JP2018168288A - Polyester resin composition for reflector, and reflector - Google Patents

Abstract

To provide a polyester resin composition for reflector which can suppress occurrence of out gas during molding and packaging while enhancing flowability and releasability during molding.SOLUTION: A polyester resin composition for reflector contains: 30 to 80 mass% of a polyester resin A having a melting point Tm or a glass transition temperature Tg measured by DSC of 250°C or higher; 0.01 to 10 mass% of a thermoplastic resin B which has a polyolefin skeleton and an aromatic hydrocarbon structure and has an intrinsic viscosity [η] measured at 135°C in decalin of 0.04 to 1.0 dl/g; 0.01 to 10 mass% of a thermoplastic resin C which has a polyolefin skeleton, and has a ratio [η]/[η] of an intrinsic viscosity [η] measured at 135°C in decalin to the intrinsic viscosity [η] of the thermoplastic resin B of more than 1 and 25 or less; 5 to 50 mass% of a white pigment D; and 5 to 50 mass% of an inorganic filler E.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, display backlights, and the like, taking advantage of 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 package includes a housing part (reflecting material) formed on a substrate and having a space for mounting the LED, the LED disposed in the housing, and a sealing member for sealing the LED. . A housing part (reflecting material) is manufactured by shape | molding the molten resin composition with a metal mold | die, for example. At that time, in order to obtain a housing part (reflecting material) with high shape accuracy, it is desired that the molten resin composition in the mold has high fluidity and excellent moldability. Furthermore, it is desired that the molded resin composition can be satisfactorily released from the mold.

  As materials used for the reflector, for example, Patent Document 1 discloses 1,4-cyclohexanedimethanol terephthalate (polyester resin (A)), styrene-modified polyolefin wax (thermoplastic resin (B2)), and titanium oxide (white). A thermoplastic resin composition for a reflector comprising a pigment (C)) and calcium carbonate whiskers (inorganic filler (D)) is disclosed. Such a thermoplastic resin composition containing the thermoplastic resin (B2) has been shown to have excellent fluidity and moldability during molding.

  The LED package manufactured in this way is mounted on a printed circuit board by reflow soldering, for example. In this reflow soldering process, the LED package is exposed to a high temperature of 250 ° C. or higher.

International Publication No. 2013/018360

  However, a thermoplastic resin composition containing a styrene-modified polyolefin wax sometimes generates outgas when being molded in a mold. As a result, mold contamination may occur. Further, outgas may be generated from the molded product (reflective material) due to the heat of the reflow soldering process when the LED package having the molded product (reflective material) obtained after molding is mounted on the flexible substrate. Thereby, there exists a possibility that the adhesiveness of a LED package and a flexible substrate may be impaired.

  The present invention has been made in view of the above circumstances, and provides a polyester resin composition for a reflector that can suppress the occurrence of outgas during molding or mounting while enhancing fluidity and mold release during molding. For the purpose.

[1] The polyester resin A having a melting point Tm or a glass transition temperature Tg measured by a differential scanning calorimeter (DSC) of 250 ° C. or higher is 30 to 80% by mass, a polyolefin skeleton and an aromatic hydrocarbon structure, And 0.01-10 mass% of thermoplastic resin B whose intrinsic viscosity [η _B ] measured at 135 ° C. in decalin is 0.01-1.0 dl / g, having a polyolefin skeleton, and in decalin The ratio [η _C ] / [η _B ] of the intrinsic viscosity [η _C ] measured at 135 ° C. to the intrinsic viscosity [η _B ] of the thermoplastic resin B is more than 1 and 25 or less. 01 to 10% by mass, white pigment D to 5 to 50% by mass, and inorganic filler E to 5 to 50% by mass (provided that the polyester resin A, the thermoplastic resin B, and the thermoplastic resin C) The white pigment D and Serial sum of the inorganic filler E is 100 wt%), reflective materials for the polyester resin composition.
[2] The polyester resin composition for a reflector according to [1], wherein the thermoplastic resin C is a polyolefin wax having no functional group structural unit and satisfies the following (i) to (iv).
(I) Density is 900 to 985 kg / m ³
(Ii) Melting point is 65 to 165 ° C
(Iii) Number average molecular weight Mn is 400 to 10,000
(Iv) The ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn is 1.5 to 5.5.
[3] The polyester resin composition for reflectors according to [2], wherein the thermoplastic resin C is a polyethylene-based wax having no functional group structural unit.
[4] The polyester for reflector according to any one of [1] to [3], wherein the mass ratio B / C of the thermoplastic resin B and the thermoplastic resin C is 0.01 to 1.0. Resin composition.
[5] The total content of the thermoplastic resin B and the thermoplastic resin C is the sum of the polyester resin A, the thermoplastic resin B, the thermoplastic resin C, the white pigment D, and the inorganic filler E. The polyester resin composition for reflectors according to [4], which is 0.1 to 15% by mass relative to the mass.
[6] A dicarboxylic acid component unit in which the polyester resin A 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, And a dialcohol component unit including 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 polyester resin composition for reflectors as described.
[7] The polyester resin composition for a reflector according to [6], wherein the component unit derived from the alicyclic dialcohol has a cyclohexane skeleton.
[8] The dialcohol component unit includes 30 to 100 mol% of a component unit derived from cyclohexanedimethanol and 0 to 70 mol% of a component unit derived from the aliphatic dialcohol [6] or [7 ] The polyester resin composition for reflectors as described in any one of Claims 1-3.
[9] The polyester resin composition for a reflector according to any one of [1] to [8], wherein the white pigment D is titanium oxide.
[10] A reflector obtained by molding the polyester resin composition for a reflector according to any one of [1] to [9].
[11] The reflective material according to [10], which is a reflective material for a light-emitting diode element.

  The polyester resin composition for a reflector according to the present invention provides a polyester resin composition for a reflector that can suppress the occurrence of outgas during molding or mounting while improving fluidity and mold release during molding. it can.

  The inventors of the present invention have analyzed the outgas component and found that it is a long-chain alkylene or an aromatic hydrocarbon (such as styrene) derived from the thermoplastic resin B. In other words, the thermoplastic resin B having an aromatic hydrocarbon structure can improve the fluidity and releasability of the polyester resin composition at the time of molding, while being easily decomposed and volatilized by heat, causing outgassing. I found.

On the other hand, the present inventors use the thermoplastic resin B and the thermoplastic resin C having an intrinsic viscosity ratio [η _C ] / [η _B ] satisfying a predetermined range in combination, thereby forming a polyester during molding. It has been found that outgassing can be reduced without impairing the fluidity and releasability of the resin composition. Specifically, even when the thermoplastic resin C is used in combination, even if the content ratio of the thermoplastic resin B in the polyester resin composition is reduced, fluidity and releasability (particularly fluidity) are not impaired. It has been found that outgas can be effectively reduced.

  The reason for this is not clear, but is presumed as follows. That is, since the thermoplastic resin C has a relatively high intrinsic viscosity, it does not easily decompose or volatilize due to heat. In addition, since the thermoplastic resin C has a polyolefin skeleton, it is easily compatible with the thermoplastic resin B, and when used in combination with the thermoplastic resin B, the effect of improving fluidity and releasability is easily exhibited. Furthermore, since the thermoplastic resin B has a relatively low intrinsic viscosity and has an aromatic hydrocarbon structure, it is likely to be unevenly distributed on the surface of the polyester resin composition. As a result, even if the thermoplastic resin C is used in combination, that is, even if the content ratio of the thermoplastic resin B in the polyester resin composition is small, the fluidity and releasability of the polyester resin composition during molding is lowered. Therefore, it is considered that outgas can be reduced.

  Furthermore, it has been found that the outgas can be further reduced when the thermoplastic resin C is an unmodified polyolefin wax having a certain density or softening point. The present invention has been made based on these findings.

1. Polyester resin composition for reflective material The polyester resin composition for reflective material of the present invention includes a polyester resin A, a thermoplastic resin B, a thermoplastic resin C, a white pigment D, and an inorganic filler E.

1-1. Polyester resin A
The polyester resin A is derived from a dicarboxylic acid component unit (a1) containing a component unit derived from an aromatic dicarboxylic acid, a component unit derived from an alicyclic dialcohol having 4 to 20 carbon atoms, or an aliphatic dialcohol. And a dialcohol component unit (a2) containing component units.

  The dicarboxylic acid component unit (a1) preferably has 30 to 100 mol% of component units derived from terephthalic acid, and preferably 0 to 70 mol% of component units derived from aromatic dicarboxylic acids other than terephthalic acid. 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 polyester resin composition is further increased. The ratio 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 further preferably 0 to 40 mol%. However, the total amount of each component unit contained in the dicarboxylic acid component unit (a1) is 100 mol%.

  The component unit derived from terephthalic acid may be a component unit derived from terephthalic acid or a 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.

  Preferred examples of component units derived from aromatic dicarboxylic acids other than terephthalic acid include component units derived from isophthalic acid, 2-methylterephthalic acid, naphthalenedicarboxylic acid and combinations thereof, and esters of these aromatic dicarboxylic acids A component unit derived from (preferably an alkyl ester having 1 to 4 carbon atoms of an aromatic dicarboxylic acid) is included.

  The dicarboxylic acid component unit (a1) further includes a small amount of a component unit derived from an aliphatic dicarboxylic acid and a component unit derived from a polyvalent carboxylic acid having three or more carboxylic acid groups in the molecule, in addition to the above component units. But you can. The ratio of the component unit derived from the aliphatic dicarboxylic acid and the component unit derived from the polyvalent carboxylic acid contained in the dicarboxylic acid component unit (a1) may be 10 mol% or less in total.

  The number of carbon atoms in 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, adipic acid is preferred. Examples of component units derived from polyvalent carboxylic acids include tribasic acids including trimellitic acid and pyromellitic acid, and polybasic acids.

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

  The component unit derived from the alicyclic dialcohol can increase the heat resistance of the polyester resin composition and reduce water absorption. 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-cyclohexane. Diols, 1,4-cyclohexanedimethanol, 1,4-cycloheptanediol and 1,4-cycloheptanedimethanol are included. Among these, from the viewpoints 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 a cis / trans structure. From the viewpoint of further improving the heat resistance of the polyester resin composition, the polyester resin A is derived from an alicyclic dialcohol having a trans structure. It is preferable that more component units are included. Accordingly, 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.

  The component unit derived from the aliphatic dialcohol further enhances the melt fluidity of the polyester resin composition. 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) may include only one or both of a component unit derived from an alicyclic dialcohol and a component unit derived from an aliphatic dialcohol. The dialcohol component unit (a2) is derived from a component unit derived from an 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 preferably contained in an aliphatic dialcohol component unit in an amount of 0 to 70 mol%. Component unit derived from alicyclic dialcohol contained in dialcohol component unit (a2) (preferably component unit derived from dialcohol having cyclohexane skeleton, more preferably derived from 1,4-cyclohexanedimethanol The ratio of the component unit to be used is more preferably 50 to 100 mol%, still more 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%, further preferably 0 to 40 mol%. However, the total amount of each component unit contained in the dialcohol component unit (a2) is 100 mol%.

  The dialcohol component unit (a2) may further contain a small amount of a component unit derived from an aromatic dialcohol 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 dialcohol component unit (a2) can be, for example, 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 preferable lower limit of the melting point (Tm) or the glass transition temperature (Tg) is 270 ° C., more preferably 280 ° C. On the other hand, the preferable upper limit 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 (molded product of the polyester resin composition) in the reflow soldering process is suppressed. A melting point or glass transition temperature of 350 ° C. or lower is preferable because decomposition of the polyester resin A is suppressed during melt molding.

  The melting point (Tm) and the glass transition temperature (Tg) of the polyester resin A can be measured according to JIS-K7121 by a differential scanning calorimeter (DSC). Specifically, X-DSC7000 (made by SII) is prepared as a measuring apparatus. In this apparatus, a pan for DSC measurement in which a sample of polyester resin A was sealed was set, heated to 320 ° C. at a heating rate of 10 ° C./min in a nitrogen atmosphere, held at that temperature for 5 minutes, and then 10 ° C. The temperature is lowered to 30 ° C. with a temperature drop measurement per minute. 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 that extends the base line on the low temperature side to the high temperature side and the tangent line drawn at the point where the gradient of the step-like change part of the glass transition is maximized is the “glass transition temperature”. To do.

  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 polyester resin composition is further increased. The intrinsic viscosity of the polyester resin A can be adjusted to the above range by adjusting the molecular weight of the polyester resin A. Examples of methods 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.
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)

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. A preferred polyester resin A can be produced by, for example, 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). As described above, the intrinsic viscosity of the polyester resin A can be adjusted by blending a molecular weight modifier in the reaction system.

  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 It is. 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 mol 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. , Preferably 0 to 0.05 mol.

  The content of the polyester resin A in the polyester resin composition of the present invention is 30 when the total of the polyester resin A, the thermoplastic resin B, the thermoplastic resin C, the white pigment D, and the inorganic filler E is 100% by mass. -80 mass%. The content of the polyester resin A is more preferably 30 to 70% by mass, and further preferably 40 to 60% by mass. When the content of the polyester resin A is in the above range, a polyester resin composition having heat resistance sufficient to withstand the reflow soldering process is easily obtained without impairing moldability.

  The polyester resin composition of the present invention may further contain one or more kinds of polyester resins having different physical properties as required.

1-2. Thermoplastic resin B
The thermoplastic resin B is a thermoplastic resin having a polyolefin skeleton and an aromatic hydrocarbon structure, and having an intrinsic viscosity [η _B ] measured in decalin at 135 ° C. of 0.01 to 1.0 dl / g. . When the intrinsic viscosity [η _B ] is 0.01 dl / g or more, bleeding out of the thermoplastic resin B from the polyester resin composition can be easily suppressed, and a decrease in reflectance can also be suppressed. Moreover, it is easy to suppress outgas, odor, fuming, etc. during molding. If the intrinsic viscosity [η _B ] is 1.0 dl / g or less, the melt viscosity does not become too high, and the moldability is hardly impaired. The intrinsic viscosity [η _B ] of the thermoplastic resin B is preferably 0.03 to 0.5 dl / g, and more preferably 0.03 to 0.2 dl / g.

The intrinsic viscosity [η _B ] of the thermoplastic resin B can be measured by the following method.
About 20 mg of sample is dissolved in 15 ml of decalin to obtain a solution. The specific viscosity ηsp of the obtained solution is measured in an oil bath at 135 ° C. The solution is further diluted with 5 ml of decalin solvent, and the specific viscosity ηsp is measured in the same manner. This dilution operation is further repeated twice, and the value of ηsp / C when the concentration (C) is extrapolated to 0 is obtained as the intrinsic viscosity.
η _B = lim (ηsp / C) (C → 0 [molecular weight])

  The melt viscosity at 140 ° C. of the thermoplastic resin B is preferably 10 to 2000 mPa · s, and more preferably 30 to 1200 mPa · s. The viscosity can be measured with a Brookfield viscometer.

The density of the thermoplastic resin B is preferably 850 to 1000 kg / m ³ , and more preferably 900 to 1000 kg / m ³ . When the density is within the above range, the moldability of the polyester resin composition becomes good. The density of the thermoplastic resin B can be measured by a density gradient tube method according to JIS K7112.

  The melting point of the thermoplastic resin B is preferably 65 to 165 ° C, and more preferably 80 ° C or higher and lower than 110 ° C. If the melting point is below a certain level, the moldability of the polyester resin composition is likely to be improved, and if it is above a certain level, bleeding out of the thermoplastic resin B is likely to be suppressed. The melting point can be measured in the same manner as the method for measuring the melting point of the polyester resin A.

  The number average molecular weight Mn of the thermoplastic resin B is preferably 300 to 5000, and more preferably 500 to 2000. When the number average molecular weight is within the above range, the polyester resin composition is excellent in moldability and mechanical strength. The number average molecular weight Mn of the thermoplastic resin B can be measured in terms of polystyrene by gel permeation chromatography (GPC) measurement.

  Such a thermoplastic resin B comprises a corresponding polyolefin wax (olefin polymer) and a corresponding vinyl compound having an aromatic hydrocarbon structure such as styrene, and a radical generator such as nitrile or peroxide. A modified polyolefin wax obtained by reacting in the presence of is preferable.

  Among them, the thermoplastic resin B is 1 to 900 parts by weight, more preferably 10 to 300 parts by weight of a vinyl compound having an aromatic hydrocarbon structure such as styrene with respect to 100 parts by weight of the corresponding polyolefin wax. It is particularly preferable that 20 to 200 parts by mass are introduced. By setting the content of the aromatic hydrocarbon structure to a certain level or more, compatibility with the polyester resin A can be easily improved, and thus the fluidity and releasability of the polyester resin composition at the time of molding can be sufficiently improved. As a result, it is easy to sufficiently increase the reflectance of the molded product. By setting the content of the aromatic hydrocarbon structure to a certain value or less, excessive generation of outgas due to heat during molding or mounting can be suppressed. As described above, the content of the aromatic hydrocarbon structure is the content ratio (% by mass) of the structural unit derived from the compound having an aromatic hydrocarbon structure with respect to 100 parts by mass of the structural unit derived from the polyolefin wax before modification. Say.

The content of the aromatic hydrocarbon structure of the thermoplastic resin B is determined by the ratio of the polyolefin wax at the time of preparation and the vinyl compound having an aromatic hydrocarbon structure, the nuclear magnetic resonance spectrum analyzer ( ¹³ C- NMR or ¹ H-NMR) can be specified by conventional methods such as structure identification, ratio of absorption intensity between phenyl structure carbon and other carbon, or ratio of absorption intensity between phenyl structure hydrogen and other carbon. Of course, infrared absorption spectrum analysis or the like can also be used in combination for structure identification.

For example, the content of the aromatic hydrocarbon structure of the thermoplastic resin B can be specified by ¹³ C-NMR measurement or ¹ H-NMR measurement.

^In the case of ¹ H-NMR measurement, an ECX400 type nuclear magnetic resonance apparatus manufactured by JEOL Ltd. is used and the solvent is deuterated orthodichlorobenzene. The sample concentration is 20 mg / 0.6 mL, the measurement temperature is 120 ° C., the observation nucleus is ¹ H (400 MHz), the sequence is a single pulse, the pulse width is 5.12 μsec (45 ° pulse), and the repetition time is 7.0. The number of seconds and integration is 500 times or more. The standard chemical shift is 0 ppm for tetramethylsilane hydrogen, but the same result can also be obtained by setting the peak derived from the residual hydrogen of deuterated orthodichlorobenzene to 7.10 ppm as the standard value for chemical shift. Can be obtained. A peak such as ¹ H derived from the functional group-containing compound can be assigned by a conventional method.

^In the case of ¹³ C-NMR measurement, an ECP500 type nuclear magnetic resonance apparatus manufactured by JEOL Ltd. is used as the measurement apparatus, and the solvent is ortho-dichlorobenzene / heavy benzene (80/20 vol%) mixed solvent. Also, the measurement temperature is 120 ° C, the observation nucleus is ¹³ C (125 MHz), single pulse proton decoupling, 45 ° pulse, repetition time is 5.5 seconds, integration number is 10,000 times or more, 27.50 ppm of chemical shift Use the reference value. Assignment of various signals is performed based on a conventional method, and quantification can be performed based on an integrated value of signal intensity.

  Examples of the vinyl compound having an aromatic hydrocarbon structure include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene and the like. Of these, styrene is preferred.

  Examples of polyolefin waxes include ethylene homopolymers and ethylene, and α-olefins having 3 or more carbon atoms such as propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-decene, and the like. And polyethylene wax, polypropylene wax, poly-4-methyl-1-pentene wax and the like selected from the group consisting of these copolymers. Among these, a polyethylene-based wax containing ethylene as a main component is preferable.

  The number average molecular weight Mn, density, and melting point of the polyolefin wax may be the same as the number average molecular weight Mn, density, and melting point of the unmodified polyolefin wax as the thermoplastic resin C described later.

  The polyolefin wax can be obtained, for example, by polymerizing a corresponding olefin at a low pressure or an intermediate pressure. Examples of the polymerization catalyst used for the polymerization include JP-A-57-63310, JP-A-58-83006, JP-A-3-706, JP-A-3476793, JP-A-4-218508, Magnesium-supported titanium catalysts described in JP 2003-105022 A, etc., WO 01/53369, WO 01/27124, JP 3-19396 A, or JP 2-41303 A. A transition metal-containing olefin polymerization catalyst having a metallocene catalyst described in the gazette or the like as a representative example is preferably used. Further, the corresponding olefin polymer such as polyethylene or polypropylene can be obtained by thermal decomposition or radical decomposition by a conventional method.

  As a method of introducing an aromatic structure into a polyolefin wax, a method of reacting a polyolefin wax with a vinyl compound having an aromatic hydrocarbon structure in the presence of a radical generator such as nitrile or peroxide described above. In addition, a method of thermally decomposing or radically decomposing these components in the presence of the olefin polymer and a polymer of an aromatic vinyl compound such as polystyrene can be used. Thermal decomposition reaction and radical decomposition reaction are expected to be accompanied by recombination reaction, although decomposition reaction is dominant. For this reason, if such a method is used, it is also possible to introduce an aromatic structure into the polyolefin skeleton.

  Content of the thermoplastic resin B in the polyester resin composition of this invention is 0.1-10 mass with respect to the sum total of the polyester resin A, the thermoplastic resin B, the thermoplastic resin C, the white pigment D, and the inorganic filler E. % Is preferred. When the content of the thermoplastic resin B is within the above range, it is easier to improve the fluidity and releasability during molding. The content of the thermoplastic resin B is more preferably 0.1 to 5% by mass with respect to the total of the polyester resin A, the thermoplastic resin B, the thermoplastic resin C, the white pigment D, and the inorganic filler E, More preferably, it is 0.1-3 mass%.

1-3. Thermoplastic resin C
Thermoplastic resin C has a polyolefin skeleton, the ratio intrinsic viscosity [eta _B] of the thermoplastic resin B having an intrinsic viscosity measured at 135 ° C. in decalin _{[η C] [η C]} / [η B] is 1 It is a thermoplastic resin that is super 25 or less. If the intrinsic viscosity ratio [η _C ] / [η _B ] is more than 1, bleeding out of the thermoplastic resin C from the polyester resin composition can be easily suppressed, and a decrease in reflectance can also be suppressed. When the intrinsic viscosity ratio [η _C ] / [η _B ] is 25 or less, the melt viscosity does not become too high, and the moldability is hardly impaired. The intrinsic viscosity ratio [η _C ] / [η _B ] is preferably 1 to 10, and more preferably 2 to 5. The intrinsic viscosity [η _C ] of the thermoplastic resin _C can be measured by the same method as the intrinsic viscosity [η _B ] of the thermoplastic resin B.

  The melt viscosity of the thermoplastic resin C at 140 ° C. is preferably 500 to 20000 mPa · s, and more preferably 500 to 10000 mPa · s. The viscosity can be measured by the same method as described above.

  More preferably, the thermoplastic resin C further satisfies the following (i) to (iv).

(I) The density of the thermoplastic resin C is preferably 900 to 985 kg / m ³ . When the density is within the above range, the moldability of the polyester resin composition becomes good. The density of the thermoplastic resin C is more preferably 950~980kg / ^{m 3,} more preferably less than 950 super 980 kg / ^{m 3.} The density of the thermoplastic resin C can be measured by a density gradient tube method according to JIS K7112. The density of the thermoplastic resin C can be adjusted by the composition of the olefin monomer during polymerization (during the synthesis of the thermoplastic resin C), the polymerization temperature during polymerization, and the hydrogen concentration.

  (Ii) The melting point of the thermoplastic resin C is preferably 65 to 165 ° C. If the melting point is below a certain level, the moldability of the polyester resin composition is hardly impaired, and if it is above a certain level, bleeding out of the thermoplastic resin C from the polyester resin composition can be suppressed. The melting point of the thermoplastic resin C is more preferably 80 to 160 ° C, and further preferably 110 to 150 ° C. The melting point can be measured in the same manner as the method for measuring the melting point of the polyester resin A. The melting point can be adjusted by the composition of the olefin monomer at the time of polymerization. For example, in the case of a copolymer of ethylene and α-olefin, the melting point tends to be lowered when the content of α-olefin is increased. Moreover, it can also adjust with a catalyst seed | species, superposition | polymerization temperature, etc.

  (Iii) The number average molecular weight Mn of the thermoplastic resin C is preferably 400 to 10,000. When the number average molecular weight is within the above range, the polyester resin composition is excellent in moldability and mechanical strength. The number average molecular weight Mn of the thermoplastic resin C is more preferably 900 to 9000, and further preferably 2000 to 9000. The number average molecular weight Mn of the thermoplastic resin C can be measured in terms of polystyrene by gel permeation chromatography (GPC) measurement. The number average molecular weight (Mn) and the intrinsic viscosity [η] can be adjusted by the polymerization temperature and the hydrogen concentration during the polymerization. For example, when the polymerization temperature at the time of polymerization is increased or the hydrogen concentration is increased, the number average molecular weight (Mn) and the intrinsic viscosity tend to be lowered.

  (Iv) The ratio Mw / Mn of the weight average molecular weight Mw and the number average molecular weight Mn of the thermoplastic resin C is preferably 1.5 to 5.5. When Mw / Mn is included in the above range, the appearance, heat resistance, and mechanical strength are excellent because there are few low molecular weight components that cause deterioration in physical properties. The Mw / Mn of the thermoplastic resin C is more preferably 1.5 to 5.0. Mw / Mn of the thermoplastic resin C can be determined in terms of polystyrene by gel permeation chromatography (GPC) measurement. Mw / Mn can be adjusted by the catalyst type, polymerization temperature, and the like during polymerization. In general, a Ziegler-Natta catalyst or a metallocene catalyst is used for the polymerization, but a metallocene catalyst is preferably used in order to obtain a suitable range of Mw / Mn.

  Among these, the number average molecular weight Mn of the thermoplastic resin C is larger than the number average molecular weight Mn of the thermoplastic resin B; the melting point of the thermoplastic resin C is preferably higher than the melting point of the thermoplastic resin B. This is because such a thermoplastic resin C is less likely to be decomposed and volatilized by heat during molding.

  Such a thermoplastic resin C is preferably an unmodified polyolefin wax, that is, a polyolefin wax having no functional group structure. The functional group structure refers to a functional group containing a hetero atom (such as an ester group, a carboxylic acid group, an ether group, an aldehyde group, or a ketone group) or the above-described aromatic hydrocarbon structure (such as styrene). That is, the acid value of the thermoplastic resin C is less than 1 mg KOH mg / g (preferably 0 mg KOH mg / g), and the content of the aromatic hydrocarbon structure is 1% by mass or less (preferably 0% by mass). preferable. The acid value of the thermoplastic resin C refers to the number of mg of potassium hydroxide required for neutralization per 1 g of the sample, and is measured according to JIS K5902.

  As the unmodified polyolefin wax, the same polyolefin wax (before modification) for obtaining the thermoplastic resin B can be used. Among these, when the thermoplastic resin B is a polyethylene wax, the thermoplastic resin C is preferably an unmodified polyethylene wax having good compatibility with the thermoplastic resin C.

  Content of the thermoplastic resin C in the polyester resin composition of this invention is 0.1-10 mass with respect to the sum total of the polyester resin A, the thermoplastic resin B, the thermoplastic resin C, the white pigment D, and the inorganic filler E. % Is preferred. When the content of the thermoplastic resin C is within the above range, generation of outgas due to heat during molding or mounting can be more easily suppressed. The content of the thermoplastic resin C is more preferably 0.1 to 5% by mass with respect to the total of the polyester resin A, the thermoplastic resin B, the thermoplastic resin C, the white pigment D, and the inorganic filler E, More preferably, it is 0.1-3 mass%.

  The mass ratio B / C of the thermoplastic resin B and the thermoplastic resin C is 0.01 to 1.0. When the content mass ratio B / C is 0.01 or more, the content of the thermoplastic resin B is moderately large, so that it is easier to improve fluidity and releasability while suppressing generation of outgas. When the content mass ratio B / C is 1.0 or less, the content of the thermoplastic resin C is moderately large, so that outgassing can be more easily suppressed without impairing fluidity and releasability. The mass ratio B / C of the thermoplastic resin B and the thermoplastic resin C is preferably 0.05 to 0.7, and more preferably 0.1 to 0.5.

  The total content of the thermoplastic resin B and the thermoplastic resin C is 0.1 to 15% by mass with respect to the total of the polyester resin A, the thermoplastic resin B, the thermoplastic resin C, the white pigment D, and the inorganic filler E. is there. When the total content of the thermoplastic resin B and the thermoplastic resin C is 0.1% by mass or more, it is easier to improve the fluidity and releasability of the polyester resin composition at the time of molding, and it is 15% by mass or less. The properties of the polyester resin A are not easily impaired. The total content of the thermoplastic resin B and the thermoplastic resin C is 0.3 to 5% by mass with respect to the total of the polyester resin A, the thermoplastic resin B, the thermoplastic resin C, the white pigment D, and the inorganic filler E. It is preferable that it is 0.5 to 3% by mass.

1-4. White pigment D
The white pigment D can whiten the polyester resin composition and further improve the light reflection function. Specifically, the white pigment D preferably has a refractive index of 2.0 or more. The upper limit of the refractive index of the white pigment D is, for example, 4.0. Examples of the white pigment D include titanium oxide, zinc oxide, zinc sulfide, lead white, zinc sulfate, barium sulfate, calcium carbonate, and alumina oxide. These white pigments D may be used individually by 1 type, and may use 2 or more types together.

  From the viewpoint of further improving the reflectance and concealability of the polyester resin composition, the white pigment D is preferably titanium oxide. The titanium oxide is preferably a rutile type.

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

  From the viewpoint of making the reflectance of the polyester resin composition more uniform, the white pigment D preferably has a small aspect ratio, that is, a shape close to a sphere.

  The average particle diameter of the white pigment D is preferably 0.1 to 0.5 μm, and more preferably 0.15 to 0.3 μm. The average particle size of the white pigment D is obtained by plotting the particle amount (%) in each particle size interval of primary particles using an image diffractometer (Luzex IIIU) based on a transmission electron micrograph. Then, a cumulative distribution curve is obtained from the obtained distribution curve, and the value when the cumulative degree in this cumulative distribution curve is 50% can be obtained.

  The content of the white pigment D in the polyester resin composition of the present invention is 5 to 5 when the total of the polyester resin A, the thermoplastic resin B, the thermoplastic resin C, the white pigment D, and the inorganic filler E is 100% by mass. 50% by mass. When the content of the white pigment D is 5% by mass or more, the whiteness of the polyester resin composition is more likely to be increased, and the reflectance is likely to be further increased. On the other hand, when the content of the white pigment D is 50% by mass or less, the fluidity (moldability) at the time of melt molding is hardly impaired. The content of the white pigment D is more preferably 10 to 50% by mass, further preferably 10 to 40% by mass, and particularly preferably 10 to 30% by mass.

1-5. Inorganic filler E
The inorganic filler E is an inorganic compound filler having a spherical, fibrous, or plate-like shape. From the viewpoint of further enhancing the strength and toughness of the polyester resin composition, the inorganic filler E is preferably fibrous.

  Examples of the fibrous inorganic filler E 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 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. 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 E is usually 5 mm or less. By making the fibrous inorganic filler E difficult to break and finely dispersing the inorganic filler E in the resin, the excess stress that the resin receives during molding is reduced and the polyester resin A is further thermally decomposed. From the viewpoint of making it difficult, the average fiber length (l) is preferably 300 μm or less, more preferably 100 μm or less, and even more preferably 50 μm or less. Moreover, since the inorganic filler E is finely dispersed in the resin by setting the average fiber length (l) in the above range, the surface smoothness of the polyester resin composition is more likely to be increased. Although there is no restriction | limiting in particular in the lower limit of average fiber length (l), From a viewpoint of raising the intensity | strength of a polyester resin composition more, it is preferable that it is 2 micrometers, and it is more preferable that it is 8 micrometers.

  From the viewpoint of facilitating fine dispersion of the fibrous inorganic filler E and enhancing the surface smoothness of the molded product, the average fiber diameter (d) of the fibrous inorganic filler E is 0.05 to 30 μm. It is preferable that it is 2-6 micrometers. When the average fiber diameter (d) is not more than a certain value, the fibrous inorganic filler E is not easily broken at the time of molding or the like, and the strength of the polyester resin composition is further increased. Further, when the average fiber diameter (d) is not less than a certain value, the fibrous inorganic filler E can be molded in a finely dispersed state, so that the surface smoothness of the polyester resin composition is further increased and the reflectance is further increased. Rise.

The average fiber length (l) and the average fiber diameter (d) of the fibrous inorganic filler E in the polyester resin composition (for example, a compound such as pellets) can be measured by the following method.
1) A polyester resin composition is dissolved in a hexafluoroisopropanol / chloroform solution (0.1 / 0.9% by volume), and then a filtrate obtained by filtration is collected.
2) Arbitrary 100 fibrous inorganic fillers E of the obtained filtrate are observed with a scanning electron microscope (SEM) (magnification: 50 times), and each fiber length and fiber diameter are measured. The average value of the fiber length can be the average fiber length (l), and the average value of the fiber diameter can be 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 polyester resin composition.

  Content of the inorganic filler E in the polyester resin composition of this invention is 5-50 mass% with respect to the sum total of the polyester resin A, the thermoplastic resin B, the thermoplastic resin C, the white pigment D, and the inorganic filler E. Preferably there is. When the content of the inorganic filler E is 5% by mass or more, the heat resistance and strength of the polyester resin composition can be easily increased, and when it is 50% by mass or less, the moldability of the polyester resin composition and the surface smoothness of the molded product are improved. It is hard to lose the nature. The content of the inorganic filler E is more preferably 10 to 40% by mass with respect to the total of the polyester resin A, the thermoplastic resin B, the thermoplastic resin C, the white pigment D, and the inorganic filler E. More preferably, it is 25 mass%.

  The total content of white pigment D and inorganic filler E relative to the total of polyester resin A, thermoplastic resin B, thermoplastic resin C, white pigment D, and inorganic filler E determines the mechanical strength and whiteness of the molded product. From the viewpoint of further enhancement, it can be set to 40 to 60% by mass, for example.

1-6. Other ingredients F
The polyester resin composition for a reflector of the present invention is within a range that does not impair the effects of the present invention, and other components other than the above-described components A to E, such as antioxidants (phenols, amines), depending on the application. , Sulfurs, phosphorus, etc.), light stabilizers (benzotriazoles, triazines, benzophenones, hindered amines, ogizanides, etc.), heat stabilizers (lactone compounds, vitamin E, hydroquinones, copper halides, iodine) Compound), other polymers (olefins such as polyolefins, ethylene / propylene copolymers, ethylene / 1-butene copolymers, olefin copolymers such as propylene / 1-butene copolymers, polystyrene , Polyamide, polycarbonate, polyacetal, polysulfone, polyphenylene oxide, fluororesin, silico Resins, LCP, etc.), flame retardants (bromine, chlorine, phosphorus, antimony, inorganic, etc.), fluorescent brighteners, plasticizers, thickeners, antistatic agents, release agents, pigments, crystal nuclei It may further contain additives such as 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. The antioxidant is preferably phenols (including hindered phenols) or phosphorus.

  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 are included. Examples of commercially available products include IRGANOX 1010, 1076, 1726 (above, manufactured by BASF Japan).

Phosphorus is a compound (phosphite compound) having a P (OR) ₃ structure. R is an alkyl group, an alkylene group, an aryl group, an arylene group, or the like, and three Rs may be the same or different, and two Rs may form a ring structure. Examples of phosphorus include triphenyl phosphite, diphenyl decyl phosphite, phenyl diisodecyl phosphite, tri (nonylphenyl) phosphite, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite and the like are included. When an antioxidant containing phosphorus is contained in the polyester resin composition, the decomposition reaction of the polyester resin A is suppressed under a high-temperature atmosphere (particularly, conditions exceeding 250 ° C. as in the reflow process). As a result, discoloration or the like of the reflecting material obtained by molding the polyester resin composition is suppressed.

  The content of the antioxidant is preferably 2.5% by mass or less based on the total of the polyester resin A, the thermoplastic resin B, the thermoplastic resin C, the white pigment D, and the inorganic filler E, and is 1% by mass. The following is more preferable. When the content of the antioxidant is within the above range, the weather resistance and heat resistance of the molded product can be sufficiently enhanced.

2. Method for Producing Polyester Resin Composition for Reflective Material The polyester resin composition of the present invention is prepared by a known method, for example, a method of mixing with a Henschel mixer, a V blender, a ribbon blender or a tumbler blender, or a single screw extruder after the above mixing. It can be produced by a method of melt-kneading with a multi-screw extruder, a kneader or a Banbury mixer, and granulating or pulverizing after the melt-kneading.

  The 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 the melt kneading can be 255 ° C, preferably 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 product 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 reflectance of the light having a wavelength of 450 nm of the thus produced reflective material of the present invention is preferably 90% or more, and more preferably 94% or more. The reflectance can be measured using CM3500d manufactured by Konica Minolta. The thickness of the molded product at the time of measurement can be 0.5 mm.

  It is preferable that the reflective material of the present invention has little decrease in reflectance even when it receives heat or light. Specifically, the reflectance of light having a wavelength of 450 nm measured after heating the reflective material of the present invention at 150 ° C. for 500 hours can be, for example, 90% or more. The thickness of the molded product at the time of measurement can be 0.5 mm.

  The reflective material of the present invention can be a casing, a housing, or the like having at least a light reflecting surface. The surface that reflects light may be a flat surface, a curved surface, or a spherical surface. For example, the reflecting material may be a molded product having a light reflecting surface in a box shape or box shape, funnel shape, bowl shape, parabolic shape, columnar shape, conical shape, honeycomb shape, or the like.

  The reflective material of the present invention is used as a reflective material for various light sources such as an organic EL and a 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.

  An LED package provided with the reflective material of the present invention includes, for example, a housing part formed on a substrate and having a space for mounting an LED, the LED mounted in the space, and a sealing member for sealing the LED Can be included. Such an LED package includes: 1) a step of forming a reflective material on a substrate to obtain a housing portion; 2) a step of disposing an LED in the housing portion and electrically connecting the LED and the substrate; 3) It can be manufactured through a process of sealing the LED with a sealant. In the sealing step, heating is performed at a temperature of 100 to 200 ° C. in order to thermally cure the sealant. Furthermore, in the reflow soldering process when mounting the LED package on the printed circuit board, the LED package is exposed to a high temperature of 250 ° C. or higher.

  Since the polyester resin composition for a reflector according to the present invention contains the thermoplastic resin C together with the thermoplastic resin B, it is possible to suppress the generation of outgas during molding without impairing the fluidity and mold release during molding. Thereby, mold contamination can be suppressed. Furthermore, even if it is exposed to high-temperature heat in the mounting process of the LED package including the reflective material, the reflective material obtained from the polyester resin composition for reflective material of the present invention contains the thermoplastic resin C together with the thermoplastic resin B. Even if it is exposed to high-temperature heat in the mounting process, it is possible to suppress the generation of outgas and to thereby suppress adhesion failure and the like.

  The reflective material of the present invention can be used for various applications, for example, as a reflective material for various electric and electronic parts, indoor lighting, outdoor lighting, automobile lighting, and the like.

  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. Material Preparation <Polyester Resin A>
Polyester resin A-1: Polyester resin synthesized by the following method

(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, 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. . 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 obtained polyester resin A-1 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 mass% mixed solvent of phenol and tetrachloroethane to obtain a sample solution. The flow down time of the obtained sample solution was measured under the condition of 25 ° C. ± 0.05 ° C. using an Ubbelohde viscometer, and the intrinsic viscosity [η] was calculated by applying the following equation.
[Η] = ηSP / [C (1 + kηSP)]
[Η]: Intrinsic viscosity (dl / g)
ηSP: specific viscosity C: sample concentration (g / dl)
t: Number of seconds that the sample solution flows (seconds)
t0: The number of seconds during which the solvent flows (seconds)
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)
ηSP = (t−t0) / t0

(Melting point (Tm))
Melting | fusing point (Tm) was measured based on JIS-K7121 with the differential scanning calorimeter (DSC). 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. The temperature at the peak top of the endothermic peak at the time of temperature rise was defined as “melting point”.

<Thermoplastic resin B>
The following thermoplastic resins B-1 and B-2 were obtained by reacting an ethylene polymer wax obtained with a known solid titanium catalyst component and styrene in the presence of a known radical generator.
B-1:
Intrinsic viscosity [η _B ] measured at 135 ° C. in decalin: 0.03 dl / g
Melt viscosity at 140 ° C .: 40 mPa · s
Weight average molecular weight Mw: 930
Molecular weight distribution Mw / Mn: 1.8
Melting point: 107 ° C
Styrene content: 20% by mass
B-2:
Intrinsic viscosity [η _B ] measured at 135 ° C. in decalin: 0.11 dl / g
Melt viscosity at 140 ° C .: 1100 mPa · s
Melting point: 104 ° C
Styrene content: 60% by mass

<Thermoplastic resin C>
C-1: High wax 800P: Unmodified polyethylene wax (Mitsui Chemicals, weight average molecular weight: 12700, molecular weight distribution Mw / Mn: 3.1, melting point: 127 ° C., melt viscosity (140 ° C.): 8000 mPa · s, Intrinsic viscosity [η _C ]: 0.40 dl / g)

  The intrinsic viscosity, melt viscosity, weight average molecular weight and molecular weight distribution of the thermoplastic resins B and C were measured by the following methods, respectively.

(Intrinsic viscosity)
About 20 mg of sample was dissolved in 15 ml of decalin to obtain a solution. The specific viscosity ηsp of the obtained solution was measured in an oil bath at 135 ° C. The solution was further diluted with 5 ml of decalin solvent, and the specific viscosity ηsp was measured in the same manner. This dilution operation was further repeated twice, and the value of ηsp / C when the concentration (C) was extrapolated to 0 was determined as the intrinsic viscosity.
[Η] = lim (ηsp / C) (C → 0 [molecular weight])

(Melt viscosity at 140 ° C)
Measurements were made at 140 ° C. using a Brookfield viscometer.

(Weight average molecular weight (Mw), molecular weight distribution (Mw / Mn))
The weight average molecular weight Mw was obtained from GPC measurement. The measurement was performed under the following conditions. And the weight average molecular weight Mw and the number average molecular weight Mn were calculated | required from the calibration curve using a commercially available monodisperse standard polystyrene, and Mw / Mn was computed.
Apparatus: Gel permeation chromatograph Alliance GPC2000 (manufactured by Waters)
Solvent: o-dichlorobenzene Column: TSKgel GMH6-HT × 2, TSKgel GMH6-HTL column × 2 (both manufactured by Tosoh Corporation)
Flow rate: 1.0 ml / min Sample: 0.15 mg / mL o-dichlorobenzene solution Temperature: 140 ° C.

  The melting points of the thermoplastic resins B and C were the same as the method for measuring the melting point of the polyester resin A. Moreover, the styrene content rate was computed from the styrene compounding quantity at the time of a synthesis | combination.

<White pigment D>
Titanium oxide: powder, average particle size 0.21 μm

  The average particle diameter of titanium oxide was determined by image analysis using an image diffraction apparatus (Luzex IIIU) based on a transmission electron micrograph.

<Inorganic filler E>
Glass fiber: average fiber length (l) 3 mm, average fiber diameter 6.5 μm (ECS03T-171DE / P9W manufactured by Nippon Electric Glass Co., Ltd., silane compound treated product)

<Other components F>
Irganox 1010 (antioxidant): tetrakis [3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionic acid] pentaerythritol (manufactured by BASF)
PEP-36 (antioxidant): bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol phosphite (manufactured by ADEKA Corporation, molecular weight 633, melting point 234-240 ° C.)

2. Preparation and evaluation of polyester resin composition for reflector [Example 1]
52.13 parts by mass of the polyester resin A-1 synthesized as the polyester resin A, 0.4 parts by mass of 1160H as the thermoplastic resin B, 1.6 parts by mass of 800P as the thermoplastic resin C, white pigment D 35 parts by mass of the titanium oxide, 10 parts by mass of the glass fiber as the inorganic filler E, 0.16 parts by mass of the Irganox 1010 as an antioxidant, and 0.08 parts by mass of the PEP-36, a tumbler blender And mixed. 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. The extrudate was cooled in a water tank, and then the strands were drawn with a pelletizer and cut to obtain a pellet-shaped polyester resin composition.

[Example 2 and Comparative Examples 1 to 4]
A pellet-shaped polyester resin composition was obtained in the same manner as in Example 1 except that the composition was changed to the composition shown in Table 1.

  Reflective properties (various reflectivities), moldability (flow length), bending properties (toughness, flexural strength, flexural modulus, deflection) of the polyester resin compositions obtained in Examples 1-2 and Comparative Examples 1-4 , Outgas and releasability were evaluated by the following methods, respectively.

<Reflection characteristics>
(Initial reflectance)
The obtained polyester resin composition was injection-molded under the following molding conditions using the following molding machine 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: SE50DU, manufactured by Sumitomo Heavy Industries, Ltd.
Cylinder temperature: melting point (Tm) + 10 ° C.
Mold temperature: 150 ° C
The reflectance of a wavelength region of 360 nm to 740 nm was determined for the obtained test piece using Minolta CM3500d. The reflectance at a wavelength of 450 nm was used as a representative value to be the initial reflectance.

(Reflectance after heating)
The test piece whose initial reflectance was measured was left in an oven at 150 ° C. for 500 hours. Then, the reflectance of the obtained sample piece was measured by the same method as the initial reflectance, and was defined as the reflectance after heating.

<Moldability>
(Flow length)
The obtained polyester resin composition was 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 in the mold was measured.
Injection molding machine: Sodick Plustec, Tupar TR40S3A
Injection set pressure: 2000 kg / cm ²
Cylinder setting temperature: Melting point (Tm) + 10 ° C
Mold temperature: 30 ℃

<Bending characteristics>
The obtained polyester resin composition was molded under the following molding conditions using the following molding machine to obtain a test piece. The test piece was 64 mm long, 6 mm wide, and 0.8 mm thick.
Molding machine: Injection molding machine (Sodick Plustech, Tupar TR40S3A)
Cylinder temperature: 300 ° C
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 at a temperature of 23 ° C. and a humidity of 50% Rh in a bending test machine: AB5 manufactured by NTSCO, span 26 mm, bending speed 5 mm / min. The strength, elastic modulus, toughness, and deflection at this time were It was measured.

<Outgas characteristics>
The amount of gas generated when the obtained polyester resin composition was heated under the following conditions using the following apparatus was measured by gas chromatography.
Heating condition: 295 ° C. × 3 minutes Heat desorption apparatus: GERSA TDSA / TDS3 / CIS4
Gas chromatography apparatus: HP6890-HP5973 manufactured by Agilent Technologies
Gas desorption temperature: 300 ° C. × 2 minutes Trap temperature: −150 ° C.
Column flow rate: 1.4 mL / min

<Releasability>
The obtained polyester resin composition was injection-molded with an arbitrary shape test piece having a sprue bushing of 70 mm in length, 7 mm in width and 2 mm under the following molding conditions using the following molding machine. A sprue bush refers to a cylindrical body having a taper. That is, a sprue bush having a length of 70 mm, a width of 7 mm, and a 2 mm means that, of the two surfaces facing the length direction in the cylindrical body, the diameter of the smaller surface is 2 mm, the diameter of the larger surface is 7 mm, A length in the length direction is 70 mm.
Molding machine: SE50DU manufactured by Sumitomo Heavy Industries, Ltd.
Cylinder temperature: Melting point (Tm) + 10 ° C
Mold temperature: 150 ° C
The cooling time when the sprue bushing was released from the mold after 5 samples during molding was defined as the release time. Specifically, 1) A test piece having the sprue bush was injection molded with a cooling time of 5 seconds. 2) When the sprue bush was released from the mold within the above cooling time for 5 consecutive samples, the cooling time was 5 seconds. 3) When the sprue bushing was not released within the cooling time, the cooling time was extended, and the time when the sprue bushing was released for 5 consecutive samples was taken as the cooling time.
When the release time was 5 seconds or less, it was judged that the release property was good.

Table 1 shows the evaluation results of Examples 1-2 and Comparative Examples 1-4.

  As shown in Table 1, the polyester resin compositions of Examples 1 and 2 in which the thermoplastic resin B and the thermoplastic resin C are combined have good moldability and releasability while generating outgas. It can be seen that it can be reduced.

  On the other hand, it can be seen that the polyester resin compositions of Comparative Examples 1 and 2 that do not contain the thermoplastic resin C have good moldability and mold release properties, but generate a lot of outgas. On the other hand, it can be seen that the polyester resin composition of Comparative Example 3 that does not contain the thermoplastic resin B has a slightly low moldability, although the outgassing is small. It can be seen that the polyester resin composition of Comparative Example 4 that does not contain both the thermoplastic resin B and the thermoplastic resin C has low outgassing, but has low moldability and releasability.

  The polyester resin composition for a reflector according to the present invention provides a polyester resin composition for a reflector that can suppress the occurrence of outgas during molding or mounting while improving fluidity and mold release during molding. it can.

Claims (11)

30 to 80% by mass of polyester resin A having a melting point Tm or glass transition temperature Tg of 250 ° C. or higher measured by a differential scanning calorimeter (DSC),
A thermoplastic resin B having a polyolefin skeleton and an aromatic hydrocarbon structure and having an intrinsic viscosity [η _B ] measured at 135 ° C. in decalin of 0.01 to 1.0 dl / g is 0.01 to 10 Mass%,
The ratio [η _C ] / [η _B ] of the intrinsic viscosity [η _C ] measured at 135 ° C. in decalin to the intrinsic viscosity [η _B ] of the thermoplastic resin B is more than 1 and 25 or less. 0.01 to 10% by mass of the thermoplastic resin C,
5 to 50% by mass of white pigment D,
5 to 50% by mass of inorganic filler E (however, the total of the polyester resin A, the thermoplastic resin B, the thermoplastic resin C, the white pigment D, and the inorganic filler E is 100% by mass) A polyester resin composition for reflectors. The polyester resin composition for a reflector according to claim 1, wherein the thermoplastic resin C is a polyolefin wax having no functional group structural unit and satisfies the following (i) to (iv).
(I) Density is 900 to 985 kg / m ³
(Ii) Melting point is 65 to 165 ° C
(Iii) Number average molecular weight Mn is 400 to 10,000
(Iv) The ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn is 1.5 to 5.5.   The polyester resin composition for a reflector according to claim 2, wherein the thermoplastic resin C is a polyethylene wax having no functional group structural unit.   The polyester resin composition for a reflector according to any one of claims 1 to 3, wherein a mass ratio B / C of the thermoplastic resin B and the thermoplastic resin C is 0.01 to 1.0. .   The total content of the thermoplastic resin B and the thermoplastic resin C is 0 with respect to the total of the polyester resin A, the thermoplastic resin B, the thermoplastic resin C, the white pigment D, and the inorganic filler E. The polyester resin composition for a reflector according to claim 4, wherein the content is from 1 to 15% by mass. The polyester resin A is
A dicarboxylic acid component unit comprising 30 to 100 mol% of a component unit derived from terephthalic acid and 0 to 70 mol% of a component unit derived from an aromatic dicarboxylic acid other than terephthalic acid;
A dialcohol component unit comprising 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 polyester resin composition for reflectors as described in any one of Claims 1-5 containing this.   The polyester resin composition for a reflector according to claim 6, wherein the component unit derived from the alicyclic dialcohol has a cyclohexane skeleton.   The reflection according to claim 6 or 7, wherein the dialcohol component unit includes 30 to 100 mol% of a component unit derived from cyclohexanedimethanol and 0 to 70 mol% of a component unit derived from the aliphatic dialcohol. Polyester resin composition for materials.   The said white pigment D is a polyester resin composition for reflectors as described in any one of Claims 1-8 which is a titanium oxide.   The reflector obtained by shape | molding the polyester resin composition for reflectors as described in any one of Claims 1-9.   The reflective material according to claim 10 which is a reflective material for a light emitting diode element.