A fabric yellowing agent and a method of fabric yellowing

Abstract

The application discloses a fabric yellowing reagent and a fabric yellowing method, and relates to the technical field of daily chemical products. 5 The fabric yellowing reagent comprises 1-3% of histidine solution and a bacterial suspension with a bacterial concentration of 1*10 5 CFU / mL-9*10 The bacteria are a mixture of one or more of Staphylococcus epidermidis and Micrococcus luteus; the solvent of the histidine solution is normal saline containing 0.15-1% of trypsin peptone; and the solvent of the bacterial suspension is normal saline containing 0.1-0.2% of trypsin soybean peptone liquid culture medium. The fabric yellowing reagent can be used for simulating fabric yellowing, and has good operability, reproducibility and data reliability.

Description

Technical Field

[0001] This invention relates to the field of daily chemical product technology, and in particular to compositions for inhibiting yellowing of fabrics, agents for inhibiting yellowing of fabrics, and their applications. Background Technology

[0002] With economic development and improved living standards, consumer demand has shifted from basic needs to quality. The demand for laundry products has changed from simply "wanting clothes to be clean" to "keeping them clean and new, and preventing them from yellowing even after prolonged storage." This demand is gradually becoming a focus for consumers, driving innovation in laundry products.

[0003] There are four main reasons why fabrics turn yellow: 1. Fiber degradation: Fiber degradation is caused by factors such as light, heat, radiation, chemicals, and biodegradation. 2. Additives: The addition of softeners, oils, optical brighteners, and other compounds can cause fabrics to yellow and discolor. 3. Air pollution: Nitrogen oxides, sulfur dioxide, and ozone can also cause fabrics to yellow. 4. Consumer contamination: Residues from sweat, perfumes, lotions, antiperspirants, and household detergents. Reason four is the primary cause of yellowing in collars, armpits, and backs.

[0004] In daily life, certain detergents (bleach) are commonly used to remove yellow stains from fabrics. However, these stains cannot be effectively removed by bleaching alone, as it may cause color bleeding or reddening of the fabric, resulting in irreversible damage. Furthermore, most commercially available stain removers are chlorine-based bleachs, and oxygen bleach requires soaking in hot water, both of which can damage the fabric. Meanwhile, safety and environmental friendliness are also key concerns for consumers. However, the industry currently lacks a good solution to effectively prevent yellowing of fabrics.

[0005] To study the yellowing of fabrics, establishing reliable and stable testing methods is crucial. One approach is the human method, which involves collecting samples from white clothing worn by volunteers. However, this method is time-consuming and requires a large number of volunteers. Another approach is to analyze the composition of sweat collected from volunteers to identify the substances causing yellowing. The advantage of this method is that it most closely resembles real-world conditions; however, it suffers from significant individual variability, high experimental costs, long experimental periods, and difficulty in ensuring the accuracy of the data. A second approach is the simulation method, which uses microorganisms and specific substances to induce yellowing on the fabric surface. This method offers advantages such as good stability, high uniformity, high repeatability, and low time cost; however, it differs somewhat from real-world conditions.

[0006] Sun Yunsong used artificial sweat to infect tussah silk and found that the inorganic salts in the artificial sweat (composed of L-histidine hydrochloride-hydrate, sodium chloride, and disodium hydrogen phosphate dodecahydrate) and the acid and alkalinity of the solution had a certain effect on yellowing (Sun Yunsong, Wu Huizhen. Study on yellowing of tussah silk soaked in artificial sweat under light [J]. Journal of Textile Research, 1988(06):19-22.). KWada treated fabric with artificial sweat and sweat components (composed of potassium sulfate, urea, ammonia, uric acid, creatine anhydride, arginine hydrochloride, glucose, and lactic acid). After being placed or exposed to light for a period of time, yellowing occurred. For cotton fabrics, urea and lactic acid had a greater impact (KWada. Studies on the Changes in Quality of Textile due to the Sweat (Part 3) [J]. Journal of Home Economics of Japan, 2010, 13.). Studies by Xie Renzhang et al. have found that the yellowing of silk is related to the types of amino acids in silk; tryptophan, tyrosine, and their yellowing products can all promote the light fading of dyes (Xie Renzhang, Shao Jianzhong, Zheng Xuming. The Influence of Amino Acids and Their Yellowing Products on the Light Fading of Dyes [J]. Journal of China Textile University, 1993, 19(1):8.). The above studies all indicate that certain components in sweat can cause fabric yellowing, but the specific reasons for the yellowing of fabrics are not clear, and the above studies are all from a chemical perspective, without considering the influence of microorganisms on the yellowing of fabrics caused by sweat. Winder L confirmed through experiments that wool yellowing is related to the combined action of bacteria and high humidity, but did not mention the types of microorganisms, or the role of microorganisms in wool yellowing (Winder L, Baronian K, Webber J, et al. Unravelling the causes of wool yellowing: Part II Involvement of bacteria [J]. 1998.).

[0007] Therefore, there is an urgent need to develop a method for simulating fabric yellowing that is highly operable, reproducible, and provides reliable data. Simultaneously, there is a need to develop an inhibitor to suppress fabric yellowing caused by microorganisms and sweat components. Furthermore, this inhibitor should also possess long-lasting antibacterial effects, endowing the fabric with the ability to resist microbial growth and reproduction. Summary of the Invention

[0008] The purpose of this invention is to provide a method for inducing yellowing of fabrics using the combined action of microorganisms and histidine. This method is characterized by high repeatability, stable results, and good operability.

[0009] Another object of the present invention is to provide a composition for inhibiting yellowing of fabrics, which can inhibit yellowing caused by the combined action of microorganisms and histidine, and can give the fabric a long-lasting antibacterial rate of greater than or equal to 90%.

[0010] The technical solution of the present invention is as follows.

[0011] This invention provides a composition for inhibiting yellowing of fabrics, comprising the following components by weight percentage:

[0012] Component A, 0.3% to 1.5%;

[0013] Component B, 0.2% to 1%;

[0014] Nonionic surfactant, 0.15% to 1%;

[0015] Cyclodextrin, 0.2% to 1.5%;

[0016] Salts of organic acids, 0.1% to 1%;

[0017] Menthol, 0.01% to 0.2%;

[0018] The remainder is water;

[0019] Component A is selected from one or more of the following substances in a composition: methylglycine diacetate, diethylenetriaminepentaacetate, cyclohexanediaminetetraacetate, ethylene glycol diethyl ether diaminetetraacetate, triethylenetetraaminehexaacetate, hydroxyethylidene diphosphonate, ethylenediaminetetramethylidene phosphonate, ethylenediamine-N,N'-disuccinate; the cation portion of the salt is one or more of sodium ions, potassium ions, and ammonium ions;

[0020] Component B is selected from a composition consisting of one or more of the following substances: C8-C18 hydrocarbon dimethyl benzyl ammonium salt, C8-C18 hydrocarbon trimethyl ammonium salt, C8-C18 hydrocarbon pyridinium chloride, C8-C18 hydrocarbon pyridinium bromide, C8-C18 hydrocarbon ethyl morpholine ethyl sulfate salt, C8-C18 hydrocarbon ethyl morpholine methyl sulfate salt, chlorhexidine acetate, chlorhexidine gluconate, dicedyl dimethyl ammonium salt, polyhydroxypropyl dimethyl ammonium salt, polyhexamethylene biguanide hydrochloride, and polyhexamethylene monoguanide hydrochloride; the hydrocarbon group refers to a chain or ring structure composed of carbon atoms and hydrogen atoms, and the number of double bonds is selected from 0, 1, 2, 3, and 4; the anionic portion of the ammonium salt is selected from at least one chloride ion or bromide ion.

[0021] The nonionic surfactant is selected from at least one of C10-C22 alkyldimethylamine oxide and C10-C22 alkylamidopropylamine oxide.

[0022] The organic acid portion of the salt is selected from benzoic acid, sorbic acid, and dehydroacetic acid; the cation portion of the salt is sodium ion, potassium ion, or ammonium ion.

[0023] The cyclodextrin is selected from one or more of α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, hydroxypropyl-β-cyclodextrin, hydroxyethyl-β-cyclodextrin, and methyl-β-cyclodextrin.

[0024] Furthermore, the composition for inhibiting fabric yellowing may also contain at least one of a pH adjuster, a chelating agent, a surfactant, a fragrance, and a pigment.

[0025] Furthermore, the composition for inhibiting fabric yellowing also contains 20% to 40% ethanol.

[0026] The above-mentioned composition for inhibiting fabric yellowing can be used to inhibit fabric yellowing caused by the combined action of microorganisms and histidine.

[0027] The present invention also provides a fabric yellowing reagent, comprising a histidine solution of 1% to 3% by mass and a bacterial concentration of 1*10⁻⁶. 5 CFU / mL up to 9*10 5 A bacterial suspension of CFU / mL; the bacteria refer to one or more of Staphylococcus epidermidis and Micrococcus luteus.

[0028] The solvent for the histidine solution is physiological saline containing 0.15% to 1% tryptone by mass.

[0029] The solvent for the bacterial suspension is physiological saline containing 0.1% to 0.2% tryptic soy broth by weight. Preferably, the solvent for the bacterial suspension is physiological saline containing 0.15% tryptic soy broth by weight.

[0030] The present invention provides a method for yellowing fabrics, comprising the following steps: adding the above-mentioned fabric yellowing reagent to the fabric and co-culturing it for 3 to 4 days in an environment of (36±5℃) and (85±5)% relative humidity.

[0031] The above-described composition for inhibiting fabric yellowing can be used to inhibit fabric yellowing caused by the aforementioned fabric yellowing reagent.

[0032] The above-mentioned composition for inhibiting fabric yellowing and the method for inhibiting fabric yellowing include the following steps: surface treatment of the fabric with the composition for inhibiting fabric yellowing.

[0033] This invention also provides a test method for inhibiting the yellowing of fabrics, comprising the following steps:

[0034] The fabrics were degreased and then divided into test and control groups.

[0035] The fabrics of the test group were surface-treated with the composition for inhibiting yellowing of fabrics; the fabrics of the control group were surface-treated with pure water.

[0036] The fabric yellowing reagent was dropped onto the surface-treated test group fabric and control group fabric respectively, and then placed in an environment of (36±5℃) and (85±5)% relative humidity for 3 to 4 days.

[0037] After sterilization, using the degreased fabric without other treatment as the standard sample, the color difference value dE1 of the test group fabric and the color difference value dE2 of the control group fabric were measured using a colorimeter; the color difference value was taken as the db* value as the test result.

[0038] Judgment of the effect of inhibiting fabric yellowing: Calculate the difference ΔE between the color difference values ​​of the test group fabric and the control group fabric according to the following formula (1);

[0039] △E=dE2-dE1 Equation (1);

[0040] △E: Difference between the test group and the control group;

[0041] dE1: Color difference value of the test group;

[0042] dE2: Color difference value of the control group;

[0043] When dE2 is greater than or equal to 25.0 and ΔE is greater than or equal to 20.0, it is determined that it has the effect of inhibiting yellowing of fabrics.

[0044] The preferred test method for inhibiting fabric yellowing specifically employs the following steps:

[0045] Step (1): Cut the fabric sample into fabric pieces of the preset size, degrease, sterilize under high pressure and dry, pretreat the fabric with 0.2g of sample (composition to inhibit yellowing of fabric), and use 0.2g of pure water as a negative control; each test group includes a control group and a test group. The control group corresponds to the fabric piece pretreated with pure water, and the test group contains at least one test subgroup. One test subgroup corresponds to a fabric piece treated with one sample; each test group has at least 3 replicates;

[0046] Step (2): Place the test cloth patch into the corresponding sterile petri dish, add 0.5 mL of 1% to 3% histidine solution, and add 0.5 mL of 1 to 9*10 5 Prepare a bacterial suspension of CFU / mL, cover the culture dish, and incubate at 36℃ and 85% relative humidity for 3 to 4 days.

[0047] Step (3): Irradiate the test cloth in a UV lamp box for 30 minutes, and place it in a 50℃ oven for 2 hours for later use;

[0048] Step (4): Use a colorimeter to measure the color difference value of the fabric after cultivation, and use the fabric piece that has not been treated after degreasing as the standard sample; when the relative standard deviation between the three parallel test results is less than 15%, take the mathematical average value as dE value, and keep one decimal place.

[0049] Step (5): Calculate the color difference between the test group and the control group according to formula (1). When △E is greater than or equal to 20.0 and dE2 is greater than or equal to 25.0, the composition is determined to have the effect of inhibiting yellowing of fabrics.

[0050] The technical solution described in this invention has the following beneficial effects:

[0051] (1) The fabric yellowing reagent of the present invention can be used to simulate fabric yellowing, and has good operability, reproducibility and data reliability.

[0052] (2) The composition provided for inhibiting fabric yellowing can effectively inhibit the yellowing of fabrics caused by microorganisms and histidine in sweat, and maintain the original color of the fabric.

[0053] (3) The provided method for yellowing fabrics uses microorganisms and histidine to produce yellowing on the surface of the fabric. The steps are simple, easy to operate, and have good reproducibility.

[0054] (4) The provided composition for inhibiting yellowing of fabrics imparts to the treated fabric a long-lasting antibacterial effect against Staphylococcus epidermidis and Staphylococcus aureus, with a long-lasting antibacterial rate of ≥90%.

[0055] (5) This combination for inhibiting fabric yellowing does not require the use of substances such as sodium hypochlorite, chlorine dioxide, hydrogen peroxide, and sodium percarbonate, and does not require heating treatment, which can effectively reduce damage to the fabric. Attached Figure Description

[0056] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0057] Figure 1 This is an image of the fabric after yellowing treatment according to Embodiment 1 of the present invention.

[0058] Figure 2 This is a picture of the fabric treated by the yellowing method in Comparative Example 1 of the present invention.

[0059] Figure 3 The image shows a fabric treated with the method for inhibiting yellowing of fabrics in Example 1 of the present invention.

[0060] Figure 4 The image shows a fabric treated by the method for inhibiting yellowing of fabrics in Comparative Example 1 of the present invention. Detailed Implementation

[0061] To better understand the technical content of the present invention, the technical solution of the present invention will be further introduced and explained below in conjunction with specific embodiments.

[0062] Unless otherwise specified, all percentages, fractions, and ratios are calculated based on the total mass of the compositions of the present invention. Unless otherwise specified, all mass contents of the listed ingredients refer to the mass contents of the active substance and therefore do not include solvents or byproducts that may be present in commercially available materials. The terms "percentage by mass" and "mass content" are not distinguished herein and are expressed by the symbol "%".

[0063] Unless otherwise specified, all molecular weights in this document are weight-average molecular weights expressed in Daltons.

[0064] Unless otherwise specified, all preparations and tests described herein took place at 25°C.

[0065] The terms “comprising,” “including,” “containing,” “having,” “comprising,” or other variations thereof are intended to cover non-closed inclusion, and no distinction is made between these terms. The term “comprising” means that other steps and ingredients may be added without affecting the final result. The term “comprising” also includes the terms “consisting of” and “substantially composed of.” The compositions and methods / processes of the present invention comprise, consist of, and substantially consist of the essential elements and limitations described herein, as well as any additional or optional ingredients, components, steps, or limitations described herein. No distinction is made between the terms “efficacy,” “performance,” “effect,” and “potency” herein.

[0066] The technical solution of this invention does not contain sodium hypochlorite, chlorine dioxide, hydrogen peroxide, sodium percarbonate, or other substances. The term "does not contain" means that the technical solution of this invention does not intentionally add the above-mentioned substances, and the content of the above-mentioned substances in the composition involved is less than 0.1%.

[0067] In this invention, the terms "anti-yellowing efficacy of fabric after sample treatment" and "anti-yellowing efficacy of the sample fabric" are not distinguished. Regardless of the expression, both refer to the fact that the fabric treated with the sample is less prone to yellowing after undergoing histidine and bacterial action. When conducting the anti-yellowing test, the test object is the fabric after sample treatment.

[0068] The purpose of this invention is to suppress the degree of yellowing of fabrics under specific conditions and maintain the original color of the fabric; rather than to restore the original color of fabrics that have already yellowed. This invention uses white fabrics as the research object.

[0069] Fabric yellowing

[0070] The term "fabric yellowing" in this invention refers to the yellowing phenomenon on fabrics caused by microbial and histidine contamination.

[0071] Fabric yellowing reagent

[0072] The fabric yellowing reagent of the present invention comprises 1% to 3% by mass of histidine solution and bacteria at a concentration of 1*10. 5 CFU / mL up to 9*10 5 A bacterial suspension at CFU / mL; the bacteria refer to one or more of Staphylococcus epidermidis and Micrococcus luteus. Preferably, the fabric yellowing reagent comprises an equal volume of histidine solution and the bacterial suspension.

[0073] Methods for preventing fabric yellowing

[0074] The terms "fabric yellowing method" and "fabric yellowing simulation method" in this invention are not distinguished. Specifically, it refers to a method that induces yellowing on the fabric surface through the action of bacteria and histidine. The steps are as follows:

[0075] Step (1): Surface treatment of the fabric using a control sample. Cut the fabric sample into pieces of the predetermined size, degrease them, and set them aside. Treat the fabric surface with 0.2g of pure water; this is called the control sample. At least three parallel control samples should be prepared.

[0076] Step (2): Co-culturing. Place the above-mentioned cloth pieces into the corresponding sterile culture dishes, add 0.5 mL of 1% to 3% histidine solution, and add 0.5 mL of 1 to 9*10... 5 CFU / mL bacterial suspension, cover the culture dish, and incubate at 36℃ and 85% relative humidity for 3 to 4 days;

[0077] Step (3): Irradiation sterilization. Irradiate the test cloth in a UV lamp box for 30 minutes, then place it in a 50℃ oven for 2 hours for later use;

[0078] Step (4): Color difference test. Use a colorimeter to measure the color difference value of the cultured fabric, using the degreased fabric without any other treatment as the standard sample. Take the db* value as the test result.

[0079] Step (5): Calculation of color difference value. When the relative standard deviation between the three parallel test results is less than 15%, the mathematical average of the test results is taken as the color difference value of the control sample, expressed as dE2, and the result is rounded to one decimal place;

[0080] Step (6): Determine the validity of the experiment. When dE2 is greater than or equal to 25.0, the experimental result is deemed valid. Otherwise, repeat steps (1) to (6) until the experimental result is deemed valid.

[0081] When the experimental results were deemed effective, the fabric underwent effective yellowing.

[0082] Degreasing treatment

[0083] Degreasing treatment involves weighing approximately 30g of fabric and adding it to 300mL of degreasing solution (fabric-to-solution ratio 1:10), then boiling for 1 hour. The fabric is then removed and rinsed in 1L of boiled distilled water for 5 minutes. Next, the fabric is rinsed in 1L of room-temperature distilled water for 5 minutes to remove any residual pretreatment solution. Finally, the fabric is allowed to air dry naturally for later use.

[0084] The degreasing solution is a pure aqueous solution of 0.00025% fatty alcohol polyoxyethylene ether (9) and 0.5% sodium carbonate.

[0085] Fabric sample

[0086] The term "fabric sample" refers to cotton fabric conforming to GB / T 7568.2-2008 or polyester fabric conforming to GB / T 7568.4-2008. The term "preset size" refers to each fabric piece being a small square piece with a side length of 43mm.

[0087] Surface treatment

[0088] The term "surface treatment" refers to the uniform application or spraying of an anti-yellowing composition, pure water, or other sample onto a fabric sheet of a predetermined size. The treated fabric sheet is completely covered by the sample, with no obvious water stains or water droplets.

[0089] 1% to 3% histidine solution

[0090] The solvent for a 1% to 3% histidine solution is physiological saline containing 0.15% to 1% tryptone by mass. Physiological saline refers to a pure aqueous solution of 0.85% sodium chloride.

[0091] bacterial suspension

[0092] The bacteria in the bacterial suspension are one or more of Staphylococcus epidermidis and Micrococcus luteus, and the solvent is physiological saline containing 0.15% tryptic soy peptone broth. The bacterial concentration is 1 to 9 x 10⁻⁶. 5 CFU / mL. Physiological saline refers to a pure aqueous solution of 0.85% sodium chloride.

[0093] Colorimeter

[0094] A colorimeter is an optical measuring instrument that simulates the human eye's perception of red, green, and blue light. It primarily measures and displays the color difference between a sample and the test sample based on the Lab, Lch principle of the CIE color space. A degreased fabric sample without other treatment is used as the standard sample, and the db* value is taken as the test result. The db* value is dimensionless. If the sample is more yellow than the standard sample, the db* value is positive; if the control sample is more blue than the standard sample, the db* value is negative. The colorimeter used in this invention is the Konica Minolta SM6300A colorimeter from Japan.

[0095] Effective yellowing

[0096] The term "effective yellowing" in this invention refers to a fabric whose dE2 is greater than or equal to 25.0 after being treated with specific steps.

[0097] Methods to inhibit fabric yellowing

[0098] The term "method for inhibiting yellowing of fabrics" in this invention specifically refers to a method for inhibiting yellowing of fabric surfaces caused by bacteria and histidine using a specific composition. The steps are as follows:

[0099] Step (1): Surface treatment of the fabric sample. Cut the fabric sample into fabric pieces of the preset size, degrease and set aside. Use 0.2g of sample to treat the surface of the fabric, and use 0.2g of pure water as a negative control. Each test group includes a control group and a test group. The control group corresponds to the fabric piece pretreated with pure water. The test group contains at least one test subgroup. One test subgroup corresponds to a fabric piece treated with one sample. Each test group has at least 3 replicates.

[0100] Step (2): Co-culture. Place the above cloth pieces into the corresponding sterile culture dishes, add 0.5 mL of 1% to 3% histidine solution, add 0.5 mL of bacterial suspension of 1 to 9*10^5 CFU / mL, cover the culture dishes, and co-culture at 36℃ and 85% relative humidity for 3 to 4 days;

[0101] Step (3): Irradiation sterilization. Irradiate the test cloth in a UV lamp box for 30 minutes, then place it in a 50℃ oven for 2 hours for later use;

[0102] Step (4): Color difference test. Use a colorimeter to measure the color difference of the cultured fabric, using the degreased fabric without any other treatment as the standard sample. Take the db* value as the test result.

[0103] Step (5): Calculation of color difference value. When the relative standard deviation between the three parallel test results is less than 15%, the mathematical average of the test results is taken as the color difference value, where dE1 is the color difference value of the test group and dE2 is the color difference value of the control group. The result is rounded to one decimal place.

[0104] Step (6): Determine the validity of the experiment. When dE2 is greater than or equal to 25.0, the experimental result is deemed valid. Otherwise, repeat steps (1) to (6) until the experimental result is deemed valid.

[0105] Step (7): Determine the efficacy of the composition in inhibiting fabric yellowing. Calculate the color difference between the test group and the control group according to formula (1). If ΔE is greater than or equal to 20.0, the composition is determined to have the efficacy in inhibiting fabric yellowing.

[0106] △E=dE2-dE1 Equation (1)

[0107] △E: Difference between the test group and the control group;

[0108] dE1: Color difference value of the test group;

[0109] dE2: Color difference value of the control group.

[0110] The terms “degreasing treatment”, “cloth sample”, “surface treatment”, “1% to 3% histidine solution”, “bacterial suspension”, and “colorimeter” are explained above and will not be repeated here.

[0111] Composition to inhibit fabric yellowing

[0112] This invention provides a composition for inhibiting yellowing of fabrics. The terms "composition for inhibiting yellowing of fabrics" and "composition for inhibiting yellowing" are not used interchangeably.

[0113] The fabric yellowing inhibition composition provided by the present invention comprises the following substances by weight percentage:

[0114] (1) Component A, 0.3% to 1.5%;

[0115] (2) Component B, 0.2% to 1%;

[0116] (3) Nonionic surfactant, 0.15% to 1%;

[0117] (4) Cyclodextrin, 0.2% to 1.5%;

[0118] (5) Salts of organic acids, 0.1% to 1%;

[0119] (6) Menthol, 0.01% to 0.2%;

[0120] (7) The remainder is water.

[0121] Component A

[0122] Component A is a composition selected from one or more of the following substances: methylglycine diacetate, diethylenetriaminepentaacetate, cyclohexanediaminetetraacetate, ethylene glycol diethyl ether diaminetetraacetate, triethylenetetraaminehexaacetate, hydroxyethylidene diphosphonate, ethylenediaminetetramethylidene phosphonate, and ethylenediamine-N,N'-disuccinate. The cation portion of the salt contained in Component A is one or more of sodium ions, potassium ions, and ammonium ions.

[0123] In some specific implementation examples, component A is the sodium salt of diethylenetriaminepentaacetic acid, or the sodium salt of hydroxyethylidene diphosphonic acid, or citric acid.

[0124] Component B

[0125] Component B is a composition selected from one or more of the following substances: C8-C18 hydrocarbon dimethylbenzylammonium salt, C8-C18 hydrocarbon trimethylammonium salt, C8-C18 hydrocarbon pyridinium chloride, C8-C18 hydrocarbon pyridinium bromide, C8-C18 hydrocarbon ethylmorpholine ethyl sulfate, C8-C18 hydrocarbon ethylmorpholine methyl sulfate, chlorhexidine acetate, chlorhexidine gluconate, disacyldimethylammonium salt, polyhydroxypropyl dimethylammonium salt, polyhexamethylene biguanide hydrochloride, and polyhexamethylene monoguanide hydrochloride. The hydrocarbon group involved in Component B refers to a chain or cyclic structure composed of carbon and hydrogen atoms, and the number of double bonds is selected from 0, 1, 2, 3, and 4. The anionic portion of the ammonium salt involved is selected from at least one chloride ion and a bromide ion.

[0126] In some specific implementation examples, component B is dodecyl dimethyl ammonium chloride, or polyhexamethylene biguanide hydrochloride, or sodium soy alkyl ethylmorpholine ethyl sulfate.

[0127] Nonionic surfactants

[0128] The nonionic surfactant is selected from C10-C22 alkyldimethylamine oxide and C10-C22 alkylamidopropylamine oxide. In some specific embodiments, the component nonionic surfactant is dodecyldimethylamine oxide.

[0129] Cyclodextrin

[0130] The cyclodextrin is selected from one or more of α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, hydroxypropyl-β-cyclodextrin, hydroxyethyl-β-cyclodextrin, and methyl-β-cyclodextrin. In some specific embodiments, the cyclodextrin component is β-cyclodextrin.

[0131] Salts of organic acids

[0132] The organic acid portion of the salt is selected from benzoic acid, sorbic acid, and dehydroacetic acid; the cation portion is a mixture of one or more sodium ions, potassium ions, and ammonium ions.

[0133] The composition for inhibiting fabric yellowing also includes a pH adjuster, a chelating agent, and the above-mentioned... nonionic At least one of the following: surfactants other than surfactants, fragrances, and pigments. The composition for inhibiting fabric yellowing may also contain 20% to 40% ethanol.

[0134] Long-lasting antibacterial efficacy

[0135] Long-lasting antibacterial efficacy refers to the significant reduction in bacterial count compared to the control sample after a 2-day co-culture period between the fabric treated with the technical solution of this invention. When expressed numerically, long-lasting antibacterial efficacy means that the long-lasting antibacterial rate after a 2-day co-culture period between the fabric treated with the technical solution of this invention is ≥90%.

[0136] In this invention, the terms "long-lasting antibacterial efficacy of the fabric after sample treatment" and "long-lasting antibacterial efficacy of the sample" are not distinguished. Regardless of the expression, in the long-lasting antibacterial test, it is the fabric that exerts the inhibitory and killing effect on bacteria. The reason why the fabric has long-lasting antibacterial efficacy is due to undergoing specific sample treatment.

[0137] Long-lasting antibacterial test method

[0138] The term "long-lasting antibacterial test method" in this invention specifically includes the following test steps.

[0139] 1. Preparation of the test bacterial suspension: Take freshly cultured Staphylococcus aureus or Staphylococcus epidermidis slant agar, and pipette 5.0 mL of the bacterial suspension preparation solution into the slant tube. Repeatedly pipette the solution to wash away the bacterial growth. Then, transfer all the washings to another sterile test tube and mix with an electric mixer for 20 seconds, or tap the tube 80 times on the palm of your hand to ensure the bacterial suspension is homogeneous. The initial bacterial suspension should be prepared with a concentration of 1 × 10⁻⁶. 5 CFU / mL up to 3×10 5 CFU / mL.

[0140] 2. Fabric preparation: Cut the fabric sample into fabric pieces of the predetermined size, degrease, autoclave, and then dry. Use 0.2g of sample to treat the surface of one fabric piece, and use 0.2g of pure water as a negative control.

[0141] The fabric sample refers to cotton fabric conforming to GB / T 7568.2-2008, or polyester fabric conforming to GB / T 7568.4-2008. The "preset size" refers to each fabric piece being a small square piece with a side length of 43mm.

[0142] Degreasing treatment involves weighing approximately 30g of fabric and adding it to 300mL of degreasing solution (fabric-to-solution ratio 1:10), then boiling for 1 hour. The fabric is then removed and rinsed in 1L of boiled distilled water for 5 minutes. The fabric is then rinsed again in 1L of room-temperature distilled water for 5 minutes to remove any residual pretreatment solution. Finally, the fabric is allowed to air dry naturally for later use. The degreasing solution is a pure aqueous solution of 0.00025% fatty alcohol polyoxyethylene ether (9) and 0.5% sodium carbonate.

[0143] Surface treatment refers to the uniform application or spraying of an anti-yellowing composition, pure water, or other samples onto a fabric sheet of a predetermined size. The treated fabric sheet is completely covered by the sample, with no obvious water stains or water droplets.

[0144] 3. Sample inoculation: For each test group, take two cloth samples of the same sample and two control samples, and stack them in two empty sterile petri dishes. Add 0.2 mL of the above bacterial suspension, ensuring the bacterial suspension is spread as evenly as possible on the sample. Each test group contains two parallel test subgroups. Each test subgroup includes one set of cloth samples treated with the detergent composition (hereinafter referred to as test samples) and one set of cloth samples treated with the control (hereinafter referred to as control samples), which are used for immediate elution and testing after inoculation and for elution and testing after further incubation, respectively.

[0145] 4. Washing immediately after inoculation: Use sterile tweezers to pick up one group of test samples and one group of control samples that have just been inoculated with bacteria, and put them into two homogenization bags containing 10g of sterile bacterial eluent. Homogenize them in a homogenizer for 1 minute to wash the bacteria off the samples.

[0146] 5. Continued Incubation and Elution of Inoculated Fabric Patches: Cover two sterile petri dishes containing the inoculated bacterial suspension (one containing the inoculated test sample and the other containing the inoculated control sample) with their lids and seal with plastic wrap to prevent evaporation of the liquid on the carrier. Incubate at 36℃ for 1 to 3 days, maintaining a relative humidity above 85%. After the incubation period, place each test sample and control sample into a homogenizing bag containing 10g of sterile bacterial eluent and homogenize in a homogenizer for 1 minute to elute the bacteria from the samples.

[0147] 6. Determination of viable bacterial count: Transfer 1 mL of eluent (from steps 4 and 5 above) into a test tube containing 9 mL of phosphate-buffered saline (PBS) and shake thoroughly. Transfer 1 mL of sample solution from this test tube into another test tube containing 9 mL of PBS and shake thoroughly. Repeat this process for 10-fold serial dilutions of the eluent from steps 4 and 5 above. Replace the pipette tip after each transfer.

[0148] Use a pipette to draw 1 mL of sample solution from each of the serially diluted test tubes and inject it into a Petri dish. Then pour in 15 mL to 20 mL of tryptone soy agar (TSA) medium at 45°C to 46°C, cover the dish, and let it solidify at room temperature. Then invert the Petri dish and incubate at 36°C for 48 hours. Count the number of colonies.

[0149] Steps 3 through 6 above should be tested in parallel at least 3 times.

[0150] 7. Evaluation of experimental validity: The average bacterial colony count of the control sample washed immediately after inoculation should be less than 1×10⁻⁶. 5 CFU / mL up to 9×10 5 CFU / mL, count the bacterial growth value F according to formula (2), and when F is greater than or equal to 1.5, the test is considered valid.

[0151] F = lgC t -lgC0………………………………………Equation (2)

[0152] F – Bacterial growth value of the control sample;

[0153] C t : The number of bacteria after the control sample was inoculated and cultured for a period of time;

[0154] C0: The number of bacteria measured immediately after inoculation of the control sample.

[0155] 8. Calculation of long-lasting antibacterial rate: The long-lasting antibacterial rate is calculated according to formula (3), and the result is rounded to two decimal places. When the relative standard deviation between three parallel test results is less than 15%, the mathematical average of the test results is taken as the long-lasting antibacterial rate of the sample. When the calculated value is negative, it is represented as "0.00". A long-lasting antibacterial rate ≥ 90.00% indicates that the fabric treated with the sample has a long-lasting antibacterial effect.

[0156]

[0157] C t The number of bacteria measured after the control sample has been inoculated and cultured for a period of time;

[0158] T t The number of bacteria measured after the test sample has been inoculated and cultured for a period of time.

[0159] The method of using the detergent composition of the present invention is well known to those skilled in the art. A typical method of use is to apply the composition, either undiluted or diluted, to the fabric surface, and then allow the fabric to dry. Contact methods include, but are not limited to, spraying, dipping, and dripping. The composition can cover the entire fabric surface or only a portion, such as the cuffs or collar of a shirt. A preferred dilution ratio is 5:1 to 1:1.

[0160] Without further detailed explanation, it is believed that those skilled in the art can fully utilize the present invention based on the above description. The following embodiments are intended to further illustrate and demonstrate specific implementations within the scope of the present invention. Therefore, the embodiments should be understood as being used only to illustrate the present invention in more detail, and not to limit the scope of the present invention in any way.

[0161] In the following examples, unless otherwise specified, all contents are percentages by mass, and the contents of the listed ingredients are converted contents of active substances.

[0162] Examples and comparative examples of methods for preventing fabric yellowing.

[0163] The fabric was treated with pure water according to the aforementioned method for treating fabric yellowing, and the color difference value dE2 of the fabric was tested. The similarities and differences between Examples 1 to 3 and Comparative Examples 1 to 12 are shown in Table 1. In Table 1, the solvent in the solutions involved in Examples 1 to 3 and Comparative Examples 1 to 12 refers to physiological saline containing 0.15% tryptone by mass. The solutions of oleic acid and squalene in Comparative Examples 3 and 4 are emulsions.

[0164] Table 1. Similarities and differences between Method Examples 1 to 3 and Method Comparative Examples 1 to 12

[0165]

[0166] Method Example 1: Fabric treated with the yellowing method, such as... Figure 1 As shown.

[0167] Method Comparison Example 1: Fabrics treated with the yellowing method, such as... Figure 2 As shown.

[0168] Table 2 shows the color difference values ​​(dE2) of Method Examples 1 to 3 and Method Comparative Examples 1 to 12, as well as the determination of experimental validity. It can be seen that the color difference values ​​(dE2) of Method Examples 1 to 3 using the technical solution of this invention are all greater than 25.0, and the experimental validity is determined to be effective. However, Method Comparative Examples 1 to 11, which used milk, urea, oleic acid, squalene, lysine, tryptophan, glycine, serine, cysteine, threonine, and tyrosine respectively to replace histidine in the technical solution of this invention, all had color difference values ​​(dE2) far less than 25.0, and the experimental validity was determined to be ineffective. Method Comparative Example 12 used 0.25 mL of 3% lysine solution + 0.25 mL of 1% histidine solution, and the color difference value (dE2) was greater than 25.0, and the experimental validity was determined to be effective. However, compared with Method Comparative Example 5, it can be seen that the 3% lysine solution did not promote the yellowing of the fabric; therefore, the yellowing of the fabric was due to the 0.25 mL 3% histidine solution. Thus, the combination of lysine and histidine has no synergistic effect. The technical solution of this invention, which uses 0.5 mL of 1% to 3% histidine solution, is superior to other comparative solutions.

[0169] Table 2 shows the color difference values ​​dE2 and experimental validity assessments for Method Examples 1 to 3 and Method Comparative Examples 1 to 12.

[0170] Technical solution <![CDATA[Color difference value dE2]]> Judgment of experimental validity Method Example 1 26.4 efficient Method Example 2 29.0 efficient Method Example 3 31.3 efficient Method Comparison Example 1 3.3 invalid Method Comparison Example 2 4.5 invalid Method Comparison Example 3 4.0 invalid Method Comparison Example 4 5.5 invalid Method Comparison Example 5 3.2 invalid Method Comparison Example 6 2.7 invalid Method Comparison Example 7 4.3 invalid Method Comparison Example 8 4.3 invalid Method Comparison Example 9 7.0 invalid Method Comparative Example 10 8.8 invalid Method Comparison Example 11 3.9 invalid Method Comparison Example 12 27.9 efficient

[0171] The similarities and differences between Method Example 1 and Method Comparative Examples 13 to 15 are shown in Table 3.

[0172] Table 3. Similarities and differences between Method Example 1 and Method Comparative Examples 13 to 15

[0173]

[0174] Table 4 shows the color difference values ​​dE2 for Method Example 1 and Comparative Examples 13 to 15, as well as the determination of experimental validity. It can be seen that in Method Example 1 using the technical solution of the present invention, regardless of whether the fabric is cotton or polyester, the color difference value dE2 is greater than 25.0, and the experimental validity is determined to be effective. In Comparative Example 13, when the histidine solution is in pure water, it cannot cause effective yellowing of cotton and polyester fabrics. In Comparative Example 14, when the histidine solution is in a pure aqueous solution of 0.15% tryptone, it can cause effective yellowing of cotton fabrics but not polyester fabrics. In Comparative Example 15, when the histidine solution is in physiological saline with 0.05% tryptone, it cannot cause effective yellowing of cotton and polyester fabrics. The technical solution of the present invention, using 0.5 mL of 1% to 3% histidine solution in physiological saline with 0.15% tryptone, is superior to other comparative methods.

[0175] Table 4. Color difference values ​​dE2 and experimental validity judgments for Method Example 1 and Method Comparative Examples 13 to 15.

[0176]

[0177] The similarities and differences between Method Example 1, Method Example 4, and Comparative Examples 16 to 19 are shown in Table 5. The solvent for the bacterial suspensions was physiological saline containing 0.15% tryptic soy broth.

[0178] Table 5. Similarities and differences between Method Examples 1, 4, and Comparative Examples 16 to 19

[0179]

[0180] Table 6 shows the color difference values ​​dE2 for Method Examples 1, 4, and Comparative Examples 16 to 19, as well as the determination of experimental validity. It can be seen that the color difference values ​​dE2 for Method Examples 1 and 4, which employ the technical solution of this invention, are both greater than 25.0. This indicates that *Staphylococcus epidermidis* and *Micrococcus luteus*, combined with histidine solution, can effectively induce yellowing in fabrics. Comparative Example 16, using only histidine solution without bacterial suspension, cannot induce effective yellowing in fabrics. Comparative Examples 17 and 18, using *Staphylococcus aureus* and *Escherichia coli* respectively, also fail to induce effective yellowing in fabrics. Comparative Example 19, in addition to using *Staphylococcus epidermidis* bacterial suspension and histidine solution, also adds sebum and oily stains. The sebum and oily stains meet the requirements of Appendix D of GB / T13174-2008 "Determination of Detergent Strength and Recycled Washing Performance of Detergents for Clothing". The particularly low dE2 value of Comparative Example 19 may be due to the competition between sebum and oily liquid and bacterial suspension / histidine solution for the fabric surface, resulting in a decrease in the occupancy of the bacterial suspension / histidine solution on the fabric surface.

[0181] Table 6. Color difference values ​​dE2 and experimental validity judgments for Method Example 1, Method Example 4, and Method Comparative Examples 16 to 19.

[0182]

[0183] Preparation methods of compositions for inhibiting yellowing of fabrics (examples and comparative examples)

[0184] In the following composition examples, the raw materials used and their component categories are described below:

[0185] Sodium salt of diethylenetriaminepentaacetic acid, component A;

[0186] Sodium salt of hydroxyethylidene diphosphonic acid, component A;

[0187] Sodium salt of ethylenediaminetetramethylenephosphonic acid, component A;

[0188] Dodecyl dimethyl ammonium chloride, component B;

[0189] Polyhydroxypropyl dimethylammonium chloride, component B;

[0190] Sodium ethylmorpholine ethyl sulfate of soybean, component B;

[0191] Polyhexamethylene biguanide hydrochloride, component B;

[0192] Dodecyl dimethylamine oxide, a nonionic surfactant;

[0193] Sodium benzoate, a salt of an organic acid;

[0194] β-Cyclodextrin, cyclodextrin;

[0195] Citric acid, a pH adjuster;

[0196] Sodium hydroxide, a pH adjuster.

[0197] The preparation method of the detergent composition of the present invention includes the following steps:

[0198] (1) Add soft water to the reactor, add component A and component B and stir evenly;

[0199] (2) Add nonionic surfactant, organic acid salt and cyclodextrin to the reaction vessel and continue stirring until homogeneous;

[0200] (3) Add pH adjuster to adjust pH to 6 to 8 in the reactor, add other components, and discharge.

[0201] The compositions for inhibiting fabric yellowing in Examples 1 to 6 were prepared according to the formulations in Table 7.

[0202] Table 7 Composition and content of the compositions for inhibiting fabric yellowing in Examples 1 to 6

[0203]

[0204]

[0205] Comparative Examples 1 to 8 were prepared according to the above-described method. Table 8 clearly indicates the differences between Composition Example 2 and Comparative Examples 1 to 8.

[0206] Table 8. Similarities and differences between Composition Example 2 and Comparative Examples 1 to 8

[0207]

[0208] The composition examples and comparative compositions were tested according to the aforementioned method for inhibiting fabric yellowing. The test conditions were as follows: co-culture time was 3 days; 0.5 mL of 3% histidine solution was used; the solvent was physiological saline containing 0.15% tryptone; fabric sample 1 was cotton fabric conforming to GB / T 7568.2-2008; fabric sample 2 was polyester fabric conforming to GB / T 7568.4-2008. The bacteria used were Staphylococcus epidermidis ATCC12228, with a bacterial suspension concentration of 8*10⁻⁶. 5 The bacterial suspension volume was 0.5 mL, with CFU / mL. The solvent for the bacterial suspension was physiological saline in 0.15% tryptic soy peptone broth. Test results are shown in Table 9. The negative control was pure water, 0.2 g. The dE2 value of the cotton fabric treated as a control was 31.3. The dE2 value of the polyester fabric treated as a control was 28.5.

[0209] Composition Example 1: Fabric treated by the method for inhibiting fabric yellowing, such as... Figure 3As shown.

[0210] The fabric treated by the method for inhibiting yellowing of fabrics in Comparative Example 1 is as follows: Figure 4 As shown.

[0211] Table 9 shows the ΔE values ​​of compositions in Examples 1 to 6 and Comparative Examples 1 to 8, as well as the effectiveness of their ability to inhibit fabric yellowing. According to the foregoing, the composition is considered to have the effect of inhibiting fabric yellowing only when the color difference (i.e., ΔE value) between the test group and the control group after treatment is greater than or equal to 20.0. It is evident that compositions in Examples 1 to 6 using the technical solution of this invention have good efficacy in inhibiting fabric yellowing. On the surfaces of cotton and polyester fabrics, the ΔE value after treatment with the technical solution of this invention can reach 20.0 or higher.

[0212] Comparative compositions 1, 2, and 7 used three common chelating agents: sodium ethylenediaminetetraacetate (EDTA), sodium glutamate diacetate (GDI), and sodium tripolyphosphate (PTP). Comparative compositions 3 and 4 used the antioxidant butylated hydroxytoluene (BHT) and vitamin C, respectively. Comparative composition 5 used the reducing agent sodium bisulfite. Comparative composition 6 used the antibacterial agent nano-silver solution. Component A was not used in comparative composition 8. None of these non-inventive technical solutions effectively inhibited yellowing caused by the combined action of histidine and bacteria. This may be because the yellowing of fabrics caused by histidine and bacteria involves a series of chemical reactions related to microbial metabolism, rather than simple oxidation or bacterial proliferation and metabolism. Therefore, chelating agents (inhibiting / disrupting bacterial metabolic processes), reducing agents (inhibiting oxidation reactions), and antibacterial agents (inhibiting / killing bacteria) cannot produce significant anti-yellowing effects.

[0213] Table 9. Composition Examples 1 to 6, and Comparative Examples 1 to 8: ΔE values ​​and efficacy in inhibiting fabric yellowing.

[0214]

[0215] Composition Example 7 and Comparative Examples 9 to 11 were prepared according to the above-described method. Table 10 clearly indicates the differences between Composition Example 7 and Comparative Examples 9 to 11.

[0216] Table 10. Similarities and differences between Composition Example 7 and Composition Comparative Examples 9 to 11

[0217]

[0218] The compositions in Example 7 and Comparative Examples 9 to 11 were tested according to the aforementioned method for inhibiting fabric yellowing. The test conditions were as follows: co-culture time of 3 days; 0.5 mL of 3% histidine solution was used; the solvent was physiological saline containing 0.15% tryptone; the fabric sample was cotton fabric conforming to GB / T7568.2-2008; the bacteria used was Staphylococcus epidermidis ATCC12228, and the bacterial suspension concentration was 8*10⁻⁶. 5 CFU / mL, bacterial suspension volume was 0.5 mL. Test results are shown in Table 11. The negative control was pure water, volume 0.2 g. The dE2 value of the cotton fabric treated in the control was 31.3.

[0219] As shown in Table 11, Composition Example 7 has the effect of inhibiting fabric yellowing. Comparative Composition 9, which uses fatty alcohol polyoxyethylene ether (9) instead of dodecyl dimethylamine oxide as the nonionic surfactant, has a significantly lower ΔE value than Composition Example 2, and does not have the effect of inhibiting fabric yellowing. This indicates that nonionic surfactants not belonging to the technical solution of this invention have a negative antagonistic effect on the yellowing inhibition effect. The content of component A in Comparative Composition 10 is lower than the lower limit required by the technical solution of this invention, and its ΔE value is lower than 20.0, indicating that it does not have the effect of inhibiting fabric yellowing. This indicates that component A must reach a certain concentration to give the composition an effective effect of inhibiting fabric yellowing. The content of component A in Comparative Composition 11 is higher than the upper limit required by the technical solution of this invention, and its ΔE value is further improved compared to Composition Example 7, but the improvement is not significant. From an economic cost perspective, Comparative Composition 11 increases the cost and does not contribute much to the effectiveness, which does not meet the purpose of this invention.

[0220] Table 11. Composition Examples 1 to 7, and Comparative Examples 9 to 11: ΔE values ​​and efficacy in inhibiting fabric yellowing.

[0221]

[0222] Compositions 8 to 9 and comparative compositions 12 to 14 were prepared according to the above-described method. Table XII clearly indicates the differences between compositions 7 to 9 and comparative compositions 12 to 14.

[0223] Table XII. Similarities and differences between Composition Examples 7 to 9 and Composition Comparative Examples 12 to 14

[0224] Similar technical solutions Differences Composition Example 7 Composition Example 2 The amount of sodium salt of ethylenediaminetetramethylene phosphate used is 1.5%. Composition Example 8 Composition Example 1 The amount of sodium salt of diethylenetriaminepentaacetic acid used is 1.5%. Composition Example 9 Composition Example 3 The amount of sodium salt of hydroxyethylidene diphosphate used is 1.5%. Comparative Example 12 Composition Example 7 The amount of polyhydroxypropyl dimethylammonium chloride in component B is 0%. Comparative Example 13 Composition Example 8 The amount of dodecyl dimethyl ammonium chloride in component B is 0%. Comparative Example 14 Composition Example 9 The dosage of sodium ethyl morpholine sulfate (HPS) from soybean is 0%.

[0225] Following the aforementioned long-acting antibacterial test method, long-acting antibacterial tests were conducted on compositions 1 to 9 and comparative compositions 12 to 14. The tested bacterial species were Staphylococcus aureus ATCC6538 and Staphylococcus epidermidis ATCC12228, respectively. The test results are shown in Table XIII.

[0226] The results show that the compositions in Examples 1 to 9 of this invention exhibit a long-lasting antibacterial rate of over 90.0% against Staphylococcus aureus and Staphylococcus epidermidis, common bacteria on the human body surface. This indicates that the fabrics treated with compositions in Examples 1 to 9 have a long-lasting antibacterial effect, achieving the expected beneficial results. However, compositions in Comparative Examples 12 to 14, lacking component B, do not possess a long-lasting antibacterial effect and cannot achieve the expected beneficial results, demonstrating that component B imparts a good long-lasting antibacterial effect to the compositions. From a practical application perspective, compositions that inhibit fabric yellowing must not only inhibit the yellowing caused by the interaction of histidine and bacteria but also possess a good long-lasting antibacterial effect.

[0227] Table XIII. Long-lasting antibacterial efficacy of compositions in Examples 1 to 9 and Comparative Examples 12 to 14

[0228]

[0229] The dimensions and numerical values ​​disclosed herein should not be construed as strict limitations on the precise values ​​stated. Unless otherwise stated, each such dimension is intended to represent the value and a range of functionally equivalent values ​​around that value. For example, a dimension disclosed as “40 mm” is intended to represent “approximately 40 mm”.

[0230] All documents referenced in the invention summary are incorporated herein by reference in the relevant sections. Reference to any document should not be construed as an admission that it is prior art relating to the invention.

[0231] While specific embodiments of the present invention have been illustrated and described, it will be apparent to those skilled in the art that numerous other modifications and variations can be made without departing from the spirit and scope of the invention. All such modifications and variations are included within the protection scope of the present invention.

[0232] The above description describes specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A fabric yellowing agent, characterized in that, Includes a histidine solution with a mass percentage of 1% to 3% and a bacterial concentration of 1*10. 5 CFU / mL up to 9*10 5 A bacterial suspension of CFU / mL; the bacteria refer to one or more of Staphylococcus epidermidis and Micrococcus luteus; The solvent for the histidine solution is physiological saline containing 0.15% to 1% tryptone by mass. The solvent for the bacterial suspension is physiological saline containing 0.1% to 0.2% tryptic soy broth.

2. A method for preventing fabric yellowing, characterized in that, Includes the following steps: The fabric yellowing reagent as described in claim 1 was dropped onto the fabric and cultured for 3 to 4 days at 36±5℃ and 85±5% relative humidity. The specific procedure for the dropwise addition is as follows: first add 0.5 mL of 1% to 3% histidine solution, then add 0.5 mL of 1*10 5 CFU / mL up to 9*10 5 CFU / mL bacterial suspension.

3. A test method for inhibiting yellowing of fabrics, characterized in that, Includes the following steps: The fabrics were degreased and then divided into test and control groups. The fabric samples from the test group underwent surface treatment. The fabrics of the control group were surface-treated with pure water; The fabric yellowing reagent as described in claim 1 was added dropwise to the surface-treated test group fabric and the control group fabric, respectively, and co-cultured at 36±5℃ and 85±5% relative humidity for 3 to 4 days; the specific operation of the dropwise addition was as follows: first add 0.5 mL of 1% to 3% histidine solution, then add 0.5 mL of 1*10 5 CFU / mL up to 9*10 5 CFU / mL bacterial suspension; After sterilization, using the degreased fabric without other treatment as the standard sample, the color difference value dE1 of the test group fabric and the color difference value dE2 of the control group fabric were measured using a colorimeter; the color difference value was taken as the db* value as the test result. Judgment of the effect of inhibiting fabric yellowing: Calculate the difference ΔE between the color difference values ​​of the test group fabric and the control group fabric according to the following formula (1); △E=dE2-dE1 Equation (1); When dE2 is greater than or equal to 25.0 and ΔE is greater than or equal to 20.0, it is determined that it has the effect of inhibiting yellowing of fabrics.

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