阅读说明：本技术 一种改性有机硅密封胶及其应用 (Modified organosilicon sealant and application thereof ) 是由 龙李华 柯明新 何亚宗 于 2021-09-27 设计创作，主要内容包括：本发明公开了一种改性有机硅密封胶及其制备方法与应用,属于密封材料技术领域。该密封胶包含以下重量份的组分：丙烯酸改性端硅烷氧基聚醚50～100份,增塑剂10～50份,触变剂2～10份,填料20～200份,除水剂0.5～3份,粘接力促进剂1～4份,催化剂0.1～0.5份。本发明的上述改性有机硅密封胶可作为触摸屏与边框壳体贴合的密封胶,取代传统的触摸屏贴合双面胶,具有较优的密封性、较高的初粘力,可提高贴合精度和生产效率,实现生产线的自动化和机械化。(The invention discloses a modified organosilicon sealant and a preparation method and application thereof, belonging to the technical field of sealing materials. The sealant comprises the following components in parts by weight: 50-100 parts of acrylic acid modified terminal siloxy polyether, 10-50 parts of plasticizer, 2-10 parts of thixotropic agent, 20-200 parts of filler, 0.5-3 parts of water removing agent, 1-4 parts of adhesion promoter and 0.1-0.5 part of catalyst. The modified organosilicon sealant can be used as a sealant for attaching a touch screen and a frame shell, replaces the traditional double-sided adhesive for attaching the touch screen, has excellent sealing property and high initial adhesion, can improve the attaching precision and the production efficiency, and realizes the automation and the mechanization of a production line.)

1. The modified organosilicon sealant is characterized by comprising the following components in parts by weight: 50-100 parts of acrylic acid modified terminal siloxy polyether, 10-50 parts of plasticizer, 2-10 parts of thixotropic agent, 20-200 parts of filler, 0.5-3 parts of water removing agent, 1-4 parts of adhesion promoter and 0.1-0.5 part of catalyst.

2. The modified silicone sealant of claim 1 wherein the acrylic modified silane-terminated polyether has a viscosity of 10000cPs to 100000 cPs.

3. The modified silicone sealant according to claim 1, wherein the plasticizer is at least one of aliphatic dibasic acid esters, phthalic acid esters, benzenepolycarboxylic acid esters, benzoic acid esters, polyol esters, chlorinated hydrocarbons, epoxies, citric acid esters, and polyesters.

4. The modified silicone sealant of claim 1 wherein the thixotropic agent is at least one of fumed silica, precipitated silica, montmorillonite clay, hydrogenated castor oil, polyamide wax and carbon black.

5. The modified silicone sealant according to claim 1, wherein the filler is at least one of nano calcium carbonate, light calcium carbonate, heavy calcium carbonate, silica micropowder, talc, mica powder, kaolin, alumina, magnesium oxide, zinc oxide, iron oxide, and titanium dioxide.

6. The modified silicone sealant of claim 1 wherein the water scavenger is a vinyl silane coupling agent.

7. The modified silicone sealant of claim 1 wherein the adhesion promoter is at least one of allylalkoxysilane, acryloxypropylalkoxysilane, aminohydrocarbylalkoxysilane, epoxyhydrocarbylalkoxysilane, mercaptohydrocarbylalkoxysilane.

8. The modified silicone sealant of claim 1 wherein the catalyst is an organotin catalyst, the organotin catalyst being one of dialkyltin dicarboxylates, dialkyldiaryloxytins, dialkyltin bis (β -ketoesters), and stannous dicarboxylates.

9. Use of an organically modified sealant according to any one of claims 1 to 8 for touch screen applications.

Technical Field

The invention relates to a modified organosilicon sealant and application thereof, belonging to the technical field of sealing materials.

Background

With the rapid development of the electronic communication industry technology, touch screens are more and more popular with consumers due to attractive appearance, convenience in operation, visualization and intellectualization. In the traditional manufacturing process of the touch screen, a double-sided adhesive tape is used for pressing and attaching to a frame shell of a mobile phone (or a flat panel and other equipment), the existing pressing and attaching production process needs manual film tearing of the double-sided adhesive tape, the double-sided adhesive tape is placed in a positioning groove consistent with the appearance of the mobile phone, then the touch screen and the frame shell are attached together, and pressing and fixing treatment is carried out.

The traditional touch screen laminating process has more manual demands, lower efficiency and larger manual operation error, is difficult to realize automation and mechanization, and needs to find a solution to effectively improve the production efficiency. The conventional organosilicon sealant contains higher content of low molecules (D3-D10), and is easy to cause pollution and failure by low molecule volatilization in the later period when applied to optical elements such as touch screens and the like. The common silane-terminated alkoxy polyether has low initial adhesion and low production efficiency.

Disclosure of Invention

The invention aims to overcome the defects of the prior art, provides the modified organic silicon sealant with good bonding performance, effectively replaces double-sided adhesive to firmly attach the touch screen and the frame shell, can realize automatic and mechanical dispensing and pressurization, and greatly improves the production efficiency.

In order to achieve the purpose, the invention adopts the technical scheme that: the modified organosilicon sealant comprises the following components in parts by weight: 50-100 parts of acrylic acid modified terminal siloxy polyether, 10-50 parts of plasticizer, 2-10 parts of thixotropic agent, 20-200 parts of filler, 0.5-3 parts of water removing agent, 1-4 parts of adhesion promoter and 0.1-0.5 part of catalyst.

According to the invention, the acrylic acid modified silane-terminated polyether is used as a base polymer, and a plasticizer, a thixotropic agent, a filler, a water removing agent, an adhesion promoter and a catalyst are added, so that the prepared modified organosilicon sealant has good mechanical property, high strength, large initial adhesion and good thixotropy, and is suitable for the attachment of a touch screen.

As a preferred embodiment of the modified organosilicon sealant, the viscosity of the acrylic modified silane-terminated polyether is 10000cPs-100000 cPs.

The viscosity of the acrylic acid modified silane-terminated polyether affects the bonding performance and tensile strength of the sealant, and if the viscosity is too low, the mechanical strength is poor, and if the viscosity is too high, the viscosity of the rubber material is high, and the production and processing difficulty is high. More preferably, the acrylic modified silane-terminated polyether has higher polarity, higher tensile strength and better adhesion performance compared with the common silane-terminated polyether.

In a preferred embodiment of the modified silicone sealant of the present invention, the plasticizer is at least one of aliphatic dibasic acid esters, phthalic acid esters, benzenepolycarboxylic acid esters, benzoic acid esters, polyol esters, chlorinated hydrocarbons, epoxies, citric acid esters, and polyesters.

The main function of the plasticizer is to weaken van der waals force between polymer molecules, thereby increasing mobility of polymer molecular chains and reducing crystallization of polymer molecular chains. The addition of the plasticizer into the sealant can increase the fluidity and reduce the hardness, but excessive plasticizer not only easily causes the migration and exudation of the plasticizer, but also influences the sagging property and the mechanical property of the sealant. The plasticizer adopted by the invention has high compatibility, high plasticizing efficiency and good adaptability.

As a preferred embodiment of the modified silicone sealant of the present invention, the thixotropic agent is at least one of fumed silica, precipitated silica, montmorillonite, hydrogenated castor oil, polyamide wax and carbon black.

Preferably, the thixotropic agent is fumed silica, the thixotropic efficiency of the fumed silica is high, and higher thixotropy can be achieved by adding a small amount of the fumed silica.

As a preferable embodiment of the modified silicone sealant of the invention, the filler is at least one of nano calcium carbonate, light calcium carbonate, heavy calcium carbonate, silicon micropowder, talcum powder, mica powder, kaolin, alumina, magnesium oxide, zinc oxide, ferric oxide and titanium dioxide.

Preferably, the filler is nano calcium carbonate, the nano calcium carbonate has an obvious reinforcing effect, and the colloid strength of the sealant can be effectively improved.

As a preferred embodiment of the modified organosilicon sealant, the water scavenger is a vinyl silane coupling agent.

Preferably, the water removing agent is vinyl trimethoxy silane, the water removing efficiency of the vinyl trimethoxy silane is high, and the storage life of the sealant can be effectively prolonged.

In a preferred embodiment of the modified silicone sealant of the present invention, the adhesion promoter is at least one of allylalkoxysilane, acryloxypropylalkoxysilane, aminohydrocarbylalkoxysilane, epoxyhydrocarbylalkoxysilane, mercaptohydrocarbylalkoxysilane.

Preferably, the adhesion promoter is N-beta- (aminoethyl) -gamma-aminopropyltrimethoxysilane or gamma-aminopropyltriethoxysilane, and the two adhesion promoters have excellent adhesion performance to various substrates.

As a preferred embodiment of the modified silicone sealant, the catalyst is an organotin catalyst, and the organotin catalyst is one of stannous octoate, dibutyltin diacetate and dioctyltin dilaurate.

Preferably, the organotin catalyst is dibutyltin dilaurate.

On the other hand, the invention provides application of the organic modified sealant in touch screen attachment.

Compared with the prior art, the invention has the beneficial effects that: the modified organosilicon sealant provided by the invention has excellent adhesion to touch screens and mobile phone shells, good sealing performance and good extrudability, is suitable for automatic and mechanized dispensing production processes, and can greatly improve the production efficiency of factories.

Detailed Description

To better illustrate the objects, aspects and advantages of the present invention, the present invention will be further described with reference to specific examples.

Example 1

The embodiment provides a modified organosilicon sealant for attaching a touch screen, which comprises the following components in parts by weight: 60 parts of acrylic acid modified terminal siloxy polyether, 40 parts of plasticizer, 10 parts of thixotropic agent, 150 parts of filler, 1 part of water removing agent, 1 part of adhesion promoter and 0.4 part of catalyst.

In this embodiment, the viscosity of the acrylic modified epoxy terminated polyether is 10000 cPs; the plasticizer is epoxidized soybean oil; the thixotropic agent is montmorillonite; the filler is light calcium carbonate; the water removing agent is vinyl triethoxysilane; the adhesion promoter is gamma- (2, 3-epoxypropoxy) propyl trimethoxy silane; the catalyst is stannous octoate.

Example 2

The embodiment provides a modified organosilicon sealant for attaching a touch screen, which comprises the following components in parts by weight: 60 parts of acrylic acid modified terminal siloxy polyether, 40 parts of plasticizer, 8 parts of thixotropic agent, 180 parts of filler, 2 parts of water removing agent, 2 parts of adhesion promoter and 0.4 part of catalyst.

In this embodiment, the viscosity of the acrylic modified terminal siloxy polyether is 20000 cPs; the plasticizer is tributyl citrate; the thixotropic agent is polyamide wax; the filler is silicon micropowder; the water removing agent is vinyl triethoxysilane; the adhesion promoter is gamma-methacryloxypropyltrimethoxysilane; the catalyst is dioctyltin dilaurate.

Example 3

The embodiment provides a modified organosilicon sealant for attaching a touch screen, which comprises the following components in parts by weight: 60 parts of acrylic acid modified terminal siloxy polyether, 40 parts of plasticizer, 8 parts of thixotropic agent, 180 parts of filler, 2 parts of water removing agent, 2 parts of adhesion promoter and 0.4 part of catalyst.

In this embodiment, the viscosity of the acrylic modified terminal siloxy polyether is 20000 cPs; the plasticizer is tributyl citrate; the thixotropic agent is polyamide wax; the filler is silicon micropowder; the water removing agent is vinyl triethoxysilane; the adhesion promoter is gamma-aminopropyl triethoxysilane; the catalyst is dioctyltin dilaurate.

Example 4

The embodiment provides a modified organosilicon sealant for attaching a touch screen, which comprises the following components in parts by weight: 60 parts of acrylic acid modified terminal siloxy polyether, 40 parts of plasticizer, 8 parts of thixotropic agent, 180 parts of filler, 2 parts of water removing agent, 2 parts of adhesion promoter and 0.4 part of catalyst.

In this embodiment, the viscosity of the acrylic modified terminal siloxy polyether is 20000 cPs; the plasticizer is tributyl citrate; the thixotropic agent is polyamide wax; the filler is silicon micropowder; the water removing agent is vinyl triethoxysilane; the adhesion promoter is N-beta- (aminoethyl) -gamma-aminopropyltrimethoxysilane; the catalyst is dioctyltin dilaurate.

Example 5

The embodiment provides a modified organosilicon sealant for attaching a touch screen, which comprises the following components in parts by weight: 80 parts of acrylic acid modified terminal siloxy polyether, 20 parts of plasticizer, 5 parts of thixotropic agent, 100 parts of filler, 1 part of water removing agent, 3 parts of adhesion promoter and 0.3 part of catalyst.

In this example, the viscosity of the acrylic modified epoxy terminated polyether was 40000 cPs; the plasticizer is dioctyl phthalate; the thixotropic agent is fumed silica, and the specific surface area is 200m 2/g; the filler is nano calcium carbonate; the water removing agent is vinyl trimethoxy silane; the adhesion promoter is N-beta- (aminoethyl) -gamma-aminopropyltrimethoxysilane; the catalyst was dibutyltin dilaurate.

Example 6

The embodiment provides a modified organosilicon sealant for attaching a touch screen, which comprises the following components in parts by weight: 100 parts of acrylic acid modified terminal siloxy polyether, 50 parts of plasticizer, 10 parts of thixotropic agent, 200 parts of filler, 3 parts of water removing agent, 4 parts of adhesion promoter and 0.5 part of catalyst.

In this example, the viscosity of the acrylic modified epoxy terminated polyether was 40000 cPs; the plasticizer is dioctyl phthalate; the thixotropic agent is fumed silica, and the specific surface area is 200m 2/g; the filler is nano calcium carbonate; the water removing agent is vinyl trimethoxy silane; the adhesion promoter is N-beta- (aminoethyl) -gamma-aminopropyltrimethoxysilane; the catalyst was dibutyltin dilaurate.

Example 7

The embodiment provides a modified organosilicon sealant for attaching a touch screen, which comprises the following components in parts by weight: 50 parts of acrylic acid modified terminal siloxy polyether, 10 parts of plasticizer, 2 parts of thixotropic agent, 20 parts of filler, 0.5 part of water removing agent, 2 parts of adhesion promoter and 0.1 part of catalyst.

In this example, the viscosity of the acrylic modified epoxy terminated polyether was 40000 cPs; the plasticizer is dioctyl phthalate; the thixotropic agent is fumed silica, and the specific surface area is 200m 2/g; the filler is nano calcium carbonate; the water removing agent is vinyl trimethoxy silane; the adhesion promoter is N-beta- (aminoethyl) -gamma-aminopropyltrimethoxysilane; the catalyst was dibutyltin dilaurate.

Comparative example 1

The only difference between this example and example 1 is that the terminal siloxy polyether used has not been acrylic modified.

Comparative example 2

The only difference between this comparative example and example 1 is that the acrylic modified siloxy terminated polyether has a viscosity of 3000 cPs.

Comparative example 3

The only difference between this comparative example and example 1 is that the plasticizer was dimethicone having a viscosity of 100 cPs.

Comparative example 4

The only difference between this comparative example and example 1 is that the catalyst is butyl titanate.

Effect example 1

The modified organosilicon sealants obtained in examples 1-6 are tested for tensile strength according to GB/T528; hardness was tested according to GB/T531-1999, shear strength and initial adhesion according to GB/T7124-08, tack free time according to ASTM D2377. The performance indexes are shown in table 1.

TABLE 1

As can be seen from Table 1, the modified silicone sealant of the present invention has good adhesion properties.

Finally, it should be noted that the above embodiments are intended to illustrate the technical solutions of the present invention and not to limit the scope of the present invention, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications and equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.