JP4994116B2 - Waterborne urethane resin - Google Patents

Description

  The present invention relates to an aqueous urethane resin, and more particularly to an aqueous urethane resin used in various fields.

Aqueous urethane used by dispersing or dissolving in water instead of organic solvent urethane resin used by dissolving in organic solvent in order to reduce use of organic solvent from the viewpoint of reducing environmental burden and improving working environment Resins have been developed in various fields.
Such an aqueous urethane resin can be obtained by first preparing an isocyanate group-terminated prepolymer from a polyisocyanate and a hydrophilic polyol, and then subjecting the isocyanate group-terminated prepolymer to a chain extension reaction with diamine in water.

For example, a polyurethane prepolymer solution is prepared by reacting diisocyanate, polycarbonate diol, carboxylic acid diol and tertiary amine in a volatile polar solvent in the presence of a catalyst, and the polyurethane prepolymer solution is dispersed in water. Subsequently, a method for producing an aqueous polyurethane dispersion in which an aqueous polyurethane dispersion is obtained by extending a chain with diamine and removing a volatile polar solvent has been proposed (for example, see Patent Document 1).
JP 2005-41990 A

However, in the production of the aqueous polyurethane resin, as described above, the isocyanate group-terminated prepolymer is subjected to a chain extension reaction with diamine in water, so that the polyisocyanate used for the preparation of the isocyanate group-terminated prepolymer does not easily react with water. It is assumed that it has a low activity isocyanate group terminal.
Therefore, highly active aromatic and araliphatic polyisocyanates cannot be used, and usable polyisocyanates are limited to low activity, aliphatic and alicyclic polyisocyanates.

However, aliphatic and alicyclic polyisocyanates are more expensive than aromatic polyisocyanates, and there is a limit to reducing the production cost of aqueous polyurethane resins.
Moreover, if the aqueous polyurethane resin which utilized the characteristic of aromatic polyisocyanate or araliphatic polyisocyanate can be prepared, those use expansion | deployment can be expanded.
An object of the present invention is to provide an aqueous polyurethane resin in which an aromatic and / or araliphatic polyisocyanate is used.

（式中、Ｒ１およびＲ２は、同一または相異なって炭素数１〜４のアルキレン基を示す。Ｒ３は、炭素数６〜１３の脂肪族炭化水素基、脂環族炭化水素基または芳香脂肪族炭化水素基を示す。Ｒ４は、炭素数１〜４のアルキル基を示す。ｎは８〜５０の整数を示す。） In order to achieve the above object, the aqueous polyurethane resin of the present invention is obtained by reacting at least an aromatic and / or araliphatic polyisocyanate, a polyol, and a compound having both a hydrophilic group and an active hydrogen group. Compound obtained by reacting a cyclic carbonate-terminated prepolymer obtained by reacting an isocyanate group-terminated prepolymer with a cyclic carbonate having an active hydrogen group with a polyamine, and having both the hydrophilic group and the active hydrogen group Is a diol having a polyoxyethylene chain represented by the following general formula (1) .
General formula (1)

(In the formula, R1 and R2 are the same or different and each represents an alkylene group having 1 to 4 carbon atoms. R3 represents an aliphatic hydrocarbon group, alicyclic hydrocarbon group or araliphatic group having 6 to 13 carbon atoms. Represents a hydrocarbon group, R4 represents an alkyl group having 1 to 4 carbon atoms, and n represents an integer of 8 to 50.)

In the aqueous polyurethane resin of the present invention, the aromatic and / or araliphatic polyisocyanate is preferably at least one selected from diphenylmethane diisocyanate, tolylene diisocyanate and xylylene diisocyanate.
In the aqueous polyurethane resin of the present invention, it is preferable that the cyclic carbonate having an active hydrogen group is monohydroxyethylene carbonate.

In the aqueous polyurethane resin of the present invention, it is preferable that the polyamine is a diamine.

  According to the aqueous polyurethane resin composition of the present invention, since aromatic and / or araliphatic polyisocyanate is used, an aqueous polyurethane resin utilizing these characteristics can be provided. Moreover, when aromatic polyisocyanate is used, an aqueous polyurethane resin can be provided at low cost.

The aqueous urethane resin of the present invention can be obtained by reacting a cyclic carbonate-terminated prepolymer with a polyamine.
The cyclic carbonate-terminated prepolymer can be obtained by a reaction between an isocyanate group-terminated prepolymer and a cyclic carbonate having an active hydrogen group.
The isocyanate group-terminated prepolymer can be obtained by reaction of a polyisocyanate component and an active hydrogen component.

The polyisocyanate component is selected from one or more aromatic polyisocyanates and araliphatic polyisocyanates.
Aromatic polyisocyanates include, for example, 4,4'-, 2,4'- or 2,2'-diphenylmethane diisocyanate or mixtures thereof (MDI), 2,4- or 2,6-tolylene diisocyanate or mixtures thereof (TDI), 3,3′-dimethoxybiphenyl-4,4′-diisocyanate, 1,5-naphthalene diisocyanate (NDI), m- or p-phenylene diisocyanate or mixtures thereof, 4,4′-diphenyl diisocyanate, 4, Aromatic diisocyanates such as 4'-diphenyl ether diisocyanate can be mentioned.

Examples of the araliphatic polyisocyanate include 1,3- or 1,4-xylylene diisocyanate or a mixture thereof (XDI), 1,3- or 1,4-tetramethylxylylene diisocyanate or a mixture thereof (TMXDI), Examples thereof include araliphatic diisocyanates such as ω, ω′-diisocyanato-1,4-diethylbenzene.
The polyisocyanate component includes, for example, the above-mentioned aromatic and / or araliphatic polyisocyanate multimer (for example, dimer, trimer, etc.), for example, the above-described aromatic and / or aromatic fat. Modified biuret produced by reaction of an aromatic polyisocyanate or multimer with water, modified allophanate produced by reaction with alcohol or the following low molecular weight polyol, modified oxadiazine trione produced by reaction with carbon dioxide gas Or the modified polyol etc. which are produced | generated by reaction with the following low molecular weight polyol are contained.

  These aromatic and / or araliphatic polyisocyanates may be used alone or in combination of two or more, and preferably include diphenylmethane diisocyanate, tolylene diisocyanate and xylylene diisocyanate. If diphenylmethane diisocyanate and tolylene diisocyanate are used, an aqueous polyurethane resin can be provided at low cost. Moreover, if xylylene diisocyanate is used, the water-based polyurethane resin which utilized the characteristic can be provided.

The active hydrogen component includes a polyol and a compound having both a hydrophilic group and an active hydrogen group (hereinafter referred to as a hydrophilic group-containing active hydrogen compound).
The polyol is a compound having two or more hydroxyl groups, and examples thereof include a low molecular weight polyol and a high molecular weight polyol (hereinafter referred to as macropolyol).
The low molecular weight polyol is, for example, a compound having a number average molecular weight of 60 to 400, for example, ethylene glycol, propylene glycol, trimethylene glycol, 1,4-butylene glycol, 1,3-butylene glycol, 1,2-butylene. Glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2,2-dimethyl-1,3-propanediol, neopentyl glycol, 1,6-hexanediol, 2,2-diethyl- C2-22 alkanediols such as 1,3-propanediol, 3,3-dimethylolheptane, 2-ethyl-2-butyl-1,3-propanediol, 1,12-dodecanediol, 1,18-octadecanediol For example, 2-butene-1,4-diol, 2,6-dimethyl-1-o Aliphatic diols such as alkene diols such as ten-3,8-diol: Fats such as 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, hydrogenated bisphenol A or its C2-4 alkylene oxide adduct Cyclic diols: for example, aromatic diols such as resorcin, xylylene glycol, bishydroxyethoxybenzene, bishydroxyethylene terephthalate, bisphenol A, bisphenol S, bisphenol F, and C2-4 alkylene oxide adducts of these bisphenols: Low molecular weight diols such as ether diols such as diethylene glycol, triethylene glycol, dipropylene glycol; for example, glycerin, 2-methyl-2-hydroxymethyl-1,3-propa Diol, 2,4-dihydroxy-3-hydroxymethylpentane, 1,2,6-hexanetriol, trimethylolethane, trimethylolpropane, 2-methyl-2-hydroxymethyl-1,3-propanediol, 2,4 Low molecular weight triols such as dihydroxy-3- (hydroxymethyl) pentane, 2,2-bis (hydroxymethyl) -3-butanol and other aliphatic triols (8 to 24 carbon atoms); for example, tetramethylolmethane, penta And low molecular weight polyols having four or more hydroxyl groups such as erythritol, dipentaerythritol, D-sorbitol, xylitol, D-mannitol, D-mannitol, and the like.

Examples of the macropolyol include polyether polyol, polyester polyol, polycarbonate polyol, acrylic polyol, epoxy polyol, natural oil polyol, silicone polyol, fluorine polyol, and polyolefin polyol.
As the polyether polyol, polyalkylene oxide, for example, polyethylene glycol, polypropylene glycol, polyethylene polypropylene obtained by addition reaction of alkylene oxide such as ethylene oxide and / or propylene oxide with the above-described low molecular weight polyol as an initiator. And glycols (random or block copolymers). Examples thereof include polytetramethylene ether glycol obtained by ring-opening polymerization of tetrahydrofuran.

  Examples of the polyester polyol include one or more of the above-described low molecular weight polyols and, for example, oxalic acid, malonic acid, succinic acid, methyl succinic acid, glutaric acid, adipic acid, 1,1-dimethyl-1,3. -Dicarboxypropane, 3-methyl-3-ethylglutaric acid, azelaic acid, sebacic acid, other aliphatic dicarboxylic acids (11 to 13 carbon atoms), hydrogenated dimer acid, maleic acid, fumaric acid, itaconic acid, Orthophthalic acid, isophthalic acid, terephthalic acid, toluene dicarboxylic acid, dimer acid, carboxylic acid such as heptic acid, and acid anhydrides derived from these carboxylic acids such as oxalic anhydride, succinic anhydride, maleic anhydride Acid, phthalic anhydride, 2-alkyl anhydride (12 to 18 carbon atoms) succinic acid, tetrahydro anhydride Le acid, trimellitic anhydride, and further, an acid halide derived from such these carboxylic acids, such as oxalic acid dichloride, adipic acid dichloride, and polyester polyols obtained by the reaction of such sebacic acid dichloride. Also, for example, lactone-based polyesters such as polycaprolactone polyols and polyvalerolactone polyols obtained by ring-opening polymerization of lactones such as ε-caprolactone and γ-valerolactone using the above low molecular weight polyol as an initiator. A polyol etc. are mentioned.

Examples of the polycarbonate polyol include a polycarbonate polyol obtained by reacting phosgene, dialkyl carbonate, diallyl carbonate, alkylene carbonate, etc. in the presence or absence of a catalyst with the above-described low molecular weight polyol as an initiator. It is done.
Examples of the acrylic polyol include a copolymer obtained by copolymerizing a polymerizable monomer having one or more hydroxyl groups and another monomer copolymerizable therewith. Examples of the polymerizable monomer having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, 2,2-dihydroxymethylbutyl (meth) acrylate, and polyhydroxy. Examples thereof include alkyl maleates and polyhydroxyalkyl fumarate. Moreover, as another monomer copolymerizable with these, for example, (meth) acrylic acid, alkyl (meth) acrylate (1 to 12 carbon atoms), maleic acid, alkyl maleate, fumaric acid, fumaric acid Alkyl, itaconic acid, alkyl itaconate, styrene, α-methylstyrene, vinyl acetate, (meth) acrylonitrile, 3- (2-isocyanato-2-propyl) -α-methylstyrene, trimethylolpropane tri (meth) acrylate, Examples include pentaerythritol tetra (meth) acrylate. The acrylic polyol can be obtained by copolymerizing these monomers in the presence of an appropriate solvent and a polymerization initiator.

Examples of the epoxy polyol include an epoxy polyol obtained by reacting the above-described low molecular weight polyol with a polyfunctional halohydrin such as epichlorohydrin or β-methylepichlorohydrin.
Examples of the natural oil polyol include hydroxyl group-containing natural oils such as castor oil and coconut oil.

As the silicone polyol, for example, in the copolymerization of the acrylic polyol described above, a vinyl group-containing silicone compound such as γ-methacryloxypropyltrimethoxysilane is used as another copolymerizable monomer. Examples include coalesced and terminal alcohol-modified polydimethylsiloxane.
As the fluorine polyol, for example, in the copolymerization of the above-mentioned acrylic polyol, a copolymer containing a vinyl group-containing fluorine compound, for example, tetrafluoroethylene, chlorotrifluoroethylene, etc., as another copolymerizable monomer Etc.

Examples of the polyolefin polyol include polybutadiene polyol, partially saponified ethylene-vinyl acetate copolymer, and the like.
These macropolyols have a number average molecular weight of, for example, 300 to 10,000, preferably 500 to 5,000, and a hydroxyl group equivalent of, for example, 100 to 5,000, preferably 160 to 2,500.

These polyols may be used alone or in combination of two or more. Preferably, the low molecular weight polyol includes an aliphatic diol, and the macropolyol includes a polyether polyol, a polyester polyol, and a polycarbonate polyol.
Moreover, a polyol is mix | blended in the ratio of 5-95 weight part with respect to 100 weight part of active hydrogen components, Preferably, it is 10-95 weight part. Specifically, when a low molecular weight polyol is blended, the blending ratio is, for example, 5 to 50 parts by weight, preferably 10 to 40 parts by weight with respect to 100 parts by weight of the active hydrogen component. Moreover, when a macropolyol is mix | blended, the compounding ratio is 40-95 weight part with respect to 100 weight part of active hydrogen components, Preferably, it is 50-90 weight part. Furthermore, when both a low molecular weight polyol and a macro polyol are blended, the blending ratio of the low molecular weight polyol with respect to 100 parts by weight of the macro polyol is, for example, 0.5 to 30 parts by weight, preferably 1 to 25 parts by weight. It is.

  The hydrophilic group-containing active hydrogen compound is, for example, a compound having both an active hydrogen group and a hydrophilic group such as a nonionic group such as a polyoxyethylene group or an ionic group such as an anionic group or a cationic group. is there. The hydrophilic group-containing active hydrogen compound is, for example, a compound having one hydrophilic group and having two or more active hydrogen groups, preferably a compound having one hydrophilic group and having two active hydrogen groups More preferably, a compound having one hydrophilic group and two hydroxyl groups can be used.

In the hydrophilic group-containing active hydrogen compound, examples of the anionic group include betaine structure-containing groups such as a carboxyl group, a sulfonyl group, a phosphate group, and a sulfobetaine. Examples of the nonionic group include a polyoxyethylene glycol residue, a copolymer residue of ethylene oxide and propylene oxide, and the like.
More specifically, examples of the hydrophilic group-containing active hydrogen compound having a carboxyl group include 2,2-dimethylolacetic acid, 2,2-dimethylollactic acid, 2,2-dimethylolpropionic acid, and 2,2-dimethylol. Examples include dihydroxycarboxylic acids such as butanoic acid, 2,2-dimethylolbutyric acid and 2,2-dimethylolvaleric acid, and diaminocarboxylic acids such as lysine and arginine.

Examples of the hydrophilic group-containing active hydrogen compound having a sulfonyl group include N, N-bis (2-hydroxyethyl) -2-aminoethanesulfonic acid, 1,3-phenylenediamine-4,6-disulfonic acid, Examples include diaminobutanesulfonic acid, 3,6-diamino-2-toluenesulfonic acid, 2,4-diamino-5-toluenesulfonic acid, and the like.
Examples of the hydrophilic group-containing active hydrogen compound having a phosphate group include 2,3-dihydroxypropylphenyl phosphate.

Examples of the hydrophilic group-containing active hydrogen compound having a betaine structure-containing group include a sulfobetaine group-containing compound obtained by a reaction of a tertiary amine such as N-methyldiethanolamine and 1,3-propane sultone. .
In addition, examples of the hydrophilic group-containing active hydrogen compound include a modified alkylene oxide in which an alkylene oxide such as ethylene oxide or propylene oxide is added to the hydrophilic group-containing active hydrogen compound.

  Moreover, as a hydrophilic group containing active hydrogen compound which has a polyoxyethylene glycol residue, the polyoxyethylene side chain containing diol which contains two hydroxyl groups and has a polyoxyethylene group in a side chain is mentioned, for example. The polyoxyethylene side chain-containing diol is, for example, firstly capped at one end with polyoxyethylene glycol (alkoxyethylene glycol capped at one end with a C1-4 alkyl group) and diisocyanate (as described above). After the urethanization reaction at a ratio in which the isocyanate group of the diisocyanate becomes excessive with respect to the hydroxyl group of the polyoxyethylene glycol, the polyoxyethylene group-containing monoisocyanate is obtained by removing the unreacted diisocyanate if necessary, The resulting polyoxyethylene group-containing monoisocyanate and dialkanolamine (C1-4 dialkanolamine) can be obtained by a urea reaction.

Such polyoxyethylene side chain-containing diol is represented, for example, by the following general formula (1).
General formula (1)

(In the formula, R1 and R2 are the same or different and each represents an alkylene group having 1 to 4 carbon atoms. R3 represents an aliphatic hydrocarbon group, alicyclic hydrocarbon group or araliphatic group having 6 to 13 carbon atoms. Represents a hydrocarbon group, R4 represents an alkyl group having 1 to 4 carbon atoms, and n represents an integer of 8 to 50.)
In the above formula (1), R1 and R2 are an alkylene group of dialkanolamine, R3 is a diisocyanate residue, R4 is an alkoxy group of one-end-capped polyoxyethylene glycol, and n is a piece This is the degree of polymerization of end-capped polyoxyethylene glycol polyoxyethylene.

In the polyoxyethylene side chain-containing diol, the polyoxyethylene group is preferably contained in an amount of 50% by weight or more, more preferably 60 to 90% by weight, and the number average molecular weight of the polyoxyethylene group is preferably It is 600-6000, More preferably, it is 700-3000.
As these hydrophilic group-containing active hydrogen compounds , polyoxyethylene side chain-containing diols are used in the present invention.

Moreover, a hydrophilic group containing active hydrogen compound is mix | blended in the ratio of 5-35 weight part with respect to 100 weight part of active hydrogen components, Preferably, it is 10-30 weight part.
The hydrophilic group-containing active hydrogen compound is blended so that the acid value of the aqueous polyurethane resin is 5 to 45 mgKOH / g, preferably 10 to 40 mgKOH / g. If the acid value is smaller than the above range, water dispersibility and water solubility may be lowered. Moreover, when larger than said range, the viscosity of an aqueous dispersion or aqueous solution may become high, and the water resistance of water-based polyurethane resin may fall.

  The hydrophilic group-containing active hydrogen compound is blended so that the content (EO%) of the ethylene oxide chain of the aqueous polyurethane resin is, for example, 3 to 25% by weight, preferably 5 to 20% by weight. . When EO% is smaller than the above range, water dispersibility and water solubility may be lowered. Moreover, when larger than said range, the viscosity of an aqueous dispersion or aqueous solution may become high, and the water resistance of water-based polyurethane resin may fall.

  A known method may be used to react the polyisocyanate component (aromatic and / or araliphatic polyisocyanate) with the active hydrogen component (polyol and hydrophilic group-containing active hydrogen compound). For example, active hydrogen The polyisocyanate component has a ratio of the isocyanate group of the polyisocyanate component to the active hydrogen group (hydroxyl group) of the component (NCO / active hydrogen group) of 1 or more, preferably 1.1 to 2.5. And an active hydrogen component are mixed and reacted.

In this reaction, the reaction temperature is set to, for example, 40 to 100 ° C., preferably 50 to 80 ° C. under normal pressure and, if necessary, in a nitrogen atmosphere, and the reaction time is, for example, 1 to 24 hours, preferably Is set to 2-12 hours. In this reaction, if necessary, a reaction solvent can be used and a reaction catalyst can be added.
The reaction solvent is a low-boiling solvent that is inert to the isocyanate group and easy to remove, for example, esters such as ethyl acetate and butyl acetate, ketones such as acetone and methyl ethyl ketone, such as tetrahydrofuran, and the like Ethers such as nitriles such as acetonitrile. The amount of reaction solvent used is appropriately determined.

Examples of the reaction catalyst include known urethanization catalysts such as amine-based, tin-based, and lead-based catalysts. The amount of reaction solvent added is appropriately determined.
By this reaction, the polyisocyanate component and the active hydrogen component undergo a urethanation reaction to obtain an isocyanate group-terminated prepolymer having an isocyanate group at the molecular end. The isocyanate group-terminated prepolymer obtained has a free isocyanate group content (determined by an amine titration method) of, for example, 0.5 to 12%, preferably 1 to 10%.

Next, the isocyanate group-terminated prepolymer and the cyclic carbonate having an active hydrogen group are reacted to obtain a cyclic carbonate-terminated prepolymer.
The cyclic carbonate having an active hydrogen group includes a cyclic carbonate having one or more active hydrogen groups, preferably a cyclic carbonate having one or more hydroxyl groups, and more preferably a cyclic carbonate having one hydroxyl group. As the cyclic carbonate having one hydroxyl group, for example, a cyclic carbonate having 2 to 5 carbon atoms such as ethylene carbonate and propylene carbonate, wherein one hydrogen atom of those ethylene groups is substituted with one hydroxyl group. Is mentioned. Preferably, monohydroxyethylene carbonate (monohydroxy 5-membered ring carbonate) and monohydroxypropylene carbonate (monohydroxy 6-membered ring carbonate) are used. More preferably, monohydroxyethylene carbonate is mentioned. This monohydroxyethylene carbonate includes glycerol carbonate derived from glycerol and dimethyl carbonate. The cyclic carbonate having an active hydrogen group can be used alone or in combination of two or more.

  In order to react the isocyanate group-terminated prepolymer with the cyclic carbonate having an active hydrogen group, for example, the equivalent ratio of the isocyanate group of the isocyanate group-terminated prepolymer to the active hydrogen group (hydroxyl group) of the cyclic carbonate having an active hydrogen group ( NCO / active hydrogen group) is a ratio of 1 or less, preferably 0.99 to 0.9, and the isocyanate group-terminated prepolymer and the cyclic carbonate having an active hydrogen group are mixed and reacted.

In this reaction, the reaction temperature is set to, for example, 40 to 100 ° C., preferably 50 to 80 ° C. under normal pressure and, if necessary, in a nitrogen atmosphere, and the reaction time is, for example, 2 to 12 hours, preferably Is set to 3-10 hours. In this reaction, if necessary, a reaction solvent similar to the above may be used and a reaction catalyst similar to the above may be added.
Specifically, for example, a cyclic carbonate having an active hydrogen group is added to the reaction solution of the isocyanate group-terminated prepolymer obtained above until the isocyanate group is consumed.

By this reaction, the isocyanate group-terminated prepolymer and the cyclic carbonate having an active hydrogen group undergo a urethanation reaction to obtain a cyclic carbonate-terminated prepolymer having a cyclic carbonate skeleton at the molecular end.
Further, in the obtained cyclic carbonate-terminated prepolymer, when the hydrophilic group of the hydrophilic group-containing active hydrogen compound is an anionic group, a neutralizing agent is added to the obtained cyclic carbonate-terminated prepolymer, Neutralizes anionic groups.

  Examples of the neutralizing agent include trimethylamine, triethylamine, tri-n-propylamine, tributylamine, triethanolamine, aminomethylpropanol, aminomethylpropanediol, aminoethylpropanediol, trihydroxymethylaminomethane, monoethanolamine, Examples include organic amines such as triisopropanolamine, inorganic alkali salts such as potassium hydroxide and sodium hydroxide, and ammonia. These neutralizing agents may be used singly or in combination of two or more, preferably organic amines. The addition amount of the neutralizing agent is, for example, 0.4 to 1.2 equivalents, preferably 0.6 to 1.0 equivalents per equivalent of anionic group.

By this neutralization, the anionic group of the cyclic carbonate-terminated prepolymer forms a salt.
Then, the cyclic carbonate-terminated prepolymer and the polyamine are reacted to obtain the aqueous urethane resin of the present invention.
Polyamines include, for example, aromatic diamines such as 4,4′-diphenylmethanediamine, for example, araliphatic diamines such as 1,3- or 1,4-xylylenediamine or mixtures thereof, such as 3-aminomethyl- 3,5,5-trimethylcyclohexylamine (common name: isophoronediamine), 4,4'-dicyclohexylmethanediamine, 2,5 (2,6) -bis (aminomethyl) bicyclo [2.2.1] heptane, Alicyclic diamines such as 1,3-bis (aminomethyl) cyclohexane and 1,4-cyclohexanediamine, such as ethylenediamine, 1,3-propanediamine, 1,4-butanediamine, 1,6-hexamethylenediamine, etc. Aliphatic diamines such as hydrazines (including hydrates) Amine: For example, diethylenetriamine, triethylenetetramine, aliphatic three or more amino groups such as tetraethylenepentamine polyamines such as amino alcohols such as N-(2-aminoethyl) ethanolamine.

Examples of polyamines include primary amino groups, alkoxysilyl compounds having primary amino groups and secondary amino groups, and polyoxyethylene group-containing polyamines. More specifically, as an alkoxysilyl compound having a primary amino group or a primary amino group and a secondary amino group, for example, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyl Examples include alkoxysilyl group-containing monoamines such as trimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, and N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane.

Examples of the polyoxyethylene group-containing polyamine include polyoxyalkylene ether diamines such as polyoxyethylene ether diamine. These polyamines may be used alone or in combination of two or more, and preferably include diamines, primary amino groups, or alkoxysilyl compounds having a primary amino group and a secondary amino group.
The cyclic carbonate-terminated prepolymer and the polyamine are dispersed or dissolved by reacting the cyclic carbonate-terminated prepolymer and the polyamine with water. As a result, the cyclic carbonate of the cyclic carbonate-terminated prepolymer is ring-opened, and urethanated with the amino group of the polyamine, whereby the cyclic carbonate-terminated prepolymer is chain-extended by the polyamine. The obtained aqueous polyurethane resin is prepared as an aqueous dispersion or aqueous solution dispersed or dissolved in water.

Specifically, first, the cyclic carbonate-terminated prepolymer is dispersed or dissolved. In order to disperse or dissolve in water, for example, the cyclic carbonate-terminated prepolymer is gradually added to water under stirring at a ratio of 20 to 500 parts by weight of water with respect to 100 parts by weight of the cyclic carbonate-terminated prepolymer.
Next, under stirring, the equivalent ratio of the carbonate skeleton of the cyclic carbonate-terminated prepolymer to the amino group of the polyamine (carbonate skeleton / amino group) is, for example, 0.8 to 0.8 in water in which the cyclic carbonate-terminated prepolymer is dispersed or dissolved. The polyamine is added so as to have a ratio of 1.2, preferably 0.9 to 1.1. After the addition, for example, the reaction is completed while stirring at 20 to 90 ° C., preferably 30 to 80 ° C., for 2 to 24 hours, preferably 5 to 20 hours.

In the above urethanization reaction, when a reaction solvent is used, after completion of the urethanization reaction, or after dispersion or dissolution, the reaction solvent is heated at an appropriate temperature, for example, under reduced pressure. To distill off.
The aqueous dispersion or aqueous solution of the aqueous polyurethane resin thus obtained is prepared such that its solid content is, for example, 10 to 60% by weight, preferably 20 to 50% by weight. Moreover, the weight average molecular weight of water-based polyurethane resin is several thousand-several million, for example as a standard polystyrene conversion value by GPC measurement, Preferably, it is several tens of thousands-several hundred thousand. Moreover, in the aqueous dispersion or aqueous solution of an aqueous polyurethane resin, the average particle diameter (measured by dynamic light scattering) of the aqueous polyurethane resin is, for example, 20 to 1000 nm, preferably 50 to 500 nm.

  In addition, the water-based polyurethane resin of the present invention, or an aqueous dispersion or aqueous solution thereof, is, for example, a plasticizer, an antifoaming agent, a leveling agent, an antifungal agent, and an antirust, as long as the excellent effects of the present invention are not impaired. Agent, matting agent, flame retardant, thixotropic agent, tackifier, thickener, lubricant, antistatic agent, surfactant, reaction retarder, antioxidant, ultraviolet absorber, hydrolysis inhibitor, weathering stability Additives such as an agent and an anti-tacking agent can be appropriately blended. The mixing ratio of various additives is appropriately selected depending on the purpose and application.

In the aqueous polyurethane resin of the present invention, the isocyanate group-terminated prepolymer is not dispersed or dissolved in water, but the cyclic carbonate-terminated prepolymer is dispersed or dissolved in water, and chain-extended by polyamine.
Therefore, highly active aromatic and araliphatic polyisocyanates can be used. As a result, it is possible to provide an aqueous polyurethane resin that takes advantage of these characteristics such as heat resistance and water resistance using an aromatic and / or araliphatic polyisocyanate while being an aqueous polyurethane resin. Moreover, if aromatic polyisocyanate is used, an aqueous polyurethane resin can be provided at low cost.

  Therefore, the aqueous polyurethane resin of the present invention is effectively used in industrial fields in which the aqueous polyurethane resin is used, for example, in the fields of paints, adhesives, primers, coating materials and the like.

Next, although this invention is demonstrated based on a reference example, an Example, and a comparative example, this invention is not limited by the following Example.
Reference example 1
In a four-necked flask equipped with a stirrer, a thermometer, a reflux tube, and a nitrogen introduction tube, 148.8 g of polyester polyol having a number average molecular weight of 2000 (Takelac U-5620, manufactured by Mitsui Chemicals Polyurethanes), 3.9 g of neopentyl glycol, 20.0 g of dimethylolpropionic acid and 126.4 g of acetone were charged. Next, 86.7 g of diphenylmethane diisocyanate (Mitsui Chemical Polyurethane Co., Ltd.) was added to the flask and reacted at 55 ° C. for 3 hours to obtain an isocyanate group-terminated prepolymer (free isocyanate group content 1.87%). .

Next, 21.3 g of glycerine carbonate was added to the flask and reacted until there was no absorption of isocyanate groups due to infrared absorption, and then 14.3 g of triethylamine was added to obtain a cyclic carbonate-terminated prepolymer.
Thereafter, 700 g of ion-exchanged water was stirred with a high-speed mixer, and 421.5 g of a cyclic carbonate-terminated prepolymer was gradually added thereto. Next, 4.9 g of ethylenediamine was added, the mixture was stirred at 40 ° C. for 8 hours, and acetone was distilled off to obtain an aqueous dispersion of an aqueous polyurethane resin A having a solid content of 30% by weight. The acid value of this aqueous polyurethane resin A was 27.8 mgKOH / g, and the average particle size was 80 nm.

Reference example 2
In a four-necked flask equipped with a stirrer, a thermometer, a reflux tube and a nitrogen introduction tube, 163.8 g of polytetramethylene ether glycol (PTG2000: manufactured by Hodogaya Chemical Co., Ltd.) having a number average molecular weight of 2000, 8.5 g of neopentyl glycol, di 16.5 g of methylolpropionic acid and 124.5 g of methyl ethyl ketone were charged. Subsequently, 66.4 g of tolylene diisocyanate (mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate: Cosmonate 80: manufactured by Mitsui Chemicals Polyurethanes) was added and reacted at 55 ° C. for 3 hours. An isocyanate group-terminated prepolymer was obtained (free isocyanate group content 2.09%).

Next, 23.5 g of glycerin carbonate was added to the flask and allowed to react until there was no isocyanate group absorption due to infrared absorption, and then 11.8 g of triethylamine was added to obtain a cyclic carbonate-terminated prepolymer.
Thereafter, 700 g of ion-exchanged water was stirred with a high-speed mixer, and 414.5 g of a cyclic carbonate-terminated prepolymer was gradually added thereto. Next, 4.7 g of ethylenediamine and 5.0 g of γ-aminopropyltriethoxysilane (KBE-903: manufactured by Shin-Etsu Chemical Co., Ltd.) were added and stirred at 40 ° C. for 8 hours, and further methyl ethyl ketone was distilled off. An aqueous dispersion of an aqueous polyurethane resin B having a solid content of 30% by weight was obtained. The acid value of this aqueous polyurethane resin B was 22.9 mgKOH / g, and the average particle size was 100 nm.

Reference example 3
In a four-necked flask equipped with a stirrer, a thermometer, a reflux tube, and a nitrogen introduction tube, 144.8 g of 1,6-hexane polycarbonate diol having a number average molecular weight of 2000 (UH-200: manufactured by Ube Industries), neopentyl glycol 15 0.1 g, dimethylolpropionic acid 13.6 g and methyl ethyl ketone 123.9 g were charged. Next, 79.8 g of 1,3-xylylene diisocyanate (Takenate 500: manufactured by Mitsui Chemicals Polyurethanes) was added to the flask and reacted at 70 ° C. for 5 hours to obtain an isocyanate group-terminated prepolymer (free). Isocyanate group content 2.34%).

Next, 26.1 g of glycerin carbonate was added to the flask and reacted until there was no absorption of isocyanate groups due to infrared absorption, and then 9.8 g of triethylamine was added to obtain a cyclic carbonate-terminated prepolymer.
Thereafter, 700 g of ion-exchanged water was stirred with a high-speed mixer, and 411.7 g of a cyclic carbonate-terminated prepolymer was gradually added thereto. Next, 11.6 g of hexamethylenediamine was added, and the mixture was stirred at 40 ° C. for 8 hours. Further, methyl ethyl ketone was distilled off to obtain an aqueous dispersion of an aqueous polyurethane resin C having a solid content of 30% by weight. The acid value of this aqueous polyurethane resin C was 18.9 mgKOH / g, and the average particle size was 120 nm.

Example 1
In a four-necked flask equipped with a stirrer, a thermometer, a reflux tube and a nitrogen introduction tube, 1000 g of methoxypolyethylene glycol having a number average molecular weight of 1000 (manufactured by Toho Chemical Co., Ltd.) and 1,6-hexamethylene diisocyanate (manufactured by Mitsui Chemical Polyurethane Co., Ltd.) 1682 g was charged and reacted at 90 ° C. for 9 hours under a nitrogen atmosphere. The obtained reaction solution was subjected to thin-film distillation to remove unreacted 1,6-hexamethylene diisocyanate, thereby obtaining a polyoxyethylene group-containing monoisocyanate.

  Next, 82.5 g of diethanolamine was charged into a four-necked flask equipped with a stirrer, a thermometer, a reflux tube, and a nitrogen introduction tube, and 917.5 g of the polyoxyethylene group-containing monoisocyanate was reacted while cooling with air in a nitrogen atmosphere. The solution was gradually added dropwise so that the temperature did not exceed 70 ° C. After completion of dropping, the mixture was stirred at 70 ° C. in a nitrogen atmosphere for about 1 hour to confirm that the isocyanate group had disappeared, and a polyoxyethylene side chain-containing diol was obtained.

  Next, in a four-necked flask equipped with a stirrer, a thermometer, a reflux tube and a nitrogen introduction tube, 151.4 g of 1,6-hexane polycarbonate diol having a number average molecular weight of 2000 (UH-200: manufactured by Ube Industries), neopentyl 15.8 g of glycol, 38.5 g of the polyoxyethylene side chain-containing diol and 126.0 g of methyl ethyl ketone were charged. Next, 62.8 g of tolylene diisocyanate (mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate: Cosmonate 80: manufactured by Mitsui Chemicals Polyurethanes) was added to the flask, and 5 at 70 ° C. It was made to react for time, and the isocyanate group terminal prepolymer was obtained (free isocyanate group content 2.19%).

Next, 25.5 g of glycerin carbonate was added to the flask and reacted until there was no absorption of isocyanate groups due to infrared absorption to obtain a cyclic carbonate-terminated prepolymer.
Thereafter, 700 g of ion-exchanged water was gradually added to the cyclic carbonate-terminated urethane prepolymer. Next, 5.9 g of ethylenediamine was added, and the mixture was stirred at 40 ° C. for 8 hours, and methyl ethyl ketone was distilled off to obtain an aqueous dispersion of an aqueous polyurethane resin D having a solid content of 30% by weight. The aqueous polyurethane resin D had a polyoxyethylene content of 9.8% by weight and an average particle size of 220 nm.

Comparative Example 1
In a four-necked flask equipped with a stirrer, a thermometer, a reflux tube and a nitrogen introduction tube, 160.3 g of polyester (Takelac U-5620: Mitsui Chemical Polyurethane Co., Ltd.) having a number average molecular weight of 2000, 4.2 g of neopentyl glycol, di 21.5 g of methylolpropionic acid and 126.3 g of acetone were charged. Next, 93.3 g of diphenylmethane diisocyanate (Mitsui Chemical Polyurethane Co., Ltd.) was added and reacted at 55 ° C. for 3 hours to obtain an isocyanate group-terminated prepolymer (free isocyanate group content 1.92%). Thereafter, 15.4 g of triethylamine was added to the isocyanate group-terminated prepolymer.

  Next, 700 g of ion-exchanged water was stirred with a high-speed mixer, and 420.7 g of an isocyanate group-terminated prepolymer was gradually added thereto. Then, foaming was caused by the reaction between the isocyanate group of diphenylmethane diisocyanate and water, and an aqueous dispersion of an aqueous urethane resin could not be obtained.

Claims (4)

An isocyanate group-terminated prepolymer obtained by reacting at least an aromatic and / or araliphatic polyisocyanate, a polyol, and a compound having both a hydrophilic group and an active hydrogen group; and a cyclic carbonate having an active hydrogen group A cyclic carbonate-terminated prepolymer obtained by the reaction of
Obtained by reacting with a polyamine,
An aqueous polyurethane resin, wherein the compound having both the hydrophilic group and the active hydrogen group is a diol having a polyoxyethylene chain represented by the following general formula (1).
General formula (1)

(In the formula, R1 and R2 are the same or different and each represents an alkylene group having 1 to 4 carbon atoms. R3 represents an aliphatic hydrocarbon group, alicyclic hydrocarbon group or araliphatic group having 6 to 13 carbon atoms. Represents a hydrocarbon group, R4 represents an alkyl group having 1 to 4 carbon atoms, and n represents an integer of 8 to 50.) The aqueous polyurethane resin according to claim 1, wherein the aromatic and / or araliphatic polyisocyanate is at least one selected from diphenylmethane diisocyanate, tolylene diisocyanate and xylylene diisocyanate.   The aqueous polyurethane resin according to claim 1 or 2, wherein the cyclic carbonate having an active hydrogen group is monohydroxyethylene carbonate.   The aqueous polyurethane resin according to claim 1, wherein the polyamine is a diamine.