KR20130043652A - Reflective material - Google Patents

Abstract

Provided are new reflectors with good reflectivity, particularly good light diffusivity.
At least one side of the resin layer (A) having voids therein is provided with a resin layer (B) containing two or more kinds of thermoplastic resins having different solubility parameters (SP values), and the resin layer (B) has a solubility parameter ( By a combination of thermoplastic resins having different SP values), the arithmetic mean roughness Sa of the three-dimensional surface roughness is set to 0.5 µm or more.

Description

Reflector {REFLECTIVE MATERIAL}

TECHNICAL FIELD This invention relates to the reflector which can be used suitably as a structural member, such as a liquid crystal display, a lighting fixture, or a lighting signboard.

Reflectors are used in many fields, such as liquid crystal displays, lighting equipment or lighting signs. In recent years, in the field of liquid crystal displays, device enlargement and display performance have been advanced, and it is required to supply a large amount of light to the liquid crystal to improve the performance of the backlight unit. Reflectiveness (also called simply "reflectiveness") has been required.

As a reflective material, the reflective film for liquid crystal displays using the white polyester film which uses aromatic polyester-based resin as a main raw material is known, for example (refer patent document 1).

However, when an aromatic polyester resin is used as the material of the reflecting material, since the aromatic ring contained in the molecular chain of the aromatic polyester resin absorbs ultraviolet rays, the film is exposed to ultraviolet rays generated from a light source such as a liquid crystal display device. There existed a problem that it deteriorated and yellowed and the light reflectivity of a reflective film falls.

Moreover, by extending | stretching the film formed by adding the filler to polypropylene resin, the micropore was formed in the film, and the reflecting material (refer patent document 2) which generate | occur | produced light scattering reflection, the base material layer containing an olefin resin and a filler; And olefin resin light reflectors having a laminated structure composed of layers containing olefin resins are also known (see Patent Document 3).

The reflective film using such an olefinic resin has the feature that there is little problem of film deterioration and yellowing by ultraviolet-ray.

Moreover, it is a reflecting sheet which consists of a resin composition which does not contain an inorganic powder in large quantity, The biaxially-stretched reflection by which the thermal contraction rate was reduced which contains polypropylene resin and at least 1 sort (s) or more of this polypropylene resin and incompatible resin. A sheet is known (refer patent document 4).

This reflective sheet is characterized by exhibiting a higher reflectance compared to a conventional reflective sheet having a basis weight and a density, even if it does not contain a large amount of inorganic powder.

In addition, since the surface of the above-mentioned reflective sheet is relatively smooth and has strong specular reflection property, when the light source is inserted into a liquid crystal display and the light source is turned on, there is a case where a problem arises in which the brightness of the screen is uneven (so-called brightness unevenness). Then, in order to solve the problem of the brightness nonuniformity of this screen, the reflective sheet which provided high light-diffusion property by coating organic fine particles etc. on the surface and forming unevenness is proposed (refer patent document 5).

Japanese Patent Application Laid-Open No. 04-239540 Japanese Patent Application Laid-Open No. 11-174213 Japanese Laid-Open Patent Publication 2005-031653 Japanese Unexamined Patent Publication No. 2008-158134 Japanese Unexamined Patent Publication No. 2010-085843

As mentioned above, although various reflectors have been proposed so far, there is still a need for reflectors with improved reflectivity in order to obtain a backlight having high brightness.

Moreover, as mentioned above, the reflecting material using an olefin resin has little problem of the film deterioration and yellowing by ultraviolet-ray, and its usefulness is high. However, since heat resistance is not enough, when using it as a structural member of the liquid crystal display which requires heat resistance, there existed a problem that a film shrink | contracted by heat, or a wave wrinkle generate | occur | produces.

BACKGROUND ART In recent years, light sources with high temperature heat generation, such as LEDs, have been used in fields such as liquid crystal displays, lighting fixtures, lighting signs, and the like, and better heat resistance is required for reflective materials.

On the other hand, a reflector subjected to bending and the like may be used by being inserted into a liquid crystal display device, and such bending workability (hereinafter referred to as "bending resistance") is also required for the reflecting material.

It is therefore an object of the present invention to provide a novel reflector which has excellent reflectivity, in particular good light diffusivity, and furthermore, which is also excellent in heat resistance and bending resistance and does not generate wave wrinkles even under a high temperature environment.

MEANS TO SOLVE THE PROBLEM This inventor uses the resin layer (B) which contains the amorphous resin whose glass transition temperature (JIS K 7121) is 85-150 degreeC in the at least single side | surface of the resin layer (A) containing a fine powder filler. By forming the formed laminated constitution, a new reflector having excellent reflectivity, excellent heat resistance and bending resistance, and not shrinking even under a high temperature environment was found.

The present inventors also conducted further studies on the resin layer (B) containing the amorphous resin and incompatible resins. As a result, the present inventors found the following findings and completed the present invention.

(1) The resin layer (B) in which the above two kinds of resins are blended has a characteristic surface state in which the arithmetic mean roughness (Sa) in the three-dimensional surface roughness is 0.5 µm or more, and the effect of high light diffusivity. I found out that.

(2) Moreover, it turned out that solubility parameter (SP value) of 2 types of resin mixed is originated in such a surface state.

That is, this invention is provided with the resin layer (B) which contains the 2 or more types of thermoplastic resin from which a solubility parameter (SP value) differs in at least one surface of the resin layer (A) which has a space | gap inside, and is a resin layer (B) Proposes a reflector characterized in that the arithmetic mean roughness Sa of the three-dimensional surface roughness is 0.5 µm or more by a combination of thermoplastic resins having different solubility parameters (SP values).

The reflector proposed by this invention is equipped with the resin layer (B) containing the 2 or more types of thermoplastic resin from which a solubility parameter (SP value) differs in at least one surface of the resin layer (A) which has a space | gap inside, and a resin layer ( B) has a good light diffusibility because the arithmetic mean roughness Sa of the three-dimensional surface roughness is 0.5 µm or more by a combination of thermoplastic resins having different solubility parameters (SP values), and thus is inserted into the backlight. In the case of using it, high brightness can be obtained.

Moreover, by using amorphous resin whose glass transition temperature (JIS K 7121) is 85-150 degreeC as one of resin which comprises a resin layer (B), it becomes possible to ensure heat resistance with bending resistance, and high temperature environment It was possible to prevent the occurrence of wavy wrinkles even under the Therefore, the reflector of this invention can be used suitably as a reflector, such as a liquid crystal display, a lighting fixture, or a lighting signboard.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure for demonstrating the wavy wrinkle evaluation method performed in the Example.

EMBODIMENT OF THE INVENTION Hereinafter, the reflector (it calls "this reflector") as an example of embodiment of this invention is demonstrated. However, this invention is not limited to this this reflector.

<This reflector>

This reflector is a reflector of a laminated structure provided with at least one surface of the resin layer (A) which has a space | gap inside, and a resin layer (B) containing thermoplastic resin (I) and incompatible thermoplastic resin (II) in this. This resin layer (B) has the characteristic that the arithmetic mean roughness Sa of a three-dimensional surface roughness is 0.5 micrometer or more.

<Resin layer (A)>

The resin layer (A) is a layer having voids therein. The resin layer (A) is a layer capable of improving the bend resistance of the present reflector while providing reflectivity to the present reflector.

(Porosity of Resin Layer A)

It is preferable that the resin layer (A) is a layer which has a space | gap inside, and the porosity, ie, the volume ratio which a space occupies in this layer, is 10 to 90% from a viewpoint of ensuring reflectivity. By forming the voids in such a range, since the whitening of the reflector proceeds sufficiently, high reflectivity can be attained, and the mechanical strength of the reflector is lowered and there is no breakage.

From such a viewpoint, the porosity of the resin layer (A) is particularly preferably in the range of 20% or more or 80% or less, especially 25% or more or 75% or less, particularly 30% or more or 70% or less. .

As a method of forming a space | gap in a resin layer (A), a chemical foaming method, a physical foaming method, a supercritical foaming method, an extending | stretching method, an extraction method, etc. are mentioned, for example. Among these, in this reflector, the extending | stretching method is preferable from a viewpoint of film forming property, continuous productivity, stable productivity, etc.

As a specific example of an extending | stretching method, the roll extending | stretching method, the rolling method, the tenter extending | stretching method, etc. are mentioned, for example. Among them, in the present invention, since the roll stretching method and / or the tenter stretching method have a wide selection of stretching conditions, a method of stretching them alone or in combination in at least one direction is preferably used.

The stretching is performed by the uniaxial stretching method stretching in the longitudinal direction (MD) by the roll stretching method or the like, the sequential biaxial stretching method stretching in the horizontal direction (TD) by the tenter stretching method or the like after the uniaxial stretching in the longitudinal direction, or the like. The simultaneous biaxial stretching method which draws simultaneously in a longitudinal direction and a horizontal direction using a tenter stretching method is mentioned.

Moreover, it is preferable to biaxially stretch from a viewpoint of improving reflectivity.

(Base resin)

Examples of the resin (base resin) constituting the main component of the resin layer (A) include an olefin resin, a polyester resin, an acrylic resin, a polyvinyl chloride resin, a polyvinylidene chloride resin, Resins, polyamide resins, polyurethane resins, and diene resins. Especially, an olefin resin is preferable from a viewpoint of improving reflectivity.

As an olefin resin, For example, polypropylene resins, such as a polypropylene and a propylene ethylene copolymer, polyethylene resins, such as polyethylene, a high density polyethylene, and a low density polyethylene, and cycloolefins, such as an ethylene-cyclic olefin copolymer, At least 1 sort (s) of polyolefin resin chosen from resin (including cycloolefin resin mentioned above), olefin elastomer, such as ethylene propylene rubber (EPR) and ethylene propylene diene terpolymer (EPDM), is mentioned. . Among these, polypropylene resin (PP) and polyethylene resin (PE) are preferable from mechanical properties, flexibility, and the like, and among them, among them, in particular, it has a higher melting point, better heat resistance than PE, and high mechanical properties such as elastic modulus. From a viewpoint, polypropylene resin (PP) is preferable.

Moreover, the polypropylene resin (PP) whose MFR (230 degreeC 21.18 N) is 0.1-20, especially 0.2-10, especially 0.5-5 is especially preferable among polypropylene resin (PP) from a viewpoint of extrusion moldability. .

Moreover, it is preferable that the base resin contained in a resin layer (A) is 30 mass% or more with respect to the mass of the whole resin layer (A), More preferably, it is 40 mass% or more, Especially preferably, it is 50 mass% or more (100% is included).

(Pulverized Filler)

It is preferable that a resin layer (A) contains fine powder filler in order to acquire the outstanding reflectivity. By containing fine powder filler, in addition to the refractive scattering caused by the refractive index difference between the base resin and the fine powder filler, the refractive scattering caused by the refractive index difference between the cavity formed around the fine powder filler, and further, the cavity and the fine powder filler formed around the fine powder filler Reflectivity can also be obtained from refractive scattering due to the difference in refractive index.

Examples of the finely divided fillers include inorganic fine powders and organic fine powders.

As inorganic fine powder, calcium carbonate, magnesium carbonate, barium carbonate, magnesium sulfate, barium sulfate, calcium sulfate, zinc oxide, magnesium oxide, calcium oxide, titanium oxide, alumina, aluminum hydroxide, hydroxyapatite, silica, mica, talc, Kaolin, clay, glass powder, asbestos powder, zeolite, siliceous silica, and the like. These can be used 1 type or in mixture of 2 or more types. Among these, considering the difference in refractive index with the resin constituting the sheet, it is preferable that the refractive index is large, and it is particularly preferable to use calcium carbonate, barium sulfate, titanium oxide or zinc oxide having a refractive index of 1.6 or more.

In addition, since titanium oxide has a significantly higher refractive index than other inorganic fillers and can significantly increase the refractive index difference with the base resin, excellent reflectivity can be obtained with a smaller compounding amount than with other fillers. Moreover, by using titanium oxide, even if the thickness of a reflector is made thin, high reflectivity can be obtained.

Therefore, it is more preferable to use a filler containing at least titanium oxide, and in this case, the amount of titanium oxide is 30% or more of the total mass of the inorganic filler, or when the organic filler and the inorganic filler are used in combination, It is preferable to set it as 30% or more.

Moreover, in order to improve the dispersibility of inorganic fine powder with respect to resin, you may use what surface-treated with the silicone type compound, a polyhydric alcohol type compound, an amine compound, a fatty acid, fatty acid ester, etc. on the surface of a fine powder filler.

On the other hand, as an organic fine powder, polymer beads, a polymer hollow particle, etc. are mentioned, These can be used 1 type or in mixture of 2 or more types.

Moreover, you may use combining an inorganic fine powder and an organic fine powder.

The finely divided filler preferably has a particle size of 0.05 µm or more and 15 µm or less, and more preferably 0.1 µm or more and 10 µm or less. Since the dispersibility to a base resin will not fall that the particle size of a filler is 0.05 micrometer or more, a homogeneous sheet is obtained. Moreover, when particle diameter is 15 micrometers or less, the interface of a base resin and a fine powder filler is formed densely, and a highly reflective reflector is obtained.

Moreover, as content of a fine powder filler, when reflecting property of a reflecting material, mechanical strength, productivity, etc. are considered, it is preferable that it is 10-80 mass% with respect to the mass of the whole resin layer (A), and it is 20-70 mass% More preferred. When content of a fine powder filler is 20 mass% or more, the area of the interface of a base resin and a fine powder filler can fully be secured, and high reflective property can be provided to a reflecting material. If content of a fine powder filler is 70 mass% or less, the mechanical strength required for a reflector can be ensured.

In the resin layer (A), as the content ratio of the base resin and the fine powder filler, from the viewpoint of light reflectivity, mechanical strength, productivity, and the like, the base resin: fine powder filler = 80: 20 to 30: 70, especially 80: It is preferable to set it as 20-60: 40.

(Other ingredients)

The resin layer (A) may contain other resins other than those mentioned above. Moreover, you may contain antioxidant, a light stabilizer, a heat stabilizer, a dispersing agent, a ultraviolet absorber, a fluorescent brightener, a compatibilizer, a lubricating agent, and other additives.

(Form of Resin Layer A)

The resin layer (A) may be a layer made of a sheet body, or may be a layer formed by forming a thin film (without forming a sheet) of the molten resin composition by extrusion or coating or the like.

When it consists of a sheet body, the sheet body may be an unstretched film or a uniaxial or biaxially stretched film, but it is preferable that it is a stretched film obtained by extending | stretching 1.1 times or more in at least one axial direction, especially a biaxially stretched film.

<Resin layer (B)>

The resin layer (B) is a layer containing thermoplastic resin (I) and incompatible thermoplastic resin (II).

The resin layer (B) contains the thermoplastic resin (I) and an incompatible thermoplastic resin (II), and the arithmetic mean roughness Sa in the three-dimensional surface roughness may be 0.5 µm or more. As long as it becomes arithmetic mean roughness Sa, the said thermoplastic resin (I) and the thermoplastic resin (II) incompatible with this can be used without a restriction | limiting.

(Surface roughness)

It is important that the surface of the resin layer (B) has an arithmetic mean roughness Sa of three-dimensional surface roughness of 0.5 µm or more. In terms of eliminating luminance non-uniformity of the screen, the arithmetic mean roughness Sa is preferably 0.5 µm or more and 7.0 µm or less, more preferably 1.0 µm or more and 3.0 µm or less.

As a method for forming such a resin layer (B), what is necessary is just to pay attention to the solubility parameter (it is described with "SP value" hereafter) of the 2 types of resin mixed, for example, and to mix more specifically What is necessary is just to select the combination whose difference of the absolute value of SP value of resin is 0.3-3.0 (cal / cm <3>) ^0.5 , More preferably, 0.5-1.5 (cal / cm <3>) ^0.5 .

By adjusting to such a range, the dispersibility of two types of resin is adjusted suitably, the arithmetic mean roughness Sa in the three-dimensional surface roughness of the resin layer (B) formed becomes said range, and high light diffusion Can demonstrate sex. If the difference between the absolute values of the SP values of the resins to be mixed is 0.5 (cal / cm 3) ^0.5 or more, an incompatible dispersed phase of the thermoplastic resin (II) is formed in the resin layer (B), and the surface of the resin layer (B) becomes coarse. Since high light diffusivity is obtained, it is preferable.

On the other hand, when the difference of the absolute value of the SP value of resin mixed is 3.0 (cal / cm <3>) ^0.5 or less, the insoluble phase of the thermoplastic resin (II) incompatible in the resin layer (B) is formed stably, and the resin layer (B) Since film forming property is also stable, it is preferable. Moreover, when the difference of the absolute value of SP value is too big | large, a phase separation may occur, for example, a thermoplastic resin (II) may isolate | separate and detach from a molten resin composition, and may cause adhesion | attachment (glows) etc. around a T die collar. .

More specifically, SP value of the thermoplastic resin (Ⅰ) of one of the 5.0 ~ 15.0 (cal / ㎤) 0. 5 which is preferred, inter alia 7.0 (cal / ㎤) ^0.5 or more than 12.0 (cal / ㎤) ^0.5 It is more preferable that it is the following.

In addition, SP values of the other thermoplastic resin (Ⅱ) of is more preferably 5.3 ~ 14.7 (cal / ㎤) 0. 5 is preferred and is, inter alia 7.3 (cal / ㎤) ^0.5 or more than 11.7 (cal / ㎤) ^0.5 or less desirable.

From this technical idea, the thermoplastic resin (I) whose SP value is in the said range is screened as candidate resin 1, Furthermore, the thermoplastic resin (II) which is incompatible with the thermoplastic resin (I) whose SP value is in the said range is selected. The resin layer (B) is selected by screening as the candidate resin 2 and selecting the one in which the arithmetic mean roughness Sa in the three-dimensional surface roughness is 0.5 or more among the resin layers formed by the combination of these candidate resins 1 and 2. ) Can be formed.

The SP value can be obtained by substituting the evaporation energy (Δei) and the molar volume (Δvi) of atoms and atomic groups constituting thermoplastic resin (I) or incompatible thermoplastic resin (II) by the following Fedors equation.

SP value (cal / cm 3) ^0.5 = (ΣΔei / Δvi) ^0.5

Here, the constants proposed by Fedors were used for Δei and Δvi (see Table 1).

Table 1 is an excerpt of the evaporation energy and molar volume of atoms and groups by Fedors.

In addition, in the resin layer (B), the thermoplastic resin (I) and the thermoplastic resin (II) which are incompatible with this may each be one kind of resin or two or more kinds of resins. For example, one type of thermoplastic resin (I-1) and two types of incompatible thermoplastic resins (II-1) (II-2) may be contained. In addition to the thermoplastic resin (I-1) and the incompatible thermoplastic resin (II-1), in addition to the thermoplastic resin (I-2) and incompatible thermoplastic resin (II-2) 2 Combinations of more than one kind may be contained.

However, from the viewpoint of the effect of making the arithmetic mean roughness Sa of the surface of the resin layer (B) 0.5 m or more, the thermoplastic resin (I) and the incompatible thermoplastic resin (II) are differently expressed, 70 mass% or more, especially 80 mass% or more, especially 90 mass% or more of the total amount of resin which the amount of resin contained in the combination whose absolute value becomes 0.3-3.0 (cal / cm <3>) ^0.5 comprises a resin layer (B) It is desirable to occupy.

In addition, the content rate of thermoplastic resin (I) and thermoplastic resin (II) incompatible with this is 60: 40-90: 10, or 40: 60-10: 10, especially 70: 30-80: It is preferable that it is 20 or 30: 70-20: 80 from the point of the effect of stably forming a dispersed phase and roughening the surface of a resin layer (B).

However, even if any of thermoplastic resin (I) and thermoplastic resin (II) increases, since it is a difference of which becomes a mother phase or a dispersed phase, it is the same in terms of the effect of roughening the surface of resin layer (B).

(Additional characteristics)

Glass transition temperature (JIS K 7121, Tg) is 85-150 as 1 type of resin which comprises a resin layer (B), Preferably 1 type of base resin, for example, thermoplastic resin (I) or (II). Heat resistance can also be provided to this reflecting material by using amorphous resin which is ° C.

In addition, the base resin of a resin layer (B) is 20 mass% or more with respect to the mass of the whole resin layer (B), More preferably, it is 30 mass% or more, Especially preferably, it means the resin which occupies 50 mass% or more. to be.

The amorphous resin herein refers to a resin having a very low degree of crystallinity in which the exothermic peak accompanying crystallization is not observed or the amount of crystal melting heat becomes 10 J / g or less even if observed.

Even if the environmental temperature changes, the amorphous resin exhibits stable characteristics below the glass transition point, and can exhibit high heat resistance to the reflecting material due to the property that the shrinkage rate is small and the dimensional stability is excellent up to the temperature near the glass transition point.

Therefore, when the glass transition temperature (Tg) of the base resin of the resin layer (B), for example, thermoplastic resin (I) is 85-150 degreeC, even if it uses as a structural member, such as a liquid crystal display, heat resistance is enough and it is preferable. .

From such a viewpoint, it is more preferable that the glass transition temperature (Tg) of the base resin of the resin layer (B) is 90 degreeC or more and 150 degrees C or less, and it is still more preferable that it is 100 degreeC or more and 150 degrees C or less especially.

As this kind of amorphous resin, cycloolefin resin, polystyrene, polycarbonate, acrylic resin, amorphous polyester resin, polyetherimide, thermoplastic polyimide, etc. are mentioned, for example. Especially, when considering elongation, the range of glass transition temperature, and transparency, cycloolefin resin, polystyrene, and polycarbonate resin are preferable, and cycloolefin resin is especially preferable.

Here, the cycloolefin resin of the resin layer (B) may be either a cycloolefin homopolymer or a cycloolefin copolymer.

A cycloolefin resin is a high molecular compound whose main chain consists of a carbon-carbon bond and has a cyclic hydrocarbon structure in at least one part of a main chain. This cyclic hydrocarbon structure is introduce | transduced by using as a monomer the compound (cycloolefin) which has at least 1 olefinic double bond in a cyclic hydrocarbon structure like typified by norbornene and tetracyclo dodecene.

Cycloolefin-type resins are classified into the addition (co) polymer of cycloolefin or its hydrogenated substance, the addition copolymer of cycloolefin and the alpha-olefin, or its hydrogenated substance, the ring-opening (co) polymer of cycloolefin, or its hydrogenated substance, all It can be used for this reflector.

As a specific example of cycloolefin resin, Cyclopentene, cyclohexene, cyclooctene; Monocyclic cycloolefins such as cyclopentadiene and 1,3-cyclohexadiene; Bicyclo [2.2.1] hepta-2-ene (common name: norbornene), 5-methylbicyclo [2.2.1] hepta-2-ene, 5,5-dimethyl-bicyclo [2.2.1] hepta 2-ene, 5-ethyl-bicyclo [2.2.1] hepta-2-ene, 5-butyl-bicyclo [2.2.1] hepta-2-ene, 5-ethylidene-bicyclo [2.2.1 ] Hepta-2-ene, 5-hexyl-bicyclo [2.2.1] hepta-2-ene, 5-octyl-bicyclo [2.2.1] hepta-2-ene, 5-octadecyl-bicyclo [2.2 .1] hepta-2-ene, 5-methylidene-bicyclo [2.2.1] hepta-2-ene, 5-vinyl-bicyclo [2.2.1] hepta-2-ene, 5-propenyl-ratio Bicyclic cycloolefins such as cyclo [2.2.1] hepta-2-ene;

Tricyclo [4.3.0.12,5] deca-3,7-diene (common name: dicyclopentadiene), tricyclo [4.3.0.12,5] deca-3-ene; Tricyclo [4.4.0.12,5] undec-3,7-diene or tricyclo [4.4.0.12,5] undec-3,8-diene or partial hydrogen adducts thereof (or of cyclopentadiene and cyclohexene Adduct) Phosphorus tricyclo [4.4.0.12,5] undec-3-ene; 5-cyclopentyl-bicyclo [2.2.1] hepta-2-ene, 5-cyclohexylbicyclo [2.2.1] hepta-2-ene, 5-cyclohexenylbicyclo [2.2.1] hepta-2 Tricyclic cycloolefins such as -ene, 5-phenyl-bicyclo [2.2.1] hepta-2-ene;

Tetracyclo [4.4.0.12,5.17,10] dodeca-3-ene (simply referred to as tetracyclododecene), 8-methyltetracyclo [4.4.0.12,5.17,10] dodeca-3-ene, 8- Ethyltetracyclo [4.4.0.12,5.17,10] dodeca-3-ene, 8-methylidenetetracyclo [4.4.0.12,5.17,10] dodeca-3-ene, 8-ethylidenetetracyclo [4.4. 0.12,5.17,10] dodeca-3-ene, 8-vinyltetracyclo [4,4.0.12,5.17,10] dodeca-3-ene, 8-propenyl-tetracyclo [4.4.0.12,5.17, 10] 4-ring cycloolefin like dodeca-3-ene;

8-cyclopentyl-tetracyclo [4.4.0.12,5.17,10] dodeca-3-ene, 8-cyclohexyl-tetracyclo [4.4.0.12,5.17,10] dodeca-3-ene, 8-cyclohex Cenyl-tetracyclo [4.4.0.12,5.17,10] dodeca-3-ene, 8-phenyl-cyclopentyl-tetracyclo [4.4.0.12,5.17,10] dodeca-3-ene; Tetracyclo [7.4.13,6.01,9.02,7] tetradeca-4,9,11,13-tetraene (also called 1,4-methano-1,4,4a, 9a-tetrahydrofluorene), Tetracyclo [8.4.14,7.01,10.03,8] pentadeca-5,10,12,14-tetraene (also called 1,4-methano1,4,4a, 5,10,10a-hexahydroanthracene) ); Pentacyclo [6.6.1.13,6.02,7.09,14] -4-hexadecene, pentacyclo [6.5.1.13,6.02,7.09,13] -4-pentadecene, pentacyclo [7.4.0.02,7.13,6.110,13 ] -4-pentadecene; Heptacyclo [8.7.0.12,9.14,7.111,17.03,8.012,16] -5-eicosene, heptacyclo [8.7.0.12,9.03,8.14,7.012,17.113,16] -14-eicosene; And polycyclic cycloolefins such as tetramers of cyclopentadiene.

These cycloolefins can be used individually or in combination of 2 or more types, respectively.

Specific examples of the α-olefin copolymerizable with cycloolefin include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl- 1-pentene, 4-methyl-1-pentene, 4-methyl1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl C2-C20, Preferably it is C2-C8, such as 1-hexene, 1-octene, 1-decene, 1 dodecene, 1- tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, etc. And ethylene or α-olefin.

These alpha -olefins can be used individually or in combination of 2 types or more, respectively.

There is no restriction | limiting in particular in the polymerization method of cycloolefin or a cycloolefin, and an alpha olefin, and the hydrogenation method of the obtained polymer, It can carry out according to a well-known method.

Among the above cycloolefin-based resins, from the viewpoint of heat resistance, the glass transition temperature (Tg) is preferably 70 to 170 ° C, particularly 80 ° C or more and 160 ° C or less, and particularly preferably 85 ° C or more and 150 ° C or less cycloolefin resin. .

Under the present circumstances, you may mix and mix two or more types of cycloolefin resin, and may adjust the glass transition temperature (Tg) of mixed resin to the said range.

A commercial product can be used as cycloolefin resin. For example, "Zenooa (registered trademark)" manufactured by Nippon Xeon Co., Ltd. (chemical name; hydrogenated product of a ring-opening polymer of a cyclic olefin), "Apel (registered trademark)" manufactured by Mitsui Chemical Co., Ltd. (ethylene and tetracyclododecene Addition copolymer) and "TOPAS (registered trademark)" (addition copolymer of ethylene and norbornene) manufactured by Polyplastics. Among these, Nippon Xeon Co., Ltd. "Zenooa (registered trademark)" (chemical name; hydrogenated substance of the ring-opening polymer of a cyclic olefin) and / or "TOPAS (registered trademark)" by Polyplastics company (ethylene and norbor) The addition copolymer of Nene is especially preferable because a reflector having a high reflection performance is obtained.

Moreover, when using the copolymer of olefin and norbornene as a cycloolefin, it is preferable that content of norbornene is 60-90 wt%, It is especially preferable that it is 65 wt% or more and 80 wt% or less.

It is preferable that said amorphous resin (when a 2 or more component contains amorphous resin, these total amounts) is 50 mass% or more with respect to the mass of the whole resin layer (B), More preferably, it is 70 mass% Above, Especially preferably, it is 90 mass% or more (100% is excluded).

As mentioned above, when using amorphous resin whose glass transition temperature is 85-150 degreeC as a base resin of a resin layer (B), for example, thermoplastic resin (I), if it adds the viewpoint which raises bending resistance, As resin, it is preferable to contain an olefin resin, a thermoplastic elastomer, etc. as thermoplastic resin (II), for example.

For example, by blending olefin resins other than cycloolefin resins and / or thermoplastic elastomers with cycloolefin resins to form a resin layer (B), the bending resistance which cannot be obtained alone with cycloolefin resins alone, The heat resistance which could not be obtained by the system resin alone can be ensured together.

At this time, it is preferable that the melt flow rate (referred to as "MFR") of olefin resin other than cycloolefin resin and / or a thermoplastic elastomer is 0.1 or more or 20 or less (JIS K 7210, 230 degreeC, load 21.18 N). It is more preferable that it is especially 0.5 or more or 10 or less.

Moreover, it is preferable to also adjust MFR of cycloolefin resin to the said range. When the MFR of both is adjusted in this way, olefin resins and / or thermoplastic elastomers other than cycloolefin resins are oriented in the cycloolefin resins, and therefore, there is no fear of deteriorating the mechanical properties as a reflector extremely. Do.

Examples of the olefin resins other than the cycloolefin resins include polypropylene resins such as polypropylene and propylene-ethylene copolymers, and polyethylene resins such as polyethylene, high density polyethylene, and low density polyethylene. 1 type or 2 or more types of these can be used in combination. Among them, polyethylene resin (PE) and polypropylene resin (PP) are preferred, and among them, in particular, from the viewpoint of higher melting point and better heat resistance than polyethylene resin (PE), and mechanical properties such as elastic modulus are high, Polypropylene resin (PP) is preferred.

Moreover, the polypropylene resin (PP) whose MFR (230 degreeC 21.18 N) is 0.1-20, especially 0.2-10, especially 0.5-5 is especially preferable among polypropylene resin (PP) from a viewpoint of extrusion moldability. .

Moreover, it is preferable to contain the olefin resin containing the same monomeric unit as the olefin resin of a resin layer (A) from a viewpoint of improving the adhesiveness between resin layers (A) (B).

On the other hand, examples of the thermoplastic elastomer include olefin elastomers, styrene elastomers, urethane elastomers, polyester elastomers, and the like, and one or two or more of these may be used in combination. Especially, since a styrene-type elastomer is compatible with an olefin resin, especially a polypropylene resin, it is preferable from a viewpoint of improving the adhesiveness of a resin layer (A) and a resin layer (B).

As a styrene-type elastomer, the copolymer of styrene and conjugated dienes, such as butadiene or isoprene, and / or its hydrogenated substance etc. are mentioned, for example. Styrene-based elastomers are block copolymers having styrene as a hard segment and a conjugated diene as a soft segment, and are preferable because the vulcanization step is unnecessary. In addition, hydrogenation is more preferable because of high thermal stability.

Preferred examples of styrene-based elastomers include, for example, styrene-butadiene-styrene block copolymers, styrene-isoprene-styrene block copolymers, styrene-ethylene-butylene-styrene block copolymers, styrene-ethylene-propylene-styrene block airborne Coalescence is mentioned.

Among them, styrene-ethylene-butylene-styrene block copolymers and styrene-ethylene-propylene-styrene block copolymers (also referred to as hydrogenated styrene-based elastomers), in which double bonds of the conjugated diene component are removed by hydrogenation, desirable.

(Pulverized Filler)

The resin layer (B) may contain finely divided filler as long as the arithmetic mean roughness Sa of the three-dimensional surface roughness is 0.5 µm or more. The type, particle size, and surface treatment method of the fine powder filler are the same as those described in the resin layer (A), and preferred examples are also the same.

(Other ingredients)

The resin layer (B) may contain an antioxidant, a light stabilizer, a heat stabilizer, an ultraviolet absorber, a fluorescent brightener, a lubricant, and other additives.

In addition, since mixing the compatibilizer, the dispersant, the diffusion beads, and the like makes it difficult to adjust the arithmetic mean roughness (Sa) of the three-dimensional surface roughness to a desired range, these are basically not mixed in the resin layer (B). You may mix | blend on the back.

(Form of Resin Layer B)

The resin layer (B) may be a layer made of a sheet body, or may be a layer formed by forming a thin film (without forming a sheet) of the molten resin composition by extrusion or coating or the like.

When it consists of a sheet body, the sheet body may be an unstretched film or a uniaxial or biaxially stretched film, but it is preferable that it is a stretched film obtained by extending | stretching 1.1 times or more in at least one axial direction, especially a biaxially stretched film.

<Lamination structure>

This reflector needs to have a laminated structure in which the resin layer (A) and the resin layer (B) were formed. By setting it as such a structure, processability, such as bending resistance, can be maintained, providing a reflectance to the resin layer (A), and high light diffusivity can be provided to a resin layer (B).

Thus, this reflector can exhibit a synergistic effect by interaction of resin layer (A) and (B), and can exhibit very excellent reflectivity.

In addition, by selecting the resin of the resin layer (B), there is an advantage that heat resistance can be imparted, heat resistance and workability can be imparted while exhibiting higher reflectivity. Therefore, in such a laminated structure, it is preferable that the resin layer (B) is located in the outermost layer of the side to which light is irradiated (the reflection use surface side). By setting it as such a structure, high reflectivity can be provided to a reflector.

Moreover, as another laminated structure, the laminated structure of three layers which provided the resin layer (B) on both surfaces of the resin layer (A) is mentioned, for example. Moreover, you may provide other layers other than a resin layer (A) and a resin layer (B), and the other layer may be interposed between each layer of a resin layer (A) and a resin layer (B). For example, an adhesive layer may be interposed between the resin layer (A) and the resin layer (B).

<Thickness>

The thickness of the reflector is not particularly limited, and is preferably, for example, 30 µm to 1500 µm, and particularly preferably 50 µm to 1000 µm in view of handling properties in practical use.

For example, it is preferable that thickness is 50 micrometers-700 micrometers as a reflector for liquid crystal display uses, For example, it is preferable that thickness is 100 micrometers-1000 micrometers as a reflector for lighting fixtures and lighting signboard use. .

As can be seen from the results of the examples described later, even if the resin layer (B) is thin, the heat resistance of the entire reflector can be improved, while if the resin layer (B) is too thick, the bend resistance is reduced. From such a viewpoint, each layer total thickness ratio of the resin layer (A) and resin layer (B) (for example, when there are two layers of resin layer (B), the ratio of the total thickness of two layers) is 3: 1-15 : 1 is preferable, and it is especially preferable that it is 3: 1-10: 1.

<Average reflectance>

This reflector can be made into 97% or more with respect to the light of wavelength 420nm-700nm at least on one side. If it has such reflectivity, favorable reflection characteristics will be exhibited as a reflecting material, and the liquid crystal display etc. which inserted this reflecting material can realize sufficient brightness of the screen.

<Porosity>

This reflector is provided with the layer which has a space | gap in the resin layer (A) in order to improve reflectivity, The porosity of the resin layer (A) makes the resin layer (A) the porosity at the time of forming a space | gap by extending | stretching. It can obtain | require by the following formula with respect to the film to make.

Porosity (%) = {(density of film before stretching-density of film after stretching) / density of film before stretching｝ × 100

<Resistance strength>

This reflector can be made into 1000 times or more of the breaking strength measured by the following test method.

The test method at this time was applied to a sample cut to a length of 10 cm and a width of 10 mm using an MIT anti-wear fatigue tester, under a condition of a reciprocating bending speed of 175 rpm and a swing angle of 135 °. To measure the number of bendings until cutting.

<Manufacturing Method>

It does not specifically limit as a manufacturing method of this reflector, A well-known method can be employ | adopted. Hereinafter, although an example is given and demonstrated about the manufacturing method of the reflective material provided with laminated structure, it is not limited to the following manufacturing method at all.

First, the resin composition A which mix | blended fine powder filler, other additives, etc. with an olefin resin etc. as needed is produced. Specifically, finely divided fillers and the like are added to the olefinic resin as a main component as necessary, mixed with a ribbon blender, tumbler, Henschel mixer, or the like, followed by Banbury mixer, single screw or twin screw extruder. Resin composition A can be obtained by knead | mixing at the temperature more than melting | fusing point (for example, 190 degreeC-270 degreeC). Or the resin composition A can be obtained by adding predetermined amount to olefin resin, fine powder filler, etc. by another feeder. Moreover, what is called a masterbatch which mix | blended fine powder filler, other additives, etc. with high concentration in advance to olefin resin can be made, and this masterbatch and olefin resin can be mixed and it can be set as resin composition A of desired density | concentration.

On the other hand, the resin composition B which mix | blended olefin resin and / or thermoplastic elastomer, and other additive as needed with amorphous resins, such as cycloolefin resin, is produced.

Specifically, olefin resin and / or thermoplastic elastomer, other antioxidants, etc. are added to cycloolefin resin as needed, and it mixes with a ribbon blender, a tumbler, a Henschel mixer, etc., and then Banban mixer, uniaxial or Resin composition B can be obtained by knead | mixing at the temperature (for example, 220 degreeC-280 degreeC) more than melting | fusing point of resin using a twin screw extruder etc. Or the resin composition B can be obtained by adding predetermined amount to cycloolefin resin, an olefin resin, and / or a thermoplastic elastomer etc. by a separate feeder etc. In addition, a so-called master batch in which high concentrations of olefin resins and / or thermoplastic elastomers and other antioxidants and the like are mixed in advance is made, and the master batch and cycloolefin resins, olefin resins and / or thermoplastic elastomers are mixed and desired. It can also be set as the resin composition B of concentration.

Next, after drying the resin compositions A and B obtained in this way, they are supplied to a separate extruder, respectively, and it heats and melts above predetermined temperature, respectively.

Although conditions, such as extrusion temperature, need to be set in consideration of the molecular weight falling by decomposition, etc., for example, the extrusion temperature of resin composition A is 190 degreeC-270 degreeC, and the extrusion temperature of resin composition B is 220 degreeC. It is preferable that it is -280 degreeC.

Thereafter, the molten resin composition A and the resin composition B are joined to a T die for two or three layers, extruded in a stacked form from a slit-shaped outlet of the T die, and solidified by tight contact with a cooling roll to form a cast sheet.

It is preferable that the obtained cast sheet is extended | stretched at least in 1 axial direction. By extending | stretching, the interface of olefin resin and fine powder filler in a resin layer (A) is peeled off, a space | gap is formed, whitening of a sheet advances, and the light reflectivity of a film can be improved. Moreover, it is especially preferable that the cast sheet is extended | stretched in the biaxial direction. Although the space | gap formed only by uniaxial stretching is only a fibrous form extended in one direction, the biaxial stretching extends the space | gap to longitudinal and bilateral directions, and becomes a disk shape.

That is, by biaxial stretching, the peeling area of the interface between the olefin resin and the fine powder filler in the resin layer (A) increases, and the whitening of the sheet proceeds further, and as a result, the light reflectivity of the film can be further improved. . Moreover, when biaxially stretching, the anisotropy in the shrinkage direction of the film decreases, so that the heat resistance of the film can be improved and the mechanical strength of the film can also be increased.

It is preferable that the extending | stretching temperature at the time of extending | stretching a cast sheet is the temperature within the range of more than glass transition temperature (Tg) and (Tg + 50 degreeC) of amorphous resin of the resin layer (B).

When extending | stretching temperature is more than glass transition temperature (Tg), it can carry out stably without breaking a film at the time of extending | stretching. Moreover, when extending | stretching temperature is the temperature below (Tg + 50 degreeC), extending | stretching orientation becomes high and as a result, since a porosity becomes large, a high reflective film is easy to be obtained.

The stretching order of biaxial stretching is not particularly limited, and for example, simultaneous biaxial stretching or sequential stretching may be used. After melt-molding using an extending | stretching installation, after extending | stretching in the take-up direction (MD) of a film by roll extending | stretching, you may extend | stretch in the orthogonal direction (TD) of MD by tenter extending | stretching, or by tubular stretching etc. You may perform biaxial stretching. It is preferable to extend | stretch 6 times or more as a draw ratio in the case of biaxial stretching. By extending | stretching an area magnification 6 times or more, the porosity of the whole reflective film comprised from a resin layer (A) and a resin layer (B) may implement | achieve 40% or more.

After extending | stretching, in order to provide dimensional stability (shape stability of a space | gap) to a reflective film, it is preferable to perform heat fixing. It is preferable that the process temperature for heat fixing a film is 110 degreeC-170 degreeC. The treatment time required for heat fixing is preferably 1 second to 3 minutes. Moreover, there is no restriction | limiting in particular about an extending | stretching installation etc. It is preferable to perform tenter extending | stretching which can perform a heat setting process after extending | stretching.

<Applications>

Although this reflector can also be used as a reflector as it is, it can also be used as a structure which laminated | stacked this reflector on a metal plate or a resin plate, and is useful as a reflecting plate used for liquid crystal display devices, such as a liquid crystal display, a lighting fixture, a lighting signboard, etc., for example. Do.

At this time, as a metal plate which laminates this reflector, an aluminum plate, a stainless plate, a galvanized steel plate, etc. are mentioned, for example.

As a method of laminating the present reflector on a metal plate or a resin plate, for example, a method of using an adhesive, a method of thermal fusion without using an adhesive, a method of bonding through an adhesive sheet, a method of extrusion coating, or the like Can be mentioned. However, it is not limited to these methods.

More specifically, adhesives, such as polyester type, polyurethane type, and epoxy type, are apply | coated to the surface of the side which bonds the reflecting material of a metal plate or a resin plate (together called a "metal plate etc."), Can be bonded.

In such a method, an adhesive is applied to a surface such as a metal plate to which the reflecting material is bonded by using a coating apparatus generally used such as a reverse roll coater and a kiss roll coater so that the thickness of the adhesive film after drying is about 2 to 4 µm. Apply.

Subsequently, a reflecting plate can be obtained by covering and cooling a reflector immediately using a roll laminator, drying and heating a coated surface with an infrared heater and a hot air heating furnace, and maintaining a surface, such as a metal plate, at predetermined temperature.

As a use of this reflector, it is useful as a reflection member used for liquid crystal display devices, such as a liquid crystal display, a lighting fixture, a lighting signboard, etc.

Generally, a liquid crystal display consists of a liquid crystal panel, a polarizing reflection sheet, a diffusion sheet, a light guide plate, a reflection sheet, a light source, a light source reflector, etc.

The reflector may be used as a reflector that serves to efficiently inject light from a light source into a liquid crystal panel or a light guide plate, and may be used as a light source reflector having a role of condensing irradiation light from a light source disposed at an edge portion and incident the light guide plate. It may be.

<Explanation of term>

In general, "film" refers to a thin, flat product having a very small thickness compared to its length and width, and having a maximum thickness arbitrarily defined, and usually supplied in the form of a roll (Japanese Industrial Standard JIS K 6900). "Sheet" is thin by definition in JIS, and generally refers to a product whose thickness is small and flat compared with length and width. However, since the boundary between a sheet and a film is not certain and it is not necessary to distinguish both in the dialect in this invention, even if it calls it "film" in this invention, it shall contain a "sheet", "" Film "shall also be included.

In addition, when expressed as a "main component" in this specification, the meaning which allows containing another component in the range which does not impair the function of the said main component is included unless it mentions specially. At this time, the content ratio of the main component is not specified, but the main component (when the two or more components are the main component, the total amount thereof) is 50% by mass or more, preferably 70% by mass or more, particularly preferably 90 in the composition. It occupies mass% or more (it contains 100%).

In the present invention, when expressed by "X to Y" (X and Y are arbitrary numbers), unless otherwise indicated, "preferably larger than X" and "preferably larger than X" and "preferably larger than X" and "preferably Preferably less than Y ”.

In addition, in this invention, when represented by "X or more" (X is arbitrary number), unless otherwise indicated, it contains the meaning of "preferably larger than X", and "Y or less" (Y is arbitrary Number), the term &quot; preferably less than Y &quot; unless otherwise indicated.

Example

Although an Example is shown to the following and this invention is demonstrated to it further more concretely, this invention is not limited to these, A various application is possible within the range which does not deviate from the technical idea of this invention.

<Measurement and Evaluation Method>

First, the measuring method and evaluation method of the various physical property values of the sample obtained by the Example and the comparative example are demonstrated. Hereinafter, MD is taken as the take-out (flow) direction of a film, and the orthogonal direction is shown as TD.

(Porosity)

The density of the film before stretching (denoted by "unstretched film density") and the density of the film after stretching (expressed by "stretched film density") were measured, and the porosity (%) of the film was obtained by substituting the following formula. .

Porosity (%) = {(Unstretched Film Density-Stretched Film Density) / Unstretched Film Density x 100

(Average reflectance)

The reflectance when the integrating sphere was attached to the spectrophotometer ("U-3900H", manufactured by Hitachi, Ltd.) and the alumina white plate was 100%, was measured at 0.5 nm intervals over a wavelength of 420 nm to 700 nm. Measured. The average value of the obtained measured value was calculated and this value was made into the average reflectance (%).

(Wavy wrinkle evaluation of the reflective material)

With respect to the SUS board which imitated the structure (refer FIG. 1) of the backlight unit of a 20-inch type | mold TV, a reflector (sample) was affixed so that there might be no gap between a SUS board and a reflecting material, and it put into 80 degreeC hot air oven. It took out after 3 hours and cooled to room temperature. Thereafter, the distance between the SUS plate and the reflecting material (how many millimeters was corrugated with respect to the SUS plate) was measured.

(Strength strength)

Using an MIT anti-wear fatigue tester, the samples produced in Examples and Comparative Examples were cut into a length of 10 cm and a width of 10 mm, loaded with a load of 9.8 N, and subjected to a reciprocating bending speed of 175 rpm and a swing angle of 135 °. Under the conditions, the number of times of bending up to cutting was measured.

(Arithmetic mean roughness (Sa) in three-dimensional surface roughness)

The surface (resin layer B) of the reflector (sample) was observed with the following apparatus and conditions, the obtained image was analyzed, and an arithmetic mean roughness (it describes as "Sa" hereafter) was computed. In addition, at the time of calculation, it based on JISB0601-2001.

Device: Electron beam three-dimensional illuminance analyzer "ERA-4000" (manufactured by Elionix)

Deposition conditions: 10 ㎃ × 100 sec, Pt-Pd deposition

Acceleration voltage: 10 kV

Observation magnification: 250 times

Analysis area: 360 (㎛) × 480 (㎛)

(Light diffusivity)

By the following apparatus and conditions, the reflected light intensity of the reflector (sample) was measured, and the intensity ratio of the specular reflection component and the diffuse reflection component was calculated by substituting the following equation.

Reflective component intensity ratio α = Σ (reflected light intensity from -5 degrees to 5 degrees) / Σ (reflected light intensity from 25 degrees to 35 degrees)

Reflective component intensity ratio β = Σ (reflected light intensity between 55 and 65 degrees) / Σ (reflected light intensity between 25 and 35 degrees)

Device: Automatic variable photometer `` GP-1R type '' (manufactured by Murakami Color Research Institute)

Light source: halogen lamp

Beam aperture diameter: 10.5 mm

Light receiving aperture diameter: 4.5 mm

Light incident direction: TD of film

Light incident angle: -30 degrees

Receiving measurement range of reflected light: -30 degrees to 90 degrees

Measuring interval: 1 degree

The light diffusivity was evaluated based on the following evaluation criteria for the reflection component intensity ratios α and β. However, the symbol "(circle)" and "(triangle | delta)" are more than a practical use level.

 = Evaluation criteria =

"(Circle)": both reflection component intensity ratios (alpha) and (beta) are 0.5 or more

"Δ": 0.5 or more of the reflection component intensity ratios α or β

"X": Both reflection component intensity ratios (alpha) and (beta) are less than 0.5

&Lt; Example 1 &gt;

(Preparation of the resin composition A of the resin layer (A))

Polypropylene resin (manufactured by Nippon Polypro Co., Ltd., trade name "Novatech PP FY6HA", density (JIS K 7112): 0.9 g / cm 3, MFR (230 ° C, 21.18 N, JIS K-7210): 2.4 g / 10 min) Pellets and titanium oxide (manufactured by KRONOS Corporation, trade name "KRONOS 2230", density 4.2 g / cm 3, rutile titanium oxide, Al, Si surface treatment, TiO ₂ content 96.0%, production method: chlorine method), 50: 50 After mixing at the mass ratio of, it pelletized using the twin screw extruder heated at 270 degreeC, and the resin composition A was produced.

(Preparation of the resin composition B of the resin layer (B))

Of amorphous cycloolefin-based resin A (manufactured by Nippon Xeon Co., Ltd., product name "ZEONOR 1430R", density (ASTMD792): 1.01 g / cm 3, glass transition temperature (Tg) (JIS K 7121): 133 ° C, SP value: 7.4 Pellets and amorphous cycloolefin resin B (manufactured by Nippon Xeon Co., Ltd., trade name "ZEONOR 1060R", Density (ASTMD792): 1.01 g / cm 3, MFR (230 ° C, 21.18 N, JIS K-7210): 14 g / 10 min, glass transition temperature (Tg) (JIS K 7121): 100 degreeC, SP value: 7.4) Pellets, polypropylene resin (made by Nippon Polypro Co., Ltd., brand name "Novatec PPEA9", density (JIS K 7112): Pellets of 0.9 g / cm 3 and MFR (230 ° C., 21.18 N, JIS K-7210): 0.5 g / 10 min, SP value: 8.0) were mixed at a mass ratio of 50:25:25, and then at 230 ° C. It pelletized using the heated twin screw extruder, and the resin composition B was produced.

(Production of reflective material)

The resin compositions A and B were fed to extruders A and B heated at 200 ° C. and 230 ° C., respectively, and melt-kneaded at 200 ° C. and 230 ° C. in each extruder, and then joined to T dies for two or three layers. It extruded in the sheet form so that it might become three-layered constitution of a resin layer (B) / resin layer (A) / resin layer (B), and it solidified by cooling and formed the laminated sheet.

After the obtained laminated sheet was stretched twice in MD at a temperature of 130 ° C., further biaxially stretched by three times tenter stretching in TD at 130 ° C. to give a thickness of 225 μm (resin layer (A): 185 μm, Resin layer (B): The reflector (sample) of 20 micrometers lamination ratio A: B = 4.6: 1 was obtained.

About the obtained reflector, the porosity, average reflectance, the corrugation of a reflector, and abrasion resistance were evaluated.

In addition, about the porosity, the resin layer (A) was evaluated. That is, the resin composition A was supplied to the extruder A, and according to the said operation, the single layer film (thickness 185 micrometers) of only the resin layer (A) was obtained, and it evaluated.

<Example 2>

In preparation of the resin composition B of Example 1, pellet of amorphous cycloolefin resin A (made by Nippon Xeon Co., Ltd., brand name "ZEONOR 1430R", SP value: 7.4), polypropylene resin (made by Nippon Polypro Co., Ltd., brand name) In the preparation of the reflector of Example 1, the pellet of "Novatec PPEA9" and SP value: 8.0) was mixed in the mass ratio of 75:25, and the obtained laminated sheet was doubled by MD at the temperature of 138 degreeC. 228 micrometers thick (resin layer (A): 190 micrometers), and a resin layer (B) similarly to Example 1 except the roll extending | stretching and carrying out biaxial stretching by 3 times tenter stretching by TD at 138 degreeC. ): A reflector (sample) having a 19 µm lamination ratio A: B = 5: 1) was obtained. Evaluation similar to Example 1 was performed about the obtained reflector.

<Example 3>

(Preparation of the resin composition A of the resin layer (A))

Polypropylene resin (manufactured by Nippon Polypro Co., Ltd., trade name "Novatech PP FY6HA", density (JIS K 7112): 0.9 g / cm 3, MFR (230 ° C, 21.18 N, JIS K-7210): 2.4 g / 10 min, SP value: 8.0), pellets, and titanium (KRONOS Inc. oxide producing a trade name "KRONOS 2230", density 4.2 g / ㎤, rutile titanium, Al, Si surface oxidation treatment, 96.0% TiO ₂ content, the recipe: chlorine method) After mixing in the mass ratio of 50:50, it pelletized using the twin screw extruder heated at 270 degreeC, and the resin composition A was produced.

(Preparation of the resin composition B of the resin layer (B))

Amorphous cycloolefin-based resin C (manufactured by Nippon Xeon Co., Ltd., product name "Zenoa RCY50", hydrogenated product of ring-opening polymer of cyclic olefin, density (ISO 1183): 1.01 g / cm 3, MFR (230 ° C., 21.18 N, JIS K 7210: 1.2 g / 10 min, Pellets of glass transition temperature (Tg) (JIS K 7121): 127 ° C, SP value: 7.4) and amorphous cycloolefin-based resin B (manufactured by Nippon Xeon Co., Ltd., trade name "Zenoa" 1060R ”, hydrogenated ring opening polymer of cyclic olefin, density (ISO 1183): 1.01 g / cm 3, MFR (230 ° C., 21.18 N, JIS K 7210): 12 g / 10 min, glass transition temperature (Tg) ( JIS K 7121): 100 degreeC, SP value: 7.4) Pellets, polypropylene resin (made by Nippon Polypro Co., Ltd., brand name "Novatec PP EA9", density (JIS K 7112): 0.9 g / cm <3>, MFR (230 ℃, 21.18 N, JIS K-7210): 0.5 g / 10 min, SP value: 8.0) pellets were mixed in a mass ratio of 50:25:25, then using a twin screw extruder heated to 230 ℃ Pelletized The resin composition B was produced.

(Production of reflective material)

The resin compositions A and B were fed to extruders A and B heated at 200 ° C. and 230 ° C., respectively, and melt-kneaded at 200 ° C. and 230 ° C. in each extruder, and then joined to T dies for two or three layers. It extruded in the sheet form so that it might become three-layered constitution of a resin layer (B) / resin layer (A) / resin layer (B), and it solidified by cooling and formed the laminated sheet.

After the obtained laminated sheet was stretched twice in MD at a temperature of 130 ° C., further biaxially stretched by three times tenter stretching in TD at 130 ° C. to give a thickness of 225 μm (resin layer (A): 191 μm, Resin layer (B): 17 micrometers, and the reflecting material (sample) of lamination ratio A: B = 5.6: 1 were obtained.

Evaluation similar to Example 1 was performed about the obtained reflector. In addition, arithmetic mean roughness Sa and light diffusivity were evaluated.

<Example 4>

(Preparation of the resin composition A of the resin layer (A))

Polypropylene resin (manufactured by Nippon Polypro Co., Ltd., trade name "Novatech PP FY6HA", density (JIS K 7112): 0.9 g / cm 3, MFR (230 ° C, 21.18 N, JIS K-7210): 2.4 g / 10 min, SP value: 8.0), pellets, and titanium (KRONOS Inc. oxide producing a trade name "KRONOS 2230", density 4.2 g / ㎤, rutile titanium, Al, Si surface oxidation treatment, 96.0% TiO ₂ content, the recipe: chlorine method) After mixing in the mass ratio of 50:50, it pelletized using the twin screw extruder heated at 270 degreeC, and the resin composition A was produced.

(Preparation of the resin composition B of the resin layer (B))

Styrene-based copolymer (manufactured by Toyo Styrene, trade name "T080", styrene-methacrylic acid copolymer, density (ISO 1183): 1.07 g / cm 3, glass transition temperature (Tg) (JIS K-7121): 123 ° C, Pellets of MFR (200 ° C., 49 N, JIS K-7210): 1.7 g / 10 min, SP value: 10.6), polypropylene resin (manufactured by Nippon Polypro Co., Ltd., trade name `` Novatech PP FY6HA '', density (JIS K 7112): 0.9 g / cm 3, MFR (230 ° C., 21.18 N, JIS K-7210): 2.4 g / 10 min, SP value: 8.0), after mixing in a mass ratio of 75: 25, 230 It pelletized using the twin screw extruder heated at degreeC, and the resin composition B was produced.

(Production of reflective material)

The resin compositions A and B were fed to extruders A and B heated at 200 ° C. and 230 ° C., respectively, and melt-kneaded at 200 ° C. and 230 ° C. in each extruder, and then joined to T dies for two or three layers. It extruded in the sheet form so that it might become three-layered constitution of a resin layer (B) / resin layer (A) / resin layer (B), and it solidified by cooling and formed the laminated sheet.

After the obtained laminated sheet was stretched twice in MD at a temperature of 130 ° C., further biaxially stretched by three times tenter stretching in TD at 130 ° C. to give a thickness of 225 μm (resin layer A: 191 μm, a resin layer). The reflector (sample) of B: 17 micrometers and lamination ratio A: B = 5.6: 1 was obtained.

Evaluation similar to Example 1 was performed about the obtained reflector.

About the reflectors of Examples 1-4, the result of the porosity, average reflectance, wavy wrinkle, and abrasion resistance was shown in Table 2. Moreover, about the reflector of Examples 3 and 4, the difference of the absolute value of SP value, Sa, a reflection component intensity ratio, and the result of light diffusivity are shown in Table 3.

From the results of Table 3, SP value is different, the absolute value of the difference of 0.3 to 3.0 (cal / ㎤) ^{0. 5} by the resin blends of two in the range, the surface roughness (Sa) at least 0.5 ㎛ It turned out that it can also be seen that it can express high light diffusivity.

Moreover, since the correlation of the absolute value of the difference of SP value and surface roughness Sa is seen, it turned out that the difference of the absolute value of the SP value of blend resin affects surface roughness Sa. Moreover, it turned out that heat resistance and bending resistance can be improved by selecting resin to blend with respect to blend resin, considering the absolute value of the difference of SP value.

Next, in the resin layer B of this reflector, it is confirmed that light diffusivity is expressed by designing so that it may become specific surface roughness Sa using the blend resin in which the difference of the absolute value of SP value exists in a specific range. In order to do this, the following experiment was conducted (see Reference Examples 1 and 2).

<Reference example 1>

(Production of Resin Composition B of Resin Layer B)

Pellets of amorphous cycloolefin-based resin C (manufactured by Nippon Xeon Co., Ltd., brand name "Zenoa RCY50", SP value: 7.4), and amorphous cycloolefin-based resin B (manufactured by Nippon Xeon Co., Ltd., brand name "Zenoa 1060R", SP The pellet of the value: 7.4) was mixed by the mass ratio of 67:33, and it pelletized using the twin screw extruder heated at 230 degreeC, and the resin composition B was produced.

(Production of biaxial drawing sheet)

After supplying the said resin composition B to the extruder heated at 230 degreeC, melt-kneading at 230 degreeC in the extruder, it extruded from the T die into the sheet form, and solidified by cooling, and formed the sheet | seat. The obtained sheet was double-stretched by MD at a temperature of 130 ° C., and then biaxially stretched by three-fold tenter stretching by TD at 130 ° C. to obtain a biaxially stretched sheet having a thickness of 180 μm.

Arithmetic mean roughness Sa and light diffusivity were evaluated similarly to Example 3 about the obtained biaxially stretched sheet.

<Reference example 2>

(Production of Resin Composition B of Resin Layer B)

The pellet of the styrene copolymer (Toyo Styrene company make, brand name "T080", SP value: 10.6) was made into the resin composition B as it was.

(Production of reflective material)

The said resin composition B was press-molded on the conditions of heating temperature 190 degreeC, press pressure 2 Mpa, pressurization time 10 minutes, and cooling time 15 minutes, and the press sheet (sample) of thickness 180micrometer was obtained.

Evaluation similar to the reference example 1 was performed about the obtained press sheet.

For the sheets of Reference Examples 1 and 2, Table 4 shows the results of the difference between the absolute values of the SP values, Sa, the reflection component intensity ratio, and the light diffusivity.

Reference Examples 1 and 2 assume the case where the resin layer (B) of the present reflector is a non-blend resin. In these cases, since the resin is a single resin, there is no difference in the SP value and from the reflection component intensity ratios shown in Table 4 It was confirmed that it did not express light diffusivity.

Therefore, in order that the resin layer (B) of this reflector may express light diffusivity, it turned out that it is necessary by blend resin to make surface roughness Sa of the resin layer (B) into 0.5 micrometer or more.

Claims (11)

At least one side of the resin layer (A) having voids therein is provided with a resin layer (B) containing two or more kinds of thermoplastic resins having different solubility parameters (SP values),
The resin layer (B) has arithmetic mean roughness Sa of three-dimensional surface roughness of 0.5 micrometers or more by combination of thermoplastic resin from which solubility parameter (SP value) differs, The reflection material characterized by the above-mentioned. On at least one surface of the resin layer (A) having pores therein, the solubility parameter can be the difference between the absolute value of (SP value) of the thermoplastic resin containing at least a 0.3 ~ 3.0 (cal / ㎤) 0. 5 2 jong resin layer (B Reflector provided with). 3. The method of claim 2,
The solubility difference between the absolute value of the parameter (SP value), characterized in that accounting for 0.3 ~ 3.0 (cal / ㎤) 0. 5 of two or more kinds of thermoplastic resin is a resin layer at least 70% by weight of the entire resin constituting the (B) reflector. The method according to any one of claims 1 to 3,
At least 1 sort (s) of resin which comprises a resin layer (B) is amorphous resin whose glass transition temperature (JIS K 7121) is 85-150 degreeC, The reflecting material characterized by the above-mentioned. The method of claim 4, wherein
The amorphous resin is a cycloolefin resin. 6. The method according to any one of claims 1 to 5,
Reflective material in which a resin layer (A) contains a fine powder filler. 7. The method according to any one of claims 1 to 6,
The porosity of a resin layer (A) is 20% or more and 70% or less, The reflecting material characterized by the above-mentioned. The method according to any one of claims 1 to 7,
The resin layer (A) contains an olefin resin, The reflector characterized by the above-mentioned. The method according to any one of claims 1 to 8,
The resin layer (B) is located in the outermost layer which is the reflection use surface of a reflection material, The reflection material characterized by the above-mentioned. 10. The method according to any one of claims 1 to 9,
The total thickness ratio of each layer of a resin layer (A) and a resin layer (B) is (A) :( B) = 3: 1-15: 1, The reflector characterized by the above-mentioned. 11. The method according to any one of claims 1 to 10,
It is used as a structural member of a liquid crystal display, a lighting fixture, or a lighting signboard, The reflector characterized by the above-mentioned.

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