JP2011241266A - Leather-like sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a leather-like sheet configured by using a nonwoven fabric made from an aliphatic polyester resin composition, wherein the aliphatic polyester resin composition is improved in hydrolysis resistance and does not generate a free isocyanate compound at the time of fusion or the like.SOLUTION: The leather-like sheet comprises the nonwoven fabric and a polymer elastomer. The nonwoven fabric consists of fiber that comprises the aliphatic polyester resin composition containing a compound (C component). The compound (C component) has one carbodiimide group and has a cyclic structure in which first and second nitrogens of the carbodiimide group are each bonded to a bonding group.

Description

  The present invention relates to a leather-like sheet comprising a nonwoven fabric and a polymer elastic body. More specifically, the present invention relates to a leather-like structure in which a non-woven fabric composed of fibers comprising an aliphatic polyester resin composition with improved hydrolysis resistance is used as a base material, and a polymer elastic body is applied to the base material. Regarding the sheet.

  In recent years, with increasing awareness of the environment on a global scale, polylactic acid synthesized from raw materials derived from plant-derived components has attracted attention. Polylactic acid is a polymer made from lactic acid obtained by fermenting starch or cellulose extracted from plants. Among plant-derived polymers, the balance of mechanical properties, heat resistance, and cost is excellent. Development of resin products, fibers, films, sheets, and the like using this has been performed.

  Of these, polylactic acid fibers have been proposed to be used as a base material for leather-like sheets that are suitable for use in household goods such as shoes, bags and accessories, as well as interior items such as sofa upholstery materials and clothing. (See, for example, Patent Document 1).

  However, this proposal is intended to decompose the obtained leather-like sheet in soil or compost. Polylactic acid is prone to hydrolysis, so its product life is short, and there is a problem that application development is restricted as it is, and the leather-like sheet obtained by the above proposal also has a problem in durability, When manufacturing a leather-like sheet, the fiber may be subjected to a treatment under high-temperature and high-humidity conditions, which is not practical.

  On the other hand, in order to improve the hydrolysis resistance of biodegradable plastics, particularly aliphatic polyesters typified by polylactic acid, polylactic acid with improved hydrolysis resistance by adding a carbodiimide compound or the like has also been proposed. (For example, Patent Document 2). However, when the carbodiimide compound used is used as an end-capping agent for a polymer compound, the compound having an isocyanate group is liberated as the carbodiimide compound binds to the end of polylactic acid, generating a unique odor of the isocyanate compound. However, deteriorating the working environment has been a problem.

JP 2001-214380 A Japanese Patent No. 3776578

  The object of the present invention is to solve the above-mentioned problems of the prior art, improve hydrolysis resistance, and further comprises an aliphatic polyester resin composition that does not generate free isocyanate compounds when melted. It is providing the leather-like sheet | seat using a nonwoven fabric.

  As a result of intensive investigations on the improvement of hydrolysis resistance of aliphatic polyester resins and further improvement of working environment, the present inventors have found that even if the aliphatic polyester resin reacts with the polymer chain end of the polyester, It has been found that the above object can be achieved when a carbodiimide compound having a specific structure that does not liberate a compound is contained, and the present invention has been completed.

That is, the object of the present invention is to
Nonwoven fabric composed of fibers made of an aliphatic polyester resin composition containing a compound (component C) containing a cyclic structure in which one carbodiimide group and the first nitrogen and the second nitrogen are bonded by a bonding group And a leather-like sheet comprising a polymer elastic body.

ADVANTAGE OF THE INVENTION According to this invention, the leather-like sheet | seat which consists of an aliphatic polyester resin with improved hydrolysis resistance can be provided.
Furthermore, the polymer terminal of the aliphatic polyester resin can be sealed with a carbodiimide compound without releasing the isocyanate compound. As a result, the generation of malodor due to the free isocyanate compound can be suppressed, and the working environment can be improved.

  Further, when the end of the aliphatic polyester resin is sealed with a cyclic carbodiimide compound, an isocyanate group is formed at the end of the aliphatic polyester resin, and the high molecular weight of the polyester becomes possible by the reaction of the isocyanate group. The cyclic carbodiimide compound also has an action of capturing a free monomer and other compounds having an acidic group in the aliphatic polyester resin. Furthermore, according to the present invention, the cyclic carbodiimide compound has an advantage that it can be end-capped under milder conditions as compared with a linear carbodiimide compound that is usually used by having a cyclic structure.

The difference between the linear carbodiimide compound and the cyclic carbodiimide compound in the end-capping reaction mechanism is as described below.
When a linear carbodiimide compound (R ₁ —N═C═N—R ₂ ) is used as a carboxyl terminal blocking agent of an aliphatic polyester resin, the reaction is represented by the following formula. When the linear carbodiimide compound reacts with a carboxyl group, an amide group is formed at the end of the aliphatic polyester resin, and an isocyanate compound (R ₁ NCO) is released.

（式中、Ｗはポリエステルの主鎖である。）

(Wherein, W is the main chain of the polyester.)

  On the other hand, when a cyclic carbodiimide compound is used as a carboxyl terminal blocking agent of an aliphatic polyester resin, the reaction is represented by the following formula. It can be seen that when the cyclic carbodiimide compound reacts with a carboxyl group, an isocyanate group (—NCO) is formed at the terminal of the aliphatic polyester resin via an amide group, and the isocyanate compound is not liberated.

（式中、Ｗは脂肪族ポリエステル樹脂の主鎖であり、Ｑは、脂肪族基、脂環族基、芳香族基またはこれらの組み合わせである２〜４価の結合基である。）

(Wherein, W is the main chain of the aliphatic polyester resin, and Q is a divalent to tetravalent linking group that is an aliphatic group, an alicyclic group, an aromatic group, or a combination thereof.)

<Cyclic carbodiimide compound (component C)>
In the present invention, the cyclic carbodiimide compound (C component) has a cyclic structure. The cyclic carbodiimide compound may have a plurality of cyclic structures.
The cyclic structure has one carbodiimide group (—N═C═N—), and the first nitrogen and the second nitrogen are bonded by a bonding group. One cyclic structure has only one carbodiimide group. For example, when there are a plurality of cyclic structures in the molecule, such as a spiro ring, one cyclic structure bonded to a spiro atom is included in each cyclic structure. Needless to say, the compound may have a plurality of carbodiimide groups as long as it has a carbodiimide group. The number of atoms in the cyclic structure is preferably 8 to 50, more preferably 10 to 30, further preferably 10 to 20, and particularly preferably 10 to 15.

  Here, the number of atoms in the ring structure means the number of atoms that directly constitute the ring structure, and is, for example, 8 for an 8-membered ring and 50 for a 50-membered ring. This is because if the number of atoms in the cyclic structure is smaller than 8, the stability of the cyclic carbodiimide compound is lowered, and it may be difficult to store and use. From the viewpoint of reactivity, there is no particular restriction on the upper limit of the number of ring members, but cyclic carbodiimide compounds having more than 50 atoms are difficult to synthesize, and the cost may increase significantly. From this viewpoint, the number of atoms in the cyclic structure is preferably 10-30, more preferably 10-20, and particularly preferably 10-15.

The cyclic structure is preferably a structure represented by the following formula (1).

  In the formula, Q is a divalent to tetravalent linking group that is an aliphatic group, an alicyclic group, an aromatic group, or a combination thereof, each of which may contain a hetero atom and a substituent. A heteroatom in this case refers to O, N, S, P. Two of the valences of this linking group are used to form a cyclic structure. When Q is a trivalent or tetravalent linking group, it is bonded to a polymer or other cyclic structure via a single bond, a double bond, an atom, or an atomic group.

  The linking group may include a heteroatom and a substituent, each having a divalent to tetravalent carbon number of 1 to 20 aliphatic group, a divalent to tetravalent carbon number of 3 to 20 alicyclic group, A linking group which is a tetravalent aromatic group having 5 to 15 carbon atoms or a combination thereof and has a necessary number of carbon atoms to form the cyclic structure defined above is selected. Examples of combinations include structures such as an alkylene-arylene group in which an alkylene group and an arylene group are bonded.

The linking group (Q) is preferably a divalent to tetravalent linking group represented by the following formula (1-1), (1-2) or (1-3).

In the formula, Ar ¹ and Ar ² are each independently a 2- to 4-valent aromatic group having 5 to 15 carbon atoms which may contain a hetero atom and a substituent.
As an aromatic group, each of which contains a hetero atom and may have a heterocyclic structure, an arylene group having 5 to 15 carbon atoms, an arenetriyl group having 5 to 15 carbon atoms, an arenetetra having 5 to 15 carbon atoms Yl group. Examples of the arylene group (divalent) include a phenylene group and a naphthalenediyl group. Examples of the arenetriyl group (trivalent) include a benzenetriyl group and a naphthalenetriyl group. Examples of the arenetetrayl group (tetravalent) include a benzenetetrayl group and a naphthalenetetrayl group. These aromatic groups may be substituted. Examples of the substituent include an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 15 carbon atoms, a halogen atom, a nitro group, an amide group, a hydroxyl group, an ester group, an ether group, and an aldehyde group.

R ¹ and R ² each independently contain a heteroatom and a substituent, each having 2 to 4 valent aliphatic groups having 1 to 20 carbon atoms and 2 to 4 valent fatty acids having 3 to 20 carbon atoms A cyclic group, and a combination thereof, or a combination of the aliphatic group, the alicyclic group, and a divalent to tetravalent aromatic group having 5 to 15 carbon atoms.

  Examples of the aliphatic group include an alkylene group having 1 to 20 carbon atoms, an alkanetriyl group having 1 to 20 carbon atoms, and an alkanetetrayl group having 1 to 20 carbon atoms. Examples of the alkylene group include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group, a nonylene group, a decylene group, a dodecylene group, and a hexadecylene group. As the alkanetriyl group, methanetriyl group, ethanetriyl group, propanetriyl group, butanetriyl group, pentanetriyl group, hexanetriyl group, heptanetriyl group, octanetriyl group, nonanetriyl group, decantriyl group, dodecantriyl group, Examples include a hexadecantriyl group. As alkanetetrayl group, methanetetrayl group, ethanetetrayl group, propanetetrayl group, butanetetrayl group, pentanetetrayl group, hexanetetrayl group, heptanetetrayl group, octanetetrayl group, nonanetetrayl group Decanetetrayl group, dodecanetetrayl group, hexadecanetetrayl group and the like. These aliphatic groups may be substituted. Examples of the substituent include an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 15 carbon atoms, a halogen atom, a nitro group, an amide group, a hydroxyl group, an ester group, an ether group, and an aldehyde group.

  Examples of the alicyclic group include a cycloalkylene group having 3 to 20 carbon atoms, a cycloalkanetriyl group having 3 to 20 carbon atoms, and a cycloalkanetetrayl group having 3 to 20 carbon atoms. Examples of the cycloalkylene group include a cyclopropylene group, a cyclobutylene group, a cyclopentylene group, a cyclohexylene group, a cycloheptylene group, a cyclooctylene group, a cyclononylene group, a cyclodecylene group, a cyclododecylene group, and a cyclohexadecylene group. As cycloalkanetriyl group, cyclopropanetriyl group, cyclobutanetriyl group, cyclopentanetriyl group, cyclohexanetriyl group, cycloheptanetriyl group, cyclooctanetriyl group, cyclononanetriyl group, cyclodecanetriyl group Group, cyclododecane triyl group, cyclohexadecane triyl group and the like. As cycloalkanetetrayl group, cyclopropanetetrayl group, cyclobutanetetrayl group, cyclopentanetetrayl group, cyclohexanetetrayl group, cycloheptanetetrayl group, cyclooctanetetrayl group, cyclononanetetrayl group, cyclodecanetetrayl group Yl group, cyclododecanetetrayl group, cyclohexadecanetetrayl group and the like. These alicyclic groups may be substituted. Examples of the substituent include an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 15 carbon atoms, a halogen atom, a nitro group, an amide group, a hydroxyl group, an ester group, an ether group, and an aldehyde group.

  As an aromatic group, each of which contains a hetero atom and may have a heterocyclic structure, an arylene group having 5 to 15 carbon atoms, an arenetriyl group having 5 to 15 carbon atoms, an arenetetra having 5 to 15 carbon atoms Yl group. Examples of the arylene group include a phenylene group and a naphthalenediyl group. Examples of the arenetriyl group (trivalent) include a benzenetriyl group and a naphthalenetriyl group. Examples of the arenetetrayl group (tetravalent) include a benzenetetrayl group and a naphthalenetetrayl group. These aromatic groups may be substituted. Examples of the substituent include an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 15 carbon atoms, a halogen atom, a nitro group, an amide group, a hydroxyl group, an ester group, an ether group, and an aldehyde group.

X ¹ and X ² each independently contain a heteroatom and a substituent, each having a 2 to 4 valent aliphatic group having 1 to 20 carbon atoms and a 2 to 4 valent fatty acid having 3 to 20 carbon atoms It is a cyclic group, a divalent to tetravalent aromatic group having 5 to 15 carbon atoms, or a combination thereof.

  Examples of the aliphatic group include an alkylene group having 1 to 20 carbon atoms, an alkanetriyl group having 1 to 20 carbon atoms, and an alkanetetrayl group having 1 to 20 carbon atoms. Examples of the alkylene group include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group, a nonylene group, a decylene group, a dodecylene group, and a hexadecylene group. As the alkanetriyl group, methanetriyl group, ethanetriyl group, propanetriyl group, butanetriyl group, pentanetriyl group, hexanetriyl group, heptanetriyl group, octanetriyl group, nonanetriyl group, decantriyl group, dodecantriyl group, Examples include a hexadecantriyl group. As alkanetetrayl group, methanetetrayl group, ethanetetrayl group, propanetetrayl group, butanetetrayl group, pentanetetrayl group, hexanetetrayl group, heptanetetrayl group, octanetetrayl group, nonanetetrayl group Decanetetrayl group, dodecanetetrayl group, hexadecanetetrayl group and the like. These aliphatic groups may be substituted. Examples of the substituent include an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 15 carbon atoms, a halogen atom, a nitro group, an amide group, a hydroxyl group, an ester group, an ether group, and an aldehyde group.

  Examples of the alicyclic group include a cycloalkylene group having 3 to 20 carbon atoms, a cycloalkanetriyl group having 3 to 20 carbon atoms, and a cycloalkanetetrayl group having 3 to 20 carbon atoms. Examples of the cycloalkylene group include a cyclopropylene group, a cyclobutylene group, a cyclopentylene group, a cyclohexylene group, a cycloheptylene group, a cyclooctylene group, a cyclononylene group, a cyclodecylene group, a cyclododecylene group, and a cyclohexadecylene group. As the alkanetriyl group, cyclopropanetriyl group, cyclobutanetriyl group, cyclopentanetriyl group, cyclohexanetriyl group, cycloheptanetriyl group, cyclooctanetriyl group, cyclononanetriyl group, cyclodecanetriyl group , Cyclododecanetriyl group, cyclohexadecanetriyl group and the like. As the alkanetetrayl group, cyclopropanetetrayl group, cyclobutanetetrayl group, cyclopentanetetrayl group, cyclohexanetetrayl group, cycloheptanetetrayl group, cyclooctanetetrayl group, cyclononanetetrayl group, cyclodecanetetrayl group Group, cyclododecanetetrayl group, cyclohexadecanetetrayl group and the like. These alicyclic groups may be substituted. Examples of the substituent include an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 15 carbon atoms, a halogen atom, a nitro group, an amide group, a hydroxyl group, an ester group, an ether group, and an aldehyde group.

  As an aromatic group, each of which contains a hetero atom and may have a heterocyclic structure, an arylene group having 5 to 15 carbon atoms, an arenetriyl group having 5 to 15 carbon atoms, an arenetetra having 5 to 15 carbon atoms Yl group. Examples of the arylene group include a phenylene group and a naphthalenediyl group. Examples of the arenetriyl group (trivalent) include a benzenetriyl group and a naphthalenetriyl group. Examples of the arenetetrayl group (tetravalent) include a benzenetetrayl group and a naphthalenetetrayl group. These aromatic groups may be substituted. Examples of the substituent include an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 15 carbon atoms, a halogen atom, a nitro group, an amide group, a hydroxyl group, an ester group, an ether group, and an aldehyde group.

In the formulas (1-1) and (1-2), s and k are integers of 0 to 10, preferably 0 to 3, more preferably 0 to 1. When s and k exceed 10, the cyclic carbodiimide compound is difficult to synthesize, and the cost may increase significantly. From this viewpoint, the integer is preferably selected in the range of 0 to 3. When s or k is 2 or more, X ¹ or X ² as a repeating unit may be different from other X ¹ or X ² .

X ³ is a divalent to tetravalent C 1-20 aliphatic group, a divalent to tetravalent C 3-20 alicyclic group, each of which may contain a heteroatom and a substituent, A tetravalent aromatic group having 5 to 15 carbon atoms, or a combination thereof.

  Examples of the aliphatic group include an alkylene group having 1 to 20 carbon atoms, an alkanetriyl group having 1 to 20 carbon atoms, and an alkanetetrayl group having 1 to 20 carbon atoms. Examples of the alkylene group include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group, a nonylene group, a decylene group, a dodecylene group, and a hexadecylene group. As the alkanetriyl group, methanetriyl group, ethanetriyl group, propanetriyl group, butanetriyl group, pentanetriyl group, hexanetriyl group, heptanetriyl group, octanetriyl group, nonanetriyl group, decantriyl group, dodecantriyl group, Examples include a hexadecantriyl group. As alkanetetrayl group, methanetetrayl group, ethanetetrayl group, propanetetrayl group, butanetetrayl group, pentanetetrayl group, hexanetetrayl group, heptanetetrayl group, octanetetrayl group, nonanetetrayl group Decanetetrayl group, dodecanetetrayl group, hexadecanetetrayl group and the like. These aliphatic groups may contain a substituent, such as an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 15 carbon atoms, a halogen atom, a nitro group, an amide group, a hydroxyl group, or an ester group. , Ether group, aldehyde group and the like.

  Examples of the alicyclic group include a cycloalkylene group having 3 to 20 carbon atoms, a cycloalkanetriyl group having 3 to 20 carbon atoms, and a cycloalkanetetrayl group having 3 to 20 carbon atoms. Examples of the cycloalkylene group include a cyclopropylene group, a cyclobutylene group, a cyclopentylene group, a cyclohexylene group, a cycloheptylene group, a cyclooctylene group, a cyclononylene group, a cyclodecylene group, a cyclododecylene group, and a cyclohexadecylene group. As the alkanetriyl group, cyclopropanetriyl group, cyclobutanetriyl group, cyclopentanetriyl group, cyclohexanetriyl group, cycloheptanetriyl group, cyclooctanetriyl group, cyclononanetriyl group, cyclodecanetriyl group , Cyclododecanetriyl group, cyclohexadecanetriyl group and the like. As the alkanetetrayl group, cyclopropanetetrayl group, cyclobutanetetrayl group, cyclopentanetetrayl group, cyclohexanetetrayl group, cycloheptanetetrayl group, cyclooctanetetrayl group, cyclononanetetrayl group, cyclodecanetetrayl group Group, cyclododecanetetrayl group, cyclohexadecanetetrayl group and the like. These alicyclic groups may contain a substituent, such as an alkyl group having 1 to 20 carbon atoms, an arylene group having 6 to 15 carbon atoms, a halogen atom, a nitro group, an amide group, a hydroxyl group, and an ester. Group, ether group, aldehyde group and the like.

  As an aromatic group, each of which contains a hetero atom and may have a heterocyclic structure, an arylene group having 5 to 15 carbon atoms, an arenetriyl group having 5 to 15 carbon atoms, an arenetetra having 5 to 15 carbon atoms Yl group. Examples of the arylene group include a phenylene group and a naphthalenediyl group. Examples of the arenetriyl group (trivalent) include a benzenetriyl group and a naphthalenetriyl group. Examples of the arenetetrayl group (tetravalent) include a benzenetetrayl group and a naphthalenetetrayl group. These aromatic groups may be substituted. Examples of the substituent include an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 15 carbon atoms, a halogen atom, a nitro group, an amide group, a hydroxyl group, an ester group, an ether group, and an aldehyde group.

Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ² and X ³ may contain a hetero atom, and when Q is a divalent linking group, Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ² and X ³ are all divalent groups. When Q is a trivalent linking group, one of Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ² and X ³ is a trivalent group. When Q is a tetravalent linking group, one of Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ² and X ³ is a tetravalent group or two are trivalent It is a group.

  Examples of the cyclic carbodiimide compound used in the present invention include compounds represented by the following formulas (2) to (4).

<Cyclic carbodiimide compound (2)>

  In the formula, Qa is a divalent linking group that is an aliphatic group, an alicyclic group, an aromatic group, or a combination thereof, and may contain a heteroatom. The aliphatic group, alicyclic group, and aromatic group are the same as those described in Formula (1). However, in the compound of formula (2), the aliphatic group, alicyclic group, and aromatic group are all divalent. Qa is preferably a divalent linking group represented by the following formula (2-1), (2-2) or (2-3).

In the formula, Ar _a ¹ , Ar _a ² , R _a ¹ , R _a ² , X _a ¹ , X _a ² , X _a ³ , s and k are represented by formulas (1-1) to (1-3), respectively. Are the same as Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ² , X ³ , s and k. However, these are all divalent.
Examples of the cyclic carbodiimide compound (2) include the following compounds.

<Cyclic carbodiimide compound (3)>

Wherein, Q _b is an aliphatic group, an alicyclic group, an aromatic group or a trivalent linking group combinations thereof, and may contain a hetero atom. Y is a carrier supporting a cyclic structure. The aliphatic group, alicyclic group, and aromatic group are the same as those described in Formula (1). However, in the compound of formula (3), one of the groups constituting Qb is trivalent. Q _b is preferably a trivalent linking group represented by the following formula (3-1), (3-2) or (3-3).

In the formula, Ar _b ¹ , Ar _b ² , R _b ¹ , R _b ² , X _b ¹ , X _b ² , X _b ³ , s and k are respectively represented by the formulas (1-1) to (1-3). The same as Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ² , X ³ , s and k. However, one of these is a trivalent group.

  Y is preferably a single bond, a double bond, an atom, an atomic group or a polymer. Y is a bonding portion, and a plurality of cyclic structures are bonded via Y to form a structure represented by the formula (3). Examples of the cyclic carbodiimide compound (3) include the following compounds.

<Cyclic carbodiimide compound (4)>

In the formula, Q _c is a tetravalent linking group which is an aliphatic group, an alicyclic group, an aromatic group, or a combination thereof, and may have a hetero atom. Z ¹ and Z ² are carriers that support a cyclic structure. Z ¹ and Z ² may be bonded to each other to form a cyclic structure.

The aliphatic group, alicyclic group, and aromatic group are the same as those described in Formula (1). However, in the compound of formula (4), Q _c is tetravalent. Accordingly, one of these groups is a tetravalent group or two are trivalent groups. Q _c is preferably a tetravalent linking group represented by the following formula (4-1), (4-2) or (4-3).

Ar _c ¹ , Ar _c ² , R _c ¹ , R _c ² , X _c ¹ , X _c ² , X _c ³ , s and k are each Ar ^{1 in} formulas (1-1) to (1-3). , Ar ² , R ¹ , R ² , X ¹ , X ² , X ³ , s and k are the same. Provided that Ar _c ¹ , Ar _c ² , R _c ¹ , R _c ² , X _c ¹ , X _c ² and X _c ³ are one of which is a tetravalent group or two of which are trivalent It is a group.
Z ¹ and Z ² are preferably each independently a single bond, a double bond, an atom, an atomic group or a polymer. Z ¹ and Z ² are bonding portions, and a plurality of cyclic structures are bonded via Z ¹ and Z ² to form a structure represented by the formula (4).
Examples of the cyclic carbodiimide compound (4) include the following compounds.

<Method for producing cyclic carbodiimide compound>
The cyclic carbodiimide compound can be produced by a conventionally known method. For example, a method for producing an amine body via an isocyanate body, a method for producing an amine body via an isothiocyanate body, a method for producing an amine body via a triphenylphosphine body, a urea body from an amine body The method of manufacturing via a thiourea body, the method of manufacturing via a thiourea body, the method of manufacturing from a carboxylic acid body via an isocyanate body, the method of manufacturing a lactam body, etc. are mentioned.

  Moreover, the cyclic carbodiimide compound of this invention can be manufactured combining and changing the method described in the following literatures, and an appropriate method can be employ | adopted according to the compound to manufacture.

Tetrahedron Letters, Vol. 34, no. 32, 515-5158, 1993.
Medium- and Large-Membered Rings from Bis (iminophosphoranes): An Efficient Preparation of Cyclic Carbidiimides, Pedro Molina et al.
Journal of Organic Chemistry, Vol. 61, no. 13, 4289-4299, 1996.
New Models for the Study of the Racemization Mechanism of Carbodiimides. Synthesis and Structure (X-ray Crystallography and 1H NMR) of Cyclic Carbodiimides, Pedro Molina et al.
Journal of Organic Chemistry, Vol. 43, No8, 1944-1946, 1978.
Macrocyclic Ureas As Masked Isocynates, Henri Ulrich et al.
Journal of Organic Chemistry, Vol. 48, no. 10, 1694-1700, 1983.
Synthesis and Reactions of Cyclic Carbodiimides,
R. Richter et al.
Journal of Organic Chemistry, Vol. 59, no. 24, 7306-7315, 1994.
A New and Efficient Preparation of Cyclic Carbodiamids from Bis (iminophosphoranea) and the System Boc ₂ O / DMAP, Pedro Molina et al.

（２）得られたニトロ体を還元して下記式（ｄ）で表わされるアミン体を得る工程、

（３）得られたアミン体とトリフェニルホスフィンジブロミドを反応させ下記式（ｅ）で表されるトリフェニルホスフィン体を得る工程、および

（４）得られたトリフェニルホスフィン体を反応系中でイソシアネート化した後、直接脱炭酸させることによって製造したものは、本願発明に用いる環状カルボジイミド化合物として好適に用いることができる。 Depending on the compound to be produced, an appropriate production method may be employed. For example, (1) nitrophenol represented by the following formula (a-1), nitrophenol represented by the following formula (a-2), and A step of reacting a compound represented by the following formula (b) to obtain a nitro compound represented by the following formula (c);

(2) A step of reducing the obtained nitro body to obtain an amine body represented by the following formula (d);

(3) a step of reacting the obtained amine body with triphenylphosphine dibromide to obtain a triphenylphosphine body represented by the following formula (e); and

(4) After the obtained triphenylphosphine body is isocyanated in the reaction system and then directly decarboxylated, it can be suitably used as the cyclic carbodiimide compound used in the present invention.

(In the above formula, Ar ¹ and Ar ² are each independently an aromatic group optionally substituted with an alkyl group having 1 to 6 carbon atoms or a phenyl group. E ¹ and E ² are each independently a halogen atom. A group selected from the group consisting of an atom, a toluenesulfonyloxy group, a methanesulfonyloxy group, a benzenesulfonyloxy group, and a p-bromobenzenesulfonyloxy group, Ar ^a is a phenyl group, X is represented by the following formula (i -1) to (i-3).

（式中、ｎは１〜６の整数である。）

(In the formula, n is an integer of 1 to 6.)

（式中、ｍおよびｎは各々独立に０〜３の整数である。）

(In the formula, m and n are each independently an integer of 0 to 3.)

（式中、Ｒ^１およびＲ^２は各々独立に、炭素数１〜６のアルキル基、フェニル基を表す。）

(In the formula, R ¹ and R ² each independently represents an alkyl group having 1 to 6 carbon atoms or a phenyl group.)

<Aliphatic polyester resin>
In the present invention, the aliphatic polyester resin includes a polymer having an aliphatic hydroxycarboxylic acid as a main constituent, an aliphatic polyvalent carboxylic acid or an ester-forming derivative thereof, and an aliphatic polyhydric alcohol as main components. And the copolymers thereof are exemplified.

  Examples of the polymer having aliphatic hydroxycarboxylic acid as a main constituent component include polycondensates such as glycolic acid, lactic acid, hydroxypropionic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxycaproic acid, and copolymers. Among them, polyglycolic acid, polylactic acid, poly-3-hydroxycarboxylic butyric acid, poly-4-polyhydroxybutyric acid, poly-3-hydroxyhexanoic acid or polycaprolactone, and copolymers thereof may be mentioned. It can be suitably used for lactic acid, poly-D-lactic acid, stereocomplex polylactic acid forming a stereocomplex crystal, and racemic polylactic acid.

  The polylactic acid may be one having L-lactic acid and / or D-lactic acid as the main repeating unit, and particularly preferably has a melting point of 150 ° C. or higher (here, the main is Means that the component occupies 50% or more). When the melting point is lower than 150 ° C., the dimensional stability and high-temperature mechanical properties of the resulting fiber cannot be improved.

  Poly L monolactic acid and poly D-lactic acid can be produced by a conventionally known method. For example, L- or D-lactide can be heated in the presence of a metal-containing catalyst and produced by ring-opening polymerization. In addition, after crystallizing a low molecular weight polylactic acid containing a metal-containing catalyst, it is heated under reduced pressure or pressure, in the presence or absence of an inert gas stream. It can also be produced by solid phase polymerization. Further, it can be produced by a direct polymerization method in which lactic acid is subjected to dehydration condensation in the presence / absence of an organic solvent.

  The polymerization reaction can be carried out in a conventionally known reaction vessel. For example, a vertical reactor or a horizontal reactor having a high-viscosity stirring blade such as a helical ribbon blade can be used alone or in parallel. . Moreover, any of a batch type, a continuous type, a semibatch type may be sufficient, and these may be combined.

  Alcohol may be used as a polymerization initiator. Such alcohol is preferably non-volatile without inhibiting the polymerization of polylactic acid. For example, decanol, dodecanol, tetradecanol, hexadecanol, octadecanol and the like can be suitably used.

  In the solid phase polymerization method, polylactic acid having a relatively low molecular weight (about 15 to 200) obtained by the above-described ring-opening polymerization method or direct polymerization method of lactic acid is used as a prepolymer. The prepolymer is preferably crystallized in advance in the temperature range of the glass transition temperature or higher and lower than the melting point from the viewpoint of preventing resin pellet fusion. The crystallized prepolymer is filled in a fixed vertical or horizontal reaction vessel, or a reaction vessel (such as a rotary kiln) in which the vessel itself rotates, such as a tumbler or kiln. Heated to a temperature range. There is no problem even if the polymerization temperature is increased in stages as the polymerization proceeds. In addition, for the purpose of efficiently removing water generated during solid phase polymerization, a method of reducing the pressure inside the reaction vessels or circulating a heated inert gas stream is also preferably used.

It is preferable to inactivate the metal-containing catalyst used during the polymerization of polylactic acid with a conventionally known deactivator prior to use, because the stability of polylactic acid and the resin composition to heat and moisture can be improved.
Examples of such a deactivator include an organic ligand having a group of chelate ligands having an imino group and capable of coordinating with a polymerized metal catalyst.

  Also, dihydridooxoline (I) acid, dihydridotetraoxodiphosphorus (II, II) acid, hydridotrioxoline (III) acid, dihydridopentaoxodiphosphoric acid (III), hydridopentaoxodi (II, IV) Acid, dodecaoxohexaphosphoric acid (III), hydridooctaoxotriphosphoric acid (III, IV, IV) acid, octaoxotriphosphoric acid (IV, III, IV) acid, hydridohexaoxodiphosphoric acid (III, V) acid, hexaoxodiacid Low oxidation number phosphoric acid having an acid number of 5 or less, such as phosphoric acid (IV), decaoxotetraphosphoric acid (IV), hedecaoxotetraphosphoric acid (IV), and eneoxooxophosphoric acid (V, IV, IV). .

Further, orthophosphoric acid represented by the formula xH ₂ O · yP ₂ O ₅ , x / y = 3, 2> x / y> 1, and diphosphoric acid, triphosphoric acid, tetraphosphoric acid, five Examples thereof include polyphosphoric acid called phosphoric acid and a mixture thereof.
Further, metaphosphoric acid represented by x / y = 1, in particular, trimetaphosphoric acid, tetrametaphosphoric acid, 1> x / y> 0, and ultralin having a network structure in which a part of the phosphorus pentoxide structure is left. Acid (these may be collectively referred to as metaphosphoric acid compounds).

  Moreover, acidic salts of these acids, monovalent and polyhydric alcohols, partial esters of polyalkylene glycols, complete esters, phosphono-substituted lower aliphatic carboxylic acid derivatives and the like can be mentioned.

  Metaphosphoric acid compounds include cyclic metaphosphoric acid condensed with about 3 to 200 phosphoric acid units, ultra-regional metaphosphoric acid having a three-dimensional network structure, or their (alkal metal salt, alkaline earth metal salt, onium salt). Include. Of these, cyclic sodium metaphosphate, ultra-region sodium metaphosphate, phosphono-substituted lower aliphatic carboxylic acid derivative dihexylphosphonoethyl acetate (hereinafter sometimes abbreviated as DHPA) and the like are preferably used.

Preferably, the melting point of polylactic acid is 170 ° C. or higher, more preferably 200 ° C. or higher. Here, the melting point means the peak temperature of the melting peak obtained by DSC measurement. In particular, in order to impart heat resistance, it is preferable that polylactic acid forms a stereocomplex phase crystal.
Here, the stereocomplex polylactic acid is a eutectic formed by a poly L lactic acid segment and a poly D lactic acid segment.

Stereocomplex phase crystals usually have a higher melting point than homophase crystals formed solely by poly L lactic acid or poly D lactic acid, so that even if they are contained in a slight amount, the effect of increasing heat resistance can be expected. This is remarkably exhibited when the amount of stereocomplex phase crystals is large relative to the amount of crystals. The stereocomplex crystallinity (S) according to the following formula is preferably 95% or more, and more preferably 100%.
S = [ΔHms / (ΔHmh + ΔHms)] × 100
(However, ΔHms is the melting enthalpy of stereocomplex phase crystals, and ΔHmh is the melting enthalpy of homophase polylactic acid crystals.)

In order to stably and highly advance the formation of stereocomplex polylactic acid crystals, a method of blending specific additives is preferably applied.
That is, for example, a technique of adding a metal phosphate metal salt represented by the following formula as a stereocomplex crystallization accelerator can be mentioned.

In the formula, R ¹¹ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ¹² and R ¹³ each independently represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and M ₁ represents Represents an alkali metal atom, an alkaline earth metal atom, a zinc atom or an aluminum atom, p represents 1 or 2, q represents 0 when M ₁ is an alkali metal atom, an alkaline earth metal atom or a zinc atom; When it is an atom, it represents 1 or 2.

In the formula, each of R ¹⁴ , R ¹⁵ and R ¹⁶ independently represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and M ₂ represents an alkali metal atom, an alkaline earth metal atom, a zinc atom or an aluminum atom. P represents 1 or 2, q represents 0 when M ₂ is an alkali metal atom, alkaline earth metal atom or zinc atom, and 1 or 2 when M ₂ is an aluminum atom.

M ₁ and M ₂ of the metal phosphate represented by the above two formulas are preferably Na, K, Al, Mg, Ca and Li, and in particular, Li, Al is the most among K, Na, Al and Li. It can be used suitably.
As these metal phosphates, trade names manufactured by ADEKA Corporation, “ADEKA STAB” NA-11, NA-71 and the like are exemplified as suitable agents.

  The metal phosphate is used in an amount of 0.001 to 2 wt%, preferably 0.005 to 1 wt%, more preferably 0.01 to 0.5 wt%, still more preferably 0.02 to 0.3 wt% with respect to polylactic acid. It is preferable. When the amount is too small, the effect of improving the stereocomplex crystallinity (S) is small, and when too large, the stereocomplex crystal melting point is lowered, which is not preferable.

Further, if desired, a known crystallization nucleating agent can be used in combination to enhance the action of the metal phosphate. Of these, calcium silicate, talc, kaolinite, and montmorillonite are preferably selected.
The amount of the crystallization nucleating agent used is selected in the range of 0.05 to 5 wt%, more preferably 0.06 to 2 wt%, and still more preferably 0.06 to 1 wt% with respect to polylactic acid.

  Polylactic acid may be obtained by any manufacturing method. For example, a polylactic acid production method includes a two-stage lactide method in which L-lactic acid and / or D-lactic acid is used as a raw material to form lactide, which is a cyclic dimer, and then ring-opening polymerization is performed. In addition, it can be suitably obtained by a generally known polymerization method such as a one-step direct polymerization method in which dehydration condensation is directly performed in a solvent using D-lactic acid as a raw material.

  In the production of polylactic acid, carboxylic acid groups may be contained, but the smaller the amount of carboxylic acid groups contained, the better. For these reasons, it is preferable to use, for example, ring-opened polymerization from lactide using an initiator other than water, or a polymer that has been chemically treated after polymerization to reduce carboxylic acid groups.

  The weight average molecular weight of polylactic acid is usually at least 50,000, preferably at least 100,000, preferably 100,000 to 300,000. When the average molecular weight is lower than 50,000, the strength properties of the film are lowered, which is not preferable. If it exceeds 300,000, the melt viscosity becomes too high and melt film formation may be difficult.

  The polylactic acid in the present invention may be a copolymerized polylactic acid obtained by copolymerizing other components having ester forming ability in addition to L-lactic acid and D-lactic acid. The copolymerizable component includes glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 4-hydroxyvaleric acid, hydroxycarboxylic acids such as 6-hydroxycaproic acid, ethylene glycol, propylene glycol, butanediol, neo Compounds containing a plurality of hydroxyl groups in the molecule such as pentyl glycol, polyethylene glycol, glycerin and pentaerythritol or derivatives thereof, compounds containing a plurality of carboxylic acid groups in the molecule such as adipic acid, sebacic acid and fumaric acid Or derivatives thereof. However, in order to maintain a high melting point and not impair the fiber strength, in this case, it is desirable that 70 mol% or more of the fibers are composed of lactic acid units.

  As will be described later, the leather-like sheet of the present invention uses a nonwoven fabric composed of an aliphatic polyester resin composition in which an aliphatic polyester resin and a cyclic carbodiimide are mixed, but the cyclic carbodiimide compound reacts with the end of the aliphatic polyester resin. Although the terminal is sealed, when an excess cyclic carbodiimide compound is present, it remains unreacted in the aliphatic polyester resin composition. At this time, the aliphatic polyester resin contains an aliphatic polyester resin whose end is sealed and a cyclic carbodiimide compound, but also contains an aliphatic woven ester whose end is not sealed depending on the degree of reaction of terminal modification. Sometimes.

In the aliphatic polyester resin composition constituting the fiber, the content of the cyclic carbodiimide compound remaining unreacted in the composition is 0.001 per 100 parts by weight of the fiber comprising the aliphatic polyester resin composition. -10 parts by weight, preferably 0.01-5 parts by weight, more preferably 0.1-1 part by weight.
If there is a cyclic carbodiimide compound that remains unreacted in the composition, the hydrolysis resistance can be further improved.

<Mixing of aliphatic polyester resin and cyclic carbodiimide compound>
The method of adding and mixing the cyclic carbodiimide compound to the aliphatic polyester resin is not particularly limited, and a method of adding a solution, a melt or a master batch of the aliphatic polyester resin to be applied, or dissolving the cyclic carbodiimide compound by a conventionally known method. Alternatively, a method in which a solid of an aliphatic polyester resin is brought into contact with a dispersed or melted liquid and a cyclic carbodiimide compound is permeated can be employed.

  When taking the method of adding as a master batch of a solution, a melt or an aliphatic polyester resin to be applied, it can be added using a conventionally known kneading apparatus. In kneading, a kneading method in a solution state or a kneading method in a molten state is preferable from the viewpoint of uniform kneading properties. The kneading apparatus is not particularly limited, and examples thereof include conventionally known vertical reaction vessels, mixing tanks, kneading tanks or uniaxial or multiaxial horizontal kneading apparatuses such as uniaxial or multiaxial ruders and kneaders. The kneading time is not particularly specified and depends on the kneading apparatus and the kneading temperature, but is selected from 0.1 minutes to 2 hours, preferably from 0.2 minutes to 1 hour, more preferably from 1 minute to 30 minutes.

As a solvent, what is inactive with respect to an aliphatic polyester resin and a cyclic carbodiimide compound can be used. In particular, a solvent is preferred to have affinity for both and at least partially dissolve both, or at least partially dissolve in both.
As such a solvent, for example, a hydrocarbon solvent, a ketone solvent, an ester solvent, an ether solvent, a halogen solvent, an amide solvent and the like can be used.

Examples of the hydrocarbon solvent include hexane, cyclohexane, benzene, toluene, xylene, heptane, decane and the like. Examples of the ketone solvent include acetone, methyl ethyl ketone, diethyl ketone, cyclohexanone, and isophorone. Examples of ester solvents include ethyl acetate, methyl acetate, ethyl succinate, methyl carbonate, ethyl benzoate, and diethylene glycol diacetate. Examples of the ether solvent include diethyl ether, dibutyl ether, tetrahydrofuran, dioxane, diethylene glycol dimethyl ether, triethylene glycol diethyl ether, diphenyl ether and the like. Examples of the halogen solvent include dichloromethane, chloroform, tetrachloromethane, dichloroethane, 1,1 ′, 2,2′-tetrachloroethane, chlorobenzene, dichlorobenzene and the like. Examples of amide solvents include formamide, dimethylformamide, dimethylacetamide, N-methylpyrrolidone and the like.
These solvents may be used alone or as a mixed solvent as desired.

  In the present invention, the solvent is applied in the range of 1 to 1,000 parts by weight per 100 parts by weight of the total of the aliphatic polyester resin and the cyclic carbodiimide compound. If the amount is less than 1 part by weight, there is no significance in applying the solvent. The upper limit of the amount of solvent used is not particularly limited, but is about 1,000 parts by weight from the viewpoints of operability and reaction efficiency.

  When adopting a method in which the solid of the aliphatic polyester resin is brought into contact with the liquid in which the cyclic carbodiimide compound is dissolved, dispersed or melted and the cyclic carbodiimide compound is infiltrated, the solid aliphatic in the carbodiimide dissolved in the solvent as described above. A method of bringing a polyester resin into contact, a method of bringing a solid aliphatic polyester resin into contact with a carbodiimide emulsion, and the like can be employed. As the contact method, a method of immersing an aliphatic polyester resin, a method of applying to an aliphatic polyester resin, a method of spraying, or the like can be suitably used.

  The sealing reaction with the cyclic carbodiimide compound is possible at a temperature of room temperature (25 ° C.) to about 300 ° C., but is more accelerated in the range of 50 to 250 ° C., more preferably 80 to 200 ° C. from the viewpoint of reaction efficiency. . In the state where the aliphatic polyester resin is melted, the reaction is more likely to proceed, but the reaction is preferably carried out at a temperature lower than 300 ° C. in order to suppress volatilization, decomposition, etc. of the cyclic carbodiimide compound. It is also effective to apply a solvent to lower the melting temperature of the aliphatic polyester resin and increase the stirring efficiency.

  Although the reaction proceeds sufficiently rapidly without a catalyst, a catalyst that accelerates the reaction can also be used. As a catalyst, the catalyst used with the conventional linear carbodiimide compound is applicable. These can be used alone or in combination of two or more. The addition amount of the catalyst is not particularly limited, but is preferably 0.001 to 1 part by weight, and 0.01 to 0.1 part by weight based on 100 parts by weight of the aliphatic polyester resin and the cyclic carbodiimide compound. Part is more preferable, and 0.02 to 0.1 part by weight is even more preferable.

<Method for producing leather-like sheet>
The leather-like sheet of the present invention comprises a non-woven fabric made of a fiber comprising an aliphatic polyester resin composition containing the above-described aliphatic polyester resin and a cyclic carbodiimide compound, and a polymer elastic body. For example, the following steps are combined. Can be obtained.

That is,
(A) A step of producing a raw cotton capable of generating ultrafine fibers obtained by drawing, crimping, and cutting after a fiber containing the above-described aliphatic polyester resin composition and capable of generating ultrafine fibers by composite spinning or blend spinning. ,
(B) A step of creating a nonwoven fabric by subjecting the raw cotton to card processing and cross-wrapping processing as necessary, and then performing entanglement / entanglement processing;
(C) From the fibers capable of generating ultrafine fibers, other than the aliphatic polyester resin composition used as the base material of the leather-like sheet is dissolved and removed, or peeled off by physical and chemical action, divided, and ultrafine fibers A step of applying a polymer elastic body to the non-woven fabric before and / or after forming, and substantially solidifying and solidifying the polymer elastic body;
(D) A step of performing raising treatment as necessary to form napped on the surface,
(E) A step of dyeing with a disperse dye or the like.

  In the present invention, the non-woven fabric used as the base material of the leather-like sheet preferably has a single fiber fineness of 3 dTex or less, more preferably 2 dTex or less, from the viewpoint of improving the texture of the resulting leather-like sheet. More preferably, it is a so-called ultrafine fiber of 1.5 dTex or less, particularly 1 dTex or less.

  Further, the main component of the fiber component constituting the leather-like sheet in the present invention is 0.5 dTex or less, preferably 0.3 dTex or less, more preferably 0.1 dTex or less, so that the leather-like sheet has softness and touch. It is possible to improve the appearance, and when the brushing process is performed to obtain a suede tone, the appearance is also good.

  As a method of obtaining such an ultrafine fiber, a method of directly obtaining a target ultrafine fiber, a method of once producing a fiber capable of generating a thick ultrafine fiber, and then generating a ultrafine fiber can be employed. From the viewpoint of easily obtaining the fiber and the flexibility of the obtained leather-like sheet, a method of once producing a fiber capable of generating a thick ultrafine fiber and then generating the ultrafine fiber can be preferably used.

  As such a method, for example, a method in which a plurality of polymers having different solubilities are compound-spun or mixed-spun to obtain fibers capable of expressing ultrafine fibers, and then at least one kind of polymer is removed to form ultrafine fibers, Alternatively, a method of dividing a separation-type composite fiber can be used.

  The composite form when spinning such fibers capable of developing ultrafine fibers is a side-by-side type in which polymers are bonded together, a multi-layer bonded type, a core-sheath composite type, or another polymer in an island shape The existing sea island type and multi-core core-sheath type can be obtained by composite spinning, and a blend type in which polymers are mixed in an alloy form can be obtained by blend spinning.

  The polymer to be removed is preferably a polymer having a lower melt viscosity and higher surface tension than the aliphatic polyester resin composition under the spinning conditions, and more soluble or decomposable than the aliphatic polyester resin composition. Any polymer that is large and has a low compatibility with the aliphatic polyester resin composition may be used.

As what satisfy | fills these conditions, polymers, such as polyethylene, a polystyrene, copolymerized polyethylene, thermoplastic polyvinyl alcohol, can be illustrated, for example. For example, polystyrene can be easily extracted from toluene, polyethylene can be easily extracted from trichlorethylene or the like, and thermoplastic polyvinyl alcohol can be decomposed and removed by hot water.
Then, by extracting or decomposing and removing these polymers, an ultrafine fiber bundle made of the aliphatic polyester resin composition can be obtained.

  Even if the nonwoven fabric using the ultrafine fiber generation type fiber is a short fiber nonwoven fabric using the fiber obtained by the above-described fiber manufacturing method, it is a length that is directly converted into a nonwoven fabric after melt spinning by the spunbond method. A fiber nonwoven fabric may be sufficient.

  In particular, in the case of a short fiber nonwoven fabric, the stretched fiber is crimped and made into raw cotton, opened with a card, a fiber web is formed through a webber, and the obtained fiber web has a thickness of a leather-like sheet to be obtained. Depending on the weight, it may be laminated and then entangled by a known method such as a needle punch method or a high-pressure hydroentanglement method to make a nonwoven fabric, or this staple fiber or cut fiber, A cloth in which a water flow, a needle, or the like is entangled with a cloth knitted and woven in advance may be used in the same manner as the nonwoven fabric.

If necessary, the nonwoven fabric produced by the above method is applied with a polyvinyl alcohol-based paste or the surface of the constituent fiber is melted to bond the nonwoven fabric constituent fibers and temporarily fix the nonwoven fabric. May be performed. By performing this treatment, it is possible to prevent the nonwoven fabric from being structurally broken due to tension or the like in the subsequent step of applying the elastic polymer.
Since the fibers of the obtained nonwoven fabric contract by heat treatment, the appearance can be improved thereby.
The shrinking method may be a method of putting in hot air or a method of putting in hot water, but a hot water bath is preferable because heat is uniformly transferred to the inside of the nonwoven fabric and shrinks.

  Next, the nonwoven fabric is impregnated with a solvent of a polymer elastic body and then gelled by drying by heating, or after the impregnation, it is immersed in a liquid containing a non-solvent of the polymer elastic body and wet solidified. This makes it possible to form a dense foam of a polymer elastic body. Examples of the polymer elastic body impregnated here include at least one polymer selected from diols such as polyester diol, polyether diol, and polycarbonate diol having an average molecular weight of 500 to 3000, or composite diols such as polyester polyether diol. Diol, at least one diisocyanate selected from aromatic diisocyanates such as 4,4′-diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, alicyclic diisocyanate, aliphatic diisocyanate, ethylene glycol, isophorone diamine, etc. Polyurethane obtained by reacting at least one kind of low molecular weight compound (chain extender) having two or more active hydrogen atoms at a predetermined molar ratio and its modification And the like, Other, polyester elastomer, a styrene - isoprene block copolymer elastic polymer and an acrylic resin such as a hydrogenated product also mentioned. Moreover, the composition which mixed these may be sufficient.

  Among the above polymer elastic bodies, more preferred are polyurethanes using polyester diol and ester-ester polyester elastomers, and more preferred are polyethylene propylene adipate glycol, polyurethane using polyethylene adipate glycol, and polybutylene terephthalate. A polyester elastomer composed of polycaprolactone diol.

From the viewpoints of flexibility, elastic recovery, sponge formation, durability, etc., the above polyurethane is preferably used.
A non-woven fabric is impregnated with a polymer elastic body fluid obtained by dissolving or dispersing a polymer elastic body as described above in a solvent or a dispersant and treated with a non-solvent of resin to form a sponge, or heat-dried as it is. Then, a sheet is obtained by the method of gelling and making a sponge.
The polymer elastic body fluid may contain additives such as a colorant, a coagulation regulator, an antioxidant, and a dispersant as required.

The ratio of the polymer elastic body is 10% or more, preferably 30 to 50%, based on the total weight of the sheet as a solid content. If the ratio of the polymer elastic body is less than 10%, the fibers constituting the nonwoven fabric are easily lost.
When ultrafine fiber-generating fibers are used as the fibers, the ultrafine fibers may be generated by subjecting the sheet containing the polymer elastic body to an extraction process or a separation separation process, and the polymer elastic body is contained. Although the ultrafine fibers may be generated before, it is preferable to generate the ultrafine fibers after handling or simultaneously containing the polymer elastic body.

  In the present invention, the leather-like sheet can be suede-like artificial leather by fluffing the surface. As the fluffing method, a method of buffing the surface using sandpaper or a needle cloth can be used.

  Moreover, it can also be set as what is called a leather-like leather-like sheet | seat which has a silver surface layer on the sheet | seat surface. As a method for providing this silver surface layer, a sheet of a nonwoven fabric impregnated with a polymer elastic body is coated with a resin solution for the silver surface layer, dried and then embossed, or separately coated on a release paper. A release paper method is known, in which a resin layer for a silver surface layer is bonded to a sheet in which a nonwoven fabric is impregnated with a polymer elastic body through an adhesive layer of a polyurethane resin in a semi-dried state. Can do.

The leather-like sheet of the present invention can be dyed using a disperse dye. Since the hydrolysis resistance is improved, it can be dyed under high temperature conditions and can be dyed dark.
The leather-like sheet of the present invention is used for various purposes in which leather-like sheets are used, such as interior goods such as sofa upholstery materials, clothing, vehicle interior use, industrial material use, etc., in addition to miscellaneous goods such as shoes, bags, and accessories. Can be used.

  EXAMPLES The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to these examples. In addition, each value in a present Example was calculated | required with the following method.

(1) Hydrolysis resistance:
Hydrolysis resistance is determined to be good when the carboxyl group terminal amount of the composition is 0 equivalent / ton, and is determined to be acceptable when it is 10 equivalent / ton or less, and exceeds 10 equivalent / ton. No. The terminal amount of the carboxyl group was determined by dissolving a weighed sample in o-cresol adjusted to a water content of 5%, adding an appropriate amount of dichloromethane to this solution, and titrating with 0.02 N potassium hydroxide methanol solution. .

(2) Quality of work environment:
Judgment was made based on whether the working environment was deteriorated by the isocyanate odor during the production of the resin composition. When it did not deteriorate, it was evaluated as good.
In this example, the following agents were produced and used as the cyclic carbodiimide compound.

[Production Example 1] Synthesis of cyclic carbodiimide compound CC1 (MW = 252):
Reaction in which 200 ml of o-nitrophenol (0.11 mol), 1,2-dibromoethane (0.05 mol), potassium carbonate (0.33 mol), and N, N-dimethylformamide (DMF) were installed with a stirrer and a heating device The apparatus was charged in an N ₂ atmosphere and reacted at 130 ° C. for 12 hours. After that, DMF was removed under reduced pressure, and the resulting solid was dissolved in 200 ml of dichloromethane and separated three times with 100 ml of water. The organic layer was dehydrated with 5 g of sodium sulfate, and dichloromethane was removed under reduced pressure to obtain an intermediate product A (nitro form).

  Next, intermediate product A (0.1 mol), 5% palladium carbon (Pd / C) (1 g), and 200 ml of ethanol / dichloromethane (70/30) were charged into a reactor equipped with a stirrer, and 5 hydrogen substitution was performed. The reaction was performed in a state where hydrogen was constantly supplied at 25 ° C., and the reaction was terminated when there was no decrease in hydrogen. When Pd / C was recovered and the mixed solvent was removed, an intermediate product B (amine body) was obtained.

Next, triphenylphosphine dibromide (0.11 mol) and 150 ml of 1,2-dichloroethane were charged and stirred in a reactor equipped with a stirring device, a heating device, and a dropping funnel in an N ₂ atmosphere. A solution prepared by dissolving intermediate product B (0.05 mol) and triethylamine (0.25 mol) in 50 ml of 1,2-dichloroethane was gradually added dropwise thereto at 25 ° C. After completion of dropping, the reaction was carried out at 70 ° C. for 5 hours. Thereafter, the reaction solution was filtered, and the filtrate was separated 5 times with 100 ml of water. The organic layer was dehydrated with 5 g of sodium sulfate, and 1,2-dichloroethane was removed under reduced pressure to obtain an intermediate product C (triphenylphosphine compound).

Next, in a reactor equipped with a stirrer and a dropping funnel, di-tertbutyl dicarbonate (0.11 mol), N, N-dimethyl-4-aminopyridine (0.055 mol), dichloromethane 150 ml under N ₂ atmosphere. Were charged and stirred. Thereto, 100 ml of dichloromethane in which the intermediate product C (0.05 mol) was dissolved was slowly added dropwise at 25 ° C. After dropping, the reaction was allowed to proceed for 12 hours.
Then, CC1 shown by the following structural formula was obtained by refine | purifying the solid substance obtained by removing dichloromethane. The structure of CC1 was confirmed by NMR and IR.

[Production Example 2] Synthesis of cyclic carbodiimide compound CC2 (MW = 516):
o- nitrophenol (0.11 mol) and pentaerythrityl tetra bromide (0.025 mol), potassium carbonate (0.33mol), _N, N ₂ N- dimethylformamide 200ml in reactor installed with a stirrer and a heating device After charging in an atmosphere and reacting at 130 ° C. for 12 hours, DMF was removed under reduced pressure, and the resulting solid was dissolved in 200 ml of dichloromethane and separated three times with 100 ml of water. The organic layer was dehydrated with 5 g of sodium sulfate, and dichloromethane was removed under reduced pressure to obtain an intermediate product D (nitro form).

  Next, intermediate product D (0.1 mol), 5% palladium carbon (Pd / C) (2 g), and 400 ml of ethanol / dichloromethane (70/30) were charged into a reactor equipped with a stirrer, and 5 hydrogen substitution was performed. The reaction was performed in a state where hydrogen was constantly supplied at 25 ° C., and the reaction was terminated when there was no decrease in hydrogen. Pd / C was recovered, and the mixed solvent was removed to obtain an intermediate product E (amine body).

Next, triphenylphosphine dibromide (0.11 mol) and 150 ml of 1,2-dichloroethane were charged and stirred in a reactor equipped with a stirrer, a heating device, and a dropping funnel in an N ₂ atmosphere. A solution prepared by dissolving the intermediate product E (0.025 mol) and triethylamine (0.25 mol) in 50 ml of 1,2-dichloroethane was gradually added dropwise thereto at 25 ° C. After completion of dropping, the reaction was carried out at 70 ° C. for 5 hours.
Thereafter, the reaction solution was filtered, and the filtrate was separated 5 times with 100 ml of water. The organic layer was dehydrated with 5 g of sodium sulfate, and 1,2-dichloroethane was removed under reduced pressure to obtain an intermediate product F (triphenylphosphine compound).

Next, in a reactor equipped with a stirrer and a dropping funnel, di-tert-butyl dicarbonate (0.11 mol), N, N-dimethyl-4-aminopyridine (0.055 mol), dichloromethane under N ₂ atmosphere. 150 ml is charged and stirred. Thereto, 100 ml of dichloromethane in which the intermediate product F (0.025 mol) was dissolved was slowly added dropwise at 25 ° C. After dropping, the reaction was allowed to proceed for 12 hours.
Then, CC2 shown by the following structural formula was obtained by refine | purifying the solid substance obtained by removing dichloromethane. The structure of CC2 was confirmed by NMR and IR.

[Production Example 3] (Production of poly L-lactic acid)
To 100 parts by weight of L-lactide (manufactured by Musashino Chemical Laboratory, Inc., 100% optical purity), 0.005 part by weight of octyltinate was added, and the reaction was carried out at 180 ° C. in a reactor equipped with a stirring blade in a nitrogen atmosphere. After reacting for 2 hours, phosphoric acid equivalent to 1.2 times the amount of tin octylate was added, and then the remaining lactide was removed at 13.3 kPa to obtain chips to obtain poly L-lactic acid.
The obtained L-lactic acid had a weight average molecular weight of 150,000, a glass transition point (Tg) of 63 ° C., and a melting point of 180 ° C.

[Production Example 4] (Production of poly-D-lactic acid)
To 100 parts by weight of D-lactide (manufactured by Musashino Chemical Laboratory, Inc., 100% optical purity), 0.005 part by weight of tin octylate was added, and the reactor was stirred at 180 ° C. with a stirring blade in a nitrogen atmosphere. After reacting for 2 hours, phosphoric acid equivalent to 1.2 times the amount of tin octylate was added, and then the remaining lactide was removed at 13.3 kPa to obtain chips to obtain poly-D-lactic acid.
The obtained poly-D-lactic acid had a weight average molecular weight of 150,000, a glass transition point (Tg) of 63 ° C., and a melting point of 180 ° C.

[Production Example 5] (Production of stereocomplex polylactic acid resin)
50 parts by weight of each of the poly L-lactic acid obtained in Production Example 3 and the poly D-lactic acid of Production Example 4 and a phosphate ester metal salt (2,2-methylenebis (4,6-di-tert-butylphenol) phosphate) Sodium complex, average particle size 5 μm, “ADEKA STAB” NA-11, manufactured by ADEKA Corporation, 0.1 part by weight is melt-kneaded at 230 ° C., strands are taken in a water tank, chips are formed with a chip cutter, and stereocomplex polylactic acid chips Got. The obtained stereocomplex polylactic acid resin had an Mw of 135,000, a melting point (Tm) of 217 ° C., and a stereocomplex crystallinity of 100%.

[Example 1] Production of leather-like sheet:
The poly L-lactic acid chip and the cyclic carbodiimide compound (CC1) obtained by the operation of Production Example 3 were each dried and then mixed at a weight ratio of 99: 1, followed by spinning at an extruder type spinning machine. Melt spinning was performed at 250 ° C. and a spinning speed of 1000 m / min, and this was drawn in warm water at 60 ° C. to obtain a tow composed of fibers having a single fiber fineness of 1.5 dTex. This was supplied to an indentation type crimper to give crimps, and then dried, and further a raw cotton having a cut length of about 51 mm was obtained with a rotary cutter. Using the obtained raw cotton, it was made into a fiber web through the steps of a card and a cross wrapper, and subjected to needle punching to obtain a nonwoven fabric.
The obtained nonwoven fabric was contracted in hot water at 85 ° C., subsequently impregnated in an aqueous polyvinyl alcohol solution, and further hot pressed with a calender roll to obtain an entangled nonwoven fabric having a smooth surface.
This entangled nonwoven fabric was impregnated with a dimethylformamide solution of polyurethane having a solid content of 13% mainly composed of polytetramethylene ether polyurethane, dipped in a DMF / water mixed solution and wet-solidified to obtain a fiber sheet.
The surface of the fiber sheet was ground using sandpaper to form napped hairs to obtain a leather-like sheet (suede tone). The mass ratio of polyurethane in the leather-like sheet was 30%.

On the other hand, a polyurethane resin solution consisting of 100 parts of polyether-based polyurethane, 30 parts of DMF and 30 parts of methyl ethyl ketone is applied on a release paper with a grain so as to form a silver layer, and dried to a thickness of 50 μm at 100 ° C. It dried for 5 minutes and obtained the coating layer for silver surface layer formation. On top of that, a two-component curable polyether-based polyurethane solution is applied to a thickness of 30 μm after drying, dried at 50 ° C. for 3 minutes, and bonded to the fiber sheet while still sticking. , Dried at 100 ° C. for 2 minutes, and then allowed to stand at 40 ° C. for 3 days, after which the release paper was peeled off to obtain a leather-like sheet (with silver).
The obtained leather-like sheet was suede-like or silver-attached, and both forms had excellent touch.
Further, generation of isocyanate odor was not felt during melt-kneading, spinning, and processing.
Further, when the polylactic acid filament immediately after spinning was sampled, the carboxyl end group amount was 0 equivalent / ton, and the carboxyl end group amount of the polylactic acid fiber extracted from the obtained leather-like sheet was 0 equivalent / ton. It was.

[Example 2] Production of leather-like sheet 2:
In Example 1, as a filament, the stereocomplex polylactic acid chip obtained by the operation of Production Example 5 and the cyclic carbodiimide compound (CC2) were each dried and then mixed so that the weight ratio was 99: 1. The same operation was carried out except that was used.
The obtained leather-like sheet was suede-like or silver-attached, and both forms had excellent touch.
Further, generation of isocyanate odor was not felt during melt-kneading, spinning, and processing.
Further, when the polylactic acid filament immediately after spinning was sampled, the carboxyl end group amount was 0 equivalent / ton, and the carboxyl end group amount of the polylactic acid fiber extracted from the obtained leather-like sheet was 0 equivalent / ton. It was.

[Comparative Example 1]
In Example 1, it replaced with cyclic carbodiimide (CC1), and performed the same operation except having used the linear polycarbodiimide compound [The Nisshinbo Chemical Co., Ltd. product; "Carbodilite" HMV-8CA]. The obtained leather-like sheet was suede-like or silver-attached, and both forms had excellent touch.
When the polylactic acid filaments immediately after spinning were sampled, the amount of carboxyl end groups was 1 amount / ton, and the amount of carboxyl end groups of the polylactic acid fiber extracted from the obtained leather-like sheet was 2 equivalents / ton. I sometimes felt the generation of an isocyanate odor.

[Comparative Example 2]
In Example 1, the same operation was performed except that the cyclic carbodiimide (CC1) was not used. The obtained leather-like sheet was suede-like or silver-coated, and both forms had excellent tactile sensation, and generation of isocyanate odor was not felt during melt-kneading, spinning and processing.
Furthermore, when the polylactic acid filament immediately after spinning was sampled, the carboxyl end group amount was 15 equivalent / ton, and the carboxyl end group amount of the polylactic acid fiber extracted from the obtained leather-like sheet was 25 equivalent / ton. The hydrolysis resistance was inferior to that obtained in the examples.

  According to the present invention, there is provided a leather-like sheet comprising a nonwoven fabric composed of a fiber comprising an aliphatic polyester resin composition having improved hydrolysis resistance and free of generation of a free isocyanate compound, and a polymer elastic body. can do.

Claims (15)

  Nonwoven fabric composed of fibers made of an aliphatic polyester resin composition containing a compound (component C) containing a cyclic structure in which one carbodiimide group and the first nitrogen and the second nitrogen are bonded by a bonding group A leather-like sheet consisting of a polymer elastic body.   The leather-like sheet according to claim 1, wherein the number of atoms forming the cyclic structure of the C component is 8-50. The leather-like sheet according to claim 1 or 2, wherein the cyclic structure of component C is represented by the following formula (1).

(In the formula, Q is a divalent to tetravalent linking group that is an aliphatic group, an alicyclic group, an aromatic group, or a combination thereof, and may contain a hetero atom.) The leather-like sheet according to claim 3, wherein Q is a divalent to tetravalent linking group represented by the following formula (1-1), (1-2) or (1-3).

(In the formula, Ar ¹ and Ar ² are each independently an aromatic group having 2 to 4 carbon atoms and 5 to 15 carbon atoms. R ¹ and R ² are each independently 1 to 2 carbon atoms having 1 to 4 carbon atoms. 20 aliphatic groups, 2 to 4 valent alicyclic groups having 3 to 20 carbon atoms, or combinations thereof, or these aliphatic groups, alicyclic groups and 2 to 4 valent aromatic carbon atoms having 5 to 15 carbon atoms X ¹ and X ² are each independently a divalent to tetravalent aliphatic group having 1 to 20 carbon atoms, a divalent to tetravalent carbon atom having 3 to 20 alicyclic groups, 2 to 4 A valent aromatic group having 5 to 15 carbon atoms, or a combination thereof, s is an integer of 0 to 10. k is an integer of 0 to 10. When s or k is 2 or more, X ¹ or X ² as a repeating unit may be different from other X ¹ or X ^2. X ³ is a divalent to tetravalent carbon number. An aliphatic group having 1 to 20 carbon atoms, an alicyclic group having 2 to 4 carbon atoms having 3 to 20 carbon atoms, an aromatic group having 2 to 4 carbon atoms having 5 to 15 carbon atoms, or a combination thereof, provided that Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ² and X ³ may contain a hetero atom, and when Q is a divalent linking group, Ar ¹ , Ar ² , R 3 ¹ , R ² , X ¹ , X ² and X ³ are all divalent groups, and when Q is a trivalent linking group, Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ^{One of 2} and X ³ is a trivalent group, and when Q is a tetravalent linking group, one of Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ² and X ³ One of them is a tetravalent group or two are trivalent groups.) The leather-like sheet according to claim 3, wherein the compound containing a cyclic structure of component C is represented by the following formula (2).

(In the formula, Qa is a divalent linking group that is an aliphatic group, an alicyclic group, an aromatic group, or a combination thereof, and may contain a hetero atom.) The leather-like sheet according to claim 5, wherein Qa is a divalent linking group represented by the following formula (2-1), (2-2) or (2-3).

(In the formula, Ar _a ¹ , Ar _a ² , R _a ¹ , R _a ² , X _a ¹ , X _a ² , X _a ³ , s and k are represented by the formulas (1-1) to (1-3), respectively. The same as Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ² , X ³ , s and k in the above) The leather-like sheet according to claim 3, wherein the compound containing a cyclic structure of component C is represented by the following formula (3).

(Wherein Q _b is a trivalent linking group which is an aliphatic group, an alicyclic group, an aromatic group, or a combination thereof, and may contain a hetero atom. Y represents a cyclic structure. It is a carrier to be supported.) Q _b is leather-like sheet according to claim 7 is a trivalent bonding group represented by the following formula (3-1), (3-2) or (3-3).

(In the formula, Ar _b ¹ , Ar _b ² , R _b ¹ , R _b ² , X _b ¹ , X _b ² , X _b ³ , s and k are represented by the formulas (1-1) to (1-3), respectively. Are the same as Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ² , X ³ , s, and k, with one of these being a trivalent group.)   The leather-like sheet according to claim 7 or 8, wherein Y is a single bond, a double bond, an atom, an atomic group or a polymer. The leather-like sheet according to claim 3, wherein the compound containing a cyclic structure of component C is represented by the following formula (4).

(Wherein Q _c is a tetravalent linking group that is an aliphatic group, an aromatic group, an alicyclic group, or a combination thereof, and may have a hetero atom. Z ¹ and Z ² are A carrier carrying a ring structure.) The leather-like sheet according to claim 10, wherein Q _c is a tetravalent linking group represented by the following formula (4-1), (4-2), or (4-3).

(In the formula, Ar _c ¹ , Ar _c ² , R _c ¹ , R _c ² , X _c ¹ , X _c ² , X _c ³ , s and k are respectively represented by formulas (1-1) to (1-3) Are the same as Ar ¹ , Ar ² , R ¹ , R ² , X ¹ , X ² , X ³ , s and k, provided that one of them is a tetravalent group or two are 3 Valent group.) The leather-like sheet according to claim 11, wherein Z ¹ and Z ² are each independently a single bond, a double bond, an atom, an atomic group or a polymer.   The leather-like sheet according to any one of claims 1 to 12, wherein the content of component C is 0.001 to 10 parts by weight per 100 parts by weight of the aliphatic polyester resin.   The leather-like sheet according to any one of claims 1 to 13, wherein the aliphatic polyester resin is polylactic acid.   The leather-like sheet according to claim 14, wherein the polylactic acid forms a stereocomplex crystal.