Polyurethane hot melt adhesive for high-elasticity textile fabric with soft hand feeling and preparation method of polyurethane hot melt adhesive

Abstract

The invention belongs to the technical field of textile adhesives, and provides a polyurethane hot melt adhesive for a soft-hand-feeling high-elasticity textile and a preparation method of the polyurethane hot melt adhesive, and the hot melt adhesive product comprises a reactive polyurethane hot melt adhesive prepolymer and a polymeric elastomer premix, the hot melt adhesive is prepared from the following components in percentage by weight: 20 to 70 percent of reactive polyurethane hot melt adhesive prepolymer, 20 to 75 percent of high-molecular elastomer premix, 3 to 20 percent of compatilizer, 0.1 to 0.5 percent of defoaming agent, 0.01 to 0.1 percent of catalyst, 0.1 to 0.5 percent of antioxidant and 1 to 2 percent of dewatering agent, when the polyurethane hot melt adhesive is used for laminating high-elasticity cloth such as spandex cloth, the polyurethane hot melt adhesive shows good applicability, the rebound rate of laminated cloth reaches 99.3% or above, and the laminated cloth is soft in hand feeling and smooth in appearance.

Description

Technical Field

[0001] The invention belongs to the technical field of textile adhesives, and particularly relates to a polyurethane hot melt adhesive for soft and highly elastic textiles and a preparation method thereof. Technical Background

[0002] PUR hot melt adhesive is made from a prepolymer with -NCO end groups, supplemented with various polymer fillers, tackifying resins, plasticizers, and various additives that do not react with -NCO groups. After heating, the colloid melts and is applied to the surface of the substrate by spraying, rolling, or scraping. After physical cooling, it generates initial adhesion, securing the adhered object. It then undergoes a cross-linking reaction with moisture in the air to form a polymer with very strong cohesion. At a molecular level, PUR hot melt adhesive is based on isocyanates, polyethers, and polyester polyols. Under certain conditions, a prepolymer with a certain molecular weight is synthesized. This prepolymer is composed of hard segments such as urethane and urea bonds, and soft segments such as alkyl groups. This structure gives the polyurethane material excellent elasticity and toughness. It also offers advantages such as impact resistance, good flexibility, low-temperature resistance, solvent resistance, fatigue resistance, wear resistance, and adjustable hardness. Therefore, it has been widely used in various application fields.

[0003] Polyurethane adhesives are commonly used in the textile industry due to their good bonding strength, excellent softness, and wash / dry cleaning resistance. With the development of the textile industry and the increasing demand for environmental protection, the adhesives used have gradually changed from solvent-based polyurethane adhesives to water-based polyurethane adhesives. At present, the textile industry needs higher bonding efficiency and the trend of using adhesives to replace stitching in textiles such as laminated fabrics. Therefore, the demand for adhesives tends to use reactive polyurethane hot melt adhesives. The high-elastic laminated fabrics made of existing polyurethane hot melt adhesives are limited by the elasticity, softness, and strength of the hot melt adhesives. They have shortcomings such as poor rebound after stretching, resulting in unevenness and stiffness of the fabric. They cannot meet the market requirements for the aesthetics, comfort, and processing speed of laminated fabrics using polyurethane hot melt adhesives. Therefore, new creative requirements are put forward for the elasticity and feel of reactive polyurethane hot melt adhesives for textile applications. Summary of the Invention

[0004] The purpose of the present invention is to provide a polyurethane hot melt adhesive for highly elastic textiles with a soft hand feel and a preparation method thereof, so as to solve the problem of replacing adhesive materials for laminating elastic bands and other parts under the current trend of de-needling of textiles.

[0005] The technical solutions of the present invention are as follows: A polyurethane hot melt adhesive for highly elastic textiles with a soft hand comprises a reactive polyurethane hot melt adhesive prepolymer and a polymer elastomer premix. The adhesive comprises the following components in weight percentage, calculated on a resin basis: 20-70% reactive polyurethane hot melt adhesive prepolymer, 20-75% polymer elastomer premix, 3-20% compatibilizer, 0.1-0.5% defoamer, 0.01-0.1% catalyst, 0.1-0.5% antioxidant, and 1-2% water scavenger; the compatibilizer is a maleic anhydride grafted polymer; and the raw materials for preparing the reactive polyurethane hot melt adhesive prepolymer comprise aliphatic isocyanate, polyester polyol, polyether diol, tri- or higher-functionality polyether polyol, and di-terminal hydroxy silicone oil.

[0006] Preferably, a polyurethane hot melt adhesive for highly elastic textiles with a soft hand feel is provided, wherein the reactive polyurethane hot melt adhesive prepolymer is prepared from the following components in weight percentage: polyether polyol, double-end alcohol hydroxy silicone oil, polyester polyol, catalyst, and isocyanate in a weight ratio of 10-50%: 10-40%: 10-40%: 0.01-0.1%: 10-30%.

[0007] Preferably, a polyurethane hot melt adhesive for highly elastic textiles with a soft hand feel, wherein the polymer elastomer premix is ​​made of the following components in the following weight percentages: tackifying resin: plasticizer: polymer elastomer: antioxidant (35~70%): (5~20%): (15~55%): (0.1~0.5%).

[0008] Preferably, a polyurethane hot melt adhesive for highly elastic textiles with a soft hand feel is provided, wherein the polymer elastomer is a mixture of one or more of SBS (styrene-butadiene-styrene block copolymer), SIS (styrene-isoprene-styrene block copolymer), thermoplastic polyurethane elastomer, EVA (ethylene-vinyl acetate copolymer), natural rubber, and silicone rubber; the tackifying resin is a mixture of one or more of petroleum resin, hydrogenated petroleum resin, monomer resin, terpene resin, and rosin resin; the plasticizer is a mixture of one or more of aliphatic diacids, cyclohexane oil, and paraffin; and the antioxidant is a mixture of one or more of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and octadecyl 3,5-di-tert-butyl-4-hydroxyphenylpropionate.

[0009] Preferably, a polyurethane hot melt adhesive for soft, highly elastic textiles comprises polyoxypropylene polyol and polytetramethylene glycol, each having a molecular weight of 650-5000, a functionality of 2 and / or 3, and a moisture content of 500 ppm or less. Furthermore, the polyether polyols are all polyoxypropylene polyols, each selected from a mixture of one or more of a molecular weight of 2000 and a functionality of 2, a molecular weight of 700 and a functionality of 3, and a molecular weight of 5000 and a functionality of 3, all with a moisture content of 500 ppm or less.

[0010] Preferably, a polyurethane hot melt adhesive for soft and highly elastic textiles is provided, wherein the molecular weight of the double-ended hydroxy silicone oil is 1000-2500 and the active content is >98%; further preferably, the molecular weight is 2000.

[0011] Preferably, a polyurethane hot melt adhesive for soft and highly elastic textiles, wherein the polyester polyol is selected from one or more of polyethylene adipate glycol, polybutylene adipate-1,4-diol, and polyhexane adipate-1,6-diol, with a molecular weight of 1000-3000, a functionality of 2, and a moisture content of ≤500ppm.

[0012] Preferably, a polyurethane hot melt adhesive for highly elastic textiles with a soft hand feel is provided, wherein the synthesis catalyst used in the reactive polyurethane hot melt adhesive prepolymer is one or more of dibutyltin dilaurate, stannous octoate, and bismuth neodecanoate.

[0013] Preferably, a polyurethane hot melt adhesive for highly elastic textiles with a soft hand feel, wherein the isocyanate is a mixture of one or more of HMDI (chemical name 4,4'-dicyclohexylmethane diisocyanate), IPDI (chemical name isophorone diisocyanate), HXDI (chemical name cyclohexane dimethylene diisocyanate), HDI (chemical name hexamethylene diisocyanate), and CHDI (chemical name 1,4-cyclohexyl diisocyanate).

[0014] Preferably, a polyurethane hot melt adhesive for highly elastic textiles with a soft hand feel is provided, wherein the compatibilizer is a maleic anhydride grafted polymer, the defoamer is a non-silicone polymer BYK-555, the catalyst is Jeffcat DMDEE (bis(2,2-morpholinoethyl) ether), the antioxidant is 1076 (β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate), and the water scavenger is triethyl orthoformate.

[0015] A method for preparing a polyurethane hot melt adhesive for soft and highly elastic textiles is also provided, which is characterized by the following steps: Step 1: First, heat the three-necked flask to about 160°C in an oil bath, then slowly add the formulated amount of plasticizer and tackifying resin, and at the same time, add a small amount of antioxidant. After high-speed dispersion for 30 minutes, add the polymer elastomer, and continue high-speed dispersion while removing water under a vacuum of more than -0.098MPa for more than 2 hours to prepare the polymer elastomer premix, and then vacuum it for storage; Step 2: dehydrate the polyether polyol, double-end alcohol hydroxy silicone oil, and polyester polyol at 120°C and a vacuum of -0.098 MPa or higher for 2 hours, then cool to 90°C and add isocyanate under nitrogen protection for reaction. A small amount of catalyst is appropriately added. The reaction temperature is controlled at 60-100°C and the reaction time is controlled at 2-3 hours to obtain a reactive polyurethane hot melt adhesive prepolymer for standby use. Step 3: Add the polymer elastomer premix prepared in step 1 to the reactive polyurethane hot melt adhesive prepolymer prepared in step 2, and then add a compatibilizer, a catalyst, an antioxidant, a water scavenger, etc., and knead in a kneader for 30 minutes to obtain a polyurethane hot melt adhesive for textiles with a soft hand feel. Beneficial effects

[0016] The present invention selects a polymer elastomeric material to modify a reactive polyurethane hot melt adhesive prepolymer with a soft feel, fast rebound, and small deformation. The resulting polyurethane hot melt adhesive product for textiles exhibits the excellent properties of a polymer elastomeric material overall. Furthermore, the reactive polyurethane hot melt adhesive prepolymer is prepared using a soft polyether polyol and an aliphatic isocyanate. The polyurethane hot melt adhesive product thus developed has a very soft feel and also possesses the characteristics of a reactive adhesive. After curing, the product colloid stretches under an external force, and when the external force is removed, it quickly retracts to its original length with almost no deformation, exhibits rapid rebound, and has a high recovery rate. This makes it very suitable for use as a polyurethane hot melt adhesive for high-elasticity textiles. The present invention cleverly utilizes double-terminal hydroxy silicone oil, whose main chain is a Si-O-Si structure, characterized by long bond length, large bond angle, and moderate crosslinking density, as a polyurethane raw material to form a three-dimensional crosslinked network in the polyurethane hot melt adhesive. Because the long and flexible chain segments between crosslinking points in the polyurethane hot melt adhesive molecules can undergo large, reversible entropy elastic deformation and have a very low glass transition temperature, they can ensure that the chain segments have high mobility within a wide operating temperature range and can quickly respond to external force deformation and shape recovery; the weak intermolecular force can reduce the resistance of the recovery process; the double hydroxy structure also increases the polarity and compatibility of the hydroxy silicone oil, making it easy to react with isocyanate, enhancing the performance of the polyurethane prepolymer, and increasing the softness, rebound speed, and rebound recovery rate of the polyurethane hot melt adhesive product; The present invention uses polyether polyol and aliphatic isocyanate as raw materials when preparing the polyurethane prepolymer, which results in weak overall cohesive strength and insufficient rebound speed and rebound recovery rate. Therefore, a small amount of trifunctional polyether polyol is added to promote internal cross-linking of the polyurethane polymer to form a three-dimensional network polymer structure, thereby greatly improving the cohesive strength, rebound speed, and rebound recovery rate of the polyurethane hot melt adhesive product. Since the polyurethane prepolymer and high molecular weight elastomer premix in the developed polyurethane hot melt adhesive system are materials of different polarity and have poor compatibility, an appropriate type and amount of compatibilizer is used in the process of physical blending and kneading the polyurethane prepolymer and high molecular weight elastomer premix. This allows the blended materials to fuse more fully and bring out the excellent properties of each material, ensuring that the developed polyurethane hot melt adhesive for textiles has excellent comprehensive performance. Through ingenious molecular design, the polyurethane hot melt adhesive for high-elastic textiles developed by the present invention shows good applicability when used in the bonding of high-elastic fabrics such as spandex fabrics. For example, the rebound rate of the bonded fabric reaches more than 99.3%, and the bonded fabric feels soft and has a smooth appearance. DETAILED DESCRIPTION

[0017] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. It is obvious that the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of the present invention.

[0018] Example 1: A method for preparing a soft-touch memory-modified textile reactive polyurethane hot melt adhesive (PUR) is provided. The method specifically comprises the following steps: Step 1: First, heat the three-necked flask to about 160°C in an oil bath, then slowly add the formulated amount of plasticizer and tackifying resin, and at the same time add a small amount of antioxidant. After high-speed dispersion for 30 minutes, add the polymer elastomer (TPE), and continue high-speed dispersion while removing water under a vacuum of more than -0.098MPa for more than 2 hours to obtain the elastomer premix, and then vacuum it for storage.

[0019] Step 2: Dehydrate the polyether polyol, double-end hydroxy silicone oil, and polyester polyol at 120°C and a vacuum of -0.098 MPa or above for 2 hours, then cool to 90°C and add isocyanate under nitrogen protection to react, and appropriately add a small amount of catalyst. The reaction temperature is controlled at 80~120°C, and the reaction time is controlled at 2~3 hours to obtain a prepolymer for standby use.

[0020] Step 3: Add the elastomer premix prepared in step 1 to the polyurethane hot melt adhesive prepolymer in step 2, and then add a compatibilizer, a catalyst, an antioxidant, a water scavenger, etc., and knead in a kneader for 30 minutes to obtain a soft-touch memory-type modified textile reactive polyurethane hot melt adhesive PUR.

[0021] The weight ratio of the tackifying resin (hydrogenated petroleum resin) : plasticizer (cyclohexane oil) : polymer elastomer (SIS) : antioxidant (1076) described in step 1 is 44.7% : 10% : 45% : 0.3%.

[0022] The weight ratio of the polyether polyol, dihydroxy silicone oil: polyester polyol (poly(1,6-hexanediol adipate), catalyst (dibutyltin dilaurate), and HMDI (4,4'-dicyclohexylmethane diisocyanate) described in step 2 is 20%: 40%: 25%: 0.01%: 15%; the polyether polyol used is a mixed polyol with a weight ratio of 2 functionality with a number average molecular weight of 2000: 3 functionality with a number average molecular weight of 5000 = 5:1; the dihydroxy silicone oil used is dihydroxy silicone oil MY2110, with an active content of 99.9% and a number average molecular weight of 1000.

[0023] The weight ratio described in step 3 is 60% of the elastomer premix of step 1, 25% of the polyurethane hot melt adhesive prepolymer of step 2, 13.4% of the compatibilizer (maleic anhydride grafted EVA), 0.01% of the catalyst DMDEE (bis(2,2-morpholinoethyl) ether), 0.3% of the antioxidant 1076 (chemical name: β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate), 1% of the water scavenger (triethyl orthoformate), and 0.3% of the non-silicone polymer defoamer (BYK-555).

[0024] Example 2: A method for preparing a soft-touch memory-modified textile reactive polyurethane hot melt adhesive (PUR) is provided. The method specifically comprises the following steps: Step 1: First, heat the three-necked flask to about 160°C in an oil bath, then slowly add the formulated amount of plasticizer and tackifying resin, and at the same time add a small amount of antioxidant. After high-speed dispersion for 30 minutes, add the polymer elastomer (TPE), and continue high-speed dispersion while removing water under a vacuum of more than -0.098MPa for more than 2 hours to obtain the elastomer premix, and then vacuum it for storage.

[0025] Step 2: Dehydrate the polyether polyol, double-end hydroxy silicone oil, and polyester polyol at 120°C and a vacuum of -0.098 MPa or above for 2 hours, then cool to 90°C and add isocyanate under nitrogen protection to react, and appropriately add a small amount of catalyst. The reaction temperature is controlled at 80~120°C, and the reaction time is controlled at 2~3 hours to obtain a prepolymer for standby use.

[0026] Step 3: Add the elastomer premix prepared in step I to the polyurethane hot melt adhesive prepolymer in step II, and then add a compatibilizer, a catalyst, an antioxidant, a water scavenger, etc., and knead in a kneader for 30 minutes to obtain a soft-touch memory-type modified textile reactive polyurethane hot melt adhesive PUR.

[0027] The weight ratio of the tackifying resin (terpene resin) : plasticizer (aliphatic diacid ester) : polymer elastomer (TPU) : antioxidant (1076) described in step 1 is 60%: 15%: 24.7%: 0.3%.

[0028] The weight ratio of the polyether polyol, dihydroxy silicone oil: polyester polyol (poly(1,6-hexanediol adipate), catalyst (bismuth neodecanoate), and CHDI (1,4-cyclohexyl diisocyanate) described in step 2 is 30%: 40%: 15%: 0.05%: 15%; wherein the polyether polyol used is a mixed polyol, and the weight ratio is 2 functionality with a number average molecular weight of 2000: 3 functionality with a number average molecular weight of 700 = 10:1; the dihydroxy silicone oil used is dihydroxy silicone oil MY 2110, with an active content of 99.9% and a number average molecular weight of 2000.

[0029] The weight ratios described in step 3 are 65% of the elastomer premix of step 1, 30% of the polyurethane hot melt adhesive prepolymer of step 2, 3.4% of the compatibilizer (maleic anhydride grafted EVA ethylene-vinyl acetate copolymer), 0.01% of the catalyst DMDEE (bis(2,2-morpholinoethyl) ether), 0.3% of the antioxidant 1076 (β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate), 1% of the water scavenger (triethyl orthoformate), and 0.3% of the non-silicone polymer defoamer (BYK-555).

[0030] Example 3: A method for preparing a soft-touch memory-modified textile reactive polyurethane hot melt adhesive (PUR) is provided. The method specifically comprises the following steps: Step 1: First, heat the three-necked flask to about 160°C in an oil bath, then slowly add the formulated amount of plasticizer and tackifying resin, and at the same time add a small amount of antioxidant. After high-speed dispersion for 30 minutes, add the polymer elastomer (TPE), and continue high-speed dispersion while removing water under a vacuum of more than -0.098MPa for more than 2 hours to obtain the elastomer premix, and then vacuum it for storage.

[0031] Step 2: Dehydrate the polyether polyol, double-end hydroxy silicone oil, and polyester polyol at 120°C and a vacuum of -0.098 MPa or above for 2 hours, then cool to 90°C and add isocyanate under nitrogen protection to react, and appropriately add a small amount of catalyst. The reaction temperature is controlled at 80~120°C, and the reaction time is controlled at 2~3 hours to obtain a prepolymer for standby use.

[0032] Step 3: Add the elastomer premix prepared in step 1 to the polyurethane hot melt adhesive prepolymer in step 2, and then add a compatibilizer, a catalyst, an antioxidant, a water scavenger, etc., and knead in a kneader for 30 minutes to obtain a soft-touch memory-type modified textile reactive polyurethane hot melt adhesive PUR.

[0033] The weight ratio of the tackifying resin (monomer resin): plasticizer (paraffin oil): polymer elastomer (silicone rubber): antioxidant (1076) described in step 1 is 54.7%:15%:30%:0.3%.

[0034] The weight ratio of the polyether polyol, dihydroxy silicone oil: polyester polyol (polybutylene adipate-1,4-diol), catalyst (dibutyltin dilaurate), and HXDI (cyclohexane dimethylene diisocyanate) described in step 2 is 40%: 20%: 30%: 0.01%: 10%; the polyether polyol used is a mixed polyol, and the weight ratio is 8:1 for difunctionality with a number average molecular weight of 1000: trifunctionality with a number average molecular weight of 5000; the dihydroxy silicone oil used is dihydroxy silicone oil MY2110, with an active content of 99.9% and a number average molecular weight of 2500.

[0035] The weight ratios described in step 3 are: 30% of the elastomer premix of step 1, 60% of the polyurethane hot melt adhesive prepolymer of step 2, 8.4% of the compatibilizer (maleic anhydride grafted EVA ethylene-vinyl acetate copolymer), 0.01% of the catalyst DMDEE (bis(2,2-morpholinoethyl) ether), 0.3% of the antioxidant 1076 (β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate), 1% of the water scavenger (triethyl orthoformate), and 0.3% of the non-silicone polymer defoamer (BYK-555).

[0036] Comparative Example 1 is the same as Example 1, except that the polyether polyols used in step 2 are all difunctional polyether diols with a number average molecular weight of 2000; the remaining steps, amounts, and ratios are the same as those in Example 1.

[0037] Comparative Example 2 is the same as Example 2, except that the isocyanate in Step 2 is diphenylmethane-4,4'-diisocyanate; the remaining steps, amounts, and ratios are the same as those in Example 2.

[0038] Comparative Example 3 is the same as Example 3, except that the terminal alcohol hydroxy silicone oil used in step 2 is completely replaced by polyether polyol; the remaining steps, amounts, and ratios are the same as those in Example 3.

[0039] Comparative Example 4 is the same as Example 3, except that the percentage of the compatibilizer in step 3 is reduced to 2%, and the remaining 6.4% by weight is replaced by the polyurethane hot melt adhesive prepolymer in step 2, that is, the percentage of the polyurethane hot melt adhesive prepolymer is 66.4%; the remaining steps, amounts, and ratios are the same as in Example 3.

[0040] Raw material information All raw material grades and other related information in the above examples and comparative examples are as follows: SBS is YH792, SIS is YH1106, EVA is Mitsui DuPont 40W, TPU is Wanhua 6190H, silicone rubber is HD9920, hydrogenated petroleum resin is ExxonMobil 5300, monomer resin is Kraton SA-85, and terpene resin is Kraton TRB115.

[0041] Performance Testing Melt viscosity of Examples 1-3 and Comparative Examples 1-4 was tested using a Brookfield viscometer with a 27# spindle at 130°C according to HG / 3660-1999. Hardness was also tested using a Shore C durometer with reference to GB / T531-1999. Dumbbell plates were prepared with reference to GB / T528-1998, and the tensile strength and elongation at break of the colloid were tested. Rebound rate and rebound recovery rate were tested with reference to GB / T7759-2015. A fixed 10 cm rubber strip was repeatedly stretched to 500% deformation position 10 times at a speed of 100 mm / s. After the clamp was released, the strip was tested to see whether it could eventually recover to 10 cm in length. The rebound rate and rebound recovery rate were determined by the time it took for the strip to recover approximately 10 cm in length. Referencing FZ / T 63006-2010 and FZ / T60021-2010, the adhesive was clamped in a 10mm*100mm mold and applied to a spandex fabric with a squeegee to a thickness of 50μ. Another piece of spandex was aligned and laminated, followed by hot pressing at 120°C for 10 seconds and curing for 48 hours under a standard environment of 25°C and 55% RH. The laminated spandex fabric was sheared and subjected to a constant rate elongation tester at a fixed elongation of 50%, repeated five times. The resilience and surface smoothness of the laminated fabric were observed. The test results are shown in the table below:

[0042] As can be seen from the data in the table above, each of the examples of the present application has low hardness and excellent rebound recovery rate and rebound speed performance. Moreover, when used in the lamination of high-elasticity spandex fabric, they demonstrated satisfactory performance: the laminated fabric rebound rate reached over 99.3%, the laminated fabric had a smooth appearance, and the Shore C hardness was less than 20, which is classified as soft. However, due to the lack of trifunctional polyether in Comparative Example 1, its tensile strength and elongation at break were reduced. Due to the addition of aromatic diphenylmethane-4,4'-diisocyanate, the hardness and tensile strength of Comparative Example 2 were greatly improved, but its elongation at break and rebound efficiency were reduced. Due to the lack of dihydroxyl silicone oil in Comparative Example 3, its rebound rate was greatly reduced. Due to the addition of too little compatibilizer in Comparative Example 4, the components were not evenly dispersed and fused, and phase separation was obvious. The data fluctuated greatly during the test, which was of no practical significance and clearly did not meet the requirements of use. Therefore, the data is not listed.

[0043] The above content is merely an example and explanation of the concept of the present invention. Personnel in the technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

Claims

1. A polyurethane hot melt adhesive for soft and highly elastic textiles, comprising a reactive polyurethane hot melt adhesive prepolymer and a polymer elastomer premix, characterized in that: The invention comprises the following ingredients in weight percentage, calculated by resin amount: 20-70% reactive polyurethane hot melt adhesive prepolymer, 20-75% polymer elastomer premix, 3-20% compatibilizer, 0.1-0.5% defoamer, 0.01-0.1% catalyst, 0.1-0.5% antioxidant, and 1-2% water scavenger; the compatibilizer is a maleic anhydride grafted polymer; the raw materials for preparing the reactive polyurethane hot melt adhesive prepolymer include aliphatic isocyanate, polyester polyol, polyether diol, tri- or higher-functionality polyether polyol, and di-terminal hydroxy silicone oil.

2. The polyurethane hot melt adhesive for soft and highly elastic textiles according to claim 1, characterized in that: The reactive polyurethane hot melt adhesive prepolymer is prepared from the following components in weight percentage: polyether polyol, double-end hydroxy silicone oil, polyester polyol, catalyst, and isocyanate in a weight ratio of 10-50%: 10-40%: 10-40%: 0.01-0.1%: 10-30%.

3. The polyurethane hot melt adhesive for soft and highly elastic textiles according to claim 1 or 2, characterized in that: The polymer elastomer premix is ​​prepared from the following components in weight percentage: tackifying resin: plasticizer: polymer elastomer: antioxidant (35-70%): (5-20%): (15-55%): (0.1-0.5%).

4. The polyurethane hot melt adhesive for soft and highly elastic textiles according to claim 3, characterized in that: The polymer elastomer is a mixture of one or more of SBS, SIS, thermoplastic polyurethane elastomer, EVA, natural rubber, and silicone rubber; the tackifying resin is a mixture of one or more of petroleum resin, hydrogenated petroleum resin, monomer resin, terpene resin, and rosin resin; the plasticizer is a mixture of one or more of aliphatic diacid ester, naphthenic oil, and paraffin; and the antioxidant is a mixture of one or more of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and octadecyl 3,5-di-tert-butyl-4-hydroxyphenylpropionate.

5. The polyurethane hot melt adhesive for soft and highly elastic textiles according to claim 2, characterized in that: The polyether polyol is polyoxypropylene polyol and polytetramethylene glycol, has a molecular weight of 650-5000, a functionality of 2 and / or 3, and a water content of ≤500ppm.

6. The polyurethane hot melt adhesive for soft and highly elastic textiles according to claim 1 or 2, characterized in that: The double-terminal alcohol hydroxy silicone oil has a molecular weight of 1000-2500 and an active content of >98%.

7. The polyurethane hot melt adhesive for soft and highly elastic textiles according to claim 2, characterized in that: The polyester polyol is selected from one or more of polyethylene adipate glycol, polybutylene adipate glycol, polyhexane adipate glycol, and polyhexane adipate glycol, and has a molecular weight of 1000-3000, a functionality of 2, and a water content of ≤500ppm.

8. The polyurethane hot melt adhesive for soft and highly elastic textiles according to claim 2, characterized in that: The synthesis catalyst used in the reactive polyurethane hot melt adhesive prepolymer is one or more of dibutyltin dilaurate, stannous octoate, and bismuth neodecanoate.

9. The polyurethane hot melt adhesive for soft and highly elastic textiles according to claim 2, characterized in that: The isocyanate is a mixture of one or more of HMDI (4,4'-dicyclohexylmethane diisocyanate), IPDI (isophorone diisocyanate), HXDI (cyclohexane dimethylene diisocyanate), HDI (hexamethylene diisocyanate), and CHDI (1,4-cyclohexyl diisocyanate).

10. The polyurethane hot melt adhesive for soft and highly elastic textiles according to claim 1, characterized in that: The defoaming agent is a non-silicone polymer, brand BYK-555, the catalyst is bis(2,2-morpholinoethyl) ether, the antioxidant is β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, and the water scavenger is triethyl orthoformate.

11. The method for preparing the polyurethane hot melt adhesive for soft and highly elastic textiles according to claims 1 to 10, characterized in that: Prepare as follows: Step 1: First, heat the three-necked flask to about 160°C in an oil bath, then slowly add the formulated amount of plasticizer and tackifying resin, and at the same time, add a small amount of antioxidant. After high-speed dispersion for 30 minutes, add the polymer elastomer, and continue high-speed dispersion while removing water under a vacuum of more than -0.098MPa for more than 2 hours to prepare the polymer elastomer premix, and then vacuum it for storage; Step 2: dehydrate the polyether polyol, double-end alcohol hydroxy silicone oil, and polyester polyol at 120°C and a vacuum of -0.098 MPa or higher for 2 hours, then cool to 90°C and add isocyanate under nitrogen protection for reaction. A small amount of catalyst is appropriately added. The reaction temperature is controlled at 60-100°C and the reaction time is controlled at 2-3 hours to obtain a reactive polyurethane hot melt adhesive prepolymer for standby use. Step 3: Add the polymer elastomer premix prepared in step 1 to the reactive polyurethane hot melt adhesive prepolymer prepared in step 2, and then add a compatibilizer, a catalyst, an antioxidant, a water scavenger, etc., and knead in a kneader for 30 minutes to obtain a polyurethane hot melt adhesive for textiles with a soft hand feel.

Images