MXPA99006204A - Temperature sensitive adhesive composition - Google Patents

Abstract

A temperature-triggerable water soluble adhesive composition comprising a poly (vinyl alkyl ether), preferably poly (vinyl methyl ether) and a hydrophobic polymer, preferably a hydrophobic polystyrene resin or an acrylate. The adhesive composition of the present invention retains its integrity at fluid temperatures above approximately 33°C, but is water soluble at fluid temperatures below approximately 22°C. The adhesive composition of the present invention may be disposed of by flushing in a conventional toilet.

Description

ADHESIVE COMPOSITION SENSITIVE TO TEMPERATURE TECHNICAL FIELD The present invention relates to a disposable adhesive composition with discharge of water that can be discarded by a sudden discharge of water in a conventional retret. More particularly, the temperature-releasable water soluble adhesive composition comprises poly (vinyl alkyl ether), preferably poly (vinyl methyl ether) and a hydrophobic polymer, preferably a hydrophobic polystyrene resin or an acrylate. The adhesive composition of the present invention retains its integrity at fluid temperatures above about 33 ° C, but fluid temperatures below about 22 ° C are soluble in water.

BACKGROUND OF THE INVENTION The term "adhesive" as used herein encompasses the term adhesive in its accepted uses in the art. For example, the term "adhesive" includes but is not limited to the material that causes a surface to adhere to another similar or non-similar surface.

The term "disposable water discharge" as used herein means being able to be discharged with water discharge in a conventional toilet and introduced into a conventional sewer system such as a municipal sewage system, a tank system septic industry and a residential septic tank system without causing an obstruction or blockage of the conventional sewer system or conventional toilet.

The term "disposable adhesive with water discharge" as used herein means a water-soluble adhesive releasable at the temperature of the present invention.

The term "disposable product with water discharge" as used herein refers to products that comprise contain the disposable adhesive with water discharge of the present invention and include, but are not limited to, adhesives, tapes, labels, sheets , the papers, the tissues, the structural members, the nonwoven fabric articles, the woven fabric articles and combinations thereof. Disposable items with water discharge include, but are not limited to, infant care items such as diapers, protectors, bibs and cleaners; child care items such as underpants, protectors, bibs and cleaners; adult care items such as diapers and incontinence pads; articles for the care of women such as pads and tampons; items for medical care such as bed covers, wound dressings, osteone bags, cleansers, gowns; articles for surgical care such as table tops, drapes, wound dressings and gowns; household items such as cleaners, isolation; and packaging materials.

The term "water dispersible" as used herein means an adhesive film which, when exposed to fluid at a temperature of about 22 ° C, for about 2 minutes, dissolves or breaks up into small pieces all of which pass. through a rack of 20 mall.

The term "water-disintegrable" as used herein means an adhesive film which, when a fluid is exposed to a temperature of about 22 ° C, for about 2 minutes, disintegrates or fragments into pieces some of which pass through. through a 20 mesh grid.

The term "weakened with water" as used herein means an adhesive film which, when exposed to fluid at a temperature of about 22 ° C for about 5 minutes, loses stiffness and will bend without the application of an external force when the film is held horizontally from a corner.

The term "stable in water" as used herein means an adhesive film which, when exposed to fluid at a temperature of about 22 ° C or about 5 minutes, is not water dispersible, water-disintegrable or weak in water. Water.

The term "water-soluble" as used herein means an adhesive which is dispersible in water disintegrable in water in the presence of the fluid having a temperature of about 22 ° C such as the water temperature of the tap normally present in a water. conventional retret cup.

The term "water-insoluble" as used herein means an adhesive which is stable in water in the presence of the fluid having a temperature of about 33 ° such as the temperature of the waste fluids of the body.

The term "trigger temperature" as used herein means that the water solubility of an adhesive depends on the temperature. More particularly, the term "disparabl with temperature" means that the disposable water-discharging adhesive of the present invention is insoluble in water at or above the temperature of about 33 ° C and is soluble in water at or below the temperature of Approximately 22 ° C. The approximate term as used herein with respect to temperature includes temperatures within two degrees of the declared temperature.

Disposable products which are easily usable, relatively cheap and sanitary are of great convenience. However, since the closure of the landfills with solid waste prevents them from being thrown away and clean air standards preclude incineration, the disposal of these products has become a problem. An alternative to throwing it in landfills and incineration is the use of disposable water discharge products which can be discarded by disposing of them in a conventional toilet in a conventional sewer system. To be disposable co-discharge of water, a product must meet two criteria. First, it must have a sufficient wet strength for its intended use. Second, it must be soluble in water in contact with the water in the toilet bowl.

One approach to producing a disposable product with water discharge is to limit the size of the product so that it will pass through the pipe if it causes blockages. Such products have a high wet strength but do not disintegrate upon contact with tap water at the toilet rate. A second approach to producing a disposable product with water discharge is to produce a product which is not soluble in itself but which disintegrates upon contact with acidic or alkaline aqueous solutions or in the presence of specific enzymes. . Such products have a high resistance to wetting, but require the addition of an acidic, alkaline or enzymatic material to allow their disposal in a conventional sewer system. A third approach to producing a disposable product with water discharge is to adhere a product together with a salt sensitive adhesive. However, some salt sensitive adhesives are precipitated in the presence of high concentrations of calcium ion. Since the calcium content of the tap water varies tremendously between geographic locations (982-1983 Metropolitan Water Supply Analysis) in places that have high calcium content, the products produced using calcium adhesives may not be disposable with water discharge in fact. For a disposable adhesive with useful discharge, the used adhesive must be disposable in tap water or any other geographical location so that the disposable product with water discharge disintegrates or disperses on contact with water contact. the key.

However, even if a disposable adhesive co discharges water and a disposable product with water discharge containing the disposable adhesive with discharges of water or soluble in water in any geographical location, to make the disposable product with water discharge useful it must also have a resistance to wet Enough for your intended use. The resistance to wetting sufficient for its intended use and the dispersion or disintegration in contact with the toilet bowl water is particularly difficult to achieve for adhesives in disposable products designed to make contact with body fluids. This difficulty results in the similarity of the composition of body fluids and tap water. This is illustrated in Table 1 which compares the pH and the ionic composition of the fluid urine of the body and water of the tap.

However, there is a distinctive difference between the temperature of body fluids and that of tap water. For example, the temperature of the skin within the area covered by the disposable diapers varies approximately 34.3 ° C (Jordan, WE and Bailey TL 1982, "Factors that Influence Infants' Diaper Dermatitis" in Neonatal Skin, H. Mibach and K. Boisitis, Marcel Dekker Editions, Inc., New York), while the water temperature of the toilet bowl is approximately 20 ° C-25 ° C. This temperature difference between the waste fluids of the body and the toilet bowl rim provides an opportunity to exploit the temperature as a trigger where the adhesive is insoluble in water at one temperature and soluble in water at another temperature. Such water-soluble adhesive can be used alone or as a means to adhere a substrate to another similar or different substrate. Such a disposable adhesive with water discharge will allow a disposable product with water discharge to disperse or disintegrate its component parts, each of which can be discarded in the most environmentally efficient and cost-effective manner.

Therefore, what is required is a water-soluble, non-toxic, non-toxic adhesive which has sufficient wet strength for use at a temperature and which is soluble in water at other temperatures. This is a disposable adhesive with water discharge which is insoluble in water at the temperature of the body waste fluids, but which is soluble in water at the temperature of the normal tap water and, therefore, disposable with water discharge. water in conventional sewer systems.

SYNTHESIS OF THE INVENTION The disposable water-discharge adhesive of the present invention comprises a water soluble polymer that can be triggered with temperature, wherein the polymer is poly (vinyl alkyl ether), preferably a poly (vinyl methyl ether) (PVME) obtained as Amobond (Amoco Chemical Company) and a means for altering the temperature at which the water soluble poly (vinyl methyl ether), the media comprising a hydrophobic polymer, preferably a polystyrene or acrylate resin, combined with the poly (vinyl methyl ether) in a sufficient amount to make the water-insoluble poly (vinyl methyl ether and hydrophobic polymer) in the presence of the fluid having a temperature above about 33 ° C, but soluble in water in the presence of the fluid having a temperature below about 22 ° C. The disposable adhesive composition with water discharge of the present invention was used alone and to adhere a substrate to another similar substrate not s imilar Therefore, it is an object of the present invention to provide a disposable adhesive with discharge of water which is insoluble in water in fluid having a temperature above about 33 ° C, but which is soluble in water in a fluid having a temperature below about 22 ° C.

It is another object of the present invention to provide a disposable adhesive with discharge of water that disintegrates in the water of the tap regardless of the geographical variations in the concentration of water salt of the tap.

It is another object of the present invention to provide a disposable adhesive with water discharge that is non-toxic and non-irritating to the skin.

It is another object of the present invention to provide a permanent adhesive which is converted to a removable adhesive by a change in the fluid temperature at which the adhesive is exposed.

It is another object of the present invention to provide an adhesive which retains satisfactory adhesive properties in the presence of changes in the environmental humidity.

It is another object of the present invention to provide a disposable adhesive with discharge of water as a part of the disposable product that can be disposed of in a toilet *.

It is another object of the present invention to provide a disposable adhesive with discharge of water as a part of a disposable product which can be discarded by discharging water into a toilet without the addition of chemical solvents.

It is another object of the present invention to provide a disposable water discharge adhesive for use in infant care articles.

It is another object of the present invention to provide a disposable water discharge adhesive for use in child care articles.

It is another object of the present invention to provide a disposable adhesive with water discharge for use in adult care articles.

It is another object of the present invention to provide a disposable water discharge adhesive for use in women's care articles.

It is another object of the present invention to provide a disposable water discharge adhesive for use in medical care articles.

It is another object of the present invention to provide a disposable water discharge adhesive for use in surgical care articles.

It is another object of the present invention to provide a disposable adhesive with water discharge for use in household articles.

It is another object of the present invention to provide a disposable adhesive with water discharge for use in insulation.

It is another object of the present invention to provide a disposable adhesive with water discharge for use in packaging material.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows the water intake of films prepared from 100% poly (vinyl methyl ether), 75% poly (vinyl methyl ether) + 25% Piccotex-100 and 50% poly (vinyl methyl ether) + 50% Piccotex after 1, 4, 9 and 1 minutes of exposure to water at 20 ° C.

Figure 2 shows the water intake of film prepared from 100% poly (vinyl methyl ether), 75% poly (vinyl methyl ether) + 25% Piccotex-100 and from 50% poly (vinyl methyl ether) ) + 50% Piccotex after 1, 4, 9, and 1 minutes of exposure to synthetic urine at 35 ° C.

Figure 3 shows the water intake of film prepared from 75% poly (vinyl methyl ether) + 25% Kristale 5140 after 1, 4, 9 and 16 minutes of exposure to water at 20 ° to water at 35 ° C and synthetic urine at 35 ° C.

Figure 4 shows the water intake of films prepared from 100% poly (vinyl methyl ether) after 1, 4, 9, and 16 minutes of exposure to water at 20 ° C, to water at 35 ° C and to synthetic urine at 35 ° C.

DETAILED DESCRIPTION OF THE INVENTION The releasable water soluble adhesive with temperature of the present invention comprises two components.

The first component is poly (vinyl alkyl ether), preferably poly (vinyl methyl ether) (PVME). The second component is a hydrophobic polymer, preferably a hydrophobic polystyrene resin or an acrylate.

The poly (vinyl methyl ether) for use in this invention is a polymer which is soluble in water below 33 ° C to 35 ° C and insoluble in water above 33 ° -35 ° C which is the turbidity point temperature (TLCST ) for poly (vinyl methyl ether). The closeness of the poly (vinyl methyl ether) cloud point temperature to the waste fluid temperature of the body makes the poly (vinyl methyl ether) not suitable for use as an adhesive in the disposable products designed to make contact with the body of a human or animal. In addition, poly (vinyl methyl ether) is characterized by a low glass transition temperature (Tg) of -21 ° C and therefore a pronounced tendency to "cold flow". That is, poly (vinyl methyl ether) tends to flow out of the storage site at storage at or below room temperature. This tendency to "cold fluid" makes poly (vinyl methyl ether) unsuitable for use as an adhesive in products which must be stored for a period of time.

To use poly (vinyl methyl ether) as a water soluble adhesive triggerable with temperature either sol in disposable products with water discharge intended to make contact with the body of a human of an animal, and necessary to reduce its solubility in the fluid at a temperature of 33 ° -35 ° C without significantly reducing its solubility in fluids at 22 ° C.

The hydrophobic polymers for use in this invention are more insensitive to water than poly (vinyl methylether) and are characterized by positive glass transition temperatures or preferably between about 50 ° C and 95 ° C, more preferably between about 55 ° C and 92 ° C, and more preferably between about 60 ° and 91 ° C. As expected, when a hydrophobic polymer is mixed with poly (vinyl methyl ether), the composition is less sensitive to high above 33 ° C than poly (vinyl methyl ether) alone. However, totally unexpected, when a hydrophobic polymer is mixed with poly (vinyl methyl ether), the composition is more sensitive to water below 22 ° C than poly (vinyl methyl ether) alone. That is, mixtures of poly (vinyl methyl ether) and a hydrophobic polymer are more inert to fluids at 33 ° C than poly (vinyl methyl ether) alone and therefore provide greater wet strength than poly (vinyl methyl) ether) alone. Even more importantly, mixtures of poly (vinyl methyl ether) and hydrophobic polymer absorb water faster at 22 ° C than poly (vinyl methyl ether) alone and therefore provide a more disposable adhesive with water discharge than water. poly (vinyl methyl ether) alone. In addition, the disposable water-discharge adhesive of the present invention comprising poly (vinyl methyl ether) and a hydrophobic polymer is characterized by an increase in the glass transition temperature over that of poly (vinyl methyl ether) alone and a decrease in the "cold flow" over that of poly (vinyl methyl ether) alone. This increase in glass transition temperature and decrease in "cold flow" makes the disposable adhesive with hydrophobic water discharge of poly (vinyl methyl ether) of the present invention a sensitive disposable adhesive with unexpectedly superior water discharge.

The poly (vinyl methyl ether) for use in the present invention can be amorphous or isotactic. The poly (viny methyl ether) preferably has an average molecular weight of 40,000 to 300,000 Daltons, more preferably an average molecular weight of 80,000 to 200,000 Daltons and more preferably an average molecular weight of 120,000 to 160,000 Daltons . Preferably, the poly (vinyl methyl ether) comprises between about 10% and 90% by weight (grams / 10 grams), more preferably about 25% and 80% po weight and more preferably between about 50% and 75% po weight of the water soluble adhesive composition and trigger temperature of the present invention.

Hydrophobic polymers for use in the present invention include, but are not limited to, polystyrene and acrylate copolymers. Polystyrene copolymers include, but are not limited to a polystyrene oligomer ta such as Piccolastic D150 (ex Hercules, Inc.), a styrene-alpha-methyl such as Kristalex 3100 (ex Hercules, Inc.), or Resin Amoco 18- 290 (by Amoco Chemical Co.), an aromatic copolymer ta such as Kristalex 5140 (ex Hercules, Inc.), a phenol terpene such as Piccofyn A135 (ex Hercules, Inc.), a poly (vinyl toluene-co-alpha methyl) copolymer styrene) such as Piccotex 100 (d Hercules, Inc.), and a polymerized resin pentaerythritol ester such as Pentalyn C (ex Hercules, Inc.). Preferably, the hydrophobic polystyrene resin comprises about 10% and 90% by weight (grams / 100 grams) more preferably between about 20% and 75% by weight and more preferably between about 25 and 50% by weight of the disposable adhesive with water discharge of the present invention. The acrylates include, but are not limited to, poly (heptyl acrylate-co-methacrylic acid) copolymer such as ASE-75 (from Rohm &Haas) and a crosslinked poly (ethyl acrylate-co-methacrylic acid) copolymer such as ASE-60 (d Rohm &Haas). Preferably, the acrylate comprises between about 20% and 65% by weight (grams / 100 grams) more preferably between about 25% and 55% by weight and more preferably between about 40% and 50% by weight of the disposable adhesive with discharge of water of the present invention.

The disposable water-discharge adhesive of the present invention may contain the optional non-hydrophilic additives including, but not limited to antioxidants, pigments and dyes.

The disposable water discharge adhesive of the present invention can be used alone or can be applied to the substrate including, but not limited to, the tape, the film, the paper, the structural elements, the woven fabric, the non-woven fabric already woven combinations thereof. Methods for applying the disposable adhesive with water discharge of the present invention to a substrate include, but are not limited to, rolling, embedding, stippling, and printing, extrusion, spraying, and other methods known to those skilled in the art.

The disposable water discharge adhesive of the present invention is prepared by mixing the poly (vinyl methyl ether) and a hydrophobic polymer until a homogeneous mixture is obtained using any of the methods known in the art. Such methods include, but are not limited to mixing a solution of poly (vinyl methyl ether) and a solution of the hydrophobic polymer in a common solvent and evaporating the solvent or mixing with hot melt the poly (vinyl methyl ether) and the hydrophobic polymer. The hot melt method used can be any of the methods known to those skilled in the art. It is understood that the precise temperature to be used in the hot melt method will depend on the melting point of poly (vinyl methyl ether) and the hydrophobic polymer.

The following examples illustrate a variety of disposable water discharge adhesives that may be made within the scope of the present invention.

EXAMPLE 1 - FLUID TAKE The fluid intake is used to evaluate the operation of the disposable adhesive with water discharge of the present invention. The fluid intake is important because the disposable water discharge adhesive of the present invention must be insoluble in water in the presence of fluid having a temperature above about 33 ° C, per soluble in water in the presence of fluid having a temperature below about 22 ° C.

To measure the fluid intake, the half-inch squares of adhesive film were weighed and submerged in water at 22 ° C and 35 ° C and in synthetic urine at 35 ° C for 1, 4, 9 16 minutes The weight gain was measured and fluid intake s defined [final weight - initial weight] / initial weight.

The poly (vinyl methyl ether) -adhesive film was prepared by dissolving 100% by weight of poly (vinyl methyl ether) having a number average molecular weight of 122.00 Daltons in ethyl acetate. The dissolved poly (vinyl methyl ether) was poured into a silicone rubber mold, the solvent was allowed to evaporate for 3 days at room temperature and the film was pressed at 150 ° F for 5 minutes. The resulting film is a smooth, uniform and bubble-free film.

POLY MIXTURES (METHYL ETHER VINYL) + PICCOTEX 100 Adhesive films are prepared by dissolving 75 by weight of poly (vinyl methyl ether) having a number average molecular weight of 122,000 Daltons in ethyl acetate and 25% by weight of Piccotex 100 in ethyl acetate and by dissolving 50 by weight of poly (vinyl methyl ether) having a number average molecular weight of 122,000 Daltons in ethyl acetate and 50% by weight of Piccotex 100 in ethyl acetate. The dissolved poly (vinyl methyl ether) and the Piccotex 100 dissolved are mixed for homogeneity. The mixtures of poly (vinyl methyl ether) -Piccotex 100 are poured into a silicone rubber mold, the solvent is left to evaporate for 3 days at room temperature and the films are pressed at 150 ° F for 5 minutes. The resulting films are 0.43 millimeters thick, bubble-free, smooth uniforms.

Figure 1 shows the water intake of a 100% poly (vinyl methyl ether) film, a 75 film of poly (vinyl methyl ether) + 25% Piccotex 100, and a 50% poly (vinyl) film methyl ether) + 50% of Piccotex 100 after d 1, 4, 9 and 16 minutes of immersion in water at 22 ° C.

Figure 2 shows the water intake of a film of 100% poly (vinyl methyl ether), a film of 75 poly (vinyl methyl ether) + 25% Piccotex-100 and a film of 50% poly (vinyl methyl ether) + 50% Piccotex-100, after d 1, 4, 9, and 16 minutes of immersion in synthetic urine at 35 ° C.

These data show that the adhesive films prepared from the mixtures of 25% and 50% of the hydrophobic polystyrene resin Piccotex 100 with 50% and 75% poly (vinyl methyl ether) shows an increase in fluid intake at 22 ° C and a reduction of fluid intake at 35 ° C over that of 100% poly (vinyl methyl ether) alone.

POLY MIXTURES (METHYL ETHER VINYL) + KRISTALEX 5140 - An adhesive film was prepared by dissolving 75% by weight poly (vinyl methyl ether) in ethyl acetate and 25% by weight d Kristalex 5140 in ethyl acetate. The dissolved poly (vinyl methyl ether) and the dissolved Kristalex 5140 are mixed for homogeneity. The mixture of poly (vinyl methyl ether) + Kristale 5140 was poured into a silicone rubber mold, the solvent allowed to evaporate for 3 days at room temperature and the films were pressed at 150 ° F for 5 minutes. The resulting films were 0.43 millimeters thick, free of bubbles, uniform and smooth.

Figure 3 shows the fluid intake of an adhesive film of 100% poly (vinyl methyl ether) after d 1, 4, 9 and 16 minutes of immersion in water at 20 ° C and after 1, 4, 9 and 16 minutes immersion in water or synthetic urine ° C.

Figure 4 shows the fluid intake of the adhesive film of 75% poly (vinyl methyl ether) + 25% d Kristalex 5140 after immersion of 1, 4, 9, and 16 minutes in water at 20 ° C, and after immersion in water in 1, 4, 9 16 minutes or in synthetic urine at 35 ° C.

These data show that the mixing of 25% d Kristalex 5140 hydrophobic polystyrene resin with 75% d poly (vinyl methyl ether) increased the fluid intake at 20 ° C-22 ° C reduced the fluid intake at 35 ° C on that of 100% d poly (vinyl methyl ether) alone.

EXAMPLE 2 - FLUID COLLECTION Adhesive films are prepared by mixing 50% to 100% by weight of poly (vinyl methyl ether) and de disd % to 50% by weight of the hydrophobic polystyrene resins Piccotex 100, Piccolastic D150 and Amoco Resin 18-290 and heating the mixture in a Haake Rheomix 600 at a temperature at which they are a flowable fluid (200 ° C to 300 ° C). Each hot mix of hydrophobic polystyrene-poly (vinyl methyl ether) resin is mixed for approximately 10 minutes until homogeneous, filtered if necessary, cooled and pressed with a 0.13 millimeter plate into a Dake press to form a movie. Each film is tested for sensitivity to water at 22 ° C and 35 ° C and for sensitivity to urine at 35 ° C.

Table 2 compares the percent fluid intake of 100% of the poly (vinyl methyl ether) adhesive film with the fluid intake of the hydrophobic polystyrene-poly (vinyl methyl ether) resin adhesive films after minutes of immersion in water at 22 ° C and 35 ° C and in synthetic urine at 35 ° C.

Table 2% D? TOMA (9 Minute Immersion) P-100 Piccotex 100 PS = Piccolastic D150 Amoco = Resin Amoco 18-290 These data show that the adhesive films prepared by mixing 25% to 50% hydrophobic polystyrene resins Piccotex 100, Piccolastic D150 and Resin Amoco 18-290 with 50% to 75% poly (vinyl methyl ether) show a fluid intake reduced at 35 ° C and a fluid intake increased 22 ° C over that of the adhesive films prepared from 100 poly (vinyl methyl ether).

Examples 1 and 2 demonstrate that disposable water-discharge adhesives of the present invention comprising poly (vinyl methyl ether) and a hydrophobic polystyrene resin take less fluid 35 ° C than poly (vinyl methyl ether) alone and absorb more fluid at 22 ° C than poly (vinyl methyl ether) alone. These unexpected results show that the adhesive composition of the present invention has both a greater resistance to wet at 35 ° C than poly (vinyl methyl ether) alone and a greater solubility in water at 22 ° C than poly (vinyl methyl ether) alone.

EXAMPLE 3 - GLASS TRANSITION TEMPERATURE The glass transition temperature (Tg) is the temperature at which the polymer changes from its glass type state to a rubber type state due to the increased molecular movement. The glass transition temperature of a polymer mixture is an indicator of the miscibility of the polymers in the mixture. The transition temperature of the vidri is determined by the change of step in the temperature against the heat capacity measured using TA 2910 d differential scanning calorimetry instruments. The transition temperature of the glass is chosen as the midpoint of the change in heat capacity at a heating rate of 20 ° per minute.

Table 3A shows the transition temperature of the poly (vinyl methyl ether) glass, the transition temperatures of the glass of the hydrophobic polystyrene resins Piccolastic D150, Krisstalex 5140, Piccotex 100 and the transition temperature of the acrylate glass ASE-60 . Figure 3 shows the glass transition temperatures of the 50% and 75% poly (vinyl methyl ether) blend with 25% and 50% of Piccolastic D150, Kristalex 5140, Piccotex 100, Pentalyn C and ASE-60.

Table 3A Table 3B * The transition temperatures of the Tgs glass are + 1 ° C Table 3A and Table 3B show that by mixing the poly (vinyl methyl ether) with the representative hydrophobic polystyrene resins Piccolastic D150, Kristalex 5140, Piccotex 100 and the transition temperature of the glass with the representative acrylate ASE-60 raises the transition temperature of the glass of the poly (vinyl methyl ether) and lowers the transition temperatures of the glass of the representative hydrophobic polystyrene resins and of the representative acrylic to a Transition temperature value of the single glass between that of the representative hydrophobic polystyrene resins and those of the representative acrylic used. In addition, the increase in glass transition temperatures of the mixtures of hydrophobic polystyrene resin + poly (vinyl methyl ether) and mixtures of poly (vinyl methyl ether) + acrylate over those of 100% poly (vinyl methyl ether) ) indicates that mixtures have less of a tendency to "cold flow" than poly (vinyl methyl ether) alone.

EXAMPLE 4 - DISSEMINATION The diffusion test is used to determine the effect of water vapor on the disposable water discharge adhesive of the present invention. This is important because the disposable adhesive with water discharge and the products containing the disposable adhesive with water discharge must be stored, shipped and used in various humidities.

For a measured diffusion, the half-inch squares of a film of the disposable water-discharge adhesive of the present invention are placed in a desiccator at high humidity for 7 days. Humidity is created by placing a K2S04 solution in the desiccant which gives a relative humidity of 97% at room temperature. The weight gain is measured periodically and R (t) was calculated, plotted against the square root of time and the tilt K s found through a regression. The diffusion coefficient D is calculated using the equation D = 7t / 16 * K2 * d2, where d is the film thickness.

Adhesive films are prepared from 100 poly (vinyl methyl ether) and from 50% and 75% poly (vinyl methyl ether) blends with 25% and 50% of a representative hydrophobic polystyrene resin according to the method of examples 1 and 2. The films of poly (vinyl methyl ether) + acrylate adhesives are prepared by dissolving 50 by weight poly (vinyl methyl ether) in tetrahydrofuran (THF) by dissolving 50% by weight of the acrylates. representative ASE-60 and ASE-75 in tetrahydrofuran. The dissolved poly (vinyl methyl ether) and the dissolved ASE-60 or ASE-75 are mixed for homogeneity. The mixtures of poly (vinyl methyl ether) -ASE-60 and poly (vinyl methyl ether) -ASE-75 are poured and molds of silicone rubber, the solvent is allowed to evaporate for 3 days at room temperature and the films are pressed at 150 ° for 5 minutes and at room temperature for 12 additional hours.

Table 3 compares the diffusion of 100% poly (vinyl methyl ether) films to films prepared from 50% to 75% poly (vinyl methyl ether) blends and from 25% to 50% representative hydrophobic polystyrene resins and acrylates.

TABLE 4 DIFFUSION DATA * Either the metal is probably not exact because it became a gel after three days.

The data shows that the adhesive films prepared from the 25% and 50% poly (vinyl methyl ether) blends and from 25% and 50% of the representative hydrophobic polystyrene resin and the representative acrylate show a reduced diffusion over the adhesive films prepared from 100% poly (vinyl methyl ether) after 7 days at 97% humidity.

The disposable water-discharge adhesives of the present invention provide a wet strength sufficient for intended use at the temperature of body fluids, but disintegrable and dispersible at the temperature of the tap water. The disposable water-discharge adhesives of the present invention have glass transition temperatures at which the "cold flow" in the adhesive tending to flow out of the bond site on storage will not result. The disposable adhesives with water discharge of the present invention have diffusion coefficients which allow them to maintain their integrity at high humidity and which allow them to be stored, shipped used in different humidities.

The disposable water-discharging adhesives of the present invention can be used alone, in product composed entirely of disposable components with water discharge and in products composed of disposable components with water discharge and non-disposable with water discharge. In the first case the complete product disintegrates or disperses in the normal tap water, while in the latter case the disposable components with discharged water disintegrate disperse in normal tap water and the disposable item with water discharge it is separated into pieces small enough to be discharged with water discharge into a conventional sewage system without causing an obstruction.

It will be understood that in light of the description of the present invention, modifications and improvements thereof will be apparent to those skilled in the art and that all such obvious variations are contemplated within the scope of the appended claims.

Claims (12)

R E I V I N D I C A C I O N S

1. An adhesive composition comprising: a water-soluble polymer sensitive to temperature, wherein the polymer is poly (vinyl methyl ether) (PVME) and means for altering the temperature at which the poly (vinyl methyl ether) is soluble in water, the media comprising a hydrophobic polymer mixed with the poly (vinyl methyl ether) in an amount sufficient to make the poly ( vinyl methyl ether) mixed and the hydrophobic polymer insoluble in water in the presence of the fluid having a temperature of about 33 ° and soluble in water in the presence of the fluid having a temperature below about 22 ° C.

2. The adhesive composition, as claimed in clause 1, characterized in that the hydrophobic polymer is a hydrophobic polystyrene resin.

3. The adhesive composition, as claimed in clause 2, characterized in that the hydrophobic polystyrene resin is selected from the group consisting of a polystyrene oligomer, an alpha-methyl styrene oligomer, an aromatic hydrocarbon resin, a phenol terpene resin , a copolymer of poly (vinyl toluene-co-alpha methyl styrene) and a pentaerythritol ester of polymerized resin.

4. The adhesive composition, as claimed in clause 3, characterized in that the hydrophobic polystyrene resin is an aromatic hydrocarbon resin.

5. The adhesive composition, as claimed in clause 3, characterized in that the hydrophobic polystyrene resin is a copolymer of poly (vinyl toluene-co-alpha methyl styrene).

6. The adhesive composition, as claimed in clause 3, characterized in that the hydrophobic polystyrene resin is pentaerythritol ester polymerized resin.

7. The adhesive composition, as claimed in clause 1, characterized in that the hydrophobic polymer is an acrylate.

8. The adhesive composition, as claimed in clause 7, characterized in that the acrylate is selected from the group consisting of a copolymer poly (ethyl acrylate-co-methacrylic acid) and a copolymer of poly (ethyl acrylate-co-acid) methacrylic) cross-linked.

9. The adhesive composition, as claimed in clause 8, characterized in that the acrylate is a poly (ethyl acrylate-co-methacrylic acid) copolymer crosslinked.

10. The adhesive composition, as claimed in clause 1, characterized in that the adhesive composition comprises 50% or more by weight of the poly (vinyl methyl ether).

11. The adhesive composition, as claimed in clause 1, characterized in that said adhesive composition comprises 50% or less by weight of the hydrophobic polymer.

12. An adhesive composition comprising 50% more by weight of poly (vinyl methyl ether) and 50% or less of hydrophobic polymer selected from the group consisting of a hydrophobic polystyrene resin and an acrylate mixed with poly (vinyl methyl ether), the combined poly (vinyl methyl ether) and the hydrophobic polymer being insoluble in water in the presence of fluid having a temperature above about 33 ° C and being soluble in water in the presence of the fluid having a temperature below about 22 ° C. E S U M E N A water soluble tackifiable adhesive composition comprising a poly (vinyl alkyl ether), preferably a poly (vinyl methyl ether) and a hydrophobic polymer, preferably a hydrophobic polystyrene resin or an acrylate. The adhesive composition of the present invention retains its integrity at temperatures d fluid above about 33 ° C, but is soluble in water at fluid temperatures below about 22 ° C. The adhesive composition of the present invention can be discharged by discharging water in a conventional toilet.