阅读说明：本技术 一种改性天然橡胶防水乳液及其制备方法 (Modified natural rubber waterproof emulsion and preparation method thereof ) 是由 王廷龙 于 2019-09-18 设计创作，主要内容包括：本发明涉及防水技术领域,具体地,涉及一种改性天然橡胶防水乳液。所述改性天然橡胶防水乳液,包括如下质量百分含量的各组分：天然橡胶40-70％；阳离子乳液：25-35％；引发剂0.5-6％；乳化剂：0.5-6％；胶黏剂：2-8％；助剂:2-5％。所述改性天然橡胶防水乳液,具有优异的防水性能,抗酸碱性好,具有防腐,防潮性能,能够低温快速成膜,干燥后透明度度高,无色差,无凝胶,无结块,固含量达到50％以上。(The invention relates to the technical field of water prevention, in particular to a modified natural rubber waterproof emulsion. The modified natural rubber waterproof emulsion comprises the following components in percentage by mass: 40-70% of natural rubber; cationic emulsion: 25 to 35 percent; 0.5 to 6 percent of initiator; emulsifier: 0.5-6%; adhesive: 2 to 8 percent; 2 to 5 percent of auxiliary agent. The modified natural rubber waterproof emulsion has excellent waterproof performance, good acid and alkali resistance, corrosion resistance and moisture resistance, can form a film quickly at low temperature, has high transparency after drying, no color difference, no gel and no agglomeration, and has solid content of more than 50 percent.)

1. The modified natural rubber waterproof emulsion is characterized by comprising the following components in percentage by mass:

2. the modified natural rubber waterproof emulsion according to claim 1, which comprises the following components in percentage by mass:

3. the modified natural rubber waterproof emulsion according to claim 1 or 2, wherein the emulsifier is a polyurethane-acrylate composite latex.

4. The modified natural rubber waterproof emulsion of claim 3, wherein the polyurethane-acrylate composite emulsion is prepared by the following steps: adding polyester polyol into a reaction kettle, heating to 78-82 ℃, adding diisocyanate under the protection of inert gas, reacting for 1 hour, adding dihydroxypropionic acid (DMPA) to react for 3 hours to obtain a polyurethane prepolymer, cooling to 55-65 ℃, adding butyl methacrylate (BA) to reduce the system viscosity, adding Triethylamine (TEA) to neutralize and salify for 0.5 hour, cooling to room temperature, adding water to emulsify, and simultaneously adding a chain extender EDA to react for 1 hour to obtain aqueous polyurethane latex;

dropping the aqueous polyurethane latex into acrylic acid monomer, mixing and pre-emulsifying for 0.5h, heating to 55-65 ℃, adding buffer sodium bicarbonate and 1/4 initiator ammonium persulfate, heating to 78-82 ℃, dropping the rest initiator ammonium persulfate, and reacting at constant temperature for 2 hours to obtain the polyurethane-acrylate composite latex.

5. The modified natural rubber waterproof emulsion of claim 1 or 2, wherein the initiator is one or a mixture of ammonium persulfate, potassium persulfate and sodium persulfate.

6. The modified natural rubber waterproof emulsion according to claim 1 or 2, wherein the adhesive is selected from one or a mixture of more of neoprene adhesive, epoxy adhesive, polyurethane adhesive, polyvinyl acetate adhesive, and natural rubber adhesive.

7. The modified natural rubber waterproof emulsion according to claim 1 or 2, wherein the auxiliary comprises the following components in percentage by mass based on the total mass of the waterproof emulsion:

defoaming agent: 0.5-2%;

a stabilizer: 0.5-1%;

thickening agent: 0.25 to 0.5 percent;

and (3) bactericide: 0.25 to 0.5 percent;

multifunctional auxiliary agent: 0.5 to 1 percent.

8. The modified natural rubber waterproof emulsion according to claim 7, wherein the defoaming agent is a polyether silicone oil defoaming agent or a silicone oil emulsion defoaming agent; the stabilizer is gas phase titanium dioxide, purchased from AEROXIDE, or nano cerium dioxide; the thickening agent is polyacrylate thickening agent and polyurethane thickening agent; the bactericide is oxazoline such as isothiazolinone, benzisothiazolinone or a mixture of isothiazolinone and benzisothiazolinone; the multifunctional auxiliary agent is AMP-95 or AMP-96.

9. The method for preparing the modified natural rubber waterproof emulsion according to any one of claims 1 to 8, characterized by comprising the steps of:

(1) heating the reaction kettle to 60-80 ℃, adding the natural rubber and the cationic emulsion, uniformly mixing, adding the initiator, the emulsifier and the adhesive, reacting, stirring at 60-120rpm, and reacting for 30-40 min;

(2) and (3) cooling to room temperature through water circulation in a reaction kettle, adding an auxiliary agent, stirring at 60-120rpm, reacting for 10-20min, and cooling to room temperature to obtain the modified natural rubber waterproof emulsion.

10. The method of claim 9, further comprising the step of pretreating the natural rubber by: obtaining a natural rubber raw material, and filtering to remove impurities; then dehydrating and deproteinizing; and then mixing the mixture with ammonia water with the concentration of 1%, and dispersing the mixture by using a high-speed dispersion machine to obtain the natural rubber.

Technical Field

The invention relates to the technical field of water prevention, in particular to modified natural rubber waterproof emulsion and a preparation method thereof.

Background

The polymer cement waterproof paint is prepared by taking modified polymer emulsion and cement as main raw materials and adding various auxiliaries and inorganic fillers, has good film-forming property, and is suitable for waterproofing, seepage-proofing and damp-proofing of projects such as kitchens, toilets, basements and the like.

For example, the chinese patent document cn201810956051.x discloses a polymer cement waterproof coating, which comprises a liquid material and a powder material, wherein the liquid material comprises the following components in parts by weight: 50-60 parts of ethylene-vinyl acetate emulsion, 0.3-0.9 part of emulsifier, 15-30 parts of plasticizing emulsion, 0.6-1.2 parts of dispersant and 10-15 parts of water; the powder comprises the following components in parts by weight: 30-40 parts of cement, 20-30 parts of quartz powder, 20-30 parts of slag, 0.2-0.6 part of water reducing agent and the like. The coating utilizes ethylene-vinyl acetate emulsion as waterproof emulsion. The ethylene-vinyl acetate emulsion contains very strong polar groups, has good bonding strength, does not pollute the environment, has low price and is widely applied to building decoration. However, the ethylene-vinyl acetate emulsion has the defects of high glass transition temperature, poor low-temperature film forming property, poor water resistance, cold resistance, poor mechanical stability and the like, so that the application of the ethylene-vinyl acetate emulsion is greatly limited. And the emulsion containing ethylene-vinyl acetate turns white when contacting water, which cannot meet the field with higher requirements on the waterproof performance of the emulsion.

Moreover, because the coating is a curing mechanism that cement and polymer emulsion are mutually cooperated along with water volatilization, the drying speed of the coating is obviously reduced in a closed environment with the temperature of less than or equal to 10 ℃ and the humidity of more than or equal to 80 percent or a more complex environment, and the progress of engineering construction is influenced to a certain extent.

Therefore, the development of a waterproof emulsion suitable for the coating has great practical significance.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides the modified natural rubber waterproof emulsion which has excellent waterproof performance, good acid and alkali resistance, corrosion resistance and moisture resistance, can form a film quickly at low temperature, has high transparency after drying, no color difference, no gel and no agglomeration, and has the solid content of more than 50 percent.

The technical scheme of the invention is as follows: the modified natural rubber waterproof emulsion comprises the following components in percentage by mass:

preferably, the modified natural rubber waterproof emulsion comprises the following components in percentage by mass:

the emulsifier is polyurethane-acrylate composite latex. The preparation method comprises the following steps: adding polyester polyol into a reaction kettle, heating to 78-82 ℃, adding diisocyanate under the protection of inert gas, reacting for 1 hour, adding dihydroxypropionic acid (DMPA) to react for 3 hours to obtain a polyurethane prepolymer, cooling to 55-65 ℃, adding butyl methacrylate (BA) to reduce the system viscosity, adding Triethylamine (TEA) to neutralize and salify for 0.5 hour, cooling to room temperature, adding water to emulsify, and simultaneously adding a chain extender EDA to react for 1 hour to obtain the waterborne polyurethane latex.

Dropping the aqueous polyurethane latex into acrylic acid monomer, mixing and pre-emulsifying for 0.5h, heating to 55-65 ℃, adding buffer sodium bicarbonate and 1/4 initiator ammonium persulfate, heating to 78-82 ℃, dropping the rest initiator ammonium persulfate, and reacting at constant temperature for 2 hours to obtain the polyurethane-acrylate composite latex.

The initiator is one or a mixture of ammonium persulfate, potassium persulfate and sodium persulfate.

The adhesive is selected from one or a mixture of more of neoprene phenolic adhesive, epoxy resin adhesive, polyurethane adhesive, polyvinyl acetate adhesive and natural rubber adhesive.

The auxiliary agent comprises the following components in percentage by mass based on the total mass of the waterproof emulsion:

defoaming agent: 0.5-2%;

a stabilizer: 0.5-1%;

thickening agent: 0.25 to 0.5 percent;

and (3) bactericide: 0.25 to 0.5 percent;

multifunctional auxiliary agent: 0.5 to 1 percent.

The defoaming agent is polyether silicone oil defoaming agent or silicone oil emulsion defoaming agent

The stabilizer is fumed titanium dioxide, available from AEROXIDE, or nano-ceria.

The thickening agent is polyacrylate thickening agent and polyurethane thickening agent.

The bactericide is oxazoline such as isothiazolinone, benzisothiazolinone, or a mixture of isothiazolinone and benzisothiazolinone.

The multifunctional auxiliary agent is AMP-95 or AMP-96.

The preparation method of the modified natural rubber waterproof emulsion comprises the following steps:

(3) heating the reaction kettle to 60-80 ℃, adding the natural rubber and the cationic emulsion, uniformly mixing, adding the initiator, the emulsifier and the adhesive, reacting, stirring at 60-120rpm, and reacting for 30-40 min;

(4) and (3) cooling to room temperature through water circulation in a reaction kettle, adding an auxiliary agent, stirring at 60-120rpm, reacting for 10-20min, and cooling to room temperature to obtain the modified natural rubber waterproof emulsion.

Preferably, the method further comprises the step of pretreating the natural rubber: obtaining a natural rubber raw material, and filtering to remove impurities; then dehydrating and deproteinizing; then mixing with 1% ammonia water, dispersing with high speed disperser, and storing for use.

The invention has the beneficial effects that: through detection, the modified natural rubber waterproof emulsion disclosed by the invention is excellent in waterproof performance, and does not foam, fall off or whiten after being soaked in water for 48 hours after being coated on a glass plate.

The modified natural rubber waterproof emulsion is transparent in appearance, free of color difference, gel and agglomeration after being dried.

The modified natural rubber waterproof emulsion can quickly form a film at low temperature, has high bonding strength, good elasticity, excellent ageing resistance and good acid and alkali resistance, and has corrosion resistance and moisture resistance.

Detailed Description

In order to make the object, technical solution and technical effect of the present invention more apparent, the present invention will be further described with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.