JPH11279237A - Aqueous resin and ink using the resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily produce the subject resin having excellent weather resistance and alkali resistance in contrast with conventional urethane resins without using ordinary synthetic solvents by dispersing a polyurethane produced in the absence of solvent in water under specific condition and radically polymerizing the obtained aqueous dispersion. SOLUTION: A polyurethane having a number-average molecular weight of <=30,000 is produced by reacting a polyol with an organic polyisocyanate without using a solvent. The polyurethane is dispersed in water in the presence of a hydroxyl-containing organic solvent (preferably a solvent containing isopropyl alcohol) and an unsaturated monomer and the obtained aqueous dispersion of the polyurethane solution is radically polymerized. A stable dispersion is produced by using polyethylene glycol as the polyol. The amount of the hydroxyl-containing organic solvent is preferably 1-50 wt.% based on the polyurethane. The amount of the unsaturated monomer is preferably selected to give a water-based resin having a polyurethane content of 5-95 wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous resin comprising a radical polymer of urethane and an unsaturated monomer, and an ink using the resin. The aqueous resin obtained by the present invention provides a coating film having excellent weather resistance, solvent resistance, and adhesion, is useful in the fields of paints, inks, adhesives, and particularly inks, and can be used widely. It is.

[0002]

2. Description of the Related Art Urethane resins have excellent adhesiveness to substrates, abrasion resistance, impact resistance, and solvent resistance.
It is widely used in paper, plastics, films, metals, textiles, etc. as inks, adhesives, and various coating agents. Conventionally, aqueous urethane resins such as emulsions, colloidal dispersions, and water-soluble urethane resins have been developed mainly by synthesis with acetone, methyl ethyl ketone, n-methylpyrrolidone, an aromatic organic solvent and the like, and after a solvent removal process (Progress in). Organic C
coatings, 9, 281, 1981). These aqueous urethane resins are superior to conventional oil-based urethane resins in use and handling.However, in the production thereof, the above-mentioned organic solvent is used. Problems such as solvent reuse and incineration disposal have newly arisen. Insufficient desolvation causes film formation,
There was a possibility that the physical properties of the coating film might be impaired.

[0003] Urethane resins have properties not found in other resins as described above, but are still insufficient from the point of versatility of use as paints, inks, and adhesives, for example, weather resistance and alkali resistance. In terms of heat resistance, it is inferior to other resins. As a method for compensating for these drawbacks, a composite with another resin has been attempted. For example, JP-A-60-550
As disclosed in Japanese Unexamined Patent Application Publication No. 64-164, and Japanese Patent Application Laid-Open No. 5-117611, there is a blend of a urethane resin and an acrylic resin. However, in this system, there are problems such as stability over time due to blending of both emulsions and phase separation at the time of film formation because both resins are not chemically bonded. JP-A-6-8
No. 0930 discloses emulsion polymerization of acrylic in the presence of an aqueous urethane resin. This method is an excellent method for compounding a urethane resin and an acrylic resin, and although improvement in physical properties can be expected, an organic solvent is used when synthesizing the urethane resin, and the aqueous solution is obtained by removing the solvent as described above. There are environmental pollution, health and safety issues. As means for solving these problems, for example, Japanese Unexamined Patent Publication No.
Japanese Patent Publication No. 138211 discloses a method of synthesizing a polyurethane in an acrylic monomer instead of an organic solvent to form a composite. However, this method has a drawback that the ratio of the urethane resin is reduced or a special stirrer is required because the viscosity is significantly increased in the chain extension reaction. In addition, there was a problem in water dispersibility due to high viscosity, and it was difficult to easily obtain a composite resin.

[0004]

As described above, in the prior art, the step of removing the solvent is always required in the production of the aqueous urethane resin, and the time and cost required for the step are problematic. At the same time, weather resistance, a disadvantage of urethane resin,
A water-based urethane composite resin with improved alkali resistance could not be easily obtained. For this reason, it is possible to omit the desolvation step in the production process, and moreover, an aqueous urethane resin which overcomes the drawbacks of the conventional urethane resin has been strongly demanded in the fields of paints, inks and adhesives. .

In the present invention, an aqueous resin comprising an aqueous urethane composite resin having excellent weather resistance and alkali resistance, which is a drawback of the conventional urethane resin, is prepared by using a conventional synthetic solvent such as a ketone type, pyrrolidone type or aromatic type. The present invention provides an ink which can be easily produced without performing the above-mentioned process and uses the aqueous resin.

[0006]

Means for Solving the Problems The present inventors have made intensive efforts to solve the above-mentioned problems, and as a result, they have no problems in environment, health and safety, and have excellent weather resistance and alkali resistance. An aqueous resin comprising a urethane composite resin and an ink using the resin have been obtained.

Various problems in the conventional method for producing an aqueous urethane resin, particularly, a urethanization reaction in the absence of a solvent and a chain elongation reaction with an amine were examined. 1) An increase in viscosity when no urea bond is present in the urethane resin. 2) When the aqueous dispersion is carried out in the presence of an organic solvent having a hydroxyl group, a stable aqueous dispersion can be easily obtained. Aqueous urethane composite resin which is easier to disperse in water and radically polymerizes the unsaturated monomer later, which is a disadvantage of the conventional urethane resin, has been found to be excellent in weather resistance, alkali resistance and heat resistance. .

[0008] That is, the first invention comprises a) a first step of reacting a polyol with an organic polyisocyanate in the absence of a solvent to obtain a polyurethane (A) having a number average molecular weight of 30,000 or less b) (A) A second step of dispersing in water in the presence of an organic solvent having a hydroxyl group and an unsaturated monomer to obtain an aqueous dispersion (B) of a polyurethane solution c) an aqueous solution obtained from the third step of radically polymerizing (B) Resin.

The second invention is the aqueous resin according to the first invention, wherein the polyurethane has an ionizable dissociable group in the first step. A third invention is the aqueous resin according to the first invention, wherein the polyurethane contains polyethylene glycol as an essential component in the first step.
A fourth invention is the aqueous resin according to the first invention, wherein the organic solvent having a hydroxyl group in the second step contains isopropyl alcohol. A fifth invention is the aqueous resin according to the first invention, wherein the polyurethane content in the resin solid content of the aqueous resin obtained in the third step is 5 to 95% by weight.

A sixth invention is an ink containing the aqueous resin according to any one of the first invention to the fifth invention.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION In the production of an aqueous urethane composite resin, the reaction between a polyol and an organic polyisocyanate in the absence of a solvent is preferably carried out by dissolving the polyol in advance and dropping the polyisocyanate. The urethanization reaction is preferably performed at 50 to 100 ° C. for 1 to 20 hours in the presence of a catalyst. The end point of the reaction can be confirmed by NCO% measurement and disappearance of the NCO peak by IR measurement.

The polyol used in the first step preferably has two or more hydroxyl groups in one molecule. For example, low molecular weight polyols include dihydric alcohols such as ethylene glycol, diethylene glycol, trimethylene glycol, triethylene glycol, propylene glycol, butylene glycol, hexamethylene glycol, and neopentyl glycol. Examples include trihydric alcohols such as trimethylolethane, trimethylolpropane, glycerin, pentaerythritol, and sorbitol.

[0013] Examples of higher molecular weight polyols include polyether polyols, polyester polyols, acrylic polyols, epoxy polyols and the like. Polyether polyols include polyethylene glycol, polyoxypropylene glycol, poly (ethylene / propylene) glycol, and polytetramethylene glycol. As the polyester polyol, there is a polyester formed by polycondensation of a diol and a dibasic acid. As the diol, in addition to the above-mentioned ethylene glycol and diethylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, and dibasic acids as adipic acid, azelaic acid,
Sebacic acid, isophthalic acid and terephthalic acid. In addition, polycaprolactone, poly β-methyl-δ
Lactone ring-opening polymer polyols such as valerolactone, polycarbonate diols and the like. Examples of the acrylic polyol include a copolymer of a monomer having a hydroxyl group. Examples of the hydroxyl group-containing monomer include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl acrylate, and dihydroxy acrylate, and examples of the epoxy polyol include an amine-modified epoxy resin. Other examples include polybutadiene diol and castor oil.

These polyols can be used alone or in combination. In order to balance the adhesion to the object to be coated, the paintability, the physical properties of the coating film, and the like, it is generally necessary to use two or more kinds having different chemical structures in combination or to appropriately select the molecular weight thereof. In addition, it is necessary to select a polyol also from the viewpoint of viscosity. For example, when a polyester polyol or polyether polyol which is a versatile polyol is used, its molecular weight is 5,000.
If it is 0 or more, a high temperature is required for dissolution, or urethanization reaction becomes difficult due to thickening. Even if the polyol has two or more active hydrogens, it becomes a branched structure, so that the problem of thickening is likely to occur. When polyethylene glycol is used alone or in combination with other diols, the diol can be easily made water-soluble, and a stable dispersion or hydrosol can be obtained.

When a polyol having an ionizable group such as a carboxyl group or a sulfone group is used as the diol component, a self-emulsifiable polyurethane can be obtained. As the carboxyl group-containing polyol, dimethylol propionic acid, 2,2-dimethylol acetic acid, 2,2-
Dimethylol butyric acid, 2,2-dimethylolpentanoic acid,
Examples include dimethylolalkanoic acid such as dihydroxypropionic acid, dihydroxysuccinic acid, and dihydroxybenzoic acid. Particularly, dimethylolpropionic acid and 2,2-dimethylolbutyric acid are preferred from the viewpoint of reactivity and solubility.

The organic polyisocyanate includes aromatic, aliphatic and alicyclic polyisocyanates. For example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, lysine diisocyanate , Isophorone diisocyanate, trimethylhexamethylene diisocyanate, 1,4-cyclohexylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, 3,3'-dimethoxy-4, 4'-
Buphenylene diisocyanate, 3,3'-dichloro-4,4'-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, and the like can be used alone or in a mixture.

The catalyst used for the reaction between the isocyanate and the hydroxyl group includes dibutyltin dilaurate, tin octoate, dibutyltin di (2-ethylhexoate),
Lead 2-ethylhexoate, 2-ethylhexyl titanate, iron 2-ethylhexoate, cobalt 2-ethylhexoate, zinc naphthenate, cobalt naphthenate, tetra-n-butyltin, stannous chloride, Stannic chloride,
Iron chloride.

In the reaction in the absence of a solvent, the solution viscosity generally becomes higher than that of a solvent system, so it is important to keep the molecular weight of the polyurethane within a specific range. When the number average molecular weight of the polyurethane is 30,000 or more, the viscosity is remarkably increased or the reaction takes a long time.

As the organic solvent having a hydroxyl group used in the second step, known organic solvents can be used. For example, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol monoisobutyl ether, Ethylene glycol mono-n-hexyl ether,
Diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monoisobutyl ether, diethylene glycol mono-n-hexyl ether, 2,2,4-trimethylpentanediol-1,3-monoisobutyrate (Texanol, Eastman Chemical Is used alone or in combination. The use of such an organic solvent having a hydroxyl group lowers the solution viscosity and provides a stable aqueous dispersion. By appropriately selecting such an organic solvent as a film-forming and coating aid suitable for paints, inks, adhesives, coatings, and the like, it is possible to omit the desolvation step accompanying aqueous conversion. Among the organic solvents having a hydroxyl group, an organic solvent containing isopropyl alcohol is desirable from the viewpoint of lowering the viscosity or functioning as a film-forming or coating aid. In the second step, an organic solvent having no hydroxyl group can be used in combination as needed. What is the amount of the organic solvent having a hydroxyl group? It is preferably in the range of 1% by weight to 50% by weight based on the polyurethane. 1
If it is less than 10% by weight, the viscosity of the polyurethane is not sufficiently reduced and it is difficult to disperse in water. If the content is 50% by weight or more,
Residual solvents tend to be a problem.

The unsaturated monomer used in the second step may be an unsaturated monomer having no active hydrogen or an unsaturated monomer having active hydrogen. Examples of the unsaturated monomer having no active hydrogen include unsaturated monomers containing no carboxyl group, hydroxyl group, methylol group, silanol group, primary or secondary amino group, and the like. For example, (meta)
Methyl acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, (meth) acryl (Meth) such as 2-ethylhexyl acrylate, octyl (meth) acrylate, nonyl methacrylate, lauryl (meth) acrylate, methoxyethyl (meth) acrylate, methoxybutyl (meth) acrylate, and ethoxybutyl (meth) acrylate A) alkyl acrylate; unsaturated monomers having an epoxy group such as glycidyl (meth) acrylate and allyl glycidyl ether; acrylamide, N-butoxymethyl (meth) acrylamide, N-
Unsaturated monomers having an amide group such as methylacrylamide, N, N-dimethylacrylamide, N-isopropylacrylamide; N, N-dimethylaminoethyl methacrylate, N, N-diethylaminoethyl methacrylate, N, N-dimethylaminopropyl (Meth) acrylic acid having a tertiary amino group such as methacrylate; nitrogen-containing unsaturated monomer such as N-vinylpyrrolidone, N-vinylimidazole, N-vinylcarbazole; cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate And alicyclic (meth) acrylates such as isobornyl (meth) acrylate; aromatic unsaturated monomers such as styrene, α-methylstyrene, and phenyl methacrylate; vinyltriethoxysilane, γ-methacryloyloxypropyltrimethoxysilane Unsaturated silicon-containing monomers such as orchids; unsaturated monomers such as fluorinated unsaturated monomers such as octafluoropentyl (meth) acrylate and perfluorocyclohexyl (meth) acrylate, and unsaturated monomers blocking isocyanate groups There are monomers having one group. Further, bifunctional unsaturated monomers such as divinylbenzene and polyethylene glycol di (meth) acrylate can also be used.

The unsaturated monomers having active hydrogen include:
Unsaturated monomers having a carboxyl group such as (meth) acrylic acid, itaconic acid and crotonic acid; 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth)
(Meth) acrylic esters having a hydroxyl group such as acrylate and 4-hydroxybutyl acrylate; and N-methylol (meth) acrylamide. In the case of polyurethane having an NCO group at a terminal, a part of the hydrophilic unsaturated monomer reacts with the urethane chain terminal, and it becomes possible to form a complex through a chemical bond with the unsaturated monomer in a later step.
In selecting an unsaturated monomer, it is necessary to dissolve the polyurethane well. If the solubility is poor, use monomers that have high solubility in urethane resins such as vinylpyrrolidone, or monomers that are relatively soluble in urethane such as aromatic unsaturated monomers. You can also.

The amount of the unsaturated monomer used is preferably adjusted so that the polyurethane content in the solid content of the aqueous composite resin is in the range of 5% by weight to 95% by weight. If the polyurethane content is 5% by weight or less, it is difficult for urethane to exhibit characteristics such as adhesion to a substrate, abrasion resistance, solvent resistance, and rebound resilience. On the other hand, when the content is 95% by weight or more, it is difficult to obtain weather resistance and the like, which are characteristics of unsaturated monomers.

When the polyurethane in the second step is dispersed in water in the presence of an organic solvent and an unsaturated monomer, it is preferable to introduce a water-soluble functional group into the urethane resin in advance. As the method, 1) a highly water-soluble polyol,
For example, a method using polyethylene glycol, 2) using a carboxyl group-containing diol as a diol component,
Neutralization with a base, 3) prepolymerization with an alkyl dialkanolamine having a tertiary amino group and quaternization, 4) prepolymerization with an alkyl dialkanol amine having a tertiary amino group, and And an amine salt. If there is an ionizable dissociating group in the urethane resin, it can be easily dispersed in water, and the storage stability of the finally obtained aqueous composite resin is improved. At this time, if a water-soluble polyol is also used in combination, further water dispersibility,
Storage stability can be improved. In the present invention, it is preferable not to use a surfactant, but the stability of the aqueous dispersion of the unsaturated monomer solution of the polyurethane, or the polymerization stability of the composite resin dispersion obtained by polymerizing the dispersion. A small amount of a surfactant may be used in combination for the purpose of improvement.

The basic compound used for aqueous conversion includes sodium hydroxide, potassium hydroxide, ammonia,
Methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, ethanolamine, propanolamine, diethanolamine, N
-Methyldiethanolamine, dimethylamine, diethylamine, triethylamine, N, N-dimethylethanolamine, 2-dimethylamino-2-methyl-1-propanol, 2-amino-2-methyl-1-propanol, morpholine and the like; , Used in mixing. These basic compounds, polyurethane, organic solvent,
It can be added before, during or after the addition of the unsaturated monomer. When neutralizing the unsaturated monomer solution of the polyurethane, it is necessary to appropriately select a neutral compound because the compatibility with the solution and the stability after dispersion in water may differ depending on the type of the basic compound. In neutralizing a compound having a carboxyl group such as dimethylolalkanoic acid, the amount is preferably 0.6 to 1.2 equivalents per equivalent of the carboxyl group.

Examples of the surfactant include a fatty acid salt, an alkyl sulfate salt, an alkylbenzene sulfonate,
Anionic surfactants such as naphthalene sulfonate and alkyl sulfosuccinate; polyoxyethylene alkyl ether, polyoxyethylene alkyl ester,
There are nonionic surfactants such as polyoxyethylene alkylphenyl ether and polyoxyethylene alkylphenyl ester. It is also possible to use a reactive activator in combination to suppress a decrease in water resistance.

In the aqueous dispersion, the total amount of the polyurethane and the unsaturated monomer is preferably within a range of 70% by weight or less based on the total amount. If it is more than 70% by weight, aggregates are easily formed, and it is difficult to obtain a uniform polymer. As a method for dispersing the unsaturated monomer solution of polyurethane in water, it is possible to disperse the aqueous solution using a usual stirrer. In order to obtain a stable aqueous dispersion, forcible dispersion under a high shearing force using a homomixer, a homogenizer, or a microfluidizer (manufactured by Mizuho Industry Co., Ltd.) is preferable.

In order to polymerize the aqueous dispersion in the third step to obtain a composite resin dispersion, a known radical polymerization method is preferred. As the polymerization initiator, both a water-soluble initiator and an oil-soluble initiator can be used. When using the oil-soluble initiator, it is preferable to dissolve it in advance in the unsaturated monomer solution of the polyurethane. These polymerization initiators are suitably used in the range of 0.05 to 5% with respect to the unsaturated monomer. Temperature is 4
0 ° C to 100 ° C is preferred, and 80 ° C for a redox initiator.
The following is sufficient. As the polymerization initiator, azobisisobutyronitrile, azobisisobutylvaleronitrile,
Azo compounds such as benzoyl peroxide, isobutyryl peroxide, octanoyl peroxide, cumyl peroxy octate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxy acetate, lauryl peroxide, Organic peroxides such as -t-butyl peroxide and di-2-ethylhexylperoxyzine carbonate; and inorganic peroxide compounds such as potassium persulfate, ammonium persulfate and hydrogen peroxide. Organic or inorganic peroxide compounds can also be used as redox initiators in combination with reducing agents. Examples of the reducing agent to be used include L-ascorbic acid, L-sorbic acid, sodium metabisulfite, ferric sulfate, ferric chloride, Rongalit and the like.

With respect to the method of polymerizing the unsaturated monomer, a method in which the entire amount is charged, the entire amount is dripped, or a part is charged and the rest is dropped is possible. In the polymerization of unsaturated monomers, a known chain transfer agent for the purpose of adjusting the molecular weight,
For example, octyl mercaptan, lauryl mercaptan,
It is also possible to use 2-mercaptoethanol, tercharddecyl mercaptan, thioglycolic acid, and the like.

The aqueous resin of the present invention is particularly useful for inks, but can also be used for paints and adhesives. For inks, the aqueous resin is contained in an amount of 3% by weight or more based on the solid content of the ink.
Desirably, the content is 80% by weight. If it is 3% by weight or less, the adhesiveness to the film is poor, and if it is 80% by weight or more, the coloring and hiding properties are poor.

The ink of the present invention may optionally contain other resins, for example, acrylic resin, polyester resin, amino resin, polyurethane resin, epoxy resin, etc.
In addition, it is possible to appropriately add a dispersing aid, an antifoaming agent, a thickener, a surfactant, an ultraviolet absorber, a light stabilizer, and an organic solvent according to the use. Further, depending on the purpose, a crosslinking agent can be added to improve water resistance, film strength and chemical resistance. Examples of the crosslinking agent include a blocked isocyanate compound, an oxazoline compound, a carbodiimide compound, an aziridine compound, and an epoxy compound. The ink containing the aqueous urethane composite resin thus obtained can be widely applied to films and papers.

[0031]

EXAMPLES The present invention will be described in detail below with reference to examples based on resins obtained in production examples, but the present invention is not limited to these examples. In the following production examples and examples,
Unless otherwise specified, “parts” means parts by weight.

Production Example 1 A four-necked 2000 ml flask equipped with a reflux condenser, a dropping funnel, a gas inlet tube, a stirrer, and a thermometer was replaced with dry nitrogen, and the number average molecular weight was about 1,500 (hydroxyl value: 76). Of polytetramethylene glycol, 28.5 parts of polyethylene glycol having a number average molecular weight of 1,000 (hydroxyl value: 111), and 27.0 parts of dimethylolpropionic acid, and the temperature was raised to 60 ° C. Under stirring, 77.9 parts of isophorone diisocyanate and 0.08 part of dibutyltin dilaurate were added, the temperature was raised to 80 ° C., and the mixture was reacted for 5 hours to obtain a polyurethane having a number average molecular weight of about 8,500. .

Polyurethane is added to isopropyl alcohol 30
Parts, 12 parts of butyl acrylate and 8 parts of methyl methacrylate, and the mixture was sufficiently stirred. Ammonia water 15.6
And 600 parts of distilled water were added to obtain a dispersion of a polyurethane solution. Next, the temperature of the aqueous dispersion was raised to 75 ° C., and 0.03 part of potassium persulfate was added to carry out an acrylic polymerization reaction for 4 hours.
Further, 0.01 part of potassium persulfate was added and the reaction was continued for 2 hours to obtain an aqueous urethane composite resin dispersion (A).

Production Example 2 A four-necked 2000 ml flask equipped with a reflux condenser, a dropping funnel, a gas inlet tube, a stirrer, and a thermometer was replaced with dry nitrogen, and the number average molecular weight was about 1,500 (hydroxyl value 56). 207.6 parts of polypropylene glycol, 27.3 parts of polyethylene glycol having a number average molecular weight of about 1,000 (hydroxyl value 111), and 22.7 parts of dimethylolpropionic acid were charged, and the temperature was raised to 60 ° C. Under stirring, 75.6 parts of tetramethylxylylene diisocyanate and 0.7 parts of dibutyltin dilaurate were added, the temperature was raised to 80 ° C., and the mixture was reacted for 7 hours to obtain a polyurethane having a number average molecular weight of 12,000.

To the polyurethane were added 10 parts of n-propyl alcohol, 30 parts of butyl acrylate, 30 parts of methyl methacrylate, and 6.7 parts of acrylic acid. 17.8 parts of aqueous ammonia and 600 parts of distilled water were added to obtain an aqueous dispersion of a polyurethane solution. Next, the temperature of the aqueous dispersion was raised to 75 ° C., and 1.1 parts of potassium persulfate was added to carry out an acrylic polymerization reaction.
Time went. Further, 0.3 part of potassium persulfate was added and 2
The reaction was continued for an hour to obtain an aqueous urethane composite resin dispersion (B).

Production Example 3 A four-necked 2000 ml flask equipped with a reflux condenser, a dropping funnel, a gas inlet tube, a stirrer, and a thermometer was replaced with dry nitrogen, and the number average molecular weight was about 2,000 (hydroxyl value 56). Of polytetramethylene glycol, 20.6 parts of polyethylene glycol having a number average molecular weight of about 2,000 (hydroxyl value 56), and 15.8 parts of dimethylolbutanoic acid, and the temperature was raised to 60 ° C. Under stirring, 38.0 parts of isophorone diisocyanate and 0.0 of dibutyltin dilaurate were added.
Five parts were added, the temperature was raised to 80 ° C., and the mixture was reacted for 12 hours to obtain a polyurethane having a number average molecular weight of 22,400.

Diurethane glycol monomethyl ether 30 parts, ethyl acrylate 70 parts, butyl acrylate 80 parts, methyl methacrylate 50
Parts of azobisisobutyronitrile were added. 38.9 parts of triethylamine and 600 parts of distilled water were added to obtain an aqueous dispersion of a polyurethane solution. Next, the aqueous dispersion is heated to 75 ° C.
And an acrylic polymerization reaction was performed for 6 hours to obtain an aqueous urethane composite resin dispersion (C).

Production Example 4 A four-necked 2000 ml flask equipped with a reflux condenser, a dropping funnel, a gas inlet tube, a stirrer, and a thermometer was replaced with dry nitrogen, and the number average molecular weight was about 2,000 (hydroxyl value 56). 138.6 parts of polytetramethylene glycol, 22.2 parts of polyethylene glycol having a number average molecular weight of about 1,000 (hydroxyl value: 111) and 14.3 parts of dimethylolbutanoic acid were charged, and the temperature was raised to 60 ° C. Under stirring, 44.9 parts of diphenylmethane diisocyanate and 0.05 part of dibutyltin dilaurate were added, the temperature was raised to 80 ° C., and the mixture was reacted for 10 hours to obtain a polyurethane having a number average molecular weight of 25,200.

Isopropyl alcohol 3 in polyurethane
0 parts, 70 parts of ethyl acrylate, 100 parts of butyl acrylate and 50 parts of methyl methacrylate were added. 30.2 parts of triethylamine and 600 parts of distilled water were added to obtain an aqueous dispersion of a polyurethane solution. Next, the aqueous dispersion was added to 75
C., and 3 parts of potassium persulfate was added to carry out an acrylic polymerization reaction for 4 hours. Further, add 1 part of potassium persulfate and add
The reaction was continued for an hour to obtain an aqueous urethane composite resin dispersion (D).

Production Example 5 A four-necked 2000 ml flask equipped with a reflux condenser, a dropping funnel, a gas inlet tube, a stirrer, and a thermometer was replaced with dry air, and the number average molecular weight was about 2,000 (hydroxyl value 56). 13.1 parts of polypropylene glycol, 1.2 parts of polyethylene glycol having a number average molecular weight of about 2,000 (hydroxyl value 56), and 1.7 parts of dimethylolbutanoic acid.
The temperature was raised to 0 ° C. Under stirring, 4 parts of isophorone diisocyanate and 0.01 part of dibutyltin dilaurate are added, and
Temperature, and allowed to react for 10 hours to obtain a number average molecular weight of 26,3.
00 polyurethane was obtained.

Isopropyl alcohol 3 in polyurethane
0 parts, 130 parts of butyl acrylate, 110 parts of methyl methacrylate, 100 parts of styrene, 40 parts of 2-ethylhexyl acrylate, and 7.6 parts of azobisisobutyronitrile were added. 54.4 parts of triethylamine and 600 parts of distilled water were added to obtain an aqueous dispersion of a polyurethane solution. Next, the temperature of the aqueous dispersion was raised to 75 ° C., and an acrylic polymerization reaction was performed for 6 hours to obtain an aqueous urethane composite resin dispersion (E).
I got

Production Example 6 A four-necked 2000 ml flask equipped with a reflux condenser, a dropping funnel, a gas inlet tube, a stirrer, and a thermometer was replaced with dry nitrogen, and the number average molecular weight was about 2,000 (hydroxyl value 56). 139.6 parts of polytetramethylene glycol, 20.6 parts of polyethylene glycol having a number average molecular weight of about 2,000 (hydroxyl value 56) and 18.4 parts of dimethylolbutanoic acid were charged, and the temperature was raised to 60 ° C. Under stirring, 42 parts of isophorone diisocyanate and 0.05 part of dibutyltin dilaurate were added, the temperature was raised to 80 ° C., and the mixture was reacted for 12 hours to obtain a polyurethane having a number average molecular weight of 33,500.

Isopropyl alcohol 3 in polyurethane
0 parts, 70 parts of ethyl acrylate, 100 parts of butyl acrylate and 50 parts of methyl methacrylate were added. 30.2 parts of triethylamine and 600 parts of distilled water were added to obtain an aqueous dispersion of a polyurethane solution. Next, the aqueous dispersion was added to 75
C., and 3 parts of potassium persulfate was added to carry out an acrylic polymerization reaction for 4 hours. Further, add 1 part of potassium persulfate and add
The reaction was continued for an hour to obtain an aqueous urethane composite resin dispersion (F).

Production Example 7 A four-necked 1000 ml flask equipped with a reflux condenser, a dropping funnel, a gas inlet tube, a stirrer, and a thermometer was replaced with dry nitrogen, and the number average molecular weight was about 1,500 (hydroxyl value: 76). 207.6 parts of polypropylene glycol, 27.3 parts of polyethylene glycol having a number average molecular weight of 1,000 (hydroxyl value: 111), and 22.7 parts of dimethylolpropionic acid, and the temperature was raised to 60 ° C. Under stirring, 75.6 parts of tetramethylxylene diisocyanate and 0.1 part of dibutyltin dilaurate were added, and the mixture was heated to 80 ° C. and reacted for 7 hours to obtain a polyurethane having a number average molecular weight of 12,500.

Butyl acrylate 30 in polyurethane
, 30 parts of methyl methacrylate and 6.8 parts of 2-ethylhexyl acrylate were added and stirred sufficiently. 17.1 parts of triethylamine and 600 parts of distilled water were added to obtain an aqueous dispersion of a polyurethane solution. Next, the temperature of the aqueous dispersion was raised to 75 ° C. while introducing, and 1 part of potassium persulfate was added to carry out an acrylic polymerization reaction for 4 hours. Further, 0.4 part of potassium persulfate was added and the reaction was continued for 2 hours to obtain an aqueous urethane composite resin dispersion (G). Production Example 8 A four-necked 2000 ml flask equipped with a reflux condenser, a dropping funnel, a gas inlet tube, a stirrer, and a thermometer was replaced with dry nitrogen, and methyl ethyl ketone (600 parts), number average molecular weight of about 2,000 (hydroxyl value 56 ), 32 parts of polyethylene glycol having a number average molecular weight of about 1,000 (hydroxyl value: 111) and 29.6 parts of dimethylolpropionic acid, and the temperature was raised to 60 ° C. Under stirring, 86.4 parts of isophorone diisocyanate,
0.1 part of dibutyltin dilaurate was added, the temperature was raised to 80 ° C., and the mixture was reacted for 4 hours to obtain a polyurethane having a number average molecular weight of 9,800.

The polyurethane solution was cooled to 30 ° C., 15 parts of ammonia water and 660 parts of distilled water were added, and the solvent was removed to obtain an aqueous urethane resin (H).

Using the aqueous urethane composite resins and the aqueous urethane resins obtained in Production Examples 1 to 8, samples shown in the following Examples were obtained and evaluated.

Example 1 A coating liquid was prepared by adding 10% of butyl cellosolve as a film forming aid to the aqueous urethane composite resin (A). Next, the coating liquid for the adjustment was applied to a thickness of 0.5 mm on a slate plate to which black lacquer was applied, and was formed into a film by a drier at 60 ° C to obtain a sample. The sample was irradiated for 500 hours with a Du-cycle type weather meter, and its gloss was measured. The gloss retention was calculated from the difference from the initial gloss. The aqueous resins used in Examples and Comparative Examples are described below. Example 2 Aqueous urethane composite resin (B) Example 3 Aqueous urethane composite resin (C) Example 4 Aqueous urethane composite resin (D) Example 5 Aqueous urethane composite resin (E) Comparative Example 1 Aqueous urethane composite resin (F) Comparative Example 2 Aqueous urethane composite resin (G) Comparative Example 3 Aqueous urethane resin (H) Example 6 50 parts of aqueous urethane composite resin (A), 20 parts of phthalocyanine blue pigment (Rionol Blue-KLH manufactured by Toyo Ink Mfg. Co., Ltd.), 0.1 parts of an antifoaming agent and 29.9 parts of water were stirred with a homomixer at 7,000 rpm for 20 minutes to obtain a pigment dispersion.

The pigment dispersion was dispersed in a Zahn cup # 4 using a mixed solvent of water / isopropyl alcohol = 1/1.
The coating time was adjusted to be seconds, and the coated OPP film ("Pyren P2161" manufactured by Toyobo Co., Ltd.) and the processed PET film ("Ester E5100" manufactured by Toyobo Co., Ltd.) were coated with a # 7 bar coater. Then, in a 60 ° C drying oven,
After drying for a minute, the samples were evaluated for film adhesion and color development. The aqueous resins used in Examples and Comparative Examples are described below. Example 7 Aqueous urethane composite resin (B) Example 8 Aqueous urethane composite resin (C) Example 9 Aqueous urethane composite resin (D) Example 10 Aqueous urethane composite resin (E) Comparative Example 4 Aqueous urethane composite resin (F) Comparative Example 5 Aqueous urethane composite resin (G) Comparative Example 6 Aqueous urethane resin (H)

The methods for evaluating the samples obtained in Examples 1 to 10 and Comparative Examples 1 to 6 are described below. The results are shown in Tables 1 and 2.

A) Evaluation of weather resistance The gloss retention of Examples 1 to 5 and Comparative Examples 1 to 3 was examined. ◎ Gloss retention is 80% or more ○ ６０ 60 to 80% △ 〃 40 to 60% × 〃 40% or less

B) Evaluation of Adhesion to OPP and PET Films The samples obtained in Examples 6 to 10 and Comparative Examples 4 to 6 were subjected to a tape peeling test to examine the adhesion. ◎ Does not peel at all. ○ Almost no peeling. △ Peel a little. X: It peels considerably.

C) Evaluation of color development The color development of the samples obtained in Examples 6 to 10 and Comparative Examples 4 to 6 was visually evaluated comprehensively from the density, gloss and transparency. ◎ Very good ○ Good △ Normal × Poor

[0054]

[Table 1]

[0055]

[Table 2]

[0056]

The present invention is an aqueous resin excellent in cost because the solvent removal step can be omitted. In the production process, the urethane resin and the unsaturated monomer can be directly chemically bonded to each other, so that a resin form different from that of the blend system can be obtained. Such a composite resin has advantages of urethane resin, such as weather resistance, alkali resistance, heat resistance, etc., which are disadvantages of urethane resin without impairing adhesion to a substrate, which is an advantage of urethane, abrasion resistance, solvent resistance, impact resistance. Since the physical properties can be improved, the present method has made it possible to provide an aqueous resin having extremely high practicality and an ink using the resin.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Tsukasa Otsuki 2-3-13-1 Kyobashi, Chuo-ku, Tokyo Toyo Ink Manufacturing Co., Ltd.

Claims (6)

[Claims] A) a first step of reacting a polyol with an organic polyisocyanate in the absence of a solvent to obtain a polyurethane (A) having a number average molecular weight of 30,000 or less; b) converting (A) an organic solvent having a hydroxyl group; And a second step of dispersing in water in the presence of an unsaturated monomer to obtain an aqueous dispersion (B) of a polyurethane solution. C) An aqueous resin obtained from the third step of radically polymerizing (B). 2. The aqueous resin according to claim 1, wherein the polyurethane has an ionizable dissociable group in the first step. 3. The aqueous resin according to claim 1, wherein in the first step, the polyurethane contains polyethylene glycol as an essential component. 4. The aqueous resin according to claim 1, wherein the organic solvent having a hydroxyl group in the second step contains isopropyl alcohol. 5. The aqueous resin according to claim 1, wherein the polyurethane content in the resin solid content of the aqueous resin obtained in the third step is 5 to 95% by weight. 6. An ink comprising the aqueous resin according to any one of claims 1 to 5.