JPH01113230A - Moisture-permeable, waterproof cloth - Google Patents

Abstract

PURPOSE:To obtain a cloth having superior moisture permeability and water- proof property, by forming a first resin layer in contact with a fiber fabric by a porous film composed of a specific synthetic polymer and a second resin layer in contact with the first resin layer by a non-porous film composed of a specific synthetic polymer. CONSTITUTION:For a fiber fabric, a woven fabric of mixed spined fibers such as polyamid series synthetic fibers or polyester series synthetic fibers, etc., a nit, a non-woven fabric or the like is used. After a first resin layer having minute apertures is formed on the fiber fabric, a second resin layer is laminated on the first resin layer, which second layer is non-porous. In order to obtain the first resin layer in the form of a porous film, for example, the fiber fabric is applied with a solution of polyurethane resin or PAU resin by the coating method using a knife coater, reverse coater, etc., and then wet-solidified. For forming the second resin layer, by way of example, a solution of PAU resin is coated over the porous resin film by the use of a comma coater, reverse coater, etc., which is then dried.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a moisture-permeable waterproof fabric having excellent waterproof performance.

(Prior Art) As moisture-permeable waterproof fabrics produced by the 7-coating method, moisture-permeable waterproof fabrics in which the resin layer is made of a nonporous membrane and moisture-permeable waterproof fabrics in which the resin layer is made of a porous membrane are well known. A breathable waterproof fabric made of a non-porous membrane.

Although excellent waterproof properties can be obtained due to the properties inherent to resin films, only low moisture permeability can be obtained. On the other hand, moisture-permeable waterproof fabrics are made of porous membranes.

Although it has high moisture permeability, its water pressure resistance is lower than that of non-porous membranes (furthermore, porous membranes become hydrophilic due to the adhesion of sweat and oil during wear and the adsorption of detergent during washing).

This had the disadvantage of causing a decrease in waterproof performance.

(Problem that the invention attempts to solve) The present invention was made in view of the above-mentioned current situation.

Excellent m? that far exceeds the moisture permeability limit of conventional moisture permeable waterproof fabrics made of non-porous membranes. The object of the present invention is to obtain a moisture permeable waterproof fabric which has W performance and has superior waterproof performance compared to a moisture permeable waterproof fabric made of a porous membrane.

(Means for Solving the Problems) The present invention, which achieves the above-mentioned objects, has the following nine-order configuration.

That is, the present invention provides "a moisture-permeable waterproof fabric having two resin layers on a fiber fabric, wherein the first resin layer in contact with the fiber fabric is made of a synthetic polymer mainly composed of polyurethane resin or a synthetic polymer mainly composed of polyamino acid urethane resin. A moisture-permeable waterproof fabric characterized in that the second resin layer in contact with the porous membrane is a non-porous membrane made of a synthetic polymer mainly composed of polyamino acid urethane resin. It is something to do.

Below, nine aspects of the present invention will be explained in detail.

The fiber fabrics used in the present invention include polyamide synthetic fibers such as nylon 6 and nylon 66, polyester synthetic fibers such as polyethylene terephthalate, polyacrylonitrile synthetic fibers, polyvinyl alcohol synthetic fibers, and triacetate synthetic fibers. Synthetic fiber or nylon 6/cotton, polyethylene terephthalate/
Examples include woven fabrics, knitted fabrics, and nonwoven fabrics made of blended fibers such as cotton.

In the present invention, these fiber fabrics may be treated with a water repellent agent. In this case, the t8 water content of the fabric is JIS
It is desirable to have a water repellency of 90 or more by the L-1096 spray method. The I8 water repellent used may be a known one such as a paraffin water repellent, a polysiloxane I8 water repellent, or a fluorine water repellent, and the treatment may be performed by a generally known method.

If particularly good tΩ water resistance is required, use a fluorine-based water repellent9. For example, Asahi Guard 7 manufactured by Asahi Glass Co., Ltd.
After padding 30 (fluorine water repellent emulsion) with a 5% aqueous solution (squeezing ratio 35%).

This may be carried out by a method such as heat treatment at 160° C. for 1 minute.

In the present invention, a porous membrane is formed on the fiber fabric using a synthetic polymer mainly composed of polyurethane resin or a synthetic polymer mainly composed of polyamino acid urethane resin as the first resin layer in contact with the above-mentioned fiber fabric. Also, the second layer in contact with this porous membrane
A non-porous membrane is formed on the first resin layer using a synthetic polymer mainly composed of polyamino acid urethane resin as the resin layer.

Here, the synthetic polymer mainly composed of polyurethane resin refers to one containing 60 to 100% polyurethane resin as one synthetic polymer (of course, 100% polyurethane resin may be used), and as other synthetic polymers.

For example, it may contain polymers such as polyacrylic acid, polyvinyl chloride, polystyrene, polybutadiene, polyamino acids, and copolymers thereof in an amount of less than 30%.

The polyurethane resin used in the present invention is a reaction product containing a polyol having hydroxyl groups at both nine ends, an organic diisocyanate, and a chain extender.

Examples of the polyol component include polyether polyols, polyester polyols, and mixtures or copolymers thereof.

Examples of polyether polyols include polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. Examples of polyester polyols include diols such as ethylene glycol, propylene glycol, and hexamethylene glycol, and adipic acid and cepatic acid.

Examples include polycondensates with dibasic acids such as maleic acid and terephthalic acid, and ring-opening polymers such as caprolactone and lactonic acid.

As the organic diisocyanate component, aromatic diisocyanates, resinous diisocyanates, and alicyclic diisocyanates may be used alone or in mixtures thereof.For example, tolylene-2,4-diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,6-hexane Examples include diisocyanate, 1,4-cyclohexane diisocyanate, and the like.

Examples of the chain extender include compounds having active hydrogen, such as diols such as ethylene glycol, propylene glycol, and hexamethylene glycol, and diamines such as ethylene diamine, metaphenylene diamine, and naphthylene diamine.

What is a synthetic polymer mainly composed of polyamino acid urethane resin? 1 Synthetic polymer contains 70 to 100% of polyamino acid urethane resin.
Of course, 100% polyamino acid urethane resin
But that's fine. ), and contains other synthetic polymers such as block copolymers of poly-T-alkylglutamate and butadiene, block copolymers of poly-γ-alkylglutamate and leucine, etc. in a range of less than 30%. Good too.

Polyamino acid urethane resin used in the present invention (hereinafter referred to as
It is called PAU resin. ) is a copolymer consisting of amino acids and polyurethane, and the amino acids include DL-alanine and L-aspartic acid.

Examples include L-cystine, L-glutamic acid, glycine, L-lysine, L-methionine, L-leucine and their derivatives. When synthesizing polyamino acids, amino acid N-carboxylic anhydride obtained from amino acids and phosgene is used. (hereinafter, N-carboxylic acid anhydride is referred to as NCA)
is generally used, but from the viewpoint of film performance, optically active T
-alkyl-glutamate-NCA is preferably used.

Among them, 9 γ-methyl-L-
Glutamate-NCA or γ-methyl-D-glutamate-NCA is often advantageously selected as the amino acid component of the PAU resin. on the other hand.

As the polyurethane, a urethane prepolymer having an isocyanate group at the end, which is obtained by reacting an isocyanate and a polyol under conditions where the equivalent ratio NGO10H>1, is used. The isocyanate component is aromatic diisocyanate.

Aliphatic diisocyanates and alicyclic diisocyanates may be used alone or in mixtures thereof.

For example, tolylene 2,4-diisocyanate, 4,4°-
Examples include diphenylmethane diisocyanate, 1.6-hexane diisocyanate, and 1.4-cyclohexane diisocyanate. Also.

As the polyol component, polyether polyol, polyester polyol, etc. are used. Examples of polyether polyols include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc., and examples of polyester polyols include reactions between diols such as ethylene glycol and propylene glycol and dibasic acids such as adipic acid and cepatic acid. products.

Examples include ring-opening polymers such as caprolactone.

The amines used in the copolymerization of amino acids and polyurethane include hydrazine, ethylenediamine, diethylamine, and triethylamine.

Ethanolamine etc. are used. in this way.

PAU resins are obtained by adding amines to a reaction system of various amino acids NCA and urethane prepolymers having isocyanate groups at the ends.

As the polymerization solvent used during the synthesis of the PAU resin, a solvent is selected that satisfies two points: it is a polymerization solvent for the amino acid NCA and does not contain active hydrogen, and it can dissolve the urethane prepolymer having terminal isocyanate groups. Examples of such solvents include cyclic ethers such as dioxane and tetrahydrofuran, acetate esters such as ethyl acetate and butyl acetate, ketones such as acetone and methyl ethyl ketone, and polar amide solvents such as dimethylformamide and N-methylpyrrolidone. These can be used as a single solvent or as a mixed solvent. Particularly preferred among these solvent systems are those that dissolve or uniformly disperse the polymer composition to be produced, such as dimethylformamide alone, a mixed solvent of dimethylformamide and dioxane, or a mixed solvent of methyl ethyl ketone and dimethyl formamide. can be mentioned. These solvents are also excellent as solvents in terms of stability and coatability of resin solutions during the production of polyurethane resin films or PAU resin films by coating.

The moisture-permeable waterproof fabric of the present invention is obtained by forming a first resin layer having micropores on a fiber fabric, and then forming a non-porous second resin layer thereon.

The method for forming the porous membrane of the first resin layer is to apply the above-mentioned polyurethane resin solution or PAU resin solution onto the fiber fabric by a conventional coating method 2, such as a coating method using a knife coater, comma coater, reverse coater, etc. Examples include a wet coagulation method, or a method in which a resin solution obtained by modifying a polyurethane resin or PAU resin in advance into a system that is easy to mechanically foam or a W10 type emulsion system is applied onto a fiber fabric and then dried.

As a method for forming the non-porous membrane which is the second resin layer.

Knife coater, comma coater,
After applying the PAU resin solution using a reverse coater etc., 5
A dry method of drying in a gas atmosphere at 0 to 140°C can be mentioned.

The PAU resin solution should be diluted with an appropriate solvent in consideration of workability during coating, and the resin viscosity should be adjusted to 2.000-2.
Adjust to 5.000 cps (25°C) and further.

In order to produce a uniform resin film without pinholes or foreign matter in the PAU resin film, it is desirable to perform filtration with a filter cloth of 20 to 200 meshes and defoaming treatment.

Regarding drying conditions, consider the boiling point of the solvent.

It is important to select the temperature and time to form a uniform non-porous membrane without bubbles or skin core structure. For example, when drying a PAU resin membrane made of dimethylformamide/methyl ethyl ketone mixed solvent,
Drying is preferably carried out under conditions that suppress one shot of the solvent as much as possible, such as at 0° C. for 0.5 to 10 minutes.

In the present invention, in order to improve the peeling resistance between the resin layer and the fiber fabric or resin layer, a compound having high affinity with the resin layer or the fiber base fabric may be used in combination, and in this case, an isocyanate compound is used as the compound. Good to use together. The isocyanate compound is 2,4-tolylene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene isocyanate, or 3 moles of these diisocyanates.

Triisocyanates obtained by addition reaction with 1 mol of a compound containing active hydrogen (eg trimethylolpropane, glycerin, etc.) are used. The above-mentioned isocyanates may be in the form in which the isocyanate group is free, or may be stabilized by adding phenol, methyl ethyl ketoxime, etc., and the blocks may be dissociated by subsequent heat treatment to form an ink-like form.
Either one can be used and should be used appropriately depending on workability, purpose, etc.

The isocyanate compound may be added to the resin solution of the first resin layer or the resin solution of the second resin layer, and
There is no problem in adding it to both of these.

When using an isocyanate compound, the amount used is 0.1 to 0.1 to polyurethane resin and PAU resin.
It is desirable to use it in a proportion of 10% by weight. If the amount used is less than 0.1%, the adhesive strength of the resin to the fabric and the adhesive strength between resin layers will be poor.

On the other hand, if it exceeds 10%, the texture becomes hard, which is not preferable.

Furthermore, in order to improve the moisture permeability of the moisture permeable waterproof fabric of the present invention, at least one compound selected from cellulose acetate, an aqueous polymer, and a plasticizer is added to the PAU resin solution used in the second resin layer. Furthermore, in the present invention, a silicone-containing compound may be added to the above-mentioned PAU resin solution for the purpose of improving wear resistance.

The cellulose acetate mentioned here has a degree of acetylation of 5.
Cellulose diacetate and cellulose triacetate in the range of 0 to 62.5% are used.

Cellulose acetate with an acetylation degree of 50% or less.

Because it swells in hot water, the film becomes less durable. On the other hand, cellulose acetate with an acetylation degree of 62.5% or more is theoretically impossible to synthesize.

The hydrophilic polymer as used in the present invention refers to a polymer compound that is a substance that can be dissolved, dispersed, or emulsified in an organic solvent and has the property of dissolving or swelling in water. If so, polyvinylpyrrolidone, polyvinyl alcohol, polyethylene glycol, polyacrylic acid,
Examples include polyacrylic acid ester, polyvinyl sulfonic acid, polyethyleneimine, carboxymethyl cellulose, etc. In the present invention, an appropriate selection from among these hydrophilic polymers may be used.

In addition, the plasticizer referred to in the present invention has an external plasticizing effect,
It also means a compound that is compatible with the above-mentioned PAU resin, specifically benzoate ester plasticizers such as butyl benzoate and octyl oxybenzoate, dibutyl phthalate and di-2-ethylhexyl phthalate. phthalate ester thread plasticizers such as, benzenetricarboxylic acid ester plasticizers such as trioctyl trimesate and triisodecyl trimellitate, fatty acid ester plasticizers such as dioctyl adipate, diptyl sebacate, dibutyl diglycol adipate, phosphoric acid Examples include phosphate ester plasticizers such as tricresyl and triphenyl phosphate, epoxy plasticizers such as epoxidized soybean oil and butyl epoxystearate, and polyester plasticizers such as polypropylene adipate and polypropylene sebacate. In the present invention, any suitable plasticizer may be selected and used from among these plasticizers.

The silicone-containing compound used in the present invention for the purpose of improving wear resistance refers to a substance that can be dissolved, dispersed, or emulsified in an organic solvent and has a silicone content of 5 to 100% by weight, and is a substance that can be dissolved, dispersed, or emulsified in an organic solvent, and has a silicone content of 5 to 100% by weight. Synthetic polymer 2 such as polyurethane, polystyrene.

It may also be a mixture or copolymer with polyvinyl chloride or the like. Silicone rubbers include silicone oil, silicone resin, silicone rubber, etc. Among these, silicone oil is made of linear polysiloxane, specifically dimethylpolysiloxane, methylhydrodienepolysiloxane, methylphenylpolysiloxane. , epoxy-modified dimethylpolysiloxane, amino-modified dimethylpolysiloxane, carboxyl-modified dimethylpolysiloxane, alcohol-modified dimethylpolysiloxane, fluorine-modified dimethylpolysiloxane, and the like. Silicone resin is a mixture of bifunctional silanes such as dimethyldichlorosilane and methylhydrodiene dichlorosilane and trifunctional silanes such as methyltrichlorosilane and hydrolyzed. Specifically, silicone resins include methyl polysiloxane resin and Examples include methyl phenyl polysiloxane resin. Silicone rubber is a high molecular weight product of silicone oil and is a candy-like elastic gel-like substance, and includes vinyl silicone rubber, nitrile silicone rubber, and the like.

When using a silicone-containing compound in the present invention, at least one of the above may be used.

Regarding the amounts used when the PAU resin is made to contain the aforementioned cellulose acetate, TLT aqueous polymer, plasticizer, etc., even when these are used alone.

Even when used in combination, the amount used is preferably in the range of 5% to 200% by weight based on the solid content of the PAU resin. On the other hand, if it is less than 5%, the moisture permeability effect on the PAU resin film is poor.

If it exceeds 200%, the mechanical properties of the PAU resin film will deteriorate.

Further, when the silicone-containing compound is contained in the PAU resin, the amount used is preferably in the range of 1% by weight to 100% by weight based on the solid content of the PAU resin. If it is less than 1%, the abrasion resistance effect on the PAU resin film will be poor, while if it exceeds 100%, the mechanical properties of the PAU resin film will deteriorate.

The present invention has the above configuration, and according to the present invention, a moisture permeable waterproof fabric having high moisture permeability and waterproof performance can be obtained.

(Function) In the moisture permeable waterproof fabric of the present invention, the first resin layer in contact with the fiber fabric is a porous membrane made of polyurethane resin or PAU resin (polyamino acid urethane resin), and the second resin layer in contact with the porous membrane is made of polyurethane resin or PAU resin (polyamino acid urethane resin). The layer is composed of a nonporous membrane made of PAU resin, and has high moisture permeability. Since the second resin layer of this moisture-permeable waterproof fabric is non-porous, there is no drop in water pressure due to dirt adhesion or detergent adsorption when worn, and the fabric has excellent waterproof performance.

Although it is not necessarily clear why the moisture-permeable waterproof fabric of the present invention has high moisture-permeability, the inventors of the present invention speculate as to the reason as follows.

Moisture-permeable waterproof fabrics made by directly dry-coating polyurethane resins or PAU resins have a problem in that even if the non-porous membrane is made thinner, the resin liquid will penetrate between the threads that make up the fiber fabrics, resulting in The resin film has become thick and has low moisture permeability.9 However, the moisture permeable waterproof fabric of the present invention makes the first resin layer porous, thereby making the second resin layer non-porous. PAU resin, on the other hand, allows the membrane to be thinned without penetrating between the yarns.

It is constructed by block copolymerization of amino acids and urethane. The amino acid block mainly forms an α-helical structure, and the urethane block forms a random coil structure. In particular, the former amino acid block Due to its wax structure, it has a tendency to promote the diffusion of water vapor, and as a result of the combination of the α-helical structure of PAU resin and the thinning of the non-porous membrane of PAU resin, the transparent membrane of the present invention It is presumed that the wet waterproof fabric has come to exhibit a high degree of moisture permeability.

(Example) Next, the present invention will be described in more detail with reference to 9 Examples. Performance measurements and evaluations in the Examples were performed in the following manner.

(11 Moisture permeability: Based on JIS-Z-0208.

(2) Water pressure resistance: Based on J I 5-L-1096 (low water pressure method).

Example 1 First, nylon tricot half (both front yarn and back yarn are nylon (FD) 40d/10f) was used as the base fabric.
used, number of courses 53/inch, number of wales 44/inch)
, which is then scoured and dyed with acid dyes in the usual manner.

Padding with a 5% aqueous solution of fluorine water repellent emulsion Asahi Guard 710 (Asahi Glass product) (squeezing rate 80%)
)L, heat treatment was performed at 160° C. for 1 minute.

A polyurethane resin solution of the following formulation 1 was applied onto this base fabric using a reverse coater at a coating rate of 180 g/rd, and then dried at 70°C for 2 minutes.

A porous membrane (film thickness: 15 μm) as the first resin layer was formed.

Formulation 1 Heimlen X-'3038 100 parts (Dainichiseika Kakogyo a @ product) Rezamin
18 parts water
50 parts Next, a PAU resin (polyamino acid urethane resin) used as the second resin layer was manufactured by the following method.

Polytetramethylene glycol (OH value 56.9) 19
70g and 50g of 1,6-hexamethylene diisocyanate
4g was reacted at 90°C for 5 hours to obtain a urethane prepolymer with isocyanate groups at the end (NGO equivalent weight 234
0) was obtained. This urethane prepolymer 85 ghr-
When 85 g of methyl-L-glutamic acid)-NCA was dissolved in 666 g of a mixed solvent of dimethylformamide/dioxane (weight ratio 7/3), 50 g of 2% triethylamine solution was added while stirring, and the reaction was carried out at 30°C for 5 hours. .

PAU resin (hereinafter referred to as PAU resin

) was obtained.

Next, on the surface of the first resin layer described above, formulations 2 to 2 in Table 1 below are applied.
After applying the PAσ resin solution shown in 6 using a knife-over roll coater and adjusting the coating amount appropriately so that the dry film thickness of the PAU resin film was 8 μm, the solution was coated at 60°C for 10 minutes.
Drying was carried out for 1 minute to obtain 5 moisture permeable waterproof fabrics (A-E) of the present invention.

(Hereinafter, blank space) Table 1 (Unit double placement part) The PAU resin solutions of formulations 2 to 6 were filtered under reduced pressure with a 100 mesh polyester filter cloth (100 fins, 11 g).
This was followed by defoaming treatment at a reduced pressure of 100 fin Hg for 20 minutes.

For comparison with the present invention, the formulation 1 of this example was applied to the in-water treated nylon tricot half used in this example. Coating amount of formulation 2 coating liquid: 120g/durable, 160g/respectively.
After coating using a reverse coater at 60° C., drying was performed for 10 minutes at 60° C.

Comparative example 1. A moisture permeable waterproof fabric of Comparative Example 2 (each having a film thickness of 23 μm) was produced.

The performance of the moisture permeable waterproof fabrics of the present invention and Comparative Examples 1 and 2 was measured and evaluated, and the results are shown in Table 2.

(Hereinafter, blank space) Table 2 In Table 2, the performance of the moisture permeable waterproof fabrics of the present invention (A-E) is compared to Comparative Example 1. As is clear from the comparison with the performance of Comparative Example 2, the moisture permeable waterproof fabric of the present invention has a higher performance.

Both of them are much higher in waterproofness than Comparative Example 10M fW waterproof fabric, which consists of only a porous membrane, and are moisture permeable while maintaining the same level of waterproofness as the moisture-permeable waterproof fabric of Comparative Example 2, which consists of only non-porous membrane. It can be seen that the performance has improved surprisingly.

Example 2 Using the PAU resin used in Example 1 above, a moisture permeable waterproof fabric of the present invention was manufactured by the following method.

First, we used nylon 70 denier/34 filament for both the warp and weft as the base fabric, with a warp density of 120 threads/
A plain woven fabric (taffeta) with a weft density of 90 yarns/;' is prepared, and after scouring and dyeing with acid dye in the usual manner, Asahi Guard 7IO (Asahi Glass Co., Ltd.), a fluorine-based Iθ water emulsion, is prepared. Company product) Padded with a 5% aqueous solution (squeezing ratio 35%) L and heat treated at 160° C. for 1 minute. Next, using a calendering machine with mirror-finished rolls, the temperature was 160°C, the pressure was 30kg/cm, and the speed was 20°C.
Calendar processing was carried out under the conditions of m/min, and then 9100 g of a resin solution with a resin solid content concentration of 20% shown in Formulation 7 below was applied using a knife over roll coater.
/lri, and then immersed in an aqueous solution at 15° C. for 40 seconds to solidify the resin. Subsequently, it was washed in warm water at 50°C for 10 minutes.

It was dried to form a porous membrane (film thickness: 20 μm) as the first resin layer.

Formulation 7 100 parts of PAU resin X 10 parts of Kuribon AW-7H 2 parts of Kuribon BL-50
The PAU resin solutions shown in Prescriptions 2 to 6 in the table were coated using a knife-over roll coater, adjusting the coating amount appropriately so that the dry film thickness of the PAU resin film was 8 μm, and then coating at 60°C for 10 minutes. Drying was carried out under the conditions of 2 minutes to obtain 5 moisture permeable waterproof fabrics (F-J) of the present invention.

The performance of the moisture permeable waterproof fabric of the present invention was measured and evaluated.

The results are shown in Table 3.

Table 3 As is clear from Table 3, the moisture permeable waterproof fabric of the present invention has surprisingly improved moisture permeability without impairing its waterproof properties.

(Effects of the Invention) In the moisture permeable waterproof fabric of the present invention, the first resin layer in contact with the fiber fabric is a porous membrane made of polyurethane resin or PAU resin, and the second resin layer in contact with the porous membrane is made of PAU resin. According to the present invention having such a structure, the disadvantages of conventional porous type moisture permeable waterproof fabrics and nonporous type moisture permeable waterproof fabrics can be fully compensated for, and the high A moisture-permeable waterproof fabric having both waterproof performance and moisture permeability can be obtained.

The moisture permeable waterproof fabric of the present invention is a material particularly suitable for sports clothing due to its excellent performance.

Claims (1)

[Claims] (1) A moisture-permeable waterproof fabric having two resin layers on a fiber fabric, in which the first resin layer in contact with the fiber fabric is made of a synthetic polymer mainly composed of polyurethane resin or a synthetic polymer mainly composed of polyamino acid urethane resin. 1. A moisture-permeable waterproof fabric characterized in that it is a porous membrane, and a second resin layer in contact with the porous membrane is a non-porous membrane made of a synthetic polymer mainly composed of polyamino acid urethane resin.