# US 2010/0165472 A1 · Reflecting sheet

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- Number: US 2010/0165472 A1
- Document ID: US20100165472A1
- Status: Published application
- Kind: A1
- Application number: 12/663,171
- Filed: 2008-06-05
- Published: 2010-07-01
- Earliest claimed: 2007-06-05
- Assignees: Asahi Kasei E-Materials Corporation
- Inventors: Shinya Hamasaki; Yuuichi Arito; Kenji Takasa; Tsumoru Kuwabara
- Web page: https://patentgrep.com/patent/US20100165472A1

## CPC

- B32B 27/32: comprising polyolefins {(comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30)}
- B32B 3/26: characterised by a particular shape of the outline of the cross-section of a continuous layer; characterised by a layer with cavities or internal voids {(foam layer B32B5/18; layer of synthetic resin characterised by fillers that create voids or cavities B32B27/205); characterised by an apertured layer}
- B32B 3/28: characterised by a layer comprising a deformed thin sheet {, i.e. the layer having its entire thickness deformed out of the plane}, e.g. corrugated, crumpled (B32B29/08 takes precedence)
- B32B 7/023: Optical properties
- B32B 27/08: of synthetic resin
- B32B 27/18: characterised by the use of special additives
- B32B 27/365: {comprising polycarbonates}
- C08L 23/02: not modified by chemical after-treatment
- C08L 23/10: Homopolymers or copolymers of propene
- G02B 5/10: with curved faces
- B29C 55/023: {using multilayered plates or sheets}
- B29C 55/12: biaxial
- B29K 2023/00: Use of polyalkenes {or derivatives thereof} as moulding material
- B29K 2105/16: Fillers
- B29K 2995/003: Reflective
- B32B 2250/24: All layers being polymeric
- B32B 2264/10: Inorganic particles
- B32B 2264/102: Oxide or hydroxide
- B32B 2270/00: Resin or rubber layer containing a blend of at least two different polymers
- B32B 2307/40: having particular optical properties
- B32B 2307/416: Reflective
- B32B 2307/51: Elastic
- B32B 2307/514: Oriented
- B32B 2307/72: Density
- B32B 2307/736: Shrinkable
- B32B 2457/202: LCD, i.e. liquid crystal displays
- C08K 3/22: of metals
- C08L 69/00: Compositions of polycarbonates; Compositions of derivatives of polycarbonates
- G02B 5/045: {Prism arrays}
- G02B 6/0055: {Reflecting element, sheet or layer}
- G02F 1/133603: {with LEDs}
- G02F 1/133605: {including specially adapted reflectors}
- Y10T 428/24355: Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]
- Y10T 428/24612: Composite web or sheet
- Y10T 428/249991: Synthetic resin or natural rubbers
- B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09)
- G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A reflecting sheet of the invention includes at least a surface layer portion and an inner layer portion, where the surface layer portion contains at least 0.3 g/m2 to 20 g/m2 of an inorganic powder and a polyolefin resin (C), the inner layer portion contains a polyolefin resin (A) and at least one kind of resins (B) incompatible with the polyolefin resin (A) at temperatures enabling stretching of the polyolefin resin(A), the surface layer portion meets (n1−n2)/n2≧0.20 (n1: refractive index of the inorganic powder, n2: refractive index of the polyolefin resin (C)), and the inner layer portion has voids.

## Claims

### Claim 1

A reflecting sheet including at least a surface layer portion and an inner layer portion,
wherein the surface layer portion contains at least 0.3 g/m2 to 20 g/m2 of an inorganic powder and a polyolefin resin (C), the inner layer portion contains a polyolefin resin (A) and at least one kind of resins (B) incompatible with the polyolefin resin (A) at temperatures enabling stretching of the polyolefin resin(A), the surface layer portion meets (n1−n2)/n2≧0.20 (n1: refractive index of the inorganic powder, (n1: refractive index of the polyolefin resin (C)), and the inner layer portion has voids.

### Claim 2 (depends on 1)

The reflecting sheet according to claim 1, wherein the inorganic powder includes zinc oxide and/or titanium oxide.

### Claim 3 (depends on 1)

The reflecting sheet according to claim 1, wherein the modulus of elasticity of the resins (B) is higher the modulus of elasticity of the polyolefin resin (A).

### Claim 4 (depends on 1)

The reflecting sheet according to claim 1, wherein the resins (B) include polycarbonate resins.

### Claim 5 (depends on 1)

The reflecting sheet according to claim 1, wherein the polyolefin resin (A) is a polypropylene resin.

### Claim 6 (depends on 1)

The reflecting sheet according to claim 1, wherein the polyolefin resin (C) is a polypropylene resin.

### Claim 7 (depends on 1)

The reflecting sheet according to claim 1, wherein a content of the polyolefin resin (A) in the inner layer portion ranges from 30 percent to 80 percent by weight, and a content of the resins (B) in the inner layer portion ranges from 20 percent to 70 percent by weight.

### Claim 8 (depends on 1)

The reflecting sheet according to claim 1, wherein the surface layer portion contains 80 percent by volume or more of the polyolefin resin (C).

### Claim 9 (depends on 1)

The reflecting sheet according to claim 1, wherein a density ranges from 0.1 g/cm3 to 0.75 g/cm3.

### Claim 10 (depends on 9)

The reflecting sheet according to claim 9, wherein the density ranges from 0.15 g/cm3 to 0.5 g/m3.

### Claim 11 (depends on 1)

The reflecting sheet according to claim 1, wherein an average total reflection index is 90% or more, and assuming that the total reflection index is R1 in the direction in which the total reflection index is the maximum and that the total reflection index is R2 in the direction perpendicular to the direction of R1, the sheet has anisotropy of the total reflection index of 2.0% or less, the anisotropy being a difference between R1 and R2.

### Claim 12 (depends on 11)

The reflecting sheet according to claim 11, wherein the average total reflection index is 95% or more.

### Claim 13 (depends on 1)

The reflecting sheet according to claim 1, wherein a structure of the reflecting sheet is a three-layer structure of surface layer portion/inner layer portion/surface layer portion.

### Claim 14 (depends on 1)

The reflecting sheet according to claim 1, wherein entire weighing of the reflecting sheet ranges from 10 g/m2 to 500 g/m2.

### Claim 15 (depends on 1)

The reflecting sheet according to claim 1, wherein a thickness of the surface layer portion ranges from 2 μm to 90 μm.

### Claim 16 (depends on 1)

The reflecting sheet according to claim 1, wherein a yellowing factor is 10 or less in a high pressure mercury lamp light resistance test.

### Claim 17 (depends on 1)

The reflecting sheet according to claim 1, wherein a heat shrinkage percentage at 150° C. for 30 minutes is 15% or less in each of the longitudinal direction (MD) and the transverse direction (TD).

### Claim 18 (depends on 1)

The reflecting sheet according to claim 1, wherein the surface layer portion has a fine three-dimensional structure surface.

### Claim 19 (depends on 18)

The reflecting sheet according to claim 18, wherein an isotactic index (mmmm pentad %) of the polyolefin resin (C) in the surface layer portion ranges 55 mole % to 85 mole %.

### Claim 20 (depends on 18)

The reflecting sheet according to claim 18, wherein the fine three-dimensional structure surface is a reflecting surface to control reflection directions.

### Claim 21 (depends on 18)

The reflecting sheet according to claim 18, wherein a section including a vertex of a single structure constituting the fine three-dimensional structure surface is substantially a triangle, and a vertex angle ranges from 30° to 150°.

### Claim 22 (depends on 21)

The reflecting sheet according to claim 21, wherein a base of the triangle ranges from 10 μm to 1000 μm, and a height of the triangle ranges from 10 μm to 150 μm.

### Claim 23 (depends on 18)

The reflecting sheet according to claim 18, wherein the fine three-dimensional structure surface is formed by heat forming.

### Claim 24 (depends on 1)

The reflecting sheet according to claim 1, wherein the reflecting sheet has convex portions at least on one of main surfaces.

### Claim 25 (depends on 24)

The reflecting sheet according to claim 24, wherein a shape of each of the convex portions includes at least a part of a spherical form or a poly-sided pyramid form, and a form where the vertex of a poly-sided pyramid is made flat or arc form.

### Claim 26 (depends on 24)

The reflecting sheet according to claim 24, wherein the shape is obtained by heat forming.

### Claim 27 (depends on 1)

The reflecting sheet according to claim 1, wherein the reflecting sheet has a plurality of concave portions and ridge lines among the concave portions, each of the concave portions has a bottom having a hole portion to expose an emitter, and reflecting surfaces connecting the bottom and the ridge lines, and the reflecting sheet has a plurality of bulge portions on the ridge lines.

### Claim 28 (depends on 27)

The reflecting sheet according to claim 27, wherein each of the bulge portions is foamed of a part of a semi-sphere, a sphere or an elliptic sphere.

### Claim 29 (depends on 27)

The reflecting sheet according to claim 27, wherein the bulge portions are provided in positions where the ridge lines interest one another.

### Claim 30 (depends on 27)

The reflecting sheet according to claim 27, wherein a height of each of the bulge portions ranges from 1/20 to ½ a depth of each of the bulge portions.

### Claim 31 (depends on 27)

The reflecting sheet according to claim 27, wherein a width of each of the ridge lines ranges from 1/100 to ⅕ the maximum width of each of the concave portions.

### Claim 32 (depends on 27)

The reflecting sheet according to claim 27, wherein the shape of each of the concave portions is a polygon in a planar view.

### Claim 33 (depends on 27)

The reflecting sheet according to claim 27, wherein a shape of each of the concave portions is a rectangle in a planar view, and each of the bulge portions is provided in a position where the ridge lines intersect one another.

### Claim 34

A manufacturing method of a reflecting sheet having at least a surface layer portion and an inner layer portion, comprising the steps of:
(i) co-extruding a resin component (a) containing a polyolefin resin (A) and at least one kind of resins (B) incompatible with the polyolefin resin (A) at temperatures enabling stretching of the polyolefin resin (A), and a resin composition (b) containing at least a polyolefin resin (C) and an inorganic powder, and
(ii) performing two-way stretching on a sheet obtained in step (i) to cleave,
wherein (n1−n2)/n2≧0.20(n1: refractive index of the inorganic powder, m: refractive index of the polyolefin resin (C)) is met.

### Claim 35 (depends on 34)

The manufacturing method of the reflecting sheet according to claim 34, wherein the reflecting sheet has a three-layer structure, the resin composition (b) is supplied to a die as a raw material of the surface layer portion, and the resin composition (a) is supplied to the die as a raw material of the inner layer portion to perform co-extrusion.

### Claim 36 (depends on 34)

The manufacturing method of the reflecting sheet according to claim 34, wherein the inorganic powder is contained in an amount of from 2 percent to 70 percent by weight relative to the resin composition (b) in the surface layer portion.

### Claim 37 (depends on 34)

The manufacturing method of the reflecting sheet according to claim 34, wherein the inorganic powder includes zinc oxide and/or titanium oxide.

### Claim 38 (depends on 34)

The manufacturing method of the reflecting sheet according to claim 34, wherein the modulus of elasticity of the resins (B) is higher the modulus of elasticity of the polyolefin resin (A).

### Claim 39 (depends on 34)

The manufacturing method of the reflecting sheet according to claim 34, wherein the resins (B) are polycarbonate resins.

### Claim 40 (depends on 34)

The manufacturing method of the reflecting sheet according to claim 34, wherein the polyolefin resin (A) is a polypropylene resin.

### Claim 41 (depends on 34)

The manufacturing method of the reflecting sheet according to claim 34, wherein the polyolefin resin (C) is a polypropylene resin.

### Claim 42 (depends on 34)

The manufacturing method of the reflecting sheet according to claim 34, wherein the polyolefin resin (A) is in an amount of from 30 percent to 80 percent by weight relative to the resin composition (a).

### Claim 43 (depends on 34)

The manufacturing method of the reflecting sheet according to claim 34, wherein a thickness of the surface layer portion of the sheet obtained in step (i) ranges from 10 μm to 400 μm, and a thickness of the inner layer portion ranges from 50 μm to 4000 μm.

### Claim 44 (depends on 34)

The manufacturing method of the reflecting sheet according to claim 34, wherein a thickness of the surface layer portion of the sheet obtained in step (i) ranges from 1% to 20% of the thickness of the sheet obtained in step (i).

### Claim 45 (depends on 34)

The manufacturing method of the reflecting sheet according to claim 34, wherein a stretch ratio in the two-way stretching is 1.5 time or more in each of the MD direction and the TD direction, and an area stretch ratio ranges from 3 times to 50 times.

### Claim 46 (depends on 34)

The manufacturing method of the reflecting sheet according to claim 34, further comprising the step of:
(iii) applying heat shrinkage of 10% or more in at least one of the longitudinal direction (MD) and the transverse direction (TD) to the sheet obtained in step (ii).

### Claim 47 (depends on 46)

The manufacturing method of the reflecting sheet according to claim 46, wherein heat shrinkage of 20% or more is applied to the sheet obtained in step (ii) in at least one direction of the sheet.

### Claim 48 (depends on 46, 47)

The manufacturing method of the reflecting sheet according to claim 46 or 47, wherein the two-way stretching is longitudinal-transverse successive two-way stretching, the relationship in stretch ratio between the longitudinal direction (MD) and the transverse direction (TD) is MD≦TD, and after performing transverse stretching, relaxation heat treatment is applied to the sheet to cause heat shrinkage of 10% or more in the transverse direction relative to the transverse stretch ratio at temperatures near a transverse stretching temperature.

### Claim 49 (depends on 48)

The manufacturing method of the reflecting sheet according to claim 48, wherein after performing the transverse stretching, relaxation heat treatment is applied to cause heat shrinkage of 20% or more in the transverse direction relative to the transverse stretch ratio at temperatures near the transverse stretching temperature.

### Claim 50 (depends on 34)

A reflecting sheet obtained by the manufacturing method according to claim 34.