JP2019127545A - Polyester resin composition for reflection material and reflection material - Google Patents

Abstract

To provide a polyester resin composition having excellent fluidity in molding and giving a reflection material that has high mechanical strength and less likely causes reduction in the reflectance when exposed to a high temperature for a long period of time or less likely cracks when irradiated with light for a given time or longer.SOLUTION: The polyester resin composition comprises a polyester resin (A) having a melting point (Tm) or a glass transition temperature (Tg) of 270°C or higher by 30 pts.mass or more and 80 pts.mass or less, surface-treated calcium carbonate (B) having an average particle diameter of 0.05 μm or more and 1 μm or less by 3 pts.mass or more and 15 pts.mass or less, surface-treated titanium oxide (C) by 10 pts.mass or more and 50 pts.mass or less, and an inorganic filler (D) by 5 pts.mass or more and 30 pts.mass or less, where the total of (A) to (D) is set to 100 pts.mass. A mass ratio (B):(C) is 10:90 to 60:40.SELECTED DRAWING: None

Description

  The present invention relates to a polyester resin composition for a reflector and a reflector.

  Light sources such as light emitting diodes (LEDs) and organic ELs are widely used for lighting and backlighting of displays, taking advantage of their characteristics (for example, low power and long life). Reflectors are used in various aspects to efficiently utilize the light from these light sources.

  For example, the LED element includes a housing part (reflecting material) provided 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. . Such an LED element, for example, 1) forming a housing portion on a substrate, 2) disposing the LED inside the housing portion, electrically connecting the LED and the substrate, and 3) LED Are manufactured through the process of sealing with a sealant.

  In the sealing step 3), the sealing agent is heated to 100 to 200 ° C. to be thermally cured. Therefore, the housing part is exposed to a high temperature of 100 to 200 ° C. Furthermore, in the 2) mounting process of the LED, a reflow soldering process is performed to mount the LED on the substrate, but also in this case, the housing portion is exposed to a temperature of 250 ° C. or more. Reflectors such as housing parts are required to maintain the reflectance even after such 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.

  To meet these requirements, Patent Document 1 discloses, as a material of a reflector, polycyclohexylene dimethylene terephthalate, an inorganic filler such as glass fiber, a white pigment such as titanium oxide, a silicone compound, and an organic acid. And a nucleating agent such as a metal salt of According to Patent Document 1, by combining the silicone compound and the nucleation agent, the composition can improve the molding processability and can reduce the decrease in reflectance at high temperature.

Japanese Patent Application Publication No. 2016-504459

  However, in the resin composition shown in Patent Document 1, the fluidity at the time of molding is not sufficient, and the obtained molded article does not have sufficient mechanical strength. Moreover, the molded object obtained from the said resin composition produced a color change when exposed to high temperature for a long time, and the reflectance fell, and it was easy to produce a crack in a short time when light-irradiated more than fixed time. .

  As described above, the flowability during molding is excellent, the mechanical strength is high, and the reflectance decreases when exposed to high temperatures for a long time, and cracks occur in a short time when irradiated with light for a predetermined time or more. There is a demand for a resin composition capable of providing a non-reflective material (hereinafter, also simply referred to as "less likely to cause cracking").

  The present invention has been made in view of the above circumstances, has excellent fluidity at the time of molding, has high mechanical strength, and lowers the reflectance when exposed to high temperature for a long time or is irradiated with light for a certain time or more. It is an object of the present invention to provide a polyester resin composition for a reflector that can provide a reflector that is less likely to cause cracks when applied.

[1] 30 to 80 parts by mass of a polyester resin (A) having a melting point (Tm) or glass transition temperature (Tg) measured by a differential scanning calorimeter (DSC) of 270 ° C. or more, calcium carbonate, 3 to 15 parts by mass of a surface-treated calcium carbonate (B) having an average particle size of 0.05 μm or more and 1 μm or less containing a condensed phosphoric acid and an organic silicon compound or a cured product thereof covering at least a part of the surface; 10 parts by weight or more and 50 parts by weight or less of a surface-treated titanium oxide (C) containing titanium oxide and an organosilicon compound covering at least a part of the surface or a cured product thereof, and 5 parts by weight or more of an inorganic filler (D) And 30 parts by mass or less (provided that the total of (A), (B), (C) and (D) is 100 parts by mass), the surface-treated calcium carbonate (B) and Serial surface-treated titanium oxide (C) and containing a weight ratio of (B) :( C) is from 10: 90-60: 40, reflective material for the polyester resin composition.
[2] The phosphorus content in the surface-treated calcium carbonate (B) is 0.2 parts by mass or more and 2 parts by mass or less with respect to 100 parts by mass of the surface-treated calcium carbonate (B). Polyester resin composition for reflectors.
[3] The content of the organosilicon compound or the cured product thereof in the surface-treated calcium carbonate (B) is 0.1 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the calcium carbonate, [1] Or the polyester resin composition for reflectors as described in [2].
[4] The polyester resin composition for a reflector according to any one of [1] to [3], wherein the organosilicon compound or the cured product thereof in the surface-treated calcium carbonate (B) is an epoxy-modified silicone.
[5] The surface-treated titanium oxide (C) may further contain silicon oxide that covers at least a part of the surface of the titanium oxide, and includes the total of the organosilicon compound or a cured product thereof and the silicon oxide. The polyester resin composition for reflectors in any one of [1]-[4] whose quantity is 0.01 mass part or more and 2 mass parts or less with respect to 100 mass parts of said titanium oxides.
[6] The polyester resin (A) includes a component unit (a1) derived from a dicarboxylic acid and a component unit (a2) derived from a dialcohol, and the component unit (a1) derived from the dicarboxylic acid is: 30 mol% or more and 100 mol% or less of component units derived from terephthalic acid, and components derived from aromatic dicarboxylic acids other than terephthalic acid, with respect to 100 mol% in total of the component units (a1) derived from the dicarboxylic acid Component unit (a2) containing 0 mol% or more and 70 mol% or less and the component unit (a2) derived from the dialcohol is a component unit derived from an alicyclic dialcohol having 4 to 20 carbon atoms and an aliphatic dialcohol The polyester resin composition for reflectors in any one of [1]-[5] which contains at least one of the component unit originating in the.
[7] The polyester resin composition for a reflector according to [6], wherein the component unit (a2) derived from the dialcohol includes a component unit derived from an alicyclic dialcohol having a cyclohexane skeleton.
[8] The component unit (a2) derived from the dialcohol has 30 component units derived from 1,4-cyclohexanedimethanol with respect to 100 mol% in total of the component unit (a2) derived from the dialcohol. The polyester resin composition for a reflector according to [6] or [7], comprising from mol% to 100 mol% and from 0 mol% to 70 mol% of a component unit derived from the aliphatic dialcohol.
[9] The polyester resin composition for a reflector according to any one of [1] to [8], wherein the inorganic filler (D) is glass fiber.
[10] A reflective material comprising the polyester resin composition for reflective material according to any one of [1] to [9].
[11] The reflector according to [10], which is a reflector for a light emitting diode element.

  According to the present invention, the fluidity at the time of molding is excellent, the mechanical strength is high, and the reflectance decreases when exposed to high temperature for a long time, and the crack hardly occurs when irradiated with light for a predetermined time or more. A polyester resin composition for a reflector that can be provided with a reflector can be provided.

  As a result of intensive studies, the present inventors have found that calcium carbonate surface-treated with condensed phosphoric acid and an organosilicon compound (hereinafter also referred to as “surface-treated calcium carbonate (B)”) and titanium oxide surface-treated with an organosilicon compound. It is found that a polyester resin composition having excellent fluidity at the time of molding and processing and high mechanical strength can be obtained by combining (hereinafter also referred to as “surface-treated titanium oxide (C)”) in a predetermined ratio. It was.

  The reason for this is not clear, but is presumed as follows. Since both the specific surface-treated calcium carbonate (B) and the specific surface-treated titanium oxide (C) have improved particle surface slipperiness, they are easily diffused during molding and easily dispersed well. As a result, it is considered that the fluidity at the time of molding processing is likely to be increased, and (as a result of good dispersion) high mechanical strength is likely to be obtained.

  In addition, the inventors of the present invention combine the surface-treated calcium carbonate (B) and the surface-treated titanium oxide (C)) at a predetermined ratio to reduce the reflectance after storage at high temperatures of the resulting polyester resin composition. It has been found that when irradiated with light for a certain period of time or less, cracks are less likely to occur.

  The reason for this is not clear, but is presumed as follows. Since the surfaces of calcium carbonate and titanium oxide (particularly calcium carbonate) have activity, if they are exposed on the surface, the resin is likely to be deteriorated (decomposed) by heat or light in the vicinity of the exposed surface. In contrast, in the specific surface-treated calcium carbonate (B) and the specific surface-treated titanium oxide (C), since at least a part of the surface of calcium carbonate or titanium oxide is coated with a specific compound, It is inferred that the surface of the calcium carbonate or titanium oxide (having the activity) and the resin are unlikely to be in direct contact with each other, and deterioration (decomposition) of the resin due to heat or light can be suppressed. The present invention has been made based on such findings.

1. Polyester resin composition for reflectors The polyester resin composition for reflectors of the present invention comprises a polyester resin (A), surface-treated calcium carbonate (B), surface-treated titanium oxide (C), and an inorganic filler (D) Including.

1-1. Polyester resin (A)
The polyester resin (A) contains a component unit (a1) derived from a dicarboxylic acid and a component unit (a2) derived from a dialcohol.

  Component unit (a1) derived from dicarboxylic acid is 30 mol% or more and 100 mol% or less of component units derived from terephthalic acid, and 0 mol% or more and 70 moles or more of component units derived from aromatic dicarboxylic acid other than terephthalic acid It is preferable to contain% or less. The ratio of the component unit derived from terephthalic acid contained in the component unit (a1) derived from the dicarboxylic acid is more preferably 40 mol% or more and 100 mol% or less, still more preferably 60 mol% or more and 100 mol% or less It is possible. When the content of the component unit derived from terephthalic acid is high, the heat resistance of the polyester resin composition is further enhanced. The ratio of the component unit derived from the aromatic dicarboxylic acid other than terephthalic acid contained in the component unit (a1) derived from the dicarboxylic acid is more preferably 0 mol% or more and 60 mol% or less, and still more preferably 0 mol%. It may be 40 mol% or less. However, the total amount of component units (a1) derived from dicarboxylic acid is 100 mol%.

  Component unit (a1-1) derived from terephthalic acid may be a component unit derived from terephthalic acid or terephthalic acid ester. The terephthalic acid ester is preferably an alkyl ester having 1 to 4 carbon atoms of terephthalic acid, and examples thereof include dimethyl terephthalate.

  Examples of component units (a1-2) derived from aromatic dicarboxylic acids other than terephthalic acid include component units derived from isophthalic acid, 2-methylterephthalic acid, naphthalene dicarboxylic acid and combinations thereof, and aromatics thereof Component units derived from esters of dicarboxylic acids (preferably, alkyl esters having 1 to 4 carbon atoms of aromatic dicarboxylic acids) are included.

  The component unit (a1) derived from a dicarboxylic acid is a component unit derived from a polyvalent carboxylic acid having three or more carboxylic acid groups in a molecule or a molecule in a small amount together with the above component units May further be included. The ratio of the component unit derived from the aliphatic dicarboxylic acid contained in the component unit (a1) derived from the dicarboxylic acid and the component unit derived from the polyvalent carboxylic acid may be, for example, 10 mol% or less in total.

  The number of carbon atoms of the aliphatic dicarboxylic acid is not particularly limited, but is preferably 4 or more and 20 or less, and more preferably 6 or more and 12 or less. Examples of the aliphatic dicarboxylic acid include adipic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, undecanedicarboxylic acid and dodecanedicarboxylic acid. Among them, adipic acid is preferred. Examples of polyvalent carboxylic acids include tribasic acids including trimellitic acid and pyromellitic acid, and polybasic acids.

  The component unit (a2) derived from the dialcohol preferably includes a component unit derived from an alicyclic dialcohol having 4 to 20 carbon atoms and / or a component unit derived from an aliphatic dialcohol.

  The component unit (a2-1) derived from the alicyclic dialcohol can increase the heat resistance of the polyester resin composition and reduce water absorption. Examples of alicyclic dialcohols include dialcohols having an alicyclic hydrocarbon skeleton having 4 to 20 carbon atoms, such as 1,3-cyclopentanediol, 1,3-cyclopentadimethanol, 1,4 -Cyclohexanediol, 1,4-cyclohexanedimethanol, 1,4-cycloheptanediol and 1,4-cycloheptanedimethanol. Among these, from the standpoint that the heat resistance of the polyester resin composition is further increased, the water absorption is further reduced, and the availability is easy, a compound having a cyclohexane skeleton is preferable, and 1,4-cyclohexanedimethanol is more preferable. .

  The alicyclic dialcohol has isomers such as cis / trans structure, but from the viewpoint of further enhancing the heat resistance of the polyester resin composition, the polyester resin (A) is an alicyclic dialcohol having a trans structure. It is preferable to contain more component units derived from Therefore, the cis / trans ratio of the component unit derived from the alicyclic dialcohol is preferably 50/50 to 0/100, and more preferably 40/60 to 0/100.

  The component unit (a2-2) derived from an aliphatic dialcohol further enhances the melt flowability of the polyester resin composition. Examples of aliphatic dialcohols include ethylene glycol, trimethylene glycol, propylene glycol, tetramethylene glycol, neopentyl glycol, hexamethylene glycol and dodecamethylene glycol.

  The component unit (a2) derived from dialcohol includes only one of the component unit (a2-1) derived from the alicyclic dialcohol and the component unit (a2-2) derived from the aliphatic dialcohol. May be included, or both may be included. Component unit (a2) derived from a dialcohol is a component unit derived from an alicyclic dialcohol (preferably a component unit derived from a dialcohol having a cyclohexane skeleton, more preferably from 1,4-cyclohexanedimethanol It is preferable that 30 mol% or more and 100 mol% or less of the component unit) and 0 mol% or more and 70 mol% or less of the component unit derived from the aliphatic dialcohol. Component unit derived from alicyclic dialcohol contained in component unit (a2) derived from dialcohol (preferably, component unit derived from dialcohol having a cyclohexane skeleton, more preferably from 1,4-cyclohexanedimethanol The ratio of the component unit is more preferably 50 mol% or more and 100 mol% or less, and further preferably 60 mol% or more and 100 mol% or less. The proportion of component units derived from aliphatic dialcohols contained in component units (a2) derived from dialcohols is more preferably 0 mol% or more and 50 mol% or less, still more preferably 0 mol% or more and 40 mol% It is as follows. However, the total amount of the component units (a2) derived from dialcohol is 100 mol%.

  The component unit (a2) derived from a dialcohol may further contain a small amount of a component unit derived from an aromatic diol together with the component unit. Examples of aromatic dialcohols include bisphenol, hydroquinone and 2,2-bis (4-β-hydroxyethoxyphenyl) propane. The ratio of the component unit derived from the aromatic dialcohol contained in the component unit (a2) derived from the dialcohol may be, for example, 10 mol% or less.

  The melting point (Tm) or glass transition temperature (Tg) of the polyester resin (A) measured with a differential scanning calorimeter (DSC) is 270 ° C. or higher. When the melting point or glass transition temperature is 270 ° C. or higher, for example, even if exposed to high temperatures in a reflow soldering process, discoloration or deformation of the molded product (reflecting material) of the polyester resin composition due to heat can be suppressed. The melting point (Tm) or glass transition temperature (Tg) of the polyester resin (A) is preferably 350 ° C. or less. When the melting point or glass transition temperature is 350 ° C. or lower, it is easy to suppress the decomposition of the polyester resin (A) during melt molding. The melting point (Tm) or glass transition temperature (Tg) of the polyester resin (A) measured by differential scanning calorimetry (DSC) is more preferably 280 ° C. or more and 335 ° C. or less.

  The melting point of the polyester resin (A) can be measured by 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 polyester resin (A) is sealed is set in this apparatus, heated to 320 ° C. at a heating rate of 10 ° C./min under a nitrogen atmosphere, and held at that temperature for 5 minutes, The temperature is decreased to 30 ° C. by measuring the temperature decrease at 10 ° C./min. The temperature at the top of the endothermic peak at the time of temperature rise is defined as the “melting point”.

  The intrinsic viscosity [η] of the polyester resin (A) is preferably 0.3 dl / g or more and 1.2 dl / g or less. When the intrinsic viscosity is in the above range, the flowability at the time of molding of the polyester resin composition is good, and the mechanical strength is also excellent. The intrinsic viscosity of the polyester resin (A) can be adjusted, for example, by the degree of progress of the polycondensation reaction (polymerization temperature, polymerization time), addition of a molecular weight modifier (monofunctional carboxylic acid, monofunctional alcohol, etc.) .

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

In the above equation, each algebra or variable represents
[Η]: Intrinsic viscosity (dl / g)
ηSP: specific viscosity C: sample concentration (g / dl)
k: Constant (Slope determined by measuring the specific viscosity of samples (three or more points different in solution concentration), plotting the solution concentration on the abscissa and ηSP / C on the ordinate)

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

In the above formula, each variable represents the following.
t: Seconds of flow of sample solution (seconds)
t0: Second drop of solvent (seconds)

  The polyester resin (A) may be produced by a known method, or a commercially available product may be purchased. The polyester resin (A) may be produced, for example, by reacting a dicarboxylic acid component and a dialcohol component in the presence of a molecular weight regulator. Thereby, the intrinsic viscosity [η] of the polyester resin (A) may be adjusted to the above range.

  Examples of molecular weight modifiers 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. In addition, the aromatic monocarboxylic acid and the alicyclic monocarboxylic acid may have a substituent in the cyclic structure portion. Examples of 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 Be 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 mol or more and 0.07 mol or less, preferably 0 mol or more and 0.05 mol or less with respect to 1 mol of the total amount of the dicarboxylic acid component when the dicarboxylic acid component and the dialcohol component are reacted. It can be less than the mole.

  The content of the polyester resin (A) in the polyester resin composition of the present invention is the total of the polyester resin (A), surface-treated calcium carbonate (B), surface-treated titanium oxide (C), and inorganic filler (D) being 100. It is preferable that it is 30 to 80 mass parts when setting it as a mass part. When the content of the polyester resin (A) is 30 parts by mass or more, it is easy to obtain a polyester resin composition for a reflector excellent in heat resistance that can withstand a reflow soldering process without impairing moldability. The content of the polyester resin (A) is 40 masses when the total of the polyester resin (A), surface-treated calcium carbonate (B), surface-treated titanium oxide (C), and inorganic filler (D) is 100 parts by mass. More preferably, it is more than 70 parts by mass and more preferably not less than 50 parts by mass and not more than 60 parts by mass.

1-2. Surface treatment calcium carbonate (B)
The surface-treated calcium carbonate (B) may have a function to make the polyester resin composition white and to make it difficult to cause a decrease in reflectance or a crack due to heat or light.

  The surface-treated calcium carbonate (B) includes calcium carbonate and condensed phosphoric acid and an organosilicon compound or a cured product thereof covering at least a part of the surface. Such surface-treated calcium carbonate (B) can be obtained by surface-treating calcium carbonate with condensed phosphoric acid and an organosilicon compound.

(Calcium carbonate)
Calcium carbonate is preferably a synthetic calcium carbonate obtained by reacting calcium hydroxide with carbon dioxide gas from the viewpoint of easily adjusting the particle shape, particle diameter and the like. Calcium hydroxide can be obtained, for example, by reacting calcium oxide with water, and calcium oxide can be obtained, for example, by mixing limestone ore with coke or the like and calcining. In this case, since carbon dioxide gas is generated during firing, calcium carbonate can be produced by blowing this carbon dioxide gas into an aqueous suspension of calcium hydroxide and reacting the carbon dioxide gas with calcium hydroxide.

  The crystal structure of calcium carbonate is not particularly limited, but is preferably a calcite crystal (trigonal crystal) from the viewpoint of high stability and easy availability.

  The particle shape of calcium carbonate is not particularly limited, but is preferably substantially cubic from the viewpoint of improving the flowability at the time of molding.

  The average particle size of calcium carbonate is preferably 0.05 μm or more and 1 μm or less. When the average particle diameter of calcium carbonate is in the above range, the dispersibility is good, and the surface smoothness of the molded product is not easily impaired. The average particle size of calcium carbonate is more preferably 0.08 μm or more and 0.5 μm or less, and further preferably 0.1 μm or more and 0.3 μm or less.

  The average particle diameter of calcium carbonate can be measured by image analysis using an electron micrograph. Specifically, any 100 calcium carbonates are observed with an electron micrograph. Based on the obtained image, the amount of particles (mass%) in each particle diameter section of primary particles is plotted using an image diffractometer (Lusex IIIU) to obtain a distribution curve. A cumulative distribution curve is obtained from the obtained distribution curve, and the value when the cumulative degree in the cumulative distribution curve is 50% by mass is defined as an average particle diameter.

(Surface coating with condensed phosphoric acid)
The condensed phosphoric acid covers at least a part of the surface of calcium carbonate. That is, the coating covering at least a part of the surface of calcium carbonate contains condensed phosphoric acid.

The condensed phosphoric acid is a dehydration condensate of orthophosphoric acid (H ₃ PO ₄ ). Examples of the condensed phosphoric acid include metaphosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, tetrapolyphosphoric acid, trimetaphosphoric acid, tetrametaphosphoric acid, hexametaphosphoric acid, and alkali metal salts thereof. The condensed phosphoric acid contained in the coating may be one type or two or more types.

  The amount coated with condensed phosphoric acid (phosphorus content in surface treated calcium carbonate (B)) is preferably 0.2 parts by mass or more and 2 parts by mass or less with respect to 100 parts by mass of surface treated calcium carbonate (B). If the phosphorus content in the surface-treated calcium carbonate (B) is 0.2 parts by mass or more, the surface of the calcium carbonate that has not been surface-treated is small, and this causes the resin to deteriorate and become colored. Can be suppressed. Thereby, it is easy to suppress a decrease in reflectance after heating. In addition, when the phosphorus content in the surface-treated calcium carbonate (B) is 2 parts by mass or less, it is easy to suppress the coloring of the resin due to the reaction of the released condensed phosphoric acid with the resin, and the decrease in reflectance after heating Easy to suppress. The phosphorus content in the surface treated calcium carbonate (B) is more preferably 0.4 parts by mass or more and 1.8 parts by mass or less, and further preferably 0.6 parts by mass or more and 1.6 parts by mass or less. .

  The phosphorus content in the surface-treated calcium carbonate (B) may be calculated from the content mass ratio of phosphorus atoms in condensed phosphoric acid and the preparation amount thereof, or may be measured by ICP emission spectrometry. The polyester resin composition may be measured by performing X-ray fluorescence (XRF) analysis.

(Surface coating with organosilicon compound)
The organosilicon compound or its cured product covers at least a part of the surface of calcium carbonate. That is, the coating covering at least a part of the surface of calcium carbonate contains an organosilicon compound or a cured product thereof.

  Examples of the organosilicon compound in the “organosilicon compound or cured product thereof” include straight silicone oil (eg, dimethyl silicone oil, methylphenyl silicone oil), alkoxy silicone oil (eg, methoxy silicone, ethoxy silicone), organic modified silicone oil, And silane coupling agents such as vinyltriethoxysilane, 2-aminopropyltriethoxysilane, and 2-glycidoxypropyltriethoxysilane. Among them, organic modified silicone oil is preferable from the viewpoint of easily forming a coating relatively stably on the surface of calcium carbonate.

  Examples of organically modified silicone oil include epoxy modified silicone oil, amino modified silicone oil, amine modified silicone oil, mercapto modified silicone oil, carboxyl modified silicone oil, polyether modified silicone oil, fluoroalkyl modified silicone oil, long chain alkyl modified Silicone oil, phenyl modified silicone oil, higher fatty acid ester modified silicone oil, higher fatty acid amide modified silicone oil, acrylic modified silicone oil, methacrylic modified silicone oil, carboxylic anhydride modified silicone oil, carbinol modified silicone oil, diol modified silicone oil Etc. Among these, reactive silicone oil is preferable, and epoxy-modified silicone oil is more preferable from the viewpoint of easily performing a polymerization reaction on the surface of calcium carbonate and easily forming a cured product having good adhesion.

  The epoxy-modified silicone oil may be any of a double-ended epoxy-modified silicone oil, a single-ended epoxy-modified silicone oil, a side-chain epoxy-modified silicone oil, and a double-ended epoxy-modified silicone oil.

  The amount of coating with the organosilicon compound or a cured product thereof (content of the organosilicon compound or the cured product in the surface-treated calcium carbonate (B)) is 0.1 parts by mass or more with respect to 100 parts by mass of calcium carbonate as a raw material. It is preferably 10 parts by mass or less. When the content of the organosilicon compound or the cured product thereof in the surface-treated calcium carbonate (B) is 0.1 part by mass or more, the dispersibility of the surface-treated calcium carbonate (B) can be easily enhanced sufficiently. It is easy to increase the flowability of the resin composition, and to easily increase the mechanical strength of the molded body. When the content of the organosilicon compound or the cured product thereof in the surface-treated calcium carbonate (B) is 10 parts by mass or less, bleed out of the organosilicon compound is easily suppressed. The content of the organosilicon compound or the cured product thereof in the surface-treated calcium carbonate (B) is more preferably 0.2 parts by mass to 5 parts by mass with respect to 100 parts by mass of calcium carbonate, 0.5 parts by mass More preferably, it is 3 parts by mass or less.

The content of the organosilicon compound or the cured product thereof in the surface-treated calcium carbonate (B) may be calculated from the charged amount of the organosilicon compound, or NMR ( ²⁹ Si-NMR, ¹ H-NMR, and ¹³ C- It may be measured by NMR) or fluorescent X-ray analysis (XRF).

  The state of coating with the condensed phosphoric acid and the organosilicon compound or its cured product is not particularly limited, and the condensed phosphoric acid may be unevenly distributed near the surface of calcium carbonate, or the organosilicon compound is unevenly distributed near the surface of calcium carbonate. The condensed phosphoric acid and the organosilicon compound may be present uniformly. Among these, from the viewpoint of making it easier to improve the dispersibility of the surface-treated calcium carbonate (B), the condensed phosphoric acid is unevenly distributed in the vicinity of the surface of the calcium carbonate (the side close to the surface of the calcium carbonate), and the organosilicon compound is in the vicinity of the surface of the calcium carbonate. It is preferable that it is unevenly distributed in a region away from (a side far from the surface of calcium carbonate).

  The average particle size of the surface-treated calcium carbonate (B) may be about the same as the average particle size of calcium carbonate as a raw material, preferably 0.05 μm or more and 1 μm or less, and 0.08 μm or more and 0.5 μm or less It is more preferable that it is 0.1 μm or more and 0.3 μm or less. The average particle diameter of the surface-treated calcium carbonate (B) can be measured by the same method as described above.

The specific surface area of the surface-treated calcium carbonate (B) is preferably 0.5 m ² / g or more and 100 m ² / g or less. When the specific surface area is 0.5 m ² / g or more, the thixotropy is hardly impaired, and when it is 100 m ² / g or less, the particles are hardly aggregated and the dispersibility is not easily impaired. The specific surface area of the surface treated calcium carbonate (B) is more preferably at most 0.5 m ² / g or more ^{30 m} 2 / g, more preferably not more than 0.5 m ² / g or more ^{15 m} 2 / g. The specific surface area of the surface-treated calcium carbonate (B) can be measured by a BET (Brunauer-Emmett-Teller) method by nitrogen adsorption and desorption measurement.

(Method of producing surface treated calcium carbonate (B))
The surface treated calcium carbonate (B) is obtained by treating the surface of calcium carbonate as a raw material with condensed phosphoric acid and an organosilicon compound (specifically, surface treatment with condensed phosphoric acid and surface treatment with an organosilicon compound) To do).

(Surface treatment with condensed phosphoric acid)
The condensed phosphoric acid used for surface treatment is the same as that described above. The surface treatment with condensed phosphoric acid may be a wet treatment or a dry treatment.

  The wet treatment is a method in which condensed phosphoric acid is added to and mixed with an aqueous suspension of calcium carbonate, and then the calcium carbonate is filtered and dried. In this method, an alkali metal salt such as sodium salt or potassium salt of condensed phosphoric acid may be used. However, from the viewpoint of reducing the amount of alkali metal remaining in the surface-treated calcium carbonate (B), it is preferable to use it in the form of an acid, not in the form of an alkali metal salt.

  Dry processing is a method in which condensed phosphoric acid is added to and mixed with calcium carbonate powder and then dried. The condensed phosphoric acid can be added in the form of a solution.

(Surface treatment with organosilicon compound)
The organosilicon compound used for surface treatment is the same as that described above. The surface treatment with the organosilicon compound is preferably performed by a method (dry method) in which the organosilicon compound is added to and mixed with the calcium carbonate powder and then dried by heating. The organosilicon compound may be added as a solution in a solvent.

  The order of the surface treatment with condensed phosphoric acid and the surface treatment with organic silicon compound is not particularly limited, and after surface treatment with condensed phosphoric acid, surface treatment with organic silicon compound may be performed, or with organic silicon compound After the surface treatment, a surface treatment with condensed phosphoric acid may be performed, or a surface treatment with condensed phosphoric acid and a surface treatment with an organosilicon compound may be performed simultaneously. Among these, from the viewpoint of easily improving the fluidity of the polyester resin composition at the time of molding, it is preferable to perform a surface treatment with an organosilicon compound after performing a surface treatment with condensed phosphoric acid.

  The content of the surface-treated calcium carbonate (B) in the polyester resin composition of the present invention is that of the polyester resin (A), the surface-treated calcium carbonate (B), the surface-treated titanium oxide (C), and the inorganic filler (D). When the total is 100 parts by mass, it is preferably 3 parts by mass or more and 15 parts by mass or less. When the content of the surface-treated calcium carbonate (B) is 3 parts by mass or more, it is easy to improve the fluidity of the polyester resin composition, and a molded article having high mechanical strength is easily obtained. In addition, the discoloration after heating is further reduced to suppress a decrease in reflectivity, and cracks due to light irradiation are more likely to occur. When the content of the surface-treated calcium carbonate (B) is 15 parts by mass or less, not only the fluidity and moldability at the time of molding are not easily impaired, but also the initial reflectance is hardly impaired. The content of the surface-treated calcium carbonate (B) is 100 parts by mass with the total of the polyester resin (A), the surface-treated calcium carbonate (B), the surface-treated titanium oxide (C) and the inorganic filler (D), More preferably, they are 5 to 15 mass parts.

  The ratio of the phosphorus content to the content of the organosilicon compound or its cured product in the surface-treated calcium carbonate (B) is as follows: phosphorus: organic silicon compound or its cured product = 1: 0.1 to 1:10 (mass ratio) It is preferable that When the ratio of the phosphorus content is a certain level or more, it is difficult to cause cracks in the molded body due to a radical scavenging function by phosphorus, etc., and it is easy to suppress coloring after heating, and it is easy to further suppress a decrease in reflectance. . When the ratio of the content of the organosilicon compound or the cured product thereof is a certain value or more, the dispersibility of the surface-treated calcium carbonate (B) can be easily improved, so the fluidity of the polyester resin composition at the time of molding can be easily further improved. Strength can be further enhanced. In the surface-treated calcium carbonate (B), the ratio of the phosphorus content to the content of the organosilicon compound or its cured product is phosphorus: organosilicon compound or its cured product = 1: 0.5 to 1: 5 (mass ratio). It is more preferable that

1-3. Surface treatment titanium oxide (C)
The surface-treated titanium oxide (C) can whiten the polyester resin composition and further improve the light reflection function.

  The surface-treated titanium oxide (C) comprises titanium oxide and an organosilicon compound covering at least a part of the surface or a cured product thereof. Such surface-treated titanium oxide (C) can be obtained by surface-treating titanium oxide with an organosilicon compound.

  Further, the surface-treated titanium oxide (C) may further contain silicon oxide that covers at least a part of the surface of the titanium oxide, if necessary. Such surface-treated titanium oxide (C) can be obtained by surface-treating titanium oxide with silicon oxide and an organosilicon compound.

(Titanium oxide)
The crystal structure of titanium oxide is not particularly limited, and may be either anatase type or rutile type. Among them, rutile type is preferable from the viewpoint of improving the reflectance.

  The particle shape of titanium oxide is not particularly limited, but from the viewpoint of making the reflectance of the polyester resin composition more uniform, it is preferable that the aspect ratio is small, that is, a spherical shape.

  The average particle diameter of titanium oxide is preferably 0.1 μm or more and 0.5 μm or less, and more preferably 0.15 μm or more and 0.3 μm or less. The average particle diameter of titanium oxide can be measured by the same method as described above.

(Organosilicon compound or its cured product or surface coating with silicon oxide)
The organosilicon compound or its cured product, optionally silicon oxide, covers at least a part of the surface of titanium oxide. That is, the coating covering at least a part of the surface of titanium oxide contains the organosilicon compound or the cured product thereof, and may further contain silicon oxide etc. as required.

  Examples of the organosilicon compound in the "organosilicon compound or its cured product" include the same as the organosilicon compound in the above-mentioned surface-treated calcium carbonate (B).

  The total coating amount of organosilicon compound or its cured product and optional silicon oxide (total content of organosilicon compound and its cured product and optional silicon oxide in surface-treated titanium oxide (C)) It is preferable that it is 0.01 to 2.0 mass parts with respect to 100 mass parts, and it is more preferable that it is 0.05 to 2.0 mass parts. It is easy to increase the dispersibility of the surface-treated titanium oxide (C) in the polyester resin composition when the content is a certain amount or more, easily improve the flowability of the polyester resin composition at the time of molding, and have high mechanical strength. It is easy to get a body. Moreover, it is easy to obtain a molded article having high whiteness and high reflectance.

  Examples of silicon oxide include silicon dioxide.

(Surface coating with aluminum oxide)
The coating covering at least a part of the surface of titanium oxide may further contain an aluminum oxide as necessary.

  Examples of aluminum oxide include anhydrous oxide of aluminum, hydrous oxide, hydrated oxide, hydroxide and the like.

  The coating amount with aluminum oxide (the content of aluminum oxide in the surface-treated titanium oxide (C)) is 0.1 to 5.0 parts by mass with respect to 100 parts by mass of titanium oxide as a raw material. It is more preferable that it is 0.3 parts by mass or more and 3.0 parts by mass or less. The content of aluminum oxide in the surface-treated titanium oxide (C) can be measured by fluorescent X-ray analysis or ICP emission spectral analysis.

  Examples of commercially available surface-treated titanium oxide (C) include Typek PC-3 (manufactured by Ishihara Sangyo Co., Ltd., average primary particle size 0.21 μm, alumina hydrate compound, silica hydrate compound and organosilicon compound) Titanium oxide), Typek CR-63, CR-61 (manufactured by Ishihara Sangyo Co., Ltd., alumina hydrate compound, silica hydrate compound and titanium oxide coated with organosilicon compound), and the like.

  The average particle size (average primary particle size) of the surface-treated titanium oxide (C) is about the same as the average particle size of titanium oxide as a raw material, and is preferably 0.003 μm or more and 0.1 μm or less. When the average particle diameter of the surface-treated titanium oxide (C) is 0.003 μm or more, it is easy to disperse well in the polyester resin composition, and when it is 0.1 μm or less, the surface smoothness of the resulting molded article is impaired. It is hard to be scolded. The average particle diameter of the surface-treated titanium oxide (C) is more preferably 0.01 μm or more and 0.06 μm or less. The average particle diameter of the surface-treated titanium oxide (C) can be measured by the same method as described above.

(Method for producing surface-treated titanium oxide (C))
The surface-treated titanium oxide (C) can be obtained by treating the surface of titanium oxide with an alkali metal silicate (sodium silicate, potassium silicate, etc.) and / or with an organosilicon compound.

  The surface treatment with the alkali metal silicate can be performed by a known method, for example, a method described in JP-A No. 2003-112923, JP-A No. 8-48940, JP-A No. 2007-246351, or the like. For example, titanium oxide is dispersed in water so as to be 0.1% by mass or more and 10% by mass or less to obtain a dispersion. To the resulting dispersion, a metal hydroxide such as sodium hydroxide or potassium hydroxide, a basic nitrogen compound such as ammonia or a quaternary amine is added, and the pH is adjusted to 9-12. The temperature of the dispersion is adjusted to 50 to 100 ° C., and an alkali metal silicate such as sodium silicate or potassium silicate is continuously or intermittently added thereto as a silica source to oxidize the surface of titanium oxide Deposit silicon. Thereby, titanium oxide (surface-treated titanium oxide (C)) in which at least a part of the surface is coated with silicon oxide can be obtained. The obtained surface-treated titanium oxide (C) may be further subjected to heat aging, washing, concentration, drying and the like, if necessary.

  The surface treatment with the organosilicon compound may be performed by a known method or by the same method as described above. The organosilicon compound used for surface treatment is the same as that described above.

  The content of the surface-treated titanium oxide (C) in the polyester resin composition of the present invention is the total of the polyester resin (A), the surface-treated calcium carbonate (B), the surface-treated titanium oxide (C) and the inorganic filler (D) Is preferably 10 parts by mass or more and 50 parts by mass or less. When the content of the surface-treated titanium oxide (C) is 10 parts by mass or more, the whiteness of the polyester resin composition is likely to increase and the reflectance is likely to increase. When the content of the surface-treated titanium oxide (C) is 50 parts by mass or less, the fluidity, moldability, and mechanical strength at the time of molding are hardly impaired. The content of the surface-treated titanium oxide (C) is 100 parts by mass of the total of the polyester resin (A), the surface-treated calcium carbonate (B), the surface-treated titanium oxide (C) and the inorganic filler (D) More preferably, it is 10 to 30 mass parts.

  The mass ratio of the surface-treated calcium carbonate (B) to the surface-treated titanium oxide (C) in the polyester resin composition of the present invention is (B): (C) = 10: 90 to 60:40 (mass ratio) It is preferably 10:90 to 50:50 (mass ratio), more preferably 10:90 to 45:55 (mass ratio). If the content mass ratio of the surface-treated calcium carbonate (B) is above a certain level, the fluidity during molding tends to increase, so the mechanical strength of the resulting molded product tends to increase, making cracks less likely to occur or after heating. It is easy to suppress the decrease of the reflectance of When the content mass ratio of the surface-treated calcium carbonate (B) is a certain value or less, the initial reflectance (because the content mass ratio of the surface-treated titanium oxide (C) is not too small) is unlikely to be impaired.

  The total content of the surface-treated calcium carbonate (B) and the surface-treated titanium oxide (C) in the polyester resin composition of the present invention is 45 to 130 parts by mass with respect to the total mass of the polyester resin (A). It is preferable that it is 50 parts by mass or more and 120 parts by mass or less. When the total content of the surface-treated calcium carbonate (B) and the surface-treated titanium oxide (C) is within the above range, the whiteness can be easily enhanced without impairing the flowability of the polyester resin composition, and the reflectance is further increased. Easy to increase.

1-4. Inorganic filler (D)
The inorganic filler (D) is a filler of an inorganic compound having a spherical, fibrous or plate shape. From the viewpoint of further enhancing the strength and toughness of the polyester resin composition, the shape of the inorganic filler (D) is preferably fibrous.

  Examples of fibrous inorganic fillers (D) 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 etc. are included. One of these may be used alone, or two or more may be used in combination. Among them, wollastonite, glass fibers, potassium titanate whiskers are preferable, and wollastonite or glass fibers are more preferable, since the average fiber diameter is relatively small and the surface smoothness of the molded product (reflecting material) can be easily improved. . From the viewpoint of further enhancing the light shielding effect of the polyester resin composition, wollastonite is preferable, and from the viewpoint of further increasing the mechanical strength of the polyester resin composition, glass fiber is preferable.

  The average fiber length (l) of the fibrous inorganic filler (D) is usually 5 mm or less, from the viewpoint of making the fibrous inorganic filler (D) difficult to break and easy to finely disperse in the resin. And 4 mm or less. The average fiber length (l) of the fibrous inorganic filler (D) is preferably 2 μm or more and more preferably 8 μm or more from the viewpoint of further increasing the strength of the polyester resin composition.

  The aspect ratio (average fiber length (l) / average fiber diameter (d)) of the fibrous inorganic filler (D) is preferably 5 or more and 2000 or less, and more preferably 30 or more and 600 or less. The greater the aspect ratio, the higher the strength and rigidity of the polyester resin composition.

The average fiber length (l) and the average fiber diameter (d) of the fibrous inorganic filler (D) in the polyester resin composition can be measured by the following method.
1) The polyester resin composition is dissolved in a hexafluoroisopropanol / chloroform solution (0.1 / 0.9% by volume), followed by filtration to collect the filtrate obtained.
2) Arbitrary 100 fibrous inorganic fillers (D) of the obtained filtrate are observed with a scanning electron microscope (SEM) (magnification: 50 times), and the length and diameter of each fiber are measured. To do. And the average value of fiber length can be made into an average fiber length (1), and the average value of a fiber diameter can be made into an average fiber diameter (d).

  The content of the inorganic filler (D) in the polyester resin composition of the present invention is the total of the polyester resin (A), surface-treated calcium carbonate (B), surface-treated titanium oxide (C) and inorganic filler (D) When it is 100 parts by mass, it is preferably 5 parts by mass or more and 30 parts by mass or less. If the content of the inorganic filler (D) is 10 parts by mass or more, the heat resistance and strength of the polyester resin composition can be easily increased, and if it is 25 parts by mass or less, the flowability during molding of the polyester resin composition Formability is not easily impaired. The content of the inorganic filler (D) is 10 when the total of polyester resin (A), surface treated calcium carbonate (B), surface treated titanium oxide (C) and inorganic filler (D) is 100 parts by mass. More preferably, it is in the range of not less than 25 parts by mass.

1-4. Other ingredients (E)
The polyester resin composition for a reflector according to the present invention may be any component other than the above components (A) to (D) according to the use, as long as the effects of the present invention are not impaired. , Amines, sulfurs, organic phosphorus, etc.), light stabilizers (benzotriazoles, triazines, benzophenones, hindered amines, ogizanides, etc.), heat stabilizers (lactone compounds, vitamin E, hydroquinones, Copper halides, iodine compounds, etc.), other polymers (olefins such as polyolefins, ethylene / propylene copolymers, ethylene / 1-butene copolymers, olefins such as propylene / 1-butene copolymers) Copolymer, polystyrene, polyamide, polycarbonate, polyacetal, polysulfone, polyphenylene oxy , Fluororesins, silicone resins, LCP, etc.), flame retardants (bromine, chlorine, phosphorus, antimony, inorganic, etc.), optical brighteners, plasticizers, thickeners, antistatic agents, release agents, It may further contain additives such as pigments, nucleating agents, and lubricants. The total content of the other components may be 10% by mass or less, preferably 5% by mass or less, based on the total mass of the polyester resin composition for a reflector.

  Especially, it is preferable that the polyester resin composition for reflective materials of this invention contains antioxidant. Examples of such antioxidants include phenols (including hindered phenols). The phenols are compounds having a phenol skeleton or a hindered phenol skeleton. Examples of phenols include 2,6-di-tert-butyl-4-hydroxytoluene (BHT), pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadodecyl- 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate and the like. Examples of commercially available products include IRGANOX 1010, 1076, 1726 (above, manufactured by BASF Japan).

  The content of the antioxidant is 2.5 masses when the total of the polyester resin (A), the surface-treated calcium carbonate (B), the surface-treated titanium oxide (C), and the inorganic filler (D) is 100 parts by mass. Part or less, preferably 1 part by weight or less.

1-5. Physical Properties The reflectance of light with a wavelength of 450 nm of the polyester resin composition for a reflective material of the present invention is preferably 90% or more, and more preferably 94% or more. The reflectance can be measured by using a molded product obtained by molding the polyester resin composition for a reflector of the present invention as a test piece, and the reflectance of the test piece is measured using CM3500d manufactured by Konica Minolta. The thickness of the sample piece can be 0.5 mm.

  The reflectance of light having a wavelength of 450 nm measured after heating at 150 ° C. for 500 hours of the polyester resin composition for a reflector of the present invention can be, for example, 90% or more. The method of measuring the reflectance after heating is the same as described above. In order to reduce the decrease in reflectance after heating, it is preferable to combine the surface-treated calcium carbonate (B) and the surface-treated titanium oxide (C) with the polyester resin composition as described above.

2. Method for Producing Polyester Resin Composition for Reflector The polyester resin composition of the present invention comprises at least the above-mentioned component (A), component (B), component (C) and component (D) by a known method such as a Henschel mixer. , V blender, ribbon blender, or tumbler blender, or after the above mixing, further melt kneading with a single screw extruder, multi-screw extruder, kneader or Banbury mixer, and granulating or grinding after the melt kneading It can be manufactured by a method.

  Melt-kneading is preferably performed at a temperature 5 to 30 ° C. higher than the melting point of the polyester resin (A). The preferable lower limit of the temperature of melt kneading can be 275 ° C., more preferably 295 ° C., and the preferable upper limit can be 360 ° C., more preferably 340 ° C.

3. Reflective material The reflective material of the present invention is a molded article obtained by molding the polyester resin composition for reflective material of the present invention.

  The molding can be performed by a known molding method. Examples of known molding methods include injection molding, insert molding including hoop molding, melt molding, extrusion molding, inflation molding, and blow molding.

  The reflective material of the present invention is a molded body having at least a light reflecting surface, and can have any shape depending on the application. For example, the reflector of the present invention may be a casing, a housing or the like having at least a surface that reflects light. The surface that reflects light may be a plane or a curved surface (including a spherical surface). Specifically, the light reflecting surface may have a box shape, a funnel shape, a bowl shape, a parabolic shape, a cylindrical shape, a conical shape, a honeycomb shape, or the like.

  The reflective material of the present invention is used as a reflective material of various light sources such as organic EL and light emitting diode (LED). Especially, it is preferable to be used as a reflective material of a light emitting diode (LED), and it is more preferable to be used as a reflective material of a light emitting diode (LED) corresponding to surface mounting.

  The LED package having the reflective material of the present invention as a reflector of a light emitting diode (LED) comprises: a substrate; a housing portion provided on the substrate and having a space for mounting the LED; It can have LED and the sealing member which seals LED. And the housing part which has the space for mounting LED can be used as the reflecting material of this invention. In such an LED package, 1) forming a reflection plate on a substrate to obtain a housing part; 2) placing the LED in the housing part and electrically connecting the LED to the substrate; 3) It can be manufactured through a process of sealing the LED with a sealant. In the sealing step, the sealant is heated at a temperature of 100 to 200 ° C. and thermally cured. Furthermore, in the reflow soldering process when mounting the LED package on the printed board, the LED package is exposed to a high temperature of 250 ° C. or higher.

  The reflector obtained from the polyester resin composition for a reflector of the present invention comprises surface-treated calcium carbonate (B) and surface-treated titanium oxide (C). As a result, even when exposed to high-temperature heat in the sealing process or reflow soldering process, or subjected to heat or light generated from the LED in a use environment for a long time, there is little discoloration and less decrease in reflectance. . Therefore, a high reflectance can be maintained over a long period.

  Such an LED package can be used, for example, for electric and electronic components, indoor lighting, outdoor lighting, automobile lighting, and the like.

  The invention will now 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)>
(Synthesis of polyester resin (A-1))
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, and then 0.1027 parts by mass of tetrabutyl titanate was introduced to carry out a polycondensation reaction. In the polycondensation reaction, the pressure was gradually reduced from normal pressure to 1 Torr over 85 minutes, and at the same time, the temperature was raised 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 (A-1).

  The polyester resin (A-1) obtained had an intrinsic viscosity [η] of 0.6 dl / g and a melting point of 290 ° C. The intrinsic viscosity [η] and the melting point were measured by the following methods.

(Intrinsic viscosity)
The obtained polyester resin (A-1) was dissolved in a 50/50% by mass mixed solvent of phenol and tetrachloroethane to prepare a sample solution. The number of seconds of flow of the obtained sample solution was measured using a Ubbelohde viscometer under conditions of 25 ° C. ± 0.05 ° C., and the limiting viscosity [η] was calculated by applying the following formula.
[Η] = ηSP / [C (1 + kηSP)]
[Η]: Intrinsic viscosity (dl / g)
ηSP: specific viscosity C: sample concentration (g / dl)
t: Seconds of flow of sample solution (seconds)
t0: Second drop of solvent (seconds)
k: Constant (Slope determined by measuring the specific viscosity of samples (three or more points different in solution concentration), plotting the solution concentration on the abscissa and ηSP / C on the ordinate)
ηSP = (t−t0) / t0

(Melting point (Tm))
The melting point (Tm) was measured by a differential scanning calorimeter (DSC) in accordance with JIS-K7121. Specifically, a DSC measurement pan in which a sample is enclosed is set in X-DSC7000 (manufactured by SII), and the temperature is raised to 320 ° C. at a temperature rising rate of 10 ° C./min in a nitrogen atmosphere. After holding for a minute, the temperature was lowered to 30 ° C. by measuring the temperature at 10 ° C./min. And the temperature of the peak top of the endothermic peak at the time of temperature rising was made into "melting point."

<Calcium carbonate>
Surface-treated calcium carbonate (B-1): CALCEO P015P (manufactured by Shiraishi Kogyo Co., Ltd., pyrophosphoric acid treatment + epoxy-modified silicone oil treatment, phosphorus content: 0.5% by mass (vs. surface-treated calcium carbonate (B-1)), Content of epoxy-modified silicone oil: 0.9% by mass (relative to calcium carbonate)
Surface treated calcium carbonate (b-1): RK 75 NC (manufactured by Shiroishi Kogyo Co., Ltd., treated with pyrophosphate only, phosphorus content: 0.5% by mass (vs. surface treated calcium carbonate (b-1))

  Physical properties of the surface-treated calcium carbonate (B-1) and (b-1) are shown in Table 1.

  The average particle diameter, BET specific surface area, phosphorus content, and epoxy-modified silicone oil content of surface-treated calcium carbonate (B-1) and (b-1) were measured by the following methods.

(Average particle size)
First, electron microscopic photographs of 100 arbitrary surface-treated calcium carbonates were observed. Based on the obtained transmission electron micrograph, an amount of mass (% by mass) in each particle size section of the primary particles was plotted using an image diffractometer (Luzex IIIU) to obtain a distribution curve. A cumulative distribution curve is obtained from the obtained distribution curve, and a value at a cumulative degree of 50% by mass in this cumulative distribution curve is defined as an average particle diameter.

(BET specific surface area)
The nitrogen adsorption / desorption measurement was performed by the BET (Brunauer-Emmett-Teller) method.

(Phosphorus content)
It was measured by ICP emission spectrometry.

(Epoxy-modified silicone oil content)
NMR ( ²⁹ Si-NMR, ¹ H-NMR, and ¹³ C-NMR), X-ray fluorescence analysis (XRF) and ICP emission spectroscopy were used.

<Titanium oxide>
Surface-treated titanium oxide (C-1): Taipei PC-3 (produced by Ishihara Sangyo Co., Ltd., rutile TiO ₂ (manufactured by the chloride process, then coated with alumina hydrate compound, silica hydrate compound and organosilicon compound) Titanium oxide), average particle size: 0.21 μm)
Titanium oxide (c-1): Taipek CR-60 (manufactured by Ishihara Sangyo Co., Ltd., rutile TiO ₂ (without surface treatment), average particle size: 0.2 μm)

  The average particle diameter of titanium oxide was measured by the same method as the average particle diameter of calcium carbonate.

<Inorganic filler (D)>
Glass fiber: average fiber length (l) 3 mm, average fiber diameter (R) 6.5 μm, aspect ratio (l / R) 462 (ECS03T-171DE / P9W manufactured by Nippon Electric Glass Co., Ltd., silane compound treated product)
The average fiber length (l) and average fiber diameter (R) of the glass fiber were measured as follows.

(Average fiber length, average fiber diameter)
That is, the fiber length and the fiber diameter of 100 arbitrary ones of the inorganic filler (D) were each measured by 50 times using a scanning electron microscope (SEM). And the average value of the obtained fiber length was made into an average fiber length, and the average value of the obtained fiber diameter was made into an average fiber diameter. The aspect ratio was an average fiber length / average fiber diameter.

<Antioxidant (E)>
Irganox 1010 (manufactured by BASF, tetrakis [3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionic acid] pentaerythritol)

2. Preparation and Evaluation of Polyester Resin Composition <Examples 1 to 3 and Comparative Examples 1 to 4>
Polyester resin (A), calcium carbonate, titanium oxide, inorganic reinforcing material (D) and antioxidant (E) were mixed in a tumbler blender at the composition ratio shown in Table 1. The obtained mixture was melt-kneaded at a cylinder temperature of 300 ° C. with a twin-screw extruder (TEX30α manufactured by Nippon Steel Works) and then extruded into a strand shape. After cooling the extrudate in a water bath, the strand was pulled up with a pelletizer and cut to obtain a pellet-like polyester resin composition.

  The reflection characteristics (initial, after heating, after light irradiation), fluidity, cracks and bending strength of the obtained polyester resin composition were evaluated by the following methods.

<Reflection characteristics>
(Initial reflectance)
The obtained polyester resin composition was injection-molded under the following molding conditions using the following molding machine to produce a test piece having a length of 30 mm, a width of 30 mm, and a thickness of 0.5 mm.
Molding machine: Sumitomo Heavy Industries, Ltd. SE50DU
Cylinder temperature: Melting point (Tm) + 10 ° C of polyester resin (A)
Mold temperature: 150 ° C

  The reflectance of the wavelength region 360nm -740nm was calculated | required for the obtained test piece using Konica Minolta CM3500d. And the reflectance of wavelength 450nm was made into the initial stage reflectance.

(Reflectance after heating)
The test piece for which the initial reflectance was measured was left in an oven at 150 ° C. for 500 hours. Thereafter, the reflectance of the obtained sample piece was measured in the same manner as the initial reflectance. And the reflectance of wavelength 450nm was made into the reflectance after a heating.

(Reflectance after 500 hr light irradiation)
The test piece for which the initial reflectance was measured was left for 500 hours in the following ultraviolet irradiation device. Then, the reflectance of the obtained sample piece was measured by the method similar to initial stage reflectance, and it was set as the reflectance after ultraviolet irradiation.
Ultraviolet irradiation device: Daipura Wintes Co., Ltd. Super Winmini Output: 16 mW / cm ²

<Crack>
The obtained polyester resin composition was injection molded using the following injection molding machine under the following molding conditions to prepare a test piece having a length of 30 mm, a width of 30 mm, and a thickness of 0.5 mm.
Molding machine: Sumitomo Heavy Industries, Ltd. SE50DU
Cylinder temperature: Melting point (Tm) + 10 ° C of polyester resin (A)
Mold temperature: 150 ° C

The prepared test piece was allowed to stand in the following environmental tester under the following conditions, and 2.5 W of LED light was placed at a position of 0.4 mm from the surface of the test piece and irradiated. The surface of the test piece was observed for the presence of a crack by an optical microscope every day, and the number of days required for the crack to occur was counted.
Environmental tester: ESPEC PWL-3KP
Environmental test conditions: 85 ° C, 85% RH
Optical microscope: Omron VC4500
Optical microscope conditions: 500 times

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

<Bending strength (elastic modulus)>
The obtained polyester resin composition was injection molded using the following injection molding machine under the following molding conditions to prepare a test piece having a length of 64 mm, a width of 6 mm, and a thickness of 0.8 mm.
Injection molding machine: Sodic TUPARL TR40S3A
Molding machine cylinder temperature: melting point (Tm) + 10 ° C of polyester resin (A)
Mold temperature: 150 ° C

  The obtained test piece was allowed to stand for 24 hours in a nitrogen atmosphere at a temperature of 23 ° C. Next, a bending test was performed under an atmosphere of temperature 23 ° C. and relative humidity 50%: bending tester AB5 manufactured by INTESCO, span 26 mm, bending speed 5 mm / min, and strength (elastic modulus) was measured.

  Table 2 shows the compositions and evaluation results of the polyester resin compositions of Examples 1 to 3 and Comparative Examples 1 to 4.

  As shown in Table 2, Example 1 was a combination of surface-treated titanium oxide (C-1) treated with an organosilicon compound and surface-treated calcium carbonate (B-1) treated with phosphoric acid and an organosilicon compound. It can be seen that the polyester resin composition has good fluidity during molding, and the resulting molded product has high bending strength. Moreover, the molded object obtained from the polyester resin composition of Examples 1-3 has little fall of a reflectance even if it exposes to high temperature, and the crack generation in a short time is also suppressed (crack generation can be delayed. I understand that).

  On the other hand, the polyester resin composition of Comparative Example 1 containing no surface treated calcium carbonate (B-1), or the polyester resin composition of Comparative Example 4 containing too little content of surface treated calcium carbonate (B-1) It can be seen that cracks occur in a short time.

  Moreover, it turns out that the polyester resin composition of the comparative example 2 containing the surface treatment calcium carbonate (b-1) which performed only phosphoric acid treatment has low fluidity, and the bending strength of the obtained molded object is also low. It is considered that this is because the dispersibility of the surface-treated calcium carbonate (b-1) is insufficient. Moreover, it turns out that the polyester resin composition of the comparative example 2 is easy to produce a crack also in a short time.

  In addition, it is understood that the polyester resin composition of Comparative Example 3 including the untreated titanium oxide (c-1) has a low initial reflectance, and cracks are easily generated in a short time.

  According to the present invention, the fluidity at the time of molding processing is excellent, the mechanical strength is high, the reflectance decreases when exposed to high temperature for a long time, and cracks occur when irradiated with light for a certain time or longer. The present invention can provide a polyester resin composition for a reflector that can impart a reflector that is less likely to cause

Claims (11)

A polyester resin (A) having a melting point (Tm) or glass transition temperature (Tg) measured by a differential scanning calorimeter (DSC) of not less than 270 ° C. and not less than 30 parts by weight and not more than 80 parts by weight;
3 parts by mass or more and 15 parts by weight of surface-treated calcium carbonate (B) having an average particle size of 0.05 μm or more and 1 μm or less, including calcium carbonate and condensed phosphoric acid and an organosilicon compound covering at least a part of the surface thereof or a cured product thereof Below mass parts,
10 parts by mass or more and 50 parts by mass or less of surface-treated titanium oxide (C) containing titanium oxide and an organosilicon compound covering at least a part of the surface thereof or a cured product thereof
And 5 to 30 parts by mass of the inorganic filler (D) (provided that the total of (A), (B), (C) and (D) is 100 parts by mass),
The content mass ratio (B) :( C) of the surface treated calcium carbonate (B) to the surface treated titanium oxide (C) is 10:90 to 60:40.
Polyester resin composition for reflectors. The phosphorus content in the surface-treated calcium carbonate (B) is 0.2 parts by mass or more and 2 parts by mass or less with respect to 100 parts by mass of the surface-treated calcium carbonate (B).
The polyester resin composition for a reflector according to claim 1. The content of the organosilicon compound or the cured product thereof in the surface-treated calcium carbonate (B) is 0.1 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the calcium carbonate.
The polyester resin composition for a reflector according to claim 1 or 2. The organosilicon compound or the cured product thereof in the surface-treated calcium carbonate (B) is a cured product of an epoxy-modified silicone,
The polyester resin composition for reflectors as described in any one of Claims 1-3. The surface-treated titanium oxide (C) may further contain silicon oxide which covers at least a part of the surface of the titanium oxide,
The total content of the organosilicon compound or the cured product thereof and the silicon oxide is 0.01 parts by mass or more and 2 parts by mass or less with respect to 100 parts by mass of the titanium oxide.
The polyester resin composition for reflectors as described in any one of Claims 1-4. The polyester resin (A) contains a component unit (a1) derived from a dicarboxylic acid and a component unit (a2) derived from a dialcohol,
The component unit (a1) derived from the dicarboxylic acid is 30 mol% or more and 100 mol% or less of the component unit derived from terephthalic acid with respect to a total of 100 mol% of the component unit (a1) derived from the dicarboxylic acid. And 0 to 70 mol% of component units derived from an aromatic dicarboxylic acid other than terephthalic acid,
The component unit (a2) derived from the dialcohol includes at least one of a component unit derived from an alicyclic dialcohol having 4 to 20 carbon atoms and a component unit derived from an aliphatic dialcohol.
The polyester resin composition for reflectors as described in any one of Claims 1-5. The component unit (a2) derived from the dialcohol includes a component unit derived from an alicyclic dialcohol having a cyclohexane skeleton,
The polyester resin composition for a reflector according to claim 6. The component unit (a2) derived from the dialcohol is 30 mol% or more of the component unit derived from 1,4-cyclohexanedimethanol with respect to a total of 100 mol% of the component unit (a2) derived from the dialcohol. 100 mol% or less, and 0 mol% or more and 70 mol% or less of component units derived from the aliphatic dialcohol,
The polyester resin composition for a reflector according to claim 6 or 7. The inorganic filler (D) is glass fiber,
The polyester resin composition for reflectors as described in any one of Claims 1-8. The polyester resin composition for a reflector according to any one of claims 1 to 9,
Reflective material. A reflective material for a light emitting diode element;
The reflector according to claim 10.