TW201905080A - Polyester composition for LED reflector, LED reflector composed of the composition, and light-emitting device including the reflector - Google Patents

Abstract

A polyester composition for LED reflection plates, which contains a polyester (A) and a surface-coated titanium oxide (B), and wherein 50% by mole or more of dicarboxylic acid units is composed of terephthalic acid units and 50% by mole or more of diol units is composed of 1, 4-cyclohexane dimethanol units in the polyester (A), the ignition loss of the titanium oxide (B) is 0.50-1.20% by mass, and the content of the titanium oxide (B) is 10-90 parts by mass relative to 100 parts by mass of the polyester (A); and an LED reflection plate which is formed from this composition; and a light emitting device which is provided with this reflection plate.

Description

   Polyester composition for LED reflecting plate, LED reflecting plate composed of the same, and light emitting device provided with the reflecting plate   

The present invention relates to a polyester composition for an LED reflecting plate, an LED reflecting plate composed of the composition, and a light-emitting device having the reflecting plate.

Compared with conventional white or fluorescent lamps, light-emitting diodes (hereinafter also referred to as "LEDs") have lower power consumption and longer life. They have many advantages, and are therefore used in various fields. Smaller electronic products such as backlights for liquid crystal panels of mobile phones, personal computers, and LCD TVs.

LED packages are generally composed of LEDs, lead frames, reflectors that also serve as housings, and sealing members that seal semiconductor light-emitting elements. There have been attempts to develop and use polymer materials to replace conventional ones. Ceramic is used as the material of the LED reflector.

However, a reflective plate using a polymer material has problems such as a decrease in light reflectance due to heat in the manufacturing steps of the LED package, and a decrease in light reflectance due to a use environment such as ultraviolet irradiation.

In response to such a problem, for example, Patent Document 1 discloses an LED reflecting plate using a dicarboxylic acid unit including a 1,4-cyclohexanedicarboxylic acid unit and an aliphatic diamine unit including a carbon number of 4 to 18. It is described that the polyamidoamine composition of the diamine unit can maintain high reflectance and whiteness even after long-term LED light irradiation.

However, in recent years, with the reduction in the price of LEDs, not only electronic products, but also the use of LEDs as lighting equipment has gradually expanded. In the case of using LEDs as lighting fixtures, compared with conventional reflectors used in electronic products, the LED packages require higher heat resistance and higher reflectance because of the manufacturing steps or the environment of use. It also suppresses the decrease in reflectance caused by light such as heat or ultraviolet rays. In response to such a demand, an attempt has been made to use a polyester having higher heat resistance instead of polyamine as a material of a reflective plate.

For example, Patent Document 2 discloses a light-emitting diode module housing containing a titanium dioxide-containing poly (1,4-cyclohexanedimethanol terephthalate) composition, and describes that it exhibits good reflectance and good UV resistance, color stability to heat.

    [Prior technical literature]         [Patent Document 1    

[Patent Document 1] International Publication No. 2011/027562

[Patent Document 2] Japanese Patent Publication No. 2009-507990

However, polyester is a resin that is prone to hydrolysis. Therefore, as the molecular weight decreases due to hydrolysis, moldability and reflectance are likely to decrease. It is therefore necessary to have excellent formability and maintain high reflectance even after being exposed to heat or light from the manufacturing steps of the LED package or the use environment.

An object of the present invention is to provide a polyester composition for an LED reflecting plate, which has excellent moldability and has a small decrease in reflectance even after being exposed to heat or light, and can maintain a high reflectance; The LED reflecting plate constituted; and a light-emitting device including the reflecting plate.

The inventors of the present invention conducted a review, and as a result, found that the above-mentioned problem can be solved by the polyester composition containing a specific surface-coated titanium oxide at a specific ratio.

That is, the present invention relates to the following [1] to [8].

[1] A polyester composition for an LED reflector, wherein the polyester composition contains polyester (A) and a surface-coated titanium oxide (B), and the polyester (A) has a structural unit derived from a dicarboxylic acid More than 50 mol% of structural units derived from terephthalic acid, and more than 50 mol% of structural units derived from diols are structural units derived from 1,4-cyclohexanedimethanol; the titanium oxide ( B) Preheating treatment at 120 ° C for 2 hours, and Ignition Loss caused by the main heating during the main heating treatment at 550 ° C for 2 hours are 0.50 to 1.20% by mass; the amount of the titanium oxide (B) Content is 10-90 mass parts with respect to 100 mass parts of this polyester (A).

[2] The polyester composition for an LED reflecting plate as described in [1] above, in which the polyester (A) is a structural unit derived from dicarboxylic acid in an amount of 75 to 100 mol%, and is a structural unit derived from terephthalic acid. And 75 ~ 100 mol% derived from the structural unit of the diol is poly (dimethyl terephthalate) derived from the structural unit of 1,4-cyclohexanedimethanol.

[3] The polyester composition for an LED reflecting plate according to the above [1] or [2], further comprising 5 to 50 parts by mass of a reinforcing material (C) based on 100 parts by mass of the polyester (A).

[4] The polyester composition for an LED reflecting plate according to the aforementioned [3], wherein the reinforcing material (C) is glass fiber.

[5] The polyester composition for an LED reflecting plate according to any one of the above [1] to [4], further containing 0.10 to 1.0 part by mass of an antioxidant (based on 100 parts by mass of the polyester (A) ( D).

[6] The polyester composition for an LED reflecting plate according to any one of the above [1] to [5], further containing a light stabilizer (E).

[7] An LED reflector comprising the polyester composition for an LED reflector as described in any one of the above [1] to [6].

[8] A light emitting device including the LED reflecting plate as described in [7] above.

According to the present invention, it is possible to provide a polyester composition for an LED reflecting plate which has excellent moldability and has a small decrease in light reflectance even after being exposed to heat or light, and which is capable of maintaining a high light reflectance, LED reflecting plate and light emitting device provided with the reflecting plate.

1, 2, 3‧‧‧‧ light-emitting devices

10‧‧‧Semiconductor light emitting element

20‧‧‧ substrate

30‧‧‧Reflector (frame)

40‧‧‧sealing member

50‧‧‧ Encapsulated section

60‧‧‧Sealing member

70‧‧‧ substrate

71‧‧‧Wiring

80‧‧‧ lead frame

FIG. 1 is a schematic diagram showing an example of a configuration of a light emitting device according to the present invention.

FIG. 2 is a schematic diagram showing an example of a configuration of a light emitting device according to the present invention.

FIG. 3 is a schematic diagram showing an example of a structure of a light emitting device according to the present invention.

    [Polyester composition for LED reflector]    

The polyester composition (hereinafter also referred to as a "polyester composition") for the LED reflector of the present invention contains polyester (A) and a surface-coated titanium oxide (B). The polyester (A) is derived from two More than 50 mol% of the structural unit of carboxylic acid (hereinafter also referred to as "dicarboxylic acid unit") is a structural unit derived from terephthalic acid (hereinafter also referred to as "terephthalic acid unit"), and is derived from a diol More than 50 mol% of the structural units (hereinafter also simply referred to as "diol units") are structural units derived from 1,4-cyclohexanedimethanol (hereinafter also simply referred to as "1,4-cyclohexanedimethanol" Unit "), the titanium oxide (B) was previously heat-treated at 120 ° C for 2 hours, and the main heat loss caused by the main heating (hereinafter also referred to as" loss-on-loss ") ) Is 0.50 to 1.20% by mass, and the content of the titanium oxide (B) is 10 to 90 parts by mass based on 100 parts by mass of the polyester (A).

In addition, the LED reflecting plate made of the polyester composition of the present invention is also simply referred to as a "reflecting plate".

With the polyester composition of the present invention, with the above-mentioned structure, the loss on ignition of the surface-coated titanium oxide is in a specific range, and the titanium oxide is contained in a specific ratio. Therefore, the polyester composition can be obtained with excellent moldability, and Even after exposure to heat or light, there is little decrease in the reflectance, and the effect of the so-called present invention that maintains a high reflectance can be maintained.

The reason why such an effect can be obtained is not clear, but it can be estimated as described below.

The surface activity of titanium oxide affects the weather resistance, light resistance, and other characteristics of LED reflectors. Therefore, it is usually coated with a surface treatment agent and used. When the surface treatment amount of titanium oxide is small, the effect of reducing the surface activity of titanium oxide is small, and the weather resistance and light resistance are not sufficiently improved. In addition, it is thought that if the surface treatment amount of titanium oxide is too large, when it is exposed to mixing of the polyester composition, or during injection molding in the manufacturing process of the LED package, or when using ambient heat or light, aluminum oxide or silicon dioxide, etc. Crystal water and the like contained in the surface treatment agent are volatilized, and hydrolysis of the polyester proceeds. As the molecular weight decreases, the moldability and optical characteristics decrease.

Then, as an index of the amount of water derived from the surface coating of the surface-coated titanium oxide, the loss of ignition of the titanium oxide is focused on, and the content of the titanium oxide is determined in the specific range by setting the loss of ignition to a specific range. As the crystallization water and the like contained in the surface treatment agent are volatilized, the hydrolysis of the polyester is suppressed. As a result, the polyester composition of the present invention is considered to have excellent moldability, and it is considered that the polyester composition has excellent moldability even when exposed to heat or light After that, there is little decrease in the reflectance, and a high reflectance can be maintained.

    <Polyester (A)>    

The polyester composition of the present invention contains polyester (A), in which 50 mol% or more of the dicarboxylic acid unit is a terephthalic acid unit, and 50 mol% or more of the diol unit is 1 , 4-cyclohexanedimethanol unit. By containing the polyester (A), it is possible to obtain a reflector having high heat resistance and a decrease in the reflectance even after being exposed to heat or light, and can maintain a high reflectance.

The total content of the dicarboxylic acid unit and the diol unit constituting the polyester (A) is preferably 85 moles relative to the number of moles of all the structural units constituting the polyester (A) from the viewpoint of improvement in heat resistance. % Or more, preferably 90 mol% or more. The polyester (A) is described in further detail below.

50 mol% or more of the dicarboxylic acid unit constituting the polyester (A) is a terephthalic acid unit. Thereby, the heat resistance of the obtained reflection plate improves. The content ratio of the terephthalic acid unit in the dicarboxylic acid unit is preferably 60 mol% or more, preferably 75 mol% or more, more preferably 90 mol% or more, and more preferably 100 mol% or less.

The dicarboxylic acid unit constituting the polyester (A) may contain a structural unit derived from a dicarboxylic acid other than terephthalic acid in a range of 50 mol% or less. Examples of the other dicarboxylic acids include aliphatic dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, succinic acid, azalea acid, and lipoic acid; 1,3 -Alicyclic dicarboxylic acids such as cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid; isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1, 4-naphthalenedicarboxylic acid, 1,4-phenylene dioxydiacetic acid, 1,3-phenylene dioxydiacetic acid, diphthalic acid, diphenylmethane-4,4'-dicarboxylic acid, di Aromatic dicarboxylic acids other than terephthalic acid, such as phenylhydrazone-4,4'-dicarboxylic acid and 4,4'-biphenyldicarboxylic acid, may contain one or two of these the above. The other dicarboxylic acid is preferably isophthalic acid. The content of the structural units derived from these other dicarboxylic acids in the aforementioned dicarboxylic acid units is preferably 25 mol% or less, and more preferably 10 mol% or less.

In addition, the polyester (A) may contain a structural unit derived from a polyvalent carboxylic acid such as trimellitic acid, pyromellitic acid, pyromelic acid, and the like within a melt-moldable range.

50% or more of the diol units constituting the polyester (A) are 1,4-cyclohexanedimethanol units. This can improve the formability and heat resistance of the reflective plate, and can reduce the reflectance even after exposure to heat or light, and can maintain a high reflectance of the reflective plate. The content of the 1,4-cyclohexanedimethanol unit in the aforementioned diol unit is preferably 60 mol% or more, preferably 75 mol% or more, more preferably 90 mol% or more, and more preferably 100 Moore% or less.

From the standpoint of heat resistance, it is preferable that the trans isomer ratio of 1,4-cyclohexanedimethanol is high. The ratio of the trans isomer is preferably 50 to 100% by mass, and more preferably 60 to 100% by mass.

The diol unit constituting the polyester (A) may contain a structural unit derived from a diol other than 1,4-cyclohexanedimethanol in a range of 50 mol% or less. Examples of the other diol include ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, and 2 1,3-butanediol, neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonane Aliphatic diols such as diols, 1,10-decanediol, 1,12-dodecanediol; 1,4-cyclohexanediol, hydrogenated bisphenol A (2,2-bis (4-hydroxy Cyclohexyl) propane), and other alkylene oxides such as alkylene oxides having 2 to 4 carbon atoms (average addition mole number is 2 to 12) other than 1,4-cyclohexanedimethanol Cyclic diols; aromatic diols such as hydroquinone, bis (4-hydroxyphenyl) methane, 2,2-bis (4-hydroxyphenyl) propane, 1,5-dihydroxynaphthalene, etc., may contain this One or more of them. The content of the structural units derived from these other diols in the diol unit is preferably 25 mol% or less, and more preferably 10 mol% or less.

In addition, the polyester (A) may contain a structural unit derived from a trivalent or higher polyhydric alcohol such as trimethylolpropane, glycerol, neopentyl alcohol, and the like within a range capable of being melt-molded.

Polyester (A) uses 75 to 100 mole% of structural units derived from dicarboxylic acids as structural units derived from terephthalic acid and 75 to 100 mole% of structural units derived from diols as derived Polyethylene terephthalate having a structural unit of 1,4-cyclohexanedimethanol is preferred. Thereby, it is possible to obtain a reflector having high heat resistance, and even after being exposed to heat or light, there is little decrease in the reflectance, and a high reflectance can be maintained.

The polyester (A) used in the present invention can be produced by any method known as a method for producing a polyester. For example, it can be manufactured by adding a catalyst such as a titanium compound, an inorganic phosphorus compound, a molecular weight adjuster, etc. as necessary, and subjecting a dicarboxylic acid component and a diol component to a polycondensation reaction.

The molar ratio (dicarboxylic acid component / diol component) of the dicarboxylic acid component and the diol component supplied to the polycondensation reaction is preferably 0.80 to 0.99 g, preferably 0.83 to 0.98, and more preferably 0.85 to 0.97.

The melting point of the polyester (A) used in the present invention is preferably from 260 ° C or higher, preferably from 270 ° C or higher, or more preferably from 280 ° C or higher from the viewpoint of improvement in heat resistance, and from the viewpoint of forming the LED reflector From the viewpoint of improving properties, the temperature is preferably 320 ° C or lower, preferably 310 ° C or lower, and more preferably 300 ° C or lower. The measurement of the melting point is specifically according to the method described in the examples.

The weight average molecular weight (M _w ) of the polyester (A) used in the present invention is preferably 3,000 to 12,000, preferably 4,000 to 10,000, and more preferably 4,000 to 9,000. When the weight average molecular weight is 3,000 or more, the toughness effect of the polyester (A) can be sufficiently exhibited. When the weight average molecular weight is 12,000 or less, the fluidity is not reduced, and good moldability can be obtained. The weight average molecular weight can be obtained by gel permeation chromatography (GPC) described later, and is a value calculated in terms of standard polymethyl methacrylate conversion. The measurement of the weight average molecular weight is specifically according to the method described in the examples.

    <Surface-coated titanium oxide (B)>    

The polyester composition of the present invention contains a surface-coated titanium oxide (B) (hereinafter also referred to simply as "titanium oxide (B)"). The titanium oxide (B) is previously heat-treated at 120 ° C for 2 hours, and main heat-treated at 550 ° C At 2 hours, the loss on ignition due to the main heating was 0.50 to 1.20% by mass.

Titanium oxide (B) is a material that imparts light reflectivity to the obtained reflecting plate. By containing the titanium oxide (B), the heat conductivity and heat resistance of the reflecting plate are improved, and the light reflection can be suppressed even after exposure to heat or light. Reduced rate can maintain high reflectance.

Examples of the titanium oxide (B) include titanium oxide (TiO), titanium dioxide (Ti ₂ O ₃ ), and titanium dioxide (TiO ₂ ). Any of these may be used, and titanium dioxide is preferred. As the titanium dioxide, a crystal structure having a rutile type or an anatase type is preferable, and a crystal structure having a rutile type is more preferable.

Titanium oxide (B) uses a surface-coating agent from the viewpoint of improving dispersibility, concealability, weather resistance, and light resistance in a polyester composition. Examples of the surface treatment include an inorganic treatment and an organic treatment.

Examples of the surface treatment agent used in the inorganic treatment include oxides, hydroxides, and hydrated oxides of metals such as aluminum, silicon, zirconium, tin, titanium, antimony, zinc, cobalt, and manganese.

Examples of the surface treatment agent used in the organic treatment include organic silicon compounds such as organic silanes, silane coupling agents, and organic polysiloxanes; organic titanium compounds such as titanium coupling agents; organic acids, polyols, alkanolamines, and polysiloxanes. Organic matter such as silicone oil.

Examples of the organic silane include n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, Alkoxysilanes such as 3-chloropropyltriethoxysilane, phenyltriethoxysilane, trifluoropropyltrimethoxysilane, etc.

Examples of the silane coupling agent include 3-aminopropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropyltriethoxysilane, and N-phenyl-3-aminopropyltrimethyl Aminosilanes such as oxysilane; 3-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, etc .; 3 -(Methacryloxypropyl) trimethoxysilane and other methacrylic silanes; vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrichlorosilane, etc .; Mercaptosilanes such as 3-mercaptopropyltrimethoxysilane.

Examples of the organic polysiloxane include dimethylpolysiloxane, methylhydrogenpolysiloxane, and alkyl-modified polysiloxane.

Examples of the titanium coupling agent include isopropyltriisostearylfluorenyl titanate, isoisostearyl isomethionylfluorenyl titanate, and isopropyltridecylbenzenesulfonyl titanic acid. Esters, etc.

Examples of the organic acid include adipic acid, terephthalic acid, lauric acid, myristic acid, palmitic acid, stearic acid, polyhydroxystearic acid, oleic acid, salicylic acid, malic acid, and maleic acid, or Such as metal salts.

Examples of the polyhydric alcohol include trimethylolethane, trimethylolpropane, bis (trimethylolpropane), ethoxylated trimethylolpropane, and neopentyl tetraol.

Examples of the alkanolamine include monoethanolamine, monopropanolamine, diethanolamine, dipropanolamine, triethanolamine, and tripropanolamine.

As the surface treatment, from the viewpoint of suppressing aggregation of titanium oxide and improving dispersibility, an inorganic treatment is preferred. As the surface treatment agent used in the inorganic treatment, an oxide of one or more metals selected from aluminum, silicon, and zirconium is preferred, and one or more metals selected from alumina and silicon dioxide are preferred. From the viewpoint of improvement, alumina is more preferable, and from the viewpoint of improving weather resistance, silicon dioxide is more preferable.

In addition, from the viewpoint of improving the wettability and dispersibility of titanium oxide, it is preferable to use an organic treatment, and from the viewpoint of suppressing moisture adsorption to titanium oxide while imparting hydrophilicity, a polyhydric alcohol is preferable. From the viewpoint of improving the dispersibility and imparting hydrophobicity at the same time, an organic polysiloxane is preferable.

From the viewpoint of improving dispersibility, the surface treatment amount of titanium oxide (B) is preferably 0.10 to 30% by mass, more preferably 1.0 to 20% by mass, and more preferably 2.0% by mass. ~ 15% by mass.

The surface treatment agents may be used alone or in combination of two or more.

In the present invention, the loss on ignition of the titanium oxide (B) is 0.50 to 1.20% by mass.

The loss on ignition was calculated by reducing the mass before and after the main heating at 550 ° C for 2 hours after preheating at 120 ° C for 2 hours. Under such heating conditions, the surface treatment agent remains, and at the same time, the adsorbed crystal water and the like can be released. If the loss on ignition is 0.50% by mass or more, good dispersibility can be imparted. If the loss on ignition is 1.20% by mass or less, hydrolysis of the polyester due to moisture derived from the surface coating of titanium oxide can be suppressed, and molecular weight can be suppressed. Reduced, and at the same time can improve formability and reflectance. From this point of view, the loss on ignition is preferably 0.55 to 1.15 mass%, more preferably 0.60 to 1.10 mass%, more preferably 0.65 to 1.05 mass%, even more preferably 0.70 to 1.00 mass%, and even more preferably 0.70. ~ 0.90% by mass, and even more preferably 0.70 ~ 0.80% by mass. The measurement of the loss on ignition is specifically according to the method described in the examples.

The average particle diameter of the titanium oxide (B) is preferably 0.23 to 0.60 μm. When the average particle diameter is 0.23 μm or more, the contact area with the polyester in the polyester composition can be reduced, and hydrolysis of the polyester caused by moisture derived from the surface coating of titanium oxide can be suppressed. When the average particle diameter is 0.60 μm or less, Suppress light scattering and improve reflectance. From such a viewpoint, it is preferably 0.23 to 0.50 μm, more preferably 0.25 to 0.40 μm, still more preferably 0.25 to 0.35 μm, and even more preferably 0.25 to 0.31 μm.

The average particle diameter of titanium oxide (B) can be obtained by image analysis using an electron microscope method. Specifically, the long and short diameters of 1,000 or more titanium oxide particles photographed using a transmission electron microscope were measured, and the weight average value was determined as the average particle diameter.

The shape of the titanium oxide (B) is not particularly limited, and its agglomerated shape is preferably an amorphous shape. When amorphous titanium oxide (B) is used, the dimensional change rate and the anisotropy of the dimensional change rate of the obtained reflecting plate are small, and peeling from the sealing member at the time of LED package manufacturing can be suppressed.

    <Reinforcing material (C)>    

The polyester composition of the present invention preferably further contains a reinforcing material (C). By including the reinforcing material (C), the formability and mechanical strength of the obtained reflecting plate can be improved.

As the reinforcing material (C), various shapes such as fibrous, flat, needle, powder, and cloth shapes can be used. Specific examples include fibrous reinforcing materials such as glass fibers, carbon fibers, aramid fibers, liquid crystal polymer (LCP) fibers, and metal fibers; flat reinforcing materials such as mica and talc; potassium titanate whiskers and aluminum borate Needle-like reinforcing materials such as whiskers, calcium carbonate whiskers, magnesium sulfate whiskers, wollastonite, sepiolite, xonotlite, zinc oxide whiskers, etc .; silicon dioxide, alumina, barium carbonate, magnesium carbonate, Aluminium nitride, boron nitride, potassium titanate, aluminum silicate (kaolin, clay, pyrophyllite, bentonite), calcium silicate, magnesium silicate (Iertpur), aluminum borate, calcium sulfate, barium sulfate , Magnesium sulfate, asbestos, glass beads, carbon black, graphite, carbon nanotubes, silicon carbide, sericite, hydrotalcite, molybdenum disulfide, phenol resin particles, crosslinked styrene resin particles, crosslinked acrylic resin particles Powder-like reinforcing materials such as glass; cloth-like reinforcing materials such as glass cloth. These reinforcing materials can be used alone or in combination of two or more.

These reinforcing materials may be those having been subjected to a surface treatment from the viewpoint of improving the dispersibility in the polyester composition and from the viewpoint of improving the adhesiveness with the polyester (A). Examples of the surface treatment agent include a polymer compound such as a silane coupling agent, a titanium coupling agent, an acrylic resin, a urethane resin, and an epoxy resin, or other low-molecular compounds.

The reinforcing material (C) used in the present invention is preferably one or more selected from the group consisting of fibrous reinforcing materials and needle-shaped reinforcing materials from the viewpoint of cost reduction and mechanical strength improvement among the aforementioned reinforcing materials. . From the viewpoint of cost reduction and the viewpoint of improvement of mechanical strength, a fibrous reinforcing material is more preferable, and glass fiber is more preferable. In addition, from the viewpoint of obtaining a reflective plate having a high surface smoothness, a needle-like reinforcing material is preferred. In particular, from the viewpoint of maintaining the whiteness of the reflecting plate, one or more members selected from the group consisting of glass fiber, wollastonite, potassium titanate whiskers, calcium carbonate whiskers, and aluminum borate whiskers are preferred. One or more kinds of fiber and wollastonite are preferable, and glass fiber is more preferable.

The average fiber length of the glass fiber is preferably 1.0 to 10 mm, preferably 1.0 to 7.0 mm, and more preferably 2.0 to 4.0 mm.

The average fiber length is the former mixed with the polyester composition.

In the polyester composition or the LED reflecting plate formed by the composition, the average fiber length of the glass fibers is preferably 50 to 500 μm, preferably 80 to 400 μm, and more preferably 100 to 300 μm.

In addition, the cross-sectional shape of the glass fiber is not particularly limited. From the viewpoint of productivity and mechanical strength, a profiled cross section or a circular cross section is preferred, and a circular cross section is preferred from the viewpoint of cost reduction.

Here, the glass fiber having a special-shaped cross section refers to a cross section perpendicular to the length direction of the fiber, and the cross section outer peripheral length of the cross section outer peripheral length of the glass fiber having a cross section having the same cross section is 1.05 times to 1.7. Glass fiber with double cross-section shape. The cross-sectional shape is particularly preferably an eyebrow shape with a tapered center portion in the longitudinal direction of the cross-section, and an oval or ellipse shape having a position substantially symmetrical to the center of gravity of the cross-section and having a substantially parallel portion.

From the viewpoint of improving the mechanical strength, the average fiber diameter of the glass fibers is preferably 6 to 20 μm, preferably 7 to 16 μm, more preferably 8 to 14 μm, and even more preferably 9 to 12 μm.

The average fiber length and average fiber diameter of the glass fibers can be measured by image analysis using an electron microscope method to measure the fiber length and fiber diameter of each of the 400 glass fibers arbitrarily selected, and can be obtained from the respective weight average values.

The average fiber length and average fiber diameter of the glass fibers in the polyester composition or in the LED reflector formed by the composition can be obtained by, for example, using a polyester composition or an LED in hexafluoroisopropanol. The reflecting plate was dissolved, and the glass fibers were taken out and obtained by image analysis using an electron microscope method in the same manner as described above.

    <Antioxidant (D)>    

The polyester composition of the present invention preferably contains an antioxidant (D). The antioxidant (D) is preferably one or more selected from the group consisting of a phenol-based antioxidant (D-1) and a phosphorus-based antioxidant (D-2), and a combination of a phenol-based antioxidant (D-1) and a phosphorus-based antioxidant Antioxidant (D-2) is preferred.

By containing the antioxidant (D), free radicals generated by heat or light can be trapped, and a decrease in the reflectance of the obtained reflecting plate can be suppressed.

The phenol-based antioxidant (D-1) (hereinafter also referred to as "(D-1) component") is preferably one or more selected from the group consisting of a semi-blocked or a fully-blocked phenol-based antioxidant. Thereby, the stability of the phenoxy radical generated after capturing the radical generated by heat or light is improved, and a decrease in the reflectance can be suppressed.

Examples of the semi-hindered phenolic antioxidant include 3,9-bis [2- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propanyloxy] -1,1 -Dimethylethyl] -2,4,8,10-tetraoxaspiro [5.5] undecane (trade name: Sumilizer GA-80, manufactured by Sumitomo Chemical Co., Ltd.), and the like.

Examples of the fully hindered phenol-based antioxidant include neopentaerythritol-methyl [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2,2-thio- Diethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], n-octadecyl-3- (3,5-di-tert-butyl-4 -Hydroxyphenyl) propionate, and N, N'-hexamethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propanamidin] and the like. Commercially available products include, for example, "IRGANOX1010", "IRGANOX1035", "IRGANOX1076", "IRGANOX1098" (trade names, all of which are made by BASF Japan).

Among these, from the viewpoint of improvement in reflectance and suppression of decrease in reflectance, it is selected from 3,9-bis [2- [3- (3-tert-butyl-4-hydroxy-5-methylbenzene) Propyl) propanyloxy] -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5.5] undecane (Sumilizer GA-80), neopentaerythritol-methyl [3- (3,5-Di-tert-butyl-4-hydroxyphenyl) propionate] (IRGANOX1010), 2,2-thio-diethylenebis [3- (3,5-di-tri Butyl-4-hydroxyphenyl) propionate] (IRGANOX1035), n-octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate (IRGANOX1076) And one or more of N, N'-hexamethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propanamine] (IRGANOX1098), preferably selected from 3,9-bis [2- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propanyloxy] -1,1-dimethylethyl] -2,4 , 8,10-Tetraoxaspiro [5.5] undecane (Sumilizer GA-80) and neopentaerythritol-tris [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propane Ester] (IRGANOX1010) is preferably one or more.

These phenolic antioxidants can be used alone or in combination of two or more.

As the phosphorus-based antioxidant (D-2) (hereinafter also referred to as "(D-2) component"), from the viewpoint of suppressing a decrease in the reflectance, it is one selected from the group consisting of a phosphite and a phosphinate The above is better.

By containing a phosphorus-based antioxidant (D-2), it is possible to decompose peroxides generated by heat or light and suppress a decrease in light reflectance. When used in combination with a phenol-based antioxidant (D-1), A reflecting plate having a high light reflectance and having a reduced reflectance even after being exposed to heat or light is obtained.

Examples of the phosphite-type phosphorus-based antioxidant include ginseng (2,4-di-tertiary-butylphenyl) phosphite and 3,9-bis (2,6-di-tertiary-butyl-4- (Methylphenoxy) -2,4,8,10-tetraoxa-3,9-diphosphaspiro [5.5] undecane, 3,9-bis (octadecyloxy) -2,4 , 8,10-tetraoxa-3,9-diphosphaspiro [5.5] undecane, 3,9-bis (2,4-di-tert-butylphenoxy) -2,4,8 , 10-tetraoxa-3,9-diphosphaspiro [5.5] undecane, 2,2'-methylenebis (4,6-di-tert-butylphenyl) 2-ethylhexyl Phosphite and so on. Examples of commercially available products include "IRGAFOS168" (trade name, made by BASF Japan (stock)), "ADEKASTAB (ADK STAB) PEP-36" (trade name, made by ADEKA (stock)), and "ADEKASTAB (ADK STAB)" "PEP-8" (trade name, ADEKA (stock) system), "ADEKASTAB (ADK STAB) PEP-24" (trade name, ADEKA (stock) system), "ADEKASTAB (ADK STAB) HP-10" (trade name, ADEKA (shares) system).

Examples of the phosphite-type phosphorus-based antioxidant include (2,4-di-tert-butylphenyl) -4,4'-biphenylphenyl phosphinate, and (2,4- Di-tertiary butyl-5-methylphenyl) -4,4'-biphenylphenyl phosphinate, etc. In order to improve the reflectance and suppress the decrease in the reflectance, 2,4-Di-tert-butylphenyl) -4,4'-biphenylphenyl phosphinate is preferred. Commercially available products include, for example, "Hostanox P-EPQ" (trade name, manufactured by Clariant Japan (Stock)), "GSY-P101" (trade name, manufactured by Sakai Chemical Industry (Stock)), and the like.

Among these, from the viewpoint of suppressing a decrease in the reflectance, it is selected from the group consisting of ginseng (2,4-di-tert-butylphenyl) phosphite ("IRGAFOS168") and (2,4-di -Tertiary butylphenyl) -4,4'-biphenylphenyl phosphinate ("Hostanox P-EPQ") Phenyl) -4,4'-biphenylphenyl phosphinate ("Hostanox P-EPQ") is more preferred.

These phosphorus-based antioxidants can be used alone or in combination of two or more.

When a phenol-based antioxidant (D-1) and a phosphorus-based antioxidant (D-2) are used in combination, as a suitable combination, from the viewpoint of improvement in reflectance and suppression of decrease in reflectance, it is selected from 3 , 9-bis [2- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propanyloxy] -1,1-dimethylethyl] -2,4, 8,10-tetraoxaspiro [5.5] deca-alkane (Sumilizer GA-80), neopentaerythritol-methyl [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid Esters] (IRGANOX1010), 2,2-thio-divinylbis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] (IRGANOX1035), n-octadecyl -3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate (IRGANOX1076), and N, N'-hexamethylenebis [3- (3,5-di-tri 1-Butyl-4-hydroxyphenyl) propanamine] (IRGANOX1098), and selected from the group consisting of ginseng (2,4-di-tertiary-butylphenyl) phosphite (IRGAFOS168) and (2) , 4-Di-tertiary-butylphenyl) -4,4'-biphenylphenyl phosphinate (Hostanox P-EPQ) is preferably selected from a combination of one or more, and is selected from 3,9-bis [2- [3- (3-tertiarybutyl-4-hydroxy-5-methylphenyl) propanyloxy] -1,1-dimethylethyl] -2,4,8,10- Tetraoxaspiro [5.5] undecane (Sumilizer GA-80) and neopentyl alcohol- [3- (3,5-Di-tertiary-butyl-4-hydroxyphenyl) propionate] (IRGANOX1010), one or more species, and (2,4-di-tertiary-butylphenyl)- A combination of 4,4'-biphenylphenyl phosphinate (Hostanox P-EPQ) is preferred.

    <Light stabilizer (E)>    

It is preferable that the polyester composition of the present invention further contains a light stabilizer (E) from the viewpoint of preventing discoloration of the obtained reflecting plate and suppressing a decrease in light reflectance.

Examples of the light stabilizer (E) include compounds having an ultraviolet absorbing effect such as diphenyl ketone compounds, salicylate compounds, benzotriazole compounds, acrylonitrile compounds, and other conjugate compounds, A compound having a radical trapping ability, such as a hindered amine-based compound. Especially from the viewpoint of high affinity with polyester (A) and improvement in heat resistance, a compound having a amide bond in its molecule is preferred. From the standpoint of obtaining a high stabilization effect, it is preferable to use a compound having an ultraviolet absorbing effect and a compound having a radical trapping ability in combination. These light stabilizers can be used alone or in combination of two or more.

    [Other ingredients]    

The polyester composition of the present invention may further contain (blended) aniline black or other organic or inorganic colorants; antistatic agents; crystallization nucleating agents such as talc; plasticizers; polyolefin waxes and higher fatty acids Waxes such as esters; Release agents such as silicone oil; Other ingredients such as lubricants.

When the polyester composition of the present invention contains (blended) other components, the content of the other components is preferably 5 parts by mass or less based on 100 parts by mass of the polyester (A).

    [Content of each component in the polyester composition]    

The content of the polyester (A) used in the present invention is preferably 40% by mass or more, and more preferably 45% by mass or more in the polyester composition from the viewpoint of improving the formability and heat resistance of the LED reflector. It is more preferably 50% by mass or more, and from the viewpoint of the mechanical strength of the obtained reflecting plate or a high reflectance, it is preferably 80% by mass or less, preferably 75% by mass or less, and more preferably 70% by mass %the following.

The content of the titanium oxide (B) used in the present invention is, from the viewpoint of obtaining high reflectance, 10 parts by mass or more, preferably 20 parts by mass or more, and more preferably 100 parts by mass of the polyester (A). 25 parts by mass or more, more preferably 30 parts by mass or more, and from the viewpoint of improving the formability and heat resistance of the LED reflector, it is 90 parts by mass or less, preferably 85 parts by mass or less, and more preferably 80 parts by mass The following.

The total content of the polyester (A) and the titanium oxide (B) in the polyester composition of the present invention is preferably 60 from the viewpoint of improving the formability and reflectance of the LED reflector and suppressing the decrease of the reflectance. It is preferably 70% by mass or more, more preferably 100% by mass or less, and more preferably 90% by mass or less.

The content of the reinforcing material (C) used in the present invention is preferably 5 parts by mass or more, and more preferably 10 parts by mass or more, based on 100 parts by mass of the polyester (A) from the viewpoint of improvement in heat resistance and mechanical strength. It is more preferably 15 parts by mass or more, and is preferably 50 parts by mass or less, and more preferably 40 parts by mass or less from the viewpoint of obtaining a high reflectance and suppressing a decrease in the reflectance.

The content of the antioxidant (D) used in the present invention is preferably 0.10 parts by mass or more relative to 100 parts by mass of the polyester (A) from the viewpoint of obtaining a high reflectance and suppressing a decrease in the reflectance. It is 0.20 parts by mass or more, more preferably 0.30 parts by mass or more, and from the viewpoint of suppressing a decrease in the reflectance caused by defects such as gas scorching caused by gas generated during molding, it is preferably 1.5 parts by mass or less, It is preferably 1.0 parts by mass or less, more preferably 0.80 parts by mass or less, still more preferably 0.60 parts by mass or less, still more preferably 0.40 parts by mass or less.

In the present invention, the mass ratio of the phenol-based antioxidant (D-1) to the phosphorus-based antioxidant (D-2) [(D-1) component / (D-2) component] is to satisfy the following Formula (I) is preferred.

0.20 ≦ mass ratio [(D-1) component / (D-2) component] ≦ 5.00 (I)

The mass ratio [(D-1) component / (D-2) component] is preferably 0.50 or more, more preferably 0.70 or more, from the viewpoint of obtaining a high reflectance and the viewpoint of suppressing a decrease in the reflectance. From the viewpoint of suppressing a decrease in the reflectance caused by a defect such as gas scorching caused by gas generated during molding, it is preferably 3.00 or less, preferably 2.00 or less, more preferably 1.50 or less, and even more preferably 1.00 or less .

The content of the light stabilizer (E) used in the present invention is preferably 0.10 parts by mass or more with respect to 100 parts by mass of the polyester (A) from the viewpoint of preventing discoloration of the obtained reflecting plate and suppressing a decrease in light reflectance. It is preferably 0.15 parts by mass or more, and from the viewpoint of cost reduction, it is preferably 2.0 parts by mass or less, preferably 1.2 parts by mass or less, and more preferably 0.8 parts by mass or less.

The polyester composition of the present invention can be prepared by mixing the aforementioned components according to a known method. Examples thereof include a method of adding each component during the polycondensation reaction of the polyester (A), a method of dry blending the polyester (A) with other components, and a method of melt-kneading the components using an extruder. Among these, the method of melt-kneading each component using an extruder is preferable from a viewpoint of being easy to handle and obtaining a uniform composition. The extruder used at this time is preferably a biaxial screw type, and the melt-kneading temperature is preferably within a range of 5 ° C to 350 ° C higher than the melting point of the polyester (A).

    [LED reflector]    

The LED reflecting plate of the present invention is obtained by forming the polyester composition of the polyester composition of the present invention as described above. As a molding method, a reflecting plate can be obtained by a molding method generally used for a thermoplastic resin composition, such as injection molding, extrusion molding, calendar molding, blow molding, calender molding, and cast molding. In addition, a reflecting plate can also be obtained by a molding method combining the above-mentioned molding methods. In particular, injection molding is preferred from the viewpoints of ease of molding, mass productivity, and cost reduction. In addition, in the LED reflecting plate of the present invention, the aforementioned polyester composition and other polymers can be compositely molded, and even the aforementioned polyester composition can be composited with a molded body or fabric made of metal or the like.

The LED reflecting plate of the present invention is characterized in that the reflectance of light having a wavelength of 460 nm using a spectrophotometer has a small decrease even after being exposed to heat or light, and can maintain a high level. For example, when the content of titanium oxide (B) is 33 parts by mass relative to 100 parts by mass of polyester (A), the amount of decrease in reflectance from the initial reflectance after short-term heating at 170 ° C for 5 hours, It is preferably 3.0% or less, more preferably 2.5% or less, and even more preferably 2.0% or less. Thereby, in the manufacturing process of an LED package, the fall of the reflectance after exposure to heat can be suppressed.

In addition, after long-term heating at 120 ° C for 600 hours, the decrease in reflectance from the initial reflectance is preferably 4.0% or less, preferably 3.5% or less, more preferably 3.0% or less, and even more preferably 2.5. %the following. Thereby, even if it is a long-term use environment, the reflection plate can suppress the fall of the reflectance.

The LED reflecting plate of the present invention uses an initial reflectance of light with a wavelength of 460 nm of a spectrophotometer. For example, when the content of titanium oxide (B) is 33 parts by mass relative to 100 parts by mass of polyester (A), it is preferably 92.0% or more, preferably 93.0% or more, and more preferably 94.0% or more.

The measurement of each reflectance and the calculation of the reduction amount are in accordance with the methods described in the examples.

In addition, for the LED reflecting plate of the present invention, for example, when the content of titanium oxide (B) is 33 parts by mass based on 100 parts by mass of polyester (A), it is measured using a spectrophotometer after being illuminated at 50 ° C for 24 hours. The reflectance of light having a wavelength of 460 nm is preferably 88.0% or more, preferably 88.5% or more, and more preferably 89.0% or more.

In addition, the above-mentioned illumination is performed by passing the light of the metal halide lamp in the air through a filter that can transmit light of 295 nm to 780 nm, and the illumination intensity at a wavelength of 300 to 400 nm is 10 mW / cm ² .

The measurement of the reflectance was performed according to the method described in the examples.

In particular, the LED reflecting plate of the present invention can maintain a high reflectance (reflection for light near a wavelength of 460 nm) even after being exposed to heat or light in the manufacturing process of the LED package or the use environment. . Therefore, the LED reflecting plate of the present invention is suitably used as a reflecting plate for LEDs used in, for example, backlight light sources, lighting fixtures, various lamps of automobiles, and the like, and the life of a light-emitting device including the LED reflecting plate of the present invention is extended.

    [Light emitting device]    

A light-emitting device according to the present invention includes the LED reflecting plate of the present invention. Examples of the light-emitting device of the present invention include a backlight light source, a light source for lighting, and a light source for various lamps of automobiles.

FIG. 1 shows an example of a typical structure of a light-emitting device of the present invention. FIG. 1 is a schematic view showing an SMD (surface mounted device) type light emitting device (LED device) 1. In the light-emitting device 1, the semiconductor light-emitting element 10 is disposed in a package-like portion 50 formed of a substrate 20 and a reflective plate (frame body) 30, and the package-like portion 50 is filled with a sealing member 40 (light-transmitting resin).

Hereinafter, each element of the light-emitting device of the present invention will be described. Incidentally, the light-emitting device of the present invention is not limited by the following elements.

    <Semiconductor light emitting element>    

The semiconductor light emitting element 10 is preferably used for a light emitting peak wavelength in a wavelength region of 500 nm or less. The semiconductor light emitting element is not limited to a single light emitting peak, and a semiconductor light emitting element having a plurality of light emitting peaks may be used. In the case of having a plurality of emission peaks, one or two or more emission peaks may be provided in a region having a longer wavelength than 500 nm. It is also possible to use a semiconductor light emitting element having a light emitting peak in a long wavelength region (501 nm to 780 nm) of visible light.

The structure of the semiconductor light emitting element 10 is not particularly limited as long as it has the above-mentioned wavelength characteristics. As the light emitting layer, for example, a semiconductor such as GaAlN, ZnS, ZnSe, SiC, GaP, GaAlAs, AlN, InN, AlInGaP, InGaN, GaN, or AlInGaN can be used.

In addition, the light emitting layer may be one containing an arbitrary dopant.

A plurality of semiconductor light emitting elements 10 can be used as appropriate. For example, two light-emitting elements that can emit green light and one light-emitting element that can emit blue light and red light can be set.

The method for connecting the semiconductor light emitting element 10 to the substrate 20 is not particularly limited, and a conductive epoxy or polysiloxane adhesive can be used. In addition, in order to efficiently transfer the heat generated by the semiconductor light emitting element to the substrate, a metal having a low melting point may be used. Examples include Sn / Ag / Cu (melting point 220 degrees), Sn / Au (melting point 282 degrees), and the like.

    <Package>    

The package is a member on which the semiconductor light emitting element 10 is mounted, and a part or the whole is formed by the LED reflecting plate of the present invention described above. A package can be composed of a single component or a combination of multiple components.

The package should preferably have a recess (cup). An example of the package includes a combination of a reflector (frame) and a substrate. For example, in FIG. 1, a reflector (frame) 30 having a desired shape is formed so as to form a recess (cup). A package is then formed on the substrate 20. The substrate 20 and the reflecting plate 30 are formed of the LED reflecting plate of the present invention molded from the polyester composition described above. Only one of the substrate 20 and the reflecting plate 30 may be formed of the LED reflecting plate of the present invention. When a plurality of the LED reflecting plates of the present invention are used as described above, LED reflecting plates having different characteristics obtained by changing the composition of the polyester composition to form the LED reflecting plates may be used in combination. As another example, there can be mentioned a configuration in which the above-mentioned polyester composition is formed so that a recessed portion (cup-shaped portion) is formed on one surface, and a package is formed by one LED reflector. As still another example, a package composed of only a flat LED reflector can be used.

The recess (cup-shaped portion) formed in the package refers to a space having a bottom portion and a side portion, and a shape having a cross-sectional area perpendicular to the optical axis from the bottom to the direction of light emission from the light emitting device continuously or stepwise. The parts that make up. As long as this condition is satisfied, the shapes of the bottom and side portions are not particularly limited.

    <Sealing member>    

The sealing member 40 is a member formed so as to cover the semiconductor light emitting element 10, and is mainly provided for the purpose of protecting the semiconductor light emitting element 10 from external environmental protection.

For the sealing member 40, a transparent thermosetting resin can be used for the purpose of protecting the semiconductor light emitting element 10 or wiring. Examples of the transparent thermosetting resin include a thermosetting resin containing epoxy or polysiloxane. Polysilicon can be used in resin, rubber, and colloid types according to the required characteristics of the package. In addition, in order to improve the adhesion between the reflecting plate 30 and the sealing member 40, the reflecting plate 30 may be treated with a rare gas plasma such as argon.

The sealing member 40 may be provided so that a plurality of layers made of different materials are laminated on the semiconductor light emitting element 10.

The sealing member 40 may include a phosphor. By using a phosphor, a part of the light from the semiconductor light emitting element 10 can be converted into light of a different wavelength, and the light emission color of the light emitting device can be changed or corrected.

Any phosphor can be used as long as the phosphor can be excited by light from the semiconductor light emitting element 10. It is suitable to use, for example, a nitride phosphor, an oxynitride phosphor, a silicon-aluminum oxynitride phosphor selected from a lanthanide group mainly activated by Eu, Ce, or the like; a lanthanide or Mn mainly composed of Eu and the like Alkaline earth metal aluminate phosphors, alkaline earth silicates, alkaline earth sulfides, alkaline earth thiogallates, alkaline earth silicon nitrides, and germanates activated by transition metal elements such as Ce; One or more rare earth aluminates and rare earth silicates activated by other lanthanides; or organic compounds and organic complexes activated mainly by lanthanides such as Eu.

The sealing member 40 may include a combination of a plurality of types of phosphors. In this case, a phosphor that emits light when excited by light from the semiconductor light emitting element 10 and a phosphor that emits light when excited by light from the phosphor may be used in combination.

When the sealing member 40 contains a light diffusing body such as titanium dioxide or zinc oxide, the diffusion of light in the sealing member 40 can be promoted and uneven light emission can be reduced.

The light-emitting device 1 of FIG. 1 is manufactured, for example, as follows. First, the reflecting plate 30 of the LED reflecting plate of the present invention is arranged on the substrate 20 of the LED reflecting plate of the present invention. Next, the semiconductor light emitting element 10 is fixed, and the electrodes of the semiconductor light emitting element 10 and the wiring pattern on the substrate 20 are connected by wires. Next, a liquid silicone sealant composed of a main agent and a hardener is prepared and potted into the cup-shaped portion. In this state, it is heated to about 150 ° C, and the polysiloxane sealant is thermally hardened. Then let it dissipate heat in the air.

Fig. 2 is a schematic view showing a light-emitting device 2 of the present invention having another structure. In FIG. 2, the same elements as those of the light-emitting device 1 are denoted by the same reference numerals. In the light emitting device 2, a lead frame 80 is used instead of the substrate, and the semiconductor light emitting element 10 is fixed to the lead frame 80. The other structures are the same as those of the light emitting device 1.

FIG. 3 is a schematic view showing a light-emitting device 3 of the present invention having another structure. In FIG. 3, the same elements as those of the light emitting device 1 are denoted by the same reference numerals. In the light-emitting device 3, the substrate 70 of the LED reflecting plate of the present invention is used. A desired wiring 71 is arranged on the substrate 70. In addition, after the semiconductor light emitting element 10 is fixed as shown in the figure without using a frame (reflective plate), the sealing member 60 can be formed by mold molding using a desired mold. Alternatively, a sealing member 60 formed in a desired shape in advance may be prepared, and the semiconductor light emitting element 10 may be covered on the substrate 70 so as to cover the semiconductor light emitting element 10.

As described above, the SMD light-emitting device has been described as a configuration example of the present invention. However, the present invention can also be applied to a semiconductor light-emitting element that is fixed to a lead frame having a cup portion, and a part of the semiconductor light-emitting element and the lead frame. A so-called cannonball type light emitting diode covered with a sealing member. It is also applicable to a flip-chip light-emitting device in which a semiconductor light-emitting element is fixed to a substrate or a lead frame in the form of a so-called flip-chip.

    [Example]    

Hereinafter, the present invention will be described in more detail using examples and comparative examples, but the present invention is not limited to the following examples.

In addition, each evaluation in an Example and a comparative example was performed according to the method shown below.

    (Melting point)    

The melting point of the polyester (A) is a melting peak that appears when the temperature is increased from 30 ° C to 350 ° C at a rate of 10 ° C / min in a nitrogen environment using a differential scanning calorimeter "DSC822" made by METTLER TOLEDO. The peak temperature was determined as the melting point (° C). When there are a plurality of melting peaks, the peak temperature of the melting peak at the highest temperature side is determined as the melting point.

    (Weight average molecular weight)    

The weight average molecular weight was measured by GPC under the following conditions.

Column: 2 TSKgel Super HM-N manufactured by Tosoh Corporation

Eluent: hexafluoroisopropanol (added with 0.085% by mass of sodium trifluoroacetate)

Flow: 0.4mL / min

Sample: 2.5 mg of polyester (A) was dissolved in 5 mL of a hexafluoroisopropanol solution (0.085 mass% of sodium trifluoroacetate was added) to prepare it.

Column temperature: 40 ℃

Detector: UV detector (measurement wavelength: 254nm)

Standard substance: polymethyl methacrylate

    (Ignition Loss)    

The titanium oxide (B) was previously heat-treated in a vacuum dryer at 120 ° C. for 2 hours to remove the attached moisture physically adsorbed on the surface. Next, in a vacuum dryer, the temperature was lowered to room temperature (23 ° C.) while maintaining a vacuum state, and then the mass of the titanium oxide (B) (hereinafter referred to as “mass α”) was measured. Next, the titanium oxide (B) was heat-treated in a vacuum dryer at 550 ° C. under normal pressure for 2 hours, and then brought into a vacuum state, and the temperature was lowered to room temperature (23 ° C.) while maintaining the vacuum state. The mass of titanium oxide (B) at this stage (hereinafter referred to as "mass β") was measured, and the loss on ignition was calculated from the following formula.

Loss on ignition (% by mass) = ((mass α-mass β) / mass α) × 100

In addition, the titanium oxide (B) was sampled 10 times, the above-mentioned measurement of the masses α and β, and the calculation of the loss on ignition were performed, and the average value was determined as the loss on ignition. The results are shown in Table 1.

    (Initial reflectance)    

Using the polyester compositions obtained in the examples and comparative examples, injection molding was performed at a cylinder temperature approximately 10 ° C higher than the melting point of the polyester (mold temperature: 140 ° C) to produce a thickness of 1 mm, a width of 40 mm, and a length of 100 mm. Test piece. The reflectance (initial reflectance) of light having a wavelength of 460 nm of this test piece was obtained with a spectrophotometer (U-4000) manufactured by Hitachi, Ltd. The results are shown in Table 1.

    (Amount of decrease in reflectance after short-term heating (1))    

Using the polyester compositions obtained in the examples and comparative examples, injection molding was performed at a cylinder temperature approximately 10 ° C higher than the melting point of the polyester (mold temperature: 140 ° C) to produce a thickness of 1 mm, a width of 40 mm, and a length of 100 mm. Test piece. This test piece was heat-treated in a hot-air dryer at 170 ° C for 5 hours. The reflectance (1) of light having a wavelength of 460 nm of the heat-treated test piece was obtained by a spectrophotometer (U-4000) manufactured by Hitachi, Ltd., and the reflection of light after short-term heating was obtained by the following formula. The rate of reduction (1). The results are shown in Table 1.

Decrease (1) (%) = (Initial reflectance (%))-(Reflectivity (1) (%))

    (Amount of decrease in reflectance after long-term heating (2))    

Using the polyester compositions obtained in the examples and comparative examples, injection molding was performed at a cylinder temperature approximately 10 ° C higher than the melting point of the polyester (mold temperature: 140 ° C) to produce a thickness of 1 mm, a width of 40 mm, and a length of 100 mm. Test piece. This test piece was heat-treated at 120 ° C. for 600 hours in a hot air dryer. The reflectance (2) of light with a wavelength of 460 nm of the heat-treated test piece was obtained by a spectrophotometer (U-4000) manufactured by Hitachi, Ltd., and the reflection of light after long-term heating was obtained from the following formula The rate of reduction (2). The results are shown in Table 1.

Reduction (2) (%) = (Initial reflectance (%))-(Reflectivity (2) (%))

    (Reflectivity after illumination)    

Using the polyester compositions obtained in the examples and comparative examples, injection molding was performed at a cylinder temperature approximately 10 ° C higher than the melting point of the polyester (mold temperature: 140 ° C) to produce a thickness of 1mm, a width of 40mm, and a length of 100mm Test piece. This test piece was set at a distance of 25 cm from the upper lamp irradiation surface of an ultraviolet irradiation device ("TOSCURE 401" manufactured by Toshiba Litech Co., Ltd., lamp: H400L / 2), and irradiation was performed at 50 ° C for 24 hours. The reflectance of light having a wavelength of 460 nm of the illuminated test piece was obtained with a spectrophotometer (U-4000) manufactured by Hitachi, Ltd. The results are shown in Table 1.

    (Formability)    

The polyester compositions obtained in the examples and comparative examples were dried at 110 ° C for 5 hours using a vacuum dryer, and then directly fed into the raw materials of an injection molding machine (made by Sumitomo Heavy Industries, Ltd., trade name: SE18DU). Supply port.

At a cylinder temperature of about 10 ° C higher than the melting point of polyester, it was allowed to stay in the cylinder for 3 minutes. The outflow state of the polyester composition from the nozzle tip was observed, and the injection moldability was evaluated according to the following evaluation criteria. The detailed temperature conditions are shown below.

    [Temperature conditions]    

Forming temperature: raw material supply port 290 ° C, cylinder temperature 300 ° C, nozzle tip 300 ° C

Metal mold temperature: 150 ℃

    [Evaluation benchmark]    

A: Even if it stays for 3 minutes, the molten polyester composition does not drip from the nozzle tip.

B: When left for 3 minutes, the molten polyester composition slightly droops from the nozzle tip.

C: If the molten polyester composition stays for 3 minutes, the dripping of the molten polyester composition from the tip of the nozzle is severe, and it is difficult to eject the molten polyester composition.

The components used in the examples and comparative examples are as follows.

    [Polyester (A)]    

． A-1: 100 mol% of dicarboxylic acid units are terephthalic acid units, and 100 mol% of diol units are 1,4-cyclohexanedimethanol units. (1,4-cyclohexanedimethanol trans isomer ratio: 70% by mass, melting point: 290 ° C, weight average molecular weight: 7,000)

    [Surface-coated titanium oxide (B)]    

． B-1: Titanium dioxide (manufactured by DuPont, trade name: R-105, TiO ₂ content: 92% by mass, inorganic treatment: alumina, silicon dioxide, organic treatment: yes)

． B-2: Titanium dioxide (made by Ishihara Industries, Ltd., trade name: CR-90, TiO ₂ content: 90% by mass, inorganic treatment: alumina, silicon dioxide)

． B-3: Titanium dioxide (made by Ishihara Industry Co., Ltd., trade name: PFC106, TiO ₂ content: 89% by mass, inorganic treatment: alumina, silicon dioxide, organic treatment: yes)

． B-4: Titanium dioxide (manufactured by DuPont, trade name: R-960, TiO ₂ content: 89% by mass, inorganic treatment: alumina, silicon dioxide)

． b-1: Titanium dioxide (manufactured by DuPont, trade name: R-350, TiO ₂ content: 95% by mass, inorganic treatment: alumina, silicon dioxide, organic treatment: yes)

． b-2: Titanium dioxide (made by Ishihara Industries, Ltd., trade name: CR-63, TiO ₂ content: 97% by mass, inorganic treatment: alumina, silicon dioxide, organic treatment: yes)

． b-3: Titanium dioxide (made by Ishihara Industry Co., Ltd., trade name: PFC107, TiO ₂ content: 88% by mass, inorganic treatment: alumina, silicon dioxide, organic treatment: yes)

． b-4: Titanium dioxide (made by Ishihara Industries, Ltd., trade name: PFC105, TiO ₂ content: 87% by mass, inorganic treatment: alumina, silicon dioxide, zirconium dioxide, organic treatment: yes)

． b-5: Titanium dioxide (manufactured by DuPont, trade name: R-931, TiO ₂ content: 80% by mass, inorganic treatment: alumina, silicon dioxide)

Table 1 shows the average particle size (catalog value) of each titanium oxide.

    [Reinforcing material (C)]    

． Glass fiber: made by Japan Electric Glass Co., Ltd., trade name: "T-176H", average fiber diameter 10.5 μm, average fiber length 3 mm, circular cross section

    [Antioxidant (D)]    

． D-1: N, N'-hexamethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propanamine] (manufactured by BASF Japan, trade name: (IRGANOX1098)

． D-2: Ginseng (2,4-di-tert-butylphenyl) phosphite (made by BASF Japan (stock), trade name: IRGAFOS168)

    [Light stabilizer (E)]    

． N, N'-bis (2,2,6,6-tetramethyl-4-piperidinyl) -1,3-xylylenediamine (manufactured by Clariant Japan), trade name: Nylostab S-EED )

    [Other ingredients]    

． Release agent: Polypropylene decomposition type (Mitsui Chemical Co., Ltd., trade name: HI-WAX NP055)

． Nuclear agent: Talc (made by Fuji Talc Industries, Ltd., trade name: Talc PKP80)

    Examples 1 to 4 and Comparative Examples 1 to 5    

With respect to 100 parts by mass of the polyester (A-1), 33 parts by mass of each of the titanium oxide (B), 0.50 parts by mass of the release agent, 0.17 parts by mass of the core agent, and the phenolic antioxidant (D-1 ) 0.17 parts by mass, 0.17 parts by mass of the above-mentioned phosphorus-based antioxidant (D-2), and 0.17 parts by mass of the above-mentioned light stabilizer (E), and the obtained mixture was subjected to a biaxial extruder (screw diameter: 32 mm). (L / D = 30, rotation speed 150 rpm), while adding 33 parts by mass of the reinforcing material (C) from a side feeder, melt-kneaded at 300 ° C, extruded into strands, and then granulated Machine cutting to obtain a granular polyester composition. Using the obtained polyester composition, a test piece having a predetermined shape was produced and used for evaluation. The results are shown in Table 1.

As shown in Table 1, the polyester compositions of Examples 1 to 4 are more excellent in moldability than Comparative Examples 1 to 5 and have higher initial reflectances. Even after heat treatment, the The decrease in the reflectance of light at 460 nm is also small. In addition, the reflectance of light having a wavelength of 460 nm after irradiating light in the ultraviolet wavelength range was 88% or more. From these results, it can be seen that by using the polyester composition of the present invention, excellent formability can be obtained, and even in the manufacturing process of the LED package or the use environment, the reflectance does not decrease, and LED reflection with good optical characteristics is obtained. board. In addition, a light-emitting device provided with the reflecting plate and a lighting fixture provided with the light-emitting device can achieve excellent optical characteristics and long life.

    [Industrial availability]    

According to the present invention, it is possible to provide a polyester composition for an LED reflecting plate, which has excellent moldability, and even after being exposed to heat or light, the reflectance is reduced little, and a high reflectance can be maintained; The LED reflecting plate constituted; and a light emitting device provided with the reflecting plate. The polyester composition of the present invention is particularly suitable for an LED reflector for a lighting fixture.

Claims (8)

    A polyester composition for an LED reflecting plate, wherein the polyester composition contains polyester (A) and a surface-coated titanium oxide (B), and in the polyester (A), 50 moles of a structural unit derived from a dicarboxylic acid is used. More than one ear% is a structural unit derived from terephthalic acid, and more than 50 mole% of a structural unit derived from a diol is a structural unit derived from 1,4-cyclohexanedimethanol; the titanium oxide (B) starts with Heat treatment at 120 ° C for 2 hours in advance, and Ignition Loss caused by the main heating during the main heating treatment at 550 ° C for 2 hours is 0.50 ~ 1.20% by mass; the content of the titanium oxide (B) is relatively The polyester (A) is 10 to 90 parts by mass based on 100 parts by mass.         For example, the polyester composition for an LED reflecting plate of claim 1, wherein the polyester (A) is 75 to 100 mol% derived from a structural unit of a dicarboxylic acid and is a structural unit derived from a terephthalic acid, and 75 to 100 mol% of the structural unit of the alcohol is poly (dimethyl terephthalate) derived from the structural unit of 1,4-cyclohexanedimethanol.         For example, the polyester composition for an LED reflecting plate according to claim 1 or 2 further contains 5 to 50 parts by mass of a reinforcing material (C) based on 100 parts by mass of the polyester (A).         The polyester composition for an LED reflecting plate according to claim 3, wherein the reinforcing material (C) is glass fiber.         The polyester composition for an LED reflecting plate according to any one of claims 1 to 4, further comprising 0.10 to 1.0 part by mass of an antioxidant (D) based on 100 parts by mass of the polyester (A).         The polyester composition for LED reflectors according to any one of claims 1 to 5, further comprising a light stabilizer (E).         An LED reflecting plate comprising the polyester composition for an LED reflecting plate according to any one of claims 1 to 6.         A light-emitting device is provided with the LED reflecting plate as claimed in claim 7.