A pH colorimetric reagent and its preparation method, and a wet toilet paper and its preparation method.

Abstract

This invention relates to the field of hygiene product technology, specifically to a pH colorimetric agent and its preparation method, and a nursing toilet paper and its preparation method. The agent comprises a complex of anthocyanins and lactic acid, denoted as ALA. The preparation method includes the following steps: S1. Mixing anthocyanin solution and lactic acid solution, and stirring the mixture under light-protected conditions; S2. After the reaction is complete, removing uncomplexed lactic acid to obtain an ALA solution. The nursing toilet paper includes a carrier and a pH colorimetric agent loaded on the carrier. After the pH colorimetric agent binds to the carrier of the toilet paper, it tends to be colorless between pH 4 and 7. Outside this range, a more noticeable color change occurs, giving the toilet paper an inflammation indication function. Furthermore, it tends to be colorless within the optimal pH range for the toilet paper, resulting in high consumer acceptance.

Description

Technical Field

[0001] This invention relates to the field of hygiene products technology, and more specifically, to a pH colorimetric agent and its preparation method, and a wet toilet paper and its preparation method. Background Technology

[0002] Women's urinary system health is closely related to daily care. Due to their physiological structure, women have short urethras that are close to the vagina and perianal area, making them more susceptible to urinary tract infections (UTIs) or vulvitis caused by bacteria ascending from the urethra. Globally, approximately 50%-60% of women will experience at least one UTI in their lifetime, with a recurrence rate as high as 30%. Under healthy conditions, urine pH is stable between 4 and 7 (normal metabolic range). However, pathogen infections (such as E. coli and Candida) or inflammatory responses can cause an abnormally high pH (pH > 7 in UTIs). This biochemical indicator can serve as an early warning signal.

[0003] While traditional wet toilet paper enhances the cleaning experience, its function is limited to physical wiping and cannot detect real-time pH changes in the urinary tract, making it difficult for women to detect latent infections or early signs of inflammation in time. Studies have shown that 30% of asymptomatic bacteriuria patients experience delayed intervention due to the lack of obvious symptoms, eventually developing into pyelonephritis.

[0004] Anthocyanins, as the most widely studied natural pigments, not only possess excellent pH-based color development capabilities but also enjoy high popularity for their antioxidant properties. Under strongly acidic conditions, anthocyanin solutions primarily exist as flavonoid salt ions, exhibiting a red color. As the pH increases, the cations on the C-epoxide undergo a hydration reaction, transforming into a colorless methanolic pseudobase. As the pH gradually approaches alkalinity, its main structure becomes a quinoline base, resulting in a blue / purple color. When the pH further increases, the chalcone structure becomes dominant, resulting in a yellow color. Because anthocyanins are highly sensitive to pH, they appear red in solution at pH < 3, pink at pH 3-6, purple at neutral, and blue at pH > 7, making it difficult for them to become colorless. Secondly, when combined with a wet toilet paper carrier, they only tend to be colorless at pH 5-6, a narrow range that does not match the normal pH range of urine. They may also show color within the normal pH range of urine, interfering with the assessment of inflammation. Finally, consumers tend to prefer colorless wet toilet paper, while the optimal pH for wet toilet paper is 5.5-6.5. When the pH exceeds 6, the wet toilet paper may show color, which is not suitable for consumer needs. Furthermore, when the pH of wet toilet paper fluctuates within the normal range, inconsistencies in color and poor batch-to-batch consistency may occur.

[0005] Therefore, a pH-based colorimetric agent is provided, which is combined with the carrier of wet toilet paper, making the wet toilet paper colorless at pH 4-7, and exhibiting a more obvious color change outside this range, thus providing an inflammation indication function. This is of great significance for the intelligent application of wet toilet paper.

[0006] In view of this, the present invention is hereby proposed. Summary of the Invention

[0007] The primary objective of this invention is to provide a pH colorimetric agent that, when combined with a carrier of wet toilet paper, tends to be colorless between pH 4 and 7, and exhibits a more pronounced color change outside this range, thereby enabling the wet toilet paper to have an inflammation indication function. Furthermore, it tends to be colorless within the optimal pH range for wet toilet paper, resulting in high consumer acceptance.

[0008] The second objective of this invention is to provide a method for preparing the pH colorimetric reagent as described above, which is simple and easy to implement.

[0009] A third objective of the present invention is to provide a nursing wet toilet paper comprising the pH color indicator as described above, wherein the wet toilet paper has an inflammation indication function and tends to be colorless under normal conditions.

[0010] A fourth objective of this invention is to provide a method for preparing the wet toilet paper described above.

[0011] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0012] A pH colorimetric reagent comprising a complex of anthocyanin and lactic acid, denoted as ALA; the raw materials of the pH colorimetric reagent include anthocyanin and lactic acid, wherein the mass ratio of anthocyanin to lactic acid is 1-2.7:1-3.3.

[0013] Preferably, at least a portion of the surface of the ALA is coated with cyclodextrin.

[0014] A method for preparing a pH colorimetric reagent as described above includes the following steps:

[0015] S1. Mix the anthocyanin solution and lactic acid solution, and stir the mixture under light-protected conditions;

[0016] S2. After the reaction is complete, remove the uncomplexed lactic acid to obtain an ALA solution.

[0017] Preferably, the step S2 is followed by the following step:

[0018] S3. Mix the cyclodextrin solution and the ALA solution, and then perform ultrasonic treatment and rotary mixing in sequence under light-protected conditions. Finally, freeze-dry to obtain cyclodextrin-encapsulated ALA, denoted as CD@ALA.

[0019] Preferably, in step S1, the mass ratio of anthocyanin to lactic acid is 1-2.7:1-3.3.

[0020] Preferably, in step S1, the stirring speed is 200-400 rpm and the stirring time is 20-40 min.

[0021] Preferably, in step S1, the anthocyanins are extracted from fresh cranberries using ethanol as the extraction solvent.

[0022] Preferably, in step S2, uncomplexed lactic acid is removed by dialysis using a dialysis bag.

[0023] Preferably, in step S3, the mass ratio of the cyclodextrin to the ALA is 1:1 to 1:3.

[0024] Preferably, in step S3, the ultrasonic treatment time is 8-15 minutes and the ultrasonic treatment power is 40-60W.

[0025] Preferably, in step S3, the rotational speed of the rotary mixer is 40-50 r / min, and the stirring time is 12-15 h.

[0026] A type of wet toilet paper, comprising a carrier and a pH colorimetric agent loaded on the carrier;

[0027] The pH colorimetric agent is the pH colorimetric agent described in any one of the foregoing embodiments or the pH colorimetric agent prepared by the preparation method described in any one of the foregoing embodiments.

[0028] Preferably, the wet toilet paper further includes a solution loaded on the carrier;

[0029] The prepared solution comprises, by weight percentage, 0.5%-1.3% soothing ingredients, 0.75%-1.5% preservative ingredients, 0.5%-2% moisturizing ingredients, 0.005%-0.01% pH adjuster, 0.1%-0.2% solubilizer, and the balance being water.

[0030] Preferably, the soothing ingredients, by mass percentage in the prepared solution, include 0.1%-0.2% bisabolol, 0.2%-0.5% purslane extract, 0.1%-0.3% dipotassium glycyrrhizate, and 0.1%-0.3% oat β-glucan.

[0031] Preferably, the preservative components, by mass percentage in the prepared solution, include 0.5%-1% of 1,2-hexanediol, 0.1%-0.3% of octyl glycol, and 0.15%-0.2% of phenoxyethanol.

[0032] Preferably, the moisturizing ingredient includes at least one of sorbitol, propylene glycol, and butylene glycol.

[0033] Preferably, the pH adjuster includes citric acid.

[0034] Preferably, the solubilizer comprises CO40.

[0035] Preferably, the pH of the prepared solution is 5.5-6.5.

[0036] Preferably, the method for preparing the solution includes the following steps:

[0037] Heat the water to 40-50°C, add CO40 and the bisabolol, stir until completely dissolved, add the remaining components, and stir to mix; after cooling, adjust the pH to 5.5-6.5 using the pH adjuster.

[0038] The method for preparing the nursing wet toilet paper according to any one of the foregoing embodiments includes the following steps:

[0039] a. Soak the carrier in deionized water and then air dry it for later use;

[0040] b. Disperse the pH colorimetric agent in water, add 2D resin, MgCl2 and JFC penetrant, and stir evenly to obtain an impregnation solution; immerse the carrier dried in step a into the impregnation solution, at 30-50℃, at a solid-liquid mass ratio of 1:25-35 for 1-2 hours, and then dry to obtain the colorimetric carrier, which should be stored away from light.

[0041] c. Apply the solution to the chromogenic support to obtain the final product.

[0042] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0043] Anthocyanins contain multiple hydroxyl and phenolic hydroxyl active groups, which can form a dynamic complex structure with lactic acid through hydrogen bonds, causing a shift in the color change threshold. When combined with the wet toilet paper carrier, it can make the wet toilet paper tend to be colorless within the normal pH range (4-7), meeting consumer needs. However, there will be a more obvious color change when it exceeds this range. When the pH of urine changes abnormally due to inflammation or other conditions, a color change will occur, giving the wet toilet paper an intelligent inflammation indication function. Attached Figure Description

[0044] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0045] Figure 1 This is a color change diagram of wet toilet paper under different pH conditions in Application Example 1 of the present invention. Detailed Implementation

[0046] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0047] A first aspect of the present invention provides a pH colorimetric agent comprising a complex of anthocyanin and lactic acid, denoted as ALA; the raw materials of the pH colorimetric agent include anthocyanin and lactic acid, and the mass ratio of anthocyanin to lactic acid in the raw materials is 1-2.7:1-3.3, for example, it can be any one value or a range of any two values ​​among 1:3.3, 1:2.2, 1:1, 1.8:1, and 2.7:1.

[0048] Anthocyanins contain multiple hydroxyl and phenolic hydroxyl active groups, which can form a dynamic complex structure with lactic acid through hydrogen bonds. This can change the color change threshold and broaden the colorless range. Using the complex of anthocyanins and lactic acid as a pH color indicator, after being combined with the carrier of wet toilet paper, the wet toilet paper can become colorless within the normal pH range of urine (4-7), which is highly acceptable to consumers. Furthermore, it can quickly develop color when urine pH changes abnormally due to inflammation or other conditions, giving the wet toilet paper an intelligent inflammation indication function. This is of great significance for the intelligent application of wet toilet paper.

[0049] In some specific embodiments of the present invention, at least a portion of the surface of the ALA is coated with cyclodextrin. Cyclodextrin coating stabilizes anthocyanins, prolonging the fading time and increasing the color development duration.

[0050] A second aspect of the present invention provides a method for preparing the pH colorimetric reagent described in any of the foregoing embodiments, comprising the following steps:

[0051] S1. Mix the anthocyanin solution and lactic acid solution, and stir the mixture under room temperature and dark conditions.

[0052] S2. After the reaction is complete, remove the uncomplexed lactic acid to obtain an ALA solution.

[0053] The method of this invention is simple, with mild and controllable conditions, making it easy to mass-produce. The pH color indicator prepared can be colorless in the normal pH range of urine when used in wet toilet paper, and produce a more obvious color change when the urine pH is abnormal. It has both an inflammation indication function and can meet the public's color requirements for normal wet toilet paper.

[0054] In some specific embodiments of the present invention, the following steps are included after step S2:

[0055] S3. Mix the cyclodextrin solution and the ALA solution, sonicate them under light-protected conditions, then mix them by rotation on a disc mixer, and then freeze-dry them to obtain cyclodextrin-encapsulated ALA, denoted as CD@ALA.

[0056] Encapsulation with cyclodextrin improves the stability of anthocyanins, prolongs the fading time of wet toilet paper, increases the color development time, and makes observation easier. The ALA solution obtained in step S2 can be used directly to prepare CD@ALA, or its concentration can be adjusted before use, or it can be dried and stored, and then reconstituted into a solution for use.

[0057] In some specific embodiments of the present invention, in step S1, the mass ratio of anthocyanin to lactic acid is 1-2.7:1-3.3. For example, it can be any one value or a range of any two values ​​among 1:3.3, 1:2.2, 1:1, 1.8:1, and 2.7:1. The color response threshold of the pH colorimetric agent prepared within this ratio range is in the ideal variation range. When used on wet toilet paper, it can make the wet toilet paper tend to be colorless in the normal urine pH range (pH 4-7) and produce corresponding color changes when the urine pH is abnormal.

[0058] In some specific embodiments of the present invention, the anthocyanin solution used in step S1 can be an aqueous solution of anthocyanin or a PBS solution containing anthocyanin. For example, the anthocyanin solution is a 0.95 mg / mL anthocyanin PBS solution; the lactic acid solution used is an aqueous solution of lactic acid. For example, the lactic acid solution used is an 88% lactic acid solution.

[0059] In some specific embodiments of the present invention, in step S1, the stirring speed is 200-400 rpm, for example, it can be any one value or a range of any two values ​​among 200 rpm, 250 rpm, 300 rpm, 350 rpm, and 400 rpm; the stirring time is 20-40 min, for example, it can be any one value or a range of any two values ​​among 20 min, 25 min, 30 min, 35 min, and 40 min.

[0060] In some specific embodiments of the present invention, in step S1, the anthocyanins used are extracted from fresh cranberries using ethanol as the extraction solvent.

[0061] In some specific embodiments of the present invention, the anthocyanin extraction method includes the following steps:

[0062] S11. Cell disruption: After removing the stems from fresh cranberries, rinse them with deionized water at 4°C, drain them, and then mechanically disrupt them at low temperature (4°C) until the particle size is ≤2 mm. Add 0.1%-0.12% ascorbic acid (w / w) to the disruption solution and store them away from light.

[0063] S12. Preparation of extraction solution: Prepare a 60%-70% ethanol solution and adjust the pH to 2.5 with citric acid;

[0064] S13. Extraction: The material-to-liquid ratio is 1:15 (w / v). Add 0.05% ethyl maltol (w / v, i.e., the mass ratio of ethyl maltol to the volume ratio of the extract). Stir at 150-300 rpm for 30-50 minutes at 70°C.

[0065] S14. Filtration and Concentration: The filtrate is concentrated under reduced pressure using a rotary evaporator after vacuum filtration through a filter membrane.

[0066] S15. After pre-cooling, the crude anthocyanin extract is obtained by freeze-drying;

[0067] S16. Purification: Pack a column with 500 mL HPD600 macroporous resin, dilute the crude anthocyanin extract with water to obtain a loading solution with a volume of 700-1000 mL and a mass concentration of 10-12 mg / mL (anthocyanin content). Control the elution flow rate to 2.0-3.0 BV / h, then elute with 550-700 mL of 60%-75% ethanol, collect the eluent, concentrate and dry it.

[0068] In some specific embodiments of the present invention, in step S2, uncomplexed lactic acid is removed by dialysis through a dialysis bag. Small molecule lactic acid is dialyzed out, while the complex remains in the bag. As an example, a 0.5 kDa dialysis bag can be used for dialysis, and the dialysis time is 4-8 hours. For example, it can be any point value or a range of any two points from 4 hours to 8 hours.

[0069] In some specific embodiments of the present invention, in step S3, the mass ratio of cyclodextrin to ALA is 1:1 to 1:3. For example, it can be any one value or a range of any two values ​​from 1:1, 1:1.5, 1:2, 1:2.5, 1:3.

[0070] In some specific embodiments of the present invention, in step S3, the ultrasonic treatment time is 8-15 min, for example, it can be any one value or a range of any two values ​​among 8 min, 10 min, 12 min, and 15 min; the ultrasonic treatment power is 40-60 W, for example, it can be any one value or a range of any two values ​​among 40 W, 45 W, 50 W, 55 W, and 60 W.

[0071] In some specific embodiments of the present invention, in step S3, the mixing speed (i.e., the speed of the disc mixer) is 40-50 r / min, for example, it can be any one value or a range of any two values ​​among 40 r / min, 42 r / min, 45 r / min, 48 r / min, and 50 r / min; the stirring and mixing time is 12-15 h, for example, it can be any one value or a range of any two values ​​among 12 h, 13 h, 14 h, and 15 h.

[0072] A third aspect of the present invention provides a nursing wet toilet paper, comprising a carrier and a pH colorimetric agent loaded on the carrier;

[0073] The pH colorimetric agent used is the pH colorimetric agent described in any of the foregoing embodiments or the pH colorimetric agent prepared by the method described in any of the foregoing embodiments; as an example, the carrier used is spunlace nonwoven fabric.

[0074] The wet toilet paper provided by this invention has an inflammation indication function and tends to be colorless under normal pH conditions, making it highly acceptable to the public.

[0075] In some specific embodiments of the present invention, the nursing wet toilet paper further includes a liquid loaded on a carrier;

[0076] The prepared solution, by weight percentage, includes 0.5%-1.3% soothing ingredients, 0.75%-1.5% preservative ingredients, 0.5%-2% moisturizing ingredients, 0.005%-0.01% pH adjuster, 0.1%-0.2% solubilizer, and the balance being water.

[0077] The solution uses an anti-inflammatory and soothing formula system, which gives the wet toilet paper its inflammatory color-developing properties while also providing anti-inflammatory and soothing effects.

[0078] In some embodiments, typically but not limitingly, for example, the mass percentage of the soothing component in the solution can be any one value or a range of any two values ​​from 0.5%, 0.7%, 0.9%, 1%, and 1.3%; the mass percentage of the preservative component can be any one value or a range of any two values ​​from 0.75%, 1.0%, 1.2%, 1.4%, and 1.5%; the mass percentage of the moisturizing component can be any one value or a range of any two values ​​from 0.5%, 1%, 1.5%, and 2%; the mass percentage of the pH adjuster can be any one value or a range of any two values ​​from 0.005%, 0.006%, 0.008%, and 0.01%; and the mass percentage of the solubilizer can be any one value or a range of any two values ​​from 0.1%, 0.12%, 0.15%, 0.18%, and 0.2%. As an example, deionized water is used to avoid impurities.

[0079] In some specific embodiments of the present invention, the soothing ingredients used, by mass percentage in the prepared solution, include 0.1%-0.2% bisabolol, 0.2%-0.5% purslane extract, 0.1%-0.3% dipotassium glycyrrhizate, and 0.1%-0.3% oat β-glucan. Bisabolol has anti-inflammatory and soothing effects, and can repair sensitive skin; purslane extract is a natural anti-allergic ingredient containing alkaloids and polysaccharides, which can relieve itching and burning sensations; dipotassium glycyrrhizate is an anti-inflammatory ingredient that can inhibit inflammatory factors (such as IL-6 and TNF-α) and relieve redness and swelling; oat β-glucan can repair the skin barrier and enhance the tolerance of sensitive skin; oat β-glucan is preferably added in the form of an aqueous solution.

[0080] In some embodiments, typically but not limitingly, for example, the mass percentage of bisabolol in the solution can be any one value or a range of any two values ​​from 0.1%, 0.12%, 0.15%, 0.18%, and 0.2%; the mass percentage of purslane extract in the solution can be any one value or a range of any two values ​​from 0.2%, 0.3%, 0.4%, and 0.5%; the mass percentage of dipotassium glycyrrhizate in the solution can be any one value or a range of any two values ​​from 0.1%, 0.15%, 0.2%, 0.25%, and 0.3%; and the mass percentage of oat β-glucan in the solution can be any one value or a range of any two values ​​from 0.1%, 0.15%, 0.2%, 0.25%, and 0.3%.

[0081] In some specific embodiments of the present invention, the preservative components used, based on their mass percentage in the prepared solution, include 0.5%-1% 1,2-hexanediol, 0.1%-0.3% octaneglycol, and 0.15%-0.2% phenoxyethanol. Using a polyol compound for preservatives provides higher safety. Typically, but not limitingly, for example, the mass percentage of 1,2-hexanediol in the prepared solution can be any single value or a range of any two values ​​from 0.5%, 0.6%, 0.8%, and 1%; the mass percentage of octaneglycol in the prepared solution can be any single value or a range of any two values ​​from 0.1%, 0.15%, 0.2%, 0.25%, and 0.3%; and the mass percentage of phenoxyethanol in the prepared solution can be any single value or a range of any two values ​​from 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, and 0.2%.

[0082] In some specific embodiments of the present invention, the moisturizing ingredients used include at least one of sorbitol, propylene glycol, and butylene glycol. Sorbitol is a natural moisturizer that can reduce friction and irritation and maintain skin hydration. Propylene glycol, as a solvent and moisturizer, helps dissolve the active ingredients and inhibits water evaporation, while also possessing antibacterial properties. Butylene glycol provides gentle moisturizing and also has auxiliary preservative effects.

[0083] In some specific embodiments of the present invention, the pH adjuster used includes citric acid, which is used to adjust the pH value of the solution.

[0084] In some specific embodiments of the present invention, the solubilizer used includes CO40.

[0085] In some specific embodiments of the present invention, the pH of the prepared solution is 5.5-6.5.

[0086] In some specific embodiments of the present invention, the method for preparing the solution includes the following steps:

[0087] Heat the water to 40-50℃, add CO40 and bisabolol, stir until completely dissolved, then add the other ingredients in sequence and stir for 20-30 minutes; cool to room temperature, and finally adjust the pH to 5.5-6.5 with a pH adjuster.

[0088] A fourth aspect of the present invention provides a method for preparing nursing wet toilet paper according to any one of the foregoing embodiments, comprising the following steps:

[0089] a. Cut the carrier (such as spunlace nonwoven fabric) into a suitable size, soak it in deionized water for 20-40 minutes, and then air dry it for later use;

[0090] b. Disperse the pH colorimetric reagent in water to prepare a 5%-10% (w / v) suspension. Stir at 50-70℃ until completely dissolved. Add 2D resin, MgCl2 and JFC penetrant, and stir evenly to obtain an impregnation solution. Immerse the carrier dried in step a into the impregnation solution. At 30-50℃, at a solid-liquid mass ratio of 1:25-35, impregnate for 1-2 hours. Then, dry at 70-80℃ to obtain the colorimetric carrier. Store at room temperature away from light.

[0091] c. Apply the prepared solution to the chromogenic support to obtain the final product.

[0092] Step a removes surface impurities and induces fiber swelling. In step b, the 2D resin acts as a crosslinking agent, penetrating between the fibers and pH color developer microcapsules during impregnation. It forms chemical bonds or intermolecular forces with the active groups on the microcapsule walls and fibers, thereby fixing the microcapsules onto the fabric. MgCl2 and JFC penetrants promote crosslinking.

[0093] In some specific embodiments of the present invention, in the impregnation solution prepared in step b, the final concentration of the 2D resin is 18.75%-37.5% (w / v), for example, it can be any one value or a range of any two values ​​from 18.75%, 20%, 22%, 25%, 27.5%, 30%, 32.5%, 35%, 37.5%; the final concentration of MgCl2 is 3.75%-7.5%, for example, it can be any one value or a range of any two values ​​from 3.75%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%; the final concentration of JFC penetrant is 0.25%-0.5%, for example, it can be any one value or a range of any two values ​​from 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%.

[0094] In some embodiments, typically but not limitingly, for example, the immersion temperature in step b can be any one value or a range of any two values ​​from 30°C, 35°C, 40°C, 45°C, and 50°C; the solid-liquid mass ratio during immersion can be any one value or a range of any two values ​​from 1:25, 1:28, 1:30, 1:32, and 1:35; the immersion time can be any one value or a range of any two values ​​from 1h, 1.2h, 1.5h, 1.8h, and 2h; and the drying temperature can be any one value or a range of any two values ​​from 70°C, 72°C, 75°C, 78°C, and 80°C.

[0095] The following detailed description of some embodiments of the present invention is provided in conjunction with specific examples. Unless otherwise specified, all raw materials used in the embodiments can be obtained commercially available.

[0096] Example 1

[0097] (1) Extraction of anthocyanins

[0098] a. Cell disruption: After removing the stems from fresh cranberries, rinse them twice quickly with deionized water at 4°C, drain them, and then mechanically disrupt them at low temperature (4°C) until the particle size is ≤2 mm. Add 0.1% ascorbic acid (w / w) to the disruption solution and store them away from light.

[0099] b. Preparation of extraction solution: Prepare a 65% ethanol solution and adjust the pH to 2.5 using 10% citric acid;

[0100] c. Extraction: The material-to-liquid ratio is 1:15 (w / v), add 0.05% ethyl maltol (w / v), stir at 70℃ for 30 min, and stir at 200 rpm;

[0101] d. Filtration and concentration: The filtrate was filtered under vacuum through a 0.45 μm filter membrane, and then concentrated under reduced pressure for 30 min using a rotary evaporator at 40 °C.

[0102] e. Pre-cool at -20℃ for 4 hours, then freeze-dry at -50℃, 0.1MPa for 12 hours to obtain crude anthocyanin extract;

[0103] f. Purification: Pack a column with 500 mL of HPD600 macroporous resin, dilute the crude anthocyanin extract with water to obtain a loading solution with a volume of 800 mL and a mass concentration of 10 mg / mL (anthocyanin content), and an elution flow rate of 2.0 BV / h. Then, elute with 600 mL of 75% ethanol, collect the eluent, concentrate and dry it.

[0104] (2) Preparation of pH colorimetric reagent

[0105] S1. Prepare a 0.95 mg / mL anthocyanin PBS solution and an 88% lactic acid solution. Mix them at a mass ratio of anthocyanin to lactic acid of 1:3.3 and stir at 300 rpm in the dark for 30 min at room temperature.

[0106] S2. Dialyze with a 0.5 kDa dialysis bag for 6 hours to remove uncomplexed lactic acid and obtain an ALA solution;

[0107] S3. Using β-cyclodextrin, a 0.2 g / mL cyclodextrin solution was prepared with deionized water as the solvent. The cyclodextrin solution and ALA solution were mixed at a mass ratio of 1:2 (cyclodextrin to ALA). After ultrasonic treatment at 40 W for 10 min under light-protected conditions, the mixture was homogenized at 45 r / min for 12 h on a disc mixer. Subsequently, it was freeze-dried (-50 °C, 0.1 MPa) for 12 h to obtain β-CD@ALA.

[0108] Example 2

[0109] Example 2 is similar to Example 1, except that in step S1, the mass ratio of anthocyanins to lactic acid is 1:2.2, and all other conditions are the same as in Example 1.

[0110] Example 3

[0111] Example 3 is similar to Example 1, except that in step S1, the mass ratio of anthocyanins to lactic acid is 1:1, and all other conditions are the same as in Example 1.

[0112] Example 4

[0113] Example 4 is similar to Example 1, except that in step S1, the mass ratio of anthocyanins to lactic acid is 1.8:1, and all other conditions are the same as in Example 1.

[0114] Example 5

[0115] Example 5 is similar to Example 1, except that in step S1, the mass ratio of anthocyanins to lactic acid is 2.7:1, and all other conditions are the same as in Example 1.

[0116] Example 6

[0117] Example 6 is similar to Example 1, except that cyclodextrin was not coated on the surface of ALA, and all other conditions are the same as in Example 1.

[0118] Application Example 1

[0119] Application Example 1 provides a nursing wet toilet paper, comprising a spunlace nonwoven fabric, a solution loaded on the nonwoven fabric, and a pH colorimetric agent, wherein the pH colorimetric agent is the pH colorimetric agent prepared in Example 1.

[0120] The solution composition by mass percentage is as follows: 0.1% bisabolol, 0.25% purslane extract, 0.2% dipotassium glycyrrhizate, 0.1% oat β-glucan, 0.5% 1,2-hexanediol, 0.275% caprylyl glycol, 0.175% phenoxyethanol, 1% sorbitol, 0.005% citric acid, 0.2% CO40, and the balance being deionized water.

[0121] The preparation of the solution includes the following steps:

[0122] Heat the water to 45°C, add CO40 and bisabolol, stir until completely dissolved, then add the other ingredients in sequence and stir for 20 minutes; cool to room temperature, and finally adjust the pH to 5.5 with a pH adjuster.

[0123] The preparation steps for wet toilet paper are as follows:

[0124] a. Cut the spunlace nonwoven fabric to a suitable size, soak it in deionized water for 30 minutes, and then air dry it for later use;

[0125] b. Prepare a 5% (w / v) suspension of β-CD@ALA prepared in Example 1, stir at 60°C until completely dissolved, add 2D resin (final concentration 18.75%, w / v), MgCl2 (final concentration 3.75%, w / v) and JFC penetrant (final concentration 0.25%, w / v), and stir until homogeneous to obtain an impregnation solution; immerse the carrier dried in step a into the impregnation solution, impregnate at 40°C for 1 hour, with a solid-liquid mass ratio of 1:30, and dry at 80°C to obtain the colored spunlace nonwoven fabric, which should be stored at room temperature away from light;

[0126] c. Mix the color-developing spunlace nonwoven fabric and the solution at a dry-to-wet ratio of 1:2 (by mass). Spray the solution evenly onto the color-developing spunlace nonwoven fabric to obtain the wet toilet paper.

[0127] Application Example 2

[0128] Application Example 2 provides a nursing wet toilet paper, comprising a spunlace nonwoven fabric, a solution loaded on the nonwoven fabric, and a pH colorimetric agent, wherein the pH colorimetric agent is the pH colorimetric agent prepared in Example 2.

[0129] The composition and preparation method of the solution are the same as in Application Example 1.

[0130] The preparation method of the wet toilet paper is similar to that in application example 1, the only difference being the pH colorimetric agent used.

[0131] Application Example 3

[0132] Application Example 3 provides a nursing wet toilet paper, comprising a spunlace nonwoven fabric, a solution loaded on the nonwoven fabric, and a pH colorimetric agent, wherein the pH colorimetric agent is the pH colorimetric agent prepared in Example 3.

[0133] The composition and preparation method of the solution are the same as in Application Example 1.

[0134] The preparation method of the wet toilet paper is similar to that in application example 1, the only difference being the pH colorimetric agent used.

[0135] Application Example 4

[0136] Application Example 4 provides a nursing wet toilet paper, comprising a spunlace nonwoven fabric, a solution loaded on the nonwoven fabric, and a pH colorimetric agent, wherein the pH colorimetric agent is the pH colorimetric agent prepared in Example 4.

[0137] The composition and preparation method of the solution are the same as in Application Example 1.

[0138] The preparation method of the wet toilet paper is similar to that in application example 1, the only difference being the pH colorimetric agent used.

[0139] Application Example 5

[0140] Application Example 5 provides a nursing wet toilet paper, comprising a spunlace nonwoven fabric, a solution loaded on the nonwoven fabric, and a pH colorimetric agent, wherein the pH colorimetric agent is the pH colorimetric agent prepared in Example 5.

[0141] The composition and preparation method of the solution are the same as in Application Example 1.

[0142] The preparation method of the wet toilet paper is similar to that in application example 1, the only difference being the pH colorimetric agent used.

[0143] Application Example 6

[0144] Application Example 6 provides a nursing wet toilet paper, comprising a spunlace nonwoven fabric, a solution loaded on the nonwoven fabric, and a pH colorimetric agent, wherein the pH colorimetric agent is the pH colorimetric agent prepared in Example 6.

[0145] The composition and preparation method of the solution are the same as in Application Example 1.

[0146] The preparation method of the wet toilet paper is similar to that in application example 1, the only difference being the pH colorimetric agent used.

[0147] Comparative Example 1

[0148] Similar to Application Example 1, the only difference is that when preparing the pH colorimetric reagent, lactic acid solution was not added, and anthocyanins encapsulated by cyclodextrin were used directly. All other conditions were the same as in Application Example 1.

[0149] Comparative Example 2

[0150] Similar to Application Example 1, the only difference is that when preparing the pH colorimetric reagent, anthocyanin solution was not added, and lactic acid was directly encapsulated by cyclodextrin. All other conditions were the same as in Application Example 1.

[0151] Comparative Example 3

[0152] Similar to Application Example 1, the only difference is that when preparing the pH colorimetric reagent, the mass ratio of anthocyanins to lactic acid is 4:1, and all other conditions are the same as in Application Example 1.

[0153] Experimental Example 1

[0154] Prepare PBS solutions with different pH values, and drop 300 μL onto the wet toilet paper in Application Examples 1-5 and Comparative Examples 1-3 respectively. Observe the colors that appear, and the results are shown in Table 1.

[0155] Table 1

[0156]

[0157] As shown in Table 1, the wet toilet paper prepared using the pH colorimetric agent prepared by the method of the present invention tends to be colorless within the pH range of 4-7, while there are visually distinguishable color changes outside this range, which is in line with the expected pH color response range. In contrast, the wet toilet paper prepared by directly using anthocyanins encapsulated in cyclodextrin as the pH colorimetric agent in Comparative Example 1 has a narrower colorless range, which is difficult to accurately use for the judgment of inflammation.

[0158] Depend on Figure 1 It is known that the wet toilet paper of the present invention has good pH responsiveness and tends to be colorless in the pH range of 4-7, while there are color changes that can be distinguished by the naked eye outside this range, which is in line with the expected pH color response range.

[0159] Experimental Example 2

[0160] Prepare PBS solutions with different pH values, and drop 300 μL onto the wet toilet paper in Application Example 1 and Application Example 6 respectively. Observe the color development time, the color that appears, and the fading time. The results are shown in Table 2.

[0161] Table 2

[0162]

[0163] As shown in Table 2, the wet toilet paper prepared by this invention has good pH responsiveness and fast color development time. After being coated with cyclodextrin, there is no significant difference in color development time, but the fading time is significantly prolonged, showing good stability.

[0164] Experimental Example 3: Stimulation Evaluation

[0165] Preparation of the test sample: The extruded liquid of the color-developing spunlace nonwoven fabric (wet-dry ratio 1:2) was impregnated with the prepared solution.

[0166] Grouping:

[0167] a. Without anthocyanins, when preparing colored spunlace nonwoven fabric, cyclodextrin is directly used to encapsulate lactic acid, and the other conditions are the same as in application example 1;

[0168] b. Without lactic acid, when preparing colored spunlace nonwoven fabric, cyclodextrin is directly used to encapsulate anthocyanins, and the other conditions are the same as in application example 1;

[0169] c. Without cyclodextrin, when preparing color-developing spunlace nonwoven fabric, ALA in the pH color developer was not encapsulated with cyclodextrin, and the other conditions were the same as in Application Example 1;

[0170] d. Without a soothing system, when preparing the solution, replace the soothing component with an equal amount of water, and keep the other conditions the same as in Application Example 1;

[0171] e. The complete formula, i.e., the same as in Application Example 1.

[0172] Test Methods: The irritation of the above samples was tested according to the following method: Referencing the "Chicken Embryo Viral Allantoic Membrane Test for Eye Irritation / Corrosivity of Cosmetics" (SN / T2329-2009), the reaction time method was used. Nine-day-old SPF-grade chicken embryos were candled, and the eggshell at the top of the air cell was removed to expose the allantoic membrane (CAM). 0.3 mL of the test sample was directly added to the CAM surface, and the time for the onset of bleeding, vascular lysis, and coagulation within 5 minutes was observed and recorded. Six parallel experiments were conducted for each test sample. A negative control (0.9% sodium chloride injection) and a positive control (0.1 mol / L sodium hydroxide solution) were also established. The irritation score was calculated using the formula: IS = (301-sec H) × 5 / 300 + (301-sec L) × 7 / 300 + (301-sec C) × 9 / 300. In the formula: sec H is the average time to the onset of bleeding observed on the CAM membrane, in seconds (s); sec L is the average time to the onset of vascular dissolution observed on the CAM membrane, in seconds (s); sec C is the average time to the onset of coagulation observed on the CAM membrane, in seconds (s). Irritation classification: IS < 1, no irritation; 1 ≤ IS < 5, mild irritation; 5 ≤ IS < 9, moderate irritation; IS ≥ 9, strong irritation.

[0173] The test results are shown in Table 3.

[0174] Table 3

[0175]

[0176] The data in Table 3 show that lactic acid is highly irritating, cyclodextrin has no obvious irritant effect, and anthocyanins have a de-irritant effect on the system, synergistically soothing the anti-inflammatory and de-irritant effects of the system.

[0177] Although the present invention has been illustrated and described with specific embodiments, it should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; those skilled in the art should understand that modifications can be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein, without departing from the spirit and scope of the present invention; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention; therefore, this means that all such substitutions and modifications that fall within the scope of the present invention are included in the appended claims.

Claims

1. A pH colorimetric reagent, characterized in that, The complex comprising anthocyanins and lactic acid is denoted as ALA; the raw materials of the pH colorimetric reagent include anthocyanins and lactic acid, wherein the mass ratio of anthocyanins to lactic acid is 1-2.7:1-3.

3.

2. The pH colorimetric reagent according to claim 1, characterized in that, At least a portion of the surface of the ALA is coated with cyclodextrin.

3. The method for preparing the pH colorimetric reagent according to claim 1 or 2, characterized in that, Includes the following steps: S1. Mix the anthocyanin solution and lactic acid solution, and stir the mixture under light-protected conditions; S2. After the reaction is complete, remove the uncomplexed lactic acid to obtain an ALA solution.

4. The method for preparing the pH colorimetric reagent according to claim 3, characterized in that, Step S2 is followed by the following steps: S3. Mix the cyclodextrin solution and the ALA solution, and then perform ultrasonic treatment and rotary mixing in sequence under light-protected conditions. Finally, freeze-dry to obtain cyclodextrin-encapsulated ALA, denoted as CD@ALA.

5. The method for preparing the pH colorimetric reagent according to claim 4, characterized in that, It meets at least one of the following characteristics: (1) In step S1, the mass ratio of anthocyanin to lactic acid is 1-2.7:1-3.3; (2) In step S1, the stirring speed is 200-400 rpm and the stirring time is 20-40 min; (3) In step S1, the anthocyanins are extracted from fresh cranberries using ethanol as the extraction solvent; (4) In step S2, uncomplexed lactic acid is removed by dialysis using a dialysis bag; (5) In step S3, the mass ratio of the cyclodextrin to the ALA is 1:1-1:3; (6) In step S3, the ultrasonic treatment time is 8-15 min and the ultrasonic treatment power is 40-60 W; (7) In step S3, the rotation speed of the rotary mixing is 40-50 r / min, and the rotation mixing time is 12-15 h.

6. A type of wet toilet paper, characterized in that, Includes a carrier and a pH colorimetric agent loaded on the carrier; The pH colorimetric agent is the pH colorimetric agent according to claim 1 or 2, or the pH colorimetric agent prepared by the preparation method according to any one of claims 3-5.

7. The nursing wet toilet paper according to claim 6, characterized in that, It also includes the solution loaded on the carrier; The prepared solution comprises, by weight percentage, 0.5%-1.3% soothing ingredients, 0.75%-1.5% preservative ingredients, 0.5%-2% moisturizing ingredients, 0.005%-0.01% pH adjuster, 0.1%-0.2% solubilizer, and the balance being water.

8. The nursing wet toilet paper according to claim 7, characterized in that, It meets at least one of the following characteristics: (1) The soothing ingredients include 0.1%-0.2% bisabolol, 0.2%-0.5% purslane extract, 0.1%-0.3% dipotassium glycyrrhizate, and 0.1%-0.3% oat β-glucan, based on their mass percentage in the prepared solution. (2) The preservative components, by mass percentage in the prepared solution, include 0.5%-1% of 1,2-hexanediol, 0.1%-0.3% of octyl glycol and 0.15%-0.2% of phenoxyethanol; (3) The moisturizing ingredients include at least one of sorbitol, propylene glycol, and butylene glycol; (4) The pH adjuster includes citric acid; (5) The solubilizer includes CO40; (6) The pH of the prepared solution is 5.5-6.

5.

9. The nursing wet toilet paper according to claim 8, characterized in that, The preparation method of the solution includes the following steps: Heat the water to 40-50°C, add the CO40 and bisabolol, stir until completely dissolved, add the remaining components, and stir to mix; after cooling, adjust the pH to 5.5-6.5 using the pH adjuster.

10. The method for preparing the nursing wet toilet paper according to any one of claims 6-9, characterized in that, Includes the following steps: a. Soak the carrier in deionized water and then air dry it for later use; b. Disperse the pH colorimetric agent in water, add 2D resin, MgCl2 and JFC penetrant, and stir evenly to obtain an impregnation solution; immerse the carrier dried in step a into the impregnation solution, at 30-50℃, at a solid-liquid mass ratio of 1:25-35 for 1-2 hours, and then dry to obtain the colorimetric carrier, which should be stored away from light. c. Apply the solution to the chromogenic support to obtain the final product.

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