Anti-yellowing and anti-aging single-component transparent sealant and preparation method thereof

Abstract

The invention discloses an anti-yellowing and anti-aging single-component transparent sealant and a preparation method thereof, and the anti-yellowing and anti-aging single-component transparent sealant comprises the following components in parts by mass: 100 parts of terminated polydimethylsiloxane; 1 part of a dispersant; 3 to 10 parts of N, N '-bis-(3-(3, 5-di-tert-butyl-4-hydroxyphenyl) propionyl) hexamethylenediamine; 1 to 10 parts of dimethyl silicone oil; 70 to 140 parts of fumed silica; 3-10 parts of a cross-linking agent; 2-8 parts of a compound coupling agent; and 2-6 parts of a catalyst. The sealant disclosed by the invention has the advantages of yellowing resistance and aging resistance, and small molecules released in the curing process are alcohol small molecules, so that the sealant has the advantage of environmental friendliness; the sealant does not have a neutral curing system, has no corrosion to building materials such as metal, glass and concrete, and is wide in application.

Description

Technical Field

[0001] The invention relates to the technical field of sealants, and in particular to a yellowing-resistant and aging-resistant single-component transparent sealant and a preparation method thereof. Background Art

[0002] Single-component dealcoholized silicone sealant is the main type of silicone sealant at present. It has simple construction performance, low toxicity and no odor, and is applicable to a wide range of substrates. It is the type with the largest output and sales in the current building materials market. The color of the traditional single-component transparent sealant on the market will turn yellow after long-term exposure to the sun, and its tensile bonding performance will also decrease, affecting the beauty and service life of the building. With the improvement of special requirements of users in domestic decoration and other application fields, users tend to recommend transparent sealants that do not change color and are resistant to aging.

[0003] Patent No. CN116239991A uses end-capped polydimethylsiloxane, inorganic filler, reinforcing filler, cross-linking agent, catalyst, and coupling agent as raw materials to prepare a fast-curing dealcoholized silicone sealant that can significantly increase the curing speed and effectively avoid the yellowing problem of the sealant during construction and use. This solution uses a dual catalytic system and the production process is relatively complicated. Patent No. CN114149782B uses base glue, silicone oil, white carbon black, white oil, acidic cross-linking agent, coupling agent, and catalyst to prepare an acidic sealant, which requires the acidic cross-linking agent to react with the coupling agent to obtain a pre-reactant, and then the pre-reactant is mixed with other components. The acidic silicone sealant has good yellowing resistance. Its process is relatively complicated and has a pungent odor, and the user acceptance is not high.

[0004] In view of the problems of yellowing and poor aging performance of conventional one-component transparent sealants, the present invention prepares a one-component transparent sealant, which can simultaneously improve the yellowing resistance and aging resistance of the one-component silicone sealant, and can expand the application of this type of one-component transparent sealant in more scenarios. Summary of the invention

[0005] In view of the above-mentioned shortcomings that currently exist, the present invention provides a single-component transparent sealant that is resistant to yellowing and aging and a preparation method thereof. The sealant of the present invention has the advantages of being resistant to yellowing and aging, and the small molecules released during the curing process are alcohol small molecules, so it has the advantage of being environmentally friendly; the sealant of the present invention has a non-neutral curing system, is non-corrosive to building materials such as metal, glass, and concrete, and is widely used.

[0006] In order to achieve the above object, the present invention provides a yellowing-resistant and aging-resistant one-component transparent sealant, which comprises the following components in parts by mass:

[0007]

[0008] According to one aspect of the present invention, the end-capped polydimethylsiloxane is triethoxy end-capped polydimethylsiloxane.

[0009] According to one aspect of the present invention, the dispersant includes one or more of polyacrylamide, polyvinyl pyrrolidone, stearic acid, sodium lauryl sulfate, and citric acid.

[0010] According to one aspect of the present invention, the viscosity of the dimethyl silicone oil at 25° C. is 0.1 Pa.s to 10 Pa.s.

[0011] According to one aspect of the present invention, the fumed silica is hydrophobic fumed silica with a particle size of 10 to 40 nm.

[0012] According to one aspect of the present invention, the crosslinking agent includes one or more of ethyl orthosilicate, propyl orthosilicate, polyethyl silicate, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, polymethyltriethoxysilane oligomer, phenyltrimethoxysilane, phenyltriethoxysilane, methylphenyldimethoxysilane, methylphenyldiethoxysilane, diphenyldimethoxysilane, and diphenyldiethoxysilane.

[0013] According to one aspect of the present invention, the complex coupling agent includes one or more of γ-glycidyloxypropyltrimethoxysilane, γ-glycidyloxypropyltrimethoxysilane, epoxycyclohexylmethyldimethoxysilane, chloropropyltrimethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysiloxane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, anilinomethyltrimethoxysilane, γ-isocyanatepropyltrimethoxysilane, epoxypropyltrimethoxysilane, and divinyltriaminopropyltrimethoxysilane.

[0014] According to one aspect of the present invention, the catalyst is one or more of dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dioctoate, and tin octoate.

[0015] Based on the same inventive concept, the present invention also provides a method for preparing the above-mentioned anti-yellowing and anti-aging one-component transparent sealant, comprising the following steps:

[0016] S1. Add end-capped polydimethylsiloxane, dimethyl silicone oil, dispersant, and N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine into a high-speed disperser, and blend at room temperature for 10 to 30 minutes to obtain a suspension;

[0017] S2, adding fumed silica into the high-speed disperser, the vacuum degree is -0.06 to 0.099 MPa, blending for 30 to 300 minutes, and then adding the crosslinking agent into the high-speed disperser at a vacuum degree of -0.02 to 0.04 MPa and a rotation speed of 10 to 800 rpm for chemical reaction for 5 to 30 minutes to obtain a base material;

[0018] S3. Finally, the complex coupling agent and the catalyst are added into the high-speed disperser together with the base material, and the mixture is subjected to a chemical reaction for 30 to 120 minutes at a vacuum degree of -0.06 to 0.099 MPa and a rotation speed of 10 to 800 rpm to obtain a single-component transparent sealant that is resistant to yellowing and aging.

[0019] Beneficial effects of the present invention:

[0020] (1) In the present invention, after adding a dispersant and N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine) to the sealant, the yellowing resistance and aging resistance of the sealant are improved;

[0021] (2) The preparation method of the present invention allows N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine to be well dispersed in the base material, and the process flow is simple;

[0022] (3) The small molecules released during the curing process of the sealant of the present invention are alcohol small molecules, so it has the advantage of being environmentally friendly; the sealant of the present invention has a non-neutral curing system and is non-corrosive to building materials such as metal, glass, and concrete, and is widely used. DETAILED DESCRIPTION

[0023] To make the present invention easier to understand, the present invention is further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention. Unless otherwise defined, the professional terms used below are consistent with the meanings understood by professional and technical personnel in the field; unless otherwise specified, the raw materials and reagents involved in this article can be purchased from the market or prepared by known methods.

[0024] Example 1

[0025] A yellowing-resistant and aging-resistant one-component transparent sealant and a preparation method thereof, comprising the following steps:

[0026] First, 100 parts of end-capped polydimethylsiloxane with a viscosity of 50000 mPa·s, 5 parts of dimethyl silicone oil with a viscosity of 350 mPa·s, 1 part of polyacrylamide, and 3 parts of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine) were added into a high-speed disperser and stirred at room temperature for 20 minutes to form a uniformly dispersed suspension;

[0027] Then, 110 parts of 30nm fumed silica were added to a high-speed disperser, and the mixture was blended for 120 minutes at a vacuum degree of -0.09MPa; then, 5 parts of polymethyltriethoxysilane oligomer were added, and the mixture was chemically reacted for 15 minutes at a vacuum degree of 0.04MPa and a rotation speed of 300rpm to obtain a base material;

[0028] Finally, 6 parts of γ-aminopropyl trimethoxysilane, 0.5 parts of γ-glycidyloxypropyl trimethoxysilane, and 3 parts of dibutyltin dioctanoate were added to carry out chemical reaction for 40 minutes under the conditions of vacuum degree of -0.09MPa and rotation speed of 300rpm to prepare silicone sealant (anti-yellowing, anti-aging single-component transparent sealant). The parts of the dispersant, N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl) hexanediamine, crosslinking agent, and complex crosslinking agent are shown in Table 1.

[0029] Example 2

[0030] A yellowing-resistant and aging-resistant one-component transparent sealant and a preparation method thereof, comprising the following steps:

[0031] First, 100 parts of triethoxy-terminated polydimethylsiloxane with a viscosity of 50000 mPa·s, 5 parts of dimethyl silicone oil with a viscosity of 350 mPa·s, 1 part of polyacrylamide, and 5 parts of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine) were added into a high-speed disperser and stirred at room temperature for 20 minutes to form a uniformly dispersed suspension;

[0032] Then, 110 parts of 30nm fumed silica were added to a high-speed disperser, and dehydrated and blended for 120 minutes at a vacuum degree of -0.09MPa; then, 5 parts of polymethyltriethoxysilane oligomer were added, and a chemical reaction was carried out for 15 minutes at a vacuum degree of 0.04MPa and a rotation speed of 300rpm to obtain a base material;

[0033] Finally, 6 parts of γ-aminopropyl trimethoxysilane, 0.5 parts of γ-glycidyloxypropyl trimethoxysilane, and 3 parts of dibutyltin dioctanoate were added to carry out chemical reaction for 40 minutes under the conditions of vacuum degree of -0.09MPa and rotation speed of 300rpm to prepare silicone sealant (anti-yellowing, anti-aging single-component transparent sealant). The parts of the dispersant, N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl) hexanediamine, crosslinking agent, and complex crosslinking agent are shown in Table 1.

[0034] Example 3

[0035] A yellowing-resistant and aging-resistant one-component transparent sealant and a preparation method thereof, comprising the following steps:

[0036] First, 100 parts of end-capped polydimethylsiloxane with a viscosity of 50000 mPa·s, 5 parts of dimethyl silicone oil with a viscosity of 350 mPa·s, 1 part of polyacrylamide, and 10 parts of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine) were added into a high-speed disperser and stirred at room temperature for 20 minutes to form a uniformly dispersed suspension;

[0037] Then, 110 parts of 30nm fumed silica were added to a high-speed disperser, and the mixture was blended for 120 minutes at a vacuum degree of -0.09MPa; then, 5 parts of polymethyltriethoxysilane oligomer were added, and the mixture was chemically reacted with the base material at a vacuum degree of 0.04MPa and a rotation speed of 300rpm for 15 minutes to obtain the base material;

[0038] Finally, 6 parts of γ-aminopropyl trimethoxysilane, 0.5 parts of γ-glycidyloxypropyl trimethoxysilane, and 3 parts of dibutyltin dioctanoate were added to carry out chemical reaction for 40 minutes under the conditions of vacuum degree of -0.09MPa and rotation speed of 300rpm to prepare silicone sealant (anti-yellowing, anti-aging single-component transparent sealant). The parts of the dispersant, N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl) hexanediamine, crosslinking agent, and complex crosslinking agent are shown in Table 1.

[0039] Comparative Example 1

[0040] A transparent sealant and a preparation method thereof, comprising the following steps:

[0041] First, 100 parts of end-capped polydimethylsiloxane with a viscosity of 50000 mPa·s, 5 parts of dimethyl silicone oil with a viscosity of 350 mPa·s, and 110 parts of 30 nm fumed silica were added to a high-speed disperser and blended for 120 minutes under a vacuum degree of -0.09 MPa;

[0042] Then add 5 parts of polymethyl triethoxysilane oligomer, and carry out chemical reaction with the base material at a vacuum degree of 0.04MPa and a rotation speed of 300rpm for 15 minutes; finally add 6 parts of γ-aminopropyl trimethoxysilane, 0.5 parts of γ-glycidyl ether oxypropyl trimethoxysilane, and 3 parts of dibutyl dioctanoate, and carry out chemical reaction for 40 minutes at a vacuum degree of -0.09MPa and a rotation speed of 300rpm to prepare silicone sealant. The parts of dispersant, N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl) hexanediamine, crosslinking agent and complex coupling agent are shown in Table 1.

[0043] Comparative Example 2

[0044] A transparent sealant and a preparation method thereof, comprising the following steps:

[0045] First, 100 parts of end-capped polydimethylsiloxane with a viscosity of 50000 mPa·s, 5 parts of dimethyl silicone oil with a viscosity of 350 mPa·s, 3 parts of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine, and 110 parts of 30 nm fumed silica were added to a high-speed disperser and blended for 120 minutes under a vacuum degree of -0.09 MPa.

[0046] Then 5 parts of polymethyl triethoxysilane oligomer were added, and the base material was chemically reacted at a vacuum degree of 0.04 MPa and a rotation speed of 300 rpm for 15 minutes. Finally, 6 parts of γ-aminopropyl trimethoxysilane, 0.5 parts of γ-glycidyl ether oxypropyl trimethoxysilane, and 3 parts of dibutyl dioctanoate were added, and the chemical reaction was carried out for 40 minutes at a vacuum degree of -0.09 MPa and a rotation speed of 300 rpm to prepare silicone sealant. The parts of the dispersant, N, N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl) hexanediamine, crosslinking agent, and complex coupling agent are shown in Table 1.

[0047] Table 1 List of ingredients of dispersant, N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine), crosslinking agent and complex crosslinking agent in Examples and Comparative Examples

[0048]

[0049] Performance testing and result analysis:

[0050] The surface drying time of the dealcoholized one-component silicone sealant in the above embodiments and comparative examples was tested according to the requirements of GB / T 13477.5. 23°C tensile adhesion: tested according to 5.9 of JG / T 475-2015. 90°C accelerated aging performance test: the specimen and the rubber strip were placed in a 90°C oven for accelerated aging for 14D, and then the tensile adhesion of the specimen was tested according to 5.9 of JG / T 475-2015. The sealant color change test was tested according to the requirements of GB / T 13477.21-2022, and the results are shown in Table 2 below.

[0051] Table 2 Performance test results of the embodiments and comparative examples

[0052]

[0053] As can be seen from Table 2, adding a small amount of dispersant and N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine will improve the aging resistance and yellowing resistance of the one-component transparent sealant, and its addition to the one-component sealant has little effect on the curing performance and conventional mechanical properties. By comparing Examples 1-3 and Comparative Example 1, it can be obtained that when dispersant and N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine are added to the transparent sealant, the tensile strength retention rate after aging at 90°C is increased from 64% to more than 80%, and no obvious yellowing occurs. By comparing Example 1 and Comparative Example 2, it can be obtained that after adding 1 part of dispersant, the dispersion of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine in the sealant can be improved, and its aging performance and yellowing performance can be greatly improved. By comparing Examples 1-3, it can be found that when an excessive amount of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine is added, the tensile strength decreases. This may be due to the uneven dispersion caused by excessive use, which leads to a decrease in the strength of the sealant. For this formula, the optimal amount of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine is 5 parts.

[0054] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the art within the technical scope disclosed in the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A one-component transparent sealant with anti-yellowing and anti-aging properties, characterized in that: According to the mass percentage, it includes the following components: 100 parts of blocked polydimethylsiloxane; 1 part of dispersant; 3 to 10 parts of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine); 2. The anti-yellowing and anti-aging one-component transparent sealant according to claim 1, characterized in that: The end-capped polydimethylsiloxane is triethoxy-end-capped polydimethylsiloxane.

3. The anti-yellowing and anti-aging one-component transparent sealant according to claim 1, characterized in that: The dispersant includes one or more of polyacrylamide, polyvinyl pyrrolidone, stearic acid, sodium lauryl sulfate, and citric acid.

4. The anti-yellowing and anti-aging one-component transparent sealant according to claim 1, characterized in that: The viscosity of the dimethyl silicone oil at 25° C. is 0.1 Pa.s to 10 Pa.s.

5. The anti-yellowing and anti-aging one-component transparent sealant according to claim 1, characterized in that: The fumed silica is hydrophobic fumed silica with a particle size of 10 to 40 nm.

6. The anti-yellowing and anti-aging one-component transparent sealant according to claim 1, characterized in that: The crosslinking agent includes one or more of ethyl orthosilicate, propyl orthosilicate, polyethyl silicate, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, polymethyltriethoxysilane oligomer, phenyltrimethoxysilane, phenyltriethoxysilane, methylphenyldimethoxysilane, methylphenyldiethoxysilane, diphenyldimethoxysilane, and diphenyldiethoxysilane.

7. The anti-yellowing and anti-aging one-component transparent sealant according to claim 6, characterized in that: The complex coupling agent includes one or more of γ-glycidyloxypropyltrimethoxysilane, γ-glycidyloxypropyltrimethoxysilane, epoxycyclohexylmethyldimethoxysilane, chloropropyltrimethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysiloxane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, anilinomethyltrimethoxysilane, γ-isocyanatepropyltrimethoxysilane, epoxypropyltrimethoxysilane, and divinyltriaminopropyltrimethoxysilane.

8. The anti-yellowing and anti-aging one-component transparent sealant according to claim 1, characterized in that: The catalyst is one or more of dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dioctoate, and tin octoate.

9. A method for preparing the anti-yellowing and anti-aging one-component transparent sealant according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Add end-capped polydimethylsiloxane, dimethyl silicone oil, dispersant, and N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine into a high-speed disperser, and blend at room temperature for 10 to 30 minutes to obtain a suspension; S2, adding fumed silica into the high-speed disperser, the vacuum degree is -0.06 to 0.099 MPa, blending for 30 to 300 minutes, and then adding the crosslinking agent into the high-speed disperser at a vacuum degree of -0.02 to 0.04 MPa and a rotation speed of 10 to 800 rpm for chemical reaction for 5 to 30 minutes to obtain a base material; S3. Finally, the complex coupling agent and the catalyst are added into the high-speed disperser together with the base material, and the mixture is subjected to a chemical reaction for 30 to 120 minutes at a vacuum degree of -0.06 to 0.099 MPa and a rotation speed of 10 to 800 rpm to obtain a single-component transparent sealant that is resistant to yellowing and aging.

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