JP2002338767A - Heat seal material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat seal material which is excellent in low-temperature heat sealability (seal strength, flexural resistance) and in oxygen barrier properties and perfume retention. SOLUTION: The heat seal material contains a saponified ethylene-vinyl acetate copolymer and a polyamide resin having a melting point of 160 deg.C or lower.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a heat seal material using a saponified ethylene-vinyl acetate copolymer (hereinafter abbreviated as EVOH).

[0002]

2. Description of the Related Art In general, EVOH is excellent in transparency, gas barrier property, fragrance retention, solvent resistance, oil resistance and the like.
It is used for various packaging materials such as industrial chemical packaging materials and agricultural chemical packaging materials. In such various applications of the packaging material, the films are often used by being sealed by heat sealing, and the heat sealing property of the packaging material is also an important required performance.

However, it is known that EVOH is inferior in heat sealability to thermoplastic resins such as polyolefin resins and polystyrene resins. As a countermeasure, it has been proposed to blend other resins with EVOH. Have been. For example, Japanese Patent Application Laid-Open No. 2000-248124 discloses a blend of EVOH, a polyamide, an ionomer, and a polyolefin. The present applicant also discloses a blend of EVOH and a partially saponified ethylene-vinyl acetate copolymer ( JP-A-60-145441) or a blend of EVOH and re-acetylated EVOH (JP-A-2
000-248124).

[0004]

However, the above-mentioned blend of EVOH, polyamide, ionomer and polyolefin has good heat sealing properties, but contains a polyamide having a relatively high melting point. If it is low, sufficient heat sealing properties cannot be exhibited, and when made into a bag or the like, gas peeling properties and fragrance retention may be greatly reduced due to minute peeling of the heat seal bonding part during bending fatigue. is there. Also, EV
Although a blend of OH and a partially saponified ethylene-vinyl acetate copolymer has sufficient heat sealability, there is still room for improvement in the fragrance retention and gas barrier properties required from recent markets. In addition, a blend of EVOH and re-acetated EVOH is economically disadvantageous in production, and its use may be limited by a small amount of acetic acid odor, and further improvement of any blend is desired. It is about to be done.

[0005]

Accordingly, the present inventor has conducted intensive studies in view of the present situation, and as a result, has found that EVOH
The present invention has been completed in which it has been found that a heat sealing material containing (A) and a polyamide resin (B) having a melting point of 160 ° C. or less can solve the above problems.
In the present invention, it is preferable to further contain boron or the boron compound (C), since the effects of the present invention can be remarkably obtained.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

The EVOH (A) used in the present invention is not particularly limited, but has an ethylene content of 10 to 70.
Mol% (furthermore, 20 to 60 mol%, especially 25 to 50 mol%), and a saponification degree of 90 mol% or more (furthermore, 95 mol%
When the ethylene content is less than 10 mol%, the gas barrier properties and melt moldability at high humidity are reduced. On the contrary, when the ethylene content exceeds 70 mol%, a sufficient gas barrier property is obtained. When the saponification degree is less than 90 mol%, the gas barrier properties, thermal stability, moisture resistance, etc. are undesirably reduced.

The EVOH has a melt flow rate (MFR) (210 ° C., load 2160 g) of 0.5 to 0.5.
100 g / 10 min (more preferably 1 to 50 g / 10 min, particularly 3 to 35 g / 10 min) is preferred. If the MFR is smaller than the above range, the extruder becomes in a high torque state during molding and extrudes. If the processing becomes difficult, and if it is larger than the above range, the thickness accuracy of the obtained heat sealing material may be undesirably reduced.

The EVOH (A) is obtained by saponifying an ethylene-vinyl acetate copolymer. The ethylene-vinyl acetate copolymer can be produced by any known polymerization method, for example, solution polymerization, suspension polymerization, It is produced by emulsion polymerization or the like, and saponification of an ethylene-vinyl acetate copolymer can be performed by a known method.

In the present invention, a copolymerizable ethylenically unsaturated monomer may be copolymerized as long as the effects of the present invention are not impaired. Examples of such a monomer include propylene and 1-butene. , Olefins such as isobutene, acrylic acid, methacrylic acid, crotonic acid, (anhydrous) phthalic acid,
Unsaturated acids such as (anhydride) maleic acid and (anhydride) itaconic acid or salts thereof, mono- or dialkyl esters having 1 to 18 carbon atoms, acrylamide, 1 to 1 carbon atoms
8, acrylamides such as N-alkylacrylamide, N, N-dimethylacrylamide, 2-acrylamidopropanesulfonic acid or a salt thereof, acrylamidopropyldimethylamine or an acid salt thereof or a quaternary salt thereof, methacrylamide, having 1 to 18 carbon atoms Methacrylamides such as N-alkylmethacrylamide, N, N-dimethylmethacrylamide, 2-methacrylamidopropanesulfonic acid or a salt thereof, methacrylamidopropyldimethylamine or an acid salt thereof or a quaternary salt thereof, N-vinylpyrrolidone N-vinylamides such as, N-vinylformamide and N-vinylacetamide;
Vinyl cyanides such as acrylonitrile and methacrylonitrile, vinyl ethers such as alkyl vinyl ethers having 1 to 18 carbon atoms, hydroxyalkyl vinyl ethers and alkoxyalkyl vinyl ethers, vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride and vinyl bromide And vinylsilanes such as trimethoxyvinylsilane, allyl acetate, allyl chloride, allyl alcohol, dimethylallyl alcohol, trimethyl- (3-acrylamido-3-dimethylpropyl)-
Examples thereof include ammonium chloride and acrylamide-2-methylpropanesulfonic acid. Further, post-modification such as urethanization, acetalization, and cyanoethylation may be performed as long as the gist of the present invention is not impaired. Also, EV
It is also possible to use two or more different types of EVOH as OH (A), in which case the ethylene content is 5 mol%.
By using a blend of EVOH having a difference of at least 1 and / or a degree of saponification of at least 1 mol% and / or an MFR ratio of at least 4, further flexibility and thermoformability can be maintained while maintaining gas barrier properties. This is useful because the film formation stability and the like are improved.

The polyamide resin (B) used in the present invention must have a melting point of 160 ° C. or less, and the effect of the present invention can be obtained even if a polyamide resin having a melting point of more than 160 ° C. is used. And more preferably 80 to 150 ° C, particularly preferably 80 to 140 ° C.

Specific examples of the polyamide resin (B) include polycapramide (nylon 6), poly-ω-aminoheptanoic acid (nylon 7), poly-ω-aminononanoic acid (nylon 9), and polyundecaneamide (nylon). 11), polylauryl lactam (nylon 12), polyethylene diamine adipamide (nylon 26), polytetramethylene adipamide (nylon 46), polyhexamethylene adipamide (nylon 66), polyhexamethylene sebacamide ( Nylon 610), polyhexamethylene dodecamide (nylon 612), polyoctamethylene adipamide (nylon 8, 6), polydecamethylene adipamide (nylon 108), caprolactam / lauryl lactam copolymer (nylon 6/12 ), Caprolactam / ω-aminonona Acid copolymer (nylon 6/9),
Caprolactam / hexamethylene diammonium adipate copolymer (nylon 6/66), lauryl lactam / hexamethylene diammonium adipate copolymer (nylon 12/66), ethylenediamine adipamide / hexamethylene diammonium adipate copolymer (nylon 26/66), caprolactam / hexamethylenediammonium adipate / hexamethylenediammonium sebacate copolymer (nylon 66/61)
0), ethylene ammonium adipate / hexamethylene diammonium adipate / hexamethylene diammonium sebacate copolymer (nylon 6/66/61)
0), polyhexamethylene isophthalamide, polyhexamethylene terephthalamide, hexamethylene isophthalamide / terephthalamide copolymer, or a polyamide resin modified with an aromatic amine such as methylene benzylamine or m-xylene diamine; Among xylylenediammonium adipates, etc., the melting point is 1
Those having a temperature of 60 ° C. or lower can be mentioned.

Here, the melting point is measured by a differential scanning calorimeter (DSC).
Is the melting peak temperature (° C.) measured at a heating rate of 10 ° C./min.

The method for lowering the melting point of the polyamide resin to 160 ° C. or lower is not particularly limited. However, industrially, it is preferable to use a copolymer having a specific ratio among the above polyamide resins. Specific examples of the polymer nylon include nylon 6/12, nylon 6/69, nylon 6/66/610, nylon 6/66/610/12,
Nylon 6/66/610/11 and its aromatic amine modified products are listed, and specific commercial names are "Amilan CM4000" and "Amilan CM80".
00, "Amiran CM6541-X3", "Amiran CM831", "Amiran CM833" (all manufactured by Toray Industries, Inc.), "Elvamide 8061", "Elvamide 8062"
S "," Elvamide 8066 "(all manufactured by DuPont Japan)," Grillon CF6S "," Grillon CF62 "
BS ”,“ Grillon CA6E ”,“ Grillon XE338
1 "(above, manufactured by Ms Japan Co., Ltd.).

The polyamide resin (B) was measured using a differential scanning calorimeter (DSC) (heating rate 10 ° C./mi).
n) The heat of fusion (ΔH) to be performed is preferably 80 J / g or less (more preferably 5 to 70 J / g, particularly 10 to 60 J / g). When the heat of fusion (ΔH) exceeds 80 J / g, However, the low-temperature heat sealability (seal strength, bending resistance) tends to decrease, which is not preferable.

The heat of fusion (ΔH) of the polyamide resin is 8
The method for reducing the concentration to 0 J / g or less is not particularly limited.
Industrially, it can be suitably carried out by controlling the degree of polymerization, the molecular weight, the molecular weight distribution, the content of low molecular weight components, the amount of water, the amount of residual monomers and the like in the polyamide resin.

Further, the melt flow rate (MFR) of the polyamide resin (B) (210 ° C., load 2160 g)
g) is 1 to 100 g / 10 minutes (further 5 to 80 g / 1
0 minutes, especially 10 to 50 g / 10 minutes). When the melt flow rate is out of the range, the effects of the present invention tend not to be sufficiently exhibited, which is not preferable.

The method for controlling the MFR of the polyamide resin within the above range is not particularly limited. However, industrially, the degree of polymerization, molecular weight, molecular weight distribution, low molecular weight component content, water content, residual monomer It can be suitably performed by controlling the amount and the like.

In the present invention, the polyamide resin (B) includes a structure, a composition, a melting point, a heat of fusion, and a molecular weight (MF).
R), two or more kinds of polyamide resins having different molecular weight distributions can be used in combination.

The heat seal material of the present invention contains (A) and (B) as described above, and its content ratio is not particularly limited, but its weight ratio (A / B) is as follows:
50 / 50-99.9 / 0.1 (further 50 / 50-9
9/1, especially 60/40 to 97/3, especially 70/3
0 to 95/5), and the weight ratio is preferably 50/50.
If it is smaller than this, the gas barrier properties may be insufficient. Conversely, if it is larger than 99.9 / 0.1, the low-temperature heat sealability (seal strength, flex resistance) tends to decrease, which is not preferable. .

The heat sealing material of the present invention preferably contains boron or a boron compound (C) in addition to the above (A) and (B).

Examples of the boron compound (C) include boric acid, calcium borate, cobalt borate, zinc borate (zinc tetraborate, zinc metaborate, etc.), aluminum / potassium borate, and ammonium borate (metaborate). Ammonium, ammonium tetraborate, ammonium pentaborate, ammonium octaborate, etc.), cadmium borate (cadmium orthoborate, cadmium tetraborate, etc.), potassium borate (potassium metaborate, potassium tetraborate,
Potassium pentaborate, potassium hexaborate, potassium octaborate, etc., silver borate (silver metaborate, silver tetraborate, etc.), copper borate (cupric borate, copper metaborate, copper tetraborate) Sodium borate (sodium metaborate, sodium diborate, sodium tetraborate, sodium pentaborate, sodium hexaborate, sodium octaborate, etc.),
Lead borate (lead metaborate, lead hexaborate, etc.), nickel borate (nickel orthoborate, nickel diborate, nickel tetraborate, nickel octaborate, etc.), barium borate (barium orthoborate, metaborate) Barium, barium diborate, barium tetraborate, etc.), bismuth borate,
Magnesium borate (magnesium orthoborate, magnesium diborate, magnesium metaborate, trimagnesium tetraborate, pentamagnesium tetraborate, etc.), manganese borate (manganese borate 1, manganese metaborate,
In addition to manganese tetraborate and the like, lithium borate (lithium metaborate, lithium tetraborate, lithium pentaborate and the like), and boric acid such as borax, carnite, inyoite, goethite, sianite, and Zeyberite Salt minerals and the like, preferably borax, boric acid, sodium borate (sodium metaborate, sodium diborate, sodium tetraborate, sodium pentaborate, sodium hexaborate, sodium octaborate, etc.) Is used.

The content of (C) is not particularly limited, but is 10% in terms of boron with respect to the total amount of (A) and (B).
It is preferable that the content is contained so as to be 10000 to 10000 ppm (more preferably 20 to 5000 ppm, particularly 50 to 2000 ppm). When the content is less than 10 ppm, the effect of the addition may not be sufficiently exerted. When the amount is large, the appearance of the heat seal material tends to deteriorate, which is not preferable.

The heat seal material of the present invention is characterized in that the above (A)
And (B) or (A) to (C). The resin composition is not particularly limited to obtain such a resin composition, and (A) and (B) or (A) to (C) ) Components may be blended. In the former case, (A) and (B)
In the blending of the components, both of them may be melt-kneaded. In the latter blending of the components (A) to (C), specifically, after the components (A) to (C) are mixed at once, A method of melt-kneading, a method of melt-kneading the components (A) and (B), a method of adding the component (C) and further melt-kneading, a method of adding the component (C) to the component (A) and the method of (B) A method of melt-kneading the components, a method of melt-kneading the component (A) after adding the component (C) to the component (B), and a method of melting and kneading the components (A) and (B). Later, the two are melt-kneaded, (A) to
A method of uniformly dissolving the component (C) in a solvent capable of dissolving and mixing and then removing the solvent can be mentioned. A preferred method is used, and such a method is described in more detail. However, the present invention is not limited to this.

When the boron or the boron compound (C) is contained in the EVOH (A), the EVOH (A) can be contained by bringing the EVOH (A) into contact with an aqueous solution of the boron or the boron compound (C). The concentration of boron or boron compound (C) in the aqueous solution is 0.001 to 1% by weight (further, 0.005 to 0.8% by weight, particularly 0.01 to 0.5% by weight) in terms of boron. Preferably
If the amount is less than 0.001% by weight, it becomes difficult to contain a predetermined amount of boric acid. Conversely, if the amount exceeds 1% by weight, the appearance of the heat seal material tends to deteriorate, which is not preferable.

The method of bringing EVOH (A) into contact with the aqueous solution is not particularly limited, but usually, the above-mentioned boron or boron compound is charged with the EVOH (A) formed into pellets into the aqueous solution and stirred. It is preferable to contain (C).

In preparing (molding) the EVOH pellets described above, a known method can be employed.
For example, after a mixed solution of EVOH (A) in water and alcohol is extruded into a coagulating liquid into a strand or a sheet, the resulting strand or sheet may be cut into pellets. As the shape of the EVOH (A) in the form of a pellet, a columnar shape, a spherical shape or the like is preferable. In the case of a cylindrical shape, the diameter is preferably 1 to 10 mm and the length is 1 to 10 mm. 10 to 10 mm is preferred. The EVOH (A) has a diameter of 0.1 to 10
Those having a microporous internal structure in which pores of about μm are uniformly distributed are preferable in that they can uniformly contain boron or boron compound (C), and usually EVOH (A)
When extruding a solution (water / alcohol mixed solvent or the like) into a coagulation bath, the concentration of the EVOH (A) solution (20 to 80% by weight), the extrusion temperature (45 to 70 ° C), and the type of solvent (water / alcohol) Mixing weight ratio = 80 / 20-5 / 95
Etc.), the temperature of the coagulation bath (1 to 20 ° C.), the residence time (0.2
5 to 30 hours), the amount of EVOH (A) in the coagulation bath (0.
(2 to 2% by weight), etc., it is possible to obtain EVOH (A) having the structure. Further, those having a water content of 20 to 80% by weight are preferable because the compounds and the like can be uniformly and rapidly contained. In adjusting the content of boron or boron compound (C), although not particularly limited, in the above-mentioned contact treatment with an aqueous solution, the concentration of the aqueous solution of boron or boron compound (C), the contact treatment time, the contact treatment temperature, This can be achieved by controlling the stirring speed during the contact treatment, the water content of the EVOH (A) to be treated, and the like.

Thus, boron or boron compound (C)
Is obtained in the form of pellets, and usually, the composition is obtained through a drying step after the above-mentioned contact treatment.

As such a drying method, various drying methods can be adopted. For example, fluid drying is performed while the composition in the form of pellets or the like is stirred or dispersed by mechanical or hot air, and the composition in the form of pellets or the like is given a dynamic action such as stirring or dispersion. Drying is carried out without drying. Examples of the dryer for performing fluidized drying include a cylindrical / groove type stirring dryer, a cylindrical dryer, a rotary dryer, a fluidized bed dryer, a vibration fluidized bed dryer, and a cone. Rotary dryers and the like, and as a dryer for performing stationary drying, a batch type box dryer as a material stationary type,
Examples of the material transfer type include, but are not limited to, a band dryer, a tunnel dryer, and a vertical dryer. It is also possible to combine fluidized drying and standing drying.

Air or an inert gas (nitrogen gas, helium gas, argon gas, etc.) is used as a heating gas used in the drying process. The temperature of the heating gas is 40 to 150 ° C. It is preferable from the viewpoint of preventing thermal deterioration of the composition. The time for the drying treatment depends on the water content of the composition and the amount of the treatment, but usually about 15 minutes to 72 hours is preferable in terms of productivity and prevention of thermal deterioration of the composition.

The composition is dried under the above conditions,
An EVOH composition comprising VOH (A) and boron or a boron compound (C) is obtained. The moisture content of the composition after the drying treatment is 0.001 to 5% by weight (further, 0.01 to 5% by weight). 2% by weight, especially 0.1 to 1 part by weight), and the water content is 0.001% by weight.
If less, the appearance of the heat seal material tends to decrease,
Conversely, if it exceeds 5% by weight, the polyamide resin (B) described later
This is not preferred because foaming is apt to occur during melt-kneading with.

Next, the polyamide resin (B) is further melted in the EVOH composition [pellet (A) containing (C)] obtained from the EVOH (A) and boron or the boron compound (C). Kneading is not particularly limited in the melt kneading, as long as the composition and the polyamide resin (B) are sufficiently melt kneaded.
A known method can be adopted. For example, a known kneading device such as a kneader ruder, an extruder, a mixing roll, a Banbury mixer, a plastomill, or the like can be used, and usually 150 to 300 ° C. (furthermore, 180 to 280 ° C.).
C.) for about 1 minute to 1 hour, and it is advantageous to use an extruder such as a single screw extruder or a twin screw extruder industrially, and if necessary, vent suction. It is also preferable to provide a device, a gear pump device, a screen device, and the like. In particular, in order to remove moisture and by-products (such as pyrolyzed low-molecular-weight products), the extruder is provided with one or more vent holes to suck under reduced pressure or to prevent oxygen from being mixed into the extruder. By continuously supplying an inert gas such as nitrogen into the hopper, it is possible to obtain a high-quality resin composition in which thermal coloring and thermal deterioration are reduced. In the melt kneading, 1) a method in which the solid EVOH composition and the polyamide resin (B) are mixed and melt kneaded together, and 2) a solid polyamide resin (B) is added to the molten EVOH composition. ) And melt-kneading; 3) a method in which a solid EVOH composition is charged into a molten polyamide resin (B) and melt-kneading; 4) a molten EVOH composition and a polyamide resin (B). B) may be mixed and melt-kneaded.

Thus, the resin compositions (A) and (B) or (A) to (C) used in the heat sealing material of the present invention can be obtained. Acids such as acids and their alkali metals, alkaline earth metals, and metal salts such as transition metals can also be contained, so that the thermal stability of the resin composition, long-run moldability, and the interlayer between the adhesive resin when the laminate is formed. It is preferable in that the adhesiveness and the like are improved, and particularly, an alkali metal salt and an alkaline earth metal salt are preferably used in that they have excellent effects.

Examples of such metal salts include acetic acid, propionic acid, butyric acid, lauric acid, stearic acid, oleic acid, such as sodium, potassium, calcium, and magnesium.
Metal salts of organic acids such as behenic acid and the like, and inorganic acids such as sulfuric acid, sulfurous acid, carbonic acid, phosphoric acid and the like can be mentioned, and preferred are acetate, phosphate and hydrogen phosphate. The content of the metal salt is 5 to 1000 p in terms of metal with respect to the resin composition.
pm (further 10 to 500 ppm, especially 20 to 300 ppm
ppm), and the content is 5 pp
If less than m, the content effect may not be sufficiently obtained,
Conversely, if it exceeds 1000 ppm, it tends to cause coloring of the resin composition used for the heat sealing material, which is not preferable.
When two or more kinds of alkali metal and / or alkaline earth metal salts are contained in the resin composition, the total amount is preferably in the above range.

The method for incorporating acids or metal salts thereof into the resin composition is not particularly limited.
(A) or contained in the EVOH composition,
H (A) or the EVOH composition and the polyamide resin (B) at the same time when they are blended.
(A) Or EVOH composition and polyamide resin (B)
Can be contained in the resin composition after blending, or these methods can be combined. In order to obtain the effect of the present invention more remarkably, EVOH (A) or EVO
The method of allowing the H composition to be contained is preferable in terms of excellent dispersibility of acids and metal salts thereof.

The method of preliminarily containing EVOH (A) is as follows: a) EVOH having a water content of 20 to 80% by weight.
A method in which the porous precipitate of (A) is brought into contact with an aqueous solution of an acid or a metal salt thereof to contain the acid or a metal salt thereof, and then dried, and a) a uniform EVOH solution (water / alcohol solution or the like). After containing acids and their metal salts, extruding them into a coagulating solution in the form of a strand, and then cutting the resulting strand into pellets for further drying treatment, c)
A method in which EVOH (A) and acids and their metal salts are mixed at once and then melt-kneaded by an extruder or the like; d) EVOH (A)
In the production of, the alkali (sodium hydroxide, potassium hydroxide, etc.) used in the saponification step is neutralized with an acid, such as acetic acid, and the remaining acids, such as acetic acid, and by-produced sodium acetate, potassium acetate, etc. A method of adjusting the amount of the alkali metal salt by a water washing treatment, and the like can be given.
In order to obtain the effect of the present invention more remarkably, the method a), a) or d), which is excellent in dispersibility of acids and metal salts thereof, is preferable. In addition, in order to be contained in the EVOH composition,
What is necessary is just to make it contain simultaneously with (C) in EVOH (A).

In the present invention, a saturated aliphatic amide (eg, stearic acid amide), an unsaturated fatty acid amide (eg, oleic acid amide, etc.), Fatty acid amides (e.g., ethylene bisstearic acid amide, etc.), fatty acid metal salts (e.g., calcium stearate, magnesium stearate, zinc stearate, etc.), low molecular weight polyolefins (e.g., low molecular weight polyethylene having a molecular weight of about 500 to 10,000, or low molecular weight Lubricants such as polypropylene), inorganic salts (e.g., hydrotalcite), plasticizers (e.g., aliphatic polyhydric alcohols such as ethylene glycol, glycerin, and hexanediol), oxygen absorbers (e.g., as an inorganic oxygen absorber, Reduced iron powders, as well as water-absorbing substances and electricity And the like, aluminum powder, potassium sulfite, titanium oxide photocatalyst, etc., as organic compound-based oxygen absorbers, ascorbic acid, furthermore, fatty acid esters and metal salts thereof, hydroquinone, gallic acid, hydroxyl-containing phenol aldehyde resin, etc. Of a transition metal with a nitrogen-containing compound such as polyhydric phenols, bis-salicylaldehyde-imine cobalt, tetraethylene pentamine cobalt, cobalt-Schiff base complex, porphyrins, macrocyclic polyamine complex, and polyethylene imine-cobalt complex. Coordination body, terpene compound, reactant of amino acids and hydroxyl group-containing reducing substance, triphenylmethyl compound, etc., as a high molecular oxygen absorber,
Coordination conjugate of nitrogen-containing resin and transition metal (eg, combination of MXD nylon and cobalt), blend of tertiary hydrogen-containing resin and transition metal (eg, combination of polypropylene and cobalt), carbon-carbon unsaturated A blend of a bond-containing resin and a transition metal (eg, a combination of polybutadiene and cobalt), a photo-oxidatively degradable resin (eg, a polyketone), an anthraquinone polymer (eg, polyvinyl anthraquinone),
Further, a photoinitiator (such as benzophenone), a peroxide supplement (such as a commercially available antioxidant) or a deodorant (such as activated carbon) is added to these compounds, etc.), a heat stabilizer, a light stabilizer, Antioxidants, ultraviolet absorbers, coloring agents, antistatic agents, surfactants, antibacterial agents, antiblocking agents (such as talc fine particles), slip agents (such as amorphous silica), fillers (such as inorganic fillers) Alternatively, other resins (for example, polyolefin, polyester, etc.) may be blended.

The heat-sealing material of the present invention comprises the above-mentioned (A)
And a resin composition containing (B) or (A) to (C) in the form of a film and used for an inner layer or a heat-sealed portion of a packaging material.
In order to obtain the film, a known method can be employed.

For example, a film can be produced by a blown film molding machine, a T-die cast film molding machine, an extrusion coating molding machine, a solution coating molding machine, or the like. Often used as

In producing the laminate, the resin composition may be disposed such that the surface of the resin composition is heat-sealed, and usually disposed on the innermost layer of the laminate.
That is, another substrate (a thermoplastic resin or the like) is laminated on one surface of the HS film. As a lamination method, for example, a method of melt-extruding and laminating another substrate on the HS film, or a method of laminating another substrate A method of melt-extruding and laminating the resin composition (a resin composition used for an HS film) on a material, a method of co-extruding the resin composition with another base material, and a method of forming an HS film and another base material (layer). A dry lamination method using a known adhesive such as an organic titanium compound, an isocyanate compound, a polyester-based compound, or a polyurethane compound may, for example, be mentioned. The melt molding temperature during the above-mentioned melt extrusion is often selected from the range of 150 to 300 ° C.

As such another substrate, a thermoplastic resin is useful, and specifically, linear low-density polyethylene, low-density polyethylene, ultra-low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-acetic acid Vinyl copolymer, ionomer, ethylene-propylene (block or random) copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic acid ester copolymer Polymer, polypropylene, propylene-α-olefin (α-olefin having 4 to 20 carbon atoms) copolymer, homo- or copolymer of olefin such as polybutene, polypentene, polymethylpentene, or homo- or copolymer of these olefins Graft modification of polymer with unsaturated carboxylic acid or its ester Polyolefin resins, polyester resins, polyamide resins (including copolymerized polyamides), polyvinyl chloride, polyvinylidene chloride, acrylic resins, polystyrene resins, etc.
Vinyl ester resins, polyester elastomers, polyurethane elastomers, chlorinated polyethylenes, chlorinated polypropylenes, aromatic or aliphatic polyketones, and polyalcohols obtained by reducing these, and E
VOH and the like, but from the viewpoint of practicality such as characteristics (particularly strength and appearance) of the laminate, polypropylene, ethylene-
Propylene (block or random) copolymer, polyamide, polyethylene, ethylene-vinyl acetate copolymer,
Polystyrene, polyethylene terephthalate (PE
T) and polyethylene naphthalate (PEN) are preferably used, and polyolefin resins, polyester resins and polyamide resins are particularly preferable.

Further, when the HS film is extrusion-coated with another base material, or when a film or sheet of another base material is laminated with an adhesive, the base material is not limited to the above-mentioned thermoplastic resin. Any substrate (paper, metal foil, uniaxially or biaxially stretched plastic film or sheet and its inorganic deposit, woven fabric, nonwoven fabric, cotton-like, woody, etc.) can be used.

The layer structure of the laminate is such that the HS film layer is a
(A₁, A_Two, ...), other substrates such as thermoplastics
Layer b (b₁, B_Two, ...), two layers of a / b
A / b / a, a₁/ A_Two/ B, a / b₁
/ B_Two, A / b_Two/ B₁/ A / b₁/ B_Two, B_Two/ B₁/ A /
b₁/ A, a₁/ B₁/ A_Two/ B_TwoAny combination is possible
And furthermore, at least the thermoplastic resin and the thermoplastic resin
Let R be the regrind layer made of a mixture of conductive resins
B / R / a, b / R / b / a, b_Two/ B₁/ R / a ₁
/ A_Two, B / R / a / R / a / R / a, etc.
Noh.

In the above-mentioned layer structure, an adhesive resin layer can be provided between the respective layers as required, and various adhesive resins can be used. It is preferable in that a laminate excellent in the above properties can be obtained. Although it depends on the type of the resin b and cannot be said unconditionally, an unsaturated carboxylic acid or an anhydride thereof is added to an olefin polymer (the above-mentioned olefin alone or copolymer). Examples thereof include a modified olefin polymer containing a carboxyl group obtained by chemically bonding by a reaction or a graft reaction, and specifically, maleic anhydride graft-modified polyethylene, maleic anhydride graft-modified polypropylene, Maleic anhydride graft-modified ethylene-propylene (block or random) copolymer, maleic anhydride graft-modified Len - ethyl acrylate copolymer, maleic anhydride graft-modified ethylene anhydride - one or a mixture of two or more species selected from vinyl acetate copolymers and the like as preferred. At this time, the amount of the unsaturated carboxylic acid or the anhydride thereof contained in the thermoplastic resin is preferably 0.001 to 3% by weight, more preferably 0.01 to 1% by weight, and particularly preferably 0.03% by weight. ~ 0.5
% By weight. If the amount of modification in the modified product is small, the adhesiveness may be insufficient, and if it is too large, a crosslinking reaction may occur and moldability may deteriorate, which is not preferable. These adhesive resins can also be blended with the resin composition, a rubber / elastomer component such as EVOH, polyisobutylene, ethylene-propylene rubber, and the like, and the resin of layer b. In particular, by blending a polyolefin resin different from the base polyolefin resin of the adhesive resin, the adhesiveness may be improved, which is useful.

The thickness of each layer of the laminate cannot be determined unconditionally depending on the layer constitution, the type of b, the use and the form of the container, the required physical properties, and the like.
-100 μm, especially 5-30 μm), and the b layer is 2-40
0 μm (further 6 to 200 μm, especially 10 to 80 μm
m), the adhesive resin layer has a thickness of 1 to 200 μm (further 3 to 10 μm).
0 μm, especially 5 to 20 μm). If the thickness of the a layer is less than 1 μm, the gas barrier properties and the heat sealing properties are insufficient, and the thickness control becomes unstable.
When the thickness is more than 00 μm, the impact resistance is inferior and is not economical and unfavorable. When the thickness of the b layer is less than 2 μm, the rigidity is insufficient. On the other hand, when the thickness exceeds 400 μm, the weight becomes large, and it is not economical and unfavorable. If the conductive resin layer is less than 1 μm, the interlayer adhesion becomes insufficient and the thickness control becomes unstable. On the other hand, if it exceeds 200 μm, the weight increases and it is not economical and is not preferred.

The laminate is used as it is for various heat sealing applications, but it is also preferable to perform a heat stretching treatment for the purpose of further improving the physical properties of the laminate. Here, the heat-stretching treatment is to stretch a thermally heated laminate, and the stretching may be either uniaxial stretching or biaxial stretching, and the stretching is performed as high as possible. Thus, an excellent stretched laminate having better physical properties and free from pinholes, cracks, stretching unevenness, uneven thickness, and delamination during stretching can be obtained.

As a stretching method, a roll stretching method, a tenter stretching method, a tubular stretching method, a stretch blow method, a vacuum forming, a pressure forming, a vacuum forming method, or the like having a high draw ratio can be employed. In the case of biaxial stretching, simultaneous biaxial stretching method,
Any of the sequential biaxial stretching methods can be adopted. The stretching temperature is selected from the range of 60 to 170 ° C, preferably about 80 to 160 ° C.

After completion of the stretching, it is also preferable to carry out heat setting. Heat setting can be carried out by known means,
80-170 while keeping the stretched film under tension.
C., preferably at 100 to 160.degree. C. for about 2 to 600 seconds. Further, when used for heat shrink packaging of raw meat, processed meat, cheese, etc., the product film is not heat-set after stretching, and the raw meat, processed meat, cheese, etc. are stored in the film, 50-130 ° C, preferably 7
At 0 to 120 ° C., heat treatment is performed for about 2 to 300 seconds,
The film is heat-shrinked and tightly packaged.

The obtained laminate may be subjected to heat treatment, cooling treatment, rolling treatment, printing treatment, dry laminating treatment, solution or melt coating treatment, bag making, deep drawing, box processing, tube processing, splitting as required. Processing and the like can be performed.

As the heat sealing device, a normal device such as a hot plate type or an impulse type can be adopted, but a hot plate type is preferable from the viewpoint of accuracy of temperature control and shortening of the heat sealing time. The heat sealing time (hot plate contact time) is
0.1 ~ 5 seconds, pressure is 0.1 ~ 5kg / cm ² ,
The temperature is between 100 and 170C. In order to obtain a packaging bag, a normal bag making machine can be employed, for example, a hot sealing type or hot roll type bag making machine can be used, and a side seal type, a three-side seal type, a gas seal type. Processed into bags for use. In addition, an automatic bag making and filling machine such as a pillow package, a three-side seal package, a four-side seal package, or the like that simultaneously performs bag making and filling of contents can be used.

Thus, a laminate provided with the heat sealing material of the present invention can be obtained.
It is useful as a packaging material for various packaging applications (food, beverages, cosmetics, pharmaceuticals, industrial chemicals, agricultural chemicals, solvents, fuels, etc.), especially polyolefin resins, polyester resins,
It is very useful as a laminate with a polyamide resin.

[0052]

The present invention will be specifically described below with reference to examples. In the examples, “parts” and “%” are based on weight unless otherwise specified.

For the measurement of the melting point of the polyamide resin, a differential scanning calorimeter (“DSC-
7 ") at a heating rate of 10 ° C./min. The boric acid content in EVOH was measured by melting EVOH with alkali and quantifying boron by ICP emission spectroscopy. Further, the measurement of the alkali metal content was carried out by dissolving the EVOH in an aqueous solution of hydrochloric acid after incineration and quantifying the alkali metal by atomic absorption spectrometry.

Example 1 EVOH containing 0.2% boric acid (C) [ethylene content 32 mol%, degree of saponification 99.5 mol%, MFR 3 g
/ 10 min (210 ° C., load 2160 g), containing 400 ppm of sodium acetate] (A) 85 parts and polyamide resin [Grillon CF6S manufactured by EMS Japan Co., copolymer of nylon 6/12, density 1.05 g / cm ³ , melting point 133 ° C., ΔH 51 J / g, MFR 18 g / 10 min (2
10 ° C., load 2160 g)] (B) 15 parts by melt kneading with a twin-screw extruder under the following conditions to obtain a resin composition [boron 3
00 ppm, sodium 95 ppm].

Next, the resin composition obtained above was supplied to a single screw extruder, and a film was formed under the following conditions to a thickness of 15 mm.
After obtaining an HS film having a thickness of 15 μm, a commercially available biaxially stretched nylon film (thickness: 15 μm) was obtained by using a polyurethane adhesive (“Adcoat” manufactured by Toyo Morton Co., Ltd.) at 0.5 g / cm ^2. ) To produce a laminate.

(Bending Heat Sealing Resistance) The obtained laminate was cut into 22 cm long × 16 cm wide (two pieces), with the HS film layer on the inside, at 145 ° C., 2 kg / cm ² , and 0.1 mm.
Under the condition of 5 seconds, the end in the longitudinal direction was heat-sealed (seal width 5 mm) with a heat sealer to form a cylinder. Using this cylindrical film, a bending resistance test was performed 50 times. The bending resistance test was performed by using a gelbo flex tester (manufactured by Taihei Rika Kogyo Co., Ltd.), gripping both ends of the cylindrical film, holding an initial gripping interval of 7 in, and a gripping interval of 1i at the maximum bending.
n, a twist of an angle of 440 ° is applied at the first 3.5 in of the stroke, and the subsequent 2.5 in is a reciprocating motion of linear horizontal movement at a speed of 40 times / min at 23 ° C.
The test was performed under the condition of 50% RH. After the bending resistance test, both ends of the cylindrical film were heat-sealed under the same conditions as above to obtain a bag, and the oxygen permeability (cc / day · air) of the bag was measured using an oxygen permeability measuring device (“OXTRAN10” manufactured by MOCON).
/ 50 ”) at 23 ° C. and 50% RH.

(Fragrance retention) One end of the cylindrical film obtained above after the bending resistance test was placed at 145 ° C., 2 kg / cm ² ,
100 cc of water to which a few drops of vanilla essence was added was placed in a packaging bag prepared by heat sealing (sealing width 5 mm) under the condition of 0.5 seconds, and the opening was similarly heat-sealed and sealed. Prepared, put in a 2 liter glass container, sealed, stored at 23 ° C., and evaluated the fragrance retention performance over time (leakage of scent and change of scent) as follows. [Leakage] ・ ・ ・: Even after one month from the start of the test, no fragrance of vanilla essence was detected in the glass container. ×: One week after the start of the test, the fragrance of vanilla essence was leaking into the glass container. [Change] ○: One month after the start of the test, the bag was opened and the fragrance of vanilla essence was confirmed, but there was no change. ×: One week after the start of the test, the fragrance of vanilla essence in the bag had changed.

Example 2 EVOH containing 0.13% of boric acid (C) [ethylene content 29 mol%, saponification degree 99.6 mol%, MFR 1
5 g / 10 min (210 ° C., load 2160 g), containing 400 ppm of sodium acetate, containing 90 ppm of potassium acetate] (A) 85 parts and a polyamide resin [“Grillon CF6S” manufactured by EMS Japan Co., a copolymer of nylon 6/12, Density 1.05 g / cm ³ , melting point 133 ° C, ΔH5
1 J / g, MFR 18 g / 10 min (210 ° C., load 21
60 g)] (B) 15 parts by melt kneading with a twin-screw extruder under the following conditions to obtain a resin composition [containing 190 ppm of boron,
95 ppm of sodium and 30 ppm of potassium] were obtained, and the following procedure was carried out in the same manner as in Example 1 to obtain a laminate, which was similarly evaluated.

Example 3 EVOH containing 0.13% of boric acid (C) [ethylene content 38 mol%, degree of saponification 99.6 mol%, MFR 3
g / 10 min (210 ° C., load 2160 g), containing 336 ppm of sodium acetate, sodium dihydrogen phosphate 92p
pm, 230 ppm calcium acetate] (A) 8
5 parts and polyamide resin ["Grillon CF6S" manufactured by EMS Japan Co., nylon 6/12 copolymer, density 1.05 g / cm ³ , melting point 133 ° C, ΔH51J / g,
MFR 18 g / 10 min (210 ° C., load 2160 g)]
(B) 15 parts were melt-kneaded with a twin-screw extruder under the following conditions to obtain a resin composition [containing 190 ppm of boron, 95 ppm of sodium, and 80 ppm of calcium],
The following steps were performed in the same manner as in Example 1 to obtain a laminate, and the evaluation was performed in the same manner.

Example 4 As component (B), "Amilan CM8000" manufactured by Toray Industries, Inc.
[Nylon 6/66/610/12 copolymer, density 1.12 g / cm ³ , melting point 131 ° C., ΔH 40 J / g,
MFR 25 g / 10 min (210 ° C., load 2160 g)]
A resin composition was obtained in the same manner as in Example 1 except for using. Next, using the obtained resin composition, the outer layer was the layer (I) of the resin composition, the other outer layer was MFR 2.5 g / 10 min, and the density was 0.89 g / cm ³ ,
Layers (II), (I) and (II) of ethylene-1-butene random copolymer (LLDPE) having an ethylene content of 90 mol%
LLD with MFR of 3.0 g / 10 min (190 ° C., load 2160 g) and maleic anhydride content of 0.1%
(I) comprising an adhesive resin layer (III) made of PE /
A laminate of (III) / (II) = 20/5/20 μm was obtained and evaluated in the same manner as in Example 1.

Example 5 In Example 4, "Grillon CA6E" [nylon 6/12 copolymer, density 1.06 g / cm ³ , melting point 124 ° C., ΔH 39
J / g, MFR 26g / 10 min (210 ° C, load 216
0g)], and evaluated similarly.

Example 6 In Example 4, "Amilan CM6541-X3" (a copolymer of nylon 6/12, density 1.11 g / cm ³ , melting point 135 ° C., ΔH 40
J / g, MFR 12 g / 10 min (210 ° C., load 216
0g)], and evaluated similarly.

Example 7 The procedure of Example 1 was repeated except that the component (C) was not used, and the same evaluation was conducted.

Example 8 The procedure of Example 1 was repeated except that the contents of the components (A) and (B) were changed to 90 parts and 10 parts, respectively. The boron content in the resin composition was 315 ppm, and the sodium content was 100 ppm.
Met.

Example 9 The procedure of Example 1 was repeated except that the contents of the components (A) and (B) were changed to 70 parts and 30 parts, respectively. In addition, the boron content in the resin composition was 245 ppm, and the sodium content was 80 ppm.

Comparative Example 1 The procedure of Example 1 was repeated, except that the component (B) was not contained in the resin composition, and the same evaluation was performed.

Comparative Example 2 In Example 1, "Amilan CM6541-X4" (a copolymer of nylon 6/12, density 1.10 g / cm ³ , melting point 196 ° C.) manufactured by Toray Industries, Inc. instead of the component (B) Was carried out in the same manner as above, and similarly evaluated.

Table 1 summarizes the evaluation results of the examples and comparative examples.

[Table 1] Bending heat sealability, scent retention seal strength * Oxygen permeability ** Leakage Change Example 1 0.9 0.014 ○ 〃 20.8 0.010 ○ ３ 31 1 0.018 ○ 〃 41.0 0.010 ○ ５ 5 1.1 0.013 ○ 〃 60.9 0.010 ○ 〃 70.6 0.014 ○ 〃 80. 7 0.013 ○ ○ ９ 9 1.1 0.017 ○ ○ Comparative Example 1 Less than 0.1> 1.0 × ○ 未 満 2 Less than 0.1> 1.0 × ○ * The unit of the seal strength is kg / kg. 15mm ** The unit of oxygen permeability is cc / day ・ air

[0070]

Since the heat seal material of the present invention contains EVOH and a polyamide resin having a melting point of 160 ° C. or less, it has excellent heat sealability (seal strength and bending resistance) at low temperatures, and furthermore, Excellent oxygen barrier and fragrance retention,
It is useful as a packaging material for various packaging applications (food, beverages, cosmetics, pharmaceuticals, industrial chemicals, agricultural chemicals, solvents, fuels, etc.), especially polyolefin resins, polyester resins,
It is very useful as a laminate with a polyamide resin.

Claims (3)

[Claims] 1. A heat sealing material comprising a saponified ethylene-vinyl acetate copolymer (A) and a polyamide resin having a melting point of 160 ° C. or less. 2. The weight ratio (A / B) of the saponified ethylene-vinyl acetate copolymer (A) and the polyamide resin having a melting point of 160 ° C. or less is 50/50 to 99.9 / 0.1. The heat seal material according to claim 1, wherein: 3. Boron or boron compound (C)
The heat sealing material according to claim 1, wherein the heat sealing material comprises: