JPS649191B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for manufacturing coated plastic bottles.
More specifically, it is a coating that has excellent barrier properties against gases such as nitrogen and carbon gases, oxygen and water vapor, particularly in the combination of oxygen barrier properties and moisture resistance, and in particular has significantly improved humidity dependence of oxygen barrier properties. Concerning the manufacturing method of plastic bottles. Plastic bottles made by melt extruding and blow molding thermoplastics such as polyolefin are lighter than glass bottles and have superior impact resistance, so they are used in various fields as an alternative to glass bottles. It has come to be used in Although general-purpose plastics such as polyolefins have excellent moisture resistance and anti-oxidant properties, they have a relatively high oxygen permeability coefficient, and oxygen permeation through the bottle wall occurs at a non-negligible level, making it difficult for food products to be stored. It is unsuitable for containers intended for long-term storage or containers for cosmetics that require fragrance retention. In order to improve this drawback, plastic bottles whose walls are made of resin with excellent oxygen barrier properties have already been developed. Currently, the resin with the best oxygen barrier properties among melt-extrudable thermoplastic resins is saponified ethylene-vinyl acetate copolymer (ethylene-vinyl alcohol copolymer), but this saponified copolymer , they have poor moisture resistance, that is, water vapor barrier properties, and their oxygen permeability coefficients tend to increase significantly as humidity increases.Thus, when used in actual plastic bottles, it is necessary to layer them with moisture-resistant resins such as polyolefins in a sandwich-like manner. There is a molding hassle in that the bottle must be used in the form of a multilayer laminate. Conventionally, it has been well known that vinylidene chloride resin has excellent gas barrier properties, and it is also well known that this vinylidene chloride resin is used as a gas barrier layer for films or containers. For example, various films coated with vinylidene chloride resin are known as Saran-coated films, and Japanese Patent Application Laid-Open No. 93976/1983 describes a layer of vinylidene chloride resin as an intermediate layer and an ethylene-vinyl acetate copolymer-ionomer mixture layer. Coextruded and then biaxially stretched films are described as at least one surface layer. Furthermore, in Japanese Utility Model Application Publication No. 53-83339, vinylidene chloride resin is coextruded as a gas barrier intermediate layer, polyolefin is used as an inner and outer surface layer, and ethylene-vinyl acetate copolymer or a partially saponified product thereof is coextruded as an adhesive layer. A container made of synthetic resin is described. However, when vinylidene chloride resin is coextruded as a gas barrier layer, a problem arises in terms of heat resistance. That is, vinylidene chloride resin is
At temperatures above 190°C, thermal decomposition easily occurs, and this thermal decomposition not only causes a decrease in mechanical properties, but also
This results in a significant decrease in gas barrier properties. On the other hand, when coating with vinylidene chloride resin, it is difficult to make the coating layer thick enough, so the gas barrier properties obtained are still insufficient, and the adhesion to the resin substrate is also unsatisfactory. be. The present inventors have obtained 99 to 70% by weight of vinylidene chloride, 1 to 30% by weight of at least one of acrylic or methacrylic monomers, and 0 to 70 parts by weight based on 100 parts by weight of the total amount of the monomers. A copolymer composed of 100 parts by weight of other ethylenically unsaturated monomers exhibits excellent adhesion to the resin substrate constituting plastic bottles when applied in the form of an aqueous latex or solution. It has been found that the gas barrier properties of plastic bottles can be significantly improved by aging the coating layer formed. According to the invention, on at least one surface of a plastic bottle substrate made of a melt-formable thermoplastic resin, 99 to 70% by weight of vinylidene chloride, 1
30% by weight of at least one acrylic or methacrylic monomer and the total amount of the above monomers
Substantially composed of 0 to 100 parts by weight of at least one other ethylenically unsaturated monomer per 100 parts by weight, and having an oxygen permeability coefficient of 9 x 10 ^-14 cc at 20°C and 100% RH.・cm/ ^cm2・sec・cm・
A method for manufacturing a plastic bottle with a coating layer mainly composed of a copolymer having a Hg or less and a water vapor permeability coefficient (JIS Z-0208) of 3×10 ^-3 g・cm/m ²・day or less, the method comprising: The coating layer is formed by applying and drying an aqueous latex or organic solvent solution of the copolymer, and after drying the coating film, the coating layer is formed at a temperature of 30 to 120°C for a period of 30 seconds to 7 days, and tends to be 120°C. Provided is a method for producing a coated plastic bottle, characterized in that it is aged for 30 seconds and at 30° C. for 7 days. According to the present invention, the vinylidene chloride copolymer is applied to a plastic bottle substrate in the form of an aqueous latex or an organic solvent solution and dried to form a coating layer, thereby achieving adhesion without being affected by thermal decomposition. It is possible to easily form a gas barrier layer with excellent gas barrier properties, and by subjecting the formed coating layer of the copolymer to an aging treatment, the gas barrier properties of plastic bottles can be improved approximately 2 to 4 times (gas permeability This fact will become clear by referring to Table 4 below. In FIG. 1 showing a coated plastic bottle of the present invention, the bottle 1 has a circumferential wall portion 2 having a circular or elliptical cross section, a bottle mouth portion 3 that is integrally connected to the circumferential wall portion 2, and a bottom portion 4 that is continuous to the lower end of the circumferential wall portion. All of these bottle walls consist of a plastic bottle substrate 5 formed from a melt-formable thermoplastic resin by means such as blow molding, injection molding or biaxial stretch blow molding, and a surface of the substrate. It consists of a vinylidene chloride-acrylic (methacrylic) copolymer coating layer 6 provided on. This coating layer 6 may be provided on both surfaces of the bottle substrate 5 as shown in FIG. 1, or may be provided only on the inner surface or only on the outer surface. The copolymer used as the coating layer in the present invention is 99%
Contains as essential components at least one of vinylidene chloride in an amount of 70 to 70% by weight, particularly 99 to 80% by weight, and 1 to 30% by weight, particularly 4 to 20% by weight of an acrylic or methacrylic monomer, and optionally the above-mentioned. It optionally contains up to 100 parts by weight of other ethylenically unsaturated monomers per 100 parts by weight of the total amount of monomers. As the above-mentioned acrylic or methacrylic monomer, acrylic acid, methacrylic acid or derivatives thereof are used, and preferred examples include the following formula: In the formula, R ₁ represents a hydrogen atom, a halogen atom, or a methyl group, and X represents a nitrile group (-C≡N) or a (In the formula, Y is an amino group, a hydroxyl group, an alkyloxy group, a cycloalkyloxy group, an aminoalkyloxy group, a hydroxyalkyloxy group, an alkoxyalkyloxy group, a haloalkyloxy group, a glycidyl group, an aryloxy group, an aralkyloxy group) is a group represented by ), especially acrylic acid, acrylonitrile,
Acrylamide, methyl acrylate, ethyl acrylate, methyl α-chloroacrylate, propyl acrylate, butyl acrylate, hexyl acrylate, octyl acrylate, cyclohexyl acrylate, glycidyl acrylate, -2 acrylate
-Hydroxyethyl, acrylic acid monoglyceride, phenyl acrylate, methacrylic acid, methacrylonitrile, methacrylamide, methyl methacrylate, amyl methacrylate, glycidyl methacrylate, methacrylic acid monoglyceride, 2-hydroxypropyl methacrylate, beta methacrylate
-methoxyethyl, β-aminoethyl methacrylate, and γ-N,N-diethylaminopropyl methacrylate. These acrylic or methacrylic monomers can be used alone or in combination of two or more. Particularly suitable acrylic or methacrylic monomers for the purpose of the present invention include (i) nitrile monomers such as acrylonitrile, methacrylonitrile, and α-chloroacrylonitrile, (ii) methyl acrylate, ethyl acrylate, Methyl methacrylate, methacrylic acid-2
- Ester monomers such as hydroxyethyl, glycidyl acrylate, glycyl methacrylate, acrylic acid monoglyceride, methacrylic acid monoglyceride, methoxyethyl acrylate, methoxyethyl methyl methacrylate, and (iii) the above (i) and (ii)
It is a combination monomer of Ethylenically unsaturated monomers other than vinylidene chloride and acrylic or methacrylic monomers include:
Vinyl aromatic monomers such as styrene and vinyltoluene; vinyl esters such as vinyl acetate and vinyl propionate; diolefins such as butadiene and isoprene; methyl vinyl ether, glycidyl allyl ether, vinyl chloride, ethylene trichloride,
Ethylene tetrachloride, vinyl fluoride, vinylidene fluoride, ethylene trifluoride, ethylene tetrafluoride, maleic anhydride, fumaric acid, vinyl succinimide,
Examples include vinylpyrrolidone, and these monomers may be used alone or in combination of two or more. Examples of suitable copolymers include, but are not limited to: Vinylidene chloride/acrylonitrile copolymer, vinylidene chloride/acrylonitrile/methacrylonitrile copolymer, vinylidene chloride/methacrylonitrile copolymer, vinylidene chloride/acrylonitrile/glycidyl acrylate copolymer, vinylidene chloride/acrylonitrile/glycidyl methacrylate Copolymer, vinylidene chloride/acrylonitrile/monoglyceride acrylate copolymer, vinylidene chloride/ethyl acrylate/glycidyl acrylate copolymer, vinylidene chloride/methyl methacrylate/styrene copolymer, vinylidene chloride/acrylonitrile/styrene copolymer combination, vinylidene chloride/acrylonitrile/ethylene trichloride copolymer, vinylidene chloride/acrylonitrile/vinyl chloride copolymer, vinylidene chloride/acrylonitrile/methacrylic acid monoglyceride/ethylene trichloride copolymer, vinylidene chloride/methoxyethyl methyl methacrylate/ Methyl methacrylate/ethylene trichloride copolymer. In terms of oxygen barrier properties, it is important for the polymer used in the present invention to have 70% by weight or more of vinylidene chloride units. In order to make this possible, it is important to contain at least 1% by weight of acrylic monomer or methacrylic monomer. Additionally, to improve adhesion to various plastic bottle substrates, formula In the formula, each of R ₂ and R ₃ is a hydroxyl group, and these two hydroxyl groups may be dehydrated to form an oxirane ring in an amount of 0.5 to 15% by weight based on the total monomers. It is desirable to use it in Furthermore, for the purpose of further improving moldability into plastic bottles, up to 100 parts by weight of other ethylenically unsaturated monomers may be added per 100 parts by weight of the total amount of vinylidene chloride and acrylic or methacrylic monomers. is allowed to contain. The copolymer used in the present invention is generally prepared by emulsifying or suspending the constituent monomers in an aqueous medium by the action of an emulsifier and a dispersant, and then carrying out emulsion polymerization or suspension polymerization in the presence of a radical initiator. can be easily obtained by As the radical initiator, peroxides, azo compounds, or redox catalysts, which are known per se, are used. The molecular weight of the polymer used in the present invention is generally sufficient as long as it has a molecular weight sufficient to form a film. The polymer used in the present invention is generally difficult to mold by hot melting, and is used in the form of an organic solvent solution or in the form of an aqueous emulsion or latex to coat plastic bottles by the method described below. The copolymer used in the present invention has a remarkable combination of oxygen barrier properties and moisture resistance, and is further characterized in that the dependence of the oxygen barrier properties on humidity is extremely low. That is, this copolymer is heated at 20℃,
Oxygen permeability coefficient at 100%RH 9×10 ^-14 cc・
cm/cm ² ·sec·cmHg or less, and the water vapor permeability coefficient (JISZ-0208) is 3×10 ^-3 g·cm/m ² ·day. The oxygen permeability coefficients and water vapor permeability coefficients of the resins conventionally used for molding plastic bottles and the copolymers used in the present invention are shown in Table 1 below.

【table】

[g・cm/m ²・day]

In the formula, h: coating thickness of polyvinylidene chloride resin [μ], Q _O2 : oxygen permeability of composite system [cc/m ²・day・
atm], (Q _O2 )B: Oxygen permeability of bottle matrix [cc/ ^m2・
day・atm〕 Q _H2O : Water vapor permeability of composite system [g/m ²・day], (Q _H2O ) B: Water vapor permeability of bottle substrate [g/m 2・day]
m ²・day], respectively. In the examples below, bottles with an "n" attached to each bottle symbol have a coating film that has been dried, but the coating film has not been aged. Those marked with a mark indicate those in which the coating film has been aged after drying. Reference example 1 Internal volume is 1000c.c., weight is 30g, average wall thickness is 0.45
An anchor coating agent (manufactured by Toyo Morton Co., Ltd., EL-220/EL-200-AD) was applied in advance to the outer surface of a biaxially stretched polypropylene bottle (cylindrical) of mm.
After heat treatment at 100°C for 30 seconds, a polyvinylidene chloride resin emulsion (dispersion medium: water, emulsifier: Poval, solid content concentration: 45%) having the composition ratio shown in Table 2 was coated by dip coating. .
Then in a perfect oven (explosion proof type) at 70℃.
and dried for 10 minutes. The average coating amount (average film thickness) of the polyvinylidene chloride resin coated is 11μ
It was hot. Oxygen permeability coefficients (hereinafter referred to as P _O2 ) and water vapor permeability coefficients (hereinafter referred to as P _H2O ) of the obtained four types of poly(vinylidene chloride/acrylonitrile) resin-coated biaxially oriented polypropylene bottles and bottles of uncoated biaxially oriented polypropylene alone. ) was determined according to the method described in the specification. The results are also shown in Table 2. The resin-coated bottles have lower P _O2 , compared to uncoated bottles.
It is known from Table 2 that the value of P _H2O clearly decreases, and that the value of P _H2O particularly decreases and the barrier properties improve when the composition ratio of vinylidene chloride (VdC) is 70% by weight or more. .

[Table] Note) Reference example of a single bottle made of biaxially oriented polypropylene that is not coated with polyvinylidene chloride resin 2 The outer surface of the biaxially oriented polypropylene bottle described in Reference Example 1 is coated with 90% by weight of vinylidene chloride (VdC), A polyvinylidene chloride resin emulsion (dispersion medium: water, emulsifier: Poval, solid content: 45%) having a composition ratio of 10% by weight of vinyl chloride (VC), 70% by weight of VdC, and 30% by weight of VC was coated. The coating method, drying method and coating amount were all the same as in the reference example. P _O2 of the two types of poly(vinylidene chloride/vinyl chloride) resin-coated polypropylene bottles obtained
and P _H2O were determined according to the method described in the specification. The results are shown in Table 3. As is clear from the comparison with Table 2, at the same composition ratio, the values are higher when the comonomer is vinyl chloride (VC) than when acrylonitrile (AN) is used (Table 2), and the barrier properties are inferior. It's on.

[Table] Reference example 2 Among the polyvinylidene chloride resins listed in the reference example, two types of emulsion with marks A and C were used for the outer layer with a vent equipped with a screw with a diameter of 40 mm and an effective length of 800 mm. Using an extruder, isotactic polypropylene was melt extruded according to the known coextrusion blow molding method using an inner layer extruder with a screw having a diameter of 65 mm and an effective length of 1430 mm. . At this time, the rotation speeds of the screws of the extruders for the outer layer and the inner layer were both 15 rpm. Further, the set temperature of the cylinder portion of each extruder and the set temperature of the two-layer die were both 170°C. Both of the two types of resin extrudates extruded as the outer layer turned black due to thermal decomposition and could not be blow-molded into bottles. Example 1 Internal volume is 500c.c., weight is 17g, average wall thickness is 0.50
Anchor coating agent (manufactured by Toyo Morton Co., Ltd., EL-220/EL-200-AD) was applied in advance to the inner surface of a mm high-density polyethylene bottle (elliptical) by dip coating method, and then heated at 80℃ for 5 minutes. After drying, a polyvinylidene chloride resin solution having a composition ratio of 90% by weight of vinylidene chloride (VdC), 5% by weight of acrylonitrile (AN) and 5% by weight of methacrylonitrile (MAN) (solvent: tetrahydrofuran, solid content concentration) ;20%) was coated by dip coating. Thereafter, it was dried in a perfect oven (explosion-proof type) at 70°C for 15 minutes. The average film thickness of the polyvinylidene chloride resin coating film is
It was 5μ. Next, the coated high-density polyethylene bottle was aged (heat treated) for 36 hours in a constant temperature bath set at 48°C. The poly(VdC/AN/
MAN) resin-coated high-density polyethylene bottles (hereinafter referred to as Ea) and uncoated high-density polyethylene bottles (hereinafter referred to as HDPE), P _O2 and P _H2O were determined according to the method described in the specifications. . The results are shown in Table 4. Example 2 Internal volume is 1000c.c., weight is 27g, average wall thickness is 0.35
70% by weight of vinylidene chloride and methyl acrylate on the inner and outer surfaces of a mm polyvinyl chloride bottle (cylindrical).
A polyvinylidene chloride resin latex (dispersion medium: water, emulsifier: sodium lignosulfonate, solid content concentration: 61%) having a composition ratio of 10% by weight and 20% by weight of glycidyl methacrylate was applied by dip coating. I coated it. Then in an air circulation oven
It was dried at 55°C for 60 minutes. The average film thickness of the polyvinylidene chloride resin coating coated on the inner and outer surfaces of the polyvinyl chloride bottle was 25 μm. Hereinafter, this bottle will be referred to as Fn. Furthermore, this Fn
The bottle was aged (heat treated) for 24 hours in a constant temperature bath set at 48°C. Hereinafter, this bottle will be referred to as Fa. Each bottle of Fn and Fa obtained in this way,
And for comparison, uncoated polyvinyl chloride single bottles (hereinafter referred to as PVC) were tested according to the method described in the specifications to determine their P _O2 and
P _H2O was determined. The results are shown in Table 4. Example 3 Internal volume is 400c.c., weight is 12g, average wall thickness is 0.30
An anchor coating agent (manufactured by Toyo Morton Co., Ltd., EL-220/EL-200-AD) was applied in advance to the outer surface of a mm polycarbonate bottle (cylindrical) by dip coating method, and dried at 70°C for 15 minutes. Later, a polyvinylidene chloride resin latex having a composition ratio of 96% by weight of vinylidene chloride, 2% by weight of methyl acrylate, and 2% by weight of glycidyl methacrylate (dispersion medium: water, emulsifier: rosin soap, solid content concentration: 37 %) was coated by spray coating method. It was then dried in an air circulation oven at 80°C for 2 minutes. The average film thickness of the polyvinylidene chloride resin coating coated on the outer surface of the polycarbonate bottle was 1.7 μm. This bottle is shown below.
It is written as Gn. Furthermore, this Gn bottle was aged (heat treated) for 24 hours in a constant temperature bath set at 48°C.
This bottle will be referred to as Ga below. The Gn and Ga bottles thus obtained, as well as the uncoated polycarbonate single bottle (hereinafter referred to as PC) for comparison, were analyzed for their P _O2 and P Asked for _H2O . The results are shown in Table 4. Example 4 Internal volume is 200c.c., weight is 18g, average wall thickness is 0.55
mm polymethyl methacrylate bottle (cylindrical)
A polyvinylidene chloride resin latex (dispersion medium: water, emulsifier: poval, Solid concentration: 51
%) was coated by brush application method. It was then dried in an air circulation oven at 90°C for 1 minute. The average film thickness of the polyvinylidene chloride resin coating coated on the outer surface of the polymethyl acrylate bottle was 15 μm. This bottle is then aged (heat treated) for 6 hours in a constant temperature bath set at 61℃.
did. Hereinafter, this bottle will be referred to as Ha. Regarding the Ha bottle obtained in this way and a bottle of uncoated polymethyl methacrylate alone (hereinafter referred to as PMMA) for comparison,
Their P _O2 and P _H2O were determined according to the method described in the specification. The results are shown in Table 4. Example 5 Internal volume is 200c.c., weight is 12g, average wall thickness is 0.50
The inner and outer surfaces of acrylonitrile-styrene-butadiene copolymer bottle (cylindrical) of mm are coated with vinyl chloride for a total of 100 parts by weight of 80% by weight vinylidene chloride, 10% by weight methyl acrylate, and 10% by weight acrylic acid monoglyceride. Polyvinylidene chloride resin latex having a composition ratio of 50 parts by weight (dispersion medium;
Water, emulsifier; gelatin, solid content concentration: 30%) was coated by dip coating. It was then dried in an air circulation oven at 40°C for 60 minutes. The average film thickness of each of the polyvinylidene chloride resin coatings coated on the inner and outer surfaces of the acrylonitrile-styrene-butadiene copolymer bottle was 2.8 μm.
Furthermore, this bottle was placed in a thermostat set at 30℃ for 7 hours.
Aging (heat treatment) was performed for one day. This bottle below
It is written as Ja. The Ja bottle obtained in this way and, for comparison, a bottle of uncoated acrylonitrile-styrene-butadiene copolymer (hereinafter referred to as ABS)
), their P _O2 and P _H2O were determined according to the method described in the specification. The results are shown in Table 4. Comparative example 1 Internal volume is 200c.c., weight is 12g, average wall thickness is 0.50
The inner and outer surfaces of acrylonitrile-styrene-butadiene copolymer bottle (cylindrical) of mm are coated with vinyl chloride for a total of 100 parts by weight of 80% by weight vinylidene chloride, 10% by weight methyl acrylate, and 10% by weight acrylic acid monoglyceride. Polyvinylidene chloride resin latex having a composition ratio of 150 parts by weight (dispersion medium: water, emulsifier: gelatin, solid content concentration: 30%)
was coated by dip coating. It was then dried in an air circulation oven at 40°C for 10 hours. The average film thickness of each of the polyvinylidene chloride resin coatings coated on the inner and outer surfaces of the acrylonitrile-styrene-butadiene copolymer bottle was 3.5 μm. Furthermore, this bottle was aged (heat treated) for 7 days in a constant temperature bath set at 30°C. This bottle will be referred to as Ka below. Regarding the bottle of Ka obtained in this way,
Their P _O2 and P _H2O were determined according to the method described in the specification. The results are shown in Table 4. Example 6 Internal volume is 200c.c., weight is 23g, average wall thickness is 0.85
mm attack polystyrene bottle (cylindrical)
An anchor coating agent (manufactured by Toyo Morton Co., Ltd., EL-220/EL-200-AD) was applied in advance to the outer surface of the film using a spray coating method, and after drying at 80°C for 10 minutes, 75% by weight of vinylidene chloride, A combination method of spraying and brushing a polyvinylidene chloride resin latex (dispersion medium: water, emulsifier: POVAL, solid content concentration: 50%) having a composition ratio of 20% by weight of methoxyethyl acrylate and 5% by weight of acrylic acid. Coated with It was then dried in an air circulation oven at 110°C for 30 seconds. The average film thickness of the polyvinylidene chloride resin coating coated on the outer surface of the attacking polystyrene bottle is
It was 15μ. Hereinafter, this bottle will be referred to as Ln. Furthermore, this Ln bottle was placed in a constant temperature oven set at 60℃ for 24 hours.
Time-aged (heat treated). This bottle below
It is written as La. Each bottle of Ln and La obtained in this way,
And for comparison, uncoated bottles of attractive polystyrene (hereinafter referred to as PS) were tested according to the method described in the specification.
P _O2 and P _H2O were determined. The results are shown in Table 4.

【table】

[Table] Example 7 Internal volume is 1000c.c., weight is 45g, average wall thickness is 0.54mm
On the inner surface of a biaxially oriented polyethylene terephthalate bottle (cylindrical), 83% by weight of vinylidene chloride, 14% by weight of methoxyethylmethyl methacrylate,
A polyvinylidene chloride resin latex (dispersion medium;
Water, emulsifier: Poval, solid content: 47%) were coated by dip coating. It was then dried in an air circulation oven at 70°C for 10 minutes. The average film thickness of the polyvinylidene chloride resin coating coated on the inner surface of the biaxially oriented polyethylene terephthalate bottle was 10 μm. Hereinafter, this bottle will be referred to as Nn. Furthermore, this Nn bottle was aged (heat treated) for 48 hours in a constant temperature bath set at 48°C. Hereinafter, this bottle will be referred to as Na. Each bottle of Nn and Na obtained in this way, and for comparison, a bottle of uncoated biaxially oriented polyethylene terephthalate (hereinafter referred to as 10PET)
), their P _O2 and P _H2O were determined according to the method described in the specification. The results are shown in Table 4. On the other hand, for each of these Nn, Na, and 10PET bottles, the carbon dioxide gas permeability coefficient (P _CO2 ) was calculated. However, the temperature in this case is 27℃,
Humidity was 0%RH and 91%RH. The results are shown in Table 5.

[Table] Furthermore, fill each of these Nn and Na bottles (5 bottles each) with 900 c.c. of tap water, cover the mouth with a cap, and then place it on the concrete surface from a height of 2 m for up to 100 c.c.
A repeated drop test was conducted. No cracking or peeling of the polyvinylidene chloride resin from the bottle substrate (10PET) occurred in any of the bottles. Example 8 External surface area is 130 cm ² Weight is 62.5 g, average wall thickness is
The vinylidene chloride resin latex described in Example 7 was applied as a solid content to the inner surface of a 36.0 mm preform (bottomed parison) made of amorphous polyethylene terephthalate by dip coating.
0.22g was coated. Then, using a known biaxial stretch blow molding machine, biaxial stretch blowing was performed after heating at 100°C for 20 seconds, and the polyvinylidene chloride-based material had an internal volume of 2000 c.c. and a total average wall thickness of about 0.50 mm. A biaxially oriented polyethylene terephthalate bottle whose inner surface was coated with resin (average coating film: 1.4μ) was obtained. Hereinafter, this bottle will be referred to as Pn. Add this Pn bottle to 48
Aging (heat treatment) was performed for 48 hours in a constant temperature bath set at ℃. Hereinafter, this bottle will be referred to as Pa. Each bottle of Pn and Pa obtained in this way,
And for a comparative uncoated biaxially oriented polyethylene terephthalate bottle (hereinafter referred to as 20PET), P _O2 and P _H2O were determined according to the method described in the specification. The results are shown in Table 4. On the other hand, for each of these Pn, Pa and 20PET bottles, the carbon dioxide permeability coefficient ( P _CO2 ) was determined. However, the temperature in this case is 27℃,
Humidity was 0%RH and 91%RH. The results are shown in Table 6.

[Table] Furthermore, each of these Pn and Pa bottles (10 each) was filled with 1950 c.c. of tap water, the mouth was covered with a cap, and then left in an atmosphere at 5°C for 48 hours. After that, we conducted a repeated drop test up to five times on a concrete surface from a height of 1.8 meters. No cracking or peeling of the polyvinylidene chloride resin from the bottle substrate (20PET) occurred in any of the bottles. Example 9 External surface area is 130 cm ² , weight is 62.5 g, average wall thickness is
The outer surface of a 36.0 mm preform (bottomed parison) made of amorphous polyethylene terephthalate was coated with a solid content of 0.96 g of the polyvinylidene chloride resin latex described in Example 7 by dip coating. It was then dried in an air circulation oven at 70°C for 5 minutes. Then, using a known biaxial stretch blow molding machine, biaxial stretch blowing was performed after heating at 100°C for 20 seconds, and the internal volume was 2000.
cc, a biaxially stretched polyethylene terephthalate bottle having a total average wall thickness of about 0.50 mm and whose outer surface was coated with the polyvinylidene chloride resin (average coating thickness 6.1 μm) was obtained. Hereinafter, this bottle will be referred to as Rn. Furthermore, this Rn bottle was aged (heat treated) for 48 hours in a constant temperature bath set at 48°C. This bottle below
It is written as Ra. P _O2 and P _H2O were determined for each of the Rn and Ra bottles thus obtained according to the method described in the specification. The results are shown in Table 4. On the other hand, the carbon dioxide gas permeability coefficient (P _CO2 ) of the polyvinylidene chloride resin was determined for each of these Rn and Ra bottles according to the method described in Example 7. The results are shown in Table 7.

[Table] Example 10 An isotactic polypropylene sheet with a width of 30 cm and a thickness of 0.8 mm was air-formed at a temperature of 148°C using the plug-assisted air-forming method to form a sheet of 9.7 cm in the vertical direction and 9.7 cm in the horizontal direction. Direction is 9.7cm, height is
A square wide-mouth bottle of 3.2 cm and an average wall thickness of 0.47 mm was obtained. The anchor coating agent described in the reference example was applied to the inner surface of the obtained wide-mouth bottle, and the mixture was heated at a temperature of 100°C.
After heat treatment for 30 seconds, the polyvinylidene chloride resin latex described in Example 7 was coated by dip coating, and then dried for 30 seconds in an air circulation oven set at 140°C. The average thickness of the polyvinylidene chloride resin layer coated on the inner surface of the isotactic polypropylene was 10 μm. Hereinafter, this wide mouth bottle will be referred to as Yn. Furthermore, this Yn bottle was aged (heat treated) for 24 hours in a constant temperature bath set at 48°C. Below is this wide mouth bottle.
Written as Ya. The thus obtained wide-mouth bottles of Yn and Ya, and for comparison, the wide-mouth bottle of uncoated polypropylene alone (hereinafter referred to as PP-WM)
The bottom part was cut into a disk shape and used as a measurement sample.
and those according to the method described in the specification.
P _O2 and P _H2O were determined. The results are shown in Table 8. Due to the barrier effect of the polyvinylidene chloride resin of the present invention, the oxygen resistance and water vapor permeability of the coated bottle are significantly improved, and the barrier properties of the vinylidene chloride resin are further improved by heat treatment. Table 8
known from. Example 11 One side of a polyethylene terephthalate sheet with a width of 30 cm and a thickness of 1.5 mm was coated with the polyvinylidene chloride resin latex described in Example 7 four times using a brush coating method, and then coated using an air circulation oven. It was dried at 70°C for 20 minutes. The average thickness of the coated polyvinylidene chloride resin layer is 28μ
It was hot. The thus obtained sheet was air-pressed at a temperature of 107°C using a plug-assisted air-forming method so that the coated surface became the inner surface.
Diameter is 8.5cm, height is 10cm, total average wall thickness is 0.42mm
(The thickness of the polyvinylidene chloride resin layer is 8.0μ)
A cylindrical wide-mouthed bottle (the inner surface was made of the above-mentioned polyvinylidene chloride resin) was obtained. Hereinafter, this wide mouth bottle will be referred to as Zn. Furthermore, this Zn bottle was aged (heat treated) for 5 days in a thermostatic oven set at 40°C. Hereinafter, this wide mouth bottle will be referred to as Za. The wide-mouth bottles of Zn and Za obtained in this way, and the wide-mouth bottle of uncoated polyethylene terephthalate alone for comparison (hereinafter referred to as
The bottom part of the PET-WM) was cut into a disk shape and used as a measurement sample. Then, their P _O2 and P _H2O were determined according to the method described in the specification. The results are shown in Table 8. A similar trend as in Example 10 is known from Table 8.

[Table] Example 12 Using the apparatus described in Japanese Patent Application No. 54-99480 and following the method described in said publication, a cylindrical material with a diameter (inner diameter) of 7.0 cm and a height of 10 cm, In addition, a wide-mouth bottle with a two-layer structure was molded. The outer layer of this wide mouth bottle has a melt index (ASTM D-1238).
The inner layer of the bottle is a mixture of 80 parts by weight of calcium carbonate per 100 parts by weight of isotactic polypropylene at 6.5 g/10 min, and the inner layer of the bottle has a melt index of 0.5 g/10 min per 100 parts by weight of high-density polyethylene. It was composed of a mixture of 40 parts by weight of naturally occurring phlogopite with a specific surface area of about 400 m ² /g, and the outer layer had a thickness of 0.4 mm and the inner layer had a thickness of 0.4 mm. The outer surface of the resulting wide-mouth bottle was coated with the polyvinylidene chloride resin latex described in Example 7 by dip coating, and then dried for 2 minutes in an air circulation oven set at 100°C. The average thickness of the polyvinylidene chloride resin layer coated on the outer surface of the two-layer outer layer (the isotactic polypropylene mixture layer) was 24 μm. Hereinafter, this wide mouth bottle will be referred to as QYn. Furthermore, this QYn
The bottle was aged (heat treated) for 24 hours in a constant temperature bath set at 60°C. Below is this wide mouth bottle.
Write it as QYa. The bottom portions of the QYn and QYa wide-mouth bottles obtained in this way, as well as the uncoated two-layer wide-mouth bottle (hereinafter referred to as QY-TM) for comparison, were cut out into disk-shaped samples for measurement. And so. Then, their P _O2 and P _H2O were determined according to the method described in the specification. The results are shown in Table 9. A similar trend as in Example 10 is known from Table 9.

[Table] Example 13 A non-aging (heat treatment) bottle was produced in the same manner as in Example 7. These bottles were placed in a thermostatic oven at 120°C for 10 seconds and 30 seconds, and in a thermostatic oven at 150°C for 10 seconds and
Aging (heat treatment) was performed for 30 seconds. The vinylidene chloride resin coating on the bottle did not change at 120°C, but at 150°C it turned brown, and the color changed significantly after 30 seconds. However, aging at 120° C. for 30 seconds is included within the scope of the present invention and is shown for comparison with comparative examples. For each aged bottle, the carbon dioxide permeability coefficient (P _CO2 ) was determined using the same conditions and method as in Example 7. Further, in the same manner as in Example 7, five bottles each were filled with tap water and a drop test was performed under the same aging conditions. Carbon dioxide permeability coefficient and drop test results,
It is listed in Table 10 along with the aging conditions.

[Table] Comparative Example 2 Coating treatment was performed under the same conditions as in Example 2 except that the aging (heat treatment) temperature was 20°C, and the Po ₂ and PH ₂ were treated according to the method described in the specification. I asked for O. The results are shown in Table 11.

【table】 [Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing a coated plastic bottle of the present invention, in which reference numeral 1 is the bottle, 2 is the peripheral wall, 3 is the bottle mouth, 4 is the bottom, 5 is the plastic bottle substrate, and 6 is the bottle. Each coating layer is shown.

Claims (1)

[Claims] 1. On at least one surface of a plastic bottle substrate made of a melt-moldable thermoplastic resin, 99 to 70% by weight of vinylidene chloride, 1 to 30% by weight of at least one of acrylic or methacrylic monomers, and the above-mentioned. It consists essentially of at least one other ethylenically unsaturated monomer in an amount of 0 to 100 parts by weight based on 100 parts by weight of the total amount of monomers, and has an oxygen permeability coefficient at 20°C and 100% RH. 9×10 ^-14 cc・cm/cm ²・sec・cmHg or less and water vapor permeability coefficient (JIS・Z-0208) of 3×10 ⁻³ g・
A method for manufacturing a plastic bottle provided with a coating layer mainly composed of a copolymer having a thickness of cm/m ²・day or less,
The coating layer is formed by applying and drying an aqueous latex or organic solvent solution of the copolymer, and after drying the coating film, the coating layer is formed at a temperature of 30 to 120°C for a period of 30 seconds to 7 days, and tends to be 120°C. Well then
A process for producing a coated plastic bottle, characterized in that it is aged for 30 seconds and at 30°C for 7 days.