JPH083876A - Production of coated fabric - Google Patents

Abstract

PURPOSE:To provide a coated fabric having waterproofness and moisture permeability and excellent in retaining water resistance even after repeated washing. CONSTITUTION:This method for producing a coated fabric excellent in retaining water resistance is to coat a specific polyurethane resin solution of a water miscible organic solvent on at least one side of a fiber substrate, immerse into water to extract the organic solvent solution and dry the resulting product. Here, the polyurethane resin comprises a polyfunctional monomer having two active hydrogens in a molecule, a polyfunctional monomer having three active hydrogens in a molecule and an organic diisocyanate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a coated cloth, and more specifically, it has a waterproof property, a moisture permeable property, a soft texture, and excellent water retention after several repeated washings. The present invention relates to a method for producing a coated fabric having durability.

[0002]

2. Description of the Related Art Up to now, various kinds of waterproof and moisture-permeable coated cloth have been known, and a typical one is a cloth coated with a microporous film made of polyurethane resin. As a manufacturing method thereof, there is a so-called wet coagulation method in which a water-miscible solvent solution of a polyurethane resin is applied to a fiber base material and then immersed in a water bath to form a microporous film made of the polyurethane resin (special feature: Kosho 60-4
7955).

According to this method, JIS L-1079
The water permeability of the coated fabric having a water pressure resistance of 1500 to 3000 mm according to JIS Z-0208 is 7800 to 5000 g /
m ² · 24 hrs, water pressure resistance is 6500 to 7500
mm coated fabric has a moisture vapor transmission rate of 5000
Approximately 3800 g / m ² · 24 hrs is obtained.

Further, a coated cloth using a fluorine-modified polyurethane resin or a fluorine-modified polyamino acid resin (JP-A-3-27184) or a coating cloth using a fluorine-modified polyurethane resin and a fluororesin solution (JP-A-3-8874). However, these coated fabrics have a water pressure resistance of about 3000 mm and a moisture permeability of 9000 to 10000 g / m ² · 24 hr.
It is about s. Further, it is known that a coated cloth obtained by wet coagulation using a polyamino acid resin / urethane resin solution has a water pressure resistance of about 3000 mm and a water vapor transmission rate of about 10,000 g / m ² · 24 hrs.

In addition, a method for producing a coated cloth using a mixed solution of a fluorine-modified polyurethane resin and a cellulose derivative has been proposed (Japanese Patent Laid-Open No. 6-2).
No. 278), the water pressure resistance of this method is 700.
The performance is about 0 mm and a water vapor transmission rate of about 8000 g / m ² · 24 hrs.

[0006]

However, any of the conventional coating cloths made of a resin solution containing the above-mentioned polyurethane resin as one component has the following problems in practical use. That is,

(1) For example, for a coated cloth having a water pressure resistance of 3000 mm before washing, JIS L
According to the automatic washing operation of -1096 6.23.1 (method A), the water pressure resistance after repeating 10 times of washing was measured and found to be 600 to 1000 mm, and the water resistance retention rate (%) was Reduce to about 20-30%. [Note that the water resistance retention rate (%) is calculated by (water pressure after washing / water pressure before washing) × 100].

(2) When a resin solution is applied to a fiber base material to obtain a coated fabric, if a base cloth having a low fiber density is used, the resin solution passes through the base cloth, and a so-called back leakage phenomenon occurs. In addition, when a base cloth having a feeling of unevenness is used, the coating amount is greatly different between the convex portion and the concave portion, which causes variations in various physical properties.

(3) In order to avoid the above-mentioned problem (2) when a coated cloth is obtained by using a base cloth having a low fiber density or a base cloth having unevenness, an acrylic rubber is applied before the resin solution is applied. It is necessary to thinly undercoat a base paint with a base paint or a polyurethane paint with high viscosity and high solid content, but the number of steps is increased and the texture of the resulting coated fabric is not preferable. And so on.

In order to solve the above-mentioned problems in the conventional coated cloth, the present invention has excellent water pressure resistance and water vapor transmission rate and a high water resistance retention rate by using a material and means completely different from the conventional one. An object of the present invention is to provide a coated fabric having excellent washing durability.

[0011]

That is, the present invention is intended to improve the so-called water resistance retention rate such as washing durability of a coated fabric obtained by a wet coagulation method of a polyurethane resin solution, and it is active in the molecule. A water-miscible organic solvent solution of a polyurethane resin composed of a polyfunctional monomer having two hydrogen atoms and a polyfunctional monomer having three or more active hydrogen atoms in the molecule, and an organic diisocyanate is applied to at least one side of a fiber substrate. It is a method for producing a coated cloth, which comprises: applying a water-miscible organic solvent by dipping in water, extracting the water-miscible organic solvent, and then drying. The polymer is characterized by using 0.1 to 3.0 mol% of a polyfunctional monomer having two active hydrogens in the molecule.

[0012]

The present invention relates to a monomer to be reacted with an organic diisocyanate in the production of a polyurethane resin solution which is applied to a fiber base material to obtain a coated cloth.
By using a polyfunctional monomer having two active hydrogens in the molecule and a polyfunctional monomer having three or more active hydrogens in the molecule together, a branched structure of the polyurethane resin is formed and Since a resin solution having a Newtonian viscosity is obtained, the coated cloth coated with this resin solution should have good water pressure resistance, moisture permeability, and high wash durability with high water resistance retention rate. Can be done.

In obtaining a coated fabric, a conventional Newton viscosity polyurethane resin solution is used as a base material for the resin at the coating head of a coating machine immediately after the resin solution is applied to the fiber base material and before it is immersed in water. Due to the pressure applied to the cloth, the capillary phenomenon of the fibers that make up the base cloth, and the gravity received from the coating surface perpendicularly to the base cloth surface,
The polyurethane resin solution passes through the base cloth, and a so-called back leakage phenomenon occurs.

However, in the case of using a polyurethane resin solution having a high cross-linking density and a non-Newtonian viscosity, which uses a specific elemental component as in the present invention, the viscosity does not pass through the base cloth, and therefore the back cloth is not passed through. There is no risk of leakage.

Further, the above-mentioned JISL-1096 6.2 of the coated cloth obtained by applying the resin solution and drying it.
Even in the water pressure resistance measurement after washing 10 times in accordance with 3.1 (Method A), the water resistance retention rate of the conventional polyurethane resin solution is only about 20 to 30%, whereas this invention In the coated fabric produced by
A high water resistance retention of 70 to 80% can be obtained.

This is because the polyurethane resin solution of the present invention has a non-Newtonian viscosity by using a polyfunctional monomer having three or more active hydrogens as a primary component as described above. This is because the cross-linking density is increased due to its own branching, and the degree of entanglement between the molecules and the base fabric fiber in the microscopic sense is superior to that of the conventional polyurethane resin solution.

In general, the viscosity of a polymer solution has the formula S = μ
D ⁿ (S: Shear stress, μ: Non-Newtonian viscosity coefficient, D:
Shear velocity, n: non-Newtonian viscosity index, 1>n> 0) is said to indicate non-Newtonian viscosity, but this is complicated by the effects of the Weisenberg effect, thixotropy, viscoelasticity, etc. And, it is difficult. In the present invention, in order to quantify the non-Newtonian viscosity, the thixotropic index (Thixotrop) is used.
The value measured by ic Index (hereinafter referred to as TI value) was adopted.

This measurement is carried out by measuring the viscosity by changing the number of revolutions using a rotational viscometer and calculating the ratio of the two. In the present invention, the BH type viscometer (manufactured by Tokyo Keiki Co., Ltd.) is used. Under a constant liquid temperature (30 ° C.), No. The viscosities at rotation speeds 2 and 20 were measured with a rotor of No. 7, and the ratio of the two was taken as the TI value.

As a result of this measurement, the TI value of the polyurethane resin solution of the present invention having a non-Newtonian viscosity is 1.1.
It was found to be in the range 0 to 2.00, preferably 1.15 to 1.50. This is because when the TI value is larger than 2.00, the liquid stability, liquid viscosity, and solubility in the solvent are poor, and it is difficult to obtain a uniform resin solution. Since the non-Newtonian viscosity required by the invention has not been obtained, it is difficult to obtain a coated fabric having the above-mentioned performance.

In the present invention, a main constituent component for obtaining a polyurethane resin solution having a TI value of 1.10 to 2.00 showing a non-Newtonian viscosity is as a monomer to be reacted with an organic diisocyanate, a molecule As a polyfunctional monomer having two active hydrogens therein, a polyalkylene ether glycol having an average molecular weight of 400 to 4000, a polyester polyol having a hydroxyl group at the terminal, a poly ε-caprolactone polyol, a polycarbonate diol, etc., alone or in a mixture. In addition, a polyfunctional monomer having three or more active hydrogens in the molecule is used, and in the course of the reaction, a chain extension is carried out with a compound having two active hydrogens, if necessary. A polyurethane resin solution exhibiting Newtonian viscosity can be obtained.

As the polyalkylene ether glycol, there are polytetramethylene ether glycol, polypropylene glycol, polyethylene glycol, glycerin propylene oxide adduct, polyether polyol having ethylene oxide added to the terminal, vinyl monomer grafted polyether polyol, etc., Examples of the polyester polyol include alkylene glycols such as ethylene glycol, butylene glycol, hexylene glycol, diethylene glycol, dipropylene glycol, neopentyl glycol and succinic acid, glutaric acid, adipic acid, sebacic acid, maleic acid, fumaric acid, phthalic acid. Those obtained by reacting an acid or a carboxylic acid such as trimellitic acid so that the terminal becomes a hydroxyl group are preferable.

As the polyfunctional monomer having three or more active hydrogens in the molecule, polyhydric alcohols such as glycerin, petriol, trimethylolpropane, pentaerythritol, and triethanolamine, iminobispropylamine, and trihydrylamine. A monomer having three or more active hydrogens capable of reacting with an organic diisocyanate in the coexistence of a polyvalent amine such as ethylenetetramine, an alcohol such as diethanolamine and aminoethylethanolamine, and an amine can be used, and a polyalkylene ether glycol, a polyester It is also possible to use one in which a part of the polyol composition is branched and has 3 or more active hydrogens capable of reacting with the organic diisocyanate. Further, these may be used alone or in combination.

As the organic diisocyanate, 2,4-
And 2,6-toluylene diisocyanate, 4,4'-
Aromatic diisocyanates such as diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, 1,6-hexamethylene diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 3-
There are aliphatic diisocyanates such as isocyanate methyl-3,5,5'-trimethylcyclohexyl diisocyanate and 2,6-diisocyanate methyl caproate, which may be used alone or in combination.

The polyurethane resin exhibiting non-Newtonian viscosity in the present invention is preferably blended by using the above-mentioned elementary components so that isocyanate groups do not remain at the ends, and the reacted average molecular weight is in the range of 30,000 to 120,000. In the above, the amount of the monomer having 3 or more active hydrogens in the molecule is preferably 0.1 to 3.0 mol% of the monomer having 2 active hydrogens.

This is because when the amount of the monomer having 3 or more active hydrogens is more than 3.0 mol% with respect to the monomer having 2 active hydrogens, the liquid stability and liquidity of the obtained resin solution are improved. viscosity,
When the amount is less than 1.0 mol%, it is difficult to obtain a uniform resin solution due to a problem in solubility in a solvent. It is difficult to obtain a viscous resin solution.

In the reaction of the above polyfunctional monomer and organic diisocyanate, hydrazine, ethylenediamine, tetramethylenediamine, water, piperazine, isophoronediamine, ethylene glycol, butylene glycol, hexylene glycol, diethylene glycol may be used, if necessary. , Dipropylene glycol, neopentyl glycol and the like can be used alone or in combination as a chain extender.

As a water-miscible organic solvent used in the reaction of the above-mentioned monomer and organic diisocyanate, dimethylformamide (DMF) is typically used. In addition to this, dimethylacetamide and N-methylpyrrolidone are used. , Tetrahydrofuran, dioxane and the like can be used alone or in the form of a mixed solvent.

In the production of the polyurethane resin of the present invention, in order to further improve water pressure resistance and water vapor transmission rate, a cellulose derivative may be added if necessary. Examples of such a cellulose derivative include cellulose acetate, Cellulose esters such as cellulose acetate butyrate and cellulose acetate propionate, and cellulose ethers may be used alone or in combination.

In addition, as an additive, a polyfunctional polyisocyanate (for example, trade name Coronate EH, Coronate HL, manufactured by Nippon Polyurethane Industry Co., Ltd.) can be used in order to improve the adhesion to the coating substrate.
Further, it is effective to add a nonionic surfactant as a speed adjusting agent for solvent removal in wet coagulation.

The polyurethane resin solution having a non-Newtonian viscosity obtained by the present invention can be applied to a fiber substrate by an ordinary coating method, but the coating film thickness is 10 to 3
00 μm is preferable.

The water temperature when the fibrous base material having the above-mentioned polyurethane resin film formed thereon is immersed in water is 0 to 30 ° C.
Is preferable, and at 30 ° C. or higher, the pores of the resin coating become large and the water pressure resistance decreases. Further, the immersion time is required to be 30 seconds or more. If it is less than 30 seconds, the solidification of the resin is insufficient, which is not preferable. In addition, in order to completely remove the remaining organic solvent, you may wash with hot water at 30 to 80 ° C. for 3 to 10 minutes. Further, water resistance can be improved by further adding a water-repellent agent to the coated cloth obtained by washing with hot water and then drying. As the water repellent, there are various types such as paraffin type, silicon type, fluorine type and the like, which may be appropriately selected according to the application, and the application may be performed by a usual method such as a batting method, a coating method or a spray method. .

According to the above-mentioned method of the present invention, it is possible to obtain a coated cloth which is excellent in waterproofness and moisture permeability and is excellent in washing durability, so-called water resistance retention rate. Furthermore, a resin liquid dispersed or dissolved in an organic solvent solution of a urethane-based resin or a water-based solvent such as a W / O emulsion type polyurethane or an aqueous polyurethane resin is gravureed on the coated cloth obtained by the present invention. By overcoating with a printer or a knife coater, a coated fabric further processed to have high water pressure resistance can be obtained.

The thus-obtained coated fabric of the present invention can be used in a very wide range of applications such as sportswear such as golf wear and ski wear, and winter clothes, rainwear, work clothes and the like.

[0034]

The present invention will now be described in detail with reference to examples. The present invention is not limited to these embodiments. All parts in the examples are parts by weight.

Example 1 300 parts of ethylene butylene adipate having hydroxyl groups at both ends and having an average molecular weight of 3000, 24.49 parts of ethylene glycol and 0.75 part of triethanolamine were uniformly mixed under a nitrogen stream, and diphenylmethane was added thereto. 125 parts of diisocyanate (hereinafter referred to as MDI) and 1800 parts of DMF were added, and the mixture was heated and reacted at 65 ° C. for 6 hours to obtain a polyurethane resin solution having a concentration of 20%. About this polyurethane resin solution, a BH type viscometer at 30 ° C.,
No. When the viscosity was measured with a 7 rotor, the rotation speed was 2
58,000 cps at 0, 750 at 2 revolutions
00cps was obtained, and it was confirmed from this value that the resin solution had a TI value of 1.29 and a non-Newtonian viscosity.

Polyfunctional polyisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd.,
A coating solution was prepared by adding 1 part of coronate EH) and 30 parts of DMF.

On the other hand, a 6 Nylon fiber wool fabric (taffeta) as a base material was subjected to a batting treatment with a 1% aqueous solution of a fluorine-based water repellent emulsion, and a heat treatment was conducted at 160 ° C. for 1 minute. Then, the coating solution obtained above was applied onto a water-repellent substrate with a floating knife coater for 20 minutes.
After applying 0 g / m ² (wet), apply 1 in a 20 ° C water bath.
It was dipped for a minute to solidify the resin component. Then, it was immersed in warm water at 50 ° C. for 10 minutes to sufficiently extract DMF. Then, after drying, batting treatment was performed with a 5% aqueous solution of a fluorine-based water repellent emulsion, and heat treatment was performed at 160 ° C. for 3 minutes to obtain a coated fabric of the present invention.

Example 2 300 parts of butylene adipate having hydroxyl groups at both ends and having an average molecular weight of 3000, ethylene glycol 2
3.93 parts, 7.5 parts of ethylene petriol adipate having hydroxyl groups on both ends and in the molecule and having an average molecular weight of 3000, and 1.06 part of glycerin are uniformly mixed under a nitrogen stream, and 125 parts of MDI and 1070 parts of DMF are mixed therein. Was added and reacted by heating at 75 ° C. for 8 hours to obtain a polyurethane resin solution having a concentration of 30%. When the viscosity at 30 ° C. of this polyurethane resin solution was measured in the same manner as in Example 1, 101500 cps at a rotation speed of 20 and 148,000 cps at a rotation speed of 2 were obtained, and from this value, a non-Newtonian viscosity with a TI value of 1.46 was obtained. It was recognized that the Using this resin solution, a coated cloth was obtained in the same process as in Example 1.

Example 3 600 parts of polycarbonate diol having hydroxyl groups at both ends and having an average molecular weight of 3000, 600 parts of polytetramethylene ether glycol, 6.0 parts of ethylene glycol, 131 parts of dicyclohexylmethane-4,4'-diisocyanate, isophorone Diisocyanate 11
1 part was homogeneously mixed under a nitrogen stream and heated and stirred at 115 ° C. for 3 hours and a half, and then 84.83 parts of isophorone diamine,
Aminoethylethanolamine (0.08 parts), triethyltetramine (0.03 parts) and DMF (3577 parts) were added to give 30
The mixture was heated and reacted at 0 ° C. for 1 hour to obtain a polyurethane resin solution having a 30% concentration. When the viscosity of this polyurethane resin solution at 30 ° C. was measured in the same manner as in Example 1, the number of rotations was 2
50,000 cps at 0, 675 at 2 revolutions
00 cps was obtained, and it was confirmed from this value that the product had a non-Newtonian viscosity with a TI value of 1.35. Using this resin solution, a coated cloth was obtained in the same process as in Example 1.

Example 4 300 parts of ethylene butylene adipate having hydroxyl groups at both ends and having an average molecular weight of 3000, 24.49 parts of ethylene glycol, and 0.67 part of trimethylolpropane were uniformly mixed under a nitrogen stream to obtain 125 parts of MDI,
Add 1800 parts of DMF and heat reaction at 75 ° C. for 6 hours,
A polyurethane resin solution having a concentration of 20% was obtained. The viscosity of this polyurethane resin solution at 30 ° C. was measured in the same manner as in Example 1 and found to be 63,000 c at a rotation speed of 20.
82500 cps was obtained at ps and a rotation speed of 2, and from this value, the TI value was 1.31, and it was confirmed to have a non-Newtonian viscosity. Using this resin solution, a coated cloth was obtained in the same process as in Example 1.

Comparative Example 1 300 parts of ethylene butylene adipate having hydroxyl groups at both ends and having an average molecular weight of 3000 and 24.8 parts of ethylene glycol were uniformly mixed in a nitrogen stream, and M
DI (125 parts) and DMF (1800 parts) were added, and the mixture was heated and reacted at 75 ° C. for 8 hours to obtain a polyurethane resin solution having a concentration of 20%. When the viscosity of this polyurethane resin solution at 30 ° C. was measured in the same manner as in Example 1, it was 60000 cps at a rotation speed of 20 and 60500 cp at a rotation speed of 2.
s was obtained, and from this value, the TI value was 1.01, and it was confirmed that it had Newtonian viscosity. Using this resin solution, a coated cloth was obtained in the same process as in Example 1.

Comparative Example 2 300 parts of ethylene butylene adipate having hydroxyl groups at both ends and having an average molecular weight of 3000, 24.78 parts of ethylene glycol and 0.04 part of triethanolamine were uniformly mixed under a nitrogen stream to obtain 125 parts of MDI, D
Add 1800 parts of MF and react by heating at 65 ° C for 8 hours.
A 0% strength polyurethane resin solution was obtained. When the viscosity of this polyurethane resin solution at 30 ° C. was measured in the same manner as in Example 1, it was 55,000 cp at a rotation speed of 20.
At s and rotation speed 2, 59000 cps was obtained. From this value, the TI value was 1.07, and it was confirmed to have Newtonian viscosity. Using this resin solution, a coated cloth was obtained in the same process as in Example 1.

Comparative Example 3 300 parts of ethylene butylene adipate having hydroxyl groups at both ends and having an average molecular weight of 3000, 23.81 parts of ethylene glycol and 2.38 parts of triethanolamine were uniformly mixed under a nitrogen stream to give 125 parts of MDI, D
Add 1800 parts of MF and heat to react at 60 ° C for 3 hours.
A 0% strength polyurethane resin solution was obtained. When the viscosity of this polyurethane resin solution at 30 ° C. was measured in the same manner as in Example 1, it was 28,000 cp at a rotation speed of 20.
45500 cps was obtained at s and rotation speed 2. From this value, the TI value was 1.62, and it was confirmed that the product had a large non-Newtonian viscosity. Using this resin solution, a coated cloth was obtained in the same process as in Example 1.

With respect to the coated fabrics obtained in Examples 1 to 4 and Comparative Examples 1 to 3, performances such as water pressure resistance and moisture permeability were measured, and the results shown in Table 1 were obtained. The water pressure resistance is J
IS L-1079, water vapor transmission rate is JIS Z-0208,
The washing test is JIS L-1096 6.23.1 (A
The water resistance retention rate is a ratio between the water pressure resistance before washing and the water pressure resistance after repeating washing and drying 10 times.

[0045]

[Table 1]

As is clear from Table 1, the coated fabric obtained by the method of the present invention has good moisture permeability as a moisture-permeable waterproof fabric, and the washing test 1
The water resistance retention rate after 0 times was about 70%, and it was confirmed that the film had high performance. Further, the coating property of the resin solution on the fiber base material was good, and no back leakage was observed at the time of coating. On the other hand, the resin solutions obtained in Comparative Examples 1 and 2 showed back leakage when applied to the fiber base material, and the water resistance retention rate was also very low.
Further, the resin solution of Comparative Example 3 was too viscous and lacked in uniform coatability.

[0047]

As described above, according to the present invention, a monomer having three or more active hydrogens in a molecule and two active hydrogens in a molecule are contained in an elementary component for obtaining a polyurethane resin solution. TI value of 1.10 to 2.00 in combination with monomer
By using a polyurethane resin solution having a non-Newtonian viscosity in the range of 1, the coated fabric having the above-mentioned good moisture permeability and water retention rate can be obtained, such as ski anoraks, sportswear, and raincoats. Suitable for use in

Claims (2)

[Claims] 1. A water-miscible organic compound of a polyurethane resin comprising a polyfunctional monomer having two active hydrogens in the molecule and a polyfunctional monomer having three or more active hydrogens in the molecule, and an organic diisocyanate. A method for producing a coated cloth, which comprises applying a solvent solution to at least one surface of a fiber base material, then dipping in water to extract a water-miscible organic solvent, and then drying. 2. Use of a polyfunctional monomer having 3 or more active hydrogens in the molecule in an amount of 0.1 to 3.0 mol% of the polyfunctional monomer having 2 active hydrogens in the molecule. The method for producing a coated fabric according to claim 1, characterized in that.