JP2010086725A - Reflector - Google Patents

Abstract

【Task】
As a method for making the film exhibit excellent light reflectivity, a film is formed by mixing a white pigment and a thermoplastic resin incompatible with the film-constituting resin to form minute bubbles in the film. Is thin enough to obtain the necessary reflectivity, but the film is not stiff and has problems in handling such as easy wrinkles when incorporated in liquid crystal display devices, lighting fixtures, lighting signs, etc. It was.
[Solution]
Aliphatic polyester resin, thermoplastic resin incompatible with aliphatic polyester resin, SEBS compound or glycidyl methacrylate-ethylene copolymer, or a mixture thereof, and fine powder filling A reflector having a resin layer A formed from an aliphatic polyester resin composition containing an agent and a B layer made of polystyrene paper or synthetic paper is provided.
[Selection figure] None

Description

  The present invention relates to a reflector that can be used as a constituent member of a liquid crystal display, a lighting fixture, a lighting signboard, and the like.

  Reflectors are used in many fields, including liquid crystal display devices, lighting fixtures, and lighting signs. Recently, especially in the field of liquid crystal display devices, the size of the device and the advancement of display performance have progressed, and it has been required to improve the performance of the backlight unit by supplying as much light as possible to the liquid crystal. Further improved light reflectivity (also simply referred to as “reflectivity”) has been demanded for a plate, particularly a reflection film constituting a reflection plate.

  As a method of developing excellent light reflectivity in a film, there is known a method of forming fine bubbles in a film by mixing a white pigment and a thermoplastic resin incompatible with a film constituent resin. It has been. (See Patent Document 1)

JP 2004-123784 A

The film obtained by the above method is thin enough to obtain the required reflectivity, but the film is not stiff and handling properties such as easy wrinkles when incorporated in liquid crystal display devices, lighting fixtures, lighting signs, etc. Had problems.
In addition, when a reflective film is incorporated as a reflective material for a large-sized liquid crystal television or the like, the reflective film is exposed to a light source for a long time and used in a high-temperature environment. It was.

  The present invention has been made to solve the above problems, and the present invention provides a reflective material that achieves excellent reflection performance and has little dimensional change even when stored in a high temperature environment. Objective.

  A laminate having a resin layer A formed from a resin composition A and a B layer made of polystyrene paper or synthetic paper, the resin composition A comprising an aliphatic polyester resin and the aliphatic polyester resin An aliphatic polyester resin composition comprising a thermoplastic resin that is incompatible with the resin, a compatibilizer that is a SEBS compound or a glycidyl methacrylate-ethylene copolymer, or a mixture thereof, and a fine filler. And the shrinkage after heating at 80 ° C. for 3 hours is 0% to 2% in the direction parallel to the flow direction of the laminate and 0% to 2% in the direction perpendicular to the flow direction of the laminate. A characteristic reflector is proposed.

  The laminate further contains an aliphatic polyester resin and a fine powder filler, and an aliphatic polyester resin not containing a thermoplastic resin and a compatibilizer incompatible with the aliphatic polyester resin. A reflector having a resin layer C formed from the composition C is proposed.

  It is proposed that the B layer polystyrene paper has been annealed for 10 minutes or more in an atmosphere of 40 to 100 ° C.

  In general, “film” refers to a thin flat product whose thickness is extremely small compared to the length and width and whose maximum thickness is arbitrarily limited, and is usually supplied in the form of a roll. (Japanese Industrial Standards JISK6900), “sheet” generally 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, it includes “sheet” and is referred to as “sheet”. In some cases, “film” is included.

According to the present invention, in addition to the refractive scattering caused by the difference in refractive index between the aliphatic polyester resin and the fine powder filler in the resin layer A or the laminate of the resin layer A / resin layer C, the aliphatic polyester resin Refractive scattering due to a difference in refractive index between a compatible thermoplastic resin and a fine powder filler, and further, an aliphatic polyester resin and a void formed around a thermoplastic resin incompatible with the aliphatic polyester resin. Since light reflectivity can be obtained also from refraction scattering due to the difference in refractive index, excellent reflectivity can be obtained even with a thin wall. In addition, SEBS compounds as compatibilizers, glycidyl methacrylate-ethylene copolymers, and mixtures of these are dispersions of thermoplastic resins incompatible with the aliphatic polyester resins in the aliphatic polyester resins. Sexually can be enhanced effectively. In particular, the dispersibility of the thermoplastic resin incompatible with the aliphatic polyester resin in the aliphatic polyester resin heated and melted at a relatively low temperature such as a lactic acid polymer can be extremely effectively dispersed. A reflector having a good product appearance can be produced stably without causing breakage during stretched film formation. Further, by having the B layer, it is possible to impart further reflection performance or strength to the reflector, and the resin layer A or the layer of resin layer A / resin layer C may be insufficient. It can compensate for certain handling properties and heat resistance, and can suppress the generation of wrinkles and undulations during installation and use.
Therefore, the reflector proposed by the present invention can be suitably used as a reflector used as a constituent member of, for example, a liquid crystal display, a lighting fixture, and a lighting signboard.

  Hereinafter, as an example of the embodiment of the present invention, a reflective material used as a constituent member of a liquid crystal display, a lighting fixture, a lighting signboard, etc. will be described, but the use of the reflector of the present invention is limited to such a reflective material. It is not something.

In the present specification, the expression “main component” 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, the content ratio of the main component is not specified, but the main component accounts for 50% by mass or more, preferably 70% by mass or more, particularly preferably 90% by mass or more (including 100%) in the composition. It is normal.
Further, in the present invention, when expressed as “X to Y” (X and Y are arbitrary numbers), unless otherwise specified, “X is preferably greater than X” and “ "Is smaller than Y".

The reflector according to the present embodiment (hereinafter referred to as “the present reflector”) is a laminate having a resin layer A formed from the resin composition A and a B layer made of polystyrene paper or synthetic paper. The resin composition A includes an aliphatic polyester resin, a thermoplastic resin incompatible with the aliphatic polyester resin, a compatibilizer, and a fine powder filler. In the aliphatic polyester resin composition, the compatibilizer is an SEBS compound, a glycidyl methacrylate-ethylene copolymer, or a mixture thereof.
Further, a thermoplastic resin and a compatibilizing agent, which contain the resin layer A formed from the resin composition A, an aliphatic polyester resin and a fine filler, and are incompatible with the aliphatic polyester resin. There may also be mentioned a reflector comprising a laminate having a resin layer C formed from an aliphatic polyester-based resin composition C that does not contain and a B layer made of polystyrene paper or synthetic paper.

[Resin layer A]
(Aliphatic polyester resin)
As the aliphatic polyester resin used in the resin layer A, those chemically synthesized, those synthesized by fermentation by microorganisms, or a mixture thereof can be used.

Chemically synthesized aliphatic polyester resins include aliphatic polyester resins obtained by ring-opening polymerization of lactones such as poly-ε-caprolactone, polyethylene adipate, polyethylene azelate, polyethylene succinate, polybutylene adipate, polybutylene. Aliphatic polyester resins obtained by polymerizing dibasic acids and diols, such as azelate, polybutylene succinate, polybutylene succinate adipate, polytetramethylene succinate, cyclohexanedicarboxylic acid / cyclohexanedimethanol condensate Aliphatic polyester resins obtained by polymerizing hydroxycarboxylic acids such as lactic acid polymers and polyglycols, and a part of ester bonds of the aliphatic polyester resins, for example, 50% or less of all ester bonds are amide bonds. , And ether bond, an aliphatic polyester resin or the like is replaced with the urethane bond or the like.
Examples of the aliphatic polyester resin fermented and synthesized by microorganisms include polyhydroxybutyrate, a copolymer of hydroxybutyrate and hydroxyvalerate, and the like.

  The aliphatic polyester resin used for the resin layer A is preferably an aliphatic polyester resin not containing an aromatic ring. If it is an aliphatic polyester-based resin that does not contain an aromatic ring in the molecular chain, it does not absorb ultraviolet rays, so it is exposed to ultraviolet rays or by receiving ultraviolet rays emitted from a light source such as a liquid crystal display device. The layer does not deteriorate or yellow, and the light reflectivity of the resin layer can be prevented from decreasing with time.

In the resin layer A, light reflectivity can be obtained by refractive scattering at the interface between the aliphatic polyester resin and the fine powder filler. Since this refractive scattering increases as the difference in refractive index between the aliphatic polyester resin and the fine powder filler increases, the difference in refractive index between the aliphatic polyester resin and the fine powder filler increases. In addition, it is preferable to use a resin having a low refractive index.
From this point of view, it is preferable to use an aliphatic polyester resin having a refractive index of less than 1.52 among the aliphatic polyester resins, and particularly a lactic acid polymer (refractive index) having a small refractive index among the aliphatic polyester resins. More preferably, the rate is less than 1.46). In addition, since the lactic acid polymer does not contain an aromatic ring in the molecular chain, it does not absorb ultraviolet rays. Therefore, it is preferable in that the resin layer is not deteriorated or yellowed even when exposed to ultraviolet rays or by ultraviolet rays emitted from a light source such as a liquid crystal display device.

  The lactic acid polymer refers to a homopolymer of D-lactic acid or L-lactic acid or a copolymer thereof. Specifically, poly (D-lactic acid) whose structural unit is D-lactic acid, poly (L-lactic acid) whose structural unit is L-lactic acid, and a copolymer of L-lactic acid and D-lactic acid. There are poly (DL-lactic acid) and mixtures thereof are also included.

The lactic acid polymer can be produced by a known method such as a condensation polymerization method or a ring-opening polymerization method. For example, in the condensation polymerization method, D-lactic acid, L-lactic acid, or a mixture thereof can be directly subjected to dehydration condensation polymerization to obtain a lactic acid polymer having an arbitrary composition. Further, in the ring-opening polymerization method, lactide, which is a cyclic dimer of lactic acid, is subjected to ring-opening polymerization in the presence of a predetermined catalyst while using a polymerization regulator or the like as necessary, and lactic acid having an arbitrary composition. A polymer can be obtained.
The lactide includes L-lactide, which is a dimer of L-lactic acid, D-lactide, which is a dimer of D-lactic acid, and DL-lactide, which is a dimer of D-lactic acid and L-lactic acid, By mixing and polymerizing these as necessary, a lactic acid polymer having an arbitrary composition and crystallinity can be obtained.

Among the lactic acid polymers, the content ratio of D-lactic acid and L-lactic acid is D-lactic acid: L-lactic acid = 100: 0 to 85:15, or D-lactic acid: L-lactic acid = 0: 100. To 15:85 are preferable, and in particular, D-lactic acid: L-lactic acid = 99.5: 0.5 to 95: 5, or D-lactic acid: L-lactic acid = 0.5: 99.5. Those having ˜5: 95 are preferred.
A lactic acid polymer in which the content ratio of D-lactic acid and L-lactic acid is 100: 0 or 0: 100 exhibits very high crystallinity, has a high melting point, and tends to be excellent in heat resistance and mechanical properties. For example, when the film is stretched or heat treated, the resin is crystallized to improve heat resistance and mechanical properties, which is preferable in that respect. On the other hand, a lactic acid-based polymer composed of D-lactic acid and L-lactic acid is preferable in that respect because flexibility is imparted and film forming stability and stretching stability are improved.
Considering the balance between the heat resistance, molding stability and stretching stability of the resulting reflective film, the lactic acid-based polymer used for the resin layer A has a composition ratio of D-lactic acid and L-lactic acid of D-lactic acid. : L-lactic acid = 99.5: 0.5 to 95: 5 or D-lactic acid: L-lactic acid = 0.5: 99.5 to 5:95 is more preferable.

A plurality of types of lactic acid polymers having different content ratios of D-lactic acid and L-lactic acid may be mixed (blended). For example, by blending a homopolymer of D-lactic acid or L-lactic acid and a copolymer thereof, it is possible to balance the difficulty of bleeding and the expression of heat resistance.
When a plurality of types of lactic acid polymers are mixed in this way, the average value of the content ratio of D-lactic acid and L-lactic acid in the plurality of lactic acid polymers may be within the above range. .

  The molecular weight of the lactic acid polymer is preferably a high molecular weight. For example, the weight average molecular weight is preferably 50,000 or more, more preferably 60,000 to 400,000, and particularly preferably 100,000 to 300,000. When the weight average molecular weight of the lactic acid polymer is less than 50,000, the obtained film may be inferior in mechanical properties.

Commercial products can also be used as the aliphatic polyester resin. For example, the Bionore 3000 series from Showa Polymer Co., Ltd. and GS-Pla from Mitsubishi Chemical Corporation can be used.
Examples of the lactic acid-based polymer include the Lacia series from Mitsui Chemicals, the NatureWorks series from NatureWorks, and the like.

(Thermoplastic resin incompatible with aliphatic polyester resin)
Examples of thermoplastic resins that are incompatible with aliphatic polyester resins (hereinafter referred to as “incompatible resins”) include polycarbonate resins, polystyrene resins, acrylic resins, and polyolefin resins. In view of the above, a polyolefin resin is preferable.

Among polyolefin resins, for example, monoolefin polymers such as polyethylene and polypropylene, or copolymers thereof are preferable.
Specifically, low density polyethylene, linear low density polyethylene (for example, ethylene-α-olefin copolymer), medium density polyethylene, polyethylene resin such as high density polyethylene, polybutylene resin, polypropylene, ethylene-propylene copolymer. And polypropylene resins such as poly-4-methylpentene, polybutene, and ethylene-vinyl acetate copolymer. These resins may be used alone or in combination of two or more.
The polyolefin resin includes those produced using a multisite catalyst such as a Ziegler catalyst and those produced using a single site catalyst such as a metallocene catalyst.
Further, a polyolefin-based thermoplastic elastomer obtained by dispersing and compounding ethylene / propylene rubber or the like in these polyolefin-based resins can also be used.

  Considering moldability when forming into a sheet shape, heat resistance when forming into a sheet shape, among the polyolefin resins, linear low density polyethylene resins such as ethylene-α-olefin copolymers, polypropylene, Preferred are polypropylene resins such as ethylene-propylene copolymer, propylene-butene copolymer, ethylene-propylene-butene terpolymer, ethylene-propylene-diene terpolymer, among which polypropylene resin, In particular, polypropylene and an ethylene-propylene copolymer such as an ethylene-propylene random copolymer are preferred.

  Further, from the viewpoint of improving the reflectance, polyolefins having a small refractive index are preferable, and it is particularly preferable to use a polyolefin resin having a refractive index of less than 1.52. For example, a polypropylene resin, a low density polyethylene resin, a polybutylene resin, polymethylpentene, and a mixture or copolymer thereof can be exemplified. Among them, a polypropylene resin having a refractive index of 1.50 or less is used. preferable.

Examples of the polypropylene resin include homopolypropylene resin, random polypropylene resin, block polypropylene resin, and propylene-ethylene rubber.
As a polymerization method for obtaining a polypropylene resin, known methods such as a solvent polymerization method, a bulk polymerization method, and a gas phase polymerization method can be employed. Moreover, as a polymerization catalyst, well-known catalysts, such as a titanium trichloride type catalyst, a magnesium chloride carrying | support catalyst, a metallocene catalyst, are employable, for example.

The melt flow rate (MFR) of the polyolefin resin is not particularly limited, but considering the dispersibility in the aliphatic polyester resin, the MFR (temperature: 190 ° C., load: 2.16 kg) is polyethylene. In the case of a resin, it is preferably about 0.2 to 40 g / 10 min (190 ° C., load 2.16 kg), particularly 1 to 20 g / 10 min, particularly 3 to 10 g / 10 min. In the case of a polypropylene resin, it is preferably 1 to 50 g / 10 min (230 ° C., load 2.16 kg), particularly 3 to 25 g / 10 min, and particularly preferably 5 to 15 g / 10 min.
In addition, in this invention, MFR is measured based on the method prescribed | regulated to ASTMD-1238. However, the measurement means that measurement is performed under each condition shown in parentheses. If the MFR of the polyolefin resin is too small, it is necessary to increase the extrusion temperature at the time of melt molding. As a result, the reflectance is reduced due to yellowing due to oxidation of the polyolefin resin itself and thermal deterioration of the fine particle filler, particularly titanium oxide. May be reduced. On the other hand, if the MFR of the polyolefin-based resin is too large, sheet production by melt molding may become unstable.

  The content ratio of the incompatible resin is preferably 1 to 30% by mass with respect to the total mass of the resin layer A, considering the light reflectivity, mechanical properties, productivity, and the like of the resin layer A. It is more preferably 20% by mass. If the content ratio of the incompatible resin is 1% by mass or more, it is preferable because high light reflectivity and weight reduction of the resin layer A can be realized at the same time. Moreover, if the content rate of incompatible resin is 30 mass% or less, the moldability excellent in the resin layer A can be provided.

(Compatibilizer for resin layer A)
In this reflector, the compatibilizing agent means a compound that can increase the dispersibility of the incompatible resin with respect to the aliphatic polyester resin, and by adding such a compatibilizing agent, incompatibility is achieved. The size of the dispersed phase made of resin can be appropriately controlled.

  As a compatibilizing agent used for the reflector, it is important to use a SEBS (styrene-ethylene-butylene-styrene) -based compound, a glycidyl methacrylate-ethylene-based copolymer, or a mixture thereof. These compatibilizers can effectively enhance the dispersibility of the incompatible resin in the aliphatic polyester resin. In particular, the dispersibility of an incompatible resin in an aliphatic polyester resin that is heated and melted at a relatively low temperature such as a lactic acid polymer can be particularly effectively enhanced.

  Examples of SEBS compounds include styrene-ethylene / butylene / styrene block copolymers, hydrogenated / styrene / ethylene / butylene / styrene block copolymers, and functional group-introduced styrene / ethylene / butylene / styrene block copolymers. In the functional group-introduced styrene-ethylene / butylene-styrene block copolymer, examples of the functional group to be introduced include an acetoxy group, a carboxyl group, a hydroxyl group, a dihydroxyl group, a methacryloyl group, an epoxy group, and an epoxy group. And glycidyl methacrylate groups, maleic anhydride components, butadiene components, styrene-based, acrylic-based, acrylonitrile-styrene-based vinyl monomers and polymers. These functional groups can be introduced alone or in combination of two or more. Of these, butadiene component-introduced styrene-ethylene / butylene-styrene block copolymers and glycidyl methacrylate group-introduced styrene-ethylene / butylene-styrene block copolymers are particularly preferred.

Examples of the glycidyl methacrylate-ethylene copolymer include copolymers and terpolymers composed of at least an epoxy group-containing glycidyl methacrylate and ethylene.
Here, examples of the terpolymer include terpolymers of glycidyl methacrylate containing an epoxy group, ethylene, vinyl acetate, methyl acrylate, and the like. Among them, a terpolymer composed of glycidyl methacrylate containing an epoxy group, ethylene and methyl acrylate is preferable.

The content of the compatibilizing agent is preferably 0.1 to 7% by mass with respect to the total mass of the resin layer A, considering the light reflectivity, mechanical properties, productivity, etc. of the resin layer A. More preferably, it is -5 mass%.
If the content ratio of the compatibilizing agent is 0.1% by mass or more, it is effective for appropriately controlling the size of the dispersed phase of the incompatible resin, and does not cause breakage during stretch film formation. preferable. Moreover, if the content rate of a compatibilizer is 7 mass% or less, the light reflectivity excellent in the resin layer A can be provided. Moreover, since it does not have a bad influence over extrusion and the whole film forming process, it is preferable.

(Fine powder filler of resin layer A)
Examples of the fine powder filler used for the resin layer A include organic fine powder and inorganic fine powder.

  Examples of the organic fine powder include at least one selected from cellulose powders such as wood powder and pulp powder, polymer beads, and polymer hollow particles.

Inorganic fine powders include 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 And at least one selected from kaolin, clay, glass powder, asbestos powder, zeolite, silicate clay, etc., among which one or two selected from the group of calcium carbonate, zinc oxide, barium sulfate and titanium oxide A mixture comprising the above combinations is preferred.
Considering the light reflectivity of the obtained resin layer A, those having a large refractive index difference from the aliphatic polyester resin are preferable. That is, it is preferable that the inorganic fine powder has a large refractive index and that the reference is 1.6 or more. Specifically, it is preferable to use calcium carbonate, barium sulfate, zinc oxide or titanium oxide having a refractive index of 1.6 or more, and titanium oxide having a high refractive index is particularly preferable. However, taking into account long-term durability, barium sulfate which is stable against acids and alkalis is particularly preferable.
In addition, as a fine powder filler, you may use combining the inorganic fine powder illustrated as mentioned above, and organic fine powder. Further, different fine powder fillers can be used in combination, and for example, titanium oxide and other fine powder fillers may be used in combination.

Titanium oxide has a significantly higher refractive index than other inorganic fine powders, and can significantly increase the difference in refractive index with aliphatic polyester resins, so it is less than when other fillers are used. Excellent reflectivity can be obtained with a blending amount. In addition, by using titanium oxide, a highly reflective layer can be obtained even if the resin layer A is thin.
Therefore, it is preferable to use a fine powder filler containing at least titanium oxide. In this case, the amount of titanium oxide is preferably 30% or more of the total mass of the fine powder filler.

  The titanium oxide used in the resin layer A is preferably a crystalline titanium oxide such as anatase type or rutile type, and among them, the refractive index is 2.7 from the viewpoint of a large difference in refractive index from the aliphatic polyester 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, high-purity titanium oxide means titanium oxide having a small light absorption ability for visible light, that is, titanium oxide having a small content of coloring elements such as vanadium, iron, niobium, copper, manganese, etc. Then, a titanium oxide having a niobium content of 500 ppm or less and a vanadium content of 5 ppm or less is referred to as high-purity titanium oxide.
In high purity titanium oxide, it is important that the niobium content is 500 ppm or less, preferably 400 ppm or less. Further, it is important that the vanadium content is 5 ppm or less, preferably 4 ppm or less.

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.

As the fine powder filler, particularly titanium oxide, one having an inert inorganic oxide layer formed from an inert inorganic oxide on the surface is preferable. By coating the surface of titanium oxide with an inert inorganic oxide, the photocatalytic activity of titanium oxide can be suppressed, and deterioration of the resin layer A due to the photocatalytic action of titanium oxide can be prevented.
As the inert inorganic oxide, it is preferable to use at least one selected from the group consisting of silica, alumina, and zirconia. If these inert inorganic oxides are used, the light resistance of the resin layer A can be improved without impairing the high light reflectivity exhibited when titanium oxide is used. Further, it is more preferable to use two or more kinds of inert inorganic oxides in combination, and among them, a combination in which silica is essential is particularly preferable.

The inert inorganic oxide layer preferably occupies 0.5 to 7% by mass, particularly 1 to 3% by mass of the total mass of titanium oxide. If the inert inorganic oxide layer is 0.5% by mass or more, it is easy to maintain high reflectivity, which is preferable. Further, if the inert inorganic oxide layer is 7% by mass or less, the dispersibility in the polyester-based resin is good, and a homogeneous resin layer A is obtained, which is preferable.
The ratio of the inert inorganic oxide layer to the total mass of titanium oxide is the ratio of the total mass of the inert inorganic oxide used for the surface treatment in the total mass of titanium oxide after the surface treatment (in percentage). ).

Furthermore, the inorganic fine powder, particularly titanium oxide, is preferably provided with an organic compound layer formed on the surface thereof from the organic compound in order to improve dispersibility in the aliphatic polyester resin.
The organic compound layer is, for example, a siloxane compound, a silane coupling agent, a polyhydric alcohol, a titanium coupling agent, an alkanolamine or a derivative thereof, and an organic compound such as a higher fatty acid or a metal salt thereof, and the surface of titanium oxide or The inert inorganic oxide layer can be formed by coating the surface thereof. In particular, the coating treatment is preferably represented by at least one organic compound selected from the group consisting of a siloxane compound, a polyhydric alcohol, and a silane coupling agent, and in particular, selected from the group consisting of a polyhydric alcohol and a silane coupling agent. It is preferable to coat with at least one organic compound. These two or more kinds of compounds may be used in combination.
These organic compounds can improve the hydrophobicity, dispersibility, and affinity with the resin of titanium oxide by physical adsorption or chemical reaction with hydroxyl groups on the surface of titanium oxide.

Here, examples of the siloxane compound include dimethyl silicone, methyl hydrogen silicone, and alkyl-modified silicone, and these can be used alone or in combination of two or more.
As the silane coupling agent, for example, alkoxysilanes, chlorosilanes, and polyalkoxyalkylsiloxanes having an alkyl group, alkenyl group, amino group, aryl group, epoxy group, and the like are preferable, and aminosilane coupling agents are more preferable. is there. Specifically, for example, n-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, n-β (aminoethyl) γ-aminopropylmethyltrimethoxysilane, n-β (aminoethyl) γ-aminopropylmethyltrimethoxysilane. Aminosilane coupling agents such as ethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, n-phenyl-γ-aminopropyltrimethoxysilane, dimethyldimethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, Propyltrimethoxysilane, n-butyltrimethoxysilane, n-butyltriethoxysilane, n-butylmethyldimethoxysilane, n-butylmethyldiethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, isobutyl Examples include alkyl silane coupling agents such as rumethyldimethoxysilane, tert-butyltrimethoxysilane, tert-butyltriethoxysilane, tert-butylmethyldimethoxysilane, and tert-butylmethyldiethoxysilane. Two or more types can be used in combination.
Examples of the polyhydric alcohol include trimethylol ethane, trimethylol propane, tripropanol ethane, pentaerythritol, and pentaerythritol. Among these, trimethylol ethane and trimethylol propane are more preferable. These polyhydric alcohol compounds can be used alone or in combination of two or more.

The organic compound layer preferably occupies 0.01 to 5% by mass, particularly 0.05 to 3% by mass, particularly 0.1 to 2% by mass, based on the total mass of titanium oxide.
If the organic compound layer occupies 0.01% by mass or more of the entire titanium oxide, it is possible to prevent titanium oxide from adsorbing water and prevent aggregation of the titanium oxide particles, thereby improving the dispersibility of the titanium oxide. . If the dispersibility of titanium oxide is improved, the area of the interface between the aliphatic polyester resin and titanium oxide is sufficiently secured, so that high light reflectivity can be imparted to the resin layer A. On the other hand, when the organic compound layer is 5% by mass or less of the entire titanium oxide, the lubricity of the titanium oxide particles becomes appropriate, and stable extrusion and film formation become possible.
The ratio that the organic compound layer occupies in the total mass of titanium oxide is determined by the ratio (in percentage) of the total mass of the organic compound used for the surface treatment in the total mass of titanium oxide after the surface treatment.

  When a fine powder filler other than titanium oxide is used, the fine powder filler has a silicon compound, the surface of the fine powder filler, in order to improve dispersibility in the aliphatic polyester resin. It is preferable to use those subjected to surface treatment with a polyhydric alcohol compound, an amine compound, a fatty acid, a fatty acid ester or the like.

The particle size of the fine powder filler is preferably 0.05 μm to 15 μm, more preferably 0.1 μm to 10 μm, and more preferably 0.3 μm to 10 μm. If the particle size of the fine powder filler is 0.05 μm or more, the dispersibility in the aliphatic polyester resin is good, and a homogeneous resin layer A can be obtained. Furthermore, if it is 0.3 micrometer or more, light scattering reflection arises with the roughening of the resin layer A, and the reflection directivity of the resin layer A obtained becomes small, and it is preferable. If the particle size is 15 μm or less, the interface between the aliphatic polyester resin and the fine powder filler is densely formed, and the highly reflective resin layer A can be obtained.
When titanium oxide is used as the fine powder filler, the particle size is preferably 0.1 μm to 1.0 μm, and more preferably 0.2 μm to 0.5 μm. When the particle size of titanium oxide is 0.1 μm or more, the dispersibility in the aliphatic polyester resin is good, and a homogeneous resin layer A can be obtained. Moreover, if the particle size of titanium oxide is 1.0 μm or less, the interface between the aliphatic polyester resin and titanium oxide is densely formed, and high light reflectivity can be imparted to the resin layer A.

The content of the fine powder filler is preferably 10 to 50% by mass with respect to the total mass of the resin layer A, considering the light reflectivity, mechanical properties, productivity, and the like of the resin layer A. More preferably, it is 40 mass%.
If the content of the fine powder filler is 10% by mass or more, a sufficient area of the interface between the aliphatic polyester resin and the fine powder filler can be secured, and the resin layer A has high light reflectivity. Can be granted. Moreover, if content of a fine powder filler is 50 mass% or less, the mechanical property required for the resin layer A is securable.

(Other ingredients)
The resin layer A may contain other components other than these as long as the effects of the aliphatic polyester resin, the incompatible resin, the compatibilizing agent, and the fine powder filler are not impaired. Moreover, you may contain antioxidant, a light stabilizer, a heat stabilizer, a dispersing agent, a ultraviolet absorber, a fluorescent whitening agent, and another additive in the range which does not impair the said effect.

  As the other component, for example, when a lactic acid polymer is used as an aliphatic polyester resin, carbodiimide, which is a hydrolysis inhibitor, is used for the purpose of imparting durability to a higher temperature and higher humidity environment. It is conceivable to add a compound or the like. In particular, in recent years, liquid crystal displays have been used for car navigation systems for automobiles and small in-vehicle TVs as well as PC displays, and those that can withstand high temperatures and high humidity have become necessary. For the purpose of imparting properties, it is preferable to add a hydrolysis inhibitor.

Preferred examples of the carbodiimide compound include those having a basic structure represented by the following general formula (1).
-(N = C = N-R-) n- (1)
In formula (1), n represents an integer of 1 or more, and R represents an organic bond unit. For example, R can be either aliphatic, alicyclic, or aromatic. In addition, n is generally an appropriate integer selected from 1 to 50.

  Specifically, for example, bis (dipropylphenyl) carbodiimide, poly (4,4′-diphenylmethanecarbodiimide), poly (p-phenylenecarbodiimide), poly (m-phenylenecarbodiimide), poly (tolylcarbodiimide), poly ( Examples of the carbodiimide compound include diisopropylphenylenecarbodiimide), poly (methyl-diisopropylphenylenecarbodiimide), poly (triisopropylphenylenecarbodiimide), and the like. These carbodiimide compounds may be used alone or in combination of two or more.

  The addition amount of the carbodiimide compound is preferably 0.1 to 3.0 parts by mass with respect to 100 parts by mass of the aliphatic polyester resin. If the addition amount of the carbodiimide compound is 0.1 parts by mass or more, the hydrolysis resistance improving effect can be sufficiently exhibited. Moreover, if the addition amount of a carbodiimide compound is 3.0 mass parts or less, the resin layer A obtained will be less colored and light reflectivity will not be impaired.

(Porosity)
In order to obtain higher reflection performance, it is preferable to have a void in the resin layer A. If there is a void in the resin layer A, the refractive scattering due to the refractive index difference between the aliphatic polyester resin and the fine filler, the refractive scattering due to the refractive index difference between the incompatible resin and the fine filler, In addition, reflectivity can also be obtained from refractive scattering caused by the difference in refractive index between the aliphatic polyester resin and the void (air), the incompatible resin and the void (air), and the fine powder filler and the void (air).

The porosity of the resin layer A, that is, the ratio of the volume portion of the voids in the resin layer A is 30 to 60%, and preferably 35% or more from the viewpoint of improving the reflectance. If the porosity of the resin layer A is 30% or more, the reflection performance can be sufficiently improved, and if the porosity is 60% or less, the mechanical strength of the resin layer A is ensured, and the resin is produced during production. The layer A is not broken or the durability such as heat resistance is not insufficient at the time of use.
In addition, the porosity in the case of extending | stretching the resin layer A can be substituted for following formula (2), and the porosity of the resin layer A can be calculated | required.
Porosity (%) = {(density of resin layer before stretching−density of resin layer after stretching) / density of resin layer before stretching} × 100 (2)

The voids of the resin layer A can be formed by, for example, stretching a film obtained by melting and forming the resin composition A. This is because the stretching behavior of the aliphatic polyester resin, the fine powder filler and the incompatible resin is different when stretched. That is, if stretching is performed at a stretching temperature suitable for an aliphatic polyester-based resin, the aliphatic polyester-based resin as a matrix is stretched, but the fine powder filler and the incompatible resin tend to remain as they are. The interface between the aliphatic polyester resin and the fine powder filler and the interface between the aliphatic polyester resin and the incompatible resin are peeled to form a void. Therefore, the porosity of the resin layer A can be controlled by adjusting the types and amounts of the fine powder filler and the incompatible resin, the draw ratio, and the like.
Moreover, since a void can be formed in the resin layer A by adding a foaming agent to the resin composition A for foaming, in this case, by adjusting the type and amount of the foaming agent, the resin The porosity of layer A can be controlled.

(Dispersed phase)
In the resin layer A, a dispersed phase composed of an incompatible resin is dispersed in a matrix (matrix) composed of an aliphatic polyester-based resin. At this time, the average diameter of the dispersed phase is 0.1 μm. It is preferably in the range of ˜5 μm, more preferably in the range of 0.5 μm to 3 μm.
When the size of the dispersed phase is 0.1 μm or more, the size of the void formed by stretching is sufficient to reflect light in the visible light region. Further, if the size of the dispersed phase is 5 μm or less, it is possible to sufficiently secure the area of the interface between the void formed by stretching and the aliphatic polyester resin, so that high light reflectivity is imparted to the resin layer A. Is preferable. Further, it is preferable that the size of the dispersed phase is 5 μm or less because the bubbles formed in the periphery thereof become dense and the stretched film forming property is improved together with the mechanical strength.
The size of the dispersed phase can be controlled by the type and amount of the compatibilizing agent, and also by adjusting the extrusion temperature of the extruder and the screw rotation speed of the extruder when the resin composition is melt-formed. Can be controlled.

(Form of resin layer A)
The resin layer A may be a layer formed of a film or a layer formed by forming a thin film of the molten resin composition by extrusion or coating (without forming a film). In the case of a film, the film may be an unstretched film, a uniaxially or biaxially stretched film, but a stretched film obtained by stretching at least 1.1 times in a uniaxial direction, particularly two An axially stretched film is preferred.

(Thickness of resin layer A)
The thickness of the resin layer A is not particularly limited, but is preferably 25 μm to 500 μm, and more preferably 50 μm to 300 μm. If the thickness of the resin layer A is 25 micrometers or more, the light reflectivity from which the reflector of this invention is obtained becomes sufficient, and it is preferable. On the other hand, if the thickness of the resin layer A is 500 μm or less, it is preferable because flexibility necessary for subsequent lamination with the B layer is maintained.

[B layer]
Since the reflector of the present invention has a B layer made of polystyrene paper or synthetic paper, the reflector can be provided with further reflective performance and strength, and handling properties that may be insufficient with only the resin layer A It can compensate for heat resistance and suppress the generation of wrinkles and undulations during installation and use.

  As the polystyrene paper used in the present invention, one obtained by foaming and curing polystyrene with fine bubbles can be used. There are three types of methods for producing polystyrene paper, including polystyrene foam beads, polystyrene paper, and extruded polystyrene. The beaded polystyrene is produced by foaming polystyrene with a hydrocarbon gas such as butane or pentane. Polystyrene paper is not heated and foamed with high-temperature steam, but is added to the raw material melted with heat by adding a gas and a foaming agent for foaming. Let Extruded polystyrene is made by mixing the liquefied raw material, foaming agent and flame retardant well under high temperature and high pressure, and then blowing and curing at a normal pressure and temperature at a stretch to make it into the required size. Disconnect. This continuous manufacturing method is called “extrusion board”. Of these, polystyrene paper is preferred in order to impart handling properties and heat resistance.

The polystyrene paper used in the present invention is preferably subjected to an annealing treatment. Further heat resistance can be imparted to the laminate by annealing the polystyrene paper.
About annealing temperature, 40 degreeC or more is preferable and 60 degreeC or more is more preferable. By setting the annealing temperature to 40 ° C. or higher, the shrinkage rate of polystyrene paper can be suppressed. On the other hand, about an upper limit, 100 degrees C or less is preferable and 90 degrees C or less is more preferable. By setting the annealing temperature to 100 ° C. or lower, the annealing process can be performed while maintaining the shape of the polystyrene paper.
Further, the annealing time is preferably 10 minutes or more, and more preferably 1 hour or more. By performing the annealing treatment for 10 minutes or longer, the shrinkage rate of the polystyrene paper can be suppressed. On the other hand, the upper limit is not particularly limited, but 48 hours or less is preferable.

  The annealing treatment of the polystyrene paper may be performed before or after lamination with the resin layer A, but it is preferable to carry out the annealing treatment before lamination with the resin layer A from the viewpoint of suppressing the shrinkage rate.

  The synthetic paper used in the present invention refers to a paper made from a synthetic polymer substance as a main material and used for conventional paper applications. In other words, synthetic paper is a sheet-like material made of synthetic polymer as the main raw material and has the properties of paper. In addition to the characteristics of natural paper such as opacity and printability, it has features such as moisture resistance and weather resistance. Say what you have.

  The role of the B layer is to provide additional reflection performance and strength, to compensate for handling and heat resistance that may be insufficient with the resin layer A alone, and to prevent wrinkles and undulations during installation and use Therefore, it does not absorb itself, and is itself excellent in heat resistance and firm.

[Resin layer C]
The resin layer C can be formed from a resin composition C that contains an aliphatic polyester-based resin and a fine powder filler and does not contain an incompatible resin and a compatibilizer. By laminating such a resin layer C on the resin layer A, the reflection performance of the reflector can be further enhanced.

The aliphatic polyester-based resin that can be used for the resin layer C is the same as the aliphatic polyester-based resin that can be used for the resin layer A, and preferred types thereof are also the same.
The fine powder filler that can be used for the resin layer C is the same as the fine powder filler that can be used for the resin layer A. For example, examples of the fine powder filler include a mixture of one or a combination of two or more selected from the group consisting of calcium carbonate, zinc oxide, barium sulfate, and titanium oxide. The kind of a preferable fine powder filler is the same as that of the fine powder filler of the resin layer A. In addition, from the viewpoint of durability of the resin layer C, barium sulfate which is stable against acid and alkali is preferable, and from the viewpoint of appearance of the resin layer C, silica and titanium oxide are preferable.

The content of the fine powder filler in the resin layer C is 0.1 to 5% by mass with respect to the mass of the entire resin layer C in consideration of light reflectivity, mechanical properties, productivity, and the like of the resin layer C. It is preferably 0.1 to 3% by mass, and more preferably 0.1 to 1% by mass.
When the reflector of the present invention is incorporated in a liquid crystal display device or the like, when the content of the fine powder filler in the resin layer C is greater than 5% by mass, the luminance tends to be significantly reduced. The reason for this is that when the resin layer C is stretched at least 1.1 times in a uniaxial direction, the interface between the aliphatic polyester resin and the particulate filler is peeled off to form voids in the resin layer C, and gloss This is presumed to be due to the low degree. In addition, when the resin layer C is provided as the outermost layer of the reflector, if the finest filler is not included in the outermost layer, it becomes easy to peel between the resin layer A and the resin layer C. The amount of fine powder filler in the resin layer C is preferably 0.1 to 5% by mass.

(Other ingredients)
The resin layer C may contain a resin other than the aliphatic polyester resin as described above as long as the effects of the aliphatic polyester resin and the fine powder filler are not impaired. In addition, a hydrolysis inhibitor (for example, the above-mentioned carbodiimide), an antioxidant, a light stabilizer, a heat stabilizer, a dispersant, an ultraviolet absorber, a fluorescent whitening agent, and other additives within the range not impairing the above effects. An agent may be contained.

(Form of resin layer C)
The resin layer C may be a layer formed of a film or a layer formed by forming a thin film of the molten resin composition by extrusion or coating (without forming a film). In the case of a film, the film may be an unstretched film, a uniaxially or biaxially stretched film, but a stretched film obtained by stretching at least 1.1 times in a uniaxial direction, particularly two An axially stretched film is preferred.

  When the resin layer C is provided, the thickness ratio between the resin layer A and the resin layer C is preferably 20: 1 to 1: 1, particularly 15: 1 to 5: 1, and particularly preferably 12: 1 to 7: 1. If the thickness ratio of the resin layer A to the resin layer C is greater than 20: 1, the glossiness is sufficient, and good light reflection characteristics are easily obtained, which is preferable. In addition, it is preferable that the thickness ratio of the resin layer A and the resin layer C is smaller than 1: 1 because the reflection characteristic is not adversely affected.

[Laminate]
The reflector of the present invention has a structure in which the resin layers A and B are laminated or a structure further including a resin layer C other than the resin layers A and B. A reflector in which a resin layer A having high reflection performance and a B layer having high heat resistance are laminated, or a reflector in which a laminate of resin layer A and resin C is laminated with a B layer having high heat resistance, Thus, for example, it is possible to satisfy the heat resistance required for a reflector constituting a reflector used in a large liquid crystal television or the like. Specifically, the dimensional stability under an 80 ° C. heating environment can be increased to a higher level.

  The laminated structure and the lamination ratio of the reflector of the present invention are not particularly limited. However, when a preferred laminated structure is exemplified, a layer structure in which layers are laminated in order from the light irradiation side (reflection use surface side). The resin layer A / B layer is preferably a two-type two-layer configuration, or the resin layer A / B layer / the resin layer A is preferably a two-type three-layer configuration. In the present invention, one or more layers other than the resin layers A and B (including different layers) may be further included, and two or more resin layers A and / or two or more layers may be included. B layer may be included.

When the preferable laminated structure in the case of further including the resin layer C other than the resin layer A and the B layer is exemplified, the resin layer A / resin layer C / B layer, resin from the light irradiation side (reflection use surface side) Layer C / resin layer A / B layer three-layer / three-layer structure, or resin layer A / resin layer C / B layer / resin layer C / resin layer A, resin layer C / resin layer A / B layer / resin Three types and five layers of layer A / resin layer C can be considered, but the layers are laminated in the order of resin layer C / resin layer A / B layer / resin layer A / resin layer C from the side irradiated with light (reflection use surface side). It is preferable to do this.
In addition to the resin layer A, the resin layer C, and the B layer, other layers may be provided, and other layers may be interposed between the resin layer A, the resin layer C, and the B layer. For example, an adhesive layer may be interposed between the resin layer A, the resin layer C, and the B layer.

(Thickness)
The thickness of the reflector is not particularly limited, but is usually preferably 300 μm to 3000 μm, and preferably in the range of about 500 μm to 1500 μm in view of handling in practical use. A thickness of the reflector of 300 μm or more is preferable because necessary light reflectivity, strength, and heat resistance can be imparted. On the other hand, if the thickness of this reflector is 3000 micrometers or less, since the handleability at the time of integration and bending workability are maintained, it is preferable.
For example, in the case of a reflector such as a large liquid crystal television, the thickness is preferably 1000 μm to 1300 μm.

(Reflectance)
The reflectivity of the reflector is preferably such that the reflectivity of the surface with respect to light having a wavelength of 550 nm, measured from the reflection use surface side, is 99.0% or more. When such a reflectance is 99.0% or more, the reflector exhibits good reflection characteristics, and a liquid crystal display or the like incorporating the reflector has a fine color without a yellowish screen.

(Shrinkage factor)
A reflective film used in a liquid crystal display such as a liquid crystal display device is required to have a heat resistance of about 80 ° C. That is, when the reflective film is heated at 80 ° C. for 3 hours, the thermal shrinkage of the film is 0% to 2.0% in the direction parallel to the flow direction of the reflective film, and the direction perpendicular to the flow direction of the reflective film. It is important to be 0 to 2.0%. Preferably it is 0 to 1.5%, more preferably 0 to 1.0%. If the thermal shrinkage rate of the reflective film is larger than 2.0%, the reflective film may shrink over time when used at high temperatures. As a result, the size of the reflective film itself is reduced, causing problems such as light leakage, and the reflectance and luminance are reduced.

[Production method]
Next, although an example is given and demonstrated about the manufacturing method of this reflector, it is not limited to the following manufacturing method at all.
First, the manufacturing method of the single layer film which consists of the resin layer A is demonstrated, and the manufacturing method of the 2 layer film provided with the resin layer A and the resin layer C is demonstrated next.

(Manufacturing method of single layer film)
First, an aliphatic polyester resin composition A is prepared by blending an aliphatic polyester resin with a fine powder filler, an incompatible resin, a compatibilizer, and other additives as necessary. Specifically, fine powder fillers, incompatible resins, compatibilizers are added to aliphatic polyester resins, and additives such as antioxidants are added as necessary, and ribbon blenders, tumblers, Henschel mixers are added. Etc., and then kneaded at a temperature equal to or higher than the melting point of the resin using a Banbury mixer, a single-screw or twin-screw extruder, or the like, to obtain the resin composition A. However, the resin composition A can also be obtained by adding a predetermined amount of a fine powder filler, an incompatible resin, a compatibilizing agent, an additive, and the like to the aliphatic polyester-based resin with a separate feeder or the like. In addition, a so-called master batch in which a fine powder filler, an incompatible resin, a compatibilizing agent, an additive and the like are blended in a high concentration in an aliphatic polyester resin in advance is made, and this master batch and the aliphatic polyester resin are prepared. May be mixed to obtain a resin composition A having a desired concentration.

  Next, the resin composition A thus obtained is melted to form a film. For example, the aliphatic polyester resin composition A is supplied to an extruder and heated to a temperature equal to or higher than the melting point of the resin and melted. The conditions such as the extrusion temperature need to be set in consideration of a decrease in molecular weight due to decomposition, but for example, in the case of a lactic acid polymer, the extrusion temperature is preferably in the range of 170 ° C to 230 ° C. . Thereafter, the molten aliphatic polyester-based resin composition is extruded from the slit-shaped discharge port of the T die, and is solidified on a cooling roll to form a cast sheet. At this time, the size of the dispersed phase can be controlled by adjusting the extrusion temperature of the extruder and the screw rotation speed of the extruder.

  The obtained cast sheet is preferably stretched 1.1 times or more in at least one axial direction. By stretching, a void having a fine powder filler and an incompatible resin as a core is formed inside the film, and the light reflectivity of the film can be further enhanced, which is preferable. This is presumably because the effect of refractive scattering generated at these interfaces is increased because a new interface is formed between the aliphatic polyester resin and voids, voids and titanium oxide, and voids and incompatible resin.

  More preferably, the cast sheet is stretched in the biaxial direction. This is because, by biaxial stretching, the porosity is increased and the light reflectivity of the film can be increased. Moreover, if the film is only uniaxially stretched, the formed voids are only in a fibrous form extending in one direction, but by biaxially stretching, the voids are stretched in both the vertical and horizontal directions to form a disk-like form. become. That is, by biaxial stretching, the peeling area at the interface between the aliphatic polyester resin and the fine filler, and between the aliphatic polyester resin and the incompatible resin increases, and the whitening of the film proceeds. The light reflectivity of the film can be increased. Furthermore, since biaxial stretching eliminates anisotropy in the shrinking direction of the film, the heat resistance of the film can be improved, and the mechanical strength of the film can be increased.

  The stretching order of biaxial stretching is not particularly limited. For example, simultaneous biaxial stretching or sequential stretching may be used. After melt film formation using a stretching facility, the film may be stretched to MD by roll stretching, then stretched to TD by tenter stretching, or biaxially stretched by tubular stretching or the like.

  In this case, the stretching ratio is preferably 5 times or more, more preferably 7 times or more as the area ratio. By stretching at an area magnification of 5 times or more, a porosity of 10% or more can be realized, and by stretching to 7 times or more, a porosity of 20% or more can be realized, and 7.5 times or more. A porosity of 30% or more can also be realized by stretching the film.

  The stretching temperature at which the cast sheet is stretched is preferably a temperature within the range of the glass transition temperature (Tg) of the resin to (Tg + 50 ° C.), for example, 50 to 90 ° C. in the case of a lactic acid polymer. Preferably there is. When the stretching temperature is within this range, the film does not break during stretching, and a film with high film forming stability can be obtained. Moreover, since the stretch orientation is high and the porosity can be increased, a film having a high reflectance can be obtained.

  After the stretching, heat treatment may be performed by an appropriate method and conditions as necessary.

(Manufacturing method of the two-layer film provided with the resin layer A and the resin layer C)
Next, the manufacturing method of the 2 layer film provided with the resin layer A and the resin layer C is demonstrated.

  An aliphatic polyester resin composition A is prepared in the same manner as described above. On the other hand, the aliphatic polyester resin composition C produces an aliphatic polyester resin composition C in which a fine powder filler, other additives, and the like are blended with an aliphatic polyester resin as necessary. Specifically, a fine powder filler is added to the aliphatic polyester-based resin, and further an additive such as an antioxidant is added as necessary. After mixing with a ribbon blender, tumbler, Henschel mixer, etc., a Banbury mixer, The resin composition C can be obtained by kneading at a temperature equal to or higher than the melting point of the resin using a single or twin screw extruder or the like. However, the resin composition C can also be obtained by adding a predetermined amount of fine powder filler, additive, and the like to the aliphatic polyester-based resin with separate feeders. In addition, a so-called master batch in which fine powder fillers, additives, etc. are blended in high concentration in an aliphatic polyester resin in advance is prepared, and the master batch and the aliphatic polyester resin are mixed to obtain a desired concentration. It can also be set as the resin composition C.

  Then, the aliphatic polyester-based resin composition A and the aliphatic polyester-based resin composition C are respectively supplied to separate extruders, heated to a temperature equal to or higher than the melting point of each resin, and melted into two types and two layers. The cast film may be formed by merging with a T-die for use, extruding into a laminated form from a slit-like discharge port of the T-die, and closely solidifying on a cooling roll. At this time, the size of the dispersed phase can be controlled by adjusting the extrusion temperature of the extruder and the screw rotation speed of the extruder. Extrusion conditions and the like are the same as in the case of a single layer film. And also about the extending | stretching and heat processing of the obtained cast film, it is the same as that of the case of a single layer film.

(Lamination of resin layer A and B layer, lamination of two-layer film of resin layer A / resin layer C and B layer)
Next, a reflector is manufactured by laminating the resin layer A and the B layer produced as described above, or laminating the two-layer film of the resin layer A / resin layer C and the B layer. As a lamination method, for example, a method of interposing an adhesive (including an adhesive sheet) between the resin layer A and the B layer or between the two-layer film of the resin layer A / resin layer C and the B layer, There are lamination methods such as a method of heat-sealing without using an adhesive, a method of forming a resin layer A made of the resin composition A on the B layer, or a method of forming a two-layer film of resin layer A / resin layer C. However, it is not particularly limited.

  As an example of a laminating method using an adhesive, a resin layer A can be bonded by applying an adhesive such as polyester, polyurethane, or epoxy to the adhesive surface of the B layer. In this 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 2 to 2 on the adhesion side surface of the B layer to which the resin layer A is bonded. An adhesive is applied so as to be about 4 μm. Next, the coated surface is dried and heated with an infrared heater and a hot air heating furnace to maintain the surface of the layer B at a predetermined temperature, and the resin layer A is directly applied to the surface coated with the adhesive of the layer B using a roll laminator. A reflector can be obtained by coating and cooling.

  Also, a hot melt adhesive such as polyester or polyolefin is sprayed on the surface of the resin layer A or B layer by a curtain spray coater, and the resin layer A and B layer are bonded using a roll laminator, and a reflector. You can also get

  Also, as an example of the method of heat-sealing, after the resin layer A and the B layer are superposed, the resin layer A and the B layer are heat-sealed by heating and pressurizing with a heating roll or a press to reflect the heat. You can get a body.

  In addition, the method for laminating the resin layer A and the B layer made of the resin composition A is not particularly limited, and examples thereof include extrusion lamination, sand lamination, and coextrusion.

  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. In addition, the measured value and evaluation which are shown to an Example were performed as shown below. Here, the take-up (flow) direction of the resin layer or the laminate is indicated as MD, and the orthogonal direction thereof is indicated as TD.

(Measurement and evaluation method)
(1) Reflectance An integrating sphere was attached to a spectrophotometer (U-4000, manufactured by Hitachi, Ltd.), and the reflectance with respect to light having a wavelength of 550 nm was measured. Before the measurement, the spectrophotometer was set so that the reflectance of the alumina white plate was 100%.

(2) Thermal contraction rate The reflector was cut into an appropriate size, and a 200 mm wide marked line was put in each of the MD and TD to prepare an evaluation sample. The sample was put in a hot air circulating oven at an evaluation sample temperature of 80 ° C. and held for 3 hours, and the amount of shrinkage of the sample between the marked lines was measured. The ratio of the shrinkage amount to the original size (200 mm) between the sample marked lines before putting in the oven was defined as the thermal shrinkage rate (%).

(3) Heat resistance A reflector was attached to a liquid crystal television by a method of being actually attached to a fixed frame of a reflector incorporated in a backlight of a 32-inch liquid crystal television, and heated at 80 ° C. for 3 hours. Thereafter, the external appearance of the reflector was observed with the naked eye and evaluated based on the following evaluation criteria. Here, ◎ and ○ are practical levels or more.
<Evaluation criteria>
A: No change is observed in the appearance of the reflector after heating.
○: Although a change was visually observed in the reflector after heating, the height was unevenness of less than 1 mm.
X: The unevenness | corrugation of 1 mm or more height was recognized by the reflector after a heating.

(4) Comprehensive evaluation Measure reflectance, shrinkage, and heat resistance. If all physical properties are at practical level, ○, reflectivity, shrinkage, or heat resistance, at least one of the practical levels is not reached. X.

[Example 1]
(Preparation of resin composition A)
A pellet of a lactic acid polymer having a weight average molecular weight of 160,000 (NW3001D: manufactured by Nature Works, L-form content: 98.5%, D-form content: 1.5%), and rutile-type titanium oxide (Ti -Pure R-105: manufactured by DuPont) and polypropylene pellets (Novatech PP FY-4: manufactured by Nippon Polypro Co., Ltd .: MFR = 5 g / 10 min) were mixed at a mass ratio of 33:50:17 to obtain a mixture. Formed. With respect to 100 parts by mass of this mixture, 2.5 parts by mass of a hydrolysis inhibitor (bis (dipropylphenyl) carbodiimide), and a butadiene component-introduced styrene-ethylene-butylene-styrene block copolymer (Dynalon) as a SEBS compound 8630P: manufactured by JSR, butadiene / styrene / ethylene / butylene = 1/14/30/55 mass%) was added and mixed, and then pelletized using a twin-screw extruder, so-called master. A batch was made. The master batch and the lactic acid polymer were mixed at a mass ratio of 60:40 to prepare a resin composition A.

(Preparation of resin layer A)
The obtained resin composition A is supplied to an extruder heated to 200 ° C., and is kneaded at 200 ° C. using the extruder, and then the molten resin composition is extruded into a sheet form from a T die, The film was obtained by cooling and solidification.
The film obtained was roll-stretched 2.3 times to MD at 65 ° C., then biaxially stretched by stretching it tenfold to TD at 84 ° C., and further heat-treated at 140 ° C. to obtain a resin having a thickness of 75 μm. Layer A was obtained.

Next, as a B layer, polystyrene paper having a thickness of 1 mm (manufactured by JSP, foaming ratio: 10 times) was subjected to an annealing treatment for 24 hours in an atmosphere at 80 ° C. Next, a polyolefin hot melt adhesive was applied to the surface of the resin layer A by a curtain spray coater at 6 g / m ² , and then the resin layer A was adhered to both sides of the B layer using a roll laminator. Thereafter, a reflector having a thickness of 1150 mm and a three-layer structure (resin layer A / B layer / resin layer A) was obtained by cooling.
About the obtained reflective film, the reflectance, shrinkage rate, and heat resistance were measured and evaluated. The results are shown in Table 1.

[Example 2]
(Preparation of resin composition A)
Pellets of a lactic acid polymer having a weight average molecular weight of 160,000 (NW3001D, manufactured by Nature Works, L-form content: 98.5%, D-form content: 1.5%), and rutile titanium oxide by a chlorine process (Ti-Pure R-105, manufactured by DuPont) and polypropylene pellets (Novatech PP FY-4, manufactured by Nippon Polypro Co., Ltd., MFR: 5 g / 10 min) were mixed at a mass ratio of 33:50:17. A mixture was formed. With respect to 100 parts by mass of this mixture, 2.5 parts by mass of a hydrolysis inhibitor (bis (dipropylphenyl) carbodiimide), and a butadiene component-introduced styrene-ethylene-butylene-styrene block copolymer (Dynalon) as a SEBS compound 8630P, manufactured by JSR, butadiene / styrene / ethylene / butylene = 1/14/30/55 mass%) was added and mixed, and then pelletized using a twin screw extruder, so-called master A batch was made. This master batch and the lactic acid-based polymer were mixed at a mass ratio of 60:40 to prepare a resin composition A.

(Preparation of resin composition C)
The lactic acid polymer (NW3001D, manufactured by Nature Works) pellets and the rutile titanium oxide (Ti-Pure R-105, manufactured by DuPont) were mixed at a mass ratio of 99: 1 to obtain a mixture. Formed. To 100 parts by mass of this mixture, 3.5 parts by mass of the above-mentioned hydrolysis inhibitor was added and mixed, and then pelletized using a twin screw extruder to prepare a so-called master batch. The master batch and the lactic acid polymer were mixed at a mass ratio of 60:40 to prepare a resin composition C.

(Production of two-layer film)
The resin compositions A and C are respectively supplied to separate extruders A and C heated to 200 ° C., melted and kneaded at 200 ° C. in each extruder, and then merged into a T-die for two types and two layers. Extruded into a sheet shape so as to have a two-layer structure of layer A / resin layer C, and cooled and solidified to form a two-layer film. The obtained two-layer film was stretched 2.3 times at a temperature of 65 ° C., then biaxially stretched by stretching the tenter to TD at 84 ° C., and further heat-treated at 140 ° C. to obtain a thickness of 75 μm. A two-layer film (resin layer A: 68 μm, resin layer C: 7 μm) was obtained.

Next, as a B layer, a 1 mm thick polystyrene paper (manufactured by JSP) was subjected to an annealing treatment for 24 hours in an atmosphere at 80 ° C. Next, a polyolefin hot melt adhesive is applied to the surface of the resin layer A side of the two-layer film by a curtain spray coater at 6 g / m ² , and then using a roll laminator, After the resin layer A side was overlapped and bonded, cooling was performed to obtain a reflector having a thickness of 1150 mm and a five-layer structure (resin layer C / resin layer A / B layer / resin layer A / resin layer C).
About the obtained reflector, the emissivity, shrinkage rate, and heat resistance were measured and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Example 3]
The layer B of Example 1 was bonded in the same manner as in Example 1 except that synthetic paper (500 μm) was used instead of polystyrene paper, and a thickness of 650 μm, a three-layer structure (resin layer A / B layer / resin layer) A reflector of A) was obtained. About the obtained reflector, the same measurement and evaluation as Example 1 were performed. The results are shown in Table 1.

[Comparative Example 1]
The same measurement and evaluation as in Example 1 were performed except that polystyrene paper without annealing treatment was used as the B layer of Example 1. The results are shown in Table 1.

[Comparative Example 2]
Resin composition A was prepared in the same manner as in Example 1, and the obtained resin composition A was supplied to an extruder heated to 200 ° C., kneaded at 200 ° C. using this extruder, and then melted. The resin composition in the state was extruded from a T-die into a sheet and cooled and solidified to obtain a film.
The film obtained was roll-stretched 2.3 times to MD at 65 ° C., then biaxially stretched by stretching it tenfold to TD at 84 ° C., and further heat-treated at 140 ° C. to obtain a resin having a thickness of 75 μm. Layer A was obtained. The obtained resin layer A was measured and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 3]
The same measurement and evaluation as in Example 1 were performed on the synthetic paper (500 μm) alone used in the B layer of Example 3. The results are shown in Table 1.

As in Examples 1 to 3, the resin layer A or the resin layer A / resin layer C is laminated with polystyrene paper or synthetic paper as the B layer, so that the reflectance, shrinkage rate, and heat resistance all satisfy practical levels. I was able to create a body.
On the other hand, by laminating polystyrene paper that was not annealed as in Comparative Example 1, not only the shrinkage ratio was increased, but also the reflectance and heat resistance were not achieved from the practical level. Is preferably subjected to an annealing treatment. Moreover, only the resin layer A or the B layer as in Comparative Examples 2 and 3 could not satisfy the heat resistance and the reflectance, respectively.

  This reflector is particularly useful when used as a reflector for large liquid crystal televisions and the like, particularly in the form of a laminate, but for example, a reflector used for liquid crystal display devices such as liquid crystal displays, lighting fixtures, lighting signs, etc. Useful as.

Claims (12)

A laminate having a resin layer A formed from a resin composition A and a B layer made of polystyrene paper or synthetic paper, the resin composition A comprising an aliphatic polyester resin and the aliphatic polyester resin An aliphatic polyester resin composition comprising a thermoplastic resin that is incompatible with the resin, a compatibilizer that is a SEBS compound or a glycidyl methacrylate-ethylene copolymer, or a mixture thereof, and a fine filler. There,
The shrinkage after heating at 80 ° C. for 3 hours is 0% to 2.0% in the direction parallel to the flow direction of the laminate, and 0% to 2.0% in the direction perpendicular to the flow direction of the laminate. Reflector characterized by.   The reflector according to claim 1, wherein the aliphatic polyester resin is a lactic acid polymer.   The reflector according to claim 1, wherein the thermoplastic resin is a polyolefin-based resin.   The said fine powder filler is a mixture consisting of one kind or a combination of two or more kinds selected from the group of calcium carbonate, zinc oxide, barium sulfate, or titanium oxide. Reflector according to.   The said resin composition A contains a hydrolysis inhibitor further, The reflector in any one of Claims 1-4 characterized by the above-mentioned.   The reflector according to any one of claims 1 to 5, wherein the resin layer A is obtained by stretching at least 1.1 times in a uniaxial direction.   The laminated body further contains an aliphatic polyester resin and a fine powder filler, and an aliphatic polyester resin composition C that does not contain a thermoplastic resin and a compatibilizer that are incompatible with the aliphatic polyester resin. The reflector according to claim 1, comprising a resin layer C formed of   The content of the fine powder filler in the resin layer A is 10 to 50% by mass with respect to the total mass of the resin layer A, and the content of the fine powder filler in the resin layer C is the resin. The reflector according to claim 7, wherein the content is 0.1 to 5% by mass with respect to the total mass of the layer C.   The reflector according to claim 7 or 8, wherein the aliphatic polyester resin of the resin layer C is a lactic acid polymer.   The reflector according to any one of claims 7 to 9, wherein the resin layer A and the resin layer C are obtained by stretching 1.1 times or more in at least a uniaxial direction.   11. The reflector according to claim 1, wherein the polystyrene paper used in the B layer is annealed for 10 minutes or more in an atmosphere of 40 to 100 ° C. 11.   It is used as a structural member of a liquid crystal display, a lighting fixture, or a lighting signboard, The reflector in any one of Claims 1-11 characterized by the above-mentioned.