Waterproof fabric for outdoor tents and preparation process thereof

Abstract

The present invention relates to the technical field of waterproof fabrics, and specifically to a waterproof fabric for outdoor tents and a preparation process thereof. The present invention involves reacting allylmalonic acid with polyethylene glycol 200 to obtain a cross-linking monomer having a hydroxyl terminal group and a double bond. To further improve hydrophobicity, 3-methacryloyldopamine, acrylic acid, butyl acrylate, and octadecyl methacrylate are mixed to obtain a mixed monomer. The mixed monomer is polymerized with the double bonds on the cross-linking monomer, thereby introducing the mixed monomer into a polyurethane side chain for modification to obtain a polyacrylate-modified polyurethane emulsion. The polyacrylate-modified polyurethane emulsion is then applied to the surface of a fabric to form a hydrophobic, breathable, and self-repairing coating, which can be used to prepare waterproof fabrics for outdoor tents.

Description

Technical Field

[0001] The present invention relates to the technical field of waterproof fabrics, in particular to a waterproof fabric for outdoor tents and a preparation process thereof. Background Art

[0002] Outdoor tents are very common for camping, wilderness adventures, and other outdoor activities. In outdoor environments, tent fabrics need to possess excellent waterproof properties to protect users from rain. A common waterproof fabric for outdoor tents is coated fabric. This fabric typically has a surface coating that provides waterproofing. Common coating materials include polyvinyl chloride (PVC) and polyurethane (PU). These coatings can be bonded to the fabric through methods such as heat sealing, gluing, or lamination to form a waterproof layer.

[0003] Considering that outdoor tents are prone to moisture and heat accumulation during use, especially in humid or hot environments, this can create a negative user experience. Furthermore, long-term use can damage the hydrophobic coating on the tent's surface. Therefore, when developing waterproof fabrics for outdoor tents, it's important not only to fully consider the tent's breathability but also to enhance the strength of the hydrophobic coating to extend its lifespan. Summary of the Invention

[0004] The object of the present invention is to provide a waterproof fabric for outdoor tents and a preparation process thereof, so as to solve the problems raised in the above background technology.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: a waterproof fabric for outdoor tents and a preparation process thereof, comprising the following steps:

[0006] Step 1:

[0007] Allylmalonic acid, polyethylene glycol 200 and p-toluenesulfonic acid are mixed, toluene is added as a solvent, and the temperature is raised and refluxed to react to obtain a cross-linking monomer;

[0008] Step 2:

[0009] After vacuum dehydration of the raw materials, poly(1,4-butylene adipate) diol and isophorone diisocyanate were mixed and reacted under nitrogen protection; dimethylol propionic acid was added after cooling, and 1,4-butylene glycol and stannous octoate were added after heating to react, and the reaction was continued and a cross-linking monomer was added; after the reaction, the temperature was lowered, triethylamine was added to form a salt, and then deionized water was used for emulsification, and ethylenediamine was added dropwise to obtain a modified polyurethane emulsion;

[0010] Step 3:

[0011] S1: mixing 3-methacryloyldopamine, acrylic acid, butyl acrylate, and octadecyl methacrylate to obtain a mixed monomer;

[0012] S2: adding 1-hydroxybenzotriazole and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride to the modified polyurethane emulsion, adding potassium persulfate and mixed monomers in 4 to 5 portions, and reacting to obtain a polyacrylate-modified polyurethane emulsion;

[0013] Step 4:

[0014] A thickener is added to the polyacrylate modified polyurethane emulsion, the fabric is coated on one side, vacuum dried and then vacuum baked to obtain a waterproof fabric for outdoor tents.

[0015] Furthermore, in step 1, the amounts of the components used, by weight, are 28 to 30 parts of allylmalonic acid, 40 to 42 parts of polyethylene glycol 200, and 0.95 to 1 part of p-toluenesulfonic acid.

[0016] Furthermore, in step 2, the specific preparation method of the modified polyurethane emulsion is as follows: after vacuum dehydrating the raw materials, take poly (1,4-butylene adipate) diol and isophorone diisocyanate and mix them, and react at 80-90°C for 1-1.5 hours under nitrogen protection; then cool to 40-50°C, add dihydroxymethylpropionic acid, raise the temperature to 80-90°C and react for 0.5-1 hour, then add 1,4-butanediol and stannous octoate, raise the temperature to 75-80°C and react for 2-3 hours, add a cross-linking monomer, react at 75-80°C for 2-3 hours, cool to 30-40°C, add triethylamine to form a salt for 10-15 minutes, then add deionized water and emulsify for 20-30 minutes, and add ethylenediamine dropwise to react for 5-10 minutes to obtain a modified polyurethane emulsion.

[0017] Furthermore, in S1, the contents of the components in the mixed monomer are, by weight percentage, 2-3% 3-methacryloyldopamine, 40-50% acrylic acid, 48-53% butyl acrylate, and 5-10% octadecyl methacrylate.

[0018] Furthermore, in S2, the specific preparation method of the polyacrylate modified polyurethane emulsion is: add 1-hydroxybenzotriazole and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride to the modified polyurethane emulsion, take potassium persulfate and mixed monomers, add them in 4 to 5 times, react for 1 to 2 hours, heat to 80 to 90°C, keep the reaction at this temperature for 0.5 to 1 hour, and cool to 25 to 35°C to obtain the polyacrylate modified polyurethane emulsion.

[0019] Furthermore, in S2, the contents of each component, by weight, are 80 to 95 parts of modified polyurethane emulsion, 6 to 7 parts of 1-hydroxybenzotriazole, 8 to 9 parts of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, 0.15 to 0.18 parts of potassium persulfate, and 20 to 25 parts of mixed monomers.

[0020] Furthermore, in step 4, the thickener is used to adjust the viscosity of the emulsion to 1000-1200 mPa·s.

[0021] Furthermore, in step 4, the coating amount is 28 to 32 g / m 2 .

[0022] Furthermore, in step 4, the vacuum drying temperature is 70-80° C., and the time is 5-10 min; the vacuum baking temperature is 140-150° C., and the time is 5-10 min.

[0023] Compared with the prior art, the beneficial effect achieved by the present invention is: the present invention prepares a polyacrylate-modified polyurethane emulsion, which can be applied to the surface of a fabric to obtain a waterproof fabric that is waterproof, breathable and has self-repairing ability, and can be used to prepare outdoor tents.

[0024] When preparing a polyacrylate-modified polyurethane emulsion, the present invention reacts allylmalonic acid with polyethylene glycol 200 to obtain a cross-linking monomer having a terminal hydroxyl group and a double bond; the cross-linking monomer is introduced into the polyurethane emulsion to improve the moisture permeability of the polyurethane emulsion after forming a coating; however, the introduction of the cross-linking monomer will lead to a decrease in the hydrophobicity of the polyurethane coating, so 3-methacryloyl dopamine, acrylic acid, butyl acrylate, and octadecyl methacrylate are mixed to obtain a mixed monomer, and the mixed monomer is introduced into the polyurethane side chain to achieve modification to obtain a polyacrylate-modified polyurethane emulsion; the coating formed by the modified emulsion has stronger mechanical strength, and since the mixed monomer contains 3-methacryloyl dopamine, the coating is endowed with self-healing properties, and octadecyl methacrylate is a long-chain hydrophobic monomer that migrates to the outer layer, which not only improves the hydrophobicity of the coating surface, but also migrates the 3-methacryloyl dopamine in the polyurethane side chain to the coating surface, thereby improving the self-healing efficiency of the coating.

[0025] When adding mixed monomers, the amount of 3-methacryloyldopamine in the mixed monomers needs to be limited. Because 3-methacryloyldopamine itself contains dopamine molecular segments, excessive levels can reduce hydrophobicity. Furthermore, premature self-polymerization during the emulsion preparation process can cause the molecular segments to agglomerate, creating a "knotted" effect and affecting the self-healing properties of the molecular segments. Therefore, controlling the amount of 3-methacryloyldopamine to 2-3% is optimal. DETAILED DESCRIPTION

[0026] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, 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 ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0027] Materials used in the present invention and their sources: polyethylene glycol 200 comes from Jiangsu Dena Chemical, with a hydroxyl value of 510-623 mgKOH / g; the thickener is hydroxypropyl methylcellulose, which comes from Qida Chemical; the fabric is polyester silk 190T, which comes from Yifeng Textiles, with the product number YF-75.

[0028] Example 1: A waterproof fabric for outdoor tents and a preparation process thereof, comprising the following steps:

[0029] Step 1:

[0030] 28 g of allylmalonic acid, 40 g of polyethylene glycol 200, and 0.95 g of p-toluenesulfonic acid were mixed, and 200 g of toluene was added as a solvent; the temperature was slowly raised to 140°C and maintained at reflux for 20 h; the reaction was continued for 6 h to obtain a crosslinking monomer;

[0031] Step 2:

[0032] After vacuum dehydration of the raw materials, 22 g of poly(1,4-butylene adipate) diol and 11.5 g of isophorone diisocyanate were mixed and reacted at 80° C. for 1 h under nitrogen protection; then the temperature was lowered to 40° C., 1.6 g of dimethylolpropionic acid was added, the temperature was raised to 80° C. for reaction for 0.5 h, 0.7 g of 1,4-butylene glycol and 0.18 g of stannous octoate were added, the temperature was raised to 75° C. for reaction for 2 h, 3.8 g of crosslinking monomer was added, the temperature was lowered to 30° C., 1.45 g of triethylamine was added to form a salt for 10 min, 24 g of deionized water was added to emulsify for 20 min, and 0.46 g of ethylenediamine was added dropwise for reaction for 5 min to obtain a modified polyurethane emulsion;

[0033] Step 3:

[0034] S1: 3% 3-methacryloyldopamine, 40% acrylic acid, 50% butyl acrylate, and 7% octadecyl methacrylate were mixed to obtain a mixed monomer, based on weight percentage.

[0035] S2: To 91 kg of the modified polyurethane emulsion, 6.2 kg of 1-hydroxybenzotriazole and 8.4 kg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride were added, and 0.15 kg of potassium persulfate and 22 kg of the mixed monomer were added in four portions. After reacting for 1 hour, the temperature was raised to 80° C., kept at this temperature for 0.5 hour, and then cooled to 25° C. to obtain a polyacrylate-modified polyurethane emulsion.

[0036] Step 4:

[0037] Add thickener to polyacrylate modified polyurethane emulsion, adjust the emulsion viscosity to 1000mPa·s, and coat the fabric on one side with a coating amount of 28g / m 2, vacuum dried at 70°C for 5 min, and then vacuum baked at 140°C for 5 min to obtain waterproof fabric for outdoor tents.

[0038] Example 2: A waterproof fabric for outdoor tents and a preparation process thereof, comprising the following steps:

[0039] Step 1:

[0040] 28 g of allylmalonic acid, 40 g of polyethylene glycol 200, and 0.95 g of p-toluenesulfonic acid were mixed, and 200 g of toluene was added as a solvent; the temperature was slowly raised to 140°C and maintained at reflux for 20 h; the reaction was continued for 6.5 h to obtain a crosslinking monomer;

[0041] Step 2:

[0042] After vacuum dehydration of the raw materials, 22 g of poly(1,4-butylene adipate) diol and 11.5 g of isophorone diisocyanate were mixed and reacted at 82° C. for 1 h under nitrogen protection; then the temperature was lowered to 45° C., 1.6 g of dimethylolpropionic acid was added, the temperature was raised to 82° C. for reaction for 0.5 h, 0.7 g of 1,4-butylene glycol and 0.18 g of stannous octoate were added, the temperature was raised to 75° C. for reaction for 2.5 h, 3.8 g of crosslinking monomer was added, the temperature was lowered to 30° C., 1.45 g of triethylamine was added to form a salt for 12 min, 24 g of deionized water was added to emulsify for 25 min, 0.46 g of ethylenediamine was added dropwise and reacted for 7 min to obtain a modified polyurethane emulsion;

[0043] Step 3:

[0044] S1: 3% 3-methacryloyldopamine, 40% acrylic acid, 50% butyl acrylate, and 7% octadecyl methacrylate were mixed to obtain a mixed monomer, based on weight percentage.

[0045] S2: To 91 kg of the modified polyurethane emulsion, 6.2 kg of 1-hydroxybenzotriazole and 8.4 kg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride were added, and 0.15 kg of potassium persulfate and 22 kg of the mixed monomer were added in four portions. After reacting for 1.5 h, the temperature was raised to 82° C., kept at this temperature for 0.5 h, and then cooled to 25° C. to obtain a polyacrylate-modified polyurethane emulsion.

[0046] Step 4:

[0047] Add thickener to polyacrylate modified polyurethane emulsion, adjust the emulsion viscosity to 1000mPa·s, and coat the fabric on one side with a coating amount of 28g / m 2 , vacuum dried at 75°C for 6.5 min, and then vacuum baked at 145°C for 6 min to obtain waterproof fabric for outdoor tents.

[0048] Example 3: A waterproof fabric for outdoor tents and a preparation process thereof, comprising the following steps:

[0049] Step 1:

[0050] 28 g of allylmalonic acid, 40 g of polyethylene glycol 200, and 0.95 g of p-toluenesulfonic acid were mixed, and 200 g of toluene was added as a solvent; the temperature was slowly raised to 145°C and maintained at reflux for 22 h; the reaction was continued for 7 h to obtain a crosslinking monomer;

[0051] Step 2:

[0052] After vacuum dehydration of the raw materials, 22 g of poly(1,4-butylene adipate) diol and 11.5 g of isophorone diisocyanate were mixed and reacted at 85° C. for 1.2 h under nitrogen protection; then the temperature was lowered to 42° C., 1.6 g of dimethylolpropionic acid was added, the temperature was raised to 82° C. for reaction for 0.75 h, 0.7 g of 1,4-butylene glycol and 0.18 g of stannous octoate were added, the temperature was raised to 75° C. for reaction for 3 h, 3.8 g of crosslinking monomer was added, the temperature was lowered to 30° C., 1.45 g of triethylamine was added to form a salt for 13 min, 24 g of deionized water was added to emulsify for 27 min, and 0.46 g of ethylenediamine was added dropwise for reaction for 7 min to obtain a modified polyurethane emulsion;

[0053] Step 3:

[0054] S1: 3% 3-methacryloyldopamine, 40% acrylic acid, 50% butyl acrylate, and 7% octadecyl methacrylate were mixed to obtain a mixed monomer, based on weight percentage.

[0055] S2: To 91 kg of the modified polyurethane emulsion, 6.2 kg of 1-hydroxybenzotriazole and 8.4 kg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride were added, and 0.15 kg of potassium persulfate and 22 kg of the mixed monomer were added in four portions. After reacting for 2 h, the temperature was raised to 85° C., kept at this temperature for 0.75 h, and then cooled to 30° C. to obtain a polyacrylate-modified polyurethane emulsion.

[0056] Step 4:

[0057] Add thickener to polyacrylate modified polyurethane emulsion, adjust the emulsion viscosity to 1000mPa·s, and coat the fabric on one side with a coating amount of 28g / m 2 , vacuum dried at 75°C for 8 min, and then vacuum baked at 142°C for 8 min to obtain waterproof fabric for outdoor tents.

[0058] Example 4: A waterproof fabric for outdoor tents and a preparation process thereof, comprising the following steps:

[0059] Step 1:

[0060] 28 g of allylmalonic acid, 40 g of polyethylene glycol 200, and 0.95 g of p-toluenesulfonic acid were mixed, and 200 g of toluene was added as a solvent; the temperature was slowly raised to 145°C and maintained at reflux for 22 h; the reaction was continued for 7.5 h to obtain a crosslinking monomer;

[0061] Step 2:

[0062] After vacuum dehydration of the raw materials, 22 g of poly(1,4-butylene adipate) diol and 11.5 g of isophorone diisocyanate were mixed and reacted at 86° C. for 1 h under nitrogen protection; then the temperature was lowered to 46° C., 1.6 g of dimethylolpropionic acid was added, the temperature was raised to 86° C. for reaction for 0.5 h, 0.7 g of 1,4-butylene glycol and 0.18 g of stannous octoate were added, the temperature was raised to 75° C. for reaction for 2.8 h, 3.8 g of crosslinking monomer was added, the temperature was lowered to 38° C., 1.45 g of triethylamine was added to form a salt for 13 min, 24 g of deionized water was added and emulsified for 27 min, 0.46 g of ethylenediamine was added dropwise and reacted for 7.5 min to obtain a modified polyurethane emulsion;

[0063] Step 3:

[0064] S1: 3% 3-methacryloyldopamine, 40% acrylic acid, 50% butyl acrylate, and 7% octadecyl methacrylate were mixed to obtain a mixed monomer, based on weight percentage.

[0065] S2: To 91 kg of the modified polyurethane emulsion, 6.2 kg of 1-hydroxybenzotriazole and 8.4 kg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride were added, and 0.15 kg of potassium persulfate and 22 kg of the mixed monomer were added in 5 portions. After reacting for 1 hour, the temperature was raised to 85° C., kept at this temperature for 0.75 hour, and then cooled to 31° C. to obtain a polyacrylate-modified polyurethane emulsion.

[0066] Step 4:

[0067] Add thickener to polyacrylate modified polyurethane emulsion, adjust the emulsion viscosity to 1000mPa·s, and coat the fabric on one side with a coating amount of 28g / m 2 , vacuum dried at 77°C for 8 minutes, and then vacuum baked at 145°C for 10 minutes to obtain waterproof fabric for outdoor tents.

[0068] Example 5: A waterproof fabric for outdoor tents and a preparation process thereof, comprising the following steps:

[0069] Step 1:

[0070] 28 g of allylmalonic acid, 40 g of polyethylene glycol 200, and 0.95 g of p-toluenesulfonic acid were mixed, and 200 g of toluene was added as a solvent; the temperature was slowly raised to 148°C and maintained at reflux for 24 h; the reaction was continued for 7.5 h to obtain a crosslinking monomer;

[0071] Step 2:

[0072] After vacuum dehydration of the raw materials, 22 g of poly(1,4-butylene adipate) diol and 11.5 g of isophorone diisocyanate were mixed and reacted at 83° C. for 1.4 h under nitrogen protection; then the temperature was lowered to 48° C., 1.6 g of dimethylolpropionic acid was added, the temperature was raised to 87° C. and the reaction was carried out for 0.85 h, 0.7 g of 1,4-butylene glycol and 0.18 g of stannous octoate were added, the temperature was raised to 78° C. and the reaction was carried out for 2.8 h, 3.8 g of a crosslinking monomer was added, the temperature was lowered to 38° C., 1.45 g of triethylamine was added to form a salt for 13 min, 24 g of deionized water was added and the mixture was emulsified for 27.5 min, and 0.46 g of ethylenediamine was added dropwise and the reaction was carried out for 8.5 min to obtain a modified polyurethane emulsion;

[0073] Step 3:

[0074] S1: 3% 3-methacryloyldopamine, 40% acrylic acid, 50% butyl acrylate, and 7% octadecyl methacrylate were mixed to obtain a mixed monomer, based on weight percentage.

[0075] S2: To 91 kg of the modified polyurethane emulsion, 6.2 kg of 1-hydroxybenzotriazole and 8.4 kg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride were added, and 0.15 kg of potassium persulfate and 22 kg of the mixed monomer were added in 5 portions. After reacting for 2 h, the temperature was raised to 90° C., kept at this temperature for 0.5 h, and then cooled to 32° C. to obtain a polyacrylate-modified polyurethane emulsion.

[0076] Step 4:

[0077] Add thickener to polyacrylate modified polyurethane emulsion, adjust the emulsion viscosity to 1000mPa·s, and coat the fabric on one side with a coating amount of 28g / m 2 , vacuum dried at 76°C for 9.5 min, and then vacuum baked at 147°C for 9.5 min to obtain waterproof fabric for outdoor tents.

[0078] Example 6: A waterproof fabric for outdoor tents and a preparation process thereof, comprising the following steps:

[0079] Step 1:

[0080] 28 g of allylmalonic acid, 40 g of polyethylene glycol 200, and 0.95 g of p-toluenesulfonic acid were mixed, and 200 g of toluene was added as a solvent; the temperature was slowly raised to 150°C and kept under reflux for 24 h; the reaction was continued for 8 h to obtain a crosslinking monomer;

[0081] Step 2:

[0082] After vacuum dehydration of the raw materials, 22 g of poly(1,4-butylene adipate) diol and 11.5 g of isophorone diisocyanate were mixed and reacted at 90° C. for 1.5 h under nitrogen protection; then the temperature was lowered to 50° C., 1.6 g of dimethylolpropionic acid was added, the temperature was raised to 90° C. for reaction for 1 h, 0.7 g of 1,4-butylene glycol and 0.18 g of stannous octoate were added, the temperature was raised to 80° C. for reaction for 3 h, 3.8 g of a crosslinking monomer was added, the temperature was lowered to 40° C., 1.45 g of triethylamine was added to form a salt for 15 min, 24 g of deionized water was added to emulsify for 30 min, and 0.46 g of ethylenediamine was added dropwise to react for 10 min to obtain a modified polyurethane emulsion;

[0083] Step 3:

[0084] S1: 3% 3-methacryloyldopamine, 40% acrylic acid, 50% butyl acrylate, and 7% octadecyl methacrylate were mixed to obtain a mixed monomer, based on weight percentage.

[0085] S2: Add 6.2 kg of 1-hydroxybenzotriazole and 8.4 kg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride to 91 kg of the modified polyurethane emulsion, take 0.15 kg of potassium persulfate and 22 kg of mixed monomers, add them in 5 portions, react for 2 hours, raise the temperature to 90° C., keep the temperature for 1 hour, and cool to 35° C. to obtain a polyacrylate modified polyurethane emulsion;

[0086] Step 4:

[0087] Add thickener to polyacrylate modified polyurethane emulsion, adjust the emulsion viscosity to 1000mPa·s, and coat the fabric on one side with a coating amount of 28g / m 2 , vacuum dried at 80°C for 10 min, and then vacuum baked at 150°C for 10 min to obtain waterproof fabric for outdoor tents.

[0088] Comparative Example 1: No cross-linking monomer was added, and other parameters were the same as those in Example 1.

[0089] Step 1:

[0090] After vacuum dehydration of the raw materials, 22 g of poly(1,4-butylene adipate) diol and 11.5 g of isophorone diisocyanate were mixed and reacted at 80° C. for 1 h under nitrogen protection; then the temperature was lowered to 40° C., 1.6 g of dimethylolpropionic acid was added, the temperature was raised to 80° C. for reaction for 0.5 h, 0.7 g of 1,4-butylene glycol and 0.18 g of stannous octoate were added, the temperature was raised to 75° C. for reaction for 2 h, the temperature was lowered to 30° C., 1.45 g of triethylamine was added to form a salt for 10 min, 24 g of deionized water was added to emulsify for 20 min, and 0.46 g of ethylenediamine was added dropwise for reaction for 5 min to obtain a polyurethane emulsion;

[0091] Step 2:

[0092] S1: 3% 3-methacryloyldopamine, 40% acrylic acid, 50% butyl acrylate, and 7% octadecyl methacrylate were mixed to obtain a mixed monomer, based on weight percentage.

[0093] S2: To 91 kg of polyurethane emulsion, 6.2 kg of 1-hydroxybenzotriazole and 8.4 kg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride were added, and 0.15 kg of potassium persulfate and 22 kg of mixed monomers were added in four portions. After reacting for 1 hour, the temperature was raised to 80° C., kept at this temperature for 0.5 hour, and then cooled to 25° C. to obtain a polyacrylate-modified polyurethane emulsion.

[0094] Step 3:

[0095] Add thickener to polyacrylate modified polyurethane emulsion, adjust the emulsion viscosity to 1000mPa·s, and coat the fabric on one side with a coating amount of 28g / m 2 , vacuum dried at 70°C for 5 min, and then vacuum baked at 140°C for 5 min to obtain waterproof fabric for outdoor tents.

[0096] Comparative Example 2: Polyacrylate was not used to modify the polyurethane, and the remaining parameters were the same as those in Example 2.

[0097] Step 1:

[0098] 28 g of allylmalonic acid, 40 g of polyethylene glycol 200, and 0.95 g of p-toluenesulfonic acid were mixed, and 200 g of toluene was added as a solvent; the temperature was slowly raised to 140°C and maintained at reflux for 20 h; the reaction was continued for 6.5 h to obtain a crosslinking monomer;

[0099] Step 2:

[0100] After vacuum dehydration of the raw materials, 22 g of poly(1,4-butylene adipate) diol and 11.5 g of isophorone diisocyanate were mixed and reacted at 82° C. for 1 h under nitrogen protection; then the temperature was lowered to 45° C., 1.6 g of dimethylolpropionic acid was added, the temperature was raised to 82° C. for reaction for 0.5 h, 0.7 g of 1,4-butylene glycol and 0.18 g of stannous octoate were added, the temperature was raised to 75° C. for reaction for 2.5 h, 3.8 g of crosslinking monomer was added, the temperature was lowered to 30° C., 1.45 g of triethylamine was added to form a salt for 12 min, 24 g of deionized water was added to emulsify for 25 min, 0.46 g of ethylenediamine was added dropwise and reacted for 7 min to obtain a modified polyurethane emulsion;

[0101] Step 3:

[0102] Add thickener to the modified polyurethane emulsion, adjust the emulsion viscosity to 1000mPa·s, and coat the fabric on one side with a coating amount of 28g / m 2 , vacuum dried at 75°C for 6.5 min, and then vacuum baked at 145°C for 6 min to obtain waterproof fabric for outdoor tents.

[0103] Comparative Example 3: The amount of 3-methacryloyldopamine in the mixed monomer was increased, and the other parameters were the same as those in Example 3.

[0104] Step 1:

[0105] 28 g of allylmalonic acid, 40 g of polyethylene glycol 200, and 0.95 g of p-toluenesulfonic acid were mixed, and 200 g of toluene was added as a solvent; the temperature was slowly raised to 145°C and maintained at reflux for 22 h; the reaction was continued for 7 h to obtain a crosslinking monomer;

[0106] Step 2:

[0107] After vacuum dehydration of the raw materials, 22 g of poly(1,4-butylene adipate) diol and 11.5 g of isophorone diisocyanate were mixed and reacted at 85° C. for 1.2 h under nitrogen protection; then the temperature was lowered to 42° C., 1.6 g of dimethylolpropionic acid was added, the temperature was raised to 82° C. for reaction for 0.75 h, 0.7 g of 1,4-butylene glycol and 0.18 g of stannous octoate were added, the temperature was raised to 75° C. for reaction for 3 h, 3.8 g of crosslinking monomer was added, the temperature was lowered to 30° C., 1.45 g of triethylamine was added to form a salt for 13 min, 24 g of deionized water was added to emulsify for 27 min, and 0.46 g of ethylenediamine was added dropwise for reaction for 7 min to obtain a modified polyurethane emulsion;

[0108] Step 3:

[0109] S1: 10% 3-methacryloyldopamine, 40% acrylic acid, 43% butyl acrylate, and 7% octadecyl methacrylate were mixed to obtain a mixed monomer, based on weight percentage.

[0110] S2: To 91 kg of the modified polyurethane emulsion, 6.2 kg of 1-hydroxybenzotriazole and 8.4 kg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride were added, and 0.15 kg of potassium persulfate and 22 kg of the mixed monomer were added in four portions. After reacting for 2 h, the temperature was raised to 85° C., kept at this temperature for 0.75 h, and then cooled to 30° C. to obtain a polyacrylate-modified polyurethane emulsion.

[0111] Step 4:

[0112] Add thickener to polyacrylate modified polyurethane emulsion, adjust the emulsion viscosity to 1000mPa·s, and coat the fabric on one side with a coating amount of 28g / m 2 , vacuum dried at 75°C for 8 min, and then vacuum baked at 142°C for 8 min to obtain waterproof fabric for outdoor tents.

[0113] Comparative Example 4: No octadecyl methacrylate was added to the mixed monomers, and the other parameters were the same as those in Example 4.

[0114] Step 1:

[0115] 28 g of allylmalonic acid, 40 g of polyethylene glycol 200, and 0.95 g of p-toluenesulfonic acid were mixed, and 200 g of toluene was added as a solvent; the temperature was slowly raised to 145°C and maintained at reflux for 22 h; the reaction was continued for 7.5 h to obtain a crosslinking monomer;

[0116] Step 2:

[0117] After vacuum dehydration of the raw materials, 22 g of poly(1,4-butylene adipate) diol and 11.5 g of isophorone diisocyanate were mixed and reacted at 86° C. for 1 h under nitrogen protection; then the temperature was lowered to 46° C., 1.6 g of dimethylolpropionic acid was added, the temperature was raised to 86° C. for reaction for 0.5 h, 0.7 g of 1,4-butylene glycol and 0.18 g of stannous octoate were added, the temperature was raised to 75° C. for reaction for 2.8 h, 3.8 g of crosslinking monomer was added, the temperature was lowered to 38° C., 1.45 g of triethylamine was added to form a salt for 13 min, 24 g of deionized water was added and emulsified for 27 min, 0.46 g of ethylenediamine was added dropwise and reacted for 7.5 min to obtain a modified polyurethane emulsion;

[0118] Step 3:

[0119] S1: 3% 3-methacryloyldopamine, 47% acrylic acid, and 50% butyl acrylate were mixed to obtain a mixed monomer, based on weight percentage.

[0120] S2: To 91 kg of the modified polyurethane emulsion, 6.2 kg of 1-hydroxybenzotriazole and 8.4 kg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride were added, and 0.15 kg of potassium persulfate and 22 kg of the mixed monomer were added in 5 portions. After reacting for 1 hour, the temperature was raised to 85° C., kept at this temperature for 0.75 hour, and then cooled to 31° C. to obtain a polyacrylate-modified polyurethane emulsion.

[0121] Step 4:

[0122] Add thickener to polyacrylate modified polyurethane emulsion, adjust the emulsion viscosity to 1000mPa·s, and coat the fabric on one side with a coating amount of 28g / m 2 , vacuum dried at 77°C for 8 minutes, and then vacuum baked at 145°C for 10 minutes to obtain waterproof fabric for outdoor tents.

[0123] Experiment: The emulsions in Examples 1 to 6 and Comparative Examples 1 to 4 were poured onto a polytetrafluoroethylene plate and dried at 60°C for 24 hours to obtain a coating film with a thickness of about 0.6 mm. The mechanical properties, water contact angle, and transmittance of the waterproof fabric of the film were tested respectively. The experimental results are shown in the following table.

[0124] Mechanical properties test: A 4mm×25mm dumbbell-shaped coating film was tested using an intelligent electronic tensile testing machine at a tensile speed of 100mm / min, and the average value of three tests was taken.

[0125] Water contact angle test: Use a contact angle meter to measure the water contact angle of the coating and take the average value of 3 points;

[0126] Repair performance test: Take a 2mm wide coating film, cut it with a knife, and place the two ends of the fracture side by side. Then put it in an oven and bake it at 60℃ for 6 hours to repair the fracture.

[0127] Moisture permeability: The moisture permeability of waterproof fabrics is tested according to the national standard GB / T 12704-1991. The test is repeated three times and the average value is taken.

[0128] project Mechanical properties / MPa Water contact angle / ° Regeneration test <![CDATA[Water vapor transmission rate / kgm -2 24h -1 > Example 1 14.28 108.3 Repairable 3.24 Example 2 14.39 108.6 Repairable 3.28 Example 3 14.33 108.1 Repairable 3.26 Example 4 14.27 107.9 Repairable 3.27 Example 5 14.25 109.3 Repairable 3.25 Example 6 14.29 109.7 Repairable 3.26 Comparative Example 1 12.51 104.6 Not fully repaired 2.83 Comparative Example 2 10.78 84.3 Unable to repair 3.22 Comparative Example 3 14.81 108.4 Not fully repaired / Comparative Example 4 / 92.3 Not fully repaired /

[0129] Conclusion: The data from Examples 1 to 6 show that the emulsion prepared by the present invention has good waterproof and moisture permeability after forming a coating. After the coating breaks, the fracture can be automatically repaired after being treated at 60°C for 6 hours. Applying the emulsion prepared by the present invention to the surface of fabric can ensure that the fabric has good moisture permeability and the user feels good when using it. The data from Comparative Example 1 and Example 1 show that the addition of a cross-linking monomer not only improves the mechanical strength of the coating but also enhances the moisture permeability. The data from Comparative Example 2 and Example 2 show that after modifying the polyurethane with polyacrylate, the mechanical strength and hydrophobicity of the coating are further improved, while also imparting the coating with self-healing ability. The data from Comparative Example 3 and Example 3 show that increasing the amount of 3-methacryloyldopamine in the mixed monomer slightly decreases the hydrophobicity of the coating surface and deteriorates the self-healing ability. The data from Comparative Example 4 and Example 4 show that the addition of octadecyl methacrylate not only enhances the hydrophobicity of the coating but also improves the self-healing efficiency of the coating.

[0130] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A process for preparing waterproof fabric for outdoor tents, characterized by: The following steps are involved: Step 1: Allylmalonic acid, polyethylene glycol 200 and p-toluenesulfonic acid are mixed, toluene is added as a solvent, and the temperature is raised and refluxed to react to obtain a cross-linking monomer; Step 2: After vacuum dehydration of the raw materials, poly(1,4-butylene adipate) diol and isophorone diisocyanate were mixed and reacted under nitrogen protection; dimethylol propionic acid was added, and after the reaction, 1,4-butylene glycol and stannous octoate were added, and the reaction was continued, and a cross-linking monomer was added. After the reaction, the temperature was lowered and triethylamine was added to form a salt, and the mixture was emulsified with deionized water and ethylenediamine was added dropwise to obtain a modified polyurethane emulsion; Step 3: S1: mixing 3-methacryloyldopamine, acrylic acid, butyl acrylate, and octadecyl methacrylate to obtain a mixed monomer; S2: adding 1-hydroxybenzotriazole and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride to the modified polyurethane emulsion, adding potassium persulfate and mixed monomers in 4 to 5 portions, and reacting to obtain a polyacrylate-modified polyurethane emulsion; Step 4: A thickener is added to a polyacrylate-modified polyurethane emulsion, the fabric is coated on one side, vacuum dried, and then vacuum baked to obtain a waterproof fabric for outdoor tents; In step 1, the amounts of the components used are, by weight, 28 to 30 parts of allylmalonic acid, 40 to 42 parts of polyethylene glycol 200, and 0.95 to 1 part of p-toluenesulfonic acid; In step 2, the amounts of the components used are, by weight, 22 parts of poly(1,4-butylene adipate diol), 11.5 parts of isophorone diisocyanate, 1.6 parts of dimethylol propionic acid, 0.7 parts of 1,4-butanediol, 0.18 parts of stannous octoate, 3.8 parts of a crosslinking monomer, 1.45 parts of triethylamine salt, 24 parts of deionized water, and 0.46 parts of ethylenediamine; In S1, the content of each component in the mixed monomer, by weight percentage, is 2-3% 3-methacryloyldopamine, 40-50% acrylic acid, 48-53% butyl acrylate, and 5-10% octadecyl methacrylate; In S2, the content of each component, by weight, is 80 to 95 parts of modified polyurethane emulsion, 6 to 7 parts of 1-hydroxybenzotriazole, 8 to 9 parts of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, 0.15 to 0.18 parts of potassium persulfate, and 20 to 25 parts of mixed monomers.

2. The process for preparing a waterproof fabric for outdoor tents according to claim 1, characterized in that: In step 2, the specific preparation method of the modified polyurethane emulsion is as follows: after vacuum dehydrating the raw materials, take poly (1,4-butylene adipate) diol and isophorone diisocyanate and mix them, and react at 80-90° C. for 1-1.5 hours under nitrogen protection; then cool to 40-50° C., add dihydroxymethylpropionic acid, heat to 80-90° C. and react for 0.5-1 hour, then add 1,4-butanediol and stannous octoate, heat to 75-80° C. and react for 2-3 hours, add a cross-linking monomer, react at 75-80° C. for 2-3 hours, cool to 30-40° C., add triethylamine to form a salt for 10-15 minutes, then add deionized water and emulsify for 20-30 minutes, and add ethylenediamine dropwise to react for 5-10 minutes to obtain the modified polyurethane emulsion.

3. The process for preparing a waterproof fabric for outdoor tents according to claim 1, characterized in that: In S2, the specific preparation method of the polyacrylate modified polyurethane emulsion is: add 1-hydroxybenzotriazole and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride to the modified polyurethane emulsion, take potassium persulfate and mixed monomers, add them in 4 to 5 times, react for 1 to 2 hours, heat to 80 to 90°C, keep the temperature for reaction for 0.5 to 1 hour, and cool to 25 to 35°C to obtain the polyacrylate modified polyurethane emulsion.

4. The process for preparing a waterproof fabric for outdoor tents according to claim 1, characterized in that: In step 4, the thickener is used to adjust the viscosity of the emulsion to 1000-1200 mPa·s.

5. The process for preparing a waterproof fabric for outdoor tents according to claim 1, characterized in that: In step 4, the coating amount is 28 to 32 g / m 2 .

6. The process for preparing a waterproof fabric for outdoor tents according to claim 1, characterized in that: In step 4, the vacuum drying temperature is 70-80° C., and the time is 5-10 minutes; the vacuum baking temperature is 140-150° C., and the time is 5-10 minutes.

7. An outdoor tent prepared by the process for preparing a waterproof fabric for an outdoor tent according to any one of claims 1 to 6.