WO2007072801A1

WO2007072801A1 - Light-reflecting body

Info

Publication number: WO2007072801A1
Application number: PCT/JP2006/325233
Authority: WO
Inventors: Miki Nishida; Kazunari Katsuhara; Takayuki Watanabe; Takashi Hiruma; Jun Takagi
Original assignee: Mitsubishi Plastics, Inc.
Priority date: 2005-12-22
Filing date: 2006-12-19
Publication date: 2007-06-28
Also published as: JP2011150348A; JP4769812B2; TWI356768B; TW200732142A; JPWO2007072801A1

Abstract

Disclosed is a light-reflecting body which enables to reduce generation of noise during opening and closing of a monitor portion when it is processed into a reflector and incorporated in a liquid crystal display of a laptop PC and the like. Specifically disclosed is a light-reflecting body having a structure wherein a layer A containing an aliphatic polyester resin and a finely powdered filler is arranged on one or both sides of a metal plate. This light-reflecting body is characterized in that the surface of the layer A at least on one side has a coefficient of static friction of not more than 0.49 and a coefficient of kinetic friction of not more than 0.42. Consequently, the light-reflecting body enables to reduce generation of noise.

Description

Specification

Light reflector

Technical field

TECHNICAL FIELD [0001] The present invention relates to a light reflector used for a display device such as a personal computer or a television, a lighting fixture, a lighting signboard, and the like, and particularly preferably used as a material of a reflector that constitutes an illumination mechanism built in a liquid crystal display device. It relates to a light reflector.

Background art

[0002] An illumination mechanism (backlight mechanism) built in a liquid crystal display device includes a direct type that directly illuminates a liquid crystal display panel with light from a light source, and a light guide made of acrylic resin or the like. There is a sidelight system (also called an edge light system) that illuminates a liquid crystal display panel through a light plate.

[0003] In a liquid crystal display device, such as a monitor, a small liquid crystal television, and a notebook personal computer, a sidelight system is adopted as the illumination mechanism, and the light from the light source is used. In order to efficiently transmit the light to the light guide plate, a member called “reflector” formed by molding a light reflector formed by stacking a metal and a reflective film is used.

[0004] In recent years, the display performance has been advanced, and in order to improve the performance of the backlight unit by supplying as much light as possible to the liquid crystal, more sophisticated reflection performance is required for the reflector or the reflection film. It has been.

[0005] As a reflective film used for this type of light reflector, polyethylene terephthalate film (hereinafter referred to as silver-deposited PET film) on which silver is vapor-deposited, white polyester film having reflective performance, and the like are used. And the thickness required for light reflectors.

[0006] For example, Patent Document 1 discloses a reflective film that is a white sheet formed by adding titanium oxide to aromatic polyester-based resin. When a light reflector is formed and processed like a reflector, a light reflector in which a reflective film is bonded to a metal plate is used. When molding a light reflector, shape retention is required to retain the shape when bent. Therefore, for example, Patent Document 2 discloses a reflector in which an adhesive layer is provided on a metal and a polyester reflective film is further laminated thereon.

[0007] However, it is difficult for conventional reflectors to realize the high and reflective performance required for recent liquid crystal display devices, and furthermore, molecules of an aromatic polyester-based resin forming a film. Since the aromatic ring contained in the chain absorbs ultraviolet rays, the film deteriorates and yellows due to ultraviolet rays emitted from a light source such as a liquid crystal display device, and the light reflectivity of the reflective film is lowered. I was jealous.

[0008] Therefore, the present inventors have developed a reflective film formed by adding a fine powder filler such as titanium oxide to an aliphatic polyester-based resin, and disclosed this (Patent Document 3).

Patent Document 1: Japanese Patent Application Laid-Open No. 2002-138150

Patent Document 2: JP-A-10-177805

Patent Document 3: WO2004104077

Disclosure of the invention

Problems to be solved by the invention

[0010] The reflective film disclosed in Patent Document 3 not only can realize high reflection performance, but also has a satisfactory force in terms of molding force. When a reflector was formed by laminating it on a liquid crystal display device of a notebook personal computer, noise sometimes occurred when the monitor was opened and closed. Such a problem is a problem that is likely to occur in televisions and other display devices that cannot be powered by the liquid crystal display devices of notebook computers.

[0011] As a result of investigating the cause of the occurrence of this noise, it has been found that there is a possibility that it may be caused by friction between the light guide plate and the reflector (reflector).

[0012] Therefore, the present invention solves the problem by generating noise when the monitor unit is opened and closed, for example, when the monitor unit is mounted on a liquid crystal display device such as a notebook computer using a reflector. It is an object of the present invention to provide a light reflector that can be reduced.

Means for solving the problem

[0013] The present invention is a light reflector comprising a structure in which an A layer containing an aliphatic polyester-based resin and a fine powder filler is laminated on one side or both sides of a metal plate. , A light reflector is proposed in which the coefficient of static friction of at least one surface of the light reflector is 0.49 or less and the coefficient of dynamic friction is 0.42 or less.

[0014] The above-mentioned "single-side surface" may be the surface of the A layer on one side, or may be the surface of another layer laminated on the A layer. For example, it may be the surface of the B layer in the case where a B layer formed from a thermosetting resin or ionizing radiation curable resin is laminated on at least the surface side of the A layer on one side.

[0015] The light reflector of the present invention can obtain excellent light reflectivity by refractive scattering due to the refractive index difference between the aliphatic polyester-based resin and the fine powder filler constituting the A layer. For example, a light reflector can be processed into a reflector by forming a surface of at least one side with a static friction coefficient of 0.49 or less and a dynamic friction coefficient of 0.42 or less. When incorporated in a liquid crystal display device of a personal computer, noise generation when the monitor is opened and closed can be reduced. This kind of noise generation problem can also occur when some kind of operation is performed on a display device such as a TV or desktop PC that can be moved with force by opening and closing the monitor of a notebook computer, as well as lighting equipment and lighting signs. This is a matter of concern. Therefore, the light reflector of the present invention can be suitably used as a reflection plate incorporated in, for example, a display device such as a personal computer or a television, a lighting fixture, a lighting signboard, etc., and particularly constitutes a knock light device incorporated in a liquid crystal display device. The reflector can be used particularly preferably as a constituent member.

[0016] The A layer constituting the light reflector of the present invention may be in the form of a sheet or film. However, the present invention does not distinguish between a sheet and a film. In general, “sheet” is a thin product as defined by JIS, and generally its thickness is small and flat instead of length and width, and “film” is generally length and width. It is a thin flat product with a maximum thickness that is arbitrarily limited compared to, and is usually supplied in the form of a roll (Japanese Industrial Standard JISK6900). However, in the present invention in which the boundary between the sheet and the film is not fixed, it is not necessary to distinguish the two in terms of the wording. Therefore, in the present invention, even when the term “film” is used, the term “sheet” is included. Even when referring to it, it shall include “film”.

[0017] In addition, when expressed as "main component" in this specification, unless otherwise stated It includes the intention to allow other components to be contained within a range that does not interfere with the function of the main component. Although the content ratio of the main component is not particularly specified, the main component (in the case where two or more components are main components, the total amount thereof) is usually 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%).

[0018] Further, in the present specification, when "X to Y" (X and Υ are arbitrary numbers) is described, with the meaning of "X or more and Υ or less" unless otherwise specified, "preferably Includes the meaning of “greater than X and less than Υ”.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an example of an embodiment of the present invention will be described in detail.

[0020] [First embodiment]

The light reflector according to the present embodiment (“the present light reflector” t) is a layer A mainly composed of aliphatic polyester-based resin and fine powder filler on one side or both sides of the metal plate. And a light reflector formed so that the static friction coefficient and the dynamic friction coefficient of the surface of the A layer on at least one side are in a predetermined range.

[0021] It should be noted that the A layer may be provided on one side or both sides of the metal plate. Therefore, for example, the C layer may be interposed between the metal plate and the A layer. So, in the following, following the A layer and the metal plate

The C layer will be described, and then the configuration, characteristics, manufacturing method, etc. of the light reflector will be described.

[0022] <A layer>

The A layer is a layer that mainly imparts light reflectivity, and is a layer that also has a resin composition A force containing at least an aliphatic polyester-based resin and a fine powder filler as main components. For example, it can be formed by forming it into a film and laminating it on a metal plate, or forming it as a thin film layer on the metal plate.

[0023] (A-layer aliphatic polyester-based resin)

Since the aliphatic polyester resin does not contain an aromatic ring in the molecular chain, it is possible to prevent ultraviolet absorption by using the aliphatic polyester resin as the base resin of the A layer. Therefore, exposure to ultraviolet light or liquid crystal display It is possible to suppress a decrease in light reflectivity over time, which is not deteriorated or yellowed by receiving ultraviolet rays emitted from a light source such as an apparatus.

[0024] As the aliphatic polyester-based resin, chemically synthesized, fermented and synthesized by microorganisms, or a mixture thereof can be used.

[0025] Examples of the chemically synthesized aliphatic polyester-based resin include poly ε-strength prolatatam obtained by ring-opening polymerization of rataton, polyethylene adipate obtained by polymerizing dibasic acid and diol, polyethylene Azelate, polytetramethylene succinate, cyclohexanedicarboxylic acid Ζ cyclohexanedimethanol condensation polymer, lactic acid polymer obtained by polymerizing hydroxycarboxylic acid, polyglycol, etc. Examples include aliphatic polyesters in which a part of the ester bond of the aliphatic polyester is replaced with, for example, 50% or less of the ester bond by an amide bond, an ether bond, a urethane bond, or the like.

[0026] Examples of the aliphatic polyester-based coconut resin fermented and synthesized by microorganisms include polyhydroxybutyrate, a copolymer of hydroxybutyrate and hydroxyvalerate, and the like.

[0027] Among the above-described aliphatic polyester-based resins, it is preferable to use an aliphatic polyester-based resin having a refractive index (n) of less than 1.52 as the base resin of the cocoon layer. That is, if a layer comprising an aliphatic polyester-based resin having a refractive index (n) of less than 1.52 and a fine powder filler is provided, refractive scattering at the interface between the base resin and the fine powder filler is performed. The light reflectivity can be realized by using. Since the refractive scattering effect increases as the refractive index of the base resin and the fine filler increases, the base resin preferably has a low refractive index. A lactic acid polymer that is less than 46 (generally around 1.45) is the most suitable example.

[0028] Examples of the lactic acid-based polymer include homopolymers of D-lactic acid or L-lactic acid or copolymers thereof. Specifically, poly (D lactic acid) whose structural unit is D-lactic acid, poly (L lactic acid) whose structural unit is lactic acid, and poly (DL lactic acid) which is a copolymer of L lactic acid and D lactic acid Or a mixture thereof.

[0029] As described above, lactic acid includes two types of optical isomers, that is, L lactic acid and D lactic acid, and the crystallinity differs depending on the ratio of these two types of structural units. For example, in the case of a random copolymer with a ratio of L lactic acid and D lactic acid of about 80: 20-20: 80, the glass transition point is 60 ° C where the crystallinity is low. It becomes a transparent, completely amorphous polymer that softens in the vicinity. On the other hand, a random copolymer having a ratio of L lactic acid and D lactic acid of about 100: 0 to 80:20, or about 20:80 to 0: 100, has a glass transition point similar to the copolymer described above. Although it is about ° C, it has high crystallinity.

[0030] In this light reflector, the DL ratio in the lactic acid polymer, that is, 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 is preferred! /. More preferably, 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.

[0031] 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, and has a high melting point and excellent heat resistance and mechanical properties. Tend. That is, 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 molding stability and stretching stability are improved. Considering the balance between heat resistance, molding stability and stretch stability of the resulting light reflector, the composition ratio of D lactic acid and L lactic acid is: D lactate: L lactate = 99.5: 0.5 to 95: 5 A certain force, or D lactic acid: L lactic acid = 0.5: 99. 5 to 5:95 is more preferable! /.

[0032] The lactic acid-based 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. In addition, 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 using a polymerization regulator or the like, if necessary. A system polymer can be obtained.

[0033] 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 accordingly, a lactic acid polymer having an arbitrary composition and crystallinity can be obtained.

[0034] Note that lactic acid polymers having different copolymerization ratios of D lactic acid and L lactic acid may be blended. Yes. In this case, it is preferable to adjust so that the average value of the copolymerization ratios of D lactic acid and L lactic acid of a plurality of lactic acid polymers falls within the range of the DL ratio.

[0035] Further, as the lactic acid-based polymer, a copolymer of lactic acid and another hydroxycarboxylic acid can be used. At this time, the “other hydroxycarboxylic acid units” to be copolymerized include glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxyn-butyric acid, 2-hydroxy-3,3-dimethylbutyric acid, 2-hydroxy-3 methyl. Examples include bifunctional aliphatic hydroxycarboxylic acids such as butyric acid, 2-methyl lactic acid, and 2-hydroxycaproic acid, and ratatones such as force prolatatanes, butyrolatatanes, and valerolatatanes.

[0036] Furthermore, the lactic acid-based polymer may be a non-aliphatic carboxylic acid such as terephthalic acid and a non-aliphatic diol such as an ethylene oxide adduct of Z or bisphenol A as a small amount copolymerization component. , Lactic acid and Z or hydroxycarboxylic acid other than lactic acid may be contained.

[0037] The molecular weight of the lactic acid-based polymer is preferably a high molecular weight. For example, the weight average molecular weight is preferably 10,000 or more, more preferably 60,000 to 400,000, and even more preferably 100,000. It is particularly preferred to be ~ 300,000. If the weight average molecular weight of the lactic acid polymer is less than 50,000, the mechanical properties may be inferior.

[0038] (A-layer fine powder filler)

Examples of the fine powder filler in the A layer include organic fine powder and inorganic fine powder.

[0039] As the organic fine powder, it is preferable to use at least one selected from cellulose-based powders such as wood powder and pulp powder, polymer beads, polymer hollow particles and the like.

[0040] Examples of the inorganic fine powder 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, It is preferable to use at least one selected from silica, my strength, talc, kaolin, clay, glass powder, asbestos powder, zeolite, white clay, etc.

[0041] Among these, fine powder fillers that have a large refractive index difference from aliphatic polyester-based rosins and are capable of obtaining excellent reflection performance are preferred. From this viewpoint, inorganic fine powder having a large refractive index is used. It is preferable. Specifically, an acid having a refractive index of 2.5 or more, even though calcium carbonate, barium sulfate, acid titanium or acid zinc is preferred. Tan is particularly preferred. Considering long-term durability, barium sulfate that is stable against acids and alkalis is also preferred.

[0042] Titanium oxide has a significantly higher refractive index difference than that of other aliphatic fine powders compared to aliphatic polyester-based resin, so it is more than when other fillers are used. With a small blending amount, high reflection performance and low light transmission can be imparted to the reflector. Further, by using titanium oxide, the present light reflector having high reflection performance, low V, and light transmittance can be obtained even if the light reflector is thin.

[0043] As the acid titanium, a crystalline acid titanium such as anatase type rutile type is preferred. From the viewpoint of increasing the refractive index difference from the base resin, it is preferable to use an acid titanium with a refractive index of 2.7 or higher. More preferably. The greater the difference in refractive index, the greater the refractive and scattering effect of light at the interface between the base resin and the titanium oxide titanium, and the light reflectivity can be easily imparted.

[0044] Further, in order to provide high light reflectivity, it is desirable that the titanium oxide has a small light absorption ability with respect to visible light. In order to reduce the light-absorbing ability of titanium oxide, it is preferable that the amount of coloring elements contained in titanium oxide is small. From this viewpoint, titanium oxide having a niobium content of 50 Oppm or less is used. I like it!

[0045] Titanium oxide produced by the chlorine method process has high purity. According to this production method, titanium oxide having a-job content of 500 ppm or less can be obtained.

[0046] In the chlorine method process, rutile ore containing titanium oxide as a main component is reacted with chlorine gas at a high temperature of about 1000 ° C to form tetra-salt-titanium. High purity titanium oxide can be obtained by burning with.

[0047] The titanium oxide used as the fine powder filler is preferably one whose surface is coated with an inert inorganic oxide. By coating the surface of titanium oxide with an inert inorganic oxide, it is possible to suppress the photocatalytic activity of titanium oxide and improve light resistance (durability when irradiated with light). it can.

[0048] Examples of the inert inorganic oxide used for the coating treatment of acid titanium include alumina, silica and It is preferably at least one selected from the group power consisting of zircoyu. By coating with these inert inorganic oxides, it is possible to improve the light resistance without impairing the high reflection performance obtained with titanium oxide. In addition, it is more preferable to use a combination of two or more of the above-mentioned inert inorganic oxides in combination, and the combined force of silica and other inert inorganic oxides (for example, alumina and zircoure) is obtained. It is particularly preferred to cover with a mixture.

[0049] In order to improve the dispersibility in the base resin, at least one inorganic compound selected from the group consisting of a siloxane compound, a silane coupling agent, a polyol, Polyethylene glycol, etc. Surface treatment with at least one selected organic compound.

[0050] The average particle diameter of the titanium oxide to be added is preferably 0.2 / ζ πι to 0.5 m, more preferably 0.2 μm.

[0051] If the average particle diameter of titanium oxide is 0.1 µm or more, the dispersibility in the aliphatic polyester-based resin is good and the titanium oxide can be formed uniformly. Further, if the average particle size is 1 m or less, the interface between the aliphatic polyester-based rosin and the acid-titanium is more densely formed, so that excellent light reflectivity can be imparted.

[0052] Even when a fine powder filler other than titanium oxide is used, a silicon compound, a polyhydric alcohol compound, an amine compound, a fatty acid, a fatty acid ester may be used in order to improve dispersibility in the base resin. You may make it surface-treat by.

[0053] The fine powder filler other than titanium oxide has an average particle size of 0.05 π! Even though it is preferable to be ~ 15 m, 0 .: L m or more or 10 m or less is more preferable. If the average particle size of the fine powder filler is 0.05 m or more, diffused reflection occurs with the roughening of the surface, resulting in a smaller reflection directivity. In addition, if the average particle size of the fine powder filler is 15 m or less, the interface between the aliphatic polyester-based resin and the fine powder filler is more densely formed, so that excellent light reflectivity can be imparted. it can.

[0054] Titanium oxide or a fine powder filler other than titanium oxide is preferably mixed and dispersed in an aliphatic polyester-based resin.

[0055] The content of the fine powder filler is determined in consideration of light reflectivity, mechanical properties, productivity, etc. It is more preferably 10 to 55% by mass of the composition A, but it is more preferably 20 to 45% by mass.

[0056] If the content of the fine powder filler is 10% by mass or more, the area of the interface between the base resin and the fine powder filler can be sufficiently secured, so that even higher light reflectivity is imparted. can do. Further, if the content of the fine powder filler is 60% by mass or less, the mechanical properties necessary for the film can be ensured.

[0057] (Other components in layer A)

The resin composition A does not interfere with the functions of the aliphatic polyester resin and fine powder filler! / And may contain other additives within the range. For example, hydrolysis inhibitors, antioxidation agents, light stabilizers, heat stabilizers, lubricants, dispersants, UV absorbers, white pigments, fluorescent brighteners, and other additives can be added. .

[0058] (Internal void)

The A layer may have a void. By having the air gap, the reflectance can be further increased.

[0059] The porosity of the A layer (the ratio of voids in the A layer) is preferably 50% or less, particularly preferably in the range of 5 to 50%. Among these, from the viewpoint of improving the reflectance, the porosity is preferably 20% or more, and particularly preferably 30% or more. When the porosity exceeds 50%, it is assumed that the mechanical strength is lowered or the durability such as heat resistance is insufficient during use.

Such voids in the A layer can be formed by adding a fine powder filler to the resin composition A to form a film and stretching the film.

[0060] In the case of using niobium titanium oxide having a niobium content of 500 ppm or less as the fine powder filler, it is sufficiently high even if the porosity existing inside is low or there is no void. Light reflectivity can be obtained, and the following effects can also be obtained. That is, when titanium oxide containing 500 ppm or less of niobium is used, the amount of filler used can be reduced, and as a result, the number of voids formed by stretching is reduced, which is high. It is also possible to improve the mechanical properties while maintaining the reflective performance. In addition, dimensional stability can be improved by reducing the number of voids present inside. Furthermore, even thin walls are expensive Reflective performance can be ensured, and it is particularly suitable as a light reflector constituting a knocklight device for a small and thin liquid crystal display such as a notebook personal computer or a mobile phone.

[0061] (Static friction coefficient and dynamic friction coefficient of surface of layer A)

The A layer composed of the resin composition A having such a composition forms the film of the resin composition A force and is laminated on a metal plate, or formed as a thin film layer on the metal plate. However, in this light reflector, it is important that the static friction coefficient and the dynamic friction coefficient of the surface of the layer A are adjusted within a predetermined range.

[0062] That is, at least the surface of the A layer on one side (preferably the surface of the A layer on both sides) has a static friction coefficient of 0.49 or less and a dynamic friction coefficient of 0.42 or less. is important.

[0063] If the static friction coefficient of the surface of the layer A on at least one side is 0.49 or less and the dynamic friction coefficient is 0.42 or less, for example, the light reflector is processed into a reflector so that a notebook type bath When incorporated in a liquid crystal display device, the generation of noise when the monitor is opened and closed can be effectively reduced.

[0064] From this viewpoint, it is preferable that the static friction coefficient of at least the surface of the A layer on one side (preferably the surface of the A layer on both sides) is 0.46 or less. The coefficient of dynamic friction is preferably 0.36 or less.

[0065] In order to adjust the static friction coefficient and the dynamic friction coefficient of the surface of the layer A to the predetermined ranges, a friction modifier is kneaded and mixed with the layer A, or a coating liquid containing the friction modifier is applied to the surface of the layer A. It can be adjusted from what you do.

[0066] Examples of the friction modifier include a surfactant having both a hydrophilic part and a lipophilic part in its molecule, or a substance mainly composed of this surfactant. Such surfactants are broadly classified into cationic, anionic, zwitterionic, and nonionic types, and are preferably used or divided according to the processing method and application.

[0067] Of these, the ionic surfactants or those containing the same as the main component have versatility and are preferable in terms of the balance between effect and economic efficiency. Typically, 1) fatty acid salts, 2) higher alcohol sulfates, 3) liquid fatty oil sulfates, 4) aliphatic amines and 5) Aliphatic alcohol phosphates, 6) Dibasic fatty acid ester salts, 7) Fatty acid amide sulfonates, 8) Alkylaryl sulfonates, 9) Naphthalene with formalin condensation Examples thereof include sulfonates.

[0068] In addition, examples of cationic systems that are weak against heat and high in cost but have high antistatic properties include 1) aliphatic amine salts, 2) quaternary ammonium salts, and 3) alkylpyridium salts. It is done.

[0069] In addition, amphoteric ion systems with slightly improved heat resistance, which is a weak point of the ion system, are as follows: 1) imidazoline derivatives, 2) carboxylic acid ammoniums, 3) sulfate ester ammoniums. 4) Phosphoric ester ammoniums, 5) Sulfonic acid ammoniums, and the like.

Note that the friction modifier may contain silicone oil or rosin containing silicone.

[0070] This friction modifier is prepared by immersing the surface of the layer A in a liquid containing the friction modifier, spraying a liquid containing the friction modifier on the surface of the layer A, or pre-coating the friction modifier with a resin composition. It can be kneaded into product A and transferred to the surface of layer A.

[0071] When the friction modifier is kneaded and mixed with the resin composition A, the content of the friction modifier in the A layer is preferably 0.001 to 2% by mass. 0.01 to L: 5% by mass More preferably. Within the range of 0.001 to 2% by mass, it is possible to obtain a light reflector having good slipperiness without impairing the reflection performance.

[0072] <Metal plate>

The metal plate that constitutes the light reflector is preferably selected according to, for example, the type of liquid crystal display device that uses the reflector. Examples include a stainless steel plate having a thickness of ˜0.4 mm, an aluminum alloy having a thickness of 0.1 to 0.6 mm, or a brass plate having a thickness of 0.2 to 0.4 mm. However, it is not limited to these.

[0073] The surface on which the light reflecting plate is laminated is preferably subjected to a surface treatment in order to improve the adhesion and adhesion of the light reflecting plate.

[0074] Examples of the surface treatment include chemical treatment, discharge treatment, and electromagnetic wave irradiation treatment.

Examples of the chemical treatment include silane coupling agent treatment, acid treatment, alkali treatment, ozone treatment, ion treatment and the like. Examples of the discharge treatment include treatment methods such as corona discharge treatment, glow discharge treatment, arc discharge treatment, and low temperature plasma treatment. Examples of the electromagnetic wave irradiation treatment include ultraviolet ray treatment, X-ray treatment, gamma ray treatment, and laser treatment. In particular, the silane coupling agent treatment is particularly effective in improving the adhesion between inorganic substances (metal plates) and organic substances (fine powder-containing polyester layer), and corona discharge treatment is effective for adhesion under atmospheric pressure. Can be improved.

[0075] <Elbow>

In this light reflector, for example, a resin composition A force film is formed, and the film is heat-sealed to a metal plate, or the resin composition A is melted and extruded onto the metal plate to form a film. The A layer can be directly laminated on the metal plate, but the C layer may be interposed between the A layer and the metal plate.

[0076] The C layer can be formed with a film force made of, for example, a polyester-based resin.

Specific examples of the film made of polyester-based resin include, for example, a film made of aromatic polyester-based resin, aliphatic polyester-based resin, or copolymerized polyester-based resin. If a film made of strong polyester-based resin is used as the C layer and interposed between the A layer and the metal plate, it is laminated with the metal plate at a low temperature without impairing the light reflectivity function of the A layer. be able to.

[0077] Examples of the aromatic polyester-based resin include polyethylene terephthalate, polyethylene isophthalate, polybutylene terephthalate, poly (1,4-cyclohexylenedimethylene) terephthalate, polyethylene 2, 6 naphthalene dicarboxylate, polyethylene naphthalate. An aromatic polyester-based resin such as phthalate can be mentioned.

[0078] Examples of the aliphatic polyester-based resin include the chemically synthesized aliphatic polyester-based resin exemplified above, the aliphatic polyester-based resin synthesized by fermentation using microorganisms, and mixtures thereof. Can be used.

[0079] Examples of the copolyester-based resin include those composed of one or more acid components and one or more polyhydric alcohol components of an ester repeating unit force. One or two or more acid components and one or two or more polyhydric alcohol components.

[0080] As the repeating unit of the ester in the copolyester resin, phthalic acid, One or two or more acids selected from among taric acid, terephthalic acid, naphthalene acid, oxalic acid, succinic acid, dartaric acid, adipic acid, pimelic acid, spellic acid, azelaic acid, sebacic acid, dodecadioic acid, etc. Selected from ethylene glycol, diethylene glycol, triethylene glycol, 1,4 cyclohexane dimethanol, 1,2 propylene glycol, 1,4 butanediol, 1,5 pentadiol, 1,6 hexadiol, etc. One or two or more types of copolyester-based resin having a polyhydric alcohol power can be mentioned.

[0081] Among them, preferred are isophthalic acid and terephthalic acid as the acid component, and a copolymer containing ethylene glycol and 1,4-cyclohexanedimethanol as the polyhydric alcohol.

[0082] The aromatic polyester-based resin, the aliphatic polyester-based resin or the copolymerized polyester-based resin as the base resin of the C layer is not limited to those exemplified above.

Among these, polyethylene terephthalate, polyethylene isophthalate, and lactic acid polymers are particularly preferable.

[0083] The polyester resin constituting the C layer is preferably a resin having a melting point in the range of 80 ° C to 270 ° C, and is preferably in the range of 150 ° C to 250 ° C. More preferred. If the melting point is 80 ° C to 270 ° C, sufficient adhesion to the metal plate can be secured without using an adhesive, and the effect of heat when laminating on the metal plate can be suppressed, and light It is possible to prevent the reflection performance of the reflector from deteriorating. The melting point here is a value measured by differential scanning calorimetry (DSC).

[0084] The heat of fusion of the polyester resin constituting the C layer is preferably smaller than the heat of fusion of the aliphatic polyester resin constituting the A layer. If the heat of fusion of the polyester-based resin of the C layer is low, the A layer and the metal plate can be laminated at a low temperature. By interposing the C layer between the A layer and the metal plate, the adhesion of each layer The force can be improved and the mechanical strength of the light reflector can be improved.

[0085] For example, when a lactic acid-based polymer is used as the polyester-based resin constituting the C layer, the heat of fusion of the lactic acid-based polymer constituting the C layer is the aliphatic polyester-based resin constituting the A layer. It is preferable that it is smaller than the heat of fusion of fat. Lactic acid polymers have a melting point in the range of 80 ° C to 270 ° C regardless of the composition ratio of D-lactic acid and L-lactic acid. Therefore, the lactic acid polymer has a desired composition ratio of D-lactic acid and L-lactic acid. System polymers can be used. Among these, a lactic acid polymer that is a copolymer is more preferable because the lactic acid polymer has low crystallinity and low heat of fusion. The heat of fusion here is a value measured by differential scanning calorimetry (DSC).

[0086] (Other components in layer C)

The C layer may contain components other than those described above as long as the effects of the polyester-based resin are not impaired. For example, fine powder fillers, lubricants, hydrolysis inhibitors, anti-oxidation agents, light stabilizers, heat stabilizers, dispersants, UV absorbers, white pigments, optical brighteners, and other additives. Contain, okay.

[0087] For example, if the C layer contains the fine powder filler described in the A layer, also from the refractive scattering due to the refractive index difference between the polyester-based resin constituting the C layer and the fine powder filler. Reflective performance can be obtained, and the reflective performance of the light reflector can be further improved.

[0088] If the C layer contains a lubricant, the adhesion between the A layer, the C layer, and the C layer and the metal plate can be further improved.

[0089] As the lubricant, so-called internal lubricants and external lubricants can be used. Examples thereof include internal lubricants such as fatty acid lubricants, alcohol lubricants, aliphatic amide lubricants and ester lubricants, and external lubricants such as acrylic lubricants and hydrocarbon lubricants, preferably acrylic lubricants and hydrocarbon lubricants. A lubricant may be added. Further, the exemplified lubricants may be used in any combination.

[0090] The content of the lubricant is from 0.05 to 100 parts by mass of the aliphatic polyester-based resin constituting the C layer. More preferably, it is at most part by mass.

[0091] (Configuration of layer C)

The C layer can also be formed as a layer having two or more different types of multi-layer constituent forces. By making the C layer a multi-layer structure, the adhesion and lamination conditions between the A layer and the C layer and the adhesion and lamination conditions between the C layer and the metal plate can be adjusted appropriately, and the light reflector Dense as a whole It is possible to design the wearability, reflection performance, mechanical strength, and the like within a preferable range.

[0092] The C layer may have voids inside. If it has air gaps, it is possible to obtain reflection performance due to the refractive scattering power due to the refractive index difference between the polyester-based resin constituting the C layer and the air gap (air), further improving the reflection performance of the light reflector. Can be made.

[0093] <Configuration of light reflector>

As described above, the light reflector can be configured by directly laminating the A layer on one or both surfaces of the metal plate, or by interposing the C layer between the A layer and the metal plate. You can also. Thus, for example, a two-layer configuration consisting of A layer Z metal plate, A layer Z metal plate ZA layer, or A layer ZC layer three layer configuration consisting of Z metal plate, A layer ZC layer Z metal plate consisting of ZA layer It can be formed as a four-layer structure, A layer ZC layer Z metal plate ZC layer ZA layer, or more multilayer structure. Further, it can be formed as a laminated structure including layers other than the A layer and the C layer.

In such a configuration, the thickness of each A layer is preferably 50 μm to 250 μm, and more preferably 50 m to: LOO / z m.

The thickness of the C layer is preferably 5 μm to 100 μm, more preferably 5 μm to 20 μm.

[0095] The thickness of the entire light reflector varies depending on the desired application and the metal plate to be used, and is not particularly limited. However, in view of the use of a reflector incorporated in a small and thin display device, etc. 0.05 mm: Even though it is preferable to use Lmm, 0.1 mm to 0.7 mm is more preferable.

[0096] <Characteristics of light reflector>

(Reflectance)

In the present light reflecting plate, the reflectance measured from the reflective use surface side with respect to light having a wavelength of 550 nm is preferably 95% or more, more preferably 97% or more. If the reflectance is 95% or more, good reflection characteristics are exhibited and sufficient brightness can be given to a screen such as a liquid crystal display.

[0097] (Thermal characteristics)

Regarding the thermal characteristics of the A layer and C layer constituting the light reflector, it is preferable that the thermal shrinkage rate when it is left at 120 ° C. for 5 minutes is 10% or less, more preferably 5% or less. preferable. [0098] For example, when it is incorporated as a reflector for a car navigation system for an automobile or a small vehicle-mounted television, in view of the temperature inside the car under the hot sun in summer, heat resistance and dimensional stability under a heating environment are required. The Therefore, if the thermal contraction rate when left at 120 ° C for 5 minutes as described above is 10% or less, dimensional stability that can maintain the flatness of the A layer and the C layer is secured, and the metal plate is peeled off. This is preferable because it is not necessary.

[0099] <Application>

As described above, the present light reflector has both high reflection performance, high heat resistance, and is suitable as a reflector for displays such as a television, a lighting fixture, and a lighting signboard. Alternatively, it can be suitably used as a member called a reflector that is formed by molding a light reflector.

[0100] <Production method>

Hereinafter, although the example of the manufacturing method of this light reflector is demonstrated, the manufacturing method of the light reflector of this invention is not limited to the following manufacturing method.

[0101] In the present light reflecting plate, the resin composition A is melted and directly formed on a metal plate, and if necessary, a friction modifier is applied, or a C layer is laminated on the metal plate. The force that can be formed by forming a melted resin composition A on this C layer and applying a friction modifier as necessary. Alternatively, a method of forming the A layer and the C layer in the form of a film and laminating them on a metal plate will be described.

[0102] For layer A, for example, aliphatic polyester-based resin, fine powder filler, friction modifier and other components as necessary are mixed to obtain resin composition A, which is melt-formed. The film A may be obtained by stretching as necessary. Details will be described below.

[0103] First, a resin composition A is prepared by blending an aliphatic polyester-based resin with a fine powder filler and, if necessary, other additives such as a hydrolysis inhibitor.

[0104] When a kneading-type friction modifier is used, the friction modifier is added here. Specifically, a fine powder filler, friction modifier, hydrolysis inhibitor, etc. are mixed with an aliphatic polyester resin, mixed with a ribbon blender, tumbler, Henschel mixer, etc., and then a Banbury mixer. Using a single or twin screw extruder, etc., the temperature above the melting point of the resin ( For example, in the case of a lactic acid-based polymer, the kneaded composition A is obtained by kneading at 170 ° C. to 230 ° C.).

[0105] A resin composition A is obtained by adding a predetermined amount of an aliphatic polyester-based resin and a fine powder filler, a friction modifier, a hydrolysis inhibitor, etc. using separate feeders and the like. You can also. In addition, a so-called master batch in which a fine powder filler, an anti-hydrolysis agent, etc. are blended in high concentration in an aliphatic polyester-based resin is prepared in advance, and this master notch and the aliphatic polyester-based resin are mixed. Thus, it is possible to obtain a desired concentration of rosin composition A.

[0106] Next, the resin composition A thus obtained is melted and formed into a film A.

For example, the resin composition A is dried, supplied to an extruder, heated to a temperature equal to or higher than the melting point of the resin, and melted. At this time, the rosin composition A may be supplied to the extruder without drying, but if not dried, it is preferable to use a vacuum vent during melt extrusion.

[0107] Conditions such as the extrusion temperature must be set in consideration of a decrease in molecular weight due to decomposition. For example, the extrusion temperature used a lactic acid-based polymer as an aliphatic polyester-based resin. If this is the case, a range of 170 ° C to 230 ° C is preferred! /.

Then, the melted rosin composition A is extruded into a slit-shaped discharge loci of a T die, and is closely adhered to a cooling roll to form a cast sheet (unstretched state) to obtain a film A.

On the other hand, in the case of a coating type friction modifier, a water-soluble coating solution containing a friction modifier may be applied to the film A and dried.

[0109] Application methods include spray coating, air knife method, reverse coating method, kiss coating method, gravure coating method, metal ring bar method, roll brush method, dip coating method, calendar coating method, skies coating method, phanten coating method. A coat or the like can be applied.

[0110] For example, in the case of an unstretched film, an aqueous coating solution may be applied to an unstretched film formed using an extruder equipped with a T die, and then dried in a drying furnace. You may blow directly on the film.

[0111] The film A (cast sheet) obtained as described above can be stretched 1.1 times or more in at least a uniaxial direction. The fine powder filler is cored inside the film by stretching. As a result, the interface between the resin and the void and the interface between the void and the fine filler are formed, and the effect of refraction and scattering generated at the interface is increased. That's right.

[0112] The stretching temperature at the time of stretching is preferably within the predetermined temperature range (Tg to Tg + 50 ° C) from the glass transition temperature (Tg) of the aliphatic polyester-based resin. In the case of a polymer, the temperature is preferably 50 to 90 ° C. If the stretching temperature is within this range, the stretching can be performed stably without breaking during stretching, and the stretching orientation becomes high. As a result, the porosity becomes large. Can be easily obtained.

[0113] Film A is more preferably biaxially stretched than uniaxially stretched. By biaxial stretching, the porosity is further increased, and the light reflectivity of the A layer can be further enhanced. The stretching order of the biaxial stretching is not particularly limited. For example, simultaneous biaxial stretching or sequential stretching may be used.

[0114] Specifically, for example, the film may be melt-formed using a stretching facility, then stretched to MD by roll stretching, and then stretched to TD by tenter stretching, or by tubular stretching or the like. Biaxial stretching may be performed.

[0115] The stretching ratio in the case of uniaxial stretching or biaxial stretching may be appropriately determined according to the composition of layer A, the stretching means, the stretching temperature, and the target product form. It is preferable to stretch. It is more preferable to stretch the film by 7 times or more. If the cast sheet is stretched so that the area magnification is 5 times or more, a porosity of 5% or more can be realized in layer A, and a porosity of 20% or more can be realized by stretching it 7 times or more. By stretching to 7.5 times or more, a porosity of 30% or more can be realized, and the reflectance can be further increased.

[0116] In order to impart heat resistance and dimensional stability to the obtained film A, heat treatment is preferably performed.

[0117] The heat treatment temperature of the film-like A layer is preferably 90 to 160 ° C, more preferably 110 to 140 ° C. The treatment time required for the heat treatment is preferably 1 second to 5 minutes. There are no particular limitations on the stretching equipment and the like, but it is preferable to perform tenter stretching that can be heat-set after stretching. [0118] Next, the film A produced as described above may be laminated on a metal plate via a film B made of polyester-based resin constituting the C layer to produce a light reflector! .

[0119] Examples of the laminating method in this case include a method in which a film B and a film A are stacked in this order on a metal plate, and in this state, supplied to a heating and pressing roll and thermally fused. The temperature for heat-sealing is preferably in the temperature range of 140 ° C. to 280 ° C., more preferably in the temperature range of 150 ° C. to 210 ° C. from the viewpoint of adhesion. The surface temperature of the metal plate can be heated so as to be about the melting point of the resin constituting the A layer and the C layer, and can be heat-sealed with a rubber roll.

[0120] [Second Embodiment]

The light reflector according to this embodiment (“the present light reflector” t) is formed by laminating an A layer mainly composed of an aliphatic polyester-based resin and fine powder filler on one or both surfaces of a metal plate. B layer formed from thermosetting resin or ionizing radiation curable resin is laminated on the surface side of layer A on at least one side, and the static friction coefficient and dynamic friction coefficient of the surface of the B layer are within a predetermined range. It is a light reflector formed so that

Note that the A layer may be provided on one side or both sides of the metal plate. For example, a C layer may be interposed between the metal plate and the A layer.

[0121] Also in this embodiment, the A layer, the metal plate, and the C layer are the same as those in the first embodiment. Therefore, here, the B layer will be described, and then the configuration and characteristics of the light reflector are described. The manufacturing method will be described.

[0122] <layer>

The B layer can be formed from a thermosetting resin or an ionizing radiation curable resin. Among them, it is preferable to form from ionizing radiation curable resin from the viewpoint of work environment and productivity.

[0123] The ionizing radiation curable resin may be any resin that is cured by irradiation with ionizing radiation such as ultraviolet rays or electron beams. Examples thereof include a resin having at least one radically polymerizable double bond capable of undergoing a polymerization crosslinking reaction by irradiation with ionizing radiation, and appropriately containing a prepolymer, an oligomer and Z or a monomer. In the case of ultraviolet curable resin, it is common to contain a photopolymerization initiator. [0124] Further, the ionizing radiation curable resin may contain an additive such as a sensitizer, a non-reactive resin, a leveling agent, and a solvent as necessary. Moreover, you may contain the silicone oil and the resin containing silicone.

[0125] Examples of the prepolymers and oligomers include polyester acrylates, urethane acrylates, epoxy acrylates, polyether acrylates, polyol acrylates, silicone acrylates and other acrylates, polyester metatalates, and urethane metatalates. And metatalates such as epoxy metatalylate, polyether metatalylate, polyol metatalylate, and silicone metatalylate.

[0126] The refractive index of the B layer is not particularly limited. However, in order not to impair the high reflection performance of the A layer, the refractive index is about 1.4 to 1.8, particularly about 1.4 to 1.6. It is preferable to select the fat to form the B layer.

[0127] The B layer may contain a fine particulate filler. As such a fine particle filler, the same force as the fine particle filler in the above-described A layer can be used. Curability of the B layer, adhesion with the A layer, and reflection as a light reflector Considering setting the static friction coefficient and dynamic friction coefficient on the surface of layer B within the specified ranges without impairing performance, etc., a fine filler with an average particle size of 0.3 m or less is particularly preferred. Siri force of 0.2 m or less is superior.

[0128] (Static friction coefficient and dynamic friction coefficient on the surface of layer B)

The layer B surface preferably has a static friction coefficient of 0.49 or less and a dynamic friction coefficient of 0.42 or less.

[0129] If the static friction coefficient on the surface of layer B is 0.49 or less and the dynamic friction coefficient is 0.42 or less, for example, the reflector is processed into a reflector and incorporated in a liquid crystal display of a notebook computer. In this case, it is possible to effectively reduce the generation of noise when the monitor unit is opened and closed.

[0130] From this point of view, the static friction coefficient of the surface of the B layer is more preferably 0.46 or less, and still more preferably 0.43 or less. Further, the coefficient of dynamic friction is more preferably 0.36 or less, and still more preferably 0.33 or less.

[0131] <Structure of light reflector> The light reflector can be configured by directly laminating the A layer on one or both surfaces of the metal plate, or by interposing the C layer between the A layer and the metal plate. Thus, for example, B layer, ZA layer, Z metal plate, 3 layer configuration, B layer, ZA layer, Z metal plate, ZA layer, or B layer, ZA layer, ZC layer, 4 layer configuration, consisting of Z metal plate, B layer, ZA layer, ZC layer, Z metal Plate 5 layers consisting of ZA layer, B layer ZA layer ZC layer Z metal plate ZA layer ZB layer, B layer ZA layer ZC layer Z metal plate ZC layer ZA layer, B layer ZA layer ZC layer Z metal plate ZC layer ZA Layer ZB layer or higher multi-layer structure.

It can also be formed as a laminated structure including other layers (such as an adhesive layer) other than the A layer, the B layer, and the C layer.

[0132] The order of formation of each layer is not particularly limited. For example, after forming the B layer on the A layer, the layer is laminated with the metal plate, and after the A layer is laminated on the metal plate, B A layer may be laminated on the surface side of the A layer.

[0133] In such a configuration, the thickness of the A layer is preferably 50 m to 250 m.

[0134] The thickness of the B layer is preferably 1 μm to 10 μm, more preferably 1 μm to 7 μm, and particularly preferably 2 m to 5 μm! / ヽ.

The thickness of the C layer is preferably 5 μm to 100 μm.

[0135] The thickness of the entire light reflector varies depending on the desired application and the metal plate to be used.

Although not particularly limited, considering the use as a light reflector for small and thin reflectors, it is more preferable to set the thickness to 0.1 to 0.7 mm, even though it is preferable to set the thickness to 0.05 mm to lmm. That's right.

[0136] <Reflection characteristics of light reflector>

[0137] <Application>

As described above, this light reflector has both high reflection performance, high heat resistance, and is suitable as a reflector for displays such as TVs, lighting fixtures, and lighting signs. In addition, it can be suitably used as a member called a reflector that is formed by molding a light reflector.

[0138] <Production method>

[0139] In the present light reflector, a film A was prepared in the same manner as in the first embodiment, and then a thermosetting or ionizing radiation curable resin coating solution was prepared and applied onto the film A. After removing the solvent by drying, it can be cured by heating or irradiation with ionizing radiation to form layer B.

[0140] The film A for forming the B layer may be a film that has not been stretched or heat-treated! /, But is preferably a stretched or heat-treated film. Specifically, when forming the B layer on the film A by coating, a method of forming an outline on the stretched or heat-treated film A may be employed, or an unstretched cast film may be used. It is possible to adopt a method (so-called in-line coating) in which the B layer is applied in-line in the film forming process, followed by stretching or heat treatment.

[0141] Examples of the coating method for thermosetting resin or ionizing radiation curable resin include well-known coaters such as bar coaters, blade coaters, ronore coaters, gravure coaters, spin coaters, spray coaters, The coating can be formed by a known coating method such as dip coating.

[0142] The layer B can also be formed by a known printing method such as gravure printing, offset printing, or screen printing.

[0143] When the B layer is formed on the A layer, the adhesion on the surface of the A layer may be enhanced by a surface treatment method such as a corona discharge treatment (the same means as the surface treatment of the metal plate described above). Can be used). Further, an anchor coat layer, an adhesive layer or the like may be interposed between both layers.

[0144] Next, the film A having the B layer produced as described above is laminated on a metal plate via the film C made of polyester-based resin constituting the C layer, and this light reflector is formed. It can be manufactured.

[0145] As a method of laminating at this time, film A having film C and layer B on a metal plate is used. In this state, a method of supplying the heat and pressure roll and heat-sealing in this state can be mentioned.

The temperature for heat-sealing is preferably in the temperature range of 140 ° C. to 280 ° C., more preferably in the temperature range of 150 ° C. to 210 ° C. from the viewpoint of adhesion.

The surface temperature of the metal plate can be heated to about the melting point of the resin constituting the A layer and the C layer, and heat fusion can be performed with a rubber roll.

Example

Hereinafter, the present invention will be described more specifically based on examples and comparative examples. However, the scope of the present invention is not limited to the examples, and does not depart from the technical idea of the present invention. Various applications are possible.

[0147] The measured values and evaluations shown in the examples were performed as follows. The film take-off (flow) direction is indicated by MD, and its orthogonal direction is indicated by TD.

[0148] <Measurement and evaluation method>

(1) Static friction coefficient 'Dynamic friction coefficient

Based on JIS K 7125, the static friction coefficient and dynamic friction coefficient of the surface of the A layer were measured. In this case, measurement was performed at n = 5 and the average value is shown in Table 1.

[0149] (2) Adhesion

A method of visually observing whether or not peeling of a metal sheet is permitted when extruding 4 mm using a drawing Eriksen tester compliant with JIS Z 2247. Those having no problem were judged as △, and those with film peeling were judged as X.

[0150] (3) Reflectance

An integrating sphere is attached to a spectrophotometer ("U-4000", manufactured by Hitachi, Ltd.), and the reflectance with respect to light with a wavelength of 550 nm is measured. A value of less than 1% (less than 0.5%) was evaluated as △, and a value showing a decrease in reflectivity (over 0.5%) was determined as X. Before the measurement, the photometer was set so that the reflectance of the alumina white plate was 100%.

[0151] (4) Noise sound evaluation The light reflector was processed into a 17-inch notebook reflector and incorporated into an actual notebook PC to evaluate the sound when it was opened and closed.

○ No sound

△ · · · Sound is faint

X · · · Sound

[0152] (5) Average particle size

Using a powder specific surface measuring instrument (transmission method) of model “SS-100” manufactured by Shimadzu Corporation, fill a sample tube with a cross-sectional area of 2 cm ² and a height of 1 cm with 3 g of sample and 20 cc with a 500 mm water column. The average particle size was calculated from the air permeation time.

[0153] ( ⁶ ) Niobium concentration in acid 匕 titanium (ppm)

The niobium content was measured based on JIS M-8321 “Ti ore and niobium determination method”. That is, 0.5 g of a sample is weighed, and this sample is transferred to a nickel crucible containing 5 g of a molten mixture [sodium hydroxide: sodium peroxide = 1: 2 (mass ratio)] and stirred. The surface of the sample was covered with about 2 g of anhydrous sodium carbonate, and the sample was heated and melted in a crucible to form a melt. The melt was allowed to cool in the state of being put in a crucible, and then 100 ml of warm water and 50 ml of hydrochloric acid were added to the melt to dissolve it, and water was added to make up to 250 ml. . This solution was measured with an ICP emission spectrophotometer to determine the niobium content. However, the measurement wavelength was 309.42 nm.

[0154] [Example 1]

Lactic acid-based polymer having a weight average molecular weight of 200,000 (NW4032D: manufactured by Cargill Dow Polymer Co., Ltd., L-form: D-form = 98.5: 1.5, glass transition temperature 65 ° C) Titanium oxide of 25 (rutile type, niobium concentration 430ppm; surface treatment with silica, alumina and zircoure, manufactured by chlorine process) A mixture of 30 parts by weight of a resin composition was set at 220 ° C Melt with an extruder, extrude, cool with a cast roll, where a solution of Electro Stripper AC (; trade name, manufactured by Kao, composition: linear alkyl benzene sulfonic acid series) as a friction modifier, thickness after drying Is applied to the cast surface to a thickness of 0.1 μm, stretched biaxially 2.5 times to MD and 2.8 times to TD at a temperature of 65 ° C, and then heat-treated at 140 ° C. A cast sheet having a thickness of 75 μm was obtained. [0155] Next, a 15 μm-thick film composed of a terephthalic acid-isophthalic acid polyester copolymer (copolymerized PET) is interposed between the cast sheet and a stainless steel plate (thickness: 0.1 mm, SUS304). And heat-sealed at 180 ° C. to obtain a light reflector having a thickness of about 190 m.

This light reflector was evaluated for static friction coefficient, dynamic friction coefficient, adhesion, reflectivity, and noise noise, and the results are shown in Table 1.

[0156] [Example 2]

In Example 1, except for using Riquemar A (; trade name, manufactured by Riken Vitamin Co., Ltd., composition: sucrose fatty acid ester system) instead of Electrostopper AC used as a friction modifier, Example 1 A light reflector was obtained in the same manner as described above, and the static friction coefficient, dynamic friction coefficient, adhesion, reflectance, and noise sound were evaluated, and the results are shown in Table 1.

[0157] [Comparative Example 1]

Lactic acid-based polymer having a weight average molecular weight of 200,000 (NW4032D: manufactured by Cargill Dow Polymer Co., Ltd., L-form: D-form = 98.5: 1.5, glass transition temperature 65 ° C) Titanium oxide of 25 (rutile type, niobium concentration: 430 ppm; surface treatment with silica, alumina and zircoure, manufactured by chlorine process) Melt with an extruder, extrude, cool with a cast roll, and without applying a friction modifier, at a temperature of 65 ° C, biaxially stretched 2.5 times to MD and 2.8 times to TD, then 140 ° C And a cast sheet having a thickness of 75 μm was obtained.

[0158] Next, a 15 μm thick film made of terephthalic acid-isophthalic acid polyester copolymer (copolymerized PET) is interposed between the cast sheet and the stainless steel plate (thickness: 0.1 mm, SUS304). And heat-sealed at 180 ° C. to obtain a light reflector having a thickness of about 190 m.

[0159] [Table 1] Friction coefficient

Friction modifier Reflectance Noise Noise Adhesion

Coefficient of static friction Coefficient of dynamic friction

Example 1 Electric stripper AC 100. 2 0. 46 0. 36 ○ ○ Example 2 Riquemar A 100. 2 0. 44 0. 35 ○ ○ Comparative example 1 None 100. 2 0. 51 0. 45 X ○ [0160] [Example 3]

Lactic acid-based polymer having a weight average molecular weight of 200,000 (NW4032D: manufactured by Cargill Dow Polymer Co., Ltd., L-form: D-form = 98.5: 1.5, glass transition temperature 65 ° C) Titanium oxide of 25 (rutile type, niobium concentration 430ppm; surface treatment with silica, alumina and zircoure, manufactured by chlorine process) A mixture of 30 parts by weight of a resin composition was set at 220 ° C Melted with an extruder, extruded, cooled with a cast roll, and biaxially stretched 2.5 times to MD and 2. 8 times to MD at a temperature of 65 ° C, then heat treated at 140 ° C to a thickness of 75 An m film (A layer) was obtained.

Next, 50 parts by mass of a hexafunctional acrylate monomer on the reflective use surface side of this A layer, 30 parts by mass of silica fine particles having an average particle diameter of 20 nm with the surface being transparent, 5 parts by mass of a photopolymerization initiator, 15 parts by mass of tilethyl ketone was mixed, dried with a roll coater and coated to a thickness of 2 m, dried with a solvent, and irradiated with 300 miZcm ² of ultraviolet light with a high-pressure mercury lamp to form layer B.

[0162] Next, a 15 μm-thick fiber made of terephthalic acid isophthalic acid polyester copolymer (copolymerized PET) is formed between the B layer ZA layer and a stainless steel plate (thickness: 0.1 mm, SUS304). Lum was interposed and heat-sealed at 180 ° C to obtain a light reflector with a thickness of about 192 m.

[0163] This light reflector was subjected to the above-described slipperiness, adhesion, reflectance evaluation, and noise sound evaluation. Table 2 shows the evaluation results.

[0164] [Comparative Example 2]

[0165] Next, without applying the B layer in Example 1 on the reflective use surface side of the A layer, between the A layer and the stainless steel plate (thickness: 0.1 mm, SUS304), monoisophthalate terephthalate. Acid polyester A 15 m thick film with a tercopolymer (copolymerized PET) force was interposed and heat-sealed at 180 ° C to obtain a light reflector with a thickness of about 190 m.

[0166] This light reflector was subjected to the above-mentioned slipperiness, adhesion, reflectance evaluation, and noise sound evaluation. Table 2 shows the evaluation results.

[0167] [Table 2]

As is apparent from Table 2, the light reflector of Example 3 provided with a B layer made of ionizing radiation curable resin on the surface was compared with the light reflector of Comparative Example 2 having no B layer on the surface. Noise noise could be reduced without impairing adhesion and reflectivity.

Claims

The scope of the claims

[1] A light reflector having a configuration in which an A layer containing an aliphatic polyester-based resin and a fine powder filler is laminated on one side or both sides of a metal plate, and includes at least light The static friction coefficient of the surface on one side of the reflector is 0.49 or less, and the dynamic friction coefficient is 0.

A light reflector that is 42 or less.

2. The light reflector according to claim 1, wherein the static friction coefficient of the surface of the A layer on at least one side is 0.49 or less and the dynamic friction coefficient is 0.42 or less.

[3] A layer B formed of thermosetting resin or ionizing radiation curable resin is provided on the surface side of layer A on at least one side, and the coefficient of static friction of the surface of layer B is 0.49 or less. The light reflector according to claim 1, wherein the coefficient of dynamic friction is 0.42 or less.

[4] The aliphatic polyester-based resin of layer A is a lactic acid-based polymer.

The light reflector according to any one of 1 to 3.

[5] The light according to any one of claims 1 to 4, wherein the fine powder filler contained in the A layer is contained in a proportion of 10% by mass to 60% by mass with respect to the entire A layer. Reflector.

[6] The fine powder filler contained in the A layer is titanium oxide.

6. The light reflector according to any one of 5.

[7] The light reflector according to any one of [1] to [6], wherein the fine powder filler contained in the A layer is titanium oxide with a niobium content of 500 ppm or less.

[8] The fine powder filler contained in the A layer is titanium oxide, and the surface thereof is coated with at least one inert inorganic acid selected from the group consisting of silica, alumina, and zirconium oxide. The light reflector according to claim 1, wherein the light reflector is a light reflector.

[9] A backlight device for a liquid crystal display device using the light reflector according to any one of claims 1 to 8.