JP7151069B2 - Aqueous polyurethane resin dispersion, its production method and its use - Google Patents

Description

TECHNICAL FIELD The present invention relates to an aqueous polyurethane resin dispersion in which a polyurethane resin is dispersed in an aqueous medium. The present invention also provides a method for producing the aqueous polyurethane resin dispersion, a coating composition, a coating composition, an ink composition containing the aqueous polyurethane resin dispersion, and a composition containing the polyurethane resin dispersion. It relates to a polyurethane resin film obtained by drying.

Aqueous polyurethane resin dispersions have excellent adhesion to substrates, wear resistance, impact resistance, solvent resistance, etc., and are used as paints, inks, adhesives, and various coating agents for paper, plastics, films, Widely used for metals, rubbers, elastomers, textiles, etc.

Among various water-based polyurethane resin dispersions, coating films obtained by applying water-based polyurethane resin dispersions made from polycarbonate polyols in particular have excellent light resistance, weather resistance, heat resistance, hydrolysis resistance, and oil resistance. It is known.

For example, a coating film obtained by applying an aqueous polyurethane resin dispersion made from a polycarbonate polyol having 1,6-hexanediol as a polyol monomer and a polyether polyol as raw materials has flexibility, hydrolysis resistance, and chemical resistance. It is known to be excellent in flexibility and toughness (that is, flexibility and mechanical durability) (see Patent Documents 1 and 2).

Moreover, it is known that a coating film obtained by applying a water-based polyurethane resin made from polyether polyol is excellent in flexibility, hydrolysis resistance, and moist heat resistance (Patent Document 3).

Furthermore, it is known that by using a polyether-polycarbonate polyol composition, a thermoplastic polyurethane resin for optical members, which is most suitable for optical moldings, optical sheets, optical films, and light-emitting element sealing materials, can be obtained. (Patent Document 4).

In addition, a method of using an aqueous polyurethane resin dispersion has been disclosed in order to obtain a textile ink which is excellent in fastness to rubbing, resistance to washing, resistance to dry cleaning, and stretchback property of pigment prints (Patent Document 5). .

JP-A-2005-8888 Japanese Patent No. 4528132 WO2015-194672 JP 2015-17183 A JP-A-2-91280

Adhesion Handbook 4th Edition Editor: The Adhesion Society of Japan

However, tactile sensation (softness) and tack-free property are contradictory subjects (Non-Patent Document 1), and an aqueous polyurethane resin dispersion that gives a coating film excellent in both of these properties has not been proposed. Furthermore, no water-based polyurethane resin dispersion has been proposed that simultaneously satisfies substrate conformability and stretch-back properties (low hysteresis loss). In addition, no report has been made on the application of the polyether-polycarbonate polyol composition described in Patent Document 4 to an aqueous polyurethane resin dispersion or the unique properties of the aqueous polyurethane resin dispersion.

Accordingly, an object of the present invention is to obtain a water-based polyurethane resin dispersion that gives a coating film having good touch feeling, tack-free properties, substrate conformability, and stretch-back properties (low hysteresis loss).

（ｍ、ｎは、１より大きい数を示す。） The present invention has been made to solve the above problems, and has (a) a polyol-derived structure, (b) a polyisocyanate-derived structure, and (c) an acidic group-containing polyol-derived structure. In the aqueous polyurethane resin dispersion,
The above-mentioned (a) structure derived from a polyol has (a1) a structure derived from a polycarbonate polyol having a repeating unit represented by the following formula (1). I came up with the invention.

(m and n represent numbers greater than 1.)

INDUSTRIAL APPLICABILITY According to the present invention, there is provided an aqueous polyurethane resin dispersion that gives a coating film having good touch feeling, tack-free properties, substrate conformability, and stretch-back properties (low hysteresis loss).

Hereinafter, embodiments of the present invention will be described in detail. It should be noted that the polymer compound of the present invention can be obtained as a product having a large number of structures by reacting a plurality of types of raw material compounds. Therefore, a polymer compound is not uniquely represented by its structure even if many structures contained therein can be described by a general formula. In addition, it is difficult to directly measure its physical properties by instrumental analysis or the like to specify it or distinguish it from existing compounds. Therefore, in the present invention, the polymer compound including the "aqueous polyurethane resin dispersion" may be specified by the production method, if necessary.

（ｍ、ｎは、１より大きい数を示す。） The present invention provides an aqueous polyurethane resin dispersion having (a) a polyol-derived structure, (b) a polyisocyanate-derived structure, and (c) an acidic group-containing polyol-derived structure,
The present invention relates to an aqueous polyurethane resin dispersion in which the (a) polyol-derived structure has (a1) a polycarbonate polyol-derived structure having a repeating unit represented by the following formula (1).

(m and n represent numbers greater than 1.)

（ｍ、ｎは、１より大きい数を示す。） <<(a) Polyol>>
In the present invention, the polyol-derived structure in the aqueous polyurethane resin dispersion indicates a partial structure of the polyol molecular structure other than the groups contributing to the polyurethane formation reaction.
In the present invention, (a) the polyol-derived structure has (a1) a polycarbonate polyol-derived structure having a repeating unit represented by the following formula (1).
Furthermore, (a) the polyol-derived structure excludes (a1) a polycarbonate polyol-derived structure having a repeating unit represented by the following formula (1) and (c) an acidic group-containing polyol-derived structure (a2) other A structure derived from a polyol may also be included.

(m and n represent numbers greater than 1.)

<<(a1) Polycarbonate polyol having a repeating unit represented by formula (1)>>
(a1) The polycarbonate polyol having a structure derived from a polycarbonate polyol having a repeating unit represented by the formula (1) may have a repeating unit represented by the formula (1) and a terminal hydroxyl group. The type is not particularly limited, and may have multiple types of structures.
(a1) The polycarbonate polyol having a repeating unit represented by the formula (1) is sometimes described as (a1) or (a1) carbonate polyol.

(repeating unit)
The structure of the repeating units in the polycarbonate polyol is a structure derived from the monomers constituting the polycarbonate polyol, and the total number of repeating units (corresponding to m in the above formula (1)) corresponds to the number of monomers constituting the polycarbonate polyol. do.
Therefore, by measuring the number of monomers contained in the polycarbonate polyol, the total number of repeating units (total number of moles of all monomers) and the number of each repeating unit (number of moles of each monomer) can be calculated.

As a method for measuring the monomer, for example, a polycarbonate polyol, ethanol and a base are mixed, the mixed solution is heated to cause alcoholysis to obtain a monomer, and then the obtained monomer is analyzed by gas chromatography. There is a method. As another method for measuring monomers, there is also a method of directly measuring polycarbonate polyol by proton nuclear magnetic resonance spectroscopy ( ¹ H-NMR).

Examples of the monomer having a structure derived from the monomer constituting the repeating unit of formula (1) include, but are not limited to, polytetramethylene glycol.

(Repeating unit of formula (1))
Specifically, the repeating unit represented by formula (1) is, for example, a repeating unit formed by the reaction of polytetramethylene glycol and carbonate ester.
The ratio of the repeating unit represented by formula (1) to all repeating units in the polycarbonate polyol is preferably 10 to 100 mol%, more preferably 50 to 99.9 mol%, and particularly preferably 80 to 99.8 mol%. is.
Within this range, the polyurethane derived from the polycarbonate polyol exhibits high flexibility (tactile feel) and good tack-free properties.

(Other repeating units)
The (a1) polycarbonate polyol of the present invention contains repeating units other than the repeating units of formula (1) (hereinafter sometimes referred to as "other repeating units") as long as the content ratio of the repeating units is satisfied. may be included. Examples of monomers constituting other repeating units (other monomers) include 2-methyl-1,3-propanediol and 2-methyl-1,3-pentanediol (when a propylene group is the main chain, 1- (also referred to as ethyl-2-methylpropanediol), 1,4-butanediol, 1,2-ethanediol, 1,3-propanediol, 3-oxa-1,5-pentanediol (diethylene glycol), 2, 2-dimethyl-1,3-propanediol, 1,5-pentanediol, 2-methyl-1,5-pentanediol, 1,5-hexanediol, 1,6-hexanediol, 1,4-cyclohexanediol, diols having 2 to 12 carbon atoms such as 3-methyl-1,5-pentanediol, 1,8-octanediol and 1,4-cyclohexanedimethanol; carbon atoms such as γ-butyrolactone, valerolactone and caprolactone Lactones of 5 to 12; hydroxycarboxylic acids of 5 to 12 carbon atoms, such as hydroxybutanoic acid, hydroxypentanoic acid, hydroxyhexanoic acid; and hydroxybutanoic acid esters.
Other repeating units can be formed by the method shown for the repeating unit of formula (1), depending on the type of monomer.
The ratio of other repeating units in the polycarbonate polyol is the ratio obtained by subtracting the total ratio of the repeating units of formula (1) from the total repeating units, and is preferably 0.1 to 50 mol%.
Within this range, the functions of the (a1) polycarbonate polyol of the present invention are not impaired.

(Number average molecular weight of polycarbonate polyol)
The number average molecular weight of the (a1) polycarbonate polyol of the present invention can be appropriately adjusted according to the purpose, but is preferably 100 to 5,000, more preferably 200 to 4,000, and more preferably 300 to 3,000.
Within this range, handling of the polycarbonate polyol is facilitated, and the low-temperature properties of the polyurethane derived from the polycarbonate polyol are improved.

(Production of Polycarbonate Polyol)
The method for producing the (a1) polycarbonate polyol of the present invention is not particularly limited, but for example, polytetramethylene glycol (constituent of formula (1)), other monomers (other constituents of repeating units), carbonate ester and a catalyst are mixed and reacted while distilling off low-boiling components (for example, by-product alcohol).
In the reaction of the present invention, once a prepolymer of polycarbonate polyol (lower molecular weight than the target polycarbonate polyol) is obtained, the reaction is divided into multiple times, such as reacting the prepolymer to further increase the molecular weight. can also be done.
The other monomers may be contained in advance in polytetramethylene glycol as a main raw material.

When polytetramethylene glycol is used as a raw material, its number average molecular weight is preferably 50-3000, more preferably 100-2000, and more preferably 150-1000.
In addition, (a1) polycarbonate polyol may use multiple types together.

(Carbonate ester)
The carbonate used in the reaction of the present invention includes, for example, dialkyl carbonates such as dimethyl carbonate, diethyl carbonate and methylethyl carbonate; diaryl carbonates such as diphenyl carbonate; ethylene carbonate, propylene carbonate (4-methyl-1,3-dioxolane- 2-one, trimethylene carbonate), butylene carbonate (4-ethyl-1,3-dioxolan-2-one, tetramethylene carbonate), cyclic carbonates such as 5-methyl-1,3-dioxan-2-one. dimethyl carbonate, diethyl carbonate and ethylene carbonate are preferably used.
In addition, these carbonate esters may use multiple types together.

The amount of the carbonate used is preferably 0.4 to 2.0 mol, more preferably 0.5 to 1.5 mol, per 1 mol of polytetramethylene glycol.
Within this range, the desired polycarbonate polyol can be efficiently obtained at a sufficient reaction rate.

(Reaction temperature and reaction pressure)
The reaction temperature in the reaction of the present invention can be appropriately adjusted according to the type of carbonate ester, preferably 50 to 250°C, more preferably 70 to 230°C.
In addition, the reaction pressure in the reaction of the present invention is not particularly limited as long as the pressure allows the reaction to proceed while removing the low boiling point components, and is preferably normal pressure or reduced pressure.
Within this range, the intended polycarbonate polyol can be efficiently obtained without causing sequential reactions or side reactions.

(catalyst)
As the catalyst used in the reaction of the present invention, known transesterification catalysts can be used, such as lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, zinc, aluminum, titanium, zirconium, Metals such as cobalt, germanium, tin, and cerium, and their hydroxides, alkoxides, carboxylates, carbonates, hydrogencarbonates, sulfates, phosphates, nitrates, organic metals, etc., but preferably Sodium hydride, titanium tetraisopropoxide, titanium tetrabutoxide, zirconium tetrabutoxide, zirconium acetylacetonate, zirconium oxyacetate, dibutyltin dilaurate, dibutyltin dimethoxide, dibutyltin oxide are used.
In addition, these catalysts may use multiple types together.

The amount of the catalyst used is preferably 0.001 to 0.1 millimoles, more preferably 0.005 to 0.05 millimoles, more preferably 0.01 to 0.03 millimoles, per 1 mol of polytetramethylene glycol. millimoles.
Within this range, the intended polycarbonate polyol can be efficiently obtained without complicating post-treatment.
The catalyst may be used all at once at the start of the reaction, or may be used (added) in two or more portions at the start of the reaction and after the start of the reaction.

<<(a2) other polyols>>
(a) Structures derived from polyols may include structures derived from (a2) other polyols other than (a1) and (c) acidic group-containing polyols. As (a2) polyols having structures derived from other polyols, for example, high-molecular-weight polyols or low-molecular-weight polyols can be used. The type of (a2) other polyol is not particularly limited as long as it has two or more hydroxyl groups in one molecule.

Although the high molecular weight polyol is not particularly limited, it preferably has a number average molecular weight of 400 to 8,000. If the number average molecular weight is within this range, appropriate viscosity and good handleability can be obtained. In addition, it is easy to ensure the performance as a soft segment, and when a coating film is formed using the obtained aqueous resin dispersion containing the polyurethane resin, it is easy to suppress the occurrence of cracks. Furthermore, the reactivity of (a) the polyol and (b) the polyisocyanate becomes sufficient, and (A) the polyurethane prepolymer can be produced efficiently. More preferably, the high molecular weight polyol has a number average molecular weight of 400 to 4,000.

In this specification, the number average molecular weight is calculated based on the hydroxyl value measured according to JIS K 1577. Specifically, the hydroxyl value is measured and calculated by (56.1×1,000×valence)/hydroxyl value [mgKOH/g] by the terminal group determination method. In the above formula, the valence is the number of hydroxyl groups in one molecule.

Examples of high-molecular-weight polyols include, but are not limited to, polycarbonate polyols, polyester polyols, and polyether polyols. Polycarbonate polyols are preferred from the viewpoints of light resistance, weather resistance, heat resistance, hydrolysis resistance and oil resistance of aqueous resin dispersions containing polyurethane resins and coating films obtained from the aqueous resin dispersions.

Polycarbonate polyols are obtained by reacting one or more polyol monomers with carbonate esters or phosgene. Polycarbonate polyols obtained by reacting one or more polyol monomers with a carbonate ester are preferred because they are easy to produce and do not produce by-products with terminal chlorides.
The polycarbonate polyol as used in the present invention may contain in its molecule the same or less number of ether bonds or ester bonds than the average number of carbonate bonds in one molecule.

Examples of polyol monomers include, but are not limited to, aliphatic polyol monomers, polyol monomers having an alicyclic structure, aromatic polyol monomers, polyester polyol monomers, and polyether polyol monomers.

Examples of aliphatic polyol monomers include, but are not limited to, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1 ,8-octanediol, 1,9-nonanediol and other linear aliphatic diols; 2-methyl-1,3-propanediol, 2-methyl-1,5-pentanediol, 3-methyl-1,5 branched-chain aliphatic diols such as -pentanediol and 2-methyl-1,9-nonanediol; tri- or higher functional polyhydric alcohols such as trimethylolpropane and pentaerythritol.

The polyol monomer having an alicyclic structure is not particularly limited, but examples include 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanediol, 1,3-cyclopentanediol, 1, Examples include diols having an alicyclic structure in the main chain such as 4-cycloheptanediol, 2,7-norbornanediol, 1,4-bis(hydroxyethoxy)cyclohexane.

Examples of aromatic polyol monomers include, but are not limited to, 1,4-benzenedimethanol, 1,3-benzenedimethanol, 1,2-benzenedimethanol, 4,4′-naphthalenedimethanol, 3,4 '-naphthalenedimethanol is mentioned.

The polyester polyol monomer is not particularly limited, but for example, polyester polyols of hydroxycarboxylic acid and diol such as polyester polyol of 6-hydroxycaproic acid and hexanediol, and dicarboxylic acids such as polyester polyol of adipic acid and hexanediol. and polyester polyols with diols.

Carbonic acid esters are not particularly limited, and examples thereof include aliphatic carbonic acid esters such as dimethyl carbonate and diethyl carbonate, aromatic carbonic acid esters such as diphenyl carbonate, and cyclic carbonic acid esters such as ethylene carbonate. In addition, phosgene and the like, which can form polycarbonate polyols, can also be used. Of these, aliphatic carbonates are preferred, and dimethyl carbonate is particularly preferred, because of the ease of production of polycarbonate polyols.

As a method for producing a polycarbonate polyol from a polyol monomer and a carbonic acid ester, for example, a carbonic acid ester and an excessive number of moles of a polyol monomer with respect to the number of moles of the carbonic acid ester are added to a reactor, and the temperature is 160 to 200°C. , the reaction is performed at a pressure of about 50 mmHg for 5 to 6 hours, and then the reaction is further performed at 200 to 220° C. for several hours at a pressure of several mmHg or less. In the above reaction, it is preferable to carry out the reaction while withdrawing the by-produced alcohol out of the system. At that time, when the carbonate escapes from the system by azeotroping with the by-produced alcohol, an excess amount of the carbonate may be added. Moreover, in the above reaction, a catalyst such as titanium tetrabutoxide may be used.

The polycarbonate polyol is not particularly limited, but for example, a polycarbonate diol obtained by reacting 1,6-hexanediol with a carbonic acid ester, a mixture of 1,6-hexanediol and 1,5-pentanediol and a carbonic acid ester. A polycarbonate diol obtained by reacting a mixture of 1,6-hexanediol and 1,4-butanediol with a carbonate ester, a polycarbonate diol obtained by reacting a mixture of 1,4-cyclohexanedimethanol and a carbonate ester Polycarbonate diol, 1,6-hexanediol and 2- A polycarbonate diol obtained by reacting a mixture of methyl-1,5-pentanediol with a carbonate ester is mentioned.

Examples of polyester polyols include, but are not limited to, polyethylene adipate diol, polybutylene adipate diol, polyethylene butylene adipate diol, polyhexamethylene isophthalate adipate diol, polyethylene succinate diol, polybutylene succinate diol, and polyethylene sebacate diol. , polybutylene sebacate diol, poly-ε-caprolactone diol, poly(3-methyl-1,5-pentylene adipate) diol, polycondensate of 1,6-hexanediol and dimer acid.

The polyether polyol is not particularly limited as long as it is a polyol having ether bonds in the molecule, and may contain carbonate bonds and/or ester bonds in a number less than the average number of ether bonds in one molecule. The polyether polyol is preferably obtained by ring-opening polymerization of a cyclic ether or ring-opening polymerization of an epoxy compound, and is obtained by ether-bonding alkylene groups.

The number of carbon atoms in the main chain of the polyether polyol is not particularly limited, but the number of carbon atoms in the main chain is preferably 2 to 4 from the viewpoint of availability. From the viewpoint of suppressing a decrease in water resistance due to water absorption of polyurethane, it is desirable that the oxygen atom content is small, and the number of carbon atoms in the main chain is preferably 3 to 4, and particularly 4. preferable.

Polyether polyols include polytetramethylene ether glycol, polytetramethylene ether glycol having an alkyl side chain, polypropylene glycol, polyethylene glycol, and copolymers of two or more of these; random copolymerization of ethylene oxide and propylene oxide; Examples include coalescence, block copolymers, random copolymers and block copolymers of ethylene oxide and butylene oxide, such as polytetramethylene ether glycol, polytetramethylene ether glycol having an alkyl side chain, polypropylene glycol, and polyethylene. Glycols, copolymers of two or more of these, and the like are preferred.

As the low-molecular-weight polyol, a low-molecular-weight diol can also be used because of the ease of production of the aqueous polyurethane resin dispersion. The low-molecular-weight diol is not particularly limited, but includes, for example, those having a number average molecular weight of 60 or more and less than 400. Examples of low molecular weight diols include ethylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 2-butyl-2-ethyl- 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, 2-methyl- Aliphatic diols having 2 to 9 carbon atoms such as 1,8-octanediol, diethylene glycol, triethylene glycol and tetraethylene glycol; 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanediol , 1,4-bis(hydroxyethyl)cyclohexane, 2,7-norbornanediol, tetrahydrofurandimethanol, and 2,5-bis(hydroxymethyl)-1,4-dioxane. diols having Low molecular weight polyhydric alcohols such as trimethylolpropane, pentaerythritol and sorbitol can also be used as the low molecular weight polyol.

The ratio of (a1) polycarbonate polyol having a repeating unit represented by formula (1) in (a) polyol is preferably 10 to 100% by mass, more preferably 30 to 100% by mass, More preferably, it is 60-100% by mass. When the amount is more than 10% by mass, there is a tendency for a higher stress back property.

<<(b) Polyisocyanate>>
In the present invention, the structure derived from polyisocyanate refers to a partial structure of the molecular structure of polyisocyanate other than the groups involved in the polyurethane formation reaction.
(b) The polyisocyanate having a polyisocyanate-derived structure is not particularly limited, but examples thereof include aromatic polyisocyanates, aliphatic polyisocyanates, and alicyclic polyisocyanates.

Examples of aromatic polyisocyanates include 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate (TDI), 2,6-tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate ( MDI), 2,4-diphenylmethane diisocyanate, 4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-di isocyanatodiphenylmethane, 1,5-naphthylene diisocyanate, 4,4′,4″-triphenylmethane triisocyanate, m-isocyanatophenylsulfonyl isocyanate, p-isocyanatophenylsulfonyl isocyanate, but not limited to not.

Examples of aliphatic polyisocyanates include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 1,6,11-undecane triisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate. , 2,6-diisocyanatomethylcaproate, bis(2-isocyanatoethyl) fumarate, bis(2-isocyanatoethyl) carbonate, 2-isocyanatoethyl-2,6-diisocyanatohexanoate. include but are not limited to:

Examples of alicyclic polyisocyanates include isophorone diisocyanate (IPDI), 4,4′-dicyclohexylmethane diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated TDI), bis(2-isocyanato ethyl)-4-cyclohexene-1,2-dicarboxylate, 2,5-norbornane diisocyanate, 2,6-norbornane diisocyanate, but are not limited thereto.

As the polyisocyanate, those having two isocyanato groups per molecule can be used, but (A) an isocyanate per molecule such as triphenylmethane triisocyanate is used as long as the polyurethane prepolymer does not gel. Polyisocyanates with 3 or more groups can also be used.

Among polyisocyanates, alicyclic polyisocyanates are preferred from the viewpoint of improving the durability and tack-free properties of the coating film, and isophorone diisocyanate (IPDI) and 4,4'-dicyclohexylmethane are preferred from the viewpoint of easy control of the reaction. Diisocyanates (hydrogenated MDI) are particularly preferred.

In addition, polyisocyanate may use multiple types together.

<<(c) acidic group-containing polyol>>
In the present invention, the structure derived from the acidic group-containing polyol indicates a partial structure of the molecular structure of the acidic group-containing polyol other than the groups contributing to the polyurethane formation reaction.
(c) The acidic group-containing polyol having a structure derived from an acidic group-containing polyol contains two or more hydroxyl groups (excluding phenolic hydroxyl groups) and one or more acidic groups in one molecule. A carboxy group, a sulfonic acid group, a phosphoric acid group, a phenolic hydroxyl group, etc. are mentioned as an acidic group. (c) As the acidic group-containing polyol, one containing a compound having two hydroxyl groups and one carboxyl group in one molecule is preferred. (c) Acid group-containing polyols may be used in combination of multiple types.

(c) The acidic group-containing polyol is not particularly limited, but examples include dimethylolalkanoic acids such as 2,2-dimethylolpropionic acid and 2,2-dimethylolbutanoic acid, N,N-bishydroxyethylglycine, N,N-bishydroxyethylalanine, 3,4-dihydroxybutanesulfonic acid, 3,6-dihydroxy-2-toluenesulfonic acid. Among them, dimethylrollalkanoic acid having 4 to 12 carbon atoms containing two methylol groups is preferable from the viewpoint of availability. Among dimethylolalkanoic acids, 2,2-dimethylolpropionic acid is more preferable.

In the present invention, the total hydroxyl equivalent number of (a) polyol and (c) acidic group-containing polyol is preferably 120 to 1,000. If the number of hydroxyl group equivalents is within this range, the drying property and viscosity increase are likely to increase, the production of the aqueous resin dispersion containing the obtained polyurethane resin is easy, and a coating film excellent in terms of hardness is easily obtained. . From the viewpoint of the storage stability and dryability of the resulting aqueous polyurethane resin dispersion and the hardness of the coating film obtained by coating, the hydroxyl equivalent number is preferably 150 to 800, more preferably 200 to 700, and particularly preferably 300. ~600.

The hydroxyl group equivalent number can be calculated by the following formulas (1) and (2).
Number of hydroxyl group equivalents of each polyol = molecular weight of each polyol/number of hydroxyl groups of each polyol (excluding phenolic hydroxyl groups) (1)
Total number of hydroxyl group equivalents of polyols = M/total number of moles of polyols (2)
In the case of polyurethane resin (A), in formula (2), M is [[number of hydroxyl group equivalents of (a) polyol x number of moles of (a) polyol] + [number of hydroxyl group equivalents of (c) acidic group-containing polyol x (c) Number of moles of acidic group-containing polyol]].

(Method for producing aqueous polyurethane resin dispersion)
Next, a method for producing an aqueous polyurethane resin dispersion will be described. The method for producing an aqueous polyurethane resin dispersion comprises
a step (α) of reacting the (a) polyol and the (c) acidic group-containing polyol with the (b) polyisocyanate to obtain (A) a polyurethane prepolymer;
(A) a step of neutralizing the acidic groups of the polyurethane prepolymer (β);
(A) a step of dispersing a polyurethane prepolymer in an aqueous medium (γ);
(A) a step (δ) of reacting a polyurethane prepolymer with (A) a chain extender reactive with an isocyanato group of the polyurethane prepolymer (B).

(A) The step (α) of obtaining a polyurethane prepolymer may be performed under an inert gas atmosphere or under an air atmosphere. (A) In the step (γ) of dispersing the polyurethane prepolymer in the aqueous medium, the method for dispersing the polyurethane prepolymer in the aqueous medium is not particularly limited, but for example, stirring is performed using a homomixer, homogenizer, or the like. There are a method of adding (A) a polyurethane prepolymer to an aqueous medium, and a method of adding an aqueous medium to (A) a polyurethane prepolymer being stirred by a homomixer, a homogenizer, or the like.

In the step (δ) of reacting (A) the polyurethane prepolymer with (B) the chain extender reactive with the isocyanato group of the polyurethane prepolymer (A), the step (δ) is slowly carried out under cooling. In some cases, the reaction may be accelerated under heating conditions of 60° C. or less. The reaction time under cooling can be, for example, 0.5 to 24 hours, and the reaction time under heating conditions of 60° C. or lower can be, for example, 0.1 to 6 hours.
In the production of the aqueous polyurethane resin dispersion, either the step (β) or the step (γ) can be performed first, or both can be performed simultaneously. The step (γ) and the step (δ) may be performed simultaneously. Furthermore, the step (β), the step (γ), and the step (δ) may be performed simultaneously.
<<(A) polyurethane prepolymer>>
(A) The polyurethane prepolymer is obtained by reacting at least the (a) polyol, the (b) polyisocyanate, and the (c) acidic group-containing polyol. The (A) polyurethane prepolymer may contain a terminal terminator.

In the case of obtaining the (A) polyurethane prepolymer, the total amount of (a) polyol, (b) polyisocyanate, (c) acidic group-containing polyol, (B) chain extender described later, and optionally a terminal terminator is 100 mass. When expressed as parts, the ratio of the polyol (a) is preferably 30 to 90 parts by mass, more preferably 40 to 85 parts by mass, and particularly preferably 50 to 80 parts by mass. The ratio of the (c) acidic group-containing polyol is preferably 0.5 to 10 parts by mass, more preferably 3 to 7 parts by mass. The proportion of the terminal terminator can be appropriately determined according to the desired molecular weight of the polyurethane prepolymer (A).
By setting the proportion of the (a) polyol to 30 parts by mass or more, there is a tendency that the texture of the coating film obtained from the resulting aqueous polyurethane resin dispersion can be improved. The resulting aqueous polyurethane resin dispersion tends to further improve the tack-free property of the coating film.
By setting the ratio of the (c) acidic group-containing polyol to 0.5 parts by mass or more, the dispersibility of the obtained aqueous polyurethane resin in an aqueous medium tends to be improved, and the ratio should be 10 parts by mass or less. , the resulting aqueous polyurethane resin dispersion tends to have a high drying property. In addition, the water resistance of the coating film obtained by coating the aqueous polyurethane resin dispersion can be increased, and there is a tendency that the touch of the coating film obtained can be improved.

When obtaining the (A) polyurethane prepolymer, the ratio of the number of moles of isocyanato groups in the (b) polyisocyanate compound to the number of moles of all hydroxyl groups in the (a) polyol and (c) the acidic group-containing polyol is 1. 05 to 2.5 is preferred. By setting the ratio of the number of moles of the isocyanato groups of the polyisocyanate (b) to the number of moles of the total hydroxyl groups of the (a) polyol and the (c) acidic group-containing polyol to 1.05 or more, isocyanate is added to the molecular end. Since the amount of (A) polyurethane prepolymer having no group is reduced and (B) the number of molecules that do not react with the chain extender is reduced, it becomes easier to form a film after drying the aqueous polyurethane resin dispersion of the present invention. . Further, by setting the ratio of the number of moles of the isocyanato groups of the (b) polyisocyanate to the number of moles of the total hydroxyl groups of the (a) polyol and the (c) acidic group-containing polyol to 2.5 or less, the reaction system The amount of unreacted (b) polyisocyanate remaining in the solution is reduced, the (b) polyisocyanate and the (B) chain extender react efficiently, and undesired molecular elongation due to reaction with water is less likely to occur. Therefore, the aqueous polyurethane resin dispersion of the present invention can be appropriately prepared, and the storage stability is further improved. In addition, the dryability of the aqueous polyurethane resin dispersion obtained tends to be high, and the elastic modulus of the polyurethane film tends to be low. The ratio of the number of moles of isocyanato groups in the (b) polyisocyanate to the number of moles of all hydroxyl groups in the (a) polyol and the (c) acidic group-containing polyol is preferably 1.1 to 2.0, particularly preferably is between 1.3 and 1.8.

In the case of obtaining the (A) polyurethane prepolymer, the total amount of (a) polyol, (b) polyisocyanate, (c) acidic group-containing polyol, (B) chain extender described later, and optionally a terminal terminator In the case of 100 parts by mass, the amount of (b) polyisocyanate can be appropriately set according to the type or amount of (a) and (c) within a range that satisfies the above molar ratio conditions.

When the (A) polyurethane prepolymer is obtained from the (a) polyol, the (c) acidic group-containing polyol, and (b) the polyisocyanate, (a) and (c) are used in no particular order (b ) can be reacted with (a) and (c) may be simultaneously reacted with (b).

A catalyst can also be used in the reaction to obtain the polyurethane prepolymer. The catalyst is not particularly limited, but for example, a salt of a metal and an organic or inorganic acid such as a tin (tin)-based catalyst (trimethyltin laurylate, dibutyltin dilaurate, etc.) or a lead-based catalyst (lead octylate, etc.), Also included are organometallic derivatives, amine-based catalysts (triethylamine, N-ethylmorpholine, triethylenediamine, etc.), and diazabicycloundecene-based catalysts. Among them, dibutyltin dilaurate is preferable from the viewpoint of reactivity.

The reaction temperature for reacting the (a) polyol and the (c) acidic group-containing polyol with the (b) polyisocyanate is not particularly limited, but is preferably 40 to 150°C. By setting the reaction temperature to 40° C. or higher, the raw materials are sufficiently dissolved or the raw materials obtain sufficient fluidity, and the resulting polyurethane prepolymer (A) has a low viscosity and can be sufficiently stirred. can. By setting the reaction temperature to 150° C. or lower, the reaction can proceed without causing problems such as side reactions. More preferably, the reaction temperature is 60 to 120°C.

The reaction of the (a1) polycarbonate polyol, the (c) acidic group-containing polyol, and the (b) polyisocyanate may be carried out without a solvent or with the addition of an organic solvent. When the reaction is carried out without a solvent, the mixture of the (a1) polycarbonate polyol, the (c) acidic group-containing polyol, and the (b) polyisocyanate is preferably liquid. Examples of organic solvents include acetone, methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran, dioxane, dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, N-ethylpyrrolidone, β-alkoxypropionamide (Equad (registered trademark) manufactured by Idemitsu Kosan; Examples include Equamid M-100, Equamid B-100), dipropylene glycol dimethyl ether, and ethyl acetate. Among them, acetone, methyl ethyl ketone, and ethyl acetate are preferable because they can be removed by heating or reducing pressure after the polyurethane prepolymer is dispersed in water and subjected to chain extension reaction. Further, N-methylpyrrolidone, N-ethylpyrrolidone, and β-alkoxypropionamide are preferable because they act as film-forming aids when a coating film is produced from the obtained aqueous polyurethane resin dispersion. The amount of the organic solvent added is preferably 0.1 to 2.0 times the total amount of the (a) polyol, the (c) acidic group-containing polyol, and the (b) polyisocyanate on a mass basis. and more preferably 0.15 to 0.8 times.

The organic solvent used in the reaction of the (a) polyol, the (c) acidic group-containing polyol, and the (b) polyisocyanate is an organic solvent contained in the aqueous medium in which the polyurethane resin is dispersed, which will be described later. It can also serve as a solvent.

In the present invention, the acid value (AV) of (A) the polyurethane prepolymer is preferably 4 to 40 mgKOH/g, more preferably 6 to 32 mgKOH/g, particularly preferably 8 to 29 mgKOH/g. By setting the acid value of the polyurethane prepolymer to 4 mgKOH/g or more, there is a tendency that dispersibility in an aqueous medium and storage stability can be improved. In addition, by setting the acid value of the polyurethane prepolymer to 40 mgKOH/g or less, there is a tendency that the water resistance of the resulting polyurethane resin coating film can be increased and the flexibility of the resulting film can be increased. In addition, there is a tendency that the drying properties during coating film formation can be improved.
In the present invention, "(A) the acid value of the polyurethane prepolymer" means (A) a solvent used for producing the polyurethane prepolymer and a solvent for dispersing the (A) polyurethane prepolymer in an aqueous medium. It is the so-called acid value in the solid content excluding the neutralizer.
Specifically, the acid value of (A) the polyurethane prepolymer can be derived from the following formula (3).
[(A) acid value of polyurethane prepolymer]=[((c) number of millimoles of acidic group-containing polyol)×((c) number of acidic groups in one molecule of acidic group-containing polyol)]×56.11/[ Total mass of (a) polyol, (c) acidic group-containing polyol and (b) polyisocyanate] (3)
<Neutralizing agent>
In order to disperse the (A) polyurethane prepolymer in water, a basic component can be added to the (A) polyurethane prepolymer solution to neutralize the acidic group-containing polyol contained in the (A) polyurethane polymer.
As the neutralizing agent that can be used in (A) the step (β) of neutralizing the acidic groups of the polyurethane prepolymer, any base known to those skilled in the art can be used without particular limitation. Examples of neutralizing agents include trimethylamine, triethylamine, triisopropylamine, tributylamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N-phenyldiethanolamine, dimethylethanolamine, diethylethanolamine, and N-methylmorpholine. , organic amines such as pyridine; inorganic alkali salts such as sodium hydroxide and potassium hydroxide; and ammonia. Among them, organic amines can be preferably used, and tertiary amines can be more preferably used. Triethylamine is more preferable because it improves the dispersion stability. Here, the acidic group of the (A) polyurethane prepolymer means a carboxylic acid group, a sulfonic acid group, a phosphoric acid group, a phenolic hydroxyl group, and the like.
<Aqueous medium>
In the aqueous polyurethane resin dispersion, the polyurethane resin is dispersed in an aqueous medium. The aqueous medium includes water and an organic solvent.
Examples of the water include tap water, ion-exchanged water, distilled water, and ultrapure water. Among them, it is preferable to use ion-exchanged water in consideration of the availability and the fact that the particles become unstable due to the influence of salt.
Examples of the organic solvent include alcohol solvents such as methanol, ethanol, n-propanol and isopropanol; ketone solvents such as acetone and methyl ethyl ketone; polyalkylene glycols such as ethylene glycol, diethylene glycol and propylene glycol; and alkyl ethers of polyalkylene glycol. Solvent; lactam solvents such as N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, and the like.

<<(B) chain extender>>
A chain extender can be used for the purpose of increasing the molecular weight in the production of the aqueous polyurethane resin dispersion.
(B) Examples of the chain extender include compounds reactive with an isocyanato group. For example, ethylenediamine, 1,4-tetramethylenediamine, 2-methyl-1,5-pentanediamine, 1,4-butanediamine, 1,6-hexamethylenediamine, 1,4-hexamethylenediamine, 3-aminomethyl -Amines such as 3,5,5-trimethylcyclohexylamine, 1,3-bis(aminomethyl)cyclohexane, xylylenediamine, piperazine, adipoylhydrazide, hydrazine, 2,5-dimethylpiperazine, diethylenetriamine, and triethylenetetramine , ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol and other diols, polyalkylene glycols typified by polyethylene glycol, and water, among which primary diamines are preferred. These may use multiple types together.

The amount of the chain extender (B) to be added is preferably equal to or less than the equivalent of the isocyanato group serving as the chain extension starting point in the polyurethane prepolymer to be obtained, more preferably 0.7 to 0.99 equivalent of the isocyanato group. . By adding the (B) chain extender in an amount equal to or less than the equivalent weight of the isocyanato group, the molecular weight of the chain-extended urethane polymer is not reduced, and the coating film obtained by applying the obtained aqueous polyurethane resin dispersion is improved. It tends to be stronger. (B) The chain extender may be added after the polyurethane prepolymer is dispersed in water, or may be added during the dispersion. Chain extension can also be done with water. In this case, water as a dispersion medium also serves as a chain extender.

Specific examples of the method for producing the aqueous polyurethane resin dispersion include the following methods.
The (a) polyol and the (c) acidic group-containing polyol are reacted with the (b) polyisocyanate to obtain (A) a polyurethane prepolymer (step (α));
Next, the acidic groups of the (A) polyurethane prepolymer are neutralized (step (β)),
Dispersing the solution obtained in the step (β) in an aqueous medium (step (γ)),
The (A) polyurethane prepolymer dispersed in the dispersion medium is reacted with the (B) chain extender reactive with the isocyanato group of the (A) polyurethane prepolymer (step (δ)) to obtain an aqueous A polyurethane resin dispersion is obtained.

The proportion of the polyurethane resin in the aqueous polyurethane resin dispersion is preferably 5-60% by mass, more preferably 15-50% by mass.

The weight average molecular weight of the polyurethane resin of the present invention is usually about 25,000 to 10,000,000. More preferably 50,000 to 5,000,000, still more preferably 100,000 to 1,000,000. The weight average molecular weight is measured by gel permeation chromatography (GPC), and a conversion value obtained from a standard polystyrene calibration curve prepared in advance can be used. By setting the weight average molecular weight to 25,000 or more, there is a tendency that a good film can be obtained by drying the aqueous polyurethane resin dispersion. By setting the weight average molecular weight to 1,000,000 or less, there is a tendency that the drying property of the aqueous polyurethane resin dispersion can be further improved.

In addition, the aqueous polyurethane resin dispersion of the present invention may optionally contain a thickener, a photosensitizer, a curing catalyst, an ultraviolet absorber, a light stabilizer, an antifoaming agent, a plasticizer, a surface control agent, and a sedimentation agent. Additives such as inhibitors may also be added. A plurality of types of the additives may be used in combination. Also, the types of these additives are known to those skilled in the art, and can be used in amounts within the range generally used.

<Paint composition, coating agent composition and ink composition>
The present invention also relates to a paint composition, a coating agent composition and an ink composition containing the water-based polyurethane resin dispersion.
In addition to the aqueous polyurethane resin dispersion, other resins may be added to the coating composition, coating agent composition and ink composition of the present invention. Other resins include polyester resins, acrylic resins, polyether resins, polycarbonate resins, polyurethane resins, epoxy resins, alkyd resins, polyolefin resins, vinyl chloride resins, and the like. These may use multiple types together. Other resins preferably have one or more hydrophilic groups. Hydrophilic groups include a hydroxyl group, a carboxyl group, a sulfonic acid group, a polyethylene glycol group, and the like.

The other resin is preferably at least one selected from the group consisting of polyester resins, acrylic resins and polyolefin resins.

Polyester resins can usually be produced by an esterification reaction or a transesterification reaction between an acid component and an alcohol component. As the acid component, compounds commonly used as acid components in the production of polyester resins can be used. Examples of acid components that can be used include aliphatic polybasic acids, alicyclic polybasic acids, and aromatic polybasic acids.
The hydroxyl value of the polyester resin is preferably about 10-300 mgKOH/g, more preferably about 50-250 mgKOH/g, and even more preferably about 80-180 mgKOH/g. The acid value of the polyester resin is preferably about 1 to 200 mgKOH/g, more preferably about 15 to 100 mgKOH/g, even more preferably about 25 to 60 mgKOH/g.
The weight average molecular weight of the polyester resin is preferably 500 to 500,000, more preferably 1,000 to 300,000, even more preferably 1,500 to 200,000.

As the acrylic resin, a hydroxyl group-containing acrylic resin is preferable. A hydroxyl group-containing acrylic resin is obtained by combining a hydroxyl group-containing polymerizable unsaturated monomer and another polymerizable unsaturated monomer copolymerizable with the hydroxyl group-containing polymerizable unsaturated monomer, for example, by a solution polymerization method in an organic solvent, or in water. can be produced by copolymerization by a known method such as the emulsion polymerization method.
A hydroxyl group-containing polymerizable unsaturated monomer is a compound having one or more hydroxyl groups and one or more polymerizable unsaturated bonds in one molecule. For example, (meth) acrylic acid such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate and 2 to 8 carbon atoms ε-caprolactone modified product of these monoesters; N-hydroxymethyl (meth)acrylamide; allyl alcohol; (meth)acrylate having a polyoxyethylene chain with a hydroxyl group at the molecular end etc. can be mentioned.

The hydroxyl-containing acrylic resin preferably has an anionic functional group. Regarding the hydroxyl group-containing acrylic resin having an anionic functional group, for example, a polymerizable unsaturated monomer having an anionic functional group such as a carboxylic acid group, a sulfonic acid group, or a phosphoric acid group is used as one type of the polymerizable unsaturated monomer. It can be manufactured by using
The hydroxyl value of the hydroxyl-containing acrylic resin is preferably about 1 to 200 mgKOH/g, more preferably about 2 to 100 mgKOH/g, more preferably about 3 to 60 mgKOH, from the viewpoint of the storage stability of the composition and the water resistance of the resulting coating film. /g is more preferable.
Further, when the hydroxyl group-containing acrylic resin has an acid group such as a carboxyl group, the acid value of the hydroxyl group-containing acrylic resin is preferably about 1 to 200 mgKOH/g from the viewpoint of the water resistance of the resulting coating film, and 2 to 200 mgKOH/g. About 150 mgKOH/g is more preferable, and about 5 to 100 mgKOH/g is even more preferable.
The weight average molecular weight of the hydroxyl group-containing acrylic resin is preferably 1,000 to 200,000, more preferably 2,000 to 100,000, and still more preferably 3,000 to 50,000. be.

Examples of polyether resins include polymers or copolymers having an ether bond, such as polyoxyethylene-based polyethers, polyoxypropylene-based polyethers, polyoxybutylene-based polyethers, aromatics such as bisphenol A or bisphenol F. and polyethers derived from group polyhydroxy compounds.

Polycarbonate resins include polymers produced from bisphenol compounds, such as bisphenol A and polycarbonate.

Polyurethane resins include resins having urethane bonds obtained by reacting various polyol components such as acryl, polyester, polyether and polycarbonate with polyisocyanate.

Examples of epoxy resins include resins obtained by the reaction of bisphenol compounds and epichlorohydrin. Bisphenols include, for example, bisphenol A and bisphenol F.

Alkyd resins include polybasic acids and polyhydric alcohols such as phthalic acid, terephthalic acid, and succinic acid, as well as fats and fatty acids (soybean oil, linseed oil, coconut oil, stearic acid, etc.), natural resins (rosin, succinic acid, etc.). etc.) and other alkyd resins obtained by reacting modifiers.

As the polyolefin resin, a polyolefin resin obtained by polymerizing or copolymerizing an olefinic monomer with another monomer as appropriate according to a conventional polymerization method is dispersed in water using an emulsifier, or an olefinic monomer is appropriately mixed with another monomer. and a resin obtained by emulsion polymerization. In some cases, a so-called chlorinated polyolefin-modified resin obtained by chlorinating the above polyolefin resin may be used.
Examples of olefinic monomers include ethylene, propylene, 1-butene, 3-methyl-1-butene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-heptene, 1-hexene, 1- α-olefins such as decene and 1-dodecene; may
Other monomers copolymerizable with olefinic monomers include, for example, vinyl acetate, vinyl alcohol, maleic acid, citraconic acid, itaconic acid, maleic anhydride, citraconic anhydride, itaconic anhydride, and these monomers are , may be used in combination.

The coating composition, coating agent composition and ink composition of the present invention can contain a curing agent, whereby the coating film or multi-layer coating film obtained using the coating composition or the coating agent composition, the coating It is possible to improve the water resistance and the like of the film and the printed matter.

Examples of curing agents that can be used include amino resins, polyisocyanates, blocked polyisocyanates, melamine resins, and carbodiimides. A plurality of curing agents may be used in combination.

Amino resins include, for example, partially or fully methylolated amino resins obtained by reacting an amino component with an aldehyde component. Examples of the amino component include melamine, urea, benzoguanamine, acetoguanamine, steroguanamine, spiroguanamine, and dicyandiamide. Examples of aldehyde components include formaldehyde, paraformaldehyde, acetaldehyde, and benzaldehyde.

Examples of polyisocyanates include compounds having two or more isocyanato groups in one molecule, such as hexamethylene diisocyanate and trimethylhexamethylene diisocyanate.

Examples of the blocked polyisocyanate include those obtained by adding a blocking agent to the isocyanate group of the above-mentioned polyisocyanate. Examples of the blocking agent include phenolic compounds such as phenol and cresol, and aliphatic compounds such as methanol and ethanol. Alcohols, active methylenes such as dimethyl malonate and acetylacetone, mercaptans such as butyl mercaptan and dodecyl mercaptan, acid amides such as acetanilide and acetic amide, lactams such as ε-caprolactam and δ-valerolactam, succinimide and maleic acid imide; oxime-based blocking agents such as acetaldoxime, acetone oxime and methyl ethyl ketoxime; and amine-based blocking agents such as diphenylaniline, aniline and ethyleneimine.

Melamine resins include, for example, methylolmelamine such as dimethylolmelamine and trimethylolmelamine; alkyl-etherified products or condensates of these methylolmelamine; and condensates of alkyl-etherified products of methylolmelamine.

A coloring pigment, an extender pigment, and a luster pigment can be added to the paint composition, coating agent composition, and ink composition of the present invention.
Examples of coloring pigments include titanium oxide, zinc white, carbon black, molybdenum red, Prussian blue, cobalt blue, azo pigments, phthalocyanine pigments, quinacridone pigments, isoindoline pigments, threne pigments, and perylene pigments. These may use multiple types together. In particular, it is preferable to use titanium oxide and/or carbon black as the coloring pigment.
Examples of extender pigments include clay, kaolin, barium sulfate, barium carbonate, calcium carbonate, talc, silica, and alumina white. These may be used alone or in combination. In particular, barium sulfate and/or talc are preferably used as the extender, and barium sulfate is more preferably used.
Luster pigments that can be used include, for example, aluminum, copper, zinc, brass, nickel, aluminum oxide, mica, aluminum oxide coated with titanium oxide or iron oxide, and mica coated with titanium oxide or iron oxide. .

The paint composition, coating agent composition and ink composition of the present invention may optionally contain a thickener, a curing catalyst, an ultraviolet absorber, a light stabilizer, an antifoaming agent, a plasticizer, a surface control agent, and a sedimentation agent. The usual additives such as inhibitors can be included. These may use multiple types together.

Methods for producing the coating composition, coating agent composition and ink composition of the present invention are not particularly limited, but known production methods can be used. In general, paint compositions and coating agent compositions are produced by mixing the water-based polyurethane resin dispersion and the various additives described above, adding an aqueous medium, and adjusting the viscosity according to the application method. be done.

Examples of the material to be coated with the coating composition, the material to be coated with the coating agent composition, or the material to be coated with the ink composition include metals, plastics, inorganic substances, wood, and the like.

Examples of the coating method of the coating composition or the coating method of the coating agent composition include bell coating, spray coating, roll coating, shower coating and dip coating. Examples of methods for applying the ink composition include inkjet printing, flexographic printing, gravure printing, reverse offset printing, sheet-fed screen printing, and rotary screen printing.

The thickness of the coating film after curing is not particularly limited, but a thickness of 1 to 100 μm is preferable. More preferably, a coating film having a thickness of 3 to 50 μm is formed.

<Polyurethane resin film>
The present invention further relates to a polyurethane resin film obtained from the above aqueous polyurethane resin dispersion.

A polyurethane resin film can also be obtained using an aqueous polyurethane resin dispersion. A polyurethane resin film can be obtained by applying an aqueous polyurethane resin dispersion to a release substrate, drying and curing by means such as heating, and then peeling the cured polyurethane resin from the release substrate. .

Examples of the heating method include a heating method using the reaction heat of the mold itself, and a heating method using the reaction heat and active heating of the mold. For positive heating of the mold, there is a method in which the mold is placed in a hot air oven, an electric furnace, or an infrared induction heating furnace.

The heating temperature is preferably 40 to 200°C, more preferably 60 to 160°C. By heating at such a temperature, drying can be performed more efficiently. The heating time is preferably 0.0001 to 20 hours, more preferably 1 to 10 hours. By setting it as such a heating time, a polyurethane resin film with higher hardness can be obtained. Drying conditions for obtaining a polyurethane resin film include, for example, heating at 120° C. for 3 to 10 seconds.

EXAMPLES Next, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these. "%" is based on weight unless otherwise specified.

[Example 1]
In a reactor equipped with a stirrer and a heater, polycarbonate polyol (Ethanacol (registered trademark) UT200 manufactured by Ube Industries; number average molecular weight 2000; hydroxyl value 56.1 mg KOH / g; polyol monomer is polytetramethylene glycol (number average molecular weight 250) and a carbonate ester, 300.4 g), 2,2-dimethylolpropionic acid (15.77 g) as an acidic group-containing polyol, and isophorone diisocyanate (83.39 g) as an isocyanate. ) in N-methylpyrrolidone (134.25 g) as an organic solvent in the presence of dibutyltin dilaurate (0.3 g) under a nitrogen atmosphere at 80-90° C. for 6 hours. The NCO group content at the end of the urethanization reaction was 1.67% by mass. After the reaction mixture was brought to 80° C., triethylamine (11.9 g) was added and stirred for 30 minutes. A 517.2 g portion of the reaction mixture was extracted and added to water (746.4 g) with strong stirring, and then a 35% aqueous solution of 2-methyl-1,5-pentanediamine (29.6 g) was added as a chain extender. In addition, an aqueous polyurethane resin dispersion was obtained.
50 parts by weight of the resulting aqueous polyurethane resin dispersion, 40 parts by weight of titanium paste (aqueous paste with a titanium oxide powder content of 60%), 5 parts by weight of an aqueous pigment dispersion (manufactured by Toyocolor Co., Ltd.: EMF PINK 2B-1), 1 part by weight of 25% aqueous ammonia (manufactured by Wako Pure Chemical Industries, Ltd.) and 3.5 parts by weight of an alkali thickener (Parachem Japan Co., Ltd.: Parabond 10-N) are mixed to obtain a textile printing ink. rice field. Subsequently, using a 150-mesh screen and a urethane rubber squeegee, the ink for textile printing was printed twice on the white cotton sheeting knit fabric. The printed material was dried at 150° C. for 2 minutes to obtain a printed material.

[Comparative Example 1]
Polycarbonate polyol of Example 1 (Ethanacol (registered trademark) UT200 manufactured by Ube Industries; number average molecular weight 2000; hydroxyl value 56.1 mg KOH / g; polyol monomer reacts polytetramethylene glycol (number average molecular weight 250) with carbonate ester Polycarbonate polyol (Ethanacol (registered trademark) UH200 manufactured by Ube Industries; number average molecular weight 2000; hydroxyl value 56.1 mgKOH/g; polyol monomer reacts hexanediol with carbonate ester) Polycarbonate diol obtained by

[Comparative Example 2]
Polycarbonate polyol of Example 1 (Ethanacol (registered trademark) UT200 manufactured by Ube Industries; number average molecular weight 2000; hydroxyl value 56.1 mg KOH / g; polyol monomer reacts polytetramethylene glycol (number average molecular weight 250) with carbonate ester Polytetramethylene glycol (manufactured by Mitsubishi Chemical Corporation; PTMG: number average molecular weight: 2000; hydroxyl value: 56.1 mgKOH/g) was used instead of the polycarbonate diol obtained by drying.

[Comparative Example 3]
Polycarbonate polyol of Example 1 (Ethanacol (registered trademark) UT200 manufactured by Ube Industries; number average molecular weight 2000; hydroxyl value 56.1 mg KOH / g; polyol monomer reacts polytetramethylene glycol (number average molecular weight 250) with carbonate ester Polycarbonate polyol (Ethanacol (registered trademark) UH200 manufactured by Ube Industries; number average molecular weight 2000; hydroxyl value 56.1 mgKOH/g; polyol monomer reacts hexanediol with carbonate ester) and polytetramethylene glycol (manufactured by Mitsubishi Chemical Corporation; PTMG: number average molecular weight: 2000; hydroxyl value: 56.1 mgKOH/g) were used at the mass % shown in the table.

(Evaluation of tactile sensation)
Flexibility was evaluated while pinching the printed material with fingertips. Good flexibility was evaluated as ◯, and poor flexibility and hard as x.

(Followability evaluation)
When the printed matter of the textile ink was pulled, the printed film was rated as ◯ when it did not crack, and x when it was cracked.

(Evaluation of tack-free property)
The edges of the printed material were folded back so that the printed surfaces faced inward, and a load was applied with fingertips and pressed for 3 seconds. After the load was removed, ⊚ indicates no sticking at all, O indicates almost no sticking, and X indicates slight sticking.

(Evaluation of stress back property (hysteresis loss))
[How to make a film]
Each of the aqueous polyurethane resin dispersions of Example 1 and Comparative Examples 1 to 3 was uniformly coated on a glass plate so that the film thickness after drying was about 0.08 mm. After drying at 80° C. for 2 hours and further at 120° C. for 2 hours, the resulting polyurethane resin film was peeled off from the glass plate and subjected to the following evaluations.
[Measurement of hysteresis loss]
The polyurethane resin film was stretched by a method according to JIS K 7113 until the tensile elongation reached 200%. Thereafter, the change in elongation and tensile stress were measured when the same test piece was returned to its original elongation. Hysteresis loss was calculated by the method described in JP-A-2016-204595. A smaller number indicates a smaller hysteresis loss and a higher stretch-back property.

The results of Example 1 and Comparative Examples 1 to 3 are shown in Table 1 below.

A comparison between Example 1 and Comparative Examples 1 to 3 shows that the water-based polyurethane resin of the present invention is excellent in terms of touch feeling, followability, tack-free property and stress back property (low hysteresis loss).

The aqueous polyurethane resin dispersion of the present invention can be widely used as a raw material for paints, coating agents, primers, adhesives, inks, films, fiber treatment agents and the like.

Claims (2)

An ink composition containing an aqueous polyurethane resin dispersion,
The aqueous polyurethane resin dispersion has (a) a polyol-derived structure, (b) a polyisocyanate-derived structure, and (c) an acidic group-containing polyol-derived structure,
The (a) polyol-derived structure has (a1) a structure derived from a polycarbonate polyol having a repeating unit represented by the following formula (1),
In the production of the aqueous polyurethane resin dispersion, (B) a chain extender and a terminal terminator may be used, and (a) polyol, (b) polyisocyanate, (c) acidic group-containing polyol, (B) chain extender The ink composition, wherein the ratio of the (a) polyol is 30 to 80 parts by mass, when the total amount of the agent and the terminal terminator is 100 parts by mass.

(m and n represent numbers greater than 1.) In the production of the aqueous polyurethane resin dispersion, the (A) polyurethane prepolymer is obtained by reacting at least the (a) polyol, the (b) polyisocyanate, and the (c) acidic group-containing polyol. is a
The (A) polyurethane prepolymer has an acid value (AV) of 4 to 40 mgKOH/g,
The aqueous polyurethane resin dispersion comprises (A) the step of neutralizing the acidic groups of the polyurethane prepolymer, the step of dispersing the (A) polyurethane prepolymer in an aqueous medium, and the (A) polyurethane prepolymer, 2. The ink composition according to claim 1, obtained by reacting (A) the isocyanato group of the polyurethane prepolymer with a reactive (B) chain extender.