JP2003306526A - Solventless moisture-curable hot-melt urethane resin composition, foam and sheet structure using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solventless, moisture-curable hot-melt urethane resin composition which obtains a high performance porous layer having both excellent adhesion and durability (particularly hydrolysis resistance and heat resistance), a foam using the same, a sheet structure having a foamed layer on a substrate, and a sheet structure having, on a substrate, a foamed layer integrated with a leather-like film layer. <P>SOLUTION: The solventless moisture-curable hot-melt urethane resin composition comprises (A) a urethane prepolymer obtained by reacting a polyol component with a polyisocyanate component, (B) an amine catalyst, and (C) water, and a polyfunctional polyol is used as an essential component in the polyol component of the component (A); the content of the polyfunctional polyol in the polyol component of the component (A) is 1-50 wt.%; the softening point of the component (A) is 30-160°C; and the equivalent ratio of the NCO group to the OH group in the polyisocyanate component and the polyol component constituting the component (A) is in a range of 1.1-5.0. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel solvent-free, moisture-curable hot-melt urethane resin composition having excellent durability (particularly hydrolysis resistance and heat resistance), which is useful, and a foam thereof. Relates to a sheet structure using. More specifically, in addition to synthetic leather and artificial leather, adhesives, adhesives, sealing agents, paints, coating agents, films,
The present invention relates to a solventless moisture-curable hot-melt urethane resin composition used for a wide range of applications such as a sheet, a heat insulating material, a sound absorbing material, and a cushioning material, a foam, and a sheet structure using the same.

[0002]

2. Description of the Related Art Polyurethane resins have hitherto been widely used for artificial leather and synthetic leather. In the broad sense, artificial leather or synthetic leather refers to a sheet-like material obtained by combining a polyurethane resin composition with a non-woven fabric, a woven fabric, a knitted fabric, or the like, but is generally classified as follows. Has been done.

That is, "artificial leather" refers to a sheet-like material in which a polyurethane resin composition is filled or laminated in a non-woven fabric, and its production method is generally dimethylformamide (hereinafter referred to as "polyurethane resin composition"). , DMF) is impregnated or coated with a non-woven fabric, and the polyurethane resin is coagulated into a porous state in a water coagulation bath or a coagulation bath consisting of a mixed solution of DMF and water. A method of passing through a drying step, a so-called wet processing method is adopted.

If necessary, the surface of the sheet-like material thus obtained may be made smooth by laminating or coating the surface of the sheet-like material, or the surface of the sheet-like material may be buffed. By doing so, the method of doing with a nubuck or suede tone is also used.

On the other hand, the "synthetic leather" is generally classified into dry synthetic leather and wet synthetic leather.
A sheet-shaped product in which a polyurethane resin composition is laminated is referred to. As a method of manufacturing dry synthetic leather, generally,
First, a polyurethane resin solution for the skin is mixed with a pigment, a solvent, an additive and the like, coated on a release paper and dried to obtain a polyurethane resin for the skin. Next, a two-component polyurethane resin and an isocyanate are applied as an adhesive to the above-prepared polyurethane resin for the skin, and a raised fabric is pressure-bonded before drying and then dried and aged. As a method for producing wet synthetic leather, generally, a DMF solution of a polyurethane resin composition is impregnated or coated on a woven fabric or a knitted fabric, which is formed by a water coagulation bath or a DMF-water mixed solution. In the coagulation bath, after the polyurethane resin is coagulated into a porous form, it is obtained by a method of undergoing a washing step and a drying step.
The so-called wet processing method is mainly adopted.

Further, if necessary, the surface of the sheet-like material thus obtained is subjected to laminating or coating to make it smooth so that the sheet-like material can be made smooth. By buffing the surface of, the method of making it nubuck or suede is also used.

Since a solvent type urethane resin is used in these processing methods, it is indispensable to dry the solvent and extract the solvent during the processing process. There are various problems such as the energy cost required to evaporate the solvent, and the demand for the shift from solvent-based resins to solvent-free resins and processing methods has recently increased.

[0008] In order to meet the above requirements, a water-based method has been studied as a solvent-free method, but its practical use is limited due to poor water resistance and durability. Also,
The use of a solvent-free liquid crosslinked resin is also a solvent-free method, but since the expression of the cohesive force depends on the crosslinking, there is a problem that it is difficult to adjust the expression of the cohesive force during processing such as coating and laminating. For example, if heating is used to accelerate cross-linking and increase the development of cohesive force in order to increase productivity during processing, the time that can be processed such as coating and laminating becomes too narrow, which tends to hinder production. If the temperature at the time of processing is lowered in order to extend the range of processing time, there is a fear that the cross-linking becomes too slow, the expression of cohesive force is delayed, and the productivity is lowered, which makes it difficult to apply to synthetic leather processing.

Further, "reactive hot melt", which is used as an adhesive or a coating material by heating and melting a solid reactive resin at room temperature, is well known, but especially for artificial leather or synthetic leather used for automobiles. When used in the foam layer, excellent durability (particularly hydrolysis resistance and heat resistance) was required.

Further, "solventless moisture-curable (reactive) hot melt", which is used for adhesives and coating materials by heating and melting a solid reactive resin at room temperature, is well known. Heretofore, as an example of foaming a reactive hot melt, a method of introducing an inert gas into a reactive hot melt in a molten state under pressure has been disclosed (JP-A-3-6281). It has the drawback that it will not foam unless it is pressurized and released to ambient pressure.

Further, in the reactive hot melt composition, adhesion and durability (especially hydrolysis resistance and heat resistance)
There has been a demand for the development of a composition having excellent properties such as. Therefore, first, the inventors of the present invention filed Japanese Patent Application 2001-344.
In No. 706, it was found that it is possible to improve durability (particularly, hydrolyzability) and to obtain a uniform foam cell shape without applying pressure, but it was investigated to impart further excellent heat resistance. did.

[0012]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a solventless moisture-curable hot-melt polyurethane resin composition, a foam, a sheet structure having a foam layer, and a foam layer and leather for the foam layer. When used in a sheet structure that integrates such film layers, a high-performance porous layer with excellent adhesion and durability (especially hydrolysis resistance and heat resistance) based on moisture curing reaction is obtained. Solvent-free moisture-curable hot-melt urethane resin composition, foam obtained using the same, sheet structure having foam layer on substrate, foam layer on substrate and leather-like material on the foam layer To provide a sheet structure in which the film layers of (1) are integrated.

[0013]

Means for Solving the Problems The inventors of the present invention have made extensive studies to solve the above problems, and as a result, construct a hot melt urethane prepolymer (A) [hereinafter referred to as prepolymer (A)]. An isocyanate group-terminated urethane prepolymer in which the softening point of the prepolymer (A) is in the range of 30 to 160 ° C., and / or an alkoxysilyl group, containing a polyfunctional polyol as an essential component in the range of 1 to 50% by weight in the polyol component. The amine-based catalyst (B), which is a terminal urethane prepolymer and has a polyisocyanate component and a polyol component in which the equivalent ratio of the isocyanate group to the hydroxyl group is in the range of 1.1 to 5.0, is heated and melted. , And water (C), and in some cases, an inert gas is mixed to foam water, and then a foam is formed to cool and solidify, and further cross-link. When it is applied, or when it is applied on a substrate to form a foamed layer and then cooled and solidified and further cured by cross-linking, the foamed layer is further formed between the leather-like film layer and the substrate. A high-performance foam having excellent adhesion and durability (particularly hydrolysis resistance and heat resistance) based on a moisture curing reaction when cooled and solidified and further cured by crosslinking, and a sheet structure having such a foam layer. It was found that a body- and leather-like sheet structure can be obtained, and the present invention has been completed.

That is, the present invention is a solventless moisture curable hot melt urethane resin composition comprising a prepolymer (A) obtained by reacting a polyol component and a polyisocyanate component, an amine catalyst (B), and water (C). The present invention provides a solventless moisture-curable hot melt urethane resin composition, which comprises a polyfunctional polyol as an essential component in the polyol component of the prepolymer (A).

The present invention also provides a foam characterized in that the above solventless moisture-curable hot-melt urethane resin composition is water-foamed and then cured.

The present invention also provides a foam characterized in that the above solventless moisture-curable hot-melt urethane resin composition is mixed with an inert gas in advance, foamed with water, and then cured. It is provided.

Further, the present invention is characterized by having a base material and a foamed layer obtained by water-foaming the solventless moisture-curable hot-melt urethane resin composition on the base material and then curing it. A sheet structure is provided.

In the present invention, the base material and the solvent-free, moisture-curable hot-melt urethane resin composition on the base material are mixed with an inert gas in advance, water-foamed, and then cured. Provided is a sheet structure having a foam layer.

The present invention also provides a base material, a solvent-free, moisture-curable hot-melt urethane resin composition on the base material, which is water-foamed and then cured, and a cured foam layer and a leather-like layer on the foam layer. The present invention provides a sheet structure characterized by integrating the above film layers.

Further, according to the present invention, a base material and the solventless moisture-curable hot-melt urethane resin composition on the base material are mixed with an inert gas in advance, water-foamed, and then cured. A sheet structure comprising a foam layer and a leather-like film layer integrated with the foam layer.

Further, the present invention is characterized by having a leather-like film and a foam layer obtained by water-foaming the solventless moisture-curable hot-melt urethane resin composition on the film and then curing the same. A sheet structure is provided.

Further, in the present invention, a leather-like film and the above solventless moisture-curable hot-melt urethane resin composition are premixed with an inert gas, water-foamed and then cured. A sheet structure having a foamed layer is provided.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The necessary items for carrying out the present invention will be described below.

First, a hot melt urethane prepolymer (A) having an isocyanate group terminal and / or an alkoxysilyl group terminal obtained by reacting a polyisocyanate component with a polyol component containing a polyfunctional polyol as an essential component, an amine catalyst (B), A solventless moisture-curable hot-melt urethane resin composition comprising water and water (C) will be described.

The prepolymer (A) constituting the solventless moisture-curable hot-melt urethane resin composition of the present invention which is excellent in durability (in particular, hydrolysis resistance and heat resistance) is 1 to
Isocyanate group-terminated urethane prepolymer (a-1) in which an isocyanate group obtained by reacting a polyol component containing 50% by weight of a polyfunctional polyol as an essential component with an isocyanate component remains, and / or a polyol component and a polyisocyanate component And an alkoxysilane-terminated urethane prepolymer having a hydrolyzable silyl group obtained by reacting a compound having a hydrolyzable silyl group with one or more active hydrogen atoms per molecule that reacts with -2).

The isocyanate group-terminated urethane prepolymer (a-1) used in the present invention comprises a polyol component and a polyisocyanate component in an equivalent ratio of NCO groups of isocyanate and OH groups of polyol (NCO group / OH group equivalent ratio).
Is 1 or more, that is, it is obtained by reacting in excess of NCO groups. The NCO group / OH group equivalent ratio is usually preferably in the range of 1.1 to 5.0, and more preferably 1.5.
The range is from 3.0 to 3.0. When the NCO group / OH group equivalent ratio is in such a range, excellent processability, foam retention, and appropriate crosslink density can be obtained.

The alkoxysilyl group-terminated urethane prepolymer (a-2) has a polyol component, a polyisocyanate component, and one or more active hydrogen atoms that react with the isocyanate group per molecule, and is hydrolyzable. It is obtained by reacting a compound having a silyl group. Usually, the above-mentioned polyurethane prepolymer having an isocyanate group has one active hydrogen atom capable of reacting with the isocyanate group.
A method is used in which a hydrolyzable silyl group is introduced into the terminal of a molecule by reacting an individual with a compound having a hydrolyzable silyl group. In addition, by reacting a polyurethane prepolymer having an isocyanate group with at least two or more active hydrogen atoms capable of reacting with the isocyanate group and a compound having a hydrolyzable silyl group, the isocyanate group and the hydrolyzable group are reacted in the molecule. A urethane prepolymer having an alkoxysilyl group is obtained.

The crosslinking reaction of the solventless moisture-curable hot-melt urethane resin composition of the present invention occurs when the isocyanate group or hydrolyzable silyl group in each prepolymer reacts with moisture.

The solventless, moisture-curable hot-melt urethane resin composition of the present invention has a crosslinking reactivity (that is, moisture-curability) and a hot-melt property (that is, it is solid at room temperature but melts when heated). It is a resin that also has the property of being ready for coating and having a state of producing a re-cohesion force by cooling.

As a method for processing the solventless moisture-curable hot melt urethane resin composition of the present invention, for example, the prepolymer (A) is heated to a liquid or molten state, and the amine catalyst (B) and water (C) are used. ) Is mixed and stirred to foam with water, and then a method of fixing the foamed state by utilizing hot melt property and moisture curing property is suitable. Further, when controlling the cell shape of the foam layer from the closed cell state to the continuous cell state, it is possible to mix and stir the inert gas.

The solvent-free, moisture-curable hot-melt urethane resin composition of the present invention contains, for example, active hydrogen as needed when the prepolymer (A), amine catalyst (B) and water (C) are mixed. Chain extenders, foam stabilizers, catalysts, silane coupling agents, tackifiers, waxes, plasticizers, stabilizers, fillers, pigments, additives such as optical brighteners, and thermoplastic resins alone or Multiple may be added.

The polyfunctional polyol in the polyol component of the prepolymer (A) used in the present invention is, for example,
Glycerin, trimethylolpropane, butanetriol, hexanetriol, trimethylolbutane, trimethylolpentane and other triols, pentaerythritol and other tetraols, or ethylene oxide, propylene oxide, butylene oxide and styrene starting from the polyfunctional polyols. Examples thereof include oxides alone or two or more ring-opening polymers. These may be used alone or in combination of two or more.

The polyfunctional polyol content of the polyol component of the prepolymer (A) used in the present invention is preferably 1 to 50% by weight, more preferably 5 to 30% by weight. Within such a range, a foam having excellent hydrolysis resistance and heat resistance, and a sheet structure using the foam can be obtained.

Examples of the polyol component which can be used in the present invention other than the polyfunctional polyol of the polyol component of the prepolymer (A) include, for example, polyester-based polyols, polyether-based polyols, polycarbonate-based polyols, or a mixture or copolymerization thereof. Things etc. are mentioned. Furthermore, acrylic polyols, polyolefin polyols, castor oil polyols and the like can be mentioned.

Examples of the polyester polyol usable in the present invention include ethylene glycol and 1,2-
Propylene glycol, 1,3-propylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 2,2-dimethyl-1,3-propanediol, 1,6-hexanediol, 3-methyl-1, 5-
Pentanediol, 1,8-octanediol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, cyclohexane-1,4-diol, cyclohexane-1,4-dimethanol, EO or PO adduct of bisphenol A, etc. One or more diols of succinic acid, maleic acid, adipic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, hexahydroisophthalic acid, etc. Examples thereof include a condensate with one or more dicarboxylic acids. Other examples include ring-opening polymers such as γ-butyrolactone and ε-caprolactone which use the above-mentioned glycol component as an initiator. In the present invention, E
O means ethylene oxide and PO means propylene oxide.

Examples of the polyether polyol usable in the present invention include ethylene glycol and
1,2-propylene glycol, 1,3-propylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 2,2-dimethyl-1,3-propanediol, 1,6-hexanediol, 3- Methyl-
1,5-pentanediol, 1,8-octanediol, diethylene glycol, triethylene glycol,
Dipropylene glycol, tripropylene glycol,
Cyclohexane-1,4-diol, cyclohexane-
Glycol components such as 1,4-dimethanol, polyhydric alcohols such as glycerin, trimethylolethane, trimethylolpropane and pentaerythritol, or ethylene oxide, propylene oxide, butylene oxide and styrene oxide starting from the polyester polyol. Or a ring-opening polymer of two or more thereof. Further, ring-opening addition polymers such as γ-butyrolactone and ε-caprolactone to these polyether diols can be mentioned.

Further, known low molecular weight polyols can also be used, for example, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol,
1,3-butylene glycol, 1,4-butylene glycol, 2,2-dimethyl-1,3-propanediol,
1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,8-octanediol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, cyclohexane-1,4-diol, cyclohexane-1 , 4-dimethanol, EO or PO adduct of bisphenol A, and one or more diols.

The polyisocyanate component used in the present invention is not particularly limited, but for example, phenylene diisocyanate, tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate, 2,4-diphenylmethane diisocyanate, Examples thereof include aromatic diisocyanates such as naphthalene diisocyanate, and hexamethylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, xylylene diisocyanate, tetramethyl xylylene diisocyanate, and other aliphatic or alicyclic diisocyanates. Of these, 4,4′-diphenylmethane diisocyanate (MDI), which has a low vapor pressure at the time of heating, is preferably used in consideration of being used as a hot-melt resin that is used by melting.

The softening point of the prepolymer (A) is preferably in the range of 30 to 160 ° C, more preferably 40 to 100 ° C. When the softening point is in this range, a stable and uniform foam without unevenness can be obtained, and the cooling and solidifying time can be optimized, which is preferable.

Further, in the present invention, the prepolymer (A)
May use two or more kinds of polyol components other than the polyfunctional polyol in combination, and the types of the polyol component and the polyisocyanate component used together at that time are not particularly limited.

The method of adjusting the softening point of the prepolymer (A) used in the present invention is not particularly limited, and for example,
Adjustment method by molecular weight (molar ratio of polyol component and polyisocyanate component, use of high molecular weight polyol, use of high molecular polymer, etc.), adjustment method by crystal of ethylene chain of polyester polyol, aromatic of polyol component and polyisocyanate component There are a method of adjusting the structure of the ring, a method of adjusting the amount of urethane bonds, and the like.

The alkoxysilane group-terminated prepolymer (a-2) used in the present invention has at least one active hydrogen atom per molecule that reacts with an isocyanate group, and also has a hydrolyzable silyl group. The compound is not particularly limited as long as it has at least one functional group having an active hydrogen atom that reacts with an isocyanate group per molecule and has a hydrolyzable silyl group. Examples of the functional group having an active hydrogen atom include an amino group, a hydroxyl group, and an SH group. Among them,
An amino group is preferable from the viewpoint of excellent reactivity with an isocyanate group. On the other hand, the hydrolyzable silyl group includes, for example, a silyl group which is easily hydrolyzed, such as a halosilyl group, an alkoxysilyl group, an acyloxysilyl group, a phenoxysilyl group, an iminooxysilyl group or an alkenyloxysilyl group. However, more specific examples include those represented by the following general formula [1].

[0043]

[Chemical 1]

(In the general formula [1], R ₁ is a hydrogen atom or a monovalent organic group selected from an alkyl group, an aryl group or an aralkyl group, and R ₂ is a halogen atom, an alkoxyl group or an acyloxy group. Represents a phenoxy group, an iminooxy group or an alkenyloxy group, and n
Represents an integer of 0, 1 or 2. )

Among the above-mentioned hydrolyzable silyl groups, trimethoxysilyl group, triethoxysilyl group, (methyl) dimethoxysilyl group, (methyl) diethoxysilyl group and the like are preferable from the viewpoint of easy crosslinking.

Examples of the compound containing a group reactive with an isocyanate group and a hydrolyzable silyl group include γ- (2-aminoethyl) aminopropyltrimethoxysilane and γ- (2-hydroxylethyl) aminopropyl. Trimethoxysilane, γ- (2-aminoethyl)
Aminopropyltriethoxysilane, γ- (2-hydroxylethyl) aminopropyltriethoxysilane, γ
-(2-aminoethyl) aminopropylmethyldimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldiethoxysilane, γ- (2-hydroxylethyl) aminopropylmethyldimethoxysilane, γ- (2
-Hydroxylethyl) aminopropylmethyldiethoxysilane or γ- (N, N-di-2-hydroxylethyl) aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-amino Examples include propylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, γ- (N-phenyl) aminopropyltrimethoxysilane, and the like.

The prepolymer (A) used in the present invention may be prepared by various known and commonly used methods without any particular limitation.

Generally, in the case of the isocyanate group-terminated urethane prepolymer (a-1), the water-removed polyol component is added dropwise to the starting isocyanate component and heated to react until the hydroxyl component of the polyol component disappears. can get. In the case of the alkoxysilyl group-terminated urethane prepolymer (a-2), NCO is added to the isocyanate group-terminated prepolymer (a-1) obtained as described above.
It is obtained by dropping an alkoxysilane compound having a group that reacts with a group and heating it as necessary to cause a reaction. This reaction is carried out without a solvent, but in some cases, it is also carried out in an organic solvent and then desolvated. When the reaction is carried out in an organic solvent, various conventionally known organic solvents such as ethyl acetate, n-butyl acetate, methyl ethyl ketone, and toluene can be used, and the organic solvent is not particularly limited as long as it does not inhibit the reaction. In this case, after completion of the reaction, it is necessary to remove the solvent by a solvent removal method represented by reduced pressure heating.

In the present invention, the above prepolymer (A)
However, if necessary, an active hydrogen-containing compound can be used as a chain extender at the time of use within a range that does not impair the original moisture curability.

Examples of the above active hydrogen-containing compound include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butylene glycol, 1,4-butylene glycol and 2,2-dimethyl. -1,3-propanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol,
1,8-octanediol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, cyclohexane-1,4-dimethanol, one or more diols such as EO or PO adduct of bisphenol A, and the like. Polyhydric alcohols such as glycol, glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol, or ethylene oxide, propylene oxide, butylene oxide, and styrene oxide, which are initiated with the polyester polyol, as a single or two or more ring-opening polymerizations. And ring-opening addition polymers such as γ-butyrolactone and ε-caprolactone of the above polyether diols can be used. Among these, glycol is preferable in consideration of processing suitability because the reaction with the isocyanate group during processing is slow and the crosslinking rate is easily controlled.

The amount of these active hydrogen-containing compounds used is preferably in the range of 0.1 to 10 parts by weight, more preferably 0.1% by weight, based on 100 parts by weight of the prepolymer (A).
It is in the range of 5 to 5 parts by weight. When the amount of the active hydrogen-containing compound used is in such a range, a good thickening effect can be obtained, foam retention is good, and gelation does not occur during mixing and stirring, which is preferable.

Examples of the amine-based catalyst (B) used in the present invention include ethylenediamine, 1,3-propylenediamine, 1,2-propylenediamine, hexamethylenediamine, norbornenediamine, hydrazine, pyrerazine, N, N '. -Diaminopiperazine, 2-methylpiperazine, 4,4'-diaminodicyclohexylmethane, isophoronediamine, diaminobenzene, diphenylmethanediamine, methylenebisdichloroaniline, triethylenediamine, tetramethylhexamethylenediamine, triethylamine (TEA), tripropylamine, Trimethylaminoethylpiperazine, N-methylmorpholine, N-ethylmorpholine, di (2,6-dimethylmorpholinoethyl) ether, pentamethyldiethylenetriamine, Oxamethyl tetraethylene tetraamine (HMTETA), dimethylaminoethyl ethanol ether (DMAEE), trimethylaminoethyl ethanolamine (TMAEEA), bisdimethylaminoethyl ether (BDMEE), N, N-dimethylcyclohexylamine (DMCHA), N- Methyldicyclohexylamine (MDCHA) N, N, N ', N'-
Tetramethylethylenediamine (TMEDA) N, N,
N ', N'-tetramethylpropylenediamine (TMPD
A), N, N, N ′, N′-tetramethylhexamethylenediamine (TMHMDA), N, N, N ′, N ″, N ″
-Pentamethylethylene propylene triamine (PME
PTA), N, N, N ′, N ″, N ″ -pentamethyldipropylenetetraamine (PMDPTA), N, N,
N ′, N ″, N ′ ″, N ′ ″-hexamethyldipropyleneethylenetetraamine (HMAPEDA), N, N,
N'-trimethyl-N-aminoethylpyrazine (TM
NAEP), N-hydroxyethylmorpholine (HE
MO), N, N, N ', N'-tetramethyldipropylene ethylene glycol diamine (TMEGDA), N,
Among polyamines such as N, N ′, N ″, N ″ -pentamethyldiethylenetriamine (PMDETA), one kind or a mixture of two or more kinds can be used.

The amount of the amine-based catalyst (B) used is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the prepolymer (A).
Parts by weight. When the amount of the amine-based catalyst (B) used is within such a range, a good thickening effect can be obtained, foaming property is good, and no gelation occurs during mixing and stirring, which is preferable.

Next, the water (C) used in the hot melt urethane resin composition of the present invention is mixed with the amine catalyst (B) and mixed with the prepolymer (A) and stirred to foam water. It is an essential ingredient.

The amount of water (C) added is the same as that of the prepolymer (A).
It is preferably 0.01 to 5.0 parts by weight, more preferably 0.05 to 1.0 parts by weight, relative to 100 parts by weight.
When the amount of water (C) added is in such a range, the degree of foaming becomes appropriate and the surface condition of the foam becomes good, which is preferable.

In the present invention, if necessary, a foam stabilizer may be used at the time of use within a range that does not impair the original moisture curability. Specific examples include those containing 10 wt% or more of a conventionally known polysiloxane-polyoxyalkylene copolymer used as an organic silicon-based surfactant. Examples of the foam stabilizer include trade names SF2969 and PRX60 manufactured by Toray Dow Corning Silicone Co., Ltd.
7, SF2964, SRX274C, SF2961, S
F2962, SF2965, SF2908, BY10-
123, SF2904, SRX294A, BY10-1
24, SF2935F, SF2945F, SF2944
F, SF2936F, SH193, SH192H, SH
192, SF2909, SH194, SH190, SR
X290A, SRX298, and product names L-580, SZ1127, SZ1111, manufactured by Nippon Unicar Co., Ltd.
SZ1136, SZ1919, SZ1105, SZ11
42, SZ1162, L3601, L5309, L53
66, SZ1306, SZ1311, SZ1313, S
Z1342, L5340, L5420, SZ1605,
SZ1627, SZ1642, SZ1649, SZ16
71, SZ1675, SZ1923 and the like.

The amount of these foam stabilizers used is preferably 0.1 to 20 relative to 100 parts by weight of the prepolymer (A).
Parts by weight, more preferably 0.5 to 10 parts by weight. When the amount of the foam stabilizer used is in such a range, the foam stabilizer is excellent, and the physical mechanical strength of the foam after aging is also excellent, which is preferable.

Further, if necessary, a plasticizer such as bis (2-ethylhexyl) phthalate (DOP), diisononyl adipate (DINA), bis (2-ethylhexyl adipate) (DOA), or the like, may be added to the foam stabilizer. A polyether-based surfactant such as a / PO copolymer may be added.

The solvent-free, moisture-curable hot-melt urethane resin composition having excellent durability of the present invention has the above-mentioned cross-linking reactivity, that is, moisture-curability and hot-melt property (that is, it is solid at room temperature but heat-resistant). A resin that also has the property of being melted to be in a coatable state when added and having a cohesive force again when cooled).

The foam layer referred to in the present invention means an important layer of the multi-layer structure constituting the artificial leather or the synthetic leather to which the texture as leather is added. As a method of obtaining a foam layer,
Wet method using DMF solvent, method using foaming agent,
Known methods include the use of carbon dioxide gas generated by the reaction of isocyanate with water, and the method of mechanical foaming by forced gas mixing.

The foam of the present invention is obtained by water-foaming a solventless moisture-curable hot melt urethane resin composition comprising at least a prepolymer (A), an amine catalyst (B), and water (C). It is characterized by being hardened.

The foam of the present invention is prepared by heating the solventless moisture-curable hot-melt urethane resin composition into a liquid state or a molten state, and if necessary, mixing an inert gas in advance to foam with water. After that, a method of fixing the foamed state by curing using hot melt property and moisture curability is preferable. When an inert gas is mixed, a difference in the coefficient of thermal expansion between water and the inert gas is generated, so that the size of the foam cell can be controlled by the mixing ratio, which is effective.

Examples of the inert gas which can be used for foaming in the present invention include nitrogen, rare gas, carbon dioxide, halogenated hydrocarbon and the like.

The solventless moisture-curable hot-melt urethane resin composition of the present invention comprises the above-mentioned prepolymer (A) as a main component, and if necessary, a silane coupling agent, a tackifier, a wax, a plasticizer, Cross-linking catalyst, stabilizer, filler,
A pigment, an additive such as a fluorescent whitening agent, and a thermoplastic resin may be added singly or in plurals.

The number average molecular weight of the prepolymer (A) thus prepared is not particularly limited, but is preferably 500 to 500 from the viewpoint of fluidity and processability.
Within the range of 500000, more preferably 1000-10
It is in the range of 0000.

When preparing the reactive hot melt urethane prepolymer (A), a urethanization catalyst or a stabilizer may be used if necessary. These catalysts, stabilizers and the like can be added at any stage of the reaction, and are not particularly limited.

Examples of the urethanization catalyst include various metal salts represented by, for example, potassium acetate, zinc stearate, tin octylate; and various organometallic compounds represented by dibutyltin dilaurate. And so on. These may be used alone or in combination of two or more.

On the other hand, examples of the above-mentioned stabilizer include stabilizers against ultraviolet rays such as substituted benzotriazoles and the like, and further stabilizers against thermal oxidation such as substituted phenol derivatives. Each of the stabilizers can be appropriately selected and added according to the purpose, and may be used alone or in combination of two or more kinds.

Also in the case of the alkoxysilyl group-terminated urethane prepolymer (a-2), various acidic compounds such as malic acid and citric acid, lithium hydroxide, sodium hydroxide are used as a crosslinking catalyst, if necessary. , Various basic compounds such as potassium hydroxide, triethylenediamine, tetraisopropyl titanate, di-n-butyltin dilaurate, di-n-butyltin oxide, dioctyltin oxide or di-n-butyltin maleate, Various metal-containing compounds and the like which are generally used as alkoxysilyl group crosslinking catalysts can be added and used.

Examples of the silane coupling agent used in the present invention include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrine. Examples thereof include methoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, vinyltrimethoxysilane and γ-chloropropyltrimethoxysilane.

As the filler used in the present invention, for example, calcium carbonate, barium sulfate, kaolin, talc, carbon black, alumina, magnesium oxide,
Examples include inorganic and organic balloons. Furthermore, surface-treated calcium carbonate, fine powder silica, bentonite, sepiolite, etc., which are known as thixotropic agents, can be used. In particular, it is preferable to add a thixotropic agent for the purpose of stabilizing the foam after foaming.

The sheet structure of the present invention has a base material and a foamed layer obtained by water-foaming the solventless moisture-curable hot-melt urethane resin composition on the base material and then curing the foamed layer. And

The sheet structure of the present invention comprises a base material, the solventless moisture-curable hot-melt urethane resin composition on the base material, an inert gas previously mixed, and water-foamed,
It is characterized by having a cured foam layer.

The sheet structure of the present invention comprises a base material, a solventless moisture-curable hot-melt urethane resin composition on the base material, which is water-foamed and then cured to form a foamed layer and the foamed layer. It is characterized by integrating a leather-like film layer.

The sheet structure of the present invention comprises a base material, the solventless moisture-curable hot-melt urethane resin composition on the base material, which is previously mixed with an inert gas and water-foamed.
It is characterized in that a cured foam layer and a leather-like film layer are integrated with the foam layer.

The sheet structure of the present invention comprises a leather-like film and a foam layer obtained by water-foaming the solventless moisture-curable hot-melt urethane resin composition on the film and then curing the same. Characterize.

The sheet structure of the present invention comprises a leather-like film and the solvent-free moisture-curable hot-melt urethane resin composition, which is previously mixed with an inert gas and water-foamed. It is characterized by having a cured foam layer.

The base material constituting the sheet structure of the present invention includes, for example, non-woven fabrics, woven fabrics, knitted fabrics, and other base fabrics generally used for artificial leathers and synthetic leathers, natural leathers, and various plastic sheets. Etc. are not limited at all. In addition, solvent-based, liquid solvent-free and water-based polyurethane resins, acrylic resins, rubber-based (SBR, NBR, etc.)
There is no limitation as long as it is a non-woven fabric, a woven fabric, a knitted fabric or the like impregnated with at least one kind of latex or the like, and a base fabric or a natural leather generally used for artificial leather or synthetic leather.

The leather-like film used in the present invention is not particularly limited as long as it is a polyurethane resin conventionally used for artificial leather or synthetic leather, and usually solvent type and water-based polyurethane resins are separated. It can be obtained by coating on a pattern paper and drying.

The foam obtained in the present invention, the sheet structure having a foam layer, or the sheet structure in which a foam layer and a leather-like film layer are integrated with each other are prepared by melting the prepolymer (A). Then, a solvent-free moisture-curable hot-melt urethane resin composition obtained by mixing an amine catalyst (B) and water (C), and in some cases an inert gas, and water-foaming is used between release papers or a substrate. Between the top and the release paper, or between the base cloth and the leather-like film, the release paper and the water-repellent treated cloth and the film is uniformly laminated and cooled and solidified, and if it is a method that can be crosslinked and processed, there is no particular limitation. Absent. In addition, after the foam is prepared, it may be adhesively processed with a substrate or / and a leather-like film.

Further, the equipment for foaming the resin is not particularly limited as long as it can uniformly mix a predetermined amount of the inert gas, but it is cooled and thickened by stirring at the time of mixing the inert gas to make it uniform. It is desirable that the mixture can be heated and kept warm in order to avoid flow failure and application failure or adhesion failure when foaming is not performed or when the base material or film is processed as a foam layer.

The foaming degree of the foamed layer of the foamed product of the present invention can be appropriately adjusted according to its application, and is not particularly limited as long as it does not impair the texture or the strength. For example, for artificial leather use or synthetic leather use, the foaming degree is preferably in the range of 1.5 to 2.5 times. The "foaming degree" here means the ratio of the volume of the resin before foaming (V ₁ ) to the volume of the resin after foaming (V ₂ ), that is, V ₂ / V ₁ .

Surface treatment of the foam or sheet structure of the present invention by known or conventional lamination or coating,
Alternatively, various processing methods such as buffing processing are not limited at all.

As described above, according to the present invention, a solventless moisture-curable hot melt urethane resin composition having excellent adhesiveness, hydrolysis resistance and heat resistance, and foam obtained by using the urethane resin composition A body and a sheet structure using the body can be provided.

[0085]

EXAMPLES The present invention will now be described in more detail with reference to examples, but the present invention is by no means limited to these examples. In the following, parts and%
All are by weight unless otherwise specified.
Various properties of the resin were measured according to the following methods.

[Production Method of Skin Film 1] Crisbon NY324 which is a solvent type urethane resin for synthetic leather skin.
(Manufactured by Dainippon Ink and Chemicals, Inc.)
AC-6001 (manufactured by Dainippon Ink and Chemicals, Inc.), methyl ethyl ketone (MEK), and dimethylformamide (DMF) were used with a knife coater so that the coating amount was 100 g / m ² (wet) on the release paper. After applying evenly, dry at 70 ℃ for 1 minute, then at 120 ℃ 2
After being dried for a minute, a skin film 1 having a thickness of 30 μ was prepared.

[Method of Measuring Softening Point] The softening point of each prepolymer obtained in Examples and Comparative Examples was measured by a differential calorimeter (DS).
C) was used and the temperature was raised at a rate of 5 ° C./min in a nitrogen atmosphere.

[Measurement Method of Adhesiveness] A hot-melt cloth tape was applied to the surface of the sheet structure with the skin film at 130 ° C. for 5 minutes.
After thermocompression bonding for 2 seconds, Tensilon (head speed: 20
The peel strength was measured using 0 mm / min).

[Measurement Method of Hydrolysis Resistance] The sheet structure with the skin film was subjected to a hydrolysis resistance test (jungle test conditions: 70 ° C., relative humidity 95%, kept for 12 weeks), and then a hot-melt cloth was applied to the skin. After thermocompression bonding the tape at 130 ℃ for 5 seconds, Tensilon (head speed: 200mm
/ Min) was used to measure the peel strength to observe the retention rate and the change in appearance after evaluation, and the evaluation was made according to the following criteria. ◯: No change in appearance after the jungle test. X: There is a change in appearance after the jungle test.

[Measurement Method of Heat Resistance] After subjecting the sheet structure with the skin film to a heat resistance test (test condition: 120 ° C., holding for 500 hours), 1 piece of hot melt cloth tape was applied to the skin.
After thermocompression-bonding at 30 ° C. for 5 seconds, the peel strength was measured using Tensilon (head speed: 200 mm / min), the retention rate and the appearance change after the evaluation were observed, and evaluated according to the following criteria. ◯: No change in appearance after the test. X: There is a change in appearance after the test.

Example 1 Method for Producing Structure 1 with Skin Film Polytetramethylene glycol having a number average molecular weight of 1400 in a 1-liter 4-necked flask (hereinafter referred to as PTMG14
00 parts), adipic acid (abbreviated as AA in the table), and hexanediol (abbreviated as HG in the table) of polyester polyol having a number average molecular weight of 2000
0 parts and polypropylene glycol having a number average molecular weight of 1500 (MN1500, functional group number 3, Mitsui Chemicals, Inc.)
10% of the product) is heated to 120 ° C under reduced pressure and the water content is 0.05%.
It was dehydrated until. After cooling to 40 ° C., 30 parts of 4,4′-diphenylmethane diisocyanate (MDI) was added, the temperature was raised to 90 ° C., and the reaction was continued for 3 hours until the NCO content became constant to obtain prepolymer 1. . The viscosity at 125 ° C. in a cone and plate viscometer was 9000 mPa · s, and the NCO content was 2.5% by weight. The resulting Prepolymer 1 is heated to 120 ° C. and melted to 120 ° C.
Nitrogen gas is blown in while heating with 0.10 part of POLYCAT-8 (manufactured by Air Products Japan; N, N-dimethylcyclohexylamine (DMCHA)) with respect to 100 parts of prepolymer 1, and water. To 0.0
It was confirmed from the volume that 5 parts of the mixture was mixed and foamed about 2.3 times. Immediately, it is applied on the surface film 1 with a thickness of 50μ, laminated with a polyurethane-impregnated non-woven fabric, cooled, and allowed to stand for 5 days in an environment of a temperature of 23 ° C and a relative humidity of 65%. Structure 1
Got Sheet-like structure 1 with a skin film of the present invention
The results of the evaluation of the properties are shown in Table 1, and they were excellent in adhesiveness, heat resistance, and hydrolysis resistance.

Example 2 Method for Producing Structure 2 with Epidermal Film 70 parts of PTMG1400, 30 parts of polyester polyol having a number average molecular weight of 2000 of adipic acid and hexanediol were placed in a 1-liter 4-necked flask, and MN
100 parts of 1500 was heated to 120 ° C. under reduced pressure to obtain a water content of 0.
It was dehydrated until it became 05%. After cooling to 40 ° C, 4,4 '
-Diphenylmethane diisocyanate (MDI) 50
After the addition, the temperature was raised to 90 ° C., and the reaction was continued for 3 hours until the NCO content became constant to obtain a prepolymer 2. Viscosity at 125 ° C with a cone-plate viscometer is 9500 mPas
-The NCO content in s was 2.3% by weight. The prepolymer 2 obtained is heated to 120 ° C. and melted to 120 ° C.
Nitrogen gas is blown in while heating at 0.10 parts of POLYCAT-8 with respect to 100 parts of prepolymer 2,
It was confirmed from the volume that about 0.05 times the amount of water was foamed by adding 0.05 part of water and mixing. Immediately, it is applied on the skin film 1 with a thickness of 50 μm, a polyurethane-impregnated non-woven fabric is attached, cooled, and left for 5 days in an environment of a temperature of 23 ° C. and a relative humidity of 65% to obtain a sheet-like structure with a skin film. Got 2. The results of characteristic evaluation of the sheet-shaped structure with a skin film 2 of the present invention are shown in Table 1, and it was excellent in adhesiveness, heat resistance and hydrolysis resistance.

Example 3 Method for Producing Structure 3 with Skin Film In a 1-liter 4-necked flask, 50 parts of propylene glycol having a number average molecular weight of 1000 (hereinafter, abbreviated as PPG1000), adipic acid and hexanediol were used. 50 of polyester polyol having a number average molecular weight of 2000
Parts and 10 parts of MN1500 were dehydrated by heating to 120 ° C. under reduced pressure until the water content became 0.05%. After cooling to 40 ° C., 4,4′-diphenylmethane diisocyanate (M
After 30 parts of DI) was added, the temperature was raised to 90 ° C. and the reaction was continued for 3 hours until the NCO content became constant to give Prepolymer 3
Got Viscosity at 125 ° C with a cone and plate viscometer is 8
The NCO content was 2.1% by weight at 500 mPa · s. The prepolymer 3 thus obtained was heated to 120 ° C. to be melted, and nitrogen gas was blown into the prepolymer 3 while heating at 120 ° C., to 100 parts of the prepolymer 3, 0.10 part of POLYCAT-8 and 0 parts of water were added. It was confirmed from the volume that about 0.05 times the amount of foaming was obtained by adding and mixing 0.05 part. Immediately, it is applied on the skin film 1 with a thickness of 50 μm, a polyurethane-impregnated non-woven fabric is pasted and cooled, and the temperature is 23 ° C.
It was left for 5 days in an environment of relative humidity of 65% to obtain a sheet-shaped structure 3 with a skin film. The results of evaluation of the properties of the sheet-shaped structure 3 with a skin film of the present invention are shown in Table 1, and were excellent in adhesiveness, heat resistance, and hydrolysis resistance.

Example 4 Method for Producing Structure 4 with Skin Film The prepolymer 1 obtained in Example 1 was heated and melted at 120 ° C. and then heated at 120 ° C. to give a number average molecular weight of 100.
0 propylene glycol (PPG1000) and MN1
500 and dibutylditin dilaurate (DBSNDL)
The prepolymer 1 / MN1500 / PPG1000 /
DBSNDL = 100/10 / 3.0 / 0.1 While mixing with a weight ratio, nitrogen gas was blown into the mixture to obtain POLYCAT-8.
0.10 parts of water and 0.10 parts of water were added and mixed, and it was confirmed from the volume that the foaming was about 2.2 times. Foamed prepolymer 1 was obtained. Immediately, it is applied on the surface film 1 with a thickness of 50μ, laminated with a polyurethane-impregnated non-woven fabric, cooled, and allowed to stand for 5 days in an environment of a temperature of 23 ° C and a relative humidity of 65%. The structure 4 was obtained. The results of evaluation of the properties of the sheet-shaped structure with a skin film 4 of the present invention are shown in Table 1, and were excellent in adhesiveness, heat resistance, and hydrolysis resistance.

Example 5 Method for Producing Structure 5 with Epidermal Film 124 parts of Prepolymer 1 obtained in Example 1 and 10 parts of MN1500 obtained in Example 1 were put in a molten state in a 1-liter 4-necked flask, and γ- 16 parts of phenylaminopropyltrimethoxysilane was added and reacted at 90 ° C. for 2 hours to obtain prepolymer 4, and phosphoric acid ester catalyst (AP-1) was added to 1.
0 part was added and mixed uniformly. The viscosity at 125 ° C. with a cone and plate viscometer was 9000 mPa · s. The resulting prepolymer 4 is heated to 120 ° C. and melted to form 120
Blow nitrogen gas while heating at ℃, prepolymer 4
POLYCAT-8 for 0.10
And 0.10 parts of water were added and mixed to obtain about 2.
It was confirmed from the volume that it foamed four times. Immediately, it is applied on the skin film 1 with a thickness of 50μ, laminated with a polyurethane-impregnated non-woven fabric, cooled, and allowed to stand for 5 days in an environment of a temperature of 23 ° C. and a relative humidity of 65% to form a sheet-like structure with a skin film. I got body 5. The results of evaluating the characteristics of the sheet-shaped structure 5 with a skin film of the present invention are shown in Table 1, and were excellent in adhesiveness, heat resistance, and hydrolysis resistance.

Comparative Example 1 70 parts of polytetramethylene glycol (PTMG1400) having a number average molecular weight of 1400 and 30 parts of a polyester polyol having a number average molecular weight of 2000 of adipic acid and hexanediol were placed in a 1 liter 4-necked flask. Parts were heated under reduced pressure to 120 ° C. and dehydrated until the water content became 0.05%. After cooling to 40 ℃ 4,
After adding 25 parts of 4′-diphenylmethane diisocyanate (MDI), the temperature was raised to 90 ° C. and the reaction was continued for 3 hours until the NCO content became constant to obtain a prepolymer 5.
Viscosity at 125 ° C measured by cone-plate viscometer is 8000m
The NCO content in Pa · s was 2.1% by weight. The resulting prepolymer 5 is heated to 120 ° C. and melted to obtain 12
Nitrogen gas was blown into the prepolymer 5 while heating at 0 ° C., and 0.10 of POLYCAT-8 was added to 100 parts of the prepolymer 5.
And 0.05 part of water were added and mixed to obtain about 2.
It was confirmed from the volume that foaming was performed 0 times. Immediately, it is applied on the skin film 1 with a thickness of 50μ, laminated with a polyurethane-impregnated non-woven fabric, cooled, and allowed to stand for 5 days in an environment of a temperature of 23 ° C. and a relative humidity of 65% to form a sheet-like structure with a skin film. I got body 6. The results of the characteristic evaluation are shown in Table 2. This product had good initial adhesion and hydrolysis resistance, but was poor in heat resistance.

Comparative Example 2 Propylene glycol (P having a number average molecular weight of 2000 was added to a 1-liter 4-necked flask.
PG2000) is 50 parts, and the number average molecular weight of adipic acid and hexanediol having a number average molecular weight of 2000 is 20.
50 parts of the polyester polyol of No. 00 was heated under reduced pressure to 120 ° C. and dehydrated until the water content became 0.05%. 40 ° C
After cooling to 20 ° C., 20 parts of 4,4′-diphenylmethane diisocyanate (MDI) was added, and the temperature was raised to 90 ° C.
Prepolymer 6 was obtained by reacting for 3 hours until the CO content became constant. The cone-plate viscometer had a viscosity at 125 ° C. of 8000 mPa · s and an NCO content of 2.0% by weight. The prepolymer 6 thus obtained is heated to 120 ° C. to be melted, and nitrogen gas is blown in while heating at 120 ° C.,
For 100 parts of prepolymer 6, POLYCAT-
It was confirmed from the volume that 0.18 part of 8 and 0.05 part of water were added and mixed to foam about 2.0 times.
Immediately, it is applied on the surface film 1 with a thickness of 50μ, laminated with a polyurethane-impregnated non-woven fabric, and cooled to a temperature of 23
The sheet-like structure 7 with a skin film was obtained by leaving it for 5 days in an environment of ° C and a relative humidity of 65%. The characteristic evaluation results are shown in Table 2. Although this product has good initial adhesion,
It was inferior in hydrolysis resistance and heat resistance.

Comparative Example 3 70 parts of PTMG1400 and a number average molecular weight of 2000 were added to a 1 liter 4-necked flask.
The number average molecular weight of adipic acid and hexanediol is 2
30 parts of 000 polyester polyols, and MN1
0.5 part of 500 is heated under reduced pressure to 120 ° C.
It was dehydrated to 5%. After cooling to 40 ° C, 4,4'-
After adding 25 parts of diphenylmethane diisocyanate (MDI), the temperature was raised to 90 ° C. and reacted for 3 hours until the NCO content became constant to obtain a prepolymer 7. Viscosity at 125 ° C with a cone-plate viscometer is 7500 mPa · s
Thus, the NCO content became 2.0% by weight. The prepolymer 7 thus obtained was heated to 120 ° C. to be melted, and nitrogen gas was blown into the prepolymer 7 while heating at 120 ° C.
It was confirmed from the volume that 0.10 part of POLYCAT-8 and 0.05 part of water were added to 0 part of the mixture and mixed to foam about 2.0 times. Immediately, it is applied on the skin film 1 with a thickness of 50μ, laminated with a polyurethane-impregnated non-woven fabric, cooled, and allowed to stand for 5 days in an environment of a temperature of 23 ° C. and a relative humidity of 65% to obtain a sheet-like structure with a skin film. Got 8. This product had good initial adhesion and hydrolysis resistance, but was poor in heat resistance.

Comparative Example 4 70 parts of PTMG1400, 30 parts of a polyester polyol having a number average molecular weight of 2000 of adipic acid and hexanediol, and 120 parts of MN1500 were placed in a 1 liter 4-necked flask.
It was dehydrated by heating under reduced pressure to 0 ° C. until the water content became 0.05%.
After cooling to 40 ° C., 25 parts of 4,4′-diphenylmethane diisocyanate (MDI) was added, the temperature was raised to 90 ° C., and the reaction was continued for 3 hours until the NCO content became constant to obtain prepolymer 8. 125 ° C with a cone and plate viscometer
Had a viscosity of 2000 mPa · s and an NCO content of 2.2% by weight. The prepolymer 8 thus obtained is heated to 120 ° C. to be melted, and nitrogen gas is blown into the prepolymer 8 while heating at 120 ° C.
When 0.18 parts of AT-8 and 0.05 part of water were added and mixed, it was confirmed from the volume that the viscosity rapidly increased and almost no foaming occurred. Immediately, it is applied on the skin film 1 with a thickness of 50μ, laminated with a polyurethane-impregnated non-woven fabric, cooled, and allowed to stand for 5 days in an environment of a temperature of 23 ° C. and a relative humidity of 65% to obtain a sheet-like structure with a skin film. Got 9. This product was inferior in foamability due to collapse of foam cells.

[0100]

[Table 1]

Note 1) The hydrolysis resistance values in Tables 1 and 2 are the values measured after 12 weeks under the conditions of 70 ° C. and 95% relative humidity.

[0102]

[Table 2]

[0103]

The solventless moisture-curable hot melt urethane resin composition having excellent durability obtained by the present invention is
If necessary, foaming with water using an inert gas and coating it on the surface material makes it highly flexible,
In addition, since the synthetic leather, which has excellent adhesiveness and durability (especially hydrolysis resistance and heat resistance), can be prepared without solvent, the solvent drying process that was indispensable in the case of conventional solvent type urethane resin And the extraction process is unnecessary, and the problems on the human body, the environmental pollution, the energy cost for evaporating the solvent, and the like can be improved. Further, a solvent-free moisture-curable hot-melt urethane resin composition having excellent durability, a foam, and a sheet structure using the same, which are obtained in the present invention, are used for furniture and automobile applications requiring high durability. In addition to the synthetic leather and artificial leather described in (1), it is extremely practical in a wide range of applications such as adhesives, pressure-sensitive adhesives, sealing agents, paints, coating agents or films or sheets.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) D06N 3/14 DAA D06N 3/14 DAA // (C08G 18/65 C08G 101: 00 101: 00) F term (Reference) 4F055 AA01 BA12 CA06 DA10 EA24 FA16 GA03 GA11 GA28 GA32 4F100 AK51 AK51A AL05A AT00B BA02 CA13 DJ01A EH46 EJ02 EJ02A EJ08A GB33 GB81 JB12A JJ03 JDF01 CB03 DF01 CB03 DF03 CB01 DF01 CB01 DF02 CB01 DF01 DF01 DF01 DF01 DF02 CB01 DF02 CB01 DF01 CB01 DF01 CB01 DF02 CB01 DF01 CB01 DF01 CB01 DF01 CB01 DF01 CB01 DF01 CB01 DF01 CB01 DF01 CB01 DF01 CB01 DF01 CB01 DF01 CB01 DF01 CB01 DF01 CB01 DF01 CB01 DF01 CB01 DF01 CB01 DF01 CB01 DF01 CB01 DF01 DG05 DP12 DP18 HA07 HC12 HC13 HC17 HC46 HC52 HC64 HC67 JA42 KD11 KD12 LA12 LA32 NA03 QA03 RA03 RA07 RA08 RA19

Claims (13)

[Claims] 1. A hot melt urethane prepolymer (A) obtained by reacting a polyol component and a polyisocyanate component [hereinafter referred to as prepolymer (A)], an amine catalyst (B), and water (C). A solvent-free, moisture-curable hot-melt urethane resin composition, wherein a polyfunctional polyol is used as an essential component in the polyol component of the prepolymer (A). 2. The solventless moisture-curable hot melt urethane resin composition according to claim 1, wherein the content of the polyfunctional polyol in the polyol component of the prepolymer (A) is in the range of 1 to 50% by weight. 3. The softening point of the prepolymer (A) is 30 to
The solventless moisture-curable hot melt urethane resin composition according to claim 1, which is in the range of 160 ° C. 4. The solventless moisture-curable hot melt urethane resin composition according to claim 1, wherein the prepolymer (A) is an isocyanate group-terminated and / or alkoxysilyl group-terminated urethane prepolymer. 5. In the polyisocyanate component and the polyol component constituting the prepolymer (A), the equivalent ratio of isocyanate groups and hydroxyl groups (NCO group / OH group equivalent ratio).
Is in the range of 1.1 to 5.0. The solventless moisture-curable hot melt urethane resin composition according to claim 1. 6. A foam produced by water-foaming the solventless moisture-curable hot-melt urethane resin composition according to any one of claims 1 to 5 and then curing it. 7. The solventless moisture-curable hot-melt urethane resin composition according to any one of claims 1 to 5 is mixed with an inert gas in advance, water-foamed, and then cured. A foam characterized by: 8. A foam layer obtained by water-foaming a base material and the solventless moisture-curable hot-melt urethane resin composition according to any one of claims 1 to 5 on the base material and then curing the same. A sheet structure comprising: 9. A base material and the solventless moisture-curable hot-melt urethane resin composition according to any one of claims 1 to 5 on which an inert gas is previously mixed, and water is added. A sheet structure having a foamed layer which is cured after foaming. 10. A base material and a foam layer obtained by water-foaming the solventless moisture-curable hot-melt urethane resin composition according to claim 1 on the base material and then curing the same. And a sheet structure in which a leather-like film layer is integrated with the foam layer. 11. A base material and the solvent-free moisture-curable hot-melt urethane resin composition according to claim 1 are mixed with an inert gas in advance, and water is added to the base material. A sheet structure comprising a foamed layer that has been foamed and then cured, and a leather-like film layer integrated with the foamed layer. 12. A leather-like film, and a solvent-free, moisture-curable hot-melt urethane resin composition according to any one of claims 1 to 5 which is water-foamed and then cured. A sheet structure having a layer. 13. A leather-like film and the solventless moisture-curable hot-melt urethane resin composition according to claim 1 mixed with an inert gas in advance on the film. A sheet structure having a foamed layer which is water-foamed and then cured.