JPH07251474A - Olefinic resin molding having gas barrier properties - Google Patents

Abstract

PURPOSE:To provide an olefinic resin molding excellent in gas barrier properties. CONSTITUTION:A silane group-containing olefinic resin is obtained by copolymerizing an ethylenic unsaturated silane compd. having a hydrolyzable org. group represented by general formula RSiR'nY3-n (I) (wherein R is an ethylenic unsaturated hydrocarbon group or a hydrocarbonoxy group, R' is an aliphatic saturated hydrocarbon group, Y is a hydrolyzable org. group and n is 0, 1 or 2) and polyolefin or ethylene. An olefinic resin molding having gas barrier properties is obtained by forming an inorg. oxide membrane on the surface of a molding of the silane group-containing olefinic resin with a unit concn. of a silane compd. of 0.01-10wt.%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an olefin resin molded article suitable for a packaging material having excellent gas barrier properties used for protecting foods, electronic parts and the like from oxygen.

[0002]

2. Description of the Related Art It has been proposed to wrap foods, electronic parts, etc. in a film or a container to prevent the permeation of oxygen to prevent the contents from being oxidized and to maintain the quality for a long time.
For example, in Japanese Patent Publication No. 53-12953, the thickness is 5
On at least one side of a flexible plastic film of polyethylene terephthalate, cellophane, polyamide, polypropylene, polyethylene or the like having a thickness of up to 300 μm, the general formula Si _x O _y (x is 1 or 2, y is 0, 1,
It is an integer of 2 or 3. A transparent plastic film having a high degree of air permeation resistance and moisture permeation resistance, which is obtained by vapor-depositing a silicon oxide having the composition (1) to form a transparent thin film layer having a thickness of 100 to 3000 angstroms.

Further, in Japanese Patent Laid-Open No. 63-237940, a metal oxide selected from the group consisting of In, Sn, Zn, Zr and Ti is provided on at least one surface of the flexible plastic film. A transparent gas barrier film formed by sputtering and further coated with a transparent heat-sealable resin film is disclosed.

When the film material is a resin having a polar group such as polyethylene terephthalate, polyamide and cellophane, the adhesion between these films and the inorganic oxide film is sufficient and the gas barrier property is also good. However, even if a vapor-deposited thin film made of the above-mentioned inorganic oxide is formed on the surface of a polyolefin molded product having no polar group such as polypropylene or polyethylene, the adhesion between the polyolefin molded product and the vapor-deposited thin film is weak. . Therefore, in order to impart a heat-sealing property to this vapor-deposited product, when a heat-sealing resin having a melting point lower than the melting point of the polyolefin constituting the molded article is melt-laminated, or this laminate is used to form a bag or a lid. When performing the secondary processing of the seal,
Or use these bags or fill the contents in the container,
Further, external sterilization or heat is applied to the molded product during retort sterilization, and the vapor-deposited thin film of the inorganic oxide is peeled off from the polyolefin molded product, and the gas barrier property of the molded product deteriorates, which is not practical.

[0005]

SUMMARY OF THE INVENTION The present invention provides a polyolefin resin molded product having an inorganic oxide thin film vapor-deposited thereon. It is an object of the present invention to provide a resin molded product that does not peel off and does not deteriorate in gas barrier property.

[0006]

The present invention has the general formula (I)

[0007]

Embedded image RSiR ′ _n Y _3-n (I) (wherein R is an ethylenically unsaturated hydrocarbon group or a hydrocarbonoxy group, R ′ is an aliphatic saturated hydrocarbon group, and Y is hydrolyzable). Represents an organic group,
n represents 0, 1 or 2. )

A silane group-containing olefin resin obtained by copolymerizing a polyolefin with an ethylenically unsaturated silane compound having a hydrolyzable organic group, or a silane obtained by copolymerizing the silane compound with ethylene. A group-containing olefin resin, wherein an inorganic oxide thin film is formed on the surface of a molded product of a silane group-containing olefin resin in which the unit concentration of the silane compound in the resin is 0.01 to 10% by weight. And an olefin resin molded article having a gas barrier property.

[0009]

In the present invention, a hydrolyzable organic group such as an alkoxysilane group, which is contained in the silane group-containing olefin resin of the molded article substrate, reacts with or is ionically bonded to the deposited film of the inorganic oxide. Therefore, the adhesion between them is extremely high.

[0010]

DETAILED DESCRIPTION OF THE INVENTION Silane Group-Containing Olefin Resin A silane group-containing olefin resin obtained by copolymerizing an ethylenically unsaturated silane is a silane compound having a water-decomposable organic group as a side chain or main chain. An olefin resin having a chain.

For example, as disclosed in JP-B-48-1711 and JP-B-2-31727,
It is obtained by graft-copolymerizing an ethylenically unsaturated silane compound represented by the above formula (1) with a polyolefin in the presence of a radical generator.

As the polyolefin, propylene homopolymer, ethylene homopolymer or ethylene as a main component and a small proportion (generally 0.1 to 15% by weight, preferably 0.5 to 6% by weight) of propylene, Butene-1,
Ethylene resins such as ethylene copolymers which are copolymers with α-olefins such as hexene-1 and octene-1;
Specifically, the density is 0.862 to 0.965 g / cm ^3.
With a melt index of 0.1 to 60 g / 10 minutes, preferably 0.2 to 25 g / 10 minutes, ultra low density polyethylene, low density polyethylene resin, linear linear polyethylene,
Ethylene resins such as medium and low density polyethylene and high density polyethylene resin, ethylene / vinyl acetate copolymer having vinyl acetate content of 0.1 to 35% by weight, preferably 0.2 to 20% by weight, acrylic acid content Is 0.1 to 25% by weight, preferably 0.2 to 20% by weight, ethylene / acrylic acid copolymer, propylene / ethylene (0.5 to 10% by weight) copolymer, propylene / butene-1 copolymer , Propylene / ethylene / butene-1 copolymer, propylene /
Propylene resins such as hexene-1 copolymer and propylene / 4-methylpentene-1 copolymer, polybutene, poly-3-methylbutene-1, poly-4-methylpentene-1, ethylene / propylene copolymer rubber , Ethylene / propylene / diene terpolymers. The ethylenically unsaturated silane compound has the general formula

[0013]

Embedded image RSiR ′ _n Y _3-n (I) (wherein R is an ethylenically unsaturated hydrocarbon group or a hydrocarbonoxy group, R ′ is an aliphatic saturated hydrocarbon group, and Y is hydrolyzable). Represents an organic group,
n represents 0, 1 or 2. )

A silane compound represented by: Specifically, R is vinyl, allyl, isopropenyl, butenyl,
Cyclohexenyl, γ-acryloxypropyl, γ-methacryloxypropyl; R'is methyl, ethyl, propyl, decyl, phenyl; Y is methoxy, ethoxy, formyloxy, acetoxy, propionyloxy, alkyl or arylamino. Is. Particularly preferably, a compound represented by CH ₂ ═CHSi (OA) ₃ (where A is a hydrocarbon group having 1 to 8 carbon atoms), specifically vinyltrimethoxysilane and vinyltri Ethoxysilane, vinyltriacetoxysilane, and γ-methacryloxypropyltrimethoxysilane.

As the radical generator, a compound capable of generating a free radical site in the polyolefin under graft reaction conditions can be used.
All the compounds described in the above-mentioned Japanese Patent Publication No. 48-1711 are applicable. Typical radical generators include organic peroxides such as dicumyl peroxide, t-butyl peroxyoctate and benzoyl peroxide, and azo compounds such as azoisobutyronitrile and methylazoisobutyrate. To be

The amount of the ethylenically unsaturated silane compound used is 0.01 to 15 parts by weight, preferably 0.1 to 10 parts by weight, based on 100 parts by weight of the polyolefin. The amount used is 0.01-5
Parts by weight, preferably 0.01 to 2 parts by weight.

In the production of the silane-grafted modified olefin resin, it is preferable that an antioxidant is present in the reaction system during the graft reaction in order to suppress deterioration due to molecular cleavage of the polyolefin. As the antioxidant, those generally used as antioxidants for polyolefins can be used. For example, 2,6-di-t
-Butyl-4-methylphenol, 2,2'-methylene-bis (4-methyl-6-t-butylphenol),
4,4-butylden-bis- (3-methyl-6-t-butylphenol), octadecyl-3- (3,5-di-
t-butyl-4-hydroxyphenyl) propionate, tetrakis- [methylene-3- (3,5-di-t-
Butyl-4-hydroxyphenyl) propionate] methane, 6- (3,5-di-t-butyl-4-hydroxyanilino) -2,4-bis-octenylthio-1,3
5-triazine, tris- (3,5-di-t-butyl-
Radical chain inhibitors such as 4-hydroxybenzyl) isocyanurate, peroxide decomposers such as dilauryl thiopropionate, distearyl thiodipropionate, distearyl thiodipropionate and trisnonylphenyl phosphite. To be

The amount of the antioxidant used is 0.005 to 10 parts by weight based on 100 parts by weight of the polyolefin.
The amount is preferably 0.01 to 5 parts by weight, and is 0.05 to 5 as a ratio of the amount of the radical generator used.
It is preferably 0, particularly 0.05 to 5.

The graft reaction of the ethylenically unsaturated silane compound onto the polyolefin is carried out by adding 0.1 to 10 parts by weight of the ethylenically unsaturated silane compound to the polyolefin and 0.01 to 2.0 parts by weight of the radical generator. Parts and about 0 to 5 parts by weight of the above-mentioned antioxidant, and using, for example, an extruder, Banbury mixer, Plabender, etc., to melt and knead at a temperature above the decomposition temperature of the radical generator to react. Can be carried out.

Further, as described in US Pat. No. 3,225,018, 0.01 to 10% by weight of the ethylenically unsaturated silane compound and 99.99 to 9% of ethylene.
It is obtained by radical copolymerization with 0% by weight under ordinary high-pressure polymerization conditions. In this case, vinyl monomers other than ethylene, such as vinyl acetate, vinyl propionate, and other vinyl esters, ethyl acrylate, butyl acrylate, methyl methacrylate, and other unsaturated fatty acid esters, acrylic acid, methacrylic acid, and other unsaturated monomers. Saturated fatty acids or metal salts thereof, α-olefins such as propylene and butene-1,4-methylpentene-1 may be further copolymerized within the range of up to 35% by weight.

These silane group-containing olefin resins are
The unit concentration based on the silane compound is 0.01 to 10% by weight, particularly preferably 0.5 to 5% by weight.
Also, the silane group-containing olefin resin can promote the adhesion effect by exposing it to a water atmosphere in the presence of a silanol condensation catalyst.

Examples of silanol condensation catalysts include dibutyltin dilaurate, dibutyltin diacetate and dibutyltin dioctoate. This is used by blending it into a silane group-containing olefin resin before molding, or by applying a solution or dispersion of a silanol condensation catalyst to the silane group-containing olefin resin after molding or impregnating it. The amount of these silanol condensation catalysts used is about 0.001 to 10 parts by weight, preferably 0.00, to 100 parts by weight of the silane group-containing olefin resin.
5 to 5 parts by weight.

When the molded article is exposed to a water atmosphere, the molded product is kept at room temperature to about 200 ° C., usually at room temperature to about 100 ° C. (liquid or vapor) for about 10 seconds to 1 week, usually about 1 minute to
It may be contacted for about one day.

In the present invention, an unmodified polyolefin, ethylene / vinyl acetate copolymer, ethylene / methyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene methacrylic acid is added to the above silane group-containing olefin resin. Methyl copolymer, ethylene / propylene copolymer rubber, ethylene / butene-1 copolymer rubber, ethylene / propylene / diene copolymer rubber and the like can be contained in a proportion of 30% by weight or less. In addition, 0.05 to 5% by weight of various compounding agents such as antioxidants, lubricants, UV inhibitors, antistatic agents, copper damage inhibitors, flame retardants and pigments, or talc, calcium carbonate, glass fiber, etc. You may mix | blend in the ratio of -50 weight%.

Molded Article A molded article is formed into a film, sheet, container, box or the like by extrusion molding, injection molding, vacuum molding, hollow molding or the like. or,
As a laminate structure of a silane-modified olefin resin layer and another thermoplastic resin layer such as polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polyamide, polybutylene terephthalate, polyethylene terephthalate, polyphenylene sulfide, polyphenylene ether, or polycarbonate. Is also good. Further, the film or sheet may be stretched.

The thickness of the molded product is 5 to 2 in the film.
00 μm, in the sheet 200 to 1,500 μm,
300-2,5 in housings such as small containers and boxes
It is generally 1 to 10 mm in a 00 μm, tank container, and 20 liter chemical container.

If necessary, the molded article may be subjected to corona discharge treatment, ozone treatment, glow discharge treatment, plasma treatment, or oxidation treatment with a chemical agent on the surface of the silane-modified olefin resin. However, in general, a thin film of an inorganic oxide is often vapor-deposited together with these oxidation treatments, and thus it is not necessary to perform the oxidation treatment during or after the molding.

Vapor Deposition of Inorganic Oxide Thin films of inorganic oxide include SiO _x , SnO _x , and Zn.
O _X, 200 to 4,000 Angstroms, such as IrO _X, is preferably utilized as a 300 to 3,000 angstroms. The thickness of the vapor-deposited film of 200 to 4,000 Å is limited by transparency, vapor deposition rate, gas barrier property, film winding property, and the like.

As the vapor deposition method, a high frequency induction heating method is used.
Molded product under vacuum (1 x 10 ^-3~ 1 x 10^-6toe
Method for depositing an inorganic oxide (Japanese Patent Publication No. 53-129).
No. 63); volatilized in a vapor deposition machine which was evacuated and evacuated in advance.
Gas flow containing organosilicon compounds, oxygen and inert gas
To generate plasma by magnetron glow discharge
SiO_xMethod of depositing the
Kai 64-87772, USP 4,557,946
No., USP 4,599,678) and the like. Also, 19
Industrial materials published in November 1990, Vol. 38, No. 14
Pages 104-105, ion plating method, high frequency
Plasma CVD method, electron beam (EB) vapor deposition method, spatter
It is classified as the Taling method and its principle is introduced.
It

[0030]

The present invention will be described in detail below with reference to examples, but the scope of the present invention is not particularly limited thereby.

The preparation of the silane group-containing olefin resin Examples Example 1 density 0.90 g / cm ^3, melting point 168 ° C., and a melt flow rate (MFR) 0.32g / 10 min powdered isotactic polypropylene, the Polypropylene 100
0.8 parts by weight of benzoyl peroxide, 4 parts by weight of vinyltrimethoxysilane, and 0.3 parts by weight of 2,6-di-t-butyl-4-methylphenol are mixed with 2 parts by weight with a mixing stirrer for 2 minutes. After doing, screw diameter 40m
m, L / D25 extruder was melt-kneaded at 210 ° C. to produce vinyltrimethoxysilane-modified polypropylene grafted with vinyltrimethoxysilane. The melt flow rate of this silane-modified polypropylene was 6 g / 10 minutes, and the unit concentration based on vinyltrimethoxysilane was 3.1% by weight.

Example 2 97 parts by weight of granular polyethylene having a density of 0.952 g / cm ³ , a melting point of 134 ° C. and a melt index (MI) of 2.5 g / 10 min, a density of 0.952 g / cm ³ , and an MI of 1. 5 g / 10 min of powdered polyethylene (3 parts by weight), dicumyl peroxide (0.075 parts by weight), and vinyltriethoxysilane (2 parts by weight) were mixed for 2 minutes, and the mixture was melt-kneaded by an extruder and then formed into a strand. And pelletized into vinyltriethoxysilane-grafted polyethylene pellets. This vinyltriethoxysilane-modified polyethylene has an MI of 0.9 g / 10
Minutes, the unit concentration based on vinyltriethoxysilane is 1.
It was 4% by weight.

Example 3 A mixture of ethylene, γ-methacryloxypropyltrimethoxysilane and propylene as a chain transfer agent was inserted into an autoclave equipped with a stirrer having an internal volume of 1.5 liters, and as a polymerization initiator. t-Butylperoxyisobutyrate was added, and the pressure was 2200 kg / cm.
² , an ethylene / γ-methacryloxypropyltrimethoxysilane copolymer was obtained under the condition of a temperature of 220 ° C.
This copolymer had MI of 1.2 g / 10 minutes and a unit concentration of 1.1% by weight based on γ-methacryloxypropyltrimethoxysilane.

Example 1 The vinyltrimethoxysilane-modified polypropylene obtained in Example 1 was melted at 240 ° C. in an extruder and then melted at 238 ° C. from a T-die.
Was extruded into a sheet shape with and was cooled to 60 ° C. with a metal roll to obtain a sheet having a thickness of 1 mm. This sheet was heated to 127 ° C. and stretched 5 times in the machine direction by utilizing the peripheral speed difference of the roll group. Then, it is introduced into a tenter oven, reheated to 157 ° C., and then stretched 10 times in the transverse direction using a tenter,
Annealing treatment at 163 ° C. and corona discharge treatment were performed to obtain a biaxially stretched film having a thickness of 20 μm.

This biaxially stretched film subjected to corona discharge treatment was placed in a plasma vapor deposition apparatus, and the inside of the apparatus was 1 × 10 ^−6.
After reducing the pressure of Toll, a mixed gas of 3 parts by volume of hexamethyldisiloxane, 3 parts by volume of oxygen, and 30 parts by volume of helium was introduced, and glow discharge was performed from the unbalanced magnetron to generate plasma to generate SiO ₂ . The thin film was deposited on a biaxially stretched film.

The conditions of glow discharge during vapor deposition are as follows:
Oxygen permeability of iO ₂ vapor-deposited biaxially stretched film is 5.0 cc
/ M ² · atm · day (JIS 1707-35).

Example 2 20 parts by weight of the vinyltrimethoxysilane-modified polypropylene obtained in Example 1 was added to unmodified polypropylene (MFR 2 g).
/ 10 minutes, density 0.90 g / cm ³ ) diluted with 80 parts by weight (unit concentration of silane compound is 0.62% by weight)
And unmodified polypropylene (MFR 0.8g / 10
And a density of 0.905 g / cm ³ ) are melted at 230 ° C. by separate extruders and fed to one die, which is layered in the die and extruded to form a vinyltrimethoxysilane-modified polypropylene layer. A two-layer sheet having a thickness of 0.1 mm, an unmodified polypropylene layer having a thickness of 0.9 mm, and a total thickness of 1 mm is prepared, and then stretched in the same manner as in Example 1 to have a thickness of 20 μm. A film was prepared, and after the vinyltrimethoxysilane-modified polypropylene layer side was subjected to corona discharge treatment, a SiO ₂ vapor-deposited biaxially stretched laminated film was produced in the same manner as in Example 1.

Comparative Example 1 Unmodified polypropylene (MFR 0.8 g / 10 min, dense polypropylene)
Degree 0.905g / cm ³) Vinyltrimethoxysilane
Example 1 except that the modified polypropylene was used instead.
Similarly, SiO₂A vapor deposited biaxially stretched film was produced.

Example 3 The vinyltriethoxysilane-modified polyethylene obtained in Example 2 was melted in an extruder at 180 ° C.
After extruding into a bubble shape at 0 ° C., blowing air into the bubble to expand it to a blow ratio of 2, a corona discharge treatment was performed to obtain an inflation film of vinyltriethoxysilane-modified polyethylene having a thickness of 40 μm. Using this film, a SiO ₂ vapor-deposited vinyltriethoxysilane-modified polyethylene film was produced in the same manner as in Example 1.

Example 4 100 parts by weight of the ethylene / γ-methacryloxypropyltrimethoxysilane copolymer obtained in Example 3 was added with 0.02 part by weight of dibutyltin dilaurate instead of the vinyltriethoxysilane-modified polyethylene. A SiO ₂ vapor-deposited film was produced in the same manner as in Example 3 except that the above was used.

Comparative Example 2 SiO ₂ vapor deposition was carried out in the same manner as in Example 3 except that unmodified low density polyethylene (MI 2 g / 10 min, density 0.920 g / cm ³ ) was used instead of vinyltriethoxysilane modified polyethylene. A polyethylene film was produced.
The oxygen permeability of all the stretched films was 5.0 cc /
The glow discharge conditions were changed so that m ² · atm · day.

Evaluation (1) Change with respect to external stress The SiO ₂ vapor-deposited films obtained in Examples 1 to 4 and Comparative Examples 1 to 3 were used in a gel botester manufactured by Meitetsu Keiki Co., Ltd.
After rolling the film into a tube shape, both ends of the tube were fixed to a gripping device of a tester, and a twist of ± 90 ° was repeated 10 times, and then the oxygen transmission rate was measured. The measured values are shown in Table 1.

(2) Changes in secondary processing SiO obtained in Examples 1 and 2 and Comparative Examples 1 and 2₂Evaporation
SiO of film₂Using a laminator device on the vapor deposition surface,
MI 5g / 10min, density 0.922g / cm ³Low density
20μm thick film of polyethylene at 320 ℃
It was extruded from a T-die and laminated. This lami
Table 1 shows the oxygen permeability of the nate.

[0044]

[Table 1] * Unit: cc / m ² · atm · day

[0045]

EFFECTS OF THE INVENTION The molded product of the silane-modified olefin resin on which the inorganic oxide is vapor-deposited according to the present invention is a resin molded product whose gas barrier property does not deteriorate even when heat or force is applied during secondary processing or during use. . Therefore, retort pouch packaging, IC
It is useful as a packaging material.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication location C08J 7/06 CES Z (72) Inventor Masaki Kitagawa 1 Toho-cho, Yokkaichi-shi, Mie Mitsubishi Petrochemical Co., Ltd. Inside the Yokkaichi Research Institute

Claims (1)

[Claims] 1. A compound represented by the general formula (I): embedded image RSiR ′ _n Y _3-n (I) (wherein R is an ethylenically unsaturated hydrocarbon group or a hydrocarbonoxy group, and R ′ is an aliphatic saturated hydrocarbon group). A hydrocarbon group, Y represents a hydrolyzable organic group,
n represents 0, 1 or 2. ) A silane group-containing olefin resin obtained by copolymerizing an ethylenically unsaturated silane compound having a hydrolyzable organic group with a polyolefin, or a silane group-containing resin obtained by copolymerizing the silane compound with ethylene. An olefin resin,
The unit concentration of the silane compound in the resin is 0.01 to
An olefin resin molded product having a bath barrier property, characterized in that an inorganic oxide thin film is formed on the surface of a silane group-containing olefin resin molded product of 10% by weight.