TW201831633A - Adhesive for sealant and film for lid material - Google Patents

Abstract

The present invention provides an adhesive for sealant and a film for a lid material, having excellent moldability, satisfying sealing strength and adhesion strength for an A-PET container and used for a lid material of an A-PET container. The present invention provides the adhesive for sealant and the film for a lid material, wherein the adhesive comprises: 10-50 parts by weight of ethylene-acetic acid vinyl copolymer (A) having 3-15 wt% of content of acetic acid vinyl; 10-50 parts by weight of ethylene-acetic acid vinyl copolymer (B) having 8-25 wt% of acetic acid vinyl content; and 5-40 parts by weight of tackifier resin, wherein the sum of (A), (B), and (C) is 100 parts by weight. Difference between the content of the acetic acid vinyl of the ethylene-acetic acid vinyl copolymer (A) and the content of the acetic acid vinyl of the ethylene-acetic acid vinyl copolymer (B) is 3-20 wt%.

Description

   Adhesive for container lid material sealant and film for container lid material   

The present invention relates to a film for a lid material of a container. More specifically, the present invention relates to an amorphous polyparaphenylene that is excellent in molding processability, can obtain high sealing strength and adhesion strength, and has excellent heat resistance. An adhesive for a sealant of a lid material of a container made of polyethylene terephthalate (hereinafter referred to as A-PET), and a film for a lid material.

Conventionally, packaging of food, pharmaceuticals, industrial parts, and the like has used plastic containers such as polyethylene, polypropylene, and polystyrene, or paper-based paper containers, and the cover material has been used to protect the contents. An easily peelable film having stable adhesive strength and easy peelability that can be opened at an appropriate strength at the time of peeling. Many materials have been known for containers such as polypropylene and polystyrene. However, in recent years, A-PET containers that are inexpensive, excellent in transparency and cold resistance have not been found to be excellent in practical use. Easy peeling film. In the case of a conventional easy-release film, which is used for a lid material of an A-PET container, there is a problem that the lid is accidentally opened due to vibration or dropping during transportation or storage due to weak bonding strength, or because it is desired to obtain high Next, the strength has to be set to a high heat-sealing temperature, which causes a problem that the container is deformed and the sealability is reduced. In addition, there is a disadvantage that the sealing strength is lowered when stored in a low-temperature environment after that, and there are problems in practical use. In general, as an adhesive for a lid material and a sealant, a mixture of polyethylene, an ethylene-vinyl acetate copolymer, and a tackifier is known. However, such a material cannot sufficiently adhere to an A-PET container. strength. Furthermore, a resin composition (for example, refer to Patent Document 1) composed of an ethylene · α-olefin copolymer and an olefin-based elastomer and / or a styrene-based elastomer and a tackifier may be used, or an ethylene · α-olefin A sealant material composed of a copolymer, an ethylene-polar monomer copolymer, an ABA-type block copolymer, and a tackifier (for example, refer to Patent Document 2). However, it cannot satisfy all aspects of molding processability and sealing strength. And then intensity.

[Prior technical literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 1999-269319

[Patent Document 2] Japanese Patent No. 4438108

However, none of the above methods can sufficiently satisfy molding processability, sealing strength to A-PET containers, and adhesion strength.

An object of the present invention is to provide an adhesive for a sealant and a film for a lid material, which can be used as a lid material for an A-PET container, and has excellent molding processability, and satisfies the sealing strength and adhesion strength for an A-PET container.

The present inventors conducted intensive studies on the above-mentioned problems, and as a result, found that the sealant adhesive for sealants containing specific two types of ethylene-vinyl acetate copolymers and tackifiers is excellent in moldability and sealability for A-PET containers The strength and the bonding strength were excellent, and the present invention was completed.

That is, the present invention relates to an adhesive for a sealant for a lid material of a container, and a film for a lid material, comprising 10 to 50 parts by weight of an ethylene-vinyl acetate copolymer having a vinyl acetate content of 3 to 15% by weight. (A), 10 to 50 parts by weight of an ethylene-vinyl acetate copolymer (B) with a vinyl acetate content of 8 to 25% by weight, and 5 to 40 parts by weight of a tackifier resin (C) ((A) , (B) and (C) total 100 parts by weight), where the difference between the vinyl acetate content of the ethylene-vinyl acetate copolymer (A) and the vinyl acetate content of the ethylene-vinyl acetate copolymer (B) is From 3 to 20% by weight, the vinyl acetate content of the ethylene-vinyl acetate copolymer (A) is smaller than the vinyl acetate content of the ethylene-vinyl acetate copolymer (B).

The present invention is explained in detail below.

The adhesive for the sealant of the lid material of the container of the present invention comprises 10 to 50 parts by weight of an ethylene-vinyl acetate copolymer (A) having a vinyl acetate content of 3 to 15% by weight, and 10 to 50 parts by weight of vinyl acetate. The ester content is 8 to 25% by weight of the ethylene-vinyl acetate copolymer (B) and 5 to 40% by weight of the tackifier resin (C) ((A), (B), and (C) total 100 weight Parts), where the difference between the vinyl acetate content of the ethylene-vinyl acetate copolymer (A) and the vinyl acetate content of the ethylene-vinyl acetate copolymer (B) is 3 to 20% by weight, and the ethylene-vinyl acetate copolymerization The vinyl acetate content of the substance (A) is smaller than the vinyl acetate content of the ethylene-vinyl acetate copolymer (B).

The ethylene-vinyl acetate copolymer (A) is preferably composed of a vinyl acetate content of 3 to 15% by weight, and preferably 5 to 10% by weight. In the case where the content of vinyl acetate is less than 3% by weight, the low-temperature heat sealability of the obtained adhesive for a sealant is poor, so it should not be less than 3% by weight. On the other hand, when the content of vinyl acetate exceeds 15% by weight, the molding processability of the obtained adhesive for a sealant is poor, and therefore it should not exceed 15% by weight. In addition, the vinyl acetate content in the ethylene-vinyl acetate copolymer can be measured using a method measured according to JIS K 6924-1.

In addition, the melt flow rate of the ethylene-vinyl acetate copolymer (A) measured according to JIS K 6924-1 at a temperature of 190 ° C and a load of 21.18N is between 1 and 30 grams / A range of 10 minutes is preferable, and a range of 3 to 15 g / 10 minutes is particularly preferable. When the melt flow rate is 1 g / 10 minutes or more, the obtained adhesive for a sealant is excellent in molding processability and bonding strength, and is therefore preferable. On the other hand, when the melt flow rate is 30 g / 10 minutes or less, the obtained adhesive for a sealant is excellent in molding process stability and is therefore preferred.

The ethylene-vinyl acetate copolymer (A) can be obtained by a conventional production method, or a commercially available product can be used. Specific examples include (trade names) ultrathene 515, ultrathene 537, ultrathene 540, ultrathene 541 (manufactured by Tosoh Corporation), and the like.

The ethylene-vinyl acetate copolymer (B) is preferably composed of a vinyl acetate content of 8 to 25% by weight, and preferably 10 to 20% by weight. In the case where the content of vinyl acetate is less than 8% by weight, the obtained adhesive for a sealant is inferior in low-temperature heat-sealing properties and adhesion strength, so it should not be less than 8% by weight. On the other hand, when the content of vinyl acetate exceeds 25% by weight, the molding processability and blocking properties of the obtained adhesive for a sealant are inferior, so it should not exceed 25% by weight. In addition, the vinyl acetate content in the ethylene-vinyl acetate copolymer can be measured using a method measured according to JIS K 6924-1.

In addition, the aforementioned ethylene-vinyl acetate copolymer (B) has a melt flow rate measured in accordance with JIS K 6924-1 at a temperature of 190 ° C and a load of 21.18 N in a range of 1 to 30 g / 10 minutes. For the sake of preference, a range of 3 to 20 g / 10 minutes is particularly preferred. When the melt flow rate is 1 g / 10 minutes or more, the obtained adhesive for a sealant is excellent in molding processability and bonding strength, and is therefore preferable. On the other hand, when the melt flow rate is 30 g / 10 minutes or less, the obtained adhesive for a sealant is excellent in molding process stability and is therefore preferred.

The ethylene-vinyl acetate copolymer (B) can be obtained by a conventional production method, or a commercially available product can be used. Specific examples include (trade names) ultrathene 541, ultrathene 626, ultrathene 625, ultrathene 633 (manufactured by Tosoh Corporation), and the like.

The difference between the vinyl acetate content of the ethylene-vinyl acetate copolymer (A) and the vinyl acetate content of the ethylene-vinyl acetate copolymer (B) of the present invention is 3 to 20% by weight, and 3 to 15% by weight Is better. When the difference in the content of vinyl acetate is less than 3% by weight, the adhesive strength of the obtained adhesive for a sealant is poor, so it should not be less than 3% by weight. On the other hand, when it exceeds 20% by weight, the molding process stability of the obtained adhesive for a sealant is poor, so it should not exceed 20% by weight.

Any tackifier (C) constituting the present invention may be used as long as it belongs to the category of tackifiers, and examples thereof include petroleum resins and coumarone resins which are synthetic petroleum resin-based tackifiers. Rosin resin, methyl ester resin, glycerol ester resin, pentaerythritol ester resin, terpene resin and the above-mentioned modification Things. Among these tackifiers, synthetic petroleum resin-based tackifiers include aliphatic petroleum resins, aliphatic hydrogenated petroleum resins, aromatic petroleum resins, aromatic hydrogenated petroleum resins, alicyclic petroleum resins, and fats. Ring family hydrogenated petroleum resin, co-cluster hydrogenated petroleum resin, etc. Among these tackifiers, it is preferable to use an aromatic hydrogenated petroleum resin or an alicyclic hydrogenated petroleum resin. In particular, for excellent sealing strength and adhesive strength, at least one selected from the group consisting of aliphatic petroleum resin, aromatic petroleum resin, alicyclic hydrogenated petroleum resin, and co-cluster petroleum resin. 50 ~ 90% is better after partial hydrogenation. These materials can be used alone or in combination of two or more.

The softening point of the tackifier (C) measured by the ring and ball method is preferably in a range of 90 to 140 ° C, and particularly preferably 100 to 135 ° C. When the softening point is lower than 90 ° C, the adhesion resistance is poor, and when the softening point is higher than 140 ° C, the adhesion strength in a low temperature environment is poor.

As the thickener (C), a commercially available thickener can be used. Specific examples include (brand names) ARKON M90, ARKON M115, ARKON M135, ARKON P100, ARKON P125, Aimabu S110, Aimabu P125, T-REZ RC115, T-REZ HA125, PineCrystal KE-311, YS Resin PX 1150, YS Resin PX 1150 N, etc.

The blending amounts of the ethylene-vinyl acetate copolymer (A), the ethylene-vinyl acetate copolymer (B), and the tackifier (C) are as follows. (A), (B), and (C) are 100 parts by weight in total.

The blending ratio of the ethylene-vinyl acetate copolymer (A) is 10 to 50 parts by weight, especially because it can constitute a sealant adhesive having an excellent balance between adhesion strength and molding processability, and 20 to 40 parts by weight is Better. In the case of less than 10 parts by weight, the stability of the molding process of the obtained adhesive for a sealant is poor, so it should not be less than 10 parts by weight. On the other hand, when it exceeds 50 weight part, since the adhesive strength of the adhesive agent for sealants obtained becomes insufficient, it should not exceed 50 weight part.

The blending ratio of the ethylene-vinyl acetate copolymer (B) is 10 to 50 parts by weight, especially because it can constitute a sealant adhesive having an excellent balance between adhesion strength and molding processability. 20 to 40 parts by weight Better. In the case of less than 10 parts by weight, the adhesive strength of the obtained adhesive for a sealant is poor, so it should not be less than 10 parts by weight. On the other hand, when it exceeds 50 parts by weight, the obtained molding adhesive has poor molding process stability and poor adhesiveness. Therefore, it should not exceed 50 parts by weight.

The blending amount of the thickener (C) is 5 to 40 parts by weight, and 15 to 30 parts by weight is particularly preferred. In the case of less than 5 parts by weight, the sealing strength and adhesive strength of the obtained adhesive for a sealant are inferior, so it should not be less than 5 parts by weight. On the other hand, when it exceeds 40 parts by weight, roll release properties during molding processing are inferior, and a problem of blocking by rolling may occur. Therefore, it is not preferable to exceed 40 parts by weight.

The adhesive for the sealant of the present invention, in particular, can form a sealant for the sealant which is excellent in low-temperature sealability and sealing strength. The ethylene · α-olefin copolymer (D) is preferably mixed, and the ethylene · α-olefin The density of the copolymer (D) measured by JIS K 6922-1 (1998) is in the range of 860 to 910 kg / m 3. Then, the blending amount in this case was 100 weight based on the total amount of the ethylene-vinyl acetate copolymer (A), the ethylene-vinyl acetate copolymer (B), and the tackifier resin (C). The aforementioned ethylene · α-olefin copolymer (D) is preferably 10 to 50 parts by weight, and particularly preferably 20 to 40 parts by weight.

As the aforementioned ethylene · α-olefin copolymer (D), any one may be used as long as it belongs to the category generally referred to as an ethylene · α-olefin copolymer. The α-olefin is not particularly limited, but examples thereof include propylene having 3 to 12 carbon atoms, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1 -Octene, 1-decene, 1-dodecane and the like. These ethylene · α-olefin copolymers (D) can be appropriately produced by using a Ziegler catalyst, a chromium-based catalyst, or a metallocene catalyst and copolymerizing ethylene with an α-olefin. Examples of the polymerization method include a solution polymerization method, a high-pressure polymerization method, and a gas phase polymerization method. Furthermore, this ethylene · α-olefin copolymer (D) uses gel permeation chromatography (Gel Permeation Chromatography) under the conditions shown below, and uses a monodisperse polystyrene to measure a universal calibration curve as a straight line. The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) calculated from the molecular weight of the chain polyethylene is 3 or less, and it is preferable because it has excellent low-temperature heat sealability and sealing strength.

Model: 150 C ALC / GPC made by Waters

Solvent: 1,2,4-trichlorobenzene

Flow rate: 1 ml / min

Temperature: 140 ° C

Measurement concentration: 30 mg / 30 ml

Injection volume: 100 μl

Column (column): Tosoh (stock) system, TSKgel GMH HR-H 3 column

In addition, the ethylene · α-olefin copolymer (D) was obtained by measuring the temperature (Tm (° C)) of the maximum peak position of the endothermic curve obtained by the differential scanning calorimeter in the temperature rise measurement and measuring from the infrared absorption spectrum. When the number of short-chain branches (SCB) per 1,000 carbon atoms satisfies the relationship of the formula (1), the composition distribution of the ethylene · α-olefin copolymer is narrow, and the low-density (short (High number of chain branches) is preferred because it has few components. This is because the greater the number of short chain branches (SCB) per 1,000 carbon atoms of the ethylene · α-olefin copolymer (D), the lower the density and the lower the melting point. Even if the number of short-chain branches is increased in order to lower the melting point, and a large number of short-chain branches are introduced into the low-molecular-weight portion, the melting point of the ethylene · α-olefin copolymer containing a large amount of low density (high number of short-chain branches) may change. high. On the other hand, even if the ethylene · α-olefin copolymer has the same number of short chain branches, the short chain branches are uniformly introduced from the low molecular weight to the high molecular weight, and the ethylene‧α contains a large amount of low density (high number of short chain branches). -Compared with olefin copolymers, the melting point also becomes lower.

Tm <-1.8 * SCB + 140 (1)

The ethylene · α-olefin copolymer (D) as described above can be produced, for example, by a method disclosed in Japanese Patent Publication below.

Examples include Japanese Patent Laid-Open No. 60-35006, Japanese Patent Laid-Open No. 60-35007, Japanese Patent Laid-Open No. 60-35008, Japanese Patent Laid-Open No. 3-163088, and Japanese Patent Laid-Open No. 61-296008. Gazette, Japanese Patent Laid-Open No. 63-22804, Japanese Patent Laid-Open No. 58-19309, Japanese Patent Laid-Open No. 63-61010, Japanese Patent Laid-Open No. 63-152608, Japanese Patent Laid-Open No. 63-264606 Gazette, Japanese Patent Laid-Open No. 63-280703, Japanese Patent Laid-Open No. 64-6003, Japanese Patent Laid-Open No. 1-95110, Japanese Patent Laid-Open No. 3-62806, Japanese Patent Laid-Open No. 1-259004, Japan JP-A-Sho 64-45406, JP-A-Sho 60-106808, JP-A-Sho 60-137911, JP-A-Sho 61-296008, JP-A-63-501369, JP-A Japanese Patent Application Publication No. 61-221207, Japanese Patent Application Publication No. 2-22307, Japanese Patent Application Publication No. 2-173110, Japanese Patent Application Publication No. 2-024410, Japanese Patent Application Publication No. 1-129003, Japanese Patent Application Publication No. 1-210404 Japanese Patent Publication, Japanese Patent Application Laid-Open No. 3-66710, Japanese Patent Application Laid-Open No. 3-70710, Japanese Patent Laid-Open No. 1-207248, Japanese Patent Laid-Open No. 63-222177, Japanese Patent Laid-Open No. 63-222178, Japanese Patent Laid-Open No. 63-222179, Japanese Patent Laid-Open No. 1-12407, Japanese Patent No. Kaihei No. 1-301704, Japanese Laid-Open No. 1-319489, Japanese Laid-Open No. 3-74412, Japanese Laid-Open No. 61-264010, Japanese Laid-Open No. 1-275609, Japanese Laid-Open No. 63- Japanese Gazette No. 251405, Japanese Gazette No. 64-74202, Japanese Gazette No. 2-41303, Japanese Gazette No. 1-31488, Japanese Gazette No. 3-56508, Japanese Gazette No. 3-70708, Japanese Patent Laid-Open No. 3-70709 and the like.

The ethylene · α-olefin copolymer (D) may be a commercially available product.

The adhesive for a sealant of the present invention is particularly preferably a thermoplastic block copolymer (E) in which a vinyl aromatic hydrocarbon and an olefin or a diene are mixed because the adhesive strength and the sealing strength become excellent. Then, the blending amount in this case was 100 weight based on the total amount of the ethylene-vinyl acetate copolymer (A), the ethylene-vinyl acetate copolymer (B), and the tackifier resin (C). Parts, or 100 parts by weight based on the total amount of the ethylene-vinyl acetate copolymer (A), the ethylene-vinyl acetate copolymer (B), and the tackifier resin (C), mixed with the ethylene ‧ The α-olefin copolymer (D) is preferably 0.5 to 5 parts by weight, and particularly preferably 1 to 4 parts by weight, as the thermoplastic block copolymer (E) of the vinyl aromatic hydrocarbon and olefin or diene.

The thermoplastic block copolymer (E) constituting the vinyl aromatic hydrocarbon and the olefin or diene of the present invention is composed of the general formula (AB) n, (AB) n-A 'or (AB) mX (wherein the general formula A and A 'are vinyl aromatic hydrocarbon polymer blocks, B is an olefin or diene polymer block, n is an integer of 1 to 5, m is an integer of 2 to 7, and X is a polyfunctional compound representing an valence of m. A polymer composed of a linear structure, a radial structure, or a branched structure represented by ()), and having a block structure of at least one end of a vinyl aromatic hydrocarbon polymer block, may also be a hydride thereof. As examples of the vinyl aromatic hydrocarbon used herein, styrene, α-methylstyrene, vinyltoluene, p-tert-butylstyrene, vinylxylene, ethylvinylxylene, ethylene Naphthalene and mixtures thereof. Among them, styrene is particularly preferred. On the other hand, examples of olefins include α-olefins such as ethylene, propylene, and 1-butene, and examples of diolefins include conjugated diene such as butadiene and isoprene. Olefin. As the thermoplastic block copolymer (E) of the vinyl aromatic hydrocarbon and diene, a hydrogenated product of a polymer block of a conjugated diene can be used. Furthermore, as for the block B, as long as the olefin is a main unit, a copolymer of a conjugated diene and a vinyl aromatic hydrocarbon may be used. Among these, in the present invention, a thermoplastic block copolymer of a vinyl aromatic hydrocarbon and an olefin or a diolefin having a vinyl aromatic hydrocarbon polymer block at both ends is preferred. From the viewpoint of improving thermal stability, a polystyrene-polybutadiene-polystyrene block copolymer hydride (styrene-ethylene / butene-styrene triblock copolymer, hereinafter referred to as SEBS) is particularly preferred.

Furthermore, the melt flow rate of the thermoplastic block copolymer (E) of the aforementioned vinyl aromatic hydrocarbon and olefin or diene at 200 ° C and a load of 5.0 kg is within a range of 10 to 70 g / 10 minutes. Preferably, a range of 12 to 65 g / 10 minutes is particularly preferred.

Furthermore, the thermoplastic block copolymer (E) of the vinyl aromatic hydrocarbon and an olefin or a diene can constitute an adhesive for a sealant excellent in molding processability and adhesion strength, and can be hydrogenated styrene-butadiene- A mixture of diblock copolymer and hydrogenated styrene-butadiene-styrene-triblock copolymer. The mixture ratio is preferably 5 / 5-9 / 1, and the styrene content is 20-50 weight. % Is better.

As the thermoplastic block copolymer (E) of the vinyl aromatic hydrocarbon and the olefin or diene, a commercially available product is used. As a specific example, Kraton G1726MS (trade name) (made by Kraton Polymer Co., Ltd.) is mentioned, for example.

The adhesive for the sealant of the present invention may use other thermoplastic resins and rubbers, and light stabilizers, ultraviolet absorbers, nucleating agents, lubricants, antioxidants, Adhesive, flow improver, release agent, flame retardant, colorant, inorganic neutralizer, hydrochloric acid absorbent, filler conductive agent, etc.

As the method for preparing the adhesive for a sealant of the present invention, any method can be used as long as the adhesive for a sealant can be prepared, and examples thereof include a Henschel mixer or a tumbler. The mixer firstly mixes the aforementioned ethylene-vinyl acetate copolymer (A), the aforementioned ethylene-vinyl acetate copolymer (B), and the aforementioned tackifier resin (C) simultaneously, and uniaxially or biaxially extrudes the same Machine for melt-kneading.

The adhesive for a sealant of the present invention can be used as an adhesive for a sealant of a container lid material. This container is suitable for a container containing polyethylene terephthalate as a main component.

The film for a cover material of the present invention has a structure including at least two layers of a support base material layer and the adhesive for a sealant. As the supporting substrate constituting the supporting substrate layer, it is sufficient as long as it has autonomous supportability, and examples thereof include olefin resins such as polyethylene, polypropylene, and ethylene-acid copolymer resins, polyethylene terephthalate, and the like. Polyester resins such as polybutylene terephthalate and polyethylene naphthalate, plastic films made of thermoplastic resins such as polyamide resins, paper such as Japanese paper, composite paper, and aluminum A metal foil made of metal, the above-mentioned single-layer or laminated structure, and the like. The thickness of the supporting substrate layer can be selected according to the application within a range that does not impair the mechanical strength, processability, etc., and is usually about 5 to 100 micrometers (μm), and preferably 10 to 50 micrometers.

The thickness of the adhesive layer for the sealant can be selected according to the application within a range that does not impair the adhesiveness and processability, and is usually about 5 to 50 microns, and preferably 15 to 30 microns.

In the present invention, an intermediate layer may be provided between the support base material layer and the sealant adhesive layer in order to improve the adhesion between the two layers. This intermediate layer can be comprised using components, such as thermoplastic resins, such as polyolefin, and a thermoplastic elastomer, These components can be used individually or in combination of 2 or more types. Examples of polyolefins include polyethylene and ethylene copolymers (ethylene · α-olefin copolymer, propylene-ethylene copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, and ethylene-methyl acrylate copolymer)物 等) and its modification. The intermediate layer may use various additives such as an antioxidant, a lubricant, an antistatic agent, a conductive agent, an anti-blocking agent, and a tackifier, as long as the effect of the present invention is not impaired.

The thickness of the intermediate layer can be selected according to the application within a range that does not impair processability and the like, and is usually about 5 to 30 microns.

In the present invention, an anchor such as polyurethane may be provided between the support base material layer and the sealant adhesive layer or between the support base material layer and the intermediate layer in order to improve the adhesion between the two layers. Anchor coat layer.

The film for a cover material of the present invention is suitable as a cover material for A-PET containers, and has sealing properties and easy peelability.

The method for producing the film for a cover material is not particularly limited, but examples thereof include a method of laminating an adhesive for a sealant and a supporting base material layer, and coextrusion of an adhesive for a sealant and a supporting base material layer. Method, etc. Examples of the method of lamination include (1) an extrusion lamination method in which an anchor coating agent is applied to a support substrate layer, and an adhesive layer is melt-extruded, and (2) an anchor coating agent is applied to a support substrate. Material layer, and after the intermediate layer is melt-extruded, an extrusion lamination method of melt-extruding a sealant for an adhesive layer thereon is used, (3) an intermediate melt-extrusion excellent in adhesion to a supporting substrate is After the support substrate layer, an extrusion lamination method of melt-extruding the sealant with an adhesive layer thereon, (4) applying an anchor coating agent to the support substrate layer, and melting the intermediate layer and the adhesive layer at the same time Extrusion co-extrusion lamination method, (5) using an inflation molding method or a cast molding method in advance, forming a film containing at least one layer of sealant adhesive, and coating it with an anchor coating agent Dry lamination method in which the supporting substrate layers are bonded to each other, (6) the intermediate layer is melt-extruded by using extrusion lamination, and laminated on the supporting substrate layer coated with the anchor coating agent and containing at least one layer Extrusion lamination of a film of a sealant adhesive. On the other hand, as the coextrusion extrusion method, a coextrusion inflation method and a coextrusion T die method can be exemplified.

[Effect of the invention]

The adhesive for the sealant of the cover material of the container of the present invention is used as a cover material for an A-PET container which is excellent in moldability and can obtain high sealing strength, adhesion strength, and heat resistance, and is effective as a film for a cover material. of.

[Example]

Hereinafter, the present invention will be described more specifically based on examples. However, the present invention is not limited to these examples.

~ Mel flow rate (MFR) ~

The MFR of the ethylene-vinyl acetate copolymer (A) and the ethylene-vinyl acetate copolymer (B) was measured according to JIS K 6924-1.

About the adhesive agent for sealants obtained by the Example, the moldability was evaluated by the method shown below.

~ Molding stability ~

Using an extrusion laminator (manufactured by PLACO Co., Ltd., with a screw diameter of 25 millimeters φ), the adhesive pellets of the present invention were extruded and laminated at a processing temperature of 230 ° C. to obtain an adhesive for sealants. The thickness of the film is 25 microns. The film thickness after lamination was judged to be good if there was no variation of 3 μm or more (Δ and ○).

○: The molten film has no vibration and shaking, and the thickness deviation is less than 3 micrometers. △: Although the molten film has vibration and shaking, the thickness deviation is less than 3 micrometers. ╳: The molten film has vibration and shaking, and the thickness deviation is 5 micrometers or more.

~ Releasability ~

Using an extrusion laminator (manufactured by PLACO Co., Ltd., with a screw diameter of 25 millimeters φ), the adhesive particles of the present invention were extruded and laminated at a processing temperature of 230 ° C. to form a sealant with a thickness of 25 μm. The adhesive was evaluated for releasability of a matte roll for cooling. When the surface of the film was not separated from the roll, it was judged to be good (表面).

○: No peeling marks, ╳: Peeling marks

With respect to the film for a cover material obtained according to the examples, the sealing strength and the adhesive strength were evaluated by the methods described below.

~ Measurement of seal strength ~

Using a cup mouth sealer (manufactured by Sunny Cup, model UF-500), the adhesive surface of the film and the A-PET cup (215 ml in volume) were overlapped with each other at 160 ° C, 40 kgf / cup, and 1 second. , Followed by heating under pressure. After cooling, a seal tester (manufactured by Sun Chemical Co., Ltd. model FKT-100J) was used to measure the burst strength under the condition of an air injection amount of 0.8 liters / minute. 25 kPa or more was judged to be good.

○: 25kPa or more, ╳: less than 25kPa

~ Measurement of strength ~

The heat-sealing tester (Tester Industries, Model TP-701) was used to overlap the adhesive surface of the film with A-PET sheet (manufactured by Polytech) at 160 ° C, 0.2 MPa, and 1 second. , Followed by heating under pressure. After cooling, the adhesion strength was measured under the conditions of a peeling angle of 180 degrees and a peeling speed of 300 m / min. A width of 10 N / 15 mm or more was judged to be good.

○: 10N / 15mm or more, ╳: less than 10N / 15mm

Example 1

40 parts by weight of a resin (A1) (manufactured by Tosoh Corporation, trade name ultrathene 537) having a vinyl acetate content of 6% and a melt mass flow rate of 8.5 g / 10 minutes as an ethylene-vinyl acetate copolymer ( A). 40 parts by weight of a resin (B1) (manufactured by Tosoh Corporation, trade name ultrathene 626) having a vinyl acetate content of 15% and a melt mass flow rate of 3.0 g / 10 minutes as an ethylene-vinyl acetate copolymer ( B). 20 parts by weight of a partially hydrogenated petroleum resin (C1) (manufactured by Arakawa Chemical Co., Ltd. under the trade name ARKON M115, with a softening temperature of 115 ° C and a hydrogenation rate of about 60% (NMR method)) as a tackifier resin (C ). After mixing in advance with a stirrer, it was melt-kneaded at 180 ° C using a biaxial extruder to obtain pellets of an adhesive for a sealant. The difference between the vinyl acetate content of the ethylene-vinyl acetate copolymer (A1) and the vinyl acetate content of the ethylene-vinyl acetate copolymer (B1) was 9% by weight. In addition, considering the thermal stability of the adhesive for sealants, 0.05 parts by weight of a phenolic antioxidant (manufactured by BASF, Inc., trade name Irganox 1010) was added to 100 parts by weight of the adhesive for sealants. ), 0.2 parts by weight of a slip agent (manufactured by Lion Akzo Co., Ltd., trade name Irmowax E).

The MFR of the obtained adhesive for sealants was 15 g / 10 minutes.

Then, a low-density polyethylene (25 micrometers in thickness, manufactured by Tosoh Corporation) was used as an intermediate layer in a biaxially stretched polyester film (12 micrometers in thickness) as a supporting substrate layer. The product name is Petrocene 203), and an extruder laminator (manufactured by PLACO Co., Ltd., with a screw diameter of 25 millimeters φ) was used on the low-density polyethylene surface of the obtained multilayer film at a processing temperature of 230 ° C The adhesive particles of the present invention were extruded and laminated to obtain a film for a cover material of an adhesive layer for a sealant having a thickness of 25 μm.

Table 3 shows the evaluation results of the obtained adhesive for a sealant and a film for a cover material.

Example 2

40 parts by weight of the ethylene-vinyl acetate copolymer (A1) was replaced with 35 parts by weight of the ethylene-vinyl acetate copolymer (A1). 40 parts by weight of the ethylene-vinyl acetate copolymer (B1) was replaced with 35 parts by weight of the ethylene-vinyl acetate copolymer (B1). 30 parts by weight of completely hydrogenated petroleum resin (C2) (made by Arakawa Chemical Co., Ltd., trade name ARKON P125, softening temperature of 125 ° C, and hydrogenation rate of about 95% (NMR method)) were used to replace 20 parts by weight of the part Hydrogenated petroleum resin (C1) was used as the tackifier resin (C). As the ethylene · α-olefin copolymer (D), 40 parts by weight of an ethylene · α-olefin copolymer (D1) having a density of 860 kg / m 3 (manufactured by Mitsui Chemicals, Inc., trade name TAFMERP-0375) was used. . Except for the above, an adhesive for a sealant and a film for a cover material were obtained in the same manner as in Example 1. The difference between the vinyl acetate content of the ethylene-vinyl acetate copolymer (A1) and the vinyl acetate content of the ethylene-vinyl acetate copolymer (B1) was 9% by weight.

The formulation of the adhesive is shown in Table 1. The MFR of the obtained adhesive for sealants was 9 g / 10 minutes.

Table 3 shows the evaluation results of the obtained adhesive for a sealant and a film for a cover material.

Example 3

Replace 35 with 35 parts by weight of ethylene-vinyl acetate copolymer (B2) (manufactured by Tosoh Corporation, trade name ultrathene 541) with a vinyl acetate content of 10 parts and a melt mass flow rate of 9.0 g / 10 minutes. Ethylene-vinyl acetate copolymer (B1) by weight. As the tackifier resin (C), 30 parts by weight of the partially hydrogenated petroleum resin (C1) was replaced with 30 parts by weight of the fully hydrogenated petroleum resin (C2). 40 parts by weight of an ethylene‧α-olefin copolymer (D2) (manufactured by Tosoh Corporation, trade name: LUMITAC BF300R) with a density of 885 kg / m3 was used in place of 40 parts by weight of an ethylene · α-olefin copolymer ( D1). Except for the above, an adhesive for a sealant and a film for a cover material were obtained in the same manner as in Example 2. The difference between the vinyl acetate content of the ethylene-vinyl acetate copolymer (A1) and the vinyl acetate content of the ethylene-vinyl acetate copolymer (B1) was 4% by weight.

The formulation of the adhesive is shown in Table 1. The MFR of the obtained adhesive for sealants was 13 g / 10 minutes.

Table 3 shows the evaluation results of the obtained cover film.

Example 4

35 parts by weight of the ethylene-vinyl acetate copolymer (A1) was replaced with 40 parts by weight of the ethylene-vinyl acetate copolymer (A1). 35 parts by weight of the ethylene-vinyl acetate copolymer (B2) was replaced with 40 parts by weight of the ethylene-vinyl acetate copolymer (B2). 20 parts by weight of partially hydrogenated petroleum resin (C3) (manufactured by Arakawa Chemical Co., Ltd. under the trade name ARKON M135, softening temperature of 135 ° C, and hydrogenation rate of about 60% (NMR method)) were used to replace 30 parts by weight of Hydrogenated petroleum resin (C1) was used as the tackifier resin (C). 20 parts by weight of the ethylene · α-olefin copolymer (D2) was replaced with 40 parts by weight of the ethylene · α-olefin copolymer (D2). Except for the above, an adhesive for a sealant and a film for a cover material were obtained in the same manner as in Example 3. The difference between the vinyl acetate content of the ethylene-vinyl acetate copolymer (A1) and the vinyl acetate content of the ethylene-vinyl acetate copolymer (B1) was 4% by weight.

The formulation of the adhesive is shown in Table 1. The MFR of the obtained adhesive for sealants was 10 g / 10 minutes.

Table 3 shows the evaluation results of the obtained adhesive for a sealant and a film for a cover material.

Example 5

As the tackifier resin (C), 20 parts by weight of the partially hydrogenated petroleum resin (C1) was replaced with 20 parts by weight of the partially hydrogenated petroleum resin (C3). 20 parts by weight of the ethylene · α-olefin copolymer (D2) was replaced with 0 parts by weight of the ethylene · α-olefin copolymer (D2). As a thermoplastic block copolymer (E) of vinyl aromatic hydrocarbon and diene, 5 parts by weight of a thermoplastic aromatic block copolymer of vinyl aromatic hydrocarbon and diene (Kraton G1726MS) The thermoplastic block copolymer (E1) has a melt flow rate of 65 g / 10 minutes at 200 ° C and a load of 5.0 kg. Hydrogenated styrene-butadiene-diblock copolymer and hydrogenated styrene-butadiene The mixing ratio of the -styrene-triblock copolymer was 7/3, and the styrene content was 30% by weight. Except for the above, an adhesive for a sealant and a film for a cover material were obtained in the same manner as in Example 4. The difference between the vinyl acetate content of the ethylene-vinyl acetate copolymer (A1) and the vinyl acetate content of the ethylene-vinyl acetate copolymer (B1) was 4% by weight.

The formulation of the adhesive is shown in Table 1. The MFR of the obtained adhesive for sealants was 24 g / 10 minutes.

Table 3 shows the evaluation results of the obtained adhesive for a sealant and a film for a cover material.

Example 6

40 parts by weight of the ethylene-vinyl acetate copolymer (A1) was replaced with 35 parts by weight of the ethylene-vinyl acetate copolymer (A1). 40 parts by weight of the ethylene-vinyl acetate copolymer (B2) was replaced with 35 parts by weight of the ethylene-vinyl acetate copolymer (B2). 30 parts by weight of the partially hydrogenated petroleum resin (C1) was replaced with 20 parts by weight of the partially hydrogenated petroleum resin (C1). 40 parts by weight of the ethylene · α-olefin copolymer (D2) was replaced with 0 parts by weight of the ethylene · α-olefin copolymer (D2). The thermoplastic block copolymer (E1) of vinyl aromatic hydrocarbon and diene was replaced with 2 parts by weight of the thermoplastic block copolymer (E1) of vinyl aromatic hydrocarbon and diene. Except for the above, an adhesive for a sealant and a film for a cover material were obtained in the same manner as in Example 5. The difference between the vinyl acetate content of the ethylene-vinyl acetate copolymer (A1) and the vinyl acetate content of the ethylene-vinyl acetate copolymer (B1) was 4% by weight.

The formulation of the adhesive is shown in Table 1. The MFR of the obtained adhesive for sealants was 13 g / 10 minutes.

Table 3 shows the evaluation results of the obtained adhesive for a sealant and a film for a cover material.

Comparative Example 1

40 parts by weight of the ethylene-vinyl acetate copolymer (A1) was replaced with 80 parts by weight of the ethylene-vinyl acetate copolymer (A1). 40 parts by weight of the ethylene-vinyl acetate copolymer (B1) were replaced with 0 parts by weight of the ethylene-vinyl acetate copolymer (B1). Except for the above, an adhesive for a sealant and a film for a cover material were obtained in the same manner as in Example 1.

The formulation of the adhesive is shown in Table 2. The MFR of the obtained adhesive for sealants was 23 g / 10 minutes.

Table 4 shows the evaluation results of the obtained adhesive for a sealant and a film for a cover material.

The obtained cover material film was inferior in adhesive strength and sealing strength.

Comparative Example 2

Replace 35 with 35 parts by weight of an ethylene-vinyl acetate copolymer (B2) (manufactured by Tosoh Corporation, trade name ultrathene 751) with a vinyl acetate content of 28% and a melt mass flow rate of 5.7 g / 10 minutes. Ethylene-vinyl acetate copolymer (B1) by weight. Except for the above, an adhesive for a sealant and a film for a cover material were obtained in the same manner as in Example 2. The difference between the vinyl acetate content of the ethylene-vinyl acetate copolymer (A1) and the vinyl acetate content of the ethylene-vinyl acetate copolymer (B1) was 22% by weight.

The formulation of the adhesive is shown in Table 1. The MFR of the obtained adhesive for sealants was 23 g / 10 minutes.

Table 4 shows the evaluation results of the obtained adhesive for a sealant and a film for a cover material.

The obtained adhesive had poor molding process stability and inferior mold release properties, and therefore, a film for a cover material could not be obtained.

Comparative Example 3

20 parts by weight of the ethylene-vinyl acetate copolymer (A1) was used in place of 40 parts by weight of the ethylene-vinyl acetate copolymer (A1). 40 parts by weight of the ethylene-vinyl acetate copolymer (B1) was replaced with 20 parts by weight of the ethylene-vinyl acetate copolymer (B2). 60 parts by weight of the partially hydrogenated petroleum resin (C1) was replaced with 20 parts by weight of the partially hydrogenated petroleum resin (C1). Except for the above, an adhesive for a sealant and a film for a cover material were obtained in the same manner as in Example 1. The difference between the vinyl acetate content of the ethylene-vinyl acetate copolymer (A1) and the vinyl acetate content of the ethylene-vinyl acetate copolymer (B1) was 4% by weight.

The formulation of the adhesive is shown in Table 1. The MFR of the obtained adhesive for sealants was 70 g / 10 minutes.

Table 2 shows the evaluation results of the obtained adhesive for a sealant and a film for a cover material.

The obtained adhesive was inferior in mold release property, and the sealing strength of the film for a cover material was inferior.

Claims (8)

    An adhesive for a container lid material sealant, comprising 10 to 50 parts by weight of a vinyl acetate content of 3 to 15% by weight of an ethylene-vinyl acetate copolymer (A), and 10 to 50 parts by weight of a vinyl acetate content 8 to 25% by weight of ethylene-vinyl acetate copolymer (B) and 5 to 40 parts by weight of tackifier resin (C) (100 parts by weight in total for (A), (B), and (C)) , Where the difference between the vinyl acetate content of the ethylene-vinyl acetate copolymer (A) and the vinyl acetate content of the ethylene-vinyl acetate copolymer (B) is 3 to 20% by weight, and the ethylene-vinyl acetate copolymer ( The vinyl acetate content of A) is smaller than the vinyl acetate content of the ethylene-vinyl acetate copolymer (B).     The adhesive for the lid material sealant of a container according to item 1 of the scope of the patent application, wherein 10 to 50 parts by weight of ethylene‧α-olefin is mixed with 100 parts by weight of the adhesive for the lid material sealant of the container. The density of the copolymer (D) and ethylene · α-olefin copolymer (D) measured in accordance with JIS K 6922-1 (1998) is in the range of 860 to 910 kg / m ³ .     The adhesive for a lid material sealant of a container according to any one of claims 1 to 3, wherein 0.5 to 5 parts by weight is mixed with respect to 100 parts by weight of the adhesive for a lid material sealant of a container. Thermoplastic block copolymers (E) of vinyl aromatic hydrocarbons and olefins or dienes.         The adhesive for the sealant of the lid material of a container according to any one of claims 1 to 5, wherein the tackifier resin (C) is selected from the group consisting of aliphatic petroleum resins, aromatic petroleum resins, and cycloaliphatic resins. At least one of the group consisting of hydrogenated petroleum resin and copolymerized petroleum resin is partially hydrogenated at 50 to 90%.         Adhesives for sealing materials of lid materials of containers as described in item 1 or 2 of the scope of patent application, wherein the ethylene · α-olefin copolymer (D) satisfies the following conditions (a) to (c): (a) weight average The ratio (Mw / Mn) of the molecular weight (Mw) to the number-average molecular weight (Mn) is 3 or less. (B) The temperature (Tm (° C) of the maximum peak position of the endothermic curve obtained by the differential scanning calorimeter in the temperature measurement measurement. )) And the number of short chain branches (SCB) per 1,000 carbon atoms obtained from the measurement of the infrared absorption spectrum satisfy the relationship Tm <-1.8 * SCB + 140 (1) (c) α- The olefin has a carbon number of 3 or more and 12 or less.         The adhesive for a sealant for a lid material of a container according to any one of claims 1 to 4, wherein the thermoplastic block copolymer (E) of a vinyl aromatic hydrocarbon and an olefin or a diolefin is hydrogenated styrene- A mixture of a butadiene-diblock copolymer and a hydrogenated styrene-butadiene-styrene-triblock copolymer. The mixing ratio of the mixture is 5/5 ~ 9/1, and the styrene content is 20 ~ 50. weight%.         The adhesive for a lid material of a container according to any one of claims 1 to 6 of the scope of application for a patent, wherein the container has polyethylene terephthalate as a main component.         A film for a lid material of a container, comprising a layer comprising an adhesive for a lid material sealant of a container according to any one of claims 1 to 7 and at least two layers supporting a base material layer .