阅读说明：本技术 一种液体还原清洗剂及其制备方法和应用 (Liquid reduction cleaning agent and preparation method and application thereof ) 是由 赵红阳 刘利苹 陈玮 邢燕燕 吴通达 陈志勇 崔随国 郑凤云 闫勇 刘千河 魏丽 于 2020-12-31 设计创作，主要内容包括：本发明属于还原清洗剂技术领域,具体涉及一种液体还原清洗剂及其制备方法和应用。本发明充分利用了二氧化硫脲和吊白块(甲醛合次硫酸氢钠)相结合的综合优势,制备一种还原能力强、溶解度高的液体还原清洗剂,所述液体还原清洗剂,由二氧化硫脲、吊白块和水配制而成,各组分的质量百分比为：二氧化硫脲1%-20%、吊白块10%-40%,余量为纯水,所述还原清洗剂的pH值为4-10,所述液体还原清洗剂在使用时,需要的碱性由吊白块提供,酸性由二氧化硫脲提供。还原清洗无需调节pH值,适用范围广,清洗后不需要再次中和。经过本发明所述液体还原清洗剂清洗后,涤纶织物以及涤棉混纺织物的干湿摩擦牢度由普通的3-4级提升到4-5级。(The invention belongs to the technical field of reductive cleaning agents, and particularly relates to a liquid reductive cleaning agent, and a preparation method and application thereof. The invention fully utilizes the comprehensive advantages of the combination of thiourea dioxide and sodium formaldehyde sulfoxylate, and prepares a liquid reducing cleaning agent with strong reducing capability and high solubility, wherein the liquid reducing cleaning agent is prepared from thiourea dioxide, sodium formaldehyde sulfoxylate and water, and the mass percentages of the components are as follows: 1-20% of thiourea dioxide, 10-40% of sodium formaldehyde sulfoxylate and the balance of pure water, wherein the pH value of the reducing cleaning agent is 4-10, and when the liquid reducing cleaning agent is used, the needed alkalinity is provided by the sodium formaldehyde sulfoxylate, and the acidity is provided by the thiourea dioxide. The reduction cleaning does not need to adjust the pH value, the application range is wide, and the cleaning does not need to be neutralized again. After the cleaning by the liquid reducing cleaning agent, the dry and wet rubbing fastness of the polyester fabric and the polyester-cotton blended fabric is improved to 4-5 levels from the common 3-4 levels.)

1. The liquid reduction cleaning agent is characterized by being prepared from thiourea dioxide, sodium formaldehyde sulfoxylate and water, wherein the mass percent of each component is as follows: 1-20% of thiourea dioxide, 10-40% of sodium formaldehyde sulfoxylate and the balance of pure water, wherein the pH value of the reducing cleaning agent is 4-10.

2. The liquid reducing cleaner according to claim 1, wherein the pH of the reducing cleaner is 5 to 8.

3. The liquid reducing detergent as claimed in claim 1, wherein the liquid reducing detergent comprises the following components in percentage by mass: 5-15% of thiourea dioxide, 25-35% of sodium formaldehyde sulfoxylate and the balance of pure water.

4. The liquid reducing cleaning agent as claimed in claim 1, further comprising a reducing assistant, wherein the reducing assistant comprises the following components in percentage by mass: 1 to 10 percent; the reduction auxiliary agent is one of sodium oxalate, sodium sulfite, sodium thiosulfate and sodium formate.

5. The liquid reducing cleaning agent according to claim 1 or 4, further comprising an essence, wherein the essence comprises the following components in percentage by mass: 0.1-1% of essence, wherein the essence is one of furfuryl alcohol, furan formic ether, furan methanol ester and furan acrylic ester.

6. A method for preparing a liquid reductive cleaner as claimed in any one of claims 1 to 3, comprising the steps of:

(1) dissolving the sodium formaldehyde sulfoxylate blocks with corresponding mass percentage in pure water at room temperature and normal pressure for later use;

(2) when in use, thiourea dioxide with corresponding mass percentage is added and evenly stirred to obtain the liquid reduction cleaning agent.

7. A method for preparing a liquid reductive cleaner as claimed in claim 5, comprising the steps of:

(1) at room temperature and normal pressure, taking the reduction additive and the essence according to the corresponding mass percentage, dissolving the reduction additive and the essence in pure water, stirring, naturally dissolving, adding the rongalite according to the corresponding mass percentage, and dissolving for later use;

(2) when in use, thiourea dioxide with corresponding mass percentage is added and evenly stirred to obtain the liquid reduction cleaning agent.

8. Use of the liquid reductive cleaner as claimed in claim 1 or 4 for reductive cleaning of fabrics printed with disperse dyes.

9. Use according to claim 7, wherein the fabric is a polyester fabric or a polyester-cotton blend fabric.

10. The reductive cleaning method for fabrics printed by disperse dyes by using the liquid reductive cleaner as claimed in claim 1 or 4, which is characterized by comprising the following steps:

a) before use, thiourea dioxide in corresponding mass percentage is added into a solution containing the rongalite in corresponding mass percentage to prepare the liquid reduction cleaning agent;

b) after the fabric is dyed by the disperse dye, the pH value is not adjusted, the reductive cleaner is directly added for cleaning, and the fabric is dried after cleaning.

Technical Field

The invention belongs to the technical field of reductive cleaning agents, and particularly relates to a liquid reductive cleaning agent, and a preparation method and application thereof.

Background

The reduction cleaning process is to remove the floating color of disperse dye which does not enter or enter a part of polyester fiber when dyeing the polyester or blended fabric, so as to prevent the floating color from being stained on other clothes or skin through friction in the process of using clothes, and the process can be understood as a slight color stripping process. At present, sodium hydrosulfite (commonly called sodium hydrosulfite), thiourea dioxide or sodium formaldehyde sulfoxylate (commonly called sodium formaldehyde sulfoxylate) is mainly used as a common reduction cleaning agent in the market.

The sodium hydrosulfite is called as sodium hydrosulfite because the reduction potential is moderate and the sodium hydrosulfite is not easy to excessively reduce when the vat dye is used for dyeing, and although the sodium hydrosulfite is called as sodium hydrosulfite, the defects are obvious when the sodium hydrosulfite is used for stripping and reduction cleaning: the reaction is easy to react with oxygen in air and water, the utilization efficiency is low, and spontaneous combustion decomposition is easy to occur in the reaction process, a large amount of toxic irritant gases such as hydrogen sulfide smelly eggs, sulfur dioxide and the like are released, and the safety of human bodies and equipment is not ensured. Therefore, a substitute for sodium hydrosulfite needs to be found.

Thiourea dioxide has higher reducing power as a substitute of sodium hydrosulfite, has high reduction potential, is not easy to oxidize and decompose as an organic acid, and can be decomposed into methyl ether sulfinic acid and further into hyposulfite only under the condition of alkaline reduction cleaning. However, with the continuous improvement of the industrial automation requirements, the characteristic of high reduction potential of thiourea dioxide becomes a disadvantage on the contrary, because under the condition of humidity and high temperature of a printing and dyeing mill, the liquid conveying is more stable and the cost performance is low than that of solid conveying, and meanwhile, the solubility of the thiourea dioxide at room temperature is only 2g, so that the thiourea dioxide is difficult to be compounded into liquid for pumping to a production line for use.

The formaldehyde residue in the sodium formaldehyde sulfoxylate is not beneficial to human bodies, the excessive formaldehyde residue on fabrics is easy to cause, the original potential is low, the reduction capability is poor, the odor of eggs smelled by hydrogen sulfide is generated, the sodium formaldehyde sulfoxylate is generally not used as an optimal reduction cleaning agent, but the solubility is high, and liquid with the concentration of 30-60% can be formed during preparation. Therefore, the rongalite is also prepared into an acidic reduction cleaning agent for use in the prior art, for example, a stable reduction cleaning agent after liquid disperse dyeing is disclosed in the Chinese patent with the publication number of CN102808340B, and the patent mentions that the reduction cleaning agent has good effect and certain fastness and can achieve the cleaning effect of the traditional reduction cleaning process, but the reduction cleaning agent has the problems of low reduction potential, poor reduction cleaning effect, short storage time and the like in practical application.

In addition, chinese patent No. CN102409561B discloses a method for dyeing and printing fabrics with vat dyes, which relates to vat cleaners containing thiourea dioxide, but simply mixes several reducing agents together and the required reduction potential is not high when the vat dyes are dyed, because the formula involved in this patent can further destroy the leuco body of the vat dye if the reduction potential is too high, resulting in over-reduction due to decomposition of dye molecules and irreversible change of shade. When the reduction cleaning is carried out, the higher the required reduction potential is, the better the reduction potential is, the purpose is to decompose and destroy dye molecules into water-soluble small molecules, and the small molecules are irreversibly changed to prevent the dye molecules from being reversely attached to the fabric. Therefore, the method of this patent is not stable for reductive cleaning although it can be used for vat dye dyeing.

Based on the current situation, the invention aims to develop the cleaning agent with strong reducing capability and high solubility so as to solve the problems existing in the use of the reducing cleaning agent in the prior art.

Disclosure of Invention

Aiming at the defects in the prior art, the first purpose of the invention is to provide a liquid reducing cleaning agent with strong reducing capability and high solubility.

The second purpose of the invention is to provide a preparation method of the liquid reduction cleaning agent.

A third object of the invention is to provide the use of said liquid reducing cleaning agent.

Based on the purpose, the invention adopts the following technical scheme:

a liquid reduction cleaning agent is mainly prepared from thiourea dioxide, sodium formaldehyde sulfoxylate and water, and comprises the following components in percentage by mass: 1-20% of thiourea dioxide, 10-40% of sodium formaldehyde sulfoxylate and the balance of pure water, wherein the pH value of the reducing cleaning agent is 4-10.

Further, the pH value of the reducing cleaning agent is 5-8, and is preferably 7.

Further, the liquid reducing cleaning agent comprises the following components in percentage by mass: 5-15% of thiourea dioxide, 25-35% of sodium formaldehyde sulfoxylate and the balance of pure water.

Preferably, the liquid reducing cleaning agent comprises the following components in percentage by mass: 10% of thiourea dioxide, 30% of sodium formaldehyde sulfoxylate and the balance of pure water, wherein the optimal mass ratio of the thiourea dioxide to the sodium formaldehyde sulfoxylate is 1: 3.

Further, the liquid reducing cleaning agent also comprises a reducing auxiliary agent, and the reducing auxiliary agent comprises the following components in percentage by mass: 1 to 10 percent.

Further, the reduction auxiliary agent is one of sodium oxalate, sodium sulfite, sodium thiosulfate and sodium formate.

Further, the liquid reducing cleaning agent also comprises essence, and the essence comprises the following components in percentage by mass: 1 to 10 percent.

Specifically, the essence is one of furfuryl alcohol, furan formic ether, furan methanol ester and furan acrylic ester.

The preparation method of the liquid reducing cleaning agent comprises the following steps:

(1) at room temperature and normal pressure, taking the reduction additive and the essence according to the corresponding mass percentage, dissolving the reduction additive and the essence in pure water, stirring, naturally dissolving, adding the rongalite according to the corresponding mass percentage, and dissolving for later use; or when the liquid reducing cleaning agent does not contain reducing auxiliary agent and essence, the sodium formaldehyde sulfoxylate with corresponding mass percentage is directly dissolved in pure water for standby;

(2) when in use, thiourea dioxide with corresponding mass percentage is added and evenly stirred to obtain the liquid reduction cleaning agent.

The reduction auxiliary agent plays a role in removing oxygen in water and preventing oxygen from oxidizing the rongalite and thiourea dioxide, the auxiliary agent can be not added during preparation, or the rongalite and the thiourea dioxide are protected against oxidation in a nitrogen introducing mode after preparation, and in addition, the rongalite and the thiourea dioxide can be protected against oxidation in a mode of replacing pure water with deoxygenated water during preparation.

The essence is added during preparation to cover the taste of hydrogen sulfide and urea generated by decomposing thiourea dioxide and sodium formaldehyde sulfoxylate and ammonia generated by decomposing the hydrogen sulfide and urea, is water-soluble, cannot be stained with fabrics, and is convenient to wash away.

The invention also provides application of the liquid reductive cleaner in reductive cleaning of fabrics printed by disperse dyes.

The fabric is a polyester fabric or a polyester-cotton blended fabric.

The method for reducing and cleaning the fabric printed and dyed by the disperse dye by using the liquid reducing cleaning agent comprises the following steps:

a) before use, thiourea dioxide in corresponding mass percentage is added into a solution (or also contains a reduction additive and essence) containing the rongalite in corresponding mass percentage to prepare the liquid reduction cleaning agent;

b) after the fabric is dyed by the disperse dye, the pH value is not adjusted, the reductive cleaning agent is directly added for cleaning, no auxiliary agent is added for neutralization after cleaning, and drying is carried out after cleaning.

Further, if the color of the fabric is darker after the disperse dye dyeing is finished, water exchange is needed, and if the color of the fabric is lighter during the disperse dye dyeing process, water exchange is not needed.

The invention fully utilizes the comprehensive advantages of the combination of thiourea dioxide and sodium formaldehyde sulfoxylate, and simultaneously the prepared liquid reducing cleaning agent can offset the disadvantages of the thiourea dioxide and the sodium formaldehyde sulfoxylate to obtain better performance and use effect.

The liquid reducing cleaning agent has the advantages that the thiourea dioxide reducing potential is overall strong, the excessive reducing potential is easily caused, the reducing potential of the sodium formaldehyde sulfoxylate is overall weak, and the reducing potential of the liquid reducing cleaning agent obtained by combining the thiourea dioxide reducing potential and the sodium formaldehyde sulfoxylate is moderate, so that the reducing potential layering sense is formed.

The second advantage is that the thiourea dioxide reduction potential is low at the initial stage and high at the final stage; the initial reduction potential of the sodium formaldehyde sulfoxylate is high, the final reduction potential is high, and the reduction potential of the sodium formaldehyde sulfoxylate is stable in the initial final reduction potential after the sodium formaldehyde sulfoxylate and the sodium formaldehyde sulfoxylate are combined to obtain the liquid reduction cleaning agent.

The liquid reducing cleaning agent has the advantages that the stability of thiourea dioxide is strong, the stability of the sodium formaldehyde sulfoxylate is weak, and the stability of the liquid reducing cleaning agent obtained by combining the thiourea dioxide and the sodium formaldehyde sulfoxylate is moderate.

The advantage IV is that the thiourea dioxide solubility is low, the sodium formaldehyde sulfoxylate solubility is high, and the liquid reducing cleaning agent obtained by combining the thiourea dioxide and the sodium formaldehyde sulfoxylate has moderate solubility.

Fifth, thiourea dioxide is high in price, the sodium formaldehyde sulfoxylate is low in price, and the liquid reducing cleaning agent obtained by combining the thiourea dioxide and the sodium formaldehyde sulfoxylate is high in cost performance.

And the acid-base performance of the thiourea dioxide and the acid-base performance can realize advantage complementation, the thiourea dioxide is acidic and has reducing capability under an alkaline condition, the sodium formaldehyde sulfoxylate is alkaline and has reducing capability under an acidic condition, and the liquid reducing cleaning agent obtained by combining the thiourea dioxide and the sodium formaldehyde sulfoxylate can be reduced and cleaned in an acidic alkaline or even neutral state without adding an auxiliary agent for neutralization.

The advantage seven is that thiourea dioxide has high solubility under alkaline condition, and the sodium formaldehyde sulfoxylate can provide alkalinity, so the liquid reduction cleaning agent obtained after the thiourea dioxide and the sodium formaldehyde sulfoxylate are combined can increase the solubility of the diurea, and the thiourea dioxide can be prepared into high-concentration solution.

The advantage eight, when using, liquid reduction cleaner storage time is long, can dispose in advance, also can dispose a few hours before using, and the technology suitability is stronger.

Compared with the prior art, the invention has the beneficial effects that:

1. the thiourea dioxide reduction capability is kept for a long time, but the reduction potential is increased slowly, so that the reaction degree is not improved enough in the initial stage, and the reaction of the rongalite is quicker in the initial stage, but the reaction force is not enough. Therefore, the invention not only makes up the defect of low solubility of thiourea dioxide, but also makes up the defect of poor reducing capability of the sodium formaldehyde sulfoxylate, prepares the liquid reducing cleaning agent with strong reducing capability and high effective components, and is chemically compounded different from the principle of physical mixing adopted in the prior art (the sodium sulfite rongalite composite acidic reducing cleaning agent, the preparation method and the application thereof, and the publication number is CN 107956169A).

2. When the liquid reducing cleaning agent is used, the needed alkalinity is provided by the sodium formaldehyde sulfoxylate, and the acidity is provided by thiourea dioxide.

3. The reduction cleaning does not need to adjust the pH value, the application range is wide, and the cleaning does not need to be neutralized again.

4. After being cleaned by the liquid reducing cleaning agent, the dry-wet rubbing fastness of the polyester fabric and the polyester-cotton blended fabric is improved to 4-5 from the common 3-4 level (refer to the national standard GB/T3920-2008 'color fastness to rubbing of textile color fastness test').

Detailed Description

In order to make the technical purpose, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention are further described with reference to specific examples, which are intended to explain the present invention and are not to be construed as limiting the present invention, and those who do not specify a specific technique or condition in the examples follow the techniques or conditions described in the literature in the art or follow the product specification.

Example 1

A liquid reducing cleaning agent comprises the following components in percentage by mass: 10% of thiourea dioxide, 30% of sodium formaldehyde sulfoxylate, 5% of sodium sulfite (reduction aid), 1% of furfuryl alcohol (essence) and the balance of pure water, wherein the pH value of the reduction cleaning agent is adjusted to be 8 when the reduction cleaning agent is used.

The preparation method of the liquid reducing cleaning agent comprises the following specific steps:

(1) at room temperature and normal pressure, taking the reduction additive and the essence according to the corresponding mass percentage, dissolving the reduction additive and the essence in pure water, stirring, naturally dissolving, adding the rongalite according to the corresponding mass percentage, and dissolving for later use;

(2) when in use, thiourea dioxide with corresponding mass percentage is added and evenly stirred to obtain the liquid reduction cleaning agent.

Example 2

A liquid reducing cleaning agent comprises the following components in percentage by mass: thiourea dioxide 20%, sodium formaldehyde sulfoxylate 30%, oxalic acid (reducing agent) 5%, the balance being pure water, and the pH value of the reducing cleaning agent is adjusted to 4 when the reducing cleaning agent is used.

The preparation method of the liquid reducing cleaning agent comprises the following specific steps:

(1) at room temperature and normal pressure, taking the reduction aid with corresponding mass percent, dissolving the reduction aid in pure water, stirring, naturally dissolving, adding the rongalite with corresponding mass percent, and dissolving for later use;

(2) when in use, thiourea dioxide with corresponding mass percentage is added and evenly stirred to obtain the liquid reduction cleaning agent.

Example 3

A liquid reducing cleaning agent comprises the following components in percentage by mass: 10% of thiourea dioxide, 20% of sodium formaldehyde sulfoxylate and the balance of pure water, and the pH value of the reducing cleaning agent is adjusted to 7 when the reducing cleaning agent is used.

The preparation method of the liquid reducing cleaning agent comprises the following specific steps:

(1) dissolving the sodium formaldehyde sulfoxylate blocks with corresponding mass percentage in pure water at room temperature and normal pressure for later use;

(2) when in use, thiourea dioxide with corresponding mass percentage is added and evenly stirred to obtain the liquid reduction cleaning agent.

Test examples

After the fabric is dip-dyed with 4% o.w.f (based on the weight of the fabric) disperse dye C.I.56 by using the dried fabric (polyester 100%) (dip-dyeing time is 30min, dip-dyeing temperature is 130 ℃), the dip-dyed fabric is obtained. The liquid reducing cleaning agent in the embodiment 3 of the invention is used for cleaning the fabric after dip dyeing, the method in the color fastness to rubbing of the national standard GB/T3920-2008 textile color fastness test is used for detecting the color fastness to washing, and the same cleaning method is adopted as a control group by adding thiourea dioxide, sodium formaldehyde sulfoxylate and sodium hydrosulfite.

The specific using method of the liquid reducing cleaning agent comprises the following steps:

a) before use, thiourea dioxide in corresponding mass percentage is added into a solution containing the rongalite in corresponding mass percentage to prepare the liquid reduction cleaning agent;

b) after dyeing the polyester fabric or the polyester-cotton blended fabric by the disperse dye, directly adding the reductive cleaning agent for cleaning without adjusting the pH value, wherein during cleaning, if the color of the polyester fabric or the polyester-cotton blended fabric is darker after dyeing of the disperse dye, water is required to be changed, if the color of the polyester fabric or the polyester-cotton blended fabric is lighter in the dyeing process of the disperse dye, water is not required to be changed, and after cleaning, an auxiliary agent is not required to be added for neutralization, and after cleaning, drying is carried out. Specific results are shown in table 1.

Table 1.

Thiourea dioxide is firstly decomposed under alkaline conditions, and the specific reaction is as follows: NH: C (SO)₂H)•NH₂+2NaOH→H₂NC(∶O)NH₂+Na₂SO₂+H₂O; the rongalite is decomposed by heating, and the concrete reaction is as follows: NaHSO₂•CH₂O•2H₂O→NaHSO₂+ CH₂O+ H₂O。

From a comparison of the data in table 1, it can be seen that:

thiourea dioxide can release hyposulphite ions under alkaline conditions, and is relatively stable. The rongalite can release hydrosulfite ions only by heating and can be further decomposed under acidic conditions. The molecular weight of thiourea dioxide is 108.12, the molecular weight of rongalite is 118.10, the content of thiourea dioxide is generally 99%, and the content of rongalite is 98%, which shows that the thiourea dioxide has stronger reducing capability under the same mass. The thiourea dioxide and the sodium formaldehyde sulfoxylate can be used together to assist each other to form a relatively stable and layered reduction system.

From table 1 it can be derived: the fastness of the thiourea dioxide and the sodium hydrosulfite after the cleaning of the fabric can be improved under the alkaline condition, and the fastness of the sodium hydrosulfite after the cleaning of the fabric can be improved under the acidic condition. Therefore, the liquid reductive cleaner disclosed by the invention not only can realize effective reductive cleaning of the fabric, but also can effectively improve the fastness of the fabric dyed by the disperse dye, improve the color brightness degree of the fabric, and has a good application effect.

Finally, it should be noted that: the above embodiments are merely illustrative and not restrictive of the technical solutions of the present invention, and any equivalent substitutions and modifications or partial substitutions made without departing from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.