Oxime type cross-linking agent, deoximation type organosilicon sealant and preparation method of deoximation type organosilicon sealant

Abstract

The invention discloses an oxime type cross-linking agent, a deoximation type organosilicon sealant and a preparation method thereof, and the oxime type cross-linking agent is prepared by taking phenyltrimethylsilane and chlorine as raw materials to react to obtain a product 1, and then taking the product 1 and 5-methyl-3-heptanone oxime as raw materials to react to obtain the product 1, and the mass ratio of the product 1 to 5-methyl-3-heptanone oxime is 1: 1.4-1.5. The deoximation type organosilicon sealant comprises the following components: alpha, omega-dihydroxy polydimethylsiloxane, a modified filler, an oxime type cross-linking agent, a coupling agent and a catalyst. The deoximation type organosilicon sealant is high in curing efficiency, the 3-hour curing depth reaches 1.5-2.0 mm, the strength retention rate after damp-heat aging is remarkably improved, meanwhile, 5-methyl-3-heptanone oxime is released through curing, and the carcinogenic risk level of the sealant is reduced by two levels compared with that of diacetylmonoxime.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of high polymer materials, and specifically belongs to the technical field of adhesives. Specifically, the present application relates to an oxime type crosslinking agent, an organic silicon sealant based on the oxime type crosslinking agent and a preparation method thereof. BACKGROUND

[0002] The de-oxime type organic silicon sealant is widely used in the fields of building and new energy due to neutral curing and non-corrosiveness, but the traditional de-oxime type organic silicon sealant still has two technical bottlenecks:

[0003] ①Slow deep curing: the sealant relies on moisture penetration for crosslinking, and the 24h curing depth is only 2-4mm, which will seriously affect the actual production efficiency in the fields of building and new energy;

[0004] ②Fast mechanical property decay: the crosslinking network of the sealant is hydrolyzed under a humid heat environment, resulting in a strength decrease of more than 30%.

[0005] In addition, the crosslinking agent commonly used in the traditional de-oxime type organic silicon sealant is methyl tributyl ketoxime silane, and the butanone oxime released by the methyl tributyl ketoxime silane is suspected to be a carcinogen. SUMMARY

[0006] Therefore, the purpose of the present application is to provide a de-oxime type organic silicon sealant with fast deep curing, high mechanical strength, long-term weather resistance and environmental protection.

[0007] The technical scheme for achieving the above-mentioned purpose of the present application comprises the following.

[0008] In a first aspect of the present application, an oxime type crosslinking agent is provided, which is obtained by reacting phenyltrimethylsilane and chlorine gas as raw materials in a mass ratio of 1.8-2.2:1 to obtain product 1, and then reacting product 1 and 5-methyl-3-heptanone oxime as raw materials; the mass ratio of product 1 and 5-methyl-3-heptanone oxime is 1:1.4-1.5.

[0009] In a second aspect of the present application, a preparation method of the above-mentioned oxime type crosslinking agent is provided, which comprises the following steps:

[0010] (1) mixing β-cyclodextrin and phenyltrimethylsilane in a solvent, adding chlorine gas, and performing ultraviolet irradiation reaction to obtain product 1;

[0011] (2) mixing product 1 obtained in step (1) and 5-methyl-3-heptanone oxime, injecting triethylamine for reaction, then injecting hexamethyldisilazane, introducing supercritical carbon dioxide, and extracting to obtain the oxime type crosslinking agent.

[0012] In a third aspect of the present application, the above-mentioned oxime type crosslinking agent is applied in the preparation of a de-oxime type organic silicon sealant.

[0013] In a fourth aspect of the present application, a deoxime type silicone sealant is provided, comprising the following components by weight:

[0014]

[0015] In a fifth aspect of the present application, a preparation method of the above-mentioned deoxime type silicone sealant is provided, comprising the following steps:

[0016] (1) Dehydrate the α, ω-dihydroxypolydimethylsiloxane and the modified filler in a kneader to obtain a base;

[0017] (2) Cool the base obtained in step (1) to below 60℃, add a crosslinking agent, a coupling agent and a catalyst, and stir to obtain the product.

[0018] In the present application, a new type of deoxime type silicone sealant is prepared by using a new type of oxime type crosslinking agent synthesized by the technology of β-cyclodextrin ultraviolet template chlorination combined with microreactor oximation, which is mainly composed of 5-methyl-3-heptanone oxime silane and has 10-15 mol% of phenyl groups substituted in the alkyl side chain. The deoxime type silicone sealant prepared by using the new type of oxime type crosslinking agent as a crosslinking agent has high curing efficiency, a 3h curing depth of 1.5-2.0mm, and a significantly improved strength retention rate (≥90%) after hygrothermal aging, and at the same time, releases 5-methyl-3-heptanone oxime, which has a 2-level reduction in the carcinogenic risk grade compared with butanone oxime, and is more environmentally friendly. DETAILED DESCRIPTION

[0019] In order to facilitate the understanding of the present application, the present application will be described more fully below. The present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0020] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing the specific embodiments and are not used to limit the present application. The term "and / or" used in the present application includes any and all combinations of one or more related listed items.

[0021] The experimental methods in the following examples not otherwise specified are generally carried out according to the conventional conditions, or according to the conditions recommended by the manufacturers. The various common chemical reagents used in the examples are all commercially available products.

[0022] In some embodiments of the present application, an oxime type crosslinking agent is disclosed, which is obtained by reacting phenyltrimethylsilane and chlorine gas as raw materials in a mass ratio of 1.8-2.2:1 to obtain product 1, and then reacting product 1 and 5-methyl-3-heptanone oxime as raw materials; the mass ratio of product 1 and 5-methyl-3-heptanone oxime is 1:1.4-1.5.

[0023] In one embodiment, the mass ratio of phenyltrimethylsilane and chlorine gas is 1.9-2.1:1.

[0024] In one embodiment, the mass ratio of product 1 and 5-methyl-3-heptanone oxime is 1:1.45-1.49.

[0025] In one embodiment, the molar percentage of phenyl in the oxime type crosslinking agent is 10%-15%.

[0026] In one embodiment, the molar percentage of phenyl in the oxime type crosslinking agent is 11%-13%.

[0027] In some other embodiments of the present application, a preparation method of the above-mentioned oxime type crosslinking agent is disclosed, comprising the following steps:

[0028] (1) mixing β-cyclodextrin and phenyltrimethylsilane in a solvent, then adding chlorine gas and performing ultraviolet irradiation reaction to obtain product 1;

[0029] (2) mixing product 1 obtained in step (1) and 5-methyl-3-heptanone oxime, then injecting triethylamine to perform reaction, further injecting hexamethyldisilazane, introducing supercritical carbon dioxide, and extracting to obtain the oxime type crosslinking agent.

[0030] By means of the new technology of β-cyclodextrin ultraviolet template chlorination combined with microreactor oximation, a novel oxime type crosslinking agent is synthesized, which is based on 5-methyl-3-heptanone oxime group silane as the main frame, and 10-15 mol% of phenyl is substituted in the alkyl side chain of 5-methyl-3-heptanone oxime group silane. The silicone sealant prepared by using the novel oxime type crosslinking agent has the following advantages: on the one hand, due to the synergistic effect of the electronic effect of phenyl and the oxime ester structure, the crosslinking rate is significantly improved, and the deep curing ability is strengthened, the 3h curing depth reaches 1.5-2.0 mm, which is more than 50% higher than that of the traditional oxime type silicone sealant (0.8-1.2 mm); on the other hand, the hydrolytic degradation of the silicone sealant is inhibited by using the steric hindrance effect of phenyl, and the silicone sealant has long-term weather resistance, the strength retention rate is ≥90% after 1000h humid heat aging (85℃ / 85%RH), and there is no peeling at the sealing interface; and since 5-methyl-3-heptanone oxime is released during curing, the carcinogenic risk level is reduced by 2 levels compared with butanone oxime, and the silicone sealant has good environmental protection.

[0031] In one embodiment, the molar ratio of the β-cyclodextrin and phenyltrimethylsilane in step (1) is 1:1.8-2.2.

[0032] In one embodiment, the molar ratio of the β-cyclodextrin and phenyltrimethylsilane in step (1) is 1:1.9-2.1.

[0033] In one embodiment, the temperature of the acetonitrile in step (1) is 8-12°C.

[0034] In one embodiment, the temperature of the acetonitrile in step (1) is 9-11°C.

[0035] In one embodiment, the time of the ultraviolet irradiation reaction in step (1) is 1.5-2.5h.

[0036] In one embodiment, the mass ratio of the 5-methyl-3-heptanone oxime and triethylamine in step (2) is 1:0.6-0.8.

[0037] In one embodiment, the mass ratio of the 5-methyl-3-heptanone oxime and triethylamine in step (2) is 1:0.6-0.7.

[0038] In one embodiment, the mass ratio of the 5-methyl-3-heptanone oxime and hexamethyldisilazane in step (2) is 1:0.4-0.6.

[0039] In one embodiment, the mass ratio of the 5-methyl-3-heptanone oxime and hexamethyldisilazane in step (2) is 1:0.5-0.6.

[0040] In one embodiment, the mixing time in step (2) is 25-35s.

[0041] In one embodiment, the temperature of the reaction in step (2) is 55-65°C, and the reaction time is 4-6min.

[0042] In other embodiments of the present application, the use of the oxime-type crosslinking agent described above in the preparation of a deoxime-type silicone sealant is disclosed.

[0043] In other embodiments of the present application, a deoxime-type silicone sealant is disclosed, comprising the following components by weight:

[0044]

[0045] In one embodiment, the deoxime-type silicone sealant comprises the following components by weight:

[0046]

[0047]

[0048] In one embodiment, the viscosity of the α,ω-dihydroxypolydimethylsiloxane is 50,000 mPa·s to 100,000 mPa·s.

[0049] In one embodiment, the viscosity of the α,ω-dihydroxypolydimethylsiloxane is 50,000 mPa·s to 80,000 mPa·s.

[0050] In one embodiment, the modified filler is a surface-modified porous silica with a pore size of 10 nm to 60 nm or a nano-active calcium carbonate with a specific surface area of 20 m 2 / g to 40 m 2 / g.

[0051] In one embodiment, the modified filler is a hexamethyldisilazane-modified 3A molecular sieve with a pore size of 45 nm to 55 nm.

[0052] In one embodiment, the nano-active calcium carbonate has a specific surface area of 25 m 2 / g to 35 m 2 / g.

[0053] In one embodiment, the coupling agent is γ-glycidyloxypropyltrimethoxysilane and γ-aminopropyltriethoxysilane in a mass ratio of 2:1.

[0054] In one embodiment, the catalyst is dibutyltin dilaurate.

[0055] In other embodiments of the present application, a preparation method of the above-mentioned deoxime-type silicone sealant is disclosed, comprising the following steps:

[0056] (1) Dehydrate the α,ω-dihydroxypolydimethylsiloxane and the modified filler in a kneader to obtain a base material;

[0057] (2) Cool the base material of step (1) to below 60°C, add a crosslinking agent, a coupling agent, and a catalyst, and stir to obtain the product.

[0058] In one embodiment, step (1) is dehydrated at 118°C to 122°C and -0.094 MPa to -0.096 MPa for 1.5 h to 2.5 h.

[0059] In one embodiment, step (2) is stirred at 48°C to 52°C and -0.094 MPa to -0.096 MPa for 60 to 90 min.

[0060] The various raw materials used in the examples are commercially available.

[0061] The application will be described in detail below with reference to specific examples.

[0062] Example 1 Synthesis of phenyl-substituted 5-methyl-3-heptanone oxime silane

[0063] The synthesis steps are as follows:

[0064] (1) Selective phenylation reaction

[0065] 1 mol of β-cyclodextrin (β-CD) is mixed with 2 mol of phenyltrimethylsilane (C6H5Si(CH3)3, p-Tolyltrimethylsilane) in acetonitrile solvent at 10°C to form an inclusion complex (i.e. a β-CD molecular template), and then chlorine gas (Cl2) is added (the mass ratio of phenyltrimethylsilane to chlorine gas is 2:1), and ultraviolet light (UV, 254 nm) is irradiated for 2 h, and the product 1 is obtained after purification;

[0066] (2) Continuous oximation in a three-stage microreactor

[0067] In the first premixing zone, 410 g of product 1 is mixed with 602.7 g of 5-methyl-3-heptanone oxime (mass ratio 1:1.47) for 30 s;

[0068] Into the second reaction zone, triethylamine (405 g) is injected, and the reaction is carried out at 60°C for 5 min to complete the oxime esterification;

[0069] Into the third quenching zone, hexamethyldisilazane (323 g) is injected to remove residual chloride ions and to block the surface silanol groups, and supercritical carbon dioxide is introduced to extract the triethylamine hydrochloride salt.

[0070] Finally, colorless and transparent product, phenyl-substituted 5-methyl-3-heptanone oxime silane, is obtained, with a molar percentage of phenyl groups of 12% and a chloride ion content of less than 5 ppm.

[0071] Example 2 Deoxime-type silicone sealant

[0072] The raw materials for the deoxime-type silicone sealant of this example are as follows (by weight):

[0073]

[0074]

[0075] Among them, the oxime-type crosslinking agent is the phenyl-substituted 5-methyl-3-heptanone oxime silane synthesized in Example 1.

[0076] The preparation method of the deoxime-type silicone sealant of this example includes the following steps:

[0077] (1) 107 gum (α,ω-dihydroxypolydimethylsiloxane) was dehydrated with hexamethyldisilazane modified 3A molecular sieve in a kneader at 120°C, -0.095 MPa for 2h to obtain a base material;

[0078] (2) The base material was cooled to below 60°C, and was put into a planetary mixer, and a crosslinking agent, phenyl-substituted 5-methyl-3-heptanone oximylsilane, a composite coupling agent, and an organic tin catalyst were added, and stirring was carried out at 50°C, -0.095 MPa for 70 min to obtain the product.

[0079] Example 3: Deoxime-type silicone sealant

[0080] The raw materials of the deoxime-type silicone sealant of this example were as follows (parts by weight):

[0081]

[0082] The oxime-type crosslinking agent was the phenyl-substituted 5-methyl-3-heptanone oximylsilane synthesized in Example 1.

[0083] The preparation method of the deoxime-type silicone sealant of this example was the same as that of Example 2.

[0084] Comparative Example 1: Deoxime-type silicone sealant

[0085] The raw materials of the deoxime-type silicone sealant of this example were as follows (parts by weight):

[0086]

[0087] The preparation method of the deoxime-type silicone sealant of this example was the same as that of Example 2.

[0088] Comparative Example 2: Deoxime-type silicone sealant

[0089] The raw materials of the deoxime-type silicone sealant of this example were as follows (parts by weight):

[0090]

[0091] The preparation method of the deoxime-type silicone sealant of this example was the same as that of Example 2.

[0092] Comparative Example 3: Deoxime-type silicone sealant

[0093] The raw materials of the deoxime-type silicone sealant of this example were as follows (parts by weight):

[0094]

[0095] The preparation method of the deoxime-type silicone sealant of this example was the same as that of Example 2.

[0096] The curing depth (according to GB / T 13477), mechanical strength, weather resistance and butanone oxime release amount of the deoxime type silicone sealant of examples 2-3 and comparative examples 1-3 were tested according to the national standard method, and the results are shown in Table 1.

[0097] Table 1

[0098] Project Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 3h Curing Depth / mm 1.8 1.5 1.0 0.8 0.9 7 Day Tensile Strength / Mpa 3.7 3.0 3.0 2.6 3.0 Tensile Strength After DH1000 Aging / Mpa 3.4 2.7 2.0 1.6 2.0 Butanone Oxime Release ug / g Not Detected Not Detected 340 350 Not Detected

[0099] The results in Table 1 show that the silicone sealants of examples 2 and 3 have significantly better 3h curing depth than the silicone sealants of comparative examples 1-3 due to the use of the new oxime type crosslinking agent phenyl-substituted 5-methyl-3-heptanone oxime silane. The wet heat strength retention rate of the silicone sealants of examples 2 and 3 is all ≥90%, while the wet heat strength retention rate of the silicone sealants of comparative examples 1-3 is all <70%. In addition, no butanone oxime is detected in the silicone sealants of examples 2 and 3.

[0100] The above results show that the silicone sealant of the present application can accelerate moisture penetration, significantly improve curing efficiency, significantly strengthen deep curing ability, and inhibit hydrolysis, so that the strength retention rate after wet heat aging is very high. At the same time, the silicone sealant of the present application has environmental protection.

[0101] The technical features of the above-described examples can be combined in any manner. In order to make the description concise, all possible combinations of the technical features in the above-described examples are not described, however, as long as the combinations of the technical features do not contradict each other, they should be considered as within the scope of the present disclosure.

[0102] The above-described examples only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as limiting the scope of the patent. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of protection of the present patent should be subject to the appended claims.

Claims

1. An oxime-type crosslinking agent, characterized in that, It is obtained by reacting phenyltrimethylsilane and chlorine in a mass ratio of 1.8 to 2.2:1 to produce product 1, and then reacting product 1 and 5-methyl-3-heptanone oxime in a mass ratio of 1:1.4 to 1.5 to produce product 1.

2. The oxime crosslinking agent according to claim 1, characterized in that, The mass ratio of phenyltrimethylsilane to chlorine is 1.9 to 2.1:1, and the mass ratio of product 1 to 5-methyl-3-heptanone oxime is 1:1.45 to 1.

49.

3. The oxime-type crosslinking agent according to claim 1, characterized in that, The molar percentage of phenyl groups is 10% to 15%, preferably 11% to 13%.

4. The method for preparing the oxime crosslinking agent according to any one of claims 1 to 3, characterized in that, Includes the following steps: (1) After mixing β-cyclodextrin and phenyltrimethylsilane in a solvent, chlorine gas was added and the mixture was subjected to ultraviolet light irradiation to obtain product 1. (2) After mixing the product 1 described in step (1) with 5-methyl-3-heptanone oxime, triethylamine was injected to react; then hexamethyldisilazane was injected, supercritical carbon dioxide was introduced, and extraction was performed to obtain the product.

5. The method for preparing the oxime-type crosslinking agent according to claim 4, characterized in that, The molar ratio of β-cyclodextrin and phenyltrimethylsilane in step (1) is 1:1.8 to 2.2, preferably 1:1.9 to 2.1; And / or, the ultraviolet irradiation reaction time in step (1) is 1.5h to 2.5h; And / or, the solvent in step (1) is acetonitrile, and the temperature of the acetonitrile is 8°C to 12°C, preferably 9°C to 11°C; And / or, in step (2), the mass ratio of 5-methyl-3-heptanone oxime to triethylamine is 1:0.6 to 0.8, preferably 1:0.6 to 0.7; the mass ratio of 5-methyl-3-heptanone oxime to hexamethyldisilazane is 1:0.4 to 0.6, preferably 1:0.5 to 0.6; And / or, the mixing time in step (2) is 25s to 35s; the reaction temperature is 55℃ to 65℃, and the reaction time is 4min to 6min.

6. The use of the oxime crosslinking agent according to any one of claims 1 to 5 in the preparation of deoxime-type silicone sealant.

7. A deoxime-type silicone sealant, characterized in that, The components include the following parts by weight: Preferably, it comprises the following components in parts by weight:

8. The deoxime-type silicone sealant according to claim 7, characterized in that, The modified filler is surface-modified porous silica with a pore size of 10 nm to 60 nm or a specific surface area of ​​20 m². 2 / g~40m 2 / g of nano-activated calcium carbonate, preferably hexamethyldisilazane-modified 3A molecular sieve with a pore size of 45nm-55nm or a specific surface area of ​​25m². 2 / g~35m 2 / g of nano-active calcium carbonate; And / or, the coupling agent is γ-glycidoxypropyltrimethoxysilane and γ-aminopropyltriethoxysilane in a mass ratio of 1.8 to 2.2:1; And / or, the catalyst is dibutyltin dilaurate; And / or, the viscosity of the α,ω-dihydroxypolydimethylsiloxane is 50,000 mPa·s to 100,000 mPa·s, preferably 50,000 mPa·s to 80,000 mPa·s.

9. A method for preparing the oxime-type silicone sealant according to claim 7 or 8, characterized in that, Includes the following steps: (1) α,ω-dihydroxypolydimethylsiloxane and modified filler were dehydrated in a kneader to obtain a base material; (2) Cool the base material described in step (1) to below 60°C, add crosslinking agent, coupling agent and catalyst, and stir to obtain the product.

10. The method for preparing the deoxime-type silicone sealant according to claim 9, characterized in that, In step (1), the water is dehydrated at 118℃~122℃ and -0.094MPa~-0.096MPa for 1.5h~2.5h; And / or, in step (2), stir at 48℃~52℃ and -0.094MPa~-0.096MPa for 60~90min.

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