Waterproof moisture-permeable hot melt adhesive as well as preparation method and gluing process thereof

Abstract

The invention discloses a waterproof moisture-permeable hot melt adhesive as well as a preparation method and a gluing process thereof, and belongs to the field of bonding materials. The waterproof moisture-permeable hot melt adhesive is prepared from the following raw materials in parts by weight: 100 parts of polyurethane resin; 5 to 10 parts of tackifying resin; 10 to 15 parts of filler; the polyurethane resin is prepared from the following raw materials in parts by weight: 30-40 parts of polyethylene glycol; 15 to 20 parts of polytetramethylene ether glycol; 15 to 30 parts of polycarbonate diol; 30 to 35 parts of diisocyanate; and 5-10 parts of a chain extender. The hot melt adhesive has the advantages that the overall curing speed and water resistance of the hot melt adhesive are improved.

Description

Technical Field

[0001] The present application relates to the field of adhesive materials, and in particular to a waterproof and moisture-permeable hot-melt adhesive and a preparation method and a gluing process thereof. Background Art

[0002] The currently popular hot melt adhesive types include PUR hot melt adhesive, which is a moisture-curing reactive polyurethane hot melt adhesive. The advantages of PUR hot melt adhesive are high bonding strength, good chemical corrosion resistance and aging resistance. Therefore, it has become one of the important varieties in the adhesive industry and is widely used in economic fields such as packaging, wood processing, textiles, and electromechanical.

[0003] In addition, PUR hot melt adhesive is a single-component curing adhesive and does not require the addition of a curing agent before use. The main component of PUR hot melt adhesive is a polyurethane prepolymer terminated with an isocyanate group. The isocyanate group reacts with water vapor in the air to achieve the curing of the hot melt adhesive. Therefore, it is quick and easy to use and has a fast surface drying speed.

[0004] Although PUR hot melt adhesive has a fast surface drying speed, the internal curing of the colloid is slow, which affects the overall curing speed of the colloid, and its water resistance is poor. Summary of the invention

[0005] In order to improve the overall curing speed and water resistance of the hot melt adhesive, the present application provides a waterproof and moisture permeable hot melt adhesive and a preparation method and a gluing process thereof.

[0006] In the first aspect, the present application provides a waterproof and breathable hot melt adhesive adopting the following technical solution: A waterproof and breathable hot melt adhesive is prepared by including the following raw materials in parts by weight: 100 parts of polyurethane resin; 5-10 parts of tackifying resin; 10-15 parts of filler; The polyurethane resin is prepared by including the following raw materials in parts by weight: 30-40 parts of polyethylene glycol; 15-20 parts of polytetramethylene ether glycol; 15-30 parts of polycarbonate diol; 30-35 parts of diisocyanate; Chain extender 5-10 parts.

[0007] By adopting the above technical scheme, polyethylene glycol, polytetramethylene ether glycol and polycarbonate diol are compounded as the polyols used to synthesize the polyurethane resin. The colloid formed by the obtained hot melt adhesive has a porous and breathable structure, which helps the water vapor in the air to enter the interior of the colloid during the curing process, so as to achieve the purpose of rapid curing. At the same time, by adjusting the compounding ratio of polyethylene glycol, polytetramethylene ether glycol and polycarbonate diol, the respective characteristics of the above diols are fully utilized to achieve the smooth spreading of the chain segments, and cross-linked chain segments that are difficult to hydrolyze are formed in the colloid, so as to achieve good water resistance. In addition, the chain segments are evenly cross-linked and distributed, so that the hot melt adhesive colloid has good softness.

[0008] Due to the structure of the colloid that allows water vapor to enter and the water-resistant segment structure, the hot melt adhesive has good waterproof and moisture permeability, and is suitable for use in textile products to improve the rainproof and sweat-proof functions of textile products. The colloid has good softness, which further improves the comfort of touch.

[0009] Optionally, the number average molecular weight of the polyethylene glycol is 1500-3500, the number average molecular weight of the polytetramethylene ether glycol is 1000-3500, and the number average molecular weight of the polycarbonate diol is 1000-3000.

[0010] By adopting the above technical solution, the air permeability and water resistance of the hot melt adhesive are balanced. If the air permeability of the surface of the hot melt adhesive is too high in the initial stage of colloid formation, the cross-linking of the difficult-to-hydrolyze chain segments will be affected. Therefore, it is necessary to select polyethylene glycol, polytetramethylene ether glycol and polycarbonate diol with specific molecular weights to form a hot melt adhesive colloid skeleton, so as to achieve the effect of simultaneously improving the curing speed and water resistance of the hot melt adhesive colloid.

[0011] Optionally, the number average molecular weight of the polyethylene glycol is 2500-3000, the number average molecular weight of the polytetramethylene ether glycol is 3000-3500, and the number average molecular weight of the polycarbonate diol is 1500-2000.

[0012] By adopting the above technical scheme, the molecular weight combination of polyethylene glycol, polytetramethylene ether glycol and polycarbonate diol is optimized, and the space of the hot melt adhesive colloid skeleton is adjusted, so that the hydrogen bonding between the chain segments is enhanced, the flexibility of the cross-linked chain segments is ensured, and good bonding ability can be maintained even at low temperatures. It is suitable for the scenario of drying washed clothes at low temperatures in winter.

[0013] Optionally, the mass ratio of the polyethylene glycol, polytetramethylene ether glycol and polycarbonate diol is 1:(0.5-0.55):(0.65-0.75).

[0014] By adopting the above technical solution, the skeleton space of the hot melt adhesive is further improved, and the low-temperature stability of the colloid is ensured while the waterproof and moisture permeability capabilities are improved.

[0015] Optionally, the diisocyanate is one or both of diphenylmethane diisocyanate and toluene diisocyanate.

[0016] By adopting the above technical solution, the above isocyanate can provide good mechanical properties and stability and high reaction activity.

[0017] Optionally, the chain extender is one or both of 1,4-butanediol and 1,6-hexanediol.

[0018] By adopting the above technical solution, the chain extender can increase the molecular weight of the hot melt adhesive and improve the bonding performance.

[0019] Optionally, the chain extender is selected from 1,4-butanediol and 1,6-hexanediol in a weight ratio of 1:(0.2-0.5).

[0020] By adopting the above technical solution, 1,4-butanediol and 1,6-hexanediol are compounded to extend the chain, thereby improving the heat resistance of the hot melt adhesive colloid, making it more suitable for washing clothes in hot water.

[0021] Optionally, the tackifying resin is polystyrene resin; and the filler is fumed silica.

[0022] By adopting the above technical solution, the waterproof performance and affinity to the substrate are increased.

[0023] In the second aspect, the present application provides a method for preparing a waterproof and breathable hot melt adhesive using the following technical solution: A method for preparing a waterproof and moisture-permeable hot melt adhesive comprises the following steps: Polyethylene glycol, polytetramethylene ether glycol, polycarbonate diol and part of filler are mixed, inert gas is introduced for protection, heated, diisocyanate is added for prepolymerization, chain extender is added for further reaction, and material is discharged to obtain polyurethane resin; The polyurethane resin, the tackifying resin and the remaining fillers are heated and mixed evenly, and the materials are discharged to obtain a waterproof and moisture-permeable hot melt adhesive.

[0024] Optionally, a method for preparing a waterproof and moisture-permeable hot melt adhesive comprises the following steps: Mix polyethylene glycol, polytetramethylene ether glycol, polycarbonate diol and part of filler, pass inert gas protection, heat to 70-85°C, add diisocyanate and prepolymerize for 1.5-2h, then add chain extender and continue reaction for 1-1.5h, discharge and obtain polyurethane resin; The polyurethane resin is heated to 150-165° C., a tackifying resin and remaining fillers are added and mixed evenly, and the material is discharged to obtain a waterproof and moisture-permeable hot melt adhesive.

[0025] By adopting the above technical solution, adding fillers in batches helps to disperse the fillers evenly, so as to avoid the problem of difficulty in melting caused by uneven dispersion in the later stage.

[0026] In the third aspect, the present application provides a waterproof and breathable hot melt adhesive coating process using the following technical solutions: A process for coating a waterproof and breathable hot melt adhesive, comprising the following steps: The waterproof and breathable hot melt adhesive is melted and applied to the surface of the substrate to be bonded by roller coating, and the surface of the roller is provided with protrusions that are evenly and spaced apart.

[0027] By adopting the above technical solution, point bonding of materials is achieved, and the hot melt adhesive is evenly and dispersedly coated on the surface of the substrate. The glue points are evenly and equidistantly distributed, and air circulation and humidity are increased between the gaps, which further promotes the solidification of the colloid. In addition, since the amount of glue in point bonding is small, the glue layer is thinner, which further improves the softness of the materials after bonding.

[0028] In summary, this application has the following beneficial effects: 1. The present application adopts a compound of polyethylene glycol, polytetramethylene ether glycol and polycarbonate diol as the polyols used to synthesize the polyurethane resin. The colloid formed by the obtained hot melt adhesive has a porous and breathable structure, which helps the water vapor in the air to enter the interior of the colloid during the curing process, thereby achieving the purpose of rapid curing. At the same time, by adjusting the compounding ratio of polyethylene glycol, polytetramethylene ether glycol and polycarbonate diol, the characteristics of the above diols are fully utilized to achieve the smooth spreading of the chain segments, and cross-linked chain segments that are difficult to hydrolyze are formed in the colloid, thereby achieving good water resistance. In addition, the chain segments are evenly cross-linked and distributed, so that the hot melt adhesive colloid has good softness and meets the requirements of waterproof and moisture permeability.

[0029] 2. The present application also optimizes the molecular weight combination of polyethylene glycol, polytetramethylene ether glycol and polycarbonate diol, adjusts the hot melt adhesive colloid skeleton space, enhances the hydrogen bonding between the chain segments, ensures the flexibility of the cross-linked chain segments, and maintains good bonding ability even at low temperatures. It is suitable for drying washed clothes at low temperatures in winter. DETAILED DESCRIPTION

[0030] The present application is described in further detail below.

[0031] Example 1 A method for preparing a waterproof and moisture-permeable hot melt adhesive comprises the following steps: Weigh 3kg of polyethylene glycol, 2kg of polytetramethylene ether glycol, 1.5kg of polycarbonate diol, 3kg of 4,4'-diphenylmethane diisocyanate, 0.5kg of 1,4-butanediol, and 0.05kg of filler. The number average molecular weight of polyethylene glycol is 1500; the molecular weight of polytetramethylene ether glycol is 1000; polycarbonate diol is prepared by transesterification of dimethyl carbonate and 1,4-butanediol, and the number average molecular weight is 1000; the filler is fumed silica.

[0032] Polyethylene glycol, polytetramethylene ether glycol, polycarbonate diol and filler were mixed, nitrogen was introduced for protection, the reaction system was heated to 70°C, 4,4'-diphenylmethane diisocyanate was added and prepolymerized for 2 hours, 1,4-butanediol was added and the reaction was continued for 1.5 hours, and the material was discharged to obtain a polyurethane resin.

[0033] Weigh 1 kg of the polyurethane resin, 0.05 kg of tackifying resin and 0.05 kg of filler prepared above, wherein the tackifying resin is polystyrene resin W90 from Cray Valley, and the filler is fumed silica.

[0034] The polyurethane resin is heated to 150° C., a tackifying resin and a filler are added and mixed evenly, and the material is discharged to obtain a waterproof and moisture-permeable hot melt adhesive.

[0035] Example 2 A method for preparing a waterproof and moisture-permeable hot melt adhesive comprises the following steps: Weigh 4kg of polyethylene glycol, 1.5kg of polytetramethylene ether glycol, 3kg of polycarbonate diol, 3.5kg of 4,4'-diphenylmethane diisocyanate, 1kg of 1,4-butanediol, and 0.08kg of filler. The number average molecular weight of polyethylene glycol is 3500; the molecular weight of polytetramethylene ether glycol is 3500; polycarbonate diol is prepared by transesterification of dimethyl carbonate and 1,4-butanediol, and has a number average molecular weight of 3000; and the filler is fumed silica.

[0036] Polyethylene glycol, polytetramethylene ether glycol, polycarbonate diol and filler were mixed, nitrogen was introduced for protection, the reaction system was heated to 85°C, 4,4'-diphenylmethane diisocyanate was added and prepolymerization was carried out for 1.5 hours, 1,4-butanediol was added and the reaction was continued for 1 hour, and the material was discharged to obtain a polyurethane resin.

[0037] Weigh 1 kg of the polyurethane resin, 0.1 kg of tackifying resin and 0.07 kg of filler prepared above, wherein the tackifying resin is polystyrene resin W90 from Cray Valley, and the filler is fumed silica.

[0038] The polyurethane resin is heated to 165° C., a tackifying resin and a filler are added and mixed evenly, and the material is discharged to obtain a waterproof and breathable hot melt adhesive.

[0039] Example 3 A method for preparing a waterproof and moisture-permeable hot melt adhesive comprises the following steps: Weigh 3.5kg of polyethylene glycol, 1.6kg of polytetramethylene ether glycol, 1.8kg of polycarbonate diol, 3.3kg of 4,4'-diphenylmethane diisocyanate, 0.6kg of 1,4-butanediol, and 0.06kg of filler. The number average molecular weight of polyethylene glycol is 1500; the molecular weight of polytetramethylene ether glycol is 1000; polycarbonate diol is prepared by transesterification of dimethyl carbonate and 1,4-butanediol, and the number average molecular weight is 1000; the filler is fumed silica.

[0040] Polyethylene glycol, polytetramethylene ether glycol, polycarbonate diol and filler were mixed, nitrogen was introduced for protection, the reaction system was heated to 70°C, 4,4'-diphenylmethane diisocyanate was added and prepolymerized for 2 hours, 1,4-butanediol was added and the reaction was continued for 1.5 hours, and the material was discharged to obtain a polyurethane resin.

[0041] 1 kg of the polyurethane resin, 0.08 kg of tackifying resin and 0.06 kg of filler were weighed, wherein the tackifying resin was polystyrene resin W90 from Cray Valley and the filler was fumed silica.

[0042] The polyurethane resin is heated to 150° C., a tackifying resin and a filler are added and mixed evenly, and the material is discharged to obtain a waterproof and moisture-permeable hot melt adhesive.

[0043] Example 4 A method for preparing a waterproof and moisture-permeable hot melt adhesive, which is different from Example 3 in that the preparation method of the polyurethane resin is different.

[0044] Weigh 3.5kg of polyethylene glycol, 1.6kg of polytetramethylene ether glycol, 1.8kg of polycarbonate diol, 3.3kg of 4,4'-diphenylmethane diisocyanate, 0.6kg of 1,4-butanediol, and 0.06kg of filler. The number average molecular weight of polyethylene glycol is 2500; the molecular weight of polytetramethylene ether glycol is 3000; polycarbonate diol is prepared by transesterification of dimethyl carbonate and 1,4-butanediol, and has a number average molecular weight of 1500; and the filler is fumed silica.

[0045] Polyethylene glycol, polytetramethylene ether glycol, polycarbonate diol and filler were mixed, nitrogen was introduced for protection, the reaction system was heated to 70°C, 4,4'-diphenylmethane diisocyanate was added and prepolymerized for 2 hours, 1,4-butanediol was added and the reaction was continued for 1.5 hours, and the material was discharged to obtain a polyurethane resin.

[0046] Example 5 A method for preparing a waterproof and moisture-permeable hot melt adhesive, which is different from Example 3 in that the preparation method of the polyurethane resin is different.

[0047] Weigh 3.5kg of polyethylene glycol, 1.6kg of polytetramethylene ether glycol, 1.8kg of polycarbonate diol, 3.3kg of 4,4'-diphenylmethane diisocyanate, 0.6kg of 1,4-butanediol, and 0.06kg of filler. The number average molecular weight of polyethylene glycol is 3000; the molecular weight of polytetramethylene ether glycol is 3500; polycarbonate diol is prepared by transesterification of dimethyl carbonate and 1,4-butanediol, and has a number average molecular weight of 2000; and the filler is fumed silica.

[0048] Polyethylene glycol, polytetramethylene ether glycol, polycarbonate diol and filler were mixed, nitrogen was introduced for protection, the reaction system was heated to 70°C, 4,4'-diphenylmethane diisocyanate was added and prepolymerized for 2 hours, 1,4-butanediol was added and the reaction was continued for 1.5 hours, and the material was discharged to obtain a polyurethane resin.

[0049] Example 6 A method for preparing a waterproof and moisture-permeable hot melt adhesive, which is different from Example 3 in that the preparation method of the polyurethane resin is different.

[0050] Weigh 3.5kg of polyethylene glycol, 1.75kg of polytetramethylene ether glycol, 2.275kg of polycarbonate diol, 3.3kg of 4,4'-diphenylmethane diisocyanate, 0.6kg of 1,4-butanediol, and 0.06kg of filler. The number average molecular weight of polyethylene glycol is 1500; the molecular weight of polytetramethylene ether glycol is 1000; polycarbonate diol is prepared by transesterification of dimethyl carbonate and 1,4-butanediol, and the number average molecular weight is 1000; the filler is fumed silica.

[0051] Polyethylene glycol, polytetramethylene ether glycol, polycarbonate diol and filler were mixed, nitrogen was introduced for protection, the reaction system was heated to 70°C, 4,4'-diphenylmethane diisocyanate was added and prepolymerized for 2 hours, 1,4-butanediol was added and the reaction was continued for 1.5 hours, and the material was discharged to obtain a polyurethane resin.

[0052] Example 7 A method for preparing a waterproof and moisture-permeable hot melt adhesive, which is different from Example 3 in that the preparation method of the polyurethane resin is different.

[0053] Weigh 3.5kg of polyethylene glycol, 1.75kg of polytetramethylene ether glycol, 2.275kg of polycarbonate diol, 3.3kg of 4,4'-diphenylmethane diisocyanate, 0.6kg of 1,4-butanediol, and 0.06kg of filler. The number average molecular weight of polyethylene glycol is 2500; the molecular weight of polytetramethylene ether glycol is 3000; polycarbonate diol is prepared by transesterification of dimethyl carbonate and 1,4-butanediol, and has a number average molecular weight of 1500; and the filler is fumed silica.

[0054] Polyethylene glycol, polytetramethylene ether glycol, polycarbonate diol and filler were mixed, nitrogen was introduced for protection, the reaction system was heated to 70°C, 4,4'-diphenylmethane diisocyanate was added and prepolymerized for 2 hours, 1,4-butanediol was added and the reaction was continued for 1.5 hours, and the material was discharged to obtain a polyurethane resin.

[0055] Example 8 A method for preparing a waterproof and moisture-permeable hot melt adhesive comprises the following steps: Weigh 3.5kg of polyethylene glycol, 1.925kg of polytetramethylene ether glycol, 2.625kg of polycarbonate diol, 3.3kg of 4,4'-diphenylmethane diisocyanate, 0.6kg of 1,4-butanediol, and 0.06kg of filler. The number average molecular weight of polyethylene glycol is 2500; the molecular weight of polytetramethylene ether glycol is 3000; polycarbonate diol is prepared by transesterification of dimethyl carbonate and 1,4-butanediol, and has a number average molecular weight of 1500; and the filler is fumed silica.

[0056] Polyethylene glycol, polytetramethylene ether glycol, polycarbonate diol and filler were mixed, nitrogen was introduced for protection, the reaction system was heated to 70°C, 4,4'-diphenylmethane diisocyanate was added and prepolymerized for 2 hours, 1,4-butanediol was added and the reaction was continued for 1.5 hours, and the material was discharged to obtain a polyurethane resin.

[0057] Comparative Example 1 A method for preparing a waterproof and moisture-permeable hot melt adhesive, which is different from Example 3 in that the preparation method of the polyurethane resin is different.

[0058] Weigh 5.1 kg of polyethylene glycol, 1.8 kg of polycarbonate diol, 3.3 kg of 4,4'-diphenylmethane diisocyanate, 0.6 kg of 1,4-butanediol, and 0.06 kg of filler. The number average molecular weight of polyethylene glycol is 1500; polycarbonate diol is prepared by transesterification of dimethyl carbonate and 1,4-butanediol, and has a number average molecular weight of 1000; and the filler is fumed silica.

[0059] Polyethylene glycol, polycarbonate diol and filler were mixed, nitrogen was introduced for protection, the reaction system was heated to 70°C, 4,4'-diphenylmethane diisocyanate was added and prepolymerized for 2 hours, 1,4-butanediol was added and the reaction was continued for 1.5 hours, and the material was discharged to obtain a polyurethane resin.

[0060] Comparative Example 2 A method for preparing a waterproof and moisture-permeable hot melt adhesive, which is different from Example 3 in that the preparation method of the polyurethane resin is different.

[0061] Weigh 3.5kg of polypropylene glycol, 1.6kg of polytetramethylene ether glycol, 1.8kg of polycarbonate diol, 3.3kg of 4,4'-diphenylmethane diisocyanate, 0.6kg of 1,4-butanediol, and 0.06kg of filler. Among them, the number average molecular weight of polypropylene glycol is 1500; the molecular weight of polytetramethylene ether glycol is 1000; polycarbonate diol is prepared by transesterification of dimethyl carbonate and 1,4-butanediol, and the number average molecular weight is 1000; the filler is fumed silica.

[0062] Polypropylene glycol, polytetramethylene ether glycol, polycarbonate diol and filler were mixed, nitrogen was introduced for protection, the reaction system was heated to 70°C, 4,4'-diphenylmethane diisocyanate was added and prepolymerized for 2 hours, 1,4-butanediol was added and the reaction was continued for 1.5 hours, and the material was discharged to obtain a polyurethane resin.

[0063] Comparative Example 3 A method for preparing a waterproof and moisture-permeable hot melt adhesive, which is different from Example 3 in that the preparation method of the polyurethane resin is different.

[0064] Weigh 3.5 kg of polyethylene glycol, 1.6 kg of polytetramethylene ether glycol, 1.8 kg of polyethylene adipate, 3.3 kg of 4,4'-diphenylmethane diisocyanate, 0.6 kg of 1,4-butanediol, and 0.06 kg of filler. The number average molecular weight of polyethylene glycol is 1500; the molecular weight of polytetramethylene ether glycol is 1000; the number average molecular weight of polyethylene adipate is 1000; and the filler is fumed silica.

[0065] Polyethylene glycol, polytetramethylene ether glycol, polyethylene adipate and filler were mixed, nitrogen was introduced for protection, the reaction system was heated to 70°C, 4,4'-diphenylmethane diisocyanate was added and prepolymerized for 2 hours, 1,4-butanediol was added and the reaction was continued for 1.5 hours, and the material was discharged to obtain a polyurethane resin.

[0066] Application Example 1 A process for coating a waterproof and breathable hot melt adhesive, comprising the following steps: The hot melt adhesive is heated and melted, and then applied to the surface of the roller. The roller applies the hot melt adhesive to the surface of the substrate to be bonded during the rolling process. The substrate to be bonded can be a textile fabric, specifically a cotton fabric, to achieve adhesive coating. The hot melt adhesive specifically uses the waterproof and breathable hot melt adhesive prepared in Example 1.

[0067] The roller surface is provided with evenly spaced protrusions, the spacing between the protrusions is 1 cm, the protrusions are in contact with the substrate to be bonded, and the hot melt adhesive is applied to the substrate to be bonded in a dot shape.

[0068] Application Examples 2 to 8 The difference between Application Examples 2 to 8 and Application Example 1 is that the hot melt adhesives are the waterproof and moisture permeable hot melt adhesives prepared in Examples 2 to 10, respectively.

[0069] Comparative Application Examples 1 to 3 The difference between Comparative Application Examples 1 to Comparative Application Examples 3 and Application Example 1 is that the hot melt adhesives respectively use the waterproof and moisture permeable hot melt adhesives prepared in Comparative Examples 1 to 3.

[0070] Performance Testing 5min cured shear strength: Refer to GB / T 7124-2008, and test the shear strength of the hot melt adhesive after the hot melt adhesive is cured for 5min.

[0071] 48h cured shear strength: Refer to GB / T 7124-2008, and test the shear strength of the hot melt adhesive after the hot melt adhesive is cured for 48 hours.

[0072] Cold resistance treatment: After the bonded sample is cured for 48 hours, it is placed in 5°C water for 2 hours, then taken out and placed in a sample box at 5°C and 60% RH for 10 hours, and then the conditions of the test box are adjusted to -20°C and 25% RH and left for 24 hours to simulate the scene of washing clothes in winter. Finally, the sample is taken out and the shear strength test is carried out at room temperature.

[0073] The above test results are shown in Table 1.

[0074] Water resistance: Place the bonded samples in a constant temperature and humidity test chamber with the temperature set at 70±2℃ and the humidity set at 85±2%RH. The test lasts for 7 days. After the test, observe whether the colloid has bubbling and debonding.

[0075] Moisture permeability: Melt the hot melt adhesive and then use a roller with a smooth surface to apply the hot melt adhesive into a film. After curing for 48 hours, refer to JIS L1099 B1 (potassium acetate-inverted cup method) to test the moisture permeability of the film.

[0076] Elastic modulus: Melt the hot melt adhesive and then use a smooth roller to apply the hot melt adhesive into a film. After curing for 48 hours, refer to GB / T 1040.3-2006 to test the elastic modulus of the film. The smaller the elastic modulus, the better the softness.

[0077] The above test results are shown in Table 2.

[0078] Table 1 Table 2 Water resistance Moisture permeability (g / ㎡.day) <![CDATA[Modulus of elasticity (kgf / cm 2 )]]> Example 1 No bubbling, no debonding 5280 21.5 Example 2 No bubbling, no debonding 5050 22.3 Example 3 No bubbling, no debonding 5120 20.3 Example 4 No bubbling, no debonding 5150 21.2 Example 5 No bubbling, no debonding 5100 21.0 Example 6 No bubbling, no debonding 5200 20.7 Example 7 No bubbling, no debonding 5370 18.4 Example 8 No bubbling, no debonding 5410 19.0 Comparative Example 1 Bubbling, degumming 3500 33.6 Comparative Example 2 Bubbling, no glue opening 4200 28.8 Comparative Example 3 Bubbling, degumming 3950 29.7 It can be seen from Table 1 and Table 2 that the hot melt adhesive prepared in Examples 1-3 has a shear strength of more than 1.0 N / mm after 5 minutes of initial curing, which proves that the internal curing speed of the colloid is fast, meeting the requirement of rapid curing, and has good water resistance and moisture permeability, meeting the requirements of waterproof and moisture permeability. In addition, the elastic modulus is maintained at a low level, indicating that the colloid has good softness and can be used in textile products to improve wearing comfort.

[0079] Combining Example 3 with Comparative Examples 1 to 3, different replacements were made on polyethylene glycol, polytetramethylene ether glycol and polycarbonate diol. It can be found that none of them can simultaneously meet the requirements of rapid curing and water resistance, and the softness is also greatly affected, indicating that the combination of polyethylene glycol, polytetramethylene ether glycol and polycarbonate diol jointly affects the porous structure, hydrolysis resistance and segment crosslinking distribution of the colloid.

[0080] Combining Example 3 with Example 4-Example 5, the molecular weight combination of polyethylene glycol, polytetramethylene ether glycol and polycarbonate diol is optimized. It can be found that the hot melt adhesive can still maintain good shear strength after cold-resistant treatment, and the bonding ability at low temperatures is improved.

[0081] Combining Example 3 with Example 6-Example 8, and optimizing the molecular weight and weight combinations of polyethylene glycol, polytetramethylene ether glycol, and polycarbonate diol, it can be found that in addition to improving the low temperature resistance of the hot melt adhesive, the waterproof and moisture permeability of the hot melt adhesive is also further improved.

[0082] In addition, if the chain extender of the waterproof and moisture-permeable hot melt adhesive is a compound of 1,4-butanediol and 1,6-hexanediol, higher heat resistance can be obtained.

[0083] Two improved embodiments are made based on Embodiment 3. In one embodiment, the chain extender is replaced by the original 0.6 kg 1,4-butanediol with 0.5 kg 1,4-butanediol and 0.1 kg 1,6-hexanediol. In another embodiment, the chain extender is replaced by the original 0.6 kg 1,4-butanediol with 0.4 kg 1,4-butanediol and 0.2 kg 1,6-hexanediol. In the preparation step, 1,4-butanediol is first added to react for 0.5 h, and then 1,6-hexanediol is added to react for 1 h to obtain a waterproof and moisture permeable hot melt adhesive.

[0084] The waterproof and breathable hot melt adhesives of Example 3 and the above two examples were washed with hot water. After the bonded samples were cured, they were placed in a washing machine and washed with hot water at 90°C. The washing process included soaking and drying. The washing lasted for 2 hours. After the samples were taken out, they were naturally dried and then put into the washing machine for washing. This was repeated 5 times. Finally, the samples were subjected to a shear strength test at room temperature.

[0085] The results show that after hot water washing, the shear strength of the above two embodiments is higher than the shear strength of Example 3, respectively, which proves that the heat resistance of the hot melt adhesive colloid can be improved by compounding 1,4-butanediol and 1,6-hexanediol to extend the chain on the basis of the polyurethane resin of the present application to adapt to the current trend of washing machines being able to wash clothes at high temperatures.

[0086] This specific implementation manner is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the specific implementation manner as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A waterproof and breathable hot melt adhesive, characterized in that: Prepared by including the following raw materials in parts by weight: 100 parts of polyurethane resin; 5-10 parts of tackifying resin; 10~15 parts of filler; The polyurethane resin is prepared by including the following raw materials in parts by weight: 30-40 parts of polyethylene glycol; 15-20 parts of polytetramethylene ether glycol; 15-30 parts of polycarbonate diol; 30-35 parts of diisocyanate; Chain extender 5~10 parts.

2. The waterproof and breathable hot melt adhesive according to claim 1, characterized in that: The number average molecular weight of the polyethylene glycol is 1500-3500, the number average molecular weight of the polytetramethylene ether glycol is 1000-3500, and the number average molecular weight of the polycarbonate diol is 1000-3000.

3. The waterproof and breathable hot melt adhesive according to claim 1, characterized in that: The number average molecular weight of the polyethylene glycol is 2500-3000, the number average molecular weight of the polytetramethylene ether glycol is 3000-3500, and the number average molecular weight of the polycarbonate diol is 1500-2000.

4. The waterproof and breathable hot melt adhesive according to claim 3, characterized in that: The mass ratio of the polyethylene glycol, polytetramethylene ether glycol and polycarbonate diol is 1:(0.5-0.55):(0.65-0.75).

5. The waterproof and breathable hot melt adhesive according to claim 1, characterized in that: The diisocyanate is selected from one or both of diphenylmethane diisocyanate and toluene diisocyanate.

6. The waterproof and breathable hot melt adhesive according to claim 1, characterized in that: The chain extender is selected from one or both of 1,4-butanediol and 1,6-hexanediol.

7. The waterproof and breathable hot melt adhesive according to claim 1, characterized in that: The chain extender is selected from 1,4-butanediol and 1,6-hexanediol in a weight ratio of 1:(0.2~0.5).

8. The waterproof and breathable hot melt adhesive according to claim 1, characterized in that: The tackifying resin is polystyrene resin; the filler is fumed silica.

9. A method for preparing a waterproof and breathable hot melt adhesive according to any one of claims 1 to 8, characterized in that: The following steps are involved: Polyethylene glycol, polytetramethylene ether glycol, polycarbonate diol and part of filler are mixed, inert gas is introduced for protection, heated, diisocyanate is added for prepolymerization, chain extender is added for further reaction, and material is discharged to obtain polyurethane resin; The polyurethane resin, the tackifying resin and the remaining fillers are heated and mixed evenly, and the materials are discharged to obtain a waterproof and moisture-permeable hot melt adhesive.

10. A coating process of a waterproof and breathable hot melt adhesive according to any one of claims 1 to 8, characterized in that: The following steps are involved: The waterproof and breathable hot melt adhesive is melted and applied to the surface of the substrate to be bonded by roller coating, and the surface of the roller is provided with protrusions that are evenly and spaced apart.

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