An adhesive promoter for moisture-curing silicone resin and its preparation method and application

Abstract

The present disclosure provides a kind of for moisture hardening type silicon resin bonding promoter and its preparation method and application, belong to polymer material technical field.The bonding promoter of the present disclosure includes at least one of the compound shown in formula I structure: Wherein, R 1 It is one of hydrogen, C1-C20 alkyl, aryl;R 2 , R 3 Each independently methyl or ethyl;R 4 It is one of hydrogen, hydroxyl, C1-C20 alkyl;R 5 It is one of C1-C20 alkyl, C1-C20 alkyl substituted aryl;X is 1,3-methylene or 1,6-ethylenediamine propyl;a is 0, 1.The bonding promoter of the present disclosure is used in moisture hardening type silicon resin, can effectively improve the weather resistance and water bonding of moisture hardening type silicon resin.

Description

Technical Field

[0001] This disclosure relates to the field of polymer technology, specifically to an adhesion promoter for moisture-curing silicone resins, its preparation method, and its application. Background Technology

[0002] Moisture-curing silicone resin compositions exhibit excellent resistance to ultraviolet light, weathering, and high temperature and humidity. Compared to other types of sealants, their durability under harsh conditions is particularly outstanding, especially single-component room-temperature curing silicone sealants. Due to the relatively stable silicon-oxygen bonds in their main components, they possess excellent aging resistance and are widely used in construction, automotive, lighting, and electronics industries. While silicone sealants generally have excellent weather resistance, their adhesion to water gradually deteriorates or even fails after prolonged immersion in water or high humidity environments, thus losing their sealing and protective effects.

[0003] Moisture-curing silicone resin compositions typically possess low surface energy and exhibit good wettability to most substrates. Furthermore, the use of silane coupling agents such as aminosilanes and / or epoxysilanes as adhesion promoters further enhances their adhesion to most substrates. However, aminosilane coupling agents containing reactive primary amine groups exhibit an affinity for moisture due to the activity of the primary amines. Additionally, primary amines are more susceptible to oxidation reactions caused by ultraviolet light and oxygen compared to secondary amine groups, thus reducing their adhesion to the substrate. Therefore, it is necessary to continuously develop specific adhesion promoters to further improve the weather resistance and water-resistant adhesion of moisture-curing silicone resin compositions. Summary of the Invention

[0004] The purpose of this disclosure is to overcome the shortcomings of the prior art and provide an adhesion promoter for moisture-curing silicone resin, its preparation method and application. When used in moisture-curing silicone resin, the adhesion promoter can effectively improve the weather resistance and water-resistant adhesion of moisture-curing silicone resin.

[0005] To achieve the above objectives, the technical solution adopted in this disclosure is as follows: Firstly, an adhesion promoter for moisture-curing silicone resin is provided, wherein the adhesion promoter comprises at least one compound with the structure shown in Formula I:

[0006] ;

[0007] Among them, R 1 It is one of hydrogen, C1-C20 alkyl, or aryl; R 2 R 3 Each is independently methyl or ethyl; R 4 It is one of hydrogen, hydroxyl, or C1-C20 alkyl; R 5It is one of C1-C20 alkyl or C1-C20 alkyl-substituted aryl; X is 1,3-methylene or 1,6-ethylaminopropyl; a is 0 or 1.

[0008] In some embodiments, the adhesion promoter comprises at least one of the following compounds:

[0009] ; ;

[0010] ; .

[0011] Secondly, a method for preparing the aforementioned adhesion promoter for moisture-curing silicone resin is provided, comprising the following steps:

[0012] Formaldehyde and aminosilane coupling agent are dissolved in a solvent, then a catalyst is added and stirred until homogeneous. Next, salicylic acid ester is added, and the mixture is refluxed to obtain the reaction product. The reaction product is then post-treated to obtain the adhesion promoter. The molar ratio of salicylic acid ester:formaldehyde:aminosilane coupling agent is 1-3:1-3:1.

[0013] In some embodiments, the aminosilane coupling agent is at least one selected from aminopropyltrimethoxysilane, aminopropyltriethoxysilane, aminoethylaminopropyltrimethoxysilane, aminoethylaminopropyltriethoxysilane, aminopropylmethyldimethoxysilane, aminopropylmethyltriethoxysilane, aminoethylaminopropylmethyldimethoxysilane, and aminoethylaminopropylmethyldiethoxysilane.

[0014] In some embodiments, the catalyst is an acid, and the acid is at least one selected from hydrochloric acid, sulfuric acid, and trifluoroacetic acid;

[0015] In some embodiments, the salicylate is phenyl salicylate and / or homosalate;

[0016] In some embodiments, the solvent is an alcohol solvent.

[0017] Thirdly, the application of the adhesive accelerator for moisture-curing silicone resins is provided.

[0018] Fourthly, a moisture-curing silicone resin is provided, comprising the following components in parts by weight: 100 parts of polydimethylsiloxane, 1-10 parts of crosslinking agent, 5-100 parts of filler, 1-30 parts of plasticizer, 0.01-5 parts of catalyst, and 0.1-5 parts of the adhesion promoter.

[0019] In some embodiments, the polydimethylsiloxane is at least one of α,ω-dihydroxypolydimethylsiloxane and methyldimethoxy-terminated polydimethylsiloxane;

[0020] In some embodiments, the viscosity of the polydimethylsiloxane at 25°C is 1000-150000 mPa•s;

[0021] In some embodiments, the crosslinking agent is at least one of ketoxime silane and alkoxysilane;

[0022] In some embodiments, the filler is at least one selected from calcium carbonate, diatomaceous earth, quartz sand, and silica.

[0023] In some embodiments, the plasticizer is at least one of mineral oil and dimethyl silicone oil;

[0024] In some embodiments, the catalyst is at least one of organotin catalysts and organotitanium catalysts.

[0025] In some embodiments, the ketooxime silane is at least one selected from methyltributanone oxime silane, vinyltributanone oxime silane, and tetrabutanone oxime silane;

[0026] In some embodiments, the alkoxysilane is at least one selected from methyltrimethoxysilane, vinyltrimethoxysilane, propyltrimethoxysilane, methyl orthosilicate, and tetraethyl orthosilicate.

[0027] In some embodiments, the organotin catalyst is at least one of dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, stannous octoate, and dibutyltin diacetylacetonate.

[0028] In some embodiments, the organotitanium catalyst is at least one of tetrabutyl titanate, tetratert-butyl titanate, titanium diisopropoxydiacetylacetonate, and titanium diisopropoxydiacetylacetonate.

[0029] In some embodiments, the moisture-curing silicone resin further includes 0.01-5 parts by weight of a silane coupling agent, wherein the silane coupling agent is at least one selected from γ-epoxypropoxypropyltrimethoxysilane, γ-epoxypropoxypropyltriethoxysilane, 2-(3,4-epoxycyclohexane)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexane)ethyltriethoxysilane, γ-(epoxypropoxy)propylmethyltrimethoxysilane, and γ-(epoxypropoxy)propylmethyltriethoxysilane.

[0030] Fifthly, the application of the aforementioned moisture-curing silicone resin in sealants is provided.

[0031] Compared with the prior art, the beneficial effects of this disclosure are as follows:

[0032] (1) This disclosure involves adding a specific structured adhesion promoter to a moisture-curing silicone resin. Firstly, the salicylate ester structural unit in the adhesion promoter has ultraviolet absorption functionality, which can improve the weather resistance of the moisture-curing silicone resin. Secondly, compared with aminosilanes, the adhesion promoter containing the salicylate ester structural unit can improve the compatibility between the moisture-curing silicone resin and plastic substrates (such as PET), thereby improving the adhesion and water resistance of the moisture-curing silicone resin to the plastic substrate. Thirdly, the addition of an ultraviolet absorber to the moisture-curing silicone resin can improve the moisture-curing silicone resin's... The weather resistance of moisture-curing silicone resins is poor, with issues such as poor solubility, easy migration, and precipitation, leading to a decrease in the weather resistance and water-resistant adhesion of moisture-curing silicone resins. The silicon-containing groups in the adhesive accelerator of this invention improve the compatibility between ultraviolet absorbers and moisture-curing silicone resins, preventing the migration and precipitation of ultraviolet absorbers in moisture-curing silicone resins, and improving the weather resistance and water-resistant adhesion of moisture-curing silicone resins. Fourthly, compared with the primary amine groups in aminosilane coupling agents, the amine in the adhesive accelerator is a secondary amine group, which reduces the alkalinity of the adhesive accelerator and improves the water-resistant adhesion of moisture-curing silicone resins.

[0033] (2) The present invention uses bio-based salicylic acid esters to prepare adhesive accelerators, and the resulting adhesive accelerators have certain renewability, sustainability and environmental friendliness.

[0034] (3) The method for preparing the adhesive accelerator disclosed herein is a one-step synthesis method, which is simple to operate and easy to industrialize. Detailed Implementation

[0035] To facilitate understanding of this disclosure, a more complete description will be provided below. However, this disclosure may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure.

[0036] As used in this article:

[0037] "Prepared from" is synonymous with "comprising". The terms "comprising", "including", "having", "containing", or any other variations thereof as used herein are intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that includes the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such composition, step, method, article, or apparatus.

[0038] The conjunction "composed of..." excludes any unspecified elements, steps, or components. If used in a claim, this phrase makes the claim closed, excluding materials other than those described, except for associated conventional impurities. When the phrase "composed of..." appears in a clause of the body of a claim rather than immediately following it, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0039] When a quantity, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pair of any upper or preferred value with any lower or preferred value, regardless of whether the range is disclosed individually. For example, when the range “1-5” is disclosed, the described range should be interpreted as including ranges “1-4”, “1-3”, “1-2”, “1-2 and 4-5”, “1-3 and 5”, etc. When numerical ranges are described herein, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within that range.

[0040] In these embodiments, unless otherwise specified, the portions and percentages are all by weight.

[0041] "Parts by mass" refers to the basic unit of measurement that expresses the mass ratio of multiple components. One part can represent any unit mass, such as 1g or 2.689g. If we say that component A has "a" parts by mass and component B has "b" parts by mass, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it can mean that the mass of component A is aK and the mass of component B is bK (K is any number representing a multiplier). It is important to understand that, unlike the number of parts by mass, the sum of the mass parts of all components is not limited to 100 parts.

[0042] "And / or" is used to indicate that one or both of the described situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0043] To address the issues of poor weather resistance and water-resistant adhesion of moisture-curing silicone resins in existing technologies.

[0044] In a first aspect, this disclosure provides an adhesion promoter for moisture-curing silicone resins, said adhesion promoter comprising at least one of compounds with the structure shown in Formula I:

[0045] ;

[0046] Among them, R 1 It is one of hydrogen, C1-C20 alkyl, or aryl; R2 R 3 Each is independently methyl or ethyl; R 4 It is one of hydrogen, hydroxyl, or C1-C20 alkyl; R 5 It is one of C1-C20 alkyl or C1-C20 alkyl-substituted aryl; X is 1,3-methylene or 1,6-ethylaminopropyl; a is 0 or 1.

[0047] This disclosure involves adding a specific structured adhesion promoter to a moisture-curing silicone resin. Firstly, the salicylate structural unit in the adhesion promoter has ultraviolet absorption capabilities, thereby improving the weather resistance of the moisture-curing silicone resin. Secondly, compared to aminosilanes, the adhesion promoter containing the salicylate structural unit improves the compatibility of the moisture-curing silicone resin with plastic substrates (such as PET), thus enhancing the adhesion and water resistance between the moisture-curing silicone resin and the plastic substrate. Thirdly, the addition of an ultraviolet absorber to the moisture-curing silicone resin improves its weather resistance. The present invention has problems with poor solubility, easy migration and precipitation, which leads to a decrease in the weather resistance, adhesion and water-resistant adhesion of moisture-curing silicone resin. The silicon-containing group in the adhesion accelerator of the present invention improves the compatibility between ultraviolet absorber and moisture-curing silicone resin, avoids the migration and precipitation of ultraviolet absorber in moisture-curing silicone resin, and improves the weather resistance and water-resistant adhesion of moisture-curing silicone resin. Fourthly, compared with the primary amine group in aminosilane coupling agent, the amine in the adhesion accelerator is a secondary amine group, which reduces the alkalinity of the adhesion accelerator and improves the water-resistant adhesion of moisture-curing silicone resin.

[0048] In some embodiments, the adhesion promoter comprises at least one of the following compounds:

[0049] ; ;

[0050] ; .

[0051] When compounds with the above-mentioned structures are selected as adhesive promoters, the weather resistance and water-resistant adhesive properties of moisture-curing silicone resins can be further improved due to the further optimization of the groups contained in the structure.

[0052] Secondly, a method for preparing the aforementioned adhesion promoter is provided, comprising the following steps:

[0053] Formaldehyde and aminosilane coupling agent are dissolved in a solvent, then a catalyst is added and stirred until homogeneous. Next, salicylic acid ester is added, and the mixture is refluxed to obtain the reaction product. The reaction product is then post-treated to obtain the adhesion promoter. The molar ratio of salicylic acid ester:formaldehyde:aminosilane coupling agent is 1-3:1-3:1.

[0054] This disclosure utilizes a bio-based salicylate ester, reacting it with formaldehyde and aminosilane to obtain an adhesive accelerator containing salicylate ester structural units. The resulting adhesive accelerator exhibits certain renewability, sustainability, and environmental friendliness. The preparation method of this adhesive accelerator is a one-step synthesis method, with simple operation steps and easy industrial production.

[0055] Specifically, the molar ratio of salicylate ester:formaldehyde:aminosilane coupling agent can be, but is not limited to, 1:1:1, 1.5:1:1, 2:1:1, 2.5:1:1, 3:1:1, 1:1.5:1, 1:2:1, 1:2.5:1, 1:3:1, 2:2:1, or 3:3:1.

[0056] Specifically, the chemical equations for the reactions in the above preparation method are as follows:

[0057] .

[0058] In some embodiments, the aminosilane coupling agent is at least one selected from aminopropyltrimethoxysilane, aminopropyltriethoxysilane, aminoethylaminopropyltrimethoxysilane, aminoethylaminopropyltriethoxysilane, aminopropylmethyldimethoxysilane, aminopropylmethyltriethoxysilane, aminoethylaminopropylmethyldimethoxysilane, and aminoethylaminopropylmethyldiethoxysilane.

[0059] In some embodiments, the catalyst is an acid, which is at least one of hydrochloric acid, sulfuric acid, and trifluoroacetic acid.

[0060] Specifically, based on the total mass of formaldehyde and aminosilane coupling agent as 100%, the mass of the catalyst is 0.5-2%, for example, but not limited to 0.5%, 0.7%, 1.0%, 1.3%, 1.5%, 1.8%, or 2%.

[0061] In some embodiments, the salicylate is phenyl salicylate and / or homosalate.

[0062] In some embodiments, the solvent is an alcohol solvent. For example, the solvent includes methanol and ethanol. There is no particular limitation on the amount of solvent added. Preferably, the mass of the solvent is 5-50% of the total mass of formaldehyde and aminosilane coupling agent. More preferably, the mass of the solvent is 30-50% of the total mass of formaldehyde and aminosilane coupling agent.

[0063] Specifically, the reflux reaction time is 4-12 hours, for example, but not limited to 4 hours, 6 hours, 8 hours, 10 hours, or 12 hours.

[0064] Specifically, the post-processing steps are as follows:

[0065] After removing the solvent by rotary evaporation of the reaction product, a saturated sodium carbonate aqueous solution was added and stirred for 30-60 min. Then, dichloromethane was added for extraction. The extracted product was washed with saturated brine until neutral. The washed product was dried with anhydrous sodium sulfate, filtered, and the solvent was removed by rotary evaporation again to obtain the adhesion promoter.

[0066] Thirdly, the application of the adhesive accelerator in moisture-curing silicone resins is provided.

[0067] Fourthly, a moisture-curing silicone resin is provided, comprising the following components in parts by weight: 100 parts of polydimethylsiloxane, 1-10 parts of crosslinking agent, 5-100 parts of filler, 1-30 parts of plasticizer, 0.01-5 parts of catalyst, and 0.1-5 parts of the adhesion promoter.

[0068] In different embodiments, the weight parts of the crosslinking agent may be, but are not limited to, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, or 10 parts.

[0069] In different embodiments, the plasticizer may be present in, but is not limited to, 1 part, 3 parts, 8 parts, 10 parts, 14 parts, 17 parts, 20 parts, 25 parts, 27 parts, or 30 parts by weight.

[0070] In different embodiments, the weight parts of the filler may be, but are not limited to, 5 parts, 10 parts, 20 parts, 30 parts, 40 parts, 50 parts, 60 parts, 70 parts, 80 parts, 90 parts, or 100 parts.

[0071] In different embodiments, the catalyst may be, but is not limited to, 0.01 parts, 0.1 parts, 0.5 parts, 1 part, 1.5 parts, 2 parts, 3 parts, 4 parts, 4.5 parts, or 5 parts by weight.

[0072] In different embodiments, the weight parts of the adhesion promoter may be, but are not limited to, 0.1 parts, 0.5 parts, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, or 5 parts.

[0073] In this disclosure, if the content of the adhesion accelerator is too low, it will not play its role as an adhesion accelerator, and the weather resistance, adhesion, and water-resistant adhesion of the resulting moisture-curing silicone resin will decrease; if the amount of adhesion accelerator is too high, the enhancement of the weather resistance, adhesion, and water-resistant adhesion of the resulting moisture-curing silicone resin will not be obvious, resulting in a waste of resources.

[0074] In some embodiments, the polydimethylsiloxane is at least one of α,ω-dihydroxypolydimethylsiloxane and methyldimethoxy-terminated polydimethylsiloxane;

[0075] In some embodiments, the viscosity of the polydimethylsiloxane at 25°C is 1000-150000 mPa•s, for example, but not limited to 1000 mPa•s, 3000 mPa•s, 7000 mPa•s, 10000 mPa•s, 30000 mPa•s, 50000 mPa•s, 80000 mPa•s, 100000 mPa•s, 120000 mPa•s, and 150000 mPa•s.

[0076] In some embodiments, the crosslinking agent is at least one of ketoxime silane and alkoxysilane.

[0077] Specifically, the ketooxime silane is at least one of methyltributanone oxime silane, vinyltributanone oxime silane, and tetrabutanone oxime silane.

[0078] Specifically, the alkoxysilane is at least one of methyltrimethoxysilane, vinyltrimethoxysilane, propyltrimethoxysilane, methyl orthosilicate, and ethyl orthosilicate.

[0079] In some embodiments, the filler is at least one selected from calcium carbonate, diatomaceous earth, quartz sand, and silica.

[0080] In some embodiments, the plasticizer is at least one of mineral oil and dimethyl silicone oil;

[0081] In some embodiments, the catalyst is at least one of organotin catalysts and organotitanium catalysts.

[0082] Specifically, the organotin catalyst is at least one of dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, stannous octoate, and dibutyltin diacetylacetonate;

[0083] Specifically, the organotitanium catalyst is at least one of tetrabutyl titanate, tetratert-butyl titanate, titanium diisopropoxydiacetylacetonate, and titanium diisopropoxydiacetylacetonate.

[0084] In some embodiments, the moisture-curing silicone resin further includes 0.01-5 parts by weight of a silane coupling agent, wherein the silane coupling agent is at least one selected from γ-epoxypropoxypropyltrimethoxysilane, γ-epoxypropoxypropyltriethoxysilane, 2-(3,4-epoxycyclohexane)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexane)ethyltriethoxysilane, γ-(epoxypropoxy)propylmethyltrimethoxysilane, and γ-(epoxypropoxy)propylmethyltriethoxysilane.

[0085] Fifthly, the application of the aforementioned moisture-curing silicone resin in sealants is provided.

[0086] To further illustrate the present invention, the following detailed description, in conjunction with embodiments, of the adhesive accelerator for moisture-curing silicone resin provided by the present invention, its preparation method, and its application, should not be construed as limiting the scope of protection of the present invention.

[0087] Example 1

[0088] This embodiment provides an adhesion promoter, the structural formula of which is:

[0089] It is marked as ZJ-1.

[0090] The preparation method of the adhesion promoter in this embodiment includes the following steps:

[0091] In a four-necked flask equipped with a thermometer, dropping funnel, mechanical stirrer, and condenser, 11.3 g of 37% formaldehyde aqueous solution, 17.9 g of aminopropyltrimethoxysilane, and 50 g of ethanol were added sequentially. Stirring was started, and 0.5 g of hydrochloric acid was added. The mixture was stirred at room temperature for 30 min. Then, 21.4 g of phenyl salicylate was added, and the mixture was refluxed for 5 h. After removing the solvent by rotary evaporation, 20 mL of saturated sodium bicarbonate aqueous solution was added, and the mixture was stirred for 30 min. Extracted with 50 mL of dichloromethane, then washed with saturated brine until neutral, dried over anhydrous sodium sulfate, filtered, and the solvent removed by rotary evaporation to obtain the adhesive promoter. The 1H NMR spectrum of the obtained adhesive promoter is as follows: 0.57 (2H), 1.5 (2H), 2.5 (2H), 3.55 (9H), 3.8 (2H), 6.85 (1H), 7.14-7.16 (4H), 7.33 (2H), 7.78 (1H).

[0092] Example 2

[0093] This embodiment provides an adhesion promoter, the structural formula of which is:

[0094] It is marked as ZJ-2.

[0095] The preparation method of the adhesion promoter in this embodiment includes the following steps:

[0096] In a four-necked flask equipped with a thermometer, dropping funnel, mechanical stirrer, and condenser, 12.1 g of 37% formaldehyde aqueous solution, 17.9 g of aminopropyltrimethoxysilane, and 50 g of ethanol were added sequentially. Stirring was started, and 0.5 g of hydrochloric acid was added. The mixture was stirred at room temperature for 30 min. Then, 25.0 g of 2-ethylhexyl salicylate was added, and the mixture was refluxed for 8 h. After removing the solvent by rotary evaporation, 20 mL of saturated sodium bicarbonate aqueous solution was added, and the mixture was stirred for 30 min. Extraction was then performed with 50 mL of dichloromethane, followed by saturated sodium bicarbonate solution. Wash with brine until neutral, dry with anhydrous sodium sulfate, filter, and remove solvent by rotary evaporation to obtain the adhesion promoter. The 1H NMR spectrum data of the obtained adhesion promoter are as follows: 0.56 (2H), 1.05-1.22 (18H), 1.32 (2H), 1.5 (2H), 1.6 (1H), 1.78-1.82 (4H), 2.5 (2H), 3.8-3.85 (8H), 3.9 (1H), 6.8 (1H), 7.10 (1H), 7.6 (1H).

[0097] Example 3

[0098] This embodiment provides an adhesion promoter, the structural formula of which is:

[0099] It is marked as ZJ-3.

[0100] The preparation method of the adhesion promoter in this embodiment includes the following steps:

[0101] In a four-necked flask equipped with a thermometer, dropping funnel, mechanical stirrer, and condenser, 12.1 g of 37% formaldehyde aqueous solution, 17.9 g of aminopropyltrimethoxysilane, and 50 g of ethanol were added sequentially. Stirring was started, and 0.5 g of hydrochloric acid was added. The mixture was stirred at room temperature for 30 min. Then, 25.0 g of 2-ethylhexyl salicylate was added, and the mixture was refluxed for 8 h. After removing the solvent by rotary evaporation, 20 mL of saturated sodium bicarbonate aqueous solution was added, and the mixture was stirred for 30 min. The product was extracted with 50 mL of dichloromethane, washed with saturated brine until neutral, dried over anhydrous sodium sulfate, filtered, and the solvent was removed by rotary evaporation to obtain the adhesion promoter. The 1H NMR spectrum of the obtained adhesion promoter is as follows: 0.58 (2H), 0.96 (6H), 1.25-1.33 (9H), 1.5 (2H), 2.55-2.67 (6H), 3.55 (9H), 3.8 (2H). 4.2 (2H), 6.8 (1H), 7.1(1H), 7.6 (1H).

[0102] Example 4

[0103] This embodiment provides an adhesion promoter, the structural formula of which is:

[0104] It is marked as ZJ-4.

[0105] The preparation method of the adhesion promoter in this embodiment includes the following steps:

[0106] In a four-necked flask equipped with a thermometer, dropping funnel, mechanical stirrer, and condenser, 16.2 g of 37% formaldehyde aqueous solution, 22.2 g of aminoethylaminopropyltrimethoxysilane, and 60 g of ethanol were added sequentially. Stirring was started, and 0.5 g of hydrochloric acid was added. The mixture was stirred at room temperature for 30 min. Then, 50 g of 2-ethylhexyl salicylate was added, and the mixture was refluxed for 8 h. After removing the solvent by rotary evaporation, 20 mL of saturated sodium bicarbonate aqueous solution was added, and the mixture was stirred for 30 min. Extraction was then performed with 100 mL of dichloromethane, followed by extraction with saturated sodium bicarbonate solution. The adhesive was washed with brine until neutral, dried with anhydrous sodium sulfate, filtered, and the solvent was removed by rotary evaporation to obtain the adhesive accelerator. The 1H NMR spectrum data of the obtained adhesive accelerator are as follows: 0.56 (2H), 0.95 (12H), 1.25-1.33 (16H), 1.45 (2H), 2.0 (2H), 2.36-2.65 (6H), 3.5 (9H), 3.6 (2H), 3.8 (2H), 4.2 (4H), 6.8 (2H), 7.1 (2H), 7.6 (2H).

[0107] Example 5

[0108] This embodiment provides a moisture-curing silicone resin composition, the preparation method of which is as follows:

[0109] 60 parts by weight of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 50 Pa•s at 25°C, 3.0 parts by weight of methyl tributanone oxime silane, 1.0 part by weight of vinyl tributanone oxime silane, 35 parts by weight of stearic acid-treated calcium carbonate, 5 parts by weight of dimethyl silicone oil with a viscosity of 350 mPa•s at 25°C, 0.02 parts by weight of dibutyltin dilaurate, 1.2 parts by weight of adhesion promoter ZJ-1, and 0.32 parts by weight of glycidyl etheroxypropyltrimethoxysilane were degassed and mixed in a universal mixer to obtain a moisture-curing silicone resin composition.

[0110] Example 6

[0111] This embodiment provides a moisture-curing silicone resin composition, which differs from Example 5 only in that adhesive accelerator ZJ-1 is replaced with adhesive accelerator ZJ-2, while the other components and amounts remain unchanged.

[0112] Example 7

[0113] This embodiment provides a moisture-curing silicone resin composition, which differs from Example 5 only in that adhesive accelerator ZJ-1 is replaced with adhesive accelerator ZJ-3, while the other components and their amounts remain unchanged.

[0114] Example 8

[0115] This embodiment provides a moisture-curing silicone resin composition, which differs from Example 5 only in that adhesive accelerator ZJ-1 is replaced with adhesive accelerator ZJ-4, while the other components and their amounts remain unchanged.

[0116] Example 9

[0117] This embodiment provides a moisture-curing silicone resin composition, which differs from Example 5 only in that the weight of the adhesion promoter ZJ-1 is 0.06 parts, while the other components and their amounts remain unchanged.

[0118] Example 10

[0119] This embodiment provides a moisture-curing silicone resin composition, which differs from Example 5 only in that the weight of the adhesion promoter ZJ-1 is 2.1 parts, while the other components and their amounts remain unchanged.

[0120] Example 11

[0121] This embodiment provides a moisture-curing silicone resin composition, which differs from Example 5 only in that the adhesive accelerator ZJ-1 is 3 parts by weight, while the other components and their amounts remain unchanged.

[0122] Example 12

[0123] This embodiment provides a moisture-curing silicone resin composition, which differs from Example 5 only in that the adhesive accelerator ZJ-1 is 4 parts by weight, while the other components and their amounts remain unchanged.

[0124] Example 13

[0125] This embodiment provides a moisture-curing silicone resin composition, which differs from Example 5 only in that the weight of glycidoxypropyltrimethoxysilane is 0 parts, while the other components and their amounts remain unchanged. That is, glycidoxypropyltrimethoxysilane is not added in this embodiment.

[0126] Example 14

[0127] This embodiment provides a moisture-curing silicone resin composition, the preparation method of which is as follows:

[0128] 60 parts by weight of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 50 Pa•s at 25°C, 0.4 parts by weight of methyl tributanone oxime silane, 0.2 parts by weight of vinyl tributanone oxime silane, 60 parts by weight of diatomaceous earth, 0.6 parts by weight of dimethyl silicone oil with a viscosity of 350 mPa•s at 25°C, 3 parts by weight of dibutyltin dilaurate, 1.2 parts by weight of adhesion promoter ZJ-1, and 3 parts by weight of glycidyl etheroxypropyltrimethoxysilane were degassed and mixed in a universal mixer to obtain a moisture-curing silicone resin composition.

[0129] Example 15

[0130] This embodiment provides a moisture-curing silicone resin composition, the preparation method of which is as follows:

[0131] 60 parts by weight of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 50 Pa•s at 25°C, 4.5 parts by weight of methyl tributanone oxime silane, 1.5 parts by weight of vinyl tributanone oxime silane, 3 parts by weight of stearic acid-treated calcium carbonate, 30 parts by weight of dimethyl silicone oil with a viscosity of 350 mPa•s at 25°C, 1 part by weight of dibutyltin dilaurate, 1.2 parts by weight of adhesion promoter ZJ-1, and 3 parts by weight of glycidyl etheroxypropyltrimethoxysilane were degassed and mixed in a universal mixer to obtain a moisture-curing silicone resin composition.

[0132] Comparative Example 1

[0133] This comparative example provides a moisture-curing silicone resin composition, which differs from Example 5 only in that γ-aminopropyltriethoxysilane is used to replace the adhesion promoter ZJ-1, while the other components and their amounts remain unchanged.

[0134] Comparative Example 2

[0135] This comparative example provides a moisture-curing silicone resin composition, which differs from Example 5 only in that the weight of the adhesion accelerator ZJ-1 is 0 parts, while the other components and their amounts remain unchanged, i.e., no adhesion accelerator is added in this comparative example.

[0136] Performance testing

[0137] The moisture-curing silicone resin compositions obtained in the examples and comparative examples were used to prepare H-type adhesive test specimens (using Al-PBT substrate) according to the method provided in Chapter 7 of GB / T13477.8-2002. The specimens were then cured for 7 days at a temperature of (23±2)℃ and a relative humidity of (50±5)%. The H-type adhesive test specimens were then subjected to the following tests, and the test conditions and results are shown in Table 1.

[0138] Table 1

[0139]

[0140] Note: Bond strength retention rate refers to the ratio of the bond strength after immersion in water at 45℃ and exposure to ultraviolet light for 168 hours to the bond strength after being placed under standard conditions at 23℃ for 7 days.

[0141] As shown in Table 1, the adhesive strength of the moisture-curing silicone resin prepared using the adhesive accelerator of this disclosure is greater than 1.0 MPa after being placed under standard conditions for 7 days, soaked in water at 23℃ for 28 days, and soaked in water at 45℃ + irradiated with ultraviolet light for 168 hours. The adhesive strength retention rate is greater than 85%, and the area of ​​adhesive failure is less than 10%. This indicates that the adhesive accelerator of this disclosure can effectively improve the adhesion of moisture-curing silicone resin to PBT substrate and improve the weather resistance and water resistance of moisture-curing silicone resin.

[0142] Comparing Examples 5, 9-12 and Comparative Example 2, it can be seen that the weight of the adhesion accelerator affects the performance of the moisture-curing silicone resin. When the weight of the adhesion accelerator is 1.2-3 parts, the resulting moisture-curing silicone resin has better weather resistance and water-resistant adhesion.

[0143] Comparing Examples 5, 13, and 1, it can be seen that Comparative Example 1, which uses a primary amine silane coupling agent, showed that after soaking in water at 23°C for 28 days and in water at 45°C for 168 hours under ultraviolet light, the adhesive failure area of ​​the moisture-curing silicone resin was 100%, indicating complete debonding. This demonstrates that compared with the primary amine silane coupling agent, the adhesive accelerator disclosed herein can effectively improve the weather resistance and water-resistant adhesiveness of the moisture-curing silicone resin.

[0144] Finally, it should be noted that the above embodiments are used to illustrate the technical solutions of this disclosure and not to limit the scope of protection of this disclosure. Although this disclosure has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this disclosure without departing from the substance and scope of the technical solutions of this disclosure.

Claims

1. An adhesion promoter for moisture-curing silicone resins, characterized in that, The adhesion promoter is selected from at least one of the compounds with the structure shown in Formula I: ； Among them, R 1 It is hydrogen; R 2 R 3 Each is independently methyl or ethyl; R 4 It is one of hydrogen, hydroxyl, or C1-C20 alkyl; R 5 It is one of the C1-C20 alkyl groups; X is 1,6-ethyleneaminopropyl; a is 0 or 1.

2. An adhesion promoter for moisture-curing silicone resins, characterized in that, The adhesion promoter is selected from at least one of the following compounds: ； ； ； 。 3. A method for preparing a moisture-curing silicone resin adhesive accelerator as described in claim 1 or 2, characterized in that, Includes the following steps: Formaldehyde and aminosilane coupling agent are dissolved in a solvent, then a catalyst is added and stirred until homogeneous. Next, salicylic acid ester is added, and the mixture is refluxed to obtain the reaction product. The reaction product is then post-treated to obtain the adhesion promoter. The molar ratio of salicylic acid ester:formaldehyde:aminosilane coupling agent is 1-3:1-3:

1.

4. The method for preparing a moisture-curing silicone resin adhesion accelerator as described in claim 3, characterized in that, The aminosilane coupling agent is aminoethylaminopropyltrimethoxysilane; And / or, the catalyst is an acid, wherein the acid is at least one selected from hydrochloric acid, sulfuric acid, and trifluoroacetic acid; And / or, the salicylate is homosalate; And / or, the solvent is an alcohol solvent.

5. The application of the adhesion promoter for moisture-curing silicone resin as described in claim 1 or 2 in moisture-curing silicone resin.

6. A moisture-curing silicone resin, characterized in that, It comprises the following components in parts by weight: 100 parts of polydimethylsiloxane, 1-10 parts of crosslinking agent, 5-100 parts of filler, 1-30 parts of plasticizer, 0.01-5 parts of catalyst, and 0.1-5 parts of adhesive accelerator as described in claim 1 or 2.

7. The moisture-curing silicone resin as described in claim 6, characterized in that, The polydimethylsiloxane is at least one of α,ω-dihydroxy polydimethylsiloxane and methyldimethoxy-terminated polydimethylsiloxane; And / or, the viscosity of the polydimethylsiloxane at 25°C is 1000-150000 mPa•s; And / or, the crosslinking agent is at least one of ketoxime silane and alkoxy silane; And / or, the filler is at least one of calcium carbonate, diatomaceous earth, quartz sand, and silica; And / or, the plasticizer is at least one of mineral oil and dimethyl silicone oil; And / or, the catalyst is at least one of organotin catalysts and organotitanium catalysts.

8. The moisture-curing silicone resin as described in claim 7, characterized in that, The ketooxime silane is at least one of methyltributanone oxime silane, vinyltributanone oxime silane, and tetrabutanone oxime silane; And / or, the alkoxysilane is at least one of methyltrimethoxysilane, vinyltrimethoxysilane, propyltrimethoxysilane, methyl orthosilicate, and ethyl orthosilicate; And / or, the organotin catalyst is at least one of dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, stannous octoate, and dibutyltin diacetylacetonate; And / or, the organotitanium catalyst is at least one of tetrabutyl titanate, tetratert-butyl titanate, titanium diisopropoxydiacetylacetonate, and titanium diisopropoxydiacetylacetonate.

9. The moisture-curing silicone resin as described in claim 6, characterized in that, The moisture-curing silicone resin further includes 0.01-5 parts by weight of a silane coupling agent, wherein the silane coupling agent is at least one selected from γ-epoxypropoxypropyltrimethoxysilane, γ-epoxypropoxypropyltriethoxysilane, 2-(3,4-epoxycyclohexane)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexane)ethyltriethoxysilane, γ-(epoxypropoxy)propylmethyltrimethoxysilane, and γ-(epoxypropoxy)propylmethyltriethoxysilane.

10. The use of the moisture-curing silicone resin as described in any one of claims 6-9 in sealants.

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