Polyurethane resin composition, polyurethane material and application thereof

Abstract

The invention relates to a polyurethane resin composition, a polyurethane material and application of the polyurethane material. The polyurethane resin composition comprises the following components in parts by weight: 100 parts of a blocked polyurethane prepolymer, 4-10 parts of an amine cross-linking agent and 0.1-10 parts of a catalyst, the preparation raw materials of the closed polyurethane prepolymer comprise a combination of an active hydrogen component, isocyanate and a sealing agent; the amine cross-linking agent comprises 4, 4-diaminodicyclohexylmethane (the content of a trans-structure is 13 to 20 percent); the catalyst is organic bismuth. The polyurethane resin composition provided by the invention not only is safe and environment-friendly, but also can be quickly cured, so that the production efficiency is improved; the waterborne polyurethane resin can be used for waterborne PUD, leather slurry and hot melt adhesive, and the obtained polyurethane material has excellent hydrolysis resistance, adhesive force, wear resistance and alcohol wiping resistance at the same time.

Description

Technical Field

[0001] The invention belongs to the field of polyurethane, and specifically relates to a polyurethane resin composition, a polyurethane material and applications thereof. Background Art

[0002] Polyurethane materials use isocyanate as the main raw material, with rich raw material varieties and diverse formula combinations. They have excellent chemical resistance, wear resistance and toughness. They are widely used in rail transportation, electronic devices, coatings, wood, leather and other industries in the form of coatings, adhesives, synthetic leather, elastomers and paving materials. Specifically, they are divided into solvent-based polyurethane, solvent-free two-component polyurethane, water-based polyurethane and closed polyurethane.

[0003] Solvent-based polyurethanes volatilize solvents by high-temperature baking, which pollutes the environment; solvent-free two-component polyurethanes have high viscosity and open NCO requires special equipment and storage; water-based polyurethanes use water instead of solvents to achieve environmental protection, but the comprehensive performance of the product is still somewhat different from that of traditional solvent-based products, especially hydrolysis resistance (for example, Chinese patent CN108779200A); closed polyurethanes can be stored stably at room temperature, and some systems are combined with cross-linking agents and catalysts to obtain products that can be cured quickly at high temperatures, but there are still large internal stresses, and the comprehensive performance cannot meet the requirements (for example, Chinese patent CN109266294A). Therefore, the development of an environmentally friendly, safe, convenient and excellent performance polyurethane resin material is the continuous effort of colleagues in the industry.

[0004] Chinese patent CN 117343267 A provides a leather base prepared from a closed polyurethane composition having high peel strength and excellent heat resistance, low-temperature folding resistance and hydrolysis resistance, and has advanced technology, but its solvent resistance and wear resistance are not obvious. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a polyurethane resin composition, a polyurethane material and its application. The purpose of the present invention is to provide a polyurethane material which is easy to produce, environmentally friendly, has strong adhesion, excellent hydrolysis resistance, alcohol abrasion resistance and wear resistance.

[0006] In order to achieve the above-mentioned invention object, the present invention adopts the following technical scheme:

[0007] A polyurethane resin composition, comprising the following components in parts by weight:

[0008] 100 parts of blocked polyurethane prepolymer, 4-10 parts (e.g., 5, 6, 7, 8, 9 parts) of amine crosslinking agent, 0.1-10 parts (e.g., 0.5, 0.8, 1, 2, 3, 4, 5, 6, 7, 8, 9 parts) of catalyst.

[0009] The raw materials for preparing the closed polyurethane prepolymer include a combination of an active hydrogen component, an isocyanate and a blocking agent; the amine crosslinking agent includes 4,4-diaminodicyclohexylmethane, wherein the content of the trans-trans structure in the 4,4-diaminodicyclohexylmethane is 13 to 20wt%, for example, 14, 15, 16, 17, 18, 19, 20%, etc.; the catalyst is an organic bismuth.

[0010] In the present invention, the catalyst is a tertiary amine or an organometallic compound, for example, tertiary amines such as N,N-dimethylcyclohexylamine, triethylenediamine, N-methylmorpholine, triethanolamine, etc., organotin, organobismuth, organozinc, preferably an organobismuth catalyst, for example, any one or a combination of at least two of BiCAT Z (M), BiCAT 3228 (M), BiCAT 8, and BiCAT 8108 from a leading American chemical company.

[0011] In the present invention, a closed polyurethane prepolymer is used in combination with an amine curing agent of a specific structure and a catalyst, so that: first, a long storage period can be achieved at room temperature, which is convenient for production and environmentally friendly; second, the polyurethane material obtained by unblocking at high temperature has an excellent high-temperature catalytic effect of the organic bismuth catalyst, and has strong adhesion; third, the polyurethane obtained by using 4,4-diaminodicyclohexylmethane (wherein the trans-trans structure is 13-20%) has a large transition state steric hindrance during the hydrolysis process, is less likely to be hydrolyzed, and has excellent hydrolysis resistance, adhesion and alcohol abrasion resistance.

[0012] In the present invention, the raw materials for preparing the blocked polyurethane prepolymer include the following components in parts by mass:

[0013] 45-85 parts of active hydrogen component, for example 46, 50, 55, 60, 65, 70, 75, 80, 85 parts, etc.;

[0014] Chain extender 0-5 parts, for example 1, 2, 3, 4, 5 parts, etc.;

[0015] Cross-linking agent 0-3 parts, for example 0.5, 1, 1.5, 2, 2.5, 3 parts, etc.;

[0016] 15-45 parts of isocyanate component, for example, 15, 18, 21, 24, 27, 30, 33, 36, 40, 42, 45 parts, etc.;

[0017] 3-10 parts of the sealing agent, for example, 3, 4, 5, 6, 7, 8, 9, 10 parts, etc.

[0018] In the present invention, the active hydrogen component includes polyester polyol and / or polyether polyol. Wherein, the polyester polyol includes any one or at least two combinations of polyneopentyl adipate diol, polybutylene adipate diol, polyhexylene adipate diol, polyethylene adipate diol, polymethyl propylene adipate diol, polypropylene adipate diol, polydiethylene adipate diol, polybutylene adipate methyl propylene glycol ester diol or polycaprolactone diol. The polyether polyol includes any one or at least two combinations of polypropylene oxide diol, polyethylene oxide diol, polytetramethylene ether glycol or polymer polyol. The molecular weight of the active hydrogen component is 400-3000, such as 500, 800, 1000, 1500, 2000, 2500, 3000, etc.

[0019] In the present invention, the chain extender includes any one or a combination of at least two of 1,4-butanediol, ethylene glycol, diethylene glycol, propylene glycol, neopentyl glycol, cyclohexanediol, 1,6-hexanediol, 3,3'-dichloro-4,4'-diphenylmethanediamine, 3,5-diethyltoluenediamine, triethanolamine, diethanolamine, methyldiethanolamine, 4,4'-bis-sec-butylaminodiphenylmethane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, and 1,3-cyclohexanediamine.

[0020] In the present invention, the crosslinking agent includes one or a combination of at least two of trimethylolpropane trimethylolethane, pentaerythritol, glycerol, toluenediamine, triisopropanolamine, 4,4'-diaminodicyclohexylmethane, isophoronediamine and 4,4'-bis-sec-butylaminodiphenylmethane.

[0021] In the present invention, the blocking agent includes one or a combination of at least two of methyl ethyl ketone oxime, 3,5-dimethylpyrazole, pyrazole, and glycerol carbonate.

[0022] In the present invention, the isocyanate component includes any one or a combination of at least two of 2,4-toluene diisocyanate, toluene 2,6-diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, and isophorone diisocyanate.

[0023] In the present invention, the preparation method of the blocked polyurethane prepolymer comprises the following steps:

[0024] First, add active hydrogen component and chain extender at 20-45°C and stir for 10-20 minutes, then drop isocyanate component into the flask within 0.5-1 hour and react at 65-85°C for 2-5 hours, then add crosslinking agent and continue to react until NCO content is less than theoretical calculated value, then add blocking agent and react at 70-90°C for 0.5-3 hours to carry out end-capping reaction until NCO content in the system is less than 0.1%, and then cool to room temperature to obtain blocked polyurethane prepolymer.

[0025] In the polyurethane resin composition described in the present application, the blocked polyurethane prepolymer is produced by the reaction of isocyanate and hydroxyl components, has a small molecular weight, low viscosity, and a suitable deblocking temperature, which is conducive to processing.

[0026] On the other hand, a polyurethane material is prepared by curing the aforementioned polyurethane resin composition at 120-150° C. for 2-5 minutes.

[0027] On the other hand, the aforementioned polyurethane resin composition is used in water-based PUD, polyurethane adhesive, and polyurethane leather slurry.

[0028] Compared with the prior art, this application has the following excellent effects:

[0029] The polyurethane composition obtained by the invention has a simple production process and a wide range of applications, and can be cured at 120-150° C. for 1-3 minutes to form a polyurethane material, which can meet the performance requirements of various downstream applications.

[0030] The polyurethane material prepared from the polyurethane composition of the present invention has excellent adhesion, good alcohol abrasion resistance, wear resistance and hydrolysis resistance, and the hydrolysis resistance peeling force retention rate can reach more than 90%. DETAILED DESCRIPTION

[0031] The technical solution of the present application is further described below through specific implementation methods. Those skilled in the art should understand that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present application.

[0032] The main sources of raw materials involved in the following examples are as follows:

[0033]

[0034]

[0035] Example 1

[0036] First, add 55g of polyoxypropylene diol Mn=3000 and 3g of chain extender 1,4-butanediol at 20°C and stir for 10min, then drop 15g of toluene-2,4-diisocyanate into the flask within 30min and react at 70°C for 3 hours, then add 1g of crosslinking agent pentaerythritol and continue to react until the NCO content is less than the theoretical calculated value, then add 4g of blocking agent 3,5-dimethylpyridine and react at 70°C for 3 hours to perform end-capping reaction until the NCO content in the system is less than 0.1%. Then cool to room temperature to obtain a blocked polyurethane prepolymer.

[0037] 100 g of the obtained blocked polyurethane prepolymer was mixed evenly with 6 g of diaminodicyclohexylmethane (13% of the anti-isomer) and 10 g of catalyst DMCHA at 25° C. to obtain a polyurethane resin composition, and the viscosity of the composition was tested.

[0038] The obtained polyurethane resin composition was coated on the polished tinplate through a 300 μm wire rod, and after 24 hours, it was placed in an oven at 130° C. for 4 minutes for baking and curing to obtain a polyurethane material, and the peel strength and peel strength retention rate were tested.

[0039] Example 2

[0040] First, add 45g of polybutylene adipate diol Mn=2000 and 2g of chain extender propylene glycol at 30°C and stir for 20min, then drop 20g of 4,4'-diisocyanate diphenylmethane into the flask within 45min and react at 65°C for 5 hours, then add 2g of crosslinking agent toluene diamine and continue to react until the NCO content is less than the theoretical calculated value, then add 3g of blocking agent 3,5-dimethylpyrazole and react at 90°C for 0.5h to perform end-capping reaction until the NCO content in the system is less than 0.1%. Then cool to room temperature to obtain a blocked polyurethane prepolymer.

[0041] 100 g of the obtained blocked polyurethane prepolymer was mixed evenly with 4.7 g of diaminodicyclohexylmethane (16% of the anti-isomer) and 8 g of zinc isooctanoate as a catalyst at 30° C. to obtain a polyurethane resin composition, and the viscosity of the composition was tested.

[0042] The obtained polyurethane resin composition was coated on the polished tinplate through a 300 μm wire rod, and after 24 hours, it was placed in an oven at 150° C. for 2 minutes for baking and curing to obtain a polyurethane material.

[0043] Example 3

[0044] First, add 35g of polypropylene oxide diol Mn=400, 35g of polypropylene adipate diol Mn=2000 and 1g of ethanolamine at 45°C and stir for 14min, then drop 45g of 4,4-diisocyanate dicyclohexylmethane into the flask within 60min and react at 85°C for 2 hours, then add 3g of crosslinking agent isophorone diamine and continue to react until the NCO content is less than the theoretical calculated value, then add 9.2g of blocking agent methyl ethyl ketone oxime and react at 80°C for 1.5 hours to perform end-capping reaction until the NCO content in the system is less than 0.1%. Then cool to room temperature to obtain a blocked polyurethane prepolymer.

[0045] 100 g of the obtained blocked polyurethane prepolymer was mixed with 9.3 g of diaminodicyclohexylmethane (20% of the inverse isomer) and 0.5 g of catalyst bismuth isooctanoate BiCAT 8210 at 35° C. to obtain a polyurethane resin composition. The viscosity and gel time of the composition at 120° C. were tested.

[0046] The obtained polyurethane resin composition was coated on the polished tinplate through a 300 μm wire rod, and after 24 hours, it was placed in an oven at 140° C. for 5 minutes for baking and curing to obtain a polyurethane material.

[0047] Example 4

[0048] First, add 60g of polyethylene adipate glycol Mn=1000 and 20g of polypropylene oxide glycol Mn=500 at 35°C and stir for 18min, then drop 40g of isophorone diisocyanate into the flask within 50min and react at 75°C for 4 hours, then add 5g of chain extender 4,4'-bis-sec-butylaminodiphenylmethane and continue to react until the NCO content is less than the theoretical calculated value, then add 7.3g of blocking agent methyl ethyl ketone oxime and react at 75°C for 2 hours to perform end-capping reaction until the NCO content in the system is less than 0.1%. Then cool to room temperature to obtain a blocked polyurethane prepolymer.

[0049] 100 g of the obtained blocked polyurethane prepolymer was mixed evenly with 7.1 g of diaminodicyclohexylmethane (13% of the anti-isomer) and 5 g of dibutyltin dilaurate as a catalyst at 25° C. to obtain a polyurethane resin composition, and the viscosity of the composition was tested.

[0050] The obtained polyurethane resin composition was coated on the polished tinplate through a 300 μm wire rod, and after 24 hours, it was placed in an oven at 120° C. for 5 minutes for baking and curing to obtain a polyurethane material, and the peel strength and peel strength retention rate were tested.

[0051] Comparative Example 1

[0052] The 6 g of diaminodicyclohexylmethane (13% of the trans-isomer) in Example 1 was replaced by 6 g of diaminodicyclohexylmethane (23% of the trans-isomer), and the other substances and conditions remained unchanged.

[0053] Comparative Example 2

[0054] The 6 g of diaminodicyclohexylmethane (13% of the trans-isomer) in Example 1 was replaced by 6 g of diaminodicyclohexylmethane (11% of the trans-isomer), and the other substances and conditions remained unchanged.

[0055] Comparative Example 3

[0056] The 6 g of diaminodicyclohexylmethane (13% of the trans-isomer) in Example 1 was replaced with the same molar amount of isophoronediamine, and the other substances and conditions remained unchanged.

[0057] Test method:

[0058] The NCO content was tested by a point titrator according to GB / T 12009.4-2006; the viscosity of the polyurethane composition was tested according to GB / T 10247-2008; the unsealing temperature of the polyurethane resin composition was tested by the DSC method, with a heating rate of 10°C / min; the surface drying time of the paint film was tested according to GB / T 1728-2020; the adhesion was tested according to the national standard GB / T9286-88 "Scratch test of paint and varnish film"; the alcohol resistance of the paint film was tested according to ASTM D 5402 to see how many times the paint film needs to be damaged after being wiped with ethanol; the wear resistance of the polyurethane material was tested according to GB / T1768-2006; the initial peel strength was tested according to GB / T 2792-2014, the polyurethane material sample was placed at 70°C / 95% humidity for 5 weeks, the peel force was tested again, and the peel force retention rate was calculated.

[0059] The performance test results of the polyurethane materials of the embodiments and comparative examples are shown in the following table:

[0060]

[0061]

[0062] As can be seen from the above table, the polyurethane resin composition provided by the present invention has a low viscosity, an appropriate unblocking temperature, can be quickly cured at an appropriate temperature, and has a high peeling force after being fully cured. Comparative Example 1 and Comparative Example 2 can be compared with Examples 1-4 to show that the content of the anti-antibody diaminodicyclohexylmethane is within the range of 13% to 20%, the viscosity of the polyurethane composition is lower, the operating performance is better, the adhesion, alcohol rubbing resistance, wear resistance and initial peeling strength of the obtained polyurethane material are excellent, and the peeling retention rate after experiencing a high humidity environment is higher, and the water resistance is better. Comparative Example 3 can be compared with Examples 1-4 to show that the polyurethane composition obtained by using diaminodicyclohexylmethane as an amine crosslinking agent has an appropriate viscosity and better processability, and the adhesion, alcohol rubbing resistance, wear resistance and initial peeling strength of the obtained polyurethane material are excellent, and the peeling retention rate after experiencing a high humidity environment is higher, and the water resistance is better.

Claims

1. A polyurethane resin composition, characterized in that The polyurethane resin composition comprises the following components in parts by weight: 100 parts of blocked polyurethane prepolymer; 4-10 parts of amine cross-linking agent; Catalyst 0.1-10 parts; The raw materials for preparing the blocked polyurethane prepolymer include a combination of an active hydrogen component, an isocyanate and a blocking agent; the catalyst is a tertiary amine or an organic metal compound; The amine cross-linking agent includes 4,4-diaminodicyclohexylmethane, wherein the content of the trans-trans structure in the 4,4-diaminodicyclohexylmethane is 13-20 wt %.

2. The polyurethane resin composition according to claim 1, characterized in that The raw materials for preparing the blocked polyurethane prepolymer include the following components in parts by mass:

3. The polyurethane resin composition according to claim 2, characterized in that The active hydrogen component includes polyester polyol and / or polyether polyol; Preferably, the polyester polyol comprises any one or a combination of at least two of polyneopentyl adipate diol, polybutylene adipate diol, polyhexane adipate diol, polyethylene adipate diol, polymethylpropylene adipate diol, polypropylene adipate diol, polydiethylene adipate diol, polybutylene adipate methylpropylene glycol ester diol or polycaprolactone diol; and / or The polyether polyol includes any one or a combination of at least two of polypropylene oxide glycol, polyethylene oxide glycol, polytetramethylene ether glycol or polymer polyol; More preferably, the molecular weight of the active hydrogen component is 400-3000.

4. The polyurethane resin composition according to claim 2, characterized in that The chain extender includes any one or a combination of at least two of 1,4-butanediol, ethylene glycol, diethylene glycol, propylene glycol, neopentyl glycol, cyclohexanediol, 1,6-hexanediol, 3,3'-dichloro-4,4'-diphenylmethanediamine, 3,5-diethyltoluenediamine, triethanolamine, diethanolamine, methyldiethanolamine, 4,4'-bis-sec-butylaminodiphenylmethane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, and 1,3-cyclohexanediamine.

5. The polyurethane resin composition according to claim 2, characterized in that: The crosslinking agent includes one or a combination of at least two of trimethylolpropane, trimethylolethane, pentaerythritol, glycerol, toluenediamine, triisopropanolamine, 4,4'-diaminodicyclohexylmethane, isophoronediamine and 4,4'-bis-sec-butylaminodiphenylmethane.

6. The polyurethane resin composition according to claim 2, characterized in that: The blocking agent includes one or a combination of at least two of methyl ethyl ketone oxime, 3,5-dimethylpyrazole, pyrazole, and glycerol carbonate.

7. The polyurethane resin composition according to claim 2, characterized in that: The isocyanate component includes any one of 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, and isophorone diisocyanate, or a combination of at least two thereof.

8. The polyurethane resin composition according to claim 1, characterized in that The preparation method of the blocked polyurethane prepolymer comprises the following steps: First, add active hydrogen component and chain extender at 20-45°C and stir for 10-20 minutes, then add isocyanate component to the flask within 0.5-1 hour and react at 65-85°C for 2-5 hours, then add crosslinker and continue to react until NCO content is less than theoretical calculated value, then add blocking agent and react at 70-90°C for 0.5-3 hours to perform end-capping reaction until NCO content in the system is less than 0.1%, and then cool to room temperature to obtain blocked polyurethane prepolymer.

9. A polyurethane material, characterized in that: The polyurethane material is prepared by curing the polyurethane resin composition according to any one of claims 1 to 8 at 120 to 150° C. for 2 to 5 minutes.

10. Use of the polyurethane resin composition according to any one of claims 1 to 8 in water-based PUD, polyurethane adhesive, and polyurethane leather slurry.

Images