Hot melt adhesive composition

Abstract

The invention extends to a method of producing the hot melt adhesive composition, a method of producing a laminate comprising the hot melt adhesive composition, a laminate produced using the hot melt adhesive composition and thus comprising the hot melt adhesive composition, the use of the laminate in sanitary applications, and the use of the hot melt adhesive composition as an adhesive for laminates. [Solution] The present invention relates to a hot melt adhesive composition comprising 20 to 70 wt. % of a polymer, 1 to 15 wt. % of a hydrocarbon wax, and in addition to the hydrocarbon wax, an alcohol and / or a carboxylic acid, 20 to 70 wt. % of a resin, and optionally additives including an antioxidant and / or a processing oil.

Description

[Technical field]

[0001] TECHNICAL FIELD TO WHICH THEINVENTION BELONGS The present invention relates to adhesive compositions, in particular to hot melt adhesive (HMA) compositions. [Background technology]

[0002] background Waxes are known to be used as additives in hot melt adhesive formulations, where they typically function as nucleating agents, diluents, or viscosity reducers. The purpose of using waxes in hot melt adhesive formulations is, among other things, to improve the cure time (i.e., to reduce the cure time, since fast cure times are typically preferred for hot melt adhesives) and to increase the strength of the bond between the substrates. The strength of the bond between the substrates is often measured by the "T-peel" strength.

[0003] As nucleating agents, waxes improve the elongation at break of the polymeric material in the HMA. As diluents, waxes promote the wetting of the adhesive formulation and reduce the (melt) viscosity, which allows for lowering the cost and controlling the application speed of the adhesive. The wax content of the HMA is crucial in terms of improving flexibility and improving wetting due to reduced viscosity.

[0004] Waxes are generally defined as chemical compositions that have a depressed melting point above 40°C, are polishable under slight pressure, are kneadable or brittle at 20°C, are transparent to opaque, do not decompose, melt above 40°C, typically melt between 50-90°C and in exceptional cases up to 200°C, form pastes or gels, and are poor conductors of heat and electricity.

[0005] Waxes can be classified according to various criteria, such as their origin. Here, waxes can be divided into two main groups: natural waxes and synthetic waxes. Natural waxes can be further divided into fossil waxes (e.g., petroleum waxes) and non-fossil waxes (e.g., animal waxes and vegetable waxes). Petroleum waxes can be divided into macrocrystalline waxes (paraffin waxes) and microcrystalline waxes (microwaxes). Synthetic waxes can be divided into partially synthetic waxes (e.g., amide waxes) and fully synthetic waxes (e.g., polyolefin waxes and Fischer-Tropsch waxes).

[0006] Paraffin waxes are derived from petroleum sources. They are clear, odorless, and can be refined for food contact. They contain a range of (mostly) n-alkanes and iso-alkanes as well as some cyclo-alkanes. Raw or crude paraffin wax (slack wax) has many short chain alkanes ("oils") that are removed when refined. Different distributions and qualities of paraffin wax can be obtained. Refining can include deoiling, distillation, and hydrogenation.

[0007] Synthetic Fischer-Tropsch waxes or hydrocarbons resulting from catalytic Fischer-Tropsch synthesis of syngas (CO and H2) to alkanes contain mainly n-alkanes, a few branched alkanes, and essentially no cycloalkanes or impurities, such as sulfur or nitrogen. Instead, the number of olefins and oxygenates (i.e., oxygenated hydrocarbons such as alcohols, esters, ketones and / or aldehydes) may be higher and different from petroleum-based waxes.

[0008] Fischer-Tropsch waxes can generally be classified as low melting (freezing point 20-45°C), medium melting (freezing point 45-70°C), and high melting (freezing point 70-110°C).

[0009] Another source of synthetic waxes are the products resulting from the oligomerization or polymerization of olefin monomers, optionally with subsequent hydrogenation.

[0010] Hydrocarbon waxes are natural or synthetic waxes that contain primarily hydrocarbons. Hydrocarbons are molecules made up of carbon and hydrogen atoms. Unless otherwise specified, "n-" or "linear" refers to straight chain and aliphatic, and "i-", "iso-" or "branched" refers to branched and aliphatic.

[0011] WO 2017 / 0130094 relates to a method for preparing a granulated (pelletized) plasticizer blend, comprising the steps of preparing a mixture of a long-chain branched alcohol and polypropylene, heating said mixture until the melting point of the polypropylene is reached to make it completely fluid, extruding the resulting molten mixture, and chopping the extruded mixture to obtain uniformly sized granules (pellets). The blend thus obtained, a method for plasticizing poly(lactic acid) with this blend, and the plasticized poly(lactic acid) monofilaments or films thus obtained are also disclosed.

[0012] WO 2020 / 049454 relates to hot melt adhesive formulations comprising hydrocarbon waxes that exhibit high T-peel strength and thus allow a reduction in the coating weight and therefore the amount of hot melt adhesive used.

[0013] CN104762032A discloses a hot melt adhesive that can withstand high and low temperatures and is resistant to fats or oils. Aliphatic alcohols are disclosed as lubricants in the manufacture of said hot melt adhesives.

[0014] EP632077A2 and WO1996 / 015170A1 relate to moisture-curable hot melt adhesive compositions containing polyisocyanate-reacted maleated polyolefins. For example, NOVA Guerbet Alcohol 20i™ hydroxyl-functional polyolefin (NOVA Molecular Technologies, Inc.) or Unilin™ 700 (Petrolite Corp.) as linear hydrocarbon alcohols having 50 carbon atoms are disclosed as part of the HMA.

[0015] EP2640791B1 relates to a hot melt adhesive composition comprising (a) a polymer component, (b) a wax, and (c) a templating agent. The templating agent is a sugar or sugar alcohol derivative or has the structure Ar-Ll-X-L2-R, where X is a sugar or sugar alcohol; Ar is a substituted or unsubstituted aryl-containing functional group; R is H, alkyl, alkenyl, hydroxyl, alkoxy and alkyl-halides, or a substituted or unsubstituted aryl-containing functional group; L1 and L2 are independently acetal or ether functional groups.

[0016] DE 10048923 A1 discloses the use of sugar alcohols in the formation of a wax film coating on hot melt adhesive pellets.

[0017] US10793754B2 relates to styrene-isoprene block copolymer HMA containing amorphous wax for hygiene products, where the wax may be modified with carboxylic acids or carboxylic acid anhydrides.

[0018] A suitable test to characterize hot melt adhesives is Dynamic Mechanical Analysis (abbreviated as DMA). It is a technique used to test and characterize the viscoelastic behavior of materials, especially polymers. A sinusoidal stress is applied and the strain in the material is measured, allowing the storage modulus to be determined. The temperature of the sample or the frequency of the stress are often changed, resulting in a change in the storage modulus; this approach can be used to identify the glass transition temperature (Tg) of the material, as well as transitions corresponding to other molecular motions.

[0019] In a purely elastic material, the stress and strain occur in phase, such that the response of one occurs simultaneously with the other. In a purely viscous material, there is a phase difference between the stress and strain, with the strain lagging the stress with a phase lag of 90 degrees (π / 2 radians). Viscoelastic materials exhibit behavior somewhere between purely viscous and purely elastic materials, and exhibit some phase lag in the strain.

[0020] The stress and strain in a viscoelastic material can be expressed using the following equations: Distortion: ε = ε o sin(ωt), Stress: σ = σ0 sin(ωt + δ), Here, ω=2πf, f is the frequency of the strain vibration, t is time, and δ is the phase lag between stress and strain.

[0021] The tensile storage and loss moduli in a viscoelastic material measure the stored energy, which represents the elastic portion, and the energy dissipated as heat, which represents the viscous portion. The tensile storage modulus and loss modulus are defined as follows: Storage: E´=(σ0 / ε0)cosδ Loss:E´´=(σ0 / ε0)sinδ

[0022] Similarly, the shear storage and shear loss moduli G' and G'' are defined. G' reflects the ability of a material to recover from deformation or retain energy, and thus it is an indication of the stiffness / elasticity of the material. "G''" reflects the ability of a material to dissipate energy.

[0023] The ratio between the loss modulus and the storage modulus in a viscoelastic material is defined as tan delta, which provides a measure of damping in the material. Tan delta can also be visualized in vector space as the tangent to the phase angle between the storage and loss moduli. Tensile: tan δ=E´´ / E´ Shear: tan δ = G´ / G´

[0024] For example, a material with a tan delta greater than 1 will exhibit more damping than a material with a tan delta less than 1, i.e. the material is more viscous than elastic. The reason a material with a tan delta greater than 1 will exhibit more damping is because the loss modulus of the material is greater than the storage modulus, meaning that the energy dissipating viscous component of the complex modulus dominates the behavior of the material. The crossover point where tan delta equals 1 indicates the temperature at which the material begins to flow or crystallization / gelling begins to occur, depending on whether the material is heated or cooled. Summary of the Invention [Problem to be solved by the invention]

[0025] Conventional hot melt adhesives cannot simultaneously meet the spray temperature, spray window, or flexibility requirements, at least in sanitary applications.

[0026] Thus, there remains a need to provide hot melt adhesive compositions that have improved flexibility (i.e., lower brittleness or hardness), increased spray window, and reduced spray temperature, but also have fast curing times and acceptable T-peel strength. Such hot melt adhesive compositions are particularly useful for producing laminates, for example, for sanitary applications, including, but not limited to, laminates that include various combinations of layers, including nonwoven layers, polyethylene layers, and / or polypropylene layers, but are also suitable for use in packaging applications, mattress production, etc. [Means for solving the problem]

[0027] Summary of the Invention Hot melt adhesive composition According to the present invention there is provided a hot melt adhesive composition, comprising, based on the total weight of the hot melt adhesive composition: 20-70% by weight of polymer; 1-15% by weight of a hydrocarbon wax and an additive comprising, in addition to the hydrocarbon wax, an alcohol and / or a carboxylic acid; 20-70% by weight of resin; and optionally antioxidants and / or processing oils (processing oils) Includes. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] In this specification, "wt%" is an abbreviation for "weight percentage."

[0029] Therefore, the additives, in addition to the hydrocarbon wax, Alcohol, or Carboxylic acid, or Alcohols and Carboxylic Acids It will be understood that the number of bits may include

[0030] Preferably, the hot melt adhesive composition comprises 30-60 wt.-% of polymer, based on the total weight of the hot melt adhesive composition, i.e. based on the total weight of polymer, additives, resin and, if included, antioxidant and / or processing oil.

[0031] Preferably, the hot melt adhesive comprises 3-15 wt.% of the additive based on the total weight of the hot melt adhesive composition. For example, the hot melt adhesive can comprise 10% to 15% of the additive, for example 10% or 15% of the additive, based on the total weight of the hot melt adhesive composition.

[0032] Preferably, the hot melt adhesive composition comprises 25 to 67% by weight of a resin, based on the total weight of the hot melt adhesive composition.

[0033] The hot melt adhesive composition may contain an antioxidant. In such a case, the hot melt adhesive composition may contain 0 to 5 wt. % of the antioxidant, preferably 0.1 to 2 wt. %, based on the total weight of the hot melt adhesive composition.

[0034] The hot melt adhesive composition may contain a processing oil (processing oil). In such a case, the hot melt adhesive composition may contain 0 to 15 wt. % of the processing oil, preferably 5 to 15 wt. % of the processing oil, based on the total weight of the hot melt adhesive composition.

[0035] The polymer may be a polyolefin polymer.

[0036] The polyolefin polymer may be selected from the group comprising amorphous poly-alpha-olefin (APAO) copolymers, olefin homopolymers, and olefin block copolymers. Preferably, the polyolefin polymer is selected from the group comprising ethylene-propylene copolymers, and ethylene-butene copolymers.

[0037] The polyolefin polymer may be a single polyolefin polymer or a mixture of polyolefin polymers.

[0038] The polyolefin polymer may have a Brookfield viscosity at 190° C., measured according to ASTM D 3236, of 1500 to 20000 mPa·s, preferably 1500 to 7570 mPas.

[0039] The polyolefin polymer may have a ring and ball softening point, measured according to ASTM E 28, of from 90°C to 130°C.

[0040] Polyolefin polymers are 0.8 to 0.9 g / cm 3 The density of the sintered body may be 0.01 to 0.01.

[0041] The additives are added in an amount of: 99 to 30% by weight of a hydrocarbon wax, and 1 to 70% by weight alcohol, or 1 to 70% by weight of a carboxylic acid; or 1 to 70% by weight of alcohol and carboxylic acid may include.

[0042] Preferably, the additive comprises, based on the weight of the additive: 99 to 40% by weight of a hydrocarbon wax, and 1 to 60% by weight alcohol, or 1 to 60% by weight of a carboxylic acid, or 1 to 60% by weight of alcohol and carboxylic acid Includes.

[0043] The hydrocarbon wax may have a freezing point ranging from about 65°C to about 115°C.

[0044] Preferably, the hydrocarbon wax has a freezing point in the range of about 80°C to about 108°C.

[0045] The hydrocarbon wax may have a Brookfield viscosity at 135° C., measured according to ASTM D 3236, of less than 20 mPa·s.

[0046] The hydrocarbon wax may have a penetration of less than 10 1 / 10 mm at 25° C. as measured according to ASTM D 1321.

[0047] The hydrocarbon wax may have an oil content (oil content) measured according to ASTM D 721 of less than 1% by weight.

[0048] The hydrocarbon wax may be a hydrotreated or non-hydrotreated hydrocarbon wax.

[0049] The hydrocarbon wax may be a Fischer-Tropsch wax.

[0050] Thus, the hydrocarbon wax may be a hydrotreated Fischer-Tropsch wax or a non-hydrotreated Fischer-Tropsch wax.

[0051] In a preferred embodiment of the invention, the hydrocarbon wax is one or more of the Fischer-Tropsch waxes commercially available under the trade name SERATION from Sasol Chemicals, a division of Sasol South Africa Limited, 50 Katherine Street, Sandton, South Africa.

[0052] Fischer-Tropsch waxes are obtained by Fischer-Tropsch synthesis. In the context of the present invention, such waxes may be hydrocarbons derived from a cobalt or iron catalyzed Fischer-Tropsch synthesis of synthesis gas (mainly CO and H2) to alkanes. The crude product of this synthesis (syncrude) is typically fractionated, for example by distillation, into separate liquid and solid fractions. The hydrocarbons obtained from the Fischer-Tropsch synthesis contain mainly linear alkanes, a few branched alkanes and essentially no cycloalkanes or impurities, such as sulfur or nitrogen.

[0053] Fischer-Tropsch waxes are composed of methylene units and their carbon chain length distribution is characterized in one embodiment by an even increase or decrease in the number of molecules for a particular carbon atom chain length involved, which can be seen, for example, in a gas chromatography analysis of the Fischer-Tropsch wax.

[0054] The Fischer-Tropsch wax may have a content of branched hydrocarbons of 10-25 wt.%. The branched hydrocarbons of the Fischer-Tropsch wax may contain more than 10 wt.%, more preferably more than 25 wt.%, of hydrocarbons with methyl branches. The branched hydrocarbons of the Fischer-Tropsch wax may contain no quaternary carbon atoms. The absence of quaternary carbon atoms can be seen, for example, in an NMR measurement of the Fischer-Tropsch wax.

[0055] The alcohol may be a C9 to C32 alcohol. Preferably, the alcohol is a C16 to C32 alcohol.

[0056] The alcohol may be a straight chain alcohol, a branched alcohol, or a mixture thereof.

[0057] The linear alcohol may be a linear primary alcohol. The branched alcohol may be a branched primary alcohol.

[0058] The branched alcohol may be a Guerbet alcohol.

[0059] In one embodiment of the present invention, the alcohol is a mixture of predominantly C16 and C18 straight chain primary alcohols.

[0060] The carboxylic acid may be a C11 to C32 carboxylic acid, preferably a C18 to C22 carboxylic acid.

[0061] The carboxylic acid may be a straight chain carboxylic acid, a branched carboxylic acid, or a mixture thereof.

[0062] The carboxylic acid may be a saturated carboxylic acid, an unsaturated carboxylic acid, or a mixture thereof.

[0063] Preferably, the carboxylic acid is a C18 to C32 linear saturated carboxylic acid.

[0064] The resin may be a tackifier.

[0065] The tackifier may be selected from the group including aromatic, aliphatic and cycloaliphatic hydrocarbon resins, mixed aromatic and aliphatic modified hydrocarbon resins, aromatic modified aliphatic hydrocarbon resins, and hydrogenated versions thereof; terpenes, modified terpenes, and hydrogenated versions thereof; natural resins, modified resins, resin esters, and hydrogenated versions thereof; low molecular weight polylactic acids; and combinations thereof.

[0066] The processing oil (processing oil) may be selected from the group including mineral oil, naphthenic oil, paraffinic oil, aromatic oil, castor oil, rapeseed oil, triglyceride oil, or combinations thereof. As will be appreciated by those skilled in the art, the processing oil may also include extender oils commonly used in adhesives.

[0067] When the hot melt adhesive composition comprises a processing oil, the processing oil typically modifies the rheology of the hot melt adhesive, providing it with additional flexibility.

[0068] Processing oils are not suitable for all hot melt adhesive compositions because they tend to migrate to the surface and leave behind oily residues. Typically, they are not suitable when the application of an article or product comprising a laminate produced using the adhesive composition of the present invention may be adversely affected by the presence of oily residues thereon. This may be particularly relevant for applications where the adhesive composition may come into direct contact with, for example, food, medical devices, delicate packaging, or hygiene products. Migration of processing oils to the surface of such articles or products may adversely affect the quality and / or safety of the product. For example, in hygiene products, oily residues may cause undesirable skin irritation.

[0069] As used herein, the terms "hygiene product" and "hygiene application" refer to products or applications that relate to articles that are applied to, used on, or worn on the human body and thus used in contact with the human body for hygienic purposes, such as to collect or manage bodily fluids. For example, such articles may include, but are not limited to, diapers, adult incontinence devices, feminine hygiene articles, such as absorbent pads, wound dressings, bed pads, industrial pads, and sanitary napkins.

[0070] The hot melt adhesive composition described above may be suitable for use in the manufacture of laminates. By laminate is meant a layered structure that includes various combinations of materials, such as a single layer and a substrate or two or more layers, including but not limited to sheet materials including a nonwoven layer, a polyethylene polymer layer, and / or a polypropylene polymer layer, at least some of which are bonded together by means of an adhesive composition.

[0071] The hot melt adhesive compositions described above may be suitable for use in producing laminates for hygiene applications, packaging applications, mattress manufacture, and the like.

[0072] Preferably, the hot melt adhesive composition described above is suitable for use in the manufacture of laminates for sanitary applications.

[0073] The hot melt adhesive composition may have a shear tan delta (G" / G") equal to 1 in the range of 60°C to 100°C, preferably in the range of 65°C to 85°C, in dynamic mechanical analysis.

[0074] The hot melt adhesive composition may be sprayable at a temperature of up to 160°C, preferably at a temperature in the range of 100°C to 160°C, more preferably at a temperature in the range of 125°C to 145°C.

[0075] The selection of hydrocarbon waxes and alcohol and / or carboxylic acid containing polymers, resins, and additives according to the present invention provides excellent hot melt adhesives for use in producing laminates, having excellent low temperature sprayability, high peel strength, fast cure time, and excellent flexibility.

[0076] In one preferred embodiment of the present invention the hot melt adhesive composition comprises: 30-60% by weight of a propylene-ethylene based amorphous polyolefin polymer; 5-10% by weight of an additive comprising, more preferably consisting essentially of, a hydrocarbon wax and an alcohol; 30 to 60% by weight of resin, and 0-2% by weight of antioxidant; Here, the additive comprises 20-60% by weight of alcohol and 80-40% by weight of hydrocarbon wax.

[0077] The propylene-ethylene based amorphous polyolefin polymer may be, for example, the polymer sold under the trade name AERAFIN 35.

[0078] The resins, antioxidants, and hydrocarbon waxes can be as described above.

[0079] Preferably, the alcohol is a mixture of predominantly C16 and C18 primary linear alcohols, or the alcohol is a branched alcohol.

[0080] When the alcohol is a branched alcohol, preferably the branched alcohol is a Guerbet alcohol, more preferably a C32 Guerbet alcohol.

[0081] In another preferred embodiment of the present invention the hot melt adhesive composition comprises: 30-60% by weight of a propylene-based olefin polymer; 5-10% by weight of an additive comprising, more preferably consisting essentially of, a hydrocarbon wax and an alcohol; 30 to 60% by weight of resin, and 0-2% by weight of antioxidant; Here, the additive comprises 20-60% by weight of alcohol and 80-40% by weight of hydrocarbon wax.

[0082] The propylene-based olefin polymer may be, for example, the polymer sold under the trade name AERAFIN 17.

[0083] The resins, antioxidants, and hydrocarbon waxes can be as described above.

[0084] Preferably, the alcohol is a branched alcohol, or the alcohol is a mixture of predominantly C16 and C18 primary linear alcohols. When the alcohol is a branched alcohol, preferably the branched alcohol is a Guerbet alcohol, more preferably a C32 Guerbet alcohol.

[0085] In another preferred embodiment of the present invention the hot melt adhesive composition comprises: 30-60% by weight of an isotactic propylene-based polymer; 5-10% by weight of an additive comprising, more preferably consisting essentially of, a hydrocarbon wax and a carboxylic acid; 30 to 60% by weight of resin, and 0-2% by weight of antioxidant; Here, the additive contains 30 to 60% by weight of a carboxylic acid and 70 to 40% by weight of a hydrocarbon wax.

[0086] The isotactic propylene-based polymer may be, for example, a polymer commercially available under the trade name VISTAMAXX.

[0087] The resins, antioxidants, and hydrocarbon waxes can be as described above.

[0088] Preferably, the carboxylic acid is a C18 carboxylic acid.

[0089] In another preferred embodiment of the invention, the additive comprises 30-50% by weight of linear alcohol and / or linear carboxylic acid and 70-50% by weight of hydrocarbon wax, more preferably 40% by weight of linear alcohol and / or linear carboxylic acid and 60% by weight of hydrocarbon wax, based on the weight of the additive.

[0090] The polymers, resins, antioxidants, and hydrocarbon waxes may be as described above.

[0091] The linear alcohol and / or linear carboxylic acid may be further as described above.

[0092] In another preferred embodiment of the invention, the additive comprises 10-30% by weight of branched alcohol and / or branched carboxylic acid and 90-70% by weight of hydrocarbon wax, more preferably 20% by weight of branched alcohol and / or branched carboxylic acid and 80% by weight of hydrocarbon wax, based on the weight of the additive.

[0093] The polymers, resins, antioxidants, and hydrocarbon waxes may be as described above.

[0094] The branched alcohol and branched carboxylic acid may be further as described above.

[0095] According to another aspect of the present invention there is provided a hot melt adhesive composition comprising: 20-70% by weight of polymer; an additive consisting essentially of 1-15% by weight alcohol; 20 to 70 weight percent resin; and Optionally antioxidants and / or processing oils Includes.

[0096] The polymers, alcohols, resins, antioxidants, and processing oils may be as described above.

[0097] Method for producing hot melt adhesive composition According to another aspect of the invention, there is provided a method for producing a hot melt adhesive composition as defined above, comprising: mixing the polymer, the additives, the resin, and optionally the processing oil and / or the antioxidant, in a heated mixer until they are homogeneous, thereby producing a molten hot melt adhesive composition; and Pelletizing the molten hot melt adhesive composition, thereby producing hot melt adhesive pellets. Includes.

[0098] The polymers, additives, resins, processing oils, and antioxidants may be as described above.

[0099] Pelletization of the molten hot melt adhesive can be accomplished by any suitable means known in the art, such as strand pelletization, underwater pelletization, or spray pelletization.

[0100] Manufacturing method of laminate According to another aspect of the invention there is provided a method of producing a laminate comprising: providing a first layer and a second layer; coating the first layer and / or the second layer with the hot melt adhesive composition described above; positioning the first layer and the second layer such that the coating of the hot melt adhesive composition on the first layer and / or the second layer is disposed between the first layer and the second layer; and pressing the first layer and the second layer together, thereby producing a laminate. Includes.

[0101] As used herein, the term "layer" may be taken to mean a material having a thickness, for example a sheet of material.

[0102] The first layer may be a nonwoven layer or a polymer layer. The second layer may be a nonwoven layer or a polymer layer.

[0103] The polymer layer may be a polyethylene polymer layer, a polypropylene polymer layer, or a combination thereof.

[0104] When the first layer and / or the second layer are nonwoven layers, the laminate may be known as a nonwoven laminate.

[0105] The coating can be carried out by spray coating, die slot coating or other suitable application means. Preferably, the coating is applied by means of spray coating, more preferably by means of spiral spray coating, such that the coating of the hot-melt adhesive composition on the first layer and / or the second layer is in a spiral spray pattern.

[0106] The spray coating can be carried out at a temperature of 160°C or less, preferably at a temperature in the range of 100°C to 160°C, and more preferably at a temperature in the range of 125°C to 145°C.

[0107] Spray coating is 1-4g / m 2 with a coating weight of preferably 2 g / m 2 may be applied to the first layer and / or the second layer at a coating weight of

[0108] Spray coatings can be applied with nozzle air pressures of 0.005 to 0.05 MPa.

[0109] Pressing the first layer and the second layer together may include feeding the first layer and the second layer between two rollers, thus pressing the layers together. The rollers may be pneumatic rollers.

[0110] The method may further include winding the laminate into a roll for cooling and storage.

[0111] In a preferred embodiment of the method, the first layer is a nonwoven layer and the second layer is a polymer layer, resulting in a nonwoven laminate. Preferably, the polymer layer is a polyethylene polymer layer.

[0112] Laminate and its use According to another aspect of the present invention there is provided a laminate produced using and thus comprising the hot-melt adhesive composition as defined above, optionally produced according to the inventive method for producing a laminate.

[0113] The laminate may comprise at least one nonwoven layer. Preferably, the laminate comprises at least one nonwoven layer and one polymer layer, i.e., the laminate is a nonwoven laminate.

[0114] Preferably, the polymer layer is a polyethylene polymer layer.

[0115] The laminate may have a flexibility of up to 1400 N / m measured according to the flexibility method described below.

[0116] The laminate may be used in hygiene applications, packaging applications, and / or in mattress manufacture.

[0117] Thus, according to another aspect of the present invention there is provided the use of a laminate as described above in bonding two or more layers or materials together in hygiene applications, packaging applications and / or in mattress manufacture.

[0118] Preferably the laminate is used for sanitary applications.

[0119] Use of hot melt adhesives According to a further aspect of the invention there is provided the use of a hot melt adhesive composition as described above as an adhesive for lamination.

[0120] Measurement method The following methods were applied in the examples and, where applicable, to characterize the components of the compositions of the invention and the compositions of the invention.

[0121] All freezing points were measured according to ASTM D 938 and all ring and ball softening points of the polymers were measured according to ASTM E 28.

[0122] The Brookfield viscosity of the polymers at 190° C., the hot-melt adhesive compositions at 140° C. and 160° C., and the hydrocarbon waxes at 135° C. were measured according to ASTM D 3236 using a Brookfield DV-II+ Pro Extra viscometer with a #27 spindle using a Thermosel™.

[0123] Viscosity of hydrocarbon waxes below 15 mPa·s was measured according to ASTM D 445.

[0124] The penetration of hydrocarbon waxes (penetration) at 25° C. was measured according to ASTM D 1321, and the penetration of polymers was measured according to ASTM D5 or ASTM D 2240 (durometer hardness).

[0125] The glass transition temperature (Tg) of the polymer was measured according to ASTM D 3418.

[0126] The oil content of the hydrocarbon waxes was determined according to ASTM D 721.

[0127] The molar mass (number average) and isoalkane content of the hydrocarbon waxes were determined by gas chromatography according to the European Wax Federation EWF method 001 / 03.

[0128] The T-peel strength ("T-peel") of hot melt adhesive compositions was measured according to ASTM D 1876. The prepared samples were tested for their T-peel strength after 1 hour using an Instron 3366-B16875. The T-peel strength of each sample was determined by preparing five strips, each 25 mm x 250 mm. The sample strips were pulled apart at a rate of 300 mm / min using a 100 N load cell to obtain the T-peel results in g / inch.

[0129] flexibility method The flexibility of the samples was tested according to the flexibility method using an Instron 3366-B16875 as follows: Each sample was cast on a silicon mold to prepare a 10 mm x 50 mm sample with a thickness of 3 mm. The sample was compressed and returned 4 mm at a rate of 10 mm / min using a 10 kN load cell to determine the flexural modulus. Small thickness deviations on the adhesive samples were addressed by correcting the force value to match that of a 3 mm thick stave. The flexibility was evaluated using the flexural modulus force constant. Four specimens of each adhesive composition were tested and the average flexibility (N / m) was determined across all four specimens.

[0130] The area lost is the area between the flexural modulus curve when a load is applied and the flexural modulus curve after the load is removed. The smaller this area, the more the specimen tends to return to its original position after deformation. The larger this area, the less the specimen tends to return to its original position after deformation. This ability, known as the elasticity of the sample, is therefore a measure of the sample's ability to resist deformation. The % area lost is calculated as the difference in area between the two flexural modulus curves as a percentage of the larger area.

[0131] The interquartile range (IQR) was used to evaluate the sprayability of the hot melt adhesive composition. The sprayability factor was determined by IQR / T-peel. Throughout the experiments, it was found that a sprayability factor of less than 0.45 resulted in a consistent spray pattern when the T-peel was greater than 30.

[0132] The spray window is a measure of the robustness of an adhesive; it is essentially the temperature range over which the adhesive is sprayable with a minimum T-peel distribution and a minimum IQR / T-peel (sprayability factor).

[0133] For purposes of this specification, the following definitions apply: (i) the minimum spray temperature is the lowest temperature at which the hot melt adhesive composition is sprayable with a sprayability factor of 0.45 or less; (ii) the maximum spray temperature is the highest temperature at which the hot melt adhesive composition is sprayable with a sprayability factor of 0.45 or less; (iii) the spray window is the difference between the maximum spray temperature and the minimum spray temperature; (iv) The optimum spray temperature is the temperature at which the hot melt adhesive composition is sprayable with its minimum sprayability factor.

[0134] G´&G´´ were determined according to the DMA parallel plate method. Measurements were performed using a Paar MCR 502 rheometer (H-PTD 200 hood, P-PTD 200 lower plate). Samples were measured from 120°C to -30°C using a 25mm parallel plate measurement system with an amplitude strain of 0.015%, a frequency of 10Hz and a cooling rate of 2°C / min. The sample thickness was 2mm. The G´&G´´ crossover points were determined by plotting the G´&G´´ values ​​on the same axis (with the G´&G´´ trends overlaid) and measuring the points where the G´&G´´ trends cross each other. EXAMPLES

[0135] Working Example Publicly available physical property data for various commercially available polymers used in hot melt adhesive compositions (HMA) are shown in Tables 1a and 1b.

[0136] L-MODU S410 is a polypropylene homopolymer, Vistamaxx 8380 is composed mainly of isotactic propylene repeat units with random ethylene distribution, Koattro PB M 1500M is a random copolymer of 1-butene with high ethylene content, Solutack 6810 is an ethylene 1-octene copolymer, Aerafin 17 and Aerafin 35 are propylene-based olefin polymers, Rextac RT 2788 is an amorphous polyalphaolefin-based polymer based on a copolymer of butene-1 and propylene, and Infuse 9807 is an olefin block copolymer.

[0137] [Table 1]

[0138] [Table 2]

[0139] The hydrocarbon wax used in the HMA composition was a Fischer-Tropsch wax commercially available from Sasol under the trade name SERATION 1820. Physical property data for SERATION 1820 hydrocarbon wax are shown in Table 2.

[0140] [Table 3]

[0141] Commercially available polymers (Table 1) were formulated into various HMA compositions of the invention, including: (i) Polymer (ii) Tackifying resin as a tackifier (iii) a hydrocarbon wax and an additive containing either an alcohol or a carboxylic acid (iv) Antioxidants (v) Optionally, processing oil.

[0142] Similarly, commercially available polymers (Table 1) were formulated into various comparative HMA compositions, including: (i) Polymer (ii) Tackifying resin as a tackifier (iii) an additive containing either a hydrocarbon wax alone or an alcohol alone; and (iv) Antioxidants (v) Optionally, processing oil.

[0143] All HMA compositions were prepared using a shear mixing vessel at a temperature of 150°C.

[0144] The tackifying resin used in the HMA composition was Regalite R1090 available from Eastman.

[0145] The antioxidant used in the HMA composition was Irganox 1010, commercially available from BASF. Antioxidants were added to hot melt adhesive formulations to improve their stability at higher processing temperatures; because higher processing temperatures cause the degradation of some polymers and other components in the formulation, resulting in a decrease in adhesive performance over time. Thus, although antioxidants are not required when formulating functional hot melt adhesives, it is common practice to include antioxidants to mitigate high temperature denaturation.

[0146] The process oil used (process oil) was NYFLEX 3100, a hydrotreated, highly refined, high viscosity naphthenic oil commercially available from Nynas AB.

[0147] A variety of straight and branched chain alcohols and straight and branched chain carboxylic acids were used in the HMA compositions.

[0148] ISOCARB 12 is a C12 Guerbet acid (2-butyl-octanoic acid) commercially available from Sasol. ISOCARB 12 is derived from the corresponding C12 Guerbet alcohol ISOFOL 12 (2-butyl-1-octanol), also commercially available from Sasol.

[0149] Stearic acid is a C18 carboxylic acid with the IUPAC name octadecanoic acid.

[0150] Erucic acid is a C22 monounsaturated omega-9 carboxylic acid, also known as cis-13-docosenoic acid.

[0151] ISOCARB 24 is a C24 Guerbet acid (2-decyl-tetradecanoic acid) commercially available from Sasol. ISOCARB 24 is derived from the corresponding C24 Guerbet alcohol ISOFOL24.

[0152] NAFOL 1618H is a mixture of C16-C18 linear primary alcohols commercially available from Sasol.

[0153] ALFOL20+ is a blend of C20+ linear primary alcohols with even numbered carbon chain lengths, commercially available from Sasol.

[0154] ISOFOL 32 is C32 Guerbet alcohol (2-tetradecyl-1-octadecanol) commercially available from Sasol.

[0155] The HMA compositions for each polymer are shown in Tables 3a-3h.

[0156] [Table 4]

[0157] [Table 5]

[0158] [Table 6]

[0159] [Table 7]

[0160] [Table 8]

[0161] [Table 9]

[0162] [Table 10]

[0163] [Table 11]

[0164] result Each HMA composition was evaluated: (i) spray window, minimum spray temperature, and optimum spray temperature; (ii) T peel strength (1 h, 24 h, 2 weeks); (iii) flexibility (force constant), and (iv) G´&G´´ crossover point (intersection).

[0165] The evaluation results of each hot melt adhesive composition are shown in Table 4.

[0166] [Table 12-1] [Table 12-2]

[0167] Hydrocarbon waxes act as effective nucleating agents and therefore increase the crystalline fraction of the hot-melt adhesive composition. The increase in crystallinity occurs rapidly and is obtained within the first hour after coating. Although there is a build-up of strength observed in hot-melt adhesive compositions containing hydrocarbon waxes, as shown by the comparative examples, the stiffness associated with this increased strength is undesirable, especially in hygiene or personal care applications.

[0168] The additives comprising hydrocarbon waxes and alcohols and / or carboxylic acids in the hot-melt adhesive composition of the present invention act as crystallinity breakers leading to a less rigid and more flexible hot-melt adhesive composition without sacrificing adhesive strength and at the same time maintaining fast curing times, as shown in the examples of the present invention.

[0169] Overall, the results show that the hot melt adhesive composition of the present invention is a robust composition. In particular, the results demonstrate that the hot melt adhesive composition of the present invention exhibits one or more of the following compared to the comparative composition: an increased spray window, a lower optimum spray temperature, a faster cure time, and significantly improved flexibility. The T-peel strength is high and stable over time, with the optimum adhesive strength being obtained within 1 hour.

[0170] The hot melt adhesive compositions according to the invention therefore offer great formulation flexibility and are well suited for use in applications such as hygiene and personal care, but also in applications such as packaging and mattress manufacture.

Claims

1. A hot melt adhesive composition comprising, based on the total weight of the hot melt adhesive composition: 20 to 70 wt. % of a polymer; 1 to 15 wt. % of an additive comprising a hydrocarbon wax and, in addition to the hydrocarbon wax, an alcohol and / or a carboxylic acid; 20 to 70% by weight of a resin, and optionally antioxidants and / or processing oils, Including, The alcohol is a C9 to C32 alcohol and the carboxylic acid is a C11 to C32 carboxylic acid. Hot melt adhesive composition.

2. 2. The hot melt adhesive composition according to claim 1, wherein the hot melt adhesive composition comprises 30 to 60 wt. % of the polymer, based on the total weight of the hot melt adhesive composition.

3. 2. The hot melt adhesive composition of claim 1, wherein the hot melt adhesive comprises 3 to 15 wt. % of the additive, based on the total weight of the hot melt adhesive composition.

4. 2. The hot melt adhesive composition according to claim 1, wherein the hot melt adhesive composition comprises 25 to 67 wt. % of the resin, based on the total weight of the hot melt adhesive composition.

5. 2. The hot-melt adhesive composition according to claim 1, wherein the hot-melt adhesive composition comprises 0 to 5 wt. % of said antioxidant, preferably 0.1 to 2 wt. % of said antioxidant, based on the total weight of the hot-melt adhesive composition.

6. 2. The hot melt adhesive composition according to claim 1, wherein said hot melt adhesive composition comprises 0 to 15 wt. % of processing oil, preferably 5 to 15 wt. % of processing oil, based on the total weight of the hot melt adhesive composition.

7. 2. The hot melt adhesive composition of claim 1, wherein the polymer is a polyolefin polymer.

8. The hot melt adhesive composition of claim 7, wherein the polyolefin polymer is an amorphous poly-alpha-olefin (APAO) copolymer, an olefin homopolymer, or an olefin block copolymer.

9. The hot melt adhesive composition according to claim 8, wherein the olefin block copolymer is an ethylene-propylene copolymer or an ethylene-butene copolymer.

10. The polyolefin polymer has the following properties: a Brookfield viscosity at 190°C, measured according to ASTM D 3236, of 1500 to 20000 mPa·s, preferably 1500 to 7570 mPa·s; A ring and ball softening point of 90°C to 130°C, measured in accordance with ASTM E 28; and 0.8~0.9g / cm ３ density of; 8. The hot melt adhesive composition according to claim 7, wherein the hot melt adhesive composition comprises one or more of:

11. said additive comprising 99 to 30 weight percent of said hydrocarbon wax, based on the weight of said additive; and 1 to 70% by weight of said alcohol, or 1 to 70% by weight of said carboxylic acid, or 1 to 70% by weight of the combination of the alcohol and the carboxylic acid; 2. The hot melt adhesive composition of claim 1, comprising:

12. 2. The hot melt adhesive composition according to claim 1, wherein said hydrocarbon wax has a freezing point in the range of 65°C to 115°C, preferably in the range of 80°C to 108°C.

13. The hydrocarbon wax has the following characteristics: a Brookfield viscosity at 135°C, measured in accordance with ASTM D 3236, of less than 20 mPa·s; a penetration at 25°C of less than 10 1 / 10 mm as measured in accordance with ASTM D 1321; and an oil content of less than 1 wt. %, as measured in accordance with ASTM D 721; 2. The hot melt adhesive composition of claim 1, wherein the hot melt adhesive composition comprises one or more of the following:

14. 2. The hot melt adhesive composition of claim 1, wherein the hydrocarbon wax is a Fischer-Tropsch wax.

15. 2. The hot melt adhesive composition according to claim 1, wherein said alcohol is a C16 to C32 alcohol and said carboxylic acid is a C18 to C22 carboxylic acid.

16. 2. The hot melt adhesive composition according to claim 1, wherein the shear tan delta (G" / G') in the dynamic mechanical analysis is equal to 1 in the range of 60°C to 100°C, preferably in the range of 65°C to 85°C.

17. 2. The hot-melt adhesive composition according to claim 1, wherein the hot-melt adhesive composition is sprayable at a temperature of up to 160°C, preferably at a temperature in the range of 100°C to 160°C, more preferably at a temperature in the range of 125°C to 145°C.

18. 2. A method for producing the hot melt adhesive composition of claim 1, comprising: mixing the polymer, the additives, the resin, and optionally the processing oil and / or the antioxidant with one another in a heated mixer in a molten state until they are homogeneous, thereby producing a molten hot-melt adhesive composition; pelletizing said molten hot melt adhesive composition, thereby producing hot melt adhesive pellets; A manufacturing method comprising:

19. 1. A method for manufacturing a laminate, comprising: providing a first layer and a second layer; coating the first layer and / or the second layer with the hot melt adhesive composition of claim 1; disposing the first layer and the second layer such that the hot melt adhesive composition coated on the first layer and / or the second layer is located between the first layer and the second layer; pressing the first layer and the second layer together, thereby producing a laminate; A method comprising:

20. 20. The method of claim 19, wherein the first layer is a nonwoven layer or a polymer layer, the second layer is a nonwoven layer or a polymer layer, and when the first layer and / or the second layer is a polymer layer, the polymer layer is a polyethylene polymer layer, a polypropylene polymer layer, or a combination thereof.

21. 20. The method according to claim 19, wherein said coating is carried out by means of spray coating, more preferably by means of spiral coating, such that the coating of said hot-melt adhesive composition on said first layer and / or said second layer is in a spiral spray pattern.

22. 22. The method of claim 21, wherein the spray coating is carried out at a temperature of up to 160°C, preferably at a temperature in the range of 100°C to 160°C, more preferably at a temperature in the range of 125°C to 145°C.

23. The spray coating is 1 to 4 g / m ２ with a coating weight of preferably 2 g / m ２ 22. The method of claim 21, wherein the first layer and / or the second layer is applied with a coating weight of

24. 22. The method of claim 21, wherein the spray coating is applied with a nozzle air pressure of 0.005 to 0.05 MPa.

25. 20. The method of claim 19, wherein pressing the first layer and the second layer together comprises feeding the first layer and the second layer between two rollers, thereby pressing the layers together.

26. 10. A laminate produced using and therefore comprising the hot melt adhesive composition of claim 1.

27. 27. The laminate of claim 26, wherein said laminate comprises at least one nonwoven layer, preferably at least one nonwoven layer and one polymer layer, said polymer layer being a polyethylene polymer layer.

28. 27. Use of the laminate according to claim 26 in hygiene applications, packaging applications and / or in mattress manufacturing.

29. 10. Use of the hot melt adhesive composition according to claim 1 as an adhesive for laminates.