TWI547618B - Leathery sheet and manufacturing method thereof - Google Patents

Description

Leather sample and manufacturing method thereof

The present invention relates to a leather swatch such as synthetic leather or artificial leather.

Leather swatches such as synthetic leather or artificial leather are used in various fields including, for example, clothing or furniture, vehicle interior materials, shoes, and leather bags, because they have excellent hand feelings comparable to natural leather.

In the above-mentioned leather sample, an intermediate layer such as a porous layer is usually laminated on the surface of a support such as a fibrous base material, and a skin layer including a urethane resin or the like is provided on the surface layer of the intermediate layer. Each layer requires various characteristics. Specifically, the above-mentioned intermediate layer is required to have a soft hand and the like, and the skin layer is required to have durability such as sweat resistance and oil resistance in addition to the above-described flexibility.

In particular, the durability such as the sweat resistance required for the above-mentioned skin layer is a characteristic that is particularly important in the case where the use of the leather piece is expanded, even in the case where sweat or oil components adhere to the surface thereof. Further, the appearance change or deterioration of the above-mentioned skin layer and the decrease in the adhesion of the skin layer to the support are not caused, and high quality is maintained for a long period of time.

As a leather plaque having the skin layer as described above, there is known a method for producing a fibrous laminate which is formed by, for example, a fibrous substrate and a skin layer formed of a synthetic resin film by an adhesive method using an adhesive. Adhesive processing characterized in that any one or more aqueous polyurethane resins having a hydroxyl group, an amine group or an imine group in a molecular skeleton are used. The fiber base material (layer A) is treated (for example, refer to Patent Document 1).

However, when the skin layer used in the production of the above-mentioned fiber laminate is exposed to sweat or oil components for a long period of time, swelling (swelling) or cracking of the skin layer and a significant decrease in adhesion strength may occur. This may cause a poor appearance of the leather swatch or a peeling of the self-supporting body over time.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2005-206970

An object of the present invention is to provide a leather sheet having a skin layer having excellent durability such as sweat resistance and oil resistance, and the above-mentioned sweat resistance or oil resistance is such that, for example, sweat or oil components adhere to each other. In this case, the appearance of the leather piece is not deteriorated or the peeling of the self-supporting body over time is not caused.

In order to solve the above problems, the inventors of the present invention have found that the above problems can be solved by using a urethane resin, and the terminal of the urethane resin present in the urethane resin There are two or more hydroxyl groups present thereon.

That is, the present invention relates to a leather swatch characterized by comprising: a skin layer (C), an adhesive layer (D), and a support layer (E), wherein the skin layer (C) uses a urethane resin composition. The urethane resin composition contains at least one urethane resin (A) having two or more hydroxyl groups at the terminal end and an aqueous medium (B).

The leather swatch of the present invention has the following level of sweat resistance, and thus can be used, for example, for the production of clothing or furniture, vehicle interior materials, shoes, bags, etc., and the above-mentioned sweat resistance is such that even sweat, oil, solvent, or the like adheres to the skin. In the case of a layer or the like, the appearance of the leather swatch is not deteriorated or the self-supporting body is peeled off over time.

The leather swatch of the present invention is characterized by comprising: a skin layer (C), an adhesive layer (D), and a support layer (E), wherein the skin layer (C) is formed using a urethane resin composition, the above amine group The acid ester resin composition contains at least one urethane resin (A) having two or more hydroxyl groups at the terminal end and an aqueous medium (B). As the urethane resin composition which can be used for the formation of the above-mentioned skin layer (C), a urethane resin (A) having an end portion having two or more hydroxyl groups, an aqueous medium (B) and a view can be used. A urethane resin composition such as other additives required.

In the present invention, in order to solve the above problems, it is necessary to use at least one urethane resin (A) having two or more hydroxyl groups at the terminal as a urethane resin. Specifically, the urethane resin (A) is an amine group having two or more hydroxyl groups at at least one of two or more resin terminals which may be present in the urethane resin. Formate resin. For example, the above urethane resin is a urethane resin obtained by reacting a diol with a diisocyanate, and is at least 1 when it has two terminals in the above urethane resin. A urethane resin having two or more hydroxyl groups at the end. The hydroxyl group may be present in two or more at each of the two ends. In addition, the above urethane The resin is a urethane resin having a multi-branched structure, and is a urethane resin having at least one terminal having at least one hydroxyl group when it has three or more terminals.

When a urethane resin having one hydroxyl group at one end is used instead of the above urethane resin (A), the skin layer having excellent durability such as the above-mentioned sweat resistance and oil resistance cannot be formed. It may cause poor appearance of the leather swatch or peeling of the skin layer (C) from the above-mentioned adhesive layer (D) or the above-mentioned support (E). Further, when the urethane resin bonded to the urethane main chain in which the hydroxyl group is not at the terminal is used instead of the above urethane resin (A), the above-mentioned sweat resistance or oil resistance cannot be formed. The skin layer having excellent durability such as properties may cause poor appearance of the leather swatch or peeling of the skin layer (C) from the adhesive layer (D) or the support (E).

The hydroxyl group which may be present in the above urethane resin (A) is preferably 2 to 3, more preferably 2, per one terminal. Further, the hydroxyl group may be present at two or more ends of all the terminals present in the urethane resin (A). Further, the urethane resin (A) preferably has a hydroxyl value in the range of 10 to 50.

As the urethane resin (A), it is preferred to use a so-called chain (linear) obtained by using a diol as the above polyol (a1) and a diisocyanate as the above polyisocyanate (a2). a urethane resin, and a urethane resin having two or more hydroxyl groups, preferably two hydroxyl groups at each end of each of the two ends, is used for: non-destructive heat resistance (water) Durability such as sex or sweat resistance or oil resistance, Further, a skin layer (C) which is particularly excellent in bending resistance can be formed.

The urethane resin (A) preferably has a hydrophilic group in terms of stable dispersion in the aqueous medium (B).

As the hydrophilic group, for example, an anionic group, a cationic group, or a nonionic group can be used. In the case where the skin layer (C) is formed, an anionic group is more preferably used in order to rapidly increase the viscosity of the urethane resin composition used in the present invention.

As the anionic group, for example, a carboxyl group, a carboxylate group, a sulfonic acid group, a sulfonate group or the like can be used. Among them, in the case of producing a composite resin having good water dispersibility, it is preferred to use a part or all of a base. A carboxylate group or a sulfonate group neutralized with a compound or the like.

Examples of the basic compound which can be used for the neutralization of the above anionic group include an organic amine such as ammonia, triethylamine, pyridine or morpholine, or an alkanolamine such as monoethanolamine, or sodium, potassium, lithium, calcium, or the like. Metal basic compounds, etc.

When a carboxylate group or a sulfonate group is used as the above anionic group, in terms of maintaining good water dispersion stability of the urethane resin (A), it is preferred that the groups are relative to the entire amine group. The acid ester resin (A) is present in the range of 50 mmol/kg to 1,000 mmol/kg.

Further, as the above cationic group, for example, a tertiary amino group or the like can be used.

As the acid which can be used for neutralizing a part or all of the above-mentioned tertiary amine group, for example, an organic acid such as acetic acid, propionic acid, lactic acid or maleic acid, or an organic acid such as sulfonic acid or methanesulfonic acid can be used alone. Sulfonic acid, and inorganic acids such as hydrochloric acid, sulfuric acid, orthophosphoric acid, or n-phosphoric acid, or a combination of two or more.

In addition, as the quaternizing agent which can be used for the quaternization of a part or all of the above-mentioned tertiary amine group, for example, a dialkylsulfuric acid such as dimethylsulfuric acid or diethylsulfonic acid or methyl chloride (for example) can be used alone. Methyl chloride), ethyl chloride, benzyl chloride, etc., alkyl halides, methyl methanesulfonate, methyl p-toluenesulfonate, etc., alkyl or ethylene oxide, propylene oxide, An epoxy group such as chlorohydrin or two or more types may be used in combination.

Further, as the nonionic group, for example, polyoxyethylene group, polyoxypropylene group, polyoxybutylene group, poly(oxyethylene-oxypropylene) group, and polyoxyethylene-polyoxypropylene group can be used. Alkenyl. Among them, in terms of further enhancing hydrophilicity, it is preferred to use a polyoxyalkylene group having an oxyethylene unit.

The urethane resin (A) used in the present invention is preferably an amine having a weight average molecular weight in the range of 10,000 to 50,000 from the viewpoint of forming a skin layer having excellent durability such as sweat resistance. The urethane resin is more preferably a urethane resin having a weight average molecular weight of 20,000 to 50,000.

The urethane resin (A) can be produced, for example, by the following steps: producing a terminal by reacting the above polyol (a1), polyisocyanate (a2) and, if necessary, chain extender (a3) a step of the urethane prepolymer having an isocyanate group (step 1), and a step of reacting the above urethane prepolymer with a polyalkanolamine (step 2).

First, the step 1 will be described.

The above step 1 is a step of producing a urethane prepolymer having an isocyanate group at the terminal by reacting the above polyol (a1), polyisocyanate (a2) and, if necessary, a chain extender (a3). in particular, The polyol (a1), the polyisocyanate (a2) and the optional chain extender (a3) may be mixed in the absence of a solvent or in the presence of an organic solvent, and may be carried out at 50 ° C to 100 ° C. It is produced by a reaction of about 3 hours to 10 hours. Further, after the polyol (a1) and the polyisocyanate (a2) are reacted in the same manner as described above, the reactant and the chain extender (a3) may be mixed and further reacted, whereby the reaction is carried out. A urethane prepolymer having an isocyanate group at the end of the target.

As the polyol (a1) which can be used in the above step 1, for example, a polycarbonate polyol, a polyester polyol, a polyether polyol or the like can be used. Among them, in order to further enhance the sweat resistance of the skin layer (C), it is preferred to use a polycarbonate polyol.

As the polycarbonate polyol, for example, those obtained by reacting a carbonate with a low molecular weight polyol of about 100 to 500 or so can be used.

As the above carbonate, methyl carbonate or dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclic carbonate, diphenyl carbonate or the like can be used.

As the low molecular weight polyol reactive with the above carbonate, for example, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, 1, 4 can be used. -butanediol, 1,3-butanediol, 1,2-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanediol, 2,5-hexane Glycol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecane Glycol, 1,12-dodecanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,3-propanediol, 2-methyl-1,8-octanediol, 2-butyl-2-ethylpropanoldiol, 2-methyl-1,8-octanediol, 1,4- Cyclohexanediol, 1,4-cyclohexanedimethanol, hydroquinone, resorcin, bisphenol A, bisphenol F, 4,4'-biphenol, etc. Dihydroxy compound, or polyether polyol such as polyethylene glycol, polypropylene glycol, polyoxytetramethylene glycol, or polyhexamethylene adipate, polyhexamethylene polyhexamethylene Succinate), polycaprolactone and other polyester polyols.

As the above polycarbonate polyol, a polycarbonate polyol having a number average molecular weight of 500 to 3,000 is preferably used. Among them, from the viewpoint of further improving the heat resistance (water) property or the sweat resistance of the skin layer (C), it is preferred to use a polycarbonate polyol having a number average molecular weight of 500 to 1,500. On the other hand, when the skin layer (C) which satisfies the durability of the skin layer (C), such as good heat resistance (water), sweat resistance or oil resistance, and excellent bending resistance, it can be preferably used. It is a polycarbonate polyol having a number average molecular weight of more than 1,500 and 3,000 or less, more preferably 1,600 to 2,500.

The polycarbonate polyol is preferably used in an amount of from 20% by mass to 95% by mass based on the total amount of the polyol (a1).

In addition, as the polyester polyol, for example, a polyester having a low molecular weight of about 100 to 500 and a polycarboxylic acid can be used for esterification reaction.

As the above low molecular weight polyol, for example, 1,6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, 1 can be used. , 4-butanediol, 1,3-butanediol, 1,2-butanediol, 2,3- Butylene glycol, 1,5-pentanediol, 1,5-hexanediol, 2,5-hexanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octane Aliphatic pluralism such as alcohol, 1,9-nonanediol, 1,10-nonanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2-methyl-1,3-propanediol Alcohol, or cyclobutanediol, cyclopentanediol, 1,4-cyclohexanediol, cycloheptanediol, cyclooctanediol, cyclohexanedimethanol, hydroxypropylcyclohexanol, etc. containing an aliphatic ring Structure of the polyol.

As the polycarboxylic acid which can be used for the esterification reaction with the above-mentioned low molecular weight polyol, for example, succinic acid, adipic acid, sebacic acid, sebacic acid, dodecanedicarboxylic acid, butylene can be used. An aliphatic polycarboxylic acid such as an acid, or an aromatic polycarboxylic acid such as fumaric acid, terephthalic acid, isophthalic acid, phthalic acid or 1,4-naphthalene dicarboxylic acid, and the anhydride or An ester-forming derivative or the like.

In addition, as the polyether polyol, for example, one or two or more kinds of compounds having two or more active hydrogen atoms may be used as a starter to form an alkylene oxide by addition polymerization.

As the above initiator, for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, 1,3-butanediol, 1,4-butane can be used. Alcohol, 1,6-hexanediol, glycerin, trimethylolethane, trimethylolpropane, and the like.

Further, as the alkylene oxide, for example, ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin or tetrahydrofuran can be used.

In addition, as the polyol (a1), a hydrophilic group is preferably introduced from the viewpoint of introducing a hydrophilic group into the urethane resin (A).

As the above polyol having a hydrophilic group, for example, 2, 2'- can be used: a polyol having a carboxyl group such as dimethylolpropionic acid, 2,2'-dimethylolbutanoic acid, 2,2'-dimethylol-butyric acid, 2,2'-dihydroxymethylpentanoic acid, or 5 - a sulfonic acid group-containing polyol such as sulfonic acid isophthalic acid, sulfonic acid terephthalic acid, 4-sulfonic acid phthalic acid or 5[4-sulfophenoxy]isophthalic acid . Further, as the polyol having a hydrophilic group, a hydrophilic group-containing polyester obtained by reacting the above-described low molecular weight hydrophilic group-containing polyol with various polycarboxylic acids such as adipic acid may be used. Polyols, etc.

The polyol having a hydrophilic group is preferably used in an amount of from 0.5% by mass to 10% by mass, more preferably from 1% by mass to 5% by mass, based on the total amount of the polyol (a1).

Further, as the polyisocyanate (a2) which can be reacted with the above polyol (a1), for example, phenylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate or naphthalene diisocyanate can be used alone. An aromatic polyisocyanate such as polymethylene polyphenyl polyisocyanate or carbodiimidized diphenylmethane polyisocyanate, or hexamethylene diisocyanate, diazonic acid diisocyanate, cyclohexane diisocyanate or different Vulcanone diisocyanate, dicyclohexylmethane diisocyanate, xylylene diisocyanate, tetrametyl xylylene diisocyanate, dimer acid diisocyanate, norbornene diisocyanate A polyisocyanate or the like having an aliphatic ring structure or the like may be used in combination of two or more kinds. Among them, it is preferred to use a polyisocyanate having an aliphatic cyclic structure, particularly to prevent the yellowing of the epidermal layer (C) over time, and more preferably to use isophorone diisocyanate or dicyclohexylmethane. Isocyanate.

The reaction between the polyol (a1) and the polyisocyanate (a2) is preferably an equivalent ratio of the hydroxyl group of the polyol (a1) to the isocyanate group of the polyisocyanate (a2) [isocyanate group/hydroxy group]. The range of 1.0 to 2.0 is preferably 1.1 to 1.9.

As the chain extender (a3), for example, a polyamine or a compound containing a hydroxyl group can be used.

As the above polyamine, for example, ethylenediamine, 1,2-propanediamine, 1,6-hexanediamine, piperazine, 2,5-dimethylpiperazine, isophoronediamine, 4 can be used. , 4'-dicyclohexylmethanediamine, 3,3'-dimethyl-4,4'-dicyclohexylmethanediamine, 1,4-cyclohexanediamine and other diamines; N-hydroxyl Aminoamine, N-hydroxyethylaminoethylamine, N-hydroxypropylaminopropylamine, N-ethylaminoethylamine, N-methylaminopropylamine, etc. contain one primary amine group and one two Aminamine-based diamines; polyamines such as diethylenetriamine, dipropylenetriamine, and triethylenetetramine; hydrazine, N,N'-dimethylhydrazine, 1,6-hexamethylene biguanide, etc. Terpenoids; diterpene succinate, diterpene adipate, diammonium glutarate, diterpene sebacate, diterpene isophthalate, etc.; β-half-cyanate Semiquine such as strontium strontium, 3-half-carbo-propyl-carbazate, semicarbazone-3-semicarbazide methyl-3,5,5-trimethylcyclohexane.

The hydroxyl group-containing compound is used in the range in which the storage stability of the urethane resin composition used in the present invention does not decrease, and for example, ethylene glycol or two may be used alone. , triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol (hexamethylene glycol), sucrose, methyl glycol (methylene glycol) ), glycols such as glycerin, sorbitol, bisphenol A, 4,4'-dihydroxybiphenyl, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl A phenol such as hydrazine, hydrogenated bisphenol A or hydroquinone, water, or the like, or two or more kinds thereof may be used in combination.

The urea bond is introduced into the formed skin layer, and as a result, the chain extender (a3) is relative to the urethane resin from the viewpoint of further improving the durability of the skin layer. The total amount of the raw materials used in the production of A) is preferably in the range of 1% by mass to 10% by mass, and more preferably in the range of 1% by mass to 5% by mass.

In the above step 1, as the organic solvent which can be used for the reaction of the polyol (a1), the polyisocyanate (a2) and the optional chain extender (a3), for example, acetone or methylethyl can be used alone. Ketones such as ketones; ethers such as tetrahydrofuran and dioxane; acetates such as ethyl acetate and butyl acetate; nitriles such as acetonitrile; and guanamines such as dimethylformamide and N-methylpyrrolidone; Or use two or more types.

The urethane prepolymer obtained in the above step 1 is preferably a functional group at the molecular terminal thereof which can be reacted with the amine group of the polyalkanolamine in the step 2. The functional group is preferably an isocyanate group.

The urethane prepolymer obtained in the above step 1 may be a solventless type, but from the viewpoint of imparting good handleability, it is preferably a type dissolved in the above organic solvent.

Next, the above step 2 will be described.

Step 2 is a step of mixing and reacting the isocyanate group-containing urethane prepolymer obtained in the above step 1 or an organic solvent solution thereof with a polyalkanolamine, thereby obtaining the obtained amine Two or more hydroxyl groups are introduced into one or more terminals existing in the urethane resin (A).

Specifically, the above-described isocyanate group-containing urethane prepolymer or an organic solvent solution thereof or an aqueous dispersion thereof is mixed with a polyalkanolamine, and the reaction is carried out, for example, at a normal temperature of 25 ° C. The desired urethane resin (A) was produced. At this time, the amount of the hydroxyl group introduced into the obtained urethane resin (A) can be adjusted by adjusting the amount of the polyalkanolamine used.

The polyalkanolamine (a4) may be used alone, for example, diethanolamine or 2-amino-1, insofar as the storage stability of the urethane resin composition used in the present invention does not decrease. 3-propanediol, (R)-3-amino-1,2-propanediol, tris(hydroxymethyl)aminoethane, 1-amino-1-deoxy-D-glucitol as opposed to 1 amine An amine having a plurality of hydroxyl groups or two or more kinds thereof may be used in combination.

The urethane resin composition for forming a skin layer used in the present invention may be a solventless urethane resin composition containing the urethane resin (A), but is imparted well. From the viewpoint of coating workability and the like, a solvent-containing urethane resin composition is preferable. As the above solvent, an aqueous medium or various organic solvents can be used.

Further, when a urethane resin composition containing the above urethane resin (A) and an aqueous medium (B) is used as the urethane resin composition for forming the skin layer, it is preferably The urethane resin (A) or an organic solvent solution thereof is produced by the above steps 1 and 2, and then, if necessary, the hydrophilic group such as an anionic group in the above urethane resin is neutralized. After that, an aqueous medium is supplied, and the above urethane resin (A) is dispersed in the aqueous medium. When the above urethane resin (A) is mixed with an aqueous medium, a homogenizer or the like may be used as needed. mechanical.

Examples of the aqueous medium (B) include water, an organic solvent mixed with water, and a mixture thereof. Examples of the organic solvent to be mixed with water include alcohols such as methanol, ethanol, n-propanol, and isopropanol; ketones such as acetone and methyl ethyl ketone; and ethylene glycol, diethylene glycol, and propylene glycol. Polyalkylene glycols; alkyl ethers of polyalkylene glycols; indoleamines such as N-methyl-2-pyrrolidone. In the present invention, water alone may be used, and a mixture of water and an organic solvent mixed with water may be used, or only an organic solvent mixed with water may be used. From the viewpoint of safety or load on the environment, it is preferred to use only water, or a mixture of water and an organic solvent mixed with water, and particularly preferably only water.

The total amount of the aqueous medium (B) relative to the urethane resin composition for forming the skin layer is preferably 40% by mass to 85% by mass, more preferably 50% by mass to 80% by mass. The range of %.

Further, examples of the organic solvent include ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran and dioxane; acetates such as ethyl acetate and butyl acetate; and nitriles such as acetonitrile; Indoleamines such as carbamide and N-methylpyrrolidone.

The urethane resin composition for forming a skin layer used in the present invention preferably contains the above urethane resin (A) 10 mass based on the total amount of the urethane resin composition. The range of % to 50% by mass is preferably 20% by mass to 50% by mass in terms of improving coating workability.

In view of the formation of the skin layer (C) which is particularly excellent in durability such as heat resistance (water), sweat resistance, oil resistance, and hydrolysis resistance, the present invention The above urethane resin composition used may be used in combination with a crosslinking agent.

As the crosslinking agent, for example, a carbodiimide crosslinking agent, an oxazoline crosslinking agent, an epoxy crosslinking agent, an isocyanate crosslinking agent, a melamine crosslinking agent, and the like can be used. The crosslinking agent is preferably a carbodiimide crosslinking agent or an oxazoline crosslinking agent.

In order to further improve durability such as heat resistance (water), sweat resistance, and oil resistance, the crosslinking agent is preferably used in an amount of 1 part by mass based on 100 parts by mass of the urethane resin (A). ~10 parts by mass range.

In addition, the urethane resin composition for forming a skin layer used in the present invention may contain various additives as needed. For example, it can be used in combination: an associative tackifier, a urethane catalyst, a decane coupling agent, a filler, a thixotropic agent, an adhesion promoter, a wax, a heat stabilizer, a light stabilizer, and a fluorescent whitening agent. Additives such as agents and foaming agents, thermoplastic resins, thermosetting resins, pigments, dyes, conductivity imparting agents, antistatic agents, moisture permeability improving agents, water repellents, oil repellents, hollow foams, and crystals Water compound, flame retardant, water absorbing agent, moisture absorbent, deodorant, foam stabilizer, antifoaming agent, antifungal agent, preservative, algicide, pigment dispersant, anti-caking agent, anti-hydrolysis agent .

As the associative tackifier, for example, a cellulose derivative such as hydroxyethyl cellulose, methyl cellulose or carboxymethyl cellulose, or a polyacrylate, polyvinylpyrrolidone or urethane can be used. Ester type, polyether type, etc. Among them, in view of good compatibility with the above urethane resin (A), it is preferred to use a urethane-based associative tackifier. Associative type thickening The amount of the agent relative to the total amount of the urethane resin (A) is preferably in the range of 0.5% by mass to 5% by mass.

The urethane resin composition can form a film having the following level of sweat resistance, and therefore can be preferably used as a coating agent for forming a top coat layer of various substrates, and the above-mentioned sweat resistance. In order to adhere to sweat or the like, the appearance of the leather swatch is not deteriorated or the support is peeled off over time. In particular, it can be preferably used for the formation of the skin layer (C) constituting the leather swatch.

The urethane resin composition for forming the above-mentioned skin layer can be used as a material for forming the skin layer (C) of the above leather sample. The leather sample is usually on the surface of the support layer (E), and a skin layer (C) is laminated via the adhesive layer (D) (the support layer (E) includes a fibrous substrate impregnated with a resin as needed), and the present invention can be used. The urethane resin composition used in the invention is preferably used for the formation of the above-mentioned skin layer (C). In addition, the leather sheet may have a porous layer (foamed layer) for the purpose of imparting flexibility or the like, or may be foamed to the above-mentioned adhesive layer (D) and substantially correspond to the porous layer.

As the support which can be used for forming the above-mentioned support layer (E), a nonwoven fabric, a woven fabric, a woven fabric or the like can be used. As the substrate constituting the substrate, for example, polyester fiber, nylon fiber, acrylic fiber, polyurethane fiber, acetate fiber, ray fiber, polylactic acid fiber, or cotton, hemp, silk, wool, or the like can be used. Or blended fibers of these or the like.

On the surface of the support body, antistatic processing or mold release processing, water repellent processing, water absorption processing, antibacterial and deodorizing processing, and manufacturing may be performed as needed. Bacterial processing, UV blocking processing, etc.

The leather sample sheet in which the skin layer (C) is laminated on the surface of the support via the adhesive layer (D) can be produced, for example, by applying the urethane resin composition for forming the skin layer described above. The release-treated sheet is dried and dried to form a skin layer (C), and then the support layer is layered on the skin layer (C) by an adhesive (d) or the like.

Examples of the method of applying the above urethane resin composition to the above-mentioned sheet include a gravure coater method, a knife coater method, a pipe coater method, and a knife coater method ( Comma coater method) and so on. In addition, as a method of drying and hardening the urethane resin composition applied by the above method, for example, it may be placed at a normal temperature for about 1 to 10 days or at a temperature of 50 to 250 ° C. The method of heating for about 1 second to 600 seconds.

As the adhesive (d) for the adhesion of the above-mentioned skin layer (C) to the above-mentioned support layer (E), it is preferred to use a compound (d-1) having a hydroxyl group and a compound (d-2) having an isocyanate group. Adhesive.

As the above-mentioned adhesive (d), it is preferred to use an adhesive which contains the above-mentioned compound (d-2) having an isocyanate group excessively with respect to the compound (d-1) having a hydroxyl group. Thereby, the adhesive layer (D) is formed by reacting the hydroxyl group of the above compound (d-1) with the isocyanate group of the above compound (d-2), and the isocyanate group of the compound (d-2) remaining in the above reaction By reacting a part or all of the hydroxyl group of the urethane resin (A) forming the skin layer (C), a leather sample sheet having excellent durability such as the following sweat resistance and the like can be obtained. Epidermis, The above-mentioned sweat resistance is such that even when it adheres to sweat or the like, it does not cause appearance defects or peeling of the self-supporting body over time.

In the above-mentioned compound (d-2), it is preferred that the isocyanate group of the compound (d-2) contained in the above-mentioned adhesive (d) and the compound (d-1) The equivalent ratio of the hydroxyl group [isocyanate group / hydroxyl group] is in the range of more than 1.0.

As the above-mentioned adhesive (d), specifically, a two-part type adhesive comprising a urethane resin having a hydroxyl group and a crosslinking agent having an isocyanate group can be used.

As the above-described urethane resin having a hydroxyl group which can be used for the above-mentioned adhesive (d), the following urethane resin can be used: by using and manufacturing the above urethane resin (A) The urethane resin obtained by reacting the polyol (a1), the polyisocyanate (a2), the chain extender (a3), and the like exemplified above is the same.

When the above-described urethane resin having a hydroxyl group is produced, from the viewpoint of imparting a hydroxyl group reactive with the isocyanate group of the above crosslinking agent, it is preferred to use a reaction obtained by: The ratio of the isocyanate group of the polyisocyanate of the urethane resin to the equivalent ratio of the hydroxyl group of the polyol (the isocyanate group/hydroxy group) is less than 1.0, and the polyisocyanate is mixed with the polyol. reaction.

In order to exhibit excellent adhesion strength, the urethane resin having a hydroxyl group obtained as described above is preferably one having a weight average molecular weight of about 10,000 to 50,000.

Further, as the above-mentioned adhesive (d), in addition to the above adhesive, A two-part type adhesive containing a polyol and a polyisocyanate is used.

The two-pack type adhesive is rapidly applied to the surface of the support by mixing the above polyol and polyisocyanate, thereby forming an adhesive layer (D) having a urethane bond.

As the polyol which can be used for the above-mentioned two-liquid type adhesive, the same polyol as the polyol (a1) exemplified by the user when the above urethane resin (A) is produced can be used. Specifically, a polycarbonate polyol or the like can be used.

Further, as the polyisocyanate which can be used for the above-mentioned two-liquid type adhesive, the same polyisocyanate as the polyisocyanate (a2) exemplified by the user when the urethane resin (A) is produced can be used.

The reaction with the hydroxyl group of the urethane resin (A) forming the skin layer (C) is carried out to form a skin layer (C) having durability such as the following level of sweat resistance (the above-mentioned sweat resistance is That is, in the case where it is easy to adhere to sweat or the like, the appearance of the leather sample is not caused to be bad or the self-supporting body is peeled off from time to time. The above two-liquid type adhesive is preferably used in the isocyanate group of the above polyisocyanate. When the equivalent ratio of the hydroxyl group of the polyol (the isocyanate group/hydroxy group) exceeds 1.0, the above polyol and the polyisocyanate are mixed.

As the above-mentioned adhesive (d), a hardening component such as a urethane resin having a hydroxyl group or a crosslinking agent having an isocyanate group, a polyol or a polyisocyanate as described above may be used or dispersed in a solvent such as water or a solvent. As a result, a solvent-free adhesive can also be used.

The above adhesive (d) can be applied by, for example, gravure coater or knife coating A method such as a machine method, a pipe coater method, or a knife coater method is applied to the surface of the support (C) or the skin layer (C). When the above-mentioned adhesive layer (D) is foamed to form a porous layer, the above porous layer can be formed by applying the above-mentioned adhesive (d) to the surface of the support, generally referred to as mechanical The method of the foaming method, or adding an additive such as a microsphere or a foaming agent to foam it.

The adhesive layer (D) and the skin layer (C) are heated under conditions of 40 ° C to 120 ° C in a state where the coated surface of the adhesive ( d ) and the skin layer (C) are laminated. At the interface, the isocyanate group present in the above-mentioned adhesive (d) is reacted with the hydroxyl group present in the above-mentioned skin layer (C), and a leather plaque having the following skin layer can be obtained, and the skin layer is provided even in sweat. In the case of adhesion or the like, the appearance of the leather plaque is not deteriorated, and the durability such as the sweat resistance or the oil resistance of the support for the temporal peeling of the support is not caused.

In addition, when the intermediate layer such as a porous layer is provided in addition to the above-mentioned adhesive layer (D), for example, a urethane resin composition for forming the above-mentioned skin layer can be obtained, for example. It is applied to a sheet subjected to mold release treatment and dried to form a skin layer (C), which is then carried out by a mechanical foaming method or a water foaming method known from the prior art. The foamed porous layer-forming resin composition is applied onto the skin layer (C) and cured to form a porous layer, and then the support (C) is laminated on the surface by the above-mentioned adhesive (d) or the like. On the porous layer.

The thickness of the skin layer (C) constituting the leather sample obtained above is preferably in the range of approximately 10 μm to 300 μm. In addition, the above adhesive layer (D) It is also preferably a thickness of 10 μm to 300 μm.

The leather sample obtained by the above method is excellent in durability such as sweat resistance and oil resistance, and abrasion resistance, and thus can be used for various purposes such as a bag, a shoe, a garment, and a vehicle interior material.

[Example]

Hereinafter, the present invention will be more specifically described by way of examples and comparative examples.

[Preparation Example 1] Preparation of Adhesive (d1-1)

In the presence of methyl ethyl ketone 1221 g and stannous octoate 0.1 g, a polycarbonate diol (Nippolan N980R; Nippon Polyurethane Industry (stock): number average molecular weight 2000) 1000 g, dimethylolpropionic acid 34 g, and dicyclohexylmethane diisocyanate (HMDI) 187 g were reacted at 70 ° C until the isocyanate group disappeared, whereby a methyl ethyl ketone solution of a urethane resin having a hydroxyl group at the terminal was obtained.

After mixing 2462 g of the methyl ethyl ketone solution of the above urethane resin and 25 g of triethylamine, it was mixed with 2442 g of pure water, and then subjected to phase transfer emulsification, whereby an emulsion was obtained.

Then, methyl ethyl ketone was distilled off from the above emulsion, whereby a urethane resin composition [d1-1-1] having a nonvolatile content of 45% by mass was obtained.

The above obtained urethane resin composition [d1-1-1] 100 g and an anthrone ketone leveling agent 0.2 g, an anthrone ketone antifoaming agent 0.1 g, a urethane 1.0 g of an associative tackifier and 5.0 g of an isocyanate crosslinker were stirred at 2000 rpm for 2 minutes using a mechanical mixer, followed by defoaming using a vacuum defoamer, thereby obtaining a water-based adhesive (d1-1) ).

[Preparation Example 2] Preparation of Adhesive (d1-2)

Polycarbonate diol (Nippolan N980R; Nippon Polyurethane Industry: Quantitative Molecular Weight 2000) warmed to 80 ° C at 2000 rpm using a mechanical mixer in a nitrogen atmosphere at a dose of 0.1 g of stannous octoate 100 g, and 14 g of dicyclohexylmethane diisocyanate (HMDI) were stirred for 2 minutes, followed by defoaming using a vacuum defoaming machine, thereby obtaining a solventless adhesive (d1-2).

[Example 1] Production of leather samples

In the presence of methyl ketone 710 g and stannous octoate 0.1 g, a polycarbonate diol (Nippolan N981; Nippon Polyurethane Industry (stock): number average molecular weight 1000) 1000 g, dimethylolpropionic acid 67 g, and dicyclohexylmethane diisocyanate (HMDI) 590 g were reacted at 70 ° C until the NCO% reached 2.7% by mass, thereby obtaining a urethane prepolymer having an isocyanate group at the end (A'- 1) A solution of methyl ethyl ketone. Further, the above NCO% is a ratio of the mass of the isocyanate group of the polyisocyanate in the raw material to the total mass of the raw material for producing the above-mentioned polyurethane.

2367 g of a methyl ethyl ketone solution containing the isocyanate group-containing urethane prepolymer (A'-1) and 50 g of triethylamine were mixed, and then mixed with 2367 g of pure water, and then the phases were mixed. The emulsification is transferred, whereby an emulsion is obtained.

To the obtained emulsion, 1310 g of an aqueous chain extender solution containing 36 g of ethylenediamine and 95 g of diethanolamine was supplied and mixed to carry out a chain extension reaction.

Then, methyl ethyl ketone was distilled off from the above reaction mixture, whereby a urethane resin composition [I] having a nonvolatile content of 35% by mass (weight average molecular weight: 42,000, hydroxyl value: 56.7) was obtained.

The above obtained urethane resin composition [I] 100 g and an anthrone-based leveling agent 0.2 g, an anthrone-based antifoaming agent 0.1 g, an urethane-based associative tackifier 1.0 were added. g, the mixture was stirred at 2000 rpm for 2 minutes using a mechanical mixer, followed by defoaming using a vacuum defoaming machine, whereby a urethane resin composition [I-1] for forming a skin layer was obtained.

100 parts by mass of the urethane resin composition [I-1] for forming the above-mentioned skin layer was applied to release paper (155T Flat Japan Printing Co., Ltd.) so that the film thickness after coating was 150 μm. ) Manufacturing).

Immediately after the above coating, the Werner Mathis (dryer) was pre-dried at 70 ° C for 2 minutes, and then dried at 120 ° C for 2 minutes to completely evaporate the water contained in the coating layer. A polyurethane film was obtained.

100 parts by mass of the adhesive (d1-1) obtained in the above Preparation Example 1 was applied onto the polyurethane resin film obtained by the above method so as to have a film thickness of 150 μm, and then used. Werner Mathis (dryer) was dried at 70 ° C for 2 minutes.

After the drying, the support containing the polyester fiber nonwoven fabric was placed on the coated surface of the above-mentioned adhesive (d1-1), and pressure-bonded using a roller adjusted to 120 ° C, and then carried out at 80 ° C for 24 hours. Ageing. After the aging, the above release paper was removed, whereby a leather plaque [I-2] was obtained.

[Example 2] Production of leather samples

On the other hand, 100 parts by mass of the urethane resin composition [I-1] for forming the skin layer used in the above Example 1 was applied to the film thickness after the coating was 150 μm. Molded paper (manufactured by 155T Flat Japan Printing Co., Ltd.).

Immediately after the above coating, the Werner Mathis (dryer) was pre-dried at 70 ° C for 2 minutes, and then dried at 120 ° C for 2 minutes to completely evaporate the water contained in the coating layer. A polyurethane film was obtained.

100 parts by mass of the adhesive (d1-2) obtained in Preparation Example 2 was applied onto the polyurethane resin film obtained by the above method so that the film thickness thereof became 150 μm. Further, a support comprising a polyester fiber nonwoven fabric was placed on the coated surface of the above-mentioned adhesive (d1-2), and pressure-bonded using a roller adjusted to 120 ° C, and then aged at 80 ° C for 24 hours. After the aging, the above release paper was removed, whereby a leather plaque [II-2] was obtained.

[Example 3] Production of leather samples

In the presence of methyl ethyl ketone 710 g and stannous octoate 0.1 g, the polyester diol (Placcel 210, Daicel Chemical (share): molecular weight of about 1000) 1000 g, dimethylolpropionic acid 67 g and two 590 g of cyclohexylmethane diisocyanate (HMDI) was reacted at 70 ° C until the NCO% reached 2.7% by mass, whereby a methyl group of a urethane prepolymer (A'-2) having an isocyanate group at the end was obtained. Ethyl ketone solution.

2367 g of the methyl ethyl ketone solution of the urethane prepolymer (A'-2) was mixed with 50 g of triethylamine, and then mixed with 2367 g of pure water, followed by phase transfer emulsification. Obtain an emulsion.

To the obtained emulsion, 1310 g of an aqueous chain extender solution containing 36 g of ethylenediamine and 95 g of diethanolamine was supplied and mixed to carry out a chain extension reaction.

Then, methyl ethyl ketone was distilled off from the above reaction mixture, whereby a urethane resin composition [II] having a nonvolatile content of 35% by mass (weight average molecular weight: 41,000, hydroxyl value: 56.7) was obtained.

The above obtained urethane resin composition [II] 100 g and an anthrone-based leveling agent 0.2 g, an anthrone-based defoaming agent 0.1 g, an urethane-based association type tackifier 1.0 were added. g, the mixture was stirred at 2000 rpm for 2 minutes using a mechanical mixer, followed by defoaming using a vacuum defoaming machine, whereby a urethane resin composition [II-2] for forming a skin layer was obtained.

In place of the above-described urethane resin composition [I-1] for forming a skin layer, 100 parts by mass of the urethane resin composition [II-1] for forming the skin layer is used. A leather plaque [III-2] was obtained in the same manner as in Example 1.

[Example 4] Production of leather samples

Polyethylene glycol (Nippolan N981; Nippon Polyurethane Industry (stock): number average molecular weight 1000) 1000 g, polyethylene glycol (PEG 1000) in the presence of methyl ketone 710 g and stannous octoate 0.1 g , Nippon Oil (share) 50 g, polyethylene glycol monomethyl ether (Uniox M1000: Nippon Oil (share)) 50 g and dicyclohexylmethane diisocyanate (HMDI) 590 g at 70 ° C to NCO% A solution of the methyl ethyl ketone of the urethane prepolymer (A'-3) having an isocyanate group at the end was obtained up to 2.7% by mass.

2400 g of a methyl ethyl ketone solution containing the isocyanate group-containing urethane prepolymer (A'-3) at the above end, and a previously prepared emulsifier 10% by mass aqueous solution (Newcol 2314: Japanese emulsifier (share) After mixing 2400 g, phase transfer emulsification was carried out, thereby obtaining an emulsion.

To the obtained emulsion, 1310 g of an aqueous chain extender solution containing 36 g of ethylenediamine and 95 g of diethanolamine was supplied and mixed to carry out a chain extension reaction.

Then, methyl ethyl ketone was distilled off from the above reaction mixture, whereby a urethane resin composition [III] having a nonvolatile content of 35% by mass (weight average molecular weight: 43,000, hydroxyl value: 55.7) was obtained.

The above obtained urethane resin composition [III] 100 g and an anthrone-based leveling agent 0.2 g, an anthrone-based antifoaming agent 0.1 g, an urethane-based associative tackifier 1.0 were added. g, the mixture was stirred at 2000 rpm for 2 minutes using a mechanical mixer, followed by defoaming using a vacuum defoaming machine, whereby a urethane resin composition [III-1] for forming a skin layer was obtained.

In place of the above-described urethane resin composition [I-1] for forming a skin layer, 100 parts by mass of the urethane resin composition [III-1] for forming the skin layer is used. A leather sample [IV-2] was obtained in the same manner as in Example 1.

[Example 5] Production of leather samples

Polycarbonate diol (Nippolan N980R; Nippon Polyurethane Industry (stock): number average molecular weight 2000) 1000 g, dimethylolpropionic acid in the presence of methyl ethyl ketone 630 g and stannous octoate 0.1 g 67 g and dicyclohexylmethane diisocyanate (HMDI) 390 g The reaction was carried out at 70 ° C until the NCO% reached 2.0% by mass, whereby a methyl ethyl ketone solution of the urethane prepolymer (A'-4) having an isocyanate group at the end was obtained.

2087 g of a methyl ethyl ketone solution containing the isocyanate group-containing urethane prepolymer (A'-4) and 50 g of triethylamine were mixed, and then mixed with 2367 g of pure water, and then the phases were mixed. The emulsification is transferred, whereby an emulsion is obtained.

To the obtained emulsion, 770 g of an aqueous chain extender solution containing 24 g of ethylenediamine and 53 g of diethanolamine was supplied and mixed, whereby a chain extension reaction was carried out.

Then, methyl ethyl ketone was distilled off from the above reaction mixture, whereby a urethane resin composition [IV] having a nonvolatile content of 35% by mass (weight average molecular weight: 42,000, hydroxyl value: 36.8) was obtained.

The above obtained urethane resin composition [IV] 100 g and an anthrone-based leveling agent 0.2 g, an anthrone-based antifoaming agent 0.1 g, an urethane-based associative tackifier 1.0 were added. g, using a mechanical mixer to stir at 2000 rpm for 2 minutes, followed by defoaming using a vacuum defoaming machine, thereby obtaining a urethane resin composition for forming a skin layer [IV-1]

In place of the above-described urethane resin composition [I-1] for forming a skin layer, 100 parts by mass of the urethane resin composition [IV-1] for forming the skin layer is used. A leather sample [V-2] was obtained in the same manner as in Example 1.

[Example 6] Production of leather samples

In the presence of methyl ketone 710 g and stannous octoate 0.1 g, Carbonate diol (Nippolan N981; Nippon Polyurethane Industry (stock): number average molecular weight 1000) 1000 g, dimethylolpropionic acid 67 g and dicyclohexylmethane diisocyanate (HMDI) 590 g at 70 ° C The methyl ethyl ketone solution of the urethane prepolymer (A'-1) having an isocyanate group at the end was obtained until the NCO% reached 2.7% by mass.

2367 g of a methyl ethyl ketone solution containing the isocyanate group-containing urethane prepolymer (A'-1) and 50 g of triethylamine were mixed, and then mixed with 2367 g of pure water, and then the phases were mixed. The emulsification is transferred, whereby an emulsion is obtained.

To the obtained emulsion, 530 g of an aqueous chain extender solution containing 42 g of ethylenediamine and 11 g of diethanolamine was supplied and mixed to carry out a chain extension reaction.

Then, methyl ethyl ketone was distilled off from the above reaction mixture, whereby a urethane resin composition [V] having a nonvolatile content of 35% by mass (weight average molecular weight: 42,000, hydroxyl value: 6.9) was obtained.

The above obtained urethane resin composition [V] 100 g and an anthrone-based leveling agent 0.2 g, an anthrone-based defoaming agent 0.1 g, an urethane-based association type tackifier 1.0 were added. g, stirring using a mechanical mixer at 2000 rpm for 2 minutes, followed by defoaming using a vacuum defoaming machine, thereby obtaining a urethane resin composition for forming a skin layer [V-1]

In place of the above-described urethane resin composition [I-1] for forming a skin layer, 100 parts by mass of the urethane resin composition [V-1] for forming the skin layer is used. The same method as in Example 1 was obtained. Leather sample [V-2].

[Comparative Example 1] Production of leather samples

In the presence of methyl ketone 710 g and stannous octoate 0.1 g, a polycarbonate diol (Nippolan N981; Nippon Polyurethane Industry (stock): number average molecular weight 1000) 1000 g, dimethylolpropionic acid 67 g and dicyclohexylmethane diisocyanate (HMDI) 590 g were reacted at 70 ° C until the NCO% reached 2.7% by mass, whereby a urethane prepolymer having an isocyanate group at the end (A'-1) was obtained. a solution of methyl ethyl ketone.

2367 g of a methyl ethyl ketone solution containing the isocyanate group-containing urethane prepolymer (A'-1) and 50 g of triethylamine were mixed, and then mixed with 2367 g of pure water, and then the phases were mixed. The emulsification is transferred, whereby an emulsion is obtained.

To the obtained emulsion, 910 g of an aqueous chain extender solution containing 36 g of ethylenediamine and 55 g of monoethanolamine was supplied and mixed to carry out a chain extension reaction.

Then, methyl ethyl ketone was distilled off from the above reaction mixture, whereby a urethane resin composition [I'] having a nonvolatile content of 35% by mass (weight average molecular weight: 39,000, hydroxyl value: 28.9) was obtained. .

Adding 100 g of the urethane resin composition [I'] obtained above and 0.2 g of an anthrone-based leveling agent, 0.1 g of an anthrone-based antifoaming agent, and an amine-based adhesion-type tackifier 1.0 g, which was stirred at 2000 rpm for 2 minutes using a mechanical mixer, followed by defoaming using a vacuum defoaming machine, thereby obtaining a urethane resin composition [I'-1] for forming a skin layer.

In place of the above-described urethane resin composition [I-1] for forming a skin layer, 100 parts by mass of the urethane resin composition [I'-1] for forming the skin layer is used. A leather plaque [I'-2] was obtained in the same manner as in Example 1.

[Comparative Example 2] Production of leather samples

In the presence of methyl ketone 710 g and stannous octoate 0.1 g, a polycarbonate diol (Nippolan N981; Nippon Polyurethane Industry (stock): number average molecular weight 1000) 1000 g, dimethylolpropionic acid 67 g and dicyclohexylmethane diisocyanate (HMDI) 590 g were reacted at 70 ° C until the NCO% reached 2.7% by mass, whereby a urethane prepolymer having an isocyanate group at the end (A'-1) was obtained. a solution of methyl ethyl ketone.

2367 g of a methyl ethyl ketone solution containing the isocyanate group-containing urethane prepolymer (A'-1) and 50 g of triethylamine were mixed, and then mixed with 2367 g of pure water, and then the phases were mixed. The emulsification is transferred, whereby an emulsion is obtained.

To the obtained emulsion, 520 g of an aqueous chain extender solution containing 21 g of N-(aminoethyl)ethanolamine and 31 g of monoethanolamine was supplied and mixed to carry out a chain extension reaction.

Then, methyl ethyl ketone was distilled off from the above reaction mixture, whereby a urethane resin composition [II'] having a nonvolatile content of 35% by mass was obtained (weight average molecular weight: 40,000, hydroxyl value: 23, 2).

100 g of the urethane resin composition [II'] obtained above and 0.2 g of an anthrone-based leveling agent, 0.1 g of an anthrone-based antifoaming agent, and an urethane system were added. 1.0 g of the associative tackifier, which was stirred at 2000 rpm for 2 minutes using a mechanical mixer, followed by defoaming using a vacuum defoaming machine, thereby obtaining a urethane resin composition for forming a skin layer [II' -1].

In place of the urethane resin composition [I-1] for forming the skin layer, 100 parts by mass of the urethane resin composition [II'-1] for forming the above-mentioned skin layer is used. A leather plaque [II'-2] was obtained in the same manner as in Example 1.

[Comparative Example 3] Production of leather samples

In the presence of methyl ketone 710 g and stannous octoate 0.1 g, a polycarbonate diol (Nippolan N981; Nippon Polyurethane Industry (stock): number average molecular weight 1000) 1000 g, dimethylolpropionic acid 67 g and dicyclohexylmethane diisocyanate (HMDI) 590 g were reacted at 70 ° C until the NCO% reached 2.7% by mass, whereby a urethane prepolymer having an isocyanate group at the end (A'-1) was obtained. a solution of methyl ethyl ketone.

2367 g of a methyl ethyl ketone solution containing the isocyanate group-containing urethane prepolymer (A'-1) and 50 g of triethylamine were mixed, and then mixed with 2367 g of pure water, and then the phases were mixed. The emulsification is transferred, whereby an emulsion is obtained.

To the obtained emulsion, 1400 g of an aqueous chain extender solution containing 36 g of ethylenediamine and 116 g of dibutylamine was supplied and mixed, whereby a chain extension reaction was carried out.

Then, methyl ethyl ketone was distilled off from the above reaction mixture, whereby a urethane resin composition [III'] having a nonvolatile content of 35% by mass was obtained. (weight average molecular weight was 39,000, hydroxyl value was 0.0).

100 g of the urethane resin composition [III'] obtained above and 0.2 g of an anthrone-based leveling agent, 0.1 g of an anthrone-based defoaming agent, and an amine-based adhesion-type tackifier 1.0 g, which was stirred at 2000 rpm for 2 minutes using a mechanical mixer, followed by defoaming using a vacuum defoaming machine, thereby obtaining a urethane resin composition [III'-1] for forming a skin layer.

In place of the above-described urethane resin composition [I-1] for forming a skin layer, 100 parts by mass of the urethane resin composition [III'-1] for forming the skin layer is used. A leather plaque [III'-2] was obtained in the same manner as in Example 1.

[Evaluation method of adhesion]

A hot-melt tape (manufactured by Sun Kasei Co., Ltd.) having a width of 1 Å was adhered to the surface of the skin layer of the leather plaque obtained in the examples and the comparative examples at a temperature of 130 ° C for 5 seconds, in accordance with JIS K6854-2. The peel strength in a state of a temperature of 23 ° C and a relative humidity of 65% was measured using Tensilon (head speed = 200 mm/min). When the peel strength of the skin layer constituting the leather plaque is 3.0 kg/cm or more, it is judged that the skin layer has practically sufficient adhesion to the support.

[Method 1 for evaluation of sweat resistance (perspiration resistance 1)]

The filter paper immersed in oleic acid having the same mass as that of the dried filter paper was placed on the skin layer of the leather plaque obtained in the above examples and comparative examples, and heated at 80 ° C for 24 hours.

After heating, the above filter paper was removed, and oleic acid adhering to the surface of the above skin layer was wiped with waste yarn.

The surface of the skin layer after the above wiping was visually observed, and evaluated according to the following evaluation criteria.

A; no change in appearance and no peeling of the skin layer as compared with before the adhesion of oleic acid.

B; A slight swelling (swelling of the skin layer) was observed in a very small portion as compared with before the oleic acid was attached, but the peeling of the skin layer was not observed in a practically problem-free level.

C; Swelling (swelling of the skin layer) which was clearly confirmed was observed in appearance as compared with before oleic acid was adhered, but peeling of the skin layer was not observed.

D; the swelling which is clearly confirmed (the swelling of the skin layer) was observed in appearance, and the peeling of the part of the skin layer was seen, compared with before the oleic acid was attached.

E; most of the epidermal layer is stripped or dissolved.

[Method 2 of evaluation of sweat resistance (perspiration resistance 2)]

The leather pieces obtained in the above examples and comparative examples were immersed in oleic acid and left in an environment of 25 ° C for 3 days.

After standing, the gauze was removed, and rancid acid adhering to the surface of the above skin layer was wiped with waste yarn.

After the above-mentioned wiped leather piece was dried in an environment of 90 ° C for 1 hour, the leather piece was horizontally fixed, and then the canvas was placed on the surface of the above-mentioned skin layer, and rubbed repeatedly under the condition of applying 500 g of weight. The surface of the epidermis.

The evaluation was carried out based on the following evaluation criteria based on the number of rubbing times at the time of rubbing and the appearance of the above-mentioned skin layer. Practically, it is preferable that the above evaluation is "C" The above is particularly good for "B" or above.

The exact number of frictions is unknown. (during every 1000 inspections)

A; the number of rubbing was 5000 times, and the skin layer of the leather piece was not peeled off.

B; the number of rubbing was 5000 times, the skin layer of the leather piece peeled off and the substrate was exposed.

C; the number of rubbing was 4000 times, the skin layer of the leather piece peeled off and the substrate was exposed.

D; the number of rubbing was 3,000 times, the skin layer of the leather piece peeled off and the substrate was exposed.

E; before the rubbing or the number of rubbing is less than 5 times, the skin layer of the leather sample peels off, and the substrate is exposed.

[Evaluation method of oil resistance]

The filter paper of the sunscreen oil (BUG SUN; COPPERTORN) having the same quality as that of the dried filter paper was placed on the skin layer constituting the leather sample obtained in the above examples and comparative examples, at 70 ° C. Heat for 24 hours.

After heating, the above filter paper was removed, and the sunscreen oil adhering to the surface of the above skin layer was wiped with waste yarn.

The surface of the skin layer after the above wiping was visually observed, and evaluated according to the following evaluation criteria.

A; no change in appearance and no peeling of the skin layer as compared with before the sunscreen was attached.

B; Compared with before the sunscreen oil is attached, a little swelling (swelling of the skin layer) is seen on a very small part in appearance, but it is practically The level of the problem did not reveal the peeling of the epidermis.

C; Swelling (swelling of the skin layer) which was clearly confirmed was observed in appearance as compared with before the adhesion of the sunscreen oil, but peeling of the skin layer was not observed.

D; The swelling which is clearly confirmed (the swelling of the skin layer) was observed in appearance, and the peeling of the part of the skin layer was seen, compared with before the adhesion of the sunscreen.

E; most of the epidermal layer is stripped or dissolved.

[Method for evaluating bending resistance]

The number of times before the surface of the leather piece was cracked was measured at -10 ° C using a bending tester (flexometer).

The exact number of bends is unknown. (because it is checked every time the specified number of times)

A; no cracking occurred on the surface of the leather sample at the time of the bending of 100,000 times.

B; cracks occurred on the surface of the leather sample at the time of the bending of 75,000 times.

C; cracks occurred on the surface of the leather sample at the time of the bending of 50,000 times.

D; at the time of the bending of 25,000 times, cracks were generated on the surface of the leather sample.

E; cracks occurred on the surface of the leather sample at the time of the bending of 10,000 times.

The leather plaques obtained in Examples 1 and 2 each had a skin layer excellent in sweat resistance or oil resistance, and cracks were not generated even when they were bent. Further, the leather plaques obtained in Examples 3 and 4 had a small proportion of the polycarbonate structure or the polycarbonate structure, and thus slightly decreased in the above-mentioned sweat resistance 2, but had good sweat resistance and Excellent oil resistance and bending resistance. In addition, the leather sample obtained in Example 5 although the hydroxyl value of the urethane resin constituting the skin layer thereof was slightly cited However, it has good sweat resistance, oil resistance and bending resistance.

On the other hand, the leather plaques obtained in Comparative Example 1 and Comparative Example 2 were exemplified by using a urethane resin having one hydroxyl group at one end as a urethane resin constituting the skin layer thereof. A significant decrease in sweat resistance and oil resistance is produced. Further, the leather plaque obtained in Comparative Example 3 was exemplified by using a urethane resin having no hydroxyl group at the terminal as a urethane resin constituting the skin layer thereof, and produced sweat resistance and oil resistance. Significant decline.

Claims (4)

A leather swatch characterized by comprising a skin layer (C) formed using a urethane resin composition containing at least one terminal having at least two hydroxyl groups. a urethane resin (A) and an aqueous medium (B); an adhesive layer (D); and a support layer (E); wherein the urethane resin (A) is obtained by containing a polycarbonate polyol a resin obtained by reacting a polyol (a1) and a polyisocyanate (a2); the aqueous medium (B) comprising: water, an organic solvent mixed with water, and a mixture thereof; the adhesive layer (D) Is a layer formed using an adhesive (d) containing a compound (d-1) having a hydroxyl group and a compound (d-2) having an isocyanate group, and the isocyanate group of the compound (d-2) The equivalent ratio [isocyanate group/hydroxy group] to the hydroxyl group of the above compound (d-1) is in a range of more than 1.0. The leather sample according to claim 1, wherein the urethane resin (A) is a resin obtained by subjecting a polyol (a1) containing a polycarbonate polyol to a polyisocyanate. (a2) and a chain extender (a3) are reacted, thereby obtaining a urethane prepolymer having an isocyanate group at both terminals, and then, the isocyanate group of the above urethane prepolymer is The amine group possessed by the polyalkanolamine is reacted. The leather sample according to claim 1, wherein a part or all of the isocyanate group of the compound (d-2) and the urethane resin (A) contained in the skin layer (C) are used. The hydroxyl group is reacted to form a urethane bond. A method for producing a leather plaque, characterized in that a urethane resin composition containing at least one urethane resin (A) having two or more hydroxyl groups at the terminal end and an aqueous medium (B) is coated After being coated on the release paper and dried, the adhesive (d) is applied onto the coated surface of the release paper, and then the support is placed on the coated surface of the adhesive (d), and Heating, wherein the adhesive (d) contains a compound (d-1) having a hydroxyl group and a compound (d-2) having an isocyanate group, and the isocyanate group of the compound (d-2), and the above The equivalent ratio of the hydroxyl group of the compound (d-1) [isocyanate group/hydroxy group] is in the range of more than 1.0.