Hot melt adhesive for detecting analytes in urine

Abstract

The present invention relates to a hot melt adhesive for disposable articles for personal hygiene with the ability to detect the presence of analytes in urine that are indicative of urinary tract pathology. The present invention allows for early detection of potential health complications so that patients can immediately consult a general practitioner to avoid further health effects. The hot melt adhesive is composed of a polymer component, a resin component, a plasticizer component, a surfactant component, a reagent component, and an antioxidant component. The present invention also describes a method for the manufacture and application of the hot melt adhesive due to its light-sensitive properties.

Description

[Technical field]

[0001] The present invention relates to hot melt adhesive compositions, and more particularly to hot melts for detecting analytes in urine, which are applied to disposable articles for personal hygiene.

[0002] [Background of the invention] Urine is an aqueous solution secreted by the kidneys and is made up of more than 95% water. The remaining components of healthy urine are urea, chloride, sodium, potassium, creatinine and dissolved ions.

[0003] Abnormal composition or abnormal characteristics of urine usually indicate a health problem, such as a urinary tract infection. These infections occur when bacteria reach the urinary tract through the urethra and begin to grow in the bladder. Some people are more prone to developing urinary tract infections than others. For example, women are more susceptible to urinary tract infections because they have a shorter urethra compared to men. Diseases that suppress the immune system, such as diabetes and urinary tract abnormalities common in infants, increase the risk of developing an infection. Studies have revealed that approximately 20% of women over 65 years of age have a urinary tract infection, compared to 11% of the overall population, and the prevalence of infections increases with age.

[0004] Most common urinary tract infections are uncomplicated and have no associated functional or anatomical abnormalities. However, there is a risk of developing recurrent infections or more severe infections that can potentially damage the kidneys, so medical treatment is always recommended. The primary infectious agent of both uncomplicated and complicated urinary tract infections is the gram-negative bacterium Escherichia coli (E. coli).

[0005] A urinary tract infection leads to changes in several physiological parameters, such as changes in urine color, clarity, odor and / or pH, as well as the possible presence of protein, nitrite, ketones, glucose and / or blood cells in the urine. Of these components, the presence of nitrite can be used to detect a urinary tract infection, because the bacteria causing the infection produce the enzyme nitrate reductase, which converts nitrate to nitrite.

[0006] Other analytes such as glucose and protein, also found in urinary tract infections, are indicative of other pathologies such as type 2 diabetes and kidney disease, respectively. Diabetes is characterized by an excess of glucose in the blood, and the way to remove this excess from the body is through urine. Kidney disease can be associated with damage to the nephrons, such as in nephrotic syndrome, which causes greater amounts of blood proteins and other proteins associated with body damage, such as C-reactive protein, to be lost in the urine. Other analytes, such as sodium, chloride, potassium, creatine, creatinine, calcium, phosphate, and others, can also be lost in the urine in unhealthy amounts, with less creatinine being lost in the presence of kidney complications.

[0007] Rapid detection methods already exist for some of these analytes: nitrite is detected by a rapid screening method for possible asymptomatic infections caused by nitrate-reducing bacteria, and glucose by a blood glucose meter, the method primarily used to test for diabetes, which features a finger prick to draw blood into a detector to measure the amount of glucose present in the blood.

[0008] For other analytes, quantitative analysis remains the most ideal way to detect their presence. For creatine and creatinine, chromatographic methods are mostly used. For proteins, total protein tests are applied.

[0009] Although rapid screening tests are more rapid, they cannot replace urinalysis and microscopy as diagnostic tools, nor subsequent monitoring. The presence of these analytes may be associated with other complications not related to renal function, so methods of quantification are necessary. In the case of urinary tract infections, many other microorganisms that do not reduce nitrates (such as gram-positive bacteria and yeasts) can also cause infections of the urinary tract.

[0010] Nevertheless, the use of techniques capable of detecting analytes in urine offers various advantages for the patient. The most obvious benefit is a rapid preliminary diagnosis. By recognizing the signs of a possible health problem, the patient can be referred to a general practitioner who can then be further referred to a doctor specializing in the type of pathology the patient may exhibit. In this way, the application of more efficient diagnostic methods aimed at confirming a preliminary diagnosis can effectively reduce the amount of tests performed and the time spent diagnosing the pathology. This rapid initiation of treatment makes it possible to prevent further health problems resulting from early lesions.

[0011] The present invention relates to a hot melt adhesive composition capable of detecting urinary tract complications by detecting the presence of an analyte in urine, the hot melt being applied to a disposable article for personal hygiene. The detection of the analyte is made possible by incorporating a reagent that reacts with a specific analyte in the sample to form a colored compound.

[0012] By incorporating such a reagent into the hot melt adhesive composition, the product of the present invention changes color in the presence of the analyte. This allows possible urinary tract complications to be detected and treatment to be initiated sooner. Among patients who require a rapid diagnosis of urinary tract complications, newborns and infants are of paramount importance, as they are unable to communicate and urine collection is difficult. Furthermore, bedridden individuals tend to have difficulty communicating the presence of symptoms to caregivers, which may delay treatment and significantly worsen their already compromised health. In such cases, application of the hot melt adhesive of the present invention to the backsheet area of ​​sanitary disposable articles, i.e., but not limited to, diapers and sanitary napkins, allows for easier identification of individuals with urinary tract complications. Furthermore, since the adhesive is light sensitive, the present invention also relates to a method for protecting the hot melt from light throughout the manufacturing and application process.

[0013] Additionally, hot melt adhesives may be used in other types of disposable articles such as, but not limited to, bandages, swabs, and dressings. [Background technology]

[0014] In 1964, Boehringer Mannheim (now Roche) introduced the first Combur test strips. Although the appearance of the test strip has changed little since the 1960s, it has since incorporated several innovations. New impregnation techniques, more stable color indicators, and steadily improving color gradations have all contributed to the established use of urine test strips in clinical and general practice as a reliable diagnostic tool.

[0015] Today, there are several commercial kits that detect the presence of an analyte based on a visual color change, such as urine test strips or dipsticks. The urine test method consists of immersing a test strip completely in a well-mixed urine sample for a short time, then removing it from the container and applying the end of the strip to the opening of the container to remove excess urine. The strip is then left for the time required for the reaction to occur (usually 1-2 minutes), and finally the color that appears is compared to a color scale provided by the manufacturer.

[0016] One drawback of this method is that improper technique can produce erroneous results, for example, white and red blood cells can settle to the bottom of the container and go undetected if the sample is not properly mixed. Similarly, if excess urine is left on the strip after removal from the test sample, reagents can leak from the pad onto adjacent pads, causing color mixing and distortion.

[0017] Several patent documents have been found that refer to techniques for detecting analytes in urine. For example, US Pat. No. 5,399,433 refers to a sensor that can detect the presence of analytes such as nitrite in body fluids and that can be incorporated into sanitary disposable articles. However, this document is about electronic inventions and not about hot melt adhesives. [Prior art documents] [Patent documents]

[0018] [Patent Document 1] International Publication No. 2021 / 195657 Summary of the Invention [Problem to be solved by the invention]

[0019] With regard to hot melt adhesives capable of detecting analytes in body fluids, no documents have been found that mention or suggest the use of this technology in hot melt adhesives. [Means for solving the problem]

[0020] [Advantages of the invention] It is clear that the state of the art has evolved to accommodate the ever-increasing demands of technology. Disposable articles for personal hygiene capable of detecting the presence of analytes would be of great value to hospitals and nursing homes, as they would allow for the rapid detection of urinary tract complications, thus allowing for early diagnosis of diseases and thereby avoiding other health consequences that may result from these complications.

[0021] According to the current state of the art, the product of the invention is intended to be suitable for the most demanding technology in disposable products for personal hygiene. The invention signals the presence of a urinary tract complication by changing the color of the hot melt adhesive in the presence of nitrite, for example from white to red. The more intense the color, the higher the concentration of the analyte.

[0022] However, the greatest advantage that can be realized from the use of hot melt adhesive compositions with the ability to detect the presence of analytes in urine is that when applied to sanitary disposable products, it is possible to quickly detect signs related to urinary complications without the patient having to communicate any symptoms to a caregiver. As mentioned above, this is extremely important for newborns and young children who are unable to communicate, as well as bedridden adults. Furthermore, the presence of the hot melt adhesive is not a disadvantage to the patient, since it is part of the sanitary product and is not noticed by senses such as smell or touch. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] [Detailed Description of the Invention] The present invention relates to a hot melt adhesive that changes color in the presence of a solution or body fluid containing an analyte in its composition, such as, but not limited to, urine. In a preferred embodiment, the hot melt adhesive changes from white to red or pink, with the intensity of the color depending on the concentration of the analyte being analyzed.

[0024] By "analyte" is meant any biochemical compound excreted through urine that is associated with a pathology, such as nitrite, glucose, protein, and other such compounds.

[0025] "Open time" refers to the maximum time after an adhesive is applied to a first substrate that a second substrate can be effectively bonded to the first substrate.

[0026] "Substrate" means the material or material surface to which the hot melt adhesive is applied and / or with which the hot melt adhesive is in direct contact. For disposable articles for personal hygiene, i.e. diapers, a typical substrate is a polyethylene film, also referred to as the "backsheet."

[0027] "Set time" refers to the minimum time required to press two or more substrates together to obtain a strong bond. Set time is thus related to the rate at which the adhesive recovers its cohesive strength.

[0028] "Affinity for water", also known as hydrophilicity, refers to the ability to establish intermolecular bonds with water molecules. This property, typical of polar molecules, defines the attraction and interaction between different molecules and water molecules.

[0029] By "very slow color change" is meant a color transition that takes longer than 10 minutes to occur or to complete.

[0030] "Instantaneous color change" means a color transition that takes less than one minute to occur or complete.

[0031] The hot melt adhesive of the present invention is a polymer component comprising at least one thermoplastic polymer that is soluble or partially soluble in water so that urine, and thus the nitrite, can contact the reagent components; a resin component comprising at least one hydrocarbon resin; a plasticizer component comprising at least one plasticizer capable of forming a homogeneous mixture with the polymer component and having the ability to modify rheological properties such as viscosity; a surfactant component comprising at least one nonionic surfactant; A reagent component capable of reacting with the analyte to change color; an antioxidant component comprising at least one phenolic antioxidant; Includes.

[0032] Additionally, the compositions of the present invention may have other ingredients present such as, but not limited to, oils, stabilizers, pigments, dyes, antiblock additives, polymeric additives, defoamers, preservatives, thickeners, rheology modifiers, wetting agents, fillers, solvents, nucleating agents, chelating agents, gelling agents, processing aids, crosslinking agents, neutralizing agents, flame retardants, fluorescent agents, compatibilizers, antimicrobial agents, and water.

[0033] Polymer Component By "polymeric component" is meant the raw material that contributes to the main properties of the hot melt adhesive, which is considered the backbone of the composition. The remaining components of the composition of the present invention are therefore intended to improve or enhance the properties of the polymeric component.

[0034] The solubility or affinity of the hot melt adhesive to water is essential to ensure good performance. Being soluble or partially soluble allows urine to diffuse through the hot melt adhesive and thus allows contact between the analyte and the reagent components, causing the hot melt adhesive to change color. If the hot melt is insoluble or not soluble enough, the color change will not occur or will be very slow. On the other hand, if the hot melt adhesive composition is too soluble, the color change will occur instantly and the adhesive may fade, which is undesirable. In this context, a maximum of 10 minutes for the color change to occur is considered acceptable. For this reason, the solubility of the composition must be carefully fine-tuned to achieve the desired properties.

[0035] As the present invention relates to hot melt adhesives, properties such as adhesion, cohesion, open time, set time, among others, should not be overlooked, however, properties such as solubility become essential in the present invention as they directly affect the performance and stability of the adhesive.

[0036] The polymer component of the hot melt adhesive must contain at least one water-sensitive thermoplastic component, which means that the polymer must be soluble or partially soluble in water. Soluble polymers of the present invention include, but are not limited to, polyvinylpyrrolidone (PVP), polyvinylpyrrolidone / vinyl acetate copolymer (PVP / VA), polyethylene glycol (PEG), polyacrylic acid (PAA), ethylene and acrylic acid copolymer (EAA), poly(vinyl acetate) (PVA), and polyacrylamide.

[0037] The polymer component content may be up to 80% by weight of the hot melt adhesive composition.

[0038] In a preferred embodiment, when the analyte to be detected is nitrite ion, the content of the polymer component accounts for 5% to 60% by weight of the hot melt adhesive composition, preferably 10% to 50%, more preferably 20% to 40%, and even more preferably 25% to 35%.

[0039] Resin Component Solubility or affinity for water, and other body fluids such as urine, is important to ensure good performance of the products of the present invention. For this purpose, polar raw materials are generally implied.

[0040] Resins of the present invention may be selected from, but are not limited to, aliphatic hydrocarbon resins, aromatic hydrocarbon resins, aromatic modified aliphatic hydrocarbon resins, hydrogenated polycyclopentadiene resins, polycyclopentadiene resins, gum rosin, gum rosin esters, wood rosin, wood rosin esters, tall oil rosin, tall oil rosin esters, polyterpenes, aromatic modified polyterpenes, terpene phenols, aromatic modified hydrogenated polycyclopentadiene resins, hydrogenated aliphatic resins, hydrogenated aliphatic aromatic resins, hydrogenated terpenes and modified terpenes, hydrogenated rosin acids, hydrogenated rosin esters, derivatives thereof, and combinations thereof.

[0041] Although the polarity of the hydrocarbon resins is much lower compared to the alternatives, namely rosin and terpene resins, these resins are preferred for the compositions of the present invention because they have much higher stability, less odor and less color. Therefore, preferred resins for the present invention include hydrocarbon resins, more preferably aliphatic C5 resins and aromatic C9 resins, more exclusively aromatic C9 resins.

[0042] The content of the resin component accounts for up to 60% by weight of the hot melt adhesive composition.

[0043] In a preferred embodiment, when the analyte to be detected is nitrite ion, the content of the resin component occupies 5% to 40%, preferably 10% to 35%, more preferably 15% to 25% by weight of the hot melt adhesive composition.

[0044] Plasticizer component In the present invention, the plasticizer component enables dissolution of the polymer and adjustment of the viscosity and softening point of the hot melt adhesive composition to values ​​that are easily applicable to industrial lines.

[0045] "Acceptable viscosity" means that the viscosity value at 120°C is within the range of 500mPa·s to 15000mPa·s, preferably 750mPa·s to 10000mPa·s, and more preferably 1000mPa·s to 6000mPa·s. "Acceptable softening point" means that the value is within the range of 50°C to 120°C, preferably 55°C to 115°C, and more preferably 60°C to 110°C. By ensuring that the viscosity and softening point of the composition are within the aforementioned acceptable values, it is ensured that the operating temperature in the industrial line is also within the acceptable range, specifically, 70°C to 120°C, preferably 75°C to 120°C, and more preferably 80°C to 110°C.

[0046] The plasticizer component comprises at least one plasticizer that is liquid at room temperature to plasticize the polymer component before heating, thereby facilitating the dissolution of the polymer component. The plasticizer of the present invention may be selected from, but is not limited to, inorganic and organic acids. Plasticizers that are liquid at room temperature are low molecular weight substances, and as a result, may easily migrate out of the network of the hot melt adhesive, leading to changes in properties such as viscosity. For this reason, the content of the plasticizer shall be optimized to effectively plasticize the polymer without increasing the possibility of migration.

[0047] As mentioned above, polar raw materials are preferred because they provide affinity to water. In view of this, plasticizers having polar functional groups, i.e., but not limited to, organic acids, are preferred. Plasticizers suitable for the present invention may be selected from, but not limited to, saturated or unsaturated fatty acids, particularly dimeric fatty acids, polymerized fatty acids, or derivatives thereof.

[0048] The content of the plasticizer component accounts for up to 80% by weight of the hot melt adhesive composition.

[0049] In a preferred embodiment, when the analyte to be detected is nitrite ion, the content of the plasticizer component accounts for 5% to 60% by weight of the hot melt adhesive composition, preferably 10% to 50%, more preferably 25% to 45%, and even more preferably 30% to 40%.

[0050] Surfactant components The surfactant component is intended to increase the affinity of the composition to water, which means that the surfactant component contributes to the solubility of the composition. The surfactant component is composed of at least one of a nonionic surfactant, a cationic surfactant, an anionic surfactant, or an amphiphilic surfactant. The hydrophilic-lipophilic balance (HLB) of the surfactant component is within the range of 3 to 20, preferably 11 to 20, to ensure the solubility of the surfactant component.

[0051] Non-ionic surfactants are preferred in the present invention and may be selected from, but are not limited to, natural or synthetic ethoxylated alcohol and ethoxylated phenol derivatives.

[0052] The content of the surfactant component accounts for up to 30% by weight of the hot melt adhesive composition.

[0053] In a preferred embodiment, when the analyte to be detected is nitrite ion, the content of the surfactant component accounts for 0.5% to 20% by weight of the hot melt adhesive composition, preferably 1% to 15%, more preferably 2% to 10%, and even more preferably 3% to 5%.

[0054] Reagent composition The reagent components are responsible for detecting the presence of an analyte. This detection is achieved due to a chemical reaction between the reagent components and the analyte to be analyzed, resulting in a color change. Reagents suitable for the present invention include, but are not limited to, Griess-Ellosbay, Fehling, Benedict, Bradford, Bicinchoninic Acid Test Reagents, and Lewis Reagents. Reagents of any assay known in the current state of the art, as applied to the colorimetric determination of analytes present in urine, can be added to the reagent components.

[0055] In a preferred embodiment, the analyte to be detected is nitrite ion, and the reagent components are composed of the Griess-Ilosbay reagent. The Griess-Ilosbay reagent mainly includes a first reagent and a second reagent. The first reagent may be selected from, but is not limited to, N-(1-naphthyl)ethylenediamine dihydrochloride and α-naphthylamine. The second reagent may be selected from, but is not limited to, sulfanilamide, sulfanilic acid, nitroaniline, and p-aminoacetophen in phosphoric acid.

[0056] The detection of nitrite ions involves two subsequent reactions: if a second reagent is added to a solution containing nitrite, the second reagent reacts with the nitrite molecule to form a colorless diazo (R2C-N=N) complex. Such an example of a diazo complex is the nitrite-sulfanilic acid complex. Only then does the diazo complex react with the first reagent to give a red or pink precipitate. The higher the concentration of nitrite, the darker the color. This precipitate can also be called an azo dye or azo compound due to the presence of an azo group (RN=N-R') in the precipitate molecule.

[0057] [ka]

[0058] The content of the reagent component accounts for up to 20% by weight of the hot melt adhesive composition.

[0059] In a preferred embodiment, when the analyte to be detected is nitrite ion, the content of the reagent component occupies 1% to 10%, preferably 1% to 8%, and more preferably 4% to 6%.

[0060] Antioxidant ingredients The use of the antioxidant component is intended to prevent degradation of the hot melt adhesive due to excessive heat during the manufacturing process and during application and storage of disposable articles for personal hygiene to which the hot melt adhesive is applied.

[0061] The antioxidant component suitable for the present invention includes at least one primary antioxidant, secondary antioxidant, or multifunctional antioxidant, among which suitable antioxidant components may be selected from phenolic antioxidants, phosphite antioxidants, thioester antioxidants, or mixtures thereof, preferably phenolic antioxidants.

[0062] The antioxidant component may comprise up to 20% by weight of the hot melt adhesive composition.

[0063] In a preferred embodiment, when the analyte to be detected is nitrite ion, the content of the antioxidant component accounts for 0.5% to 10%, preferably 1% to 5%, and more preferably 1% to 3% by weight of the hot melt adhesive composition.

[0064] Hot melt adhesive manufacturing process Due to the light sensitive nature of the hot melt adhesive composition, preparation of the hot melt adhesive must be carried out in the absence of light to avoid photodegradation of the composition.

[0065] The first step in making a hot melt adhesive is to mix the reagent components with the plasticizer under constant stirring and slight heating (not exceeding 50°C) to encourage the incorporation of both components. Once the mixture is homogenous, the polymer component should be mixed into the previous mixture at room temperature to make a homogenous mixture. The mixture is then heated to a maximum temperature of 100°C with constant stirring until the polymer is completely dissolved and the mixture is translucent. The final step is to add the remaining components, the resin, surfactant, and antioxidant components, in no particular order. The temperature and mixing should be constant until all the components of the composition are incorporated and the mixture is homogenous.

[0066] Hot melt adhesive application process In the manufacture of an article using the hot melt adhesive of the present invention, the hot melt is applied to a back sheet. The article can be, but is not limited to, a disposable article for personal hygiene. The outside of the article is provided with a means for protecting the hot melt adhesive from light, for example, but is not limited to, an opaque, dark, easily removable label. Only after use of the article is the light protection means removed. This ensures that the hot melt adhesive is only exposed to light after use of the article, thus avoiding premature degradation and ensuring proper functionality of the hot melt adhesive.

[0067] EMBODIMENTS OF THE PRESENTINVENTION Table 1 presents suitable embodiments of the present invention. The embodiment of Example 1 relates to a hot melt adhesive composition in which the analyte to be detected is nitrite ions and the technical properties such as viscosity, softening point and color change are deemed acceptable.

[0068] [Table 1]

Claims

1. A hot melt adhesive composition for detecting an analyte in urine, comprising a polymer component, a plasticizer component, a resin component, a surfactant, an antioxidant component, and an analyte detection reagent component that is characterized by being photosensitive.

2. 2. The hot melt adhesive of claim 1, wherein the analyte is a nitrite ion.

3. 3. The hot melt adhesive of claim 1 or 2, characterized in that it comprises up to 80% by weight of the polymer component, up to 80% by weight of the plasticizer component, up to 60% by weight of the resin component, up to 30% by weight of the surfactant, up to 20% by weight of the antioxidant component, and up to 20% by weight of the analyte detection reagent component.

4. The hot melt adhesive of any one of claims 1 to 3, wherein the analyte detection reagent component is Griess-Elosbay reagent.

5. The hot melt adhesive of any one of claims 1 to 4, wherein the polymer component comprises at least one water-sensitive thermoplastic polymer.

6. The hot melt adhesive according to any one of claims 1 to 5, wherein the resin component comprises at least one hydrocarbon resin.

7. 7. The hot melt adhesive of any one of claims 1 to 6, wherein said plasticizer component comprises at least one plasticizer that is liquid at room temperature.

8. 8. The hot melt adhesive according to any one of claims 1 to 7, wherein the surfactant component comprises at least one surfactant selected from a nonionic surfactant, a cationic surfactant, an anionic surfactant, or an amphiphilic surfactant.

9. 9. The hot melt adhesive according to any one of claims 1 to 8, wherein the antioxidant component comprises at least one antioxidant selected from a primary antioxidant, a secondary antioxidant, or a multifunctional antioxidant.

10. 10. The hot melt adhesive according to any one of the preceding claims, wherein the viscosity of the hot melt adhesive at 120 ° C is comprised between 500 mPa·s and 15000 mPa·s.

11. 11. The hot melt adhesive according to any one of the preceding claims, wherein the softening point of the hot melt adhesive is comprised between 50 ° C and 120 ° C.

12. A method for producing a hot melt adhesive according to any one of claims 1 to 11, a. combining the plasticizer and the analyte detection reagent components and heating to any temperature up to 50° C.; b. adding said polymer component to the mixture obtained in the previous step at room temperature to obtain a homogenous mixture; c. heating the prepared mixture up to 100° C. with constant stirring until the polymer component dissolves in the mixture and the mixture becomes translucent; d. adding the resin component, the surfactant component, and the antioxidant component in no particular order; e. maintaining the heating and stirring of step c. until all ingredients are observed to be fully incorporated; A manufacturing method comprising the steps of:

13. The method of claim 12, further comprising providing a final step of applying the hot melt adhesive to an article.

14. 14. The process according to claim 12 or 13, which is carried out in the absence of light.

15. The method of claim 13, wherein a light protection means is applied to the article.

16. The method of claim 14, wherein the light protection means is removed from the disposable article for personal hygiene after use of the article.

17. Use of the hot melt adhesive according to any one of claims 1 to 11 in disposable articles for personal hygiene.

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