KR20000005459A - Oil-resistant disposable absorbent product - Google Patents

Abstract

PURPOSE: An adhesive representing a flowing and a processing properties is provided to be suitable to be used in an elastic composite and a disposable absorbent product while containing an effective oil-resistant combination. CONSTITUTION: Disclosed is an adhesive that exhibits desired oil-resistance and processing properties. The adhesive is suitable for use in elastic composites and disposable absorbent products. In one embodiment, the adhesive exhibits the following properties; an Elastic Modulus value that is greaterr than about 4 x 105 dynes per square centimeter at 40°C across the frequency range of about 0.1 to about 100 radians per second; and Elastic Modulus in Oil value that is greaterr than about 4 x 105 dynes per square centimeter at 40°C across the frequency range of about 0.1 to about 100 radians per second; a Viscosity value of less than about 40,000 centipoise at a temperature of about 275 °F; and a Viscosity value of greater than about 60,000 centipoise at a temperature of about 250 °F.

Description

Oil-resistant disposable absorbent article

Background of the Invention

It is generally known to use adhesive materials in disposable absorbent personal care products. Such adhesive materials are commonly used to attach different parts of the product to one another or to keep certain parts in the required position in absorbent articles such as diapers, training pants, adult incontinence products and women's protective articles.

Disposable absorbent articles are generally designed to be contaminated with water, saline, and various liquids such as bodily fluids such as urine, menstrual fluid, and blood during use. Obviously, disposable absorbent articles are required to maintain their integrity during use and not to allow the leakage of such liquids that may stain the product. As such, the adhesive materials used in disposable absorbent personal care articles are generally hardly affected by such liquids so as to substantially lose their adhesive properties during use by the wearer.

By the way, in addition to such liquids, disposable absorbent articles may also be contaminated with oil-based solvents such as infant oils, lotions, ointments, petrolatum, sunscreens or other skin care products. Unfortunately, current adhesive materials used in disposable absorbent articles are hardly resistant to such oil-based solvents, and these disposable absorbent articles exhibit their adhesive properties when contaminated by such oil-based solvents during use by the wearer. It was found to be almost lost. This typically detaches the various parts of the disposable absorbent article from one another and / or increases the incidence of liquid leakage.

For example, a composite comprising an elastic seal sandwiched between two substrates can be used in a disposable absorbent article to improve suitability and comfort for the wearer or to reduce the incidence of leakage to improve the absorbent properties of the disposable absorbent article. have. Adhesives used to make such composites generally must not only properly maintain the elastic seal between the two substrates, but also prevent the elastic seal from delaminating from the substrate during use. If this adhesive is not oil resistant and the elastic composite is contaminated with an oily solvent, the elastic seal can be layered away from the substrate, resulting in an increase in liquid leakage as well as a decrease in fit and comfort for the wearer.

Therefore, it is generally required to develop adhesives that are easy to process so that they can be efficiently used in the production of elastic composite materials or disposable absorbent articles while having oil resistance. Thus, such an elastic composite or disposable absorbent article will be able to better maintain its integrity when in contact with an oily solvent while in use by the wearer.

Summary of the Invention

One aspect of the present invention relates to an adhesive that is substantially resistant to oil-based solvents and is easy to process.

Adhesive according to an embodiment of the present invention has the following characteristics.

a) an elastic modulus value of at least about 4 × 10 ⁵ dyne / cm ² at a frequency range of about 0.1 to about 100 rad / sec at 40 ° C .;

b) an elastic modulus value in oil of at least about 4 × 10 ⁵ dyne / cm ² over a frequency range of about 0.1 to about 100 rad / sec at 40 ° C .;

c) a viscosity value of about 40,000 cp or less at a temperature of about 135 ° C. (275 ° F.); And

d) A viscosity value of at least about 60,000 cp at a temperature of about 121 ° C (250 ° F).

Another aspect of the present invention relates to an elastic composite material wherein an elastic seal is positioned between a first substrate and a second substrate, and the first substrate is attached to the second substrate by an adhesive exhibiting the required properties described in the present invention. . This elastic composite is suitable for use in disposable absorbent articles.

In an elastic composite material according to an embodiment of the present invention, an elastic seal is positioned between a first substrate and a second substrate, and the first substrate is attached to the second substrate by an adhesive that exhibits the required characteristics of the present invention.

In another aspect, a disposable absorbent article is preferably provided, such as a baby diaper, having substantial oil resistance such that the disposable absorbent article is substantially intact when in contact with an oily solvent while in use by the wearer.

According to one embodiment, the above object consists of a surface sheet, a back sheet attached to the surface sheet, an absorbent structure positioned between the surface sheet and the back sheet, and an elastic composite material attached to the surface sheet. This elastic composite is achieved in a disposable absorbent article in which an elastic seal is positioned between the first substrate and the second substrate and the first substrate is attached to the second substrate by an adhesive that exhibits the desired properties of the present invention.

The present invention relates to adhesives suitable for use in elastic composites and disposable absorbent articles contaminated by solvents, including oil. More specifically, the present invention relates to adhesives exhibiting the flow and processing properties required to provide effective oil resistant bonds.

Adhesives useful in the present invention are basically required to be unaffected when contacted with oil-based solvents. Such adhesives substantially retain their adhesion when contacted or otherwise exposed to the oil-based solvents described above.

As used herein, the term "adhesiveness" refers to the properties of certain materials that bond substrates together by surface attachment. This bonding is effected by the application of pressure in the case of a pressure sensitive adhesive material and by a sufficient high temperature in the case of a hot melt adhesive to contact and bond the adhesive material to the substrate.

Advantageously, adhesives useful in the present invention are almost insoluble and non-dispersible in liquid or oil based solvents in contact with the composites or disposable absorbent articles comprising the adhesive. Such liquids include water, 0.9% by weight saline solution, synthetic urine, and body fluids such as urine, menstrual fluid and blood. Such oil-based solvents include infant oils, lotions, ointments, petrolatum, sunscreens or other skin care products. Since the adhesive useful in the present invention is almost insoluble and non-dispersible in the liquid or solvent in contact with the adhesive, the adhesive properties of the adhesive will be almost unaffected when the adhesive is in contact with the liquid or solvent. This is generally in contrast to the use of adhesives that are substantially soluble or dispersible in liquids or solvents that are in contact with the absorbent structure, which upon contact of the liquids or solvents with the substantially soluble or dispersible adhesives is substantially in the liquid or solvent. This is because it will dissolve or disperse and almost no longer exhibit the required adhesion properties.

In the present invention, the term "substantially insoluble" is defined by known experimental techniques such as intrinsic viscosity measurement or light scattering experiments as described in Principles of Colloid and Surface Chemistry, by Paul Hiermenz, 1977. It means that the dissolved portion of the adhesive can hardly be detected in the liquid or solvent in contact with the adhesive, which is incorporated herein by reference.

As used herein, the term "substantially non-dispersible" means that when contacted with the liquid or solvent, the dispersed portion of the adhesive material will be almost filtered out of the liquid or solvent using conventional filter paper within a size distribution range of about 1 μm to about 100 μm. It means you can't.

Thus, solubility studies can theoretically be used to identify oil resistant adhesive polymers. In general, if the adhesive (or its components) is soluble or can be swollen by mineral oils or other oil-based solvents found in skin care products, the oil typically plasticizes and weakens the adhesive and has a poor bond state. And make the adhesive almost useless. However, it has been found that oil-based solubility studies are difficult to carry out and the effects of time and temperature on oil solubility cannot be frequently measured. This solubility measurement only seems to confirm which adhesive polymer is considered for oil resistance applications.

In contrast, rheological measurements have been found to be even more important in predicting the performance of adhesives that maintain adhesive properties when contaminated with oil-based solvents. Rheological measurements are known to take into account the effects of time and temperature on adhesion and are known to show the effects of oil solubility. However, in order to form acceptable oil resistant bonds, it is known that the viscosity of the adhesive also needs to be considered. In general, the viscosity of the adhesive should be wet (wet) or otherwise low enough at the application temperature of the adhesive to make intimate contact with the surface of the film substrate or to mechanically wrap the porous nonwoven substrate. Once the adhesive is in intimate contact with the substrate, the interfacial adhesion will typically increase the adhesive bond. The flow characteristics after being encapsulated with an oil-based solvent should be sufficient to withstand the breakdown of adhesion when the strain of normal use, such as walking, crawling or other movement of the wearer or user is applied. It has been found in the present invention that the required flow and viscosity properties of the adhesive must all be met in order for the adhesive to achieve the required oil resistant adhesive properties.

The required flow properties of the adhesive material of the present invention include those exhibiting effective elastic modulus and elastic modulus values in oil. The elastic modulus value G 'of the adhesive material indicates that the phase's response to strain at shear strain of the sinusoid divided by the strain. That is, this is a measure of the energy stored and recovered per cycle when different systems are compared at the same strain magnitude. It is required that the adhesive material does not exhibit an elastic modulus value that is too low to lack sufficient adhesive strength to withstand layer separation.

Thus, the adhesive of the present invention, when measured according to the method described in the test method section of the present invention, is advantageously about 4 x 10 ⁵ dyne / over a frequency range of about 0.1 to about 100 rad / sec at 40 ° C. cm ² or more, preferably about 6 × 10 ⁵ dyne / cm ² or more, more preferably about 8 × 10 ⁵ dyne / cm ² or more, and exhibit an elastic modulus value of about 8 × 10 ⁷ dyne / cm ² or less .

The elastic modulus value in the oil of the adhesive material means the modulus of elasticity, which represents the ratio of stress to strain when the adhesive material in contact with the oil-based solvent prior to the measurement deforms under dynamic loading. It is required that the adhesive material exhibit no elastic modulus in the oil so low that it does not have sufficient adhesion strength to withstand layer separation.

Thus, the adhesive of the present invention, when measured according to the method described in the test method section of the present invention, is advantageously about 4 x 10 ⁵ dyne / over a frequency range of about 0.1 to about 100 rad / sec at 40 ° C. elastic modulus value in oil of at least cm ² , preferably at least about 6 × 10 ⁵ dyne / cm ² , more suitably at least about 8 × 10 ⁵ dyne / cm ² , and at most about 8 × 10 ⁷ dyne / cm ² Indicates.

Preferably, the adhesive of the invention advantageously exhibits an elastic modulus value in oil that is at least about 50%, suitably at least about 75%, more suitably at least about 90% of the elastic modulus value of the adhesive.

The required processing properties of the adhesive material of the present invention include those exhibiting effective viscosity values. The viscosity value of the adhesive material means the apparent viscosity of the adhesive material. In general, it is required that the adhesive material of the present invention exhibit effective viscosity values at temperatures of about 121 ° C. (250 ° F.) and about 135 ° C. (275 ° F.). The temperature of about 135 ° C. (275 ° F.) is a typical minimum temperature used to apply an adhesive to a nonwoven substrate to make an elastic composite or disposable absorbent article. Temperatures below about 135 [deg.] C. (275 [deg.] F.) are generally not practical for use because the adhesives are generally too viscous to properly apply to nonwoven substrates to create effective adhesive bonds. Temperatures above about 191 ° C. (375 ° F.) are generally not practical for use because substrates such as polypropylene nonwovens to which the adhesive is applied are damaged by too high a temperature.

Thus, the adhesive material may be too strong to cause poor bonds at temperatures of about 135 ° C. (275 ° F.), whereby the adhesive does not effectively penetrate the porous substrate or effectively wet the substrate or otherwise make intimate contact with the substrate. It is required not to exhibit high viscosity values. As such, the adhesives of the present invention are advantageously at most about 40,000 cps, suitably at most about 35,000 cps at a temperature of about 135 ° C. (275 ° F.), as measured according to the methods described in the Test Methods section of the present invention. More suitably a viscosity value of about 30,000 cps or less.

In addition, the adhesive material is required not to exhibit a viscosity value that is too low after the application of the adhesive to the substrate at a temperature of about < RTI ID = 0.0 > 121 C < / RTI > It can move to a different position or otherwise flow. Thus, the adhesive of the present invention is advantageously at least about 60,000 cps, suitably at least about 65,000 cps, more preferably at a temperature of about < RTI ID = 0.0 > 121 C < / RTI > Suitably a viscosity value of at least about 70,000 cps and up to about 1,000,000 cps.

Adhesives useful in the present invention may be of any known type, such as thermoplastic hot melt adhesives, reactive adhesives, and the like. Examples of thermoplastic hot melt adhesives are adhesive materials including polybutylene polymers, hydrocarbon tackifying resins and waxes, available under the name "Findley H9220" from Ato Findley, Inc. Descriptions of hot melt adhesive compositions can be found, for example, in the "CRC Elastomer Technology Handbook", edited by Nicholas P. Cheremisinoff (CRC Press, 1993), Chapter 24, which is incorporated herein by reference. .

Examples of reactive adhesives are two-part polyurethanes, wet cure polyurethanes and epoxies. Chemical reactions of such reactive adhesives are known to those skilled in the art and can be found, for example, in "Contemporary Polymer Chemistry", Harry Alcock and Frederick Lampe, Prentice Hall, 1990, which are incorporated herein by reference. do.

More uniform dispersion of the adhesive will typically reduce the amount of adhesive required to achieve effective and efficient adhesion of the parts in the composite or disposable absorbent article as compared to when the adhesive is not uniformly dispersed. In addition, the upper and lower limits of the amount of adhesive used in the composite or disposable absorbent article may be influenced by the properties of the materials that make up the composite or disposable absorbent article. Generally speaking, people like to use as little adhesive as possible.

In one aspect, the present invention relates to an elastic composite, such as a containment (accommodating) flap, for example for use in disposable absorbent articles. This elastic composite has an inner edge adapted to couple to a disposable absorbent article and a distal edge opposite the inner edge. The elastic composite typically includes a first substrate layer of nonwoven material, a second substrate layer of typically nonwoven material, and an elastic material typically positioned between the first substrate layer and the second substrate layer adjacent to the distal edge of the elastic composite. Member. In certain embodiments of this aspect of the invention, the elastic member is adhesively bonded to the first substrate layer. In a second embodiment of this aspect of the invention, the pattern of intermittent adhesive couples the first layer and the second layer to each other and the elastic member intermittently to the first layer and the second layer. In a third embodiment of this aspect of the invention, the first layer and the second layer are made from one complete piece of material folded. An intermittent pattern of adhesive bonds the first layer and the second layer to each other and the elastic member intermittently to the first layer and the second layer. Such elastic members are described, for example, in pending US patent application Ser. No. 08 / 213,338, filed March 14, 1994, by David P. Kielpikowski.

In another aspect, the present invention relates to a method of making an elastic composite, such as a containment flap, for use in disposable absorbent articles. The method includes providing a substrate of a first layer, such as a nonwoven material, and conveying in a first direction. The two elastic members carried in the first direction are attached to the first layer in a laterally spaced relationship. The second layer of substrate material carried in the first direction is adhesively bonded to the first layer to form a composite having first and second longitudinal side edges. The second layer of substrate material is adhesively bonded to the first layer of substrate material such that the elastic member is positioned between the first layer and the second layer and the first pattern of adhesive bond is positioned between the elastic members. The composite material has slits formed in the first direction between the elastic members to form two slit composite materials. The slit composite is then cut in a second direction perpendicular to the first direction to form a containment flap.

In another aspect, the present invention relates to a method of making an elastic composite, such as a containment flap, for use in disposable absorbent articles. The method includes providing a single complete piece of substrate, such as a nonwoven material, and folding the substrate piece to provide a first layer and a second layer of the substrate; Positioning an elastic member between the first layer and the second layer of the substrate; And intermittently applying the adhesive of the present invention to bond the elastic member to the first layer and the second layer.

Specific examples of materials suitable for use as the first and second layers of the substrate material include nonwoven materials such as spunbond or meltblown thermoplastic polymers such as polyolefins; Adhesive carding webs; Film materials such as polyolefins, ethylene vinyl acetate, ethyl methacrylate and polyester films; Foam materials such as polyolefin foams; Textile materials such as polypropylene, polyethylene or polyester fabrics; And composites and laminates of the nonwovens, films, foams, and fabrics described above. In certain embodiments, the first and second layers of heat-melt material are made of a nonwoven material such as spunbond or meltblown polyethylene or polypropylene material. In another particular embodiment of the invention, the first and second substrate materials are not integrally formed. In other words, the first and second layers of substrate material mean separate elements that are not joined by any method other than heat, adhesive, or similar attachment technique. In particular, the first and second layers are not made from the integral piece of material through the folding process. In another particular embodiment of the invention, the first and second substrate layers are integrally formed. That is, the first and second layers are made from a single complete (integral) piece of material through the folding process.

The elastic member may be stretched to at least about 50%, or at least about 250%, or at least about 350%, and within at least about 75%, more specifically within at least about 50% of the stretched length (initial length + stretch). It is made of any elastomeric material that can be recovered to its length. The elastic member may be in the form of a ribbon, individual strands or other shapes. In one embodiment, the elastic member is in the form of individual elastic yarns of elastomeric material. The elastic composite material of the present invention may be composed of one elastic member or two or more elastic members. In one particular embodiment, the resilient member is manufactured by E.I. It consists of 470 decitex Lycra® yarns commercially available from DuPont de Nemours and Co. In contrast, elastic members are manufactured by J.P.S. Elastomerics Corp.] and thermoplastic elastomers or natural or synthetic rubbers commercially available. In addition, the elastic member may be composed of a heat-active elastic material such as Pebax (registered trademark) commercially available from Atochem, Inc., which is combined with a containment flap and then activated by heat treatment. .

In another aspect, the invention relates to a disposable absorbent article having a front portion, a rear portion, and a crotch portion connecting the front portion and the rear portion. The crotch has an opposite longitudinal side portion. Disposable absorbent articles include a liquid permeable surface sheet, a back sheet attached to the surface sheet, and an absorbent structure positioned between the surface sheet and the back sheet. The pair of elastic composite containment flaps extend longitudinally from the front portion of the disposable absorbent article to the rear portion thereof. The containment flap has an inner edge and a distal edge opposite it. The inner edge is joined to the backsheet at the crotch, front and back. The containment flap is an elastic member positioned between the first layer of heat-melt material, the second layer of heat-melt material, and the first and second layers of heat-melt material adjacent the distal edge. Is done.

One skilled in the art will know which materials are suitable for use as the surface sheet and back sheet. Examples of materials suitable for use as surface sheets are liquid permeable materials such as spunbond polypropylene or polyethylene having a basis weight of about 15 to about 25 g / m ² . Examples of materials suitable for use as backsheets are vapor permeable materials such as microporous polyolefin films as well as liquid impermeable materials such as polyolefin films.

In general, suitable absorbent structures will consist of the hydrogel-forming polymeric material dispersed in the fibrous matrix, such as for example, the fibrous matrix pressing or capturing the hydrogel-forming polymeric material.

By "hydrogel-forming polymeric material" is meant herein a superabsorbent material, often referred to as superabsorbent material. Such superabsorbent materials may comprise synthetic urine in which superabsorbent materials are used, 0.9 wt% saline solution, or a body fluid such as menstrual fluid, urine or blood, at least about 10 times, suitably about 20 times or more, about Amounts up to 100 can generally be absorbed. Examples of typical conditions are atmospheric conditions such as temperatures of about 0 ° C. to about 100 ° C., and suitably about 23 ° C. and relative humidity of about 30 to about 60%. Upon absorption of the liquid, the superabsorbent material typically swells and forms a hydrogel.

Superabsorbent materials may be made of organic polymer materials that form hydrogels, which may include natural materials such as agar, pectin and guar gum, as well as synthetic polymer materials that form hydrogels. Examples of synthetic hydrogel forming polymer materials include carboxymethyl cellulose, alkali metal salts of polyacrylic acid, polyacrylamide, polyvinyl alcohol, ethylene maleic anhydride copolymers, polyvinylether, hydroxypropyl cellulose, polyvinyl morpholinone , Polymers and copolymers of vinyl sulfonic acid, polyacrylates, polyacrylamides, and polyvinyl pyridine. Other suitable hydrogel-forming polymer materials include hydrolyzed acrylonitrile graft starch, acrylic acid graft starch, isobutylene maleic anhydride copolymer and mixtures thereof. The hydrogel-forming polymeric material is preferably lightly crosslinked to render the material almost water insoluble and water swellable. The crosslinking may be for example by light irradiation or may be a covalent, ionic, van der Waals or hydrogen bond. Suitable hydrogel-forming polymer materials are typically available from various commercial suppliers, such as The Dow Chemical Company, Hoechst Celanese, Allied Colloid Limited, or Stockhausen, Inc.

Suitably, the hydrogel-forming polymer material is in the range of about 50 μm to about 1000 μm, more suitably about 100 μm in the unswelled state as measured by sieve analysis according to ASTM test method D-1921. In the form of particles having a largest cross-sectional diameter in the range of from about 800 μm. It is understood that the particles of the hydrogel-forming polymeric material that fall within the range of sizes described above may include aggregated particles consisting of solid particles, porous particles, or a plurality of smaller particles aggregated into particles within the range of sizes described above. Should be.

The hydrogel-forming polymeric material is present in the absorbent structure of the present invention in an amount sufficient to make an absorbent structure capable of absorbing the required amount of liquid under the required conditions. The hydrogel-forming polymer material is advantageously about 5 to 95 weight percent, suitably about 15 to about 85 weight percent, more suitably about 20, based on the total weight of the hydrogel-forming polymer material in the absorbent structure. Present in the absorbent structure of the present invention in an amount from about 80% by weight.

As used herein, the term “fiber” or “fibrous” means a particulate material having a ratio of length to diameter of greater than about 10. Conversely, "non-fibrous" or "non-fibrous" material means a particle material having a ratio of length to diameter of about 10 or less.

The fibrous matrix may be produced by air-laden fibers via a spunbond or meltblown process, a carding process, a wet process, or basically any other means known to those skilled in the fibrous matrix manufacturing art.

Methods of incorporating the hydrogel-forming polymeric material of the present invention into a fibrous matrix are known to those skilled in the art. Suitable methods include forming the matrix by air-laminating the fibers of the fibrous matrix and the hydrogel-forming polymeric material simultaneously or by wet-laminating the fibers and the hydrogel-forming polymeric material of the fibrous matrix simultaneously. There is a method of incorporating a hydrogel-forming polymeric material into the matrix. Alternatively, it is also possible to apply the hydrogel-forming polymeric material to the fibrous matrix after formation of the fibrous matrix. Another method is to sandwich a hydrogel-forming polymeric material between two sheet materials, at least one of which is fibrous and liquid permeable. In general, the hydrogel-forming polymer material may be located uniformly between the two sheet materials or in the form of separate pockets formed in the two sheets. The hydrogel-forming polymeric material may generally be distributed in several separate layers in a uniform manner or may be present in the fibrous layer as one layer or may be otherwise unevenly distributed.

The fibrous matrix may be in the form of an integrally formed single layer of a composite of multiple layers. If the fibrous matrix comprises a plurality of layers, the layers are preferably in liquid communication with each other so that the liquid present in one fibrous layer can be flowed or transported to another fibrous layer. For example, the fibrous layer may be separated by cellulose tissue wrap sheets known to those skilled in the art.

When the fibrous matrix comprises one layer formed integrally, the concentration of the hydrogel-forming polymeric material may increase gradually, steplessly or stepwise along the thickness of the fibrous matrix. Similarly, the density can decrease either steplessly or stepwise through its thickness. In general, the absorbent structure of the present invention may be of any size or dimension so long as it exhibits the desired absorbent properties.

In addition, the absorbent structures of the present invention can be used or combined with other absorbent structures, and the absorbent structures of the present invention can be used as separate layers or as individual regions or regions within larger composite absorbent structures. The absorbent structures of the present invention can be combined with other absorbent structures by methods well known to those skilled in the art, such as by using adhesives or stacking other structures together and holding the composite structures together, such as by tissue.

The absorbent structure according to the invention is adapted to absorb many liquids such as water, saline, synthetic urine, and body fluids such as urine, menstrual fluid, blood, and the like, and disposable absorbent articles such as diapers, adult incontinence products, bed pads, etc. ; Physiological products such as sanitary naphkines and tampons; It is adapted for use in wipers, bibs, wound bandages and other absorbent articles such as surgical capes or drapes.

Disposable absorbent articles according to all aspects of the present invention are generally subjected to multiple contaminations of body fluids during use. Thus, the disposable absorbent article may preferably absorb several packs of body fluid in an amount such that the absorbent article and its structure will be exposed during use. In general, these contaminations are separated from each other in time.

<Test method>

<Elastic modulus>

The elastic modulus value of the adhesive material sample is measured for bulk adhesive samples that are not suspended on any substrate. Samples of a round adhesive material having a thickness of about 2 to about 3 mm and a diameter of about 25 mm are prepared. This adhesive material sample was manufactured by Rheometrics, Inc. 1 is placed on the bottom of two plates of 25 mm diameter of parallel plate fixture on a mechanically driven vibration system of the device Rheometrics RDS IIE Dynamic Spectrometer available from Possumtown Road, 08854, New Jersey. The top plate is lowered onto the adhesive material sample until the system's conventional force meter notices a slight deformation. If necessary, the adhesive sample can be heated above the melting point to provide sufficient adhesion to adhere to the plate. The adhesive material sample is then equilibrated in a heated pressurized air test chamber at about 40 ° C., which temperature is chosen to best reflect the wearer body temperature of the disposable absorbent article. A small computer is then used to control the application of 1% peak to peak shear strain to the adhesive material sample, and the application frequency is adjusted in fractions of rad / sec. The elastic modulus value of the adhesive material sample can be calculated from the geometric elements, the peak-to-peak magnitude of the torque signal, and the phase delay of the torque output wave. Typically, computers using software from Rheometrics, Inc. are used to control the operation of mechanically driven vibration systems and to calculate elastic modulus values and other rheological parameters of the adhesive material sample. This elastic modulus value can be expressed as a frequency sweep of about 0.1 rad / sec to about 100 rad / sec. The frequency range of about 0.1 rad / sec to about 100 rad / sec is the dynamic limit of the mechanically driven vibration system of the device [Rheometrics RDS IIE Dynamic Spectrometer] used in the present invention, but this frequency range also means that the disposable absorbent article may be worn in diapers. Corresponds to the frequency (or time magnitude) typically encountered during use, such as during infant walking.

Except as otherwise described herein, elastic modulus values and other rheological properties are measured as described in the standard test method ASTM D4440-93 ["Standard Practice for Rheological Measurement of Polymer Melts Using Dynamic Mechanical Procedures"]. The entirety of which is incorporated herein by reference. Further explanations of polymer rheology and measurements can be found in "Viscosity Properties of Polymer", John D. Ferry, John Wiley and Sons, 3rd edition, pages 41-43, 1980. It is adopted as a reference of the present invention.

<Elastic modulus in oil>

Several circular adhesive material samples were prepared, each having a thickness of about 1 mm and a diameter of about 25 mm. This adhesive material sample was immersed in an infant oil composition comprising mineral oil, fragrance and tocopheryl acetate, available from the company Johnson & Johnson Consumer Products, Inc., Skillman, New jersey for about 4 hours. Let it be. A thickness of about 1 mm is used to better penetrate the infant oil through the entire thickness of the adhesive material sample. The adhesive material sample is then removed from the infant oil and the stain is dried with paper towels. Next, about three of the 1 mm thick adhesive material samples are stacked together to obtain a single adhesive material sample having a thickness of about 2 to 3 mm. Then, a single adhesive material sample consisting of a stack of 1 mm thick adhesive material samples is placed on the bottom of two 25 mm diameter plates of the parallel plate fixture on the mechanically driven vibration system of the device [Rheometrics RDS IIE Dynamic Spectrometer] and elastic modulus The elastic modulus value in the oil of the adhesive material sample is basically determined using the same test method as the sample used to determine the value.

<Viscosity>

The viscosity value of the adhesive material sample is measured for the bulk adhesive sample. A device available from the company Brookfield Engineering laboratories, Inc., Stoughton, Massachusetts [Brookfield Model DVIII RV series thermocel system viscometer] is used. About 10.5 grams of adhesive material sample is placed in a heated thermocell and allowed to heat for about 15-20 minutes at an initial temperature of about 204 ° C. (about 400 ° F.). Lower the stainless steel spindle (model number SC27) into the heated thermocell and attach it to the viscometer. This spindle speed is adjusted so that the indicated% torque value is from about 20 to about 80% of the total size. Viscosity recording is made approximately every 5 minutes until the recording is stabilized (+/- 0.5% torque value) for about 10 minutes. This stabilized record is recorded as the viscosity value at that temperature. The temperature fix point is then reduced to about 14 ° C. (about 25 ° F.) and the process repeated.

Except as otherwise stated herein, viscosity values are measured as described in the Standard Test Method for Apparent Viscosity of Hot Melt Adhesives and Coating Materials. Is incorporated by reference of the present invention.

<Example>

Sample 1 is a styrene-isoprene-styrene rubber block copolymer, hydrocarbon tackifier resin and mineral oil, available under the name "Findley H2525A" from the company Ato Findley, Inc., 11320 Watertown Plank Road, Wauwatosa, Wisconsin, 53226. Adhesive material comprising a.

Sample 2 is an adhesive material comprising a polyester polymer, a polar tackifying resin and a polyester plasticizer, available from the company Ato Findley, Inc. under the name "Findley H9202".

Sample 3 is an adhesive material comprising a polyamide polymer, a rosin ester tackifying resin and a polar plasticizer, available from the company Ato Findley, Inc. under the name “Findley 1142-144A”.

Sample 4 is an adhesive material comprising a polybutylene polymer, a hydrocarbon tackifying resin, a wax and a nucleating agent, available from the company Ato Findley, Inc. under the name “Findley H9220”.

Sample 5 is an adhesive material comprising styrene-butadiene-styrene rubber block copolymers, hydrocarbon tackifying resins and mineral oils, available from the company Ato Findley, Inc. under the name “Findley H4013”.

Sample 6 is an adhesive material comprising styrene-isoprene-styrene rubber block copolymers, hydrocarbon tackifying resins and mineral oils, available from the company Ato Findley, Inc. under the name "Findley H2096".

Sample 7 is an adhesive material comprising a polybutylene polymer, a hydrocarbon tackifying resin and a wax, available from the company Ato Findley, Inc. under the name “Findley H9214”.

The elastic modulus in the elastic modulus and oil for the samples was measured according to the test method described in the present invention. The result of the measurement is shown in Table 1.

Viscosity values were also measured for the samples according to the test methods described herein. The measurement results are shown in Table 2.

Elastic modulus and elastic modulus in oil at 40 ° C (dyne / cm ² ) Adhesive sample 0.1 rad / sec 1 rad / sec 10 rad / sec 100 rad / sec ^* Sample 1 4.05 × 10 ⁵ 4.75 × 10 ⁵ 6.52 × 10 ⁵ 1.35 × 10 ^{6 *} Sample 1 with oil 2.41 × 10 ⁵ 2.75 × 10 ⁵ 3.41 × 10 ⁵ 5.40 × 10 ^{5 *} Sample 2 2.44 × 10 ⁷ 2.49 × 10 ⁷ 2.55 × 10 ⁷ 2.62 × 10 ^{7 *} Sample 2 with oil 1.75 × 10 ⁷ 1.79 × 10 ⁷ 1.95 × 10 ⁷ 2.05 × 10 ^{7 *} Sample 3 2.20 × 10 ⁷ 2.22 × 10 ⁷ 2.23 × 10 ⁷ 2.25 × 10 ^{7 *} Sample 3 with oil 2.32 × 10 ⁷ 2.36 × 10 ⁷ 2.37 × 10 ⁷ 2.39 × 10 ⁷ Sample 4 1.71 × 10 ⁷ 1.81 × 10 ⁷ 1.92 × 10 ⁷ 2.04 × 10 ⁷ Sample with oils 4 1.09 × 10 ⁷ 1.03 × 10 ⁷ 1.19 × 10 ⁷ 1.36 × 10 ^{7 *} Sample 5 1.43 × 10 ⁵ 2.26 × 10 ⁵ 3.62 × 10 ⁵ 5.88 × 10 ^{5 *} Sample 6 2.75 × 10 ⁵ 3.72 × 10 ⁵ 5.86 × 10 ⁵ 1.17 × 10 ^{6 *} Sample 7 1.20 × 10 ⁷ 1.43 × 10 ⁷ 1.66 × 10 ⁷ 1.89 × 10 ⁷ * Not a sample of the present invention

Viscosity value (cp) Adhesive sample 204 ° C (400 ° F) 191 ° C (375 ° F) 177 ° C (350 ° F) 163 ° C (325 ° F) 149 ° C (300 ° F) 135 ° C (275 ° F) 121 ° C (250 ° F) ^* Sample 1 2,190 2,780 4,200 6,600 11,900 24,400 63,000 ^* Sample 2 10,400 13,200 18,600 27,500 43,700 77,000 140,000 ^* Sample 3 3,000 4,285 6,985 12,150 22,925 47,800 > 150,000 Sample 4 3,300 4,300 6,050 8,830 13,700 23,400 > 150,000 ^* Sample 7 4,300 5,480 7,450 10,500 17,000 28,000 46,000 * Not a sample of the present invention

Several adhesive materials were used to produce composites consisting of elastic yarns and nonwoven substrates. The composite is manufactured using an EI Du Pont de Nemours Company using a 0.5 mm nozzle at an adhesive temperature of about 150 ° C. to about 185 ° C. (about 300 ° F. to about 365 ° F.) and an air temperature of about 200 ° C. (about 400 ° F.). Spirally spraying about 15.5 grams of adhesive sample per m ² of substrate onto a polypropylene nonwoven substrate having about 2% polyurethane stretch, available as the name "LYCRA XA" polyurethane yarn, Prepared by conveying at a web speed of about 50 m / min with an opening time of about 0.25 seconds. After application of the adhesive, a second polypropylene nonwoven substrate layer is laminated on the first polypropylene nonwoven substrate layer, and the polyurethane seal is sandwiched between the two substrates.

An oil-contaminated composite is about 0.2 ml of the infant oil composition comprising mineral oil, fragrance and tocopheryl acetate, available from the company Johnson & Johnson Consumer Products, Inc., Skillman, New Jersey. Directly applied to the adhesive region of the width, the oil-contaminated composite is prepared by equilibrating for about 2 minutes at room temperature (about 23 ℃).

Peel strength of the composite and the oil contaminated composite was measured using a T-peel test based on ASTM Test Method D11875-61T, which is incorporated herein by reference in its entirety. The test apparatus used was a Sintech Model 1 tensile tester available from MTS Corp., Minneapolis, Minnesota. A composite sample 1 inch wide (in the stretched state) is placed in the test fixture of the tensile tester and pulled at a rate of about 100 mm / min. The maximum size load was about 4540 grams. The results of this measurement are shown in Table 3. Peel strength of each composite is expressed as peak load in grams. The energy is calculated as the area under the curve. The loss rate is calculated by dividing the oil contaminated value by the uncontaminated value.

Adhesive sample Peak load in grams Peak load loss (%) Energy (Kg-mm) Energy loss (%) ^* Sample 1 693 - 12.3 - ^* Sample 1 with oil 196 72 3.4 72 ^* Sample 2 110 - 0.9 - ^* Sample 2 with oil 22 80 0.1 89 ^* Sample 3 181 - 1.8 - ^* Sample 3 with oil 63 65 0.5 72 Sample 4 767 - 11.2 - Sample with oils 4 491 36 5.9 47 * Not a sample of the present invention

It is clear from the data that Sample 4 has better peel strength after oil contamination than other samples. A minimum peak peel strength level of about 300 grams is generally preferred because it is the force typically required to break a typical polypropylene nonwoven substrate. Below this minimum peak peel strength level, there is a possibility that the adhesive bond will fail, and exposure of the elastic yarn or other product components may occur.

While the invention has been described in detail with reference to specific embodiments thereof, those skilled in the art will readily recognize variations, modifications, and equivalents of the above embodiments when understanding the invention described above. Accordingly, the scope of the invention should be construed as the scope of the appended claims and any equivalents thereof.

Claims (18)

a) an elastic modulus value of at least about 4 × 10 ⁵ dyne / cm ² at a frequency range of about 0.1 to about 100 rad / sec at 40 ° C .; b) an elastic modulus value in oil of at least about 4 × 10 ⁵ dyne / cm ² over a frequency range of about 0.1 to about 100 rad / sec at 40 ° C .; c) a viscosity value of about 40,000 cp or less at a temperature of about 135 ° C. (275 ° F.); And d) the first substrate is attached to the second substrate by an adhesive exhibiting a viscosity value of at least about 60,000 cp at a temperature of about 121 ° C. (250 ° F.), with an elastic member positioned between the first substrate and the second substrate. Elastic composite. The elastic composite of claim 1, wherein the adhesive exhibits an elastic modulus value of at least about 6 × 10 ⁵ dyne / cm ² at a frequency ranging from about 0.1 to about 100 rad / sec at 40 ° C. ³ . The elastic composite of claim 1, wherein the adhesive exhibits an elastic modulus value in oil of at least about 6 × 10 ⁵ dyne / cm ² at a frequency ranging from about 0.1 to about 100 rad / sec at 40 ° C. ³ . The elastic composite of claim 1, wherein the adhesive exhibits a viscosity value of about 35,000 cp or less at a temperature of about 135 ° C. (275 ° F.). The elastic composite of claim 1, wherein the adhesive exhibits a viscosity value of at least about 65,000 cp at a temperature of about 121 ° C. (250 ° F.). The method of claim 1, wherein the adhesive has an elastic modulus value of at least about 6 × 10 ⁵ dyne / cm ² at a frequency ranging from about 0.1 to about 100 rad / sec at 40 ° C., from about 0.1 to about 100 rad / sec at 40 ° C. Elastic modulus in an oil of at least about 6 × 10 ⁵ dyne / cm ² over a frequency range of, a viscosity value of about 35,000 cp or less at a temperature of about 135 ° C. (275 ° F.), and a temperature of about 121 ° C. (250 ° F.) Elastic composite exhibiting a viscosity value of at least about 65,000 cp. The method of claim 1, wherein the adhesive has an elastic modulus value of at least about 8 × 10 ⁵ dyne / cm ² at a frequency ranging from about 0.1 to about 100 rad / sec at 40 ° C., from about 0.1 to about 100 rad / sec at 40 ° C. Elastic modulus in an oil of at least about 8 × 10 ⁵ dyne / cm ² over a frequency range of, a viscosity value of less than or equal to about 30,000 cp at a temperature of about 135 ° C. (275 ° F.), and a temperature of about 121 ° C. (250 ° F.) Elastic composite exhibiting a viscosity value of at least about 70,000 cp. The elastic composite of claim 1, wherein the adhesive comprises a polybutylene polymer. The elastic composite of claim 8, wherein the adhesive further comprises a tackifying resin, a wax, and a nucleating agent. The method of claim 1, wherein the first substrate is selected from the group consisting of a nonwoven material, an adhesive carding web, a film material, a foam material and a fabric material, and the second substrate is a nonwoven material, an adhesive carding web, a film material, and a foam material. And an elastic composite material selected from the group consisting of fabric materials. The elastic composite of claim 1, wherein the first substrate is a nonwoven material and the second substrate is a nonwoven material. The elastic composite of claim 1, wherein the first substrate is a nonwoven material made of polyolefin, and the second substrate is a nonwoven material made of polyolefin. The elastic composite of claim 1, wherein the elastic member is capable of stretching at least about 50% of its initial length. Providing a first substrate and positioning an elastic member on the first substrate, and then bonding the second substrate to the first substrate by an adhesive, wherein the elastic member comprises the first substrate and the second substrate. Between the adhesive, a) an elastic modulus value of at least about 4 × 10 ⁵ dyne / cm ² at a frequency range of about 0.1 to about 100 rad / sec at 40 ° C .; b) an elastic modulus value in oil of at least about 4 × 10 ⁵ dyne / cm ² over a frequency range of about 0.1 to about 100 rad / sec at 40 ° C .; c) a viscosity value of about 40,000 cp or less at a temperature of about 135 ° C. (275 ° F.); And d) at least about 60,000 cp of viscosity at a temperature of about 121 ° C. (250 ° F.). The method of claim 14, wherein the adhesive has an elastic modulus value of at least about 8 × 10 ⁵ dyne / cm ² at a frequency range of about 0.1 to about 100 rad / sec at 40 ° C., and about 0.1 to about 100 rad / sec at 40 ° C. 16. Elastic modulus in an oil of at least about 8 × 10 ⁵ dyne / cm ² over a frequency range of, a viscosity value of less than or equal to about 30,000 cp at a temperature of about 135 ° C. (275 ° F.), and a temperature of about 121 ° C. (250 ° F.) Elastomeric composite having a viscosity value of at least about 70,000 cp. The method of claim 14, wherein the adhesive comprises a polybutylene polymer. The method of claim 15 wherein the adhesive further comprises a tackifying resin, a wax and a nucleating agent. 15. The method of claim 14 wherein the first substrate is selected from the group consisting of nonwoven materials, adhesive carding webs, film materials, foam materials and fabric materials, and wherein the second substrates are nonwoven materials, adhesive carding webs, film materials, foam materials And a textile material.