JP5495040B2 - Undercoat agent for plastic with inorganic thin film, plastic film with inorganic thin film, decorative film for in-mold molding, and decorative film for insert molding - Google Patents

Description

  The present invention relates to an undercoat agent used between an inorganic thin film layer such as an aluminum metal layer or a silicon oxide layer and a plastic substrate, a plastic film with an inorganic thin film obtained using the undercoat agent, and the inorganic The present invention relates to a decorative film for in-mold molding using a plastic film with a thin film as a member, and a decorative film for insert molding.

  The plastic with an inorganic thin film generally refers to an inorganic thin film made of a metal such as aluminum or a metal oxide such as silicon oxide formed on the surface of a plastic molded body or plastic film. Depending on the thickness of the thin film, etc., it is used in various applications such as bottles, caps, gas barrier films, conductive sheets, film capacitors, and display labels.

  Also, among plastics with inorganic thin films, aluminum-deposited plastic films with an aluminum layer thickness of only a few tens of nanometers have traditionally been used as decorative film members. In recent years, for example, it has been used for housings of various electronic products such as mobile phones, audio products, and personal computers.

  When manufacturing these plastics with an inorganic thin film, an undercoat agent mainly composed of various polymers is applied in advance to the surface of the plastic substrate, and a metal is deposited on the flexible undercoat layer. The method is taken. This is because it is difficult to ensure the adhesion between the inorganic thin film layer and the plastic substrate and the smoothness of the inorganic thin film because fine irregularities and impurities (plastic additives, etc.) are usually present on the surface of the plastic. is there.

  As such an undercoat agent, the present applicant has already proposed an acrylic copolymer having a carboxylate anion group combined with a polyaziridine compound as a crosslinking agent (Japanese Patent Application No. 2010-41532). Thus, the conventional undercoat agent is generally a two-component type in which various curing agents are combined with a high molecular weight polymer as a main component (see Patent Documents 1 to 3). However, some conventional undercoat agents do not have sufficient performance.

JP 2004-238403 A JP 2005-271467 A JP 2006-116703 A

  The present invention provides a novel undercoat agent that not only has excellent adhesion to an inorganic thin film and a plastic substrate, but can form a highly smooth inorganic thin film surface and does not use a polymer as a film forming component. Is an issue.

  As a result of intensive studies, the present inventor has found that the above-mentioned problems can be solved by using a polyaziridine derivative that has been conventionally used exclusively as a crosslinking agent as a film-forming component.

That is, the present invention provides a polyfunctional aziridine derivative (A) as a film-forming component having at least three aziridinyl groups represented by the following formula (1) in the molecule, and the acid catalyst is ammonia and / or a tertiary amine. containing those neutralized aziridinyl MotoHiraki ring catalyst (B) and solvent (C), and polymers having a functional group reactive with an aziridinyl group represented by the following formula (1) in the molecule ( D) an undercoat agent for plastic with an inorganic thin film that does not contain as a film-forming component; a plastic film, a layer made of the undercoat agent, and a plastic film with an inorganic thin film having a layer made of an inorganic thin film; the plastic film with an inorganic thin film Decorative film for in-mold molding using as a member; Insert molding decoration using the plastic film with inorganic thin film as a member Irumu relates.

  The undercoat agent of the present invention uses a predetermined low molecular weight polyfunctional aziridine derivative as a film-forming component, and differs from the conventional two-component type in that main agents such as acrylic resin, polyurethane resin, and polyester resin are used. do not need.

  Moreover, according to the undercoat agent of this invention, the inorganic thin film excellent in smoothness can be formed on a plastic base material. In particular, when the inorganic thin film is a metal thin film such as aluminum, an inorganic thin film having excellent gloss can be obtained. Moreover, since the undercoat layer made of the undercoat agent has good adhesion to the inorganic thin film layer, peeling of the inorganic thin film is reduced when handling the plastic with the inorganic thin film.

  In addition, the plastic with an inorganic thin film using the undercoat agent has a good appearance because a whitening phenomenon (clouding, blurring, etc.) and interference fringes hardly occur in the inorganic thin film even under a high temperature environment. Furthermore, the plastic with an inorganic thin film has an unexpected effect that no whitening phenomenon, interference fringes, and cracks occur in the processed part even when subjected to molding at a high temperature.

  Therefore, the undercoat agent is suitable as a member for packaging containers such as bottles, caps, and retort packs, gas barrier films, conductive sheets, film capacitors, display labels, and decorative films. Particularly in the case of an aluminum vapor-deposited plastic film, since it has good whitening resistance, interference fringe resistance, and crack resistance, a decorative film for in-mold molding or insert molding that is molded at a high temperature is used. Suitable for manufacturing parts.

The undercoat agent of the present invention comprises a polyfunctional aziridine derivative (A) (hereinafter referred to as component (A)) as a film-forming component having at least three aziridinyl groups represented by the following formula (1) in the molecule, aziridinyl It contains a group-opening catalyst (B) (hereinafter referred to as “component (B)”) and a solvent (C) (hereinafter referred to as “component (C)”) as main components.

(In formula (1), R ¹ and R ² each represent hydrogen or an alkyl group having 1 to 6 carbon atoms.)

  The component (A) is a component that forms a film by the ring opening of the aziridinyl group represented by the formula (1) by the action of the component (B) and self-polymerization (polymerization). (US Pat. No. 4,382,135, Japanese Unexamined Patent Publication No. 2003-104970, Japanese Unexamined Patent Publication No. 2009-256623, etc.) can be used without particular limitation.

  As the component (A), in consideration of the balance of film adhesion, smoothness, whitening resistance, interference fringe resistance, crack resistance, and other performances (hereinafter sometimes simply referred to as film performance), Trifunctional aziridine compounds and / or tetrafunctional aziridine compounds are preferred.

  As the trifunctional aziridine compound, those represented by the following general formula (2) are preferable because they are easily available.

(In the formula (2), X represents hydrogen, an alkyl group, or .R ¹ and ^{R 2} are each hydrogen or an alkyl group having 1 to 6 carbon atoms represents a alkylol group having 1 to 3 carbon atoms from 1 to 6 carbon atoms R ³ represents hydrogen or a methyl group.)

  Examples of the compound represented by the formula (2) include glycerol-tris (1-aziridinylpropionate), glycerol-tris [2-propyl- (1-aziridinyl)] propionate, glycerol-tris. [2,3-dimethyl- (1-aziridinyl)] propionate, trimethylolpropane-tris (1-aziridinylpropionate), trimethylolpropane-tris [2-hexyl- (1-aziridinyl)] Propionate, trimethylolpropane-tris [2,3-dihexyl- (1-aziridinyl)] propionate, tetramethylolmethane-tris (1-aziridinylpropionate), tetramethylolmethane-tris [2 -Hexyl- (1-aziridinyl)] propionate, tetramethylolmethaneate The [2,3-dihexyl - (1-aziridinyl)] Puropione - DOO and the like.

  As the tetrafunctional aziridine compound, for example, a compound represented by the following general formula (3) is preferable.

(In formula (3), R ¹ and R ² each represent hydrogen or an alkyl group having 1 to 6 carbon atoms. R ³ represents hydrogen or a methyl group.)

  Examples of the compound represented by the formula (3) include pentaerythritol-tetra (1-aziridinylpropionate), pentaerythritol-tetra [2-hexyl- (1-aziridinyl)] propionate, penta And erythritol-tetra [2,3-dihexyl- (1-aziridinyl)] propionate.

  As the other component (A), other tetrafunctional aziridines such as tetraaziridinyl metaxylenediamine and tetraaziridinylmethylparaxylenediamine, and the hexafunctional described in Japanese Patent Application Laid-Open No. 2003-104970 are available. Examples include aziridine compounds.

  If necessary, monofunctional aziridine compounds such as 2-methylaziridine, 2-ethylaziridine, 2-phenylaziridine, and bifunctional aziridine compounds such as neopentyl glycol di (β-aziridinylpropionate) Can be used together.

The component (B) is obtained by neutralizing an acid catalyst with ammonia and / or a tertiary amine. As the acid catalyst, various known catalysts can be used without particular limitation as long as they can open the aziridinyl group of the component (A). Specific examples include acid catalysts such as p-toluenesulfonic acid, hydrochloric acid, bromic acid, iodic acid, fluoric acid, fluorosulfonic acid, sulfuric acid, phosphoric acid, and diaryl iodonium salts, triarylsulfonium salts, diarylphosphonium salts, and the like. It is done. Of these, p-toluenesulfonic acid is particularly preferable because it is easy to handle .

Among the neutralizing agent as the tertiary amines, trimethylamine and triethylamine.

  Examples of the component (C) include water; alcohols such as methanol, ethanol, n-propanol, isopropanol, butanol, ethylene glycol, diethylene glycol, ethylene glycol monoethyl ether, and ethylene glycol monopropyl ether; lower grades such as acetone and methyl ethyl ketone. Ketones; aromatic hydrocarbons such as toluene and benzene; ethyl acetate, chloroform, dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone and the like. Among these, considering the balance of the film performance, alcohols having about 1 to 4 carbon atoms (particularly methanol, ethanol, isopropyl alcohol, ethylene glycol) and water are preferable.

In addition, as described above, the undercoat agent of the present invention generally uses the component (A) used as a crosslinking agent to be combined with various high molecular weight polymers, as the film forming component itself. (A) Polymer having a crosslinking agent as a component (also referred to as a synthetic resin or a synthetic polymer), that is, a polymer having a functional group that reacts with the aziridinyl group represented by the formula (1) in the molecule (D) ( Hereinafter, the component (D) is not contained as a film-forming component. Examples of the component (D) include polyurethane having a carboxyl group or a carboxylate anion group, an acrylic homopolymer, an acrylic copolymer (Japanese Patent Application No. 2010-41532). Etc.), polyester and the like. The number average molecular weight of the polymer is usually about 1500 to 50000, specifically about 3500 to 50000.

  Although the usage-amount of each component in the undercoat agent of this invention is not specifically limited, Usually, (B) component is about 1-10 weight part (preferably 3-8 weight part with respect to 100 weight part of (A) component. ), (C) component is about 50 to 900 parts by weight (preferably 100 to 500 parts by weight).

  Moreover, it is preferable to use a basic compound normally in the quantity which can make pH of an undercoat agent into about 4-12.

The undercoat agent of the present invention may contain additives such as an antifoaming agent, an antiskid agent, an antiseptic, a rust inhibitor, a pH adjuster, an antioxidant, a pigment, a dye, and a lubricant as necessary. Good. Moreover, you may include additives, such as colloidal silica and a filler. The amount of these used is usually about 0 to 10% by weight.

  The undercoat agent of the present invention can be obtained by mixing the components (A) to (C) by various known methods. Specifically, a method of mixing all the components at once, and a method of adding and mixing the component (A) to a solution obtained by mixing the component (C), the component (B) and the neutralizing agent can be mentioned. The solid content weight of the undercoat agent is usually about 5 to 50% by weight in consideration of practical convenience.

  Examples of the plastic with an inorganic thin film of the present invention include a plastic structure with an inorganic thin film and a plastic film with an inorganic thin film, depending on the shape of the substrate.

  The shape of the plastic base material forming the plastic structure with an inorganic thin film is not particularly limited, and may be, for example, spherical, cylindrical, cylindrical, rectangular parallelepiped, or plate-like, and may have irregularities and curved surfaces.

  The said plastic film with an inorganic thin film has a layer which consists of a plastic film, the layer which consists of the said undercoat agent, and an inorganic thin film.

  Examples of the plastic substrate include polyester (such as PET), polyvinyl chloride, polyamide, polyimide, polycarbonate, ABS, polyethylene, and polypropylene. Among these, polyester is preferable in consideration of adhesion with the undercoat layer.

  Examples of the seed forming the inorganic thin film include metals such as aluminum, gold, silver, copper, palladium, and tin, and metal oxides such as silicon oxide, aluminum oxide, tin oxide, indium tin oxide, and titanium oxide. Among these, aluminum is preferable in consideration of adhesion to the undercoat layer, smoothness, and the like.

The plastic with an inorganic thin film of the present invention is (1) various known methods (dip, spray, roll coater, reverse roll coater, gravure coater, knife coater, bar coater, etc.) on the plastic film substrate. ), And after forming an undercoat layer by heating at about 80 to 185 ° C. for about 10 seconds to 5 minutes, (2) various known thin film forming methods (vacuum heat) are applied to the undercoat surface. It can be obtained by vapor-depositing the inorganic thin film species by vapor deposition, sputtering, chemical vapor phase reaction or the like. Although the coating amount of an undercoat agent is not specifically limited, Usually, it is about 0.01-10 g / m < ² > as dry solid content. The thickness of the inorganic thin film layer is usually about 5 to 800 nm.

  In the plastic film with an inorganic thin film of the present invention, another functional layer may be adjacent to each of the plastic film, the undercoat layer, and the inorganic thin film layer depending on the application. For example, a release layer, a hard coat layer, an anchor layer for a hard coat layer, a pattern ink layer, and the like may be present between the plastic film and the undercoat layer. An adhesive layer may be present on the inorganic thin film layer.

  Among the plastic films with an inorganic thin film of the present invention, the polyester film, the undercoat layer, and the plastic film with an aluminum thin film having an aluminum layer of about 5 to 50 nm have particularly good whitening resistance and crack resistance. It is suitable as a decorative film for molding and a decorative film for insert molding.

  Hereinafter, the present invention will be described in more detail through production examples, examples, and comparative examples, but the present invention is not limited to these examples. In the examples, “%” and “parts” are based on parts by weight.

Synthesis Example 1 (Manufacture of acrylic resin as film forming component)
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen introduction tube, 215.4 parts of methyl methacrylate, 23.9 parts of acrylic acid, 2,2′-azobisisobutyronitrile 1 2 parts and 398 parts of isopropyl alcohol were charged, and kept at 80 ° C. for 5 hours under a nitrogen gas stream. Further, 2.4 parts of 2,2′-azobisisobutyronitrile was charged, and the reaction system was further kept at the same temperature for 3 hours. Next, 140.7 parts of isopropyl alcohol, 385.3 parts of water, and 33.5 parts of triethylamine were charged, and a solution of an acrylic copolymer having a number average molecular weight of 30000 and a carboxylate anion group content of 1.4 mmol / g (nonvolatile content) : 20%).

Synthesis Example 2 (Production of polyurethane resin as a film forming component)
In a four-necked flask similar to Synthesis Example 1, 362.3 parts of a commercially available polycarbonate diol (product name “Nippolan 980R”, number average molecular weight 2000, manufactured by Nippon Polyurethane Industry Co., Ltd.), 151.4 parts of isophorone diisocyanate, 2 , 2-dimethylolpropionic acid 36.3 parts and methylethylketone 550 parts were charged, and urethanation reaction was carried out at 80 ° C. for 10 hours to obtain 1100 parts of an isocyanate group-terminated urethane prepolymer. The composition was then stirred into a chain extender solution (triethylamine 24.6 parts, isopropyl alcohol 41.1 parts, isophoronediamine 3.6 parts, adipic acid dihydrazide 12.1 parts, methyl ethyl ketone 434.9 parts). The whole reaction system was mixed. Thereafter, the reaction system was stirred and held at 60 ° C. for 2 hours to complete the chain extension reaction, whereby a polyurethane solution having a carboxylate anion group content of 0.5 mmol / g and a number average molecular weight of 4000 (nonvolatile content). : 35%).

Synthesis Example 3 (Production of polyester resin as film forming component)
A reaction vessel similar to Synthesis Example 1 was charged with 479 parts of terephthalic acid, 402 parts of isophthalic acid, 87 parts of azelaic acid, 256 parts of ethylene glycol, 354 parts of 1,6-hexanediol, and 23 parts of glycerin, and the reaction system was stirred. Were heated to melt them. Next, while removing water produced by the dehydration condensation reaction, the reaction system was heated from 160 ° C. to 200 ° C. over 3 hours, and further kept at 200 ° C. for 1 hour. Next, 0.16 part of antimony trioxide was added. Next, a vacuum decompression device was connected to the reaction vessel, and a reduced pressure polycondensation reaction was performed at 235 ° C. and 2.8 kPa for 1 hour. Next, the reduced pressure state was released, the reaction system was cooled to 150 ° C., 119 parts of trimellitic anhydride was charged into the reaction system, and the temperature was kept for 1 hour. Next, 1935 parts of methyl isobutyl ketone and 1935 parts of methyl ethyl ketone were added and dissolved uniformly. Next, 125 parts of triethylamine was charged and neutralized to obtain a polyester solution (nonvolatile content: 35%) having a carboxylate anion group content of 0.4 mmol / g and a number average molecular weight of 10,000.

<Preparation of undercoat agent>
Example 1
50.5 parts of ion exchange water, 6 parts of paratoluenesulfonic acid, and 3.5 parts of triethylamine were added and mixed well. Next, 333 parts of an isopropyl alcohol solution of tetramethylolmethane-tris (1-aziridinylpropionate) (trade name “TAZO”, manufactured by Mutual Yakuhin Co., Ltd.) (non-volatile content: 30% by weight) was added to the obtained aqueous solution. Were mixed to prepare an undercoat agent.

Example 2
50.5 parts of ion exchange water, 1 part of paratoluenesulfonic acid, and 0.6 part of triethylamine were added and mixed well. Next, 333 parts of TAZO isopropyl alcohol solution (non-volatile content: 30% by weight) was mixed with the obtained aqueous solution to prepare an undercoat agent.

Example 3
50.5 parts of ion exchange water, 6 parts of paratoluenesulfonic acid, and 3.5 parts of triethylamine were added and mixed well. Next, 333 parts of isopropyl alcohol solution of trimethylolpropane-tris (1-aziridinylpropionate) (trade name “TAZM”, manufactured by Mutual Yakuhin Co., Ltd.) (non-volatile content: 30% by weight) was added to the obtained aqueous solution. Were mixed to prepare an undercoat agent.

Comparative Example 1
50 parts of the carboxyl group-containing acrylic resin solution obtained in Synthesis Example 1, 0.4 part of paratoluenesulfonic acid, and 0.3 part of triethylamine were added and mixed well. Then, 20 parts of TAZO isopropyl alcohol solution (non-volatile content 30% by weight) was mixed to prepare an undercoat agent.

Comparative Example 2
An undercoat agent was prepared by mixing 50 parts of the carboxyl group-containing polyurethane resin obtained in Synthesis Example 2 with 3.3 parts of TAZO in isopropyl alcohol (non-volatile content: 30% by weight).

Comparative Example 3
An undercoat agent was prepared by mixing 50 parts of the carboxyl group-containing polyester resin solution obtained in Synthesis Example 3 with 3.3 parts of TAZO in isopropyl alcohol (non-volatile content: 30% by weight).

<Production and evaluation of plastic film with inorganic thin film>
The undercoat agent of Example 1 was applied to a commercially available PET film (product name “E5100”, manufactured by Toyobo Co., Ltd., 38 μm thickness) using a bar coater so that the dry film thickness was 1 μm. Next, the coated film was dried (150 ° C., 60 seconds) with a circulating dryer.

  Next, using the commercially available vapor deposition apparatus (product name "NS-1875-Z", manufactured by Nishiyama Seisakusho Co., Ltd., using aluminum as the inorganic thin film seed), the vapor deposition layer has an aluminum vapor deposition thickness of 50 nm. A film was obtained. This was used as the test film of Example 1. Test films were prepared in the same manner for other examples and comparative examples.

(Adhesion)
About each aluminum vapor deposition film of an Example and a comparative example, when an adhesive tape (product name "cello tape", Nichiban Co., Ltd. product) was affixed on the vapor deposition surface, and this was peeled off vigorously in the perpendicular direction, both were aluminum. Peeling was not recognized on the vapor-deposited surface (marked as ◯ in Table 1).

(Smoothness)
About each aluminum vapor deposition film of an Example and a comparative example, the external appearance of the vapor deposition surface was evaluated visually according to the following references | standards. The results are shown in Table 1.
○ ... Excellent gloss x ... Less gloss

  About each aluminum vapor deposition film of an Example and a comparative example, the whitening of the vapor deposition surface after heating at 150 degreeC with a circulating air dryer for 1 hour, and the grade of an interference fringe were visually evaluated on the following references | standards.

(Whitening resistance)
5 ... No whitening has occurred. 4-1 ... Whitening has occurred. The smaller the number, the greater the degree.
(Interference fringe resistance)
5 ... No interference fringes are generated. 4 to 1 ... Interference fringes are generated. The smaller the number, the greater the degree.

  Next, the undercoat agent obtained in Example 1 was applied to a commercially available acrylic panel (product name “Comoglas”, manufactured by Kuraray Co., Ltd., 5 cm × 5 cm × 1 mm) on a bar coater so that the dry film thickness was 1 μm. And dried at 150 ° C. for 60 seconds in a smooth air dryer. Next, using the vapor deposition apparatus, aluminum was vapor-deposited on the undercoat surface of the test panel so that the thickness of the vapor deposition layer was 50 nm, thereby producing a test panel for crack resistance and interference fringe test. . Test panels were similarly prepared for the undercoat agents according to other examples and comparative examples.

  In addition, an aluminum plate (15 cm × 5 cm × 1 mm) bent at 60 ° in the middle was prepared as a bending instrument for the test panel.

  Subsequently, the test panel was pressed from the acrylic panel side for about 3 seconds onto the bending side of the bending instrument heated in a smooth air dryer (250 ° C.), and then bent to about 80 °. About the state of the aluminum vapor deposition layer in a bending site | part, it evaluated visually according to the following references | standards in each of the crack and peeling of a process part, and an interference fringe.

(Crack resistance)
5: No cracking or peeling occurred.
4-1 ... Cracking or peeling occurs. The smaller the number, the greater the degree.
(Interference fringe resistance)
5 ... No interference fringes are generated.
4 to 1 ... Interference fringes are generated. The smaller the number, the greater the degree.

By using a thick acrylic panel, the undercoat surface (layer) is excessively stretched in the panel bending direction. As a result, the aluminum vapor deposition layer is more likely to crack. These harsh test conditions are intended for actual in-mold injection molding.

Claims (10)

Polyfunctional aziridine derivative (A) as a film-forming component having at least three aziridinyl groups represented by the following formula (1) in the molecule, an acid catalyst neutralized with ammonia and / or a tertiary amine in it contains aziridinyl MotoHiraki ring catalyst (B) and solvent (C), and polymer (D) deposited having a functional group reactive with an aziridinyl group represented by the following formula (1) in the molecule Undercoat agent for plastic with inorganic thin film not contained as an ingredient.
(In formula (1), R ¹ and R ² each represent hydrogen or an alkyl group having 1 to 6 carbon atoms.) The undercoat agent according to claim 1, wherein the component (A) is a trifunctional aziridine compound and / or a tetrafunctional aziridine compound. The undercoat agent of Claim 2 whose trifunctional aziridine compound is what is represented by following General formula (2).
(In the formula (2), X represents hydrogen, an alkyl group, or .R ¹ and ^{R 2} are each hydrogen or an alkyl group having 1 to 6 carbon atoms represents a alkylol group having 1 to 3 carbon atoms from 1 to 6 carbon atoms R ³ represents hydrogen or a methyl group.) The undercoat agent according to any one of claims 1 to 3, wherein the acid catalyst is p-toluenesulfonic acid. (C) The undercoat agent in any one of Claims 1-4 whose components are C1-C4 alcohol and water. The undercoat agent according to any one of claims 1 to 5, wherein the component (B) is 1 to 10 parts by weight and the component (C) is 50 to 900 parts by weight with respect to 100 parts by weight of the component (A). The plastic film with an inorganic thin film which has a plastic film, the layer which consists of an undercoat agent in any one of Claims 1-6 , and the layer which consists of an inorganic thin film. The plastic film with an inorganic thin film according to claim 7 , wherein the inorganic thin film layer is an aluminum layer. A decorative film for in-mold molding comprising the plastic film with an inorganic thin film according to claim 7 or 8 as a member. The decorative film for insert molding which uses the plastic film with an inorganic thin film of Claim 7 or 8 as a member.