JP3156942B2 - Leather-like sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leather-like sheet having a slimy surface and good feeling. More specifically, polyurethane having excellent physical properties such as mechanical properties and durability obtained by blending and reacting specific components constituting the polyurethane resin in a specific composition and in a specific order, and excellent in processability. By using a resin, a leather-like sheet having a surface slimy touch and a good feeling is provided.

[0002]

2. Description of the Related Art Leather-like sheet materials made of polyurethane as a skin material are widely used as materials for seats for shoes, clothing, furniture, and vehicles such as automobiles. Demands for quality such as heat resistance and heat resistance are becoming more and more advanced. Many attempts have been made to satisfy these required performances by improving the properties of polyurethane resins. As one of the means, for example,
The type of polyurethane and its component composition are being changed.

JP-A-2-26486 discloses a polyester diol having a specific composition and a number average molecular weight of 300 to 5,
A method for producing a sheet-like material comprising impregnating or / and applying a solution in which a coagulation controlling agent having a specific structure is blended with a polyurethane elastomer containing 000 polyoxyalkylene glycol as a component, and coagulating with a non-solvent of the polyurethane It is shown. The publication discloses that polyethylene glycol is contained as a polyoxyalkylene glycol. The resulting sheet-like material has a sponge structure exhibiting good smoothness, flexibility and drape, and is excellent in hydrolysis resistance and bending resistance, and is used as a skin layer of a leather-like sheet. It discloses suitability and claims its superiority.

However, according to the method disclosed in this publication, not only a sheet-like material having good sliminess cannot be obtained, but also the equivalent ratio of NCO / OH, which is a requirement of the present invention, is 0.5 to 1.0.
Polyethylene glycol (E) having an average molecular weight of 5,000 or more via an intermediate OH-terminated diol (C) obtained by reacting in a quantitative relationship such that it becomes 0.99.
It is hardly possible to assume that a sheet having good sliminess can be obtained by reacting

[0005]

As described above, by improving the polyurethane constituting the leather-like sheet, the leather is excellent in feeling, flexibility, cold resistance, heat resistance, durability and surface touch. To provide a sheet-like material.

[0006]

The present invention SUMMARY OF THE INVENTION The polyester, polycarbonate, polymer diols having a number average molecular weight selected from the group consisting of polylactone 500 to 3000 (A) and organic diisocyanate (B ₁₎ and low-molecular chain extender Agent (D) with an equivalent ratio of NCO / OH of 0.5 to
0.99 and made such obtained by reacting with quantitative relationship substantially terminally intermediate diol OH (C), and diphenylmethane-4,4'-diisocyanate (B ₂₎ and an average molecular weight of 5,000 or more Polyethylene glycol (E)
A leather-like sheet material characterized in that the fiber substrate is impregnated and / or coated on the surface with a polyurethane obtained by reacting

The polymer diol (A) is a polyester,
It is selected from the group consisting of polycarbonate and polylactone. Polyether diol is a compound similar to polyethylene glycol (E) having a number average molecular weight of 5,000 or more, which is an essential component of the present invention, and has an affinity for polyethylene glycol (E) and is considered to be an action mechanism of the present invention. This is not suitable for the purpose of the present invention, possibly because a fine microphase separation state cannot be obtained. The number average molecular weight of the polymer diol (A) is from 500 to 3,000, more preferably from 700 to 2,000.
A range of 500 is chosen. If it is less than 500, the leather-like sheet tends to lose its flexibility or the hand feel is unfavorably reduced. Those over 3000
Because the urethane group concentration is inevitably reduced, not only is it difficult to obtain a leather-like sheet having a good balance of feeling, flexibility, cold resistance, heat resistance and durability, but also industrial production of the polymer diol Has disadvantages and is not preferred.

The polymer diol (A) is a polyester,
Polycarbonate and polylactone can be used alone or in a mixture at an arbitrary ratio. In addition, the molecular weight is 50
There is no particular limitation on the use of a low-molecular diol having a molecular weight of less than 0 as long as the object of the present invention is not impaired, but low-molecular linear diols such as ethylene glycol, butanediol, and hexanediol, and aromatic compounds such as xylylene glycol can be used. It is preferable that a component usually used as a chain extender, such as an aromatic diol, is not substantially contained in terms of the feeling, flexibility, and cold resistance of the leather-like sheet.

The polyester diol used in the present invention can be obtained, for example, by reacting a dibasic acid with a diol. Examples of the dibasic acid include aromatic dibasic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, speric acid, azelaic acid, sebacic acid, and brassic acid, aromatic dibasic acids such as isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid. One of the basic acids or a combination thereof can be used. Among them, aliphatic dibasic acids, especially dibasic acids having a methylene chain length of 4 to 8, such as adipic acid, pimelic acid, speric acid, azelaic acid and sebacic acid, are more preferably used. As the diol, ethylene glycol which may be substituted with a lower alcohol, propylene glycol, butanediol, neopentyl glycol,
Aliphatic diols such as methylpentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, dodecanediol, etc., alicyclic diols such as cyclohexanediol, hydrogenated xylylene glycol, xylylene glycol, etc. One or a mixture of two or more aromatic diols is used. Among them, aliphatic diols, especially butane diol, methylpentanediol, hexanediol, heptanediol, methyloctanediol, nonanediol, etc., have a carbon chain length of 4 or more. One to nine aliphatic diols or a mixture of two or more aliphatic diols is preferably used.

[0010] The polycarbonate diol can be obtained, for example, by reacting a carbonate compound with a diol. As the carbonate compound, dimethyl carbonate, diphenyl carbonate, ethylene carbonate and the like can be used. As the diol, ethylene glycol, propylene glycol, butanediol, neopentyl glycol, methylpentanediol, hexanediol, which may be substituted with a lower alcohol,
One or two or more aliphatic diols such as heptanediol, octanediol, nonanediol, decanediol and dodecanediol; alicyclic diols such as cyclohexanediol and hydrogenated xylylene glycol; and aromatic diols such as xylylene glycol. Mixtures of more than one kind are used. Among them, aliphatic diols, especially aliphatic diols having a carbon chain length of 4 to 9, such as butanediol, methylpentanediol, hexanediol, heptanediol, methyloctanediol, and nonanediol Alternatively, a mixture of two or more kinds is suitably used.

Polylactone diols are, for example, poly-
ε-caprolactone diol, poly-trimethyl-ε-
Examples include caprolactone diol and poly-β-methyl-δ-valerolactone diol.

The organic diisocyanate (B ₁ ) is, for example, diphenylmethane-4,4′-diisocyanate,
Aromatic diisocyanates such as 2,4- or 2,6-tolylene diisocyanate, meta- or para-phenylene diisocyanate, 1,5-naphthylene diisocyanate, isophorone diisocyanate, cyclohexane diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, hydrogenated MDI, etc. And the like are used. Among these, as the organic diisocyanate (B ₁ ) to be reacted with the polymer diol (A) and the chain extender (D), the case of diphenylmethane-4,4′-diisocyanate is obtained by coagulating with a non-solvent the surface of a sheet-like material. Slimy touch,
It is preferable because it has a good feel.

The intermediate diol (C) having an OH-terminated end substantially comprises a polymer diol (A), a chain extender (D) and an organic diisocyanate (B ₁ ) having an equivalent ratio of NCO / OH of from 0.5 to 0.5. It is obtained by reacting in a quantitative relationship such that it becomes 0.99. If the equivalent ratio of NCO / OH is less than 0.5, the urethane bond incorporated into the intermediate diol having an OH end substantially varies depending on the molecular weight of the polymer diol (A) and the type of the organic diisocyanate (B ₁ ). Because the amount is too small, or because the molecular weight is too small, it is difficult to balance the surface sliminess, hand, flexibility, cold resistance, heat resistance of the leather-like sheet, and the effect of the present invention is sufficient I can't get it. If the equivalent ratio of NCO / OH exceeds 0.99, the polymer diol (A)
Molecular weight of the organic diisocyanate (B ₁ ), the amount of urethane bonds incorporated into the intermediate diol having a terminal OH is too large, the molecular weight becomes too large, and furthermore, leather-like It is difficult to balance the surface sliminess, feeling, flexibility, cold resistance and heat resistance of the sheet material, and the effect of the present invention cannot be sufficiently obtained.

As the chain extender (D), ethylene glycol, propylene glycol, butanediol, neopentyl glycol, methylpentanediol, hexanediol, heptanediol, octanediol, nonanediol, decane which may be substituted with a lower alcohol may be used. Diols, aliphatic diols such as dodecane diol, cyclohexane diols, alicyclic diols such as hydrogenated xylylene glycol, aromatic diols such as xylylene glycol, and one or a mixture of two or more kinds such as diethylene glycol are used. But aliphatic diols, especially ethylene glycol,
Butanediol is suitably used in terms of the balance of the feeling, flexibility, cold resistance and heat resistance of the leather-like sheet.

The amount of the low molecular chain extender (D) is not particularly limited, but it depends on its molecular structure, the molecular weight of the polymer diol (A), the type of organic diisocyanate, and the NCO / OH equivalent ratio. With respect to the polymer diol (A), an equivalent ratio of (D) / (A) is 0.5 to 7,
Among them, the leather-like sheet obtained from 1 to 5.5 is often suitable in terms of feeling, flexibility, cold resistance and heat resistance.

The molecular weight of polyethylene glycol (E) is 5,000 or more, and more preferably 6,000 to 30,000.
May be more preferably used. If it is less than 5,000, a leather-like sheet having a good texture and having a surface slimy touch, which is the greatest effect of the present invention, cannot be obtained. The molecular weight may be 5,000 or more, but polyethylene glycol exceeding 30,000 is difficult to obtain industrially.

The amount of polyethylene glycol (E) is not particularly limited, but is often used in an amount of 5 to 25 parts by weight, more preferably 7 to 15 parts by weight, per 100 parts by weight of the polymer diol (A).

The amount of diphenylmethane-4,4'-diisocyanate (B ₂ ) to be used is not particularly limited. The viscosity of the polyurethane solution, the molecular weight of the polymer diol (A), the polymer diol (A) and the organic diisocyanate (B ₁ )
Although it depends on the NCO / OH equivalent ratio, the reaction solvent, the polymer diol (A), the low molecular chain extender (D), the moisture contained in the polyethylene glycol (E), etc., usually (B ₁ ) and (B ₂ ) Equivalent ratio of NCO / polymer diol (A), low molecular chain extender (D), and hydroxyl group from polyethylene glycol (E) NCO / OH of 0.95
-1.3, especially 0.97-1.2.

A catalyst is not always necessary when the polymerization method used in the present invention is carried out, but catalysts used in the production of ordinary polyurethanes, for example, metal compounds such as titanium tetraisopropoxide, dibutyltin dilaurate and tin octate And tertiary amines such as tetramethylbutanediamine and 1,4-diaza (2,2,2) bicyclooctane.

As the solvent for the polyurethane obtained by the method used in the present invention, commonly used solvents such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone, toluene, ethyl acetate, methyl ethyl ketone and tetrahydrofuran are used.

The polyurethane obtained by the method used in the present invention may be used in combination with various additives used in conventional polyurethanes, such as flame retardants such as phosphorus compounds and halogen-containing compounds, antioxidants, ultraviolet absorbers, and the like. Pigments,
Dyes, plasticizers, surfactants and the like can be added.

The fibrous base material is obtained from synthetic fibers such as polyamide, polyester, vinylon, polyacrylonitrile and the like, artificial fibers such as rayon, cupra, acetate and the like, or natural fibers such as silk, cotton, wool and hemp. Knitted fabric, woven fabric, non-woven fabric, average single fineness 0.1
Any of nonwoven fabrics in which ultrafine fiber bundles of denier or less are three-dimensionally entangled can be used.

Among them, a nonwoven fabric made of a three-dimensionally entangled ultrafine fiber bundle having an average single fineness of 0.1 denier or less can be suitably applied. The fiber base material was previously treated with a polyurethane resin so that the weight ratio of the ultrafine fiber bundle to the polyurethane was 70/30 to 97/3, and the apparent density was 0.4 to 0.8 g / cm ³ . An impregnated cloth can be more suitably applied.

[0024]

The action mechanism by which the leather-like sheet of the present invention is excellent in hand, flexibility, cold resistance, heat resistance, durability and surface touch is not clear, but the polymer diol (A) And a chain extender (D) and an organic diisocyanate (B ₁ ) obtained at a specific composition ratio. A polyethylene glycol having an urethane group-containing intermediate diol (C) having a number average molecular weight of 5,000 or more, which is substantially OH-terminated. The polyurethane resin phase obtained by reacting with diphenylmethane-4,4'-diisocyanate (B ₂ ) in the co-presence of (E) and a polyethylene glycol phase having a number average molecular weight of 5,000 or more are in an appropriate microphase separation state. Therefore, it is considered that the leather sheet-like material having the polyurethane resin as a skin layer was provided with the preferable characteristics as described above. The leather sheet of the present invention thus obtained is useful for various uses such as clothing, shoes, bags, furniture, vehicle interior materials, and miscellaneous goods.

[0025]

The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto.

Example 1 To 5650 parts by weight of N, N-dimethylformamide, 1000 parts by weight of polybutylene adipate having a number average molecular weight of 2,000, 249 parts by weight of polyhexylene carbonate having a number average molecular weight of 2,000, and 70.4 parts by weight of ethylene glycol were added. Dissolve. 415 parts by weight of diphenylmethane-4,4'-diisocyanate are gradually added with stirring (NC
O / OH = 0.94). After the addition, the reaction was carried out at an internal temperature of 80 ° C. for 3 hours. As a result, diphenylmethane-4,4′-diisocyanate was completely reacted, and an intermediate having a substantially terminal OH was obtained.

Subsequently, 125 parts by weight of polyethylene glycol having a number average molecular weight of 20,000 was added, diphenylmethane-4,4'-diisocyanate was gradually added, and the reaction was carried out. When NCO / OH = 1.05, the solution was dissolved. Since the viscosity (30 ° C.) became 400 poise, the mixture was cooled to obtain a polyurethane solution.

Seika Seven BS1001 (trade name: Dainichi Seika) was added to 1000 parts by weight of the polyurethane solution obtained above.
07 parts by weight, Rezamine CUT30 additive (trade name: Dainichi Seika) 23 parts by weight, Rezamine CUT40 (trademark: Dainichi Seika) 12 parts by weight, N, N-dimethylformamide 45
0 parts by weight were added and mixed to obtain a urethane compound liquid.

The urethane-blended liquid obtained above was mixed with polyethylene propylene adipate glycol / diphenylmethane-4,4'-diisocyanate / ethylene glycol in a three-dimensional entangled nonwoven fabric of ultrafine fiber bundle of polyethylene terephthalate having an average single fineness of 0.08 dr. 1/5 / equivalent ratio
The polyurethane polymerized in Step 4 was coated in a porous state on a porous fibrous base material having a thickness of 1.2 mm and an apparent density of 0.42 g / cm ³ by knife coating so as to have a thickness of 350 g / m ^2. It was poured into water and allowed to solidify.

The obtained wet-leather-like sheet has a surface slimy touch and is excellent in texture, thus achieving the object of the present invention.

Comparative Example 1 A polyurethane solution was obtained in the same manner as in Example 1 except that polyethylene glycol having a number average molecular weight of 20,000 was not used, and a wet leather-like sheet was obtained as a polyurethane compounding solution. It has no touch and poor texture, and the effect of using the specific polyethylene glycol of the present invention is obvious.

Comparative Example 2 Seika Seven BS was added to 1000 parts by weight of a solution obtained by adding 125 parts by weight of polyethylene glycol having a number average molecular weight of 20,000 to the polyurethane solution obtained in the same manner as in Comparative Example 1.
1001 (trade name: Dainichi Seika) 107 parts by weight, rezamine CUT30 additive (trademark: Dainichi Seika) 23 parts by weight, rezamin CUT40 (trademark: Dainichi Seika) 12 parts by weight,
N, N-dimethylformamide (450 parts by weight) was added and mixed to obtain a urethane blended liquid.

Polyethylene propylene adipate glycol / 4,4'- is added to a three-dimensional entangled nonwoven fabric of ultrafine fiber bundle of polyethylene terephthalate having an average single fineness of 0.08 dr.
Polyurethane obtained by polymerizing diphenylmethane diisocyanate / ethylene glycol at an equivalent ratio of 1/5/4 was contained in a porous state, having a thickness of 1.2 mm and an apparent density of 0.4.
The urethane-blended liquid obtained above was applied to a 2 g / cm ³ porous fibrous substrate by a knife coat so as to be 350 g / m ^2, and subsequently poured into water to solidify.

The obtained wet-leather-like sheet had a waxy substance migrated on its surface to produce spots, was tacky, and was of no practical value.

Comparative Example 3 N, N-dimethylformamide (5642 parts by weight), polybutylene adipate having a number average molecular weight of 2000 (1,000 parts by weight), polyhexylene carbonate having a number average molecular weight of 2,000 (249 parts by weight), ethylene glycol (70.4 parts by weight),
Polyethylene glycol 12 having a number average molecular weight of 20,000
Dissolve 5 parts by weight. Diphenylmethane-4,4 '
The diisocyanate is added slowly with stirring to give NCO /
When OH = 1.04, the solution viscosity (30 ° C.) becomes 39.
Since the solution became 0 poise, it was cooled to obtain a polyurethane solution.

Using the polyurethane solution obtained above, wet coagulation was carried out in the same manner as in Example 1. However, the obtained wet leather-like sheet had irregularities on its surface and was not practically usable.

As described above, the effect of the polyurethane obtained by using the specific polyethylene glycol of the present invention in the specific order is obvious.

Example 2 800 parts by weight of poly (3-methylpentanediol adipate) having a number average molecular weight of 2,000, 450 parts by weight of polyhexylene carbonate having a number average molecular weight of 2,000, and ethylene glycol 70 in 5650 parts by weight of N, N-dimethylformamide Dissolve 4 parts by weight. 328 parts by weight of diphenylmethane-4,4'-diisocyanate are slowly added with stirring (NCO / OH = 0.73). After the addition,
When the reaction was carried out at an internal temperature of 80 ° C. for 3 hours, diphenylmethane-4,4′-diisocyanate was completely reacted,
A substantially OH-terminated intermediate was obtained.

Subsequently, 150 parts by weight of polyethylene glycol having a number average molecular weight of 14,000 and diphenylmethane-4,4'-diisocyanate were added to carry out a reaction.
Solution viscosity (30 ° C) when CO / OH = 1.07
Was 410 poise, and the mixture was cooled to obtain a polyurethane solution.

Seika Seven BS780 (trade name: Dainichi Seika) was added to 1000 parts by weight of the polyurethane solution obtained above.
7 parts by weight, 23 parts by weight of Rezamin CUT30 additive (trade name: Dainichi Seika), 12 parts by weight of Rezamin CUT40 (trademark: Dainichi Seika), N, N-dimethylformamide 450
The parts by weight were added and mixed to obtain a urethane compound liquid.

The above-obtained urethane blend liquid was applied to a three-dimensional entangled nonwoven fabric of a 6-nylon ultrafine fiber bundle having an average single fineness of 0.008 dr by polyethylene-propylene adipate glycol / diphenylmethane-4,4'-diisocyanate /
Polyurethane obtained by polymerizing ethylene glycol at an equivalent ratio of 1/5/4 is contained in a porous state in a thickness of 1.1 mm,
^{3 on} a porous fibrous substrate with an apparent density of 0.37 g / cm 3
Coating was carried out with a knife coat so as to have a concentration of 50 g / m ^2, and subsequently, the mixture was poured into water and solidified.

The obtained wet leather-like sheet had a surface slimy touch and was excellent in texture, and achieved the object of the present invention.

Comparative Example 4 800 parts by weight of poly (3-methylpentanediol adipate) having a number average molecular weight of 2,000, 450 parts by weight of polyhexylene carbonate having a number average molecular weight of 2,000, and ethylene glycol 70 in 5650 parts by weight of N, N-dimethylformamide Dissolve 4 parts by weight. 108 parts by weight of diphenylmethane-4,4'-diisocyanate are slowly added with stirring (NCO / OH = 0.25). After the addition,
When the reaction was carried out at an internal temperature of 80 ° C. for 3 hours, diphenylmethane-4,4′-diisocyanate was completely reacted,
A substantially OH-terminated intermediate was obtained.

Subsequently, 150 parts by weight of polyethylene glycol having a number average molecular weight of 14,000 and diphenylmethane-4,4'-diisocyanate were added to carry out a reaction.
Solution viscosity (30 ° C) when CO / OH = 1.06
Became 390 poise, and cooled to obtain a polyurethane solution.

The wet coagulation was carried out in the same manner as in Example 2 except that 1000 parts by weight of the polyurethane solution obtained above was used. However, the obtained wet leather-like sheet had irregularities on the surface and was not practically usable. Was.

As described above, the specific range of NCO / OH of the present invention
The effect of the polyurethane obtained via the substantially terminal-OH intermediate obtained by satisfying the above conditions is evident.

Comparative Example 5 A wet leather-like sheet was obtained in the same manner as in Example 2 except that polyethylene glycol having a number average molecular weight of 2,000 was used instead of polyethylene glycol having a number average molecular weight of 14,000. It does not have a good texture, and the effect of using the polyethylene glycol having a specific molecular weight of the present invention is clear.

[0048]

By using the polyurethane of the present invention, it is possible to provide a leather-like sheet having a surface sliminess and a good balance of feeling, flexibility, cold resistance, heat resistance and durability. it can.

Continuation of the front page (51) Int.Cl. ⁷ identification code FI C09D 175/06 C09D 175/06 (58) Investigated field (Int.Cl. ⁷ , DB name) D06N 3/14 B32B 27/12 C08J 9 / 28 C08G 18/10 C08G 18/48 C09D 175/06

Claims (1)

(57) [Claims] A number average molecular weight selected from the group consisting of polyester, polycarbonate, and polylactone is 500 to 500.
3000 polymer diol (A), organic diisocyanate (B ₁ ) and low molecular chain extender (D) were mixed with NCO /
An intermediate diol (C) having a substantially terminal OH obtained by reacting in a quantitative relationship such that the equivalent ratio of OH is 0.5 to 0.99, and diphenylmethane-4,4'-diisocyanate ( A leather-like sheet material characterized in that polyurethane obtained by reacting B ₂ ) with polyethylene glycol (E) having an average molecular weight of 5,000 or more is impregnated or / and surface-coated on a fiber base material.