High-silicon content shell-core structured silicon/acrylic emulsion and method for preparing same

Abstract

The invention relates to a high-silicon content shell-core structured silicon / acrylic emulsion and method for preparation by using ethyltrimethoxysilane, acrylic acid and acrylic acid ester as monomer, peroxodisulfate as initiating agent, octyl phenol polyoxyethylene ether maleic ester sodium (OS) as emulsifying agent, sodium methacrylic acid as protection rubber, binary alcohol such as propylene glycol, or 1.4-butylene glycol or low-molecular-weight polyethylene glycol as organosilicon hydrolysis depressant, first carrying out seed (core) emulsion polymerization, then using the emulsion as seed, vinyl trialkoxy silicane and acrylic acid ester as monomer, ammonium persulphate as initiating agent, divinyl benzene as crosslinking agent, binary alcohol such as propylene glycol, or 1.4-butylene glycol or low-molecular-weight polyethylene glycol as organosilicon hydrolysis depressant, and carrying out emulsion polymerization.

Description

technical field

[0001] The invention relates to a high-silicon-content core-shell structure silicon-acrylic emulsion and a preparation method thereof. Background technique

[0002] In recent years, there have been many studies on silicone-modified polyacrylate emulsions (silicon-acrylic emulsions for short). Silicone acrylic emulsion is the raw material for preparing high-quality architectural exterior wall coatings. The purpose of the research is to improve the stain resistance, water resistance and weather resistance of polyacrylate emulsion coatings.

[0003] There are two modification methods of blending and copolymerization for modifying polyacrylate with silicone. The blending method is to mix the two emulsions of organopolysiloxane and polyacrylate in a certain ratio evenly. This method has a simple process and has been applied in actual production; but in the blending modification, there is no chemical bond between the two polymer molecular chains. Due to the lar...

Examples

Embodiment 1

[0029] The preparation of high-silicon-content core-shell structure silicon-acrylic emulsion refers to Table 2 (preparation formula of high-silicon content core-shell structure silicon-acrylic emulsion of the present invention). First, the seed emulsion was prepared according to the seed emulsion polymerization formula 1 in Table 2. Pre-emulsify the mixed monomers (methyl methacrylate, butyl acrylate, acrylic acid, vinyltrialkoxysilane), emulsifier OS and deionized water under strong stirring in a one-necked flask to obtain a pre-emulsion. Add deionized water, protective gel and hydrolysis inhibitor into the three-necked flask, stir and raise the temperature to 85°C. Put the emulsion in the dropping funnel, put the aqueous solution containing the pH adjuster and the initiator in another dropping funnel, and slowly drop the two liquids into the three-necked flask under the condition of stirring, and the dripping will be completed in about two hours. Then keep warm for one hour...

Embodiment 2

[0032] According to the formula in Table 2, high-silicon content core-shell structure silicon-acrylic emulsion 2 was prepared. The preparation method is the same as in Example 1.

Embodiment 3

[0034] According to the formula in Table 2, high-silicon-content core-shell structure silicon-acrylic emulsion 3 was prepared. The preparation method is the same as in Example 1.

technical field

[0001] The invention relates to a high-silicon-content core-shell structure silicon-acrylic emulsion and a preparation method thereof. Background technique

[0002] In recent years, there have been many studies on silicone-modified polyacrylate emulsions (silicon-acrylic emulsions for short). Silicone acrylic emulsion is the raw material for preparing high-quality architectural exterior wall coatings. The purpose of the research is to improve the stain resistance, water resistance and weather resistance of polyacrylate emulsion coatings.

[0003] There are two modification methods of blending and copolymerization for modifying polyacrylate with silicone. The blending method is to mix the two emulsions of organopolysiloxane and polyacrylate in a certain ratio evenly. This method has a simple process and has been applied in actual production; but in the blending modification, there is no chemical bond between the two polymer molecular chains. Due to the lar...

Examples

Embodiment 1

[0029] The preparation of high-silicon-content core-shell structure silicon-acrylic emulsion refers to Table 2 (preparation formula of high-silicon content core-shell structure silicon-acrylic emulsion of the present invention). First, the seed emulsion was prepared according to the seed emulsion polymerization formula 1 in Table 2. Pre-emulsify the mixed monomers (methyl methacrylate, butyl acrylate, acrylic acid, vinyltrialkoxysilane), emulsifier OS and deionized water under strong stirring in a one-necked flask to obtain a pre-emulsion. Add deionized water, protective gel and hydrolysis inhibitor into the three-necked flask, stir and raise the temperature to 85°C. Put the emulsion in the dropping funnel, put the aqueous solution containing the pH adjuster and the initiator in another dropping funnel, and slowly drop the two liquids into the three-necked flask under the condition of stirring, and the dripping will be completed in about two hours. Then keep warm for one hour...

Embodiment 2

[0032] According to the formula in Table 2, high-silicon content core-shell structure silicon-acrylic emulsion 2 was prepared. The preparation method is the same as in Example 1.

Embodiment 3

[0034] According to the formula in Table 2, high-silicon-content core-shell structure silicon-acrylic emulsion 3 was prepared. The preparation method is the same as in Example 1.