Laminate

Abstract

To provide a laminate that offers excellent fragrance retention regardless of the type of fragrance and reduces residual solvents. [Solution] A laminate having a sealant layer containing a hydroxyl group-containing polyester resin with a glass transition temperature of 40 to 120°C, and a sealant layer.

Description

[Technical Field]

[0001] The present invention relates to laminates used for packaging alcoholic beverages, flavored beverages, coffee grounds, fragrance powders, fabric softeners, liquid detergents, shampoos, conditioners, perfumes, and other beverages and foods containing fragrance components, as well as detergents and cosmetics. [Background technology]

[0002] For packaging beverages, foods, detergents, and cosmetics containing aromatic components such as alcoholic beverages, flavored beverages, coffee grounds, fragrance powders, fabric softeners, liquid detergents, shampoos, conditioners, and perfumes, films with high fragrance retention properties (such as films laminated with highly barrier-type polyvinyl alcohol resin or ethylene-vinyl alcohol copolymer resin) have been used to prevent the fragrance from escaping the container. While the tendency of such films to prevent the permeation of fragrance components and maintain their scent seems related to their gas barrier properties, these tendencies do not always coincide in reality.

[0003] Furthermore, packaging materials that retain fragrance are known to consist of a resin film with a metal layer or a metal oxide layer. Furthermore, if items containing a large amount of aromatic compounds are stored in containers with insufficient fragrance retention, even if they are airtight, the aromatic compounds will eventually escape from the container over time. As a result, when aromatic compounds escape from products in a store with a large number of items on display, even if only a small amount of aromatic compounds permeates from one product, the total amount of leakage is large, and consequently, the entire sales floor becomes filled with fragrance.

[0004] Patent documents 1 and 2 describe polyester polyols that have low oxygen permeability, but whose permeability to fragrance components is unknown. Patent Document 3 describes a laminate for liquid packaging that has low oxygen permeability and excellent aroma retention, achieved by combining a specific heat-seal layer, a coating layer, and an adhesive layer. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Patent No. 7207617 [Patent Document 2] Patent No. 7529179 [Patent Document 3] International Publication No. 2024 / 135510 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] In recent years, there has been a demand for laminates that have high fragrance retention regardless of the type of fragrance, and that reduce the amount of residual solvent. Normally, when a composition in the form of a solution is applied to form a coating layer, a very small amount of residual solvent remains in the layer. If the coating layer is located in the middle of a laminate, the other layers function as if they were shielding layers, reducing the amount of residual solvent that escapes the laminate. However, in some cases, it is necessary to further reduce the amount of residual solvent that escapes the laminate. This invention has been made in view of the above circumstances, and aims to provide a laminate that exhibits excellent fragrance retention regardless of the type of fragrance, and has a reduced amount of residual solvent. [Means for solving the problem]

[0007] The inventors of the present invention have conducted extensive research to solve the above problems and have found that the above problems can be solved by using the laminate shown below, thereby completing the present invention. 1. A laminate having a sealant layer containing a hydroxyl group-containing polyester resin with a glass transition temperature of 40 to 120°C, and a sealant layer. 2. The laminate according to claim 1, comprising, in order, a base layer, a printed layer, an adhesive layer, a fragrance-retaining layer containing a hydroxyl group-containing polyester resin having a glass transition temperature of 40 to 120°C, and a sealant layer. 3. The laminate according to claim 1 or 2, wherein the fragrance-retaining layer is formed from a hydroxyl group-containing polyester resin having a glass transition temperature of 40 to 120°C and a polyisocyanate curing agent. 4. The laminate according to 3, wherein the polyisocyanate curing agent is a polyisocyanate curing agent having a functionality of 3 or more. 5. The laminate according to any one of 1 to 4, wherein the coating amount after drying of the fragrance-retaining layer is 0.15 to 1.0 g / m 2 2. 6. A laminate for a packaging film having a fragrance-retaining layer containing a hydroxyl group-containing polyester resin having a glass transition temperature of 40 to 120°C on a sealant layer.

Advantages of the Invention

[0008] According to the present invention, a laminate that exhibits excellent fragrance-retaining properties and reduces residual solvents from the laminate can be obtained.

Brief Description of the Drawings

[0009] [Figure 1] It is a diagram showing a laminate having a fragrance-retaining layer produced in an example. A is a diagram showing laminates produced in Examples 1 to 13 and Comparative Examples 1 to 2, and B is a diagram showing laminates produced in Comparative Examples 3 to 13.

Modes for Carrying Out the Invention

[0010] The present invention is based on a laminate having a fragrance-retaining layer containing a hydroxyl group-containing polyester resin having a glass transition temperature of 4 to 120°C on a sealant layer, and a sealant layer. Specifically, a laminate having a base material layer, a printing layer, an adhesive layer, a fragrance-retaining layer containing a hydroxyl group-containing polyester resin having a glass transition temperature of 40 to 120°C, and a sealant layer in this order can be exemplified. The fragrance-retaining property according to the present invention is different from so-called gas barrier properties. The fragrance-retaining property is a property of preventing the leakage of fragrance components outside the container without allowing the fragrance components to permeate, and the gas barrier property is usually a property of preventing the intrusion from outside the container and the volatilization outside the container for carbon dioxide, oxygen, and in some cases water vapor. Since the gas components preventing permeation and the like are different between the fragrance-retaining property and the gas barrier property, a layer having simply gas barrier properties cannot be said to be a layer having fragrance-retaining properties. The present invention will be described below.

[0011] <Base material layer> As the optionally provided base material layer used in the laminate of the present invention, known ones may be used. As a packaging material for foods, daily necessities, etc. having a fragrance component, it may be used as a layer located on the outermost layer side of the packaging container in a state where these are packaged. As the base material layer, polyolefins such as polyethylene, polypropylene, ethylene-propylene copolymer, polyesters such as polyethylene terephthalate, unstretched films such as polyamide, uniaxially stretched films and biaxially stretched films such as polyolefins such as polyethylene and polypropylene, paper, woven fabrics or non-woven fabrics within the range where a printing layer can be formed, can be selected and used. Also, a plurality of these layers laminated may be used as the base material layer, and corona discharge treatment or primer treatment may be performed on the surface of the base material layer on the printing layer side to improve adhesion to the printing layer. In the present invention, when an ethylene-based heat seal layer is used as the sealant layer, it can be excluded from the aspect of a laminate using a stretched polyethylene film as the base material layer. Also, when the sealant layer has a function as a base material layer, a laminate without a base material layer can be used as a packaging container.

[0012] <Printing layer> The printing layer is an optionally provided layer, which is formed by printing a printing ink composition containing a pigment, a binder resin and a solvent, and drying and / or curing, and is a layer having a pigment and a binder resin. This printing ink composition is not limited as long as the effects of the present invention can be exhibited, but it is preferable to use a printing ink composition for laminate for flexible packaging. For example, when a packaging container is made using the laminate of the present invention in which the printing layer is provided on the base material layer, this printing layer becomes a layer that can be visually observed from the outer surface of the packaging container through the base material layer. Note that the printing layer may have a whole surface or a partial surface composed of one layer or two or more layers. Even if the printing layer is not formed on the entire surface of the base material layer, it is possible to visually observe the adhesive layer directly from the base material layer side.

[0013] (Pigment) As the above-mentioned pigments, for example, various inorganic pigments, organic pigments, or extender pigments commonly used in printing inks can be used. As the inorganic pigments mentioned above, colored pigments such as titanium dioxide, red iron oxide, antimony red, cadmium yellow, cobalt blue, Prussian blue, ultramarine, carbon black, and graphite can be used. Examples of the above-mentioned organic pigments include soluble azo pigments, insoluble azo pigments, azo lake pigments, condensed azo pigments, copper phthalocyanine pigments, and condensed polycyclic pigments. Examples of extender pigments include silica particles, calcium carbonate, kaolin, clay, barium sulfate, aluminum hydroxide, and talc. Among these, titanium dioxide is preferred as the inorganic pigment. The content of these pigments in the ink composition is typically around 1 to 50% by mass. Furthermore, a pigment dispersant may be used in combination. Examples of such pigment dispersants include polyester-based pigment dispersants that can be used in gravure printing ink compositions containing organic solvents. Specifically, examples include Azisper PB821, PB822, PB824, PB881 (Ajinomoto Fine Techno Co., Ltd.), Solspers 24000, 56000 (Nippon Lubrizol Co., Ltd.), and among these, basic group-containing polyester-based polymer dispersants can be preferably used. When including a pigment dispersant, the amount is usually preferably 1 to 200 parts by mass, and more preferably 1 to 60 parts by mass, per 100 parts by mass of the total pigment.

[0014] (Binder resin) The binder resin in the printed layer preferably contains amino groups and hydroxyl groups to ensure excellent adhesion to the substrate layer. The amine value is preferably 1.00 to 13.00 mgKOH / g, and the hydroxyl value is preferably 0.50 to 12.00 mgKOH / g. A hydroxyl group-containing polyurethane resin with amino groups at its ends is preferred as such a binder resin. From an environmental perspective, it is preferable that the polyurethane resin be a biomass polyurethane resin. Furthermore, one of the following may be used as the binder resin: a vinyl chloride / vinyl acetate copolymer resin having hydroxyl groups, a vinyl chloride / acrylic copolymer resin having hydroxyl groups, or a cellulose resin. The above amine value refers to the amine value per gram of solid content, measured using a 0.1N hydrochloric acid aqueous solution by potentiometric titration (for example, COMTITE (AUTO TITRATOR COM-900, BURET B-900, TITSTATION K-900), manufactured by Hiranuma Sangyo Co., Ltd.), and then converted to the equivalent amount of potassium hydroxide. The printing ink composition for forming the printed layer in the present invention may contain one or more agents selected from adhesion enhancers and blocking inhibitors, as long as they do not degrade the performance targeted by the present invention.

[0015] (Adhesion enhancer) As adhesion enhancers, rosin and its derivatives, chlorinated polypropylene, dammar resin, etc., can be used. (Blocking prevention agent) As anti-blocking agents, silica particles, polyethylene wax, fatty acid amides, etc., can be used.

[0016] (solvent) (Organic solvents) Among the solvents used in the above-mentioned printing ink composition, various organic solvents can be used, such as ketone-based organic solvents like acetone, methyl ethyl ketone, and methyl isobutyl ketone; ester-based organic solvents like methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, and isobutyl acetate; alcohol-based organic solvents like methanol, ethanol, n-propanol, isopropanol, and butanol; and hydrocarbon-based solvents like toluene and methylcyclohexane. From an environmental perspective, it is preferable to use a mixed solvent of ester-based organic solvents, alcohol-based organic solvents, and ketone-based organic solvents, or a mixed solvent of ester-based organic solvents and alcohol-based organic solvents that are more environmentally friendly. From a monosolvent perspective, it is even more preferable not to use alcohol. (water) The solvent used in the above-mentioned printing ink composition preferably contains water to mitigate printing defects caused by static electricity, prevent plate fogging, and improve cell reproducibility. When water is included, the amount of water in the printing ink composition is preferably 10.0% by mass or less, and more preferably 0.1 to 5.0% by mass.

[0017] (Other materials that may be included in the printing layer) The printing ink composition for forming the printed layer in the present invention may further contain various additives such as antistatic agents and plasticizers. Known methods can be used to produce such printing ink compositions. Specifically, for example, a mixture of pigment, binder resin, organic solvent, and optionally a pigment dispersant can be kneaded using a high-speed mixer, ball mill, sand mill, attritor, etc., and then the remaining materials, such as predetermined additives, can be added and mixed.

[0018] (Method for forming the printed layer) The method for forming a printed layer according to the present invention will be described. For example, a substrate such as a resin film is printed once or more times using a gravure printing method with a printing ink composition other than white. Then, on the non-white printed layer formed by this printing (on the opposite side of the substrate layer from the perspective of the printed layer), a white printing ink composition is printed once or more times using a gravure printing method to obtain the printed layer according to the present invention. Note that only one of the non-white printed layer and the white printed layer may be formed. Furthermore, drying may be performed using a dryer at any stage during the printing process.

[0019] <Adhesive layer> The adhesive layer is an optional layer formed between the substrate layer and the fragrance-retaining layer containing a hydroxyl group-containing polyester resin with a glass transition temperature of 40 to 120°C, and has the function of adhering these layers to each other. Alternatively, the adhesive layer is formed between the printed layer and the fragrance-retaining layer containing a hydroxyl group-containing polyester resin with a glass transition temperature of 40-120°C, and has the function of adhering these layers to each other. The adhesive used to form such an adhesive layer is not particularly limited as long as it performs the functions described above. The adhesive layer is formed by known means, such as applying an adhesive composition onto the printed layer, and is obtained by curing as necessary. In particular, a layer formed from a two-component curing polyurethane resin adhesive is preferred because it exhibits an even better balance between adhesion and the overall fragrance retention of the laminate. Especially, using an adhesive containing a polyol compound and a polyisocyanate compound, and having the adhesive layer contain a reaction product of the polyol compound and polyisocyanate compound, is preferable for further enhancing this effect. From an environmental perspective, a two-component, curable biomass polyurethane resin-based adhesive is more preferable as the adhesive composition. To obtain particularly good adhesion, adhesive compositions used in dry lamination may be used.

[0020] (Polyol compounds) The polyol compound contained in the aforementioned two-component curable polyurethane resin adhesive is preferably a polyol component that is an aromatic polyol, aliphatic polyol, aliphatic polyester, or aliphatic polyester compound having at least two hydroxyl groups in its molecule. Examples of such polyol components include polyurethane polyols, polyester polyols, polyether polyols, and acrylic polyols, and two or more of these polyol components may be mixed and used. Among these, polyurethane polyols, polyester polyols, and polyether polyols are preferred because their glass transition temperature and storage modulus are easily controlled. From an environmental perspective, biomass polyol components are preferred as polyol components. Biomass polyester polyols are particularly preferred.

[0021] (Polyisocyanate compounds) Similarly, as the polyisocyanate compound, a polyisocyanate compound having at least two or more isocyanate groups in the molecule is preferred. Examples of such polyisocyanate compounds include aromatic aliphatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates, and two or more such polyisocyanate compounds may be used in mixture form. Examples of aromatic aliphatic diisocyanates include 1,3- or 1,4-xylylene diisocyanate or mixtures thereof, 1,3- or 1,4-bis(1-isocyanato-1-methylethyl)benzene or mixtures thereof, ω,ω'-diisocyanato-1,4-diethylbenzene, and the like.

[0022] Examples of aliphatic diisocyanates include hexamethylene diisocyanate, tetramethylene diisocyanate, 2-methylpentane-1,5-diisocyanate, 3-methylpentane-1,5-diisocyanate, lysine diisocyanate, and trioxyethylene diisocyanate. Examples of alicyclic diisocyanates include isophorone diisocyanate, cyclohexyl diisocyanate, hydrogenated diphenylmethane diisocyanate, norbornane diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylene diisocyanate, and hydrogenated tetramethylxylene diisocyanate. Furthermore, two or more of these polyisocyanate compounds may be used in combination. It is also preferable to use an isocyanate component with three or more functionalities.

[0023] Examples of adhesive compositions used in dry lamination include DIC Dry LX-401A, 75A, 719, 703VL, 500, 510, etc. (DIC Graphics Co., Ltd., DIC Dry is a registered trademark of DIC Graphics Co., Ltd.), Takelac / Takenate A-969 / A-5, A-909 / A-5, A-977 / A-92, A-606 / A-50, A-515 / A-50, A-626 / A-50, A-525 / A-52, A-666 / A-65, etc. (Mitsui Chemicals, Inc.), RU-77, 771, 3600, 3900, etc. (Rock Paint Co., Ltd.), etc. Furthermore, from an environmental and safety standpoint, it is preferable to use biomass polyol compounds and biomass polyisocyanate compounds for the above-mentioned polyol compounds and polyisocyanate compounds.

[0024] <Fragrance retention layer> The fragrance-retaining layer is a layer formed from a coating composition containing a hydroxyl group-containing polyester resin with a glass transition temperature of 40 to 120°C. The fragrance-retaining layer may be a layer formed from a hydroxyl-containing polyester resin with a glass transition temperature of 40 to 120°C and a polyisocyanate curing agent (a hydroxyl-containing polyester resin curing layer with a glass transition temperature of 40 to 120°C). The layer included in this configuration may be a layer formed by applying a fragrance-retaining coating composition containing a hydroxyl-containing polyester resin with a glass transition temperature of 40 to 120°C and a curing agent, followed by drying and / or curing. Alternatively, the hydroxyl-containing polyester resin with a glass transition temperature of 40 to 120°C and a curing agent may be reacted beforehand, and a fragrance-retaining coating composition containing this reaction product may be applied and dried to form the layer. Alternatively, the layer may be formed from a hydroxyl group-containing polyester resin with a glass transition temperature of 40-120°C without the use of a curing agent. Furthermore, the fragrance-retaining layer is derived from the fragrance-retaining coating composition and contains trace amounts of residual solvent that cannot be completely removed under normal application conditions.

[0025] (Hydroxyl group-containing polyester resin with a glass transition temperature of 40-120°C) In the present invention, one or more hydroxyl group-containing polyester resins with a glass transition temperature of 40 to 120°C can be used. As the hydroxyl group-containing polyester resin with a glass transition temperature of 40 to 120°C in the present invention, a hydroxyl group-containing polyester resin with a glass transition temperature of 40 to 120°C that is a condensate of a low molecular weight diol and a dibasic acid is preferred.

[0026] The low molecular weight diol is preferably at least one of an aliphatic diol, an alicyclic diol, and an aromatic diol. Examples of aliphatic and alicyclic diols include ethylene glycol, diethylene glycol, dipropylene glycol, tripropylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 1,2-propanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, 1,4-pentanediol, 3-methyl-1,5-pentanediol, and 2,5-hexanediol. Preferably, one or more low molecular weight diols selected from those having or not having a branched structure, such as ethylene glycol, 2-methyl-1,4-pentanediol, 2,4-diethyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-methyl-1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,2,4-trimethyl-1,6-hexanediol, cyclohexanedimethanol, and tricyclodecanedimethanol, are used. However, the low molecular weight diol may consist only of ethylene glycol, or other low molecular weight diols may be used in combination.

[0027] Examples of aromatic diols include hydroquinone, resorcinol, catechol, naphthalenediol, biphenol, bisphenol A, bisphenol F, tetramethylbiphenol, their ethylene oxide extensions, and hydrogenated alicyclic compounds. Furthermore, if necessary, the above low molecular weight diol may be combined with a polyhydric alcohol of trivalent or higher, such as glycerin, trimethylolpropane, trimethylolethane, tris(2-hydroxyethyl) isocyanurate, 1,2,4-butanetriol, pentaerythritol, or dipentaerythulitol, but this is not required.

[0028] The dibasic acids mentioned above are preferably polycarboxylic acids such as aliphatic dibasic acids or aromatic dibasic acids, such as adipic acid, phthalic acid, isophthalic acid, terephthalic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, maleic acid, fumaric acid, succinic acid, sebacic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, superiric acid, and azelaic acid, or their anhydrides. Furthermore, if necessary, the above dibasic acid may be combined with a trifunctional or higher polybasic acid such as trimellitic acid or pyromellitic acid, but this is not required.

[0029] A hydroxyl group-containing polyester resin with a glass transition temperature of 40-120°C does not necessarily have to be a polyester polyol having an isocyanuric ring. To obtain a polyester polyol by reacting the above diol compound with a dibasic acid, these are reacted in the presence of a catalyst. For this type of catalyst, commonly used catalysts for the reaction between diol compounds and dibasic acids can be employed.

[0030] The glass transition temperature of hydroxyl group-containing polyester resins with a glass transition temperature of 40-120°C is the measured glass transition temperature determined by thermal analysis. The thermal analysis method follows JIS K7121 (Method for Measuring Transition Temperature of Plastics). For example, the glass transition temperature can be measured using a PerkinElmer Pyris1 DSC under conditions of a heating rate of 20°C / min and a nitrogen gas flow rate of 20 ml / min. The glass transition temperature of hydroxyl group-containing polyester resins is 40 to 120°C. Preferably it is 50°C or higher, more preferably 55°C or higher, even more preferably 58°C or higher, and most preferably 62°C or higher. Also preferably it is 110°C or lower, more preferably 100°C or lower, even more preferably 95°C or lower, and most preferably 90°C or lower. For polyester resins with a glass transition temperature of 40-120°C, a glass transition temperature below 40°C tends to reduce fragrance retention, while a glass transition temperature above 120°C tends to result in a harder coating film, leading to reduced adhesion and fragrance retention.

[0031] (Hydroxyl value) The hydroxyl value of the hydroxyl group-containing polyester resin with a glass transition temperature of 40 to 120°C is preferably 1 to 200 mg KOH / g, more preferably 1 to 100 mg KOH / g, and even more preferably 1 to 50 mg KOH / g. The hydroxyl value can be determined by applying the method specified in JIS K1557-1:2007. Specifically, the hydroxyl groups of the polyester resin sample are acetylated by dissolving it in a pyridine solution containing an acetylating reagent (e.g., acetic anhydride). Then, the excess acetylating reagent is hydrolyzed with water, and the amount of acetic acid produced is titrated with potassium hydroxide. At this time, the carboxyl groups contained in the polyester resin are also titrated by potassium hydroxide, so the hydroxyl value (mgKOH / g) is calculated by subtracting the acid value of the polyester resin from the titration result. Examples of such polyester resins include ELITER UE9800 (Unitika Corporation) (a copolymer polyester containing ethylene glycol and propylene glycol as diol copolymer components, and terephthalic acid as a dicarboxylic acid copolymer component), ELITER UE-3350 (Unitika Corporation), ELITER UE-9200 (Unitika Corporation), and DYNAPOL L 912 (EVONIK Corporation).

[0032] (Acid value) The acid value of the hydroxyl group-containing polyester resin with a glass transition temperature of 40 to 120°C is preferably 1 to 200 mg KOH / g, more preferably 1 to 100 mg KOH / g, and even more preferably 1 to 50 mg KOH / g. The acid value can be determined by the method specified in JIS K5601-2-1:2007. Examples of such polyester resins include ELITER UE9800 (Unitika Corporation) (a copolymer polyester containing ethylene glycol and propylene glycol as diol copolymer components, and terephthalic acid as a dicarboxylic acid copolymer component), ELITER UE-3350 (Unitika Corporation), ELITER UE-9200 (Unitika Corporation), and DYNAPOL L 912 (EVONIK Corporation).

[0033] (average molecular weight) The number-average molecular weight of the polyester resin is preferably in the range of 2,000 to 100,000. The number-average molecular weight of polyester resin is the number-average molecular weight when converted to standard polystyrene using GPC measurement. Furthermore, the viscosity-average molecular weight of the polyester resin is preferably in the range of 2,000 to 100,000. The viscosity-average molecular weight of polyester resin can be determined by applying the method specified in JIS K7252.

[0034] (Hardening agent) Polyisocyanate curing agents (polyisocyanate compounds) can be used as curing agents, or they may not be used at all. Examples of polyisocyanate compounds include aromatic aliphatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates. Among these, isocyanate curing agents with three or more functionalities are preferred. Furthermore, the laminate of the present invention may or may not contain residual unreacted curing agent in the aroma-retaining layer after curing.

[0035] Specific examples of aromatic aliphatic diisocyanates include 1,3- and / or 1,4-phenylenediisocyanate, 4,4-diisocyanatobiphenyl, 3,3-dimethyl-4,4-diisocyanatobiphenyl, 1,3- or 1,4-xylylenediisocyanate, 1,3- or 1,4-bis(1-isocyanato-1-methylethyl)benzene or mixtures thereof, ω,ω'-diisocyanato-1,4-diethylbenzene, α,α,α',α'-tetramethylxylylenediisocyanate, and the like.

[0036] Specific examples of aliphatic diisocyanates include 1,6-hexamethylene diisocyanate, tetramethylene diisocyanate, 2-methylpentane-1,5-diisocyanate, 3-methylpentane-1,5-diisocyanate, lysine diisocyanate, and trioxyethylene diisocyanate. Specific examples of alicyclic diisocyanates include isophorone diisocyanate, cyclohexane diisocyanate, hydrogenated diphenylmethane diisocyanate, norbornane diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylene diisocyanate, and hydrogenated tetramethylxylene diisocyanate. Furthermore, it is acceptable to use a mixture of two or more such isocyanate compounds.

[0037] Furthermore, it is preferable to use components such as adducts obtained by reacting the above polyisocyanate compound with low molecular weight active hydrogen compounds such as ethylene glycol, propylene glycol, metaxylylene alcohol, 1,3-bishydroxyethylbenzene, 1,4-bishydroxyethylbenzene, trimethylolpropane, glycerol, pentaerythritol, erythritol, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, triethanolamine, and metaxylylenediamine, and their alkylene oxide adducts, various polyester resins, polyether polyols, and high molecular weight active hydrogen compounds such as polyamides, biuret compounds obtained by trimerizing the above diisocyanate compound, and isocyanurate compounds obtained by isocyanurating the above diisocyanate compound.

[0038] From an environmental perspective, a biomass curing agent containing both a biomass polyol compound and a biomass polyisocyanate compound is preferred. However, a non-biomass curing agent is also acceptable. As a biomass curing agent, a trifunctional isocyanate compound having an isocyanurate ring obtained by nurating biomass diisocyanate may also be used. Biomass isocyanates can also be obtained by using plant-derived amino acids as raw materials and converting their amino groups to isocyanate groups. For example, lysine diisocyanate (LDI) is obtained by methyl esterifying the carboxyl group of lysine and then converting the amino group to an isocyanate group. Similarly, 1,5-pentamethylene diisocyanate is obtained by decarboxylating the carboxyl group of lysine and then converting the amino group to an isocyanate group. Polymers or oligomers obtained by polymerizing the above isocyanate compounds and diol compounds so that the terminal ends are isocyanate groups can also be used. As a trifunctional isocyanate compound having an isocyanurate ring, a trifunctional isocyanate compound having an isocyanurate ring obtained by nurating an isocyanate having two isocyanate groups in the molecule can be used. The chemical equivalent ratio of the hydroxyl groups of the polyol compound to the isocyanate groups of the polyisocyanate compound in the curing agent (isocyanate groups of the polyisocyanate compound) / (hydroxyl groups of the polyol compound) is preferably 100% to 500%.

[0039] (solvent) Organic solvents and / or water can be used as solvents, but those with low boiling points are preferred in order to reduce residual solvent. Examples of organic solvents include toluene, ketone-based organic solvents (e.g., acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.), ester-based solvents (e.g., methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, isobutyl acetate, etc.), alcohol-based solvents (e.g., methanol, ethanol, n-propanol, isopropanol, butanol, etc.), and hydrocarbon-based solvents (e.g., toluene, methylcyclohexane, etc.). To reduce residual solvent, ketone-based organic solvents (e.g., acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.) and ester-based organic solvents (e.g., ethyl acetate, etc.) are preferred. Since the laminate of the present invention has a fragrance-retaining layer immediately inside the sealant layer, even when it is used as a container, there is no possibility that residual solvent will pass through the sealant layer or the like, diffuse the residual solvent outside the container, or impart the odor of the residual solvent to the items inside the container.

[0040] (Other ingredients) Other components that the fragrance-retaining coating composition may contain, to the extent that they do not impair the effects of the present invention, include hydroxyl group-containing polyester resins other than hydroxyl group-containing polyester resins with a glass transition temperature of 40 to 120°C, and other polyol compounds. It may also contain pigments such as known extender pigments and coloring pigments, pigment dispersants, dyes, and the like.

[0041] Furthermore, a catalyst can be used during the reaction between the polyester polyol and the isocyanate curing agent. Among these, organometallic compounds are preferred, and such organometallic compounds include titanium compounds such as dibutyltitanium dichloride, tetrabutyltitanate, and butoxytitanium trichloride, as well as dibutyltin sulfide, tributyltin sulfide, tributyltin oxide, dibutyltin dichloride, dibutyltin oxide, dibutyltin dibromide, dibutyltin dimaleate, dibutyltin dilaurate, dibutyltin diacetate, dioctyltin dilaurate, and tributyltin dichloromide. Examples include tin acetate, tributyltin chloride, triethyltin ethoxide, tributyltin ethoxide, dioctyltin oxide, tributyltin trichloroacetate, and tin 2-ethylhexanoate; lead compounds such as lead oleate, lead 2-ethylhexanoate, lead benzoate, and lead naphthenate; and iron 2-ethylhexanoate, iron acetylacetonate, cobalt benzoate, cobalt 2-ethylhexanoate, zinc naphthenate, zinc 2-ethylhexanoate, and zirconium naphthenate. Among these, titanium compounds such as tetrabutyl titanate are preferred. Tertiary amine compounds can also be used, for example, triethylamine, triethylenediamine, 1,4-diazabicyclo(2.2.2)octane, and 1,8-diazabicyclo(5.4.0)-undecene-7 (DBU).

[0042] (Method for forming a fragrance-retaining layer) The fragrance-retaining layer in the present invention can be formed on the sealant layer described below by known means using a fragrance-retaining coating composition. When forming the fragrance-retaining layer on the sealant layer, the fragrance-retaining layer is provided between the adhesive layer and the sealant layer by overlapping the surface of the sealant layer on the fragrance-retaining layer side with the surface of the adhesive layer by dry lamination. The known methods mentioned above include roll coating methods using gravure cylinders, doctor knife methods, air knife / nozzle coating methods, bar coating methods, spray coating methods, dip coating methods, and coating methods that combine these methods.

[0043] The dry coating amount (coating amount after drying) of the fragrance retention layer in the laminate of the present invention varies depending on the thickness and material of the above-mentioned base material layer and the target fragrance retention level, but is 0.08 to 5.0 g / m 2 and is preferably so. Also, from the viewpoint of reducing the residual solvent in the fragrance retention layer and obtaining appropriate fragrance retention, it is preferably 1.5 g / m 2 or less. When the coating amount is less than 0.08 g / m 2 , there is a possibility that the target fragrance retention cannot be obtained, and even if it exceeds 5.0 g / m 2 , it is difficult to further improve the fragrance retention, and moreover, a large amount of residual solvent derived from the components of the fragrance retention coating composition may remain in the fragrance retention layer. Preferably it is 0.08 g / m 2 or more, more preferably 0.15 g / m 2 or more, and still more preferably 0.2 g / m 2 or more. The laminate of the present invention has sufficient fragrance retention even when the coating amount of the solid content of the fragrance retention layer is 0.15 to 1.0 g / m 2 and is a very thin layer.

[0044] <Sealant layer> For the sealant layer, a known sealant layer can be used, and examples include polyolefins such as uniaxially stretched polyethylene, uniaxially stretched polypropylene, biaxially stretched polyethylene, biaxially stretched polypropylene, unstretched polyethylene, unstretched polypropylene, etc., ethylene-vinyl acetate copolymers, etc., and films for dry lamination processing. In the present invention, when a stretched polyethylene film is used as the base material layer, aspects other than the laminate using an ethylene-based heat seal layer as the sealant layer can be excluded. Also, when the sealant layer has the performance as the base material layer, the base material layer is not necessarily required.

[0045] <Laminate> To obtain the laminate of the present invention, the fragrance-retaining coating composition is applied to the sealant layer shown in the figure below and dried, as described above. When a fragrance-retaining layer is provided on the sealant layer in advance, it is obtained by overlapping and integrating the fragrance-retaining layer side of the fragrance-retaining layer, which is integrated with the sealant layer, onto the pre-provided adhesive layer using a known dry laminating machine, in accordance with a normal dry lamination method.

[0046] (Other functional layers) Furthermore, the laminate of the present invention may have one or more functional layers between the base film and the sealant film, to the extent that they do not impair the effects of the present invention, for the purpose of improving gas barrier properties or reinforcing strength. Examples of such functional layers include vapor-deposited layers of silica, alumina, or metal or other resin layers for the purpose of improving gas barrier properties such as oxygen, stretched nylon film layers for the purpose of improving the strength reinforcement of the laminated film, and nylon-based metaxylenediamine resin film layers for the purpose of improving both of the above functions. These various functional layers can be formed by vapor deposition onto any layer such as a substrate layer or sealant layer, by forming a coating film, or by laminating films. The laminate of the present invention may or may not have a layer made of ethylene-vinyl alcohol copolymer, polyvinyl alcohol, or polyamide, an inorganic compound layer such as a metal layer or a metal oxide layer, or a layer containing a metal-containing pigment. Furthermore, a desorption layer may be provided in any of the layers in the present invention. By providing a desorption layer, the laminate can be broken down into smaller pieces after use and decomposed by immersing it in water with a basic solution, etc.

[0047] (Applications of the laminated material of the present invention) The laminate of the present invention, comprising a base layer, a printed layer, an adhesive layer, a fragrance-retaining layer containing a hydroxyl group-containing polyester resin with a glass transition temperature of 40 to 120°C, and a sealant layer in that order, is exclusively for packaging films, and in particular for containers such as bags that airtightly package solid or liquid items containing fragrance components, such as foods that naturally contain fragrance components, such as coffee powder, coffee beans, and tea leaves, foods with added fragrances, cosmetics, detergents, shampoos, and conditioners. To achieve this, the sealant layers of the laminate are pressed together by heating or other means to seal the packaged items and prevent the fragrance components from being released outside the container. Therefore, when the laminate of the present invention is used in a container that can be airtightly sealed, it is possible to prevent the fragrance from leaking out of the container by allowing the fragrance components to penetrate or permeate at least the laminate of the present invention. Furthermore, the laminate of the present invention can reduce residual solvents. Furthermore, the packaging film laminate of the present invention is a laminate having a fragrance-retaining layer containing a hydroxyl group-containing polyester resin with a glass transition temperature of 40 to 120°C on top of a pre-formed specific sealant layer, in order to form a laminate having the above-described base layer, printing layer, adhesive layer, fragrance-retaining layer, and sealant layer.

[0048] If necessary, the laminate can be further modified to include another layer to prevent the permeation of, for example, oxygen, carbon dioxide, or water. This allows the laminate as a whole to simultaneously prevent the permeation of fragrance components and oxygen, carbon dioxide, and water. A layer to block ultraviolet rays may also be included. Laminates having these layers may protect, seal, and package their contents without having metal layers or metal oxide layers. Furthermore, it can be used to package contents that previously required a metal layer or similar to prevent the permeation of fragrance components. Furthermore, it is possible to create a laminate that allows oxygen, carbon dioxide, and water to pass through, but prevents the transmission of aroma components, without providing a separate layer to prevent the permeation of these substances. In that case, the oxygen barrier property of the laminate is 100 cc / m². 2 It can be made to be more than 2000 yen per day / atm. The form of the container using the laminate of the present invention is not particularly limited. The laminate of the present invention may be used for the entire container, or it can be used as a component such as a lid or seal that adheres tightly to the container body having aroma-retaining properties, such as a bag, glass container, or resin injection molded or extruded product.

[0049] (Fragrance components) The fragrance components whose permeation is prevented by the layer formed by the fragrance-retaining coating composition of the present invention are the fragrance components contained in the above-mentioned solids or liquids that are packaged in containers formed using the packaging material having this layer. Such fragrance components include fragrance components derived from raw materials used to obtain the solid or liquid (for example, if the solid or liquid is a food product, these may include spices, meat, vegetables, fruits, fish, dairy products, seasonings, oils, etc.), as well as natural and synthetic fragrance components added during the manufacturing of products such as food products, fabric softeners, liquid detergents, shampoos, conditioners, antiperspirants, wet wipes, cosmetics, air fresheners for rooms and cars, and scented stationery, for the purpose of adding fragrance. Furthermore, the definition is not limited to the fragrance components of these items. Furthermore, preventing the permeation of aromatic components does not necessarily mean preventing the permeation of substances other than aromatic components, such as oxygen and nitrogen. [Examples]

[0050] <Fabrication of laminates> In the examples and comparative examples, we obtained laminates having two types of layer configurations, A (Figure 1A) and B (Figure 1B), which differ in the location of the aroma-retaining layer. (A. Laminates in which a fragrance-retaining layer is provided on a sealant layer (Examples 1-13 and Comparative Examples 1-2)) A laminate consisting of layers in the following order: base material layer / printing ink layer / adhesive layer / fragrance retention layer / sealant layer. The following printing ink composition was applied to the entire surface of one side of the substrate layer, which is either OPP or MDOPE, using a wire bar and then dried. Next, apply the adhesive listed below using a wire bar, at a rate of 3.0g / m² after drying. 2 The material was applied in this manner and dried to obtain an adhesive layer. Separately from the laminate consisting of the base layer, printing ink layer, and adhesive layer obtained above, each fragrance-retaining layer composition obtained by stirring and mixing each component shown in the table below is applied to one side of the sealant layer, which is CPP or LLDPE, using a wire bar, and dried. After drying, the application amount is 0.6 and 0.3 g / m². 2 A fragrance-retaining layer was obtained for each application amount in such a manner. These laminates were bonded together by stacking them so that the surface of the laminate consisting of the sealant layer and the fragrance-retaining layer on the fragrance-retaining layer side and the surface of the laminate consisting of the above-mentioned base material layer / printing ink layer / and adhesive layer on the adhesive layer side, and then aged at 40°C for 3 days to obtain each laminate.

[0051] (B. Laminates in which a fragrance-retaining layer is provided between the substrate layer and the printing ink layer (Comparative Examples 3-13)) A laminate consisting of layers in the following order: base material layer / fragrance retention layer / printing ink layer / adhesive layer / sealant layer. Each fragrance-retaining layer composition, obtained by stirring and mixing the components shown in the table below, is applied to one side of the base layer using a wire bar, dried, and then coated at a rate of 0.6 and 0.3 g / m² after drying. 2 A fragrance-retaining layer was obtained for each application amount in such a manner. The following printing ink composition was applied to the resulting fragrance-retaining layer using a wire bar and dried. Furthermore, apply the following adhesive to the printed layer after drying, at a rate of 3.0 g / m². 2 The adhesive was applied using a wire bar and allowed to dry to obtain the adhesive layer. The following sealant layers were directly bonded onto the resulting adhesive layer, and each laminate was obtained by aging at 40°C for 3 days.

[0052] (C. Laminate without a fragrance-retaining layer (Comparative Example 14)) A laminate consisting of layers in the following order: base material layer / printing ink layer / adhesive layer / sealant layer. The following printing ink composition was applied to the entire surface of one side of the base layer, which was either OPP or MDOPE, using a wire bar and then dried. Furthermore, apply the following adhesive to the printed layer after drying, at a rate of 3.0 g / m². 2 The adhesive was applied using a wire bar and allowed to dry to obtain the adhesive layer. The sealant layer described below was directly bonded onto the resulting adhesive layer, and the laminate was obtained by aging at 40°C for 3 days.

[0053] <Method for preparing a laminate for residual solvent measurement> In Examples 1-13 and Comparative Examples 1-2, ink was printed onto the substrate layer, and then an adhesive layer was added. Separately, a fragrance-retaining layer composition was applied to the sealant layer, and the adhesive layer and the fragrance-retaining layer were dry-laminated together. In Comparative Examples 3-13, a fragrance-retaining layer was first formed on the substrate layer, followed by ink printing, and then the sealant layer was dry-laminated via the adhesive layer. Comparative Example 14 was the same laminate as in Example 1 except that a fragrance-retaining layer was not provided. The ink used was the blue ink and white ink described below, diluted in a solvent mixed in a mass ratio of ethyl acetate / propyl acetate / isopropyl alcohol = 50 / 30 / 20, and adjusted to a viscosity of 15 seconds using a Rigo cup No. 3. The results shown in the table below are obtained when a solid layer of blue ink was printed and dried on the substrate layer, followed by a solid layer of white ink and drying.

[0054] (Printing conditions for reverse-printing ink compositions) Coating machine: Gravure printing machine Coating speed: 100 m / min Printing plate: Helio 175 line / inch 15 (130°) solid plate Drying temperature: 55℃ (Application conditions for each fragrance-retaining layer composition) Coating machine: Gravure printing machine Coating speed: 100 m / min Printing plate: Helio 250 line / inch (130°) solid plate Drying temperature: 80℃

[0055] (base material layer) OPP (Biaxially oriented polypropylene film (P2161, 25 μm thickness, Toyobo Co., Ltd.)) MDOPE (Uniaxially oriented polyethylene film (PE3K-H, 25 μm thickness, Futamura Chemical Co., Ltd.)) )

[0056] (Printing ink composition) Blue ink: Bellflora R Blue 800 (Sakata Inx Co., Ltd.) White ink: Bellflora R White 115 (Sakata Inx Co., Ltd.)

[0057] (glue) Adhesive: Takelac A-969 / Takenate A-5 (Mitsui Chemicals, Inc.), solids content 30% by mass

[0058] (Hydroxyl group-containing polyester resin with a glass transition temperature of 40-120°C) Elitel UE-9800: Polyester resin (Unitika Corporation) Tg: 85℃, Hydroxyl value 4mgKOH / g, Acid value 3mgKOH / g, Viscosity average molecular weight 13000 Elitel UE-3350: Polyester resin (Unitika Corporation) Tg: 52℃, Hydroxyl value 25 mg KOH / g, Acid value 1 mg KOH / g, Viscosity average molecular weight 5000 Elitel UE-9200: Polyester resin (Unitika Corporation) Tg: 65℃, Hydroxyl value 6mgKOH / g, Acid value 1mgKOH / g, Viscosity average molecular weight 15000 DYNAPOL L912: Polyester resin (EVONIK) Tg: 105℃, Hydroxyl value 5mgKOH / g, Acid value 3mgKOH / g, Number average molecular weight 15000 (Hydroxygroup-containing polyester resin with a glass transition temperature outside the range of 40-120°C) Polyester LP-035: Polyester resin (Mitsubishi Chemical Corporation) Tg: 20℃, hydroxyl value 2-8 mg KOH / g

[0059] (Hardening agent for fragrance retention layer) Duranate 24A-90E: HDI-Biuret (Asahi Kasei Corporation) NCO content = 21.2% by mass Takenate D-110N: XDI-TMP Adduct (Mitsui Chemicals, Inc.) NCO content = 11.5% by mass Desmodur ultra Z4470BA: IPDI-isocyanurate (Sumika Covestro Co., Ltd.) NCO content = 11.9% by mass (Solvent for forming a fragrance-retaining layer) MEK: Methyl ethyl ketone ethyl acetate

[0060] (Sealant layer used) CPP (Unoriented Polypropylene Film (P1128, 25μm thickness, Toyobo Co., Ltd.)) LLDPE (Linear low-density polyethylene unoriented film (Unilux LS-711C, 50 μm thickness, Idemitsu Unilux Co., Ltd.))

[0061] The resulting laminates were measured for their aroma retention, laminate strength, residual solvent content, and oxygen barrier properties.

[0062] <Fragrance retention test method> The above laminate was cut into 7cm squares, and one side was folded in half, with the long and short sides heat-sealed. The resulting bag-like material was then filled with either curry powder (1g) or coffee powder (1g), or fabric softener (4g) or liquid shampoo (4g), and the remaining side was heat-sealed to create a sealed bag-like material. The prepared bag-like material was placed in a glass bottle and sealed, and the leakage of fragrance after storage at 23°C for 7 days was evaluated as follows. Five testers skilled in fragrance evaluation checked the fragrance atmosphere inside the glass bottle and judged it according to the following criteria. The table below shows the amount of fragrance leakage that was evaluated as being most highly by the testers. Curry powder: Red can curry powder (S&B Foods Co., Ltd.) Coffee powder: Blendy Instant Coffee (Ajinomoto AGF Co., Ltd.) Fabric softener: Soflan Aroma Rich Sweet Floral Aroma scent (LION Corporation) Liquid Shampoo: Pantene Effortless Complete Night Repair Shampoo (P&G) ◎: No fragrance leakage ○: Slight fragrance leakage present. △: Scent leakage present ×: Strong scent leaking out.

[0063] <Method for evaluating laminate strength> Each laminate was cut into 15 mm wide strips, and the T-type peel strength (N / 15 mm) was measured using a peel tester (Yasuda Seiki Seisakusho Co., Ltd.) as the peel strength.

[0064] <Method for evaluating residual solvents> Each laminate (0.2 m²) having a fragrance-retaining layer and / or printed layer of the examples and comparative examples prepared for residual solvent measurement. 2 The solution is placed in a 500 ml flask and heated in an oven at 80°C for 30 minutes to vaporize the solvent remaining in the laminate. 1 ml of the gas is taken from the flask and the amount of residual solvent per unit area (mg / m²) is determined by gas chromatography. 2 The amount of residual solvent in the substrate layer and sealant layer having a fragrance-retaining layer and / or a printed layer was measured. The sum of the residual solvent amounts in the substrate layer and sealant layer was marked with ○ or × according to the following criteria. ○: 30 mg / m² 2 less than ×: 30 mg / m² 2 That's all.

[0065] <Method for evaluating oxygen barrier properties> The oxygen permeability (OTR value) of each laminate was measured using an oxygen permeability analyzer (Mocon, product name: OX-TRAN1 / 50) in accordance with JIS K7126 Method B. The measurements were performed at 25°C in a 0% RH atmosphere. ○: 100cc / m 2 Less than 1 day at a meter ×: 100cc / m 2 ·day · atm or more

[0066] [Table 1]

[0067] [Table 2]

[0068] [Table 3]

[0069] In each example (A. Laminate in which a fragrance-retaining layer is provided between the sealant layer and the adhesive layer), it was possible to obtain a laminate with sufficient fragrance retention and low residual solvent. Furthermore, as in Examples 1 to 9, when the fragrance-retaining layer was obtained by containing a polyisocyanate curing agent, it was possible to obtain a laminate with even better laminate strength. In contrast, Comparative Examples 1 and 2 (A. Laminates in which a fragrance-retaining layer is provided between the sealant layer and the adhesive layer) failed to exhibit sufficient fragrance retention because they contained only hydroxyl group-containing polyester resins with excessively low glass transition temperatures. B. In Comparative Examples 3-13, where the aroma-retaining layer was placed between the substrate layer and the printing layer, a large amount of residual solvent was found in the laminate. Furthermore, in Comparative Example 14, which lacked a fragrance-retaining layer, the residual solvent was low, but it did not retain fragrance. Although the conditions for providing each layer constituting the laminate were common to both the Examples and Comparative Examples 1-13, by particularly considering the location of the fragrance-retaining layer within the laminate and constructing the laminate in the location specified in the present invention, we obtained the excellent effect of reducing residual solvent. Furthermore, considering the results of Comparative Example 14, it can be seen that by including the fragrance-retaining layer of the present invention, the laminate of the present invention not only has good fragrance retention properties but also exhibits the effect of reducing residual solvents. In addition, the oxygen barrier properties were insufficient in all of Examples 1-13 and Comparative Examples 1-14. In other words, it was found that the excellent aroma retention of the laminates in Examples 1-13 was not directly related to the degree of oxygen barrier properties.

Claims

1. A laminate having a sealant layer containing a hydroxyl group-containing polyester resin with a glass transition temperature of 40 to 120°C, and a sealant layer.

2. The laminate according to claim 1, comprising, in order, a base layer, a printed layer, an adhesive layer, a fragrance-retaining layer containing a hydroxyl group-containing polyester resin having a glass transition temperature of 40 to 120°C, and a sealant layer.

3. The laminate according to claim 1 or 2, wherein the fragrance-retaining layer is formed from a hydroxyl group-containing polyester resin having a glass transition temperature of 40 to 120°C and a polyisocyanate curing agent.

4. The laminate according to claim 3, wherein the polyisocyanate curing agent is a polyisocyanate curing agent with three or more functionalities.

5. The amount of the fragrance-retaining layer applied after drying is 0.15 to 1.0 g / m². ２ The laminate according to claim 1 or 2.

6. A laminate for packaging films having a sealant layer and a fragrance-retaining layer containing a hydroxyl group-containing polyester resin with a glass transition temperature of 40 to 120°C.

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