JP2013003192A - Laminated reflective material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reflection film which is excellent in reflection performance and rigidity.SOLUTION: A laminated reflective material has lamination structure including a resin layer B which is formed of a resin composition B containing a styrene resin on at least one side of an unstretched foam layer A which is formed of a resin composition A containing an olefin resin, a fine powdered filler, a foaming agent and acrylic modified polytetrafluoroethylene and which has air pores inside.

Description

  The present invention relates to a reflective material that can be suitably used as a constituent member of a liquid crystal display, a lighting fixture, or a lighting signboard.

  Reflective materials are used in many fields such as liquid crystal displays, lighting fixtures or lighting signs. Recently, in the field of liquid crystal displays, devices have become larger and display performance has become more advanced, and it has become necessary to improve the performance of the backlight unit by supplying as much light as possible to the liquid crystal. With respect to materials, much better light reflection performance (also simply referred to as “reflection performance”) has been demanded.

As a reflective material, for example, a reflective film for a liquid crystal display using a white polyester film mainly composed of an aromatic polyester resin is known (see Patent Document 1).
However, when an aromatic polyester-based resin is used as a material for the reflector, the aromatic ring contained in the molecular chain of the aromatic polyester-based resin absorbs ultraviolet rays, and therefore, by ultraviolet rays emitted from a light source such as a liquid crystal display device, There was a problem that the film deteriorated and yellowed, and the reflective performance of the reflective film was lowered.

  Further, by stretching a film formed by adding a filler to a polypropylene resin, a fine void is formed in the film, and light scattering reflection is caused (refer to Patent Document 2), olefin-based It consists of a base material layer containing a resin and a filler, and an olefin-based resin light reflector (see Patent Document 3) having a laminated structure composed of a layer containing an olefin-based resin, and a thermoplastic resin composition containing a foaming agent. There is also known a light reflector (Patent Document 4) in which a base material layer is laminated with a film layer containing an olefin resin and a filler and stretched in one or more directions.

  Furthermore, in order to prevent the thermoformability from being impaired by stretching as described above, there is also known a reflector formed by forming voids with a foaming agent (see Patent Document 5).

Japanese Patent Laid-Open No. 04-239540 JP-A-11-174213 JP 2005-031653 A JP 2004-309804 A Japanese Patent Publication No. WO2006 / 115087

  When giving reflective performance to an olefin-based resin reflective film, as described above, it is common to obtain a reflective performance by forming a void in the film and using the refractive index difference between the air in the void and the base resin. It is.

  In recent years, especially in portable terminals such as mobile phones, portable game machines, and portable personal computers, miniaturization and thinning have progressed, and accordingly, the reflective material is also required to be thin. Therefore, in this type of olefin-based resin reflective film, if the thickness of the film is to be made thinner than before, it is necessary to increase the reflective performance by forming a large number of voids inside.

  In this way, in order to reduce the thickness of the reflective material, considering the purpose of forming a large number of voids, when the film is stretched to form voids, the voids are stretched and become large. It is not suitable for such purposes. Therefore, in the present invention, a void is formed using a foaming agent without stretching.

  However, in a resin composition containing an olefin-based resin, it is not easy to obtain excellent reflection performance even if it is thinned by forming many fine bubbles.

  Moreover, since the olefin resin reflecting material formed from the resin composition containing the olefin resin does not have sufficient rigidity, there is a problem that it is bent and wrinkled when incorporated as a constituent member of a liquid crystal display.

  Therefore, in view of such a problem, the object of the present invention relates to an olefin resin layer having an olefin resin as one of the main materials, forming a void with a foaming agent without stretching, and having excellent reflection performance even when thin. And providing a new laminated reflector having sufficient rigidity.

  The present invention is formed on at least one surface of an unstretched foamed layer A formed of a resin composition A containing an olefin resin, a fine powder filler, a foaming agent, and acrylic-modified polytetrafluoroethylene and having voids therein. The present invention proposes a laminated reflector having a laminated structure in which a resin layer B formed from a resin composition B containing a styrene resin is provided.

Even if a foam is formed inside the olefin resin composition containing an olefin resin and a foaming agent without blending with the foaming agent without stretching, As a result, an excellent reflection performance can be obtained even if it is thin.
Furthermore, by providing a laminated structure in which a resin layer B formed from a resin composition B containing a styrene resin is provided on at least one surface of an unstretched foamed layer formed from the olefin-based resin composition, Sufficient rigidity can be obtained.
Therefore, the laminated reflective material proposed by the present invention can be suitably used as a reflective material for liquid crystal displays, lighting fixtures, or lighting signs, for example.

  Hereinafter, a laminated reflecting material (referred to as “the present reflecting material”) as an example of an embodiment of the present invention will be described. However, the present invention is not limited to this reflector.

<This reflective material>
The reflective material is formed from a resin composition A containing an olefin resin, a fine powder filler, a foaming agent, and acrylic-modified polytetrafluoroethylene, and at least one surface of an unstretched foam layer A having voids therein. And a reflector having a laminated structure in which a resin layer B formed from a resin composition B containing a styrene-based resin is provided.

<Unstretched foam layer A>
The unstretched foam layer A is formed from a resin composition A containing an olefin resin, a fine powder filler, a foaming agent, and acrylic-modified polytetrafluoroethylene, and a void is formed using the foaming agent without being stretched. It is a layer that is formed, and is a layer that can provide excellent reflection performance even if it is thin.

(Olefin resin)
Examples of the olefin resin that forms the unstretched foam layer A include polypropylene resins such as polypropylene and propylene-ethylene copolymers, polyethylene resins such as polyethylene, high-density polyethylene, and low-density polyethylene, and ethylene-cyclic olefins. At least selected from cycloolefin resins such as copolymers (including the above-mentioned cycloolefin resins), olefin elastomers such as ethylene-propylene rubber (EPR) and ethylene-propylene-diene terpolymer (EPDM). One or two or more types of polyolefin-based resins can be mentioned.

  Among these, from the viewpoint of mechanical properties, flexibility, etc., polypropylene resins and polyethylene resins are preferable, and among them, from the viewpoint of high melting point and excellent heat resistance, and high mechanical properties such as elastic modulus. Polypropylene resin is preferable.

  Among polypropylene resins, from the viewpoint of extrusion moldability, the melt flow rate (referred to as “MFR”, JISK-7210, 230 ° C., load 21.18 N) is 0.1 g / 10 min or more and 20 g / 10 min or less, particularly 0. .2 g / 10 min or more and 10 g / 10 min or less, especially 0.5 g / 10 min or more and 5 g / 10 min or less is particularly preferable.

(Fine powder filler)
The unstretched foam layer A is important to contain a fine powder filler in order to obtain excellent reflection performance. By containing a fine powder filler, reflection performance can be obtained from refractive scattering due to a difference in refractive index.

Examples of the fine powder filler include inorganic fine powder and organic fine powder.
Inorganic fine powders include calcium carbonate, magnesium carbonate, barium carbonate, magnesium sulfate, barium sulfate, calcium sulfate, zinc oxide, magnesium oxide, calcium oxide, titanium oxide, zinc oxide, alumina, aluminum hydroxide, hydroxyapatite, silica, Examples include mica, talc, kaolin, clay, glass powder, asbestos powder, zeolite, silicate clay. Any of these may be used alone or in admixture of two or more. Among these, considering the difference in refractive index with the resin constituting the sheet, those having a large refractive index are preferable, and calcium carbonate, barium sulfate, titanium oxide or zinc oxide having a refractive index of 1.6 or more is used. Is particularly preferred.

  Among these, titanium oxide has a significantly higher refractive index than other inorganic fine powders, and can significantly increase the difference in refractive index from the olefin resin, so that it is more than when other inorganic fine powders are used. Excellent reflection performance can be obtained with a small amount. By using titanium oxide, high reflection performance can be obtained even if the thickness of the reflector is reduced. Therefore, it is more preferable to use a filler containing at least titanium oxide. In this case, the content of titanium oxide is 30% or more of the total mass of the inorganic fine powder, or a combination of organic fine powder and inorganic fine powder is used. When it does, it is preferable to set it as 30% or more of the total mass.

  As the titanium oxide used for the unstretched foam layer A, a crystalline titanium oxide such as anatase type or rutile type is preferable. Among them, a refractive index is 2.7 from the viewpoint of a large difference in refractive index from the olefin resin. The above titanium oxide is preferable. In this respect, rutile type titanium oxide is preferable.

  Further, it is particularly preferable to use high-purity titanium oxide having high purity among titanium oxides. Here, the high-purity titanium oxide means titanium oxide having a small light absorption ability with respect to visible light, that is, titanium oxide having a small content of coloring elements such as vanadium, iron, niobium, copper, and manganese.

Examples of high-purity titanium oxide include those produced by a chlorine process.
In the chlorine method process, rutile ore containing titanium oxide as a main component is reacted with chlorine gas in a high-temperature furnace of about 1000 ° C. to produce titanium tetrachloride first, and then this titanium tetrachloride is burned with oxygen, High purity titanium oxide can be obtained. There is a sulfuric acid process as an industrial method for producing titanium oxide, but the titanium oxide obtained by this method contains a large amount of colored elements such as vanadium, iron, copper, manganese, niobium, etc. Absorption capacity increases. Therefore, it is difficult to obtain high-purity titanium oxide by the sulfuric acid method process.

  In addition, in order to improve the dispersibility of the inorganic fine powder in the olefin resin, the surface of the fine powder filler is surface-treated with a silicon compound, a polyhydric alcohol compound, an amine compound, a fatty acid, a fatty acid ester, or the like. You may use what you gave.

  On the other hand, examples of the organic fine powder include polymer beads and polymer hollow particles, and these can be used alone or in combination of two or more. Moreover, you may use combining inorganic fine powder and organic fine powder.

  The fine powder filler preferably has a particle size of 0.05 μm or more and 15 μm or less, more preferably 0.1 μm or more and 10 μm or less. If the particle size of the filler is 0.05 μm or more, the dispersibility in the olefin resin does not decrease, and thus a homogeneous reflector can be obtained. When the particle size is 15 μm or less, the interface between the olefin resin and the fine powder filler is densely formed, and a reflective material with high reflection performance is obtained.

With respect to the content of the fine powder filler, if the content of the fine powder filler is 15% by mass or more of the resin composition A, the area of the interface between the olefin resin and the fine powder filler is sufficiently secured. And high reflection performance can be imparted to the reflective material. If content of a fine powder filler is 70 mass% or less of the resin composition A, the mechanical strength required for a reflector can be ensured.
From such a viewpoint, the content of the fine powder filler is based on the total mass of the resin composition A, that is, the total mass of the unstretched foamed layer A in consideration of the reflective performance, mechanical strength, productivity, etc. It is preferably 15 to 70% by mass, and more preferably 20% by mass or more or 60% by mass or less.

(Foaming agent)
There are various methods for forming a void in the interior, such as a method using a foaming agent, a method of lowering pressure by injecting a gas, and a method using stretching. Since it can be spherical or elliptical, and a large number of fine voids can be formed uniformly, this reflecting material employs a method of forming voids with a foaming agent without stretching.

  As the foaming agent, either a chemical foaming agent or a physical foaming agent can be used, and both can be used in combination.

  Examples of the chemical blowing agent include inorganic foaming agents such as carbonates such as sodium bicarbonate and ammonium carbonate. Examples of organic foaming agents include azo compounds (for example, azodicarbonamide, azobisisobutyronitrile, azodiaminobenzene, azohexahydrobenzonitrile, barium azodicarboxylate, etc.), nitroso compounds (for example, N, N ′ -Dinitrosopentamethylenetetramine, N, N′-dinitroso-N, N′-dimethylterephthalamide, t-butylaminonitrile, etc.), hydrazide compounds [eg p-toluenesulfonyl hydrazide, p, p′-oxybis (benzenesulfonyl) Hydrazide) and the like], and hydrazone compounds (for example, p-toluenesulfonylacetone hydrazone and the like). One or two or more of these can be used in combination.

However, since most organic chemical foaming agents contain nitrogen and may have a yellowish color or turn yellow over time, the reflective performance may be reduced. Is more preferable.
Furthermore, among the inorganic chemical foaming agents, those having a decomposition temperature near 160 ° C. have a decomposition temperature slightly lower than, for example, the processing temperature of polypropylene, so when using polypropylene as the base resin, Before the base resin melts, the foaming agent may foam and gas may escape. Therefore, an inorganic chemical foaming agent having a decomposition temperature higher than at least the processing temperature of the base resin may be used or used as an inorganic chemical foaming agent so that the foaming agent is decomposed after the base resin is melted. preferable. From this viewpoint, it is preferable to use or use an inorganic chemical foaming agent having a decomposition temperature of 200 ° C. or higher, particularly 220 ° C. or higher.

  As the physical foaming agent, a foaming agent composed of an inert gas or an inert gas is preferable. Specifically, for example, aliphatic hydrocarbons such as butane, pentane, hexane, propane, heptane, alicyclic hydrocarbons such as cyclopentane, cyclohexane, cyclobutane, dichlorodifluoromethane, dichlorofluoromethane, trichlorofluoromethane, One type or two or more types of halogenated hydrocarbons such as chloromethane, dichloromethane, chloroethane, dichlorotetrafluoroethane, trichlorotrifluoroethane, and perfluorocyclobutane can be used. Moreover, inorganic compounds, such as water, a carbon dioxide, pressurized air, can also be mentioned.

The content of the foaming agent is preferably adjusted according to the foaming ratio (porosity) of the reflective material intended for production, the amount of gas generated by the foaming agent, and the like.
If the content of the foaming agent is 0.001 part by mass or more with respect to 100 parts by mass of the olefin resin, formation of voids is sufficient, and a foamed sheet body excellent in reflection performance is easily obtained. On the other hand, if the content of the foaming agent is 20 parts by mass or less, it is easy to obtain a foamed sheet body having uniform and fine bubbles without causing collapse of bubbles due to an excessive foaming state, generation of coarse bubbles, and the like.
Therefore, from such a viewpoint, the content of the foaming agent is preferably 0.001 to 20 parts by mass, more preferably 0.01 parts by mass or more or 10 parts by mass with respect to 100 parts by mass of the olefin resin. It is as follows.

(Acrylic modified polytetrafluoroethylene)
By adding acrylic modified polytetrafluoroethylene to an olefin resin composition containing an olefin resin, an appropriate melt tension or elongational viscosity can be imparted to the olefin resin composition. Thus, when the resin composition is foamed, more uniform and fine bubbles can be formed.
This is because when an olefin resin composition containing an olefin resin is blended with an acrylic modified polytetrafluoroethylene and subjected to foam molding, the acrylic modified polytetrafluoroethylene is stretched due to a dense pseudo-crosslinking with the olefin resin composition. This is considered to be because it can be sufficiently suppressed and the bubble can be sufficiently prevented from becoming large. Incidentally, polytetrafluoroethylene that is not acrylic-modified has insufficient dispersibility and familiarity with the olefin-based resin composition, so that pseudo-crosslinking becomes rough, and as a result, bubbles become large.

The acrylic-modified polytetrafluoroethylene may be polytetrafluoroethylene containing acrylic as a copolymerization component.
Such an acrylic-modified polytetrafluoroethylene can be molded near the processing temperature (about 200 ° C.) of an olefin resin, particularly polypropylene resin, and has a characteristic that it has excellent affinity with the olefin resin, and is also a resin. By exhibiting an effect of improving workability by increasing the elongational viscosity at the time of melting the composition, it has an extremely excellent property of contributing to the formation of uniform and fine bubbles.

  As a typical example of a commercially available product of acrylic-modified polytetrafluoroethylene that can be used for the reflective material, for example, Methbrene A3000 (manufactured by Mitsubishi Rayon Co., Ltd.) can be mentioned.

Regarding the content of the acrylic modified polytetrafluoroethylene, if the content of the acrylic modified polytetrafluoroethylene is 5 parts by mass or more with respect to 100 parts by mass of the foaming agent, it is a case where bubbles are formed by the foaming agent. However, the bubbles can be formed small and uniformly. On the other hand, if it is 200 mass parts or less, since the resin viscosity at the time of a fusion | melting does not become high too much and workability is maintained, it is preferable.
From such a viewpoint, the content of the acrylic-modified polytetrafluoroethylene is preferably 5 to 200 parts by mass with respect to 100 parts by mass of the foaming agent (the total in the case of two or more types), or 10 parts by mass or more. It is more preferably 150 parts by mass or less, further preferably 15 parts by mass or more or 100 parts by mass or less, and most preferably 30 parts by mass or more or 70 parts by mass or less.

(Other ingredients)
The present resin composition A may contain other resins as necessary in addition to the olefin resin, fine powder filler, foaming agent and acrylic-modified polytetrafluoroethylene described above. Moreover, you may contain antioxidant, a light stabilizer, a heat stabilizer, a dispersing agent, a ultraviolet absorber, a fluorescent whitening agent, a compatibilizing agent, a lubricant, and other additives.

(This resin composition A)
If the elongation viscosity at the time of melting of the resin composition A is 10,000 (Pa · s) or more, the foaming is smoothly performed and the workability is improved sufficiently to form more uniform and fine bubbles. Since an effect is acquired, it is preferable. Moreover, if extension viscosity is 200,000 (Pa * s) or less, since the extension viscosity at the time of a fusion | melting does not become high too much and workability is maintained, it is preferable.
From this viewpoint, the elongation viscosity at the time of melting of the resin composition A is preferably in the range of 10,000 (Pa · s) to 200,000 (Pa · s), and more preferably 20,000 (Pa · s). More preferably, it is s) or more or 50,000 (Pa · s) or less.
The elongation viscosity here is a value at 200 ° C. and an elongation rate of 100 (1 / second).
The elongation viscosity at the time of melting of the resin composition A can be adjusted mainly by the content of acrylic-modified polytetrafluoroethylene, particularly the content of acrylic-modified polytetrafluoroethylene relative to the foaming agent.

(Unstretched foam layer A)
When the film is stretched to form voids, the voids are inevitably enlarged. Therefore, in this reflective material, in order to obtain excellent reflection performance even if it is thin by forming a large number of fine voids, the unstretched foamed layer A is not stretched but is formed with a foaming agent. .

  The void ratio of the unstretched foam layer (hereinafter also referred to as “foam layer”) preferably has fine voids in the range of 10% to 60% from the viewpoint of ensuring reflection performance. In other words, the porosity of the foamed layer, that is, the volume ratio of the voids in the foamed layer is preferably 10% or more and 60% or less, and particularly preferably 20% or more or 50% or less. By providing the voids in such a range, the whitening of the foam layer sufficiently proceeds, so that high reflection performance can be achieved, and the mechanical strength of the reflective material is reduced and does not break.

In addition, the porosity of a foam layer can be calculated | required by the following formula.
Measure the density of the unfoamed layer (denoted as “unfoamed layer density”) and the density of the layer after foaming (denoted as “foamed layer density”), and substitute it into the following formula to determine the porosity of the foamed layer ( %).
Porosity (%) = {(unfoamed layer density−foamed layer density) / unfoamed layer density} × 100

In addition, although the manufacturing method of a foaming layer is given and demonstrated below, an example is given, It is not limited to the following manufacturing method at all.
Since the olefin-based resin is generally melted by heating to a temperature of about 120 to 300 ° C., melt molding and heat processing are possible.
There is no particular limitation on the molding method, but for example, by various molding methods such as extrusion molding, injection molding, calender molding, press molding, casting, etc., foamed molded products or foamable molded products (before foaming) Molded product). In the case of the present foam layer, the foam layer is preferably formed by extrusion foam molding or injection foam molding.
When foaming is performed simultaneously with molding / processing, the molding / processing may be performed by heating to a temperature equal to or higher than the decomposition temperature of the foaming agent at least at a certain stage of molding / processing. Specifically, although the foaming temperature varies depending on the type of foaming agent, for example, a heat-decomposable foaming agent (chemical foaming agent) generally decomposes in the range of 150 to 250 ° C, so the foaming agent is decomposed to produce a foam layer. In order to achieve this, it is preferable to foam by heating to a temperature of 150 to 250 ° C. or higher.
On the other hand, after molding in an unfoamed state, it can be obtained by heating and foaming. In this case, after molding and processing at a temperature at which molding can be performed and at a temperature at which the foaming agent does not decompose, foaming is performed by heating an unfoamed molded product or the like to a temperature higher than the decomposition temperature of the foaming agent. A layer can be obtained.

<Resin layer B>
The resin layer B is a layer containing a styrene resin, and is a layer that can impart rigidity to the reflective material.
The resin layer B is normally unfoamed and unstretched, but may contain a foaming agent or may be stretched as necessary.

(Styrene resin)
The styrene resin that forms the resin layer B can be obtained by polymerizing a styrene monomer.
As a monomer used for the styrene resin, for example, styrene, α-methyl styrene, paramethyl styrene, ethyl styrene, propyl styrene, butyl styrene, chloro styrene, bromo styrene and the like can be used, and among them, styrene is preferable. .

In addition, a comonomer that can be copolymerized with styrene may be copolymerized with styrene within a range that does not impair the purpose of the styrene resin used in the present reflective material.
Examples of comonomer copolymerizable with styrene include (meth) acrylic acid esters such as methyl (meth) acrylate, ethyl (meth) acrylate, and butyl (meth) acrylate, α-methylstyrene, o-, m -, P-methylstyrene, bromostyrene, dibromostyrene, chlorostyrene, dichlorostyrene and other aromatic vinyl monomers other than styrene, (meth) acrylic acid, maleic acid, fumaric acid and other unsaturated fatty acids, anhydrous Examples thereof include unsaturated difatty acid anhydrides such as maleic acid and itaconic anhydride, and unsaturated difatty acid imides such as N-phenylmaleimide. These monomers may be used alone or in combination of two or more.

  Among the copolymers of the above comonomer and styrene, for example, styrene-α-methylstyrene copolymer (SAMS), styrene-acrylic acid copolymer (SAA), styrene-methacrylic acid copolymer (SMAA), A styrene copolymer such as a styrene-maleic anhydride copolymer (SMA) can be preferably used in the present reflective material as a styrene resin having transparency and rigidity and improved heat resistance.

In addition, as a styrenic resin with improved heat resistance, for example, syndiotactic polystyrene may be mentioned. Preferred syndiotactic polystyrenes include polystyrene, poly (p-methylstyrene), poly (m-methylstyrene), poly (p-tertiary butylstyrene), poly (p-chlorostyrene), poly (m-chlorostyrene). ), Poly (p-fluorostyrene), hydrogenated polystyrene, and copolymers containing these structural units.
Here, syndiotactic polystyrene is a styrenic polymer having a syndiotactic structure, and syndiotacticity determined by nuclear magnetic resonance (13C-NMR) is usually 75 for racemic dyads. % Or more, preferably 85% or more. In racemic pentad, it is usually 30% or more, preferably 50% or more.

  Moreover, in this reflective material, the said styrene resin can be used in combination of 2 or more type.

  The content of the styrene resin (the total of these when a styrene resin of two or more components is included) is preferably 50% by mass or more based on the total mass of the resin composition B, and more preferably. Is 60% by mass or more, particularly preferably 70% by mass or more (including 100%).

(Other resin components)
The resin layer B can also contain other resins in addition to the styrene resin. For example, from the viewpoint of enhancing the adhesion between the unstretched foam layer A and the resin layer B, it is preferable to contain an olefin resin, a thermoplastic elastomer, or both of them.

At this time, the melt flow rate (referred to as “MFR”, JISK-7210, 230 ° C., load 21.18 N) of the olefin resin and the thermoplastic elastomer is 0.1 g / 10 min or more and 40 g / 10 min or less. In particular, it is more preferably 0.5 g / 10 min or more and 20 g / 10 min or less.
It is also preferable to adjust the MFR of the styrene resin to the above range. Thus, when both MFRs are adjusted, the olefinic resin and / or the thermoplastic elastomer are not particularly likely to be oriented in the styrene resin and extremely deteriorate the mechanical properties as the reflector. .

Examples of the olefin resin include polypropylene resins such as polypropylene and propylene-ethylene copolymer, and polyethylene resins such as polyethylene, high-density polyethylene, and low-density polyethylene. A combination of more than one species can be used. Of these, polyethylene resins and polypropylene resins are preferable, and among them, polypropylene resins are preferable from the viewpoints of high melting point and excellent heat resistance and high mechanical properties such as elastic modulus.
Also, from the viewpoint of extrusion moldability, among polypropylene resins, the melt flow rate (referred to as “MFR”, JISK-7210, 230 ° C., 21.18 N) is 0.1 g / 10 min to 20 g / 10 min, especially 0.8. Polypropylene resins having 2 g / 10 min to 10 g / 10 min, particularly 0.5 g / 10 min to 5 g / 10 min are particularly preferable.

In addition, when the resin layer B contains an olefin resin, the olefin resin of the resin layer B is an olefin resin of the unstretched foam layer A from the viewpoint of improving the adhesion between the unstretched foam layer A and the resin layer B. It is preferable to contain the olefin resin containing the same monomer unit.
Therefore, for example, when the olefin resin of the unstretched foam layer A is a polypropylene resin, the resin layer B preferably contains a polypropylene resin as the olefin resin.

  On the other hand, examples of the thermoplastic elastomer include olefin-based elastomers, styrene-based elastomers, urethane-based elastomers, polyester-based elastomers, and the like, and one or more of these can be used in combination. Among them, the styrene elastomer is preferable from the viewpoint of improving the adhesion between the unstretched foam layer A and the resin layer B because it is compatible with not only the styrene resin but also the olefin resin, particularly the polypropylene resin.

Examples of the styrene-based elastomer include a copolymer of styrene and a conjugated diene such as butadiene or isoprene, and / or a hydrogenated product thereof. The styrene-based elastomer is a block copolymer having styrene as a hard segment and conjugated diene as a soft segment, and does not require a vulcanization step, and is preferable. A hydrogenated product is more preferable because of high thermal stability.
Preferred examples of the styrene elastomer include, for example, a styrene-butadiene-styrene block copolymer, a styrene-isoprene-styrene block copolymer, a styrene-ethylene-butylene-styrene block copolymer, and a styrene-butadiene-butylene-styrene. Mention may be made of copolymers and styrene-ethylene-propylene-styrene block copolymers.
In particular, styrene-ethylene-butylene-styrene block copolymers, styrene-butadiene-butylene-styrene copolymers, styrene-ethylene-propylene-styrene block copolymers, which have lost the double bond of the conjugated diene component by hydrogenation. A coalescence (also referred to as a hydrogenated styrene-based elastomer) is preferable.

  The content of the olefin resin other than the styrene resin and / or the thermoplastic elastomer contained in the resin layer B is preferably 5 to 45% by mass with respect to the mass of the entire resin layer B, and 10 to 30 More preferably, it is mass%.

(Fine powder filler)
The resin layer B may contain a fine powder filler from the viewpoint of improving the reflection performance. The type, particle size, and surface treatment method of the fine powder filler are the same as those described for the unstretched foam layer A, and the preferred examples are also the same.

(Other ingredients)
The resin layer B may contain other resins (including syndiotactic polystyrene and the like) as long as the effects of the styrene resin, the olefin resin, and / or the thermoplastic elastomer are not impaired. Moreover, you may contain antioxidant, a light stabilizer, a heat stabilizer, a dispersing agent, a ultraviolet absorber, a fluorescent whitening agent, a compatibilizing agent, and other additives within the range which does not impair the said effect.

(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 of the molten resin composition by extrusion or coating (without forming a sheet).

<Laminated structure of the reflective material>
This reflector needs to have a laminated structure in which the unstretched foam layer A and the resin layer B are provided. By adopting such a configuration, it becomes possible to perform functional separation such as imparting rigidity to the resin layer B while imparting reflection performance to the unstretched foam layer A, and exhibiting excellent reflection performance while providing rigidity. There is an advantage that it can be given. Therefore, in such a laminated structure, it is preferable that the resin layer B is located in the outermost layer on the light irradiation side (reflection use surface side). By setting it as such a structure, rigidity can be provided to a reflecting material.

  Moreover, as another laminated structure, the laminated structure of 3 layers which provided the resin layer B on both surfaces of the unstretched foam layer A can be mentioned, for example. Furthermore, in addition to the unstretched foam layer A and the resin layer B, other layers may be provided, or other layers may be interposed between the unstretched foam layer A and the resin layer B. For example, an adhesive layer may be interposed between the unstretched foam layer A and the resin layer B.

<Thickness of this reflector>
The thickness of the reflective material is not particularly limited, and is preferably, for example, 30 μm to 1500 μm, and particularly preferably 50 μm or more or 1000 μm or less in view of handling in practical use.
For example, the reflective material for use in liquid crystal displays preferably has a thickness of 50 μm to 700 μm. For example, the reflective material for use in lighting fixtures or lighting signboards preferably has a thickness of 100 μm or more or 1000 μm or less.

  As can be seen from the results of Examples to be described later, even if the resin layer B is thin, the rigidity of the entire reflecting material can be increased. On the other hand, if the resin layer B is too thick, the reflection performance is deteriorated. From such a viewpoint, the total thickness ratio of the unstretched foam layer A and the resin layer B (for example, the ratio of the total thickness of the two layers when there are two unstretched foam layers A) is 2: 1 to 15: Is preferably 1, and more preferably 2: 1 to 10: 1.

<Reflectance of this reflector>
The reflective material preferably has a reflectance of at least one surface of 85% or more with respect to light having a wavelength of 550 nm, more preferably 90% or more, and particularly preferably 95% or more. If it has such a reflection performance, it exhibits good reflection characteristics as a reflective material, and a liquid crystal display or the like incorporating this reflective material can achieve a sufficient brightness of the screen.

<Bending rigidity of this reflector>
The reflective material preferably has a flexural modulus of 15,000 (kgf / cm ² ) or more, more preferably 20,000 (kgf / cm ² ) or more, and 30,000 (kgf / cm ² ). Most preferably, it is at least cm ² ). If the bending rigidity is 15,000 (kgf / cm ² ) or more, the rigidity is sufficient, and when incorporated as a constituent member of a liquid crystal display, it is not bent and wrinkles are preferable.

<Manufacturing method of the present reflective material>
The method for producing the reflective material is not particularly limited, and a known method can be adopted. Below, although the manufacturing method of a reflecting material is described with an example, it is not limited to the following manufacturing method.

  Here, an example of the suitable manufacturing method of this reflective material is introduced.

  First, a blend in which a fine powder filler, acrylic-modified polytetrafluoroethylene, and other additives are blended with an olefin resin as required is prepared. Specifically, a fine powder filler or the like is added to the olefin resin as a main component and mixed with a ribbon blender, tumbler, Henschel mixer, etc., and then a Banbury mixer, a single screw or twin screw extruder is used. Thus, a blend can be obtained by kneading at a temperature equal to or higher than the melting point of the resin (eg, 190 ° C. to 270 ° C.). Alternatively, a blend can be obtained by adding a predetermined amount of an olefin resin, a fine powder filler or the like with a separate feeder or the like. In addition, a so-called master batch in which a fine powder filler, acrylic-modified polytetrafluoroethylene, other additives, etc. are mixed in advance in an olefin resin at a high concentration is prepared, and the master batch and the olefin resin are mixed. It is also possible to obtain a formulation with a desired concentration.

  Next, after drying the compound thus obtained, a predetermined amount of a heat decomposable foaming agent (chemical foaming agent) is added to obtain a resin composition A.

  On the other hand, a resin composition B in which an olefin resin and / or a thermoplastic elastomer and other additives are blended with a styrene resin as required is prepared. Specifically, an olefin resin and / or thermoplastic elastomer, other antioxidants, and the like are added to the styrene resin as necessary, mixed with a ribbon blender, tumbler, Henschel mixer, etc., and then a Banbury mixer, uniaxial Alternatively, the resin composition B can be obtained by kneading at a temperature equal to or higher than the melting point of the resin (for example, 200 ° C. to 280 ° C.) using a twin screw extruder or the like. Moreover, the resin composition B can be obtained by adding a predetermined amount of a styrene resin, an olefin resin, and / or a thermoplastic elastomer with a separate feeder or the like. Also, a so-called master batch in which an olefin resin and / or thermoplastic elastomer and other antioxidants are blended at a high concentration in advance is prepared, and this master batch and a styrene resin, an olefin resin and / or a thermoplastic are prepared. The resin composition B having a desired concentration can be obtained by mixing with an elastomer.

Next, after drying the resin compositions A and B thus obtained, they are supplied to different extruders, respectively, heated to a predetermined temperature or higher and melted.
Conditions such as the extrusion temperature need to be set in consideration of a decrease in molecular weight due to decomposition. On the other hand, heat-decomposable foaming agents generally decompose in the range of 150 to 250 ° C. In order to decompose the agent to form a foam, the temperature is set to 150 to 250 ° C. or higher. For example, the extrusion temperature of the resin composition A is preferably 150 to 250 ° C., and the extrusion temperature of the resin composition B is preferably 200 ° C. to 280 ° C.
Thereafter, the melted resin composition A and resin composition B are merged into a T-die for 2 types and 3 layers, extruded from a slit-like discharge port of the T die in a laminated form, and solidified closely to a cooling roll, unstretched What is necessary is just to make it form the sheet | seat body provided with the laminated structure of 3 layers which provided the resin layer B on both surfaces of the foaming layer A. FIG.

The sheet body thus obtained may be used as a reflection material as it is, or another material may be used as a base material, laminated with the base material, or combined with a base material and a method other than the lamination to be combined. In addition, a reflective material may be used.
Examples of the substrate in this case include films, sheets, plates, and other shapes made of plastic or rubber, or foils, sheets, plates, and other shapes made of metal.

As a method for combining the sheet body and the base material, for example, after the sheet body is manufactured, the sheet body may be integrally combined with the base material. In addition, when the resin composition A is foamed, it may be integrated with the base material at the same time. Further, it may be combined with the base material before foaming and then foamed.
For such composite integration, any method such as a method of performing lamination simultaneously with molding such as thermocompression bonding, adhesive bonding, extrusion lamination, etc., depending on the affinity and adhesiveness during compounding, etc. Can be used.

<Uses of this reflective material>
The reflective material can be used as a reflective material as it is, but it can also be used as a structure in which the reflective material is laminated on a metal plate or a resin plate, for example, a liquid crystal display such as a liquid crystal display. It is useful as a reflector used in devices, lighting fixtures, lighting signs, and the like.

  In this case, examples of the metal plate on which the reflective material is laminated include an aluminum plate, a stainless plate, and a galvanized steel plate.

  Examples of the method of laminating the reflective material on a metal plate or resin plate include a method using an adhesive, a method of heat-sealing without using an adhesive, a method of bonding via an adhesive sheet, and extrusion coating. And the like. However, it is not limited to these methods.

More specifically, an adhesive such as polyester, polyurethane, or epoxy is applied to the surface of the metal plate or resin plate (collectively referred to as “metal plate, etc.”) to which the reflective material is to be bonded. Can be pasted together.
In such a method, a commonly used coating facility such as a reverse roll coater or a kiss roll coater is used, and the adhesive film thickness after drying is about 2 μm to 4 μm on the surface of a metal plate or the like on which a reflective material is bonded. Apply an adhesive so that
Next, the coated surface is dried and heated with an infrared heater and a hot air heating furnace, and while maintaining the surface of the metal plate or the like at a predetermined temperature, the reflecting material is immediately coated and cooled using a roll laminator, and reflected. You can get a board.

The reflective material is useful as a reflective member for use in a liquid crystal display device such as a liquid crystal display, a lighting fixture, and a lighting signboard.
In general, a liquid crystal display includes 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, and the like.
This reflector can also be used as a reflector that plays a role of making light from a light source efficiently enter a liquid crystal panel or a light guide plate, or condenses light emitted from a light source disposed at an edge portion to guide the light guide plate. It can also be used as a light source reflector having a role of being incident on the light source.

<Explanation of terms>
In general, "film" refers to a thin flat product that is extremely small compared to its length and width and whose maximum thickness is arbitrarily limited, and is usually supplied in the form of a roll (Japan) Industrial standard JISK6900), and in general, “sheet” refers to a product that is thin by definition in JIS and generally has a thickness that is small instead of length and width. However, since the boundary between the sheet and the film is not clear and it is not necessary to distinguish the two in terms of the present invention, in the present invention, even when the term “film” is used, the term “sheet” is included and the term “sheet” is used. In some cases, “film” is included.

  In addition, the expression “main component” in the present specification includes the meaning of allowing other components to be contained within a range that does not hinder the function of the main component unless otherwise specified. At this time, although the content ratio of the main component is not specified, the main component (when two or more components are main components, the total amount thereof) is 50% by mass or more, preferably 70% in the composition. It occupies at least 90% by mass, particularly preferably at least 90% by mass (including 100%).

In the present invention, when expressed as “X to Y” (X and Y are arbitrary numbers), “X is preferably greater than X” and “preferably Y”, with the meaning of “X to Y” unless otherwise specified. It means “smaller”.
Further, in the present invention, when expressed as “X or more” (X is an arbitrary number), it means “preferably larger than X” unless otherwise specified, and “Y or less” (Y is an arbitrary number). ) Includes the meaning of “preferably smaller than Y” unless otherwise specified.

  The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to these examples, and various applications are possible without departing from the technical idea of the present invention.

<Measurement and evaluation method>
First, measurement methods and evaluation methods for various physical property values of samples obtained in Examples and Comparative Examples will be described.

(Elongation viscosity of resin composition A)
Using an elevated flow tester (“CFT-500C”, manufactured by Shimadzu Corporation), the extensional viscosity was measured under the following conditions.
Used nozzle: 1 mm diameter x 10 mm length and 0 mm
Preheating time: 5 minutes Measurement temperature: 200 ° C
Elongation speed: 100 (1 / second)

(Porosity of unstretched foam layer A)
Measure the density of the unfoamed layer (denoted as “unfoamed layer density”) and the density of the layer after foaming (denoted as “foamed layer density”), and substitute it into the following formula to determine the porosity of the foamed layer ( %).
Porosity (%) of unstretched foam layer A = {(unfoamed layer density−foamed layer density) / unfoamed layer density} × 100

(Reflectance)
An integrating sphere was attached to a spectrophotometer (“U-3900H”, manufactured by Hitachi, Ltd.), and the reflectance with respect to light having a wavelength of 550 nm was measured. Before the measurement, the photometer was set so that the reflectance of the alumina white plate was 100%.

(rigidity)
In accordance with JIS P-8125, the bending stiffness (g · cm) was measured under the following conditions, and the bending rigidity (kgf / cm ² ) of the sheet was determined by substituting it into the following formula.
・ Measuring device: Taber V-5 bending stiffness tester 150-B type (Taber)
・ Bending angle: 15 degrees ・ Bending rigidity = 2 × 0.01 / (sample thickness) ³ × bending stiffness

Rigidity was evaluated in light of the bending rigidity ratio described below. However, the symbols “◯” and “Δ” are above the practical level.
Evaluation criteria:
“◯”: Bending rigidity is 30,000 (kgf / cm ² ) or more “Δ”: Bending rigidity is 15,000 (kgf / cm ² ) or more “×”: Bending rigidity is 15,000 (kgf / kg) cm ² )

<Example 1>
(Preparation of resin composition A-1)
Polypropylene resin (Nippon Polypro Co., Ltd., trade name “NOVATEC PP FY6HA”, density (JISK-7112): 0.9 g / cm ³ , MFR (230 ° C., 21.18 N, JISK-7210): 2.4 g / 10 min ) Pellets and titanium oxide (trade name “KRONOS 2230” manufactured by KRONOS, density 4.2 g / cm ³ , rutile titanium oxide, Al, Si surface treatment, TiO ₂ content 96.0%, manufacturing method: chlorine Method), acrylic modified polytetrafluoroethylene (Mitsubishi Rayon Co., Ltd., trade name “METABREN A3000”) was mixed at a mass ratio of 59: 40: 1, and then a twin screw extruder heated at 270 ° C. was used. And pelletized. This pellet and a chemical foaming agent (manufactured by Sankyo Kasei Co., Ltd., trade name “Celmic MB3094”) were mixed at a mass ratio of 98: 2 to prepare a resin composition A-1.

(Preparation of resin composition B-1)
Styrene resin (trade name “T080” manufactured by Toyo Styrene Co., Ltd., density (ISO1183): 1.07 cm ³ , glass transition temperature Tg (JISK-7121): 125 ° C.), MFR (200 ° C., 49 N, JISK-7210) : 1.7 g / 10 min) pellets, polypropylene resin (made by Nippon Polypro, trade name “Novatech PP FY6HA”), styrene elastomer (made by Asahi Kasei Corporation, trade name “Tuftec P2000”, styrene-butadiene) A pellet of butylene-styrene copolymer, MFR (230 ° C., 21.18N, JISK-7210): 35 g / 10 min) was mixed at a mass ratio of 75:15:10, and then heated to 220 ° C. It pelletized using the axial extruder and produced resin composition B-1.

(Production of reflective material)
The resin compositions A-1 and B-1 are respectively supplied to extruders A and B heated to 230 ° C., and melt-kneaded at 230 ° C. and 230 ° C. in each extruder, and then set to 170 ° C. The two types of three-layer T-dies are joined together, extruded into a sheet shape so as to have a three-layer structure of resin layer B-1 / unstretched foam layer A-1 / resin layer B-1, cooled and solidified, and laminated. A sheet-like reflector was obtained. The obtained reflecting material had a thickness of 400 μm (unstretched foam layer A-1: 300 μm, resin layer B-1: 50 μm, lamination ratio A-1: B-1 = 3: 1).
The obtained reflecting material was evaluated for porosity, reflectance, and rigidity. In addition, regarding the porosity, it evaluated about the unstretched foam layer A-1. That is, the resin composition A-1 was supplied to the extruder A, and a single layer sheet (thickness 300 μm) of only the unstretched foam layer A-1 was obtained and evaluated according to the above operation. Moreover, about the resin composition A-1, the extensional viscosity was evaluated.

<Example 2>
In the production of the resin composition A-1 of Example 1, polypropylene pellets (trade name “Novatech PP FY6HA” manufactured by Nippon Polypro Co., Ltd.), titanium oxide (trade name “KRONOS 2230” manufactured by KRONOS Co., Ltd.), acrylic A modified polytetrafluoroethylene (Mitsubishi Rayon Co., Ltd., trade name “Metabrene A3000”) was mixed in a mass ratio of 79: 20: 1 in the same manner as in Example 1 except that the thickness was 400 μm (not yet A reflecting material having a stretched foam layer A-2: 300 μm and a resin layer B-1: 50 μm (lamination ratio A-2: B-1 = 3: 1) was obtained. Evaluation similar to Example 1 was performed about the obtained reflecting material and the resin composition.

<Example 3>
(Preparation of resin composition A-3)
In the production of the resin composition A-1 of Example 1, polypropylene pellets (trade name “Novatech PP FY6HA” manufactured by Nippon Polypro Co., Ltd.), titanium oxide (trade name “KRONOS 2230” manufactured by KRONOS Co., Ltd.), acrylic Resin composition A-3 was prepared in the same manner as in Example 1 except that modified polytetrafluoroethylene (trade name “METABBRENE A3000” manufactured by Mitsubishi Rayon Co., Ltd.) was mixed at a mass ratio of 69: 30: 1. Was made.

(Production of reflective material)
The above resin compositions A-3 and B-1 were respectively supplied to extruders A and B heated to 230 ° C., and each extruder was melt-kneaded at 230 ° C. and then set to 170 ° C. Merged into a three-layer T-die, extruded into a sheet shape so as to have a three-layer structure of resin layer B-1 / unstretched foam layer A-3 / resin layer B-1, cooled and solidified to form a laminated sheet A reflector was obtained. However, in the extruder A, carbon dioxide gas (carbon dioxide) is pressed into the melt-kneaded resin composition A-3 at a ratio of 0.005 parts by weight with respect to 100 parts by weight of the olefin resin, and further melt-kneaded. After that, it was joined to a T die. The obtained reflecting material had a thickness of 400 μm (unstretched foam layer A-3: 300 μm, resin layer B-1: 50 μm, lamination ratio A-3: B-1 = 3: 1).
Evaluation similar to Example 1 was performed about the obtained reflecting material and the resin composition.

<Example 4>
In the production of the resin composition A-1 of Example 1, polypropylene pellets (trade name “Novatech PP FY6HA” manufactured by Nippon Polypro Co., Ltd.), titanium oxide (trade name “KRONOS 2230” manufactured by KRONOS Co., Ltd.), acrylic Except that the modified polytetrafluoroethylene (manufactured by Mitsubishi Rayon Co., Ltd., trade name “Metabrene A3000”) was mixed at a mass ratio of 88.5: 10: 1.5 to prepare a resin composition A-4. In the same manner as in Example 1, a reflective material having a thickness of 400 μm (unstretched foam layer A-4: 300 μm, resin layer B-1: 50 μm, lamination ratio A-4: B-1 = 3: 1) was obtained. . Evaluation similar to Example 1 was performed about the obtained reflecting material and the resin composition.

<Example 5>
In the production of the reflector of Example 4, except that the thickness was 400 μm (unstretched foam layer A-4: 250 μm, resin layer B-1: 75 μm, lamination ratio A-4: B-1 = 5: 3). Thus, a reflective material was obtained in the same manner as in Example 1. Evaluation similar to Example 1 was performed about the obtained reflecting material and the resin composition.

<Comparative Example 1>
Only the resin composition A-1 in Example 1 is supplied to an extruder A heated to 230 ° C., melted and kneaded at 230 ° C. in the extruder A, and then supplied to a single-layer T-die set at 170 ° C. Then, it was extruded into a sheet and cooled and solidified to form an unstretched foam having a thickness of 300 μm, which was used as a reflector. Evaluation similar to Example 1 was performed about the obtained reflecting material and resin composition A-1.

<Comparative example 2>
In the production of the resin composition A-1 of Example 1, a pellet of polypropylene-based resin (manufactured by Nippon Polypro Co., Ltd., trade name “Novatech PP FY6HA”) and acrylic-modified polytetrafluoroethylene (manufactured by Mitsubishi Rayon Co., Ltd., trade name “ And a thickness of 400 μm (unstretched foaming) in the same manner as in Example 1, except that a resin composition A-5 was prepared by mixing 99.5: 1.5 in a mass ratio. A reflective material having a layer A-5: 300 μm and a resin layer B-1: 50 μm and a lamination ratio A-4: B-1 = 3: 1) was obtained. Evaluation similar to Example 1 was performed about the obtained reflecting material and the resin composition.

  As is clear from Table 1, it was found that the reflective materials of Examples 1 to 5 and Comparative Example 1 had a reflectance of 85% or more with respect to light having a wavelength of 420 nm to 700 nm and high reflection performance. Among these, it was found that the reflective materials of Examples 1 to 4 and Comparative Example 1 have a particularly high reflection performance with a reflectance of 90% or more with respect to light having a wavelength of 420 nm to 700 nm.

Furthermore, it turned out that the reflective material of Examples 1-5 is excellent also in the point of rigidity. Since the reflective material of Example 5 had a lamination ratio A: B = 5: 3, the reflectance was less than 90%, but it was found that the reflector was excellent in terms of rigidity.
On the other hand, since the reflective material of Comparative Example 1 does not have the resin layer B formed from the resin composition B, the flexural rigidity is less than 15,000 (kgf / cm ² ), and the rigidity may be inferior. all right.
Moreover, since the unstretched foamed layer is formed with the resin composition A which does not contain a fine powder filler, the reflective material of Comparative Example 2 does not reach 70% of reflectance and is inferior in reflective performance. It was.
As mentioned above, it turned out that the reflective material of Examples 1-5 is equipped with favorable reflective performance and rigidity.

Claims (15)

  A styrenic resin is formed on at least one surface of an unstretched foamed layer A having a void inside formed from a resin composition A containing an olefinic resin, a fine powder filler, a foaming agent, and acrylic-modified polytetrafluoroethylene. A laminated reflector having a laminated structure in which a resin layer B formed from a resin composition B containing bismuth is provided.   The laminated reflector according to claim 1, wherein the foaming agent is a chemical foaming agent, a physical foaming agent, or both.   Content of a foaming agent exists in the range of 0.001-20 mass parts with respect to 100 mass parts of olefin resin in the unstretched foamed layer A, The lamination | stacking reflection of Claim 1 or 2 characterized by the above-mentioned. Wood.   The content of acrylic-modified polytetrafluoroethylene is in the range of 5 to 200 parts by mass with respect to 100 parts by mass of the foaming agent.   The laminated reflector according to claim 1, wherein the unstretched foam layer A has a porosity of 10 to 60%.   The laminated reflection according to any one of claims 1 to 5, wherein the fine powder filler is one or more selected from the group consisting of calcium carbonate, zinc oxide, barium sulfate and titanium oxide. Wood.   Content of a fine powder filler is 15-70 mass% with respect to the whole mass of the resin composition A, The laminated reflective material in any one of Claims 1-6 characterized by the above-mentioned.   The elongation viscosity at the time of melting of the resin composition A constituting the unstretched foam layer A is in the range of 10,000 (Pa · s) to 200,000 (Pa · s). The laminated reflective material according to any one of 7 above.   The resin layer B is formed from a resin composition B containing an olefin resin, a thermoplastic elastomer, or both in addition to a styrene resin. The laminated reflective material described.   The resin layer B contains an olefin resin in addition to the styrene resin, and the unstretched foam layer A contains an olefin resin containing the same monomer unit as the olefin resin of the resin layer B. The laminated reflector according to any one of claims 1 to 9, wherein   The laminated reflector according to any one of claims 1 to 10, wherein the resin layer B is located in an outermost layer which is a reflection use surface of the laminated reflector. Layered reflector according to any one of the preceding claims flexural rigidity of the laminated reflective material, characterized in that at 15,000 (kgf / cm ²⁾ or more.   The thickness ratio of each layer total of the unstretched foam layer A and the resin layer B is unstretched foam layer A: resin layer B = 2: 1 to 15: 1, Any one of Claims 1-12 characterized by the above-mentioned. Reflective material according to.   A reflector comprising a structure obtained by laminating the laminated reflector according to any one of claims 1 to 13 on a metal plate or a resin plate.   It is used as a structural member of a liquid crystal display, a lighting fixture, or an illumination signboard, The laminated reflective material in any one of Claims 1-13 characterized by the above-mentioned.