JP5580067B2 - Laminated body and lid material using the same - Google Patents

Description

  The present invention relates to a laminate and a lid material using the laminate, and more particularly to a laminate suitable for a lid of a polypropylene resin or polystyrene resin container and a lid material using the laminate.

  Conventionally, as a cover material for a synthetic resin container for storing water-containing contents such as pudding, yogurt, jelly, syrup, etc., for example, a laminate composed of a resin film / metal foil / heat seal layer has been used. Yes. However, since the resin film and the metal foil cannot be completely separated from each other, they cannot be separated and collected, and there has been a problem in terms of recycling such that the metal foil remains as an unincinerated product during incineration. Further, since the metal foil is used, the lid member is opaque, and the contents cannot be confirmed through fluoroscopy, and there is a problem that foreign matter inspection by a metal detector cannot be performed. Furthermore, there is a possibility that fingers may be injured by the metal foil. In these respects, a cover material in which paper and a resin film are laminated has been developed in recent years without using the metal foil. However, with a lid made of paper and resin film, sufficient sealability and water resistance cannot be obtained, and the contents deteriorate due to poor sealing, or delaminate (delaminate) when opened to form a double lid, which is opened once There was a problem that it was not possible or that the heat sealant remained in the opening of the container. When a heat seal layer is provided on a metal foil, the heat seal agent is generally baked at a high temperature of 150 ° C. or more. However, when the resin film is baked at a high temperature, the resin film itself is softened and applied. There has been a problem that pitch deviation sometimes occurs and it is difficult to provide a heat seal layer. On the other hand, when a resin having a low softening point is used and a heat seal layer is provided on a resin film at a temperature of 100 ° C. or lower, there is a problem that blocking occurs.

JP-A-8-48849 JP 2003-26223 A JP 2003-226839 A JP 2004-168348 A

  The present invention is a laminate that does not include a metal foil, a heat seal layer can be provided at a temperature of 100 ° C. or less, and a laminate having excellent peel strength and sealing strength and a lid material using the laminate. The issue is to provide.

  The present invention is (1) a laminate in which an anchor coat layer and a heat seal layer are sequentially laminated on one surface of a base film containing a polyester resin, and the anchor coat layer is polymerizable with a polyester resin. A mixture of the polymer of vinyl group-containing monomers, the mixing ratio (parts by mass) of the polyester resin / polymer of the polymerizable vinyl group-containing monomer is 100/1 to 100/50, and the heat seal layer is styrene. -It is related with the laminated body characterized by including a butadiene-type copolymer resin.

  In the present invention, (2) the laminate according to (1), wherein the anchor coat layer is obtained by curing a mixture of a polyester resin and a polymer of a polymerizable vinyl group-containing monomer with polyisocyanate. About the body.

  The present invention also relates to (3) the laminate according to (1) or (2), wherein the heat seal layer contains at least one selected from a styrene resin, an acrylic resin, and talc.

  Moreover, this invention relates to the cover material of the container made from a polypropylene resin or a polystyrene resin which uses the laminated body as described in any one of (4) said (1)-(3).

  According to the present invention, a laminate that does not include a metal foil, a heat seal layer can be provided at a temperature of 100 ° C. or less, and a laminate having excellent peel strength and sealing strength, and a lid using the laminate. Material can be provided.

  The laminate of the present invention is a laminate obtained by sequentially laminating an anchor coat layer and a heat seal layer on one surface of a base film containing a polyester resin, and the anchor coat layer is polymerizable with the polyester resin. A mixture of the polymer of vinyl group-containing monomers, the mixing ratio (parts by mass) of the polyester resin / polymer of the polymerizable vinyl group-containing monomer is 100/1 to 100/50, and the heat seal layer is styrene. -A butadiene copolymer resin is included.

  The base film which is the outermost layer in the laminate of the present invention comprises a polyester resin. The polyester resin is not particularly limited and is obtained by reacting a polyvalent carboxylic acid component and a polyhydric alcohol component. Examples of the polyvalent carboxylic acid component include terephthalic acid, isophthalic acid, and phthalic acid. , Naphthalenedicarboxylic acid, diphenic acid, 1,4-dicyclohexanedicarboxylic acid, adipic acid, dodecanedioic acid, eicoic acid, azelaic acid, sebacic acid, trimellitic acid, pyromellitic acid, and derivatives thereof, etc. Examples of the polyhydric alcohol component include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, butylene glycol, neopentyl glycol, 3 -Methyl-1,5-pentanediol, , 3'-dimethylol heptane, polyoxyethylene glycol, polyoxypropylene glycol, polytetramethylene ether glycol, bisphenol and derivatives thereof. Furthermore, there may be mentioned polyester resins obtained by ring-opening polymerization of lactones such as polycaprolactone, polyvalerolactone and poly (β-methyl-γ-valerolactone). Among these polyester resins, polyethylene terephthalate, polybutylene terephthalate, and polytrimethylene terephthalate are preferable, and polyethylene terephthalate is particularly preferable.

  As the base film, a film containing a polyester resin may be used as a single layer or a plurality of layers. In the case of using a plurality of layers, for example, polyethylene terephthalate / polyethylene terephthalate, polyethylene terephthalate / paper / polyethylene terephthalate, etc.

  Examples of the base film include various additives such as calcium carbonate, titanium oxide, silicon oxide, calcium fluoride, lithium fluoride, alumina, barium sulfate, zirconia, calcium phosphate, and crosslinked polystyrene particles, and inorganic or organic particles. May be included.

  Although the thickness of the said base film is suitably selected according to the kind of polyester resin, a use, etc., Preferably it is 1-100 micrometers, More preferably, it is 10-50 micrometers.

In the laminate of the present invention, an anchor coat layer is provided on the base film in order to enhance the adhesion between the base film and the heat seal layer. The anchor coat layer in the present invention includes a mixture of a polyester resin and a polymer of a polymerizable vinyl group-containing monomer, and the mixing ratio (parts by mass) of the polyester resin / polymer of the polymerizable vinyl group-containing monomer is a solid content. in terms of 50 / 1-50 / 50, preferably 50 / 3-50 / 30, more preferably 50 / 5-50 / 25. In the present invention, by setting the mixing ratio (parts by mass) of the polymer of the polymerizable vinyl group-containing monomer to 50 parts by mass of the polyester resin to 1 to 50, the adhesion with the base film is improved and the laminate is peeled off. Strength and sealing strength can be improved.

  As the polyester resin that is a constituent component of the anchor coat layer, polyester polyol, polyether ester polyol, polyester amide polyol, polyester urethane polyol, or a mixture thereof is used.

  Examples of the polyester polyol include dibasic acids such as terephthalic acid, isophthalic acid, adipic acid, azelaic acid, and sebacic acid, or mixtures thereof, for example, ethylene glycol, propylene glycol, diethylene glycol, butylene glycol, Glycols such as neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 3,3′-dimethylol heptane, polyoxyethylene glycol, polyoxypropylene glycol, polytetramethylene ether glycol Alternatively, a polyester polyol obtained by reacting with a mixture thereof or a lactone such as polycaprolactone, polyvalerolactone, poly (β-methyl-γ-valerolactone) is opened. The polyester polyol obtained by superposition | polymerization is mentioned.

  Examples of the polyether ester polyol include dibasic acids such as terephthalic acid, isophthalic acid, adipic acid, azelaic acid, and sebacic acid, or dialkyl esters thereof, or mixtures thereof, for example, ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran. Examples include polyether ester polyols obtained by reacting polyether polyols obtained by polymerizing oxirane compounds such as water, ethylene glycol, propylene glycol, trimethylolpropane, glycerin and the like with low-part polyols as initiators. It is done.

  The polyesteramide polyol can be obtained, for example, by using an aliphatic diamine having an amino group such as ethylenediamine, propylenediamine, hexamethylenediamine as a raw material in the esterification reaction.

The polyester urethane polyol is a polyol having a urethane bond in one molecule. For example, a polyester polyol having a number average molecular weight of 200 to 20,000, a polyether ester polyol and the like and an organic polyisocyanate having an NCO / OH of less than 1, Preferably, it is obtained by reacting at 0.9 or less. The organic polyisocyanate is not particularly limited, and for example, those described below are used.
In the present invention, a partially acid-modified polyol obtained by reacting a polyester urethane polyol with trimellitic anhydride and trimellitic ester anhydride can be used. The blending ratio of trimellitic anhydride and trimellitic acid ester anhydride is not particularly limited, but 10 to 70% by mass of trimellitic anhydride and 90 to 30% by mass of trimellitic acid ester anhydride are preferable. Trimellitic acid ester anhydride is an ester compound obtained by esterifying a C2-C30 alkylene glycol or alkanetriol with trimellitic anhydride. In particular, if the alkylene glycol chain is too long, the density of the polar group of the urethane bond or ester bond decreases and the adhesiveness tends to decrease, and if alkanetriol is used, the risk of rapid thickening and gelation increases during synthesis. , Ethylene glycol bisanhydro trimellitate represented by the following formula (1) is preferable.

  Polymers of polymerizable vinyl group-containing monomers that are constituent components of the anchor coat layer include, for example, acrylic compounds, styrene compounds, vinyl glycidyl ether, (meth) allyl glycidyl ether, vinyl acetate, vinyl propionate, butadiene, Polymers of polymerizable vinyl group-containing monomers such as isoprene, chloroprene, olefins and unsaturated esters can be mentioned.

  As acrylic compounds, acrylic acid, methacrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) (Meth) acrylates such as acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate, hydroxyethyl (meth) ) Acrylate, hydroxybutyl (meth) acrylate, (meth) acrylic acid amide, (meth) acrylonitrile, (meth) acrylic acid derivatives having a functional group such as α-methyl (meth) acrylonitrile.

  Examples of the styrene compound include styrene, vinyl toluene, divinyl benzene, α-methyl styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, p-ethyl styrene, p-methoxy styrene, and the like.

  As a method for obtaining a polymer of a polymerizable vinyl group-containing monomer, any of known polymerization methods such as a radical polymerization method, an anionic polymerization method, a cationic polymerization method and the like, which are usually performed for polymerization of a polysynthetic vinyl group-containing monomer, are employed. be able to. In particular, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′- Azo compounds such as azobis (2-methyl-4-trimethoxysilylpentonitrile), 2,2′-azobis (2-methyl-4-methyldimethoxysilylpentonitrile), benzoyl peroxide, t-alkylperoxyester, A radical polymerization method carried out in the presence of a peroxide polymerization initiator such as acetyl peroxide or diisopropyl peroxycarbonate is preferred.

  In the present invention, the polymer of the polymerizable vinyl group-containing monomer is particularly preferably an acrylic polymer that is a polymer of the acrylic compound or a styrene polymer that is a polymer of the styrene compound. As a commercial item, Rohm and Haas company make, brand name: Paraloid B-66, Gifu Shellac Co., Ltd. make, brand names: RY-16, RY-17 etc. are used suitably, for example. The polymer of a polymerizable vinyl group containing monomer may be used by 1 type, or may use 2 or more types together.

  In the present invention, in order to further improve the adhesion between the anchor coat layer and the base film and to obtain a strong peel strength, a mixture of a polyester resin and a polymer of a polymerizable vinyl group-containing monomer is cured with polyisocyanate to fix the anchor film. It can also be used as a coating layer.

  Examples of the polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, 1,2-propylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, 2,4. Aliphatic diisocyanates such as 1,4-trimethylhexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,6-diisocyanate methylcaproate; 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, isophorone diisocyanate 4,4'-methylenebis (cyclohexyl isocyanate), methyl 2,4-cyclohexane diisocyanate, methyl 2, Cycloaliphatic diisocyanates such as cyclohexane diisocyanate, 1,4-bis (isocyanate methyl) cyclohexane, 1,3-bis (isocyanate methyl) cyclohexane; m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4′-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, or mixtures thereof, 4,4′-toluidine diisocyanate, dianisidine diisocyanate, 4, Aromatic diisocyanates such as 4′-diphenyl ether diisocyanate; 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, or those A mixture, ω, ω′-diisocyanate-1,4-diethylbenzene, 1,3-bis (1-isocyanate-1-methylethyl) benzene, 1,4-bis (1-isocyanate-1-methylethyl) benzene, or Aromatic aliphatic diisocyanates such as mixtures thereof; organic triisocyanates such as triphenylmethane-4,4 ′, 4 ″ -triisocyanate, 1,3,5-triisocyanatebenzene, 2,4,6-triisocyanatetoluene Polyisocyanate monomers such as organic tetraisocyanates such as 4,4′-diphenyldimethylmethane-2,2′-5,5′-tetraisocyanate; dimers, trimers, biurets derived from the above polyisocyanate monomers , Allophanate, carbon dioxide and the above polyisocyanate monomer Polyisocyanates having a 2,4,6-oxadiazine trione ring obtained from, for example, ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1 , 5-pentanediol, 3,3′-dimethylolpropane, cyclohexanedimethanol, diethylene glycol, triethylene glycol, dipropylene glycol, glycerol, trimethylolpropane, pentaerythritol, sorbitol, and other low molecular polyols having a molecular weight of less than 200 Adducts, polyester polyols having a molecular weight of 200 to 20,000, polyether ester polyols, polyester amide polyols, polycaprolactone polyols, Examples include adducts such as rerolactone polyol, acrylic polyol, polycarbonate polyol, polyhydroxyalkane, castor oil, and polyurethane polyol.

The application amount (dry state) of the anchor coat layer laminated on the base film is preferably 0.01 to 2.0 g / m ² , more preferably 0.05 to 1.0 g / m ² . When the coating amount is less than 0.01 g / m ² , the adhesion with the base film becomes poor, and sufficient peel strength may not be obtained. When the coating amount is more than 2.0 g / m ² , the peeling interface at the time of peeling becomes cohesive failure of the anchor coat layer, and there is a possibility that sufficient peeling strength cannot be obtained.

  When laminating an anchor coat layer on a base film, it is preferable to dilute a mixture of a polyester resin and a polymer of a polymerizable vinyl group-containing monomer in a solvent and use it as a varnish. The method for laminating the anchor coat layer on the base film is not particularly limited, and for example, a gravure coater, a roll coater, a bar coater or the like is used.

  The thickness of the anchor coat layer laminated on the base film is preferably 0.01 to 2.0 μm, more preferably 0.05 to 1.0 μm. When the said thickness is less than 0.01 micrometer, adhesiveness with a base film becomes bad and sufficient peel strength may not be obtained. When the thickness exceeds 2.0 μm, the peeling interface at the time of peeling becomes cohesive failure of the anchor coat layer, and there is a possibility that sufficient peeling strength cannot be obtained.

  In the laminate of the present invention, a heat seal layer is provided on the anchor coat layer. The heat seal layer in the present invention contains a styrene-butadiene copolymer resin. Examples of the styrene-butadiene copolymer resin include styrene-butadiene-styrene block copolymers and styrene-isoprene-styrene block copolymers. , Styrene-isobutylene-styrene block copolymer, styrene-ethylenebutylene-styrene block copolymer, hydrogenated product of styrene-butadiene-styrene block copolymer, hydrogenated product of styrene-isoprene-styrene block copolymer And styrene-ethylenepropylene-styrene block copolymer. Also, block copolymers composed of styrene derivatives such as α-methyl styrene, 3-methyl styrene, 4-propyl styrene and 4-cyclohexyl styrene can be used in place of styrene constituting these block copolymers. It is. Furthermore, those obtained by adding an organic acid group such as itaconic acid or maleic anhydride to these styrene-butadiene copolymer resins can also be used. Of these, styrene-ethylenebutylene-styrene block copolymers and maleic acid-modified styrene-ethylenebutylene-styrene block copolymers are preferred. As commercial products of styrene-butadiene copolymer resin, for example, trade names: Tuftec M1913, Tuftec M1943, Tuftec H1043, Tuftech H1141 and the like manufactured by Asahi Kasei Corporation are preferably used.

  In the present invention, when the styrene-butadiene copolymer resin is used as the heat seal layer, it may be used as a solid or may be adjusted to a resin solution. Examples of the solvent used for preparing the resin solution include aromatic hydrocarbons such as toluene and xylene, ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, and mixed solvents thereof.

  The heat seal layer may contain other polymers as long as the properties are not impaired. The polymer does not necessarily need to be compatible with the styrene-butadiene copolymer resin, and even when it is not compatible, the polymer can be sufficiently mixed to form a uniform film when applied onto the anchor coat layer. Anything can be used. The polymer that can be blended is preferably a styrene resin or an acrylic resin, and more preferably a styrene resin having a styrene content of 80% or more. When the styrene resin or the acrylic resin is blended at a ratio of 50 parts by mass or less with respect to 100 parts by mass of the styrene-butadiene resin, when used as a lid for a polypropylene resin container or a polystyrene resin container, It becomes easy to increase the strength.

  The heat seal layer of the present invention includes talc, polyethylene wax, synthetic wax, petroleum wax and other tackifiers, petroleum resins, rosin resins and other tackifiers, oils, fatty acid amides, fatty acid esters and other lubricants, etc. Can be blended. Among these, talc is preferable from the viewpoint of blocking prevention and adhesion performance. The blending amount of talc is preferably 50 parts by mass or less with respect to 100 parts by mass of the styrene-butadiene resin.

The application amount (dry state) of the heat seal layer laminated on the anchor coat layer is preferably 1.0 to 5.0 g / m ² , more preferably 1.0 to 3.0 g / m ² . When the coating amount is less than 1.0 g / m ² , adhesion with a polypropylene resin container or a polystyrene resin container may be insufficient. When the coating amount is more than 5.0 g / m ² , the heat seal layer is cohesive and there is a possibility that sufficient peel strength cannot be obtained.

  The method for laminating the heat seal layer on the anchor coat layer is not particularly limited, and for example, a gravure coater, a roll coater, a bar coater or the like is used.

  The thickness of the heat seal layer laminated on the anchor coat layer is preferably 1.0 to 5.0 μm, more preferably 1.0 to 3.0 μm. When the thickness is less than 1.0 μm, the adhesion with a polypropylene resin container or a polystyrene resin container may be insufficient. If the thickness is more than 5.0 μm, the heat seal layer will be cohesive and there is a possibility that sufficient peel strength cannot be obtained.

  The laminate of the present invention exhibits particularly good adhesiveness when used as a lid for polypropylene resin containers or polystyrene resin containers. When an anchor coat layer containing a mixture of a polyester resin and a polymer of a polymerizable vinyl group-containing monomer is laminated on a base film containing a polyester resin, the anchor coat layer near the base film becomes rich in the polyester resin and the distal end. The anchor coat layer becomes rich in the polymer of the polymerizable vinyl group-containing monomer. That is, in the anchor coat layer, the polyester resin and the polymer of the polymerizable vinyl group-containing monomer have a component gradient structure, and the polyester resin of the anchor coat layer strongly adheres to the base film. Next, when a heat seal layer containing a styrene-butadiene copolymer resin is laminated on the anchor coat layer, the polymer of the polymerizable vinyl group-containing monomer present on the anchor coat layer surface and the styrene-butadiene copolymer resin are compatible. And glue. By heat-sealing the laminate of the present invention to a polypropylene resin container or polystyrene resin container, the heat seal layer containing the styrene-butadiene copolymer resin is firmly bonded to the resin container. That is, even if it is a dissimilar resin such as a lid made of a laminate composed of a base film containing a polyester resin and a polypropylene resin container or a polystyrene resin container, good adhesion Can be obtained.

  Hereinafter, the present invention will be described in detail with reference to examples. In addition, the part in a following example and a comparative example means a mass part.

[Production of polyester resin solution (A) for anchor coat layer]
Charge 13.28 kg of isophthalic acid, 2.48 kg of ethylene glycol, 4.16 kg of neopentyl glycol, 4.72 kg of 1,6-hexanediol, conduct esterification reaction at 200-230 ° C. for 6 hours, and maintain a predetermined amount of water. After exiting, 2.92 kg of adipic acid was added, and the esterification reaction was further performed for 6 hours. After distilling a predetermined amount of water, the pressure was gradually reduced and the esterification reaction was carried out at 1.21 × 10 ² to 1 × 10 ³ Pa and 230 to 250 ° C. for 5 hours. The number average molecular weight was 5,000, the hydroxyl value was 23 mgKOH / g, A polyester polyol having an acid value of 0.5 mgKOH / g was obtained. Further, 0.75 kg of isophorone diisocyanate was gradually added to the total amount of this polyester polyol (NCO / OH molar ratio was 0.7), and the reaction was carried out at 150 ° C. for about 2 hours. The number average molecular weight 13,000, hydroxyl group A polyester urethane polyol having a value of 7 mgKOH / g and an acid value of 0.5 mgKOH / g was obtained.

  To 484 g of this polyester urethane polyol, 2.9 g of trimellitic anhydride and 6.2 of ethylene glycol bisanhydro trimellitate were added and reacted at 180 ° C. for about 2 hours to obtain a partially acid-modified polyol. This was adjusted with ethyl acetate to a nonvolatile content of 50% by mass to obtain a polyester resin solution (A).

[Preparation of resin solution for anchor coat layer]
Acrylic resin (B), butyral resin (C), polyisocyanate, and ethyl acetate are blended in predetermined amounts (parts by mass) shown in Table 1 with respect to 100 parts by weight of the polyester resin solution (A) obtained above. Resin solutions AC-1 to AC-8 for an anchor coat layer having a nonvolatile content of 10% by mass were prepared.

* 1: Acrylic resin (B): Rohm and Haas, trade name Paraloid B-66
* 2: Butyral resin (C): Sekisui Chemical Co., Ltd., trade name: S-Rec B BL-S
* 3: Polyisocyanate: Toyo Morton Co., Ltd., trade name CAT-RT37
(Adjustment of resin solution for heat seal layer)
* 4: Solution (non-volatile content 50% by mass)
The components shown in Table 2 were blended to prepare resin solutions HS-1 to HS-6 for a heat seal layer having a nonvolatile content of 20% by mass.

* 4: Styrene-Budadiene copolymer resin: Asahi Kasei Co., Ltd., trade name: Tuftec H1043, Styrene-ethylene butylene-styrene block copolymer * 1: Acrylic resin (B): Rohm and Haas, trade name: Paraloid B -66
* 5: Styrene resin D: manufactured by Gifu Shellac Manufacturing Co., Ltd., trade name RY-16, styrene / maleic anhydride = 90/10
* 6: Talc: Made by Nippon Mystron Co., Ltd. Brand name Mystron 850-JS
Example 1
An anchor coat layer and a heat seal layer were provided on the base film using a small gravure two-color printing machine having an original fabric width of 12.5 mm by the following method. On one surface of a 25 μm thick polyethylene terephthalate film, the resin solution AC-1 for anchor coat layer is coated with a solid plate with a line number of 175 lines and a depth of 20 μm at a drying temperature of 70 ° C. and a processing speed of 40 m / min. Then, an anchor coat layer (thickness: 0.5 μm) having a coating amount of 0.5 g / m ² after drying was provided. Next, the resin solution HS-1 for heat seal layer is applied on the anchor coat layer in-line with a solid plate having a line number of 130 and a depth of 75 μm at a drying temperature of 70 ° C. and a processing speed of 40 m / min. A laminate M-1 having a heat-sealed layer (thickness: 2.5 μm) having a coating amount of 2.5 g / m ² was obtained.

(Examples 2 to 8)
As shown in Table 3, AC-2 to AC-5 are used instead of the resin solution AC-1 for the anchor coat layer, and HS-2 to HS-5 are used instead of the resin solution HS-1 for the heat seal layer. Except that was used, the same operations as in Example 1 were performed to obtain laminates M-2 to M-8.

The laminates M-1 to M-8 obtained in Examples 1 to 8 were measured for peel strength and sealing strength by the following methods, and the results are shown in Table 3.
(Measurement method of peel strength)
The laminated body was overlapped with a polystyrene sheet (thickness: 100 μm), heat sealed at a heat sealing temperature of 200 ° C., a heat sealing pressure of 2 kg, and a toe sealing time of 1 second, and then cut into a width of 15 mm and a length of 70 mm to prepare a sample. Then, using a tensile tester (model name TE-501, manufactured by Tester Sangyo Co., Ltd., a small universal tester), it is pulled in the direction of 180 degrees at a speed of 300 mm / min, and the sample is peeled between the heat seal layer and the polystyrene sheet. The strength was measured.

(Measurement method of sealing strength)
The laminate is cut into a square of 100 mm on a side, placed on an opening of a polystyrene resin container (φ60 mm × height 50 mm) with a capacity of 100 ml filled with 90 ml of water, and a cup sealer (manufactured by Towa Techno) is used. Heat sealing was performed under the conditions of a heat sealing temperature of 200 ° C., a heat sealing pressure of 2 kg, and a heat sealing time of 1 second. Then, after standing in a constant temperature room at 20 ° C. and 65% for 1 hour, the sealing strength was measured. The sealing strength was measured using a seal tester (manufactured by Sun Scientific Co., Ltd., model name: FKT-100-J) according to JIS Z 0238: 1998-8.

(Comparative Examples 1-4)
As shown in Table 4, AC-2 and AC-6 to AC-8 were used instead of the resin solution AC-1 for the anchor coat layer, and HS-4 was used instead of the resin solution HS-1 for the heat seal layer. Alternatively, laminates M-9 to M-12 were obtained in the same manner as in Example 1 except that HS-6 was used.

The laminates M-9 to M-12 obtained in Comparative Examples 1 to 4 were measured for peel strength and sealing strength by the same method as above, and the results are shown in Table 4.

  From the results of Table 3 and Table 4, it can be seen that the laminate of the present invention has excellent peel strength and sealing strength. On the other hand, the laminate of Comparative Example 1 using the anchor coat layer resin solution AC-6 having a high mixing ratio of the acrylic resin, and the comparison using the anchor coat layer resin solution AC-7 not containing the acrylic resin. It can be seen that the laminate of Example 2 and the laminate of Comparative Example 3 using anchor coat layer resin solution AC-8 containing butyral resin in place of the acrylic resin are inferior in peel strength and sealing strength. Moreover, it turns out that the laminated body of the comparative example 4 using the resin solution HS-6 for heat seal layers containing acrylic resin instead of a styrene-butadiene-type copolymer resin is inferior in peeling strength and sealing strength.

Claims (4)

A laminate formed by sequentially laminating an anchor coat layer and a heat seal layer on one surface of a base film made of polyester resin,
The anchor coat layer includes a mixture of a polyester resin and a polymer of a polymerizable vinyl group-containing monomer, and a mixing ratio (parts by mass) of the polymer of the polyester resin / polymerizable vinyl group-containing monomer is 50/5 to 50. / 50 (in terms of solid content),
The heat seal layer contains a styrene-butadiene copolymer resin. The anchor coat layer, the laminate according to claim 1, characterized in that the mixture of the polymer of the polymerizable vinyl group-containing monomer and polyester resins are cured with polyisocyanates.   The laminate according to claim 1 or 2, wherein the heat seal layer contains at least one selected from a styrene resin, an acrylic resin, and talc. The lid | cover material of the container made from a polypropylene resin or a polystyrene resin which uses the laminated body as described in any one of Claims 1-3.