Polyurethane resin aqueous dispersion, composite molding, and method for producing composite molding

Abstract

To provide an aqueous dispersion of a polyurethane resin capable of increasing transparency of a composite molding thereof when compositing even when using a fibrous cellulose having an average fiber diameter of 10 nm or more capable of making a film by a filtration method, and capable of increasing adhesion to a conductive pattern layer, and a composite molding of a polyurethane resin and a fibrous cellulose.SOLUTION: An aqueous dispersion of a polyurethane resin is used for producing a composite molding comprising a fibrous cellulose and a polyurethane resin, wherein a fiber diameter of the fibrous cellulose is 10 nm or more, the polyurethane resin has at least a structure derived from a polyol, a structure derived from a polyisocyanate, and a structure derived from a polyamine, and ionicity of the aqueous dispersion of the polyurethane resin is anionic.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an aqueous polyurethane resin dispersion, a composite molded article, and a method for producing the composite molded article. [Background technology]

[0002] In recent years, from the perspectives of global warming and decarbonization, there has been a desire in many fields to develop biomass-derived materials that can replace fossil resources. Among these, cellulose nanofibers (hereinafter referred to as "CNF"), a type of biomass-derived material made of fine fibrous cellulose, have attracted attention as a highly functional material. Because CNFs have excellent properties such as high strength, transparency, a low coefficient of linear thermal expansion, and flexibility, composite molded products of CNFs and resins (hereinafter referred to as "CNF-resin composite molded products") are being investigated for various applications in the fields of automotive materials, electronic materials, etc. In particular, in the field of electronic materials, highly transparent CNF-resin composite molded product sheets are expected to be used as flexible transparent substrates for liquid crystal displays such as organic electroluminescence (EL) displays.

[0003] Methods for compounding CNF and resin include, for example, compounding chemically modified CNF and olefin-based resin in a twin-screw kneader, and compounding by mixing an aqueous dispersion of CNF with an aqueous solution or dispersion of resin. More specifically, for example, Patent Document 1 discloses a method for producing a transparent CNF-resin composite molded product by compounding CNFs having a fiber diameter of 3 to 5 nm with a resin. Furthermore, Patent Document 2 discloses a method for producing a porous film-like CNF-resin composite molding by filtering a mixture of an aqueous dispersion of mechanically defibrated CNF and an aqueous dispersion of resin, and then contacting the filtered residue with an organic solvent.

[0004] However, although the method described in Patent Document 1 uses CNFs that have been defibrated to an average fiber diameter of less than 10 nm, and thus a highly transparent film can be formed, CNFs with an average fiber diameter of less than 10 nm have a high affinity for water, and therefore all of the water contained in the mixture of the aqueous dispersion of CNFs and the aqueous dispersion of resin must be removed by heat drying. When a CNF-resin composite molded product is produced by removing water only by heat drying, a problem arises in that a large amount of energy is required to remove the water. On the other hand, in Patent Document 2, a mixed liquid of an aqueous dispersion of CNF and an aqueous dispersion of resin is dehydrated by filtration. Although the filtration method is energy-saving and simple, the porous film-like CNF-resin composite molded product described in Patent Document 2 is white and opaque. In addition, the inventors attempted to produce transparent CNF-resin composite moldings by filtering a mixture of an aqueous dispersion of CNFs with an average fiber diameter of less than 10 nm and an aqueous dispersion of resin, but the drainage was very poor, making it difficult to produce CNF-resin composite moldings by filtration.

[0005] However, when CNF-only molded bodies or CNF-resin composite molded bodies are applied to electronic materials such as flexible transparent substrates, it is necessary to form a conductive pattern layer, for example, by applying and drying a conductive paint on the CNF-resin composite molded body. However, CNF has a problem in that it has low adhesion to the conductive pattern layer, and the conductive pattern layer easily peels off from the molded article. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2020-193258 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-116905 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made in view of the above circumstances, and aims to provide an aqueous dispersion of polyurethane resin and fibrous cellulose that can enhance the transparency of the composite molded article when composited and can enhance adhesion to a conductive pattern layer, even when using fibrous cellulose with an average fiber diameter of 10 nm or more that can be used to produce a film by a filtration method. Another aim of the present invention is to provide a method for producing a composite molded article of polyurethane resin and fibrous cellulose by a filtration method using fibrous cellulose with an average fiber diameter of 10 nm or more, with low energy consumption. [Means for solving the problem]

[0008] That is, the present invention is as follows. [1] An aqueous polyurethane resin dispersion used for producing a composite molded article of fibrous cellulose and a polyurethane resin, comprising: The fiber diameter of the fibrous cellulose is 10 nm or more, The polyurethane resin comprises at least It has a structure derived from a polyol, a structure derived from a polyisocyanate, and a structure derived from a polyamine, and the ionicity of the aqueous polyurethane resin dispersion is anionic. Polyurethane resin aqueous dispersion. [2] The aqueous polyurethane resin dispersion according to [1], wherein the polyol is at least one selected from the group consisting of polycarbonate diols, polyester diols, and polyether diols. [3] The aqueous polyurethane resin dispersion according to [1] or [2], wherein the polyol contains a polycarbonate diol. [4] The aqueous polyurethane resin dispersion according to any one of [1] to [3], wherein the polyisocyanate includes at least one selected from the group consisting of an aliphatic isocyanate and an alicyclic isocyanate. [5] The aqueous polyurethane resin dispersion according to any one of [1] to [4], wherein the polyurethane resin further has a structure derived from a polyalkylene glycol monoalkyl ether. [6] A polyurethane resin composition comprising the aqueous polyurethane resin dispersion according to any one of [1] to [5] and fibrous cellulose, A polyurethane resin composition, wherein the fibrous cellulose has a fiber diameter of 10 nm or more. [7] A composite molded article of a polyurethane resin having at least a polyol-derived structure, a polyisocyanate-derived structure, and a polyamine-derived structure, and having an anionic ionic property, and fibrous cellulose, A composite molded body, wherein the fiber diameter of the fibrous cellulose is 10 nm or more. [8] The composite molded article according to [7], wherein the content of the polyurethane resin is 10 to 150 parts by mass per 100 parts by mass of the fibrous cellulose. [9] [7] or [8]. A conductive circuit board having the composite molded body according to [7] or [8] and a conductive pattern on the surface thereof.

[10] A method for producing a composite molded body according to [7] or [8], comprising a step of obtaining a composite of fibrous cellulose containing water and a polyurethane resin by filtering the polyurethane resin composition according to [6]. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide an aqueous dispersion of polyurethane resin and a composite molded article of polyurethane resin and fibrous cellulose, which can enhance the transparency of the composite molded article when composited and can enhance adhesion to a conductive pattern layer, even when using fibrous cellulose having an average fiber diameter of 10 nm or more that can be used to produce a film by a filtration method. Furthermore, it is possible to provide a method for producing a composite molded article of polyurethane resin and fibrous cellulose by a filtration method using fibrous cellulose having an average fiber diameter of 10 nm or more, with low energy consumption. DETAILED DESCRIPTION OF THE INVENTION

[0010] Polyurethane resin aqueous dispersion The polyurethane resin aqueous dispersion is an aqueous polyurethane resin dispersion used for producing a composite molded article of fibrous cellulose and a polyurethane resin, The fiber diameter of the fibrous cellulose is 10 nm or more, The polyurethane resin comprises at least It has a structure derived from a polyol, a structure derived from a polyisocyanate, and a structure derived from a polyamine, The ionicity of the aqueous polyurethane resin dispersion is anionic. By using the above-mentioned aqueous polyurethane resin dispersion, a composite molded article of urethane resin and fibrous cellulose, which is composited with fibrous cellulose having a fiber diameter of 10 nm or more, has high transparency.

[0011] Fibrous cellulose The fibrous cellulose is not particularly limited and refers to, for example, cellulose fibers obtained by defibrating a cellulose raw material. In this specification, among the fibrous cellulose, fibrous cellulose having an average fiber diameter of 1000 nm or less is sometimes referred to as "fine fibrous cellulose" or "CNF" (Cellulose Nano Fiber). The cellulose raw material from which the fibrous cellulose is produced is not particularly limited as long as it is a known material, and any material can be used. Examples include plants (e.g., wood, bamboo, hemp, jute, kenaf, agricultural waste, cloth, pulp (softwood unbleached kraft pulp (NUKP), softwood bleached kraft pulp (NBKP), hardwood unbleached kraft pulp (LUKP), hardwood bleached kraft pulp (LBKP), softwood unbleached sulfite pulp (NUSP), softwood bleached sulfite pulp (NBSP), thermomechanical pulp (TMP), recycled pulp, and waste paper), animals (e.g., ascidians), algae, microorganisms (e.g., acetic acid bacteria (Acetobacter)), and microbial products. These cellulose raw materials may be used alone or in combination of two or more. The fibrous cellulose can be obtained by defibrating the cellulose raw material. The defibration method is not particularly limited as long as it is a known method. Examples of the defibration method include chemical treatments such as TEMPO oxidation, enzymatic hydrolysis, and ion-selective liquid dissolution; and mechanical (physical) treatments such as underwater head-on collision, hydraulic penetration pulverization, high-pressure homogenizer, microfluidizer, grinder, biaxial kneading, and ball mill pulverization. These methods may also be combined for defibration.

[0012] The average fiber diameter of the fibrous cellulose is 10 nm or more, preferably 10 to 150 nm, more preferably 11 to 80 nm, and particularly preferably 12 to 30 nm. The average fiber diameter can also be referred to as the average fiber width. The average fiber diameter can be measured using an electron microscope or the like. The average fiber length of the fibrous cellulose is not particularly limited. The cross-sectional shape of the fibrous cellulose is not particularly limited.

[0013] Polyurethane Resin The polyurethane resin contained in the polyurethane resin aqueous dispersion has at least a structure derived from a polyol, a structure derived from a polyisocyanate, and a structure derived from a polyamine. The polyurethane resin aqueous dispersion is preferably an anionic polyurethane resin aqueous dispersion obtained by dispersing in water a polyurethane resin obtained by reacting a urethane prepolymer obtained by reacting a polyol compound, a polyisocyanate compound, and a compound having an anionic hydrophilic group with a polyamine compound as a chain extender.

[0014] Polyol-derived structure The structure derived from polyol in polyurethane resin is the structure obtained after the urethane reaction of the raw material polyol compound.

[0015] The polyol compound is not particularly limited as long as it has two or more hydroxyl groups (—OH) in one molecule. Examples of the polyol compound include polyester polyol, polycarbonate polyol, polyether polyol, and polyhydric alcohol.

[0016] Examples of the polyester polyol include reaction products obtained by direct esterification or transesterification between an acid component and a polyol compound. Examples of the acid component include aromatic carboxylic acids such as phthalic acid, naphthalenedicarboxylic acid, biphenyldicarboxylic acid, and tetrahydrophthalic acid; alicyclic carboxylic acids such as hydrogenated products of these aromatic carboxylic acids; and aliphatic carboxylic acids such as malonic acid, succinic acid, tartaric acid, oxalic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, alkylsuccinic acid, linoleic acid, phthalic acid, maleic acid, fumaric acid, mesaconic acid, citraconic acid, and itaconic acid. Anhydrides, salts, and derivatives (alkyl esters, acid halides) of these compounds can also be used. Examples of the polyol compound include polyhydric alcohols such as diols and triols, and the compounds exemplified below as polyether polyols. Further examples of polyester polyols include reaction products obtained by direct esterification of a polyol compound with a lactone such as caprolactone, valerolactone, or butyrolactone, or a hydroxycarboxylic acid obtained by hydrolysis and ring-opening of the lactone.

[0017] Examples of the polycarbonate polyol include reaction products of one or more polyhydric alcohols having 2 to 20 carbon atoms, such as 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, polypropylene glycol, and polytetramethylene glycol, with phosgene, dialkyl carbonates having an alkyl group with 1 to 6 carbon atoms, alkylene carbonates having an alkylene group with 2 to 6 carbon atoms, diaryl carbonates having an aryl group with 6 to 9 carbon atoms, and cyclic carbonates. For example, polytetramethylene carbonate diol, polypentamethylene carbonate diol, polyhexamethylene carbonate diol, polyneopentyl carbonate diol, 3-methyl-5-pentane carbonate diol, and poly(1,4-cyclohexanedimethylene carbonate) diol, as well as random / block copolymers thereof, can be used. The polycarbonate diol may be a polyester polycarbonate polyol, such as a reaction product of a polyester glycol (e.g., polycaprolactone polyol) with an alkylene carbonate, or a reaction product obtained by reacting a lactone (e.g., caprolactone, valerolactone, or butyrolactone) or an organic dicarboxylic acid with a reaction product of an alkylene carbonate with a polyhydric alcohol.

[0018] The polyether polyol is not particularly limited, and polyether polyols generally used in the art can be used. Examples of the polyether polyol include polyalkylene ether glycols having a repeating unit of alkylene oxide having 2 to 12 carbon atoms in the molecular structure; adducts of alkylene oxides having 2 to 12 carbon atoms, such as ethylene oxide and propylene oxide, with aliphatic polyhydric alcohols having 2 to 20 carbon atoms, such as 1,2-propanediol, 1,3-propanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, trimethylolpropane, glycerin, polyglycerin, and pentaerythritol; bisphenol A, and the like. Examples of the alkylene oxide include adducts of alkylene oxides having 2 to 12 carbon atoms, such as ethylene oxide and propylene oxide, to aromatic polyols such as olefin A; and adducts of alkylene oxides having 2 to 12 carbon atoms, such as ethylene oxide and propylene oxide, to amine compounds such as ethylenediamine. For example, polyethylene glycol, polypropylene glycol, a block or random copolymer of polyethylene glycol / polytetramethylene glycol, polytetramethylene ether glycol, and polyhexamethylene ether glycol can be used. These may be used alone or in combination of two or more.

[0019] The polyhydric alcohol is not particularly limited. Specific examples of the polyhydric alcohol include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 2-methyl-2-butyl-1,3-propanediol, and 2,2,4-trimethylol. Examples of the alcohol include dihydric alcohols such as 2-ethyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 2,4-diethyl-1,5-pentanediol, 2-ethyl-2-butyl-1,3-propanediol, diethylene glycol, dipropylene glycol, and triethylene glycol; and trihydric or higher alcohols such as glycerin, trimethylolpropane, pentaerythritol, and sorbitol.

[0020] The polyol compound is preferably at least one selected from the group consisting of polyester diols, polycarbonate diols, polyether diols, and polyhydric alcohols. The hydroxyl value of the polyol compound is not particularly limited and may be, for example, 1 to 500 mgKOH / g, 2 to 350 mgKOH / g, 5 to 200 mgKOH / g, or 10 to 150 mgKOH / g. In this specification, the hydroxyl value is measured in accordance with Method A of JIS K1557-1:2007.

[0021] Polyisocyanate-derived structure The structure derived from polyisocyanate in polyurethane resin is the structure obtained after the raw material polyisocyanate compound undergoes a urethane reaction.

[0022] A polyisocyanate compound is a compound having two or more isocyanate groups (-NCO) in one molecule. Any polyisocyanate compound conventionally used in the production of polyurethanes can be used without any particular limitation. Examples of polyisocyanate compounds include organic polyisocyanate compounds such as aromatic polyisocyanates, araliphatic polyisocyanates, alicyclic polyisocyanates, and aliphatic polyisocyanates; and polyisocyanate derivatives containing derivatives of these organic polyisocyanate compounds. The organic polyisocyanate compound may be a bifunctional compound, i.e., a compound having two isocyanate groups (-NCO) in one molecule, such as an aromatic diisocyanate, an araliphatic diisocyanate, an alicyclic diisocyanate, or an aliphatic diisocyanate. In addition, compounds having three or more functional groups, i.e., compounds having three or more isocyanate groups (-NCO) in one molecule, such as aromatic polyisocyanates, araliphatic polyisocyanates, alicyclic polyisocyanates, or aliphatic polyisocyanates, can be used. The polyisocyanate compounds may be used alone or in combination of two or more.

[0023] The polyisocyanate compound preferably contains at least one selected from the group consisting of an aliphatic isocyanate compound and an alicyclic isocyanate compound.

[0024] The aliphatic isocyanate compound includes an aliphatic diisocyanate and a tri- or higher functional aliphatic polyisocyanate.

[0025] Examples of the aliphatic diisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate, and 2,6-diisocyanate methyl caproate.

[0026] Examples of the tri- or higher functional aliphatic polyisocyanates include trifunctional aliphatic polyisocyanates such as lysine ester triisocyanate, 1,4,8-triisocyanato octane, 1,6,11-triisocyanato undecane, 1,8-diisocyanato-4-isocyanato methyl octane, 1,3,6-triisocyanato hexane, and 2,5,7-trimethyl-1,8-diisocyanato-5-isocyanato methyl octane.

[0027] The alicyclic isocyanate compound includes an alicyclic diisocyanate and a tri- or higher functional alicyclic polyisocyanate.

[0028] Examples of the alicyclic diisocyanate include 1,3-cyclopentene diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, and 1,4-bis(isocyanatomethyl)cyclohexane.

[0029] Examples of the trifunctional or higher alicyclic polyisocyanate include 1,3,5-triisocyanate cyclohexane, 1,3,5-trimethylisocyanate cyclohexane, 2-(3-isocyanate propyl)-2,5-di(isocyanate methyl)bicyclo(2.2.1)heptane, 2-(3-isocyanate propyl)-2,6-di(isocyanate methyl)bicyclo(2.2.1)heptane, 3-(3-isocyanate propyl)-2,5-di(isocyanate methyl)bicyclo(2.2.1)heptane, 5-(2-isocyanate ethyl)bicyclo(2.2.1)heptane, )-2-isocyanatemethyl-3-(3-isocyanatepropyl)bicyclo(2.2.1)heptane, 6-(2-isocyanateethyl)-2-isocyanatemethyl-3-(3-isocyanatepropyl)bicyclo(2.2.1)heptane, 5-(2-isocyanateethyl)-2-isocyanatemethyl-2-(3-isocyanatepropyl)bicyclo(2.2.1)heptane, 6-(2-isocyanateethyl)-2-isocyanatemethyl-2-(3-isocyanatepropyl)bicyclo(2.2.1)heptane, etc.

[0030] The polyisocyanate compound may further contain an aromatic isocyanate compound. The aromatic isocyanate compound is not particularly limited, and includes, for example, aromatic diisocyanates and tri- or higher functional aromatic polyisocyanates. Examples of the aromatic diisocyanate include m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4- or 2,6-tolylene diisocyanate, 4,4'-toluidine diisocyanate, and 4,4'-diphenyl ether diisocyanate.

[0031] Examples of the tri- or higher functional aromatic polyisocyanate include trifunctional aromatic polyisocyanates such as triphenylmethane-4,4',4"-triisocyanate, 1,3,5-triisocyanate benzene, and 2,4,6-triisocyanate toluene; and tetrafunctional aromatic polyisocyanates such as 4,4'-diphenylmethane-2,2',5,5'-tetraisocyanate.

[0032] The polyisocyanate derivative is not particularly limited, and examples thereof include polymers of the above-mentioned polyisocyanate (monomer) (for example, dimers, trimers (for example, isocyanurate-modified products, iminooxadiazinedione-modified products), pentamers, heptamers, etc.), allophanate-modified products (for example, allophanate-modified products produced by further adding an isocyanate group of the polyisocyanate (monomer) to a urethane group formed by the reaction of the above-mentioned polyisocyanate (monomer) with a low-molecular-weight polyol described below), adducts (for example, adducts (alcohol adducts) produced by the reaction of a polyisocyanate (monomer) with a low-molecular-weight polyol described below), biuret-modified products ( Examples of such compounds include biuret-modified compounds produced by reacting the above-mentioned polyisocyanate (monomer) with water or amines, urea-modified compounds (e.g., urea-modified compounds produced by adding an isocyanate group of the polyisocyanate (monomer) to a urea group formed by the reaction of the above-mentioned polyisocyanate (monomer) with a diamine), oxadiazinetrione-modified compounds (e.g., oxadiazinetrione-modified compounds produced by the reaction of the above-mentioned polyisocyanate (monomer) with carbon dioxide), carbodiimide-modified compounds (e.g., carbodiimide-modified compounds produced by the decarboxylation condensation reaction of the above-mentioned polyisocyanate (monomer)), uretdione-modified compounds, and uretonimine-modified compounds. Further examples include polymethylene polyphenyl polyisocyanate (crude MDI, polymeric MDI), and the like.

[0033] The content of the polyisocyanate compound is usually 10 to 100 parts by mass, preferably 20 to 70 parts by mass, and more preferably 30 to 60 parts by mass, relative to 100 parts by mass of the polyol compound. The molar ratio (R value: NCO groups / OH groups) of the hydroxyl groups of the polyol compound and the monol compound used as needed, which will be described later, to the isocyanate groups of the polyisocyanate compound is preferably 0.5 to 4, more preferably 0.8 to 3, and even more preferably 0.9 to 2. Here, the R value is also referred to as INDEX.

[0034] Polyamine-derived structure The structure derived from polyamine in the polyurethane resin is the structure obtained after the reaction of the polyamine compound, which is a chain extender. The polyamine compound is not particularly limited and includes, for example, aliphatic polyamines such as ethylenediamine, trimethylenediamine, propylenediamine, diethylenetriamine, and triethylenetetramine; aromatic polyamines such as metaxylenediamine, tolylenediamine, and diaminodiphenylmethane; alicyclic polyamines such as piperazine and isophoronediamine; and polyhydrazides such as hydrazine and adipic acid dihydrazide. The polyamine compounds may be used alone or in combination of two or more. In addition to the polyamine compounds, chain extenders other than polyamine compounds, such as water and ammonia, can be used.

[0035] The content of the polyamine compound is usually 0.1 to 5.0 parts by mass, preferably 0.3 to 3.0 parts by mass, and more preferably 0.4 to 1.0 parts by mass, relative to 100 parts by mass of the polyol compound.

[0036] Compounds containing anionic hydrophilic groups In order to change the ionic nature of the polyurethane resin aqueous dispersion to anionic nature, a compound having an anionic hydrophilic group may be added. Specific examples of the anionic hydrophilic group include a carboxy group, a sulfonic acid group, a phosphate group, a halogen group, and a sulfate group. Specific examples of hydrophilic compounds having an anionic hydrophilic group include compounds having both an anionic group and an active hydrogen group, and more specific examples include compounds having a carboxy group of a monohydroxycarboxylic acid or polyhydroxycarboxylic acid as the anionic group. Examples of monohydroxycarboxylic acids include 1-hydroxyacetic acid, 3-hydroxypropanoic acid, 12-hydroxy-9-octadecanoic acid, hydroxypivalic acid, and lactic acid. Examples of compounds having a carboxy group of a polyhydroxycarboxylic acid as an anionic group include dimethylolacetic acid, 2,2-dimethylolbutanoic acid, 2,2-dimethylolpentanoic acid, dihydroxysuccinic acid, and dimethylolpropionic acid. Further, compounds having both a sulfonic acid group and an active hydrogen group are also included, and more specifically, for example, isethionic acid is included. Among these, compounds having both an anionic group and an active hydrogen group are preferably hydroxypivalic acid, dimethylolpropionic acid, dimethylolbutanoic acid, etc.

[0037] The anionic hydrophilic group added to the polyisocyanate is preferably neutralized with an amine compound, which is a basic substance. Specific examples of the amine compound include ammonia and water-soluble amino compounds. Specific examples of water-soluble amino compounds include monoethanolamine, ethylamine, dimethylamine, diethylamine, triethylamine, propylamine, dipropylamine, isopropylamine, diisopropylamine, triethanolamine, butylamine, dibutylamine, 2-ethylhexylamine, ethylenediamine, propylenediamine, methylethanolamine, dimethylethanolamine, diethylethanolamine, and morpholine. Tertiary amines such as triethylamine and dimethylethanolamine can also be used. These amine compounds may be used alone or in combination of two or more.

[0038] When the compound having an anionic hydrophilic group is a compound having two hydroxyl groups, such as dimethylolpropionic acid or dimethylolbutanoic acid, it can also be called a polyol compound. In this case, the dimethylolpropionic acid or dimethylolbutanoic acid forms a structure derived from the polyol of the polyurethane resin after the reaction.

[0039] The content of the compound having an anionic hydrophilic group is usually 2.0 to 20 parts by mass, preferably 4.0 to 15.0 parts by mass, and more preferably 6.0 to 10.0 parts by mass, relative to 100 parts by mass of the polyol compound.

[0040] Monool compounds The polyurethane resin may have a structure derived from a monool in addition to a structure derived from a polyol. When the polyurethane resin has a structure derived from a monool, the structure derived from the monool in the polyurethane structure is a structure obtained after the monool compound has reacted. The monool compound is a compound containing one hydroxyl group. Examples of the monool compound include polyethylene glycol monomethyl ether, polyoxyethylene polyoxypropylene butyl ether, 2-hydroxyethyl methacrylate, and alcohols such as methanol, ethanol, isopropyl alcohol, and butanol. These may be used alone or in combination of two or more.

[0041] The monool compound preferably has a structure derived from a polyalkylene glycol monoalkyl ether represented by the following general formula: RO-(C2H4O) m (C3H6O) n -H (1) Here, R represents an alkyl group having 1 to 10 carbon atoms, m represents an integer of 1 or more, and n represents an integer of 0 or more. The polyalkylene glycol monoalkyl ether is a compound obtained by addition polymerization of ethylene oxide and, optionally, propylene oxide to a monoalcohol having 1 to 10 carbon atoms, and has an alkyl group R having 1 to 10 carbon atoms derived from the monoalcohol. The alkyl group R may have a linear or branched structure. The alkyl group R preferably has 1 to 4 carbon atoms. m is an integer of 1 or more and preferably 100 or less, and n is an integer of 0 or more and preferably 100 or less. When both ethylene oxide and propylene oxide are added, the ethylene oxide or the propylene oxide may be added first to the monoalcohol, and the addition state may be block addition or random addition. The number average molecular weight of the polyalkylene glycol monoalkyl ether represented by general formula (1) is preferably 500 to 5,000. The polyalkylene glycol monoalkyl ether represented by general formula (1) may be used alone or in combination of two or more. As the polyalkylene glycol monoalkyl ether, polyethylene glycol monomethyl ether and the like are preferred.

[0042] When a monool compound is contained, the amount thereof is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, and even more preferably 20 parts by mass or less, relative to 100 parts by mass of the polyol compound.

[0043] Method for producing aqueous polyurethane resin dispersion The polyurethane resin aqueous dispersion can be produced by a known method. For example, a polyol compound, a polyisocyanate compound, and an anionic hydrophilic group-containing compound are reacted with each other, and the contained hydrophilic groups are neutralized as necessary to obtain a urethane prepolymer, which is then emulsified using water and further subjected to a chain extension reaction with a polyamine, thereby obtaining the urethane prepolymer. When reacting the polyol compound with the polyisocyanate compound, a solvent may be used as needed. Any organic solvent can be used as the solvent. Examples of the organic solvent include acetone, methyl ethyl ketone, tetrahydrofuran, dioxane, ethyl acetate, and butyl acetate. The reaction conditions are, for example, 60 to 80°C for about 2 to 4 hours, preferably about 70°C for about 3 hours, and if necessary, the reaction mixture can be cooled to 5 to 45°C before the next step (neutralization of the hydrophilic groups contained therein).

[0044] To promote the reaction, any known urethanization catalyst can be used without limitation, including, for example, inorganic metal catalysts, organometallic catalysts, and amine catalysts. Examples of the inorganic metal catalyst include inorganic tin catalysts and inorganic bismuth catalysts. Examples of the organometallic catalyst include an organotin catalyst, an organolead catalyst, and an organobismuth catalyst. Examples of the organotin catalyst include dioctyltin dilaurate, dibutyltin diacetate, dibutyltin dilaurate, and dioctyltin diacetate. Examples of the organic lead catalyst include lead octoate, lead octenoate, and lead naphthenate. Examples of the organic bismuth catalyst include bismuth octoate and bismuth neodecanoate. Examples of the amine catalyst include diethylenetriamine, triethylamine, and N,N-dimethylcyclohexylamine.

[0045] The molar equivalent ratio of isocyanate groups to hydroxyl groups used to obtain the urethane prepolymer is not particularly limited, as long as the ratio is isocyanate groups:hydroxyl groups=1.0 or more:1. The molar equivalent ratio is preferably 1.05 to 3:1, and more preferably 1.20 to 2.2:1, since this allows the urethane prepolymer to have a low viscosity and a stable emulsion to be obtained.

[0046] The hydrophilic group is an anionic group. The compound into which an anionic hydrophilic group can be introduced is a compound having an anionic hydrophilic group. Specific examples of the anionic hydrophilic group include a carboxy group, a sulfonic acid group, a phosphate group, a halogen group, and a sulfate group. The compound capable of introducing the anionic hydrophilic group is preferably hydroxypivalic acid, dimethylolpropionic acid, dimethylolbutanoic acid, or the like. The content (number of moles) of the anionic hydrophilic group in the urethane prepolymer is not particularly limited, and the content of the anionic hydrophilic group is preferably 0.01 to 2.5 mmol / g, more preferably 0.02 to 1.8 mmol / g, and even more preferably 0.03 to 1.6 mmol / g.

[0047] The amount of water used for the emulsification is preferably about 100 to 900 parts by mass per 100 parts by mass of the urethane prepolymer.

[0048] In the chain extension, the above-mentioned polyamine compound is used as a chain extender. The polyamine compound may be used alone or in combination of two or more. In addition to the polyamine compound, a chain extender other than the polyamine compound, such as water or ammonia, may also be used. The chain extension conditions are, for example, about 40 to 60° C. for about 0.5 to 2 hours, preferably about 50° C. for about 1 hour.

[0049] The content of the polyurethane resin (solid content) in the polyurethane resin aqueous dispersion is not particularly limited, and is, for example, preferably 1 to 60 mass % relative to the total amount of the polyurethane resin aqueous dispersion, more preferably 3 to 55 mass %, and even more preferably 4 to 50 mass %.

[0050] Polyurethane resin composition The polyurethane resin composition contains the polyurethane resin aqueous dispersion and the fibrous cellulose. The polyurethane resin composition can be obtained by mixing the aqueous polyurethane resin dispersion produced as described above with fibrous cellulose having a fiber diameter of 10 nm or more.

[0051] The fibrous cellulose is preferably used in the form of an aqueous dispersion of the fibrous cellulose. The aqueous dispersion of fibrous cellulose contains water as a dispersion medium, and the fibrous cellulose is dispersed in the dispersion medium. An aqueous medium is used as the dispersion medium, and water alone may be used, but it may also be used in combination with a hydrophilic organic solvent that is miscible with water, such as water-soluble alcohols (e.g., ethanol, methanol, isopropanol, isobutanol, sec-butanol, tert-butanol, methyl cellosolve, ethyl cellosolve, ethylene glycol, glycerin, etc.), ethers (e.g., ethylene glycol dimethyl ether, 1,4-dioxane, tetrahydrofuran, etc.), ketones (e.g., acetone, methyl ethyl ketone, etc.), N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, etc. The concentration of fibrous cellulose in the aqueous dispersion of fibrous cellulose is not particularly limited, and the lower limit may be, for example, 0.01% by mass or more, or 0.05% by mass or more, and the upper limit may be, for example, 20% by mass or less, 10% by mass or less, or 0.5% by mass or less.

[0052] The content of the polyurethane resin (solid content) in the polyurethane resin composition is usually 10 to 150 parts by mass, preferably 15 to 125 parts by mass, and more preferably 20 to 100 parts by mass, per 100 parts by mass of the fibrous cellulose (solid content).

[0053] Composite molding of polyurethane resin and fibrous cellulose The composite molded product of polyurethane resin and fibrous cellulose (hereinafter referred to as "polyurethane resin-fibrous cellulose composite molded product" or simply "composite molded product") is a composite molded product of polyurethane resin, which has at least a polyol-derived structure, a polyisocyanate-derived structure, and a polyamine-derived structure, and is anionic in ionicity, and fibrous cellulose having an average fiber diameter of 10 nm or more. The composite molding contains a polyurethane resin having at least a polyol-derived structure, a polyisocyanate-derived structure, and a polyamine-derived structure, and is produced using an aqueous dispersion of polyurethane resin that is anionic in ionicity. Therefore, the composite molding has high transparency despite the average fiber diameter of the composite fibrous cellulose being as large as 10 nm or more.

[0054] The content of the polyurethane resin (solid content) in the composite molded body is typically 10 to 150 parts by mass, preferably 15 to 125 parts by mass, and more preferably 20 to 100 parts by mass, per 100 parts by mass of the fibrous cellulose (solid content).

[0055] Manufacturing method of composite molding The method for producing the composite molded article includes a step of obtaining a composite of water-containing fibrous cellulose and polyurethane resin by filtering the polyurethane resin composition. The method for producing the composite molded body preferably includes the steps of: a first step of mixing the polyurethane resin aqueous dispersion with the fibrous cellulose to obtain a polyurethane resin composition; A second step of obtaining a composite of water-containing fibrous cellulose and a polyurethane resin by filtering the polyurethane resin composition obtained in the first step; and The method includes a third step of drying the composite obtained in the second step to obtain a composite molded product of polyurethane resin and fibrous cellulose.

[0056] There are no particular limitations on the mixing method in the first step. For example, the polyurethane resin composition can be obtained by stirring an aqueous dispersion of polyurethane resin and an aqueous dispersion of fibrous cellulose.

[0057] The filtration method in the second step is a method of removing water from the polyurethane resin composition by filtration to form and collect a (semi)solid composite. It is not necessary to remove all of the water contained in the polyurethane resin composition. The filtration can be carried out by, for example, natural filtration, reduced pressure filtration (suction filtration), pressure filtration, etc.

[0058] The drying method in the third step is not particularly limited, and examples of the drying method include heat drying, reduced pressure drying, air drying, microwave drying, infrared drying, and freeze drying.

[0059] According to the manufacturing method of the present invention, a composite molded body can be easily produced by filtration. In addition, since a composite molded body can be produced by filtration, energy consumption can be reduced compared to when filtration is not possible and all moisture is removed by heat drying.

[0060] conductive circuit board The conductive circuit board comprises the composite molded body and a conductive pattern on the surface thereof. The conductive circuit board has excellent adhesion between the composite molded body and the conductive pattern. [Example]

[0061] The present invention will be explained in more detail below with reference to examples, but the technical scope of the present invention is not limited to these examples.

[0062] <Ingredients> Production of Polyurethane Resin Aqueous Dispersion (Production Examples 1 to 6, and Comparative Production Examples 1 and 2) [Polyol compounds] Ethanacole (registered trademark) UH-100: Polyhexamethylene carbonate diol, number average molecular weight 1000, manufactured by UBE Corporation, hydroxyl value (mgKOH / g): approximately 110 Ethanacole (registered trademark) UHC50-100: reaction product of polyhexamethylene carbonate diol and caprolactone, number average molecular weight 1000, manufactured by UBE Corporation, hydroxyl value (mgKOH / g): approximately 110 PTG-1000SN: Polytetramethylene ether glycol, number average molecular weight 1000, manufactured by Hodogaya Chemical Co., Ltd., hydroxyl value (mgKOH / g): 112 Nipporan (registered trademark) 4009, number average molecular weight 1000, manufactured by Tosoh Corporation, hydroxyl value (mgKOH / g): 112 PES: Polyester polyol, manufactured by Tosoh Corporation, hydroxyl value (mgKOH / g): approx. 350 1,4-Butanediol: Mitsubishi Chemical Corporation, molecular weight: 90.12 Trimethylolpropane: Perstorp [Anionic hydrophilic group-containing compound] Dimethylolpropionic acid (Bis-MPA, Perstorp) [Cationic hydrophilic group-containing compounds] N-methyldiethanolamine (amino alcohol MDA): manufactured by Nippon Nyukazai Co., Ltd.

[0063] [Monool compounds] Uniox (registered trademark) M-2000: Polyoxyethylene glycol monomethyl ether, average molecular weight 2000, manufactured by NOF Corporation

[0064] [Polyisocyanate compounds] Desmodur® W: Methylenebis(1,4-cyclohexanediyl)bisisocyanate, manufactured by Covestro VESTANAT® IPDI, manufactured by Evonik Duranate (registered trademark) 50M, manufactured by Asahi Kasei Chemicals Corporation

[0065] [Chain extender (polyamine compound)] Diethylenetriamine: Tosoh Corporation Ethylenediamine: Tosoh Corporation [Neutralizer] Triethylamine: Daicel Corporation [Quaternizing agent] Dimethyl sulfate: Tokyo Chemical Industry Co., Ltd. [catalyst] Neostan (registered trademark) U-600: Bismuth catalyst, manufactured by Nitto Kasei Co., Ltd.

[0066] Production of acrylic resin (Comparative Production Example 3) Stearyl acrylate: Kyoeisha Chemical Co., Ltd. 2-Hydroxyethyl acrylate: Fujifilm Wako Pure Chemical Industries, Ltd. Methacrylic acid: Fujifilm Wako Pure Chemical Industries, Ltd. Azobisisobutyronitrile: Fujifilm Wako Pure Chemical Industries, Ltd.

[0067] Preparation of polyurethane resin-fibrous cellulose composite molded body (Examples 1 to 8 and Comparative Examples 3 to 5) [Aqueous dispersion of fibrous cellulose] CNF-1: Mechanically defibrated CNF aqueous dispersion (bamboo bleached pulp, manufactured by Chuetsu Pulp Industries Co., Ltd.), average fiber diameter 13 nm (measured value. The surface of the thin film dried material was observed using an atomic force microscope SPA-400 manufactured by Seiko Instruments Inc., and the width of three fibers was averaged). CNF-2: TEMPO-oxidized CNF aqueous dispersion (product name RHEOCRYSTA (registered trademark) I-2SP, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), average fiber diameter 3 nm (measured value. The surface of the thin film-like dried product was observed using an atomic force microscope SPA-400 manufactured by Seiko Instruments Inc., and the width of three fibers was averaged).

[0068] [Aqueous resin dispersion] Polyurethane resin aqueous dispersions of Production Examples 1 to 6 and Comparative Production Examples 1 and 2 Comparative Example 3: Aqueous dispersion of acrylic resin

[0069] <Production example> Manufacturing Example 1 Ethyl alcohol UH-100 (59.42 parts by mass), Bis-MPA (4.85 parts by mass), Uniox M-2000 (3.87 parts by mass), Desmodur W (31.46 parts by mass), triethylamine (3.48 parts by mass), Neostan U-600 (0.05 parts by mass) and methyl ethyl ketone (62.91 parts by mass) were added to a flask and heated with stirring at 70 °C, and the reaction was carried out until the NCO% reached 1.15%. Since it became 1.18% or less which is the theoretical NCO% after the reaction calculated from the charged amount of the raw materials, it was judged that the urethanization reaction proceeded sufficiently and a urethane prepolymer having an isocyanate group at the terminal was formed. Subsequently, after cooling this reaction solution to 30 °C, water (308 parts by mass) was added dropwise and emulsified under strong stirring, and then diethylenetriamine (0.40 parts by mass) was dissolved in water (10 parts by mass) and added dropwise. Further, after heating and stirring at 45 °C for 1 hour, methyl ethyl ketone was distilled off under reduced pressure, water was added to adjust the solid content to 30%, and the aqueous dispersion 1 of the polyurethane resin of Production Example 1 was obtained.

[0070] <Measurement of NCO%> In the above Production Example 1, the NCO% was measured in accordance with Method A of JIS K 1603-1:2007, for example. Specifically, the residual NCO groups in the reaction solution were reacted with an excessive amount of dibutylamine, and then the residual dibutylamine was back-titrated with hydrochloric acid to calculate it. Also, when an amine compound was contained in the reaction solution, the amount of hydrochloric acid reacting with the amine compound in the reaction solution was measured, and the NCO% was calculated by correcting the amount of hydrochloric acid required for the back-titration.

[0071] Manufacturing Examples 2 to 6 The raw materials described in Table 1 were used in the amounts (parts by mass) described in Table 1, and the same operations as in Production Example 1 were carried out except for this, and the aqueous dispersions 2 to 6 of the polyurethane resins of Production Examples 2 to 6 were obtained respectively.

[0072] Comparative Manufacturing Example 1 Ethanacol UH-100 (67.10 parts by mass), Uniox M-2000 (10.02 parts by mass), Desmodur W (22.59 parts by mass), Neostan U-600 (0.05 parts by mass) and methyl ethyl ketone (42.63 parts by mass) were added to a flask and heated and stirred at 70 ° C. until the NCO% reached 0.86%. Since the theoretical NCO% calculated from the amount of raw materials added after the reaction was 0.97% or less, it was determined that the urethane reaction had progressed sufficiently and a urethane prepolymer having an isocyanate group at the end was produced. Subsequently, the reaction solution was cooled to 30 ° C., and water (235 parts by mass) was added dropwise under vigorous stirring to emulsify, and then diethylenetriamine (0.28 parts by mass) was dissolved in water (10 parts by mass) and added dropwise. After further heating and stirring at 45° C. for 1 hour, methyl ethyl ketone was distilled off under reduced pressure, and water was added to adjust the solid content to 30% to obtain an aqueous polyurethane resin dispersion of Comparative Production Example 1.

[0073] Comparative Manufacturing Example 2 Ethanacol UH-100 (59.42 parts by mass), amino alcohol MDA (4.31 parts by mass), Uniox M-2000 (3.87 parts by mass), Desmodur W (31.46 parts by mass), Neostan U-600 (0.005 parts by mass) and methyl ethyl ketone (64.18 parts by mass) were added to a flask and heated and stirred at 70 ° C. until the NCO% reached 1.11%. Since the theoretical NCO% calculated from the amount of raw materials added after the reaction was 1.20% or less, it was determined that the urethane reaction had progressed sufficiently and a urethane prepolymer having an isocyanate group at the end was produced. Subsequently, dimethyl sulfate (4.33 parts by mass) was added and heated and stirred at 50 ° C. to obtain a cationic urethane prepolymer. Next, this reaction solution was cooled to 30°C, and water (258 parts by mass) was added dropwise with strong stirring to emulsify, followed by the dropwise addition of diethylenetriamine (0.40 parts by mass) dissolved in water (10 parts by mass). After further heating and stirring at 45°C for 1 hour, methyl ethyl ketone was distilled off under reduced pressure, and water was added to adjust the solid content to 30% to obtain an aqueous polyurethane resin dispersion of Comparative Production Example 2.

[0074] Comparative Manufacturing Example 3 Stearyl acrylate (78 parts by mass), 2-hydroxyethyl acrylate (16 parts by mass), methacrylic acid (6 parts by mass), azobisisobutyronitrile (0.6 parts by mass), and methyl ethyl ketone (100 parts by mass) were added to a flask and copolymerized under stirring for 12 hours in a nitrogen atmosphere at 65 to 75°C. Subsequently, a 0.3% aqueous NaOH solution (568 parts by mass) was added to the reaction solution and dispersed, and the methyl ethyl ketone was distilled off under reduced pressure while heating using an evaporator. Water was then added to adjust the solids content to 15%, yielding an aqueous acrylic resin dispersion of Comparative Production Example 3.

[0075] [Table 1]

[0076] <Preparation and Evaluation of Polyurethane Resin-CNF (Cellulose Fiber) Composite Film> Example 1 10 g of CNF-1, the solid content of which had been adjusted to 0.5%, was mixed with 20 g of distilled water, and then 3 g of polyurethane resin aqueous dispersion 1 of Production Example 1, the solid content of which had been adjusted to 0.5%, was added and mixed. A planetary centrifugal mixer, Awatori Rentaro (manufactured by Thinky Corporation), was used for each mixing step (rotation speed: 2000 rpm, 5 minutes). The prepared mixed dispersion of fibrous cellulose and polyurethane resin was suction filtered using a membrane filter (grade: A100A047A, diameter: 47 mm, pore size: 1.0 μm) to obtain a hydrous film of a polyurethane resin-fibrous cellulose composite molded product. The suction filtration time was measured during the suction filtration. The obtained water-containing film was sandwiched between PTFE filter papers, which were then sandwiched between cellulose filter papers, and finally sandwiched between aluminum plates. A 1 kg weight was placed on the film and it was dried in an oven at 65° C. for one day, to obtain a polyurethane resin-fibrous cellulose composite molded film 1 of Example 1.

[0077] Examples 2 to 8 Polyurethane resin-fibrous cellulose composite molded film 2 to 8 of Examples 2 to 8 were obtained using the compositions and contents shown in Table 2 in the same manner as in Example 1, respectively.

[0078] Comparative Example 1 Comparative film 1 of Comparative Example 1 was obtained in the same manner as in Example 1, except that the polyurethane resin aqueous dispersion 1 of Production Example 1 was not included, with the composition and contents shown in Table 3.

[0079] Comparative Example 2 A film was produced in the same manner as in Example 1, except that CNF-1 was not contained, using the composition and content shown in Table 3. In Comparative Example 2, a water-containing film could not be obtained, and therefore the average film thickness, total light transmittance, haze, and adhesion tests could not be measured.

[0080] Comparative Example 3 Comparative film 3 of Comparative Example 3 was obtained in the same manner as in Example 1, except that the composition and contents shown in Table 3 were changed to CNF-2 instead of CNF-1.

[0081] Comparative Examples 4 to 6 Comparative Films 4 to 6 of Comparative Examples 4 to 6 were obtained in the same manner as in Example 1, except that the polyurethane resin aqueous dispersion 1 of Production Example 1 was changed to Comparative Production Examples 1 to 3, respectively, with the compositions and contents shown in Table 3.

[0082] The following tests were carried out on the mixed dispersions of fibrous cellulose and polyurethane resin prepared in Examples 1 to 8 and Comparative Examples 1 to 6, and the polyurethane resin-fibrous cellulose composite molded body films obtained in Examples 1 to 8 and Comparative Examples 1 and 3 to 6, and the results are shown in Tables 2 and 3.

[0083] <Test Method> [Filtrate solid content] The solid content (%) of the filtrate was calculated according to the following formula: Specifically, 20 g of the filtrate obtained during the preparation of the polyurethane resin-fibrous cellulose composite molded body was weighed out, dried in a 110°C air dryer for 4 hours, and the mass of the residue after drying was measured. Formula: Filtrate solid content (%) = [mass of residue after drying filtrate (g) / filtrate 20g] x 100

[0084] [Yield rate] The yield rate was calculated according to the following formula. Formula: Yield rate (%) = [1 - filtrate solids (%) / solids before filtration (%)] x 100 Here, the solid content (%) before filtration means the solid content contained in the mixed aqueous dispersion of fibrous cellulose and polyurethane resin prepared to produce a composite molded body of fibrous cellulose and polyurethane resin.

[0085] [Average film thickness] The average film thickness (μm) was determined by measuring three points on each of the obtained films using a digimatic micrometer manufactured by Mitutoyo Corporation and calculating the average.

[0086] [Total light transmittance and haze] The total light transmittance (%) and haze (%) were measured using a turbidity meter NDH 4000 manufactured by Nippon Denshoku Industries Co., Ltd.

[0087] [Conductive ink layer adhesion test] Each polyurethane resin-fibrous cellulose composite molded body was coated with Dotite (registered trademark) FE-107 (solvent-based conductive ink, manufactured by Fujikura Kasei Co., Ltd.) to a dry average film thickness of approximately 100 μm. Next, cellophane tape (Nichiban (registered trademark): No. 405) was applied to the coating film by rolling it back and forth four times with a 2 kg pressure rubber roller, and then peeled off horizontally. After the test, the sample was photographed and binarized using software (ImageJ) to determine the remaining area (%). The threshold for binarization was set to the software's default value, i.e., threshold = (average brightness value of the background + average brightness value of the target area) ÷ 2.

[0088] [Table 2]

[0089] [Table 3]

[0090] <Test Results> As a result, as shown in Tables 2 and 3, the polyurethane resin-fibrous cellulose composite moldings of Examples 1 to 8 had higher transparency (total light transmittance and haze value) and higher adhesion to the conductive pattern layer than Comparative Examples 1 to 6. Comparative Example 1, which contained only fibrous cellulose and no polyurethane resin, had high haze (low transparency) and poor adhesion. In Comparative Example 2, which contained only polyurethane resin and no fibrous cellulose, a film could not be produced. In Comparative Example 3, which contained fibrous cellulose with a fiber diameter of less than 10 nm, the suction filtration time was too long, and therefore a large amount of energy was required for drying. Comparative Examples 4 and 5, which used a non-anionic polyurethane resin aqueous dispersion, had higher haze (lower transparency) than Comparative Example 1. Comparative Example 6, which contained a resin other than a urethane resin (acrylic resin), had poorer adhesion than Comparative Example 1. Therefore, by using the polyurethane resin aqueous dispersions of Production Examples 1 to 8, even if they contain fibrous cellulose with an average fiber diameter of 10 nm or more, a composite molded body of polyurethane resin and fibrous cellulose could be produced by a filtration method with little energy consumption, which has high transparency and high adhesion to a conductive pattern layer. [Industrial Applicability]

[0091] The composite molded article of the present invention, which is made of a polyurethane resin and fibrous cellulose, has high transparency and high adhesion to a conductive pattern layer, and therefore can be applied to the field of electronic materials such as flexible transparent substrates.

Claims

1. An aqueous polyurethane resin dispersion used for producing a composite molded article of fibrous cellulose and a polyurethane resin, comprising: The fiber diameter of the fibrous cellulose is 10 nm or more, The polyurethane resin comprises at least It has a structure derived from a polyol, a structure derived from a polyisocyanate, and a structure derived from a polyamine, and the ionicity of the aqueous polyurethane resin dispersion is anionic. Polyurethane resin aqueous dispersion.

2. 2. The aqueous polyurethane resin dispersion according to claim 1, wherein the polyol is at least one selected from the group consisting of polycarbonate diols, polyester diols, and polyether diols.

3. The aqueous polyurethane resin dispersion according to claim 1 , wherein the polyol comprises a polycarbonate diol.

4. 2. The polyurethane resin aqueous dispersion according to claim 1, wherein the polyisocyanate comprises at least one selected from the group consisting of an aliphatic isocyanate and an alicyclic isocyanate.

5. The aqueous polyurethane resin dispersion according to claim 1 , wherein the polyurethane resin further has a structure derived from a polyalkylene glycol monoalkyl ether.

6. A polyurethane resin composition comprising the polyurethane resin aqueous dispersion according to claim 1 and fibrous cellulose, A polyurethane resin composition, wherein the fibrous cellulose has a fiber diameter of 10 nm or more.

7. A composite molded article of a polyurethane resin having at least a polyol-derived structure, a polyisocyanate-derived structure, and a polyamine-derived structure, and having an anionic ionic property, and fibrous cellulose, A composite molded body, wherein the fiber diameter of the fibrous cellulose is 10 nm or more.

8. 8. The composite molded body according to claim 7, wherein the content of the polyurethane resin is 10 to 150 parts by mass per 100 parts by mass of the fibrous cellulose.

9. A conductive circuit board having the composite molded product according to claim 7 and a conductive pattern on the surface thereof.

10. 8. A method for producing the composite molded article according to claim 7, comprising a step of obtaining a composite of water-containing fibrous cellulose and polyurethane resin by filtering the polyurethane resin composition according to claim 6.

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