KR20230082811A - Producing method of high water-resistant polyurethane coating resin recycled a spandex and coating textile adapted the same - Google Patents

Abstract

The present invention relates to a method for manufacturing a highly water-resistant polyurethane coating resin using recycled spandex and a coating fabric using the same. The method comprises the steps of: performing primary depolymerization of spandex; preparing a spandex depolymerization resin (I); preparing a prepolymer (II); adding the spandex depolymerization resin (I) to the prepared prepolymer (II) and stirring the same; and adjusting the reaction by adding 0.2 to 3 wt% of a chain extender (i) thereto. The coating fabric of the present invention has excellent compatibility and excellent processability.

Description

Manufacturing method of polyurethane coating resin with high water resistance by recycling spandex and coating fabric using the same

The present invention relates to a method for producing a polyurethane coating resin having high water resistance by recycling spandex and a coated fabric to which the same is applied, and more particularly, spandex having stable viscosity characteristics by depolymerizing waste spandex yarn through an effective chemical method and neutralizing it with NaOH and an acid. It relates to a method for producing a highly water-resistant polyurethane coating resin having excellent durability and coating properties and good processability by obtaining an eco-friendly polyurethane resin after preparing a depolymerized resin, and a coated fabric to which the same is applied.

In general, coated fabrics are materials used for various purposes such as waterproof, windproof, antifouling, water repellent, and moisture permeability. Recently, with the development of the sports and leisure industry, the demand for functional materials for sports and outdoor use is rapidly increasing. there is.

Polyurethane coating resin, which is widely used in the coating fabric, is obtained by reacting various diols and isocyanate-based raw materials, so it is tough, elastic, flexible, tactile, mechanical strength, film forming ability, chemical resistance, adhesive strength, etc. compared to other plastic materials. have a distinction Such polyurethane can be adjusted to various properties and physical properties according to the combination ratio of raw materials, and is also used for electrical insulators, structural materials, foam insulation materials, foam cushions, elastic fibers, and coating materials.

On the other hand, spandex is a general term for highly elastic fibers containing polyurethane as a main component, and is produced into multi- or monofilament yarns, tapes, etc. by dry or wet spinning depending on the type of fiber. Although the manufacturing method of such spandex differs depending on the spinning method, it is generally a urethane-based elastic fiber produced by polymerization of monomeric diol and isocyanate. It started production as a trademark, and it has elongation of 500 ~ 700% or more and excellent resilience, and has excellent dyeability, heat resistance and chemical resistance, so it is used in various ways for clothing such as stockings and swimwear.

As the spandex is used in various fields due to its excellent elastic recovery, many deaths occur during the manufacturing process. In the process of making the product, if the thickness (denier) is defective or if a defective product is produced in the process of winding the spandex, the entire amount will be treated as waste yarn, and the remaining residue after the fabric is made by the company consuming the spandex is also treated as waste yarn. . This spandex waste yarn comes out in the form of a thread ball.

Since this spandex death is determined by the appearance of the spandex rather than physical or chemical damage, such as contamination or condition of the exterior, there is no degradation of its physical properties, so the potential utilization value is high. However, in general, the range of recycling is widened only when it is melted by heat or easily dissolved in a solvent. However, since spandex has limited re-melting and re-melting by solvent due to the cross-linking reaction in spandex, it is difficult to efficiently recycle. It is used for simple purposes such as filling.

In the present invention, waste yarn generated in the production process of spandex fiber is recycled to produce a polyurethane resin for fiber coating having more excellent physical properties in an environmentally friendly manner, and it is intended to be applied to fabric coating.

In order to recycle the polyurethane resin related to the present invention, Korean Patent No. 10-0627209 1) uses 15 to 100 parts by weight of glycol and 0.1 to 10 parts by weight of a depolymerization catalyst based on 100 parts by weight of pulverized waste rigid polyurethane foam powder. a depolymerization reaction step of reacting at 120 to 250 ° C. for 30 minutes to 15 hours; 2) an esterification reaction step in which 10 to 40 parts by weight of an anhydride compound and 0.001 to 10 parts by weight of a polymerization catalyst are added to the depolymerized regenerated polyol and subjected to a high-pressure vacuum reaction at 150 to 230° C. for 3 to 12 hours; 3) separating impurities using a filter; As a method for producing a regenerated polyol from which aromatic amine and residual glycol are removed, the patent relates to a technology for recycling waste polyurethane foam used as a heat insulating material and a cold insulating material into polyol through a chemical regeneration method.

In addition, Patent No. 10-0974450 discloses the steps of recovering the polyurethane residue remaining on the bobbin and cutting and crushing to form polyurethane residue powder; 10 to 50% by weight of the polyurethane residue powder, 50 to 90% by weight of a residue dissolving solvent using dimethylacetamide alone or a residue dissolving solvent obtained by mixing dimethylformamide and/or methylethylketone with dimethylacetamide mixing to form a polyurethane residue solution; forming a regenerated polyurethane resin by heating the polyurethane residue solution at 100 to 150° C. in a water-blocking state; And a method for producing a regenerated polyurethane resin for artificial leather comprising the step of obtaining the regenerated polyurethane resin by cooling it is disclosed.

And Patent No. 10-1785245 relates to a method for manufacturing a PU elastic sheet using waste resin and waste fiber yarn generated in the spandex fiber manufacturing process and a PU elastic sheet manufactured in the manufacturing method, which is generated in the spandex fiber production process. A pulverized product obtained by pulverizing waste fiber yarns generated in the spinning process using polyurethane prepolymer and chain extender as a binder and spandex resin oligomer and polymer waste resin terminated by a chain extender. A technique for producing various high-quality PU elastic sheets by mixing with a recycled mixed material for a sheet and forming the mixed material through a sheet manufacturing apparatus including a dry or wet process is disclosed.

Korean Registered Patent Publication No. 10-0627209 (Date of Publication: September 25, 2006) Republic of Korea Patent Registration No. 10-0974450 (Announcement Date: August 06, 2010) Republic of Korea Patent Registration No. 10-1785245 (notice date October 13, 2017)

An object of the present invention is to depolymerize waste spandex yarn using glycol or amine, which is an effective chemical recycling method, and neutralize it with NaOH and acid to eco-friendlyly prepare a spandex depolymerization resin having stable viscosity characteristics, and then to polyether polyol and polyester. Polyol and diisocyanate are added to a prepolymer prepared by mixing and reacting in an appropriate ratio, stirred to prepare a resin with stable properties, and additionally added a chain extender to adjust the urethane chain reaction, thereby maintaining durability and coating while having stable storage characteristics and processability. It is to provide a method for producing a polyurethane coating resin having high water resistance by recycling spandex having excellent properties and a coated fabric to which the same is applied.

The method for producing a highly water-resistant polyurethane coating resin by recycling spandex according to the present invention, after mixing 10 to 20% by weight of spandex waste yarn (a) and 20 to 40% by weight of a solvent (b), glycol and / or amine ( c) firstly depolymerizing spandex by adding 1 to 12% by weight; In order to control the decomposition characteristics of the first depolymerized spandex, 0.1 to 5% by weight of NaOH (d) is mixed and stirred to adjust the second depolymerization and decomposition degree, and then neutralized with an acid to prepare a spandex depolymerization resin (I); Slowly add 5 to 20% by weight of a polyether polyol (e) with an average molecular weight of 600 to 2500, 3 to 12% by weight of a polyester polyol (f) with an average molecular weight of 1000 to 4000, and 20 to 40% by weight of a solvent (g). Then, preparing a prepolymer (II) by reacting isocyanate (h) at a ratio of 1.5 to 8% by weight; Adding spandex depolymerization resin (I) to the prepared prepolymer (II) and stirring; Here, adjusting the reaction by adding 0.2 to 3% by weight of a chain extender (i); It is characterized by consisting of.

According to a preferred embodiment of the present invention, the glycol and / or amine (c) is ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, And using at least one selected from ethylenediamine, dibutylamine, dicyclohexylamine, triethylenetetramine, and ethyldiisopropylamine, The concentration of NaOH (d) for controlling the decomposition characteristics of the first depolymerized spandex is 2 to 12%, and the chain extender (i) is monoethylene glycol, 1,3-propanediol (1 ,3-Propanediol), 1,4-butanediol (1,4-Butanediol), diethylene glycol, diol glycol selected from 1,6-hexanediol (1,6-Hexanediol), and ethylenediamine Amine chain extender selected from (Ethylendiamine), 4,4-Methylene bis(cyclohexylamine), Hydrazine, and 1,3-Butadiene At least one selected from among them is used.

Therefore, the spandex depolymerization resin (I) is included in an amount of 25 to 60% by weight based on the total weight of the solid content of the polyurethane coating resin, and the finally prepared polyurethane coating resin has a solid content of 30 to 50% by weight and a viscosity of 70,000 to 105,000 It has physical properties in the cP range.

In addition, the coated fabric of the present invention is diluted with 20 to 70 parts by weight of a solvent based on 100 parts by weight of a highly water-resistant polyurethane coating resin obtained by recycling the spandex produced by the above manufacturing method, the viscosity is adjusted to 8,000 to 20,000 cP, and then crosslinking agent 2 ~ 12 parts by weight is added, applied to the textile fabric in an amount of 5 ~ 50 g / ㎡, and then cured at a temperature of 100 ~ 160 ℃, water resistance of the textile fabric to which the highly water-resistant polyurethane coating resin recycled from the spandex is applied is 7,000 to 10,000 mmH ₂ O, and the water resistance after washing 10 times is 1,000 to 3,000 mmH ₂ O.

Polyurethane coating resin with high water resistance recycled spandex manufactured by the manufacturing method of the present invention is depolymerized using glycol or amine, which is an effective chemical recycling method, and neutralized with NaOH and acid to obtain a spandex depolymerized resin having stable viscosity characteristics. Due to its use, it has excellent compatibility and has excellent processability by minimizing the increase in viscosity over time, and thus reacts by adding a chain extender while stirring with a prepolymer prepared by mixing and reacting polyether polyol and polyester polyol in an appropriate ratio When it is coated on the fiber fabric by adjusting, there is an effect of excellent durability and coating property and good processability.

Hereinafter, a method for manufacturing a highly water-resistant polyurethane coating resin by recycling spandex according to the present invention and a coated fabric using the same will be described, which can be easily performed by a person skilled in the art to which the present invention belongs. It is intended to illustrate as much as possible, but does not mean that the technical spirit and scope of the present invention are thereby limited.

In general, polyurethane resin is a resin produced based on a urethane bond formed by the reaction of an isocyanate group (-NCO) and a hydroxyl group (-OH) in a polymer, and its raw materials are polyol, isocyanate, chain extender, etc. It is usually prepared by solution polymerization by adding various solvents. The characteristics of this polyurethane resin are that it has excellent film strength and adhesive strength, so it is possible to manufacture a thin coating film, and the elasticity of the coating film is rich, so it is soft to the touch and can be manufactured as a porous film, which can impart moisture permeability and breathability. It also has excellent cold resistance, and because it is processed without using plasticizers, there are few workability problems caused by plasticizers.

Spandex, the main component of which is polyurethane, is a material that is used in various fields due to its excellent elastic recovery. Research to recycle urethane as a material is being carried out from various angles.

Materials such as the urethane have to be physically crushed, melted by heat, or easily dissolved in a solvent to widen the range of recycling. However, spandex is difficult to efficiently recycle because re-melting and re-melting due to solvents are limited due to the crosslinking reaction in spandex. And, when simply recycling in a conventional way, it is difficult to store and process due to the gradually increasing viscosity.

In order to solve the above problems, the manufacturing method of high water resistance polyurethane coating resin by recycling spandex of the present invention is to mix 10 to 20% by weight of spandex waste sand (a) and 20 to 40% by weight of solvent (b) , firstly depolymerizing spandex by adding 1 to 12% by weight of glycol and/or amine (c); In order to control the decomposition characteristics of the first depolymerized spandex, 0.1 to 5% by weight of NaOH (d) is mixed and stirred to adjust the second depolymerization and decomposition degree, and then neutralized with an acid to prepare a spandex depolymerization resin (I); Slowly add 5 to 20% by weight of a polyether polyol (e) with an average molecular weight of 600 to 2500, 3 to 12% by weight of a polyester polyol (f) with an average molecular weight of 1000 to 4000, and 20 to 40% by weight of a solvent (g). Then, preparing a prepolymer (II) by reacting isocyanate (h) at a ratio of 1.5 to 8% by weight; Adding spandex depolymerization resin (I) to the prepared prepolymer (II) and stirring; Here, adjusting the reaction by adding 0.2 to 3% by weight of a chain extender (i); made up of

Spandex waste yarn (a) used in the present invention is a length that is defective in thickness (denier) in the process of making spandex, or in the process of winding spandex, resulting in a defective product, or remaining after making fabric, or treated as waste due to external contamination in the manufacturing process is a spandex yarn of tens of centimeters to hundreds of meters, usually in the form of a ball of yarn.

In addition, spandex fibers and resins, which are the main raw materials in the manufacturing process of spandex fibers, are first synthesized as prepolymers by using monomeric MDI (Monomeric Methylene Diisocyanate) in PTMG (Polytetramethylene glycol) polyol having a polyether structure, followed by chain extension It is prepared by making a spinning solution using zero diamine-based raw materials and other solvents and additives and spinning it. In the present invention, it is possible to use a spandex material manufactured with the above structure of PTMG-MDI-Diamine.

In the first depolymerization of spandex, 10 to 20% by weight of spandex waste sand (a) and 20 to 40% by weight of solvent (b) are mixed, and then 1 to 12% by weight of glycol or amine (c) is added. As a, before depolymerization, foreign substances are removed from the spandex waste bundle, and the spandex waste bundle from which the foreign matter is removed is immersed in ethyl alcohol to remove impurities, washed with stirring, and then dried at a temperature of 80 ° C. for 2 hours to remove moisture and impurities in the spandex. Removed. The dried spandex waste yarn is stirred for 2 to 24 hours in a stirrer at 80 to 200 ° C., which is a temperature at which spandex melts, together with solvent (b) and glycol or amine for depolymerization (c) to depolymerize while the chain of spandex waste sand is cut. It will be.

As the solvent (b), it is necessary to use an inert organic solvent that can dissolve spandex, is stable at high temperatures, and does not cause any problems during subsequent fabric processing, and must be able to stably maintain the urethane reaction that proceeds later. As a specific example of the organic solvent, dimethylformamide, dimethylacetamide, toluene, methyl ethyl ketone, isopropanol, or a mixture of two or more selected from these is used in excess of the amount of spandex waste yarn (a) to depolymerize, among which Dimethylformamide was studied as the most suitable.

As the glycol and/or amine (c) for depolymerization, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol or ethylenediamine , Dibutylamine, dicyclohexylamine, triethylenetetramine, ethyldiisopropylamine, etc. can be used, among which amine suitable for synthesis of urethane is selected Therefore, it was confirmed that dibutylamine is most advantageous in the present invention.

However, in the case of a solution in which spandex is depolymerized using glycol or amine (c) as described above, it is necessary to maintain a relatively uniform viscosity in order to apply it to an actual urethane reaction, but even if the depolymerization solution has flowability, the viscosity after It rises gradually, and after 15 days, a phenomenon of gelation occurs.

In the present invention, in the step of preparing the spandex depolymerization resin (I) to prevent this phenomenon, in order to control the decomposition characteristics of the first depolymerized spandex, 0.1 to 5% by weight of NaOH (d) is mixed and stirred to perform the second depolymerization and After adjusting the degree of decomposition, it is neutralized with acid. At this time, NaOH (d) solution having a concentration of 2 to 12% is applied and the depolymerized solution is pretreated at a temperature of 150 ℃, and then pH titrated with phosphoric acid (H ₃ PO ₄ ). Neutralization was performed to prepare an eco-friendly spandex depolymerization resin (I).

However, when producing a polyurethane resin for fabric coating using the above-prepared spandex depolymerization resin (I), it can be simply applied by a one-shot method at the beginning of the reaction, but when applied by one-shot, the viscosity of the resin rapidly rises A phenomenon of solidification in a semi-gelled state is observed. Accordingly, in the present invention, a prepolymer (II) obtained by reacting polyol and isocyanate is first prepared, and then a spandex depolymerization resin (I) is mixed and treated to secure stability and a polyurethane resin is prepared through a chain extension reaction, so that during or reaction It was confirmed that stable flowability and viscosity can be maintained even after

Accordingly, the step of preparing the prepolymer (II) includes 5 to 20% by weight of a polyether polyol (e) having an average molecular weight of 600 to 2500 and 3 to 12% by weight of a polyester polyol (f) having an average molecular weight of 1000 to 4000 and After slowly adding 20 to 40% by weight of solvent (g), the reaction was performed at a rate of 1.5 to 8% by weight of isocyanate (h), and spandex depolymerization resin (I) was added to the prepared prepolymer (II) to stir After going through the steps, 0.2 to 3% by weight of a chain extender (i) was added thereto to adjust the reaction, thereby preparing a polyurethane coating resin having high water resistance recycled spandex.

The polyether polyol (e) is polytetramethylene glycol, monodicarbinol terminated polydimethylsiloxane polyol, polypropylene glycol, polycarbonate diol ), trimethylol propane, and one or more types of polyether polyol derived therefrom can be used, and most preferably polytetramethylene glycol (PTMG) with an average molecular weight in the range of 600 to 2500 is applied. It was investigated that the manufactured product exhibited excellent tactile feel and compatibility, and a good viscosity range.

In addition, the polyester polyol (f) is a type of polyol in which ester groups (-COO-) are repeatedly bonded to the molecular structure, and has a weight average molecular weight of 1000 to 1000 in consideration of characteristics such as mechanical properties, film forming ability, and adhesive strength. The use of polyester polyols in the range of 4000 is possible. Specifically, 2,2-dimethyl-1,3-propandiol (2,2-dimetyl-1,3-propandiol), 1,4-butanediol (1,4-butandiol) At least one diol selected from among , ethylene glycol and 1,6-hexane diol, adipic acid, isophthalic acid, terephthalic acid, and phthalic anhydride A polyester polyol obtained by reacting a phthalic anhydride with polycaprolactone can be used, and polyesters derived from hydroxycarboxylic acids or corresponding lactones or lactides or from dicarboxylic acids and diols are particularly preferred. , In the present invention, it is most preferable to use polycarprolactone having an average molecular weight of 1,000 to 3,000.

The solvent (g) used in the step of preparing the prepolymer (II) is the same organic solvent as the solvent (b) used in depolymerizing the spandex waste yarn (a), which is generally used in the synthesis of urethane Dimethylformamide, dimethylacetamide, toluene, methyl ethyl ketone, and isopropane may be used alone or in combination, and dimethylformamide is most suitable.

And the diisocyanate (h) used in the present invention is methylene diphenyl diisocyanate, toluene diisocyanate, 4,4'-methylene dicyclohexyl diisocyanate (H ₁₂ MDI), isophorone It is possible to use at least one isocyanate selected from among diisocyanate (Isophorone diisocyanate), tetramethyl xylene diisocyanate, and hexamethylene diisocyanate, and most preferably, compatibility with spandex It is suitable to use good quality Methylene diphenyl diisocyanate.

The chain extender (i) is used to adjust the molecular weight after applying the spandex depolymerization resin (I) to the prepolymer (II), and is composed of monoethylene glycol, 1,3-propanediol (1,3- propanediol), 1,4-butanediol, diethylene glycol, diol-based glycol selected from 1,6-hexanediol, and ethylenediamine , 4,4-methylene biscyclohexylamine (4,4-Methylene bis (cyclohexylamine)), hydrazine (Hydrazine), 1,3-butadiene (1,3-Butadiene) selected from among amine chain extenders selected from One or more types can be used, and in particular, in order to impart a structure similar to spandex and improve compatibility, it is recommended to use an amine-based chain extender selected from ethylenediamine and 4,4-methylene biscyclohexylamine, which has excellent coating film properties. Polyurethane resins can be prepared.

Therefore, the spandex depolymerization resin (I) is included in an amount of 25 to 60% by weight based on the total weight of the solid content of the polyurethane coating resin, and the finally prepared polyurethane coating resin has a solid content of 30 to 50% by weight and a viscosity of 70,000 to 105,000 Characterized in that it is cP.

In addition, the manufacturing method of the coated fabric according to the present invention is diluted with 20 to 70 parts by weight of a solvent based on 100 parts by weight of a highly water-resistant polyurethane coating resin recycled from the spandex produced as described above to adjust the viscosity to 8,000 to 20,000 cP After that, 2 to 12 parts by weight of the crosslinking agent is added, applied to the textile fabric in an amount of 5 to 50 g/m2, and then cured at a temperature of 100 to 160 ° C. As a result, the highly water-resistant polyurethane coating resin recycled from the spandex The water pressure of the textile fabric to which is applied is 7,000 to 10,000 mmH ₂ O, and the water pressure after washing 10 times exhibits characteristics of about 1,000 to 3,000 mmH ₂ O.

As described above, methylformamide, dimethylacetamide, toluene, and methylethylketone can be used as solvents used to coat the finally prepared polyurethane coating resin on textile fabrics, and as a crosslinking agent, a melamine-based crosslinking agent NCO type A cross-linking agent can be used. In addition, various additives such as thermal antioxidants, photooxidation inhibitors, and UV additives can be used to suppress the denaturation and oxidation reactions of polyurethane resin. Therefore, a detailed description thereof is omitted.

Hereinafter, we will look at an embodiment in which a highly water-resistant polyurethane coating resin recycled from spandex manufactured by the present invention is tested, but a person having ordinary knowledge in the technical field to which the present invention belongs can easily carry out The present invention is explained through a preferred embodiment.

[Examples 1 to 3 / Comparative Examples 1 and 2]

Preparation of spandex depolymerization resin (I)

In a nitrogen atmosphere in a 1 liter three-necked reflux reactor, the spandex waste ball was immersed in 100 g of ethyl alcohol to remove impurities, washed with stirring, and then dried at a temperature of 80 ° C. for 2 hours to remove moisture and impurities in the spandex. The dried spandex waste sand bundle is heated together with DMF and DBA to a temperature of 120 to 200 ° C., which is a temperature at which spandex melts, and stirred in a stirrer for 2 to 24 hours to depolymerize the spandex waste sand. A 5% NaOH solution was applied to the depolymerized solution, stirred at 150° C. for 2 hours, and phosphoric acid was added dropwise to neutralize the pH titration to prepare a spandex depolymerization resin (I).

Preparation of polyurethane coating resin

70 g of PTMG and 40 g of PCL were mixed with 100 g of DMF in a 1 liter 3-necked reflux reactor under a nitrogen atmosphere and stirred. The reaction was carried out for ~ 4 hours to prepare a prepolymer (II). Spandex depolymerization resin (I) was added to the prepared prepolymer (II) and stirred for 1 to 2 hours to stabilize. To the prepared prepolymer mixture, 5 g of EDA was added dropwise while checking the NCO% and viscosity to terminate the reaction, and a solvent and an antioxidant were mixed and stirred.

In the same manner as the above process, the preparation of polyurethane coating resins with different formulations of each component was performed with the composition shown in [Table 1] below (unit: g).

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Spandex waste (a) 205 120 330 190 140 solvent (b) 300 176 483 278 205 Amine (c) 41 24 66 38 0 NaOH(d) 9 9 9 0 0 polyether polyol (e) 70 70 70 70 70 Polyester polyol (f) 40 40 40 40 40 solvent (g) 300 300 340 300 220 Diisocyanate (h) 30 30 33 30 24 chain extender (i) 5 5 5 5 5

[Experimental example]

For the polyurethane coating resins prepared according to Examples 1 to 3 and Comparative Examples 1 and 2, the viscosity, tensile strength, water resistance, and water resistance after washing were measured in the following manner, and the results are shown in Table 2 below. shown in

○ Viscosity: The viscosity was measured using a Brookfield viscometer according to the KSM 3705 method.

○ Viscosity after 15 days: The viscosity of the resin stored for 15 days after completion of the reaction was measured using a Brookfield viscometer according to the KSM 3705 method.

○ Tensile strength: The strength of the prepared specimen was measured according to the ASTM 882 method to prepare a film with a thickness of 30㎛ at a temperature of 120 ℃ of the prepared resin.

○ Water resistance: Water resistance was measured according to ISO 811.

○ Water resistance after washing: Measured according to ISO 811 after washing 10 times using a tumble dryer washing machine.

○ Touch: According to the conditions of the polyester fabric, urethane resin was coated, and 5 experts were selected to measure the average value of the touch (◎: very good, ○: good, △: normal, ×: bad).

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Spandex waste yarn content 51% 40% 60% 51% 50% Viscosity (cP) 80,000 75,000 101,000 83,000 160,000 Viscosity after 15 days (cP) 83,000 76,000 140,000 210,000 gel Tensile strength (MP) 13 10 15 13 - Water pressure (mmH ₂ O) 7,000 8,000 7,000 7,000 - Water resistance after washing 10 times (mmH ₂ O) 1,000 1,800 1,000 1,000 - touch ◎ ◎ ○ ○ -

As shown in [Table 2], comparing the experimental results of the reactive urethane adhesives prepared according to Examples 1 to 3 and Comparative Examples 1 and 2, as the ratio of depolymerized spandex waste yarn increases, the viscosity and tensile strength of Although a rise was confirmed, it was confirmed that there was no significant change in the water pressure. It was confirmed that the storage stability (viscosity after 15 days) rapidly decreased when the spandex waste sand was not treated with NaOH and amine during depolymerization. From the above experimental results, it can be confirmed that Example 1 manufactured according to the present invention has relatively the best water pressure resistance and storage stability.

Therefore, the highly water-resistant polyurethane coating resin recycled spandex according to the present invention can be substituted, modified, and changed in various ways without departing from the technical idea of the present invention. It can be used in various uses and forms as an eco-friendly material that can be applied in the form of a film or coated on various clothing, automobiles, building materials, etc. as well as surface processing of various exposed textile materials.

Claims (7)

After mixing 10 to 20% by weight of spandex waste sand (a) and 20 to 40% by weight of solvent (b), 1 to 12% by weight of glycol and/or amine (c) is added to first depolymerize spandex;
In order to control the decomposition characteristics of the first depolymerized spandex, 0.1 to 5% by weight of NaOH (d) is mixed and stirred to adjust the second depolymerization and decomposition degree, and then neutralized with an acid to prepare a spandex depolymerization resin (I);
Slowly add 5 to 20% by weight of a polyether polyol (e) with an average molecular weight of 600 to 2500, 3 to 12% by weight of a polyester polyol (f) with an average molecular weight of 1000 to 4000, and 20 to 40% by weight of a solvent (g). Then, preparing a prepolymer (II) by reacting isocyanate (h) at a ratio of 1.5 to 8% by weight;
Adding spandex depolymerization resin (I) to the prepared prepolymer (II) and stirring;
Here, adjusting the reaction by adding 0.2 to 3% by weight of a chain extender (i);
Method for producing a highly water-resistant polyurethane coating resin recycled spandex, characterized in that consisting of. According to claim 1,
The glycol and/or amine (c) is ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, and ethylenediamine, dibutyl High water resistance poly recycled spandex characterized by using at least one selected from amine (Dibutylamine), dicyclohexylamine, triethylenetetramine, and ethyldiisopropylamine Manufacturing method of urethane coating resin. According to claim 1,
Method for producing a highly water-resistant polyurethane coating resin recycling spandex, characterized in that the concentration of NaOH (d) for controlling the decomposition characteristics of the first depolymerized spandex is 2 to 12%. According to claim 1,
The chain extender (i) is monoethylene glycol, 1,3-propanediol, 1,4-butanediol, diethylene glycol , Diol-based glycol selected from 1,6-hexanediol, ethylenediamine, 4,4-methylene bis(cyclohexylamine), hydrazine (Hydrazine), 1,3-butadiene (1,3-Butadiene), characterized in that using at least one selected from the amine-based chain extender selected from the spandex manufacturing method of highly water-resistant polyurethane coating resin . According to claim 1,
The spandex depolymerization resin (I) is included in an amount of 25 to 60% by weight based on the total weight of the solid content of the polyurethane coating resin, and the finally prepared polyurethane coating resin has a solid content of 30 to 50% by weight and a viscosity of 70,000 to 105,000 cP Method for producing a highly water-resistant polyurethane coating resin recycled spandex, characterized in that. After adjusting the viscosity to 8,000 to 20,000 cP by diluting the spandex produced by the manufacturing method of any one of claims 1 to 5 with 20 to 70 parts by weight of a solvent based on 100 parts by weight of the highly water-resistant polyurethane coating resin, , 2 to 12 parts by weight of a crosslinking agent, applied to a fiber fabric in an amount of 5 to 50 g / m 2, and then cured at a temperature of 100 to 160 ° C. Coated fabric. According to claim 6,
The water pressure of the textile fabric to which the highly water-resistant polyurethane coating resin recycled from the spandex is applied is 7,000 to 10,000 mmH ₂ O, and the water pressure after washing 10 times is 1,000 to 3,000 mmH ₂ O Coated fabric, characterized in that.