Organosilicon sealant and production process thereof
Technical Field
The invention relates to an organic silicon sealant, in particular to an organic silicon sealant for PET and a production process thereof.
Background
The organic silicon sealant has good weather resistance, durability, ultraviolet aging resistance, excellent sealing property and thermal stability, wide use temperature range and good flexibility, and has wide application in the fields of buildings, automobiles, aerospace, ships, electric appliances and the like. Common silicone sealants can be classified into various types such as deacidification type, dealcoholization type, ketoxime type, deamination type, and the like according to the types of crosslinking agents and low-molecular byproducts. The deacidification type organic silicon sealant has high reactivity, good cohesiveness and low cost, and is one of important categories of organic silicon sealants.
The traditional organic silica gel adhesive is mainly applied to the building industry, such as hollow glass, glass curtain walls, externally hung wallboards, metal frame structures and the like, an adhesion object is mainly inorganic nonmetallic materials such as glass, cement, ceramics and the like or metal materials such as alloy, steel and the like, the adhesion object does not show good adhesion to polymer materials such as PET, PP, PC and the like, and the adhesive has the problems of easy stripping, falling off in a damp-heat state, poor flexibility, incomplete solidification and the like, so that a great amount of improvement space is still provided.
Disclosure of Invention
Aiming at the defects of the prior art, the invention aims to provide an organosilicon sealant and a production process thereof.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:
the organic silicon sealant comprises the following components in parts by weight: 100 parts of alpha, omega-dihydroxy polydimethylsiloxane, 10-30 parts of silicone oil, 5-30 parts of grafted white carbon black, 0-60 parts of nano calcium carbonate, 1-8 parts of cross-linking agent, 1-8 parts of silane coupling agent and 0.01-5 parts of organotin catalyst;
the grafted white carbon black is gas-phase white carbon black grafted by acrylic ester.
The grafted white carbon black comprises the following components in parts by weight: 80-100 parts of absolute ethyl alcohol, 5-20 parts of water, 1-20 parts of an aminosilane coupling agent, 3-15 parts of gas-phase white carbon black, 3-20 parts of an acrylic ester monomer, 150-250 parts of methanol and 1-5 parts of ethylenediamine.
The aminosilane coupling agent is any one or two or more than two of gamma-aminopropyl triethoxysilane, gamma-aminopropyl trimethoxysilane, N-beta-aminoethyl-gamma-aminopropyl triethoxysilane, N-beta-aminoethyl-gamma-aminopropyl methyl diethoxysilane and N, N' -bis (beta-aminoethyl) -gamma-aminopropyl trimethoxysilane.
The acrylic ester monomer is one or two or more of methyl acrylate, ethyl acrylate and butyl acrylate.
The viscosity of the alpha, omega-dihydroxy polydimethylsiloxane is 10000cs-80000cs; the viscosity of the silicone oil is 500cs-3000cs; the grain diameter of the nano calcium carbonate is less than or equal to 300nm; the grain diameter of the grafted white carbon black is less than or equal to 300nm.
The cross-linking agent is any one or two or more than two of methyl triacetoxy silane, ethyl triacetoxy silane, propyl triacetoxy silane and vinyl triacetoxy silane.
The silane coupling agent is one or two or more of KH550, KH560, KH570 and KH 792.
The organotin catalyst is any one or two or more of dibutyltin dilaurate, dibutyltin diacetate, stannous octoate and dibutyltin dilaurate.
The production process of the organic silicon sealant comprises the following steps:
(1) Weighing the components according to the proportion of the raw materials for standby;
(2) Mixing alpha, omega-dihydroxyl polydimethylsiloxane, silicone oil, grafted white carbon black and nano calcium carbonate, and vacuum kneading for 3 hours to remove excessive water to obtain uniformly mixed base adhesive;
(3) Adding a cross-linking agent and a silane coupling agent, and stirring in vacuum for 10-30min;
(4) Adding an organotin catalyst, and stirring in vacuum for 10-30min;
(5) And stirring to obtain the organosilicon sealant.
The production process of the grafted white carbon black comprises the following steps:
(1) Weighing the components according to the proportion of the raw materials for standby;
(2) According to absolute ethyl alcohol: the water is 9:1, is used for dissolving an aminosilane coupling agent to obtain an aminosilane coupling agent hydrolysate with the mass concentration of 1-20%;
(3) Adding gas-phase white carbon black into the hydrolysate of the amino silane coupling agent, and carrying out ultrasonic reaction for 6h at 60 ℃;
(4) Filtering after ultrasonic treatment, washing with absolute ethyl alcohol, and drying at 80 ℃ for 24 hours to obtain gas-phase white carbon black with amino active groups;
(5) Mixing gas-phase white carbon black with amino active groups, acrylate monomers and methanol, and reacting for 2 hours at 50 ℃;
(6) Adding ethylenediamine, and continuing to react for 4 hours at 50 ℃;
(7) And after the reaction is finished, carrying out suction filtration, washing with absolute ethyl alcohol for 3-5 times, drying at 80 ℃ for 24 hours, and grinding to obtain the acrylate grafted gas-phase white carbon black, namely the grafted white carbon black.
The invention has the beneficial effects that:
the invention relates to an organosilicon sealant for PET plastic, which is prepared by grafting gas-phase white carbon black by using an aminosilane coupling agent and acrylic ester, and is used as a reinforcing filler to be applied to silica gel.
Because the traditional gas-phase white carbon black has high specific surface area, large oil absorption value, rich hydroxyl on the surface, high hydrophilicity, difficulty in dispersing in base rubber and high thixotropic viscosity of the product, the traditional gas-phase white carbon black is unfavorable for the mechanical strength and the curing speed of silica gel, and the prepared product is low in strength, poor in adhesiveness and poor in usability. Therefore, the invention is beneficial to the grafting treatment of the acrylic ester on the common white carbon black, on one hand, increases the dispersibility of the white carbon black in the silica gel, plays a role in reducing viscosity to a certain extent, and improves the mechanical strength of the sealant; on the other hand, the adhesion between the sealant and the PET substrate is improved, so that the adhesion is greatly improved.
The organic silicon sealant for PET prepared by the invention has excellent mechanical strength, low modulus, excellent adhesive force, good damp-heat resistance and room temperature self-curing property. Wherein, the adhesive force test can reach 5B, the tensile shear strength can reach 1.068MPa,1000h wet heat resistance test: the coating does not fall off, has good adhesion, and is tested at high temperature (heating for 60min in 180 ℃) and 180 DEG bending: the coating does not fall off, has good bending flexibility, and can reach 8 levels in salt spray corrosion resistance test. The invention solves the problems of poor adhesiveness, easy peeling due to damp and heat and the like of the traditional organic silicon sealant on polymer products, and has wide application prospect.
Drawings
FIG. 1 is a flow chart of a grafting modification process of the gas phase white carbon black.
Detailed Description
The following describes the embodiments of the present invention in further detail with reference to examples. Unless otherwise specified, the instruments and devices involved in the embodiments are all conventional instruments and devices; the related raw materials are all conventional raw materials sold in the market; the related test methods are all conventional methods.
Example 1 production Process of grafted white carbon Black
The grafted white carbon black comprises the following components in parts by weight: 90 parts of absolute ethyl alcohol, 10 parts of water, 5 parts of gamma-aminopropyl triethoxy silane coupling agent, 12 parts of gas-phase white carbon black, 15 parts of methyl acrylate monomer, 200 parts of methanol and 2 parts of ethylenediamine.
The production process of the grafted white carbon black comprises the following steps:
(1) Weighing the components according to the proportion of the raw materials for standby;
(2) According to absolute ethyl alcohol: the water is 9:1, is used for dissolving gamma-aminopropyl triethoxysilane coupling agent to obtain gamma-aminopropyl triethoxysilane hydrolysate with mass concentration of 5%;
(3) Adding gas-phase white carbon black into gamma-aminopropyl triethoxysilane hydrolysate, and performing ultrasonic reaction at 60 ℃ for 6h at 30-80 KHz;
(4) Filtering after ultrasonic treatment, washing with absolute ethyl alcohol for 3-5 times, and drying at 80 ℃ for 24 hours to obtain gas-phase white carbon black with amino active groups;
(5) Mixing gas-phase white carbon black with amino active groups, methyl acrylate monomer and methanol, and reacting for 2 hours at 50 ℃;
(6) Adding ethylenediamine, and continuing to react for 4 hours at 50 ℃;
(7) And after the reaction is finished, carrying out suction filtration, washing 3-5 times by using absolute ethyl alcohol, drying at 80 ℃ for 24 hours, and grinding to obtain the acrylate grafted gas-phase white carbon black, namely the grafted white carbon black.
Example 2 production Process of grafted white carbon Black
The grafted white carbon black comprises the following components in parts by weight: 85 parts of absolute ethyl alcohol, 15 parts of water, 5 parts of gamma-aminopropyl trimethoxy silane coupling agent, 12 parts of gas-phase white carbon black, 15 parts of butyl acrylate monomer, 200 parts of methanol and 2.5 parts of ethylenediamine.
The production process of the grafted white carbon black is the same as in example 1.
Example 3
The grafted white carbon black comprises the following components in parts by weight: 95 parts of absolute ethyl alcohol, 5 parts of water, 4 parts of N-beta-aminoethyl-gamma-aminopropyl triethoxysilane coupling agent, 10 parts of gas-phase white carbon black, 13 parts of ethyl acrylate monomer, 200 parts of methanol and 1.5 parts of ethylenediamine.
The production process of the grafted white carbon black is the same as in example 1.
Example 4 production Process of Silicone sealants
The organic silicon sealant comprises the following components in parts by weight: 100 parts of alpha, omega-dihydroxy polydimethylsiloxane (107 glue), 20 parts of silicone oil, 10 parts of grafted white carbon black, 40 parts of nano calcium carbonate, 3 parts of methyl triacetoxy silane, 2 parts of vinyl triacetoxy silane, 2 parts of KH570 silane coupling agent and 1.5 parts of dibutyltin diacetate.
Wherein the viscosity of the alpha, omega-dihydroxy polydimethylsiloxane is 10000cs-80000cs; the viscosity of the silicone oil is 500cs-3000cs; the grafted white carbon black is prepared in example 1; the grain diameter of the grafted white carbon black is less than or equal to 300nm; the grain diameter of the nano calcium carbonate is less than or equal to 300nm.
The production process of the organic silicon sealant comprises the following steps:
(1) Weighing the components according to the proportion of the raw materials for standby;
(2) Firstly, mixing 107 glue, silicone oil, grafted white carbon black and nano calcium carbonate, and vacuum kneading for 3 hours in a kneader to remove excessive water to obtain evenly mixed base glue;
(3) Adding methyltriacetoxysilane, vinyltriacetoxysilane and KH570 silane coupling agent, and vacuum mixing for 30min;
(4) Adding dibutyl tin diacetate, and vacuum mixing for 15min;
(5) Extruding and bottling to obtain the organic silicon sealant for PET.
Example 5 production Process of Silicone sealants
The organic silicon sealant comprises the following components in parts by weight: 100 parts of alpha, omega-dihydroxy polydimethylsiloxane (107 glue), 20 parts of silicone oil, 8 parts of grafted white carbon black, 50 parts of nano calcium carbonate, 4 parts of methyl triacetoxy silane, 4 parts of propyl triacetoxy silane, 2 parts of KH560 silane coupling agent and 1.5 parts of dibutyltin diacetate.
The grafted white carbon black is prepared in example 2; the performance parameters of the raw materials and the production process of the organosilicon sealant are the same as in example 4.
Example 6 production Process of Silicone sealants
The organic silicon sealant comprises the following components in parts by weight: 100 parts of alpha, omega-dihydroxy polydimethylsiloxane (107 glue), 30 parts of silicone oil, 12 parts of grafted white carbon black, 30 parts of nano calcium carbonate, 2 parts of propyl triacetoxy silane, 4 parts of vinyl triacetoxy silane, 5 parts of KH560 silane coupling agent and 1.5 parts of dibutyl tin dilaurate.
The grafted white carbon black is prepared in example 1; the performance parameters of the raw materials and the production process of the organosilicon sealant are the same as in example 4.
Example 7 production Process of Silicone sealants
The organic silicon sealant comprises the following components in parts by weight: 100 parts of alpha, omega-dihydroxy polydimethylsiloxane (107 glue), 30 parts of silicone oil, 5 parts of grafted white carbon black, 60 parts of nano calcium carbonate, 4 parts of methyltriacetoxysilane, 3 parts of vinyl triacetoxysilane, 4 parts of KH560 silane coupling agent and 1.5 parts of dibutyltin dilaurate.
The grafted white carbon black is prepared in example 3; the performance parameters of the raw materials and the production process of the organosilicon sealant are the same as in example 4.
Production process of organosilicon sealant of comparative example 1
The comparative example used a conventional fumed silica which had not been subjected to a grafting treatment.
The organic silicon sealant comprises the following components in parts by weight: 100 parts of alpha, omega-dihydroxy polydimethylsiloxane (107 glue), 20 parts of silicone oil, 10 parts of gas-phase white carbon black, 40 parts of nano calcium carbonate, 3 parts of methyl triacetoxy silane, 3 parts of vinyl triacetoxy silane, 5 parts of KH570 silane coupling agent and 1.5 parts of dibutyltin diacetate.
The performance parameters of the raw materials and the production process of the organosilicon sealant are the same as in example 4.
Performance measurement
The products obtained in examples 4 to 7 and comparative example 1 were subjected to performance test, and the results are shown in Table 1 below.
TABLE 1