KR100785349B1 - Water dispersed polyurethane with an excellent anti-solvent property and manufacturing method thereof - Google Patents

Abstract

A solvent-resistant water-dispersible polyurethane dispersion is provided to improve solvent resistance for applying it to a surface coating agent for a mobile phone base and top coat, a coating agent for automobiles and a film hard coating agent. A solvent-resistant water-dispersible polyurethane dispersion is prepared from an NCO-terminated polyurethane prepolymer obtained by the reaction of a polyol comprising a polycarbonate diol as a main component, an organic diisocyanate comprising norbornane diisocyanate, dicyclohexyl methane diisocyanate or their mixture, and a hydrophilic diol. The polyol comprises a triol, the equivalence ratio of the triol and the organic diisocyanate is 5:1 to 30:1, and the polyurethane prepolymer contains 1-8 % of terminal NCO.

Description

Water-dispersed polyurethane with excellent solvent resistance and its manufacturing method {WATER DISPERSED POLYURETHANE WITH AN EXCELLENT ANTI-SOLVENT PROPERTY AND MANUFACTURING METHOD THEREOF}

The present invention relates to a water dispersion polyurethane having excellent solvent resistance, and more particularly, to a water dispersion polyurethane having excellent solvent resistance using a polycarbonate polyol.

Polyurethanes are manufactured in a wide variety of products such as rigid foams, flexible foams, films, soft and rigid elastomers and fibers, and the like. The polyurethane industry has been developed in Korea as the center of household goods, such as clothing, shoes, bags, toys, sofas, beds, etc. related to daily life until the 1980s, and is now used in heavy chemical industry such as automobile, electronics, civil engineering, shipbuilding, etc. As used, the market continues to grow. Recently, due to environmental problems, polyurethane coatings have been in the spotlight due to enhanced emission regulations such as organic solvents and VOCs (volatile organic compounds).

Looking at the prior art associated with the present invention, US Pat. No. 5,504,145 proposes a method for preparing a water-dispersed polyurethane resin by introducing dimethylolpropionic acid to a hydrophilic group. US Pat. No. 5,672,653 also describes a process for producing anionic water dispersible polyurethanes using polybutanediol terminated with hydroxyl groups. In this patent, a method for synthesizing anionic water-dispersed polyurethane is proposed. First, a prepolymer is prepared from a polybutadiene terminated with a hydroxyl group, a diol having an aromatic isocyanate and a carboxyl group, and then neutralized with triethylamine and then dispersed in water. It introduces. In addition, U.S. Patent No. 5,086,110 describes a composition for improving water resistance and physical properties by using 1,12-dodecane diisocyanate, polyoxytetraethylene glycol, dimethylolpropionic acid and triethylamine and 1,4-cyclohexadiamine. Producing a water-dispersible polyurethane. On the other hand, in the United States Patent No. 5,717,024, in the preparation of water-dispersed polyurethane, carbon dioxide is generated when water is contacted with isocyanate groups when water is dispersed.

However, in the case of water-dispersed polyurethane, there have been environmental problems while low solvent resistance. When the solvent resistance is low, there have been problems that it is difficult to use in the application areas that are in contact with the solvent, for example, cell phone base and top coating, surface coating for steel, automotive coating, film hard coating.

Accordingly, there is a continuing demand for polyurethanes having solvent resistance.

It is an object of the present invention to provide a polyurethane with enhanced solvent resistance.

Another object of the present invention is to provide a water-dispersed polyurethane with enhanced solvent resistance.

Another object of the present invention is to provide a method for producing a water-dispersed polyurethane with enhanced solvent resistance.

In order to achieve the above object, the water-dispersed polyurethane of the present invention

It consists of a water-dispersed polyurethane dispersion prepared from NCO terminated polyurethane prepolymers prepared by reacting polyols based on polycarbonate polyols with aliphatic polyisocyanates and hydrophilic diols.

In the present invention, the polycarbonate polyol contains at least one carbonate group and at least two hydroxy groups in the main chain.

In the practice of the present invention, the polycarbonate polyol may be prepared by a known method, and examples thereof include a reaction of aliphatic or aromatic polyols with phosgene and transesterification of carbonic esters. The manufacturing method of aliphatic polycarbonate polyol is a manufacturing method by transesterification of carbonic ester. In addition, Belgian patent publication No. 630,530 (1963) discloses a method for producing a high molecular weight polycarbonate polyol having a narrow molecular weight distribution from cyclic carbonate. For example, it can obtain by substitution reaction of ethylene glycol carbonate and the diol which has various structures.

In the present invention, the polycarbonate polyol preferably has a molecular weight of about 600-6000, more preferably about 1000-3000. If the molecular weight is low, the hardness of the final product may be increased and cracks may occur, and if the molecular weight is too high, there is a problem that the hardness characteristics fall.

In the practice of the present invention, the polycarbonate polyol may be polycarbonate diol or polycarbonate triol, preferably polycarbonate diol. The polycarbonate diol is also commercially available, preferably Carb 100 of Ube, Japan.

In the present invention, the polyol is a polycarbonate polyol as a main component, it is preferable to use at least 60% by weight, more preferably 70% by weight, even more preferably in order to ensure that the final product retains solvent resistance It is recommended to use more than 80% by weight.

In the present invention, the polyol may include a triol to increase the solvent resistance by increasing the degree of crosslinking in addition to the polycarbonate polyol. In the present invention, the triol may include trimethylolpropane, polycaprolactam triol, or trifunctional epoxy.

In the practice of the present invention, the triols can be purchased and used commercially, trimethylolpropane can be purchased Hansol Chemical products of the Republic of Korea, polycaprolactam triol to use Tone0310 of Japan UCC Co., Ltd. having a molecular weight of 900 The OH trifunctional epoxy may be a product of Nicechem of Korea having an epoxy equivalent of 140 to 155.

In the present invention, it is preferable that the triols have an equivalent ratio of isocyanate to triols of about 5: 1 to 30: 1. When the amount of the triol used is large, the viscosity increases during the reaction, making it difficult to use. When the amount of the triol used is small, the hardness, the solvent resistance, and the like may decrease.

In the present invention, the polyisocyanate reacted with the polyol is an aliphatic polyisocyanate. Aromatic polyisocyanates may yellow when used with polycarbonate polyols.

In the present invention, the polyisocyanate affects the solvent resistance of the water-dispersed polyurethane with the use of the polycarbonate polyol. In a preferred embodiment of the invention, the polyisocyanate is a polyisocyanate comprising noborane diisocyanate, dicyclohexyl methane diisocyanate or mixtures thereof such that the final water-dispersed polyurethane has sufficient solvent resistance. In a preferred embodiment of the present invention, the polyisocyanate comprises at least 50% by weight, preferably at least 70% by weight, more preferably at least 80% by weight of noborane diisocyanate, dicyclohexylmethane diisocyanate or mixtures thereof. Polyisocyanate.

In the present invention, the diol having a hydrophilicity introduced into the prepolymer chain to disperse the polyurethane prepolymer is introduced so that the polyurethane prepolymer can be dispersed in water, preferably hydrophilicity is dimethylolpropionic acid, Dimethylol butanoic acid etc. can be used.

In the present invention, the organic solvent used in the preparation of the polyurethane prepolymer may be used a conventional organic solvent known in the art, for example, benzene, toluene, ethyl acetate, acetone, methyl ethyl ketone, di Ethyl ether, tetrahydrofuran, methyl acetate, acetonitrile, chloroform, methylene chloride, carbon tetrachloride, 1,2-dichloroethane, 1,1,2-trichloroethane, tetrachloroethylene, N-methylpyrrolidone, dipropylene Glycol dimethyl ether and the like, and these may be used alone or in combination. In a preferred embodiment of the present invention, it is preferable to use dipropylene glycol dimethyl ether which is a non-toxic organic solvent.

In the present invention, the polyurethane prepolymer has a terminal NCO% of 1-8%, preferably 3-7%, most preferably 6%. Hardness if terminal NCO% is low. If the solvent property is lowered and the amount is decreased, the physical properties are improved, but storage stability becomes a problem.

The water-dispersed polyurethanes according to the invention are obtained by dispersing polyurethane prepolymers in water according to conventional methods. In a preferred embodiment of the invention, the polyurethane prepolymer is prepared by reacting with triethylamine to dissolve it, chain extending with a chain extender such as ethylene diamine and dispersing it.

Hereinafter, the present invention will be described in more detail with reference to the following examples.

Example

Example 1

Prepare a clean 4L flask, stirrer, mantle, cooling tube, etc., and add 765 g of polycarbonate diol (Ube Carb 100 (molecular weight 1000)), 55.6 g of dimethylol propionic acid, and 285 g of non-toxic solvent dipropylene glycol dimethyl ether. After raising the temperature for 1 hour, purge with nitrogen for 1 hour, dehydrate and hold for 1 hour, dissolve, cool to 75 ° C, add 523 g of 4,4-dicyclohexyl methane diisocyanate, 266 g of dipropylene glycol dimethyl ether, and at this time, dibutyltin dilaurate After adding with 0.15g and reacting at 85 ° C for 4 hours, 0.05g of dibutyltin dilaurate was further added at the same temperature and then maintained for 3 hours to prepare a terminal NCO prepolymer.

Into a 4L beaker equipped with a separate stirrer, 1.020 g of ion-exchanged water, 26 g of isopropyl alcohol, and triethylamine were added to the prepared prepolymer as much as the remaining carboxyl equivalent and 825 g of the prepared polyurethane prepolymer was stirred. After neutralizing with sufficient stirring for 1 hour, 81 g of ion-exchanged water and poly (PS) 520Na, a diamine, were diluted with ion-exchanged water as NCO equivalents remaining in the prepolymer, and then heated to 70 ° C. and chained for 2 hours. After extension, the mixture was cooled to room temperature to prepare a transparent, water-soluble urethane resin having a pH7.6 of solid content of 30%.

Example 2.

Prepare a clean 4L flask, stirrer, mantle and cooling tube, add 536 g of polycarbonate diol (Ube Carb 100 (molecular weight 1000)), 55.6 g of dimethylpropionic acid, 19.5 g of trimetholpropane, and 285 g of dipropylene glycol dimethyl ether. After raising to 115 ° C., purging with nitrogen for 1 hour, dehydrating, holding for 1 hour, dissolving and cooling to 75 ° C., 518 g of 4,4-dicyclohexyl methane diisocyanate and 266 g of dipropylene glycol dimethyl ether were added. After adding 0.15 g of tin dilaurate and reacting at 85 ° C. for 4 hours, 0.05 g of dibutyl tin dilaurate was further added at the same temperature and then maintained for 3 hours to prepare a terminal NCO prepolymer.

Separately, 30 g of 980 g isopropyl alcohol in a 4 L beaker equipped with a stirrer. Triethylamine is added to the prepolymer as much as the remaining carboxyl equivalent and stirred, followed by strong stirring while adding 835 g of the synthesized prepolymer to neutralize. After neutralizing sufficiently for 1 hour, 81 g of ion-exchanged water and PolyPS 520Na were diluted and added to the ion-exchanged water by the remaining NCO equivalent of the prepolymer, and the temperature was raised to 70 ° C., followed by chain extension for 2 hours, followed by cooling to room temperature. To prepare a transparent and water-soluble urethane resin of pH 7.0 solids 29%.

Example 3

Prepare a clean 4L flask, stirrer, mantle, cooling tube, and so on, 575 g of polycarbonate diol (Ube Carb 100 (molecular weight 1000)), 120 g of UCC Tone0310 (molecular weight 900), polycaprolactam triol, 55.6 g of dimethylpropionic acid, dipropylene glycol 285 g of dimethyl ether was added thereto, heated to 115 ° C., purged with nitrogen for 1 hour, maintained for 1 hour while dehydrated, dissolved, cooled to 75 ° C., 532 g of 4,4-dicyclohexyl methane diisocyanate and 236 g of dipropylene glycol dimethyl ether. In this case, the reaction mixture was added with 0.15 g of dibutyl tin dilaurate, and then reacted at 85 ° C. for 4 hours, 0.05 g of dibutyl tin dilaurate was further added at the same temperature, and then maintained for 3 hours to prepare a terminal NCO prepolymer.

Then, 20 g of isopropyl alcohol 1.020 g iso-exchanged water in a 4L beaker equipped with a separate stirrer. Triethylamine is added to the synthesized prepolymer by the amount of the remaining carboxyl equivalent, and the mixture is stirred while vigorously stirring to neutralize the prepared prepolymer. After neutralizing sufficiently for 1 hour, 81 g of ion-exchanged water and PolyPS 520Na were diluted and added to the ion-exchanged water by the remaining NCO equivalent of the prepolymer, and the temperature was raised to 70 ° C., followed by chain extension for 2 hours. Cooling was transparent to prepare a water-soluble urethane resin of pH 7.2 solids 30%.

Example 4

Prepare a clean 4L flask, stirrer, mantle, cooling tube, etc., and add 543 g of polycarbonate diol, 53 g of trifunctional epoxy with 140 to 155 epoxy equivalents, 59 g of dimethylpropionic acid, and 285 g of dipropylene glycol dimethyl ether. After raising the temperature to 1 hour with nitrogen purge, dehydrated and maintained for 1 hour, dissolved, cooled to 75 ℃, 512 g of 4,4-dicyclohexyl methane diisocyanate and 250 g of dipropylene glycol dimethyl ether were added and dibutyltin dilaurate 0.15 After the reaction with 4 g at 85 ° C. for 4 hours, 0.05 g of dibutyltin dilaurate was further added at the same temperature and then maintained for 3 hours to prepare a terminal NCO prepolymer.

Then, 30 g of ion-exchanged water 980 g isopropyl alcohol in a 4 L beaker equipped with a separate stirrer. Triethylamine is added to the synthesized prepolymer as much as the remaining carboxyl equivalent, while stirring, and neutralized by vigorous stirring while adding 835 g of the synthesized prepolymer. Then, after neutralizing sufficiently for 1 hour, 81 g of ion-exchanged water and polyPS 520Na are added thereto. The remaining NCO equivalents of the prepolymer were diluted and added to ion-exchanged water, and then heated to 70 ° C., followed by chain extension for 2 hours, and then cooled to room temperature to prepare a transparent, water-soluble urethane resin having a pH7.6 solid content of 30%.

Example 5

Prepare a clean 4L flask, stirrer, mantle, cooling tube, etc., add 536g of polycarbonate diol, 55.6g of dimethylpropionic acid, and 320g of ethyl acetate to 19.5g of trimetholpropane. 518 g of lohexyl methane diisocyanate and 280 g of ethyl acetate were added together with 0.15 g of dibutyltin dilaurate, and then reacted at 85 ° C. for 4 hours, after which 0.05 g of dibutyltin dilaurate was further added at the same temperature. After maintaining the reaction time, the reaction mixture was cooled to 60 ° C., and triethylamine was added as much as the remaining carboxyl equivalent to maintain 1 hour at the same temperature to prepare a terminal NCO prepolymer.

Separately, 1.230 g of ion-exchanged water in a 4L beaker equipped with a stirrer. Dilute ethylenediamine with the remaining NCO equivalents of the synthesized prepolymer, add 850 g of the synthesized prepolymer, raise the temperature to 80 ° C with vigorous stirring, and extend the chain while recovering ethyl acetate under vacuum for 4 hours to recover the ethyl acetate. A water-soluble urethane resin with a pH7.5 solid content of 30% was prepared.

Comparative Example 1

Cleanly prepared 4 L flask and stirrer. mantle. Cooling tubes and the like were prepared, and Daewon polymer (diol molecular weight 1.000 adipic acid and 1.4BD alone) 765g, dimethyrolpropionic acid 55.6g. 285 g of dipropylene glycol dimethyl ether was added thereto, heated to 115 ° C., purged with nitrogen for 1 hour, maintained for 1 hour while dehydrated, dissolved, and cooled to 75 ° C. to 523 g of 4,4-dicyclohexyl methane diisocyanate and dipropylene glycol dimethyl. 266 g of ether was added thereto, followed by reaction with 0.15 g of dibutyl tin dilaurate and reaction at 85 ° C. for 4 hours. After addition of 0.05 g of dibutyl tin dilaurate at the same temperature, the reaction was continued for 3 hours. A polymer was prepared.

Then, in a 4L beaker equipped with a separate stirrer, 1.030 g of ion-exchanged water. 30 g of isopropyl alcohol. Triethylamine is added by the amount of the remaining carboxyl equivalent of the synthesized prepolymer, and the mixture is stirred while being vigorously stirred to neutralize the prepared prepolymer. After neutralizing sufficiently for 1 hour, 81 g of ion-exchanged water and PolyPS 520Na were diluted and added to the ion-exchanged water by the remaining NCO equivalents of the synthesized prepolymer, and the temperature was raised to 70 ° C., followed by chain extension for 2 hours. Cooled to a transparent and prepared a water-soluble urethane resin of pH 7.0 solids 30%.

Comparative Example 2

Cleanly prepared 4 L flask and stirrer. mantle. Cooling tubes and the like were prepared with Daewon polymer (diol molecular weight 1.000 adipic acid and 1.4BD alone) 465 g, PCD carb 300 g, dimethyrol propionic acid 55.6 g. 285 g of dipropylene glycol dimethyl ether was heated to 115 ° C., purged with nitrogen for 1 hour, maintained for 1 hour while dehydrated, dissolved, and cooled to 75 ° C. to 523 g of 4,4-dicyclohexyl methane diisocyanate and dipropylene glycol dimethyl ether. 266g was added and dibutyltin dilaurate was added together with 015g and reacted at 85 ° C for 4 hours. After adding 0.05g of dibutyltin dilaurate at the same temperature and maintaining the solution for 3 hours, the terminal NCO prepolymer was added. Was prepared.

Then, in a 4L beaker equipped with a separate stirrer, 1.030 g of ion-exchanged water. 30 g of isopropyl alcohol. Triethylamine is added to the synthesized prepolymer by the amount of the remaining carboxyl equivalents, and the mixture is stirred and neutralized by vigorous stirring while adding 835 g of the synthesized prepolymer. After neutralizing sufficiently for 1 hour, 81 g of ion-exchanged water and PolyPS 520Na were diluted and added to the ion-exchanged water by the remaining NCO equivalents of the synthesized prepolymer, and the temperature was raised to 70 ° C., followed by chain extension for 2 hours. Cooled to a transparent and prepared a water-soluble urethane resin of pH 7.0 solids 30%.

Solvent resistance test

To the addition of additives and the like in the composition of Table 1 to prepare a water dispersion polyurethane coating solution, to form a coating film was measured the overall physical properties including solvent resistance and hardness, gloss, adhesion. Here, as an additive, PA-14, a Dowcony additive, surfynol # 465, an air product wetting agent, WS-500, a crosslinker, and tego # 805 (Tego's Deformer) are added together with IPA and water. It was prepared by.

Solvent resistance was measured by coating film specimens having a thickness of 0.7 mm x 2 cm x 5 cm (70 ° C x 24hrs) and immersing them in methyl ethyl ketone and isopropyl alcohol for 3 days and then considering the abnormality of the coating film.

The hardness was 0.9mm in thickness to make a coating film specimen (70 ° Cx24hrs) was measured by the Shure D hardness meter.

Gloss measurement was carried out by applying 30 microns on Leneta hiding rate measurement paper and drying at 70 ° C for 10 minutes.

The adhesion test was applied to Bacota # 8 on polycarbonate specimens of 5cm x 10cm, and dried after 70 ° C x 10 minutes and Ｘ-Cut with cello tape.

Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 urethane 60 60 60 60 60 60 60 WS-500 2 2 2 2 2 2 2 surfynol # 465 0.5 0.5 0.5 0.5 0.5 0.5 0.5 tego # 805 0.3 0.3 0.3 0.3 0.3 0.3 0.3 PA-14 1.5 1.5 1.5 1.5 1.5 1.5 1.5 IPA 5 5 5 5 5 5 5 Water 30.7 30.7 30.7 30.7 30.7 30.7 30.7

The solvent resistance, hardness, gloss, and adhesion test results of the methyl ethyl ketone (MEK) and isopropyl alcohol (IPA) solvents of the coating films prepared in Examples and Comparative Examples are shown in Table 2 below. About solvent resistance: ◎: Very good condition with no change in coating film, ○: Good condition in which Hazy appears finely in coating film, △: Weak condition in which coating film is weak and slightly dissolved, Ｘ: Coating film is soluble, sticky and very turbid Shown in bad state. Regarding the remaining physical properties, it was determined that ◎: very good, ○: good △: normal, and X: poor.

 Item Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2  MEK resistance ○ ◎ ◎ ◎ ○ △ △  IPA resistance ○ ◎ ◎ ◎ ◎ Ｘ △  Hardness ○ ◎ ◎ ◎ ◎ △ ○  Polish ◎ ◎ ◎ ○ ◎ ○ ○  Adhesive ◎ ◎ ◎ ◎ ◎ ○ ○

Example 6 -10 Effect of Diisocyanates

Example 6

Prepare a clean 4L flask, stirrer, mantle, cooling tube, etc., and add 765 g of polycarbonate diol (Ube Carb 100 (molecular weight 1000)), 55.8 g of dimethylol propionic acid, and 285 g of N-methylpyrrolidone as a solvent. After raising the temperature for 1 hour, purge with nitrogen for 1 hour, maintain for 1 hour, dissolve, cool to 75 ° C, add 4,4-dicyclohexylmethane diisocyanate 523g, and add dibutyltin dilaurate with 0.15g 85 A 6 hour terminal NCO prepolymer was prepared at < RTI ID = 0.0 >

Into a 4L beaker equipped with a separate stirrer, 1020 g of ion-exchanged water, 35 g of isopropyl alcohol, and 13 g of triethylamine were added thereto, followed by stirring, followed by strong stirring while adding 825 g of the prepared NCO prepolymer. After fully neutralized for 5 hours, 5 g of ethylene diamine was added, the temperature was raised to 70 ° C., followed by chain extension for 2 hours, and then cooled to room temperature to produce translucent, water-soluble urethane resin having a solid content of about 8.2% of pH 8.2 and a viscosity of 100 cps or less. It was.

Example 7

A water-soluble polyurethane was prepared in the same manner as in Example 6 except that 411 g of noborane diisocyanate was used as the diisocyanate. A water-soluble urethane resin having a translucent, pH 7.8, and a solid content of about 35% with a viscosity of 100 cps or less was prepared.

Comparative Example 3

A water-soluble polyurethane was prepared in the same manner as in Example 6 except that 335 g of hexamethylene diisocyanate was used as the diisocyanate. A water-soluble urethane resin having a translucent pH of about 7.2% with a solid content of pH 7.2 and a viscosity of 100 cps or less was prepared.

Comparative Example 4

A water-soluble polyurethane was prepared in the same manner as in Example 6 except that 445 g of isophorone diisocyanate was used as the diisocyanate. A water-soluble urethane resin having a translucent pH of about 7.5% and a solid content of about 35% with a viscosity of 100 cps or less was prepared.

Comparative Example 5

A water-soluble polyurethane was prepared in the same manner as in Example 6 except that 487 g of tetramethylene diisocyanate was used as the diisocyanate. A milky white water-soluble urethane resin having a solid content of about 35% with a pH of 9.5 and a viscosity of 100 cps or less was prepared.

Solvent resistance test

To the addition of additives and the like in the composition of Table 3 to prepare a water-dispersed polyurethane coating solution, to form a coating film was measured for the overall physical properties including solvent resistance and hardness, gloss, adhesion.

Example 6 Example 7 Comparative Example 3 Comparative Example 4 Comparative Example 5 urethane 60 60 60 60 60 WS-500 2 2 2 2 2 surfynol # 465 0.5 0.5 0.5 0.5 0.5 tego # 805 0.3 0.3 0.3 0.3 0.3 PA-14 1.5 1.5 1.5 1.5 1.5 IPA 5 5 5 5 5 Water 30.7 30.7 30.7 30.7 30.7

Solvent resistance, hardness, gloss, and adhesion test results of the methyl ethyl ketone (MEK) and isopropyl alcohol (IPA) solvents of the coating films prepared in Examples 6, 7 and Comparative Examples 3-5 are shown in Table 2 below. Shown in About solvent resistance: ◎: Very good condition with no change in coating film, ○: Good condition in which Hazy appears finely in coating film, △: Weak condition in which coating film is weak and slightly dissolved, Ｘ: Coating film is soluble, sticky and very turbid Shown in bad state. Regarding the remaining physical properties, it was determined that ◎: very good, ○: good △: normal, and X: poor.

 Item Example 6 Example 7 Comparative Example 3 Comparative Example 4 Comparative Example 5  MEK resistance ◎ ○-◎ △ -X ○-△ △  IPA resistance ◎ ○-◎ △ -X ○-△ △  Hardness ◎ ◎ △ -X ◎ △  Polish ◎ ◎ △ ◎ △

It will be appreciated by those skilled in the art that the present invention has been described in detail as above, but that the above examples are not intended to limit the invention but merely to illustrate. In addition, various modifications may be made without departing from the spirit and scope of the invention, and such modifications will be included in the claims set forth below.

According to the present invention, a water-dispersible polyurethane having strong solvent resistance is provided. The water-dispersed polyurethane according to the present invention has a strong solvent resistance and can be used in cell phone bases and top coatings, surface coatings for steel sheets, automotive coatings, film hard coatings, unlike water-soluble polyurethane water dispersions used in the prior art.

Claims (6)

Manufactured from NCO-terminated polyurethane prepolymers prepared by reacting a polyol containing polycarbonate diol as a main component, an organic diisocyanate containing noborane diisocyanate, dicyclohexyl methane diisocyanate or a mixture thereof and a diol having hydrophilicity , Wherein the polyol comprises a triol, The triol has an equivalent ratio of organic isocyanate and triol of 5: 1 to 30: 1, and The polyurethane prepolymer has a terminal NCO% of 1 to 8% Solvent-resistant water-dispersed polyurethane dispersion, characterized in that. The solvent-resistant aqueous dispersion polyurethane dispersion according to claim 1, wherein the polycarbonate diol has a molecular weight of 600-6000. delete delete delete delete