CN105246941B - Polyester resin and the surface mounting LED reflecting plate polyester and resin composition using polyester resin - Google Patents

Abstract

The invention discloses the polyester resin of a kind of diol component and melting point comprising the dicarboxylic acid component containing 50 moles of more than % of aromatic dicarboxylic acid and containing 15 moles of more than % of 4,4' biphenyl dimethanol more than 280 DEG C.In addition, also disclose a kind of polyester and resin composition, the polyester and resin composition contains the polyester resin (A), titanium oxide (B), the at least one reinforcing material (C) selected from the group being made up of fibrous reinforcements and needle-like reinforcing material, and Non-fibrous or non-needle-like packing material (D), and relative to the mass parts of polyester resin (A) 100, titanium oxide (B), reinforcing material (C), and Non-fibrous or non-needle-like packing material (D) are respectively with 0.5~100 mass parts, 0~100 mass parts, and 0~50 mass parts ratio exist.The polyester and resin composition is suitable for use in surface mounting LED reflecting plate.

Description

Polyester resin and polyester for surface mount LED reflectors using polyester resin resin composition

technical field

The present invention relates to a kind of product which has better formability, fluidity, dimensional stability, low water absorption, solder heat resistance, surface reflectivity, etc., and its gold/tin solder heat resistance, light resistance, low water absorption are also better. The best polyester resin, and a polyester resin composition using the polyester resin that is very suitable for use on a reflector for surface-mounted LEDs.

Background technique

In recent years, LEDs (Light Emitting Diodes) have been applied to lighting fixtures, optical components, mobile phones, backlights for liquid crystal displays, car control panels, signal machines, and display panels by making full use of their characteristics such as low power consumption, long life, high brightness, and miniaturization. Wait. In addition, in applications where designability and portability are important, surface mount technology is used in order to realize thinness, lightness and compactness.

Surface-mounted LEDs are usually composed of light-emitting LED chips, wires, reflectors that double as housings, and sealing resins. However, in order to join all the parts mounted on the electronic substrate by lead-free soldering, each part must Formed in materials resistant to reflow temperatures up to 260°C. The melting point (melting peak temperature) of the material must be above 280°C. In particular, reflectors are required to have high surface reflectance with high light extraction efficiency and durability against heat and ultraviolet rays in addition to these heat resistances. From the above points of view, various heat-resistant plastic materials such as ceramics, semi-aromatic polyamides, liquid crystal polymers, and thermosetting silicones have been investigated. Among them, titanium oxide, etc. are dispersed in semi-aromatic polyamides and polyesters. Resins with high refractive fillers are most commonly used because they have a good balance between mass productivity, heat resistance, and surface reflectance. Recently, along with the generalization of LEDs, it is necessary to further improve the workability and reliability of reflectors, and it is required to improve heat-resistant coloring properties and light resistance over the long term.

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

In Patent Documents 1 and 2, a polyester resin composed of a dicarboxylic acid component (a) and a diol component (b) is disclosed, wherein the dicarboxylic acid component (a) contains: i) 70-100 mole % of phthalic acid residues; ii) 0-30 mole % of aromatic dicarboxylic acid residues with 20 or less carbon atoms; and 0-30 mole % of aliphatic dicarboxylic acid residues with 16 or less carbon atoms 10 mole %; diol component (b) comprises: i) 1～99 mole % of 2,2,4,4-tetramethyl-1,3-cyclobutanediol residue; and ii) 1,4- Cyclohexane dimethanol residue 1～99 mole % (here, the total mole percentage of dicarboxylic acid component is 100 mole %, the total mole percentage of diol component is 100 %), although there are better mechanical properties Trend, but there are problems in formability and light resistance.

In addition, Patent Document 3 discloses a flame-retardant polyester resin composition for a reflection plate of an illumination device using a semiconductor light-emitting element as a light source, which is characterized by mixing The anion part is phosphinate (B) 2-50 parts by mass of calcium salt or aluminum salt of phosphinic acid, 0.5-30 parts by mass of titanium dioxide (C), and 0.01 parts by mass of polyolefin resin (D) having a polar group ~3 parts by mass, however, there are problems in gold/tin solder heat resistance, heat resistance, and light resistance.

In addition, Patent Document 4 discloses a resin composition comprising 100 parts by mass of a wholly aromatic thermotropic liquid crystal polyester, 97 to 85 mass % of titanium oxide obtained by a production method including a firing process, and oxidized 8 to 42 parts by mass of titanium oxide particles surface-treated with 3 to 15% by mass of aluminum (including hydrate) (together 100% by mass), 25 to 50 parts by mass of glass fibers, and other inorganic fillers 0 to 8 parts by mass, and obtained through a melt kneading process comprising a process of using a twin-screw kneader and supplying the above-mentioned At least a portion of glass fibers. However, this resin composition has problems in heat resistance and weather resistance.

In addition, Patent Document 5 discloses an unsaturated polyester resin composition for LED reflectors, which is characterized in that it contains at least an unsaturated polyester resin, a polymerization initiator, an inorganic filler, a white pigment, and a mold release agent. , and a dry unsaturated polyester resin composition for reinforcing materials, the unsaturated polyester resin is in the range of 14 to 40% by mass relative to the overall composition, the inorganic filler and the white The total mixing amount of the pigment is in the range of 44 to 74% by mass relative to the total amount of the composition, and the ratio of the white pigment to the total mixing amount of the inorganic filler and the white pigment is 30%. Mass% or more, the unsaturated polyester resin is a mixture of an unsaturated alkyd resin and a crosslinking agent, but there are problems in moldability and light resistance.

In addition, although various polyamides have been used as reflectors for surface-mounted LEDs, there have been problems in heat-resistant coloring properties, light resistance, and water absorption.

As mentioned above, it is true that conventionally proposed polyesters and polyamides will continue to be used until the problems of heat-resistant coloring properties, light resistance, and moldability are not resolved.

In addition, in recent years, applications to lighting have been actively expanded. In consideration of expansion to lighting applications, further reduction in cost, increase in power, improvement in life, and improvement in long-term reliability are required. Therefore, as a means of improving reliability, instead of using the conventional epoxy resin/silver paste, gold/tin eutectic solder with less deterioration and high thermal conductivity is being used for bonding the lead frame and the LED chip. However, since the processing of gold/tin eutectic solder requires a temperature above 280°C and below 290°C, the melting point of the used resin is required to be above 290°C in order to be able to withstand the process. In addition, when processing gold/tin eutectic solder, the resin is also required to have low water absorption in order to prevent swelling (bubble holes) on the surface of the molded product due to moisture in the resin.

As described above, there has been no report of a polyester resin composition that sufficiently satisfies the characteristics that can be used in reflectors for surface-mounted LEDs.

【Patent Literature】

Patent Document 1: Publication No. 2008-544030 of Japanese Patent Document Special List

Patent Document 2: Publication No. 2008-544031 of Japanese Patent Document Special Table

Patent Document 3: Japanese Patent Document Laid-Open Publication No. 2010-270177

Patent Document 4: Publication of Japanese Patent Application Laid-Open No. 2008-231368

Patent Document 5: Japanese Patent Document Patent Publication No. 4844699

The technical problem to be solved by the invention

The present invention has been made in view of the problems of the prior art described above, and an object of the present invention is to provide a polyester resin and a polyester resin composition for a reflector for surface-mounted LEDs using the polyester resin. Excellent moldability, fluidity, dimensional stability, low water absorption, solder heat resistance, surface reflectivity, and light resistance during injection molding, and gold/tin eutectic solder process is realized to ensure long-term reliability High melting point, low water absorption to reduce swelling of molded products caused by moisture in the welding process, light resistance for outdoor use and long-term use.

Contents of the invention

In order to achieve the above object, the present inventors concentrated on studying not only satisfying the characteristics of a reflector for LED but also being able to carry out injection molding and reflow soldering process conveniently, and its gold/tin eutectic solder has heat resistance, low water absorption and light resistance. The composition of preferred polyester finally completed the present invention.

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

(1) A polyester resin characterized by comprising: a dicarboxylic acid component containing 50 mol% or more of an aromatic dicarboxylic acid and a diol component containing 15 mol% or more of 4,4'-biphenyldimethanol, And the melting point is above 280°C.

(2) The polyester resin described in (1), wherein the aromatic dicarboxylic acid is composed of 4,4'-biphenyldicarboxylic acid, terephthalic acid, and 2,6-naphthalene dicarboxylic acid At least one dicarboxylic acid selected from the group consisting of acids.

(3) The polyester resin described in (1) or (2), characterized in that the diol components other than 4,4'-biphenyldimethanol constituting the polyester resin are composed of ethylene glycol, 1 , at least one diol selected from the group consisting of 4-cyclohexanedimethanol, 1,3-propanediol, neopentyl glycol, and 1,4-butanediol.

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

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

(6) A polyester resin composition used in a reflector for surface-mounted LEDs, wherein the polyester resin composition contains the polyester resin described in any one of (1) to (5) ( A), titanium oxide (B), at least one reinforcing material selected from the group consisting of fibrous reinforcing materials and acicular reinforcing materials (C), and a non-fibrous or non-acicular filler (D), and , with respect to 100 parts by mass of polyester resin (A), titanium oxide (B), reinforcing material (C), and non-fibrous or non-acicular filler (D) are respectively 0.5 to 100 parts by mass, 0 to 100 parts by mass parts, and a ratio of 0 to 50 parts by mass.

(7) The polyester resin composition described in (6), wherein the non-fibrous or non-acicular filler (D) is talcum powder, and with respect to 100 parts by mass of the polyester resin (A), it contains The ratio is 0.1 to 5 parts by mass.

(8) The polyester resin composition described in (6) or (7), wherein the reflow soldering heat resistance temperature is above 260°C

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

(10) The polyester resin composition according to any one of (6) to (9), wherein the melting peak temperature (Tm) of the polyester resin composition is 280° C. or higher, and the melting peak temperature (Tm) The difference from the crystallization temperature (Tc2) when the temperature is lowered is below 42°C.

(11) A reflector for surface-mount LEDs, obtained by molding using the polyester resin composition described in any one of (6) to (10).

Invention effect

The polyester resin of the present invention not only has high heat resistance and low water absorption, but also has excellent processability such as formability during injection molding and solder heat resistance. Therefore, since the polyester resin composition of the present invention uses the polyester resin, it is possible to conveniently and industrially produce a reflector for surface mount type LEDs that highly satisfies all the necessary features.

In addition, the polyester resin composition of the present invention can also be applied to the gold/tin eutectic solder process because the main component polyester resin has a high melting point above 280°C and has good heat resistance, and because the aromatic ring The concentration is high, so it not only has good heat resistance, toughness, and light resistance, but also can show characteristics such as good adhesion with packaging materials.

detailed description

The polyester resin of the present invention has excellent properties as a material used for molded articles such as films, sheets, injection molded articles, and profiled articles, especially as a material used for reflectors for surface-mounted LEDs. Moreover, the polyester resin composition of this invention is used for the reflector plate for surface mount type LEDs. Surface-mounted LEDs include chip LED types using printed wiring boards, gull-wing types using lead frames, and PLCC types, and the polyester resin composition of the present invention can produce all of the reflectors listed above by injection molding. .

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

Polyester resin (A) is formulated to achieve better UV resistance in addition to achieving high melting point and low water absorption in order to impart higher reliability, and is characterized in that it contains: The dicarboxylic acid component containing 50 mol% or more of carboxylic acid and the diol component containing 15 mol% or more of 4,4'-biphenyldimethanol have a melting point of 280°C or higher. The melting point of the polyester resin (A) is preferably 290°C or higher, more preferably 300°C or higher, 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 lower in terms of the raw material components that can be used. Melting point is measured by the method described in the item of Example.

Aromatic dicarboxylic acids used as the dicarboxylic acid component of the polyester resin (A) include 4,4'-biphenyldicarboxylic acid, terephthalic acid, and 2,6-naphthalene dicarboxylic acid , isophthalic acid, diphenoxyethanedicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 4,4'-benzophenone dicarboxylic acid, etc. Among the above-mentioned aromatic dicarboxylic acids, 4,4'-biphenyldicarboxylic acid, terephthalic acid, 2,6-naphthalene dicarboxylic acid, or these are preferable in terms of polymerizability, cost, and heat resistance. mixture. From the standpoint of heat resistance, the aromatic dicarboxylic acid accounts for 50 mol% or more of the dicarboxylic acid component, preferably 60 mol% or more, more preferably 70 mol% or more, still more preferably 80 mol% or more, especially It is preferably 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, dimer acid, hexahydroterephthalic acid, Alicyclic dicarboxylic acids such as hexahydroisophthalic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid, etc. In addition, oxyacids such as p-hydroxybenzoic acid and oxycaproic acid, trimellitic acid, pyromellitic acid, benzophenone tetracarboxylic acid, diphenylsulfone tetracarboxylic acid, and biphenyl tetracarboxylic acid can also be used at the same time. Acid and other polyvalent carboxylic acids and their anhydrates.

In addition, the 4,4'-biphenyldimethanol used as the diol component of the polyester resin (A) needs to contain 15 mol% or more of the total diol components, preferably 4,4'-biphenyldimethanol in 50 mol% or more, more preferably 60 mol% or more, still more preferably 65 mol% or more, most preferably 70 mol% or more. 4,4'-Biphenyldimethanol is added to improve moldability, solder heat resistance, and light resistance. If the ratio is lower than the above values, these properties tend to decrease. Examples of diol components other than 4,4'biphenyldimethanol include ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,2- Butanediol, 1,3-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2-cyclohexanediol, 1,3-cyclohexanediol Hexylene glycol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 1,4-cyclohexanedimethanol Diethanol, 3-methyl-1,5-pentanediol, 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-propanediol, 2,2-bis-n-butyl-1,3-propanediol, 2-ethyl-2-n-hexyl- 1,3-propanediol, 2,2-bis-n-hexyl-1,3-propanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, triethylene Diol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polypropylene glycol and other aliphatic diols, hydroquinone, 4,4'-dihydroxy bisphenol-aldehyde, 1,4-bis(β-hydroxyethoxy base) benzene, 1,4-bis(β-hydroxyethoxyphenyl)sulfone, bis(p-hydroxyphenyl)ether, bis(p-hydroxyphenyl)sulfone, bis(p-hydroxyphenyl) Aromatic diols such as methane, 1,2-bis(p-hydroxyphenyl)ethane, bisphenol A, alkylene oxide adduct of bisphenol A, etc. Among the above diols, ethylene glycol, 1,4-cyclohexanedimethanol, 1,3-propanediol, neopentyl glycol, One or a mixture of two or more selected from 1,4-butanediol. More preferably, it is one or a mixture of two or more selected from ethylene glycol and 1,4-butanediol. In addition, when ethylene glycol is used as the diol component, diethylene glycol may be secondary produced during the production of the polyester resin (A), and may become a copolymerization component. In this case, secondary diethylene glycol depends on production conditions, but is about 1 to 5 mol% relative to ethylene glycol embedded in the polyester resin. In addition, polyols such as trimethylolethane, trimethylolpropane, glycerin, and pentaerythritol can also be used together.

In the polyester resin, when the total components are 200 mol%, the total of the above-mentioned dicarboxylic acid component and diol component is preferably 160 mol% or more, more preferably 180 mol% or more, still more preferably 190 mol% or more , and can also be 200 mol%. However, in either case, the dicarboxylic acid component and the diol component do not exceed 100 mol%.

In addition, in the range of 20 mol% or less of all acid components or all diol components, it is also possible to use 5-sulfoisophthalic acid, 4-sulfonaphthol-2,7-dicarboxylic acid , 5-[4-sulfophenoxy]isophthalic acid and other metal salts, or 2-sulfo-1,4-butanediol, 2,5-dimethyl-3-sulfo-2,5 - A dicarboxylic acid or diol based on a sulfonic acid metal salt such as a metal salt such as hexanediol.

The catalyst used in the production of the polyester resin (A) is not particularly limited, but it is preferable to use at least one compound selected from Ge, Ti, Sb, Al, Mn or Mg compounds. These compounds are added to the reaction system as powders, aqueous solutions, ethylene glycol solutions, ethylene glycol slurries, and the like.

In addition, as a resin stabilizer, it is preferable to use phosphoric acid esters, phosphonic acid compounds, phosphinic acid compounds, phosphine oxide compounds, phosphinic acid compounds, At least one phosphorus compound selected from the group consisting of phosphonic acid compounds and phosphine compounds.

The acid value of the polyester resin (A) is preferably 1 to 40 eq/ton. If the acid value exceeds 40eq/ton, the light fastness tends to decrease. In addition, when the acid value is less than 1 eq/ton, polycondensation reactivity decreases, and productivity tends to decrease.

The polyester resin (A) of the present invention has a melting point (Tm) of 280°C or higher, preferably 290°C or higher, more preferably 300°C or higher, particularly preferably 310°C or higher, most preferably 320°C or higher when measured by DSC. On the other hand, the upper limit of the melting point (Tm) of the polyester resin of the present invention is preferably 340°C or lower. If the melting point (Tm) exceeds 340°C, the processing temperature required for injection molding the composition using the polyester resin (A) of the present invention will become extremely high, so the polyester resin will decompose during processing, Sometimes the desired material and appearance cannot be obtained. Conversely, if the melting point (Tm) is lower than the above-mentioned lower limit, the crystallization rate will be slowed down, molding may become difficult, and solder heat resistance may also be lowered. If the melting point (Tm) is 310°C or higher, it will satisfy the heat resistance of reflow soldering at 280°C, and it can also be applied to the gold/tin eutectic solder process, so it is ideal.

In addition, the polyester resin (A) of the present invention has a difference between the melting point (Tm) when measured by DSC and the crystallization temperature (Tc2) when the temperature is lowered, preferably 42°C or lower, more preferably 40°C or lower, even more preferably 35°C °C or lower, most preferably 30 °C or lower. The crystallization temperature during cooling (Tc2) refers to the temperature at which crystallization starts when the temperature is lowered from a temperature higher than the melting point by 10° C. or higher in DSC measurement. Melting point (Tm) and temperature-falling crystallization temperature (Tc2) were measured by the method described in the item of the Example. When the difference between the melting point (Tm) and the temperature-falling crystallization temperature (Tc2) is below the above temperature, crystallization becomes easy, and dimensional stability, physical properties, etc. can be fully exhibited. On the other hand, if the difference between the melting point (Tm) and the crystallization temperature (Tc2) at the time of cooling exceeds the above-mentioned temperature, the reflector for LEDs will be molded in a short cycle of injection molding, so the crystallization may become insufficient, causing Difficulty in molding such as insufficient mold release, or insufficient crystallization, deformation or crystallization shrinkage occurs during heating in the subsequent process, and problems of peeling from the packaging material or lead frame occur, which lacks 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, still more preferably 0.25 to 0.60 dl/g.

The polyester resin (A) is present in a ratio of preferably 25 to 90% by mass, more preferably 40 to 75% by mass, in the polyester resin composition of the present invention. If the ratio of the polyester resin (A) is lower than the above lower limit, the mechanical strength will decrease, and if it exceeds the above upper limit, the mixing amount of titanium oxide (B) and reinforcing material (C) will be insufficient, and it will be difficult to obtain the desired effect. .

Titanium oxide (B) is mixed in order to increase the surface reflectance of the reflector, for example, rutile type and anatase type titanium dioxide (TiO ₂ ), titanium monoxide ( TiO), titanium trioxide (Ti ₂ O ₃ ), and the like, especially 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 in the range of 0.15 to 0.5 μm, and one kind may be used, or titanium oxides having different particle diameters may be used in combination. The concentration of the titanium oxide component is at least 90% by mass, preferably at least 95% by mass, and more preferably at least 97% by mass. In addition, titanium oxide (B) may be surface-treated with metal oxides such as silica, alumina, zinc oxide, and zirconia, coupling agents, organic acids, organic polyhydric alcohols, and siloxane.

The ratio of titanium oxide (B) is 0.5-100 mass parts with respect to 100 mass parts of polyester resins (A), Preferably it is 10-80 mass parts. If the proportion of titanium oxide (B) is less than the above lower limit, the surface reflectance will decrease, and if it exceeds the above upper limit, the physical properties may be greatly reduced or the flowability may be reduced, which may lower the molding processability.

The reinforcing material (C) is mixed in order to improve the moldability of the polyester resin composition and the strength of the molded product, and at least one selected from fibrous reinforcing materials and needle-shaped reinforcing materials is used. Examples of fibrous reinforcing materials include glass fibers, carbon fibers, boron fibers, ceramic fibers, and metal fibers. Examples of acicular reinforcing materials include potassium titanate whiskers, aluminum borate whiskers, zinc oxide Whiskers, calcium carbonate whiskers, magnesium sulfate whiskers, wollastonite, etc. As the glass fiber, chopped strand or continuous filament fiber having a length of 0.1 mm to 100 mm can be used. 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-sectional glass fiber is preferably 20 μm or less, more preferably 15 μm or less, still more preferably 10 μm or less. In addition, glass fibers with non-circular cross-sections are preferred in terms of physical properties and fluidity. Glass fibers with non-circular cross-sections include generally elliptical, generally oval, and generally cocoon-shaped cross-sections in the cross-section perpendicular to the longitudinal direction of the fiber, and the flatness is preferably 1.5-8. Here, the so-called flatness refers to a rectangle with the smallest area circumscribing a cross-section perpendicular to the longitudinal direction of the glass fiber, when the length of the long side of the rectangle is taken as the long axis and the length of the short side is taken as the short axis. The ratio of major axis/minor axis. The thickness of the glass fiber is not particularly limited, but the short axis is about 1 to 20 μm, and the long axis is about 2 to 100 μm. In addition, the glass fiber is a fiber bundle, and it is preferable to use a fiber bundle cut into a chopped strand shape having a fiber length of about 1 to 20 mm. In addition, in order to increase the surface reflectance of the polyester resin composition, it is preferable to have a large difference in refractive index from the polyester resin, so it is preferable to use a polyester resin whose refractive index is increased by changing the glass composition or surface treatment.

The proportion of the reinforcing material (C) is 0 to 100 parts by mass, preferably 5 to 100 parts by mass, more preferably 10 to 60 parts by mass, based on 100 parts by mass of the polyester resin (A). The reinforcing material (C) is not an essential component, but if the ratio thereof is 5 parts by mass or more, the mechanical strength of the molded article will increase, so it is preferable. When the proportion of the reinforcing material (C) exceeds the above-mentioned upper limit, the surface reflectance and molding processability may be reduced.

As the non-fibrous or non-acicular filler (D), depending on the purpose, reinforcing fillers, conductive fillers, magnetic fillers, flame-retardant fillers, thermally conductive fillers, fillers for thermal yellowing suppression, etc. can be listed. List glass beads, glass flakes, glass beads, silica, talc, kaolin, mica, alumina, aluminum magnesium carbonate, montmorillonite, graphite, carbon nanotubes, fullerenes, indium oxide, tin oxide, Iron oxide, magnesium oxide, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, red phosphorus, calcium carbonate, magnesium acetate, lead zirconate titanate, barium titanate, aluminum nitride, boron nitride, lead borate, barium sulfate , and non-acicular wollastonite, potassium titanate, aluminum borate, magnesium sulfate, zinc oxide, calcium carbonate, etc. These fillers can be used not only individually but in combination of multiple types. Among these, talc powder is preferable because it has an effect of accelerating crystallization and improves moldability. The amount of the filler to be added can be selected in an optimum amount, and a maximum of 50 parts by mass can be added with respect to 100 parts by mass of the polyester resin (A), but from the viewpoint of the mechanical strength of the resin composition, it is preferably 0.1 to 20 parts by mass , More preferably 1 to 10 parts by mass. When using talc powder, it is preferable that it is 0.1-5 mass parts with respect to 100 mass parts of polyester resins (A), and it is more preferable that it is 0.5-3 mass parts. In addition, fibrous reinforcing materials and filling materials can improve the affinity with polyester resins, so it is preferable to use materials treated with organic or coupling agents, or to use them together with coupling agents when melting compounds; as coupling Agents, any of silane coupling agents, titanate coupling agents, and aluminum coupling agents can be used, but among them, aminosilane coupling agents and epoxy silane coupling agents are particularly preferred.

In the polyester resin composition of the present invention, various additives of conventional polyester resin compositions for LED reflectors can be used. Examples of additives include stabilizers, impact modifiers, flame retardants, mold release agents, slippery improving materials, colorants, fluorescent whitening agents, plasticizers, crystal nucleating agents, thermoplastic resins other than polyester, and the like.

Examples of stabilizers for the resin composition include organic antioxidants such as hindered phenol antioxidants, sulfur antioxidants, and phosphorus antioxidants, or heat stabilizers, hindered amines, benzophenones, imidazoles, etc. Such as light stabilizers or ultraviolet absorbers, metal deactivators, copper compounds, etc. As the copper compound, organic compounds such as cuprous chloride, cuprous bromide, cuprous iodide, copper chloride, copper bromide, copper iodide, copper phosphate, copper pyrophosphate, copper sulfide, copper nitrate, copper acetate, etc. can be used. Cuprates of carboxylic acids, etc. In addition, it is preferable to contain an alkali metal halide compound as a component other than the copper compound, and examples of the alkali metal halide compound include lithium chloride, lithium bromide, lithium iodide, sodium fluoride, sodium chloride, sodium bromide, iodine Sodium chloride, potassium fluoride, potassium chloride, potassium bromide, potassium fluoride, etc. These additives may be used alone or in combination. The addition amount of a stabilizer can select an optimal amount, and can add a maximum of 5 mass parts with respect to 100 mass parts of polyester resins (A).

In the polyester resin composition of the present invention, a thermoplastic resin different from the polyester resin (A) may be added. For example: polyamide (PA), polyphenylene sulfide (PPS), liquid crystal polymer (LCP), polytetrafluoroethylene (PTFE), fluorine-containing resin, aramid resin, polyether ether ketone (PEEK), Polyetherketone (PEK), polyetherimide (PEI), thermoplastic polyimide, polyamideimide (PAI), polyetherketoneketone (PEKK), polyphenylene ether (PPE), polyethersulfone ( PES), polysulfone (PSU), polyarylate (PAR), polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate Alcohol ester, polycarbonate (PC), polyoxymethylene (POM), polypropylene (PP), polyethylene (PE), polymethylpentene (TPX), polystyrene (PS), polymethyl Methyl acrylate, acrylonitrile-styrene copolymer (AS), acrylonitrile-butadiene-styrene copolymer (ABS). These thermoplastic resins may be mixed in a molten state by melt-kneading, or the thermoplastic resins may be formed into fibrous or granular forms and dispersed in the polyester resin composition of the present invention. The thermoplastic resin can be added in an optimum amount, but can be added up to 50 parts by mass relative to 100 parts by mass of the polyester resin (A).

Examples of impact modifiers include ethylene-propylene rubber (EPM), ethylene-propylene-diene rubber (EPDM), ethylene-acrylic acid copolymer, ethylene-acrylate copolymer, ethylene-methacrylic acid copolymer, ethylene- Polyolefin resins such as methacrylate copolymer, ethylene vinyl acetate copolymer, styrene-butadiene-styrene block copolymer (SBS), styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-isoprene-styrene block copolymer (SIS), acrylate copolymer and other ethylene polymer resins, polybutylene terephthalate or polybutylene naphthalate Polyester block copolymer with ester as hard segment, polytetramethylene glycol or polycaprolactone or polycarbonate diol as soft segment, nylon elastomer, urethane elastomer, acrylic elastomer, silicone rubber, fluorine Rubber, polymer particles with a core-shell structure composed of two different polymers, etc. The addition amount of the impact modifier can select an optimum amount, and can add up to 30 mass parts with respect to 100 mass parts of polyester resins (A).

For the polyester resin composition of the present invention, when adding a thermoplastic resin other than the polyester resin (A) and an impact modifier, it is preferable to copolymerize a reactive group capable of reacting with the polyester, and the reactive group It is a group capable of reacting with a hydroxyl group and/or a carboxyl group which is a terminal group of a polyester resin. Specifically, an acid anhydride group, an epoxy group, an oxazoline group, an amino group, an isocyanate group, etc. are mentioned, Among these, an epoxy group and an isocyanate group have the best reactivity. In this way, it has also been reported that a thermoplastic resin having a reactive group that reacts with a polyester resin is finely dispersed in polyester, and that the fine dispersion shortens the distance between particles and greatly improves impact resistance.

As a flame retardant, it is preferably a combination of a halogen flame retardant and a flame retardant additive; as a halogen flame retardant, it is preferably brominated polystyrene, brominated polyphenylene ether, brominated bisphenol epoxy polymer brominated styrene maleic anhydride polymer, brominated epoxy resin, brominated phenoxy resin, decabromodiphenyl ether, decabromobiphenyl, brominated polycarbonate, perchlorocyclopentadecane and brominated cross-linked aromatic polymers, etc.; as flame retardant additives, layered silicates such as antimony trioxide, antimony pentoxide, sodium antimonate, zinc stannate, zinc borate, and montmorillonite, Fluoropolymers, silicones, etc. Among them, from the viewpoint of thermal stability, the halogen-based flame retardant is preferably dibromopolystyrene, and the flame retardant aid is preferably combined with any one of antimony trioxide, sodium antimonate, and zinc stannate. In addition, examples of the non-halogen flame retardant include melamine cyanurate, red phosphorus, phosphinic acid metal salts, and nitrogen-containing phosphoric acid compounds. In particular, a combination of a metal salt of phosphinic acid and a nitrogen-containing phosphoric acid compound is preferable, and the nitrogen-containing phosphoric acid compound includes a reaction between melamine, or a condensation product of melamine such as melam, melem, and melon, and polyphosphoric acid. products or their mixtures. As other flame retardants and flame retardant auxiliary agents, when using these flame retardants, it is preferable to add aluminum magnesium carbonate-based compounds or alkali compounds in order to prevent metal corrosion of molds and the like. The flame retardant can be added in an optimum amount, and a maximum of 50 parts by mass can be added with respect to 100 parts by mass of the polyester resin (A).

Examples of the release agent include long-chain fatty acids or their esters and metal salts, amides, polyethylene waxes, silicones, polyethylene oxides, and the like. As the long-chain fatty acid, it is particularly preferable to have a carbon number of 12 or more, for example, stearic acid, 12-hydroxystearic acid, behenic acid, montanic acid, etc., and a part or all of the carboxylic acids can be passed through monoethylene glycol or polyglycol And be esterified, or can also form metal salts. Examples of the amide compound include vinylbisterephthalamide, methylenebisstearamide, and the like. These release agents can be used alone or as a mixture. The addition amount of a mold release agent can select an optimum amount, and can add a maximum of 5 mass parts with respect to 100 mass parts of polyester resins (A).

The polyester resin composition of the present invention contains the above-mentioned polyester resin (A), so the melting peak temperature (Tm) in the DSC measurement is preferably 280° C. or higher, more preferably 290° C. or higher, and still more preferably 300° C. °C or higher, particularly preferably 310 °C or higher, most preferably 320 °C or higher. 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 above-mentioned polyester resin (A), the difference between the peak melting temperature (Tm) and the crystallization temperature (Tc2) when the temperature is lowered in the DSC measurement is preferably 42 °C or lower, more preferably 40 °C or lower, more preferably 35 °C or lower, even more preferably 30 °C or lower.

The polyester resin (A) not only has a high melting point and moldability, but also has a good balance between low water absorption and fluidity, and also has good light resistance. Therefore, the polyester resin composition of the present invention obtained from the polyester resin (A) not only has a high melting point of 280° C. or higher and low water absorption, but also can realize Thin wall and short cycle molding.

The polyester resin composition of the present invention can be produced by mixing the above components by a conventionally known method. For example, during the polycondensation reaction of the polyester resin (A), each component is added, or the polyester resin (A) and other components are dry-blended, or the components are mixed with a twin-screw extruder. method of melt mixing.

Example

Hereinafter, although an Example demonstrates this invention more concretely, this invention is not limited to these Examples. And, the measured values described in the examples are measured by the following methods.

(1) Intrinsic viscosity (IV) of polyester resin

Calculated from the solution viscosity at 30°C in a mixed solvent of 1,1,2,2-tetrachloroethane/phenol (2:3 weight ratio).

(2) acid value

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

(3) The melting point (Tm) of the polyester resin, the melting peak temperature (Tm) of the resin composition, and the crystallization temperature (Tc2) when the temperature is lowered

The measurement was performed using a differential scanning calorimeter (DSC), RDC-220 manufactured by Seiko Instruments Co., Ltd. The temperature was raised at a heating rate of 20°C/minute, and after being held at 330°C for 3 minutes, the temperature was lowered from 330°C to 130°C at a rate of 10°C/minute. In addition, when it does not melt at 330°C, after holding at 340°C for 3 minutes, the temperature is lowered from 340°C to 130°C at a rate of 10°C/min. The peak temperature of the melting peak observed during temperature rise was defined as the melting point (Tm), and the peak temperature of the crystallization peak observed during temperature decrease was defined as the crystallization temperature during temperature decrease (Tc2).

(4) Formability and dimensional stability

Using an injection molding machine EC-100 manufactured by Toshiba Machine, set the cylinder temperature to the melting point of the resin + 20°C, set the mold temperature to 125°C, and use a flat plate with a length of 100 mm, a width of 100 mm, and a thickness of 1 mm with a film gate. Make molds for injection molding. Molding was carried out at an injection speed of 50mm/sec, a holding pressure of 30Mpa, an injection time of 10 seconds, and a cooling time of 10 seconds, and the moldability was evaluated according to the following criteria.

○: A molded product was obtained without any problem.

Δ: Sometimes slag remains in the mold.

×: Mold releasability is insufficient, and the molded product sticks to the mold or deforms.

In addition, in order to evaluate the dimensional stability of the obtained molded product, the molded product was heated at 180° C. for 1 hour. The dimension in the direction perpendicular to the flow direction was measured before and after heating, and the amount of dimensional change was obtained as follows.

Dimensional change (%) = {size before heating (mm) - size after heating (mm)} / size before heating (mm) × 100

Evaluation of dimensional stability was performed according to the following criteria.

○: Dimensional change less than 0.2%

×: Dimensional change is more than 0.2%

(5) Solder heat resistance

Using the injection molding machine EC-100 manufactured by Toshiba Machinery, set the cylinder temperature to the melting point of the resin + 20°C, set the mold temperature to 140°C, and injection-molded a UL combustion test with a length of 127mm, a width of 12.6mm, and a thickness of 0.8mmt Using the test piece, the test piece was made. The test piece was left to stand in an atmosphere of 85° C. and 85% RH (relative temperature) for 72 hours. In a reflow furnace (AIS-20-82C manufactured by Eightech), the test piece was preheated from room temperature to 150°C over 60 seconds, and then preheated up to 190°C at a rate of 0.5°C/min. Then, the temperature was raised to a predetermined set temperature at a rate of 100°C/min, and the temperature was kept at the predetermined temperature for 10 seconds to cool. The set temperature starts at 240°C and increases by 5°C. The highest set temperature at which no surface expansion or deformation occurs is set as the reflow heat resistance temperature, and the solder heat resistance is evaluated using the following criteria.

◎: Reflow heat resistance temperature above 280℃

○: Reflow heat resistance temperature is above 260°C and below 280°C

×: Reflow heat resistance temperature is lower than 260°C

(6) Diffuse reflectivity

Using the injection molding machine EC-100 manufactured by Toshiba Machinery, set the temperature of the cylinder to the melting point of the resin + 20°C, set the temperature of the mold to 140°C, and injection molded a flat plate with a length of 100 mm, a width of 100 mm, and a thickness of 2 mm. Test pieces for evaluation. Using this test piece, an integrating sphere manufactured by Hitachi, Ltd. was installed on an automatic recording spectrophotometer "U3500" manufactured by Hitachi, Ltd., and the reflectance at a wavelength of 350 nm to 800 nm was measured. As a comparison of the reflectance, the diffuse reflectance at a wavelength of 460 nm was obtained. The reference used barium sulfate.

(7) Saturated water absorption

Using the injection molding machine EC-100 manufactured by Toshiba Machinery, set the temperature of the cylinder to the melting point of the resin + 20°C, set the temperature of the mold to 140°C, and injection molded a flat plate with a length of 100mm, a width of 100mm, and a thickness of 1mm, and produced Test pieces for evaluation. The test piece was immersed in hot water at 80° C. for 50 hours, and the saturated water absorption rate was obtained from the weight at the time of saturated water absorption and the time of drying, and the following formula.

Saturated water absorption (%)={(weight at saturated water absorption-weight at dry time)/weight at dry time}×100

(8) Liquidity

Using the injection molding machine IS-100 manufactured by Toshiba Machinery, set the cylinder temperature to 330°C, set the mold temperature to 120°C, and set the injection pressure at 40%, the injection speed at 40%, Under the conditions of a gauge of 35 mm, an injection time of 6 seconds, and a cooling time of 10 seconds, injection molding was performed in a flow length measurement mold having a width of 1 mm and a thickness of 0.5 mm, and a test piece for evaluation was prepared. The flow length (mm) of this test piece was measured as the evaluation of fluidity.

(9) Silicone adhesion

Using the injection molding machine EC-100 manufactured by Toshiba Machinery, set the temperature of the cylinder to the melting point of the resin + 20°C, set the temperature of the mold to 140°C, and injection molded a flat plate with a length of 100 mm, a width of 100 mm, and a thickness of 2 mm. Test pieces for evaluation. On one side of this test piece, a silicone sealing material (manufactured by Shin-Etsu Silicone Co., Ltd., ASP-1110, sealing material hardness D60) was coated to a thickness of about 100 μm, and after preheating at 100° C. for 1 hour, Hardening treatment was performed at 150° C. for 4 hours, so that a thin film of the encapsulating material was formed on one side of the test piece.

Next, the sealing material film on the test piece was subjected to a cross-hatch test (100 grids of 1 mm width) according to JIS K5400, and the adhesion was evaluated according to the following criteria.

○: The number of stripped grid holes is less than 10

×: Peeling occurred when the number of grid holes before the peeling test was formed

(10) Lightfastness

Using the injection molding machine EC-100 manufactured by Toshiba Machinery, set the temperature of the cylinder to the melting point of the resin + 20°C, set the temperature of the mold to 140°C, and injection molded a flat plate with a length of 100 mm, a width of 100 mm, and a thickness of 2 mm. Test pieces for evaluation. This test piece was irradiated with UV at an illuminance of 50 mW/cm ² in an environment of 63° C. and 50% RH using a super-accelerated weather resistance tester “Eye super UV tester-SUV-F11”. Before irradiation and after irradiation for 60 hours, the light reflectance of the test piece at a wavelength of 460 nm was measured. The light resistance was evaluated according to the following criteria based on 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.

◎: The maintenance rate is above 95%

○: The retention rate is less than 95% and more than 90%

Δ: The retention rate is below 90% and above 85%

×: The retention rate is less than 85%

(11) heat resistance yellowing

Using the injection molding machine EC-100 manufactured by Toshiba Machinery, set the temperature of the cylinder to the melting point of the resin + 20°C, set the temperature of the mold to 140°C, and injection molded a flat plate with a length of 100 mm, a width of 100 mm, and a thickness of 2 mm. Test pieces for evaluation. Using this test piece, it processed using the hot-air dryer at 150 degreeC for 2 hours, the yellowing property was confirmed visually, and it evaluated according to the following criteria.

○: no change

Δ: slightly yellowed

×: yellowing

(Example 1)

In a 20-liter stainless steel autoclave equipped with a stirrer, put 3880g of high-purity dimethyl terephthalic acid, 2782g of 4,4'-biphenyldimethanol, 1922g of ethylene glycol, 2g of manganese acetate, and 0.86g of germanium dioxide , after the transesterification, the temperature was raised to 300° C. in 60 minutes, and the pressure of the reaction system was slowly lowered to 13.3 Pa (0.1 Torr), and then the polycondensation reaction was carried out at 310° C. and 13.3 Pa. After the pressure was released, the slightly pressurized resin was discharged in water into a thread shape, and after cooling, it was cut with a cutter to obtain cylindrical pellets with a length of about 3 mm and a diameter of about 2 mm. The intrinsic viscosity of the obtained polyester resin is 0.60dl/g, measured according to ¹ H-NMR, in the resin composition, terephthalic acid is 100 mole%, 4,4'-biphenyl dimethanol is 65 mole%, ethylene glycol is 34.5 mol%, and diethylene glycol is 0.5 mol%. The composition and characteristic values of the obtained polyester resin are shown in Table 1.

(Embodiments 2-4)

Each polyester resin was obtained in the same manner as the polymerization of the polyester resin in Example 1, except that the amount and type of raw materials used were changed. Table 1 shows the compositions and characteristic values of the obtained polyester resins. In addition, diethylene glycol is secondary to the condensation of ethylene glycol.

(Example 5)

In a 20-liter stainless steel autoclave equipped with a stirrer, put 3880g of high-purity dimethyl terephthalic acid, 2782g of 4,4'-biphenyldimethanol, 1922g of ethylene glycol, 2g of manganese acetate, and 0.86g of germanium dioxide After transesterification, add 8g of high-purity terephthalic acid, raise the temperature to 300°C in 60 minutes, slowly lower the pressure of the reaction system to 13.3Pa (0.1Torr), and carry out polycondensation reaction at 310°C and 13.3Pa . After the pressure was released, the slightly pressurized resin was discharged into a thread shape in water, and after cooling, it was cut with a cutter to obtain cylindrical pellets with a length of about 3 mm and a diameter of about 2 mm. The intrinsic viscosity of the obtained polyester resin is 0.60dl/g. According to ¹ H-NMR measurement, in the resin composition, terephthalic acid is 100 mol%, 4,4'-biphenyl dimethanol is 65 mol%, ethylene dimethanol is Alcohol is 34.5 mol%, and diethylene glycol is 0.5 mol%. The composition and characteristic values of the obtained polyester resin are shown in Table 1.

(comparative example 1)

Into a 20-liter stainless steel autoclave equipped with a stirrer, put high-purity terephthalic acid and ethylene glycol in an amount twice the mole, add 0.3 mol% of triethylamine relative to the acid component, and pressurize at 0.25MPa, Carry out esterification while water is distilled out from the system at 250° C. to obtain a mixture of bis(2-hydroxyethyl) terephthalate and oligomers (hereinafter referred to as the esterification rate) of about 95%. for the BHET mixture). Germanium dioxide (Ge: 100 ppm) was added as a polymerization catalyst to this BHET mixture, followed by stirring at 250° C. for 10 minutes under a nitrogen atmosphere and normal pressure. Then, the temperature was raised to 280° C. over 60 minutes, and the pressure of the reaction system was slowly lowered to 13.3 Pa (0.1 Torr), and the polycondensation reaction was carried out at 280° C. and 13.3 Pa. After the pressure was released, the slightly pressurized resin was discharged in water into a thread shape, and after cooling, it was cut with a cutter to obtain cylindrical pellets with 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, measured by ¹ H-NMR, and in the resin composition, terephthalic acid was 100 mol%, ethylene glycol was 98.0 mol%, and diethylene glycol was 2.0 mol%. The composition and characteristic values of the obtained polyester resin are shown in Table 2.

(Comparative examples 2 to 4)

Each polyester resin was obtained in the same manner as the polymerization of the polyester resin in Comparative Example 1 except that the type of raw material used was changed. Table 2 shows the compositions and characteristic values of the obtained polyester resins.

(Comparative example 5: polyamide resin)

3272.9 g (19.70 moles) of terephthalic acid, 2849.2 g (18.0 moles) of 1,9-diaminononane, 316.58 g (2.0 moles) of 2-methyl-1,8-octanediamine, and 73.27 g of benzoic acid (0.60 mol), sodium hypophosphite monohydrate 6.5g (0.1% by weight relative to the raw material) and 6 liters of distilled water were put into an autoclave with an inner volume of 20 liters, and nitrogen replacement was performed. It stirred at 100 degreeC for 30 minutes, and heated up internal temperature to 210 degreeC over 2 hours. At this time, the pressure of the reactor was increased to 22kg/cm ² . After continuing the reaction for 1 hour, the temperature was raised to 230° C., and then kept at 230° C. for 2 hours, water vapor was slowly removed, and the reaction was carried out while maintaining the pressure at 22 kg/cm ² . Next, the pressure was lowered to 10 kg/cm ² over 30 minutes, and further reacted for 1 hour to obtain a prepolymer having an intrinsic viscosity [η] of 0.25 dl/g. This was dried at 100° C. under reduced pressure for 12 hours, and pulverized to a size of 2 mm or less. This was solid-phase polymerized 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 an end sealing rate of 90%. Table 2 shows the composition and characteristic values of the obtained polyamide resin.

Table 1

Table 2

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

With the components and mass ratios described in Tables 3 and 4, by using a twin-screw extruder STS-35 manufactured by Coperion Co., Ltd., melt mixing was carried out at the melting point of polyester resin (A) or polyamide resin at +15°C. refining to obtain the resin compositions of Examples 6-13 and Comparative Examples 6-10. In Tables 3 and 4, details of materials used other than the polyester resin (A) are as follows.

Titanium oxide (B): Tipaque CR-60 manufactured by Ishihara Sangyo Co., Ltd., rutile type TiO ₂ , average particle diameter 0.2 μ

Reinforcing material (C): glass fiber (manufactured by Nitto Bosho Co., Ltd., CS-3J-324), acicular wollastonite (manufactured by NYCO Co., Ltd., NYGLOS8)

Filler (D): Talc powder (micro wollastonite 5000A manufactured by Hayashi Kasei Co., Ltd.)

Release agent: magnesium stearate

Stabilizer: tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester, (Antioxidant 1010 manufactured by Ciba Specialty Chemicals Inc.)

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

table 3

Table 4

It can be seen from Table 1 and Table 3 that in the resin compositions (Examples 6-13) using the polyester resins (Examples 1-5) that meet the requirements of the present invention, the polyester resin composition is based on the melting of DSC. When the peak temperature is above 280°C, it can be applied to the reflow soldering process, and when the melting peak temperature exceeds 310°C, since the reflow heat resistance temperature is above 280°C, it shows the solder that can also be applied to the gold/tin eutectic solder process Heat resistance, at the same time, among the important characteristics of LED applications, it can be confirmed that the adhesion with the packaging material and the surface reflectance are good, and the moldability, fluidity, dimensional stability, low water absorption, light resistance, heat resistance and flooding Also good noticeable effect on yellowness. On the other hand, as can be seen from Table 2 and Table 4, in the resin compositions (Comparative Examples 6-9) using polyester resins (Comparative Examples 1-4) that do not satisfy the requirements of the present invention, the requirements cannot be satisfied. All these properties. Although the polyamide resin in Comparative Example 5 has a high melting point, due to the water absorption due to the amide structure, the resin composition using the polyamide resin in Comparative Example 5 (Comparative Example 10) did not meet the reflow heat resistance temperature of 280°C. Above, and light resistance, heat yellowing resistance is also poor.

Industrial availability

The polyester resin composition of the present invention uses a specific polymer that not only has better heat resistance, moldability, fluidity, and low water absorption, but also has better adhesion to packaging materials in LED applications, and has better light resistance. Since the ester resin satisfies the required characteristics to a high degree, it can be preferably used for a reflector for surface mount type LEDs.

Claims (11)

1. A polyester resin characterized by comprising: a dicarboxylic acid component containing 50 mol% or more of an aromatic dicarboxylic acid; and a diol group containing 15 mol% or more of 4,4'-biphenyldimethanol points, and the melting point is above 280°C. 2. The polyester resin according to claim 1, wherein the aromatic dicarboxylic acid comprises 4,4'-biphenyl dicarboxylic acid, terephthalic acid, and 2,6-naphthalene dicarboxylic acid At least one dicarboxylic acid selected from the group consisting of acids. 3. The polyester resin according to claim 2, wherein the diol components other than 4,4'-biphenyl dimethanol constituting the polyester resin include ethylene glycol, 1,4-cyclo At least one diol selected from the group consisting of hexanedimethanol, 1,3-propanediol, neopentyl glycol, and 1,4-butanediol. 4. The polyester resin according to any one of claims 1 to 3, wherein the difference between the melting point Tm of the polyester resin and the crystallization temperature Tc2 during cooling is 42°C or less. 5. The polyester resin according to any one of claims 1 to 3, characterized in that the acid value of the polyester resin is 1 to 40 eq/t. 6. A polyester resin composition used in a reflector for surface-mounted LEDs, characterized in that the polyester resin composition contains: the polyester resin (A) described in any one of claims 1 to 5 ), titanium oxide (B), at least one reinforcement material (C) selected from the group consisting of fibrous reinforcement materials and acicular reinforcement materials (C), and non-fibrous or non-acicular filler materials (D), and relatively In 100 parts by mass of polyester resin (A), titanium oxide (B), reinforcing material (C), and non-fibrous or non-needle filler (D) are used in 0.5-100 parts by mass, 0-100 parts by mass, And it exists in the ratio of 0-50 mass parts. 7. The polyester resin composition as claimed in claim 6, wherein the non-fibrous or non-acicular filler (D) is talcum powder, and with respect to 100 parts by mass of the polyester resin (A), the content ratio It is 0.1-5 mass parts. 8. The polyester resin composition according to claim 6 or 7, characterized in that the reflow soldering heat resistance temperature is above 260°C. 9. The polyester resin composition according to claim 6 or 7, characterized in that the reflow soldering heat resistance temperature is above 280°C. 10. polyester resin composition as claimed in claim 6 or 7 is characterized in that, the melting peak temperature Tm of polyester resin composition is more than 280 ℃, and the difference of crystallization temperature Tc during melting peak temperature Tm and cooling is in Below 42°C. 11 . A reflector for surface-mounted LEDs, which is molded using the polyester resin composition according to claim 6 .