Low-foam easy-to-wash laundry detergent and preparation method thereof

Abstract

The invention discloses a low-foam easy-to-wash laundry detergent and a preparation method thereof, and relates to the technical field of daily chemicals. Hydrogenated potassium cocoate soap and castor oil polyoxyethylene ether sodium carboxylate are used as soap defoaming agents, and acetic acid is used for providing a weak acid system for a washing environment, so that calcium and magnesium ions in hard water cannot be deposited, and further calcium and magnesium soap insoluble in water is generated, so that the effects of low foam and easy flushing are realized; the defoaming agent is compounded with an organic silicon defoaming agent and a polyether defoaming agent, the organic silicon defoaming agent is rapidly dissolved in hard water and a high-temperature environment to generate silicate, and silicon dioxide in the organic silicon defoaming agent serves as a needle point for puncturing foam, so that the defoaming property is enhanced; wherein the polyether defoaming agent and the castor oil polyoxyethylene ether sodium carboxylate enhance the water solubility of the organic silicon defoaming agent and the soap defoaming agent in the laundry detergent and reduce the strength of a foam liquid film, so that the defoaming effect is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of daily chemical products, and specifically to a low-foam and easy-to-rinse laundry detergent and a preparation method thereof. Background Art

[0002] Laundry detergent is the fastest-growing clothing detergent at present. It has thorough decontamination, is easy to rinse, has a neutral pH value, is mild and does not hurt hands, does not damage clothing fibers, and is convenient for adding effective ingredients such as sterilization, fluffing, and softening. It has gradually replaced traditional washing powders, soaps, etc. With its many advantages, its market share has gradually increased in recent years in China. Laundry detergent occupies the main market of washing products with its own advantages, and concentrated laundry detergent has become the main trend of technological innovation and industrial sustainable development. Concentrated laundry detergent has great advantages in terms of energy conservation, environmental protection, safety, mildness, high efficiency, etc., and is more competitive than traditional laundry products in all aspects. Washing powder contains a large amount of impurities, ineffective fillers and zeolites insoluble in water, and is gradually phased out by families. And laundry detergent is also becoming popular in the washing products industry in China.

[0003] During the process of washing clothes, due to the mechanical external force acting on water, detergent, and clothes to be washed, a certain degree of liquid foam is usually generated, that is, a dispersion system in which gas is dispersed in a liquid. For detergents, appropriate foam is necessary. Especially when washing clothes by hand, it can make consumers intuitively feel the presence of the detergent and give a soft touch; at the same time, the foam can adsorb and carry a certain amount of solid particle dirt. However, if the foam is too rich, other negative problems will be caused: such as overflowing the washing machine during machine washing, resulting in the loss and waste of detergent; forming a large resistance, reducing the effect of mechanical force on clothes, and affecting the washing effect; difficult to rinse, wasting water, electricity and manpower. Laundry detergent has now been generally accepted by domestic consumers, and most families have both hand washing and machine washing methods. In the past, the amount of detergent foam was usually one of the indicators to measure the washing efficiency. However, theoretically, there is no direct connection between washing efficiency and foam. In modern society, it is very common for families to use washing machines to wash items, and high-foam clothing detergents are generally not suitable for use in washing machines. Especially for fully enclosed automatic washing equipment, high foam will block the pipelines of the washing machine and increase the number and difficulty of rinsing clothes, which is not conducive to achieving the current social goals of environmental protection and energy conservation and emission reduction. Summary of the Invention

[0004] The purpose of the present invention is to provide a low-foam and easy-to-rinse laundry detergent and a preparation method thereof to solve the problems existing in the prior art.

[0005] To solve the above technical problems, the present invention provides the following technical solution: A preparation method of a low-foam and easy-to-rinse laundry detergent, comprising the following steps:

[0006] (1) Mix potassium hydrogenated coconut oil soap, sodium castor oil polyoxyethylene ether carboxylate, and sodium bisulfite, heat up to 70 - 100 °C, add ethylenediamine and phosphoric acid, heat up to 130 - 160 °C, stir at 60 - 100 rpm for 3 - 5 h to obtain a soap defoamer;

[0007] (2) Mix silicone paste and oleic acid, heat up to 130 - 180 °C, react for 4 - 6 h to obtain an organosilicon defoamer;

[0008] (3) Mix dodecylamine and p-toluenesulfonic acid, under a nitrogen atmosphere, heat up to 100 - 130 °C, stir at 30 - 80 rpm for 10 - 30 min, dropwise add ethylene oxide and propylene oxide at 5 - 15 mL / min, and keep warm for 30 - 60 min, then cool down to 70 - 90 °C to obtain a polyether defoamer;

[0009] (4) Mix the soap defoamer, organosilicon defoamer, and polyether defoamer, heat up to 30 - 60 °C, stir at 60 - 120 rpm for 2 - 5 h, and then add to deionized water at 100 - 500 mL / min to obtain a composite defoamer;

[0010] (5) Mix sodium alkylbenzene sulfonate, fatty alcohol polyoxyethylene ether, deionized water, acetic acid, and disodium ethylenediaminetetraacetate, heat up to 40 - 60 °C, stir at 300 - 600 rpm for 30 - 80 min, then add ethanol and the composite defoamer, continue stirring for 60 - 130 min, and cool to room temperature to obtain a low-foam and easy-rinse laundry detergent.

[0011] Further, the preparation method of the potassium hydrogenated coconut oil soap in step (1): Heat the 30 wt% potassium hydroxide aqueous solution to 70 - 90 °C, then add hydrogenated coconut oil acid, stir at 100 - 200 rpm until the hydrogenated coconut oil acid is completely dissolved, add sodium hypochlorite decolorant, and continue stirring for 10 - 30 min to obtain it.

[0012] Further, the mass ratio of the 30 wt% potassium hydroxide aqueous solution, hydrogenated coconut oil acid, and sodium hypochlorite decolorant is 100 - 200:30 - 50:2 - 6.

[0013] Further, the mass ratio of the potassium hydrogenated coconut oil soap, sodium castor oil polyoxyethylene ether carboxylate, sodium bisulfite, ethylenediamine, and phosphoric acid in step (1) is 10:1 - 10:0.01 - 0.08:1 - 5:0.05.

[0014] Further, the preparation method of the silicone paste in step (2): Place dimethyl silicone oil in an oil bath at 130 - 170 °C, stir at 20 rpm while adding fumed silica at 3 - 8 g / min, and then continue stirring for 3 - 6 h to obtain it.

[0015] Furthermore, the mass ratio of the dimethyl silicone oil to the fumed silica is 100:4 - 8.

[0016] Furthermore, the mass ratio of the silicone paste to the oleic acid in step (2) is 1 - 2:0.05 - 0.1.

[0017] Furthermore, the mass ratio of the dodecylamine, p-toluenesulfonic acid, ethylene oxide, and propylene oxide in step (3) is 0.5:0.1:100:80.

[0018] Furthermore, the mass ratio of the soap defoamer, silicone defoamer, polyether defoamer, and deionized water in step (4) is 20:10:5 - 10:10 - 20.

[0019] Furthermore, the mass ratio of the sodium alkylbenzene sulfonate, fatty alcohol polyoxyethylene ether, deionized water, acetic acid, disodium ethylenediaminetetraacetate, ethanol, and composite defoamer in step (5) is 20:20:40:1:0.2:2:0.1 - 0.3.

[0020] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: The present invention uses potassium hydrogenated coconut oil soap and sodium castor oil polyoxyethylene ether carboxylate as soap defoamers, and provides a weak acidic system through acetic acid for the washing environment, so that calcium and magnesium ions in hard water will not deposit, enhancing the binding of the soap defoamer with calcium and magnesium ions in water, and then generating calcium and magnesium soaps insoluble in water, thereby playing a role in defoaming and foam suppression, enabling the laundry detergent to achieve the effects of low foaming and easy rinsing. Then, it is compounded with a silicone defoamer and a polyether defoamer. The silicone defoamer quickly dissolves in hard water and high-temperature environments through its particles containing solid silica and polydimethylsiloxane particles to generate silicate, and the silica therein serves as the "pinpoint" for piercing the foam, enhancing the defoaming property. The polyether chain segment and the ethoxy group in the sodium castor oil polyoxyethylene ether carboxylate provide hydrophilic water solubility, enhancing the water solubility of the silicone defoamer and the soap defoamer in the laundry detergent, reducing the strength of the foam liquid film, making it thinner and weaker, thereby further improving the defoaming effect. Specific Embodiments

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0022] In order to more clearly illustrate the method provided by the present invention, it is described in detail through the following embodiments. The test methods for each index of the low-foaming and easy-rinsing laundry detergent prepared in the following embodiments are as follows:

[0023] Defoaming performance: At 25°C, prepare a mineralized water aqueous solution by mixing calcium chloride, magnesium chloride, sodium chloride, and water in a mass ratio of 10:10:30:1000. Then add a 5 g / L CT5-7C foaming agent mineralized aqueous solution that is 0.1 times the mass of water. Using the high-speed stirring method at a rotation speed of 11,000 rpm, add the same-sized examples and comparative examples to conduct initial defoaming rate and 3-minute defoaming rate tests.

[0024] Example 1; (1) Heat a 30 wt% potassium hydroxide aqueous solution to 70°C, then add hydrogenated coconut fatty acid, and stir at 100 rpm until the hydrogenated coconut fatty acid is completely dissolved. Add sodium hypochlorite decolorizer and continue stirring for 10 minutes to obtain potassium hydrogenated coconut oil soap; the mass ratio of the 30 wt% potassium hydroxide aqueous solution, hydrogenated coconut fatty acid, and sodium hypochlorite decolorizer is 100:30:2; mix potassium hydrogenated coconut oil soap, sodium castor oil polyoxyethylene ether carboxylate, and sodium bisulfite, heat to 70°C, add ethylenediamine and phosphoric acid, heat to 130°C, and stir at 60 rpm for 3 hours to obtain a soap defoaming agent; the mass ratio of potassium hydrogenated coconut oil soap, sodium castor oil polyoxyethylene ether carboxylate, sodium bisulfite, ethylenediamine, and phosphoric acid is 10∶1:0.01:1:0.05;

[0025] (2) Place dimethyl silicone oil in an oil bath at 130°C, stir at 20 rpm, and add fumed silica at a rate of 3 g / min. Then continue stirring for 3 hours to obtain silicone paste; the mass ratio of dimethyl silicone oil and fumed silica is 100:4; mix the silicone paste and oleic acid, heat to 130°C, and react for 4 hours to obtain an organosilicon defoaming agent; the mass ratio of the silicone paste and oleic acid is 1:0.05;

[0026] (3) Mix dodecylamine and p-toluenesulfonic acid, heat to 100°C under a nitrogen atmosphere, stir at 30 rpm for 10 minutes, dropwise add ethylene oxide and propylene oxide at a rate of 5 mL / min, and keep warm for 30 minutes. Then cool to 70°C to obtain a polyether defoaming agent; the mass ratio of dodecylamine, p-toluenesulfonic acid, ethylene oxide, and propylene oxide is 0.5:0.1:100:80;

[0027] (4) Mix the soap defoaming agent, organosilicon defoaming agent, and polyether defoaming agent, heat to 30°C, stir at 60 rpm for 2 hours, and then add to deionized water at a rate of 100 mL / min to obtain a composite defoaming agent; the mass ratio of the soap defoaming agent, organosilicon defoaming agent, polyether defoaming agent, and deionized water is 20:10:5:10;

[0028] (5) Mix sodium alkyl benzene sulfonate, fatty alcohol polyoxyethylene ether, deionized water, acetic acid, and disodium ethylenediaminetetraacetate, heat up to 40 °C, stir at 300 rpm for 30 min, then add ethanol and a composite defoamer, continue stirring for 60 min, and cool to room temperature to obtain a low-foam and easy-rinse laundry detergent; the mass ratio of sodium alkyl benzene sulfonate, fatty alcohol polyoxyethylene ether, deionized water, acetic acid, disodium ethylenediaminetetraacetate, ethanol, and the composite defoamer is 20:20:40:1:0.2:2:0.1.

[0029] Example 2; (1) Heat a 30 wt% aqueous potassium hydroxide solution to 80 °C, then add hydrogenated coconut fatty acid, stir at 150 rpm until the hydrogenated coconut fatty acid is completely dissolved, add sodium hypochlorite decolorizer, and continue stirring for 20 min to obtain potassium hydrogenated coconut oil soap; the mass ratio of the 30 wt% aqueous potassium hydroxide solution, hydrogenated coconut fatty acid, and sodium hypochlorite decolorizer is 150:40:4; mix potassium hydrogenated coconut oil soap, sodium castor oil polyoxyethylene ether carboxylate, and sodium bisulfite, heat up to 85 °C, add ethylenediamine and phosphoric acid, heat up to 140 °C, and stir at 80 rpm for 4 h to obtain a soap defoamer; the mass ratio of potassium hydrogenated coconut oil soap, sodium castor oil polyoxyethylene ether carboxylate, sodium bisulfite, ethylenediamine, and phosphoric acid is 10:6:0.05:3:0.05;

[0030] (2) Place dimethyl silicone oil in an oil bath at 150 °C, stir at 20 rpm while adding fumed silica at a rate of 5 g / min, and then continue stirring for 4 h to obtain silicone paste; the mass ratio of dimethyl silicone oil to fumed silica is 100:6; mix the silicone paste and oleic acid, heat up to 150 °C, and react for 5 h to obtain an organosilicon defoamer; the mass ratio of the silicone paste to oleic acid is 1.5:0.08;

[0031] (3) Mix dodecylamine and p-toluenesulfonic acid, heat up to 120 °C under a nitrogen atmosphere, stir at 60 rpm for 20 min, dropwise add ethylene oxide and propylene oxide at a rate of 10 mL / min, and keep warm for 40 min, then cool down to 80 °C to obtain a polyether defoamer; the mass ratio of dodecylamine, p-toluenesulfonic acid, ethylene oxide, and propylene oxide is 0.5:0.1:100:80;

[0032] (4) Mix the soap defoamer, organosilicon defoamer, and polyether defoamer, heat up to 45 °C, stir at 90 rpm for 3.5 h, and then add it to deionized water at a rate of 300 mL / min to obtain a composite defoamer; the mass ratio of the soap defoamer, organosilicon defoamer, polyether defoamer, and deionized water is 20:10:7:15;

[0033] (5) Mix sodium alkylbenzene sulfonate, fatty alcohol polyoxyethylene ether, deionized water, acetic acid, and disodium ethylenediaminetetraacetate, heat up to 50 °C, stir at 450 rpm for 50 min, then add ethanol and a composite defoamer, continue stirring for 100 min, and cool to room temperature to obtain a low-foam and easy-to-rinse laundry detergent; the mass ratio of sodium alkylbenzene sulfonate, fatty alcohol polyoxyethylene ether, deionized water, acetic acid, disodium ethylenediaminetetraacetate, ethanol, and the composite defoamer is 20:20:40:1:0.2:2:0.2.

[0034] Example 3; (1) Heat the 30 wt% potassium hydroxide aqueous solution to 90 °C, then add hydrogenated coconut fatty acid, stir at 200 rpm until the hydrogenated coconut fatty acid is completely dissolved, add sodium hypochlorite decolorizer, and continue stirring for 30 min to obtain potassium hydrogenated coconut oil soap; the mass ratio of the 30 wt% potassium hydroxide aqueous solution, hydrogenated coconut fatty acid, and sodium hypochlorite decolorizer is 200:50:6; mix potassium hydrogenated coconut oil soap, sodium castor oil polyoxyethylene ether carboxylate, and sodium bisulfite, heat up to 100 °C, add ethylenediamine and phosphoric acid, heat up to 160 °C, and stir at 100 rpm for 5 h to obtain a soap defoamer; the mass ratio of potassium hydrogenated coconut oil soap, sodium castor oil polyoxyethylene ether carboxylate, sodium bisulfite, ethylenediamine, and phosphoric acid is 10:10:0.08:5:0.05;

[0035] (2) Place dimethyl silicone oil in an oil bath at 170 °C, stir at 20 rpm while adding fumed silica at a rate of 8 g / min, and then continue stirring for 6 h to obtain silicone paste; the mass ratio of dimethyl silicone oil to fumed silica is 100:8; mix the silicone paste and oleic acid, heat up to 180 °C, and react for 6 h to obtain an organosilicon defoamer; the mass ratio of the silicone paste to oleic acid is 2:0.1;

[0036] (3) Mix dodecylamine and p-toluenesulfonic acid, heat up to 130 °C under a nitrogen atmosphere, stir at 80 rpm for 30 min, dropwise add ethylene oxide and propylene oxide at a rate of 15 mL / min, and keep warm for 60 min, then cool down to 90 °C to obtain a polyether defoamer; the mass ratio of dodecylamine, p-toluenesulfonic acid, ethylene oxide, and propylene oxide is 0.5:0.1:100:80;

[0037] (4) Mix the soap defoamer, organosilicon defoamer, and polyether defoamer, heat up to 60 °C, stir at 120 rpm for 5 h, and then add it to deionized water at a rate of 500 mL / min to obtain a composite defoamer; the mass ratio of the soap defoamer, organosilicon defoamer, polyether defoamer, and deionized water is 20:10:10:20;

[0038] (5) Mix sodium alkylbenzene sulfonate, fatty alcohol polyoxyethylene ether, deionized water, acetic acid, and disodium ethylenediaminetetraacetate, heat up to 60 °C, stir at 600 rpm for 80 min, then add ethanol and a composite defoamer, continue stirring for 130 min, and cool to room temperature to obtain a low-foaming and easy-to-rinse laundry detergent; the mass ratio of sodium alkylbenzene sulfonate, fatty alcohol polyoxyethylene ether, deionized water, acetic acid, disodium ethylenediaminetetraacetate, ethanol, and the composite defoamer is 20∶20∶40∶1∶0.2∶2∶0.3.

[0039] Comparative Example 1; The difference between Comparative Example 1 and Example 2 is that step (1) is absent, and step (4) is changed to: Mix silicone defoamer and polyether defoamer, heat up to 45 °C, stir at 90 rpm for 3.5 h, and then add it to deionized water at a rate of 300 mL / min to obtain a composite defoamer; the mass ratio of silicone defoamer, polyether defoamer, and deionized water is 10:7:15; the remaining steps are the same as those in Example 2.

[0040] Comparative Example 2; The difference between Comparative Example 2 and Example 2 is that step (2) is absent, and step (4) is changed to: Mix soap defoamer and polyether defoamer, heat up to 45 °C, stir at 90 rpm for 3.5 h, and then add it to deionized water at a rate of 300 mL / min to obtain a composite defoamer; the mass ratio of soap defoamer, polyether defoamer, and deionized water is 20:7:15; the remaining steps are the same as those in Example 2.

[0041] Comparative Example 3; The difference between Comparative Example 3 and Example 2 is that step (3) is absent, and step (4) is changed to: Mix soap defoamer and silicone defoamer, heat up to 45 °C, stir at 90 rpm for 3.5 h, and then add it to deionized water at a rate of 300 mL / min to obtain a composite defoamer; the mass ratio of soap defoamer, silicone defoamer, and deionized water is 20:10:15; the remaining steps are the same as those in Example 2.

[0042] Comparative Example 4; The difference between Comparative Example 4 and Example 2 is that step (5) is different. Step (5) is changed to: Mix sodium alkylbenzene sulfonate, fatty alcohol polyoxyethylene ether, deionized water, and disodium ethylenediaminetetraacetate, heat up to 50 °C, stir at 450 rpm for 50 min, then add ethanol and a composite defoamer, continue stirring for 100 min, and cool to room temperature to obtain a low-foaming and easy-to-rinse laundry detergent; the mass ratio of sodium alkylbenzene sulfonate, fatty alcohol polyoxyethylene ether, deionized water, disodium ethylenediaminetetraacetate, ethanol, and the composite defoamer is 20:20:40:0.2:2:0.2; the remaining steps are the same as those in Example 2.

[0043] Effect Example

[0044] The following Table 1 gives the performance analysis results of the low-foaming and easy-to-rinse laundry detergents of Examples 1 to 3 and Comparative Examples 1 to 4 of the present invention.

[0045] Table 1

[0046] Initial defoaming rate (%) Defoaming rate after 3 min (%) Example 1 99.1 100 Example 2 99.6 100 Example 3 99.3 100 Comparative Example 1 92.2 95.1 Comparative Example 2 94.7 97.3 Comparative Example 3 95.4 97.6 Comparative Example 4 96.5 97.2

[0047] From the comparison of the experimental data of the examples and comparative examples in Table 1, it can be found that the present invention uses potassium hydrogenated coconut oil soap and sodium castor oil polyoxyethylene ether carboxylate as soap defoamers, and provides a weakly acidic system through acetic acid for the washing environment, so that calcium and magnesium ions in hard water will not deposit, enhancing the binding property of the soap defoamer with calcium and magnesium ions in water, thereby playing a role in defoaming and foam inhibition, enabling the laundry detergent to achieve the effects of low foam and easy rinsing. Then, it is compounded with silicone defoamer and polyether defoamer. The silicone defoamer quickly dissolves in hard water and high-temperature environments through its particles containing solid silica and polydimethylsiloxane particles to generate silicate, and the silica therein serves as the "needle tip" for piercing the foam, enhancing the defoaming property. The polyether chain segment and the ethoxy group in sodium castor oil polyoxyethylene ether carboxylate provide hydrophilic water solubility, enhancing the water solubility of the silicone defoamer and the soap defoamer in the laundry detergent, reducing the strength of the foam liquid film, making it thinner and weaker, thereby further improving the defoaming effect.

[0048] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claimed rights.

Claims

1. A method for preparing a low-foaming, easy-to-rinse laundry detergent, characterized in that: The following steps are involved: (1) Mix hydrogenated potassium coconut soap, sodium castor oil polyoxyethylene ether carboxylate, and sodium bisulfite, heat to 70-100°C, add ethylenediamine and phosphoric acid, heat to 130-160°C, and stir at 60-100 rpm for 3-5 hours to obtain a soap defoamer; (2) Mix the silicone paste and oleic acid, raise the temperature to 130-180°C, and react for 4-6 hours to obtain an organosilicon defoamer; (3) Dodecylamine and p-toluenesulfonic acid are mixed, heated to 100-130°C under a nitrogen atmosphere, stirred at 30-80 rpm for 10-30 min, ethylene oxide and propylene oxide are added dropwise at 5-15 mL / min, and the mixture is kept warm for 30-60 min, and then cooled to 70-90°C to obtain a polyether defoamer; (4) Mix the soap defoamer, silicone defoamer and polyether defoamer, raise the temperature to 30-60°C, stir at 60-120 rpm for 2-5 hours, and then add deionized water at 100-500 mL / min to obtain a composite defoamer; (5) Mix sodium alkylbenzene sulfonate, fatty alcohol polyoxyethylene ether, deionized water, acetic acid, and disodium ethylenediaminetetraacetate, heat to 40-60°C, and stir at 300-600 rpm for 30-80 min. Then add ethanol and a composite defoamer, continue stirring for 60-130 min, and cool to room temperature to obtain a low-foaming, easy-to-rinse laundry detergent.

2. The method for preparing a low-foam, easy-to-rinse laundry detergent according to claim 1, characterized in that: The preparation method of the hydrogenated potassium cocoate soap in step (1) is as follows: a 30 wt % potassium hydroxide aqueous solution is heated to 70-90° C., and then hydrogenated coconut acid is added, and stirred at 100-200 rpm until the hydrogenated coconut acid is completely dissolved, and sodium hypochlorite decolorizing agent is added, and stirring is continued for 10-30 min to obtain the soap.

3. The method for preparing a low-foam, easy-to-rinse laundry detergent according to claim 2, characterized in that: The mass ratio of the 30wt% potassium hydroxide aqueous solution, hydrogenated coconut oil acid and sodium hypochlorite decolorizing agent is 100-200:30-50:2-6.

4. The method for preparing a low-foam, easy-to-rinse laundry detergent according to claim 1, characterized in that: The mass ratio of the hydrogenated potassium coconut soap, castor oil polyoxyethylene ether carboxylate sodium, sodium bisulfite, ethylenediamine and phosphoric acid in step (1) is 10:1~10:0.01~0.08:1~5:0.

05.

5. The method for preparing a low-foam, easy-to-rinse laundry detergent according to claim 1, characterized in that: The preparation method of the silicone paste in step (2) is as follows: place dimethyl silicone oil in an oil bath at 130-170° C., add fumed silica at a rate of 3-8 g / min while stirring at 20 rpm, and then continue stirring for 3-6 hours to obtain the silicone paste.

6. The method for preparing a low-foam, easy-to-rinse laundry detergent according to claim 5, characterized in that: The mass ratio of the dimethyl silicone oil to the fumed silica is 100:4-8.

7. The method for preparing a low-foam, easy-to-rinse laundry detergent according to claim 1, characterized in that: The mass ratio of the silicone paste to oleic acid in step (2) is 1-2:0.05-0.

1.

8. The method for preparing a low-foaming, easy-to-rinse laundry detergent according to claim 1, characterized in that: In step (3), the mass ratio of dodecylamine, p-toluenesulfonic acid, ethylene oxide and propylene oxide is 0.5:0.1:100:

80.

9. The method for preparing a low-foaming, easy-to-rinse laundry detergent according to claim 1, characterized in that: The mass ratio of the soap defoamer, silicone defoamer, polyether defoamer and deionized water in step (4) is 20:10:5~10:10~20.

10. The method for preparing a low-foaming, easy-to-rinse laundry detergent according to claim 1, characterized in that: The mass ratio of the sodium alkylbenzene sulfonate, fatty alcohol polyoxyethylene ether, deionized water, acetic acid, disodium ethylenediaminetetraacetate, ethanol, and composite defoaming agent in step (5) is 20:20:40:1:0.2:2:0.1-0.3.