JP5347442B2 - Decorative sheet and molded body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a decorative sheet which has a required appearance such as metallic gloss, is easy to mold, is manufactured at low cost, is low in environmental load, excels in electromagnetic wave transmittance, and excels in durability. <P>SOLUTION: The decorative sheet 100 includes a laminate 20 including a resin layer 21 having a first cholesteric regularity and a resin layer 23 having a second cholesteric regularity, wherein the resin layer 21 having the first cholesteric regularity transmits a first circularly polarized light and reflects a second circularly polarized light which is different from the first circularly polarized light, and the second cholesteric resin layer 23 is disposed so as to reflect at least a part of the first circularly polarized light having transmitted through the resin layer 21 having the first cholesteric regularity. Also a molded body including the decorative sheet 100 is provided. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a decorative sheet and, more particularly, to a decorative laminated sheet that can reflect light in a desired reflection band and have an appearance such as metallic luster and a molded body including the decorative sheet.

  In general, in order to efficiently manufacture an article with a decorated appearance, it is known that a decorative sheet that can be easily molded is used as a member on the outer surface of the article, and this is used as a molded body to form the shape of the article member. It has been. For example, in order to give the article an appearance having a metallic luster, a member for an exterior portion of the article is manufactured using a resin sheet containing metal particles.

  However, a resin containing a metal may require the use of a heavy metal in the production process, and has a high environmental load. Moreover, when decorating the articles | goods which have the function communicated by electromagnetic waves, such as a mobile telephone, the sheet | seat containing a metal will attenuate the transmitted radio wave. For this reason, there is a demand for a decorative sheet that has a metallic luster but has a low metal content or no metal.

  A decorative sheet having a metallic luster but not containing a metal is required to exhibit a luster similar to that of a metal due to a structure made of a substance other than a metal. As such a decorative sheet, a sheet in which a large number of resin layers having different refractive indexes with controlled thicknesses are alternately stacked is known (Patent Document 1).

  However, in order to obtain a sheet having a metallic luster according to such a principle, it is necessary to laminate a very large number of layers such as several hundred layers, the structure is complicated, delamination during molding, Due to non-uniform thickness, hue failure, etc., the manufacturing process is complicated and yield is low, and it is easy to cause degradation such as delamination during use and hue change due to changes in layer thickness over time. There is a problem.

JP 2008-200701 A

  It is an object of the present invention to have a desired appearance such as metallic luster, easy molding, low cost production, low environmental load, excellent electromagnetic wave permeability, and excellent durability. It is to provide a decorative sheet.

As a result of studies to solve the above-mentioned problems, the present inventors have found that the problems can be solved by using a laminate in which resin layers having a predetermined cholesteric regularity are combined, and the present invention has been completed.
That is, according to the present invention, the following [1] to [6] are provided.

[1] A decorative sheet including a laminate including a resin layer having a first cholesteric regularity and a resin layer having a second cholesteric regularity,
The resin layer having the first cholesteric regularity is a layer that transmits the first circularly polarized light and reflects the second circularly polarized light that is different from the first circularly polarized light,
The decorative sheet, wherein the second cholesteric resin layer is disposed so as to reflect at least a part of the first circularly polarized light transmitted through the resin layer having the first cholesteric regularity.
[2] The decorative sheet according to [1], wherein the resin layer having the first and second cholesteric regularities has a helical structure whose pitch is changed stepwise or continuously in the thickness direction.
[3] Further includes a half-wave plate provided between the resin layer having the first cholesteric regularity and the resin layer having the second cholesteric regularity,
The decorative sheet according to [1] or [2], wherein the twist direction of the resin layer having the first cholesteric regularity is the same direction as the twist direction of the resin layer having the second cholesteric regularity.
[4] The additive according to [1] or [2], wherein a twist direction of the resin layer having the first cholesteric regularity is opposite to a twist direction of the resin layer having the second cholesteric regularity. Decorative sheet.
[5] The decorative sheet according to any one of [1] to [4], further including a pair of outer resin layers as both outer layers of the laminate.
[6] A molded article including the decorative sheet according to any one of [1] to [5].

The decorative sheet and molded article of the present invention can have a desired appearance such as metallic luster by including a laminate in which resin layers having predetermined cholesteric regularity are combined. In particular, since it can obtain a metallic luster without containing metal, it can be easily molded at low cost while having such a design appearance, has low environmental impact, and has excellent electromagnetic wave permeability. And it can be set as the decorating sheet and molded object excellent in durability.
In particular, the resin layers having the first and second cholesteric regularities have a helical structure in which the pitch is changed stepwise or continuously in the thickness direction, so that the number of the resin layers is smaller than that of the conventional decorative sheet. Good metallic luster can be obtained by the number of layers.
In particular, the moldability can be further improved by further including an outer resin layer on both sides of the laminate.

Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.
The decorative sheet of the present invention includes a resin layer having a first cholesteric regularity (hereinafter, a resin layer having a cholesteric regularity may be simply referred to as “cholesteric resin layer”), and a second cholesteric resin layer. Including a laminate.

(First embodiment)
FIG. 1 is a longitudinal sectional view schematically showing a first embodiment of the decorative sheet of the present invention.
In FIG. 1, the decorative sheet 100 includes a laminate 20 including a first cholesteric resin layer 21, a half-wave plate 22, and a second cholesteric resin layer 23. The decorative sheet 100 has outer resin layers 24 and 25 on both outer sides of the laminate 20, that is, on the upper side of the first cholesteric resin layer 21 and the lower side of the second cholesteric resin layer in the illustration in FIG. I have. The layers 21 to 25 are bonded together via an appropriate pressure-sensitive adhesive (not shown), thereby forming a single decorative sheet 100.

  In the present invention, the first cholesteric resin layer is a layer that transmits the first circularly polarized light and reflects the second circularly polarized light that is polarized light different from the first circularly polarized light. The layer is disposed so as to reflect at least a part of the first circularly polarized light transmitted through the first cholesteric resin layer. This will be described below based on an example of the first embodiment.

  In the decorative sheet 100 shown in FIG. 1, both the first cholesteric resin layer 21 and the second cholesteric resin layer 23 have the same direction of twist, and both are left-handed circularly polarized light (the first in this embodiment). 1 circularly polarized light) is transmitted and right circularly polarized light (second circularly polarized light in the present embodiment) is reflected. When natural light 11 is incident on the upper surface 51 of the decorative sheet 100, the natural light 11 passes through the outer resin layer 24 and then reaches the first cholesteric resin layer 21. In general, natural light can be regarded as the sum of right circular polarization and left circular polarization. Here, the right circular polarization component of the natural light 11 is reflected (11R), while the left circular polarization component is the first cholesteric resin layer. 21 is transmitted (12L). In this way, selective transmission and reflection by the first cholesteric resin layer 21 is achieved.

  The left circularly polarized light 12L transmitted through the first cholesteric resin layer 21 enters the half-wave plate 22 (13L). When the left circularly polarized light 13 </ b> L passes through the half-wave plate 22, it is converted into right circularly polarized light 13 </ b> R and reaches the second cholesteric resin layer 23. Here, the right circularly polarized light 13R is reflected while maintaining the chirality, that is, the right circularly polarized light (14R), passes through the half-wave plate 22 again, and is converted into the left circularly polarized light 14L here. In this way, reflection of the first circularly polarized light in the second cholesteric resin layer is achieved.

  The left circularly polarized light emitted from the half-wave plate 22 passes through the first cholesteric resin layer 21 (15L), passes through the outer resin layer 24, and is emitted as light 16L. In this way, the natural light 11 incident on the decorative sheet 100 is reflected and emitted from both the right circularly polarized light and the left circularly polarized light. As a result, the surface of the decorative sheet 100 has a glossy surface such as a metallic tone. It can be.

  In the first embodiment, the first cholesteric resin layer and the second cholesteric resin layer have the same twist direction by adopting a configuration having a half-wave plate between the first and second cholesteric resin layers. It will be the direction. Thereby, the same cholesteric resin layer can be used in common as the first and second cholesteric resin layers. Specifically, cholesteric resin layers manufactured by the same manufacturing method can be used as the first and second cholesteric resin layers. More specifically, the cholesteric resin layers of the same production lot manufactured at the same time can be used as the first and second cholesteric resin layers, and further, the cholesteric resin layers manufactured as a single cholesteric resin layer are divided into the first and second cholesteric resin layers, respectively. It can also be used as the first and second cholesteric resin layers. Thus, the same cholesteric resin layer can be used as the first and second cholesteric resin layers, so that a resin layer having uniform optical characteristics can be easily provided, thereby providing a decorative sheet having a good gloss. Can be easily manufactured.

  In the present invention, it is preferable that the resin layer having the first and second cholesteric regularities has a helical structure in which the pitch is changed in the thickness direction in order to obtain a good metallic luster with a small number of layers. . The change in pitch in the thickness direction can be stepwise or continuous, and particularly by making it continuous, a better metallic luster can be obtained with a smaller number of layers.

  In the decorative sheet 100, the outer resin layers 24 and 25, which are optional components of the present invention, can be layers having various functions, and particularly preferably, as described in detail later, It can be set as the layer which improves a moldability.

  When both the outer resin layers 24 and 25 are transparent resin layers, the decorative sheet 100 can reflect light on both surfaces thereof, and thus both surfaces can be used as glossy surfaces. In this case, when light is incident from the surface 52 on the layer 25 side of the decorative sheet 100, the cholesteric resin layer 23 functions as the first cholesteric resin layer in the present invention, and the cholesteric resin layer 21 is the present invention. It functions as a second cholesteric resin layer.

  Alternatively, one of the outer resin layers 24 and 25 can be a non-transparent layer. For example, by forming the resin layer 24 as a transparent resin layer and the resin layer 25 as an opaque resin layer, a decorative sheet that does not transmit light and has gloss on the surface on the resin layer 24 side is obtained. Can do. The transparent resin layer is a layer composed of a resin having a total light transmittance of 80% or more at a thickness of 1 mm.

  The appearance of the surface of the decorative sheet of the present invention can be made to have a metallic gloss by reflecting a wide band of visible light (for example, 400 to 700 nm), but is not limited thereto, Various colors such as colored metal appearance by providing a colored layer to be described later or appropriately controlling the reflection band of the cholesteric resin layer (only a part of the visible range is set as the reflection band). , Texture, pattern appearance.

(Second Embodiment)
FIG. 2 is a longitudinal sectional view schematically showing a second embodiment of the decorative sheet of the present invention.
The decorative sheet 200 shown in FIG. 2 has no half-wave plate and the second cholesteric resin layer 43 has a twist direction opposite to that of the first cholesteric resin layer. It is different from the decorative sheet 100 of the first embodiment.

  In the decorative sheet 200, the first cholesteric resin layer 21 transmits left circularly polarized light (first circularly polarized light in the present embodiment) and reflects right circularly polarized light (second circularly polarized light in the present embodiment). On the other hand, the second cholesteric resin layer 23 reflects left circularly polarized light and transmits right circularly polarized light. When natural light 31 is incident on the upper surface 51 of the decorative sheet 200, the right circularly polarized component is reflected (31R), while the left circularly polarized component is transmitted through the first cholesteric resin layer 21, as in the first embodiment. (32L), and selective transmission and reflection by the first cholesteric resin layer 21 is achieved.

  The left circularly polarized light 32 </ b> L that has passed through the first cholesteric resin layer 21 reaches the second cholesteric resin layer 43. Here, the left circularly polarized light 32L is reflected while maintaining the chirality, that is, the left circularly polarized light (33L). In this way, reflection of the first circularly polarized light in the second cholesteric resin layer 43 is achieved.

  The left circularly polarized light emitted from the second cholesteric resin layer 43 passes through the first cholesteric resin layer 21, passes through the resin layer 24, and is emitted as light 34L. In this way, the natural light 31 incident on the decorative sheet 200 is reflected and emitted from both the right circularly polarized light and the left circularly polarized light. As a result, the surface of the decorative sheet 200 has a glossy surface such as a metallic tone. It can be.

  In the second embodiment, since the twist directions of the first and second cholesteric resin layers are opposite to each other, they must be manufactured separately, but it is necessary to provide a half-wave plate between them. Therefore, it is easy to manufacture, and an increase in the amount of reflection can be expected due to the small optical loss due to the half-wave plate.

(Other embodiments)
In the embodiment described above, only one first and second cholesteric resin layer is provided, but the number of cholesteric resin layers is not limited to this, and the first and second cholesteric resin layers are not limited thereto. It is also possible to provide two or more layers. However, in the present invention, in particular, when a cholesteric resin layer having a helical structure in which the pitch is continuously changed in the thickness direction is employed, the number of the first and second cholesteric resin layers is one or two. For example, even when compared with a sheet having several hundred layers as described in, for example, cited document 1, it is possible to obtain a metallic luster that is inferior to that of the sheet.

  The decorative sheet of the present invention can optionally have other layers in addition to the layers described above. Specifically, layers having various functions to be described later can be provided, and the transparent resin substrate and alignment film used for forming the cholesteric resin layer can be incorporated into the decorative sheet of the present invention as they are without peeling. it can.

(Each component)
Next, the preferable example of the essential and arbitrary component in the decorating sheet of this invention is demonstrated more concretely.

(Cholesteric resin layer)
The cholesteric resin layer in the decorative sheet of the present invention will be described.
In the present invention, the cholesteric regularity of the resin layer having cholesteric regularity means that the molecular axes are arranged in a certain direction on one plane, but the direction of the molecular axes forms a slight angle on the next plane that overlaps with it. In this structure, the angle of the molecular axis in the plane is shifted (twisted) as it sequentially passes through the overlapping plane so that the angle is further shifted in the next plane. Thus, the structure in which the direction of the molecular axis is twisted becomes an optically chiral structure.

  The cholesteric resin layer usually has a circularly polarized light separating function. That is, it has a function of transmitting left-rotated or right-rotated circularly polarized light in a specific wavelength region and reflecting other circularly polarized light. The reflection in the cholesteric resin layer reflects circularly polarized light while maintaining its chirality. In this invention, it is preferable to provide the cholesteric resin layer which exhibits this circularly polarized light separation function over the entire wavelength region of visible light. By having such characteristics, it is possible to obtain a metallic luster with a significantly smaller number of layers compared to conventional non-metallic metallic luster decorative sheets such as those described in Patent Document 1. It becomes. As the cholesteric resin layer having such characteristics, a cholesteric resin layer having a helical structure whose pitch is changed stepwise or continuously in the thickness direction, which will be described in detail later, can be used.

  The wavelength that exhibits the circularly polarized light separation function depends on the pitch of the helical structure in the cholesteric resin. The pitch of the helical structure is the distance in the plane normal direction until the angle of the molecular axis in the helical structure gradually shifts as it advances along the plane and then returns to the original molecular axis direction again. By changing the pitch of the helical structure, the wavelength at which the circularly polarized light separating function is exhibited can be changed.

  The cholesteric resin layer can be obtained by providing a coating film of a cholesteric liquid crystal composition on a suitable substrate for forming a resin layer and curing the coating film. And as a cholesteric liquid crystal composition, the composition which contains a liquid crystalline compound and can exhibit a cholesteric liquid crystal phase when it is set as a coating film can be used. Here, a polymerizable liquid crystalline compound can be used as the liquid crystalline compound. By polymerizing such a polymerizable liquid crystalline compound, the coating film is cured, and a non-liquid crystalline resin layer cured while exhibiting the molecular orientation of the liquid crystalline compound can be obtained. Note that the material referred to as a liquid crystal composition here for convenience includes not only a mixture of two or more substances but also a material made of a single substance.

  In the present invention, the intrinsic birefringence value Δn of the cholesteric resin layer is preferably 0.2 or more, more preferably 0.22 or more. By having such a high Δn value, it is possible to reduce a change in hue when observed from an oblique direction while obtaining a high luminance improvement effect. The cholesteric resin layer having such a high Δn value can be formed by using a liquid crystal composition such as a cholesteric liquid crystal composition (X) described later. If a compound having a Δn value of 0.30 or more is used, the absorption edge on the long wavelength side of the ultraviolet absorption spectrum may extend to the visible range. It can be used as long as the performance is not adversely affected.

  As the cholesteric resin layer used in the present invention, for example, (i) a cholesteric resin layer in which the pitch of the helical structure is changed stepwise, and (ii) the pitch of the helical structure is continuously changed. A cholesteric resin layer etc. are mentioned.

  (I) The cholesteric resin layer in which the pitch of the helical structure is changed stepwise includes, for example, a cholesteric resin layer having a helical structure pitch that exhibits a circularly polarized light separation function with light in a blue wavelength range, It can be obtained by laminating a cholesteric resin layer having a helical structure pitch that exhibits a circularly polarized light separating function with light and a cholesteric resin layer having a helical structure pitch that exhibits a circularly polarized light separating function with light in the red wavelength region. it can. Further, cholesteric resin layers having a central wavelength of reflected circularly polarized light of 470 nm, 550 nm, 640 nm, and 770 nm are respectively produced, and these cholesteric resin layers are arbitrarily selected, and the order of the central wavelengths of reflected light is 3 to 3 It can be obtained by laminating seven layers. In the present invention, when the cholesteric resin layers having different spiral pitches are stacked, the rotational directions of the circularly polarized light reflected by the cholesteric resin layers are the same. In addition, in order to obtain a liquid crystal display device having a wide viewing angle, the stacking order of the cholesteric resin layers having different helical structure pitches may be ascending or descending according to the helical structure pitch. preferable. Lamination of these cholesteric resin layers can be performed by fixing them with an adhesive or an adhesive, or by forming another cholesteric resin layer in order after forming a certain cholesteric resin layer. it can.

  (Ii) The cholesteric resin layer in which the pitch of the helical structure is continuously changed is not particularly limited by the manufacturing method, but a preferable example of the manufacturing method of such a cholesteric resin layer is to form a cholesteric resin layer. A cholesteric liquid crystal composition containing a polymerizable liquid crystalline compound for coating is preferably applied on another layer such as an alignment film to obtain a layer of the liquid crystal composition, and then one or more times of light irradiation and / or application. A method of curing the layer in a state where the pitch of the helical structure is continuously changed by the heat treatment is mentioned. Preferable embodiments of the cholesteric liquid crystal composition include cholesteric liquid crystal composition (X) described in detail below.

  The cholesteric resin layer in which the pitch of the helical structure of (ii) is continuously changed may be used as only one layer as the first or second cholesteric resin layer, or a plurality of layers may be overlaid. You may use as a 1st or 2nd cholesteric resin layer. For example, a combination of a cholesteric resin layer that exhibits a circularly polarized light separating function in a part of the visible light wavelength region and a cholesteric resin layer that exhibits a circularly polarized light separating function in another region, It is possible to use a cholesteric resin layer that exhibits a circularly polarized light separating function in a wide area.

The cholesteric liquid crystal composition (X) contains a compound represented by the following general formula (1) and a specific rod-like liquid crystal compound. Each of these components will be described in turn.
R ¹ -A ¹ -BA ² -R ² (1)

In General Formula (1), R ¹ and R ² are each independently a linear or branched alkyl group having 1 to 20 carbon atoms, or a linear or branched chain having 1 to 20 carbon atoms. And a group selected from the group consisting of a hydrogen atom, a halogen atom, a hydroxyl group, a carboxyl group, a (meth) acryl group, an epoxy group, a mercapto group, an isocyanate group, an amino group, and a cyano group. Here, (meth) acryl means acryl and methacryl.

  The alkyl group and alkylene oxide group may be unsubstituted or substituted with one or more halogen atoms. The halogen atom, hydroxyl group, carboxyl group, (meth) acryl group, epoxy group, mercapto group, isocyanate group, amino group, and cyano group are bonded to an alkyl group having 1 to 2 carbon atoms or an alkylene oxide group. May be.

Preferable examples of R ¹ and R ² include a halogen atom, hydroxyl group, carboxyl group, (meth) acryl group, epoxy group, mercapto group, isocyanate group, amino group, and cyano group.

Moreover, it is preferable that at least one of R ¹ and R ² is a reactive group. By having a reactive group as R ¹ and / or R ² , the compound represented by the general formula (1) is fixed in the liquid crystal layer at the time of curing, and a stronger film can be formed. Here, examples of the reactive group include a carboxyl group, a (meth) acryl group, an epoxy group, a mercapto group, an isocyanate group, and an amino group.

In the general formula (1), A ¹ and A ² are each independently 1,4-phenylene group, 1,4-cyclohexylene group, 1,4-cyclohexenyl group, 4,4′-biphenylene group, 4, It represents a group selected from the group consisting of a 4′-bicyclohexylene group and a 2,6-naphthylene group. The 1,4-phenylene group, 1,4-cyclohexylene group, 1,4-cyclohexenyl group, 4,4′-biphenylene group, 4,4′-bicyclohexylene group, and 2,6-naphthylene group are , It may be unsubstituted or substituted with one or more halogen atoms, hydroxyl groups, carboxyl groups, cyano groups, amino groups, alkyl groups having 1 to 10 carbon atoms, or halogenated alkyl groups. In each of A ¹ and A ² , when two or more substituents are present, they may be the same or different.

Particularly preferred examples of A ¹ and A ² include groups selected from the group consisting of 1,4-phenylene group, 4,4′-biphenylene group, and 2,6-naphthylene group. These aromatic ring skeletons are relatively rigid as compared with the alicyclic skeletons, have high affinity with the mesogens of rod-like liquid crystalline compounds described later, and have higher alignment uniformity.

In the general formula (1), B represents a single bond, —O—, —S—, —S—S—, —CO—, —CS—, —OCO—, —CH ₂ —, —OCH ₂ —, —C. = N-N = C -, - NHCO -, - OCOO -, - CH 2 COO-, and is selected from the group consisting of -CH ₂ OCO-.

  Particularly preferable examples of B include a single bond, —OCO—, and —CH═N—N═CH—.

  As for the compound of General formula (1), it is preferable that at least 1 type has liquid crystallinity, and it is preferable to have chirality. The cholesteric liquid crystal composition (X) preferably contains a mixture of a plurality of optical isomers as the compound of the general formula (1). For example, a mixture of plural kinds of enantiomers and / or diastereomers can be contained. At least one of the compounds of the general formula (1) preferably has a melting point in the range of 50 ° C to 150 ° C.

  When the compound of the general formula (1) has liquid crystallinity, a high Δn is preferable. By containing a high Δn liquid crystal, Δn as the cholesteric liquid crystal composition (X) can be improved, and a cholesteric resin layer having a wide selective reflection band can be produced. At least one Δn of the compound of the general formula (1) is preferably 0.18 or more, more preferably 0.22 or more.

  Specific examples of particularly preferred compounds of the general formula (1) include the following compounds (A1) to (A3) and (A5) to (A10):

  In the compound (A3), “*” represents a chiral center.

The cholesteric liquid crystal composition (X) contains a rod-like liquid crystal compound having Δn of 0.18 or more and having at least two or more reactive groups in one molecule.
Examples of the rod-like liquid crystalline compound include compounds represented by the formula (2).
^{R 3 -C 3 -D 3 -C 5} -M-C 6 -D 4 -C 4 -R 4 Formula (2)
(Wherein R ³ and R ⁴ are reactive groups, each independently (meth) acryl group, (thio) epoxy group, oxetane group, thietanyl group, aziridinyl group, pyrrole group, vinyl group, allyl group, D ³ and D ⁴ are groups selected from the group consisting of fumarate group, cinnamoyl group, oxazoline group, mercapto group, iso (thio) cyanate group, amino group, hydroxyl group, carboxyl group, and alkoxysilyl group. A group selected from the group consisting of a bond, a linear or branched alkyl group having 1 to 20 carbon atoms, and a linear or branched alkylene oxide group having 1 to 20 carbon atoms; C ^{3 to} C ⁶ are a single bond, —O—, —S—, —S—S—, —CO—, —CS—, —OCO—, —CH ₂ —, —OCH ₂ —, —CH═. N—N═CH—, —NHC O -, - OCOO -, - CH 2 COO-, and .M represents a group selected from the group consisting of -CH ₂ OCO- represents a mesogenic group, specifically, having a substituted or unsubstituted group Azomethines, azoxys, phenyls, biphenyls, terphenyls, naphthalenes, anthracenes, benzoic acid esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, 2 to 4 skeletons selected from the group of alkoxy-substituted phenylpyrimidines, phenyldioxanes, tolanes, alkenylcyclohexylbenzonitriles, -O-, -S-, -SS-, -CO-, -CS -, - OCO -, - CH 2 -, - OCH 2 -, - CH = N-N = CH -, - NHCO -, - OCOO , -CH ₂ COO-, and is formed are joined by a linking group of -CH ₂ OCO-, and the like.)
Examples of the substituent that the mesogenic group M may have include a halogen atom, an optionally substituted alkyl group having 1 to 10 carbon atoms, a cyano group, a nitro group, —O—R ⁵ , —O—C. (═O) —R ⁵ , —C (═O) —O—R ⁵ , —O—C (═O) —O—R ⁵ , —NR ⁵ —C (═O) —R ⁵ , —C ( = O) -NR < ⁵ > R < ⁷ > or -O-C (= O) -NR < ⁵ > R < ⁷ >. Wherein, R ⁵ and ^{R 7} represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, when it is alkyl group, and the alkyl group, -O -, - S -, - O-C (= O) —, —C (═O) —O—, —O—C (═O) —O—, —NR ⁶ —C (═O) —, —C (═O) —NR ⁶ —, —NR ^6- or -C (= O)-may be present (except when two or more of -O- and -S- are present adjacent to each other). Wherein, R ⁶ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Examples of the substituent in the “optionally substituted alkyl group having 1 to 10 carbon atoms” include a halogen atom, a hydroxyl group, a carboxyl group, a cyano group, an amino group, and an alkoxy group having 1 to 6 carbon atoms. Group, alkoxyalkoxy group having 2 to 8 carbon atoms, alkoxyalkoxyalkoxy group having 3 to 15 carbon atoms, alkoxycarbonyl group having 2 to 7 carbon atoms, alkylcarbonyloxy having 2 to 7 carbon atoms Group, an alkoxycarbonyloxy group having 2 to 7 carbon atoms, and the like.
In the present invention, the rod-like liquid crystalline compound preferably has an asymmetric structure. Here, the asymmetric structure is a structure in which R ³ -C ³ -D ³ -C ⁵ -and -C ⁶ -D ⁴ -C ⁴ -R ⁴ are different in the general formula (2) with the mesogenic group M as the center. Say. By using a rod-like liquid crystal compound having an asymmetric structure, alignment uniformity can be further improved.

  In the present invention, the rod-like liquid crystalline compound has a Δn value of preferably 0.18 or more, more preferably 0.22 or more. When a compound having an Δn value of 0.30 or more is used, the absorption edge on the long wavelength side of the ultraviolet absorption spectrum may extend to the visible range, but desired optical performance even when the absorption edge of the spectrum extends to the visible range. It can be used as long as it does not adversely affect By having such a high Δn value, a cholesteric resin layer having high optical performance (for example, selective reflection performance of circularly polarized light) can be provided.

  In the present invention, the rod-like liquid crystalline compound may have at least two reactive groups in one molecule. Specific examples of the reactive group include an epoxy group, a thioepoxy group, an oxetane group, a thietanyl group, an aziridinyl group, a pyrrole group, a fumarate group, a cinnamoyl group, an isocyanate group, an isothiocyanate group, an amino group, a hydroxyl group, and a carboxyl group. , Alkoxysilyl groups, oxazoline groups, mercapto groups, vinyl groups, allyl groups, methacryl groups, and acrylic groups. By having these reactive groups, a stable cured product can be obtained when the cholesteric liquid crystal composition is cured. When a compound having one or less reactive group in one molecule is used, when the cholesteric liquid crystal composition is cured, a crosslinked cured product cannot be obtained, so that there is a possibility that a film strength that can withstand practical use cannot be obtained. . Even when a cross-linking agent described later is used, the film strength may be insufficient and practical use may be difficult. The film strength that can be practically used is HB or more, preferably H or more, in pencil hardness (JIS K5400). If the film strength is lower than HB, the film is easily scratched and lacks handling properties. The upper limit of preferable pencil hardness is not particularly limited as long as it does not adversely affect the optical performance and durability test.

  Preferable specific examples of the rod-like liquid crystalline compound include the following compounds (B1) to (B9), but the rod-like liquid crystalline compound in the present invention is not limited to the following compounds.

  In the cholesteric liquid crystal composition (X), the weight ratio of (total weight of the compound of the general formula (1)) / (total weight of the rod-like liquid crystal compound) is 0.05 to 1, preferably 0.1 to 0. .65, more preferably 0.15 to 0.45. When the weight ratio is less than 0.05, the alignment uniformity may be insufficient. On the other hand, when the weight ratio is more than 1, the alignment uniformity decreases, the stability of the liquid crystal phase decreases, and the liquid crystal composition As a result, the desired optical performance (for example, the property of selectively reflecting circularly polarized light) may not be obtained. The total weight indicates the weight when one kind is used and the total weight when one or more kinds are used.

  In the cholesteric liquid crystal composition (X), the compound of the general formula (1) preferably has a molecular weight of less than 600, and the rod-like liquid crystal compound has a molecular weight of 600 or more. When the molecular weight of the compound of the general formula (1) is less than 600, the rod-like liquid crystal compound having a molecular weight larger than that can enter the gap, and the alignment uniformity can be improved.

In the present invention, the cholesteric liquid crystal composition such as the cholesteric liquid crystal composition (X) can optionally contain a cross-linking agent in order to improve the film strength and durability after curing. As the cross-linking agent, it reacts simultaneously when the liquid crystal layer coated with the liquid crystal composition is cured, or heat treatment is performed after curing to accelerate the reaction, or the reaction proceeds spontaneously by moisture to increase the cross-linking density of the liquid crystal layer. Those that can be enhanced and that do not deteriorate the alignment uniformity can be appropriately selected and used, and those that are cured by ultraviolet rays, heat, moisture, etc. can be suitably used. Specific examples of the crosslinking agent include, for example, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 2- (2-vinyl Polyfunctional acrylate compounds such as loxyethoxy) ethyl acrylate; epoxy compounds such as glycidyl (meth) acrylate, ethylene glycol diglycidyl ether, glycerin triglycidyl ether, pentaerythritol tetraglycidyl ether; 2,2-bishydroxymethylbutanol-tris [ 3- (1-aziridinyl) propionate], 4,4-bis (ethyleneiminocarbonylamino) diphenylmethane, trimethylolpropane-tri-β-aziridinini Aziridine compounds such as lupropionate; Isocyanurate type isocyanates derived from hexamethylene diisocyanate, hexamethylene diisocyanate, isocyanurate type isocyanates, biuret type isocyanates, adduct type isocyanates; polyoxazoline compounds having an oxazoline group in the side chain; vinyltrimethoxysilane; N- (2-aminoethyl) 3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane, N- (1 , 3-dimethylbutylidene) -3- (triethoxysilyl) -1-propanamine and the like alkoxysilane compounds. Moreover, a well-known catalyst can be used according to the reactivity of this crosslinking agent, and productivity can be improved in addition to an improvement in film strength and durability.
The blending ratio of the crosslinking agent is preferably 0.1 to 15% by weight in a cured film obtained by curing the cholesteric liquid crystal composition. When the blending ratio of the crosslinking agent is less than 0.1% by weight, the effect of improving the crosslinking density cannot be obtained. Conversely, when the blending ratio is more than 15% by weight, the stability of the liquid crystal layer is lowered, which is not preferable.

In the present invention, the cholesteric liquid crystal composition can optionally contain a photoinitiator. As the photoinitiator, known compounds that generate radicals or acids by ultraviolet rays or visible rays can be used. Specifically, benzoin, benzylmethyl ketal, benzophenone, biacetyl, acetophenone, Michler's ketone, benzyl, benzylisobutyl ether, tetramethylthiuram mono (di) sulfide, 2,2-azobisisobutyronitrile, 2,2-azobis -2,4-dimethylvaleronitrile, benzoyl peroxide, di-tert-butyl peroxide, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1- (4 -Isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-diethylthioxanthone, methylbenzoyl formate, 2,2-dieto Cyacetophenone, β-ionone, β-bromostyrene, diazoaminobenzene, α-amylcinnac aldehyde, p-dimethylaminoacetophenone, p-dimethylaminopropiophenone, 2-chlorobenzophenone, pp′-dichlorobenzophenone, pp ′ -Bisdiethylaminobenzophenone, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-propyl ether, benzoin n-butyl ether, diphenyl sulfide, bis (2,6-methoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, 2,4,6-trimethylbenzoyldiphenyl-phosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2-methyl-1 [ 4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, anthracenebenzophenone, α-chloroanthraquinone , Diphenyl disulfide, hexachlorobutadiene, pentachlorobutadiene, octachlorobutene, 1-chloromethylnaphthalene, 1,2-octanedione, 1- [4- (phenylthio) -2- (o-benzoyloxime)] and 1- Carbazole oxime compounds such as [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] ethanone 1- (o-acetyloxime), (4-methylphenyl) [4- (2-methyl Propyl) phenyl] iodonium hexafluorophosphate, 3-methyl- - butynyl tetramethyl hexafluoroantimonate, diphenyl - (p-phenylthiophenyl) sulfonium hexafluoroantimonate, and the like. In addition, two or more compounds can be mixed depending on the desired physical properties, and if necessary, a known photosensitizer or a tertiary amine compound as a polymerization accelerator is added to control curability. You can also.
The blending ratio of the photoinitiator is preferably 0.03 to 7% by weight in the cholesteric liquid crystal composition. When the blending amount of the photoinitiator is less than 0.03% by weight, the degree of polymerization is lowered and the film strength may be lowered. On the other hand, if it is more than 7% by weight, the alignment of the liquid crystal is inhibited and the liquid crystal phase may become unstable.

  In the present invention, the cholesteric liquid crystal composition can optionally contain a surfactant. As the surfactant, those not inhibiting the orientation can be appropriately selected and used. As the surfactant, specifically, a nonionic surfactant containing siloxane or fluorinated alkyl group in the hydrophobic group portion can be preferably used, and an oligomer having two or more hydrophobic group portions in one molecule. Is particularly preferred. These surfactants are PF-151N, PF-636, PF-6320, PF-656, PF-6520, PF-3320, PF-651, PF-652 from PolyFox, OMNOVA, FTX- from Neos 209F, FTX-208G, FTX-204D, Seimi Chemical's Surflon KH-40, and the like can be used. The blending ratio of the surfactant is preferably 0.05% by weight to 3% by weight in the cured film obtained by curing the cholesteric liquid crystal composition. When the blending ratio of the surfactant is less than 0.05% by weight, the orientation regulating force at the air interface is lowered and an orientation defect may occur, which is not preferable. On the other hand, when the amount is more than 3% by weight, it is not preferable because an excessive surfactant may enter between liquid crystal molecules and lower the alignment uniformity.

  In the present invention, the cholesteric liquid crystal composition can optionally contain a chiral agent. Specific examples of the chiral agent include JP-A-2005-289881, JP-A-2004-115414, JP-A-2003-66214, JP-A-2003-313187, JP-A-2003-342219, JP-A-2000-290315, JP-A-6-072962, U.S. Pat. No. 6,468,444, WO98 / 00428, JP-A-2007-176870, etc. can be used as appropriate. For example, it can be obtained as LC756 of BASF Corporation Paliocolor.

  The chiral agent can be added within a range that does not deteriorate the desired optical performance. The content ratio of the chiral agent is usually 1 to 60% by weight in the cholesteric liquid crystal composition.

  In the present invention, the cholesteric liquid crystal composition can further contain other optional components as necessary. Examples of the other optional components include a solvent, a polymerization inhibitor for improving pot life, an antioxidant for improving durability, an ultraviolet absorber, and a light stabilizer. These optional components can be added as long as the desired optical performance is not deteriorated.

  The production method of the cholesteric liquid crystal composition used in the present invention is not particularly limited, and can be produced by mixing the above-described components.

  On the surface of the substrate made of a film such as a transparent resin, an alignment film is provided as necessary, and further subjected to a treatment such as a corona discharge treatment rubbing treatment, and a coating film of the cholesteric liquid crystal composition on this surface. A cholesteric resin layer can be obtained by further providing an alignment treatment and / or a curing treatment as necessary. The application can be carried out by a known method such as an extrusion coating method, a direct gravure coating method, a reverse gravure coating method, a die coating method, or a bar coating method.

  The alignment treatment can be performed, for example, by heating the coating film at 50 to 150 ° C. for 0.5 to 10 minutes. By performing the alignment treatment, the cholesteric liquid crystal composition in the coating film can be aligned well.

  The curing process can be performed by a combination of one or more light irradiations and a heating process. Specifically, the heating conditions are, for example, a temperature of 40 to 200 ° C., preferably 50 to 200 ° C., more preferably 50 to 140 ° C., and a time of 1 second to 3 minutes, preferably 5 to 120 seconds. it can. The light used for light irradiation in the present invention includes not only visible light but also ultraviolet rays and other electromagnetic waves. Specifically, the light irradiation can be performed by, for example, irradiating light having a wavelength of 200 to 500 nm for 0.01 second to 3 minutes.

Here, a circle having a wide reflection band, in which the pitch of the helical structure is continuously changed greatly by repeating weak UV irradiation of 0.01 to 50 mJ / cm ² and heating a plurality of times alternately. A polarization separation element can be obtained. After expanding the reflection band by the above-mentioned weak ultraviolet irradiation, etc., a relatively strong ultraviolet ray of 50 to 10,000 mJ / cm ² is irradiated to completely polymerize the liquid crystalline compound to form a cholesteric resin layer. it can. The expansion of the reflection band and the irradiation with strong ultraviolet rays may be performed in the air, or a part or all of the process may be performed in an atmosphere in which the oxygen concentration is controlled (for example, in a nitrogen atmosphere). .

  In the present invention, the step of applying and curing the cholesteric liquid crystal composition on another layer such as an alignment film is not limited to one time, and the coating and curing are repeated a plurality of times to form two or more cholesteric resin layers. You can also. However, by using a liquid crystal composition such as the cholesteric liquid crystal composition (X), a well-oriented rod-like liquid crystal compound having a Δn of 0.18 or more even when the cholesteric liquid crystal composition is applied and cured only once. And a cholesteric resin layer having a thickness of 5 μm or more can be easily formed.

  In the present invention, the dry film thickness of the cholesteric resin layer is preferably 10 μm or less, more preferably 2 to 7 μm, and even more preferably 3 to 6 μm. By changing the film thickness to 10 μm or less, a change in hue when observed from an oblique direction can be reduced. On the other hand, by setting the film thickness to 2 μm or more, sufficient reflectance can be obtained. The dry film thickness refers to the total film thickness of each layer when the cholesteric resin layer is two or more layers, and the film thickness when the cholesteric resin layer is one layer.

  The obtained cholesteric resin layer may be used as it is for the decorative sheet of the present invention as it is together with the base material and the alignment film. If necessary, the base material is peeled off and only the cholesteric resin layer is transferred to decorate the present invention. You may use for a sheet. When using a cholesteric resin layer with a base material for a decorating sheet, arrange | position a cholesteric resin layer in a decorating sheet so that this base material may become a resin layer (resin layers 24 and 25 in FIG.1 and FIG.2). You can also

  The transparent resin substrate that can be used for forming the cholesteric resin layer is not particularly limited, and a substrate having a thickness of 1 mm and a total light transmittance of 80% or more can be used. Specifically, alicyclic olefin polymers, chain olefin polymers such as polyethylene and polypropylene, triacetyl cellulose, polyvinyl alcohol, polyimide, polyarylate, polyester, polycarbonate, polysulfone, polyethersulfone, modified acrylic polymer, epoxy resin, Examples thereof include a single layer or laminated film made of a synthetic resin such as polystyrene or acrylic resin. Among these, an alicyclic olefin polymer or a chain olefin polymer is preferable, and an alicyclic olefin polymer is particularly preferable from the viewpoint of transparency, low hygroscopicity, dimensional stability, lightness, and the like.

The alignment film that can be used to form the cholesteric resin layer is subjected to a corona discharge treatment on the surface of the substrate, if necessary, and then a reverse gravure coating solution prepared by dissolving the alignment film material in water or a solvent. It can be formed by applying and drying using a known method such as direct gravure coating, die coating or bar coating, and then subjecting the dried coating film to rubbing treatment. As the material for the alignment film, cellulose, silane coupling agent, polyimide, polyamide, polyvinyl alcohol, epoxy acrylate, silanol oligomer, polyacrylonitrile, phenol resin, polyoxazole, cyclized polyisoprene, etc. can be used. Polyamide is particularly preferred.
Examples of the modified polyamide include those obtained by modifying an aromatic polyamide or an aliphatic polyamide, and those obtained by modifying an aliphatic polyamide are preferred. Specifically, for example, modified to nylon-6, nylon-66, nylon-12, ternary to quaternary copolymer nylon, fatty acid polyamide, or fatty acid block copolymer (for example, polyether ester amide, polyester amide). Can be mentioned. Examples of the modification include terminal amino modification, carboxyl modification, hydroxyl modification and the like, and modification in which a part of the amide group is alkylaminated or N-alkoxyalkylated. Examples of the N-alkoxyalkylated modified polyamide include N-methoxymethylated part of the amide group of a copolymer nylon such as nylon-6, nylon-66, or nylon-12. The weight average molecular weight of the modified polyamide is preferably 5,000 to 500,000, more preferably 10,000 to 200,000.
The thickness of the alignment film may be any film thickness that provides the desired alignment uniformity of the liquid crystal layer, and is preferably 0.001 to 5 μm, and more preferably 0.01 to 2 μm.

  The twist direction of the cholesteric resin layer can be appropriately selected depending on the type (structure) of the chiral agent to be used. When the twist is set to the right direction, a chiral agent that imparts dextrorotation is used, and when the twist direction is set to the left direction, it can be realized by using a chiral agent that imparts levorotation.

(1/2 wavelength plate)
The half-wave plate that the decorative sheet of the present invention can optionally have is a layer that can reverse the twist direction of the transmitted circularly polarized light. In other words, the half-wave plate can convert the right circularly polarized light passing therethrough into left circularly polarized light and the left circularly polarized light into right circularly polarized light.

  A half-wave plate having a high total light transmittance is preferable for increasing the light reflection amount of the decorative sheet. Moreover, it is preferable that the decorative sheet is thin and lightweight and easy to mold, and is easy to mold and enhances easy moldability. Furthermore, it is preferable that the half-wave plate has a wide band, that is, a wide wavelength range in which the twist direction of circularly polarized light can be converted. As a half-wave plate having these preferable characteristics, a resin sheet having optical anisotropy such as a stretched film is preferably used.

  The half-wave plate used in the present invention is a ratio Re (450) / Re (in-plane retardation value Re (550) measured at a wavelength of 550 nm and in-plane retardation value Re (450) measured at a wavelength of 450 nm. 550) is preferably 1.007 or less, and more preferably 1.006 or less. The lower limit of the ratio Re (450) / Re (550) is preferably 0.5, more preferably 0.7. By providing a half-wave plate with Re (450) / Re (550) falling within the above range, a metallic tone with good color can be obtained.

  Retardation includes retardation in the film plane (Re) and retardation in the film thickness direction (Rth). Retardation (Re) in the film plane can be obtained by Re = (nx−ny) × d, where the main refractive index in the film plane is nx and ny, and the film thickness is d (nm). . Retardation (Rth) in the film thickness direction is expressed as follows: Rth = {n, where the main refractive index in the film plane is nx, ny, the refractive index in the film thickness direction is nz, and the thickness of the film is d (nm). (Nx + ny) / 2−nz} × d. Re and Rth can be measured using a commercially available automatic birefringence meter (“KOBRA-21ADH” manufactured by Oji Scientific Instruments).

  The half-wave plate preferably has an in-plane retardation Re (550) measured at a wavelength of 550 nm of 250 to 300 nm. The half-wave plate has a ratio Re (λ) / λ of the retardation Re (λ) and the wavelength λ at a certain wavelength λ is usually 0.45 to 0.55 over the entire visible wavelength range. Preferably it is 0.46-0.54, More preferably, it is the range of 0.28-0.52.

  The half-wave plate may have a single-layer structure or a laminated structure as long as it has the above characteristics.

  The optically anisotropic element constituting the half-wave plate can be obtained by stretching and orienting the transparent resin film. The slow axis of the optical anisotropic body usually occurs in the stretching direction or a direction perpendicular thereto. Note that the slow axis is the direction in which the phase delay becomes maximum when linearly polarized light is incident.

  The transparent resin film used for the half-wave plate is preferably composed of a resin having a total light transmittance of 80% or more at a thickness of 1 mm. Examples of such resins include polymer resins having an alicyclic structure, chain olefin polymers such as polyethylene and polypropylene, polycarbonate polymers, polyester polymers, polysulfone polymers, and polyethersulfone polymers. Polymers and resins having positive intrinsic birefringence such as polyvinyl alcohol polymers; negative polymers such as vinyl aromatic polymers, polyacrylonitrile polymers, polymethyl methacrylate polymers, cellulose ester polymers, etc. A resin having intrinsic birefringence can be mentioned. These can be used alone or in combination of two or more.

  Among the resins having positive intrinsic birefringence, polymer resins and chain olefin polymers having an alicyclic structure are preferable, and particularly excellent in transparency, low hygroscopicity, dimensional stability, light weight, and the like. A polymer resin having a cyclic structure is preferred. Examples of the polymer resin having an alicyclic structure include a norbornene polymer, a monocyclic olefin polymer, and a vinyl alicyclic hydrocarbon polymer. Among these, norbornene-based polymers can be suitably used because they have good transparency and moldability. Examples of the norbornene-based polymer include a ring-opening polymer of a norbornene-based monomer, a ring-opening copolymer of a norbornene-based monomer and another monomer, and a hydrogenated product of these polymers; Examples include addition polymers of monomers, addition copolymers of norbornene monomers and other monomers, and hydrogenated products of these polymers. Among these, a hydrogenated product of a ring-opening polymer or a ring-opening copolymer of a norbornene monomer is particularly preferable because it is excellent in transparency.

  Among the resins having negative intrinsic birefringence, at least one selected from vinyl aromatic polymers, polyacrylonitrile polymers, and polymethyl methacrylate polymers is preferable. Of these, vinyl aromatic polymers are more preferable from the viewpoint of high birefringence. The vinyl aromatic polymer refers to a polymer of a vinyl aromatic monomer or a copolymer of a monomer copolymerizable with a vinyl aromatic monomer. Examples of the vinyl aromatic monomer include styrene; styrene derivatives such as 4-methylstyrene, 4-chlorostyrene, 3-methylstyrene, 4-methoxystyrene, 4-tert-butoxystyrene, and α-methylstyrene; It is done. These may be used alone or in combination of two or more. Monomers copolymerizable with vinyl aromatic monomers include olefins such as propylene and butene; α, β-ethylenically unsaturated nitrile monomers such as acrylonitrile; acrylic acid, methacrylic acid, maleic anhydride, etc. Α, β-ethylenically unsaturated carboxylic acid; acrylic ester, methacrylic ester; maleimide; vinyl acetate; vinyl chloride; Among vinyl aromatic polymers, a copolymer of styrene or a styrene derivative and maleic anhydride is preferable because of high heat resistance.

  As said transparent resin, that whose glass transition temperature Tg is 90 degreeC or more is preferable from the point which is excellent in the heat resistance of a film, and what is 100 degreeC or more is especially preferable. Moreover, as said transparent resin, it is preferable that it is 100-200 degreeC, and it is more preferable that it is 120-140 degreeC. The method for forming the transparent resin film is not particularly limited, and can be formed by a method such as a solution casting method or a melt extrusion method. Among these, the melt extrusion method that does not use a solvent can reduce the content of volatile components of the film, is easy to produce a film having a large Rth of 100 μm or more, and is preferable from the viewpoint of manufacturing cost. Examples of the melt extrusion method include a method using a T die and an inflation method, and a method using a T die is preferable in terms of excellent productivity and thickness accuracy.

  The retardation of the half-wave plate can be controlled, for example, by appropriately setting the stretching conditions such as the film material, the thickness of the film before stretching, the stretching ratio and the stretching temperature. When the glass transition temperature of the transparent resin is Tg, the film is preferably stretched at a temperature range of Tg-30 ° C to Tg + 60 ° C, more preferably at a temperature range of Tg-10 ° C to Tg + 50 ° C, preferably 1 Performed at a draw ratio of 01 to 2 times. The stretching speed is preferably 5 to 1000 mm / second, more preferably 10 to 750 mm / second. When the stretching speed is within the above range, stretching control is facilitated, and an optical anisotropic body with small variations in surface accuracy and retardation can be obtained.

  The refractive index nz in the thickness direction of the half-wave plate used in the present invention is not particularly limited. For example, nz and other main refractive indexes nx and ny have a relationship of nx> ny> nz, nx> ny = nz, nx> nz> ny, nx = nz> ny, nz> nx> ny. Can be mentioned. The half-wave plate has a thickness of preferably 10 to 500 μm, more preferably 20 to 250 μm, and particularly preferably 20 to 120 μm.

  More specific examples of broadband half-wave plates obtained by laminating multiple layers of resin sheets having optical anisotropy include the same material, the same phase difference, and the slow axis at different angles. A half-wave plate (see Japanese Patent Application Laid-Open No. 2004-258508) and a half-wave plate (see Japanese Patent Application Laid-Open No. 2003-090912) formed by bonding materials having different intrinsic refractive indexes. Can be mentioned. The former half-wave plate can be efficiently manufactured, for example, by laminating a plurality of types of obliquely stretched sheets having different stretching directions with respect to the extending direction, while the latter half-wave plate is, For example, a stretched film formed by stretching a film made of a resin having a positive intrinsic birefringence value such as a norbornene resin, and a stretched film formed by stretching a film made of a resin having a negative intrinsic birefringence value such as a styrene maleic anhydride resin. A film obtained by laminating these films so that their orientation directions are parallel is preferable because it can be efficiently produced and is a broadband half-wave plate.

As another example of the film having optical anisotropy constituting the half-wave plate, a film obtained by aligning and fixing a liquid crystalline compound can be mentioned.
The liquid crystalline compound has optical anisotropy, and a film having optical anisotropy can be obtained by arranging and fixing the liquid crystalline compound in a certain direction. Specifically, a low molecular weight or high molecular weight liquid crystalline compound having a property of being polymerized or crosslinked by ultraviolet rays or heat in the presence of a polymerization initiator or a crosslinking agent, or a mixture thereof was aligned substantially uniformly. It can be obtained by immobilization by polymerization or crosslinking reaction.

  Examples of the liquid crystal compound used for obtaining the half-wave plate include a rod-like liquid crystal compound, a discotic liquid crystal compound, or a mixture thereof. As rod-like liquid crystalline compounds, azomethines, azoquinones, cyanobiphenyls, cyanophenyl esters, benzoic acid esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, tolans, cyano-substituted phenylpyrimidines, alkoxy-substituted compounds Examples thereof include phenylpyrimidines, phenyldioxanes, and alkenylcyclohexylbenzonitriles. Moreover, not only the low molecular liquid crystalline compound as described above but also a polymer rod-shaped liquid crystalline compound can be used. Furthermore, specific examples of the rod-like liquid crystalline compound include polymerizable liquid compositions described in JP-A-7-294735, JP-A-2002-174724, and JP-A-8-283748. As an example of an optical anisotropic body using a rod-like liquid crystal compound, a film in which liquid crystal is vertically aligned shows a relationship of nz> nx = ny (including the case where nx and ny are approximated) An example of a tilted film showing a relationship of nz> nx> ny.

  As the discotic liquid crystalline compound, various documents (for example, C. Desradade et al., Mol. Crysr. Liq. Cryst., Vol. 71, page 111 (1981); edited by the Chemical Society of Japan, Quarterly Chemical Review, No. .22, Liquid Crystal Chemistry, Chapter 5, Chapter 10, Section 2 (1994); B. Kohne et al., Angew. Chem. Soc. Chem. Comm. Page 1794 (1985); and J. Zhang et al. , J. Am. Chem. Soc., Vol. 116, page 2655 (1994); The polymerization of discotic liquid crystalline compounds is described in JP-A-8-27284. In order to fix the discotic liquid crystalline compound by polymerization, a polymerizable group can be bonded to the discotic core of the discotic liquid crystalline compound via a linking group. Examples of such discotic liquid crystalline compounds include those described in JP-A No. 2000-284126.

  The alignment of the liquid crystal compound can usually be performed by applying the liquid crystal compound on an alignment film formed on the substrate. The material of the alignment film can usually be a polymer compound having optical isotropy. Specifically, as the materials for the base material and the alignment film, the same materials as those described above for use in forming the cholesteric resin layer can be used.

  The thickness of the optically anisotropic layer composed of the alignment-fixed film of the liquid crystalline compound is not particularly limited, but provides a sufficient function as a half-wave plate that gives a half-wave retardation to incident light. Above, it is preferable that it is 0.5-50 micrometers normally. By setting the kind of the liquid crystal compound immobilization film and the thickness of the liquid crystal compound immobilization film layer to predetermined values, a half-wave plate composed of the liquid crystal compound immobilization film layer can be obtained. it can.

(Adhesive layer)
In the present invention, the first and second cholesteric resin layers, the half-wave plate, and other optional layers can be integrated via an adhesive layer.

  The pressure-sensitive adhesive layer can be a layer formed by laminating a pressure-sensitive adhesive composition containing a polymer that expresses pressure-sensitive adhesive (hereinafter sometimes simply referred to as “main polymer”) and curing it as necessary.

  Examples of the main polymer include acrylic, urethane, polyester, polyamide, polyvinyl ether, polyvinyl alcohol, polyvinyl acetal, polyvinyl formal, hydroxyethyl cellulose, hydroxypropyl cellulose, ethylene-vinyl acetate, ethylene-acrylic ester, ethylene -Synthetic rubber type, such as vinyl chloride type, styrene-butadiene-styrene, epoxy type, and silicone type polymer can be used. In particular, acrylic, urethane, and ethylene-vinyl acetate are preferably used.

  Acrylic polymers include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, hexyl (meth) acrylate, (meth ) (Meth) acrylic acid alkyl esters such as octyl acrylate, nonyl (meth) acrylate, decyl (meth) acrylate; unsaturated such as (meth) acrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid Carboxylic acid; Hydroxyl group-containing vinyl monomer such as (meth) acrylic acid-2-hydroxyethyl, monoester of (meth) acrylic acid and polyethylene glycidicol or polypropylene glycol; Epoxy such as glycidyl (meth) acrylate Group-containing vinyl monomer; methoxyethyl (meth) acrylate, ( T) Ethoxyethyl acrylate, propoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, ethoxypropyl (meth) acrylate, alkoxyalkyl (meth) acrylate; (meth) acrylamide, methylol (meth) acrylamide Amide group-containing vinyl monomers such as methoxyethyl (meth) acrylamide; silicon-containing vinyl monomers such as methacryloxypropylmethoxysilane; aziridine group-containing vinyl monomers such as (meth) acryloylaziridine; (meth) acrylic Aromatic group-containing vinyl monomers such as phenyl acid, benzyl (meth) acrylate, styrene, methylstyrene; alicyclic alcohols such as cyclohexyl (meth) acrylate and isobornyl (meth) acrylate and (meth) acrylic acid Esters with 2 (meth) acryloyl groups such as ethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc. Monomers having at least one monomer; and other single polymers or copolymers of plural monomers such as vinyl acetate, vinyl chloride, macromonomer, and divinylbenzene. In addition, (meth) acrylic acid means both acrylic acid and methacrylic acid, and (meth) acrylate means both acrylate and methacrylate.

  Examples of the urethane polymer include a reaction product of a general polyol and an isocyanate compound.

  As the polyol, a polyether polyol having a repeating structure of an alkylene oxide chain such as a methylene oxide chain, an ethylene oxide chain, an ethylene oxide chain, a propylene oxide chain, and a butylene oxide chain, or two or more kinds; terephthalic acid, adipic acid, Acid compounds such as adipic acid, sebacic acid, phthalic anhydride, isophthalic acid, trimet acid and ethylene glycol, propylene glycol, diethylene glycol, butylene glycol, 1,6-hexane glycol, 3-methyl-1,5-pentanediol, 3 , 3'-dimethylol heptane, polyoxyethylene glycol, polyoxypropylene glycol, 1,4-butanediol, neopentyl glycol, butylethylpentanediol Polyester polyol obtained by esterification reaction with the above component; Polyester polyol obtained by reaction of the above acid compound with polyol such as glycerin, trimethylolpropane, pentaerythritol; polycaprolactone, poly (β-methyl-γ-valerolactone) And polyester polyols obtained by ring-opening polymerization of lactones such as polyvalerolactone.

  Examples of the isocyanate compound include 1,3-phenylene diisocyanate, 4,4′-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 4,4′-diphenylenemethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate. Aromatic polyisocyanates such as diisocyanate, 4,4′-toluidine diisocyanate, 4,4′-diphenyl ether diisocyanate; trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 2,3-butylene diisocyanate, 1, Aliphatic polymers such as 3-butylene diisocyanate, dodecane methylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate Cyanate; ω, ω′-diisocyanate-1,3-dimethylbenzene, ω, ω′-diisocyanate-1,4-dimethylbenzene, ω, ω′-diisocyanate-1,3-diethylbenzene, 1,4-tetramethylxylyl Aromatic aliphatic polyisocyanates such as diisocyanate and 1,3-tetramethylxylylene diisocyanate; 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate methyl -2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4'-methylenebis (cyclohexyl isocyanate), 1,4'-bis (isocyanatomethyl) cyclohexane. Such as aromatic polyisocyanates and the like.

  Examples of the ethylene-vinyl acetate copolymer include an ethylene-vinyl acetate copolymer and an ethylene-vinyl acetate-carboxylic acid copolymer, preferably those having a vinyl acetate copolymerization rate of 10 to 46% by weight. Can be mentioned.

  The molecular weight range of the main polymer is preferably 10,000 to 1,000,000, and more preferably 50,000 to 500,000 in terms of weight average molecular weight. If the weight average molecular weight is lower than 10,000, it is not preferable because whitening of the adhesive layer is likely to occur. Further, if the weight average molecular weight is larger than 1,000,000, it is not preferable because gelation easily occurs and the viscosity of the adhesive layer solution is high and difficult to handle.

The pressure-sensitive adhesive composition may further contain an acetophenone-containing compound in addition to the main polymer. These compounds may contain 0.5 to 10 parts by weight with respect to 100 parts by weight of the main polymer. preferable. The acetophenone-containing compound is a compound in which one or more hydrogen atoms of acetophenone and acetophenone are substituted with an arbitrary group. Specifically, for example, the —CH ₃ group of acetophenone is substituted with an alicyclic compound or a derivative thereof. Compound (1-hydroxycyclohexyl-phenyl ketone, etc.) and a benzoin ether-containing compound (an ether having a structure in which the hydrogen atom of the —OH group of benzoin is substituted with another organic group, and 1 of the hydrogen atoms of the ether) Examples thereof include compounds in which the above is substituted with an arbitrary group.

  Specific examples of the acetophenone-containing compound include acetophenone, methoxyacetophenone, 2,2-diethoxyacetophenone, p-dimethylaminoacetophenone, p-dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone (IRG651 Ciba Specialty) Chemicals Co., Ltd.), α-hydroxy-α, α′-dimethylacetophenone (DAROCURE 1173 manufactured by Ciba Specialty Chemicals Co., Ltd.), 2-hydroxy-2-cyclohexylacetophenone (IRG184 manufactured by Ciba Specialty Chemicals Co., Ltd.), 2- Methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one (IRG907 manufactured by Ciba Specialty Chemicals), 1- [4- (2-hydroxy Toxi) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one (IRG2959, manufactured by Ciba Specialty Chemicals), 2-benzyl-2-dimethylamino-1- (4-morpholino) Phenyl) -butanone-1-one (IRG369 manufactured by Ciba Specialty Chemicals Co., Ltd.). Examples of the benzoin ether-containing compound include benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl butyl ether. By containing these acetophenone-containing compounds, the performance as an adhesive layer can be improved.

  According to the kind of main polymer, another compounding agent can be further mix | blended with the said adhesive composition. Examples of other compounding agents include tackifiers, crosslinking agents or curing agents, antioxidants, antifoaming agents, and stabilizers.

  The tackifier imparts adhesive force to the main polymer that is soft and has a solid surface that is easily wetted. Such tackifiers include rosin and rosin derivatives, polyterpene resins, terpene phenol resins, coumarone-indene resins, petroleum resins, hydrogenated petroleum resins and the like. Among these, petroleum resins, hydrogenated petroleum resins, and terpene phenol resins are preferable because they are excellent in transparency and compatibility with the main polymer. The compounding amount of the tackifier is preferably 2 to 50 parts by weight, more preferably 5 to 20 parts by weight with respect to 100 parts by weight of the main polymer. If the addition amount of the tackifier is less than 2 parts by weight, the effect of the tackifier may not be manifested. Conversely, if the addition amount exceeds 50 parts by weight, the adhesive force decreases due to a decrease in the cohesive force of the adhesive. Is not preferable because of the tendency to be seen.

  Examples of the crosslinking agent or curing agent include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and 2- (2-vinyloxy). Polyfunctional acrylate compounds such as ethoxy) ethyl acrylate; polyfunctional isocyanate crosslinking agents such as tolylene diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, trimethylolpropane tolylene diisocyanate, diphenylmethane triisocyanate; ethylene glycol glycidyl ether, polyethylene Glycol diglycidyl ether, diglycidyl ether, trimethylolpropane triglycidyl ether, Any epoxy crosslinking agent or curing agent; vinyltrimethoxysilane, methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-aminopropyl Silane-based crosslinking agents or curing agents such as trimethoxysilane and N- (2-aminoethyl) 3-aminopropyltrimethoxysilane; melamine resin-based crosslinking agents; metal chelate-based crosslinking agents; amine-based crosslinking agents are used. The blending amount of the crosslinking agent or curing agent is preferably 0.001 to 10 parts by weight, more preferably 0.01 to 3 parts by weight with respect to 100 parts by weight of the main polymer. When the addition amount of the crosslinking agent or curing agent is less than 0.001 part by weight, the effect of the crosslinking agent is not exhibited, and foaming or peeling may be noticeable in a weather resistance test or the like. On the contrary, when the addition amount of the crosslinking agent or the curing agent is more than 10 parts by weight, the stress relaxation property of the pressure-sensitive adhesive is lowered, and there is a possibility that warpage or the like is noticeable.

  Examples of the antioxidant include phenol-based antioxidants such as tetrakis (methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate) methane, phosphorus-based antioxidants, and thioether-based antioxidants. Agents. The blending amount of the antioxidant is within a range in which the transparency and adhesive strength of the adhesive layer are not lowered.

  The adhesive composition preferably has a shear storage modulus at a temperature of 23 ° C. of 0.1 to 10 MPa. By setting it as the shear storage elastic modulus of this range, an adhesive composition can have moderate adhesiveness. However, not only this but what is called a hot-melt-type adhesive agent which has a higher shear storage elastic modulus can also be used as an adhesive composition in this invention.

  The method for preparing the pressure-sensitive adhesive composition is not limited as long as a uniform mixing and dispersion state can be obtained. For example, the above-mentioned components can be mixed by heating, stirring, ultrasonic treatment, or the like.

  In this invention, it is preferable that the film thickness of an adhesion layer is 5-30 micrometers, and it is more preferable that it is 10-25 micrometers. Adhesive strength can be secured by setting the film thickness to 5 μm or more, while optical performance such as transmittance can be maintained by setting the film thickness to 30 μm or less.

(Outside resin layer)
In this invention, an outer side resin layer is a layer provided in the outer side of the laminated body containing the 1st and 2nd cholesteric resin layer. The position where the outer resin layer is provided is not limited to the outermost layer of the decorative sheet, and may be provided on the inner side of other layers described later.
The material of the outer resin layer may be either a thermoplastic resin or a thermosetting resin, may be a homo resin, may be a copolymer or a blend of two or more types, but has good moldability Therefore, the thermoplastic resin is particularly preferable. In each resin, various additives such as antioxidants, antistatic agents, crystal nucleating agents, inorganic particles, organic particles, viscosity reducers, thermal stabilizers, lubricants, infrared absorbers, ultraviolet absorbers, Doped particles for adjusting the refractive index may be added.

  Examples of thermoplastic resins include polyolefin resins such as polyethylene, polypropylene, polystyrene, and polymethylpentene, alicyclic polyolefin resins, polyamide resins such as nylon 6 and nylon 66, aramid resins, polyethylene terephthalate, polybutylene terephthalate, and polypropylene terephthalate.・ Polybutyl succinate ・ Polyester resin such as polyethylene-2,6-naphthalate, polycarbonate resin, polyarylate resin, polyacetal resin, polyphenylene sulfide resin, tetrafluoroethylene resin, trifluoroethylene resin, trifluorochloroethylene resin・ Fluorine resin such as ethylene tetrafluoride-6-propylene copolymer / vinylidene fluoride resin, acrylic resin, methacrylic resin, polyacetal resin, It can be used polyglycolic acid resin, polylactic acid resin, and a resin having an alicyclic structure. Among these, from the viewpoint of strength, heat resistance, and transparency, a polyester resin or a resin having an alicyclic structure is more preferable. The polyester resin referred to in the present invention refers to a homopolyester or a copolyester that is a polycondensate of a dicarboxylic acid component skeleton and a diol component skeleton. Here, typical examples of the homopolyester include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, poly-1,4-cyclohexanedimethylene terephthalate, and polyethylene diphenylate. In particular, polyethylene terephthalate is preferable because it is inexpensive and can be used in a wide variety of applications. The resin having an alicyclic structure is an amorphous olefin polymer having a cycloalkane structure in the main chain and / or side chain. Specifically, (1) norbornene polymer, (2) monocyclic olefin polymer, (3) cyclic conjugated diene polymer, (4) vinyl alicyclic hydrocarbon polymer, and hydrides thereof. Is mentioned. Among these, a norbornene polymer is more preferable from the viewpoint of transparency and moldability. Examples of the resin having these alicyclic structures include those described in JP-A-5-310845, JP-A-5-97978, and US Pat. No. 6,511,756.

  The thickness of the outer resin layer is preferably 50 to 300 μm, and more preferably 100 to 250 μm. By setting it as the range of this thickness, favorable moldability can be imparted to the decorative sheet.

(Colored layer)
The decorative sheet of the present invention can be provided with a colored layer as necessary. By providing such a colored layer, the color of the decorative sheet can be adjusted. The cholesteric resin layer can be freely designed for its selective reflection band, but by combining the resulting color with the coloring by the colored layer, it can have a metallic luster or other specific color luster. Can be obtained as desired. Although the position which provides a colored layer in the decorating sheet of this invention is not specifically limited, It is preferable to provide in the outer side rather than the 1st and 2nd cholesteric resin layer.

(Other layers)
In addition to each layer described above, the decorative sheet of the present invention can optionally be provided with other layers as necessary. Specifically, for example, on the outermost layer of the decorative sheet, an easy adhesion layer, an easy slip layer, a hard coat layer, an antistatic layer, an abrasion resistant layer, an antireflection layer, a color correction layer, an ultraviolet absorption layer, a printing layer, Functional layers such as a metal layer, a transparent conductive layer, a gas barrier layer, a hologram layer, a release layer, an adhesive layer, an emboss layer, and an adhesive layer can be provided.

(Molded body)
The molded product of the present invention includes the decorative sheet of the present invention.
The molded body of the present invention can be obtained by molding the decorative sheet of the present invention by any molding method. As such a forming method, for example, various forming methods such as vacuum forming, vacuum pressure forming, plug assist vacuum pressure forming, in-mold forming, insert forming, cold forming, press forming, drawing forming, and the like can be used. Since the molded article of the present invention can be produced by appropriately selecting a desired one of these, it can be produced at a low cost.

  In addition to the decorative sheet of the present invention, the molded article of the present invention can be further provided with other members as necessary. Specifically, for example, members such as a hard coat layer, an embossed layer, a weather resistant layer (UV cut layer), a colored layer, an adhesive layer, and a base resin layer are added by adhesion, fusion, etc. before or after the molding. be able to.

  Since the decorative sheet and the molded body of the present invention can be composed only of a resin without containing a metal, the environmental load is small, the recyclability is excellent, and the electromagnetic wave permeability is excellent. .

  The decorative sheet and the molded body of the present invention are an exterior material in an article such as a mobile phone, a telephone, a personal computer, an audio device, a home appliance, a wireless communication device, a vehicle-mounted part, a building material, a game machine, an amusement device, and a packaging container. It can be used as a member. In particular, the decorative sheet and the molded body of the present invention are devices (wireless information, such as mobile phones, telephones, personal computers, audio devices, home appliances, wireless communication devices, in-vehicle parts, game machines, etc.) It can be preferably used as a decorative part of a communication device. Since the molded article of the present invention has a glossy appearance such as a metallic luster and is excellent in electromagnetic wave permeability, it should not cause an electromagnetic interference like a metallic decorative material containing a conventional metal. Can do. For this reason, when the decorative sheet and the molded body of the present invention are used as a decorative part of an information communication device, the device can be made smaller and thinner, and the degree of freedom in circuit design inside the information communication device can be increased. Can be increased.

  The decorative sheet and the molded body of the present invention are not limited to the above embodiment, and can be modified within the scope of the claims of the present application and within the equivalent scope thereof. Still other optional components can be included.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. In the following, “parts” and “%” relating to the quantity ratio of the components represent parts by weight unless otherwise specified.

<Production Example 1: Production of dextrorotatory cholesteric resin layer>
(1-1: Production of transparent resin base material)
Both surfaces of a film made of an alicyclic olefin polymer (manufactured by Optes, trade name “Zeonor film ZF14-100”, thickness 100 μm) were subjected to corona discharge treatment. An aqueous solution of 5% polyvinyl alcohol was applied to one side of the film using a # 2 wire bar, and the coating film was dried to form an alignment film having a thickness of 0.1 μm. Next, the alignment film was rubbed to prepare a transparent resin substrate having the alignment film.

(1-2: Formation of dextrorotatory cholesteric resin layer)
A cholesteric liquid crystal composition for constituting a cholesteric resin layer was prepared with the following composition.

(Cholesteric liquid crystal composition)
Solid content 40% by weight
Polymerizable liquid crystal compound (Δn (ne-no) = 0.22) 29.1% by weight
Polymerizable non-liquid crystal compound 7.28% by weight (monofunctional acrylate having the following structure (A10))
Photopolymerization initiator (trade name OXE02 manufactured by Ciba Specialty Chemicals) 1.2% by weight
Surfactant (trade name KH-40, manufactured by Seimi Chemical Co., Ltd.) 0.04% by weight
Right-handed chiral agent (trade name LC756, manufactured by BASF) 2.38% by weight
Solvent cyclopentanone 60% by weight

This cholesteric liquid crystal composition was applied to the surface having the alignment film of the transparent resin substrate having the alignment film manufactured in (1-1) above using a # 10 wire bar. The coating film was dried at 100 ° C. for 5 minutes and subjected to orientation aging. The coating film was further irradiated ^{twice with} a weak ultraviolet ray (wavelength 365 nm) of 0.1 to 45 J / cm ² followed by a heating treatment at 100 ° C. for 1 minute, and then in a nitrogen atmosphere. An ultraviolet ray of 2,000 mJ / cm 2 was irradiated to prepare a laminate having a cholesteric resin layer having a dry film thickness of 5 μm (having a layer structure of transparent resin substrate-alignment film-dextrorotatory cholesteric resin layer). When the reflection spectrum of the obtained laminate was measured using a spectroscope (JASCO V-550 manufactured by JASCO Corporation), it has a substantially uniform reflectance of about 40 to 50% in a wavelength band of 400 to 700 nm. It was.

<Production Example 2: Formation of levorotatory cholesteric resin layer)
A levorotatory cholesteric resin layer (transparent resin substrate-alignment film-leftward cholesteric) was operated in the same manner as in Production Example 1 except that a levorotatory chiral agent (trade name LC766, manufactured by BASF) was used as the chiral agent. A layer structure of a resin layer) was prepared.

<Production Example 3: Production of half-wave plate>
A norbornene-based resin pellet (ZEONOR1420, manufactured by Nippon Zeon Co., Ltd.) is dried at 100 ° C. for 5 hours, supplied to an extruder, extruded through a polymer pipe and a polymer filter from a T die onto a casting drum, cooled, An unstretched film having a thickness of 160 μm was obtained.
The unstretched film was supplied to a tenter stretching machine and stretched under the conditions of a stretching temperature of 148 ° C. and a stretching ratio of 3 times to obtain a stretched film having a width of 1300 mm as a half-wave plate. When the retardation of the obtained half-wave plate was measured with a retardation measuring device (manufactured by Oji Scientific Instruments, KOBRA-21SDH), it was 270 nm.

<Production Example 4: Preparation of adhesive layer>
Polyethylene terephthalate separator (trade name “PET50AL” manufactured by Lintec Corporation), SK Dyne 2094 (manufactured by Soken Chemical Co., Ltd., acrylic ester copolymer, solid content 25%, solvent: ethyl acetate / 2-butanone = 93 / 7) A mixture of 400 parts and 1.1 parts of E-AX (manufactured by Soken Chemical Co., Ltd., polyfunctional epoxy crosslinking agent) was applied using a blade with a gap of 200 μm and dried at 100 ° C. for 2 minutes. A laminate having a layer configuration of an adhesive layer having a separator thickness of 20 μm was obtained.

<Example 1>
The surface of the laminate having the levorotatory cholesteric resin layer obtained in Production Example 2 is bonded to the surface of the laminate obtained in Production Example 4 on the adhesive layer side, and then the separator is attached. It peeled and obtained the laminated body (1A) which has the layer structure of transparent resin base material-orientation film-levorotatory cholesteric resin layer-adhesion layer.
Subsequently, the surface on the substrate side of the laminate having the dextrorotatory cholesteric resin layer obtained in Production Example 1 is attached to the surface on the adhesive layer side of the laminate (1A), and these are bonded together to form a transparent resin substrate. -Laminated body (1B) which has the layer structure of-orientation film-levorotatory cholesteric resin layer-adhesion layer-transparent resin base material-alignment film-dextrorotatory cholesteric resin layer was obtained.
Subsequently, the adhesive layer side surface of the laminate obtained in Production Example 4 was attached to both sides of the laminate (1B), and these were bonded together, followed by peeling the separator, and the adhesive layer-transparent resin substrate A laminate (1C) having a layer configuration of -alignment film-left-handed cholesteric resin layer-adhesive layer-transparent resin substrate-alignment film-right-handed cholesteric resin layer-adhesive layer was obtained.
Subsequently, a polyethylene terephthalate film (trade name Lumirror T60, manufactured by Toray Industries, Inc., 100 μm thick) as an outer resin layer is pasted on both surfaces of the laminate (1C), and the outer resin layer-adhesive layer-transparent resin substrate. A decorative sheet (1) having a layer configuration of -alignment film-left-handed cholesteric resin layer-adhesive layer-transparent resin substrate-alignment film-right-handed cholesteric resin layer-adhesive layer-outer resin layer was obtained.

  The obtained decorative sheet (1) was evaluated as follows.

(appearance)
The appearance of the obtained decorative sheet (1) is visually confirmed and visually judged. When the metallic tone is uncolored, “excellent”, and when the metallic tone is slightly colored, “good” "If it is colored or colored depending on the angle, it was defined as" bad ". The results are shown in Table 1.

(Formability)
Molding is performed at 130 ° C. using a chemical packaging machine (FBP-M2, manufactured by CKD), and a total of 10 columnar portions (diameter 9 mm × height 5 mm) are placed on the decorative sheet, 5 vertically and 2 horizontally. Molded in an array with a center spacing of 15 mm. At this time, the decorative sheet that deformed following the cylindrical shape was judged to have high formability, and was defined as “excellent”. Moreover, although the decorative sheet follows the columnar shape, the corner portion is not sufficiently formed as “good”. Furthermore, the decorative sheet that did not follow the cylindrical shape and hardly deformed was judged to have low formability, and was determined as “defective”. The evaluation results are shown in Table 1.

(Delamination)
After embedding the decorative sheet after molding into an epoxy resin, it is sliced using a microtome (RUB-2100, manufactured by Yamato Kogyo Co., Ltd.), and the cross section is observed using a field emission scanning electron microscope S-4700 manufactured by Hitachi, Ltd. did. At this time, the case where delamination did not occur in the decorative sheet was defined as “good”, and the case where delamination occurred was defined as “defective”. The evaluation results are shown in Table 1.

<Example 2>
The surface of the laminate having the dextrorotatory cholesteric resin layer obtained in Production Example 1 is aligned with the surface on the adhesive layer side of the laminate obtained in Production Example 4, and these are then bonded together. Was peeled off to obtain a laminate (2A) having a layer structure of transparent resin substrate-alignment film-dextrorotatory cholesteric resin layer-adhesion layer.
Subsequently, the stretched film obtained in Production Example 3 is bonded to the surface of the laminate (2A) on the adhesive layer side, and the surface on the adhesive layer side of the laminate obtained in Production Example 4 is further combined therewith. These are pasted together, and then the separator is peeled off to obtain a laminate (2B) having a layer structure of transparent resin substrate-alignment film-dextrorotatory cholesteric resin layer-adhesive layer-1 / 2 wavelength plate-adhesive layer. It was.
Subsequently, another surface of the laminate having the dextrorotatory cholesteric resin layer obtained in Production Example 1 is attached to the surface of the laminate (2B) on the adhesive layer side, and these are bonded together. Laminated body having a layer structure of transparent resin substrate-alignment film-dextrorotatory cholesteric resin layer-adhesive layer-1 / 2 wavelength plate-adhesion layer-transparent resin substrate-alignment film-dextrorotatory cholesteric resin layer ( 2C) was obtained.
Subsequently, the both surfaces of the laminate (2C) are combined with the surface of the laminate obtained in Production Example 4 on the adhesive layer side, and then the separator is peeled off. Adhesive layer-transparent resin substrate -Laminated body (2D) having a layer structure of orientation film-dextrorotatory cholesteric resin layer-adhesive layer-half-wave plate-adhesive layer-transparent resin substrate-orientation film-dextrorotatory cholesteric resin layer-adhesive layer Got.
Subsequently, a polyethylene terephthalate film (manufactured by Toray Industries, Inc., trade name Lumirror T60, thickness 100 μm) is attached to each of both surfaces of the laminate (2D), and the outer resin layer-adhesive layer-transparent. Layer structure of resin substrate-alignment film-dextrorotatory cholesteric resin layer-adhesive layer-1 / 2 wavelength plate-adhesion layer-transparent resin substrate-alignment film-dextrorotatory cholesteric resin layer-adhesion layer-outer resin layer A decorative sheet (2) having

  The obtained decorative sheet (2) was evaluated in the same manner as in Example 1. The results are shown in Table 1.

<Example 3>
The laminated body (1B) produced in Example 1 was evaluated as it was with the decorative sheet (1). The results are shown in Table 1.

<Example 4>
The laminate (2C) produced in Example 2 was evaluated as it was with the decorative sheet (2). The results are shown in Table 1.

<Comparative Example 1>
And in the same manner as in Example 1 of Patent Document 1 to obtain a film, it was evaluated the same as with the evaluation of the decorative sheet of Example 1-4. The results are shown in Table 1.

  From the results of Table 1, the decorative sheet of the present invention is a sheet composed of a small number of layers, but can exhibit an appearance having a metallic luster equivalent to a film of a comparative example composed of a large number of layers. I understand. Furthermore, it turns out that the decorating sheet of Example 1 and 2 which has an outer side resin layer on both surfaces also has a favorable moldability, and is very useful as a member for decorating articles | goods.

It is a longitudinal section showing an example of a decorating sheet of the present invention roughly. It is a longitudinal cross-sectional view which shows schematically another example of the decorating sheet of this invention.

Explanation of symbols

11, 31 Incident light 11R, 13R, 14R, 31R Right circularly polarized light 12L, 13L, 14L, 15L, 32L, 33L, 34L Left circularly polarized light 20 Laminate 21 First cholesteric resin layer 22 1/2 wavelength plate 23, 43 Second cholesteric resin layer 24, 25 Outer resin layer 51, 52 surface 100, 200 Decorative sheet

Claims (6)

A decorative sheet including a laminate including a resin layer having a first cholesteric regularity and a resin layer having a second cholesteric regularity,
The resin layer having the first cholesteric regularity is a layer that transmits the first circularly polarized light and reflects the second circularly polarized light that is different from the first circularly polarized light,
The second cholesteric resin layer is disposed so as to reflect at least a part of the first circularly polarized light transmitted through the resin layer having the first cholesteric regularity ,
The first and the resin layer having a second cholesteric regularity, that have a stepwise or continuously helical structure pitch changes in the thickness direction, the decorative sheet.   A half-wave plate provided between the resin layer having the first cholesteric regularity and the resin layer having the second cholesteric regularity;
  The decorative sheet according to claim 1, wherein the twist direction of the resin layer having the first cholesteric regularity is the same direction as the twist direction of the resin layer having the second cholesteric regularity.   The decorative sheet according to claim 1, wherein a twist direction of the resin layer having the first cholesteric regularity is opposite to a twist direction of the resin layer having the second cholesteric regularity.   The decorative sheet according to any one of claims 1 to 3, further comprising a pair of outer resin layers as both outer layers of the laminate.   The decorative sheet according to any one of claims 1 to 4, wherein an intrinsic birefringence value? N of the resin layers having the first and second cholesteric regularities is 0.2 or more.   The molded object containing the decorating sheet of any one of Claims 1-5.

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