CN106832150A - Modified Nano SiO2/ epoxy acrylate latex and its preparation method and application - Google Patents

Abstract

The invention discloses a preparation method of modified nano- _SiO2 /epoxy-acrylate latex, including the preparation of modified nano- _SiO2 and latex, and also discloses a method for preparing water-based anticorrosion paint with the latex. The present invention adopts Oleic acid modifies nano-SiO ₂ , fully mixes the modified nano-SiO ₂ , epoxy resin and acrylate, and reacts to obtain modified nano-SiO ₂ /epoxy-acrylate latex. Using modified nano-SiO ₂ /epoxy-acrylate as the film-forming material, the molar ratio of epoxy resin and acrylate is 1:1, and 0.15% NaOH is used to optimize the pH value, and a new modified nano-SiO ₂ / Epoxy-acrylate water-based anti-corrosion coating, the adhesion of the coating reaches grade 1, the impact resistance reaches 50cm, the pencil hardness reaches 2H, and it has the characteristics of good storage stability, weather resistance and excellent physical and mechanical properties.

Description

Modified nano-SiO2/epoxy-acrylate latex and its preparation method and application

technical field

The invention relates to a preparation method of a composite material, in particular to a preparation method of modified nano-SiO ₂ /epoxy-acrylate latex.

Background technique

Water-based coatings are coatings that use water as a solvent or as a dispersion medium. It has the characteristics of non-toxic, odorless, low price, and abundant resources, which can greatly reduce the pollution of the atmosphere caused by the volatilization of organic solvents in coatings, and use water as a solvent, which can greatly improve the durability of coatings during storage, transportation and construction. safety. At present, water-based anti-corrosion coatings have been successfully used in architectural decoration, automobile manufacturing, ship and container manufacturing, railway locomotives, aerospace, traffic bridges and wood coating, etc.

During the use of water-based anti-corrosion coatings, there are problems such as poor storage stability, demulsification, flocculation, and poor medium resistance. In addition, the technical difficulty in the development of water-based anti-corrosion coatings is relatively high, resulting in a low level of industrial application.

Contents of the invention

Purpose of the invention: The purpose of the present invention is to provide a kind of preparation method of modified nano- _SiO2 /epoxy-acrylate latex in order to overcome the problems of poor storage stability, demulsification, flocculation and medium resistance of water-based anticorrosion coatings.

Technical scheme: a preparation method of modified nano-SiO ₂ /epoxy-acrylate latex, comprising the following steps:

1) Preparation of modified nano-SiO ₂ : fully mix 20-30g oleic acid with 5-10g nano-SiO ₂ , add 40-50mL acetone, adjust the pH value to 8-9, and disperse with 40KHz ultrasonic wave on a high-speed homogeneous disperser Disperse for 30-50 minutes, raise the temperature to 110-120°C, and dry to obtain modified nano-SiO ₂ , which is ready for use;

2) Fully mix 18-20g epoxy resin with 2-3g modified nano-SiO ₂ , add 40-50mL acetone, 8-10g acrylate and 3-5 drops of dibutyltin dilaurate, ultrasonically disperse for 30min, and heat up to Keep warm at 90°C for 3 hours, add 10-15g of deionized water, remove acetone after full emulsification, add 3-5g of curing agent triethylenetetramine after cooling, and prepare modified nano-SiO ₂ /epoxy-acrylic acid after stirring evenly Ester latex.

Preferably, the molar ratio of epoxy resin to acrylate is 1:1.

The invention also discloses the modified nano SiO ₂ /epoxy-acrylate latex prepared by the above preparation method.

As the third object of the present invention, the application of the modified nano-SiO ₂ /epoxy-acrylate emulsion in the preparation of water-based anti-corrosion paint is also disclosed.

As the fourth object of the present invention, a water-based anti-corrosion coating is disclosed, which consists of the following components in parts by mass:

Pulping components: 1-2g wetting agent, 2-3g defoamer, 5-7g dispersant, 1-2g bactericide, 1-2g multifunctional additive, 5-8g film-forming aid, mica powder 31 ～35g, talcum powder 31～35g, iron oxide red 20～22g, zinc phosphate 75～80g, aluminum tripolyphosphate 20～23g, titanium dioxide 110～130g, ethylene glycol 21～25g, wollastonite 47～50g, hydroxyl Ethyl cellulose 1-2g, barium sulfate 130-150g, sodium hydroxide 1-2g, water 200-220g;

Paint letdown components: latex 350-360g, thickener 2-3g, leveling agent 2-3g, butyl glycol ether 5-7g, defoamer 1-2g.

As the 5th object of the present invention, disclose the preparation method of above-mentioned water-based anti-corrosion paint, comprise the following steps:

1) Preparation of anti-corrosion slurry: Take water and bactericide into the stirring tank, stir at 500r/min evenly, then add film-forming aids, ethylene glycol, dispersant, wetting agent, hydroxyethyl cellulose, defoamer and multi-functional additives, 500r/min stirring evenly to obtain a dispersion;

During the stirring process of the above dispersion liquid, slowly add zinc phosphate, aluminum tripolyphosphate, mica powder, iron oxide red, talc powder, wollastonite, titanium dioxide, barium sulfate, adjust the stirring speed to 1800-2000r/min, and disperse for 16 ~18 minutes, add sodium hydroxide to adjust the pH value to 7, grind until the particle size is less than 40um, and then get the anti-corrosion slurry, which is ready for use;

2) Paint adjustment: Slowly add the anticorrosive slurry ground in step 1) to the stirring tank, under stirring at a low speed of 400r/min, gradually add the latex, thickener, leveling agent, butyl glycol in claim 2 Ether and defoaming agent are stirred evenly to prepare the modified nano-SiO ₂ /epoxy-acrylate water-based anti-corrosion coating.

Preferably, in step 1), the mass fraction of sodium hydroxide in the anticorrosion slurry is 0.15%.

The present invention modifies nano- _SiO2 by oleic acid, fully mixes the modified nano- _SiO2 , epoxy resin and acrylate, wherein the molar ratio of epoxy resin to acrylate is 1:1, and the reaction results in Modified nano-SiO ₂ /epoxy-acrylate latex. A new type of modified nano-SiO ₂ /epoxy-acrylic acid was prepared by using modified nano-SiO ₂ /epoxy-acrylate as film-forming material, adding pigments, fillers and multifunctional additives, etc., and optimizing the pH with 0.15% NaOH Ester water-based anti-corrosion coating, the adhesion of the coating reaches grade 1, the impact resistance reaches 50cm, the pencil hardness reaches 2H, and it has the characteristics of good storage stability, weather resistance and excellent physical and mechanical properties.

detailed description

In the present invention: the types and sources of each raw material: nano-SiO ₂ , oleic acid, Nanjing Shuguang Chemical General Factory; epoxy resin (E-51), Yueyang Petrochemical Corporation; acetone (industrial grade), Xi'an Chemical Reagent Factory; film-forming Auxiliary (CS-12, industrial grade), Jiangsu Ruitai Chemical Company; Dispersant (SN-5040, industrial grade), Punuoke Company; Multifunctional additive (AMP-95, industrial grade), Hantai Chemical Company PE-100 wetting agent (PE-100), talcum powder (1250 mesh), are industrial grade, Youchang Chemical Company; Defoamer (CF-555, industrial grade), Haichuan Chemical Company; Bactericide (981 , industrial grade), Huaxia Auxiliary Company; Sodium Hydroxide (NaOH, Industrial Grade), Tianjin Pengkun Chemical Company; Zinc Phosphate (45%), Aluminum Tripolyphosphate (APZ-99), Iron Red (190), all Industrial grade, Shanghai Nuocheng Chemical Company; mica powder (800 mesh, industrial grade), Bucks Chemical Company; thickener (3116), leveling agent (3322), both industrial grade, Guanzhi Chemical Company.

Experimental equipment: ultrasonic cleaner (SK1200H type), Shanghai Kedao Ultrasonic Instrument Co., Ltd.; high-speed homogeneous disperser (FJ-200 type), Shanghai Specimen Model Factory; paint surface impact machine (QCJ type), Cangzhou Oupu Testing Instrument Ltd.

Example 1:

A preparation method of modified nano- _SiO2 /epoxy-acrylic latex, comprising the following steps:

1) Preparation of modified nano-SiO ₂ : fully mix 20g oleic acid and 5g nano-SiO ₂ , add 40ml acetone, adjust the pH value to 8, disperse on a high-speed homogeneous disperser for 30min after 40KHz ultrasonic dispersion, and raise the temperature to 110°C , and dried to prepare modified nano-SiO ₂ , which is ready for use;

2) Fully mix 18g epoxy resin with 2g modified nano-SiO ₂ , add 40mL of acetone, 8g of acrylate and 3-5 drops of dibutyltin dilaurate. Ionized water 10g, after emulsification is sufficient, remove acetone, add solidifying agent triethylenetetramine 3～5g after cooling, make modified nano- _SiO2 /epoxy-acrylate latex after stirring evenly, in the present embodiment, epoxy The molar ratio of resin to acrylate was 1:1.

In the modification process, the effect of resin selection on coating properties

The pros and cons of epoxies and acrylates are listed in Table 1. Epoxy resin and acrylate have their own advantages and disadvantages as film-forming substances. The use of acrylate-modified epoxy resin can make up for their respective shortcomings and effectively play the advantages of both. Therefore, acrylate-modified epoxy resin latex is an ideal film-forming substance for preparing water-based anti-corrosion coatings.

Table 1 Advantages and disadvantages of epoxy resin and acrylate

Adopt above-mentioned latex to prepare water-based anti-corrosion paint, be made up of each component of following mass parts:

Pulping components: 1g wetting agent, 2g defoamer, 5g dispersant, 1g bactericide, 1g multifunctional additive, 5g film-forming additive, 31g mica powder, 31g talcum powder, 20g iron oxide red, zinc phosphate 75g, aluminum tripolyphosphate 20g, titanium dioxide 110g, ethylene glycol 21g, wollastonite 47g, hydroxyethyl cellulose 1g, barium sulfate 130g, sodium hydroxide 1g, water 220g;

Paint mixing components: 350g of the above latex, 2g of thickener, 2g of leveling agent, 5g of butyl glycol ether, and 1g of defoamer.

The preparation method of above-mentioned waterborne paint, comprises the following steps:

1) Preparation of anti-corrosion slurry: Take water and bactericide into the stirring tank, stir at 500r/min evenly, then add film-forming aids, ethylene glycol, dispersant, wetting agent, hydroxyethyl cellulose, defoamer and multi-functional additives, stir evenly at 500r/min;

During the stirring process of the above dispersion liquid, slowly add zinc phosphate, aluminum tripolyphosphate, mica powder, iron oxide red, talc powder, wollastonite, titanium dioxide, barium sulfate, adjust the stirring speed to 1800-2000r/min, and disperse for 16 ~18 minutes, add sodium hydroxide to adjust the pH value to 7, grind until the particle size is less than 40um, and then get the anti-corrosion slurry, which is ready for use;

2) Paint adjustment: Slowly add the anti-corrosion slurry ground in step 1) to the stirring tank, and gradually add the above-mentioned latex, thickener, leveling agent, butyl glycol ether and defoaming agent under 400r/min low-speed stirring agent, and stir evenly to prepare the modified nano-SiO ₂ /epoxy-acrylate water-based anti-corrosion coating.

In this embodiment, in step 1), the mass fraction of sodium hydroxide in the anticorrosion slurry is 0.15%.

The Effect of pH Value on the Stability of Coatings

Since the prepared slurry is highly acidic, NaOH must be used to neutralize the slurry during the pulping process, otherwise, the acidic slurry will easily react with the alkaline latex during the preparation of the water-based paint. Affect the dispersion state of each component in the water-based paint, and cause unstable phenomena such as demulsification and hardening.

The effect of NaOH content on the stability of coatings is shown in Table 2. It can be seen from Table 2 that when the amount of NaOH added is 0.15% (wt, mass fraction, the same below), the stability of the coating is the best. Too low NaOH addition will lead to demulsification, stickiness and hardening of the paint, too much NaOH is not necessary but also increases the corrosion of alkali to metal.

Table 2 Effect of NaOH dosage (weight fraction of slurry) on coating stability

Effect of Epoxy/Acrylate Molar Ratio on Coating Properties

The effect of epoxy/acrylate molar ratio on coating properties is shown in Table 3. It can be seen from Table 3 that when the molar ratio of epoxy/acrylate is 1:1, the corrosion resistance, adhesion and weather resistance of the water-based coating are all better. This is because when the molar ratio of the two is 1:1, the molecules are more closely interlocked, and the modification effect is the best. Excess of any one of epoxy resin and acrylate will affect the overall performance of the coating. If there is too much epoxy resin, the weather resistance of the coating will be poor; if the acrylate is too much, the corrosion resistance and adhesion performance of the coating will be average.

Table 3 Effect of epoxy/acrylate molar ratio on coating properties

The Influence of Pigments\Fillers on the Anticorrosion Performance of Coatings

Iron oxide red pigment has excellent performance of high temperature resistance, alkali resistance, light resistance and salt spray resistance. Flake inert fillers such as mica powder, wollastonite and talc powder have stable physical and chemical properties and can be stacked together after filling to prevent The penetration of corrosive media, thus playing the role of initial physical shielding. Zinc phosphate and aluminum tripolyphosphate are added as fillers, and the ions produced by their hydrolysis can react with ferrous ions to form a dense protective thin layer on the metal surface, thereby blocking further corrosion of the metal by the corrosive medium.

The results show that adding iron oxide red, mica powder, wollastonite, talc powder, zinc phosphate and aluminum tripolyphosphate as pigments and fillers can greatly enhance the anti-corrosion properties of the coating through the combination of physical shielding and chemical anti-corrosion. corrosion performance.

Example 2:

A preparation method of modified nano- _SiO2 /epoxy-acrylic latex, comprising the following steps:

1) Preparation of modified nano-SiO ₂ : fully mix 30g oleic acid and 10g nano-SiO ₂ , add 50ml acetone, adjust the pH value to 9, disperse on a high-speed homogeneous disperser for 50min after 40KHz ultrasonic dispersion, and raise the temperature to 110°C , and dried to prepare modified nano-SiO ₂ , which is ready for use;

2) Fully mix 20g of epoxy resin and 3g of modified nano-SiO ₂ , add 50mL of acetone, 10g of acrylate and 3-5 drops of dibutyltin dilaurate. Ionized water 15g, after emulsification is sufficient, remove acetone, add curing agent triethylenetetramine 5g after cooling, make modified nano- _SiO2 /epoxy-acrylate latex after stirring, in the present embodiment, epoxy resin and The molar ratio of acrylate is 1:1.

Adopt above-mentioned latex to prepare water-based anti-corrosion paint, be made up of each component of following mass parts:

Pulping components: 2g wetting agent, 3g defoamer, 7g dispersant, 2g fungicide, 2g multifunctional additive, 8g film-forming additive, 35g mica powder, 35g talcum powder, 22g iron oxide red, zinc phosphate 80g, aluminum tripolyphosphate 23g, titanium dioxide 130g, ethylene glycol 25g, wollastonite 50g, hydroxyethyl cellulose 2g, barium sulfate 150g, sodium hydroxide 2g, water 220g;

Paint mixing components: 360g of the above self-made latex, 3g of thickener, 3g of leveling agent, 7g of ethylene glycol butyl ether, and 2g of defoamer.

The preparation method of above-mentioned waterborne paint, comprises the following steps:

1) Preparation of anti-corrosion slurry: Take water and bactericide into the stirring tank, stir at 500r/min evenly, then add film-forming aids, ethylene glycol, dispersant, wetting agent, hydroxyethyl cellulose, defoamer and multi-functional additives are added to the above dispersion liquid, and stirred at 500r/min evenly;

During the stirring process of the above dispersion liquid, slowly add zinc phosphate, aluminum tripolyphosphate, mica powder, iron oxide red, talc powder, wollastonite, titanium dioxide, barium sulfate, adjust the stirring speed to 1800-2000r/min, and disperse for 16 ~18 minutes, add sodium hydroxide to adjust the pH value to 7, grind until the particle size is less than 40um, and then get the anti-corrosion slurry, which is ready for use;

2) Paint adjustment: Slowly add the anti-corrosion slurry ground in step 1) to the stirring tank, and gradually add the above-mentioned latex, thickener, leveling agent, butyl glycol ether and defoaming agent under 400r/min low-speed stirring agent, and stir evenly to prepare the modified nano-SiO ₂ /epoxy-acrylate water-based anti-corrosion coating.

Most preferably, in step 1), the mass fraction of sodium hydroxide in the anticorrosion slurry is 0.15%.

Example 3:

A preparation method of modified nano- _SiO2 /epoxy-acrylic latex, comprising the following steps:

1) Preparation of modified nano-SiO ₂ : fully mix 25g oleic acid and 8g nano-SiO ₂ , add 45ml acetone, adjust the pH value to 8, disperse on a high-speed homogeneous disperser for 40min after 40KHz ultrasonic dispersion, and raise the temperature to 120°C , and dried to prepare modified nano-SiO ₂ , which is ready for use;

2) Fully mix 18g epoxy resin with 2g modified nano-SiO ₂ , add 40mL of acetone, 8g of acrylate and 3-5 drops of dibutyltin dilaurate. Ionized water 10g, after emulsification is sufficient, remove acetone, add curing agent triethylenetetramine 5g after cooling, make modified nano- _SiO2 /epoxy-acrylate latex after stirring, in the present embodiment, epoxy resin and The molar ratio of acrylate is 1:1. Acrylates can be acrylic acid monomers.

Adopt above-mentioned latex to prepare water-based anti-corrosion paint, be made up of each component of following mass parts:

Pulping components: 1g wetting agent, 2g defoamer, 6g dispersant, 1g bactericide, 1g multifunctional additive, 7g film-forming additive, 34g mica powder, 33g talcum powder, 20g iron oxide red, zinc phosphate 75g, aluminum tripolyphosphate 20g, titanium dioxide 120g, ethylene glycol 24g, wollastonite 47g, hydroxyethyl cellulose 1g, barium sulfate 140g, sodium hydroxide 1g, water 210g;

Paint mixing components: 360g of the above latex, 2g of thickener, 2g of leveling agent, 6g of butyl glycol ether, and 1g of defoamer.

The preparation method of above-mentioned waterborne paint, comprises the following steps:

1) Preparation of anti-corrosion slurry: Take water and bactericide into the stirring tank, stir at 500r/min evenly, then add film-forming aids, ethylene glycol, dispersant, wetting agent, hydroxyethyl cellulose, defoamer and multi-functional additives are added to the above dispersion liquid, and stirred at 500r/min evenly;

During the stirring process of the above dispersion liquid, slowly add zinc phosphate, aluminum tripolyphosphate, mica powder, iron oxide red, talc powder, wollastonite, titanium dioxide, barium sulfate, adjust the stirring speed to 1800-2000r/min, and disperse for 16 ~18 minutes, add sodium hydroxide to adjust the pH value to 7, grind until the particle size is less than 40um, and then get the anti-corrosion slurry, which is ready for use;

2) Paint adjustment: Slowly add the anti-corrosion slurry ground in step 1) to the stirring tank, and gradually add the above-mentioned latex, thickener, leveling agent, butyl glycol ether and defoaming agent under 400r/min low-speed stirring agent, and stir evenly to prepare the modified nano-SiO ₂ /epoxy-acrylate water-based anti-corrosion coating.

In order to further embody the beneficial effect of the present invention, particularly enumerate following test example:

Comprehensive performance of water-based anti-corrosion coatings:

Impact resistance is tested according to GB/T 1732-1993; adhesion is tested according to GB/T 1720-1979; pencil hardness is tested according to GB/T 6739-1996; water resistance is tested according to GB/T 1733-1993; salt spray resistance is tested according to GB/T1771-2007 test.

Spray 2 roads of water-based anti-corrosion paint coatings in the present invention on the treated tin plate, and then spray 1 road of the coatings after 1 d, and dry for 150 hours at a humidity of 60% and a temperature of 25 ° C to obtain a total dry film thickness. It is a 110um anti-corrosion coating, and the test results are shown in Table 4.

Table 4 Performance test results of waterborne anticorrosion coatings

In summary, the present invention modifies nano-SiO ₂ with oleic acid, fully mixes the modified nano-SiO ₂ , epoxy resin and acrylate, and obtains modified nano-SiO ₂ /epoxy-acrylate latex after reaction. A new type of modified nano _{-SiO 2 /} Epoxy-acrylate water-based anti-corrosion coating, the adhesion of the coating reaches grade 1, the impact resistance reaches 50cm, the pencil hardness reaches 2H, and it has the characteristics of good storage stability, weather resistance and excellent physical and mechanical properties.

Claims (7)

1. a kind of modified Nano SiO₂The preparation method of/epoxy-acrylate latex, it is characterised in that：Comprise the following steps：

1) modified Nano SiO₂Preparation：By 20~30g oleic acid and 5~10g Nano-meter SiO_2s₂It is sufficiently mixed, adds 40~50mL third Ketone, regulation pH value is to disperse 30~50min on high speed homogenization dispersion machine after 8~9,40KHz ultrasonic waves disperse, and temperature rises to 110~120 DEG C, drying is obtained modified Nano SiO₂, it is stand-by；

2) by 18~20g epoxy resin and 2~3g modified Nanos SiO₂It is sufficiently mixed, adds 40~50mL of acetone, acrylate 8 ~10g and dibutyl tin laurate 3~5 drip, and after ultrasonic wave dispersion 30min, are warming up to 90 DEG C, are incubated 3h, add deionization Water 10~15g, it is to be emulsified fully after, remove acetone, curing agent 3~5g of triethylene tetramine is added after cooling, made after stirring Obtain modified Nano SiO₂/ epoxy-acrylate latex.

2. modified Nano SiO as claimed in claim 1₂The preparation method of/epoxy-acrylate latex, it is characterised in that：Institute The epoxy resin stated is 1: 1 with the mol ratio of acrylate.

3. the modified Nano SiO made by a kind of preparation method as described in claim 1 or 2₂/ epoxy-acrylate breast Glue.

4. the modified Nano SiO in claim 3₂Application of/epoxy-acrylate the latex in watery anti-corrosion paint is prepared.

5. a kind of watery anti-corrosion paint, it is characterised in that：It is made up of each component of following masses number：

Slurrying component：1~2g of wetting agent, 2~3g of defoamer, 5~7g of dispersant, 1~2g of bactericide, 1~2g of multifunctional assistant, 5~8g of coalescents, 31~35g of mica powder, 31~35g of talcum powder, 20~22g of iron oxide red, 75~80g of trbasic zinc phosphate, trimerization 20~23g of aluminum phosphate, 110~130g of titanium dioxide, 21~25g of ethylene glycol, 47~50g of wollastonite, hydroxyethyl cellulose 1~ 2g, 130~150g of barium sulfate, 1~2g of NaOH, 200~220g of water；

Paint component：350~360g of latex in claim 3,2~3g of thickener, 2~3g of levelling agent, butyl glycol ether 5~ 7g, 1~2g of defoamer.

6. the preparation method of the watery anti-corrosion paint in a kind of claim 5, it is characterised in that:Comprise the following steps：

1) anti-corrosive pulp is prepared：Water intaking, bactericide are added in stirred tank, and 500r/min stirs, and is subsequently adding film forming and helps Agent, ethylene glycol, dispersant, wetting agent, hydroxyethyl cellulose, defoamer and multifunctional assistant, 500r/min stir；

In above-mentioned dispersion liquid whipping process, be slowly added to trbasic zinc phosphate, aluminium triphosphate, mica powder and iron oxide red, talcum powder, Wollastonite, titanium dioxide, barium sulfate, 1800~2000r/min is adjusted to by stir speed (S.S.), disperses 16~18min, adds hydroxide Sodium is ground to granularity less than 40um to adjust pH value as 7, obtains final product anti-corrosive pulp, stand-by；

2) paint：Be slowly added to step 1 toward stirred tank) in ground anti-corrosive pulp, under 400r/min stirring at low speed, gradually The latex and thickener, levelling agent, butyl glycol ether and defoamer in claim 2 are added, is stirred, that is, modified receiving is obtained Rice SiO₂/ epoxy-acrylate watery anti-corrosion paint.

7. the preparation method of watery anti-corrosion paint as claimed in claim 6, it is characterised in that:Step 1) in, NaOH The mass fraction for accounting for anti-corrosive pulp is 0.15%.