CN115710344A - Polyisocyanate curing agent with storage stability, preparation method and application - Google Patents
Polyisocyanate curing agent with storage stability, preparation method and application Download PDFInfo
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- CN115710344A CN115710344A CN202211322648.1A CN202211322648A CN115710344A CN 115710344 A CN115710344 A CN 115710344A CN 202211322648 A CN202211322648 A CN 202211322648A CN 115710344 A CN115710344 A CN 115710344A
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- toluene diisocyanate
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- polyisocyanate
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- 239000003795 chemical substances by application Substances 0.000 title claims abstract description 73
- 239000005056 polyisocyanate Substances 0.000 title claims abstract description 53
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- 238000002360 preparation method Methods 0.000 title claims description 9
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- 238000006243 chemical reaction Methods 0.000 claims abstract description 32
- LOCPTSFJZDIICR-UHFFFAOYSA-N 1,3-bis(3-isocyanato-4-methylphenyl)-1,3-diazetidine-2,4-dione Chemical compound C1=C(N=C=O)C(C)=CC=C1N1C(=O)N(C=2C=C(C(C)=CC=2)N=C=O)C1=O LOCPTSFJZDIICR-UHFFFAOYSA-N 0.000 claims abstract description 31
- 238000000034 method Methods 0.000 claims abstract description 28
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- 239000007787 solid Substances 0.000 claims description 26
- 238000000926 separation method Methods 0.000 claims description 18
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- 239000000539 dimer Substances 0.000 claims description 5
- PUPZLCDOIYMWBV-UHFFFAOYSA-N (+/-)-1,3-Butanediol Chemical compound CC(O)CCO PUPZLCDOIYMWBV-UHFFFAOYSA-N 0.000 claims description 4
- RGSFGYAAUTVSQA-UHFFFAOYSA-N Cyclopentane Chemical compound C1CCCC1 RGSFGYAAUTVSQA-UHFFFAOYSA-N 0.000 claims description 4
- IMNFDUFMRHMDMM-UHFFFAOYSA-N N-Heptane Chemical compound CCCCCCC IMNFDUFMRHMDMM-UHFFFAOYSA-N 0.000 claims description 4
- OFBQJSOFQDEBGM-UHFFFAOYSA-N Pentane Chemical compound CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 claims description 4
- 239000000853 adhesive Substances 0.000 claims description 4
- 230000001070 adhesive effect Effects 0.000 claims description 4
- WERYXYBDKMZEQL-UHFFFAOYSA-N butane-1,4-diol Chemical compound OCCCCO WERYXYBDKMZEQL-UHFFFAOYSA-N 0.000 claims description 4
- IQPQWNKOIGAROB-UHFFFAOYSA-N isocyanate group Chemical group [N-]=C=O IQPQWNKOIGAROB-UHFFFAOYSA-N 0.000 claims description 3
- ZWVMLYRJXORSEP-UHFFFAOYSA-N 1,2,6-Hexanetriol Chemical compound OCCCCC(O)CO ZWVMLYRJXORSEP-UHFFFAOYSA-N 0.000 claims description 2
- QWGRWMMWNDWRQN-UHFFFAOYSA-N 2-methylpropane-1,3-diol Chemical compound OCC(C)CO QWGRWMMWNDWRQN-UHFFFAOYSA-N 0.000 claims description 2
- OWBTYPJTUOEWEK-UHFFFAOYSA-N butane-2,3-diol Chemical compound CC(O)C(C)O OWBTYPJTUOEWEK-UHFFFAOYSA-N 0.000 claims description 2
- WJTCGQSWYFHTAC-UHFFFAOYSA-N cyclooctane Chemical compound C1CCCCCCC1 WJTCGQSWYFHTAC-UHFFFAOYSA-N 0.000 claims description 2
- 239000004914 cyclooctane Substances 0.000 claims description 2
- SZXQTJUDPRGNJN-UHFFFAOYSA-N dipropylene glycol Chemical compound OCCCOCCCO SZXQTJUDPRGNJN-UHFFFAOYSA-N 0.000 claims description 2
- 238000000605 extraction Methods 0.000 claims description 2
- TVMXDCGIABBOFY-UHFFFAOYSA-N octane Chemical compound CCCCCCCC TVMXDCGIABBOFY-UHFFFAOYSA-N 0.000 claims description 2
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- 230000035484 reaction time Effects 0.000 claims description 2
- QXJQHYBHAIHNGG-UHFFFAOYSA-N trimethylolethane Chemical compound OCC(C)(CO)CO QXJQHYBHAIHNGG-UHFFFAOYSA-N 0.000 claims description 2
- 239000004848 polyfunctional curative Substances 0.000 claims 2
- 238000004064 recycling Methods 0.000 claims 2
- -1 hydroxyl compound Chemical class 0.000 claims 1
- 239000000178 monomer Substances 0.000 abstract description 40
- KXDHJXZQYSOELW-UHFFFAOYSA-M Carbamate Chemical compound NC([O-])=O KXDHJXZQYSOELW-UHFFFAOYSA-M 0.000 abstract description 9
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 description 30
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- 238000005227 gel permeation chromatography Methods 0.000 description 5
- DKPFZGUDAPQIHT-UHFFFAOYSA-N butyl acetate Chemical compound CCCCOC(C)=O DKPFZGUDAPQIHT-UHFFFAOYSA-N 0.000 description 4
- ZWEHNKRNPOVVGH-UHFFFAOYSA-N 2-Butanone Chemical compound CCC(C)=O ZWEHNKRNPOVVGH-UHFFFAOYSA-N 0.000 description 3
- 238000007792 addition Methods 0.000 description 3
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- 238000000638 solvent extraction Methods 0.000 description 3
- 150000005846 sugar alcohols Polymers 0.000 description 3
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- 241000272814 Anser sp. Species 0.000 description 2
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- 238000000576 coating method Methods 0.000 description 2
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- FUZZWVXGSFPDMH-UHFFFAOYSA-N hexanoic acid Chemical compound CCCCCC(O)=O FUZZWVXGSFPDMH-UHFFFAOYSA-N 0.000 description 2
- AOGQPLXWSUTHQB-UHFFFAOYSA-N hexyl acetate Chemical compound CCCCCCOC(C)=O AOGQPLXWSUTHQB-UHFFFAOYSA-N 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
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- YKYONYBAUNKHLG-UHFFFAOYSA-N propyl acetate Chemical compound CCCOC(C)=O YKYONYBAUNKHLG-UHFFFAOYSA-N 0.000 description 2
- RUELTTOHQODFPA-UHFFFAOYSA-N toluene 2,6-diisocyanate Chemical compound CC1=C(N=C=O)C=CC=C1N=C=O RUELTTOHQODFPA-UHFFFAOYSA-N 0.000 description 2
- 239000008096 xylene Substances 0.000 description 2
- RYHBNJHYFVUHQT-UHFFFAOYSA-N 1,4-Dioxane Chemical compound C1COCCO1 RYHBNJHYFVUHQT-UHFFFAOYSA-N 0.000 description 1
- CCTFMNIEFHGTDU-UHFFFAOYSA-N 3-methoxypropyl acetate Chemical compound COCCCOC(C)=O CCTFMNIEFHGTDU-UHFFFAOYSA-N 0.000 description 1
- BPPFLEYSLOKFAC-UHFFFAOYSA-N CC(CCCCCC)=O.C(C)(=O)O Chemical compound CC(CCCCCC)=O.C(C)(=O)O BPPFLEYSLOKFAC-UHFFFAOYSA-N 0.000 description 1
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 1
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Landscapes
- Polyurethanes Or Polyureas (AREA)
Abstract
The invention relates to a polyisocyanate curing agent which is prepared by the reaction of toluene diisocyanate and polyhydroxy compound and contains carbamate and can be stored stably at low temperature, wherein the content of toluene diisocyanate dimer in the polyisocyanate curing agent is controlled to be 0.01-4.0wt%. The polyisocyanate curing agent prepared by the method has the characteristics of low free monomer, low color value, good storage stability and excellent application performance.
Description
Technical Field
The invention relates to a polyisocyanate curing agent, in particular to a polyisocyanate curing agent with storage stability, a preparation method and application thereof.
Background
The TDI curing agent is an important member in the polyurethane coating industry, has become the mainstream of the coating market due to the excellent characteristics of good gloss, good elasticity, good toughness and the like of a paint film, is widely applied to wood lacquer and adhesives, and can be divided into the following general curing agents according to types: an adduct of TDI and TMP, an adduct of TDI and a hydroxyl group-containing substance, and a TDI trimer. The TMP-TDI addition product is an important member in the polyurethane coating industry, has become the mainstream of the coating market due to the excellent characteristics of good gloss, good elasticity, good toughness and the like of a paint film, and is competitively developed at home and abroad.
The polyurethane curing agent has a certain amount of isocyanate monomer residues in the preparation process, and various patent documents relate to the preparation of polyurethane curing agents with high solid content and low monomer content, and the methods for reducing the unreacted isocyanate monomer in the curing agent comprise a chemical synthesis method, a solvent extraction method and a film evaporation method. The main equipments of the film evaporation method are a film evaporator and a high vacuum system, under high temperature and negative pressure, the prepolymer is rapidly passed through a column plate in a film state, and the free isocyanate monomer is distilled out.
The Chinese patent CN200510101596 separates the free isocyanate in the curing agent by single-stage film evaporation, and the content of the free TDI in the finally obtained product is lower than 0.5wt%. At present, the application of the thin film evaporation technology in the separation of free isocyanate is mature.
The low-free polyisocyanate curing agent can be obtained by using a film evaporation method, but because isocyanate has heat sensitivity, toluene diisocyanate dimer is generated in the reaction and separation processes, and the toluene diisocyanate dimer can finally enter products, and floc or solid precipitate is produced if the product is stored at zero centigrade, so that the transparency and the service performance of the products are influenced, and the product quality is reduced.
Chinese published patent CN 112341595A proposes a polyisocyanate and a preparation method thereof, wherein the ratio of the integral area of a component peak with the weight average molecular weight of 800 +/-50 to the integral area of a shoulder peak with the weight average molecular weight of 950 +/-50 is controlled to be 2-14, so that the problem that flocs and even solid precipitates sometimes appear in a product solution at a lower storage temperature, but the problem of poor storage stability still appears at a lower storage temperature is solved.
Disclosure of Invention
The invention aims to solve the technical problem of how to improve the storage stability of a polyisocyanate curing agent under the condition of not influencing the use performance of a product.
In order to solve the technical problems, the invention provides a polyisocyanate curing agent with storage stability, and a preparation method and application thereof. The curing agent has the characteristics of stable color value, low free monomer content and excellent storage stability, and has wide applicability.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
in one aspect, the present invention provides a urethane-containing polyisocyanate curing agent prepared by reacting toluene diisocyanate with a polyol, the polyisocyanate curing agent having a toluene diisocyanate dimer content of 0.01 to 4.0% by weight, preferably 0.1 to 3.0% by weight, based on solids.
The solid is the component of the polyisocyanate curing agent except the organic solvent, namely the component of the toluene diisocyanate which is reacted with the polyhydroxy compound and then the unreacted polyisocyanate is removed.
The molar ratio of isocyanate groups in the toluene diisocyanate to hydroxyl groups in the hydroxyl compounds is (2-10): 1, preferably (3-5): 1.
The toluene diisocyanate dimer content of the present invention was determined by gel permeation chromatography using polystyrene as standard and tetrahydrofuran as eluent according to GB/T27810-2011, which is produced by polymerization of two toluene diisocyanates.
The color value of the polyisocyanate curing agent prepared in the invention is less than or equal to 70Hazen, preferably less than or equal to 50Hazen; the free toluene diisocyanate content is not more than 1.0% by weight, preferably not more than 0.5% by weight, based on the total mass of the curing agent.
In the present invention, the solids content is from 30 to 80% by weight, preferably from 60 to 80% by weight, most preferably from 74 to 76% by weight, based on the total mass of the curing agent.
In another aspect, the present invention also provides a method for preparing a polyisocyanate curing agent, the method comprising the steps of:
a. carrying out urethane reaction on toluene diisocyanate and a polyhydroxy compound to prepare prepolymer reaction liquid;
b. evaporating the reaction liquid, removing unreacted toluene diisocyanate, and dissolving the components after removing the unreacted polyisocyanate by using an organic solvent to obtain a urethane-containing polyisocyanate composition;
c. and (c) the unreacted toluene diisocyanate in the step (b) participates in the step (a) for cyclic utilization, and the content of toluene diisocyanate dimer in the unreacted toluene diisocyanate participating in the step (a) is controlled to be less than or equal to 8.0wt%.
The polyhydroxy compound in the step a comprises trihydroxypropane and polyol with the molecular weight of 60-200; wherein the molar ratio of isocyanate groups in the toluene diisocyanate to hydroxyl groups in the hydroxyl compounds is (2-10): 1, preferably (3-5): 1.
The polyhydroxy compound in the step a comprises trimethylolpropane and polyhydric alcohol, wherein the molar ratio of the trimethylolpropane to the hydroxyl of the polyhydric alcohol is (1-10): 1, preferably (2-5): 1.
The polyhydric alcohol in the step a is one or more selected from ethylene glycol, propylene glycol, methyl propylene glycol, 1,3-butanediol, 1,4-butanediol, diethylene glycol and dipropylene glycol, 2-methyl-1,3-propanediol, glycerol, 1,2,6-hexanetriol, trimethylolethane and pentaerythritol.
The reaction temperature of the aminoesterification reaction in the step a is 40-110 ℃, and preferably 50-80 ℃; the reaction time is 0.5h to 12h, preferably 1h to 5h, most preferably 1h to 2h.
In the toluene diisocyanate in the step a, the content of 2,4-toluene diisocyanate is 40-100wt%, preferably 60-80wt%, based on the total mass of the toluene diisocyanate.
The evaporation in the step b is preferably thin film evaporation or short-range evaporation, wherein the primary separation temperature of the thin film evaporation is 120-180 ℃, the pressure is 100-1000Pa, the secondary separation temperature is 150-210 ℃, and the vacuum degree is 0-100Pa; the separation temperature of the short-path evaporator is 140-200 ℃, and the pressure is 1-50Pa.
The organic solvent in the step b is one or more of ethyl acetate, N-propyl acetate, isopropyl acetate, N-butyl acetate, propylene glycol methyl ether acetate, amyl acetone acetate, hexyl acetate, methoxypropyl acetate, tetrahydrofuran, dioxane, acetone, N-methylpyrrolidone, methyl ethyl ketone and petroleum solvent, and preferably ethyl acetate; the organic solvent is dissolved to give a urethane-containing polyisocyanate composition having a solids content of from 30 to 80% by weight, preferably from 73 to 77% by weight.
In the step c, dimer in the unreacted toluene diisocyanate recycled is controlled by means of organic solvent extraction, wherein the organic solvent used for extraction is one or more of n-hexane, cyclohexane, n-pentane, cyclopentane, heptane, cycloheptane, octane and cyclooctane, and preferably n-hexane and/or cyclohexane; mixing the mixture with unreacted toluene diisocyanate in a mixing ratio of 1:10-1:1, preferably 1:5-1:2, most preferably 1:4.
use of a polyisocyanate curing agent as hereinbefore described having storage stability for the preparation of a polyurethane paint or a polyurethane adhesive.
In the invention, researchers find that when the content of the dimer in the prepared polyisocyanate curing agent is more than or equal to 3 percent, the storage stability of the product at low temperature can be greatly reduced. The introduction of the dimer is mainly that a certain amount of toluene diisocyanate dimer is generated in the recovered unreacted toluene diisocyanate due to the high temperature effect in the process of preparing a prepolymer reaction liquid and when the unreacted polyisocyanate is removed from the reaction liquid through an evaporator, when the content of the toluene diisocyanate dimer in the recovered unreacted toluene diisocyanate is more than 8wt%, the content of the toluene diisocyanate dimer in the product after the toluene diisocyanate dimer participates in circulation is more than 4wt%, so that the storage stability of the product is influenced.
The organic solvent extraction mode can effectively control toluene diisocyanate dimer in the recycled unreacted polyisocyanate, namely, after the organic solvent is mixed with the recycled unreacted toluene diisocyanate, insoluble toluene diisocyanate dimer is filtered, and the organic solvent is removed by distillation, rectification or thin film evaporation.
The invention improves the low-temperature storage stability of the product by controlling the content of the toluene diisocyanate dimer of the polyisocyanate curing agent, and has excellent application performance.
Detailed Description
The present invention is further illustrated by the following specific examples, which are intended to be illustrative of the invention and are not to be construed as limiting the scope of the invention.
The NCO content is measured according to the method of GB/T12009.4-1989;
the method is based on the GB/T18583-2008 method, and the content of residual monomers in a reaction system is determined by gas chromatography;
the invention is based on the method of GB/T1725-1979, and the solid content is measured under the test conditions described for isocyanate;
hazen colour values were determined using a colour measurement device (BYK LCS IV).
The number average molecular weight Mn of the components of the polyisocyanate composition of the invention can be determined by GPC (molecular gel chromatography) measurement. The specific test conditions were as follows:
GPC apparatus: agilent1260
GPC column: pl1113-6520 and Pl113-6325 (Agilent)
Sample concentration: 3 wt.%
Mobile phase: tetrahydrofuran (THF)
The detection method comprises the following steps: differential detector
Flow rate: 1ml/min
Column temperature: 35 deg.C
The standard curve used polystyrene with a molecular weight of 162-17900.
Raw materials and reagents:
t80: toluene diisocyanate containing about 80% 2,4-toluene diisocyanate and 20% 2,6-toluene diisocyanate available from Vanhua chemical group, inc.;
t65: toluene diisocyanate, containing about 65% 2,4-toluene diisocyanate and 35% 2,6-toluene diisocyanate, available from Vanhua chemical group, inc.;
trimethylolpropane: purchased by Weifang PassiTo Limited;
diethylene glycol: purchased from Yanshan petrochemical Co., ltd;
ethylene glycol: purchased from national pharmaceutical group chemical reagents, ltd;
glycerol: purchased from national pharmaceutical group chemical agents, ltd.
Example 1
Adding 10kg of T80 into a reaction kettle, heating and stirring at 40 ℃, then dropwise adding mixed alcohol consisting of 1204g of diethylene glycol and 1319g of trimethylolpropane into the reaction kettle, and after dropwise adding, continuously stirring and reacting at 40 ℃ for 10 hours to obtain a prepolymer reaction solution; separating the reaction liquid by using a short-path evaporator (the separation temperature is 150 ℃, and the pressure is 12 Pa), diluting the separated carbamate-containing component by using ethyl acetate to obtain a polyisocyanate curing agent A1; mixing the separated unreacted TDI monomer with cyclohexane according to a mass ratio of 1:4, filtering, and removing the cyclohexane through reduced pressure distillation to obtain the TDI monomer;
the recovered TDI monomer and fresh TDI-80 are mixed to 10kg, the process is repeated, and the polyisocyanate curing agent B1 is obtained
The resulting curing agent was measured to have the following parameters: :
the solid content is 75.1 percent
Free monomer content 0.28%
Color number 21Hazen
The toluene diisocyanate dimer content in the recovered TDI was 0.5%
The curing agent contained 0.1% of toluene diisocyanate dimer based on the solid content.
Example 2
Adding 10kg of T80 into a reaction kettle, heating and stirring at 60 ℃, then dropwise adding mixed alcohol consisting of 677g of diethylene glycol and 1141g of trimethylolpropane into the reaction kettle, and continuously stirring and reacting at 60 ℃ for 4 hours to obtain prepolymer reaction liquid after dropwise adding; separating the reaction liquid by using a short-path evaporator (the separation temperature is 165 ℃, and the pressure is 10 Pa), diluting the separated carbamate-containing component by using ethyl acetate, and obtaining a polyisocyanate curing agent A2; mixing the separated unreacted TDI monomer with cyclohexane according to a mass ratio of 1:6, filtering, and removing the cyclohexane through reduced pressure distillation to obtain the TDI monomer;
the recovered TDI monomer and fresh TDI-80 are mixed to 10kg, the process is repeated, and the polyisocyanate curing agent B2 is obtained
The resulting curing agent was measured to have the following parameters:
the solid content is 74.6 percent
Free monomer content 0.18%
Color number 25Hazen
The toluene diisocyanate dimer content in the recovered TDI was 5.2%
The curing agent contained 2.6% toluene diisocyanate dimer based on solids.
Example 3
Adding 10kg of T80 into a reaction kettle, heating and stirring at 70 ℃, then dropwise adding mixed alcohol consisting of 536g of diethylene glycol and 1128g of trimethylolpropane into the reaction kettle, and after dropwise adding, continuously stirring and reacting at 70 ℃ for 6 hours to obtain a prepolymer reaction solution; separating the reaction liquid by using a short-path evaporator (the separation temperature is 170 ℃, and the pressure is 15 Pa), diluting the separated carbamate-containing component by using ethyl acetate, and obtaining a polyisocyanate curing agent A3; mixing the separated unreacted TDI monomer with cyclohexane according to a mass ratio of 1:2, filtering, and removing the cyclohexane through reduced pressure distillation to obtain the TDI monomer;
the recovered TDI monomer and fresh TDI-80 are mixed to 10kg, the process is repeated, and the polyisocyanate curing agent B3 is obtained
The resulting curing agent was measured to have the following parameters:
the solid content is 75.9 percent
Free monomer content 0.38%
Color number 33Hazen
Toluene diisocyanate dimer content of the recovered TDI of 6.1%
The curing agent contained 3.1% toluene diisocyanate dimer based on solids.
Example 4
Adding 10kg of T65 into a reaction kettle, heating and stirring at 80 ℃, then dropwise adding mixed alcohol consisting of 362g of diethylene glycol and 947g of trimethylolpropane into the reaction kettle, and after dropwise adding, continuously stirring and reacting at 80 ℃ for 7 hours to obtain a prepolymer reaction solution; separating the reaction liquid by adopting a short-path evaporator (the separation temperature is 150 ℃, and the pressure is 12 Pa), and diluting the separated carbamate-containing component by using ethyl acetate to obtain a polyisocyanate curing agent A4; mixing the separated unreacted TDI monomer with n-hexane according to the mass ratio of 1:8, filtering, and removing the n-hexane through reduced pressure distillation to obtain the TDI monomer;
the recovered TDI monomer and fresh TDI-65 are mixed to 10kg, the process is repeated, and the polyisocyanate curing agent B4 is obtained
The resulting curing agent was measured to have the following parameters:
the solid content is 75.2 percent
Free monomer content 0.40%
Color number 50Hazen
The toluene diisocyanate dimer content of the recovered TDI was 2.3%
The curing agent contained 0.9% of toluene diisocyanate dimer in solid content.
Example 5
Adding 10kg of T80 into a reaction kettle, heating and stirring at 50 ℃, then dropwise adding mixed alcohol consisting of 134g of ethylene glycol and 833g of trimethylolpropane into the reaction kettle, and after dropwise adding, continuously stirring and reacting at 50 ℃ for 5 hours to obtain a prepolymer reaction solution; separating the reaction liquid by using a short-path evaporator (the separation temperature is 140 ℃, and the pressure is 5 Pa), and diluting the separated carbamate-containing component by using ethyl acetate to obtain a polyisocyanate curing agent A5; mixing the separated unreacted TDI monomer with cyclohexane according to a mass ratio of 1:3, filtering, removing the cyclohexane through reduced pressure distillation to obtain a TDI monomer, extracting the obtained TDI again, and obtaining a recovered TDI monomer through reduced pressure distillation;
the recovered TDI monomer and fresh TDI-80 are mixed to 10kg, the process is repeated, and the polyisocyanate curing agent B5 is obtained
The resulting curing agent was measured to have the following parameters:
the solid content is 75.5 percent
Free monomer content 0.25%
Color number 15Hazen
The toluene diisocyanate dimer content in the recovered TDI was 0.05%
The curing agent contained 0.01% of toluene diisocyanate dimer in the solid content.
Example 6
Adding 10kg of T80 into a reaction kettle, heating and stirring at 100 ℃, then dropwise adding mixed alcohol consisting of 119g of diethylene glycol and 503g of trimethylolpropane into the reaction kettle, and after dropwise adding, continuously stirring and reacting at 100 ℃ for 1 hour to obtain a prepolymer reaction solution; separating the reaction liquid by using a short-path evaporator (the separation temperature is 200 ℃, and the pressure is 10 Pa), and diluting the separated carbamate-containing component by using ethyl acetate to obtain a polyisocyanate curing agent A6; mixing the separated unreacted TDI monomer with cyclohexane according to a mass ratio of 1:4, filtering, and removing the cyclohexane through reduced pressure distillation to obtain a toluene diisocyanate monomer;
the recovered TDI monomer and fresh TDI-80 are mixed to 10kg, the process is repeated, and polyisocyanate curing agent B6 is obtained
The resulting curing agent was measured to have the following parameters:
solid content 75.5%
Free monomer content 0.18%
Color number 42Hazen
The toluene diisocyanate dimer content of the recovered TDI was 8.0%
The curing agent contained 3.9% toluene diisocyanate dimer based on solids.
Comparative example 1
Adding 10kg of T80 into a reaction kettle, heating and stirring at 70 ℃, then dropwise adding mixed alcohol consisting of 536g of diethylene glycol and 1128g of trimethylolpropane into the reaction kettle, and after dropwise adding, continuously stirring and reacting at 70 ℃ for 6 hours to obtain a prepolymer reaction solution; separating the reaction liquid by using a short-path evaporator (the separation temperature is 170 ℃, and the pressure is 15 Pa), diluting the separated carbamate-containing component by using ethyl acetate, and obtaining a polyisocyanate curing agent A3; separating the obtained unreacted TDI monomer
Mixing the TDI monomer obtained by separation with fresh TDI-80 to 10kg, and repeating the process to obtain polyisocyanate curing agent B7
The resulting curing agent was measured to have the following parameters:
the solid content is 75.7 percent
The content of free monomers is 0.36 percent
Color number 30Hazen
The toluene diisocyanate dimer content of the recovered TDI was 10.1%
The curing agent contained 5.6% toluene diisocyanate dimer based on solids.
Comparative example 2
Adding 10kg of T80 into a reaction kettle, heating and stirring at 70 ℃, then dropwise adding mixed alcohol consisting of 536g of diethylene glycol and 1128g of trimethylolpropane into the reaction kettle, and after dropwise adding, continuously stirring and reacting at 70 ℃ for 6 hours to obtain a prepolymer reaction solution; separating the reaction liquid by adopting a short-path evaporator (the separation temperature is 170 ℃, and the pressure is 15 Pa), and diluting the separated carbamate-containing component by using ethyl acetate to obtain a polyisocyanate curing agent A3; separating the obtained unreacted TDI monomer, mixing the separated unreacted TDI monomer with cyclohexane according to the mass ratio of 1:3, filtering, removing the cyclohexane through reduced pressure distillation to obtain the TDI monomer, and repeatedly extracting the obtained TDI until the content of the dimer is 0.01%;
mixing the TDI monomer obtained by separation with fresh TDI-80 to 10kg, and repeating the process to obtain polyisocyanate curing agent B8
The resulting curing agent was measured to have the following parameters:
the solid content is 75.7 percent
Free monomer content 0.33%
Color number 32Hazen
The toluene diisocyanate dimer content in the recovered TDI was 0.01%
The curing agent contained 0.04% of toluene diisocyanate dimer in solid content.
In order to test the storage stability of the polyisocyanate curing agents prepared in each example and comparative example, the obtained polyisocyanate curing agents were each stored at-15 ℃ for 1 month to observe the storage stability, and the results are shown in Table 1.
TABLE 1 testing of storage stability of polyisocyanate curing Agents
From the test results, it can be seen that, compared with comparative example 1, the polyisocyanate curing agent product prepared in the embodiment of the present invention has a clear appearance after being stored for 6 months, has stable product performance, and has significant technical advantages.
The examples and comparative examples are separately compared with Wanhua
TT-350B is mixed according to the mass ratio of 2:1 to prepare a curing agent mixture, the obtained mixture is mixed with commercially common polyol (matt varnish, HS-129) according to the NCO/OH molar ratio of 1:1, mixed solvent of butyl acetate/xylene (equal mass mixture of the two) is added for dilution, wherein the content of the curing agent in a solution formed by the curing agent and the butyl acetate/xylene is 40wt%, and finally the paint is prepared. The prepared paint is subjected to performance tests in the aspects of adhesive force and the like according to the following methods: (1) drying (tack-free) test: GB/T1728; (2) matte glossiness test: GB/T9754; (3) Flow ofAnd (3) testing the flatness: preparing a paint film on the surface of the tinplate, placing the sample plate under the conditions of constant temperature and constant humidity (30 ℃, 35-40% relative humidity), and observing the time required for the painted surface to reach a uniform, smooth and wrinkle-free (no orange peel or goose skin) state; whether the painted surface is in a uniform, smooth, non-wrinkled (orange peel or goose skin free) state is acceptable or not is related to the user's standard regulation for different products; (4) hardness test: GB/T1730; (5) adhesion grade test: GB/T9286. The test results are shown in table 2.
Table 2 paint performance test results
As can be seen from the results of the performance tests of tables 1 and 2, the examples have good storage stability and application properties. Comparative example 1 is poor in storage stability, and comparative example 2 is good in storage stability but poor in drying time, hardness and adhesion, and thus it is known that the curing agent is prepared with a toluene diisocyanate dimer content of 0.01 to 4.0%, and has good storage stability and good in-use properties.
The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and additions can be made without departing from the method of the present invention, and these modifications and additions should also be regarded as the protection scope of the present invention.
Claims (10)
1. A urethane-containing polyisocyanate curing agent prepared by reacting tolylene diisocyanate with a polyol, said polyisocyanate curing agent having a tolylene diisocyanate dimer content of 0.01 to 4.0% by weight, preferably 0.1 to 3.0% by weight, based on solids.
2. The curing agent according to claim 1, wherein the free toluene diisocyanate content is less than or equal to 1.0 wt.%, preferably less than or equal to 0.5 wt.%, based on the total mass of the curing agent; and/or a solids content of 30 to 80 wt.%, preferably 60 to 80 wt.%, most preferably 74 to 76 wt.%, based on the total mass of the curing agent.
3. The method of preparing a urethane-containing polyisocyanate curing agent prepared by reacting toluene diisocyanate with a polyol according to claim 1, comprising the steps of:
a. carrying out urethane reaction on toluene diisocyanate and a polyhydroxy compound to prepare prepolymer reaction liquid;
b. evaporating the reaction liquid, removing unreacted toluene diisocyanate, and dissolving the components after removing the unreacted polyisocyanate by using an organic solvent to obtain a urethane-containing polyisocyanate composition;
c. and c, allowing the unreacted toluene diisocyanate in the step b to participate in the recycling of the step a, and controlling the content of toluene diisocyanate dimer in the unreacted toluene diisocyanate participating in the recycling of the step a to be less than or equal to 8.0%.
4. The method of claim 3, wherein the polyol in step a comprises trihydroxypropane and polyol having a molecular weight of 60-200; and/or the molar ratio of trimethylolpropane to polyol hydroxyl groups is (1-10): 1, preferably (2-5): 1.
5. A process according to claim 3 or 4, wherein the molar ratio of isocyanate groups in the toluene diisocyanate to hydroxyl groups in the hydroxyl compound is (2-10): 1, preferably (3-5): 1.
6. The method of claim 4, wherein the polyol is selected from one or more of ethylene glycol, propylene glycol, methyl propylene glycol, 1,3-butanediol, 1,4-butanediol, diethylene glycol and dipropylene glycol, 2-methyl-1,3-propanediol, glycerol, 1,2,6-hexanetriol, trimethylolethane, and pentaerythritol.
7. The process according to any one of claims 3 to 6, wherein the reaction temperature for the aminoesterification reaction in step a is from 40 to 110 ℃, preferably from 50 to 80 ℃; the reaction time is 0.5h to 12h, preferably 1h to 5h, most preferably 1h to 2h.
8. The method according to any one of claims 3 to 7, wherein the evaporation in step b is preferably thin film evaporation or short path evaporation, wherein the temperature of the first stage separation of thin film evaporation is 120 to 180 ℃ and the pressure is 100 to 1000Pa, the temperature of the second stage separation is 150 ℃ to 210 ℃ and the vacuum degree is 0 to 100Pa; the separation temperature of the short-path evaporator is 140-200 ℃, and the pressure is 1-50Pa.
9. The method according to any one of claims 3 to 8, wherein the dimer in the recycled unreacted toluene diisocyanate is controlled by extraction with an organic solvent selected from the group consisting of n-hexane, cyclohexane, n-pentane, cyclopentane, heptane, cycloheptane, octane, cyclooctane, preferably n-hexane and/or cyclohexane; mixing the mixture with unreacted toluene diisocyanate in a mixing ratio of 1:10-1:1, preferably 1:5-1:2, most preferably 1:4.
10. use of a urethane-containing polyisocyanate hardener prepared by reacting a toluene diisocyanate according to any one of claims 1 to 2 with a polyol or a polyisocyanate hardener prepared by the preparation method according to any one of claims 3 to 9 for preparing a polyurethane paint or a polyurethane adhesive.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109824865A (en) * | 2018-12-26 | 2019-05-31 | 万华化学集团股份有限公司 | Polyisocyanate curing agent preparation method and curing agent with storage stability |
| CN110078889A (en) * | 2019-04-22 | 2019-08-02 | 万华化学集团股份有限公司 | A method of it preparing light color and stores the stable toluene di-isocyanate(TDI) Quito isocyanate composition curing agent of color number |
| CN113087679A (en) * | 2020-01-08 | 2021-07-09 | 万华化学集团股份有限公司 | Polyisocyanate curing agent with low free monomer, preparation method, coating composition and application |
| US20220282026A1 (en) * | 2019-08-09 | 2022-09-08 | Covestro Intellectual Property Gmbh & Co. Kg | Polyisocyanate and process for preparing the same |
-
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- 2022-10-27 CN CN202211322648.1A patent/CN115710344A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109824865A (en) * | 2018-12-26 | 2019-05-31 | 万华化学集团股份有限公司 | Polyisocyanate curing agent preparation method and curing agent with storage stability |
| CN110078889A (en) * | 2019-04-22 | 2019-08-02 | 万华化学集团股份有限公司 | A method of it preparing light color and stores the stable toluene di-isocyanate(TDI) Quito isocyanate composition curing agent of color number |
| US20220282026A1 (en) * | 2019-08-09 | 2022-09-08 | Covestro Intellectual Property Gmbh & Co. Kg | Polyisocyanate and process for preparing the same |
| CN113087679A (en) * | 2020-01-08 | 2021-07-09 | 万华化学集团股份有限公司 | Polyisocyanate curing agent with low free monomer, preparation method, coating composition and application |
Non-Patent Citations (1)
| Title |
|---|
| 杨斯伦;雷波;刘志刚;张巨生;: "低游离甲苯二异氰酸酯(TDI)的聚氨酯固化剂合成研究", 化学工程师, no. 11, 25 November 2012 (2012-11-25) * |
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