JP2022141429A - Metallic laminate and metallic molded product - Google Patents

Abstract

An object of the present invention is to provide a laminate and a compact having sufficient alkali corrosion resistance of an aluminum layer. Kind Code: A1 A metal tone laminate is constructed by laminating a thermoplastic resin layer, an aluminum layer and an adhesive layer in this order. The adhesive layer is composed of a polyester-based adhesive and has a cure index of 15 or more calculated from a specific formula for the adhesive layer. [Selection figure] None

Description

The present invention relates to a metallic laminate and a metallic molded article.

BACKGROUND ART Metal-like moldings are known as metal-like ornaments for the exterior of automobiles, such as automobile emblems. As such a metallic molded article, a molded article obtained by molding a laminated sheet having a transparent thermoplastic resin film, a metal layer, an adhesive layer and a thermoplastic resin film in this order is known (for example, See Patent Document 1). The transparent thermoplastic resin film in this molded article is, for example, a polyester polymer compound having a benzene ring and a cyclohexane ring and a main chain, and the metal of the metal layer is, for example, indium. Also, the adhesive in the adhesive layer is, for example, a polyurethane-based adhesive.

The metal-like molded body includes a transparent or translucent surface film layer, an adhesive layer, a polyester film or polyolefin film having a metal layer on at least one side, a film layer for holding the metal layer, and a urethane adhesive. A molded product obtained by molding a laminated sheet having a layer and a base film layer in this order is known (see, for example, Patent Document 2). The metal layer in this molded article is formed, for example, on the surface of the metal layer-holding film layer on the base film layer side.

Japanese Patent Application Laid-Open No. 2002-370311 Japanese Patent Application Laid-Open No. 2004-001243

Detergents used in washing automobiles and window washer liquids in automobiles are generally alkaline. This is to easily remove acidic stains that adhere in the natural world. However, when an aluminum layer is used as the metal layer in the metallic molded article, the aluminum layer may dissolve due to the contact between the alkaline liquid and the molded article, and the metallic appearance of the molded article may be impaired. .

SUMMARY OF THE INVENTION An object of the present invention is to provide a laminate and a compact having sufficient alkali corrosion resistance of an aluminum layer.

In order to solve the above problems, a metallic laminate according to the present invention has a thermoplastic resin layer, an aluminum layer and an adhesive layer laminated in this order, and the adhesive layer is composed of a polyester adhesive. The curing index of the adhesive layer calculated from the following formula is 15 or more.
(formula)
Cure index = acid value x hydroxyl value x hydroxyl value equivalent cross-linking degree (in the above formula, “acid value” is the acid value (mgKOH/g) of the polyester adhesive, and “hydroxyl value” is the polyester is the hydroxyl value (mgKOH/g) of the adhesive, and the "degree of crosslinking of the hydroxyl value equivalent" is the ratio of the hydroxyl groups of the polyester of the polyester adhesive used for crosslinking in the adhesive layer.)

Further, in order to solve the above-described problems, a metallic molded article according to the present invention is a metallic molded article obtained by molding the metallic laminate of the present invention.

ADVANTAGE OF THE INVENTION According to this invention, the laminated body and compact which have sufficient corrosion resistance with respect to the alkali of an aluminum layer can be provided.

1 is a cross-sectional view showing the layer structure of a laminate according to one embodiment of the present invention; FIG. FIG. 4 is a cross-sectional view showing the layer structure of a laminate according to another embodiment of the present invention; 1 is a cross-sectional view showing the layer structure of a molded body according to one embodiment of the present invention; FIG.

[Metallic laminate]
FIG. 1 is a cross-sectional view showing the layer structure of a metallic laminate (hereinafter also simply referred to as "laminate") according to one embodiment of the present invention. As shown in FIG. 1, the laminate 10 of this embodiment has a thermoplastic resin layer 1, an aluminum layer 2 and a first adhesive layer 3 stacked in this order. In the laminate 10 , an aluminum layer is used as the metal layer, and a polyester-based adhesive is used as the adhesive for the first adhesive layer 3 .

[Thermoplastic resin layer]
The thermoplastic resin layer 1 is made of a thermoplastic resin. The thermoplastic resin layer 1 may be substantially transparent or opaque. “Substantially transparent” means transparency sufficient for the molded article to exhibit a metallic appearance due to the aluminum layer. The substantially transparent thermoplastic resin layer 1 can be a surface layer forming the surface of the molded product.

If the thickness of the thermoplastic resin layer 1 is too thin, the thermoplastic resin layer 1 tends to wrinkle during the aluminum vapor deposition process, and the vapor deposition of aluminum tends to adhere unevenly. In addition, if the thickness of the thermoplastic resin layer 1 is too thin, the thermoplastic resin layer 1 is likely to wrinkle when the first adhesive layer 3 is applied or when the surface resin layer described later is laminated. Sometimes. If the thickness of the thermoplastic resin layer 1 is too thick, the desired molded article may not be obtained due to insufficient flexibility required when molding the laminate. Alternatively, if the thickness of the thermoplastic resin layer 1 is too thick, internal stress tends to remain during molding, and when the molded body is exposed to a high-temperature environment, the molded body tends to deform due to the stress. The thickness of the thermoplastic resin layer 1 is appropriately selected from, for example, 10 to 50 μm, more preferably 15 to 30 μm, based on various conditions such as mechanical strength, optical function, and desired moldability of the laminate 10. It is possible to decide to

The thermoplastic resin that constitutes the thermoplastic resin layer 1 may have thermoplasticity that enables molding of a molded body to be described later. The thermoplastic resin may be of one type or more, and may contain additives as long as the effects of the present embodiment can be obtained. Furthermore, the thermoplastic resin can be appropriately selected from the viewpoint of expressing desired physical properties (for example, alkali resistance, transparency, moldability, etc.) in the thermoplastic resin layer 1 .

Examples of thermoplastic resins constituting the thermoplastic resin layer 1 include polyesters such as polyethylene terephthalate (PET), modified polyesters such as glycol-modified polyethylene terephthalate (PETG), acrylic resins, polyurethanes, polycarbonates, polyolefins, and vinyl chloride. Included are resins and acrylonitrile-butadiene-styrene (ABS) resins.

The thermoplastic resin layer 1 preferably has sufficient alkali resistance according to the use of the molded article from the viewpoint of suppressing deterioration of the molded article due to alkali. Generally, the thermoplastic resin constituting the thermoplastic resin layer 1 is preferably polyester because of its low alkali liquid permeability. Among them, PET has high alkali resistance and is easily available. It is more preferable from the viewpoint of increasing the productivity of the dovetail laminate and the molded article.

The thermoplastic resin constituting the thermoplastic resin layer 1 is preferably a polyester having benzene rings and cyclohexane rings in the main chain, such as PETG, from the viewpoint of further improving the moldability of the laminate. PETG is a glycol-modified polyethylene terephthalate, and has a molecular structure in which some of the structural units derived from ethylene glycol in the monomer of PET are replaced with structural units derived from cyclohexanedimethanol. The substitution rate of structural units derived from ethylene glycol to structural units derived from cyclohexanedimethanol can be appropriately determined from the viewpoint of desired moldability, and may be, for example, 30 to 40 mol %.

[Aluminum layer]
The aluminum layer 2 is a layer made of metal aluminum. The aluminum layer 2 may contain elements other than aluminum as long as it exhibits the desired metallic appearance. For example, the aluminum layer 2 may contain a dopant other than aluminum to change the hue of the metallic appearance.

If the thickness of the aluminum layer 2 is too thin, the light transmittance of the aluminum layer 2 becomes too high, and the expression of metallic luster may be insufficient. If the thickness of the aluminum layer 2 is too thick, the expression of the metallic appearance and the concealability of the aluminum layer 2 will peak out, which may lead to an increase in cost, and cracks or whitening may occur during heat molding in the production of the molded product. may become easier to wake up. The thickness of the aluminum layer 2 can be appropriately determined, preferably from 20 to 100 nm, based on various conditions such as optical effects and desired formability of the laminate 10 .

It is preferable that the aluminum layer 2 is in close contact with the surface of the thermoplastic resin layer 1 from the viewpoint of sufficiently exhibiting alkali resistance in the molded article. Such an aluminum layer 2 can be formed on the surface of the thermoplastic resin layer 1 using known techniques such as vacuum deposition, sputtering and chemical vapor deposition (CVD). Aluminum can be vapor-deposited in planar form and can form layers with high reflectance and high brightness. Therefore, the aluminum layer 2 is advantageous from the viewpoint of increasing the L value (brightness) of the compact.

[First adhesive layer]
The first adhesive layer 3 is composed of a polyester adhesive. A polyester-based adhesive is composed of a composition containing polyester as a main component. As used herein, the term "main component" means the component with the highest amount in the composition. One or more types of polyester may be used to form the polyester-based adhesive.

In addition to containing polyester as a main component, the polyester-based adhesive may further contain other resins and additives within a range that satisfies the curing index conditions described later. Examples of other resins include resins having a polar group, which are added to increase the cohesive strength of the first adhesive layer 3, as long as they are compatible with the polyester. include vinyl chloride resins, epoxy resins, polystyrene and polyvinyl ethers. Examples of additives include defoamers, leveling agents, antioxidants, UV absorbers and colorants. Polyester-based adhesives can improve the alkali resistance of laminates and molded articles compared to polyurethane-based or acrylic-based adhesives.

The curing index of the first adhesive layer 3 is 15 or more. The "curing index" is calculated from the following formula.
(formula)
Curing index = acid value x hydroxyl value x degree of cross-linking of hydroxyl value equivalent

The higher the hardening index, the more it is possible to reduce corrosion of the aluminum layer 2 in the laminate or compact due to the alkaline solution (higher alkali resistance). From such a viewpoint, the curing index is preferably 20 or more, more preferably 25 or more, still more preferably 30 or more, and even more preferably 40 or more. The cure index may be within a range that can be achieved by the structure of the polyester, and may be 350 or less from this point of view. The cure index can be adjusted by the degree of cross-linking of the acid value, hydroxyl value and hydroxyl value equivalent given in the above formula.

The “acid value” in the above formula is the acid value (mgKOH/g) of the polyester adhesive in the first adhesive layer 3 . The acid value is preferably high from the viewpoint of achieving good adhesion to polar surfaces. When the acid value is high, the adhesion at the interface between the first adhesive layer 3 and the aluminum layer 2 adhering thereto is strengthened, and bubbles are less generated at the interface between the two layers. It is effective in preventing the intrusion of alkaline liquid. Further, when the acid value is high, the compatibility between the polyester adhesive and the resin for improving the cohesive strength is enhanced.

The acid value of the polyester adhesive can be appropriately determined according to the degree of crosslinking of the curing index, hydroxyl value, and hydroxyl value equivalent in the above formula. is preferably 0.3 mgKOH/g or more, more preferably 0.4 mgKOH/g or more. The acid value of the polyester-based adhesive is preferably as high as possible from the viewpoint of increasing the curing index, but may be within a range that can be achieved with the polyester-based adhesive, and is required to have sufficient stability as a coating material. From this point of view, the acid value of the polyester-based adhesive may be, for example, 40 mgKOH/g or less, or may be 35 mgKOH/g or less. The acid value of the polyester-based adhesive may be adjusted within the range of the above acid value by using two or more polyester-based adhesives in combination.

The acid value of the polyester-based adhesive may be a value measured by a known method for measuring the acid value of a polyester-based adhesive as specified in Japanese Industrial Standard (JIS) K0070: 1992, and may be a catalog value. may The acid value can be adjusted by adjusting the amount of free fatty acid in the polyester adhesive. The acid value may be the acid value of the polyester in the polyester adhesive when the polyester adhesive does not substantially contain a component having an acid value other than the polyester.

The “hydroxyl value” in the above formula is the hydroxyl value (mgKOH/g) of the polyester adhesive in the first adhesive layer 3 . The hydroxyl value is preferably high from the viewpoint of increasing the number of hydroxyl groups that can become cross-linking points in the polyester-based adhesive. When the hydroxyl value is high, the cohesive force of the first adhesive layer 3 is increased by subjecting the hydroxyl groups of the polyester constituting the polyester adhesive to cross-linking. It is effective in strengthening the adhesion with the layer 2.

Similarly to the acid value, the hydroxyl value of the polyester-based adhesive can be appropriately determined according to the degree of crosslinking of the curing index, acid value, and hydroxyl value equivalent in the above formula. The hydroxyl value of the adhesive is preferably 0.5 mgKOH/g or more. The hydroxyl value of the polyester-based adhesive is preferably as high as possible from the viewpoint of increasing the curing index, but may be within a range that can be achieved with the polyester-based adhesive, and may be, for example, 40 mgKOH/g or less. The hydroxyl value of the polyester-based adhesive may be adjusted within the above hydroxyl value range by using two or more polyester-based adhesives in combination.

The hydroxyl value of the polyester adhesive may be a value measured by a known method for measuring the hydroxyl value of the polyester constituting the polyester adhesive as specified in JIS K0070: 1992, and may be a catalog value. good too. The hydroxyl value can be adjusted, for example, by introducing hydroxyl groups into the polyester constituting the polyester adhesive. The hydroxyl value may be the hydroxyl value of the polyester in the polyester adhesive when the polyester adhesive does not substantially contain a component having a hydroxyl value other than the polyester.

The “degree of cross-linking of the hydroxyl value equivalent” in the above formula is the ratio of the hydroxyl groups of the polyester of the polyester adhesive in the first adhesive layer 3 to cross-linking. The degree of cross-linking can be determined according to the type and amount of the cross-linking agent. For example, when the cross-linking agent is a polyisocyanate, the isocyanate groups generally react substantially one-to-one with the hydroxyl groups of the polyester. Therefore, if the cross-linking agent is polyisocyanate, the "hydroxyl equivalent cross-linking degree" is expressed by the ratio of the amount of isocyanate groups to the amount of hydroxyl groups of the polyester in the first adhesive layer 3 .

More specifically, the "degree of crosslinking of the hydroxyl equivalent" is the degree of crosslinking of the crosslinkable functional group per hydroxyl equivalent, and is the ratio of the NCO equivalent of isocyanate, which is the crosslinkable functional group, to the hydroxyl equivalent of the polyester. , that is, NCO equivalent/hydroxyl equivalent. Here, the NCO equivalent may be calculated from the amount of polyisocyanate used (unit: g), the NCO % of the polyisocyanate, and the mass of NCO equivalent to 1 mol (42 g). The hydroxyl equivalent may be calculated from the amount of polyester resin used (unit: g), the hydroxyl value of the polyester resin, and the mass of OH equivalent to 1 mol (17 g).

The degree of cross-linking of the hydroxyl value equivalent is preferably high from the viewpoint of strengthening the adhesion between the first adhesive layer 3 and the aluminum layer 2 and increasing the alkali resistance of the laminate or molded article. The hydroxyl groups derived from the polyester constituting the polyester-based adhesive serve as cross-linking points, so that bonds such as chemical bonds or hydrogen bonds are further introduced into the first adhesive layer 3, and the first adhesive layer 3 becomes more It is possible to form dense three-dimensional structures. As a result, the cohesive force of the first adhesive layer 3 can be further increased, and the permeation of the alkaline liquid can be further suppressed.

The degree of cross-linking of the hydroxyl value equivalent may vary depending on the type of cross-linking agent or the type of polyester. From the viewpoint of suppression, and from the viewpoint of suppressing the influence of uncrosslinked hydroxyl groups on the water resistance and alkali resistance of the laminate or molded article, the degree of crosslinking of the hydroxyl value equivalent is preferably 0.1 or more. 0.3 or more is more preferred, 0.5 or more is even more preferred, and 1 is most preferred.

However, the degree of crosslinking of the hydroxyl value equivalent calculated when producing the polyester-based adhesive composition may exceed 1 as a theoretical value, and may be, for example, 1.2 or less, or 1.1 or less. may be For example, increasing the degree of cross-linking from 1 to more than 1, for example from 1 to 1.2, is preferable from the viewpoint of completing the reaction between the cross-linking agent and the polyester resin more quickly. In addition, reducing the degree of cross-linking from the side exceeding 1 toward 1, for example, from 1.2 or less to approaching 1, reduces the amount of uncross-linked cross-linking agent contained in the first adhesive layer. preferable from this point of view. Further, it is preferable to bring the degree of cross-linking from 0.1 to close to 1 from the viewpoint of suppressing the influence of the unreacted cross-linking agent on the alkali resistance of the laminate or molded article.

The degree of cross-linking of the hydroxyl value equivalent is determined by the type of cross-linking agent blended in the first adhesive layer 3 or the reactivity of the cross-linking agent with respect to hydroxyl groups under the conditions under which the first adhesive layer 3 is subjected to adhesion, It can be appropriately determined depending on the amount of the cross-linking agent. As described above, in the case of a cross-linking agent that normally bonds to hydroxyl groups at room temperature, such as polyisocyanate, the degree of cross-linking of the hydroxyl value equivalent is the ratio of the amount of cross-linkable functional groups possessed by the cross-linking agent to the amount of hydroxyl groups. can be represented. If the first adhesive layer 3 is a cross-linking agent having reactivity with hydroxyl groups at a predetermined ratio of less than 1 under the conditions under which the first adhesive layer 3 is subjected to adhesion, the ratio of the amount of cross-linking agent to the amount of hydroxyl groups is The degree of cross-linking in hydroxyl equivalents can be determined by multiplying the reaction rate of .

The degree of crosslinking of the hydroxyl value equivalent can be adjusted, for example, by adjusting the amount of a crosslinking agent such as polyisocyanate having a plurality of hydroxyl-reactive functional groups added to the polyester-based adhesive. Moreover, the degree of cross-linking of the hydroxyl value equivalent can be adjusted by using cross-linking agents having different reaction rates to hydroxyl groups.

Examples of preferred cross-linking agents include polyisocyanates, examples of which include hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, isocyanurates of these polyisocyanates, Trimethylolpropane (TMP) adducts, prepolymers terminated with isocyanate groups are included.

In the case of producing the laminate of the present embodiment, the degree of cross-linking of the hydroxyl value equivalent may be estimated according to the production conditions of the laminate and the material of the first adhesive layer. For example, assuming that all of the cross-linking agent reacts stoichiometrically with the polyester-based resin, the degree of cross-linking of the hydroxyl value equivalent in the laminate is estimated from the amount of the polyester-based adhesive used and the amount of the cross-linking agent used, you should decide. Theoretically, the amount of the cross-linking agent used may be determined so that the degree of cross-linking with a hydroxyl value equivalent higher than 1.0 is obtained, but the excessive cross-linking agent does not impair the effects of the present invention. should be determined in

Alternatively, the degree of cross-linking of acid value, hydroxyl value and hydroxyl value equivalent may be estimated by hydrolysis of the first adhesive layer 3 in the laminate or molding. For example, the first adhesive layer 3 in the laminate or molded body is treated under predetermined conditions to hydrolyze the urethane bonds. Then, by presuming that the hydroxyl groups generated in the treatment and amino groups in substantially the same amount as the hydroxyl groups in the polymer compound derived from the polyester-based adhesive are hydroxyl groups before crosslinking, the hydroxyl group value in the first adhesive layer 3 and The degree of cross-linking in hydroxyl equivalents may be estimated. Similarly, among the hydrolyzates of the first adhesive layer 3, the acid value in the first adhesive layer 3 is estimated by estimating as described above for the compound having a lower molecular weight than the polymer compound. may

The first adhesive layer 3 may have physical properties other than the curing index within the range where the effects of the present embodiment are exhibited. The molecular weight of the polyester in the first adhesive layer 3 can be appropriately determined according to the desired physical properties of the polyester adhesive. For example, the molecular weight of the polyester in the first adhesive layer 3 may be appropriately determined from the viewpoint of physical properties such as shearing force, adhesion strength and viscosity of the polyester adhesive. By appropriately determining the molecular weight of the polyester, it is possible to further improve the adhesion of the first adhesive layer 3 or the coatability of the polyester adhesive.

The molecular weight of the polyester in the first adhesive layer 3 is preferably 5000 or more, more preferably 6000 or more, in terms of number average molecular weight, for example, from the viewpoint of enhancing the adhesion of the first adhesive layer 3. . For example, from the viewpoint of the coatability of the polyester-based adhesive, the number average molecular weight of the polyester in the first adhesive layer 3 is preferably 50,000 or less, more preferably 40,000 or less.

The number average molecular weight of the polyester may be a value measured by a known technique for measuring the number average molecular weight of the polyester constituting the polyester adhesive, such as gel permeation chromatography (GPC), or may be a catalog value. good.

Moreover, the glass transition temperature of the polyester in the first adhesive layer 3 can be appropriately determined from the viewpoint of the handleability of the laminate. If the glass transition temperature is too low, the viscosity or storage elastic modulus of the resin in the first adhesive layer 3 may be lowered in a high-temperature environment, resulting in insufficient durability at high temperatures. If the glass transition temperature is too high, the deformability of the first adhesive layer 3 may be insufficient, and the adhesiveness to the material to be bonded may be insufficient, for example, when bonding with the surface resin layer described later. Even if the deformability of the first adhesive layer 3 is insufficient, as a method for sufficiently enhancing the adhesiveness by bonding, there is a method of bonding while heating with a heating roll. This method requires caution because the thermoplastic resin layer is likely to wrinkle. From the viewpoint of sufficiently exhibiting the durability and deformability at high temperatures, the glass transition temperature is preferably -10 to 30°C, more preferably 0 to 20°C. Moreover, from the viewpoint of enabling the first adhesive layer 3 to sufficiently follow the adhesive surface and be deformable at room temperature (for example, 20° C.), the glass transition temperature is preferably 20° C. or lower.

The glass transition temperature of the polyester in the first adhesive layer 3 is a value measured by a known method for measuring the glass transition temperature of the polyester constituting the polyester adhesive, as specified in JIS K7121:2012. It may be a catalog value.

The polyester-based adhesive for the first adhesive layer 3 can be appropriately selected within the range of having the desired physical properties as described above. The polyester-based adhesive may be a synthetic product or a commercially available product.

The thickness of the first adhesive layer 3 is appropriately determined according to various conditions required for the laminate or molded body, such as the state of the surface to which the first adhesive layer 3 adheres and the desired adhesive strength. you can If the thickness of the first adhesive layer 3 is too thin, the adhesive tends to partially drop out or repel when the polyester adhesive is applied to the thermoplastic resin layer. Also, if the thickness of the first adhesive layer 3 is too thin, the wettability of the portion to be adhered (bonded) to the first adhesive layer 3 will be insufficient, resulting in insufficient adhesive strength. There is On the other hand, if the thickness of the first adhesive layer 3 is too thick, the stress generated in the first adhesive layer 3 when a shearing force is applied to the first adhesive layer 3 increases, Detachment of the adhesive layer 3 is likely to occur. The desired adhesiveness and peeling resistance of the first adhesive layer 3 can be appropriately determined according to the application of the laminate, so the thickness of the first adhesive layer 3 is determined by the application of the laminate. can be determined as appropriate. For example, in the case of a laminate for constructing a molded body for automobile exterior, the thickness of the first adhesive layer 3 may be appropriately determined within the range of 4 to 10 μm (for example, 10 μm).

[Other layers]
The laminate of the present embodiment may further have layers other than those described above as long as the effects of the present embodiment can be obtained. The thickness of the other layer may be appropriately determined within a range in which the desired function can be exhibited, and may appropriately contain other components such as additives other than the main component.

For example, the laminate 10 may further have a surface resin layer that adheres to the first adhesive layer 3 .

The surface resin layer is a layer forming the surface of the laminate 10 . It is preferable for the surface resin layer to have transparency from the viewpoint of obtaining the metallic appearance of the aluminum layer 2 more clearly. In addition, it is preferable that the surface resin layer has weather resistance from the viewpoint of enhancing the durability of the laminated body or molded body for exterior use. Furthermore, it is preferable that the surface resin layer is made of a thermoplastic resin from the viewpoint of ensuring the moldability of the laminate.

From the above point of view, the surface resin layer is preferably composed of a thermoplastic resin having transparency and weather resistance. Examples of transparent thermoplastic resins include acrylic resins, fluororesins, polyvinyl chloride, polyolefins, polystyrene, polyurethanes, polyamides, ABS resins, polyesters, polycarbonates, silicone resins and alicyclic polyolefins. Examples of weatherable thermoplastics include acrylics, polyesters, polycarbonates, silicones and cycloaliphatic polyolefins. Among them, acrylic resin is preferable from the viewpoint of having sufficient transparency and weather resistance.

Further, for example, the laminate 10 may further have an additional adhesive layer (hereinafter also referred to as a "second adhesive layer") and a base material layer. The adhesive layer and the base material layer are further overlapped in this order on the side of the thermoplastic resin layer 1 opposite to the aluminum layer 2 .

The second adhesive layer is a layer for bonding the thermoplastic resin layer 1 and the substrate layer. The second adhesive layer is composed of an adhesive capable of bonding the thermoplastic resin layer 1 and the substrate layer. The adhesive can be appropriately selected from known adhesives according to the materials of both layers. For example, the adhesive constituting the second adhesive layer may be the same as or different from the polyester-based adhesive described above.

Examples of such adhesives other than the polyester-based adhesives described above include polyurethane-based, polyethylene-based, polyamide-based, polyvinyl chloride-based, polychloroprene-based, carboxylated rubber-based, thermoplastic styrene-butadiene rubber-based, acrylic-based, Included are styrenic, cellulosic, alkyd, polyvinyl acetate, ethylene vinyl acetate copolymer, polyvinyl alcohol, epoxy and silicone adhesives, as well as natural and synthetic rubbers.

The base material layer is a layer for reinforcing the laminate and molded article. From the viewpoint of maintaining the shape of the molded article, the substrate layer preferably has a mechanical strength suitable for the application and shape of the molded article. Moreover, from the viewpoint of ensuring the moldability of the laminate, the substrate layer is preferably made of a thermoplastic resin. The base material layer may or may not have transparency. Examples of thermoplastic resins forming the base layer include acrylic resins, polyurethanes, polyesters, polycarbonates, polyolefins, vinyl chloride resins and ABS resins.

FIG. 2 is a cross-sectional view showing the layer structure of a laminate according to another embodiment of the invention. As shown in FIG. 2 , the laminate 20 has the surface resin layer 4 adhered to the first adhesive layer 3 of the laminate 10 . Furthermore, a second adhesive layer 5 and a base material layer 6 are laminated in this order on the surface of the thermoplastic resin layer 1 of the laminate 10 opposite to the aluminum layer 2 . Thus, in the laminate 20 , the aluminum layer 2 is arranged on the surface side of the thermoplastic resin layer 1 .

The use of the laminate 20 may be the use of automobile exteriors, and the second adhesive layer 5 and the base material layer 6 are appropriately determined according to the use. In this case, as an example, the adhesive that forms the second adhesive layer 5 is a polyester-based adhesive, and the thermoplastic resin that forms the base material layer 6 is an ABS resin. The adhesive constituting the second adhesive layer 5 may be the same as or different from that of the first adhesive layer 3 . The laminated body 20 can be used for decoration with a metallic appearance of the aluminum layer 2 by making the surface resin layer 4 side in the lamination direction the front side and adhering the base layer 6 to a portion to be decorated.

[Laminate production method]
The laminate of the present embodiment can be manufactured by a method capable of realizing the layer structure described above, and such a method can be realized using a known method for manufacturing a laminate. be.

For example, in the laminate of the present embodiment, the aluminum layer 2 is formed on one surface of the thermoplastic resin layer 1 by, for example, vacuum deposition, and the first adhesive layer 3 is formed on the surface of the aluminum layer 2 by, for example, bonding or It can be produced by forming by coating and drying.

In the case of further having the surface resin layer 4, the laminate of the present embodiment is formed by forming the aluminum layer 2 on one surface of the thermoplastic resin layer 1 by vacuum deposition, and applying the first adhesive on one surface of the surface resin layer 4. Layer 3 is formed. Then, the aluminum layer 2 and the first adhesive layer 3 are bonded together and pressed against each other. Thus, it is possible to manufacture the laminate described above.

Alternatively, in the case of further having the surface resin layer 4, the laminate of the present embodiment has the surface of the first adhesive layer 3 in the laminated structure of the thermoplastic resin layer 1, the aluminum layer 2 and the first adhesive layer 3. In addition, the surface resin layer 4 is attached and pressed against each other. Thus, it is possible to manufacture the laminate described above.

Similarly, in the case of further having the second adhesive layer 5 and the base layer 6, the laminate of the present embodiment forms the second adhesive layer 5 on the other surface of the thermoplastic resin layer 1, It can be produced by bonding the substrate layer 6 to the two adhesive layers 5 and pressing them against each other.

Alternatively, in the case of further having the second adhesive layer 5 and the base layer 6, the laminate of the present embodiment forms the second adhesive layer 5 on one surface of the base layer 6, and the second adhesive layer 5 is formed on one surface of the base layer 6. It can be produced by bonding the adhesive layer 5 and the thermoplastic resin layer 1 together and pressing them against each other.

In the above manufacturing method, when applying a cross-linking agent to the adhesive layer, the adhesive layer can be formed by a known method. For example, in the above case, the adhesive and the cross-linking agent are blended in a liquid state and mixed. Then, the obtained adhesive is applied to the site where the adhesive layer is to be formed. It is possible to form an adhesive layer in this way. Application of the adhesive can be achieved by known techniques, for example, using a bar coater, knife coater, gravure coater, or triple reverse coater. A gravure coater is more preferably used for applying the adhesive, and kiss gravure is more preferably used.

[Use]
The laminate in the embodiment of the present invention is suitably used for the exterior of moving bodies such as automobiles and motorcycles. The laminate preferably further has desirable physical properties from the viewpoint of exterior use. Examples of such preferred physical properties include weather resistance, heat resistance and strength.

In exterior applications, laminates and molded articles, which will be described later, tend to deteriorate due to sunlight. Weather resistance is the property of controlling and preventing deterioration of appearance or strength due to sunlight. The weather resistance of the laminate can be expressed by forming the surface of the laminate with the weather-resistant resin material described above.

In exterior applications, the laminate and the molded article described below are exposed to a temperature environment in which high temperatures during the daytime and low temperatures at nighttime are repeated during use, and are particularly prone to deterioration in high temperature environments during the daytime. Heat resistance is a property of suppressing and preventing appearance deterioration or strength reduction due to a high-temperature environment during use of a laminate or molded article. For the heat resistance of the laminate, use a resin material that has sufficient stability in a high-temperature environment for exterior applications, or use a material with a sufficiently small difference in thermal expansion or thermal contraction for the materials of adjacent layers in the lamination direction. can be expressed by using The heat resistance of the laminate can be appropriately determined according to the uses of the laminate and molded article.

In exterior applications, the laminated body and the molded body described later are susceptible to forces from the external environment, and in addition to having sufficient strength to maintain their own shape, they also have sufficient strength to withstand external forces that may be applied during use. It is preferred to have The strength of the molded product can be obtained from the product of the tensile modulus of elasticity and the thickness of the laminate, and the tensile modulus of elasticity of the laminate can be appropriately determined according to the application and thickness of the laminate and molded product. It is possible to decide. Therefore, it is possible to define the strength according to the application of the laminate and molded article by the tensile modulus of the laminate.

[Metallic molding]
A metallic molded article according to one embodiment of the present invention (hereinafter also referred to simply as a "molded article") is obtained by molding the metallic laminate of the present embodiment described above. FIG. 3 is a cross-sectional view showing the layer structure of a molded body according to one embodiment of the present invention. As shown in FIG. 3, the molded body 100 includes a convex portion 101 and edge portions 102 located on both sides thereof. The convex portion 101 is a portion having a trapezoidal cross-sectional shape having an upper side on the upper side and a lower side longer than the upper side on the lower side. The edge portion 102 is a portion that extends further laterally from the lower side of the trapezoid.

The molded body 100 has a layer structure in which a substrate layer 6, a second adhesive layer 5, a thermoplastic resin layer 1, an aluminum layer 2, a first adhesive layer 3 and a surface resin layer 4 are laminated in this order. is doing. In molded body 100 , all layers are in close contact with adjacent layers in the stacking direction, and are exposed at edges of edge portion 102 . Also, Lb in FIG. 3 represents the distance (width) of the edge portion 102 from the convex portion 101 . The width Lb of the edge portion 102 is determined according to the specifications of the molded article 100, and when the molded article 100 is an ornament for the exterior of an automobile, for example, it is set to less than 0.8 mm, for example, 0.7 mm. can do.

The molded article of this embodiment can be produced by a known method for molding a thermoplastic resin sheet material having a metal layer, except that the laminate of this embodiment is used as a material. Examples of methods by which the compacts of this embodiment can be manufactured include vacuum forming, pressure forming, vacuum pressure forming and press forming.

The molded body 100 is adhered to the site of use by methods known in automotive exterior applications. For example, a filler is filled in the depression on the back side of the convex portion 101 surrounded by the base material layer 6 on three sides of the top surface and the two side surfaces contiguous thereto during use, and the filler is covered and the bottom surface of the molded body 100 is covered. A mounting adhesive layer is formed to configure. The filler may be any resin material that can be commonly used in molding, such as a two-component curing urethane resin material.

Then, the molded body 100 is adhered to a desired installation location, for example, a location to be decorated on the outer surface of an automobile, via the adhesive layer. The molded body 100 is, for example, an emblem, an insignia, a patch, a sticker, or a sticker that can be deformed so as to follow the shape of the surface of an object to be attached to the exterior of a vehicle such as an automobile or the surface of an object installed outdoors. , labels, nameplates or ribbons. The molded article 100 is particularly useful as a molded article having a three-dimensional structure such as the above emblem.

[Effect]
A laminate according to an embodiment of the present invention is configured by stacking a thermoplastic resin layer, an aluminum layer and a first adhesive layer in this order. The laminate of this embodiment has a structure in which the aluminum layer is sandwiched between the first adhesive layer made of a polyester-based adhesive and the thermoplastic resin layer. Therefore, the first adhesive layer exhibits sufficiently strong adhesion to the aluminum layer, and as a result, a strong laminated structure including the aluminum layer is formed. Therefore, penetration of the alkaline solution into the aluminum layer from the outside is suppressed, and as a result, dissolution of the aluminum layer by the alkaline solution is suppressed.

Moreover, the first adhesive layer composed of a polyester-based adhesive has an acid value and a hydroxyl value at which the polyester-based adhesive exhibits a sufficient curing index. Therefore, sufficient adhesiveness as described above is exhibited, sufficient adhesive strength is exhibited in the laminate, and the dissolution distance in the laminate and molded article is sufficiently reduced. As a result, alkali corrosion of the aluminum layer is sufficiently suppressed. The "dissolution distance" refers to the tip of the portion where the aluminum layer is dissolved from the edge of the laminate or molded body where the alkaline liquid penetrates when the alkaline liquid penetrates inside from the edge of the laminated body or molded body. It is the distance to the deepest part.

The laminate may be molded as a sheet material for molding to form a compact. In the laminate according to the embodiment of the present invention, the dissolution distance can be made shorter than the conventional one, for example, 0.7 mm or less. On the other hand, in a molded product obtained by molding the laminate, a margin corresponding to the dissolution distance (for example, the above-mentioned edge 102 ) is set. In the molded article of the embodiment of the present invention, since the dissolution distance of the laminate is shorter, the margin can be made shorter, for example, 0.7 mm or less, which is sufficiently small compared to the conventional molded article. . Therefore, the embodiment of the present invention realizes a molded article excellent in decorativeness, in which deterioration of the metallic appearance due to alkali corrosion is prevented and the margin of the peripheral edge for the corrosion prevention is smaller in the application of decoration. It is advantageous to

Further, the laminate of the embodiment of the present invention is a transparent thermoplastic resin composed of a polyester having an acrylic resin-based surface resin layer, a first adhesive layer, an aluminum layer, and a benzene ring and a cyclohexane ring in the main chain. layer, a second adhesive layer and a substrate layer composed of a thermoplastic resin. A laminate having such a structure clearly expresses the metallic appearance of the aluminum layer while being protected by the surface resin layer, and the mechanical strength is enhanced by the base material layer. It is even more advantageous as a material sheet for molding.

[Modification]
The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining technical means disclosed in different embodiments are also included in the technical scope of the present invention.

For example, in laminates 10 and 20, aluminum layer 2 may be stacked on thermoplastic resin layer 1 via another layer. For example, the thermoplastic resin layer 1 and the aluminum layer 2 may be overlapped via a layer having excellent adhesion to both layers. Examples of such layers include an adhesive layer and an organic or an inorganic intermediate layer.

Also, the molded article of the present invention may be molded from the laminate 10 . For example, a mold may be formed by laminating a release layer on the first adhesive layer 3 and molding. Such a molded article may be installed at the installation location by the adhesive force of the first adhesive layer 3, or, similar to the molded article 100 described above, the filler and the adhesive layer for installation covering it may be used. may be installed by either or both. In this case, the thermoplastic resin of the thermoplastic resin layer 1 is a resin such as PETG that exhibits sufficient transparency, so that the metallic appearance of the aluminum layer 2 can be achieved through the thermoplastic resin layer 1. Well-presenting laminates and moldings are obtained.

Alternatively, the laminate of the present invention may be composed of the laminate 10 , the surface resin layer 4 and the second adhesive layer 5 . In this case, the laminate of the present invention can also be used as a sheet-like decorative body for exterior use, and can be molded in the same manner as the molded body 100 to obtain a decorative body for exterior use having a three-dimensional shape ( It can also be a molded product).

〔summary〕
As is clear from the above description, the metallic laminate (laminate 10) of the embodiment of the present invention comprises a thermoplastic resin layer (1), an aluminum layer (2) and an adhesive layer (first adhesive layer 3) are stacked in this order, the adhesive layer is composed of a polyester-based adhesive, and the curing index of the adhesive layer is 15 or more. Also, the metallic molded article (molded article 100) of the embodiment of the present invention is obtained by molding the metallic laminate (laminated article 20) as described above. Therefore, since the corrosion of the aluminum layer due to the intrusion of the alkaline solution from the periphery is sufficiently suppressed, the laminate and the molded body of the embodiment of the present invention can exhibit sufficient corrosion resistance of the aluminum layer to alkali.

In embodiments of the present invention, the cure index of the adhesive layer may be 30 or greater. This configuration is much more effective from the viewpoint of enhancing the alkali resistance of the laminate and molded article.

In an embodiment of the present invention, the thermoplastic resin layer may be composed of a polyester having benzene rings and cyclohexane rings in its main chain. This configuration is much more effective from the viewpoint of enhancing the formability of the laminate.

In an embodiment of the present invention, the laminate (20) further has a surface resin layer (4) that adheres to the adhesive layer, and the surface resin layer has transparency and weather resistance and is made of a thermoplastic resin. may be configured. This configuration is more effective from the viewpoint of clarifying the metallic appearance of the aluminum layer and from the viewpoint of enhancing weather resistance.

In an embodiment of the present invention, the laminate further comprises a further adhesive layer (second adhesive layer 5) and a substrate layer (6) further laminated in this order on the side of the thermoplastic resin layer opposite to the aluminum layer. , and the base layer may be made of a thermoplastic resin. This configuration is more effective from the standpoint of laminate moldability and from the standpoint of increasing the strength after molding.

An embodiment of the invention is described below.

[Preparation of adhesive]
Adhesives 1 to 8 below were prepared as adhesives for the adhesive layer. The adhesive 1 is "Byron GK-680" manufactured by Toyobo Co., Ltd. ("Byron" is a registered trademark of the same company). Adhesive 2 is "Vylon GK-590" manufactured by Toyobo Co., Ltd. The adhesive 3 is "TM-K76" manufactured by Toyo-Morton Co., Ltd. The adhesive 4 is "TM-K51" manufactured by Toyo-Morton Co., Ltd. The adhesive 5 is "Vylon GK-570" manufactured by Toyobo Co., Ltd. Adhesives 1 to 5 are all polyester (PES) adhesives.

The adhesive 6 is "Bontiter HUX-386" manufactured by ADEKA Corporation ("Bontiter" is a registered trademark of the same company). The adhesive 7 is "Rezamin UD-8336" ("Rezamin" is a registered trademark of Dainichiseika Kogyo Co., Ltd.). Both the adhesives 6 and 7 are polyurethane (PU) adhesives. The adhesive 6 is a water-based polyurethane adhesive, and the adhesive 7 is a solvent-based polyurethane adhesive to which a cross-linking agent is added.

The adhesive 8 is "Nisetsu SM412" ("Nisetsu" is a registered trademark of the same company) manufactured by Nippon Carbide Industry Co., Ltd. The adhesive 8 is an acrylic resin (AR)-based adhesive, and is a solvent-based acrylic resin-based adhesive.

Table 1 shows the type of resin, number polymerization average molecular weight Mn, glass transition temperature Tg, acid value and hydroxyl value of Adhesives 1 to 8. The physical property values listed in Table 1 are catalog values. The Mn of Adhesive 7 is not listed in Table 1 because no catalog value was found.

[Example 1]
An aluminum layer was formed by vapor-depositing aluminum on one side of a sheet of PETG, a transparent thermoplastic resin (condensation product of ethylene glycol, 1,4-cyclohexanedimethanol and terephthalic acid, appearance: transparent, thickness 19 μm). did. The thickness of the aluminum layer is 50 nm.

Next, polyisocyanate (xylylene diisocyanate composition, concentration 75%, isocyanate amount (NCO%) 14%) is mixed with adhesive 1, and this is applied to the surface of the aluminum layer on PETG with a bar coater. was applied so as to have a thickness of 7 μm to form a first adhesive layer. Thus, a laminated sheet having PETG, an aluminum layer and a first adhesive layer was produced. The thickness of the first adhesive layer is 7 μm. The first adhesive layer has a "hydroxyl equivalent cross-linking degree" of 1 and a curing index of 42.

Next, the surface of the first adhesive layer was pressed against the corona-treated surface of a transparent acrylic resin sheet (thickness: 75 μm, total light transmittance: 93%, breaking strength: 53 MPa) to form the surface resin layer. The acrylic resin sheet and the laminated sheet were laminated together. The "corona-treated surface" is one side of the transparent acrylic resin sheet that has been subjected to corona discharge treatment in order to enhance adhesion with the first adhesive layer.

Thus, a laminate 1 was produced in which the thermoplastic resin layer, the aluminum layer, the first adhesive layer and the surface resin layer were laminated in this order. When viewed from the surface resin layer side, the laminate 1 exhibits a metallic appearance with metallic luster due to the aluminum layer.

[Examples 2 to 4]
Laminates 2 to 4 were produced in the same manner as in Laminate 1, except that Adhesives 2 to 4 were used instead of Adhesive 1, respectively. The thickness of the first adhesive layer in Laminates 2 to 4 is all 7 μm.

[Examples 5 and 6]
Except that the amount of polyisocyanate added to the adhesive 1 is 0.75 times and 0.5 times, respectively, and the "degree of crosslinking of the hydroxyl value equivalent" in the first adhesive layer is 0.75 and 0.5, respectively. produced laminates 5 and 6 in the same manner as laminate 1. The cure index of the first adhesive layer in laminate 5 is 31.5, and the cure index of the first adhesive layer in laminate 6 is 21.0.

[Examples 7 and 8]
Except that the amount of polyisocyanate added to the adhesive 2 is 0.75 times and 0.5 times, respectively, and the "degree of crosslinking of the hydroxyl value equivalent" in the first adhesive layer is 0.75 and 0.5, respectively. produced laminates 7 and 8 in the same manner as laminate 2. The cure index of the first adhesive layer in laminate 7 is 25.5, and the cure index of the first adhesive layer in laminate 8 is 17.0.

[Examples 9 and 10]
Except that the amount of polyisocyanate added to the adhesive 4 is 0.75 times and 0.5 times, respectively, and the "degree of crosslinking of the hydroxyl value equivalent" in the first adhesive layer is 0.75 and 0.5, respectively. produced laminates 9 and 10 in the same manner as laminate 4. The cure index of the first adhesive layer in laminate 9 is 26.3, and the cure index of the first adhesive layer in laminate 10 is 17.5.

[Comparative Examples 1 to 4]
A laminate C1 was produced in the same manner as the laminate 1, except that the adhesive 5 was used instead of the adhesive 1. Laminates C2 to C4 were produced in the same manner as in Laminate 1, except that each of Adhesives 6 to 8 was used instead of Adhesive 1 without being mixed with polyisocyanate. The thickness of the first adhesive layer in each of the laminates C1 to C4 is 7 μm.

[Evaluation of alkali resistance]
For each of the laminates 1 to 10 and C1 to C4, a test piece was prepared by cutting the laminate into a size of 10 mm×10 mm. Next, the prepared test piece was immersed in a 0.1 N sodium hydroxide aqueous solution at room temperature (25° C.) for 8 hours. Next, the test piece was taken out from the sodium hydroxide aqueous solution, the state of dissolution of the aluminum layer was visually confirmed, and the dissolution distance was measured. The "dissolution distance" is the distance from the edge of the test piece into which the sodium hydroxide solution penetrated during immersion in the sodium hydroxide solution to the tip of the portion where the aluminum layer was dissolved. In this embodiment, the dissolution distance is defined as the distance from the edge of the layered body into which the sodium hydroxide aqueous solution penetrated to the tip (deepest part) of the part where the aluminum layer is dissolved to the innermost part.

〔Weatherability〕
An accelerated exposure test specified in Japanese Industrial Standards (JIS) A1415-2013 was performed for 3000 hours on each of the laminates 1 to 10 and C1 to C4. Then, the appearance of the laminate after the test was visually observed from the surface resin layer side by a plurality of skilled engineers to confirm changes in the appearance due to the test. As a result, the appearance of any of the laminates 1 to 10 and C1 to C4 after standing did not change substantially due to the above test, and it was confirmed that they have sufficient weather resistance for exterior applications such as automobiles. was done.

〔Heat-resistant〕
For each of the laminates 1 to 10 and C1 to C4, a white painted plate was attached to the surface of the PETG sheet opposite to the aluminum layer, left to stand at 80 ° C. for 168 hours, and the appearance of the laminate was viewed from the surface resin layer side. was observed visually. As a result, whitening, cracks and wrinkles were not observed in any of the laminates 1 to 10 and C1 to C4 after standing. Thus, the appearances of the laminates 1 to 10 and C1 to C4 do not substantially change before and after the standing, and it is confirmed that they have sufficient heat resistance for exterior applications such as automobiles. rice field.

〔Strength〕
The tensile elastic moduli of the laminates 1 to 10 and C1 to C4 are measured according to the test method specified in JIS K7127:1999 (ISO 527-3:1995). The thickness of each laminate is a design value of 101 μm, and the breakdown is 19 μm for the thermoplastic resin (PETG) layer, 7 μm for the first adhesive layer, and 75 μm for the surface resin (acrylic resin) layer. is. Each laminate has a tensile modulus of elasticity of around 1700 MPa, and it is confirmed that all of the above laminates have sufficient strength for exterior applications such as automobiles.

Table 2 shows the composition of each laminate, the resin type and curing index of the adhesive layer, and the dissolution distance in the laminate.

As shown in Table 2, the dissolution of the aluminum layers in the laminates 1 to 3 was a slight dissolution that was difficult to visually confirm. Further, the dissolution of the aluminum layer in the laminate 4 was visually confirmed, but the dissolution was small.

These results show that sandwiching the aluminum layer between the polyester-based adhesive and the PETG sheet improves the alkali resistance of the laminate. As a result, the dissolution distance can be suppressed to less than 0.8 mm in the alkali resistance evaluation test described above.

On the other hand, the dissolution of the aluminum layers in the laminates C1 to C3 was easily visually observed. Regarding the laminate C1, it is considered that the resin of the first adhesive layer is polyester, but its curing index is low. Regarding the laminates C2 and C3, it is considered that the resin of the first adhesive layer is polyurethane, so that the curing index is small and the adhesive strength of the adhesive layer is small.

The dissolution of the aluminum layer in the laminate C4 was more pronounced than in the other laminates. It is considered that this is because the adhesive strength of the first adhesive layer is small although the curing index of the adhesive is sufficiently large.

As is clear from the above results, when the adhesive material is polyester and the curing index of the adhesive is 30 or more, the immersion in the alkaline aqueous solution is irrespective of the numerical values of the acid value and hydroxyl value of the adhesive. It is possible to suppress the dissolution distance of the aluminum layer by less than 0.8 mm. The test conditions in the evaluation of alkali resistance described above are conditions corresponding to alkali erosion due to washing of automobiles.

Therefore, in the case of automotive exterior applications, if the laminate is provided with a 0.7 mm-wide edge, dissolution of the aluminum layer due to alkali can be practically suppressed. As a result, it is possible to prevent deterioration of the metallic appearance of the aluminum layer due to alkali corrosion. Further, the width of the edge can be set according to the evaluation result of the dissolution test, and can be set to be smaller than 0.7 mm, for example, within a range not less than the dissolution distance.

On the other hand, when the adhesive in the first adhesive layer of the laminate is an acrylic resin-based adhesive with a curing index greater than 30, or a polyurethane-based adhesive with a small curing index, , it can be seen that the adhesive strength of the first adhesive layer is small. Therefore, in the above case, the alkali solution penetrates into the interface between the aluminum layer and the first adhesive layer and dissolves the aluminum layer, so that the effect of suppressing corrosion of aluminum by alkali is small.

[Example 11]
The adhesive 1 was applied to the surface of the laminate 1 opposite to the surface resin layer (the surface of the PETG sheet opposite to the aluminum layer) so that the thickness after drying was 10 μm. After the second adhesive layer was formed in this manner, an ABS sheet (appearance: black, thickness: 200 μm) serving as the base layer was pressed against the second adhesive layer to bond the laminate 1 and the ABS sheet to the second adhesive layer. They were laminated via two adhesive layers. Thus, a laminate 11 was produced in which the surface resin layer, the first adhesive layer, the aluminum layer, the thermoplastic resin layer, the second adhesive layer and the substrate layer were laminated in this order.

Laminate 11 is placed in a pair of molds including one mold having a convex portion having a trapezoidal cross-sectional shape and the other mold having a corresponding concave portion, heated, and vacuum-formed. Thus, the laminate 11 was molded into a shape having a trapezoidal cross-sectional shape and edges as shown in FIG. Next, the tip of the edge was cut so that the width Lb of the edge was a desired width of more than 0.1 mm and less than 0.8 mm (for example, 0.7 mm). In this way, a molded article having a metallic appearance was produced.

The compact has, as mentioned above, very narrow edges, but with a width greater than the melt distance of the laminate 1 . Therefore, in the molded product, the outer appearance is hardly affected by the edges, and the aluminum layer inside the edges does not undergo alkali corrosion. Therefore, even if the molded article is used for the exterior of automobiles, the appearance is prevented from being damaged by the alkali corrosion during use.

Moreover, in the molding, both the first adhesive layer and the second adhesive layer are formed by applying the adhesive 1 . In this way, since the adhesives constituting both adhesive layers have the same composition, there is no loss of material that occurs in the coating process (resin accumulation in the coating machine, residual adhesive in the resin pan, etc.). ) can be prevented.

The present invention provides a molded article having a metallic appearance with an aluminum layer, regardless of interior or exterior, which has a small margin for alkali corrosion prevention despite having an aluminum layer, has alkali resistance and decorativeness. It can be used for excellent molded articles. In particular, the present invention is suitable for a decorative body for the exterior of mobile bodies such as automobiles.

1 thermoplastic resin layer 2 aluminum layer 3 first adhesive layer (adhesive layer)
4 surface resin layer 5 second adhesive layer (additional adhesive layer)
6 base material layer 10, 20 laminated body 100 molded body 101 convex part 102 edge part

Claims (6)

A thermoplastic resin layer, an aluminum layer and an adhesive layer are stacked in this order,
The adhesive layer is composed of a polyester-based adhesive,
A metallic laminate, wherein the curing index of the adhesive layer calculated from the following formula is 15 or more.
(formula)
Cure index = acid value x hydroxyl value x hydroxyl value equivalent cross-linking degree (in the above formula, “acid value” is the acid value (mgKOH/g) of the polyester adhesive, and “hydroxyl value” is the polyester is the hydroxyl value (mgKOH/g) of the adhesive, and the "degree of crosslinking of the hydroxyl value equivalent" is the ratio of the hydroxyl groups of the polyester of the polyester adhesive used for crosslinking in the adhesive layer.) 2. The metallic laminate according to claim 1, wherein the adhesive layer has a curing index of 30 or more. 3. The metallic laminate according to claim 1, wherein said thermoplastic resin layer is made of a polyester having a benzene ring and a cyclohexane ring in its main chain. It further has a surface resin layer that adheres to the adhesive layer,
4. The metallic laminate according to claim 1, wherein the surface resin layer has transparency and weather resistance and is composed of a thermoplastic resin. A further adhesive layer and a base material layer are further overlaid in this order on the side of the thermoplastic resin layer opposite to the aluminum layer,
5. The metallic laminate according to claim 4, wherein the base material layer is made of a thermoplastic resin. A metallic molded article obtained by molding the metallic laminate according to any one of claims 1 to 5.

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