JP2022027639A - Decorative sheet - Google Patents

Abstract

To provide a decorative sheet which has a simple configuration and can be inexpensively manufactured, has high designability, and has good adhesion between a transparent resin layer and a base material layer.SOLUTION: A decorative sheet 1 has a base material layer 10, a printing layer 20 partially printed on the base material layer 10, and a transparent resin layer 30 laminated on the base material layer 10 across the printing layer 20. The printing layer 20 has a thickness of 3 μm or more and 12 μm or less, at least a part thereof is embedded in the base material layer 10, and storage elastic modulus at 165°C of the base material layer 10 is smaller than storage elastic modulus at 165°C of the transparent resin layer 30.SELECTED DRAWING: Figure 1

Description

The present invention relates to a decorative sheet that decorates an article by being attached to the article.

Conventionally, a decorative sheet attached to the surface of an article has been used for decorating furniture, fittings, and the like. Further, in recent years, there is an increasing demand for decorative sheets (wrapping sheets) having a pattern for decorating automobile exteriors.
In the decorative sheet having a pattern, a print layer corresponding to the pattern of the pattern is partially formed on the base material layer, and the design of the print layer imparts design.
Patent Documents 1 to 3 disclose decorative sheets in which a printing layer is partially formed on a base material layer.

International Publication No. 2007/116942 Japanese Unexamined Patent Publication No. 3-224736 Japanese Unexamined Patent Publication No. 2006-239926

Here, in the decorative sheet on which the pattern is printed, it is necessary to laminate the transparent resin layer on the surface layer side (the side where the printing layer is provided) in order to improve the durability. However, since the print layer on which the pattern is printed is partially provided, the following problems arise depending on the layer thickness of the print layer portion.

In order to improve the design, it is basically desirable that the print layer has a thick layer thickness. However, if the print layer is made too thick, the step at the boundary between the portion where the print layer is provided and the portion other than the print layer becomes large. The transparent resin layer is provided by thermal laminating on the base material layer on which the printing layer is provided, and at that time, voids are generated at the end of the printing layer where a step is generated in the printing layer, and the adhesion is increased accordingly. There is concern about a decline.
On the other hand, if the print layer is made too thin in order to suppress the generation of the above-mentioned voids, there is a concern that the concealing property of the base may be insufficient, the depth of the color or pearl may be insufficient, and the design may be deteriorated. ..

Further, as a countermeasure against the above-mentioned problems, it is conceivable to provide an adhesive layer or an adhesive layer between the base material layer and the transparent resin layer in order to fill the step. However, in that case, the manufacturing process becomes complicated and the number of materials increases, which raises a new problem that the cost increases and the followability of the transparent resin layer to the deformation of the base material also decreases. It is also necessary to consider the environmental resistance of the adhesive layer and the adhesive layer.

An object of the present invention is to provide a decorative sheet which can be manufactured at low cost with a simple structure, has a high design, and has good adhesion between a transparent resin layer and a base material layer. ..

The present invention solves the above-mentioned problems by the following solution means. In addition, in order to facilitate understanding, the description will be given with reference numerals corresponding to the embodiments of the present invention, but the present invention is not limited thereto.

In the first invention, a base material layer (10), a partially printed print layer (20) arranged on top of the base material layer (10), and the print layer (20) are sandwiched between the base material layer (10) and the partially printed print layer (20). A decorative sheet (1) including a transparent resin layer (30) laminated on the base material layer (10), wherein the printed layer (20) has a thickness of 3 μm or more and 12 μm or less, and is at least. A part of the substrate layer (10) is embedded in the substrate layer (10), and the storage elastic modulus of the substrate layer (10) at 165 ° C. is smaller than the storage elastic modulus of the transparent resin layer (30) at 165 ° C. It is a decorative sheet (1).

The second invention is the decorative sheet (1) according to the first invention, wherein the storage elastic modulus of the base material layer (10) at 165 ° C. is 1.5 MPa or less. Is.

The third invention is the decorative sheet (1) according to the first invention or the second invention, wherein the base material layer (10) is a polyester-based plasticizer with respect to 100 parts by mass of a vinyl chloride-based resin. Is a decorative sheet (1) containing 31 parts by mass or more and 45 parts by mass or less.

The fourth invention is the decorative sheet (1) according to any one of the first to third inventions, wherein the transparent resin layer (30) contains an acrylic resin and the printing layer (20). ) Is a decorative sheet (1) containing an acrylic resin.

A fifth aspect of the invention is the decorative sheet (1) according to any one of the first to fourth inventions, wherein the printed layer (20) is entirely embedded in the base material layer (10). It is a decorative sheet (1).

The sixth invention is the decorative sheet (1) for the vehicle body of an automobile in the decorative sheet (1) according to any one of the first to fifth inventions.

The seventh invention is the method for producing a decorative sheet according to any one of the first invention to the sixth invention, which is on the base material layer (10) or the transparent resin layer (30). A step of forming the printed layer (20) and a step of thermally laminating the transparent resin layer (30) on the base material layer (10) with the printed layer (20) at a temperature of 150 ° C. or higher and 170 ° C. or lower. It is a method of manufacturing a decorative sheet provided with.

According to the present invention, it is possible to provide a decorative sheet which can be manufactured at low cost with a simple structure, has a high design, and has good adhesion between a transparent resin layer and a base material layer. ..

It is sectional drawing which shows the embodiment of the decorative sheet 1 by this invention. It is a figure explaining the manufacturing method of the decorative sheet 1. It is sectional drawing of the decorative sheet 100 in which a printing layer 20 is not embedded in the base material layer 10 side. It is a figure which shows the comparative evaluation result. It is a figure which shows the micrograph which took the cross section of the decorative sheet 1. It is sectional drawing which shows the embodiment of the decorative sheet 2 by this invention.

Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings and the like.

(Embodiment)
FIG. 1 is a cross-sectional view showing an embodiment of the decorative sheet 1 according to the present invention.
In addition, each figure shown below including FIG. 1 is a diagram schematically shown, and the size and shape of each part are shown by exaggerating or omitting them as appropriate for easy understanding. ing.
Further, in the following description, specific numerical values, shapes, materials and the like will be described, but these can be changed as appropriate.
It should be noted that the specific numerical values specified in the present specification and the claims should be treated as including a general error range. That is, a difference of about ± 10% is substantially the same, and a value set in a range slightly beyond the numerical range of the present invention is substantially the same as that of the present invention. It should be interpreted as being within the range.

The decorative sheet 1 of the present embodiment can impart excellent designability and weather resistance to an adherend having a three-dimensional curved surface. This decorative sheet is preferably used for the body of an automobile, but is not limited to this, and is not limited to this, and is not limited to this, and is used as a cover material for indoor or outdoor (exterior) vehicles such as railroad vehicles, ships, and aircraft, various signs, and panels for outdoor advertisements. In addition to materials, it also applies to building wall materials (exterior materials, interior materials), partitions, doors, window frames and other fittings, desks, dining tables, cupboards, counter tables, sinks, furniture, interior decorations, etc. be able to.
The decorative sheet 1 of the present embodiment includes a base material layer 10, a printing layer 20, a transparent resin layer 30, and an adhesive layer 40. Further, the decorative sheet 1 of the present embodiment is a decorative sheet for manual attachment that is manually attached to the object.

<Base layer>
The storage elastic modulus of the base material layer 10 at 165 ° C. is smaller than the storage elastic modulus of the transparent resin layer 30 at 165 ° C. As a result, the base material layer 10 is more easily deformed than the transparent resin layer 30 when it is thermally laminated, which will be described later. By heat laminating in this state, the print layer 20 is embedded in the base material layer 10 side. The base material layer 10 is not limited to being colorless and transparent, and may contain a colorant.

The storage elastic modulus of the base material layer 10 at 165 ° C. is such that the storage elastic modulus (E') measured at a frequency of 10 Hz and a temperature of 165 ° C. by dynamic viscoelasticity measurement is 0.2 MPa or more and 1.5 MPa or less. preferable. When it is 0.2 MPa or more, the base material layer 10 is not too soft and the strength as the base material layer 10 tends to be sufficient, and when it is 1.5 MPa or less, the base material layer 10 is not too hard and printing is performed. The embedding of the layer 20 tends to be sufficient. In the present specification, the storage elastic modulus at 165 ° C. conforms to JIS K 7244-4: 1999, and the frequency is set to 10 Hz by a dynamic elastic modulus measuring device (DVA-225 manufactured by IT Measurement Control Co., Ltd.). The values were measured with a temperature of 165 ° C, a temperature rise rate of 5 ° C / min, a sample width of 5 mm, a chuck distance of 10 mm, an upper limit elongation rate of 200%, and a minimum load of 1 mN. The same value is obtained with.

The storage elastic modulus of the base material layer 10 can be determined by, for example, optimizing the type and amount of the plasticizer of the vinyl chloride resin, changing the type of the resin, and optimizing the density and molecular weight of the resin. Can be adjusted to a range. In this embodiment, a base material layer 10 containing 31 parts by mass, 39 parts by mass, and 45 parts by mass of a polyester-based plasticizer is used in 100 parts by mass of polyvinyl chloride of 150 μm.

The vinyl chloride resin is mainly polyvinyl chloride (PVC) obtained by polymerizing a vinyl chloride monomer, but in addition, the following copolymers obtained by copolymerizing a vinyl chloride monomer and another monomer are also available. Can be used. Examples of the monomer copolymerizable with the vinyl chloride monomer include vinyl esters such as vinyl acetate and vinyl propionate; acrylic acid esters such as methyl acrylate and butyl acrylate; and methacrylate esters such as methyl methacrylate and ethyl methacrylate; butyl malate and the like. Maleic acid esters such as diethyl malate; Fumaric acid esters such as dibutyl fumarate and diethyl fumarate; Vinyl ethers such as vinyl methyl ether, vinyl butyl ether and vinyl octyl ether; Vinyl cyanide such as acrylonitrile and methacrylonitrile Olefins such as ethylene, propylene, butylene and styrene; Dienes such as isoprene and butadiene; Vinylidene halides other than vinyl chloride such as vinylidene chloride and vinyl bromide, vinyl halides; Allyl phthalates such as diallylphthalate , Etc. can be mentioned. These monomers may be used alone or in combination of two or more.

Further, as the vinyl chloride resin, a graft copolymer obtained by grafting a vinyl chloride monomer to the following polymer can also be used. As the polymer to which the vinyl chloride monomer is grafted, ethylene-vinyl acetate copolymer, ethylene-vinyl acetate-carbon monoxide copolymer, ethylene-ethyl acrylate copolymer, ethylene-ethyl acrylate-carbon monoxide copolymer , Ethylene-methylmethacrylate copolymer, ethylene-propylene copolymer and the like.

The average degree of polymerization of the vinyl chloride resin is preferably 500 to 4000, more preferably 700 to 3900, and even more preferably 1000 to 3800. When the average degree of polymerization is within the above range, excellent mechanical strength can be obtained and excellent moldability can be obtained. The average degree of polymerization is an average degree of polymerization measured in accordance with JIS K6721.

A plasticizer is added to the vinyl chloride resin used as the base material layer 10 in order to exhibit the embedding property of the printing layer 20, and the storage elastic modulus, hardness, elastic modulus and the like are adjusted. The plasticizer is not particularly limited as long as it is compatible with the vinyl chloride resin, and is, for example, dibutyl phthalate (DBP), dioctyl phthalate (DOP), diisononyl phthalate (DINP), diisodecyl phthalate (Plasticizer). DIDP), phthalic acid plasticizers such as diundecyl phthalate (DUP); adipic acid plasticizers such as dibutyl adipate; phosphoric acid plasticizers such as tributyl phosphate, tricresyl phosphate, triphenyl phosphate; trimerits Trimellitic acid-based plasticizers such as tributyl acid and trioctyltrimellitic acid; various known polyester-based plasticizers such as adipic acid-based polyester; citrate esters such as acetyltributylcitrate and acetyltrioctylcitrate; and the like can be mentioned. However, a polyester plasticizer is particularly preferable. These plasticizers may be used alone or in combination of two or more.

As the adipic acid-based polyester plasticizer, those having a weight average molecular weight of 1,000 or more and 3,000 or less are preferably used. The adipic acid-based polyester plasticizer is a reaction product of adipic acid and a dihydric alcohol, and examples of the dihydric alcohol include ethylene glycol, propylene glycol, butanediol, and 1,6-hexanediol. These dihydric alcohols may be used alone or in combination of two or more. Specific examples of the adipic acid-based polyester plasticizer include poly (propylene glycol, adipic acid) ester, poly (butanediol, adipic acid) ester, poly (ethylene glycol, adipic acid) ester, and poly (1,6-hexane). Examples thereof include diol, butanediol, adipic acid) ester, poly (butanediol, ethylene glycol, adipic acid) ester, poly (ethylene glycol, propylene glycol, butanediol, adipic acid) ester and the like. By using a polymer-based plasticizer having a weight average molecular weight of 1,000 or more and 3,000 or less, the adipic acid-based polyester plasticizer can exhibit the embedding property of the print layer 20 and suppress bleed-out.

The content of the plasticizer is preferably 31 parts by mass or more and 45 parts by mass or less, more preferably 34 parts by mass or more and 40 parts by mass or less with respect to 100 parts by mass of the vinyl chloride resin, and particularly preferably. It is 37 parts by mass or more and 39 parts by mass or less. By setting the content of the plasticizer to 31 parts by mass or more, the vinyl chloride resin is made flexible and the printing layer 20 can be embedded. On the other hand, when the content is 45 parts by mass or less, the strength of the base material layer 10 can be maintained and the bleed-out of the plasticizer can be suppressed.

Examples of the resin other than the vinyl chloride resin used as the base material layer 10 include thermoplastic polyurethane (TPU), PVA, EVA and the like.

The thickness of the base material layer 10 is preferably 80 or less and 180 μm or less. The setting of 80 μm or more and 180 μm or less is advantageous in terms of bending workability such as wrapping work. The base material layer 10 may be colored.

<Print layer>
The print layer 20 is a design layer on which the design of the decorative sheet 1 is formed. Examples of the binder resin constituting the printing layer 20 include an acrylic resin, a vinyl chloride-vinyl acetate copolymer resin, and an acrylic- (vinyl chloride-vinyl acetate copolymer) resin. Among them, from the viewpoint of embedding in the base material layer 10, it is preferable to contain an acrylic resin having a higher storage elastic modulus and hardness than the above-mentioned base material layer 10. In this case, since the base material layer 10 can be softly adjusted so that the print layer 20 can be embedded in the base material layer 10, it is necessary to include a photocurable component as the print layer as in Patent Document 1. do not have. As a result, a normal print layer can be used, and a photocuring step is not required.

As described above, since the printing layer 20 can be embedded in the base material layer 10 by adjusting the base material layer 10 softly, the storage elastic modulus of the printing layer 20 at 165 ° C. is not particularly limited, but the base material layer. It is preferably larger than the storage elastic modulus of 10 at 165 ° C. The storage elastic modulus of the printed layer 20 at 165 ° C. is preferably 2 MPa or more and 15 MPa or less. When it is 2 MPa or more, the print layer 20 is easily embedded in the base material layer 10, and when it is 15 MPa or less, it is easy to prevent the print layer 20 from cracking during wrapping.

The storage elastic modulus of the printed layer 20 at 165 ° C. can be adjusted, for example, by adjusting the molecular weight of the binder resin or, when a plurality of binder resins are used, adjusting the blending ratio thereof.

Various coloring pigments, coloring dyes and the like are added to the printing layer 20. The print layer 20 can be formed by, for example, screen printing, gravure printing, or the like. In the present embodiment, the printing layer 20 is partially formed by applying a printing ink using a mixed resin of a vinyl chloride-vinyl acetate copolymer and an acrylic resin as a binder onto the base material layer 10 by a gravure printing method. ing. The print layer 20 has a thickness of 3 μm or more and 12 μm or less. Further, it is desirable that the thickness of the print layer 20 is 6 μm or more. In this specification, the thickness of the print layer means the maximum value when any 20 points are measured.

The thickness of the printed layer embedded in the base material layer 10 is, for example, 1 to 10 μm.
The thickness of the printing layer existing in the transparent resin layer 30 is preferably 3 μm or less, more preferably 2 μm or less. Within this numerical range, the effect of the present invention can be obtained better.

<Transparent resin layer>
The transparent resin layer 30 is a transparent resin layer laminated on the base material layer 10 with the print layer 20 interposed therebetween, and is provided to protect the print layer 20.

The transparent resin layer 30 is required to have a higher storage elastic modulus and hardness than the above-mentioned base material layer 10, whereby the printed layer 20 is embedded in the base material layer 10. From this point of view, the transparent resin layer 30 preferably contains an acrylic resin. The thickness of the transparent resin layer 30 is preferably 30 μm or more and 100 μm or less, and more preferably 40 μm or more and 90 μm or less.

The acrylic resin is not particularly limited as long as it is a resin that can form a film or a sheet by the calendar method, and a known acrylic resin can be appropriately selected and used. Specific examples thereof include a polymer or copolymer of methacrylic acid or methacrylic acid ester represented by polymethyl (meth) clelate (PMMA), a copolymer of alkyl methacrylate, alkyl acrylate and styrene, and the like. ..

The transparent resin layer 30 may have a two-layer structure of an acrylic resin layer located on the base material layer side and a fluororesin-containing layer located on the surface side. The fluororesin means a polymer containing a monomer containing a fluorine atom as a polymerization component. Examples of the fluororesin include a resin composed of a polymerization component selected from ethylene tetrafluoride, ethylene trifluoride, vinyl fluoride, and vinylidene fluoride. More specifically, the fluororesin in the present invention includes a homopolymer of a polymerization component containing a fluorine atom such as a tetrafluoroethylene resin, a vinyl fluoride resin, and a vinylidene fluoride resin, and a co-weight containing the polymerization component. Examples thereof include a combination of ethylene trifluoride chloride-vinylidene fluoride copolymer, vinylidene fluoride-6 propylene fluoride copolymer, vinylidene fluoride-6 propylene fluoride-4 ethylene fluoride copolymer and the like. The thickness of the fluororesin-containing layer 16 is preferably 3 μm or more and 20 μm or less, and more preferably 5 μm or more and 15 μm or less.

As the transparent resin layer 30 of the present embodiment, for example, a commercially available laminate in which an acrylic resin layer and a fluororesin layer are laminated by coextrusion can be used, and such a laminated film can be used. For example, acrylic FBS006 manufactured by Mitsubishi Chemical Corporation, FT-50Y manufactured by Kureha Corporation, DX film manufactured by Denka Corporation, and the like can be used.

The storage elastic modulus of the transparent resin layer 30 at 165 ° C. is larger than the storage elastic modulus of the base material layer 10 at 165 ° C. As a result, the print layer 20 is embedded in the base material layer 10. Specifically, the storage elastic modulus (E') measured at a frequency of 10 Hz and a temperature of 165 ° C. by dynamic viscoelasticity measurement is preferably 4 MPa or more and 15 MPa or less. When it is 4 MPa or more, the transparent resin layer 30 is not too soft, and the printing layer 20 tends to be sufficiently embedded in the base material layer 10. When it is 15 MPa or less, the processability and shape followability at the time of thermal laminating tend to be good. The storage elastic modulus can be measured by a conventionally known dynamic elastic modulus measuring device (DMA).

The storage elastic modulus of the transparent resin layer 30 can be adjusted to the above range by, for example, changing the type of resin or optimizing the density and molecular weight of the resin.

<Adhesive layer>
The adhesive layer 40 is a layer of an adhesive for adhering the decorative sheet 1 to an article. The pressure-sensitive adhesive used for the pressure-sensitive adhesive layer 40 is not particularly limited, and for example, rubber-based, acrylic-based, olefin-based, polyester-based, polyurethane-based, and the like can be used. If necessary, a separator may be provided which is temporarily bonded to the adhesive layer 40 to cover it.

Next, a method of manufacturing the decorative sheet 1 will be described.
FIG. 2 is a diagram illustrating a method for manufacturing the decorative sheet 1.
First, the print layer 20 is printed on one surface (upper surface in FIG. 2) of the base material layer 10 and dried (FIG. 2 (a)).

Next, a crimping roller (not shown) heated to a temperature of 150 ° C. or higher and 170 ° C. or lower with a transparent resin sheet to be the transparent resin layer 30 stacked on the side provided with the printing layer 20 (FIG. 2B). The base material layer 10 and the transparent resin layer 30 are thermally laminated through the space.
Here, the storage elastic modulus of the base material layer 10 in the present embodiment at 165 ° C. is 1.1 MPa. The storage elastic modulus of the transparent resin layer 30 at 165 ° C. is 4.7 MPa. That is, the storage elastic modulus of the base material layer 10 at 165 ° C. is smaller than the storage elastic modulus of the transparent resin layer 30 at 165 ° C. Therefore, the base material layer 10 is more easily deformed than the transparent resin layer 30 when it is thermally laminated. By heat laminating in this state, the print layer 20 is embedded in the base material layer 10 side.
By setting the temperature of the thermal laminating to 150 ° C. or higher, the laminating strength becomes high, and the transparent resin layer 30 is difficult to peel off from the base material layer 10 when the decorative sheet 1 is stretched and bonded to the object. Become. Further, by setting the temperature of the thermal laminating to 170 ° C. or lower, the base material layer 10 can be made more easily deformed than the transparent resin layer 30, so that the print layer 20 can be embedded on the base material layer 10 side. ..

FIG. 3 is a cross-sectional view of the decorative sheet 100 in which the printing layer 20 is not embedded in the base material layer 10 side.
As shown in FIG. 3, in the decorative sheet 100, the printing layer 20 is not embedded in the base material layer 10 side. In such a state, since the step due to the protrusion of the print layer 20 is large, the print layer 20 may be thermally laminated with the gap 21 remaining in the vicinity of the end portion. If the void 21 remains, the adhesion will be lowered accordingly.
On the other hand, in the decorative sheet 1 of the present embodiment, at least a part of the printing layer 20 is embedded in the base material layer 10, so that the amount of protrusion of the printing layer 20 toward the transparent resin layer 30 side is reduced. As a result, no voids remain after thermal laminating. The amount of the printed layer 20 embedded in the base layer 10 side varies depending on the storage elastic modulus of the base layer 10 and the transparent resin layer 30, but 40% or more of the thickness of the printed layer 20 is on the base layer 10 side. It is desirable to be embedded in the to prevent the formation of voids. Further, as in the decorative sheet 2 shown in FIG. 6, the entire printing layer 20 may be embedded in the base material layer 10 side.

Next, the present invention will be described in more detail with reference to a plurality of examples and comparative examples. However, the present invention is not limited to the following examples.

(Example 1)
As the base material layer 10, a vinyl chloride resin having a thickness of 150 μm (storage elastic modulus at 165 ° C.: 1.1 MPa) containing a plasticizer was used. As the plasticizer, 39 parts by mass of a polyester-based plasticizer was added to 100 parts by mass of a vinyl chloride-based resin. Gravure printing is performed on one surface of the base material layer 10 using a printing ink (storage elasticity at 165 ° C.: 3.0 MPa) using a mixed resin of a vinyl chloride-vinyl acetate copolymer and an acrylic resin as a binder. This was done to form the print layer 20.
A transparent resin layer 30 with a thickness of 50 μm in which an acrylic resin layer 45 μm and a fluororesin layer 5 μm are co-extruded and laminated on the surface on the printed layer 20 side (FBS007 manufactured by Mitsubishi Chemical Corporation, storage elastic modulus at 165 ° C.: 4). A decorative sheet was prepared by thermally laminating (0.7 MPa) at a set temperature of 165 ° C. The roll material was metal, and the sheet width was 1300 mm, pressed at 2.5 tons, and heat-laminated on the acrylic resin layer side and the print layer 20 side.
The thickness of the printed layer 20 of the prepared decorative sheet was 12 μm.

(Example 2)
A decorative sheet having a printing layer 20 thickness of 6 μm was produced under the same materials and conditions as in Example 1 except that the thickness of the printing ink was changed in gravure printing.

(Example 3)
A decorative sheet having a print layer 20 thickness of 3 μm was produced under the same materials and conditions as in Example 1 except that the thickness of the printing ink was changed in gravure printing.

(Example 4)
As the base material layer 10, a vinyl chloride resin having a thickness of 150 μm (storage elastic modulus at 165 ° C.: 1.4 MPa) in which 31 parts by mass of a polyester plasticizer was added to 100 parts by mass of the vinyl chloride resin was used. A decorative sheet was prepared with the same materials and conditions as in Example 2 except for the above.

(Example 5)
As the base material layer 10, a vinyl chloride resin having a thickness of 150 μm (storage elastic modulus at 165 ° C.: 0.8 MPa) was used, in which 45 parts by mass of a polyester plasticizer was added to 100 parts by mass of the vinyl chloride resin. A decorative sheet was prepared with the same materials and conditions as in Example 2 except for the above.

(Example 6)
A decorative sheet was prepared under the same materials and conditions as in Example 5 except that a transparent resin layer 30 having an acrylic resin layer of 50 μm (HBS006H manufactured by Mitsubishi Chemical Corporation, storage elastic modulus at 165 ° C.: 1.0 MPa) was used. ..

(Comparative Example 1)
A decorative sheet having a printing layer 20 thickness of 15 μm was produced under the same materials and conditions as in Example 1 except that the thickness of the printing ink was changed in gravure printing.

(Comparative Example 2)
A decorative sheet having a print layer 20 thickness of 2 μm was produced under the same materials and conditions as in Example 1 except that the thickness of the printing ink was changed in gravure printing.

(Comparative Example 3)
A decorative sheet was prepared under the same materials and conditions as in Example 2 except that PET having a thickness of 100 μm (storage elastic modulus at 165 ° C.: 590 MPa) was used as the base material layer 10.

(Comparative Example 4)
As the base material layer 10, a vinyl chloride resin having a thickness of 120 μm (storage elasticity at 165 ° C.: 2.0 MPa) in which 28 parts by mass of a polyester plasticizer was added to 100 parts by mass of the vinyl chloride resin was used. , Except for using a transparent resin layer 30 (manufactured by Denka Co., Ltd., DX-14S0250, storage elasticity at 165 ° C.: 1.3 MPa) in which an acrylic resin layer and a fluororesin layer are co-extruded and laminated. Made a decorative sheet with the same materials and conditions as in Example 2.

(Comparative Example 5)
As the base material layer 10, a vinyl chloride resin having a thickness of 120 μm (storage elasticity at 165 ° C.: 2.0 MPa) in which 28 parts by mass of a polyester plasticizer was added to 100 parts by mass of the vinyl chloride resin was used. , A decorative sheet was prepared with the same materials and conditions as in Example 2 except that a transparent resin layer 30 having an acrylic resin layer of 50 μm (HBS006H manufactured by Mitsubishi Chemical Corporation, storage elasticity at 165 ° C.: 1.0 MPa) was used. did.

FIG. 4 is a diagram showing a comparative evaluation result.
In the background hiding property evaluation column in FIG. 4, 〇 indicates that the background is sufficiently concealed by the print layer, and Δ indicates that the background is slightly visible through the print layer but is sufficiently usable. In x, the background is clearly visible through the print layer and cannot be used.
Further, in the evaluation column of defects during laminating in FIG. 4, ◯ indicates that there is no air bubbles mixed in the laminated surface and there is no problem in adhesion, and Δ indicates that air bubbles (voids) are mixed in with a microscope, but the design. There is no problem with the property and adhesion, and x indicates that air bubbles (voids) are mixed with the naked eye and there is poor adhesion.

From the evaluation results of FIG. 4, it can be said that if the thickness of the print layer 20 is 3 μm or more, the designability can be kept good. Further, if the thickness of the print layer 20 is 12 μm or less, it can be said that thermal laminating can be performed with almost no air bubbles mixed in.
Further, from the comparison between the results of Comparative Examples 3 to 5 and the examples, the effect of having the storage elastic modulus of the base material layer 10 at 165 ° C. being smaller than the storage elastic modulus of the transparent resin layer 30 at 165 ° C. is sufficiently sufficient. It was confirmed that it was exhibited.

FIG. 5 is a diagram showing a micrograph of a cross section of the decorative sheet 1. Note that FIG. 5 is upside down from FIGS. 1 to 3 above.
In the decorative sheet 1 illustrated in FIG. 5, the base material layer 10 is a PVC having a thickness of 150 μm, and the transparent resin layer 30 is a laminated acrylic resin film (45 μm) and a fluororesin film (5 μm) having a thickness of 50 μm. The printed layer 20 has a thickness of 6 μm, which corresponds to the second embodiment of FIG.
As shown in FIG. 5, in the decorative sheet 1 of the present embodiment, it was confirmed that the entire printing layer 20 was embedded in the base material layer 10.

(Reference example)
A decorative sheet was produced in the same manner as in Example 2 except that the set temperature of the thermal laminate was set to 145 ° C, 155 ° C, 165 ° C, and 175 ° C. The laminating strength (adhesion) of the transparent resin layer 30 and the base material layer 10 of the prepared decorative sheet was confirmed. The decorative sheet produced by thermal laminating at a set temperature of 145 ° C. had an interface fracture at the interface between the transparent resin layer 30 and the base material layer 10, and the laminating strength was weak. The decorative sheet produced by thermal laminating at a set temperature of 155 ° C., 165 ° C., and 175 ° C. was coagulated and fractured inside the transparent resin layer 30 or the base material layer 10, and the laminating strength was strong. The laminating strength (adhesion) was confirmed by the following procedure. Prior to thermal laminating, an adhesive tape (Nichiban cellophane tape (registered trademark)) is attached to a part of the surface of the base material layer 10 on the side to be joined to the transparent resin layer 30. The base material layer 10 to which the adhesive tape is attached and the transparent resin layer 30 are laminated and heat-laminated. The surface of the base material layer 10 to which the adhesive tape is attached is not bonded to the transparent resin layer 30, and the surface of the base material layer 10 to which the adhesive tape is not attached is bonded to the transparent resin layer 30. After a certain period of time has passed since the heat laminating, hold the portion of the transparent resin layer 30 that is not bonded to the base material layer 10 and slowly 180 toward the portion of the transparent resin layer 30 that is bonded to the base material layer 10. ℃ Peel off.

In the decorative sheet produced by thermal laminating at a set temperature of 145 ° C., 155 ° C., and 165 ° C., most of the printed layer 20 (70% or more of the whole) was embedded in the base material layer 10. In the decorative sheet produced by thermal laminating at a set temperature of 175 ° C., a part of the printing layer 20 was not embedded in the base material layer 10. The transparent resin layer 30 of Example 2 has a storage elastic modulus of 2.4 MPa at 145 ° C., a storage elastic modulus of 5.4 MPa at 155 ° C., and a storage elastic modulus of 4.7 MPa at 165 ° C. The rate was 0.8 MPa. Further, the base material layer 10 of Example 2 has a storage elastic modulus of 1.8 MPa at 145 ° C., a storage elastic modulus of 1.4 MPa at 155 ° C., and a storage elastic modulus of 1.1 MPa at 165 ° C. The rate was 0.8 MPa. In the decorative sheet produced by thermal laminating at a set temperature of 175 ° C., a part of the printing layer 20 was not embedded in the base material layer 10, but in the above evaluation, strong laminating strength (adhesion) was obtained. ing. However, from the viewpoint of long-term reliability, it is preferable that most of the printed layer 20 (70% or more of the whole) is embedded in the base material layer 10.

From the above reference example, focusing on the storage elastic modulus of the transparent resin layer 30 and the base material layer 10 at 165 ° C., the storage elastic modulus of the base material layer 10 at 165 ° C. is changed to the storage elastic modulus of the transparent resin layer 30 at 165 ° C. By thermally laminating the transparent resin layer 30 and the base material layer 10 at a set temperature of 150 ° C. or higher and 170 ° C. or lower, the laminating strength is strong, and most of the printed layer 20 is formed on the base material layer 10. It can be seen that an embedded decorative sheet with good adhesion can be obtained. Decorative sheets with good adhesion are important for ensuring durability in outdoor environments for exterior applications of vehicles such as automobiles and railway bodies. It is important for decorative sheets other than exterior applications to have durability that can be used in a variety of usage environments.

In the above-mentioned manufacturing method, a step of printing the printing layer 20 on the surface of the base material layer 10 and then heat-laminating the printing layer 20 with the transparent resin layer 30 has been described. The method for manufacturing the decorative sheet 1 is not limited to this, and may be a step of printing the printing layer 20 on the surface of the transparent resin layer 30 and then thermally laminating the printing layer 20 with the base material layer 10.

As described above, according to the decorative sheet 1 of the present embodiment, since the printing layer 20 is embedded in the base material layer 10, the design is high, and the base material layer 10 and the transparent resin layer 30 are combined. A decorative sheet having good adhesion between the sheets can be obtained. Further, the decorative sheet 1 of the present embodiment can be manufactured at low cost with a simple structure because it is not necessary to provide an adhesive layer or the like between the base material layer 10 and the transparent resin layer 30.

1, 2 Decorative sheet 10 Base material layer 20 Printing layer 21 Void 30 Transparent resin layer 40 Adhesive layer 100 Decorative sheet (comparative example)

Claims (7)

With the base material layer,
A printed layer that is arranged on top of the base material layer and partially printed,
A transparent resin layer laminated on the base material layer with the printing layer interposed therebetween
It is a decorative sheet equipped with
The printed layer has a thickness of 3 μm or more and 12 μm or less, and at least a part thereof is embedded in the base material layer.
A decorative sheet in which the storage elastic modulus of the base material layer at 165 ° C. is smaller than the storage elastic modulus of the transparent resin layer at 165 ° C. In the decorative sheet according to claim 1,
The storage elastic modulus of the base material layer at 165 ° C. is 1.5 MPa or less.
Decorative sheet. In the decorative sheet according to claim 1 or 2.
The base material layer contains 31 parts by mass or more and 45 parts by mass or less of a polyester-based plasticizer with respect to 100 parts by mass of the vinyl chloride resin.
Decorative sheet. In the decorative sheet according to any one of claims 1 to 3.
The transparent resin layer contains an acrylic resin and contains
The print layer contains an acrylic resin.
Decorative sheet. In the decorative sheet according to any one of claims 1 to 4.
The printed layer is entirely embedded in the base material layer.
Decorative sheet. In the decorative sheet according to any one of claims 1 to 5.
Decorative sheet for the body of an automobile. The method for manufacturing a decorative sheet according to any one of claims 1 to 6.
The step of forming the printing layer on the base material layer or the transparent resin layer, and
A step of thermally laminating the transparent resin layer on the base material layer with the printing layer sandwiched at a temperature of 150 ° C. or higher and 170 ° C. or lower.
A method of manufacturing a decorative sheet.

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