JP6405917B2 - Heat-sealing lid material with excellent adhesive strength - Google Patents

Description

The present invention relates to a heat sealing lid material characterized by laminating a base material layer having a gas barrier layer, an anchor coating agent layer, and a thermal adhesive layer sequentially. In particular, it is a heat sealing lid material used for pudding, yogurt, jelly, syrup, etc., and is preferably used for articles such as quadruple pot packs, triple pot packs, and potion packs that are heat sealed in a synthetic resin container. .

For example, a packaging material for a quadruple pot pack for yogurt is a heat sealing lid material in which an anchor coating agent layer and a thermal adhesive layer are sequentially laminated on a polyester film having a metal vapor deposition layer, and a synthetic resin container is made of polystyrene. Resin containers are generally used, and it is required to completely seal the heat-sealing lid material and the synthetic resin container for the preservation of contents (long-term storage) and long-distance distribution. It is used a lot.

Here, the ring seal, which is a means for sealing the heat-sealing lid material and the synthetic resin container, is sealed with a hot plate having ring-shaped protrusions, and the ring-shaped groove together with the lid on the flange portion of the synthetic resin container. In general, a thermal adhesive made of a carboxylated polypropylene-based thermoplastic modified resin or an acrylic resin with a vinyl chloride resin is used for the thermal adhesive layer of these heat sealing lid materials.

However, at the time of processing the package, there is a step of sealing the heat-sealing lid material in a synthetic resin container filled with the contents, but when the lid material or synthetic resin container, the contents are replenished to the machine, A small-time production line may be stopped. At that time, under the heated plate having the heated ring-shaped protrusion, the lid material before being heat sealed or the heat sealed package in the vicinity is heated, and then the ring in the production line resumed. Sealing was not possible, or even if it was possible, it was not possible to obtain a sufficient sealing performance. In other words, the adhesive strength deteriorates or partially peels due to poor chemical interaction and heat cohesion with synthetic resin containers made of decarboxylated polypropylene-based thermoplastic modified resins and acrylic resins. Has occurred.

In addition, there is a heat sealing lid material in which the thermal adhesive layer is made of acrylic / polyester / polyolefin graft polymer, and a package using these heat sealing lid materials has good adhesive strength at room temperature.

However, in the heat sealing lid material characterized in that the thermal adhesive layer has an acrylic / polyester / polyolefin graft polymer, after the exhaust time (5-10 minutes) for forming the coating film of the thermal adhesive layer, the air A baking process for about 15 seconds at 180 ° C. in a circulating furnace is required, and the productivity is poor. Further, the graft polymer is provided as a dispersion in a solution, and when the coating process is insufficient without performing the baking step, the thermal adhesive layer is peeled off when the thermal adhesive layer is rubbed strongly. . That is, there is a problem that the friction resistance is insufficient, and there is a fatal defect when used for a lid material that comes into contact with food.

Further, when the content is food, for example, yogurt or pudding, there is a process in which the heat sealing lid member having the heat adhesive layer is sterilized by ultraviolet irradiation. However, in the above-mentioned thermal adhesive used for the conventional thermal adhesive layer, ring sealing cannot be performed after irradiation with ultraviolet rays, or even if it can be performed, a sufficient sealability cannot be obtained. That is, the graft polymer, devinyl chloride resin, carboxylated polypropylene thermoplastic modified resin, and acrylic resin were destroyed by ultraviolet rays, the structure was destroyed, the adhesive strength was deteriorated, or partial peeling occurred.

JP 2000-007032 A JP 2004-115089 A Special table 2009-528408 gazette

The present invention has been made to solve the above problems, and its purpose is to provide a thermal adhesive layer with good productivity while preventing deterioration of adhesive strength due to heat and ultraviolet irradiation in the production process. The object is to provide a laminated heat sealing lid material.

Furthermore, another object of the present invention is to provide a heat sealing lid material having a thermal adhesive layer with good friction resistance without requiring a special baking step when laminating the thermal adhesive layer. It is in.

That is, the present invention provides a heat sealing lid material in which a base material layer having a gas barrier layer, an anchor coating agent layer formed by applying an anchor coating agent, and a thermal adhesive layer formed by applying a thermal adhesive are sequentially laminated. And it is related with the heat sealing lid | cover material characterized by being the following (1) and (2).
(1) The anchor coat agent contains a polyurethane resin (A) and a vinyl chloride / vinyl acetate copolymer resin (B).
(2) The thermal adhesive contains a polyurethane resin (A) and an acrylic / polyester / polyolefin graft polymer (C).

The present invention also relates to a heat sealing lid material, wherein the thermal adhesive further contains an acrylic resin (D) other than the acrylic / polyester / polyolefin graft polymer (C).

The present invention also relates to a heat sealing lid material in which a base material layer having a gas barrier layer, an anchor coating agent layer formed by applying an anchor coating agent, and a thermal adhesive layer formed by applying a thermal adhesive are sequentially laminated. And it is related with the heat sealing lid | cover material characterized by following (1) and (2).
(1) 40 to 70 parts by weight of the polyurethane resin (A) and 30 to 60 parts by weight of the vinyl chloride / vinyl acetate copolymer resin (B) in 100 parts by weight of the solid content of the anchor coating agent.
(2) 15 to 35 parts by weight of the polyurethane resin (A), 15 to 35 parts by weight of the acrylic / polyester / polyolefin graft polymer (C), and 40 to 40 parts of the acrylic resin (D) in 100 parts by weight of the solid content of the thermal adhesive. 60 parts by weight.

The present invention also relates to a heat sealing lid material, wherein the gas barrier layer is a metal vapor deposition layer.

The present invention also relates to a packaging body, wherein the packaging body includes a heat sealing lid material and a synthetic resin container, and an opening of the synthetic resin container is heat sealed with a heat sealing lid material. .

Anchor coat agent containing polyurethane resin (A) and vinyl chloride / vinyl acetate copolymer resin (B) in the anchor coating agent layer, and polyurethane resin (A) and acrylic / polyester / polyolefin graft in the thermal adhesive layer By using a heat-sealing lid material characterized by laminating a thermal adhesive containing the polymer (C), it is possible to improve the adhesive strength after hot or ultraviolet irradiation.

Furthermore, since the thermal adhesive layer of the present invention forms a coating film, there is no need for a baking step and productivity can be improved.

Therefore, according to the present invention, a highly hygienic heat sealing lid material in which a thermal adhesive layer having good productivity is laminated while preventing adhesive strength due to hot or ultraviolet irradiation in the production process. Can be provided.

The heat sealing lid material 1 is provided with an anchor coating agent layer 3 and a thermal adhesive layer 4 on one surface of a base material layer 2 and a gas barrier layer 5 on the other surface. The heat sealing lid material 2 may be laminated with a paper layer 7 or a protective film layer 8 via an adhesive layer 6 on the side where the gas barrier layer 5 is provided on the other surface of the base material layer 2.

Embodiments of the present invention will be described below with reference to the accompanying drawings. As shown in FIG. 1, the heat sealing lid material 1 is provided with an anchor coating agent layer 3 and a thermal adhesive layer 4 on one surface of a base material layer 2 and a gas barrier layer 5 on the other surface.

As the base material layer 2, a single body or a composite of a synthetic resin film such as polyester, polypropylene, polyethylene, nylon, etc. is used, and its thickness is about 6 to 50 μm from the viewpoint of cost, moldability, flexibility, and film strength. The thickness is preferably 9 to 40 μm.

As the gas barrier layer 5, at least one selected from a metal or a metal vapor deposition layer can be used. For the metal vapor deposition layer, Al, Ag, Ti, Sn, Al2O3 (alumina), SiO2 (silica), SnO, TiO2 or the like can be used. A preferred thickness is about 300 to 1200 angstroms from the viewpoints of cost, moisture permeability resistance, and oxygen permeability resistance.

A commercially available resin film in which the gas barrier layer 5 is vapor-deposited in advance can be used for the base material layer 2. For example, aluminum vapor-deposited 12 μm polyester film (manufactured by Oike Industry Co., Ltd., aluminum vapor-deposited layer is 600 Å), silica-deposited 12 μm polyester film (manufactured by Oike Industry Co., Ltd., silica-deposited layer is 700 angstroms), alumina-deposited 12 μm polyester film (Toyo Metallizing Co., Ltd., alumina vapor deposition layer is 1000 angstroms), silica vapor deposition 12 μm polyester film (Mitsubishi Chemical Kojin Pax Co., Ltd. high barrier <tech barrier>), etc. can be used.

If necessary, as shown in FIG. 2, the heat sealing lid material 2 is formed by laminating a paper layer 7 or a protective film layer 8 on the gas barrier layer 5 side of the outer surface of the base material layer 2 with an adhesive layer 6 interposed therebetween. Also good.

For the paper layer 7, pure white roll paper, kraft paper, high quality paper, imitation paper, western paper, Japanese paper, various coated papers and the like can be used, and among these, the use of single-sided coated paper is most preferable. Various types of printing, an overcoat layer of about 1 μm, and the like may be applied to the outer surface of the paper layer 7 (the outermost surface of the lid member). Of course, there is no problem even if printing is performed on both sides of the paper layer. For example, “Ryuo Coat A” (manufactured by Nagoya Pulp Co., Ltd.) can be used as the single-side coated paper. The thickness of the paper is suitably from 30 to 150 μm, preferably from about 50 to 130 μm, from the viewpoint of heat conduction during heat sealing and curling prevention. Moreover, it is preferable that the thickness of the paper layer 7 is at least one half of the thickness of the entire lid member 2, so that curling of the lid member 2 can be prevented and moderate to the lid member 2. It has the advantages of providing high rigidity, reducing accidents during sheet feeding, and providing dead hold (shape retention after opening) when opened.

As the protective film layer 8, a single body or a composite of a synthetic resin film such as polyester, polypropylene, polyethylene, nylon, etc. is used, and its thickness is about 6 to 50 μm from the viewpoint of cost, moldability, flexibility, and film strength. The thickness is preferably 9 to 40 μm.

Moreover, printing can be performed on an arbitrary layer. In this case, Eco Color F Series (both manufactured by Toyo Ink Co., Ltd.) can be used for the paper layer 7, and Fine Star Series (both manufactured by Toyo Ink Co., Ltd.) can be used for the protective film layer 8. There is no particular limitation on the thickness, but it is about 0.1 μm to 5 μm.

The adhesive layer 6 is not particularly limited, but is preferably laminated by a dry laminating method using a dry laminating adhesive. As the adhesive for dry lamination, known ones can be adopted, and for example, it is preferable to use a dry laminate adhesive such as polyester urethane type or polyester type, from the viewpoint of maintaining sufficient adhesive strength and economical efficiency. Is about 0.5 to 10 g / m ² .

On the anchor coating agent layer 3, an anchor coating agent containing a polyurethane resin (A) and a vinyl chloride / vinyl acetate copolymer resin (B) is laminated. Anchor coating agent, after drying the resin solids 0.5 g / m ² to 3.0 g / m ² approximately, may be applied to the substrate layer 2. The anchor coating agent can be produced by dissolving the polyurethane resin (A) and the vinyl chloride / vinyl acetate copolymer resin (B) in an organic solvent by a known method.

The polyurethane resin (A) is synthesized by reacting the polymer polyol and diisocyanate at a temperature of 10 to 150 ° C. using an inert solvent for the isocyanate group, if necessary, and using a urethanization catalyst if necessary. To produce a polyurethane resin by reacting a chain extender and a terminal terminator with the prepolymer, or a polymer polyol, diisocyanate and chain extender. Can be produced by a known method such as a one-shot method in which a polyurethane resin is obtained by reacting in a single step.

Examples of the polymer polyol include polyester polyol, polyether polyol, and acrylic polyol. In the present invention, it is desirable to use one or more of polyester polyol and polyether polyol.

The polyester polyol is a polyester polyol containing a hydroxyl group at the terminal and / or side chain, and is obtained by dehydration condensation or polymerization of a hydroxyl group-containing compound such as glycol or polyol and a polyvalent carboxylic acid or an anhydride thereof. can get. In the present invention, more specifically, a polyester diol composed of a compound containing two hydroxyl groups and a divalent carboxylic acid is preferred.

Examples of the hydroxyl group-containing compound used for the synthesis of the polyester polyol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, pentanediol, and 2-methyl-1,3-propane. Diol, neopentyl glycol, 3-methyl-1,5-pentanediol, hexanediol, octanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol, 1,4-butynediol, 2 , 2,4-trimethyl-1,3-pentanediol, 1,4-cyclohexanedimethanol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, diethylene glycol, triethylene Glycol, polypropylene glycol, dipropylene glycol Call, etc., and the like. Moreover, the low molecular polyol which has 3 or more of hydroxyl groups, such as glycerol, a trimethylol propane, a trimethylol ethane, 1,2, 6-hexane triol, 1,2, 4- butane triol, sorbitol, a penta esitol, is also mentioned. . Of these, 3-methyl-1,5-pentanediol is preferred from the standpoint of blocking resistance and film strength.

In addition, as a high molecular weight hydroxyl group-containing compound, saturated or unsaturated low molecular weight diols, polymers such as ethylene oxide, propylene oxide, and tetrahydrofuran or copolymer polyether diols are also used as raw materials for polyester diols. can do.

Furthermore, it is preferable to use a hydroxyl group-containing compound having an alkyl side chain as a monomer for the polyester polyol. By using the polyester polyol, the crystallinity of the polyurethane resin is greatly reduced, and the alkyl side chain is hydrocarbon and hydrophobic, so that the adhesion to the polyolefin film is improved. Furthermore, hydrolysis resistance improves compared with the case where a hydroxyl-group containing compound does not have an alkyl side chain.

Polycarboxylic acid monomers used for the synthesis of polyester diol include adipic acid, phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, speric acid, Examples thereof include polycarboxylic acids such as azelaic acid, sebacic acid, trimellitic acid and pyromellitic acid, and anhydrides thereof. Of these, adipic acid is preferably used from the viewpoint of solubility in a non-toluene solvent, and more preferably 50% by weight or more based on the total amount of the polyvalent carboxylic acid monomer.

The number average molecular weight of the polyester diol used in the polyurethane resin (A) is appropriately determined in consideration of the solubility, drying property, blocking resistance and the like of the resulting polyurethane resin, and is usually 700 to 100,000, solubility and drying property, From the point of blocking resistance, it is preferably within the range of 1000 to 6000.

The acid value of the polyester diol is preferably 1.0 mgKOH / g or less, and more preferably 0.5 mgKOH / g or less from the viewpoint of the temporal stability of the ink.

Since polyester diol is more excellent in blocking resistance than other polymer polyols, it is preferable to use 50% by weight or more of the total amount of polyester polyols in the total amount of polymer polyols.

It is also preferable to use a polyether polyol as the polymer polyol. For example, polyethylene glycol, polypropylene glycol, polytrimethylene glycol, polytetramethylene glycol and the like can be mentioned. Since these have excellent solubility in alcohol and can impart another solvent solubility to the polyester-based polyurethane, they are preferably used in combination in many applications. In order to develop these characteristics and not lower the water resistance and the like, the polyether polyol molecular weight is preferably 700 to 3000, and preferably 50% by weight or less in the total amount of the polymer polyol. Among these, polypropylene glycol is preferable from the viewpoint of solubility in a non-toluene solvent.

Examples of the diisocyanate used for the synthesis of the polyurethane resin (A) include various known aromatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates that are generally used in the production of polyurethane resins. For example, 1,5-naphthylene diisocyanate, 4,4′-diphenylmethane diisocyanate (MDI), 4,4′-diphenyldimethylmethane diisocyanate, 4,4′-dibenzyl isocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1 , 3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, Cyclohexane-1,4-diisocyanate, xylylene diisocyanate, isophorone diisocyanate Nate, dimethylene diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, 1,3-bis (isocyanatemethyl) cyclohexane, methylcyclohexane diisocyanate, norbornane diisocyanate, m-tetramethylxylylene diisocyanate, bis-chloromethyl-diphenylmethane-diisocyanate 2,6-diisocyanate-benzyl chloride, dimerized isocyanate obtained by converting a carboxyl group of dimer acid into an isocyanate group, and the like. These diisocyanate compounds can be used alone or in admixture of two or more. Among these, isophorone diisocyanate is preferable from the viewpoint of solubility in a non-toluene solvent and film strength.

For the synthesis of the polyurethane resin (A), a chain extender may be used. For example, in addition to 2-butyl-2-ethyl-1,3-propanediol, the saturated or unsaturated low molecular polyols, ethylenediamine, In addition to propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine, dicyclohexylmethane-4,4'-diamine, 2-hydroxyethylethylenediamine, 2-hydroxyethylpropyldiamine, 2-hydroxyethylpropylenediamine, di 2-hydroxyethylethylenediamine, di-2-hydroxyethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, di-2-hydroxypropylethylenediamine, di- - amines having a hydroxyl group in the molecule such as hydroxypropyl ethylenediamine can also be used. These chain extenders can be used alone or in admixture of two or more.

A monovalent active hydrogen compound can also be used as a terminal terminator for the purpose of terminating the reaction. Examples of such compounds include compounds having primary and secondary amino groups, dialkylamines such as di-n-butylamine, amino alcohols having a hydroxyl group, and alcohols such as ethanol and isopropyl alcohol. Furthermore, amino acids such as glycine and L-alanine can be used as a reaction terminator, particularly when it is desired to introduce a carboxyl group into the polyurethane resin. Among these, amino alcohols having primary and secondary amino groups need to be controlled so as to react only with amino groups while avoiding reaction at high temperature when used as a terminal terminator. These end terminators can be used alone or in admixture of two or more. Here, when an amino group is used as the chain extender, it reacts with an isocyanate group to form a urea bond, so that the resulting resin is a polyurethane / urea resin. In the present invention, these resins are also polyurethane resins ( A).

Furthermore, in the present invention, a water-soluble polyurethane resin can also be used. In the case of synthesizing a water-soluble polyurethane resin, an anionic group-containing compound having an active hydrogen group, a cationic group-containing compound, a nonionic group-containing compound, or the like is used in addition to the polymer polyol and diisocyanate. In the present invention, from the viewpoint of solubility of the water-soluble polyurethane resin, physical properties of the coating film, etc., it is preferable to use an anionic group-containing compound and use a nonionic group-containing compound in combination as necessary.

As an anionic group-containing compound having an active hydrogen group, a compound having a carboxyl group is generally known, and 2,2′-dimethylolpropionic acid, 2,2′-dimethylolbutanoic acid, 2,2′- Dimethylol butanoic acid, dimethylol alkanoic acid such as 2,2'-dimethylol valeric acid, glutamine, asparagine, lysine, diaminopropionic acid, ornithine, diaminobenzoic acid, diamine type amino acids such as diaminobenzenesulfonic acid, glycine, alanine, glutamic acid Monoamine type amino acids such as taurine, aspartic acid, aminobutyric acid, valine, aminocaproic acid, aminobenzoic acid, aminoisophthalic acid and sulfamic acid.

The anionic group incorporated in the polyurethane resin forms a salt by neutralization and dissolves in water. Examples of the neutralizing agent used in this case include ammonia, monoethylamine, diethylamine, trimethylamine, triethylamine, triisopropylamine, tributylamine, triethanolamine, methyldiethanolamine, and monoethanolamine. Ammonia is preferred because it does not easily remain in the film and does not impair the physical properties of the coating film.

Examples of the cationic group-containing compound having an active hydrogen group include compounds having an amino group, an ammonium base, a sulfonium base and the like.

As the nonionic group-containing compound, it is preferable to use an ethylene oxide repeating unit-containing compound such as ethylene glycol or polyethylene glycol. Since nonionic groups are poorly soluble in water, it is difficult to dissolve a polyurethane resin in water only with nonionic groups. However, in order to adjust the stability of the resin and the suitability of the coating film, the above anions / cations may be used. It can be used in combination with a functional group-containing compound.

In the production of the prepolymer which is an intermediate of the polyurethane resin, the amount of the polymer polyol and the diisocyanate is the ratio of the number of moles of the isocyanate group of the diisocyanate and the total number of moles of the diol containing the polymer polyol and the hydroxyl group of the polyol. It is preferable that a certain NCO / OH ratio is in the range of 1.1 to 3. When this ratio is smaller than 1.1, the reaction with the chain extender becomes insufficient, so that the adhesive strength is lowered, and when it is larger than 3, the solubility of the resulting prepolymer tends to be lowered. .

Furthermore, a catalyst can also be used for this polyurethane-ized reaction. Examples of catalysts that can be used include tertiary amine catalysts such as triethylamine and dimethylaniline; metal catalysts such as tin and zinc. These catalysts are used in the range of 0.001 to 1 mol% with respect to the hydroxyl group-containing compound including the polymer polyol.

The above-obtained prepolymer having an isocyanate group at the terminal and a chain extender such as diol, diamine, or triol are reacted at 10 to 80 ° C. to obtain a polyurethane resin containing an active hydrogen group at the terminal.

When using an end-stopper, the end-stopper and chain extender may be used together to carry out a chain extension reaction. Thus, an end termination reaction may be performed. On the other hand, the molecular weight can be controlled without using a terminal terminator, but in this case, a method of adding a prepolymer to a solution containing a chain extender is preferable in terms of reaction control.

End terminators are used to control molecular weight. As the amount used increases, the molecular weight of the resulting polyurethane resin decreases. This varies depending on the reactivity of the chain extender and end terminator to the prepolymer, but in general, the ratio of the number of moles of amino groups and hydroxyl groups of the chain extender to the number of moles of amino groups and hydroxyl groups of the end terminator is The range of 0.5-5 is preferable from the point of dry lamination suitability and adhesive force.

The ratio of the total number of moles of amino groups and hydroxyl groups of the chain extender and terminal terminator to the equivalent of isocyanate groups in the prepolymer is in the range of 1.1 to 3, preferably 1.5 to 2.0. React. By setting the ratio within this range, the odor tends not to remain.

The polyurethane resin (A) preferably has a weight average molecular weight of 15000 to 100,000 from the viewpoint of blocking resistance and solubility.

  The amine value of the polyurethane resin (A) is preferably 0.5 to 14.0 mgKOH / g, and the amine value is more preferably 5.0 to 10.0 mgKOH / g. Within the above range, the adhesion to the polyester film can be ensured, and the ink stability when an isocyanate curing agent is added and the balance between the hardness of the resin and the thermal adhesiveness are favorable, which is preferable.

Solvents used for the polyurethane resin (A) include ester solvents such as ethyl acetate, n-propyl acetate, isopropyl acetate, isobutyl acetate, propylene glycol monoethyl ether acetate, methanol, ethanol, n-propanol, isopropanol, n -Alcohol solvents such as butanol, aromatic solvents such as benzene, toluene and xylene, ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone, and known solvents such as water can be used alone or in combination.

The vinyl chloride / vinyl acetate copolymer resin (B) used for the anchor coating agent is obtained by copolymerizing a vinyl chloride monomer and a vinyl acetate monomer. The vinyl chloride / vinyl acetate copolymer having a hydroxyl group can further use vinyl alcohol in the copolymerization or saponify a part of vinyl acetate. In the vinyl chloride / vinyl acetate copolymer having a hydroxyl group, the properties of the resin film and the resin dissolution behavior are determined by the monomer ratio of vinyl chloride, vinyl acetate and vinyl alcohol. In other words, vinyl chloride gives the toughness and hardness of the resin film, vinyl acetate gives adhesion and flexibility, and vinyl alcohol has good solubility in polar solvents and compatibility with polyurethane resin, so it can be thermally bonded. The adhesive strength at the time becomes good, and when an isocyanate curing agent is added, the adhesive strength to the substrate is improved. In the present invention, the vinyl chloride / vinyl acetate copolymer preferably has a hydroxyl group.

  Solvents used for the vinyl chloride / vinyl acetate copolymer resin (B) include ester solvents such as ethyl acetate, n-propyl acetate, isopropyl acetate, isobutyl acetate, propylene glycol monoethyl ether acetate, methanol, ethanol, Alcohol solvents such as n-propanol, isopropanol and n-butanol, aromatic solvents such as benzene, toluene and xylene, ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone, and known solvents such as water alone or Multiple can be used.

The anchor coating agent has 40 to 70 parts by weight of the polyurethane resin (A) and 30 to 60 parts by weight of the vinyl chloride / vinyl acetate copolymer resin (B) with respect to 100 parts by weight of the solid content of the anchor coating agent. Is preferred.
When the polyurethane resin (A) is in the range of 40 to 70 parts by weight, the adhesive strength at normal temperature is good, and the vinyl chloride / vinyl acetate copolymer resin (B) is in the range of 30 to 60 parts by weight. And, the hot bond strength is improved.

Examples of the solvent used for the anchor coating agent include the solvents described in the polyurethane resin (A) and the vinyl chloride / vinyl acetate copolymer resin (B).

The dilution solvent used during printing in the anchor coating agent is used in the aforementioned anchor coating agent in consideration of the solubility and drying properties of the materials used in order to adjust the viscosity and control the printing effect and printed matter density. The solvent can be selected as appropriate.

Furthermore, various resin can be used together for an anchor coating agent according to a use or a base material. Examples of resins used include acrylic resin, nitrocellulose resin, chlorinated polypropylene resin, vinyl acetate resin, polyamide resin, polyester resin, alkyd resin, polyvinyl chloride resin, rosin resin, rosin modified maleic acid resin, terpene resin And phenol-modified terpene resin, ketone resin, cyclized rubber, chlorinated rubber, butyral, petroleum resin, and modified resins thereof. These resins can be used alone or in admixture of two or more, and the content thereof is preferably 5 to 25% by weight with respect to the total weight of the anchor coating agent.

The anchor coating agent can be printed by a known printing method such as gravure printing, flexographic printing, ink jet printing, and coater coating. Gravure printing is preferred.

The anchor coating agent can be used in combination with an isocyanate curing agent depending on the application, base material and required physical properties. As an example of the isocyanate curing agent to be used, diisocyanate includes hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), and xylylene diisocyanate (XDI). Examples of the modified polyisocyanate include adduct type, bifunctional prepolymer type, and biuret type. These curing agents can be used alone or in admixture of two or more, and preferably 1 to 10 parts by weight in 100 parts by weight of the above-mentioned anchor coating agent. When it is larger than 10 parts by weight, it is difficult to ensure blocking resistance due to a decrease in drying property of the printed matter. In addition, the design print layer is excessively cured and the thermal adhesion of the thermal adhesive layer is hindered. If the amount is less than 1 part by weight, the cured film cannot be sufficiently cured on the printed matter, and thus good adhesive strength cannot be obtained.

Next, a thermal adhesive containing a polyurethane resin (A) and an acrylic / polyester / polyolefin graft polymer (C) is laminated on the thermal adhesive layer 4.

The application amount of the thermal adhesive is preferably 1.5 to 15 g / m ² from the viewpoints of adhesiveness, workability, and economy.

The polyurethane resin (A) used for the above-mentioned anchor coat agent can be used as the polyurethane resin (A) used for the thermal adhesive.

The acrylic / polyester / polyolefin graft polymer (C) used for the thermal adhesive has particularly strong cohesive strength of the acrylic resin component, and can maintain the adhesive strength at room temperature and the hot adhesive strength. Further, since the grafted polyester resin and polyolefin resin component are firmly bonded to the anchor coating agent layer, it is possible to further improve the bonding strength at normal temperature and the bonding strength between hot. As the acrylic / polyester / polyolefin graft polymer (C), known ones can be adopted. Specifically, the weight average molecular weight is preferably 20,000 to 200,000 in view of ensuring the cohesive strength of the resin.
In the specification, acrylic / polyester / polyolefin graft polymer (C) represents an acrylic, polyester, and polyolefin graft copolymer resin.

The acrylic / polyester / polyolefin graft polymer (C) is generally produced by grafting a monomer that produces an acrylic polymer to a polyester polymer and a polyolefin polymer under suitable reaction conditions. The acrylic / polyester / polyolefin graft polymer (C) is a graft polymer having a polyester chain, a polyolefin chain, and a poly (meth) acrylate chain.

The acrylic / polyester / polyolefin graft polymer (C) is produced in a suitable solvent inert to the polymerization conditions and having a boiling point above the normal synthesis temperature. Solvents include, for example, acetate esters such as ethyl acetate, propyl acetate or butyl acetate, aliphatic solvents such as isooctane, cycloaliphatic solvents such as cyclohexane and carbonyl solvents such as butanone.

This acrylic / polyester / polyolefin graft polymer (C) can be produced by adding one or several kinds of a mixture in which a monomer for forming an acrylic polymer is added to a solvent in which a polyester polymer and a polyolefin polymer described below are dissolved. It can be obtained by polymerizing at a temperature of −10 ° C. to 100 ° C. within a period of usually 4 to 8 hours under the addition of a seed peroxide radical initiator. For example, peresters such as tert-butyl peroctoate are used as radical initiators. This initiator concentration is generally 0.1% to 3% by weight based on the monomer.

As a component for forming the polyester polymer used when the acrylic / polyester / polyolefin graft polymer (C) is produced, a polyester polymer whose monomer structural unit is characteristic of itaconic acid is used. This polyester polymer has a linear or branched structure and has an OH value of -5 to 150 mg KOH / g, preferably 10 to 50 mg KOH / g, preferably 5 mg KOH / g or less, more preferably 2 mg KOH / g or less. It is characterized by an acid number of 700 to 25000 g / mol, preferably a number average molecular weight of 2000 to 12000 g / mol.

The content of itaconic acid in the polyester polymer is in the range of 0.1 mol% to 20 mol%, preferably 1 mol% to 10 mol%, more preferably 2 mol% to 8 mol%, based on the total amount of polycarboxylic acid used. Is in. Otherwise, the type of polycarboxylic acid used for the polyester polymer according to the invention is arbitrary per se. Aliphatic and / or cycloaliphatic and / or aromatic carboxylic acids can be included. A polycarboxylic acid is preferably a compound having one or more, more preferably two or more carboxyl groups and, unlike the general definition, is also a monocarboxylic acid in a special embodiment.

Examples of the aliphatic polycarboxylic acid having a short chain are succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, tetradecanedioic acid, and octadecanedioic acid. An example of a cycloaliphatic polycarboxylic acid is an isomer of cyclohexanedicarboxylic acid. Examples of aromatic polycarboxylic acids are isomers of benzenedicarboxylic acid and trimellitic acid. If appropriate, instead of the free polycarboxylic acids, it is also possible to use their esterifiable derivatives, for example the corresponding lower alkyl esters or cyclic anhydrides. The type of polyol used for the polyester polymer is arbitrary. Aliphatic and / or cycloaliphatic and / or aromatic polyols can be included. A polyol is preferably a compound having one or more, more preferably two or more hydroxyl groups and, unlike the general definition, is also a monohydroxy compound in a particular embodiment.

Examples of polyols are ethylene glycol, propanediol-1,2, propanediol-1,3, butanediol-1,4, pentanediol-1,5, hexanediol-1,6, nonanediol-1,9, Dodecanediol-1,12, neopentyl glycol, butylethylpropanediol-1,3, methylpropanediol-1,3, methylpentanediol, cyclohexanedimethanol, trimethylolpropane, pentaerythrol and mixtures thereof.

An aromatic polyol is a reaction product of an aromatic polyhydroxy compound such as hydroquinone, bisphenol A, bisphenol F, dihydroxynaphthalene and the like and an epoxide such as ethylene oxide or propylene oxide. Polyols can also include ether diols, ie oligomers or polymers based on, for example, ethylene glycol, propylene glycol or butanediol 1,4. In particular, a linear aliphatic glycol is preferable.

In addition to polyols and dicarboxylic acids, lactones can also be used.

From the total amount of polycarboxylic acid used, 0. Polyester polymers having an itaconic acid content of 1 mol% to 20 mol%, preferably 1 mol% to 10 mol%, more preferably 2 mol% to 8 mol% are produced by techniques established for (poly) condensation reactions.

In each pre-reaction mixture for producing the acrylic / polyester / polyolefin graft polymer (C), the amount of polyester polymer used before the grafting reaction is 10% to 90% by weight, preferably 25% by weight. It is -75 mass%, Most preferably, it is 40 mass%-60 mass%.

Examples of monomers for forming acrylic polymers that can be used in acrylic / polyester / polyolefin graft polymers (C) include standard methacrylates such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, and isobutyl methacrylate. In addition, acrylic acid or methacrylic acid may be mentioned. Among acrylic polymers, styrene, α-methylstyrene, vinyl chloride, vinyl acetate, vinyl stearate, vinyl methyl ketone, vinyl isobutyl ether, allyl acetate, allyl chloride, allyl isobutyl ether, allyl methyl ketone, maleic acid Dibutyl, dilauryl maleate, dibutyl itaconate may be contained.

The amount of monomer that forms the acrylic polymer used in each pre-reaction mixture for the preparation of the acrylic / polyester / polyolefin graft polymer (C) is 10% to 90% by weight, preferably 25% to It is 75 mass%, More preferably, it is 40 mass%-60 mass%.

The polyolefin polymers to be used are known per se. This is primarily a polymer composed of ethylene-, propylene-, butylene- and / or other α-olefins having 5-20 C atoms, which is already recommended as a sealable material. ing. This molecular weight is generally 10,000 to 300,000, preferably 50,000 to 150,000. The types of olefin copolymers to be applied are described, for example, in DE-OS1644941, DE-OS1769834, DE-OS1939037, DE-OS1963039 and DE-OS2059981 in German Patent Publications.

For example, Buna® 6170 (manufacturer: Lanxess AG) can be used as the polyolefin polymer.

Ethylene-propylene-copolymers can be used with particular advantage; terpolymers with the addition of known third components such as ethylidene-norbornene (see Macromolecular Reviews, Vol. 101975) are also possible, however, This must take into account the tendency to crosslink during the aging process. This distribution can in this case be sufficiently statistical, but it is also possible to use sequence polymers with advantageously ethylene blocks. The proportion of monomeric ethylene-propylene is in this case variable within a predetermined range, which can be delimited by about 95% for ethylene and about 95% for propylene as upper limits.

The amount of polyolefin polymer used for producing the acrylic / polyester / polyolefin graft polymer (C) in the present invention is 5% by mass to 60% by mass, preferably 20% by mass to 55% by mass, particularly preferably 25% by mass. It is -55 mass%.

In addition to the polyurethane resin (A) and acrylic / polyester / polyolefin graft polymer (C), various resins are used in combination with the thermal adhesive applied to the thermal adhesive layer 4 depending on the application, base material, and required physical properties. can do. Examples thereof include acrylic resins (D) other than acrylic / polyester / polyolefin graft polymer (C), polyester resins, alkyd resins, resins having a styrene component, and the like. These resins can be used alone or in admixture of two or more. Specific examples of the resin having a styrene component include styrene-ethylene / butylene-styrene block polymer (SEBS), styrene / butadiene block copolymer (SB: diblock), and (SBSS: tri Block), styrene / isoprene block copolymer (SI: diblock), (SISS: triblock) or styrene / butadiene-isoprene block copolymer (SB-I: diblock), (SB / IB: triblock), hydrogenated products thereof (for example, hydrogenated styrene / butadiene / styrene block copolymer (SBS), hydrogenated styrene / isoprene / styrene block copolymer) Product (SEPS)), or these carboxylic acid modified products. A part of styrene constituting the styrene block may be replaced with an aromatic vinyl compound such as α-methylstyrene. Other examples include styrene / acrylic copolymers and styrene / resin copolymers, styrene / rubber copolymer resins, and modified resins thereof.

In particular, the acrylic resin (D) is preferably used for improving the adhesive strength in the thermal adhesive applied to the thermal adhesive layer 4. The acrylic resin has a strong cohesive force, and can maintain the adhesive strength at normal temperature and the hot adhesive strength. In addition, it is easy to adopt because of its low cost. A well-known thing can be employ | adopted for an acrylic resin (D). The weight average molecular weight is preferably 20,000 to 300,000 from the viewpoint of solubility in a solvent and cohesive strength of the resin. Moreover, it is preferable that the glass transition temperature is 10 ° C. to 200 ° C. from the viewpoint of securing the hot adhesive strength. The acid value is preferably from 0 to 100 from the viewpoint of the handleability of the ink. Specifically, acrylic-modified urethane, blend resin of acrylic (methacrylic acid) and vinyl butyral, polyacrylic acid ester, polymethacrylic acid ester, polymethyl methacrylate, ethylene / acrylic acid copolymer, ethylene / methacrylic acid copolymer , Ethylene / methyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / methyl methacrylate copolymer, ionomer and the like can be used, and two kinds of resins may be used in combination. .

The thermal adhesive is 15 to 35 parts by weight of polyurethane resin (A), 15 to 35 parts by weight of acrylic / polyester / polyolefin graft polymer (C), and acrylic resin (D) with respect to 100 parts by weight of the solid content of the thermal adhesive. ) Is preferably 40 to 60 parts by weight.
When the polyurethane resin (A) is in the range of 15 to 35 parts by weight, the adhesive strength after ultraviolet irradiation is good, and the acrylic / polyester / polyolefin graft polymer (C) is in the range of 15 to 35 parts by weight. The friction resistance is good. Furthermore, the adhesive strength in normal temperature is preferable in it being 40-60 weight part of acrylic resins (D).

The thermal adhesive agent can be printed by a known printing method such as gravure printing, flexographic printing, ink jet printing, coater coating, or the like. Gravure printing is preferred.

In the present invention, the polyurethane resin (A) is used for both the anchor coating agent and the thermal adhesive. By using the polyurethane resin (A) for the anchor coating agent layer 3 and the thermal adhesive layer 4 that are in close contact with each other, there is an effect of strengthening the adhesion between the layers at the time of thermal bonding. Therefore, the polyurethane resin (A) used for the anchor coating agent layer 3 and the thermal adhesive layer 4 is preferably the same.

Examples of the package to be heat sealed using this heat sealing lid material include cup type, bottle type, pack type, cylindrical type, tube type, tray type synthetic resin container, etc., among others, the synthesis of quadruple pot packs. Resin containers are suitable. For example, it is desirable to use a material such as polystyrene, polypropylene, or PET, and to have a heat seal flange at the opening of these containers. Depending on the material of each resin container, it is preferable to appropriately use the thermal adhesive layer 4 suitable for the resin container. Particularly, for the container made of polystyrene, the polyurethane resin (A) and the acrylic / polyester / polyolefin graft polymer (C) are used. It is preferable to use it as the thermal adhesive layer 4. The heat sealing condition depends on the type and thickness of the resin, but is usually about 140 to 240 ° C. and about 0.3 to 5 seconds. The heat-sealing lid material of the present invention is particularly suitable for a container that is ring-sealed (heat-sealing the lid material to a flange portion of a synthetic resin container in a concave or convex cross section). A width of 0.3 to 3 mm, a depth of the concave portion, or a height of the convex portion of 0.1 to 5 mm is preferable. Note that the bottom surface and the wall surface of the recess may not be completely straight, but may be gently curved or inclined, and the corner may be rounded even if it is not a perfect corner. By providing such a ring seal, the sealing performance is further improved.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these Examples. In the present invention, “parts” and “%” represent “parts by weight” and “% by weight” unless otherwise noted.

<Method of measuring amine value>
Weigh 0.5-2 g of sample accurately. (Sample amount: Sg) 30 mL of neutral ethanol (BDG neutral) is added to a precisely weighed sample and dissolved. The obtained solution is titrated with a 0.2 mol / l ethanolic hydrochloric acid solution (titer: f). The point at which the color of the solution changed from green to yellow was taken as the end point, and the amine value was determined by the following (Formula 1) using the titration amount (AmL) at this time.
(Formula 1) Amine number = (A × f × 0.2 × 56.108) / S

<Number average molecular weight (Mn), weight average molecular weight (Mw)>
The number average molecular weight (Mn) and the weight average molecular weight (Mw) were measured using Showa Denko GPC (gel permeation chromatography) “Shodex GPC System-21”. GPC is liquid chromatography that separates and quantifies substances dissolved in a solvent based on the difference in molecular size. Tetrohydrofuran is used as a solvent, and weight average molecular weight (Mn) is determined in terms of polystyrene.

<Hydroxyl value (OHV)>
About 1 g of a sample is accurately weighed in a stoppered Erlenmeyer flask and dissolved by adding 100 ml of a toluene / ethanol (volume ratio: toluene / ethanol = 2/1) mixed solution. Further, exactly 5 ml of an acetylating agent (a solution in which 25 g of acetic anhydride was dissolved in pyridine to make a volume of 100 ml) was added and stirred for about 1 hour. To this, phenolphthalein reagent is added as an indicator and lasts for 30 seconds. Thereafter, the solution is titrated with a 0.1N alcoholic potassium hydroxide solution until the solution becomes light red.
The hydroxyl value was determined by the following (Formula 2). The hydroxyl value was a numerical value in the dry state of the resin (unit: mgKOH / g).
(Formula 2) Hydroxyl value (mgKOH / g) = [{(ba) × F × 28.25} / S] / (Nonvolatile content concentration / 100) + D
Where S: Amount of sample collected (g)
a: Consumption of 0.1N alcoholic potassium hydroxide solution (ml)
b: Consumption of 0.1N alcoholic potassium hydroxide solution in the empty experiment (ml)
F: Potency of 0.1N alcoholic potassium hydroxide solution
D: Acid value (mgKOH / g)

<Acid value (AV)>
About 1 g of sample compound (B) was accurately weighed in a stoppered Erlenmeyer flask, and dissolved by adding 100 ml of a toluene / ethanol (volume ratio: toluene / ethanol = 2/1) mixed solution. To this was added a phenolphthalein test solution as an indicator, which was held for 30 seconds, and then titrated with a 0.1N alcoholic potassium hydroxide solution until the solution turned light red. As the value of the resin in the dry state, the acid value (mgKOH / g) was determined by the following (Formula 3).
(Formula 3) Acid value (mgKOH / g) = {(5.611 × a × F) / S} / (Nonvolatile content concentration / 100)
Where S: Amount of sample collected (g)
a: Consumption of 0.1N alcoholic potassium hydroxide solution (ml)
F: Potency of 0.1N alcoholic potassium hydroxide solution

(Synthesis example of polyester diol)
In a round bottom flask equipped with a stirrer, a thermometer, a water separator and a nitrogen gas introduction tube, 56.846 parts of 2-butyl-2-ethyl-1,3-propanediol (hereinafter abbreviated as BEPG) and 43. adipic acid. 152 parts and 0.002 part of tetrabutyl titanate were charged, and esterification was carried out for 8 hours while removing water produced by condensation at 230 ° C. under a nitrogen stream. After confirming that the acid value of the polyester was 15 or less, the degree of vacuum was gradually raised with a vacuum pump to complete the reaction. As a result, a polyester diol having a hydroxyl value of 56.1 mgKOH / g (number average molecular weight 2000 calculated from the hydroxyl value) and an acid value of 0.3 mgKOH / g was obtained.

(Synthesis example of polyurethane resin varnish (A1))
A four-necked flask equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen gas inlet tube is charged with 22.226 parts of the polyester diol, 5.434 parts of isophorone diisocyanate, and 7.500 parts of ethyl acetate. The mixture was reacted at 120 ° C. for 6 hours under a stream of air, and 7.500 parts of ethyl acetate was added and cooled to obtain 42.663 parts of a solution of a terminal isocyanate prepolymer. Next, 42.663 parts of the solvent solution of the obtained terminal isocyanate prepolymer was added to a mixture of 2.203 parts of isophoronediamine, 0.138 parts of di-n-butylamine, 20.000 parts of ethyl acetate and 20.000 parts of ethanol. Gradually added at room temperature, then allowed to react at 50 ° C. for 1 hour, added with 15.000 parts of ethanol, polyurethane resin varnish having a solid content of 30.0%, a weight average molecular weight of 24,000, an amine value of 4.0 mg KOH / resin of 1 g. (A1) was obtained.

(Synthesis example of polyurethane resin varnish (A2))
In the same manner as in the synthesis example of urethane-based resin 1, 22.226 parts of the above-mentioned polyester diol, 5.434 parts of isophorone diisocyanate, and 7.500 parts of ethyl acetate were charged and reacted at 120 ° C. for 6 hours under a nitrogen stream. 7.500 parts of ethyl acetate was added and cooled to obtain 42.663 parts of a solution of a terminal isocyanate prepolymer. Next, 42.663 parts of a solvent solution of the resulting terminal isocyanate prepolymer was added to a mixture of 4.406 parts of isophoronediamine, 0.138 parts of di-n-butylamine, 20.000 parts of ethyl acetate and 20.000 parts of ethanol. Gradually added at room temperature, then reacted at 50 ° C. for 1 hour, added with 15.000 parts of ethanol, polyurethane resin varnish having a solid content of 30.0%, a weight average molecular weight of 24,000, an amine value of 8.0 mg KOH / resin of 1 g. (A2) was obtained.

(Synthesis example of polyurethane resin varnish (A3))
In the same manner as in the synthesis example of urethane-based resin 1, 22.226 parts of the above-mentioned polyester diol, 5.434 parts of isophorone diisocyanate, and 7.500 parts of ethyl acetate were charged and reacted at 120 ° C. for 6 hours under a nitrogen stream. 7.500 parts of ethyl acetate was added and cooled to obtain 42.663 parts of a solution of a terminal isocyanate prepolymer. Next, 42.663 parts of the solvent solution of the obtained terminal isocyanate prepolymer was added to a mixture of 8.812 parts of isophoronediamine, 0.138 parts of di-n-butylamine, 20.000 parts of ethyl acetate and 20.000 parts of ethanol. Slowly add at room temperature, then react at 50 ° C. for 1 hour, add 15.000 parts of ethanol, polyurethane resin varnish with solid content 30.0%, weight average molecular weight 24000, amine value 13.0 mg KOH / resin 1 g (A3) was obtained.

(Preparation of vinyl chloride / vinyl acetate copolymer resin varnish (B1))
30 parts of vinyl chloride / vinyl acetate copolymer resin (Solvain TAO: manufactured by Nissin Chemical Industry Co., Ltd.) is mixed and dissolved in 70 parts of ethyl acetate to prepare a vinyl chloride / vinyl acetate copolymer resin varnish (B1). Obtained. Solvain TAO has a softening point of 78 ° C., a number average molecular weight of 15,000, and a monomer ratio of vinyl chloride: vinyl acetate: vinyl alcohol of 91: 2: 7.

(Preparation of vinyl chloride / vinyl acetate copolymer resin varnish (B2))
30 parts of vinyl chloride / vinyl acetate copolymer resin (VINNOL E15 / 45: manufactured by Nissin Chemical Industry Co., Ltd.) is mixed and dissolved in 70 parts of ethyl acetate, and vinyl chloride / vinyl acetate copolymer resin varnish (B2 ) VINNOL E15 / 45 has a softening point of 75 ° C., a number average molecular weight of 13,000, and a monomer ratio of vinyl chloride: vinyl acetate: vinyl alcohol of 85: 15: 0.

<Example of production of anchor coating agent>
(Production Example 1)
After stirring and mixing 23.3 parts of polyurethane resin varnish (A2), 54.3 parts of vinyl chloride / vinyl acetate copolymer resin varnish (B1), 12.5 parts of ethyl acetate and 10 parts of ethanol, anchor coating agent a1 was added. Obtained. 100 parts of the anchor coating agent a1, 50 parts of an ethyl acetate / ethanol mixed solvent (weight ratio 50/50) as a diluent solvent, 5 parts of Duranate D101 (manufactured by Asahi Kasei Corporation) are added and mixed as a polyisocyanate curing agent, Diluted anchor coating agent a1 was obtained.

(Production Examples 2 to 10)
Anchor coating agents a2 to a10 were obtained in the same manner as in Production Example 1 using the resins and blends shown in Table 1. Further, diluted anchor coating agents a2 to a10 were also obtained in the same manner as in Production Example 1.

(Synthesis example of graft polymer dispersion (C))
The polyester polymer used for the graft polymer dispersion (C) was synthesized by the following method.
Itaconic acid (286 g, 2.2 mol), isophthalic acid (282 g, 1.7 mol), terephthalic acid (132 g, 0.8 mol), monoethylene glycol (120 g, 1.9 mol), neopentyl glycol (129 g, 1.2 mol) and hexanediol-1,6 (211 g, 1.8 mol) were melted in a stream of nitrogen in a flask with a 2 L column and distillation fitting. When a temperature of 170 ° C. was reached, water began to be distilled off. Within 2 hours, this temperature gradually increased to 240 ° C. Further reaction was carried out at this temperature for about 4 hours. 150 mg of titanium tetrabutoxide was added and further processed under reduced pressure. Finally, a polyester polymer having 2 mol% of itaconic acid, a weight average molecular weight of 13400, a hydroxyl value of 35 mgKOH / resin, and an acid value of 1.2 mgKOH / resin was obtained.

Next, 42.9 g of EPDM (polyolefin polymer with ethylene-propylene-diene-rubber, Buna EP6170) and 20 g of the polyester polymer were placed in a mixture of 50 g of propyl acetate, 20 g of ethyl acetate and 10 g of isooctane in a stirring tank. Disperse at 90 ° C. To this mixture is first added 2 g of tert-butyl perbenzoate, followed by a mixture of 18.5 g of n-butyl methacrylate and 18.5 g of methyl methacrylate over a period of 90 minutes. The polymerization is subsequently carried out at 90 ° C. over a period of 120 minutes. Subsequently, 0.5 g of tert-butyl perbenzoate is added for the subsequent start and further stirred at 90 ° C. for 90 minutes. The proportion of polymer is about 45% by weight and the proportion of solvent is about 55% by weight.

After a total reaction time of 150 minutes, the polymer solution was cooled and diluted with 13.5 g of propyl acetate to reduce the concentration of the solution to obtain a graft polymer (C).

The graft polymer (C) has an acrylic / polyester / polyolefin graft polymer as a main component, and includes other binary copolymers and homopolymerized acrylic polymers.

(Acrylic resin (D))
DEGALAN P24 (manufactured by Evonik Industries AG) was used for the acrylic resin (D).

<Examples of thermal adhesive production>
(Production Example 11)
After 50.0 parts of the polyurethane resin varnish (A2), 33.3 parts of the graft polymer (C) and 16.7 parts of ethyl acetate were mixed with stirring, a thermal adhesive b1 was obtained.

(Production Examples 12 to 22)
Thermal adhesives b2 to b12 were obtained in the same manner as in Production Example 11 using the resins and blends shown in Table 2.

Example 1
Under the following printing conditions, the diluted anchor coating agent a1 and the thermal adhesive b1 are sequentially printed on the opposite side of the gas barrier layer of the polyester film, which is a base material layer having a gas barrier layer, and the anchor coating agent layer, The cover material 1 which laminated | stacked the adhesive bond layer one by one was obtained.

[Printing conditions]
Printing machine: Gravure printing machine manufactured by Fuji Machine Industry Co., Ltd. Printing film: High Barrier <Tech Barrier> (Mitsubishi Chemical Kojin Packs Co., Ltd.)
Impression cylinder: NBR (nitrile butadiene rubber) doctor with rubber hardness of 80Hs: Ceramic plated doctor blade with a cutting edge thickness of 60 μm (base material thickness 40 μm, one side ceramic layer thickness 10 μm)
Plate: Toyo Prepress Co., Ltd., chrome hardness 1050Hv electronic engraving plate (stylus angle 130 degrees, for anchor coating agent: 175 lines / inch, for thermal adhesive: 100 lines / inch)
Printing pressure: 2kg / cm ²
Doctor pressure: 2kg / cm ²
Printing speed: 60 m / min Drying temperature: F100 ° C

(Examples 2 to 16)
Diluted anchor coating agents a1 to a8 and thermal adhesives b1 to b9 were printed and laminated in the same manner as in Example 1 as described in Table 3 to obtain lid materials 2 to 16.

(Comparative Examples 1-5)
Diluted anchor coating agents a3 and a9 to a10 and thermal adhesives b4 and b10 to b12 were printed and laminated in the same manner as in Example 1 as described in Table 4 to obtain lid materials 17 to 21.

In addition, the base material used in Examples 1-16 and Comparative Examples 1-5 is the same.

The evaluation was conducted at four points: a strength test at room temperature, an adhesive strength test after standing at 100 ° C. for 10 minutes, an adhesive strength after ultraviolet irradiation, and a friction resistance test. The results are shown in Tables 3 and 4.

<Adhesive strength test at room temperature>
A 15mm x 60mm strip is punched from each lid, and a thermal adhesive layer of the lid is combined with a 15mm x 30mm strip of polystyrene sheet, and heat-bonded under the following conditions using a single-acting heat sealer. The strength of the part was measured by an autograph (manufactured by Shimadzu Corporation) at a peeling angle of 180 degrees and a peeling speed of 300 mm / min.
Thermal bonding conditions Thermal bonding temperature: 200 ° C
Thermal bonding condition: 1.0 second Thermal bonding pressure: 2 kg / cm ²

A: 10 N / 15 mm or more B: 7 N / 15 mm or more and less than 10 N / 15 mm Δ: 5 N / 15 mm or more and less than 7 N / 15 mm (above practical level)
X: Less than 5N / 15mm

<Adhesive strength test after standing at 100 ° C. for 10 minutes>
A 15 mm × 60 mm strip is punched from each lid, and a thermal adhesive layer of the lid is combined with a 15 mm × 30 mm strip of polystyrene sheet and thermally bonded by a single-acting heat sealer under the following conditions, 100 ° C. After being left in the oven for 10 minutes, the strength of the heat-bonded portion was measured by an autograph (manufactured by Shimadzu Corporation) at a peeling angle of 180 degrees and a peeling speed of 300 mm / min.

A: 5 N / 15 mm or more (practical level or more)
X: Less than 5N / 15mm

<Adhesive strength after UV irradiation>
Each cover is punched into a 15 mm x 60 mm strip, irradiated with an ultraviolet ray equivalent to 1,000,000 μw · sec / mm 2 by a UV sterilizer with conveyor, and then applied to a 15 mm x 30 mm strip polystyrene sheet. The thermal adhesive layers of the lid are combined and thermally bonded with a single-acting heat sealer under the following conditions, and the strength of the thermally bonded portion is peeled off by an autograph (manufactured by Shimadzu Corporation) at a peeling angle of 180 degrees and a peeling speed of 300 mm / Measured in minutes.
Thermal bonding conditions Thermal bonding temperature: 200 ° C
Thermal bonding condition: 1.0 second Thermal bonding pressure: 2 kg / cm ²

A: 10 N / 15 mm or more B: 7 N / 15 mm or more and less than 10 N / 15 mm Δ: 5 N / 15 mm or more and less than 7 N / 15 mm (above practical level)
X: Less than 5N / 15mm

<Friction resistance test>
Using a Gakushin type anti-friction tester, the removal of the thermal adhesive when rubbing 100 times with a load of 200 g for each high-quality paper opposite to the lid material was evaluated based on the following evaluation criteria.

A: The thermal adhesive layer was not removed.
○: The thermal adhesive layer was hardly removed. (Less than 10%)
(Triangle | delta): Although the removal of the heat adhesive bond layer generate | occur | produced, it was a practical use level. (10% or more and less than 30%)
X: The thermal adhesive layer was removed and did not reach a practical level. (30% or more)

In Examples 1 to 16, the anchor coating agent contains a polyurethane resin (A) and a vinyl chloride / vinyl acetate copolymer resin (B), and the thermal adhesive is a polyurethane resin (A) and an acrylic / polyester / polyolefin graft. By containing the polymer (C), the adhesive strength at room temperature could be obtained without deteriorating the friction resistance. Furthermore, the hot bond strength and the strength after UV irradiation were also excellent. Further, by using an acrylic resin (D) as the thermal adhesive, the adhesive strength at room temperature and the strength after ultraviolet irradiation were improved.
On the other hand, in Comparative Examples 1 to 3, the adhesive strength at normal temperature or hot adhesive strength and the adhesive strength after ultraviolet irradiation were insufficient compared to the Examples. In Comparative Example 4 using the thermal adhesive used in the conventional method, the friction resistance was greatly reduced, and in Comparative Example 5, the hot adhesive strength and the adhesive strength after ultraviolet irradiation were reduced.

Claims (5)

A heat sealing lid material in which a base material layer having a gas barrier layer, an anchor coating agent layer formed by applying an anchor coating agent, and a thermal adhesive layer formed by applying a thermal adhesive are sequentially laminated, A heat-sealing lid material characterized by being 1) and (2).
(1) The anchor coat agent contains a polyurethane resin (A) and a vinyl chloride / vinyl acetate copolymer resin (B).
(2) The thermal adhesive contains a polyurethane resin (A) and an acrylic, polyester, and polyolefin graft copolymer resin (C). The heat sealing lid material according to claim 1, wherein the thermal adhesive further contains an acrylic resin (D) other than an acrylic, polyester, and polyolefin graft copolymer resin (C) . A heat sealing lid material in which a base material layer having a gas barrier layer, an anchor coating agent layer formed by applying an anchor coating agent, and a thermal adhesive layer formed by applying a thermal adhesive are sequentially laminated, A heat-sealing lid material characterized by 1) and (2).
(1) 40 to 70 parts by weight of the polyurethane resin (A) and 30 to 60 parts by weight of the vinyl chloride / vinyl acetate copolymer resin (B) in 100 parts by weight of the solid content of the anchor coating agent.
(2) 15 to 35 parts by weight of polyurethane resin (A), 15 to 35 parts by weight of acrylic, polyester, and polyolefin graft copolymer resin (C) in 100 parts by weight of solid content of thermal adhesive, acrylic resin (D ) Is 40-60 parts by weight. The heat sealing lid material according to any one of claims 1 to 3, wherein the gas barrier layer is a metal vapor deposition layer. Package is a heat sealed lid according to any one of claims 1 to 4, composed of a synthetic resin container, the opening of the synthetic resin container, characterized by comprising a heat sealed by heat sealing a lid member packaging body.

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