JP2021054938A - Aqueous polyurethane resin dispersion and use thereof - Google Patents

Abstract

To provide an aqueous polyurethane resin dispersion that gives high smoothness when forming a coating film.SOLUTION: An aqueous polyurethane resin dispersion is a dispersion in which a polyurethane resin containing (A) a polyisocyanate-derived structure, (b1) a polyetherpolyol-derived structure, (b2) a polycarbonate polyol-derived structure, and (c) an acidic group-containing polyol-derived structure is dispersed in an aqueous medium, where the (A) polyisocyanate-derived structure is a C8-14 polyisocyanate-derived structure having a ring structure.SELECTED DRAWING: None

Description

The present invention relates to an aqueous polyurethane resin dispersion in which a polyurethane resin is dispersed in an aqueous medium, and more particularly to an aqueous polyurethane resin that gives a coating film having high smoothness when applied to a substrate. The present invention also comprises a method for producing the aqueous polyurethane resin dispersion, a coating composition containing the aqueous polyurethane resin dispersion, a coating composition, an ink composition, and the polyurethane resin dispersion. The present invention relates to a polyurethane resin film obtained by drying an object.

Since the aqueous polyurethane resin dispersion is an environment-friendly material capable of reducing volatile organic compounds as compared with the conventional solvent-based urethane, it is a material that is being replaced with solvent-based polyurethane.
Since the water-based polyurethane resin dispersion has excellent adhesion to the base material, abrasion resistance, impact resistance, solvent resistance, etc., paper, plastics, etc. can be used as paints, inks, adhesives, and various coating agents. Widely used in films, metals, rubbers, elastomers, textile products, etc.
In coating applications, it is often applied and used on the epidermis of a substrate.

It has been reported that a coating film having high drying property and high hardness can be obtained by using a polycarbonate polyol having an alicyclic structure and a polyether polyol in combination as the polyol (Patent Document 1).
Further, it has been found that a polycarbonate polyol having an alicyclic structure, a hot melt adhesive obtained by reacting a polyether polyol with an isocyanate, has high initial adhesion and durability (Patent Document 2). ).

International Publication No. 2011/021500 Japanese Unexamined Patent Publication No. 2016-000785

However, regarding an aqueous polyurethane resin dispersion in which a polycarbonate polyol and a polyether polyol are used in combination, an aqueous polyurethane resin dispersion that gives high smoothness at the time of coating film formation has not been proposed. An object of the present invention is to provide an aqueous polyurethane resin dispersion that gives high smoothness at the time of coating film formation.

The present invention has been made to solve the above problems, and includes (a) a structure derived from a polyisocyanate, (b1) a structure derived from a polyether polyol, (b2) a structure derived from a polycarbonate polyol, and (c). ) A dispersion in which a polyurethane resin having a structure derived from an acidic group-containing polyol is dispersed in an aqueous medium.
It has been found that the above-mentioned problems can be solved by an aqueous polyurethane resin dispersion in which the structure derived from (a) polyisocyanate is a structure derived from polyisocyanate having a ring structure and having 8 to 14 carbon atoms.
The present invention relates to the following.
[1] A polyurethane resin having (a) a structure derived from polyisocyanate, (b1) a structure derived from a polyether polyol, (b2) a structure derived from a polycarbonate polyol, and (c) a structure derived from an acidic group-containing polyol. A dispersion dispersed in an aqueous medium,
(A) An aqueous polyurethane resin dispersion in which the structure derived from polyisocyanate is a structure derived from polyisocyanate having a ring structure and having 8 to 14 carbon atoms.
[2] (a) From the group consisting of isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, tetramethylxylylene diisocyanate and tetramethylcyclohexyldiisocyanate, the structure derived from polyisocyanate having 8 to 14 carbon atoms having a ring structure. The aqueous polyurethane resin dispersion of [1], which comprises at least one selected.
[3] (b2) The structure derived from the polycarbonate polyol is a structure derived from a polycarbonate polyol obtained from a alicyclic structure and a polyol monomer having two or more primary hydroxyl groups, or an aliphatic polyol having two or more primary hydroxyl groups. The aqueous polyurethane resin dispersion of [1] to [2], which comprises a structure derived from a polycarbonate polyol obtained from a monomer, an alicyclic structure, and a polyol monomer having two or more primary hydroxyl groups.
[4] The aqueous polyurethane resin dispersion of [3], wherein the alicyclic structure content of the structure derived from the polycarbonate resin (b2) with respect to the polyurethane resin solid content is 1 to 20% by mass.
[5] The aqueous polyurethane resin dispersion according to any one of [1] to [4], which further contains an organic solvent and the organic solvent is a non-pyrrolidone solvent.
[6] A smooth substrate is coated with a cured film thickness of 100 μm, dried, and then the cured coating film is applied using a No. 5 dumbbell-shaped test piece by a method in accordance with JIS K 7311. The aqueous polyurethane resin dispersion according to any one of [1] to [5], wherein the measured tensile elongation is 600 to 2000%.
[7] A coating composition containing the aqueous polyurethane resin dispersion according to any one of [1] to [6].
[8] A coating agent composition containing the aqueous polyurethane resin dispersion according to any one of [1] to [6].
[9] An ink composition containing the aqueous polyurethane resin dispersion according to any one of [1] to [6].
[10] An adhesive composition containing the aqueous polyurethane resin dispersion according to any one of [1] to [6].
[11] A polyurethane resin film obtained by drying and curing a composition containing the aqueous polyurethane resin dispersion according to any one of [1] to [6].

INDUSTRIAL APPLICABILITY The present invention provides an aqueous polyurethane resin dispersion that exhibits high smoothness when formed into a coating film.

Hereinafter, embodiments of the present invention will be described in detail. In a polymer compound like the present invention, a product having a large number of structures can be obtained by reacting a plurality of types of raw material compounds. Therefore, even if a large number of included structures can be described by a general formula, the polymer compound is not uniquely indicated by the structure. In addition, it is difficult to directly measure and identify the physical characteristics by instrumental analysis or the like or to distinguish them from existing compounds. Therefore, in the present invention, a polymer compound such as "aqueous polyurethane resin dispersion" may be specified by a production method, if necessary.

<Aqueous polyurethane resin dispersion>
The aqueous polyurethane resin dispersion is an aqueous dispersion of a polyurethane resin in which a polyurethane resin is dispersed in an aqueous medium. The "polyurethane resin emulsion" is also referred to as a "water-dispersible polyurethane resin" or a "water-based polyurethane resin dispersion".
The aqueous polyurethane resin dispersion has (a) a structure derived from polyisocyanate, (b1) a structure derived from a polyether polyol, (b2) a structure derived from a polycarbonate polyol, and (c) a structure derived from an acidic group-containing polyol. Have and
The structure derived from (a) polyisocyanate includes a structure derived from polyisocyanate having a ring structure and having 8 to 14 carbon atoms.
That is, the polyurethane resin has (a) a structure derived from polyisocyanate, (b1) a structure derived from a polyether polyol, (b2) a structure derived from a polycarbonate polyol, and (c) a structure derived from an acidic group-containing polyol. And
The resin is dispersed in an aqueous medium,
The structure derived from (a) polyisocyanate includes a structure derived from polyisocyanate having a ring structure and having 8 to 14 carbon atoms.
The aqueous polyurethane resin dispersion can include, as an arbitrary structure, (d) a structure derived from a chain extender and (e) a structure derived from a terminal terminator, and (c') a portion of the neutralizing agent as a counterion. It may exist. A plurality of types of arbitrary structures may be used in combination.
The "structure derived from polyisocyanate" refers to a partial structure of the molecular structure of polyisocyanate other than the bonding group involved in the urethanization reaction. The same applies to other structures.

The structure derived from (a) polyisocyanate means a partial structure of the molecular structure of (a) polyisocyanate other than the groups involved in the polyurethane-forming reaction. The structure derived from (a) polyisocyanate is introduced into polyurethane by (a) polyisocyanate. The same applies to (b1), (b2), and (c). Further, the structure derived from (d) the chain extender means a partial structure of the molecular structure of the (d) chain extender other than the group involved in the chain extension reaction. The structure derived from (d) the chain extender is introduced into the polyurethane by (d) the chain extender. Further, the structure derived from the (e) terminal terminator means a partial structure of the molecular structure of the (e) terminal terminator other than the group involved in the reaction of terminating the urethanization reaction and / or the chain extension reaction. .. The structure derived from (e) end terminator is introduced into polyurethane by (e) end terminator.

<(A) Polyisocyanate>
(A) The polyisocyanate has a ring structure and has 8 to 14 carbon atoms. For example, a polyisocyanate having an aromatic ring structure with 8 to 14 carbon atoms and a polyisocyanate having an alicyclic structure with 8 to 14 carbon atoms can be mentioned. Among the polyisocyanates, a polyisocyanate having 10 to 14 carbon atoms is preferable from the viewpoint of smoothness and tensile elongation of the coating film. Further, among the polyisocyanates, diisocyanate is preferable.
Examples of the polyisocyanate having 8 to 14 carbon atoms having an aromatic ring structure include tolylene diisocyanate (TDI), xylene diisocyanate (XDI), tetramethylxylene diisocyanate (TMXDI) and the like.
Examples of the polyisocyanate having carbon atoms 8 to 14 having an alicyclic structure include isophorone diisocyanate (IPDI), hydrogenated xylylene diisocyanate (H6XDI), hydrogenated tolylene diisocyanate (H6TDI), and tetramethylcyclohexyldiisocyanate (H6TMXDI). , Bis (2-isocyanatoethyl) -4-cyclohexene-1,2-dicarboxylate, from the viewpoint of coating smoothness, isophorone diisocyanate (IPDI), xylylene diisocyanate (XDI), hydrogenated xylylene It is preferable to contain at least one polyisocyanate selected from the group consisting of isocyanate (H6XDI), tetramethylxylylene diisocyanate (TMXDI) and tetramethylcyclohexyldiisocyanate (H6TMXDI), from the viewpoint of smoothness and tensile elongation of the coating film. Therefore, it is more preferable to contain at least one polyisocyanate selected from the group consisting of hydrogenated xylylene diisocyanate (H6XDI) and tetramethylxylylene diisocyanate (TMXDI).
A plurality of types of polyisocyanates may be used in combination.

<(B1) Polyether polyol>
The polyether polyol is not particularly limited as long as it is a polyol having an ether bond in the molecule, and may contain a number of carbonate bonds and / or ester bonds that is less than the average number of ether bonds in one molecule. The polyether polyol is preferably one in which an alkylene group is ether-bonded, which is obtained by, for example, ring-opening polymerization of a cyclic ether or ring-opening polymerization of an epoxy compound. The carbon number of the main chain of the polyether polyol is not particularly limited, but the carbon number of the main chain is preferably 2 to 4 from the viewpoint of availability. Further, from the viewpoint of suppressing the decrease in water resistance of polyurethane due to water absorption, the carbon number of the main chain is more preferably 3 to 4, and particularly preferably 4.
Examples of the polyether polyol include polytetramethylene ether glycol, polytetramethylene ether glycol having an alkyl side chain, polypyrropylene glycol, and a copolymer of two or more of these.
The (b1) polyether polyol preferably contains polytetramethylene ether glycol from the viewpoint of obtaining a coating film having excellent water resistance and high smoothness, and (b1) the polytetramethylene ether glycol in the (b1) polyether polyol. Is more preferably 80% by mass or more, further preferably 90% by mass or more, and 100% by mass ((b1) as a polyether polyol, a polyether polyol other than polytetramethylene ether glycol. Is not included) is particularly preferable.

<(B2) Polycarbonate polyol>
The polycarbonate polyol is not particularly limited as long as it is a polyol having a carbonate bond in the molecule. As such a polycarbonate polyol, for example, a polyol monomer such as a diol is preferably carbonate-bonded. Further, the polycarbonate polyol may contain an ether bond or an ester bond in a number equal to or less than the average number of carbonate bonds in one molecule of the polycarbonate polyol.

Polycarbonate polyol is obtained by reacting one or more kinds of polyol monomers with a carbonic acid ester or phosgene. A polycarbonate polyol compound obtained by reacting one or more kinds of polyol monomers with a carbonic acid ester is preferable because it is easy to manufacture from the viewpoint of safety and handling of reagents, and there is no by-production of terminal chlorinated products. ..
The polycarbonate polyol may contain as many ether bonds and ester bonds as the average number of carbonate bonds in one molecule or less in the molecule.
Examples of the raw material of the polycarbonate polyol include an aliphatic polyol monomer, a polyol monomer having an alicyclic structure, an aromatic polyol monomer, a polyester polyol monomer, and a polyether polyol monomer.
As a raw material for the polycarbonate polyol, it is preferable to use a polyol monomer having an alicyclic structure, and it is more preferable to use a polyol monomer having an alicyclic structure and two or more primary hydroxyl groups. Further, as a raw material for the polycarbonate polyol, a plurality of types of the polyol monomers may be used in combination. For example, it is preferable to use an aliphatic polyol monomer and a polyol monomer having an alicyclic structure in combination, and the aliphatic polyol monomer and the poly It may be used in combination with an ether polyol monomer.

The aliphatic polyol monomer is not particularly limited, but for example, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,5-hexanediol, 1,6-hexanediol, 1 , 7-Heptanediol, 1,8-octanediol, 1,9-nonanediol and other linear aliphatic diols; 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propane Branched chain aliphatic diols such as diol, 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-1,9-nonanediol; trimethylolpropane, pentaerythritol and the like. Examples thereof include polyhydric alcohols having trifunctionality or higher.
A plurality of types of aliphatic polyol monomers may be used in combination.

The polyol monomer having an alicyclic structure is not particularly limited, and examples thereof include a polyol having an alicyclic group having 5 to 12 carbon atoms. Specifically, 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanediol, 1,3-cyclopentanediol, 1,4-cycloheptandiol, 2,5-bis ( Hydroxylmethyl) -1,4-dioxane, 2,7-norbornanediol, tetrahydrofurandimethanol, 1,4-bis (hydroxyethoxy) cyclohexane, isosorbide and the like can be mentioned.
Among the polyol monomers having an alicyclic structure, a polyol monomer having an alicyclic structure and two or more primary hydroxyl groups is preferable, and 1,4-cyclohexanedimethanol is more preferable.
A plurality of types of polyol monomers having an alicyclic structure may be used in combination.

The aromatic polyol monomer is not particularly limited, and is, for example, 1,4-benzenedimethanol, 1,3-benzenedimethanol, 1,2-benzenedimethanol, 4,4'-naphthalenemethanol, 3,4. '-Naphthalene methanol and the like can be mentioned.
The polyester polyol monomer is not particularly limited, and is, for example, a polyester polyol containing a hydroxycarboxylic acid and a diol such as a polyester polyol containing 6-hydroxycaproic acid and hexanediol, and a dicarboxylic acid such as a polyester polyol containing adipic acid and hexanediol. And polyester polyol with diol and the like.
A plurality of types of aromatic polyol monomers may be used in combination.
The polyether polyol monomer is not particularly limited, and examples thereof include polyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol.
A plurality of types of polyether polyol monomers may be used in combination.

The carbonic acid ester is 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 ditril carbonate, and cyclic carbonates such as ethylene carbonate and propylene carbonate. .. In addition, phosgene or the like capable of producing a polycarbonate polyol can also be used. Of these, aliphatic carbonic acid esters and cyclic carbonic acid esters are preferable, and dimethyl carbonate, diethyl carbonate, and ethylene carbonate are particularly preferable because of the ease of production of the polycarbonate polyol.

As a method for producing a polycarbonate polyol from a polyol monomer and a carbonic acid ester, for example, a carbonic acid ester and a polyol monomer having an excessive number of moles relative to the number of moles of the carbonic acid ester are added to the reactor, and the temperature is 160 under normal pressure. A method of reacting at ~ 200 ° C. for 12 hours and then further reacting at 200 to 220 ° C. for several hours at a pressure of 6.7 kPa or less can be mentioned. In the above reaction, it is preferable to carry out the reaction while extracting the by-produced alcohol from the system. At that time, if the carbonic acid ester escapes from the system by azeotropically boiling with the alcohol produced as a by-product, an excessive amount of the carbonic acid ester may be added. Further, in the above reaction, a catalyst such as titanium tetrabutoxide may be used.

From the viewpoint of smoothness and toughness when the aqueous polyurethane resin dispersion is used as a coating film, the structure derived from (b2) polycarbonate polyol is
(I) A structure derived from a polycarbonate polyol having an alicyclic structure and a polyol monomer having two or more primary hydroxyl groups, or (ii) an aliphatic polyol monomer having two or more primary hydroxyl groups and an alicyclic structure. And preferably contains a structure derived from a polycarbonate polyol obtained from a polyol monomer having two or more primary hydroxyl groups.

A polycarbonate polyol having an alicyclic structure and a structure derived from a polycarbonate polyol obtained from a polyol monomer having two or more primary hydroxyl groups is obtained as a polyol monomer from a polyol monomer having an alicyclic structure and two or more primary hydroxyl groups. Be done. Of these, a polycarbonate polyol obtained from 1,4-cyclohexanedimethanol is preferable.
(B2) The proportion of the alicyclic structure in the structure derived from the polycarbonate polyol and the structure derived from the polycarbonate polyol obtained from the polyol monomer having two or more primary hydroxyl groups is preferably 80% by mass or more, more preferably. It is 90% by mass, particularly preferably 100% by mass.

Two polycarbonate polyols having a structure derived from a polycarbonate polyol obtained from an aliphatic polyol monomer having two or more primary hydroxyl groups and an alicyclic structure and a polyol monomer having two or more primary hydroxyl groups are used as polyols. It is obtained from the above-mentioned aliphatic polyol monomer having a primary hydroxyl group and a polyol monomer having an alicyclic structure and two or more primary hydroxyl groups. Of these, a polycarbonate polyol obtained from 1,6-hexanediol and 1,4-cyclohexanedimethanol is preferable, and a polycarbonate polyol obtained from 1,6-hexanediol and 1,4-cyclohexanedimethanol is preferable. More preferably, a polycarbonate polyol having a molar ratio of 1,6-hexanediol to 1,4-cyclohexanedimethanol of 1: 3, 1: 1 or 3: 1.
(B2) Ratio of the structure derived from the polycarbonate polyol obtained from the aliphatic polyol monomer having two or more primary hydroxyl groups and the alicyclic structure and the polyol monomer having two or more primary hydroxyl groups in the structure derived from the polycarbonate polyol. Is preferably 80% by mass or more, more preferably 90% by mass, and particularly preferably 100% by mass.

The number average molecular weight of the polycarbonate polyol is preferably 100 to 4,000, more preferably 300 to 3,000, and particularly preferably 500 to 2,500. Within this range, an aqueous polyurethane resin dispersion having excellent smoothness and toughness when formed into a coating film can be obtained.

<(C) Acid group-containing polyol>
(C) The acidic group-containing polyol is a polyol having at least one acidic group in the molecule. The acidic group is not particularly limited, and examples thereof include a carboxy group, a sulfonyl group, a phosphoric acid group, and a phenolic hydroxyl group. The type of the acidic group-containing polyol is not particularly limited, but specifically, dimethylol alkanoic acid such as 2,2-dimethylol propionic acid and 2,2-dimethylol butanoic acid, and N, N-bishydroxyethylglycine. , N, N-bishydroxyethylalanine, 3,4-dihydroxybutanesulfonic acid, 3,6-dihydroxy-2-toluenesulfonic acid and the like. Among these, from the viewpoint of availability, an alkanoic acid containing two methylol groups and having 4 to 12 carbon atoms (dimethylolalkanoic acid) is preferable, and among them, 2,2-dimethylolpropionic acid is preferable.
(C) A plurality of types of acidic group-containing polyols may be used in combination.

<(C') Neutralizer>
The (c') neutralizing agent is not particularly limited as long as it can neutralize the acidic group of the (c) acidic group-containing polyol, and can be appropriately selected depending on the type of the acidic group and the like. Specific examples of the (c') neutralizing agent include, for example, trimethylamine, triethylamine, triisopropylamine, tributylamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N-phenyldiethanolamine, and dimethylethanolamine. , Diethylethanolamine, N-methylmorpholine, pyridine, 2- (dimethylamino) -2-methyl-1-propanol (DMAP) and other organic amines; sodium hydroxide, potassium hydroxide and other inorganic alkali salts; ammonia and the like. Can be mentioned. The neutralizing agent (c') is preferably an organic amine, more preferably a tertiary amine, and particularly preferably a triethylamine.
(C') A plurality of types of neutralizing agents may be used in combination.

<(D) Chain extender>
(D) The chain extender is not particularly limited, and examples thereof include compounds having two or more groups that react with isocyanato groups, and examples thereof include ethylenediamine, 1,4-tetramethylenediamine, and 2-methyl-1,5-. Pentandiamine, 1,4-butanediamine, 1,6-hexamethylenediamine, 1,4-hexamethylenediamine, 3-aminomethyl-3,5,5-trimethylcyclohexylamine, 1,3-bis (aminomethyl) Polyamine compounds such as cyclohexane, xylylenediamine, piperazin, adipoil hydrazide, hydrazine, 2,5-dimethylpiperazin, diaminetriamine, triethylenetetramine; ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexane Diol compounds such as diols; polyalkylene glycols typified by polyethylene glycol; water, among which polyamine compounds are preferable, diamine compounds are more preferable, and primary diamine compounds are particularly preferable.
(D) A plurality of types of chain extenders may be used in combination.

<(E) Terminal terminator>
(E) The terminal terminator is a component capable of stopping the urethanization reaction and / or the chain extension reaction at the end of the polyurethane resin. (E) Examples of the terminal terminator include a compound having one group that reacts with an isocyanato group. Examples of the group that reacts with the isocyanato group include compounds having a total of one hydroxyl group, amino group, imino group, mercapto group and the like. Specific examples thereof include monoamines such as n-butylamine and di-n-butylamine; ethanol. , Monohydric alcohols such as isopropanol and butanol, and the like.
(E) A plurality of types of terminal terminators may be used in combination.

<Characteristics of polyurethane resin>
The weight average molecular weight of the polyurethane resin in the aqueous polyurethane resin dispersion is usually about 25,000 to 1,000,000. It is preferably 50,000 to 5,000,000, more preferably 100,000 to 1,000,000. The weight average molecular weight is measured by gel permeation chromatography (GPC), and a converted value obtained from a calibration curve of standard polystyrene prepared in advance can be used. By setting the weight average molecular weight to 25,000 or more, a good film tends to be obtained by drying the aqueous polyurethane resin dispersion. By setting the weight average molecular weight to 1,000,000 or less, the drying property of the aqueous polyurethane resin dispersion tends to be higher.

<Polyurethane resin composition>
The content of the ring structure derived from polyisocyanate with respect to the solid content of the polyurethane resin in the aqueous polyurethane resin dispersion is preferably 5 to 15% by mass, more preferably 6 to 14% by mass, and particularly preferably 7 to 13%. It is mass%. Within this range, an aqueous polyurethane resin dispersion having excellent smoothness and tensile elongation when formed into a coating film can be obtained.
The mass ratio (b1) / (b2) of the (b1) polyether polyol to the (b2) polycarbonate polyol is preferably 99/1 to 50/50, more preferably 95/5 to 55/45. Particularly preferably, it is 90/10 to 60/40. Within this range, an aqueous polyurethane resin dispersion having excellent smoothness and tensile elongation when formed into a coating film can be obtained.
The content of the alicyclic structure derived from the polycarbonate polyol is preferably 1 to 20% by mass, more preferably 1 to 15% by mass, and particularly preferably 1 to 15% by mass, based on the solid content of the polyurethane resin in the aqueous polyurethane resin dispersion. It is 1 to 10% by mass.
Within this range, an aqueous polyurethane resin dispersion having excellent smoothness and tensile elongation when formed into a coating film can be obtained.

The total content of the urethane bond and the urea bond with respect to the polyurethane resin solid content in the aqueous polyurethane resin dispersion is preferably 7 to 18% by mass, more preferably 8 to 15% by mass.
By setting the total content ratio of the urethane bond and the urea bond to 7% by mass or more, the stickiness of the coating film surface after the coating film is dried may be reduced. Further, by setting the total content ratio of the urethane bond and the urea bond to 18% by mass or less, the adhesion between the coating film formed from the aqueous polyurethane resin dispersion and the base material may be improved.
The total content of urethane bond and urea bond is the molecular weight of each of (a) polyisocyanate, (b) polyol, (c) acidic group-containing polyol compound and (B) chain extender, hydroxyl group in one molecule, and isocyanato. It can be controlled by the number of groups and amino groups and the ratio of each raw material used in the aqueous polyurethane resin dispersion based on the solid content.

From the viewpoint of adhesion between the coating film formed from the aqueous polyurethane resin dispersion of the present invention and the base material, the content ratio of the carbonate bond in the aqueous polyurethane resin dispersion is preferably 0.1% by mass based on the solid content. As mentioned above, it is 30% by mass or less, more preferably 0.5% by mass or more and 15% by mass or less, and particularly preferably 1% by mass or more and 10% by mass or less.

The acid value of the aqueous polyurethane resin dispersion with respect to the polyurethane resin solid content in the aqueous polyurethane resin dispersion is not particularly limited, but is preferably 10 to 40 mgKOH / g, more preferably 15 to 32 mgKOH / g, and particularly preferably. Is 15 to 25 mgKOH / g. When the acid value of the aqueous polyurethane resin dispersion is in the range of 10 to 40 mgKOH / g based on the solid content, the storage stability tends to be improved. The acid value can be measured according to the indicator titration method of JIS K 1557. In the measurement, the neutralizing agent used to neutralize the acidic group shall be removed before the measurement. For example, when organic amines are used as a neutralizing agent, an aqueous polyurethane resin dispersion is applied onto a glass plate and dried at a temperature of 60 ° C. under a reduced pressure of 20 mmHg for 24 hours to obtain a coating film of N. -It can be dissolved in methylpyrrolidone (NMP) and the acid value can be measured according to the indicator titration method of JIS K 1557.
The total content of the alicyclic structure and the aromatic ring structure in the aqueous polyurethane resin dispersion with respect to the polyurethane resin solid content in the aqueous polyurethane resin dispersion is preferably 1 to 40% by mass, more preferably 3 to 30% by mass. %, Especially preferably 5 to 25% by mass. By setting the content ratio of the alicyclic structure in the aqueous polyurethane resin dispersion within the above range, the smoothness of the obtained coating film can be improved and the adhesion between the coating film and the base material can be improved.

<Aqueous medium>
In the aqueous polyurethane resin dispersion, water is mentioned as a medium for dispersing the polyurethane resin. Examples of water include clean water, ion-exchanged water, distilled water, ultrapure water, etc., but they are easily available and are less affected by salts that cause particle instability. From the viewpoint, ion-exchanged water is preferable.
Further, the aqueous medium may contain an organic solvent (an organic solvent added at the time of dispersion, an organic solvent used at the time of synthesizing the polyurethane resin). Examples of the organic solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran, dioxane, dimethylformamide, dimethyl sulfoxide, β-alkoxypropionamide (KJCMPA (R) -100, KJCMBPA (R) -100 manufactured by KJ Chemicals), and di. Examples thereof include propylene glycol dimethyl ether, ethyl acetate, N-methylpyrrolidone and N-ethylpyrrolidone, but a non-pyrrolidone solvent containing no pyrrolidone solvent such as N-methylpyrrolidone and N-ethylpyrrolidone is preferable, and dipropylene glycol dimethyl ether is more preferable. preferable. The non-pyrrolidone solvent refers to a solvent that does not contain the pyrrolidone solvent.
By using an organic solvent, when the aqueous polyurethane resin dispersion is used as a coating film, it functions as a film-forming auxiliary, and a coating film having excellent smoothness and tensile elongation can be obtained. The non-pyrrolidone solvent is inferior in film-forming property as compared with the pyrrolidone-based solvent, but the aqueous polyurethane resin dispersion of the present invention can obtain a coating film having excellent smoothness and tensile elongation even when the non-pyrrolidone solvent is used. Can be done. Furthermore, since it does not contain pyrrolidones such as N-methylpyrrolidone and N-ethylpyrrolidone, the burden on the environment can be reduced.

<Composition of aqueous polyurethane resin dispersion>
The content of the polyurethane resin in the aqueous polyurethane resin dispersion is preferably 5 to 60% by mass, more preferably 15 to 50% by mass.
Further, in the aqueous polyurethane resin dispersion of the present invention, if necessary, a thickener, a photosensitizer, a curing catalyst, an ultraviolet absorber, a light stabilizer, a defoaming agent, a plasticizer, a surface conditioner, and a sedimentation agent. Additives such as inhibitors can also be added. Two or more kinds of the additives may be used in combination. Further, as the additive, a commonly used additive can be used.

<Characteristics of polyurethane resin>
The aqueous polyurethane resin dispersion is applied to a smooth base material so that the film thickness after curing is 100 μm, dried, and then the cured coating film is subjected to a No. 5 dumbbell-like test by a method conforming to JIS K 7311. The tensile elongation measured using the piece is 600 to 2000%, preferably 750 to 1800%, and more preferably 900 to 1600%.
By setting the tensile elongation within this range, it is possible to obtain a coating film having excellent followability and adhesion to the substrate and having more excellent smoothness.

<Manufacturing method of aqueous polyurethane resin dispersion>
The method for producing the polyurethane resin dispersion is not particularly limited as long as it is a method in which the polyurethane resin is dispersed in an aqueous medium to obtain a polyurethane resin dispersion. Examples of the method for producing the polyurethane resin dispersion include a one-shot method in which all the raw materials are reacted at once, a prepolymer method in which an isocyanate-terminated polyurethane prepolymer is produced, and then a chain extender is reacted. Hereinafter, an example of a method for producing a polyurethane resin emulsion by the prepolymer method will be described.
The method for producing the polyurethane resin dispersion by the prepolymer method is, for example,
Steps (α) of reacting (a) a polyisocyanate, (b1) a polyether polyol, (b2) a polycarbonate polyol, and (c) an acidic group-containing polyol to obtain (A) a polyurethane prepolymer.
Step of dispersing polyurethane prepolymer in aqueous medium (β),
Step of neutralizing the acidic group of the polyurethane prepolymer with (c') neutralizer (γ),
Step of reacting polyurethane prepolymer with (d) chain extender (δ)
including. Here, the step (α) may further include a step of adding (e) a terminal terminator to the obtained (A) polyurethane prepolymer.

<Process (α)>
In step (α), when (a) polyisocyanate, (b1) polyether polyol, (b2) polycarbonate polyol, and (c) acidic group-containing polyol are reacted to obtain (A) polyurethane prepolymer. May react (a), (b1), (b2) and (c) in no particular order, or may react at the same time.
The step (α) may be carried out in an inert gas atmosphere or in an atmospheric atmosphere.
In the step (α), the reaction temperature at the time of reacting (a) polyisocyanate, (b1) polyether polyol, (b2) polycarbonate polyol, and (c) acidic group-containing polyol is not particularly limited. However, 40 to 150 ° C. is preferable, and 60 to 120 ° C. is particularly preferable. By setting the reaction temperature to 40 ° C. or higher, the raw material can be sufficiently dissolved or the raw material can obtain sufficient fluidity, the viscosity of the polyurethane prepolymer can be lowered, and sufficient stirring can be performed, and the reaction temperature can be set to 150. By setting the temperature to ℃ or lower, the reaction can proceed without causing problems such as side reactions.

A catalyst can also be used in step (α) to improve reactivity. The catalyst is not particularly limited, but for example, a tin catalyst (trimethyltin laurylate, dibutyltin dilaurylate, etc.), a lead catalyst (lead octylate, etc.), a titanium catalyst (titanium tetrabutoxide, etc.), etc. Examples thereof include metal salts, organic metal derivatives, amine-based catalysts (triethylamine, N-ethylmorpholin, triethylenediamine, etc.), and diazabicycloundecene-based catalysts. Of these, dibutyltin dilaurylate and titanium tetrabutoxide are preferable from the viewpoint of reactivity.

In step (α), the reaction of (a) polyisocyanate, (b1) polyether polyol, (b2) polycarbonate polyol, and (c) acidic group-containing polyol is carried out by adding an organic solvent even without a solvent. May be good. When the reaction is carried out without a solvent, a mixture of (a) polyisocyanate, (b1) polyether polyol, (b2) polycarbonate polyol, and (c) acidic group-containing polyol is obtained from the viewpoint of agitation. It is preferably liquid. When an organic solvent is added and reacted, examples of the organic solvent used include the above-mentioned organic solvent in the aqueous medium of the polyurethane resin emulsion. Acetone, methyl ethyl ketone, and ethyl acetate are preferably used because the polyurethane prepolymer can be dispersed in water, subjected to a chain extension reaction, and then removed by heating or reduced pressure. Further, N-methylpyrrolidone, N-ethylpyrrolidone, β-alkoxypropionamide, and dipropylene glycol dimethyl ether are preferable because they act as a film-forming auxiliary when preparing a coating film from the obtained polyurethane resin emulsion. Dimethyl ether is particularly preferred.

In the step (α), the ratio of the (e) terminal terminator can be appropriately determined according to the desired molecular weight of the polyurethane prepolymer and the like.
Further, the total number of hydroxyl group equivalents of (b1) polyether polyol, (b2) polycarbonate polyol, and (c) acidic group-containing polyol is preferably 120 to 1,000. When the number of hydroxyl group equivalents is within this range, the drying property and the thickening property are likely to increase, the aqueous resin dispersion containing the obtained polyurethane resin is easily produced, and a coating film having excellent hardness is easily obtained. .. From the viewpoint of storage stability and drying property of the obtained aqueous polyurethane resin dispersion and hardness of the coating film obtained by coating, the number of hydroxyl group equivalents is preferably 200 to 1,000, more preferably 400 to 800, and particularly preferably. Is 600-700.

The hydroxyl group equivalent number can be calculated by the following formulas (1) and (2).
Equivalent number of hydroxyl groups 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 polyol = M / total number of moles of polyol ... (2)
In the case of a polyurethane resin, in the formula (2), M is [[the number of hydroxyl groups of the polycarbonate polyol compound x the number of moles of the polycarbonate polyol compound] + [the number of hydroxyl groups of the acidic group-containing polyol x the number of moles of the acidic group-containing polyol]. + [Number of hydroxyl group equivalents of polyether polyol compound x number of moles of polyether polyol compound]] is shown.

In step (α), the amount of the organic solvent used is based on the total amount of (a) polyisocyanate, (b1) polyether polyol, (b2) polycarbonate polyol, and (c) acidic group-containing polyol. It is preferably 0.1 to 2.0 times, more preferably 0.15 to 0.8 times.
The acid value (AV) of the polyurethane prepolymer is preferably 4 to 40 mgKOH / g, more preferably 6 to 32 mgKOH / g, and particularly preferably 8 to 29 mgKOH / g. By setting the acid value of the polyurethane prepolymer to 4 mgKOH / g or more, the dispersibility in an aqueous medium and the storage stability tend to be improved. Further, by setting the acid value of the polyurethane prepolymer to 40 mgKOH / g or less, the water resistance of the coating film of the obtained polyurethane resin tends to be increased, and the flexibility of the obtained film tends to be increased. In addition, there is a tendency that the drying property at the time of producing a coating film can be improved.

The "acid value of the polyurethane prepolymer" is the acid in the so-called solid content, excluding the solvent used in producing the polyurethane prepolymer and the neutralizing agent for dispersing the polyurethane prepolymer in the aqueous medium. Indicates the value. Specifically, the acid value of the polyurethane prepolymer can be derived by the following formula (3).
[Acid value of polyurethane prepolymer] = [((c) Number of mmol of acidic group-containing polyol) × ((c) Number of acidic groups in one molecule of acidic group-containing polyol)] × 56.11 / [(a)) Total mass of polyisocyanate, (b1) polyether polyol, (b2) polycarbonate polyol and (c) acidic group-containing polyol] ... (3)

<Process (β)>
In the step (β), the method of dispersing the polyurethane prepolymer in the aqueous medium is not particularly limited, and for example, a method of adding the polyurethane prepolymer to the aqueous medium stirred by a homomixer, a homogenizer, or the like. A method of adding an aqueous medium to the polyurethane prepolymer that has been stirred by a homomixer, a homogenizer, or the like can be appropriately adopted.

<Process (γ)>
In the step (γ), the amount of the (c') neutralizing agent used is preferably 0.5 to 1.7 times the total number of moles of the (c) acidic group-containing polyol, and more preferably 0.6. It is ~ 1.3, and particularly preferably 0.7 to 1.2. Within this range, the dispersibility becomes good. The number of moles of acidic groups in the polyurethane resin is basically the number of moles of the acidic group-containing polyol used to obtain the polyurethane resin multiplied by the number of acidic groups in one minute of the acidic group-containing polyol. is there. The number of moles of the neutralizing agent is the number of moles of the neutralizing agent added to the polyurethane resin emulsion.

<Process (δ)>
In step (δ), the reaction between the polyurethane prepolymer and the chain extender (d) may be carried out slowly under cooling, and if necessary, the reaction may be promoted under heating conditions of 60 ° C. or lower. May be good. 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. Since the chain extension can also be carried out with water, when the aqueous medium in the step (β) is water, the water as the dispersion medium also serves as the (d) chain extender.
In step (δ), the amount of the (d) chain extender used is preferably equivalent or less, more preferably 0.7 to 0, relative to the isocyanato group that is the starting point of chain extension in the obtained polyurethane prepolymer. It is .99 equivalents. By adding the chain extender in an amount equal to or less than the equivalent of the isocyanato group, the molecular weight of the chain-extended urethane polymer was not reduced, and the coating film obtained by applying the emulsion composition containing the obtained polyurethane resin emulsion was applied. There is a tendency for the strength to be increased.

Hereinafter, preferred embodiments of the process will be described.
Either step (β) or step (γ) may be performed first. That is, the polyurethane prepolymer obtained in step (α) may be dispersed in an aqueous medium and then a neutralizing agent may be added, or the polyurethane prepolymer obtained in step (α) may be added with a neutralizing agent and then water-based. It may be dispersed in a medium. A dispersion medium in which the neutralizing agent is dispersed in an aqueous medium is prepared in advance, and the polyurethane prepolymer obtained in the step (α) is put into the aqueous medium in the dispersion medium to perform the step (β) and the step (γ). It can be done at the same time.

Either the step (β) or the step (γ) may be performed first, or may be performed at the same time. Further, the step (β) and the step (δ) may be performed at the same time. That is, the chain extender may be added after the polyurethane prepolymer is dispersed in the aqueous medium, or may be added during the dispersion. Further, the step (γ) and the step (δ) may be performed at the same time. From the viewpoint of improving the dispersion stability, it is preferable to perform the step (δ) after the step (β). Further, the step (β), the step (γ), and the step (δ) may be performed at the same time.
The method for producing the polyurethane resin emulsion is preferably a production method for obtaining the polyurethane resin emulsion by the step (α); then the step (β) and (γ); then the step (δ).

<Paint composition, coating agent composition, ink composition and adhesive composition>
The present invention also relates to a coating composition, a coating agent composition, an ink composition and an adhesive composition containing the aqueous polyurethane resin dispersion.
In addition to the above-mentioned aqueous polyurethane resin dispersion, other resins may be added to the coating composition, the coating agent composition, the ink composition and the adhesive composition. Examples of other resins include polyester resin, acrylic resin, polyether resin, polycarbonate resin, polyurethane resin, epoxy resin, alkyd resin, polyolefin resin, vinyl chloride resin and the like. These may be used alone or in combination of two or more. Other resins preferably have one or more hydrophilic groups. Examples of the hydrophilic group include a hydroxyl group, a carboxy 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 resin, acrylic resin, and polyolefin resin.

The coating composition, the coating agent composition, the ink composition and the adhesive composition may contain a curing agent, whereby the coating film or the coating film obtained by using the coating agent composition may contain a curing agent. , The water resistance of the coating film and printed matter can be improved.
As the curing agent, for example, amino resin, polyisocyanate, blocked polyisocyanate, melamine resin, carbodiimide and the like can be used. A plurality of types of curing agents may be used in combination.

Coloring pigments, extender pigments, and brilliant pigments can be added to the coating composition, the coating agent composition, the ink composition, and the adhesive composition.
Examples of the coloring pigment include titanium oxide, zinc flower, carbon black, molybdenum red, Prussian blue, cobalt blue, azo pigment, phthalocyanine pigment, quinacridone pigment, isoindoline pigment, slene pigment, perylene pigment and the like. These may be used in combination of a plurality of types. 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 in combination of a plurality of types. In particular, it is preferable to use barium sulfate and / or talc as the extender pigment, and it is more preferable to use barium sulfate.
As the bright pigment, for example, aluminum, copper, zinc, brass, nickel, aluminum oxide, mica, aluminum oxide coated with titanium oxide or iron oxide, or mica coated with titanium oxide or iron oxide can be used. ..

The paint composition, coating agent composition, ink composition and adhesive composition may be provided with a thickener, a curing catalyst, an ultraviolet absorber, a light stabilizer, an antifoaming agent, a plasticizer, and a surface adjustment, if necessary. It can contain ordinary additives such as agents and anti-settling agents. These may be used in combination of a plurality of types.
The method for producing the coating composition, the coating agent composition, the ink composition and the adhesive composition is not particularly limited, but a known production method can be used. Generally, the coating composition and the coating agent composition are produced by mixing the above-mentioned aqueous polyurethane resin dispersion and the above-mentioned various additives, further adding an aqueous medium, and adjusting the viscosity according to the application method. Will be done.

Examples of the material to be coated of the coating composition, the material to be coated of the coating agent composition, or the material to be applied of the ink composition include metals, plastics, inorganic substances, wood, etc. it can.
An electrodeposition coating plate is an object to be coated by immersing the object to be coated in a water-soluble paint and applying a DC voltage using the object to be coated as a cathode (or anode) and the paint as an opposite electrode of the object to be coated. It is a laminated board in which a coating film is formed on an object. In electrodeposition coating, even an object to be coated with a complicated shape can be painted in detail and can be painted automatically and continuously, so that a large and complicated shape such as an automobile body can be painted. It is preferable as an undercoat coating method for an object to be coated, which has a high rust preventive property. Further, it is economical because the use efficiency of the paint is extremely high as compared with other painting methods, and it is preferable as an industrial painting method. For example, cationic electrodeposition coating is performed by immersing an object to be coated in a cationic electrodeposition coating material having a cationic property as a cathode and applying a voltage.
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 the method of applying the ink composition include an inkjet printing method, a flexo printing method, a gravure printing method, a reverse offset printing method, a sheet-fed screen printing method, and a rotary screen printing method.

It is preferable that the coating composition, the coating agent composition and the ink composition are applied to the material to be applied and then heat-cured to obtain a coating film and a coating.
Examples of the heating method include a heating method using the heat of reaction of the self, a heating method for actively heating the coating composition, the coating agent composition, the ink composition, and the material to be applied. Examples of the active heating include a method in which the coating composition, the coating agent composition, the ink composition and the material to be applied are placed in a hot air oven, an electric furnace, or an infrared induction heating furnace to heat them.
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 0.1 to 10 hours. By setting such a heating time, a polyurethane resin film having higher hardness can be obtained. Drying conditions for obtaining the polyurethane resin film include, for example, heating at 120 ° C. for 3 to 10 seconds.
In particular, in the present invention, it is possible to form a coating film having high adhesion to a substrate at a relatively low temperature of about 80 to 90 ° C.
The thickness of the coating film after curing is not particularly limited, but is preferably 1 to 100 μm, and more preferably 3 to 50 μm.

<Polyurethane resin film>
The present invention further relates to a polyurethane resin film obtained from the aqueous polyurethane resin dispersion.
A polyurethane resin film can also be obtained by using an aqueous polyurethane resin dispersion. A polyurethane resin film can be obtained by applying an aqueous polyurethane resin dispersion to a releasable base material, drying and curing it by means such as heating, and then peeling a cured product of the polyurethane resin from the releasable base material. ..

Examples of the heating method include a heating method using its own reaction heat and a heating method in which the reaction heat and active heating of the mold are used in combination. Examples of active heating of the mold include a method of heating the mold 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 such a heating time, a polyurethane resin film having higher hardness can be obtained. Drying conditions for obtaining the polyurethane resin film include, for example, heating at 120 ° C. for 3 to 10 seconds.

Hereinafter, the present invention will be described in more detail based on specific examples, but the present invention is not limited to the following examples, and the present invention is appropriately modified without changing the gist thereof. It is possible to do.

(Hydroxy group value)
The measurement was performed according to the B method of JIS K 1557.

(Alicyclic structure content derived from polycarbonate polyol (PCD))
The mass fraction of the alicyclic structure derived from the polycarbonate polyol calculated from the charging ratio of each raw material of the aqueous polyurethane resin dispersion is shown. The mass fraction is based on the solid content of the aqueous polyurethane resin dispersion. 0.3 g of an aqueous polyurethane resin dispersion was applied onto a glass substrate to a thickness of 0.2 mm, and the mass remaining after heating and drying at 140 ° C. for 4 hours was measured, and this was divided by the mass before drying to form a solid. The concentration was defined as a minute concentration. The mass fraction was calculated by using the product of the total mass of the aqueous polyurethane resin dispersion and the solid content concentration as the solid content mass.

(Tensile elongation of polyurethane resin film)
An aqueous polyurethane resin dispersion was applied onto a PET film so as to have a film thickness of 100 μm, dried at room temperature overnight to form a film, and then baked at 60 ° C. for 2 hours and then at 120 ° C. for 2 hours. .. Then, the film cured overnight was punched into a dumbbell type No. 5 type, and the measurement was performed by a method conforming to JIS K 7311. The measurement conditions were a measurement temperature of 23 ° C., a humidity of 50%, and a tensile speed of 100 mm / min.

(Smoothness)
A paint prepared by adding 0.5% by mass of a pigment (EMF BLUE 2R manufactured by Toyo Color) to an aqueous polyurethane resin dispersion is applied on a polyethylene terephthalate substrate with a thickness of 200 μm, and dried at 90 ° C. for 5 minutes. went. When the coated portion was smooth with no color unevenness, it was evaluated as "◯", and when there was color unevenness, it was evaluated as "x".

[Example 1]
A reactor equipped with a stirrer and a heater, polytetramethylene glycol (product name (PTMG2000) (manufactured by Mitsubishi Chemical Corporation), number average molecular weight 1951; hydroxyl value 57.5 mgKOH / g, 241 g) and polycarbonate diol (product name). ETERNAL COLL UM-90 (1/3) (registered trademark; manufactured by Ube Industries); number average molecular weight 899; hydroxyl value 124.8 mgKOH / g, 60.8 g) and 2,2-dimethylol propionic acid (20.4 g) And IPDI (polyisocyanate having a ring structure and 12 carbon atoms) (112 g) in dipropylene glycol dimethyl ether (87.0 g) in the presence of dibutyltin dilaurylate (0.3 g) and in a nitrogen atmosphere, 80. It was heated at ~ 90 ° C. for 4 hours. The NCO group content at the end of the urethanization reaction was 2.45% by mass. After the reaction mixture was brought to 80 ° C., triethylamine (16.2 g) was added, and the mixture was stirred for 30 minutes. Of the reaction mixture, 503 g was withdrawn and placed in water (862 g) with vigorous stirring, and then a 35 mass% 2- (2-aminoethylamino) ethanol aqueous solution (38.4 g) was added as a chain extender. An aqueous polyurethane resin dispersion was obtained.

[Example 2]
A reactor equipped with a stirrer and a heater, polytetramethylene glycol (product name (PTMG2000) (manufactured by Mitsubishi Chemical Corporation), number average molecular weight 1951; hydroxyl value 57.5 mgKOH / g, 201 g) and polycarbonate diol (product name). ETERNAL COLL UM-90 (1/3) (registered trademark; manufactured by Ube Industries); number average molecular weight 899; hydroxyl value 124.8 mgKOH / g, 91.3 g) and 2,2-dimethylol propionic acid (19.8 g) And IPDI (polyisocyanate having a ring structure and 12 carbon atoms) (116 g) in dipropylene glycol dimethyl ether (86.3 g) in the presence of dibutyltin dilaurylate (0.3 g) and in a nitrogen atmosphere, 80. It was heated at ~ 90 ° C. for 4 hours. The NCO group content at the end of the urethanization reaction was 2.58% by mass. After the reaction mixture was brought to 80 ° C., triethylamine (15.7 g) was added, and the mixture was stirred for 30 minutes. Of the reaction mixture, 498 g was withdrawn and placed in water (849 g) with vigorous stirring, and then a 35 mass% 2- (2-aminoethylamino) ethanol aqueous solution (38.6 g) was added as a chain extender. An aqueous polyurethane resin dispersion was obtained.

[Example 3]
A reactor equipped with a stirrer and a heater, polytetramethylene glycol (product name (PTMG2000) (manufactured by Mitsubishi Chemical Corporation), number average molecular weight 1951; hydroxyl value 57.5 mgKOH / g, 185 g) and polycarbonate diol (product name). ETERNACOLL UM-90 (1/3) (registered trademark; manufactured by Ube Industries, Ltd.); number average molecular weight 899; hydroxyl value 124.8 mgKOH / g, 46.2 g) and 2,2-dimethylol propionic acid (14.6 g) And hydrogenated XDI (polyisocyanate having a ring structure and 10 carbon atoms) (71.3 g) in dipropylene glycol dimethyl ether (100 g) in the presence of dibutyltin dilaurylate (0.3 g) in a nitrogen atmosphere. , 80-90 ° C. for 3 hours. The NCO group content at the end of the urethanization reaction was 2.12% by mass. The reaction mixture was brought to 80 ° C. Of the reaction mixture, 391 g was extracted and placed in a mixed solution of dimethylaminoethanol (10.0 g) and water (862 g) with vigorous stirring, and then 35% by mass of 2-methyl-1,5 was used as a chain extender. -Aqueous diaminopentano solution (30.0 g) was added to obtain an aqueous polyurethane resin dispersion.

[Example 4]
A reactor equipped with a stirrer and a heater, polytetramethylene glycol (product name (PTMG2000) (manufactured by Mitsubishi Chemical Corporation), number average molecular weight 1951; hydroxyl value 57.5 mgKOH / g, 152 g) and polycarbonate diol (product name). ETERNACOLL UM-90 (1/3) (registered trademark; manufactured by Ube Industries); number average molecular weight 899; hydroxyl value 124.8 mgKOH / g, 67.6 g) and 2,2-dimethylol propionic acid (17.0 g) And TMXDI (polyisocyanate having a ring structure and having 14 carbon atoms) (93.9 g) in dipropylene glycol dimethyl ether (101 g) in the presence of dibutyltin dilaurylate (0.3 g) and in a nitrogen atmosphere. It was heated at ~ 90 ° C. for 5 hours. The NCO group content at the end of the urethanization reaction was 1.91% by mass. The reaction mixture was brought to 80 ° C. Of the reaction mixture, 409 g was extracted and placed in a mixed solution of dimethylaminoethanol (11.5 g) and water (806 g) with vigorous stirring, and then 35% by mass of 2-methyl-1,5 was used as a chain extender. -Aqueous diaminopentano solution (27.5 g) was added to obtain an aqueous polyurethane resin dispersion.

[Example 5]
A reactor equipped with a stirrer and a heater, polytetramethylene glycol (product name (PTMG2000) (manufactured by Mitsubishi Chemical Corporation), number average molecular weight 1951; hydroxyl value 57.5 mgKOH / g, 179 g) and polycarbonate diol (product name). ETERNACOLL UM-90 (3/1) (registered trademark; manufactured by Ube Industries, Ltd.); number average molecular weight 869; hydroxyl value 129.1 mgKOH / g, 76.6 g) and 2,2-dimethylol propionic acid (19.4 g). And TMXDI (polyisocyanate having a ring structure and having 14 carbon atoms) (110 g) in dipropylene glycol dimethyl ether (111 g) in the presence of dibutyltin dilaurylate (0.3 g) and in a nitrogen atmosphere, 80 to 90. It was heated at ° C. for 5 hours. The NCO group content at the end of the urethanization reaction was 1.91% by mass. The reaction mixture was brought to 80 ° C. Of the reaction mixture, 451 g was extracted and placed in a mixed solution of dimethylaminoethanol (13.1 g) and water (916 g) with vigorous stirring, and then 35% by mass of 2-methyl-1,5 was used as a chain extender. -Aqueous diaminopentano solution (33.5 g) was added to obtain an aqueous polyurethane resin dispersion.

[Comparative Example 1]
A reactor equipped with a stirrer and a heater, polytetramethylene glycol (product name (PTMG2000) (manufactured by Mitsubishi Chemical Corporation), number average molecular weight 2030; hydroxyl value 55.3 mgKOH / g, 18.7 g) and polycarbonate diol (18.7 g). Product name ETERNAL COLL UC-100 (registered trademark; manufactured by Ube Kosan); number average molecular weight 1030; hydroxyl value 109 mgKOH / g, 160 g), 2,2-dimethylol propionic acid (22.1 g), and hydrogenated MDI (ring) (147 g) of polyisocyanate having 15 carbon atoms having a structure is heated in N-methylpyrrolidone (146 g) in the presence of dibutyltin dilaurylate (0.2 g) in a nitrogen atmosphere at 80 to 90 ° C. for 6 hours. did. The NCO group content at the end of the urethanization reaction was 3.71% by mass. After the reaction mixture was brought to 80 ° C., triethylamine (16.7 g) was added, and the mixture was stirred for 30 minutes. Of the reaction mixture, 330 g was withdrawn and placed in water (622 g) with vigorous stirring, and then a 35 mass% 2-methyl-1,5-diaminopentano aqueous solution (46.7 g) was added as a chain extender. An aqueous polyurethane resin dispersion was obtained.

[Comparative Example 2]
A reactor equipped with a stirrer and a heater, polytetramethylene glycol (product name (PTMG2000) (manufactured by Mitsubishi Chemical Corporation), number average molecular weight 1961; hydroxyl value 57.2 mgKOH / g, 85.1 g) and polycarbonate diol ( Product name ETERNAL COLL UH-200 (registered trademark; manufactured by Ube Kosan); number average molecular weight 2011; hydroxyl value 55.8 mgKOH / g, 125 g), 2,2-dimethylol propionic acid (14.8 g), and hydrogenated MDI (Polyisocyanate having a ring structure and 15 carbon atoms) (95.9 g) in N-ethylpyrrolidone (109 g) in the presence of dibutyltin dilaurylate (0.3 g) in a nitrogen atmosphere at 80 to 90 ° C. Was heated for 5 hours. The NCO group content at the end of the urethanization reaction was 2.75% by mass. After the reaction mixture was brought to 80 ° C., triethylamine (11.0 g) was added, and the mixture was stirred for 30 minutes. Of the reaction mixture, 415 g was withdrawn and placed in water (436 g) with vigorous stirring, and then 35% by mass 2-methyl-1,5-diaminopentano aqueous solution (42.8 g) was added as a chain extender. An aqueous polyurethane resin dispersion was obtained.

The abbreviations in Table 1 are as follows.
<(A) Polyisocyanate>
IPDI: Isophorone diisocyanate (made by Evonik)
H6XDI: Hydrogenated xylylene diisocyanate (manufactured by Mitsui Chemicals)
TMXDI: Tetramethylxylene diisocyanate (manufactured by Ornex)
H12-MDI: Hydrogenated MDI (made by Evonik)
<(B1) Polyether polyol>
PTMG2000: Polytetramethylene glycol (manufactured by Mitsubishi Chemical Corporation)
<(B2) Polycarbonate polyol>
UM-90 (1/3): Polycarbonate polyol (manufactured by Ube Industries, Ltd.) obtained from a mixture of 1,4-cyclohexanedimethanol and 1,6-hexanediol (molar ratio 1: 3).
UM-90 (3/1): Polycarbonate polyol (manufactured by Ube Industries, Ltd.) obtained from a mixture of 1,4-cyclohexanedimethanol and 1,6-hexanediol (3: 1 in molar ratio).
UC-100: Polycarbonate polyol obtained from 1,4-cyclohexanedimethanol (manufactured by Ube Industries, Ltd.)
UH-200: Polycarbonate polyol obtained from 1,6-hexanediol as a raw material (manufactured by Ube Industries, Ltd.)
<(C) Acid group-containing polyol>
DMPA: 2,2-dimethylolpropionic acid (manufactured by Perstop)
<Chain extender (B)>
AEEA: 2- (2-aminoethylamino) ethanol (manufactured by Nippon Emulsion)
MPMD: 2-methyl-1,5-diaminopentane (Tokyo Kasei Reagent)

From the comparison between Examples 1 to 5 and Comparative Examples 1 and 2, it can be seen that the aqueous polyurethane resin dispersion of the present invention is excellent in smoothness when formed into a coating film. Further, from the comparison between Examples 1 and 2 and Examples 3 to 5, it can be seen that when hydrogenated xylylene diisocyanate or tetramethylxylylene diisocyanate is used as the polyisocyanate, the tensile elongation is excellent.

The present invention relates to a novel aqueous polyurethane resin dispersion and a coating composition using the same. The aqueous polyurethane resin dispersion is useful as a main component of various coating agents.

Claims (11)

A polyurethane resin having (a) a structure derived from polyisocyanate, (b1) a structure derived from a polyether polyol, (b2) a structure derived from a polycarbonate polyol, and (c) a structure derived from an acidic group-containing polyol is used as an aqueous medium. It is a dispersed dispersion,
(A) An aqueous polyurethane resin dispersion in which the structure derived from polyisocyanate is a structure derived from polyisocyanate having a ring structure and having 8 to 14 carbon atoms. (A) The structure derived from polyisocyanate having 8 to 14 carbon atoms having a ring structure is a structure derived from isophorone diisocyanate, a structure derived from xylylene diisocyanate, a structure derived from hydrogenated xylylene diisocyanate, and a structure derived from tetramethylxylylene diisocyanate. The aqueous polyurethane resin dispersion according to claim 1, which comprises at least one selected from the group consisting of a structure derived from tetramethylcyclohexyldiisocyanate and tetramethylcyclohexyldiisocyanate. (B2) The structure derived from the polycarbonate polyol is a structure derived from the polycarbonate polyol obtained from the alicyclic structure and the polyol monomer having two or more primary hydroxyl groups, or the aliphatic polyol monomer and the fat having two or more primary hydroxyl groups. The aqueous polyurethane resin dispersion according to claim 1 or 2, which comprises a structure derived from a polycarbonate polyol obtained from a cyclic structure and a polyol monomer having two or more primary hydroxyl groups. The aqueous polyurethane resin dispersion according to claim 3, wherein the content of the alicyclic structure derived from the polycarbonate resin (b2) with respect to the solid content of the polyurethane resin is 1 to 20% by mass. The aqueous polyurethane resin dispersion according to any one of claims 1 to 4, further comprising an organic solvent and the organic solvent being a non-pyrrolidone solvent. The tension was measured using a No. 5 dumbbell-shaped test piece by applying a cured coating film to a smooth substrate so that the film thickness after curing was 100 μm, drying, and then curing the coating film in accordance with JIS K 7311. The aqueous polyurethane resin dispersion according to any one of claims 1 to 5, which has an elongation of 600 to 2000%. A coating composition containing the aqueous polyurethane resin dispersion according to any one of claims 1 to 6. A coating agent composition containing the aqueous polyurethane resin dispersion according to any one of claims 1 to 6. An ink composition containing the aqueous polyurethane resin dispersion according to any one of claims 1 to 6. An adhesive composition containing the aqueous polyurethane resin dispersion according to any one of claims 1 to 6. A polyurethane resin film obtained by curing a composition containing the aqueous polyurethane resin dispersion according to any one of claims 1 to 6.