and 92 parts of isopropyl alcohol was added.
° C, has an isocyanate group bonded to carbon of a tertiary aliphatic hydrocarbon at both terminals, and has an acid value of 24.6 mg.
A solution of a linear urethane prepolymer of KOH / g was obtained.

Next, 856 parts of water, 11 parts of 25% aqueous ammonia and 11 parts of triethylene glycol diamine 12 were placed in a 2 liter four-necked flask equipped with a stirrer, a thermometer, a Dimroth type reflux condenser and a nitrogen gas inlet tube. Then, 6.6 parts of the mixture was charged, nitrogen gas was supplied, and the mixture was stirred at 25 ° C. Subsequently, 497 parts of the linear urethane prepolymer solution was added, and 35
The mixture was stirred and reacted at 3 ° C. for 3 hours to obtain an aqueous urethane resin dispersion liquid (X-2) in which the urethane resin was dispersed in an aqueous medium containing isopropyl alcohol.

Example 3 200 parts of polypropylene glycol having a molecular weight of 2,000 and polypropylene glycol having a molecular weight of 1,000 were placed in a two-liter four-necked flask equipped with a stirrer, a thermometer, a Dimroth reflux condenser and a nitrogen gas inlet tube. 100 parts and 30 parts of DMBA were charged, nitrogen gas was flown, and the temperature was raised to 90 ° C. while stirring. Subsequently, 58 parts of isopropylidenebis-4-cyclohexyl isocyanate was added,
Until the residual ratio of isocyanate groups reaches 0 mol%, 11
By reacting at 5 ° C., a prepolymer having hydroxyl groups at both ends was obtained. Subsequently, 1,3-bis (1-isocyanate-1-
Methylethyl) benzene (73 parts) was added at 115 ° C. until the isocyanate group content (NCO%) reached 1.8%.
Further, 92 parts of isopropyl alcohol is added, the mixture is cooled to 75 ° C., and has an isocyanate group bonded to carbon of a tertiary aliphatic hydrocarbon at both terminals, and has an acid value of 2
A solution of 4.6 mg KOH / g of linear urethane prepolymer was obtained. Next, 1049 parts of water and 25% ammonia water 1
A mixture of 2 parts of aminoethylethanolamine and 10.6 parts of aminoethylethanolamine was charged and reacted at 35 ° C. for 3 hours to obtain an aqueous urethane resin dispersion (X-3) in which the urethane resin was dispersed in an aqueous medium containing isopropyl alcohol. ) Got.

Example 4 A 2-liter four-necked flask equipped with a stirrer, a thermometer, a Dimroth-type reflux condenser, and a nitrogen gas inlet tube was charged with a condensate of methylpentanediole of 1,000 molecular weight and adipic acid. And 59 parts of DMBA, charged with nitrogen gas and heated to 90 ° C. while stirring. Subsequently, 134 parts of isophorone diisocyanate was added, and the mixture was heated at 100 ° C. until the isocyanate group content (NCO%) reached 0%.
To obtain a prepolymer having both ends hydroxyl groups. Subsequently, 49 parts of 1,3-bis (1-isocyanate-1-methylethyl) benzene was added and reacted at 115 ° C. until the isocyanate group content (NCO%) reached 1.55%. Further, 163 parts of isopropyl alcohol was added, the mixture was cooled to 75 ° C., and has an isocyanate group bonded to carbon of a tertiary aliphatic hydrocarbon at both terminals and an acid value of 4
A solution of 1.2 mg KOH / g linear urethane prepolymer was obtained. Next, 1041 parts of water and 25% ammonia water 2
A mixture of 5 parts and 9.9 parts of aminoethylethanolamine was charged and reacted at 35 ° C. for 3 hours to obtain an aqueous urethane resin solution (X-4) in which the urethane resin was dissolved in an aqueous medium containing isopropyl alcohol. Obtained.

Example 5 In the same manner as in Example 1, a solution of a linear urethane prepolymer having an isocyanate group bonded to the carbon of a tertiary aliphatic hydrocarbon at both terminals and further having a carboxyl group was obtained. .

Next, 812 parts of water and 12 parts of 25% aqueous ammonia were charged into a 2 liter four-necked flask equipped with a stirrer, a thermometer, a Dimroth type reflux condenser, and a nitrogen gas inlet tube. Flowed and stirred at 25 ° C. continue,
488 parts of the linear urethane prepolymer solution was added, and 3
The mixture was stirred at 5 ° C. for 15 minutes to obtain an aqueous dispersion of a linear urethane prepolymer. Further, 9 parts of aminoethylethanolamine was added and reacted at 35 ° C. for 3 hours to obtain an aqueous urethane resin dispersion (X-5) in which the urethane resin was dispersed in an aqueous medium containing isopropyl alcohol.

Example 6 In the same manner as in Example 3, a solution of a linear urethane prepolymer having an isocyanate group bonded to the carbon of a tertiary aliphatic hydrocarbon at both terminals and further having a carboxyl group was obtained. .

Next, 864 parts of water and 12 parts of 25% ammonia water were charged into a 2 liter four-necked flask equipped with a stirrer, a thermometer, a Dimroth type reflux condenser and a nitrogen gas inlet tube, and nitrogen gas was added. Flowed and stirred at 25 ° C. continue,
497 parts of the linear urethane prepolymer solution was added, and 3
The mixture was stirred at 5 ° C. for 15 minutes to obtain an aqueous dispersion of a linear urethane prepolymer. Further, 9 parts of aminoethylethanolamine was added and reacted at 35 ° C. for 3 hours to obtain an aqueous urethane resin dispersion (X-6) in which the urethane resin was dispersed in an aqueous medium containing isopropyl alcohol.

Comparative Example 1 200 parts of polypropylene glycol having a molecular weight of 2,000 and polypropylene glycol having a molecular weight of 1,000 were placed in a 1-liter four-necked flask equipped with a stirrer, a thermometer, a Dimroth type reflux condenser, and a nitrogen gas inlet tube. 100 parts and 30 parts of DMBA were charged, nitrogen gas was flown, and the temperature was raised to 80 ° C. while stirring. Subsequently, 112 parts of isophorone diisocyanate was added, and the isocyanate group content (N
CO%) reaches 1.9%, and is reacted at 100 ° C. to obtain a linear urethane prepolymer having isocyanate groups bonded to carbons of primary and secondary hydrocarbons at both ends and further having a carboxyl group. After that, 747 parts of methyl ethyl ketone and 320 parts of isopropyl alcohol were added to obtain a solution of a linear urethane prepolymer having an acid value of 25.7 mgKOH / g. Further, isophorone diamine 16
Then, the mixture was reacted at 40 ° C. for 3 hours to obtain a solvent-soluble urethane resin solution. Next, 13 parts of 25% aqueous ammonia was added, and 1,108 parts of water was further added to disperse the mixture in water. Then, methyl ethyl ketone and isopropyl alcohol were distilled off under heating and reduced pressure to obtain an aqueous urethane resin dispersion ( R
X-1) was obtained.

Comparative Example 2 A 1-liter four-necked flask equipped with a stirrer, a thermometer, a Dimroth type reflux condenser, and a nitrogen gas inlet tube was charged with 300 parts of polypropylene glycol having a molecular weight of 1,500 and DMBA30. Then, nitrogen gas was flowed, and the temperature was raised to 80 ° C. while stirring. Subsequently, 84 parts of hexamethylene diisocyanate was added, and the isocyanate group content (N
CO%) reaches 2.0% at 100 ° C. to obtain a linear urethane prepolymer having an isocyanate group bonded to carbon of a primary aliphatic hydrocarbon at both terminals and further having a carboxyl group. After that, 105 parts of acetone was added to obtain a solution of a linear urethane prepolymer having an acid value of 27.4 mgKOH / g.

Next, 851 parts of water and 18 parts of triethylamine were charged into a 2 liter four-necked flask equipped with a stirrer, a thermometer, a Dimroth-type reflux condenser, and a nitrogen gas inlet tube. Stirred at ° C. Subsequently, 373 parts of the linear urethane prepolymer solution was added, and 35
The mixture was stirred at 15 ° C. for 15 minutes to obtain an aqueous dispersion of a linear urethane prepolymer. Furthermore, 2.7 parts of hydrazine were added, and 40 parts were added.
After reacting at 3 ° C. for 3 hours, acetone was distilled off under reduced pressure under heating to obtain an aqueous urethane resin dispersion (RX-2).

The characteristic values of the resins obtained in the examples and comparative examples are shown in Tables 1 (1) and (2).

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[Table 1] Table 1 (1)

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[Table 2] Table 1 (2)

Footnotes in Tables 1 (1) and (2) Viscosity: The viscosity of the resin solution was measured at 25 ° C. using a B-type viscometer. Molecular weight: The number average molecular weight was calculated by measuring the molecular weight distribution in terms of polystyrene by GPC (THF solvent, 40 ° C.). Non-volatile content: 1 g of an aqueous urethane resin dispersion or solution was diluted with 5 g of isopropyl alcohol and dried at 107 ° C. for 2 hours, and the non-volatile content was calculated.

Applied Examples 1 to 6 and Comparative Comparative Examples 1 and 2 The compositions shown in Tables (1) and (2) were dispersed for 1 hour using a pigment disperser (paint shaker). Using a solvent having the composition shown in (1) and (2), Zahn Cup No. The viscosity was adjusted so that the viscosity at 3 was 18 seconds to prepare an aqueous printing ink. Using this aqueous printing ink, a polypropylene film was printed on a polypropylene film using a baby printing machine manufactured by Higashiya Iron Works Co., Ltd.
After drying for 2 seconds, the following evaluation test was performed. The results are shown in Tables 3 (1) and (2).

<Evaluation method> (1) Odor: Judgment was made based on the presence or absence of ketone or amine odor. Those with no ketone or amine odor were rated as ○, those with a slight ketone or amine odor were rated as Δ, and those with a ketone or amine odor were rated as x. (2) Hot water resistance: A two-component curable isocyanate-based adhesive was applied to the printed surface of the printed polypropylene film, and the polyethylene film was laminated with a laminator. The printed matter on which the film was laminated was immersed in hot water at 95 ° C. for 1 hour to evaluate the printed matter. The printed matter having the film laminated thereon did not change in appearance, ○ indicates that the printed matter obtained by laminating the film was partially peeled off, and x indicates that the printed matter obtained by laminating the film was completely peeled off. (3) Water resistance: 25 printed polypropylene films
The sample was immersed in water at 24 ° C. for 24 hours and evaluated. The appearance of the printed PP film having no change was evaluated as ○, the appearance of the printed PP film in which blisters occurred in one part was evaluated as Δ, and the appearance of the printed PP film in which blisters occurred was evaluated as ×. (4) Adhesion: A cellophane tape was attached to the printing surface, and the attached cellophane tape was peeled off and measured. ○: No peeling at all, △: Partially peeled, cellophane
What peeled off in width equal to or larger than the tape width was evaluated as x.

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[Table 3] Table 2 (1)

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[Table 4] Table 2 (2)

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[Table 5] Table 3 (1)

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[Table 6] Table 3 (2)

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The method for producing the aqueous urethane resin composition of the present invention uses an alcoholic solvent as an organic solvent, so that environmental protection is taken into consideration.
Excellent productivity because there is no solvent removal step. Moreover, the present invention can provide a water-based printing ink which is suitable for a water-based printing ink and has an excellent balance of properties such as hot water resistance, water resistance and adhesion.

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 4J034 BA08 CA02 CA04 CA15 CA16 CA22 CB03 CB04 CB07 CB08 CC03 CC08 DA01 DB04 DB07 DF01 DF16 DF20 DF21 DF22 DF24 DG03 DG04 DG06 HA01 HA07 HA18 HB12 HC03 HC12 HC17 HC22 HC46 HC46 HC71 HC73 JA15 JA30 JA42 JA43 LA01 LA36 MA12 MA14 QA07 QC05 RA07 4J039 AE04 CA06 EA38 EA45 GA03

Claims (7)

[Claims] 1. A urethane prepolymer (A) having an isocyanate group at a terminal and having a carboxyl group in a molecular side chain, a chain extender (B) of the urethane prepolymer (A), and a basic compound (C). Is reacted in a reaction solvent (D) to produce an aqueous urethane resin composition, comprising: (1) a urethane prepolymer (A) having an isocyanate group at a terminal and a carboxyl group at a molecular side chain. ) As 7 of the terminal isocyanate groups
(2) using a urethane prepolymer (a) in which 0 mol% or more is an isocyanate group bonded to carbon of a secondary and / or tertiary aliphatic hydrocarbon and is soluble in an alcohol solvent (d); As the chain extender (B) of the prepolymer (A), a polyamine (b) having two or more amino groups having active hydrogen is used, and (3) an alcohol solvent (d) is used as a reaction solvent (D). A method for producing an aqueous urethane resin composition, characterized by using an aqueous solvent containing: 2. The polyamine (b) having two or more amino groups having active hydrogen is a diamine having a smaller basicity constant (Kb) than the basic compound (D).
A method for producing the aqueous urethane resin composition as described above. 3. The urethane prepolymer (a ') is a linear urethane prepolymer (a') in which all of the terminal isocyanate groups are isocyanate groups bonded to carbons of secondary and / or tertiary aliphatic hydrocarbons. The method for producing an aqueous urethane resin composition according to claim 1 or 2, wherein 4. The method for producing an aqueous urethane resin composition according to claim 3, wherein the alcohol solvent (d) is an aliphatic alcohol having 1 to 7 carbon atoms. 5. The polyamine (b) having two or more amino groups having active hydrogen is a diamine having a hydroxyl group and / or a diamine having a polyether skeleton, and the alcohol-based solvent (d) has one carbon atom. The method for producing an aqueous urethane resin composition according to claim 4, which is an aliphatic alcohol of any one of (1) to (7). 6. The urethane prepolymer (a) has an acid value of 2
The method for producing an aqueous urethane resin composition according to claim 3, wherein the aqueous urethane resin composition is a linear urethane prepolymer of 0 to 80 mgKOH / g. 7. The urethane prepolymer (a) has an acid value of 2
The method for producing an aqueous urethane resin composition according to claim 4, which is a linear urethane prepolymer of 0 to 80 mgKOH / g.