WO2013125454A1 - Polyester resin for surface-mounted led reflective plate - Google Patents

Abstract

The present invention is capable of providing a polyester resin able to be used in a suitable material for a reflective plate for a surface-mounted LED, said resin having excellent heat resistance, excellent moldability during injection molding, excellent low water absorbability and excellent surface reflectivity, and being a polyester resin for a surface-mounted LED reflective plate having: as the constituent components thereof a 4, 4'-biphenyldicarboxylic acid, an acid component comprising other dicarboxylic acids, and a glycol component; a fusion point of at least 280°C; and ideally at least 30 mol% of the total acid component being the 4, 4'-biphenyldicarboxylic acid, and the other dicarboxylic acids being terephthalic acid and/or 2,6-naphthalenedicarboxylic acid.

Description

Polyester resin for surface mount LED reflector

The present invention relates to a polyester resin that can be used as a material suitable for a reflector for a surface-mounted LED having excellent moldability, fluidity, dimensional stability, low water absorption, solder heat resistance, surface reflectance, and the like. Furthermore, this invention relates to the polyester resin which can be used for the material suitable for the reflector for surface mount type LED which is excellent in gold | metal / tin solder heat resistance, light resistance, and low water absorption.

In recent years, LEDs (light-emitting diodes) are used for lighting fixtures, optical elements, mobile phones, backlights for liquid crystal displays, automobile console panels, traffic lights, etc. by utilizing features such as low power consumption, long life, high brightness, and miniaturization. It is applied to display boards. In applications where design and portability are important, surface mounting technology is used to achieve lightness, thinness, and miniaturization.

A surface-mounted LED is generally composed of a light-emitting LED chip, a lead wire, a reflector that also serves as a case, and a sealing resin. In order to join the entire component mounted on an electronic board with lead-free solder In addition, each component must be formed of a material that can withstand the soldering reflow temperature of 260 ° C. The melting point (melting peak temperature) of the material is required to be 280 ° C. or higher. In particular, regarding the reflector, in addition to these heat resistances, surface reflectivity for efficiently extracting light and durability against heat and 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 have been studied. Among them, high refractive fillers such as titanium oxide are dispersed in semi-aromatic polyamides and polyesters. The resin made has a good balance of mass productivity, heat resistance, surface reflectance, etc., and is most commonly used. Recently, with the generalization of LEDs, it is necessary to further improve the workability and reliability of the reflector, and long-term heat-resistant coloring and light resistance are required to be improved.

For example, Patent Documents 1 and 2 have been proposed as polyester resin compositions for LED reflectors.
In Patent Documents 1 and 2, (a) i) terephthalic acid residues 70 to 100 mol%; ii) aromatic dicarboxylic acid residues 0 to 30 mol% having 20 or less carbon atoms; and iii) fats having 16 or less carbon atoms A dicarboxylic acid component comprising from 0 to 10 mol% of an aromatic dicarboxylic acid residue; and (b) i) a 2,2,4,4-tetramethyl-1,3-cyclobutanediol residue from 1 to 99 mol%; and ii) Disclosed is a glycol component containing 1-99 mol% 1,4-cyclohexanedimethanol residues (wherein the total mol% of dicarboxylic acid component is 100 mol% and the total mol% of glycol component is 100 mol%) However, although the mechanical properties tend to be good, there are problems in moldability and light resistance. Further, in Patent Document 3, (A) 100 parts by mass of a polyester resin, (B) 2 to 50 parts by mass of a phosphinate whose anion portion is a calcium salt or aluminum salt of phosphinic acid, and (C) titanium dioxide 0.5 A flame retardant polyester resin composition for a reflector of an illuminating device using a semiconductor light emitting element as a light source, characterized in that it contains 0.01 to 3 parts by mass of (D) a polyolefin resin having a polar group (D). However, there are problems in the heat resistance, heat resistance, and light resistance of gold / tin solder. In Patent Document 4, 100 parts by mass of wholly aromatic thermotropic liquid crystal polyester, 97 to 85% by mass of titanium oxide obtained by a production method including a roasting step, 3 to 15% by mass of aluminum oxide (including hydrate) (Total of 100% by mass of both) comprising 8 to 42 parts by mass of titanium oxide particles surface-treated, 25 to 50 parts by mass of glass fibers, and 0 to 8 parts by mass of other inorganic fillers. Resin composition obtained through a melt-kneading step including a step of supplying at least a part of the glass fiber from a position 30% or more downstream with respect to the total length of the cylinder of the biaxial kneader using a shaft kneader. Although a product is disclosed, there are problems in heat resistance and weather resistance.
Patent Document 5 discloses a dry unsaturated polyester resin composition containing at least an unsaturated polyester resin, a polymerization initiator, an inorganic filler, a white pigment, a release agent, and a reinforcing material, wherein the unsaturated polyester resin is The total amount of the inorganic filler and the white pigment is in the range of 44 to 74% by mass with respect to the total amount of the composition. The proportion of the white pigment in the total amount of the inorganic filler and the white pigment is 30% by mass or more, and the unsaturated polyester resin is mixed with the unsaturated alkyd resin and the crosslinking agent. Although the unsaturated polyester resin composition for LED reflectors characterized by being is disclosed, there exists a problem in a moldability and light resistance. In addition, various polyamides have been used as surface mount LED reflectors, but there are problems with heat-resistant coloring, light resistance, and water absorption.

As described above, conventionally proposed polyesters and polyamides are used while having problems in heat-resistant coloring, light resistance and moldability.

Furthermore, in recent years, it has been actively developed for lighting applications. When considering the development of lighting applications, further cost reduction, higher power, longer life, and long-term reliability are required. Therefore, as a measure for improving the reliability, gold / tin eutectic solder having a low deterioration and a high thermal conductivity is being used instead of the conventional epoxy resin / silver paste for bonding the lead frame and the LED chip. However, since processing of gold / tin eutectic solder requires a temperature of 280 ° C. or higher and lower than 290 ° C., the resin to be used is required to have a melting point of 290 ° C. or higher in order to withstand the process. Further, even when processing gold / tin eutectic solder, the resin is required to have low water absorption in order to prevent blisters from occurring on the surface of the molded product due to moisture in the resin.

As described above, it is preferable that the required melting point of the polyester resin that can be used for the surface mount LED reflector is 280 ° C. or higher, preferably 290 ° C. or higher, and the aromatic ring concentration is high. However, no polyester resin that can be used for a surface mount LED reflector satisfying these requirements has been reported so far.

Special table 2008-544030 gazette Special table 2008-54031 JP 2010-270177 A JP 2008-231368 A Japanese Patent No. 4844699

The present invention was devised in view of the above-mentioned problems of the prior art, and its purpose is moldability during injection molding, fluidity, dimensional stability, low water absorption, solder heat resistance, surface reflectance, An object of the present invention is to provide a polyester resin that can be used as a material suitable for a reflector for a surface-mounted LED having excellent light resistance. Furthermore, an object of the present invention is to provide a high melting point that can be applied to a gold / tin eutectic soldering process and to ensure a long-term reliability, and a low water absorption for reducing swelling of a molded product due to moisture in the soldering process. Another object of the present invention is to provide a polyester resin that can be used as a material suitable for a reflector for a surface mount LED that has achieved light resistance during outdoor use or long-term use.

In order to achieve the above object, the present inventor can advantageously perform injection molding and reflow soldering processes while satisfying the characteristics as an LED reflector, and further, gold / tin eutectic solder heat resistance, low water absorption As a result of intensive studies on the composition of polyester having excellent properties and light resistance, the present invention has been completed.

That is, the present invention has the following configuration.
(1) A polyester resin for a surface-mounted LED reflector, comprising an acid component composed of 4,4′-biphenyldicarboxylic acid and another dicarboxylic acid and a glycol component as constituent components and a melting point of 280 ° C. or higher.
(2) The polyester resin for a surface-mounted LED reflector as described in (1), wherein 30 mol% or more of all acid components constituting the polyester resin is 4,4′-biphenyldicarboxylic acid.
(3) The other dicarboxylic acid constituting the polyester resin is terephthalic acid and / or 2,6-naphthalenedicarboxylic acid. (1) or (2) Polyester resin.
(4) 30 to 90 mol% of the total acid component constituting the polyester resin is 4,4′-biphenyldicarboxylic acid, the other dicarboxylic acid is terephthalic acid and / or 2,6-naphthalenedicarboxylic acid, glycol The component is one or more selected from ethylene glycol, 1,4-cyclohexanedimethanol, 1,3-propanediol, neopentyl glycol, 1,4-butanediol (1) to ( 3) The polyester resin for surface-mounted LED reflectors according to any one of (3), wherein the difference between the melting point (Tm) and the temperature-falling crystallization temperature (Tc2) of the polyester resin is 40 ° C. or less ( 1) A polyester resin for a surface-mounted LED reflector according to any one of (4).
(6) The polyester resin for surface-mounted LED reflectors according to any one of (1) to (5), wherein the acid value of the polyester resin is 1 to 40 eq / t.

The polyester resin of the present invention is excellent in workability such as moldability at the time of injection molding and solder heat resistance in addition to high heat resistance and low water absorption when used in a material used for a reflector for a surface mount LED. Therefore, it is possible to industrially advantageously manufacture a reflector for a surface mount LED that highly satisfies all necessary characteristics.

In addition, since the polyester resin of the present invention has a high melting point and excellent heat resistance, it can be applied to a gold / tin eutectic solder process, and furthermore, since the aromatic ring concentration is high, it has heat resistance, toughness, and weather resistance. It is possible to exhibit characteristics such as excellent properties and excellent adhesion to the sealing material.

The polyester resin of the present invention is intended to be used for a material used for a reflector for a surface mount LED. The surface mount type LED includes a chip LED type using a printed wiring board, a gull wing type using a lead frame, a PLCC type, and the like. The polyester resin of the present invention is formed by injection molding all these reflectors. Can be manufactured.

The polyester resin of the present invention is a polyester resin for a surface-mounted LED reflector having an acid component composed of 4,4′-biphenyldicarboxylic acid and other dicarboxylic acid and a glycol component as constituent components and a melting point of 280 ° C. or higher. .

The polyester resin of the present invention realizes excellent light resistance in addition to high melting point and low water absorption in order to impart high reliability. 4,4′-biphenyldicarboxylic acid and other dicarboxylic acids An acid component and a glycol component consisting of the above are used as constituent components, and the melting point is 280 ° C. or higher. The polyester resin can have a melting point of 280 ° C. or higher by having the following configuration. The melting point of the polyester resin is preferably 290 ° C. or higher, more preferably 300 ° C. or higher, and further preferably 310 ° C. or higher. The upper limit of the melting point of the polyester resin is not particularly set, but is 340 ° C. or lower due to the limitation of the raw material components that can be used.

The polyester resin preferably contains 4,4′-biphenyldicarboxylic acid in an amount of 30 mol% or more, more preferably 4,4′-biphenyldicarboxylic acid in an amount of 50 mol% or more, still more preferably 60 mol% or more. Particularly preferred is 63 mol% or more, and most preferred is 70 mol% or more. If 4,4′-biphenyldicarboxylic acid is less than 30 mol% of the total acid component, moldability, solder heat resistance, and light resistance tend to be lowered. The amount of 4,4′-biphenyldicarboxylic acid is preferably 90 mol% or less of the total acid component. If it exceeds 90 mol%, the melting point of the polyester resin becomes too high, and the setting of the polymerization conditions tends to be difficult.
Other dicarboxylic acids are aromatic dicarboxylic acids such as terephthalic acid, 2,6-naphthalenedicarboxylic acid, isophthalic acid, diphenoxyethane dicarboxylic acid, 4,4′-diphenyl ether dicarboxylic acid, 4,4′-diphenyl ketone dicarboxylic acid, etc. Aliphatic dicarboxylic acids such as acid, adipic acid, sebacic acid, succinic acid, glutaric acid and dimer acid, hexahydroterephthalic acid, hexahydroisophthalic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1 , 4-cyclohexanedicarboxylic acid and the like, and among them, terephthalic acid, 2,6-naphthalenedicarboxylic acid, or a mixture thereof is preferable from the viewpoint of polymerizability, cost, and heat resistance. . Also, polyoxycarboxylic acids such as p-oxybenzoic acid and oxycaproic acid, trimellitic acid, pyromellitic acid, benzophenonetetracarboxylic acid, biphenylsulfonetetracarboxylic acid, biphenyltetracarboxylic acid, and anhydrides thereof You may use together. As the acid component constituting the polyester resin, the total of 4,4′-biphenyldicarboxylic acid and other dicarboxylic acids is preferably 80 mol% or more, more preferably 90 mol% or more, still more preferably 95 mol% or more, 97 mol% or more is particularly preferable, and may be 100 mol%.

Examples of the glycol component of the polyester resin include 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-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-di-n-butyl-1,3-propanediol, 2-ethyl-2-n- Hexyl-1,3-propanediol, 2,2-di-n-hexyl-1,3-propanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, triethylene glycol , Aliphatic glycols such as polyethylene glycol, polytrimethylene glycol, polytetramethylene glycol, polypropylene glycol, hydroquinone, , 4'-dihydroxybisphenol, 1,4-bis (β-hydroxyethoxy) benzene, 1,4-bis (β-hydroxyethoxyphenyl) sulfone, bis (p-hydroxyphenyl) ether, bis (p-hydroxyphenyl) Examples thereof include aromatic glycols such as sulfone, bis (p-hydroxyphenyl) methane, 1,2-bis (p-hydroxyphenyl) ethane, bisphenol A, and alkylene oxide adducts of bisphenol A. Among these, one or two selected from ethylene glycol, 1,4-cyclohexanedimethanol, 1,3-propanediol, neopentyl glycol, and 1,4-butanediol are considered due to heat resistance, polymerizability, molding, cost, and the like. A mixture of species or more is preferred. More preferably, it is at least one selected from ethylene glycol and 1,4-butanediol. In addition, when ethylene glycol is used for the glycol component, diethylene glycol may be produced as a by-product during the production of the polyester resin to become a copolymer component. In this case, diethylene glycol as a by-product is about 1 to 5 mol% with respect to ethylene glycol incorporated in the polyester resin, although it depends on production conditions. Moreover, you may use together polyhydric polyols, such as a trimethylol ethane, a trimethylol propane, glycerol, and a pentaerythritol.
The polyester resin of the present invention is preferably 160 mol% or more, more preferably 180 mol% or more, even more preferably the total of the above-mentioned dicarboxylic acid component and glycol component when the total components are 200 mol%. Is 190 mol% or more and may be 200 mol% (in this case, 100 mol% of dicarboxylic acid component and 100 mol% of glycol component).

When the total amount of ethylene glycol is used as the glycol component of the polyester resin, 4,4′-biphenyldicarboxylic acid is preferably 63 mol% or more, more preferably 70 mol% or more as the acid component. Further, in this case, in order to achieve a more desirable high melting point, it is more preferable that 4,4′-biphenyldicarboxylic acid is 75 mol% or more as an acid component, and 80 mol% or more is particularly preferable.

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

Although it does not specifically limit as a catalyst used when manufacturing a polyester resin, It is preferable that at least 1 type of compound chosen from the compound of Ge, Sb, Ti, Al, Mn, or Mg is used. These compounds are added to the reaction system as powders, aqueous solutions, ethylene glycol solutions, ethylene glycol slurries and the like.

Examples of the Ge compound include amorphous germanium dioxide, crystalline germanium dioxide powder or ethylene glycol slurry, a solution obtained by heating and dissolving crystalline germanium dioxide in water, or a solution obtained by adding ethylene glycol to this and heat treatment. In particular, in order to obtain the polyester used in the present invention, it is preferable to use a solution in which germanium dioxide is dissolved by heating in water, or a solution in which ethylene glycol is added and heated. In addition, compounds such as germanium tetroxide, germanium hydroxide, germanium oxalate, germanium chloride, germanium tetraethoxide, germanium tetra-n-butoxide, and germanium phosphite can also be used. These polycondensation catalysts can be added during the esterification step. When a Ge compound is used, the amount used is preferably 10 to 150 ppm, more preferably 13 to 100 ppm, still more preferably 15 to 70 ppm, most preferably 15 as the residual amount of Ge in the polyester based on the mass of the polyester resin. It is in the range of ˜50 ppm.

Examples of Ti compounds include tetraalkyl titanates such as tetraethyl titanate, tetraisopropyl titanate, tetra-n-propyl titanate, tetra-n-butyl titanate, and partial hydrolysates thereof, titanium acetate, titanyl oxalate, titanyl ammonium oxalate, titanyl oxalate Sodium, titanyl oxalate, titanyl calcium oxalate, titanyl succinate, titanyl succinate, titanium trimellitic acid, titanium sulfate, titanium chloride, titanium halide hydrolyzate, titanium oxalate, titanium fluoride, titanium hexafluoride Potassium acid, ammonium hexafluorotitanate, cobalt hexafluorotitanate, manganese hexafluorotitanate, titanium acetylacetonate, hydroxy polycarboxylic acid or nitrogen-containing polycarboxylic acid Complex compounds comprising titanium and silicon or zirconium, reaction products of titanium alkoxide and phosphorus compound, reaction of titanium alkoxide with aromatic polycarboxylic acid or acid anhydride thereof and specific phosphorus compound Product etc. are mentioned. The Ti compound is added so that the amount of Ti remaining in the produced polymer is preferably in the range of 0.1 to 50 ppm, more preferably 0.5 to 10 ppm with respect to the mass of the polyester resin.

Examples of the Sb compound include antimony trioxide, antimony acetate, antimony tartrate, antimony potassium tartrate, antimony oxychloride, antimony glycolate, antimony pentoxide, and triphenylantimony. The amount of Sb remaining in the produced polymer is preferably 50 to 300 ppm, more preferably 50 to 250 ppm, still more preferably 50 to 200 ppm, and most preferably 50 to 180 ppm, based on the mass of the polyester resin. Add as follows.

Examples of Al compounds include aluminum acetate, basic aluminum acetate, aluminum chloride, aluminum hydroxide, aluminum hydroxide chloride, aluminum carbonate, aluminum phosphate, aluminum phosphonate, and other inorganic acid salts, aluminum n-propoxide, aluminum iso-propoxide Aluminum alkoxides such as aluminum n-butoxide and aluminum t-butoxide, aluminum chelate compounds such as aluminum acetylacetonate, aluminum acetylacetate, aluminum ethylacetoacetate, aluminum ethylacetoacetate diiso-propoxide, trimethylaluminum, triethylaluminum, etc. Organoaluminum compounds and their partial hydrolysates, aluminum oxides Bromide and the like. Of these, aluminum acetate, basic aluminum acetate, aluminum chloride, aluminum hydroxide, aluminum hydroxide chloride and aluminum acetylacetonate are particularly preferred. The Al compound is preferably in the range of 5 to 200 ppm, more preferably 10 to 100 ppm, still more preferably 10 to 50 ppm, and most preferably 12 to 30 ppm, based on the mass of the polyester resin, as the residual amount of Al in the produced polymer. Add as follows.

Further, an alkali metal compound or an alkaline earth metal compound may be used in combination as necessary. The alkali metal or alkaline earth metal is preferably at least one selected from Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, and Ba, and the use of an alkali metal or a compound thereof is preferable. More preferred. When using an alkali metal or a compound thereof, use of Li, Na, K is particularly preferable.

Examples of the alkali metal and alkaline earth metal compounds include saturated aliphatic carboxylates such as formic acid, acetic acid, propionic acid, butyric acid, and succinic acid, and unsaturated aliphatic carboxylates such as acrylic acid and methacrylic acid. , Aromatic carboxylates such as benzoic acid, halogen-containing carboxylates such as trichloroacetic acid, hydroxycarboxylates such as lactic acid, citric acid and salicylic acid, carbonic acid, sulfuric acid, nitric acid, phosphoric acid, phosphonic acid, hydrogen carbonate, phosphorus Inorganic acid salts such as acid hydrogen, hydrogen sulfide, sulfurous acid, thiosulfuric acid, hydrochloric acid, hydrobromic acid, chloric acid and bromic acid, organic sulfonates such as 1-propanesulfonic acid, 1-pentanesulfonic acid and naphthalenesulfonic acid , Organic sulfates such as lauryl sulfate, methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, tert- Alkoxides such as butoxy, chelate compounds and the like acetylacetonate, hydrides, oxides, and hydroxides and the like.

The alkali metal compound or alkaline earth metal compound is added to the reaction system as a powder, an aqueous solution, an ethylene glycol solution, or the like. The alkali metal compound or alkaline earth metal compound is added so that the residual amount of these elements in the produced polymer is preferably in the range of 1 to 50 ppm with respect to the mass of the polyester resin.

Furthermore, the polyester resin according to the present invention is at least one selected from the group consisting of silicon, manganese, iron, cobalt, zinc, gallium, strontium, zirconium, niobium, molybdenum, indium, tin, hafnium, thallium, tungsten. You may contain the metal compound containing these elements. These metal compounds include saturated aliphatic carboxylates such as acetates of these elements, unsaturated aliphatic carboxylates such as acrylates, aromatic carboxylates such as benzoic acid, and halogens such as trichloroacetic acid. Hydroxycarboxylates such as carboxylates and lactates, inorganic acid salts such as carbonates, organic sulfonates such as 1-propanesulfonate, organic sulfates such as lauryl sulfate, oxides, hydroxides, chlorides Products, alkoxides, acetylacetonates, and the like, and are added to the reaction system as powders, aqueous solutions, ethylene glycol solutions, ethylene glycol slurries, and the like. These metal compounds are added so that the residual amount of these metal compound elements per ton of the produced polymer is preferably in the range of 0.05 to 3.0 mol. These metal compounds can be added at any stage of the polyester formation reaction step.

Further, as stabilizers, phosphoric acid, phosphoric acid esters such as polyphosphoric acid and trimethyl phosphate, phosphonic acid compounds, phosphinic acid compounds, phosphine oxide compounds, phosphonous acid compounds, phosphinic acid compounds, phosphine compounds It is preferable to use at least one phosphorus compound selected from the group consisting of: Specific examples include phosphoric acid, phosphoric acid trimethyl ester, phosphoric acid triethyl ester, phosphoric acid tributyl ester, phosphoric acid triphenyl ester, phosphoric acid monomethyl ester, phosphoric acid dimethyl ester, phosphoric acid monobutyl ester, phosphoric acid dibutyl ester, Phosphoric acid, phosphorous acid trimethyl ester, phosphorous acid triethyl ester, phosphorous acid tributyl ester, methylphosphonic acid, methylphosphonic acid dimethyl ester, ethylphosphonic acid dimethyl ester, phenylphosphonic acid dimethylester, phenylphosphonic acid diethylester, phenylphosphonic acid Diphenyl ester and the like. These stabilizers can be added during the esterification reaction step from a slurry preparation tank of terephthalic acid and ethylene glycol. The P compound is preferably in the range of 5 to 100 ppm, more preferably 10 to 90 ppm, still more preferably 10 to 80 ppm, and most preferably 20 to 70 ppm, based on the mass of the polyester resin, as the residual amount of P in the produced polymer. Add as follows.

When an Al compound is used as the polycondensation catalyst, it is preferably used in combination with a phosphorus compound, and is preferably used as a solution or slurry in which an aluminum compound and a phosphorus compound are previously mixed in a solvent. In the case of an Al compound, a more preferable phosphorus compound is at least one selected from the group consisting of phosphonic acid compounds, phosphinic acid compounds, phosphine oxide compounds, phosphonous acid compounds, phosphinic acid compounds, and phosphine compounds. It is a phosphorus compound. By using these phosphorus compounds, an effect of improving the catalytic activity is seen, and an effect of improving physical properties such as thermal stability of the polyester is seen. Among these, use of a phosphonic acid compound is preferable because of its great effect of improving physical properties and improving catalytic activity. Among the above-described phosphorus compounds, the use of a compound having an aromatic ring structure is preferable because the physical property improving effect and the catalytic activity improving effect are great.

Further, the solution, slurry, etc. of the catalyst and stabilizer described above are bubbled with an inert gas having an oxygen concentration of 5 ppm or less, preferably 3 ppm or less, more preferably 2 ppm or less, most preferably 1 ppm or less at the time of preparation or after preparation. Alternatively, it is desirable that the same inert gas be circulated in the gas phase after bubbling with the inert gas in the same manner.

The acid value of the polyester resin of the present invention is preferably 1 to 40 eq / ton. When the acid value exceeds 40 eq / ton, light resistance tends to decrease. On the other hand, when the acid value is less than 1 eq / ton, the polycondensation reactivity tends to decrease and the productivity tends to deteriorate.

The polyester resin of the present invention has a melting point (Tm) in DSC measurement of 280 ° C. or higher, preferably 290 ° C. or higher, more preferably 300 ° C. or higher, particularly preferably 310 ° C. or higher, and most preferably 320 ° C. or higher. . The upper limit of Tm of the polyester resin of the present invention is preferably 340 ° C. or lower for the following reason. When Tm exceeds the above upper limit, the processing temperature required for injection molding the composition using the polyester resin of the present invention becomes extremely high, so that the polyester resin decomposes during processing, and the desired physical properties and appearance are obtained. It may not be possible. On the other hand, when Tm is less than the above lower limit, the crystallization rate is slow, and in some cases, molding may be difficult, and further, solder heat resistance may be reduced. A Tm of 310 ° C. or higher is preferable because it satisfies the reflow solder heat resistance of 280 ° C. and can be applied to a gold / tin eutectic solder process.

Furthermore, the polyester resin of the present invention preferably has a difference between the melting point (Tm) and the cooling crystallization temperature (Tc2) in DSC measurement of 40 ° C. or less, more preferably 35 ° C. or less, and most preferably 30 ° C. or less. is there. The temperature-falling crystallization temperature (Tc2) is a temperature at which crystallization starts when the temperature is lowered from a temperature higher by 10 ° C. or more than the melting point in DSC measurement. The melting point (Tm) and the cooling crystallization temperature (Tc2) are measured by the methods described in the Examples section below. When the difference between the melting point (Tm) and the temperature-falling crystallization temperature (Tc2) is 40 ° C. or less, crystallization easily proceeds and dimensional stability and physical properties can be sufficiently exhibited. On the other hand, when the difference between the melting point (Tm) and the temperature rising crystallization temperature (Tc2) exceeds 40 ° C., the LED reflector is molded in a short cycle of injection molding, so that the crystallization may not proceed sufficiently. Insufficient molding, etc., or crystallization has not been completed sufficiently, causing deformation and crystal shrinkage during heating in the subsequent process, causing problems of peeling from the sealing material and lead frame, resulting in increased reliability Lack.

The intrinsic viscosity (IV) of the polyester resin of the present invention is preferably 0.10 to 0.70 dl / g, more preferably 0.20 to 0.65 dl / g, still more preferably 0.25 to 0.00. 60 dl / g.

The polyester resin of the present invention has an excellent balance of low water absorption and fluidity in addition to a high melting point and moldability, and also has excellent weather resistance. For this reason, the polyester resin composition obtained from such a polyester resin has a high melting point of 280 ° C. or higher in the molding of a reflector for a surface-mounted LED, so that it has heat resistance, crystallinity (moldability), heat yellowing, It is a polyester resin composition suitable for a reflector for a surface-mounted LED having excellent weather resistance and low water absorption.

The polyester resin of the present invention can be produced by a conventionally known production method. A direct esterification method in which an acid component composed of 4,4′-biphenyldicarboxylic acid and another dicarboxylic acid is directly reacted with a glycol component to distill water to esterify, followed by polycondensation under reduced pressure, or 4 It is produced by a transesterification method in which an acid component consisting of dimethyl 4,4'-biphenyldicarboxylate and other dimethyl dicarboxylate and a glycol component are reacted to distill methyl ester by diesterification, followed by polycondensation under reduced pressure. The

By blending the polyester resin of the present invention with titanium oxide, a reinforcing material, a non-fibrous or non-needle filler, and making a polyester resin composition, the material is suitable for a reflector for a surface mount LED. I can do it. When blended, mechanical strength and weather resistance tend to be improved.

Titanium oxide is blended to increase the surface reflectance of the reflector. For example, rutile and anatase titanium dioxide (TiO ₂ ) and titanium monoxide (TiO) produced by the sulfuric acid method or the chlorine method. , Dititanium trioxide (Ti ₂ O ₃ ), and the like, and particularly rutile titanium dioxide (TiO ₂ ) is preferably used. The average particle size of titanium oxide 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 with titanium oxides having different particle sizes. May be used. The titanium oxide component concentration is 90% or more, preferably 95% or more, and more preferably 97% or more. Further, titanium oxide that has been surface-treated with a metal oxide such as silica, alumina, zinc oxide, zirconia, a coupling agent, an organic acid, an organic polyhydric alcohol, or siloxane can be used.

The proportion of titanium oxide is preferably 0.5 to 100 parts by mass, more preferably 10 to 80 parts by mass with respect to 100 parts by mass of the polyester resin. When the ratio of titanium oxide is less than the above lower limit, the surface reflectance is lowered, and when it exceeds the upper limit, molding processability may be lowered, such as a significant decrease in physical properties and fluidity.

The reinforcing material is blended in order to improve the moldability of the polyester resin composition and the strength of the molded product, and at least one selected from a fibrous reinforcing material and a needle-shaped reinforcing material is used. Examples of the fibrous reinforcing material include glass fiber, carbon fiber, boron fiber, ceramic fiber, and metal fiber. Examples of the acicular reinforcing material include potassium titanate whisker, aluminum borate whisker, zinc oxide whisker, and carbonic acid. Calcium whiskers, magnesium sulfate whiskers, wollastonite and the like can be mentioned. As glass fibers, chopped strands or continuous filament fibers having a length of 0.1 mm to 100 mm can be used. As the cross-sectional shape of the glass fiber, a glass fiber having a circular cross section and a non-circular cross section can be used. The diameter of the circular cross-section glass fiber is 20 μm or less, preferably 15 μm or less, more preferably 10 μm or less. Further, a glass fiber having a non-circular cross section is preferred from the viewpoint of physical properties and fluidity. Non-circular cross-section glass fibers include those that are substantially oval, substantially oval, or substantially bowl-shaped in a cross section perpendicular to the length direction of the fiber length, and have a flatness of 1.5 to 8. It is preferable. Here, the flatness is assumed to be a rectangle with the smallest area circumscribing a cross section perpendicular to the longitudinal direction of the glass fiber, the length of the long side of the rectangle is the major axis, and the length of the short side is the minor axis. It is the ratio of major axis / minor axis. The thickness of the glass fiber is not particularly limited, but the minor axis is about 1 to 20 μm and the major axis is about 2 to 100 μm. Further, glass fibers are preferably used in the form of chopped strands which are formed into fiber bundles and cut to a fiber length of about 1 to 20 mm. Furthermore, in order to increase the surface reflectance of the polyester resin composition, it is preferable that the difference in refractive index from the copolyester resin is large, so use a material whose refractive index is increased by changing the glass composition or surface treatment. It is preferable to do.

The proportion of the reinforcing material is preferably 0 to 100 parts by mass, more preferably 5 to 100 parts by mass, and further preferably 10 to 60 parts by mass with respect to 100 parts by mass of the polyester resin. The reinforcing material is not an essential component, but if the proportion is 5 parts by mass or more, the mechanical strength of the molded product is preferably improved. When the ratio of the reinforcing material exceeds the above upper limit, the surface reflectance and the moldability tend to be lowered.

Examples of non-fibrous or non-needle fillers include reinforcing fillers, conductive fillers, magnetic fillers, flame retardant fillers, thermal conductive fillers, thermal yellowing suppression fillers, etc., specifically glass. Beads, glass flakes, 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, lead zirconate titanate, barium titanate, aluminum nitride, boron nitride, zinc borate, barium sulfate, and non-acicular wollastonite, potassium titanate, aluminum borate , Magnesium sulfate, acetate Neshiumu, zinc oxide, calcium carbonate, and the like. These fillers may be used not only alone but also in combination of several kinds. Among these, talc is preferable because Tc1 is lowered and moldability is improved. The addition amount of the filler may be selected as an optimum amount, but it is possible to add a maximum of 50 parts by mass with respect to 100 parts by mass of the polyester resin, but from the viewpoint of the mechanical strength of the resin composition, it is 0. The amount is preferably 1 to 20 parts by mass, more preferably 1 to 10 parts by mass. In order to improve the affinity with the polyester resin, the fibrous reinforcing material and the filler are preferably used after being treated with an organic treatment or a coupling agent, or used in combination with a coupling agent at the time of melt compounding. As the ring agent, any of a silane coupling agent, a titanate coupling agent, and an aluminum coupling agent may be used, and among them, an aminosilane coupling agent and an epoxy silane coupling agent are particularly preferable.

The various additives of the conventional polyester resin composition for LED reflectors can be used for the said polyester resin composition. Additives include stabilizers, impact modifiers, flame retardants, mold release agents, slidability improvers, colorants, fluorescent brighteners, plasticizers, crystal nucleating agents, thermoplastic resins other than polyester, and the like. .

The above-mentioned polyester resin composition can be produced by blending the above-described constituent components by a conventionally known method. Examples include a method in which each component is added during the polycondensation reaction of the polyester resin, a polyester resin and other components are dry blended, or each component is melt-kneaded using a twin screw type extruder. be able to.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. In addition, the measured value described in the Example is measured by the following method.

(1) Intrinsic viscosity of polyester resin (IV)
The viscosity was determined from the solution viscosity at 30 ° C. in a 1,1,2,2-tetrachloroethane / phenol (2: 3 weight ratio) mixed solvent.
(2) Acid value The polyester resin (0.1 g) was dissolved by heating in 10 ml of benzyl alcohol, and then titrated with a 0.1N NaOH methanol / benzyl alcohol (1/9 volume ratio) solution.
(3) Melting point (Tm) and temperature-falling crystallization temperature (Tc2) of the polyester resin
Measured with a differential thermal analyzer (DSC), RDC-220, manufactured by Seiko Electronics Industry Co., Ltd. The temperature was raised at a rate of temperature rise of 20 ° C./minute, held at 330 ° C. for 3 minutes, and then cooled from 330 ° C. to 130 ° C. at a rate of 10 ° C./minute. The peak temperature of the melting peak observed when the temperature was raised was defined as the melting point (Tm), and the peak temperature of the crystallization peak observed when the temperature was decreased was the lowered crystallization temperature (Tc2).

(4) Formability and dimensional stability Using Toshiba Machine's injection molding machine EC-100, the cylinder temperature is set to the melting point of the resin + 20 ° C., the mold temperature is set to 120 ° C., and the film gate is 100 mm long, 100 mm wide, Injection molding was performed using a flat plate forming mold having a thickness of 1 mm. 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. The quality of the moldability was evaluated as follows.
○: A molded product can be obtained without problems.
Δ: Sprue sometimes remains in the mold.
X: The releasability is insufficient, and the molded product sticks to the mold or deforms.
Furthermore, 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 before and after heating was measured, and the amount of dimensional change was determined as follows.
Dimensional change (%) = {Dimension before heating (mm) −Dimension after heating (mm)} / Dimension before heating (mm) × 100
Dimensional stability was evaluated as follows.
○: Dimensional change is less than 0.2% ×: Dimensional change is 0.2% or more

(5) Diffuse reflectance Using Toshiba Machine's injection molding machine EC-100, the cylinder temperature is set to the melting point of the resin + 20 ° C, the mold temperature is set to 140 ° C, and a flat plate 100mm long, 100mm wide and 2mm thick is injection molded. Then, a test piece for evaluation was produced. Using this test piece, an integrating sphere manufactured by Hitachi, Ltd. was installed in a self-recording spectrophotometer “U3500” manufactured by Hitachi, Ltd., and the reflectance at wavelengths from 350 nm to 800 nm was measured. For comparison of reflectance, diffuse reflectance at a wavelength of 460 nm was obtained. Barium sulfate was used as a reference.

(6) Solder heat resistance Using Toshiba Machine's injection molding machine EC-100, the cylinder temperature is set to the melting point of the resin + 20 ° C., the mold temperature is set to 140 ° C., the length is 127 mm, the width is 12.6 mm, and the thickness is 0.8 mm. The test piece for the UL combustion test was injection molded to produce a test piece. The test piece was left in an atmosphere of 85 ° C. and 85% RH (relative humidity) for 72 hours. The specimen was heated in an air reflow furnace (AIS-20-82C manufactured by ATEC) from room temperature to 150 ° C over 60 seconds, preheated, and then heated to 190 ° C at a rate of 0.5 ° C / min. Preheating was performed. Thereafter, the temperature was raised to a predetermined set temperature at a rate of 100 ° C./min, held at the predetermined temperature for 10 seconds, and then cooled. The set temperature was increased from 240 ° C. every 5 ° C., and the highest set temperature at which the surface did not swell or deformed was defined as the reflow heat resistant temperature, which was used as an index of solder heat resistance.
A: Reflow heat resistant temperature is 280 ° C or higher. ○: Reflow heat resistant temperature is 260 ° C or higher and lower than 280 ° C. X: Reflow heat resistant temperature is lower than 260 ° C.

(7) Saturated water absorption Using Toshiba Machine's injection molding machine EC-100, the cylinder temperature is set to the melting point of the resin + 20 ° C, the mold temperature is set to 140 ° C, and a flat plate of 100mm length, 100mm width and 1mm thickness is injection molded. Then, 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 was determined from the following equation from the weight at the time of saturated water absorption and drying.
Saturated water absorption (%) = {(weight at saturated water absorption−weight at drying) / weight at drying} × 100

(8) Fluidity Using Toshiba Machine's injection molding machine IS-100, cylinder temperature is set to 330 ° C, mold temperature is set to 120 ° C, injection pressure set value is 40%, injection speed set value is 40%, weighing is 35mm, Under the conditions of an injection time of 6 seconds and a cooling time of 10 seconds, injection molding was performed with a flow length measuring mold having a width of 1 mm and a thickness of 0.5 mm to prepare an evaluation test piece. As an evaluation of fluidity, the flow length (mm) of this test piece was measured.

(9) Adhesion of silicone Using Toshiba Machine's injection molding machine EC-100, the cylinder temperature is set to the melting point of the resin + 20 ° C, the mold temperature is set to 140 ° C, and a flat plate of 100mm length, 100mm width and 2mm thickness is injection molded. Then, a test piece for evaluation was produced. One side of this test piece was coated with a silicone sealing material (Shin-Etsu Silicone Co., ASP-1110, sealing material hardness D60) to a coating thickness of about 100 μm, and after preheating at 100 ° C. for 1 hour, A curing treatment was performed at 150 ° C. for 4 hours to form a sealing material film on one side of the test piece.
Next, the adhesiveness of the sealing material film on the test piece was evaluated by a cross-cut test based on JIS K5400 (100 mm of 1 mm width crosscut).
○: No more than 10 peeling cells ×: There is peeling when forming the cells before the peeling test

(10) Light resistance Using Toshiba Machine's injection molding machine EC-100, the cylinder temperature is set to the melting point of the resin + 20 ° C, the mold temperature is set to 140 ° C, and a flat plate 100mm long, 100mm wide and 2mm thick is injection molded. A test piece for evaluation was prepared. This test piece was irradiated with UV light at an illuminance of 50 mW / cm ^{2 in} an environment of 63 ° C. and 50% RH using a super accelerated weathering tester “I Super UV Tester SUV-F11”. The light reflectance at a wavelength of 460 nm of the test piece was measured before irradiation and 60 hours after irradiation. The retention rate of the light reflectivity of the post-irradiation test piece relative to the light reflectivity of the pre-irradiation test piece was evaluated according to the following criteria.
○: Retention rate 90% or more △: Retention rate less than 90% to 85% or more ×: Retention rate less than 85%

(11) Heat-resistant yellowing Using Toshiba Machine's injection molding machine EC-100, the cylinder temperature is set to the melting point of the resin + 20 ° C, the mold temperature is set to 140 ° C, and a flat plate of 100mm length, 100mm width and 2mm thickness is injection molded. Then, a test piece for evaluation was produced. Using this test piece, it processed for 2 hours at 150 degreeC with the hot air dryer, and confirmed yellowing visually.
○: No change △: Slightly yellow ×: Yellowish

<Synthesis Example 1>
In a 20-liter stainless steel autoclave with a stirrer, 3542 g of dimethyl 4,4′-biphenyldicarboxylate, 1409 g of high-purity dimethyl terephthalic acid, ethylene glycol in an amount 3 times the acid component, manganese acetate 2 g, and germanium dioxide 0.86 g After the transesterification, while the temperature was raised to 300 ° C. over 60 minutes, the pressure of the reaction system was gradually reduced to 13.3 Pa (0.1 Torr), and a polycondensation reaction was further performed at 310 ° C. and 13.3 Pa. . Subsequent to releasing the pressure, the resin under slight pressure was discharged into water as a strand, cooled, and then cut with a cutter to obtain a cylindrical pellet 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 65 mol% of 4,4′-biphenyldicarboxylic acid, 35 mol% of terephthalic acid, and 98 of ethylene glycol according to ¹ H-NMR measurement. 0.2 mol% and diethylene glycol were 1.8 mol%. The characteristic values of the obtained polyester resin are shown in Table 1.

(Synthesis Examples 2 to 7)
Each polyester resin was obtained in the same manner as in the polymerization of the polyester resin of Synthesis Example 1 except that the amount and type of raw materials used were changed. Table 1 shows the characteristic values of the obtained polyester resins. Diethylene glycol is a by-product of condensation of ethylene glycol.
(Synthesis Example 8)
In a 20 liter stainless steel autoclave with a stirrer, 3542 g of dimethyl 4,4'-biphenyldicarboxylate, 1400 g of high purity dimethyl terephthalic acid, ethylene glycol, manganese acetate 2 g, and 0.86 g of germanium dioxide in an amount three times the acid component. After the transesterification, 8 g of high-purity terephthalic acid was added, and the temperature of the reaction system was gradually decreased to 13.3 Pa (0.1 Torr) while increasing the temperature to 300 ° C. over 60 minutes. The polycondensation reaction was carried out at 13.3 Pa. Subsequent to releasing the pressure, the resin under slight pressure was discharged into water as a strand, cooled, and then cut with a cutter to obtain a cylindrical pellet 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 65 mol% of 4,4′-biphenyldicarboxylic acid, 35 mol% of terephthalic acid, and 98 of ethylene glycol according to ¹ H-NMR measurement. 0.2 mol% and diethylene glycol were 1.8 mol%. The characteristic values of the obtained polyester resin are shown in Table 1.

(Comparative Synthesis Example 1)
A 20-liter stainless steel autoclave with a stirrer is charged with high-purity terephthalic acid and twice its amount of ethylene glycol, and 0.3 mol% of triethylamine is added to the acid component, and water is added at 250 ° C. under a pressure of 0.25 MPa. The esterification reaction was carried out while distilling out of the system to obtain a mixture of bis (2-hydroxyethyl) terephthalate and oligomer (hereinafter referred to as BHET mixture) having an esterification rate of about 95%. To this BHET mixture, germanium dioxide (100 ppm as Ge) was added as a polymerization catalyst, and then stirred at 250 ° C. for 10 minutes under a nitrogen atmosphere at normal pressure. Thereafter, the pressure in the reaction system was gradually decreased to 13.3 Pa (0.1 Torr) while the temperature was raised to 280 ° C. over 60 minutes, and a polycondensation reaction was further performed at 280 ° C. and 13.3 Pa. Subsequent to releasing the pressure, the resin under slight pressure was discharged into water as a strand, cooled, and then cut with a cutter to obtain a cylindrical pellet having a length of about 3 mm and a diameter of about 2 mm. The obtained PET had an IV of 0.61 dl / g, and the resin composition was 100 mol% terephthalic acid, 98.0 mol% ethylene glycol, and 2.0 mol% diethylene glycol, as determined by ¹ H-NMR. It was. The characteristic values of the obtained polyester resin are shown in Table 2.

(Comparative Synthesis Examples 2 to 4)
Each polyester resin was obtained in the same manner as in the polymerization of the polyester resin of Comparative Synthesis Example 1 except that the type of raw material used was changed. Table 2 shows the characteristic values of the obtained polyester resins.

(Comparative Synthesis Example 5: Polyamide resin)
Terephthalic acid 3272.9 g (19.70 mol), 1,9-nonanediamine 2849.2 g (18.0 mol), 2-methyl-1,8-octanediamine 316.58 g (2.0 mol), benzoic acid 73 .27 g (0.60 mol), 6.5 g of sodium hypophosphite monohydrate (0.1% by weight based on the raw material) and 6 liters of distilled water were placed in an autoclave having an internal volume of 20 liters and purged with nitrogen. . The mixture was stirred at 100 ° C. for 30 minutes, and the internal temperature was raised to 210 ° C. over 2 hours. At this time, the autoclave was pressurized to 22 kg / cm ² . The reaction was continued for 1 hour, and then the temperature was raised to 230 ° C., and then the temperature was maintained at 230 ° C. for 2 hours. The reaction was carried out while gradually removing water vapor and maintaining the pressure at 22 kg / cm ² . Next, the pressure was reduced to 10 kg / cm ² over 30 minutes and the reaction was further continued 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. A white polyamide having a melting point of 310 ° C., an intrinsic viscosity [η] of 1.33 dl / g, and a terminal sealing rate of 90% was obtained by solid-phase polymerization at 230 ° C. and 0.1 mmHg for 10 hours. Obtained.

(Examples 1 to 8, Comparative Examples 1 to 5)
Using the polyester resin and polyamide resin obtained in the above synthesis examples and comparative synthesis examples, using the twin-screw extruder STS-35 manufactured by Coperion Co., Ltd. with the components and mass ratios shown in Tables 3 and 4, the melting point of the resin Melting and kneading was performed at + 15 ° C. to obtain a resin composition for evaluation. In Tables 3 and 4, the materials used other than the resin are as follows.
Titanium oxide: manufactured by Ishihara Sangyo Co., Ltd., Taipei CR-60, rutile TiO ₂ , average particle size 0.2 μm
Reinforcing material: Glass fiber (manufactured by Nitto Boseki Co., Ltd., CS-3J-324)
Mold release agent: Magnesium stearate Stabilizer: Pentaerythrityl tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (Irganox 1010, manufactured by Ciba Specialty Chemicals)

The polyester resin compositions and polyamide resin compositions obtained in Examples 1 to 8 and Comparative Examples 1 to 5 were subjected to evaluation of various properties. The results are shown in Tables 3 and 4.

From Tables 1 and 3, if the melting point of the polyester resin by DSC is 280 ° C or higher, it can be applied to the reflow soldering process, and if the melting point exceeds 310 ° C, the reflow heat resistance temperature is 280 ° C or higher. In addition to exhibiting solder heat resistance that can also be applied to gold / tin eutectic soldering processes, it has excellent adhesion with sealing materials, which are important characteristics for LED applications, and surface reflectance. Furthermore, moldability, fluidity, It was confirmed that the dimensional stability, low water absorption, and excellent light resistance were excellent. On the other hand, from Tables 2 and 4, in the comparative example, all of these characteristics could not be satisfied. Although the polyamide resin of Comparative Example 5 has a high melting point, the reflow heat resistant temperature could not satisfy 280 ° C. or higher due to water absorption due to the amide structure.

The polyester resin of the present invention is excellent in workability such as moldability at the time of injection molding and solder heat resistance in addition to high heat resistance and low water absorption when used in a material used for a reflector for a surface mount LED. Therefore, the surface-mounted LED reflector can be industrially advantageously produced while highly satisfying the required characteristics.

Claims (6)

1. A polyester resin for a surface-mounted LED reflector, characterized by comprising an acid component composed of 4,4'-biphenyldicarboxylic acid and other dicarboxylic acid and a glycol component as constituent components and a melting point of 280 ° C or higher.
2. 2. The polyester resin for a surface-mounted LED reflector according to claim 1, wherein 30 mol% or more of the total acid component constituting the polyester resin is 4,4′-biphenyldicarboxylic acid.
3. 3. The polyester resin for a surface-mounting type LED reflector according to claim 1, wherein the other dicarboxylic acid constituting the polyester resin is terephthalic acid and / or 2,6-naphthalenedicarboxylic acid.
4. 30 to 90 mol% of the total acid component constituting the polyester resin is 4,4′-biphenyldicarboxylic acid, the other dicarboxylic acid is terephthalic acid and / or 2,6-naphthalenedicarboxylic acid, and the glycol component is ethylene. 4. One or more kinds selected from glycol, 1,4-cyclohexanedimethanol, 1,3-propanediol, neopentyl glycol, and 1,4-butanediol, The polyester resin for surface mount type LED reflectors described in 1.
5. The polyester resin for a surface-mounted LED reflector according to any one of claims 1 to 4, wherein the difference between the melting point (Tm) of the polyester resin and the temperature-falling crystallization temperature (Tc2) is 40 ° C or less.
6. 6. The polyester resin for a surface-mounted LED reflector according to claim 1, wherein the acid value of the polyester resin is 1 to 40 eq / t.