CN113881391A

CN113881391A - Dealcoholized high-performance silicone structural sealant and preparation method thereof

Info

Publication number: CN113881391A
Application number: CN202111112874.2A
Authority: CN
Inventors: 缪潘; 周炳根; 郭焕珍; 高杰
Original assignee: Guangzhou Constant Silicone Co ltd
Current assignee: Guangzhou Constant Silicone Co ltd
Priority date: 2021-09-23
Filing date: 2021-09-23
Publication date: 2022-01-04

Abstract

The invention discloses a dealcoholized high-performance silicone structural sealant which comprises the following components:

Description

Dealcoholized high-performance silicone structural sealant and preparation method thereof

Technical Field

The invention relates to the field of organosilicon bonding sealing materials, in particular to a single-component dealcoholized silicone structural sealant meeting European standard ETAG 002.

Background

The dealcoholized silicone structure sealant is an organosilicon adhesive with wide application, and can be used for building bonding sealing, industrial bonding sealing and aviation bonding sealing. The composition of the catalyst mainly comprises alpha, omega-dihydroxy polydimethylsiloxane (107 glue), a filler, a cross-linking agent, a coupling agent and a catalyst, wherein the commonly used catalyst is titanate. Because the product is neutral as a whole, the product can meet the rigorous requirement of structural bonding of buildings with very high requirement on durability. The product releases micromolecular alcohols in the curing process, does not cause serious pollution to the environment and meets the requirement of environmental protection. Meanwhile, with the development of the technology, silicone structural adhesive products meet the national standard GB 16776-. However, ETAG002 also specifies that the design strength of the structural sealant is 1/6 which is the standard value, i.e., the standard value should be greater than 0.84MPa if the design strength is 0.14MPa according to the current national specifications. In addition, the detection conditions of the ETAG002 are more than the national standard, and include the conditions of detergent soaking, salt spray, acid mist, mechanical fatigue, tear resistance and the like, and also include shear strength and high and low temperature shear strength. Whether the strength detection result is qualified under the conditions is evaluated, and the strength is measured by the retention rate of the strength instead of requiring the strength to be larger than a certain value like the American standard and the national standard. If the strength is decreased by more than 25%, the strength is considered to be decreased too rapidly to satisfy the durability requirement of the structure. Therefore, under the harsh test requirements, only a few manufacturers with strong technical strength in China have related products to market, and the products of foreign manufacturers have high technical barriers and high cost. The invention provides a single-component dealcoholized silicone structural sealant meeting European standard ETAG002 and a preparation method thereof.

Disclosure of Invention

The invention aims to provide a one-component curing dealcoholized silicone sealant which meets the European standard ETAG002

Technical scheme

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

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

5-20 parts of dimethyl silicone oil

50-90 parts of reinforcing filler

4-8 parts of No. 1 cross-linking agent

10-15 parts of No. 2 crosslinking agent

4-8 parts of No. 3 cross-linking agent

2-5 parts of catalyst

1-3 parts of coupling agent

The viscosity of the 107 glue ranges from 50000-100000 cps;

the viscosity range of the dimethyl silicone oil is 100-1500 cps;

the reinforcing filler is hydrophobic nano calcium carbonate;

the No. 1 cross-linking agent is one or two of dimethoxy dimethyl silane, dimethoxy methyl vinyl silane, diethoxy dimethyl silane and diethoxy methyl vinyl silane;

the No. 2 cross-linking agent is one or two of methyltrimethoxysilane, propyl trimethoxysilane and hexadecyl trimethoxysilane;

the No. 3 cross-linking agent is one or two of tetramethoxysilane, tetraethoxysilane and tetraisopropoxysilane;

the catalyst is one or two of diacetone diisopropoxytitanium, ethyl diacetylacetate diisopropoxytitanium and the like;

the coupling agent is a reactant of KH-550 and KH-560 according to a molar ratio of 1:1 at 80 ℃ and normal pressure, and is numbered as a first coupling agent. KH-540 and KH-560 are reactants with a molar ratio of 1:1 at 80 ℃ and normal pressure, and are numbered as one or two of coupling agents;

the preparation method comprises the following steps: putting 107 glue, dimethyl silicone oil and filler into a kneader, heating at the temperature of 120 ℃ and 150 ℃, keeping the vacuum degree between-0.08 and-0.1 MPa, dehydrating for 90 to 180min to obtain the required base material, sealing and cooling for later use. And putting the base stock 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 required high-performance silicone structural sealant.

Key mechanical property test reference standard: ETAG002

The data show that the sealant with the single-component dealcoholized silicone structure completely meets the performance requirements of European standard ETAG002, and is a high-performance product.

The invention has the beneficial effects that: by selecting the No. 1 crosslinking agent with bifunctionality, the crosslinking density of the sealant at the later curing stage is controlled, and the sealant is ensured to have lasting good elasticity. The number 2 crosslinking agent with three functionality is selected to form an obvious elastomer with a three-dimensional structure after the sealant is cured, so that the sealant is ensured to have good mechanical property. The four-functionality No. 3 cross-linking agent is needed to form a local high cross-linking density area on the colloid, so that the sealant has a strength retention rate of over 75 percent under various conditions (particularly high temperature) and good bonding performance after long-term soaking in water. Meanwhile, KH550 and KH560 are subjected to an open-loop reaction of amino groups and epoxy groups according to an equal molar ratio, primary amino groups are converted into secondary amino groups, the degradation effect of primary amine groups immersed in water on a Si-O-Si structure is weakened, and the long-term soaking water resistance of the sealant is further improved, so that the type and the proportion are prepared, and the single-component dealcoholized silicone sealant meeting the European standard ETAG002 can be prepared by selecting proper material types and scientific proportions.

Claims

1. The single-component dealcoholized silicone structural sealant meeting the European standard ETAG002 comprises the following components in parts by mass:

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

5-20 parts of dimethyl silicone oil

50-90 parts of reinforcing filler

4-8 parts of No. 1 cross-linking agent

10-15 parts of No. 2 crosslinking agent

4-8 parts of No. 3 cross-linking agent

2-5 parts of catalyst

1-3 parts of a coupling agent.

2. The 107 glue of claim 1, having a viscosity in the range of 50000-100000 cps.

3. The dimethicone of claim 1 having a viscosity in the range of 100-1500 cps.

4. The reinforcing filler according to claim 1, being a hydrophobic nano calcium carbonate.

5. The crosslinking agent No. 1 according to claim 1, which is one or two of dimethoxydimethylsilane, dimethoxymethylvinylsilane, diethoxymethyldimethylsilane and diethoxymethylvinylsilane.

6. The No. 2 crosslinking agent of claim 1, which is one or two of methyltrimethoxysilane, propyltrimethoxysilane and hexadecyltrimethoxysilane.

7. The No. 3 crosslinking agent according to claim 1, which is one or two of tetramethoxysilane, tetraethoxysilane and tetraisopropoxysilane.

8. The catalyst according to claim 1, which is one or two of diisopropoxytitanium diacetone, diisopropoxytitanium ethylacetoacetate and the like.

9. The coupling agent according to claim 1, which is a reaction product of KH-550 and KH-560 at a molar ratio of 1:1 at 80 ℃ under normal pressure, numbered as coupling agent (i). KH-540 and KH-560 are reactants with a molar ratio of 1:1 at 80 ℃ and normal pressure, and are numbered as one or two of coupling agents.

10. The preparation method according to claim 1 is as follows: putting 107 glue, dimethyl silicone oil and filler into a kneader, heating at the temperature of 120 ℃ and 150 ℃, keeping the vacuum degree between-0.08 and-0.1 MPa, dehydrating for 90 to 180min to obtain the required base material, sealing and cooling for later use. And putting the base stock 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 required high-performance silicone structural sealant.