Environment-friendly waterborne polyurethane glove and preparation method thereof

Abstract

The invention discloses an environment-friendly waterborne polyurethane glove and a preparation method thereof. The environment-friendly waterborne polyurethane glove comprises a glove core and an environment-friendly waterborne polyurethane layer wrapping the surface layer of the glove core. The environment-friendly waterborne polyurethane layer is prepared from the following raw materials in parts by mass: 20 to 35 parts of isocyanate, 40 to 60 parts of bio-based polyol, 3 to 8 parts of a fluorine-containing chain extender, 0.5 to 3 parts of nano cellulose, 1 to 5 parts of an environment-friendly cross-linking agent, 0.3 to 1.5 parts of a nonionic emulsifier, 2 to 6 parts of an environment-friendly plasticizer, 0.1 to 0.5 part of a low-toxicity preservative and 15 to 30 parts of deionized water. The preparation method has the advantages that no organic solvent is contained, no VOCs are discharged in the production process, the green chemistry principle is met, and the overall strength and performance are higher.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of labor protection gloves, in particular to an environmentally friendly water-based polyurethane glove and a preparation method thereof. BACKGROUND

[0002] Water-based polyurethane labor protection gloves gradually replace traditional solvent gloves due to the advantages of no organic solvent pollution, soft fit, etc., and are widely used in labor protection scenes such as mechanical manufacturing, automobile repair, chemical operation, etc. However, the water-based polyurethane labor protection gloves in the prior art have obvious adaptability defects: Insufficient wear resistance: frequent contact with hard objects such as metal and sandstone in industrial operation, the existing product has a low Martin Dale wear resistance of less than 30,000 times, and a short service life; Poor oil resistance: after contacting with oil such as machine oil and lubricating oil, the glove is prone to swelling and serious mechanical property degradation (the strength retention rate is usually less than 70%); Unbalanced mechanical properties: simply pursuing strength leads to stiff hand feeling, affecting operation flexibility, and considering softness leads to insufficient strength; Environmental hazards: some formulations still use cross-linking agents containing formaldehyde, phthalate plasticizers, etc., and the VOC content is high, which may harm the health of workers during long-term wearing.

[0003] In the prior art, the improvement schemes are mostly focused on single modification: such as only adding nano fillers to enhance strength, but the performance is unstable due to easy agglomeration; or only using bio-based raw materials to improve environmental protection, but the oil resistance and wear resistance are not improved. SUMMARY

[0004] The purpose of the present application is to provide an environmentally friendly water-based polyurethane glove and a preparation method thereof, which do not contain organic solvents, have no VOC emissions in the production process, comply with the principles of green chemistry, and have stronger overall strength and performance.

[0005] The above technical purpose of the present application is achieved by the following technical scheme: An environmentally friendly water-based polyurethane glove, comprising a glove core and an environmentally friendly water-based polyurethane layer wrapped on the surface of the glove core, the environmentally friendly water-based polyurethane layer comprising the following raw materials by mass: isocyanate 20-35 parts, bio-based polyol 40-60 parts, fluorine-containing chain extender 3-8 parts, nano-cellulose 0.5-3 parts, environmentally friendly cross-linking agent 1-5 parts, non-ionic emulsifier 0.3-1.5 parts, environmentally friendly plasticizer 2-6 parts, low-toxicity preservative 0.1-0.5 parts, and deionized water 15-30 parts.

[0006] Preferably, the isocyanate is selected from one or more of isophorone diisocyanate, hexamethylene diisocyanate, and lysine diisocyanate, wherein the NCO content is 15-25 wt%.

[0007] Preferably, the bio-based polyol is selected from one or more of castor oil polyol, soybean oil polyol, polylactic acid polyol or polycaprolactone polyol, with a hydroxyl value of 50-250 mg KOH / g.

[0008] Preferably, the fluorine-containing chain extender is a terminal hydroxyl-containing fluorine-containing chain extender, and the preparation method is as follows: under nitrogen protection, hexafluorobutyl methacrylate and diethanolamine are reacted at a molar ratio of 1:1-1:1.2 at 60-80°C for 3-5 hours to obtain a terminal hydroxyl-containing fluorine-containing chain extender.

[0009] Preferably, the nanocellulose is carboxymethylated nanocellulose with a diameter of 50-100 nm and a crystallinity of ≥75%.

[0010] Preferably, the environmentally friendly crosslinking agent is selected from one or both of polycarbodiimide crosslinking agent or aziridine crosslinking agent.

[0011] Preferably, the non-ionic emulsifier is selected from one or both of polyoxyethylene sorbitan monolaurate or polyoxyethylene octyl phenyl ether.

[0012] Preferably, the environmentally friendly plasticizer is one or both of tributyl citrate or acetyl tributyl citrate.

[0013] Preferably, the low-toxicity preservative is one or both of phenoxyethanol or hydroxybenzoate.

[0014] A preparation method of an environmentally friendly water-based polyurethane glove, comprising the following steps: (1) Preparation of a prepolymer: bio-based polyol, isocyanate and fluorine-containing chain extender are reacted at 70-80°C for 2-3 hours to obtain a prepolymer with an NCO content of 5-10 wt%; (2) Emulsification: the prepolymer is cooled to 40-50°C, non-ionic emulsifier, deionized water and environmentally friendly plasticizer are added, and high-speed dispersion is carried out at 2000-3000 rpm for 10-20 minutes to obtain a water-based polyurethane emulsion with a solid content of 30-40 wt%; (3) Crosslinking: low-toxicity preservative, environmentally friendly crosslinking agent and nanocellulose are added to the emulsion, and dispersion is carried out at an ultrasonic power of 200-400 W for 10-20 minutes to obtain an environmentally friendly water-based polyurethane dispersion; (4) Glove forming: the glove core is placed in an oven and heated to 40-50°C, immersed in the environmentally friendly water-based polyurethane dispersion, the dipping time is 4-10 s, after taking out, pre-drying is carried out at 65-75°C for 20-0 min, vulcanization is carried out at 105-125°C for 25-40 min, and after natural cooling to room temperature, demolding is carried out to obtain an environmentally friendly water-based polyurethane labor protection glove.

[0015] In conclusion, the present application has the following advantages: the present application uses water as solvent completely, does not contain organic solvent, and has no VOCs emission in the production process, which meets the principle of green chemistry; by optimizing the combination of polyols and introducing fluorine-containing chain extender, the tensile strength of the glove reaches more than 15 MPa, the elongation at break reaches more than 450%, and the wear resistance is also stronger; the introduction of fluorine-containing chain segment reduces the surface energy of the material, so that the glove has a lower friction coefficient, and is more comfortable to wear and use; the fluorine-containing chain segment in the polyurethane molecule and the dense phase separation structure make the glove have excellent oil resistance, solvent resistance and weak acid and weak base resistance. DETAILED DESCRIPTION

[0016] The specific embodiments of the present application are further described below, and the embodiments do not constitute a limitation on the present application.

[0017] An environmentally friendly water-based polyurethane glove comprises a glove core and an environmentally friendly water-based polyurethane layer wrapped on the surface layer of the glove core, and the environmentally friendly water-based polyurethane layer comprises the following raw materials in mass parts: isocyanate 20-35 parts, bio-based polyol 40-60 parts, fluorine-containing chain extender 3-8 parts, nano-cellulose 0.5-3 parts, environmentally friendly crosslinking agent 1-5 parts, non-ionic emulsifier 0.3-1.5 parts, environmentally friendly plasticizer 2-6 parts, low-toxicity preservative 0.1-0.5 parts, and deionized water 15-30 parts.

[0018] The isocyanate is selected from one or more of isophorone diisocyanate, hexamethylene diisocyanate, and lysine diisocyanate, wherein the NCO content is 15-25 wt%.

[0019] The bio-based polyol is selected from one or more of castor oil polyol, soybean oil polyol, polylactic acid polyol, or polycaprolactone polyol, and the hydroxyl value is 50-250 mg KOH / g.

[0020] The fluorine-containing chain extender is a hydroxyl-terminated fluorine-containing chain extender, and the preparation method is as follows: under nitrogen protection, hexafluorobutyl methacrylate and diethanolamine are reacted at a molar ratio of 1:1-1:1.2 at 60-80°C for 3-5 hours to obtain the hydroxyl-terminated fluorine-containing chain extender.

[0021] The nano-cellulose is carboxymethylated nano-cellulose, with a diameter of 50-100 nm and a crystallinity of ≥75%.

[0022] The environmentally friendly crosslinking agent is selected from one or both of polycarbodiimide crosslinking agent or aziridine crosslinking agent.

[0023] The non-ionic emulsifier is selected from one or both of polyoxyethylene sorbitan monolaurate or polyoxyethylene octyl phenyl ether.

[0024] The environmentally friendly plasticizer is one or both of tributyl citrate or acetyl tributyl citrate.

[0025] The low-toxicity preservative is one or both of phenoxyethanol or methylparaben.

[0026] A preparation method of an environmentally friendly water-based polyurethane glove comprises the following steps: (1) Prepolymer preparation: bio-based polyol, isocyanate and fluorine-containing chain extender are reacted at 70-80°C for 2-3 hours to obtain a prepolymer with a NCO content of 5-10wt%; (2) Emulsification: the prepolymer is cooled to 40-50°C, non-ionic emulsifier, deionized water and environmentally friendly plasticizer are added, and high-speed dispersion is carried out at 2000-3000 rpm for 10-20 minutes to obtain a water-based polyurethane emulsion with a solid content of 30-40wt%; (3) Crosslinking: low-toxicity preservative, environmentally friendly crosslinking agent and nano-cellulose are added to the emulsion, and dispersion is carried out at an ultrasonic power of 200-400W for 10-20 minutes to obtain an environmentally friendly water-based polyurethane dispersion; (4) Glove forming: the glove core is placed in an oven and heated to 40-50°C, immersed in the environmentally friendly water-based polyurethane dispersion, the dipping time is 4-10s, and after taking out, pre-drying is carried out at 65-75°C for 20-0min, vulcanization is carried out at 105-125°C for 25-40min, and after natural cooling to room temperature, demolding is carried out to obtain an environmentally friendly water-based polyurethane labor protection glove.

[0027] Example 1 The environmentally friendly water-based polyurethane layer comprises the following mass parts of raw materials: isophorone diisocyanate 25 parts, castor oil polyol 45 parts, hydroxyl-terminated fluorine-containing chain extender 5 parts, carboxymethylated nano-cellulose 2 parts, aziridine crosslinking agent 2 parts, polyoxyethylene sorbitan monolaurate 0.9 parts, tributyl citrate 3 parts, methylparaben 0.1 part, and deionized water 20 parts.

[0028] Example 2 The environmentally friendly water-based polyurethane layer comprises the following mass parts of raw materials: hexamethylene diisocyanate 26 parts, polylactic acid polyol 45 parts, hydroxyl-terminated fluorine-containing chain extender 5 parts, carboxymethylated nano-cellulose 2 parts, polycarbodiimide crosslinking agent 2 parts, polyoxyethylene octylphenyl ether 1.2 parts, acetyl tributyl citrate 6 parts, methylparaben 0.4 parts, and deionized water 15 parts.

[0029] Example 3 The environmentally friendly water-based polyurethane layer comprises the following mass parts of raw materials: isophorone diisocyanate 30 parts, castor oil polyol 55 parts, hydroxyl-terminated fluorine-containing chain extender 6 parts, carboxymethylated nano-cellulose 1 part, environmentally friendly polycarbodiimide crosslinking agent 1 part, polyoxyethylene sorbitan monolaurate 1 part, tributyl citrate 5 parts, phenoxyethanol 0.3 parts, and deionized water 30 parts.

[0030] Example 4 The environment-friendly water-based polyurethane layer comprises the following raw materials by mass: lysine diisocyanate 35 parts, polycaprolactone polyol 60 parts, hydroxyl-terminated fluorine-containing chain extender 8 parts, carboxymethylated nanocellulose 3 parts, environment-friendly polycarbodiimide crosslinking agent 5 parts, polyoxyethylene sorbitan monolaurate 1.5 parts, acetyl citric acid tributyl ester 6 parts, hydroxybenzoic acid ester 0.5 parts, and deionized water 15 parts.

[0031] Comparative Example 1 The hydroxyl-terminated fluorine-containing chain extender in Example 1 is replaced with the hydrophilic chain extender dimethylol propanoic acid, and no carboxymethylated nanocellulose is added, and the rest is the same as Example 1.

[0032] Comparative Example 2 The hydroxyl-terminated fluorine-containing chain extender in Example 1 is replaced with the hydrophilic chain extender dimethylol butanoic acid, and no carboxymethylated nanocellulose is added, and the rest is the same as Example 1.

[0033] The gloves obtained in the above examples and comparative examples are subjected to performance testing, and the specific test results are shown in Table 1 below: Table 1

[0034] As can be seen from the detection data in Table 1, since the present application completely uses water as a solvent and does not contain organic solvents, the production process has no VOCs emission, which meets the principles of green chemistry. By optimizing the polyol combination and introducing a fluorine-containing chain extender, the tensile strength of the glove reaches more than 15 MPa, the elongation at break reaches more than 450%, and the wear resistance is also stronger. The introduction of the fluorine-containing chain segment reduces the surface energy of the material, so that the glove has a lower friction coefficient, and is more comfortable to wear and use. The fluorine-containing chain segment in the polyurethane molecule and the dense phase separation structure make the glove have excellent oil resistance, solvent resistance and weak acid and weak base resistance.

[0035] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Those skilled in the art can make various modifications or equivalent replacements to the present application within the spirit and protection scope of the present application, and such modifications or equivalent replacements shall also be considered to fall within the protection scope of the technical solutions of the present application.

Claims

1. An environmentally friendly water-based polyurethane glove, characterized in that, The glove includes a glove core and an environmentally friendly waterborne polyurethane layer covering the surface of the glove core. The environmentally friendly waterborne polyurethane layer comprises the following raw materials in parts by weight: 20-35 parts isocyanate, 40-60 parts bio-based polyol, 3-8 parts fluorinated chain extender, 0.5-3 parts nanocellulose, 1-5 parts environmentally friendly crosslinking agent, 0.3-1.5 parts nonionic emulsifier, 2-6 parts environmentally friendly plasticizer, 0.1-0.5 parts low-toxicity preservative, and 15-30 parts deionized water.

2. The environmentally friendly water-based polyurethane glove according to claim 1, characterized in that: The isocyanate is selected from one or more of isophorone diisocyanate, hexamethylene diisocyanate, and lysine diisocyanate, wherein the NCO content is 15-25 wt%.

3. The environmentally friendly waterborne polyurethane glove according to claim 1, characterized in that: The bio-based polyol is selected from one or more of castor oil polyol, soybean oil polyol, polylactic acid polyol or polycaprolactone polyol, with a hydroxyl value of 50~250 mg KOH / g.

4. The environmentally friendly water-based polyurethane glove according to claim 1, characterized in that: The fluorinated chain extender is a hydroxyl-terminated fluorinated chain extender, and the preparation method is as follows: under nitrogen protection, hexafluorobutyl methacrylate and diethanolamine are reacted at a molar ratio of 1:1 to 1:1.2 at 60 to 80°C for 3 to 5 hours to obtain the hydroxyl-terminated fluorinated chain extender.

5. The environmentally friendly waterborne polyurethane glove according to claim 1, characterized in that: The nanocellulose is carboxymethylated nanocellulose with a diameter of 50~100nm and a crystallinity of ≥75%.

6. The environmentally friendly waterborne polyurethane glove according to claim 1, characterized in that: The environmentally friendly crosslinking agent is selected from one or both of polycarbodiimide crosslinking agents and aziridine crosslinking agents.

7. The environmentally friendly water-based polyurethane glove according to claim 1, characterized in that: The nonionic emulsifier is selected from one or both of polyoxyethylene sorbitan monolaurate or polyoxyethylene octylphenyl ether.

8. The environmentally friendly waterborne polyurethane glove according to claim 1, characterized in that: The environmentally friendly plasticizer is one or both of tributyl citrate or acetylated tributyl citrate.

9. The environmentally friendly waterborne polyurethane glove according to claim 1, characterized in that: The low-toxicity preservative is one or both of phenoxyethanol or methylparaben.

10. A method for preparing an environmentally friendly waterborne polyurethane glove according to any one of claims 1 to 9, characterized in that, Includes the following steps: (1) Preparation of prepolymer: Bio-based polyol, isocyanate and fluorinated chain extender are reacted at 70~80℃ for 2~3 hours to obtain a prepolymer with NCO content of 5~10wt%; (2) Emulsification: Cool the prepolymer to 40~50℃, add nonionic emulsifier, deionized water and environmentally friendly plasticizer, disperse at high speed of 2000~3000rpm for 10~20 minutes to obtain an aqueous polyurethane emulsion with a solid content of 30~40wt%. (3) Crosslinking: Add low-toxicity preservatives, environmentally friendly crosslinking agents and nanocellulose to the emulsion, and disperse it under ultrasonic power of 200~400W for 10~20 minutes to obtain an environmentally friendly waterborne polyurethane dispersion; (4) Glove molding: Place the glove core in an oven and bake it to 40℃~50℃. Immerse it in environmentally friendly water-based polyurethane dispersion for 4~10s. After taking it out, pre-dry it at 65~75℃ for 20~0min. Then vulcanize it at 105~125℃ for 25~40min. After naturally cooling to room temperature, demold to obtain environmentally friendly water-based polyurethane work gloves.

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