A low odor urine indicating adhesive, a method of making the same, and articles comprising the same

Abstract

The application discloses a low-odor urine indicating adhesive as well as a preparation method of the urine indicating adhesive and an article comprising the urine indicating adhesive, relates to the technical field of high polymer materials for absorbing pads and the like, and is prepared from the following components in percentage by mass: 1-10% of liquid polybutadiene rubber, 1-10% of polymer SEPS, 10-30% of a plasticizer, 20-70% of tackifying resin, 3-25% of a surfactant, 0.01-4% of a dye, and 0.1-6% of an ultraviolet absorber, wherein the sum of the percentage by mass of the above components is 100%. The urine indicating adhesive has the effects of low odor, color change before and after water contact not being affected by ultraviolet light, effective avoidance of invalidation of a color developing agent, and no fluorescence, and can be applied to disposable sanitary articles such as baby paper diapers, pet paper diapers, adult incontinence articles and the like.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology for absorbent pads, etc., and particularly to a low-odor hot melt adhesive that shows color when wet with urine, its preparation method, and articles including the urine-indicating adhesive. Background Technology

[0002] With the increasing market demand for disposable diapers, they have largely replaced traditional cloth diapers and are widely used by infants and incontinent adults. Currently, disposable diapers on the market have strong absorbency, making it difficult to notice when they are wet. However, continuing to use a wet diaper can easily cause skin allergies in users (infants, incontinent adults, etc.) in a damp environment. Therefore, timely diaper changing is crucial; otherwise, infants are highly susceptible to skin allergies in a damp environment.

[0003] Urine-indicating color-changing hot melt adhesive, or urine indicator adhesive for short, is a type of hot melt adhesive that changes color when it comes into contact with liquids such as urine. The color change directly reflects the urine condition, allowing users to visually determine whether disposable hygiene products such as diapers or pads need to be changed, without having to touch them to make a judgment.

[0004] Existing urine indicator adhesives typically contain color developers (such as bromocresol green, bromocresol blue, or bromocresol purple). These color developers, upon contact with water, change color rapidly from a primary color (such as yellow) to a secondary color (such as green) due to pH fluctuations, meeting the precise humidity visualization requirements of products like diapers. For details, please refer to the urine indicator adhesive disclosed in patent number ZL201310108779.4, which is the applicant's independently developed first-generation urine indicator adhesive.

[0005] However, the above-mentioned urine indicator gel still has the following defects in practical applications:

[0006] 1. Existing color developers such as bromophenol blue, bromocresol green, and bromocresol purple, or existing rosin-based plasticizers, have strong odors and are not suitable for applications where odor is a concern, such as diapers for infants and young children.

[0007] 2. At the same time, the existing urine indicator adhesive lacks UV protection, which means that if it is not packaged in time during the actual diaper production process, it will change color when exposed to moisture, and then fade after being exposed to ultraviolet light, completely losing the function of the color developer. If diapers with such ineffective urine indicators enter the market, it will have a significant negative impact on the reputation of the entire industry and the credibility of merchants.

[0008] Therefore, it is necessary to develop a urine indicator gel that has both low odor and the function of preventing loss of indication. Summary of the Invention

[0009] In order to overcome the shortcomings of the prior art, one of the objectives of the present invention is to provide a low-odor urine indicator gel.

[0010] The second objective of this invention is to provide a method for preparing a low-odor urine reagent.

[0011] The second objective of this invention is to provide a disposable absorbent product comprising a low-odor urine indicator gel.

[0012] One of the objectives of this invention is achieved by the following technical solution: a low-odor urine indicator is prepared from the following components by mass percentage: 1-10% liquid polybutadiene rubber, 1-10% polymer SEPS, 10-30% plasticizer, 20-70% tackifying resin, 3-25% surfactant, 0.01-4% dye, and 0.1-6% ultraviolet absorber, wherein the sum of the mass percentages of the above components is 100%.

[0013] The dye includes a first dye selected from one or a mixture of two or more of the following: 3-(1,2-dimethyl-3-indolyl)-3-[4-diethylamino-2-methylphenyl]phthalide, 3,3-di(2-diethoxy-4-N,N-diethylaminophenyl)-4-azaphthalide, 6-[ethyl(4-methylphenyl)amino]-3'-methyl-2'-(phenylamino)-spiro[isobenzofuran-1(3H),9'-(9H) tannin]-3-one, and 7-[4-(diethylamino)-2-(hexoxy)phenyl]-7-(1-ethyl-2-methyl-1H-indolyl)furan[3,4-B]pyridin-5(7H)-one;

[0014] The ultraviolet absorber is selected from 2-(2'-hydroxy-5'-methylphenyl)benzotriazole or 2-(-hydroxy-3-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole and 2-(2'-hydroxy-3',5'-ditert-pentylphenyl)benzotriazole in a mass ratio of 1:(0.5-4).

[0015] Furthermore, the low-odor urine indicator is prepared from the following components by mass percentage: 3-8% liquid polybutadiene rubber, 2-6% polymer SEPS, 15-25% plasticizer, 40-60% tackifying resin, 5-20% surfactant, 0.1-3% dye, and 0.5-4% ultraviolet absorber, the sum of the mass percentages of the above components being 100%.

[0016] Furthermore, the low-odor urine indicator is prepared from the following components by mass percentage: 5-6% liquid polybutadiene rubber, 3-4% polymer SEPS, 18-22% plasticizer, 45-55% tackifying resin, 10-15% surfactant, 2-3% dye, and 1.5-3.5% ultraviolet absorber, the sum of the mass percentages of the above components being 100%.

[0017] Furthermore, the liquid polybutadiene rubber is a low molecular weight polybutadiene with no terminal functional groups or containing a small number of functional groups, selected from the grades HB40 and HBD40 of China Petroleum & Chemical Corporation Maoming Branch.

[0018] The SEPS polymer is selected from SEPS polymers with a molecular weight of 60,000-105,000 and a styrene content of 28-35%, and is selected from grades 4051 and 4052 of Hunan Yuehua Chemical Co., Ltd.

[0019] Furthermore, the plasticizer is selected from one or a mixture of two or more of paraffinic rubber oil, naphthenic rubber oil, and aromatic rubber oil; the tackifying resin is selected from one or a mixture of two or more of hydrogenated petroleum resin and hydrogenated rosin resin.

[0020] Furthermore, the surfactant is selected from one or more of nonionic surfactants and anionic surfactants. The nonionic surfactant is selected from one or more of fatty alcohol and ethylene oxide condensate and sorbitan monooleate. The anionic surfactant is selected from one or more of sodium dodecylbenzene sulfonate and sodium dodecyl sulfate. When the surfactant is a mixture of nonionic surfactant and anionic surfactant, the nonionic surfactant and anionic surfactant are compounded in a mass ratio of 1:(2-4).

[0021] Furthermore, the dye also includes a second dye, which is selected from one or more of Solvent Orange 54, Solvent Orange 99, Solvent Red 89, Solvent Orange 62, and Solvent Orange 116, and the first dye and the second dye are compounded in a mass ratio of (40-60):1.

[0022] Furthermore, the ultraviolet absorber is selected from 2-(2'-hydroxy-5'-methylphenyl)benzotriazole or 2-(-hydroxy-3-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole and 2-(2'-hydroxy-3',5'-ditert-pentylphenyl)benzotriazole in a mass ratio of 1:(1-3).

[0023] Furthermore, the low-odor urine indicator gel also includes 0.1-2% by weight of antioxidants.

[0024] The second objective of this invention is achieved by the following technical solution: a method for preparing a low-odor urine reagent, comprising the following steps:

[0025] S1: Confirm that the bottom valve of the reactor is closed, turn on the steam heater, start the agitator, and add the prescribed amount of plasticizer and surfactant;

[0026] S2: Raise the temperature of the reactor in S1 to 140-155℃, add the amount of polymer SEPS specified in the formula, and stir until the polymer melts;

[0027] S3: Add the prescribed amount of dye to the reaction vessel of S2, and mix thoroughly after all the dye has melted;

[0028] S4: Add the formulated amount of tackifying resin to the reactor of S3. After the tackifying resin has completely melted, add the formulated amount of liquid polybutadiene rubber and mix thoroughly.

[0029] S5: Add the prescribed amount of UV absorber to the reaction vessel in S4, and mix thoroughly after all the UV absorber has melted.

[0030] S6: After vacuuming and stirring continuously for 1 hour in S5, filter the molten material in the reactor.

[0031] S7: The molten material filtered in S6 is passed through a cooling system and a drying system in sequence to finally obtain low-odor urea-based gel.

[0032] The third objective of this invention is achieved by the following technical solution: a disposable absorbent product, comprising a first substrate and a low-odor urine indicator adhesive as described above disposed on the first substrate, wherein the product is selected from baby diapers, pet diapers, and adult incontinence products.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0034] The urine indicator gel of this invention has a low odor, its color is unaffected by ultraviolet light before and after contact with water, effectively preventing the color developer from failing, and it can achieve a non-fluorescent effect. This urine indicator gel can be applied to disposable hygiene products such as baby diapers, pet diapers, and adult incontinence products. Attached Figure Description

[0035] Figure 1 This is a photograph of the urine indicator color test results of the present invention;

[0036] Figure 2 These are photographs showing the results of the UV resistance test of the urine indicator gel of the present invention before and after.

[0037] Figure 3Photographs showing the results of UV resistance testing of the first-generation urine indicator gel in Comparative Example 11;

[0038] Figure 4 These are photographs showing the results before and after the wettability test of the urine indicator gel of the present invention;

[0039] Figure 5 Photos showing the results of the first-generation urine indicator gel before and after the moisture resistance test in Comparative Example 11;

[0040] Figure 6 The images show the fluorescence test results of the urine-based reagents of the present invention and Comparative Example 11. Detailed Implementation

[0041] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0042] In this invention, unless otherwise specified, all parts and percentages are by weight, and the equipment and raw materials used are commercially available or commonly used in the art. Unless otherwise specified, the methods in the following embodiments are conventional methods in the art.

[0043] This invention provides a low-odor urine indicator, prepared from the following components by mass percentage: 1-10% liquid polybutadiene rubber, 1-10% polymer SEPS, 10-30% plasticizer, 20-70% tackifying resin, 3-25% surfactant, 0.01-4% dye, and 0.1-6% ultraviolet absorber, wherein the sum of the mass percentages of the above components is 100%.

[0044] The dye includes a first dye selected from one or a mixture of two or more of the following: 3-(1,2-dimethyl-3-indolyl)-3-[4-diethylamino-2-methylphenyl]phthalide, 3,3-di(2-diethoxy-4-N,N-diethylaminophenyl)-4-azaphthalide, 6-[ethyl(4-methylphenyl)amino]-3'-methyl-2'-(phenylamino)-spiro[isobenzofuran-1(3H),9'-(9H) tannin]-3-one, and 7-[4-(diethylamino)-2-(hexoxy)phenyl]-7-(1-ethyl-2-methyl-1H-indolyl)furan[3,4-B]pyridin-5(7H)-one;

[0045] The ultraviolet absorber is selected from 2-(2'-hydroxy-5'-methylphenyl)benzotriazole or 2-(-hydroxy-3-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole and 2-(2'-hydroxy-3',5'-ditert-pentylphenyl)benzotriazole in a mass ratio of 1:(0.5-4).

[0046] This invention constructs a stable colloidal system by compounding liquid polybutadiene rubber, polymer SEPS, plasticizer, tackifying resin and other components, and introduces specific dyes and ultraviolet absorbers to improve the colloidal odor tolerance, rapid color development response and the ability of the color to be unaffected by ultraviolet light before and after contact with water.

[0047] Specifically, to achieve a low odor, this application removes bromophenol blue, bromocresol green, and bromocresol purple from the pH color indicators. Furthermore, it screens dyes that, when the first dye combines with water, can turn blue, green, or brown, allowing for the visual assessment of humidity in products such as diapers. With the cooperation of other components, it achieves rapid and stable color development, making it particularly suitable for applications such as diaper displays. Simultaneously, by screening the types of ultraviolet absorbers and the compounding process, it solves both the technical problem of color developer failure due to moisture ingress during diaper production (due to delayed packaging) and the fluorescence problem caused by dyes and other components, meeting national standards for fluorescent substance testing in diapers.

[0048] The urine indicator gel of this invention has low odor, its color is unaffected by ultraviolet light before and after contact with water, and it is non-fluorescent. Furthermore, this urine indicator gel also has high moisture resistance. The urine indicator gel made according to this invention can be used in disposable hygiene products such as baby diapers, pet diapers, and adult incontinence products.

[0049] As a further preferred embodiment, the low-odor urine indicator is prepared from the following components by mass percentage: 3-8% liquid polybutadiene rubber, 2-6% polymer SEPS, 15-25% plasticizer, 40-60% tackifying resin, 5-20% surfactant, 0.1-3% dye, and 0.5-4% ultraviolet absorber, the sum of the mass percentages of the above components being 100%.

[0050] As a further preferred embodiment, the low-odor urine indicator is prepared from the following components by mass percentage: 5-6% liquid polybutadiene rubber, 3-4% polymer SEPS, 18-22% plasticizer, 45-55% tackifying resin, 10-15% surfactant, 2-3% dye, and 1.5-3.5% ultraviolet absorber, the sum of the mass percentages of the above components being 100%.

[0051] As a further preferred embodiment, the liquid polybutadiene rubber is a low molecular weight polybutadiene with no or few terminal functional groups, selected from the grades HB40 and HBD40 of China Petroleum & Chemical Corporation Maoming Branch. The use of liquid polybutadiene rubber in this formulation can increase the surface tack and wettability of the hot melt adhesive to the substrate.

[0052] The SEPS polymer is selected from SEPS polymers with a molecular weight of 60,000-105,000 and a styrene content of 28-35%, and is selected from one or more of the following SEPS polymers, including but not limited to Hunan Yuehua Chemical Co., Ltd.'s grades 4051 (molecular weight 62,000, styrene content 30%) and 4052 (molecular weight 105,000, styrene content 33%). The use of SEPS polymers in this formulation can improve the cohesive strength of the urine indicator gel.

[0053] As a further preferred embodiment, the plasticizer is selected from one or a mixture of two or more of paraffinic rubber oil, naphthenic rubber oil, and aromatic rubber oil; paraffinic rubber oil, naphthenic rubber oil, and aromatic rubber oil are all petroleum-based rubber oils, and all have good compatibility with the polymer SEPS of the present invention. More preferably, paraffinic rubber oil has better compatibility with SEPS.

[0054] The tackifying resin is selected from one or a mixture of two or more hydrogenated petroleum resins and hydrogenated rosin resins. The tackifying resins in the formulation of this invention are mainly hydrogenated petroleum resins and hydrogenated rosin resins. Compared with other rosin-based plasticizers, they have a lower odor. Hydrogenated C5 petroleum resin and hydrogenated water-based white rosin are further preferred, as they can improve the peel strength of hot melt adhesives and impart a certain initial tack, thus improving the processing and application performance of urea-sensitive adhesives. The hydrogenated C5 petroleum resins are mainly C-100W and C-100L from Eastman Chemical Company of the United States or Nanjing Yangzi Eastman Chemical Co., Ltd. The hydrogenated water-based white rosin is mainly KS2100 from Guangdong Kemao Forest Chemical Group Co., Ltd. and RHR-301 from Guangxi Wuzhou Richeng Forest Products Chemical Co., Ltd.

[0055] As a further preferred embodiment, the surfactant is selected from one or more of nonionic surfactants and anionic surfactants. More preferably, when the surfactant is a mixture of nonionic surfactants and anionic surfactants, the nonionic surfactants and anionic surfactants are compounded in a mass ratio of 1:(2-4).

[0056] The nonionic surfactant is selected from one or more of the following: fatty alcohol and ethylene oxide condensate (such as the Pinto-PineO series, O-20) and sorbitan monooleate (such as the Span series, Span 20, Span 40, Span 60, Span 80), preferably a fatty alcohol and ethylene oxide condensate. The nonionic surfactant selected in this invention has good wetting and dispersing properties, can reduce the surface tension of the liquid, and allows the liquid to better contact and spread on the solid surface.

[0057] The anionic surfactant is selected from one or a mixture of two or more of sodium dodecylbenzenesulfonate and sodium dodecyl sulfate, preferably sodium dodecylbenzenesulfonate. The anionic surfactant selected in this invention has good emulsifying properties, good wetting and penetrating properties, allowing the liquid to better penetrate into the urine indicator gel.

[0058] As a further preferred embodiment, the dye further includes a second dye, which is selected from one or more of Solvent Orange 54, Solvent Orange 99, Solvent Red 89, Solvent Orange 62, and Solvent Orange 116. The first dye and the second dye are compounded at a mass ratio of (40-60):1. The second dye imparts an initial color to the urine indicator gel in the dry state, primarily orange-yellow. When the first dye combines with water, it can turn into darker colors such as blue, green, and brown, thereby increasing the color difference between the dry and wet states of the urine indicator gel and making it easier to perceive the degree of color change.

[0059] As a further preferred embodiment, the ultraviolet absorber is selected from 2-(2'-hydroxy-5'-methylphenyl)benzotriazole or 2-(-hydroxy-3-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole and 2-(2'-hydroxy-3',5'-ditert-pentylphenyl)benzotriazole in a mass ratio of 1:(1-3). The most preferred mixing ratio is 1:1.5. The dye, tackifying resin and surfactant of the present invention are all fluorescent. By using two specific ultraviolet absorbers in combination, a non-fluorescent effect can be achieved, and the color before and after contact with salt water is not affected by ultraviolet light.

[0060] As a further preferred embodiment, the low-odor urine indicator gel also includes 0.1-2% by weight of an antioxidant. The antioxidant in the formulation of this invention serves to prevent polymer oxidation, which leads to macromolecular chain breakage, cross-linking, and performance degradation. The antioxidant is selected from one or a combination of antioxidant 1010 and antioxidant 168.

[0061] This application also provides a method for preparing the low-odor urine reagent as described above, comprising the following steps:

[0062] S1: Confirm that the bottom valve of the reactor is closed, turn on the steam heating, start the agitator, and add the formulated amount of plasticizer, surfactant, and antioxidant (if any).

[0063] S2: Raise the temperature of the reactor in S1 to 140-155℃, add the amount of polymer SEPS specified in the formula, and stir until the polymer melts;

[0064] S3: Add the prescribed amount of dye to the reaction vessel of S2, and mix thoroughly after all the dye has melted;

[0065] S4: Add the formulated amount of tackifying resin to the reactor of S3. After the tackifying resin has completely melted, add the formulated amount of liquid polybutadiene rubber and mix thoroughly.

[0066] S5: Add the prescribed amount of UV absorber to the reaction vessel in S4, and mix thoroughly after all the UV absorber has melted.

[0067] S6: After vacuuming and stirring continuously for 1 hour in S5, filter the molten material in the reactor.

[0068] S7: The molten material filtered in S6 is passed through a cooling system and a drying system in sequence to finally obtain low-odor urea-based gel.

[0069] The present invention also provides a disposable absorbent article comprising a first substrate and a low-odor urine indicator as described above disposed on the first substrate, wherein the article is selected from baby diapers, pet diapers, and adult incontinence products.

[0070] The following are specific embodiments of the present invention. Unless otherwise specified, the raw materials, equipment and other materials used in the following embodiments can be obtained by purchasing.

[0071] Examples 1-3 and Comparative Examples 1-11

[0072] Weigh the raw materials according to the proportions in Table 1, and prepare the urine indicator gel according to the preparation method in Table 1 to obtain urine indicator gels for different embodiments:

[0073] Table 1 Raw material ratio table for Examples 1-3

[0074]

[0075] In Table 1, the tackifying resin of Example 1 is composed of 33% C-100L and 18% Ks2100. The surfactant is composed of 4% nonionic surfactant O-20 and 9% anionic surfactant sodium dodecylbenzenesulfonate. The dyes are 3-(1,2-dimethyl-3-indolyl)-3-[4-diethylamino-2-methylphenyl]phthalide and solvent orange 54 in a mass ratio of 50:1. The UV absorber is composed of 2-(2'-hydroxy-5'-methylphenyl)benzotriazole and 2-(2'-hydroxy-3',5'-diterpentylphenyl)benzotriazole in a mass ratio of 1:1.5.

[0076] In Example 2, RHR-301 was selected as the tackifying resin, and 2% of the nonionic surfactant Span60 and 3% of the anionic surfactant sodium dodecylbenzenesulfonate were selected as the surfactants. The mass ratio of the first dye 7-[4-(diethylamino)-2-(hexoxy)phenyl]-7-(1-ethyl-2-methyl-1H-indol-3-yl)furano[3,4-B]pyridine-5(7H)-one to the second dye solvent Orange 89 was 45:1. The ultraviolet absorber was 2-(-hydroxy-3-tert-butyl-5"-methylphenyl)-5-chlorobenzotriazole and 2-(2'-hydroxy-3',5'-ditert-pentylphenyl)benzotriazole in a mass ratio of 1:0.5.

[0077] In Example 3, C-100W was selected as the tackifying resin, and Span 60 was selected as the nonionic surfactant. The mass ratio of the first dye, 6-[ethyl(4-methylphenyl)amino]-3'-methyl-2'-(phenylamino)-spiro[isobenzofuran-1(3H),9'-(9H)-tannin]-3-one, to the second dye, solvent Orange 54, was 55:1. The ultraviolet absorber was selected from 2-(2'-hydroxy-5'-methylphenyl)benzotriazole and 2-(2'-hydroxy-3',5'-diterpentylphenyl)benzotriazole in a mass ratio of 1:3.

[0078] The preparation methods of the urine indicator gel in Examples 1-3 include the following steps:

[0079] S1: Confirm that the bottom valve of the reactor is closed, turn on the steam heating, start the agitator, and add the formulated amount of plasticizer, surfactant, and antioxidant (if any).

[0080] S2: Raise the temperature of the reactor in S1 to 140-155℃, add the amount of polymer SEPS specified in the formula, and stir until the polymer melts;

[0081] S3: Add the prescribed amount of dye to the reaction vessel of S2, and mix thoroughly after all the dye has melted;

[0082] S4: Add the formulated amount of tackifying resin to the reactor of S3. After the tackifying resin has completely melted, add the formulated amount of liquid polybutadiene rubber and mix thoroughly.

[0083] S5: Add the prescribed amount of UV absorber to the reaction vessel in S4, and mix thoroughly after all the UV absorber has melted.

[0084] S6: After the reaction in S5 is completed, filter the molten material in the reactor;

[0085] S7: The molten material filtered in S6 is passed through a cooling system and a drying system in sequence to obtain urine indicator gel.

[0086] Comparative Example 1

[0087] Compared with the urine indicator gel of Example 1, the formulation of Comparative Example 1 is different in that it lacks a UV absorber. The amount of the missing UV absorber is made up by the amount of tackifying resin. The rest of the formulation, amount, and preparation method are the same as those of Example 1.

[0088] Comparative Example 2

[0089] Compared with the urine indicator gel of Example 1, the formulation of Comparative Example 2 is different in that: the ultraviolet absorber used is benzophenone-based ultraviolet absorber UV-531 (2-hydroxy-4-n-octyloxybenzophenone), and the rest of the formulation, dosage and preparation method are the same as those of Example 1.

[0090] Comparative Example 3

[0091] Compared with the urine indicator gel of Example 1, the formulation of Comparative Example 3 is different in that: the ultraviolet absorber is not compounded, and only 2-(2'-hydroxy-5'-methylphenyl)benzotriazole is selected. The rest of the formulation, dosage and preparation method are the same as those of Example 1.

[0092] Comparative Example 4

[0093] Compared with the urine indicator gel of Example 1, the formulation of Comparative Example 4 is different in that the ultraviolet absorber is not compounded, and only 2-(-hydroxy-3-tert-butyl-5"-methylphenyl)-5-chlorobenzotriazole is used. The rest of the formulation, dosage and preparation method are the same as those of Example 1.

[0094] Comparative Example 5

[0095] Compared with the urine indicator gel of Example 1, the formulation of Comparative Example 5 differs in that the ultraviolet absorber is not compounded, and only 2-(2'-hydroxy-3',5'-diterpentylphenyl)benzotriazole is used. The rest of the formulation, dosage and preparation method are the same as those of Example 1.

[0096] Comparative Example 6

[0097] Compared with the urine indicator gel of Example 1, the formulation of Comparative Example 6 is different in that the polymer is different, using SIS1300, while the rest of the formulation, dosage, and preparation method are the same as those of Example 1.

[0098] Comparative Example 7

[0099] Compared with the urine indicator gel of Example 1, the formulation of Comparative Example 7 is different in that the surfactant is different, and polyethylene glycol PEG1450 is used. The rest of the formulation, dosage and preparation method are the same as those of Example 1.

[0100] Comparative Example 8

[0101] Compared with the urine indicator gel of Example 1, the formulation of Comparative Example 8 is different in that the tackifying resin is different, and rosin resin is used. The rest of the formulation, dosage and preparation method are the same as those of Example 1.

[0102] Comparative Example 9

[0103] Compared with the urine indicator gel of Example 1, the preparation method of Comparative Example 9 is different in that: in step S2, the temperature of the reactor is raised to 135°C, and then the polymer is added and stirred until the polymer melts. The rest of the formula, dosage and preparation method are the same as those of Example 1.

[0104] Comparative Example 10

[0105] Compared with the urine indicator gel of Example 1, the preparation method of Comparative Example 10 is different in that: in step S2, the temperature of the reactor is raised to 160°C, and then the polymer is added and stirred until the polymer melts. The rest of the formula, dosage and preparation method are the same as those of Example 1.

[0106] Comparative Example 11

[0107] Comparative Example 11 is a first-generation urine indicator gel containing bromophenol blue, bromocresol green and other colorimetric agents with strong odors. It is a urine indicator gel prepared by the formulation and preparation method of Example 3 of Patent ZL201310108779.4.

[0108] Effect evaluation and performance testing

[0109] The performance of the urine indicator gel in the example was tested. The test items and results are shown in Table 2.

[0110] 1. Viscosity testing methods

[0111] Viscosity was determined according to GB / T 2794 using a DV2TRVT viscometer and a No. 27 rotor from Bollefeld, USA. Results were recorded in centipoises (cps).

[0112] 2. Softening point test method

[0113] The softening point was tested according to GB / T 15332 using the SD-0606T automatic softening point tester from the Shanghai Institute of Geosciences Instrumentation. Results were recorded in degrees Celsius (°C).

[0114] 3. Color-changing speed test method

[0115] The prepared urine indicator gel was coated onto a PE film, and then a prototype diaper was made. 0.9% saline solution was poured in, and the color change time of the urine indicator gel was recorded.

[0116] 4. Moisture resistance test method

[0117] The prepared urine indicator gel was coated onto a PE film, and then a diaper prototype was made. The prototype was placed in a constant temperature and humidity chamber for 7 days, with the temperature set at 40℃ and the humidity at 90% and 80%, and the color change was observed.

[0118] 5. Aging resistance test

[0119] The prepared urine indicator gel was coated onto a PE film, and then a prototype diaper was made. The diaper was placed in an oven at 60℃ for 3 days, and the color change was observed.

[0120] 6. UV resistance test

[0121] The prepared urine indicator gel was coated onto a PE film, and then a prototype diaper was made. The diaper was placed in sunlight for 3 days, and the initial color of the diaper after 3 days of sunlight exposure was recorded. 0.9% saline solution was poured in, and the urine indicator gel was observed to change color. The final color of the diaper was recorded.

[0122] 7. Determination of migratable fluorescent substances

[0123] The prepared urine indicator gel was coated onto a PE film, and then a prototype diaper was made. The determination of migratable fluorescent substances was performed according to GB / T 28004.1—2021.

[0124] 8. Odor Evaluation Test Methods

[0125] The odor level was evaluated according to the industry standard HG / T 4065-2008. A 20g sample was placed in a beaker, sealed with aluminum foil, and then placed in a 120℃ oven. After 1 hour, the beaker was removed and cooled to room temperature. The odor assessment team members then determined the odor level based on the sample's odor.

[0126] Table 2 shows the test data of urine gel performance for each example.

[0127]

[0128] As shown in Table 2 above and the appendix Figure 1-6As can be seen, the urine indicator gel prepared by this invention has low odor, high moisture resistance, obvious initial color, and obvious color change upon contact with physiological saline. Furthermore, the color before and after contact with physiological saline is not affected by ultraviolet light, achieving a non-fluorescent effect. The urine indicator gel prepared by this invention can be applied to disposable hygiene products such as baby diapers, pet diapers, and adult incontinence products.

[0129] Compared with Example 1, the urine indicator gel of Comparative Example 1 differs in that it lacks a UV absorber. The urine indicator gel produced has fluorescence, and after being tested with ultraviolet light, it does not change color when 0.9% saline is poured in.

[0130] The difference in the formulation of Comparative Example 2 urine indicator gel lies in the use of only the conventional UV-531 as the UV absorber. The resulting urine indicator gel exhibits fluorescence, and after UV testing, it does not change color when mixed with 0.9% physiological saline. This demonstrates that not all UV absorbers can effectively improve the fluorescence of colloids.

[0131] The difference in the formulation of the comparative ratio 3-5 urine indicator gel lies in the fact that the ultraviolet absorber is not compounded, thus failing to achieve the effect of defluorination.

[0132] The difference in formulation between Comparative Example 6 and the urine indicator gel lies in the different polymers used. SIS1300 was used, resulting in a urine indicator gel with lower viscosity and softening point, and weaker cohesion, which had a certain impact on the color development effect.

[0133] The difference in the formulation of Comparative Example 7 urine indicator gel lies in the use of nonionic surfactant polyethylene glycol PEG1450, which makes the urine indicator gel colorless after being mixed with physiological saline.

[0134] The difference in the formulation of Comparative Example 8 urine indicator gel lies in the use of rosin resin as the tackifying resin, which has a strong odor.

[0135] The difference in the preparation methods of urine indicator gels in Comparative Examples 9-10 lies in step S2. If the temperature of the reaction vessel is too low or too high, the polymer is easily degraded, and the viscosity will be too low. If the temperature is too low, the polymer and dye cannot be completely melted, which will affect the color change of the urine indicator gel.

[0136] Comparative Example 11, a first-generation urine indicator gel, contains bromophenol blue and bromocresol green, which have strong odors, limiting its applicability as a disposable product. Furthermore, this urine indicator gel is not resistant to ultraviolet radiation; the color developer becomes ineffective after exposure to ultraviolet light.

[0137] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A low-odor urine indicator gel, characterized in that, It is prepared from the following components by mass percentage: 1-10% liquid polybutadiene rubber, 1-10% polymer SEPS, 10-30% plasticizer, 20-70% tackifying resin, 3-25% surfactant, 0.01-4% dye, and 0.1-6% ultraviolet absorber, wherein the sum of the mass percentages of the above components is 100%. The dye comprises a first dye and a second dye, wherein the first dye is selected from 3-(1,2-dimethyl-3-indolyl)-3-[4-diethylamino-2-methylphenyl]phthalide, 3,3-bis(2-diethoxy-4-N,N-diethylaminophenyl)-4-azaphthalide, 6-[ethyl(4-methylphenyl)amino]-3'-methyl-2'-(phenylamino)-spiro[isobenzofuran-1(3H),9'-(9H)-zanton]-3-one, 7-[ The first dye is selected from one or a mixture of two or more of [4-(diethylamino)-2-(hexyloxy)phenyl]-7-(1-ethyl-2-methyl-1H-indol-3-yl)furano[3,4-B]pyridin-5(7H)-one; the second dye is selected from one or a mixture of two or more of Solvent Orange 54, Solvent Orange 99, Solvent Red 89, Solvent Orange 62, and Solvent Orange 116, and the first dye and the second dye are compounded in a mass ratio of (40-60):

1. The ultraviolet absorber is selected from 2-(2'-hydroxy-5'-methylphenyl)benzotriazole or 2-(2-hydroxy-3-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole and 2-(2'-hydroxy-3',5'-ditert-pentylphenyl)benzotriazole in a mass ratio of 1:(0.5-4); The tackifying resin is selected from one or a mixture of two of hydrogenated petroleum resin and hydrogenated rosin resin; The surfactant is a mixture of nonionic surfactant and anionic surfactant, which are compounded in a mass ratio of 1:(2-4). The nonionic surfactant is selected from one or a mixture of two of fatty alcohol and ethylene oxide condensate and sorbitan monooleate. The anionic surfactant is selected from one or a mixture of two of sodium dodecylbenzenesulfonate and sodium dodecyl sulfate.

2. The low-odor urine indicator gel as described in claim 1, characterized in that, It is prepared from the following components by mass percentage: 3-8% liquid polybutadiene rubber, 2-6% polymer SEPS, 15-25% plasticizer, 40-60% tackifying resin, 5-20% surfactant, 0.1-3% dye, and 0.5-4% ultraviolet absorber, the sum of the mass percentages of the above components being 100%.

3. The low-odor urine indicator gel as described in claim 1, characterized in that, It is prepared from the following components by mass percentage: 5-6% liquid polybutadiene rubber, 3-4% polymer SEPS, 18-22% plasticizer, 45-55% tackifying resin, 10-15% surfactant, 2-3% dye, and 1.5-3.5% ultraviolet absorber, the sum of the mass percentages of the above components being 100%.

4. The low-odor urine indicator gel according to any one of claims 1-3, characterized in that, The liquid polybutadiene rubber is a low molecular weight polybutadiene with no or few functional groups at the end, selected from the grades HB40 and HBD40 of China Petroleum & Chemical Corporation Maoming Branch. The SEPS polymer is selected from SEPS polymers with a molecular weight of 60,000-105,000 and a styrene content of 28-35%, and is selected from grades 4051 and 4052 of Hunan Yuehua Chemical Co., Ltd.

5. The low-odor urine indicator gel according to any one of claims 1-3, characterized in that, The plasticizer is selected from one or a mixture of two or more of paraffinic rubber oil, naphthenic rubber oil, and aromatic rubber oil.

6. A low-odor urine indicator gel, characterized in that, It is prepared from the following components by mass percentage: 1-10% liquid polybutadiene rubber, 1-10% polymer SEPS, 10-30% plasticizer, 20-70% tackifying resin, 3-25% surfactant, 0.01-4% dye, 0.1-6% ultraviolet absorber, and 0.1-2% antioxidant, wherein the sum of the mass percentages of the above components is 100%. The dye comprises a first dye and a second dye, wherein the first dye is selected from 3-(1,2-dimethyl-3-indolyl)-3-[4-diethylamino-2-methylphenyl]phthalide, 3,3-bis(2-diethoxy-4-N,N-diethylaminophenyl)-4-azaphthalide, 6-[ethyl(4-methylphenyl)amino]-3'-methyl-2'-(phenylamino)-spiro[isobenzofuran-1(3H),9'-(9H)-zanton]-3-one, 7-[ The first dye is selected from one or a mixture of two or more of [4-(diethylamino)-2-(hexyloxy)phenyl]-7-(1-ethyl-2-methyl-1H-indol-3-yl)furano[3,4-B]pyridin-5(7H)-one; the second dye is selected from one or a mixture of two or more of Solvent Orange 54, Solvent Orange 99, Solvent Red 89, Solvent Orange 62, and Solvent Orange 116, and the first dye and the second dye are compounded in a mass ratio of (40-60):

1. The ultraviolet absorber is selected from 2-(2'-hydroxy-5'-methylphenyl)benzotriazole or 2-(2-hydroxy-3-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole and 2-(2'-hydroxy-3',5'-ditert-pentylphenyl)benzotriazole in a mass ratio of 1:(0.5-4); The tackifying resin is selected from one or a mixture of two of hydrogenated petroleum resin and hydrogenated rosin resin; The surfactant is a mixture of nonionic surfactant and anionic surfactant, which are compounded in a mass ratio of 1:(2-4). The nonionic surfactant is selected from one or a mixture of two of fatty alcohol and ethylene oxide condensate and sorbitan monooleate. The anionic surfactant is selected from one or a mixture of two of sodium dodecylbenzenesulfonate and sodium dodecyl sulfate.

7. A method for preparing a low-odor urine indicator gel as described in any one of claims 1-5, characterized in that, Includes the following steps: S1: Confirm that the bottom valve of the reactor is closed, turn on the steam heater, start the agitator, and add the prescribed amount of plasticizer and surfactant; S2: Raise the temperature of the reactor in S1 to 140-155℃, add the amount of polymer SEPS specified in the formula, and stir until the polymer melts; S3: Add the prescribed amount of dye to the reaction vessel of S2, and mix thoroughly after all the dye has melted; S4: Add the formulated amount of tackifying resin to the reactor of S3. After the tackifying resin has completely melted, add the formulated amount of liquid polybutadiene rubber and mix thoroughly. S5: Add the prescribed amount of UV absorber to the reaction vessel in S4, and mix thoroughly after all the UV absorber has melted. S6: After vacuuming and stirring continuously for 1 hour in S5, filter the molten material in the reactor. S7: The molten material filtered in S6 is passed through a cooling system and a drying system in sequence to finally obtain low-odor urea-based gel.

8. A disposable absorbent product, characterized in that, The product includes a first substrate and a low-odor urine indicator as described in any one of claims 1-6 or prepared by the method described in claim 7, wherein the product is selected from baby diapers, pet diapers, and adult incontinence products.

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