JP2018162354A - Polyester resin composition for reflector and reflector using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition capable of providing a reflector excellent in flowability during molding processing, further hardly reducing reflection coefficient even when exposed to a high temperature and high in strength.SOLUTION: A polyester resin for reflector contains a polyester resin having melting point or glass transition temperature of 250°C or more (A) of 30 to 80 mass%, an inorganic filler (B) of 1 to 50 mass%, a white pigment (C) of 5 to 50 mass%, an oxycarboxylic acid metal salt (D) of 0.1 to 2.0 mass%, wherein total of the polyester resin (A), the inorganic filler (B), the white pigment (C) and the oxycarboxylic acid metal salt (D) is 100 mass%.SELECTED DRAWING: None

Description

  The present invention relates to a polyester resin composition for a reflector, and a reflector using the same.

  Light sources such as light-emitting diodes (LEDs) and organic ELs are widely used in lighting, display backlights, and the like, taking advantage of their features (for example, low power and long life). In order to efficiently use light from these light sources, reflectors are used in various aspects.

  For example, the LED element includes a housing part formed on a substrate and having a space for mounting the LED, the LED mounted in the space, and a sealing member for sealing the LED. For example, such an LED element includes 1) a step of manufacturing a housing part by molding a reflecting material on a substrate, and 2) an LED is disposed inside the housing part, and the LED and the substrate are electrically connected. And 3) the LED is manufactured through a step of sealing the LED with a sealant. In said 3) sealing process, in order to thermoset the said sealing agent, a housing, LED, a sealing material, etc. are heated to the temperature of 100-200 degreeC. Further, in the above 2) LED mounting process, a reflow soldering process or the like is performed in order to mount the LED on the substrate. In this case as well, the reflective material is exposed to a temperature of 250 ° C. or higher. The reflective material is required to maintain the reflectance even after such a temperature. Further, the reflective material is required to maintain the reflectance even when exposed to heat or light generated in the use environment (for example, heat or light generated from the LED) for a long period of time.

  In order to satisfy the above requirements, conventionally, the use of a heat-resistant polyester such as polycyclohexylene dimethylene terephthalate (PCT) as a material for the reflector has been studied (Patent Document 1). Patent Document 1 discloses a resin composition containing polyester such as PCT, an inorganic filler, a white pigment, and a nucleating agent. Patent Document 1 describes that, when the heat-resistant polyester resin composition contains a core crystallizing agent composed of a metal salt of an organic acid, the reflectance at a high temperature is increased.

JP-T-2006-50459

  However, the heat-resistant polyester resin composition described in Patent Document 1 has insufficient fluidity during molding. Furthermore, there is also a problem that the reflectance after heating tends to decrease. In other words, it is possible to maintain a high reflectivity even when exposed to high temperatures, and it is possible to produce a reflective material having high strength, and it has not been possible to obtain a resin composition with excellent fluidity during processing. Met.

  The present invention has been made in view of the above circumstances. That is, the present invention provides a polyester resin composition for a reflector that is excellent in fluidity during molding processing, is less likely to have a low reflectance even when exposed to high temperatures, and can obtain a reflector having high strength. Objective.

That is, the first of the present invention relates to the following polyester resin composition for reflectors.
[1] 30 to 80% by mass of a polyester resin (A) having a melting point or glass transition temperature of 250 ° C. or higher, 1 to 50% by mass of an inorganic filler (B), and 5 to 50% by mass of a white pigment (C) Oxycarboxylic acid metal salt (D) 0.1-2.0% by mass (however, the polyester resin (A), the inorganic filler (B), the white pigment (C), and the oxycarboxylic acid metal) A total of the salt (D) is defined as 100% by mass).

[2] The polyester resin composition for a reflector according to [1], wherein the metal salt of oxycarboxylic acid (D) is a metal salt of 12-hydroxystearic acid.
[3] The polyester resin (A) includes a dicarboxylic acid component unit (a1) derived from a dicarboxylic acid and a dialcohol component unit (a2) derived from a dialcohol, wherein the dicarboxylic acid component unit (a1) 30 to 100 mol% of component units derived from an acid and 0 to 70 mol% of component units derived from an aromatic dicarboxylic acid other than terephthalic acid, and the dialcohol component unit (a2) has 4 to 20 carbon atoms. The polyester resin composition for a reflector according to [1] or [2], comprising a component unit derived from an alicyclic dialcohol having an alicyclic hydrocarbon skeleton and / or a component unit derived from an aliphatic dialcohol. object.

[4] The polyester resin composition for reflector according to [3], wherein the dialcohol component unit (a2) includes a component unit derived from an alicyclic dialcohol having a cyclohexane skeleton.
[5] The dialcohol component unit (a2) includes 30 to 100 mol% of component units derived from 1,4-cyclohexanedimethanol and 0 to 70 mol% of component units derived from the aliphatic dialcohol. [3] or the polyester resin composition for reflectors according to [4].
[6] The polyester resin composition for a reflector according to any one of [1] to [5], wherein the white pigment (C) is titanium oxide.

2nd of this invention is related with the following reflective materials.
[7] A reflector comprising a molded product of the polyester resin composition for reflectors according to any one of [1] to [6].
[8] The reflective material according to [7], which is a reflective material for a light-emitting diode element.

  The polyester resin composition for a reflector of the present invention is excellent in fluidity during molding. Moreover, according to the said polyester resin composition for reflectors, even if it exposes to high temperature, a reflectance cannot fall easily and it is possible to obtain a reflector with high intensity | strength.

1. About the polyester resin composition for reflectors The polyester resin composition for reflectors of the present invention (hereinafter also simply referred to as “resin composition”) is a composition for producing reflectors for various lighting and display elements. .

  As described above, it has been conventionally studied to obtain various reflectors by molding a resin composition containing a polyester resin, an inorganic filler, a white pigment, a carboxylic acid metal salt, and the like. However, the resin composition has problems such as insufficient fluidity during molding. Although the carboxylic acid metal salt contained in the resin composition has high crystallinity and acts as a crystal nucleating agent, the carboxylic acid metal salt has a relatively low polarity and may not be sufficiently compatible with the polyester resin. . Therefore, it is guessed that it was difficult to improve the fluidity of the resin composition. Moreover, in the reflective material obtained from the resin composition containing the said carboxylic acid metal salt, the reflectance after a heating was easy to fall.

On the other hand, the resin composition of the present invention includes a polyester resin (A), an inorganic filler (B), a white pigment (C), and an oxycarboxylic acid metal salt (D) in a predetermined ratio. The oxycarboxylic acid metal salt (D) has a carboxyl group and a hydroxyl group in one molecule. Therefore, it has a very high affinity with the polyester resin (A) and is easily dispersed uniformly in the polyester resin (A). And the fluidity at the time of processing of a resin composition becomes favorable because the oxycarboxylic acid metal salt (D) uniformly disperse | distributed to the polyester resin (A) acts as a lubricant in this way. On the other hand, the oxycarboxylic acid metal salt (D) has a relatively high crystallinity and also acts as a crystal nucleating agent. As a result, the crystallinity of the polyester resin (A) is moderately increased, and the strength of the resulting reflector is increased. Furthermore, oxycarboxylic acid metal salt (D) easily traps oxygen due to its structure, and also functions as an antioxidant. By the oxycarboxylic acid metal salt (D) acting as an antioxidant, discoloration when the resin composition or the reflective material is heated is suppressed. As a result, even when the reflective material is exposed to a high temperature, the decrease in reflectance is reduced, and the reflectance can be maintained high over a long period of time.
Hereinafter, each component contained in the resin composition will be described.

1-1. Polyester resin (A)
The polyester resin (A) has a plurality of ester structures represented by-(C = O) -O- in the molecule, and has a melting point (Tm) or glass transition temperature measured by a differential scanning calorimeter (DSC). If (Tg) is 250 degreeC or more, the kind will not be specifically limited. The resin composition of the present invention may contain only one type of polyester resin (A) or two or more types of polyester resins.

  From the viewpoint of further improving the heat resistance of the reflective material obtained from the resin composition, the polyester resin (A) comprises a dicarboxylic acid component unit (a1) having a component unit derived from an aromatic dicarboxylic acid, and an alicyclic hydrocarbon. And a dialcohol component unit (a2) having a component unit derived from an alicyclic dialcohol having a skeleton or an aliphatic dialcohol.

  From the viewpoint of further improving the heat resistance of the reflector obtained from the resin composition, the dicarboxylic acid component unit (a1) contains 30 to 100 mol% of a component unit derived from terephthalic acid, and an aromatic dicarboxylic acid other than terephthalic acid. It is preferable that the component unit derived from an acid is contained in an amount of 0 to 70 mol%. The ratio of the component unit derived from terephthalic acid contained in the dicarboxylic acid component unit (a1) is more preferably 40 to 100 mol%, and further preferably 60 to 100 mol%. When the content of the component unit derived from terephthalic acid is high, the heat resistance of the reflector is increased. The proportion of the component unit derived from the aromatic dicarboxylic acid other than terephthalic acid contained in the dicarboxylic acid component unit (a1) is more preferably 0 to 60 mol%, and more preferably 0 to 40 mol%. .

  In this specification, the component unit derived from terephthalic acid includes not only the component unit derived from terephthalic acid but also the component unit derived from terephthalic acid ester. The number of carbon atoms contained in the ester group of the terephthalic acid ester is preferably 1 to 4, and examples of the terephthalic acid ester include dimethyl terephthalate.

  On the other hand, the component unit derived from the aromatic dicarboxylic acid other than the terephthalic acid includes not only the component unit derived from the aromatic dicarboxylic acid but also the component unit derived from the ester. Here, preferable examples of the aromatic dicarboxylic acid other than terephthalic acid include isophthalic acid, 2-methylterephthalic acid, naphthalenedicarboxylic acid and the like. In addition, it is preferable that the carbon number which the ester group of the said aromatic dicarboxylic acid contains is 1-4 respectively. Further, the resin composition may contain only one type of component unit derived from an aromatic dicarboxylic acid other than terephthalic acid, or may contain two or more types.

  The total amount of the component unit derived from terephthalic acid and the component unit derived from an aromatic dicarboxylic acid other than terephthalic acid is preferably 100 mol%. However, depending on the desired properties, the dicarboxylic acid component unit (a1) is a component unit derived from a small amount of an aliphatic dicarboxylic acid or a component unit derived from a polyvalent carboxylic acid having three or more carboxylic acid groups in the molecule. May further be included. The total proportion of the component units derived from the aliphatic dicarboxylic acid and the component units derived from the polyvalent carboxylic acid contained in the dicarboxylic acid component unit (a1) is preferably 10 mol% or less.

  The number of carbon atoms of the component unit derived from the aliphatic dicarboxylic acid is not particularly limited, but is preferably 4 to 20, and more preferably 6 to 12. Examples of the aliphatic dicarboxylic acid include adipic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, undecanedicarboxylic acid, and dodecanedicarboxylic acid. Of these aliphatic dicarboxylic acids, adipic acid is preferred.

  Examples of the component unit derived from the polyvalent carboxylic acid include tribasic acids including trimellitic acid and pyromellitic acid, and polybasic acids.

  On the other hand, the dialcohol component unit (a2) is a component unit derived from an alicyclic dialcohol having 4 to 20 carbon atoms, or an aliphatic diester, from the viewpoint of further improving the heat resistance of the reflector obtained from the resin composition. It is preferable that the component unit derived from alcohol is included.

  When the dialcohol component unit (a2) includes a component unit derived from the alicyclic dialcohol, the heat resistance of the reflector is increased and the water absorption is reduced. Examples of the alicyclic dialcohol include dialcohols having an alicyclic hydrocarbon skeleton having 4 to 20 carbon atoms such as 1,3-cyclopentanediol, 1,3-cyclopentanedimethanol, 1,4 -Cyclohexanediol, 1,4-cyclohexanedimethanol, 1,4-cycloheptanediol, 1,4-cycloheptanedimethanol and the like are included. Among these, from the viewpoints of improving the heat resistance of the reflector, reducing water absorption, and being easily available, the alicyclic dialcohol is preferably a compound having a cyclohexane skeleton. More preferred is cyclohexanedimethanol.

  The alicyclic dialcohol has isomers such as a cis / trans structure. From the viewpoint of further improving the heat resistance of the reflecting material obtained from the resin composition, the polyester resin (A) is an alicyclic ring having a trans structure. It is preferable that more component units derived from the group dialcohol are included. Therefore, the cis / trans ratio of the component unit derived from the alicyclic dialcohol is preferably 50/50 to 0/100, more preferably 40/60 to 0/100.

  On the other hand, when the dialcohol component unit (a2) contains a component unit derived from an aliphatic dialcohol, the melt fluidity of the resin composition is increased. Examples of the aliphatic dialcohol include ethylene glycol, trimethylene glycol, propylene glycol, tetramethylene glycol, neopentyl glycol, hexamethylene glycol and dodecamethylene glycol.

  The dialcohol component unit (a2) is derived from the component unit derived from the alicyclic dialcohol (preferably a component unit derived from a dialcohol having a cyclohexane skeleton, more preferably derived from 1,4-cyclohexanedimethanol. Component unit) is preferably contained in an amount of 30 to 100 mol%, and the component unit derived from the aliphatic dialcohol is preferably contained in an amount of 0 to 70 mol%. A component unit derived from an alicyclic dialcohol contained in a dialcohol component unit (a2) (preferably a component unit derived from a dialcohol having a cyclohexane skeleton, more preferably derived from 1,4-cyclohexanedimethanol. The proportion of the component unit is more preferably 50 to 100 mol%, and further preferably 60 to 100 mol%. The ratio of the component unit derived from the aliphatic dialcohol contained in the dialcohol component unit (a2) is more preferably 0 to 50 mol%, and further preferably 0 to 40 mol%.

  The total amount of the component unit derived from the alicyclic dialcohol and the component unit derived from the aliphatic dialcohol is preferably 100 mol%. However, according to desired characteristics, the dialcohol component unit (a2) may further contain a component unit derived from a small amount of an aromatic dialcohol together with the component unit. Examples of the aromatic dialcohol include bisphenol, hydroquinone, and 2,2-bis (4-β-hydroxyethoxyphenyl) propane. The proportion of the component units derived from the aromatic dialcohol contained in the dialcohol component unit (a2) is preferably 10 mol% or less.

  The melting point (Tm) or glass transition temperature (Tg) of the polyester resin (A) measured by a differential scanning calorimeter (DSC) is 250 ° C. or higher. The lower limit of the melting point (Tm) or the glass transition temperature (Tg) is preferably 270 ° C., more preferably 280 ° C. or more, and further preferably 290 ° C. On the other hand, the preferable upper limit value of the melting point (Tm) or the glass transition temperature (Tg) is not particularly limited, but is, for example, 350 ° C., and more preferably 335 ° C. When the melting point or glass transition temperature is 250 ° C. or higher, discoloration or deformation of the reflective material in the reflow soldering process is suppressed. Further, it is preferable that the melting point or glass transition temperature is 350 ° C. or lower because it is not necessary to excessively increase the temperature during processing of the resin composition, and decomposition of other components in the resin composition is suppressed. In addition, melting | fusing point should just be 250 degreeC, when a polyester resin (A) has both melting | fusing point (Tm) and glass transition temperature (Tg).

  The melting point (Tm) and glass transition temperature (Tg) of the polyester resin (A) can be measured with a differential scanning calorimeter (DSC) according to JIS-K7121. Specifically, X-DSC7000 (made by SII) is prepared as a measuring apparatus. A pan for DSC measurement in which a sample of the polyester resin (A) is sealed is set in this apparatus, and the temperature is raised to 330 ° C. at a temperature rising rate of 10 ° C./min in a nitrogen atmosphere. And after hold | maintaining at the temperature for 5 minutes, it is made to temperature-fall to 23 degreeC by the temperature-fall measurement of 10 degreeC / min. The temperature at the top of the endothermic peak at the time of temperature rise is defined as the “melting point”. In addition, the temperature at the intersection of the straight line obtained by extending the base line on the low temperature side to the high temperature side and the tangent line drawn at the point where the slope of the step change part of the glass transition is maximized is called “glass transition temperature”. To do.

  Here, the intrinsic viscosity [η] of the polyester resin (A) is preferably 0.3 to 1.2 dl / g. When the intrinsic viscosity is in the above range, the fluidity during molding of the resin composition is increased. The intrinsic viscosity of the polyester resin (A) can be adjusted by the molecular weight of the polyester resin (A). Examples of the method for adjusting the molecular weight of the polyester resin (A) include known methods including a method for adjusting the degree of progress of the polycondensation reaction and a method for adding an appropriate amount of a monofunctional carboxylic acid or a monofunctional alcohol. .

The intrinsic viscosity of the polyester resin (A) can be measured by the following procedure.
The polyester resin (A) is dissolved in a 50/50 mass% mixed solvent of phenol and tetrachloroethane to obtain a sample solution. The flow down time of the obtained sample solution is measured under the condition of 25 ° C. ± 0.05 ° C. using an Ubbelohde viscometer, and the intrinsic viscosity [η] is calculated by applying the following equation.
[Η] = ηSP / [C (1 + kηSP)]

In the above formula, each algebra or variable represents the following.
[Η]: Intrinsic viscosity (dl / g)
ηSP: specific viscosity C: sample concentration (g / dl)
k: Constant (slope obtained by measuring the specific viscosity of samples having different solution concentrations (three or more points), plotting the solution concentration on the horizontal axis, and ηsp / C on the vertical axis)

The above ηSP is obtained by the following equation.
ηSP = (t−t0) / t0

In the above formula, each variable represents the following.
t: Number of seconds that the sample solution flows (seconds)
t0: The number of seconds during which the solvent flows (seconds)

  The polyester resin (A) may be produced by a known method, or a commercially available product may be purchased. The polyester resin (A) can be produced, for example, by blending a molecular weight regulator or the like in the reaction system and reacting the dicarboxylic acid component unit (a1) with the dialcohol component unit (a2). The intrinsic viscosity of the polyester resin (A) can be adjusted by blending a molecular weight modifier in the reaction system.

  Examples of the molecular weight modifier include monocarboxylic acids and monoalcohols. Examples of the monocarboxylic acid include aliphatic monocarboxylic acids having 2 to 30 carbon atoms, aromatic monocarboxylic acids, and alicyclic monocarboxylic acids. The aromatic monocarboxylic acid and the alicyclic monocarboxylic acid may have a substituent in the cyclic structure portion. Examples of the aliphatic monocarboxylic acids include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecylic acid, myristic acid, palmitic acid, stearic acid, oleic acid and linoleic acid . Examples of the aromatic monocarboxylic acid include benzoic acid, toluic acid, naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid and phenylacetic acid. Examples of the alicyclic monocarboxylic acid include cyclohexanecarboxylic acid.

  The addition amount of the molecular weight modifier is 0 to 0.07 with respect to 1 mol of the total amount of the dicarboxylic acid component unit (a1) when the dicarboxylic acid component unit (a1) and the dialcohol component unit (a2) are reacted. It is preferably a mole, more preferably 0 to 0.05 mole.

  The content of the polyester resin (A) in the resin composition of the present invention is 100 mass of the total of the polyester resin (A), the inorganic filler (B), the white pigment (C), and the oxycarboxylic acid metal salt (D). %, It is 30 to 80% by mass. As for content of the said polyester resin (A), it is more preferable that it is 30-70 mass%, and it is further more preferable that it is 40-60 mass%. When the content of the polyester resin (A) is within the above range, a reflective material having heat resistance sufficient to withstand the reflow soldering process is easily obtained without impairing moldability.

1-2. Inorganic filler (B)
The inorganic filler (B) is a filler made of an inorganic compound having a spherical shape, a fiber shape, a plate shape, or the like. From the viewpoint of further increasing the strength and toughness of the resin composition, the shape of the inorganic filler (B) is preferably fibrous.

  Examples of fibrous inorganic fillers (B) include glass fiber, wollastonite, potassium titanate whisker, calcium carbonate whisker, aluminum borate whisker, magnesium sulfate whisker, sepiolite, zonotlite, zinc oxide whisker, milled fiber and Cut fiber is included. The resin composition may contain only one kind or two or more kinds. Of these, wollastonite, glass fiber, and potassium titanate whisker are preferable, and wollastonite or glass fiber is more preferable because the average fiber diameter is relatively small and the surface smoothness of the molded product is easily improved. Wollastonite is preferable from the viewpoint of further enhancing the light shielding effect of the reflecting material obtained from the resin composition, and glass fiber is preferable from the viewpoint of further increasing the mechanical strength of the reflecting material.

  The average fiber length (l) of the fibrous inorganic filler (B) is usually 5 mm or less. When the average fiber length is 5 mm or less, the fibrous inorganic filler (B) is hardly broken. Moreover, the extra stress which resin receives at the time of shaping | molding can be decreased by finely disperse | distributing the inorganic filler (B) which has such an average fiber length in resin. The lower limit of the preferable length (fiber length) of the average fiber length (l) is 15 μm, preferably 30 μm, and more preferably 50 μm. On the other hand, a preferable upper limit is 10 mm, more preferably 8 mm, still more preferably 6 mm, and particularly preferably 5 mm. Particularly in the case of glass fiber, the preferred lower limit is 500 μm, more preferably 700 μm, and even more preferably 1 mm.

  From the viewpoint of facilitating fine dispersion of the fibrous inorganic filler (B), the average fiber diameter (d) of the fibrous inorganic filler (B) is preferably 0.05 to 30 μm, It is more preferable that it is 2-6 micrometers. When the average fiber diameter (d) is increased, the fibrous inorganic filler (B) is not easily broken during molding or the like, and the strength of the reflective material is increased. Moreover, when the average fiber diameter (d) is sufficiently large, the fibrous inorganic filler (B) is likely to be finely dispersed and the reflectance is increased.

The average fiber length (l) and the average fiber diameter (d) of the fibrous inorganic filler (B) in the resin composition (for example, a compound such as pellets) are measured by the following methods.
1) After the resin composition is dissolved in a hexafluoroisopropanol / chloroform solution (0.1 / 0.9% by volume), a filtrate obtained by filtration is collected.
2) Observe 100 of the above fibrous inorganic fillers (B) of the obtained filtrated material with a scanning electron microscope (SEM) (magnification: 50 times), and determine the length and diameter of each fiber. measure. The average fiber length is defined as the average fiber length (l), and the average fiber diameter is defined as the average fiber diameter (d).

  The aspect ratio (l / d) obtained by dividing the average fiber length (l) by the average fiber diameter (d) is preferably 2 to 20, and more preferably 7 to 12. The greater the aspect ratio, the higher the strength and rigidity of the reflector.

  The cross-sectional shape of the inorganic filler (B) is not particularly limited, and may be any shape such as a true circle, an oval, an eyebrow, and a rectangle. The cross section of the inorganic filler (B) is a cross section when the fiber is cut in the direction perpendicular to the length direction of the inorganic filler. When the fluidity of the resin composition, the low warpage of the obtained reflecting material, and the like are further required, the cross-sectional shape of the inorganic filler (B) is preferably an eyebrows shape or an oval shape.

  The major axis and minor axis of the cross section of the inorganic filler (B) are determined as follows. The resin component is dissolved and removed from the resin composition containing the inorganic filler (B) and the reflective material in the same manner as described above. The inorganic filler (B) may be separated by baking the resin composition or the reflective material. And the cross-sectional shape of an inorganic filler (B) is observed for the isolate | separated inorganic filler (B) using an optical microscope or an electron microscope.

  The content of the inorganic filler (B) in the resin composition of the present invention is 100 in total of the polyester resin (A), inorganic filler (B), white pigment (C), and oxycarboxylic acid metal salt (D). When it is defined as mass%, it is 1 to 50 mass%. It is preferable that content of the said inorganic filler (B) is 5-50 mass%, and it is more preferable that it is 5-40 mass%. When the content of the inorganic filler (B) is 1% by mass or more, the heat resistance of the reflective material obtained from the resin composition is likely to increase, and the surface is likely to be smooth. On the other hand, when the content of the inorganic filler (B) is 50% by mass or less, the fluidity of the resin composition is increased and the moldability is hardly impaired.

1-3. White pigment (C)
The white pigment (C) may be any pigment that can whiten the reflective material obtained from the resin composition and improve the light reflection function, but preferably has a refractive index of 2.0 or more. The upper limit value of the refractive index of the white pigment (C) is, for example, 4.0. Examples of the white pigment (C) include titanium oxide, zinc oxide, zinc sulfide, lead white, zinc sulfate, barium sulfate, calcium carbonate, and alumina oxide. The resin composition may contain only one type of white pigment (C), or may contain two or more types.

  The white pigment (C) is preferably titanium oxide from the viewpoint of further improving the reflectivity and concealability of the reflector obtained from the resin composition. The titanium oxide is preferably a rutile type.

  The white pigment (C) may be treated with a silane coupling agent or a titanium coupling agent. For example, the white pigment (C) may be surface-treated with a silane compound containing vinyltriethoxysilane, 2-aminopropyltriethoxysilane, and 2-glycidoxypropyltriethoxysilane.

  From the viewpoint of making the reflectance of the reflector obtained from the resin composition of the present invention more uniform, the white pigment (C) preferably has a small aspect ratio, that is, a spherical shape.

  From the viewpoint of further increasing the reflectance of the reflective material obtained from the resin composition of the present invention, the average particle size of the white pigment (C) is preferably 0.1 μm or more and 0.5 μm or less, preferably 0.15 μm or more. More preferably, it is 0.3 μm or less. The average particle size of the white pigment (C) is a distribution curve obtained by plotting the particle amount (%) in each particle size interval of primary particles using an image diffraction apparatus (Luzex IIIU) based on a transmission electron micrograph. Ask for. Then, a cumulative distribution curve is obtained from the obtained distribution curve, and a value at a cumulative degree of 50% in this cumulative distribution curve can be set as the average particle diameter.

  The content of the white pigment (C) in the resin composition of the present invention is 100% by mass of the total of the polyester resin (A), the inorganic filler (B), the white pigment (C), and the oxycarboxylic acid metal salt (D). When it is, it is 5-50 mass%. The content of the white pigment (C) is preferably 10 to 50% by mass, more preferably 10 to 40% by mass, and further preferably 10 to 37% by mass. When the content of the white pigment (C) is 5% by mass or more, the whiteness of the reflective material obtained from the resin composition tends to increase, and the reflectance tends to increase. On the other hand, when the content of the white pigment (C) is 50% by mass or less, the fluidity of the resin composition is easily increased and the moldability is improved.

1-4. Metal salt of oxycarboxylic acid (D)
The oxycarboxylic acid metal salt (D) is not particularly limited as long as it is a compound having a carboxyl group and a hydroxyl group and can improve the fluidity during processing of the resin composition. The oxycarboxylic acid metal salt (D) may be either an aliphatic oxycarboxylic acid metal salt or an aromatic oxycarboxylic acid metal salt. The resin composition may contain only one kind of oxycarboxylic acid metal salt (D), or may contain two or more kinds.

  The aliphatic oxycarboxylic acid constituting the oxycarboxylic acid metal salt (D) preferably contains an aliphatic oxycarboxylic acid having 10 to 30 carbon atoms. Specific examples thereof include α-hydroxymyristic acid, α-hydroxypalmitic acid, α-hydroxystearic acid, α-hydroxyeicosanoic acid, α-hydroxydocosanoic acid, α-hydroxytetraeicosanoic acid, α-hydroxyhexahexaic acid. Eicosanoic acid, α-hydroxyoctaicosanoic acid, α-hydroxytriacontanoic acid, β-hydroxymyristic acid, 10-hydroxydecanoic acid, 15-hydroxypentadecanoic acid, 16-hydroxyhexadecanoic acid, 12-hydroxystearic acid, ricinol Acid etc. are included.

  On the other hand, the aliphatic oxycarboxylic acid may be an aliphatic oxycarboxylic acid having 9 or less carbon atoms or 31 or more carbon atoms. Examples of aliphatic oxycarboxylic acids other than those described above include glycolic acid, lactic acid, hydroacrylic acid, α-oxybutyric acid, α-hydroxyisobutyric acid, δ-hydroxycaproic acid, α-hydroxytriacontanoic acid, α- Hydroxytetratriacontanoic acid, [alpha] -hydroxyhexatriacontanoic acid, [alpha] -hydroxyoctatriacontanoic acid, [alpha] -hydroxytetracontannic acid, glyceric acid, tartronic acid, malic acid, citric acid and the like are included.

  Examples of the aromatic oxycarboxylic acid include salicylic acid, m-oxybenzoic acid, p-oxybenzoic acid, gallic acid, mandelic acid, trovic acid and the like.

  Examples of the metal in the oxycarboxylic acid metal salt (D) include alkali metals such as lithium; alkaline earth metals such as magnesium and calcium.

  The metal oxycarboxylic acid salt (D) is preferably a metal salt of 12-hydroxystearic acid, particularly preferably 12-hydroxymagnesium stearate, or 12-hydroxycalcium stearate, 12-hydroxy, from the viewpoint of availability. Sodium stearate. In addition, when stearic acid is used, compared with the case where 12-hydroxy stearic acid metal salt is used, the fall of compatibility, the internal slip, and the crystallization fall by making into a nucleating agent are considered.

  The content of the oxycarboxylic acid metal salt (D) in the resin composition of the present invention is the total of the polyester resin (A), the inorganic filler (B), the white pigment (C), and the oxycarboxylic acid metal salt (D). When the content is 100% by mass, it is 0.1 to 2.0% by mass. The content of the oxycarboxylic acid metal salt (D) is preferably 0.1 to 1.5% by mass, and more preferably 0.1 to 1% by mass. When the content of the metal oxycarboxylic acid salt (D) is 0.1% by mass or more, the flowability of the reflective material obtained from the resin composition is likely to increase, and the strength of the reflective material is likely to increase. On the other hand, when the content of the oxycarboxylic acid metal salt (D) is 2.0% by mass or less, the amount of gas generated from the decomposition product of the oxycarboxylic acid metal salt during processing of the resin composition decreases, The appearance of the reflective material tends to be good.

1-5. Other In addition to the above-described polyester resin (A), inorganic filler (B), white pigment (C), and oxycarboxylic acid metal salt (D), the resin composition is a light stabilizer or an antioxidant as necessary. Further, a modified olefin polymer may be included.

  The light stabilizer mainly has an action of preventing deterioration of the polyester resin (A) due to light such as ultraviolet rays, and the light stabilizer can be, for example, a hindered amine light stabilizer.

  The hindered amine-based light stabilizer is not particularly limited as long as it can increase the light stability of the reflector, but after being heated at a temperature of 20 ° C./minute from a temperature of 25 ° C. to 340 ° C. in a nitrogen atmosphere. When the temperature is maintained at 340 ° C. for 10 minutes, the mass reduction rate is preferably 0 to 50% by mass, more preferably 0 to 40% by mass, and further preferably 0 to 30% by mass. .

  Examples of hindered amine light stabilizers include N, N′-bis-2,2,6,6-tetramethyl-4-piperidyl-1,3-benzenedicarboxamide, 1,2,3,4- Butanetetracarboxylic acid and 1,2,2,6,6-pentamethyl-4-piperidinol and 3,9-bis (2-hydroxy-1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro [5.5] Mixed esterified product with undecane, N, N ′, N ″, N ′ ″-tetrakis- (4,6-bis- (butyl- (N-methyl-2,2,6,6) -Tetramethylpiperidin-4-yl) amino) -triazin-2-yl) -4,7-diazadecane-1,10-diamine and poly [{6- (1,1,3,3-tetramethylbutyl) Amino-1,3,5-triazine-2 4- diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}] is included.

  When the resin composition of the present invention contains a hindered amine light stabilizer, the content of the hindered amine light stabilizer is as follows: polyester resin (A), inorganic filler (B), white pigment (C), and When the total of the oxycarboxylic acid metal salt (D) is 100% by mass, it is preferably 0.1 to 2% by mass, more preferably 0.1 to 1.5% by mass, More preferably, it is -0.5 mass%.

  Examples of antioxidants include hindered phenols, phosphorus, amines and sulfur antioxidants.

From the viewpoint of suppressing the decomposition reaction of the polyester resin (A) and suppressing discoloration of the resin composition under a high temperature atmosphere (especially, conditions exceeding 250 ° C. as in the reflow soldering process), the antioxidant is , Hindered phenols or phosphorus antioxidants are preferred. Examples of the hindered phenol antioxidant are represented by pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and the following general formula (1). Compounds are included. Examples of the phosphorus-based antioxidant include a compound having a P (OR) ₃ structure (R is an alkyl group, an alkylene group, an aryl group, an arylene group, or the like). From the above viewpoint, a compound represented by the following general formula (1) is more preferable.

  X in the general formula (1) represents an organic group. The organic group X is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cyclohexyl group, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms. Examples of the substituted or unsubstituted alkyl group having 1 to 20 carbon atoms include methyl group, ethyl group, n-propyl group, n-octyl group, n-tetradecyl group, and n-hexadecyl group. Examples of the substituted or unsubstituted aryl group having 6 to 20 carbon atoms include 2,4-di-t-butylphenyl group and 2,4-di-t-pentylphenyl group. Examples of the substituent that the alkyl group, cyclohexyl group and aryl group may have include an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, a hydroxy group, a methoxy group, and an oxadiazole. A group is included.

Examples of the compound represented by the general formula (1) include the following compounds.

  The content of the antioxidant is 10% by mass when the total of the polyester resin (A), inorganic filler (B), white pigment (C), and oxycarboxylic acid metal salt (D) is 100% by mass. Is preferably 5% by mass or less, more preferably 1% by mass or less.

  The resin composition may further contain a modified olefin polymer. When the resin composition contains a modified olefin polymer, it becomes difficult to break even if the reflector is bent, and the toughness is increased. The modified olefin polymer is a polymer obtained by modifying an olefin polymer with a compound having a specific functional group. Examples of the specific functional group contained in the modified olefin functional group include a functional group containing a hetero atom and an aromatic hydrocarbon group. It is considered that the toughness of the reflector is increased by the functional group contained in the modified olefin polymer interacting with the polyester resin (A).

  The hetero atom included in the functional group is preferably oxygen, and the functional group including the hetero atom preferably includes carbon, hydrogen, and oxygen. Specific examples of the functional group containing a hetero atom include an ester group, an ether group, a carboxylic acid group (including a carboxylic anhydride group), an aldehyde group, and a ketone group.

  The modified olefin polymer preferably includes 0.2 to 1.8% by mass of a structural unit having a functional group (hereinafter also referred to as “functional group structural unit”) with respect to 100% by mass of the modified olefin polymer. . The content of the functional group structural unit contained in the modified olefin polymer is more preferably 0.2 to 1.2% by mass. When there are too few functional group structural units, the interaction between the modified olefin polymer and the polyester resin (A) becomes weak, and the modified olefin polymer tends to aggregate.

  On the other hand, when there are too many functional group structural units, the interaction with the polyester resin (A) becomes too strong and the melt fluidity is lowered, and as a result, the moldability may be lowered. In addition, this excessive functional group may cause coloration due to modification by heat or light, and as a result, the reflectance of the reflective material may be lowered. In addition, if there are too many functional group structural units, unreacted substances tend to increase when the functional group structural units are introduced into the olefin polymer, and these unreacted substances accelerate problems (coloring, etc.) due to the aforementioned modification. There is also a case where

The content rate of the functional group structural unit which a modified olefin polymer contains is specified by well-known means, such as preparation ratio, < ¹³ > C-NMR measurement, and < ¹ > H-NMR measurement. NMR measurement can be performed, for example, by the method described in paragraphs 0063 to 0065 of WO2013 / 018360.

  On the other hand, as the skeleton part (olefin polymer) of the modified olefin polymer, a known olefin polymer such as an ethylene polymer, a propylene polymer, a butene polymer or a copolymer of these olefins may be used. it can. A particularly preferred olefin polymer is a copolymer of ethylene and an α-olefin having 3 or more carbon atoms.

  One preferred example of the olefin polymer is an ethylene / α-olefin copolymer. Hereinafter, although the case where an ethylene / α-olefin copolymer is used as the olefin polymer is described, the olefin polymer is not limited to the ethylene / α-olefin copolymer.

  The ethylene / α-olefin copolymer is composed of ethylene and other olefins such as propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, etc. It is a copolymer with an α-olefin. Specific examples of the ethylene / α-olefin copolymer include an ethylene / propylene copolymer, an ethylene / 1-butene copolymer, an ethylene / 1-hexene copolymer, an ethylene / 1-octene copolymer, 4-methyl-1-pentene copolymer and the like are included. Among these, an ethylene / propylene copolymer, an ethylene / 1-butene copolymer, an ethylene / 1-hexene copolymer, an ethylene / 1-octene copolymer, and the like are preferable.

  The structural unit derived from ethylene in the ethylene / α-olefin copolymer is 70 to 99.5 mol%, preferably 80 to 99 mol%, and the structural unit derived from α-olefin is 0.5 to 30 mol. %, Preferably 1 to 20 mol%.

  The ethylene / α-olefin copolymer has a melt flow rate (MFR) at 190 ° C. and a load of 2.16 kg according to ASTM D1238 of 0.01 to 20 g / 10 min, preferably 0.05 to 20 g / 10 min. It is preferable that

  The method for producing the ethylene / α-olefin copolymer is not particularly limited. For example, a transition metal catalyst such as titanium (Ti), vanadium (V), chromium (Cr), or zirconium (Zr) is used. Can be prepared by a known method. More specifically, by copolymerizing ethylene and one or more α-olefins having 3 to 10 carbon atoms in the presence of a Ziegler catalyst or a metallocene catalyst composed of a V compound and an organoaluminum compound. Can be manufactured. In particular, a production method using a metallocene catalyst is suitable.

  The modified olefin polymer is obtained by reacting the olefin polymer with the functional group-containing compound having the functional group described above. Preferred examples of the functional group-containing compound include an unsaturated carboxylic acid or its carboxylic acid. Derivatives are included. Specific examples of the functional group-containing compound include acrylic acid, methacrylic acid, α-ethylacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, endocis-bicyclo [2,2 , 1] Unsaturated carboxylic acids such as hept-5-ene-2,3-dicarboxylic acid (Nadic acid [trademark]), and derivatives thereof such as acid halides, amides, imides, acid anhydrides, esters, etc. . Among these, unsaturated dicarboxylic acid or its acid anhydride is preferable, and maleic acid, Nadic acid (trademark), or these acid anhydrides are more preferable.

  A particularly preferred example of the functional group-containing compound is maleic anhydride. Maleic anhydride has a relatively high reactivity with the olefin polymer, and itself has little major structural change due to polymerization or the like. For this reason, it is easy to obtain a modified olefin polymer having a stable quality.

  As an example of a method for obtaining a modified olefin polymer using an ethylene / α-olefin copolymer, there is a so-called graft modification method of the ethylene / α-olefin copolymer with a functional group-containing compound.

  The graft modification of the ethylene / α-olefin copolymer can be performed by, for example, the method described in paragraphs 0058 to 0062 of WO2013 / 018360.

The preferable density of the modified ethylene / α-olefin copolymer is 0.80 to 0.95 g / cm ³ , more preferably 0.85 to 0.90 g / cm ³ .

  Furthermore, the intrinsic viscosity [η] measured in a 135 ° C. decalin (decahydronaphthalene) solution of the modified ethylene / α-olefin copolymer is preferably 1.5 to 4.5 dl / g, more preferably 1 .6-3 dl / g. When [η] is within the above range, the bending strength and the melt fluidity of the reflector obtained from the resin composition can be compatible at a high level.

  When the resin composition of the present invention contains a modified olefin polymer, the preferred content of the modified olefin polymer is polyester resin (A), inorganic filler (B), white pigment (C), and metal oxocarboxylate. When the total amount of the salt (D) is 100% by mass, it is 0.3 to 1.5% by mass, more preferably 0.5 to 1.3% by mass, and still more preferably 0.5 to 1.% by mass. 1% by mass.

  When the content ratio of the modified olefin polymer is 1.5% by mass or less, the modified olefin polymer is uniformly dispersed and a resin composition having no uneven viscosity is obtained. Therefore, folding of the inorganic filler (B) is suppressed. Further, high toughness can be imparted without impairing the heat resistance of the reflecting material and the temporal stability of the reflectance. When the content of the modified olefin polymer is 0.3% by mass or more, the modified olefin polymer functions as a protective material (cushion material) for the inorganic filler (B), and the inorganic filler (B) is bent. Can be suppressed. Therefore, it becomes possible to make the reflective material exhibit toughness, heat resistance, and higher reflectance.

  In addition, the resin composition has other components, for example, a light stabilizer other than a hindered amine, a heat stabilizer, another polymer, a flame retardant, a fluorescent enhancement, and the like within a range not impairing the effects of the present invention. Various known components such as a whitening agent, a plasticizer, a thickener, an antistatic agent, a release agent, a pigment, and a crystal nucleating agent may be included.

  Examples of the light stabilizers other than the hindered amines include light stabilizers of benzotriazoles, triazines, benzophenones, and ogizanides.

  Examples of the heat-resistant stabilizer include lactone compounds, vitamin Es, hydroquinones, copper halides, and iodine compounds.

  Examples of other polymers include polyolefins, ethylene / α-olefin copolymers such as ethylene / propylene copolymers and ethylene / 1-butene copolymers, and propylene such as propylene / 1-butene copolymers. Α-olefin copolymer, polystyrene, polyamide, polycarbonate, polyacetal, polysulfone, polyphenylene oxide, fluororesin, silicone resin, and LCP (liquid crystal polymer) are included.

  It is preferable that the other components do not contain components or elements that become catalyst poisons. Examples of the components and elements that become the catalyst poison include sulfur and sulfur-containing compounds.

2. Production method of resin composition The resin composition of the present invention can be produced by a known method. Examples of the known methods include a method in which the above components are mixed in a Henschel mixer, a V blender, a ribbon blender or a tumbler blender, and after the mixing, a single screw extruder, a multi-screw extruder, a kneader or a banbury. A method of melt-kneading with a mixer and granulating or pulverizing after the melt-kneading is included.

  The melt kneading is preferably performed at a temperature 5 to 30 ° C. higher than the melting point of the polyester resin (A). The melt kneading temperature is preferably 255 ° C. or higher, more preferably 275 ° C. or higher, further preferably 295 ° C. or higher. The temperature of the melt kneading is preferably 360 ° C. or less, and more preferably 340 ° C. or less.

3. Reflective Material The reflective material of the present invention can be produced by molding the resin composition of the present invention. The resin composition described above has good moldability and a sufficiently long flow length. Therefore, a reflecting material having a desired shape can be obtained by molding.

  The said shaping | molding can be performed with the well-known shaping | molding method which manufactures a reflecting material from a resin composition. Examples of the known molding method include a known heat molding method. Examples of the known thermoforming methods include injection molding, insert molding including hoop molding, melt molding, extrusion molding, inflation molding, and blow molding.

  Thus, the manufactured reflector of this invention contains the said polyester resin (A), an inorganic filler (B), a white pigment (C), and an oxycarboxylic acid metal salt (D) in the above-mentioned ratio. To do.

The reflective material preferably has a reflectance of light having a wavelength of 450 nm of 90% or more, and more preferably 93% or more. The said reflectance should just be the value measured by the well-known method, for example, can be made into the value obtained by measuring the molded object whose thickness is 0.5 mm using Minolta Co., Ltd. CM3500d. The reflectance of the reflecting material can be adjusted by, for example, the amount of white pigment. Moreover, it is preferable that the reflectance of the light with a wavelength of 450 nm of a reflective material measured after irradiating with ultraviolet rays at 16 mW / cm ² for 500 hours is 87% or more.

  The reflective material can be a casing or housing having a surface that reflects light. At this time, the shape of the surface that reflects the light may be any of a planar shape, a curved surface shape, and a spherical shape. For example, the shape of the reflector can be a box shape, a funnel shape, a bowl shape, a parabolic shape, a columnar shape, a conical shape, and a honeycomb shape.

  The reflective material can be used for an element having a light source, for example. Examples of elements include organic EL elements and light emitting diode (LED) elements. The LED is preferably an LED compatible with surface mounting. In these elements, the reflector reflects the light emitted from the light source.

  A light emitting diode (LED) element having a reflective material is, for example, a housing portion formed on a substrate having a space for mounting an LED, the LED mounted in the space, and a seal for sealing the LED. And a stop member. Such an LED element can be manufactured by a known method. For example, 1) a step of manufacturing a housing part by molding a reflective material on a substrate, 2) a step of placing an LED inside the housing part, and electrically connecting the LED and the substrate, and 3) the above step A method including a step of sealing the LED with a sealant.

  In such an LED element, the reflective material is exposed to high-temperature heat in the above 2) and 3) processes, or receives light including visible light and ultraviolet light generated from the LED during use and heat. Or However, as described above, the oxycarboxylic acid metal salt (D) functions as a crystal nucleating agent or functions as an antioxidant, so that it is difficult for the reflective material to be discolored and a high reflectance is maintained. .

  Such a reflective material can be used for various applications. Examples of the applications include various electric / electronic components, indoor lighting, outdoor lighting, and automobile lighting.

  In the following, the present invention will be described with reference to examples. By way of example, the scope of the invention is not construed as limiting.

1. Preparation of material <Polyester resin (A)>
106.2 parts by mass of dimethyl terephthalate and 94.6 parts by mass of 1,4-cyclohexanedimethanol (cis / trans ratio: 30/70) (manufactured by Tokyo Chemical Industry Co., Ltd.) were mixed. To the mixture, 0.0037 parts by mass of tetrabutyl titanate was added, and the temperature was raised from 150 ° C. to 300 ° C. over 3 hours and 30 minutes to cause a transesterification reaction.

  At the end of the transesterification reaction, 0.066 parts by mass of magnesium acetate tetrahydrate dissolved in 1,4-cyclohexanedimethanol was added, followed by polycondensation reaction by introducing 0.1027 parts by mass of tetrabutyl titanate. The polycondensation reaction was carried out by gradually reducing the pressure from normal pressure to 1 Torr over 85 minutes and simultaneously raising the temperature to a predetermined polymerization temperature of 300 ° C. Stirring was continued while maintaining the temperature and pressure, and the reaction was terminated when a predetermined stirring torque was reached. Thereafter, the obtained polymer was taken out and subjected to solid phase polymerization at 260 ° C. and 1 Torr or less for 3 hours to obtain a polyester resin. The melting point of the obtained polyester resin was 290 ° C.

(Melting point)
The melting point of the polyester resin (A) was measured using DSC7 manufactured by PerkinElmer. First, the polyester resin (A) was once heated to 330 ° C. and held for 5 minutes. Then, after the temperature was lowered to 23 ° C. at a rate of 10 ° C./min, the temperature was raised at 10 ° C./min. The endothermic peak based on melting at this time was defined as the melting point.

<Inorganic filler (B)>
Glass fiber as the inorganic filler (B): ECS03T-790DE manufactured by Nippon Electric Glass Co., Ltd., silane compound treated product (average fiber length (l): 3 mm, average fiber diameter (d) of fiber cross section (d) 6 μm true circle, aspect ratio ( (Average fiber length / average fiber diameter) 500) was used.

<White pigment (C)>
Titanium oxide (powder, average particle size: 0.21 μm) was used as the white pigment (C).
The average particle size of titanium oxide was determined as follows. First, based on a transmission electron micrograph, an amount of particle (%) in each particle size section of primary particles was plotted using an image diffractometer (Luzex IIIU) to obtain a distribution curve. A cumulative distribution curve was obtained from the obtained distribution curve, and the value at a cumulative degree of 50% in this cumulative distribution curve was taken as the average particle diameter.

<Oxycarboxylic acid metal salt (D)>
The following two compounds were used as the oxycarboxylic acid metal salt (D).
-Sodium 12-hydroxystearate-Calcium 12-hydroxystearate

<Others>
As other components, the following components were used as needed.
・ Nucleating agent (High filler # 5000PJ (Matsumura Sangyo Co., Ltd.))
・ Sodium montanate ・ Antioxidant 1 (ADK STAB PEP-36 (manufactured by ADEKA))
Antioxidant 2 (Irganox 1010 (manufactured by BASF))

2. Preparation of polyester resin composition for reflector [Example 1]
53.63 parts by mass of polyester resin (A), 10 parts by mass of glass fiber as inorganic filler (B), 35 parts by mass of titanium oxide as white pigment (C), and 12-hydroxystearic acid as metal salt of oxycarboxylic acid (D) 0.5 parts by weight of sodium, 0.08 parts by weight of antioxidant 1, 0.63 parts by weight of nucleating agent, and 0.16 parts by weight of antioxidant 2 were prepared and mixed using a tumbler blender. . The obtained mixture was melt-kneaded at a cylinder temperature of 300 ° C. with a twin-screw extruder (TEX30α manufactured by Nippon Steel Works). Thereafter, it was extruded into a strand shape. The extrudate was cooled in a water tank, and then the strands were drawn with a pelletizer and cut to obtain a polyester resin composition for a reflector in the form of pellets. The compound property of the obtained polyester resin composition for reflectors was good.

[Example 2 and Comparative Examples 1 and 2]
Except having changed into the composition shown in Table 1, it carried out similarly to Example 1, and obtained the polyester resin composition for pellet-like reflectors of Example 2 and Comparative Examples 1 and 2. FIG.

  The reflectivity and fluidity of the reflective material obtained from the polyester resin composition for reflective material obtained in each example and each comparative example, and the strength of the reflective material were measured or evaluated by the following methods.

<Reflectance>
(Initial reflectance)
The obtained pellet-shaped polyester resin composition for reflectors was injection molded under the following molding conditions using the following molding machine. Thus, a test piece having a length of 30 mm, a width of 30 mm, and a thickness of 0.5 mm was produced. About the obtained test piece, the reflectance of wavelength 360nm -740nm was calculated | required using Minolta CM3500d. And the reflectance of wavelength 450nm was made into the representative value of the initial reflectance.
Molding machine: SE50DU, manufactured by Sumitomo Heavy Industries, Ltd.
Cylinder temperature: melting point (Tm) of polyester resin (A) + 10 ° C.
Mold temperature: 150 ° C

(Reflectance after heating test)
The sample piece whose initial reflectance was measured was left in an oven at 150 ° C. for 500 hours. Thereafter, the reflectance of the test piece was measured by the same method as the initial reflectance, and the reflectance at a wavelength of 450 nm was used as a representative value of the reflectance after heating.

<Fluidity>
The obtained polyester resin composition for a reflector is injection-molded under the following conditions using a bar flow mold having a width of 10 mm and a thickness of 0.5 mm, and the flow length (mm) of the resin composition in the mold is determined. It was measured.
Injection molding machine: TUPARL TR40S3A manufactured by Sodick
Injection set pressure: 2000 kg / cm ²
Cylinder setting temperature: melting point (Tm) of polyester resin (A) + 10 ° C.
Mold temperature: 30 ℃

<Bending strength (toughness, strength, elastic modulus, and deflection amount)>
The polyester resin composition for reflectors was molded under the following molding conditions using the following injection molding machine to prepare a test piece having a length of 64 mm, a width of 6 mm, and a thickness of 0.8 mm. The test piece was left for 24 hours under a nitrogen atmosphere at a temperature of 23 ° C. Next, a bending test is performed in an atmosphere of a temperature of 23 ° C. and a relative humidity of 50%: AB5 manufactured by INTESCO, span 26 mm, bending speed 5 mm / min, and strength (toughness, strength, elastic modulus, and deflection amount) Was measured respectively.
Injection molding machine: TUPARL TR40S3A manufactured by Sodick
Molding machine cylinder temperature: melting point (Tm) of polyester resin (A) + 10 ° C.
Mold temperature: 150 ° C

  The evaluation results of Examples 1 and 2 and Comparative Examples 1 and 2 are shown in Table 1.

  As shown in Table 1 above, obtained from a polyester resin composition for a reflector containing a polyester resin (A), an inorganic filler (B), a white pigment C, and an oxycarboxylic acid metal salt (D) in a predetermined ratio. The resulting reflective material had high reflectivity even when exposed to high temperatures, and had sufficiently high toughness, strength, and elastic modulus. Further, the amount of deflection was sufficient. Furthermore, the fluidity at the time of shaping | molding of the polyester resin composition for reflectors was also favorable (Example 1 and 2).

  On the other hand, in the comparative example 1 containing a carboxylic acid metal salt instead of an oxycarboxylic acid metal salt (D), the fluidity at the time of shaping | molding of the polyester resin composition for reflectors was not enough. Carboxylic acid metal salts are relatively less compatible with polyester resins and the like than oxycarboxylic acid metal salts. Therefore, it is guessed that it was difficult to improve the fluidity of the resin composition. Moreover, in the said comparative example, the reflectance after a heating was low. On the other hand, in the comparative example 2 which does not contain either an oxycarboxylic acid metal salt or a carboxylic acid metal salt, the strength of the obtained reflecting material was low.

  The polyester resin composition for a reflector of the present invention has good fluidity during molding. Furthermore, even if the reflective material obtained from the said polyester resin composition for reflective materials is exposed to high temperature, a reflectance does not fall easily. Therefore, it is very useful as a reflector for various lighting devices.

Claims (8)

30-80% by mass of a polyester resin (A) having a melting point or glass transition temperature of 250 ° C. or higher,
1-50% by mass of inorganic filler (B),
White pigment (C) 5-50 mass%,
0.1 to 2.0% by mass of oxycarboxylic acid metal salt (D) (however, the polyester resin (A), the inorganic filler (B), the white pigment (C), and the oxycarboxylic acid metal salt) The total of (D) is 100% by mass),
A polyester resin composition for reflectors, comprising:   The polyester resin composition for a reflector according to claim 1, wherein the oxycarboxylic acid metal salt (D) is a 12-hydroxystearic acid metal salt. The polyester resin (A) includes a dicarboxylic acid component unit (a1) derived from a dicarboxylic acid and a dialcohol component unit (a2) derived from a dialcohol,
The dicarboxylic acid component unit (a1) includes 30 to 100 mol% of component units derived from terephthalic acid, and 0 to 70 mol% of component units derived from an aromatic dicarboxylic acid other than terephthalic acid,
The dialcohol component unit (a2) includes a component unit derived from an alicyclic dialcohol having an alicyclic hydrocarbon skeleton having 4 to 20 carbon atoms and / or a component unit derived from an aliphatic dialcohol.
The polyester resin composition for reflectors according to claim 1 or 2. The dialcohol component unit (a2) includes a component unit derived from an alicyclic dialcohol having a cyclohexane skeleton,
The polyester resin composition for reflectors according to claim 3. The dialcohol component unit (a2) includes 30 to 100 mol% of component units derived from 1,4-cyclohexanedimethanol and 0 to 70 mol% of component units derived from the aliphatic dialcohol.
The polyester resin composition for reflectors according to claim 3 or 4. The white pigment (C) is titanium oxide.
The polyester resin composition for reflectors according to any one of claims 1 to 5.   A reflective material comprising a molded article of the polyester resin composition for a reflective material according to claim 1. The reflective material according to claim 7, which is a reflective material for a light emitting diode element.