JPWO2013047378A1 - Resin composition - Google Patents

Abstract

Used for film adhesives or film coatings on inner and outer surfaces of trunks and lids of laminating type beverage cans, food cans, etc., especially excellent curability, cured film with extremely little heat energy, Provided is a resin composition having processability, retort resistance, and corrosion resistance and not containing bisphenol A as a raw material. By reacting polyester resin (A) and one or more resins (B) selected from polyamine resin, polyamidoamine resin, and polyamide resin, the film is cured with extremely little heat energy, and excellent adhesion and processing. It is related with the resin composition used for the film adhesive for film cans and drink cans, or the coating material for films which has a property, retort resistance, and corrosion resistance, and does not contain bisphenol A. [Selection figure] None

Description

  The present invention relates to a resin composition used for film adhesives or film coatings for various types of coatings, particularly for laminate-type beverage cans, food cans and the like and inner and outer surfaces of lids and lids.

  For laminated beverage cans and food cans, film adhesives using bisphenol A type epoxy resin are often used, but bisphenol A may affect estrogen action and the brains of fetuses and infants. It has been reported that there is.

  The resin composition using the above-described bisphenol A type epoxy resin is widely used because it has excellent processability, retort resistance, corrosion resistance, and the like. Although an adhesive for a film having a resin composition that does not use bisphenol A as a raw material is demanded from the market, the actual situation is that satisfactory performance as a can application cannot be obtained. Furthermore, the laminated cans that bond the current film to the metal are subjected to post-heat treatment at 200 ° C for several seconds to several minutes after the film lamination, so that the adhesive coating cures in this process and the necessary performance such as retort resistance Is obtained. However, there are problems such as an increase in energy cost and an increase in carbon dioxide emission due to the subsequent heat treatment.

  Examples of thermosetting adhesives for bonding a plastic film to a metal material include polyester / amino adhesives (for example, see Patent Documents 1, 2, and 3) and polyester / block isocyanate adhesives (for example, Patent Documents 2, 3). 4, 5, 6, 9), epoxy / block isocyanate-based adhesive (see, for example, Patent Documents 7 and 8), epoxy / phenol-based adhesive (see, for example, Patent Documents 9 and 10), epoxy / acid-based adhesive Agents (see, for example, Patent Documents 11 and 12) have been reported.

JP 2005-162960 A JP 2000-319363 A JP 2000-328033 A JP-A-11-199851 JP 2004-107409 A JP 2001-123142 A JP 2001-107015 A JP-A-9-279117 JP 2002-206079 A Japanese Patent No. 4006609 Japanese Patent No. 3407551 Japanese Patent No. 3521929

The object of the present invention is particularly used for film adhesives or film coatings on the inner and outer surfaces of trunks and lids of laminate-type beverage cans, food cans, etc., and is particularly excellent in curability and cures the film with very little heat energy. Another object of the present invention is to provide a resin composition that has excellent adhesion, workability, retort resistance, and corrosion resistance and does not contain bisphenol A as a raw material.

  The inventors of the present invention react the polyester resin (A) and any one or more resins (B) selected from a polyamine resin, a polyamidoamine resin, and a polyamide resin to cure the film with very little heat energy, A resin composition that has excellent adhesion, workability, retort resistance, corrosion resistance, and does not contain bisphenol A and is used in film adhesives or film paints for food cans and beverage cans. The invention has been completed.

  That is, the present invention provides a resin composition comprising a polyester resin (A) and any one or more resins (B) selected from a polyamine resin, a polyamidoamine resin, and a polyamide resin. is there.

  The resin composition of the present invention is used as an adhesive for films such as beverage cans and food cans or various metal paints such as film paints or steel sheet adhesives, and without using a bisphenol A type epoxy resin, The curing reaction of the coating proceeds with very little heat energy, and a coating excellent in adhesion, workability, retort resistance, and corrosion resistance can be formed.

  The resin composition of the present invention relates to a resin composition comprising a polyester resin (A) and any one or more resins (B) selected from a polyamine resin, a polyamidoamine resin, and a polyamide resin. Hereinafter, the resin composition of the present invention will be described in more detail.

  The polyester resin (A) used in the resin composition of the present invention preferably has a number average molecular weight of 3,000 to 100,000, more preferably 5,000 to 30,000, still more preferably 10,000. Within the range of ~ 25,000. The number average molecular weight is a number average molecular weight in terms of polystyrene of GPC. The glass transition temperature of the polyester resin (A) is preferably in the range of 0 to 100 ° C., but it may be difficult to satisfy many required performances with one kind of polyester resin. When used alone, for example, when the glass transition temperature of the polyester resin (A) is 0 ° C. to less than 35 ° C., the coating film is given flexibility and processability is excellent. The film will block in the wound state. When the glass transition temperature is 35 ° C. to less than 65 ° C., the film is not blocked, and the workability is improved without impairing the aesthetic appearance of the film. When the glass transition temperature is 65 ° C. to less than 100 ° C., the blocking property is excellent, but the workability is somewhat inferior because the film becomes hard. Accordingly, the polyester resin (A) can be used in combination with a plurality of resins having different glass transition temperatures, and by drawing out the good performance of each polyester resin, a balanced and more excellent resin composition can be obtained. That is, polyester resin (A-1) having a glass transition temperature of 0 to less than 35 ° C./polyester resin (A-2) having a temperature of 35 to less than 65 ° C./polyester resin (A-3) having a temperature of 65 to 100 ° C. = 30 When the ratio is in the range of ˜80 / 10 to 35/10 to 35, the balance between workability and blocking property is remarkably improved.

When the polyester resin (A) contains diphenolic acid as an essential component, it does not contain any one or more resins (B) and bisphenol A selected from polyamine resins, polyamidoamine resins, and polyamide resins (B). Reactivity with the epoxy resin (C-1) is increased and the curing rate is increased. As a result, retort whitening resistance is improved. Moreover, even if it uses polyester (A-1) which made diphenol acid an essential monomer and whose glass transition temperature is 0-35 degreeC in a high ratio, since sclerosis | hardenability improves, a glass transition temperature is low. Both have the feature that the blocking property of the coated film is excellent.
The polyester resin (A) is preferably a linear type. In the case of the straight chain type, the crosslink density of the film is lowered as compared with the polyester resin having a branched structure, and thus the processability is particularly excellent.

The polyester resin (A) may be any one obtained by esterifying a polybasic acid component and a polyhydric alcohol component.
Examples of the polybasic acid component include one or more dibasic acids such as diphenolic acid, phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, fumaric acid, adipic acid, azelaic acid, sebacic acid, and dimer acid. In addition, lower alkyl esterified products of these acids are mainly used, and if necessary, monobasic acids such as benzoic acid, crotonic acid, pt-butylbenzoic acid, trimellitic anhydride, methylcyclohexericarboxylic acid, anhydrous A tribasic or higher polybasic acid such as pyromellitic acid is used in combination.

  Examples of the polyhydric alcohol component include ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 3-methylpentanediol, 1,4-hexanediol, 1,6-hexanediol, and cyclohexanedi. A dihydric alcohol such as methanol is mainly used, and a trihydric or higher polyhydric alcohol such as glycerin, trimethylolethane, trimethylolpropane and pentaerythritol can be used in combination as necessary. These polyhydric alcohols can be used alone or in admixture of two or more.

  As a commercial item of the polyester resin (A) used for the resin composition of the present invention, for example, Byron (VYLON) 300, 500, 560, 600, 630, 650, manufactured by Toyobo Co., Ltd., 670, VYLON GK130, 140, 150, 190, 330, 590, 680, 780, 810, 890, 200, 226, 240, 245, 270 280, 290, 296, 660, 865, 885, VYLON GK250, 360, 640, 880, Unitika Ltd. ELITEL UE-3220, 3500, 3210 , 3215, 3216, 3620, 3240, 3250, 3300, UE-3200, 9200, 320 3203, 3350, 3370, 3380, 3600, 3980, 3660, 3690, 9600, 9800, Toagosei Co., Ltd. Aronmelt PES-310, 318, 334, 316, 360, and the like.

  Any one or more resins (B) selected from the polyamine resins, polyamidoamine resins, and polyamide resins used in the resin composition of the present invention have a faster curing speed and can form a tough film as compared with, for example, melamine resins. Excellent in terms. Compared to the case where there is no adhesive (a type of laminating without interposing an adhesive layer between the film and the base metal) and the case where a resin composition such as polyester / melamine or epoxy / melamine is used as an adhesive, Since the curing characteristics are particularly excellent, it is possible to exhibit particularly superior performance in terms of retort resistance, corrosion resistance, workability, and the like of the laminated steel sheet.

  Examples of the polyamine resin used in the resin composition of the present invention include aliphatic amines such as diethylenetriamine, triethylenetriamine, and triethylenepentamine, and alicyclic polyamines such as isophoronediamine. In addition, an epoxy resin or acrylonitrile may be added to an aliphatic polyamine or modified by reacting formaldehyde with phenol to improve workability, reduce irritation, or improve mechanical properties. Examples of the aromatic polyamine include metaphenylenediamine, diaminodiphenylsulfonic acid, and diaminodiphenylmethane. Examples of commercially available products include EPICLON EXB-353 manufactured by DIC Corporation, Ancamine 2596 manufactured by Air Products Japan Co., Ltd., Ancamine 2605, and the like.

  The polyamide amine resin and the polyamide resin used in the present invention are compounds synthesized by, for example, a dehydration condensation reaction between fat and fatty acid and polyamine, and among them, the polyamide amine resin is more preferable. Commercially available products include Sanyo Kasei Polyamide L-15-3, Polyamide L-43-3, Air Products Japan Co., Ltd. Ancamide 2137, Sunmide 330, 328A, Sunmide X-2000, etc. Is mentioned.

An epoxy resin (C) can be used in combination with the resin composition of the present invention. The epoxy resin (C) mainly improves the adhesion of the coating film. Examples of commercially available epoxy resins include BPA type modified novolak type epoxy resins such as EPIKOAT 1001, EPIKOAT 1004, EPICLON N-865, EPICLON N-870, and the like. Among the epoxy resins (C), an epoxy resin (C-1) not containing bisphenol A is preferable. Examples of the epoxy resin (C-1) include phenol novolac epoxy resins such as EPICLON N-730, EPICLON N-740, and EPICLON N-770 manufactured by DIC Corporation, EPICLON N-660, and EPICLON N-665. , EPICLON N-670, EPICLON N-673, EPICLON N-680, EPICLON N-690, EPICLON N-695, AER ECN-1273 manufactured by Asahi Kasei Epoxy Co., Ltd. An epoxy resin etc. are mentioned.
The epoxy resin not containing bisphenol A is particularly preferable for food use because unreacted bisphenol A does not elute.
The epoxy resin not containing bisphenol A means an epoxy resin not containing a structure derived from the bisphenol A skeleton.

  In the resin composition of the present invention, a metal alkoxide compound and / or a metal chelate compound (F) can be used. The compound (F) reacts with the polyester resin (A), any one or more resins (B) selected from a polyamine resin, a polyamidoamine resin, and a polyamide resin and an epoxy resin (C-1) that does not contain bisphenol A. It also acts as a crosslinking curing catalyst. A crosslinking reaction proceeds between the functional group of each resin and the metal alkoxide compound and / or metal chelate compound (F). Compared to the case where there is no metal alkoxide-based compound and / or metal chelate-based compound (F), this crosslinking reaction has a markedly faster curing rate, resulting in excellent adhesion and processing with very little heat energy. , Retort resistance and corrosion resistance can be exhibited. For example, existing laminate cans are baked at 180 ° C. or higher for several seconds to several minutes after laminating films, and then the post-heating is used to harden the adhesive coating to bring out the above-mentioned performance. In the adhesive using the resin composition, the adhesive film is sufficiently cured only by momentary heating at the time of laminating, and performance equivalent to or higher than that obtained after post-heating is obtained. Therefore, a post-heating step in the manufacturing process is not required, and the manufacturing efficiency is remarkably improved. In addition, the emission of carbon dioxide can be reduced, which can be a practically extremely useful adhesive. Furthermore, by incorporating a metal in the coating, the strength of the coating is improved, and as a result, the function of dramatically improving impact resistance and corrosion resistance is imparted.

  Examples of the metal alkoxide compound and / or metal chelate compound (F) include alkoxide metal compounds such as aluminum, titanium, tin, and zirconium, and metal chelate compounds in which acetoacetic acid is coordinated to the metal.

The total amount of any one or more resins (B) selected from the group consisting of 50 to 90% by weight of the polyester resin (A), polyamine resin, polyamidoamine resin, and polyamide resin in the ratio of the total resin solids is 0.00. 1 to 50% by weight, epoxy resin (C), particularly preferably epoxy resin (C-1) not containing bisphenol A, 0.5 to 30% by weight, metal alkoxide compound and / or metal chelate compound (F) It is preferable that it is 0.01 to 10 weight%. The ratio of the polyester resin (A) is preferably in the range of 55 to 85% by weight. If the ratio of the polyester resin A is lower than 50% by weight, the workability is deteriorated, and if it exceeds 85% by weight, the curability is insufficient and the retort resistance is lowered. The total amount of any one or more resins (B) selected from the group consisting of polyamine resins, polyamidoamine resins and polyamide resins is preferably 3 to 30% by weight, and if it is lower than 0.1% by weight, the curability is insufficient. The retort resistance is inferior, and if it exceeds 50% by weight, the workability deteriorates. The ratio of the epoxy resin (C), particularly preferably the epoxy resin (C-1) not containing bisphenol A, is preferably 5 to 25% by weight, and if it is lower than 0.5% by weight, the adhesion is lowered, resulting in corrosion resistance. When it exceeds 30% by weight, retort whitening resistance becomes inferior. The ratio of the metal alkoxide compound and / or the metal chelate compound (F) is preferably 0.1 to 7% by weight. If the content is lower than 0.01% by weight, the effect of rapid curing cannot be obtained. If the content exceeds 10% by weight, the film becomes hard and the workability becomes inferior.
The blending ratio of any one or more resins (B) and epoxy resin (C) selected from the group consisting of polyamide resins is the active hydrogen equivalent (b) of resin (B) and the epoxy equivalent (c) of epoxy resin (C). ) And the ratio [(b) / (c)] is preferably 0.3 to 1.2.

  The resin composition of the present invention can further contain a curing catalyst (I). By adding the curing catalyst (I), the condensation reaction between the polyester resin and the phenol resin, the polyester resin and the novolac epoxy resin, or the phenol resin can be promoted. Examples of the curing catalyst (I) include, in particular, typical ones, inorganic acids such as phosphoric acid, organic acids such as dodecylbenzenesulfonic acid and toluenesulfonic acid, and those blocked with an amine or the like. Can be used. The compounding ratio of the curing catalyst (I) is preferably 0.01 to 5% by weight in the total solid content.

  Examples of the pigment (J) that can be used in the resin composition of the present invention include chromate (yellow lead, chromium vermillion) ferrocyanide (bitumen), sulfide (cadmium yellow, cadmium red), and oxide. (Titanium oxide, bengara, iron black, zinc oxide) sulfate (barium sulfate, lead sulfate), silicate (ultraviolet, calcium silicate), carbonate (calcium carbonate, magnesium carbonate) phosphate (cobalt violet) metal powder (aluminum Powder, bronze, inorganic pigments such as carbon (carbon black), azo (benzidine yellow, Hansa Yellow, Vulcan orange, permanent red F5R, carmine 6B, lake red C, chromoftal red, chromoftal yellow), phthalocyanine Series (Phthalocyanine blue, Phthalocyanine green) , Vat dyes (induslen blue, thioindigo bordeaux) dyed lakes (eosin lake, quinoline yellow, rhodamine lakes, methyl violet lakes), quinacrine (sinkasia red, shinkasia violet) dioxinsine (PV fast violet) BL) and the like, and these may be used alone or in combination. These pigments make it possible to color the coating film and impart design properties, and arbitrary organic pigments and inorganic pigments can be added to the required design.

  The blending ratio of the pigment (J) is preferably 0.1 to 70% by weight in the total solid content.

  It is preferable to add a conductive polymer (D) to the resin composition of the present invention in order to improve the higher corrosion resistance and satisfy the required performance required as a primer for a coated steel sheet. This makes it possible to create an environment by not containing heavy metal rust preventive pigments.

  The said conductive polymer (D) can promote the passivation of a base metal, and can provide damage | wound corrosion resistance to a metal plate. Since the oxidation-reduction potential of the conductive polymer is noble with respect to the potential of the base metal, an oxidation reaction of the base metal and a reduction reaction of the conductive polymer occur at the interface with the base metal to form a stable passive film at the interface. Since the passive film is an insulator and is dense, it functions as a barrier layer against corrosion factors. Therefore, the corrosion resistance of the base metal can be greatly improved. Here, it is known that the oxidation-reduction reaction of the conductive polymer is reversible, and returns to the original state by a coupling reaction with the reduction reaction of dissolved oxygen. That is, the conductive polymer can be expected to have an effect of permanently preventing the base metal without deteriorating itself due to its reversible redox property. Since the above anticorrosion process promotes spontaneous passivation of the base metal in a corrosive environment, it can be considered that the conductive polymer has a kind of self-repair action. Therefore, even if a scratch penetrating the coating occurs, it is possible to remarkably suppress the progress of corrosion by forming a passivating coating around the wound.

The conductive polymer (D) of the present invention is a semiconductor in the undoped state and has a band gap. Therefore, in order to impart conductivity, a dopant (a trace amount of a chemical substance having an electron donating or accepting property) is added, and π electrons are taken away from the conjugated system of the main chain of the conductive polymer, so It is necessary to generate holes. The dopant (E) is preferably one or a mixture of two or more selected from halogens, proton acids, Lewis acids, transition metal halides, and alkali metals. Of these, halogens, protonic acids and Lewis acids are particularly preferred because of their stable anticorrosive ability. Specifically, polyaniline, polypyrrole, polythiophene, polyalkylthiophene, polyalkyldioxythiophene, polyisothianaphthene, polyphenylene, polyfuran. , Polyphenylene vinylene, polyacene and derivatives thereof, and one or more mixtures selected from copolymers of these monomers.
As the halogens, bromine, chlorine, iodine and the like can be used, and as the protonic acid, organic carboxylic acid, organic sulfonic acid, organic phosphonic acid, phosphoric acid, polyphosphoric acid and the like can be suitably used. As the Lewis acid, metal halides such as FeCl3, FeOCl, TiCl4, ZrCl4, SnCl4, MoCl5, WCl5, BF4, BCl3, and PF5 can be used.
Among them, a protonic acid is preferable, and polymer acids such as polystyrene sulfonic acid, polyvinyl sulfonic acid, and polyphosphoric acid are particularly preferable. Since these have a film-forming ability, they increase the continuity of the resin serving as the adhesion layer and are effective for adhesion and corrosion resistance.
The addition amount of the dopant is in the range of 0.01 to 1.0 mol with respect to 1 mol of the conductive polymer added to the resin. If the added amount of the dopant is less than 0.01 mol with respect to 1 mol of the conductive polymer, the number of carriers generated on the polymer main chain is insufficient and sufficient electrical conductivity cannot be obtained. Since the anticorrosion effect of the conductive polymer depends on the smooth exchange of electrons with the metal to be anticorrosive, the decrease in conductivity reduces the passivation ability and the scratch corrosion resistance is poor. On the other hand, if the additive amount of the dopant exceeds 1 mol with respect to 1 mol of the conductive polymer, the treatment liquid becomes unstable and the workability of the primer film is deteriorated, and there is a concern that the corrosion resistance of the scratches is lowered. Therefore, the addition amount of a dopant is prescribed | regulated in the range of 0.01-1.00 mol with respect to 1 mol of conductive polymers.

  A rust inhibitor (S) can be used in the resin composition of the present invention. The rust preventive agent (S) is not particularly limited, but examples of the inorganic rust preventive agent include zinc oxide, zinc phosphate and aluminum phosphate, and examples of the organic rust preventive agent include tannic acid. .

Furthermore, as this component, you may add a phenol resin (P) as resin as needed.
In this case, when the polyester resin (A) contains diphenolic acid as an essential component, the reactivity with the phenol resin (P) increases and the curing rate increases, resulting in improved retort whitening resistance. Moreover, even if it uses polyester (A-1) which made diphenol acid an essential monomer and whose glass transition temperature is 0-35 degreeC in a high ratio, since sclerosis | hardenability improves, a glass transition temperature is low. Both have the feature that the blocking property of the coated film is excellent.

  Further, when a phenol resin (P) is used, a titanium alkoxide compound and / or a titanium chelate compound (F-1) in which the metal alkoxide compound and / or metal chelate compound (F) is titanium in particular is used. If it exists, the coating is colored yellow by the interaction with the phenol resin (P).

  For cans and lids of beverage cans and food cans, gold-colored ones are preferred from the viewpoint of design. As a general production example of a laminated can having a gold color, a yellow colored film is bonded to a metal directly or using an adhesive. In this case, the yellow colored film is considerably more expensive than the generally used colorless film, which results in a direct increase in can price. By using a phenol resin, a laminate can excellent in design can be produced without using the yellow colored film.

  To exemplify only typical ones as the phenol resin (P), monofunctional phenolic compounds such as carboxylic acid, m-cresol, m-ethylphenol, 3,5-xylenol, m-methoxyphenol or p- Alkaline catalyst for various bifunctional phenols such as cresol, o-cresol, p-tert-butylphenol, p-ethylphenol, 2,3-xylenol, 2,5-xylenol, m-methoxyphenol and formaldehyde It was synthesized in the presence of These phenol compounds can be used alone or in admixture of two or more. Moreover, the thing of the form which etherified one part or all part of the methylol group contained in a phenol resin by alcohol with 1-12 carbon atoms can also be used.

The ratio of the phenol resin (P) is preferably 20 to 40% by weight based on the total resin solid content, and if it is lower than 10% by weight, the curability is insufficient and the retort resistance is inferior, and if it exceeds 50% by weight, the workability is deteriorated. To do.
The ratio of the phenol resin (P) is preferably 10% by weight or more from the viewpoint of curability and retort resistance, and preferably 50% by weight or less from the viewpoint of good workability. In particular, it is preferably 20 to 40% by weight.

  It is useful to add zinc oxide (H) in order to provide a resin composition having the characteristics of improving the excellent flavor retention and corrosion resistance with respect to the contents having a sulfur-based compound. Examples of the content having a sulfur compound include a sulfite compound added for the purpose of preventing oxidation of wine, salmon, salmon, corn, and asparagus. From these contents, sulfur-based gas is generated, which adversely affects the flavor of the contents and corrodes the container because it is highly corrosive to metals. Zinc oxide (H) functions as a sulfur-based gas catcher agent and adsorbs the gas to the coating film. As a result, when zinc oxide (H) is present, it is possible to exhibit excellent corrosion resistance and content retention for a specific compound having a sulfur compound.

  The content ratio of zinc oxide (H) in the total solid content is preferably 0.1 to 70% by weight, more preferably 1 to 50% by weight, more preferably 5 to 30% by weight. .

  The resin composition of the present invention can be preferably used for an adhesive for laminated cans such as a PET film. Furthermore, it can be used as a coating agent for various materials such as aluminum and tin-plated steel sheets, or pre-treated metals, and other metal materials such as steel, and other materials and processed products such as wood and films. Good. Hereinafter, the use as an adhesive for laminate cans will be described.

  The solvent that can be used for the adhesive for a film using the resin composition of the present invention is not particularly limited. For example, aromatic hydrocarbons such as toluene, xylene, Solvesso # 100, Solvesso # 150, hexane, heptane, etc. And aliphatic organic solvents such as octane and decane, and various organic solvents such as methyl acetate, ethyl acetate, isopropyl acetate, butyl acetate, amyl acetate, ethyl formate and butyl propionate. Water-miscible organic solvents include alcohols such as methanol, ethanol, propanol, and butanol, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, ethylene glycol (mono, di) methyl ether, ethylene glycol (mono, di) ethyl ether, ethylene Glycol monopropyl ether, ethylene glycol monoisopropyl ether, monobutyl ether, diethylene glycol (mono, di) methyl ether, diethylene glycol (mono, di) ethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, triethylene glycol (mono, di) methyl Ether, propylene glycol (mono, di) methyl ether, propylene glycol monopropyl ether , Propylene glycol monobutyl ether, dipropylene glycol (mono, di) include various organic solvents glycol ether such as methyl ether.

  Conventionally known lubricants, antifoaming agents, leveling agents, pigments, anti-blocking agents such as silica, and the like can be added to the film adhesive using the resin composition of the present invention. In addition, other curing agents such as a melamine resin, a benzoguanamine resin, and an isocyanate resin may be used in combination as a curing auxiliary agent, and these can be used in combination with an appropriate one depending on the drying conditions and lamination conditions of the film.

  The adhesive for film using the resin composition of the present invention can be applied by various means such as air spray, airless spray or electrostatic spray, such as various spray coating, dip coating, roll coater coating, gravure coater and electrodeposition coating. It can be applied as an adhesive to metal substrates such as steel plates and aluminum plates for cans and PET films.

  The dry coating amount of the adhesive for film using the resin composition of the present invention is preferably in the range of 0.1 to 20 μm. If it exists in the range of 0.1-20 micrometers, it is excellent in continuous uniform application | coating property, there is no problem of design property, retort resistance and adhesiveness can be hold | maintained, and the blocking property at the time of film winding is also eliminated. When the thickness is less than 0.1 μm, it is easy to cause difficulty in continuous uniform coating properties, and it is somewhat difficult to develop physical properties and design properties. In addition, the barrier property of water vapor in the pressurized hot water treatment is slightly inferior, moisture tends to stay at the adhesive / plastic film interface, and retort whitening may occur. On the other hand, if it exceeds 20 μm, the solvent detachability after coating is lowered, the workability is remarkably lowered, and the problem of residual solvent is likely to occur, whereby the blocking property at the time of winding the film may be significantly lowered.

  Although it does not specifically limit as a plastic film, It can use with respect to a pet film, a polyethylene-type film, a polypropylene film, a polyvinyl chloride-type film, and an acrylic film. Examples of the steel plate to be laminated include a sheet-shaped or coil-shaped steel plate, steel foil, iron foil, and a steel plate that has been surface-treated. An aluminum plate can be used in addition to the steel plate. In particular, an electrolytic chromic acid-treated steel sheet having an upper layer of chromium hydrated oxide and a lower layer of metallic chromium, ultrathin tin plating, nickel plated steel sheet, galvanized steel sheet, chromium hydrated oxide coated steel sheet or phosphate Examples thereof include steel plates treated with chromate.

  An example of a method of laminating a film coated with an adhesive composition for a plastic film laminated steel plate on a steel plate will be given. An adhesive is uniformly applied to the plastic film so as to have a dry film thickness of about 2 μm, and the solvent is evaporated. The plastic film to be used may be a pre-printed film. A plastic film and a steel plate are thermocompression-bonded by setting the plate temperature or heating roll to an arbitrary temperature of 180 to 250 ° C. via an adhesive. The adhesive using the resin composition of the present invention is instantly cured by heat only at the time of laminating, and exhibits adhesiveness and the like. The plastic film laminated steel sheet thus obtained is excellent in design properties, corrosion resistance, work adhesion and retort resistance, and can be used for various applications.

  Hereinafter, the present invention will be specifically described with reference to Examples. In the examples, “parts” and “%” represent “parts by weight” and “% by weight”, respectively.

Example of Synthesis 1 (Synthesis of polyester resin (A-1-1) containing diphenolic acid as an essential component)
As an acid component, 50 parts by weight of terephthalic acid, 112 parts by weight of isophthalic acid, 4.9 parts by weight of diphenolic acid, and 50 parts by weight of 2-ethyl-2-butyl-1,3-butanediol as a polyhydric alcohol component, , 4-Butanediol 99 parts by weight, 1,4-cyclohexanedimethanol 48 parts by weight, titanium tetrabutoxide 0.07 part by weight are charged into a 2 L flask, gradually heated to 220 ° C. over 4 hours, and water is retained. Esterification was carried out. After distilling a predetermined amount of water, the polymerization was carried out under reduced pressure to 10 mmHg over 30 minutes, the temperature was raised to 250 ° C., and the latter polymerization was carried out at 1 mmHg or less for 50 minutes. Next, the polymerization under reduced pressure was stopped, the mixture was cooled to 220 ° C. under a nitrogen stream, 1.9 parts by weight of trimellitic anhydride was added, and the mixture was stirred at 220 ° C. for 30 minutes to modify the carboxyl group (post-addition), and then resin The polyester resin (A-1-1) having a number average molecular weight of 22,000, an acid value of 5 (mgKOH / g), and a glass transition temperature of 30 ° C. was obtained. Then, it cooled to 60 degrees C or less, and diluted with the mixed solution of methyl ethyl ketone / toluene = 50/50, and obtained the polyester resin (A-1-1) solution of 40% of non volatile matters.

The following raw materials were blended and stirred at the ratios shown in Tables 1 to 4 (numbers in the table indicate solid content weight ratios), and adhesives for films of Examples 1 to 33 and Comparative Examples 1 to 9 were produced. .
(1) Polyester resin (A-1-1)
Number average molecular weight 22,000, acid value 5 (mg KOH / g), glass transition temperature 30 ° C., 40% solution (dissolved in a mixed solution of methyl ethyl ketone / toluene = 50/50)
(2) Polyester resin (A-1-2) = Byron GK-140, Toyobo Co., Ltd. number average molecular weight 13,000, acid value 2 (mgKOH / g) or less, glass transition temperature 20 ° C., 40% solution (Dissolved in a mixed solution of methyl ethyl ketone / toluene = 50/50)
(3) Polyester resin (A-2-1) = Byron GK-250, manufactured by Toyobo Co., Ltd., number average molecular weight 10,000, acid value 2 (mgKOH / g) or less, glass transition temperature 60 ° C., 40% solution (Dissolved in a mixed solution of methyl ethyl ketone / toluene = 50/50)
(4) Polyester resin (A-3-1) = Byron GK-640, number average molecular weight 18,000 manufactured by Toyobo Co., Ltd., acid value of 4 (mg KOH / g) or less, glass transition temperature 79 ° C., 40% solution (Dissolved in a mixed solution of methyl ethyl ketone / toluene = 50/50)
(5) Polyamideamine resin (B-1) = SUNMIDE 328A, manufactured by Air Products Japan, 100% active ingredient
(6) Epoxy resin (C-1) = Epicron N-660, cresol novolak type epoxy resin manufactured by DIC Corporation, 50% methyl ethyl ketone solution (epoxy resin not containing bisphenol A)
(7) Metal chelate compound (F-1-1) = TC-200, titanium octylene glycol chelate manufactured by Matsumoto Fine Chemical Co., Ltd. (8) Metal alkoxide compound (F-2-1) = ZA-65, Matsumoto Fine Chemical ( Zirconium butoxide (9) Metal chelate compound (F-2-2) = ZC-150, Zirconium acetylacetone chelate (10) Curing catalyst (I-1) = NACURE5925 manufactured by Enomoto Kasei Co., Ltd. Dodecylbenzenesulfonic acid (catalyst), 25% solution (11) Epoxy resin (G-1-1) BPA type epoxy resin jER1009 (Mitsubishi Chemical, epoxy equivalent 2600)
(12) Epoxy resin (G-1-2) BPA type epoxy resin jER1001 (Mitsubishi Chemical, epoxy equivalent 475)
(13) Melamine resin (M-1) = Cymel 303, manufactured by Nippon Cytec Industries, Inc., 100% active ingredient
(14) Phenol resin (P-1) = TD2495, DIC Corporation paracresol phenol resin, 50% normal butanol solution (15) Conductive polymer (D-1) = Polyaniline 6% toluene solution, dopant (E -1): Dodecylbenzenesulfonic acid, TA Chemical Co., Ltd. (16) Rust preventive agent (S-1) Tannic acid AL, Fuji Chemical Industry Co., Ltd. (17) Zinc oxide (H-1) = MZ- 300, manufactured by Teika Co., Ltd. average primary particle size 35 nm, 100% solid product

[Production of test panel]
(1) The film adhesives of Examples 1 to 33 and Comparative Examples 1 to 9 were applied to a PET film having a thickness of 12 μm with a bar coater so as to have a dry film thickness of 2 μm, and dried at 115 ° C. for 8 seconds.
(2) This film was laminated on a metal plate (tin-free steel) at 225 ° C.-3.6 m / min to obtain a test piece. Subsequently, it measured according to the evaluation test method shown below.

[Evaluation test method]
1. The appearance of the laminated steel sheet, such as the appearance of laminate appearance bubbles and film wrinkles, was visually evaluated in four stages.
Very good (◎), good (○), slightly bad (△), bad (×)

2. Adhesiveness: Cross-cut cellophane adhesive tape peeling test A cross-cut was put on a laminated steel sheet film, and the area peeled when forcedly peeled with a cellophane adhesive tape after high-temperature hot water treatment at 125 ° C for 30 minutes was expressed in%. JIS G3312

3. Workability: Cap adhesion test Diameter of φ26mm, height 17mm, formed into a cap of 17mm, and after hot water treatment at 125 ° C for 30 minutes, the side of the cap was forcibly peeled off with cellophane adhesive tape. Evaluation was made in 4 stages. Very good (◎), good (○), slightly bad (△), bad (×)

4). The whitening state of the adhesive layer of the laminated steel sheet after the retortability at 125 ° C. for 30 minutes and the high temperature hot water treatment was visually observed and evaluated in the same four steps as described above.
Very good (◎), good (○), slightly bad (△), bad (×)

5. The adhesive coated surfaces of the sample film cut to a blocking property of 8 cm × 8 cm are bonded together, held in a 40 ° C. atmosphere at a pressure of 0.3 MPa for 72 hours, and then the bonded films are peeled at an angle of 180 ° at a peeling rate of 1000 mm / min. The peel strength when peeled with was measured.
Peel strength values: less than 20 g / cm (◎), 20-40 g / cm (◯), 41-60 g / cm (Δ), 61 g / cm or more (x).

6). The corrosion resistance test sample was subjected to a retort treatment at 120 ° C. for 90 minutes with an aqueous solution containing 3% sodium chloride and 3% citric acid, and the state of the sample was visually determined.
A: No peeling.
Δ: There is little peeling.
X: There is much peeling.

7). The b value measured with a spectrophotometer SE2000 manufactured by Nippon Denshoku was used. JIS Z8722

8). The content retention test sample is subjected to a retort treatment at 120 ° C. for 90 minutes with a 0.05% aqueous sodium sulfide solution, and the presence or absence of sulfur (S) adsorbed on the test sample is confirmed by fluorescent X-ray. ○: Sulfur (S) There is adsorption.
X: There is no adsorption of sulfur (S).

The evaluation results are shown in Tables 1 to 4. The numbers in the table indicate the solid content weight ratio.

  The resin composition of the present invention does not contain bisphenol A, which may adversely affect the human body in terms of estrogen action, etc., and is cured with very little heat energy, and has processability, coating film hardness, water resistance and curability. It can be widely used as an adhesive for laminated can film, paint for film or various metal paint.

Claims (13)

A resin composition comprising a polyester resin (A) and at least one resin (B) selected from the group consisting of a polyamine resin, a polyamidoamine resin, and a polyamide resin. The resin composition of Claim 1 containing an epoxy resin (C). The resin composition of Claim 1 containing a conductive polymer (D) and a dopant (E). The resin composition according to claim 2, wherein the epoxy resin is an epoxy resin (C-1) that does not contain bisphenol A. The resin composition according to claim 2, comprising a metal alkoxide compound and / or a metal chelate compound (F). The resin composition according to claim 1, wherein the polyester resin (A) has a number average molecular weight of 3,000 to 100,000 and a glass transition temperature of 0 to 100 ° C. The polyester resin (A) has a glass transition temperature of 0 to less than 35 ° C. polyester resin (A-1), 35 to 65 ° C. polyester resin (A-2), and 65 to 100 ° C. polyester resin ( The resin composition according to claim 1, wherein the resin composition is one or more resins selected from the group consisting of A-3). The ratio of the polyester resin (A) to the polyester resin (A-1), the polyester resin (A-2), and the polyester resin (A-3) [(A-1) / (A-2) / (A-3) ] Is compounded by (30-80) / (10-35) / (10-35) (weight ratio). The resin composition according to claim 6, wherein the polyester resin (A) contains diphenolic acid as an essential component. Furthermore, the resin composition of Claim 5 containing a phenol resin (P). The proportion of the total resin solids is 50 to 89% by weight of the polyester resin (A), 10 to 45% by weight of the phenol resin (P), 0.5 to 20% by weight of the epoxy resin (C), a polyamine resin, One or more resins (B) selected from the group consisting of a polyamide amine resin and a polyamide resin are 0.1 to 10% by weight, a metal alkoxide compound and / or a metal chelate compound (F) is 0.01 to 10% by weight. The resin composition according to claim 10, which is%. The resin composition according to claim 1 containing zinc oxide (H). The resin composition according to claim 12, comprising a curing catalyst (I).