KR20030040821A - Composition of water polyurethane and method for processing the same - Google Patents

Abstract

PURPOSE: An aqueous polyurethane resin, its preparation method and a method for preparing artificial leather using the polyurethane resin are provided, to obtain the aqueous polyurethane resin with the alkali resistance and the organic solvent resistance without organic solvent. CONSTITUTION: The aqueous polyurethane resin is prepared by adding dimethylol propionic acid to the blend comprising 0.2-1 mol of a mixture of polytetramethylene ether glycol and polyethylene glycol with an average molecular weight of 400-3,000 and 2 mol of an aliphatic diisocyanate and 0.2-1 mol of an aliphatic diamine; mixing them with triethylamine; and emulsifying the mixture by using a self-emulsifier. The leather is prepared by mixing the polyurethane resin with a crosslinking agent having a carbodiimide represented by -N=C=N=1; and infiltrating the obtained one into textile or coating the obtained one on the surface and the back face of textile.

Description

COMPOSITION OF WATER POLYURETHANE AND METHOD FOR PROCESSING THE SAME

The present invention is applied to synthetic leather and clothing such as shoes and bags by coating the aqueous polyurethane for impregnating nonwoven fabric on the surface and back of fabric and knitted fabric made of artificial leather or polyester fiber, nylon fiber, acrylic fiber, acetone fiber, etc. The synthesis | combination of the aqueous polyurethane which can be done, and its processing method are related.

In recent years, artificial leather is replacing natural leather and has its own unique properties and characteristics, and is gradually expanding the market. In addition, it is widely used as a material for sports and leisure coats, jumpers, etc. by making fluorine resin properties, water-repellent, oil-repellent mechanisms, and processing and clothing. In winter, the weight of clothing was proposed for winter use, and the necessity of imparting breathability and moisture permeability was created.

Conventionally, polyurethanes used to make artificial leather and synthetic leather have been synthesized by a so-called wet method which is dispersed in DMF and MEK solutions, impregnated it in a nonwoven fabric, and then solidified in water. However, when the wet method is used, the DMF eluted into the water is discharged into the river, causing water pollution.

Also, for thin fabrics such as polyester fabrics and nylon fabrics, the polyurethane resin is diluted with organic solvents MEK, toluene and ethyl acetate, and DMF is added if necessary, and then coated on the fabric surface and back. Drying and heat treatment. However, when such a method is used, these solvents are scattered in the air, causing air pollution. Therefore, a method for preventing air pollution is also considered, but there is a problem that large-scale facilities are required and the construction is expensive.

In order to solve this problem, the method of water-emulsifying the polyurethane resin used is taken. The details are described in Japanese Patent Laid-Open No. 9-1132876 and Korean Patent 135550. In this method, aliphatic isocyanate is added to a polyol to prepolymerize it, which is emulsified with a nonionic emulsifier, and then aliphatic diamine is blended to extend the chain. However, since surfactants such as nonylphenol and the like belonging to this emulsifier also cause pollution, the use thereof has many restrictions.

DMF, MEK, Ethyl, which are organic solvents used in the manufacture of resins, which are made of non-woven fabrics and which are given polyurethane to impart cold protection and water repellency to artificial leather. Acetate, toluene, etc. should be discarded and aqueous. In addition, the aqueous polyurethane also needs to be changed from a forced emulsification method to a soap-free self-emulsifying production method. In addition, when using this self-emulsifying polyurethane resin, a crosslinking agent should be blended and dried to enhance the physical properties of the resin itself.

It is therefore an object of the present invention to provide a synthetic synthetic water-based polyurethane having alkali resistance and organic solvent resistance, which can be applied to raincoats, winter clothes and synthetic leather materials for shoes, and a method of processing artificial leather using the resin. .

The present invention is to impregnate a non-woven fabric using a variety of textile materials or to coat the polyurethane and the surface and the back of the fabric and knitted fabrics of various textile materials, the product made in this way to the market. Therefore, the quality requirements are complicated depending on the intended use. At least the following properties must be satisfied. That is, it is important to have sun resistance, alkali resistance, NOx resistance, hydrolysis resistance, solvent resistance (dry cleaning resistance), and not to deteriorate the characteristics of the used fiber material.

In view of the above, isocyanates use aliphatic type, polyols are PTMG, PEG, and aliphatic diamine is used as a chain extender.

Polyurethane resins are generally produced by polymerizing polyols and polyisocyanates as the main raw materials. Polyester polyols and polyether polyols are known as polyols. The former is excellent in sun resistance among physical properties required for fiber processing, but inferior in hydrolysis resistance, particularly alkali-side hydrolysis resistance. Polyether polyols have good hydrolysis resistance but poor sun resistance.

The present invention uses a polyether polyol, but the sun resistance is a linear polyol without branching, and the diisocyanate selects aliphatic. In particular, the polyurethane resistance obtained by addition polymerization of IPDI (Isophorone Diisocynate) and hydrogenated MDI (4,4-Dicyclohexylmethan diisocyannate) can significantly increase the sun resistance.

Specifically, the branched linear poly-α and ω-glycols of the hydrolyzable polyether polyol are preferable. In terms of high strength, the long achelene group is better, but excessively long inhibits urethane bonds. Therefore, PTMG average molecular weight is in the range of 400-3000.

The reason why the PEG is blended is that cracking is likely to occur on the coated surface when PTMG polyol is used alone. The ratio is preferably 0.5% -10% of the entire polyol. If it exceeds this, a polyurethane-coated surface will become cloudy, and if it is small, it cannot prevent gold from grinding. Here, PTMG mixture means what mixes PTMG and PEG polyols, for example as mean mixture of average molecular weight 1000 and 3000.

Aliphatic isocyanates are not specified, but IPDI and hydrogenated MDI mixtures facilitate addition polymerization. Hydrogenated MDI is particularly effective in initial reactions and is advantageous in order to accelerate the reaction.

In the present invention, the aliphatic polyamine is used as a chain extender of polyurethane molecules, and isophoronediamine, dicyclomethadiamine and hexamethylenediamine, or a mixture thereof may be used. When polyurethane impregnation is pre-processed and dyed and post-processed, isophorone diamine is dye-affinity and is more preferable.

The molar ratio of the main component monomers used in the present invention is based on the ratio of PTMG 0.2-1.0 and aliphatic diamine 0.2-0.8 mole having an average molecular weight of 400-3000 to 2 moles of aliphatic diisocyanate. The blending molar ratio determines the adhesion to the fibers and the toughness of the formed film.

If the molecular structure of each component is a similar system, it is flexible and adhesiveness is limited according to the present invention because the adhesion is determined by the number of so-called soft segments of urethane bond chains and hard segments of urea bonds. The range corresponds to the 1.5-4.0 range in terms of soft segments / hard segments.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail.

In the present invention, the method for producing the polyurethane is not particularly limited, but in order to be solubilized, it is necessary to make the polyurethane resin self-emulsifying. For this reason, PTMG and aliphatic diisocyanate are polymerized to produce urethane polymer, and after mixing dimethyl propionic acid to prepolymer, it is soap free with triethanolamine or triethylamine, and then aliphatic diamine is Add and polymerize. In this case, it is not necessary to use surfactants, such as polyoxyalkyl ether and polyoxyethylene alkyl phenol ether, as an emulsifier. As such, since no surfactant is used, no foaming occurs during processing impregnation, and the emulsifier does not move or whiten when coated on the fabric surface.

The polyurethane of the present invention has an OH group and a COO group in itself, and the crosslinking density is increased by using a carbodiimide crosslinking agent in the nonwoven fabric urethane impregnation processing and the coating processing of the fabric, thereby improving washing resistance of the processed product, and And peelability of resin improves.

Commonly used crosslinking agents are block isocyanates which are polyisocyanates, aliphatic and aromatic. Such crosslinking agents are impregnated as hardeners, which improves the toughness of the resin in the coating but hardens more than necessary. In this sense, a carbodiimide-based crosslinking agent was selected.

Example 1

The present invention will be described in detail with reference to the following Examples. In the examples, all parts are parts by weight.

Synthetic polymerization

Molecular Weight part edifice PTMG-1000PEG-1000IPDI Hydrogenated MDI 10141020222.29262.85 168.4618.8373.879.68 0.90.11.80.2

Are mixed and heated to 80 ° C. to form a prepolymer. Moreover, it heats up at 40 degreeC.

DMPATEA 134.13101.19 14.8311.19 0.60.6

Was added, and the mixture was stirred to obtain a urethane prepolymer having a viscosity of 30.000 cps / 40 ° C (BL viscometer No. 4 rotor 6 rpm). Subsequently, the following chain extension was performed (40 ° C x 2hr).

IPDA water 170.30 550.822.9206.10 0.73 system 1076.14

Using the said water-based polyurethane resin, the crosslinking agent free film was created and the physical property was confirmed.

Film making was made of 10cm × 10cm heterogeneous species, poured resin of Example into it and dried naturally, followed by heat treatment at 130 ℃ × 2 minutes, punched out by JIS K-6301 No. 3 dumbbell model to measure film properties.

Measurement result

100% modulus 300% modulus Breaking strength Breaking Break Kg / cm Kg / cm Kg / cm % Example 100 parts of polyurethane 17 23 97 1890 Example 100 parts molybdenum * carbodilite ∑-0.2 parts 17 25 125 1595 Example 100 parts of polyurethane * carbodilite Σ-0.14 parts 23 37 310 1685

* Carbodilite Σ-01 active ingredient 40%

Ionic non-ion

PH 7-10

Carbodiimide Equivalents 425

Carbodiimide equivalent is represented by stoichiometric amount per 1 mol of carbodiimide groups.

Film when we made epidermis layer

(Polyurethane 100 parts / Carbodilite Σ-015 parts mixed film of Example 1)

100% modulus 300% modulus Breaking strength Breaking Break Kg / cm Kg / cm Kg / cm % Initial Film Properties 23 37 310 1685 Physical property after hydrolysis test 20 32 300 1752 Film Properties after Alkali Resistance Test 27 37 335 1585 Physical properties after immersion after dry cleaning 21 30 326 1590 Film properties after tomorrow light irradiation test 21 26 321 1535 Film properties after NOx gas test 21 26 300 1630

Film Property Measurement Method

Initial film making conditions: air-free film formation of a certain thickness by air drying 180 ℃ * 30 minutes heat treatment

Hydrolysis test condition: Initial film was treated at 70 ℃ × 95% RH for one week

Alkali resistance test conditions: Initial film is treated with NaOH x 1 day (20 ℃)

Dry cleaning immersion test condition: Initial film immersed in tetrachloroethylene for 2 hours at room temperature

Tomorrow's daylight irradiation test conditions: 40 ℃ × 63 ℃ irradiation of the initial film using a fading tester

NOx test: Treatment according to JIS L-0855

Example 2

5 parts of carbodiimide crosslinking agents were added to 100 parts of polyurethane resins created in Example 1, and 3.5 parts of nonionic thickeners (manufactured by Kyokuden Kogyo Co., Ltd.) were added to the mixture with sufficient stirring to prepare a viscosity 12,000 cps viscous liquid. did.

This was pad heat treated with a fluorine-based water repellent to a thin cloth polyester tarpta dyeing material and coated on the fabric surface having a water repellency of 80.

This resulted in a pinhole-free and flexible coating on the enameled surface.

Coated Side Molarity

Test result Test Methods Flexibility test More than 200,000 times JIS-K-6545 Surface Wear Test No surface separation Tapered wear 500 g × 1000 times H- (hard wheels) Alkali Resistance Test No surface change Visually immersed in 10% NaOh water for 1 day Peel strength 8.0㎏ / inch NICCA

As described above, the water-based polyurethane according to the present invention has alkali resistance and organic solvent resistance, and the resin can be provided as a raincoat, winter clothes, or synthetic leather material for shoes. In addition, since the present invention is a self-emulsifying aqueous solution, there is no room for the problem of environmental pollution, which has been a problem in the past.

Claims (3)

Dimethylol Propionic (DMPA) in a mixture of 0.2-1 mole of a mixture of polyethylene glycol polyethylene (PTMG), PEG (Polyethylene Glycol), and PEG (Polyethylene Glycol) having an average molecular weight of 400-3000 with respect to 2 moles of aliphatic diisocyanates. Acid), and then an aqueous polyurethane resin synthesized by self-emulsification by mixing TEA (Trithylamine). A method for producing artificial leather by blending a crosslinking agent having a carbodiimide group represented by (-N = C = N-1) to the polyurethane resin, and impregnating a textile fabric, a brushed fabric, a woven fabric or a nonwoven fabric. The artificial resin is prepared by blending a crosslinking agent having a carbodiimide group represented by (-N = C = N-1) to the polyurethane resin, and coating the surface and the back surface of a textile fabric, a brushed fabric, a fabric, and a nonwoven fabric. Way.