CN113018204A

CN113018204A - Self-thickening composition of amino acid surfactants

Info

Publication number: CN113018204A
Application number: CN201911347827.9A
Authority: CN
Inventors: 王鞠骏; 洪菁; 乔小玲
Original assignee: Shanghai Jahwa United Co Ltd
Current assignee: Shanghai Jahwa United Co Ltd
Priority date: 2019-12-24
Filing date: 2019-12-24
Publication date: 2021-06-25

Abstract

The present invention discloses a thickener composition comprising an amino acid surfactant, comprising: sodium lauroyl sarcosinate; a zwitterionic surfactant; and a personal care art acceptable carrier, wherein the zwitterionic surfactant is a combination of sodium lauroyl amphoacetate and lauramidopropyl betaine, wherein the total concentration of the sodium lauroyl sarcosinate and the zwitterionic surfactant is from 5 to 25% by weight, wherein the weight ratio of the sodium lauroyl sarcosinate to the zwitterionic surfactant is from 1:2 to 1:4, wherein the pH of the composition is from 4.9 to 5.2. The use of the thickener composition in personal care products is also disclosed.

Description

Self-thickening composition of amino acid surfactants

Technical Field

The invention relates to the fields of colloid and surface chemistry, in particular to a self-thickening composition of a mild amino acid surfactant, a preparation method of the self-thickening composition and application of the self-thickening composition in cosmetics.

Background

The amino acid surfactant is a surfactant based on biological substances, has the characteristics of excellent surface activity, low irritation, easy degradation, good antibacterial property and the like, and meets the expectations of people for green, safety and no pollution of personal cleaning products. It is a general term for compounds having amino and carboxyl groups, and constitutes different amino acid surfactants depending on the difference between the amino and carboxyl groups. Common amino acid surfactants comprise five amino acid surfactants of glutamic acid, glycine, sarcosine, alanine and methyl taurine.

In practical applications, amino acid surfactants are characterized by being difficult to thicken, and the reason for this is that the hydrophilic group is relatively large due to the molecular structure of the amino acid surfactant, and the amino acid surfactant is difficult to grow into rod-like micelles after forming spherical micelles.

Generally, the skilled person will raise the viscosity of the system by adding a thickener. At present, various manufacturers usually add a thickener of a high molecular polymer. This, in turn, causes the following problems: 1) jelly-like at low temperature; 2) the color change phenomenon is easy to occur at high temperature; 3) foaming of the amino acid type surfactant is suppressed; 4) particularly, the skin feel is influenced by the polymer raw materials during cleaning, and the specific manifestations are stickiness, unclean cleaning and strong residual feel; 5) the price of the high polymer raw material is not so high that the formula cost space is occupied. Therefore, the additional addition of the thickener causes negative effects such as inefficiency, increased cost, low temperature pectin, poor skin feel, and the like.

The prior technical schemes disclose that the thickening is achieved through self-thickening of an amino acid surfactant, however, the technical schemes do not provide a thickening scheme of acyl sarcosinate, the active content of a compound system is high and reaches above 15%, and the effect on the safety of the formula, particularly the eye irritation is existed. For example, US201680073632.8 discloses self-thickening compositions of one or more N-acyl acidic amino acids and/or one salt thereof and one or more zwitterionic surfactants comprising a plurality of acyl glutamates and a plurality of zwitterionic surfactants as thickeners.

Another technical solution is for example CN20131012777769.5 disclosing an amino acid type surfactant self-thickening composition comprising cocamidopropyl hydroxysultaine and sodium lauroyl sarcosinate as thickening agents. However, the low-temperature precipitation stability risk exists, the low-temperature precipitation stability risk needs to be compounded with other surfactants and solvents for use, or the total active content is increased to improve the low-temperature stability, but the thickening cost is increased, and from the safety perspective, the lower the addition amount of the surfactant is on the premise of ensuring the cleaning power of the product, the safer the product is, and the expectation of the current consumers for personal cleaning products is met. Meanwhile, the low addition amount means lower formula cost and improves thickening efficiency.

Therefore, the problem that the amino acid type surfactant (especially sodium lauroyl sarcosinate) is difficult to thicken in application is not ignored, and the research and development of an amino acid type surfactant system capable of self-thickening has important practical significance.

Disclosure of Invention

In one aspect, the present invention relates to an amino acid surfactant-containing thickener composition comprising:

sodium lauroyl sarcosinate;

a zwitterionic surfactant; and

a carrier that is acceptable in the personal care art,

wherein the zwitterionic surfactant is a combination of sodium lauroamphoacetate and lauramidopropyl betaine,

wherein the total concentration of the sodium lauroyl sarcosinate and the zwitterionic surfactant is 5-25% by weight,

wherein the weight ratio of the sodium lauroyl sarcosinate to the zwitterionic surfactant is 1:2 to 1:4,

wherein the pH of the composition is 4.9-5.2.

In a preferred embodiment, the weight ratio of sodium lauroyl sarcosinate to sodium lauroyl amphoacetate to lauramidopropyl betaine in the thickener composition of the invention is about 1:1:1 to 1:3: 1. In a more preferred embodiment, the weight ratio of sodium lauroyl sarcosinate to sodium lauroyl amphoacetate to lauramidopropyl betaine in the thickener composition of the invention is about 1:2: 1.

In a preferred embodiment, the thickener composition of the invention has a pH of 5.1.

In a preferred embodiment, the total concentration of said sodium lauroyl sarcosinate and said zwitterionic surfactant in the thickener composition according to the invention is between 5 and 15 wt.%. In a more preferred embodiment, the total concentration of sodium lauroyl sarcosinate and zwitterionic surfactant in the thickener composition according to the invention is 8% by weight.

In a preferred embodiment, the carrier in the thickener composition of the invention is an aqueous carrier.

In another aspect, the invention also relates to the use of the thickener composition in a personal care product.

In a preferred embodiment, the personal care product is selected from the group consisting of: infant body wash, infant shampoo, infant body wash, child hand wash, adult body wash, adult shampoo, adult hand wash, and adult facial cleanser.

In a preferred embodiment, the thickener composition is present in the personal care product in an amount equal to or greater than 20% by weight.

Detailed Description

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. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are described herein. For the purposes of the present invention, the following terms are defined below.

The term "about" as used herein refers to an amount, level, value, dimension, size, or amount that differs by up to 30%, 20%, or 10% as compared to the amount, level, value, dimension, size, or amount of a reference. The percentages used herein are by weight unless otherwise indicated.

Throughout the specification and claims, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

Applicants have unexpectedly found that mixing certain amino acid surfactants (e.g., sodium lauroyl sarcosinate) with certain zwitterionic surfactants (e.g., sodium lauroamphoacetate and/or lauramidopropyl betaine) can produce compositions that form self-thickening. Thus, the present invention for the first time compounds sodium lauroyl sarcosinate with zwitterionic surfactants (e.g., sodium lauroamphoacetate and/or lauramidopropyl betaine) to form self-thickening compositions, providing highly effective thickening. The self-thickening composition can be incorporated into personal care products, yet retains a high thickening effect.

In a preferred embodiment, the thickener composition of the present invention consists essentially of sodium lauroyl sarcosinate, a zwitterionic surfactant (e.g., sodium lauroamphoacetate and/or lauramidopropyl betaine), and a personal care acceptable carrier. In a preferred embodiment, the personal care art acceptable carrier is an aqueous carrier. For example, the carrier is water, e.g., pure water, distilled water, deionized water, and the like.

As used herein, the term "consisting essentially of … …" means that the composition contains less than about 1%, preferably less than about 0.5%, of ingredients other than those listed. The term "consisting essentially of … …" means that the indicated material is present in an amount of about 99.5% to about 100% by weight, preferably about 99.9% to about 100% by weight, and more preferably 99.99% to about 100% by weight, and most preferably all other materials are present only as impurities below an analytically detectable level.

Amino acid surfactants

The amino acid surfactant is a mild and degradable anionic surfactant, and the main active ingredient of the surfactant is a compound amino acid sodium salt. At present, amino acid surfactants have been widely used: medical supplies such as gynecological lotions, wound cleansers, analgesics; daily chemical products such as shampoo, infant washing product, body wash, face wash, and hand cleanser; oral care products such as toothpaste, dentifrice, mouthwash and the like.

The performance of the amino acid surfactant in daily chemical washing articles is mainly represented by the following characteristics: (1) the foam is rich and stable, the property is mild, and the overall irritation of the formula can be reduced; (2) can quickly promote flocculation in shampoo formula, and make conditioner, silicone oil, nutrient components, etc. quickly adsorbed on hair. The use efficiency of the conditioner, the silicone oil, the nutritional ingredients and the like is improved, and the use amount of the conditioner, the silicone oil, the nutritional ingredients and the like in the formula is reduced; (3) has excellent sterilization and bacteriostasis performance and excellent effects of removing dandruff and relieving itching; (4) has the property of repairing chemically damaged and naturally damaged hair; (5) endows the product with good appearance and rheological property; (6) easy degradation and no pollution to the environment; (7) pH 7-9, mild and non-irritating.

Sodium lauroyl sarcosinate is a common amino acid surfactant. In practical application, sodium lauroyl sarcosinate has the characteristic of difficult thickening. For example, at an active content of 8 wt% and a pH of 5.2 to 6.5, the viscosity of sodium lauroyl sarcosinate is very low, being only 8 mpa.s. At the use concentrations of the present invention, sodium lauroyl sarcosinate alone had substantially no thickening effect. In the application of personal care products, the amino acid type surfactant has the problem of difficult or even impossible thickening.

In certain embodiments, the claimed compositions comprise less than about 10 wt% amino acid surfactant, less than 8 wt%, or less than 6 wt%, or less than 5 wt%, or less than 4 wt%, or less than 3 wt%, or less than 2.5 wt% amino acid surfactant. In certain embodiments, the compositions of the present invention comprise 2% by weight of the amino acid surfactant.

Zwitterionic surfactants

Zwitterionic surfactants refer to surfactants that have both ionic properties.

In certain embodiments of the present invention, a combination of sodium lauroamphoacetate and lauramidopropyl betaine is employed as the zwitterionic surfactant.

The sodium lauroamphoacetate has good compatibility with various surfactants and can be compatible with soap base. In addition, the sodium lauroamphoacetate has low irritation and is particularly mild to skin and eyes, and the irritation can be obviously reduced by matching with an anionic surfactant. The sodium lauroamphoacetate has good foaming power, rich and fine foam and good skin feel, and can obviously improve the foam state of a formula system. Has conditioning effect in shampoo, and can replace betaine. In addition, sodium lauroamphoacetate has good salt resistance and is stable in a wide pH value range. Meanwhile, the sodium lauroamphoacetate is easy to biodegrade and has good safety. However, at the use concentrations of the present invention, sodium lauroamphoacetate alone has substantially no thickening effect. For example, at an active content of 8 wt%, pH 5.2-6.5, the viscosity of sodium lauroamphoacetate is very low, only 25 mpa.s.

Lauramidopropyl betaine is a commonly used betaine zwitterionic surfactant. It has excellent solubility and compatibility; has excellent foamability and obvious thickening property; the detergent has low irritation and sterilization, and the compatibility of the detergent and the detergent can obviously improve the softness, conditioning and low-temperature stability of the detergent; and has good hard water resistance, antistatic property and biodegradability. However, at the use concentrations of the present invention, lauramidopropyl betaine alone had substantially no thickening effect.

In certain embodiments, the claimed compositions comprise from about 1% to about 10% by weight of the zwitterionic surfactant. In a preferred embodiment, the composition of the invention comprises 2 to 8 wt% of a zwitterionic surfactant. In a more preferred embodiment, the composition of the invention comprises 4 to 6% by weight of zwitterionic surfactant. In a particular embodiment, the composition of the invention comprises 6% by weight of zwitterionic surfactant.

In certain embodiments, the weight ratio of sodium lauroamphoacetate to lauramidopropyl betaine in the self-thickener compositions of the invention is from about 1:1 to about 3: 1. In some preferred embodiments, the weight ratio of sodium lauroamphoacetate to lauramidopropyl betaine in the self-thickener compositions of the invention is from about 2:1 to about 3: 1.

Self-thickening composition

The present invention is based on the following unexpected findings: compositions of sodium lauroyl sarcosinate with certain zwitterionic surfactants (e.g., sodium lauroamphoacetate and/or lauramidopropyl betaine) provide synergistic viscosity enhancement with superior self-thickening capabilities.

In certain embodiments, the surfactant in the compositions of the present invention consists essentially of an amino acid surfactant and a zwitterionic surfactant. In a preferred embodiment, the compositions of the present invention are substantially free of other types of surfactants.

In a preferred embodiment, the compositions of the present invention have a self-thickening effect and can be added to personal cleansing products as thickeners with superior thickening effects. In a preferred embodiment, the composition of the present invention is substantially free of additional thickening agents.

The terms "substantially free", "substantially free" or "substantially free" mean that the indicated material is present in an amount of from 0 wt% to 0.5 wt%, or preferably from 0 wt% to 0.1 wt%, or more preferably from 0 wt% to 0.01 wt%, and most preferably it is not present in an analytically detectable amount.

In certain embodiments, the total concentration of surfactants in the compositions of the present invention is from 5 to 25 weight percent. In a preferred embodiment, the total concentration of surfactants in the composition of the invention is from 5 to 15% by weight. In a preferred embodiment, the total concentration of surfactants in the composition of the invention is from 5 to 10% by weight. In a preferred embodiment, the total concentration of surfactants in the composition of the invention is 8% by weight.

In certain embodiments, the weight ratio of sodium lauroyl sarcosinate to zwitterionic surfactant in the self-thickener compositions of the invention is about 1:2 to about 1: 4. In some preferred embodiments, the weight ratio of sodium lauroyl sarcosinate to zwitterionic surfactant in the self-thickener composition of the invention is about 1:3 to about 1: 4.

In certain embodiments, the weight ratio of sodium lauroyl sarcosinate to sodium lauroyl amphoacetate to lauramidopropyl betaine in the self-thickener compositions of the invention is about 1:1:1 to about 1:3: 1. In some preferred embodiments, the weight ratio of sodium lauroyl sarcosinate to sodium lauroyl amphoacetate to lauramidopropyl betaine in the self-thickener composition of the invention is from about 1:2:1 to about 1:3: 1.

The pH of the self-thickening composition of the present invention may be adjusted with any organic or inorganic acid. For example, acids that may be used include, but are not limited to: inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid and phosphoric acid, carboxylic acids such as acetic acid, fumaric acid, maleic acid, oxalic acid, malonic acid, succinic acid, citric acid and malic acid, sulfonic acids such as methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid and toluenesulfonic acid, and amino acids such as glutamic acid and aspartic acid.

The pH of the self-thickening agent composition of the present invention is 4.9 to 5.2. In some preferred embodiments, the pH of the self-thickening composition of the present invention is from 4.9 to 5.1. In some preferred embodiments, the pH of the self-thickening composition of the present invention is at least 5.1.

The invention is further illustrated below with reference to specific examples. It is to be understood, however, that these examples are illustrative only and are not to be construed as limiting the scope of the present invention. Test methods in which specific conditions are not specified in the following examples are generally carried out under conventional conditions or under conditions recommended by the manufacturer. All percentages and parts are by weight unless otherwise indicated.

1. Experimental Material

Sodium lauroyl sarcosinate (30% active ingredient content), purchased from Shanghai Lisheng Chemicals, Inc. (under the trade name AC-215); sodium lauroamphoacetate (active ingredient content 30%) purchased from solvay corporation under the trade name MIRANOL ULTRA L-32; lauramidopropyl betaine (active ingredient content 30%) was purchased from Guangzhou Tiancigao New materials, Inc. (trade name TC-LAB 35).

2. Laboratory apparatus

A viscosity meter: brookfield RVDVS

3. Experimental process

3.1 weighing selected amount of each component of the surfactant complex

3.2 weighing deionized water, adding the mixture of the components weighed in the first step into the deionized water under the condition of stirring, heating to 60 ℃, and keeping stirring until the mixture is uniform

3.3 reducing the temperature to 25 ℃, adding citric acid to adjust the pH

3.4 the prepared sample is put into a thermostat at 25 ℃ for 24 hours and then taken out, a proper rotor and a proper rotating speed are selected, the sample viscosity is tested by a Brookfield viscometer, data are recorded after the reading is stable, and the viscosity is tested at 25 ℃.

Example 1: preparation of self-thickening compositions

6.66g of sodium lauroamphoacetate and 20g of sodium lauroyl sarcosinate were weighed, 73.33g of deionized water was added, stirring was started at 400 rpm, the mixture was held for 6 minutes, and the mixture was heated to 60 ℃ until uniform.

Cooling to 25 deg.C, adding citric acid to adjust pH to 5.0 for use.

Example 2: preparation of self-thickening compositions

2.67g of sodium lauroamphoacetate and 17.77g of sodium lauroyl sarcosinate were weighed, 73.33g of deionized water was added, stirring was started at 400 rpm, the mixture was kept for 6 minutes, and the mixture was heated to 60 ℃ with stirring until homogeneous.

Cooling to 25 deg.C, adding citric acid to adjust pH to 5.0 for use.

Example 3: preparation of self-thickening compositions

13.33g of sodium lauroamphoacetate and 13.33g of sodium lauroyl sarcosinate were weighed, 73.33g of deionized water was added, stirring was started at 400 rpm, the mixture was kept for 6 minutes, and the mixture was heated to 60 ℃ with stirring until homogeneous.

Cooling to 25 deg.C, adding citric acid to adjust pH to 5.0 for use.

Example 4: preparation of self-thickening compositions

17.77g of sodium lauroamphoacetate and 8.9g of sodium lauroyl sarcosinate were weighed out, 73.33g of deionized water was added, stirring was started at 400 rpm, the mixture was kept for 6 minutes, and the mixture was heated to 60 ℃ with stirring until homogeneous.

Cooling to 25 deg.C, adding citric acid to adjust pH to 5.0 for use.

Example 5: preparation of self-thickening compositions

20g of sodium lauroamphoacetate and 6.67g of sodium lauroyl sarcosinate were weighed, 73.33g of deionized water was added, stirring was started at a speed of 400 rpm for 6 minutes, and heating was carried out to 60 ℃ with stirring until homogeneous.

Cooling to 25 deg.C, adding citric acid to adjust pH to 5.0 for use.

Test example 1: viscosity determination of self-thickening compositions

The samples of examples 1-5 were placed in an incubator at 25 ℃ for 24 hours and then removed, and the sample viscosity was measured using a Brookfield viscometer using a # 3 rotor at 12rpm, and the data was recorded after the readings stabilized, and the viscosity was measured at 25 ℃.

Sodium lauroyl sarcosinate is an amino acid surfactant which is compatible with skin and has excellent biodegradability, but has the problem of difficult thickening in the aspect of use, increases the application difficulty, and has very low viscosity of only 8mPa.s under the conditions that the content of active substances is 8 percent and the pH value is 5.2-6.5.

Sodium lauroamphoacetate is a commonly used mild zwitterionic surfactant, and its viscosity is still very low, only 25mpa.s, at an active content of 8%, ph 4.5-6.5.

The test example observed the effects of the two surfactants when used in combination, and the results are shown in table 1.

Table 1: when the pH value is 5.0 and the content of the surface active total active matter is 8 percent, the viscosity result of the lauroyl sarcosine sodium/sodium lauroyl amphoacetate compound composition under the conditions of different content ratios of the active matters

As shown in Table 1, when the content ratio of the lauroyl sarcosine sodium to the lauroyl amphoacetate active substance is in the range of 3:1 to 1:3, the two compound systems have no synergistic tackifying effect. And under the trial ratio, the system is all in a fog-like opaque appearance. Therefore, the single sodium lauroyl sarcosinate and the sodium lauroyl amphoacetate are compounded, the self-thickening effect is avoided, and the stability risk of low-temperature precipitation exists.

Example 6: preparation of self-thickening compositions

5.33g of sodium lauroamphoacetate, 16g of sodium lauroyl sarcosinate and 5.33g of lauramidopropyl betaine are weighed, 73.33g of deionized water is added, stirring is started at a speed of 400 rpm, the mixture is kept for 6 minutes, the mixture is heated to 60 ℃, and the stirring is kept until the mixture is uniform.

Cooling to 25 deg.C, adding citric acid to adjust pH to 5.0 for use.

Example 7: preparation of self-thickening compositions

6.67g of sodium lauroamphoacetate, 13.33g of sodium lauroyl sarcosinate and 6.67g of lauramidopropyl betaine are weighed, 73.33g of deionized water are added, stirring is started at a speed of 400 rpm, the mixture is kept for 6 minutes, the mixture is heated to 60 ℃, and the stirring is kept until uniform.

Cooling to 25 deg.C, adding citric acid to adjust pH to 5.0 for use.

Example 8: preparation of self-thickening compositions

8.9g of sodium lauroamphoacetate, 8.9g of sodium lauroyl sarcosinate and 8.9g of lauramidopropyl betaine are weighed, 73.33g of deionized water is added, stirring is started at a speed of 400 rpm, the mixture is kept for 6 minutes, the mixture is heated to 60 ℃, and the stirring is kept until the mixture is uniform.

Cooling to 25 deg.C, adding citric acid to adjust pH to 5.0 for use.

Example 9: preparation of self-thickening compositions

13.33g of sodium lauroamphoacetate, 6.67g of sodium lauroyl sarcosinate and 6.67g of lauramidopropyl betaine are weighed, 73.33g of deionized water are added, stirring is started at a speed of 400 rpm, the mixture is kept for 6 minutes, the mixture is heated to 60 ℃, and the stirring is kept until uniform.

Cooling to 25 deg.C, adding citric acid to adjust pH to 5.0 for use.

Example 10: preparation of self-thickening compositions

16g of sodium lauroamphoacetate, 5.33g of sodium lauroyl sarcosinate and 5.33g of lauramidopropyl betaine are weighed, 73.33g of deionized water is added, stirring is started at a speed of 400 rpm, the mixture is kept for 6 minutes, the mixture is heated to 60 ℃, and the stirring is kept until the mixture is uniform.

Cooling to 25 deg.C, adding citric acid to adjust pH to 5.0 for use.

Test example 2: viscosity determination of self-thickening compositions

The samples from examples 6-10 were placed in an incubator at 25 ℃ for 24 hours and then removed, and the sample viscosity was measured using a Brookfield viscometer using a # 3 rotor at 12rpm, and the data was recorded after the readings stabilized, and the viscosity was measured at 25 ℃.

Lauramidopropyl betaine is a common betaine zwitterionic surfactant, and is compounded in the composition systems of examples 1-5 to change the performance of the original system. The test example observed the effects of the three surfactants when used in combination, and the results are shown in table 2.

Table 2: when the pH value is 5.0 and the content of the total surface active substances is 8 percent, the viscosity result of the lauroyl sarcosine sodium/sodium lauroyl amphoacetate/lauramidopropyl betaine compound composition under the condition of different active substance content ratios

As shown in Table 2, when the content ratio of the lauroyl sarcosine sodium to the lauroyl amphoacetate to the lauramidopropyl betaine is in the range of 1:1:1 to 1:3:1, the compound system of the lauroyl sarcosine sodium and the lauroyl amphoacetate can achieve the synergistic tackifying effect. Wherein the viscosity of the system is relatively highest at the content ratio of 1:2:1, and the viscosity is improved by about 90 times. In the tested mixture ratio, the system is clear and transparent, and the stability at low temperature is examined by placing the samples 6-10 at 4 ℃, and no precipitation phenomenon still exists after 30 days. Therefore, the lauroyl amidopropyl betaine is compounded and put into a system of sodium lauroyl sarcosinate and sodium lauroyl amphoacetate, so that the stability of the system can be effectively improved, and the system can be thickened.

Examples 11 to 15: preparation of self-thickening compositions

93.31g of sodium lauroamphoacetate, 46.69g of sodium lauroyl sarcosinate and 46.69g of lauramidopropyl betaine are weighed, 513.31g of deionized water are added, stirring is started, the speed is 400 rpm, the stirring is kept for 6 minutes, the mixture is heated to 60 ℃, and the stirring is kept until the mixture is uniform.

Cooling to 25 deg.C, adding citric acid to adjust pH from 4.8 to 5.2 respectively for use.

Table 3 shows the compositions and amounts of the self-thickening compositions of examples 11-15.

TABLE 3

Test example 3: effect of pH on viscosity of self-thickening compositions

The samples prepared in examples 11-15 were placed in an incubator at 25 ℃ for 24 hours and then removed, and the viscosity of the samples was measured using a Brookfield viscometer using a # 3 rotor at 12rpm, and the viscosity was measured at 25 ℃ after the readings were stabilized by recording the data. The results are shown in Table 3.

Table 4: in the content ratio of the surface active substances to sodium lauroyl sarcosinate: sodium lauroamphoacetate: viscosity results for self-thickening systems at different pH under conditions of lauramidopropyl betaine ═ 1:2:1 and total active content of 8%

From the results, it is understood that when the active substance content ratio of lauroyl sarcosine sodium, sodium lauroamphoacetate and lauramidopropyl betaine is compounded at 1:2:1, a self-thickening effect is exhibited in the pH range of 4.9 to 5.1. Particularly, when the pH is 5.1, the viscosity of the composition reaches the highest value, namely 3375mPa.s, and the viscosity is improved by about 420 times. The viscosity meets the requirements of common mild infant products, can be directly applied to the formula, and can also be applied to adult cleaning and nursing products as a compound viscosity-increasing composition.

Example 16: preparation of self-thickening compositions

8.33g of sodium lauroamphoacetate, 4.17g of sodium lauroyl sarcosinate and 4.17g of lauramidopropyl betaine are weighed, 83.33g of deionized water are added, stirring is started at a speed of 400 rpm, the mixture is kept for 6 minutes, the mixture is heated to 60 ℃, and the stirring is kept until the mixture is uniform.

Cooling to 25 deg.C, adding citric acid to adjust pH to 5.1 for use.

Example 17: preparation of self-thickening compositions

41.67g of sodium lauroamphoacetate, 20.83g of sodium lauroyl sarcosinate and 20.83g of lauramidopropyl betaine are weighed, 16.67g of deionized water are added, stirring is started at a speed of 400 rpm, the mixture is kept for 6 minutes, the mixture is heated to 60 ℃, and the stirring is kept until the mixture is uniform.

Cooling to 25 deg.C, adding citric acid to adjust pH to 5.1 for use.

Test example 4: viscosity determination of self-thickening compositions

The samples prepared in examples 16 to 17 were placed in an incubator at 25 ℃ for 24 hours and then removed, and the viscosity of the samples was measured using a Brookfield viscometer with a # 3 rotor at 12rpm, and the data was recorded after the readings were stabilized, and the viscosity was measured at 25 ℃. The results are shown in Table 5.

Table 5: in the content ratio of the surface active substances to sodium lauroyl sarcosinate: sodium lauroamphoacetate: the viscosity results for the self-thickening compositions at different actives levels under conditions of lauramidopropyl betaine ═ 1:2:1 and a formulation pH of 5.1 were compared to example 14.

From the results, it can be seen that at ph5.1, raising the total active concentration of the system to 25% only slightly raises the viscosity of the complex, and that a high active concentration of the formulated system is too inefficient at thickening for self-thickening compositions. This is of course likely to be associated with the thickening profile of the formulation at different active concentrations, with the active content altering the thickening profile, and the cost advantage of the low irritation and efficient thickening efficiency of the low surface active content formulation composition is evident from a practical point of view. From this, it can be seen that example 14 exhibited good self-thickening efficiency.

Application example

The compositions of examples 8-15 of the present invention can be used as intermediate materials for the preparation of corresponding personal cleansing products, preferably rinse-off cleansing product compositions, including but not limited to the preparation of products in the form of baby bath, shampoo bath, children's hand cleanser, adult bath, shampoo, hand cleanser, face wash, and the like. The following are specific examples of the use of the compositions obtained by the examples in personal cleansing care products, as well as the formulations and methods of preparation of these dosage forms. The specific application examples are as follows:

application example 1: preparation of baby bath lotion

The process comprises the following steps: heating phase B to 70-75 deg.C, stirring to dissolve completely and transparent; adding phase A, stirring until the solution is fully dissolved and transparent; cooling to 45-50 deg.C, adding phase C, stirring, and mixing; adding a proper amount of citric acid to adjust the pH value to a target range, and uniformly stirring to discharge.

Application example 2: preparation of infant shampoo

Application example 3: preparation of baby shampoo and shower gel

Application example 4: preparation of children hand sanitizer

Application example 5: preparation of shower gel

The process comprises the following steps: heating phase A to 70-75 deg.C, stirring to dissolve completely and transparent; adding phase B, stirring until the solution is fully dissolved and transparent; cooling to 45-50 deg.C, adding phase C, stirring, and mixing; adding appropriate amount of citric acid and sodium chloride to adjust pH value and viscosity to target range, stirring well and discharging.

Application example 6: preparation of face cleanser

Claims

1. An amino acid surfactant-containing thickener composition comprising:

sodium lauroyl sarcosinate;

a zwitterionic surfactant; and

a carrier that is acceptable in the personal care art,

wherein the pH of the composition is 4.9-5.2.

2. The composition of claim 1, wherein the weight ratio of sodium lauroyl sarcosinate to sodium lauroyl amphoacetate to lauramidopropyl betaine is from about 1:1:1 to about 1:3: 1.

3. The composition of claim 2, wherein the weight ratio of sodium lauroyl sarcosinate to sodium lauroyl amphoacetate to lauramidopropyl betaine is about 1:2: 1.

4. The composition of claim 1, wherein the composition has a pH of 5.1.

5. The composition of claim 1, wherein said sodium lauroyl sarcosinate and said zwitterionic surfactant are present in a total concentration of 5 to 15% by weight.

6. The composition of claim 5, wherein said sodium lauroyl sarcosinate and said zwitterionic surfactant are present in a total concentration of 8% by weight.

7. The composition of claim 1, wherein the carrier is an aqueous carrier.

8. Use of the composition of claim 1 in a personal care product.

9. The use according to claim 8, wherein the personal care product is selected from the group consisting of: infant body wash, infant shampoo, infant body wash, child hand wash, adult body wash, adult shampoo, adult hand wash, and adult facial cleanser.

10. The use according to claim 8, wherein the composition is present in the personal care product in an amount of 20% by weight or more.