CN106118319A - A kind of aqueous stripping lacquer and preparation method thereof - Google Patents

Abstract

The invention relates to a water-based strippable coating and a preparation method thereof. The raw materials of the coating include by weight: 35-55 parts of a polymerized monomer, 2-5 parts of an emulsifier, 5-10 parts of an inorganic filler, and 5-5 parts of a stripping agent 10 parts, 0.5-3 parts of toughening agent, the total amount is 100 parts, and the balance is water; the polymerization monomers are methyl methacrylate, styrene, butyl acrylate and acrylic acid. The preparation method includes: adding polymer monomers and emulsifiers into water and mixing, pre-emulsifying, adding an initiator and stirring to obtain a mixed emulsion; mixing the initiator, emulsifier and water, stirring and heating to 60°C, and then adding the mixed emulsion dropwise, Keep warm; adjust the pH to 7‑9, add a toughening agent, and continue stirring; add inorganic fillers and stripping agents, stir, cool down, and filter out. The method of the invention is environmentally friendly and easy to operate; the obtained coating has a wide range of applications and is used on the surfaces of various instruments and substrates to protect and prevent pollution.

Description

A kind of water-based peelable coating and preparation method thereof

technical field

The invention belongs to the field of paint and its preparation, in particular to a water-based peelable paint and a preparation method thereof.

Background technique

Peelable coating is a new type of high-quality surface protection film, which has the advantages of simple preparation process, good protection performance, and convenient post-processing. It is widely used in the surface protection of precision parts, instruments, electronic equipment and other devices. The emergence of water-based peelable coatings complies with consumers' requirements for environmental protection and avoids the use of large amounts of volatile organic compounds. Therefore, the research on water-based strippable coatings is of great significance to the development of national science and technology and the progress of society, and it is one of the fields that have attracted widespread attention in recent years.

Polyacrylate emulsion is a kind of water-based paint. Polyacrylate emulsion uses water as the dispersion medium. It not only has the advantages of environmental protection and pollution-free, wide source of raw materials, mild reaction conditions, etc., but also its latex film has good flexibility and high transparency. It is widely used in construction, automobiles, electronic appliances, leather, Books, fabrics and medical polymers and many other fields. However, polyacrylate emulsions also have some disadvantages, such as poor water and oil resistance, poor weather resistance, and poor mechanical properties of the latex film, which are difficult to meet the requirements of high-performance fields, which has become the main factor limiting its further application.

Contents of the invention

The technical problem to be solved by the present invention is to provide a water-based strippable coating and a preparation method thereof. The obtained water-based strippable coating has wide adaptability and excellent mechanical properties.

A water-based peelable coating of the present invention, the raw materials of the coating include by weight: 35-55 parts of polymerized monomers, 0.003-0.005 parts of initiators, 2-5 parts of emulsifiers, 5-10 parts of inorganic fillers, stripping 5-10 parts of the toughening agent, 0.5-3 parts of the toughening agent, the total amount is 100 parts, and the balance is water; wherein, the polymerization monomers are methyl methacrylate, styrene, butyl acrylate and acrylic acid.

The mass ratio of the butyl acrylate, styrene, methyl methacrylate and acrylic acid is 50-70:30-50:10:10.

The emulsifier is one or both of sodium lauryl sulfate, sodium lauryl sulfate and OP-10.

The inorganic filler is zinc stearate, titanium dioxide or barium carbonate.

The peeling agent is at least one of polyethylene glycol and calcium stearate.

The toughening agent is dibutyl phthalate.

A kind of preparation method of water-based strippable paint of the present invention comprises:

(1) Add butyl acrylate, styrene, methyl methacrylate, acrylic acid and 2/3 parts of emulsifier into water and stir and mix; then perform pre-emulsification, then add part of the initiator and continue stirring to obtain a mixed emulsion;

(2) Add the remaining initiator, 1/3 part of emulsifier and water into the reaction vessel for mixing, stir and heat to 60°C and start adding the mixed emulsion in (1) dropwise. After all the drops are completed, keep warm for 2-3 hours; then adjust the pH of the emulsion to 7-9, add a toughening agent, and continue to stir for 30 minutes; then add inorganic fillers and stripping agents, respectively, and stir until dissolved, and finally cool the emulsion to normal temperature, and filter the material through a 200-mesh sieve;

The above raw materials are in parts by weight: 35-55 parts of polymerized monomer, 0.003-0.005 part of initiator, 2-5 parts of emulsifier, 5-10 parts of inorganic filler, 5-10 parts of stripping agent, 0.5-3 parts of toughening agent Parts, the total amount is 100 parts, and the balance is water; Wherein, the polymerization monomer is methyl methacrylate, styrene, butyl acrylate and acrylic acid;

In step (1), the consumption of emulsifier is 2/3 of the total amount of emulsifier; in step (2), the consumption of emulsifier is 1/3 of the total amount of emulsifier; in step (1), the amount of initiator potassium persulfate is The total amount of initiator is 2/3; the amount of potassium persulfate of initiator is 1/3 of the total amount of initiator in the step (2).

The pre-emulsification conditions are as follows: ultrasonication for 10-20 minutes, followed by stirring with a high-speed dispersing homogenizer for 0.5-1 minute at a stirring speed of 1000 r/min.

The water-based polyacrylate emulsion of the invention is polymerized from butyl acrylate, styrene, methyl methacrylate and acrylic acid, and is environmentally friendly and easy to operate. The polyacrylate emulsion provided by the invention has a small particle size (80-100nm) and a wide application range, and can be used on the surfaces of substrates such as automobiles, ships, various instrument shells, furniture, range hoods and ceramics to protect and prevent pollution.

Beneficial effect

(1) The prepared coating of the present invention can be sprayed on different substrate surfaces and can be easily peeled off, and the substrate surfaces involved are relatively smooth surfaces;

(2) The product of the present invention is easy to construct, has moderate bonding force with the base material, can be peeled off in a large area in practical application, and has no residual glue on the base material surface;

(4) The prepared coating of the present invention is resistant to acid and alkali after forming a film, soaked in acid solution and lye for a long time, the coating film does not appear foaming, wrinkled, and comes off;

(5) The present invention adopts the pre-emulsification semi-continuous process to prepare the polyacrylate emulsion, which has the characteristics of simple operation, environmental friendliness, mass production and low cost.

Description of drawings

Fig. 1 is the effect figure that embodiment 1 product is sprayed on furniture surface;

Fig. 2 is the effect diagram that the product of embodiment 1 is coated on glass surface;

Fig. 3 is the effect figure that the product of embodiment 2 is coated on the nail cover;

Fig. 4 is an effect diagram of spraying the product of Example 3 on the outside of the Haier refrigerator.

detailed description

Below in conjunction with specific embodiment, further illustrate the present invention. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

In the embodiment, the density of butyl acrylate is 0.8975g/ml, the density of acrylic acid is 1.0495g/ml, the density of styrene is 0.9g/ml, and the density of methyl methacrylate is 0.9395g/ml.

Example 1

Take 15.59ml of butyl acrylate, 2.40ml of acrylic acid, 7.25ml of styrene, 2.40ml of methyl methacrylate, 1.00g of sodium lauryl sulfate and 25ml of deionized water into a beaker and mix them evenly, then disperse them by ultrasonic for 20min at high speed Stir with a homogenizer for 1 min for pre-emulsification; then add 0.24 g of potassium persulfate and continue stirring to obtain a mixed emulsion.

Add 10ml of water, 0.5g of sodium lauryl sulfate and 0.12g of potassium persulfate into the Erlenmeyer flask, stir and heat, and start adding the mixed emulsion dropwise when the temperature rises to 60°C, and control the dropwise addition within 2-3h.

After the dropwise addition, keep warm for 2.5 hours, adjust the pH to 7.5 with ammonia water, and add 1.50 g of dibutyl phthalate to react for 30 minutes. Then add 3.5g of barium carbonate and 2g of polyethylene glycol respectively, stir until dissolved, finally cool down to room temperature, filter and discharge, and obtain a water-based peelable coating.

Spray the paint on the sample board and let it stand at room temperature for 2h to dry.

Fig. 1 is the effect drawing that the product of the present embodiment is sprayed on the furniture surface; Fig. 2 is the effect drawing that the product of the present embodiment is coated on the glass surface;

Example 2

Take 15.59ml of butyl acrylate, 2.40ml of acrylic acid, 7.25ml of styrene, 2.40ml of methyl methacrylate, 1.00g of sodium lauryl sulfate and 25ml of deionized water into a beaker and mix them evenly, then disperse them by ultrasonic for 20min at high speed Stir with a homogenizer for 1 min for pre-emulsification; then add 0.24 g of potassium persulfate and continue stirring to obtain a mixed emulsion.

Add 10ml of water, 0.5g of sodium lauryl sulfate and 0.12g of potassium persulfate into the Erlenmeyer flask, stir and heat, and start adding the mixed emulsion dropwise when the temperature rises to 60°C, and control the dropwise addition within 2-3h.

After the dropwise addition, keep warm for 3 hours, adjust the pH to 7.5 with ammonia water, and add 1.50 g of dibutyl phthalate to react for 30 minutes. Then add 3.5g of barium carbonate and 2g of calcium stearate respectively, stir until dissolved, finally cool down to room temperature, filter and discharge, and obtain a water-based peelable coating.

Spray the paint on the sample board and let it stand at room temperature for 2h to dry. Fig. 3 is the effect drawing that the product of this embodiment is applied on the nail cover.

Example 3

Take 15.59ml of butyl acrylate, 2.40ml of acrylic acid, 7.25ml of styrene, 2.40ml of methyl methacrylate, 1.00g of sodium lauryl sulfate and 25ml of deionized water into a beaker and mix them evenly, then disperse them by ultrasonic for 20min at high speed Stir with a homogenizer for 1 min for pre-emulsification; then add 0.24 g of potassium persulfate and continue stirring to obtain a mixed emulsion.

Add 10ml of water, 0.30g of sodium lauryl sulfate, 0.20g of OP-10 and 0.12g of potassium persulfate into the Erlenmeyer flask, stir and heat, and when the temperature rises to 60°C, start to drop the mixed emulsion, and control the drop within 2-3h Plus done.

After the dropwise addition, keep warm for 2 hours, adjust the pH to 7.5 with ammonia water, and add 1.50 g of dibutyl phthalate to react for 30 minutes. Then add 3.5g of barium carbonate and 2g of polyethylene glycol respectively, stir until dissolved, finally cool down to room temperature, filter and discharge, and obtain a water-based peelable coating.

Spray the paint on the sample board, and let it stand at room temperature for 2 hours to dry; Figure 4 is the effect diagram of the product of this embodiment sprayed on the outside of the Haier refrigerator.

Example 4

Take 16.37ml of butyl acrylate, 2.40ml of acrylic acid, 6.47ml of styrene, 2.40ml of methyl methacrylate, 1.00g of sodium lauryl sulfate and 25ml of deionized water into a beaker and mix them evenly, then disperse them by ultrasonic for 20min at high speed Stir with a homogenizer for 1 min for pre-emulsification; then add 0.24 g of potassium persulfate and continue stirring to obtain a mixed emulsion.

Add 10ml of water, 0.5g of sodium lauryl sulfate and 0.12g of potassium persulfate into the Erlenmeyer flask, stir and heat, and start adding the mixed emulsion dropwise when the temperature rises to 60°C, and control the dropwise addition within 2-3h.

After the dropwise addition, keep warm for 2.5 hours, adjust the pH to 7.5 with ammonia water, and add 1.50 g of dibutyl phthalate to react for 30 minutes. Then add 3.5g of barium carbonate and 2g of calcium stearate respectively, stir until dissolved, finally cool down to room temperature, filter and discharge, and obtain a water-based peelable coating.

Spray the paint on the sample board and let it stand at room temperature for 2h to dry.

Performance tests were carried out on the products of the above-mentioned Examples 1-4, and the results are as follows.

Table 1 is the breaking strength and elongation at break of the coating film of the above embodiments 1-4:

Table 1

Example 1 2 3 4 Breaking strength/MPa 8.96 9.18 10.05 9.07 Elongation at break/% 1072 1121 1200 1103

Carry out following performance test to the coating film that above-mentioned embodiment prepares:

A. Peeling test, to investigate whether the coating film is easy to peel off.

◎Easy to peel off; ○Good peelability; Δpeeling is difficult; ×Cannot peel off

B. Acid resistance test, after dropping 40% sulfuric acid on the coating film for 12 hours, observe whether there is any corrosion trace.

◎With traces of corrosion; ×Without traces of corrosion

C. Alkali resistance test, drop 0.1 standard concentration of sodium hydroxide on the coating film for 12 hours, and then observe whether there are corrosion marks.

◎With traces of corrosion; ×Without traces of corrosion

D. Water resistance test, soak the coating film in deionized water for 24 hours, observe whether the coating film has bubbles and cracks, and whether it is easy to peel off.

◎No blistering and cracking, easy to peel off;

○No blistering and cracking, good peelability;

× Blisters, cracks or cannot be peeled off

E. Low temperature resistance test, place the coating film at 80°C for 72 hours to observe whether the coating film is cracked or easy to peel off.

◎No cracking, easy to peel off; ×Crack or can't peel off

The test result of embodiment 1-4 is as shown in table 2 below:

Table 2

test A B C D. E. Example 1 ○ ○ ◎ ◎ ◎ Example 2 ◎ ○ ○ ◎ ○ Example 3 ◎ ◎ ○ ○ ○ Example 4 ◎ ◎ ○ ◎ ◎

Claims (9)

1. A water-based peelable paint, is characterized in that, the raw material of described paint comprises by weight: polymerized monomer 35-55 part, initiator 0.003-0.005 part, emulsifier 2-5 part, inorganic filler 5-10 part 5-10 parts, 5-10 parts of stripping agent, 0.5-3 parts of toughening agent, the total amount is 100 parts, and the balance is water; wherein, the polymerization monomers are methyl methacrylate, styrene, butyl acrylate and acrylic acid. 2. A kind of water-based peelable coating according to claim 1, characterized in that, the mass ratio of said butyl acrylate, styrene, methyl methacrylate, and acrylic acid is 50-70:30-50:10: 10. 3. a kind of water-based peelable paint according to claim 1, is characterized in that, described initiator is potassium persulfate. 4. a kind of water-based peelable paint according to claim 1, is characterized in that, described emulsifying agent is one or both in sodium lauryl sulfate, sodium lauryl sulfate and OP-10 . 5. A kind of water-based peelable paint according to claim 1, characterized in that, the inorganic filler is zinc stearate, titanium dioxide or barium carbonate. 6. A kind of water-based peelable paint according to claim 1, characterized in that, said stripper is at least one of polyethylene glycol and calcium stearate. 7. A kind of water-based peelable paint according to claim 1, characterized in that, the toughening agent is dibutyl phthalate. 8. A preparation method for a water-based peelable coating, comprising: (1) Add butyl acrylate, styrene, methyl methacrylate, acrylic acid and part of the emulsifier to the water and stir and mix; then pre-emulsify, then add part of the initiator and continue stirring to obtain a mixed emulsion; (2) Mix the remaining initiator, remaining emulsifier and water, stir and heat to 60°C, then add the mixed emulsion in (1) dropwise, keep it warm for 2-3 hours; then adjust the pH of the emulsion to 7-9, add toughening agent, continue to stir; then add inorganic filler and stripping agent, stir until dissolved, cool down to normal temperature, filter and discharge; The above raw materials are in parts by weight: 35-55 parts of polymerized monomers, 0.003-0.005 parts of initiators, 2-5 parts of emulsifiers, 5-10 parts of inorganic fillers, 5-10 parts of stripping agents, and 0.5-3 parts of toughening agents parts, the total amount is 100 parts, and the balance is water; wherein, the polymerization monomers are methyl methacrylate, styrene, butyl acrylate and acrylic acid. 9. The preparation method of a kind of water-based peelable coating according to claim 8, is characterized in that, the condition of described pre-emulsification is: first ultrasonic 10-20min, then stir 0.5-1min with high-speed dispersion homogenizer, stir The speed is 1000r/min.