JP2010260942A - Surface protective film, and multilayer film having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film which can be applied in conformance to a variety of surface shapes, is good in the conformability to curved surfaces and is excellent in the durability after the application. <P>SOLUTION: This surface protective film includes a polyurethane-based resin which has a tensile elongation at break at 80°C of 120% or more and/or a gloss retention ratio after two-year outdoor weathering of 80% or more. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a surface protective film and a multilayer film including the same.

  As a method for decorating the surface of a three-dimensional structure such as a three-dimensional molded substrate, a method of attaching a decorative film or a protective film to a three-dimensional structure such as a three-dimensional molded substrate is known. Among such decorative films, examples of films used for automobile exteriors include those listed in the following publications.

Japanese Patent Laid-Open No. 08-002550 Japanese Patent No. 3851523 JP 05-155976 A JP 2007-297469 A JP-T-2002-529277 JP 2004-114346 A JP 2001-262016 A JP 2000-214310 A

  An object of this invention is to provide the film which can be affixed corresponding to various surface shapes, has the followable | trackability to a curved surface, and is excellent in durability after affixing.

  The present invention provides a surface protective film comprising a polyurethane resin having a tensile elongation at break at 80 ° C. of 120% or more and / or a gloss retention after 80 years of outdoor exposure of 80% or more. .

  Here, the tensile elongation at break is measured by using a Tensilon tensile tester with a heating oven at a temperature of 80 ° C., a gripping interval of 70 mm, and a tensile speed of 200 mm / min. The movement distance at the time of the movement is expressed as a percentage with respect to 70 mm (for example, 200% when it breaks after moving 140 mm, and the initial gripping distance at that time is 70 mm + 140 mm = 210 mm). In addition, the gloss retention after 2 years of outdoor exposure means that the surface protection film is pasted on the black plate base material outdoors (near the coast of Fuji City, Shizuoka Prefecture, Japan or equivalent), and the black plate base material is This means the retention rate of 60 ° gloss value after being left for two years with a fixed angle of 35 degrees from the south and horizontal.

  The surface protective film having the above-described configuration can be attached in accordance with various surface shapes, has good followability to a curved surface, and is excellent in durability after being attached.

  In the surface protective film of the present invention, the polyurethane resin contains a reaction product obtained by reacting a water-dispersible polycarbonate polyurethane having a cyclohexane skeleton of 20% by mass or more and a cross-linking agent. The cross-linking agent in polyurethane is preferably obtained by reacting the cross-linking agent in an amount of 0.1 to 2.0 times the equivalent number of reactive functional groups.

  The surface protective film having such a configuration is more excellent in weather resistance and further excellent in tensile breaking elongation at 80 ° C. Therefore, it exhibits excellent moldability into various three-dimensional shapes and can be suitably used as a surface protective film for exterior use. Moreover, it has the feature that there is little environmental load as waste. Here, the “functional group reactive to the crosslinking agent” is a functional group that can react with the crosslinking agent to form a crosslinked structure, and includes, for example, a carboxyl group.

  As said crosslinking agent, crosslinking agents, such as an aziridine type crosslinking agent and a polycarbodiimide type crosslinking agent, can be used. By containing the reaction product obtained by the reaction with these crosslinking agents, the surface protective film tends to be more excellent in tensile elongation at break and weather resistance at 80 ° C. Further, even when the surface protective film is discarded, since the halogen atom is not substantially contained, addition to the environment is further reduced.

  In the surface protective film of the present invention, the polyurethane resin contains a polyurethane resin obtained by a reaction between a prepolymer represented by the following general formula (1) and a trifunctional polyisocyanate having a 6-membered ring structure. Is preferred.

In the formula, A ¹ represents a glycol residue or a low molecular weight diol residue (hereinafter, the glycol residue and the low molecular weight diol residue are collectively referred to as “glycol” or “glycol residue”), and B ¹ represents an isophorone diisocyanate residue, A ² represents a polycaprolactone diol residue, and n represents an integer of 1 or more. A plurality of A ¹ may be the same or different. The glycol residue is a group obtained by removing two hydroxyl groups from glycol, the isophorone diisocyanate residue is a group obtained by removing two isocyanate groups from isophorone diisocyanate, and the polycaprolactone diol residue is a hydroxyl group derived from polycaprolactone diol. Means a group obtained by removing two from each other. Moreover, a trifunctional polyisocyanate compound shows the compound which has three or more isocyanate groups in 1 molecule.

  The trifunctional polyisocyanate having a 6-membered ring structure is preferably an isocyanate multimer having a 6-membered ring structure. Examples of the isocyanate having a 6-membered ring structure include isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, and hydrogenated MDI. Examples of trifunctional polyisocyanates include isocyanurate bodies, burette bodies, and TMP adduct bodies. Among these combinations, an isocyanurate body of isophorone diisocyanate is preferable from the viewpoint of particularly excellent tensile elongation at break and weather resistance at 80 ° C. of the surface protective film.

  It is considered that a three-dimensionally branched polyurethane coating film is formed by crosslinking the prepolymer represented by the general formula (1) with a trifunctional polyisocyanate. The surface protective film containing such a coating film is more excellent in weather resistance and further excellent in tensile breaking elongation at 80 ° C. Therefore, it exhibits excellent moldability into various three-dimensional shapes and can be suitably used as a surface protective film for exterior use. Moreover, the stress after tension is sufficiently low, and the sticking property is further improved.

  Moreover, it is preferable that the surface protection film of this invention contains 0.01-2 mass% of complex oxide pigments which consist of Cu, Fe, and Mn on the basis of the total mass of the said polyurethane-type resin. Such a surface protective film has excellent weather resistance and moldability into a three-dimensional shape, and can have various appearances and is excellent in design.

  Moreover, this invention relates to a multilayer film provided with the surface protection layer which consists of the said surface protection film, and a metal thin film layer. Such a multilayer film has excellent weather resistance and moldability into a three-dimensional shape, and can have various appearances. Therefore, it can be suitably used as an exterior film that requires both weather resistance and a metallic appearance.

  ADVANTAGE OF THE INVENTION According to this invention, the film which can be affixed corresponding to various surface shapes, has the followable | trackability to a curved surface, and is excellent in durability after affixing can be provided.

It is a figure which shows the flat plate which affixed the decoration film. It is a figure which shows the mall created about Example 3-9. It is a figure which shows the mall created about Examples 3-10 to 3-11. It is a figure which shows the mall created about Examples 3-12 to 3-13.

  Hereinafter, preferred embodiments of the present invention will be specifically described. Note that both the following first and second embodiments are polyurethanes that do not substantially contain halogen and have a low environmental impact as waste. In particular, the former uses VOC emissions because it uses an aqueous pre-solution. But the environmental impact is small. Further, since the latter uses an organic solvent-based pre-solution, the adhesiveness when applied directly to another film and laminated is excellent. In the third embodiment, a blue appearance that cannot be expressed by plating or metal and a metal appearance having a high to low gloss can be obtained by attaching a film to various surface shapes. First, the first embodiment of the surface protective film of the present invention will be specifically described.

  The surface protective film according to the first embodiment is a surface protective film made of a polyurethane resin, and the polyurethane resin reacts with a water-dispersible polycarbonate polyurethane having a cyclohexane skeleton of 20% by mass or more and a crosslinking agent. The reaction product was reacted with 0.1 to 2.0 times equivalent of the cross-linking agent with respect to the equivalent number of functional groups reactive with the cross-linking agent in the polyurethane. Is.

  A weather resistance and moldability to a three-dimensional shape are required for a molded film for paint replacement or plating replacement for automobile exteriors. In particular, the surface protective layer that protects from UV and water is required to have little deterioration in color and gloss even in outdoor exposure on a yearly basis. Moreover, the elongation accompanying the shaping | molding to a three-dimensional shape and the outstanding tensile fracture elongation which can endure the heating in the extended state are calculated | required.

  However, many of the conventionally known molded films do not have sufficient weather resistance and tensile elongation at break. Moreover, as a film excellent in these properties, a film using a halogen-containing resin such as a fluororesin is known. However, the halogen-containing resin has a problem of high environmental load as waste.

  On the other hand, the surface protective film according to the first embodiment is a surface protective film that can achieve both excellent weather resistance and moldability (tensile elongation at break) and has a low environmental load.

  The surface protective film according to the first embodiment is not particularly limited as long as it is a surface protective film having the above-described configuration, but the polyurethane resin has a tensile elongation at break at 80 ° C. of preferably 120% or more, and 150 % Or more is more preferable. Such a surface protective film exhibits excellent moldability to various three-dimensional shapes. Moreover, the gloss retention after 2 years of outdoor exposure of the polyurethane resin is preferably 80% or more, and more preferably 85% or more. Since such a surface protective film is excellent in weather resistance, it can be suitably used as a surface protective film for exterior use.

  Moreover, it is preferable that the surface protective film which concerns on 1st embodiment does not contain halogen-containing resin substantially. Here, the halogen-containing resin refers to a resin having a carbon-halogen bond in the resin. Note that “substantially free of halogen-containing resin” means a resin having a carbon-halogen bond, for example, when it contains a halogen derived from a starting material during resin synthesis but does not contain any other halogen-containing resin. Even if it is included, the content is very small, indicating that it is not in a range that affects physical properties. Such a surface protective film has a further reduced environmental impact and becomes a highly practical film.

  The polycarbonate-based polyurethane has a cyclohexane skeleton of 20% by mass or more, preferably 25% by mass or more, and more preferably 30% by mass or more. By using such a polycarbonate-based urethane, the tensile breaking elongation and weather resistance of the surface protective film tend to be further improved.

  Here, “having a cyclohexane skeleton of 20% by mass or more” refers to the mass ratio of the cyclohexane residue in the polycarbonate polyurethane as a molecular weight 72 based on the total mass of the polycarbonate polyurethane. The cyclohexane residue means a group obtained by removing two hydrogen atoms from cyclohexane.

  Examples of the water dispersible polycarbonate polyurethane include polycarbonate polyurethane having an acid value. As such a polycarbonate-type polyurethane, what has a carboxyl group is preferable. Moreover, the thing whose acid value is 10 or more is preferable, and the thing of 15 or more is more preferable. Since the water-dispersible polycarbonate polyurethane has a carboxyl group, it is crosslinked with a crosslinking agent to form a polyurethane coating film. When the polyurethane coating film is formed, the weather resistance is further improved, that is, the surface gloss is not easily lowered even when exposed to light, water, and heat for a long period of time, and defects such as cracks tend not to occur.

  Examples of the water dispersible polycarbonate-based polyurethane include R-985, R-986 (manufactured by DSM), D-6455 (manufactured by Dainichi Seika), D-6456 (manufactured by Dainichi Seika), and the like. .

The crosslinking agent is not particularly limited as long as it contains a compound capable of crosslinking the water-dispersible polycarbonate polyurethane, but an aziridine crosslinking agent or a polycarbodiimide crosslinking agent is preferable. Here, the aziridine-based crosslinking agent means a crosslinking agent containing a compound having a plurality of aziridine groups (—NCH ₂ CH ₂ ). Moreover, a polycarbodiimide type crosslinking agent means the crosslinking agent containing the compound which has multiple carbodiimide groups (-N = C = N-).

  Examples of the aziridine-based crosslinking agent include trimethylolpropane tris [3-aziridinylpropionate], trimethylolpropane tris [3 (2-methyl-aziridinyl) propionate], trimethylolpropane tris [2-aziridinylbutyrate. ], Tris (1-aziridinyl) phosphine oxide, tris (2-methyl-1-aziridinyl) phosphine oxide, pentaerythritol tris-3- (1-aziridinylpropionate), pentaerythritol tetrakis-3- (1- Aziridinyl propionate) and the like. Examples of these commercially available products include PZ-33, DZ-22E (manufactured by Nippon Shokubai Co., Ltd.), CX-100 (manufactured by Zeneca Resin), and the like.

  Examples of the polycarbodiimide-based crosslinking agent include Carbodilite V-02 (manufactured by Nisshinbo Co., Ltd.), E-01 (manufactured by Nisshinbo Co., Ltd.), D-52 (manufactured by Dainichi Seika Co., Ltd.), and the like.

  The surface protective film according to the present embodiment is obtained by reacting the polycarbonate polyurethane with 0.1 to 2.0 times equivalent of the crosslinking agent relative to the equivalent number of functional groups reactive with the crosslinking agent in the polyurethane. Containing reactants. Here, the crosslinking agent is preferably reacted by 0.25 to 1.5 times equivalent, more preferably 0.6 to 1.0 times equivalent. If the reaction amount of the crosslinking agent is less than the above range, the weather resistance of the surface protective film may not be sufficiently obtained. If it exceeds the above range, the stretchability of the surface protective film is lowered and the tensile elongation at break is sufficient. May not be obtained.

  Here, “reacting with a cross-linking agent equivalent to X times the number of functional groups reactive with a cross-linking agent in polyurethane” means a functional group that can react with the cross-linking agent in polyurethane to form a cross-linked structure ( For example, it refers to reacting 1 equivalent of carboxyl group with a cross-linking agent (calculated based on a group that reacts with the acid value of polycarbonate polyurethane) corresponding to X equivalent.

  The acid value in the polycarbonate-based polyurethane is based on a carboxyl group, and the crosslinkable functional group in the crosslinking agent is a group that reacts with the carboxyl group to form a crosslinked structure, and is an isocyanate group or carbodiimide. Group, aziridine group and the like.

  The polyurethane-based resin may further contain a resin other than the reactant, and can contain, for example, acrylic polyurethane, polyether, polyester, and the like. The content of the reactant in the polyurethane resin is preferably 60% by mass or more, more preferably 80% by mass or more, and 90% by mass or more based on the total mass of the polyurethane resin. It is more preferable.

  The polyurethane resin may further contain additives such as an antioxidant, an ultraviolet stabilizer, a light stabilizer, a heat stabilizer, and a coating aid. The content of these additives is preferably 10% by mass or less, more preferably 5% by mass or less, based on the total mass of the polyurethane resin. If the amount added is more than the above range, the effects of the present invention may not be sufficiently obtained.

  The polyurethane resin may contain an inorganic or organic pigment. Examples of the pigment include a perylene pigment, an azo pigment, a phthalocyanine pigment, an iron oxide pigment, a carbon pigment, a titanium oxide pigment, a quinophthalone dye, an azo dye, a disazo dye, an anthraquinone dye, and a benzopyran dye. Moreover, you may contain the complex oxide pigment which consists of Cu, Fe, and Mn mentioned later as a pigment.

  The thickness of the surface protective film according to the first embodiment is preferably 1 to 200 μm, more preferably 5 to 100 μm, and still more preferably 10 to 50 μm. If it is thinner than the above range, the durability of the surface protective film tends to be reduced, and if it is thicker than the above range, the moldability of the surface protective film tends to be reduced.

  The surface protective film which concerns on 1st embodiment can be manufactured with a well-known manufacturing method from the said polyurethane-type resin. For example, a surface protection film having a predetermined film thickness can be formed by dispersing a polyurethane-based resin in an organic solvent, applying the dispersion onto a substrate film, drying, and curing. As a coating method on the substrate film, for example, bar coating, roll coating, gravure coating, curtain coating, spray coating, silk screen printing or the like can be used.

  The said surface protection film can laminate | stack a transparent contact bonding layer on the said surface protection film, and can affix directly on the components used for an exterior, or a motor vehicle outer plate | board. Moreover, a designable film can be laminated and used with the surface protective film. Furthermore, a design layer can be formed on the surface protective film by printing or coating, and used as a multilayer film.

  Next, the second embodiment of the surface protective film of the present invention will be specifically described.

  The surface protective film according to the second embodiment contains a polyurethane resin obtained by a reaction between a prepolymer represented by the following general formula (1) and a trifunctional polyisocyanate derived from an isocyanate having a 6-membered ring structure. It is a surface protective film made of polyurethane resin.

In the formula, A ¹ represents a glycol residue, B represents an isophorone diisocyanate residue, A ² represents a polycaprolactone diol residue, and n represents an integer of 1 or more. A plurality of A ¹ may be the same or different. The glycol residue means a group obtained by removing two hydroxyl groups from glycol, the isophorone diisocyanate residue means a group obtained by removing two isocyanate groups from isophorone diisocyanate, and a polycaprolactone diol residue. And a group obtained by removing two hydroxyl groups from polycaprolactone diol. Moreover, a trifunctional polyisocyanate compound shows the compound which has three or more isocyanate groups in 1 molecule.

  A weather resistance and moldability to a three-dimensional shape are required for a molded film for paint replacement or plating replacement for automobile exteriors. In particular, the surface protective layer that protects from UV and water is required to have little deterioration in color and gloss even in outdoor exposure on a yearly basis. Moreover, the elongation accompanying the shaping | molding to a three-dimensional shape and the outstanding tensile fracture elongation which can endure the heating in the extended state are calculated | required.

  However, many of the conventionally known molded films do not have sufficient weather resistance and tensile elongation at break. Moreover, as a film excellent in these properties, a film using a halogen-containing resin such as a fluororesin is known. However, the halogen-containing resin has a problem of high environmental load as waste. Furthermore, since a conventional molded film has a high tensile stress at a high temperature, when it is exposed to a high temperature in a stretched state, the film tends to return to the state before stretching, and peeling tends to occur.

  In contrast, the surface protective film according to the second embodiment can achieve both excellent weather resistance and formability (tensile elongation at break), has a low environmental load, and has low tensile stress at high temperatures. It is a surface protective film.

  The surface protective film according to the second embodiment is not particularly limited as long as it is a surface protective film having the above-described configuration, but the polyurethane resin preferably has a tensile elongation at break at 80 ° C. of 120% or more, and 150 % Or more is more preferable. Such a surface protective film exhibits excellent moldability to various three-dimensional shapes. Moreover, the gloss retention after 2 years of outdoor exposure of the polyurethane resin is preferably 80% or more, and more preferably 85% or more. Since such a surface protective film is excellent in weather resistance, it can be suitably used as a surface protective film for exterior use.

  Moreover, it is preferable that the surface protection film which concerns on 2nd embodiment does not contain halogen-containing resin. Here, the halogen-containing resin refers to a resin having a carbon-halogen bond in the resin. Note that “substantially free of halogen-containing resin” means a resin having a carbon-halogen bond, for example, when it contains a halogen derived from a starting material during resin synthesis but does not contain any other halogen-containing resin. Even if it is included, the content is very small, indicating that it is not in a range that affects physical properties. Such a surface protective film has a further reduced environmental impact and becomes a highly practical film.

  The glycol residue is preferably a glycol residue having a molecular weight of 800 or less, more preferably a glycol residue of 400 or less, and even more preferably a residue of glycol of 200 or less. When the glycol residue is such a residue, the weather resistance and tensile elongation at break of the surface protective film tend to be further improved. Examples of the glycol include ethylene glycol, propylene glycol, 1,4-butanediol, 1,3-butanediol, diethylene glycol, dipropylene glycol, neopentyl glycol, polycarbonate diol, and polycaprolactone diol.

  The polycaprolactone diol residue is preferably a polycaprolactone diol residue having a molecular weight of 2000 or less, more preferably a 1000 or less polycaprolactone diol residue, and even more preferably a 700 or less polycaprolactone diol residue. Examples of the polycaprolactone include Plaxel 205, Plaxel 205H (Daicel Chemical Industries, average molecular weight 530), TONE 0200, TONE 0201 (Union Carbide, average molecular weight 530), Plaxel 208 (Daicel Chemical Industries, average) Molecular weight 830).

  N is preferably an integer of 10 or less, more preferably an integer of 5 or less, and even more preferably an integer of 2 or less. When n is an integer of 2 or less, the tensile strength at break of the surface protective film is further improved and the tensile stress tends to be further reduced.

  The prepolymer can be produced, for example, by the following method.

  In the first step, 1 equivalent of glycol and 2 equivalents of isophorone diisocyanate (hereinafter sometimes referred to as “IPDI”) are reacted to synthesize a diisocyanate compound represented by the following formula (2).

In the formula, A ¹ represents a glycol residue, and B represents an isophorone diisocyanate residue.

  As a second step, a prepolymer represented by the following formula (3) is obtained by reacting 1 equivalent of the diisocyanate compound represented by the above formula (2) with polycaprolactone diol.

In the formula, A ¹ represents a glycol residue, B represents an isophorone diisocyanate residue, and A ² represents a polycaprolactone diol residue.

  For the diisocyanate compound obtained in the first step, by reacting 1 equivalent of a diisocyanate compound with 1 equivalent of glycol and 1 equivalent of isophorone diisocyanate, or reacting 2 equivalents of diisocyanate compound and 1 equivalent of glycol, the following formula The diisocyanate compound represented by (4) can be obtained. In this case, the same glycol may be used in each step, or different glycols may be used.

In the formula, A ¹ represents a glycol residue, B represents an isophorone diisocyanate residue, and m represents an integer of 1 or more. A plurality of A ¹ may be the same or different.

  A prepolymer represented by the above formula (1) is obtained by reacting 1 equivalent of the diisocyanate compound represented by the above formula (4) with 2 equivalents of polycaprolactone diol in the same manner as in the second step. At this time, in formula (1), n represents m + 1.

  Examples of the isocyanate having a 6-membered ring structure include isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, and hydrogenated MDI. Examples of the trifunctional polyisocyanate include isocyanurate bodies, burette bodies, and TMP adduct bodies. Among these combinations, an isocyanurate body of isophorone diisocyanate is preferable from the viewpoint of particularly excellent tensile elongation at break and weather resistance at 80 ° C. of the surface protective film.

  As an isocyanurate form of isophorone diisocyanate, for example, Desmodur Z4370 (manufactured by Sumitomo Bayer Urethane Co., Ltd.), VESTANAT T1890 (trade name, manufactured by Daicel Huls Co., Ltd.) or the like can be used. Examples of the adduct of isophorone diisocyanate include adducts of isophorone diisocyanate and trimethylolpropane, trimethylolethane, pentaerythritol, and the like. For example, Takenate D-140N (manufactured by Takeda Pharmaceutical Company Limited) is used. be able to.

  The polyurethane resin obtained by the reaction of the prepolymer represented by the general formula (1) and the trifunctional polyisocyanate compound can be obtained, for example, under the following reaction conditions.

  A solution in which the prepolymer is dissolved in an organic solvent and a solution of trifunctional polyisocyanate are blended so that isocyanate group / OH group equivalent = 1.0 to 1.2. Simultaneously or in advance, a catalyst, a weathering agent, a coating aid, a colorant, etc. may be added to the prepolymer solution side in advance. After mixing and stirring them, they are applied thinly and uniformly by a known method for applying to a substrate film (for example, bar coating, roll coating, gravure coating, curtain coating, spray coating, silk screen printing, etc.) Etc. to evaporate the solvent and promote the urethane reaction. The solvent component disappears, and a polyurethane coating film is obtained by the reaction of the OH group in the prepolymer and the isocyanate group in the polyisocyanate.

  The polyurethane-based resin may further contain a resin other than the reactant, and can contain, for example, acrylic polyurethane, polyether, polyester, and the like. The content of the reactant in the polyurethane resin is preferably 60% by mass or more, more preferably 80% by mass or more, and 90% by mass or more based on the total mass of the polyurethane resin. It is more preferable.

  The polyurethane resin may further contain additives such as an antioxidant, an ultraviolet stabilizer, a light stabilizer, a heat stabilizer, a coating aid, and a catalyst. The content of these additives is preferably 10% by mass or less, more preferably 5% by mass or less, based on the total mass of the polyurethane resin. If the amount added is more than the above range, the effects of the present invention may not be sufficiently obtained.

  The polyurethane resin may contain an inorganic or organic pigment, such as perylene pigment, azo pigment, phthalocyanine pigment, iron oxide pigment, carbon pigment, titanium oxide pigment, quinophthalone dye, azo dye, disazo dye, Anthraquinone dye, benzopyran dye and the like may be contained. Moreover, you may contain the complex oxide pigment which consists of Cu, Fe, and Mn mentioned later as a pigment.

  The thickness of the surface protective film according to the second embodiment is preferably 1 to 500 μm, more preferably 5 to 250 μm, and still more preferably 10 to 100 μm. If it is thinner than the above range, the durability of the surface protective film tends to be reduced, and if it is thicker than the above range, the moldability of the surface protective film tends to be reduced.

  The surface protective film which concerns on 2nd embodiment can be manufactured with a well-known manufacturing method from the said polyurethane-type resin. For example, a surface protection film having a predetermined film thickness can be formed by dispersing a polyurethane-based resin in an organic solvent, applying the dispersion onto a substrate film, drying, and curing. As a coating method on the substrate film, for example, bar coating, roll coating, gravure coating, curtain coating, spray coating, silk screen printing or the like can be used.

  The said surface protection film can laminate | stack a transparent contact bonding layer on the said surface protection film, and can affix directly on the components used for an exterior, or a motor vehicle outer plate | board. Moreover, a designable film can be laminated and used with the surface protective film. Furthermore, a design layer can be formed on the surface protective film by printing or coating, and used as a multilayer film.

  Next, a preferred third embodiment of the present invention will be specifically described.

  The surface protective film according to this embodiment is a surface protective film made of a polyurethane resin, and a composite oxide pigment made of Cu, Fe, and Mn is 0.1 to 2 based on the total mass of the polyurethane resin. Contains by mass%.

  In the field of automobile exteriors, conventional decorations using plating and stainless steel have been performed, but harmful hexavalent chromium is mainly used in the exterior decorations using plating, which is safe and environmentally friendly. There is a problem. In addition, there is a problem that it is difficult to achieve both rust resistance, exterior strength, and weight reduction in appearance decoration using stainless steel. In addition, the metallic appearance that can be expressed by plating or stainless steel is limited. Other than high-gloss metallic tone, low gloss and red-black trivalent chrome plating color can withstand practical use. There is a method of applying a color plating color by laminating light-transmitting light-colored paint on the plated parts by spray coating, etc., but the coating to the three-dimensional shape easily causes liquid pool and thickness unevenness, and unevenness of appearance that is unsightly After all, it is not practical.

  As an alternative to these exterior decorations, exterior decorative sheets can be mentioned. However, it is difficult for conventional exterior decorative sheets to satisfy various metal exterior designs and weather resistance for exterior applications.

  On the other hand, the surface protective film according to the third embodiment can express various appearance designs, is excellent in weather resistance, and can be suitably used as a decorative sheet for exterior.

  The surface protective film according to the third embodiment is not particularly limited as long as it is a surface protective film having the above-described configuration, but the polyurethane resin preferably has a tensile elongation at break at 120 ° C. of 120% or more, and 150 % Or more is more preferable. Such a surface protective film exhibits excellent moldability to various three-dimensional shapes. Moreover, the gloss retention after 2 years of outdoor exposure of the polyurethane resin is preferably 80% or more, and more preferably 85% or more. Since such a surface protective film is excellent in weather resistance, it can be suitably used as a surface protective film for exterior use.

  Conventionally, carbon-based pigments have been used as black pigments. However, carbon-based pigments have a characteristic of being reddish when the particle size is reduced in order to obtain sufficient transparency. The complex oxide pigment made of Cu, Fe, and Mn is a black pigment and has a feature of having a bluish color by reducing the particle size. Therefore, various color tones can be expressed by combining the carbon pigment and the composite oxide pigment.

  The average particle size of the composite oxide pigment is preferably 0.01 to 1 μm, more preferably 0.03 to 0.3 μm, and further preferably 0.05 to 0.15 μm. The composite oxide pigment having such an average particle diameter is excellent in transparency when contained in a polyurethane resin. Therefore, when it is set as the multilayer film provided with a metal vapor deposition layer under the layer which consists of a surface protection film, the metal external appearance design which has a smoke-like shade can be expressed.

  The content of the composite oxide pigment in the polyurethane resin is preferably 0.01 to 2% by mass, more preferably 0.05 to 1% by mass, based on the total mass of the polyurethane resin. More preferably, it is 0.1-0.5 mass%. When the content is less than the above range, sufficient designability may not be obtained. When the content is more than the above range, weather resistance and acid resistance tend to decrease.

  The polyurethane resin preferably contains the composite oxide pigment and the carbon pigment in a ratio of 0: 100 to 100: 0 (mass ratio, composite oxide pigment: carbon pigment). By changing these content ratios arbitrarily, a surface protective film having an arbitrary hue can be obtained. If the content of the complex oxide pigment is increased, the color becomes bluish black, and if the content of the carbon pigment is increased, the color is reddish. Do not turn black.

  Examples of the composite oxide pigment include SS-069 (manufactured by Dainichi Seika), DW02-1777 (manufactured by Dainichi Seika), and the like.

  Examples of the carbon pigment include BLK # 6 (manufactured by Resino Color), AW-E2204-B (manufactured by Resino Color), and the like.

  The polyurethane-based resin may further contain a resin other than the reactant, and can contain, for example, acrylic polyurethane, polyether, polyester, acrylic, and the like. The content of the reactant in the polyurethane resin is preferably 60% by mass or more, more preferably 80% by mass or more, and 90% by mass or more based on the total mass of the polyurethane resin. It is more preferable.

  The polyurethane resin may further contain additives such as an antioxidant, an ultraviolet stabilizer, a light stabilizer, a heat stabilizer, a coating aid, and a catalyst. The content of these additives is preferably 10% by mass or less, more preferably 5% by mass or less, based on the total mass of the polyurethane resin. If the amount added is more than the above range, the effects of the present invention may not be sufficiently obtained.

  The polyurethane resin may contain an inorganic or organic pigment in addition to the composite oxide pigment and the carbon pigment. For example, a perylene pigment, an azo pigment, a phthalocyanine pigment, an iron oxide pigment, a titanium oxide pigment, It may contain a quinophthalone dye, an azo dye, a disazo dye, an anthraquinone dye, a benzopyran dye, and the like.

  The thickness of the surface protective film according to the third embodiment is preferably 5 to 250 μm, more preferably 10 to 100 μm, and still more preferably 30 to 50 μm. When the thickness is in the above range, a dark and bluish smoke-like hue can be obtained. Moreover, when thinner than the said range, there exists a tendency for durability of a surface protective film to fall, and when thicker than the said range, there exists a tendency for the moldability of a surface protective film to fall.

  The surface protective film which concerns on 3rd embodiment can be manufactured with a well-known manufacturing method from the said polyurethane-type resin. For example, a surface protection film having a predetermined film thickness can be formed by dispersing a polyurethane-based resin in an organic solvent, applying the dispersion onto a substrate film, drying, and curing. As a coating method on the substrate film, for example, bar coating, roll coating, gravure coating, curtain coating, spray coating, silk screen printing or the like can be used.

  The said surface protection film can laminate | stack a transparent contact bonding layer on the said surface protection film, and can affix directly on the components used for an exterior, or a motor vehicle outer plate | board. Moreover, a designable film can be laminated and used with the surface protective film. Furthermore, a design layer can be formed on the surface protective film by printing or coating, and used as a multilayer film.

  For example, the surface protective film may be laminated on a PET film having a surface gloss to transfer the surface property of the PET film to form a surface protective film having a surface gloss. At this time, the degree of surface gloss of the surface protective film can be adjusted by appropriately changing the gloss gloss value of the PET film to be laminated. By adjusting the surface gloss in this way, a surface protective film having further excellent design properties can be obtained.

[Multilayer film]
The multilayer film which concerns on this embodiment is a multilayer film provided with a design layer on the surface protection layer which consists of a surface protection film. Here, as the surface protective film, the surface protective film according to the first to third embodiments can be appropriately used. The surface protective layer is preferably transparent.

  The surface protective layer may have a multilayer structure in which two or more surface protective films are laminated. When the surface protective layer has a multilayer structure, the multilayer film according to the present embodiment has one or more layers made of the surface protective film according to the first to third embodiments in the surface protective layer. It only has to be. For example, a surface protective layer having a structure in which a layer made of a surface protective film according to the third embodiment and a layer made of a polyurethane resin are laminated can be used.

  The design layer is not particularly limited as long as it has excellent appearance characteristics, and examples thereof include a metal thin film layer. Examples of the metal thin film layer include an indium vapor-deposited layer, a tin vapor-deposited layer, a chromium vapor-deposited layer, an aluminum vapor-deposited layer, a finely coated layer of these metal vapor-deposited layers, an aluminum flake coat, an aluminum foil, and a stainless steel foil.

  When a surface protective layer contains the layer which consists of a surface protective film which concerns on said 3rd embodiment, it is preferable to use a metal vapor deposition layer as a design layer. According to such a combination, a multilayer film provided with various metal appearance designs can be obtained.

  The multilayer film may further include an adhesive layer on the design layer. According to such a multilayer film, it is possible to easily attach to an object in a short process. The adhesive layer is not particularly limited as long as it has adhesiveness to an object. For example, an acrylic pressure sensitive adhesive, a rubber pressure sensitive adhesive, a urethane heat sensitive adhesive, a polyester heat sensitive adhesive. For example, a layer made of a sheet material such as ABS, PVC, PP or the like may be used for integral molding with an agent, an olefin-based heat-sensitive adhesive, and a molten resin.

  In the multilayer film, a surface protective layer, a design layer, and an adhesive layer may be directly laminated, and a base material layer and an adhesive layer may be further provided between the respective layers. The multilayer film can be formed into a three-dimensional shape by vacuum forming, vacuum / pressure forming, injection molding, press molding or the like, and can be attached to a part used in an exterior, an automobile outer plate, or the like.

[Example 1-1]
70 g of water dispersible polycarbonate-based polyurethane A (product name R-986, manufactured by DSM, cyclohexane skeleton content: about 36% by mass), 0.5 g of Tinuvin 292 (light stabilizer), 0.85 g of Tinuvin 1130 (ultraviolet absorber), Triton GR-7M 0.2g, AMP95 0.1g, and deionized water 3g were mixed and stirred to prepare a pre-solution. The pre-solution was bar-coated on a PET film, dried in a hot air oven at 90 ° C. for 3 minutes, and further dried and cured at 160 ° C. for 3 minutes to obtain a surface protective film of Example 1-1.

[Example 1-2]
Example 1 was carried out in the same manner as Example 1-1, except that 0.6 times equivalent (6.5 g) of polycarbodiimide-based crosslinking agent (product name Carbodilite V-02, manufactured by Nisshinbo Co., Ltd.) was further added to the pre-solution. A surface protective film of 1-2 was obtained.

[Example 1-3]
Example 1 was carried out in the same manner as in Example 1-1, except that 1.0 times equivalent (10.9 g) of polycarbodiimide-based crosslinking agent (product name Carbodilite V-02, manufactured by Nisshinbo Co., Ltd.) was further added to the pre-solution. A surface protective film of 1-3 was obtained.

[Example 1-4]
Example 1 was carried out in the same manner as Example 1-1, except that 0.6 times equivalent (0.7 g) of an aziridine-based crosslinking agent (product name PZ-33, manufactured by Nippon Shokubai Co., Ltd.) was further added to the pre-solution. -4 surface protective film was obtained.

[Example 1-5]
Example 1 was carried out in the same manner as Example 1-1 except that 1.0 eq. (1.2 g) of an aziridine-based crosslinking agent (product name PZ-33, manufactured by Nippon Shokubai Co., Ltd.) was further added to the pre-solution. A surface protective film of −5 was obtained.

[Examples 1-6 to 1-10]
Example 1-1 was used except that water-dispersible polycarbonate polyurethane B (product name R-985, manufactured by DSM, cyclohexane skeleton content: about 33% by mass) was used instead of water-dispersible polycarbonate polyurethane A. The surface protective film of Examples 1-6 to 1-10 was obtained by blending at the same equivalent ratio as -1-5.

[Examples 1-11 to 1-15]
Example 1 except that water-dispersible polycarbonate-based polyurethane C (product name D-6455, manufactured by Dainichi Seika Co., Ltd., cyclohexane skeleton content: about 27% by mass) was used instead of water-dispersible polycarbonate-based polyurethane A. The surface protective films of Examples 1-11 to 1-15 were obtained in the same manner as in Examples 1-1 to 1-5 with the same equivalent ratio as that of -1 to 1-5.

[Examples 1-16 to 1-18]
Example 1-1 except that water-dispersible polycarbonate polyurethane D (product name U-930, manufactured by Alberting, cyclohexane skeleton content: about 17% by mass) was used instead of water-dispersible polycarbonate polyurethane A. The surface protective film of Examples 1-16 to 1-18 was obtained by blending at the same equivalent ratio as 1-3 and 1-5.

[Examples 1-19 to 1-23]
Example 1 except that water-dispersible polycarbonate polyurethane E (product name WS-5100, manufactured by Mitsui Chemicals, Inc., cyclohexane skeleton content: about 10% by mass) was used instead of water-dispersible polycarbonate polyurethane A. The surface protective films of Examples 1-19 to 1-23 were obtained by blending at the same equivalent ratio as 1 to 1-5.

[Examples 1-24 to 1-26]
Example 1-1, except that water-dispersible polycarbonate polyurethane F (product name B-122, manufactured by Bayer, cyclohexane skeleton content: 0% by mass) was used instead of water-dispersible polycarbonate polyurethane A. The surface protective films of Examples 1-24 to 26 were obtained by blending at the same equivalent ratio as in 1-3 and 1-5.

[Comparative Example 1-1]
Compared to the water-dispersible polycarbonate polyurethane A, a polyester urethane resin G (product name PR-135, manufactured by Bayer) was used except that it was blended at the same equivalent ratio as in Example 1-1. The surface protective film of Example 1-1 was obtained.

[Example 1-27]
In place of the water-dispersible polycarbonate-based polyurethane A, a polyester-based urethane resin G (product name: PR135, manufactured by Bayer) was used except that it was blended at the same equivalent ratio as in Example 1-3. Example 1-27 A surface protective film was obtained.

[Comparative Example 1-2]
Polyester urethane resin H (product name PT241, manufactured by Bayer) is used in place of water-dispersible polycarbonate polyurethane A, and isocyanurate of hexamethylene diisocyanate as a cross-linking agent (product name N3100, manufactured by Bayer) in the pre-solution. A surface protective film of Comparative Example 1-2 was obtained in the same manner as Example 1-1 except that 1.5 times equivalent was further added.

[Example 1-28]
Polyester urethane resin H (product name PT241, manufactured by Bayer) is used in place of water-dispersible polycarbonate polyurethane A, and isocyanurate of isophorone diisocyanate as a cross-linking agent (product name VPLS2150, manufactured by Bayer) 1 A surface protective film of Example 1-28 was obtained in the same manner as in Example 1-1 except that a 5-fold equivalent was further added.

[Example 1-29]
An acrylic urethane resin I (product name XP2470, manufactured by Bayer) is used in place of the water-dispersible polycarbonate polyurethane A, and isocyanurate of hexamethylene diisocyanate as a cross-linking agent (product name N3100, manufactured by Bayer) in the pre-solution. A surface protective film of Example 1-29 was obtained in the same manner as Example 1-1 except that 1.5-fold equivalent was further added.

[Comparative Example 1-3]
Technoloy S001 (75 μm thickness, manufactured by Sumitomo Chemical Co., Ltd.) was used.

[Examples 1-30 to 1-32]
In the same procedure as Example 1-1 (without V-02), 2 (V-02 0.6 equivalent), 3 (V-02 1.0 equivalent), Example 1-30 (V-02 0.3 Equivalent), 31 (V-02 2.0 equivalent), and 32 (V-02 3.0 equivalent).

[Example 2-1]
Using a propylene glycol (molecular weight 76.1), isophorone diisocyanate, polycaprolactone diol (molecular weight 530, product name Plaxel 205H, manufactured by Daicel Chemical Industries) as a raw material compound, a prepolymer in which n is 1 in the above general formula (1) Synthesized. 100 g of this prepolymer (solid content 70%, theoretical OH equivalent 1123), isophorone diisocyanate trimer (product name Desmodur Z4470, manufactured by Bayer, NCO equivalent 350), 35 g (NCO / OH equivalent ratio = 1.1), Tinuvin 292 ( 1.0 g of light stabilizer), 1.0 g of Tinuvin 384 (ultraviolet absorber), 0.005 g of DBTDL (catalyst) and an appropriate amount of an organic solvent were mixed to obtain a pre-solution. This pre-solution was bar-coated on a polypropylene film and dried and cured at 80 ° C. for 1 hour in a hot air oven to obtain a surface protective film of Example 2-1 having a thickness of 50 μm.

[Example 2-2]
Using propylene glycol (molecular weight 76.1), isophorone diisocyanate, polycaprolactone diol (molecular weight 530) as raw materials, a prepolymer having n of 2 in the above general formula (1) was synthesized, and the prepolymer (solid content 50%) The surface protective film of Example 2-2 was obtained in the same manner as in Example 2-1, except that the NCO / OH equivalent ratio was 1.1 using the theoretical OH equivalent 1818). .

[Example 2-3]
Using propylene glycol (molecular weight 76.1), isophorone diisocyanate, polycaprolactone diol (molecular weight 530) as raw materials, a prepolymer having n of 3 in the above general formula (1) was synthesized, and the prepolymer (solid content 50%) The surface protective film of Example 2-3 was obtained in the same manner as in Example 2-1, except that the NCO / OH equivalent ratio was 1.1 using the theoretical OH equivalent 2116). .

[Example 2-4]
Using propylene glycol (molecular weight 76.1), isophorone diisocyanate, polycaprolactone diol (molecular weight 530) as raw material compounds, a prepolymer having n of 4 in the above general formula (1) was synthesized, and the prepolymer (solid content 50%) The surface protective film of Example 2-4 was obtained in the same manner as in Example 2-1, except that the NCO / OH equivalent ratio was 1.1 using the theoretical OH equivalent 2414). .

[Example 2-5]
Using propylene glycol (molecular weight 76.1), isophorone diisocyanate, polycaprolactone diol (molecular weight 530) as raw material compounds, a prepolymer having n of 5 in the above general formula (1) was synthesized, and the prepolymer (solid content 50%) The surface protective film of Example 2-5 was obtained in the same manner as in Example 2-1, except that the NCO / OH equivalent ratio was 1.1 using the theoretical OH equivalent 2712). .

[Example 2-6]
Using ethylene glycol (molecular weight 62.1), isophorone diisocyanate, and polycaprolactone diol (molecular weight 530) as raw material compounds, a prepolymer in which n is 1 in the above general formula (1) is synthesized, and the prepolymer (solid content 80%) The surface protective film of Example 2-6 was obtained in the same manner as in Example 2-1, except that the NCO / OH equivalent ratio was 1.1 using the theoretical OH equivalent 974). .

[Example 2-7]
Using ethylene glycol (molecular weight 62.1), isophorone diisocyanate, and polycaprolactone diol (molecular weight 530) as raw material compounds, a prepolymer in which n is 2 in the above general formula (1) is synthesized, and the prepolymer (solid content 60%) The surface protective film of Example 2-7 was obtained in the same manner as in Example 2-1, except that the NCO / OH equivalent ratio was 1.1 using the theoretical OH equivalent 1535). .

[Example 2-8]
Using ethylene glycol (molecular weight 62.1), isophorone diisocyanate, polycaprolactone diol (molecular weight 530) as a raw material compound, a prepolymer having n of 3 in the above general formula (1) was synthesized, and the prepolymer (solid content 50%) The surface protective film of Example 2-8 was obtained in the same manner as in Example 2-1, except that the NCO / OH equivalent ratio was 1.1 using the theoretical OH equivalent 2074). .

[Example 2-9]
Using 1,4-butanediol (molecular weight 90.1), isophorone diisocyanate, polycaprolactone diol (molecular weight 530) as raw material compounds, a prepolymer in which n is 1 in the above general formula (1) is synthesized, and the prepolymer ( Surface protection of Example 2-9 in the same manner as in Example 2-1, except that 50% solids and theoretical OH equivalent 1534) were used so that the NCO / OH equivalent ratio was 1.1. A film was obtained.

[Example 2-10]
Using 1,3-butanediol (molecular weight 90.1), isophorone diisocyanate, and polycaprolactone diol (molecular weight 530) as raw material compounds, a prepolymer in which n is 1 in the above general formula (1) is synthesized, and the prepolymer ( Surface protection of Example 2-10 in the same manner as in Example 2-1, except that 50% solids and theoretical OH equivalent 1534) were used so that the NCO / OH equivalent ratio was 1.1. A film was obtained.

[Example 2-11]
Using diethylene glycol (molecular weight 106.1), isophorone diisocyanate, polycaprolactone diol (molecular weight 530) as a raw material compound, a prepolymer having n of 1 in the above general formula (1) was synthesized, and the prepolymer (solid content 50%, A surface protective film of Example 2-11 was obtained in the same manner as in Example 2-1, except that the theoretical OH equivalent 1550) was used so that the NCO / OH equivalent ratio was 1.1.

[Example 2-12]
Using dipropylene glycol (molecular weight 134.2), isophorone diisocyanate, polycaprolactone diol (molecular weight 530) as raw material compounds, a prepolymer in which n is 1 in the above general formula (1) is synthesized, and the prepolymer (solid content 50 %, Theoretical OH equivalent 1578) was used to obtain a surface protective film of Example 2-12 in the same manner as Example 2-1, except that the NCO / OH equivalent ratio was 1.1. It was.

[Example 2-13]
Using neopentyl glycol (molecular weight 104.2), isophorone diisocyanate, polycaprolactone diol (molecular weight 530) as raw material compounds, a prepolymer in which n is 1 in the above general formula (1) is synthesized, and the prepolymer (solid content 50) %, Theoretical OH equivalent 1548), and the surface protective film of Example 2-13 was obtained in the same manner as in Example 2-1, except that the NCO / OH equivalent ratio was 1.1. It was.

[Example 2-14]
Using a polycarbonate diol (molecular weight 500), isophorone diisocyanate, and polycaprolactone diol (molecular weight 530) as raw material compounds, a prepolymer having n of 1 in the above general formula (1) was synthesized, and the prepolymer (solid content 50%, theory) A surface protective film of Example 2-14 was obtained in the same manner as in Example 2-1, except that the NCO / OH equivalent ratio was 1.1 using OH equivalent 1943).

[Example 2-15]
Both A1 and A2 were synthesized using polycaprolactone diol (molecular weight 530) and isophorone diisocyanate as raw materials, and a prepolymer having n of 1 in the above general formula (1) was synthesized. The prepolymer (solid content 50%, theoretical OH equivalent 1970) The surface protective film of Example 2-15 was obtained in the same manner as in Example 2-1, except that the NCO / OH equivalent ratio was 1.1.

[Comparative Example 2-1]
Using polyoxytetramethylene glycol (molecular weight 873), isophorone diisocyanate, polycaprolactone diol (molecular weight 530) as raw material compounds, a prepolymer in which n is 1 in the above general formula (1) is synthesized, and the prepolymer (solid content 50 %, The theoretical OH equivalent 2317) was used in the same manner as in Example 2-1, except that the NCO / OH equivalent ratio was 1.1. Thus, a surface protective film of Comparative Example 2-1 was obtained. It was.

<Measurement method>
[Tensile breaking elongation]
The surface protective films of the above Examples and Comparative Examples were cut to a width of 50 mm and measured using a Tensilon tensile tester with a heating oven under the conditions of a temperature of 80 ° C., a knob interval of 70 mm, and a tensile speed of 200 mm / min. The measurement results are shown in the following table.

[Weather resistance test]
About the surface protection film of the said Example and a comparative example, it sticks to a black coating board base material and a white coating board base material through a 30-micrometer-thick acrylic adhesive layer (product name RD2737, 3M company make) transparent and smooth, and Japan In the outdoor area of Fuji City, Shizuoka Prefecture, I was exposed to the outside for two years with a fixed angle of 35 degrees from the horizontal. The film after outdoor exposure was measured for 60 ° gloss retention, color difference (ΔE *), and change in appearance when compared to an untested film. Further, the change in appearance was defined as C when a clear crack was observed visually, B when a slight crack was observed, and A when a crack was not observed. The measurement results are shown in the following table. Moreover, about Example 1-1, 1-2, 1-3, 1-30, 1-31, 1-32, the tensile fracture elongation and the external appearance after two years of outdoor exposure were confirmed. Table 6 shows.

[Tensile stress]
About Examples 2-1 to 2-15, the measurement of the tensile stress was performed as follows.
(Measurement method of tensile stress)
The surface protective film of the above Example was cut to a width of 30 mm, and measured using a Tensilon tensile tester with a heating oven under the conditions of a temperature of 80 ° C., a grip interval of 30 mm, and a tensile speed of 200 mm / min. The following table shows data obtained by converting the stress of 150% (at the time of pulling 45 mm) from the graph and converting the stress assuming a thickness of 50 μm.

[Examples 3-1 to 3-7]
Using a propylene glycol (molecular weight 76.1), isophorone diisocyanate, polycaprolactone diol (molecular weight 530, product name Plaxel 205H, manufactured by Daicel Chemical Industries) as a raw material compound, a prepolymer in which n is 1 in the above general formula (1) Synthesized. 100 g of this prepolymer (solid content 70%, theoretical OH equivalent 1123), 35 g of isophorone diisocyanate trimer (product name Desmodur Z4470, Bayer NCO equivalent 350) (NCO / OH equivalent ratio = 1.1), Tinuvin 292 (light Stabilizer (1.0 g), Tinuvin 384 (ultraviolet absorber) (1.0 g), DBTDL (catalyst) (0.005 g) and an appropriate amount of an organic solvent were mixed to prepare a pre-solution (solid content of about 70% by mass). This pre-solution, CuFeMn pigment (product name SS-069, manufactured by Dainichi Seika Co., Ltd., average particle size of about 0.1 μm, resin dispersion, pigment concentration of about 35% by mass), and carbon pigment (product name BLK # 6, manufactured by Resino Color Co., Ltd., having an average particle diameter of about 0.1 μm, a resin dispersion, and a pigment concentration of about 12% by mass) were mixed in the formulation shown in Table 8 below and stirred.

  The resulting solution was bar coated on a 0.1 mm thick polypropylene film (PP film) so that the dry film thickness was 0.05 mm. This was put in an 80 ° C. hot air oven for 3 minutes to remove the solvent, and a commercially available PET film shown in Table 9 was laminated while uncured. In the table, T60 (manufactured by Teijin DuPont) has the highest gloss, and DW (manufactured by Kaisei Kogyo Co., Ltd.) has the lowest gloss. After standing at room temperature and urethane was sufficiently cured, the PET film and PP film were peeled off to obtain a top layer coating film. The surface of the surface protective film from which the PET film has been peeled has a glossiness obtained by transferring the surface property of each PET film. An indium vapor deposition layer having a thickness of about 40 nm was laminated on the surface from which the PP film was peeled off. Furthermore, an acrylic adhesive layer was laminated on the vapor deposition layer surface and affixed to an ABS film to obtain a decorative sheet. About each Example, the sample corresponding to the lamination by PET film shown in Table 9 was produced for every Example by the same operation. In addition, Table 8 shows the color tone of the film obtained in each example.

  With respect to the decorative films obtained in Examples 3-1 to 3-7, the appearance was observed, and various metal-like appearances could be reproduced by adjusting the type, blending, and surface gloss of the color material. The results of measuring the 60 ° gloss of each flat plate sample are shown in Table 10 below, and the visual appearance is shown in Table 11. FIG. 1 is a diagram (photograph) showing a flat plate with a decorative film attached thereto. In FIG. 1, 11 is Example 3-1 (T60), 12 is Example 3-1 (E180), 13 is Example 3-1 (X44), 14 is Example 3-1 (U4), 15 represents Example 3-1 (WS (, 16 represents Example 3-1 (DW). 21 represents Example 3-2 (T60), 22 represents Example 3-2 (E180), and 23 represents Example 3-2 (X44), 24 is Example 3-2 (U4), 25 is Example 3-2 (WS), 26 is Example 3-2 (DW), and 31 is Example. 3-3 (T60), 32 is Example 3-3 (E180), 33 is Example 3-3 (X44), 34 is Example 3-3 (U4), 35 is Example 3-3 (WS) 41 is Example 3-4 (T60), 42 is Example 3-4 (E180), 43 is Example 3-4 (X44), 44 is Example 3-4 (U4) 45 denotes Example 3-4 (WS), 46 denotes Example 3-4 (DW), 51 denotes Example 3-5 (T60), 52 denotes Example 3-5 (E180), 53 Denotes Example 3-5 (X44), 54 denotes Example 3-5 (U4), 55 denotes Example 3-5 (WS), 61 denotes Example 3-6 (T60), and 62 denotes Example Example 3-6 (E180), 63 is Example 3-6 (X44), 64 is Example 3-6 (U4), 65 is Example 3-6 (WS), 66 is Example 3-6 (DW) 71 is Example 3-7 (T60), 72 is Example 3-7 (E180), 73 is Example 3-7 (X44), 74 is Example 3-7 (U4), 75 shows Example 3-7 (WS) The gloss of the high-gloss B / O film (manufactured by 3M) is 94. Further, among the samples, T60 is laminar. Chrominance examples 3-2～3-7 About you encountered a series were measured Example 3-1 as a reference (ΔE *, ΔL *, Δa *, Δb *) are shown in Table 12.

[Example 3-8]
A top layer coating film having the composition shown in Table 13 below was produced in the same manner as in Examples 3-1 to 3-7. In addition, the pigment content rate of Table 13 represents the content rate of the pigment in a coating film on the basis of the resin component total mass of a coating film. The coating film prepared here was subjected to an acid resistance test for automobile exteriors. Specifically, 0.1 N sulfuric acid was dropped on the surface of the coating film, and it was observed whether or not a spot mark remained after 24 hours. The results are shown in Table 13 as B when spot marks were observed after 24 hours and as A when no spot marks were observed.

[Examples 3-9 to 3-13]
Water-dispersible polycarbonate-based polyurethane A (product name R-986, manufactured by DSM, cyclohexane skeleton content: about 36% by mass 70 g, Tinuvin 292 (light stabilizer) 0.5 g, Tinuvin 1130 (ultraviolet absorber) 0.85 g, Triton GR -7M 0.2g, AMP95 0.1g, deionized water 3g, polycarbodiimide type crosslinking agent (product name Carbodilite V-02, manufactured by Nisshinbo Co., Ltd.) 1.0 times equivalent (10.9g) was obtained by mixing and stirring. With respect to the pre-solution, composite oxide pigments (product name DW02-1777 (hereinafter referred to as “DW”), manufactured by Dainichi Seika Co., Ltd., SS-069 described above in the proportions shown in columns 2 to 4 from the left in Table 14 A similar composite oxide pigment dispersed in a water-dispersible resin, having a pigment concentration of about 25% by mass, and a carbon pigment (AQ-I2204-B (hereinafter referred to as “ AQ ”), manufactured by Resino Color Co., Ltd., a carbon-based pigment similar to BLK # 6 dispersed in a water-dispersible resin, and a pigment concentration of about 10% by mass), and various PET films shown in Table 9 Bar coating was applied to a dry thickness of 0.03 mm on the top, dried in a hot air oven at 90 ° C. for 3 minutes, and then dried in a hot air oven at 160 ° C. for 3 minutes. The numbers indicated in columns 5 to 8 were prepared from the left side of Table 14. An indium vapor deposition layer having a thickness of about 40 nm was laminated on the surface opposite to the PET film, and an ABS film layer was interposed through an acrylic adhesive layer. Laminated on a decorative film comprising

[Example 3-14]
In Example 3-10, instead of T60, Example 1-3 was applied onto T60 to form a dry coating film, and a pre-solution was further applied and dried to obtain a coating film. Further, indium deposition and ABS layer were obtained. A decorative film comprising was obtained.

[Example 3-15]
In place of the prepolymer of Example 3-2, polycaprolactone diol (molecular weight 530, product name Plaxel 205H, Daicel Chemical Industries, OH equivalent 265) was used so that the NCO / OH equivalent ratio was 1.1. Except for this, a surface protective film of Example 3-15 was obtained using T60 in the same manner as in Example 3-2. An indium vapor deposition layer having a thickness of about 40 nm was laminated on the surface from which the polypropylene film was peeled off. Furthermore, it laminated on the decorative film provided with an ABS film layer through the acrylic adhesive layer.

[Example 3-16]
Instead of the prepolymer of Example 3-2, polycarbonate diol (molecular weight 1000, Nippon Polan 981, Nippon Polyurethane, OH equivalent 500) and polycaprolactone diol (molecular weight 530, Plaxel 205H, Daicel Chemical Industries, OH equivalent 265) ) And a mixture obtained by mixing at a mass ratio of 1: 1 was used in place of the prepolymer so that the NCO / OH equivalent ratio was 1.1. In the same manner as described above, a surface protective film of Example 3-16 was obtained using T60. An indium vapor deposition layer having a thickness of about 40 nm was laminated on the surface from which the polypropylene film was peeled off. Furthermore, it laminated on the decorative film provided with an ABS film layer through the acrylic adhesive layer.

[Example 3-17]
The same surface protective film as Example 3-16 was laminated on a multilayer film of urethane film / silicon primer / tin vapor deposition / acrylic adhesive layer / ABS film via an acrylic adhesive layer to obtain a decorative film.

  About the decorative film of Examples 3-9-17, after peeling PET film of a surface and vacuum forming, insert injection molding was performed and the automobile molding was produced. Mole exhibited various metal appearances depending on the glossiness of the PET film and the pigment content. Table 15 shows the visual appearance. FIG. 2 is a diagram (photo) showing the mall created for Example 3-9, FIG. 3 is a diagram (photo) showing the mall created for Examples 3-10 to 3-11, and FIG. It is a figure (photograph) which shows the mall created about 3-12 to 3-13. In the figure, 101 is 3-9-1, 102 is 3-9-2, 103 is 3-9-3, 104 is 3-9-4, 201 is 3-10-1, 202 is 3-10. -2, 301 is 3-11-1, 302 is 3-11-2, 401 is 3-12-1, 402 is 3-12-2, 403 is 3-12-3, 501 is 3-13-1. , 502 indicates 3-13-2, respectively. Examples 3-14 to 17 all showed the same appearance as Example 3-10-1.

11, 12, 13, 14, 15, 16, 21, 22, 23, 24, 25, 26, 31, 32, 33, 34, 35, 41, 42, 43, 44, 45, 46, 51, 52, 53, 54, 55, 61, 62, 63, 64, 65, 66, 71, 72, 73, 74, 75 ... flat plates with decorative films attached,
101, 102, 103, 104, 201, 202, 301, 302, 401, 402, 403, 501, 502.

Claims (7)

  A surface protective film comprising a polyurethane-based resin having a tensile elongation at break at 80 ° C. of 120% or higher and / or a gloss retention after 80 years of outdoor exposure of 80% or higher. The polyurethane resin is
Containing a reaction product obtained by reacting a water-dispersible polycarbonate polyurethane having a cyclohexane skeleton of 20% by mass or more with a crosslinking agent;
2. The reaction product according to claim 1, wherein the cross-linking agent in the polyurethane is reacted with 0.1 to 2.0 times equivalent of the cross-linking agent with respect to the equivalent number of reactive functional groups. Surface protection film.   The surface protection film according to claim 2, wherein the crosslinking agent is an aziridine crosslinking agent or a polycarbodiimide crosslinking agent. The polyurethane resin is
The surface protection film of Claim 1 containing resin obtained by reaction of the prepolymer represented by following General formula (1), and the trifunctional isocyanate compound which has a 6-membered ring structure.

[In the formula, A ¹ is a residue of a glycol having a weight average molecular weight of 800 or less or a residue of a low molecular weight diol, B ¹ is an isophorone diisocyanate residue, A ² is a polycaprolactone diol residue having a weight average molecular weight of 850 or less, and n is Each represents an integer from 1 to 10. However, a plurality of A ¹ may be the same or different. ]   The surface protective film according to claim 4, wherein the trifunctional isocyanate compound having a 6-membered ring structure is a multimer of isophorone diisocyanate.   Surface protection as described in any one of Claims 1-5 which contains 0.01-2.0 mass% of complex oxide pigments which consist of Cu, Fe, and Mn based on the total mass of the said polyurethane-type resin. the film.   A multilayer film provided with the surface protective layer which consists of a surface protective film as described in any one of Claims 1-6, and a metal thin film layer.