KR101817996B1 - Polyurethane for fluoro based water and oil-repellent crosslinking and method for manufacturing thereof - Google Patents

Abstract

The present invention relates to a polyurethane polymer, and more specifically, to a polyurethane polymer for crosslinking a fluorine-based water and oil-repellent and a method for manufacturing the same. An objective of the present invention is to provide a polyurethane polymer for crosslinking a fluorine-based water and oil-repellent which does not deteriorate the stability of the fluorine-based water and oil-repellent, has improved adhesion and washability while being prevented from deteriorating after a frequent use after being treated on the surface of a fabric, etc., and is a self-emulsifying type which can be easily dispersed and dissolved in cold water; and to provide a method for manufacturing the polyurethane polymer.

Description

TECHNICAL FIELD The present invention relates to a method for producing a polyurethane polymer for crosslinking a fluorinated water repellent and a polyurethane polymer prepared by the method,

The present invention relates to a polyurethane polymer, and more particularly, to a process for producing a polyurethane polymer for crosslinking a fluorine-based water repellent agent and a polyurethane polymer produced thereby.

Generally, a technique of treating textile products or paper products with a water- and oil-repellent composition to impart water-repellent, oil-repellent, or water-repellent properties to these surfaces is used for industrial products such as outdoor clothing, sports clothing, umbrellas, tents, And the like. As such a water- and oil-repellent composition, there is known a fluorine-based aqueous dispersion in which a polymer containing polymerized units based on a monomer having a polyfluoroalkyl group is dispersed in water or a mixed solvent of water and an organic solvent (hereinafter referred to as an aqueous medium) have.

As a method of producing such an aqueous dispersion, there is known a method of emulsion-polymerizing a monomer having a polyfluoroalkyl group or a method of emulsifying and dispersing a polymer containing a polyfluoroalkyl group in an aqueous medium using an emulsifier. Various additives are added as needed.

So far, various water and oil repellent compositions have been studied for improvement of water and oil repellency, improvement of durability against washing and friction, improvement of water pressure and oil resistance, and synthetic fibers such as polyester, nylon, acrylic, cotton, There have also been studies to improve the performance of water repellent agents for the same natural fibers, and various methods for raw materials and manufacturing methods for monomers, surfactants, organic solvents, and the like have been proposed.

However, when the fluorine-based water- and oil-repellent composition as described above is treated alone on the outdoor fabric, the performance of the fluorine-based water- and oil-repellent composition is reduced to 50% even three times, and the water-repellent and water-fastness to washing are significantly deteriorated.

In order to solve this problem, the additives may be treated together to lower the stability of the water-repellent and oil-repellent agent, to cause discoloration of the fabric treated with the water- and oil-repellent agent, and to improve the washing resistance and durability It is a very difficult situation.

Korean Patent Publication No. 2003-0095034

SUMMARY OF THE INVENTION It is an object of the present invention to provide a fluorine-based water repellent agent and a fluorine-based water repellent agent which are excellent in adhesion and washing resistance after being treated on a surface of a fabric or the like without impairing the stability of the fluorine- Which can be easily dispersed and dissolved even in cold water, and to provide a polyurethane polymer produced by the method.

(1) a diisocyanate component comprising an aliphatic diisocyanate and a diol component comprising a polyethylene glycol having a weight average molecular weight of 550 to 700 in a weight ratio of 1: 1.8 to 2.1 Preparing a reacted isocyanate-terminated polyurethane prepolymer; And (2) introducing a blocking agent into the isocyanate end of the polyurethane prepolymer to prepare a polyurethane polymer.

According to one embodiment of the present invention, the diol component may further comprise a polyoxyethylene-polyoxypropylene copolymer and a polydialkylsiloxane having a weight average molecular weight of 950 to 1100 and containing a hydroxyalkyl group at both ends thereof have. At this time, the polyoxyethylene-polyoxypropylene copolymer and the polydialkylsiloxane may be reacted with the diisocyanate component in a weight ratio of 1: 0.9 to 1.1 to the polyurethane polymer of the step (2).

In addition, the blocking agent may include at least one selected from the group consisting of aliphatic alcohols having 1 to 5 carbon atoms, aryl alcohols, aromatic amines, oximes, lactams, and active ethylene compounds.

In addition, the copolymer is a polyoxyethylene-polyoxypropylene-polyoxyethylene block copolymer having a number average molecular weight of 1900 to 2100, a number average molecular weight of the reaction product of polyoxyethylene-polyoxypropylene block copolymer and glycerol And a second compound having a molecular weight of 1900 to 2100. At this time, the first compound and the second compound may be reacted with the diisocyanate component in a weight ratio of 1: 2.0 to 2.3 to the polyurethane polymer of the step (2).

Further, the aliphatic diisocyanate may be hexamethylene diisocyanate.

The diol component may further contain trimethylolpropane in an amount of 45 to 55 parts by weight based on 100 parts by weight of the polyethylene glycol.

Also, the aliphatic diisocyanate is hexamethylene diisocyanate, and the diol component in the polyurethane copolymer is a polyoxyethylene-polyoxypropylene-polyoxyethylene block copolymer with a number average molecular weight of 1900 To 2100, a reaction product of a polyoxyethylene-polyoxypropylene block copolymer and glycerol, and 125 to 135 parts by weight of a polyoxyethylene-polyoxypropylene copolymer containing a second compound having a number average molecular weight of 1900 to 2100 45 to 55 parts by weight of trimethylolpropane, and 115 to 130 parts by weight of a polydialkylsiloxane having a hydroxyalkyl group at both ends thereof.

In addition, the blocking agent may include methylethylketoxime and dimethylpyrozole, and more preferably, 1,700 to 1,800 parts by weight of dimethylpyrazole may be included in 100 parts by weight of methylethylketoxime.

The present invention also provides a polyurethane polymer produced by the process according to the present invention, wherein the diisocyanate component and the diol component are polymerized in a weight ratio of 1: 1.8 to 2.1, the diisocyanate is hexamethylene diisocyanate, The diol component is a polyoxyethylene-polyoxypropylene-polyoxyethylene block copolymer having a number-average molecular weight of 1900 to 2100, a polyoxyethylene-polyoxypropylene block copolymer and a polyoxyethylene-polyoxypropylene block copolymer with respect to 100 parts by weight of polyethylene glycol 125 to 135 parts by weight of a polyoxyethylene-polyoxypropylene copolymer containing a second compound having a number average molecular weight of 1900 to 2100 as a reactant, 45 to 55 parts by weight of trimethylolpropane, and 45 to 55 parts by weight of a poly Based repellent agent comprising 115 to 130 parts by weight of a dialkylsiloxane, wherein the end of the polymer is blocked with a blocking agent It provides for a polyurethane polymer.

The present invention also provides a water-repellent fabric comprising a reactive fluorinated water-repellent layer including a polyurethane polymer produced according to the present invention.

According to the present invention, it is possible to spray and dissolve in water without the need of a separate dispersant, because the water-hydrating property is excellent and the stability of the fluorine-based water repellent agent can be prevented from deteriorating. In addition, the water-repellent layer formed by crosslinking the fluorine-based water repellent agent has a washing resistance that is not detached from the fabric even when frequent washing is performed or performance is not deteriorated, and discoloration is prevented so that the appearance quality can be maintained for a long period of time. In addition, it can be applied to the surface of various uses with excellent reactivity with the surface to be treated, and can be widely applied to the whole industry.

1 is an FT-IR graph of a polyurethane polymer according to an embodiment of the present invention.
Figure 2 is a photograph of a dispersion (right) in which a polyurethane polymer according to an embodiment of the present invention is dispersed in water (right) and a dispersion (left) in which a polyurethane polymer according to a comparative example is dispersed in water at room temperature for 3 months to be.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

The polyurethane polymer for crosslinking a fluorine-based water- and oil-repellent agent according to the present invention comprises (1) a diol component comprising a diisocyanate component containing an aliphatic diisocyanate and a polyethylene glycol having a weight average molecular weight of 550 to 700 at a ratio of 1: 1.8 to 2.1 By weight of the isocyanate-terminated polyurethane prepolymer; And (2) introducing a blocking agent into the isocyanate end of the polyurethane prepolymer to prepare a polyurethane polymer.

First, in step (1) according to the present invention, a diisocyanate component containing an aliphatic diisocyanate and a diol component containing polyethylene glycol having a weight average molecular weight of 550 to 700 are mixed at a weight ratio of 1: 1.8 to 2.1 To prepare an isocyanate-terminated polyurethane prepolymer.

The isocyanate-terminated polyurethane prepolymer is formed by reacting with a diisocyanate component and a diol component.

The diisocyanate component comprises an aliphatic diisocyanate.

The aliphatic diisocyanate can be used without limitation in the case of a known aliphatic diisocyanate, but it is preferable to select hexamethylene diisocyanate in order to prevent discoloration after being treated on the surface of the fabric or the like together with the fluorine-based water- .

Next, the diol component includes polyethylene glycol having a weight average molecular weight of 550 to 700, and includes a polyoxyethylene-polyoxypropylene copolymer, a polyoxyethylene-polyoxypropylene copolymer having a weight average molecular weight of 950 to 1100, Alkyl siloxane, and trimethylol propane, and more preferably, all of these components may be contained. Through this, it is possible to produce a self-emulsifiable aqueous dispersion with improved properties, It is advantageous in achieving desired physical properties such as improved washing resistance and discoloration prevention after treatment. At this time, in order to exhibit these improved effects, the diol component preferably contains 125 to 135 parts by weight of a polyoxyethylene-polyoxypropylene copolymer, 45 to 55 parts by weight of trimethylolpropane, and 45 to 55 parts by weight of a hydroxyalkyl group with respect to 100 parts by weight of polyethylene glycol And 115 to 130 parts by weight of a polydialkylsiloxane contained in the step (a).

First, the polyoxyethylene-polyoxypropylene copolymer can improve the water-based dissolution and dispersibility of the polyurethane copolymer produced even without a separate dispersant due to the hydrophilic group. The polyoxyethylene-polyoxypropylene copolymer may be used without limitation in the case of a compound known as a poloxamer, but is preferably a polyoxyethylene-polyoxypropylene-polyoxyethylene block copolymer having a number average molecular weight of A second compound having a number average molecular weight of 1900 to 2100 as a reaction product of a first compound having a molecular weight of 1900 to 2100 and a polyoxyethylene-polyoxypropylene block copolymer and glycerol.

The first compound may have a number average molecular weight of 1900 to 2100 by copolymerizing polyoxyethylene blocks at both ends of the polyoxypropylene block. If the number average molecular weight is less than 1900, hydrophilicity of a desired level is hardly expressed If it exceeds 2100, there is a concern that the hydrophilicity may be lowered or the discoloration may be caused after treatment with the fluorinated water repellent.

The second compound may be a reaction product of a polyoxyethylene-polyoxypropylene block copolymer and glycerol, for example, glycerol propoxylate-block-ethoxylate, and may have a number average molecular weight Can be from 1900 to 2100. If the number average molecular weight is less than 1900, it is difficult to exhibit the desired level of hydrophilicity. When the number average molecular weight is more than 2100, the hydrophilicity may be lowered or the coloring may be caused after treatment with the fluorinated water repellent.

When the first compound / second compound having a number average molecular weight of 1900 to 2100 and the polyethylene glycol having a weight average molecular weight of 550 to 700 are treated together with a diol component, hydrophilicity is improved to improve self-emulsification property, A more excellent water-repellent layer can be formed on the surface to be treated. If it contains the first compound / second compound and polyethylene glycol, if it contains them to deviate from the number average molecular weight, it is difficult to form a uniform water repellent and oil repellent layer during treatment with the fluorinated water repellent agent, The surface quality may be poor.

On the other hand, the first compound and the second compound may be contained in the polyoxyethylene-polyoxypropylene copolymer in a weight ratio of 1: 2.0 to 2.3, thereby exhibiting improved self-emulsifying properties and securing stability with a water- And the like.

Next, the polydialkylsiloxane containing a hydroxyalkyl group at both ends prevents the water-repellent layer from being desorbed or deteriorated in water repellency even in washing. The polydialkylsiloxane has a molecular weight of 950 to 1100, preferably polydimethylsiloxane, which allows it to exhibit excellent film properties when treated with a water repellent.

The polydialkylsiloxane may be preferably included in a weight ratio of 1: 0.9 to 1.1 to the polyoxyethylene-polyoxypropylene copolymer described above and the polyurethane polymer prepared in the step (2) described below. As a result, it is advantageous that these physical properties are expressed in a balanced manner without being deviated to any one of self-emulsifying property, film-forming property and washing resistance.

In addition, the trimethylolpropane plays a role of further enhancing the storage stability at the room temperature of the polyurethane polymer produced in the step (2) so that the polyurethane copolymer is maintained in a dispersed and dissolved state in water for a long time. More preferably, the trimethylolpropane may be included in an amount of 45 to 55 parts by weight based on 100 parts by weight of polyethylene glycol. If the amount is less than 45 parts by weight, stability of long-term storage may be deteriorated. The waterproof performance can be remarkably lowered.

According to one embodiment of the present invention, the aliphatic diisocyanate is hexamethylene diisocyanate, and the diol component is a number average of polyoxyethylene-polyoxypropylene-polyoxyethylene block copolymer with respect to 100 parts by weight of polyethylene glycol A polyoxyethylene-polyoxypropylene copolymer comprising a first compound having a molecular weight of 1900 to 2100 and a second compound having a number average molecular weight of 1900 to 2100 as a reaction product of a polyoxyethylene-polyoxypropylene block copolymer and glycerol, 135 parts by weight of trimethylolpropane, 45 to 55 parts by weight of trimethylolpropane, and 115 to 130 parts by weight of a polydialkylsiloxane containing a hydroxyalkyl group at both ends thereof, in a polyurethane polymer.

In step (1), the diol component is added to the reactor. After the temperature is raised to 90-110 ° C., the inside of the reactor is depressurized at 600-760 mmHg. The moisture is removed to below 0.03 wt% Lt; / RTI > Then, the diisocyanate component was added at a rate of 20 to 40 g / min, and the amount of NCO was measured at intervals of 10 minutes from 20 to 40 minutes after the temperature was raised to 90 to 100 ° C. and maintained at a target NCO of 4.3 to 4.6 The polyurethane prepolymer can be prepared through a process of cooling to 40 ° C.

At this time, the diisocyanate component is added so that the diisocyanate component and the diol component are contained at a weight ratio of 1: 1.8 to 2.1, which can be advantageous for producing a polyurethane polymer having excellent coating film characteristics, self-tackiness and washing resistance . In addition, the NCO equivalent of the diisocyanate to be added as an example may be 1.2 to 1.4 based on the OH equivalent of the diol component.

In addition, a catalyst for promoting the formation of a polyurethane prepolymer may be optionally used, and the catalyst may be a catalyst that is typically used in the formation of a polyurethane prepolymer, for example, dibutyltin dilaurate have.

Next, as step (2) according to the present invention, a step of preparing a polyurethane polymer by introducing a blocking agent into the isocyanate end of the polyurethane prepolymer is carried out.

The blocking agent can be blocked to react with an isocyanate group and can not react with a diol component or other water, and at the same time, when the blocking agent is heated at a predetermined temperature, a blocking agent known to be capable of releasing an isocyanate group May be used without limitation. As a non-limiting example, the blocking agent may include at least one member selected from the group consisting of aliphatic alcohols having 1 to 5 carbon atoms, aryl alcohol, aromatic amine, oxime, lactam, and active ethylene compound. Preferably, however, the blocking agent may comprise methylethylketoxime and dimethylpyrazole, and more preferably dimethylpyrazole at a ratio of 1400 to 100 parts by weight of methylethylketoxime, To 1550 parts by weight.

In the step (2), the polyurethane prepolymer which has reached the target NCO in the step (1) is cooled to 40 ° C or lower, and the blocking agent is gradually added thereto. After the temperature is raised to 80 to 85 ° C, After the content is measured, the NCO becomes 0%, and after re-cooling to 50 ° C or less, ionized water is fed at a rate of 30 to 45 g / min to prepare a dispersion containing the polyurethane polymer.

The dispersion containing the polyurethane polymer prepared by the above-mentioned method may be mixed with the fluorinated water-repellent and oil-repellent agent and then treated to various treatments such as fabric, etc. At this time, for dissociation of the blocking agent, Followed by crosslinking reaction with the fluorine-based water repellent agent to form a water-repellent oil layer on the fabric.

The present invention will now be described more specifically with reference to the following examples. However, the following examples should not be construed as limiting the scope of the present invention, and should be construed to facilitate understanding of the present invention.

≪ Example 1 >

(PE 62) having a number average molecular weight of 2000 as a polyoxyethylene-polyoxypropylene-polyoxyethylene block copolymer with 100 parts by weight of a polyethylene glycol having a weight average molecular weight of 600 as a diol component and a polyoxyethylene-poly 131.6 parts by weight of a polyoxyethylene-polyoxypropylene copolymer containing a second compound (F 203) having a number average molecular weight of 2000 as a reaction product of an oxypropylene block copolymer and glycerol, 50.2 parts by weight of trimethylol propane, And 124.98 parts by weight of polydimethylsiloxane (LKSILPOL-1000) containing a hydroxyalkyl group at both ends thereof were charged into a reactor together with a dibutyltin dilaurate catalyst, and the mixture was heated to 95 ° C. and then heated to 700 mmHg After the decompression, water was removed for 30 minutes and cooled to 25 ° C. Then, hexamethylene diisocyanate was added to the water-removed diol component at a rate of 27 g / min. The hexamethylene diisocyanate and the diol component were added thereto in a weight ratio of 1: 1.93. F-NCO was measured at intervals of minutes. When the temperature reached 4.5, the solution was cooled to 40 ° C, and methylethylketoxime and dimethylpyrazole were slowly titrated with blocking agent. At this time, the dimethylpyrazole was made to be 1489 parts by weight based on 100 parts by weight of methylethylketoxime. When the titration was completed, the temperature was raised to 85 ° C., and F-NCO was measured at intervals of 10 minutes to determine whether the blocking was blocked. When the F-NCO was 0, the solution was cooled to 45 ° C. and ionized water was introduced at a rate of 40 g / A dispersion of 30 wt% dispersed / dissolved pH 6.0 was prepared.

On the other hand, F-NCO was measured based on the isocyanate group content measurement method by ASTM D2572 standard test.

≪ Examples 2 to X >

The dispersion was prepared in the same manner as in Example 1 except that the composition of the diol component was varied as shown in Table 1 below to prepare a dispersion in which the end-blocked polyurethane polymer was dispersed / dissolved as shown in Table 1 below.

≪ Comparative Example 1 &

A commercially available fluorinated water-repellent crosslinking agent (maycanet FM-1, manufactured by Meisei Co., Ltd.) having a solids content of 30 wt% of the polyurethane-based compound was prepared.

<Experimental Example 1>

The FR-IR of the polyurethane polymer prepared in Example 1 was measured and shown in Fig.

Specifically, as can be found in Figure 1, the polyurethane polymer does not appear that the isocyanate peak of 2270cm ^-1, which confirmed that the urethane peak of 1708 cm ^-1 shown, this blocking group is a terminal through a blocking agent with the isocyanate .

<Experimental Example 2>

The following properties of the prepared dispersion were evaluated, and the results are shown in Table 1 below.

1. Cold water solubility and maintenance

The dispersion prepared in 5 ° C cold water was mixed, and the dispersion was mixed with 10 wt% of the mixed solution. After shaking by hand for 1 minute, dissolution / dispersibility was visually confirmed. At this time, when the sample is uniformly dispersed in the container and observed as a semi-transparent liquid, the polyurethane polymer tends not to be aggregated or uniformly dispersed.

Further, regarding the dispersion maintaining property, the above mixed liquid was stored in a refrigerator at 5 ° C for 24 hours, and dissolution / dispersibility was visually checked again to determine the maximum amount of the sample to be 0, It was evaluated as 4 to 1 according to the amount.

FIG. 2 is a photograph showing the mixed solution according to Example 1 and Comparative Example 1 left at room temperature for 3 months and then being dispersed. In the mixed solution according to Example 1 (right), the homogeneous dispersion state is maintained , It can be confirmed that the mixed liquid (left) according to Comparative Example 1 had a solid content precipitated.

2. Water-repellent / water-induced induction after water-repellent treatment and evaluation of water-

To prepare the fluorine-based water-repellent composition, 30 g / L of a fluorine-based water repellent (Unidyne TG-581, Daikin) and 8 g / L of the dispersion prepared in Examples and Comparative Examples were mixed. Thereafter, 100% cotton fabric of black color was immersed in the mixed solution and dried at 120 ° C for 2 minutes. Thereafter, crosslinking was carried out at 170 DEG C for 1 minute to prepare a water-repellent fabric having a water-repellent layer.

Water repellency (AATCC 22 method; 2010) and foot induction (KSK K ISO 14419; 2011) were performed on fabric, and the results are shown.

The fabric was subjected to HL (home laundry) by the AATCC 124 method, and water repellency and foot induction evaluation were performed again.

3. Evaluation of discoloration

1 g of the sample was exposed to 105 ° C for 1 hour and 30 minutes, and the extent of heat discoloration was evaluated. In addition, the samples were evaluated for discoloration according to EN ISO 105 J01 & J03. At this time, the 100% black cotton fabric was L * 97.84, a * 3.49, b * -15.04 C * 15.44 h 283.05, and the discoloration evaluation was evaluated by the change in ΔE * value of the before and after coating. In addition, the degree of thermal discoloration was visually recognized to evaluate the degree of discoloration.

Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 2 Dior
ingredient PEG
(Weight average molecular weight) 600 600 600 600 600 to know
none The first compound
(Number average molecular weight) 2000 Not included 2000 2000 2000 The second compound
(Number average molecular weight) 2000 2000 Not included 2000 2000 Polymethylsiloxane
(Weight average molecular weight) 1000 1000 1000 Not included 1000 Trimethylolpropane include include include include Not included cold water
Solubility Early 5 4 4 5 5 5 After 24 hours 5 3 3 4 One 2 Water repellency HL-0 100 90 90 100 100 90 HL-10 100 80 80 70 70 70 Foot oil HL-0 4.5 3.5 3.5 2.5 4.5 2.5 HL-10 3.5 1.5 1.5 0 1.5 0 Discoloration Thermal discoloration Weak coloration Weak coloration Weak coloration Weak coloration Weak coloration Severe discoloration Discoloration 0.81 1.16 1.25 2.68 1.10 4.06

* In the case of Comparative Example 2, there is no information on the diol component as a commercial product.

* HL-0 is a specimen that has never been washed, and HL-10 is a specimen that has been washed ten times.

As can be seen from Table 1, Example 1, which includes all four components as a diol component according to a preferred embodiment of the present invention, is characterized in that, in comparison with Examples 2 to 5, cold water solubility, water repellency, oil repellency, And it was confirmed that excellent physical properties were obtained in comparison with Comparative Example 1 which was commercialized.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (10)

(1) A polyester resin composition comprising (1) a diisocyanate component comprising an aliphatic diisocyanate, a polyethylene glycol having a weight average molecular weight of 550 to 700, a polyoxyethylene-polyoxypropylene copolymer and a weight average molecular weight of 950 to 1100, Preparing a reacted isocyanate-terminated polyurethane prepolymer to include a diol component comprising a polydialkylsiloxane in a weight ratio of 1: 1.8 to 2.1; And
(2) introducing a blocking agent into the isocyanate end of the polyurethane prepolymer to prepare a polyurethane polymer,
The polyoxyethylene-polyoxypropylene copolymer is a polyoxyethylene-polyoxypropylene-polyoxyethylene block copolymer having a number average molecular weight of 1900 to 2100, a polyoxyethylene-polyoxypropylene block copolymer and a glycerol And a second compound having a number average molecular weight of 1900 to 2100 as reactants, wherein the first compound and the second compound are reacted with the polyurethane polymer of the step (2) so as to be contained at a weight ratio of 1: 2.0 to 2.3, (Method for producing polyurethane polymer for crosslinking water repellent). delete The method according to claim 1,
Wherein the blocking agent comprises at least one selected from the group consisting of aliphatic alcohols having 1 to 5 carbon atoms, aryl alcohol, aromatic amine, oxime, lactam, and active ethylene compound. delete The method according to claim 1,
Wherein the polyoxyethylene-polyoxypropylene copolymer and the polydialkylsiloxane are reacted so as to be contained in the polyurethane polymer of the step (2) at a weight ratio of 1: 0.9 to 1.1. delete The method according to claim 1,
Wherein the aliphatic diisocyanate is hexamethylene diisocyanate; and the aliphatic diisocyanate is hexamethylene diisocyanate. The method according to claim 1,
Wherein the diol component further comprises trimethylol propane in an amount of 45 to 55 parts by weight based on 100 parts by weight of the polyethylene glycol. The method according to claim 1,
Wherein the aliphatic diisocyanate is hexamethylene diisocyanate,
Wherein the diol component further comprises trimethylolpropane,
Wherein the diol component comprises 125 to 135 parts by weight of the polyoxyethylene-polyoxypropylene copolymer, 45 to 55 parts by weight of the trimethylolpropane, and 50 to 55 parts by weight of the polyoxyethylene-polyoxypropylene copolymer having a hydroxyl group at both ends thereof, based on 100 parts by weight of the polyethylene glycol. And from 115 to 130 parts by weight of an alkyl siloxane. delete

Images