laminate

Abstract

To provide a laminate of a hot melt adhesive and a non-woven fabric including a specific cellulose-based fiber, which has excellent adhesiveness and strength over time and is used for bonding non-woven fabrics including a cellulose-based fiber and for bonding a non-woven fabric including a cellulose-based fiber and other unwoven fabrics.SOLUTION: There is provided a laminate which has a non-woven fabric layer (I) constituted by a non-woven fabric α including a cellulose-based fiber and a non-woven fabric layer (II) constituted by an optional non-woven fabric in this order, wherein the non-woven fabric layer (I) and the non-woven fabric layer (II) are bonded via a hot melt adhesive β, a mean deviation (SMD) of surface roughness of a surface on a side in contact with the non-woven fabric (II) via the hot-melt adhesive β in the non-woven fabric α is 2.3 or less or 3.0 or more, the hot melt adhesive β includes a component (A), a thermoplastic elastomer and a component (B), a tackifier constituted by including a component (B1) and a component (B2), the component (B1) is a terpene-based tackifier, a rosin-based tackifier or a fully hydrogenated hydrocarbon-based tackifier and the component (B2) is a non-hydrogenated hydrocarbon-based tackifier or a partially hydrogenated hydrocarbon-based tackifier.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a laminate. [Background technology]

[0002] Currently, it is mainly used as a material for sanitary products such as diapers and napkins. Plastics are used. However, in the future, these materials will be replaced by environmentally friendly materials. It is expected that replacement with alternative materials will become more common.

[0003] Currently, the main material used for these sanitary products is nonwoven fabric made from petroleum. These are expected to be replaced by nonwoven fabrics made from natural materials in the future.

[0004] The surface condition of a nonwoven fabric made from a petroleum-based material is different from that of a nonwoven fabric made from a natural material. For this reason, the adhesives used in the manufacture of conventional sanitary products are replaced with nonwoven fabrics made from natural materials. If used in the mating process, proper adhesion cannot be achieved.

[0005] When laminating nonwoven fabrics used in sanitary products, the nonwoven fabrics In addition to providing good adhesion at the time, the adhesiveness is maintained even after a long period of time (hereinafter In this specification, this property is referred to as "strength over time." For this purpose, in addition to the surface characteristics of the nonwoven fabric, the selection of the adhesive to be combined with it is also important. do.

[0006] Patent Document 1 also describes a method for removing uneven surfaces such as those used in sanitary products. A hot melt adhesive is disclosed that purportedly has good adhesive properties.

[0007] In addition, Patent Document 2 describes a method for producing a hydrophilic substrate such as a cellulose substrate or a cotton substrate. A hot melt adhesive that is said to have good adhesive properties is disclosed. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] International Publication No. 2021 / 039118 [Patent Document 2] JP 2007-169531 A Summary of the Invention [Problem to be solved by the invention]

[0009] However, the hot melt adhesive disclosed in Patent Document 1 is made from a natural base material. It is unclear whether it will be a good adhesive for nonwoven fabrics made from natural base materials. It is unclear whether any consideration has been given to the strength over time when the material is bonded.

[0010] In addition, the hot melt adhesive disclosed in Patent Document 2 is also described in the examples as being made of PET. The adhesiveness between the film and cotton fabric has been confirmed, but the adhesiveness between nonwoven fabrics made of natural materials or The adhesiveness of nonwoven fabrics made of natural materials to other nonwoven fabrics is unclear, and the strength of the adhesiveness over time is unknown. It is unclear whether the design has been given consideration to temperature.

[0011] In view of the above circumstances, an object of the present invention is to provide a method for manufacturing a film having excellent adhesiveness and strength over time. In addition, nonwoven fabrics containing cellulosic fibers may be used together, or a nonwoven fabric containing cellulosic fibers may be used together with other nonwoven fabrics. Hot melt adhesives and certain cellulosic fibers used for bonding to nonwoven fabrics The aim is to find a laminate with a nonwoven fabric. [Means for solving the problem]

[0012] As a result of intensive research conducted by the present inventors to solve the above problems, The present invention employs a combination of a nonwoven fabric containing cellulose fiber and a hot melt adhesive having a specific composition. It has been found that by using the above-mentioned compound, excellent adhesiveness and strength over time can be obtained. Based on this finding, the inventors conducted further research and have now completed the present invention.

[0013] That is, the present invention provides the following laminate. Section 1. A nonwoven fabric layer (I) composed of a nonwoven fabric α containing cellulosic fibers and an arbitrary nonwoven fabric The nonwoven fabric layer (I) and the nonwoven fabric layer (II) are formed in this order. II) is bonded via hot melt adhesive β. The nonwoven fabric α is in contact with the nonwoven fabric layer (II) via the hot melt adhesive β. The surface roughness mean deviation (SMD) of the side surface is 2.3 or less or 3.0 or more; The hot melt adhesive β comprises component (A) a thermoplastic elastomer and component (B1) and component (B2), The component (B1) is a terpene-based tackifier, a rosin-based tackifier, or a fully hydrogenated carbonized It is a hydrogen-based tackifier, The component (B2) is an unhydrogenated hydrocarbon-based tackifier or a partially hydrogenated hydrocarbon-based tackifier. A laminate comprising: Section 2. The nonwoven fabric α has a basis weight of 15 to 40 g / m 2 Item 2. The laminate according to item 1, Section 3. Item 1 or 2, wherein the cellulosic fiber contained in the nonwoven fabric α is cotton or rayon. The laminate according to claim 1. Section 4. Item 3. The laminate according to item 1 or 2, wherein (B2) is a partially hydrogenated hydrocarbon-based tackifier. Section 5. Item 3. The laminate according to item 1 or 2, wherein the hot melt adhesive β contains wax. Section 6. The hot melt adhesive β is a hot melt adhesive for absorbent articles, The laminate described above. Effect of the Invention

[0014] The laminate according to the present invention thus obtained is excellent in adhesiveness and strength over time. [Brief description of the drawings]

[0015] [Figure 1] FIG. 2 is an explanatory diagram of the production of laminates in Examples and Comparative Examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] In this specification, "containing" means "comprise" or "consists essentially of" The term "consist essentially of" includes both "consist of" and "consist of only." In addition, in this specification, when a numerical range is indicated as "A to B", it means A or more and B or less. means.

[0017] (1. Laminate) The laminate of the present invention comprises a nonwoven fabric layer (I) composed of a nonwoven fabric α containing cellulosic fibers. and a nonwoven fabric layer (II) made of any nonwoven fabric in this order, ) and the nonwoven fabric layer (II) are bonded via a hot melt adhesive β, and the nonwoven fabric α the surface of the surface that comes into contact with the nonwoven fabric layer (II) via the hot melt adhesive β in The hot melt adhesive has a mean deviation of roughness (SMD) of 2.3 or less or 3.0 or more. β contains component (A) a thermoplastic elastomer, and components (B1) and (B2). The composition comprises a component (B) tackifier, and the component (B1) is a terpene-based tackifier, The component (B2) is a rosin-based tackifier or a fully hydrogenated hydrocarbon-based tackifier. The tackifier is characterized in that it is an unhydrogenated hydrocarbon-based tackifier or a partially hydrogenated hydrocarbon-based tackifier. It is something.

[0018] The laminate of the present invention is provided with one or more additional nonwoven fabrics (nonwoven fabrics similar to nonwoven fabric α). ) may be a separate hot melt adhesive (a hot melt adhesive similar to the hot melt adhesive β) It is also preferable to laminate the layers by bonding them together using a heat-melting adhesive. This is a new embodiment.

[0019] A step of bonding the nonwoven fabric constituting the laminate of the present invention via a hot melt adhesive. Before or after, the nonwoven fabric or laminate may be embossed, perforated, or otherwise processed. is also a preferred embodiment.

[0020] (2. Nonwoven fabric layer (I)) The nonwoven fabric layer (I) is composed of a nonwoven fabric α containing cellulosic fibers. The content of cellulosic fibers in the nonwoven fabric is preferably 5% by mass or more based on 100% by mass of the nonwoven fabric. 20 quality It is more preferable that the content is 50% by mass or more, and further preferably 50% by mass or more. The content of the cellulose fiber is preferably 100% by mass in the nonwoven fabric α (100% by mass). In addition, it is preferable that the nonwoven fabric α is composed only of cellulosic fibers. may be also possible.

[0021] As such cellulose-based fibers, a wide variety of known fibers can be used. Examples of the polyester fiber include, but are not limited to, cotton, rayon, and lyocell.

[0022] The basis weight of nonwoven fabric α is 15g / m 2 It is preferable that the thickness is 25 g / m or more. 2 That's all. It is more preferable that the weight of the nonwoven fabric α is 15 g / m 2 As a result, it has good water retention. The weight of the nonwoven fabric α is 40 g / m 2 It is preferable that Preferably 35g / m 2 It is more preferable that the weight of the nonwoven fabric α is 40 g / m or less. 2 Below By being lower than the above, good breathability can be imparted.

[0023] In the nonwoven fabric α constituting the nonwoven fabric layer (I), the nonwoven fabric layer is bonded to the nonwoven fabric layer via the hot melt adhesive β. (II) The surface roughness mean deviation (SMD) of the surface in contact with the If the value is greater than 2.3 or less than 3.0, the surface smoothness is poor. The contact area of ​​the surface increases, causing a deterioration in the texture. Or something like that.

[0024] In this specification, the mean deviation (SMD) of the surface roughness of the nonwoven fabric surface is specifically defined as follows: It is defined as something that is measured and calculated as follows.

[0025] The measuring device used is a surface tester (e.g., Kato Tech KES-FB4-A). The measurement conditions were a temperature of 23°C, humidity of 50%, and a roughness sensor with a thickness of 0.5 mm. A test piece (20cm x 20cm) of the nonwoven fabric to be tested was used as a sensor for measuring changes in the material. SPEED: 1.0mm / sec, Roughness static load: 10.0gf, 100g paperweight used A force is applied to the nonwoven fabric, and the MD direction of the nonwoven fabric is measured.

[0026] The test procedure is to make sure that the MD direction of the nonwoven fabric and the sensor movement direction are the same. The piece is set and a tension of 100g is applied in the MD direction of the nonwoven fabric to measure the surface roughness. The test was carried out at 12 randomly selected points on the nonwoven fabric, and the average value was obtained as the SMD. This shall be the case.

[0027] In the nonwoven fabric α constituting the nonwoven fabric layer (I), the nonwoven fabric layer is bonded to the nonwoven fabric layer via the hot melt adhesive β. (II) The surface roughness mean deviation (SMD) of the surface in contact with the It is preferable that the ratio is 2.0 or less, more preferable that the ratio is 1.8 or less. In addition, the SMD is preferably 0 or more, and more preferably 1.0 or more. stomach.

[0028] On the other hand, the hot melt adhesive β is bonded to the nonwoven fabric α constituting the nonwoven fabric layer (I). The surface roughness mean deviation (SMD) of the surface in contact with the woven fabric layer (II) is 3.0 or more. It is preferable that the ratio is 3.2 or more, and more preferable that the ratio is 3.5 or more. The SMD is preferably 7.0 or less, and more preferably 6.5 or less. More preferred.

[0029] (3. Nonwoven fabric layer (II)) The nonwoven fabric layer (II) is composed of any nonwoven fabric. Nonwoven fabrics can be widely used, and among them, nonwoven fabrics containing cellulosic fibers or cellulose Of course, the nonwoven fabric α described above is preferably made of only cellulose fiber. It may also be a similar nonwoven fabric.

[0030] In addition, there are also other petroleum-based materials that have traditionally been used in sanitary products. A nonwoven fabric may also be used.

[0031] (4. Hot melt adhesive β) The hot melt adhesive β comprises component (A) a thermoplastic elastomer, and components (B1) and and component (B2), which is a tackifier.

[0032] (4.1. Component (A) Thermoplastic Elastomer) The thermoplastic elastomer component (A) is not particularly limited, and examples thereof include styrene-based block copolymers. Polymer, olefin block copolymer, polyurethane block copolymer, polyester Among these, the peel strength of hot melt adhesives is From the viewpoint of further improving the above, a styrene-based block copolymer is preferred.

[0033] Styrenic block copolymers are produced by blocking vinyl aromatic hydrocarbons and conjugated diene compounds. It is a block copolymer obtained by block copolymerization.

[0034] Vinyl aromatic hydrocarbons are aromatic hydrocarbon compounds that contain a vinyl group. Specific examples of aromatic hydrocarbons include styrene, o-methylstyrene, and p-methylstyrene. styrene, p-tert-butylstyrene, 1,3-dimethylstyrene, α-methylstyrene Examples of the vinyl ether include vinyl ether, vinyl naphthalene, and vinyl anthracene. Among these, styrene is preferred. Vinyl aromatic hydrocarbons may be used alone or in combination of two or more. It is possible.

[0035] The conjugated diene compound is a diolefin compound having at least one pair of conjugated double bonds. Conjugated diene compounds include, specifically, 1,3-butadiene, 2-methyl-1,3 -Butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-penta Among these, 1,3-butadiene, 2 The preferred conjugated diene compounds are 1,3-methyl-1,3-butadiene (isoprene). These may be used alone or in combination of two or more.

[0036] The styrene block copolymer is preferred because it can exhibit better peel strength. It is preferable that the block copolymer is a non-hydrogenated styrene-based block copolymer. Examples of styrene-based block copolymers include styrene-butadiene block copolymers ( SB), styrene-butadiene-styrene block copolymer (SBS), styrene-iso Polystyrene-styrene block copolymer (SIS), styrene-butadiene-styrene-butadiene Diene block copolymers (SBSB) and the like. These styrene block copolymers The compounds may be used alone or in combination of two or more. Among ethylene-based block copolymers, it has superior peel strength. From these viewpoints, styrene-butadiene-styrene block copolymer (SBS) is preferred.

[0037] The styrene skeleton content in the styrene block copolymer provides better peel strength. Therefore, the amount of the styrene block copolymer is preferably 10 to 70% by mass. % by mass is preferred, and 30 to 60% by mass is more preferred.

[0038] In this specification, the content of a styrene skeleton in a styrene-based block copolymer means the content of a styrene skeleton in a styrene-based block copolymer. The percentage (mass%) of styrene blocks in styrene-based block copolymers. The method for calculating the content of styrene skeleton in a block copolymer is, for example, JIS K6 Examples of the method include the use of proton nuclear magnetic resonance spectroscopy and infrared spectroscopy in accordance with 239.

[0039] In the present invention, the component (A) is a thermoplastic elastomer, which can exhibit better peel strength. The plastic elastomer is a styrene-based block copolymer, and The polymer preferably comprises a styrene-butadiene-styrene block copolymer (SBS). stomach.

[0040] In the present invention, the styrene block copolymer is heated at a high temperature for a long time (for example, 160 In order to improve the thermal stability when heated at 35°C for 72 hours, the asymmetric styrene-isobutyric acid It is preferred that the composition does not contain a soprene-styrene block copolymer.

[0041] In the present invention, the component (A) thermoplastic elastomer is a styrene-based block copolymer. and the styrene-based block copolymer is an asymmetric styrene-isoprene-styrene block copolymer. It is preferred that the composition does not contain a block copolymer.

[0042] In the present invention, the styrene-based block copolymer is a styrene-butadiene-styrene block copolymer. It contains an asymmetric styrene-isoprene-styrene block copolymer (SBS) It is more preferred that the polymer does not contain any acrylic copolymer.

[0043] As used herein, the term "asymmetric styrene-isoprene-styrene block copolymer" refers to a The term "symmetrical" means that the styrene skeleton content is different in the styrene phases at both ends.

[0044] As the styrene-based block copolymer, a wide variety of known commercially available products can be used. For example, Asahi Kasei Corporation's product name "Asaprene T-439" (containing a styrene skeleton) Proportion: 45% by mass, Asahi Kasei Corporation product name "Asaprene T-438" (containing styrene skeleton) Proportion: 35% by mass, Asahi Kasei Corporation product name "Asaprene T-436" (containing styrene skeleton) Proportion: 30% by mass, Kraton Polymers' product name "DX-405" (styrene skeleton) Content: 24% by mass, Kraton Polymers' product name "D-1155" (styrene Skeleton content: 40% by mass, Kraton Polymers product name "D-1118" (steel styrene skeleton content: 30% by mass), CHIMEI's "PB5502" (styrene skeleton content The content ratio is 32% by mass. These commercially available products can be used alone or in combination of two or more kinds. can be used in combination.

[0045] Content of thermoplastic elastomer (A) in 100% by mass of the hot melt adhesive of the present invention is preferably 10 to 35 mass % from the viewpoint of exhibiting better peel strength, The content is more preferably 15 to 30% by mass, and further preferably 18 to 25% by mass.

[0046] The content of the styrene-based block copolymer in 100% by mass of the hot melt adhesive of the present invention is preferably 10 to 35 mass % from the viewpoint of exhibiting even better peel strength. %, more preferably 15 to 30 mass %, and even more preferably 18 to 25 mass %.

[0047] (4.2. Component (B) Tackifier) The tackifier component (B) is composed of components (B1) and (B2). The tackifier B may be formed of only the component (B1) and the component (B2).

[0048] Component (B1) is a terpene-based tackifier, a rosin-based tackifier, or a fully hydrogenated hydrocarbon. It is a tackifier.

[0049] The terpene-based tackifier may be a terpene resin (monoterpene, diterpene, triterpene, etc. terpene, polyperethane, etc.), terpene phenol resin, aromatic modified terpene resin, etc. These terpene tackifiers can be used alone or in combination of two or more. It can be used in combination.

[0050] The terpene-based tackifier may be a known commercially available tackifier having an acid value of 15 mgKOH / g or less. A wide variety of commercially available products can be used. For example, the commercially available product is Product name: "YS Resin TO-105" (acid value: 0 mgKOH / g), product manufactured by Kraton Examples include "SYLVARES TRM1115" (acid value: 0 mgKOH / g).

[0051] As the rosin-based tackifier, from the viewpoint of exhibiting better adhesion (tack), At least one of natural rosin and an esterified product of the natural rosin (rosin ester resin) It is preferable to use a rosin ester resin, and it is more preferable to use a rosin ester resin.

[0052] Examples of the natural rosin include tall rosin, gum rosin, and wood rosin. These natural rosins can be used alone or in combination of two or more. can be done.

[0053] Examples of the rosin ester resin include rosin glycerin ester and rosin pentaerythritol. Erythritol ester, rosin methyl ester, rosin ethyl ester, rosin butyl ester ester, rosin ethylene glycol ester, etc. These rosin esters The resins can be used alone or in combination of two or more kinds.

[0054] The rosin-based tackifier is a known commercially available product having an acid value of 15 mgKOH / g or less. The commercially available products include, for example, the product name " Super Ester A100 (acid value: 5 mgKOH / g), a product name of Arakawa Chemical Industries Co., Ltd. Pine Crystal KE-100 (acid value: 6 mg KOH / g), a product manufactured by Kraton Name: "SYLVALITE 9100" (acid value: 7mgKOH / g), manufactured by Arakawa Chemical Industries Co., Ltd. Examples include the product name "Super Ester A75" (acid value: 5mgKOH / g). The commercially available products may be used alone or in combination of two or more.

[0055] Examples of the fully hydrogenated hydrocarbon tackifier include C5 petroleum resins, C9 petroleum resins, and the like. Hydrogen is added to petroleum resins such as C5C9 petroleum resins and dicyclopentadiene petroleum resins. An example of a C5 petroleum resin is a fully hydrogenated petroleum resin. C9 petroleum resin is a petroleum resin made from the C9 fraction of petroleum. C5C9 petroleum resin is a petroleum resin made from C5 and C9 fractions of petroleum. Examples of C5 fractions include cyclopentadiene, isoprene, and pentane. The 9th fraction includes styrene, vinyltoluene, indene, etc.

[0056] Component (B2) is an unhydrogenated hydrocarbon-based tackifier or a partially hydrogenated hydrocarbon-based tackifier. do.

[0057] Specific examples of the tackifier of component (B2) include the above-mentioned C5 petroleum resins and C9 petroleum resins. Resins, C5C9 petroleum resins, dicyclopentadiene petroleum resins and other petroleum resins, unhydrogenated or Partially hydrogenated hydrocarbon tackifiers can be exemplified.

[0058] In this specification, the ring and ball softening point of the tackifier (B) is in accordance with JIS K 6863. Temperature is measured in accordance with

[0059] The content of the tackifier (B) in 100% by mass of the hot melt adhesive β is In order to further improve the degree of oxidation, the content is preferably 30 to 65 mass %, more preferably 35 to 6 The content is preferably 0% by mass, and more preferably 40 to 55% by mass.

[0060] The content of the tackifier (B) is preferably 0.1 to 0.5% by weight, more preferably 0.5 to 0.5% by weight, and most preferably 0.5 to 0.5% by weight. Preferably, the amount is 150 to 350 parts by mass, more preferably 100 parts by mass of the thermoplastic elastomer. The amount is preferably 200 to 300 parts by mass.

[0061] In the present invention, the mass parts of the thermoplastic elastomer (A) are A, and the adhesive (B) is When the mass part of the imparting agent is B, the ratio represented by B / A is preferably 1.5 to 3.5. , and more preferably 2.0 to 3.0.

[0062] The amount of component (B1) in the total amount of components (B1) and (B2) is 100% by mass. In order to obtain good adhesion, the content is preferably 50% by mass or less, and more preferably 40% by mass or less. It is more preferable to do so.

[0063] On the other hand, the amount of component (B1) in the total amount of components (B1) and (B2) is 100% by mass. The content is preferably 5% by mass or more, and more preferably 10% by mass or more. By setting the blending amount of (B1) to 5% by mass or more, excellent strength over time can be obtained. .

[0064] (4.3. Various Additives) The hot melt adhesive β may be any of various types as required, as long as it does not substantially impede the object of the present invention. The composition may contain additives. Examples of the additives include plasticizers, antioxidants, ultraviolet absorbers, Examples include liquid rubbers, waxes, and particulate fillers.

[0065] Examples of the plasticizer include naphthenic process oil and paraffinic process oil. In order to further improve heat stability and peel strength, naphthenic process oil is preferred. These plasticizers may be used alone or in combination of two or more. can be done.

[0066] As the plasticizer, a wide variety of known commercially available products can be used.

[0067] As a commercially available naphthenic process oil, for example, the product name " KN4010", Idemitsu Kosan's product name "Diana Fresia N28", Idemitsu Kosan's product name Product name: "Diana Fresia U46", Nynas product name: "Nyflex222B", etc. Examples include

[0068] For example, Idemitsu Kosan's product name "Diamond Oil" is a commercially available paraffin-based process oil. Product name: Diana Process Oil PW32, Product name: Diana Process Oil PW90, Product name: Diana "Diana Process Oil PS32", product name "Diana Process Oil PS90"; Wit Examples include the product "Kaydol" manufactured by Co., Ltd.

[0069] When the hot melt adhesive β contains a plasticizer, the content of the plasticizer in 100% by mass of the hot melt adhesive is The upper limit of the content of the plasticizer is preferably 40% by mass, more preferably 30% by mass, and even more preferably More preferably, it is 25% by weight.

[0070] When the hot melt adhesive β contains a plasticizer, the content of the plasticizer in 100% by mass of the hot melt adhesive is The lower limit of the content of the plasticizer (C) is preferably 1% by mass, more preferably 5% by mass. .

[0071] As the antioxidant, a wide variety of known antioxidants can be used, for example, 2,6-di-t-butyl ether. 4-methylphenol, n-octadecyl-3-(4'-hydroxy-3',5' -di-t-butylphenyl)propionate, 2,2'-methylenebis(4-methyl-6 -t-butylphenol), 2,2'-methylenebis(4-ethyl-6-t-butylphenol) 2,4-bis(octylthiomethyl)-o-cresol, 2-t-butyl-6 -(3-t-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenylacrylamide lylate, 2,4-di-t-amyl-6-[1-(3,5-di-t-amyl-2-hydro 2-[1-(2-hydroxy-3,5-phenyl)ethyl]phenyl acrylate di-tert-pentylphenyl)]acrylate, tetrakis [methylene-3-(3, 5-di-t-butyl-4-hydroxyphenyl)propionate]methane and other phenols Antioxidants: Dilauryl thiodipropionate, Lauryl stearyl thiodipropionate Sulfur compounds such as pentaerythritol tetrakis(3-laurylthiopropionate) Antioxidants: Tris(nonylphenyl)phosphite, tris(2,4-di-t-butyl) These antioxidants include phosphorus-based antioxidants such as phenyl phosphite. These antioxidants may be used alone or in combination of two or more. Among these antioxidants, phenol-based antioxidants are preferred from the viewpoint of further improving heat stability.

[0072] As the antioxidant, a wide variety of known commercially available products can be used. As a commercially available product of the agent, for example, the product name " "Evernox10" etc.

[0073] When the hot melt adhesive β contains an antioxidant, 100% by mass of the hot melt adhesive The upper limit of the content of the antioxidant in the composition is preferably 5% by mass, more preferably 4% by mass. More preferably, it is 3% by mass.

[0074] When the hot melt adhesive β contains an antioxidant, 100% by mass of the hot melt adhesive The lower limit of the content of the antioxidant in the composition is preferably 0.1 mass%, more preferably 0.5 % by mass, and more preferably 1% by mass.

[0075] As the ultraviolet absorbing agent, a wide variety of known ultraviolet absorbing agents can be used. For example, 2-(2'-hidroxyethyl) 2-(2'-hydroxy-3'-hydroxyphenyl)benzotriazole ,5'-t-butylphenyl)benzotriazole, 2-(2'-hydroxy-3',5 Benzotriazoles such as ('-di-t-butylphenyl)-5-chlorobenzotriazole UV absorbers: benzophenone-based ultraviolet absorbers such as 2-hydroxy-4-methoxybenzophenone Ultraviolet ray absorbers;Salicylic acid ester-based ultraviolet ray absorbers;Cyanoacrylate-based ultraviolet ray absorbers; hindered amine light stabilizers. These ultraviolet absorbers can be used alone as follows: Or two or more of them can be used in combination.

[0076] As the liquid rubber, a wide variety of known liquid rubbers can be used, such as liquid polybutene, liquid polybutene, etc. These liquid rubbers include butadiene, liquid polyisoprene, and hydrogenated resins thereof. Each of these may be used alone or in combination of two or more.

[0077] As the particulate filler, a wide variety of known particulate fillers can be used, for example, calcium carbonate. , kaolin, talc, titanium oxide, mica, styrene beads, etc. The sub-fillers may be used alone or in combination of two or more.

[0078] When the hot melt adhesive β contains the above-mentioned various additives, the hot melt adhesive 100 The content of the various additives in terms of mass % is preferably 5 mass % or less.

[0079] The nonwoven fabric used in the laminate of the present invention can be produced by a conventional method.

[0080] The hot melt adhesive β may be manufactured by a standard method, and there is no particular limitation on the manufacturing method. For example, components (A), (B), and, if necessary, the various additives described above may be mixed in a heating device. and a method in which the mixture is charged into a stirring kneader equipped with a heating device and kneaded while being heated.

[0081] The heating temperature during kneading is not particularly limited, but is preferably 100 to 200° C., and more preferably The kneading time is not particularly limited, and is preferably 40 to 140 minutes, more preferably 120 to 180° C. The time is preferably 60 to 120 minutes.

[0082] When obtaining a laminate, the hot melt adhesive β can be applied by a known application method. It can be widely used, for example, spiral spray coating, slot coater coating, curtain Examples include plate coating, roll coater coating, omega coating, dot coating, and bead coating. .

[0083] As a coating device for coating the hot melt adhesive β to the bonding portion, a known coating device is used. It can be widely used, for example, hot melt applicators. For example, the REKA handgun TR8 manufactured by Suntool is an example of a REKA gun. 0LCD (spray)" etc.

[0084] The hot melt adhesive β is applied to a porous material made of natural materials such as cellulose-based materials and cotton-based materials. Since it can exhibit excellent adhesion to hydrophilic nonwoven fabrics, it has excellent water absorption properties. The adhesive is preferably used for bonding adherends together in the manufacture of absorbent articles. It is preferable that the adhesive be made of a hot melt adhesive β.

[0085] Absorbent articles are designed to absorb bodily fluids such as blood, urine, sweat, pus, gastric juices, saliva, and nasal mucus. The water-absorbent articles include, for example, disposable diapers, sanitary napkins, bread, etc. Tee liners, incontinence pads, portable toilets, portable waste disposal bags, animal waste disposal sheets These include hospital gowns, surgical gowns, wound dressings, first aid bandages, and materials for preserving the freshness of meat and fish. Among these, the hot melt adhesive of the present invention is particularly suitable for use in paper diapers, sanitary napkins, It is suitable for use as a panty liner.

[0086] Disposable diapers are made of a liquid-impermeable back sheet made of a polyolefin resin film, etc., and an impermeable A liquid-permeable top sheet made of woven fabric or the like and a layer that diffuses the liquid that has permeated through the top sheet. A liquid diffusion sheet, an absorbent body disposed between the liquid diffusion sheet and a liquid-impermeable back sheet, The absorbent material is basically made up of the following components: In order to prevent this, the absorbent body is used with its surface covered with absorbent paper such as tissue. In addition, in the case of absorbent articles, elastic members such as rubber are attached in a stretchable manner, so that the article can be easily worn. The structure is designed to fit around the legs and waist of the person and prevent waste from leaking out. There are.

[0087] In the production of such paper diapers, the hot melt adhesive β is used, for example, in the manufacture of cellulose-based In order to integrate the porous substrates by adhesion, a cellulose-based porous substrate and a nonwoven fabric, etc. It is preferably used for bonding and integrating with other porous substrates.

[0088] A method of bonding nonwoven fabric layers (I) and (II) to form a laminate using a hot melt adhesive β The method is not particularly limited and any known method can be used. For example, The hot melt adhesive β is applied to the nonwoven fabric layer (I) or (II), and then the applied hot melt adhesive A method is used in which another nonwoven fabric layer is placed on the melt adhesive and then pressed together. can be done.

[0089] Although the embodiments of the present invention have been described above, the present invention is not limited to these examples. However, it is to be understood that the present invention can be embodied in various forms without departing from the spirit and scope of the present invention. This is an argument. EXAMPLES

[0090] Hereinafter, the embodiment of the present invention will be described in more detail based on examples. However, the present invention is not limited to the above.

[0091] Manufacture of hot melt adhesive β Thermoplastic elastomers, tackifiers, plasticizers, antioxidants, and The mixture and various additives were added to a mixing and kneading machine equipped with a heating device, heated to 145°C, and mixed for 90 minutes. The mixture was kneaded for 24 hours to obtain hot melt adhesive Production Examples 1 to 19.

[0092] [Table 1]

[0093] [Table 2]

[0094] [Table 3]

[0095] Preparation of adhesive sheet Silicone oil coated release PET film (50μm) The above hot melt adhesive β was melted at 140°C and applied to a thickness of 10 μm and a width of 90 mm. Then, release paper (thickness 15 μm) was attached to the opposite side of the release PET film. Thereafter, the adhesive sheet was placed in an atmosphere of 23°C and 50% relative humidity. The hot melt adhesive was then left to stand for 24 hours to harden. The adhesive sheet A was obtained by cutting the sheet into pieces each having a length of 5 mm and a length of 40 mm.

[0096] Preparation of nonwoven fabric Cotton nonwoven fabrics I to III and rayon nonwoven fabric were prepared. For the standard deviation (SMD), a surface tester (e.g., Kato Tech KES-FB4 As a result of measuring the thickness of the cotton nonwoven fabric I as described above, the thickness of the cotton nonwoven fabric I was 1.623, Ton nonwoven fabric II is 3.179, cotton nonwoven fabric III is 6.931, and rayon nonwoven fabric is 4. It was measured at .857.

[0097] Fabrication of the laminate As shown in FIG. 1, the nonwoven fabrics I to III and the rayon nonwoven fabric were cut by 70 mm in the MD direction and 70 mm in the CD direction. The release paper of each of the above adhesive sheets was removed and the nonwoven fabric was The cloth was attached to the surface on which the SMD measurement was performed, and a 500g roll was placed on top of it and measured at 5mm / s The adhesive sheet was then rotated back and forth at a speed of 1000 s. Then, the release film was peeled off to expose the adhesive sheet. A second nonwoven fabric was attached to the adhesive surface, with the surface on which the SMD measurement was performed. In both the examples and the comparative examples, the two nonwoven fabrics sandwiching the adhesive sheet were made of the same material. A 100 g roll was placed on the obtained laminate and rolled at a speed of 5 mm / sec. It went back and forth once.

[0098] Adhesion evaluation test over time A tensile tester (Shimadzu Corporation AGS-X) was used to test the laminates of each of the examples and comparative examples. The nonwoven fabric was subjected to a T-peel test at a tensile strength of 100 mm / min in the MD direction. The maximum test force was measured. The measurement was carried out three times, and the average value was taken as the test result for the maximum convex test force. The measurement was carried out after each of the Examples and Comparative Examples was produced, and the temperature was 23°C and the humidity was 50% for 2 h. After leaving it for 4 hours, it was left at 50℃ for 1 week and 2 weeks. From this point on in the specification, the measurement results after 24 hours of standing are referred to as "initial strength," and those after one week and two weeks. The measurement results after standing are called "1W intensity" and "2W intensity", respectively. The evaluation criteria are as follows, regarding the average value obtained by performing the above maximum convex test force measurement three times: The adhesiveness was evaluated according to the following criteria. It was determined that. <Evaluation criteria> Less than 2.00N × 2.00N or more but less than 2.50N △ 2.50N or more but less than 3.00N 〇 3.00N or more ◎

[0099] Evaluation test results As shown in Tables 4 to 15 below, in the laminates of Examples 1 to 52, after one or two weeks, In contrast, the laminates of Comparative Examples 1 to 24 showed no such excellent adhesion. No excellent adhesion was observed.

[0100] [Table 4]

[0101] [Table 5]

[0102]

Table 6

[0103]

Table 7

[0104]

Table 8

[0105]

Table 9

[0106]

Table 10

[0107]

Table 11

[0108]

Table 12

[0109]

Table 13

[0110]

Table 14

[0111]

Table 15

Claims

1. The nonwoven fabric layer (I) is made of a nonwoven fabric α containing cellulosic fibers, and the nonwoven fabric layer (II) is made of any nonwoven fabric, in this order, and the nonwoven fabric layer (I) and the nonwoven fabric layer (II) are bonded to each other via a hot melt adhesive β, The hot melt adhesive β comprises a component (A) a thermoplastic elastomer and a component (B) a tackifier comprising a component (B1) and a component (B2), The component (B1) is a terpene-based tackifier, a rosin-based tackifier, or a fully hydrogenated hydrocarbon-based tackifier, A laminate, wherein the component (B2) is an unhydrogenated hydrocarbon-based tackifier or a partially hydrogenated hydrocarbon-based tackifier.

2. The nonwoven fabric α has a basis weight of 15 to 40 g / m ２ The laminate according to claim 1 ,

3. 3. The laminate according to claim 1, wherein the cellulosic fibers contained in the nonwoven fabric α are cotton or rayon.

4. The laminate according to claim 1 or 2, wherein the hot melt adhesive β contains a wax.

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