Waterborne polyurethane resin as well as preparation method and application thereof

Abstract

The invention discloses waterborne polyurethane resin as well as a preparation method and application thereof, and belongs to the technical field of macromolecular polymerization. The waterborne polyurethane resin is prepared from the following raw materials in parts by weight: 15 to 25 parts of isophorone diisocyanate, 90 to 110 parts of polyester polyol, 25 to 35 parts of tetraphenyl glycol, 10 to 20 parts of chain extender, 5 to 10 parts of end-capping reagent, 2 to 4 parts of pH regulator and 400 to 600 parts of deionized water. The waterborne polyurethane resin does not contain an organic solvent, is non-toxic and harmless, is low in emission, and meets the current environmental protection requirements; the prepared clothing leather has excellent wear resistance, folding resistance and cold resistance, the product quality of the clothing leather is effectively improved, and the requirement of the market for the quality of the clothing leather can be met.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer polymerization, and in particular relates to a waterborne polyurethane resin and a preparation method thereof and application thereof in garment leather. Background Art

[0002] Garment leather requires comfortable feel, relatively soft, and water-resistant, especially alkaline water. In addition to the base fabric and fabric layer used in garment leather meeting the requirements, the base material must also meet the above requirements. A hard base material will cause the garment leather to feel poor and stiff. As an adhesive, on the one hand, it needs to have high curing bonding strength and peel strength to meet the requirements to prevent the garment leather from delaminating during use. On the other hand, it requires a low modulus or a small molecular polarity, so that the softness requirement can be met. The low molecular polarity is contradictory to its high peel strength. At present, solvent-based polyurethane adhesives can achieve better results, but solvent-based garment leather uses a large amount of organic solvent DMF in the manufacturing process, which not only causes serious pollution to the environment, but also the residual solvent in the product poses a potential threat to human health. With the increasingly stringent global environmental regulations and the improvement of consumers' environmental awareness, the garment leather industry is in urgent need of finding a new environmentally friendly material that can replace the traditional preparation process. Waterborne polyurethane resin has become an important direction for the green transformation of the garment leather industry with its low pollution, non-toxic and harmless, and easy operation. Summary of the invention

[0003] One of the purposes of the present invention is to provide a waterborne polyurethane resin to solve the environmental pollution and health risk problems existing in the garment leather preparation process;

[0004] The second object of the present invention is to provide a method for preparing an aqueous polyurethane resin;

[0005] A third object of the present invention is to provide an application of an aqueous polyurethane resin in garment leather.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] In a first aspect, the present invention provides an aqueous polyurethane resin comprising the following raw materials in parts by weight:

[0008] 15-25 parts of isophorone diisocyanate, 90-110 parts of polyester polyol, 25-35 parts of tetraphenyl glycol, 10-20 parts of chain extender, 5-10 parts of end-capping agent, 2-4 parts of pH regulator, and 400-600 parts of deionized water.

[0009] As a further embodiment of the present invention, the polyester polyol includes polyethylene adipate diol, polypropylene adipate diol, polyethylene adipate diol, polyethylene adipate-diethylene glycol ester diol, polypropylene adipate diol, polycarbonate-1,6-hexanediol ester diol or polybutylene adipate diol.

[0010] As a further embodiment of the present invention, the chain extender is any one of 1,4-butanediol, propylene glycol and ethylene glycol.

[0011] As a further embodiment of the present invention, the end-capping agent is polystyrene.

[0012] As a further embodiment of the present invention, the amount of phorone diisocyanate is 20 parts.

[0013] As a further embodiment of the present invention, the polyester polyol is 100 parts.

[0014] As a further embodiment of the present invention, the amount of tetraphenylethylene glycol is 30 parts.

[0015] In a second aspect, the present invention provides a method for preparing an aqueous polyurethane resin, comprising the following steps:

[0016] Step 1: Weigh each component according to weight, mix isophorone diisocyanate, tetraphenyl glycol and polyester polyol evenly, and react at 110-130° C. for 4-6 hours to obtain a mixture 1;

[0017] Step 2: under stirring conditions, add a chain extender to the mixture 1 and react for 1-2 hours, then add a capping agent and continue to react for 0.5-1 hour to block the remaining active groups to obtain a mixture 2;

[0018] Step 3: At a temperature of 35-45° C., add a pH adjuster to the mixture 2 to adjust the pH to 8-9, and then add deionized water for dispersion and emulsification to obtain a waterborne polyurethane resin.

[0019] As a further solution of the present invention, the stirring speed is 200-400 rpm.

[0020] In a third aspect, a method for applying a waterborne polyurethane resin in garment leather comprises the following steps:

[0021] S1. Mixing the waterborne polyurethane resin with a crosslinker, a thickener and a pigment to form a coating;

[0022] S2. Use the textile as the base fabric, after cleaning, evenly apply the coating on the base fabric, dry and solidify it through drying equipment to obtain clothing leather.

[0023] As a further embodiment of the present invention, the weight ratio of the waterborne polyurethane resin, the crosslinking agent, the thickener and the pigment is 100:0.5-2:4-6:8-15.

[0024] As a further solution of the present invention, the cross-linking agent is a silane coupling agent ZQ-172, and adding the cross-linking agent can further improve the feel of the clothing leather.

[0025] As a further embodiment of the present invention, the thickener is RM-2020.

[0026] The garment leather can be embossed on the coating surface as required to increase the appearance and feel of the garment leather; finally, it is finished to make the garment leather reach an ideal thickness and softness, and the obtained garment leather is strictly inspected for quality and packaged after passing the inspection.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The present invention provides an organic solvent-free waterborne polyurethane resin, which is non-toxic, harmless, low-emission and meets current environmental protection requirements. In its preparation method, firstly, isophorone diisocyanate (IPDI), polyester polyol and tetraphenyl glycol are synthesized into a prepolymer, wherein IPDI, as a source of isocyanate groups, reacts with hydroxyl groups in the polyol to form carbamate bonds, and tetraphenyl glycol, as a bifunctional compound, can react with isocyanate groups to form longer polymer chains, thereby enhancing the hardness and elasticity of polyurethane materials; a chain extender further increases the molecular weight of the polymer, improves its mechanical properties and water resistance; polystyrene is used as a capping agent, which can effectively cap unreacted active groups, prevent further crosslinking or degradation of the polymer, and obtain a uniformly dispersed waterborne polyurethane resin through emulsification with deionized water.

[0029] 2. The waterborne polyurethane resin provided by the present invention is used as the main raw material in clothing leather. The obtained clothing leather has excellent wear resistance, folding resistance and cold resistance, and can meet the demand of the high-end market for clothing leather quality. DETAILED DESCRIPTION

[0030] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] A method for preparing an aqueous polyurethane resin comprises the following steps:

[0032] Step 1: Weigh each component according to weight, mix 15-25 parts of isophorone diisocyanate, 25-35 parts of tetraphenyl glycol and 90-110 parts of polyester polyol, and react at 110-130° C. for 4-6 hours to obtain a mixture 1;

[0033] Step 2: under stirring at 200-400 rpm, add 10-20 parts of chain extender to mixture 1 and react for 1-2 hours, then add 5-10 parts of end-capping agent and continue to react for 0.5-1 hour to block the remaining active groups, thereby obtaining mixture 2;

[0034] Step 3: At a temperature of 35-45° C., add 2-4 parts of a pH adjuster to the mixture 2 to adjust the pH to 8-9, and then add 400-600 parts of deionized water for dispersion and emulsification to obtain a waterborne polyurethane resin.

[0035] In a specific embodiment, the polyester polyol includes polyethylene adipate diol, polypropylene adipate diol, polyethylene adipate diol, polyethylene adipate-diethylene glycol adipate diol, polypropylene adipate diol, polycarbonate-1,6-hexanediol adipate diol, or polybutylene adipate diol.

[0036] In a specific embodiment, the chain extender is any one of 1,4-butanediol, propylene glycol, and ethylene glycol.

[0037] In a specific embodiment, the end-capping agent is polystyrene.

[0038] Example 1

[0039] A method for preparing an aqueous polyurethane resin comprises the following steps:

[0040] Step 1: Weigh each component according to weight, mix 20 parts of isophorone diisocyanate, 30 parts of tetraphenyl glycol and 100 parts of polyethylene adipate glycol evenly, and react at 120° C. for 5 hours to obtain a mixture 1;

[0041] Step 2: under stirring at 300 rpm, 15 parts of 1,4-butanediol were added to the mixture 1 and reacted for 1.5 hours, and then 8 parts of polystyrene were added and reacted for 0.5 hours to block the remaining active groups, thereby obtaining a mixture 2;

[0042] Step 3: At a temperature of 40° C., 3 parts of a pH adjuster were added to the mixture 2 to adjust the pH to 8.5, and then 500 parts of deionized water were added for dispersion and emulsification to obtain a waterborne polyurethane resin.

[0043] Example 2-Example 5

[0044] The preparation method of the waterborne polyurethane resin is the same as that of Example 1, except that the formula of the waterborne polyurethane resin is shown in Table 1;

[0045] Table 1

[0046] Components Example 2 Example 3 Example 4 Example 5 Isophorone diisocyanate 25 15 23 16 Polyethylene adipate glycol 100 100 94 108 Tetraphenyl glycol 25 35 33 26 Chain Extender (1,4-Butanediol) 13 18 15 15 Capping agent (polystyrene) 10 5 8 8

[0047] The basic characteristics test and physical and mechanical properties test were carried out on the waterborne polyurethane resins of Examples 1 to 5. The test results are shown in Table 2:

[0048] Table 2

[0049]

[0050]

[0051] As can be seen from Table 2, the 100% modulus of the waterborne polyurethane resin of the present invention is low, and the breaking strength and breaking elongation are both high, indicating that the waterborne polyurethane resin used for the clothing leather of the present invention has good mechanical strength and softness, ensuring the feel of the clothing leather.

[0052] Preparation of clothing leather:

[0053] The waterborne polyurethane resin prepared in Example 1 to Example 5 is respectively mixed with silane coupling agent ZQ-172 (cross-linking agent), RM-2020 (thickener) and red yeast rice coloring (pigment) in a weight ratio of 100:1:5:10 to form a coating; the textile is used as a base fabric, and the bonding strength with the coating is improved through cleaning treatment, and the coating is evenly coated on the base fabric, and dried and cured by a drying device to obtain clothing leather.

[0054] The performance tests were conducted on the garment leathers prepared from the waterborne polyurethane resins of Examples 1 to 5:

[0055] The test results are shown in Table 3:

[0056] Table 3

[0057]

[0058]

[0059] It can be seen from Table 3 that the clothing leather prepared by using the waterborne polyurethane resin provided by the present invention has obvious advantages in wear resistance, folding resistance and cold resistance. By further embossing it, the clothing leather can have unique aesthetics, thereby improving the added value of the product; because the waterborne polyurethane resin has good mechanical properties and softness, it can be used as a coating layer to make the clothing leather soft and comfortable, meeting the comfort requirements.

[0060] The invention is environmentally friendly and non-toxic, and can significantly reduce the amount of organic solvent used during the preparation process, thereby reducing environmental pollution; at the same time, the resin has good film-forming properties and adhesion as a coating, effectively improving the product quality of clothing leather.

[0061] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0062] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A waterborne polyurethane resin, characterized in that The following raw materials are included by weight: 15-25 parts of isophorone diisocyanate, 90-110 parts of polyester polyol, 25-35 parts of tetraphenyl glycol, 10-20 parts of chain extender, 5-10 parts of end-capping agent, 2-4 parts of pH regulator, and 400-600 parts of deionized water.

2. A waterborne polyurethane resin according to claim 1, characterized in that: The polyester polyol includes polyethylene adipate diol, polypropylene adipate diol, polyethylene adipate diol, polyethylene adipate-diethylene glycol ester diol, polypropylene adipate diol, polycarbonate-1,6-hexanediol ester diol or polybutylene adipate diol.

3. The waterborne polyurethane resin according to claim 1, characterized in that: The chain extender is any one of 1,4-butanediol, propylene glycol and ethylene glycol.

4. The waterborne polyurethane resin according to claim 1, characterized in that: The end-capping agent is polystyrene.

5. A method for preparing an aqueous polyurethane resin as claimed in claim 1, characterized in that: The following steps are involved: Step 1: isophorone diisocyanate, tetraphenyl glycol and polyester polyol are mixed evenly, and reacted at 110-130° C. for 4-6 hours to obtain a mixture 1; Step 2: under stirring conditions, add a chain extender to the mixture 1 and react for 1-2 hours, then add a capping agent and continue to react for 0.5-1 hour to obtain a mixture 2; Step 3: At a temperature of 35-45° C., add a pH adjuster to the mixture 2 to adjust the pH to 8-9, and then add deionized water for dispersion and emulsification to obtain a waterborne polyurethane resin.

6. The method for preparing an aqueous polyurethane resin according to claim 5, characterized in that: The stirring speed is 200-400 rpm.

7. A method for applying the waterborne polyurethane resin in garment leather as claimed in claim 1, characterized in that: The following steps are involved: S1. Mixing the waterborne polyurethane resin with a crosslinker, a thickener and a pigment to form a coating; S2. Use the textile as the base fabric, after cleaning, evenly apply the coating on the base fabric, dry and solidify it through drying equipment to obtain clothing leather.

8. The method for applying an aqueous polyurethane resin in garment leather according to claim 7, characterized in that: The weight ratio of the waterborne polyurethane resin, the crosslinking agent, the thickener and the pigment is 100:0.5-2:4-6:8-15.

9. The method for applying an aqueous polyurethane resin in garment leather according to claim 7, characterized in that: The cross-linking agent is silane coupling agent ZQ-172.

10. The method for applying a waterborne polyurethane resin in garment leather according to claim 7, characterized in that: The thickener is RM-2020.

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