阅读说明：本技术 一种防霉硅酮密封胶及制备方法 (Mildew-proof silicone sealant and preparation method thereof ) 是由 陈炳耀 彭小琴 李世晶 于 2020-03-19 设计创作，主要内容包括：本发明公开了一种防霉硅酮密封胶及制备方法,其特征在于主要成分为二羟基聚硅氧烷、含环氧基团有机硅改性树脂、改性粉煤灰、增白剂、防霉剂、交联剂、偶联剂、催化剂。本发明的优点是：1.应用发电厂排出的废料粉煤灰,因经高温碳化而具有持久不长霉菌的优势,并将粉煤灰用纯度≥99%的AI2O3球块和纯度≥99%SiO2方块进行研磨,并用气流筛分筛出5μm以下的粉料,再经旋转式永磁除铁器去除粉内的铁离子,再用γ-氨丙基三乙氧基硅烷和十八烷酸进行改性,使改性粉煤灰具有白度高,不生霉菌,补强效果好等；2.应用含环氧基团有机硅树脂,改善硅橡胶表面疏松结构,使固化后胶模表面具真瓷感,防止霉菌浸入。3.制备产品具有成本低、防霉效果持久及力学性能优。(The invention discloses a mildew-proof silicone sealant and a preparation method thereof, and is characterized in that the sealant mainly comprises dihydroxy polysiloxane, organic silicon modified resin containing epoxy groups, modified fly ash, a whitening agent, a mildew-proof agent, a cross-linking agent, a coupling agent and a catalyst. The invention has the advantages that: 1. the waste fly ash discharged by a power plant has the advantage of lasting mildew resistance due to high-temperature carbonization, is ground by using AI2O3 spherical blocks with the purity of more than or equal to 99% and SiO2 square blocks with the purity of more than or equal to 99%, powder with the purity of less than 5 mu m is screened out by using air flow screening, iron ions in the powder are removed by using a rotary permanent magnet iron remover, and the powder is modified by using gamma-aminopropyltriethoxysilane and octadecanoic acid, so that the modified fly ash has the advantages of high whiteness, no mildew, good reinforcing effect and the like; 2. the organic silicon resin containing epoxy groups is applied to improve the loose structure of the surface of the silicon rubber, so that the surface of the cured rubber mold has a real porcelain feeling and prevents mould from immersing. 3. The prepared product has low cost, lasting mildew-proof effect and excellent mechanical property.)

1. The mildew-proof silicone sealant and the preparation method thereof are characterized in that the mildew-proof silicone sealant comprises the following components in parts by weight:

26-35 parts of dihydroxy polysiloxane

20-25 parts of acrylic acid modified silicone resin

35-40 parts of modified fly ash

1-3 parts of whitening agent

0.5-1 part of mildew preventive

4.0-5.5 parts of silane crosslinking agent

0.4-0.7 part of silane coupling agent

0.06-0.15 parts of catalyst.

2. The mold resistant silicone sealant of claim 1 wherein said dihydroxy polysiloxane is a dihydroxy polysiloxane

At least one of a viscosity of 20000mPas and 80000mPas at 25 ℃; the epoxy group-containing organosilicon tree

A lipid characterized by a side chain containing an epoxy group, the structural formula being as follows, wherein: r is methyl or phenyl, Vi is methyl,

m is an integer ranging from 1 to 35; n is an integer in the range of 1-35; k is an integer in the range of 1-20.

3. The mold-resistant silicone sealant according to claim 1, wherein said modified fly ash is used first and has a purity

Grinding AI2O3 balls with the purity of more than or equal to 99 percent and SiO2 squares with the purity of more than or equal to 99 percent, and screening out 5 mu m by airflow screening

The fly ash is then passed through a rotary permanent-magnet iron remover to remove iron ions in the fly ash, and 0.1-0.2% of gamma-ion

Performing modification treatment on aminopropyltriethoxysilane and 0.2-0.5% octadecanoic acid, and controlling the granularity of the fly ash to be less than or equal to

5 mu m, the whiteness is more than or equal to 88 percent, and the iron ion content is less than or equal to 0.01 percent.

4. The sealant according to claim 1, wherein the whitening agent is anatase titanium dioxide having an oil absorption of 22 to 28; the mildew preventive is tetramethyl thiuram disulfide: 2, 2' -dithiobis (N-methylbenzamide) =0.2 to 0.3: 0.2 to 0.5; the silane cross-linking agent is at least one of methyl tributyl ketoxime silane, vinyl tributyl ketoxime silane, propyl tributyl ketoxime silane and tetrabutoxime silane; at least one of the silane coupling agents N- (beta-aminoethyl) -gamma-aminopropyl trimethyl (ethyl) oxysilane (KH-792), gamma-aminopropyl triethoxysilane (KH-550) and gamma-glycidoxypropyl trimethoxysilane (KH-560); the catalyst is a dibutyltin dilaurate compound, and the content of effective substances is as follows: not less than 80%, crystallization point: < 20 ℃.

Background

With the continuous development of social economy, the pursuit of people on the quality of life is continuously improved, and the pursuit is also improved for buildings

The requirements for details of objects, interior decoration and the like are higher and higher, the mechanical property of the product is required to be good, and the higher requirements on the aspects of appearance, environmental protection and the like are also increased. The silicone mildew-proof adhesive plays an increasingly important role in decoration aspects due to excellent weather resistance, water resistance, high displacement strength, low cost and the like, for example, joints between cooking benches and walls, joints between toilet tables and walls, joints between bathtubs and walls, joints between toilets and the ground, joints between laboratory sinks and walls and the like need to be bonded and sealed by using sealant, and the joints are relatively humid throughout the year, so that the appearance is influenced, and harmful bacteria threaten the health of human beings if contacting with human bodies or food, and the joints are easy to be damaged by bacteria, mildew and color change due to loose structures on the surfaces of the silicone sealant. As in application publication No.: the chinese patent CN103773308 mainly uses an efficient and environment-friendly organic bactericide and mildew preventive and a zinc-loaded zeolite inorganic antibacterial and antifungal agent with a porous structure, which are ground to compound the antibacterial and mildew preventive, so as to achieve a long-acting mildew-proof effect, and although a certain mildew-proof effect is achieved, the loose structure and the easy-to-break surface of the silicone adhesive surface are changed, and the surface is damaged by bacteria, mildew and other microorganisms, so that a very durable mildew-proof effect cannot be achieved. Application publication No.: the CN105086907.A adopts a system completely different from a silicone structural adhesive, overcomes the defect of poor mildew-proof effect of the traditional mildew-proof silicone sealant, has brightness similar to a ceramic glaze surface after the product is cured, and greatly improves the mildew-proof effect, but the invention is an epoxy resin formula system, does not belong to the application field range of silicone adhesives, and has the defects of wall damage or degumming caused by insufficient displacement force at a joint due to overlarge epoxy resin hardness (more than 90A), high cost of the epoxy resin formula system, inconvenient two-component construction and the like, and is rarely used in the market. According to application CN101298550A, an environment-friendly nano-silver particle efficient mildew preventive and an anion paint additive medium are added in a formula, and the environment-friendly nano-silver particle efficient mildew preventive and the anion paint additive medium used in the invention have the defects of high cost, incapability of resisting mildew for a long time and the like.

Therefore, it is necessary to develop a silicone sealant with low cost, high efficiency and lasting mildew resistance, expand the market application field, fully utilize renewable resources, change waste into valuable and improve the environment.

Disclosure of Invention

The invention aims to overcome the defects of the background technology, and provides the mildew-proof silicone sealant which has the characteristics of low cost, environmental protection, lasting mildew-proof effect, excellent weather resistance and bonding force, no influence on displacement capacity and the like through the selection and modification treatment of materials.

The mildew-proof silicone sealant and the preparation method thereof are characterized in that the mildew-proof silicone sealant comprises the following components in parts by weight:

26-35 parts of dihydroxy polysiloxane

20-25 parts of acrylic acid modified silicone resin

35-40 parts of modified fly ash

1-3 parts of whitening agent

0.5-1 part of mildew preventive

4.0-5.5 parts of silane crosslinking agent

0.4-0.7 part of silane coupling agent

0.06-0.15 parts of catalyst.

The viscosity of the dihydroxy polysiloxane is at least one of 20000mPas and 80000mPas at 25 ℃; the organic silicon resin containing epoxy groups is characterized in that the side chain contains epoxy groups, and the structural formula is as follows, wherein: r is methyl or phenyl, Vi is methyl, and m is an integer ranging from 1 to 35; n is an integer in the range of 1-35; k is an integer in the range of 1-20.

The modified fly ash is ground by using AI2O3 balls with the purity of more than or equal to 99% and SiO2 squares with the purity of more than or equal to 99%, fly ash with the particle size of less than 5 mu m is screened out by using airflow screening, iron ions in the fly ash are removed by using a rotary permanent magnet de-ironing separator, and the modified fly ash is modified by using 0.1-0.2% of gamma-aminopropyltriethoxysilane and 0.2-0.5% of octadecanoic acid, wherein the particle size of the fly ash is controlled to be less than or equal to 5 mu m, the whiteness is controlled to be more than or equal to 88%, and the content of the iron ions is controlled to be less than or equal to 0.01%.

The whitening agent is anatase titanium dioxide, and the oil absorption is 22-28; the mildew preventive is tetramethyl thiuram disulfide: 2, 2' -dithiobis (N-methylbenzamide) =0.2 to 0.3: 0.2 to 0.5; the silane cross-linking agent is at least one of methyl tributyl ketoxime silane, vinyl tributyl ketoxime silane, propyl tributyl ketoxime silane and tetrabutoxime silane; at least one of the silane coupling agents N- (beta-aminoethyl) -gamma-aminopropyl trimethyl (ethyloxy) silane (KH-792), gamma-aminopropyl triethoxysilane (KH-550) and gamma-glycidoxypropyl trimethoxysilane (KH-560); the catalyst is a high-activity dibutyltin dilaurate compound, and the content of effective substances is as follows: not less than 80%, crystallization point: < 20 ℃.

Compared with the prior art, the mildew-proof silicone sealant has the following beneficial effects: should be taken

The fly ash which is a solid waste discharged by a power plant has the advantages of lasting mildew resistance due to high-temperature carbonization treatment, is used after being ground and modified, has low cost and lasting mildew-proof effect, is matched with an organic silicon modified resin containing an epoxy group to improve the loose structure of the surface of silicon rubber, ensures that the surface of a cured product has a real porcelain feeling, and is matched with a high-efficiency mildew inhibitor for compounding, so that the prepared product has the characteristics of low cost, lasting mildew-proof effect, moderate displacement capacity and excellent bonding force, the performance meets the relevant requirements of standard JC/T885, and is mildew-proof grade 0, and no mildew grows on the surface after culturing mildew for 68 hours.

Detailed Description

The present invention is illustrated by the following examples, but the present invention is not limited to these examples. Modifications to the embodiments of the invention or equivalent substitutions of parts of technical features without departing from the spirit of the invention are intended to be covered by the scope of the claims of the invention.

Example 1

(a) Modifying and treating the fly ash: firstly, grinding modified fly ash by using AI2O3 balls with the purity of more than or equal to 99% and SiO2 squares with the purity of more than or equal to 99%, screening out fly ash with air flow screening, removing iron ions in the fly ash by using a rotary permanent magnet iron remover, and carrying out modification treatment by using 0.1-0.2% of gamma-aminopropyltriethoxysilane and 0.2-0.5% of octadecanoic acid, wherein the particle size is controlled to be less than or equal to 5 mu m, the whiteness is more than or equal to 88%, and the content of the iron ions is less than or equal to 0.01%.

(b) Preparing the mildew-proof silicone sealant: 26.74 parts of dihydroxy polysiloxane, 25 parts of acrylic acid modified silicone resin, 40 parts of modified fly ash and 3 parts of titanium dioxide, under the conditions that the temperature of feed liquid is 120-150 ℃, the vacuum degree is required to be-0.08 MPa-0.1 MPa, the dehydration is performed for 3-5 h, the temperature of the cooled material is lower than 50 ℃, then 0.3 part of tetramethyl thiuram disulfide, 0.2 part of 2, 2' -dithiobis (N-methyl benzamide), 3.5 parts of methyl tributyrinoxime silane and 0.5 part of vinyl tributyrinoxime silane are sequentially added, the mixture is stirred for 10-20 min at the rotating speed of 800 r/min-1500 r/min under the vacuum degree of-0.08 MPa, 0.3 part of KH-792 coupling agent, 0.4 part of KH-550 coupling agent and 0.06 part of dibutyltin dilaurate are added, the vacuum degree is controlled to be-0.08 MPa-0.1 MPa, the mixture is stirred for 20-30 min at the rotating speed of 800 r/min-1500 r/min, discharging, sealing and packaging.

Example 2

(a) Modifying and treating the fly ash: firstly, grinding modified fly ash by using AI2O3 balls with the purity of more than or equal to 99% and SiO2 squares with the purity of more than or equal to 99%, screening out fly ash with air flow screening, removing iron ions in the fly ash by using a rotary permanent magnet iron remover, and carrying out modification treatment by using 0.1-0.2% of gamma-aminopropyltriethoxysilane and 0.2-0.5% of octadecanoic acid, wherein the particle size is controlled to be less than or equal to 5 mu m, the whiteness is more than or equal to 88%, and the content of the iron ions is less than or equal to 0.01%.

(b) Preparing the mildew-proof silicone sealant: 29.84 parts of dihydroxy polysiloxane, 23 parts of acrylic acid modified silicone resin, 39 parts of modified fly ash and 2.3 parts of titanium dioxide, under the conditions that the temperature of feed liquid is 120-150 ℃, the vacuum degree is required to be-0.08 MPa-0.1 MPa, the dehydration is performed for 3-5 h, the temperature of the cooled material is lower than 50 ℃, 0.28 part of tetramethyl thiuram disulfide, 0.3 part of 2, 2' -dithiobis (N-methyl benzamide), 3.5 parts of methyl tributyrinoxime silane and 1.0 part of propyl tributyrinoxime silane are sequentially added, the mixture is stirred for 10-20 min at the rotating speed of 800 r/min-1500 r/min under the vacuum degree of-0.08 MPa, 0.4 part of KH-550 coupling agent, 0.3 part of KH-560 coupling agent and 0.08 part of dibutyltin dilaurate are added, the vacuum degree is controlled to be-0.08 MPa-0.1 MPa, the mixture is stirred for 20-30 min at the rotating speed of 800 r/min-1500 r/min, discharging, sealing and packaging.

Example 3

(a) Modifying and treating the fly ash: firstly, grinding modified fly ash by using AI2O3 balls with the purity of more than or equal to 99% and SiO2 squares with the purity of more than or equal to 99%, screening out fly ash with air flow, removing iron ions in the fly ash by using a rotary permanent magnet iron remover, and carrying out modification treatment by using 0.1-0.2% of gamma-aminopropyltriethoxysilane and 0.2-0.5% of octadecanoic acid, wherein the particle size is controlled to be less than or equal to 5 mu m, the whiteness is more than or equal to 88%, and the content of the iron ions is less than or equal to 0.01%;

(b) preparing the mildew-proof silicone sealant: 33.06 parts of dihydroxy polysiloxane, 22 parts of acrylic acid modified silicone resin, 37 parts of modified fly ash and 1.8 parts of titanium dioxide are sequentially added with 0.24 part of tetramethyl thiuram disulfide, 0.4 part of 2, 2' -dithiobis (N-methyl benzamide), 3.5 parts of methyl tributyrinoxime silane and 1.2 parts of tetrabutyl ketoxime silane under the conditions that the temperature of feed liquid is 120-150 ℃, the vacuum degree is required to be-0.08 MPa-0.1 MPa, the cooling material is lower than 50 ℃, the mixture is stirred for 10-20 min under the rotating speed of 800 r/min-1500 r/min, 0.3 part of KH-792 coupling agent, 0.4 part of KH-550 coupling agent and 0.1 part of dibutyltin dilaurate are added, the vacuum degree is controlled to be-0.08 MPa-0.1 MPa, the mixture is stirred for 20-30 min under the rotating speed of 800 r/min-1500 r/min, discharging, sealing and packaging.

Example 4

(a) Modifying and treating the fly ash: firstly, grinding modified fly ash by using AI2O3 balls with the purity of more than or equal to 99% and SiO2 squares with the purity of more than or equal to 99%, screening out fly ash with air flow, removing iron ions in the fly ash by using a rotary permanent magnet iron remover, and carrying out modification treatment by using 0.1-0.2% of gamma-aminopropyltriethoxysilane and 0.2-0.5% of octadecanoic acid, wherein the particle size is controlled to be less than or equal to 5 mu m, the whiteness is more than or equal to 88%, and the content of the iron ions is less than or equal to 0.01%;

(b) preparing the mildew-proof silicone sealant: 37.68 parts of dihydroxy polysiloxane, 20 parts of acrylic acid modified silicone resin, 35 parts of modified fly ash and 1 part of titanium dioxide are sequentially added under the conditions that the temperature of feed liquid is 120-150 ℃, the vacuum degree is required to be-0.08 MPa-0.1 MPa, the dehydration is 3-5 h, the temperature of a cooling material is lower than 50 ℃, 0.2 part of tetramethyl thiuram disulfide, 0.5 part of 2, 2' -dithiobis (N-methyl benzamide), 3.5 parts of methyl tributyrinoxime silane, 0.6 part of vinyl tributyrinoxime silane and 0.7 part of tetrabutynin oxime silane are sequentially added, the mixture is stirred for 10-20 min at the rotating speed of 800 r/min-1500 r/min under the vacuum degree of-0.08 MPa-0.1 MPa, 0.4 part of KH-550 coupling agent, 0.3 part of KH-560 coupling agent and 0.12 part of dibutyltin dilaurate are added, the vacuum degree is controlled to be-0.08 MPa-0.1 MPa, stirring for 20-30 min at the rotating speed of 800-1500 r/min, discharging, sealing and packaging.

Comparative example 5

Firstly 38 parts of dihydroxy polysiloxane, 54.94 parts of nano calcium carbonate and 1.2 parts of titanium dioxide, sequentially adding 0.28 part of tetramethyl thiuram disulfide, 0.3 part of 2, 2' -dithiobis (N-methyl benzamide), 3.5 parts of methyl tributyl ketoxime silane and 1.0 part of vinyl tributyrine ketoxime silane under the conditions that the temperature of feed liquid is 120-150 ℃, the vacuum degree is required to be-0.08 MPa-0.1 MPa, dehydrating for 3-5 h, and the temperature of a cooled material is lower than 50 ℃, stirring for 10-20 min at the rotating speed of 800 r/min-1500 r/min, adding 0.4 part of KH-550 coupling agent, 0.3 part of KH-792 coupling agent and 0.08 part of dibutyltin dilaurate, controlling the vacuum degree to be-0.08 MPa-0.1.1, stirring for 20-30 min at the rotating speed of 800 r/min-1500 r/min, discharging, sealing and packaging.

The mildew-proof silicone sealants of examples 1-4 and comparative example 5 were tested for their relevant performance by the following method:

the surface dry time is measured according to the GB/T13477.5-2002 test method for building sealing materials: the tensile modulus is measured according to the regulation of GB/T13477.8-2017 building sealing material test method; the elastic recovery rate is measured according to the regulation of GB/T13477.17-2017 building sealing material test method; the measurement of the definite elongation adhesion is carried out according to the regulation of GB/T13477.10-2017 test method for building sealing materials; the determination of the fixed-elongation caking property after soaking in water is carried out according to the regulation of GB/T13477.11-2017 test method for building sealing materials; the mildew-proof rating test method is carried out according to the regulation of GB1741 'determination method for mildew resistance of paint films'.

The product performance test results are shown in the following table;

note: the test conditions were: ambient room temperature 23 ℃ and humidity 55%.

As can be seen from the above table, a mildewproof silicone sealant of the present invention is compared with the prior art (comparative example 5): the mildew-proof grade performance of the product meets the relevant requirements of the standard JC/T885, the mildew is cultured for 28 days, and the highest grade of the mildew-proof grade 0 is achieved, but the embodiment of the invention has obvious advantages when the mildew is cultured for more than 38 days, while the prior art comparative example 5 has the growth of the mildew when the mildew is cultured for more than 38 days.