Adhesive composition for absorbent articles

Abstract

Described herein is an adhesive composition comprising the copolymer. The adhesive composition has a viscosity of about 2,000 mPa·s to about 11,500 mPa·s at 150°C. The adhesive composition has a storage modulus of about 3 MPa to 9.5 MPa at 37°C. The adhesive composition has a yield stress of about 0.8 MPa to about 1.45 MPa at 37°C.

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE Disclosed herein are adhesive compositions for absorbent and textile articles. [Background technology]

[0002] Adhesive compositions, such as hot melt adhesive compositions, are a type of adhesive that is applied in molten form onto the parts to be adhesively bonded before cooling to harden and solidify. Olefin-based hot melt adhesives require good bonding properties to ensure that the adhesive can be bonded to the substrate, but these bonding properties can make the adhesive difficult to process during manufacturing. During the adhesive production and application process, the equipment used to process the adhesive and form the adhesive-bonded article can be damaged or require constant maintenance due to hardened adhesive residues that accumulate on the equipment parts. These residues can have a destructive effect on rotating parts such as rollers, shafts or rolls, and parts intended to form the hot melt adhesive, such as extrusion dies, pressure rollers, or lamination tools.

[0003] A typical hot melt adhesive is made by combining polymer and additive components into a substantially homogeneous thermoplastic blend. Typical additives can include, for example, tackifiers, plasticizers, and / or waxes. While such formulations generally work, they can be expensive and their performance characteristics can be improved. For example, tackifiers, which can comprise up to 65% of the adhesive composition, can be expensive and difficult to source. Summary of the Invention [Problem to be solved by the invention]

[0004] Thus, there is a continuing need for improved adhesive compositions that offer better performance, improved processability, and lower cost. [Means for solving the problem]

[0005] 1. An adhesive composition comprising a copolymer, the adhesive composition having a viscosity of about 2,000 mPa·s to about 11,500 mPa·s at 150°C when measured by a Viscosity Test Method, and a storage modulus of about 3 MPa to 9.5 MPa at 37°C when measured by an Oscillatory Rheometry Test Method; Described herein are adhesive compositions that have a yield stress at 37° C. of from about 0.8 MPa to about 1.45 MPa as measured by the Elongation Test Method.

[0006] Also described herein is an adhesive composition comprising a copolymer, the copolymer comprising propene monomer units and 1-butene monomer units, the copolymer having a viscosity of about 2,000 cP to about 11,500 cP at 150° C., as measured by the Viscosity Test Method, and a storage modulus of about 3 MPa to 9.5 MPa at 37° C., as measured by the Oscillation Rheometry Test Method.

[0007] Also provided is an adhesive composition comprising a copolymer, the adhesive composition not comprising a tackifier, the copolymer comprising a propene monomer unit and a 1-butene monomer unit, the copolymer having a viscosity of about 2,000 cP to about 11,500 cP at 150°C when measured by the Viscosity Test Method, an average melting enthalpy of less than 17 J / g when measured by the Melting Enthalpy Test Method, a storage modulus of about 3 MPa to 9.5 MPa at 37°C when measured by the Oscillation Rheometry Test Method, a yield stress of about 0.8 MPa to about 1.45 MPa at 37°C when measured by the Elongation Test Method, a yield tensile strength of about 0.5 MPa to about 1.5 MPa when measured by the Yield Tensile Strength Test Method, and a viscosity of about 2 MJ / m at 37°C when measured by the Elongation Test Method. 3 ~about 8MJ / m 3 Also described herein is an adhesive composition having a toughness of DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The following definitions may be useful in understanding this disclosure.

[0009] "Amorphous," as used herein, refers to the substantial absence of crystallinity, (eg) less than 5% and less than 1%.

[0010] "Copolymer," as used herein, refers to a polymer formed by the polymerization of at least two different monomers. The term "copolymer" can include terpolymers, which contain three different monomers.

[0011] "Free," "absent," and the like, as these terms are used herein, mean that the adhesive composition does not have more than trace amounts of the given material, ingredient, or characteristic following the modifier, that the amount of the material or ingredient does not cause harm or irritation that consumers typically associate with the material or ingredient, or that the material or ingredient has not been intentionally added to the adhesive composition. In some cases, "free" and "absent" can mean that there is no measurable amount of the material or ingredient. For example, some forms of the adhesive composition may not contain a measurable amount of tackifier.

[0012] "Heterophasic" polymers, as used herein, refer to polymers that have amorphous characteristics and at least some substantial crystalline content (at least 10% by weight crystalline content) that can provide cohesive strength to the cooled adhesive mass. The crystalline portions can be in the form of stereoregular blocks or sequences.

[0013] "Nonwoven" herein refers to a fibrous structure that is not woven or knitted and is made from the assembly of continuous fibers, coextruded fibers, non-continuous fibers, and combinations thereof, by a process such as spunbonding, carding, meltblowing, airlaying, wet lamination, coforming, or other such processes known in the art for such purpose.

[0014] "Substrate" as used herein refers to a material that is primarily two-dimensional (e.g., in the XY plane) and has a relatively small thickness (Z direction) compared to the length (X direction) and width (Y direction) of the substrate (e.g., 1 / 10 or less). Non-limiting examples of substrates include webs, layers or layers or films and foils, such as fibrous materials, nonwovens, polymeric films or metal foils. These materials may be used alone or may include two or more layers bonded together. Thus, a web is a substrate.

[0015] As used herein, percentages are given as the weight of the component relative to the total weight of the material, unless otherwise stated.

[0016] Values ​​disclosed herein as range endpoints should not be understood as being strictly limited to the exact numerical values ​​recited. Rather, unless otherwise indicated, each numerical range is intended to mean both the recited values ​​and any integers within that range. For example, a range disclosed as "1 to 10" is intended to mean "1, 2, 3, 4, 5, 6, 7, 8, 9, 10."

[0017] As used herein, the articles "a" and "an," e.g., "an anionic emulsifier" or "a fiber," as used herein, are understood to mean one or more of the claimed or described material.

[0018] Adhesive Composition Described herein are adhesive compositions comprising at least 50%, alternatively at least 65%, alternatively at least 80%, alternatively at least 85%, alternatively at least 90%, alternatively at least 95%, alternatively at least 98%, alternatively at least 99% by weight of a copolymer. The copolymer may be an amorphous copolymer having a crystalline content of less than 10% by weight, alternatively less than 5% by weight.

[0019] Alternatively, adhesive compositions described herein include from about 70% to about 90% by weight of one or more copolymers, alternatively from about 75% to about 85% by weight, alternatively from about 50% to about 80% by weight, alternatively from about 55% to about 75% by weight, alternatively from about 60% to about 70% by weight, alternatively from about 30% to about 55% by weight, alternatively from about 35% to about 45% by weight, alternatively from about 40% to about 50% by weight of one or more copolymers.

[0020] The one or more copolymers may include a first copolymer and a second copolymer. The adhesive composition may include about 35% to about 80% by weight, alternatively about 45% to about 70% by weight, alternatively about 40% to about 75% by weight, alternatively about 55% to about 65% by weight, alternatively about 40% to about 55% by weight, alternatively about 50% to about 60% by weight of the first copolymer. The adhesive composition may include about 5% to about 40% by weight, alternatively about 10% to about 35% by weight, alternatively about 15% to about 30% by weight, alternatively about 20% to about 25% by weight, alternatively about 10% to about 45% by weight of the second copolymer.

[0021] The copolymer may contain from about 30% to about 70% by weight, alternatively from about 35% to about 65% by weight, alternatively from about 40% to about 60% by weight, alternatively from about 40% to about 55% by weight, alternatively from about 45% to about 55% by weight, alternatively from about 44% to about 46% by weight, alternatively from about 48% to about 52% by weight of propene monomer units. The percentage of propene monomer units can be determined by any suitable method known to those of skill in the art, such as nuclear magnetic resonance or infrared spectroscopy.

[0022] The copolymer may contain from about 30% to about 70% by weight, alternatively from about 35% to about 65% by weight, alternatively from about 40% to about 60% by weight, alternatively from about 45% to about 60% by weight, alternatively from about 45% to about 55% by weight, alternatively from about 50% to about 60% by weight, alternatively from about 54% to about 56% by weight, alternatively from about 48% to about 52% by weight of 1-butene monomer units. The percentage of 1-butene monomer units can be determined by any suitable method known to one of skill in the art, such as nuclear magnetic resonance or infrared spectroscopy.

[0023] The copolymer may comprise from about 1% to about 40%, alternatively from about 2% to about 30%, alternatively from about 5% to about 20%, alternatively from about 5% to about 15% by weight of one or more comonomer units selected from the group consisting of ethylene, 4-methyl-1-pentene, pentene-1, 2-methylpentene-1, 3-methylbutene-1, heptene-1, dimethylpentene-1, trimethylbutene-1, ethylpentene-1, methylpentene-1, trimethylpentene-1, methylethylpentene-1, diethylbutene-1, propylpentane-1, decene-1, methylnonene-1, nonene-1, trimethylheptene-1, methylethylbutene-1, dodecene-1, and hexadodecene-1, and combinations thereof.

[0024] The copolymers can be prepared by the methods described in U.S. Patent Nos. 5,302,675 and 5,723,546, both of which are expressly incorporated herein by reference. The copolymers can be prepared using a single-site catalyst system, multiple single-site catalyst systems, or a Ziegler Natta catalyst system. The monomers used to prepare the copolymers can be obtained from one or more carbon-based sources, such as biomass from animal and / or vegetable fats. The monomers can also be obtained from renewable feedstocks, such as those provided by Neste's Rotterdam Refinery (Neste, Finland). The adhesive composition containing the copolymer can be prepared by combining the copolymer with at least one optional ingredient (e.g., optical brightener, other copolymers) as needed. The copolymer can be prepared into a final adhesive composition product by heating the primary copolymer to an elevated temperature (e.g., about 135 to about 175° C.) that melts the copolymer. Once melted, one or more optional ingredients (e.g., additives or other polymeric ingredients) may be added to the primary copolymer. A mixer can be used to mix the components together into the final adhesive composition.

[0025] The copolymer may be selected from REXtac® copolymers 2815 and 2830. See, for example, U.S. Patent No. 5,723,546 to Sustic, expressly incorporated by reference, for a description of additional exemplary copolymers.

[0026] The adhesive composition may comprise from about 10% to about 30% by weight, alternatively from about 15% to about 25% by weight, alternatively from about 20% to about 60% by weight, alternatively from about 20% to about 50% by weight, alternatively from about 25% to about 55% by weight, alternatively from about 30% to about 40% by weight, alternatively from about 25% to about 35% by weight of one or more heterophasic copolymers.

[0027] The one or more heterophasic copolymers may include a first heterophasic copolymer and a second heterophasic copolymer. The adhesive composition may include from about 2% to about 18% by weight, alternatively from about 5% to about 15% by weight, alternatively from about 10% to about 25% by weight, alternatively from about 15% to about 20% by weight, alternatively from about 8% to about 12% by weight of the first heterophasic copolymer. The adhesive composition may include from about 2% to about 18% by weight, alternatively from about 5% to about 15% by weight, alternatively from about 10% to about 25% by weight, alternatively from about 15% to about 20% by weight, alternatively from about 8% to about 12% by weight of the second heterophasic copolymer. The first heterophasic copolymer may have a higher or lower enthalpy of melting than the second heterophasic copolymer as measured by the Melting Enthalpy Test Method described herein.

[0028] Heterophasic copolymers may be made using one or more metallocene catalyst blends to obtain the desired heterophasic structure.

[0029] The adhesive composition may include less than 20% by weight, alternatively less than 10% by weight, alternatively less than 5% by weight, alternatively less than 3% by weight, alternatively less than 2% by weight, alternatively less than 1% by weight, alternatively less than 0.5% by weight, alternatively less than 0.1% by weight of a tackifier. Exemplary tackifiers may include aliphatic 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, and hydrogenated rosin esters.

[0030] The adhesive composition may be free of tackifiers. Minimizing or avoiding the use of tackifiers has significant advantages, since it can reduce the cost of the adhesive composition, as well as eliminate additional components and potential problems that may be associated with the supply of the additional components. Furthermore, tackifiers can impart undesirable odors in disposable articles, and can also act as carriers for low molecular weight plasticizers (e.g., process oils used in SBC-based adhesives) that can embrittle polyethylene backsheet materials used in absorbent and textile articles.

[0031] The adhesive composition may be free of polyisobutylene. The adhesive composition may be free of heterophasic copolymers. The adhesive composition may contain less than 10% by weight polyisobutylene, alternatively less than 5% by weight, alternatively less than 3% by weight, alternatively less than 2% by weight, alternatively less than 1% by weight, alternatively less than 0.5% by weight, alternatively less than 0.1% by weight.

[0032] Adhesive composition properties The copolymers, as well as adhesive compositions including the copolymers, may have a viscosity at 150° C. of from about 2,000 mPa·s to about 11,500 mPa·s, alternatively from about 3,000 mPa·s to about 8,500 mPa·s, alternatively from about 4,000 mPa·s to about 6,500 mPa·s, alternatively from about 4,500 mPa·s to about 6,000 mPa·s, alternatively from about 5,000 mPa·s to about 5,500 mPa·s, alternatively less than 7,500 mPa·s, alternatively less than 6,500 mPa·s, when measured by the Viscosity Test Method described herein.

[0033] The copolymers, and adhesive compositions containing the copolymers, can have suitable rheology and thermal stability for use with conventional hot melt adhesive application equipment. Copolymers, and adhesive compositions containing the copolymers, having the desired viscosity at application temperatures can facilitate the flow of the copolymers, and adhesive compositions containing the copolymers, through coating equipment, such as coating dies or spray nozzles.

[0034] A desirable viscosity value can be useful to ensure that the copolymer, and adhesive compositions containing the copolymer, are compatible with adhesive application methods and equipment, for example, a viscosity value that is too high may not be compatible with certain application methods and equipment, such as spray methods and nozzles.

[0035] The copolymers, as well as adhesive compositions including the copolymers, may have an enthalpy of fusion at a cooling rate of 1° C. / min of less than 17 J / g, alternatively less than 16.5 J / g, alternatively less than 16 J / g, alternatively from about 6.5 J / g to 17 J / g, alternatively from about 7 J / g to about 16.5 J / g, alternatively from about 8 J / g to about 16 J / g, alternatively from about 8.7 J / g to about 15.8 J / g, alternatively from about 10 J / g to about 16 J / g, as measured by the Melting Enthalpy Test Method described herein.

[0036] The copolymers and adhesive compositions containing the copolymers may have a yield tensile strength of about 0.5 MPa to about 1.5 MPa, alternatively about 0.7 MPa to about 1.4 MPa, alternatively about 0.8 MPa to about 1.35 MPa, alternatively about 0.9 MPa to about 1.3 MPa, alternatively about 0.95 MPa to about 1.25 MPa, when measured by the tensile strength test method described herein. In some cases, a yield tensile strength value that is too low may indicate that the copolymers and adhesive compositions containing the copolymers are too weak to provide sufficient tensile strength to the product during use. Alternatively, in some cases, a yield tensile strength value that is too high may indicate that the copolymers and adhesive compositions containing the copolymers are too hard to adequately absorb the stresses applied to the copolymers and adhesive compositions containing the copolymers during use of the product.

[0037] The copolymers, and adhesive compositions including the copolymers, can exhibit surprisingly high values ​​in the Static Peel Time Test Method described herein, as shown below in Table 2. The copolymers, and adhesive compositions including the copolymers, can have a static peel time of at least 220 seconds, alternatively at least 230 seconds, alternatively from about 220 seconds to about 750 seconds, alternatively from about 225 seconds to about 600 seconds, alternatively from about 230 seconds to about 500 seconds, alternatively from about 230 seconds to about 400 seconds, alternatively from about 235 seconds to about 350 seconds, when measured by the Static Peel Time Test Method described herein, when performed using a 40 mm wide test sample having a 25 gram weight and a coat weight of about 2.2 gsm.

[0038] The copolymers and adhesive compositions containing the copolymers may have a penetration of about 10 decimeters to about 35 decimeters, alternatively about 15 decimeters to about 30 decimeters, alternatively about 17 decimeters to about 21 decimeters, as measured by the penetration test method described herein. In some cases, a penetration value that is too high may indicate that the copolymers and adhesive compositions containing the copolymers are too soft and do not provide sufficient bond strength to the product, causing cohesive failure of the adhesive composition in the bond. Alternatively, in some cases, a penetration value that is too low may indicate that the copolymers and adhesive compositions containing the copolymers are too hard and cannot adequately absorb the stresses applied to the copolymers and adhesive compositions containing the copolymers during use of the product.

[0039] The copolymer and adhesive compositions containing the copolymer have a viscosity of about 0.4 g / cm at 150°C. 3 ~Approx. 0.87g / cm 3 , or about 0.5 g / cm 3 ~Approx. 0.85g / cm 3 , or about 0.7 g / cm 3 ~Approx. 0.85g / cm 3 , or about 0.75 g / cm 3 ~about 0.85g / cm 3 , or about 0.8 g / cm 3 ~Approx. 0.85g / cm 3 The density of the sintered body may be 0.01 to 0.01.

[0040] It has been found that adhesive compositions without tackifiers generally have a density about 10% lower than tackifier-containing adhesive compositions known in the art, since tackifiers typically have a density of about 1 g / cm3, which is higher than the density of the other adhesive components. 3 This is because it has a density of

[0041] It has been found that it is the volume of the adhesive layer in the laminate, and not the mass of the adhesive layer, that determines the bond strength of the laminate, which can be measured, for example, as "static peel". Without being bound by theory, it is believed that this is due to structural mechanics laws that suggest that a higher stress concentration occurs in a thinner adhesive layer during deformation. This makes the thinner adhesive layer more likely to break when a peel or shear force is applied to the laminate. To allow for a stronger bond in the laminate, the adhesive layer typically has a larger thickness.

[0042] As described herein, adhesive compositions with lower densities allow for the same quality bond to be achieved with less mass of adhesive. Because it is the mass usage, and not the volume usage, that determines all commercially relevant aspects of a sanitary adhesive (e.g., material costs or shipping costs, etc.), adhesives with lower densities allow for significant commercial advantages.

[0043] Three adhesive material properties - storage modulus, yield stress, and toughness (all at 37°C) are believed to be predictive of bond strength performance of laminates containing the adhesive compositions described herein.

[0044] It is believed that the bond strength performance of the laminate will be maximized at these properties, and it is possible to define preferred operating ranges with upper and lower limits for these properties that will predict the bond strength performance of the laminate.

[0045] Storage modulus represents the elastic resistance of adhesive composition to small deformation.Without being bound by theory, it is believed that the failure mechanism that finally breaks the bond is initiated by the cracking inside the adhesive layer close to the interface with the substrate (film or nonwoven), followed by the crack propagation.It is also believed that this failure mechanism is already initiated by small mechanical deformations, for example, described by engineering strains smaller than 10% or even smaller than 1%.

[0046] Adhesive compositions with lower storage modulus are less resistant to these small strain deformations and are better able to redirect mechanical stress away from the interface and into the bulk of the adhesive, or in other words towards the center of the adhesive layer. The bulk of the adhesive layer can then undergo "plastic yielding", a mechanism that very effectively absorbs the energy of deformation and thereby prevents the bond from breaking. This mechanism is also called "energy dissipation". The mechanical energy is converted into heat while the bond remains generally intact. In the "static peel time" test, a laminate with an adhesive composition with a lower storage modulus can hold a weight for a longer period of time before the bond breaks and the weight falls. Therefore, there is an upper limit to the storage modulus.

[0047] It is also believed that there is a lower limit to the storage modulus: if the adhesive composition offers too little elastic resistance to such deformation, the laminate will also have poor bond strength performance, e.g., too low a static peel time.

[0048] Without wishing to be bound by theory, it is believed that the same reasoning applies to the yield stress: too high a yield stress will prevent effective energy dissipation, while too low a yield stress will result in the adhesive offering too little resistance to deformation.

[0049] Surprisingly, a similar behavior was found for the "toughness" parameter.

[0050] The adhesive formulations described herein provide excellent ranges in three material parameters, thereby enabling the desired mechanical performance of the laminate.

[0051] It has been found that the development of a laminate comprising a nonwoven fabric, an adhesive composition, and a rigid polyethylene film as described herein is typically more challenging than the development of a laminate comprising two nonwoven fabrics and an adhesive composition. This is believed to be due to the more or less flat surface of the film (compared to the fibrous structure of the nonwoven fabric) which can reduce mechanical entanglement. Furthermore, the rigid nature of the polyethylene film is believed to contribute less to energy dissipation at the interface between the film and the adhesive composition. Thus, the adhesive composition described herein that works well in an adhesive-rigid film laminate typically also works well in a nonwoven-nonwoven laminate.

[0052] The copolymers, as well as adhesive compositions including the copolymers, may have a storage modulus at 37° C. of from about 3 MPa to about 9.5 MPa, alternatively from about 4.5 MPa to about 9.5 MPa, alternatively from about 5 MPa to about 9.25 MPa, alternatively from about 5.5 MPa to about 9.1 MPa, as measured by the Oscillatory Rheometry Test described herein.

[0053] The copolymers, as well as adhesive compositions including the copolymers, may have a yield stress at 37° C. of from about 0.8 MPa to about 1.45 MPa, alternatively from about 0.9 MPa to about 1.4 MPa, alternatively from about 1 to about 1.4 MPa, when measured by the Elongation Test Method described herein.

[0054] The copolymer, as well as adhesive compositions containing the copolymer, have a stretch strength of about 2 MJ / m at 37° C. as measured by the Elongation Test Method described herein. 3 ~about 8MJ / m 3 , or about 2 MJ / m 3 ~about 6MJ / m 3 , or about 2 MJ / m 3 ~about 5MJ / m 3 , or about 2 MJ / m 3 ~about 4MJ / m 3 , or about 2.4 MJ / m 3 ~about 4MJ / m 3 The toughness of the material may be as follows:

[0055] Optional Ingredients The adhesive compositions described herein may contain less than 10% by weight, alternatively less than 5% by weight, alternatively less than 3% by weight, alternatively less than 2% by weight, alternatively less than 1% by weight, alternatively less than 0.5% by weight, alternatively less than 0.3% by weight, alternatively less than 0.2% by weight, alternatively less than 0.1% by weight, alternatively less than 0.05% by weight of one or more optional ingredients.

[0056] The adhesive composition may optionally contain a plasticizer or plasticizing oil or extender oil that can reduce the viscosity of the adhesive composition or improve the adhesion properties. Non-limiting examples of plasticizers include olefin oligomers, low molecular weight polyolefins, such as liquid polybutene, low molecular weight non-aromatic polymers (e.g., REGALREZ 101 from Eastman Chemical Company), phthalates, mineral oils, such as naphthenic, paraffinic, or hydrogenated (white) oils (e.g., Kaydol oil or ParaLux oil (Chevron USA Inc.)), vegetable and animal oils and their derivatives, petroleum-derived oils, and combinations thereof. Plasticizers may include polypropylene, polybutene, hydrogenated polyisoprene, hydrogenated polybutadiene, polypiperylene, copolymers of piperylene and isoprene, as described in U.S. Pat. No. 8,865,824, which is expressly incorporated by reference.

[0057] The adhesive composition may optionally include an antioxidant or stabilizer. Any antioxidant known to one of ordinary skill in the art may be used in the adhesive composition. Non-limiting examples of suitable antioxidants include amine-based antioxidants such as alkyldiphenylamines, phenyl-naphthylamines, alkyl or aralkyl substituted phenyl-naphthylamines, alkylated p-phenylenediamines, tetramethyl-diaminodiphenylamines, and hindered phenolic compounds such as 2,6-di-t-butyl-4-methylphenol; 1,3,5-trimethyl-2,4,6-tris(3',5'-di-t-butyl-4'-hydroxybenzyl)benzene; tetrakis[(methylene(3,5-di-t-butyl-4-hydroxyhydrocinnamate)]methane (e.g., IRGANOX™ 1010, manufactured by Ciba Geigy, New York); octadecyl-3,5-di-t-butyl-4-hydroxycinnamate (e.g., IRGANOX™ 1076, manufactured by Ciba Geigy, New York); Geigy), as well as combinations thereof. If used, the amount of antioxidant in the composition can be less than 1 wt.%, alternatively from about 0.05 wt.% to about 0.75 wt.%, alternatively from about 0.1 wt.% to about 0.5 wt.%, of the total weight of the adhesive composition.

[0058] The adhesive composition may optionally include a UV stabilizer that can prevent or reduce the degradation of the composition due to radiation. Any UV stabilizer known to those skilled in the art may be used in the adhesive composition. Non-limiting examples of suitable UV stabilizers include benzophenones, benzotriazoles, aryl esters, oxanilides, acrylic esters, formamidine carbon black, hindered amines, nickel quenchers, hindered amines, phenolic antioxidants, metal salts, zinc compounds, and combinations thereof. If used, the amount of UV stabilizer in the adhesive composition may be less than 1 wt.%, alternatively from about 0.05 wt.% to about 0.75 wt.%, alternatively from about 0.1 wt.% to about 0.5 wt.%, of the total weight of the adhesive composition.

[0059] The adhesive composition may optionally include a brightener, colorant, and / or pigment. Any colorant or pigment known to one of ordinary skill in the art may be used in the adhesive composition. Non-limiting examples of suitable brighteners, colorants, and / or pigments include fluorescent materials and pigments such as triazine-stilbenes, coumarins, imidazoles, diazoles, titanium dioxide and carbon black, phthalocyanine pigments, and other organic pigments such as IRGAZINB, CROMOPHTALB, MONASTRALB, CINQUASIAB, IRGALITEB, ORASOLB, all available from Ciba Specialty Chemicals, Tarrytown, NY. If used, the amount of brightener, colorant, and / or pigment in the adhesive composition may be less than 10% by weight, alternatively from about 0.01% to about 5% by weight, alternatively from about 0.1% to about 2% by weight of the total weight of the adhesive composition.

[0060] The adhesive composition may optionally include a fragrance, such as a perfume or other odorant. Such a fragrance may be carried by the liner or may be contained in a release agent, such as, for example, microcapsules, which may release the fragrance when the release liner is removed from the adhesive composition or when the adhesive composition is squeezed.

[0061] The adhesive composition may optionally include a filler. Any filler known to one skilled in the art may be used in the adhesive composition. Non-limiting examples of suitable fillers include sand, talc, dolomite, calcium carbonate, clay, silica, mica, wollastonite, feldspar, aluminum silicate, alumina, hydrated alumina, glass beads, glass microspheres, ceramic microspheres, thermoplastic microspheres, baryte, wood flour, and combinations thereof. If used, the amount of filler in the adhesive composition may be less than 60% by weight, alternatively from about 1% to about 50% by weight, alternatively from about 5% to about 40% by weight of the total weight of the adhesive composition.

[0062] Purpose The adhesive compositions described herein find industrial application in sanitary disposable consumer articles, such as diapers, feminine care pads, and napkins. The articles may include any item having two or more substrates adhesively bonded by the hot melt adhesive composition, such as disposable articles, such as diapers or feminine napkins. Substrates may include thermoplastic materials, thermosetting polymers, polyesters, polyethylene terephthalates, polyamides, nylons, polypropylenes, and combinations, blends, or layered composites thereof. The substrates may optionally include coatings of waxes, acrylate polymers, or other materials, colorants, preservatives, stabilizers, processing lubricants, and combinations thereof. The substrates may include solid, non-porous, or breathable films. The substrates may optionally include nonwoven fabrics and films (e.g., polyethylene films).

[0063] The adhesive composition can be used as a structural adhesive in the assembly of commonly available consumer disposable articles. Such articles include baby diapers, adult diapers, bed pads, sanitary products, and other absorbent articles. Typically, these articles are made by combining at least a polymer film with other films and fibrous materials. The fibrous materials can include fabrics such as woven or nonwoven fabrics, fiber batts, fiber aggregates, fibers in the form of fiber balls, and the like.

[0064] Such absorbent articles typically include an absorbent held within the article. The absorbent is usually covered using a nonwoven inner liner. Such liners include highly permeable materials, such as spunbond nonwoven structures, that allow fluid or moisture to pass from the interior of the article to the absorbent layer. The absorbent layer or structure formed within the absorbent article typically includes a fiber mass pad or cellulose or wood pulp for the purpose of absorbing liquid or fluid materials discharged into the absorbent article. The fibers or fluff may include cellulose fibers, synthetic fibers, or mixtures thereof, such as wood fibers, cellulose fibers, polyethylene fibers, polypropene fibers, or blends of other fibrous materials, often including superabsorbent materials. To increase the absorption capacity of the absorbent article, superabsorbent or superabsorbent materials are used. Such materials are organic materials, including modified natural rubbers and resins, but often include synthetic polymeric materials, such as hydrogels. Carboxymethylcellulose, alkali metal salts of acrylic polymers, polyacrylamides, polyvinyl alcohol, polyethylene anhydride polymers and copolymers, polyvinyl ether polymers and copolymers, hydroxyalkyl cellulose polymers and copolymers, polyvinyl sulfonic acid polymers and copolymers, polyacrylic polymers, polyvinylpyrrolidone polymers and copolymers can be used for the absorption function.

[0065] The nonwoven layers used in such disposable articles are typically generally planar structures comprising a bonded assembly of natural or synthetic fibers.

[0066] Such nonwoven materials are often made using a variety of techniques including spunbond, meltbond, etc. Such nonwoven materials are often manufactured by randomly laying down fibers or rovings in a random pattern and then thermally bonded using the inherent bonding properties of the fibers or by bonding the fibers using a resin material applied to the fibers. A variety of polymers can be used to make the nonwoven materials including polyolefins, polyesters, ethylene vinyl acetate polymers, ethylene acrylic acid polymers, etc.

[0067] The outside of the article often comprises a liquid-impermeable polymeric film. In certain embodiments, the outer polymeric film can be further modified using additional outer layers to impart more cloth-like or nonwoven characteristics to the outer polymeric film. The outer film typically comprises a single layer of polymeric film, but may be a multi-layer film structure. Typical polymeric sheet materials include high tensile strength polymers, including polyester, polyolefin, or other thermoplastic sheet materials that can be formed into film layers. Polyolefin or polyester polymeric materials are often formed into sheets and treated to improve strength, flexibility, and puncture resistance. Film properties of the polymeric film can be improved by techniques including biaxial orientation, heat treatment, or surface treatment. Such polymeric films often have a thickness ranging from about 0.5 mils (e.g., thousandths of an inch) to about 1.5 mils.

[0068] The absorbent article may include a liquid impermeable polymeric film, an absorbent layer pad, and a nonwoven inner layer. The three-component structure may be assembled using an adhesive composition that is applied using manufacturing techniques that adhere the nonwoven inner layer to the polymeric film while holding the absorbent layer therebetween.

[0069] A manufacturing method using the adhesive composition includes applying a molten adhesive composition to a substrate, and then contacting the adhesive composition with a second substrate within 0.1 to 5 seconds after applying the adhesive composition to the first substrate, whereby the substrates are adhesively bonded together.

[0070] In articles made using the adhesive composition, the article can be made by forming an adhesive bond between a polymer film and a fiber or fiber mass. The article may also include an adhesive bond formed between a polymer film and a nonwoven. Additionally, the article can be made by forming an adhesive bond between a multi-layer structure that includes an outer layer of a polymer film and an inner component that includes a fiber map or nonwoven.

[0071] The adhesive composition may be applied to a substrate as a hot melt adhesive under molten conditions, or may be coated, spread, or sprayed onto a polymer film nonwoven or absorbent pad. Spray-on adhesives are typically applied using slot coat, spray-on, or spray characteristics in a bead, dot pattern, spiral pattern, or other conventional pattern using such Nordson application technology. The adhesive composition may also be applied to a substrate using a slot coat at higher machine speeds (using a Nordson True Coat or Speed ​​Coat slot).

[0072] The adhesive composition is preferably used in an amount of about 1 to about 25 grams per square meter (gm -2 The adhesive composition can be used in elastic attachment of disposable diaper and napkin constructions, and disposables, with particularly preferred applications including baby diaper construction, diaper chassis construction, diaper core stabilization, diaper outer cover lamination, feminine napkin core stabilization, and feminine napkin construction bonding.

[0073] Test Method Static Peel Time Test Method The static peel time of a hot melt adhesive composition is determined by using a static peel time test method, which consists of first forming a bond between two specified substrates using a hot melt and a specified slot coating process to form a laminate, as described below. Then, a test specimen extracted from the substrate is subjected to a 180 degree peel test under a static load, and the average time to failure is reported as the "static peel time".

[0074] Preparation of the laminate Two of the specified substrates are attached using a hot melt adhesive composition by a specified slot coating process to form a laminate. The first substrate used to form the laminate, a "nonwoven," has a dot bond pattern (diamond, 0.87 mm per dot bond) covering 18.6% of the bond area and having 21.5 dots per square centimeter. 2 ) of 15 gsm polypropylene spunbond (SSS). The average fiber diameter is 17 micrometers. The nonwoven is provided in roll stock form and is 212 mm wide. The second substrate, "film", used to form the laminate is a microporous polyethylene film with a basis weight of 16 gsm. The average print coverage is 16.7%. Exemplary suitable films are MICROPRO microporous films and films designated BR137P and BR137U, or equivalents, available from Clopay (Clopay Plastics Corporation, Mason, Ohio, USA). The film is provided in roll stock and is 206 mm wide.

[0075] The hot melt adhesive composition is slot coated onto a moving nonwoven web. The nonwoven web speed is 573 m / min and the total nonwoven web tension at the application point is 0.5 lbs (10.5 N / m tension per unit width). A Nordson TrueCoat™ die (Nordson LU12K04139 / 8138208, Nordson Corporation, Westlake, OH, USA, or equivalent) is used to slot coat the adhesive onto the nonwoven. The die shim is 0.3 mm thick and cut in an alternating pattern to form 60 openings, each 1 mm wide, with a 1 mm wide gap between each opening. This results in a coating of 60 continuous stripes of adhesive in the machine direction, each stripe of adhesive being 1 mm wide, with a 1 mm uncoated gap between the adhesive stripes. The nozzle adhesive flow rate is set so that each adhesive stripe has a basis weight of 2.2±0.1 gsm. The adhesive is maintained at a temperature of 150±5° C. all the way to the applicator. The entire slot coating process is carried out at an ambient temperature of 21±2° C.

[0076] Adhesive is applied to the nonwoven web with a slot coat die by contacting the nonwoven web, which is supported between two non-driven web-supporting idlers that co-rotate with the moving nonwoven web and each have a diameter of 57 mm, with the slot coat die. The spacing of the web-supporting idlers is set at 155 mm center-to-center and the exit of the adhesive applicator is set at a point 7 mm from the center of the downstream idler. The applicator is forced into the nonwoven web between the idlers such that at the exit point of the adhesive the nonwoven deviates 3-4 mm from the slot coat die relative to the plane created by the nonwoven web under tension when the applicator is not present. The angle formed between the shim plane of the slot coat die and the plane of the nonwoven web under tension when the applicator is not engaged is the pitch angle. This angle is described as zero when the planes are perpendicular to each other. For the laminate, the adhesive was coated at a pitch angle of +3° toward the downstream idler. In other words, the plane of the shim relative to the plane of the tensioned nonwoven when the applicator is not engaged is 87° on the side of the downstream idler.By centering the width of the slot coat die over the width of the nonwoven, it centers the adhesive coating along the length of the nonwoven web.

[0077] The adhesive coated nonwoven web is then contacted with the film approximately 970 mm after coating. The web speed of the film is 573 m / min and the total web tension of the film is 1.0 lbs (21 N / m tension per unit width). The contact point between the two webs is made at an idler with a diameter of 57 mm and the webs are wrapped around the idler with a wrap angle of 190°. The combined webs are wound onto a roll with a winding tension of 1.5 lbs and the samples are immediately cut from the roll after winding. The removed samples are equilibrated at 21±2° C. and 40% relative humidity for a minimum of 20 hours before static peel testing.

[0078] Peeling under static load Randomly remove test specimens from the equilibrated laminate, 40 mm in the machine direction of the laminate, and across the cross-machine length of the strip, so that all 60 1 mm wide stripes of slot coated hot melt adhesive composition are included.

[0079] Static peel is performed in the direction transverse to the machine direction (e.g., perpendicular to the adhesive stripe direction). At one 40 mm wide edge of the laminate test specimen, each unbonded layer of the edge of the laminate is folded separately onto a small round wooden dowel rod with a diameter of 2 mm and a length of about 40 mm, and the wrapped dowel is secured with a 2-inch wide double clip. A clip is placed on the wrapped dowel and secured to the double-folded layer of material so that the material cannot slip or slip out of the clip. With the clip attached, the specimen is placed in a preconditioned incubator (37±1° C.) for about 10 minutes before testing. After 10 minutes, each sample is hung in the chamber by the clip attached to the film layer, and a weight is attached to the nonwoven clip hanging from it. The total weight of the hanging weight, double clip, and dowel is 25 grams. The specimen is hung so that the bottom of the attached weight is located high enough above the bottom of the chamber so that the entire laminate can peel off and the weight can fall freely to the bottom of the chamber through some remaining distance. A timer is used to measure the time between the time the hanging weight is attached and the time the bonded area of ​​the test laminate completely delaminates. This time to failure is recorded to the nearest second for each specimen. Peeling under static load is performed on at least 10 specimens and the arithmetic mean of the times to failure is defined as the "static peel time" and is reported to the nearest second.

[0080] Penetration test method The penetration of hot melt adhesive compositions is determined using a penetration test method consisting of performing ASTM D5 / D5M-13 using a Humboldt H1280 needle and the following additional guidelines: Ambient temperature is maintained at 21.5±1.0°C and specimens of the hot melt adhesive composition being tested are allowed to thermally equilibrate before measurement. A total load of 100 g is used as described in Section 6 of ASTM D5 / D5M-13, with an allowable penetration time of 5.0±0.2 seconds. The arithmetic mean of the penetration distances of three replicates is defined as "penetration" as described in Section 10 of ASTM D5 / D5M-13 and is reported in tenths of a millimeter (i.e., decimillers or dmm) to the nearest integer value of dmm.

[0081] Tensile Strength Test Method The tensile strength of the hot melt adhesive composition is determined using a tensile strength test method consisting of carrying out ASTM / D638-14 with the following additional guidelines: The ambient temperature is maintained at 23.0±1.0°C. The hot melt adhesive composition is cast into a shape consistent with a Type IV "dogbone" as described in Figure 1 of ASTM D638-14 and allowed to equilibrate to ambient temperature. The test proceeds at a crosshead speed of 50 mm / min. The yield tensile strength is calculated as described in Section 11.2 of ASTM D638-14 and reported as "Yield Tensile Strength" in megapascals (MPa) to the nearest 0.01 MPa.

[0082] Viscosity Test Method The viscosity parameters of hot melt adhesive compositions are determined using the Viscosity Parameters Test Method, which consists of implementing ASTM / D3236-15 with the following additional guidelines: A Brookfield RVT Viscometer or equivalent with spindle SC 4-27 (Brookfield Engineering, Middleboro, MA, USA) is used. The sample temperature is maintained at 150.0±1.0°C throughout the measurement. The sample is preheated for 10 minutes and stirred with the measuring spindle for 30 minutes. The spindle is rotated at 20 rpm throughout the measurement. The resulting apparent viscosity is reported as "Viscosity" in millipascal-seconds to the order of 100 mPa·s as described in Section 10.

[0083] Mettler Cup and Ball Test Method Mettler cup and ball parameters are determined using the Mettler cup and ball test method which consists of performing ASTM D3461-14 at a heating rate of 2° C. / min heating. The softening point as defined in ASTM D3461-14 is recorded and reported to the nearest 0.1° C. for the Mettler cup and ball parameters.

[0084] Melting Enthalpy Test Method The melting enthalpy of hot melt adhesive compositions is determined using the melting enthalpy test method, which consists of carrying out ASTM / D3418-15 with the following additional guidelines: Preferably, the test specimen is extracted from the adhesive composition in molded or pelletized raw material. If the raw material is not available, the adhesive test specimen is extracted from the joint of interest in the absorbent article using techniques known to those skilled in the art. In the differential scanning calorimeter (DSC), dry nitrogen is used as the purge gas. The heating rate in the DSC is 10° C. / min, and the cooling rate in the DSC is 1° C. / min. The mass-normalized melting enthalpy is calculated based on the curve corresponding to the cooling (1° C. / min) as specified in section 11.4, and is reported as "melting enthalpy" in units of Joules / gram (J / g) to the nearest 0.1 J / g.

[0085] Oscillatory Rheometry Test Method The oscillatory rheometry test method is used to measure the storage modulus and loss factor of hot melt adhesive compositions. A controlled stress rotational rheometer (such as a Discovery HR-3, TA Instruments (New Castle, DE, USA) or equivalent) is capable of temperature control of the sample (using a combination of a Peltier cooler and a resistive heater) to an accuracy of 0.5°C or better over a range of at least -10°C to 150°C. The rheometer is operated in a parallel plate configuration using a 20 mm stainless steel parallel plate tool.

[0086] In this method, a parallel plate gap of 1000 μm is used initially. To compensate for the thermal expansion of the tool, the gap is set to 1000 μm and a mapping of the actual plate gap (as measured using a suitable standard test fluid), a function of temperature over the range -10° C. to 150° C. is then performed. This mapping is then used throughout the determination of the storage modulus and loss factor parameters.

[0087] The rheometer is heated to 150°C, the hot melt adhesive composition is introduced into the rheometer, the gap is set to 1050 μm, the overhanging sample is trimmed, and then the gap is set to 1000 μm. (The axial force control of the rheometer is set to maintain within ±0.1 N force, and in addition to the tooling compensation mentioned above, the thermal expansion / contraction of the sample itself is compensated for to avoid overfilling or underfilling the gap.) The rheometer is then allowed to cool to 130°C, at which point measurements are started at a temperature ramp from 130°C to -10°C at a constant cooling rate of 2°C / min. The applied strain amplitude is 0.1% and the oscillation frequency is 1 Hz (i.e., 1 cycle per second). The resulting oscillatory stress is recorded.

[0088] After this step, the sample temperature is set to 23° C. (ramp to this set point at a rate of 10° C. / min) and the sample is allowed to stand for 4.0 hours at 23° C. At the end of this period, the temperature is set to −10° C. (ramp to this set point at a rate of 10° C. / min), the sample is equilibrated at −10° C. for 300 seconds, and a second oscillatory rheology measurement is performed while increasing the temperature to 130° C. at a constant heating rate of 2° C. / min (0.1% strain, 1 Hz oscillatory frequency).

[0089] From the second temperature sweep, the storage modulus G' was calculated and recorded at 23° C. and 37° C., and these values ​​are reported in megapascals (MPa) to the nearest 0.01 MPa as "Storage Modulus at 23° C." and "Storage Modulus at 37° C.," respectively. From the second temperature sweep, the loss factor (also known as tan delta) was calculated and recorded at 23° C. and 37° C., and these dimensionless values ​​are reported to the nearest hundredth as "Loss Factor at 23° C." and "Loss Factor at 37° C.," respectively.

[0090] Elongation test method The tensile test method is used to determine the yield stress and toughness of test specimens of the adhesive composition. Thin film test specimens formed from the adhesive composition are analyzed in a rotational rheometer equipped with a special fixture with counter-rotating rollers to measure and record the stress associated with the applied tensile strain.

[0091] Equipment setup The rotational rheometer (ARES G2, TA Instruments, New Castle, DE, USA, or equivalent) is equipped with a fixture with counter-rotating cylindrical rollers specifically designed to control the tensile deformation of the film. An example of a suitable fixture is the Extensional Viscosity Fixture, or EVF (EVF, TA Instruments, or equivalent). The rheometer is further equipped with a forced convection oven FCO (FCO, TA Instruments, or equivalent) capable of controlling the temperature from at least -50 to 250°C within a tolerance of 0.5°C, and a cooling system (ACS2, TA Instruments, or equivalent).

[0092] Preparation of test specimens Approximately 10 g of the adhesive composition is placed in a polytetrafluoroethane (PTFE) bowl and introduced into a vacuum oven. After 15 minutes at 170°C at ambient pressure, the pressure is reduced to 10 mbar, and the adhesive composition is subsequently held at 170°C and 10 mbar for 45 minutes to remove air bubbles from the adhesive composition. The adhesive composition is removed from the vacuum oven and allowed to cool to ambient laboratory conditions (23±2°C) over a period of 90±30 minutes, at which point the adhesive composition is removed from the PTFE bowl and placed between two sheets of siliconized paper. A 0.50 mm thick metal shim is used as a spacer in the heated press to obtain a film thickness of 0.50 mm when pressed in the heated press at 90°C for 60 seconds at a pressure sufficient to form a polymer film. If 90°C is insufficient to melt the adhesive composition, a higher temperature (but a minimum temperature sufficient to melt the composition) is used. The film is stored in the laboratory at 23±2°C for at least 120 hours before testing. Individual specimens for measurement are die cut from the film using a sample cutter to final specimen dimensions of 20.0 mm x 10.0 mm x 0.50 mm.

[0093] measurement The EVF cylinder is heated to 50° C. for 90±30 seconds in the forced convection oven of the rheometer. A test piece of the adhesive composition is quickly pressed onto the EVF cylinder to fix it to the cylinder surface. The test piece is positioned perpendicular to the axis of rotation of the cylinder.

[0094] The specimen mounted on the EVF was then placed in the forced convection oven of the rheometer for thermal conditioning and maintained isothermal at 37±1°C for 300±10 seconds. After this time has elapsed, the specimen is mechanically conditioned. To mechanically condition the specimen, the torque transducer is zeroed and the sample is torqued for 0.001 s. -1 The specimen is placed under a pre-extension rate of 0.30 seconds and then allowed to relax for 60 seconds. (In this method, all strains are expressed in terms of Hencky strain, also known as "true strain" or "logarithmic strain.")

[0095] The measurements are carried out in an FCO oven at 37°C ± 0.5°C. The strain rate for the measurements is 1s -1 and the strain at maximum elongation is 4.0. After the measurement, the specimen is inspected for rupture. If there is a rupture, the location of the rupture is recorded. If the rupture is approximately centered between the two cylinders of the EVF, the collected data is considered acceptable. Otherwise, if the polymer film rupture is at or near the rotating cylinder, the results are discarded and measurements are performed again on a duplicate specimen.

[0096] analysis A constant volume is assumed for the calculation of the extensional stress. From the raw torque vs. angular displacement data recorded by the rheometer, the extensional stress (megapascals or MPa) vs. Hencky strain data is calculated. The data is plotted in a semi-logarithmic fashion with Hencky strain on the abscissa (linear scale) and extensional stress on the ordinate (logarithmic scale). In this plot, the linear range is sought. The linear range can be identified and is known as the R 2 If values ​​can be fitted to a positive slope of 0.98 or greater, the value of the fitted line at zero Hencky strain (i.e., the y-intercept) is defined as the yield stress, which is reported in Mpa to the kilopascal order. Otherwise, the maximum value of tensile stress recorded during the measurement is reported as the yield stress, also reported in Mpa to the kilopascal order.

[0097] The tensile stress (MPa) versus Hencky strain data calculated above is plotted again, this time in a linear fashion with Hencky strain on the abscissa (linear axis) and tensile stress on the ordinate (linear axis). The integral of the tensile stress with strain (i.e., the area under the tensile stress curve as a function of strain) is calculated from zero strain to the strain at which the sample breaks (or to a strain of 4.0 if it does not break during the measurement) and is reported as toughness, which is expressed in megajoules per cubic meter or MJm. -3 It is reported in units of EXAMPLES

[0098] The following examples are provided to help illustrate the adhesive compositions herein. The illustrated adhesive compositions can be prepared by conventional compounding and mixing techniques. It will be understood that other variations of the adhesive compositions described herein can be made within the scope of those skilled in the art of formulation. All parts, percentages, and ratios herein are by weight unless otherwise specified. Some components may be provided as dilute solutions by the supplier. The amounts stated represent the weight percent of active material unless otherwise specified.

[0099] Table 1 provides exemplary adhesive compositions and provides component descriptions and ranges of component amounts.

[0100] [Table 1]

[0101] data Table 2 shows exemplary and comparative adhesive compositions.

[0102] [Table 2]

[0103] Adhesive compositions A-Q include exemplary adhesive compositions and comparative adhesive compositions. Each adhesive composition A-Q includes at least 99% of one copolymer, which varies, with each copolymer including from about 50% to about 60% 1-butene monomer units and from about 40% to about 50% propene monomer units. During some testing, less than 1% antioxidants and other minor ingredients were added for preservative and packaging purposes, but the 1% antioxidants and other minor ingredients are not believed to have an effect on the data provided in Tables 2 and 3.

[0104] Table 3 provides additional parameters associated with a select group of exemplary adhesive compositions and comparative adhesive compositions of Table 2.

[0105] [Table 3]

[0106] Dimensions and values ​​disclosed herein should not be understood as being strictly limited to the exact numerical values ​​recited. Instead, unless otherwise indicated, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as "40 mm" is intended to mean "about 40 mm."

[0107] All documents cited in this application, including all cross-referenced or related patents or patent applications, and any patent applications or patents to which this application claims priority or benefit, are incorporated herein by reference in their entirety, unless expressly stated to the contrary. The citation of any document shall not be deemed to be prior art to any application disclosed or claimed herein, or to teach, suggest or disclose any such application, either alone or in combination with any other reference. Furthermore, to the extent that any meaning or definition of a term in this document conflicts with a meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.

[0108] Although the adhesive composition has been illustrated and described herein, it would be apparent to one skilled in the art that various other changes and modifications can be made therein without departing from the spirit and scope of this document. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this document.

Claims

1. 1. A hot melt adhesive composition comprising a copolymer, a. Having a viscosity of 2,000 mPa·s to 11,500 mPa·s at 150°C when measured by the Viscosity Test Method; b. has a storage modulus of 3 MPa to 9.5 MPa at 37° C. as measured by the Oscillatory Rheometry Test Method; c. having a yield stress of 0.8 MPa to 1.45 MPa at 37° C. as measured by the Elongation Test Method; The hot melt adhesive composition does not contain a tackifier and comprises at least 95% by weight of a copolymer containing 30% to 70% by weight of propene monomer units and 30% to 70% by weight of 1-butene monomer units.

2. 10. The hot melt adhesive composition of claim 1 having a static peel time of at least 220 seconds as measured by the Static Peel Time Test Method.

3. 3. The hot melt adhesive composition according to claim 1 or 2, wherein the viscosity of the adhesive composition is less than 7,000 mPa·s at 150°C.

4. The hot melt adhesive composition according to any one of claims 1 to 3, wherein the viscosity of the adhesive composition is from 4,000 mPa·s to 6,500 mPa·s at 150°C.

5. 5. The hot melt adhesive composition according to any one of claims 1 to 4, having a penetration of 10 to 35 decimeters as measured by the penetration test method.

6. 2 MJ / m at 37° C. when measured by the extension test method ３ ~8MJ / m ３ The hot melt adhesive composition according to any one of claims 1 to 5, having a toughness of

7. The hot melt adhesive composition according to any one of claims 1 to 6, which is free of heterophasic copolymers.

8. 0.5 g / cm at 150°C ３ ~0.85g / cm ３ The hot melt adhesive composition according to any one of claims 1 to 7, having a density of

9. The hot melt adhesive composition according to any one of claims 1 to 8, wherein the adhesive composition has a storage modulus of 5 MPa to 9.5 MPa at 37°C.

Images