CN100451042C - Fluoride core-shell acrylic-resin emulsion, its production and use - Google Patents

Abstract

An acrylate emulsion containing fluorine nuclear shell, its production and use are disclosed. The process is carried out by reacting maleic anhydride with alkyl phenolic polyethenoxy ether, regulating to indifference by sodium carbonate, copolymerizing for reactive emulsion and 2-4 kinds acrylate proportionally, adding into 2-4 kinds acrylate and methyl-acrylic dodecafluoptyl esters while polymerizing nuclear monomer, reacting for 1-4hrs and drying for 10mins. It has excellent weather-resistance, water-proof and anti-fouling performances and costs low.

Description

Fluorine-containing core-shell acrylate emulsion and its preparation method and application

technical field

The invention belongs to the technical field of macromolecule chemistry, and in particular relates to a fluorine-containing core-shell emulsion for preparing water-based coatings and a preparation method thereof.

Background technique

In recent years, driven by the industrial development principles of energy saving, capital saving and low pollution, the research and development of water-based emulsion coatings has attracted increasing attention, because water-based emulsion coatings have the advantages of convenient construction, less pollution, and good stain resistance.

JP99-05951 and JP04,164,990 (1992) respectively prepared water-based fluororesins using fluorine emulsifiers. CN1566234A discloses a water-based fluorine coating prepared by combining VDF/TEF/HFP terpolymer emulsion and polyacrylate emulsion. The curing temperature is 120-130°C, and it has excellent stain resistance and weather resistance.

The prior art close to the present invention is a method for preparing water-based fluororesin disclosed by CN1322775A and its coating. The emulsifier adopts nonylphenol polyoxyethylene ether series and flat plus surfactant series in a weight ratio of 1: 0.2～1.0 Compounding, the paint prepared with this emulsion has excellent performance. However, due to the use of small molecule emulsifiers, the water resistance and stain resistance of the coating are limited.

Most of the fluoropolymers used in the past water-based fluorine coatings are polytetrafluoroethylene, tetrafluoroethylene-hexafluoroethylene (FEP), tetrafluoroethylene-perfluoroalkyl ether (PFA), etc., and the film-forming temperature of these coatings is relatively high. , the reaction conditions are harsh, and the price is higher.

Contents of the invention

The technical problem to be solved by the present invention is to prepare a fluorine-containing core-shell acrylate emulsion with a self-made reactive emulsifier, and use the emulsion to prepare a water-based paint, so as to achieve the goals of excellent paint performance, simplified reaction conditions, and reduced production costs.

The purpose of the present invention can be achieved through the following technical solutions: firstly, a reactive emulsifier is formed by the reaction of maleic anhydride and alkylphenol polyoxyethylene ether; then the reactive emulsifier is used to prepare fluorine-containing core-shell type acrylic Ester emulsion; Finally, the emulsion, water, additives and fillers are used to prepare waterborne coatings.

A fluorine-containing core-shell acrylate emulsion of the present invention comprises a reactive emulsifier in the composition, and the core part is a copolymer of 2 to 4 kinds of acrylates including methyl methacrylate, and the mass ratio of methyl methacrylate: Other components of acrylate monomer = 1:0.4~1; the shell part is the copolymerization of 2~4 kinds of acrylate including methyl methacrylate and dodecafluoroheptyl methacrylate or hexafluorobutyl methacrylate According to the mass ratio of methyl methacrylate: other components of acrylate monomer: dodecafluoroheptyl methacrylate or hexafluorobutyl methacrylate = 1: 0.7～2.2: 0.6～1.4; The molecular formula of reactive emulsifiers is:

Wherein R=8-10, n=2-15, 18, 20; the mass ratio of core part, shell part and reactive emulsifier is 1:0.8-1.3:0.02-0.2.

Above-mentioned acrylate monomer can be methyl methacrylate, butyl acrylate, ethyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate; Said reactive emulsifier is preferably molecular formula: R=10, the reactive emulsifier of n=10, that is, the molecular formula of the best reactive emulsifier is:

The preferred fluorine-containing core-shell acrylate emulsion of the present invention is that the core part of its copolymer is a copolymer of methyl methacrylate and butyl acrylate, by mass ratio methyl methacrylate: butyl acrylate=1: 0.58～ 0.63; the shell part is a copolymer of methyl methacrylate, butyl acrylate, dodecafluoroheptyl methacrylate or hexafluorobutyl methacrylate, and the mass ratio of each component monomer is 1:1.60～1.65: 0.74～0.80.

The preferred fluorine-containing core-shell acrylate emulsion of the present invention also has the core part of its copolymer being a copolymer of methyl methacrylate, ethyl methacrylate, butyl methacrylate and butyl acrylate, and each component is The mass ratio of the body is 1:0.8～0.9:0.9～1:0.6～0.7; the shell part is methyl methacrylate, ethyl methacrylate, butyl methacrylate, butyl acrylate and dodecafluoromethacrylate For the copolymer of heptyl ester or hexafluorobutyl methacrylate, the mass ratio of monomers in each component is 1:0.9-1.1:0.7-0.8:1.4-1.6:0.7-0.8.

The properties of the fluorine-containing core-shell acrylate emulsion of the present invention are shown in Table 1.

Table 1

The aforementioned reactive emulsifier is prepared by reacting maleic anhydride and alkylphenol polyoxyethylene ether. Alkylphenol-based polyoxyethylene ethers may be existing products code-named OP-2 to OP-15, OP-18, OP-20, and the like.

Using the self-made reactive emulsifier of the present invention, the polymerized fluorine-containing core-shell acrylate emulsion has excellent stability, and is superior to existing emulsifiers in terms of storage stability, electrolyte resistance stability, and centrifugal stability. fluoride emulsion. Table 2 shows the stability comparison of the fluorine-containing core-shell emulsion prepared with the reactive emulsifier of the present invention and the fluorine-containing emulsion prepared with the prior art MS-1 emulsifier.

In Table 2, the centrifugal sedimentation rate is the result of centrifugation at 8000 rpm for 120 minutes; the electrolyte precipitation resistance rate is the result of adding 5% Na ₂ SO ₄ and storing it for 72 hours.

Table 2

The preparation method of the fluorine-containing core-shell acrylate emulsion of the present invention is divided into two steps: the preparation of a reactive emulsifier and the preparation of a fluorine-containing emulsion; the preparation of said reactive emulsifier is made of maleic anhydride and alkylphenol-based poly Oxyethylene ether is reacted at a molar ratio of 1:1, and then adjusted to neutrality by sodium carbonate; the preparation of the fluorine-containing emulsion is a reactive emulsifier and methyl methacrylate and other 1 to 3 kinds of acrylate monomers Proportional copolymerization to form a nucleus, when the core monomer is polymerized to 80-90%, then add methyl methacrylate and other 1-3 kinds of acrylate monomers and dodecafluoroheptyl methacrylate or hexafluoromethacrylate in proportion Butyl ester, continue to react for 1 to 4 hours to form a shell.

Said proportionate copolymerization to form a nucleus, the raw material and its mass ratio are methyl methacrylate: other components of acrylate monomer: reactive emulsifier = 1: 0.4～1: 0.03～0.4; said formation shell , The raw material and its mass ratio are methyl methacrylate: other components of acrylate monomer: dodecafluoroheptyl methacrylate or hexafluorobutyl methacrylate=1:0.7～2.2:0.6～1.4. That is, the mass ratio of each raw material is the same as the composition ratio of the fluorine-containing core-shell acrylate emulsion.

The prepared fluorine-containing core-shell acrylate emulsion is detected by DSC glass transition temperature and transmission electron microscope, which shows that the product is of core-shell type with a particle size of about 100nm.

In the water-based paint prepared with fluorine-containing core-shell acrylate emulsion, water, additives and fillers, the emulsion component is 20-40%, the filler component is 40-50%, the additive component is 0.3-1%, and the rest for water. The filler components and auxiliary components are basically the same as the prior art.

In the auxiliary component of the water-based paint of the present invention, the thickener is one or more of hydroxyethyl cellulose (HEC), acrylic thickener (HEUR) and polyurethane associative thickener (HASE). mixture. The thickeners HEC and HEUR are aqueous solutions, and HASE is an organic solution.

In the additive component of the water-based paint of the present invention, the film-forming agent is ethylene glycol butyl ether, propylene glycol methyl ether acetate, propylene glycol propyl ether, propylene glycol butyl ether, dipropylene glycol methyl ether, and the like. The wetting agent is ethylene glycol or propylene glycol or the like. The defoaming agent is polyurethane, vinyl acetate copolymer, and the like. The dispersant is 2-amino-2-methyl-1-propanol.

The preparation method of the water-based paint of the present invention is substantially the same as the prior art. In the preparation, the color paste is a water-soluble filler, such as heavy calcium carbonate, titanium dioxide, lithopone, aluminum silicate, bentonite, iron oxide, mica, talc, dissolved in water and added with dispersant 2-amino- 2-Methyl-1-propanol (AMP-95), mixed with anti-mold fungicide and defoamer, mixed and ground into a slurry. The fineness of the color paste is ≤15μm, the viscosity is 30-35S, and the solid content is 40-50%.

Table 3 is the water-based paint prepared by the present invention and the performance test results of the coating film.

table 3

Solid content (%) 40～50 Fineness (μm) 15 Coating Appearance smooth Drying temperature, ℃ 10～40 Artificial aging resistance, 2500h No differentiation, no discoloration Alkali resistance (5% NaOH), 480h No abnormality Acid resistance (5% HCl), 48h No abnormality Salt tolerance (5% NaCl), 48h The paint film is rusty and non-foaming Washability (times), not less than 10000

The water-based paint prepared by the invention does not need to add a curing agent during use, and the drying time is 10 minutes at normal temperature, and has excellent weather resistance, water resistance, stain resistance, flexibility and high smoothness.

The invention uses copolymers such as dodecafluoroheptyl methacrylate, butyl acrylate, methyl methacrylate, etc. and a reactive emulsifier to prepare the water-based fluororesin. Acrylic coatings have the advantages of good flexibility, high smoothness, high hydrophobicity, and low film-forming temperature. Due to the use of reactive emulsifiers, the emulsifier molecules are copolymerized into the polymer chain, which avoids the hydrophobicity, The disadvantage of oily decline is that only the shell contains fluorine, which greatly reduces the cost of producing paint under the condition of slightly reducing the performance of the paint.

Detailed ways

The preparation of embodiment 1 reactive emulsifier

Take 4.75Kg of maleic anhydride and 3Kg of OP-10, a kind of alkylphenol-based polyoxyethylene ether, mix and react at 70-130°C for 4-6 hours, then add sodium carbonate to adjust the pH value to 6 ~7, to prepare a reactive emulsifier. The molecular formula of the reactive emulsifier is:

Reactive emulsifiers can also be prepared by replacing OP-10 with other alkylphenol-based polyoxyethylene ethers, such as OP-2~OP-15, OP-18, OP-20, etc. The molecular structure of reactive emulsifier and the effect of preparing fluorine-containing core-shell acrylate emulsion are roughly the same as that of OP-10.

In the preparation, the alkylphenol polyoxyethylene ether with better effect is nonylphenol polyoxyethylene ether (OP-10).

Embodiment 2 Preparation of fluorine-containing core-shell acrylate emulsion

The preparation method of fluorine-containing core-shell acrylate emulsion is divided into two steps: preparation of reactive emulsifier and preparation of fluorine-containing emulsion.

See Example 1 for the preparation of the reactive emulsifier.

Preparation of fluorine-containing emulsion: Take 0.5Kg of reactive emulsifier, 13Kg of methyl methacrylate and 8Kg of butyl acrylate to form a nucleus, and test the conversion rate in the reaction. When the nucleus monomer is polymerized to about 85%, add methyl 8Kg of methyl acrylate, 13Kg of butyl acrylate and 6Kg of dodecafluoroheptyl methacrylate continued to react for 2 hours to form a shell outside the core.

Example 3 Preparation of fluorine-containing core-shell acrylate emulsion

See Example 1 for the preparation of the reactive emulsifier.

Preparation of fluorine-containing emulsion: Take 0.5Kg of reactive emulsifier, add 6.5Kg of methyl methacrylate, 4Kg of butyl acrylate, 5.5Kg of ethyl methacrylate, and 6Kg of butyl methacrylate to copolymerize four kinds of acrylate monomers The reaction forms a nucleus. Test the conversion rate in the reaction. When the polymerization of the core monomer is equal to or greater than 80%, add 4Kg of methyl methacrylate, 6Kg of butyl acrylate, 4Kg of ethyl methacrylate, 3Kg of butyl methacrylate and methyl Dodecafluoroheptyl acrylate is 3Kg, and five monomers are copolymerized to form a shell outside the core, and the reaction time is about 4 hours.

The effect of preparing the fluorine-containing core-shell acrylate emulsion is basically the same as that of Example 2.

Example 4 Preparation of fluorine-containing core-shell acrylate emulsion

See Example 1 for the preparation of the reactive emulsifier.

Take 3Kg of reactive emulsifier, 13Kg of methyl methacrylate and 7Kg of ethyl acrylate for copolymerization reaction to form a nucleus. When the core monomer is polymerized to 90%, 6Kg of methyl methacrylate, 13Kg of butyl acrylate and 8Kg of hexafluorobutyl methacrylate are added to react to form a shell outside the core, and the reaction time is 2 hours.

The preparation process is the same as in Example 2.

Example 5 Preparation of fluorine-containing core-shell acrylate emulsion

See Example 1 for the preparation of the reactive emulsifier.

Take 3.5Kg of reactive emulsifier, 10Kg of methyl methacrylate, 6Kg of butyl methacrylate, and 5Kg of butyl acrylate to form a nucleus. Then add 7Kg of methyl methacrylate, 13Kg of ethyl acrylate and 6Kg of dodecafluoroheptyl methacrylate to react, forming a shell outside the core.

The preparation process is the same as in Example 2.

Example 6 Preparation of fluorine-containing core-shell acrylate emulsion

See Example 1 for the preparation of the reactive emulsifier.

Take 4Kg of reactive emulsifier, 10Kg of methyl methacrylate, 7Kg of butyl acrylate, and 4Kg of butyl methacrylate for copolymerization to form a nucleus. Then add 6Kg of methyl methacrylate, 12Kg of butyl acrylate and 8Kg of dodecafluoroheptyl methacrylate to react, forming a shell outside the core.

The preparation process is the same as in Example 2.

Example 7 Preparation of fluorine-containing core-shell acrylate emulsion

See Example 1 for the preparation of the reactive emulsifier.

Take 3.5Kg of reactive emulsifier, 10Kg of methyl methacrylate, 6Kg of butyl acrylate, and 5Kg of ethyl methacrylate to form a nucleus. Then add 7Kg of methyl methacrylate, 10Kg of butyl methacrylate and 8Kg of dodecafluoroheptyl methacrylate to react, forming a shell outside the core.

The preparation process is the same as in Example 2.

In the above examples 2-7, in the process of forming the shell, the amount of methyl methacrylate and other acrylate monomers and dodecafluoroheptyl methacrylate or hexafluorobutyl methacrylate added , only affects the thickness of the shell, and at the same time determines the amount of fluorine in the core-shell acrylate emulsion. As long as the mass ratio of the core part, the shell part and the reactive emulsifier is in the range of 1:1-20:0.1-0.5, the core-shell acrylate emulsion of the present invention can be obtained.

The preparation of embodiment 8 water-based fluorine coatings

By mass, disperse 27.41 parts of water, 0.65 parts of dispersant (commercially available products containing emulsifiers such as polyethoxy nonyl ethers), 0.11 parts of wetting agent (ethylene glycol or propylene glycol, etc.), and 0.17 parts of thickener After uniform dispersion, put in 8.65 parts of heavy calcium carbonate, 7.71 parts of talcum powder, 5.8 parts of mica, 10.90 parts of titanium dioxide, 2 parts of lithopone, 2.58 parts of aluminum silicate, 1.63 parts of bentonite, 1.37 parts of iron oxide, and stir After uniformity, it is sanded in a sand mill to obtain a white slurry.

According to the quality, take 25.81 parts of fluorine-containing acrylate emulsion, 0.56 parts of defoamer (such as polyurethane, vinyl acetate copolymer, etc.), 1.72 parts of film-forming aids (such as propylene glycol propyl ether, propylene glycol butyl ether, dipropylene glycol methyl ether, etc. ), 1.29 parts of thickener (HEUR), 0.22 parts of leveling agent (1,2 propylene glycol), 0.11 parts of multifunctional additives are put into white pulp, and a small amount of bactericide and preservative. Stir evenly, and filter to obtain the finished water-based fluorine paint.

The preparation of embodiment 9 waterborne fluorine paint

The preparation of color paste is the same as that in Example 8. According to the mass ratio, take 35 parts of fluorine-containing acrylate emulsion, 0.56 parts of defoamer, 1.72 parts of film-forming aid, 1.29 parts of thickener, 0.22 part of leveling agent, and 0.11 part of multifunctional The additives are put into the white slurry, a small amount of bactericide and preservative are stirred evenly, and the finished water-based fluorine paint is obtained by filtration.

The preparation of embodiment 10 waterborne fluorine paint

The preparation of the color paste is the same as in Example 8. According to the mass ratio, take 30 parts of fluorine-containing acrylate emulsion, 0.56 parts of defoamer, 1.72 parts of film-forming aid, 1.29 parts of thickener, 0.22 part of leveling agent, and 0.11 part of multifunctional Add additives, fungicides and preservatives into the white slurry, stir evenly, and filter to obtain the finished water-based fluorine coating.

The preparation of embodiment 11 water-based fluorine coatings

The preparation of the color paste is the same as in Example 8. According to the mass ratio, take 40 parts of fluorine-containing acrylate emulsion, 0.56 part of defoamer, 1.72 part of film-forming aid, 1.29 part of thickener, 0.22 part of leveling agent, and 0.11 part of multifunctional Add additives, fungicides and preservatives into the white slurry, stir evenly, and filter to obtain the finished water-based fluorine coating.

The water-based paints prepared in the above Examples 8-11 were coated on the standard sample sheet, baked at 120° C. for 10 minutes, and the properties of the coating film were tested as shown in Table 4 after cooling.

Table 4

Claims (7)

1, a kind of fluorine-containing core-shell acrylic-resin emulsion, comprise reactive emulsifier in the composition, it is characterized in that nuclear part is the multipolymer that comprises 2～4 kinds of acrylate of methyl methacrylate, by quality than methyl methacrylate: other each part acrylic ester monomer=1: 0.4～1; Shell partly is to comprise 2～4 kinds of acrylate of methyl methacrylate and the multipolymer of methacrylic acid ten difluoro heptyl esters or methacrylic acid hexafluoro butyl ester, by quality than methyl methacrylate: other each part acrylic ester monomers: methacrylic acid ten difluoro heptyl esters or methacrylic acid hexafluoro butyl ester=1: 0.7～2.2: 0.6～1.4; The molecular formula of said reactive emulsifier is:

R=8～10 wherein, n=2～15,18,20; The mass ratio of nuclear part, shell part and reactive emulsifier is 1: 0.8～1.3: 0.02～0.2.

According to the described fluorine-containing core-shell acrylic-resin emulsion of claim 1, it is characterized in that 2, said acrylate is methyl methacrylate, butyl acrylate, Jia Jibingxisuanyizhi, butyl methacrylate, ethyl propenoate; The molecular formula of said reactive emulsifier is:

3, according to claim 1 or 2 described fluorine-containing core-shell acrylic-resin emulsions, it is characterized in that, the nuclear of this emulsion copolymers partly is the multipolymer of methyl methacrylate and butyl acrylate, by quality than methyl methacrylate: butyl acrylate=1: 0.58～0.63; Shell partly is the multipolymer of methyl methacrylate, butyl acrylate and methacrylic acid ten difluoro heptyl esters or methacrylic acid hexafluoro butyl ester, and the mass ratio of each constituent monomers is 1: 1.60～1.65: 0.74～0.80.

4, according to claim 1 or 2 described fluorine-containing core-shell acrylic-resin emulsions, it is characterized in that, the nuclear of this emulsion copolymers partly is the multipolymer of methyl methacrylate, Jia Jibingxisuanyizhi, butyl methacrylate and butyl acrylate, and the mass ratio of each constituent monomers is 1: 0.8～0.9: 0.9～1: 0.6～0.7; Shell partly is the multipolymer of methyl methacrylate, Jia Jibingxisuanyizhi, butyl methacrylate, butyl acrylate and methacrylic acid ten difluoro heptyl esters or methacrylic acid hexafluoro butyl ester, and the mass ratio of each constituent monomers is 1: 0.9～1.1: 0.7～0.8: 1.4～1.6: 0.7～0.8.

5, according to claim 1 or 2 described fluorine-containing core-shell acrylic-resin emulsions, it is characterized in that, said fluorine-containing core-shell acrylic-resin emulsion, the pH value is 6～7; Proportion is 1.03～1.05g/cm ³Granularity is 90～110nm.

6, a kind of preparation method of fluorine-containing core-shell acrylic-resin emulsion of claim 1 is characterized in that, divides reactive emulsifier preparation and fluorine-containing latex to prepare two steps; Said reactive emulsifier preparation is by MALEIC ANHYDRIDE and the reaction in 1: 1 in molar ratio of alkyl phenolic group Soxylat A 25-7, is adjusted to neutrality through yellow soda ash again; Said fluorine-containing latex preparation, be reactive emulsifier and methyl methacrylate and other 1～3 kind of acrylate monomer copolymerization formation nuclear in proportion, at nuclear monomer polymerization 80～90% o'clock, add methyl methacrylate and other 1～3 kind of acrylate monomer and methacrylic acid ten difluoro heptyl esters or methacrylic acid hexafluoro butyl ester more in proportion, continue reaction and formed shell in 1～4 hour.

7, a kind of purposes of fluorine-containing core-shell acrylic-resin emulsion of claim 1 is characterized in that, makes water-borne coatings with fluorine-containing core-shell acrylic-resin emulsion; In the water-borne coatings, fluorine-containing core-shell acrylic-resin emulsion component is 20～40%, filler component 40～50%, and adjuvant component 0.3～1%, all the other are water.