JP2018177861A - Aqueous polyurethane resin dispersion for water vapor gas barrier coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous polyurethane resin dispersion for water vapor gas barrier coating that gives a coating film having high water vapor gas barrier properties.SOLUTION: In the polyurethane resin dispersion for water vapor gas barrier coating having a polyurethane resin dispersed in an aqueous medium, the polyurethane resin includes a constitutional unit derived from a polycarbonate polyol compound having an alicyclic structure in the main chain and a film formed of the aqueous polyurethane resin dispersion for water vapor gas barrier coating has a water vapor permeability of less than 4.0×10cmcm/cms Pa as measured under conditions of a film thickness of 0.08 mm, 273.15K and 1.013×10Pa in accordance with JIS Z0208.SELECTED DRAWING: None

Description

  The present invention relates to an aqueous polyurethane resin dispersion for water vapor gas barrier coating.

  Packaging materials typically used for packaging of food and beverages etc. have strength, resistance to cracking, retort resistance, heat resistance, etc. in order to protect the contents from various distribution, preservation such as cold storage, and treatment such as heat sterilization. Not only the function such as the nature but also a wide range of functions such as excellent transparency so as to be able to confirm the contents are required, and the use of plastic films and containers becomes mainstream for reasons such as transparency, lightness and economy. ing.

  The required performance of plastic films used for packaging of food, medicines, cosmetics etc. includes barrier properties against various gases such as water vapor and oxygen, transparency, retort resistance, impact resistance, flexibility, heat sealability etc. It can be mentioned.

  As a gas barrier material for forming a gas barrier layer, vinylidene chloride having high retort resistance and gas or water vapor barrier properties has been widely used, but there are problems such as generation of dioxin at the time of firing of disposal. In addition, when a polyvinyl alcohol resin or an ethylene-polyvinyl alcohol copolymer is used as a barrier coating material, the oxygen barrier property is high, but there is a problem that the water vapor barrier property is significantly reduced.

  It is known that an aqueous polyurethane resin dispersion composed of a polyisocyanate compound having a crosslinked cyclic hydrocarbon group exhibits high gas barrier properties (see Patent Documents 1 and 2). Further, it is known that an aqueous polyurethane resin dispersion having xylylene diisocyanate or hydrogenated xylylene diisocyanate as a constitutional unit exhibits gas barrier properties (see Patent Document 3). Furthermore, it is known that an aqueous polyurethane resin dispersion composed of a diol having a tricyclodecane skeleton exhibits water vapor barrier properties (see Patent Document 4).

Unexamined-Japanese-Patent No. 2006-143991 JP 2007-217642 A Patent No. 4524463 JP, 2016-20466, A

  However, the films obtained from the aqueous polyurethane resin dispersions described in Patent Documents 1 to 4 did not have high water vapor gas barrier properties.

  An object of the present invention is to provide an aqueous polyurethane resin dispersion for water vapor gas barrier coating, which gives a coating film having high water vapor gas barrier properties.

  The present inventors are an aqueous polyurethane resin for water vapor gas barrier coating which gives an aqueous polyurethane resin using a polycarbonate polyol having an alicyclic structure in the main chain and which can form a coating film having a specific water vapor permeability. The dispersion was found to have high water vapor gas barrier properties of the resulting coating.

The present invention relates to the following [1] to [9].
[1] An aqueous polyurethane resin dispersion for water vapor gas barrier coating, wherein a polyurethane resin is dispersed in an aqueous medium,
The polyurethane resin contains a structural unit derived from a polycarbonate polyol compound having an alicyclic structure in its main chain,
Water vapor permeability of the polyurethane resin film formed from the aqueous polyurethane resin dispersion for water vapor gas barrier coating was measured according to JIS Z0208 under the conditions of film thickness 0.08 mm, 273.15 K, 1.013 × 10 ⁵ Pa Is less than 4.0 × 10 ⁻¹⁰ cm ³ · cm / cm ² · s · Pa,
Waterborne polyurethane resin dispersion for water vapor gas barrier coating.
[2] The aqueous polyurethane resin dispersion for water vapor gas barrier coat according to [1], wherein the content of the alicyclic structure of the polycarbonate polyol having an alicyclic structure in the main chain is 1 to 50% by weight.
[3] The aqueous polyurethane resin dispersion for water vapor gas barrier coat of [1] or [2], wherein the polyurethane resin further contains a structural unit derived from a polyisocyanate compound having an alicyclic structure.
[4] The aqueous polyurethane resin dispersion for water vapor gas barrier coat of [3], wherein the polyisocyanate compound having an alicyclic structure is isophorone diisocyanate and / or dicyclohexylmethane-4,4'-diisocyanate.
[5] The aqueous polyurethane resin dispersion for water vapor gas barrier coat according to any one of [1] to [4], wherein the content of the alicyclic structure in the polyurethane resin is 5 to 50% by weight.
[6] A paint composition comprising the aqueous polyurethane resin dispersion for water vapor gas barrier coating according to any one of [1] to [5].
[7] A coating composition comprising the aqueous polyurethane resin dispersion for water vapor gas barrier coating according to any one of [1] to [5].
[8] A polyurethane resin film formed from the aqueous polyurethane resin dispersion for water vapor gas barrier coating according to any one of [1] to [5].
[9] A polyurethane resin film laminate in which a polyurethane resin film formed of the aqueous polyurethane resin dispersion for water vapor gas barrier coating according to any one of [1] to [5] is laminated on at least one of the substrates.

  According to the present invention, an aqueous polyurethane resin dispersion for water vapor gas barrier coating is provided which gives a coating film having high water vapor gas barrier properties.

  In the present specification, the term "step" is included in the term if the intended purpose of the step is achieved, even if it can not be distinguished clearly from the other steps, not only an independent step. . Moreover, the numerical range shown using "-" shows the range which includes the numerical value described before and after "-" as the minimum value and the maximum value, respectively. Furthermore, the content of each component in the composition means the total amount of the plurality of substances present in the composition unless a plurality of substances corresponding to each component are present in the composition.

<Water-based polyurethane resin dispersion for water vapor gas barrier coat>
In the aqueous polyurethane resin dispersion for water vapor gas barrier coating (hereinafter, also simply referred to as "aqueous polyurethane resin dispersion"), a polyurethane resin is dispersed in an aqueous medium, and the polyurethane resin has an alicyclic structure in the main chain The polyurethane resin film containing a constitutional unit derived from a polycarbonate polyol compound and formed from the aqueous polyurethane resin dispersion for water vapor gas barrier coating, has a film thickness of 0.08 mm, 273.15 K, 1.013 × 10 ⁵ Pa Under the conditions, the water vapor permeability measured in accordance with JIS Z0208 is less than 4.0 × 10 ⁻¹⁰ cm ³ · cm / cm ² · s · Pa.

<< Polyurethane resin >>
The polyurethane resin (a) contains a structural unit derived from a polycarbonate polyol compound having an alicyclic structure in the main chain. The polyurethane resin further comprises (b) a constituent unit derived from a polyisocyanate compound, (c) a constituent unit derived from an acidic group-containing polyol compound, (d) a constituent unit derived from an end terminator and (B) a chain extender And one or more structural units selected from the group consisting of structural units derived from The polyurethane resin is (a) a structural unit derived from a polycarbonate polyol compound having an alicyclic structure in the main chain, (b) a structural unit derived from a polyisocyanate compound, (c) a structural unit derived from an acidic group-containing polyol compound, It is preferred to have (B) a constituent unit derived from a chain extender and optionally (d) a constituent unit derived from an end terminator. Hereinafter, components forming each structural unit will be described.

<<< (a) polycarbonate polyol compound having an alicyclic structure in the main chain>>>
(A) A polycarbonate polyol compound having an alicyclic structure in its main chain (hereinafter, also referred to as “(a) polycarbonate polyol compound”) has two or more hydroxyl groups (excluding phenolic hydroxyl groups) in one molecule. If it does, it will not be restricted in particular. In addition, the (a) polycarbonate polyol compound contains, in the molecule, an ether bond or an ester bond which is equal to or less than the average number of carbonate bonds in one molecule, to the extent that the properties and functions of the present invention are not impaired It is also good. The polycarbonate polyol compound (a) may be used alone or in combination of two or more.

  (A) The polycarbonate polyol compound is, for example, a polyol monomer other than a polyol monomer having an alicyclic structure in the main chain and a polyol monomer optionally having an alicyclic structure in the main chain (hereinafter also referred to as "other polyol monomers") ) And carbonic ester compound and / or phosgene.

  Although it does not restrict | limit especially as a polyol monomer which has an alicyclic structure in a principal chain, For example, the polyol etc. which have a C5-C12 alicyclic group in a principal chain are mentioned. Specifically, 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanediol, 1,3-cyclopentanediol, 1,4-cycloheptanediol, 2,5-bis ( A diol having an alicyclic structure in the main chain, such as hydroxymethyl) -1,4-dioxane, 2,7-norbornanediol, tetrahydrofuran dimethanol, 1,4-bis (hydroxyethoxy) cyclohexane, isosorbide and the like can be mentioned. From the viewpoint of easy availability, the polyol monomer having an alicyclic structure in the main chain is preferably 1,4-cyclohexanedimethanol.

  Other polyol monomers include, for example, aliphatic polyol monomers, aromatic polyol monomers, polyester polyol monomers, and polyether polyol monomers.

  The aliphatic polyol monomer is not particularly limited. For example, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,5-hexanediol, 1,6-hexanediol, 1 Linear aliphatic diols such as 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol; 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propane Branched aliphatic diols such as diol, 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-1,9-nonanediol; trimethylolpropane, pentaerythritol, etc. And trifunctional or higher functional polyhydric alcohols.

  The aromatic polyol monomer is not particularly limited, and, for example, 1,4-benzenedimethanol, 1,3-benzenedimethanol, 1,2-benzenedimethanol, 4,4'-naphthalenedimethanol, 3,4 '-Naphthalene dimethanol etc. are mentioned.

  The polyester polyol monomer is not particularly limited, but, for example, a polyester polyol of hydroxycarboxylic acid and diol such as polyester polyol of 6-hydroxycaproic acid and hexanediol, and a dicarboxylic acid such as polyester polyol of adipic acid and hexanediol And polyester polyols and the like.

  The polyether polyol monomer is not particularly limited, and examples thereof include polyalkylene glycols such as polyethylene glycol, polypropylene glycol and polytetramethylene glycol, and the like.

  The carbonic acid ester compound is not particularly limited, but, for example, aliphatic carbonic acid ester compounds such as dimethyl carbonate and diethyl carbonate, aromatic carbonic acid ester compounds such as diphenyl carbonate and ditolyl carbonate, cyclic carbonic esters such as ethylene carbonate and propylene carbonate Compounds etc. may be mentioned. From the viewpoint of facilitating the production of the polycarbonate polyol, the carbonic acid ester compound is preferably an aliphatic carbonic acid ester or a cyclic carbonic acid ester, and dimethyl carbonate, diethyl carbonate and ethylene carbonate are particularly preferable.

  From the viewpoint of easy production and absence of by-products of terminal chlorinated compounds, (a) polycarbonate polyol compounds are a polyol monomer having an alicyclic structure in the main chain and optionally other polyol monomers, and a carbonate ester It is preferable to be obtained by reacting a compound. Further, from the viewpoint of the excellent dispersibility of the aqueous polyurethane resin dispersion to be obtained, the (a) polycarbonate polyol compound reacts with a polyol monomer having an alicyclic structure in the main chain, another polyol monomer, and a carbonic acid ester compound. It is more preferable to be obtained by From the viewpoint of suppressing an increase in viscosity when the resulting aqueous polyurethane resin dispersion is subjected to high-solid differentiation, the (a) polycarbonate polyol compound causes a polyol monomer having an alicyclic structure in the main chain to react with a carbonate compound. Is preferably obtained. Here, a combination of a diol having an alicyclic structure in the main chain and a linear aliphatic diol as a polyol monomer having an alicyclic structure in the main chain and optionally another polyol monomer, and an alicyclic ring in the main chain Preference is given to diols having the formula structure.

  From the above, the (a) polycarbonate polyol compound is preferably a polycarbonate diol, and a polycarbonate diol obtained by reacting 1,4-cyclohexanedimethanol and a carbonate ester, and / or 1,6-hexanediol Particularly preferred is a polycarbonate diol obtained by reacting a mixture of 1,4-cyclohexanedimethanol with a carbonate ester.

  As a specific method for producing a polycarbonate polyol compound from a polyol monomer having an alicyclic structure in its main chain, a carbonate compound, and optionally other polyol monomers, a carbonate and its carbonate in a reactor An excess number of moles of the polyol monomer is added to the number of moles, and the mixture is reacted under normal pressure at a temperature of 160 to 200 ° C. for 12 hours, and further reacted at 200 to 220 ° C. for several hours at a pressure of 6.7 kPa or less The method is mentioned. In the above reaction, it is preferable to make the reaction take out the by-produced alcohol out of the system. At that time, when the carbonate ester is azeotropically formed with the by-produced alcohol and thus comes out of the system, an excess amount of the carbonate ester may be added. In the above reaction, a catalyst such as titanium tetrabutoxide may be used.

<<<< (a) Properties of polycarbonate polyol compound >>>>
(A) The content of the alicyclic structure in the polycarbonate polyol compound (hereinafter, also referred to as “alicyclic structure content (polyol)”) is not particularly limited, but 1 to 50% by weight is preferable, and 10 to 50 % By weight is more preferable, 13 to 50% by weight is more preferable, and 20 to 50% by weight is particularly preferable. When the alicyclic structure content (polyol) is in this range, in addition to the fact that the water vapor gas barrier property of the coating film is further enhanced, an aqueous polyurethane resin dispersion having good abrasion resistance when formed into a coating film It is possible to suppress the increase in viscosity at the time of high solid differentiation.

  In the present specification, the alicyclic structure content (polyol) is defined as the weight ratio of the alicyclic group to the (a) polycarbonate polyol. For example, a cycloalkane residue such as a cyclohexane residue (in the case of 1,4-hexanedimethanol, a portion obtained by removing two hydrogen atoms from cyclohexane) or an unsaturated heterocyclic residue such as a tetrahydrofuran residue (tetrahydrofuran In the case of dimethanol, it refers to a value calculated based on the portion obtained by removing two hydrogen atoms from tetrahydrofuran.

  The number average molecular weight of the (a) polycarbonate polyol compound is preferably 400 to 8,000, and more preferably 400 to 4,000. When the number average molecular weight is in this range, a suitable viscosity and good handleability can be obtained, and furthermore, the reactivity with the (b) polyisocyanate compound will be sufficient, so a polyurethane resin, preferably mentioned later (A) The easiness of production of polyurethane prepolymer, improvement of efficiency and the like are improved. In addition, it is easy to ensure the performance of the obtained polyurethane resin as a soft segment, and it has an advantage that a tough coating can be obtained. Furthermore, when a coating film is formed using the aqueous polyurethane resin dispersion containing the obtained polyurethane resin, it is easy to suppress generation | occurrence | production of a crack.

  In the present specification, the number average molecular weight is a number average molecular weight calculated based on the hydroxyl value measured in accordance with JIS K 1577. Specifically, the hydroxyl value is measured, and it is calculated by (56.1 × 1,000 × number of valence) / hydroxyl value [mg KOH / g] by an end group determination method. In the formula, the valence is the number of hydroxyl groups in one molecule.

  The number of hydroxyl group equivalents of the (a) polycarbonate polyol compound is not particularly limited, and can be 50 to 950, and preferably 70 to 400. Moreover, it is preferable that the hydroxyl-equivalent number (total hydroxyl-equivalent number) of the sum total of (a) polycarbonate polyol compound and (c) acidic-group containing polyol is 100-1,000. If the total number of hydroxyl group equivalents is in this range, the drying property and the thickening property tend to increase, the production of the aqueous polyurethane resin dispersion containing the obtained polyurethane resin is easy, and a coating film excellent in hardness is obtained. It is easy to be Furthermore, from the viewpoint of the storage stability of the aqueous polyurethane resin dispersion obtained, the drying property and the hardness of the coating film obtained by coating, the total number of hydroxyl group equivalents is preferably 140 to 800, more preferably 180 to 600, particularly Preferably it is 200-400.

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

<<< (b) Polyisocyanate compound >>>
The polyisocyanate compound (b) is not particularly limited, and examples thereof include aromatic polyisocyanates, aliphatic polyisocyanates and alicyclic polyisocyanates. The polyisocyanate compound (b) may be used alone or in combination of two or more.

  The aromatic polyisocyanate is not particularly limited, and, for example, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate (TDI), 2,6-tolylene diisocyanate, 4,4 '-Diphenylmethane diisocyanate (MDI), 2,4-diphenylmethane diisocyanate, 4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4 4,4'-diisocyanatodiphenylmethane, 1,5-naphthylene diisocyanate, 4,4 ', 4' '-triphenylmethane triisocyanate, m-isocyanatophenylsulfonyl isocyanate, p-isocyanatophenylsulfonyl isocyanate, etc. To be

  The aliphatic polyisocyanate is not particularly limited, and, for example, ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 1,6,11-undecanetriisocyanate, 2,2,4-trimethylhexa Methylene diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethyl caproate, bis (2-isocyanatoethyl) fumarate, bis (2-isocyanatoethyl) carbonate, 2-isocyanatoethyl-2,6-diisocyanato Hexanoate etc. are mentioned.

  The alicyclic polyisocyanate is not particularly limited. For example, isophorone diisocyanate (IPDI), 4,4'-dicyclohexylmethane diisocyanate (H12MDI, hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated TDI) And bis (2-isocyanatoethyl) -4-cyclohexene-1,2-dicarboxylate, 2,5-norbornane diisocyanate, 2,6-norbornane diisocyanate and the like.

  (B) As a polyisocyanate compound, although what has two isocyanato groups per molecule can be used, in the range which (A) polyurethane prepolymer mentioned later does not gelatinize, like triphenylmethane triisocyanate It is also possible to use polyisocyanate compounds having three or more isocyanato groups per molecule.

  (B) The polyisocyanate compound may be modified to alphanate, nurate or the like.

  The polyisocyanate compound (b) is preferably an alicyclic polyisocyanate from the viewpoint of enhancing the durability of the coating film and efficiently increasing the content of the alicyclic structure in a polyurethane resin described later. In addition to the above-mentioned viewpoints, from the viewpoint that the reaction can be easily controlled, the (b) polyisocyanate compound is more preferably isophorone diisocyanate and / or 4,4′-dicyclohexylmethane diisocyanate, 4,4 Particularly preferred is' -dicyclohexylmethane diisocyanate. That is, the polyurethane resin preferably further contains a structural unit derived from a polyisocyanate compound having an alicyclic structure. In the polyurethane resin, the polyisocyanate compound having an alicyclic structure is more preferably isophorone diisocyanate (IPDI) and / or dicyclohexylmethane-4,4'-diisocyanate, and dicyclohexylmethane-4,4'- Particular preference is given to diisocyanates.

<<< (c) Acid group containing polyol>
The acidic group-containing polyol (c) is one containing two or more hydroxyl groups (excluding phenolic hydroxyl groups) and one or more acid groups in one molecule. As an acidic group, a carboxy group, a sulfonic acid group, a phosphoric acid group, phenolic hydroxyl group etc. are mentioned. The acidic group-containing polyol (c) may be used alone or in combination of two or more.

  (C) The acidic group-containing polyol is not particularly limited, and examples thereof include dimethylolalkanoic acids such as 2,2-dimethylol propionic acid and 2,2-dimethylol butanoic acid, N, N-bishydroxyethyl glycine, N, N-bishydroxyethyl alanine, 3,4-dihydroxybutanesulfonic acid, 3,6-dihydroxy-2-toluenesulfonic acid can be mentioned. From the viewpoint of easy availability, the (c) acidic group-containing polyol is preferably a compound containing a compound having two hydroxyl groups and one carboxy group in one molecule, and the carbon number containing two methylol groups 4 to 12 dimethyl roll alkanoic acid is more preferred, and 2,2-dimethylol propionic acid is particularly preferred.

  The number of hydroxyl group equivalents of the (c) acidic group-containing polyol is not particularly limited, and can be 20 to 300, preferably 50 to 200. Moreover, it is preferable that the hydroxyl equivalent number of (c) acidic group containing polyol is a range which satisfies the above-mentioned total hydroxyl group equivalent number.

<<<< (d) end terminator >>>
(D) Examples of the terminal stopper include compounds having one group which reacts with an isocyanato group, and examples thereof include monoamines such as n-butylamine, di-n-butylamine and diethanolamine; and monovalents such as ethanol, isopropanol and butanol. Alcohol and the like are preferred. (D) The end terminator may be used alone or in combination of two or more.

<<< chain extender (B) >>>
Examples of the chain extender (B) include compounds having two or more groups that react with an isocyanato group, and examples thereof include ethylene diamine, 1,4-tetramethylene diamine, 2-methyl-1,5-pentane diamine, 1,4 -Butanediamine, 1,6-hexamethylenediamine, 1,4-hexamethylenediamine, 3-aminomethyl-3,5,5-trimethylcyclohexylamine, 1,3-bis (aminomethyl) cyclohexane, xylylenediamine, Polyamine compounds such as piperazine, adipoyl hydrazide, hydrazine, 2,5-dimethylpiperazine, diethylene triamine, triethylene tetramine, etc. Diol compounds such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol; To polyethylene glycol Include water; polyalkylene glycols represented. Water as a chain extender can also function as an aqueous medium. The chain extender (B) may be used alone or in combination of two or more.

  The chain extender (B) is preferably a polyamine compound, more preferably a diamine compound, particularly preferably a primary diamine compound.

<<< Characteristics of polyurethane resin >>>
The content of the alicyclic structure in the polyurethane resin (hereinafter, also referred to as "alicyclic structure content (polyurethane)") is not particularly limited, but 5 to 50 wt% is preferable, and 10 to 50 wt% is more preferable. 20 to 50% by weight is more preferable, and 35 to 50% by weight is particularly preferable. By setting the alicyclic structure content (polyurethane) in this range, in addition to the fact that the water vapor gas barrier property of the coating film is further enhanced, it is possible to obtain an aqueous polyurethane resin dispersion having good abrasion resistance when formed into a coating film. It is possible to suppress the increase in viscosity at the time of high solid differentiation.

  Here, the alicyclic structure content (polyurethane) is a weight ratio of an alicyclic group in the polyurethane resin. For example, a cycloalkane residue such as a cyclohexane residue (in the case of 1,4-hexanedimethanol, a portion obtained by removing two hydrogen atoms from cyclohexane) or a dicyclohexylmethane residue (4,4′-dicyclohexylmethane diisocyanate) In the case of dicyclohexylmethane, the calculated value is based on 4 hydrogen atoms and 1 carbon atom removed) or isophorone residue (in the case of isophorone diisocyanate, 5 hydrogen atoms removed from cyclohexane) Say.

  The weight average molecular weight of the polyurethane resin is preferably 25,000 to 10,000,000, more preferably 50,000 to 5,000,000, and still more preferably 100,000 to 1,000,000. is there. When the weight average molecular weight is 25,000 or more, drying of the aqueous polyurethane resin dispersion tends to be able to obtain a good film. When the weight average molecular weight is 1,000,000 or less, the drying property of the aqueous polyurethane resin dispersion tends to be able to be further enhanced. In the present specification, the weight average molecular weight is measured by gel permeation chromatography (GPC), and a conversion value obtained from a calibration curve of standard polystyrene prepared in advance can be used.

<<< Composition of polyurethane resin >>>
(A) a structural unit derived from a polycarbonate polyol compound, (b) a structural unit derived from a polyisocyanate compound, (c) a structural unit derived from an acidic group-containing polyol compound, and (d) a structure derived from an end terminator in a polyurethane resin The content of the structural unit derived from the unit and the chain extender (B) is not particularly limited, but examples thereof include the amounts used of the respective components in the method for producing a polyurethane resin dispersion described later.

<< Water based medium >>
An aqueous medium includes water. Examples of water include, but are not limited to, fresh water, ion-exchanged water, distilled water, ultrapure water, etc., such as being easy to obtain and having little influence of salts causing particles to become unstable, etc. From the viewpoint of ion exchange water, it is preferable.

  The aqueous medium may contain an organic solvent. Examples of the organic solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran, dioxane, dimethylformamide, dimethyl sulfoxide, N-methyl pyrrolidone, N-ethyl pyrrolidone, β-alkoxypropionamide (KJ CMPA (R) -100 manufactured by KJ Chemicals KJCMBPA (R) -100), dipropylene glycol dimethyl ether, ethyl acetate and the like. N-methyl pyrrolidone, N-ethyl pyrrolidone, β-alkoxy propionamide, and dipropylene glycol dimethyl ether are preferable from the viewpoint of acting as a film forming aid when producing a coating film from the aqueous polyurethane resin dispersion. In addition to the effects of the film-forming aid described above, N-methyl pyrrolidone and N-ethyl pyrrolidone are more preferable from the viewpoint of being able to suppress the viscosity when raising the solid content of the aqueous polyurethane resin dispersion to a low level. .

<< Additives >>
The aqueous polyurethane resin dispersion is a thickener, a photosensitizer, a curing catalyst, an ultraviolet absorber, a light stabilizer, an antifoamer, a plasticizer, a surface conditioner, or the like, according to the required function, characteristics, use, etc. Additives such as anti-settling agents can be included. The additives may be used alone or in combination of two or more. The types of additives are known to those skilled in the art.

<< Composition >>
The content of the polyurethane resin in the aqueous polyurethane resin dispersion is preferably 5 to 60% by mass, and more preferably 15 to 50% by mass. The content of the aqueous medium and the additive in the aqueous polyurethane resin dispersion can be appropriately selected.

<Method of producing aqueous polyurethane resin dispersion>
According to the method for producing an aqueous polyurethane resin dispersion, (a) an aqueous polyurethane resin dispersion is obtained in which a polyurethane resin containing a structural unit derived from a polycarbonate polyol compound having an alicyclic structure in the main chain is dispersed in an aqueous medium It is not particularly limited as long as it is a method.

The method for producing the aqueous polyurethane resin dispersion is as follows:
Step (a) of reacting (a) a polycarbonate polyol compound having an alicyclic structure in the main chain and (c) an acidic group-containing polyol compound with (b) a polyisocyanate compound to obtain (A) a polyurethane prepolymer,
(A) the step of neutralizing the acid group of the polyurethane prepolymer (β),
(A) Step of dispersing polyurethane prepolymer in aqueous medium (γ), and (A) reaction of polyurethane prepolymer with (B) chain extender having reactivity with isocyanato group of polyurethane prepolymer (A) It is preferable to include the step (δ) of

  A polyurethane resin having a structural unit derived from a polycarbonate polyol compound having an alicyclic structure in the main chain (a), specifically, according to the method for producing an aqueous polyurethane resin dispersion including steps (α) to (δ): (A) a structural unit derived from a polycarbonate polyol compound having an alicyclic structure in the main chain, (b) a structural unit derived from a polyisocyanate compound, (c) a structural unit derived from an acidic group-containing polyol compound, (B) a chain An aqueous polyurethane resin dispersion is obtained, in which a polyurethane resin having a structural unit derived from an extender, and optionally (d) a structural unit derived from a terminal stopper, is dispersed in an aqueous medium. Below, the preferable aspect of the manufacturing method of aqueous polyurethane resin dispersion is demonstrated.

<< Step (α) >>
In the step (α), the (A) polyurethane prepolymer is obtained by reacting at least (a) a polycarbonate polyol compound, (b) a polyisocyanate compound, and (c) an acidic group-containing polyol compound.

  In the step (α), the (a) polycarbonate polyol compound and the (c) acidic group-containing polyol compound can be reacted with the (b) polyisocyanate compound in random order, and (a) the polycarbonate polyol compound and (c) acidic group The contained polyol compound may be simultaneously reacted with the (b) polyisocyanate compound. Step (α) may further include the step of adding (d) an end terminator to the obtained (A) polyurethane prepolymer.

  In the step (α), a catalyst can be used to improve the reactivity. The catalyst is not particularly limited, but, for example, metals such as tin-based catalyst (trimethyltin laurate, dibutyltin dilaurate etc.), lead-based catalyst (lead acid octylate etc.), titanium-based catalyst (titanium tetrabutoxide etc.) Examples thereof include salts, organometallic derivatives, amine catalysts (triethylamine, N-ethylmorpholine, triethylenediamine, etc.) and diazabicycloundecene catalysts. Among them, dibutyltin dilaurate and titanium tetrabutoxide are preferable from the viewpoint of reactivity.

  In the step (α), the reaction may be carried out without a solvent or in the presence of an organic solvent. When the reaction is carried out without solvent, it is preferable that the mixture of (a) polycarbonate polyol compound, (c) acidic group-containing polyol compound and (b) polyisocyanate compound is liquid from the viewpoint of stirring property. . The organic solvent is as described above in the aqueous medium, and is preferably acetone, methyl ethyl ketone or ethyl acetate from the viewpoint that it can be removed by heating or reducing pressure after dispersing the polyurethane prepolymer (A) in water and performing chain extension reaction.

  In the step (α), the reaction may be carried out under an inert gas atmosphere or under an air atmosphere.

  In the step (α), the reaction temperature is preferably, but not limited to, 40 to 150 ° C., more preferably 60 to 120 ° C. When the reaction temperature is 40 ° C. or more, the raw material is sufficiently dissolved or the raw material has sufficient fluidity, and the viscosity of the (A) polyurethane prepolymer can be lowered to perform sufficient stirring. By setting the temperature to 150 ° C. or less, the reaction can be allowed to proceed without causing problems such as occurrence of side reactions.

<<< Used amount >>>
In the step (α), the amount of the (a) polycarbonate polyol compound used is (a) polycarbonate polyol compound, (b) polyisocyanate compound, (c) acidic group-containing polyol compound, (B) chain extender, and optionally (D) The amount is preferably 20 to 80 parts by mass, more preferably 30 to 70 parts by mass, and particularly preferably 35 to 60 parts by mass with respect to 100 parts by mass of the total amount of the terminal stopper. When the amount of the polycarbonate polyol compound used is 30 parts by mass or more, there is a tendency that the drying property of the obtained aqueous polyurethane resin dispersion can be enhanced, and it is obtained by being 80 parts by mass or less The storage stability of the aqueous polyurethane resin dispersion tends to be further improved.

  In the step (α), the amount used of the (b) polyisocyanate compound is the isocyanate group of the (b) polyisocyanate compound relative to the number of moles of all hydroxyl groups of the (a) polycarbonate polyol compound and (c) acidic group-containing polyol compound. The ratio of the number of moles is preferably an amount of 1.05 to 2.5, more preferably an amount of 1.1 to 2.0, and particularly preferably an amount of 1.3 to 1.8.

  When the ratio of the number of moles of isocyanato groups of the polyisocyanate compound (b) is 1.05 or more, the amount of (A) polyurethane prepolymer having no isocyanato group at the molecular terminal decreases, and (B) a chain extender Fewer molecules do not react with it. This makes it easy to ensure the storage stability of the aqueous polyurethane resin dispersion. In addition, after drying the aqueous polyurethane resin dispersion, it becomes easy to form a film. In addition, when the ratio of the number of moles of isocyanato groups of the (b) polyisocyanate compound is 2.5 or less, the amount of unreacted (b) polyisocyanate compound remaining in the reaction system decreases, and (b) poly Since the isocyanate compound and (B) chain extender react efficiently, and it becomes difficult to cause unwanted molecular elongation due to the reaction with water, the preparation of the aqueous polyurethane resin dispersion can be properly performed, and the storage stability is more than that. improves. Furthermore, the drying properties of the resulting aqueous polyurethane resin dispersion tend to be high.

  In the step (α), the total amount of 100 parts by mass of (a) polycarbonate polyol compound, (b) polyisocyanate compound, (c) acidic group-containing polyol compound, (B) chain extender, and optionally (d) end terminator The amount of the (b) polyisocyanate compound relative to the above may be appropriately set according to the type or mass of the (a) polycarbonate polyol compound and the (c) acidic group-containing polyol compound within the range satisfying the above-mentioned molar ratio. Can.

  In the step (α), the amount used of (c) the acidic group-containing polyol compound is (a) a polycarbonate polyol compound, (b) a polyisocyanate compound, (c) an acidic group-containing polyol compound, (B) a chain extender, and In some cases, the amount is preferably 0.5 to 10 parts by mass, more preferably 4 to 9 parts by mass, based on 100 parts by mass of the total amount of the (d) end terminator. (C) When the amount of the acidic group-containing polyol compound used is 0.5 parts by mass or more, the dispersibility of the obtained aqueous polyurethane resin for water vapor barrier coat in an aqueous medium tends to be good, 10 mass By being less than 1 part, the drying property of the obtained aqueous polyurethane resin dispersion tends to be high. Moreover, the water resistance of the coating film obtained by apply | coating an aqueous polyurethane resin dispersion can be made high, and there exists a tendency which can also improve the softness | flexibility of the film obtained.

  In the step (α), the amount used of the (d) end terminator can be appropriately determined according to the molecular weight and the like of the polyurethane resin and the (A) polyurethane prepolymer.

  In the step (α), the amount of the organic solvent used is preferably 0 on a mass basis with respect to the total amount of (a) polycarbonate polyol compound, (c) acidic group-containing polyol compound and (b) polyisocyanate compound. 1 to 2.0 times, more preferably 0.15 to 0.8 times.

<<< (A) polyurethane prepolymer>>>
In the step (α), (a) a structural unit derived from a polycarbonate polyol compound having an alicyclic structure in the main chain, (b) a structural unit derived from a polyisocyanate compound, (c) a structure derived from an acidic group-containing polyol compound A polyurethane prepolymer (A) is obtained having units and structural units derived from (B) chain extender. Further, when the step (α) further comprises the step of adding (d) an end terminator to the obtained (A) polyurethane prepolymer, (A) the end of the polyurethane prepolymer is (d) end-terminated It has a structure derived from an agent.

  The acid value (AV) of the polyurethane prepolymer (A) obtained in step (α) is preferably 8 to 40 mg KOH / g, more preferably 20 to 35 mg KOH / g, and particularly preferably 24 to 30 mg KOH / g . When the acid value of the polyurethane prepolymer (A) is 8 mg KOH / g or more, the dispersibility in an aqueous medium and the storage stability tend to be able to be improved. (A) When the acid value of the polyurethane prepolymer is 40 mg KOH / g or less, the water resistance of the coating film of the obtained polyurethane resin tends to be enhanced, and the flexibility of the film obtained can be enhanced. There is also a tendency to be able to increase the drying properties at the time of preparation.

  In addition, the acid value of the polyurethane prepolymer (A) is preferably 12 to 28 mg KOH / g, more preferably 16 to 27 mg KOH, from the viewpoint that the viscosity when increasing the solid content of the aqueous polyurethane resin dispersion can be suppressed low. It is / g.

In the present specification, “(A) acid value (AV) of polyurethane prepolymer” refers to the organic solvent used in step (α) and the neutralizing agent used in step (β) described below, It shows the so-called acid value in solid content. Specifically, the acid value of the (A) polyurethane prepolymer can be derived by the following formula (3).
[Acid number of (A) polyurethane prepolymer] = [((m) number of millimoles of acid group-containing polyol compound) × ((c) number of acid group in one molecule of acid group-containing polyol compound)] × 56.11 / [Mass of total of (a) polycarbonate polyol compound, (c) acidic group-containing polyol compound and (b) polyisocyanate compound] (3)

<< Step (β) >>
In the step (β), the acidic groups of the (A) polyurethane prepolymer are specifically neutralized by the neutralizing agent. The acidic group of the (A) polyurethane prepolymer in the step (β) is as described above for the (c) acidic group-containing polyol.

  The neutralizing agent used in step (β) is not particularly limited as long as it is a known base, and examples thereof include trimethylamine, triethylamine, triisopropylamine, tributylamine, triethanolamine, N-methyldiethanolamine, and N-ethyl. Organic amines such as diethanolamine, N-phenyldiethanolamine, dimethylethanolamine, diethylethanolamine, N-methylmorpholine, and pyridine; inorganic alkali salts such as sodium hydroxide and potassium hydroxide; and ammonia. The neutralizing agent is preferably an organic amine, more preferably a tertiary amine. From the viewpoint of improving the dispersion stability, the neutralizing agent is more preferably triethylamine.

<< Step (γ) >>
In step (γ), the (A) polyurethane prepolymer is dispersed in an aqueous medium. In the step (γ), the method for dispersing the polyurethane prepolymer (A) in the aqueous medium is not particularly limited. For example, in the aqueous medium stirred by a homomixer, a homogenizer, etc. The method of adding a polymer, the method of adding an aqueous medium to the (A) polyurethane prepolymer stirred by a homomixer, a homogenizer, etc., etc. are mentioned.

<< Step (δ) >>
In step (δ), (A) the polyurethane prepolymer is chain extended by reaction with (B) a chain extender. In the step (δ), the amount of the chain extender (B) used is preferably not more than the equivalent with respect to the isocyanato group as the chain extension starting point in (A) polyurethane prepolymer, and more preferably an isocyanato group The ratio is 0.7 to 0.99 equivalent. By adding the chain extender (B) in an amount equal to or less than the equivalent weight of the isocyanato group, the resulting aqueous polyurethane resin dispersion is coated without lowering the molecular weight of the chain-extended urethane polymer (ie, polyurethane resin). There is a tendency that the strength of the obtained coating can be increased.

  Step (δ) may be carried out slowly (eg, at a temperature of 0 to 40 ° C.) under cooling, and in some cases, may be carried out to promote the reaction under heating conditions of 60 ° C. or less. The reaction time under cooling can be, for example, 0.5 to 24 hours, and the reaction time under heating conditions of 60 ° C. or less can be, for example, 0.1 to 6 hours.

<< Preferred embodiment >>
In the method for producing an aqueous polyurethane resin dispersion including the steps (α) to (δ), either the step (β) or the step (δ) may be performed first, or may be performed simultaneously. Furthermore, the step (β), the step (γ) and the step (δ) may be performed simultaneously. In addition, the step (δ) may be performed simultaneously with the step (γ) or may be performed after the step (γ). When the step (δ) is performed simultaneously with and / or after the step (γ), water as an aqueous medium also serves as a chain extender.

Therefore, as a more preferred example of the method for producing the aqueous polyurethane resin dispersion, the following method may be mentioned:
(A) reacting a polycarbonate polyol compound and (c) an acidic group-containing polyol compound with (b) a polyisocyanate compound to obtain (A) a polyurethane prepolymer (step (α '));
Then, the acid group of (A) polyurethane prepolymer is neutralized (step (β ′)),
Dispersing the solution obtained in step (β) in an aqueous medium (step (γ ′)),
Aqueous polyurethane by reacting (A) polyurethane prepolymer dispersed in a dispersion medium with (B) a chain extender having reactivity with isocyanato group of (A) polyurethane prepolymer (step (δ ′)) A resin dispersion is obtained.

<< Characteristics of polyurethane resin film formed from aqueous polyurethane resin dispersion >>
The polyurethane resin film is formed from an aqueous polyurethane resin dispersion. The polyurethane resin film formed from the aqueous polyurethane resin dispersion has a water vapor permeability measured according to JIS Z 0208 under the conditions of film thickness of 0.08 mm, 273.15 K, 1.013 × 10 ⁵ Pa (hereinafter simply referred to as “ Also referred to as “water vapor permeability” is less than 4.0 × 10 ⁻¹⁰ cm ³ · cm / cm ² · s · Pa. Since the water vapor permeability of the polyurethane resin film formed using the aqueous polyurethane resin dispersion is less than 4.0 × 10 ^-10 cm ³ · cm / cm ² · s · Pa, the aqueous polyurethane resin dispersion is used. The coating film has high water vapor gas barrier properties. The water vapor permeability of the polyurethane resin film is preferably less than 4.0 × 10 ⁻¹⁰ cm ³ · cm / cm ² · s · Pa, more preferably 5.0 × 10 ⁻¹¹ cm ³ · cm / cm It is less than ² · s · Pa. The water vapor permeability of the polyurethane resin film can be more than 0 cm ³ · cm / cm ² · s · Pa, 1.0 × 10 ^{-11 to} 1.0 × 10 ^-10 cm ³ · cm / cm More preferably, it is ² · s · Pa.

  Specifically, the polyurethane resin film applies an aqueous polyurethane resin dispersion to a releasable substrate, and is dried and cured by means such as heating, and subsequently the cured product of the polyurethane resin is peeled off from the releasable substrate It can be obtained by

  As a heating method, a heating method using its own reaction heat and a heating method using reaction heat and active heating of the mold in combination may be mentioned. The active heating of the mold may be carried out by placing the mold in a hot-air oven, an electric furnace, or an infrared induction heating furnace for heating. The heating temperature is preferably 40 to 200 ° C, more preferably 60 to 160 ° C. By heating at such temperature, drying can be performed more efficiently. The heating time is preferably 0.0001 to 20 hours, more preferably 1 to 10 hours. By setting it as such heating time, a polyurethane resin film with higher hardness can be obtained. As a drying condition for obtaining a polyurethane resin film, for example, a method of heating at 120 ° C. for 3 to 10 seconds is adopted.

  Therefore, the polyurethane resin film used for the measurement has a heating temperature of 40 to 200 ° C., a heating time of 0.0001 to 20 hours, and a drying condition of 120 ° C. for 3 to 10 seconds. It is preferable that it is a polyurethane resin film obtained by manufacturing conditions.

  In addition, although the thickness of the polyurethane resin film obtained is not limited to the thickness in the measurement conditions of the said water-vapor permeability, it is preferable that it is 1-100 micrometers, More preferably, it is 3-50 micrometers.

<Coating composition and coating composition>
The coating composition and the coating composition contain an aqueous polyurethane resin dispersion. The coating composition and the coating agent composition can contain other resins, a curing agent, a coloring pigment, an extender pigment, a bright pigment and conventional additives as components other than the aqueous polyurethane resin dispersion. The components other than the aqueous polyurethane resin dispersion may be used alone or in combination of two or more.

<< Other resin >>
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 from the viewpoint of dispersibility in water. 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 a polyester resin, an acrylic resin, and a polyolefin resin.

  The polyester resin can be produced by an esterification reaction or transesterification reaction of an acid component and an alcohol component. As the acid component, compounds which are usually used as an acid component in the production of polyester resins can be used. As an acid component, an aliphatic polybasic acid, an alicyclic polybasic acid, an aromatic polybasic acid etc. can be used, for example.

  The hydroxyl value of the polyester resin is preferably about 10 to 300 mg KOH / g, more preferably about 50 to 250 mg KOH / g, and still more preferably about 80 to 180 mg KOH / g. The acid value of the polyester resin is preferably about 1 to 200 mg KOH / g, more preferably about 15 to 100 mg KOH / g, and still more preferably about 25 to 60 mg KOH / g. 500-500,000 are preferable, as for the weight average molecular weight of a polyester resin, 1,000-300,000 are more preferable, and 1,500-200,000 are still more preferable.

  As an acrylic resin, a hydroxyl group-containing acrylic resin is preferable. The hydroxyl group-containing acrylic resin comprises, for example, a solution polymerization method in an organic solvent, a hydroxyl group-containing polymerizable unsaturated monomer and another polymerizable unsaturated monomer copolymerizable with the hydroxyl group-containing polymerizable unsaturated monomer, in water It can manufacture by copolymerizing by well-known methods, such as the emulsion polymerization method of this.

  The hydroxyl group-containing polymerizable unsaturated monomer is a compound having one or more hydroxyl group and one or more polymerizable unsaturated bond in one molecule. For example, (meth) acrylic acid such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate and the like, and having 2 to 8 carbon atoms Monoesters with dihydric alcohols; ε-caprolactone modified products of these monoesters; N-hydroxymethyl (meth) acrylamide; allyl alcohol; (meth) acrylate having a polyoxyethylene chain whose molecular terminal is a hydroxyl group Etc. can be mentioned.

  The hydroxyl group-containing acrylic resin preferably has an anionic functional group. As a hydroxyl group-containing acrylic resin having an anionic functional group, for example, a polymerizable unsaturated monomer having an anionic functional group such as a carboxylic acid group, a sulfonic acid group or a phosphoric acid group as one kind of a polymerizable unsaturated monomer It can be manufactured by using.

  The hydroxyl value of the hydroxyl group-containing acrylic resin is preferably 1 to 200 mg KOH / g, more preferably 2 to 100 mg KOH / g, and more preferably 3 to 60 mg KOH / g, from the viewpoint of storage stability of the composition and water resistance of the obtained coating film. Is more preferred. When the hydroxyl group-containing acrylic resin has an acid group such as a carboxyl group, the acid value of the hydroxyl group-containing acrylic resin is preferably 1 to 200 mg KOH / g, and 2 to 150 mg KOH, from the viewpoint of water resistance and the like of the coating film obtained. / G is more preferable, and 5 to 100 mg KOH / g is further preferable. 1,000-200,000 are preferable, as for the weight average molecular weight of a hydroxyl-containing acrylic resin, 2,000-100,000 are more preferable, More preferably, it exists in the range of 3,000-50,000.

  As a polyether resin, the polymer or copolymer which has an ether bond is mentioned, For example, polyoxyethylene-type polyether, polyoxypropylene-type polyether, polyoxybutylene-type polyether, bisphenol A or bisphenol F etc. Polyethers derived from aromatic polyhydroxy compounds and the like can be mentioned.

  As a polycarbonate resin, the polymer manufactured from the bisphenol compound is mentioned, For example, bisphenol A polycarbonate etc. are mentioned.

  As a polyurethane resin, resin which has a urethane bond obtained by reaction of various polyol components, such as an acryl, polyester, a polyether, a polycarbonate, etc. and polyisocyanate is mentioned, for example.

  As an epoxy resin, the resin etc. which are obtained by reaction of a bisphenol compound and epichlorohydrin are mentioned. Examples of bisphenols include bisphenol A and bisphenol F.

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

  As a polyolefin resin, a polyolefin resin obtained by polymerizing or copolymerizing an olefin monomer with another monomer appropriately according to a general polymerization method is dispersed in water using an emulsifying agent, or an olefin monomer is suitably used with another monomer And resins obtained by emulsion polymerization. Moreover, you may use what is called chlorinated polyolefin modified resin in which the said polyolefin resin was chlorinated depending on the case.

  Examples of olefin monomers include ethylene, propylene, 1-butene, 3-methyl-1-butene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-heptene, 1-hexene, 1- Α-olefins such as decene and 1-dodecene; conjugated dienes and non-conjugated dienes such as butadiene, ethylidene norbornene, dicyclopentadiene, 1,5-hexadiene, styrenes and the like can be mentioned. The olefin monomer may be used alone or in combination of two or more.

  Moreover, as another monomer copolymerizable with an olefin type monomer, vinyl acetate, vinyl alcohol, maleic acid, citraconic acid, itaconic acid, maleic anhydride, citraconic anhydride, itaconic anhydride etc. are mentioned, for example. The other monomers may be used alone or in combination of two or more.

<< hardening agent >>
Examples of the curing agent include amino resins, polyisocyanates, blocked polyisocyanates, melamine resins, carbodiimides, polyols and the like. When the coating composition and the coating composition contain a curing agent, the water resistance, etc. of the coating film, multilayer coating film, coating film or printed matter obtained using the coating composition or the coating composition can be improved. . The curing agent may be used alone or in combination of two or more.

  The amino resin includes, for example, partially or completely methylated amino resin obtained by the reaction of an amino component and an aldehyde component. Examples of the amino component include melamine, urea, benzoguanamine, acetoguanamine, steroguanamine, spiloganamine, dicyandiamide and the like. Examples of the aldehyde component include formaldehyde, paraformaldehyde, acetaldehyde, benzaldehyde and the like.

  Examples of the polyisocyanate include compounds having two or more isocyanato groups in one molecule, and examples thereof include hexamethylene diisocyanate and trimethylhexamethylene diisocyanate.

Examples of blocked polyisocyanates include those obtained by adding a blocking agent to the isocyanato group of the aforementioned polyisocyanate, and as the blocking agent,
Phenols, phenols such as cresol, aliphatic alcohols such as methanol and ethanol, active methylenes such as dimethyl malonate and acetylacetone, mercaptans such as butyl mercaptan and dodecyl mercaptan, acid amides such as acetanilide, acetic acid amide, ε -Lactams such as caprolactam and δ-valerolactam, imides such as succinimide and maleimide, oximes such as acetoaldoxime, acetone oxime and methyl ethyl ketoxime, amines such as diphenylaniline, aniline and ethyleneimine And other blocking agents.

  Examples of melamine resins include methylolmelamines such as dimethylolmelamine and trimethylolmelamine; alkyl ethers or condensates of these methylolmelamines; and condensates of alkylolates of methylolmelamine.

  The polyol includes, for example, polyrotaxane and compounds derived therefrom.

<< Colored pigment >>
Examples of color pigments include titanium oxide, zinc flower, carbon black, molybdenum red, Prussian blue, cobalt blue, azo pigments, phthalocyanine pigments, quinacridone pigments, isoindoline pigments, styrene pigments, perylene pigments, etc. Titanium and / or carbon black are preferred. The color pigments may be used alone or in combination of two or more.

<< constitution pigment >>
Examples of extender pigments include clay, kaolin, barium sulfate, barium carbonate, calcium carbonate, talc, silica and alumina white, with barium sulfate and / or talc being preferred, and barium sulfate is more preferred. The extender pigment may be used alone or in combination of two or more.

<< Glittering pigment >>
Examples of bright pigments include aluminum, copper, zinc, brass, nickel, aluminum oxide, mica, aluminum oxide coated with titanium oxide and iron oxide, and mica coated with titanium oxide and iron oxide. The bright pigment may be used alone or in combination of two or more.

<< Normal Additives >>
Typical additives include thickeners, curing catalysts, ultraviolet light absorbers, light stabilizers, antifoaming agents, plasticizers, surface conditioners, anti-settling agents and the like. It can select suitably according to the function, the characteristic, the use, etc. of a paint constituent and a coating agent constituent. The conventional additives may be used alone or in combination of two or more, and commercially available products may be used as they are.

<< Coating composition and method of producing coating composition >>
The method for producing the coating composition and the coating agent composition is not particularly limited, but any known production method can be employed. Preferably, the coating composition and the coating agent composition are produced by mixing the aqueous polyurethane resin dispersion and the various additives described above, adding an aqueous medium, and adjusting the viscosity according to the application method. .

<< Method of using paint composition and coating composition >>
The coating composition can be applied to the substrate to be coated, and the coating composition can be applied to the substrate to be coated. As a material of such a to-be-coated base material and a to-be-coated base material, a metal, a plastics, an inorganic substance, a wood etc. are mentioned, for example. The coating method of the coating composition or the coating method of the coating composition includes, for example, bell coating, spray coating, roll coating, shower coating, dip coating, inkjet printing method, flexographic printing method, gravure printing method, reverse offset printing method , Sheet-fed screen printing methods, rotary screen printing methods, and the like.

  The thickness of the coating film after curing of the coating composition and the coating agent composition is not particularly limited, but a thickness of 1 to 100 μm is preferable, and more preferably, a coating film having a thickness of 3 to 50 μm is formed. Is particularly preferred.

<Polyurethane resin film laminate>
In the polyurethane resin film laminate, a polyurethane resin film formed from an aqueous polyurethane resin dispersion is laminated on at least one of the substrates. The polyurethane resin film is as described above.

  As a base material of a polyurethane resin film layered product, the base material mentioned above as a material of a coated base material and a coated base material is mentioned, and a base material constituted by thermoplastic resin is preferred. Examples of the thermoplastic resin include polyolefin resins, polyester resins, polyamide resins, vinyl resins, acrylic resins, cellophane and the like. These resins can be used alone or in combination of two or more. The thickness of the substrate is not particularly limited, and can be set as appropriate.

  EXAMPLES The present invention will next be described by way of examples, which should not be construed as limiting the scope of the present invention.

Example 1
In a reaction vessel into which a stirrer, a reflux condenser and a thermometer are inserted, ETERNACOLL UM 90 (3/1) (manufactured by Ube Industries, Ltd .; number average molecular weight 916; hydroxyl value 123 mg KOH / g; content of alicyclic structure 39% by weight; Polycarbonate diol obtained by reacting a polyol mixture having a molar ratio of 1,4-cyclohexanedimethanol: 1,6-hexanediol = 3: 1 with a carbonate component, 1,500 g), 2, 2 -Dimethylol propionic acid (220 g) and dicyclohexylmethane-4,4'-diisocyanate (H12 MDI, 1,450 g) in N-methylpyrrolidone (NMP, 1,350 g) dibutyltin dilaurate (2.6 g) In the presence of nitrogen atmosphere at 80-90 ° C. for 6 hours. The NCO group content in the prepolymer at the end of the urethanization reaction was 3.97% by weight. The reaction mixture was cooled to 80 ° C., to which triethylamine (149 g) was added and mixed. The viscosity at this time was 2,000 cP. 4,360 g of the reaction mixture was withdrawn and added to water (6,900 g) under strong stirring. Next, a 35 wt% aqueous solution of 2-methyl-1,5-pentanediamine (MPMD aqueous solution, 626 g) was added to obtain an aqueous polyurethane resin dispersion.

(Example 2)
In a reactor equipped with a stirrer and a heater, ETERNACOLL® UM90 (3/1) (manufactured by Ube Industries, Ltd .; number average molecular weight 916; hydroxyl value 123 mg KOH / g; content of alicyclic structure 39% by weight; Polycarbonate diol obtained by reacting a polyol mixture having a molar ratio of 1,4-cyclohexanedimethanol: 1,6-hexanediol = 3: 1 with a carbonate ester, 175 g), Methylol propionic acid (26.0 g) and isophorone diisocyanate (IPDI, 142 g) in N-methylpyrrolidone (137 g) in the presence of dibutyltin dilaurate (0.3 g) at 80-90 ° C. under a nitrogen atmosphere. Heated for 6 hours. The reaction mixture was cooled to 80 ° C. and 404 g of it was added and mixed with triethylamine (19.6 g), and added to water (535 g) under strong stirring. Then, 35 wt% of 2-methyl-1,5-pentanediamine aqueous solution (60.9 g) was added to obtain an aqueous polyurethane resin dispersion.

(Example 3)
In a reaction vessel into which a stirrer, a reflux condenser and a thermometer are inserted, ETERNACOLL UM 90 (1/3) (manufactured by Ube Industries, Ltd .; number average molecular weight 916; hydroxyl value 123 mg KOH / g; content of alicyclic structure 13% by weight; Polycarbonate diol obtained by reacting a polyol mixture having a molar ratio of 1,4-cyclohexanedimethanol: 1,6-hexanediol = 1: 3 with a carbonate ester, 150 g), Methylol propionic acid (22.0 g) and dicyclohexylmethane-4,4'-diisocyanate (H12 MDI, 145 g) in N-methylpyrrolidone (135 g) in the presence of dibutyltin dilaurate (0.3 g) under nitrogen atmosphere And heated at 80-90.degree. C. for 6 hours. The reaction mixture was cooled to 80 ° C., to which triethylamine (14.9 g) was added and mixed. 436 g of the reaction mixture was withdrawn and added to water (690 g) under vigorous stirring. Then, 35 wt% of 2-methyl-1,5-pentanediamine aqueous solution (62.6 g) was added to obtain an aqueous polyurethane resin dispersion.

(Comparative example 1)
In a reaction apparatus equipped with a stirrer and a heater, ETERNACOLL (registered trademark) UH 200 (manufactured by Ube Industries, Ltd .; number average molecular weight 2,000; hydroxyl value 57 mg KOH / g; 1,6-hexanediol and carbonate ester are reacted The obtained polycarbonate diol, 101 g), 2,2-dimethylol propionic acid (11.8 g) and isophorone diisocyanate (IPDI, 71.4 g) in N-methylpyrrolidone (73.0 g), dibutyltin The mixture was heated at 80 to 90 ° C. for 3 hours in a nitrogen atmosphere in the presence of dilaurate (0.2 g). The reaction mixture was cooled to 80 ° C., to which triethylamine (8.8 g) was added and mixed, and 230 g of this mixture was withdrawn and added into water (382 g) under strong stirring. Then, 35 wt% of 2-methyl-1,5-pentanediamine aqueous solution (5.8 g) was added to obtain an aqueous polyurethane resin dispersion.

(Water vapor permeability)
The aqueous polyurethane resin dispersions obtained in Examples 1 to 3 and Comparative Example 1 were uniformly coated on a glass plate so that the film thickness after drying was about 0.08 mm. Next, after standing at room temperature for 16 hours, it was dried at 60 ° C. for 1 hour and further at 120 ° C. for 3 hours to obtain a polyurethane resin film. After peeling the obtained polyurethane resin film from the glass plate, water vapor permeability was measured according to JIS Z0208 under conditions of 273.15K and 1.013 × 10 ⁵ Pa. The smaller the number, the lower the water vapor permeability and the higher the gas barrier property.

From the comparison of Examples 1 to 3 and Comparative Example 1 in Table 1, when the polyurethane resin contains a structural unit derived from a polycarbonate polyol having an alicyclic structure in the main chain, the water vapor permeability of the polyurethane resin film obtained is It was less than 4.0 × 10 ⁻¹⁰ cm ³ · cm / cm ² · s · Pa and had high water vapor gas barrier properties. Among them, from the comparison of Examples 1 and 2 with Example 3, (1) the water vapor transmission of the polyurethane resin film obtained as the content of the alicyclic structure of the polycarbonate polyol compound having an alicyclic structure in the main chain is higher The properties were lower and it had higher water vapor gas barrier properties. Furthermore, from the comparison of Example 1 and Example 2, the higher the content of the alicyclic structure of (2) polyurethane resin, the more remarkable the effect was shown. Further, from the comparison of Example 1 and Example 2, (3) the polyurethane resin contains the structural unit derived from dicyclohexylmethane-4,4'-diisocyanate as compared with the case where the structural unit derived from isophorone diisocyanate is contained. The case was found to be particularly effective for water vapor gas barrier properties.

  Since a water vapor barrier urethane resin for film coating has a good water vapor barrier property, a coating material for film lamination for a packaging material, a coating material for a protective film for a solar cell, a coating material for a barrier substrate for a display element, etc. The coating material for electronic materials, the coating material for construction materials, the coating material for industrial materials, etc. can be suitably used if it is a use which requires water vapor barrier property.

Claims (9)

An aqueous polyurethane resin dispersion for water vapor gas barrier coating, wherein a polyurethane resin is dispersed in an aqueous medium,
The polyurethane resin contains a structural unit derived from a polycarbonate polyol compound having an alicyclic structure in its main chain,
Water vapor permeability of the polyurethane resin film formed from the aqueous polyurethane resin dispersion for water vapor gas barrier coating was measured according to JIS Z0208 under the conditions of film thickness 0.08 mm, 273.15 K, 1.013 × 10 ⁵ Pa Is less than 4.0 × 10 ⁻¹⁰ cm ³ · cm / cm ² · s · Pa,
Waterborne polyurethane resin dispersion for water vapor gas barrier coating.   The water-based polyurethane resin dispersion for water vapor gas barrier coat according to claim 1, wherein the content of the alicyclic structure of the polycarbonate polyol having an alicyclic structure in the main chain is 1 to 50% by weight.   The aqueous polyurethane resin dispersion for water vapor gas barrier coat according to claim 1 or 2, wherein the polyurethane resin further comprises a structural unit derived from a polyisocyanate compound having an alicyclic structure.   The water-based polyurethane resin dispersion for water vapor gas barrier coat according to claim 3, wherein the polyisocyanate compound having an alicyclic structure is isophorone diisocyanate and / or dicyclohexylmethane-4,4'-diisocyanate.   The water-based polyurethane resin dispersion for water vapor gas barrier coat according to any one of claims 1 to 4, wherein the content of the alicyclic structure in the polyurethane resin is 5 to 50% by weight.   A paint composition comprising the aqueous polyurethane resin dispersion for water vapor gas barrier coat according to any one of claims 1 to 5.   The coating composition containing the water-based polyurethane resin dispersion for water-vapor barrier coatings of any one of Claims 1-5.   A polyurethane resin film formed from the aqueous polyurethane resin dispersion for water vapor gas barrier coating according to any one of claims 1 to 5.   The polyurethane resin film laminated body on which the polyurethane resin film formed from the aqueous | water-based polyurethane resin dispersion for water vapor barrier coats of any one of Claims 1-5 was laminated | stacked on at least one of a base material.