JP2007211200A - Active energy ray-curable resin composition for plastic film coating and its use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an active energy ray-curable resin composition for plastic film coating, which exhibits excellent adhesiveness even to a poor bondable plastic film, coating suitability such as gravure printing, etc., curability, followingness to shrink processing, etc., forms a strong resin layer having excellent chemical resistance, scuffing resistance, etc., after curing. <P>SOLUTION: The active energy ray-curable resin composition for plastic film coating is a resin composition comprising an oxetane compound, an epoxy compound and a thermoplastic resin having an acid value of ≥20 (mg-KOH/g-resin). The acid value of the mixture of the three components of the oxetane compound, the epoxy compound and the thermoplastic resin is 0.1-90 (mg-KOH/g-resin). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to an active energy ray-curable resin composition used for application to a plastic film, an adhesive for a plastic film comprising the resin composition, and a printing ink. The present invention also relates to a plastic label formed by applying the resin composition, adhesive or printing ink.

  Currently, plastic bottles such as PET bottles and metal bottles such as bottle cans are widely used as containers for beverages such as tea and soft drinks. These containers are often equipped with plastic labels for display, decoration, and functionality. These plastic labels have decoration, workability (followability to containers), wide display area, etc. For this reason, shrink labels and stretch labels are widely used. Usually, a coating agent such as ink is applied and printed on the surface of these labels for the purpose of imparting decorative properties such as letters and designs, and providing functionality such as scratch prevention and slipperiness.

  The resin composition used in these coating agents is required to have processability suitable for each labeling process such as shrink processing, and the coating layer after curing may be scraped off in the distribution process and decorated. And toughness that does not degrade the function is required. In particular, in the shrink film field, as the shape of containers has become more complex in recent years, demands for improving workability such as the ability to follow deformation during shrink processing have become increasingly severe. There is an urgent need to achieve a high level of compatibility. In addition, there is an increasing demand for imparting functions according to various uses such as chemical resistance, heat resistance and water repellency.

  Further, when these coating agents are used as printing inks, gravure printing is generally used as a coating method from the viewpoint of having excellent printability (expression). Since gravure ink usually contains a large amount of organic solvent, it is necessary to process the solvent evaporated in the manufacturing process, and the equipment itself and maintenance costs such as catalyst replacement are expensive. The big burden is a problem. On the other hand, in the case of a water-based ink that does not use an organic solvent, drying takes time, so that there is a problem that printing speed is slow and productivity is lowered. As described above, in addition to the above requirements, coating agents for gravure printing are required to be usable without using an organic solvent and to have excellent curability capable of high-speed printing.

  In order to satisfy the above requirements, improvement of a coating agent that is based on an epoxy resin that is excellent in coating property and that does not substantially use a solvent is being promoted. An energy ray curable composition comprising an epoxy compound mixed with an oxetane compound as a resin composition that imparts flexibility to an epoxy resin having relatively brittle properties and achieves both coatability, curability and followability. Is known (see, for example, Patent Document 1). However, it is limited to the examination of basic physical properties such as viscosity and tensile strength of the cured product, and no examination has been made on functions such as practical coating processability, followability to shrink processing, chemical resistance, It was insufficient for application to label applications, particularly shrink label applications.

  In addition, cationically polymerizable resins such as the above epoxy resins and oxetane resins are less susceptible to curing inhibition by oxygen than ordinary radically polymerizable resins, but they are not suitable for some types of substrates such as polyethylene films. When used, an additive or the like in the film becomes a curing-inhibiting substance, resulting in a problem that the curing speed and adhesiveness are extremely lowered. In order to adhere ink to such a difficult-to-adhere base film, or to use as a laminating adhesive or a cylindrical label center seal agent, a highly soluble solvent is used, There is a problem of the above-mentioned solvent-containing problems, quality stability, and productivity reduction.

  That is, an active energy ray-curable resin composition that satisfies the above requirements of toughness, curability, coatability, etc., and that exhibits sufficient adhesion even to difficult-to-adhere films that are difficult to adhere has been obtained. There is no current situation.

JP-A-11-140279

  The object of the present invention is to exhibit excellent adhesion particularly to difficult-to-adhere plastic films, and also has good coating suitability and curability such as gravure printing, and further has chemical resistance after curing. Another object of the present invention is to provide an active energy ray-curable resin composition for coating a plastic film that forms a strong cured resin layer having excellent scratch resistance, resistance to scratching, followability to shrink processing, and the like. Another object of the present invention is to provide a printing ink for a plastic film comprising the resin composition, an adhesive for a plastic film, and a plastic label having excellent chemical resistance and scratch resistance, to which the resin composition is applied. .

  As a result of intensive studies to achieve the above object, the present inventors use an oxetane compound, an epoxy compound, and a thermoplastic resin having a specific acid value, and control the acid value of these mixtures to a specific value. Has dramatically improved adhesion to difficult-to-adhere films, and has excellent productivity, processability and toughness after curing, an active energy ray-curable resin composition, a printing ink comprising the resin composition, and adhesion The present invention has been completed by finding that an agent and a plastic label having such properties can be obtained.

  That is, the present invention is a resin composition comprising an oxetane compound, an epoxy compound, and a thermoplastic resin having an acid value of 20 (mg-KOH / g-resin) or more, the oxetane compound, the epoxy compound, and the thermoplastic resin. An active energy ray-curable resin composition for coating a plastic film is provided, wherein the acid value of the mixture of the three components is 0.1 to 90 (mg-KOH / g-resin).

  Furthermore, in the present invention, the thermoplastic resin having an acid value of 20 (mg-KOH / g-resin) or more is a thermoplastic resin having an acid value of 20 to 550 (mg-KOH / g-resin). Provided is an active energy ray-curable resin composition for plastic film coating.

  Furthermore, in the present invention, the weight ratio of the oxetane compound and the epoxy compound is 2: 8 to 8: 2, and the addition amount of the thermoplastic resin is 0 with respect to 100 parts by weight of the total amount of the oxetane compound and the epoxy compound. Provided is an active energy ray-curable resin composition for coating a plastic film, which is .1 to 30 parts by weight.

  Furthermore, the present invention provides the active energy ray-curable resin composition for plastic film coating, wherein the thermoplastic resin is a styrene / maleic anhydride copolymer or a carboxyl group-containing (meth) acrylic polymer.

  Furthermore, the present invention provides the active energy ray-curable resin composition for plastic film coating, which is for gravure printing or flexographic printing.

  Furthermore, the present invention provides the active energy ray-curable resin composition for coating a plastic film, wherein the plastic film is a polyolefin film.

  Furthermore, this invention provides the adhesive agent for plastic films which consists of said active energy ray curable resin composition for plastic film coating.

  Furthermore, this invention provides the printing ink for plastic films formed by adding a sensitizer and a pigment to the said active energy ray curable resin composition for plastic film coating.

  Furthermore, the present invention provides a plastic label obtained by coating the plastic film with the active energy ray-curable resin composition for plastic film coating, the adhesive for plastic film, or the printing ink for plastic film.

  Furthermore, this invention provides the said plastic label whose plastic film is a shrink film.

  The active energy ray-curable resin composition for coating a plastic film of the present invention is excellent in adhesiveness to a plastic film, and particularly exhibits excellent adhesiveness even to a film having low adhesiveness such as a polyethylene film. Further, since it has a low viscosity, it can be applied to a plastic film by gravure printing or flexographic printing. Furthermore, after curing, it is excellent in scratch resistance, resistance to scratching and chemical resistance. For this reason, the resin composition of the present invention is particularly useful as an adhesive for printing inks and plastic films. Reflecting these characteristics, the plastic label coated with the resin composition of the present invention is particularly useful as a label used for plastic containers such as glass bottles and PET bottles. In addition, since the cured resin layer made of the resin composition of the present invention has good followability to deformation of the base film such as shrink processing, production efficiency is improved.

  Hereinafter, an active energy ray-curable resin composition for coating a plastic film of the present invention (hereinafter simply referred to as a resin composition), a printing ink for a plastic film comprising the resin composition, an adhesive for a plastic film, and a plastic label Will be described in more detail.

  The resin composition of the present invention is an active energy ray-curable compound that can be cured by active energy rays such as visible light, ultraviolet rays, and electron beams. Unlike the case of thermosetting, it is also preferably used for a base material that easily deforms due to heat, such as a shrink film. Among the active energy rays, ultraviolet curable and near ultraviolet curable are particularly preferable. A preferable absorption wavelength is 300 to 460 nm.

  The resin composition of the present invention comprises an oxetane compound (hereinafter referred to as component A), an epoxy compound (hereinafter referred to as component B), and a thermoplastic resin having an acid value of 20 (mg-KOH / g-resin) or more. Hereinafter, component C) is contained as an essential component. When the above three components are not included, the effect of the present invention cannot be obtained.

  In addition to the above three components, the resin composition of the present invention contains a photopolymerization initiator in order to exhibit active energy ray curability. In addition, for the purpose of imparting various other properties, resins such as silicone having epoxy groups (epoxy-modified silicone), pigments, sensitizers, dispersants, antioxidants, fragrances, deodorants, stabilizers, etc. are added. May be.

  Component A of the present invention is a compound having at least one oxetane ring in the molecule and may be either a monomer or an oligomer. For example, oxetane compounds described in JP-A-8-85775 and JP-A-8-134405 can be used, and among them, compounds having one or two oxetane rings in one molecule are preferable. Examples of the compound having one oxetane ring in one molecule include 3-ethyl-3-[(phenoxy) methyl] oxetane, 3-ethyl-3- (hexyloxymethyl) oxetane, 3-ethyl-3- (2- Ethylhexyloxymethyl) oxetane, 3-ethyl-3- (hydroxymethyl) oxetane, 3-ethyl-3- (chloromethyl) oxetane, and the like. Examples of the compound having two oxetane rings in one molecule include 1,4-bis [(3-ethyl-3oxetanylmethoxy) methyl] benzene, bis {[1-ethyl (3-oxetanyl) methyl]} ether, and the like. Can be mentioned. Of these, 3-ethyl-3- (hydroxymethyl) oxetane and bis {[1-ethyl (3-oxetanyl) methyl] are particularly preferred from the viewpoint of coating processability and the curability of the coating layer. } Ether.

  As component B of the present invention, a known epoxy compound having at least one epoxy group in the molecule can be used. For example, an aliphatic epoxy compound, an alicyclic epoxy compound, or an aromatic epoxy compound can be used. Among these, from the viewpoint of high reaction rate, a compound having a glycidyl group or a compound having an epoxycyclohexane ring is preferable, and an epoxy compound having two or more epoxy groups is preferable. For example, examples of the aliphatic epoxy compound include propylene glycol glycidyl ether. Examples of the alicyclic epoxy compound include 3,4-epoxycyclohexylmethyl-3 ', 4'-epoxycyclohexanecarboxylate and bis- (3,4-epoxycyclohexyl) adipate. Examples of the aromatic epoxy compound include bisphenol A glycidyl ether, glycidyl ether condensate of bisphenol A, and epichlorohydrin modified products of novolac resin and cresol resin. Among these, 3,4-epoxycyclohexylmethyl-3 ', 4'-epoxycyclohexanecarboxylate is particularly preferable.

  Component A and Component B used in the resin composition of the present invention are resin composition adhesiveness, curability, coatability (flow characteristics), followability to shrink processing, etc. and cured resin layer (resin cured product layer) It is a component that bears the main characteristics such as toughness (such as scratch resistance and resistance to scratching), heat resistance, and chemical resistance. The total amount of component A and component B of the present invention is preferably from 30 to 95% by weight based on the entire resin composition (weight) from the viewpoint of applicability, curability and the like. Especially, when the resin composition of this invention is an adhesive agent for plastic films and a transparent coating agent, 60 to 95 weight% is preferable, More preferably, it is 70 to 90 weight%. Moreover, when the resin composition of this invention is printing ink containing a pigment, 30 to 90 weight% is preferable, More preferably, it is 40 to 80 weight%.

  The mixing ratio of component A and component B (component A: component B, weight ratio) in the resin composition of the present invention is preferably 2: 8 to 8: 2, and the resin composition of the present invention is particularly suitable for gravure printing and flexographic printing. Is preferably 3: 7 to 8: 2, more preferably 4: 6 to 7: 3. Among these, when the resin composition of the present invention is used as a printing ink, the blending ratio is preferably 5: 5 to 8: 2, more preferably 6: 4 to 7: 3. When the resin composition of the present invention is used as an adhesive for plastic films, the blending ratio is preferably 3: 7 to 7: 3, more preferably 4: 6 to 6: 4. If the amount of component A is larger than the above range, the starting speed of the curing reaction of the resin composition is slowed down, so that it takes time to cure, and productivity may be reduced, or it may be uncured in a normal curing process. is there. In addition, when the amount of component B is larger than the above range, the viscosity of the resin composition becomes so large that it becomes difficult to apply uniformly by a coating method such as gravure printing or flexographic printing, or there is a reaction to stop the curing reaction. It is likely to occur, resulting in a low molecular weight cured product, and the cured resin layer may be fragile.

  In the present invention, component A has an advantage that the growth reaction rate is high and the termination reaction hardly occurs in the curing reaction, so that a high molecular weight cured product is obtained and the toughness of the cured resin layer is improved. Since it is a viscosity, the coating property in gravure printing or flexographic printing is improved. On the other hand, since the initiation reaction is difficult to proceed, the curing process takes time and productivity is lowered, and there is a disadvantage that the curing does not proceed at a short curing time and the toughness of the cured resin layer is insufficient. On the other hand, Component B has the advantage that the start reaction is fast and the production rate is fast, but the termination reaction is likely to occur. Therefore, the cured product has a low molecular weight and the toughness of the resin cured product layer is insufficient. By mixing both of them in the above proportions, it is possible to obtain a resin composition having both productivity (curing speed), coating property (flow characteristics) and toughness of the cured product.

  Component C of the present invention is a thermoplastic resin having an acid value of 20 (mg-KOH / g-resin) or more. Component C is a component that improves the adhesion of the resin composition of the present invention and suppresses a decrease in adhesion to a film having low adhesion, such as a polyethylene film, and maintains the adhesion. Component C is not particularly limited as long as it is a thermoplastic resin satisfying the above acid value, but a vinyl resin containing a carboxyl group or an acid anhydride group (hereinafter referred to as a carboxyl group-containing vinyl resin) is preferably exemplified. .

  Examples of the carboxyl group-containing vinyl resin that can be used as Component C of the present invention include unsaturated carboxylic acids such as (meth) acrylic acid, crotonic acid, isocrotonic acid, maleic acid, maleic anhydride, itaconic acid, citraconic acid, and the like. Acid, styrene, α-methylstyrene, hydroxystyrene, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, dodecyl (Meth) acrylate, 2-ethylhexyl (meth) acrylate, hydroxymethyl (meth) acrylate, hydroxyethyl (meth) acrylate, glycidyl (meth) acrylate, benzyl (meth) acrylate, N, N-dimethylamino ester (Meth) acrylate, N- (meth) acryloylmorpholine, (meth) acrylonitrile, (meth) acrylamide, N-methylol (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-dimethylaminoethyl ( And copolymers with vinyl compounds such as (meth) acrylamide and vinyl acetate. Here, “(meth) acryl” means “acryl” and / or “methacryl”. Among these, a styrene-maleic anhydride copolymer and a carboxyl group-containing (meth) acrylic polymer are particularly preferable.

  The acid value (based on JIS K 5601-2-1) of Component C of the present invention is 20 (mg-KOH / g-resin) or more, preferably 20 to 550 (mg-KOH / g-resine), More preferably, it is 30-300 (mg-KOH / g-resin), More preferably, it is 40-280 (mg-KOH / g-resin). When the acid value is less than 20 (mg-KOH / g-resin), the effect of adding component C cannot be obtained, and sufficient adhesion to a film having low adhesion cannot be obtained. The upper limit of the acid value is not particularly limited depending on the amount of component C added, but if it exceeds 550 (mg-KOH / g-resin), the compatibility with components A, B, etc. In some cases, a sufficient effect cannot be obtained due to a decrease in dispersion. In addition, poor coating may occur.

  The acid value (based on JIS K 5601-2-1) of the mixture of Component A, Component B and Component C of the present invention is preferably 0.1 to 90 (mg-KOH / g-resin), more preferably 1 ~ 80 (mg-KOH / g-resin). When the acid value of the mixture is less than 0.1, sufficient adhesion to a film having low adhesion cannot be obtained. In addition, when the acid value of the mixture exceeds 90, the compatibility between the component C and the components A, B, etc. is reduced, resulting in poor dispersion and insufficient effects, or poor coating. May occur. In addition, the acid value of the said mixture can be controlled by the acid value of the component C, the addition amount of the components AC.

  As for the weight average molecular weight of the component C of this invention, 2000-100000 are preferable, More preferably, it is 3000-70000. When the molecular weight is less than 2,000, the component C may bleed out, and when the molecular weight exceeds 100,000, the viscosity of the resin composition increases and the coatability may decrease. .

  The addition amount of Component C of the present invention is preferably 0.1 to 30 parts by weight, more preferably 0.1 to 28 parts by weight, based on the total amount of Component A and Component B (100 parts by weight). is there. When the addition amount is less than 0.1 part by weight, the effect of improving the adhesiveness may not be obtained, and when it exceeds 30 parts by weight, the curability of the resin composition may be lowered.

  In the present invention, it is possible to obtain a certain degree of curing rate (productivity) and toughness by mixing only component A and component B, and show normal adhesive properties such as polyethylene terephthalate (PET). It can be used when used for plastic films. However, in systems containing lubricants such as erucic acid amide and stearic acid amide, antistatic agents, etc., the additive components in these films bleed on the surface and the like, which inhibits the cationic polymerization reaction (that is, curing inhibition) It is thought that it acts as a substance), but the curing rate (reaction rate) is extremely reduced. The component C of the present invention is used in addition to the components A and B to suppress the function of the curing inhibitor and to prevent the curing rate from decreasing even in a system in which these inhibitors exist. It is done. For this reason, the resin composition of the present invention can obtain good curability even in a film showing normal adhesiveness and improve adhesiveness and adhesion, but in particular, erucic acid amide, stearic acid amide, etc. Additive components that are regarded as curing inhibitors such as fatty acid amide lubricants and antistatic agents are effective for plastic films that exist on the film surface, and are particularly effective for polyolefin plastic films such as polyethylene Indicates.

  Examples of the curing inhibitor include candelilla wax, carnauba wax, rice wax, wax, jojoba oil, beeswax, lanolin, spermaceti, montan wax, ozokerite, ceresin, paraffin wax, microwax Kristan wax, petrolatum, Fischer-Trops wax, polyethylene wax, montan wax derivative, paraffin wax derivative, microcrystalline wax derivative, hardened castor oil, hardened castor oil derivative, 12-hydroxystearic acid, stearamide, bistearamide, Elca Acid amides, phthalic anhydride imides, waxes such as chlorinated hydrocarbons, antistatic agents with cationic and nonionic surfactants, talc, silica, calcium carbonate, titanium oxide Include additives such as alumina. Among them, those that are considered to have particularly strong curing inhibition include fatty acid amides such as stearic acid amide, bis stearic acid amide, and erucic acid amide, and antistatic agents based on cationic and nonionic surfactants.

  Silicone having at least one epoxy group in the molecule (epoxy-modified silicone) may be added to the resin composition of the present invention from the viewpoint of improving curing speed, solvent resistance, slipperiness, water repellency and the like. . The base silicone may be a polysiloxane having a siloxane bond as the main chain (for example, dimethyl silicone having all side chains and terminal methyl groups, and methylphenyl having a phenyl group in a part of the side chains. Silicone, methyl hydrogen silicone in which a part of the side chain is hydrogen, and the like). In addition, the epoxy group may be present at both ends or one end of the main chain, or may be present at the side chain, and examples thereof include compounds represented by the following structural formula.

In the formula, R ¹ , R ² and R ³ are hydrogen atoms or hydrocarbon groups, and may contain an oxygen atom, a nitrogen atom or a sulfur atom. A hydrogen atom, a methyl group, and a phenyl group are preferable, and a methyl group is particularly preferable. Further, m and n in the formula are integers of 1 or more. Furthermore, X ¹ and X ² in the formula are epoxy groups. For example, as shown in the following structural formula, the oxygen atom of the epoxy group does not contain a cyclic aliphatic skeleton (left figure: aliphatic epoxy group and Or an oxygen atom in which an oxygen atom of an epoxy group is formed including a cyclic aliphatic skeleton (right diagram: referred to as an alicyclic epoxy group).

R ⁴ and R ⁵ in the formula are a hydrogen atom or a hydrocarbon group, and may contain an oxygen atom, a nitrogen atom, or a sulfur atom. Further, for example, an epoxy-modified silicone compound described in JP-A-10-259239 can be used.

  Among these, those in which a part of the side chain of dimethyl silicone or at least one terminal group is an epoxy group are particularly preferable. Moreover, the functional group equivalent of an epoxy group in the silicone resin is preferably 300 to 5000, more preferably 400 to 4000, from the viewpoint of curability.

  When the epoxy-modified silicone is added, the content is preferably 0.1 to 20 parts by weight, more preferably 100 parts by weight based on the total amount of component A and component B, when coating by gravure and flexographic printing. Is 0.2 to 10 parts by weight, more preferably 0.3 to 5 parts by weight. When the content is less than 0.1 parts by weight, the effect of adding the epoxy-modified silicone is small, and the solvent resistance, slipping property, water repellency and the like may be lowered. Moreover, when it exceeds 20 weight part, the viscosity of a resin composition becomes high and it may become difficult to apply | coat uniformly by gravure and flexographic printing.

  A photopolymerization initiator is added to the resin composition of the present invention. Although it does not specifically limit as a photoinitiator of this invention, It is preferable to use a photocationic polymerization initiator. Although it does not specifically limit as said photocationic polymerization initiator, For example, well-known compounds, such as a diazonium salt, a diaryl iodonium salt, a triaryl sulfonium salt, a silanol / aluminum complex, a sulfonate ester, an imide sulfonate, can be used. Of these, diaryl iodonium salts and triarylsulfonium salts are particularly preferable from the viewpoints of reactivity and safety. Moreover, the addition amount of the photopolymerization initiator with respect to the resin composition of the present invention is not particularly limited, but is preferably 0.1 to 10% by weight, more preferably 0.5 to 7% by weight with respect to the entire resin composition. %, More preferably 1 to 5% by weight.

  When the resin composition of the present invention is used as a printing ink for plastic films, pigments, dyes and other additives can be added. In particular, it is preferable to contain a pigment. Organic, inorganic, and colored pigments can be used as pigments. White pigments such as titanium oxide (titanium dioxide), indigo pigments such as copper phthalocyanine blue, carbon black, aluminum flakes, and mica (mica) are selected according to the application. Can be used. In addition, extender pigments such as alumina, calcium carbonate, barium sulfate, silica, and acrylic beads can also be used as pigments for the purpose of adjusting gloss.

  Among these, when the resin composition of the present invention is used as a white printing ink, titanium oxide is preferably used as the pigment. As the titanium oxide, any of rutile type (tetragonal high temperature type), anatase type (tetragonal low temperature type), and brookite type (orthorhombic type) may be used. For example, titanium oxide particles manufactured by Ishihara Sangyo Co., Ltd. “Taipeke” is available. Moreover, the average particle diameter of the titanium oxide particles (in the case where an aggregate is formed, the particle diameter of the aggregate, so-called secondary particle diameter) is, for example, 0.01 to 1 μm, preferably 0.1 to 0.00. It is about 5 μm. If the average particle size is less than 0.01 μm, the dispersibility is poor, and if it exceeds 1 μm, the film surface becomes rough and the appearance tends to deteriorate.

  When the resin composition of the present invention is used as a printing ink for a plastic film, the pigment content can be arbitrarily designed depending on the type of pigment, the target color density, etc. About 0.1 to 70 weight% is preferable, and in the case of white printing ink, 20 to 60 weight% is more preferable from a viewpoint of concealability and coarse protrusion formation suppression, More preferably, it is 30 to 55 weight%.

  When using the resin composition of this invention as printing ink for plastic films, it is preferable to add a sensitizer as needed from a viewpoint of improving production efficiency. This is particularly effective when the titanium oxide pigment is used. In this case, the sensitizer can be selected from existing sensitizers in consideration of the type of active energy ray used. For example, (1) amine sensitizers such as amines containing nitrogen in the ring, such as aliphatic, aromatic amines, piperidine, (2) urea sensitizers such as allyl, o-tolylthiourea, (3) sodium Sulfur compound sensitizers such as diethyldithiophosphate, (4) anthracene sensitizers, (5) nitrile sensitizers such as N, N-disubstituted-p-aminobenzonitrile compounds, (6) tri -Phosphorus compound sensitizers such as n-butylphosphine, (7) Nitrogen compound sensitizers such as N-nitrosohydroxylamine derivatives and oxazolidine compounds, (8) Chlorine compound sensitizers such as carbon tetrachloride, etc. Sensitizers. Also in the above, in particular, anthracene sensitizers are preferred because of their strong sensitizing action. Of these, thioxanthone and 9,10-dibutoxyanthracene are preferably used. Moreover, it is although it does not specifically limit as content of a sensitizer, 0.1-10 weight% is preferable with respect to the whole resin composition, Most preferably, it is 0.3-5 weight%.

  The resin composition of the present invention may contain a lubricant as necessary. As the lubricant, known ones can be used, and are not particularly limited. For example, polyolefin wax such as polyethylene wax, fatty acid amide, fatty acid ester, paraffin wax, polytetrafluoroethylene (PTFE) wax, carnauba wax And various waxes such as fluorine-modified polyethylene wax. The addition amount of the lubricant is preferably 0.1 to 10% by weight with respect to the entire resin composition.

  The content of the solvent in the resin composition of the present invention is preferably 5% by weight or less, more preferably 1% by weight or less, and further substantially contains a solvent with respect to the entire resin composition. Most preferably not. The solvent here refers to, for example, organic solvents such as toluene, xylene, methyl ethyl ketone, ethyl acetate, methyl alcohol, ethyl alcohol, and water. In gravure and flexographic printing inks, coating properties and coating agents are used. It is usually used for the purpose of improving the compatibility and dispersibility of each component therein, and is removed by drying after coating. Since the resin composition of the present invention can exhibit excellent coating properties and dispersibility between components even without a solvent, the amount of the solvent can be extremely small (or not used), so that the solvent can be removed by a drying process or the like. In addition to being unnecessary, the speed and cost can be reduced, and the environmental load can be reduced.

  The viscosity (23 ° C.) of the resin composition of the present invention varies depending on the coating method used and is not particularly limited. For example, when the coating layer is formed by gravure printing, 100 to 2000 mPa · s is preferable, More preferably, it is 200-1000 mPa * s. When the viscosity exceeds 2000 mPa · s, the gravure printability may be lowered, and “decrease” or the like may occur, and the decorating property may be lowered. Further, when the viscosity is less than 100 mPa · s, the storage stability may be lowered. The viscosity of the resin composition can also be controlled by the blending ratio of oxetane and epoxy, thickener, thinning agent and the like. In the present specification, “viscosity” is JIS Z 8803 under the conditions of using a B-type viscometer (single cylindrical rotational viscometer) and a temperature of 23 ° C. and a rotational speed of a cylinder of 60 unless otherwise specified. The value measured according to.

  The resin composition of the present invention is preferably applied by gravure printing or flexographic printing from the viewpoints of cost, productivity, printing decoration and the like. Among these, a gravure printing method is particularly preferable.

  The resin composition of the present invention is used for application to a plastic film from the viewpoints of coating property, adhesiveness, and the like. In particular, it is preferably applied directly to the plastic film without any other layer. Among them, it is particularly preferably used as a coating agent such as printing ink, top coat and anchor coat from the viewpoint of toughness and adhesion, and as an adhesive for plastic film from the viewpoint of adhesiveness.

  When the resin composition of the present invention is used as a coating agent, the coating agent is a printing ink for imparting decorativeness, a transparent coating agent (sliding medium) for improving the slipperiness of the label surface, or a matte label. A matte coating agent (matte varnish). Since the coating agent comprising the resin composition of the present invention is excellent in coatability and curability, the process speed can be increased and the productivity is improved. In addition, the same coating agent can be used for a wide variety of plastic films because it exhibits excellent adhesion and adhesion even to difficult-to-adhere plastic films. From the viewpoint of Furthermore, since the cured resin layer (coating layer) obtained by curing the resin composition of the present invention is excellent in toughness, it is unlikely to be scraped during the process or distribution process.

  When the resin composition of the present invention is used as an adhesive for plastic films, the adhesive for plastic films is plastic films (for example, base film and sealant film), plastic film and metal foil, metal vapor deposited film, non-woven fabric, foam It is preferably used as an adhesive for dry lamination used for bonding with sheets, paper, and the like. It can also be used as an adhesive for bag making used for the center seal of shrink labels. Since the adhesive for plastic films comprising the resin composition of the present invention is excellent in coatability and curability, the process speed can be increased and the productivity is improved. In addition, the same adhesive can be used for a wide variety of plastic films because it exhibits excellent adhesion even to difficult-to-adhere plastic films, from the viewpoint of cost and process simplification. It is advantageous.

  The type of the plastic film to which the resin composition of the present invention is applied can be appropriately selected according to the required physical properties, application, cost, etc., and is not particularly limited. For example, polyester, polyolefin, polystyrene, Resins such as polyvinyl chloride, polyamide, aramid, polyimide, polyphenylene sulfide, and acrylic can be used. A polyester film and a polyolefin film are preferable. Among them, the resin composition of the present invention is preferably used for a plastic film containing a curing inhibitor, from the viewpoint of exhibiting excellent adhesive force even with a hardly adhesive film containing a curing inhibitor. When it is used for a polyolefin-based film in which properties are difficult to obtain, it is preferable because the most remarkable effect can be exhibited. Examples of the polyolefin include polypropylene, polyethylene, and cyclic polyolefin. These polyolefin films are added with fatty acid amides such as stearic acid amide and erucic acid amide, antistatic agents, anti-blocking agents such as silica, talc, clay, etc., depending on the application and the like. Although it may be distributed, the resin composition of the present invention exhibits excellent adhesion to such a surface.

  The plastic film may be a single-layer film or a laminated film in which a plurality of film layers are laminated according to required physical properties, applications, and the like. In the case of a laminated film, film layers made of different resins may be laminated. For example, it may be a three-layer laminated film composed of a central layer and a surface layer portion (inner layer, outer layer), a film in which the central layer is composed of a polyolefin resin or a polystyrene resin, and a surface layer is composed of a polyester resin. Moreover, you may use any of an unstretched film, a uniaxially oriented film, and a biaxially oriented film according to a required physical property, a use, etc. In particular, in the case of shrink label applications, as the plastic film, a shrink film is used, and a uniaxial or biaxially oriented film is often used. A film that is strongly oriented in the circumferential direction (substantially uniaxially stretched in the width direction) is generally used.

  Although the thickness of the said plastic film changes with uses and is not specifically limited, 10-200 micrometers is preferable, for example, in the case of a shrink label use, 20-80 micrometers is preferable, More preferably, it is 30-60 micrometers. Moreover, in the case of a dry laminate use, 10-130 micrometers is preferable, More preferably, it is 12-60 micrometers.

  When the resin composition of the present invention is applied to a plastic film, the thickness of the cured resin layer (coating layer thickness, adhesive layer thickness, etc.) varies depending on the application and is not particularly limited, but is 0.1 to 30 μm. Is preferable, and 0.2 to 20 μm is particularly preferable. When the thickness of the cured resin layer is less than 0.1 μm, it may be difficult to uniformly provide the cured resin layer. ”May occur, decorativeness may be impaired, and printing as designed may be difficult. Further, when the thickness of the cured resin layer exceeds 30 μm, a large amount of the resin composition is consumed, so that the cost is increased and it is difficult to apply uniformly, and the cured resin layer is fragile. It becomes easier to peel off. Especially, when the resin hardened | cured material layer of this invention is a white ink layer, 5-10 micrometers is preferable from a concealment viewpoint, and 1-8 micrometers is preferable in the case of another printing ink layer. In the case of a transparent coating layer, from the viewpoint of transparency, (0.2 to 5 μm is preferable. In the case of an adhesive layer for dry lamination, 0.2 to 20 μm is preferable. Since the thickness of the cured resin layer hardly changes before and after curing, the thickness is almost equal to the coating thickness of the resin composition.

  The film coated with the resin composition of the present invention is used for soft packaging materials such as plastic labels and pouches, for example. Among these, a plastic label is preferable.

  The above-mentioned resin composition of the present invention is preferably used for plastic label applications, particularly when used as a coating agent such as printing ink. Specifically, it can be used for stretch labels, shrink labels, stretch shrink labels, in-mold labels, tack labels, roll labels (wrap-type glued labels), heat-sensitive adhesive labels, and the like. Among these, from the viewpoint of the toughness of the resin composition of the present invention and the followability during processing, it is particularly preferably used as a stretch label, a stretch shrink label, and a shrink label.

  The plastic label of the present invention is obtained by applying the resin composition of the present invention to a plastic film, curing the active energy ray, and forming a cured resin layer composed of a cured product of the resin composition on the plastic film without passing through another layer. It is provided. The plastic label may have at least one cured resin layer of the present invention, and the cured resin layer may be provided on the inner surface or outer surface of the plastic film, or is sandwiched between the plastic film and the plastic film. It may be provided. Further, depending on the application, the cured resin layer may be provided on the entire surface of the plastic label, or may be provided only in a part such as in a strip shape in the longitudinal direction or the width direction. For example, when the resin composition of the present invention is used as a coating agent such as printing ink, the cured resin layer is also provided on the outermost layer of the label from the viewpoint of excellent scratch resistance and toughness. In particular, it is particularly preferable to be provided on the outer side of the label (on the side opposite to the side in contact with the adherend when attached to the adherend such as a container). Such a plastic label is preferable because the surface is hardly damaged and the decorativeness is not easily impaired when used in a manufacturing process, a conveying process or a market.

  In addition, the plastic label of the present invention may be provided with a printing layer different from the printing ink made of the resin composition of the present invention. In that case, the printing layer can be formed by a conventional printing method such as gravure printing or flexographic printing. The printing ink used for forming the printing layer is composed of, for example, a pigment, a binder resin, and a solvent. Examples of the binder resin include acrylic, urethane, polyamide, vinyl chloride-vinyl acetate copolymer, cellulose, and nitro. Common resins such as cellulose can be used. The thickness of the printing layer is not particularly limited and is, for example, about 0.1 to 10 μm.

  In addition, the plastic label of the present invention may be provided with other layers such as an anchor coat layer, a primer coat layer, a nonwoven fabric, and paper, which are different from the cured resin layer of the present invention, as necessary.

  The plastic label of the present invention is attached to a container and used as a labeled container. Such containers include, for example, soft drink bottles such as PET bottles, milk containers for home delivery, food containers such as seasonings, alcohol beverage bottles, pharmaceutical containers, containers for chemical products such as detergents and sprays, cups, etc. This includes noodle containers. Also, the material of the container includes plastic such as PET, glass, metal and the like. In particular, when used on labels for soft drink bottles and chemical containers that come into contact with chemicals that are susceptible to impact in vending machines, etc., the cured resin layer of the present invention is resistant to scratches and chemicals. Is preferable because it is remarkably exhibited. The adherend is not limited to a container.

  The resin composition of the present invention is preferably used for pouches, laminated films for laminated labels, and center seals for cylindrical labels, particularly when used as an adhesive. Specifically, it can be used as a laminate film obtained by dry laminating a plastic film with the same or different types of plastic film, metal deposited film, metal oxide deposited film, aluminum foil, nonwoven fabric, foamed sheet, paper, and the like. . Among these, from the viewpoint of adhesion of the resin composition of the present invention, it is particularly preferably used as a laminate for the same type or different types of plastic film or metal vapor deposited film with respect to the plastic film. The above laminate film has gas barrier properties, moisture resistance, impact resistance, pinhole resistance, light shielding properties, heat resistance, cold resistance, fragrance retention, sealing properties, easy opening properties, depending on the type of material to be laminated with the base film. It can be used for food packaging applications, sanitary goods, chemicals, electronic parts packaging, agriculture, civil engineering construction, industrial films, and the like.

  The laminate film is obtained by applying the resin composition of the present invention to the plastic film, pasting the material to be laminated, and then curing the active energy ray. The laminated film may have at least one cured resin layer of the present invention, and the cured resin layer is usually provided between a plastic film and a laminated material. The cured resin layer is generally provided on the entire surface of the laminate film, but the cured resin layer may be provided only on a part depending on the application.

  Further, the same film has both a coating layer using the resin composition of the present invention as a coating agent and an adhesive layer using the resin composition of the present invention as an adhesive. May be.

  The cured resin layer surface of the film provided with the cured resin layer of the present invention (for example, a plastic label) was rubbed 10 times back and forth with a cotton swab soaked with methyl ethyl ketone (referred to as MEK rubbing test). It is preferable that the physical layer does not peel off. In the MEK rubbing test, when the cured resin layer is peeled off, the resin composition layer of the present invention is easily peeled off when used, and the decorativeness may be lowered.

  The heat shrinkage rate (90 ° C., 10 seconds) of the plastic film used in the present invention is not particularly limited. For example, in the case of shrink label use, the longitudinal direction is −3 to 15 from the viewpoint of shrink workability. %, And the width direction is preferably 20 to 80%. In the case of soft packaging applications such as pouches, substantially non-shrinkage is preferred.

  Below, the resin composition of this invention and the manufacturing method of a plastic label are demonstrated. In addition, although the example of the cylindrical shrink label using the white printing ink containing a titanium oxide as a resin composition and the heat-shrinkable polyester film as a plastic film is shown here, a manufacturing method is not limited to this. Absent.

  In the following description, in the order of processes, the original film after stretching is referred to as “plastic film”, and the one provided with the cured resin layer of the present invention is referred to as “(long) plastic label”. Furthermore, in the mounting process to the container, the long plastic label that has been processed into a cylindrical shape while being long is referred to as a “long cylindrical plastic label”.

[Preparation of resin composition]
Component A used in the resin composition of the present invention can be produced according to a known method using oxetane alcohol and a halide (for example, xylene dichloride) produced from trimethylolpropane and dimethyl carbonate. In addition, as the component A, an existing oxetane compound may be used. For example, “Aron Oxetane OXT-101, 121, 211, 221, 212” manufactured by Toagosei Co., Ltd. is commercially available.

  As the component B used in the resin composition of the present invention, those synthesized by a general method such as synthesis from epichlorohydrin and bisphenol A can be used. For example, “Celoxide 2021” manufactured by Daicel Chemical Industries, Ltd. "Celoxide 2080", "Epolide GT400", "UVR6110" manufactured by Dow Chemical Co., Ltd., etc. are commercially available.

  Component C used in the resin composition of the present invention is prepared by manufacturing a predetermined monomer such as maleic anhydride, styrene, or an acrylic monomer according to a known polymerization method such as a solution polymerization method, a bulk polymerization method, or an emulsion polymerization method. However, from the viewpoint of ease of application to the film, for example, solution polymerization can be used. A main monomer component and copolymerization monomer component are dissolved and copolymerized in a predetermined amount of a solvent such as toluene, and a crosslinking agent and a plasticizer are added as necessary to obtain an acrylic resin polymer solution. Further, when the bulk polymerization method is used, a solvent-free low molecular weight polymer can be obtained in a short time by continuously bulk polymerizing the monomer component at a high temperature and a high pressure. In addition, as the component C, for example, an existing compound such as “SMA” manufactured by Elf Atchem Japan, “John Crill” manufactured by Johnson Polymer may be used.

  Next, the resin composition of this invention is manufactured by mixing the obtained component A, component B, component C, and photopolymerization initiator. Moreover, when using additives, such as a pigment, it mixes simultaneously. For mixing, a mixer such as a butterfly mixer, a planetary mixer, a pony mixer, a dissolver, and a tank mixer, a mill such as a roll mill, a sand mill, a ball mill, a bead mill, and a line mill, and a kneader are used. The mixing temperature during mixing is preferably 15 to 30 ° C., and the mixing time (residence time) is preferably 10 to 120 minutes. The obtained resin composition may be used after being filtered, if necessary.

[Production of plastic film]
The plastic film of the present invention can be produced by a method such as melt film formation or solution film formation, or a polyester film, polystyrene film, polyolefin film or the like sold in the market can be used.

  For example, when producing a polyester film using the melt film-forming method, it is as follows.

  The film material is polymerized using known techniques. For example, polyester is obtained by using a process in which terephthalic acid and ethylene glycol are used as raw materials, a low molecular weight polyethylene terephthalate is obtained by a direct ester reaction, and a polymer is obtained by a polycondensation reaction using antimony trioxide as a catalyst. You may copolymerize 1, 4- cyclohexane dimethanol etc. as needed.

  The film raw material obtained above is extruded from a T die using a single or twin screw extruder to produce an unstretched film. At this time, by using a coextrusion method or the like, an unstretched film laminated in various layers can be obtained.

  Depending on the application, the unstretched film is further stretched to produce a plastic film. The stretching may be biaxial stretching in the longitudinal direction (longitudinal direction; MD direction) and width direction (transverse direction; TD direction), or may be uniaxial stretching in the longitudinal direction or the width direction. The stretching method may be any of a roll method, a tenter method, and a tube method. For example, in the case of a plastic film for a shrink label, the stretching treatment depends on the glass transition temperature (Tg) of the polymer to about Tg + 50 ° C. In many cases, the film is stretched by about 0.01 to 3 times, preferably about 1.05 to 1.5 times, and then stretched by about 3 to 10 times, preferably about 4 to 6 times in the width direction.

  The surface of the plastic film of the present invention may be subjected to a conventional surface treatment such as corona discharge treatment or primer treatment, if necessary.

[Application and curing of resin composition]
The resin composition is applied to the obtained plastic film to form a resin composition layer (uncured). The coating method varies depending on the application, and may be provided by in-line coating that is applied during the plastic film manufacturing process (for example, after unstretched or longitudinally uniaxially stretched), or offline coating that is performed after film formation. Although not particularly limited, off-line coating is preferable from the viewpoint of productivity and workability including curing treatment, and gravure printing or flexographic printing is most preferable.

Next, the resin composition layer is cured. Curing is preferably performed in a printing step and a series of steps. Curing is performed by active energy ray curing using an ultraviolet (UV) lamp or the like from the viewpoint of preventing deformation troubles due to heat shrinkage of the plastic film. In the case of active energy ray curing, the active energy ray to be irradiated varies depending on the composition of the resin composition and is not particularly limited. However, from the viewpoint of curability, the wavelength is preferably 300 to 460 nm, and the irradiation intensity is 20 mJ / cm. ^{2 to} 1000 mJ / cm ² and the irradiation time is preferably 0.1 to 3 seconds.

  The above label is slit into a predetermined width and wound into a roll shape, and a plastic label is obtained as a plurality of roll-like objects.

In addition, although an example of the process which mounts the obtained plastic label to a container is shown below, a manufacturing method is not limited to this.
[Processing of long plastic labels]
Next, while feeding out one of the rolls, the long plastic film is formed into a cylindrical shape so that the width direction is the circumferential direction. Specifically, a long shrink label is formed into a cylindrical shape, and a solvent or adhesive (hereinafter referred to as “THF”) having a width of about 2 to 4 mm in the longitudinal direction on one side edge of the label. Solvent etc.) is applied to the inner surface, rolled up into a cylindrical shape, and the applied portion of the solvent etc. is superposed at a position of 5 to 10 mm from the other side edge and adhered to the outer surface (center seal) To obtain a long cylindrical plastic label. Moreover, when performing the said center seal | sticker, you may use the adhesive agent which consists of a resin composition of this invention as said adhesive agent.

  In the case where a perforation for label excision is provided, a perforation having a predetermined length and pitch is formed in the longitudinal direction. The perforation can be applied by a conventional method (for example, a method of pressing a disk-shaped blade having a cut portion and a non-cut portion repeatedly formed around it, a method using a laser, or the like). The process stage for perforating can be appropriately selected after the printing process and before and after the cylindrical processing process.

[Container with label]
Finally, after cutting the long cylindrical plastic label obtained above, it is attached to a predetermined container, and the label is contracted by heat treatment, and a container with a label is prepared by closely contacting the container. The above long cylindrical plastic label is supplied to an automatic label mounting device (shrink labeler), cut to the required length, and then externally fitted into a container filled with the contents, and a hot air tunnel or steam tunnel at a predetermined temperature is attached. Passed or heated with radiant heat such as infrared rays to cause heat shrinkage and adhere to the container to obtain a labeled container. Examples of the heat treatment include treatment with steam at 80 to 100 ° C. (passing through a heating tunnel filled with steam and steam).

[Methods for measuring physical properties and methods for evaluating effects]

(1) Acid value The acid value of component C used in Examples and Comparative Examples, and the acid value of a mixture of three components of components A, B, and C were measured according to JIS K 5601-2-1. .

(2) Gravure printability The gravure printing was given to the polyolefin-type film ("FL1" by Gunze Co., Ltd., thickness: 50 micrometers) with the resin composition obtained by the Example and the comparative example on the following printing conditions.
Equipment: Desktop gravure printing machine "GRAVO PROOF MINI" made by Nissho Gravure Co., Ltd.
Gravure plate: 175 lines, plate depth 30 μm
Process speed: 50 m / min The printing state was observed, and the case where printing was carried out according to the plate surface was judged as good (◯), and the case where printing was not carried out according to the plate surface was judged as poor gravure printing property (×).

(3) Curability (Surface tackiness)
Touch the resin cured product layer of the plastic label immediately after the curing treatment in Examples and Comparative Examples with your finger and visually observe whether the finger is inked. When it was good (◯) and the finger was inked, it was judged that the curability was poor (x).

(4) Adhesiveness (tape peeling test)
The test was conducted in accordance with JIS K 5600, except that the cross cut of the grid was not made. Nichiban tape (width 18 mm) was applied to the surface of the resin label side of the plastic label obtained in the examples and comparative examples, peeled in the direction of 90 degrees, and the remaining area of the resin layer in the region of 5 mm × 5 mm Observed and judged according to the following criteria.
95% or more: Excellent adhesion (◎)
90% or more and less than 95%: Good adhesion (○)
80% or more and less than 90%: Adhesiveness is slightly poor but usable level (△)
Less than 80%: poor adhesion (×)

(5) Chemical resistance (MEK rubbing resistance test)
After rubbing the surface of the cured resin layer of the plastic label with a cotton swab soaked with methyl ethyl ketone, rubbing 10 times, and visually observing the surface, if the ink is not peeled off, good chemical resistance (○), When the ink was peeled off, it was judged that the chemical resistance was poor (x).

(6) Scratch resistance A sample piece having a length of 100 mm and a width of 100 mm was collected from the plastic label obtained in the example. Hold both ends of the sample piece with both hands and hold it 10 times. When the remaining area of the cured resin layer on the surface on which the cured resin layer is provided is visually observed, if the remaining area is 90% or more, the resistance to cracking is good (O). It was judged as poor scouring (x).

(7) Scratch resistance (scratch test)
A sample piece having a length of 100 mm and a width of 100 mm was collected from the plastic label obtained in the example. Place the sample on a smooth table, observe the surface after rubbing the surface of the cured resin layer side 10 times at the back of the nail of the hand (20 mm in the longitudinal direction), and judge according to the following criteria did.
The cured resin layer is not peeled off at all. : Good scratch resistance (○)
Partial peeling is observed in the cured resin layer. : Scratch resistance is slightly poor but usable level (△)
The cured resin layer is significantly peeled off. : Scratch resistance failure (×)

(8) Shrinkability The plastic label is removed from the labeled container obtained in the example, and the resin cured material layer is peeled off, cracked (large cracks), and markedly whitened due to fine cracks. Moreover, the presence or absence of transfer of the resin cured material layer to the container side was observed. Each container was observed for 10 containers, and when the above-mentioned cracks were not observed, it was judged that the shrinkability was good (◯), and when even one crack was observed, the shrinkability was poor (x).

(9) Suitability for dry lamination After coating the resin compositions obtained in Examples 1 to 3, 5 to 9 and Comparative Example 3 on a base film using a bar coater (count: # 5), It bonded together with the same base film of 1 sheet. The obtained laminated film is irradiated with light using a polar ultraviolet irradiation device (GS Yuasa Lighting Co., Ltd., trade name “4 kW UV irradiation device”) at a conveyor speed of 50 m / min and 120 W / cm. Samples were prepared using the following three types of base films.
Using a tensile tester (Shimadzu Autograph AG-IS, manufactured by Shimadzu Corporation), a T-type peel test (test speed 50 m / min, sample width 15 mm) is performed in accordance with JIS K 6854-3. The peel adhesion strength (N / 15 mm) was measured.
When all three types of substrate films have a peel adhesive strength of 8 N / 15 mm or more, it is judged that the dry laminating property is good (◯), and the case where there is less than 8 N / 15 mm is judged as poor dry laminating property (×). did.
[Base film]
Polyethylene film (“FJU2K” manufactured by Ube Film Co., Ltd.) Thickness: 90 μm
Polyester film (“S7042” manufactured by Toyobo Co., Ltd.) Thickness: 50 μm
Polyolefin film (Gunze Co., Ltd. “FL1”) Thickness: 50 μm

(10) Film layer thickness, coating layer thickness The film thickness was measured using a stylus type thickness gauge. The coating layer thickness was measured using a three-dimensional microscope (Keyence Co., Ltd. VK8510) for the level difference between the portion where the coating layer was provided (application surface) and the portion where the coating layer was not provided (non-application surface).

(11) Plastic film heat shrinkage (90 ° C)
A rectangular sample piece having a length of 200 mm (mark interval 150 mm) and a width of 10 mm in the measurement direction (longitudinal direction or width direction) was produced from the plastic film.
The sample piece was heat-treated for 10 seconds (under no load) in 90 ° C. warm water, the difference between the marked lines before and after the heat treatment was read, and the heat shrinkage rate was calculated by the following formula.
Thermal shrinkage (%) = (L ₀ −L ₁ ) / L ₀ × 100
L ₀ : Marking interval before heat treatment L ₁ : Marking interval after heat treatment (12) Viscosity V-type viscometer (single cylindrical rotational viscometer) manufactured by Toki Sangyo Co., Ltd. The measurement was performed in accordance with JIS Z 8803 under the conditions of ° C. and the number of rotations of the cylinder of 60.

EXAMPLES Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.
Example 1
As component A, 3-ethyl-3-hydroxymethyloxetane (manufactured by Toagosei Co., Ltd., trade name “Aron Oxetane OXT-101”) and as component B, an epoxy monomer (manufactured by Dow Chemical Co., Ltd., trade name “UVR-”) 6110 "), styrene-maleic anhydride copolymer (manufactured by Elf Atchem Japan Ltd., trade name" SMA resin 1000P ", acid value 480 (mg-KOH / g-resin)), photopolymerization as component C The initiator (manufactured by Dow Chemical Co., Ltd., trade name “UVI-6992”) and sensitizer (manufactured by Nippon Kayaku Co., Ltd., “KAYACURE CTX”) were added according to the amount (parts by weight) shown in Table 1. The mixture was mixed and dispersed and mixed for 30 minutes with a disperser to obtain a resin composition. No solvent was used.
Using the obtained gravure printing machine (manufactured by Nissho Gravure Co., Ltd., trade name “GRAVO PROOF MINI”) and a gravure plate with a 175 line and a plate depth of 30 μm, a polyolefin-based shrink film (Gunze ( Gravure printing was performed on one side of “FL1” manufactured by Co., Ltd., with a thickness of 50 μm, at a process speed of 50 m / min, and the gravure printability was evaluated.
Similarly to the above, after applying a resin composition to a polyolefin film, an electroded lamp type ultraviolet irradiation device (manufactured by GS Yuasa Lighting Co., Ltd., trade name “4 kW (160 W / cm) UV irradiation device”) The resulting product was irradiated with light at a conveyor speed of 50 m / min and 120 W / cm to obtain a plastic label, and the coating layer had a thickness of 3 μm. Adhesion was evaluated.
Subsequently, the obtained plastic label is formed in a cylindrical shape so that the cured resin layer is on the inner surface, and the length in the circumferential direction is adjusted so that it is thermally contracted by 20% on the body of the PET bottle. Then, both ends were welded to obtain a cylindrical plastic label. Further, the container was attached to a 500 ml PET bottle, and the label was shrunk by a steam tunnel having an atmospheric temperature of 90 ° C. to obtain a labeled container.
As shown in Table 1, the obtained resin composition was excellent in gravure printability, and had good curability and adhesiveness. Further, the obtained labeled container had an excellent finish.
In addition, about Example 1, the plastic label which used the polyester-type shrink film (Toyobo Co., Ltd. product "S7042", thickness 50 micrometers) instead of the polyolefin-type film as a shrink film was also produced and evaluated. As a result, the resin composition of Example 1 exhibited excellent gravure printability, curability and adhesiveness even for polyester films.

Examples 2-9
As shown in Table 1, the type of component C and the amount of each component were changed, and in the same manner as in Example 1, a resin composition, a plastic label, and a labeled container were obtained. In Example 4, a pigment (titanium oxide: manufactured by Ishihara Sangyo Co., Ltd., trade name “Taipeke PF736”) was added to the resin composition to obtain a white ink.
As shown in Table 1, the obtained resin composition was excellent in gravure printability, and had good curability and adhesiveness. Further, the obtained labeled container had an excellent finish.

  The plastic labels obtained in Examples 1 to 9 were further evaluated for chemical resistance, resistance to scratching, scratch resistance, and shrinkability according to the methods described above. As a result, all of these plastic labels were excellent in chemical resistance, resistance to scratching, scratch resistance, and shrinkability (◯).

Comparative Example 1
As shown in Table 1, a resin composition was obtained in the same manner as in Example 1 except that component A was not used and the amounts of components B and C were changed.
The obtained resin composition had a high viscosity, was inferior in applicability, and “grazing” occurred when gravure printing was performed. Moreover, curability and adhesiveness were also inferior.

Comparative Example 2
As shown in Table 1, a resin composition was obtained in the same manner as in Example 1 except that component B was not used and the amounts of components A and C were changed.
The obtained resin composition had low curability and poor productivity. Moreover, it was inferior to adhesiveness.

Comparative Example 3
As shown in Table 1, a resin composition was obtained in the same manner as in Example 1 except that Component C was not used.
The obtained resin composition satisfied the standards for gravure printability and curability, but had poor adhesion.

  In addition, about the resin composition obtained in Examples 1-3, 5-9, and the comparative example 3, according to the method of the said evaluation method (9), a laminate film is produced and dry laminate suitability evaluation is performed. It was. As a result, all the resin compositions obtained in the examples had good dry lamination suitability (◯). However, the resin composition of Comparative Example 3 was inferior in adhesiveness to (polyolefin-based film) and had poor dry laminate suitability (x).

Claims (10)

  A resin composition comprising an oxetane compound, an epoxy compound, and a thermoplastic resin having an acid value of 20 (mg-KOH / g-resin) or more, comprising a three-component mixture of an oxetane compound, an epoxy compound, and a thermoplastic resin An active energy ray-curable resin composition for plastic film coating, wherein the acid value is 0.1 to 90 (mg-KOH / g-resin).   The plastic film according to claim 1, wherein the thermoplastic resin having an acid value of 20 (mg-KOH / g-resin) or more is a thermoplastic resin having an acid value of 20 to 550 (mg-KOH / g-resin). Active energy ray-curable resin composition for coating.   The weight ratio of the oxetane compound and the epoxy compound is 2: 8 to 8: 2, and the added amount of the thermoplastic resin is 0.1 to 30 parts by weight with respect to 100 parts by weight of the total amount of the oxetane compound and the epoxy compound. The active energy ray-curable resin composition for plastic film coating according to claim 1 or 2.   The active energy ray-curable resin composition for plastic film coating according to any one of claims 1 to 3, wherein the thermoplastic resin is a styrene / maleic anhydride copolymer or a carboxyl group-containing (meth) acrylic polymer. object.   The active energy ray-curable resin composition for plastic film coating according to any one of claims 1 to 4, which is for gravure printing or flexographic printing.   6. The active energy ray-curable resin composition for plastic film coating according to claim 1, wherein the plastic film is a polyolefin film.   The adhesive for plastic films which consists of an active energy ray curable resin composition for plastic film coating in any one of Claims 1-6.   The printing ink for plastic films formed by adding a sensitizer and a pigment to the active energy ray-curable resin composition for plastic film coating according to any one of claims 1 to 6.   A plastic label formed by coating the plastic film with the active energy ray-curable resin composition for plastic film coating according to any one of claims 1 to 8, the adhesive for plastic film, or the printing ink for plastic film. .   The plastic label according to claim 9, wherein the plastic film is a shrink film.