JPS63315676A - Polyurethane synthetic leather - Google Patents

Abstract

PURPOSE:To obtain a polyurethane synthetic leather having high performance at a low cost, by using a specific polyol as total or a part of polyol component of a polyurethane polymer constituting a synthetic leather. CONSTITUTION:A polyurethane polymer is produced by polymerizing (A) a polyol component containing polymethylvalerolactone polyol having a molecular weight of 300-5,000 accounting for 5-100wt.% of total polyols with (B) known 4,4'-diphenylmethane diisocyanate and the obtained polymer is used as a raw material for a synthetic leather having a polyurethane polymer layer on a substrate. The synthetic leather produced by the use of said polymer has excellent hydrolysis resistance and light-deterioration resistance compared with conventional adipate-type polyurethane synthetic leather. The leather can be produced stably for a long period at a low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to polyurethane-based synthetic leather, and more particularly to a novel polyurethane-based synthetic leather that is inexpensive and has high performance.

(Conventional technology and its problems) Conventionally, as polyurethane-based synthetic leather, synthetic leather mainly using adipate-based polyurethane resin has been widely used. According to the report, it was unsuitable for long-term use because the surface film cracked and broke and became unusable after about 3 to 5 years due to deterioration due to mold growth, deterioration due to sweat, deterioration due to hydrolysis, etc. .

To solve these drawbacks, polyurethane resins containing polycarbonate polyol alone or in combination with other polyester polyols, such as general adipate polyester polyol, polytetramethylene glycol, polycaprolactone polyol, etc., are used as the polyol component. Synthetic leather was developed.

These polyurethane-based synthetic leathers have sufficiently solved the drawbacks of the conventional adipate-based polyurethane-based synthetic leathers, but these polycarbonate-based polyurethane resins are 2 times cheaper in the market price than general polyurethane resins. It has the disadvantage that it is 3 times as expensive and cannot be used industrially as a material for synthetic leather.

Therefore, there is a need for polyurethane-based synthetic leather that has the same excellent durability as polycarbonate-polyurethane-based synthetic leather while being priced at the same level as adipate-based polyurethane-based synthetic leather.

(Means for Solving the Problems) As a result of intensive research in response to the demands of the prior art as described above, the present inventor has discovered that by adopting a specific polyurethane resin, an inexpensive and high-performance polyurethane resin can be produced. The present invention was completed by discovering that synthetic leather can be obtained.

That is, the present invention provides a polyurethane synthetic leather formed by forming a polyurethane resin layer on a base material, characterized in that all or part of the polyol component of the polyurethane resin is polymethylvalerolactone polyol. Polyurethane synthetic leather.

(Function) By employing a specific polyol as the polyol component of the polyurethane resin constituting the synthetic leather, an inexpensive and high-performance polyurethane synthetic leather can be provided.
4 (Preferred Embodiments) Next, the present invention will be described in more detail by citing preferred embodiments of the present invention.

The polyurethane resin used in the present invention and which mainly characterizes the present invention is characterized in that polymethylvalerolactone polyol is used as all or a part of its polyol component.

Polymethylvalerolactone polyol is a polyester polyol obtained by ring-opening polymerization of methylvalerolactone of the following formula using a polyhydric alcohol such as ethylene glycol as an initiator, and polyester polyols with various molecular weights can be synthesized. However, in the present invention, a molecular weight of, for example, about 300 to 5,000 gives preferable results.

The amount of these polymethylvalerolactone polyols used may be such that the entire amount of the polyol used in the synthesis of the polyurethane resin may be the above-mentioned polymethylvalerolactone polyol, or it may be used in combination with other known polyols,
When used together, the proportion of the polymethylvalerolactone polyol in the total polyol is preferably about 5% by weight or more. If the amount used is less than 5% by weight, satisfactory results in terms of cost and performance cannot be obtained, which is not preferable.

As the polyol that may be used in combination, any of the conventionally known polyols for polyurethane can be used.
0 to 4,000 polyethylene adipate, polyethylene propylene adipate, polyethylene butylene adipate, polydiethylene adipate, polybutylene adipate, polyethylene succinate, polybutylene succinate, polyethylene sebacate, polybutylene sebacate, polycarbonate polyol, poly Examples include tetramethylene ether glycol, poly-ε-caprolactone diol, polyhexamethylene adipate, polypropylene glycol, and the above polyols containing an appropriate amount of polyoxyethylene chains.

As the polyisocyanate, any conventionally known polyisocyanate can be used; for example, 4,4'-diphenylmethane diisocyanate (MD) is preferred.
I), water-added MDI.

Isophorone diisocyanate, 1.3-xylylene diisocyanate, 1.4-xylylene diisocyanate, 2.4-tolylene diisocyanate, 2.6-tolylene diisocyanate, 1.5-naphthalene diisocyanate, m-phenylene diisocyanate, p-phenylene Naturally, diisocyanates and the like, or urethane prepolymers obtained by reacting these organic polyisocyanates with low molecular weight polyols or polyamines to form terminal isocyanates, can also be used.

As the chain extender, any conventionally known chain extender can be used; for example, preferred ones include ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, 1,6-hexanediol, ethylenediamine, 1. Examples include 2-propylene diamine, trimethylene diamine, tetramethylene diamine, hexamethylene diamine, decamethylene diamine, isophorone diamine, m-xylylene diamine, hydrazine, and water.

The above-mentioned polymethylvalerolactone segment dowel polyurethane resin can be easily obtained from the above-mentioned raw materials by a conventionally known production method using a catalyst if necessary. These polyurethane resins may be prepared without a solvent or in an organic solvent. All reaction conditions etc. may be in accordance with conventional techniques.

Preferred organic solvents include methyl ethyl ketone, methyl-〇-propyl ketone, methyl isobutyl ketone, diethyl ketone, methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate, butyl acetate, and acetone. , cyclohexane, tetrahydrofuran, dioxane, methanol, ethanol, isopropyl alcohol, butanol, toluene, xylene, dimethylformamide, dimethyl sulfoxide, perchloroethylene, trichlorethylene, methyl cellosolve, butyl cellosolve, cellosolve acetate, etc. can also be used.

The polyurethane resin obtained as described above has a weight of about 2
It has a molecular weight of about 10,000 to 500,000, and can be provided at a price not much different from conventional adipate polyurethane resins.
At the same time, it has excellent physical properties that are close to or comparable to conventional polycarbonate-based polyurethane-based resins (see Examples below).

The synthetic leather of the present invention is characterized by using the above-mentioned polyurethane system, and its structure and manufacturing method are not particularly limited as long as they can be in accordance with any conventionally known structure and manufacturing method.

Furthermore, the "synthetic leather" referred to in the present invention refers to a coating method in which a film made of the polyurethane resin described above is applied to the surface of a woven fabric, non-woven fabric, or knitted fabric (which may be brushed or piled) as a base material. It includes both so-called leather-type leather, which is formed by bonding methods, transfer methods, etc., and so-called synthetic leather, which has a porous layer, skin layer, surface treatment layer, etc. formed in or on the base material. .

(Effects) The polyurethane-based synthetic leather of the present invention obtained as described above can be provided at a price not much different from that of conventional adipate-based polyurethane-based synthetic leather, and at the same time is close to or comparable to conventional polycarbonate-based polyurethane-based synthetic leather. (See Examples below).

Therefore, the polyurethane synthetic leather of the present invention can be used in most of the applications for which polyurethane synthetic leather has conventionally been used, such as luggage such as travel bags and school bags, bags such as handbags, handbags, and accessory cases, shoes, and footwear. , clothing such as camera cases, radio cases, coats, jumpers, etc.
It is very useful as a material for many purposes such as interior products such as upholstery and cushions, book cloths, albums, and packing materials.

Next, the present invention will be explained in more detail with reference to Examples. In the text, parts or percentages are based on weight unless otherwise specified.

Example 1 Polyester polyol (PBA) with an average molecular weight of 2,000 synthesized from 1,4-butanediol and adipic acid
) and polymethylvalerolactone polyol (PMVl, ) having an average molecular weight i2,000 were used as polyol components in the following weight proportions.

ABCD E PMVL 100 75 50 25
0PBA 0 25 5
0 75 100 The above polyol components, diphenylmethane diisocyanate and 1,4-butanediol are polymerized in dimethylformamide by a known method, and the concentration is adjusted to give a non-volatile content of 30% and a viscosity of 500 to 900 voids (25°C). A dimethylformamide solution of a seed polyurethane resin was obtained. These polyurethane resins are used as a one-component type.

Example 2 A polyester polyol (P
BE8) and polymethylvalerolactone polyol (PMVL) having an average molecular weight of 2.000 were used as polyol components in the following weight proportions.

GH PBE8 100 50
0PMVL O50100 The above polyol component, tolylene diisocyanate and 1
, 4-butanediol was polymerized in ethyl acetate/toluene (weight ratio 1:1) by a known method, and the concentration was adjusted to give a nonvolatile content of 50% and a viscosity of 1000 to 1500 poise (2
A solution of five types of polyurethane resins in ethyl acetate/toluene (weight ratio 1:1) was obtained. These polyurethane resins are used as a two-component type.

Example 3 A polycarbonate polyester polyol (1) with an average molecular weight of 2,000 and a polymethylvalerolactone polyol (J) with an average molecular weight of 12,000 were used as polyol components.

The above-mentioned polyol component and aliphatic diisocyanate were polymerized in isopropyl alcohol/toluene (1:1) by a known method, and the concentration was adjusted to give two types of polymers with a non-volatile content of 25% and a viscosity of 150 to 200 poise (25°C). A solution of polyurethane resin in isopropyl alcohol/toluene (weight ratio 1:1) was obtained. These polyurethane resins are used as a one-component type.

A hydrolyzability test was conducted to examine the properties of each of the 10 types (A to J) of polyurethane resins obtained in the 100% polyurethane resin composition.

Among the polyurethane resins tested, -molded ones had a film of 40 to 50 μm after drying each solution.
Coat to a thickness of m and heat at 70°C for 5 minutes and 12
After drying at 0° C. for 10 minutes, the film was left at room temperature for one day to prepare a test film. On the other hand, for the two-part type, each solution contains 10
The film thickness obtained by adding 10 parts each of a crosslinking agent (Rethermin 110, manufactured by Dainichiseika Chemical Industry Co., Ltd.) and a crosslinking accelerator (Rethermin UD-102, manufactured by Dainichiseika Chemical Industry Co., Ltd.) to 0 parts, The film was coated on release paper to a thickness of 40 to 50 μm, dried at 70°C for 5 minutes and at 120"C for 10 minutes, and then left in an aging room at 60°C for 2 days to allow sufficient crosslinking reaction. A test was conducted.

For the hydrolysis test, each sample film was heated at 70℃95%.
The film was placed in an R11 testing machine and taken out every two weeks to test the strength and elongation of the film to examine its durability. 1st below
The results in the table were obtained.

(Left below) 0 2 4 6 8 10M
42 34 211A T 4
70 380 2]OE 430 520
400M 42 42 40
21B T 480 430 390
130E 440 450 480
120M 43 42 42 3
2 19CT 460 470 420
340 120E 450 440
510 560 340M 42 4
3 42 42 40 38D
T 4B0 490 480 460
440 390E 1160 460 4
70 490 520 580M 42
42 44 44 43 43
E T 500 510 500 4
90 490 480E 530 530
530 540 550 550M
28 19 8F T 320
200 62E 460 560
260M 27 27 27 2
6 18G T 310 320
300 280 170M 25 2
5 26 25 27 26HT
290 300 300 310 300
280E 4fi0 460 470
470 475 490M 93
93 93 93 92 92I
T 560 570 575 570
560 570E 380 380
:]70 :185 390 390M
89 89 90 90 90
88J T 460 470 47
0 480 470 470E 420
430 430 430 430 450 In Table 1 above, M, T and E have the following meanings.

M: 100% modulus (kg/crn") T: Breaking strength (kg/crn") E: Breaking elongation (%) In addition, if there is no numerical value in the table, the film disappears and the physical properties change. Indicates that measurement is not possible.

As described above, the polyurethane resin of the present invention exhibits significantly superior physical properties compared to conventional adipate-type polyurethane resins (A and F), and those using polymethylvalerolactone polyol alone (E, H, and J) Polyurethane resin using polycarbonate polyol (1)
It exhibits physical properties comparable to those of .

Example 4 Next, a method for producing synthetic leather using the polyurethane resin obtained above will be described.

0-Film: 1) Using the polyurethane resin described in 1 above, a composition for a skin film for synthetic leather was prepared with the following composition.

Resin solution (A, C or E) 100 parts Seiryoku Seven ALT-5093 White (manufactured by Dainichiseika Chemical Industry Co., Ltd.) 20 parts Methyl ethyl ketone 45 parts Resin solution (
J) 100 copies Seiki Seven DNT
-7093 White (manufactured by Dainichiseika Chemical Industry Co., Ltd.) 20 parts Dimethylformamide 20 parts J-≦
Resin solution (A, C or E) 100 parts Seiryoku Seven B5-1001 White 5 parts Shizamin (:
5 parts of UT-1900, 3 parts of Zamine CUT-30, 80 parts of dimethylformamide = 1
Knee resin solution (F, G or H) 100 parts Reshin UD 10 parts Reshin UD-
10210 parts Dimethylformamide 20 parts Methyl ethyl ketone 5 parts -=- Resin solution (I or J) 100 parts Isopropyl alcohol 50 parts Toluene
50 parts Seiki Seven DNT-709
3 White 30 parts 1 person 1 hole 5 Ω The above composition was coated on a tetron-rayon (T/R) raised fabric at a rate of about 1,000 g/rn"・wet, and the composition was coated in water containing 5% dimethylformamide. The resin was immersed in water for 15 minutes to completely precipitate and solidify the resin.Next, it was immersed in warm water at 60°C for 1 hour to extract dimethylformamide, and dried in a dryer at 100°C for 20 minutes to form microcells. A wet porous layer was formed.

120 g/rn"・w of the above-mentioned acid-containing JU-drinking composition for the epidermis layer was placed on release paper.
The film was coated at a ratio of 100° C. et and dried under conditions of 80° C. for 1 minute and 120° C. for 2 minutes to prepare a skin film. Next, apply 150 g/rn" of the adhesive layer composition on the film.
・Coat in a wet ratio and laminate Tetron/rayon brushed fabric with a clearance of 60% [release paper thickness + brushed fabric thickness +
Laminated using a laminating machine with an adhesive layer thickness of 150 g/rn'・stomach et)
Dry for 1 minute, leave in a 60℃ aging room for 2 days,
After the adhesive layer had completed the crosslinking reaction, it was returned to room temperature and the release paper was peeled off to obtain dry synthetic leather.

In addition, on the other hand, the adhesive composition was applied on the skin film for 80 minutes.
g/rn”-wet, dried at 80°C for 1 minute, laminated the above wet porous layer through a hot roll at 140°C, and then subjected to the same aging process as dry synthetic leather to create wet synthetic leather. did.

In addition, some of the dry and wet synthetic leathers described above were treated twice with a surface treatment agent using a 120-mesh gravure roll.

The synthetic leathers prepared above have the combinations shown in Table 2 below.

γ 27 (Dry synthetic leather) Germany, K face, shoulder, K skin, degree A drug notification I
A F2
A
G3 A
H4CF 5 CG6
CH 7E F 8 E G9
E
Hlo 1 E
HII J
E H12J
F13J
G14 J
H (Wet Synthetic Leather) Germany, Skin Layer Reciprocal Notification Ship Material Notification 15
A F A16
A G A17
A HA 18 CG C10CHH 20E G H21E
HH 22J HE For the above various synthetic leathers, the adhesive strength retention rate (%) in the hydrolysis test and the i, o in the Scotto type rubbing resistance tester.
Tested 0 times under the condition of 1 kg load, inspected for cracks on the surface or peeling of the surface film, etc. Also, regarding deterioration of light resistance, 1 part was treated with a sunshine fade meter to check for color change or cracks. Judgment was made based on the presence or absence of occurrence. These results are shown in Table 'i3.

3-F (Hydrolysis test) Once, once, one dish, one by one λ Hill Dan Dan Punishment 2
80 65 35” --395
9560” -- 46030-”2 − − 695958570” 76535*2- − 8 85 80 70 60”l
-9 95 95! 1
5 90 9012 65
35-”--14, 959595
9595 1535" --- 168530" --- 178530" --- 1890756025" - 1! ] 95 95 95
90 90'+20 95 9
5 95 80 30” Note) *1: Skin layer deterioration *2; Adhesive layer destruction (marked below) (light resistance deterioration test) 1 × 9 △ × 10 0 0 △ △II
OO△ △ 12 0 o o”+3
0 0 0 0”15
× 20 △ × 21 △ × Note) ○: No problem at all.

△: Slightly discolored.

×: Discolored parts.

*3: There was no discoloration, but the adhesive strength decreased to 50% or less.

As described above, the polyurethane-based synthetic leather of the present invention exhibits properties significantly superior to conventional adipate-based polyurethane-based synthetic leathers in all cases.

Patent applicant: Dainichiseika Kagyo Co., Ltd. IJ-'1 Agent: Patent attorney Yoshi 1) Katsuhiro! -i-・ko′・
: Throat 7

Claims (3)

[Claims] (1) A polyurethane-based synthetic leather formed by forming a polyurethane-based resin layer on a base material, characterized in that all or part of the polyol component of the polyurethane-based resin is polymethylvalerolactone polyol. leather. (2) Claim No. 1 in which the polymethylvalerolactone polyol accounts for 5 to 100% by weight of the total polyol (
The polyurethane synthetic leather described in item 1). (3) The polyurethane synthetic leather according to claim (1), wherein the polymethylvalerolactone polyol has a molecular weight of 300 to 5,000.