JPS5978277A - Adhesive primer for metal container - Google Patents

Abstract

PURPOSE:To provide the titled primer excellent in adhesion to copolyester adhesives and metallic substrates, by incorporating vinyl chloride resins as the dispersion phase and two particular resins as the continuous phase. CONSTITUTION:10-80wt% vinyl chloride resin particles (A) with the degree of polymn. of 800-4,000 and particle size of 0.01-10mu, 10-80wt% solvent-soluble vinyl chloride/vinyl acetate copolymer (B) with the degree of polymn. of 80- 1,500, containing 5-500mmol/100g of carboxyl and/or hydroxyl groups, and 2- 30wt% solvent-soluble thermosetting resin (C) having reactivity with carboxyl and/or hydroxyl groups (e.g., epoxy or butyral resin) are incorporated; namely, said components B and C are dissolved in solvents (e.g., xylene, methyl ethyl ketone, or butanol), and component A is dispersed in the resulting resin soln. to yield a coating (primer).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an adhesive primer for metal containers,
More specifically, a bottle-shaped metal container is manufactured by bonding a lower body and an upper body, each of which is made of a metal cup-shaped molded body, at their circumferential ends with a hot melt adhesive. Regarding the adhesive primer used. In particular, the present invention
The present invention relates to a J'J2 primer that has excellent adhesion or adhesion to copolyester adhesives and metal substrates, and is also excellent in processability into cups and corrosion resistance at seams.

An upper body and a lower body, each made of a cup-shaped molded body formed by drawing or drawing-ironing a metal material, are lapped (overlapping) and joined at the circumferential open end, and the circumferential side seam is The formed bottle-shaped metal containers have many advantages over so-called can-shaped metal containers.

Among conventional packaging metal containers, those called three-piece cans have end caps double-sealed at the top and bottom of the end sides with side seams to form a sealed part, and those called two-piece cans In this case, a sealed portion is formed by forming a metal material by drawing or drawing and ironing and then performing heavy seaming.

However, such a double-sealed metal container is subject to major limitations in terms of pressure resistance of the sealed portion and in terms of saving the metal material. That is, in a joint formed by double seaming, the material forming the joint deforms first due to the load applied to the joint, and this deformation causes leakage or breakage of the joint with a relatively small load. In order to prevent this, the material itself must be considerably thicker. In addition, in packaging containers, it is always required to make the metal material used thinner, both from the standpoint of economy and from the standpoint of reducing container softening. There is a problem that buckling is likely to occur due to the load applied in the axial direction of the container during the double seaming process or the preparatory process such as flange processing.

A bottle-shaped metal container formed by lap-joining an upper body and a lower body, each of which is a cup-shaped molded body, at their open ends, can be constructed by lap-joining an upper body and a lower body, each of which is a cup-shaped molded body, even if the material forming the seam is extremely thin. It does not cause any deformation and can withstand up to the shear strength of the seam, which is unrelated to the thickness of the material, and since there is no need for a tightening process, it has the advantage that the side wall of the container can be made thinner without the fear of buckling. have.

However, when forming a circumferential side seam by lap-joining the lower body and the upper) 11S body at their circumferential opening ψ1111, the adhesive primer interposed between the adhesive layer and the metal material The most severe conditions will be required.

In other words, in the case of a straight lap joint on the end side, both ends of this joint can be secured (like a long wall) by seaming with the end cap, but in the case of the circumferential 111 direction seam described above, the entire circumference is fixed. Since there is no root-like fixation throughout the joint, dimensional deformation of the joint itself easily occurs, or shear stress is likely to be generated in the joint.Furthermore, stress is likely to be generated in the joint because the diameter of the open end tends to change due to temperature changes. I, which forms a seam in history; iJ
The free end portion is often thinned, and the joint tends to be easily deformed by external force.

Even if the metal material and thermal plastic adhesive present at this joint can absorb or withstand such stress, the v:coating primer that is present between the metal material and the adhesive Adhesion or adhesion tends to decrease significantly due to stress.

Moreover, since the lower body and upper body are formed by advanced drawing processing or drawing-iron processing, the coating film that serves as an adhesive primer and protective layer can withstand these forming processes, and has a high resistance to TT''r; It must be highly edible.

According to the present invention, on a solid content basis, (A) vinyl chloride resin particles with a degree of polymerization of 800 to 4,000, 10 to 80% by weight;
Solvent-soluble vinyl chloride-vinyl acetate-carboxyl group- or hydroxyl group-containing vinyl unit copolymer 10 containing a concentration of 500 mmol/100 jq jJj combination
to 80% by weight and (C) solvent-soluble thermosetting resin 2 having reactivity with carboxy groups and/or hydroxyl groups
The copolymer (B) and the thermosetting resin (C) are in a continuous phase as a dispersion medium, and the vinyl chloride resin particles (A) are in the continuous phase. An adhesive primer for metal containers is provided, characterized in that it is present in the form of a dispersion of JJ.

The invention will be explained in detail below.

ml to 6 showing an example of a bottle-shaped metal container, this container is made up of a lower body 1 made of a seamless cup-shaped molded body made of coated metal, and a seamless cup-shaped molded body made of coated metal. These cup-like shapes are formed by the open end 6 and the open end 4 being brought together (, ) 8 to form a periphery. (H,lI +f+
By forming the 1A1'ij eye 5, it is integrated into the shape of the container.

In this specific example, the lower body 1 is a cup consisting of a side wall portion 6 and a bottom portion 7 formed by drawing a painted metal material 14, and the upper body 2 also has a side wall portion formed by pattern forming of a painted metal material. 8 and upper J+ii 9. The side wall 6 of the lower body 10 and the side wall 8 of the two-part body 2 have approximately the same diameter. The upper wall 9 of the upper body 2 has an upwardly convex tapered surface, and a spout 10 for filling or taking out the contents is formed in the center of the upper wall 9 of the upper body 2. It will be clear that the upper body 2 is joined onto the lower body in the form of a so-called bottle [4] and half of the body.

In the specific example shown in FIG. 1, the open end 6 of the lower body 1 is narrowed to a smaller diameter than the rest of the body wall by neck-in processing in the vicinity of the open end 6. It is fitted into the open end 4 of the large diameter upper body. As shown in an enlarged view in Fig. 6, the painted metal material constituting the lower body and the upper body consists of a metal substrate 11 such as surface-treated aluminum and an adhesion primer and retention layer applied to the surface of the metal substrate 11, and the coating film is 12
α, 1215. An adhesive layer 16 is provided between the outer surface of the lower body open end 6 and the inner surface of the upper body open end 4 to join and fix the lower body and the upper body. A portion of the adhesive 16 protrudes from the seam 5, and the coating layer 1 is applied to the cut edge 14 of the metal material located inside the seam.
The formation of 5 means that the resistance is 1f'! Desirable in terms of eating habits.

In the present invention, the coating films 12α and 12b have the following composition, that is, based on the solid content, (/f) ffi degree is 800 to 4.
000 vinyl chloride resin particles 10 to 80 heavy weights, (
JJ) 5 to 500 carboxyl groups and/or hydroxyl groups
10 to 80% by weight of a solvent-soluble vinyl chloride-vinyl acetate-carboxyl group- or hydroxyl group-containing vinyl unit copolymer containing at a concentration of 1 J mole/100 g polymer and (C) carboxyl group and/or hydroxyl group. This method is characterized in that it uses a coating material made of a composition containing 2 to 60 parts of a solvent-soluble thermosetting resin that is reactive with respect to other materials.

The vinyl chloride resin coating film with the specific composition mentioned above is metal-based! The adhesion with the paint film is sufficiently improved not only under normal contact conditions, but also after filling with corrosive contents or even after heat sterilization, and the processability of the coating film is improved. It offers significant advantages in terms of corrosion resistance as a protective coating. As will be detailed later, this composition provides a coating film with excellent adhesion to the metal substrate, mechanical properties, and workability, and the metal material with this coating film can be subjected to high-place drawing processing, such as drawing and re-drawing. Even when subjected to drawing processing, etc., coating defects such as splinters, cracks, wrinkles, etc. do not occur. Furthermore, vinyl chloride resin has excellent water resistance even though it has relatively strong polarity, and also exhibits excellent barrier properties against gold JJ4 corrosive components contained in the contents of the container.

In the paint of the present invention, the vinyl chloride resin particles (A) act to increase the amount or concentration of vinyl chloride units in the paint film, thereby increasing the barrier properties of the paint film against corrosive components. In addition, vinyl chloride resin particles CA) improve the processability of the paint film by 5IJ compared to paints that do not contain these particles.
This makes it possible to draw or deep draw a painted metal plate without causing the above-mentioned coating film defects. Furthermore, these vinyl chloride resin particles improve coating properties,
This provides the advantage of allowing thick coating on metal materials.

Furthermore, the vinyl chloride resin particles (A) increase the amount or concentration of vinyl chloride units in the coating film, thereby increasing the adhesiveness with the copolyester adhesive.

This utilizes the phenomenon that a vinyl chloride resin coating and a copolyester adhesive form a strong adhesive bond when heated. That is, the inventors'? According to IF research, when a copolyester adhesive is heat-sealed to a vinyl chloride resin coating, the two resins mix extremely well at the bonding interface between the two, which enables strong adhesion. This is thought to be the cause. Despite the completely different chemical structures of these two resins, the good mixing of both resins under hot rilIli deposition conditions is related to the fact that the solubility indices of both resins are quite close. It is recognized that

Solubility Parayne 473
tttr, , Sp value) means, for example, J, B, l? A
NIJRUP et al.” polytner l1ctnt
``Chapter 4 (Kunn Wiley & 5
oorLs, Inc., Published, 1967) 1:u
8;944 energy density (c
It is defined as the fifth power of al/+r-). This solubility index is closely related to the strength of hydrogen bonding in thermoplastic resins, and polar groups such as hydroxyl groups, amide groups, ester groups, nitrile groups, or chlorine atoms are attached to the main chain or side chain of the polymer. The thermoplastic polymer contained therein generally exhibits a high solubility index of 9 or more, which is related to the content and distribution state of these polar groups.

The mA table below shows the SP values of polyvinyl chloride, polyethylene terephthalate-1-, and polybutylene terephthalate.

Polyvinyl chloride 9.56 Polyethylene terephthalate 10.7 Polybutylene terephthalate 98 The solubility index (SP value) of the copolymer is approximated as the arithmetic average value from the S-α of the homopolymer of each monomer constituting the copolymer. You can also ask for it. For example, the Sr1 direct value of polybutylene/ethylene terephthalate is calculated using the following formula % formula % (1) where BSp is the polybutylene ethylene terephthalate O5P value,
- It is the mole fraction of units, and can be approximately determined by E5p being S□・1 of polyethylene terephthalate, and n being the mole fraction of ethylene terephthalate units in the copolyester. The same φ is also true for copolymer type vinyl chloride resins. Furthermore, the same applies to polymer blends.

This vinyl chloride type (vj fat particles (・4) is 10 to 80
Part (j) Particularly 20 to 60 go I (-h) 3 in amount of candy
It is also important to have this seal '2jjl',j
1llj: If the number of blades is less than the river, the above-mentioned advantages are not achieved, while "2+il": When 1'4>more than 4, the adhesion to the metal substrate 1, the processing of the coating is poor. In addition, the degree of polymerization of the vinyl chloride resin particles (A) is from 800 to 4.
000, especially 9. It is also safe to have a molecular weight in the range of 0 to 3,0 (J O) from the viewpoint of processability, and if this molecular weight is outside the above range, the processability and mechanical properties of the coating will deteriorate.

The vinyl chloride-based resin particles (t4) to be used are obtained by emulsion polymerization of vinyl chloride alone or a combination of vinyl chloride and other vinyl-11'Lit substances, such as comonomers such as furidiene, styrene, and vinyl acetate. It is also produced by suspension polymerization, and its particle size is generally 0.01 to 10
microns, especially in the range 0.02 to 5 microns.

Next, the solvent-soluble vinyl chloride-vinyl acetate-carboxyl group- or hydroxyl group-containing vinyl unit copolymer (B) contained in the paint of the present invention contains polar groups such as carboxyl groups and water isthmus groups. In connection with this, it acts to significantly improve the tightness with the metal substrate, and in connection with the inclusion of vinyl chloride units, it also seems to assist in thermal adhesion with the copolyester adhesive. It acts on In addition, this copolymer (B) provides excellent processability to the coating film due to the fact that it contains vinyl acetate units, and also provides plastic properties to the entire coating film. Furthermore, this solvent-soluble copolymer (/Q is
In the form of a paint, it stabilizes the dispersion of the vinyl chloride resin particles G/4), while in the form of a baked coating film, it acts to integrate and homogenize each component.

This solvent-soluble copolymer (B) also has a solid content of 1
0 to 80% by weight, it is also necessary to be present in an amount of 10 to 60% by weight in Samurai; when this amount is less than the above range, the advantages mentioned above will not be achieved; When the amount is more than 1, mechanical properties such as processability and creep resistance of the coating film are deteriorated.

This solvent-soluble copolymer (B) has carboxyl co- and/or hydroxyl groups of 5 to 500 μIJ mole/1oog resin, particularly preferably 10 to 300 μIJ mole/100
It is also important to contain it at a concentration of 5 m mot7100 g resin, and if this concentration is lower than 5 m mot7100 g resin,
Peeling occurs between the metal substrate and the coating film (for JT, on the other hand, the degree of S is 500 mmot71o).

If it is higher than g resin, the water resistance of the coating film will decrease and the pressure resistance and corrosion resistance will also be lost.

The vinyl chloride units in copolymer CB> are 5 per copolymer.
0 to 95% by weight and 2 to 40 vinyl acetate units
Preferably, it is present in an amount of t% by weight. This copolymer (
B) generally has a degree of polymerization of 80 to 1,500, and desirably has a molecular weight smaller than that of the vinyl chloride resin particles (B).

Suitable examples of ethylenically unsaturated monomers that provide carboxyl groups are acrylic acid, methacrylic acid, fumaric acid, maleic anhydride, crotonic acid, itaconic acid, citraconic acid, tetrahydrophthalic anhydride, etc., which provide hydroxyl groups. Suitable examples of monomers are vinyl alcohol (ie saponified vinyl acetate), hydroxyethyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, and the like.

Suitable examples of vinyl chloride resins include partially saponified vinyl chloride-vinyl acetate copolymers, vinyl chloride-vinyl acetate-acrylic acid copolymers, partially saponified and partially butyralized vinyl chloride-vinyl acetate copolymers, Vinyl chloride-vinyl acetate-methacrylic acid copolymer, vinyl chloride-vinyl acetate-
Maleic anhydride copolymer, vinyl chloride-vinyl acetate-hydroxyethyl acrylate copolymer, vinyl chloride-vinyl acetate-hydroxyethyl methacrylate copolymer,
Vinyl chloride-vinyl acetate-acrylic acid copolymer 'fl-
saponified products etc.

Furthermore, since the solvent-soluble thermosetting resin (C) contained in the paint of the present invention has reactivity with carboxyl groups and hydroxyl groups, it imparts curability to the formed paint film. , and density with metal group % j>: performs an auxiliary action to further improve the hardness.

In addition, by using a -[boxy group-containing resin as the -component of this thermosetting resin (C), the thermal stability of the vinyl chloride resin particles (A) and the vinyl chloride copolymer (B) can be significantly improved. Improve. Conventionally, as a heat stabilizer for vinyl chloride resin, one with 41π is known,
These heat stabilizers tend to build up on painted surfaces and at interfaces with metal materials, impair adhesion and adhesion, and migrate into the contents, impairing hygienic properties. On the other hand, by using thermosetting resins containing epoxy groups, these resins are bonded to other resins and thermally stabilized in a reticulated state, so the above-mentioned drawbacks are effectively eliminated. .

Furthermore, by using, for example, a phenol formaldehyde resin as a component of the thermosetting resin CC), a strong adhesive bond with the polyamide adhesive can be obtained.

The thermosetting 11'1 resin (C) includes epoxy resin, resol type and/or novolac type phenol/formaldehyde rγ1 resin, urea-formaldehyde resin, melamine/formaldehyde resin, alkyd resin,
polyester resin, acrylic resin, polyurethane resin,
One or a combination of two or more of xylene resin, epoxy ester resin, petitral iris 1 resin, etc. can be used.

A preferred epoxy resin is an epoxy resin derived from bisphenol A and ehihalohydrin, and has a molecular weight of 650 to 4,000. In particular, it is 300 to 1,500, and the epoxy equivalent is 180 to 3,50G.

In particular, it is between 200 and 1500. Epoxy resin and phenol resin or amine 4ij4 fat at 0.5:
A weight ratio of 5 to 20:80 is suitable for the purposes of the present invention. These thermosetting 40・■ fats can be further transformed with drying oil, semi-drying oil, rosin, rosin ester, etc.
It can also be used as

In addition, the thermosetting resin (C) is added in a range of 2 to 6 per solid content of the paint.
It is also important to use a 0 ton moon attack, especially 5 to 20 j'1 (145%), and if it is less than the above range, satisfactory results may be obtained in terms of curing properties, adhesion, and thermal stability. On the other hand, if the amount exceeds the above range, the excellent advantages of a vinyl chloride paint will be lost.

In the coating material of the present invention, the above-mentioned copolymer (B) and a thermosetting one. The resin (C) is used as a liquid medium, and the vinyl chloride resin particles (4f) are present in the continuous phase in the form of a liquid. Because of this characteristic, this paint can be applied with a high solid content concentration, and can also be applied thickly (TJ capability).

The paint of the present invention contains the component (j) and component (C),
Aromatic hydrocarbon rr media such as toluene and xylene; acetone, methyl ethyl ketone, methyl isobutyl ketone,
Dissolved in one or more of the following: ketone solvents such as cyclohexanone; alcohol solvents such as ethanol, gropanol, butanol; cellosolve solvents such as ethylseronulp and butyl cellosolve; and ester solvents such as ethyl acetate and butyl acetate. and add vinyl chloride resin C to this solution.
It is manufactured by dispersing A).

This paint has a solid content concentration in the range of 10 to 70% by weight and a viscosity suitable for coating, and is used for coating on metal materials.

Coating can be performed by any means such as roller coating, brush coating, doctor coater, spray coating, electrostatic coating, and dip coating. The amount of coating on the metal material is 0.0 on a dry basis.
A range of 5 to 60 g/m", particularly 1 to 2097 m2, is convenient for the purpose of the present invention. The metal material after coating is heated to 150 g/m2 in a hot air oven, an infrared heating furnace, etc.
The desired coating film is obtained by baking at 650° C. for 5 seconds to 60 minutes.

The baked coating film that is formed is a generally homogeneous, integrated, and dense coating film. It is desirable that this coating film has a glass transition temperature (TI) of 40°C or higher, particularly 60°C or higher. In this regard, the vinyl chloride resin coating film U1 of the present invention does not contain any plasticizer, or even if it contains it, it contains it in a relatively small amount that does not lower the glass transition temperature below 40°C. Should. Furthermore, since vinyl acetate units incorporated into vinyl chloride resins also tend to lower the glass transition temperature, the vinyl acetate units should be incorporated within a range where the glass transition temperature is within the above range.

This vinyl chloride resin is blended with a compounding agent known per se. For example, plasticizers such as dioctyl phthalate and epoxidized soybean oil can be used within the above limits, as well as heat stabilizers such as calcium stearate, zinc stearate, organotin compounds, organophosphate esters, microcrystalline wax, and higher fatty acids. A lubricant such as amide, a filler such as calcium carbonate or fired ray, or a pigment such as titanium oxide, zinc oxide or aluminum powder may be blended in a known formulation.

The metal materials that make up the seamless cup include untreated steel plates (black plates), various surface-treated steel plates, such as tin-plated steel plates (tin plate), galvanized steel plates, aluminized steel plates, nickel-plated steel plates, and chrome-plated steel plates. Electrolytically treated steel sheets such as electrolytic chromic acid treated steel sheets;
Chemically treated steel plates such as phosphoric acid and/or chromic acid treated steel plates, light metal plates such as aluminum, or composites thereof are used.

In order to obtain a seamless cup, the above-mentioned painted metal material is punched into a shape such as a disk, subjected to one-stage or multi-stage drawing processing between a drawing punch and a drawing die, and if desired, the drawing cup is ironed and punched. It is subjected to multi-stage ironing processing between the ironing die and the ironing die. The operations and conditions for these drawing and ironing processes are known per se, and can be performed under conditions known per se.

The thickness of the raw material for painting after processing varies depending on the final dimensions of the container and the type of material, but generally it is 0.1 to 0.5 mrrt, 0.2 to 0.35 ++ for 4'>.
The thickness of the side wall is preferably in the range of 0.05 to 0.20 m when ironing is performed.
It is best to set it to 0.06 to 0.17++m for m and l.

In the present invention, it is preferable to produce a cup-shaped molded body by drawing or drawing and re-drawing (deep drawing) a painted metal material.
Of course, it is also possible to produce a cup-shaped molded body by ironing, and then coat this cup-shaped molded body with the vinyl chloride resin paint.

The thermoplastic resin used for bonding the upper body and the lower body is selected from heat-sealable resins so as to satisfy the above-mentioned 17 requirements. Suitable examples include, but are not limited to, polynisglu, polyamide,
It mainly consists of ionomers (ionically crosslinked olefin copolymers), acid-modified polyolefins, vinyl ester copolymers, copolycarbonates, etc. Among these materials, those that satisfy the various requirements mentioned above are used. be done.

For example, in the case of polynisdel, 50 moles or more of terephthalic acid component as an acid component in the main chain as a copolyester,
Diol component and 1,4-butanediol component 50
Adhesives based on copolyesters having a molar coefficient or higher are advantageously used, and those consisting of copolyesters alone, blends of copolyesters, or blends of copolyesters and other thermoplastic resins are used.

Acid components other than terephthalic acid include isophthalic acid, knack dicarboxylic acid, diphenyl dicarboxylic acid, diphenylmethane dicarboxylic acid, adipic acid, cepatic acid,
Examples of diol components other than 1,4-butanediol include maleic acid, fumaric acid, succinic acid, hexyhytrothyrentalic acid, and dl, ethylene glycol, propylene glycol, neopentyl glycol , diethylene glycol, triethylene glycol,
Examples include cyclohexanediol and xylene glycol.

The copolyester should have a sufficiently high molecular weight from the point of view of mechanical properties, and it is generally desirable to have a number average molecular weight of 6,000 or more, particularly 9,000 to 500,000. . Furthermore, from the viewpoint of the creep resistance mentioned above, it is preferable that the copolyester has a crystallinity of 6 to 45 inches and 5 to 40 qb as measured by the density method. Furthermore, from the viewpoint of thermal bonding workability, the copolyester with
It is desirable to have a melting point of 0°C.

The above-mentioned copolyesters can be used alone or in a blend of two or more, and can also be used with other thermoplastic resins, such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-butene-1 copolymer, ionic crosslinking. It can also be used in the form of a blend of olefin resins such as olefin copolymers (ionomers), ethylene-vinyl acetate copolymers, ethylene-acrylic acid copolymers, acid-modified polyethylene, and acid-modified polypropylene. Of course, these olefinic resins are used in an amount not exceeding 50% by weight of the entire adhesive, particularly in an amount of less than 60% by weight.

In the case of polyamide, examples of suitable polyamide adhesives include those having 4 to 12 amide groups per 100 carbon atoms.
(Both are one type of nylon, more specifically, poly-ω-aminodecanoic acid, poly-ω-aminoundecanoic acid, poly-ω-aminododecanoic acid, poly-ω-aminotridecanoic acid, Decanoic acid, polydecamethylene dodecamide, polydecamethylene dodecamide, polydecamethylene tridecamide, polydodecamethylene adipamide, polydecamethylene tricamide, polydodecamethylene dodecamide,
Polydodecamethylene tridecamide, polytridecamethylene adipamide, polytridecamethylene adipamide, polytridecamethylene dodecamide, polytridecamethylene tridecamide, polyhexamethylene azelamide, polytridecamethylene azelamide, Polydobyl methylene azeramide,
Examples include boritridecamethylene azelamide.

Even if these polyamides are a blend of 27 layers or more,
Alternatively, it can be used in the form of a copolyamide consisting of a combination of each monomer, or in the form of a combinatorial blend of these.

The polyamide used may be modified with a different component such as dameric acid if it is small in size.

Ionomers include resins obtained by neutralizing copolymers of olefins and unsaturated carboxylic acids or other vinyl monomers with alkali metals, alkaline earth metals, or organic bases. Surlyn j, c4 commercially available from .

Furthermore, polyolefin polymers such as polyethylene, polyzolopylene, and crystalline ethylene-propylene copolymers may be added with acrylic acid, methacrylic acid, etc.
A tS-modified polyolefin obtained by graft polymerization with an ethylenically unsaturated carboxylic acid such as itaconic anhydride may be used. Furthermore, as a vinyl ester copolymer, a copolymer of a vinyl ester and an olefin or other vinyl monomer, or a partially saponified product thereof, such as ethylene/acetic acid fJ cupinyl co↓11. Coalescence, partial saponification of ethylene-vinyl acetate copolymer, and vinyl chloride/vinyl acetate copolymer are used to obtain 1-.

These resins may be mixed with well-known compounding agents,
For example, fillers, ultraviolet absorbers, stabilizers, lubricants, antioxidants, pigments, dyes, antistatic agents, etc. can be added according to known formulations.

In the present invention, the adhesive is applied to the open end edges of the cups to be joined prior to fitting the cups together. This adhesive layer is preferably applied so that the thickness of the resin layer is 10 to 2 Ll O μm, especially 20 to 150 μm (and the width of the overlapping joint, that is, the inside of the wrap is 1 to 30 mm).
It is particularly preferable to apply it in 2 to 20 increments.

The adhesive resin can be applied to the desired part of the cup in various forms, for example in the form of a film, powder, slurry, solution, plastisol or emulsion; in particular, the adhesive can be easily handled and applied. It is also an advantage that it can be applied in the form of a film that is easy to handle and can be easily manipulated such as drying.

Adhesive application can be applied to laminates,
Application methods such as extrusion, electrostatic powder coating, fixed coating, spray coating, nozzle discharge, dip coating, roll coating, and brushing can be used.

Since the above paint is applied to the parts of the metal materials to be joined, this paint is used as a primer for the adhesive.
IJ L, desired adhesion is obtained.

When overlapping and joining the circumferential open ends of the cups,
The cut edge of the metal material is inevitably exposed inside the seam. The cut edges may be wrapped with adhesive tape or coated with adhesive powder, slurry, or
A solution can also be applied to the cut edge to protect it.

The adhesive can be applied to the outside or inside surface of the open edge of the cup on the inside or outside of the seam, or can be applied to both sides.

The other cup is fitted onto the cup coated with adhesive, and then the adhesive present in the overlapping portion is melted, and if necessary, the joint is cooled to form a joint.

Heating of the overlapping part can be done by high frequency induction heating, infrared heating, hot air heating, heat transfer heating from a heating element, etc., and cooling of the joint can be done by any operation such as air cooling, air cooling, water cooling, etc. .

At this time, it is important to melt the adhesive while the adhesive layer is pressed and clamped between the open end on the outside of the seam and the open end on the inside of the seam to ensure airtightness and adhesive strength. Generally speaking, of both open ends forming a circumferential overlapping joint, the outer diameter of the inner end is DI, and the inner diameter of the outer end is DI. When the thickness of the adhesive layer interposed between the two is dA, these dimensions are selected so that the following inequality % formula % holds true, and the thickness of the adhesive after bonding is 10 to 150 μm, especially 1° to 150 μm. 100μ
It is desirable to set it to m.

The metal container described above is particularly useful as a container for contents having autogenous pressure such as carbonated drinks, beer, and low-malt beer, and as an internal pressure container for filling nitrogen gas, liquid nitrogen, etc. together with the contents.

Of course, the brimer of the present invention can be applied not only to the above-mentioned metal container having a circumferential side surface, but also to a straight side seam.
] It can be advantageously used for the main end of metal containers etc. .

The invention is illustrated by the following example.

[F, I, 9 Jlu of paint] The paints used in the following examples contained the following components (1) to (5) in the proportions shown in Table 1, so that the nonvolatile content was 40% by weight. It is dissolved and/or dispersed in a solvent.

(1) Vinyl chloride resin: An electromagnetic induction stirrer and a pressure gauge were used.5 [) Oml stainless steel autoclave bottle with 300 ml of distilled water, 0.6 g of sodium dodecylbenzenesulfonate, and potassium persulfate and iog added. After closing the lid, the autoclave was cooled to -20°C in a dry ice-methanol bath, and after purging with nitrogen, liquid J'+iA vinyl mono-7
- Prepare ioo and y. The temperature is then raised to 53° C. and polymerization is carried out with stirring. After reacting for 8 hours, return to room temperature,
Remove residual monomers and then purge the interior with nitrogen. The resulting emulsion is diluted to 15 ml with water, and 5 ml of saline solution is added while stirring to precipitate polyvinyl chloride.

The precipitated polymer is washed with water, suctioned, and dried.

The degree of polymerization was 125o.

In the same manner, a vinyl chloride resin having a polymerization degree of 730.664° and 426° was synthesized.

(2) Vinyl chloride copolymer resin: In an autoclave, 6υo7111 of water in which 0.6y of polyvinyl alcohol with a hydrolysis rate of 80% was dissolved, azobisisobityronitrile o, 1sy, and 10g of vinyl acetate 7111 were added. In addition, dry ice-methanol bath cP
Cool to -20°C. Next, add 90 g of liquid vinyl chloride salt. The temperature and pressure were increased to 58°C, and polymerization was carried out for 6 hours while stirring.

The obtained polymer had a degree of polymerization of 625 and a composition of vinyl chloride/vinyl acetate=91/9 (wt%) (this is designated as Vi).

Similarly, polymerization degree 290, vinyl chloride/vinyl acetate =
75/25 (M amount 9g) (V-2), and degree of polymerization 615
, vinyl chloride/vinyl acetate = 71/29 (wt%)
The vinyl chloride-vinyl acetate copolymer (V-3) was completely synthesized.

Also, polymerization degree 305, vinyl chloride/vinyl acetate/maleic anhydride = 91/8.810.2 (wt%) CV-4
), and degree of polymerization 290, vinyl chloride/vinyl acetate/maleic anhydride = 90/9.510.5 (wt%) CV-
5) and a six-element copolymer of vinyl chloride/vinyl acetate/maleic anhydride-86/11/6 (wt%) (V-6) with a polymerization degree of 295 were also synthesized in the same manner.

In addition, the vinyl chloride-vinyl acetate copolymer V-1, V
-2, by partially saponifying V-3 with alkali,
A vinyl chloride-vinyl acetate-vinyl alcohol copolymer was obtained. Each has a polymerization degree of 325j! Vinyl dichloride/69 vinyl/vinyl alcohol=91/6/6 (weight)
(V-7); Degree of polymerization 290. Vinyl chloride/vinyl acetate/
Vinyl alcohol-75/6/19 (wt%) (V-
8); Polymerization degree: 615 - composition of vinyl chloride/vinyl acetate/vinyl alcohol = 7175/24 (% by weight) (F-9).

(3) Epoxy resin: EPOrL828 (product of Shell Chemical Co., Ltd., trade name, bisphenol A type epoxy resin, average molecular weight 680, epoxy resin -184 to 194) (4) Amino resin: Beckamine p-1+8 (product of Dainippon Ink Co., Ltd.) , butyl etherified urea resin) (5) Phenol resin: Dissolve 0.5 mole of carbolic acid and 0.5 mole of p-cresol in 1.5 mole of 67 formaldehyde aqueous solution, add catalyst, add 0.15 mole of ammonia, and add 95 mole of ammonia. The reaction was carried out at ℃ for 6 hours. The reaction product is extracted with a mixed solvent consisting of ketones, alcohols, hydrocarbons, etc., washed with water, the aqueous layer is removed, a small amount of remaining water is removed using an azeotropic method, and the product is cooled to produce a resol type phenolic resin. A 60-chi solution was obtained.

Furthermore, in the following examples, metal containers were evaluated according to the method described below.

[Evaluation of metal containers]

(b) Measurement of joint shear strength After joining, the metal container is filled with water for 70 minutes.
After waiting for 10 hours at ℃, specimens were cut out including joints of 7 cIrL in the height direction and 2 cIrL in the circumferential direction, and were pulled at a tensile speed of 100 using Tensilon.
A shear fracture test was conducted at room temperature,
It was expressed as shear strength taking into account the adhesive area of the lap joint. Measurements were made for each of six containers, and the arithmetic mean value was taken as the measured value. fr, oh, here 54~
57 kl? The value written as /cwt' or more indicates that the plate has broken, and the actual strength t is greater than this value.

(b) Measurement of joint peel strength After joining, the metal container is filled with water and then heated for 70 minutes.
After waiting for 10 hours at ℃, each joint was cut out in a circumferential shape, and a T-peel fracture test was performed using Tensilon at a tensile speed of 200 mm/min at room temperature.The width of the lap joint was determined. After taking this into consideration, the average peel strength was determined for each of the six containers, and the major types of failure were classified into 1.
．． Classification between paint film and board, ■, paint film-adhesive, L adhesive, 1v, and paint film 1-1 Visual observation as shown in the above table.

(c) Denting test After filling each metal container with the specified contents, a weight (, 4) weighing 4 kg is placed at a constant height C as shown in Figure 4.
A metal container tilted at an angle of 22.5° to the horizontal direction from 6mm) CB) 0.5 from the edge of the outer body of the joint
Let it naturally fall vertically to the myn position.

In this test, if the top and bottom bodies separated or a gap occurred at the joint, the net was broken, and after being left at 26℃ for 48 hours, the internal pressure was measured and found to have decreased by more than 5 inches compared to immediately after filling. leakage was considered to be the case where oozing of the contents near the joint was observed. In the table, the sum of the leaks and broken nets is shown as the leakage rate (@), and the broken net rate ((6)) is shown in parentheses.

Incidentally, 0° C. and 25° C. were selected as the test conditions, and after confirming that the entire test specimen had sufficiently reached that temperature, 50 tests were conducted for each.

2) Drop test After filling each metal container with the specified contents, test the chamber 11. 25 wires were dropped from a height of 90 CIn in two directions: (1) with the bottom facing downwards and (11) with the joints facing downwards. I checked to see if it existed. The table shows −C for each case.
1 The sum of the above leakage and network breakage is shown as the leakage rate (part), and the figure in parentheses is the network breakage rate (@ indicates buko).

(e) 50"C 6 months aging test container fJ!t change)) Complete volume of the container before caulking and filling (After filling the contents into a measured container and aging, there was no leakage at all.) Measure the total volume again and calculate the difference as the volume change △V
And so. Ten pieces of each were measured, and their arithmetic mean value was used as the result.

・Leakage and mesh breakage rate A broken mesh is defined as a case where the top and bottom bodies are separated, or one of the tits is deformed and there is a gap at the joint.

In addition, cases in which the internal pressure at 25° C. decreased by 5% or more compared to immediately after filling, and cases in which some content was observed to ooze out near the joint were considered to be leaks. Sometimes, the total number of leaks and broken networks out of 50 is calculated as the leak rate ((6)
The percentage of net breakage (chi) is shown in parentheses.

・Metal Elution After filling a synthetic carbonated beverage into a metal container and allowing it to stand at a specified temperature and time, measure the amount of eluted metals using atomic absorption spectroscopy 1-
is. Ten pieces of each were measured, and the 3f average value was used as the result.

<Examples 1 to 10, Comparative Examples 1 to 5> Paints having the compositions shown in Table 1 were applied to the inner and outer surfaces of aluminum plates (3004 material R19 chromate treated) with a material thickness of 0.26 to a total coating amount. 120my/dm2,'5Q
After coating and baking to give a diameter of m9/dm2, it was punched out into a disc with a diameter of 250 mm and formed by normal press working, with an inner diameter of 110.6 mm at the edge of the joint and a diameter of 0 mm in the center. An upper body with a spout was made.

On the other hand, a disk with a diameter of 250 mm was punched out from the same plate and formed by press processing, so that the outer diameter of the joint edge was 110 mm.
．． A 6vm lower body was made.

Around the entire edge of this lower body, about 5.5 mm on the outer surface side
Adhesive was applied as follows to a width of about 1.5 mm on the inner surface. That is, the copolyester (acid component: polyethylene glycol with an average molecular weight of 800, 25 moles of losophthalic acid, glycol component: 1,4-
(consisting of 90% butanediol) film with a thickness of 8
A piece of 0 μm and 7 mm width is pasted over the entire circumference of the outer edge of the lower body, which has been preheated with high frequency, so that it protrudes by about 1.5 vm, and then, while the edge is heated with high frequency again, this protruding part is rolled with a roll. A lower body was fabricated by folding it back and attaching it to the inner surface, the edges of which were covered with adhesive.

The thus obtained upper body and the lower body coated with adhesive were fitted together, and the mating part was heated with high frequency to melt the adhesive, which was then cooled and solidified to fit the upper body and the lower body together. A metal container with a capacity of about 2 tons was produced.

While planning the joint strength of these metal containers, filling the beer 1. After that, the spout was sealed, sterilized at 65℃ for 60 minutes, and left to age at 50℃ to prevent changes in internal volume or leakage.
The presence or absence of broken nets was observed. In addition, for those filled with carbonated drinks, the amount of aluminum eluted was measured. Furthermore, a dinging test and a drop test were conducted to observe the presence or absence of leakage and broken nets. Table 2 shows these results as the degree of polymerization of vinyl chloride resin, and the concentration of carboxyl groups and/or hydroxyl groups in the vinyl chloride copolymer, which was determined using the calibration curve method from the infrared spectral characteristic absorption of carboxyl groups or hydroxyl groups. Also shown.

<Example 11. 〉 Bright tin-plated steel plate with material thickness of 0.25 mm (T-1
Paint E2 ← (See Group 1 for composition) on the inner and outer surfaces of the material, plating amount + 50150) with a total coating amount of 150 my
/ d m', 6Q m9 / dm2 and naru, J:
After baking at 5 K and 116 mm, the upper body was punched out into a 94 dragon disk and formed using normal press processing, with an inner diameter of 64.48 mm at the edge of the joint and a spout with a diameter of 25 mm in the center. was created.

On the other hand, a tin-plated steel plate with a material thickness of 0.60 x m is approximately 142 mm thick.
Punch it out to the diameter of a dragon, and form it into a tip shape with an inner diameter of about 85 mm between a drawing punch and a drawing die. Next, after subjecting this pot-shaped molded product to a re-drawing process, it has a diameter of approximately 66.1 m.
The ironing process was performed using a No. m ironing punch and die.

The same paint E2 as the upper body is applied to this outer surface with a coating amount of 6o/
dm" with a mandrel coater and then baked. Furthermore, the inner surface is coated with 15% of the epoxy paint.
Spray coat to 0 my/dm2,
After baking, neck-in processing was performed to produce a lower body having an outer diameter of 64.40w+rrt at its circumferential edge.

Next, adhesive was applied over the entire edge of the lower body, with a width of 4 mrn r'iJ on the outer surface and approximately 2 yHrlJ on the inner surface, as follows. That is, a copolyester film (consisting of an acid component of 1 to 75 moles of terephthalic acid, 920 moles of isophthal RF, 5 moles of sepathic acid, and 100 moles of 1,4-butanediol as a glycol component), film thickness 80 μm, width 6 mm, Attach it to the edge of the outer surface of the lower body, which has been preheated with high frequency, so that about two beads protrude over the entire circumference, and then, while heating the edge again with high frequency, fold this protruding part with a roll and attach it to the inner side. A lower body was made whose edges were covered with adhesive.

The upper body thus obtained and the lower body coated with adhesive are fitted together, the fitted part is heated with high frequency to melt the adhesive, and then cooled and solidified to form a bonded capacity of approximately 500
11/! A bottle-shaped metal container was created.

After filling these metal containers with synthetic carbonated drinks, pour 1
'' was tightly capped, sterilized at 42℃ using a can warmer, and subjected to an aging test at 50℃, as well as a drop test and 0.
When the strength of the bottle was evaluated by conducting denting tests at 25°C and 25°C, it was found that performance was sufficiently satisfactory for practical use.

[BRIEF DESCRIPTION OF THE DRAWINGS] Figure 1 is a sectional view showing the upper body and lower body of the metal container of the present invention separately, and Figure 2 is a cross-sectional view showing the upper body and lower body separately, and FIG. 6 is an enlarged view of the cross section of the joint in FIG. 2, and FIG. 4 is a diagram schematically showing the denting test. is the lower body, 2 is the upper body, 3 and 4 are open ends, 5 is the side seam, 6 is the thin wall side wall, 7 is the bottom, 9 is the earthen wall, 10 is the spout, 11 is the metal substrate, 1? ,
Av...! 16 is an adhesive, 14 is a cut edge of a metal material, and 15 is a coating layer.

Claims (1)

[Claims] (1) Based on solid content, (A) degree of polymerization 800 to 4.00
0 vinyl chloride resin particles 10 to 80% by weight, (B)
The carboxyl group and/or hydroxyl group is 5 to 500 mmol/100. ! 10 to 80% by weight of a solvent-soluble vinyl chloride-vinyl acetate-carboxyl group- or hydroxyl group-containing vinyl unit copolymer and (
C) A composition containing 2 to 60% by weight of a solvent-soluble thermosetting resin that is reactive toward carboxy groups and/or hydroxyl groups, the copolymer CB> and the thermosetting resin (C) An adhesive primer for metal containers, characterized in that the vinyl chloride resin particles (A) are present in the form of dispersoids dispersed in the continuous phase as a dispersion medium.