JP2003011276A - Resin coated metal vessel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin coated metal vessel formed by processing a metal plate coated with a resin composition having high hiding properties and being excellent in moldability. SOLUTION: The resin composition is prepared by a process wherein 10-50 mass % of polar white inorganic particles having polarity are added to a mixture comprising a polyester resin having intrinsic viscosity of 0.3 dl/g or above and a vinyl polymer containing 1 mass % or above of a polar unit. The composition is applied on at least one surface of the metal plate directly or after it is processed into a film. Then, the metal plate is formed into the resin coated metal vessel. In the vessel, the number of the inorganic particles unevenly distributed on the interface between the polyester resin and the vinyl polymer is 20% or above of all the inorganic particles and/or the number of layers of the interface between the polyester resin and the vinyl polymer where the inorganic particles are unevenly distributed is 20% or above of the total number of layers of the interface.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a resin-coated metal container.

[0002]

2. Description of the Related Art Polyester resins are excellent in mechanical properties, electrical properties, and heat resistance and are widely used as molding materials for automobile parts, parts of electric products, casings and the like. further,
It has excellent lubrication during processing, abrasion resistance, gas barrier property of metal corrosion factor substances such as water vapor and oxygen, and adhesion to metal, improving corrosion resistance and processability, and giving surface design It is also widely used as a metal coating material for the purpose of

When a polyester resin is used as a coating material for a metal material, as a method for further improving these properties, a polyester resin is used as disclosed in JP-A-7-195617 and JP-A-7-290644. A method of alloying with an ionomer resin is known. In this method, the ionomer resin improves mechanical properties and adhesion to metal. Furthermore, as disclosed in WO99 / 27026, a rubber elastic resin is further added to a resin composition of the above polyester resin and a vinyl polymer having a polar group such as an ionomer to form a polyester resin polar group. A technique for finely dispersing a rubber-like elastic body in which an elastic resin is encapsulated by the vinyl polymer has been disclosed, and it is known that impact resistance and thermal stability are further improved.

In addition to the above-mentioned characteristics, the resin used for coating the outer surface of the metal container, particularly the film, has a high concealing property in order to omit the undercoating of the white paint which has been conventionally used. There is a need for a white film that can be used, has a beautiful appearance and is suitable for printing. For example, in order to develop the hiding property in a white film made of a polyester resin, a method of adding white pigment particles at a high concentration, a method of forming a white film having different pigment concentrations into a multilayer, a method of containing fine bubbles in the film, etc. Is mentioned. When high concealing property is given by the method of increasing the amount of pigment added, the film itself becomes brittle and frequently breaks during processing, and the film cannot withstand molding, causing cracks and cracks. Becomes In addition, as a countermeasure against these problems, a method of multilayering white films with different pigment concentrations has been proposed, but it requires a process such as multilayering of thin film, and in some cases, a film interface that is multilayered during severe molding processing is required. In some cases, peeling may occur. Further, in the case of providing a high hiding property by a method of containing a large amount of fine bubbles, it is necessary to control the size of the bubbles, and the obtained film generally has poor moldability. It is possible to increase the concealing property by increasing the thickness, but this is not a preferable method because it leads to an increase in film cost. Therefore, a white film having both contradictory properties such as high concealing property and excellent moldability is further desired as the molding processing speed of containers and the like is improved and the design property to be imparted is diversified.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and has a particularly high concealing property,
It is an object of the present invention to provide a resin-coated metal container obtained by processing a metal plate coated with a resin composition that has the contradictory characteristic of being excellent in moldability.

[0006]

Means for Solving the Problems In order to solve the above problems, the present inventors further studied a resin composition of the above polyester resin and a vinyl polymer having a polar group such as an ionomer, and as a result, The resin composition, by adding a specific amount of white inorganic particles having a specific polarity, increases the interfacial adhesion between the polyester resin and the vinyl resin having a polar group such as the ionomer, resulting in a high The inventors have found that they can have contradictory properties such as hiding power and excellent moldability, and have completed the present invention.

That is, the present invention provides a unit having a polyester resin having an intrinsic viscosity of 0.3 dl / g or more and a polar group.
A mixture containing a vinyl polymer containing more than mass%, a resin composition obtained by adding 10 to 50 mass% of polar white inorganic particles, directly and / or after processing into a film, at least one surface of the metal plate Is a resin-coated metal container formed by molding and processing the metal plate, wherein the number of the inorganic particles unevenly distributed at the interface between the polyester resin and the vinyl polymer is 20% or more of all the inorganic particles, and / Alternatively, the resin-coated metal container is characterized in that the number of interface layers of the polyester resin and the vinyl polymer in which the inorganic particles are unevenly distributed is 20% or more of the total number of interface layers.

Further, the resin composition is a resin-coated metal container in which a rubber-like elastic resin is included in a part or all of the phase of the vinyl polymer.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

The polyester resin used in the present invention contains only a hydroxycarboxylic acid compound residue, a dicarboxylic acid residue and a diol compound residue, or a hydroxycarboxylic acid compound residue, a dicarboxylic acid residue and a diol compound. It is a thermoplastic polyester having a residue and a constituent unit, respectively. Also, a mixture of these may be used.

Examples of the hydroxycarboxylic acid compound as a raw material for the hydroxycarboxylic acid compound residue include p-hydroxybenzoic acid, p-hydroxyethylbenzoic acid and 2- (4-
(Hydroxyphenyl) -2- (4'-carboxyphenyl) propane and the like, these may be used alone, also,
You may mix and use 2 or more types.

Examples of dicarboxylic acid compounds forming a dicarboxylic acid residue include terephthalic acid, isophthalic acid, orthophthalic acid, 1,4-naphthalenedicarboxylic acid, 2,
Aromatic dicarboxylic acids such as 3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, diphenic acid, diphenyldicarboxylic acid, diphenoxyethanedicarboxylic acid and adipic acid, pimelic acid, sebacic acid, Azelaic acid, decanedicarboxylic acid, malonic acid, succinic acid, malic acid, aliphatic dicarboxylic acids such as citric acid, alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid and the like, these may be used alone, ,
You may mix and use 2 or more types.

Next, exemplifying a diol compound forming a diol residue, 2,2-bis (4-hydroxyphenyl) propane (hereinafter abbreviated as "bisphenol A"), bis
(4-hydroxyphenyl) methane, bis (2-hydroxyphenyl) methane, o-hydroxyphenyl-p-hydroxyphenylmethane, bis (4-hydroxyphenyl) ether,
Bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) ketone,
Bis (4-hydroxyphenyl) diphenylmethane, bis (4
-Hydroxyphenyl) -p-diisopropylbenzene, bis (3,5-dimethyl-4-hydroxyphenyl) methane, bis
(3-methyl-4-hydroxyphenyl) methane, bis (3,5-dimethyl-4-hydroxyphenyl) ether, bis (3,5-dimethyl-4-hydroxyphenyl) sulfone, bis (3,5-dimethyl- 4-hydroxyphenyl) sulfide, 1,1-bis (4
-Hydroxyphenyl) ethane, 1,1-bis (3,5-dimethyl-
4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 1,1-bis (4-
Hydroxyphenyl) -1-phenylethane, bis (4-hydroxyphenyl) phenylmethane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane 2,2-bis (3,5-dichloro-4-hydroxyphenyl) propane, 2,2-bis (3,5-dibromo-4)
-Hydroxyphenyl) propane, 2,2-bis (3-methyl-4-
Hydroxyphenyl) propane, 2,2-bis (3-chloro-4-
Hydroxyphenyl) propane, 2,2-bis (3-bromo-4-
Hydroxyphenyl) propane, 1,1,1,3,3,3-hexafluoro-2,2-bis (4-hydroxyphenyl) propane, 4,
Aromatic diols such as 4'-biphenol, 3,3 ', 5,5'-tetramethyl-4,4'-dihydroxybiphenyl, and 4,4'-dihydroxybenzophenone, and the aromatic ring moieties of these aromatic diols are partially Hydrogenated, ethylene glycol, trimethylene glycol, propylene glycol, tetramethylene glycol, 1,4-butanediol, pentamethylene glycol, neopentyl glycol, hexamethylene glycol, dodecamethylene glycol, diethylene glycol, triethylene Examples thereof include glycol, tetraethylene glycol, polyethylene glycol, aliphatic diols such as hydrogenated bisphenol A, and alicyclic diols such as cyclohexanedimethanol. These can be used alone or by mixing two or more kinds. It can also be used.

The polyester resins obtained from these may be used alone or in combination of two or more. The polyester resin used in the present invention may be composed of these compounds or a combination thereof, but among them, an aromatic polyester resin composed of an aromatic dicarboxylic acid residue and a diol residue, It is preferable from the standpoints of stability and thermal stability.

The polyester resin used in the present invention contains a small amount of a structural unit derived from a polyfunctional compound such as trimesic acid, pyromellitic acid, trimethylolethane, trimethylolpropane, trimethylolmethane, and pentaerythritol. The amount may be 2 mol% or less.

From the viewpoint of heat resistance and processability, the most preferable combination of these dicarboxylic acid compounds and diol compounds is 50 to 95 mol% of terephthalic acid, 50 to 5 mol% of isophthalic acid and / or orthophthalic acid. And a diol compound of a glycol having 2 to 5 carbon atoms.

Examples of preferred polyester resins used in the present invention include polyethylene terephthalate, polybutylene terephthalate, polyhexamethylene terephthalate, polycyclohexylene dimethylene terephthalate, polyethylene-2,6-naphthalate and polybutylene-2,
Examples thereof include 6-naphthalate, and among them, polyethylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate and polybutylene-2,6-naphthalate, which have appropriate mechanical properties, gas barrier properties and metal adhesion, are most preferable.

The polyester resin contained in the resin composition of the present invention may contain a metal compound such as germanium, antimony or titanium, which is a residue of a polyester production catalyst. The content of the metal compound in the polyester resin used in the resin composition of the present invention is not particularly limited, but the metal compound as the residue of the polymerization catalyst is preferably 50 ppm or less in order not to lose the flavor property.

The polyester resin used in the present invention is 25
The intrinsic viscosity measured at 0.5% concentration in o-chlorophenol at ℃ must be 0.3dl / g or more. If it is less than 0.3 dl / g, the polymer effect cannot be exhibited. The upper limit of the intrinsic viscosity is not specified, but the intrinsic viscosity is 2.0 dl / g.
If it exceeds, the moldability will be poor, and it is preferably 2.0 dl / g or less. More preferably, the intrinsic viscosity is 0.7 to 1.5 dl / g, and if the intrinsic viscosity is less than 0.7 dl / g, the material strength of the polyester resin itself is insufficient and cracks may occur under severe forming and processing conditions. If it exceeds 1.5 dl / g, the dispersibility of the added inorganic particles may deteriorate.

The polyester resin used in the present invention may be amorphous or crystalline, and when it is crystalline, the crystal melting temperature (Tm) is 100 ° C. or higher. preferable. If it is less than 100 ° C, it may be deformed by heat such as heat treatment. Furthermore, Tm is 210 ~ 265 ℃, preferably 210 ~ 245 ℃, low temperature crystallization temperature (Tc) is 11
It is desirable that the temperature is 0 to 220 ° C, preferably 120 to 215 ° C. If Tm exceeds 265 ° C or Tc exceeds 220 ° C, the vinyl polymer may decompose during kneading. If Tm is less than 210 ° C or Tc is less than 110 ° C, the heat resistance may be insufficient and the film shape may not be retained during processing. The glass transition temperature (Tg, sample amount about 10 mg, temperature rising rate 10 ° C / min measured by a differential thermal analyzer (DSC)) is preferably 50 to 120 ° C, more preferably 60 to 100 ° C. Further, when it is amorphous, it is desirable that the above Tg is 100 ° C. or higher. When it is amorphous and Tg is less than 100 ° C, the heat resistance is insufficient and cracks may occur during processing.

In the resin composition used in the present invention, the polar group
A vinyl polymer containing 1% by mass or more of a unit having
Mandatory to include. 1 unit with polar groups
A vinyl polymer containing at least mass% is a poling charge.
0.45 (eV) difference in negativeness^0.5A group in which the above elements are combined
A vinyl polymer containing 1% by mass or more of a unit having
is there. If the unit containing polar groups is less than 1% by mass,
Shotability may be reduced. Pauling electronegativity
The difference is 0.45 (eV)^0.5The group to which the above-mentioned elements are bonded is specifically
For example, -C-O-, -C = O, -COO-, epoxy group, C₂O₃,
C₂O₂N-, -CN, -NH ₂, -NH-, -X (X: F, Cl, Br), -SO₃-,
Etc. Also, neutralize with metal ions as polar groups
It may have an acid radical ion. In this case, metal
Na as an example of an ion⁺, K⁺, Li⁺, Zn²⁺, Mg²⁺, Ca²⁺,
Co²⁺, Ni²⁺, Pb²⁺, Cu²⁺, Mn²⁺, Ti ³⁺, Zr³⁺, Sc³⁺Etc.
Examples include monovalent, divalent or trivalent metal cations.

An example of a unit having a polar group is -C.
Vinyl alcohol as an example having a -O- group, vinyl chloromethyl ketone as an example having a -C = O group, acrylic acid, methacrylic acid, vinyl acetate as an example having a -COO- group,
Vinyl acids such as vinyl propionate and metal salts or ester derivatives thereof, glycidyl acrylate as an example having an epoxy group, glycidyl methacrylate, glycidyl ethacrylic acid, glycidyl itacrylic acid and the like, glycidyl ester of β-unsaturated acid, Maleic anhydride as an example having a C ₂ O ₃ group, an imide derivative of maleic anhydride as an example having a C ₂ O ₂ N- group, acrylonitrile as an example having a -CN group, and acrylamine as an example having a -NH ₂ group. , -N
Examples of acrylamide having an H- group, vinyl chloride as an example having a -X group, styrene sulfonic acid as an example having a -SO ₃ -group, and the like, and all or part of these acidic functional groups may be mentioned. The compounds neutralized with the above metal ions may be mentioned, and these may be contained alone or in plural in the vinyl polymer.

The vinyl polymer used in the present invention is a vinyl polymer containing 1% by mass or more of a unit having a polar group, and such a vinyl polymer is exemplified by the above-mentioned polar group-containing vinyl unit. Examples thereof include a single polymer or two or more polymers, and a copolymer of the polar group-containing vinyl unit and a nonpolar vinyl monomer represented by the following general formula (i). -CHR ¹ = CR ² R ^3- (i) (In the formula, R ¹ and R ³ are each independently an alkyl group having 1 to 12 carbon atoms or hydrogen, and R ² is an alkyl group having 1 to 12 carbon atoms. , A phenyl group or hydrogen.) When the nonpolar vinyl monomer represented by the general formula (i) is specifically shown,
Ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1
-In addition to α-olefins such as dodecene, aliphatic vinyl monomers such as isobutene and isobutylene, and styrene monomers
Aromatic vinyl such as alkylated styrenes such as o-, m-, p-methylstyrene, o-, m-, p-ethylstyrene and t-butylstyrene, and styrene monomer addition polymer units such as α-methylstyrene. Examples thereof include monomers.

Examples of homopolymers of polar group-containing units include polyvinyl alcohol, polymethyl methacrylate, polyvinyl acetate and the like. Examples of copolymers of polar group-containing units and non-polar vinyl monomers include ethylene-methacrylic acid copolymers, ethylene-acrylic acid copolymers, ethylene-vinyl acetate copolymers and copolymers thereof. Ionomer resin in which some or all of the acidic functional groups of the above are neutralized with metal ions, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-methacrylic acid Ethyl copolymer, ethylene-glycidyl methacrylate copolymer, ethylene-maleic anhydride copolymer, butene-ethylene-glycidyl methacrylate copolymer, styrene-methyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene- Maleic anhydride copolymer etc. and all or part of their acidic functional groups Ionomer resins neutralized with genus ions.

As the ionomer resin, known ionomer resins can be widely used. In particular,
It is a copolymer of a vinyl monomer and an α, β-unsaturated carboxylic acid in which some or all of the carboxylic acid in the copolymer is neutralized with a metal cation.

Illustrative vinyl monomers include the above α-
Olefin and styrene-based monomers and the like, α, β-unsaturated carboxylic acid is exemplified by α, β-unsaturated carboxylic acid having 3 to 8 carbon atoms, more specifically acrylic acid, methacrylic acid, maleic acid, Examples thereof include itaconic acid, maleic acid monomethyl ester, maleic anhydride, maleic acid monoethyl ester and the like.

An example of the neutralizing metal cation is N
a ⁺ , K ⁺ , Li ⁺ , Zn ²⁺ , Mg ²⁺ , Ca ²⁺ , Co ²⁺ , Ni ²⁺ , Pb ²⁺ , C
^Examples include monovalent, divalent or trivalent metal cations such as u ²⁺ , Mn ²⁺ , Ti ³⁺ , Zr ³⁺ and Sc ³⁺ . Further, a part of the remaining acidic functional group which is not neutralized with a metal cation may be esterified with a lower alcohol.

Specific examples of the ionomer resin include:
A copolymer of ethylene and an unsaturated monocarboxylic acid such as acrylic acid or methacrylic acid, or a copolymer of ethylene and an unsaturated dicarboxylic acid such as maleic acid or itaconic acid, wherein the carboxyl group in the copolymer is Examples of the resin include a resin in which a part or all of is neutralized with a metal ion such as sodium, potassium, lithium, zinc, magnesium and calcium.

Of these, the most preferable one is the one having a high impact resistance-improving ability and improving the compatibility between the polyester resin and the rubber-like elastic resin body described later, and the most preferable one is ethylene and acrylic acid or methacrylic acid. It is a resin (2 to 15 mol% of structural units having a carboxyl group) in which a polymer has 30 to 70% of the carboxyl groups neutralized with a metal cation such as Na or Zn.

Glass transition temperature (Tg, sample amount about 10 mg,
Temperature rise rate 10 ° C / min (measured with a differential thermal analyzer (DSC)) is 50
A vinyl polymer having a Young's modulus of 1000 MPa or less at room temperature or lower, and a breaking elongation of 50% or higher is preferable in order to further improve impact resistance.

Examples of preferred vinyl polymers used in the present invention include methacrylic acid, acrylic acid, polar olefins in which some or all of these acidic functional groups are neutralized with metal ions, methyl acrylate, acrylic acid. Examples thereof include ethyl, methyl methacrylate, ethyl methacrylate, glycidyl methacrylate, glycidyl acrylate, maleic anhydride, and vinyl acetate / α-olefin copolymers.

From the viewpoint of high impact resistance, ethylene-methacrylic acid copolymer, ethylene-acrylic acid copolymer, ethylene-vinyl acetate copolymer and acidic functional groups in these copolymers are more preferable. Ionomer resin in which some or all of the groups are neutralized with metal ions, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl methacrylate copolymer Copolymer, ethylene-glycidyl methacrylate copolymer, ethylene-glycidyl acrylate copolymer, ethylene-vinyl acetate-glycidyl methacrylate copolymer, ethylene-vinyl acetate-glycidyl acrylate copolymer, ethylene-carbon monoxide-glycidyl methacrylate copolymer Coalescence, ethylene-carbon monoxide-glycidyl acrylate copolymerization , Ethylene - anhydride Maren'i acid copolymer, butene - ethylene - glycidyl methacrylate copolymer, butene - ethylene - glycidyl acrylate copolymers.

From the viewpoint of ensuring barrier properties, a copolymer of α-olefin and a unit having a polar group is a preferred combination. The vinyl polymer used in the present invention may be any vinyl polymer containing 1% by mass or more of a unit having a polar group, and is not limited to the above specific examples.

The molecular weight of the vinyl polymer is not particularly limited, but a number average molecular weight of 2000 or more and 500000 or less is preferable. If it is less than 2000 or more than 500000, the impact resistance may decrease.

The dispersion shape and state of the vinyl polymer are not particularly limited, but preferably dispersed in the form of particles having an average particle size of 5 μm or less, more preferably in the form of particles having an average particle size of 1 μm or less. It is distributed. If it exceeds 5 μm, film processing may be difficult. Average particle size is
By dispersing the particles into particles of 1 μm or less, the impact property is increased, and the effect of relaxing the deformation stress under the heating environment is increased.

The amount of vinyl polymer is 20% by volume.
The following are preferred. If the volume ratio exceeds 20%, the basic properties such as heat resistance of the resin composition may change.

Furthermore, the resin composition used in the present invention must contain polar white inorganic particles in an amount of 10 to 50% by mass based on the total mass of the polyester resin and the vinyl polymer. The polar white inorganic particles are white inorganic particles having an element (I) -element (II) bond in the molecule and having a Pauling electronegativity difference of 0.45 (eV) ^0.5 or more. With respect to the total amount of the polyester resin and the vinyl polymer, if the content of this component is less than 10% by mass, the effect of enhancing the adhesive strength at the interface between the polyester resin phase and the vinyl polymer phase, and a sufficient hiding effect can be obtained. Absent. If it exceeds 50% by mass, the resin composition becomes brittle, and film formability and processability are deteriorated. By controlling the polarity within the above range, electrostatic interaction such as hydrogen bond, ionic interaction, or coordination interaction between the polar unit of the component and the polar unit of the polyester resin or the polar group between vinyl polymers, or sharing Bonding occurs. As a result, together with the improvement of the hiding effect due to the combined action of the white inorganic particles and the vinyl polymer, the adhesive force at the interface is strengthened, and it is possible to suppress the decrease in the mechanical strength of the resin composition due to the addition of the inorganic substance, and at the time of molding processing. Cracks and cracks are suppressed. In order to further strengthen these interactions, the difference in Pauling's electronegativity is preferably 1.0 (eV) ^0.5 or more. Incidentally, with respect to the white inorganic particles, if the mass ratio is up to 10%, hiding properties, whiteness, etc., without impairing the white inorganic particle addition effect, and if there is no problem in hygiene, other inorganic substances such as impurities May be mixed.

The white inorganic particles used in the present invention are poly
The difference in electronegativity of the ring is 0.45 (eV)^{0. Five}Has a certain polarity
The chemical structure is not particularly limited.
However, it has high concealing property and thermal stability, so
In contrast, particles that do not generate various toxic ions are preferred.
Freshly, metal oxides and metal carbonates, sulfates, nitric acid
Examples thereof include salts, phosphates, silicates and hydroxides. Concrete
As an example of white inorganic particles, titanium oxide (titanium oxide
White, rutile type, anatase type, etc., TiO₂), Zinc oxide
(Zinc white, ZnO), iron oxide (Fe₃O_Four), Silica (silica powder, Si
O₂), White carbon (SiO ₂・ NH₂O), diatomaceous earth (SiO₂・ NH
₂O), talc (talc powder, 3MgO ・ 4SiO)₂・ H₂O), Baliu Sulfate
BaSO_Four), Calcium sulfate (CaSO_Four), Barium carbonate (BaC
O₃), Calcium carbonate (CaCO₃), Gypsum (CaSO_Four・ 2H₂O), Ku
Ray (eg Al₂O₃・ 2SiO₂・ 2H₂O, etc.), Magnesium carbonate
(E.g. 3MgCO₃・ Mg (OH)₂・ 3H₂O ~ MgCO₃・ 3Mg (OH)₂
・ 11H₂O, etc.), alumina (Al (OH)₃) Etc.
Wear. These can be used alone or more than two types
It is also possible to use a mixture of the above.

Above all, it has a high concealing property and a high heat stability and is suitable for the human body.
And non-toxic within the prescribed amount range, Pauling's electronegative
The degree difference is 1.0 (eV)^0.5Having the above bonds, in vinyl polymer
Strongly interacts with the polar unit of
From the standpoint of suppressing cracks and cracks during molding
Preferred are metal oxides. Specifically the inorganic particles
For example, titanium oxide (titanium white, rutile type and
And anatase type, TiO ₂: 2.0 (eV)^0.5), Zinc oxide (zinc
Hana, ZnO: 1.9 (eV)^0.5), Iron oxide (Fe₃O_Four: 1.7 (eV)^0.5),
Rika (silica powder, SiO₂: 1.7 (eV)^0.5), Etc. During ~
However, titanium oxide, which has high hiding power and versatility, is especially preferred.
Good The titanium oxide species to be added is not particularly limited.
None, rutile type, anatase type, vulcarite type, etc.
However, rutile type is preferable from the viewpoint of concealment.
Yes.

The dispersion shape and state of these white inorganic particles are not particularly limited, but from the viewpoint of the hiding property, these particles are preferably dispersed in the composition in the form of particles having an average particle size of 0.1 to 1.0 μm. It is desirable that the particles are dispersed in the form of particles having an average particle size of 0.2 to 0.5 μm. When the average particle size is 0.1 μm or less, the dispersibility in the polyester resin phase is reduced. On the other hand, if the average particle size exceeds 1.0 μm, the obtained film surface may have a rough feeling, and the appearance may be impaired. From the viewpoint of enhancing the interfacial strength between the polyester resin phase and the vinyl polymer phase, these components are preferably localized at the interface. Specifically, of the number of inorganic particles (X1), 20% or more of the particles by number are unevenly distributed at the interface between the polyester resin phase and the vinyl polymer phase, or between the polyester resin and the vinyl polymer. It is preferable that the white inorganic particles are dispersed so that the white inorganic particles are present in 20% or more of the number of interfaces (X2). More preferably, 50% or more of X1 is present at the interface, or 50% of X2.
The above is a dispersed state in which one or more particles are present. Such a dispersed state is unevenly distributed from a microscopic viewpoint, but since the vinyl polymer phase is finely dispersed in the polyester resin phase, the macroscopic viewpoint results in dispersibility of the white inorganic particles. And improves the light scattering intensity together with the vinyl polymer phase, resulting in a high hiding effect. Further, from the viewpoint of the hiding property of the polyester resin phase, it is preferable that the white inorganic particles are also dispersed in the polyester resin phase, and particularly 10% or more of X1 is preferably dispersed in the polyester resin phase.

These dispersed states can be observed by distinguishing the polyester resin phase, the vinyl polymer phase and the white inorganic particles by a known method. The following method can be illustrated as a specific method. If necessary, the polyester resin phase and the white inorganic particle phase can be distinguished from each other by dyeing contrast, and then the vinyl polymer phase is etched with a solvent that dissolves only the vinyl polymer, and observed with an electron microscope. The uneven distribution of white inorganic particles on the etched surface (interface between the polyester resin phase and the vinyl polymer phase) can be quantified by using an image processing method or the like. Specifically, the identified white inorganic particles are randomly extracted, and the number ratio of the white inorganic particles present at the interface between the polyester resin phase and the vinyl polymer phase or the interface between the polyester resin phase and the vinyl polymer phase is selected. The layers are similarly extracted, and the uneven distribution state can be quantitatively evaluated by the number ratio of the interface layer in which the white inorganic particles are present. The number of white inorganic particles or the interface layer to be unevenly distributed determination target is not particularly limited, but it is preferable to evaluate the total number in the observation field of view (5 cm × 5 cm) enlarged about 5000 times, from the statistical significance,
It is desirable to perform the same evaluation for 10 or more visual fields, more preferably for 20 or more visual fields.

Further, a part of the vinyl polymer, preferably all the phases, contains a rubber-like elastic material,
It is desirable from the viewpoint of increasing the impact resistance of the resin composition and the effect of relaxing the deformation stress during molding. A wide variety of known rubber-like elastic body resins can be used for the rubber-like elastic body. Among them, the glass transition temperature of the developing part (Tg, sample amount about 10 mg, heating rate 1
A rubber-like elastic resin having a temperature of 0 ° C./min (measured by a differential thermal analyzer (DSC)) of 50 ° C. or less, a Young's modulus of 1000 MPa or less at room temperature, and a breaking elongation of 50% or more is preferable. Rubber elasticity
If the Tg is more than 50 ° C, the Young's modulus at room temperature is more than 1000 MPa, and the elongation at break is less than 50%, the impact resistance and the deformation stress relaxing effect at the time of molding cannot be sufficiently exhibited. Further, from the viewpoint of further enhancing these effects, Tg is preferably 10 ° C. or lower, more preferably −30 ° C. or lower. Further, the Young's modulus at room temperature is 100 MPa or less, more preferably 10 MPa or less, the elongation at break is 100% or more, more preferably 30 MPa.
It is preferably 0% or more.

Specific examples of the rubber-like elastic body include solid rubber, latex, thermoplastic elastomer, liquid rubber, and powdered rubber described in "Rubber Elastomer Utilization Handbook" by Shinzo Yamashita, published by Industrial Research Society (1985). And so on. Among them, the most preferable from the film processability are solid rubber and thermoplastic elastomer, and the most preferable from the viewpoint of the barrier property against metal corrosion factors,
It is a polyolefin-based rubber-like elastic body. Specific examples of the preferred polyolefin-based rubber-like elastic material, ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-1-pentene copolymer, ethylene-3-ethylpentene copolymer, A copolymer of ethylene and an α-olefin having 3 or more carbon atoms such as an ethylene-1-octene copolymer, or butadiene, isoprene, or 5 in the binary copolymer.
-Methylidene-2-norbornene, 5-ethylidene-2-norbornene, cyclopentadiene, 1,4-hexadiene, etc. are copolymerized with ethylene, α-olefins having 3 or more carbon atoms and non-conjugated dienes. is there. Among them,
Binary copolymer of ethylene-propylene copolymer or ethylene-1-butene copolymer, or ethylene-propylene copolymer or ethylene-1-butene copolymer with 5-methylidene-2 as non-conjugated diene -Norbornene, 5-ethylidene-2-
A resin obtained by copolymerizing norbornene, cyclopentadiene, and 1,4-hexadiene with an amount of α-olefin of 20 to 60 mol% and a non-conjugated diene of 0.5 to 10 mol% is most preferable in terms of film processability.

A specific example of the method of encapsulating the rubber-like elastic material in the vinyl polymer phase is to control the proportion of polar units in the vinyl polymer within the range of 1% by mass or more according to the chemical structure of the rubber-like elastic material. However, it can be achieved by controlling the interfacial tension between the three, that is, the wettability so that the vinyl polymer phase exists at the interface between the rubber-like elastic body phase and the polyester resin phase.

In the resin composition used in the present invention, the dispersed state in which the rubber-like elastic material is included in the vinyl polymer phase means an area ratio of 80% or more, preferably 9% or more of the interface of the rubber-like elastic resin phase.
It is a structure in which 5% or more is covered with a vinyl polymer and the direct contact area between the polyester resin and the rubber-like elastic body is less than 20%. With such a structure, it becomes easy to finely disperse the rubber-like elastic body encapsulated with the vinyl polymer, and the impact resistance and film-forming property are improved. Further, the rubber-like elastic body generally has low adhesion to the metal plate, but since the vinyl polymer having a polar group has the adhesion to the metal plate, even if the finely dispersed rubber-like elastic body comes into contact with the metal plate. It has the effect of ensuring the adhesion between the resin composition and the metal plate. The inclusion state is
The rubber-like elastic material and the vinyl polymer can be distinguished by a known dyeing method or the like and observed by an electron microscope or the like.

The addition amount of the rubber-like elastic material is not particularly limited, but the preferable addition amount is such that the content of the vinyl polymer and the rubber-like elastic material is 50% by mass or less with respect to the polyester resin. 50
If the content exceeds 100% by mass, the hardness may decrease.

The resin composition used in the present invention has other purposes such as rigidity, linear expansion characteristics, lubricity, surface hardness, heat stability, light stability, oxidation stability, mold release, dyeing, and antistatic property. For the purpose of antibacterial, antifungal, etc., an appropriate amount of known physical property modifiers that are non-toxic to the human body may be added. Among them, as the antioxidant, a radical inhibitor is particularly preferable, and it is preferable to add one or more selected from a phenol radical inhibitor, a sulfide radical inhibitor, and a nitrogen radical inhibitor.

To mix the resin composition used in the present invention,
A wide variety of known resin mixing methods such as a resin kneading method and a solvent mixing method can be used. Examples of the resin kneading method include dry blending with a tumbler blender, a Henschel mixer, a V-type blender, etc., and then a single-screw or twin-screw extruder,
A method of melt-kneading with a kneader, Banbury mixer or the like can be used. Moreover, when the solvent mixing method is exemplified, after dissolving each resin in a common solvent of the raw material resins contained in the resin composition, the solvent is evaporated, or a method of recovering the precipitated mixture by adding it to a common poor solvent, etc. There is.

In the case of kneading by melt mixing, prepare a masterbatch in which any one or a plurality of resins are preliminarily mixed with white inorganic particles, and use these masterbatches in part or in whole. They may be melt mixed. Alternatively, on the contrary, after melt-mixing only the resin component in advance, the inorganic particles may be added and melt-mixed. From the viewpoint of the hiding property, it is preferable that the white inorganic particles are also dispersed in the polyester resin phase, and the melt mixing using a masterbatch in which the white inorganic particles are premixed with the polyester resin in a high concentration is more preferable.

The resin composition used in the present invention may be used directly or / and may be processed into a film. When processed into a film, at least the resin composition may be molded alone, or a resin film formed by laminating it in combination with another resin or resin composition and / or an adhesive may be used. In the case of single molding, known manufacturing methods can be widely applied. Specific examples thereof include a solvent casting method, a thermal compression method, a calendering method, a T-die casting method, a T-die uniaxial or biaxial stretching method, and an inflation method, but are not particularly limited thereto. Also, in the case of laminating a film made of another resin or a resin composition on the film which has been molded alone, for the purpose of flavoring property and prevention of outflow of eluate, a known laminating method can be used. Specifically, a method of laminating at the time of molding by the multi-layer T-die method, a method of laminating to a single molded film by thermocompression bonding or an adhesive, and the like can be mentioned. In the case of laminating via thermocompression bonding or an adhesive to a single-molded film, in order to increase the surface tension of the single-molded film to enhance adhesion, a known film treatment such as corona discharge treatment or plasma treatment is performed. It doesn't matter.

As the adhesive, a polyester resin-based water-based dispersant disclosed in JP-B-60-12233 is used.
Epoxy adhesive disclosed in JP 63-13829 A, JP
A wide variety of known adhesives such as polymers having various functional groups disclosed in JP-A-61-149341 can be used. It is preferable to select an adhesive effective for the main component resin depending on the layer to be bonded and the main component of the resin composition layer used in the present invention. Further, a publicly known organic substance layer or inorganic substance layer which is non-toxic to the human body may be laminated on the upper and lower layers of the film used in the present invention for the purpose of imparting surface hardness and designing property.

Further, in order to improve printability, known film treatment such as corona discharge treatment or plasma treatment may be performed.

The metal plate used in the present invention is a metal plate having a surface coated with a film obtained by directly and / or processing the resin composition. The metal plate is not particularly limited, but tin plate, thin tin plated steel plate, electrolytic chromic acid treated steel plate (tin-free steel), steel plate for containers such as nickel plated steel plates, and metal plates used for metal containers such as aluminum Can be mentioned. The metal plate may be coated on either one side or both sides. The coating film thickness of the metal plate coated with the resin composition used in the present invention is not particularly limited, but is preferably 1 to 300 μm. If it is less than 1 μm, the impact resistance of the coating may not be sufficient, and if it exceeds 300 μm, the economy is poor.

A known method can be used for coating the metal plate. Specifically, (1) a method in which the resin composition prepared by melt-kneading the raw material resin in advance with a kneader is formed into a film by an extruder with a T-die, and thermocompression-bonded to a metal plate (in this case, The film may be unstretched or may be stretched in one direction or in two directions), and (2) a method of directly thermocompressing the film discharged from the T die. Another option for direct thermocompression bonding of the film is (3) T
Instead of the resin composition in the hopper of an extruder with a die,
Adding the resin and the inorganic particles as the raw material of the resin composition,
A method in which the resin composition is kneaded in an extruder and directly thermocompression-bonded thereto is used. Furthermore, the resin composition used in the present invention can exhibit sufficient impact resistance even if the crystallinity is not graded inside the coated film. Therefore, (4) a method of melting the resin composition and coating with a bar coater or a roll,
(5) a method of immersing a metal plate in a molten resin composition, (6) a method of dissolving the resin composition in a solvent and spin coating, (7)
It is also possible to coat the metal plate with an adhesive or the like, and the coating method is not particularly limited.

The most preferable method for coating the metal plate is the above methods (1), (2) and (3) from the viewpoint of work efficiency.
When coating is performed using the method (2), the film thickness is preferably 1 to 300 μm for the same reason as above. Further, the surface roughness of the film is preferably 500 nm or less in R _max as a result of arbitrarily measuring the film surface roughness by a length of 1 mm. If R _max exceeds 500 nm, air bubbles may be entrapped during coating by thermocompression bonding. Further, due to the high impact resistance of the resin composition, the resin composition exhibits high impact resistance even if it is used without stretching. Therefore, it can be used as a metal coating material for containers without stretching, and the number of steps can be reduced. Further, when used as a metal coating material for a container without stretching, it is not necessary to control the crystallinity in the thin film by controlling the temperature, plate passing speed, etc., so that the process window can be expanded and high-speed manufacturing can be performed. Become. Further, since it is easy to control the molding temperature for controlling the crystallinity during film formation and coating, it is possible to manufacture a container product with stable performance.

Further, when a metal plate is coated with a film obtained by directly and / or processing the above resin composition, at least one of the above resin composition or the above film is coated on one side and / or both sides of the metal plate. It is essential to use and coat in a single layer or in multiple layers. At this time, one or two or more kinds of resin or film may be used to form a single layer or a multilayer on one side and / or both sides of the metal plate, and if necessary, polyethylene terephthalate, Polyester resin such as polycarbonate and the film, and polyolefin resin such as polyethylene and the film, polyamide resin such as 6-nylon and the film, ionomer resin and other known resin such as the film and the film,
Alternatively, a crystalline / amorphous polyester resin composition and the film, a polyester / ionomer resin composition and the film, a known resin composition such as the polyester / polycarbonate resin composition and the film, and the film, its lower layer and / or It may be laminated on the upper layer and covered. As a specific stacking method,
(1), when using the method of (2) and (3), to produce a multilayer film of a resin film and another resin film or resin composition film used in the present invention using a multilayer T die, There is a method of thermocompression bonding this. Further, when using the above method (4) ~ (6), or coating the resin composition used in the present invention after coating another resin composition, or conversely the resin composition used in the present invention It is possible to laminate in multiple layers by coating the resin with another resin composition.

The resin-coated metal plate used in the present invention is a metal plate coated with a film obtained by directly and / or processing the resin composition, and the coating may be on one side or on both sides. good. The thickness of the metal plate is not particularly limited, but is preferably 0.01 to 5 mm. If it is less than 0.01 mm, strength is difficult to develop, and if it exceeds 5 mm, processing is difficult.

The resin-coated metal container of the present invention is a metal container made of the resin-coated metal plate and can be molded by a known processing method. Specific examples thereof include draw ironing molding and stretch draw molding, but any resin-coated metal container using the resin-coated metal plate may be used, and the molding method is not limited to the exemplified molding method. The molded container is provided with a printing layer on the outer surface by a known method to obtain a product.

The resin-coated metal container of the present invention has an intrinsic viscosity of 0.
3dl / g or more polyester resin and a mixture containing a vinyl polymer containing 1% by mass or more of a unit having a polar group, a resin composition in which polar inorganic particles are added in an amount of 10 to 50% by mass, directly and / or It is a resin-coated metal container obtained by processing a film, coating the metal plate, and then forming and processing the metal plate.

The resin composition used contains polar white inorganic particles having a Pauling electronegativity difference of 0.45 (eV) ^0.5 or more. Therefore, the white inorganic particle component and the carbonyl group of the polyester resin or A covalent bond or an electrostatic interaction can be exerted between polar units such as a terminal functional group and polar units of a vinyl polymer. Therefore, it is possible to enhance the adhesive force at the interface between the polyester resin phase and the vinyl copolymer phase, enhance the light scattering effect, and exhibit a high hiding property. Furthermore, this effect can be remarkably exhibited by specifying the polarity and dispersion state of the inorganic particles, the intrinsic viscosity of the polyester resin, and by adding the rubber-like elastic material in a specific dispersion state and adding it.

As a result, the resin composition used has a high level of contradictory properties such as hiding and molding processability due to the addition of white inorganic particles. Furthermore, polyester resin, impact resistance, chemical resistance, moldability, heat resistance, gas barrier property of corrosion-causing substances, and water resistance originally possessed by a resin composition composed of a vinyl polymer containing 1% by mass or more of a unit having a polar group. Properties and adhesion to metal are not impaired. Further, the metal plate coated with the resin composition to be used, good molding processability, the resin-coated metal container of the present invention capable of having characteristics such as corrosion resistance, the resin composition, directly and / or in a film. A metal container obtained by processing at least one side of a metal plate after processing, and then processing the metal plate, which has impact resistance, chemical resistance, moldability, heat resistance, and gas barrier properties of corrosion-causing substances. It has excellent water resistance and adhesion to metal, and in particular, it has excellent concealing properties and molding processability, which are problems in the prior art, and various and beautiful designs such as printing can be applied. Therefore, it is possible to provide a cosmetic metal container which has excellent appearance and beauty, is extremely beautiful, and has a high food protection effect, and can be suitably used as a container for soft drinks and foods.

[0062]

EXAMPLES Next, the present invention will be described in more detail based on Examples and Comparative Examples, but the present invention is not limited to the following Examples without departing from the gist thereof.

In the following Examples and Comparative Examples, polyethylene terephthalate (PET) [SA-1346P, MA-1344 manufactured by Unitika Ltd.] as a polyester resin, polybutylene terephthalate (PBT) [Jura manufactured by Polyplastics Co., Ltd.] NEX 2001], ethylene-glycidyl methacrylate copolymer as a vinyl polymer having 1% by mass or more of a unit having a polar group [Sumitomo Chemical Co., Ltd. Bond First 2C],
Ethylene-alkyl acrylate-glycidyl methacrylate copolymer [Bond First 7L manufactured by Sumitomo Chemical Co., Ltd.], ethylene-based ionomer [Himilan 1 manufactured by Mitsui DuPont Co., Ltd.]
706], ethylene-propylene rubber as a rubber-like elastic body (EP
R) [EP07P made by JSR Corporation], ethylene-butene rubber (EBM) [JSR
EBM2041P] manufactured by Co., Ltd. was used. When melt-kneading, a phenolic antioxidant [Adeka Stub A manufactured by Asahi Denka Co., Ltd.
O-60] was used.

(Examples 1 to 10) Each resin and each type of inorganic particles were dry blended at the respective composition ratios shown in Table 1 using a V-type blender. The phenolic antioxidant AO-60 is
In each case, 0.1 part by mass was added to 100 parts by mass of the resin composition. This mixture was melt-kneaded at 260 ° C. with a twin-screw extruder to obtain resin composition pellets containing various white inorganic particles. The difference in electronegativity of each inorganic particle poling is titanium dioxide: 2.0 (eV) ^0.5 , barium sulfate: 2.6 (eV).
^0.5 , silica: 1.7 (eV) ^0.5 , alumina: 2.0 (eV) ^0.5 , the average particle size of each added inorganic particles, titanium dioxide: 0.4 μm, barium sulfate: 0.8 μm, silica: 0.5 μm,
Alumina: 0.6 μm.

An ultrathin section was cut from the resin composition with a microtome, stained with ruthenic acid, and the dispersion state of the vinyl polymer and the rubber-like elastic material in the polyester resin was analyzed by a transmission electron microscope. As a result, the vinyl polymers of Examples 1 to 4 had an equivalent spherical equivalent diameter of 1 μm or less and were finely dispersed in the polyester resin, and all of the rubber-like elastic resin of Examples 5 to 10 were vinyl. Almost 100% encapsulated with polymer, the equivalent spherical equivalent diameter of rubber-like elastic resin is
It was finely dispersed in the polyester resin at 1 μm or less. Further, in all cases, 20% or more of the number of various inorganic particles added was unevenly distributed at the interface between the polyester resin and the vinyl polymer.

[0066]

[Table 1]

Using the pellets, 1 in an extrusion T-die
A film having a thickness of 5 μm was obtained (extrusion temperature: 280 ° C.). The hiding property of this film was evaluated by the following evaluation method. In addition, this film was laminated on one side of 2.5 m thick tin-free steel heated to 250 ° C and cooled by water to 10
It was rapidly cooled to below 100 ° C within seconds. The room temperature resin-coated metal plate thus obtained was evaluated for each item of adhesion, molding processability, retort resistance, room temperature impact resistance and low temperature impact resistance by the evaluation methods shown below. .

<Hiding property> The white film (thickness: 15 μm)
About, using a Macbeth transmission densitometer TD932, with a transmission nozzle diameter of 3 mm, based on the amount of incident light and transmitted light,
The transmitted light density was measured to evaluate the shielding property. Evaluation is ◎:
0.5 or more, ◯: 0.45 to 0.5, Δ: 0.4 to 0.45, and ×: 0.4 or less. Table 2 shows the concealment results.

<Adhesion> The above white film-coated metal plate was cross-cut (5 cm
X 5 cm) and immersed in an aqueous solution of 1.5% by mass citric acid-1.5% by mass sodium chloride (UCC solution) at room temperature for 24 hours, and then evaluated by the peeled width (mm) of the film (average of 10 samples). Evaluation,
◎: 0.0 mm, ○: 0.0 to 0.5 mm, △: 0.5 to 2.0 mm, and ×: 2.
It was over 0 mm. The results of the adhesion test are shown in Table 2.

<Formability> The above-mentioned white film-coated metal plate was processed at a handling rate of 70%, and the molding processability was evaluated by the soundness of the film after processing and the adhesion to a steel plate. Evaluation is: ◎: film peeling 0.0 mm, ○: film peeling 1
Less than mm, Δ: less than 2 mm of film peeling, and ×: film was damaged during processing. Table 2 shows the results of the processing followability test.

<Retort resistance> The above-mentioned white film-coated metal plate was subjected to a retort treatment (in the presence of steam, under pressure, at 130 ° C.,
30 minutes), the peeling situation of the film, appearance change (unevenness, shrinkage,
The peeling) was visually confirmed. The evaluation is ◎: no abnormality, ○:
Slight change, Δ: surface changed considerably, and ×: base was exposed. Table 2 shows the results of the retort resistance test.

<Normal Temperature Impact Resistance and Low Temperature Impact Resistance> The impact resistance of the present white film-coated metal sheet was evaluated by a DuPont drop impact test. After dropping a 0.5 kg iron ball from a height of 30 cm on a metal plate, the convex side of the sample (r = 8 m
With the metal plate as the bottom so that (m) is the top, a wall is formed with a soft rubber-like resin around the convex part, and 1.
ERV when + 6V voltage is applied by using 0% saline solution as sample, platinum as cathode and cathode as cathode.
The value (mA) was measured. The ERV value was evaluated by the following index. After placing the resin-coated metal plate in a constant temperature bath at 0 ° C. for 24 hours, the same impact resistance evaluation was performed to evaluate the impact resistance at low temperature. Evaluation is: ◎: All samples are less than 0.01mA, ○:
.About.3 samples were 0.01 mA or more, .DELTA.: 3 to 6 samples were 0.01 mA or more, and x: 7 samples or more were 0.01 mA or more. The results are shown in Table 2.

[0073]

[Table 2]

(Comparative Examples 1 to 5) In the same manner as in Examples 1 to 10, the resin compositions were dry blended in the respective composition ratios shown in Table 3 using a V-type blender. In each case, 0.1 part by mass of the phenolic antioxidant AO-60 was added to 100 parts by mass of the resin composition. This mixture is mixed in a twin-screw extruder
The mixture was melt-kneaded at 260 ° C. to obtain resin composition pellets containing titanium dioxide as inorganic particles.

Ultrathin sections were cut from the resin composition with a microtome, stained with ruthenic acid, and the dispersion state of the vinyl polymer and the rubber-like elastic resin in the polyester resin was analyzed by a transmission electron microscope. As a result, Comparative Examples 1 and 2
The vinyl polymer of the equivalent spherical equivalent diameter is 1 μm or less and is finely dispersed in the polyester resin, and the rubber-like elastic resin of Comparative Examples 3 to 5 are all 100% encapsulated with the vinyl polymer. The equivalent spherical equivalent diameter of the rubber-like elastic resin is
It was finely dispersed in the polyester resin at 1 μm or less.

[0076]

[Table 3]

In the same manner as in Examples 1 to 10, it was attempted to obtain a film having a thickness of 15 μm by extrusion using the present pellets (extrusion temperature: 280 ° C.), but in Comparative Examples 2 and 4, white inorganic particles were used. Since more than 50% by mass was added, stable film formation could not be performed. Only the films of Comparative Examples 1, 3 and 5 for which stable film formation was possible were evaluated for the hiding property by the evaluation method shown in Examples 1 to 10. In addition, only for the film that could be stably formed as described above, it was attached to one side of 2.5 mm thick tin-free steel heated to 250 ° C, and water-cooled within 10 seconds.
It was rapidly cooled to below 100 ° C. With respect to the resin coated metal plate at room temperature thus obtained, by the same evaluation method as in Examples 1 to 10, adhesion, forming processability, retort resistance, room temperature impact resistance and low temperature impact resistance Was evaluated. The results are shown in Table 4.

[0078]

[Table 4]

As is clear from the results of Examples 1 to 10 and Comparative Examples 1 to 5, a vinyl polymer containing 1% by mass or more of a unit having a polyester resin and a polar group, or a polyester resin having a polar group A film composed of a resin composition obtained by adding a specific amount of polar white inorganic particles to a mixture composed of a vinyl polymer containing 1% by mass or more of a unit and a rubber-like elastic material is originally the resin composition. It had a high concealing property while maintaining various physical properties. In particular, it was found that addition of inorganic particles for securing the hiding property, which was a problem in general films, did not cause deterioration in adhesion, forming processability, and the like.

(Examples 11 and 12 and Comparative Examples 6 and 7) Polyethylene terephthalate (PET) [SA-1346P, MA-1344 manufactured by Unitika Ltd.] as polyester resin, and titanium dioxide (average particle size 0.2 to A masterbatch polyethylene terephthalate containing 50% of 0.3 μm) was prepared in advance. Each polyethylene terephthalate, the corresponding master batch containing 50% of each titanium dioxide, high milan 1706 as a vinyl polymer having 1% by mass or more of a unit having a polar group, ethylene-butene rubber (EBM) as a rubber-like elastic body, Each composition ratio shown in 5 was dry blended using a V-type blender. The phenolic antioxidant AO-60 was used as the resin composition 1 in both cases.
0.1 parts by mass was added to 00 parts by mass. 2 this mixture
Two resin composition pellets containing titanium dioxide particles (final concentration 20%) were obtained by melt-kneading at 260 ° C. with a shaft extruder.

As a comparative example, as shown in Table 5, polyethylene terephthalate was used as the polyester resin.
(PET) [Unitika Ltd. SA-1346P, MA-1344], and using only masterbatch polyethylene terephthalate containing 50% titanium dioxide (average particle size 0.2 to 0.3 μm) in each, Examples 11, 12 Contains titanium dioxide particles as well as
Two types of resin composition pellets (final concentration 20%) were obtained.

[0082]

[Table 5]

Ultrathin sections were cut from the two resin compositions shown in Examples 11 and 12 with a microtome and then stained with ruthenic acid to indicate the vinyl polymer in the polyester resin and the dispersed state of the rubber-like elastic resin. Was analyzed by a transmission electron microscope. As a result, similarly to Examples 1 to 10, the rubber-like elastic resin is almost 100% encapsulated with a vinyl polymer, and the equivalent spherical equivalent diameter of the rubber-like elastic resin is 1 μm or less in the polyester resin. It was finely dispersed. Further, in all cases, 20% or more of the number of various inorganic particles added was unevenly distributed at the interface between the polyester resin and the vinyl polymer.

Pellets from Examples 11 and 12 and Comparative Examples 6 and 7
15μm with an extrusion T-die using each of the pellets
A thick white film was obtained (extrusion temperature: 280 ° C.). The hiding power of this film was evaluated by the evaluation methods shown in Examples 1 to 10. In addition, this film was laminated on both sides of 2.5 mm thick tin-free steel heated to 250 ° C, and rapidly cooled to 100 ° C or less within 10 seconds by water cooling. The resin-coated metal plate at room temperature thus obtained was cut into a disc shape with a diameter of 150 mm, deep-drawn in four steps using a drawing die and punch, and a side seamless container with a diameter of 55 mm (hereinafter abbreviated as container) 10) were prepared.

The following observations and tests were carried out on these containers, and the results evaluated according to the following criteria are shown in Table 6.

<Deep Drawing Workability> The appearance changes (peeling, breakage, etc.) of the film on the outer and inner surfaces of the container after deep drawing workability were visually confirmed. The evaluation was made as follows: ○: no abnormality was found in all 10 pieces, Δ: change was found in 1 to 5 pieces, ×: change was found in 6 pieces or more.

<Retort resistance> The above resin-coated metal plate was subjected to retort treatment by a conventional method, and the appearance change (unevenness, shrinkage, peeling, etc.) of the film on the outer and inner surfaces of the container was visually confirmed. The evaluation was ○: no abnormality was found in all 10 pieces,
Δ: Change is recognized for 1 to 5 pieces, and x: Change is recognized for 6 or more pieces.

<Impact resistance> Distilled water was fully poured into a container after deep drawing workability, and 10 pieces of each sample were dropped from a height of 10 cm onto a PVC tile floor surface, and then the ERV test in the container was performed. went. The evaluation was made as follows: ○: 0.1 mA or less for all 10 pieces, Δ: more than 0.1 mA for 1 to 5 pieces, ×: more than 0.1 mA for 6 or more pieces.

[0089]

[Table 6]

From Examples 11 and 12 and Comparative Examples 6 and 7, when the same titanium oxide was used and the concentration was the same, the white film used in the present invention showed higher concealing property and was completely used in the container forming process. There was no problem. Furthermore, the container of the present invention had retort resistance and impact resistance. Further, Example 11,
The letter "ABCDEFG" of the alphabet is printed on the 12 containers by the gravure printing method using the colored ink that is mainly used as the urethane resin, and after printing, it is dried at 80 ° C for 1 minute. As a result, characters and bleeding on the coated film were not recognized.

As is clear from Examples 1 to 12 and Comparative Examples 1 to 7, obtained by adding a predetermined amount of white inorganic particles having a predetermined polarity to a polyester resin, a vinyl polymer and a rubber-like elastic body. The metal container coated with the resin composition is a resin composition originally composed of a polyester resin and a vinyl polymer, which has excellent processability, impact resistance, and excellent physical properties such as adhesion with a metal, without deteriorating, High concealment,
It was found to have printability.

[0092]

EFFECTS OF THE INVENTION Since the resin-coated metal container of the present invention has the polar white inorganic particles in a specific dispersion state, the white inorganic particle component and a polar unit such as a carbonyl group or a terminal functional group of the polyester resin can be used. Since the polar unit of the vinyl polymer exerts a covalent bond or an electrostatic interaction between the polar units, it enhances the adhesive force at the interface between the polyester resin phase and the vinyl copolymer phase and has a high hiding effect.

Furthermore, the impact resistance, chemical resistance, moldability, heat resistance, gas barrier properties of corrosion-causing substances, water resistance, and the like, which are inherent in polyester resins and vinyl polymers containing 1% by mass or more of a unit having a polar group, It does not impair the adhesion to metal.

Therefore, the resin-coated metal container of the present invention is excellent in impact resistance, chemical resistance, moldability, heat resistance, gas barrier property of corrosion-causing substances, water resistance and adhesion to metal, and in particular, concealment It has excellent properties and molding processability, and it is possible to give a variety of beautiful designs. Therefore, it is possible to provide a cosmetic metal container which has excellent appearance and beauty, is extremely beautiful, and has a high food protection effect, and can be suitably used as a container for soft drinks and foods.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B65D 65/40 B65D 65/40 D C08K 3/00 C08K 3/00 C08L 57/00 C08L 57/00 67 / 00 67/00 (72) Inventor Hiroshi Jodai 20-1 Shintomi, Futtsu City, Chiba Prefecture Nippon Steel Co., Ltd.Technology Development Division (72) Inventor Issei Niki 20-1 Shintomi Shintomi, Futtsu City, Chiba Prefecture Company Technology Development Headquarters (72) Inventor Akihiro Kikuchi 20-1 Shintomi Steel, Futtsu City, Chiba Prefecture Nippon Steel Co., Ltd. (72) Inventor Yoshihiro Nami 20-1 Shintomi, Futtsu City, Chiba Prefecture Nippon Steel Stock Company F-Term in Technology Development Headquarters (reference) 3E086 AB01 BA04 BA13 BA15 BB01 BB41 BB74 CA01 CA11 4F100 AA21B AB01A AB03A AK41B AK42B AK65B AK70B AL05B AN02B BA02 BA07 DA01 GB16 GB32 JA06B JJ03 JK10 JL01 JL10 JN02 YY00B 4J002 BE02X BE05X BF02X BG01X BG04X BG10X BG12X BH02X CF03W CF04W CF05W CF06W CF07W CF08W CF14W CF18W DE106 DE116 DE136 DE236 DG046 DG056 DJ016

Claims (2)

[Claims] 1. A polar white inorganic particle is added in an amount of 10 to 50% by mass to a mixture containing a polyester resin having an intrinsic viscosity of 0.3 dl / g or more and a vinyl polymer containing 1% by mass or more of a unit having a polar group. A resin composition comprising the above, directly and / or after being processed into a film, after coating on at least one surface of a metal plate, a resin-coated metal container formed by molding the metal plate, wherein the polyester resin and the The number of the inorganic particles unevenly distributed at the interface of the vinyl polymer is 20 of all the inorganic particles.
%, And / or the number of interface layers of the polyester resin and the vinyl polymer having the inorganic particles unevenly distributed is 20% or more of the total number of interface layers, and a resin-coated metal container. 2. The resin-coated metal container according to claim 1, wherein the resin composition contains a rubber-like elastic resin in a part or all of the phase of the vinyl polymer.