阅读说明：本技术 一种低模量硅酮耐候密封胶及其制备方法 (Low-modulus silicone weather-resistant sealant and preparation method thereof ) 是由 缪潘 周炳根 郭焕珍 高杰 于 2021-09-23 设计创作，主要内容包括：本发明公开了一种低模量硅酮耐候密封胶及其制备方法,其组成为：本发明选用具有特殊结构的化合物作为第一交联剂和第二交联剂,相互搭配调整交联密度和交联结构,可以制备出具有低模量性能的硅酮耐候密封胶,可以广泛用于高层幕墙接缝或者对位移级别要求很高的场所。(The invention discloses a low-modulus silicone weather-resistant sealant and a preparation method thereof, wherein the sealant comprises the following components:)

1. A low-modulus silicone weather-resistant sealant and a preparation method thereof are disclosed, wherein the sealant comprises the following components in parts by mass:

100 portions of alpha, omega-dihydroxy polydimethylsiloxane (107 glue)

20-40 parts of dimethyl silicone oil

40-80 parts of reinforcing filler

115-30 parts of cross-linking agent

210-20 parts of cross-linking agent

5-10 parts of coupling agent

0.1-1 part of catalyst.

2. The 107 glue of claim 1, having a viscosity in the range of 50000-150000 cps.

3. The dimethicone of claim 1 having a viscosity in the range of 100-1000 cps.

4. The reinforcing filler of claim 1, which is one or both of hydrophobic nano calcium carbonate and hydrophobic gas-phase SiO 2.

5. The crosslinking agent 1 according to claim 1, which is one or two of methyltributanoxime silane, vinyl tributyloximosilane, and 1, 6-bis (tributyloximosilyl) hexane.

6. The crosslinking agent 2 according to claim 1, which is one or both of 1, 6-bis (methyldiethanonoximosilyl) hexane and 1, 6-bis (vinyldibutanoneoximosilyl) hexane.

7. The coupling agent according to claim 1, which is one or two of KH-550, KH-540, KH-792, KH-560, and KH-570.

8. The catalyst according to claim 1, which is one or two of dibutyltin diacetate, dibutyltin dilaurate, dibutyltin diacetylacetonate, dibutyltin ethylacetoacetate and the like.

9. The preparation process according to claim 1 is as follows: putting 107 glue, reinforcing filler and dimethyl silicone oil into a kneader, heating at the temperature of 120 ℃ and 140 ℃, keeping the vacuum degree at-0.08 to-0.1 MPa, dehydrating for 90 to 180min to obtain the required base material, sealing and cooling for later use. And putting the base material into a planetary stirrer or a high-speed dispersion stirrer, adding the cross-linking agent, the coupling agent and the catalyst, and stirring and dispersing for a certain time under a certain vacuum degree to obtain the low-modulus silicone weather-resistant sealant.

Technical Field

The invention relates to the field of organosilicon joint filling sealing materials, in particular to a low-modulus silicone weather-resistant sealant and a preparation method thereof.

Background

The low-modulus silicone weather-resistant sealant is an organosilicon adhesive for sealing building joints, has good weather resistance, high and low temperature flexibility and wide adhesion, and is only used for sealing joints to play a role in waterproof sealing, so that the sealant is required to have good displacement capacity and adhesion force, and can adapt to the change of the width of the joints without adhesion. If the sealant has the characteristic of low modulus, the stress of the sealant, which causes compression and tension of the sealant in the width change process of the sealant seam, is small, and the tension on the bonding surface is small, so that the bonding stability can be effectively ensured. With the entrance of foreign products into the domestic market and the rationalization of the glue using concept, the trend of low modulus of the weather-resistant glue is more and more obvious, and low modulus products also receive wide attention and use.

The invention discloses a silicone sealant with low modulus, high elongation and good adhesion and a preparation method thereof in Chinese invention patent CN 201911360268.5. Chinese invention patent CN201810669200.4 discloses a single-component dealcoholized low-modulus silicone weather-resistant sealant and a preparation method thereof, and the technical route of the patent is that a chain extender comprises a first chain extender and a second chain extender, wherein the first chain extender is a silane oligomer, and the second chain extender is long-chain carbon silicone solid silane; in the preparation process, the addition sequence among the cross-linking agent, the first chain extender and the second chain extender is as follows in sequence: a first chain extender, a cross-linking agent and a second chain extender, thereby obtaining a product with low modulus, but has the problems of complex process and difficult secondary dispersion. The Chinese invention patent CN201711424247.6 discloses a dealcoholized silicone weather-resistant sealant with low modulus and high displacement capacity and a preparation method thereof, and a base polymer used in the sealant is 107 glue terminated by methyl dimethoxy, so that the sealant has no advantages in the aspects of cost and stability. By combining the existing products and technologies, the development of a low-modulus product with simple process, excellent mechanical properties, good adhesive properties and good storage stability is urgently needed.

Disclosure of Invention

The invention aims to provide the low-modulus organic silicon adhesive suitable for sealing the building joint, which has very good displacement capacity and bonding force, can adapt to the change of the width of the joint without being bonded, is used for sealing the joint, and plays a role in waterproof sealing.

Technical scheme

The invention achieves the required technical goal by adjusting the composition of the silicone weather-resistant sealant, and the silicone weather-resistant sealant comprises the following components in parts by mass:

100 portions of alpha, omega-dihydroxy polydimethylsiloxane (107 glue)

20-40 parts of dimethyl silicone oil

40-80 parts of reinforcing filler

115-30 parts of cross-linking agent

210-20 parts of cross-linking agent

5-10 parts of coupling agent

0.1 to 1 portion of catalyst

The viscosity range of the 107 glue is 50000-150000 cps;

the viscosity range of the simethicone is 100-1000 cps;

the reinforcing filler is one or two of hydrophobic nano calcium carbonate and hydrophobic gas-phase SiO 2;

the cross-linking agent 1 is one or two of methyl tributyl ketoxime silane, vinyl tributyl ketoxime silane and 1, 6-bis (tributyloximosilyl) hexane;

the cross-linking agent 2 is one or two of 1, 6-bis (methyl dibutylketoximino silicon) hexane and 1, 6-bis (vinyl dibutylketoximino silicon) hexane;

the coupling agent is one or two of KH-550, KH-540, KH-792, KH-560 and KH-570;

the catalyst is one or two of dibutyltin diacetate, dibutyltin dilaurate, dibutyltin diacetyl acetone, dibutyltin diacetyl ethyl acetate and the like;

the preparation method comprises the following steps: putting 107 glue, reinforcing filler and dimethyl silicone oil into a kneader, heating at the temperature of 120 ℃ and 140 ℃, keeping the vacuum degree at-0.08 to-0.1 MPa, dehydrating for 90 to 180min to obtain the required base material, sealing and cooling for later use. And putting the base material into a planetary stirrer or a high-speed dispersion stirrer, adding the cross-linking agent, the coupling agent and the catalyst, and stirring and dispersing for a certain time under a certain vacuum degree to obtain the low-modulus silicone weather-resistant sealant.

Detailed Description

In the following, some specific examples are given to facilitate a better understanding of the technical solutions of the present invention and the advantages obtained.

Example one

100 parts of 150000cps alpha, omega-dihydroxy polydimethylsiloxane, 40 parts of 100cps dimethyl silicone oil and 80 parts of hydrophobic nano calcium carbonate are put into a kneader, the temperature is 120 ℃, the vacuum degree is-0.08 MPa, the dehydration time is 180min, the required base material is obtained, and the base material is sealed and cooled for standby. Putting the base material into a planetary stirrer or a high-speed dispersion stirrer, adding 15 parts of methyl tributyl ketoxime silane, 10 parts of 1, 6-bis (methyl dibutyryl ketoxime silyl) hexane, 5 parts of KH-550 and 0.1 part of dibutyltin dilaurate, and stirring and dispersing for 40min under the vacuum degree of-0.1 MPa to obtain the low-modulus silicone weather-resistant sealant.

Example two

100 parts of 50000cps alpha, omega-dihydroxy polydimethylsiloxane, 20 parts of 100cps dimethyl silicone oil, 20 parts of hydrophobic nano calcium carbonate and 20 parts of hydrophobic gas phase SiO2 are put into a kneader, the temperature is 140 ℃, the vacuum degree is-0.08 MPa, the dehydration time is 180min, the required base material is obtained, and the base material is sealed and cooled for standby. Putting the base material into a planetary stirrer or a high-speed dispersion stirrer, adding 15 parts of methyl tributyl ketoxime silane, 15 parts of 1, 6-bis (tributanoximino-silicon-based) hexane, 20 parts of 1, 6-bis (methyl dibutanoximino-silicon-based) hexane, 10 parts of KH-792 and 1 part of dibutyltin dilaurate, and stirring and dispersing for 40min under the vacuum degree of-0.1 MPa to obtain the low-modulus silicone weather-resistant sealant.

EXAMPLE III

100 parts of 80000cps alpha, omega-dihydroxy polydimethylsiloxane, 30 parts of 1000cps dimethyl silicone oil and 50 parts of hydrophobic nano calcium carbonate are put into a kneader, the temperature is 120 ℃, the vacuum degree is-0.1 MPa, the dehydration time is 90min, the required base material is obtained, and the base material is sealed and cooled for standby. Putting the base material into a planetary stirrer or a high-speed dispersion stirrer, adding 10 parts of methyl tributyrinoxime silane, 5 parts of vinyl tributyrinoxime silane, 10 parts of 1, 6-bis (methyl dibutyloximino silicon-based) hexane, 2.5 parts of KH-550 and 0.1 part of dibutyltin dilaurate, and stirring and dispersing for 40min under the vacuum degree of-0.1 MPa to obtain the low-modulus silicone weather-resistant sealant.

Example four

100 parts of 100000cps alpha, omega-dihydroxy polydimethylsiloxane, 30 parts of 750cps dimethyl silicone oil and 70 parts of hydrophobic nano calcium carbonate are put into a kneader, the temperature is 130 ℃, the vacuum degree is-0.08 MPa, the dehydration time is 180min, the required base material is obtained, and the base material is sealed and cooled for standby. And putting the base material into a planetary stirrer or a high-speed dispersion stirrer, adding 20 parts of methyl tributyl ketoxime silane, 20 parts of 1, 6-bis (vinyl dibutyryl ketoximino silicon-based) hexane, 4 parts of KH-540 and 0.5 part of dibutyltin dilaurate, and stirring and dispersing for 40min under the vacuum degree of-0.1 MPa to obtain the low-modulus silicone weather-resistant sealant.

EXAMPLE five

100 parts of 80000cps alpha, omega-dihydroxy polydimethylsiloxane, 40 parts of 100cps dimethyl silicone oil and 80 parts of hydrophobic nano calcium carbonate are put into a kneader, the temperature is 120 ℃, the vacuum degree is-0.08 MPa, the dehydration time is 180min, the required base material is obtained, and the base material is sealed and cooled for standby. Putting the base material into a planetary stirrer or a high-speed dispersion stirrer, adding 15 parts of methyl tributyl ketoxime silane, 5 parts of vinyl tributyl ketoxime silane, 15 parts of 1, 6-bis (methyl dibutylketoxime silicon-based) hexane, 5 parts of KH-550, 0.1 part of dibutyltin dilaurate and 0.1 part of dibutyltin diacetylacetonate, and stirring and dispersing for 40min under the vacuum degree of-0.1 MPa to obtain the low-modulus silicone weather-resistant sealant.

Comparative example 1

100 parts of 100000cps alpha, omega-dihydroxy polydimethylsiloxane, 40 parts of 100cps dimethyl silicone oil and 80 parts of hydrophobic nano calcium carbonate are put into a kneader, the temperature is 120 ℃, the vacuum degree is-0.08 MPa, the dehydration time is 180min, the required base material is obtained, and the base material is sealed and cooled for standby. And putting the base material into a planetary stirrer or a high-speed dispersion stirrer, adding 20 parts of methyl tributyl ketoxime silane, 10 parts of vinyl tributyl ketoxime silane, 5 parts of KH-550 and 0.1 part of dibutyltin dilaurate, and stirring and dispersing for 40min under the vacuum degree of-0.1 MPa to obtain the low-modulus silicone weather-resistant sealant.

Comparative example No. two

100 parts of 100000cps alpha, omega-dihydroxy polydimethylsiloxane, 40 parts of 100cps dimethyl silicone oil and 80 parts of hydrophobic nano calcium carbonate are put into a kneader, the temperature is 120 ℃, the vacuum degree is-0.08 MPa, the dehydration time is 180min, the required base material is obtained, and the base material is sealed and cooled for standby. And putting the base material into a planetary stirrer or a high-speed dispersion stirrer, adding 20 parts of methyl tributyl ketoxime silane, 10 parts of vinyl tributyroxime silane, 10 parts of vinyl dibutyroxime silane, 5 parts of KH-550 and 0.1 part of dibutyltin dilaurate, and stirring and dispersing for 40min under the vacuum degree of-0.1 MPa to obtain the low-modulus silicone weather-resistant sealant.

Test and results

Mechanical property test reference standard: GB/T13477.

The data show that the low modulus performance of the low modulus silicone weather-resistant sealant provided by the invention completely meets the modulus requirement under the test condition specified in GB/T13477, and has good mechanical properties.

The invention has the beneficial effects that: the invention selects the compound with special structure as the first cross-linking agent and the second cross-linking agent, and mutually matches and adjusts the cross-linking density and the cross-linking structure, so that the silicone weather-resistant sealant with low modulus performance can be prepared, and can be widely used for high-rise curtain wall joints or places with high requirements on displacement level.