KR102158764B1 - Polyester resin, and polyester resin composition for surface-mount-type LED reflective plate which comprises same - Google Patents

Abstract

A polyester resin comprising a dicarboxylic acid component containing 50 mol% or more of aromatic dicarboxylic acid and a glycol component containing 15 mol% or more 4,4'-biphenyldimethanol, with a melting point of 280°C or more The resin is started. In addition, the polyester resin (A), titanium oxide (B), one or more reinforcing materials selected from the group consisting of fibrous reinforcing materials and needle-like reinforcing materials (C), and non-fibrous or non-acicular fillers (D), and polyester Ratio of 0.5 to 100 parts by mass, 0 to 100 parts by mass, and 0 to 50 parts by mass of titanium oxide (B), reinforcing material (C), and non-fibrous or non-acicular filler (D), respectively, to 100 parts by mass of resin (A) A polyester resin composition characterized in that it exists as is also disclosed. Such a polyester resin composition is suitable for use in a reflective plate for surface-mounted LEDs.

Description

Polyester resin, and polyester resin composition for surface-mount-type LED reflective plate using the same {Polyester resin, and polyester resin composition for surface-mount-type LED reflective plate which comprises same}

The present invention is excellent in moldability, fluidity, dimensional stability, low water absorption, soldering heat resistance, surface reflectance, etc., and furthermore, a polyester resin excellent in gold/tin soldering heat resistance, light resistance, and low water absorption, and a surface mount type using the same. It relates to a polyester resin composition suitable for use in a reflective plate for LEDs.

In recent years, LED (Light Emitting Diode) has been applied to lighting equipment, optical devices, mobile phones, backlights for liquid crystal displays, automobile console panels, signals, and display panels by utilizing features such as low power consumption, long life, high brightness, and possible miniaturization. In addition, in applications that value design and portability, surface mounting technology is used to realize lightness, thinness and reduction.

Surface-mounted LEDs are generally composed of light-emitting LED chips, lead wires, a reflector serving as a case, and encapsulating resin.Since the entire components mounted on the electronic board are joined with lead-free solder, each component has a solder reflow temperature of 260. It needs to be formed of a material that can withstand °C. As the melting point (melting peak temperature) of the material, 280°C or higher is required. In particular, for the reflecting plate, in addition to these heat resistance, surface reflectance for efficiently extracting light, and durability against heat or ultraviolet rays are required. From this point of view, various heat-resistant plastic materials such as ceramics, semi-aromatic polyamides, liquid crystal polymers, and thermosetting silicones are being studied. Among them, resins in which a high refractive filler such as titanium oxide is dispersed in semi-aromatic polyamide or polyester is mass-producible. It has a good balance of heat resistance and surface reflectance, so it is most commonly used. In recent years, with the generalization of LEDs, further improvement of workability and reliability is required for reflecting plates, and long-term heat coloring resistance and light resistance improvement are required.

As a polyester resin composition for LED reflectors, Patent Documents 1 to 5 are proposed, for example.

In Patent Documents 1 and 2, (a) i) 70 to 100 mol% of terephthalic acid residues; ii) 0 to 30 mol% of aromatic dicarboxylic acid residues having 20 or less carbon atoms; and iii) aliphatic dicarboxylic acid residues having 16 or less carbon atoms Dicarboxylic acid component containing 0-10 mol%; And (b) i) 2,2,4,4-tetramethyl-1,3-cyclobutanediol residue 1-99 mol%; And ii) 1,4 -A polyester resin consisting of a glycol component containing 1 to 99 mol% of residues of cyclohexanedimethanol (here, the total mol% of the dicarboxylic acid component is 100 mol%, and the total mol% of the glycol component is 100 mol%) Is disclosed, the mechanical properties tend to be good, but there are problems in moldability and light resistance.

In addition, in Patent Literature 3, (A) 2 to 50 parts by mass of phosphinate, (B) 2 to 50 parts by mass of phosphinic acid salt of which the anion portion is calcium or aluminum salt of phosphinic acid, (C) 0.5 to 30 parts by mass of titanium dioxide per 100 parts by mass of polyester resin And (D) 0.01 to 3 parts by mass of a polyolefin resin having a polar group. A flame-retardant polyester resin composition for a reflecting plate of a lighting device using a semiconductor light emitting device as a light source is disclosed, wherein the gold/tin soldering heat resistance, heat resistance, There is a problem with light resistance.

In addition, in Patent Document 4, 100 parts by mass of the wholly aromatic thermotropic liquid crystal polyester, 97 to 85% by mass of titanium oxide obtained by the manufacturing method including the roasting process, is 3 to 15% by mass of aluminum oxide (including hydrates) (100 parts by mass of both) Mass%), consisting of 8 to 42 parts by mass of titanium oxide particles, 25 to 50 parts by mass of glass fibers, and 0 to 8 parts by mass of other inorganic fillers, and at least of the glass fibers using a twin-screw kneader. There is disclosed a resin composition obtained through a melt-kneading process including a step of supplying a part at a position on the downstream side of 30% or more with respect to the entire length of the cylinder of a twin-screw kneader, but there are problems in heat resistance and weather resistance.

In addition, in Patent Document 5, as a dry unsaturated polyester resin composition comprising at least an unsaturated polyester resin, a polymerization initiator, an inorganic filler, a white pigment, a releasing agent and a reinforcing material, the unsaturated polyester resin is 14 to 40 mass with respect to the total amount of the composition. %, and the total amount of the inorganic filler and the white pigment blended is in the range of 44 to 74 mass% with respect to the total amount of the composition, and the ratio of the white pigment to the total amount of the inorganic filler and the white pigment blended There is disclosed an unsaturated polyester resin composition for an LED reflector, characterized in that it is 30% by mass or more, and wherein the unsaturated polyester resin is a mixture of an unsaturated alkyd resin and a crosslinking agent.

In addition, various polyamides have been used as reflectors for surface-mounted LEDs so far, but there are problems in heat coloring resistance, light resistance, and water absorption.

As described above, in the case of polyester and polyamide that have been proposed in the past, there is a situation in which they are used while having problems in heat coloring resistance, light resistance, and moldability.

In addition, in recent years, it has been actively developed for lighting applications. In the case of considering development for lighting applications, reduction in production cost, high performance, improvement in lifespan, and improvement in long-term reliability are further demanded. For this reason, a gold/tin process soldering with low deterioration and high thermal conductivity is used for bonding between the lead frame and the LED chip, rather than a conventional epoxy resin/silver paste. However, since a temperature of 280°C or more and less than 290°C is applied to the processing of gold/tin process soldering, a melting point of 290°C or more is required for the resin used to withstand the process. In addition, in order to prevent the occurrence of swelling (blister) on the surface of the molded article due to moisture in the resin even during the processing of soldering in the gold/tin process, the resin is required to have low water absorption.

As described above, there has not been reported a polyester resin composition sufficiently satisfying the properties usable for a reflective plate for surface-mounted LEDs.

Japanese Patent Publication No. 2008-544030 Japanese Patent Publication No. 2008-544031 Japanese Patent Publication No. 2010-270177 Japanese Patent Publication No. 2008-231368 Japanese Patent No. 4884699

The present invention was invented in view of the problems of the prior art, and its purpose is excellent in moldability, fluidity, dimensional stability, low water absorption, soldering heat resistance, surface reflectance, light resistance during injection molding, and further, long-term reliability. Polyester resin that achieves high melting point applicable to gold/tin process soldering process, low water absorption to reduce swelling of molded products due to moisture in the soldering process, and light resistance during outdoor use or long-term use in order to secure And a polyester resin composition for reflective plates for surface-mounted LEDs using the same.

In order to achieve the above object, the inventors of the present invention can advantageously perform injection molding or reflow soldering processes while satisfying the characteristics as a reflecting plate for LEDs, and furthermore, polyvinyl chloride having excellent solder heat resistance, low water absorption, and light resistance in gold/tin processes. As a result of careful examination of the composition of the ester, the present invention has been completed.

That is, the present invention has the following configurations (1) to (11).

(1) A polyester resin comprising a dicarboxylic acid component containing 50 mol% or more of an aromatic dicarboxylic acid and a glycol component containing 15 mol% or more 4,4'-biphenyldimethanol, with a melting point of 280°C. Polyester resin, characterized in that the above.

(2) characterized in that the aromatic dicarboxylic acid contains at least one dicarboxylic acid selected from the group consisting of 4,4'-biphenyldicarboxylic acid, terephthalic acid, and 2,6-naphthalenedicarboxylic acid. The polyester resin according to (1).

(3) Glycol components other than 4,4'-biphenyldimethanol constituting the polyester resin are ethylene glycol, 1,4-cyclohexanedimethanol, 1,3-propanediol, neopentyl glycol, and 1,4- The polyester resin according to (1) or (2), comprising at least one glycol selected from the group consisting of butanediol.

(4) The polyester resin according to any one of (1) to (3), wherein the difference between the melting point (Tm) of the polyester resin and the cooling crystallization temperature (Tc2) is 42°C or less.

(5) The polyester resin according to any one of (1) to (4), wherein the polyester resin has an acid value of 1 to 40 eq/t.

(6) At least one reinforcing material (C) selected from the group consisting of the polyester resin (A), titanium oxide (B), fibrous reinforcing material and needle-like reinforcing material according to any one of (1) to (5). , And non-fibrous or non-acicular filler (D), and titanium oxide (B), reinforcing material (C), and non-fibrous or non-acicular filler (D) per 100 parts by mass of polyester resin (A) are 0.5 A polyester resin composition for use in a reflector for a surface-mounted LED, characterized in that it is present in a ratio of ~100 parts by mass, 0~100 parts by mass, and 0~50 parts by mass.

(7) The polyester resin composition according to (6), wherein the non-fibrous or non-acicular filler (D) is talc, and contains 0.1 to 5 parts by mass of talc based on 100 parts by mass of the polyester resin (A). .

(8) The polyester resin composition according to (6) or (7), wherein the solder reflow heat resistance temperature is 260°C or higher.

(9) The polyester resin composition according to any one of (6) to (8), wherein the solder reflow heat resistance temperature is 280°C or higher.

(10) Among (6) to (9), characterized in that the peak melting temperature (Tm) of the polyester resin composition is 280°C or higher, and the difference between the peak melting temperature (Tm) and the crystallization temperature (Tc2) is 42°C or lower. The polyester resin composition according to any one.

(11) A reflecting plate for surface-mounted LEDs obtained by molding using the polyester resin composition according to any one of (6) to (10).

In addition to high heat resistance and low water absorption, the polyester resin of the present invention is excellent in processability such as moldability during injection molding and soldering heat resistance. Therefore, since the polyester resin composition of the present invention uses such a polyester resin, it is possible to industrially advantageously manufacture a surface-mounted reflector for LEDs that highly satisfies all necessary properties.

In addition, since the polyester resin composition of the present invention has a high melting point of 280°C or higher and excellent heat resistance, the polyester resin composition of the present invention can also be applied to the gold/tin process soldering process, and furthermore, since the aromatic ring concentration is high, heat resistance and toughness , It can exhibit features such as excellent light resistance and excellent adhesion to the encapsulant.

The polyester resin of the present invention has properties suitable as a material used for a molded article such as a film, a sheet, an injection molded article, and a molded article, particularly a reflective plate for a surface-mounted LED. Further, the polyester resin composition of the present invention is intended to be used for a reflective plate for surface-mounted LEDs. The surface mount type LED includes a chip LED type using a printed wiring board, a Gullwing type using a lead frame, a PLCC type, and the like. The polyester resin composition of the present invention can produce all of these reflectors by injection molding.

The polyester resin composition of the present invention includes at least one reinforcing material (C) selected from the group consisting of a polyester resin (A), titanium oxide (B), a fibrous reinforcing material and a needle-like reinforcing material, and a non-fibrous or non-acicular filler (D) It contains.

Polyester resin (A) is a dicarboxylic acid containing 50 mol% or more of aromatic dicarboxylic acid, which is blended to realize excellent UV resistance in addition to high melting point and low water absorption in order to impart high reliability. It consists of a component and a glycol component containing at least 15 mol% of 4,4'-biphenyldimethanol, and characterized in that the melting point is 280°C or higher. The melting point of the polyester resin (A) is preferably 290°C or higher, more preferably 300°C or higher, and still more preferably 310°C or higher. The upper limit of the melting point of the polyester resin (A) is not particularly limited, but is 340°C or less from the limit of the raw material components that can be used. The melting point is measured by the method described in the section of Examples.

As the aromatic dicarboxylic acid used as the dicarboxylic acid component of the polyester resin (A), 4,4'-biphenyldicarboxylic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, isophthalic acid, diphenoxy Citane dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 4,4'-diphenyl ketone dicarboxylic acid, and the like. Among the aromatic dicarboxylic acids, 4,4'-biphenyldicarboxylic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, or mixtures thereof are preferable from the viewpoints of polymerization, cost, and heat resistance. The aromatic dicarboxylic acid is 50 mol% or more of the dicarboxylic acid component from the viewpoint of heat resistance, preferably 60 mol% or more, more preferably 70 mol% or more, still more preferably 80 mol% or more, particularly preferably Is 90 mol% or more, and may be 100 mol%. In addition, examples of dicarboxylic acids other than aromatic dicarboxylic acids include aliphatic dicarboxylic acids such as adipic acid, sebacic acid, succinic acid, glutaric acid and dimer acid, hexahydroterephthalic acid, hexahydroisophthalic acid, and 1,2-cyclo Alicyclic dicarboxylic acids, such as hexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid, etc. are mentioned. In addition, polyhydric carboxylic acids such as oxy acids such as p-oxybenzoic acid and oxycaproic acid, trimellitic acid, pyromellitic acid, benzophenone tetracarboxylic acid, biphenyl sulfone tetracarboxylic acid, and biphenyl tetracarboxylic acid, and It doesn't matter if you use his anhydride together.

In addition, 4,4'-biphenyldimethanol used as the glycol component of the polyester resin (A) needs to contain 15 mol% or more of the total glycol component, and 4,4'-biphenyldimethanol is preferably It is 50 mol% or more, more preferably 60 mol% or more, still more preferably 65 mol% or more, and most preferably 70 mol% or more. 4,4'-biphenyldimethanol is added to increase moldability, solder heat resistance, and light resistance, and when the ratio is less than the above value, these properties tend to decrease. As glycol components other than 4,4'-biphenyldimethanol, for example, ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butylene glycol, 1,2-butylene glycol , 1,3-butylene glycol, 2,3-butylene glycol, 1,5-pentanediol, 1,6-hexanediol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4 -Cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 1,4-cyclohexanediethanol, 3-methyl-1,5-pentane Diol, 2-methyl-1,5-pentanediol, 2-methyl-1,3-propanediol, 2-ethyl-1,3-propanediol, neopentyl glycol, 2-ethyl-2-methyl-1,3 -Propanediol, 2,2-diethyl-1,3-propanediol, 2-methyl-2-n-butyl-1,3-propanediol, 2-n-butyl-2-ethyl-1,3-propane Diol, 2,2-di-n-butyl-1,3-propanediol, 2-ethyl-2-n-hexyl-1,3-propanediol, 2,2-di-n-hexyl-1,3- Aliphatic glycols such as propanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, triethylene glycol, polyethylene glycol, polytrimethylene glycol, polytetramethylene glycol, and polypropylene glycol, Hydroquinone, 4,4'-dihydroxybisphenol, 1,4-bis(β-hydroxyethoxy)benzene, 1,4-bis(β-hydroxyethoxyphenyl)sulfone, bis(p-hydroxyphenyl) ) Ether, bis(p-hydroxyphenyl)sulfone, bis(p-hydroxyphenyl)methane, 1,2-bis(p-hydroxyphenyl)ethane, bisphenol A, alkylene oxide adducts of bisphenol A, etc. Aromatic glycols and the like. Among the glycols, one or two selected from ethylene glycol, 1,4-cyclohexanedimethanol, 1,3-propanediol, and neopentyl glycol 1,4-butanediol from heat resistance, polymerization, moldability, cost, etc. Mixtures of more than one species are preferred. More preferably, it is one type or a mixture of two or more selected from ethylene glycol and 1,4-butanediol. In addition, when ethylene glycol is used as the glycol component, diethylene glycol may be produced by-products during the production of the polyester resin (A) to become a copolymerization component. In this case, the diethylene glycol to be produced varies depending on the manufacturing conditions, but is about 1 to 5 mol% based on the ethylene glycol added to the polyester resin. In addition, polyhydric polyols such as trimethylolethane, trimethylolpropane, glycerin, and pentaerythritol may be used in combination.

When the total component is 200 mol%, the polyester resin is preferably 160 mol% or more, more preferably 180 mol% or more, still more preferably 190 mol%, in terms of the total of the dicarboxylic acid component and the glycol component. % Or more, and even if it is 200 mol%. However, in either case, the dicarboxylic acid component does not exceed 100 mol% and the glycol component does not exceed 100 mol%.

Further, metal salts such as 5-sulfoisophthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid, and 5-[4-sulfophenoxy]isophthalic acid, or 2-sulfo-1,4-butanediol, 2, Even if a dicarboxylic acid or diol containing a sulfonic acid metal base such as a metal salt such as 5-dimethyl-3-sulfo-2,5-hexanediol is used in the range of 20 mol% or less of the total acid component or the total diol component do.

The catalyst used when producing the polyester resin (A) is not particularly limited, but at least one compound selected from compounds of Ge, Ti, Sb, Al, Mn, or Mg is preferably used. These compounds are added to the reaction system as powder, aqueous solution, ethylene glycol solution, ethylene glycol slurry, or the like.

In addition, as a stabilizer for the resin, the group consisting of phosphoric acid, phosphoric acid esters such as polyphosphoric acid or trimethylphosphate, phosphonic acid compounds, phosphinic acid compounds, phosphine oxide compounds, aphosphonic acid compounds, aphosphinic acid compounds, and phosphine compounds It is preferable to use at least one phosphorus compound selected from.

The acid value of the polyester resin (A) is preferably 1 to 40 eq/ton. When the acid value exceeds 40 eq/ton, the light resistance tends to decrease. In addition, when the acid value is less than 1 eq/ton, the polycondensation reactivity tends to decrease, resulting in poor productivity.

The polyester resin (A) of the present invention has a melting point (Tm) of 280°C or higher in DSC measurement, preferably 290°C or higher, more preferably 300°C or higher, particularly preferably 310°C or higher, most preferably It is above 320℃. On the other hand, it is preferable that the upper limit of the polyester resin melting point (Tm) of this invention is 340 degreeC or less. If the Tm exceeds 340°C, the processing temperature required when injection molding the composition using the polyester resin (A) of the present invention is very high, so that the polyester resin is decomposed during processing, resulting in the desired physical properties and appearance. It may not be obtained. Conversely, when Tm is less than the above lower limit, the crystallization rate may be slow, making it difficult to form all of them, and further, there is a concern that soldering heat resistance may be lowered. If Tm is 310°C or higher, it is preferable because it satisfies the reflow soldering heat resistance of 280°C and can be applied to the gold/tin process soldering process.

In addition, in the polyester resin (A) of the present invention, in DSC measurement, the difference between the melting point (Tm) and the crystallization temperature (Tc2) at lower temperature is preferably 42°C or less, more preferably 40°C or less, still more preferably 35°C or less. , Most preferably 30°C or less. The temperature-fall crystallization temperature (Tc2) is a temperature at which crystallization begins when the temperature is lowered at a temperature 10°C or higher than the melting point in DSC measurement. The melting point (Tm) and the cooling crystallization temperature (Tc2) are measured by the method described in the section of Examples. When the difference between the melting point (Tm) and the cooling crystallization temperature (Tc2) is less than or equal to the above temperature, crystallization proceeds easily, and dimensional stability and physical properties can be sufficiently exhibited. On the other hand, when the difference between the melting point (Tm) and the crystallization temperature (Tc2) exceeds the above temperature, the reflective plate for LEDs is molded in a short cycle of injection molding, so crystallization may not proceed sufficiently, such as insufficient mold release, etc. Since forming difficulty is caused or crystallization is not sufficiently completed, deformation or shrinkage of crystals occurs during heating in a post-process, resulting in a problem of peeling from the encapsulant or lead frame, resulting in insufficient reliability.

The intrinsic viscosity (IV) of the polyester resin (A) is preferably 0.10 to 0.70 dl/g, more preferably 0.20 to 0.65 dl/g, and still more preferably 0.25 to 0.60 dl/g.

The polyester resin (A) is present in the polyester resin composition of the present invention in a ratio of preferably 25 to 90 mass%, more preferably 40 to 75 mass%. When the ratio of the polyester resin (A) is less than the above lower limit, the mechanical strength is lowered, and when it exceeds the above upper limit, the amount of titanium oxide (B) or the reinforcing material (C) is insufficient, making it difficult to obtain the desired effect.

Titanium oxide (B) is compounded to increase the surface reflectance of the reflector. For example, rutile-type and anatase-type titanium dioxide (TiO ₂ ), titanium monoxide (TiO), titanium trioxide produced by the sulfuric acid method or chlorine method ( Ti ₂ O ₃ ), and the like, in particular, rutile type titanium dioxide (TiO ₂ ) is preferably used. The average particle diameter of titanium oxide (B) is generally in the range of 0.05 to 2.0 µm, preferably 0.15 to 0.5 µm, and may be used alone or in combination of titanium oxides having different particle diameters. The titanium oxide component concentration is 90% by mass or more, preferably 95% by mass or more, and more preferably 97% by mass or more. In addition, titanium oxide (B) may be a metal oxide such as silica, alumina, zinc oxide, or zirconia, a coupling agent, an organic acid, an organic polyhydric alcohol, or a siloxane treated with a surface.

The ratio of the titanium oxide (B) is 0.5 to 100 parts by mass, preferably 10 to 80 parts by mass per 100 parts by mass of the polyester resin (A). When the ratio of titanium oxide (B) is less than the above lower limit, the surface reflectance decreases, and when it exceeds the above upper limit, there is a fear that the molding processability may decrease, such as a significant decrease in physical properties and lower fluidity.

The reinforcing material (C) is blended in order to improve the moldability of the polyester resin composition and the strength of the molded article, and at least one selected from fibrous reinforcing materials and needle-like reinforcing materials is used. Examples of the fibrous reinforcing material include glass fibers, carbon fibers, boron fibers, ceramic fibers, and metal fibers, and examples of the acicular reinforcing materials include potassium titanate whiskers, aluminum borate whiskers, zinc oxide whiskers, calcium carbonate whiskers, Magnesium sulfate whisker, wollastonite, etc. are mentioned. As the glass fiber, it is possible to use chopped strands or continuous filament fibers having a length of 0.1 mm to 100 mm. As the cross-sectional shape of the glass fiber, glass fibers having a circular cross section and a non-circular cross section can be used. The diameter of the circular cross-section glass fiber is preferably 20 µm or less, more preferably 15 µm or less, and still more preferably 10 µm or less. In addition, glass fibers having a non-circular cross section are preferred from the viewpoint of physical properties and fluidity. The glass fibers having a non-circular cross section include those having an approximately elliptical shape, an approximately oblong shape, and an approximately cocoon shape in a cross section perpendicular to the longitudinal direction of the fiber, and a flatness of 1.5 to 8 is preferable. Here, the flatness is the ratio of the long/shorter diameter when the length of the long side of this rectangle is the long side and the length of the short side is the short side, assuming a rectangle with the smallest area circumscribed to the cross section perpendicular to the longitudinal direction of the glass fiber. to be. The thickness of the glass fiber is not particularly limited, but the short diameter is about 1 to 20 µm and the long diameter is about 2 to 100 µm. In addition, the glass fibers can be preferably used in the shape of a chopped strand cut into a fiber bundle and cut to about 1 to 20 mm in length. Furthermore, in order to increase the surface reflectance of the polyester resin composition, the refractive index difference with the polyester resin is preferably large, and therefore, it is preferable to use the one in which the refractive index is increased by changing the glass composition or surface treatment.

The ratio of the reinforcing material (C) is 0 to 100 parts by mass, preferably 5 to 100 parts by mass, and more preferably 10 to 60 parts by mass with respect to 100 parts by mass of the polyester resin (A). Although the reinforcing material (C) is not an essential component, when the ratio is 5 parts by mass or more, the mechanical strength of the molded article is improved, and it is preferable. When the ratio of the reinforcing material (C) exceeds the above upper limit, the surface reflectance and molding processability tend to decrease.

Examples of the non-fibrous or non-acicular filler (D) include reinforcing fillers, conductive fillers, magnetic fillers, flame-retardant fillers, thermally conductive fillers, fillers for suppressing heat yellowing, and the like, for each purpose.Specifically, glass beads, glass flakes, and glass balloons , Silica, talc, kaolin, mica, alumina, hydrotalcite, montmorillonite, graphite, carbon nanotubes, fullerene, indium oxide, tin oxide, iron oxide, magnesium oxide, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, red phosphorus, calcium carbonate, acetic acid Magnesium, lead zirconate titanate, barium titanate, aluminum nitride, boron nitride, zinc borate, barium sulfate and non-needle wollastonite, potassium titanate, aluminum borate, magnesium sulfate, zinc oxide, calcium carbonate, and the like. These fillers may not be used alone, but may be used in combination of several types. Among these, talc is preferable because it has an effect of accelerating crystallization and improves moldability. The amount of the filler added may be selected in an optimal amount.It is possible to add up to 50 parts by mass per 100 parts by mass of the polyester resin (A), but 0.1 to 20 parts by mass is preferable from the viewpoint of the mechanical strength of the resin composition. Preferably it is 1-10 mass parts. When talc is used, 0.1 to 5 parts by mass is preferred, and more preferably 0.5 to 3 parts by mass per 100 parts by mass of the polyester resin (A). In addition, the fibrous reinforcing material and filler are preferably those treated with an organic treatment or a coupling agent in order to improve the affinity with the polyester resin, or used in combination with a coupling agent during melt synthesis, and as the coupling agent, a silane coupling agent, Any of a titanate-based coupling agent and an aluminum-based coupling agent may be used. Among them, an aminosilane coupling agent and an epoxysilane coupling agent are particularly preferred.

In the polyester resin composition of the present invention, various additives of the conventional polyester resin composition for an LED reflector can be used. Examples of the additives include stabilizers, impact modifiers, flame retardants, mold release agents, sliding properties modifiers, colorants, optical brighteners, plasticizers, nucleating agents, thermoplastic resins other than polyester, and the like.

As a stabilizer for the resin composition, organic antioxidants such as hindered phenolic antioxidants, sulfur antioxidants, phosphorus antioxidants, heat stabilizers, hindered amines, light stabilizers such as benzophenone, imidazole, UV absorbers, metal inert A chemical agent, a copper compound, etc. are mentioned. Copper compounds include cuprous chloride, cuprous bromide, cuprous iodide, cupric chloride, cupric bromide, cupric iodide, cupric phosphate, cupric pyrophosphate, copper sulfide, copper nitrate, Copper salts of organic carboxylic acids, such as copper acetate, etc. can be used. In addition, it is preferable to contain an alkali metal halide compound as a constituent component other than the copper compound, and as the alkali metal halide compound, lithium chloride, lithium bromide, lithium iodide, sodium fluoride, sodium chloride, sodium bromide, sodium iodide, potassium fluoride, potassium chloride, bromide Potassium, potassium iodide, etc. are mentioned. These additives may not be used alone, but may be used in combination of several types. The amount of the stabilizer added may be selected in an optimal amount, but it is possible to add up to 5 parts by mass per 100 parts by mass of the polyester resin (A).

You may add a thermoplastic resin different from the polyester resin (A) to the polyester resin composition of this invention. For example, polyamide (PA), polyphenylene sulfide (PPS), liquid crystal polymer (LCP), polytetrafluoroethylene (PTFE), fluororesin, aramid resin, polyetheretherketone (PEEK), polyetherketone ( PEK), polyetherimide (PEI), thermoplastic polyimide, polyamideimide (PAI), polyether ketone ketone (PEKK), polyphenylene ether (PPE), polyethersulfone (PES), polysulfone (PSU), Polyarylate (PAR), polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polycarbonate (PC), polyoxymethylene (POM), polypropylene (PP), polyethylene (PE), Polymethylpentene (TPX), polystyrene (PS), polymethyl methacrylate, acrylonitrile-styrene copolymer (AS), and acrylonitrile-butadiene-styrene copolymer (ABS). These thermoplastic resins may be blended in a molten state by melt-kneading, but may be dispersed in the polyester resin composition of the present invention by making the thermoplastic resin fibrous or particulate. The amount of the thermoplastic resin to be added may be selected in an optimal amount, but it is possible to add up to 50 parts by mass per 100 parts by mass of the polyester resin (A).

Impact modifiers include ethylene-propylene rubber (EPM), ethylene-propylene-diene rubber (EPDM), ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, ethylene-methacrylic acid copolymer, and ethylene-methacrylic acid ester copolymer. , Polyolefin resins such as ethylene vinyl acetate copolymer, styrene-butadiene-styrene block copolymer (SBS), styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-isoprene-styrene copolymer (SIS), A polyester block copolymer in which a vinyl polymer resin such as an acrylic acid ester copolymer, polybutylene terephthalate or polybutylene naphthalate as a hard segment, and polytetramethylene glycol, polycaprolactone, or polycarbonate diol as a soft segment, Nylon elastomer, urethane elastomer, acrylic elastomer, silicone rubber, fluorine-based rubber, and polymer particles having a core-shell structure composed of two different types of polymers. The amount of the impact modifier added may be selected from an optimal amount, but it is possible to add up to 30 parts by mass per 100 parts by mass of the polyester resin (A).

When adding a thermoplastic resin other than the polyester resin (A) and an impact improving agent to the polyester resin composition of the present invention, it is preferable that a reactive group capable of reacting with the polyester is copolymerized, and the reactive group is a terminal group of the polyester resin. It is a group capable of reacting with a hydroxyl group and/or a carboxyl group. Specifically, an acid anhydride group, an epoxy group, an oxazoline group, an amino group, an isocyanate group, and the like are exemplified. Among them, an epoxy group and an isocyanate group are the most excellent in reactivity. There is also a report that the thermoplastic resin having a reactive group reacting with the polyester resin is finely dispersed in the polyester, so that the distance between the particles is shortened and the impact resistance is greatly improved.

As a flame retardant, a combination of a halogen-based flame retardant and a flame retardant aid is good, and as a halogen-based flame retardant, brominated polystyrene, brominated polyphenylene ether, brominated bisphenol type epoxy polymer, brominated styrene maleic anhydride polymer, brominated epoxy resin, brominated phenoxy resin, deca Bromodiphenyl ether, decabromobiphenyl, brominated polycarbonate, perchlorocyclopentadecane, and brominated crosslinked aromatic polymers are preferred, and as flame retardant aids, antimony trioxide, antimony pentoxide, sodium antimonate, zinc stannate, zinc borate, montmorillonite, etc. Layered silicates, fluorine-based polymers, and silicones. Among them, from the viewpoint of thermal stability, a combination of dibrompolystyrene as a halogen-based flame retardant and any one of antimony trioxide, sodium antimonate, and zinc stannate is preferable as a flame retardant auxiliary. Further, examples of the non-halogen flame retardant include melamine cyanurate, red phosphorus, a metal salt of phosphinic acid, and a nitrogen-containing phosphoric acid compound. In particular, a combination of a phosphinic acid metal salt and a nitrogen-containing phosphoric acid-based compound is preferred, and examples of the nitrogen-containing phosphoric acid-based compound include melamine or a reaction product of a condensation product of melamine such as melamine, melam, melon and polyphosphoric acid, or a mixture thereof. As other flame retardants and flame retardant auxiliary agents, it is preferable to add a hydrotalcite compound or an alkali compound to prevent corrosion of metals such as molds when these flame retardants are used. The amount of the flame retardant to be added may be selected from an optimum amount, but it is possible to add up to 50 parts by mass per 100 parts by mass of the polyester resin (A).

Examples of the mold release agent include long-chain fatty acids or esters or metal salts thereof, amide compounds, polyethylene wax, silicones, and polyethylene oxides. As the long-chain fatty acid, particularly preferably having 12 or more carbon atoms, for example, stearic acid, 12-hydroxystearic acid, behenic acid, montanic acid, and the like, partially or all carboxylic acids are esterified with monoglycol or polyglycol. Alternatively, a metal salt may be formed. Examples of the amide compound include ethylene bisterephthalamide and methylene bis stearylamide. These release agents may be used alone or as a mixture. The amount of the release agent to be added may be selected from an optimum amount, but it is possible to add up to 5 parts by mass per 100 parts by mass of the polyester resin (A).

Since the polyester resin composition of the present invention contains the polyester resin (A) as described above, the melting peak temperature (Tm) in DSC measurement is preferably 280°C or higher, more preferably 290°C or higher, More preferably, it is 300°C or more, particularly preferably 310°C or more, and most preferably 320°C or more. On the other hand, it is preferable that the upper limit of Tm of the polyester resin composition of this invention is 340 degreeC or less.

In addition, since the polyester resin composition of the present invention contains the polyester resin (A) as described above, it is preferable that the difference between the melting peak temperature (Tm) and the cooling crystallization temperature (Tc2) in DSC measurement is 42°C or less. , More preferably 40°C or less, more preferably 35°C or less, and still more preferably 30°C or less.

In addition to the high melting point and moldability, the polyester resin (A) has excellent balance of low water absorption and fluidity, and further has excellent light resistance. For this reason, the polyester resin composition of the present invention obtained from such a polyester resin (A) is capable of high-melting and high-cycle molding in addition to having a high melting point of 280°C or higher and low water absorption in molding a reflective plate of a surface-mounted LED.

The polyester resin composition of the present invention can be produced by blending each of the aforementioned constituent components by a conventionally known method. For example, each component is added during the polycondensation reaction of polyester resin (A), dry blended polyester resin (A) and other components, or melt-kneaded each component using a twin screw type extruder How to do it.

Example

The present invention will be described in more detail by examples below, but the present invention is not limited to these examples. In addition, the measured values described in the examples were measured by the following method.

(1) Ultimate viscosity of polyester resin (IV)

It was calculated|required from the solution viscosity at 30 degreeC in a 1,1,2,2-tetrachloroethane/phenol (2:3 weight ratio) mixed solvent.

(2) acid value

After dissolving 0.1 g of polyester resin by heating in 10 ml of benzyl alcohol, it was titrated and calculated using a 0.1 N NaOH solution of methanol/benzyl alcohol (1/9 volume ratio).

(3) Polyester resin melting point (Tm), melting peak temperature (Tm) of resin composition, cooling crystallization temperature (Tc2)

It was measured with a differential thermal analyzer (DSC) manufactured by Seiko Electronics Co., Ltd., RDC-220. After the temperature was raised at a temperature increase rate of 20°C/min and maintained at 330°C for 3 minutes, the temperature was lowered from 330°C to 130°C at 10°C/min. In addition, in the case of not melting at 330°C, the temperature was lowered from 340°C to 130°C at 10°C/min after holding at 340°C for 3 minutes. The peak temperature of the melting peak observed at the time of heating was taken as the melting point (Tm), and the peak temperature of the crystallization peak observed at the time of cooling was taken as the cooling crystallization temperature (Tc2).

(4) Formability and dimensional stability

Using the Toshiba Machine-made injection molding machine EC-100, the cylinder temperature was set at the melting point of the resin +20℃, and the mold temperature was set at 125℃, and a mold for flat plate production with a film gate of 100 mm in length, 100 mm in width and 1 mm in thickness was prepared. Injection molding was performed. Molding was performed at an injection speed of 50 mm/sec, a holding pressure of 30 MPa, an injection time of 10 seconds, and a cooling time of 10 seconds, and moldability evaluation was performed according to the following criteria.

○: Molded products are obtained without problems.

△: Sometimes the spool remains in the mold.

×: The molded product is attached to the mold or deformed due to insufficient releasability.

Further, in order to evaluate the dimensional stability of the obtained molded article, the molded article was heated at 180°C for 1 hour. The dimensions in the direction perpendicular to the flow direction before and after heating were measured, and the amount of dimensional change was calculated as follows.

Dimensional stability evaluation was performed based on the following criteria.

○: Dimensional change is less than 0.2%

×: dimensional change of 0.2% or more

(5) Soldering heat resistance

Using the Toshiba Machine-made injection molding machine EC-100, the cylinder temperature was set at the melting point of the resin +20℃ and the mold temperature was set at 140℃, and a test piece for UL combustion test of 127 mm in length, 12.6 mm in width and 0.8 mm in thickness was injection molded. A test piece was prepared. The test piece was allowed to stand for 72 hours in an atmosphere of 85°C and 85% RH (relative humidity). The test piece was heated in an air reflow furnace (AIS-20-82C manufactured by Atech), heated from room temperature to 150°C over 60 seconds, preheated, and then preheated to 190°C at a rate of 0.5°C/min. . Thereafter, the temperature was raised to a predetermined set temperature at a rate of 100° C./min, and after holding at the predetermined temperature for 10 seconds, cooling was performed. The set temperature was increased from 240°C to 5°C intervals, and the highest set temperature at which swelling or deformation of the surface did not occur was used as the reflow heat resistance temperature, and the soldering heat resistance was evaluated based on the following criteria.

◎: Reflow heat resistance temperature of 280℃ or higher

○: Reflow heat resistance temperature is more than 260℃ and less than 280℃

×: Reflow heat resistance temperature is less than 260℃

(6) diffuse reflectance

Using the Toshiba Machine-made injection molding machine EC-100, the cylinder temperature was set at the melting point of the resin +20℃ and the mold temperature was set at 140℃, and a flat plate having a length of 100 mm, a width of 100 mm, and a thickness of 2 mm was injection-molded to prepare a test piece for evaluation. Was produced. Using this test piece, an integrating sphere manufactured by the company was installed in a magnetic spectrophotometer "U3500" manufactured by Hitachi, and the reflectance at a wavelength of 350 nm to 800 nm was measured. For the comparison of reflectance, the diffuse reflectance at a wavelength of 460 nm was determined. Barium sulfate was used as a reference.

(7) Saturated water absorption rate

Using the Toshiba Machine-made injection molding machine EC-100, the cylinder temperature was set to the melting point of the resin +20℃, and the mold temperature was set to 140℃, and a flat plate of 100 mm in length, 100 mm in width, and 1 mm in thickness was injection-molded to prepare a test piece for evaluation. Was produced. This test piece was immersed in hot water at 80° C. for 50 hours, and the saturated water absorption rate was calculated from the weight at the time of saturated water absorption and at the time of drying by the following equation.

(8) Liquidity

Using the Toshiba Machine-made injection molding machine EC-100, the cylinder temperature is set to 330℃ and the mold temperature is set to 120℃, the injection pressure setpoint is 40%, the injection speed setpoint is 40%, the weighing 35 mm, the injection time 6 seconds, cooling Under the conditions of a time of 10 seconds, a test piece for evaluation was prepared by injection molding with a flow length measuring mold having a width of 1 mm and a thickness of 0.5 mm. As a flowability evaluation, the flow length (mm) of this test piece was measured.

(9) silicone adhesion

Using the Toshiba Machine-made injection molding machine EC-100, the cylinder temperature was set at the melting point of the resin +20℃ and the mold temperature was set at 140℃, and a flat plate having a length of 100 mm, a width of 100 mm, and a thickness of 2 mm was injection-molded to prepare a test piece for evaluation. Was produced. One side of this test piece was coated with a silicone encapsulant (made by Shin-Etsu Silicon, ASP-1110, encapsulant hardness D60) to a coating thickness of about 100 µm, followed by preheating at 100°C for 1 hour and then 150°C×4 Curing treatment was performed for a period of time to form a sealing material film on one side of the test piece.

Next, the sealing material film on the test piece was subjected to a checkered test based on JIS K5400 (1 mm wide crosscut 100 checkered) to evaluate the adhesion according to the following criteria.

○: 10 or less of the number of peeled checkers

×: There is peeling at the time of forming checkered eyes before peeling test

(10) light resistance

Using the Toshiba Machine-made injection molding machine EC-100, the cylinder temperature was set at the melting point of the resin +20℃ and the mold temperature was set at 140℃, and a flat plate having a length of 100 mm, a width of 100 mm, and a thickness of 2 mm was injection-molded to prepare a test piece for evaluation. Was produced. About this test piece, UV irradiation was performed with the illuminance of 50 mW/cm<2> in an environment of 63 degreeC and 50%RH using an ultra-accelerated weathering tester "I Super UV Tester SUV-F11". The light reflectance of the test piece at a wavelength of 460 nm was measured before irradiation and 60 hours after irradiation. Light resistance was evaluated based on the following criteria as the retention rate of the light reflectance of the test piece after irradiation with respect to the light reflectance of the test piece before irradiation.

◎: 95% or more retention rate

○: Retention rate less than 95%-more than 90%

△: Retention rate less than 90%-85% or more

×: Less than 85% retention rate

(11) Heat yellowing resistance

Using the Toshiba Machine-made injection molding machine EC-100, the cylinder temperature was set at the melting point of the resin +20℃ and the mold temperature was set at 140℃, and a flat plate having a length of 100 mm, a width of 100 mm, and a thickness of 2 mm was injection-molded to prepare a test piece for evaluation. Was produced. Using this test piece, it was treated in a hot air dryer at 150° C. for 2 hours to visually check the yellowing property and evaluated according to the following criteria.

○: No change

△: slightly yellowed

×: yellowed

(Example 1)

High purity dimethyl terephthalic acid 3,880 g, 4,4'-biphenyl dimethanol 2,782 g, ethylene glycol 1,922 g, manganese acetate 2 g, germanium dioxide 0.86 g were added to a 20 liter stainless steel autoclave equipped with a stirrer. The pressure of the reaction system was gradually lowered while raising the temperature to 300°C over a period of 13.3 Pa (0.1 Torr), and a polycondensation reaction was further performed at 310°C and 13.3 Pa. Following pressure relief, the unpressurized resin was discharged into water in a strand shape, cooled, and cut with a cutter to obtain cylindrical pellets having a length of about 3 mm and a diameter of about 2 mm. The intrinsic viscosity of the obtained polyester was 0.60 dl/g, and the resin composition was 100 mol% of terephthalic acid, 65.0 mol% of 4,4'-biphenyldimethanol, 34.5 mol% of ethylene glycol, and the resin composition by ¹ H-NMR measurement. Ethylene glycol was 0.5 mol%. Table 1 shows the composition and characteristic values of the obtained polyester resin.

(Examples 2 to 4)

Each polyester resin was obtained in the same manner as in the polymerization of the polyester resin of Example 1 except for changing the amount or type of the raw material to be used. The composition and characteristic values of each obtained polyester resin are shown in Table 1. In addition, diethylene glycol is a byproduct of ethylene glycol condensation.

(Example 5)

High purity dimethyl terephthalic acid 3,880 g, 4,4'-biphenyl dimethanol 2,782 g, ethylene glycol 1,922 g, manganese acetate 2 g, germanium dioxide 0.86 g were added to a 20 liter stainless steel autoclave equipped with a stirrer.After transesterification, high purity terephthalic acid was added. 8 g was added and the pressure of the reaction system was gradually lowered while raising the temperature to 300°C over 60 minutes to obtain 13.3 Pa (0.1 Torr), and a polycondensation reaction was further carried out at 310°C and 13.3 Pa. Following the release pressure, the unpressed resin was discharged into water in a strand shape, cooled, and cut with a cutter to obtain cylindrical pellets having a length of about 3 mm and a diameter of about 2 mm. The intrinsic viscosity of the obtained polyester was 0.60 dl/g, and the resin composition was 100 mol% of terephthalic acid, 65.0 mol% of 4,4'-biphenyldimethanol, 34.5 mol% of ethylene glycol, and the resin composition by ¹ H-NMR measurement. Ethylene glycol was 0.5 mol%. The composition and characteristic values of the obtained polyester resin are shown in Table 1.

(Comparative Example 1)

In a 20-liter stainless steel autoclave equipped with a stirrer, high-purity terephthalic acid and twice the molar amount of ethylene glycol were added, and triethylamine was added in an amount of 0.3 mol% based on the acid component, and water was distilled out of the system at 250°C under a pressure of 0.25 MPa. While performing the esterification reaction, a mixture of bis(2-hydroxyethyl) terephthalate and oligomer having an esterification rate of about 95% (hereinafter referred to as a BHET mixture) was obtained. Germanium dioxide (100 ppm as Ge) was added as a polymerization catalyst to this BHET mixture, followed by stirring for 10 minutes at 250°C under a nitrogen atmosphere at normal pressure. Thereafter, the pressure of the reaction system was gradually lowered while raising the temperature to 280° C. over 60 minutes to obtain 13.3 Pa (0.1 Torr), and a polycondensation reaction was further carried out at 280° C. and 13.3 Pa. Following the release pressure, the unpressed resin was discharged into water in a strand shape, cooled, and cut with a cutter to obtain cylindrical pellets having a length of about 3 mm and a diameter of about 2 mm. The intrinsic viscosity of the obtained polyester was 0.61 dl/g, and the resin composition was 100 mol% of terephthalic acid, 98.0 mol% of ethylene glycol, and 2.0 mol% of diethylene glycol by ¹ H-NMR measurement. The composition and characteristic values of the obtained polyester resin are shown in Table 2.

(Comparative Examples 2-4)

Each polyester resin was obtained in the same manner as in the polymerization of the polyester resin of Comparative Example 1 except for changing the kind of the raw material to be used. The composition and characteristic values of each obtained polyester resin are shown in Table 2.

(Comparative Example 5: Polyamide resin)

Terephthalic acid 3,272.9 g (19.70 mol), 1,9-nonandiamine 2,849.2 g (18.0 mol), 2-methyl-1,8-octanediamine 316.58 g (2.0 mol), benzoic acid 73.27 g (0.60 mol), sodium hypophosphite monobasic Hydrate 6.5 g (0.1% by weight based on the raw material) and 6 liters of distilled water were placed in an autoclave having an inner volume of 20 liters, followed by nitrogen substitution. After stirring at 100° C. for 30 minutes, the internal temperature was raised to 210° C. over 2 hours. At this time, the autoclave was boosted to 22 kg/cm 2. After continuing the reaction for 1 hour as it is, the temperature was raised to 230° C., and then the temperature was maintained at 230° C. for 2 hours, and the water vapor was gradually removed to react while maintaining the pressure at 22 kg/cm 2. Next, the pressure was lowered to 10 kg/cm 2 over 30 minutes and reacted for an additional 1 hour to obtain a prepolymer having an intrinsic viscosity [η] of 0.25 dl/g. This was dried for 12 hours at 100° C. under reduced pressure, and pulverized to a size of 2 mm or less. This was subjected to solid phase polymerization at 230°C and 0.1 mmHg for 10 hours to obtain a white polyamide resin having a melting point of 310°C, an intrinsic viscosity [η] of 1.33 dl/g, and a terminal sealing ratio of 90%. The composition and characteristic values of the obtained polyamide resin are shown in Table 2.

(Examples 6 to 13, Comparative Examples 6 to 10)

Examples 6 to 13 were melt-kneaded at the melting point of polyester resin (A) or polyamide resin at +15°C using a twin-screw extruder STS-35 manufactured by Coperion Co., Ltd. with the components and mass ratios shown in Tables 3 and 4 , Resin compositions of Comparative Examples 6-10 were obtained. In Tables 3 and 4, the details of materials to be used other than the polyester resin (A) are as follows.

Titanium oxide (B): Ishihara Sangyo Co., Ltd. Taipei CR-60, rutile type TiO ₂ , average particle diameter 0.2 µm

Reinforcing material (C): Glass fiber (manufactured by Nittobo, CS-3J-324), needle-shaped wallast (manufactured by NYCO, NYGLOS8)

Filling material (D): Talc (Hayashi Kasei Co., Ltd. micron white 5000A)

Mold release agent: Magnesium stearate

Stabilizer: Pentaerythrityl tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] (Chiba Specialty Chemicals, Irganox 1010)

The resin compositions obtained in Examples 6 to 13 and Comparative Examples 6 to 10 were used for evaluation of various properties. The evaluation results are also shown in Tables 3 and 4.

From Tables 1 and 3, in the resin composition (Examples 6 to 13) using the polyester resin (Examples 1 to 5) satisfying the requirements of the present invention, the melting peak temperature of the polyester resin composition by DSC is 280°C. If the above is the case, it can be applied to the reflow soldering process, and if the melting peak temperature exceeds 310℃, the reflow heat resistance temperature is 280℃ or higher, indicating the soldering heat resistance applicable to the gold/tin process soldering process. It has a special effect of excellent adhesion to encapsulant and surface reflectance, which are important characteristics in use, and furthermore, excellent moldability, fluidity, dimensional stability, low water absorption, light resistance, and heat yellowing resistance. On the other hand, from Tables 2 and 4, in the resin composition (Comparative Examples 6 to 9) using the polyester resin (Comparative Examples 1 to 4) which does not satisfy the requirements of the present invention, it was impossible to satisfy all of these characteristics. Although the polyamide resin of Comparative Example 5 has a high melting point, since it has water absorption properties due to the amide structure, the resin composition (Comparative Example 10) using the polyamide resin of Comparative Example 5 does not satisfy the reflow heat resistance temperature of 280°C or higher. Light resistance and heat yellowing resistance were also inferior.

The polyester resin composition of the present invention is not only excellent in heat resistance, moldability, fluidity, and low water absorption, but also has excellent adhesion to the encapsulant in LED applications, and furthermore, a specific polyester resin having excellent light resistance is used. Therefore, it can be suitably used for a reflective plate for surface-mounted LEDs while highly satisfying the required characteristics.

Claims (11)

A dicarboxylic acid component containing 80 mol% or more of at least one selected from the group consisting of 4,4'-biphenyldicarboxylic acid, terephthalic acid and 2,6-naphthalenedicarboxylic acid, and 4,4' -A polyester resin comprising a glycol component containing 15 mol% or more of biphenyldimethanol, wherein glycol components other than 4,4'-biphenyldimethanol are ethylene glycol, 1,4-cyclohexanedimethanol, 1,3 -At least one selected from the group consisting of propanediol, neopentyl glycol, and 1,4-butanediol (however, when ethylene glycol is included in the glycol component, 1 to 5 mol of diethylene glycol relative to the amount of ethylene glycol %), and a polyester resin having a melting point of 280°C or higher. The method of claim 1,
At least one dicarboxylic acid component selected from the group consisting of 4,4'-biphenyldicarboxylic acid, terephthalic acid, and 2,6-naphthalenedicarboxylic acid, and 4,4'-biphenyldimethanol 15 As a polyester resin composed of a glycol component containing at least mol%, even if a glycol component other than 4,4'-biphenyldimethanol contains 1 to 5 mol% of diethylene glycol with respect to the amount of ethylene glycol And a melting point of 280°C or higher. The method of claim 1,
Polyester resin, characterized in that the difference between the melting point (Tm) of the polyester resin and the temperature-fall crystallization temperature (Tc2) is 42°C or less. The method of claim 1,
Polyester resin, characterized in that the acid value of the polyester resin is 1 to 40 eq/t. It contains at least one reinforcing material (C) selected from the group consisting of the polyester resin (A), titanium oxide (B), fibrous reinforcing material and needle-like reinforcing material according to claim 1, and a non-fibrous or non-acicular filler (D), , Titanium oxide (B), reinforcing material (C), and non-fibrous or non-acicular filler (D) per 100 parts by mass of polyester resin (A) are 0.5 to 100 parts by mass, 0 to 100 parts by mass and 0 to 50, respectively A polyester resin composition for use in a reflecting plate for a surface-mounted LED, which is present in a proportion of parts by mass. The method of claim 5,
A polyester resin composition characterized in that the non-fibrous or non-acicular filler (D) is talc, and contains 0.1 to 5 parts by mass of talc based on 100 parts by mass of the polyester resin (A). The method of claim 5,
A polyester resin composition characterized in that the solder reflow heat resistance temperature is 260°C or higher. The method of claim 5,
A polyester resin composition characterized in that the solder reflow heat resistance temperature is 280°C or higher. The method of claim 5,
A polyester resin composition characterized in that the polyester resin composition has a melting peak temperature (Tm) of 280°C or higher, and a difference between a melting peak temperature (Tm) and temperature-fall crystallization temperature (Tc2) of 42°C or less. A reflecting plate for surface-mounted LEDs obtained by molding using the polyester resin composition according to any one of claims 5 to 9. delete