CN114230742A - Low-free TDI polyurethane prepolymer and preparation method thereof - Google Patents
Low-free TDI polyurethane prepolymer and preparation method thereof Download PDFInfo
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- CN114230742A CN114230742A CN202111489410.3A CN202111489410A CN114230742A CN 114230742 A CN114230742 A CN 114230742A CN 202111489410 A CN202111489410 A CN 202111489410A CN 114230742 A CN114230742 A CN 114230742A
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- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
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- C08G18/10—Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
- C08G18/40—High-molecular-weight compounds
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- C08G18/4854—Polyethers containing oxyalkylene groups having four carbon atoms in the alkylene group
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- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
- C08G18/72—Polyisocyanates or polyisothiocyanates
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- C08G18/76—Polyisocyanates or polyisothiocyanates cyclic aromatic
- C08G18/7614—Polyisocyanates or polyisothiocyanates cyclic aromatic containing only one aromatic ring
- C08G18/7621—Polyisocyanates or polyisothiocyanates cyclic aromatic containing only one aromatic ring being toluene diisocyanate including isomer mixtures
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Abstract
The invention relates to the field of polyurethane preparation, and particularly provides a low-free TDI polyurethane prepolymer, which comprises the following raw materials in parts by weight: polyether polyol 180-240, isocyanate 70-130, stabilizer 0.005-0.05, antioxidant 0.15-0.5 and azeotropic assistant 5-25. Also provides a preparation method of the polyurethane prepolymer, and the obtained prepolymer is subjected to molecular distillation treatment. According to the invention, the low free toluene diisocyanate prepolymer is prepared by blending the synthetic components of the isocyanate prepolymer and adopting a molecular distillation mode, so that the content of free TDI in the prepolymer is lower and is between 0.07% and 0.25%, and meanwhile, the low free toluene diisocyanate prepolymer has the advantages of low viscosity, good thermal stability, good processing conditions, longer storage time and higher economic value.
Description
Technical Field
The invention relates to the field of polyurethane preparation, and particularly relates to a low-free TDI polyurethane prepolymer and a preparation method thereof.
Background
In the prior art, the polyurethane synthesis method is usually prepared by a prepolymer method, mainly uses polyol and isocyanate as raw materials, and usually uses excessive isocyanate and polyol to synthesize an NCO-terminated prepolymer under certain conditions, namely NCO/OH is more than 1. Most of the common Toluene Diisocyanate (TDI) is Toluene Diisocyanate (TDI), but as the reaction of monomers is insufficient in the reaction process, more free TDI monomers exist, and the free TDI monomers are volatile and have strong toxicity, can harm human health in a breathing inhalation and contact mode, and particularly have great harm to processing personnel in the processing process, the content of the free TDI in the national standard is limited to a certain extent. Furthermore, the residual TDI reacts slowly during storage, which leads to a gradual increase in the viscosity of the prepolymer, a shorter storage period and a limited use time. The low-free prepolymer has longer storage period and is not easy to deteriorate. Therefore, a method for preparing a polyurethane prepolymer with low free TDI is needed.
Disclosure of Invention
The present invention provides a low free TDI polyurethane prepolymer and a preparation method thereof, in order to overcome the problems of the prior art that the residual TDI reacts slowly during storage, which results in gradually increased viscosity of the prepolymer, shortened storage period and limited service time, and thus a preparation method of a low free TDI polyurethane prepolymer is urgently needed. The invention can reduce the content of free TDI in the polyurethane prepolymer.
In order to solve the technical problems, the invention adopts the technical scheme that: a low free TDI polyurethane prepolymer comprises the following raw materials in parts by weight:
preferably, the polyether polyol is at least one of dihydroxy polyether polyol, trihydroxy polyether polyol and tetrahydroxy polyether polyol.
Preferably, the molecular weight of the dihydroxy polyether polyol is selected to be 300-2000.
Preferably, the isocyanate is one of toluene diisocyanate, TDI80/20 and TDI 100.
Preferably, the stabilizer is one selected from citric acid, phosphoric acid, benzoyl chloride and adipic acid.
Preferably, the boiling point of the entrainer is between 200 and 300 ℃.
Preferably, the entrainer is selected from one of dimethyl phthalate, diphenylmethane and glycol dimethyl ether.
Also provides a preparation method of the low free TDI polyurethane prepolymer, which comprises the following steps:
s1, putting the polyether glycol into a reaction kettle, setting the stirring speed at 200-;
s2, when the water content is lower than 0.05% in the step S1, cooling the inside of the reaction kettle to 50 ℃, introducing nitrogen for protection, adding an antioxidant and a stabilizer at the same time, and stirring at constant temperature for 0.5 h;
s3, adding isocyanate, introducing nitrogen for protection, stirring and reacting at a constant temperature of 60 ℃ for 1h, heating to 75 ℃, stirring and reacting at a constant temperature for 2 h;
s4, cooling to 50-60 ℃, adding an azeotropic agent, and stirring at constant temperature for 15-30 min;
s5, adding the prepolymer into a molecular distillation device, setting the preheating feeding temperature at 70-100 ℃, the main heating temperature at 90-150 ℃, the condensing temperature at 30-60 ℃, the vacuum degree at 1-30pa, the film scraping speed at 300-500r/min, controlling the feeding speed at 0.5-1.5L/min, the light component being a mixture of free TDI and auxiliary agent, and the heavy component being a product collected, namely the low free toluene diisocyanate prepolymer.
More preferably, in the step S5, the preheating feeding temperature is 80 ℃, the main heating temperature is 130 ℃, the condensing temperature is 50 ℃, the vacuum degree is 5pa, the film scraping speed is 400r/min, and the feeding speed is controlled to be 0.5L/min.
More preferably, the molecular distillation apparatus has an apparatus evaporation area of 600cm2。
Compared with the prior art, the beneficial effects are:
the low free toluene diisocyanate prepolymer is prepared by blending the synthetic components of the isocyanate prepolymer and adopting a molecular distillation mode, so that the content of free TDI in the prepolymer is lower and is between 0.07 and 0.25 percent, and the low free toluene diisocyanate prepolymer has the advantages of low viscosity, good thermal stability, good processing conditions, longer storage time and higher economic value.
Drawings
FIG. 1 is a schematic flow chart of the production process of the present invention.
Detailed Description
The drawings are for illustrative purposes only and are not to be construed as limiting the patent; for the purpose of better illustrating the embodiments, certain features of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted. The positional relationships depicted in the drawings are for illustrative purposes only and are not to be construed as limiting the present patent.
Example 1
The embodiment provides a low-free TDI prepolymer, which is prepared from the following raw materials in parts by weight: 106 parts of toluene diisocyanate. 220 parts of polyether polyol, 0.005 part of stabilizer, 0.5 part of antioxidant and 5 parts of entrainer, wherein isocyanate is TDI; the polyether polyol is basf's PTMEG650s, the stabilizer is phosphoric acid, the antioxidant is basf's 1010, and the entrainer is diphenylmethane.
As shown in FIG. 1, the preparation method of the prepolymer with low free TDI in the embodiment comprises the following steps:
(1) putting PTMEG polyether polyol into a reaction kettle, setting the stirring speed at 200r/min, the temperature at 110 ℃ and the pressure at 400pa, dehydrating for 3h in vacuum under the condition, and testing the water content to be lower than 0.05%;
(2) cooling the reaction kettle to 50 ℃, introducing nitrogen for protection, simultaneously adding an antioxidant and a stabilizer, and stirring at constant temperature for 0.5 h;
(3) adding toluene diisocyanate, introducing nitrogen for protection, stirring and reacting at the constant temperature of 60 ℃ for 1h, heating to 75 ℃, and stirring and reacting at the constant temperature for 2 h;
(4) cooling to 50 deg.C, adding entrainer, and stirring at constant temperature for 30 min;
(5) adding the prepolymer into a molecular distillation device, setting the preheating feeding temperature to be 80 ℃, the main heating temperature to be 130 ℃, the condensing temperature to be 40 ℃, the vacuum degree to be 5pa, the film scraping speed to be 400r/min, controlling the feeding speed to be 1.0L/min, and collecting a product from heavy components, namely the low-free prepolymer.
The resulting prepolymer was tested for NCO value, free TDI and viscosity and observed for color, the test results are listed in Table 1. The NCO value was measured in accordance with HG/T2109 "determination of isocyanate content in polyurethane prepolymer".
The free TDI was determined according to GB T18446-.
The viscosity was measured using a rheometer. 50g of prepolymer is placed in a dry single-neck flask, nitrogen is filled in the flask for sealing, and no air contact is ensured. And (3) placing the flask with the prepolymer in an oven at 80 ℃, taking out after 24 hours, cooling to room temperature for viscosity test, comparing the change of viscosity before and after heating and aging, and evaluating the thermal stability of the viscosity.
Example 2
The embodiment provides a low-free TDI prepolymer, which is prepared from the following raw materials in parts by weight: and 70 parts of toluene diisocyanate. 180 parts of polyether polyol, 0.05 part of stabilizer, 0.2 part of antioxidant and 10 parts of entrainer, wherein isocyanate is TDI; the polyether polyol is PTMEG650s, the stabilizer is citric acid, the antioxidant is BASF 1010, and the entrainer is diphenylmethane.
The preparation method of the prepolymer with low free TDI in the embodiment comprises the following steps:
(1) putting PTMEG polyether polyol into a reaction kettle, setting the stirring speed at 200r/min, the temperature at 110 ℃ and the pressure at 400pa, dehydrating for 3h in vacuum under the condition, and testing the water content to be lower than 0.05%;
(2) cooling the reaction kettle to 50 ℃, introducing nitrogen for protection, simultaneously adding an antioxidant and a stabilizer, and stirring at constant temperature for 0.5 h;
(3) adding toluene diisocyanate, introducing nitrogen for protection, stirring and reacting at the constant temperature of 60 ℃ for 1h, heating to 80 ℃, and stirring and reacting at the constant temperature for 2 h;
(4) cooling to 50 deg.C, adding entrainer, and stirring at constant temperature for 30 min;
(5) adding the prepolymer into a molecular distillation device, setting the preheating feeding temperature to be 80 ℃, the main heating temperature to be 110 ℃, the condensing temperature to be 40 ℃, the vacuum degree to be 5pa, the film scraping speed to be 400r/min, controlling the feeding speed to be 0.8L/min, and collecting a product from heavy components, namely the low-free prepolymer.
The resulting prepolymer was tested for NCO value, free TDI and viscosity and observed for color, the test results are listed in Table 1. The NCO value was measured in accordance with HG/T2109 "determination of isocyanate content in polyurethane prepolymer".
The free TDI was determined according to GB T18446-.
The viscosity was measured using a rheometer.
50g of prepolymer is placed in a dry single-neck flask, nitrogen is filled in the flask for sealing, and no air contact is ensured. And (3) placing the flask with the prepolymer in an oven at 80 ℃, taking out after 24 hours, cooling to room temperature for viscosity test, comparing the change of viscosity before and after heating and aging, and evaluating the thermal stability of the viscosity.
Example 3
The embodiment provides a low-free TDI prepolymer, which is prepared from the following raw materials in parts by weight: 106 parts of toluene diisocyanate. 240 parts of polyether polyol, 0.005 part of stabilizer, 0.5 part of antioxidant and 5 parts of entrainer, wherein isocyanate is TDI; the polyether polyol is basf PTMEG650s, the stabilizer is citric acid, the antioxidant is basf 1010, and the entrainer is diphenylmethane.
The preparation method of the prepolymer with low free TDI in the embodiment comprises the following steps:
(1) putting PTMEG polyether polyol into a reaction kettle, setting the stirring speed at 200r/min, the temperature at 110 ℃ and the pressure at 400pa, dehydrating for 3h in vacuum under the condition, and testing the water content to be lower than 0.05%;
(2) cooling the reaction kettle to 50 ℃, introducing nitrogen for protection, simultaneously adding an antioxidant and a stabilizer, and stirring at constant temperature for 0.5 h;
(3) adding toluene diisocyanate, introducing nitrogen for protection, stirring and reacting at the constant temperature of 60 ℃ for 1h, heating to 75 ℃, and stirring and reacting at the constant temperature for 2 h;
(4) cooling to 50 deg.C, adding entrainer, and stirring at constant temperature for 30 min;
(5) adding the prepolymer into a molecular distillation device, setting the preheating feeding temperature to be 70 ℃, the main heating temperature to be 120 ℃, the condensing temperature to be 40 ℃, the vacuum degree to be 5pa, the film scraping speed to be 400r/min, controlling the feeding speed to be 0.5L/min, and collecting a product from heavy components, namely the low-free prepolymer.
The resulting prepolymer was tested for NCO value, free TDI and viscosity and observed for color, the test results are listed in Table 1. The NCO value was measured in accordance with HG/T2109 "determination of isocyanate content in polyurethane prepolymer".
The free TDI was determined according to GB T18446-.
The viscosity was measured using a rheometer.
50g of prepolymer is placed in a dry single-neck flask, nitrogen is filled in the flask for sealing, and no air contact is ensured. And (3) placing the flask with the prepolymer in an oven at 80 ℃, taking out after 24 hours, cooling to room temperature for viscosity test, comparing the change of viscosity before and after heating and aging, and evaluating the thermal stability of the viscosity.
Comparative example 1
The embodiment provides a low-free TDI prepolymer, which is prepared from the following raw materials in parts by weight: 140 parts of toluene diisocyanate. 220 parts of polyether polyol, 0.005 part of stabilizer, 0.5 part of antioxidant and 5 parts of entrainer, wherein isocyanate is TDI; the polyether polyol is basf's PTMEG650s, the stabilizer is phosphoric acid, the antioxidant is basf's 1010, and the entrainer is diphenylmethane.
The preparation method of the prepolymer with low free TDI in the embodiment comprises the following steps:
(1) putting PTMEG polyether polyol into a reaction kettle, setting the stirring speed at 200r/min, the temperature at 110 ℃ and the pressure at 400pa, dehydrating for 3h in vacuum under the condition, and testing the water content to be lower than 0.05%;
(2) cooling the reaction kettle to 50 ℃, introducing nitrogen for protection, simultaneously adding an antioxidant and a stabilizer, and stirring at constant temperature for 0.5 h;
(3) adding toluene diisocyanate, introducing nitrogen for protection, stirring and reacting at the constant temperature of 60 ℃ for 1h, heating to 75 ℃, and stirring and reacting at the constant temperature for 2 h;
(4) cooling to 50 deg.C, adding entrainer, and stirring at constant temperature for 30 min;
(5) adding the prepolymer into a molecular distillation device, setting the preheating feeding temperature to be 80 ℃, the main heating temperature to be 130 ℃, the condensing temperature to be 40 ℃, the vacuum degree to be 5pa, the film scraping speed to be 400r/min, controlling the feeding speed to be 1.0L/min, and collecting a product from heavy components, namely the low-free prepolymer; the content of free TDI is higher than 0.5 percent and is too high.
The resulting prepolymer was tested for NCO value, free TDI and viscosity and observed for color, the test results are listed in Table 1. The NCO value was measured in accordance with HG/T2109 "determination of isocyanate content in polyurethane prepolymer".
The free TDI was determined according to GB T18446-.
The viscosity was measured using a rheometer.
50g of prepolymer is placed in a dry single-neck flask, nitrogen is filled in the flask for sealing, and no air contact is ensured. And (3) placing the flask with the prepolymer in an oven at 80 ℃, taking out after 24 hours, cooling to room temperature for viscosity test, comparing the change of viscosity before and after heating and aging, and evaluating the thermal stability of the viscosity.
Comparative example 2
The embodiment provides a low-free TDI prepolymer, which is prepared from the following raw materials in parts by weight: 120 parts of toluene diisocyanate. 270 parts of polyether polyol, 0.005 part of stabilizer, 0.5 part of antioxidant and 5 parts of entrainer, wherein isocyanate is TDI; the polyether polyol is basf PTMEG650s, the stabilizer is citric acid, the antioxidant is basf 1010, and the entrainer is diphenylmethane.
The preparation method of the prepolymer with low free TDI in the embodiment comprises the following steps:
(1) putting PTMEG polyether polyol into a reaction kettle, setting the stirring speed at 200r/min, the temperature at 110 ℃ and the pressure at 400pa, dehydrating for 3h in vacuum under the condition, and testing the water content to be lower than 0.05%;
(2) cooling the reaction kettle to 50 ℃, introducing nitrogen for protection, simultaneously adding an antioxidant and a stabilizer, and stirring at constant temperature for 0.5 h;
(3) adding toluene diisocyanate, introducing nitrogen for protection, stirring and reacting at the constant temperature of 60 ℃ for 1h, heating to 75 ℃, and stirring and reacting at the constant temperature for 2 h;
(4) cooling to 50 deg.C, adding entrainer, and stirring at constant temperature for 30 min;
(5) adding the prepolymer into a molecular distillation device, setting a preheating feeding temperature of 70 ℃, a main heating temperature of 130 ℃, a condensing temperature of 40 ℃, a vacuum degree of 5pa, a film scraping speed of 400r/min, controlling a feeding speed of 0.5L/min, and collecting a product from heavy components, namely the low-free prepolymer; the content of free TDI is higher than 0.5 percent and is too high.
The resulting prepolymer was tested for NCO value, free TDI and viscosity and observed for color, the test results are listed in Table 1. The NCO value was measured in accordance with HG/T2109 "determination of isocyanate content in polyurethane prepolymer".
The free TDI was determined according to GB T18446-.
The viscosity was measured using a rheometer.
50g of prepolymer is placed in a dry single-neck flask, nitrogen is filled in the flask for sealing, and no air contact is ensured. And (3) placing the flask with the prepolymer in an oven at 80 ℃, taking out after 24 hours, cooling to room temperature for viscosity test, comparing the change of viscosity before and after heating and aging, and evaluating the thermal stability of the viscosity.
Comparative example 3
The embodiment provides a low-free TDI prepolymer, which is prepared from the following raw materials in parts by weight: 240 parts of toluene diisocyanate. 140 parts of polyether polyol, 0.005 part of stabilizer, 0.5 part of antioxidant and 5 parts of entrainer, wherein isocyanate is TDI; the polyether polyol is basf's PTMEG650s, the stabilizer is phosphoric acid, the antioxidant is basf's 1010, and the entrainer is diphenylmethane.
The preparation method of the prepolymer with low free TDI in the embodiment comprises the following steps:
(1) putting PTMEG polyether polyol into a reaction kettle, setting the stirring speed at 200r/min, the temperature at 110 ℃ and the pressure at 400pa, dehydrating for 3h in vacuum under the condition, and testing the water content to be lower than 0.05%;
(2) cooling the reaction kettle to 50 ℃, introducing nitrogen for protection, simultaneously adding an antioxidant and a stabilizer, and stirring at constant temperature for 0.5 h;
(3) adding toluene diisocyanate, introducing nitrogen for protection, stirring and reacting at the constant temperature of 60 ℃ for 1h, heating to 75 ℃, and stirring and reacting at the constant temperature for 2 h;
(4) cooling to 50 deg.C, adding entrainer, and stirring at constant temperature for 30 min;
(5) adding the prepolymer into a molecular distillation device, setting the preheating feeding temperature to be 80 ℃, the main heating temperature to be 120 ℃, the condensing temperature to be 40 ℃, the vacuum degree to be 5pa, the film scraping speed to be 400r/min, controlling the feeding speed to be 1.0L/min, and collecting a product from heavy components, namely the low-free prepolymer; the content of free TDI is higher than 0.5 percent and is too high.
The resulting prepolymer was tested for NCO value, free TDI and viscosity and observed for color, the test results are listed in Table 1. The NCO value was measured in accordance with HG/T2109 "determination of isocyanate content in polyurethane prepolymer".
The free TDI was determined according to GB T18446-.
The viscosity was measured using a rheometer.
50g of prepolymer is placed in a dry single-neck flask, nitrogen is filled in the flask for sealing, and no air contact is ensured. And (3) placing the flask with the prepolymer in an oven at 80 ℃, taking out after 24 hours, cooling to room temperature for viscosity test, comparing the change of viscosity before and after heating and aging, and evaluating the thermal stability of the viscosity.
Comparative example 4
The embodiment provides a low-free TDI prepolymer, which is prepared from the following raw materials in parts by weight: 106 parts of toluene diisocyanate. 220 parts of polyether polyol, 0.001 part of stabilizer, 0.5 part of antioxidant and 5 parts of entrainer, wherein isocyanate is TDI; the polyether polyol is basf's PTMEG650s, the stabilizer is phosphoric acid, the antioxidant is basf's 1010, and the entrainer is diphenylmethane.
The preparation method of the prepolymer with low free TDI in the embodiment comprises the following steps:
(1) putting PTMEG polyether polyol into a reaction kettle, setting the stirring speed at 200r/min, the temperature at 110 ℃ and the pressure at 400pa, dehydrating for 3h in vacuum under the condition, and testing the water content to be lower than 0.05%;
(2) cooling the reaction kettle to 50 ℃, introducing nitrogen for protection, simultaneously adding an antioxidant and a stabilizer, and stirring at constant temperature for 0.5 h;
(3) adding toluene diisocyanate, introducing nitrogen for protection, stirring and reacting at the constant temperature of 60 ℃ for 1h, heating to 75 ℃, and stirring and reacting at the constant temperature for 2 h;
(4) cooling to 50 deg.C, adding entrainer, and stirring at constant temperature for 30 min;
(5) adding the prepolymer into a molecular distillation device, setting the preheating feeding temperature to be 80 ℃, the main heating temperature to be 120 ℃, the condensing temperature to be 40 ℃, the vacuum degree to be 5pa, the film scraping speed to be 400r/min, controlling the feeding speed to be 0.5L/min, and collecting a product from heavy components, namely the low-free prepolymer; the content of free TDI is low, but the color of the prepolymer is dark yellow, and the prepolymer has no practical value.
The resulting prepolymer was tested for NCO value, free TDI and viscosity and observed for color, the test results are listed in Table 1. The NCO value was measured in accordance with HG/T2109 "determination of isocyanate content in polyurethane prepolymer".
The free TDI was determined according to GB T18446-.
The viscosity was measured using a rheometer.
50g of prepolymer is placed in a dry single-neck flask, nitrogen is filled in the flask for sealing, and no air contact is ensured. And (3) placing the flask with the prepolymer in an oven at 80 ℃, taking out after 24 hours, cooling to room temperature for viscosity test, comparing the change of viscosity before and after heating and aging, and evaluating the thermal stability of the viscosity.
The NCO values, free TDI, viscosity after accelerated aging and color results for examples 1-3 and comparative examples 1-4 are given in the following table.
TABLE 1
As a result of comparative experiments, it was found that the TDI's in examples 1-3 were all less than 0.3%, the free TDI's in comparative examples 1-4 were not less than 0.3%, and comparative example 4 was darkened. The prepolymer in examples 1-3 has a low free TDI content of 0.07-0.25%, low viscosity, good thermal stability, good processing conditions, and high economic value.
It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.
Claims (10)
1. A low free TDI polyurethane prepolymer is characterized by comprising the following raw materials in parts by weight:
2. the low free TDI polyurethane prepolymer of claim 1, wherein said polyether polyol is at least one of a dihydroxy polyether polyol, a trihydroxy polyether polyol, and a tetrahydroxy polyether polyol.
3. The low free TDI polyurethane prepolymer of claim 2 wherein said dihydroxy polyether polyol has a molecular weight selected from the group consisting of 300 to 2000.
4. The low free TDI polyurethane prepolymer of claim 1, wherein said isocyanate is one of toluene diisocyanate, TDI80/20, and TDI 100.
5. The low free TDI polyurethane prepolymer of claim 1 wherein said stabilizer is selected from the group consisting of citric acid, phosphoric acid, benzoyl chloride, and adipic acid.
6. The low free TDI polyurethane prepolymer as recited in claim 1, wherein said entrainer has a boiling point between 200 ℃ and 300 ℃.
7. The low free TDI polyurethane prepolymer of claim 1 wherein said entrainer is selected from the group consisting of dimethyl phthalate, diphenylmethane, and dimethyl glycol ether.
8. A preparation method of a low free TDI polyurethane prepolymer is characterized by comprising the following steps:
s1, putting the polyether glycol into a reaction kettle, setting the stirring speed at 200-;
s2, when the water content is lower than 0.05% in the step S1, cooling the inside of the reaction kettle to 50 ℃, introducing nitrogen for protection, adding an antioxidant and a stabilizer at the same time, and stirring at constant temperature for 0.5 h;
s3, adding isocyanate, introducing nitrogen for protection, stirring and reacting at a constant temperature of 60 ℃ for 1h, heating to 75 ℃, stirring and reacting at a constant temperature for 2 h;
s4, cooling to 50-60 ℃, adding an azeotropic agent, and stirring at constant temperature for 15-30 min;
s5, adding the prepolymer into a molecular distillation device, setting the preheating feeding temperature at 70-100 ℃, the main heating temperature at 90-150 ℃, the condensing temperature at 30-60 ℃, the vacuum degree at 1-30pa, the film scraping speed at 300-500r/min, controlling the feeding speed at 0.5-1.5L/min, the light component being a mixture of free TDI and auxiliary agent, and the heavy component being a product collected, namely the low free toluene diisocyanate prepolymer.
9. The method of claim 8, wherein the preheating feed temperature is 80 ℃, the main heating temperature is 130 ℃, the condensing temperature is 50 ℃, the vacuum degree is 5pa, the film scraping speed is 400r/min, and the feed speed is controlled to be 0.5L/min in step S5.
10. The method of claim 7, wherein the molecular distillation apparatus has an evaporation area of 600cm2。
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115850653A (en) * | 2022-09-30 | 2023-03-28 | 广东爱上体育产业股份有限公司 | Full TDI prepolymer with low free monomer content for pu runway and preparation method thereof |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4385171A (en) * | 1982-04-30 | 1983-05-24 | Olin Corporation Research Center | Removal of unreacted diisocyanate from polyurethane prepolymers |
-
2021
- 2021-12-07 CN CN202111489410.3A patent/CN114230742A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4385171A (en) * | 1982-04-30 | 1983-05-24 | Olin Corporation Research Center | Removal of unreacted diisocyanate from polyurethane prepolymers |
Non-Patent Citations (1)
| Title |
|---|
| 蒋树会: "多种聚氨酯预聚体的合成与应用", 《化学推进剂与高分子材料》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115850653A (en) * | 2022-09-30 | 2023-03-28 | 广东爱上体育产业股份有限公司 | Full TDI prepolymer with low free monomer content for pu runway and preparation method thereof |
| CN115850653B (en) * | 2022-09-30 | 2023-08-29 | 广东爱上新材料股份有限公司 | Full TDI prepolymer with low free monomer content for pu runway and preparation method thereof |
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