JP6564666B2 - Decorative sheet and laminated sheet for decoration - Google Patents

Description

  The present invention relates to a decorative sheet having an olefin-based resin as a main component, and particularly to a decorative sheet having excellent low-temperature formability, and a decorative laminated sheet having the decorative sheet.

  Conventionally, printing, painting, vapor deposition, plating, and the like have been used for decorating the surface of a housing made of metal, glass, plastic, etc., such as home appliances, automobile parts, OA equipment, and mobile phones. However, in recent years, the product forms have become more complex, making it difficult to decorate with printing, painting, etc., and the demand for solvent coating replacement and plating replacement has increased due to environmental load problems. Development of decoration technology using decorative sheets is underway.

  As a decorative sheet, for example, an unstretched sheet using an amorphous polyester resin (Patent Document 1) or a sheet in which a polyolefin resin film is bonded to one side of an unstretched polyester film (Patent Document 2) is proposed. Has been. Further, a sheet (Patent Document 3) in which an olefin-based resin is blended with a cyclic olefin-based resin as a main component has been proposed as a decorative sheet in consideration of sheet breakage, self-holding property, and the like.

JP 2007-246910 A JP 2006-103176 A JP 2013-071419 A

  However, the technique disclosed in Patent Document 1 has a problem that it has poor solvent resistance and cannot withstand printing, coating processing, and the like. Moreover, in the technique disclosed in Patent Document 2, an adhesive is required when bonding an unstretched polyester film and a polyolefin-based resin film, and a complicated process is required. In addition, in the technique disclosed in Patent Document 3, there is no problem when the casing is made of metal because the processing temperature is high, but when the casing is made of resin, the heat resistance is inferior, so in the decoration process, Problems such as deformation of the housing and misalignment of the decoration occurred, which was not sufficient in terms of formability at low temperatures.

  The present invention has been made in view of the above circumstances, and the problem to be solved is to provide a decorative sheet and a laminated sheet for decoration that are excellent in workability, formability, and productivity, and in particular, low-temperature formability. An object of the present invention is to provide a decorative sheet and a decorative laminated sheet.

  As a result of intensive studies in view of the above problems, the present inventors have found that the above problems can be easily solved by adopting a specific configuration, and the present invention has been completed.

  That is, the first aspect of the present invention is a decorative sheet characterized by comprising an olefin resin as a main component and having a tensile elastic modulus at 90 ° C. of 30 MPa to 110 MPa.

  In the first aspect of the present invention, the olefin resin preferably contains at least a polypropylene resin (A) having a melting point of 110 ° C. or higher and 135 ° C. or lower and a cyclic olefin resin (B).

  In the first aspect of the present invention, the cyclic olefin resin (B) preferably has a glass transition temperature of 40 ° C. or higher and 100 ° C. or lower.

  1st aspect of this invention WHEREIN: The mass ratio of the said polypropylene resin (A) and the said cyclic olefin resin (B) is (A) :( B) = 90: 10-40: 60. preferable.

  1st aspect of this invention WHEREIN: It is preferable that melting | fusing point measured at the temperature increase rate of 10 degrees C / min in differential scanning calorimetry is 110 degreeC or more and 135 degrees C or less.

  In the first aspect of the present invention, in the tensile test at 90 ° C. according to JIS K 7127, the ratio of the tensile strength at a tensile elongation of 500% to the tensile strength at a tensile elongation of 200% is 1 or more and 1.3 or less. It is preferable that

  The decorative sheet of the present invention may be a single layer sheet or a laminated sheet of two or more layers.

  The second aspect of the present invention is a decorative laminated sheet having at least one decorative sheet according to the first aspect of the present invention.

  The decorative sheet and decorative laminated sheet of the present invention can be preferably used for molding transfer.

  According to the present invention, even when a molded article whose casing cannot withstand a decoration process at a high temperature, for example, a decoration process under conditions at a low temperature of 80 to 110 ° C. is required, the sheet is loosened. Therefore, it is possible to provide a decorative sheet and a decorative laminated sheet that have sufficient formability and are excellent in workability and productivity.

  Hereinafter, the present invention will be described in detail. However, the scope of the present invention is not limited to the embodiments described below. Unless otherwise specified, the notation “A to B” for numerical values A and B means “A to B”. In this notation, when a unit is attached to only the numerical value B, the unit is also applied to the numerical value A.

  The decorative sheet of the present invention can solve this problem by having an olefin resin as a main component and having a tensile elastic modulus at 90 ° C. of 30 MPa to 110 MPa.

  In the present invention, the expression “main component” includes the intention to allow other components to be contained within a range that does not interfere with the function of the main component, unless otherwise specified. Although the content ratio of the component is not specified, the main component includes 50% by mass or more, preferably 70% by mass or more, particularly preferably 90% by mass or more (including 100% by mass) in the composition. To do.

  In the decorative sheet of the present invention, it is important that the tensile elastic modulus at 90 ° C. is 30 MPa or more and 110 MPa or less, preferably 40 MPa or more and 100 MPa or less, and more preferably 40 MPa or more and 90 MPa or less. By setting the tensile elastic modulus at 90 ° C. to 30 MPa or more, the rigidity during the decorating step can be made preferable, and wrinkling of the sheet can be suppressed. Moreover, it can suppress that a moldability deteriorates by setting it as 110 Mpa or less, and the followable | trackability to a molded article and uniform moldability fall.

  The olefin resin of the present invention preferably contains a polypropylene resin (A) having a melting point of 110 ° C. or higher and 135 ° C. or lower and a cyclic olefin resin (B).

  Examples of the polypropylene resin (A) that can be used in the present invention include Ziegler-Natta catalysts, metallocene catalysts, and more specifically, homopolypropylene resins, block polypropylene resins, and random polypropylene resins.

  Examples of the polypropylene resin (A) that can be used in the present invention include a propylene homopolymer (homopolypropylene), a propylene copolymer, a reactor-type polypropylene thermoplastic elastomer, and a mixture thereof.

  The propylene copolymer includes a random copolymer of propylene and ethylene or other α-olefin (random polypropylene), a block copolymer (block polypropylene), a block copolymer containing a rubber component, or a graft copolymer. Examples include coalescence. The other α-olefin copolymerizable with propylene is preferably one having 4 to 12 carbon atoms, such as 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 4 -Methyl-1-pentene, 1-decene, etc. are mentioned, The 1 type (s) or 2 or more types of mixture is used. Usually, the mixing ratio of α-olefin is about 1 to 10% by weight with respect to propylene.

  The preferred polypropylene resin (A) having a melting point of 110 ° C. or more and 135 ° C. or less that can be used in the present invention is not particularly limited as long as it satisfies the above melting point, but is preferably a random polypropylene resin, more preferably a metallocene. A metallocene random polypropylene resin obtained by polymerization using a system catalyst can be used.

  The polypropylene resin (A) that can be used in the present invention preferably has a melting point in the range of 110 ° C. to 135 ° C., more preferably in the range of 115 ° C. to 130 ° C., and 118 ° C. to 128 ° C. More preferably, it is the range. By setting the melting point to 110 ° C. or higher, it is possible to suppress the slack of the decorative sheet during the decoration process or the process of forming the decoration layer. Further, by setting the melting point to 135 ° C. or lower, the moldability at low temperature can be improved.

  Examples of the cyclic olefin-based resin (B) that can be used in the present invention include cyclic olefin ring-opening (co) polymers, cyclic olefin ring-opening (co-polymers) of random copolymers of cyclic olefins and α-olefins such as ethylene and propylene. ) Polymer hydrogenated products and graft modified products of these (co) polymers. Among them, a random copolymer of a cyclic olefin and ethylene is preferable from the viewpoint of productivity and processability, and more specifically, bicyclo [2,2,1] hept-2-ene (norbornene) is preferable as the cyclic olefin.

  The cyclic olefin resin (B) that can be used in the present invention preferably has a glass transition temperature of 40 ° C. or higher and 100 ° C. or lower, obtained by differential scanning calorimetry (condition: temperature increase rate 10 ° C./min), more preferably. Is from 50 ° C. to 95 ° C., more preferably from 55 ° C. to 90 ° C. By setting the glass transition temperature to 40 ° C. or higher, heat resistance can be imparted in the process of forming the decorative layer, and wrinkles can be suppressed. Moreover, it can suppress that rigidity becomes high too much and a moldability falls by setting a glass transition temperature to 100 degrees C or less.

  In the decorative sheet of the present invention, the mass ratio of the polypropylene resin (A) and the cyclic olefin resin (B) is preferably (A) :( B) = 90: 10-40: 60, It is preferably 85:25 to 45:55, and more preferably 80:20 to 48:52. By setting the mass ratio of the polypropylene-based resin (A) and the cyclic olefin-based resin (B) as described above, rigidity becomes preferable during the decoration process, and wrinkles can be suppressed. Furthermore, it can suppress more that rigidity becomes high too much and a moldability falls.

The melting point of the decorative sheet of the present invention is preferably in the range of 110 ° C to 135 ° C, more preferably in the range of 115 ° C to 130 ° C, and in the range of 118 ° C to 128 ° C. More preferably. By setting the melting point to 110 ° C. or higher, it is possible to suppress the slack of the decorative sheet during the decoration process or the process of forming the decoration layer. Further, by setting the melting point to 135 ° C. or lower, the moldability at low temperature can be improved.
The melting point described here refers to the melting point derived from the one having the largest amount of heat of fusion among the melting points obtained from differential scanning calorimetry (condition: heating rate 10 ° C./min).

  In addition, the decorative sheet of the present invention has a tensile strength at a tensile elongation of 500% obtained by a tensile test (thickness: 200 μm) at 90 ° C. in a test method based on JIS K 7127 of 20 N or less. Preferably, it is 15N or less, more preferably 10N or less, and particularly preferably 6N or less. By setting the tensile strength at a tensile elongation of 500% at 90 ° C. to 20 N or less, it is possible to further suppress deterioration of formability and lowering of followability to molded products and uniform formability. It is possible to further suppress my entry.

  Moreover, the decorative sheet of the present invention is a tensile elongation of 500 with respect to a tensile strength at a tensile elongation of 200% obtained by a tensile test (thickness: 200 μm) under a test condition of 90 ° C. in a test method based on JIS K 7127. The ratio of the tensile strength in% is preferably 1 or more and 1.3 or less, more preferably 1 or more and 1.2 or less. By setting the ratio of the tensile strength within the above range, a stable strength can be maintained in the stretched state, the stability during stretching can be preferred, and the decorative sheet can be used during the decorating process. Since it suppresses that it breaks and it becomes difficult to orientate the sheet for decoration in the case of a decoration process, the tear of the sheet for decoration after fabrication can be controlled.

  The thickness of the decorative sheet of the present invention is not particularly limited, but is preferably 30 μm or more and 500 μm or less, more preferably 50 μm or more and 400 μm or less, and further preferably 100 μm or more and 300 μm or less. By setting the thickness of the sheet to 30 μm or more, rigidity can be secured and wrinkles are difficult to enter. In addition, by setting the thickness of the sheet to 500 μm or less, it is possible to prevent the rigidity from being excessively increased and the formability from being lowered and the manufacturing cost from being increased.

The decorative sheet of the present invention may be a single layer sheet or a laminated sheet of two or more layers. Here, when the decorative sheet of the present invention is a laminated sheet of two or more layers, it means that the entire laminated sheet satisfies the above-mentioned regulations such as tensile elongation, tensile elastic modulus, strength, and thickness. Moreover, another layer may be laminated | stacked on the sheet | seat for decorating of this invention, and you may use as a laminated sheet for decorating. In this case, the lamination sheet for decorating should just have at least 1 layer of the sheet for decorating prescribed | regulated to this invention. For example, a decorative sheet defined in the present invention may be used as a base material layer, and an olefin-based resin or other resin may be used to form a multilayer laminated decorative sheet of two layers and / or three or more layers.
In addition, the decorative sheet defined in the present invention may be an intermediate layer, and an olefinic resin or other resin may be used for the front and back layers to form a multi-layer decorative laminate sheet of three layers and / or three or more layers. it can.

  An additive can be added to the decorative sheet of the present invention as long as the function is not impaired. Examples of the additives include antioxidants, stabilizers, flame retardants, antistatic agents, plasticizers, antiblocking agents, slip agents, processing aids, ultraviolet absorbers, colorants such as pigments and dyes, and the like.

  The decorative sheet of the present invention can be used as it is by decorating the decorative sheet on the surface of the molded product. Moreover, a decoration layer can be transcribe | transferred to a molded object by using the lamination sheet for decoration which laminated | stacked the decoration layer on the sheet for decoration of this invention. Here, the decorative layer is a layer that imparts design properties such as coloring, design, wood grain, matte tone, metal tone, unevenness, and pearl tone. Since the decorative layer is bonded to the surface of the molded product as the decorative sheet itself of the present invention, or is transferred to the molded body through the decorative laminated sheet, it becomes the final outermost layer of the molded product. . Therefore, when bonding on the surface of a molded article as the decorative sheet itself, it is preferable to have a topcoat layer on the surface opposite to the side to be bonded. In addition, when using a decorative laminated sheet, the decorative layer has a top coat layer on the decorative sheet side, and in consideration of the adhesion between the decorative layer and the molded body, it is bonded to the molded body side. A layered configuration is preferred. Examples of preferred forms as the decorative layer include the topcoat layer / design layer / adhesive layer in order from the decorative sheet side, but are not particularly defined and are appropriately within the range not impairing the object of the present invention. It can be made into a form.

  When transferring the decorative layer to the molded product using the decorative laminate sheet, if the mold release property between the decorative sheet and the top coat layer is poor, the space between the decorative sheet and the top coat layer A release layer may be provided.

  Known resins can be used as the topcoat layer, and examples thereof include thermoplastic resins, thermosetting resins, ultraviolet curable resins, and more specifically acrylic resins, polyester resins, and polyvinyl chloride. Resin, cellulose resin, rubber resin, polyurethane resin, polyvinyl acetate resin, silicone resin, fluorine resin, vinyl chloride-vinyl acetate copolymer resin, ethylene-vinyl acetate copolymer resin, etc. It is done.

  As a method of forming the topcoat layer, in addition to the roller coating method, brush coating method, spray coating method, dip coating method, gravure coater method, die coater method, comma coater method, bar coater method, knife coater method Is mentioned. In addition, the method of directly forming the topcoat layer, the method of once forming the carrier film, and the method of transferring, etc. are mentioned, but if it is necessary to dry at a high temperature after the formation, it is once formed on the carrier film, A method of transferring is preferred.

  Examples of the design layer include a printed layer, a colored layer, and a metal vapor deposition layer. As a method for forming the design layer, printing methods such as offset printing method, gravure printing method and screen printing method, coating methods such as gravure coater method, die coater method, comma coater method, bar coater method, knife coater method, vacuum deposition, etc. And vapor deposition such as EB vapor deposition, sputtering, and ion plating. Although the formation method of a design layer is not specifically limited, A suitable formation method can be selected according to a design feeling.

  Examples of the adhesive layer include a heat-sensitive adhesive, a pressure-sensitive adhesive, an ultraviolet curable adhesive, and a thermosetting adhesive. Although an adhesive layer is not specifically limited, A suitable adhesive agent can be selected according to a molded object and a use. As the method for forming the adhesive layer, printing methods such as offset printing method, gravure printing method, screen printing method, gravure coater method, die coater method, comma coater method, bar coater method, knife coater method, hot melt coating method, etc. The coating method is mentioned.

  Examples of the present invention are shown below, but the present invention is not limited to these examples.

<Production of decorative sheet>
Example 1
Random polypropylene resin ((A-1): Nippon Polypro, Wintech WFX6, melting point 126 ° C., heat of fusion ΔHm = 59.1 J / g) 70% by mass and cyclic olefin resin ((B-1): poly Example of having a thickness of 200 μm, blended with 30% by mass of Plastics, TOPAS 9506F-500, glass transition temperature 65 ° C.), and extruded at a resin temperature of 200 ° C. by a T-die method using a 40 mmφ single screw extruder. A decorative sheet according to No. 1 was prepared and evaluated later.

(Example 2)
The composition of the intermediate layer is 60% by mass of the random polypropylene resin (A-1), 40% by mass of the cyclic olefin resin (B-1), and the composition of the front / back layer is 100% by mass of the random polypropylene resin (A-1). %, Using 1 extruder of 50 mmφ and 2 extruders of 35 mmφ, and extrusion molding under the condition of a resin temperature of 220 ° C. by the T-die method, and decorating according to Example 2 having a three-layer thickness of 200 μm Sheets were prepared and evaluated as described below.
In addition, the thickness ratio of each layer in the case of three layers was produced by surface layer: intermediate layer: back layer = 5: 90: 5.

(Example 3)
The decorative sheet according to Example 3 was prepared in the same manner as in Example 1 except that the blending was 50% by mass of random polypropylene resin (A-1) and 50% by mass of cyclic olefin resin (B-1). It produced and evaluated below.

(Comparative Example 1)
Except for blending 100% by mass of homopolypropylene resin ((A-3): Nippon Polypro, Novatec PP FY6HA, melting point 167 ° C., heat of fusion ΔHm = 96.7 J / g), the same as in Example 1 The sheet for decorating which concerns on the comparative example 1 was produced by the method, and the evaluation mentioned later was performed.

(Comparative Example 2)
The decorative sheet according to Comparative Example 2 was prepared in the same manner as in Example 1 except that the composition was 60% by mass of homopolypropylene resin (A-3) and 40% by mass of cyclic olefin resin (B-1). It produced and evaluated below.

(Comparative Example 3)
Except for blending the homopolypropylene resin (A-3) 40% by mass, the cyclic olefin resin ((B-2): manufactured by Polyplastics, TOPAS 7010F-600, glass transition temperature 110 ° C.) 60% by mass, A decorative sheet according to Comparative Example 3 was produced in the same manner as in Example 1 and evaluated later.

(Comparative Example 4)
The decorative sheet according to Comparative Example 4 was prepared in the same manner as in Example 1 except that the composition was 60% by mass of homopolypropylene resin (A-3) and 40% by mass of cyclic olefin resin (B-2). It produced and evaluated below.

(Comparative Example 5)
Random polypropylene resin ((A-2): Nippon Polypro, Wintech WFW5T, melting point 144 ° C., heat of fusion ΔHm = 78.5 J / g) 60% by mass, cyclic olefin resin (B-1) 40 A decorative sheet according to Comparative Example 5 was produced in the same manner as in Example 1 except that the mass% was used, and evaluation described later was performed.

<Evaluation items>
The following evaluation was performed about the obtained sheet | seat for decorating. Table 1 shows the configuration and evaluation results of the decorative sheet.

(1) Tensile modulus at 90 ° C. Samples of test pieces were collected from the obtained decorative sheet in a strip shape with a width of 5 mm, a thickness of 200 μm, and an initial length of 300 mm. Using a machine AGS-X, a tensile test was performed under a condition of a tensile speed of 5 mm / min in an atmosphere at 90 ° C., and the initial elastic region slope obtained by the tensile test was defined as a tensile elastic modulus.

(2) Tensile strength at 90 ° C. with a tensile elongation of 200% and 500% The obtained 200 μm decorative sheet was subjected to a method according to JIS K 7127 (test piece shape: test piece type 5) in a 90 ° C. atmosphere. A tensile test was performed to measure the tensile strength at an elongation of 200% and 500%, and the ratio of the tensile strength at a tensile elongation of 500% to the tensile strength at 200% was calculated.

(3) Melting point The melting point of the obtained decorative sheet was calculated from differential scanning calorimetry by a method according to JIS K2721.
The calorific value is the result of the first run.

(4) Formability A sample obtained by cutting the obtained decorative sheet into a size of 550 mm × 550 mm was used using a three-dimensional vacuum heating molding machine (TOM molding machine / NGF-0404-S) manufactured by Fuse Vacuum Co., Ltd. Then, it was heated to a temperature of 90 ° C., and vacuum / pressure forming (pressure: 0.2 MPa) was performed along a mold heated to 50 ° C. to obtain a molded body. The state of the obtained molded body was evaluated according to the following criteria for uniform moldability, mold followability, wrinkling and tearing of the decorative sheet.
i) Uniform moldability ○: Molded without thickness unevenness.
X: There is a portion that is elongated and thin.
ii) Follow-up property ○: Molded sharply with respect to the mold.
(Triangle | delta): There exists a place which cannot be following partially with respect to a metal mold | die.
X: Not able to follow the mold.
iii) Wrinkle ○: Molded without wrinkles.
Δ: One or two wrinkles are found near the corner of the mold.
×: Wrinkles are observed in 3 or more places
iv) Break ○: The decorative sheet after molding is not torn.
X: The decorative sheet after molding is broken.

<Result>
From Table 1, it turns out that the sheet | seat for decorating of this invention which concerns on Examples 1-3 is excellent in the moldability in low temperature. On the other hand, the decorative sheet according to Comparative Examples 1 to 5 having a tensile elastic modulus of 90 ° C outside the range of the present invention was inferior in moldability.

  The decorative sheet of the present invention comprises an olefin-based resin as a main component, and has a tensile elastic modulus at 90 ° C. of 30 MPa to 110 MPa. In the method, it has sufficient formability in the decoration process at a low temperature of 80 to 110 ° C. and is excellent in workability and productivity. Therefore, it is not limited to metal, glass, ceramic, etc. It can be suitably used for decoration on the body.

Claims (9)

The main component is an olefin resin containing at least a polypropylene resin (A) having a melting point of 110 ° C. or more and 135 ° C. or less and a cyclic olefin resin (B), and the tensile elastic modulus at 90 ° C. is 30 MPa or more and 110 MPa or less. A decorative sheet characterized by that. 2. The decorative sheet according to claim 1 , wherein the cyclic olefin-based resin (B) has a glass transition temperature of 40 ° C. or higher and 100 ° C. or lower. The mass ratio of the polypropylene resin (A) and the cyclic olefin resin (B) is (A) :( B) = 90: 10 to 40:60, according to claim 1 or 2 . The sheet for decorating of description. The melting point measured at a heating rate of 10 ° C / min in differential scanning calorimetry is 110 ° C or higher and 135 ° C or lower, and the decorative sheet according to any one of claims 1 to 3 . The ratio of the tensile strength at a tensile elongation of 500% to the tensile strength at a tensile elongation of 200% in a tensile test at 90 ° C according to JIS K 7127 is 1 or more and 1.3 or less. The sheet for decoration of any one of 1-4 . The decorative sheet according to any one of claims 1 to 5 , which is a single-layer sheet or a laminated sheet of two or more layers. The laminated sheet for decorating which has at least 1 layer of the sheet for decorating of any one of Claims 1-6 . The decorative sheet according to any one of claims 1 to 6 , which is used for molding transfer. The laminated sheet for decorating according to claim 7 , which is used for molding transfer.