CN102532404B - High-water-resistance acrylate emulsion and preparation method thereof - Google Patents

Abstract

The invention provides a high-water-resistance acrylate emulsion. The emulsion comprises the following raw materials in percentage by weight: 20%-25% of styrene, 15%-20% of butyl acrylate, 3%-5% of methyl methacrylate, 1%-3% of acrylic acid, 1%-2% of organic silicon monomer, 1%-2% of mixed emulsifying agent, 0.5% of sodium bicarbonate, 0.5% of initiator and the balance of water. According to the invention, in the emulsion polymerization process, a reaction type emulsifying agent is adopted to carry out a polymerization reaction, and the emulsifying agent is polymerized to a large molecule chain in the polymerization process, thereby reducing the transfer of the emulsifying agent in a paint film, reducing the water adsorption rate of the paint film and improving water resistance; through adopting a nucleus-shell polymerization process, a shell polymerization part is subjected to copolymerization modification with organic silicon, so that a hydrophobic structure is formed on the surface of a latex particle, thereby improving the water resistance after film formation finally; and through the synergistic effect of the two methods, the water resistance of the prepared emulsion is greatly improved and the prepared emulsion can be widely applied to production and preparation of paints for inner and outer walls.

Description

A kind of high-water-resistance acrylate emulsion and preparation method thereof

Technical field

The present invention relates to the synthesis of polymer material field, be specially a kind of high-water-resistance acrylate emulsion that is mainly used in building coating, the present invention also comprises the preparation method of this acrylic ester emulsion.

Background technology

Building coating is very fast by the acrylic emulsion development in recent years, along with aqueous architectural coating is more and more applied in life, also more and more higher to the requirement of acrylic emulsion performance.By ordinary method, synthetic acrylic emulsion is made building coating and generally can be faced the poor problem of water resistance, and this is because emulsion can be applied to emulsifying agent and the hydrophilic monomer that some wetting abilities are stronger in preparation process.These hydrophilic component can show very strong water-absorbent at coating surface, more particularly at the small-molecular emulsifier of paint film inside, can be along with the time moves to surface, again with after water contact understanding absorption moisture, cause the paint film phenomenon such as even come off that occurs turning white, bubbles.Therefore, how improving the water resistance after emulsion film forming, be not only the important topic in the synthetic field of coating emulsion, is an important research direction of current emulsion polymerization technology.

Summary of the invention

Technical problem to be solved by this invention is to provide a kind of high-water-resistance acrylate emulsion and preparation method thereof, the water tolerance after raising coating emulsion film forming.

Technical problem of the present invention adopts following technical proposals to solve:

A kind of enhanced water resistance acrylate paint emulsion is characterized in that being prepared from by following raw material and proportioning:

Vinylbenzene: 20%～25%, butyl acrylate: 15%～20%, methyl methacrylate 3%～5%, vinylformic acid 1%～3%, organosilane monomer 1%～2%, blending emulsifiers 1%～2%, sodium bicarbonate 0.5%, initiator 0.5%, surplus is water.

Described initiator is ammonium persulphate or Sodium Persulfate.

Described organosilane monomer is γ-aminopropyl triethoxysilane (KH550) or γ-aminopropyltrimethoxysilane (KH551).

In described blending emulsifiers, the quality proportioning of each emulsifying agent is: nonionic emulsifying agent: anionic emulsifier: reactive emulsifier=1:2:1～2.

Described anionic emulsifier is sodium lauryl sulphate (K12); Described nonionic emulsifying agent is OP-10; Described reactive emulsifier is: allyloxy hydroxypropyl azochlorosulfonate acid sodium (AHPS) or hydroxyethyl methacrylate propyl sulfonic acid sodium (HMPS).

Preparation technology's flow process of aforesaid propylene acid esters coating emulsion is as follows:

(1) with 10% of water inventory in formula, initiator is dissolved, make initiator solution, standby;

(2) will fill a prescription in 60% and formula of blending emulsifiers total amount water inventory 40%, whole sodium bicarbonate, and vinylformic acid, butyl acrylate, vinylbenzene, the methyl methacrylate polymerization monomer carries out high speed dispersion, prepare pre-emulsion, pre-emulsion is divided into to A, two parts of B, the A:B weight ratio is 2:1, in B, add organosilane monomer to mix

(3) will fill a prescription in the blending emulsifiers total amount 40%, in formula, 50% of water inventory drops into reactor, be warmed up to 80-85 ℃, slowly add 6/10 of the pre-emulsion A configured and the initiator solution configured, then 3/10 of the initiator solution that drips pre-emulsion B and configure, all pre-emulsions added at 3-3.5 hour;

(4) add 1/10 of the initiator solution that configures after, keep temperature of reaction at 90 ℃, react 1 hour, be cooled to below 40 ℃, regulate emulsion viscosity, the packing discharging.

Technical characteristics of the present invention is as follows:

1, in the process of letex polymerization, adopt the emulsifying agent of response type to carry out polyreaction, emulsifying agent participates in being aggregated on macromolecular chain in polymerization process, has reduced the migration of emulsifying agent in paint film, has reduced the water-intake rate of paint film, has improved water tolerance.

2, by adopting the technique of nuclear-shell polymerization, at the shell polymeric part, adopt organosilicon to carry out modification by copolymerization, make the emulsion particle surface form a kind of hydrophobic structure, improved the water tolerance after final film forming.

By the synergy of these two kinds of methods, can make the water tolerance after prepared emulsion film forming obtain very large raising, can be widely used in the manufacture of coating for internal and external wall.

Embodiment

Embodiment 1

Vinylbenzene 20g, butyl acrylate 20g, methyl methacrylate 5g, vinylformic acid 1g, organosilane monomer KH550 1g, blending emulsifiers 2g(op-10 0.4g, K12 0.8g, AHPS 0.8g), sodium bicarbonate 0.5g, ammonium persulphate 0.5g, deionized water 50g.

(1) 0.5g ammonium persulphate and 5g water are mixed with to initiator solution.（5mL）

(2) in the 200mL four-hole bottle, the blending emulsifiers of 1.2g and 20g water, 0.5g sodium bicarbonate are mixed, then add the polymerization single polymerization monomers such as vinylformic acid 3g, butyl acrylate 20g, vinylbenzene 20g, methyl methacrylate 5g to carry out high speed dispersion, prepare the monomer pre-emulsion, pre-emulsion is divided into to A, two parts of B (the A:B weight ratio is 2:1) add organosilane monomer KH550 1g to mix in B.

(3) by the 0.8g blending emulsifiers, the water of 25g drops in the 200mL four-hole bottle, be warmed up to 80-85 ℃, successively slowly drip pre-emulsion A and the pre-emulsion B configured, drip simultaneously the total amount of initiator of initiator solution 4.5mL(90%) carry out polyreaction, whole process maintains the temperature at 80-85 ℃, and pre-emulsion and initiator all add about about 3-3.5 hour.

(4) add the total amount of initiator of initiator solution 0.5mL(10%), keep temperature of reaction at 90 ℃, react 1 hour, be cooled to below 40 ℃, regulate the emulsion pH value to 7-8 with ammoniacal liquor, filter, packing.

Embodiment 2

Vinylbenzene: 25g, butyl acrylate: 15g, methyl methacrylate 3g, vinylformic acid 3g, organosilane monomer KH551 2g, blending emulsifiers 1g(op-10 0.2g, K12 0.4g, HMPS 0.4g), sodium bicarbonate 0.5g, Sodium Persulfate 0.5g, deionized water 50g.

Reaction process is as follows:

(1) 0.5g ammonium persulphate and 5g water are mixed with to initiator solution (5mL).

(2) in the 200mL four-hole bottle, the blending emulsifiers of 0.8g and 20g water, 0.5g sodium bicarbonate are mixed, then the vinylformic acid that adds formula ratio, butyl acrylate, vinylbenzene, the polymerization single polymerization monomers such as methyl methacrylate carry out high speed dispersion, prepare the monomer pre-emulsion, and pre-emulsion is divided into to A, two parts of B (the A:B weight ratio is 2:1) add 1g KH-550 to mix in B.

(3) by the 1.2g blending emulsifiers, the water of 25g drops in the 200mL four-hole bottle, be warmed up to 80-85 ℃, successively slowly drip pre-emulsion A and the pre-emulsion B configured, drip simultaneously the total amount of initiator of initiator solution 4.32mL(90%) carry out polyreaction, whole process maintains the temperature at 80-85 ℃, and pre-emulsion and initiator all add about about 3-3.5 hour.

(4) add the total amount of initiator of initiator 0.5mL(10%), keep temperature of reaction at 90 ℃, react 1 hour, be cooled to below 40 ℃, regulate the emulsion pH value to 7-8 with ammoniacal liquor, filter, packing.

The foregoing is only and the present invention relates to the part example; other relate to example because length is limit the present invention; can not list one by one; in every case above example is done in composition and engineering given to this invention to equivalent modifications or proportioning variation according to know-why of the present invention, all within protection scope of the present invention.

Claims (1)

1. the preparation method of a high-water-resistance acrylate emulsion is characterized in that by following formula and technique preparation:

Vinylbenzene: 20%～25%, butyl acrylate: 15%～20%, methyl methacrylate 3%～5%, vinylformic acid 1%～3%, organosilane monomer 1%～2%, blending emulsifiers 1%～2%, sodium bicarbonate 0.5%, initiator 0.5%, surplus is water;

Described processing step is:

(1) with 10% of water inventory in formula, initiator is dissolved, make initiator solution, standby;

(2) will fill a prescription in 60% and formula of blending emulsifiers total amount water inventory 40%, whole sodium bicarbonate, and vinylformic acid, butyl acrylate, vinylbenzene, the methyl methacrylate polymerization monomer carries out high speed dispersion, prepares pre-emulsion, pre-emulsion is divided into to A, two parts of B, the A:B weight ratio is 2:1, in B, adds organosilane monomer to mix;

(3) will fill a prescription in the blending emulsifiers total amount 40%, in formula, 50% of water inventory drops into reactor, be warmed up to 80-85 ℃, slowly add 6/10 of the pre-emulsion A configured and the initiator solution configured, then 3/10 of the initiator solution that drips pre-emulsion B and configure, all pre-emulsions added at 3-3.5 hour;

(4) add 1/10 of the initiator solution that configures after, keep temperature of reaction at 90 ℃, react 1 hour, be cooled to below 40 ℃, regulate emulsion viscosity, the packing discharging.