Multilayer laminate, coffee capsule, and adhesive

Abstract

In order to provide a biodegradable laminate which does not require the use of an adhesive for the adhesion between a polyvinyl alcohol resin layer and a biodegradable resin layer, a multilayer laminate is provided that contains a layer (A) having a thermoplastic resin (a) and a polysaccharide (c) in a specific combination in contact with a layer (B) having a polyvinyl alcohol resin (b).

Description

Multi-layer laminates, coffee capsules, adhesives

[0001] The present invention relates to a multilayer laminate, more specifically to a multilayer laminate that has excellent adhesiveness without the use of an adhesive. The present invention also relates to a coffee capsule having this multilayer laminate and an adhesive.

[0002] In recent years, plastic waste has become a problem due to its significant environmental impact, including its impact on ecosystems, the generation of harmful gases during combustion, and global warming due to the large amount of heat generated by combustion. Therefore, environmentally friendly products are being sought for plastic packaging materials used for food, pharmaceuticals, and the like. For example, the performance required for environmentally friendly packaging materials includes barrier properties that can block gases and extend shelf life, as well as materials and configurations that have a low environmental impact. Among multilayer laminates with barrier properties, biodegradable laminates formed by laminating polyvinyl alcohol-based resins and biodegradable resins have attracted attention due to their excellent gas barrier properties and biodegradability. Examples of such barrier laminates include those disclosed in Patent Documents 1 to 4.

[0003] JP 2023-145418 A JP 2019-181943 A JP 2019-181877 A International Publication No. WO19 / 049798

[0004] As shown in Patent Documents 1 to 4, in conventional barrier laminates having a polyvinyl alcohol-based resin layer, because the polyvinyl alcohol-based resin is a water-soluble resin, it is necessary to form layers having a thermoplastic resin on both sides of the layer having the polyvinyl alcohol-based resin. However, because hydrophilic resins and hydrophobic resins do not adhere to each other, it is necessary to provide separate adhesive layers. This imposes restrictions on the layer structure of the barrier laminate, and the restrictions on the layer structure impose restrictions on the equipment that can be used during production. Furthermore, multilayer laminates in which multiple layers are laminated with separate adhesive layers have the problem of poor recyclability because it is difficult to separate the different materials.

[0005] Furthermore, from the viewpoint of environmental consideration, biodegradable barrier laminates are desired, and in a barrier laminate having a polyvinyl alcohol-based resin layer and a thermoplastic resin layer, the adhesive layer provided between the two is naturally required to be biodegradable. However, in laminates using conventionally known adhesives, the adhesive contains a solvent, and therefore the packaging materials that can be used with such laminates are limited from a hygienic standpoint.

[0006] Under these circumstances, the present invention provides a barrier laminate that does not require the use of an adhesive to bond the polyvinyl alcohol-based resin layer and the thermoplastic resin layer.

[0007] In view of these circumstances, the present inventors have conducted extensive research and have found that a multilayer laminate in which a layer containing a specific combination of thermoplastic resin and polysaccharide is abutted against a layer containing a polyvinyl alcohol-based resin as a thermoplastic resin layer improves the adhesion between the layers, and allows the two to be bonded together without the need for an adhesive.

[0008] That is, the present invention has the following aspects. [1] A multilayer laminate comprising a layer (A) containing a thermoplastic resin (a) and a layer (B) containing a polyvinyl alcohol-based resin (b) in contact with each other, wherein the layer (A) contains 20 to 280 parts by mass of a polysaccharide (c) per 100 parts by mass of the thermoplastic resin (a), the content of the polysaccharide (c) in the layer (A) being 25% by mass or more, and the ratio (αA / αB) of the thickness (αA) of the layer (A) to the thickness (αB) of the layer (B) being 0.7 to 1,000. [2] The multilayer laminate according to [1], wherein the polysaccharide (c) contains cellulose. [3] A multilayer laminate comprising a layer (A) containing a thermoplastic resin (a) and a layer (B) containing a polyvinyl alcohol-based resin (b) in contact with each other, wherein the layer (A) contains 20 to 280 parts by mass of cellulose per 100 parts by mass of the thermoplastic resin (a). [4] The multilayer laminate according to [3], wherein the ratio (αA / αB) of the thickness (αA) of layer (A) to the thickness (αB) of layer (B) is 0.01 to 1000. [5] The multilayer laminate according to any one of [1] to [4], which has at least two layers (A), each of which abuts on both sides of layer (B). [6] The multilayer laminate according to any one of [1] to [5], wherein the melting point of the thermoplastic resin (a) is 220°C or lower. [7] The multilayer laminate according to any one of [1] to [6], wherein the thermoplastic resin (a) contains a biodegradable resin. [8] The multilayer laminate according to any one of [1] to [7], wherein the thickness (αB) of layer (B) is 0.1 to 100 μm. [9] The multilayer laminate according to any one of [1] to [8], wherein the thickness (αA) of layer (A) is 1 to 1000 μm.

[10] The multilayer laminate according to any one of [1] to [9], wherein the thickness (αB) of the layer (B) is 0.1 to 100 μm.

[11] The multilayer laminate according to any one of [1] to

[10] , wherein the polysaccharide (c) or the cellulose has a fibrous structure, and the fiber length is 5 μm or more and 150 μm or less.

[12] A coffee capsule having the multilayer laminate according to any one of [1] to

[11] .

[13] An adhesive containing 20 to 280 parts by mass of cellulose per 100 parts by mass of the thermoplastic resin (a).

[14] The adhesive according to

[13] , wherein the cellulose is fibrous, and the fiber length is 5 μm or more and 150 μm or less.

[15] The adhesive according to

[13] or

[14] , wherein the thermoplastic resin (a) contains a biodegradable resin.

[0009] The present invention does not require an adhesive to bond the layers of a multilayer laminate, and therefore has excellent adhesiveness and gas barrier properties. Furthermore, because no adhesive is required to bond the layers of a multilayer laminate, the degree of freedom in the layer structure of the multilayer laminate is increased, and there are no restrictions on the equipment that can be used during production, resulting in excellent convenience.

[0010] The present invention will be described below based on examples of embodiments for carrying out the present invention, but the present invention is not limited to the embodiments described below.

[0011] In this specification, "y and / or z (y and z are any configuration)" means at least one of y and z, and can mean three possibilities: y only, z only, or y and z. When "Y to Z" (Y and Z are any numbers) is expressed in this specification, it also means "Y or more and Z or less" unless otherwise specified, and also includes the meaning "preferably larger than Y" or "preferably smaller than Z". When "Y or more" (Y is any number) or "Z or less" (Z is any number) is expressed in this specification, it also includes the meaning "preferably larger than Y" or "preferably smaller than Z".

[0012] In this specification, the term "film" also includes "tape" and "sheet." In this specification, the term "main component" refers to a component that has a significant effect on the properties of the target object, and the content of the component is usually 50% by mass or more, preferably 55% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more, and may even be 100% by mass.

[0013] Embodiment (1) of the present invention is a multilayer laminate comprising a layer (A) containing a thermoplastic resin (a) and a layer (B) containing a polyvinyl alcohol (hereinafter sometimes abbreviated as "PVA")-based resin (b) in contact with each other, wherein the layer (A) contains 20 to 280 parts by mass of a polysaccharide (c) per 100 parts by mass of the thermoplastic resin (a), the polysaccharide content in the layer (A) is 25% by mass or more, and the ratio (αA / αB) of the thickness (αA) of the layer (A) to the thickness (αB) of the layer (B) is 0.7 to 1000. Embodiment (2) of the present invention is a multilayer laminate comprising a layer (A) containing a thermoplastic resin (a) and a layer (B) containing a polyvinyl alcohol-based resin (b) in contact with each other, wherein the layer (A) contains 20 to 280% by mass of cellulose per 100 parts by mass of the thermoplastic resin (a). In addition, the embodiment (1) and the embodiment (2) may be collectively referred to as the present embodiment. Each layer of the multilayer laminate will be described below.

[0014] <Thermoplastic Resin (a)> Examples of the thermoplastic resin (a) contained in layer (A) (hereinafter sometimes referred to as "Layer A" or "A") include olefin resins such as polyethylene and polypropylene; polystyrene; polyvinyl acetate; (meth)acrylic resins such as polyacrylate and polymethacrylate; halogenated vinyl resins such as polyvinyl chloride and polyvinylidene chloride; polyacrylonitrile; amide resins such as aliphatic polyamides and aromatic polyamides; polycarbonate; silicone resins; polyester resins such as polyethylene terephthalate and polybutylene terephthalate; ABS resins (acrylonitrile-butadiene-styrene resins) ), vinyl graft copolymer resins such as ACS resin (chlorinated polyethylene-acrylonitrile-styrene resin) and AES resin (acrylonitrile-ethylene-styrene resin); urethane resins; phenylene group-containing resins such as polyphenylene ether, polyphenylene oxide and polyphenylene sulfide; fluororesins; polyether resins such as polyether ether ketone, polyether ketone and polyether sulfone; polyvinyl ether resins; polyvinyl ketone resins; polyxylylene resins; polysulfone resins; polylactic acid, etc., but from the viewpoint of environmental consideration, biodegradable resins are preferred.

[0015] As used herein, "biodegradable" means satisfying the conditions specified in JIS K 6953-1:2011 (ISO 14855-1:2005). Examples of such biodegradable resins include polyester, polylactic acid, polyglycolic acid, polylactic acid-polyol copolymer, polylactic acid-polyglycolic acid copolymer, polycaprolactone, polylactic acid-polycaprolactone copolymer, polyorthoester, polyphosphazene, polyphosphate ester, polyhydroxybutyric acid, polymalic acid, polybutylene succinate, polybutylene adipate terephthalate, modified polyethylene terephthalate, polyvinyl alcohol, polyhydroxyalkanoate, bacterial cellulose, chitosan / cellulose / starch, esterified starch, poly-α-amino acid, collagen, gelatin, and starch. Of these, those having a polyester structure are preferred, and polyester is more preferred.

[0016] The thermoplastic resin (a) used in the present invention preferably has a melting point of 220°C or less, more preferably 190°C or less, more preferably 155°C or less, and even more preferably 130°C or less. A melting point within the above range is preferable because it allows the compounding temperature of the polysaccharide (c) and the thermoplastic resin to be low, thereby suppressing scorching and odor of the polysaccharide (c) due to heating. Note that PVA-based resins are thermoplastic resins and may be treated as biodegradable resins depending on the degree of saponification and polymerization, but in this embodiment, they are not included in the thermoplastic resin (a) used in layer A.

[0017] <Polysaccharide (c)> The layer (A) containing the thermoplastic resin (a) used in embodiment (1) of the present invention contains 20 to 280 parts by mass of the polysaccharide (c) per 100 parts by mass of the thermoplastic resin (a), and the polysaccharide content in the layer (A) is 25% by mass or more. That is, the polysaccharide (c) is a compound having a structure in which monosaccharides are linked by glycosidic bonds and containing multiple hydroxyl groups. Therefore, by setting a predetermined amount of the polysaccharide (c) in the layer (A) containing the thermoplastic resin (a), the hydroxyl groups in the polysaccharide (c) form hydrogen bonds with the hydroxyl groups in the PVA-based resin (b), and high adhesiveness can be achieved through interactions mediated by multiple hydrogen bonds.

[0018] The polysaccharide (c) of the invention used in embodiment (1) is preferably a simple polysaccharide composed of one type of monosaccharide, and examples of the simple polysaccharide include starch, dextrin, glycogen, cellulose, inulin, xylan, mannan, and galactan. Examples of the starch include raw starch, oxidized starch, cationized starch, phosphate-esterified starch, hydroxyethyl etherified starch, and enzyme-modified starch. Among the polysaccharides (c), cellulose and starch are preferred, and cellulose is particularly preferred.

[0019] The polysaccharide (c) used in embodiment (1) is contained in an amount of 20 parts by mass or more, preferably 25 to 280 parts by mass, more preferably 27 to 240 parts by mass, even more preferably 30 to 200 parts by mass, and particularly preferably 35 to 150 parts by mass, per 100 parts by mass of the thermoplastic resin (a). When the content of polysaccharide (c) contained in layer (A) containing thermoplastic resin (a) is 1 part by mass or more, this is preferable because it improves adhesion to the PVA-based resin layer. When the content of polysaccharide (c) contained in layer (A) containing thermoplastic resin (a) is 280 parts by mass or less, this is preferable because it improves the appearance of the laminate.

[0020] The polysaccharide (c) used in embodiment (1) is contained in the layer (A) containing the thermoplastic resin (a) in an amount of 25% by mass or more, more preferably 25 to 80% by mass, even more preferably 26 to 70% by mass, or even more preferably 27 to 60% by mass.

[0021] The shape of the polysaccharide (c) is not particularly limited, but fibrous or particulate polysaccharides are preferably used. That is, among polysaccharides (c), there are those that form long chains as polymers and have a fibrous structure by aggregation, such as cellulose, and those that have a branched structure and form a three-dimensional aggregate state and have a particulate structure, such as starch. In embodiment (1), however, from the viewpoint of further improving adhesiveness by bonding with the hydroxyl groups of the PVA-based resin (b), it is preferable for the polysaccharide (c) to have a fibrous or particulate shape, and cellulose that has a fibrous shape is particularly preferred.

[0022] [When the polysaccharide (c) is particulate] When the polysaccharide (c) is particulate, its 50% cumulative average fiber diameter (D50) is preferably 2 μm or more, more preferably 4 μm or more, and even more preferably 5 μm or more. The average particle diameter is preferably 50 μm or less, more preferably 40 μm or less, and even more preferably 28 μm or less. It is preferable that the D50 of the particulate polysaccharide (c) is within the above range, since this improves the appearance of the laminate. In this specification, the 50% cumulative average fiber diameter (D50) of the polysaccharide (c) is a value measured by a known method. Specifically, the particle size distribution is measured by dry measurement using a laser diffraction / scattering particle size distribution analyzer, and the particle diameter at the cumulative 50% point on a volume basis is the 50% cumulative average fiber diameter (D50).

[0023] The details of embodiment (2) described below also include preferred forms of the polysaccharide (c) in embodiment (1).

[0024] The layer (A) containing the thermoplastic resin (a) used in embodiment (2) of the present invention contains 20 to 280 parts by mass of cellulose per 100 parts by mass of the thermoplastic resin (a). Various known celluloses can be used. Furthermore, cellulose-based materials such as paper powder, wood flour, pulp, baca, sawdust, wood fiber, and rice husks may also be added. Examples of such celluloses include natural cellulose derived from plants, modified celluloses such as carboxymethyl cellulose, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, and hydroxypropylmethyl cellulose, and regenerated cellulose. Furthermore, the cellulose is not limited to highly refined celluloses such as wood pulp and non-wood pulp, and may also be less refined. Examples of low-purity cellulose include wood pulp such as softwood pulp and hardwood pulp; non-wood pulp such as rice pulp, kenaf pulp, hemp (linen) pulp, mulberry pulp, bagasse pulp, straw pulp, cotton pulp, bamboo pulp, fruit pulp, rag pulp, and linter pulp; waste paper pulp; and synthetic fiber pulp.

[0025] The pulp can be broadly classified into mechanical pulps such as groundwood pulp (GP), refiner ground pulp (RGP), thermomechanical pulp (TMP), and chemithermomechanical pulp (CTMP) based on the manufacturing method; chemical pulps such as kraft pulp (KP), sulfide pulp (SP), and alkaline pulp (AP); and unbleached pulp and bleached pulp, etc., but in the present embodiment, any of these can be used as cellulose.

[0026] The cellulose used in this embodiment may be bound to and / or mixed with hemicellulose and / or lignin, or may be cellulose from which the hemicellulose and / or lignin have been removed. Examples of cellulose from which the hemicellulose and / or lignin have been removed include cellulose obtained by chemically treating cellulose bound to and / or mixed with hemicellulose and / or lignin with caustic soda or the like to remove the hemicellulose and lignin, thereby obtaining high-purity cellulose.

[0027] The cellulose purity of the cellulose is preferably 40% or more, more preferably 50% or more, even more preferably 60% or more, and particularly preferably 75% or more. By keeping the cellulose purity within the above range, coloration and odor generated when heated in the kneading and molding processes can be effectively suppressed.

[0028] [When the cellulose is fibrous] The fiber length of the fibrous cellulose is preferably 5 μm or more, more preferably 8 μm or more, even more preferably 10 μm or more, and particularly preferably 15 μm or more. The fiber length is preferably 150 μm or less, more preferably 120 μm or less, even more preferably 100 μm or less, particularly preferably 60 μm or less, and particularly preferably 23 μm or less. When the fiber length of the fibrous cellulose is within the above range, the resin pressure can be sufficiently reduced, which is preferable because the appearance of the laminate tends to be good. In this specification, the fiber length of the fibrous cellulose is a value measured by a known method. For example, the fiber length can be determined by image analysis of a scanning electron microscope photograph, measuring the long side of a plurality of randomly selected cellulose-based fibers as the fiber length and the short side as the fiber diameter, and then calculating the arithmetic average of these.

[0029] The fiber diameter of the fibrous cellulose is preferably 1 μm or more, more preferably 3 μm or more. The fiber diameter is preferably 80 μm or less, more preferably 50 μm or less, even more preferably 30 μm or less, particularly preferably 10 μm or less, and especially preferably 7 μm or less. When the fiber diameter of the fibrous cellulose is within the above range, the resin pressure can be sufficiently reduced, which is preferable because the appearance of the laminate tends to be good. In this specification, the fiber diameter of cellulose is a value measured by the same method as for measuring the fiber length.

[0030] The cellulose used in this embodiment is contained in an amount of 20 parts by mass or more, preferably 25 to 280 parts by mass, more preferably 27 to 240 parts by mass, even more preferably 30 to 200 parts by mass, and even more preferably 35 to 150 parts by mass, per 100 parts by mass of the thermoplastic resin (a). When the content of cellulose (c) contained in the layer (A) containing the thermoplastic resin (a) is 1 part by mass or more, this is preferable because it improves adhesion to the PVA-based resin layer. When the content of cellulose (c) contained in the layer (A) containing the thermoplastic resin (a) is 280 parts by mass or less, this is preferable because it improves the appearance of the laminate. When the thermoplastic resin composition used in this embodiment contains hemicellulose and / or lignin, the masses of the hemicellulose and lignin are included in the cellulose (c) content, since the hemicellulose and lignin are substances that constitute lignocellulose.

[0031] <Other Components (d)> Layer A (the layer having the thermoplastic resin (a)) used in the present embodiment may contain other components (d) besides the polysaccharide (c) (including when the polysaccharide (c) is cellulose), as long as the effects of the present embodiment are not impaired. Examples of such other components (d) include inorganic fillers such as talc and calcium carbonate (precipitated calcium carbonate). The content thereof is usually 20 parts by mass or less, preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and particularly preferably 3 parts by mass or less, relative to 100 parts by mass of the thermoplastic resin composition constituting the thermoplastic resin (a).

[0032] To obtain a thermoplastic resin composition containing a predetermined amount of polysaccharide (c) (including cases where the polysaccharide (c) is cellulose) constituting layer A used in the present embodiment, for example, a predetermined amount of the polysaccharide (c) is added to a thermoplastic resin composition containing materials other than the polysaccharide (c), and various known methods, such as mixing the components using an apparatus such as a Plastomill, a Henschel mixer, a V-blender, a ribbon blender, a tumbler, a blender, or a kneader-ruder, or melt-kneading using an apparatus such as a single-screw extruder, a twin-screw extruder, a kneader, or a Banbury mixer, can be used. Among these, melt-kneading is preferred because it allows for uniform mixing.

[0033] <PVA-based resin (b)> Layer (B) (hereinafter sometimes referred to as "layer B" or "B") is preferably used as a gas barrier layer in the laminate of this embodiment and preferably provides the gas barrier properties of the laminate of this embodiment. The layer B is directly laminated (abuts) on at least one surface of the layer A (the layer containing the thermoplastic resin (a)) described above.

[0034] The layer B used in the present embodiment is a layer containing the PVA-based resin (b) as a main component, and preferably contains 70% by mass or more of the PVA-based resin (b), more preferably 80% by mass or more, and even more preferably 90% by mass or more. The upper limit of the content is 100% by mass. When the content is 70% by mass or more, sufficient gas barrier properties tend to be obtained.

[0035] The PVA-based resin (b) used in the present embodiment is a resin mainly composed of vinyl alcohol structural units, which is obtained by saponifying a polyvinyl ester-based resin obtained by polymerizing a vinyl ester-based monomer, and is composed of vinyl alcohol structural units and vinyl ester structural units in amounts corresponding to the degree of saponification.

[0036] Examples of the vinyl ester monomer include vinyl formate, vinyl acetate, vinyl propionate, vinyl valerate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caprate, vinyl laurate, vinyl stearate, vinyl benzoate, and vinyl versatate, with vinyl acetate being economically preferred.

[0037] The average degree of polymerization of the PVA-based resin (b) used in the present embodiment (measured in accordance with JIS K6726-1994) is preferably 200 to 1,800, more preferably 300 to 1,500, and even more preferably 300 to 1,000.

[0038] When the average degree of polymerization is 200 or more, the mechanical strength of layer B tends to be sufficient. When the average degree of polymerization is 1,800 or less, a decrease in fluidity can be suppressed when layer B is formed by hot melt molding, and moldability tends to be improved. Furthermore, abnormal shear heating during molding can be suppressed, and thermal decomposition of PVA-based resin (b) becomes difficult.

[0039] The saponification degree of the PVA-based resin (b) used in the present embodiment (measured in accordance with JIS K6726-1994) is preferably 70 to 100 mol%, more preferably 90 to 99.9 mol%, and even more preferably 98 to 99.9 mol%. When the saponification degree is 70 mol% or more, the gas barrier property tends to be improved.

[0040] In this embodiment, the PVA-based resin (b) may be a resin obtained by copolymerizing various monomers during the production of a polyvinyl ester-based resin and then saponifying the copolymer, or a modified PVA-based resin obtained by post-modifying an unmodified PVA to introduce various functional groups.

[0041] Examples of monomers used for copolymerization with vinyl ester monomers include olefins such as ethylene, propylene, isobutylene, α-octene, α-dodecene, and α-octadecene; hydroxyl group-containing α-olefins such as 3-buten-1-ol, 4-penten-1-ol, 5-hexen-1-ol, and 3,4-dihydroxy-1-butene, and derivatives thereof such as acylated products; unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, maleic anhydride, and itaconic acid, salts thereof, monoesters thereof, and dialkyl esters thereof; nitriles such as acrylonitrile and methacrylonitrile; and diacetone acrylate. olefin sulfonic acids such as ethylene sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid or salts thereof; alkyl vinyl ethers, dimethyl allyl vinyl ketone, N-vinyl pyrrolidone, vinyl chloride, vinyl ethylene carbonate, 2,2-dialkyl-4-vinyl-1,3-dioxolane, glycerin monoallyl ether, 3,4-diacetoxy-1-butene or other vinyl compounds; substituted vinyl acetates such as isopropenyl acetate and 1-methoxyvinyl acetate; vinylidene chloride, 1,4-diacetoxy-2-butene, vinylene carbonate, and the like.

[0042] Examples of modified PVA-based resins into which functional groups have been introduced by post-modification include those having acetoacetyl groups by reaction with diketene, those having polyalkylene oxide groups by reaction with ethylene oxide, those having hydroxyalkyl groups by reaction with an epoxy compound, and those obtained by reacting PVA with an aldehyde compound having various functional groups.

[0043] The content of modified species in the modified PVA-based resin, i.e., structural units derived from various monomers in the copolymer or functional groups introduced by post-modification, is preferably 1 to 40 mol %, more preferably 2 to 35 mol %, although it is difficult to generalize because the properties vary greatly depending on the modified species.

[0044] Among these various modified PVA-based resins, in the present embodiment, a PVA-based resin having a structural unit having a 1,2-diol structure in a side chain, represented by the following general formula (1) (hereinafter, may be referred to as a "1,2-diol structural unit"), is preferably used because it facilitates melt molding in the method for producing a multilayer laminate described below.

[0045]

[0046] R in the 1,2-diol structural unit represented by general formula (1) １ ~R ４ each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms.

[0047] Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a tert-butyl group. The alkyl group may have a functional group such as a halogen group, a hydroxyl group, an ester group, a carboxylic acid group, or a sulfonic acid group, as necessary.

[0048] Furthermore, X in the 1,2-diol structural unit represented by general formula (1) represents a single bond or a bonding chain. Examples of such bonding chains include hydrocarbons such as linear or branched alkylene groups having 1 to 6 carbon atoms, linear or branched alkenylene groups having 1 to 6 carbon atoms, linear or branched alkynylene groups having 1 to 6 carbon atoms, phenylene groups, and naphthylene groups (these hydrocarbons may be substituted with halogens such as fluorine, chlorine, and bromine), as well as -O-, -(CH ２ O) ｔ -, -(OCH ２ ) ｔ -, -(CH ２ O) ｔ CH ２ -, -CO-, -COCO-, -CO(CH ２ ) ｔ CO-, -CO(C ６ H ４ )CO-, -S-, -CS-, -SO-, -SO2-, -NR-, -CONR-, -NRCO-, -CSNR-, -NRCS-, -NRNR-, -HPO ４ -, -Si(OR) ２-, -OSi(OR) ２ -, -OSi(OR) ２ O-, -Ti (OR) ２ -, -OTi(OR) ２ -, -OTi(OR) ２ Examples include O-, -Al(OR)-, -OAl(OR)-, -OAl(OR)O-, etc. (each R is independently an arbitrary substituent and represents a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms, and t represents an integer of 1 to 5. Among these, from the viewpoint of stability during production or use, the bonding chain is preferably a linear or branched alkylene group having 1 to 6 carbon atoms, particularly a methylene group, or -CHOCH ２ - is preferred.

[0049] X is most preferably a single bond in terms of thermal stability and stability at high temperatures and under acidic conditions.

[0050] Among the 1,2-diol structural units represented by general formula (1), R １ ~R ４ A structural unit represented by the following general formula (1') in which all of are hydrogen atoms and X is a single bond is most preferred.

[0051]

[0052] Examples of methods for producing such PVA-based resins having 1,2-diol structural units in their side chains include the methods described in paragraphs

[0026] to

[0034] of JP-A-2015-143356.

[0053] The content of the 1,2-diol structural unit in the side chain of the PVA-based resin is preferably 1 to 20 mol%, more preferably 2 to 10 mol%, and even more preferably 3 to 8 mol%. When the content is 1 mol% or more, the effect of the 1,2-diol structure in the side chain is sufficiently obtained, and when the content is 20 mol% or less, a decrease in gas barrier property at high humidity tends to be suppressed.

[0054] The content of 1,2-diol structural units in the PVA resin is the same as that of the PVA resin completely saponified. １The content can be determined from a H-NMR spectrum (solvent: DMSO-d6, internal standard: tetramethylsilane). Specifically, the content can be calculated from the peak areas derived from hydroxyl group protons, methine protons, and methylene protons in the 1,2-diol structural unit, methylene protons in the main chain, and protons of hydroxyl groups linked to the main chain.

[0055] The PVA-based resin (b) used in the present embodiment may be a single type or a mixture of two or more types. When the PVA-based resin (b) is a mixture of two or more types, the PVA-based resin may be a combination of the above-mentioned unmodified PVAs, an unmodified PVA and a PVA-based resin having the structural unit represented by general formula (1), a combination of PVA-based resins having the structural unit represented by general formula (1) but differing in saponification degree, polymerization degree, modification degree, etc., an unmodified PVA, or a PVA-based resin having the structural unit represented by general formula (1) and another modified PVA-based resin, etc.

[0056] Layer B (layer containing PVA-based resin (b)) used in the present embodiment may contain, in addition to PVA-based resin (b), a heat stabilizer, an antioxidant, an ultraviolet absorber, a crystal nucleating agent, an antistatic agent, a flame retardant, a plasticizer, a lubricant, a filler, a lubricant, or a crystal nucleating agent.

[0057] The oxygen permeability of the layer B in this embodiment is, for example, 200 cc / m under an environment of 23°C and 50% RH. ２ ・day・atm or less, 100cc / m ２ ・day・atm or less, 50cc / m ２ ・day・atm or less, 10cc / m ２ The lower limit of the oxygen permeability is usually 0 cc / m ２ The oxygen permeability of Layer B within the above range is preferable because it provides good barrier properties. The oxygen permeability can be determined using an oxygen permeability measuring device (for example, OX-TRAN2 / 20, manufactured by MOCON Corporation, USA).

[0058] <Multilayer Laminate> In the multilayer laminate of this embodiment, Layer A (a layer containing a thermoplastic resin (a)) and Layer B (a layer containing a PVA-based resin (b)) are in contact with each other without the use of an adhesive. The layer structure of the multilayer laminate of this embodiment is not limited to Layer A / Layer B, and any combination is possible, such as Layer A / Layer B / Layer A, Layer A / Layer B / Layer A / Layer B / Layer A, etc. The " / " symbol indicates that the layers before and after it are in contact with each other. A layer A / Layer B / Layer A structure is particularly preferable because it improves the appearance of the laminate. Furthermore, for the purpose of imparting other functions, the multilayer laminate of this embodiment may contain other substrate layers whose main component is a thermoplastic resin other than the thermoplastic resins specified for Layer A and Layer B of this embodiment. The total number of layers in the multilayer laminate of this embodiment is typically 2 to 15, and preferably 3 to 10. In the above-described layer structure, it is not necessary to interpose an adhesive resin layer containing an adhesive resin between Layer A and Layer B. However, an adhesive resin layer containing an adhesive resin may be interposed between Layer A or Layer B and another layer, if necessary. Also, Layer A may be positioned as an adhesive resin layer between Layer B and another layer (for example, a heat seal layer). That is, the resin composition constituting Layer A can be used as an adhesive.

[0059] The layer A (layer containing thermoplastic resin (a)) and layer B (layer containing PVA-based resin (b)) can be laminated by a known method. Examples of such methods include melt-extrusion laminating the PVA-based resin (b) onto a film, sheet, or the like that is the layer A; co-extruding the thermoplastic resin (a) and the PVA-based resin (b); applying a solution of the PVA-based resin (b) onto the layer A and then removing the solvent; and integrally molding the layer A and layer B by two-color molding. Among these, in consideration of cost and environmental considerations, it is preferable to produce the laminate by including a step of melt-molding the layer B, and specifically, the co-extrusion method is preferred.

[0060] The multilayer laminate of this embodiment may be subjected to a (heat) stretching treatment as needed. The stretching treatment may be either uniaxial stretching or biaxial stretching, and in the case of biaxial stretching, it may be simultaneous stretching or sequential stretching. Furthermore, as the stretching method, a method with a high stretch ratio, such as roll stretching, tenter stretching, tubular stretching, stretch-blow method, or vacuum / pressure forming, may also be used. The stretching temperature is a temperature near the melting point of the multilayer laminate, and is usually selected from the range of 40 to 170°C, preferably about 60 to 160°C. If the stretching temperature is too low, stretchability tends to be poor, and if it is too high, it tends to be difficult to maintain a stable stretched state.

[0061] The multilayer laminate of the present embodiment after stretching may be heat-set to impart dimensional stability. Heat-setting can be performed by known means, for example, by heat-treating the multilayer laminate of the present embodiment after stretching at typically 80 to 180°C, preferably 100 to 165°C, for typically 2 to 600 seconds while maintaining tension.

[0062] When the stretched multilayer laminate of the present embodiment is to be used as a shrink film, the heat-shrinkability can be imparted by, for example, applying cold air to the stretched multilayer laminate of the present embodiment to cool and fix it, without carrying out the heat-setting process described above.

[0063] The thickness of the multilayer laminate (including stretched laminates) of this embodiment, as well as the thickness (αA) of Layer A (layer containing thermoplastic resin (a)) and the thickness (αB) of Layer B (layer containing PVA-based resin (b)) constituting the multilayer laminate, vary depending on the intended use, packaging form, required physical properties, etc., but are typically 10 to 5,000 μm, preferably 30 to 3,000 μm, and particularly preferably 50 to 2,000 μm. The thickness (αA) of Layer A (layer containing thermoplastic resin (a)) is typically 1 to 1,000 μm, preferably 5 to 800 μm, more preferably 10 to 700 μm, even more preferably 20 to 650 μm, and particularly preferably 25 to 600 μm. A thickness (αA) of Layer A containing thermoplastic resin (a) of 1 μm or more is preferred because it results in a film with sufficient strength, while a thickness of 1,000 μm or less is preferred because it results in a uniform film with little thickness unevenness. The thickness (αB) of the layer B (layer containing the PVA-based resin (b)) is usually 0.1 to 100 μm, preferably 0.5 to 50 μm, and particularly preferably 1 to 35 μm. The thickness (αB) of the PVA-based resin (B) layer is preferably 0.1 μm or more, since it exhibits high gas barrier properties without defects, and is preferably 100 μm or less, since it provides a uniform film with little thickness unevenness.

[0064] Furthermore, in this embodiment, the ratio (αA / αB) of the thickness (αA) of layer A (layer having thermoplastic resin (a)) to the thickness (αB) of layer B (layer having PVA-based resin (b)), expressed as the ratio between the thickest layers when there are multiple layers, is preferably 0.01 to 1000, more preferably 0.01 to 500, even more preferably 0.1 to 100, particularly preferably 0.7 to 80, especially preferably 1 to 50, still more preferably 1.5 to 30, and most preferably 2 to 10. Setting the ratio within the above range is preferred because excellent adhesion, flexibility, and gas barrier properties are achieved.

[0065] The gas barrier properties of the multilayer laminate of the present embodiment were measured by measuring the oxygen permeability (cc / m) under conditions of 23°C and 50% RH using an oxygen permeability measuring device (OX-TRAN2 / 20, manufactured by MOCON Corporation, USA). ２ The oxygen permeability when measured is 1 cc / m ２ ・10cc / m for more than a day２ - It is preferable that it is less than 0.1 cc / m ２ ・1cc / m for more than a day ２ It is more preferable that the concentration is less than 0.1 cc / m ２ It is particularly preferable that the period is less than 1 day.

[0066] The multilayer laminate obtained in this manner is highly biodegradable, so even if it is disposed of as is in the compost, it will not place a significant burden on the global environment. Furthermore, because it has excellent gas barrier properties, it can be suitably used, for example, as a coffee capsule (a coffee bean container for a capsule-type coffee maker), shrink film, or other container for food or drink. Furthermore, the multilayer laminate of this embodiment does not require an adhesive layer, so it can also be made into a monomaterial.

[0067] <Adhesive> Next, embodiment (3) will be described. Embodiment (3) is an adhesive containing 20 to 280 parts by mass of cellulose per 100 parts by mass of thermoplastic resin (a).

[0068] In the adhesive of embodiment (3), the thermoplastic resin (a) and cellulose may be those described for the multilayer structure, and the preferred components and amounts thereof are the same as those described for the multilayer structure, and the effects thereof are also the same. Furthermore, another component (d) may also be added, and the amount thereof is the same as that described for the multilayer structure.

[0069] The adhesive of embodiment (3) exhibits excellent adhesion between various materials, particularly when used between layers of resin films. Specifically, by applying it between layers of thermoplastic resin films such as polypropylene (PP), polyethylene (PE), and polyethylene terephthalate (PET), a multilayer laminate can be obtained that achieves excellent adhesion and interlayer peel strength. As mentioned above, cellulose (c) has many hydroxyl groups, which allows for strong interaction with the PVA-based resin (b), making it suitable for bonding between layers of resin films made of different materials.

[0070] The adhesive of embodiment (3) may be applied to the bonded surface of a resin film, and another resin film may be laminated thereon, followed by a heating process and a pressure-bonding process to bond the resin films together. Alternatively, the resin films may be bonded using a melt-extrusion lamination method or a co-extrusion method. The adhesive may also be used as an adhesive layer (intermediate layer) in the production of a laminated film (multilayer laminate). In other words, the adhesive of this embodiment can ensure a predetermined layer thickness when bonding resin films together, and thus can form a uniform adhesive layer with little thickness variation.

[0071] The adhesive of embodiment (3) can exhibit high adhesiveness between layers of resin films, and therefore can be preferably used in fields such as food packaging materials and industrial laminate products. In addition, the adhesive does not cause excessive thermal effects on the resin films during heating and pressure bonding.

[0072] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples as long as it does not depart from the gist of the invention. In the examples, "parts" and "%" are by mass unless otherwise specified.

[0073] First, the following materials were prepared as materials to be used for each layer of the multilayer laminate: [Layer A (Layer containing thermoplastic resin (a))] The following was used as the thermoplastic resin (a). PBSA: "BiOPBS (trademark) (FZ71PM)" manufactured by PTT MCC Biochem, melt flow rate (MFR) 22 g / 10 min (190°C, 2.16 kg), melting point 115°C. PBS: "BiOPBS (trademark) (FD92PM)" manufactured by PTT MCC Biochem, melt flow rate (MFR) 4 g / 10 min (190°C, 2.16 kg), melting point 84°C. PCL: "Capa (trademark) 6500" manufactured by Ingevity, melt flow rate (MFR) 7 g / 10 min (2.16 kg, 160°C), melting point 59°C. PLA-PBAT blend: "Ecovio (trademark)" manufactured by BASF. F2224", melt flow rate (MFR) 3 g / 10 min (190°C, 2.16 kg), melting point 115,150°C. Polypropylene (PP): Japan Polypropylene Corporation "Novatec (trademark) MG05ES", melt flow rate (MFR) 18 g / 10 min (190°C, 2.16 kg), melting point 159°C. Polyethylene (PE): Japan Polypropylene Corporation "Novatec (trademark) HJ360", melt flow rate (MFR) 5 g / 10 min (190°C, 2.16 kg), melting point 130°C. The following compounding agents were also used. (Cellulose (polysaccharide (c)) Cellulose: "ARBOCEL (trademark) UFC100" manufactured by Rettenmeyer, average fiber length 18.7 μm, average fiber diameter 6.2 μm, cellulose purity 99% Wood flour: "ARBOCEL (trademark) CW630PU" manufactured by Rettenmeyer, average fiber length 28 μm, average fiber diameter 7.8 μm, cellulose purity 40% Starch: "TAPIOPLAST" manufactured by SMS Corporation (Other than cellulose (polysaccharide (c))) Talc: "SG-95" manufactured by Nippon Talc Co., Ltd., average particle size: 2.1 μm Calcium carbonate: manufactured by Kishida Chemical Co., Ltd.

[0074] [Layer B (Layer Containing PVA-Based Resin (b))] The following PVA-based resins were used as the PVA-based resin (b): 1,2-diol-modified PVA: manufactured by Mitsubishi Chemical Corporation, saponification degree 99.2 mol%, polymerization degree 450, 1,2-diol structural unit content 6 mol% Unmodified PVA: manufactured by Mitsubishi Chemical Corporation, saponification degree 73.0 mol%, polymerization degree 550 Ethylene-modified PVA (EVOH): manufactured by Mitsubishi Chemical Corporation, ethylene structural unit content 32 mol%, saponification degree 99.6 mol%, melt flow rate (MFR) 12 g / 10 min (210°C, load 2160 g)

[0075] [Preparation of pellets containing thermoplastic resin (a) and polysaccharide (c) (1)] A resin composition containing thermoplastic resin (a) and polysaccharide (c) in the blending ratios shown in Table 1 was prepared, and pellets were prepared under the following molding conditions. [Molding conditions] Twin-screw extruder: KZW15-45 / 60MG, manufactured by Technovel Co., Ltd. Screw rotation speed: 200 rpm Vent: fully closed Temperature conditions When thermoplastic resin (a) is PBSA, PBS, or PCL: C1 / C2 / C3 / C4 / C5 / C6 / C7 / C8 / D1 / D2 = 80°C / 120°C / 130°C / 140°C / 140°C / 140°C / 140°C / 140°C / 140°C When thermoplastic resin (a) is a PLA-PBAT blend: C1 / C2 / C3 / C4 / C5 / C6 / C7 / C8 / D1 / D2=140℃ / 160℃ / 160℃ / 160℃ / 160℃ / 160℃ / 160℃ / 160℃ / 160℃ / 160℃

[0076] [Preparation of Multilayer Laminate] Using the prepared materials, a multilayer laminate having three layers (A / B / A) was prepared as follows. Using PVA-based resin (b), a two-type three-layer multilayer film-forming device equipped with a 30 cm wide T-die (twin-screw extruder: KZW15-45 / 60MG, single-screw extruder: SZW20GT-24MG-STD, manufactured by Technovel Co., Ltd.) was used. A two-type three-layer structure of layer A (layer having thermoplastic resin (a)) / layer B (layer having PVA-based resin (b)) / layer A (layer having thermoplastic resin (a)) was prepared. The thickness of the obtained laminate was 330 μm, the thickness of each layer was 150 μm (αA:A layer) / 30 μm (αB:B layer) / 150 μm (αA:A layer), and the width of the obtained laminate was 2.5 cm. The set temperatures of each extruder and roll at this time were as follows. Set temperatures (C1 to C4: cylinders, H: head, J: joint, FD1, 2: front die, D1 to 3: dies.) When thermoplastic resin (a) is PBSA, PBS, PCL: C1 / C2 / C3 / C4 / H / J = 140 / 150 / 150 / 150 / 150 / 150°C When thermoplastic resin (a) is PLA-PBAT blend: C1 / C2 / C3 / C4 / H / J = 150 / 160 / 160 / 160 / 160 / 160°C When thermoplastic resin (a) is PP: C1 / C2 / C3 / C4 / H / J = 170 / 180 / 180 / 180 / 180 / 180°C PVA-based resin (b): C1 / C2 / C3 / C4 / H / J = 180 / 200 / 210 / 210 / 210 / 210°C Roll: 60°C Die: FD1 / FD2 / D1 / D2 / D3 = 195 / 195 / 195 / 195 / 195°C

[0077] The multilayer laminate thus obtained was evaluated for adhesiveness, gas barrier properties and appearance as follows, and the results are shown in Table 1 below.

[0078] [Adhesion] The multilayer laminate was cut into strips with a width of 15 mm, and the adhesion at the interface between Layer A and Layer B was measured using a 50 N load cell of a tensile tester "AG-IS 5kN" (manufactured by Shimadzu Corporation). The test speed was set to 100 mm / min, and the average value of five tests was taken as the adhesion value. The measurement was carried out in an environment of 23°C / 50% RH. If the adhesion could not be measured accurately because the thickness of the laminate was uneven, or if it could not be measured because the laminate was made of a single resin, the evaluation result was "-".

[0079] [Gas Barrier Properties] The oxygen permeability (cc / m) of the multilayer laminate was measured at 23°C and 50% RH in accordance with JIS K 7126-1 using an oxygen permeability measuring device (OX-TRAN2 / 20, manufactured by MOCON Corporation, USA). ２ ·day) was measured.

[0080] [Appearance] The appearance of the multilayer laminate was visually observed and evaluated according to the following criteria: A+: There were no areas in the interior or at the edges where the thickness of each layer was uneven, and the surface was highly white. A: There were no areas in the interior or at the edges where the thickness of each layer was uneven, but the surface was yellowed. B: There were no areas in the interior or at the edges where the thickness of each layer was uneven, but the surface was burnt brown. C: There were areas in the interior or at the edges where the thickness of each layer was uneven, and the surface was burnt brown.

[0081]

[0082] As shown in Table 1 above, Examples 1 to 13 were excellent in adhesion, gas barrier properties, and appearance evaluation. In contrast, Comparative Example 4, in which no compounding agent was used in Layer A, and Comparative Examples 1 and 5 to 8, in which cellulose was not used as a compounding agent, were poor in adhesion and gas barrier properties. Furthermore, Comparative Example 9, in which Layer B was not provided, was poor in gas barrier properties. Furthermore, Comparative Example 2, in which 11 parts by mass of cellulose was used as a compounding agent in Layer A, was poor in adhesion and gas barrier properties, and Comparative Example 3, in which 300 parts by mass of cellulose was used as a compounding agent in Layer A, was poor in gas barrier properties and appearance.

[0083] [Preparation of Pellets Having Thermoplastic Resin (a) and Cellulose (2)] A resin composition containing PP as the thermoplastic resin (a) and a polysaccharide (c) according to the blending ratios shown in Table 2 was prepared, and pellets were prepared under the following molding conditions. [Molding Conditions] Twin-screw extruder: KZW15-45 / 60MG, manufactured by Technovel Co., Ltd. Screw rotation speed: 200 rpm Vent: fully closed Temperature conditions C1 / C2 / C3 / C4 / C5 / C6 / C7 / C8 / D1 / D2 = 150°C / 170°C / 180°C / 180°C / 180°C / 180°C / 180°C / 180°C / 180°C / 180°C Discharge rate: 1 kg / hour

[0084] [Preparation of Multilayer Laminate] Using the prepared materials, a multilayer laminate having three layers (A / B / A) was prepared as follows. Using PVA-based resin (b), a two-type three-layer multilayer film-forming device equipped with a 30 cm wide T-die (twin-screw extruder: KZW15-45 / 60MG, single-screw extruder: SZW20GT-24MG-STD, manufactured by Technovel Co., Ltd.) was used. A two-type three-layer structure of layer A (layer having thermoplastic resin (a)) / layer B (layer having PVA-based resin (b)) / layer A (layer having thermoplastic resin (a)) was prepared. The thickness of the obtained laminate was 330 μm, the thickness of each layer was 150 μm (αA:A layer) / 30 μm (αB:B layer) / 150 μm (αA:A layer), and the width of the obtained laminate was 2.5 cm. The set temperatures of each extruder and roll at this time were as follows. Set temperatures (C1 to C4: cylinders, H: head, J: joint, FD1, 2: front die, D1 to 3: dies.) C1 / C2 / C3 / C4 / H / J = 170 / 180 / 180 / 180 / 180 / 180°C PVA resin (b): C1 / C2 / C3 / C4 / H / J = 180 / 200 / 210 / 210 / 210 / 210°C Roll: 60°C Die: FD1 / FD2 / D1 / D2 / D3 = 195 / 195 / 195 / 195 / 195°C

[0085] The multilayer laminate thus obtained was evaluated for adhesiveness, gas barrier properties and appearance as described above, and the results are shown in Table 2 below.

[0086]

[0087] As shown in Table 2, Examples 14 and 15 were excellent in adhesiveness, appearance, and gas barrier properties. In contrast, Comparative Example 10, in which 300 parts by mass of cellulose was used as a compounding agent in Layer A, had no adhesiveness and a multilayer laminate could not be obtained. Furthermore, Comparative Example 11, in which no compounding agent was used in Layer A, was poor in adhesiveness and gas barrier properties.

[0088] Although the above examples show specific embodiments of the present invention, the examples are merely illustrative and should not be construed as limiting. Various modifications that are obvious to those skilled in the art are intended to fall within the scope of the present invention.

[0089] The multilayer laminate of the present embodiment can be used as a multilayer laminate excellent in adhesiveness and gas barrier properties.

Claims

1. A multilayer laminate comprising a layer (A) containing a thermoplastic resin (a) and a layer (B) containing a polyvinyl alcohol-based resin (b) in contact with each other, wherein the layer (A) contains 20 to 280 parts by mass of a polysaccharide (c) per 100 parts by mass of the thermoplastic resin (a), the content of polysaccharide (c) in the layer (A) is 25% by mass or more, and the ratio (αA / αB) of the thickness (αA) of the layer (A) to the thickness (αB) of the layer (B) is 0.7 to 1000.

2. The multi-layer laminate according to claim 1, wherein the polysaccharide (c) comprises cellulose.

3. A multilayer laminate in which a layer (A) containing a thermoplastic resin (a) and a layer (B) containing a polyvinyl alcohol-based resin (b) are in contact with each other, and the layer (A) contains 20 to 280 parts by mass of cellulose per 100 parts by mass of the thermoplastic resin (a).

4. The multilayer laminate according to claim 3, wherein the ratio (αA / αB) of the thickness (αA) of said layer (A) to the thickness (αB) of said layer (B) is 0.01 to 1000.

5. The multilayer laminate according to claim 1 or 3, which comprises at least two layers (A), each of which abuts on both sides of layer (B).

6. The multilayer laminate according to claim 1 or 3, wherein the melting point of said thermoplastic resin (a) is 220°C or lower.

7. The multilayer laminate according to claim 1 or 3, wherein the thermoplastic resin (a) comprises a biodegradable resin.

8. The multilayer laminate according to claim 1 or 3, wherein the thickness (αB) of the layer (B) is 0.1 to 100 μm.

9. The multilayer laminate according to claim 1 or 3, wherein the thickness (αA) of the layer (A) is 1 to 1000 μm.

10. The multilayer laminate according to claim 1 or 3, wherein the thickness (αB) of the layer (B) is 0.1 to 100 μm.

11. The multilayer laminate according to claim 1 or 3, wherein the polysaccharide (c) or the cellulose has a fibrous structure and the fiber length is 5 μm or more and 150 μm or less.

12. A coffee capsule comprising the multilayer laminate according to claim 1 or 3.

13. An adhesive containing 20 to 280 parts by mass of cellulose per 100 parts by mass of thermoplastic resin (a).

14. The adhesive according to claim 13, wherein the cellulose is fibrous and has a fiber length of 5 μm or more and 150 μm or less.

15. The adhesive according to claim 13 or 14, wherein the thermoplastic resin (a) comprises a biodegradable resin.

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