CN100436497C - Preparation method of polyacrylate and fluorine-modified polyacrylate obtained by the method - Google Patents

Abstract

The invention discloses a preparation method of polyacrylate and fluorine-modified polyacrylate. The method comprises: 1) dripping mixed solution A or B under nitrogen protection; the mixed solution A includes acrylate monomers, A comonomer containing a perfluoroalkyl group and an initiator, the mixed liquid B includes an acrylate monomer, an acrylic monomer containing a perfluoroalkyl group and an initiator; 2) polymerization is carried out at reflux temperature; the described The perfluoroalkyl-containing comonomer is a carboxyl-containing perfluoroalkyl-containing comonomer, and/or, the mixed solution A includes sulfonic acid monomers, phosphonic acid monomers, and phosphonate monomers . Organic carboxylic acid monomers; the mixed solution B includes sulfonic acid monomers, phosphonic acid monomers, phosphonate ester monomers, and organic carboxylic acid monomers. The fluorine-modified polyacrylate of the present invention has good weather resistance, self-cleaning property, and chemical corrosion resistance, does not affect the adhesion between coating layers, can significantly improve the coating ability of the coating, and can be used as a base material resin. Wet paint.

Description

Preparation method of polyacrylate and fluorine-modified polyacrylate obtained by the method

technical field

The invention relates to a preparation method of polyacrylate and fluorine-modified polyacrylate obtained by the method.

Background technique

In recent years, research on fluororesin coatings has been in full swing. PTFE has excellent weather resistance, high temperature resistance, self-cleaning property, and chemical corrosion resistance, but it is not widely used as a coating due to its high price and high film forming temperature, which is not convenient for construction. Many researchers use fluororesins to modify other polymers, trying to obtain reasonably priced coatings without reducing the excellent performance of fluorine coatings.

Like PTFE, fluoropolymer emulsion also has many excellent properties, such as outstanding weather resistance, water resistance, oil resistance, chemical corrosion resistance, etc., and can be used in construction, automobile, textile, leather finishing and other fields. Foreign patents have also reported that hydroxyacrylate or methacrylic acid is polymerized with fluorine-containing monomers, and then cured by adding fluorinated isocyanate, which can significantly improve the weather resistance and solvent resistance of the coating. The polyacrylate emulsion is simple to synthesize, low in cost, good in flexibility and adhesion, but poor in water resistance and weather resistance. Combining the characteristics of acrylic resin and fluororesin, people use fluorine-containing emulsion to modify polyacrylate emulsion to obtain a new type of resin with both excellent properties.

However, in the current prior art, due to its extremely low surface free energy, the fluorine-modified acrylate does not affect the coating effect when the substrate is polluted, but it will Affects the intercoat adhesion of the paint film.

Contents of the invention

The purpose of the present invention is to provide a method for preparing polyacrylate in order to solve the problem of unsatisfactory interlayer adhesion and pigment dispersion ability of the paint film in the prior art.

Above-mentioned purpose of the present invention is achieved by following technical scheme, and preparation method of the present invention comprises the steps:

1) Under nitrogen protection, at the reflux temperature of xylene and/or butyl acetate solvent, add the mixed solution A dropwise while stirring; wherein, the mixed solution A includes acrylate monomers, copolymers containing perfluoroalkyl groups monomers and initiators;

2) Polymerization is carried out at reflux temperature;

It is characterized in that: the mixed liquid A is any one of the following three ways:

(1) Mixed solution A comprises acrylate monomer, carboxyl-containing perfluoroalkyl-containing comonomer and initiator;

(2) Mixed solution A includes acrylate monomers, comonomers and initiators containing perfluoroalkyl groups, and also includes sulfonic acid monomers, phosphonic acid monomers, phosphonate monomers and/or organic Carboxylic acid monomers;

In mode (2), the perfluoroalkyl-containing comonomer is preferably a carboxyl-containing perfluoroalkyl-containing comonomer.

Among them, among sulfonic acid monomers, phosphonic acid monomers, phosphonate ester monomers and/or organic carboxylic acid monomers, sulfonic acid monomers are preferred. When the polyacrylate of the present invention is used as a primer, intermediate coat or top coat, the introduction of polar groups such as carbonyl groups, carboxyl groups, phosphonic acid groups and/or sulfonic acid groups will improve the interlayer adhesion of the paint film.

The perfluoroalkyl-containing comonomers described in the present invention include perfluoro-substituted monomers and non-perfluoro-substituted monomers, that is, a section of the monomer structure is a perfluoroalkyl group, and other parts Structures may not be perfluoro-substituted.

The perfluoroalkyl-containing comonomers of the present invention refer to comonomers containing active groups that can react with acrylate monomers, such as containing active groups such as double bonds; The sulfonic acid monomers, phosphonic acid monomers, phosphonate monomers and organic carboxylic acid monomers also contain such active groups that can react with acrylate monomers, preferably containing Double bond structure, such as vinyl, propenyl, butenyl and other active groups.

The perfluoroalkyl-containing acrylate monomer in the present invention is preferably CH ₂ ═C(R ₂ )COOR ₃ , wherein R ₂ is H, alkyl, alkenyl, alkynyl, cycloalkyl, aryl , heterocyclyl, etc., R ₃ is a fluorine-containing alkyl group.

In the present invention, the acrylate monomers refer to fluorine-free acrylate monomers unless otherwise specified.

The preparation method of the present invention is characterized in that the raw material monomers of the present invention contain polar groups such as carboxyl, sulfonic acid and/or phosphonic acid groups, the introduction of these polar groups will improve the interlayer adhesion of the paint film, Therefore, the content and process parameters of the raw materials of the present invention can refer to the prior art. In the mixed liquid A, acrylate monomers: comonomers containing perfluoroalkyl groups: sulfonic acid monomers, phosphonic acid monomers, phosphonate monomers and/or organic carboxylic acid monomers: The weight ratio of the initiator is preferably 60:0.1～51:0.5～10:1～5; the weight ratio of the acrylate monomer in the mixed solution A: the solvent is preferably 60:20～60; the solvent Preferably xylene, if the solvent is a mixed solvent, the weight ratio of butyl acetate in the mixed solvent to xylene can be any ratio.

In a preferred embodiment of the present invention, the sulfonic acid monomer is a C _2-12 sulfonic acid monomer, such as: R ⁴ CH=C(R ⁵ )SOOOH, R ₄ CH=C(R ₅ )R ₆ SOOOH, preferably C ₂ sulfonic acid, such as: vinyl sulfonic acid (CH ₂ =CHSOOOH); the phosphonic acid monomer is a C _2-12 phosphonic acid monomer, such as: R ⁷ CH=C( R ⁸ )PO(OH) ₂ , R ₇ CH═C(R ₈ )R ₉ PO(OH) ₂ , preferably C ₂ phosphonic acid, such as: vinylphosphonic acid (CH ₂ ═CHPO(OH) ₂ ); the Phosphonate monomers are C _2-12 phosphonate monomers, such as: R ¹⁰ CH=C(R ¹¹ )OPO(OH) ₂ , R ₁₀ CH=C(R ₁₁ )R ₁₂ OPO(OH) ) ₂ , preferably C ₂ phosphonate, such as: vinyl phosphonate (CH ₂ =CHOPO(OH) ₂ ); the organic carboxylic acid monomer is a C _3-13 organic carboxylic acid monomer, such as: R ¹³ CH═C(R ¹⁴ )COOH, R ₁₃ CH═C(R ₁₄ )R ₁₅ COOH, preferably C _3-4 organic carboxylic acid, such as: acrylic acid, methacrylic acid; wherein, the above-mentioned R ⁴ , R ⁵ , R ⁷ , R ⁸ , R ¹⁰ , R ¹¹ , R ¹³ , R ¹⁴ , R ₄ , R ₅ , R ₇ , R ₈ , R ₁₀ , R ₁₁ , R ₁₃ , R ₁₄ can be various groups, such as H , alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heterocyclic, hydroxyl, amido, etc., preferably H and alkyl; R ₆ , R ₉ , R ₁₂ , R ₁₅ can be various groups Groups such as alkylene, alkenylene, alkynylene, cycloalkylene, arylene, heterocyclylene, etc., preferably alkylene.

In another preferred embodiment of the present invention:

In mode (2), the described perfluoroalkyl-containing comonomers can be various monomers known in the prior art, preferably comonomers shown in formula I or perfluoroalkyl-containing acrylates Class monomer;

式I

Formula I

Wherein, R can be a C _2-20 alkenyl group, preferably a C ₄ alkenyl group, or HOOCCH=CHCOOR ₁ -, wherein, R ₁ can be a C _1-10 alkylene group, preferably a C ₂ alkylene group; n can be 1-30, preferably 1-10, more preferably 5.

In mode (1), the carboxyl-containing perfluoroalkyl-containing comonomer is preferably a comonomer represented by formula I, and R can be HOOCCH=CHCOOR ₁ -, wherein R ₁ can be C _1-10 An alkylene group, preferably a _C2 alkylene group; n can be 1-30, preferably 1-10, more preferably 5.

The perfluoroalkyl-containing acrylate monomer is preferably a C _4-14 perfluoroalkyl-containing acrylate monomer, such as: CH ₂ =C(R ₂ )COOR ₃ , R ₂ is preferably H, C _1-5 alkyl group, R ₂ is a C _1-10 fluorine-containing alkyl group, and the perfluoroalkyl-containing acrylate monomer is more preferably trifluoromethyl acrylate (C ₄ ), methacrylic acid Dodecafluoroheptyl (C ₁₁ ), hexafluorobutyl methacrylate (C ₈ ), trifluoroethyl methacrylate (C ₆ ), dodecafluoroheptyl acrylate (C ₁₀ ) and/or nonadecane acrylate Fluorodecanyl ester (C ₁₃ ).

In another preferred embodiment of the present invention, in the polymerization reaction of step 2), supplementary dripping initiator: the weight ratio of solvent is the mixed solution C1～4 of 1～5:20～60, preferably 2 ~3, more preferably 2 times, preferably step 2) the ratio between the initiator and the solvent in the mixed solution C of replenishing drops is the same as the ratio between the initiator and the solvent used in the step 1) Consistent, that is, the weight ratio between the initiator and the solvent used in the two steps before and after is the same.

In a further preferred embodiment of the present invention, the time for adding the mixed solution in step 1) is 2 to 3 hours; the weight of the initiator in the mixed solution C added each time in step 2) is the amount initiated in step 1). 0.1～0.2 times of the weight of the agent, that is: the amount of dripping of the mixed solution C is calculated with the weight of the initiator in the mixed solution C being 0.1～0.2 times of the weight of the initiator in step 1), and the time for each supplementary drop is 5～ 20 minutes, preferably 10 minutes, supplemented every 1 to 1.5 hours.

The mixed liquid A of the present invention can also include other comonomers that can participate in copolymerization with acrylates in the prior art, such as styrene; the acrylate monomers can be various acrylates in the prior art monomers, preferably ethyl acrylate, butyl acrylate, isooctyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, methyl methacrylate, butyl methacrylate, hydroxyethyl methacrylate and/or methyl Hydroxypropyl acrylate; The initiator can be various initiators (including various peroxy initiators), preferably azobisisobutyronitrile (AIBN), benzoyl peroxide (BPO) or peroxide Di-tert-butyl (DTBP), more preferably AIBN.

The reflux temperature in step 1) is preferably 98-140° C., and the entire polymerization reaction time is preferably 5-10 hours.

Another object of the present invention is to provide the fluorine-modified polyacrylate obtained by the preparation method of the present invention.

Among them, the main chain of the fluorine-modified polyacrylate of the present invention is acrylate, which may also contain structures such as styrene, and the side chains contain perfluoroalkyl groups, or part of the side chains contain perfluoroalkyl groups.

Wherein, a possible structural formula of the fluorine-modified polyacrylate of the present invention is:

Wherein, the groups R ₁₆ , R ₁₇ , and R ₁₈ themselves independently contain perfluoro or non-perfluoro alkyl groups,

For example: -R ₁₉ (CF ₂ ) _L CF ₃ , R ₁₉ can be non-perfluorinated.

The perfluoroalkyl-containing monomer part of the polyacrylate resin of the present invention accounts for 0.1% to 85% by weight of the resin monomer.

At the same time, polar groups such as carboxyl groups, carbonyl groups, phosphonic acid groups and/or sulfonic acid groups are introduced into the acrylic resin, and the content thereof accounts for 0.5%-10% by weight of the monomers. For example, using vinyl sulfonic acid as a monomer raw material can introduce sulfonic acid groups into the polyacrylate resin of the present invention, and its molecular formula is as follows:

The fluorine-modified polyacrylate resin of the present invention introduces the above-mentioned active groups, and has the following functions: A) reduce the sensitivity of the coating to the construction environment, even if there are problems such as oil stains on the surface of the construction piece, because the fluororesin has very low surface tension , the polarity is low, and there is a large trend effect when forming a film, and the fluorine-containing group extends to the air/polymer interface to avoid the generation of paint film defects such as shrinkage; B) Since the interface of the polymer coating is organic fluorine, Extremely low interfacial tension will affect the interlayer adhesion of the coating. At this time, polar groups such as carboxyl, carbonyl, phosphonic acid and/or sulfonic acid can avoid this problem and significantly improve the interlayer adhesion. The fluorine-modified acrylate resin can improve the coating ability of the coating without affecting the interlayer adhesion. At the same time, due to the presence of polar groups such as carboxyl, carbonyl, phosphonic acid and/or sulfonic acid, the pigment wetting ability of the resin can be greatly improved. Therefore, this kind of polyacrylate has the property of wetting the pigment while being used as a base resin; because fluorine has a very low surface tension, it helps the leveling of the coating film, so it can be used as a flow control aid and other surface treatment agent.

The positive progress effect of the present invention is: the fluorine-modified polyacrylate of the present invention has excellent weather resistance, high temperature resistance, self-cleaning property, and chemical corrosion resistance; and in the fluorine-modified polyacrylate resin, carboxyl, After the structure of phosphonic acid group and/or sulfonic acid group, the coating ability of the coating is significantly improved without affecting the adhesion between the coating layers, and it can be used as a flow control aid and other surface treatment agents, and it can also impart When fluorine-modified acrylate is used as the base resin, it can wet the pigment.

Detailed ways

Example 1

Compound G1 (CF ₃ (CF ₂ ) ₅ CH ₂ CH ₂ OOCCH=CHCOOH)

Add 0.1mol maleic anhydride and 0.1mol HOCH ₂ CH ₂ (CF ₂ ) ₅ CF ₃ into the reaction flask, heat to melt the maleic anhydride, add a catalytic amount of phosphoric acid as a catalyst, react at 140°C, keep warm Compound G1 was obtained in 2h.

Table 1

Add 50g of xylene into a dry four-neck flask reaction flask equipped with a stirrer, dropping funnel, condenser and thermometer, and stir and heat to 138°C under the protection of nitrogen; add the mixed solution A1 stably and uniformly, drop for 2.5 hours Complete; continue the heat preservation reaction for 1 hour; then add the mixed solution of 0.3g initiator + 6.25g xylene for 10 minutes, and continue the reaction for 1 hour; then add the mixed solution of 0.3g initiator + 6.25g xylene dropwise for 10 minutes , and continue to keep warm for 2h to obtain fluorine-modified polyacrylate.

Example 2

Table 2

Add 50g of xylene into a dry four-neck flask reaction flask equipped with a stirrer, dropping funnel, condenser and thermometer, and stir and heat to 138°C under the protection of nitrogen; add the mixed solution A2 stably and uniformly, drop for 2.5 hours Complete; continue the insulation reaction for 1 hour; then add the mixed solution of 0.5g initiator + 6.25g xylene for 10 minutes, and continue the reaction for 1 hour; add the mixed solution of 0.5g initiator + 6.25g xylene dropwise for 10 minutes , After dropping, continue to keep warm for 2h to obtain fluorine-modified polyacrylate.

Example 3

table 3

Add 20g of xylene into a dry four-neck flask reaction flask equipped with a stirrer, dropping funnel, condenser and thermometer, and under the protection of nitrogen, stir and heat to 138°C; add the mixed solution A3 stably and uniformly, and drop it for 2 hours. ;Continue the insulation reaction for 1.2h; then add the mixed solution of 0.2g initiator+4g xylene, drop it in 20min, continue the reaction for 1.2h; then add the mixed solution of 0.2g initiator+4gxylene, drop it in 20min, Continue to react for 1.2h; then add a mixture of 0.2g initiator + 4g xylene, after 20 minutes, continue to react for 1.2h; then add dropwise a mixture of 0.2g initiator + 4g xylene, after 20min, continue to keep warm After 2 hours of reaction, a fluorine-modified polyacrylate was obtained.

Example 4

Table 4

Add 60g of xylene into a dry four-necked reaction flask equipped with a stirrer, dropping funnel, condenser and thermometer, and under the protection of nitrogen, stir and heat to 138°C; drop the mixed solution A4 stably and uniformly, drop for 2.5 hours Complete; continue the heat preservation reaction for 1 hour; then supplement the mixed solution of 0.2g initiator + 6g xylene for 5 minutes, continue the reaction for 1 hour; then supplement the mixed solution of 0.2g initiator + 6g xylene for 5 minutes, continue React for 1 hour; then add a mixed solution of 0.2 g initiator + 6 g xylene for 5 minutes, and continue the heat preservation reaction for 2 hours to obtain fluorine-modified polyacrylate.

Example 5

table 5

Add 40g of xylene into a dry four-necked reaction flask equipped with a stirrer, dropping funnel, condenser and thermometer, and under the protection of nitrogen, stir and heat to 135°C; add the mixed solution A5 stably and uniformly, and drop it for 3 hours. ;Continue the heat preservation reaction for 1.5h; then add the mixed solution of 0.5g initiator + 4.0g xylene, after 20min, continue the heat preservation reaction for 2.5h to obtain fluorine-modified polyacrylate.

Example 6

Compound G2 (CF ₃ (CF ₂ ) ₁₀ CH ₂ CH ₂ OOCCH=CHCOOH)

Add 0.1mol maleic anhydride and 0.1mol perfluorodecyl ethanol (HOCH ₂ CH ₂ (CF ₂ ) ₁₀ CF ₃ ) into the reaction flask, heat to melt the maleic anhydride, add a catalytic amount of phosphoric acid as Catalyst, react at 140°C, keep warm for 2h to obtain compound G2.

Table 6

Add 28g of xylene into a dry four-necked reaction flask equipped with a stirrer, dropping funnel, condenser and thermometer, and stir and heat to 140°C under the protection of nitrogen; add the mixed solution A6 stably and uniformly, drop for 2.5 hours Complete; continue the heat preservation reaction for 1.5h; then add the mixed solution of 0.48g initiator + 5.6g xylene for 20min, and continue the reaction for 1.5h; then add dropwise the mixed solution of 0.48g initiator + 5.6g xylene for 20min After dropping, continue to keep warm for 3 hours to obtain fluorine-modified polyacrylate.

Example 7

Compound G3 (CF ₃ CF ₂ CH ₂ OOCCH=CHCOOH)

Add 0.1mol maleic anhydride and 0.1mol HOCH ₂ CF ₂ CF ₃ into the reaction flask, heat to melt the maleic anhydride, add a catalytic amount of phosphoric acid as a catalyst, react at 140°C, and keep warm for 2 hours to obtain the compound G3.

Table 7

Add 50g of butyl acetate solvent into a dry four-necked reaction flask equipped with a stirrer, dropping funnel, condenser and thermometer, and under the protection of nitrogen, stir and heat to the reflux temperature of 98°C; drop the mixed solution A7 stably and evenly , after 2 hours of dripping; continue the heat preservation reaction for 1.2 hours; then add the mixed solution of 0.36g initiator + 7.5g butyl acetate, after 13 minutes, continue the reaction for 1.2h; then add 0.36g initiator + 7.5g butyl acetate dropwise After 13 minutes of dripping, the reaction was continued for 2 hours to obtain fluorine-modified polyacrylate.

Example 8

Compound G4 (CF ₃ (CF ₂ ) ₅ (CH ₂ ) ₉ CH ₂ OOCCH=CHCOOH)

Add 0.1mol maleic anhydride and 0.1mol HOCH ₂ (CH ₂ ) ₉ (CF ₂ ) ₅ CF ₃ into the reaction flask, heat to melt the maleic anhydride, add a catalytic amount of phosphoric acid as a catalyst, and heat at 140°C React and keep warm for 2h to obtain compound G4.

Table 8

Add 50g of xylene into a dry four-necked reaction flask equipped with a stirrer, dropping funnel, condenser and thermometer, and stir and heat to 136°C under the protection of nitrogen; add the mixed solution A8 stably and uniformly, drop for 3.0h Complete; continue the heat preservation reaction for 1.3h; then add the mixed solution of 0.3g initiator + 6.25g xylene for 8min, and continue the reaction for 1.3h; then add dropwise the mixed solution of 0.3g initiator + 6.25g xylene for 8min After dropping, continue to keep warm for 2 hours to obtain fluorine-modified polyacrylate.

Example 9

Table 9

Add 50g of xylene into a dry four-neck flask reaction flask equipped with a stirrer, dropping funnel, condenser and thermometer, under the protection of nitrogen, stir and heat to 138°C, drop the mixed solution A9 stably and uniformly, drop for 2.5h Complete; continue the insulation reaction for 1 hour; then add the mixed solution of 0.3g initiator + 6.25g xylene for 10 minutes, and continue the reaction for 1 hour; add the mixed solution of 0.3g initiator + 6.25g xylene dropwise for 10 minutes , After dropping, continue to keep warm for 2h to obtain fluorine-modified polyacrylate.

Example 10

Table 10

Add 50g xylene and butyl acetate (xylene: butyl acetate weight ratio=1: 0.5) mixed solvent in the dry four-neck flask reaction flask that agitator, dropping funnel, condenser and thermometer are equipped, pass Under nitrogen protection, stir and heat to reflux temperature; Stir and evenly drop the mixed solution A10, 2.5h drop complete; Continue heat preservation reaction 1.5h; Then add 0.3g initiator+6.25g xylene and butyl acetate (xylene: acetic acid The weight ratio of butyl ester=1: 0.5) the mixed solution of mixed solvent, 15min finishes dripping, continues reaction 1.5h; Add dropwise 0.3g initiator+6.25g xylene and butyl acetate (xylene: the weight of butyl acetate Ratio = 1:0.5) mixed solution of mixed solvents, after 15 minutes of dripping, continue to keep warm for 2 hours to obtain fluorine-modified polyacrylate.

Example 11

Table 11

Add the mixed solvent of 30g dimethylbenzene and butyl acetate (xylene: the weight ratio=3: 1 of butyl acetate) in the dry four-neck flask reaction flask that agitator, dropping funnel, condenser and thermometer are equipped, Under the protection of nitrogen, stir and heat to reflux temperature; Stir and evenly add the mixed solution A11 dropwise, 2.8h to complete; Continue to keep warm for 1.4h; Then add 0.45g initiator + 4.5g xylene and butyl acetate (xylene: The weight ratio of butyl acetate=3: 1) mixed solution of the mixed solvent, 18min finishes dripping, continues reaction 1.4h; Add dropwise 0.45g initiator+4.5g xylene and butyl acetate (xylene: butyl acetate The weight ratio=3:1) of the mixed solution of the mixed solvent was dropped after 18 minutes, and the reaction was continued for 2 hours to obtain the fluorine-modified polyacrylate.

Example 12

Table 12

Add the mixed solvent of 50g dimethylbenzene and butyl acetate (xylene: the weight ratio=1: 1 of butyl acetate) in the dry four-neck flask reaction flask that agitator, dropping funnel, condenser and thermometer are equipped, Under the protection of nitrogen gas, stir and heat to reflux temperature; Stir and evenly add the mixed solution A12 dropwise, 2.3h to complete the drop; continue the heat preservation reaction for 1.1h; The weight ratio of butyl acetate=1: 1) the mixed solution of mixed solvent, 10min finishes dripping, continues reaction 1.1h; Add dropwise 0.3g initiator+6.25g dimethylbenzene and butyl acetate (xylene: the mixture of butyl acetate) Weight ratio = 1:1) mixed solution of mixed solvents, after 10 minutes of dripping, continue to keep warm for 2 hours to obtain fluorine-modified polyacrylate.

Example 13

Table 13

Add 50g of xylene into a dry four-necked reaction flask equipped with a stirrer, dropping funnel, condenser and thermometer, and under the protection of nitrogen, stir and heat to 138°C; drop the mixed solution A13 stably and uniformly, drop for 2.5 hours Complete; continue the heat preservation reaction for 1 hour; then add the mixed solution of 0.3g initiator + 6.25g xylene for 10 minutes, and continue the reaction for 1 hour; then add the mixed solution of 0.3g initiator + 6.25g xylene dropwise for 10 minutes , and continue to keep warm for 2h to obtain fluorine-modified polyacrylate.

Comparative Example 1

Table 14

Add 50g of xylene into a dry four-neck flask reaction flask equipped with a stirrer, dropping funnel, condenser and thermometer, and under the protection of nitrogen, stir and heat to 138°C; drop the mixed solution a steadily and uniformly, drop for 2.5h Complete; continue the heat preservation reaction for 1 hour; then add the mixed solution of 0.3g initiator + 6.25g xylene for 10 minutes, and continue the reaction for 1 hour; then add the mixed solution of 0.3g initiator + 6.25g xylene dropwise for 10 minutes , and continue to keep warm for 2h to obtain fluorine-modified polyacrylate.

Comparative Example 2

Table 15

Add 50g of xylene into a dry four-neck flask reaction flask equipped with a stirrer, dropping funnel, condenser and thermometer, and under the protection of nitrogen, stir and heat to 138°C; drop the mixed solution b stably and evenly, drop for 2.5h Complete; continue the heat preservation reaction for 1 hour; then add the mixed solution of 0.3g initiator + 6.25g xylene for 10 minutes, and continue the reaction for 1 hour; then add the mixed solution of 0.3g initiator + 6.25g xylene dropwise for 10 minutes , and continue to keep warm for 2h to obtain fluorine-modified polyacrylate.

Effect Example 1 Interlayer Adhesion

The paint matching experiment is carried out according to the conventional technology in the prior art, using thermoplastic polyacrylic resin as the primer, the intermediate coating is the combination of Bayer's hydroxyacrylic resin Desmophen A870 and Desmodur N75, and the topcoat is respectively Examples 1, 2 and 9 and comparative For the polyacrylate prepared in Examples 1 and 2, the detection standard is DIN 53151, and the results are shown in Table 16 below.

Table 16

The result shows: the polyacrylate containing polar groups such as phosphonic acid group, carbonyl, carboxyl and/or sulfonic acid group of the present invention, especially the polyacrylate containing sulfonic acid group as topcoat, compared with not containing polar The group of polyacrylate can significantly improve the interlayer adhesion.

Effect Example 2 Pigment Dispersion Performance

The paint matching experiment was carried out according to conventional techniques, and thermoplastic acrylic resin RohmhassB66 was added, and iron oxide red was ground for 2 hours with the polyacrylates obtained in Examples 1, 2 and 9 and Comparative Examples 1 and 2 respectively, and then according to the detection standard GB/T 1743-79 (89) tests the gloss of the paint film, and the results are shown in Table 17.

Table 17

The result shows: the polyacrylate of the present invention containing polar groups such as phosphonic acid group, carbonyl, carboxyl and/or sulfonic acid group, especially the polyacrylate containing sulfonic acid group, compared with the polyacrylate not containing polar group Polyacrylic resin can significantly improve the gloss of the paint film, which can be increased by 20-40%.

Conclusion: The fluorine-modified polyacrylate of the present invention is a high weather resistance resin, and has a strong construction environment tolerance, and can still obtain a coating film with excellent comprehensive properties when the substrate has oil stains; especially the introduction of After adding vinyl sulfonic acid, the interlayer adhesion of the fluorine-modified acrylate has been significantly improved; the fluorine-modified acrylate of the present invention can wet the pigment while serving as the base resin.

The raw materials used in the above examples are all commercially available.

Claims (13)

1, a kind of preparation method of polyacrylate, this method comprises the steps: 1) Under nitrogen protection, at the reflux temperature of xylene and/or butyl acetate solvent, add the mixed solution A dropwise while stirring; 2) carry out polymerization reaction at reflux temperature; It is characterized in that: the mixed liquid A is any one of the following two ways: (1) Mixed solution A comprises acrylate monomer, carboxyl-containing perfluoroalkyl-containing comonomer and initiator; (2) Mixed solution A includes acrylate monomers, comonomers and initiators containing perfluoroalkyl groups, and also includes sulfonic acid monomers, phosphonic acid monomers, phosphonate monomers and/or organic Carboxylic acid monomer. 2. The preparation method according to claim 1, characterized in that: in mode (2), the perfluoroalkyl-containing comonomer is a carboxyl-containing perfluoroalkyl-containing comonomer. 3. The preparation method according to claim 1, characterized in that: in the mixed solution A, acrylic monomers: comonomers containing perfluoroalkyl groups: sulfonic acid monomers, phosphonic acid monomers, Phosphonate monomer and/or organic carboxylic acid monomer: the weight ratio of initiator is 60:0.1～51:0.5～10:1～5; the acrylate monomer in the mixed solution A: the weight of solvent The ratio is 60:20-60. 4. The preparation method according to claim 1 or 3, characterized in that: the sulfonic acid monomer is a C _2-12 sulfonic acid monomer; the phosphonic acid monomer is a C _2-12 phosphonic acid class monomer; the phosphonate monomer is a C _2-12 phosphonate monomer; the organic carboxylic acid monomer is a C _3-13 organic carboxylic acid monomer. 5. The preparation method according to claim 1, characterized in that: In the mode (1), the carboxyl group-containing perfluoroalkyl-containing comonomer is a comonomer represented by formula I, wherein R is HOOCCH=CHCOOR ₁ -, wherein R ₁ is C _1-10 Alkylene group; n is 1-30; In mode (2), the comonomer containing perfluoroalkyl group is a comonomer shown in formula I or an acrylic ester monomer containing perfluoroalkyl group:

Formula I Wherein, R is a C _2-20 alkenyl group, or HOOCCH=CHCOOR ₁ -, wherein R ₁ is a C _1-10 alkylene group; n is 1-30. 6. The preparation method according to claim 5, characterized in that: the perfluoroalkyl-containing acrylate monomer is a C _4-14 perfluoroalkyl-containing acrylate monomer. 7. The preparation method according to claim 5, characterized in that n is 1-10. 8. The preparation method according to claim 6, characterized in that: the perfluoroalkyl-containing acrylate monomers are dodecafluoroheptyl methacrylate, hexafluorobutyl methacrylate, methyl Trifluoroethyl acrylate, dodecafluoroheptyl acrylate and/or nonadecafluorodecyl acrylate. 9. The preparation method according to claim 5, characterized in that: R is a C ₄ alkenyl group, or R ₁ is a C ₂ alkylene group; n is 5. 10. The preparation method according to any one of claims 1 to 3, characterized in that: in the polymerization reaction of step 2), supplementary dripping of initiator:solvent with a weight ratio of 1 to 5:20 to 60 mixed solution C1 to 4 times. 11. The preparation method according to claim 10, characterized in that: the time for adding the mixed solution A in step 1) is 2 to 3 hours; the weight of the initiator in the mixed solution C added each time in step 2) It is 0.1-0.2 times of the weight of the initiator in step 1), and the time for each supplementary drip is 5-20 minutes, and the supplementary drip is once every 1-1.5 hours. 12. The preparation method according to any one of claims 1-3, characterized in that: the mixed liquid A also includes styrene, and the acrylate monomers are ethyl acrylate, butyl acrylate, acrylic acid Isooctyl, hydroxyethyl acrylate, hydroxypropyl acrylate, methyl methacrylate, butyl methacrylate, hydroxyethyl methacrylate and/or hydroxypropyl methacrylate; the initiator is azo Diisobutyronitrile, benzoyl peroxide or di-tert-butyl peroxide; the reflux temperature of the solvent in step 1) is 98-140° C., and the entire polymerization reaction time is 5-10 hours. 13. The fluorine-modified polyacrylate obtained by the preparation method according to any one of claims 1-3.