阅读说明：本技术 一种高耐热性的聚氨酯密封胶及其制备方法 (High-heat-resistance polyurethane sealant and preparation method thereof ) 是由 娄春华 王灏 施惠红 孟令阳 闫安 庄宝 王晶 于 2019-09-19 设计创作，主要内容包括：一种高耐热性的聚氨酯密封胶及其制备方法,本发明涉及聚氨酯密封胶及其制备方法。本发明要解决现有方法制备的聚氨酯密封胶耐热性不佳的问题。一种高耐热性的聚氨酯密封胶由聚醚三元醇、树枝状聚酯多元醇、含苯多异氰酸酯、催化剂和填料制备而成。方法将聚醚三元醇、含苯多异氰酸酯和树枝状聚酯多元醇加入到三颈瓶中,通入氮气进行聚合反应,得到聚氨酯预聚体,然后向聚氨酯预聚体中依次加入催化剂及填料,密封搅拌,真空脱泡。本发明用于高耐热性的聚氨酯密封胶及其制备。(the invention discloses a high-heat-resistance polyurethane sealant and a preparation method thereof, and relates to a polyurethane sealant and a preparation method thereof. The invention aims to solve the problem that the heat resistance of the polyurethane sealant prepared by the existing method is poor. A high-heat-resistance polyurethane sealant is prepared from polyether triol, dendritic polyester polyol, benzene-containing polyisocyanate, a catalyst and a filler. Adding polyether triol, benzene-containing polyisocyanate and dendritic polyester polyol into a three-necked bottle, introducing nitrogen to perform polymerization reaction to obtain a polyurethane prepolymer, sequentially adding a catalyst and a filler into the polyurethane prepolymer, sealing, stirring and defoaming in vacuum. The invention is used for the polyurethane sealant with high heat resistance and the preparation thereof.)

1. a high heat-resistant polyurethane sealant is characterized in that the sealant is prepared from polyether triol, dendritic polyester polyol, benzene-containing polyisocyanate, a catalyst and a filler;

The ratio of the total mole number of the hydroxyl of the polyether triol and the hydroxyl of the dendritic polyester polyol to the mole number of the isocyanate group containing the benzene polyisocyanate is 1 (1.3-1.5); the molar ratio of the hydroxyl of the polyether triol to the hydroxyl of the dendritic polyester polyol is 1 (0.01-0.143);

the mass percent of the catalyst in the polyurethane sealant with high heat resistance is 0.005-0.5%;

The high heat resistance polyurethane sealant comprises 0.08-20% of filler by mass.

2. the highly heat resistant polyurethane sealant according to claim 1, wherein the benzene-containing polyisocyanate is toluene diisocyanate, diphenylmethane diisocyanate or polyphenyl polyisocyanate.

3. the highly heat resistant polyurethane sealant according to claim 1, wherein the catalyst is one or a mixture of dibutyltin dilaurate, tertiary amine catalyst and morpholine catalyst.

4. The highly heat resistant polyurethane sealant according to claim 1, wherein the filler is light CaCO3, carbon black, kaolin or talc.

5. the polyurethane sealant with high heat resistance as claimed in claim 1, wherein the ratio of the total moles of the hydroxyl groups of the polyether triol and the dendritic polyester polyol to the moles of the isocyanate groups containing the benzene polyisocyanate is 1 (1.4-1.5).

6. The method of claim 1 for preparing a highly heat resistant polyurethane sealant, which comprises the steps of:

adding polyether triol, benzene-containing polyisocyanate and dendritic polyester polyol into a three-necked bottle, introducing nitrogen, carrying out polymerization reaction at the temperature of 80-85 ℃, taking a drop of reaction liquid every 30min to determine the content of isocyanate groups, stopping the polymerization reaction when the mass percent of the isocyanate groups in the reaction liquid is 3-5% to obtain a polyurethane prepolymer, then sequentially adding a catalyst and a filler into the polyurethane prepolymer, carrying out sealed stirring, and carrying out vacuum defoaming to obtain the high-heat-resistance polyurethane sealant;

The ratio of the total mole number of the hydroxyl of the polyether triol and the hydroxyl of the dendritic polyester polyol to the mole number of the isocyanate group containing the phenyl polyisocyanate is 1 (1.3-1.5); the molar ratio of the hydroxyl of the polyether triol to the hydroxyl of the dendritic polyester polyol is 1 (0.01-0.143);

The mass percent of the catalyst in the polyurethane sealant with high heat resistance is 0.005-0.5%;

the mass percentage of the filler in the high heat-resistant polyurethane sealant is 0.08-20%.

7. The method for preparing a polyurethane sealant with high heat resistance as claimed in claim 6, wherein the said benzene-containing polyisocyanate is toluene diisocyanate, diphenylmethane diisocyanate or polyphenyl polyisocyanate.

8. the method for preparing the polyurethane sealant with high heat resistance as claimed in claim 6, wherein the catalyst is one or a mixture of dibutyltin dilaurate, tertiary amine catalyst and morpholine catalyst.

9. The method for preparing polyurethane sealant with high heat resistance as claimed in claim 6, wherein the filler is light CaCO3, carbon black, kaolin or talc.

10. the preparation method of the polyurethane sealant with high heat resistance as claimed in claim 6, wherein the ratio of the total moles of the hydroxyl groups of the polyether triol and the dendritic polyester polyol to the moles of the isocyanate groups containing the benzene polyisocyanate is 1 (1.4-1.5).

Technical Field

The invention relates to a polyurethane sealant and a preparation method thereof.

Background

The development of the polyurethane sealant has been over 50 years in history, the research work of the polyurethane sealant is carried out in 50 years of 20 th century abroad, and various polyurethane sealants in Japan and America have been industrially produced in 60 years. For example, one-component and two-component polyurethane sealants were commercially produced in japan in 1967 and 1970, respectively. Two-component and one-component polyurethane sealants have been used in adhesive assembly of automotive windshields by japan and united states companies at the end of the last 70 th century. After that, the performances of the polyurethane sealant, such as heat resistance, aging resistance and the like, are continuously improved abroad. In order to improve the heat resistance of polyurethane sealants, researchers adopt methods of increasing the functionality and molecular weight of polyol reaction, adding heat-resistant fillers and the like. The increase of the functionality and the molecular weight of the polyol generally increases the viscosity of a system, so that the addition amount of the filler is reduced, the heat resistance of the polyurethane sealant is affected, and the heat resistance is only 90 ℃ at most.

Disclosure of Invention

The invention provides a high-heat-resistance polyurethane sealant and a preparation method thereof, aiming at solving the problem that the heat resistance of the polyurethane sealant prepared by the existing method is poor.

a high heat-resistant polyurethane sealant is prepared from polyether triol, dendritic polyester polyol, benzene-containing polyisocyanate, a catalyst and a filler;

the ratio of the total mole number of the hydroxyl of the polyether triol and the hydroxyl of the dendritic polyester polyol to the mole number of the isocyanate group containing the benzene polyisocyanate is 1 (1.3-1.5); the molar ratio of the hydroxyl of the polyether triol to the hydroxyl of the dendritic polyester polyol is 1 (0.01-0.143);

The mass percent of the catalyst in the polyurethane sealant with high heat resistance is 0.005-0.5%;

the mass percentage of the filler in the high heat-resistant polyurethane sealant is 0.08-20%.

A preparation method of a high heat-resistant polyurethane sealant comprises the following steps:

adding polyether triol, benzene-containing polyisocyanate and dendritic polyester polyol into a three-necked bottle, introducing nitrogen, carrying out polymerization reaction at the temperature of 80-85 ℃, taking a drop of reaction liquid every 30min to determine the content of isocyanate groups, stopping the polymerization reaction when the mass percent of the isocyanate groups in the reaction liquid is 3-5% to obtain a polyurethane prepolymer, then sequentially adding a catalyst and a filler into the polyurethane prepolymer, carrying out sealed stirring, and carrying out vacuum defoaming to obtain the high-heat-resistance polyurethane sealant;

The ratio of the total mole number of the hydroxyl of the polyether triol and the hydroxyl of the dendritic polyester polyol to the mole number of the isocyanate group containing the benzene polyisocyanate is 1 (1.3-1.5); the molar ratio of the hydroxyl of the polyether triol to the hydroxyl of the dendritic polyester polyol is 1 (0.01-0.143);

the mass percent of the catalyst in the polyurethane sealant with high heat resistance is 0.005-0.5%;

The mass percentage of the filler in the high heat-resistant polyurethane sealant is 0.08-20%.

The invention has the beneficial effects that:

The dendritic polyester polyol has the advantages of unique structure, good flowing property, unique viscosity behavior, good heat resistance and the like, but is introduced into the single-component polyurethane sealant due to high functionality, so that the 'implosion' is easily caused in the preparation process of the polyurethane sealant, and the quantity of functional groups participating in the reaction of the dendritic polyester polyol is difficult to control due to the large steric hindrance effect of the dendritic polyester polyol, so that the dendritic polyester polyol cannot be applied to the modification of the single-component polyurethane sealant in the prior art. On the premise of not influencing the excellent adhesiveness of the polyurethane sealant, the invention prepares the single-component high-temperature-resistant polyurethane sealant, introduces the dendritic structure into the polyurethane sealant, and utilizes the advantages of unique structure, good flowing property, unique viscosity behavior, good heat resistance and the like to realize the high-temperature resistance of the sealant. Because the invention is a single-component moisture curing reason, the polymerization reaction is stopped when the content of the isocyanate group is controlled to be 3-5% in the preparation process, so as to achieve the effect of curing in the air.

The sealing shear strength of the prepared polyurethane is greater than 7MPa, the heat resistance of the adhesive can reach 140 ℃, the adhesive is aged for 2 hours at 140 ℃, the elongation at break can reach 114%, the tensile strength can reach 0.7MPa, and the 180-degree peel strength can reach 6 kN/m.

The invention relates to a high-heat-resistance polyurethane sealant and a preparation method thereof.

Detailed Description

The technical solution of the present invention is not limited to the specific embodiments listed below, and includes any combination of the specific embodiments.