JP2012051973A - Polyurethane resin composition for synthetic leather, and synthetic leather using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyurethane resin composition for synthetic leather from which a synthetic leather skin layer excellent in hydrolysis resistance and abrasion resistance is obtained, and a synthetic leather using the same.
In a polyurethane resin composition for synthetic leather containing a polyisocyanate (A), a polyol (B), and a chain extender (C), the polyol (B) contains sebacic acid in a dibasic acid component. A polyurethane resin composition for synthetic leather, comprising a polyester polyol (B-1) to be used in an amount of ˜100 mol%.
[Selection figure] None

Description

  The present invention relates to a polyurethane resin composition for a synthetic leather from which a synthetic leather skin layer excellent in abrasion resistance and hydrolysis resistance is obtained, and a synthetic leather using the same.

  Polyurethane resin is used as a material for synthetic leather because of its excellent mechanical properties and durability. In particular, as a polyurethane synthetic leather, a polyurethane resin composition mainly using an adipate polyester polyol is widely used for the synthetic leather.

For example, Patent Document 1 discloses a polyurethane resin composition obtained by reacting a polyester polyol composed of 2,4-diethyl-1,5-pentanediol and adipic acid with 4,4′-diphenylmethane diisocyanate, and the same. Synthetic leather obtained using is disclosed (see especially the examples).
However, in the case of synthetic leather using a polyurethane resin composition using a polyester polyol mainly composed of adipic acid as a dibasic acid component, degradation due to hydrolysis occurs, cracks or breakage of the surface film due to wear, There were problems, such as being unusable.

  Synthetic leather using a polyurethane resin composition using polycarbonate polyol alone or in combination with other polyester polyols has been developed as a means for solving such drawbacks, but polycarbonate polyol is expensive and therefore only partially used. In some cases, the effect is not sufficiently exhibited, and when used alone, the cost is significantly increased, the use is limited to only a part, and it is impossible to develop a large application industrially.

  Thus, although polyurethane resin compositions using polyester polyols from the industrial world, polyurethane resin compositions for synthetic leather that are excellent in mechanical strength, hydrolysis resistance and abrasion resistance are strongly demanded, The current situation has not yet been found.

Japanese Patent Laid-Open No. 11-292952

  The subject of this invention is providing the polyurethane resin composition for synthetic leather from which the synthetic leather skin layer excellent in hydrolysis resistance and abrasion resistance is obtained, and synthetic leather using the same.

  In order to obtain a polyurethane resin composition having improved hydrolysis resistance and abrasion resistance, the present inventors have intensively studied the polyol, and have completed the present invention.

  That is, the present invention provides a polyurethane resin composition for synthetic leather containing a polyisocyanate (A), a polyol (B), and a chain extender (C), wherein the polyol (B) is sebacic acid in a dibasic acid component. A polyurethane resin composition for synthetic leather, comprising a polyester polyol (B-1) using 60 to 100 mol% of the synthetic leather, and a synthetic leather using the same.

  The polyurethane resin composition for synthetic leather of the present invention comprises a synthetic leather skin layer excellent in hydrolysis resistance and abrasion resistance by using a polyester polyol containing a specific amount of sebacic acid in a dibasic acid component, and It is possible to provide a synthetic leather having

  First, the polyisocyanate (A) used in the present invention will be described.

  The polyisocyanate (A) is not particularly limited. For example, 1,5-naphthalene diisocyanate, 3,3′-dimethyl-4,4′-biphenyl diisocyanate, polymethylene polyphenyl isocyanate, 2,4-tolylene diene. Isocyanate, 2,6-tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, a mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate, xylene-1,4-diisocyanate, xylene-1,3- Diisocyanate, p-phenylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate, cyclohexane Down diisocyanate, and the like. These may be used in combination and used alone, or two or more kinds. Among these, it is preferable to use 4,4'-diphenylmethane diisocyanate from the viewpoint of durability and mechanical strength.

  Next, the polyol (B) used in the present invention will be described.

  The said polyol (B) contains the polyester polyol (B-1) which uses 60-100 mol% of sebacic acids in a dibasic acid component. The acid value is preferably 2 or less, more preferably 0.5 or less, preferably a hydroxyl value of 25 to 75, more preferably 45 to 60.

  The polyester polyol (B-1) is obtained by reacting a glycol component with a dibasic acid component, and uses 60 to 100 mol% of sebacic acid in the dibasic acid component.

  The number average molecular weight of the polyester polyol (B-1) is preferably 1500 to 4500. In addition, the said number average molecular weight shows the value measured by GPC of polystyrene conversion.

  The glycol is preferably an aliphatic short-chain diol having 2 to 18 carbon atoms, such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1, 3-butanediol, 2-methyl 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 3-methyl 1,5-pentanediol, 1,6-hexanediol, 2,2,4-trimethyl 1,3-pentanediol, 2-ethyl 1,3-hexanediol, 2-methyl 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1, Examples thereof include 12-octadecanediol, and these can be used alone or in combination of two or more. The side chain-containing diol is preferably contained in the glycol component in an amount of 20 to 100 mol%.

  The side chain-containing diol is preferably 1,2-propylene glycol, neopentyl glycol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2-methyl-1,8. -Octanediol etc. are mentioned.

  As said dibasic acid, a sebacic acid is contained 60-100 mol%, Preferably it is 70-100 mol%, More preferably, it contains 80-100 mol%. In this case, the dibasic acid that can be used in combination with less than 40 mol% is preferably an aliphatic dibasic acid, for example, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, 1,10-decane. A single carboxylic acid, 1,12-dodecanedicarboxylic acid or a combination of two or more thereof can be used. In addition, aromatic dibasic acids such as phthalic acid, isophthalic acid, terephthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid or anhydrides thereof may be used alone or in combination of two or more thereof within a range not impairing the effects of the present invention. Can be used.

  Although it does not specifically limit as a manufacturing method of the said polyester polyol (B-1), For example, in presence of the esterification catalyst normally used for the said dibasic acid component containing sebacic acid and the said glycol component. A method of producing by dehydration condensation reaction is preferred.

  The polyester polyol (B-1) is preferably 20 to 100% by weight, more preferably 50 to 100% by weight in the polyol component (B) from the viewpoint of improving scratch resistance, hydrolysis resistance and durability. It is included.

  Other polyols (B-2) that can be used in combination with the polyester polyol (B-1) include ordinary polyester polyols composed of a dibasic acid component such as adipic acid and the short-chain diol component, Examples include polyester polyols obtained by ring-opening polymerization of lactones using chain glycol as a reaction initiator, polyether polyols such as polytetramethylene glycol and polypropylene glycol, and the like. Of course, these polyols used in combination may have an average functional group number exceeding 2.0, and can be used within a range not impairing the effects of the present invention.

  Next, the chain extender (C) used in the present invention will be described.

  Although it does not specifically limit as said chain extender (C), A C2-C18 aliphatic short chain diol can be used preferably. Examples of the aliphatic short-chain diol having 2 to 18 carbon atoms include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, -Methyl 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 3-methyl 1,5-pentanediol, 1,6-hexanediol, 2,2,4- Trimethyl 1,3-pentanediol, 2-ethyl 1,3-hexanediol, 2-methyl 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-octadecanediol, etc. These may be used alone or in combination of two or more.

  In order to produce a polyurethane resin from the polyol (B) containing the polyester polyol (B-1), the polyisocyanate (A), and the chain extender (C), known methods such as a known prepolymer method and a one-shot method are known. The manufacturing method can be used. The equivalent ratio of (A) / (B) + (C) between the polyisocyanate (A) and the polyol (B) used is preferably NCO / OH = 0.98 to 1.1. If the NCO / OH ratio is smaller than 0.98, the hydrolysis resistance and wear resistance are lowered. If the NCO / OH ratio exceeds 1.1, the weather resistance of the resulting polyurethane resin is deteriorated. , Causing discoloration and impractical use.

  If necessary, the polyurethane resin composition of the present invention comprises a reactivity modifier, an antioxidant, an ultraviolet absorber, a hydrolysis inhibitor, a filler, a colorant (pigment, dye), a reinforcing agent, a release agent, and a flame retardant. An additive such as an antistatic agent may be added.

  The synthetic leather of the present invention is a fiber base material or a fiber base material impregnated with a polyurethane resin with an adhesive, preferably a polyurethane resin adhesive, with the polyurethane film obtained from the polyurethane resin composition of the present invention as a skin layer. Any fiber laminate may be used as long as it is bonded together.

  The bonding process at that time is a dry lamination method or a wet lamination method. That is, the adhesive is applied to a film or a fiber substrate obtained from the polyurethane resin composition of the present invention, dried if necessary, and bonded and bonded.

  The fiber substrate can be used without any particular limitation as long as it is a generally used fiber substrate. The material is, for example, synthetic fibers such as polyamide, polyester, polyacryl and the like; natural fibers such as wool, silk, cotton and hemp; semi-synthetic fibers such as acetate and rayon; and mixed fibers thereof Examples thereof include fiber sheet-like materials such as woven and knitted fabrics and nonwoven fabrics. Furthermore, those in which a microporous material is formed by coating (including foaming coating) or impregnating an organic solvent-based or aqueous polyurethane resin on these fiber sheet-like materials.

  The polyurethane resin-based adhesive may be applied by any conventionally known method, for example, a gravure roll, a reverse roll, a rod, a knife over roll, a spray or the like. Preferably, the coating thickness may be 5 to 100 μm after drying, and is preferably 5 to 50 μm. Moreover, although the application surface of this adhesive agent may be either a polyurethane resin film or a fiber base material, it is usually preferably applied on the polyurethane resin film.

  The polyurethane resin adhesive can be widely used as long as it is a conventionally known drying method. For example, a hot air dryer, an infrared irradiation dryer, a microwave irradiation dryer, or a drying device using at least two of these in combination can be used. The drying conditions are not particularly limited as long as the moisture or solvent in the polyurethane resin-based adhesive is evaporated, and the drying is generally performed at 60 to 150 ° C. for 10 seconds to 2 minutes. However, overdrying is not preferable because it not only causes thermal deterioration and deterioration of the polyurethane resin film, fiber base material, and adhesive layer, but also promotes the curing reaction between the polyurethane resin and the polyisocyanate compound, resulting in poor adhesion, and insufficient drying. In this case, moisture and solvent do not evaporate sufficiently, which may cause problems such as floating of the skin layer, penetration of the resin into the fiber base material, and insufficient adhesion. The drying condition is preferably 70 to 130 ° C. for about 20 seconds to 1 minute.

The adhesive layer formed on either the film and / or the fiber base material is overlapped with the film or the fiber base material, and is preferably laminated with a pressure roll preferably at a pressure of 0.1 to 30 kgf / cm ^2. A fiber laminate having an initial adhesive property, particularly a synthetic leather, is obtained. Thereafter, the curing reaction between the polyurethane resin and the polyisocyanate compound is completed by aging in an atmosphere preferably at 20 to 60 ° C. as necessary, and further, strong adhesiveness, that is, heat and moisture resistance, cold resistance. , Heat resistance and water adhesion resistance can be obtained.

  Further, the synthetic leather of the present invention may be further subjected to post-processing such as surface treatment and scouring.

  The synthetic leather of the present invention is a material used for daily goods such as shoes and bags.

  EXAMPLES Next, although an Example and a comparative example are given and this invention is demonstrated concretely, this invention is not limited to this. The parts in Examples and Comparative Examples represent parts by weight unless otherwise specified.

[Synthesis of polyester polyol (PES1-8)]
[Synthesis Example 1] PES1
A 5-liter four-necked flask was charged with 950 parts of ethylene glycol, 500 parts of 1,2-propylene glycol, 3950 parts of sebacic acid, and 0.06 part of tetrabutyl titanate, and reacted at 220 ° C. for 24 hours in a nitrogen stream. After the reaction, the obtained polyester polyol (PES1) had an acid value of 0.12 and a hydroxyl value of 54.2.

[Synthesis Example 2] PES2
Into a 5-liter four-necked flask, 1290 parts of 1,4-butanediol, 460 parts of 1,2-propylene glycol, 3650 parts of sebacic acid, and 0.06 part of tetrabutyl titanate were charged, and the reaction was carried out at 220 ° C. for 24 hours under a nitrogen stream. Reacted. After the reaction, the obtained polyester polyol (PES2) had an acid value of 0.18 and a hydroxyl value of 56.3.

[Synthesis Example 3] PES3
In a 5-liter four-necked flask, 1540 parts of 1,6-hexanediol, 580 parts of neopentyl glycol, 3280 parts of sebacic acid, and 0.06 part of tetrabutyl titanate were charged and reacted at 220 ° C. for 24 hours in a nitrogen stream. . After the reaction, the obtained polyester polyol (PES3) had an acid value of 0.25 and a hydroxyl value of 54.7.

[Synthesis Example 4] PES4
In a 5-liter four-necked flask, 2170 parts of 3-methylpentanediol, 3230 parts of sebacic acid, and 0.06 part of tetrabutyl titanate were charged and reacted at 220 ° C. for 24 hours in a nitrogen stream. After the reaction, the obtained polyester polyol (PES4) had an acid value of 0.11 and a hydroxyl value of 55.4.

[Synthesis Example 5] PES5
A 5-liter four-necked flask was charged with 1,30 parts of 1,4-butanediol, 480 parts of 1,2-propylene glycol, 3040 parts of sebacic acid, 550 parts of adipic acid, and 0.06 part of tetrabutyl titanate. The reaction was carried out at 220 ° C. for 24 hours. After the reaction, the obtained polyester polyol (PES5) had an acid value of 0.18 and a hydroxyl value of 55.9.

[Synthesis Example 6] PES6
In a 5-liter four-necked flask, 930 parts of 1,4-butanediol, 930 parts of 2-methyl-1,3-propanediol, 2940 parts of sebacic acid, 600 parts of isophthalic acid, and 0.06 part of tetrabutyl titanate were charged. The reaction was performed at 220 ° C. for 24 hours under a nitrogen stream. After the reaction, the obtained polyester polyol (PES6) had an acid value of 0.20 and a hydroxyl value of 56.1.

[Comparative Synthesis Example 1] PES7
The reaction was performed in the same manner as in Synthesis Example 1 except that sebacic acid was changed to adipic acid. The obtained polyester polyol (PES7) had an acid value of 0.21 and a hydroxyl value of 54.9.

[Comparative Synthesis Example 2] PES8
The reaction was performed in the same manner as in Synthesis Example 2 except that sebacic acid was changed to adipic acid. The obtained polyester polyol (PES8) had an acid value of 0.23 and a hydroxyl value of 55.0.

[Comparative Synthesis Example 3] PES9
A 5 liter four-necked flask was charged with 1590 parts of ethylene glycol, 1420 parts of sebacic acid, 2390 parts of adipic acid, and 0.06 part of tetrabutyl titanate, and reacted at 220 ° C. for 24 hours in a nitrogen stream. After the reaction, the obtained polyester polyol (PES9) had an acid value of 0.15 and a hydroxyl value of 55.0.

<Synthesis of polyurethane resin solution (U1-8)>
[Example 1] U1
929 parts of the polyester polyol PES1 shown in the synthesis example, 25 parts of the chain extender 1,4-butanediol and 17 parts of the chain extender ethylene glycol are mixed in a 5 liter four-necked flask, and 1212 parts of dimethylformamide is added and uniform. Then, 255 parts of 4,4′-diphenylmethane diisocyanate was added and reacted at 80 ° C., and then 1616 parts of methyl ethyl ketone was added to obtain a polyurethane resin solution (U1) having a solid content of 30% and a viscosity of 540 poise.

[Example 2] U2
Mix 894 parts of polyester polyol PES2 shown in the synthesis example, 25 parts of chain extender 1,4-butanediol and 17 parts of chain extender ethylene glycol in a 5 liter four-necked flask, and add 1191 parts of dimethylformamide to make uniform. Then, 255 parts of 4,4′-diphenylmethane diisocyanate was added and reacted at 80 ° C., and then 1588 parts of methyl ethyl ketone was added to obtain a polyurethane resin solution (U2) having a solid content of 30% and a viscosity of 550 poise.

[Example 3] U3
In a 5-liter four-necked flask, mix 919 parts of the polyester polyol PES3 shown in the synthesis example, 25 parts of the chain extender 1,4-butanediol and 17 parts of the chain extender ethylene glycol, and add 1216 parts of dimethylformamide to homogeneity. After that, 255 parts of 4,4′-diphenylmethane diisocyanate was added and reacted at 80 ° C., and then 1621 parts of methyl ethyl ketone was added to obtain a polyurethane resin solution (U3) having a solid content of 30% and a viscosity of 570 poise.

[Example 4] U4
Mix 910 parts of the polyester polyol PES4 shown in the synthesis example, 25 parts of the chain extender 1,4-butanediol and 17 parts of the chain extender ethylene glycol, and add 1207 parts of dimethylformamide. Then, 255 parts of 4,4′-diphenylmethane diisocyanate was added and reacted at 80 ° C., and then 1609 parts of methyl ethyl ketone was added to obtain a polyurethane resin solution (U4) having a solid content of 30% and a viscosity of 490 poise.

[Example 5] U5
Mix 900 parts of the polyester polyol PES5 shown in the synthesis example, 25 parts of the chain extender 1,4-butanediol and 17 parts of the chain extender ethylene glycol in a 5 liter four-necked flask, and add 1197 parts of dimethylformamide. Then, 255 parts of 4,4′-diphenylmethane diisocyanate was added and reacted at 80 ° C., and then 1596 parts of methyl ethyl ketone was added to obtain a polyurethane resin solution (U5) having a solid content of 30% and a viscosity of 550 poise.

[Example 6] U6
In a 5 liter four-necked flask, 897 parts of the polyester polyol PES6 shown in the synthesis example, 25 parts of the chain extender 1,4-butanediol and 17 parts of the chain extender ethylene glycol are mixed, and 1194 parts of dimethylformamide are added and uniform. Then, 255 parts of 4,4′-diphenylmethane diisocyanate was added and reacted at 80 ° C., followed by addition of 1592 parts of methyl ethyl ketone to obtain a polyurethane resin solution (U6) having a solid content of 30% and a viscosity of 570 poise.

[Comparative Example 1] U7
916 parts of the polyester polyol PES7 shown in the synthesis example, 25 parts of the chain extender 1,4-butanediol and 17 parts of the chain extender ethylene glycol are mixed in a 5 liter four-necked flask, and 1213 parts of dimethylformamide are added and uniform. After that, 255 parts of 4,4′-diphenylmethane diisocyanate was added and reacted at 80 ° C., and then 1617 parts of methyl ethyl ketone was added to obtain a polyurethane resin solution (U7) having a solid content of 30% and a viscosity of 510 poise.

[Comparative Example 2] U8
In a 5 liter four-necked flask, 914 parts of the polyester polyol PES8 shown in the synthesis example, 25 parts of a chain extender 1,4-butanediol and 17 parts of a chain extender ethylene glycol are mixed, and 1211 parts of dimethylformamide is added to be uniform. Then, 255 parts of 4,4′-diphenylmethane diisocyanate was added and reacted at 80 ° C., and then 1614 parts of methyl ethyl ketone was added to obtain a polyurethane resin solution (U8) having a solid content of 30% and a viscosity of 520 poise.

[Comparative Example 3] U9
916 parts of the polyester polyol PES9 shown in the synthesis example in a 5 liter four-necked flask, 25 parts of the chain extender 1,4-butanediol and 17 parts of the chain extender ethylene glycol are mixed, and 1213 parts of dimethylformamide are added and uniform. After that, 255 parts of 4,4′-diphenylmethane diisocyanate was added and reacted at 80 ° C., and then 1617 parts of methyl ethyl ketone was added to obtain a polyurethane resin solution (U9) having a solid content of 30% and a viscosity of 500 poise.

[Method for evaluating hydrolysis resistance]
The polyurethane resin solvent solutions obtained in Examples 1 to 6 and Comparative Examples 1 to 3 were coated on a release paper so as to have a thickness of 100 microns and dried at 70 ° C. for 2 minutes and further at 110 ° C. for 2 minutes to obtain a polyurethane film. The obtained film was cured for 2 weeks under wet heat conditions of 70 ° C. × 95%. Tensile strength and elongation were measured before and after curing according to JIS K7312. The value before curing was defined as 100 and expressed as a relative value after curing.

[Evaluation method of wear resistance]
Using the polyurethane resin solvent solutions obtained in Examples 1 to 6 and Comparative Examples 1 to 3, skin layer blending liquids were obtained according to the following skin layer blending. The obtained skin layer compounded liquid was applied on a release paper to 100 microns and dried at 90 ° C. for 2 minutes and further at 110 ° C. for 2 minutes. Next, an adhesive layer compounded solution obtained according to the following adhesive layer formulation was applied thereon to a thickness of 100 microns, immediately pasted with a raised cloth and dried at 120 ° C. for 3 minutes, and then aged at room temperature for 5 days. The release paper was peeled off to obtain a synthetic leather. This synthetic leather was designated as JIS No. L-1096, wear wheel H-22, load 500 g, applied to a taper wear test device (rotary abrasion tester manufactured by Toyo Seiki Seisakusho Co., Ltd.) at 1000 rotations, and the amount of wear was indicated by a numerical value in mg.

Skin layer combination ・ Polyurethane resin solution 100 parts ・ Dilack ・ Black ・ L color 15 parts (Dic Co., Ltd. colorant)
・ Dimethylformamide 30 parts

Adhesive layer formulation-Crisbon 4010 100 parts (polyurethane resin manufactured by DIC Corporation, solid content 50%)
・ Bernock D-750 10 parts (DIC Co., Ltd. organic polyisocyanate cross-linking agent, 75% active ingredient)
・ Chrisbon Accel HM 3 parts (Amine-based catalyst manufactured by DIC Corporation)
・ Toluene 15 parts

  Comparative Examples 1 and 2, which are polyurethane resins using a polyester polyol using adipic acid instead of sebacic acid, had poor wear resistance and hydrolysis resistance. Comparative Example 3 which is a polyurethane resin using a polyester polyol in which 30 mol% of sebacic acid was used as an acid component had poor hydrolysis resistance and insufficient wear resistance.

Claims (6)

In the polyurethane resin composition for synthetic leather containing the polyisocyanate (A), the polyol (B), and the chain extender (C),
A polyurethane resin composition for synthetic leather, wherein the polyol (B) contains a polyester polyol (B-1) using 60 to 100 mol% of sebacic acid in the dibasic acid component. The polyurethane resin composition for synthetic leather according to claim 1, wherein the glycol component constituting the polyester polyol (B-1) contains a side chain-containing diol. 3. The polyurethane resin composition for synthetic leather according to claim 1, wherein the glycol component constituting the polyester polyol (B-1) contains 20 mol% or more of a side chain-containing diol. . The side difference-containing diol is at least one selected from the group consisting of 1,2-propylene glycol, neopentyl glycol, 3-methylpentanediol and 2-methyl-1,3-propanediol. 3. The polyurethane composition for synthetic leather according to any one of 3 above. The polyurethane composition for synthetic leather according to any one of claims 1 to 4, wherein the chain extender (C) is an aliphatic short-chain diol having 2 to 18 carbon atoms. A synthetic leather comprising the polyurethane composition according to any one of claims 1 to 5.