KR20070112146A - Ethylene copolymer composition and easily breakable sealing material using same - Google Patents

Abstract

Disclosed is an ethylene copolymer composition suitable as a sealing material for hydrocarbon polymers such as polypropylenes and polystyrenes. Also disclosed is an ethylene copolymer composition which forms a sealing material having excellent sealing performance, low-temperature heat sealing performance and seal breakability for hydrocarbon polymers while exhibiting sufficient antifogging properties. Further disclosed is an easily breakable sealing material composed of such a copolymer composition. Specifically disclosed is an ethylene copolymer composition containing 40-98 parts by weight of an ethylene/unsaturated ester copolymer (A), 60-0 parts by weight of an elastomer (B), 30-0 parts by weight of a crystalline polyolefin (C) (the total amount of (B) and (C) is 2-60 parts by weight) and 0-30 parts by weight of a tackifier (D). In a preferable mode of such an ethylene copolymer composition, the content of unsaturated ester unit in the ethylene copolymer (A) is 3-30% by weight, and the melting point (T °C) and the content of unsaturated ester unit (X mol%) satisfy the following formula :-3.0X + 125 >= T >=-3.0X + 109.

Description

ETHYLENE COPOLYMER COMPOSITION AND EASILY BREAKABLE SEALING MATERIAL USING SAME

This invention relates to the ethylene copolymer composition which shows the outstanding sealing property and ease of opening with respect to various materials, and the easily openable sealing material which consists of this composition. More specifically, it is related with the antifogging ethylene copolymer composition suitable for sealing materials of hydrocarbon type polymers, such as polypropylene and polystyrene, and the easily openable sealing material which consists of the composition.

As containers for various foods and medicines such as cup noodles, jelly, yogurt, and tofu, plastic containers with easy-opening lids are widely used. Various types of seal materials that can be extruded and laminated used for the seal layer of such easy-opening lid materials have been proposed and put into practical use. For example, the composition of ethylene vinyl acetate copolymer and tackifying resin, the composition which mix | blended polyethylene, a low crystalline ethylene-alpha-olefin copolymer, etc. to this becomes a sealing material provided with sealing property and easy opening. This is known (for example, refer patent document 1-2).

However, the kind of plastic material used for a container main body increases, too, and with respect to a new material, the conventional seal material may not fully correspond, and the appearance of a new seal material is desired. In addition, even in a container using an existing plastic material, desired heat seal properties are different depending on the use, and other properties may be required, and a seal material that can withstand such demands is also desired.

For example, polyethylene, polypropylene, polystyrene, polyester, and the like have been used for a long time as a container material, but in many cases, seal materials suited to the container material have been individually selected and used. By the way, in recent years, there is a strong demand for cost down, and there is a demand for a seal material that can be commonly used for various container materials. In particular, although the use of the container of polypropylene and polystyrene is increasing from cost and other characteristics, the easily openable sealing material which can be used in common is required.

By the way, in this kind of easy-opening sealing material, evaluation is centered on heat seal strength conventionally, and since the antifogging property is not required for a seal layer, the examination which paid attention to antifogging property has not been considered. By the way, the lid | cover material is generally comprised by sealing material laminated | stacked on the whole base material of a lid | cover material, and when used in containers, such as food-drinks, etc., when it is stored in the refrigerator, the cloudiness may generate in parts other than a seal part. In this case, there is a problem that the contents are hard to be seen in the transparent container, which makes the impression of the consumer worse.

Therefore, when trying to solve this problem by mix | blending an antifog additive to a seal material, when an antifog effect is not recognized depending on a seal material, it may adversely affect seal performance, and it has the outstanding seal performance and antifogging property The development of seal materials was not necessarily easy

Patent Document 1: JP 63-29894

Patent Document 2: Japanese Patent Application Laid-Open No. 1-3895

Disclosure of the Invention

Problems to be Solved by the Invention

An object of the present invention is to provide an ethylene copolymer composition excellent in sealing property, low temperature heat sealing property, and easy opening in a variety of materials, especially hydrocarbon-based polymers such as polypropylene and polystyrene.

Further, another object of the present invention is ethylene, which is a sealing material that exhibits excellent sealing property, low temperature heat sealing property, easy opening, and sufficient antifogging property with respect to various materials, especially hydrocarbon-based polymers such as polypropylene and polystyrene. It is to provide a copolymer composition.

Another object of the present invention is to provide an easily openable seal material using such an ethylene copolymer composition and a packaging material obtained by laminating such a seal material on a substrate.

Means to solve the problem

40 to 98 parts by weight of the ethylene-unsaturated ester copolymer (A), 60 to 0 parts by weight of the elastomer (B) and 30 to 0 parts by weight of the crystalline polyolefin (C) (however, the total amount of (B) and (C) is 2 ˜60 parts by weight) and (D) 0-30 parts by weight of a tackifier, provided that the total amount of (A), (B), (C) and (D) is 100 parts by weight]. to provide.

In the present invention, the ethylene-unsaturated ester copolymer (A) further has an unsaturated ester unit content of 3 to 30% by weight, a melting point (T ° C) (based on JIS K7121) and an unsaturated ester unit content (X mol%). The said ethylene copolymer composition which is an ethylene- unsaturated unsaturated copolymer (A) which satisfy | fills this following formula is provided.

-3.0X + 125 ≥ T ≥ -3.0X + 109

Moreover, this invention provides the ethylene copolymer composition which the said ethylene copolymer composition mix | blended up to 10 weight part antifogging agent (E) with respect to 100 weight part of polymer components in an ethylene copolymer composition.

This invention provides the easily openable sealing material which consists of the ethylene copolymer composition of this invention. The easy-opening sealing material of the present invention can be suitably used for sealing in hydrocarbon-based polymers and the like.

According to this invention, the packaging material formed by laminating | stacking the said easily opening sealing material on a base material is also provided.

Effects of the Invention

Advantageous Effects of Invention The present invention can provide an easy-opening sealing material having moderate heat seal strength, low temperature dependence of heat seal strength, and heat seal at low temperature with respect to hydrocarbon polymers such as polypropylene and polystyrene. .

Advantageous Effects of Invention The present invention can provide an easy-opening sealing material having moderate heat seal strength, low temperature dependence of heat seal strength, and heat seal at low temperature with respect to hydrocarbon polymers such as polypropylene and polystyrene. .

Such easy opening seal material can be used as a heat-seal film to a hydrocarbon type polymer by laminating | stacking in a single layer or a base material. Moreover, it can laminate | stack on a base material and can be used as a lid | cover material, such as a hydrocarbon type polymer container. In particular, when used as a packaging material for food and drink, it is excellent in anti-fogging properties, so that even when stored in the refrigerator, there is no blur and no damage to the product image.

Best Mode for Carrying Out the Invention

The present invention is antifogging to 100 parts by weight of a polymer component composed of 40 to 95 parts by weight of an ethylene-unsaturated ester copolymer (A), 60 to 5 parts by weight of an elastomer (B) and 30 to 0 parts by weight of a crystalline polyolefin (C). The ethylene copolymer composition obtained by mix | blending agent (D) in the ratio of 0.01-10 weight part is provided.

As the ethylene-unsaturated ester copolymer (A), the unsaturated ester unit content is 3 to 30% by weight, particularly 4 to 25, in consideration of the seal strength, the degree of stickiness to the hydrocarbon-based polymer, or oil resistance in food packaging applications. The range of weight% is suitable. Examples of the unsaturated ester of the ethylene-unsaturated ester copolymer (A) include vinyl acetate and vinyl esters such as vinyl propionate, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-propyl acrylate, isobutyl acrylate, n-butyl acrylate and methacryl Unsaturated carboxylic acid esters such as methyl acid, ethyl methacrylate, isobutyl methacrylate, dimethyl maleate, and diethyl maleate. Especially preferred unsaturated esters are lower alkyl esters of vinyl acetate and acrylic acid or methacrylic acid. An ethylene-unsaturated ester copolymer (A) can be used in mixture of 2 or more types.

The ethylene-unsaturated ester copolymer (A) also has a melt flow rate (JlS K7210-1999) of 0.1 to 500 g / 10 minutes at 190 ° C and a load of 2160 g, particularly 0.5 to 150 g, in consideration of workability, seal strength, oil resistance, and the like. Preference is given to using / 10 minutes.

The ethylene-unsaturated ester copolymer (A) as described above can be obtained by radical copolymerization under high temperature and high pressure. For example, although the random good copolymer (A) manufactured by the high pressure radical polymerization process by a normal autoclave method can be used, the nonuniformity is higher than this, and compared with the thing of the same unsaturated ester unit content The copolymer (A) manufactured by the high pressure radical polymerization process by the Tubular method with a high melting point can be used especially suitably.

In the present invention, as the elastomer (B) blended into the ethylene-unsaturated ester copolymer (A), an amorphous or low-crystalline olefin copolymer or a styrene-based thermoplastic elastomer can be exemplified. As an amorphous or low-crystalline olefin copolymer, the crystallinity measured by X-ray diffraction method using 2 or more types of alpha-olefins of 2-10 carbon atoms as a component is 40% or less (0-40%), Preferably Is a copolymer of 7 to 30%, and has rubbery properties. Representative examples of the copolymer include ethylene or propylene as a main component, and copolymers having one or two or more kinds of other α-olefins having 2 to 10 carbon atoms as a minor component thereof.

As a copolymer having ethylene as a main component, 50 to 90 mol% of ethylene polymerized units, preferably 70 to 85 mol%, and 50 to 10 mol% of α-olefin polymerized units other than ethylene, preferably 30 to 15 mol % And, if necessary, those containing 2 mol% or less, preferably 1 mol% or less, of a diene monomer polymerization unit. As such an ethylene copolymer, an ethylene propylene copolymer, an ethylene 1-butene copolymer, an ethylene 4-methyl-1-pentene copolymer, an ethylene 1-hexene copolymer, an ethylene 1-octene copolymer, etc. It can be illustrated. Among these, especially an ethylene propylene copolymer or an ethylene 1-butene copolymer is preferable.

Moreover, the copolymer which has propylene as a main component has 70-95 mol% of propylene polymerized units, Preferably 72-90 mol%, and 5-30 mol% of polymerized units of alpha-olefins other than propylene, Preferably it is 10 It can illustrate what contains -28 mol%. As such a propylene copolymer, a propylene ethylene copolymer and a propylene 1-butene copolymer can be illustrated.

As the amorphous or low crystalline olefin copolymer, in consideration of moldability and miscibility with the copolymer (A), the melt flow rate (ASTM D-1238) measured at 230 ° C. and 2160 g load is 0.1 to 500 g. It is preferable to use / 10 minutes, especially 0.5-150 g / 10 minutes.

In the case of the copolymer having ethylene as a main component, the amorphous or low crystalline olefin copolymer is a metal such as a vanadium catalyst composed of a soluble vanadium compound and an organoaluminum halide, or a zirconium compound in which a cyclopentadienyl group or the like is coordinated. In the presence of a metallocene catalyst composed of a rosene compound and an organoaluminum oxy compound, it can be produced by copolymerizing ethylene and other α-olefins. Moreover, in the case of the copolymer which has propylene as a main component, the stereoregular olefin polymerization containing transition metal compound components, such as a highly active titanium catalyst component or a metallocene type catalyst component, an organoaluminum component, an electron donor, a carrier, etc. as needed In the presence of a catalyst, it can be produced by copolymerizing propylene with another α-olefin.

As the ethylene-unsaturated ester copolymer (A) of the present invention, the melting point (T ° C) (based on JIS K7121) by DSC is represented by the following formula in relation to the unsaturated ester unit content (X mol%).

-3.0X + 125 ≥ T ≥ -3.0X + 109

Copolymers satisfying the following are preferably used. In this invention, it is preferable that X exists in the range of 0.5-12.2. The ethylene-unsaturated ester copolymer (A) which satisfies this formula has a high nonuniformity compared with a normal random copolymer and has a high melting point as compared with that of the same unsaturated ester unit content. Such a copolymer can be manufactured by the multistage polymerization by the autoclave method or the tubular method, for example in the high pressure radical polymerization method. As an example of these manufacturing methods, the method introduced by each Unexamined-Japanese-Patent No. 62-273214 and Unexamined-Japanese-Patent No. 3423308 is mentioned.

As the elastomer (B) of the present invention, a styrenic thermoplastic elastomer can also be used. Examples of the styrene-based thermoplastic elastomers include those in which a polymer block (X) mainly composed of a styrene monomer, a block copolymer of a block (Y) mainly composed of a conjugated diene compound, and a conjugated diene polymerized unit of the block copolymer are hydrogenated. It can be illustrated. Although styrene, (alpha) -methylstyrene, vinyl toluene, t-butyl styrene, etc. can be illustrated here as a styrene monomer, Especially styrene is preferable. As the conjugated diene compound, butadiene, isoprene, chloroprene, 2,3-dimethyl butadiene and the like can be exemplified, but butadiene or isoprene is particularly preferable.

As a block copolymer of the polymer block (X) mainly having a styrene-type monomer, and the polymer block (Y) mainly having a conjugated diene compound, it is (XY) _n or (XY) _n- X (In formula, n is an integer greater than or equal to 1), linear, branched, radial block copolymers are mentioned. Typical examples thereof include a block copolymer having a styrene monomer polymer block of 10 to 60% by weight and a conjugated diene polymer block of about 90 to 40% by weight.

As the styrenic thermoplastic elastomer, one having as few olefinic double bonds as possible is preferable, and 70 of the conjugated diene polymerized unit of the block copolymer composed of a polymer block mainly composed of the styrene monomer and a polymer block mainly composed of the conjugated diene compound It is preferable that at least%, preferably at least 90%, be hydrogenated. More specifically, vinyl bonds such as 1,2- or 3,4- and the like in the polymer block mainly composed of the conjugated diene compound are 10% or more, preferably 20 to 80%, and even more preferably 30 to 60% of the block copolymer is a hydrogenated block copolymer having a hydrogenated styrene compound content of 8 to 50% by weight, preferably 10 to 40% by weight, for example, an X-Y'-X type block copolymer. Is optimal. Here, X is a styrene polymer block, and Y 'is a hydrogenated conjugated diene polymer block, ie, an alkylene copolymer block, specifically, an ethylene butene copolymer block or an ethylene propylene copolymer block. Such a block copolymer is obtained by hydrogenating butadiene polymer block or isoprene polymer block of styrene-butadiene-styrene block copolymer generally called SBS or styrene-isoprene-styrene block copolymer called SIS, and generally It is called SEBS or SEPS. As the thermoplastic styrene-based elastomer, it is preferable to use a melt flow rate (ASTM D1238) at a temperature of 200 ° C. and a 5 kg load of 0.1 to 500 g / 10 minutes, particularly 0.5 to 150 g / 10 minutes. These are, for example, Clayton 1101 (SBS), Clayton 1102 (SBS), Clayton 1107 (SIS), Clayton 4122 (SBS), Clayton G1651 (SEBS), Clayton G1652 (SEBS), Clayton Trade names, such as G1657 (SEBS), can be used.

The crystalline polyolefin (C) which can be used for the ethylene copolymer composition of the present invention is a homopolymer of olefins or copolymers of olefins having a degree of crystallinity of 40% or more in X-rays, specifically polyethylene of various densities, Polypropylene, poly-1-butene, poly-4-methyl-1-pentene and the like. In these, it is preferable to use a polyethylene, especially a linear low-density polyethylene, or to use a polypropylene.

The linear low-density polyethylene, will of ethylene with a carbon number of 3 or more, preferably a copolymer of an α- olefin of 3 to 12 and a density of 890 ~ 940kg / m ^3, preferably 900 ~ 93Okg / m ^3. These are single site catalysts such as a combination catalyst of a metallocene catalyst component composed of a zirconium compound having a ligand having a cyclopentadienyl skeleton and an organoaluminum oxy compound catalyst component, or a high active titanium catalyst component and an organoaluminum compound catalyst. In the presence of a multisite catalyst, such as a combination catalyst of components, ethylene and an α-olefin having at least 3 carbon atoms, such as propylene, 1-butene, l-pentene, 1-hexene, 1-octene, 1-decene, 1- It can manufacture by copolymerizing dodecene, 4-methyl-1- pentene, etc. In particular, linear low density polyethylene obtained using a single site catalyst is suitable. In consideration of the miscibility and workability with other components, it is preferable to use a melt flow rate (ASTM D1238) of 0.1 to 500 g / 10 minutes, particularly 0.5 to 150 g / 10 minutes at a load of 190 ° C and 2160 g. desirable.

The polypropylene suitable as the polyolefin (C) is a propylene homopolymer or a copolymer of propylene mainly composed of propylene and other α-olefins, and has a density of 870 to 930 kg / m ³ , particularly 880 to 920 kg / m ³ . desirable. Moreover, it is preferable that melt flow rate (ASTM D1238) in 230 degreeC and a 2160g load is 0.1-500g / 10min, especially 0.5-150g / 10min. As the α-olefin copolymerized with propylene in the copolymer of propylene, those having 2 to 12 carbon atoms, particularly those having 2 to 10 carbon atoms are preferable, and specifically, ethylene, 1-butene, 1-hexene, 1-octene, 1 1 type, or 2 or more types, such as -decene, 1-dodecene, 4-methyl-1- pentene, can be illustrated. It is preferable that content of the alpha olefin unit in such a propylene / alpha-olefin copolymer is 20 mol% or less, especially 0.1-15 mol%. The propylene copolymer may be a random copolymer or a block copolymer. These polypropylenes can be obtained by polymerizing or copolymerizing propylene in the presence of a stereoregular olefin polymerization catalyst.

The tackifying resin (D) which can be used for the ethylene copolymer composition of this invention is aliphatic hydrocarbon resin, alicyclic hydrocarbon resin, aromatic hydrocarbon resin, polyterpene resin, rosin, styrene resin, cumarone indene Resin and the like. As an example of an aliphatic hydrocarbon resin, resin obtained by superposing | polymerizing the oil component containing at least 1 sort (s) of C4-C5 mono or diolefin, such as 1-butene, isobutene, butadiene, 1, 3-pentadiene, and isoprene, is mentioned. Can be. As examples of the alicyclic hydrocarbon resin, Scotland pent C ₄ ~ C ₅ diene component cyclization 2 quantified the to the obtained resin, cyclopentadiene resin by polymerizing a cyclic monomer such as diene, aromatic hydrocarbon resin polymerization nucleus after hydrogenation of the fraction One resin etc. can be mentioned.

As examples of the aromatic hydrocarbon resins, vinyl toluene, indene, α- methyl styrene and so on in the C ₈ ~ resin obtained by polymerizing a fraction containing a vinyl aromatic hydrocarbon in the C ₁₀ at least one or more or these oil and the aliphatic hydrocarbon oil The resin etc. which are obtained by copolymerizing are mentioned. Examples of the polyterpene-based resins include α-pinene polymers, β-pinene polymers, dipentene polymers, terpene phenol copolymers, α-pinene phenol copolymers, and hydrogenated substances thereof.

Examples of the rosin include rosin such as gum rosin, wood rosin, tall oil and the like and modified substances thereof. Examples of the modified substance include modifications such as hydrogenation, disproportionation, dimerization, and esterification. As a styrene-type hydrocarbon resin, the dendritic polymer with low molecular weight obtained by superposing | polymerizing 1 type (s) or 2 or more types of styrene monomers, such as high purity styrene, vinyl toluene, (alpha) -methylstyrene, isopropyl toluene, is mentioned.

When the ethylene copolymer composition of the present invention is used as an easy-opening sealing material for food and beverage packaging, in consideration of odorlessness, food hygiene, and miscibility with other components, hydrocarbon resins such as aromatic hydrocarbon resins and terpene resins may be hydrogenated. It is preferable to use the added resin.

The blending ratio of the ethylene-unsaturated ester copolymer (A) in the ethylene copolymer composition of the present invention is 40 to 98 parts by weight, preferably 40 to 95 parts by weight, more preferably 50 to 90 parts by weight, elastomer The blending ratio of (B) is 60 to 0 parts by weight, preferably 60 to 2 parts by weight, more preferably 50 to 10 parts by weight, and the blending ratio of the crystalline polyolefin (C) is 30 to 0 parts by weight, Preferably the mixing ratio of 30 to 2 parts by weight, more preferably 20 to 5 parts by weight, and the tackifier (D) is preferably in the range of 0 to 30 parts by weight, but the total amount of (B) and (C) Is required to be 2 to 60 parts by weight. However, the total amount of (A), (B), (C) and (D) is 100 parts by weight].

In the ethylene copolymer composition of the present invention, up to 10 parts by weight with respect to 100 parts by weight of the total amount of the polymer components (A), (B) and (C) in the ethylene copolymer composition, preferably 0.01 to 10 parts by weight of an antifogging agent ( E) can be further compounded. By mix | blending an antifog additive, it is excellent in antifogging property, has moderate heat-sealing strength with respect to hydrocarbon polymers, such as polypropylene and polystyrene, has little temperature dependence of heat-sealing strength, and is easy to open seal material which can be heat-sealed at low temperature. Ethylene copolymer compositions enabling the provision of

As the antifogging agent (E), nonionic, anionic and cationic surfactants can be used. For example, polyoxyalkylene ether, partial ester of polyhydric alcohol, partial ester of alkylene oxide adduct of polyhydric alcohol, poly (oxyethylene) alkylamine, poly (oxyethylene) alkylamide, higher alcohol sulfate ester alkali metal salt, Alkyl aryl sulfonate, a quaternary ammonium salt, etc. are mentioned. More specifically, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene nonyl phenyl ether, polyethylene glycol monopalmitate, polyethylene glycol monostearate, polyoxyethylene sorbitan monolaurate, polyoxyethylene Sorbitan monopalmitate, glycerin monolaurate, glycerin monopalmitate, glycerin monostearate, glycerin monooleate, pentaerythritol monolaurate, sorbitan monopalmitate, sorbitan monobehenate, sorbitan monostearate, Sorbitan distearate, diglycerin monooleate, triglycerin dioleate, sodium lauryl sulfate, sodium dodecylbenzenesulfonate, sodium butylnaphthalenesulfonate, cetyltrimethylammonium chloride, trimethylbenzyl ammonium chloride, triethylcetyl ammonium iodide , Dode Silamine hydrochloride, lauric acid laurylamide ethyl phosphate, oleylaminodiethylamine hydrochloride, dodecylpyridinium sulfate, and the like. Among these, it is preferable to use nonionic surfactants, and in particular, esters of polyhydric alcohols, particularly fatty acid esters of polyhydric alcohols selected from polyethylene glycol, glycerin, diglycerine and sorbitan. These can be used together 2 or more types.

In the ethylene copolymer composition of this invention, various additives can be mix | blended arbitrarily. Representative examples of such additives include lubricants and / or roll agents used for the purpose of improving extrusion processability, rollability, sliding properties of films, and the like. More specifically, palmitic acid amide, stearic acid amide, behenic acid amide, oleic acid amide, ercarboxylic acid amide, oleyl palmitamide, stearyl palmimidamide, methylenebisstearylamide, methylenebisoleylamide, ethylenebis And various amides such as oleylamide and ethylene biserxamide, polyalkylene glycols such as polyethylene glycol and polypropylene glycol, inorganic additives such as hydrogenated castor oil, silica and talc. In the case of an inorganic additive, the compounding quantity in these compositions is 0 to 3 weight%, Preferably it is about 0.1 to 3 weight%, The other thing is 0 to 1 weight%, Preferably the range of about 0.01 to 1 weight% is It is suitable.

As an example of the other additive which can be mix | blended arbitrarily, tackifying resin, antioxidant, a heat stabilizer, a light stabilizer, a pigment, dye, etc. can be illustrated. Tackifying resin is useful for performing fine adjustment of the seal strength. As tackifying resin, aliphatic hydrocarbon resin, alicyclic hydrocarbon resin, aromatic hydrocarbon resin, polyterpene resin, rosin, styrene resin, coumarone-indene resin etc. are mentioned, for example. As an example of an aliphatic hydrocarbon resin, resin obtained by superposing | polymerizing the oil component containing at least 1 sort (s) of C4-C5 mono or diolefin, such as 1-butene, isobutene, butadiene, 1, 3-pentadiene, and isoprene, is obtained. Can be mentioned. Examples of the cycloaliphatic hydrocarbon resins include hydrogens in the core and aromatic hydrocarbon resins obtained by polymerizing cyclic monomers such as cyclopentadiene, resins obtained by cyclization and dimerization of the diene component in the Spent C ₄ to C ₅ fraction. Added resin etc. are mentioned.

The ethylene copolymer composition of this invention can be manufactured by mixing simultaneously or sequentially the component selected from said (A)-(E) according to this invention, and the other additive mix | blended as needed. In manufacturing an ethylene copolymer composition, it is preferable to melt-mix at 130-230 degreeC using a single screw extruder, a twin screw extruder, a Van Barry mixer, various kneaders, etc., and the mixing order in particular is limited. none.

The ethylene copolymer composition of the present invention thus obtained has a melt flow rate (JIS K7210-1999) of 1 to 400 g / 10 minutes, particularly 1 to 150 g /, at 190 ° C and a load of 2160 g in consideration of extrusion processability, seal strength, and the like. It is preferable to make it to about 10 minutes.

The ethylene copolymer composition of the present invention is suitable as an easy-opening sealing material for an easy-opening sealing material, in particular, an easy-opening sealing material for a packaging material, especially a hydrocarbon-based polymer such as polypropylene or polystyrene. When used for an easy-opening sealing material, it is usually used in a form laminated on various substrates. Examples of the substrate used for this purpose include paper, aluminum, polyester, polyethylene, polypropylene, (high impact) polystyrene, aluminum vapor deposition polyester, aluminum vapor deposition polypropylene, silica vapor deposition polyester, and the like. This base material does not need to be a single layer, but may be a laminate of two or more layers.

In order to laminate the ethylene copolymer composition of the present invention on the substrate, the composition is filmed in advance by the casting method or the inflation method, and the method is applied to the substrate by dry lamination method, the method of extrusion coating the composition directly on the substrate, A polyethylene or the like is used as an adhesive layer, and a method of laminating via an adhesive layer by sandwich lamination on a substrate, a method of coextrusion of the substrate and its composition, and the like can be employed.

The laminated body obtained in this way can be used with various packaging materials. In particular, when used as the lid | cover material of various containers, especially the container made from a polypropylene, and the container made from polystyrene, it becomes a lid | cover material excellent in antifogging property, sealing property, opening property, etc. Moreover, it can be used not only as the container of these hydrocarbon type polymers, but also as the lid | cover material of the container of other materials, for example, containers, such as polyester, a polycarbonate, and polyvinyl chloride. Such a container with a lid may be, for example, jelly, pudding, yogurt, mitsumame, sour, tofu, lactic acid beverage, Japanese confectionery, processed foods such as processed meat, medicine, medical container, toner, etc. Can be used for packaging.

Hereinafter, the present invention will be described in more detail with reference to Examples. In addition, the raw material used by the Example and the comparative example is as follows.

1. Raw material

(1) Ethylene-unsaturated ester copolymer (A)

EMA: Ethylene-methyl acrylate copolymer (Methyl acrylate unit content 20 weight%, Melt flow rate (190 degreeC, 2160g load, JIS K7210-1999) 8g / 10min, melting | fusing point 92 degreeC)

(2) Elastomer (B)

SEBS: Styrene ethylene / butene styrene block copolymer (brand name: Clayton G 1657, styrene polymer block 13 weight%, ethylene / butene polymer block 87 weight%, melt flow rate (200 degreeC, 5 kg, ASTM D1938) 8 g / 10 minutes)

(3) crystalline polyolefin (C)

(a) mPE-1: (trade name: a linear low density polyethylene prepared with a single site catalyst - EVO current SC 00l00, Mitsui Kagaku Ltd., density 9O2kg / m ^3, a melt flow rate (190 ℃, 2160g load, ASTM D1238 8 g / 10 minutes)

(b) mPE-2: straight chain low density polyethylene manufactured with a single site catalyst (trade name: Evory SP 0540, manufactured by Mitsui Chemicals, Density 9O3 kg / m ³ , melt flow rate (190 ° C., 2160 g load, ASTM D1238) 3.8g / 10min)

(c) PP: propylene ethylene 1-butene random copolymer (3.6 mol% (2.4 weight%) of ethylene unit content, 1.9 mol% (2.5 weight%) of 1-butene unit content, density 910 kg / m <^3> , melt flow Rate (230 ° C, 2160g Load, ASTM D1238) 6g / 10min)

(4) tackifying resin (D)

P115: Hydrogenated Aromatic Hydrocarbon Resin (Brand Name: Alcon AM1 (manufactured by Arakawa Chemical Industries, Ltd., Ring and Ball Softening Point 115 ° C))

(5) antifog (E)

Diglycerin fatty acid ester (brand name: Rickemal O-71-DE, made by Rickenvitamin Co., Ltd.)

[Examples 1-10, Reference Example]

Preparation of Ethylene Copolymer Composition

Each component is melt-kneaded at 150 degreeC using a single screw extruder by the compounding composition ratio shown in Table 1, and a composition is manufactured.

Next, the ethylene copolymer composition of the compounding composition shown in Table 1 is 30 by extrusion lamination on the polyethylene film surface side of the laminated | multilayer film which consists of stretched PET (12 micrometers in thickness) / low density polyethylene (20 micrometers in thickness) previously prepared It laminated | stacked to the thickness of micrometer, and obtained the test base material.

The test substrate was superimposed on a polypropylene sheet or polystyrene sheet having a thickness of 300 µm so that the ethylene copolymer composition surface abuts, and heat-sealed under the conditions of a temperature of 120 ° C, 140 ° C and 160 ° C, a pressure of 0.2 MPa, and a sealing time of 1.0 second. A laminate was obtained. The peeling strength at the time of peeling a test base material part from this laminated body was measured. These results are written together in Table 1.

[Examples 11 to 12 and Comparative Example 1]

Preparation of Ethylene Copolymer Composition

Each component was melt-kneaded at 150 degreeC using the single screw extruder by the compounding composition ratio shown in Table 2, and the composition was produced.

Next, by extrusion lamination, the ethylene copolymer composition having the blending composition shown in Table 2 is placed on the polyethylene film surface side of the laminated film of the two-layered constitution consisting of drawn PET (thickness 12 μm) / low density polyethylene (thickness 20 μm) prepared in advance. It laminated | stacked to the thickness of micrometer, and obtained the test base material. The anti-fogging property when this test base material was stored at 5 degreeC for 1 week in the refrigerator was visually evaluated.

○: no blur

×: cloudy

Furthermore, this test base material is laminated | stacked on the polystyrene sheet of thickness 300micrometer so that the surface of the ethylene copolymer composition may abut, and it heat-seals on conditions of the temperature of 120 degreeC, 140 degreeC, and 160 degreeC, the pressure of 0.2 MPa, and the sealing time of 1.0 second, and a laminated body. Got. The peeling strength at the time of peeling a test base material part from this laminated body was measured. These results are written together in Table 2.

[Examples 13-14, Comparative Example 2]

Except having used the ethylene copolymer composition of the compounding composition shown in Table 3, the test base material was produced by the method similar to Example 11, and the antifogging property was evaluated. In addition, except using this test base material and using the polypropylene sheet instead of the polystyrene sheet, the laminated body was produced by heat-sealing similarly to Example 11, and peeling strength was similarly measured. We write result in Table 3 together

ADVANTAGE OF THE INVENTION According to this invention, the easily openable sealing material which has moderate heat seal strength, little temperature dependence of heat seal strength, and is heat sealable at low temperature with respect to hydrocarbon polymers, such as polypropylene and polystyrene, is provided.

According to the present invention, it is also excellent in anti-fogging property, has a moderate heat seal strength, less temperature dependence of the heat seal strength to hydrocarbon-based polymers such as polypropylene and polystyrene, easy to open seal that can be heat sealed at low temperature Material is provided.

Such easy-opening sealing material can be used as a heat-seal film for hydrocarbon-based polymers by laminating in a single layer or on a substrate. Moreover, it can laminate | stack on a base material and can be used for lid materials, such as a hydrocarbon type polymer container. In particular, when used as a packaging material for food and drink, it is excellent in anti-fogging properties, so that even when stored in the refrigerator, there is no blur and no damage to the product image.

Claims (11)

40-98 weight part of ethylene-unsaturated ester copolymers (A), 60-0 weight part of elastomers (B), and 30-O weight part of crystalline polyolefin (C) (However, the total amount of (B) and (C) is 2 ˜60 parts by weight) and (D) 0 to 30 parts by weight of a tackifier, provided that the total amount of (A), (B), (C) and (D) is 100 parts by weight]. The method of claim 1, As for the said ethylene unsaturated unsaturated copolymer (A), the unsaturated ester unit content is 3-30 weight%, melting | fusing point (T degreeC) (based on JIS K7121), and unsaturated ester unit content (X mol%) are a following formula. Ethylene copolymer composition which is a satisfying ethylene-unsaturated ester copolymer (A). -3.0X + 125 ≥ T ≥ -3.0X + 109 The method according to claim 1 or 2, Ethylene copolymer composition in which an ethylene unsaturated unsaturated copolymer (A) is an ethylene methyl acrylate copolymer. The method according to any one of claims 1 to 3, Ethylene copolymer composition wherein the elastomer (B) is selected from amorphous or low crystalline olefin copolymers and styrene-based thermoplastic elastomers. The method according to any one of claims 1 to 4, Ethylene copolymer composition whose tackifying resin (D) is a hydrogenated hydrocarbon resin. The method according to any one of claims 1 to 5, Ethylene copolymer composition wherein the crystalline polyolefin (C) is polypropylene or straight chain low density polyethylene. The method according to any one of claims 1 to 6, The ethylene copolymer composition in which the said ethylene copolymer composition mix | blends up to 10 weight part antifogging agent (E) with respect to 100 weight part of polymer components in an ethylene copolymer composition further. The method of claim 7, wherein The ethylene copolymer composition whose antifog additive is ester of a polyhydric alcohol. The easy-opening sealing material which consists of the ethylene copolymer composition of any one of Claims 1-8. The method of claim 9, Easily openable seal material for sealing to hydrocarbon polymers. The packaging material in which the easily openable sealing material of Claim 9 or 10 is laminated | stacked on the base material.