WO2022116748A1 - Solvent-free blocked polyurethane resin composition, polyurethane material, and leather product - Google Patents

Abstract

The present application relates to a solvent-free blocked polyurethane resin composition, a polyurethane material, and a leather product. The solvent-free blocked polyurethane resin composition comprises the following components in parts by weight: 100 parts of a blocked polyurethane prepolymer, 4-13 parts of an amine curing agent, and 0.1-10 parts of a temperature-sensitive catalyst. The amine curing agent comprises any one or a combination of at least two of 3,3-dimethyl-4,4-diaminodicyclohexylmethane, 4,4-diaminodicyclohexylmethane, or isophorone diamine. The solvent-free blocked polyurethane resin composition provided by the present application is safe and environment-friendly, and can be quickly cured at relatively low temperature, thereby improving the production efficiency, and reducing the energy consumption; moreover, the solvent-free blocked polyurethane resin composition has excellent peel force, peel force retention rate and hydrolysis resistance.

Description

A solvent-free closed type polyurethane resin composition, polyurethane material and leather product technical field

The present application relates to the technical field of polyurethane, and in particular, to a solvent-free sealed polyurethane resin composition, a polyurethane material and a leather product.

Background technique

Polyurethane resin is synthesized from polyols, chain extenders, crosslinking agents, isocyanates, etc. as the main raw materials under certain process conditions. It is widely used in aviation, electronic devices, coatings, wood, leather and other industries. It can be divided into four major categories. First, the solvent-based polyurethane resin is baked and cured by replacing the solvent with water or evaporating the solvent at high temperature, which causes pollution to the environment; second, the water-based polyurethane uses water as the dispersion medium to replace the solvent to achieve environmental protection, but the cost Higher, the performance of hydrolysis resistance and weather resistance is worse than that of solvent-based polyurethane resin; thirdly, solvent-free two-component polyurethane resin requires special equipment to meet the application, and the open NCO group makes the product storage requirements strict, and product performance is not good. Stablize. Fourth, the closed polyurethane resin can be stored stably, but most products on the market have a small amount of solvent, and there are also problems of high curing temperature and long curing time in the application process.

CN101812228A discloses an all-toluene solvent-based polyurethane resin and a preparation method thereof. Based on the weight percentage of the all-toluene solvent-based polyurethane resin, the content of polyurethane is 34%-36%, and the content of toluene is 64%-66%, excluding other Therefore, the activated carbon toluene recovery system can be used to recover toluene, which overcomes the disadvantage that the solvent-based polyurethane resin on the market cannot be used to recover toluene using the activated carbon toluene recovery system because it contains multiple solvent combinations instead of a single solvent, and the economic benefits are improved. And conducive to environmental protection. This scheme can only improve the pollution problem to a certain extent, but cannot completely avoid it. With the attention of all walks of life on the problem of environmental pollution, this scheme can no longer meet the existing requirements.

CN109266294A discloses a closed-type polyurethane adhesive and a preparation method thereof. The preparation method includes: synthesis of closed-type isocyanate and preparation of closed-type polyurethane adhesive. Diphenylmethane diisocyanate (MDI) is selected as a raw material to invent a Synthesis of MDI-blocked polyurethane. MDI closed polyurethane can be compounded with traditional white latex in proportion to prepare closed polyurethane adhesive. The plywood pressed with the adhesive has good bonding strength and no formaldehyde emission. It has the advantages of cost reduction and environmental friendliness, and can be used as an adhesive for interior materials. However, the adhesive has problems of high curing temperature, long curing time and low efficiency during application.

Therefore, it is extremely important to develop a fast-curing and solvent-free closed-type polyurethane resin, which is not only safe and environmentally friendly, but also can be quickly cured at a lower temperature, which can improve production efficiency and reduce energy consumption. It also has excellent peel strength and water resistance. solution and weatherability.

SUMMARY OF THE INVENTION

The present application provides a solvent-free sealed polyurethane resin composition, a polyurethane material and a leather product; wherein, the solvent-free sealed polyurethane resin composition is not only safe and environmentally friendly, but also can be rapidly cured at a lower temperature, making production Increased efficiency and reduced energy consumption, with excellent peel force, peel force retention and hydrolysis resistance.

In a first aspect, the present application provides a solvent-free sealed polyurethane resin composition, the solvent-free sealed polyurethane resin composition comprises the following components according to parts by weight:

100 copies of closed polyurethane prepolymer;

4-13 parts of amine curing agent; and

0.1-10 copies of temperature-sensitive catalyst;

Wherein, the amine curing agent includes 3,3-dimethyl-4,4-diaminodicyclohexylmethane (DMDC), 4,4-diaminodicyclohexylmethane (PACM) or isophorone di Any one or a combination of at least two of the amines (IPDA).

The addition amount of the amine curing agent is 4-13 parts, such as 5 parts by weight, 6.2 parts by weight, 6.3 parts by weight, 6.5 parts by weight, 7.1 parts by weight, 8.3 parts by weight, 8.9 parts by weight, etc.; the temperature-sensitive catalyst The added amount is 0.1-10 parts, such as 0.1 parts by weight.

In this application, a specific type of amine curing agent and a temperature-sensitive catalyst are used in the solvent-free closed polyurethane system. DMDC, PACM or IPDA have the characteristics of high hardness, strong rigidity, high primary amino activity and high curing strength. The temperature-sensitive catalyst is used in combination, and the reactive group can be quickly activated after proper temperature rise, so as to realize the rapid curing of the polyurethane resin at low temperature, and the obtained polyurethane resin has excellent peeling force, peeling force retention rate and hydrolysis resistance.

In addition, the applicant found in research that the addition amount of amine curing agent must be controlled in the range of 4-13 parts, in order to obtain the above beneficial effects, the addition amount is less than 4 parts, which will lead to low peeling force of the product; the addition amount is more than 13 parts, It will cause the peeling force of the product to be seriously attenuated under high temperature and high humidity. Similarly, the temperature-sensitive catalyst must be controlled within the range of 0.1-10 parts. If the addition amount is less than 0.1 part, the curing efficiency will be reduced; if the addition amount is more than 10 parts, it will lead to abnormal viscosity increase, making it difficult to do normal ingredients, and the product peeling force will be reduced.

Preferably, the amine curing agent includes 3,3-dimethyl-4,4-diaminodicyclohexylmethane.

In this application, DMDC is preferred as the curing agent. The curing agent has the characteristics of high hardness and good temperature resistance. Compared with IPDA and PACM, the obtained product has high strength after curing and can better maintain peeling under high temperature and high humidity conditions. force.

In this application, a temperature-sensitive catalyst refers to a catalyst that has little catalytic effect at room temperature, and can rapidly catalyze active functional groups at elevated temperature.

Preferably, the temperature-sensitive catalyst includes organic bismuth catalyst and/or organic amine catalyst.

Preferably, the temperature-sensitive catalyst comprises any one or a combination of at least two of BiCAT Z(M), BiCAT 3228(M), BiCAT 8, BiCAT 8108 or polycat SA8, and the BiCAT Z(M), BiCAT 3228(M), BiCAT 8, BiCAT 8108 are from leading chemical companies in the United States, and the polycat SA8 is from Evonik Specialty Chemicals (Shanghai) Co., Ltd.

Preferably, the addition amount of the amine curing agent is 8-12 parts. The addition amount of amine curing agent is controlled within this range, which can further improve the comprehensive performance of low temperature curing rate, peel force, peel force retention rate and hydrolysis resistance.

Preferably, the temperature-sensitive catalyst is added in an amount of 0.1-2 parts. The addition amount of the temperature-sensitive catalyst is controlled within this range, which can further improve the comprehensive performance of low temperature curing rate, peel force, peel force retention rate and hydrolysis resistance.

Preferably, the raw materials for preparing the blocked polyurethane prepolymer include a combination of polyol and isocyanate.

Preferably, the raw materials for the preparation of the blocked polyurethane prepolymer further include a synergist and/or a blocking agent.

Preferably, the synergist includes γ-aminopropyltriethoxysilane (KH550).

In the preferred technical solution of the present application, KH550 is used as a synergist, which can be coupled under high temperature and high humidity conditions, resulting in self-crosslinking and improving hydrolysis resistance, especially maintaining high peeling force under high temperature and high humidity, thereby further The high peel strength, peel force retention and hydrolysis resistance of the solvent-free blocked polyurethane resin composition are improved.

Preferably, the blocking agent includes pyrazole compounds, preferably 3,5-dimethylpyrazole and/or pyrazole, more preferably 3,5-dimethylpyrazole.

In another preferred technical solution of the present application, 3,5-dimethylpyrazole is preferably used as the sealing agent, which not only protects -NCO, can be stored stably, but also further improves the low-temperature curing rate, and the semi-dry lamination operation is controllable Sex is high.

Preferably, the raw materials for preparing the closed polyurethane prepolymer further include any one or a combination of at least two of a chain extender, a crosslinking agent or a leveling agent.

Preferably, the preparation raw materials of the closed polyurethane prepolymer include the following components according to mass percentage:

Preferably, the preparation raw materials of the closed polyurethane prepolymer include the following components according to mass percentage:

Preferably, the polyols include polyester polyols and/or polyether polyols.

The polyester polyol is a polyester structure containing two terminal hydroxyl groups, and the polyether polyol is an ether structure containing two or three terminal hydroxyl groups.

Preferably, the molecular weight of the polyol is 250-10000, such as 1000, 2000, 3000, 4000, 6000, 8000 and the like.

Preferably, the polyester polyol comprises polyneopentyl adipate diol (PNA), poly-1,4-butanediol adipate diol (PBA), poly-1 adipate diol (PBA) ,6-Hexanediol diol, polyethylene adipate diol, polymethyltrimethylene adipate diol, polydiethylene adipate diol, or polybutylene adipate diol Any one or a combination of at least two of the methyl propylene glycol ester glycols.

Preferably, the polyether polyol comprises polyoxypropylene glycol (PPG), trifunctional PPG starting with methyl propylene glycol or glycerin, polyoxyethylene glycol (PEG) or polytetramethylene Any one or a combination of at least two of the ether glycols (PTMEG).

Preferably, the polyol is a combination of polyoxypropylene glycol with a molecular weight of 4000, polyoxypropylene glycol with a molecular weight of 2000, and polyoxypropylene glycol with a molecular weight of 1000, and the ratio of the three is 6:2:0.5.

Preferably, the polyol is a combination of polyoxypropylene glycol with a molecular weight of 4000, polyoxypropylene triol with a molecular weight of 6000, and polytetrahydrofuran ether glycol with a molecular weight of 2000, and the ratio of the three is 7:7:1.

Preferably, the polyol is a combination of polyoxypropylene glycol with a molecular weight of 4000, polyoxypropylene glycol with a molecular weight of 8000, and polyneopentyl adipate glycol with a molecular weight of 2000, and the ratio of the three is 4:4 :1.

Preferably, the polyol is a combination of polyoxypropylene glycol with a molecular weight of 4000, polymethyltrimethylene adipate glycol with a molecular weight of 2000, and polyneopentyl adipate glycol with a molecular weight of 4000. The ratio is 10:3:4.

Preferably, the polyol is a combination of polyoxypropylene glycol with a molecular weight of 4000, polyoxypropylene glycol with a molecular weight of 2000, and polyneopentyl adipate glycol with a molecular weight of 2000, and the ratio of the three is 1:3 :3.

Preferably, the polyol is a combination of polyoxypropylene diol with a molecular weight of 2000, polyoxypropylene triol with a molecular weight of 2000, and polyneopentyl adipate diol with a molecular weight of 2000, and the ratio of the three is 4:8 :1.

Preferably, the polyol is a combination of polyoxypropylene glycol with a molecular weight of 2000, polyoxypropylene triol with a molecular weight of 6000, and polyneopentyl adipate glycol with a molecular weight of 2000, and the ratio of the three is 4:8 :1.

Preferably, the polyol is a combination of polyoxypropylene triol with a molecular weight of 3000, polyoxypropylene diol with a molecular weight of 2000, and polyoxypropylene glycol with a molecular weight of 4000, and the ratio of the three is 8:4:3.

Preferably, the polyol is a combination of polyoxypropylene glycol with a molecular weight of 4000 and polyoxypropylene glycol with a molecular weight of 1000, and the ratio of the two is 14:1.

Preferably, the chain extender comprises any one of ethylene glycol (EG), 1,4-butanediol (BDO), neopentyl glycol (NPG) or 1,6-hexanediol (HDO) or at least two combinations.

Preferably, the crosslinking agent comprises trimethylolpropane (TMP) and/or glycerol.

Preferably, the isocyanate includes any one or a combination of at least two of toluene-2,4-diisocyanate, toluene-2,6-diisocyanate or diphenylmethane diisocyanate.

Illustratively, the isocyanate may be selected from MDI-50, MDI-100, TDI-65, TDI-80, TDI-100, and the like. TDI-65 to TDI-100 refer to the mass ratio of toluene-2,4-diisocyanate to toluene-2,6-diisocyanate from 65:35 to 100:0.

Preferably, the leveling agent comprises BYK-9565 and/or BYK-333.

In this application, "molecular weight" refers to the number average molecular weight.

Preferably, the preparation method of the closed polyurethane prepolymer comprises the following steps:

Mix the first part of polyol and isocyanate to carry out the first reaction, then add the second part of polyol, react until the isocyanate group (-NCO) is lower than the theoretical value, stop the reaction, add synergist and blocking agent, and carry out the second reaction , react until there is no isocyanate group in the system to obtain the closed polyurethane prepolymer;

Wherein, the total mass of the first part of the polyol and the second part of the polyol is the added amount of the polyol in the formula.

Preferably, the preparation method further comprises: mixing a chain extender and/or a crosslinking agent with the first part of the polyol.

Preferably, the preparation method further comprises: adding a leveling agent after the adding of the synergist and the blocking agent.

Preferably, the specific process of the first reaction is as follows: incubate the reaction at 30-35°C for 1 hour, then react at 65-75°C (preferably 70°C) for 3 hours, and then heat up to 85-90°C and react for 3 hours .

Preferably, the second reaction is performed at 70-75° C. for 1 hour.

In a second aspect, the present application provides a polyurethane material, which is formed by curing the solvent-free closed-type polyurethane resin composition described in the first aspect.

Preferably, the curing temperature is 60-130°C, such as 60°C, 90°C, 120°C, and the like.

Preferably, the curing time is 1-3 minutes.

In a third aspect, the present application provides a leather product, and the raw materials for preparing the leather product include the polyurethane material described in the second aspect.

Compared with the prior art, the present application has the following beneficial effects:

In the present application, a specific type of amine curing agent and a temperature-sensitive catalyst are used in the solvent-free closed polyurethane system, which can realize the rapid curing of the polyurethane resin at low temperature, and the obtained polyurethane resin has excellent peeling force, peeling force retention and hydrolysis resistance.

The solvent-free blocked polyurethane resin composition provided by this application takes less than 2 minutes and 30 seconds to fully cure at 120°C, the minimum curing temperature can be as low as 60°C, and the time for curing to semi-dry at 90°C does not exceed 1 minute50 Second, the peeling force after complete curing can reach 8-12kg/cm ³ , and the peeling force retention rate can reach 80-95%.

Detailed ways

The technical solutions of the present application are further described below through specific embodiments. It should be understood by those skilled in the art that the embodiments are only for helping the understanding of the present application, and should not be regarded as a specific limitation of the present application.

Details of the raw materials used in the following examples and comparative examples are as follows:

raw material	buy manufacturers
Polyoxypropylene glycol, molecular weight 1000	Dow Chemical (China) Co., Ltd.
Polyoxypropylene glycol, molecular weight 2000	Dow Chemical (China) Co., Ltd.
Polyoxypropylene triol, molecular weight 3000	jia hua chemical co., ltd.
Polyoxypropylene glycol, molecular weight 4000	jia hua chemical co., ltd.
Polyoxypropylene triol, molecular weight 6000	Kelia Polyol (Nanjing) Co., Ltd.
Polyoxypropylene glycol, molecular weight 8000	jia hua chemical co., ltd.
Polytetrahydrofuran ether glycol, molecular weight 2000	BASF (China) Co., Ltd.
Trimethylolpropane (TMP)	Shandong Shunxinlong New Material Technology Co., Ltd.
MDI-50	Wanhua Chemical Group Co., Ltd.
MDI-100	Wanhua Chemical Group Co., Ltd.
TDI-65	Umay Chemical Co., Ltd.
TDI-80	Umay Chemical Co., Ltd.
TDI-100	Bayer (China) Co., Ltd.
KH550	Nanjing Chengong Silicone Materials Co., Ltd.
BYK-9565	BYK chemical company
3,5-Dimethylpyrazole	Wuhan Yuancheng Saichuang Technology Co., Ltd.
polycat SA8	Evonik Specialty Chemicals Ltd.

Example 1

This embodiment provides a solvent-free blocked polyurethane resin composition, which is composed of 100 g of blocked polyurethane prepolymer, 7.1 g of amine curing agent (DMDC) and 0.1 g of a temperature-sensitive catalyst (polycat SA8).

The preparation raw material of above-mentioned closed type polyurethane prepolymer is as follows:

(1) After mixing 600g of polyoxypropylene glycol (PPG-4000) and 1g of trimethylolpropane, add TDI-80 at one time, stir and react at 33°C for 30 minutes, heat up to 85°C and react for 4 hours, then put in 200g of polyoxypropylene glycol (PPG-2000) and 50g of polyoxypropylene glycol (PPG-1000) were incubated at 80°C for 4 hours, the test-NCO value was 2.69%, cooled to 60°C, and 2g KH550 (synergist) was added dropwise. ) and 62g slowly add 3,5-dimethylpyrazole, then add 5g BYK-9565 at one time and continue to keep the temperature for 1 hour, after the -NCO test is zero, the material is discharged to obtain a closed polyurethane prepolymer with a viscosity of 23000cps at 25°C .

(2) Adding formula amounts of amine curing agent and temperature-sensitive catalyst to the blocked polyurethane prepolymer, and dispersing at 300 rpm for 10 minutes to obtain a solvent-free blocked polyurethane resin composition.

Example 2

This embodiment provides a solvent-free sealed polyurethane resin composition, which is composed of 100 g of a sealed polyurethane prepolymer, 5.0 g of an amine curing agent (DMDC) and 0.1 g of a temperature-sensitive catalyst (polycat SA8).

The preparation raw material of above-mentioned closed type polyurethane prepolymer is as follows:

(1) Stir and mix 81.1g TDI-80 and 50g MDI-50 for 15 minutes, add 350g polyoxypropylene diol (PPG-4000) and 350g polyoxypropylene triol (PPG-6000) and react at 65°C for 2 hours , then heat up to 80°C for more than 5 hours, cool down to 60°C and add 50g polytetrahydrofuran ether diol (PTMEG-2000) and slowly heat up to 80°C, keep for 3 hours, test-NCO value below 1.9%, cool down to 60°C , dropwise add KH550 and slowly add 3,5-dimethylpyrazole, then add 5g BYK-9565 at one time and continue to keep warm for 1 hour, after the -NCO test is zero, the material is discharged to obtain a closed polyurethane prepolymer with a viscosity of 25°C is 28000cps.

(2) Adding formula amounts of amine curing agent and temperature-sensitive catalyst to the blocked polyurethane prepolymer, and dispersing at 300 rpm for 10 minutes to obtain a solvent-free blocked polyurethane resin composition.

Example 3

This embodiment provides a solvent-free sealed polyurethane resin composition, which is composed of 100 g of a sealed polyurethane prepolymer, 5.0 g of an amine curing agent (DMDC) and 0.1 g of a temperature-sensitive catalyst (polycat SA8).

The preparation raw material of above-mentioned closed type polyurethane prepolymer is as follows:

(1) 400 g of polyoxypropylene glycol (PPG-4000), 400 g of polyoxypropylene glycol (PPG-8000) and 2 g of trimethylolpropane were stirred and mixed at 65°C for 30 minutes, cooled to 40°C, and 77.5 g TDI-100, stir for 30 minutes and then heat up to 90°C for more than 6 hours, cool down to 50°C and add 100g polyneopentyl adipate diol (PNA, molecular weight 2000), slowly heat up to 90°C and continue to keep warm React for 3 hours, test the -NCO value below 2.0%, cool down to 60°C, add KH550 dropwise and slowly add 3,5-dimethylpyrazole, then add 5g BYK-9565 at one time and continue to hold for 1 hour, the -NCO test is After zero discharge, a closed polyurethane prepolymer is obtained, and the viscosity at 25°C is 22000cps.

(2) Adding formula amounts of amine curing agent and temperature-sensitive catalyst to the blocked polyurethane prepolymer, and dispersing at 300 rpm for 10 minutes to obtain a solvent-free blocked polyurethane resin composition.

Example 4

This embodiment provides a solvent-free sealed polyurethane resin composition, which is composed of 100 g of a sealed polyurethane prepolymer, 6.3 g of an amine curing agent (DMDC) and 0.1 g of a temperature-sensitive catalyst (polycat SA8).

The preparation raw material of above-mentioned closed type polyurethane prepolymer is as follows:

(1) 2.0g trimethylolpropane and 500g polyoxypropylene glycol (PPG-4000) were stirred at 65°C for 20 minutes, cooled to 40°C, and 95.0g TDI-65 was added at one time, and the temperature was raised to 90°C for reaction 5 After one hour, the temperature was lowered to 70°C, and 150g of poly(methyltrimethylene adipate) diol (molecular weight 2000) and 200g of poly(neopentyl adipate) diol (molecular weight 4000) were added, and the temperature was slowly raised to 80°C, and the temperature was continued. React for 6 hours, test the -NCO value below 2.4%, cool down to 60°C, add KH550 dropwise and slowly add 3,5-dimethylpyrazole, then add 7g BYK-9565 at one time and continue to hold for 1 hour, the -NCO test is After zero discharge, a closed polyurethane prepolymer is obtained, and the viscosity at 25°C is 45000cps.

(2) Adding formula amounts of amine curing agent and temperature-sensitive catalyst to the blocked polyurethane prepolymer, and dispersing at 300 rpm for 10 minutes to obtain a solvent-free blocked polyurethane resin composition.

Example 5

This embodiment provides a solvent-free blocked polyurethane resin composition, which is composed of 100 g of blocked polyurethane prepolymer, 8.9 g of amine curing agent (DMDC) and 0.1 g of a temperature-sensitive catalyst (polycat SA8).

The preparation raw material of above-mentioned closed type polyurethane prepolymer is as follows:

(1) 2.0 g of trimethylolpropane, 100 g of polyoxypropylene glycol (PPG-4000), 300 g of polyoxypropylene glycol (PPG-2000) and 1.5 g of trimethylolpropane were stirred at 65° C. for 20 minutes , cooled to 40 degrees and added 119g TDI-80 at one time, heated to 80°C for 4 hours, cooled to 70°C and added 300g polyneopentyl adipate diol (molecular weight 2000), slowly heated to 80°C, Continue the incubation reaction for 6 hours, test the -NCO value below 3.5%, cool down to 60 ° C, add KH550 dropwise and slowly add 3,5-dimethylpyrazole, then add 7g BYK-9565 at one time and continue to incubate for 1 hour, -NCO After the test is zero, the material is discharged to obtain a closed polyurethane prepolymer with a viscosity of 38000cps at 25°C.

(2) Adding formula amounts of amine curing agent and temperature-sensitive catalyst to the blocked polyurethane prepolymer, and dispersing at 300 rpm for 10 minutes to obtain a solvent-free blocked polyurethane resin composition.

Example 6

This example provides a solvent-free blocked polyurethane resin composition, which is composed of 100 g of blocked polyurethane prepolymer, 6.5 g of amine curing agent (DMDC) and 0.1 g of a temperature-sensitive catalyst (polycat SA8).

The preparation raw material of above-mentioned closed type polyurethane prepolymer is as follows:

(1) 200.0 g of polyoxypropylene diol (PPG-2000) and 400 g of polyoxypropylene triol (PPG-6000) were stirred at 40°C for 20 minutes, and 84.5 g of MDI-50 and 19.6 g of TDI-80 were added at one time. , heat up to 70 ℃ and react for 2.5 hours, cool down to 60 ℃, add 50g polyneopentyl adipate diol (molecular weight 2000), slowly heat up to 75 ℃, continue to hold the reaction for 4 hours, test-NCO value 2.5% Below, the temperature was lowered to 60°C, KH550 was added dropwise and 3,5-dimethylpyrazole was slowly added, and then 6g of BYK-9565 was added at one time to keep the temperature for 1 hour. After the -NCO test was zero, the material was discharged to obtain a closed polyurethane Polymer, the viscosity at 25°C is 29000cps.

(2) Adding formula amounts of amine curing agent and temperature-sensitive catalyst to the blocked polyurethane prepolymer, and dispersing at 300 rpm for 10 minutes to obtain a solvent-free blocked polyurethane resin composition.

Example 7

This embodiment provides a solvent-free blocked polyurethane resin composition, which is composed of 100 g of blocked polyurethane prepolymer, 8.3 g of amine curing agent (DMDC) and 0.1 g of a temperature-sensitive catalyst (polycat SA8).

The preparation raw material of above-mentioned closed type polyurethane prepolymer is as follows:

(1) 400.0 g of polyoxypropylene triol (PPG-3000), 200 g of polyoxypropylene diol (PPG-2000) and 150 g of polyoxypropylene diol (PPG-4000) were stirred at 40°C for 20 minutes, and added at one time. 88.2g TDI-80 and 42.2g MDI-100 were heated to 70°C for 6 hours, the test-NCO value was below 3.2%, cooled to 60°C, KH550 was added dropwise and 3,5-dimethylpyrazole was slowly added, followed by Add 6g of BYK-9565 at one time and continue to keep the temperature for 1 hour. After the -NCO test is zero, the material is discharged to obtain a closed polyurethane prepolymer with a viscosity of 42000cps at 25°C.

(2) Adding formula amounts of amine curing agent and temperature-sensitive catalyst to the blocked polyurethane prepolymer, and dispersing at 300 rpm for 10 minutes to obtain a solvent-free blocked polyurethane resin composition.

Example 8

This embodiment provides a solvent-free blocked polyurethane resin composition, which is composed of 100 g of blocked polyurethane prepolymer, 6.2 g of amine curing agent (DMDC) and 0.1 g of a temperature-sensitive catalyst (polycat SA8).

The preparation raw material of above-mentioned closed type polyurethane prepolymer is as follows:

(1) 2.0g TMP, 700.0g polyoxypropylene glycol (PPG-4000) and 50g polyoxypropylene glycol (PPG-1000) were stirred at 40°C for 20 minutes, 123.8g MDI-50 was added at one time, and the temperature was increased. React at 70°C for 6 hours, test-NCO value below 2.4%, cool down to 60°C, dropwise add KH550 and slowly add 3,5-dimethylpyrazole, then add 5g BYK-9565 at one time and continue to hold for 1 hour,- After the NCO test is zero, the material is discharged to obtain a closed polyurethane prepolymer with a viscosity of 22000cps at 25°C.

(2) Adding formula amounts of amine curing agent and temperature-sensitive catalyst to the blocked polyurethane prepolymer, and dispersing at 300 rpm for 10 minutes to obtain a solvent-free blocked polyurethane resin composition.

Example 9

This embodiment provides a solvent-free sealed polyurethane resin composition, which is composed of 100 g of sealed polyurethane prepolymer (Bayer HS-80) and 10 g of amine curing agent (DMDC);

The preparation method is as follows:

10 g of an amine curing agent was added to the Bayer HS-80, and dispersed at 300 rpm for 10 minutes to obtain a solvent-free sealed polyurethane resin composition.

Example 10

The only difference from Example 1 is that DMDC is replaced with an equimolar amount of PACM, and the solvent-free blocked polyurethane resin composition is composed of 100 g of blocked polyurethane prepolymer, 6.3 g of amine curing agent (PACM) and 0.1 g of temperature sensitive Catalyst (polycat SA8) composition.

Example 11

The only difference from Example 1 is that the DMDC is replaced with an equimolar amount of IPDA, and the solvent-free blocked polyurethane resin composition is composed of 100 g of blocked polyurethane prepolymer, 5.1 g of amine curing agent (IPDA) and 0.1 g of temperature sensitive. Catalyst (polycat SA8) composition.

Example 12

The only difference from Example 1 is that KH550 is replaced by an equimolar amount of KH570.

Example 13

The only difference from Example 1 is that 3,5-dimethylpyrazole is replaced by an equimolar amount of methyl ethyl ketoxime.

Example 14

The only difference from Example 1 is that the amount of DMDC added is 4 g.

Example 15

The only difference from Example 1 is that the amount of DMDC added is 13 g.

Example 16

The difference from Example 1 is that the amount of polycat SA8 added is 10 g.

Comparative Example 1

The difference from Example 1 is that DMDC is replaced by an equimolar amount of methylcyclohexanediamine (HTDA).

Comparative Example 2

The only difference from Example 1 is that polycat SA8 is replaced by an equimolar amount of dibutyltin dilaurate (T12).

Comparative Example 3

The only difference from Example 1 is that the amount of DMDC added is 3 g.

Comparative Example 4

The only difference from Example 1 is that the amount of DMDC added is 15 g.

Comparative Example 5

The only difference from Example 1 is that the amount of polycat SA8 added is 0.05g.

Comparative Example 6

The only difference from Example 1 is that the amount of polycat SA8 added is 11 g.

performance test 1

The time required for complete curing of the solvent-free blocked polyurethane resin compositions provided by the above examples and comparative examples is tested at a certain curing temperature, and the test results are shown in the following table:

	curing temperature	curing time
Example 1	120℃	2 minutes
Example 2	120℃	2 minutes
Example 3	120℃	2 minutes
Example 4	120℃	2 minutes
Example 5	120℃	2 minutes
Example 6	120℃	2 minutes
Example 7	120℃	2 minutes
Example 8	120℃	2 minutes
Example 9	160℃	4 minutes
Example 10	120℃	2 minutes
Example 11	120℃	2 minutes 30 seconds

Example 12	120℃	2 minutes
Example 13	160℃	4 minutes
Example 14	120℃	1 minute 40 seconds
Example 15	120℃	2 minutes 30 seconds
Example 16	120℃	40 seconds
Comparative Example 1	120℃	5 minutes
Comparative Example 2	120℃	5 minutes 10 seconds
Comparative Example 3	120℃	2 minutes 50 seconds
Comparative Example 4	120℃	3 minutes 30 seconds
Comparative Example 5	120℃	3 minutes 50 seconds
Comparative Example 6	120℃	30 seconds

It can be seen from the above table that the present application can effectively improve the curing rate of the solvent-free blocked polyurethane resin composition by adding a specific amine curing agent and a temperature-sensitive catalyst.

Comparative example 1 uses other kinds of room temperature curing agent, and comparative example 2 uses non-temperature-sensitive catalyst, and its curing rate is significantly lower than that of Example 1; the addition amount of curing agent in Comparative Examples 3 and 4 is not within the scope of this application , the curing rate is also reduced; in Comparative Example 5, the addition amount of temperature-sensitive catalyst is less, and the curing rate is significantly reduced. ingredients, which will result in a decrease in the peel force of the product.

Example 9 Using the prepolymer of Bayer HS-80, compared with the prepolymer prepared with 3,5-dimethylpyrazole as the blocking agent and KH550 as the synergist, the curing rate of the polyurethane resin composition was significantly reduced , with higher cure times at higher temperatures.

By comparing Example 1 and Example 13, it can be seen that the curing rate can be further improved by selecting 3,5-dimethylpyrazole as the blocking agent (Example 1).

performance test 2

The following tests are carried out for the solvent-free blocked polyurethane resin compositions provided by the above examples and comparative examples:

(1) Scrape on the fabric film with a 300-micron coating rod, bake and solidify at a certain temperature to semi-dry, and record the semi-dry time;

The preparation method of the above-mentioned fabric film is: 100 parts of Huafeng JF-PDY-821H resin, 1 part of dynol 604 wetting and leveling agent (purchased from Evonik Specialty Chemicals (Shanghai) Co., Ltd.), dark blue water-based black pulp BLPE 517 (purchased from Evonik). 2 parts from Zhejiang Shenlan New Material Technology Co., Ltd. and 0.8 part of TEGO ViscoPlus 3030 thickener (purchased from Evonik Specialty Chemicals (Shanghai) Co., Ltd.), dispersed for 30 minutes, filtered and deaerated for 30 minutes, and scraped for 10 seconds Bake at 90°C/110°C/130°C for 3 minutes each, then scrape for 15 seconds for the second time, and bake at 90°C/110°C/130°C for 3 minutes each to obtain a fabric film;

(2) Immediately apply the cloth after semi-drying, and then use a 10kg pressure roller for heavy pressure bonding, continue to bake until fully cured, and test the peeling force of the cured film according to the QB/T2888-2007 standard, then at 70 ° C/95% The peeling force was tested again after being placed under humidity for 5 weeks, and the peeling force retention rate was calculated according to (peeling force after 5 weeks/initial peeling force)×100%.

(3) The following peel force test was carried out for the resin compositions (Examples 9 and 13) that could not be semi-dry at 90°C: 100 parts of Huafeng JF-PDY-511H resin, BYK425 thickener (purchased from BYK, Germany) Company) 2 parts to increase the viscosity to about 15000cp, scrape the uncurable resin composition on the dried JF-PDY-821H fabric, bake at 160 ℃ for 4 minutes, and then scrape 511H for 15 seconds, 5kg pressure roller to fit The microfiber 1.0mm bass was baked at 90°C/110°C/130°C for 3 minutes each, and the peel force and peel force retention rate were tested according to the method (2).

The above test results are shown in the following table:

The semi-dry described in this application means that the solvent-free blocked polyurethane resin composition has a certain viscosity, but is not completely cured.

It can be seen from the above table that the solvent-free sealed polyurethane resin composition provided by the present application can be rapidly cured at a lower temperature, and after complete curing, it has a relatively high peel force and a peel force retention rate under high temperature and high humidity conditions.

Compared with Example 1, Comparative Example 1 uses other kinds of normal temperature curing agents, and Comparative Example 2 uses a non-temperature-sensitive catalyst, and the low-temperature curing rate is not as good as that of Example 1, and the peel force and peel force retention rate are also worse; In Example 3, the amount of curing agent added is less, the curing rate is reduced, and the peel force of the product is significantly reduced. In Comparative Example 4, the amount of curing agent added is too large, and the peel force retention rate of the product is significantly reduced; If the amount is less, the low-temperature curing rate is obviously reduced, and the addition amount of the temperature-sensitive catalyst in Comparative Example 6 is too large, and the peeling force and the peeling force retention rate are obviously deteriorated.

By comparing Examples 1, 10 and 11, it can be seen that DMDC is selected as the curing agent (Example 1), which is more conducive to improving peel force and peel force retention than PACM (Example 10) and IPDA (Example 11). .

By comparing Examples 1 and 12, it can be seen that using KH550 as a synergist (Example 1) is more conducive to improving the peel force retention rate than other types of synergists (Example 12).

By comparing Example 1 and Example 13, it can be seen that the use of dimethylpyrazole as the blocking agent (Example 1) can further promote low-temperature curing performance compared with other types of blocking agents (Example 13).

Example 9 Using the prepolymer of Bayer HS-80, compared with the prepolymer prepared with 3,5-dimethylpyrazole as the blocking agent and KH550 as the synergist, it could not be cured at 90°C, It is proved that the selection of specific blocking agent and synergist in this application is beneficial to improve the low temperature curing performance of polyurethane.

The present application illustrates the detailed method of the present application through the above-mentioned embodiments, but the present application is not limited to the above-mentioned detailed method, that is, it does not mean that the present application must rely on the above-mentioned detailed method for implementation. Those skilled in the art should understand that any improvement to the application, the equivalent replacement of each raw material of the product of the application, the addition of auxiliary components, the selection of specific methods, etc., all fall within the scope of protection and disclosure of the application.

Claims (12)

1. A solvent-free closed type polyurethane resin composition, which comprises the following components according to parts by weight:

   100 copies of closed polyurethane prepolymer;

   4-13 parts of amine curing agent; and

   0.1-10 copies of temperature-sensitive catalyst;

   Wherein, the amine curing agent includes any one of 3,3-dimethyl-4,4-diaminodicyclohexylmethane, 4,4-diaminodicyclohexylmethane or isophorone diamine or at least two combinations.
2. The solvent-free blocked polyurethane resin composition according to claim 1, wherein the amine curing agent comprises 3,3-dimethyl-4,4-diaminodicyclohexylmethane.
3. The solvent-free blocked polyurethane resin composition according to claim 1 or 2, wherein the temperature-sensitive catalyst comprises an organic bismuth catalyst and/or an organic amine catalyst.
4. The solvent-free blocked polyurethane resin composition according to any one of claims 1-3, wherein the raw materials for preparing the blocked polyurethane prepolymer include a combination of polyol and isocyanate.
5. The solvent-free blocked polyurethane resin composition according to any one of claims 1-4, wherein the preparation raw materials of the blocked polyurethane prepolymer further include a synergist and/or a blocking agent;

   Preferably, the synergist comprises γ-aminopropyltriethoxysilane;

   Preferably, the blocking agent includes pyrazole compounds, preferably 3,5-dimethylpyrazole and/or pyrazole, more preferably 3,5-dimethylpyrazole;

   Preferably, the raw materials for preparing the closed polyurethane prepolymer further include any one or a combination of at least two of a chain extender, a crosslinking agent or a leveling agent.
6. The solvent-free closed-type polyurethane resin composition according to any one of claims 1-5, wherein the preparation raw materials of the closed-type polyurethane prepolymer include the following components according to mass percentage:

   
7. The solvent-free closed-type polyurethane resin composition according to any one of claims 1-6, wherein the preparation raw materials of the closed-type polyurethane prepolymer include the following components according to mass percentage:

   
8. The solvent-free blocked polyurethane resin composition according to any one of claims 4-7, wherein the polyol comprises polyester polyol and/or polyether polyol;

   Preferably, the molecular weight of the polyol is 250-10000;

   Preferably, the polyester polyol comprises polyneopentyl adipate diol, poly-1,4-butanediol adipate diol, poly-1,6-hexanediol adipate Ester diol, polyethylene adipate diol, polymethyltrimethylene adipate diol, polydiethylene adipate diol, or polybutylene methyltrimethylene adipate diol any one or a combination of at least two;

   Preferably, the polyether polyol includes polyoxypropylene glycol, trifunctional polyoxypropylene glycol with methyl propylene glycol or glycerol as the initiator, polyoxyethylene glycol or polytetramethylene ether diol Any one or a combination of at least two of the alcohols.
9. The solvent-free blocked polyurethane resin composition according to any one of claims 4-8, wherein the chain extender comprises ethylene glycol, 1,4-butanediol (BDO), neopentyl glycol or Any one or at least two combinations of 1,6-hexanediol;

   Preferably, the cross-linking agent comprises trimethylolpropane and/or glycerol;

   Preferably, the isocyanate includes any one or a combination of at least two of toluene-2,4-diisocyanate, toluene-2,6-diisocyanate or diphenylmethane diisocyanate.
10. The solvent-free closed-type polyurethane resin composition according to any one of claims 6-8, wherein the preparation method of the closed-type polyurethane prepolymer comprises the following steps:

    Mix the first part of polyol and isocyanate, carry out the first reaction, then add the second part of polyol, react until the isocyanate group is lower than the theoretical value, stop the reaction, add synergist and blocking agent, carry out the second reaction, and react to the system There is no isocyanate group in it to obtain the closed polyurethane prepolymer;

    Wherein, the total mass of the first part of the polyol and the second part of the polyol is the added amount of the polyol in the formula;

    Preferably, the preparation method further comprises: mixing a chain extender and/or a cross-linking agent with the first part of the polyol;

    Preferably, the preparation method further comprises: adding a leveling agent after the adding of the synergist and the blocking agent;

    Preferably, the specific process of the first reaction is as follows: firstly, the temperature is kept at 30-35°C for 1 hour, then the reaction is performed at 65-75°C for 3 hours, and then the temperature is raised to 85-90°C for 3 hours;

    Preferably, the second reaction is performed at 70-75° C. for 1 hour.
11. A polyurethane material, which is formed by curing the solvent-free closed-type polyurethane resin composition according to any one of claims 1-10;

    Preferably, the curing temperature is 60-130°C;

    Preferably, the curing time is 1-3 minutes.
12. A leather product, the preparation raw material of which comprises the polyurethane material of claim 11 .