JP2013219158A - Thermoplastic resin for reflector material, and reflector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a polyester resin composition for reflectors which allows the achievement of a high mechanical strength in its mold, and enables the materialization of a reflector having good heat resistance and stably high reflectance, and especially less prone to suffer the reduction in reflectance owing to heating in LED production and reflow soldering processes and having good toughness; and a reflector including the resin composition.SOLUTION: A thermoplastic resin composition for reflector material, which achieves the above object, comprises 30-80 mass% of a polyester resin having a melting point or glass transition temperature of 250°C or higher, 1-50 mass% of an inorganic filler (B), 5-50 mass% of a white pigment (C), and 0.1-15 mass% of an olefin polymer (D) having a particular functional group content rate to 100 mass% of A,B,C and D in total.

Description

  The present invention relates to a resin composition that is suitable for a reflective material and can be used even at high temperatures, and a reflector obtained by molding the resin composition. More specifically, a thermoplastic resin composition for a reflector that includes a specific thermoplastic resin, a specific inorganic filler, and a white pigment, is excellent in light reflectance, heat resistance, and mechanical properties, and is suitable for insert molding. And a reflector obtained by molding the resin composition.

  In order to efficiently use light, reflectors have been used in various aspects, but in recent years, semiconductors of light sources for miniaturization of devices and miniaturization of light sources, that is, semiconductor lasers, light emitting diodes (hereinafter referred to as LEDs) are used. The switch to ”is progressing. For this reason, not only mechanical strength but also surface mounting on a printed wiring board or the like is performed on the reflecting plate, so that it is required to have good heat resistance and to be precisely molded. In addition, the reflecting plate is required to have a stable and high reflectivity in terms of the function of reflecting light, and in particular, it is necessary to suppress a decrease in reflectivity due to heating during LED assembly and reflow soldering processes. .

  In recent years, there has been an increasing demand for cost reduction of products, and the number of LED packages mounted on final products such as TVs, monitors, etc., and the resulting increase in brightness, miniaturization of products, and LED by injection molding. Due to an increase in the number of packages used for manufacturing, a material having high melt fluidity is required. Furthermore, further improvements in strength and toughness associated with downsizing are being demanded.

  As a technique for suppressing the decrease in reflectance, a method based on improvement of a base polymer has been disclosed so far (Patent Document 1). In many cases, a polyamide material is used for the reflecting plate, but discoloration may occur due to the amino group at the terminal or the amide bond, that is, the reflectance may decrease. In contrast, attempts have been made to use heat-resistant polyester instead of polyamide resin. However, there is no disclosure regarding mechanical strength and fluidity due to the change of the base polymer from polyamide to heat-resistant polyester, and the performance balance as a reflective material is unknown. On the other hand, as a method for increasing strength and toughness, a method using a composition containing a heat-resistant polyester and a glycidyl methacrylate polymer is disclosed.

Special table 2009-507990

  According to the study by the present inventors, the composition containing the heat-resistant polyester and the glycidyl methacrylate polymer is excellent in mechanical strength balance such as toughness, while the temporal stability of the reflectance and the melt fluidity as a resin composition. It has been found that further improvement is necessary in terms of the above.

  Therefore, the present invention is particularly excellent in mechanical strength of molded products represented by toughness, excellent heat resistance, high reflectivity, excellent moldability, and further by heating such as LED manufacturing process and reflow soldering process. It is an object of the present invention to obtain a thermoplastic resin composition for a reflector, which can obtain a reflector with little reduction in reflectance, and a reflector containing the resin composition.

  As a result of intensive studies in view of such circumstances, the present inventors have found that a composition comprising an olefin polymer having a specific structure and a thermoplastic resin having a high melting point or glass transition temperature and a white pigment has heat resistance, The present invention has been completed by finding out that it has high levels of toughness, moldability, and reflectivity stability over time.

That is, the constituent requirements of the present invention are:
30-80% by mass of a polyester resin (A) having a melting point or glass transition temperature of 250 ° C. or higher,
1-50% by mass of inorganic filler (B),
Olefin polymer (D) 0.1-15% by mass containing white pigment (C) 5-50% by mass and functional group structural unit 0.1-1.8%
Is a thermoplastic resin composition for reflectors. (However, the total of A, B, C, and D is 100% by mass.)

  In the thermoplastic resin composition for a reflector according to the present invention, the polyester resin (A) has a dicarboxylic acid component unit derived from terephthalic acid in an amount of 30 to 100 mol%, and an aromatic dicarboxylic acid component unit other than terephthalic acid in an amount of 0 to 70 mol. % And / or a dicarboxylic acid component unit (a-1) composed of 0 to 70 mol% of an aliphatic dicarboxylic acid component unit having 4 to 20 carbon atoms and an alicyclic dialcohol component unit having 4 to 20 carbon atoms ( It is preferably selected from a polyester resin (A-2) containing a-3) and / or an aliphatic dialcohol component unit (a-4).

  In the thermoplastic resin composition for a reflector of the present invention, the dialcohol component unit (a-3) contained in the polyester resin (A-2) preferably has a cyclohexane skeleton.

  In the thermoplastic resin composition for a reflector of the present invention, the inorganic filler (B) is preferably a calcium carbonate whisker.

  In the thermoplastic resin composition for a reflector according to the present invention, the inorganic filler (B) preferably contains two or more inorganic fillers having different average lengths and aspect ratios.

  The thermoplastic resin composition for a reflector according to the present invention includes an inorganic filler (B) containing a carbonyl structure and having an aspect ratio of 1 to 300, and an inorganic filler having a different average length and aspect ratio. Are preferably included.

  In the thermoplastic resin composition for a reflector of the present invention, the olefin polymer (D) preferably contains a functional group selected from carboxylic acid, ester, ether, aldehyde, and ketone.

  In the thermoplastic resin composition for a reflective material of the present invention, the olefin polymer (D) preferably contains a maleic anhydride structural unit.

  Moreover, this invention is a reflecting plate containing the said thermoplastic resin composition for reflecting plates.

  The reflector of the present invention is preferably a reflector for a light emitting diode element.

  According to the present invention, the molded product has high mechanical strength, excellent heat resistance, excellent fluidity and moldability, and has little decrease in reflectance over time, and particularly reflected by heating in the LED manufacturing process and reflow soldering process. It is possible to provide a resin composition for a reflector plate with a small decrease in the rate and a reflector plate obtained by molding the resin composition. For this reason, the industrial value of the present invention is extremely high.

Hereinafter, the present invention will be described in detail.
[Polyester resin (A)]
The polyester resin (A) suitably used in the present invention preferably has a structure having a structural unit derived from an aromatic dicarboxylic acid and a structural unit derived from a dialcohol having a cyclic skeleton.

  As such a carboxylic acid-derived structural unit, as the dicarboxylic acid component unit (a-1), terephthalic acid component unit 30 to 100 mol% and aromatic dicarboxylic acid component units other than terephthalic acid 0 to 70 mol % And / or an aliphatic dicarboxylic acid component unit having 4 to 20 carbon atoms is preferably 0 to 70 mol%, and the total amount of these dicarboxylic acid component units (a-1) is 100 mol%. Among these, as the aromatic dicarboxylic acid component unit other than terephthalic acid, for example, isophthalic acid, 2-methylterephthalic acid, naphthalenedicarboxylic acid, and combinations thereof are preferable. The aliphatic dicarboxylic acid component unit is not particularly limited in the number of carbon atoms, but is derived from an aliphatic dicarboxylic acid having 4 to 20, preferably 6 to 12 carbon atoms. Examples of aliphatic dicarboxylic acids used to derive such aliphatic dicarboxylic acid component units include, for example, adipic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid Etc.

  In the present invention, an alicyclic dicarboxylic acid such as cyclohexanedicarboxylic acid can be used as a raw material.

  In the present invention, the dicarboxylic acid component unit is preferably 40 to 100 mol% of terephthalic acid component units, preferably 0 to 60 mol% of aromatic dicarboxylic acid component units other than terephthalic acid, and / or the number of carbon atoms. 4 to 20, preferably 6 to 12, aliphatic dicarboxylic acid component units are preferably included in an amount of 0 to 60 mol%.

  In the present invention, the dicarboxylic acid component unit (a-1) may contain a polyvalent carboxylic acid component unit in a small amount, for example, an amount of about 10 mol% or less, in addition to the structural unit as described above. . Specific examples of such polyvalent carboxylic acid component units include tribasic acids and polybasic acids such as trimellitic acid and pyromellitic acid.

  On the other hand, diols having an alicyclic skeleton include alicyclic glycols such as 1,4-cyclohexanediol and 1,4-cyclohexanedimethanol, bisphenol, hydroquinone, 2,2-bis (4-β-hydroxyethoxyphenyl). Aromatic diols such as propanes can be used as raw materials. From the viewpoint of heat resistance and moldability, alicyclic glycols are more preferable.

  In the case of alicyclic glycols, there are isomers such as cis and trans structures, but the trans structure is preferred from the viewpoint of heat resistance. Therefore, the cis / trans ratio is preferably 50/50 to 0/100, more preferably 40/60 to 0/100.

  In the present invention, in addition to the diol having the cyclic skeleton, an aliphatic diol can be used in combination for the purpose of improving the melt fluidity as a resin. Specific examples include ethylene glycol, trimethylene glycol, propylene glycol, tetramethylene glycol, neopentyl glycol, hexamethylene glycol, and dodecamethylene glycol.

  Further, the polyester resin (A) is 30 to 80% by mass, preferably 30 to 70% by mass, in the total amount of 100% by mass of the polyester resin (A), the inorganic filler (B) and the white pigment (C). It adjusts so that it may become a ratio of 40-60 mass%.

  The polyester resin (A) used in the present invention has a melting point (Tm) or glass transition temperature (Tg) measured by a differential scanning calorimeter (DSC) of 250 ° C. or higher. A preferred lower limit is 270 ° C, more preferably 290 ° C. On the other hand, the preferable upper limit is 350 ° C., and more preferably 335 ° C. When the melting point or glass transition temperature is 250 ° C. or higher, the deformation of the reflector during reflow soldering is suppressed. The upper limit temperature is not limited in principle, but a melting point or glass transition temperature of 350 ° C. or lower is preferable because decomposition of the polyester resin can be suppressed during melt molding.

  The intrinsic viscosity [η] of the polyester resin (A) is preferably 0.3 to 1.0 dl / g. When the intrinsic viscosity is in such a range, the fluidity at the time of molding of the thermoplastic resin composition for a reflector can be excellent. The intrinsic viscosity of the polyester resin (A) can be adjusted by adjusting the molecular weight of the polyester resin (A). As a method for adjusting the molecular weight of the polyester resin, a known method such as a degree of progress of the polycondensation reaction or an appropriate amount of a monofunctional carboxylic acid or a monofunctional alcohol can be employed.

The above intrinsic viscosity is obtained by dissolving the polyester resin (A) in a mixed solvent of 50/50% by mass of phenol and tetrachloroethane, and using a Ubbelohde viscometer and flowing the sample solution under the condition of 25 ° C. ± 0.05 ° C. It is a value calculated by the following formula after measuring the number of seconds.
[η] = ηSP / [C (1 + 0.205ηSP)]
[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 that the solvent flows (seconds)
ηSP = (t−t0) / t0

  Moreover, in this invention, you may use together multiple polyester resin (A) from which a physical property differs as needed. Further, other thermoplastic resins may be used in combination as long as they are within the object of the present invention.

[Inorganic filler (B)]
As the inorganic filler (B) used in the present invention, known inorganic fillers can be used without limitation. Specifically, it is preferable to use various inorganic reinforcing materials having a shape having a high aspect ratio, such as a fibrous shape, a powdery shape, a granular shape, a plate shape, a needle shape, a cloth shape, and a mat shape. Specific examples include glass fibers, whiskers of carbonates such as calcium carbonate, hydrotalcite, titanates such as potassium titanate, wollastonite, and zonotlite. The average length of the inorganic filler as described above is in the range of 10 μm to 10 mm, preferably 10 μm to 5 mm, and the aspect ratio (L average fiber length / D average fiber diameter) is 1 to 500, preferably 10 to 350. It is in the range. Use of an inorganic filler in such a range is preferable in terms of improvement in strength and reduction in linear expansion coefficient.

  Among these, it is preferable that they are glass fiber (BG) and the inorganic compound (BW) which has a carbonyl structure. These inorganic fillers may be treated with a known compound such as a silicone compound. In particular, glass fiber treated with a silicone compound is one of preferred embodiments.

  Further, the inorganic filler (B) is 1 to 50% by mass, preferably 5 to 40% by mass, in a total amount of 100% by mass of the polyester resin (A), the inorganic filler (B) and the white pigment (C). Furthermore, it is preferable to use it so that it may become a ratio of 15-35 mass%.

  The inorganic filler (B) used in the present invention may be used in combination of two or more inorganic fillers having different lengths and different aspect ratios.

  Specific examples of the inorganic filler having a large length and aspect ratio include the aforementioned glass fibers, silicates such as wollastonite (calcium silicate), and titanates such as potassium titanate whiskers. Among these, glass fiber is preferable.

  The lower limit of the preferable length of the inorganic filler having such a large length and aspect ratio is 15 μm, preferably 30 μm, more preferably 50 μm. On the other hand, a preferable upper limit is 10 mm, more preferably 8 mm, still more preferably 6 mm, and particularly preferably 5 mm. Particularly in the case of glass fiber, the preferable lower limit is 500 μm, more preferably 700 μm, and further preferably 1 mm. Moreover, the preferable lower limit of the aspect ratio of such an inorganic filler is 20, more preferably 50, and still more preferably 90. On the other hand, the preferred upper limit is 500, more preferably 400, and even more preferably 350.

  As an example of the inorganic filler whose length and aspect ratio are relatively smaller than the above-mentioned inorganic filler, an inorganic filler (BW) having a carbonyl group can be cited as a preferred example, and specifically, carbonic acid such as calcium carbonate. List salt whiskers. The aspect ratio of the inorganic filler having a carbonyl group is preferably 1 to 300, more preferably 5 to 200, and still more preferably 10 to 150.

  When these inorganic fillers are combined, the dispersibility of the inorganic filler component in the base polymer is improved, and the affinity between the base polymer and the reinforcing material is improved, so that only heat resistance, mechanical strength, etc. are improved. In some cases, the dispersibility of the white pigment (C) described later may be improved.

[White pigment (C)]
The white pigment (C) used in the present invention may be any pigment that can improve the light reflection function by whitening the resin in combination with the polyester resin (A). Specific examples include titanium oxide, zinc oxide, zinc sulfide, white lead, zinc sulfate, barium sulfate, calcium carbonate, and alumina oxide. These white pigments may be used alone or in combination of two or more. These white pigments can also be used after being treated with a silane coupling agent or a titanium coupling agent. For example, the surface treatment may be performed with a silane compound such as vinyltriethoxysilane, 2-aminopropyltriethoxysilane, or 2-glycidoxypropyltriethoxysilane.

  As the white pigment, titanium oxide is particularly preferable. By using titanium oxide, optical characteristics such as reflectivity and concealability are improved. Titanium oxide is preferably a rutile type. The particle diameter of titanium oxide is 0.1 to 0.5 μm, preferably 0.15 to 0.3 μm.

  These white pigments preferably have a small aspect ratio, that is, a spherical shape, for the purpose of making the reflectance uniform.

  The white pigment (C) is 5 to 50% by mass, preferably 10 to 50% by mass, in a total amount of 100% by mass of the thermoplastic resin (A), the inorganic filler (B) and the white pigment (C). Furthermore, it is preferable to adjust so that it may become a ratio of 10-40 mass%.

[Olefin polymer]
The olefin polymer (D) of the present invention contains 0.1 to 1.8% by mass of a functional group structural unit with respect to 100% by mass of the corresponding olefin polymer. These functional groups are preferably functional groups containing a hetero atom. More specifically, a functional group containing carbon, hydrogen, and oxygen is a preferred embodiment, and more specific examples include an ester group, a carboxylic acid group, an aldehyde group, and a ketone group.

  The olefin polymer skeleton portion of the olefin polymer (D) is preferably a known polymer skeleton such as an ethylene polymer, a propylene polymer, a butene polymer or a copolymer of these olefins. . A particularly preferred olefin polymer skeleton is a copolymer of ethylene and an olefin having 3 or more carbon atoms.

  The olefin polymer (D) of the present invention can be obtained, for example, by reacting a corresponding known olefin polymer with a compound having a corresponding functional group at a specific ratio. One preferred example of the olefin polymer is an ethylene / α-olefin copolymer. Hereinafter, it describes about the case where an ethylene-alpha-olefin copolymer is used as an olefin polymer.

  The ethylene / α-olefin copolymer is ethylene and other olefins such as propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene and the like. 10 to α-olefin copolymer. Specific examples of the ethylene / α-olefin copolymer before modification in the present invention include an ethylene / propylene copolymer, an ethylene / 1-butene copolymer, an ethylene / 1-hexene copolymer, an ethylene / 1- Examples thereof include an octene copolymer and an ethylene-4-methyl-1-pentene copolymer. Among these, an ethylene / propylene copolymer, an ethylene / 1-butene copolymer, an ethylene / 1-hexene copolymer, and an ethylene / 1-octene copolymer are preferable.

  In the ethylene / α-olefin copolymer in the present invention, the structural unit derived from ethylene is 70 to 99.5 mol%, preferably 80 to 99 mol%, and the structural unit derived from α-olefin is 0.5 to 30. It is desirable that it is mol%, preferably 1 to 20 mol%.

  The ethylene / α-olefin copolymer in the present invention 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 minutes, preferably 0.05 to 20 g / 10 minutes. Is desirable.

  The method for producing the ethylene / α-olefin copolymer of the present invention is not particularly limited. For example, transition metal catalysts such as titanium (Ti), vanadium (V), chromium (Cr), or zirconium (Zr) are used. Can be prepared by a known method. More specifically, it is produced by copolymerizing ethylene and one or more kinds of α-olefin 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. A method can be illustrated. In particular, a process using a metallocene catalyst is suitable.

  In order to obtain the olefin polymer (D) of the present invention using such a polymer, the ethylene / α-olefin copolymer is so-called graft-modified with a functional group-containing compound corresponding to the functional group structural unit. This is an example.

  Particularly preferred examples of the functional group-containing compound are unsaturated carboxylic acids or derivatives thereof, specifically acrylic acid, methacrylic acid, α-ethylacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, Unsaturated carboxylic acids such as tetrahydrophthalic acid, methyltetrahydrophthalic acid, endocis-bicyclo [2,2,1] hept-5-ene-2,3-dicarboxylic acid (Nadic acid [trademark]), and their acid halides and amides , Derivatives of imide, acid anhydride, ester and the like. Among these, unsaturated dicarboxylic acids or acid anhydrides thereof are preferable, and maleic acid, nadic acid (trademark), or acid anhydrides thereof are particularly preferable.

  Graft modification of the ethylene / α-olefin copolymer can be carried out by a known method, for example, the ethylene / α-olefin copolymer is dissolved in an organic solvent, and then the unsaturated carboxylic acid or Examples thereof include a method in which the derivative and a radical initiator are added, and the reaction is usually performed at a temperature of 60 to 350 ° C., preferably 80 to 190 ° C., for 0.5 to 15 hours, preferably 1 to 10 hours.

  The organic solvent is not particularly limited as long as it is an organic solvent that can dissolve the ethylene / α-olefin copolymer. Examples of such an organic solvent include aromatic hydrocarbon solvents such as benzene, toluene, and xylene, and aliphatic hydrocarbon solvents such as pentane, hexane, and heptane.

  Another graft modification method includes a method of reacting an ethylene / α-olefin copolymer with an unsaturated carboxylic acid or a derivative thereof using an extruder or the like, preferably without using a solvent. . The reaction conditions in this case are that the reaction temperature is usually higher than the melting point of the ethylene / α-olefin copolymer, specifically 100 to 350 ° C., and the reaction time is usually 0.5 to 10 minutes.

  In order to efficiently graft copolymerize the functional group-containing compound such as the unsaturated carboxylic acid, the reaction is preferably performed in the presence of a radical initiator. Examples of the radical initiator include organic peroxides, organic peroxides such as benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di (peroxidebenzoate) hexyne -3,1,4-bis (t-butylperoxyisopropyl) benzene, lauroyl peroxide, t-butylperacetate, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3,2,5 -Dimethyl-2,5-di (t-butylperoxy) hexane, t-butylperbenzoate, t-butylperphenylacetate, t-butylperisobutyrate, t-butylper-sec-octoate, t-butylperpi Valate, cumyl perpivalate and t Butyl peroxide diethyl acetate; azo compounds such as azobisisobutyronitrile, dimethyl azoisobutyrate is used. Among these, dicumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3,2,5-dimethyl-2,5-di (t- Dialkyl peroxides such as butylperoxy) hexane and 1,4-bis (t-butylperoxyisopropyl) benzene are preferred. The radical initiator is usually used at a ratio of 0.001 to 1 part by weight with respect to 100 parts by weight of the ethylene / α-olefin copolymer before modification.

The ethylene / α-olefin copolymer (D), which is one of the preferred embodiments of the olefin polymer (D) used in the present invention, has a preferred density of 0.80 to 0.95 g / cm ³ , more preferably 0.8. 85 to 0.90 g / cm ³ . The content of the functional group-containing compound in the modified ethylene / α-olefin copolymer (D1) is usually 0.1 to 1.8% by weight, preferably 0.2 to 1.5% by weight. Further, the intrinsic viscosity [η] measured in a 135 ° C. decalin (decahydronaphthalene) solution of the ethylene / α-olefin copolymer (D1) is preferably 1.5 to 4.5 dl / g, more preferably 1. 6-3 dl / g. When [η] is within the above range, the toughness and melt fluidity of the resin composition of the present invention can be compatible at a high level.

In addition, 135 [deg.] C. of olefin polymer (D) and [[eta]] in decalin are measured as follows based on a conventional method.
20 mg of a sample is dissolved in 15 ml of decalin, and the specific viscosity (ηsp) is measured in an atmosphere of 135 ° C. using an Ubbelohde viscometer. After adding 5 ml of decalin to the decalin solution and diluting, the same specific viscosity is measured. Based on the measurement result obtained by repeating this dilution operation and viscosity measurement twice more, the “ηsp / C” value when the concentration (: C) was extrapolated to zero was defined as the intrinsic viscosity [η].

  A particularly preferred functional group-containing compound is maleic anhydride. Maleic anhydride has a relatively high reactivity with an olefin polymer to be described later, and itself has a large structural change due to polymerization and tends to be stable as a basic structure. For this reason, there are various advantages such as obtaining a stable quality olefin polymer (D).

  The content of the functional group structural unit contained in the olefin polymer (D) of the present invention is 0.1 to 1.8% by mass, preferably 0.2 to 1.5% by mass, and more preferably 0.2 to 1.2% by mass. When there are too few functional group structural units, the effect of improving the toughness of the resin composition described later may be low. This is because the interaction between the olefin polymer (D) and the polyester resin (A) is too weak and the olefin polymer (D) is likely to aggregate, making it difficult to exhibit a sufficient toughness improving effect. On the other hand, when there are too many functional group structural units, the interaction with the thermoplastic resin (A) becomes too strong and the melt fluidity is lowered, and as a result, the moldability may be lowered. In addition, this excessive functional group may undergo coloration due to modification with heat or light, and as a result, the reflectance stability over time may decrease. In addition, when a large number of functional group structural units are introduced into the olefin polymer, unreacted functional group-containing compounds tend to remain, and these unreacted compounds may accelerate the problem due to the modification.

The content of these functional group structural units is known in the known ratios such as the charging ratio when the olefin polymer and the functional group-containing compound are reacted in the presence of a radical initiator, ¹³ C NMR measurement, ¹ H NMR measurement, etc. It can be done by means. Specific conditions for NMR measurement include the following conditions.

^In the case of ¹ H NMR measurement, an ECX400 type nuclear magnetic resonance apparatus manufactured by JEOL Ltd. is used, 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 μs (45 ° pulse), the repetition time is 7.0 seconds, and the number of integration is 500 times or more. The standard chemical shift is 0 ppm for tetramethylsilane hydrogen. For example, the same result can be obtained by setting the peak derived from residual hydrogen in deuterated orthodichlorobenzene to 7.10 ppm and setting the standard value for chemical shift. I can do it. Peaks such as ¹ H derived from the functional group-containing compound were assigned by a conventional method.

^In the case of ¹³ C NMR measurement, the measuring device is an ECP500 type nuclear magnetic resonance device manufactured by JEOL Ltd., a mixed solvent of orthodichlorobenzene / heavy benzene (80/20 vol%) as a solvent, a measurement temperature is 120 ° C., and an 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, and 27.50 ppm is a standard value for chemical shift. Assignment of various signals is performed based on a conventional method, and quantification can be performed based on an integrated value of signal intensity.

  As another method for measuring the content of the functional group structural unit, the functional group content of polymers having different functional group contents is determined by the NMR measurement, and infrared spectroscopy ( IR) measurement is performed, a calibration curve is created based on the intensity ratio of a specific peak, and the functional group content is determined based on this result. This method is simpler than the NMR measurement described above, but basically it is necessary to prepare a corresponding calibration curve depending on the type of base resin and functional group. For this reason, this method is preferably used for, for example, process management in resin production in a commercial plant.

  These olefin polymers (D) are used in a proportion of 0.1 to 15% by mass, where the sum of the components (A) to (D) is 100% by mass. Preferably it is 0.5-15 mass%, More preferably, it is 1-12 mass%.

[Other additives]
In the present invention, the following additives, that is, antioxidants (phenols, amines, sulfurs, phosphorus, etc.), heat stabilizers (lactone compounds, Vitamins E, hydroquinones, copper halides, iodine compounds, etc.), light stabilizers (benzotriazoles, triazines, benzophenones, benzoates, hindered amines, ogizanides, etc.), other polymers (polyolefins: ethylene)・ Propylene copolymer, olefin copolymer such as ethylene / 1-butene copolymer, olefin copolymer such as propylene / 1-butene copolymer, polystyrene, etc.), flame retardant (bromine, chlorine, phosphorus, etc.) Fluorescent whitening agents, plasticizers, thickeners, antistatic agents, mold release agents, pigments, crystal nucleating agents, various known coatings Agent can be added.

  These additives vary depending on the type of the component, but 0 to 10% by mass is preferable with respect to 100% by mass of the thermoplastic resin of the present application, more preferably 0 to 5% by mass, and still more preferably 0 to 1% by mass. Used in proportions.

[Thermoplastic resin composition of the present invention]
The polyester resin composition of the present invention is prepared by mixing the above-described components by a known method, for example, a Henschel mixer, a V blender, a ribbon blender, a tumbler blender, or the like. Further, it can be produced by a method of granulation or pulverization after melt-kneading with a kneader, Banbury mixer or the like.

  The polyester resin composition of the present invention comprises a polyester resin (A), an inorganic filler (B), a white pigment (C), and an olefin polymer (D) in a total amount of 100% by mass. It is preferable to contain in the ratio of -80 mass%, Preferably 30-70 mass%, Furthermore, 40-60 mass%. When the polyester resin (A) is 30% by mass or more and 80% by mass or less, a thermoplastic resin composition having excellent heat resistance that can withstand the solder reflow process can be obtained without impairing moldability.

  Moreover, it is preferable that the polyester resin composition of this invention contains an inorganic filler (B) in the ratio of 1-50 mass%, Preferably it is 5-40 mass%, More preferably, it is 15-35 mass%. When the amount of the inorganic filler (B) is 5% by mass or more, the molded product is not deformed at the time of injection molding or a solder reflow process, and the stability of reflectance with time tends to be excellent. Moreover, a molded article with favorable moldability and external appearance can be obtained as it is 60 mass% or less.

  Moreover, the polyester resin composition of this invention contains a white pigment (C) in the ratio of 5-50 mass%, Preferably it is 10-50 mass%, More preferably, it is 10-40 mass%. When the amount of the white pigment (C) is 5% by mass or more, sufficient light reflection characteristics such as reflectance can be obtained. Moreover, if it is 50 mass% or less, a moldability is not impaired and it is preferable.

  Moreover, the polyester resin composition of this invention contains an olefin polymer (D) in the ratio of 0.1-15 mass%, Preferably it is 0.5-15 mass%, More preferably, it is 1-12 mass%. When the amount of the olefin polymer (D) is 0.1% by mass or more, in addition to toughness and heat resistance, a high reflectance tends to be stably expressed over time. Moreover, if it is 15 mass% or less, high toughness can be provided, without impairing high heat resistance or the temporal stability of a reflectance.

  The thermoplastic resin composition for a reflector of the present invention in the composition range as described above is excellent in mechanical properties, reflectance and heat resistance, and can be suitably used for reflector applications.

[Reflector, reflector for light emitting diode element]
Reflector includes general casings and housings that are open or not open at least in the direction of light emission. More specifically, the reflector has a box shape or a box shape, or a funnel shape. Reflecting light, such as those having the shape of a bowl, those having a bowl shape, those having a parabolic shape, those having a cylindrical shape, those having a conical shape, those having a honeycomb shape, etc. It also includes general three-dimensional shapes having a plate-like (plane, spherical, curved surface, etc.) surface shape.

  The reflector obtained using the resin composition of the present invention is excellent in heat resistance, reflectance stability over time, and also in toughness, so it is highly possible that even a thin wall shape can have sufficient strength. Therefore, it is expected to contribute to lightening and downsizing of LED elements and the like.

  Reflectors for light emitting diode (LED) elements are usually made of polyamide resin or resin composition containing polyamide resin and an inorganic filler, injection molding, especially metal insert molding such as hoop molding, melt molding, extrusion molding, inflation molding. It is obtained by shaping into a desired shape by heat molding such as blow molding, and the LED element and other parts are incorporated into the reflecting plate and used by sealing, bonding, bonding, etc. with a sealing resin The

  Moreover, the polyamide resin composition and reflector of the present invention can be applied not only to LED applications but also to other applications that reflect light. As a specific example, it can be used as a reflector for light emitting devices such as various electric and electronic components, indoor lighting, ceiling lighting, outdoor lighting, automobile lighting, display equipment, and headlights.

[Bending test]
Using the following injection molding machine, a test piece having a length of 64 mm, a width of 6 mm, and a thickness of 0.8 mm prepared under the following molding conditions was allowed to stand at a temperature of 23 ° C. and a nitrogen atmosphere for 24 hours. Next, a bending test was performed at a temperature of 23 ° C. and a relative humidity of 50% at a bending test machine: ABSCO manufactured by NTSCO Corporation, span 26 mm, bending speed 5 mm / min, and the strength, deflection amount, elastic modulus, and its test piece were determined. The energy (toughness) required to break was measured.
Molding machine: Sodick Plustech Co., Ltd. Tupar TR40S3A
Molding machine cylinder temperature: melting point (Tm) + 10 ° C., mold temperature: 150 ° C.

[Melting point (Tm)]
Using a PerkinElmer DSC7, the temperature was once maintained at 330 ° C. for 5 minutes, then cooled to 23 ° C. at a rate of 10 ° C./minute, and then heated at 10 ° C./minute. The endothermic peak based on melting at this time was defined as the melting point.

[ ¹ H NMR measurement]
Using an ECX400 nuclear magnetic resonance apparatus manufactured by JEOL Ltd., 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), and the sequence is The single pulse, the pulse width is 5.12 μsec (45 ° pulse), the repetition time is 7.0 seconds, and the number of integration is 500 times or more. The standard chemical shift was 7.10 ppm with the peak derived from residual hydrogen in deuterated orthodichlorobenzene. Peaks such as ¹ H derived from the functional group-containing compound were assigned by a conventional method.

[Initial reflectance]
A test piece having a length of 30 mm, a width of 30 mm, and a thickness of 0.5 mm prepared by injection molding under the following molding conditions was obtained using the following molding machine.

Molding machine: SE50DU, manufactured by Sumitomo Heavy Industries, Ltd.
Cylinder temperature: melting point (Tm) + 10 ° C., mold temperature: 150 ° C.
The reflectance of the wavelength region from 360 nm to 740 nm was determined for the obtained test piece using Minolta CM3500d. The initial reflectance was evaluated using the reflectances at 450 nm and 550 nm as representative values.

[Reflectance after heating]
The sample used for the initial reflectance measurement was left in an oven at 150 ° C. for 336 hours. The reflectance of this sample was measured by the same method as the initial reflectance, and was defined as the reflectance after heating.

[Liquidity]
A bar flow mold having a width of 10 mm and a thickness of 0.5 mm was used for injection under the following conditions, 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 set temperature: melting point (Tm) + 10 ° C., mold temperature: 30 ° C.

[Density of olefin polymer]
A sheet of 0.5 mm thickness was formed at a pressure of 100 kg / cm ² using a hydraulic heat press machine manufactured by Shindo Metal Industry Co., Ltd. set at 190 ° C. (spacer shape: 45 × on a 240 × 240 × 0.5 mm thick plate) 45 × 0.5 mm, 9 pieces), using another hydraulic hot press machine manufactured by Shinfuji Metal Industry Co., Ltd. set to 20 ° C., and cooled by compressing at a pressure of 100 kg / cm ² to prepare a measurement sample. . As the hot plate, a 5 mm thick SUS plate was used.
The press sheet was heat-treated at 120 ° C. for 1 hour, linearly cooled to room temperature over 1 hour, and then measured with a density gradient tube.

(Example of polyester resin production method)
Add 0.0037 parts of tetrabutyl titanate to 106.2 parts of dimethyl terephthalate 106.2 parts and 1,4-cyclohexanedimethanol (cis / trans ratio: 30/70), and take 150 hours to 300 degrees C for 3 hours 30 minutes. The temperature rose. (Transesterification reaction)
At the end of the transesterification reaction, 0.066 part of magnesium acetate tetrahydrate dissolved in 1,4-cyclohexanedimethanol was added, and then 0.1027 part of tetrabutyl titanate was introduced to carry out a polycondensation reaction.

  In the polycondensation reaction, the pressure is gradually reduced from normal pressure to 1 Torr over 85 minutes, and at the same time, the temperature is raised to a predetermined polymerization temperature of 300 ° C., the temperature and pressure are maintained, and the reaction is terminated when a predetermined stirring torque is reached. Then, the produced polymer was taken out. Further, the obtained polymer was subjected to solid phase polymerization at 260 ° C. and 1 Torr or less for 3 hours. [Η] of the obtained polymer (polyester resin (A1)) was 0.6 dl / g, and the melting point was 290 ° C.

(Preparation example 1 of ethylene / 1-butene copolymer)
[Preparation of catalyst solution]
0.63 mg of bis (1,3-dimethylcyclopentadienyl) zirconium dichloride is placed in a glass flask sufficiently purged with nitrogen, and 1.57 ml of a toluene solution of methylaminoxan (Al; 0.13 mmol / liter). And 2.43 ml of toluene were added to obtain a catalyst solution.

[Ethylene / 1-butene copolymerization]
912 ml of hexane and 320 ml of 1-butene were introduced into a 2 liter stainless steel autoclave sufficiently purged with nitrogen, and the temperature inside the system was raised to 80 ° C. Subsequently, 0.9 mmol of triisobutylaluminum and 2.0 ml of the catalyst solution prepared as described above (0.0005 mmol as Zr) were injected with ethylene to initiate polymerization. By continuously supplying ethylene, the total pressure was kept at 8.0 kg / cm 2 -G, and polymerization was carried out at 80 ° C. for 30 minutes.

A small amount of ethanol was introduced into the system to stop the polymerization, and then unreacted ethylene was purged. The obtained solution was poured into a large excess of methanol to precipitate a white solid. The white solid was collected by filtration and dried overnight under reduced pressure to obtain a white solid (ethylene / 1-butene copolymer (D6)).
Density = 0.862 g / cm ³
MFR (ASTM D1238 standard, 190 ° C .: 2160 g load) = 0.5 g / 10 min 1-butene structural unit content: 4 mol%

(Preparation example 2 of ethylene / 1-butene copolymer)
An ethylene butene copolymer (D5) having the following physical properties was obtained in the same manner as in Preparation Example 1 of ethylene / 1-butene copolymer, except that the amount of 1-butene used was changed to 290 ml. The results are also shown in Table 1.
Density = 0.870 g / cm ³
MFR (ASTM D1238 standard, 190 ° C .: 2160 g) = 0.5 g / 10 min

(Modification example 1 of ethylene / 1-butene copolymer)
To 100 parts by weight of the ethylene / 1-butene copolymer (D6) obtained above, 1.0 part by weight of maleic anhydride and peroxide [perhexine 25B, manufactured by NOF Corporation, trademark] 0.04 parts by weight And the resulting mixture was melt graft modified with a single screw extruder set at 230 ° C. to obtain a modified ethylene / 1-butene copolymer (D1) having the following physical properties.
The amount of maleic anhydride graft modification was 0.97% by weight. The intrinsic viscosity [η] measured in a 135 ° C. decalin solution was 1.98 dl / g. The results are also shown in Table 1.

(Modification example 2 of ethylene / 1-butene copolymer)
A modified ethylene / 1-butene copolymer (D2) was prepared in the same manner as in Modification Example 1 except that the ethylene / 1-butene copolymer (D5) was used instead of the ethylene / 1-butene copolymer (D6). ) The results are shown in Table 1.

(Modification example 3 of ethylene / 1-butene copolymer)
The above modification except that ethylene / 1-butene copolymer (D5), 0.5 parts by weight of maleic anhydride and 0.02 parts by weight of perhexine 25B were used instead of ethylene / 1-butene copolymer (D6). In the same manner as in Example 1, a modified ethylene / 1-butene copolymer (D3) was obtained. The results are shown in Table 1.

(Modification example 4 of ethylene / 1-butene copolymer)
A modified ethylene / 1-butene copolymer (D4) was obtained in the same manner as in Modification Example 1 except that 2.0 parts by weight of maleic anhydride and 0.08 parts by weight of perhexine 25B were used. The results are shown in Table 1.

Example 1
The polyester resin (A1), the following inorganic reinforcing materials (B1, B2), the following white pigment (C), and the olefin polymer (D1) were mixed at a ratio shown in Table 2 using a tumbler blender, and a twin-screw extruder The raw material was melt-kneaded at a cylinder temperature of 310 ° C. with TEX30α manufactured by Nippon Steel Works, Ltd., extruded into a strand shape, cooled in a water tank, and then taken up with a pelletizer and cut to obtain a pellet-shaped composition. (In other words, it showed good compounding properties.)
The results of evaluating the physical properties of the obtained polyester resin composition are also shown in Table 2.
Inorganic reinforcing material (B1): Glass fiber: Length 3 mm, aspect ratio 300 (Central Glass Co., Ltd. ECS03-615, silane compound treated product)
Inorganic filler (B2) Calcium carbonate whisker (length 25μm, aspect ratio 33)
White pigment (C): Titanium oxide (powder, average particle size 0.21 μm)

Examples 2-5, Comparative Examples 1-3
A polyester resin was prepared in the same manner as in Example 1 except that the conditions shown in Table 2 were used. The results are shown in Table 2.

[Comparative Example 4]
Although the method similar to the Example was performed by the compounding ratio shown in Table 2, the compound property in a twin-screw extruder was bad, and a favorable pellet could not be obtained.

上記の様に本発明の樹脂組成物は、従来に比して曲げ試験で代表される機械強度と靱性と反射率および反射率の経時保持性とのバランスが、従来の構成に比して高いことが分かる。故に、例えば、反射板用の材料として適している。特に好ましい例として、高い耐熱性と反射保持率を要求されるLED反射板用の材料として適している事を示唆している。

As described above, the resin composition of the present invention has a higher balance of mechanical strength, toughness, reflectivity, and reflectivity retention over time than that of a conventional structure, as represented by a bending test. I understand that. Therefore, it is suitable as a material for a reflector, for example. As a particularly preferred example, it is suggested that it is suitable as a material for an LED reflector plate that requires high heat resistance and reflection retention.

Claims (10)

30-80% by mass of a polyester resin (A) having a melting point or glass transition temperature of 250 ° C. or higher,
1-50% by mass of inorganic filler (B),
Olefin polymer (D) 0.1-15% by mass containing white pigment (C) 5-50% by mass and functional group structural unit 0.1-1.8%
And a polyester resin composition for a reflector.
(However, the total of A, B, C, and D is 100% by mass.)   The polyester resin (A) is an aliphatic having 30 to 100 mol% of dicarboxylic acid component units derived from terephthalic acid, 0 to 70 mol% of aromatic dicarboxylic acid component units other than terephthalic acid, and / or 4 to 20 carbon atoms. A dicarboxylic acid component unit (a-1) composed of 0 to 70 mol% of a dicarboxylic acid component unit, an alicyclic dialcohol component unit (a-3) having 4 to 20 carbon atoms and / or an aliphatic dialcohol component unit It is a polyester resin (A-1) containing (a-4), The polyester resin composition for reflectors of Claim 1 characterized by the above-mentioned. The polyester resin composition for a reflector according to claim 2, wherein the dialcohol component unit (a-3) contained in the polyester resin (A-1) has a cyclohexane skeleton.   The polyester resin composition for a reflector according to claim 1, wherein the inorganic filler (B) includes an inorganic filler having a carbonyl structure and an aspect ratio of 1 to 300.   The polyester resin composition for a reflector according to claim 1, wherein the inorganic filler (B) includes two or more inorganic fillers having different average lengths and aspect ratios.   The polyester resin composition for a reflector according to claim 4, wherein the inorganic filler (B) is a calcium carbonate whisker.   The polyester resin composition for a reflector according to claim 1, wherein the olefin polymer (D) contains a functional group selected from a carboxylic acid, an ester, an ether, an aldehyde, and a ketone.   The polyester resin composition for a reflector according to claim 7, wherein the olefin polymer (D) contains a maleic anhydride structural unit.   A reflector comprising the polyester resin composition of claim 1.   The reflector according to claim 9, wherein the reflector is a reflector for a light emitting diode element.