CN111303719A - Pure acrylic emulsion with excellent water resistance and stain resistance for matte finish surface and preparation method thereof - Google Patents

Abstract

The invention discloses a matte finish surface pure acrylic emulsion with excellent water resistance and stain resistance, which is prepared from the following raw materials in parts by weight: 15-30 parts of methyl methacrylate, 5-15 parts of isooctyl acrylate, 10-15 parts of butyl methacrylate, 1-3 parts of an organic silicon assistant, 0.5-5 parts of a crosslinking monomer, 2-4 parts of a carboxyl functional monomer, 1-3 parts of an emulsifier, 0.5-1 part of an initiator, 1-5 parts of a film-forming assistant, 1-5 parts of a pH regulator and 55-65 parts of deionized water. The pure acrylate emulsion disclosed by the invention has excellent water resistance, water white resistance, stain resistance and yellowing resistance, is controllable in glossiness, has better stability and universality, and is a product for matte finish varnish which is in urgent need in the market at present.

Description

Pure acrylic emulsion with excellent water resistance and stain resistance for matte finish surface and preparation method thereof

Technical Field

The invention relates to a matte finish surface pure acrylic emulsion with excellent water resistance and stain resistance and a preparation method thereof.

Background

The matte finish varnish is taken as a first protective barrier of the building exterior wall coating, products with excellent performance are more and more popular and valued in the market, and the matte finish varnish is taken as one of the finish coatings, so that the matte finish varnish is more popular in the market because of bringing comfortable, elegant and soft feeling to people. Most of traditional matte finishing surfaces are formed by adding matting powder into a paint or emulsion formula or blending two or more immiscible systems to achieve a matte effect, and although a series of matte finishing paints with different matte degrees can be synthesized, the problems of layering, water distribution and the like easily occur in the storage process of the varnish, and the problems of inconsistent glossiness, poor water resistance, white or blue phase of a paint film and the like also occur in the use process, so that the use of the matte finishing surfaces in the fields of colorful paints, texture paints and the like is greatly limited. Of course,

at present, a product adopts a pure organic material to synthesize a matte emulsion to be used as a finish coat, Chinese patent CN106608943A synthesizes a single-component matte finish coat emulsion with controllable glossiness by adjusting the neutralization degree of a nuclear layer olefine acid functional monomer, and the emulsion has excellent water-white resistance, low glossiness and good storage stability, but the contamination resistance of the emulsion is not shown to reach the standard HG/T5065-2016; chinese patent CN 109897490A introduces a matte high stain-resistant finish varnish and a preparation method thereof, although the stain resistance is excellent, the stain resistance is mainly provided by a nano stain-resistant agent and a composite inorganic adhesive which are added into the varnish, and the additives with poor compatibility with emulsion influence the stability, water resistance and other properties of the varnish, so that a matte finish emulsion with water resistance, excellent stain resistance, low glossiness, good stability and strong universality is urgently needed in the market at present to meet the market demand.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a matte finish surface pure acrylic emulsion with excellent water resistance and stain resistance and a preparation method thereof.

In order to achieve the purpose, the matte finish surface pure acrylic emulsion with excellent water resistance and stain resistance is prepared from the following raw materials in parts by weight: 15-30 parts of methyl methacrylate, 5-15 parts of isooctyl acrylate, 10-15 parts of butyl methacrylate, 1-3 parts of an organic silicon assistant, 0.5-5 parts of a crosslinking monomer, 2-4 parts of a carboxyl functional monomer, 1-3 parts of an emulsifier, 0.5-1 part of an initiator, 1-5 parts of a film-forming assistant, 1-5 parts of a pH regulator and 55-65 parts of deionized water.

The organic silicon assistant adopts one or more than two of vinyl trimethoxy silane, vinyl triethoxy silane, methacryloxypropyl trimethoxy silane, vinyl tri (β -methoxyethoxy) silane and gamma- (2, 3-epoxypropoxy) propyl trimethoxy silane.

The crosslinking monomer is one or more than two of acrylamide, glycidyl methacrylate, ethylene glycol dimethacrylate and hydroxyethyl methacrylate.

The carboxyl functional monomer is one or more than two of acrylic acid, methacrylic acid, itaconic acid and maleic anhydride.

The emulsifier is one or more of sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, alkyl polyoxyethylene ether, sodium vinyl sulfonate, lauryl alcohol ether phosphate, reactive emulsifiers COPS-1 and COPS-2, reactive emulsifiers SR-10 and SR-20.

The initiator is one or more than two of ammonium persulfate, potassium persulfate and sodium persulfate.

The film-forming auxiliary agent is one or more than two of 2,2, 4-trimethyl-1, 3-pentanediol monoisobutyrate, propylene glycol phenyl ether, propylene glycol butyl ether and OE-300.

The pH regulator adopts one or more than two of ammonia water, sodium hydroxide and 2-amino-2-methyl-1-propanol.

In addition, the preparation method of the matte finish surface pure acrylic emulsion with excellent water resistance and stain resistance comprises the following steps:

1) under the conditions of normal temperature and normal pressure, respectively adding 5-10 parts of methyl methacrylate, 3-7 parts of isooctyl acrylate, 0.5-1 part of organic silicon assistant, 0.2-2 parts of crosslinking monomer, 0.2-0.5 part of carboxyl functional monomer, 0.2-1 part of emulsifier, 0.1-0.3 part of initiator and 10-20 parts of deionized water into an emulsifying cylinder, and stirring and dispersing to prepare a nuclear layer pre-emulsion for later use;

2) adding 20-30 parts of deionized water into a reaction kettle, adding 0.2-0.5 part of emulsifier, stirring, and heating to 81-86 ℃ for later use;

3) adding 1-10% of the total mass of the nuclear layer pre-emulsion prepared in the step 1) into the reaction kettle in the step 2), adding 0.2-0.3 of initiator, preserving the temperature at 81-86 ℃ for 10-20min, and then dropwise adding the rest nuclear layer pre-emulsion for 1-2 h;

4) adding 9-15 parts of methyl methacrylate, the balance of isooctyl acrylate, the formula amount of butyl methacrylate, the balance of organosilicon auxiliary agent, the balance of crosslinking monomer, 0.2-0.8 part of emulsifier, the balance of initiator, 0.5-1.5 parts of pH regulator and 12-20 parts of deionized water into an emulsion cylinder I, and dispersing and stirring for 25-35 min; adding the balance of methyl methacrylate, the balance of carboxylic acid functional monomers, the balance of emulsifying agents and the balance of deionized water into a second emulsifying cylinder, and dispersing and stirring for 25-35min to respectively obtain a shell layer pre-emulsion for later use;

5) after finishing dripping the nuclear layer pre-emulsion, preserving heat for 35-45min at the temperature of 81-86 ℃, then dripping the pre-emulsion in the first emulsifying cylinder by a pump into the first emulsifying cylinder for 1-2h, simultaneously dripping the mixed pre-emulsion in the first emulsifying cylinder into a reaction kettle for 1.5-2.5h, and preserving heat for 0.5-1.5h at the temperature of 81-86 ℃ after finishing dripping;

6) cooling to 50 ℃, adding the rest of pH regulator, regulating the pH value of the emulsion, slowly adding the film-forming assistant in the formula amount, keeping the temperature at 50 ℃, stirring for 0.5 hour, and discharging.

Wherein, the mechanical stirring state is maintained in the whole process of each step of the invention.

The matte finish surface pure acrylic emulsion with excellent water resistance and stain resistance, which is prepared by the method, has the viscosity within 2000CPS (3#12r) and the minimum film forming temperature of 15-30 ℃. The emulsion can be mainly used as the outer wall building coating finish coat.

The application mechanism of the invention is as follows:

the matte effect of the invention is mainly provided by a unique dropping mode of the shell layer, the gradually-changed dropping mode leads the carboxyl functional monomers to be gradually increased from inside to outside on the shell layer and to be neutralized in the reaction process, and a special phase separation structure can be formed after the emulsion is formed into a film, the rough micro-phase structure can be changed by the amount of the carboxyl functional monomer and the dropping speed, so as to control the matte degree of the emulsion film, the crosslinking association point and the crosslinking monomer provided by the reactive emulsifier or the phosphate ester emulsifier in the system, the long-chain and short-chain crosslinking reaction and the copolymerization reaction between the organic silicon improve the crosslinking degree of the polymer, the multi-dimensional crosslinking effect greatly improves the compactness degree and the water-white resistance of the emulsion film, meanwhile, the mechanical strength is also improved, and the emulsion has an excellent stain resistance by matching with the proper core-shell Tg ratio of the emulsion and a special phase separation structure on the surface of a shell layer.

Compared with the prior art, the invention has the beneficial effects that:

the invention adopts common acrylate monomer, does not contain inorganic functional compound, and can obtain the emulsion for the cover surface with different matte degrees by only designing proper core-shell proportion and simultaneously changing the distribution of shell carboxyl through a core-shell emulsion polymerization process, the raw material process is simple, the operability is strong, the defects of poor water-white resistance, inconsistent blue phase and matte degree and the like caused by matting powder or an immiscible system to a paint film are avoided, meanwhile, the unique crosslinking system and the special micro-phase structure bring excellent stain resistance, and compared with the process for improving the stain resistance by using a high Tg or nano stain resistance agent, the temperature change resistance and the stability of the product are better. The pure acrylate emulsion has excellent water resistance, water white resistance, stain resistance and yellowing resistance, has controllable glossiness, has good stability and universality, and is a product for matte finish varnish which is in urgent need in the market at present.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below. It should be understood, however, that the description herein of specific embodiments is only intended to illustrate the invention and not to limit the scope of the invention.

Example 1

A matte finish surface pure acrylic emulsion with excellent water resistance and stain resistance is prepared from the following raw materials in parts by weight: 30 parts of methyl methacrylate, 10 parts of isooctyl acrylate, 15 parts of butyl methacrylate, 3 parts of an organic silicon assistant (vinyl trimethoxy silane and methacryloxypropyl trimethoxy silane), 3 parts of a crosslinking monomer (acrylamide and hydroxyethyl methacrylate), 3 parts of a carboxyl functional monomer (acrylic acid), 2 parts of an emulsifier (sodium dodecyl sulfate, a reactive emulsifier COPS-1 of Rodiya company and a reactive emulsifier SR-10 of Japanese Adeca company), 1 part of an initiator (ammonium persulfate), 5 parts of a film-forming assistant (2,2, 4-trimethyl-1, 3-pentanediol monoisobutyrate), 5 parts of a pH regulator (ammonia water) and 65 parts of deionized water.

The preparation method of the matte finish surface pure acrylic emulsion with excellent water resistance and stain resistance comprises the following steps:

1) under the conditions of normal temperature and normal pressure, respectively adding 10 parts of methyl methacrylate, 7 parts of isooctyl acrylate, 1 part of vinyl trimethoxy silane, 0.2 part of acrylamide, 0.2 part of acrylic acid, 0.2 part of sodium dodecyl sulfate, 0.3 part of reactive emulsifier SR-10 of Japan Ediko company, 0.3 part of ammonium persulfate and 20 parts of deionized water into an emulsifying cylinder, and stirring and dispersing for 30min to prepare a nuclear layer pre-emulsion for later use;

2) adding 20 parts of deionized water into a reaction kettle, adding 0.5 part of sodium dodecyl sulfate, stirring, and heating to 86 ℃ for later use;

3) adding 10% of the total mass of the nuclear layer pre-emulsion prepared in the step 1) into the reaction kettle in the step 2), adding 0.3 part of ammonium persulfate, preserving the temperature at 86 ℃ for 20min, and then dropwise adding the rest of the nuclear layer pre-emulsion for 2 h;

4) adding 15 parts of methyl methacrylate, 3 parts of isooctyl acrylate, 15 parts of butyl methacrylate, 0.5 part of vinyl trimethoxy silane, 1.5 parts of methacryloxypropyl trimethoxy silane, 0.8 part of acrylamide, 2 parts of hydroxyethyl methacrylate, 0.5 part of reactive emulsifier SR-10 of Adeca, 0.3 part of reactive emulsifier COPS-1 of Rodiya, 0.4 part of ammonium persulfate, 1.5 parts of ammonia water and 20 parts of deionized water into an emulsion cylinder for dispersing and stirring for 35 min; adding 5 parts of methyl methacrylate, 2.8 parts of acrylic acid, 0.2 part of sodium dodecyl sulfate and 5 parts of deionized water into a second emulsifying cylinder, and dispersing and stirring for 35min to respectively obtain a shell layer pre-emulsion for later use;

5) after finishing dripping the nuclear layer pre-emulsion, preserving heat for 45min at 86 ℃, then dripping the pre-emulsion in the second emulsifying cylinder into the first emulsifying cylinder through a pump for 2h, dripping the mixed pre-emulsion in the first emulsifying cylinder into the reaction kettle for 2.5h, and preserving heat for 1.5h at 86 ℃ after finishing dripping;

6) after the temperature is reduced to 50 ℃, 3.5 parts of ammonia water is added to adjust the pH value of the emulsion, 5 parts of 2,2, 4-trimethyl-1, 3-pentanediol monoisobutyrate is slowly added, the temperature is kept at 50 ℃, and the mixture is stirred for 0.5 hour and then discharged.

The pure acrylic emulsion for the matte finishing surface with excellent stain resistance and water resistance, prepared by the method, has the viscosity within 2000CPS (3#12r) and the minimum film forming temperature of 15 ℃.

Example 2

15 parts of methyl methacrylate, 5 parts of isooctyl acrylate, 13 parts of butyl methacrylate, 2 parts of organosilicon auxiliaries (vinyl triethoxysilane, vinyl tris (β -methoxyethoxy) silane), 5 parts of crosslinking monomers (acrylamide, ethylene glycol dimethacrylate), 2 parts of carboxyl functional monomers (methacrylic acid), emulsifiers (sodium dodecyl benzene sulfonate, sodium vinyl sulfonate, a reactive emulsifier COPS-2 of Rodiya corporation, a reactive emulsifier SR-10 of Japan Aidicke corporation) 1.5 parts, an initiator (potassium persulfate) 0.9 part, a film-forming aid (OE-300 of Islaman corporation) 1 part, pH regulators (ammonia water and sodium hydroxide) 3 parts and deionized water 55 parts.

The preparation method of the matte finish surface pure acrylic emulsion with excellent water resistance and stain resistance comprises the following steps:

1) under the conditions of normal temperature and normal pressure, respectively adding 5 parts of methyl methacrylate, 3 parts of isooctyl acrylate, 0.5 part of vinyltriethoxysilane, 0.5 part of acrylamide, 1.5 parts of ethylene glycol dimethacrylate, 0.3 part of methacrylic acid, 0.2 part of sodium dodecyl benzene sulfonate, 0.2 part of potassium persulfate and 15 parts of deionized water into an emulsifying cylinder, and stirring and dispersing for 30min to prepare a core layer pre-emulsion for later use;

2) adding 20 parts of deionized water into a reaction kettle, adding 0.2 part of sodium dodecyl benzene sulfonate, stirring, and heating to 81-86 ℃ for later use;

3) adding 5% of the total mass of the nuclear layer pre-emulsion prepared in the step 1) into the reaction kettle in the step 2), adding 0.3 part of potassium persulfate, preserving the temperature at 82 ℃ for 15min, and then dropwise adding the rest of the nuclear layer pre-emulsion for 1.5 h;

4) adding 9 parts of methyl methacrylate, 2 parts of isooctyl acrylate, 13 parts of butyl methacrylate, 1.5 parts of vinyl tri (β -methoxyethoxy) silane, 0.5 part of acrylamide, 2.5 parts of ethylene glycol dimethacrylate, 0.3 part of a reactive emulsifier COPS-2 of the company Rodiya, 0.4 part of a reactive emulsifier SR-10 of the company Nippon Aidi, 0.4 part of potassium persulfate, 1 part of ammonia water and 17 parts of deionized water into an emulsification cylinder I, dispersing and stirring for 30min, adding 1 part of methyl methacrylate, 1.7 parts of methacrylic acid, 0.2 part of a reactive emulsifier SR-10 of the company Nippon Aidi, 0.2 part of sodium vinylsulfonate and 3 parts of deionized water into the emulsification cylinder II, dispersing and stirring for 30min, and respectively obtaining a shell layer pre-emulsion for later use;

5) after finishing dripping the nuclear layer pre-emulsion, preserving heat for 40min at 83 ℃, then dripping the pre-emulsion in the emulsion cylinder II into the emulsion cylinder I through a pump for 1.5h, dripping the mixed pre-emulsion in the emulsion cylinder I into the reaction kettle for 2h, and preserving heat for 1h at 83 ℃ after finishing dripping;

6) after the temperature is reduced to 50 ℃,2 parts of sodium hydroxide is added to adjust the pH value of the emulsion, 1 part of OE-300 of Iseman company is slowly added, the temperature is kept at 50 ℃, and the mixture is stirred for 0.5 hour and then discharged.

The pure acrylic emulsion for the matte finishing surface with excellent water resistance and stain resistance, which is prepared by the method, has the viscosity within 2000CPS (3#12r) and the minimum film forming temperature of 30 ℃.

Example 3

A matte finish surface pure acrylic emulsion with excellent water resistance and stain resistance is prepared from the following raw materials in parts by weight: 25 parts of methyl methacrylate, 8 parts of isooctyl acrylate, 10 parts of butyl methacrylate, 1 part of organosilicon auxiliary agent (vinyl trimethoxy silane, gamma- (2, 3-epoxypropoxy) propyl trimethoxy silane), 0.5 part of crosslinking monomer (acrylamide and glycidyl methacrylate), 4 parts of carboxyl functional monomer (methacrylic acid and itaconic acid), 3 parts of emulsifier (sodium dodecyl sulfate, alkyl polyoxyethylene ether and reactive emulsifier SR-10 and SR-20 of Idiaceae company, Japan), 0.5 part of initiator (sodium persulfate), 3 parts of film-forming auxiliary agent (propylene glycol phenyl ether), 4 parts of pH regulator (ammonia water and 2-amino-2-methyl-1-propanol) and 60 parts of deionized water.

The preparation method of the matte finish surface pure acrylic emulsion with excellent water resistance and stain resistance comprises the following steps:

1) under the conditions of normal temperature and normal pressure, respectively adding 8 parts of methyl methacrylate, 4 parts of isooctyl acrylate, 0.5 part of vinyl trimethoxy silane, 0.2 part of acrylamide, 0.5 part of methacrylic acid, 0.6 part of sodium dodecyl sulfate, 0.4 part of alkyl polyoxyethylene ether, 0.1 part of sodium persulfate and 10 parts of deionized water into an emulsifying cylinder, and stirring and dispersing for 30min to prepare a nuclear layer pre-emulsion for later use;

2) adding 25 parts of deionized water into a reaction kettle, adding 0.5 part of reactive emulsifier SR-10 from Idecaco, Japan, stirring, and heating to 84 ℃ for later use;

3) adding 3% of the total mass of the nuclear layer pre-emulsion prepared in the step 1) into the reaction kettle in the step 2), adding 0.2 part of sodium persulfate, preserving the temperature at 84 ℃ for 15min, and then dropwise adding the rest of the nuclear layer pre-emulsion for 1.2 h;

4) adding 14 parts of methyl methacrylate, 4 parts of isooctyl acrylate, 10 parts of butyl methacrylate, 0.5 part of gamma- (2, 3-epoxypropoxy) propyltrimethoxysilane, 0.3 part of glycidyl methacrylate, 0.8 part of a reaction type emulsifier SR-20 of Idecaco, Japan, 0.2 part of sodium persulfate, 1.5 parts of 2-amino-2-methyl-1-propanol and 20 parts of deionized water into an emulsifying cylinder I, dispersing and stirring for 28 min; adding 3 parts of methyl methacrylate, 2.5 parts of methacrylic acid, 1 part of itaconic acid, 0.3 part of alkyl polyoxyethylene ether, 0.4 part of reactive emulsifier SR-20 of Idiaceae company of Japan and 5 parts of deionized water into a second emulsifying tank, and dispersing and stirring for 28min to respectively obtain a shell layer pre-emulsion for later use;

5) after finishing dripping the nuclear layer pre-emulsion, preserving heat for 38min at 84 ℃, then dripping the pre-emulsion in the second emulsifying cylinder into the first emulsifying cylinder through a pump for 1h, dripping the mixed pre-emulsion in the first emulsifying cylinder into the reaction kettle for 1.8h, and preserving heat for 0.8h at 84 ℃ after finishing dripping;

6) after the temperature is reduced to 50 ℃, 2.5 parts of ammonia water is added to adjust the pH value of the emulsion, then 3 parts of propylene glycol phenyl ether is slowly added, the temperature is kept at 50 ℃, and the mixture is stirred for 0.5 hour and then discharged.

The pure acrylic emulsion for the matte finishing surface with excellent water resistance and stain resistance, which is prepared by the method, has the viscosity within 2000CPS (3#12r) and the minimum film forming temperature of 25 ℃.

Example 4

A matte finish surface pure acrylic emulsion with excellent water resistance and stain resistance is prepared from the following raw materials in parts by weight: 30 parts of methyl methacrylate, 15 parts of isooctyl acrylate, 10 parts of butyl methacrylate, 2.5 parts of an organic silicon assistant (methacryloxypropyltrimethoxysilane), 4 parts of a crosslinking monomer (ethylene glycol dimethacrylate), 4 parts of a carboxyl functional monomer (methacrylic acid, maleic anhydride), 2.5 parts of an emulsifier (alkyl polyoxyethylene ether, lauryl alcohol ether phosphate, reactive emulsifier COPS-2 of Rodiya corporation, reactive emulsifier SR-10 of Idiaceae corporation of Japan), 0.8 part of an initiator (ammonium persulfate), 2 parts of a film-forming assistant (2,2, 4-trimethyl-1, 3-pentanediol monoisobutyrate), 4 parts of a pH regulator (ammonia water) and 65 parts of deionized water.

The preparation method of the matte finish surface pure acrylic emulsion with excellent water resistance and stain resistance comprises the following steps:

1) under the conditions of normal temperature and normal pressure, respectively adding 10 parts of methyl methacrylate, 7 parts of isooctyl acrylate, 0.7 part of methacryloxypropyltrimethoxysilane, 2 parts of ethylene glycol dimethacrylate, 0.4 part of methacrylic acid, 1 part of reactive emulsifier SR-10 of Japan Aidicco, 0.2 part of ammonium persulfate and 20 parts of deionized water into an emulsifying cylinder, and stirring and dispersing for 30min to prepare a nuclear layer pre-emulsion for later use;

2) adding 20 parts of deionized water into a reaction kettle, adding 0.2 part of alkyl polyoxyethylene ether and 0.3 part of lauryl alcohol ether phosphate, stirring, and heating to 85 ℃ for later use;

3) adding 8% of the total mass of the nuclear layer pre-emulsion prepared in the step 1) into the reaction kettle in the step 2), adding 0.3 part of ammonium persulfate, preserving the heat at 85 ℃ for 20min, and then dropwise adding the rest of the nuclear layer pre-emulsion for 2 h;

4) adding 15 parts of methyl methacrylate, 8 parts of isooctyl acrylate, 10 parts of butyl methacrylate, 1.8 parts of methacryloxypropyltrimethoxysilane, 2 parts of ethylene glycol dimethacrylate, 0.5 part of reactive emulsifier SR-10 of Japan Aidic corporation, 0.3 part of ammonium persulfate, 1.5 parts of pH ammonia water and 20 parts of deionized water into an emulsion cylinder for dispersing and stirring for 35 min; adding 5 parts of methyl methacrylate, 2.6 parts of methacrylic acid, 1 part of maleic anhydride, 0.2 part of SR-10, 0.3 part of COPS-2 and 5 parts of deionized water, which are reactive emulsifiers of the company Idika, into a second emulsifying tank, and dispersing and stirring for 35min to respectively obtain a shell layer pre-emulsion for later use;

5) after finishing dripping the nuclear layer pre-emulsion, preserving heat for 45min at 85 ℃, then dripping the pre-emulsion in the second emulsifying cylinder into the first emulsifying cylinder through a pump for 2h, dripping the mixed pre-emulsion in the first emulsifying cylinder into the reaction kettle for 1.5h, and preserving heat for 1h at 85 ℃ after finishing dripping;

6) after the temperature is reduced to 50 ℃, 2.5 parts of ammonia water is added to adjust the pH value of the emulsion, 2 parts of 2,2, 4-trimethyl-1, 3-pentanediol monoisobutyrate is slowly added, the temperature is kept at 50 ℃, and the mixture is stirred for 0.5 hour and then discharged.

The pure acrylic emulsion for the matte finishing surface with excellent water resistance and stain resistance, which is prepared by the method, has the viscosity within 2000CPS (3#12r) and the minimum film forming temperature of 20 ℃.

Example 5

A matte finish surface pure acrylic emulsion with excellent water resistance and stain resistance is prepared from the following raw materials in parts by weight: 25 parts of methyl methacrylate, 7 parts of isooctyl acrylate, 10 parts of butyl methacrylate, 2 parts of an organic silicon assistant (vinyl trimethoxy silane), 2 parts of a crosslinking monomer (acrylamide and ethylene glycol dimethacrylate), 3 parts of a carboxyl functional monomer (methacrylic acid), 1 part of an emulsifier (sodium dodecyl sulfate, alkyl polyoxyethylene ether, lauryl alcohol ether phosphate and a reactive emulsifier SR-10 of Japan Aidicco), 0.8 part of an initiator (potassium persulfate), 3 parts of a film forming assistant (2,2, 4-trimethyl-1, 3-pentanediol monoisobutyrate), 3.5 parts of a pH regulator (ammonia water) and 60 parts of deionized water.

The preparation method of the matte finish surface pure acrylic emulsion with excellent water resistance and stain resistance comprises the following steps:

1) under the conditions of normal temperature and normal pressure, respectively adding 8 parts of methyl methacrylate, 4 parts of isooctyl acrylate, 0.5 part of vinyl trimethoxy silane, 0.5 part of acrylamide, 0.2 part of methacrylic acid, 0.2 part of lauryl alcohol ether phosphate, 0.2 part of potassium persulfate and 15 parts of deionized water into an emulsifying cylinder, and stirring and dispersing for 30min to prepare a nuclear layer pre-emulsion for later use;

2) adding 30 parts of deionized water into a reaction kettle, adding 0.1 part of sodium dodecyl sulfate and 0.1 part of alkyl polyoxyethylene ether, stirring, and heating to 86 ℃ for later use;

3) adding 10% of the total mass of the nuclear layer pre-emulsion prepared in the step 1) into the reaction kettle in the step 2), adding 0.2 part of potassium persulfate, preserving the temperature at 86 ℃ for 20min, and then dropwise adding the rest of the nuclear layer pre-emulsion for 2 h;

4) adding 13 parts of methyl methacrylate, 3 parts of isooctyl acrylate, 10 parts of butyl methacrylate, 1.5 parts of vinyl trimethoxy silane, 1.5 parts of ethylene glycol dimethacrylate, 0.3 part of a reaction type emulsifier SR-10 of Idiaceae company, 0.4 part of potassium persulfate, 1 part of ammonia water and 12 parts of deionized water into an emulsifying cylinder for dispersing and stirring for 35 min; adding 4 parts of methyl methacrylate, 2.8 parts of methacrylic acid, 0.3 part of reactive emulsifier SR-10 of Japan Edaceae and 3 parts of deionized water into a second emulsifying tank, and dispersing and stirring for 35min to respectively obtain a shell layer pre-emulsion for later use;

5) after finishing dripping the nuclear layer pre-emulsion, preserving heat for 45min at 86 ℃, then dripping the pre-emulsion in the second emulsifying cylinder into the first emulsifying cylinder through a pump for 2h, dripping the mixed pre-emulsion in the first emulsifying cylinder into the reaction kettle for 2.5h, and preserving heat for 1.5h at 86 ℃ after finishing dripping;

6) after the temperature is reduced to 50 ℃, 2.5 parts of ammonia water is added to adjust the pH value of the emulsion, then 3 parts of 2,2, 4-trimethyl-1, 3-pentanediol monoisobutyrate is slowly added, the temperature is kept at 50 ℃, and the mixture is stirred for 0.5 hour and then discharged.

The pure acrylic emulsion for the matte finishing surface with excellent water resistance and stain resistance, which is prepared by the method, has the viscosity within 2000CPS (3#12r) and the minimum film forming temperature of 25 ℃.

The emulsions obtained in examples 1 to 5 were formulated into water-borne matt top varnishes according to the following formulation Table 1.

TABLE 1 formulation of aqueous matte top varnish

Raw materials	Weight/% of
		Emulsions of the invention	50
Water (W)	44.7
		Bactericide	0.1
Film forming aid	4
		Antifreezing agent	0.5
pH regulator	0.2
		Thickening agent	0.5

The detection method comprises the following steps: the method is carried out according to the standard of the finishing varnish for HB/T5065-2016 architectural coatings, the stain resistance adopts a B method (the lower the reduction rate coefficient is, the better the performance is), and the water resistance and the water white resistance are all tested on a multi-color paint base material to observe whether the surface of the base material bubbles or discolors.

The test results are shown in table 2:

TABLE 2 test results of aqueous pure acrylic matt finish varnish

The above results show that: compared with the commercial products, the water-based pure acrylic matte finishing varnish has more excellent stain resistance, water resistance and water-white resistance, and is completely suitable for being used as the exterior wall matte finishing varnish.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents or improvements made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (9)

1. The matte finish surface pure acrylic emulsion with excellent water resistance and stain resistance is characterized by being prepared from the following raw materials in parts by weight: 15-30 parts of methyl methacrylate, 5-15 parts of isooctyl acrylate, 10-15 parts of butyl methacrylate, 1-3 parts of an organic silicon assistant, 0.5-5 parts of a crosslinking monomer, 2-4 parts of a carboxyl functional monomer, 1-3 parts of an emulsifier, 0.5-1 part of an initiator, 1-5 parts of a film-forming assistant, 1-5 parts of a pH regulator and 55-65 parts of deionized water.

2. The matte finish pure acrylic emulsion with excellent water and stain resistance of claim 1, wherein the organosilicon assistant is one or more of vinyltrimethoxysilane, vinyltriethoxysilane, methacryloxypropyltrimethoxysilane, vinyltris (β -methoxyethoxy) silane and gamma- (2, 3-glycidoxy) propyltrimethoxysilane.

3. The matte finishing acrylic emulsion with excellent water resistance and stain resistance as claimed in claim 1, wherein the crosslinking monomer is one or more of acrylamide, glycidyl methacrylate, ethylene glycol dimethacrylate and hydroxyethyl methacrylate.

4. The matte finish acrylic emulsion with excellent water resistance and stain resistance as claimed in claim 1, wherein the carboxyl functional monomer is one or more of acrylic acid, methacrylic acid, itaconic acid and maleic anhydride.

5. The matte finish surface pure acrylic emulsion with excellent water resistance and stain resistance as claimed in claim 1, wherein the emulsifier is one or more of sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, alkyl polyoxyethylene ether, sodium vinyl sulfonate, lauryl alcohol ether phosphate, reactive emulsifiers COPS-1, COPS-2, reactive emulsifiers SR-10 and SR-20.

6. The matte finishing acrylic emulsion with excellent water resistance and stain resistance as claimed in claim 1, wherein the initiator is one or more of ammonium persulfate, potassium persulfate and sodium persulfate.

7. The matte finishing acrylic emulsion with excellent water and stain resistance as claimed in claim 1, wherein the film forming aid is one or more of 2,2, 4-trimethyl-1, 3-pentanediol monoisobutyrate, propylene glycol phenyl ether, propylene glycol butyl ether and OE-300.

8. The matte finish surface pure acrylic emulsion with excellent water resistance and stain resistance as claimed in claim 1, wherein the pH regulator is one or more of ammonia water, sodium hydroxide and 2-amino-2-methyl-1-propanol.

9. A method for preparing the pure acrylic emulsion with the matte finish surface and the excellent water resistance and stain resistance of any one of claims 1 to 8, which is characterized by comprising the following steps:

1) under the conditions of normal temperature and normal pressure, respectively adding 5-10 parts of methyl methacrylate, 3-7 parts of isooctyl acrylate, 0.5-1 part of organic silicon assistant, 0.2-2 parts of crosslinking monomer, 0.2-0.5 part of carboxyl functional monomer, 0.2-1 part of emulsifier, 0.1-0.3 part of initiator and 10-20 parts of deionized water into an emulsifying cylinder, and stirring and dispersing to prepare a nuclear layer pre-emulsion for later use;

2) adding 20-30 parts of deionized water into a reaction kettle, adding 0.2-0.5 part of emulsifier, stirring, and heating to 81-86 ℃ for later use;

3) adding 1-10% of the total mass of the nuclear layer pre-emulsion prepared in the step 1) into the reaction kettle in the step 2), adding 0.2-0.3 of initiator, preserving the temperature at 81-86 ℃ for 10-20min, and then dropwise adding the rest nuclear layer pre-emulsion for 1-2 h;

4) adding 9-15 parts of methyl methacrylate, the balance of isooctyl acrylate, the formula amount of butyl methacrylate, the balance of organosilicon auxiliary agent, the balance of crosslinking monomer, 0.2-0.8 part of emulsifier, the balance of initiator, 0.5-1.5 parts of pH regulator and 12-20 parts of deionized water into an emulsion cylinder I, and dispersing and stirring for 25-35 min; adding the balance of methyl methacrylate, the balance of carboxylic acid functional monomers, the balance of emulsifying agents and the balance of deionized water into a second emulsifying cylinder, and dispersing and stirring for 25-35min to respectively obtain a shell layer pre-emulsion for later use;

5) after finishing dripping the nuclear layer pre-emulsion, preserving heat for 35-45min at the temperature of 81-86 ℃, then dripping the pre-emulsion in the first emulsifying cylinder by a pump into the first emulsifying cylinder for 1-2h, simultaneously dripping the mixed pre-emulsion in the first emulsifying cylinder into a reaction kettle for 1.5-2.5h, and preserving heat for 0.5-1.5h at the temperature of 81-86 ℃ after finishing dripping;

6) cooling to 50 ℃, adding the rest of pH regulator, regulating the pH value of the emulsion, slowly adding the film-forming assistant in the formula amount, keeping the temperature at 50 ℃, stirring for 0.5 hour, and discharging.