CN111876274A - Alkaline cleaning agent and preparation method and application thereof - Google Patents

Abstract

The invention relates to an alkaline cleaning agent and a preparation method and application thereof. The alkaline cleaning agent comprises the following components in parts by weight: 1-5 parts of strong base, 10-20 parts of ethylene glycol, 70-80 parts of benzyl alcohol, 1-3 parts of N, N-dimethylformamide and 1-5 parts of water. In some embodiments, the alkali is 2 to 5 parts, the glycol is 10 to 20 parts, the benzyl alcohol is 70 to 80 parts, the N, N-dimethylformamide is 1.5 to 3 parts, and the water is 3 to 5 parts by weight. The alkaline cleaning agent takes benzyl alcohol as a main cleaning active ingredient, is assisted by combined action of ethylene glycol and N, N-dimethylformamide, contains strong alkali and water to prepare the alkaline water-based cleaning agent, is controlled in a specific composition proportion, has strong cleaning capability, is not only used for strong cleaning capability of coating liquid, but also has strong cleaning capability of paint slag in a pipeline, and can be suitable for cleaning the pipeline with serious slag bonding.

Description

Alkaline cleaning agent and preparation method and application thereof

Technical Field

The invention relates to the technical field of cleaning agents, in particular to an alkaline cleaning agent and a preparation method and application thereof.

Background

In the technical field of automobile coatings, a pipeline is needed to convey the coatings; after long-term use, the paint slag in the pipeline is piled up, so that the pipeline needs to be cleaned regularly. The cleaning agent used in the prior pipeline comprises a weakly alkaline water-based cleaning agent or a solvent-based cleaning agent. The conventional solvent type cleaning agent cleans a paint conveying pipeline with serious paint residue deposition, and has long cleaning time and poor cleaning effect. The existing alkalescent water-based cleaning agent mainly uses N, N-dimethylformamide as a main cleaning component, is expensive and high in cost, has strong cleaning capability on coating liquid, but has weak cleaning capability on paint residues in pipelines, and cannot meet the requirement on cleaning pipelines with serious slag bonding.

Disclosure of Invention

Accordingly, there is a need for an alkaline cleaner with improved cleaning ability, and a method for preparing and using the same.

An alkaline cleaning agent comprises the following components in parts by weight: 1-5 parts of strong base, 10-20 parts of ethylene glycol, 70-80 parts of benzyl alcohol, 1-3 parts of N, N-dimethylformamide and 1-5 parts of water.

In some embodiments, the alkali is 2 to 5 parts, the glycol is 10 to 20 parts, the benzyl alcohol is 70 to 80 parts, the N, N-dimethylformamide is 1.5 to 3 parts, and the water is 3 to 5 parts by weight.

The alkaline cleaning agent takes benzyl alcohol as a main cleaning active ingredient, is assisted by combined action of ethylene glycol and N, N-dimethylformamide, contains strong alkali and water to prepare the alkaline water-based cleaning agent, is controlled in a specific composition proportion, has strong cleaning capability, is not only used for strong cleaning capability of coating liquid, but also has strong cleaning capability of paint slag in a pipeline, and can be suitable for cleaning the pipeline with serious slag bonding.

Particularly, the alkaline cleaning agent is particularly suitable for cleaning paint residues of pipelines for automobile coating paint, has strong cleaning force and short cleaning time, saves manpower and labor time and provides cleaning efficiency.

Further, the above alkaline cleaner has a low solvent content, and benzyl alcohol and ethylene glycol have boiling points of about 200 ℃, and N, N-dimethylformamide, which is a small content, is also at 150 ℃ or higher, so that the VOC (volatile organic substance) emission of the alkaline cleaner is low.

In addition, the components of the alkaline cleaning agent have wide sources, are economical and practical, and avoid the problems of high price and high cost of the cleaning agent which takes N, N-dimethylformamide as a main cleaning component.

In some embodiments, the alkali is 2 to 5 parts, the glycol is 16 to 17 parts, the benzyl alcohol is 74 to 76 parts, the N, N-dimethylformamide is 1.5 to 2 parts, and the water is 3 to 5 parts by weight. The skilled person of the present invention has found that by further controlling the components of the above alkaline cleaner within this ratio range, the cleaning ability of the alkaline cleaner can be further improved.

In some of these embodiments, the total parts by weight of the strong base, the ethylene glycol, the benzyl alcohol, the N, N-dimethylformamide, and the water is 100 parts. The skilled person of the present invention has found that by further controlling the components of the above alkaline cleaner within this ratio range, the cleaning ability of the alkaline cleaner can be further improved.

In some of these embodiments, the strong base is 3 parts, the ethylene glycol is 16.5 parts, the benzyl alcohol is 75 parts, the N, N-dimethylformamide is 1.5 parts, and the water is 4 parts. The skilled person of the present invention has found that by further controlling the above-mentioned components of the alkaline cleaner in such proportions, the cleaning ability of the alkaline cleaner can be further improved.

In some of these embodiments, the strong base is at least one of sodium hydroxide and potassium hydroxide. It is understood that these two strong bases have good solubility in the above-described system of alkaline cleaners and are low in cost. More preferably, the strong base is potassium hydroxide.

A preparation method of an alkaline cleaner comprises the following steps:

providing raw materials according to the components of the alkaline cleaning agent;

mixing the above materials.

The preparation method is simple in process, and the prepared alkaline cleaning agent has strong cleaning capability, is not only used for cleaning coating liquid, but also has strong cleaning capability for paint slag in pipelines, and can be suitable for cleaning pipelines with serious slag bonding.

In some embodiments, the step of uniformly mixing the raw materials comprises the following steps:

and mixing and dissolving the strong base, the water and the ethylene glycol, then adding the benzyl alcohol and the N, N-dimethylformamide, and uniformly mixing.

Use of an alkaline cleaner as described in any of the above for cleaning paints.

A method for cleaning a pipeline for a coating material, which comprises the step of cleaning the pipeline by using the alkaline cleaning agent.

Drawings

FIG. 1 is a photograph of a stainless steel plate cleaned with the alkaline cleaner of examples 1 to 2;

FIG. 2 is a photograph showing a stainless steel plate cleaned with the alkaline cleaner of comparative examples 1 to 4.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The invention provides an alkaline cleaning agent, which comprises the following components in parts by weight: 1-5 parts of strong base, 10-20 parts of ethylene glycol, 70-80 parts of benzyl alcohol, 1-3 parts of N, N-dimethylformamide and 1-5 parts of water.

N, N-Dimethylformamide (DMF) is colorless transparent liquid, and is a good solvent with wide application. Except for the halogenated hydrocarbon, can be optionally mixed with water and most organic solvents. Has good dissolving capacity and chemical stability for various organic compounds and inorganic compounds.

The alkaline cleaning agent takes benzyl alcohol as a main cleaning active ingredient, is assisted by combined action of ethylene glycol and N, N-dimethylformamide, contains strong alkali and water to prepare the alkaline water-based cleaning agent, is controlled in a specific composition proportion, has strong cleaning capability, is not only used for strong cleaning capability of coating liquid, but also has strong cleaning capability of paint slag in a pipeline, and can be suitable for cleaning the pipeline with serious slag bonding.

Particularly, the alkaline cleaning agent is particularly suitable for cleaning paint residues of pipelines for automobile coating paint, has strong cleaning force and short cleaning time, saves manpower and labor time and provides cleaning efficiency. It is understood that in one example, the main components of the applicable automotive coating paint are acrylic resin, amino resin, pigment filler, and the like.

Further, the above alkaline cleaner has a low solvent content, and benzyl alcohol and ethylene glycol have boiling points of about 200 ℃, and N, N-dimethylformamide, which is a small content, is also at 150 ℃ or higher, so that the VOC (volatile organic substance) emission of the alkaline cleaner is low.

In addition, the components of the alkaline cleaning agent have wide sources, are economical and practical, and avoid the problems of high price and high cost of the cleaning agent which takes N, N-dimethylformamide as a main cleaning component.

In some embodiments, the alkaline cleaning agent comprises 2 to 5 parts by weight of strong base, 10 to 20 parts by weight of ethylene glycol, 70 to 80 parts by weight of benzyl alcohol, 1.5 to 3 parts by weight of N, N-dimethylformamide and 3 to 5 parts by weight of water. The skilled person of the present invention has found that by further controlling the components of the above alkaline cleaner within this ratio range, the cleaning ability of the alkaline cleaner can be further improved.

Further, in the alkaline cleaning agent, by weight, 2-5 parts of strong base, 16-17 parts of ethylene glycol, 74-76 parts of benzyl alcohol, 1.5-2 parts of N, N-dimethylformamide and 3-5 parts of water. The skilled person of the present invention has found that by further controlling the components of the above alkaline cleaner within this ratio range, the cleaning ability of the alkaline cleaner can be further improved.

Furthermore, in the alkaline cleaning agent, by weight, 2-5 parts of strong base, 16-17 parts of ethylene glycol, 74-76 parts of benzyl alcohol, 1.5-2 parts of N, N-dimethylformamide and 3-5 parts of water; and the total weight part of the strong base, the glycol, the benzyl alcohol, the N, N-dimethylformamide and the water is 100 parts. In other words, in the alkaline cleaner, the content of the strong base is 2 to 5 percent, the content of the ethylene glycol is 16 to 17 percent, the content of the benzyl alcohol is 74 to 76 percent, the content of the N, N-dimethylformamide is 1.5 to 2 percent, and the content of the water is 3 to 5 percent.

Further, in the above-mentioned alkaline cleaner, 3 parts of a strong base, 16.5 parts of ethylene glycol, 75 parts of benzyl alcohol, 1.5 parts of N, N-dimethylformamide and 4 parts of water were used. The skilled person of the present invention has found that by further controlling the above-mentioned components of the alkaline cleaner in such proportions, the cleaning ability of the alkaline cleaner can be further improved.

In some of these embodiments, the strong base is at least one of sodium hydroxide and potassium hydroxide. It is understood that these two strong bases have good solubility in the above-described system of alkaline cleaners and are low in cost. More preferably, the strong base is potassium hydroxide.

The invention also provides a preparation method of the alkaline cleaning agent, which comprises the following steps:

step S10: the components of the alkaline cleaner according to any one of the above are supplied as raw materials.

In some embodiments, the alkaline cleaning agent comprises the following components in parts by weight: 1-5 parts of strong base, 10-20 parts of ethylene glycol, 70-80 parts of benzyl alcohol, 1-3 parts of N, N-dimethylformamide and 1-5 parts of water.

Step S20: mixing the above materials.

In order to promote the complete dissolution of the components, in some embodiments, the step S20 of mixing the raw materials uniformly includes the following steps S21 to S22:

step S21: mixing and dissolving strong base, water and glycol;

step S22: then adding benzyl alcohol and N, N-dimethylformamide, and uniformly mixing.

Further, step S21 is performed under a stirring state; because the dissolution of the potassium hydroxide is an exothermic reaction, cooling water can be used for cooling in the dissolution process so as to ensure the safety of production. In a specific example, step S21 is performed in a jacketed reaction vessel, in which cooling water is provided for cooling.

Further, step S22 is also performed under stirring, and after the temperature of the above-mentioned heating dissolution is lowered to room temperature, benzyl alcohol and N, N-dimethylformamide are added and mixed uniformly.

The preparation method is simple in process, and the prepared alkaline cleaning agent has strong cleaning capability, is not only used for cleaning coating liquid, but also has strong cleaning capability for paint slag in pipelines, and can be suitable for cleaning pipelines with serious slag bonding.

Use of an alkaline cleaner as defined in any of the preceding claims for cleaning paints.

The alkaline cleaning agent not only can be used for cleaning the coating liquid with strong cleaning capability, but also has strong cleaning capability on paint slag in the pipeline, and can be suitable for cleaning the pipeline with serious slag bonding.

The invention also provides a method for cleaning the pipeline for the coating, which adopts any one of the alkaline cleaning agents to clean the pipeline.

Specifically, the alkaline cleaning agent is added into the pipeline to fully act with the pipeline, and then the pipeline is cleaned.

The following are specific examples.

Example 1

(1) Weighing the following raw materials in parts by weight: 3g of strong base, 16.5g of ethylene glycol, 75g of benzyl alcohol, 1.5g of N, N-dimethylformamide and 4g of water; the strong base is potassium hydroxide.

(2) Under the stirring state, sequentially adding the weighed strong base, water and glycol into a reaction kettle with a jacket, and dissolving to obtain a component a;

(3) and (3) under the stirring state, after the temperature of the component a is reduced to room temperature, adding the weighed benzyl alcohol and N, N-dimethylformamide into the component a, and uniformly mixing to obtain the alkaline cleaning agent.

Example 2

Example 2 was the same as example 1 except that the proportions of the component materials were different. The method comprises the following specific steps:

(1) weighing the following raw materials in parts by weight: 3g of strong base, 16.5g of ethylene glycol, 73.5g of benzyl alcohol, 3g of N, N-dimethylformamide and 4g of water; the strong base is potassium hydroxide.

(2) Under the stirring state, sequentially adding the weighed strong base, water and glycol into a reaction kettle with a jacket, and dissolving to obtain a component a;

(3) and (3) under the stirring state, after the temperature of the component a is reduced to room temperature, adding the weighed benzyl alcohol and N, N-dimethylformamide into the component a, and uniformly mixing to obtain the alkaline cleaning agent.

Example 3

Example 3 the procedure was the same as example 1 except that the proportions of the component materials were different. The method comprises the following specific steps:

(1) weighing the following raw materials in parts by weight: 2g of strong base, 20g of ethylene glycol, 70g of benzyl alcohol, 3g of N, N-dimethylformamide and 5g of water; the strong base is potassium hydroxide.

(2) Under the stirring state, sequentially adding the weighed strong base, water and glycol into a reaction kettle with a jacket, and dissolving to obtain a component a;

(3) and (3) under the stirring state, after the temperature of the component a is reduced to room temperature, adding the weighed benzyl alcohol and N, N-dimethylformamide into the component a, and uniformly mixing to obtain the alkaline cleaning agent.

Example 4

Example 4 was the same as example 1 except that the proportions of the component materials were different. The method comprises the following specific steps:

(1) weighing the following raw materials in parts by weight: 5g of strong base, 10g of ethylene glycol, 80g of benzyl alcohol, 2g of N, N-dimethylformamide and 3g of water; the strong base is potassium hydroxide.

(2) Under the stirring state, sequentially adding the weighed strong base, water and glycol into a reaction kettle with a jacket, and dissolving to obtain a component a;

(3) and (3) under the stirring state, after the temperature of the component a is reduced to room temperature, adding the weighed benzyl alcohol and N, N-dimethylformamide into the component a, and uniformly mixing to obtain the alkaline cleaning agent.

Comparative example 1

Comparative example 1 and example 1 the procedure was the same except that the component materials contained no DMF and the ratio of the component materials was different. The method comprises the following specific steps:

(1) weighing the following raw materials in parts by weight: 3g of strong base, 16.5g of ethylene glycol, 76.5g of benzyl alcohol and 4g of water; the strong base is potassium hydroxide.

(2) Under the stirring state, sequentially adding the weighed strong base, water and glycol into a reaction kettle with a jacket, and dissolving to obtain a component a;

(3) and (3) under the stirring state, after the temperature of the component a is reduced to room temperature, adding the weighed benzyl alcohol and N, N-dimethylformamide into the component a, and uniformly mixing to obtain the alkaline cleaning agent.

Comparative example 2

Comparative example 2 is the same as example 1 except that the proportions of the component materials are different. The method comprises the following specific steps:

(1) weighing the following raw materials in parts by weight: 3g of strong base, 8.5g of ethylene glycol, 83g of benzyl alcohol, 1.5g of N, N-dimethylformamide and 4g of water; the strong base is potassium hydroxide.

(2) Under the stirring state, sequentially adding the weighed strong base, water and glycol into a reaction kettle with a jacket, and dissolving to obtain a component a;

(3) and (3) under the stirring state, after the temperature of the component a is reduced to room temperature, adding the weighed benzyl alcohol and N, N-dimethylformamide into the component a, and uniformly mixing to obtain the alkaline cleaning agent.

Comparative example 3

Comparative example 3 is the same as example 1 except that the proportions of the component materials are different. The method comprises the following specific steps:

(1) weighing the following raw materials in parts by weight: 3g of strong base, 24.5g of ethylene glycol, 67g of benzyl alcohol, 1.5g of N, N-dimethylformamide and 4g of water; the strong base is potassium hydroxide.

(2) Under the stirring state, sequentially adding the weighed strong base, water and glycol into a reaction kettle with a jacket, and dissolving to obtain a component a;

(3) and (3) under the stirring state, after the temperature of the component a is reduced to room temperature, adding the weighed benzyl alcohol and N, N-dimethylformamide into the component a, and uniformly mixing to obtain the alkaline cleaning agent.

The alkaline cleaners of examples 1 to 4 and comparative examples 1 to 3 were prepared from the following raw materials in the following proportions, wherein the unit is g:

the alkaline cleaning agents of examples 1 to 4 and comparative examples 1 to 3 were used to evaluate the solubility of the same paint slag, so as to evaluate the cleaning ability of the same paint slag. Specifically, a stainless steel plate with paint slag accumulated is adopted for testing, and the paint slag on the stainless steel plate has the same components as the paint slag in the pipeline and is used for simulating and evaluating the dissolution performance of the paint slag in the pipeline. The main components of the automobile coating paint corresponding to the paint slag are acrylic resin, amino resin, pigment and filler and the like.

The specific test steps of the solubility of the paint slag in the pipeline are as follows:

(1) wiping a stainless steel plate with the thickness of 100mm multiplied by 50mm by alcohol; weighing m₀

(2) The detected paint is scraped and coated on a stainless steel plate, and the area of the coating surface accounts for about half of the area of the stainless steel plate;

(3) placing the stainless steel plate coated with the coating in an oven at 80 ℃, and baking for 5 min; cooling to obtain a test plate; weighing m₁；

(4) After the cooled test panel was immersed in an alkaline cleaner for 30min (normal temperature), the test sample was taken out, and a photograph was taken to compare the peeling of the coating film (at this time, the next cleaning step was not performed). The photographs of the obtained dissolution results are shown in fig. 1 and 2. In FIG. 1, A1 to A2 correspond to photographs after cleaning with the alkaline cleaner of examples 1 to 2, respectively; in FIG. 2, D1 to D3 correspond to photographs of the alkali cleaning agent of comparative examples 1 to 3 after cleaning.

In addition, a simultaneous comparison was made with the currently used cleaning agent in production (i.e., comparative example 4), the test method was as above, and the test results are shown in D4 of fig. 2. The cleaning agent is a mixed solution of ethylene glycol butyl ether, dimethylethanolamine and water, wherein the mass ratio of the ethylene glycol butyl ether to the dimethylethanolamine to the water is 0.95:0.05 (4-9).

As can be seen from FIGS. 1 and 2, the brightness of the stainless steel plate obtained by cleaning with the alkaline cleaning agent of examples 1-2 is better than that of the stainless steel plate obtained by cleaning with the alkaline cleaning agent of comparative examples 1-4; that is, the coating film on the corresponding stainless steel plate was more peeled off, and the cleaning ability of the corresponding alkaline cleaning agent was stronger.

The alkaline cleaners of examples 1 to 4 and comparative examples 1 to 4 were subjected to cleaning force test statistics. Cleaning force testThe method comprises the following specific steps: after the step of taking out a test sample and taking a picture in the step (4) of the specific test of the solubility of the paint slag in the pipeline, dropwise adding 2mL of alcohol at a position 1-2 cm above a paint film by adopting a wash bottle to clean and remove the paint slag and the solvent on the surface; then baking at 80 deg.C for 5 min; and weigh m₂(ii) a The cleaning force is calculated as follows:

the results of the tests to obtain the above-described cleaning force test are shown in the following table.

As can be seen from the above table, the alkaline cleaners of examples 1 to 3 are superior in cleaning ability to those of comparative examples 1 to 4.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (10)

1. The alkaline cleaning agent is characterized by comprising the following components in parts by weight: 1-5 parts of strong base, 10-20 parts of ethylene glycol, 70-80 parts of benzyl alcohol, 1-3 parts of N, N-dimethylformamide and 1-5 parts of water.

2. The alkaline cleaning agent according to claim 1, wherein the alkali is 2 to 5 parts by weight, the glycol is 10 to 20 parts by weight, the benzyl alcohol is 70 to 80 parts by weight, the N, N-dimethylformamide is 1.5 to 3 parts by weight, and the water is 3 to 5 parts by weight.

3. The alkaline cleaning agent according to claim 1, wherein the alkali is 2 to 5 parts by weight, the glycol is 16 to 17 parts by weight, the benzyl alcohol is 74 to 76 parts by weight, the N, N-dimethylformamide is 1.5 to 2 parts by weight, and the water is 3 to 5 parts by weight.

4. The alkaline cleaning agent according to claim 3, wherein the total weight of the strong base, the glycol, the benzyl alcohol, the N, N-dimethylformamide and the water is 100 parts.

5. The alkaline cleaner according to claim 1, wherein the alkali is 3 parts, the glycol is 16.5 parts, the benzyl alcohol is 75 parts, the N, N-dimethylformamide is 1.5 parts, and the water is 4 parts.

6. The alkaline cleaning agent according to any one of claims 1 to 5, wherein the strong base is at least one of sodium hydroxide and potassium hydroxide.

7. The preparation method of the alkaline cleaning agent is characterized by comprising the following steps:

providing raw materials according to the components of the alkaline cleaner as claimed in any one of claims 1 to 6;

mixing the above materials.

8. The method for producing an alkaline cleaner as claimed in claim 7, wherein the step of uniformly mixing the respective raw materials comprises the steps of:

and mixing and dissolving the strong base, the water and the ethylene glycol, then adding the benzyl alcohol and the N, N-dimethylformamide, and uniformly mixing.

9. Use of the alkaline cleaner as claimed in any one of claims 1 to 6 for cleaning a coating material.

10. A method for cleaning a pipeline for paint, characterized in that the pipeline is cleaned by the alkaline cleaner as claimed in any one of claims 1 to 6.

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