JP2008007894A - Thermally solidifiable aqueous emulsion for leather-like sheet material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermally solidifiable aqueous emulsion for leather-like sheet materials hardly causing sheet deformation and contraction in a dying process of the leather-like sheet materials. <P>SOLUTION: The thermally solidifiable aqueous emulsion for leather-like sheet materials comprises a polyurethane resin (a) and an organic acid salt (b) as essential ingredients, wherein the organic acid salt (b) is preferably a 1-8C carboxylic acid salt and the thermally solidifiable aqueous emulsion for leather-like sheet materials preferably contains a nonionic surfactant (c) having 40-180°C clouding point. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heat-sensitive coagulable aqueous emulsion for a leather-like sheet material, and more particularly to a method for producing a leather-like sheet material obtained using a heat-sensitive coagulable aqueous emulsion containing a polyurethane resin and a leather-like sheet material.

Conventionally, as a method for producing a leather-like sheet material, a method of applying a polyurethane resin as a binding agent to a fiber material substrate has been performed. In recent years, as a polyurethane resin, a method of wet coagulation using an aqueous emulsion of a polyurethane resin from a conventional wet method using a polyurethane resin solution has been performed from the viewpoint of strengthening legal regulations for VOC reduction (Patent Document 1). reference). Furthermore, there has been proposed a method of thermally coagulating by applying an inorganic salt-containing polyurethane resin aqueous emulsion using a fiber material substrate previously provided with a soft water repellent (see Patent Document 2).
The methods proposed in Patent Document 1 and Patent Document 2 use an inorganic salt as a heat-sensitive coagulant, so that the inorganic salt dissolves in water during the dyeing process to form fine voids, and the presence of the voids. A soft texture like natural leather can be expressed.

JP-A-6-316877 JP 2000-17581 A

  However, when an inorganic salt is used as a heat-sensitive coagulant, there is a problem that the sheet is likely to be deformed or contracted in the dyeing process of the leather-like sheet material.

As a result of intensive studies to solve this problem, the present inventors have found that the cause of deformation and shrinkage is that the inorganic salt rapidly causes the polyurethane resin aqueous emulsion to coagulate, causing deformation and shrinkage. Estimated and reached the present invention.
That is, in the present invention, a fiber material substrate is impregnated with a heat-sensitive coagulable aqueous emulsion for leather-like sheet material containing polyurethane resin (a) and organic acid salt (b) as essential components; Thereafter, a method for producing a leather-like sheet material characterized by thermal coagulation; a leather-like sheet material obtained by the production method; and a leather-like sheet obtained by further post-processing the leather-like sheet material; It is.

  The heat-sensitive coagulable aqueous emulsion for leather-like sheet material of the present invention is excellent in the shape retention of the leather-like sheet during the dyeing process of the leather-like sheet material.

  The present invention is described in detail below.

  The heat-sensitive coagulable aqueous emulsion (A) in the present invention (hereinafter sometimes simply referred to as (A)) is a polyurethane resin (a) (hereinafter sometimes simply denoted as (a)) and organic. An acid salt (b) (hereinafter sometimes simply referred to as (b)) is contained as an essential component.

(A) which is an essential component of (A) in the present invention is, for example, an organic diisocyanate (a1), a polymer polyol (a2), a carboxyl group (—COOH) and / or a sulfone group (—SO ₃ H) -containing polyol. Or a salt thereof (a3) and, if necessary, a chain extender (a4) and / or a terminator (a5), and then, if necessary, neutralize a carboxyl group and / or a sulfone group with a neutralizing agent (a6) Is formed.
Hereinafter, each component will be described.

  As (a1), those conventionally used for polyurethane production can be used. (A1) has 6 to 20 aromatic diisocyanates, 2 to 18 aliphatic diisocyanates, 4 to 15 alicyclic diisocyanates, and carbon numbers (excluding carbon in the NCO group, the same applies hereinafter) 8-15 araliphatic diisocyanates, modified products of these diisocyanates (carbodiimide-modified products, urethane-modified products, uretdione-modified products, etc.) and mixtures of two or more of these.

  Aromatic diisocyanates include 1,3- and / or 1,4-phenylene diisocyanate, 2,4- and / or 2,6-tolylene diisocyanate (hereinafter abbreviated as TDI), 2,4′- and / or 4 , 4'-diphenylmethane diisocyanate (hereinafter abbreviated as MDI), 4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4 Examples include '-diisocyanatodiphenylmethane and 1,5-naphthylene diisocyanate.

  Aliphatic diisocyanates include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethylcaproate, bis (2- Isocyanatoethyl) carbonate, 2-isocyanatoethyl-2,6-diisocyanatohexanoate, and the like.

  Examples of the alicyclic diisocyanate include isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, bis (2-isocyanatoethyl) -4-cyclohexylene-1,2-dicarboxylate, 2,5- and / or 2,6-norbornane diisocyanate and the like.

  Examples of the araliphatic diisocyanate include m- and / or p-xylylene diisocyanate, α, α, α ′, α′-tetramethylxylylene diisocyanate, and the like.

  Of (a1), preferred are aromatic diisocyanate and alicyclic diisocyanate, and particularly preferred are isophorone diisocyanate and 4,4'-dicyclohexylmethane diisocyanate.

  Examples of the polymer polyol (a2) include polyether diol (a21), polyester diol (a22), and a mixture of two or more thereof.

  Examples of the polyether diol (a21) include compounds having a structure in which an alkylene oxide (hereinafter abbreviated as AO) is added to an active hydrogen atom-containing bifunctional compound, and mixtures of two or more thereof.

  Examples of the active hydrogen atom-containing bifunctional compound include dihydric alcohols, dihydric phenols, and dicarboxylic acids.

  Examples of the dihydric alcohol include ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, bis (hydroxymethyl) cyclohexane and bis (hydroxyethyl). ) Benzene and the like. Examples of dihydric phenols include catechol and hydroquinone, as well as bisphenols such as bisphenol A, bisphenol F, and bisphenol S. Examples of the dicarboxylic acid include aliphatic dicarboxylic acids such as succinic acid and adipic acid, and aromatic dicarboxylic acids such as phthalic acid and terephthalic acid. Two or more of the above-mentioned active hydrogen atom-containing compounds can be used.

Examples of AO added to the active hydrogen atom-containing bifunctional compound include ethylene oxide (hereinafter abbreviated as EO), propylene oxide (hereinafter abbreviated as PO), 1,2-, 2,3- or 1,3-butylene oxide. , Tetrahydrofuran (hereinafter abbreviated as THF), styrene oxide, α-olefin oxide, epichlorohydrin, and the like.
AO may be used alone or in combination of two or more. In the latter case, block addition, random addition, or a mixture of both may be used.
Among these AOs, preferred are EO alone, PO alone, THF alone, a combination of PO and EO, and a combination of PO and / or EO and THF.
The addition of AO to the active hydrogen atom-containing bifunctional compound can be carried out by a usual method, and is carried out without a catalyst or in the presence of a catalyst (an alkali catalyst, an amine catalyst or an acidic catalyst).

  Specific examples of (a21) include polyethylene glycol, polypropylene glycol and polytetramethylene glycol, and polytetramethylene glycol is preferred.

  The polyester diol (a22) includes a low-molecular diol and / or a condensed polyester diol (a221) obtained by reacting a polyether diol having a molecular weight of 1000 or less and a dicarboxylic acid, a low-molecular diol and a mixture thereof, and a lower alcohol (such as methanol). ) And a polylactone diol (a223) obtained by ring-opening polymerization of a lactone, and the like.

  Examples of the low molecular diol include the aforementioned dihydric alcohols, and examples of the polyether diol having a molecular weight of 1,000 or less include polytetramethylene ether glycol, polypropylene glycol, polyethylene glycol, and a mixture of two or more thereof. .

  Dicarboxylic acids include aliphatic dicarboxylic acids (such as succinic acid, adipic acid, azelaic acid, and sebacic acid), aromatic dicarboxylic acids (such as terephthalic acid, isophthalic acid, and phthalic acid), and ester-forming derivatives of these dicarboxylic acids. [Acid anhydride and lower alkyl (1 to 4 carbon atoms) ester and the like] and a mixture of two or more thereof; lactone includes ε-caprolactone, γ-butyrolactone, γ-valerolactone, and two or more thereof Of the mixture.

  The polyesterification reaction may be performed by a usual method, for example, a method in which a low molecular diol and / or a polyether diol having a molecular weight of 1000 or less is reacted (condensed) with a dicarboxylic acid or an ester-forming derivative thereof, or an initiator (a low molecular diol and a low molecular diol). (Or a polyether diol having a molecular weight of 1,000 or less) and a method of adding a lactone.

  (A221) includes polyethylene adipate diol, polybutylene adipate diol, polyhexamethylene adipate diol, polyneopentylene adipate diol, polyethylene propylene adipate diol, polyethylene butylene adipate diol, polybutylene hexamethylene adipate diol and poly (polytetramethylene) Ether) adipate condensation polyester diol such as adipate diol; azelate condensation polyester diol such as polyethylene azelate diol and polybutylene azelate diol; and sebacate condensation polyester diol such as polyethylene sebacate diol and polybutylene sebacate diol .

  As (a222), C4-10 linear alkylene carbonate diol (for example, polytetramethylene carbonate diol, polyhexamethylene carbonate diol, polycarbonate diol of nonanediol, etc.), C4-10 branched alkylene carbonate diol (for example, Polycarbonate diol of 2-methylbutanediol, polycarbonate diol of 2-ethylbutanediol, polycarbonate diol of neopentyl glycol, polycarbonate diol of 2-methylpentanediol, polycarbonate diol of 3-methylpentanediol, etc.) Coalescence is mentioned.

  Examples of (a223) include [polycaprolactone diol and the like].

  Of the (a2), preferably from the viewpoint of hydrolysis resistance and durability, polycarbonate diol (a222), more preferably polytetramethylene carbonate diol, polyhexamethylene carbonate diol, polycarbonate diol of 3-methylpentane diol and / or These are copolymers.

  The lower limit of the number average molecular weight (hereinafter abbreviated as Mn) of (a2) is preferably 500, more preferably 1,000, and the upper limit is preferably 20,000, more preferably 10,000, particularly preferably 3. , 000.

  Mn of (a2) is determined from the hydroxyl value, and the hydroxyl value can be measured by the method defined in JIS-K0070-1992 (potentiometric titration method).

  The carboxyl group and / or sulfone group-containing polyol or salt (a3) is a component used for introducing a carboxylate group or a sulfonate group for the purpose of self-emulsifying the polyurethane resin in water.

As (a3), a carboxyl group-containing polyol (a31) [dialkylol alkanoic acid {having 6 to 24 carbon atoms, such as 2,2-dimethylolpropionic acid (hereinafter abbreviated as DMPA), 2,2-dialkyl Methylol butanoic acid, 2,2-dimethylol heptanoic acid, 2,2-dimethylol octanoic acid, etc.]], and sulfone group-containing polyol (a32) [sulfonic acid diol {3- (2,3-dihydroxypropoxy) -1 -Propanesulfonic acid and the like} and sulfamic acid diol {N, N-bis (2-hydroxyalkyl) sulfamic acid and its AO adduct}.
Examples of the salt in (a3) include ammonium salts and amine salts [primary amines having 1 to 12 carbon atoms (primary monoamines such as methylamine, ethylamine, propylamine and octylamine) salts, secondary monoamines (dimethylamine, Diethylamine and dibutylamine) salts, tertiary monoamines (trimethylamine, triethylamine, triethanolamine, N-methyldiethanolamine and aliphatic tertiary monoamines such as N, N-dimethylethanolamine; N-methylpiperidine and N-methylmorpholine, etc. Heterocyclic tertiary monoamines; benzyldimethylamine, α-methylbenzyldimethylamine; and aromatic ring-containing tertiary monoamines such as N-dimethylaniline) salts], alkali metals (sodium, potassium and lithium cations Salts, and combinations of two or more thereof.
Among the salts, preferred are amine salts, more preferred are aliphatic tertiary monoamine salts, and particularly preferred are triethylamine salts.

  As the extender (a4), diamines having 2 to 10 carbon atoms (for example, ethylenediamine, propylenediamine, hexamethylenediamine, isophoronediamine, and toluenediamine); polyamines (for example, diethylenetriamine, triethylenetetramine, etc.); hydrazine or derivatives thereof (Dibasic acid dihydrazides such as adipic acid dihydrazide); polyhydric alcohols having 2 to 15 carbon atoms [the above-mentioned dihydric alcohols, trihydric alcohols (eg glycerin, trimethylolpropane, etc.), EO of these polyhydric alcohols and / Or PO low molar adduct (molecular weight less than 500)]. Of these, ethylenediamine and isophoronediamine are preferred.

  As the terminator (a5), monoalcohols having 1 to 8 carbon atoms (methanol, ethanol, isopropanol, butanol, cellosolves and carbitols), monoamines having 1 to 10 carbon atoms (monomethylamine, monoethylamine, monobutylamine) , Dibutylamine, monooctylamine, monoethanolamine and diethanolamine). Of these, monoethylamine, monobutylamine and monoethanolamine are preferred.

When (a3) is not a salt and is a carboxyl group and / or sulfone group-containing polyol, the carboxyl group and / or sulfone group is neutralized using (a6) to form a carboxylate group and / or a sulfonate group. can do.
Examples of (a6) include alkaline compounds that form the above-mentioned cations as counterions, such as ammonia, amines [primary amines having 1 to 12 carbon atoms (primary monoamines such as methylamine, ethylamine, propylamine). And octylamine), secondary monoamines (dimethylamine, diethylamine and dibutylamine), tertiary monoamines (aliphatic tertiary monoamines such as trimethylamine, triethylamine, triethanolamine, N-methyldiethanolamine and N, N-dimethylethanolamine; N -Heterocyclic tertiary monoamines such as methylpiperidine and N-methylmorpholine; benzyldimethylamine, α-methylbenzyldimethylamine; and aromatic ring-containing tertiary monoamines such as N-dimethylaniline)], alkali Genus (sodium, potassium and lithium cations), and alkali metal hydroxides, and combinations of two or more of these. Of these, preferred are amines, more preferred are aliphatic tertiary monoamines, and particularly preferred is triethylamine.

  The amount of (a6) used in the neutralization is usually 20 to 200 mol%, preferably 30 to 150 mol%, based on the total of carboxyl groups and sulfone groups. When the amount of (a6) used is 30 mol% or more, it is preferable from the viewpoint of storage stability of the aqueous dispersion, and when it is 150 mol% or less, it is preferable from the viewpoint of the viscosity of the aqueous dispersion.

(A) in the present invention contains a carboxylate group and / or a sulfonate group based on the weight of the polyurethane resin, usually 0.01% or more, preferably 0.05% or more, more preferably 0.08% or more. The content is usually 1.5% or less, preferably 0.75% or less, more preferably 0.50% or less. If the content of the carboxylate group and / or sulfonate group is less than 0.01%, stable (A) cannot be obtained, and if it exceeds 1.5%, the water resistance of the formed resin film tends to decrease.
The content of the carboxylate group and sulfonate group in (a) was determined by washing the residue obtained by heating and drying 3 to 10 g of (A) at 130 ° C. for 45 minutes, followed by washing and drying again at 130 ° C. for 45 minutes. It can be calculated from the acid value dissolved in formamide and measured by the method described in JIS-K0070 (potentiometric titration method).

The production of (a) in the present invention includes the following two methods.
(1) A prepolymer of a terminal isocyanate group (hereinafter abbreviated as a terminal NCO group urethane prepolymer) is produced in advance, and a dispersion medium and, if necessary, an emulsifier (a7), a chain extender and / or a terminator. The method obtained by emulsifying in the presence of, for example, (a) in the form of an emulsion.
(2) A method in which a polyurethane resin having a terminal hydroxyl group is produced and obtained in the form of an emulsion (a) in the presence of a dispersion medium and, if necessary, an emulsifier (a7).
Among these, the method (1) is preferable.

The terminal NCO group urethane prepolymer in the method of (1) is in the presence or absence of an organic solvent (acetone, methyl ethyl ketone, tetrahydrofuran, N, N-dimethylformamide, etc.) that does not contain an active hydrogen-containing group in the molecule. The organic diisocyanate (a1), the polymer polyol (a2) and the active hydrogen component comprising a carboxyl group and / or sulfone group-containing polyol or salt thereof (a3) have an (NCO / hydroxyl group) equivalent ratio of usually 1.05. In the range of ~ 2.0, preferably 1.1 to 1.6, usually by reaction at 20 ° C to 150 ° C, preferably 60 ° C to 110 ° C by the one-shot method or multistage method, and then in (a6) It is obtained by adding.
Examples of the dispersion medium necessary for the production of the emulsion usually include water and a hydrophilic organic solvent. The hydrophilic organic solvent has a solubility in water of 30/100 g water, for example, monovalent. Examples include alcohols (methanol, ethanol, isopropanol, etc.), glycols (ethylene glycol, propylene glycol, diethylene glycol, etc.), trivalent or higher alcohols (glycerin, etc.), and cellosolves (methyl, ethyl cellosolve, etc.). Of the dispersion media, preferred is water. When a hydrophilic organic solvent is used in combination, the hydrophilic organic solvent is usually preferably 10% or less based on the total dispersion medium.
In the emulsion of the method (2), the polyurethane resin (a) can be prepared in the presence or absence of an organic solvent containing no active hydrogen-containing group in the molecule (a1), (a2) and (a3). And an active hydrogen component having an (NCO / hydroxyl group) equivalent ratio in the range of 0.5 to 0.99 to form a urethane polymer having a terminal hydroxyl group, which is a (a6) Obtained by neutralization with

Examples of the emulsifier (a7) that can be used in the above methods (1) and (2) include a nonionic surfactant (c) having a cloud point of 40 to 180 ° C., and other nonionic surfactants (described later). a71), anionic surfactant (a72), cationic surfactant (a73) and amphoteric surfactant (a74), and polymeric emulsifying dispersant (a75), such as US Pat. No. 3,929,678 and US The thing of patent 4331447 specification is mentioned. Two or more of these can be used in combination.
Among (a7), the nonionic surfactant (c) described later is preferable from the viewpoint of temperature-sensitive coagulation.

(A71) is a nonionic interface that does not have a cloud point or has a cloud point of less than 40 ° C. or more than 180 ° C. among alkylene oxide addition type nonionic surfactants and polyhydric alcohol type nonionic surfactants. An activator is mentioned.
(A71) As the alkylene oxide addition type, aliphatic alcohol EO and adduct, phenol EO adduct, nonylphenol EO adduct, alkyl (C8-22) amine EO adduct, polypropylene glycol EO adduct, etc. Nonionic surfactants that do not have a cloud point or have a cloud point of less than 40 ° C. or greater than 180 ° C. include polyhydric (3 to 8 or more) alcohols (carbon Number 2 to 30) fatty acid (carbon number 8 to 24) ester (for example, glycerin monostearate, glycerin monooleate, sorbitan monolaurate and sorbitan monooleate), alkyl (carbon number 4 to 24) poly (polymerization) Degrees 1 to 10) include glycosides.

  As (a72), an ether carboxylic acid having a hydrocarbon group having 8 to 24 carbon atoms (hereinafter abbreviated as C8 to 24) or a salt thereof [sodium lauryl ether acetate, (poly) oxyethylene (added mole number) 1 to 100) sodium lauryl ether acetate and the like; sulfates or ether sulfates having a C8-24 hydrocarbon group and salts thereof [sodium lauryl sulfate, (poly) oxyethylene (addition mole number 1 to 100) lauryl sulfate Sodium, (poly) oxyethylene (addition mole number 1-100) lauryl sulfate triethanolamine, (poly) oxyethylene (addition mole number 1-100) coconut oil fatty acid monoethanolamide sodium sulfate, etc.]; carbonization of C8-24 Sulfonates having hydrogen groups [Dodecylbenzenesulfone Sodium etc.]; sulfosuccinate having one or two C8-24 hydrocarbon groups; phosphate ester or ether phosphate ester having C8-24 hydrocarbon groups and salts thereof [sodium lauryl phosphate, ( Poly) oxyethylene (addition mole number 1 to 100) sodium lauryl ether phosphate, etc.]; fatty acid salt having C8-24 hydrocarbon group [sodium laurate, triethanolamine laurate, etc.]; and carbonization of C8-24 Acylated amino acid salts having a hydrogen group [coconut oil fatty acid methyl taurine sodium, coconut oil fatty acid sarcosine sodium, coconut oil fatty acid sarcosine triethanolamine, N-coconut oil fatty acid acyl-L-glutamic acid triethanolamine, N-coconut oil fatty acid acyl -Sodium L-glutamate Lauroyl methyl -β- sodium alanine, etc.] and the like.

  (A73) includes quaternary ammonium salt type [stearyl trimethyl ammonium chloride, behenyl trimethyl ammonium chloride, distearyl dimethyl ammonium chloride, ethyl lanolin sulfate fatty acid aminopropylethyl dimethyl ammonium, etc.]; and amine salt type [diethylaminoethyl stearate] Amide lactate, dilaurylamine hydrochloride, oleylamine lactate, etc.].

  (A74) is a betaine-type amphoteric surfactant [coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, lauryldimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, laurylhydroxysulfo Betaine, lauroylamidoethylhydroxyethylcarboxymethylbetaine sodium hydroxypropyl phosphate and the like]; and amino acid type amphoteric surfactants [sodium β-laurylaminopropionate and the like].

  As (a75), polyvinyl alcohol, starch and derivatives thereof, cellulose derivatives such as carboxymethylcellulose, methylcellulose, and hydroxyethylcellulose, carboxyl group-containing (co) polymers such as polyacrylic acid soda, and Mn = 1,000 to 50,000 And a polymer type dispersant having a urethane bond or an ester bond described in US Pat. No. 5,906,704 and the like [for example, a polycaprolactone polyol and a polyether diol linked with a polyisocyanate].

  In the urethanization reaction for obtaining (a) in the present invention, a catalyst used in a normal urethanization reaction may be used as necessary in order to accelerate the reaction. Catalysts include amine catalysts such as triethylamine, N-ethylmorpholine, triethylenediamine and cycloamidines described in US Pat. No. 4,524,104 [1,8-diaza-bicyclo (5,4,0) undecene-7. (San Apro Co., Ltd., DBU) and the like]; tin-based catalysts such as dibutyltin dilaurate, dioctyltin dilaurate and tin octylate; titanium-based catalysts such as tetrabutyl titanate and the like.

  Mn in (a) can be measured by gel permeation chromatography (hereinafter abbreviated as GPC). In the case of the non-crosslinked type (thermoplastic) (a), it is usually 2,000 to 2,000,000 or more, preferably 10,000 to 1,500,000, especially 100,000 to 500,000. . The cross-linking type (a) may have a Mn higher than the above range or a high Mn that cannot be measured by GPC.

The organic acid salt (b), which is an essential component of the heat-sensitive coagulable aqueous emulsion (A), has a function of coagulating the emulsion, and examples thereof include the following.

(B1) Monovalent or polyvalent carboxylate Monovalent carboxylate having 1 to 18 carbon atoms, such as formate, acetate, lactate, glycolate, butyrate, caprylate, 2-ethylhexanoate , Nonanoate and dodecanoate and the like, and divalent to pentavalent carboxylates such as oxalate, adipate, citrate, itaconate, phthalate and trimellitic acid salt,
(B2) Sulfonate A sulfonate having an alkyl group having 1 to 18 carbon atoms, for example, an alkyl-substituted aromatic sulfonate having an alkyl group having 1 to 18 carbon atoms such as methyl sulfonate and ethyl sulfonate, For example, p-toluenesulfonate and dodecylbenzenesulfonate, naphthalenesulfonate and p-phenolsulfonate,
(B3) Sulfate ester sulfate ester salt having an alkyl or alkenyl group having 1 to 12 carbon atoms, such as octyl sulfate ester salt, 2-ethylhexyl sulfate ester salt, decyl sulfate ester salt and dodecyl sulfate ester salt,
(B4) Phosphate salt Phosphate salt having an alkyl or alkenyl group having 1 to 12 carbon atoms, such as octyl phosphate salt, 2-ethylhexyl phosphate ester salt, decyl phosphate ester salt and dodecyl phosphate ester salt,
(B5) Phenol salts such as phenol salts, p-chlorophenol salts, β-naphthol salts, o- and p-nitrophenol salts, p-aminophenol salts, catechol salts and resorcin salts.

In (b), examples of the salt include alkali metal salts, alkaline earth metal salts, ammonium salts, amine salts, and quaternary ammonium salts.
Among these salts, examples of the alkali metal salt and amine salt include the same salts as those described above as the salt of (a3).
Examples of alkaline earth metal salts include calcium, magnesium, barium and strontium salts.
Examples of the quaternary ammonium salt include tetraalkylammonium salts having an alkyl group having 1 to 8 carbon atoms such as tetramethylammonium, tetraethylammonium, and dimethyldiethylammonium salt.

Among (b), from the viewpoint of solubility in water during the dyeing step, (b1) is preferred, and more preferred are monovalent carboxylates, especially acetates, especially alkali metal salts and alkaline earths thereof. It is a metal salt.

The heat-sensitive coagulable aqueous emulsion of the present invention contains an organic acid salt (b), so that the urethane resin film obtained by coagulation has fewer irregularities than the emulsion containing an inorganic salt, and has excellent film-forming properties. Excellent film strength. Therefore, deformation and contraction of the sheet are less likely to occur in the dyeing process.
The coagulation of the emulsion with the salt is considered to be caused by the salting out of the emulsion particles and the salt through the hydration water.
And it is estimated that coagulation occurs more gently as the salting-out power is weaker, and as a result, the film-forming property of the resin is improved.
The salting-out power is indicated by the absolute value of the hydration enthalpy of each salt, but since the organic acid salt (b) has a smaller absolute value than the inorganic salt, the salting-out power is weak and the film forming property is increased. It is estimated that

The content of (a) in the heat-sensitive coagulable aqueous emulsion (A) of the present invention is preferably 2 to 40% by weight, more preferably 3 to 30% (hereinafter, unless otherwise specified,% represents% by weight). The content of (b) is preferably 0.05 to 15%, more preferably 0.5 to 10%, and the other components are aqueous media.
The total of (a) and (b) in (A) is preferably 2.3 to 65%, more preferably 3.5 to 42%.

A nonionic surfactant (c) having a cloud point may be used for the heat-sensitive coagulable aqueous emulsion (A) in the present invention, and any nonionic surfactant having a cloud point is not particularly limited, but is preferable. Is a polyethylene glycol type nonionic surfactant having a cloud point of preferably 40 to 180 ° C, more preferably 42 to 80 ° C. When the cloud point of (c) is less than 40 ° C., there is a problem in storage stability such as generation of a solidified product when (A) is stored for a long time. On the other hand, if the cloud point exceeds 180 ° C., the affinity of polyurethane for water becomes too high, and (A) becomes difficult to thermally coagulate.
The cloud point can be measured by heating a 2% aqueous solution of a nonionic surfactant with stirring and reading the temperature at which it becomes cloudy. An active agent having a cloud point exceeding 100 ° C. can be measured by “Thermo System FP-900” manufactured by Yamato Scientific Co., Ltd.
(C) may be used as an emulsifier during the production of the emulsion of the above-mentioned (a) or the soft water repellent (d) described later, or may be newly added and blended after the production of the emulsion.

  Specific examples of (c) include aliphatic alcohol EO and adduct [oleyl alcohol EO 11 to 16 mol adduct (cloud point 78 to 93 ° C.), lauryl alcohol EO 8 to 11 mol adduct (cloud point 70 to 98 ° C.). Etc.]; alkyl (C8-22) phenol EO adduct [octylphenol EO 9.5 to 14 mol adduct (cloud point 65 to 94) and nonylphenol EO 10 to 15 mol adduct (cloud point 64 to 96 ° C.) and the like]; alkyl (C8-22) amine EO adducts; and polypropylene glycol EO adducts [polypropylene glycol (Mn = 700) EO 20-30 mol adducts, etc.], and these EO adducts are small amounts (30 mol% or less). It may be a random or block adduct with PO.

  The lower limit of HLB in (c) is preferably 10, more preferably 11, particularly preferably 12, and the upper limit is preferably 17, more preferably 16, and particularly preferably 15. When the HLB of (b) is 10 or more, even when the emulsion is stored for a long period of time, a solidified product is not generated and a problem in storage stability hardly occurs. On the other hand, if the HLB is 17 or less, it is preferable because the emulsion easily heat-coagulates when heated.

HLB in the present invention is a value calculated by the following Griffin method described in Takehiko Fujimoto, “Introduction to New Surfactant”, published by Sanyo Chemical Industries, Ltd. (1992), P128.
HLB = (weight% of hydrophilic group) × (1/5)

Examples of the commercially available product (c) include the following aliphatic alcohol EO adducts.
“Emalmin NL-70”; cloud point = 44 ° C., HLB = 12.4, manufactured by Sanyo Chemical Industries “Emalmine 110”; cloud point = 56 ° C., HLB = 13.2, manufactured by Sanyo Chemical Industries Co., Ltd. “Narrow Acty-N120”; cloud point = 77 ° C., HLB = 14.3, manufactured by Sanyo Chemical Industries “Emalmin 140”; cloud point = 80 ° C., HLB = 14.2, manufactured by Sanyo Chemical Industries

  The nonwoven fabric impregnated with the heat-sensitive coagulable water-based emulsion (A) is usually one that has not been treated with a soft water repellent from the viewpoint of process reduction. In the present invention, the soft water repellent (d) is heat-coagulated. May be added to the water-based aqueous emulsion (A). Although it will not specifically limit if it is a compound conventionally used as a flexible water repellent, For example, a silicone (d1), a fluorine atom containing organic compound (d2), etc. are mentioned.

Examples of (d1) include polysiloxane and modified silicone oil.
Examples of the polysiloxane include dimethylpolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane, and diorganopolysiloxane diol. Modified silicone oils include epoxy-modified silicone oil, alkyl-modified silicone oil, and alkylaralkyl-modified silicone oil. Amino-modified silicone oil, carboxyl-modified silicone oil, alcohol-modified silicone oil, fluorine-modified silicone oil, and polyether-modified silicone oil.

Examples of (d2) include fluoroalkyl ester polymers of acrylic acid (for example, 1,1-dihydroperfluorooctyl acrylate polymer, perfluoroalkylethyl acrylate-alkyl acrylate copolymer, etc.).
Of these, preferred is (d1), and more preferred are polysiloxanes, particularly dimethylpolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane, and combinations thereof.
(D) may be in the form of silicone or fluorine atom-containing organic compound itself, but may be in the form of an emulsion emulsified and dispersed in an aqueous medium. From the viewpoint of ease of addition, the form of an emulsion is preferable.
Examples of the emulsifier that can be used in the emulsion of (d) include the same emulsifiers as mentioned in the preparation of the emulsion of (a).
Emulsion type (d) commercial products include “SM8706” [manufactured by Toray Dow Corning Co., Ltd., active ingredient 35%], “KM797” [manufactured by Shin-Etsu Chemical Co., Ltd., active ingredient 38%], and “ Dickguard F-90N ”[manufactured by Dainippon Ink & Chemicals, Inc., 20% active ingredient].

The method for preparing the heat-sensitive coagulable aqueous emulsion (A) of the present invention is not particularly limited, but from the viewpoint of storage stability, a method of adding (b) to the emulsion composed of (a), (c) and (d). preferable.
The following method is mentioned as a method of adjusting the emulsion consisting of (a), (c) and (d).
(1) A method of adding the emulsion of (d) to the emulsion of (a) after adding the activator of (c).
(2); (c) and, if necessary, (a7) are mixed with one or more of the terminal hydroxyl group polyurethane resin, the terminal NCO group urethane prepolymer or the dispersion medium, and these are emulsified in the dispersion medium. A method of adding the emulsion of d).
(3): A method of mixing (c) and (a7) if necessary with either a terminal hydroxyl group polyurethane resin or a terminal NCO group prepolymer, and dispersing and emulsifying this in the emulsion of (d).
(4): A method in which (d) is mixed with either a terminal hydroxyl group polyurethane resin or a terminal NCO group prepolymer, or (c) is mixed with either or both of a dispersion medium and these are emulsified.
(5): A method of emulsifying a terminal hydroxyl group polyurethane resin or a terminal NCO group prepolymer in the emulsion of (d) using (c) as an emulsifier.
Among these, the method (2) is preferable from the viewpoint of the storage stability of (A). As a method for adding the organic group-containing acid salt (b), a method of synthesizing in an emulsion composed of (a), (c) and (d) is also possible. For example, (b) is synthesized by adding an organic group-containing acid and an alkali metal and / or alkaline earth metal hydroxide to an emulsion composed of (a), (c) and (d) and causing a neutralization reaction. However, a leather-like sheet material can also be produced. However, from the viewpoint of destabilization of emulsion particles due to heat of neutralization, a method of adding an aqueous solution of an organic group-containing acid salt (b) prepared in advance to an emulsion composed of (a), (c) and (d) is preferable. .

  The apparatus that can be used in the mixing / emulsification step in the present invention is not particularly limited, and examples thereof include an emulsifier of the following method: 1) vertical stirring method, 2) rotor-stator method [for example, “Ebara Milder” “(Made by Ebara Seisakusho)”, 3) Line mill method [for example, line flow mixer], 4) Static tube mixing type [for example, static mixer], 5) Vibration type [for example, “VIBRO MIXER” (manufactured by Chilling Industries Co., Ltd.)], 6) Ultrasonic impact type [eg ultrasonic homogenizer], 7) High pressure impact type [eg Gaulin homogenizer (Gaurin)], 8) Membrane emulsification type [eg membrane emulsification module], and 9) Centrifugal thin film contact type [eg fill mix]. Of these, 1), 2) and 9) are preferred.

The thermal coagulation temperature (A) in the present invention is preferably 40 to 180 ° C, more preferably 40 to 90 ° C. If it is less than 40 ° C., it is not preferable from the viewpoint of storage stability, and if it exceeds 180 ° C., it is difficult to solidify, which is not preferable.
The heat-sensitive coagulation temperature can be measured by heating the emulsion and reading the temperature at which the coagulation flow stops using a thermometer.
Specifically, 3 ml of emulsion is put into a glass sample bottle, heated in an oil bath at a rate of 1 ° C./second, and read with a thermometer.
The volume average particle diameter of (A) in the present invention is preferably 0.01 μm to 1 μm. More preferably, it is 0.02 micrometer-0.5 micrometer. The average particle diameter can be measured using an ELS-800 electrophoretic light scattering photometer manufactured by Otsuka Electronics Co., Ltd.

  The breaking strength of the film obtained by leaving (A) in the present invention at room temperature (25 ° C.) for 24 hours and further drying at 105 ° C. for 3 hours is preferably 10 to 100 MPa, more preferably 20 to 60 MPa. In addition, you may use a film-forming auxiliary | assistance for preparation of a film as needed.

The breaking strength can be measured by the following method.
The film obtained with the No. 3 dumbbell cutter was cut into a test piece, and this was measured for tensile strength at a tensile speed of 300 mm / min} using an autograph {AGS-500D, manufactured by Shimadzu Corporation}. This test is carried out under conditions of a temperature of 25 ° C. and a relative humidity of 65% RH, and it is necessary to adjust the temperature of the test sample under the same conditions for 2 hours or more before the measurement.

   In the present invention (A), if necessary, a colorant such as titanium oxide, an ultraviolet absorber (benzophenone series, benzotriazole series, etc.) or an antioxidant [4,4′-butylidene-bis (3-methyl-6-1). -Stabilizers such as hindered phenols such as butylphenol; organic phosphites such as triphenyl phosphite and trichloroethyl phosphite], preservatives, crosslinking agents (polyepoxy compounds, polyisocyanate compounds, etc.), inorganic fillers (Such as calcium carbonate) can be added. The total amount of these additives is preferably 5 parts by weight or less based on the weight of (A). More preferably, it is 0.1 to 3 parts by weight.

  The method for producing a leather-like sheet material of the present invention is characterized in that a fiber material substrate is impregnated with the above heat-sensitive coagulable aqueous emulsion and then heat-coagulated.

As the fiber material substrate used in the present invention, a nonwoven fabric or a knitted fabric conventionally used for a fiber material substrate is used.
The nonwoven fabric may be one in which a woven fabric or the like is laminated inside or on the surface for the purpose of reinforcement or the like. Constituent fibers may be natural fibers or chemical fibers. Natural fibers include cotton, wool, silk, asbestos, etc. Chemical fibers include regenerated fibers such as rayon and tencel, semi-synthetic fibers such as acetate and triacetate, polyamides. , Synthetic fibers such as polyester, polyolefin, and acrylic. Moreover, it is also possible to use appropriately a fiber using a mixture of these.

Application of (A) to the fibrous material substrate in the present invention is performed by impregnation or coating, and any method can be used as long as it is a commonly performed method.
For example, a method of impregnating (A) on a fiber material substrate and squeezing with a mangle or the like to prepare a pickup, and other methods such as knife coating, air knife coating, roll coating and spray coating can be mentioned.
Examples of the coagulation and drying method (A) applied to the substrate include (1) a method in which heated steam is blown to heat-coagulate and then heat-drying or air-drying using a drying device, and (2) in the drying device. For example, a method of introducing it as it is, solidifying by heating and drying it can be mentioned.
Among these, the method (1) is preferable.

  The temperature (° C.) of the atmosphere for solidifying (A) applied to the substrate is preferably 40 to 180 ° C., more preferably from the viewpoint of quickly completing the coagulation bath and coagulation of the polyurethane resin. 60-150 degreeC, Most preferably, it is 70-120 degreeC. The time for heat-sensitive coagulation varies depending on the temperature, but is usually 0.1 minutes to 30 minutes, preferably 0.5 minutes to 20 minutes.

  The drying temperature after solidification is usually 100 to 200 ° C, preferably 120 to 180 ° C, and the time is usually 1 to 60 minutes, preferably 2 to 30 minutes.

  The leather-like sheet material of the present invention is obtained by the above production method, and the weight of the polyurethane resin (a) attached to the fiber material substrate is preferably 3 parts by weight or more with respect to 100 parts by weight of the fiber material substrate. More preferably, it is 10 parts by weight or more, particularly preferably 20 parts by weight or more, preferably 150 parts by weight or less, more preferably 100 parts by weight or less, particularly preferably 50 parts by weight or less.

  The leather-like sheet of the present invention is obtained by subjecting the leather-like sheet material obtained as described above to further post-processing treatment such as dyeing, washing, grinding and / or drying.

  The leather-like sheet material of the present invention provides a leather-like sheet having excellent shape retention performance during the dyeing process, and is similar to natural leather having good wear resistance and texture by using a flexible water repellent. Can be manufactured. The leather-like sheet of the present invention can be suitably used for various applications, for example, mattresses, lining materials, clothing, shoe core materials, cushions, automobile interior materials, wall materials, and the like.

<Example>
EXAMPLES Hereinafter, although an Example demonstrates this invention further, this invention is not limited to this. In the following, “parts” indicates parts by weight.

<Production of polyurethane resin (a) emulsion>
Production Example 1
In a closed reaction vessel equipped with a thermometer and a stirrer, 330 parts of polyhexamethylene carbonate diol of Mn2,000, 6.5 parts of α, α-dimethylolpropionic acid (DMPA), 98 parts of 4,4′-dicyclohexylmethane diisocyanate and After adding 235 parts of acetone and replacing the reaction system with nitrogen gas, the mixture was reacted at 90 ° C. for 10 hours with stirring to obtain an acetone solution of a terminal NCO-based urethane prepolymer. The obtained acetone solution was cooled to 40 ° C. and 5.0 parts of triethylamine was added. Next, as (c), “Naroacti N-120” (manufactured by Sanyo Chemical Industries, Ltd., HLB 14.2, cloud point 77 ° C.) 21.7 parts dissolved in 412 parts of water was added to the acetone solution. After stirring and emulsifying with a homomixer for 1 minute, a solution obtained by dissolving 1.0 part of ethylenediamine in 230 parts of water was added to cause a chain elongation reaction, then acetone was distilled off under reduced pressure, and the concentration was adjusted with water. As a result, a polyurethane resin emulsion-1 having a nonvolatile residue of 40% and an average dispersed particle size of 0.5 μm was obtained.
The content rate of the carboxylate group based on the weight of (a) in the obtained polyurethane resin emulsion-1 was 0.51%.

Production Example 2
Production Example, except that instead of polyhexamethylene carbonate diol having a number average molecular weight of 2,000, 3-methyl-1,5-pentanediol / 1,6-hexanediol copolymer polycarbonate diol having an Mn of 2,000 is used. 1 to obtain a polyurethane resin emulsion-2.
The content rate of the carboxylate group based on the weight of (a) in the obtained polyurethane resin emulsion-2 was 0.50%.

<Manufacture of non-woven fabric>
A laminated sheet is made from polyethylene terephthalate short fibers, this sheet is needle punched so that the number of shots is 280 pieces / cm ² , and then dried, and a nonwoven fabric having a weight of 380 g / m ² and an apparent density of 0.18 g / cm ² (About 100 cm × about 300 cm × thickness about 1.0 mm) was obtained.

Example 1
The present invention is prepared by adding 16 parts of a 20% aqueous solution of calcium acetate as an organic acid salt (b) to 100 parts of the polyurethane resin emulsion-1 and adding water so that the non-volatile residue is 20%. A heat-sensitive coagulable emulsion was obtained. The emulsion is impregnated with a nonwoven fabric, squeezed with mangles so that the adhesion rate of the resin is about 30% with respect to the weight of the nonwoven fabric, heated in saturated steam at 100 ° C. for 2 minutes, and then a hot air dryer at 120 ° C. After drying for 20 minutes, it was washed with water, and again dried with a hot air dryer at 120 ° C. for 20 minutes to obtain a leather-like sheet material.

Example 2
A leather-like sheet material was prepared in the same manner as in Example 1 except that 3 parts of emulsion type silicone “SM8706” [manufactured by Toray Dow Corning Co., Ltd.] was further added to the heat-sensitive coagulable aqueous emulsion as the soft water repellent (d). Obtained.

Example 3
A leather-like sheet material was obtained in the same manner as in Example 1 except that polyurethane resin-2 was used and “SM8706” was further added as a soft water repellent (d) to the heat-sensitive coagulable aqueous emulsion.

Example 4
As in Example 1, except that 80 parts of a 10% aqueous solution of sodium acetate was added as the organic acid salt (b), and “SM8706” was further added to the heat-sensitive coagulable aqueous emulsion as the soft water repellent (d). A leather-like sheet material was obtained.

Comparative Example 1
A leather-like sheet material was obtained in the same manner as in Example 1 except that the organic acid salt (b) was not added.

Comparative Example 2
A leather-like sheet material was obtained in the same manner as in Example 1 except that the organic acid salt (b) was not added and “SM8706” was added as the soft water repellent (d).

Comparative Example 3
A leather-like sheet material was obtained in the same manner as in Example 1 except that 8 parts of a 5% calcium chloride aqueous solution was added as an inorganic salt.

The components of the heat-sensitive coagulable emulsion and the heat-sensitive gelation temperature used in Examples 1 to 4 and Comparative Examples 1 to 3 are shown in Tables 1 and 2.
The thermal coagulation temperature is measured by placing 3 ml of the emulsion in a glass sample bottle, heating it in an oil bath at a rate of 1 ° C / second, and reading it with a thermometer of 0 to 100 ° C with a minimum scale of 0.1 ° C. It was.

<Performance test>
For the leather-like sheet materials produced in Examples and Comparative Examples, the resin adhesion rate (% by weight), resin migration (uneven distribution), texture, and shape retention rate of the leather-like sheet material were evaluated by the following evaluation methods. The results are shown in Tables 1 and 2.
[Adhesion rate of resin (wt%)]
It was calculated by the following formula.
100 × [(weight of leather-like sheet material) − (weight of fiber material substrate)] / (weight of fiber material substrate)
[Migration of resin]
The cross sections of the leather-like sheets prepared in Examples 1 to 4 and Comparative Examples 1 to 3 were observed with an electron microscope (Hitachi, S-800), and the surface portion and the central portion of the polyurethane resin adhered to the fiber material substrate. The polyurethane resin is uniformly distributed in the fiber material base, and the resin having no uneven distribution is judged as “◯”, and the resin is unevenly distributed on the surface portion of the fiber material base as “×” Was determined.
[Texture]
If the leather-like sheet material has a natural leather-like texture, it will be judged as “○”, and if it is slightly inferior in comparison with natural leather, “△”. The case where no texture was exhibited was determined as “x”.
Judgment was made by a sensory test based on the hand touch.
[Shape retention of leather-like sheet material]
The leather-like sheet materials obtained in the above examples and comparative examples were cut into a size of 10 cm in length and 10 cm in width, and the length of the center portion in the vertical direction (H ₀ ) and the length of the center portion in the horizontal method (L ₀ ) was measured with a vernier caliper to a minimum scale of 0.1 mm, and the fluid-like dyeing test (dye: Miketon Poly. Yellow GSL manufactured by Sakai Obex Co., Ltd., temperature: 120 ° C., flow rate: 200- 300L / min, dyeing test machine name: Wins dyeing machine, manufacturer: manufactured by Tecsum Giken Co., Ltd.), length of center part in the vertical direction (H ₁ ) after drying at 120 ° C. for 20 minutes, and center of the horizontal method The length (L ₁ ) of the part was measured. The average shape retention rate (%) in the vertical and horizontal directions was calculated using the following formula.
Shape retention rate (%) = [(H ₁ / H ₀ ) × 100 + (L ₁ / L ₀ ) × 100] / 2

  The leather-like sheet material and leather-like sheet obtained by the production method of the present invention are useful for mattresses, lining materials, clothing, shoe core materials, cushions, automobile interior materials, wall materials, and the like.

Claims (10)

  A heat-sensitive coagulable aqueous emulsion for a leather-like sheet material comprising a polyurethane resin (a) and an organic acid salt (b) as essential components.   The heat-sensitive coagulable aqueous emulsion according to claim 1, further comprising a nonionic surfactant (c) having a cloud point.   The heat-sensitive coagulation property according to claim 1 or 2, wherein the polyurethane resin (a) is a polyurethane resin containing 0.01 to 1.5% by weight of a carboxylate group and / or a sulfonate group based on the weight of the (a). Aqueous emulsion.   The heat-sensitive coagulation according to claim 2 or 3, wherein the organic acid salt (b) is a carboxylate having 1 to 8 carbon atoms, and the nonionic surfactant (c) having a cloud point has a cloud point of 40 to 180 ° C. Water-based emulsion.   The heat-sensitive coagulable aqueous emulsion according to any one of claims 1 to 4, further comprising a soft water repellent (d).   The heat-sensitive coagulable aqueous emulsion according to claim 5, wherein the soft water repellent (d) is silicone and / or a fluorine atom-containing organic compound.   The heat-sensitive coagulation temperature according to any one of claims 1 to 6, wherein the heat-sensitive coagulation temperature is 40 to 180 ° C.   A method for producing a leather-like sheet material, comprising impregnating a heat-coagulable water-based emulsion according to any one of claims 1 to 7 into a fiber material substrate, followed by heat-coagulation.   A leather-like sheet material obtained by the production method according to claim 8.   A leather-like sheet obtained by further post-processing the leather-like sheet material according to claim 9.