JPH11302356A - Method for producing polyurethane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method capable of extremely stably producing a polyurethane excellent in light fastness such as light yellowing resistance and light dyeing fastness, and washing fastness by solution polymerization. SOLUTION: When a production raw material comprising a polymer polyol (a), a chain extender (b), an organic diisocyanate (c) and a hindered amine compound (d) represented by the following general formula (1) is subjected to solution polymerization. And a solution polymerization in the presence of 0.1 to 50 parts by weight of a phosphorus compound based on 100 parts by weight of the hindered amine compound (d). Embedded image (In the formula, R ¹ is an alkylene group, R ² is a hydrogen atom or a methyl group, and x represents an integer of 4 to 20.)

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a polyurethane, which can produce a polyurethane having excellent light fastness such as light yellowing resistance and light fastness to fastness and washing fastness extremely stably by solution polymerization. About. The polyurethane solution obtained by the production method of the present invention can be stably stored in a solution state, and does not lose fluidity during storage, so that industrial handling is extremely easy.

[0002]

2. Description of the Related Art A leather-like sheet made of a fibrous base material and a polyurethane elastic material has a texture similar to that of natural leather, and has excellent flexibility, abrasion resistance, mechanical strength, and good workability. Widely used as artificial leather.
However, such leather-like sheet materials generally produced by a wet method have poor light resistance, and are discolored by sunlight, nitric oxide gas, or automobile exhaust gas, or have reduced strength or elongation. Its use is severely limited due to its drawbacks. In order to improve such a defect of the leather-like sheet, a method of adding a light resistance improver to polyurethane, a method of using a polyurethane having a group having a light resistance function introduced in a molecular chain, and the like have been proposed. I have. The above method, for example, hindered phenol-based, phosphite-based antioxidants,
A method of adding one or more of various stabilizers such as a hindered amine-based or benzotriazole-based ultraviolet absorber and a hydrazine derivative or a triazine derivative to a polyurethane. A polyurethane composition containing such a stabilizer is added. When a sheet material is produced by a wet method using the above method, the added stabilizer elutes from the polyurethane into the coagulation bath, and the effect of the stabilizer is not sufficiently exhibited.
Further, when the sheet is dry-cleaned or washed, the effect of the stabilizer is easily lost, so that the sheet cannot withstand long-term use. Examples of the above method include a method using a hindered amine compound as a part of a chain extender and / or a terminal terminator, a method using a piperidine compound as a part of a raw material for polyurethane polymerization, and a method using a bisphenol monoester compound at a terminal of the polyurethane. There have been proposals for ways to introduce it, such as the long-term effect persistence,
Poor compatibility with other polyurethanes. Therefore, a polyurethane using a hindered amine compound represented by the following general formula (1) as a production raw material has been proposed. When the polyurethane is used, a leather-like sheet having excellent light fastness and washing fastness can be obtained. (Japanese Patent Laid-Open No. 4-25
No. 8642).

[0003]

Embedded image

Wherein R ¹ is an alkylene group, R ² is a hydrogen atom or a methyl group, and x is an integer of 4 to 20.

[0005]

However, when polyurethane is produced by solution polymerization using the hindered amine compound represented by the above general formula (1) as a production raw material, the production ratio of the hindered amine compound and the like are determined. Under some conditions, it was found that the polymerization solution gelled during the polymerization, so that polyurethane could not be produced stably. Furthermore, even if polyurethane can be produced without gelling of the polymerization solution during polymerization, the obtained polyurethane solution loses fluidity in a short period of time during storage, and is used for production of a leather-like sheet. It turned out to be unusable. Therefore, the leather-like sheet material is a method commonly used when industrially manufactured by a wet method, that is, a polyurethane solution produced in large quantities at a time by solution polymerization is stored for a relatively long time. While the method used for the production of leather-like sheet material cannot be adopted,
Each time a leather-like sheet is manufactured, a polyurethane solution must be prepared, and industrial handling is extremely poor.

An object of the present invention is to make it possible to extremely stably produce a polyurethane having excellent light fastness such as light yellowing resistance and light dyeing fastness and washing fastness by solution polymerization.
Another object of the present invention is to provide a method for producing polyurethane, which can obtain a polyurethane solution that can be stably stored in a solution state.

[0007]

As a result of the study by the present inventors to achieve the above object, in the presence of a specific amount of a phosphorus compound, a polymer polyol, a chain extender, an organic diisocyanate and the above-mentioned general formula ( When the hindered amine compound represented by 1) is solution-polymerized, polyurethane can be extremely stably produced without gelling during the polymerization,
Furthermore, they have found that the resulting polyurethane solution can be stored extremely stably without losing fluidity during storage, and based on these findings, completed the present invention.

That is, the present invention relates to a polymer polyol (a), a chain extender (b), and an organic diisocyanate (c).
And when a production material comprising the hindered amine compound (d) represented by the following general formula (1) is subjected to solution polymerization, 0.1 to 50 parts by weight of the phosphorus compound is added to 100 parts by weight of the hindered amine compound (d). A solution polymerization in the presence of a polyurethane.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The polymer polyol (a) used in the present invention includes, for example, polyester polyol, polyether polyol, polycarbonate polyol, polyester polycarbonate polyol and the like. These polymer polyols may be used alone or in combination of two or more. Among these, it is preferable to use polyester polyols and polyether polyols.

The above polyester polyol is subjected, for example, to a direct esterification reaction or transesterification reaction between a dicarboxylic acid or an ester-forming derivative thereof such as an ester and an anhydride thereof and a polyol, or a ring-opening of a lactone, according to a conventional method. It can be produced by polymerization.

As the polyol constituting the polyester polyol, those generally used in the production of polyester can be used. For example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol , 2-methyl-1,3-propanediol, 2,
2-diethyl-1,3-propanediol, 1,3-butylene glycol, 1,4-butanediol, 2-methyl-1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 3-methyl -1,5-
Pentanediol, 1,6-hexanediol, 1,8
-Octanediol, 2-methyl-1,8-octanediol, 2,7-dimethyl-1,8-octanediol, 1,9-nonanediol, 2-methyl-1,9-nonanediol, 2,8- C2-C15 such as dimethyl-1,9-nonanediol and 1,10-decanediol
Aliphatic diols of 1,4-cyclohexanediol,
Alicyclic diols such as cyclohexanedimethanol and dimethylcyclooctanedimethanol; 1,4-bis (β
And aromatic dihydric alcohols such as (-hydroxyethoxy) benzene. These diols may be used alone or in combination of two or more.
Further, a trifunctional or higher functional polyol can be used together with the above-mentioned diol in a small amount as long as the effects of the present invention are not impaired. Examples of the trifunctional or more functional polyol include glycerin, trimethylolethane, trimethylolpropane, trimethylolbutane, butanetriol, hexanetriol, and pentaerythritol. These polyols may be used alone or in combination of two or more.

As the dicarboxylic acid constituting the polyester polyol, those generally used in the production of polyesters can be used. For example, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid , Sebacic acid, dodecanedioic acid, methylsuccinic acid, 2-methylglutaric acid, 3-methylglutaric acid, trimethyladipic acid, 2-methyloctanedioic acid,
Aliphatic dicarboxylic acids having 4 to 12 carbon atoms such as 3,8-dimethyldecandioic acid and 3,7-dimethyldecandioic acid; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; terephthalic acid, isophthalic acid, orthophthalic acid; An aromatic dicarboxylic acid such as naphthalenedicarboxylic acid or an ester-forming derivative thereof can be given. These dicarboxylic acids may be used alone or in combination of two or more.

Examples of the lactone include ε-caprolactone, β-methyl-δ-valerolactone and the like.

As the polyether polyol, for example, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, poly (methyltetramethylene glycol) and the like can be mentioned. These polyether polyols may be used alone or in combination of two or more.

As the polycarbonate polyol, for example, those obtained by reacting a polyol with a carbonate compound such as dialkyl carbonate, alkylene carbonate, diaryl carbonate and the like can be used. As the polyol constituting the polycarbonate diol, the polyols exemplified above as the constituent components of the polyester polyol can be used. Examples of the dialkyl carbonate include dimethyl carbonate, diethyl carbonate, and the like. Further, as the alkylene carbonate, ethylene carbonate and the like can be mentioned, and as the diaryl carbonate, diphenyl carbonate and the like can be mentioned.

As the polyester polycarbonate polyol, for example, those obtained by simultaneously reacting a polyol, a dicarboxylic acid and a carbonate compound can be used. Alternatively, those obtained by previously synthesizing a polyester polyol and a polycarbonate polyol by the above-described method and then reacting them with a carbonate compound or with a polyol and a dicarboxylic acid can be used.

The number average molecular weight of the high molecular polyol (a) is preferably from 500 to 5,000, and
000 is more preferable. The number average molecular weight of the high molecular polyol referred to in the present specification is JIS.
It is a number average molecular weight calculated based on the hydroxyl value measured according to K1577.

The high molecular polyol (a) preferably has a number of hydroxyl groups per molecule of the high molecular polyol in the range of 2.00 to 2.10. When the number of hydroxyl groups per molecule of the high molecular polyol is within the above range, a polyurethane excellent in washing fastness, solvent resistance and the like can be obtained.

As a method for producing a polymer polyol having a hydroxyl group number of more than 2.00 per molecule, for example, a component having two functional groups in one molecule among the above-mentioned raw material components of the polymer polyol is used. A polymer polyol produced by using together a component having three or more functional groups in one molecule at an arbitrary ratio may be used alone, or a polymer having two hydroxyl groups per molecule may be used. A mixture in which a diol and a polymer polyol having more than two hydroxyl groups per molecule are mixed at an arbitrary ratio may be used.

The chain extender (b) used in the present invention is not particularly limited, and any of the chain extenders conventionally used for producing ordinary polyurethanes may be used.
It is preferable to use a low molecular compound having a molecular weight of 400 or less and having two or more active hydrogen atoms capable of reacting with an isocyanate group in the molecule. For example, ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,4-bis (β-hydroxyethoxy) benzene, 1,4-cyclohexanediol, bis (β-hydroxyethyl) terephthalate And diols such as xylylene glycol; diamines such as hydrazine, ethylenediamine, propylenediamine, xylylenediamine, isophoronediamine, piperazine and derivatives thereof, phenylenediamine, tolylenediamine, xylenediamine, adipic dihydrazide, and isophthalic dihydrazide; Examples include amino alcohols such as aminoethyl alcohol and aminopropyl alcohol. These low molecular compounds may be used alone or in combination of two or more.

The organic diisocyanate (c) used in the present invention is not particularly limited, and any organic diisocyanate conventionally used for producing ordinary polyurethane may be used. For example, 4,4'- Diphenylmethane diisocyanate, tolylene diisocyanate, phenylene diisocyanate, xylylene diisocyanate, 1,5-naphthylene diisocyanate, 3,
Aromatic diisocyanates such as 3'-dichloro-4,4'-diphenylmethane diisocyanate and toluylene diisocyanate; aliphatic or alicyclic rings such as hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate and hydrogenated xylylene diisocyanate Examples include the formula diisocyanate. These organic diisocyanates may be used alone or in combination of two or more.

In the present invention, the hindered amine compound (d) represented by the general formula (1) is used as a raw material for producing polyurethane. In the general formula (1), the alkylene group represented by R ¹ has ¹ to 10 carbon atoms.
Is preferred, and an alkylene group having 1 to 6 carbon atoms is more preferred. As the alkylene group, for example,
Examples thereof include a methylene group, an ethylene group, a propylene group, and a butylene group. Of these, an ethylene group is preferable. In the above general formula (1), x is 4 to 20
And preferably an integer of 6 to 15. When x is smaller than 4, it is necessary to incorporate a large amount of the hindered amine compound represented by the general formula (1) in order to obtain a sufficient effect. It becomes unsuitable for use as a raw material for producing a leather-like sheet, for example, due to a decrease in compatibility with polyurethane. On the other hand, when x is larger than 20, the molecular weight of the hindered amine compound represented by the general formula (1) becomes too large, which adversely affects the polymerization reaction of the polyurethane and deteriorates the physical properties of the obtained polyurethane.

The hindered amine compound (d) represented by the general formula (1) is 1- (2-hydroxyethyl)
It can be obtained by condensation polymerization of -4-hydroxy-2,2,6,6-tetramethylpiperidine with dicarboxylic acid or dicarboxylic acid ester. For example, 1- (2
-Hydroxyethyl) -4-hydroxy-2,2,6
And polycondensates of 6-tetramethylpiperidine and dimethyl succinate.

In producing the polyurethane by reacting the polymer polyol (a), the chain extender (b), the organic diisocyanate (c) and the hindered amine compound (d), the ratio of each raw material used is determined by the ratio of the polyurethane to the polyurethane. Although it is appropriately determined in consideration of the hardness to be imparted, etc., the organic diisocyanate (c) is added to 1 mol of active hydrogen atoms contained in the polymer polyol (a), the chain extender (b) and the hindered amine compound (d). It is preferred that the components are reacted at such a ratio that the isocyanate groups contained in the above) are 0.9 to 1.2 mol.

In the production raw material comprising the polymer polyol (a), the chain extender (b), the organic diisocyanate (c) and the hindered amine compound (d), the content of the component (d) is 0.1 to 30% by weight. Preferably, it is 0.2 to 20% by weight. By using the component (d) within the above range, a polyurethane having excellent light resistance and various physical properties can be produced more stably.

The phosphorus compound used in the present invention includes, for example, phosphoric acid, phosphoric acid ester, phosphorous acid, phosphite, phosphonic acid, phosphonic acid ester and the like. Two or more can be used. Among these phosphorus compounds, it is preferable to use compounds of the following general formulas (2) to (5).

(R ³ O) _n P (O) _m (OH) _3-n (2)

Wherein m is 0 or 1, n is 0, 1 or 2, and R ³ is a hydrocarbon group.

[0029]

Embedded image

(Where a and j are each 0 or 1
And R ^{4 to} R ⁶ each represent a hydrocarbon group. However,
When a is 1, at least one of R ^{4 to} R ⁶ is an aliphatic hydrocarbon group or an alicyclic hydrocarbon group. )

[0031]

Embedded image

(Where b, c, k and l are each 0
Or 1 and R ⁷ and R ⁸ each represent a hydrocarbon group. )

[0033]

Embedded image

(Where d, e, p and q are each 0
Or represents 1, R ^{9 to} R ¹² each represent a hydrocarbon group, and R ¹³ represents a divalent hydrocarbon group. However, when both d and e are 1, at least one of R ^{9 to} R ¹² is an aliphatic hydrocarbon group or an alicyclic hydrocarbon group. )

In the general formulas (2) to (5), R
³ The hydrocarbon group to R ¹² represent preferably an alkyl group or an aryl group having 1 to 30 carbon atoms. For example, methyl group, ethyl group, propyl group, butyl group, pentyl group,
Hexyl group, octyl group, isooctyl group, 2-ethylhexyl group, nonyl group, decyl group, dodecyl group, isodecyl group, aliphatic hydrocarbon group such as octadecyl group; alicyclic hydrocarbon group such as cyclohexyl group; Nonylphenyl group, cresyl group, 2,4-di-butylphenyl group, 2,6-di-t-butyl-4-methylphenyl group, naphthyl group, benzyl group, 3,5-di-t-butylphenyl group And other aromatic hydrocarbon groups.
The aromatic hydrocarbon group may have a substituent such as a halogen atom, an alkyl group, an alkoxy group, a phenoxy group or a hydroxyl group on the aromatic ring. In the above general formula (5), the divalent hydrocarbon group represented by R ¹³ has 1 to 1 carbon atoms.
50 divalent hydrocarbons are preferable, for example, a divalent aliphatic hydrocarbon group such as a methylene group, an ethylene group, a propylene group, and a butylene group; a divalent alicyclic hydrocarbon such as a cyclohexene group; a phenylene group; Biphenylene group, 4,
Examples thereof include divalent aromatic hydrocarbon groups such as a 4'-butylidene-bis (3-methyl-6-t-butylphenyl) group and a 4,4'-isopropylenediphenyl group. The divalent aromatic hydrocarbon group may have a substituent such as a halogen atom, an alkyl group, an alkoxy group, a phenoxy group or a hydroxyl group on the aromatic ring.

Examples of the phosphorus compound represented by the general formula (2), that is, phosphorous acid or phosphoric acid, or mono- or diesters thereof include, for example, phosphorous acid; phosphoric acid; dimethyl phosphite; Diethyl phosphate, diisopropyl phosphite, di-n-butyl phosphite, diisobutyl phosphite, di-n-ethylhexyl phosphite,
Dilauryl phosphite, dioleyl phosphite, distearyl phosphite, diphenyl phosphite, monomethyl phosphite, monoethyl phosphite, monoisopropyl phosphite,
Mono-n-butyl phosphite, monoisobutyl phosphite,
Phosphites such as mono-n-ethylhexyl phosphite, monolauryl phosphite, monooleyl phosphite, monostearyl phosphite, monophenyl phosphite; dimethyl phosphate, diethyl phosphate, diisopropyl phosphate, Di-n-butyl phosphate, diisobutyl phosphate, di-n-ethylhexyl phosphate, dilauryl phosphate, dioleyl phosphate, distearyl phosphate, diphenyl phosphate,
Monomethyl phosphate, monoethyl phosphate, monoisopropyl phosphate, mono-n-butyl phosphate, monoisobutyl phosphate, mono-n-ethylhexyl phosphate, monolauryl phosphate, monooleyl phosphate, monostearyl phosphate,
Phosphoric esters such as monophenyl phosphate can be mentioned.

Examples of the phosphorus compound represented by the general formula (3) include trimethyl phosphite, triethyl phosphite, tributyl phosphite, trioctyl phosphite, tris (2-ethylhexyl) phosphite, and trinonyl phosphite. , Tris (decyl) phosphite, tridodecyl phosphite, tris (octadecyl) phosphite, tricyclohexyl phosphite, diphenylisooctyl phosphite, phenyl diisooctyl phosphite, diphenyl isodecyl phosphite, phenyl diisodecyl phosphite, etc. Phosphite triesters; trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tris (2-ethylhexyl) phosphate, Phosphate triesters such as (decyl) phosphate, tridodecyl phosphate, tris (octadecyl) phosphate, tricyclohexyl phosphite, diphenylisooctyl phosphite, phenyldiisooctyl phosphate; dimethyl phenylphosphonite, diethyl phenylphosphonite Diesters of phosphonous acid derivatives such as phenyl, dibutyl phosphite, dioctyl phenylphosphonite, didodecyl phenylphosphonite, bis (octadecyl) phenylphosphonite, dicyclohexyl phenylphosphonite, diphenyl phenylphosphonite; phenylphosphon Acid dimethyl, diethyl phenylphosphonate, dibutyl phenylphosphonate, dioctyl phenylphosphonate, didodecyl phenylphosphonate, Ruhosuhon acid bis (octadecyl), phenyl phosphonic acid dicyclohexyl, phenyl phosphonic acid diphenyl, 3,5-di -t-
And diesters of phosphonic acid derivatives such as diethyl butyl-4-hydroxybenzylphosphonate.

Examples of the phosphorus compound represented by the general formula (4) include didodecylpentaerythritol diphosphite, bis (octadecyl) pentaerythritol diphosphite, bis (nonylphenyl) pentaerythritol diphosphite, and bis (nonylphenyl) pentaerythritol diphosphite. (2,4-di-t-
Phosphite triesters such as butylphenyl) pentaerythritol diphosphite and bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite; phosphorus such as bis (octadecyl) pentaerythritol diphosphate Acid triester and the like.

As the phosphorus compound represented by the general formula (5), for example, 4,4′-butylidene-bis (3-
Phosphorous triesters such as methyl-6-t-butylphenylditridecyl) phosphite and 4,4'-isopropylenediphenoltetrakis (tridecyl) diphosphite; tetrakis (2,4-di-t-butylphenyl) -4 And diesters of phosphonous acid derivatives such as 4,4'-biphenylenephosphonite.

Among the above phosphorus compounds, phosphorous acid, diphenyl phosphite, distearyl phosphite, diphenyl phosphate, bis (octadecyl) pentaerythritol diphosphite, bis (nonylphenyl) pentaerythritol diphosphite , Bis (2,4-di-t-
Butylphenyl) pentaerythritol diphosphite, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, tris (decyl) phosphite, tris (2-ethylhexyl) phosphate, bis (octadecyl) ) Pentaerythritol diphosphate, tetrakis (2,4-di-t-butylphenyl) -4,4′-biphenylenephosphonite,
Preferred are diethyl phenylphosphonate, diethyl 3,5-di-t-butyl-4-hydroxybenzylphosphonate and the like.

The amount of the phosphorus compound to be used is 100% for the hindered amine compound (d) represented by the general formula (1).
0.1 to 50 parts by weight, preferably 0.2 to 10 parts by weight, more preferably 0.5 to 5 parts by weight with respect to parts by weight.
Parts by weight. If the amount of the phosphorus compound is less than 0.1 parts by weight, the resulting polyurethane solution loses fluidity within 72 hours, even if it gels during solution polymerization or does not gel during polymerization, This causes problems in storage stability such as extremely difficult handling. If the amount of the phosphorus compound exceeds 50 parts by weight, the resulting polyurethane will have poor hydrolysis resistance.

The production method of the present invention comprises the above component (a),
It is necessary to carry out solution polymerization of a raw material for producing polyurethane comprising the components (b), (c) and (d) in the presence of a phosphorus compound. The phosphorus compound may be added before the polyurethane polymerization, and the method of addition, the timing of addition, and the like are not particularly limited. For example, the polymer polyol (a)
And hindered amine compound (d) in advance,
It is preferable to stir at 0 to 150 ° C. for 30 minutes to 5 hours under reduced pressure or normal pressure. In addition, it can be previously dissolved together with the hindered amine compound (d) in a solvent used for solution polymerization.

The production method of the present invention can employ a polymerization method generally performed by solution polymerization of polyurethane. For example, the polyurethane can be polymerized by adding the polymer polyol (a), the chain extender (b), the organic diisocyanate (c) and the hindered amine compound (d) all at once to the solvent, or the polymer can be prepared in advance. A method in which a polyol (a) and an organic isocyanate (c) are reacted in a solvent to synthesize a prepolymer, and then a chain extender (b) and a hindered amine compound (d) are added to polymerize polyurethane, a so-called prepolymer method. Can be used.

The solvent used for the solution polymerization may be any one which dissolves or uniformly disperses the polyurethane obtained by the polymerization. For example, N, N'-dimethylformamide, N, N'-dimethylacetamide, Examples thereof include organic solvents such as tetrahydrofuran and dimethyl sulfoxide, and one or more of these may be used in combination. Among them, it is preferable to use N, N'-dimethylformamide.

The polyurethane solution obtained by the production method of the present invention may further contain, if necessary, known additives such as an antioxidant, an ultraviolet absorber, a dye, a pigment, a filler and a coagulation regulator. can do.

The polyurethane solution obtained by the production method of the present invention can be suitably used as a raw material for producing a leather-like sheet. For example, after impregnating and applying the obtained polyurethane solution to a fibrous substrate, the substrate is introduced into a coagulation bath containing a non-solvent of polyurethane, wet coagulated, then washed with water and dried to form a leather-like sheet. Things can be manufactured. In this case, the polyurethane solution obtained by the production method of the present invention may be used alone, or another polyurethane solution may be mixed and used. Examples of the fibrous base material used for producing the leather-like sheet include ordinary fibers, for example, synthetic fibers such as polyester, polyamide, polyacrylonitrile, polyolefin, polyvinyl alcohol, and regenerated cellulose; natural fibers; or fibers in a special form, for example, ,polyester,
Fabrics such as fiber entangled non-woven fabrics, fiber napped woven fabrics, and laminated fabrics of non-woven fabrics and woven fabrics composed of fibers selected from ultra-fine fibers such as polyamide and polyacrylonitrile, or ultra-fine fiber bundle fibers, and porous array special fibers. Can be mentioned. When using ultrafine fiber-generating fibers, split-split fibers, etc., before solvent impregnation / application of polyurethane solution or after coagulation of polyurethane, solvent extraction treatment with toluene, trichlorene, perchrene, etc. or containing alkali or activated carbon Division processing using hot water or the like may be performed.

When a leather-like sheet is produced using the polyurethane solution obtained by the production method of the present invention, a leather-like sheet having a texture and appearance similar to natural leather and having little discoloration or deterioration even after long-term use is obtained. can get. Further, the compound having a hindered amino group does not fall out of the system by dry cleaning or washing, and is particularly suitable for use in clothing, shoes, interiors, car seats, and the like.

[0048]

EXAMPLES The present invention will now be described specifically with reference to examples, but the present invention is not limited to these examples. In Examples, polymerization stability,
Storage stability, film strength retention, and light yellowing resistance were evaluated by the following methods.

[Polymerization stability] In the solution polymerization of polyurethane using N, N'-dimethylformamide as a solvent,
A gel was formed during the polymerization reaction and the viscosity increased until the stirring blade became insufficiently rotated, and a case where the gel was not gelled was evaluated as “O”.

[Storage stability] The N, N'-dimethylformamide solution of the polyurethane obtained by solution polymerization was allowed to stand at room temperature for 72 hours, and "x" indicates that the polyurethane solution lost fluidity, Was evaluated as "O" when no loss was observed.

[Film Strength Retention] A dry film having a thickness of 0.1 mm was prepared from the obtained N, N'-dimethylformamide solution of polyurethane, and the tensile strength was measured by a Tensilon tensile tester. Further, the tensile strength after irradiating the film with light with a fade tester (carbon arc, 63 ° C.) for 80 hours was measured, and the retention of the tensile strength after the light resistance test was evaluated by the following formula.

Film strength retention (%) = [tensile strength after light irradiation (kg) / tensile strength before light irradiation (kg)] × 1
00

[Light Yellowing Resistance] A sheet-like material obtained by impregnating and coagulating a non-woven fabric with an N, N'-dimethylformamide solution of the obtained polyurethane is irradiated with light using a fade tester (carbon arc, 63 ° C.) for 80 hours. After that, the degree of discoloration of the sheet was determined using a gray scale.
The smaller the value is, the more discoloration is shown.

REFERENCE EXAMPLE 1 495 parts by weight of polytetramethylene glycol having a number average molecular weight of 2000 and 164 parts by weight of polycaprolactone glycol having a number average molecular weight of 2000 were mixed at 100 ° C. with 6 parts by weight.
After uniformly stirring under reduced pressure for 0 minutes, the prepolymer is reacted with 26 parts by weight of ethylene glycol and 250 parts by weight of 4,4'-diphenylmethanedidiisocyanate in 1500 parts by weight of N, N'-dimethylformamide. Obtained. Further, an N, N′-dimethylformamide solution containing 4,4′-diaminodiphenylmethane is
0.99 based on the residual isocyanate groups of the prepolymer
The molar equivalent was added, and the solid content was adjusted to 25% at 30 ° C.
After the reaction, the viscosity was adjusted to 400 poise, and N, N'- containing 8 parts of methanol as a reaction terminator was used.
A dimethylformamide solution was added to obtain a 380 poise polyurethane solution.

Example 1 495 parts by weight of polytetramethylene glycol having a number average molecular weight of 2,000, 164 parts by weight of polycaprolactone glycol having a number average molecular weight of 2,000, and the above formula (1)
Wherein R ¹ is CH ₂ CH ₂ and R ² is CH ₃ , and the number-average molecular weight is 3300, a hindered amine compound [dimethyl succinate and 1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6 -Polycondensate with tetramethylpiperazine] 75 parts by weight (corresponding to 7.1% by weight of the raw material for producing polyurethane) and 0.75 parts by weight of diphenyl phosphite (corresponding to 1 part by weight based on 100 parts by weight of the hindered amine compound) ) Was uniformly stirred under reduced pressure at 100 ° C for 60 minutes, and then 26 parts by weight of ethylene glycol and 1500 parts by weight of N, N'-dimethylformamide were added.
A prepolymer was obtained by reacting with 256 parts by weight of diphenylmethane didiisocyanate. In addition, 4,
An N, N'-dimethylformamide solution containing 4'-diaminodiphenylmethane was added in an amount of 0.99 molar equivalents based on the remaining isocyanate groups of the prepolymer, and the reaction was carried out at 30 ° C for 8 hours at a solid content of 25% to give 400%. The viscosity was adjusted to a poise, and an N, N'-dimethylformamide solution containing 8 parts of methanol as a reaction terminator was added to obtain a 375 poise polyurethane solution. Gelation did not occur during the polymerization reaction, and polyurethane could be produced stably. Also, the obtained polyurethane solution is
The fluidity was not lost even after standing for 72 hours. A dry film having a thickness of 0.1 mm was prepared from this polyurethane solution, and subjected to a Tensilon tensile test.
cm ² . The film was irradiated with light using a fade tester (carbon arc, 63 ° C.) for 80 hours and then subjected to a tensile test to find that it was 190 kg / cm ² (strength retention 90%). 40 parts by weight of highly fluid polyethylene and 60 parts by weight of 6-nylon are melt-spun and drawn to obtain a 4-denier fineness, 51 mm multicomponent fiber (6-nylon is an ultrafine fiber component). , Through each step of needle punch, apparent density 0.160g / c
An m ³ fiber entangled nonwoven fabric was prepared. The nonwoven fabric was heated and the sea component polyethylene was melted and heat-fixed to obtain a fiber-entangled nonwoven fabric having an apparent density of 0.285 g / cm ³ , which had been smoothed on both sides. Using the 25% polyurethane solution obtained in Reference Example 1, the above polyurethane and the polyurethane of Reference Example 1 were mixed at a weight ratio of 1: 9, and alcohol-modified silicone and N, N′-dimethylformamide were further mixed. To prepare an impregnating liquid comprising 12% of polyurethane solid content, 0.5% of alcohol-modified silicone and 87.5% of N, N'-dimethylformamide. The impregnating liquid is impregnated into the fiber-entangled nonwoven fabric, and after removing excess impregnating liquid on the surface, the impregnating liquid is applied so that the amount of polyurethane becomes 120 g / m ^2, and then N, N′−
The sheet was coagulated in a coagulation bath containing an aqueous solution containing 30% dimethylformamide, and washed with water to obtain a sheet-like material obtained by coagulating polyurethane into a porous structure. The sheet was treated in hot toluene to dissolve and remove the polyethylene component of the multicomponent fiber to obtain a sheet comprising a 6-nylon ultrafine fiber bundle fiber entangled nonwoven fabric and a porous polyurethane coating layer. The surface of this sheet is buffed with sandpaper to expose bubbles inside the coating layer to give a suede-like appearance, and then a suede-like leather-like sheet obtained by finishing treatment has a good surface touch. Met. Fade tester (carbon arc, 63 ° C) on this leather-like sheet
Light irradiation for 80 hours to evaluate the light yellowing resistance,
The evaluation value was No. 5, which was excellent in light yellowing resistance.

Example 2 The number average molecular weight obtained from 1,5-methylpentanediol, trimethylolpropane and adipic acid was 200.
0, 400 parts by weight of a polyester polyol having a hydroxyl group number of 2.02 per molecule, R ¹ in the above general formula (1) is CH ₂ CH ₂ , R ² is CH ₃ , and the number average molecular weight is 3300. 105 parts by weight of a hindered amine compound (polycondensate of dimethyl succinate and 1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperazine) (20% by weight of the raw material for producing polyurethane)
And bis (octadecyl) pentaerythritol diphosphite ("PEP-" manufactured by Asahi Denka Kogyo KK)
8 ") 5.25 parts by weight (hindered amine compound 100
Was stirred under reduced pressure at 100 ° C. for 60 minutes and then in 1,800 parts by weight of N, N′-dimethylformamide, 4,4′-diphenylmethanedidiisocyanate was added. 175 parts by weight and 31 parts by weight of ethylene glycol were reacted at 70 ° C. for 4 hours,
40 with 4,4'-diphenylmethane didiisocyanate
The viscosity was increased to 0 poise. Then 1 part by weight of citric acid,
N, N'- containing 8 parts by weight of methanol as a reaction terminator
Add dimethylformamide solution, solid content concentration 25%
To obtain a 350 poise polyurethane solution. Gelation did not occur during the polymerization reaction, and polyurethane could be produced stably. The results of evaluating the storage stability, film strength retention and light yellowing resistance of this polyurethane solution in the same manner as in Example 1 are shown in Table 1 below.

Example 3 400 parts by weight of a polyester diol obtained from 1,5-methylpentanediol and adipic acid having a number average molecular weight of 2,000, a hydroxyl group number of 2.00 per molecule, and the general formula (1) R ¹ is CH ₂ CH ₂ , R ² is CH ₃
7 parts by weight of a hindered amine compound having a number average molecular weight of 3300 [a polycondensate of dimethyl succinate and 1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperazine] 1.0% by weight of polyurethane production raw material) and tetrakis (2,4
-Di-t-butylphenyl) -4,4'-biphenylenephosphonite (manufactured by Adekastab Co.) at 0.1 parts by weight (corresponding to 1.4 parts by weight with respect to 100 parts by weight of the hindered amine compound) at 60 ° C for 60 hours. After stirring uniformly under reduced pressure for 20 minutes, the mixture was reacted with 225 parts by weight of 4,4'-diphenylmethanedidiisocyanate and 43 parts by weight of ethylene glycol at 20 ° C. for 10 hours in 2025 parts by weight of N, N′-dimethylformamide. And 4,4'-diphenylmethane didiisocyanate to increase the viscosity to 450 poise.
Next, N containing 8 parts by weight of methanol as a reaction terminator,
An N′-dimethylformamide solution was added to obtain a polyurethane solution of 420 poise at a solid content concentration of 25%. Gelation did not occur during the polymerization reaction, and polyurethane could be produced stably. The results of evaluating the storage stability and the film strength retention of this polyurethane solution in the same manner as in Example 1 are shown in Table 1 below. Three-dimensional consisting of 75 parts by weight of polyethylene terephthalate and 25 parts by weight of low-density polyethylene, 50 islands (polyethylene terephthalate is an island component), and an apparent density of 0.150 g / cm ³ consisting of 4.5 denier sea-island fibers After shrinking the entangled nonwoven fabric in warm water so as to have an area shrinkage of 30%, impregnating with a 10% aqueous solution of polyvinyl alcohol, drying and immersing in toluene to dissolve polyethylene, and a bundle of ultrafine fibers is formed. An entangled nonwoven fabric was obtained. An impregnating solution prepared using the above 25% polyurethane solution and comprising 13% of polyurethane, 1% of alcohol-modified silicone and 86% of N, N′-dimethylformamide was impregnated into the nonwoven fabric.
After removing the excess impregnating solution on the surface, the solution is coagulated in a coagulation bath of an aqueous solution containing 30% N, N'-dimethylformamide, washed with warm water to elute and remove the polyvinyl alcohol, and thereby the polyethylene terephthalate ultrafine is removed. A sheet-like material containing a porous polyurethane in a fiber bundle fiber-entangled nonwoven fabric was obtained. This sheet base was sliced into two parts, the back surface was buffed and the thickness was adjusted, and then the front surface was buffed with sandpaper to raise the thickness to 0.7 mm.
Was obtained. After repeating dry-cleaning treatment of this sheet-like material five times using perchlen,
A suede-like leather-like sheet was obtained by brushing the surface of the hair and brushing the hair. The leather-like sheet was evaluated for light yellowing resistance in the same manner as in Example 1, and the results are shown in Table 1 below.

Comparative Example 1 Polyurethane was produced in the same manner as in Example 1 except that no phosphorus compound was used. As a result, gelation occurred during the polymerization of the polyurethane, which was useful for producing a film or a leather-like sheet. A usable polyurethane solution could not be obtained.

Comparative Example 2 Polyurethane was produced in the same manner as in Example 2 except that no phosphorus compound was used. As a result, gelation occurred during the polymerization of the polyurethane, which was useful for producing a film or a leather-like sheet. A usable polyurethane solution could not be obtained.

Comparative Example 3 Polyurethane was produced in the same manner as in Example 3 except that no phosphorus compound was used. Gelation did not occur during polymerization of the polyurethane. Upon standing at room temperature for 72 hours, the polyurethane solution lost its fluidity and could not be used for producing films or leather-like sheets.

[0061]

[Table 1]

[0062]

According to the production method of the present invention, light yellowing resistance,
Polyurethane excellent in light fastness such as light fastness to dyeing and washing fastness can be extremely stably produced by solution polymerization. Furthermore, the polyurethane solution obtained by the production method of the present invention can be stably stored in a solution state, and does not lose fluidity during storage, so that industrial handling is extremely easy.

Claims (2)

[Claims] 1. A solution raw material comprising a polymer polyol (a), a chain extender (b), an organic diisocyanate (c) and a hindered amine compound (d) represented by the following general formula (1): And a solution polymerization in the presence of 0.1 to 50 parts by weight of a phosphorus compound based on 100 parts by weight of the hindered amine compound (d). Embedded image (In the formula, R ¹ is an alkylene group, R ² is a hydrogen atom or a methyl group, and x represents an integer of 4 to 20.) 2. In a production raw material comprising a polymer polyol (a), a chain extender (b), an organic diisocyanate (c) and a hindered amine compound (d) represented by the above general formula (1), a hindered amine compound ( d)
The method for producing a polyurethane according to claim 1, wherein the content ratio of the polyurethane is 0.1 to 30% by weight.