A modified xanthan gum suitable for alcohol-free washing products and its preparation method and application

Abstract

The invention discloses a modified xanthan gum suitable for alcohol-based wash-free products, a preparation method and an application thereof, and belongs to the field of polymer materials. The invention comprises the following steps: a xanthan gum solution with a pH value of 3-5 is reacted with a polyglycerol-10 oleate aqueous solution at 50-75° C. for 6 hours, the reaction is terminated, the pH value is adjusted to 7-8 after decolorization and filtration, and the modified xanthan gum powder is obtained by drying. After the reaction, the polyglycerol-10 oleate is grafted and polymerized onto the xanthan gum, so that the obtained modified xanthan gum can effectively thicken in a system with a high ethanol content and keep the system transparent, and has a moisturizing effect.

Description

Technical Field

[0001] The invention belongs to the field of polymer materials, and in particular relates to a modified xanthan gum suitable for alcohol-based wash-free products, and a preparation method and application thereof. Background Art

[0002] Disposable products containing 70-75% (V / V) alcohol have always been the most commonly used category of personal disinfection and hygiene products, mainly due to their low cost, significant bactericidal and antiviral effects, and readily available raw materials and simple production. Their main ingredients are ethanol, purified water, thickeners and flavors. Thickeners are mostly carbomer, ethyl cellulose (HEC) and hydroxypropyl methylcellulose (HPMC). Carbomer is the most widely used, but organic solvents such as benzene and ethyl acetate are used in the production of carbomer, and they cannot be completely removed. Their use in disposable products (leave-on products) will bring risks of skin irritation and skin absorption of residual organic solvents. Cellulose is less used, mainly because it cannot provide a transparent appearance and refreshing skin feel comparable to carbomer, especially HPMC, which has a film-forming and sticky feel. If added in larger amounts, it will rub into mud, resulting in a poor consumer experience. Some natural colloids such as xanthan gum are not ethanol-resistant, and it is difficult to effectively thicken the system and achieve an ideal viscosity in 70-75% (V / V) disposable products.

[0003] Xanthan gum is a soluble polysaccharide derived from microbial fermentation. It has good water solubility, shear thixotropy, acid-base stability and other characteristics. It is widely used in food, medicine and personal care products. Xanthan gum is not tolerant to ethanol, and it is difficult to effectively thicken the system and achieve the ideal viscosity in 70-75% (V / V) disposable products. At present, the modification processes of xanthan gum mainly include cross-linking, grafting, esterification, etc., and there is no research report on xanthan gum suitable for high-content ethanol system. Summary of the invention

[0004] Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a modified xanthan gum suitable for alcohol-based wash-free products and a preparation method and application thereof, so that it can effectively thicken in a system with a high ethanol content and keep the system transparent.

[0005] Technical solution: To achieve the above purpose, the present invention adopts the following technical solution:

[0006] A method for preparing modified xanthan gum suitable for alcohol-based wash-free products comprises the following steps:

[0007] (1) preparing a 0.5%-2% (W / W) xanthan gum aqueous solution, stirring to dissolve, and adjusting the pH to 3-5 with a hydrochloric acid aqueous solution;

[0008] (2) mixing and dissolving polyglycerol-10 oleate and purified water in a ratio of 1:20-1:40 (W / W);

[0009] (3) adding the solution obtained in step (2) to the solution obtained in step (1), stirring slowly while adding, reacting at 50-75° C. for 6 hours, then cooling to room temperature in an ice bath to terminate the reaction;

[0010] (4) Decolorization by activated carbon adsorption, filtration and adjustment of pH to 7-8 with NaOH solution;

[0011] (5) Sterilize and vacuum dry to obtain modified xanthan gum powder.

[0012] In the above steps, the average molecular weight of xanthan gum in step (1) is 100,000-500,000 Da; the monoester content of polyglycerol-10 oleate in step (2) is greater than 80%; the glycerol of polyglycerol-10 oleate is of natural origin or petroleum origin, and the oleic acid is of plant origin (palm oil, coconut oil, sunflower seed oil, etc.) or petroleum origin.

[0013] Beneficial effects: The present invention provides a modified xanthan gum suitable for alcohol-based wash-free products and a preparation method and application thereof, which has the following effects compared with the prior art:

[0014] 1) The HLB value of polyglycerol-10 oleate is 13.5, contains 11 hydroxyl groups, and has a solubility of 8.6 g / 100 in ethanol. Xanthan gum grafted with polyglycerol-10 oleate can be more soluble in ethanol, so it can be used in systems with high ethanol content (70-75% V / V), effectively thickening and maintaining the transparency of the system;

[0015] 2) Polyglyceryl-10 oleate has affinity to the skin and gives the skin a long-lasting moisturizing feel. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Attached Figure 1 It is the infrared spectrum of the modified xanthan gum obtained in the example of the present invention, wherein 1-xanthan gum, 2-modified xanthan gum. DETAILED DESCRIPTION

[0017] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0018] Experimental materials: xanthan gum powder, polyglycerol-10 oleate, NaOH, hydrochloric acid

[0019] Example 1

[0020] Take xanthan gum with an average molecular weight of 300,000, prepare a 1% xanthan gum aqueous solution, stir and dissolve, adjust the pH to 3.5 with a hydrochloric acid aqueous solution, mix and dissolve polyglycerol-10 oleate and purified water in a ratio of 1:30 (W / W), add 100g of polyglycerol-10 oleate solution to 250g of xanthan gum solution, stir slowly while adding, react at 65°C for 6 hours, cool to room temperature in an ice bath to terminate the reaction; add activated carbon for adsorption and decolorization, filter and adjust the pH to 7-8 with a NaOH solution, sterilize and vacuum dry to obtain modified xanthan gum powder.

[0021] Example 2

[0022] Take xanthan gum with an average molecular weight of 300,000, prepare a 2% xanthan gum aqueous solution, stir and dissolve, and adjust the pH to 3.5 with a hydrochloric acid aqueous solution; mix and dissolve polyglycerol-10 oleate and purified water in a ratio of 1:30 (W / W); add 100g of polyglycerol-10 oleate solution to 250g of xanthan gum solution, slowly stir while adding, react at 65°C for 6 hours, and cool to room temperature in an ice bath to terminate the reaction; add activated carbon for adsorption and decolorization; filter and adjust the pH to 7-8 with a NaOH solution; sterilize and vacuum dry to obtain modified xanthan gum powder.

[0023] Example 3

[0024] Take xanthan gum with an average molecular weight of 300,000, prepare a 1% xanthan gum aqueous solution, stir to dissolve, and adjust the pH to 3.5 with a hydrochloric acid aqueous solution; mix and dissolve polyglycerol-10 oleate and purified water in a ratio of 1:20 (W / W), add 100g of polyglycerol-10 oleate solution to 250g of xanthan gum solution, slowly stir while adding, react at 65°C for 6 hours, cool to room temperature in an ice bath to terminate the reaction; add activated carbon for adsorption and decolorization, filter and adjust the pH to 7-8 with a NaOH solution, sterilize and vacuum dry to obtain modified xanthan gum powder.

[0025] Example 4

[0026] Take xanthan gum with an average molecular weight of 500,000, prepare a 1% xanthan gum aqueous solution, stir to dissolve, and adjust the pH to 3.5 with a hydrochloric acid aqueous solution; mix and dissolve polyglycerol-10 oleate and purified water in a ratio of 1:30 (W / W); add 100g of polyglycerol-10 oleate solution to 250g of xanthan gum solution, slowly stir while adding, and react at 65°C for 6 hours; cool to room temperature in an ice bath to terminate the reaction; add activated carbon for adsorption and decolorization, filter and adjust the pH to 7-8 with a NaOH solution; sterilize and vacuum dry to obtain modified xanthan gum powder.

[0027] Example 5

[0028] Take xanthan gum with an average molecular weight of 300,000, prepare a 1% xanthan gum aqueous solution, stir to dissolve, and adjust the pH to 3.5 with a hydrochloric acid aqueous solution; mix and dissolve polyglycerol-10 oleate and purified water in a ratio of 1:40 (W / W); add 100g of polyglycerol-10 oleate solution to 250g of xanthan gum solution, slowly stir while adding, and react at 65°C for 6 hours; cool to room temperature in an ice bath to terminate the reaction; add activated carbon for adsorption and decolorization, filter and adjust the pH to 7-8 with a NaOH solution; sterilize and vacuum dry to obtain modified xanthan gum powder.

[0029] Infrared spectroscopy characterization

[0030] The structure of thickened modified xanthan gum was analyzed using a Fourier transform infrared spectrometer: the sample was dried and ground, then pressed into a translucent sheet, and the sheet was placed on a Fourier transform near infrared spectrometer at 4000 cm -1 ~400cm -1 Scan within the range to obtain its infrared spectrum. Figure 1 As shown in the figure, the large and broad absorption peaks between 3300 cm-1 and 3700 cm-1 are the stretching vibration peaks of -OH in xanthan gum molecules and -OH in polyglycerol; -1 It is the absorption peak of C=O in oleate, and 1640cm-1 is the absorption peak of oleic acid C=C; 2900cm -1 ~2960cm -1 These are the stretching vibration peaks of methyl and methylene groups, indicating that polyglycerol-10 oleate is grafted onto xanthan gum.

[0031] Thickening and transparency test

[0032] The hand-free gel was prepared according to the formula in Table 1. The viscosity and transmittance were measured after standing and centrifuging to defoam. The viscosity test was carried out using a Brookfield RVDV2T, rpm18, and the viscosity was measured at 20°C. The viscosity of each sample was measured 3 times, and the results were averaged. The results are shown in Table 2.

[0033] Transmittance detection method: measured with a spectrophotometer at 25°C and 550nm visible light. The results are shown in Table 2.

[0034] The results show that the viscosity of the product with modified xanthan gum added in Examples 1-5 is significantly higher than that of the product with ordinary xanthan gum (Comparative Example), and the system can maintain excellent transparency. The grafting ratio of Example 5 is relatively low, and the transparency and thickening effect are lower than those of Examples 1-4. This indicates that as the grafting ratio of polyglycerol-10 oleate increases, the transmittance and thickening effect will increase.

[0035] Table 1 75% V / V hand sanitizer gel formula

[0036] Element W / W, % 1 Purified water 38.5 2 Anhydrous ethanol 60 3 Xanthan gum 1.5

[0037] Table 2 Thickening and light transmittance test results

[0038] Test items Comparative Example Example 1 Example 2 Example 3 Example 4 Example 5 Light transmittance 92.0％ 99.1％ 99.0％ 99.1％ 99.2％ 96.5％ Viscosity 1430cps 3415cps 3490cps 4700cps 3840cps 2725cps

[0039] Skin feel test

[0040] Additional formula contribution - maintaining sebum levels

[0041] Detection of sebum content is the evaluation index, 40 volunteers (age 24-48, 28 women, 12 men), skin barrier health is normal. Test site: left and right hand back, left hand smears the disposable gel of the modified xanthan gum configuration obtained in Example 2, and the right hand smears the disposable gel of the common xanthan gum configuration of the comparative example, and the application amount is 2g. Use once in the 2nd, 4th, 6th, 8th, 12th, and 24th hours, and measure sebum content 3 minutes after using the disposable hand gel. Test instrument Sebumeter (skin oil tester), the results are shown in Table 3.

[0042] Table 3 Test results of hand sebum content after using hand sanitizer gel multiple times

[0043]

[0044] It can be seen from Table 3 that the modified xanthan gum of the present invention can effectively maintain the sebum content. This is because olein is a component naturally present in sebum, and polyglycerol-10 olein has good skin affinity and can adhere to the skin to protect the skin from transepidermal water loss. In hand-free gel products using ordinary xanthan gum, a large amount of water is taken away due to the volatilization of ethanol, and ethanol also destroys the sebum components, causing the hands to become dry and cracked.

[0045] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing modified xanthan gum suitable for alcohol-based wash-free products, characterized in that: The steps include: (1) preparing a xanthan gum aqueous solution and adjusting the pH to 3-5; (2) preparing a polyglycerol-10 oleate aqueous solution; (3) adding the solution obtained in step (2) to the solution obtained in step (1), stirring slowly while adding, and reacting at 50-75° C. for 6 hours, then terminating the reaction; (4) After decolorization and filtration, adjust the pH to 7-8; (5) Sterilize and vacuum dry to obtain modified xanthan gum powder.

2. The method for preparing the modified xanthan gum suitable for alcohol-based wash-free products according to claim 1, characterized in that: The W / W concentration of the xanthan gum aqueous solution in step (1) is 0.5%-2%.

3. The preparation method of the modified xanthan gum suitable for alcohol-based wash-free products according to claim 1 or 2, characterized in that, The average molecular weight of the xanthan gum in step (1) is 100,000-500,000 Da.

4. The method for preparing the modified xanthan gum suitable for alcohol-based wash-free products according to claim 1 or 2, characterized in that: In step (1), hydrochloric acid is used to adjust the pH.

5. The method for preparing modified xanthan gum suitable for alcohol-based wash-free products according to claim 1, characterized in that: The W / W ratio of polyglycerol-10 oleate to purified water in the polyglycerol-10 oleate aqueous solution in step (2) is 1:20-1:

40.

6. The method for preparing the modified xanthan gum suitable for alcohol-based wash-free products according to claim 1 or 5, characterized in that: The monoester content of the polyglycerol-10 oleate in step (2) is greater than 80%.

7. The method for preparing modified xanthan gum suitable for alcohol-based wash-free products according to claim 1, characterized in that: In step (3), the reaction is terminated by cooling to room temperature in an ice bath.

8. The method for preparing modified xanthan gum suitable for alcohol-based wash-free products according to claim 1, characterized in that: In step (4), NaOH solution is used to adjust the pH.

9. The modified xanthan gum suitable for alcohol-based wash-free products prepared by the method according to any one of claims 1 to 8 is characterized in that: The modified xanthan gum is xanthan gum grafted with polyglycerol-10 oleate.

10. The use of modified xanthan gum suitable for alcohol-based wash-free products according to claim 9, characterized in that: The modified xanthan gum is applied to a system with 70-75% V / V ethanol content.

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