JP2018172511A - Polyester resin composition for reflector, and reflector using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyester resin composition for reflector capable of obtaining a reflector which hardly lowers reflectance even when exposed to high temperature and irradiated with light for a long time and has high strength.SOLUTION: A polyester resin for reflector contains a crystalline polyester resin (A), an amorphous polyester resin (B), an inorganic filler (C) and a white pigment (D). A content ratio of the crystalline polyester resin (A) and the amorphous polyester resin (B) is 1/99 to 49/51. The amorphous polyester resin (B) contains a dicarboxylic acid component unit (b1) containing 60-100 mol% of a terephthalic acid-derived component unit, and a dialcohol component unit (b2) containing a 1,4-cyclohexane dimethanol-derived component unit and a 2,2,4,4-tetramethyl-cyclobutanediol-derived component unit, or a 1,4-cyclohexane dimethanol-derived component unit and an aliphatic dialcohol-derived component unit.SELECTED DRAWING: None

Description

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

  Light sources such as light emitting diodes (hereinafter abbreviated as LEDs) and organic ELs are widely used as illumination and display backlights by taking advantage of low power and long life. And in order to utilize the light from these light sources efficiently, the reflective material which reflects the light from a light source is utilized in various situations. The reflective material is required to exhibit a high reflectance under any use environment.

  In recent years, due to cost reduction requirements, it has been required to reduce the number of light sources (LED packages) mounted on final products such as televisions and displays. Therefore, it is required to improve the reflectivity of the reflecting material and use the light from the light source more efficiently.

  As a resin composition for producing such a reflector, a resin composition containing a semi-aromatic polyester resin, glass fiber, and a white pigment has been proposed (for example, Patent Document 1). In the resin composition, a reflective material having a relatively high reflectance can be obtained.

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

US Patent Application Publication No. 2014/0191263

  However, when the reflector made of the resin composition of Patent Document 1 described above is heated for a long period of time or irradiated with light, it is likely to be colored and the reflectance is likely to decrease. Moreover, the reflective material which consists of the said resin composition may not have sufficient mechanical strength.

  The present invention has been made in view of the above circumstances. That is, an object of the present invention is to provide a polyester resin composition for a reflector, which is less susceptible to a decrease in reflectance even when exposed to high temperatures or irradiated with light for a long time, and from which a reflector having high strength can be obtained. .

That is, the first of the present invention relates to the following polyester resin composition for reflectors.
[1] 30-80% by mass in total of a crystalline polyester resin (A) having a melting point or glass transition temperature of 250 ° C. or more and an amorphous polyester resin (B) in which no melting point is observed, and an inorganic filler (C ) 1-50 mass%, white pigment (D) 5-50 mass% (the crystalline polyester resin (A), the amorphous polyester resin (B), the inorganic filler (C), and the white The ratio of the mass content of the crystalline polyester resin (A) and the amorphous polyester resin (B) is 1/99 to 49/51. The amorphous polyester resin (B) includes a dicarboxylic acid component unit (b1) derived from a dicarboxylic acid and a dialcohol component unit (b2) derived from a dialcohol, and the dicarboxylic acid component unit b1) contains 60 to 100 mol% of component units derived from terephthalic acid, and the dialcohol component unit (b2) is 1 to 99 mol of component units derived from (b2-1) 1,4-cyclohexanedimethanol. % And component units derived from 2,2,4,4-tetramethyl-cyclobutanediol 99 to 1 mol%, or (b2-2) component units derived from 1,4-cyclohexanedimethanol 20 A polyester resin composition for a reflector, comprising: mol% or more and less than 40 mol%;

[2] The polyester resin composition for a reflector according to [1], wherein the component unit derived from the aliphatic dialcohol contained in the dialcohol component unit (b2) is a component unit derived from ethylene glycol.
[3] The crystalline polyester resin (A) includes a dicarboxylic acid component unit (a1) derived from a dicarboxylic acid and a dialcohol component unit (a2) derived from a dialcohol, and the dicarboxylic acid component unit (a1) ) Includes 30 to 100 mol% of component units derived from terephthalic acid and 0 to 70 mol% of component units derived from aromatic dicarboxylic acid other than terephthalic acid, and the dialcohol component unit (a2) is: The component unit derived from an alicyclic dialcohol having an alicyclic hydrocarbon skeleton having 4 to 20 carbon atoms and / or the component unit derived from an aliphatic dialcohol is described in [1] or [2] A polyester resin composition for reflectors.

[4] The dialcohol component unit (a2) is composed of 40 to 100 mol% of component units derived from 1,4-cyclohexanedimethanol and 0 to 60 mol% of component units derived from the aliphatic dialcohol. The polyester resin composition for reflectors according to [3].
[5] The polyester resin composition for a reflector according to any one of [1] to [4], wherein the white pigment (D) is titanium oxide.

2nd of this invention is related with the following reflective materials.
[6] A reflective material comprising a molded product of the polyester resin composition for reflective material according to any one of [1] to [5].
[7] The reflective material according to [6], which is a reflective material for a light emitting diode element.

  According to the polyester resin composition for a reflector of the present invention, it is possible to obtain a reflector having a high mechanical strength that is difficult to reduce the reflectance even when exposed to a high temperature or subjected to light irradiation for a long time. is there.

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

  As described above, it has been studied to obtain various reflectors by molding a resin composition containing a crystalline semi-aromatic polyester resin, an inorganic filler, and a white pigment. Crystalline semi-aromatic polyester resins have relatively high melting points and glass transition temperatures. Therefore, there is an advantage that the reflective material is excellent in heat resistance. However, the reflective material obtained from such a resin composition may not have sufficient mechanical strength, and the reflectance is likely to decrease due to heating or light irradiation. The reason is considered as follows. For example, the crystalline semi-aromatic polyester contained in the resin composition described in Patent Document 1 mainly includes a component unit derived from an aromatic dicarboxylic acid and a component unit derived from an alicyclic dialcohol having a cyclohexane ring. Included. And in the semi-aromatic polyester resin having such a structure, when the reflecting material is heated or the reflecting material is irradiated with light, the component unit derived from the alicyclic dialcohol easily adopts a conjugated structure, and the reflecting material Is considered to be colored.

On the other hand, the resin composition of the present invention comprises a crystalline polyester resin (A), an amorphous polyester resin (B) having a specific structure, an inorganic filler (C), and a white pigment (D). ,including. The amorphous polyester resin (B) whose structure is specified in the present invention partially includes a component unit that is difficult to adopt a conjugated structure by heating, light irradiation, or the like. Furthermore, in the resin composition of the present invention, the mass ratio of the crystalline polyester resin (A) to the amorphous polyester resin (B) is 1/99 to 49/51. That is, many amorphous polyester resins (B) containing the component unit which cannot take a conjugated structure are included. Therefore, the reflective material obtained from the resin composition is less likely to be colored. In general, it is considered that when the proportion of the amorphous polyester resin (B) increases, the crystallinity of the resin decreases, and the strength of the obtained reflector decreases. On the other hand, the crystalline polyester resin (A) and the non-crystalline polyester resin (B) having a specific structure are easily compatible since they have a similar structure (particularly a structure having a similar alicyclic skeleton). When the mass ratio is in the above range, the strength of the obtained reflecting material is difficult to decrease. Moreover, since the reflective material obtained from the said resin composition contains the above-mentioned range and an amorphous polyester resin (B), it also has the advantage that it is hard to produce heat shrink and a crack etc. do not produce easily.
Hereinafter, each component contained in the resin composition will be described.

1-1. Crystalline polyester resin (A)
The crystalline polyester resin (A) has a plurality of ester structures represented by-(C = O) -O- in the molecule, and has a melting point (Tm) or glass measured by a differential scanning calorimeter (DSC). The type of the resin is not particularly limited as long as it has a transition temperature (Tg) of 250 ° C. or higher and has crystallinity. The presence or absence of crystallinity can be specified by whether or not the heat of fusion of the crystal is observed by differential scanning calorimetry (DSC). The resin composition of the present invention may contain only one type of crystalline polyester resin (A), or may contain two or more types.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  Here, the intrinsic viscosity [η] of the crystalline polyester resin (A) is preferably 0.3 to 1.2 dl / g. When the intrinsic viscosity is in the above range, the fluidity during molding of the resin composition is increased. The intrinsic viscosity of the crystalline polyester resin (A) can be adjusted by the molecular weight of the crystalline polyester resin (A). Examples of the method for adjusting the molecular weight of the crystalline 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. included.

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

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

The above ηSP is obtained by the following equation.
ηSP = (t−t0) / t0
In the above formula, each variable represents the following.
t: Number of seconds that the sample solution flows (seconds)
t0: The number of seconds during which the solvent flows (seconds)

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

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

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

1-2. Amorphous polyester resin (B)
The amorphous polyester resin (B) has a plurality of ester structures represented by-(C = O) -O- in the molecule, and has a melting point (Tm) when measured with a differential scanning calorimeter (DSC). ) Is an amorphous resin that does not show. The presence or absence of the melting point (Tm) of the amorphous polyester resin (B) can be confirmed by a differential scanning calorimeter (DSC) according to JIS-K7121. A specific method can be the same as the method for confirming the melting point of the crystalline polyester resin (A).

  The amorphous polyester resin (B) includes a dicarboxylic acid component unit (b1) derived from a dicarboxylic acid and a dialcohol component unit (b2) derived from a dialcohol, and the dicarboxylic acid component unit (b1) 60-100 mol% of component units derived from terephthalic acid are included. On the other hand, the dialcohol component unit (b2) is derived from (b2-1) 1,99 mol% of component units derived from 1,4-cyclohexanedimethanol and 2,2,4,4-tetramethyl-cyclobutanediol. 99 to 1 mol% of component units, or (b2-2) 20 to 40 mol% of component units derived from 1,4-cyclohexanedimethanol and component units derived from aliphatic dialcohol More than 60 mol% and 80 mol% or less. The resin composition of the present invention may contain only one type of amorphous polyester resin (B), or may contain two or more types.

  From the viewpoint of further improving the heat resistance of the reflector obtained from the resin composition, the dicarboxylic acid component unit (b1) more preferably contains 70 to 100 mol% of a component unit derived from terephthalic acid, and 80 to 100 More preferably, it is contained in mol%. Moreover, the dicarboxylic acid component unit (b1) may contain 0 to 40 mol%, more preferably 0 to 30 mol% of a component unit derived from an aromatic dicarboxylic acid other than terephthalic acid. More preferably, it is contained in mol%.

  The component unit derived from terephthalic acid and the component unit derived from an aromatic dicarboxylic acid other than terephthalic acid are component units derived from terephthalic acid in the dicarboxylic acid component (a1) of the crystalline polyester resin (A). And a component unit derived from an aromatic dicarboxylic acid.

  The total of the component units derived from the terephthalic acid and the component units derived from an aromatic dicarboxylic acid other than terephthalic acid is preferably 100 mol%. However, depending on the desired properties, the dicarboxylic acid component unit (b1) is a component unit derived from a small amount of an aliphatic dicarboxylic acid or a component unit derived from a polyvalent carboxylic acid having three or more carboxylic acid groups in the molecule. May further be included. The 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 (b1) is preferably 10 mol% or less in total. The component unit derived from the aliphatic dicarboxylic acid and the component unit derived from the polyvalent carboxylic acid are component units derived from the aliphatic dicarboxylic acid in the dicarboxylic acid component (a1) of the crystalline polyester resin (A) described above. This is the same as the component derived from the polyvalent carboxylic acid.

  On the other hand, the dialcohol component unit (b2) is composed of 1 to 99 mol% of the component unit derived from (b2-1) 1,4-cyclohexanedimethanol and 2,2,4,4-tetramethyl as described above. -Component unit derived from cyclobutanediol 99 to 1 mol%, (b2-2) component unit derived from 1,4-cyclohexanedimethanol 20 mol% or more and less than 40 mol%, The component unit derived from alcohol may include more than 60 mol% and 80 mol% or less.

  When the dialcohol component unit (b2) includes a component unit derived from (b2-1) 1,4-cyclohexanedimethanol and a component unit derived from 2,2,4,4-tetramethyl-cyclobutanediol, reflection From the viewpoint of increasing the heat resistance of the material and reducing the water absorption, the dialcohol component unit (b2) more preferably contains 20 to 99 mol% of the component unit derived from 1,4-cyclohexanedimethanol. 40 to 99 mol% is more preferable.

  Here, isomers such as a cis / trans structure exist in 1,4-cyclohexanedimethanol, but from the viewpoint of further improving the heat resistance of the reflector obtained from the resin composition, it has a cyclic (trans) structure. It is preferable to contain more component units derived from 1,4-cyclohexanedimethanol. Therefore, the cis / trans ratio of the component unit derived from 1,4-cyclohexanedimethanol is preferably 50/50 to 0/100, and more preferably 40/60 to 10/90.

  The component unit derived from 2,2,4,4-tetramethyl-cyclobutanediol is particularly difficult to adopt a conjugated structure in the molecule of the amorphous polyester resin (B). Therefore, when these amorphous polyester resins (B) contain component units derived from 2,2,4,4-tetramethyl-cyclobutanediol, coloring of the reflector is more easily suppressed and the reflectance is high. Become. The dialcohol component unit (b2) preferably contains 1 to 80 mol%, more preferably 1 to 60 mol% of a component unit derived from 2,2,4,4-tetramethyl-cyclobutanediol.

  The total amount of the component units derived from 1,4-cyclohexanedimethanol and the component units derived from 2,2,4,4-tetramethyl-cyclobutanediol is preferably 100 mol%.

  On the other hand, when the dialcohol component unit (b2) includes a component unit derived from (b2-2) 1,4-cyclohexanedimethanol and a component unit derived from an aliphatic dialcohol, the dialcohol component unit (b2) is The component unit derived from 1,4-cyclohexanedimethanol is preferably contained in an amount of 20 mol% or more and less than 40 mol%, more preferably 20 to 35 mol%. If the amount of the component unit derived from 1,4-cyclohexanedimethanol is within this range, the resin tends to be amorphous. In addition, the preferable cis / trans ratio of 1, 4- cyclohexane dimethanol is the same as that of the above-mentioned (b2-1).

  Further, the amount of the component unit derived from the aliphatic dialcohol is more preferably more than 60 mol% and 80 mol% or less, and further preferably 65 to 80 mol%. The aliphatic dialcohol preferably contains 4 to 20 carbon atoms. Specific examples of the aliphatic dialcohol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1, 8-octanediol, 1,10-decanediol, neopentyl glycol, 2,2,4-trimethyl-1,3-pentanediol and the like are included. Among these, ethylene glycol is preferable from the viewpoint that the transparency, heat resistance, and coloration resistance of the reflector are likely to increase.

  In addition, it is preferable that the total amount of the component unit derived from the said 1, 4- cyclohexane dimethanol and the component unit derived from aliphatic dialcohol is 100 mol%.

  However, in both cases (b2-1) and (b2-2), depending on the desired characteristics, the dialcohol component unit (b2) is derived from a small amount of aromatic dialcohol together with the component unit. It may further contain a component unit. Examples of the aromatic dialcohol 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 (b2) is preferably 10 mol% or less.

  Here, the intrinsic viscosity [η] of the amorphous polyester resin (B) is preferably 0.2 to 1.5 dl / g. When the intrinsic viscosity is in the above range, the fluidity during molding of the resin composition is increased. The intrinsic viscosity of the amorphous polyester resin (B) can be adjusted by the molecular weight of the amorphous polyester resin (B). Examples of methods for adjusting the molecular weight of the amorphous polyester resin (B) 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. Is included. The method for measuring the intrinsic viscosity of the amorphous polyester resin (B) can be the same as the intrinsic viscosity [η] of the crystalline polyester resin (A) described above.

  The amorphous polyester resin (B) may be produced by a known method, or a commercially available one may be purchased. Amorphous polyester resin (B), like the above-described crystalline polyester resin (A), is blended with a molecular weight regulator or the like in the reaction system, so that dicarboxylic acid component unit (b1) and dialcohol component unit (b2 ) Can be made to react. The intrinsic viscosity of the amorphous polyester resin (B) can be adjusted by blending a molecular weight modifier in the reaction system. The said molecular weight modifier and its addition amount can be made the same with the monocarboxylic acid and monoalcohol used for preparation of crystalline polyester resin (A).

  On the other hand, examples of commercially available amorphous polyester resin (B) include Tritan (registered trademark) TX2001, TX-1001, TX1501HF, TX2000 (both manufactured by Eastman Chemical Co.); PETG 6763, 14471 (both Eastman Chemical Co.).

(Contents of crystalline polyester resin (A) and amorphous polyester resin (B))
The ratio of the mass of the crystalline polyester resin (A) and the amorphous polyester resin (B) in the resin composition of the present invention (resin (A) / resin (B)) is 1/99 to 49/51. It is preferably 5/95 to 40/60, and more preferably 10/90 to 35/75. These ratios can be specified by, for example, ¹ H NMR spectrum. When the ratio of the content of the crystalline polyester resin (A) and the amorphous polyester resin (B) is in the above range, a reflective material having high heat resistance and hardly discolored by heating or light irradiation can be obtained.

  The total of the content of the crystalline polyester resin (A) and the content of the amorphous polyester resin (B) is the same as the crystalline polyester resin (A), the amorphous polyester resin (B), and the inorganic filler. When the amount of (C) and the white pigment (D) is 100% by mass, it is 30 to 80% by mass, more preferably 30 to 70% by mass, and further 40 to 60% by mass. preferable. When the total content of the crystalline polyester resin (A) and the amorphous polyester resin (B) is in the above range, the moldability of the resin composition is likely to be good, and the surface smoothness of the obtained reflector is also high. Become.

1-3. Inorganic filler (C)
The inorganic filler (C) is not particularly limited as long as it is a filler made of an inorganic compound having a spherical shape, a fiber shape, a plate shape, or the like. From the viewpoint of further increasing the strength and toughness of the resin composition, the shape of the inorganic filler (C) is preferably fibrous.

  Examples of fibrous inorganic fillers (C) 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. The resin composition may contain only one kind or two or more kinds. Of these, wollastonite, glass fiber, and potassium titanate whisker are preferable, and wollastonite or glass fiber is more preferable because the average fiber diameter is relatively small and the surface smoothness of the molded product is easily improved. Wollastonite is preferable from the viewpoint of further enhancing the light shielding effect of the reflecting material obtained from the resin composition, and glass fiber is preferable from the viewpoint of further increasing the mechanical strength of the reflecting material.

  The average fiber length of the fibrous inorganic filler (C) is preferably 1 μm to 20 mm from the viewpoint of maintaining good moldability and improving the mechanical properties and heat resistance of the resulting reflector, More preferably, it is 5 micrometers-10 mm, More preferably, it is 10 micrometers-5 mm. Moreover, it is preferable that the aspect-ratio of an inorganic filler (C) is 5-2000, More preferably, it is 30-600.

  The average fiber length and aspect ratio are measured as follows. For example, by dissolving and removing the resin component with a solvent from the resin composition containing the inorganic filler (C) and the reflective material containing the inorganic filler (C), or baking the resin composition and the reflective material Only the inorganic filler (C) is separated. The separated inorganic filler (C) is observed using an optical microscope or an electron microscope, and the major axis and minor axis of 100 inorganic fillers (C) are measured to calculate the aspect ratio.

  The inorganic filler (C) may be treated with a silane coupling agent or a titanium coupling agent. For example, the inorganic filler (C) may be surface-treated with a silane compound such as vinyltriethoxysilane, 2-aminopropyltriethoxysilane, or 2-glycidoxypropyltriethoxysilane.

  When the inorganic filler (C) is fibrous, a sizing agent may be applied to the inorganic filler (C). Preferable examples of the sizing agent include acrylic, acrylic / maleic acid modified, epoxy, urethane, urethane / maleic acid modified, urethane / epoxy modified compounds. Only one type of sizing agent may be applied, or two or more types may be applied in combination.

  Furthermore, the inorganic filler (C) may be treated with both a surface treatment agent and a sizing agent. When a surface treatment agent and a sizing agent are used in combination, the bonding between the inorganic filler (C) and the crystalline polyester resin (A) or the amorphous polyester resin (B) increases, and the resulting reflective material has a good appearance. Or the strength of the reflective material is likely to increase.

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

1-4. White pigment (D)
The white pigment (D) may be any pigment that can whiten the reflective material obtained from the resin composition and improve the light reflection function, but preferably has a refractive index of 2.0 or more. The upper limit of the refractive index of the white pigment (D) can be set to 4.0, for example. Examples of the white pigment (D) include titanium oxide, zinc oxide, zinc sulfide, lead white, zinc sulfate, barium sulfate, calcium carbonate, and alumina oxide. The resin composition may contain only one type of white pigment (D), or may contain two or more types.

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

  The white pigment (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 reflector obtained from the resin composition of the present invention more uniform, the white pigment (D) preferably has a small aspect ratio, that is, a spherical shape.

  From the viewpoint of further increasing the reflectance of the reflective material obtained from the resin composition of the present invention, the average particle diameter of the white pigment (D) is preferably 0.1 μm or more and 0.5 μm or less, preferably 0.15 μm or more. More preferably, it is 0.3 μm or less. The average particle size of the white pigment (D) is a distribution curve 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. Ask for. Then, a cumulative distribution curve is obtained from the obtained distribution curve, and a value at a cumulative degree of 50% in this cumulative distribution curve can be set as the average particle diameter.

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

1-5. Others The resin composition may contain a light stabilizer or an oxidation agent as necessary in addition to the above-described crystalline polyester resin (A), amorphous polyester resin (B), inorganic filler (C), and white pigment (D). An inhibitor, a crystal nucleating agent, a modified olefin polymer and the like may be contained.

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

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

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

  When the resin composition of the present invention contains a hindered amine light stabilizer, the content of the hindered amine light stabilizer is as follows: crystalline polyester resin (A), amorphous polyester resin (B), inorganic filler The total of (C) and the white pigment (D) is preferably 0.01 to 2% by mass, more preferably 0.02 to 1.5% by mass with respect to 100% by mass, and More preferably, it is 03-1.0 mass%.

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

  In a high temperature atmosphere (especially, conditions exceeding 250 ° C. as in the reflow soldering process), the decomposition reaction of the crystalline polyester resin (A) or the amorphous polyester resin (B) is suppressed, and the resin composition is discolored. From the viewpoint of suppression, the antioxidant is preferably a hindered phenol or phosphorus antioxidant.

  The content of the antioxidant is 10 when the total of the crystalline polyester resin (A), the amorphous polyester resin (B), the inorganic filler (C), and the white pigment (D) is 100% by mass. It is preferably at most mass%, more preferably at most 5 mass%, further preferably at most 1 mass%.

  Examples of the crystal nucleating agent include talc, organic metal salts, inorganic metal salts and the like. Among these, talc is preferable. When the resin composition contains a crystal nucleating agent, the mechanical strength of the reflector is likely to increase. The crystal nucleating agent is 0.01 to 5 when the total of the crystalline polyester resin (A), the amorphous polyester resin (B), the inorganic filler (C), and the white pigment (D) is 100% by mass. It is preferable that it is mass%, It is more preferable that it is 0.1-3 mass%, It is further more preferable that it is 0.3-1 mass%.

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

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

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

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

The content rate of the functional group structural unit which a modified olefin polymer contains is specified by well-known means, such as preparation ratio, < ¹³ > C-NMR measurement, and < ¹ > H-NMR measurement. The NMR measurement can be performed by, for example, the method described in paragraphs 0063 to 0065 of International Publication No. 2013/018360.

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

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

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

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

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

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

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

  A particularly preferred example of the functional group-containing compound is maleic anhydride. Maleic anhydride has a relatively high reactivity with the olefin polymer and does not change its structure greatly by polymerization or the like. For this reason, it is easy to obtain a modified olefin polymer having a stable quality.

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

  Graft modification of the ethylene / α-olefin copolymer can be performed, for example, by the method described in paragraphs 0058 to 0062 of International Publication No. 2013/018360.

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

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

  When the resin composition of the present invention contains a modified olefin polymer, the preferred content of the modified olefin polymer is a crystalline polyester resin (A), an amorphous polyester resin (B), an inorganic filler (C), And the total of the white pigment (D) is preferably 0.3 to 1.5% by mass, more preferably 0.5 to 1.3% by mass with respect to 100% by mass, More preferably, it is -1.1 mass%.

  When the content of the modified olefin polymer is 1.5% by mass or less, a resin composition in which the modified olefin polymer is uniformly dispersed and the viscosity is not biased is obtained. Therefore, when the inorganic filler (C) is in a fibrous form, the breakage is suppressed. Further, high toughness can be imparted without impairing the heat resistance of the reflecting material and the temporal stability of the reflectance. When the content of the modified olefin polymer is 0.3% by mass or more, the modified olefin polymer functions as a protective material (cushion material) for the inorganic filler (C), and the inorganic filler (C) is bent. Can be suppressed. Therefore, it becomes possible to make the reflective material exhibit toughness, heat resistance, and higher reflectance.

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

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

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

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

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

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

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

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

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

  The reflective material of the present invention thus produced comprises a crystalline polyester resin (A), an amorphous polyester resin (B), an inorganic filler (C), and a white pigment (D) with the above-mentioned composition ratio. Contains.

The reflective material preferably has a reflectance of light having a wavelength of 450 nm of 90% or more, and more preferably 93% or more. The said reflectance should just be the value measured by the well-known method, for example, can be made into the value obtained by measuring the molded object whose thickness is 0.5 mm using CM3500d by Konica Minolta. The reflectance of the reflecting material can be adjusted by, for example, the amount of white pigment. Moreover, it is preferable that the reflectance of the light of wavelength 450nm after a reflow test is 89% or more. Furthermore, the reflectance of light having a wavelength of 450 nm after a long-term heating test (for example, 500 hours) is preferably 85% or more, and more preferably 86% or more. Moreover, it is preferable that the reflectance of the light with a wavelength of 450 nm of a reflective material measured after irradiating with ultraviolet rays at 16 mW / cm ² for 500 hours is 87% or more. The reflectivity after the reflow test, the reflectivity after heating, and the reflectivity after ultraviolet irradiation can be adjusted by, for example, the amount of the amorphous polyester resin (B).

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

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

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

  In such an LED element, the reflective material is exposed to high-temperature heat in the above 2) and 3) processes, or receives light including visible light and ultraviolet light generated from the LED during use and heat. Or However, as described above, since the amorphous polyester resin (B) is difficult to be discolored, a high reflectance is maintained.

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

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

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

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

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

<Amorphous polyester resin (B)>
Amorphous polyester resin (B1): Tritan (registered trademark) TX2001 (manufactured by Eastman Chemical Co., Ltd.) (component unit derived from terephthalic acid: 100 mol% (in all dicarboxylic acid component units)), 1,4-cyclohexanedimethanol Component unit derived from: 77% (in all dialcohol component units), component unit derived from 2,2,4,4-tetramethyl-cyclobutanediol: 23 mol% (in all dialcohol component units), melting point: Not observed)
Amorphous polyester resin (B2): 6763 (manufactured by Eastman Chemical Co., Ltd.) (component unit derived from terephthalic acid: 100 mol% (in all dicarboxylic acid component units), component unit derived from 1,4-cyclohexanedimethanol) : 33% (in all dialcohol component units), component unit derived from ethylene glycol: 67 mol% (in all dialcohol component units), melting point: not observed)

<Inorganic filler (C)>
As the inorganic filler (C), glass fiber (manufactured by Nippon Electric Glass Co., Ltd., ECS03T-790DE, average fiber length: 3 mm, average diameter: 6 μm) was used.

  The average diameter of the inorganic filler (C) (glass fiber) was determined by observing the cross-sectional shape of 100 glass fibers using an optical microscope or an electron microscope. Specifically, an arbitrary point was selected from the outer periphery of the cross section of the glass fiber observed with an optical microscope or the like, and a circumscribed line circumscribing the point was drawn. And the external tangent parallel to the said external tangent was drawn, and the distance of these external tangents was measured. The said operation | work was performed about all the outer periphery of the cross section of glass fiber, the average value of the distance of a circumscribed line was calculated | required, and this was made into the average diameter.

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

<Others>
As other components, the following components were used as needed.
・ Phosphorus antioxidant (ADK STAB PEP-36, manufactured by ADEKA)
・ Phenolic antioxidant (Irganox 1010, manufactured by BASF)
・ Wax (High Wax 1120H, Mitsui Chemicals)
・ Crystal nucleating agent (high filler # 5000PJ, manufactured by Matsumura Sangyo Co., Ltd., talc)

2. Preparation of polyester resin composition for reflector [Example 1]
8.23 parts by mass of crystalline polyester resin (A), 43.9 parts by mass of amorphous polyester resin (B1), 10.0 parts by mass of glass fiber as inorganic filler (C), and titanium oxide as white pigment (D) 35.0 parts by mass, 0.08 parts by mass of a phosphorus-based antioxidant, 0.16 parts by mass of a phenol-based antioxidant, 2 parts by mass of wax, and 0.63 parts by mass of a crystal nucleating agent were prepared, respectively, and a tumbler blender These were mixed using The obtained mixture was melt-kneaded at a cylinder temperature of 300 ° C. with a twin-screw extruder (TEX30α manufactured by Nippon Steel Works). Thereafter, it was extruded into a strand shape. The extrudate was cooled in a water tank, and then the strands were drawn with a pelletizer and cut to obtain a polyester resin composition for a reflector in the form of pellets. The compound property of the obtained polyester resin composition for reflectors was good.

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

[Evaluation]
Various reflectances of the reflecting material obtained from the polyester resin composition for reflecting material obtained in each example and each comparative example, the fluidity of the resin composition, the bending strength of the reflecting material, and the like were measured by the following methods. Or evaluated.

<Reflectance>
(Initial reflectance)
The obtained pellet-shaped polyester resin composition for reflectors was injection molded under the following molding conditions using the following molding machine. Thus, a test piece having a length of 30 mm, a width of 30 mm, and a thickness of 0.5 mm was produced. About the obtained test piece, the reflectance of wavelength 360nm -740nm was calculated | required using CM3500d by Konica Minolta. And the reflectance of wavelength 450nm was made into the representative value of the reflectance of an initial stage reflecting material.
Molding machine: SE50DU, manufactured by Sumitomo Heavy Industries, Ltd.
Cylinder temperature: 300 ° C
Mold temperature: 150 ° C

(Reflectance after heating)
The sample piece whose initial reflectance was measured was left in an oven at 170 ° C. for 2 hours. Next, for this sample piece, a heat treatment (same heat treatment as the reflow soldering process) for 20 seconds at a surface temperature of 260 ° C. of the sample piece using an air reflow soldering device (AIS-20-82-C, manufactured by Atec Techtron Co., Ltd.). ) Three times. Then, the reflectance of the obtained sample piece was measured by the same method as the initial reflectance, and was used as the reflectance of the reflecting material after heating.

(Reflectance after long-term heating)
The sample piece whose initial reflectance was measured was left in an oven at 150 ° C. for 168 hours. Then, the reflectance of the test piece was measured by the same method as the initial reflectance, and the reflectance at a wavelength of 450 nm was used as a representative value of the reflectance (168 hours) of the reflector after long-term heating. The sample piece was further left in an oven at 150 ° C. for 332 hours. Thereafter, the reflectance of the test piece was measured by the same method as the initial reflectance, and the reflectance at a wavelength of 450 nm was used as the representative value of the reflectance (500 hours) of the reflector after long-term heating.

(Reflectance after UV irradiation)
The test piece whose initial reflectance was measured was irradiated with ultraviolet rays for 500 hours in the following ultraviolet irradiation apparatus. Then, the reflectance of the obtained sample piece was measured by the same method as the initial reflectance, and was used as the reflectance of the reflector after the ultraviolet irradiation.
・ Ultraviolet irradiation conditions Ultraviolet irradiation device: Daipura Wintes Co., Ltd. Super Winmini Output: 16 mW / cm ²

<Fluidity>
The obtained polyester resin composition for a reflector is injection-molded under the following conditions using a bar flow mold having a width of 10 mm and a thickness of 0.5 mm, and the flow length (mm) of the resin composition in the mold is determined. It was measured.
Injection molding machine: TUPARL TR40S3A manufactured by Sodick
Injection set pressure: 2000 kg / cm ²
Cylinder set temperature: 300 ° C
Mold temperature: 30 ℃

<Bending strength (toughness, strength, elastic modulus, and deflection amount)>
The polyester resin composition for reflectors was molded under the following molding conditions using the following injection molding machine to prepare a test piece having a length of 64 mm, a width of 6 mm, and a thickness of 0.8 mm. The test piece was left for 24 hours under a nitrogen atmosphere at a temperature of 23 ° C. Next, a bending test is performed in an atmosphere of a temperature of 23 ° C. and a relative humidity of 50%: AB5 manufactured by INTESCO, span 26 mm, bending speed 5 mm / min, and strength (toughness, strength, elastic modulus, and deflection amount) Was measured respectively.
Injection molding machine: TUPARL TR40S3A manufactured by Sodick
Molding machine cylinder temperature: 300 ° C
Mold temperature: 150 ° C

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

  As shown in Table 1 above, the ratio of the crystalline polyester resin (A) to the amorphous polyester resin (B) is 1/99 to 49/51, and the crystalline polyester resin (A) is amorphous. The reflective material obtained from the polyester resin composition for a reflective material containing the specific polyester resin (B), the inorganic filler (C), and the white pigment (D) in a predetermined ratio reflects even when exposed to a high temperature for a long time. There was little decrease in the reflectance of the material, and further, the toughness, strength, etc., and the elastic modulus were excellent (Examples 1 and 2).

  On the other hand, when the non-crystalline polyester resin was not included, the reflectivity reduction after ultraviolet irradiation was particularly large. Furthermore, toughness and strength were reduced (Comparative Example 1).

  The polyester resin composition for a reflective material of the present invention has high reflectance and further high strength. Moreover, even if the reflective material obtained from the said polyester resin composition for reflective materials is exposed to high temperature or is exposed to an ultraviolet-ray, a reflectance does not fall easily. Therefore, it is very useful as a reflector for various lighting devices.

Claims (7)

A total of 30 to 80% by mass of the crystalline polyester resin (A) having a melting point or glass transition temperature of 250 ° C. or higher and the amorphous polyester resin (B) in which the melting point is not observed,
Inorganic filler (C) 1-50 mass%,
5 to 50% by mass of white pigment (D) (the total of the crystalline polyester resin (A), the amorphous polyester resin (B), the inorganic filler (C), and the white pigment (D) is 100) Mass%), and
The ratio of the mass of the crystalline polyester resin (A) and the amorphous polyester resin (B) is 1/99 to 49/51,
The amorphous polyester resin (B) includes a dicarboxylic acid component unit (b1) derived from a dicarboxylic acid and a dialcohol component unit (b2) derived from a dialcohol,
The dicarboxylic acid component unit (b1) includes 60 to 100 mol% of a component unit derived from terephthalic acid,
The dialcohol component unit (b2) is derived from (b2-1) 1,99 mol% of component units derived from 1,4-cyclohexanedimethanol and 2,2,4,4-tetramethyl-cyclobutanediol. Component unit 99 to 1 mol%, or (b2-2) component unit 60 derived from 1,4-cyclohexanedimethanol and 20 mol% or more and less than 40 mol% derived from aliphatic dialcohol Including more than mol% and 80 mol% or less,
A polyester resin composition for reflectors. The component unit derived from the aliphatic dialcohol contained in the dialcohol component unit (b2) is a component unit derived from ethylene glycol.
The polyester resin composition for reflectors according to claim 1. The crystalline polyester resin (A) includes a dicarboxylic acid component unit (a1) derived from a dicarboxylic acid and a dialcohol component unit (a2) derived from a dialcohol,
The dicarboxylic acid component unit (a1) includes 30 to 100 mol% of component units derived from terephthalic acid, and 0 to 70 mol% of component units derived from an aromatic dicarboxylic acid other than terephthalic acid,
The dialcohol component unit (a2) includes a component unit derived from an alicyclic dialcohol having an alicyclic hydrocarbon skeleton having 4 to 20 carbon atoms and / or a component unit derived from an aliphatic dialcohol.
The polyester resin composition for reflectors according to claim 1 or 2. The dialcohol component unit (a2) includes 40 to 100 mol% of a component unit derived from 1,4-cyclohexanedimethanol and 0 to 60 mol% of a component unit derived from the aliphatic dialcohol.
The polyester resin composition for reflectors according to claim 3. The white pigment (D) is titanium oxide.
The polyester resin composition for reflectors as described in any one of Claims 1-4.   A reflective material comprising a molded article of the polyester resin composition for reflective material according to claim 1.   The reflective material according to claim 6 which is a reflective material for a light emitting diode element.