JPS62270613A - Production of aqueous polyurethane dispersion of excellent bonding strength - Google Patents

Abstract

PURPOSE:To obtain the title aqueous dispersion excellent in storage stability, mechanical stability and usability in combination with other materials,by preparing a polyurethane substance by using an active hydrogen-containing compound, an organic polyisocyanate compound and two specified compounds. CONSTITUTION:A polyurethane substance is prepared by an isocyanate polyaddition reaction process by using an active hydrogen-containing compound (A) of MW 300-20,000, having at least two isocyanate groups and reactive active hydrogen atoms in the molecule, an organic polyisocyanate compound (B) and, optionally, a chain extender (C). In preparing an aqueous dispersion by adding water to the obtained polyurethane substance, 1-30pts.wt. compound (D) of formula I and 0.01-20pts.wt. compound (E) of formula II are reacted with 100pts.wt. solid matter of the polyurethane substance. In the formulas, R1 is a 1-20C alkyl, X and Y are each an oxyethylene unit, m and n are each the number of repeating units and R2 is a 1-3C alkyl.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for producing an aqueous dispersion of a high molecular weight polyurethane resin that does not contain an emulsifier and is useful for coatings, textiles, or adhesives, and further relates to For details, see Storage Stability 5. A water-based polyurethane that has excellent mechanical stability, compatibility with other resins, inorganic and organic pigments, and fillers, and excellent adhesion to various coated objects. The present invention relates to a method for producing a dispersion liquid.

[Conventional technology and its problems]

Various methods have been proposed for producing a high molecular weight aqueous polyurethane dispersion that does not contain an emulsifier, that is, is self-emulsifying. For example, Special Publication No. 43-9076, Special Publication No. 44
-27906, compounds having a basic tertiary amino group that can be neutralized with acid or quaternized in polyurethane materials, or carboxylic acid groups or sulfenic acid groups that have salt-forming ability. Methods are known in which the polyurethane material is water-solubilized or water-dispersed by containing a compound having the following properties and forming a salt before or during the addition of water to the polyurethane material. Polyurethane resins that are water-based only by the action of salt-forming groups do not contain emulsifiers, so the coating shows good water resistance, but the polyurethane resin itself is anionic or cationic, so The chemical resistance of the film, particularly both acid resistance and alkali resistance, has the disadvantage that one of them is significantly deteriorated. In addition, it is easily affected by various salts such as polyvalent metal salts, and therefore other resins and organic and inorganic pigments.

It has a major drawback in that it is extremely poor in compatibility with fillers, and its fruiting applications are extremely limited.

[Problem that the invention seeks to solve]

In order to improve the drawbacks of the salt-forming aqueous polyurethane dispersions described above, the present inventors have conducted extensive studies on polyurethane aqueous dispersions that do not contain substantially nonionic emulsifiers, and have found that An aqueous polyurethane dispersion with a stability of 9M and mechanical stability, excellent compatibility with other resins, inorganic and organic pigments, fillers, etc., and excellent adhesion to various coated objects. They discovered a manufacturing method and completed the present invention.

[Means for solving problems]

To summarize the present invention, the present invention comprises (A) an active hydrogen-containing compound having at least two isocyanate groups and reactive active hydrogen atoms in the molecule and having a molecular weight of 300 to 20,000, and CB) an organic polyisocyanate compound. , and optionally (C) Adding water to a polyurethane material prepared by an isocyanate polyaddition reaction method using a chain extender having an active hydrogen atom reactive with an isocyanate group, with or without desolvation, produces a polyurethane. In preparing the aqueous dispersion, when preparing the polyurethane material, CD) general formula 1 (0-(X)m-(Y)n-R
z [However, R1 in the formula represents an alkyl group of C-2o, X and Y may each be the same or different, and represent an essential oxyethylene unit and the oxyethylene unit,
A combination of either oxypropylene units or oxybutylene units, m and n indicate the number of repeating units. The total molecular weight of the oxyethylene units is 2,500 to 15,000, and the total weight of the oxyethylene units is 60% by weight or more of the total oxyalkylene. ], (A) 1 to 30 parts per 100 parts solid content of the polyurethane material obtained from (B) and (C), and (E) 100 parts solid content of the urethane material.
The present invention relates to a method for producing an aqueous polyurethane dispersion, which is characterized in that the reaction is carried out at a ratio of 0.01 to 20 parts per part.

The aqueous polyurethane dispersion of the present invention prepared by the method described above is an aqueous dispersion of a high molecular weight polyurethane resin that is substantially nonionic and does not contain an emulsifier. The resulting coating has excellent water resistance and chemical resistance, and is not affected by polyvalent metal salts, etc., so it is extremely compatible with other resins, organic and inorganic pigments, fillers, etc. It has extremely excellent adhesion to the coated material.

Hereinafter, the configuration of the present invention will be explained in detail.

(A) The active hydrogen-containing compound having at least two isocyanate groups and reactive active hydrogen atoms in the molecule and having a molecular weight of 300 to 20,000 is generally linear, and used in the method of the present invention. Molecular weight is 300-200
00, preferably 500 to 4000.

Such compounds include those containing terminal hydroxyl, carboxyl, amino or mercapto groups, such as polyesters and polyacetals.

Mention may be made of polyhydroxy compounds such as polyethers, polythioethers, polyamides and polyesteramides.

- Polyethers include, for example, polymerization products and copolymerization or graft polymerization products of ethylene oxide, propylene oxide, tetrahydrofuran, and butylene oxide, as well as these and polyhydric alcohols, or mixtures thereof and polyhydric alcohols, amines, and polyamines. and polyethers obtained by polymerization with amino alcohols.

Examples of the O polyacetal include compounds that can be produced from hexanediol and formaldehyde.

O-polythioethers which may be mentioned in particular are polymerization products of thiodiglycol and from mixtures of thiodiglycol with other glycols or polyhydroxy compounds.

O polyesters, polyesteramides and polyamides are obtained from polyvalent saturated and unsaturated carboxylic acids and polyvalent saturated and unsaturated alcohols, amino alcohols, diamines, polyamines and mixtures thereof, Mention may be made of those in which linear condensates predominate, such as polyterephthalates or polycarbonates.

Other polyhydroxy compounds containing urethane groups or urea groups, as well as natural polyols, including those optionally modified, such as castor oil and carbohydrates, can also be used.

It goes without saying that in the process of the invention, mixtures of various polyhydroxy compounds can be added in order to change the hydrophilicity and hydrophobicity and physical properties of the final product.

Used in the method of the invention. (B) The organic polyisocyanate compound is, for example.

(2) 5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 4,4'-dibenzyl diisocyanate.

isomers of toluylene diisocyanate, 1,4-phenylene diisocyanate (1,4-phenylene diisocyanate), optionally mixtures thereof, chlorinated and/or
or all aromatic and aliphatic diisocyanates such as brominated diisocyanates, phosphorous-containing diisocyanates, butane-1,4-diisocyanate, hexane-1,6-diisocyanate, dicyclohexylmethane diisocyanate, and cyclohexane-1,4-diisocyanate. suitable.

Particularly advantageous are, for example, dimers of toluylene diisocyanate 1 to 1, or phenol, tertiary butanol,
There are partially blocked polyisocyanates which themselves have the ability to form crosslinked polyurethanes, such as polyisocyanates partially reacted with phthalimide or cabrolactam.

(C) The chain extender having an active hydrogen atom reactive with an isocyanate group used in the method of the present invention includes: 1. Ethylene glycol or a condensate of ethylene glycol, such as butanediol, propanediol-1
, 2, propanediol-1,3°neopentyl glycol, hexanediol.

Glycols such as bis-hydroxymethyl-cyclohexane and dioxyethyldian.

2. Ethanolamine, propatoolamine, butanolamine, N-methylgetanolamine, N-butylgetanolamine, N,N-bis-thiaminopropyl-N-methylamine, N-oleylgetanolamine, N- cyclohexyldiisopropanolamine,
N,N-dioxyethyl-p-toluidine, N,N
-dioxypropylnaphthyramine, polyethoxylated N-butylgetanolamine, polypropylated N-methylgetanolamine (molecular weight 300-400
0), polyester with tertiary amino group, dimethyl-
Mono- or bis-alkoxylated aliphatic, cycloaliphatic, aromatic and heterocyclic amino alcohols such as bis-oxyethyl-hydrazine.

3. Unsaturated glycols such as butynediol and butynediol.

4. Ethylenediamine, hexamethylenediamine, 1
, 4-cyclohexylene diamine, pentidine, diaminodiphenylmethane, aliphatic, cycloaliphatic and aromatic diamines such as isomers of phenyl diamine.

5. Other examples include water, hydrazine, ammonia, and carbohydrazide.

It is then used in the method of the invention. (D) General formula〇〇-
The compound represented by (X)m (Y)n' will be explained.

In the general formula, R□ is C1-21. represents an alkyl group of where m and n indicate the number of repeating units.

In the present invention, among the compounds represented by the above general formula, the total molecular weight of oxyethylene units is 1,500 to 1,500.
15,000 and the total weight of the oxyethylene units is 60% by weight or more of the total oxyalkylene.

As a typical compound represented by the above general formula, R1 is C
It is a compound obtained by adding ethylene oxide alone, or ethylene oxide, propylene oxide and/or butylene oxide to a monoalcohol having 1 to 28 carbon atoms, preferably 4 to 4 carbon atoms. At that time, the total molecular weight of the polyoxyethylene moiety, that is, the oxyethylene unit, is 2500 to 15000, preferably 3000 to
10,000, more preferably 3,000 to 8,000, and a polyoxyethylene portion,
In other words, only ethylene oxide, or ethylene oxide and propylene oxide and/or ethylene oxide, propylene oxide and/or Alternatively, it is important to prepare by block polymerizing or random polymerizing butylene oxide. The compound (D) thus prepared is a polyoxyalkylene compound in which one end group is a C-2° alkyl group and the other end group is a hydroxyl group. If the sum of the molecular weights of oxyethylene units is less than 2,500, the aqueous dispersion of the resulting polyurethane material will be insufficient, whereas if it exceeds 15,000, the number of hydroxyl groups per unit molecular weight in the hydrophilic monohydroxy compound will be insufficient. is extremely small, which again significantly reduces the effect of aqueous dispersion of the polyurethane material, so either case is unfavorable. Furthermore, if the proportion of polyoxyethylene moieties (oxyethylene units) in the polyoxyalkylene moieties (in all oxyalkylene units) in the hydrophilic monohydroxy compound that is the compound (D) is less than 60% by weight, This is not preferred because the degree of hydrophilicity of the hydrophilic monohydroxy compound decreases, that is, the aqueous dispersion ability of the resulting polyurethane material decreases.

In the present invention, the above (D) general formula 〇〇-(X), -(
Y) The amount of the hydrophilic monohydroxy compound represented by n-RL is 1 to 30 parts based on 100 parts of the solid content of the polyurethane obtained from (A), (B) and (C). (D) The amount of hydrophilic monohydroxy compound is (A
).

If the amount is less than 1 part based on 100 parts of the solid content of the polyurethane material obtained from (B) and (C), the resulting polyurethane material will have poor water dispersibility and may not be able to be water-dispersed, or even if it can be water-dispersed, it will be extremely poor. Unfavorable for stability. Furthermore, when the amount of (D) the hydrophilic monohydroxy compound is more than 30 parts per 100 parts of the polyurethane material, no significant improvement in water dispersibility is observed even if the amount is increased further, and it is uneconomical. Not only that, but also the water resistance and chemical resistance of the resulting film from the aqueous polyurethane dispersion are significantly reduced, which is not preferable. In the present invention, the preferred amount of the hydrophilic monohydroxy compound (D) used is within the range of 2 to 20 parts per 100 parts of solid content of the polyurethane material obtained from (A), (B) and (C).

Tyrolpropionic acid, 2,2-dimethylolbutyric acid.

and 2,2-dimethylolvaleric acid.

ll! ! The amount of (R2=C-3 represents an alkyl group) used is (
The polyurethane material obtained from A), (B) and (C) shows the alkyl group. ), when the amount used is less than 0.01 part, almost no effect of improving the adhesion of the resulting polyurethane material to various coated objects will be observed. 20 again
%, even if the amount used is increased further, it is not only uneconomical because no significant improvement in adhesion is observed, but also reduces the water resistance etc. of the resulting polyurethane material. Undesirable.

Particularly preferred usage amounts of (group) are (A), (B) and (
The amount is within the range of 0.05 to 10 parts based on 100 parts of solid content of the polyurethane material obtained from C). In the present invention, it also represents an alkyl group. ) is usually used without being neutralized with an alkali substance from the viewpoint of water resistance of the resulting polyurethane material, but of course some or all of the carboxyl groups may be neutralized with an alkali substance. do not have. In that case, volatile alkaline substances such as ammonia, trimethylamine, triethylamine, morpholine, etc. are preferably used.

In the present invention, in order to produce a polyurethane material from the various components described above, a method known per se is employed in the presence or absence of a solvent, and in this case, the compound (D) is added at any point during the reaction. added.

Generally, the above-mentioned (
A) component high molecular weight polyhydroxy compound and (D
) component (general formula) 10-(X)□-(Y).

In the mixture with a hydrophilic monohydroxy compound called -R,
The alkyl group of the organic polyisocyanate compound of component (B) is shown. ) alone, or (E) in the present invention, since component (D) is monofunctional, one reaction system includes a trifunctional or polyfunctional component such as glycerin or trimethylolpropane, water, and a diamine.

The use of polyisocyanate compounds and the like is generally preferred since a polyurethane material having a high molecular weight can be obtained when these compounds are used in combination.

Further, in the present invention, it is also possible to add an organic solvent for the purpose of controlling the reaction system or reducing the viscosity during the preparation of the polyurethane material. When using organic solvents,
Aromatic hydrocarbons such as toluene, xylene, and acetone are preferred from the viewpoints of cost, ease of reaction control, and solubility of polyurethane materials.

Ketones such as methyl ethyl ketone and methyl isobutyl ketone, and acetate esters such as ethyl acetate and butyl acetate are preferably used.

As described above, components (A), (B), and (C), together with (D) the hydrophilic monohydroxy compound and (E) the resin substance, are first water-dispersed by adding water. As a method for water dispersion, water may be gradually added dropwise to the polyurethane material to which a hydrophilic monohydroxy compound is added while stirring to effect phase inversion emulsification.

Alternatively, a polyurethane material to which a hydrophilic monohydroxy compound has been added may be gradually dropped into well-stirred water. Usually, phase inversion emulsification is preferred, in which water is gradually added dropwise to a polyurethane material to which a hydrophilic monohydroxy compound has been added while stirring at a high speed at a temperature of 60° C. or lower. Of course, in water dispersion, a method of applying mechanical shearing force using various homomixers or homogenizers can be used in combination, and this is a preferred method for obtaining a stable aqueous polyurethane dispersion. Furthermore, a method in which ultrasonic waves are applied during aqueous dispersion is also one of the preferred methods.

In the present invention, when dispersing the polyurethane material prepared as described above in water, an organic solvent that is easily miscible with water can be used in combination, and this method is more preferable for obtaining a stable aqueous polyurethane dispersion. It's a method. Such solvents having good miscibility with water include cz'4 lower alcohols; ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, propylene glycol monobutyl ether, etc. Various ethers; ketones such as acetone and methyl ethyl ketone may be mentioned.
I The aqueous polyurethane dispersion prepared as described above can be used as it is, but it is usually azeotropically removed along with water by heating and depressurization in order to remove the various organic solvents used together. is common.

The thus obtained aqueous polyurethane dispersion of the present invention is an aqueous dispersion of a high molecular weight polyurethane resin that does not substantially contain a nonionic emulsifier. This aqueous dispersion has storage stability, mechanical stability, and also other resins, inorganic and organic pigments.

It has excellent usability with fillers, and since it contains carboxyl groups in the polymer, it has excellent adhesion to various coated objects. Therefore, the aqueous polyurethane dispersion of the present invention can be used in many applications to which conventional salt-type aqueous polyurethane dispersions cannot be applied.

Textiles 2 Paper, leather, wood, metal coating, impregnation of fibers and textiles (e.g. texture treatment, antistatic treatment, anti-wrinkle finishing, etc.) 2 Binders and adhesives for fur.

Adhesives, backing agents, hydrophobizing agents.

It can be used as an elasticizing component or an anti-fracture component in the construction industry (e.g. as an additive in concrete mixtures and asphalt mixtures), as a vehicle for various paints, for exterior paints, for household aerosol paints, etc. can. Also coal powder.

It can be used as a binder for wood powder, glass fiber, asbestos paper, plastic or rubber scraps, ceramic materials, etc., and also as an alkali-removable protective coating. Furthermore, the aqueous polyurethane dispersion of the present invention can be used as a softening agent in the production of elastic films, foils, and yarns, as an auxiliary agent in the textile printing and yarn industry, as an additive for synthetic resin dispersions, as a sizing agent, and as a sizing agent for leather. It can be used in a wide range of applications, including as a finishing agent.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples as long as the technical idea of the present invention is not departed from.

<Example 1> First, 967% of adipic acid-1,6 hexanediol-neopentyl glycol-polyester (08 value 58) was placed in a 4-tubular flask equipped with a thermometer, a stirrer, and a reflux condenser.
Polyoxyethylene methyl ether glycol (molecular formula) with a molecular weight of 4060 and 10-(CHz CHz
Add 35 parts of O) n CH3) and heat under reduced pressure at 120~
Dehydration is carried out at 130°C, then 163 parts of 1.6 hexamethylene diisocyanate is added, and reaction is carried out at 120°C for 2 hours while stirring the melt. Then, after cooling to 60°C and adding 810 parts of methyl ethyl ketone, 1.
Add 36 parts of 4-butanediol, 13:4 parts of dimethylolpropionic acid, and 0.4 part of trimethylolpropane, and stir at 80°C for 5 hours to obtain a viscous transparent solution. After diluting the obtained solution by adding 121 parts of isopropyl alcohol, 1325 parts of water was added dropwise over 2 hours while keeping the temperature at 50°C. Then, methyl ethyl ketone and isopropyl alcohol were distilled off under reduced pressure at 50°C to obtain a milky white aqueous polyurethane dispersion having a non-volatile content of 48.6 parts and a viscosity of 300 cps.

This product forms a transparent, glossy, tough, elastic coating on a metal plate, has excellent adhesion, and is water resistant.

Both acid resistance and alkali resistance were extremely excellent. Further, 20 parts of aluminum hydroxide powder was added as a filler to 100 parts of the obtained aqueous polyurethane dispersion, and the mixture was mixed and stirred using a homomixer, but the mixture was extremely stable.

<Example 2> 2150 parts of polyoxypropylene glycol having a molecular weight of 430 was added to the same apparatus as in Example 1, and the mixture was heated to 120 parts under reduced pressure.
Dehydration is carried out at ~130°C, the mixture is cooled to 60°C, and 3062 parts of methyl ethyl ketone are added, followed by 1715 parts of 4,4' diphenylmethyl diisocyanate. 2 at 80℃
time and then general formula HO-(X), -(y)n
460 parts of ethylene oxide-propylene oxide random polymer composed of -C, H, (molecular weight of polyoxyethylene moiety: 8000, polyoxyethylene/polyoxyalkylene = 80%) and 268 parts of dimethylolpropionic acid were added at the same time to 80°C. After stirring for 3 hours, a viscous transparent solution is obtained. 50% of the resulting solution
While maintaining the temperature at °C, 5468 parts of water was added dropwise over about 10 minutes, followed by water dispersion through a colloid mill.

Next, methyl ethyl ketone was distilled off under reduced pressure while maintaining the same temperature, resulting in a non-volatile content of 47.8 parts and a viscosity of 260 cps.
A milky white aqueous polyurethane dispersion was obtained. This product forms a transparent, glossy, tough, elastic coating on a baked-on board made of oil-free alkyd-melamine resin, has excellent adhesion, and has extremely high water resistance and chemical resistance. was.

Also, 100 parts of the obtained polyurethane aqueous dispersion.

30 parts of aluminum hydroxide powder was added as a filler and mixed and stirred using a homomixer, but the mixture was extremely stable.

For comparison, when aluminum hydroxide powder was added to a cationic polyurethane aqueous dispersion used as a commercially available N-methyljetanolamine chain extender, lump-like aggregates were immediately generated.

<Example 3> In a device similar to Example 1, a polyoxypolyoxyethylene-polyoxypropylene block polymer with a molecular weight of 1000 (molecular weight of the polyoxyethylene portion 6500, polyoxyethylene/polyoxyalkylene = 75%) 10
0 parts was added, dehydrated at 120°C under reduced pressure, and then 1 part was added.
, 1.0 parts of 1-trimethylolpropane and 0.24 parts of dimethylolbutyric acid were added, followed by 119 parts of inbon diisocyanate, and the reaction was carried out at 120°C for 4 hours to obtain an extremely viscous and transparent solution. . After adding 385 parts of isopropyl alcohol and 150 parts of butyl cellosolve to the obtained solution, 1210 parts of water was added dropwise over 2 hours at 50°C, and then the isopropyl alcohol was distilled off under reduced pressure at the same temperature. . This gives a milky white aqueous polyurethane dispersion with a non-volatile content of 37.1 and a viscosity of 60 cps.

This product formed a transparent, glossy, elastic coating with excellent adhesion on an acrylic-urethane coated plate, and the coating had extremely excellent water resistance and chemical resistance. Furthermore, the obtained aqueous polyurethane dispersion exhibited excellent compatibility with both anionic acrylic emulsions and cationic acrylic emulsions.

<Example 4> Add 2,500 adipic acid-1,6 hexanediol polyester (OH value 112) to the same apparatus as Example 1,
Dehydration was performed at 120 to 130°C under reduced pressure, then cooled to 80°C, 1458 parts of tolylene diisocyanate (2,4/2.6-isomer ratio = 80/20) was added, and 3 parts were added at the same temperature.
Perform a time reaction. Then, it was cooled to 60°C and the general formula HO-(
x)+m-mn-c, t+, 200 parts of ethylene oxide-butylene oxide random polymer (molecular weight of polyoxyethylene portion: 4500, polyoxyethylene/polyoxyalkylene = 80%), 134 parts of dimethylolpropionic acid. After adding 2,930 parts of acetone and 3 hours at the same temperature, 100 PPIll of dibutyltin dilaurate was added and the reaction was further carried out for 2 hours.
Add 119 parts of N-methyljetanolamine. If the reaction is continued for 2 hours at the same temperature, a viscous and transparent solution is obtained. While maintaining the obtained solution at 50°C, 5260 parts of water was added dropwise over about 3 hours, and then the pressure was reduced at the same temperature to distill off acetone. In this way, the non-volatile content is 48.
A milky white aqueous polyurethane dispersion with a 6% viscosity of 245 cps was obtained.

This product has excellent adhesion to galvanized steel sheets, forms a transparent and glossy elastic coating, and has excellent water resistance and
Both had excellent chemical resistance. Furthermore, 20 parts of aluminum hydroxide powder was added as a filler to 100 parts of the obtained aqueous polyurethane dispersion, and the mixture was mixed and stirred using a homomixer, but the mixture was extremely stable.

For comparison, when 20 parts of aluminum hydroxide powder was added to a commercially available aqueous anionic polyurethane dispersion using dimethylolpropionic acid as a chain extender, lumpy aggregates were immediately formed.

<Comparative Example 1> In Example 1, polyoxyethylene monomethyl ether glycol (molecular formula HO-(CH,CH20)@-C
A viscous transparent solution was synthesized in exactly the same manner except that H,) having a molecular weight of 2060 was used. After diluting the obtained solution by adding 121 parts of isopropyl alcohol, 50 parts of
1325 parts of water was added dropwise while keeping the temperature at 0.degree. C., but a white lump formed and could not be water-dispersed.

<Comparative Example 2> In Example 1, the general formula HO-(X)t-(Y)n
-C4) A viscous transparent solution was prepared in exactly the same manner except that an ethylene oxide-propylene oxide random polymer (molecular weight of the polyoxyethylene moiety: 3000, polyoxyethylene/polyoxyalkylene = 50%) represented by 1° was used. Synthesized. After diluting the resulting solution by adding 121 parts of isopropyl alcohol, 1,325 parts of water was added dropwise while keeping the temperature at 50°C, but a white lump formed and could not be water-dispersed.

Comparative Example 3> In Example 1, (E) dimethylolpropionic acid
An aqueous polyurethane dispersion was prepared in exactly the same manner except that 9 parts of 1,4-butanediol was added instead of 13.4 parts. The resulting aqueous polyurethane dispersion was distilled off under reduced pressure to remove methyl ethyl ketone and isopropyl alcohol, resulting in a nonvolatile content of 48.2% and a viscosity of 270 cps.
It was made into something. This product forms a transparent, glossy and tough elastic coating, and has excellent water and chemical resistance.
The coating film formed on the galvanized steel plate had poor adhesion and was observed to easily peel off from the steel plate.

<Comparative Example 4> 2150 parts of polyoxypropylene glycol having a molecular weight of 430 was added to the same apparatus as in Example 1, and the mixture was heated under reduced pressure to 120 to 1
Dehydration is carried out at 30°C, the mixture is cooled to 60°C, 2755 parts of methyl ethyl ketone are added, and then 1715 parts of 4,4'-diphenylmethane diisocyanate are added.

Hold at 80℃ for 2 hours, dimethylolpropionic acid
After adding 268 parts and stirring at 80°C for 3 hours, a viscous transparent solution is obtained. Water containing 101 parts of triethylamine 9644 while maintaining the resulting solution at 50°C
1 part was added dropwise over a period of 3 hours, and then methyl ethyl ketone was distilled off under reduced pressure while maintaining the same temperature, resulting in a non-volatile content of 30.3. A milky white aqueous anionic polyurethane dispersion with a viscosity of 860 cps was obtained. Although this product forms a coating film with relatively good water and chemical resistance, it has poor compatibility with other resins, inorganic and organic pigments, and fillers, and aluminum hydroxide powder is used as a filler instead of polyurethane. When 20 parts were added to 100 parts of the aqueous dispersion, lump-like aggregates were immediately formed.

〔Effect of the invention〕

As detailed above, the present invention improves storage stability.

mechanical stability, and also other resins, inorganic and organic pigments,
Provided is an aqueous polyurethane dispersion that is highly compatible with fillers and has excellent adhesion to various coated objects. Therefore, the aqueous polyurethane dispersion of the present invention can be used in a wide variety of applications to which conventional salt-type aqueous polyurethane dispersions cannot be applied.

Claims (1)

[Claims] 1. (A) has at least two active hydrogen atoms reactive with isocyanate groups in the molecule, and has a molecular weight of 300 to 2
0,000 active hydrogen-containing compound, (B) an organic polyisocyanate compound, and optionally (C) a chain extender having an active hydrogen atom that is reactive with isocyanate groups. (D) General formula HO-(X)_
m-(Y)_n-R_1 [However, R_1 in the formula is C_1
_~_2_0, X and Y may each be the same or different, and represent a combination of an essential oxyethylene unit and any one of the oxyethylene unit, oxypropylene unit, or oxybutylene unit. ,
m and n indicate the number of repeating units. The total molecular weight of the oxyethylene units is 2,500 to 15,000, and the total weight of the oxyethylene units is 60% by weight or more of the total oxyalkylene. ] 1 to 30 parts per 100 parts solid content of the polyurethane material obtained from (A), (B) and (C), and (E)
▲There are mathematical formulas, chemical formulas, tables, etc.▼(R_2 is C_1~
Indicates the alkyl group of C_3. ) to (A), (B) and (
A method for producing an aqueous polyurethane dispersion having excellent adhesive strength, characterized in that the reaction is carried out in a proportion of 0.01 to 20 parts per 100 parts of the solid content of the polyurethane material obtained from step C). 2. The method for producing an aqueous polyurethane dispersion according to claim 1, which comprises coexisting an organic solvent that is easily miscible with water when adding water to the polyurethane material to form an aqueous dispersion. 3. The method for producing an aqueous polyurethane dispersion according to claim 1 or 2, which comprises applying mechanical shearing force when adding water to the polyurethane material to form an aqueous dispersion. 4. The method for producing an aqueous polyurethane dispersion according to claim 1 or 2, characterized in that when water is added to the polyurethane substance to form an aqueous dispersion, ultrasonic waves are applied. 5, ▲There are mathematical formulas, chemical formulas, tables, etc.▼(R_2=C_
Indicates an alkyl group of 1_ to _3. Claim 1, wherein the compound represented by ) is dimethylolpropionic acid.
A method for producing an aqueous polyurethane dispersion as described in . 6, ▲There are mathematical formulas, chemical formulas, tables, etc.▼(R_2=C_
Indicates an alkyl group of 1_ to _3. ), when water is added to a polyurethane material containing carboxylic acid groups for aqueous dispersion, some or all of the carboxylic acid groups are neutralized with an alkaline substance. A method for producing the aqueous polyurethane dispersion described.