CN106700715B - Cleaning agent for removing paint on plastic surface and preparation method thereof - Google Patents

Abstract

The invention discloses a cleaning agent for removing paint on the surface of plastic, which consists of the following components in parts by weight: 20-40 parts of cleaning agent, 10-30 parts of auxiliary agent, 5-15 parts of citric acid, 1-5 parts of surfactant, 1-3 parts of dispersing agent, 1-3 parts of reinforcing agent and 30-60 parts of water; the invention also discloses a preparation method of the cleaning agent for removing the paint on the surface of the plastic. The invention has the advantages of simple and easy-to-use process formula, safety, environmental protection, low cost, no color, no odor, low volatility and good paint removing effect, and the paint-removed plastic does not change color, yellow, soften or crisp and has good application prospect.

Description

Cleaning agent for removing paint on plastic surface and preparation method thereof

Technical Field

The invention relates to the field of recycling of waste plastics, in particular to a cleaning agent for removing paint on the surface of plastic and a preparation method thereof.

Background

After the waste plastics are recovered, a large amount of paint is attached to the waste plastics, if the paint is not effectively cleaned, the regenerated particles are directly granulated, so that the grade of the regenerated particles is low, the plastic is easy to age, the recovery performance is reduced, and the prepared product is not attractive enough in appearance, short in service life and poor in quality. The existing waste plastic recycling technology is not mature enough, a large amount of waste plastics can be recycled, a uniform cleaning agent specially aiming at paint on the surface of the waste plastics does not exist, the paint strippers in the market are mostly not suitable for cleaning the waste plastics, and the paint strippers have great damage to waste plastic substrates and great environmental pollution.

The invention patent with application number CN201210191842.2 discloses a paint removing and cleaning method and a paint removing and cleaning agent thereof, wherein the paint removing and cleaning agent comprises the following components in percentage by weight: 0.1-0.5% of fatty alcohol ethylene oxide condensate, 0.3-2% of isomeric alkyl alcohol ether, 0.3-2% of alkyl methyl ammonium chloride, 0.2-1% of alkyl polysaccharide glycerol and 0.2-1% of fatty alcohol polyoxyethylene ether, and the paint removing cleaning agent has the advantages that the raw materials are matched with each other, the advantages are complementary, so that the plastic cleaning agent has good penetration and cleaning capability, not only has strong stripping capability on different types of coatings of TPO, but also is colorless, tasteless, harmless to human bodies, recyclable and long in service life. However, the paint-removing cleaning agent is easy to yellow and crisp after paint removal, influences the secondary utilization of the plastic and has no wide application prospect.

Disclosure of Invention

The invention provides the cleaning agent for removing the paint on the surface of the plastic, which has the advantages of simple and easy-to-use process formula, safety, environmental protection, low cost, no color, no odor, low volatility, good paint removing effect, no discoloration, no yellowing, no softening and no brittleness after paint removing, and the preparation method thereof.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows: a cleaning agent for removing paint on the surface of plastic comprises the following components: the cleaning agent, the auxiliary agent, the citric acid, the surfactant, the dispersant, the reinforcing agent and the water;

further, the coating comprises the following components in parts by weight: 20-40 parts of cleaning agent, 10-30 parts of auxiliary agent, 5-15 parts of citric acid, 1-5 parts of surfactant, 1-3 parts of dispersing agent, 1-3 parts of reinforcing agent and 30-60 parts of water;

further, the detergent is sodium ethylene diamine tetracetate;

further, the auxiliary agent is modified zeolite, and the preparation method comprises the following steps: grinding zeolite into powder of 150-300 meshes, soaking the powder for 3 to 6 hours at 50 to 80 ℃ by using an organic acid modifier, adding an organic alkaline reagent for neutralization until the pH value is 3 to 6; the organic acidic modifier is one or more of malic acid, oxalic acid, lactic acid and oxalic acid; the alkaline reagent is one or more of triethylamine and pyridine;

further, the surfactant site is a nonionic surfactant;

further, the nonionic surfactant is fatty alcohol-polyoxyethylene ether;

further, the dispersing agent is sodium dodecyl sulfate;

further, the reinforcing agent is a mixture of polystyrene and thiourea.

The invention also discloses a preparation method of the cleaning agent for removing the paint on the surface of the plastic, which comprises the following steps:

(1) mixing surfactant, dispersant and intensifier, adding water, and stirring thoroughly;

(2) and (2) mixing the fully stirred material in the step (1) with a cleaning agent, an auxiliary agent and citric acid, stirring and dispersing, heating to 50-90 ℃, preserving heat for 0.5-3 hours, and stirring at the rotation speed of 100-1000r/min to obtain the product cleaning agent.

Further, the stirring speed is 200-300 r/min.

The invention has the beneficial effects that:

the invention has the advantages of simple and easy-to-use process formula, safety, environmental protection, low cost, no color, no odor, low volatility and good paint removing effect, and the paint-removed plastic does not change color, yellow, soften or crisp and has good application prospect. The paint removing effect is obviously improved by adding the auxiliary agent to modify the zeolite, and the polystyrene and the thiourea are used as reinforcing agents, so that the plastic after paint removing is not discolored, yellowed, softened and brittle, and the effect is superior to that of the existing plastic paint removing agent on the market.

Detailed Description

The present invention will be further described with reference to the following examples. The examples are intended to illustrate the invention, but not to limit it in any way.

Example 1:

the paint consists of the following components in parts by weight: 20 parts of sodium ethylene diamine tetracetate, 10 parts of modified zeolite, 5 parts of citric acid, 1 part of fatty alcohol-polyoxyethylene ether, 1 part of sodium dodecyl sulfate, 1 part of a mixture of polystyrene and thiourea in a weight ratio of 1:1 and 50 parts of water.

The preparation method of the modified zeolite comprises the following steps: the zeolite was ground to 300 mesh powder, soaked with lactic acid at 50 ℃ for 6 hours, neutralized with triethylamine to pH 6.

The preparation process of the cleaning agent for removing the paint on the surface of the plastic comprises the following steps:

(1) mixing sodium dodecyl sulfate, fatty alcohol-polyoxyethylene ether, polystyrene and thiourea in a weight ratio of 1:1, adding water, and fully stirring;

(2) and (2) mixing the fully stirred material obtained in the step (1) with sodium ethylene diamine tetracetate, modified zeolite and citric acid, stirring and dispersing, heating to 50 ℃, preserving heat for 3 hours, and stirring at the rotating speed of 100r/min to obtain the product cleaning agent for removing the paint on the surface of the plastic.

Example 2:

the paint consists of the following components in parts by weight: 40 parts of sodium ethylene diamine tetracetate, 30 parts of modified zeolite, 15 parts of citric acid, 5 parts of fatty alcohol-polyoxyethylene ether, 3 parts of sodium dodecyl sulfate, 3 parts of a mixture of polystyrene and thiourea in a weight ratio of 1:1 and 50 parts of water.

The preparation method of the modified zeolite comprises the following steps: the zeolite was ground to 300 mesh powder, soaked with lactic acid at 50 ℃ for 6 hours, neutralized with triethylamine to pH 6.

Comparative example 1:

the paint consists of the following components in parts by weight: 30 parts of sodium ethylene diamine tetracetate, 10 parts of citric acid, 3 parts of fatty alcohol-polyoxyethylene ether, 3 parts of sodium dodecyl sulfate and 50 parts of water.

The preparation process of the cleaning agent for removing the paint on the surface of the plastic comprises the following steps:

(1) mixing sodium dodecyl sulfate and fatty alcohol-polyoxyethylene ether, adding water, and fully stirring;

(2) and (2) mixing the fully stirred material obtained in the step (1) with sodium ethylene diamine tetracetate and citric acid, stirring and dispersing, heating to 50 ℃, preserving heat for 3 hours, and stirring at the rotating speed of 100r/min to obtain the product cleaning agent for removing the paint on the surface of the plastic.

Example 4:

the plastic needing paint removal treatment is soaked in acetic acid, ultrasonically washed for 5 minutes, removed, soaked in the cleaning agent for removing the paint on the surface of the plastic obtained by the formula of the embodiment 1-2 and the comparative example 1, and ultrasonically washed for 10 minutes.

The paint stripping efficiency (i.e. the percentage of area of paint film that expands and wrinkles in a given time) of a paint stripper was determined according to the national standard HG/T2881-1997 "paint stripper stripping efficiency determination", and the formula for calculating the paint stripping efficiency was as follows:

paint stripping efficiency/%, i.e. the area of the paint film with loose wrinkles/the total area of the paint film before paint stripping multiplied by 100%

The following table shows the comparative performance of the cleaning agent for removing paint on the surface of plastic prepared by the formula of examples 1-3 and comparative example 1:

TABLE 1 test results

	Example 1	Example 2	Comparative example 1
				Paint removal efficiency	96％	92％	75％
Whether yellowing and embrittlement occur	Whether or not	Whether or not	Is that
				Whether or not to become soft	Whether or not	Whether or not	Is that
Appearance of paint film after cleaning	Complete removal of	Complete removal of	Almost dissolve

The invention has the advantages of simple and easy-to-use process formula, safety, environmental protection, low cost, no color, no odor, low volatility and good paint removing effect, and the paint-removed plastic does not change color, yellow, soften or crisp and has good application prospect.

The above embodiments are only for illustrating the technical concept and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention accordingly, and not to limit the protection scope of the present invention accordingly. All equivalent changes or modifications made in accordance with the spirit of the present disclosure are intended to be covered by the scope of the present disclosure.

Claims (3)

1. The cleaning agent for removing the paint on the surface of the plastic is characterized by comprising the following components: 20-40 parts of a cleaning agent, 10-30 parts of an auxiliary agent, 5-15 parts of citric acid, 1-5 parts of a surfactant, 1-3 parts of a dispersing agent, 1-3 parts of a reinforcing agent and 30-60 parts of water, wherein the cleaning agent is sodium ethylene diamine tetracetate, the surfactant is a nonionic surfactant, the nonionic surfactant is fatty alcohol polyoxyethylene ether, the dispersing agent is sodium dodecyl sulfate, the reinforcing agent is a mixture of polystyrene and thiourea, the ratio of the polystyrene to the thiourea is 1:1, the auxiliary agent is modified zeolite, and the preparation method of the auxiliary agent comprises the following steps: grinding zeolite into powder of 150-300 meshes, soaking the powder for 3 to 6 hours at 50 to 80 ℃ by using an organic acid modifier, adding an organic alkaline reagent for neutralization until the pH value is 3 to 6; the organic acidic modifier is one or more of malic acid, lactic acid and oxalic acid; the alkaline reagent is at least one of triethylamine and pyridine.

2. The method for preparing the cleaning agent for removing paint on the surface of plastic as claimed in claim 1, which comprises the following steps:

(1) mixing surfactant, dispersant and intensifier, adding water, and stirring thoroughly;

(2) and (2) mixing the fully stirred material in the step (1) with a cleaning agent, an auxiliary agent and citric acid, stirring and dispersing, heating to 50-90 ℃, preserving heat for 0.5-3 hours, and stirring at the rotation speed of 100-1000r/min to obtain the product cleaning agent.

3. The method as claimed in claim 2, wherein the stirring speed is 200-300 r/min.