JP2000313735A - Preparative method for aqueous dispersion of polyurethane resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a preparative method capable of preparing an aqueous dispersion of high molecular weight polyurethane resin without using an organic solvent such as acetone, methyl ethyl ketone, etc. SOLUTION: This method uses a diol compound including a high molecular weight polyol and a diisocyanate compound, and prepares a dispersion in the following processes, preparing an urethane prepolymer (B) having a polymerizable double bond in a molecule by reacting a part of the terminal isocyanate groups on an isocyanate terminated urethane prepolymer (A) including a carboxyl group, with a compound (a) of <=500 molecular weight having one or two hydroxyls and at least one polymerizable double bonds, neutralizing process for carboxyl group of the urethane prepolymer (B) by a basic compound, dilution process with a monoalcoholic solvent, a serial or simultaneous dispersing process to water, chain elongation process and polymerization process and inserting a dilution process before the dispersing process to water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing an aqueous polyurethane resin dispersion. The water-water-dispersible polyurethane resin obtained in the present invention includes various binders such as paints, magnetic paints, printing inks, and various kinds of artificial leather, plastic, glass, metal, wood, paper, floors, concrete, rubber, woven fabrics, and nonwoven fabrics. Base material coating or artificial leather,
It can be used as an adhesive for various materials such as plastic, glass, metal, wood, paper, floor, concrete, rubber, woven fabric and non-woven fabric.

[0002]

2. Description of the Related Art Polyurethane resins are characterized by having excellent flexibility and a wide range of adhesiveness to various substrates, and are widely used as various binders, various coating agents or various adhesives. In the past, such polyurethane resins were mainly of the solvent type dissolved in organic solvents, but in recent years, in order to respond to social trends such as resource saving, environmental protection, and tightening of regulations on organic solvents, the use of aqueous polyurethane resins has been promoted. Has become active, and in some cases, aqueous polyurethane resin dispersions have been put to practical use.

An aqueous polyurethane resin dispersion currently in practical use is, for example, a solution obtained by dissolving a urethane prepolymer in an organic solvent inert to isocyanate groups such as acetone and methyl ethyl ketone, while dispersing in water and elongating a chain. It is manufactured by doing. However, since it is not preferable that an organic solvent such as acetone or methyl ethyl ketone remains in the final product, the solvent is removed by a reduced pressure or the like at the final stage of the production. Therefore, such a production method has problems such as a longer production process, a lower yield, and a higher cost than the production method of a solvent-type polyurethane resin.

EP-A-1899 discloses a method for producing an aqueous dispersion of a polyurethane resin without using any organic solvent.
In Japanese Patent No. 45B2, Japanese Patent Nos. 2,655,525 and 2,726,679, a polyurethane is produced by using a monomer having an unsaturated bond such as an acrylic monomer instead of an organic solvent, and then the monomer is polymerized. We propose a way to make it happen. While these methods are excellent technologies in that they do not use any organic solvent, they require the use of a considerable amount of components other than polyurethane when they are put into practical use, so rubber elasticity, which is the inherent characteristic of polyurethane resins, is required. Or high elongation is likely to decrease.

Japanese Patent Application Laid-Open No. 11-12339 discloses a process for producing a polyurethane resin aqueous dispersion, in which a urethane prepolymer is produced without a solvent and then diluted with a monoalcohol-based solvent before an aqueous dispersion process is performed. A method of easily producing an aqueous dispersion of a polyurethane resin without using an organic solvent such as acetone or methyl ethyl ketone by providing the same is proposed. However, in such a method, since there is a limit in increasing the molecular weight of the polyurethane resin, the heat resistance and toughness of the obtained polyurethane resin are not sufficient, and the use of the polyurethane resin is sometimes limited.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been made without using an organic solvent such as acetone or methyl ethyl ketone.
Moreover, it is an object of the present invention to provide a method for producing an aqueous dispersion of a polyurethane resin having a high molecular weight.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, a part of the terminal isocyanate group is reacted with a compound having a polymerizable double bond to form an intramolecular compound. A neutralization step, a dilution step with a monoalcohol solvent, an aqueous dispersion step and a chain extension step are provided for a specific urethane prepolymer containing a polymerizable double bond, and a dilution step is arranged before the aqueous dispersion step. Then, it was found that the above problem could be solved by providing a polymerization step of a double bond, and the present invention was completed.

[0008] That is, the present invention relates to a method in which a isocyanate group-terminated urethane prepolymer (A) comprising a diol compound containing a high molecular polyol and a diisocyanate compound and having a carboxyl group is partially incorporated into the same molecule. A molecular weight of 50 having one or two hydroxyl groups and at least one polymerizable double bond
After producing a urethane prepolymer (B) having a polymerizable double bond in the molecule by reacting with a compound (a) of 0 or less, the urethane prepolymer (B) has a carboxyl group formed by a basic compound. Summing step, a step of diluting with a monoalcohol-based solvent, and an aqueous dispersing step and a chain elongating step to be performed sequentially or simultaneously, and a diluting step is arranged before the aqueous dispersing step. And a method for producing an aqueous polyurethane resin dispersion.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, first, an isocyanate group-terminated urethane prepolymer (A) comprising a diol compound containing a high molecular weight polyol and a diisocyanate compound, and containing a carboxyl group, is added one in the same molecule. A compound (a) having a molecular weight of 500 or less having two or more hydroxyl groups and at least one polymerizable double bond is reacted to produce a urethane prepolymer (B) having a polymerizable double bond in the molecule.

The high molecular polyol component includes polyether polyols such as polyethylene glycol, polypropylene glycol, polyoxytetramethylene ether glycol obtained by ring-opening polymerization of ethylene oxide, propylene oxide, tetrahydrofuran, etc .; ethylene glycol, diethylene glycol, triethylene glycol , 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol,
-Methyl-1,5-pentanediol, 1,6-hexanediol, octanediol, 1,4-butynediol, dipropylene glycol, bisphenol A, hydrogenated bisphenol A, and various other known low-molecular-weight saturated or unsaturated molecules. Glycols and adipic acid, maleic acid, fumaric acid, phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid,
Polyester polyols obtained by dehydrating and condensing dibasic acids such as azelaic acid, sebacic acid and suberic acid or acid anhydrides corresponding thereto; ε-caprolactone, β
Polyester polyols obtained by ring-opening polymerization of lactones such as -methyl-δ-valerolactone; and other known high molecular polyols generally used in the production of polyurethane, such as polycarbonate polyols and polybutadiene glycols. You. Among these high molecular polyols, polyether polyols which can lower the viscosity of the urethane prepolymer (B) and can be promptly dispersed in water as a dispersion medium in the aqueous dispersion step are suitable. In addition, glycerin, trimethylolpropane, trimethylolethane, 1,2,6-hexanetriol, 1,2,2
Various polyols such as 4-butanetriol, pentaerythritol and sorbitol can be substituted.

The number average molecular weight of the high molecular polyol is as follows:
Although not particularly limited, from the viewpoint of the film flexibility of the obtained polyurethane resin, it is usually preferably about 500 or more, more preferably 700 or more, and the water dispersibility of the urethane prepolymer (B) and the obtained polyurethane resin From the viewpoint of drying properties, it is preferably about 10,000 or less, more preferably 5,000 or less.

In the present invention, a carboxyl group-containing diol is usually used as a diol compound to introduce a carboxyl group into the urethane prepolymer (A). As the carboxyl group-containing diol, α, α′-
Dimethylolalkanoic acid (glyceric acid, dimethylolpropionic acid, dimethylolbutanoic acid, 2,2-dimethylolpentanoic acid, etc.), dioxymaleic acid, dioxyfumaric acid, tartaric acid, 2,6-dioxybenzoic acid, 4,4
-Bis (hydroxyphenyl) valeric acid, 4,4-bis (hydroxyphenyl) butyric acid and the like, and ε-caprolactone, γ
And those obtained by ring-opening polymerization of lactones such as -butyrolactone and γ-valerolactone. Such a carboxyl group-containing diol is usually used as a diol component for producing the urethane prepolymer (A) together with the polymer polyol. When the containing diol itself can be used as the polymer polyol, only the carboxyl group-containing diol can be used as the diol compound.

Further, as the diisocyanate compound,
Various known aromatic, aliphatic or alicyclic diisocyanates can be used. For example, 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl isocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3- Phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4- Trimethylhexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate Carboxyl groups of isophorone diisocyanate, lysine diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, methylcyclohexane diisocyanate, m-tetramethylxylylene diisocyanate and dimer acid were converted to isocyanate groups. A typical example is dimer diisocyanate.

In the production of the isocyanate group-terminated urethane prepolymer (A) having a carboxyl group, the diol compound and the diisocyanate compound are reacted so that the isocyanate group equivalent of the diisocyanate compound is greater than the hydroxyl equivalent of the diol compound. The reaction is
The reaction is performed in the absence of a solvent, and the reaction temperature, the reaction time, and the presence or absence of the urethanization catalyst may be appropriately determined according to the reactivity. In addition,
The amount of the carboxyl group-containing diol used in the diol compound is not particularly limited, but in order to obtain an aqueous dispersion of the polyurethane resin having good dispersion stability, the acid value in 1 g of the resin solid content of the polyurethane resin is 5 or more. It is preferable that the acid value be 100 or less from the viewpoint of the water resistance of the obtained polyurethane resin.

Next, the obtained urethane prepolymer (A) has a molecular weight of 500 having one or two hydroxyl groups and at least one polymerizable double bond in the same molecule.
A urethane prepolymer (B) having a polymerizable double bond in the molecule is produced by reacting the following compound (a).

The compound (a) includes 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, 4-hydroxy Butyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-hydroxy-3-acryloyloxypropyl methacrylate, glycerin dimethacrylate, glycerin methacrylate acrylate, trimethylolpropane diallyl ether, glycerin monomethacrylate, glycidol / acrylic acid adduct, Pentaerythritol triacrylate, pentaerythritol triallyl ether, polypropylene glycol Methacrylate (with a molecular weight of 500 or less), polyethylene glycol methacrylate (with a molecular weight of 500 or less), polycaprolactone acrylate (with a molecular weight of 500 or less), polycaprolactone methacrylate (with a molecular weight of 500 or less), 2-hydroxyethyl monovinyl ether , 4-
Hydroxybutyl monovinyl ether, N-methylol acrylamide and the like can be mentioned. Among them, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, in terms of easiness of polymerization in a later polymerization step, Glycerin monomethacrylate is preferred. These compounds (a) can be used alone or in combination of two or more.

The compound (a) has an isocyanate remaining at a terminal of the urethane prepolymer (B) obtained by reacting a part of the terminal isocyanate groups of the urethane prepolymer (A) with an extent capable of reacting with a chain extender. So that the amount used is appropriately adjusted. Usually, compound (a)
Is preferably used such that the equivalent ratio (-OH / -NCO) of the hydroxyl group (-OH) of the compound (a) and the isocyanate group (-NCO) of the urethane prepolymer (A) is 0.5 or less. .

The amount of the compound (a) used is such that the double bond equivalent of the urethane prepolymer (B) is 5,000 to 50,000 g.
/ Eq is preferably used. When the double bond equivalent is low, insolubles are likely to be generated in the subsequent polymerization step, and the filterability tends to deteriorate. Therefore, the double bond equivalent is more preferably 6000 g / eq or more. Further, when the double bond equivalent is increased, the high molecular weight conversion rate is reduced even after the subsequent polymerization step, and the improvement in heat resistance and the like of the obtained polyurethane resin tends to be reduced. Therefore, the double bond equivalent is 30,000 g. / Eq or less is more preferable. The amount of the compound (a) used is usually about 10% by weight or less, preferably 5% by weight or less, and more preferably 3% by weight or less of the obtained polyurethane resin. Is introduced into the polyurethane resin, the intrinsic physical properties of the polyurethane resin itself do not decrease.

Next, the obtained urethane prepolymer (B) is subjected to a step of neutralizing a carboxyl group with a basic compound, a step of diluting with a monoalcohol solvent, a step of sequentially or simultaneously dispersing in water, and a step of chain elongation. A process is provided to produce a polyurethane resin aqueous dispersion. The order of the steps is not particularly limited, except that the dilution step is arranged before the water dispersion step.

The urethane prepolymer is provided with a dilution step prior to the water dispersion step, because the urethane prepolymer (B), which has a remarkably high viscosity in a solvent-free state, is reduced in viscosity and the monoalcohol-based one is used. This is because the hydrophilicity of the solvent is used to promptly disperse in water as a dispersion medium in the aqueous dispersion step. In addition, the monoalcohol solvent,
This is because, unlike organic solvents such as acetone and methyl ethyl ketone, it is not necessary to remove the resulting polyurethane resin from the final product. It should be noted that a very high-viscosity urethane prepolymer (B) and water were quickly used without a dilution step before the water dispersion step or using a mixture of water and a monoalcohol-based solvent as a dispersion medium in the water dispersion step. Not homogeneously mixed, resulting in high molecular weight due to the reaction of water and isocyanate groups partially,
A stable polyurethane resin aqueous dispersion cannot be obtained.

There are various types of monoalcohol solvents used in the dilution step, but those having a solubility in water at 25 ° C. of 5% by weight or more are preferable for prompt dispersion in water.

As the monoalcohol solvent, a secondary or tertiary monoalcohol having a low reaction rate with the terminal isocyanate group in the urethane prepolymer is preferred. Further, as the monoalcohol-based solvent, a solvent having no active hydrogen which is reactive to an isocyanate group in addition to the alcoholic hydroxyl group is preferable. According to such a monoalcohol-based solvent, consumption of terminal isocyanate groups in the urethane prepolymer (B) in the dilution step is small, and the urethane prepolymers (B) are not linked to each other to increase the molecular weight. Any molecular design such as increasing the molecular weight of the polyurethane resin in the chain elongation step is possible, and it can be rapidly dispersed in water in the water dispersion step to obtain a stable polyurethane resin aqueous dispersion. .

Examples of the monoalcohol solvent satisfying the above conditions include isopropyl alcohol, isobutyl alcohol, sec-butyl alcohol, tert-butyl alcohol, sec-amyl alcohol, diacetone alcohol and the like.

The monoalcohol solvent used in the dilution step may be used alone or in combination of two or more. The amount of the solvent is not particularly limited, but is usually about 3% by weight based on the urethane prepolymer (B). More than 10% by weight is preferably used. In order to suppress the reaction between the terminal isocyanate group of the urethane prepolymer (B) and the hydroxyl group of the alcohol-based solvent, the amount is about 30% by weight or less, preferably about 25% by weight or less based on the urethane prepolymer. The temperature of the dilution step is
Although not particularly limited, the temperature is preferably set to 50 ° C. or lower in order to reduce the reaction rate between the isocyanate group in the urethane prepolymer (B) and the alcoholic hydroxyl group of the alcoholic solvent. The temperature of the dilution step is usually equal to or higher than normal temperature.

As described above, in the present invention, the dilution step is provided before the water dispersion step. However, the order of each step other than the dilution step, ie, the neutralization step, the water dispersion step and the chain elongation step which are performed sequentially or simultaneously is particularly important. Not restricted. Therefore, the neutralization step can be provided before or after the water dispersion step and the chain elongation step, which are performed sequentially or simultaneously, or together with the water dispersion step. However, in order to rapidly disperse the urethane prepolymer (B) in the aqueous dispersion step and obtain a stable polyurethane resin aqueous dispersion,
It is preferable to provide a neutralization step before the water dispersion step.
When a dilution step is provided after the neutralization step,
The reactivity between the isocyanate group in the urethane prepolymer (B) and the alcoholic hydroxyl group of the alcoholic solvent tends to be slow, which is preferable.

In the neutralization step, the basic compound used for neutralizing the carboxyl groups in the urethane prepolymer (B) includes alkali metals such as potassium hydroxide and sodium hydroxide, ammonia or trimethylamine, triethylamine, triethylamine and the like. Tertiary amines such as isopropylamine, tributylamine, triethanolamine, N-alkyldiethanolamine, and N, N'-dialkylmonoethanolamine. These basic compounds can be used alone or in combination of two or more. For the neutralization of the carboxyl group, usually, about 0.5 to 1.5 equivalents of a basic compound is used per 1 equivalent of the carboxyl group contained in the urethane prepolymer (B) (hereinafter, the neutralization ratio is 50%). ~ 150%). When the neutralization ratio is lower than 50%, the dispersion stability of the obtained aqueous dispersion of polyurethane resin is not sufficient,
If it is higher than 0%, the viscosity of the system when dispersed in water tends to increase. The temperature at which the neutralization is performed is not particularly limited, but is usually about 20 to 70 ° C.

When a neutralizing agent having a reactivity with an isocyanate group such as ammonia is used as a neutralizing agent, if a neutralizing step is provided before the dilution step, the neutralizing agent will react with the isocyanate group of the urethane prepolymer (B). And acts as a chain terminator to inhibit high molecular weight, so that it is used in the aqueous dispersion step provided after the dilution step so that the reaction amount between the neutralizing agent and the isocyanate group is minimized. It is preferable to take the following measures.

The water dispersing step is not particularly limited. For example, a method of adding water to a urethane prepolymer (B) diluted with an alcohol-based solvent and dispersing the same, or conversely, a method of dissolving the urethane prepolymer (B) diluted in water And a method of dispersing by adding the same.

The chain extension step is carried out with a chain extender and a chain terminator used as required. Examples of the chain extender include various known low-molecular glycols listed in the description of the polyester diol; ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine,
Isophoronediamine, dicyclohexylmethane-4,4
Amines such as'-diamine; carboxylic acid dihydrazides such as hydrazine and adipic dihydrazide; and water. In addition, 2-hydroxyethylethylenediamine, 2-hydroxyethylpropylenediamine,
Di-2-hydroxyethylethylenediamine, di-2-
Representative examples thereof include diamines having a hydroxyl group in a molecule such as hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, di-2-hydroxypropylethylenediamine; and dimerdiamine in which a carboxyl group of dimer acid is converted to an amino group. . Examples of the chain terminator include monoamines such as monobutylamine and dibutylamine;
Monoamines having a hydroxyl group such as ruamine and diethanolamine; and monoalcohols having a primary alcoholic hydroxyl group such as ethanol and n-butanol.

Since the water dispersing step and the chain elongating step are carried out sequentially or simultaneously, the chain elongating agent and optionally the chain terminator are added in advance to the water used for dispersing the urethane prepolymer (B) in water. May be
It may be added after the urethane prepolymer is dispersed in water. The chain length terminator may be added at the time of or after the aqueous dispersion of the urethane prepolymer, or may be added before or after the neutralization step or the dilution step.

Next, a polymerization step is provided for the obtained aqueous dispersion of polyurethane resin to polymerize a double bond in the polyurethane resin. In the polymerization step, a known radical polymerization method such as a method of performing polymerization in the presence of a polymerization initiator can be used. As the polymerization initiator, various water-soluble and oil-soluble azo compounds, organic peroxides, and inorganic peroxides can be used, and the amount of the polymerization initiator is 0.1 to 10 based on the compound (a).
What is necessary is just to determine suitably between about weight%. Further, the polymerization temperature may be appropriately determined generally at about 50 to 100 ° C.
The method of adding the polymerization initiator is not particularly limited.
A method of adding once or several times or a method of continuously dropping over 10 minutes to several hours can be adopted.

In the polymerization step, an unsaturated monomer copolymerizable with the compound (a) can be used in combination. These unsaturated monomers may be added during any of the steps up to the polymerization step as long as they have no reactivity with the isocyanate group, and may be added once or several times during the polymerization step. It can be added or continuously dropped over 10 minutes to several hours. Those having reactivity with the isocyanate group can be added in the same manner as those having no reactivity with the isocyanate group, after the chain extension step. In either case,
The combined amount of these unsaturated monomers is usually about 30% by weight or less, preferably 20% by weight or less of the obtained polyurethane resin together with the compound (a). As these unsaturated monomers, the above-mentioned compound (a) can be used. In addition, for example, acrylic acid, methacrylic acid, itaconic acid and methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, acrylic Lauryl acrylate, various acrylates such as stearyl acrylate and methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate,
Lauryl methacrylate, various methacrylates such as stearyl methacrylate and maleic acid, maleic acid monoesters, and styrene, α-methylstyrene, aromatic unsaturated monomers such as vinyltoluene, vinyl acetate, acrylonitrile, Acrylamide and the like.

Since the obtained polyurethane resin is provided with a polymerization step, the polyurethane resin has a higher molecular weight than the polyurethane resin before passing through the polymerization step. The weight average molecular weight of the obtained polyurethane resin is usually 10,000
About 500,000.

The solid content concentration and viscosity of the aqueous polyurethane resin dispersion of the present invention are not particularly limited, and may be appropriately determined in consideration of workability during use and the like. Usually, the solid content concentration is 15 to 60% by weight, and the viscosity is 10 to 100000 cps /
It is practically preferable to adjust the temperature to the range of 25 ° C.

When the aqueous polyurethane resin dispersion of the present invention is used for various purposes, water and, if necessary, various pigments are added to the aqueous polyurethane resin dispersion of the present invention in accordance with a known method. The binder, the coating agent, and the adhesive composition are prepared by mixing or dispersing and, if necessary, appropriately blending additives such as an antiblocking agent and a plasticizer.

[0036]

According to the production method of the present invention, an aqueous polyurethane resin dispersion having excellent reproducibility and stability can be easily produced without an inefficient solvent removal step. Further, it is possible to increase the molecular weight of the polyurethane resin without impairing physical properties such as rubber elasticity and high elongation inherent in the polyurethane resin. Polyurethane resin with high molecular weight is
It is excellent in heat resistance and toughness. For example, when the polyurethane resin is used as a binder for printing ink, the blocking resistance and the like of the printing ink can be improved.
When a neutralizing agent such as ammonia having a reactivity with an isocyanate group in the urethane prepolymer is used in the neutralization step in the production of the aqueous polyurethane resin dispersion, the neutralizing agent itself serves as a chain length terminator. Because of its function, it was difficult to increase the molecular weight of the polyurethane resin. However, according to the production method of the present invention, it is possible to increase the molecular weight of the polyurethane resin even when a neutralizing agent such as ammonia is used.

[0037]

EXAMPLES The present invention will be specifically described below with reference to Production Examples, Examples and Comparative Examples, but the present invention is not limited to these Examples. All parts and percentages are based on weight.

Example 1 A reaction vessel equipped with a stirrer, a thermometer, a cooling pipe and a nitrogen gas introducing pipe was charged with 26.4 parts of dimethylolbutanoic acid and polypropylene glycol 355.1 having a number average molecular weight of 2,000.
Then, dimethylolbutanoic acid was completely dissolved at 100 ° C. for 1 hour under a nitrogen stream. Then, after cooling to 85 ° C., 118.5 parts of isophorone diisocyanate was charged and reacted at 85 ° C. for 3 hours to obtain 500 parts of an isocyanate group-terminated urethane prepolymer. Then, 5.5 parts of 2-hydroxyethyl acrylate was charged,
The reaction was further performed at 85 ° C. for 2 hours to obtain a urethane prepolymer having a polymerizable double bond in the molecule (double bond equivalent: 10750 g / eq). Then, after adding 18 parts of triethylamine at 50 ° C. and neutralizing (neutralization rate 100%),
88.2 parts of tert-butyl alcohol was charged to obtain a uniform urethane prepolymer solution in tert-butyl alcohol. Next, 961.8 parts of water was added at 40 ° C. with stirring, and after dispersion, a mixture of 19.2 parts of isophoronediamine and 1.6 parts of diethylenetriamine was added with stirring, and the mixture was reacted at 40 ° C. for 3 hours. Thus, an aqueous dispersion of a polyurethane resin was obtained. This aqueous dispersion was heated to 75 ° C.
A solution of 0.2 part of 2,2'-azobis (2-amidinopropane) dihydrochloride in 49.8 parts of water was added to 3
It was added over 0 minutes to conduct radical polymerization, and further kept at 75 ° C. for 2 hours to complete the polymerization to obtain an aqueous dispersion A of a polyurethane resin. This aqueous dispersion A has a resin solid content concentration of 32%,
The viscosity is 1960 mPa · s / 25 ° C., the pH is 8.1,
The dried resin had a resin acid value of 19. Also,
The weight average molecular weight was 48,000.

Example 2 Into the same reaction vessel as in Example 1, dimethylolbutanoic acid 2 was added.
6.4 parts and 370.5 parts of polytetramethylene ether glycol having a number average molecular weight of 3000 were charged, and dimethylolbutanoic acid was completely dissolved in a nitrogen stream at 100 ° C. for 1 hour. Then, after cooling to 95 ° C., 103.1 parts of m-tetramethylxylylene diisocyanate were charged and reacted at 95 ° C. for 3 hours to obtain 500 parts of an isocyanate group-terminated urethane prepolymer. Then 2
-3.2 parts of hydroxyethyl acrylate, 9
The reaction was further performed at 5 ° C. for 2 hours to obtain a urethane prepolymer having a polymerizable double bond in the molecule (double bond equivalent: 18460 g / eq). Then, at 50 ° C., 18.0 parts of triethylamine was added and neutralized (neutralization ratio 100
%) And 50.0 parts of isopropyl alcohol to prepare a uniform urethane prepolymer isopropyl alcohol solution. Then, at 40 ° C., 976.3 parts of water were added with stirring, and after dispersion, a mixture of 4.9 parts of ethylenediamine, 1.1 parts of diethylenetriamine, and 0.4 parts of dibutylamine was added with stirring, and 40 parts of water were added. The mixture was reacted at a temperature of 3 ° C. for 3 hours to obtain an aqueous dispersion of a polyurethane resin. The temperature of the aqueous dispersion was raised to 80 ° C., and 0.2 parts of dimethyl-2,2′-azobisisobutyrate was added to isopropyl alcohol.
The solution dissolved in 2 parts was added over 30 minutes to perform radical polymerization, and further kept at 80 ° C. for 2 hours to complete the polymerization to obtain an aqueous dispersion B of a polyurethane resin. This aqueous dispersion B is
Resin solid content concentration 32%, viscosity 2400 mPa · s / 25
C., pH 8.1, and the dried resin had a resin acid value of 19. The weight average molecular weight was 7,000.

Example 3 Dimethylolbutanoic acid 3 was placed in the same reaction vessel as in Example 1.
3.0 parts, 162.9 parts of polypropylene glycol having a number average molecular weight of 2,000, and poly-3 having a number average molecular weight of 2,000
-Methylpentane adipate diol (162.9 parts) was charged, and dimethylolbutanoic acid was completely dissolved in a nitrogen stream at 100 ° C for 1 hour. After cooling to 95 ° C., m-tetramethylxylylene diisocyanate 14
1.2 parts were charged and reacted at 95 ° C. for 3 hours to obtain 500 parts of an isocyanate group-terminated urethane prepolymer. Then 2-hydroxyethyl acrylate 10.8
The mixture was further reacted at 95 ° C. for 2 hours to obtain a urethane prepolymer having a polymerizable double bond in the molecule (double bond equivalent: 5,500 g / eq). Next, 88.2 parts of tert-butyl alcohol was charged at 50 ° C. to prepare a uniform urethane prepolymer solution in tert-butyl alcohol. Then, a mixture of 13.5 parts of 28% aqueous ammonia and 821.3 parts of water was added with stirring at 40 ° C., neutralized (neutralization ratio: 100%), dispersed, and then 1.8 parts of ethylenediamine and diethylenetriamine were added. 6.9 parts were added to the mixture under stirring, and reacted at 40 ° C. for 3 hours.
An aqueous dispersion of a polyurethane resin was obtained. This aqueous dispersion is
The temperature was raised to 5 ° C., a solution prepared by dissolving 0.3 part of 2,2′-azobis (2-amidinopropane) dihydrochloride in 41.2 parts of water was added over 30 minutes, and radical polymerization was carried out. The polymerization was completed by keeping the polymerization for a while to obtain an aqueous dispersion C of a polyurethane resin. This aqueous dispersion C has a resin solid content concentration of 35%, a viscosity of 980 mPa · s / 25 ° C., and a pH of
7.6, and the dried resin had a resin acid value of 24. The weight average molecular weight was 65,000.

Example 4 Dimethylolbutanoic acid 2 was placed in the same reaction vessel as in Example 1.
6.4 parts and 345.2 parts of polytetramethylene ether glycol having a number average molecular weight of 2,000 were charged, and dimethylolbutanoic acid was completely dissolved at 100 ° C. for 1 hour under a nitrogen stream. Then, after cooling to 95 ° C., 128.4 parts of m-tetramethylxylylene diisocyanate were charged and reacted at 95 ° C. for 3 hours to obtain 500 parts of an isocyanate group-terminated urethane prepolymer. Then 2-
4.9 parts of hydroxyethyl acrylate and 4.5 parts of glycerin monomethacrylate were charged and reacted at 95 ° C. for another 2 hours to obtain a urethane prepolymer having a polymerizable double bond in the molecule (double bond equivalent). 7260 g /
eq). Then, at 50 ° C., isopropyl alcohol 10
0.0 parts was charged to obtain a uniform urethane prepolymer isopropyl alcohol solution. Then, a mixture of 10.8 parts of 28% aqueous ammonia and 812.5 parts of water was added to 4 parts.
After stirring at 0 ° C. for neutralization (neutralization rate 100%) and dispersion, a mixture of 11.7 parts of isophoronediamine and 2.9 parts of diethylenetriamine was added with stirring, and the mixture was stirred at 40 ° C.
For 3 hours to obtain an aqueous dispersion of a polyurethane resin. This aqueous dispersion was heated to 75 ° C.
A solution obtained by dissolving 0.2 part of 2′-azobisisobutyrate in 49.4 parts of isopropyl alcohol was added over 30 minutes to carry out radical polymerization, and further maintained at 75 ° C. for 2 hours to complete the polymerization, thereby obtaining water of polyurethane resin. Dispersion D was obtained. This aqueous dispersion D has a resin solid content concentration of 35% and a viscosity of 220 m.
Pa · s / 25 ° C., pH 7.5, and the dried resin had a resin acid value of 19. The weight average molecular weight was 92,000.

Example 5 Into the same reaction vessel as in Example 1, dimethylolbutanoic acid 2 was added.
9.7 parts, 181.0 parts of polypropylene glycol having a number average molecular weight of 3000, and 181.0 parts of polytetramethylene ether glycol having a number average molecular weight of 2,000 were charged.
Dimethylolbutanoic acid was completely dissolved at 100 ° C. for 1 hour under a nitrogen stream. Then, after cooling to 85 ° C, 108.4 parts of isophorone diisocyanate was charged, and 85
The reaction was carried out at 2 ° C. for 2 hours to obtain 500 parts of an isocyanate group-terminated urethane prepolymer. Then, 2.7 parts of 2-hydroxyethyl acrylate was charged and reacted at 85 ° C. for another 2 hours to obtain a urethane prepolymer having a polymerizable double bond in the molecule (double bond equivalent 2164).
0 g / eq). Next, 100.0 parts of isopropyl alcohol was charged at 50 ° C. to obtain a uniform urethane prepolymer isopropyl alcohol solution. Then, a mixture of 55.6 parts of 2-ethylhexyl methacrylate, 12.2 parts of 28% aqueous ammonia, and 907.9 parts of water was added at 40 ° C. with stirring to neutralize (neutralization rate 100%).
After dispersion, a mixture of 16.7 parts of isophoronediamine and 1.0 part of diethylenetriamine was added with stirring, and
The reaction was carried out at 0 ° C. for 3 hours to obtain an aqueous dispersion of a polyurethane resin. This aqueous dispersion was heated to 75 ° C.
A solution prepared by dissolving 0.2 part of 2,2′-azobisisobutyrate in 49.4 parts of isopropyl alcohol was added over 30 minutes to carry out radical polymerization, and further maintained at 75 ° C. for 2 hours.
The polymerization was completed to obtain an aqueous dispersion E of a polyurethane resin. This aqueous dispersion E has a resin solid content concentration of 35% and a viscosity of 4%.
It was 50 mPa · s / 25 ° C., pH 7.5, and the dried resin had a resin acid value of 20.5. The weight average molecular weight was 125,000.

Comparative Example 1 To 500 parts of the isocyanate group-terminated prepolymer obtained in Example 1 was neutralized by adding 18 parts of triethylamine at 50 ° C. without modification with 2-hydroxyethyl acrylate (neutralization). Rate 100%), tert
88.2 parts of -butyl alcohol was charged to obtain a uniform urethane prepolymer solution in tert-butyl alcohol. Then, at 30 ° C., 1013.0 parts of water was added with stirring, and after dispersion, a mixture of 19.2 parts of isophoronediamine, 1.6 parts of diethylenetriamine, and 6.1 parts of di-n-butylamine was stirred. In addition, the mixture was reacted at 40 ° C. for 3 hours to obtain an aqueous dispersion F of a polyurethane resin. This aqueous dispersion F had a resin solid content of 32% and a viscosity of 2800 mP.
a · s / 25 ° C., pH 8.2, and the dried resin had a resin acid value of 19. In addition, the weight average molecular weight was 35,000.

Comparative Example 2 To 500 parts of the isocyanate-terminated prepolymer obtained in Example 2 was neutralized by adding 18 parts of triethylamine at 50 ° C. without being modified with 2-hydroxyethyl acrylate (neutralization). (100%) and 88.2 parts of isopropyl alcohol to prepare a uniform urethane prepolymer isopropyl alcohol solution. Then, at 40 ° C., 977.0 parts of water were added with stirring, and after dispersion,
4.9 parts of ethylenediamine and diethylenetriamine
A mixture of 1 part of di-n-butylamine and 4.0 parts of di-n-butylamine was added under stirring, and reacted at 40 ° C. for 3 hours to obtain an aqueous dispersion G of a polyurethane resin. This aqueous dispersion G has a resin solid content concentration of 32%, a viscosity of 3000 mPa · s / 25 ° C.,
The pH was 8.1 and the dried resin had a resin acid value of 19. The weight average molecular weight was 50,000.

Comparative Example 3 508.2 parts of the isocyanate-terminated prepolymer obtained in Example 3 was charged with 88.2 parts of tert-butyl alcohol at 50 ° C. without being modified with 2-hydroxyethyl acrylate. A uniform urethane prepolymer solution in tert-butyl alcohol was obtained. Then, a mixture of 13.5 parts of 28% aqueous ammonia and 864.7 parts of water was added with stirring at 40 ° C., neutralized (neutralization ratio: 100%), dispersed, and then 1.8 parts of ethylenediamine and diethylenetriamine were added. 6.9 parts, di-n-butylamine 1
A mixture of 2.0 parts was added with stirring and reacted at 40 ° C. for 3 hours to obtain an aqueous dispersion H of a polyurethane resin. This aqueous dispersion H has a resin solid content of 35% and a viscosity of 1%.
440 mPa · s / 25 ° C., pH 7.7, and the dried resin had a resin acid value of 24. The weight average molecular weight was 29000.

Comparative Example 4 509.4 parts of the isocyanate group-terminated prepolymer obtained in Example 4 were not modified with 2-hydroxyethyl acrylate or glycerin monoacrylate, and 149.4 parts of isopropyl alcohol was added at 50 ° C. It was charged to obtain a uniform urethane prepolymer isopropyl alcohol solution. Then, 28% ammonia water10.
A mixture of 8 parts of water and 814.5 parts of water was added with stirring at 40 ° C., and neutralized (neutralization rate: 100%). After dispersion, 16.7 parts of isophoronediamine and 2.9 of diethylenetriamine were added.
And 5.4 parts of di-n-butylamine were added under stirring and reacted at 40 ° C. for 3 hours to obtain an aqueous dispersion I of a polyurethane resin. This aqueous dispersion I has a resin solid content concentration of 35%, a viscosity of 410 mPa · s / 25 ° C., and a pH of
7.7, and the dried resin had a resin acid value of 19. The weight average molecular weight was 54,000.

Comparative Example 5 509.4 parts of the isocyanate group-terminated prepolymer obtained in Example 5 were charged with 149.4 parts of isopropyl alcohol at 50 ° C. without being modified with 2-hydroxyethyl acrylate. An isopropyl alcohol solution of the urethane prepolymer was obtained. Then 2-
A mixture of 12.2 parts of 28% aqueous ammonia and 805.1 parts of water without addition of ethylhexyl methacrylate was added at 40 ° C. with stirring to neutralize (neutralization rate 100%).
After dispersion, a mixture of 16.6 parts of isophoronediamine and 1.0 part of diethylenetriamine was added with stirring, and
The mixture was reacted at 0 ° C. for 3 hours to obtain an aqueous dispersion J of a polyurethane resin. This aqueous dispersion J has a resin solid content concentration of 35%,
The viscosity was 320 mPa · s / 25 ° C., the pH was 7.5, and the dried resin had a resin acid value of 22. The weight average molecular weight was 45,000.

With respect to the aqueous dispersions A to J of the polyurethane resins obtained in Examples 1 to 5 and Comparative Examples 1 to 5, the following items were evaluated.

Film physical properties: Aqueous dispersions A to J of a polyurethane resin were poured into a horizontally placed mold, and after drying the water, a No. 2 dumbbell mold prepared from a dried film obtained by further subjecting to a reduced pressure treatment. Using a test piece, a tensile test was performed using Tensilon. Table 1 shows the results.

[0050]

[Table 1]

Blocking resistance: A mixture having the following composition was kneaded with a paint shaker to prepare a blue printing ink. 15 parts of phthalocyanine blue Aqueous dispersion of polyurethane resin A-J 50 parts 5 parts of isopropyl alcohol 30 parts of ion-exchanged water 30 parts of these blue printing inks on a commercial stretched polypropylene (OPP) film with a bar coater (No. 6) Colored and dried with a heat gun for 30 seconds. After drying, a stretched polypropylene film that is not colored with ink is attached to the ink surface of each colored material, and 0.5 MPa
After the film was left at 50 ° C. for 15 hours under a load of, the film was peeled off and judged according to the following criteria. Table 2 shows the results. ：: The films are peeled off without resistance. Δ: There is resistance when the films are peeled from each other, but the ink is not taken on the film on the side where the ink is not spread. X: There is a feeling of resistance when the films are peeled off from each other, and a part of the film on the side where the ink is not spread is taken.

[0052]

[Table 2]

Storage elastic modulus: Aqueous dispersions A to J of a polyurethane resin are poured into a horizontally placed mold, and after water is dried, a test piece prepared from a dried film obtained by further subjecting to reduced pressure treatment is used. The storage elastic modulus was measured using a dynamic viscoelasticity measuring device in the range of −110 to 150 ° C. The results are shown in FIG. 1, FIG. 2, FIG. 3, FIG. 4, and FIG.

[Brief description of the drawings]

FIG. 1 shows the storage elastic modulus of a film obtained from the aqueous polyurethane resin dispersion obtained in Example 1 and Comparative Example 1 corresponding to a temperature change.

FIG. 2 shows the storage elastic modulus corresponding to a temperature change of a film obtained from the aqueous polyurethane resin dispersion obtained in Example 2 and Comparative Example 2.

FIG. 3 shows the storage elastic modulus corresponding to a temperature change of a film obtained from the aqueous polyurethane resin dispersion obtained in Example 3 and Comparative Example 3.

FIG. 4 shows the storage elastic modulus corresponding to the temperature change of a film obtained from the aqueous polyurethane resin dispersion obtained in Example 4 and Comparative Example 4.

FIG. 5 shows the storage elastic modulus corresponding to a temperature change of a film obtained from the aqueous polyurethane resin dispersion obtained in Example 5 and Comparative Example 5.

Continued on the front page F-term (reference) 4J027 AG03 AG04 AG05 AG09 AG12 AG14 AG15 AG23 AG24 AG27 AJ01 AJ04 BA01 BA04 BA05 BA06 BA07 BA10 BA12 BA13 BA14 CB02 CB03 CB09 CC02 CD08 CD09 4J034 BA08 CA02 CA04 CA22 CB01 CC05 CC03 CC03 CC03 CC05 DA01 DB04 DC02 DC43 DC50 DF01 DF02 DF12 DF16 DF20 DF21 DF22 DG03 DG04 DG06 DG08 DP19 FA02 FB01 FC01 FD01 FE04 GA62 HA01 HA02 HA07 HA11 HC03 HC12 HC13 HC17 HC22 HC46 HC52 HC61 HC64 HC71 HC73 JA02 KB04 JA32 LA04 LB01 QA03 QA07 QC05 RA07 RA08

Claims (4)

[Claims] 1. An isocyanate group-terminated urethane prepolymer (A) comprising a diol compound containing a high molecular weight polyol and a diisocyanate compound and containing a carboxyl group, wherein one or two or more terminal isocyanate groups are contained in the same molecule. After producing a urethane prepolymer (B) having a polymerizable double bond in the molecule by reacting with a compound (a) having a molecular weight of 500 or less having at least one hydroxyl group and at least one polymerizable double bond, The urethane prepolymer (B) is provided with a step of neutralizing a carboxyl group with a basic compound, a step of diluting with a monoalcohol solvent, and a water dispersion step and a chain extension step performed sequentially or simultaneously, and before the water dispersion step. In which a dilution step is arranged, and then a double bond polymerization step is provided. A method for producing an aqueous dispersion of a polyurethane resin. 2. The method for producing a polyurethane resin aqueous dispersion according to claim 1, wherein the double bond equivalent of the urethane prepolymer (B) is 5,000 to 50,000 g / eq. 3. A compound (a) having one or two hydroxyl groups and at least one polymerizable double bond in the same molecule, is selected from the group consisting of 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and 2-hydroxyethyl methacrylate. The method for producing a polyurethane resin aqueous dispersion according to claim 1 or 2, wherein the polyurethane resin aqueous dispersion is at least one selected from the group consisting of propyl acrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, and glycerin monomethacrylate. 4. The method for producing an aqueous dispersion of a polyurethane resin according to claim 1, wherein an unsaturated monomer copolymerizable with the compound (a) is copolymerized in the polymerization step.