Hot melt adhesive

Abstract

The present invention relates to a hot melt adhesive composition comprising a) a styrene block polymer component; b) at least one tackifying resin; and c) a bio-based plasticizer having a weight-average molecular weight of 2000 g / mol or more, wherein the hot melt adhesive composition contains 8.0% or more styrene, and the total weight content of the bio-based plasticizer c) is 12% by weight or less based on the weight of the hot melt adhesive composition.

Description

[Technical Field]

[0001] The present invention relates to a hot-melt adhesive that is particularly useful for disposable articles, and more specifically, for use as an adhesive for fixing elastic members. [Background technology]

[0002] Hot melt adhesives (HM adhesives) are solids at room temperature and contain neither water nor solvents. They are typically applied in a molten state after heating to a temperature of 120°C to 250°C, most commonly 130°C to 180°C, and solidify during cooling, thereby forming a seal (or adhesive bond) that ensures the attachment of two substrates to be assembled. Hot melt adhesives are generally provided in the form of compositions containing thermoplastic polymers, and optionally tackifiers and plasticizers. Among these HM adhesives, hot melt pressure-sensitive adhesives (HMPSAs) are substances that impart immediate tack properties (also called "tack") to substrates coated with the adhesive, enabling instantaneous adhesion of one substrate to another under slight, short-duration pressure at room temperature.

[0003] Disposable sanitary products are made from a wide variety of substrates (nonwoven fabrics, elastomers, polyolefin films, and especially films such as polyethylene or polypropylene films) bonded together with adhesive materials. Examples of disposable sanitary products include diapers, sanitary napkins, or adult incontinence disposable products. Disposable sanitary products are produced at high line speeds. In such production, hot-melt adhesives are typically used because they can be easily applied to the substrate (in a molten state) without any additional manufacturing steps such as solvent removal, and when cooled, they quickly produce a strong bond.

[0004] As described below, several types of hot-melt adhesives can be found in disposable sanitary items, depending on their intended use and final function.

[0005] • Core adhesive: Used not only during diaper manufacturing but also during diaper use, primarily after the diaper gets wet, to hold the diaper core (fluff and Super Absorbent Polymer (SAP)) in place.

[0006] • Construction adhesive: Bonds a polyethylene backsheet to a nonwoven fabric substrate, or bonds two nonwoven fabric substrates together.

[0007] • Elastic adhesives: Used to bond elastic materials (e.g., polyurethane strands) to sheet-like substrates (e.g., polyethylene "PE" or polypropylene "PP" and nonwoven fabric substrates).

[0008] In particular, in applications involving the fixation of elastic members, adhesives should maintain the elastic material in place, especially when subjected to stress during the manufacture and use of disposable sanitary items. In practice, during the manufacturing process, the elastic material (e.g., a set of elastic strands) is typically first stretched before joining, then the adhesive is applied to the elastic material by either non-contact (spray) or contact application, and the adhesive-coated elastic material is then quickly laminated between two sheet-like substrates (e.g., a nonwoven fabric substrate and a polyolefin film). The elastic material is then relaxed to create a gathered (or rushed) laminate with substantial flexibility. Therefore, the adhesive needs to exhibit high cohesiveness and elasticity to adequately withstand creep strength. Furthermore, good adhesion to the elastic material is also desirable to avoid any adhesion failures.

[0009] Furthermore, conventional hot-melt adhesives are petrochemical-based and rely on energy-intensive processes. In addition, much of the petroleum is transported from various parts of the world, which increases the carbon footprint. Generally, the raw materials in hot-melt adhesives are not made from renewable resources, or only a small amount is, so their contribution to the environment is insufficient. There is a growing demand to reduce the carbon footprint and produce environmentally friendly products. One way to create environmentally friendly adhesives is to reduce the carbon footprint by forming hot-melt adhesives from materials with a high renewable resource content. Moreover, adhesives made from renewable materials do not necessarily achieve the same or better properties as conventional petroleum-based adhesives. [Overview of the project] [Problems that the invention aims to solve]

[0010] Therefore, there is a need to provide an environmentally friendly hot-melt adhesive that can solve at least some of the aforementioned drawbacks.

[0011] There is a need to provide an environmentally friendly hot-melt adhesive composition that exhibits good adhesion properties on various substrate materials and fabrics, as well as low creep retention.

[0012] There is a need to provide an environmentally friendly hot-melt adhesive composition that strikes a good balance between low creep retention, good adhesive properties, and good cohesive strength.

[0013] There is a need to provide an environmentally friendly hot-melt adhesive composition that strikes a good balance between low creep retention, good adhesive properties, good cohesive strength, and high storage modulus and Young's modulus. [Means for solving the problem]

[0014] The present invention relates to a hot melt adhesive composition, -a) a styrene block polymer component; -b) at least one tackifier resin; -c) containing a bio-based plasticizer having a weight average molecular weight of 2000 g / mol or more, the hot melt adhesive composition contains a styrene content of 8.0% or more, and the total weight content of the bio-based plasticizer c) is 12% by weight or less based on the weight of the hot melt adhesive composition, relating to a hot melt adhesive composition.

[0015] In one embodiment, the styrene block polymer component includes a styrene block copolymer selected from the group consisting of SB, SI, SEB, SEP, SBBS, SBS, SEBS, SEPS, SEEPS, SIBS, SIS, random block SBR, random block SIR, and mixtures thereof.

[0016] Preferably, the styrene block polymer component includes an SIS or SBS copolymer.

[0017] Preferably, the hot melt adhesive composition contains 5% to 35% by weight, preferably 10% to 30% by weight, and more preferably 10% to 30% by weight of the styrene block polymer component based on the total weight of the hot melt adhesive composition.

[0018] In one embodiment, at least one tackifier resin is -i) natural and modified rosins such as, for example, gum rosin, wood rosin, tall oil rosin, distilled rosin, dimerized rosin and polymerized rosin, and hydrogenated derivatives thereof; -ii) glycol, glycerol and pentaerythritol esters of natural and modified rosins, and hydrogenated derivatives thereof, -iii) polyterpene homopolymers and hydrogenated derivatives thereof; -iv) copolymers of terpenes and diene monomers, and hydrogenated derivatives thereof; -v) phenol-modified terpene resins; - and is selected from the group consisting of these mixtures.

[0019] Preferably, the hot melt adhesive composition comprises a mixture of at least one tackifier resin ii) and at least one tackifier resin iii).

[0020] In one embodiment, the hot melt adhesive composition comprises 50 wt% to 90 wt%, preferably 55 wt% to 80 wt%, more preferably 55 wt% to 70 wt% of a tackifier resin (or a mixture of tackifier resins if more than one tackifier resin is present in the hot melt adhesive composition), based on the total weight of the hot melt adhesive composition.

[0021] Preferably, the styrene content of the hot melt adhesive composition is in the range of 8.0% to 15.0%, more preferably 9.0% to 12.0%.

[0022] Preferably, the bio-based plasticizer has a weight average molecular weight in the range of 3000 g / mol to 12000 g / mol, more preferably 3000 g / mol to 6000 g / mol.

[0023] In one embodiment, the bio-based plasticizer is selected from animal fats, vegetable oils (e.g., canola oil, corn oil, soybean oil, epoxidized soybean oil, palm oil, peanut oil, olive oil, sunflower oil, rapeseed oil, jatropha oil, coconut oil, castor oil, etc.), lactic acid derivatives, modified versions thereof, fatty acid derivatives, and combinations thereof.

[0024] Preferably, the bio-based plasticizer has an acid value in the range of 1 to 20, preferably 3 to 20 mgKOH / g.

[0025] Preferably, the bio-based plasticizer has a viscosity at 25°C in the range of 10, pas to 5000 mPas, preferably 1500 to 2500 mPas.

[0026] Preferably, the bio-based plasticizer is a fatty acid derivative, preferably a fatty acid ester, more preferably a fatty acid polyester, and even more preferably a homopolymer of ricinoleic acid.

[0027] In one embodiment, the hot melt adhesive composition contains 1% to 10% by weight, preferably 2% to 10% by weight, of a bio-based plasticizer c) based on the total weight of the hot melt adhesive composition.

[0028] In one embodiment, the hot melt adhesive comprises at least one fatty acid derivative d) having a weight-average molecular weight of 1500 g / mol or less, preferably 1000 g / mol or less, and more preferably in the range of 250 g / mol to 1000 g / mol.

[0029] Preferably, the hot melt adhesive composition has a Brookfield viscosity at 163°C of about 2000 to about 10000 mPa.s, preferably about 3000 to about 9000 mPa.s.

[0030] Preferably, the biocarbon content of the hot melt adhesive is 60% or more, preferably 65% ​​or more, and more preferably 70% or more.

[0031] Preferably, a hot melt adhesive composition, • Creep retention of 20% or less, more preferably 15% or less, and even more preferably 10% or less; and / or • Young's modulus of 2 MPa or more, more preferably 4 MPa or more; and / or • Storage modulus (G') at 25°C, of ​​100 kPa or higher, more preferably 500 kPa or higher. This indicates.

[0032] The present invention also relates to the use of the hot-melt adhesive composition of the present invention as a positioning adhesive, a core adhesive, or an adhesive for fixing elastic members, more preferably as an adhesive for fixing elastic members.

[0033] The present invention also relates to a laminate comprising at least one elastic material and at least two substrates, wherein the elastic material is inserted between the two substrates and covered with the hot-melt adhesive composition of the present invention.

[0034] The present invention also relates to an article comprising the laminate, wherein the article is preferably a disposable absorbent article. [Modes for carrying out the invention]

[0035] Herein, the present invention will be described in more detail without limitation.

[0036] Unless otherwise stated, percentages in this application refer to percentages by weight.

[0037] In this document, the quantities given for a given species can be applied to that species according to all of its definitions, including narrower definitions (as stated in this document).

[0038] <Hot melt adhesive composition> In a first embodiment, the present invention relates to a hot-melt adhesive composition. The term “hot-melt” is used herein to describe an adhesive composition that needs to be heated to at least 120°C, preferably at at least 140°C, in order to be applied to a substrate. Thus, the hot-melt adhesive composition is solid at 23°C.

[0039] The present invention relates to a hot melt adhesive composition, -a) Styrene block polymer components; -b) at least one tackifying resin; -c) Bio-based plasticizers having a weight-average molecular weight of 2000 g / mol or more Includes, The hot melt adhesive composition contains a styrene content of 8.0% or more, and The present invention relates to a hot melt adhesive composition in which the total weight content of bio-based plasticizer c) is 12% by weight or less, based on the weight of the hot melt adhesive composition.

[0040] A "bio-based plasticizer" refers to a plasticizer that is at least partially derived from biomaterials.

[0041] The bio-based plasticizer preferably has a biocarbon content of 85% or more, more preferably 90% or more, and more preferably 93% or more.

[0042] The term "biocarbon" indicates that the carbon is of renewable or natural origin and originates from biological materials, as shown below. Biocarbon content and biological material content are expressions that represent the same value.

[0043] Renewable materials, also known as biomaterials, are organic materials derived from carbon that has recently been fixed (on a human scale) from the atmosphere through photosynthesis, specifically CO2. On land, this CO2 is captured or fixed by plants. In the ocean, CO2 is captured or fixed by photosynthetic bacteria or plankton. Biomaterials (100% naturally occurring carbon) are 10 -12 Larger, typically about 1.2 × 10⁻⁶ -12 of 14 C / 12 While C has an isotopic ratio, fossil materials have a ratio of zero. In fact, isotopes 14 C is formed in the atmosphere and then integrated through photosynthesis over a timescale of at most a few decades. 14 The half-life of C is 5730 years. Therefore, the materials produced from photosynthesis, i.e., plants in general, must necessarily be the largest 14 It has a C isotope content.

[0044] The biobased content or biocarbon content is determined by using the standards ASTM D 6866 (ASTM D 6866-06) and ASTM D 7026 (ASTM D 7026-04). The ASTM D 6866 standard is "Determining the Biobased Content of Natural Range Materials Using Radiocarbon and Isotope Ratio Mass Spectrometry Analysis", while the ASTM D 7026 standard is "Sampling and Reporting of Results for Determination of Biobased Content of Materials via Carbon Isotope Analysis". The second standard references the first standard in its first paragraph.

[0045] The first standard describes tests for measuring the [[ID=⑤]] 14 [[ID=⑥]]C / [[ID=⑦]] 12 [[ID=⑧]]C ratio of the sample and gives the relative percentage of C of renewable origin in the sample by comparing the [[ID=⑨]] 14 [[ID=⑩]]C / [[ID=⑪]] 12 [[ID=⑫]]C ratio of the sample to the [[ID=⑬]] 14 [[ID=⑭]]C / [[ID=⑮]] 12 [[ID=⑯]]C ratio of a reference sample of 100% renewable origin. This standard is based on the same concept as radiocarbon dating but does not apply the dating equation. [[ID=⑰]] 14 [[ID=⑱]] 14 [[ID=⑲]] [[ID=⑳]]

[0046] [[ID=㉑]] [[ID=㉒]]The ratio calculated in this way is called "pMC" (percent Modern Carbon). If the material being analyzed is a mixture of biobased material and fossil material (containing no radioisotopes), the pMC value obtained is directly correlated with the amount of biobased material present in the sample. [[ID=㉓]] 14The baseline value used for 14C dating is the value from the 1950s. This year was chosen due to the presence of atmospheric nuclear tests that introduced large amounts of isotopes into the atmosphere after this date. The 1950 baseline corresponds to a pMC value of 100. Taking thermonuclear tests into account, the current value to be retained is approximately 107.5 (corresponding to a correction factor of 0.93). Therefore, the current radiocarbon signature of plants is 107.5. Thus, the signatures of 54 pMC and 99 pMC correspond to the amounts of biocarbon in 50% and 93% of the sample, respectively.

[0047] If the styrene block polymer component contains only one styrene block copolymer, the styrene content of the hot melt adhesive composition is defined as the styrene content of the styrene block polymer component multiplied by the weight of the styrene block polymer component in the hot melt adhesive composition.

[0048] If the styrene block polymer component contains a mixture of styrene block copolymers, the styrene content of the hot melt adhesive composition is defined as the sum of the styrene content of each styrene block copolymer present in the styrene block polymer component, multiplied by the weight of each styrene block copolymer present in the styrene block polymer component in the total hot melt adhesive composition.

[0049] For example, if polymer X' is present at 25% by weight (wX') and has a styrene content of 15% (sX'), and polymer Y' is present at 25% by weight (wY') and has a styrene content of 20% by weight (sY'), the average styrene content of this formulation is calculated as follows: wX'*sX'+wY'*sY'=0.25*15+0.25*20=8.75% by weight.

[0050] Preferably, the styrene content of the hot melt adhesive composition is in the range of 8.0% to 15.0%, more preferably 9.0% to 12.0%.

[0051] <Styrene block polymer component a)> The hot-melt adhesive composition of the present invention comprises a) a styrene block polymer component. "Styrene block polymer component" means a component comprising a copolymer that includes at least one SBC (styrene block copolymer), i.e., at least one styrene block including styrene triblock copolymer and styrene diblock copolymer.

[0052] A styrene block copolymer comprises at least one A block containing styrene and at least one B block containing, for example, elastomer-conjugated dienes (e.g., hydrogenated and unhydrogenated conjugated dienes), sesquiterpenes (e.g., hydrogenated and unhydrogenated sesquiterpenes), and combinations thereof. The A and B blocks are bonded to each other in any bonding mode such that the resulting copolymer exhibits a variety of structures, including, for example, random, linear, branched, radial, star-shaped, comb-shaped, tapered shapes, and combinations thereof. The block copolymer can also exhibit any form, including, for example, linear AB blocks, linear ABA blocks, linear A-(BA)nB multiblocks, and radial (AB)nY blocks, where Y is a polyvalent compound and n is an integer of at least 3, tetrablock copolymers, for example, ABAB, and pentablock copolymers having the structure ABABA.

[0053] Suitable styrene A blocks include, for example, styrene, alpha-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 2,4-dimethylstyrene, 2,4,6-trimethylstyrene, and combinations thereof.

[0054] Suitable block elastomer conjugated diene B blocks include, for example, butadiene (e.g., polybutadiene), isoprene (e.g., polyisoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene and combinations thereof, as well as their hydrogenated versions, including, for example, ethylene, propylene, butylene and combinations thereof.

[0055] A suitable B-block sesquiterpene is, for example, beta-farnesene.

[0056] The styrene block polymer component may include one or a mixture of styrene block copolymers.

[0057] If more than one styrene block copolymer is present, the styrene content, diblock content, and melt flow rate range specified for the styrene block polymer component are the weight average of all grades present. For example, suppose a styrene block polymer component contains two styrene block copolymers, X and Y. Polymer X is present at 25 wt% (wX) and has a styrene content of 15% (sX), and polymer Y is present at 25 wt% (wY) and has a styrene content of 20 wt% (sY). The average styrene content of the styrene block polymer component is calculated as follows: wX / (wX+wY)*sX+wY / (wX+wY)*sY=0.5(15)+0.5(20)=17.5 wt%.

[0058] The styrene block polymer component preferably has an average styrene content of 20% to 50% by weight, more preferably 30% to 50% by weight, and even more preferably 30% to 47%.

[0059] The styrene block polymer component preferably contains 0% to 40% by weight, more preferably 0% to 30% by weight, and even more preferably 0% to 15% by weight of diblocks.

[0060] "Diblock content" refers to the weight percentage of diblock copolymer in the styrene block polymer component.

[0061] The styrene block polymer component preferably includes a styrene block copolymer selected from the group consisting of SB, SI, SEB, SEP, SBBS, SBS, SEBS, SEPS, SEEPS, SIBS, SIS, random block SBR, random block SIR, and mixtures thereof.

[0062] Preferably, the styrene block copolymer is SIS or SBS copolymer.

[0063] "SBBS" stands for styrene-butadiene-butylene-styrene triblock copolymer. "SBS" stands for styrene-butadiene-styrene triblock copolymer. "SEBS" stands for styrene-ethylene-butylene-styrene triblock copolymer. "SEPS" stands for styrene-ethylene-propylene-styrene triblock copolymer. "SEEPS" stands for styrene-ethylene-ethylene-propylene-styrene triblock copolymer. "SIBS" stands for styrene-isoprene-butadiene-styrene triblock copolymer. "SIS" stands for styrene-isoprene-styrene triblock copolymer. "Random block SBR" stands for random block styrene-butadiene copolymer (where some of the styrene exists as polystyrene blocks). "Random block SIR" stands for random block isoprene-butadiene copolymer (where some of the styrene exists as polystyrene blocks). "SB" stands for styrene-butadiene diblock copolymer. "SI" stands for styrene-isoprene diblock copolymer. "SEB" stands for styrene-ethylene-butylene diblock copolymer. "SEP" stands for styrene-ethylene-propylene diblock copolymer.

[0064] Useful commercially available styrene block copolymers include the KRATON D and G(R) series from Kraton Polymers, the EUROPRENE Sol T(R) series from Versalis (Eni group), the SOLPRENE(R) series from Dynasol Elastomers, the SINOPEC(R) series from SINOPEC, and the Taipol(R) and Vector(R) series from TSRC Corporation. Other useful examples include the following: Sinopec(R) YH-1126, a linear SIS triblock copolymer having a 16% styrene content and a 50% diblock content; Sinopec(R) YH-1209, a linear SIS triblock copolymer having a styrene content of 30% and a diblock content of less than 1%; Kraton(R) D1152 is a mixture of linear SBS triblock and SB diblock copolymers, having a styrene content of 29.5% by weight relative to the total weight of the mixture, an average molecular weight of approximately 122,000 g / mol, a melt flow index or MFI of 8.5 g / 10 min at 200°C under a load of 5 kg (measured according to ISO 1133), and an SB diblock content of approximately 17% by weight relative to the total weight of the mixture. Kraton(R) D1161 is a mixture of linear SIS triblock and SI diblock copolymers, with a styrene content of 15% by weight relative to the total weight of the mixture, an MFI of 9 g / 10 min at 200°C under a 5 kg load (measured according to ISO 1133), an average molecular weight of approximately 220,000 g / mol, and an SI diblock content of approximately 19% by weight relative to the total weight of the mixture. Taipol(R) SBS 4202 from TSRC Corporation, a linear SBS triblock copolymer with an average molecular weight of approximately 102,400 g / mol, measured at 190°C under a 5 kg load, with a styrene content of 40% by weight relative to the total weight of the triblock copolymer, and an MFI (measured according to ASTM D1238) of 3-10 g / 10 min. Vector(R)4411 from TSRC Corporation, a linear SIS triblock copolymer with a styrene content of 44% by weight relative to the total weight of the triblock copolymer, and an average molecular weight of approximately 106,000 g / mol, measured at 200°C at a load of 5 kg using MFI (measured according to ASTM D1238) at 40 g / 10 min. Europrene(R)SOL TE9326 (linear SIS triblock copolymer, approximately 30% styrene block content, approximately 15% diblock content, from Versalis).

[0065] Preferably, the hot-melt adhesive composition is substantially free of radial styrene block copolymer.

[0066] The hot melt adhesive composition preferably contains 5% to 35% by weight of styrene block polymer components, based on the total weight of the hot melt adhesive composition. More preferably, the hot melt adhesive composition contains 10% to 30% by weight, and even more preferably 15% to 30% by weight of styrene block polymer components, based on the total weight of the hot melt adhesive composition.

[0067] <Tackifying resin b)> The hot melt adhesive composition includes b) at least one tackifying resin (tackifier).

[0068] A suitable tackifying resin for the present invention is one that is compatible with styrene block polymer components.

[0069] The adhesive resin is Aliphatic petroleum hydrocarbon resins obtained from the polymerization of monomers mainly consisting of olefins and diolefins, and their hydrogenated derivatives; • Cyclic petroleum hydrocarbon resins and their hydrogenated derivatives; Aromatic petroleum hydrocarbon resins and their hydrogenated derivatives; Aromatically modified alicyclic resins and their hydrogenated derivatives; Aromatically modified aliphatic resins and their hydrogenated derivatives; • Terpene resins and their hydrogenated derivatives; • Rosin resins and their hydrogenated derivatives; These mixtures A selection can be made from the group consisting of the following:

[0070] Examples of suitable tackifying resins include Eastotac(R) H100W (C5 fully hydrogenated resin) from Eastman Chemical Company; Escorez(R) 2203LC (C5 / C9 resin) from ExxonMobil Chemical; Sukorez(R) SU 120 (DCPD fully hydrogenated resin), Sukorez(R) SU 210 (DCPD / C5 fully hydrogenated resin), Sukorez(R) SU 420 (DCPD / C9 partially hydrogenated resin), Sukorez(R) SU 525 (DCPD fully hydrogenated resin) and Hikorez(R) H2100 (C5 hydrogenated resin) from Kolon; Regalite(R) S7125 (C9 partially hydrogenated resin) from Eastman Chemical Company; HS-130 (DCPD hydrogenated resin) from Hanwha Solutions / chemical Corporation; and Luhorez from Tianjin Luhua Chemical. HD1120 (Hydrogenated DCPD Resin); Henghe Materials and Science Technology Co.Products marketed by LTD under the trade names Henghe HM1000 (resin DCPD / C9 hydrogenated) and Henghe H5-1001 (resin C5 fully hydrogenated); unmodified natural tall oil rosin from Kraton sold under the trade name Sylvaros(R) (85, 90 and NCY); partially hydrogenated rosin from Eastman sold under the trade name Foralyn(R)E; fully hydrogenated rosin from Eastman sold under the trade name Foral(R)AX-E; fully hydrogenated rosin from DRT sold under the trade name Foral(R)DX; fully hydrogenated rosin ester from DRT sold under the trade name Foral(R)105; dimerized rosin from Eastman sold under the trade name Dymerex(R); Sylvalite(R)RE 100L or RE 100S (pentaerythritol-based tall oil rosin ester) from Kraton, Sylvalite(R)RE Examples include 85L (glycerol ester of tall oil rosin); Sylvalite 9000 (fully hydrogenated tall oil rosin ester) from Kraton; polyterpene tackifiers from Kraton sold under the trade names Sylvagum(R)TR and Sylvares(R)TR series (7115, 7125, A25L, B115, M1115); polyterpene PX1250H from Yasuhara; polyterpenes from DRT sold under the trade name DERCOLYTE(R)M105 (obtained from polymerization of α-pinene and β-pinene, with a ring softening point of 105°C); and terpene phenol resins from Kraton sold under the trade names Sylvares(R)TP (96, 2040, 300, 7042, 2019).

[0071] Examples of terpene resins include polyterpene homopolymers, copolymers of terpenes and diene monomers (e.g., styrene, α-methylstyrene, etc.), and phenol-modified terpene resins.

[0072] The term "copolymer" typically includes terpolymers.

[0073] Hydrogenated derivatives typically include both partially and fully hydrogenated derivatives.

[0074] Rosin-based resins include rosin and rosin esters.

[0075] The tackifying resin may have a ring softening point (measured according to ASTM E28) of approximately 50°C to 140°C, such as approximately 50 to 90°C, approximately 90 to 120°C, or approximately 120 to 140°C.

[0076] Preferably, at least one tackifying resin is -i) Natural and modified rosins, such as gum rosin, wood rosin, tall oil rosin, distilled rosin, dimerized rosin and polymerized rosin, as well as their hydrogenated derivatives; -ii) For example, natural and modified rosin glycols, glycerol and pentaerythritol esters, and their hydrogenated derivatives, such as pale wood rosin glycerol esters, hydrogenated rosin glycerol esters, polymerized rosin glycerol esters, pale wood rosin pentaerythritol esters, hydrogenated rosin pentaerythritol esters, tall oil rosin pentaerythritol esters, tall oil rosin esters obtained from a mixture of glycerol and pentaerythritol, pale wood rosin esters obtained from a mixture of glycerol and pentaerythritol, hydrogenated rosin esters obtained from a mixture of glycerol and pentaerythritol, polymerized rosin esters obtained from a mixture of glycerol and pentaerythritol, and phenol-modified pentaerythritol esters of rosin; -iii) Polyterpene homopolymers and their hydrogenated derivatives; -iv) Copolymers of terpenes and diene monomers, and their hydrogenated derivatives; -v) For example, phenol-modified terpene resins, such as those resulting from the condensation of terpenes and phenols in an acidic medium; - and mixtures thereof It is selected from the group consisting of the following.

[0077] More specifically, the hot melt adhesive composition comprises a mixture of at least one tackifying resin ii) and at least one tackifying resin iii) as defined above.

[0078] The tackifying resin may have a biocarbon content of 70% or more, preferably 80% or more, and more preferably 90% or more.

[0079] The hot melt adhesive composition preferably contains 50% to 90% by weight, more preferably 55% to 80% by weight, and even more preferably 55% to 70% by weight of tackifying resin (or a mixture of tackifying resins if multiple tackifying resins are present in the hot melt adhesive composition), based on the total weight of the hot melt adhesive composition.

[0080] Preferably, the hot melt adhesive composition comprises 20% to 45% by weight of at least one tackifier resin ii) and 20% to 45% by weight of at least one tackifier resin iii).

[0081] <Bio-based plasticizer> The hot melt adhesive composition contains a bio-based plasticizer c), and therefore its weight content is not zero.

[0082] The hot melt adhesive composition contains a bio-based plasticizer having a weight-average molecular weight of 2000 g / mol or more, in an amount of 12% by weight or less.

[0083] The hot melt adhesive composition preferably contains 1% to 10% by weight, more preferably 2% to 10% by weight, based on the total weight of the hot melt adhesive composition.

[0084] Preferably, if the hot melt adhesive composition contains a mixture of several bio-based plasticizers, the total content of the bio-based plasticizers is 12% by weight or less, based on the total weight of the hot melt adhesive composition.

[0085] The bio-based plasticizer has a weight-average molecular weight of 2000 g / mol or more, preferably 2500 g / mol or more, and more preferably in the range of 3000 g / mol to 12000 g / mol. Even more preferably, the bio-based plasticizer has a weight-average molecular weight in the range of 3000 g / mol to 6000 g / mol.

[0086] Bio-based plasticizers include animal fats, vegetable oils (e.g., canola oil, corn oil, soybean oil, epoxidized soybean oil, palm oil, peanut oil, olive oil, sunflower oil, rapeseed oil, jatropha oil, coconut oil, castor oil, etc.), lactic acid derivatives, modified versions thereof, fatty acid derivatives, and combinations thereof.

[0087] The weight-average molecular weight of bioplasticizers is determined by gel permeation chromatography using standards such as polystyrene. More specifically, the weight-average molecular weight of bioplasticizers is determined using a Waters Alliance instrument calibrated with polystyrene, at a flow rate of 1 ml / min at 35°C, with THF as the eluent.

[0088] In this specification, fatty acids refer to aliphatic carboxylic acids having at least one carboxyl group and may have one or more hydroxyl groups. Fatty acids are broadly classified into saturated fatty acids and unsaturated fatty acids. Saturated fatty acids are acids that do not have double or triple bonds in their carbon chain. Unsaturated fatty acids are acids that have one or more double or triple bonds in their carbon chain.

[0089] The fatty acids may be selected from the group consisting of butyric acid, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, erucic acid, ricinoleic acid, dihydrostearic acid, linoleic acid, eicostanic acid, 2-hydroxybutanoic acid, 3-hydroxybutanoic acid, 4-hydroxybutyric acid, 2-hydroxytetradecanoic acid, 3-hydroxytetradecanoic acid, 2-hydroxyhexadecanoic acid, 3-hydroxyhexadecanoic acid, 3-hydroxyoctadecanoic acid, 12-hydroxyoctadecanoic acid, 17-hydroxyoctadecanoic acid, and mixtures thereof.

[0090] Fatty acids can be derived from animal fats or from vegetable oils such as castor oil, sunflower oil, coconut oil, corn oil, canola oil, olive oil, palm oil, cottonseed oil, rapeseed oil, safflower oil, soybean oil, sesame oil, almond oil, avocado oil, hemp oil, and linseed oil. Vegetable oils are compositions containing triple esters (also called "triglycerides") of fatty acids and glycerol.

[0091] Therefore, the expression "fatty acids derived from vegetable oils" is intended to refer to fatty acids present in the molecular structure of these triglycerides. These fatty acids can be obtained in the form of isolated compounds by saponification, hydrolysis, or methanolysis of the triglycerides.

[0092] As used herein, a fatty acid derivative (fatty acid derivative) is a fatty acid-based component that contains at least one fatty acid group in its skeleton. Examples of fatty acid derivatives typically include compounds obtained by one or more chemical reactions involving fatty acids or natural compounds based on fatty acids.

[0093] Fatty acid derivatives include both unsaturated and saturated fatty acid derivatives.

[0094] Fatty acid derivatives are preferably selected from the group consisting of fatty acid amides, fatty acid esters, dimers or trimers of fatty acids, aliphatic alcohols, aliphatic aldehydes, aliphatic ketones, hydrogenated derivatives thereof, and mixtures thereof.

[0095] Preferably, the fatty acid derivative is neither a vegetable oil nor an animal fat.

[0096] More preferably, the fatty acid derivative F1 is selected from fatty acid esters, their hydrogenated derivatives, and mixtures thereof.

[0097] Hydrogenated derivatives may include both partially and fully hydrogenated derivatives.

[0098] Fatty acid amides can be any suitable amide compound derived from the reaction between a fatty acid and an ammonia or amine-containing compound (e.g., a compound containing a primary or secondary amine group).

[0099] Fatty acid esters may contain one or more ester functional groups.

[0100] Fatty acid esters typically include the following: Fatty acid esters resulting from a chemical reaction between a polyol and / or monool and one or more fatty acids or triglycerides, wherein the chemical reaction is selected from esterification and transesterification. The triglycerides are preferably derived from vegetable oils or animal fats.

[0101] Monoalcohols can be selected from methanol, ethanol, propanol, isopropanol, butanol, 2-ethylhexanol, phenol, aliphatic alcohols, and mixtures thereof. Polyols can be selected from glycerol, pentaerythritol, erythritol, sorbitol, ethylene glycol, propylene glycol, butylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,4-cyclohexanediol, trimethylolpropane, pentaerythritol, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, and mixtures thereof. Aliphatic alcohols are typically derived from fats and oils of plant origin, but can also be synthesized in animals and algae. Aliphatic alcohols may include oleyl alcohol, lauryl alcohol, stearyl alcohol, myristyl alcohol, palmitrail alcohol, nonadecyl alcohol, arachidyl alcohol, erucyl alcohol, etc.

[0102] A preferred example is an alkyl fatty acid ester. More preferably, alkyl fatty acid esters include methyl fatty acid esters, ethyl fatty acid esters, isopropyl fatty acid esters, isobutyl fatty acid esters, isoamyl fatty acid esters, and 2-ethylhexyl fatty acid esters.

[0103] • Fatty acid esters resulting from the functionalization (derivativeization) of another fatty acid ester (e.g., epoxidation; alkoxylation; acylation, etc., of a first fatty acid ester to provide a second fatty acid ester having an epoxy moiety). Monoglycerides, diglycerides, triglycerides, and mixtures thereof; • Fatty acid polyesters; and These mixtures.

[0104] Fatty acid polyesters are polymers / oligomers that contain an ester functional group in at least one repeating unit of their main chain.

[0105] Fatty acid polyesters typically include fatty acid oligoesters and fatty acid copolyesters.

[0106] Fatty acid polyesters preferably include fatty acid homopolymers, fatty acid copolymers (copolymers of different fatty acids), copolymers of fatty acids with monools and / or polyols, and mixtures thereof.

[0107] Fatty acid homopolymers can arise from the polycondensation of fatty acids containing hydroxyl groups, or mixtures of fatty acids containing at least one fatty acid having a hydroxyl group.

[0108] Preferably, the homopolymer is a homopolymer of ricinoleic acid.

[0109] Preferably, the bio-based plasticizer has a glass transition temperature of 0°C or below, more preferably -20°C or below, and even more preferably in the range of -80°C to -20°C. The glass transition temperature can be measured by DSC analysis in accordance with ISO 11357-1:1999. More preferably, the glass transition temperature is measured using the following conditions and parameters.

[0110] On a Mettler DSC 1 analyzer, cool 10 mg of the sample from 23°C to -80°C for 10 minutes under a nitrogen stream.

[0111] Next, the temperature is increased from -80°C to 200°C at a heating rate of 15°C / min (this is called the first heating step).

[0112] After reaching 200°C and stabilizing for 5 minutes, the temperature is reduced to -80°C at a cooling rate of 15°C / minute (this is called the cooling process).

[0113] After reaching -80°C and stabilizing for 10 minutes, the temperature is increased to 200°C at a heating rate of 15°C / minute (this is called the second heating step).

[0114] The glass transition temperature is measured relative to the second heating step and corresponds to the inflection point Ti,g. This value can be measured at the maximum value of the signal derivative.

[0115] Preferably, the bio-based plasticizer has an acid value in the range of 1 to 20, more preferably 3 to 20 mgKOH / g. The acid value can be measured according to DIN EN ISO 2114:2000 (AC:2005).

[0116] The bio-based plasticizer preferably has a biocarbon content of 60% or more, more preferably 80% or more, and more preferably 95% or more.

[0117] The bio-based plasticizer preferably has a viscosity in the range of 1000 to 5000 mPas, more preferably 1500 to 2500 mPas, at 25°C.

[0118] Preferably, the bio-based plasticizer is a fatty acid ester, more specifically a fatty acid polyester. Even more preferably, the bio-based plasticizer is a homopolymer of ricinoleic acid.

[0119] Suitable fatty acid oligoesters and polyesters are commercially available from Vandeputte, such as ricinoleic acid oligoester (acid value = 7 or 14 mg KOH / g), and VEOPUR 759035 (castor oil oligoester - the OH group on the side of castor oil is transesterified with the ester functional group of the castor oil itself, thereby eliminating glycerol, acid value = 3 mg KOH / g).

[0120] <Fatty acid derivative d)> The hot melt adhesive composition may contain at least one fatty acid derivative d) having a weight-average molecular weight of 1500 g / mol or less, preferably 1000 g / mol or less, and more preferably in the range of 250 g / mol to 1000 g / mol. More preferably, the fatty acid derivative d) has a weight-average molecular weight in the range of 300 g / mol to 800 g / mol.

[0121] The weight-average molecular weight is determined by gel permeation chromatography using a standard such as polystyrene. More specifically, the weight-average molecular weight is determined using a Waters Alliance instrument calibrated with polystyrene, at a flow rate of 1 ml / min at 35°C, with THF as the eluent.

[0122] The explanation for fatty acid derivative d) is the same as that for fatty acid derivatives of bio-based plasticizer c) above (excluding the average molecular weight).

[0123] Fatty acid derivative d) preferably has a biocarbon content of 60% or more, preferably 80% or more, and more preferably 95% or more.

[0124] The fatty acid derivative d) preferably has a viscosity of 5000 mPas or less at 25°C, and more preferably 3000 mPas or less at 25°C.

[0125] Examples of fatty acid derivatives (especially fatty acid esters) may include commercially available RADIA 7916 (methyl stearate, acid value 0.4 mg KOH / g) or RADIA 7195 (isopropyl stearate, acid value 0.1 mg KOH / g) or RADIA 7231 (isopropyl oleate) sold by OLEON, or Esterol A (methyl ester of a linear fatty acid) sold by Arkema.

[0126] Preferably, the fatty acid derivative d) is a fatty acid ester resulting from a chemical reaction between a fatty acid ester, more preferably a polyol and / or monool, and one or more fatty acids (or triglycerides), wherein the chemical reaction is selected from esterification and transesterification.

[0127] More preferably, the fatty acid derivative d) is selected from fatty acid alkyl esters and mixtures thereof.

[0128] Preferably, in the hot melt adhesive composition, the total weight content of the bio-based plasticizer c) and the fatty acid derivative d) is 12% or less by weight, based on the total weight of the hot melt adhesive composition.

[0129] <Stabilizer> The hot melt adhesive composition also preferably comprises at least one stabilizer, more preferably at least one antioxidant.

[0130] The hot melt adhesive composition contains a stabilizer in an amount of about 0 to about 5% by weight, preferably 0 to about 3% by weight, more preferably about 0.1 to about 3% by weight, and more preferably about 0.1 to 2% by weight, based on the total weight of the hot melt adhesive composition.

[0131] Appropriate stabilizers are incorporated to protect the polymers from the effects of thermal and oxidative degradation that typically occur during the manufacture and application of the adhesive composition and during the normal exposure of the final product to the surrounding environment, thereby helping to protect the entire adhesive system. Such degradation usually manifests as deterioration of the appearance, physical properties, and performance characteristics of the hot melt adhesive composition.

[0132] Applicable stabilizers, more specifically antioxidants, include high molecular weight hindered phenols and polyfunctional phenols, such as sulfur and phosphorus-containing phenols. Hindered phenols are well known to those skilled in the art and can be characterized as phenolic compounds that also contain sterically bulky groups adjacent to their phenolic hydroxyl group. In particular, a tertiary butyl group is generally substituted on the benzene ring at at least one ortho position relative to the phenolic hydroxyl group. The presence of these sterically bulky substituted groups near the hydroxyl group slows down its stretching frequency and, correspondingly, its reactivity; therefore, this steric hindrance provides the stabilizing properties of the phenolic compound. Representative hindered phenols include 1,3,5-trimethyl-2,4,6-tris(3-5-di-tert-butyl-4-hydroxybenzyl)benzene; pentaerythritol tetrakis-3(3,5-di-tert-butyl-4-hydroxyphenyl)propionate; n-octadecyl-3(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 4,4'-methylenebis(4-methyl-6-tert-butylphenol); 2,6-di-tert-butylphenol; 6-(4-Hyd Examples include roxyphenoxy)-2,4-bis(n-octylthio)-1,3,5-triazine; 2,3,6-tris(4-hydroxy-3,5-di-tert-butyl-phenoxy)-1,3,5-triazine; di-n-octadecyl-3,5-di-tert-butyl-4-hydroxybenzylphosphonate; 2-(n-octylthio)ethyl-3,5-di-tert-butyl-4-hydroxybenzoate and sorbitol hexa-3(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

[0133] The performance of these antioxidants can be further enhanced by using (1) synergists such as thiodipropionates and phosphates, for example; diaryl thiodipropionate (DLTDP); and (2) chelating agents and metal deactivators, such as ethylenediaminetetraacetic acid, its salts, and disalithyralpropylenediimine.

[0134] Suitable antioxidants include those marketed under trade names such as Irganox(R)1010 (tetrakis(methylene(3,5-di-ter-butyl-4-hydroxyhydrocinnamate))methane), Irgafos(R)168 (tris(2,4-di-tert-butylphenyl)phosphate), and Irganox(R)PS800 (propanoic acid, 3,3'-thiobis-1,1'-didodecyl ester) from BASF, Chinox(R)1010 (pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate)) from Shuangjian, Evernox(R)1010 and Everfos(R)168 from Everspring Chemical, and Songwon as Songnox(R)10 and 1680 from Songwon.

[0135] <Other additives> The hot melt adhesive composition may further contain at least one other additive in an amount of preferably 0 to 5% by weight, for example, 0.1 to 5% by weight, relative to the total weight of the adhesive composition.

[0136] Additives may be selected from the group consisting of inert colorants (e.g., titanium dioxide), fillers (e.g., talc, calcium carbonate, clay, silica, mica, wollastonite, feldspar, aluminum silicate, alumina, hydrated alumina, glass microspheres, ceramic microspheres, thermoplastic microspheres, and mixtures thereof), surfactants, additional polymers other than styrene block copolymers, crosslinking agents, nucleating agents, reactive compounds, flame retardant inorganic or organic agents, ultraviolet (UV) and / or infrared (IR) light absorbers, UV and / or IR fluorescent agents, waxes, and mixtures thereof. Other optional additives are well known in the art.

[0137] The additional polymer may be selected from the group consisting of polyolefins, amorphous poly-alpha-olefins, ethylene-vinyl acetate polymer (EVA), polyamides, and mixtures thereof. The hot melt adhesive may contain at least one additional polymer in an amount of about 0% to about 5% by weight relative to the total weight of the composition. However, preferably, the holt melt composition does not contain additional polymers.

[0138] The wax may be selected from the group consisting of microcrystalline wax, paraffin wax, polyethylene wax, polypropylene wax, by-product polyethylene wax, and Fischer-Tropsch wax.

[0139] Preferably, the holt melt composition contains wax.

[0140] Preferably, the hot-melt adhesive composition does not contain mineral oils such as naphthenic oil or paraffinic oil.

[0141] Preferably, the hot-melt adhesive composition does not contain polyolefins, and more preferably does not contain additional polymers other than styrene block copolymers.

[0142] <Hot Melt Adhesive Composition> The hot melt adhesive composition may have a Brookfield viscosity at 163°C of about 2000 to about 10000 mPa.s, preferably about 3000 to about 9000 mPa.s. The Brookfield viscosity may be measured at a temperature of about 163°C using a Spindle 27 Brookfield viscometer according to the standard method ASTM D-3236.

[0143] The biocarbon content of the hot melt adhesive is preferably 60% or more, more preferably 65% ​​or more, and even more preferably 70% or more.

[0144] The hot melt adhesive composition is advantageous in that it exhibits at least one of the following characteristics: ·Creep retention of 20% or less, more preferably 15% or less, and even more preferably 10% or less; ·Young's modulus of 2 MPa or more, more preferably 4 MPa or more; ·Storage modulus (G') at 25°C of 100 kPa or more, more preferably 500 kPa or more; ·Good adhesive properties; and ·Good cohesive strength.

[0145] Creep retention, Young's modulus, and storage modulus are measured as described in the experimental section.

[0146] <Method for preparing a hot melt adhesive composition> The present invention also relates to a method for preparing the hot melt adhesive composition as described above.

[0147] A hot-melt adhesive composition may be prepared by mixing a styrene block polymer component, at least one tackifying resin, and a bio-based plasticizer in a molten state. Any other component or additive of the composition, as described above, in particular at least one stabilizer, may be mixed with the above components.

[0148] The hot-melt adhesive composition of the present invention can be produced using any of the techniques known in the art. Preferably, the mixing step is carried out at a temperature of 120 to 160°C. The components are mixed for at least several hours, typically at least 3 hours, preferably 3 to 6 hours.

[0149] The hot-melt adhesive composition according to the present invention can be prepared in the presence of oxygen molecules (such as in an air atmosphere) or, preferably in an inert atmosphere, such as carbon dioxide or nitrogen, in order to limit potential degradation due to oxidation reactions.

[0150] A method for preparing the hot melt adhesive composition according to the present invention is preferably, • The first step involves melting and mixing styrene block polymer components and a bio-based plasticizer. • A second step involves adding a tackifying resin to the mixture obtained in the previous step while stirring. Includes.

[0151] As described above, other useful optional components or additives that may be present in the hot melt adhesive composition according to the present invention may be added at any step of the method according to the present invention.

[0152] <Use> The present invention also relates to the use of the hot melt adhesive composition described above in forming various other applications and structures, such as permanent bonding, temporary bonding (e.g., peelable and repositionable adhesive applications), medical wound dressings (e.g., wound care products), bandages, surgical pads, drapes, gowns, labels, tapes, filters, and combinations thereof.

[0153] The present invention also relates to the use of the hot melt adhesive composition as defined above as a positioning adhesive, a core adhesive, or an adhesive for fixing elastic members, more preferably as an adhesive for fixing elastic members.

[0154] The present invention relates to the use of a hot-melt adhesive composition as defined above for joining substrates.

[0155] More specifically, the present invention relates to the use of a hot-melt adhesive composition as defined herein for joining an elastic material between two separate substrates.

[0156] Another object of the present invention is a laminate comprising at least one elastic material and at least two substrates, wherein the elastic material is inserted between the two substrates and covered with the hot melt adhesive composition of the present invention.

[0157] A "laminated material" should be understood as a multilayer material, that is, a material with at least two layers.

[0158] A material is typically considered elastic if it exhibits a high percentage elastic recovery (i.e., low percentage permanent strain) after the application of a biasing force. Ideally, an elastic material is characterized by a combination of three temperature-independent properties: low percentage permanent strain and low percentage stress or load relaxation. Specifically, (1) there should be little or no stress or unloading relaxation while the material is being stretched, and (2) there should be full or high recovery to the original dimensions after the stretching, biasing, or strain has ceased. Thus, an elastic material is typically a polymer that, without diluent and independent of any crimp (if in fibrous form), has a break elongation of over 100%, and when stretched to twice its length, held for one minute, and then released, shrinks to less than 1.5 times its original length within one minute of release. Examples of such polymers include, but are not limited to, natural rubber or synthetic rubber, segmented polyurethanes (including polyurethane urea) such as polyether urethane and polyester urethane, polyether esters, elastomer polyethylene and polypropylene, and polyetheramides.

[0159] Preferably, the elastic material is selected from the group consisting of elastomer fibers, tapes, films, strips, coatings, ribbons and / or sheets, and substantially linear ethylene polymers.

[0160] Examples of elastic materials include spandex (e.g., Lycra(R) spandex and Lycra(R) XA, and spandex with little or no lubricating finish).

[0161] The elastic material may include spandex or melt-spun elastomer, or natural or synthetic rubber in the form of fibers or strips less than about 10 mm wide.

[0162] The U.S. International Trade Commission defines spandex as a manufactured fiber in which the material forming the fiber consists of a long-chain synthetic polymer composed of at least 85% by weight of segmented polyurethane. Lycra(R) spandex is known to exhibit nearly ideal temperature-independent elastic properties.

[0163] Preferably, one or more elastic materials are inserted between a first substrate selected from polyolefin films such as polyethylene or polypropylene film and a second substrate selected from nonwoven materials such as nonwoven polypropylene or nonwoven polyethylene.

[0164] Preferably, the laminate of the present invention comprises at least two, preferably at least three, elastic materials inserted between two substrates.

[0165] Preferably, the elastic material is in the form of strands of elastic material having a linear density in the range of 235 dtx to 1520 dtx.

[0166] The present invention also relates to a method for manufacturing a laminate according to the present invention, comprising the following steps: • A step of providing the first substrate, • A process of providing at least one elastic material, • A step of applying the hot melt adhesive composition according to the present invention onto at least one elastic material. - A step of bringing (one or more) elastic materials covered with a hot melt adhesive composition into contact with a first substrate. • A step of bringing a second substrate into contact with (one or more) elastic materials. • Compression process between two rollers This includes methods.

[0167] Preferably, the elastic material is stretched before the application of the adhesive composition, preferably so that the length of the elastic material is in the range of 2 to 4 times its resting (i.e., unstretched) length, and ideally the stretching is carried out so that the length of the elastic material is 3 times longer than its resting length.

[0168] Preferably, the hot melt adhesive composition is applied at a temperature in the range of 130°C to less than 160°C, preferably in the range of 145°C to 155°C, and ideally at a temperature of about 150°C.

[0169] Preferably, the compression level of the laminate in the nip roll is about 1 bar.

[0170] The hot-melt adhesive composition of the present invention can be applied to an elastic material by either contact applications or spraying applications.

[0171] Contact coating uses a contact nozzle from which the adhesive composition can be applied straight onto an elastic material. If the elastic material is in the form of strands, the hot melt adhesive composition can be applied straight onto the elastic material along the strands. If several elastic strands are present in the laminate, the adhesive composition can be applied separately onto each strand. To apply the hot melt adhesive composition onto several elastic strands simultaneously, the same apparatus may be equipped with several nozzles. An example of a method for applying an adhesive composition using contact coating is described in U.S. Patent Application Publication No. 2012 / 0258246.

[0172] An example of a device for contact coating is the Allegro(R) device from Nordson.

[0173] According to this embodiment, the hot melt adhesive composition is applied at a speed in the range of 100 to 600 m / min. Preferably, the amount of the hot melt adhesive composition may be in the range of 10 to 100 mg per meter of elastic strand, preferably 20 to 50 mg / m of elastic strand. Preferably, the amount of the hot melt adhesive composition is expressed per meter of elastic strand under stretching.

[0174] The present invention also relates to an article comprising a laminate as disclosed above. The article is preferably a disposable absorbent article, more preferably selected from the group consisting of disposable diapers, training pants, adult incontinence products (pads or briefs), sanitary care products (napkins or pads) and medical masks, and more preferably selected from the group consisting of adult incontinence products (pads or briefs) and sanitary care products (napkins or pads). More preferably the article is a disposable diaper.

[0175] All descriptions, embodiments, and preferred embodiments defined above for hot melt adhesive compositions are hereby applied to disposable absorbent articles without needing to repeat them.

[0176] The scope disclosed herein includes both its lower and upper limits. For example, the expression “range x to y” or “x to y” includes both x and y.

[0177] All preferred embodiments of the components of a hot melt adhesive composition (e.g., preferred weight percentages, or preferred properties of the components) can be combined with each other without the need to explicitly describe all combinations. [Examples]

[0178] The following examples illustrate the present invention without limiting it.

[0179] <Materials used in the examples> The components used in the examples are listed below. Vector(R)4411S from TSRC, linear SIS (with 44% styrene content and 0% diblock); • Polyester P from Vandeputte (an oligoester produced by polycondensation from pure ricinoleic acid, having an acid value of 12-16 mg KOH / g and a hydroxyl value of up to 30 mg KOH / g); • IRGANOX 1010 from BASF, a phenolic antioxidant; Dercolyte(R) M105 from DRT-Pinova: A β-pinene polyterpene resin produced from the polymerization of a mixture of α and β-pinene, having a ring sphere softening point range of 105°C. Its renewable carbon content is 100%. • SYLVALITE(R)9000 from Kraton: A fully hydrogenated rosin ester resin with a ring sphere softening point range of 70°C; • CALPRENE(R) 540 from DYNASOL is a linear SBS copolymer (having a 40% styrene content and 0% diblock); KRATON(R)MD1156 from KRATON is a linear SBS copolymer (having a 40% styrene content and 0% diblock); GLOBALPRENE(R)3545 from LCY is a linear SBS copolymer (having a 45% styrene content and 65% diblock); ESTEREOL A (from ARKEMA) is a bio-based mixture of methyl esters of straight-chain fatty acids; • SCG's POLYETHYLENE WAX LP1040T: A refined polyethylene homopolymer wax derived from a proprietary HDPE process.

[0180] <Preparation of adhesive composition> The compositions of Example 1 in Table 1 are prepared individually by simple mixing of their components. One or more polymers, one or more plasticizers, and one or more stabilizers are mixed together and heated at 135°C until all are dissolved as a homogeneous mixture. Then, one or more resins are added at the same temperature until all are dissolved as a homogeneous mixture. Finally, the mixture is cooled, collected, and used as is.

[0181] <Preparation of elastic laminates using the Allegro nozzle coating apparatus> The laminate is prepared as follows. A machine operating continuously at a line speed of approximately 200 m / min is used as the lamination device, and this machine is sold by Nordson under the name Coater CTL 4400.

[0182] In this machine, the coating nozzle is an Allegro nozzle.

[0183] The two base materials used are as follows: • 20cm wide, with an untreated surface, 22g / m² 2 A breathable PE film, and • Same width 10g / m 2 This spunbond hydrophobic nonwoven fabric sheet is made from polypropylene (PP) fibers.

[0184] Elastic material used: Elastic material brand (Invista) with 800 dtex

[0185] After stretching the elastic material to 300% elongation, hot-melt adhesive was applied to the elastic strands using Allegro coating. This was then applied to the nonwoven fabric as the primary substrate, followed by the PE film, with an open time of 0.5 seconds and compression of 1 bar. The coating temperature was set to 150°C, and the application rate was approximately 25-35 mg / lm / strand on the elastic strands.

[0186] <Creep resistance measured initially and after curing at 23°C and 55°C> Next, the resulting laminate is assembled into a roll and left at ambient temperature and 50% relative humidity for 24 hours.

[0187] <Creep evaluation> A creep resistance test was performed on the laminate prepared above. The laminate comprises elastic strands and an inelastic substrate. A segment of the laminate approximately 350 mm long was fully stretched and firmly attached to a piece of plexiglass. A mark was made at a length of 300 mm, and the elastic strand was cut at the mark while maintaining the inelastic substrate in its stretched shape. The test sample (laminated) was placed in an oven at 38°C for 4 hours. Under these conditions, the stretched elastic strand can shrink to a certain distance. After 4 hours, the distance between the ends of the elastic strand was measured. The ratio of the final length to the initial length, defined as creep retention and expressed as a percentage (%), is a measure of the adhesive's ability to retain the elastic strand. %creep retention = [final length) / initial length] * 100%

[0188] A higher percentage of creep retention is better. A percentage of creep retention below 80% is unacceptable.

[0189] The assembled assemblies obtained after lamination were cured at 55°C for the specified times, then at 23°C for 24 hours, and the creep resistance after 4 weeks at 55°C was measured and expressed as a percentage, except that the measurement was taken at 23°C.

[0190] <Storage modulus G'> Dynamic mechanical analysis (DMA) A rheometer was used to apply shear stress to the adhesive, and the resulting strain (shear deformation) response was measured as a function of the temperature cooling gradient.

[0191] Equipment: A TA Instruments DHR-1 rheometer that applies small vibrational stress to achieve a constant vibrational strain within the linear viscoelastic region (e.g., 1%) of the adhesive.

[0192] General protocol: An adhesive was placed between a Peltier plate, which functions as a fixed lower plate, and an upper plate with a radius R of 10 mm, connected to the drive shaft of a motor to generate shear stress. The gap between the two plates has a height H of 1,000 μm. The Peltier plate controls the temperature of the material (+ / - 0.5°C).

[0193] Test run: After setting the temperature to 80°C and then to GAP0, set the temperature to the starting temperature (i.e., 150°C); Place adhesive (1 cm³) onto the Peltier plate; Lower the upper plate to a gap of 1,700 μm until the upper plate makes contact with the adhesive; Remove any excess material and set the temperature to 120°C; Lower the upper plate to a gap of 1,000 μm; Set the temperature to a starting temperature of 120°C, the constant measurement strain to 1%, the constant frequency to 1Hz, and the cooling rate to 6°C / min (from 120°C to -10°C); After the test is completed, melt the adhesive, lift the upper plate, and remove the adhesive from both the Peltier plate and the upper plate; and • Return the temperature to room temperature.

[0194] Results: The storage modulus was calculated every 30 seconds throughout the entire cooling process. The G' value at 25°C was determined accordingly.

[0195] Young's modulus The adhesive sample is melted before being poured into a dogbone-shaped mold. The resulting dogbone specimen consists of two large grip zones connected by a narrow test zone measuring 30 × 3 × 3 mm. The dogbone is tested on a tensile testing machine that applies a constant strain rate of 300 mm / min until the specimen breaks. To obtain Young's modulus from the stress-strain curve, a line is drawn using the least squares method at a point located between the beginning of the curve and the yield point. The slope of the resulting line is the value of Young's modulus.

[0196] [Example 1]: Hot melt adhesive composition The hot melt adhesive composition was prepared as described above.

[0197] Table 1: Hot melt adhesive compositions and their properties

[0198] [Table 1]

[0199] Compositions C1 to C6 are hot-melt adhesive compositions according to the present invention. Advantageously, compositions C1 to C6 exhibit a Young's modulus higher than 2 MPa, preferably higher than 3 MPa, compared to comparative compositions C7 and C8, which exhibit a lower Young's modulus, particularly lower than 1.5 MPa.

[0200] Regarding the storage modulus G': Compositions C1-C6 (the present invention) advantageously yield a storage modulus higher than 100 kPa. Furthermore, compositions C1-C6 advantageously provide excellent creep retention, particularly 4%-10%, while comparative compositions C7 and C8 yield poor creep retention (41% and >50%, respectively).

Claims

1. A hot melt adhesive composition, -a) Styrene block polymer components; -b) At least one tackifying resin; -c) Bio-based plasticizers having a weight-average molecular weight of 2000 g / mol or more Includes, The hot melt adhesive composition contains a styrene content of 8.0% or more, and A hot melt adhesive composition in which the total weight content of bio-based plasticizer c) is 12% by weight or less based on the weight of the hot melt adhesive composition.

2. The hot melt adhesive composition according to claim 1, wherein the styrene block polymer component comprises a styrene block copolymer selected from the group consisting of SB, SI, SEB, SEP, SBBS, SBS, SEBS, SEPS, SEEPS, SIBS, SIS, random block SBR, random block SIR, and mixtures thereof.

3. A hot melt adhesive composition according to any one of claims 1 or 2, wherein the styrene block polymer component comprises SIS or SBS copolymer.

4. The hot melt adhesive composition according to any one of claims 1 to 3, wherein the hot melt adhesive composition comprises 5% to 35% by weight, preferably 10% to 30% by weight, and more preferably 10% to 30% by weight, of a styrene block polymer component based on the total weight of the hot melt adhesive composition.

5. At least one tackifying resin, -i) Natural and modified rosins, such as gum rosin, wood rosin, tall oil rosin, distilled rosin, dimerized rosin and polymerized rosin, as well as their hydrogenated derivatives; -ii) Glycols, glycerols and pentaerythritol esters of natural and modified rosins, and their hydrogenated derivatives, -iii) Polyterpene homopolymers and their hydrogenated derivatives; -iv) Copolymers of terpenes and diene monomers, and their hydrogenated derivatives; -v) Phenolic-modified terpene resin; - and mixtures thereof A hot melt adhesive composition according to any one of claims 1 to 4, selected from the group consisting of the following.

6. The hot melt adhesive composition according to claim 5, wherein the hot melt adhesive composition comprises a mixture of at least one tackifying resin ii) and at least one tackifying resin iii).

7. The hot melt adhesive composition according to any one of claims 1 to 6, wherein the hot melt adhesive composition comprises 50% to 90% by weight, preferably 55% to 80% by weight, and more preferably 55% to 70% by weight of tackifying resin (or a mixture of tackifying resins if multiple tackifying resins are present in the hot melt adhesive composition) based on the total weight of the hot melt adhesive composition.

8. A hot melt adhesive composition according to any one of claims 1 to 7, wherein the styrene content of the hot melt adhesive composition is in the range of 8.0% to 15.0%, more preferably 9.0% to 12.0%.

9. The hot melt adhesive composition according to any one of claims 1 to 8, wherein the bio-based plasticizer has a weight-average molecular weight in the range of 3,000 g / mol to 12,000 g / mol, more preferably in the range of 3,000 g / mol to 6,000 g / mol.

10. A hot melt adhesive composition according to any one of claims 1 to 9, wherein the bio-based plasticizer is selected from animal fats, vegetable oils (e.g., canola oil, corn oil, soybean oil, epoxidized soybean oil, palm oil, peanut oil, olive oil, sunflower oil, rapeseed oil, jatropha oil, coconut oil, castor oil, etc.), lactic acid derivatives, modified versions thereof, fatty acid derivatives, and combinations thereof.

11. The hot melt adhesive composition according to any one of claims 1 to 10, wherein the bio-based plasticizer has an acid value in the range of 1 to 20, preferably 3 to 20 mg KOH / g.

12. A hot melt adhesive composition according to any one of claims 1 to 11, wherein the bio-based plasticizer has a viscosity in the range of 1,000 to 5,000 mPas, preferably 1,500 to 2,500 mPas, at 25°C.

13. The hot melt adhesive composition according to any one of claims 1 to 12, wherein the bio-based plasticizer is a fatty acid derivative, preferably a fatty acid ester, more preferably a fatty acid polyester, and even more preferably a homopolymer of ricinoleic acid.

14. The hot melt adhesive composition according to any one of claims 1 to 13, wherein the hot melt adhesive composition contains 1% to 10% by weight, preferably 2% to 10% by weight, of a bio-based plasticizer c) based on the total weight of the hot melt adhesive composition.

15. The hot melt adhesive composition according to any one of claims 1 to 14, wherein the hot melt adhesive composition comprises at least one fatty acid derivative d) having a weight-average molecular weight of 1500 g / mol or less, preferably 1000 g / mol or less, and more preferably in the range of 250 g / mol to 1000 g / mol.

16. The hot melt adhesive composition according to any one of claims 1 to 15, wherein the hot melt adhesive composition has a Brookfield viscosity at 163°C of about 2,000 to about 10,000 mPa·s, preferably about 3,000 to about 9,000 mPas.

17. The hot melt adhesive composition according to any one of claims 1 to 16, wherein the biocarbon content of the hot melt adhesive is 60% or more, preferably 65% ​​or more, and more preferably 70% or more.

18. Hot melt adhesive composition, - Creep retention of 20% or less, more preferably 15% or less, and even more preferably 10% or less; and / or - Young's modulus of 2 MPa or more, more preferably 4 MPa or more; and / or - Storage modulus (G') at 25°C, with a pressure of 100 kPa or higher, more preferably 500 kPa or higher. A hot melt adhesive composition according to any one of claims 1 to 17, comprising the above.

19. Use of the hot melt adhesive composition according to any one of claims 1 to 18 as a positioning adhesive, a core adhesive, or an adhesive for fixing elastic members, more preferably as an adhesive for fixing elastic members.

20. A laminate comprising at least one elastic material and at least two substrates, wherein the elastic material is inserted between the two substrates and covered with a hot melt adhesive composition according to any one of claims 1 to 18.

21. An article comprising the laminate according to claim 19, preferably a disposable absorbent article.

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