JPS61254658A - Polyurethane emulsion - Google Patents

Abstract

PURPOSE:An emulsion providing a product having improved qualities, capable of finishing gelatinizing and drying processes in several minutes without requiring strict temperature control, comprising a specific hydrophobic polyurethane, a specific hydrophilic polyurethane, an organic solvent and water. CONSTITUTION:An water-in-oil type polyurethane emulsion comprising (A) a hydrophobic polyurethane obtained by reacting a hydrophobic polyol with an organic diisocyanate and a chain extender, (B) a hydrophilic polyurethane obtained by reacting a poly(oxyalkylene)glycol with an organic diisocyanate, wherein the glycol is a block copolymer of poly(oxyethylene)glycol and a poly(oxyalkylene)glycol except the poly(oxyethylene)glycol and the amount of a block consisting of the poly(oxyethylene)glycol is 25-50wt% based on the block copolymer, (C) an organic solvent, and (D) water.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is directed to polyurethane W10, which can provide polyurethane porous sheet materials with high productivity and excellent performance such as mechanical properties and water vapor permeability. Regarding emulsions.

(Prior Art) Many porous sheet materials made of polyurethane as natural leather substitutes and methods for producing them have been known, and can be roughly divided into wet methods and dry methods.

Wet methods generally use polyurethane organic solvents, while dry methods use polyurethane emulsions.

(Problem to be solved by the invention) Both methods have their advantages and disadvantages, and the dry method is superior in terms of productivity.

As the polyurethane emulsion used in such a dry method, Japanese Patent Publication No. 48-4380 and Japanese Patent Publication No. 8-874 Sho.
Publication No. 2, JP-A-51-41063, JP-A-54
-Polyurethane emulsions described in JP-A-66961 and JP-A-54-68498 are known. ・According to methods using these known polyurethane emulsions, porosity with excellent performance can be achieved. Sheet materials are provided, but in order to obtain products with excellent performance by these methods,
It is necessary to selectively evaporate the organic solvent and water used in the polyurethane emulsion used, and the gelation and drying steps require very strict temperature control and require a relatively long time, e.g. 30 minutes. Since it takes ~1 hour, there is a problem in that productivity is extremely low due to the gelation and drying steps, even though other steps can be made continuous.

Therefore, in order to improve productivity, it is necessary to eliminate the need for strict temperature control during the gelation and drying steps in the above-mentioned method, and to complete the gelation and drying steps within 10 minutes, preferably within a few minutes. There is a strong demand in the industry for polyurethane emulsions that can complete the process.

In response to the above-mentioned needs of the prior art, the present inventor has solved the complication of selective evaporation of organic solvent and water in the gelation and drying process in the conventional method, and has also solved the entire gelation and drying process. As a result of intensive research to obtain a polyurethane emulsion that can be completed in less than 10 minutes and still provide a product of excellent quality, we have used a specific hydrophilic polyurethane as a component of the polyurethane emulsion used in these methods. The present invention was completed based on the finding that when the above-mentioned method is used, the drawbacks of the prior art as described above can be solved and the above-mentioned demands of the industry can be fully met.

(Means for Solving Problems) That is, the present invention provides an oil-in-water polyurethane emulsion comprising a hydrophobic polyurethane (a), a hydrophilic polyurethane (b), an organic solvent (c) and water: (a) is a hydrophobic polyurethane obtained by reacting a hydrophobic polyol, an organic diisocyanate, and a chain extender, and the above hydrophilic polyurethane (b)
is a hydrophilic polyurethane obtained by reacting poly(oxyalkylene) glycol and an organic diisocyanate, and the poly(oxyalkylene) glycol is a hydrophilic polyurethane obtained by reacting poly(oxyalkylene) glycol with poly(oxyethylene) glycol and poly(oxyethylene) glycol other than poly(oxyethylene) glycol. This polyurethane emulsion is a block copolymer of poly(oxyethylene) glycol and is a hydrophilic polyurethane in which the blocks made of poly(oxyethylene) glycol account for 25 to 50% by weight in the block copolymer.

To explain the present invention in more detail, 1. The hydrophobic polyurethane (a) used in the present invention itself is a conceptually known material, and is obtained by reacting a hydrophobic polyol, an organic diisocyanate, and a chain extender. It is.

Hydrophobic polyols include, for example, polyethylene adipate, polyethylene propylene adipate, polyethylene butylene adipate, polydiethylene adipate, whose terminal group is a hydroxyl group and whose molecular weight is 300 to 4,000.
polybutylene adipate, polyethylene succinate,
polybutylene succinate, polyethylene sebacate,
Polybutylene sebacate, polytetramethylene ether glycol, poly-ε-caprolactone diol, polyhexamethylene adipate, carbonate polyol,
Examples include C3 or higher poly(oxyalkylene) glycols such as polypropylene glycol.

Examples of the organic diisocyanate include 4,4'-diphenylmethane diisocyanate (MDI), water-added MDI, and inphorone diisocyanate.

3-xylylene diisocyanate, 1,4-xylylene diisocyanate, 2,4-)lylene diisocyanate, 2,6-lylene diisocyanate, 1,5-naphthalene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, etc. Naturally, urethane polymers obtained by reacting these organic diisocyanates with low molecular weight polyols or polyamines to form terminal incyanates can also be used.

As chain extenders, ethylene glycol, propylene glycol, diethylene glycol, 1°4-butanediol, 1,6-hexanediol, ethylenediamine,
l, 2-propylene diamine, trimethylene diamine,
Examples include tetramethylene diamine, hexamethylene diamine, decamethylene diamine, inphorone diamine, m-xylylene diamine, hydrazine, water, and the like.

Hydrophobic polyurethane (a) obtained from materials such as those mentioned above
Any of these can be used in the present invention, but the most preferred are those obtained by synthesizing these hydrophobic polyurethanes (a) in a specific organic solvent and obtaining a dispersion or solution thereof.

For example, a dispersion or solution of the hydrophobic polyurethane (a) can be prepared by dispersing the hydrophobic polyurethane (a) in an organic solvent (c) which has limited mutual solubility with water and preferably has a boiling point of 120°C or less at normal pressure. It can be obtained by reacting the three components mentioned above in a medium. The reaction conditions, such as temperature and time, may be conventionally known conditions.

Preferred organic solvents (c) include methyl ethyl ketone, methyl-n-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, perchlorethylene, trichlorethylene, methyl cellosolve, butyl cellosolve, cellosolve acetate, etc. can also be used.

Those organic solvents that have no limit to their mutual solubility with water, or those that do not dissolve at all, should be mixed with other organic solvents and used as organic solvents with a limit in their mutual solubility with water. Of course, it can also be used as a mixed organic solvent. By preparing the hydrophobic polyurethane (a) in such an organic solvent (c), a dispersion or solution thereof can be obtained, but the solid content is the same. Or, it is convenient to adjust the amount to about 5 to 60% by weight by adding or removing other solvents.

The hydrophilic polyurethane (b) used in the present invention and which mainly characterizes the present invention is poly(oxyalkylene)
It is obtained by a conventionally known method from glycol and organic diisocyanate, and in the present invention, 25 to 50% by weight of the total amount of the poly(oxyalkylene) glycol used is derived from poly(oxyethylene) glycol. The main feature is that a block copolymer is used in which the other blocks are poly[oxyalkylene coglycol blocks other than poly(oxyethylene) glycol.

According to detailed research by the present inventors, it has been found that hydrophilic polyurethane (b) using such a specific block poly(oxyalkylene) glycomyl can be used in place of hydrophilic polyurethane in conventionally known polyurethane emulsions. By using this method, it is possible to achieve gelation and drying processes easily and in a short time, which were unachievable with conventionally known polyurethane emulsions, and to provide porous polyurethane sheet materials of excellent quality with excellent productivity. This is what I found out.

On the other hand, poly(oxyalkylene) glycols other than those mentioned above, such as poly(oxyethylene) blocks, are
A block copolymer with a content of less than 0% by weight or more than 50% by weight is used, or a block copolymer with an oxyethylene content of 20 to 5% by weight is used.
Although the reason is unknown, if a random copolymer is used even if the amount is 0i%,
In gelling and drying treatments at 0 to 150°C for 1 to 10 minutes, problems such as generation of giant pores in the porous layer or deterioration of the porous layer cannot be avoided.

The above-mentioned block poly(oxyalkylene) glycol itself used in the production of the hydrophilic polyurethane (b) is conventionally known and can be easily obtained from the market in various combinations and with various poly(oxyethylene) block contents. .

Blocked poly(oxyalkylene) glycols that are particularly useful in the present invention are those in which the hydrophilic blocks, ie, poly(oxyethylene) blocks, account for 25 to 50% by weight.

Other blocks, poly(oxyalkylene) glycols, are for example polyoxypropylene glycol, poly(oxyalkylene) glycol,
C3 to C8 poly(oxyalkylenes) such as oxytetramethylene) glycol, poly(oxyhexamethylene) glycol, poly(oxyheptamethylene) glycol, poly(oxyoctamethylene) glycol, poly(oxy1,2-butylene) glycol; ) Any poly(oxyalkylene) block such as a random or block copolymer of glycol or 03-C8 fullkylene oxide.

Block copolymers consisting of the above poly(oxyethylene) block (A) and other poly(oxyalkylene) blocks (B) are A-B type, A-B-A type, B-
Any type of block copolymer such as AB type or (AB)n type may be used.

Further, according to the inventor's detailed research, particularly preferred for the purpose of the present invention are poly(oxyethylene) blocks having an average molecular weight of about 200 to 3,000, and other poly(oxyalkylene) blocks having an average molecular weight of about 200 to 3,000. ) blocks are approximately 400 to 6,0
The block copolymer was found to have an average molecular weight of 0.00 and the block copolymer as a whole had an average molecular weight of about 800 to 10,000.

As the organic diisocyanate to be reacted with the above-mentioned block poly(oxyalkylene) glycol, any of the conventionally known organic diisocyanates or terminal incyanate urethane prepolymers as described above can be used.

Furthermore, any known method can be used to produce the hydrophilic polyurethane (b) from such materials.

The hydrophilic polyurethane (b) obtained in this way is
The molecular weight is preferably about 1.000 to 50°000, and varies depending on the average molecular weight of the organic diisocyanate used, but the poly(oxyethylene) block in the resulting hydrophilic polyurethane (b) is: It is preferable that the amount is about 20 to 45% by weight based on the entire hydrophilic polyurethane (b).

The polyurethane emulsion of the present invention comprises the above-mentioned hydrophobic polyurethane (a), preferably a dispersion or solution in the above-mentioned organic solvent, and the above-mentioned hydrophilic polyurethane (b) (or its solution) in a solid content. Hydrophobic polyurethane (by weight)
a)/Hydrophilic polyurethane (b)=80~99/20~
1, and the total solid content is adjusted to about 5 to 60% by weight, and the mixed dispersion or solution is mixed with a saturated amount or less of water, e.g., mixed dispersion, while vigorously stirring. Approximately 50 to 50 per 100 parts by weight of solids in liquid or solution
Obtained by adding 0 parts by weight of water.

The polyurethane emulsion of the present invention thus obtained (
d) is a milky white creamy fluid that remains stable even if left as is for several months.

Such a polyurethane emulsion (d) may contain various additives, such as a coloring agent and a crosslinking agent, as required.

Known additives such as stabilizers and fillers can be optionally added.

The base material to which the polyurethane emulsion of the present invention is applied is as follows:
For example, any base material such as various woven fabrics, knitted fabrics, non-woven fabrics, release paper, plastic films, metal plates, glass plates, etc. may be used.

The method for applying the polyurethane emulsion (d) to the substrate is, for example, a coating method or a dipping method.

Any known method such as a combination method of these may be used, and the impregnating and/or coating amount can be varied within a wide range depending on the purpose, such as about 5 to 2.000 g (blended solution/rrff).

When producing a porous sheet using the polyurethane emulsion of the present invention by a conventional method, the gelation and drying steps can be completed in a very short time and without the need for complicated treatments, and can be completed using conventional methods. In dry methods such as the one described above, this gelation and drying method is the rate-limiting step in the productivity of porous sheet materials; therefore, such short gelation and drying times are not suitable for conventional methods using polyurethane emulsions. This is a very advantageous effect.

That is, the impregnated and/or coated substrate does not require any coagulation process as described in JP-A-51-41063, and is only gelled and dried at about 60-150°C for about 1 to 10 minutes. The desired porous sheet material is obtained.

Such a short gelation and drying process is achieved because the hydrophobic polyurethane (a) used as a film forming agent in the present invention accounts for the majority of the total polyurethane,
It is stably dispersed and emulsified with water by a small amount of hydrophilic polyurethane (b), which is a surfactant, and when drying, it quickly and easily comes into contact with water due to the evaporation of the organic solvent (c), resulting in gelation. It is thought that.

(Action/Effect) The porous sheet material obtained by using the polyurethane emulsion of the present invention as described above has a very fine pore structure, has excellent various physical properties, and has excellent water vapor permeability. It is useful as a material for various synthetic leathers, clothing, shoes, waterproof fabrics, tents, wallpaper, flooring materials, filtration materials, filters for air conditioners, etc.

Next, the present invention will be specifically explained with reference to Examples. In addition,
Unless otherwise specified, all references to "%" or "%" are based on weight.

Examples 1 to 7 (Production of hydrophobic polyurethane (a) and hydrophilic polyurethane (b)) 1. Polytetramethylene glycol (average molecular weight approximately 1.
000. Add 1,000 parts of hydroxyl value 112), 93 parts of ethylene glycol and 625 parts of diphenylmethane diisocyanate to 1,500 parts of methyl ethyl ketone,
After reacting at 80° C. for 8 hours, 2.500 parts of methyl ethyl ketone was further added, and the mixture was cooled to room temperature with stirring to obtain a milky white polyurethane dispersion (1) with a solid content of 30%.

2.1.4-Butaneethylene 7dipate (average molecular weight approximately 1,000, hydroxyl value 112) 1,000 parts, 1.4-
144 parts of butanediol, 1.14 parts of methyl ethyl ketone
4 parts of diphenylmethane diisocyanate and 850 parts of diphenylmethane diisocyanate were reacted for 8 hours at 70"0, then 3.042 parts of methyl ethyl ketone was added to homogenize, and the mixture was cooled to room temperature with stirring to form a milky white polyurethane dispersion with a solid content of 30% (
2) was obtained.

3.1.1,000 parts of 6-hexamethylene adipate (average molecular weight approximately 2,000, hydroxyl value 56), 125 parts of 1,4-butanediol and 472 parts of diphenylmethane diisocyanate t Methyl ethyl ketone 1,20011
After reacting at 70"0 for 8 hours, 2.526 parts of methyl ethyl ketone was added to homogenize the mixture, and the mixture was cooled to room temperature with stirring to obtain a milky white polyurethane dispersion (3) with a solid content of 30%. .

4.1. After reacting 1,000 parts of 4-butane ethylene adipate (average molecular weight about 1,000, hydroxyl value 112) and 408 parts of isophorone diisocyanate at 100°C for 6 hours, 1.230 parts of methyl ethyl ketone, 1 part of toluene,
230 parts, n-butanol 1,230 parts and 148 parts of inphorondiamine were added, stirred and thoroughly homogenized,
A polyurethane solution (4) with a solid content of 30% was obtained.

5. Poly(oxypropylene) poly(oxyethylene)
Klicol [block copolymer of poly(oxypropylene)/poly(oxyethylene) = 70/30, average molecular weight approximately 5.300. Hydroxyl value 21) 1.0OOfi and 42 parts of diphenylmethane diisocyanate at 80°C.
After reacting for an hour, 1.042 parts of methyl ethyl ketone was added and stirred until uniform.
) was obtained.

6. Poly(oxytetramethylene) poly(oxyethylene) glycol [poly(oxytetramethylene)/poly(oxyethylene) = 60740f) block copolymer, average molecular weight approximately 3,100, hydroxyl value 36] 1.0
After reacting 00 parts of tolylene diisocyanate with 45 g of tolylene diisocyanate at 90°C for 4 hours, 1,045 parts of methyl ethyl ketone was added and stirred until uniform. Polyurethane solution (
6) was obtained.

7. Polyethylene glycol adipate glycol (average molecular weight approximately 690, hydroxyl value 162) 1009 and 76 parts of water-added diphenylmethane diisocyanate were heated at 110°C.
The mixture was reacted for 4 hours to obtain a urethane prepolymer having an N00% of 6.92.

Next, poly(oxytetramethylene) poly(oxypropylene) poly(oxyethylene) glycol [block copolymer of poly(oxytetramethylene)/poly(oxypropylene)/poly(oxyethylene) = 30/30/40, average molecular weight Approximately 7,000. Hydroxyl value 16)1
, and reacted at 110°C for 8 hours, then added 1.470 parts of methyl ethyl ketone and stirred until homogeneous to form a polyurethane solution with a solid content of 50% and a poly(oxyethylene) content of 35.2%. (7) was obtained.

Examples 8 to 13 (Production of polyurethane emulsion (d)) The products of Examples 1 to 7, organic solvent (c) and water were stirred in a homomixer, and the following polyurethane W10 of the present invention was prepared.
Emulsion (d) was prepared.

8. Polyurethane dispersion (1) 100 parts Polyurethane solution (5) 5 parts Methyl ethyl ketone
20 parts toluene
20 parts water
80 parts 9 Polyurethane dispersion (2)
100 parts polyurethane solution (5) 6
1 part dioxane 10 parts toluene 10 parts xylene
20 parts water
60 part 10, boli
10 Polyurethane dispersion (2) Loo part polyurethane solution (6)
3.5 parts methyl ethyl ketone
20 parts pheasant roll 20 parts water
75 parts 11, polyurethane 11 polyurethane dispersion (3) 100 parts polyurethane solution (6) 2, 5 parts tetrahydrofuran 20 parts xylene
20 parts water
80 parts 12, polyurethane
12 Polyurethane dispersion (3) 100 parts Polyurethane solution (7) 6 parts Methyl ethyl ketone 150 parts Methyl isobutyl ketone
20 parts water
70 part 13, poly
13 Polyurethane solution (4)
Loo part polyurethane solution (5)
5 parts calcium carbonate 10 parts toluene 30 parts methyl ethyl ketone 20 parts water
80 parts The properties of the above polyurethane emulsions (8) to (13) are shown in Table 1 below.

One self-list - J-j mantle - 111 Rainbow skin 2jN Yu Shusei 3 8 21, '000 (cps) 1
4.4(ri9 18.000 1
11t, 010 28.000
14.511 24.000 1
4.012 130 9.51
3 34.000
1? , 3 Remarks Stability: No change after 3 months or more Examples 14 to 20 The polyurethane emulsions (8) to (13) shown in Table 1 above were impregnated and/or applied to various base materials and gelled. and dried to obtain various porous sheet materials. The manufacturing conditions and results are shown in Tables 2 and 3 below.

Example 14 111 8 [''Release paper-m'' 200 (coating) LjLtjl 85℃ 3 minutes Example 15 111 8 L'' Nylon tack.
rr1″ 600 (coating) 1u” 90
℃4 minutes Example 16 Milk JL liquid 9 Base material Cotton Cloth
rr1'' 400 (coating) rLjL!L!!E90°C 2 minutes Example 17 1 member J 10 ['' T/R raised fabric rn'
800 (coating) 1 u” 90°C for 5 minutes Example 18! gJ! u! 11 Base material Cotton
Cloth-m" 300 (coating) 1u" 90℃ 2 minutes Example 19 1 member J12LJt Nonwoven fabric rf 1000 (coating) IIJJLn 100℃ 5 minutes Example 20 1 member J13LJt Tetron taffeta rrI'' t
oo c application) uu'' 95℃ 2 minutes 3 sea fruit'' 1 example 1! II Danri
N14 White 0.4135 74 95
80 Uniform dense 15 // 0.5
17 20? 7240 //18
// 0.481 121
8930 tt17! I
O,5242898850//18/l
O,53893[1120//19
tt --8890//20
// 0.885 87 [135
0/1 Note ■... Apparent specific gravity (g/crn') ■... Thickness IL) ■... Moisture permeability (g/m''-24h) (JIS ZO2
0BB) ■ Internal pore structure As described above, according to the present invention, a porous sheet material with excellent physical properties can be provided by gelation and drying treatment in an extremely short time.

Patent applicant: Dainichiseika Kagyo Co., Ltd. (1 other person)

Claims (1)

[Claims] (1) In a water-in-oil polyurethane emulsion (d) consisting of a hydrophobic polyurethane (a), a hydrophilic polyurethane (b), an organic solvent (c) and water; The above hydrophilic polyurethane (b) is a hydrophilic polyurethane obtained by reacting a poly(oxyalkylene) glycol with an organic diisocyanate. and
The poly(oxyalkylene) glycol is a block copolymer of poly(oxyethylene) glycol and a poly(oxyalkylene) glycol other than poly(oxyethylene) glycol, and the block consisting of the poly(oxyethylene) glycol is the block copolymer. A polyurethane W/O emulsion characterized in that hydrophilic polyurethane accounts for 25 to 50% by weight.