TW201343711A - 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 DEG 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 type LED reflector

The present invention relates to a polyester resin which is suitable for use as a material for a surface mount LED reflector which is excellent in moldability, fluidity, dimensional stability, low water absorbability, solder heat resistance, surface reflectance and the like. Further, the present invention relates to a polyester resin which is suitable for use as a material for a surface-mounted LED reflector which is excellent in heat resistance, light resistance and low water absorption of gold/tin solder.

In recent years, LEDs (light-emitting diodes) have been widely used in lighting fixtures, optical components, mobile phones, backlights for liquid crystal displays, and automotive control panels by utilizing features such as low power consumption, long life, high brightness, and miniaturization. , traffic signs, display boards, etc. In addition, in the use of design and portability, surface mounting technology is used to reduce the thickness and thickness.

The surface mount type LED is generally composed of a light-emitting LED chip, a lead wire, a reflector which also serves as a case, and a sealing resin. In order to bond the entire component mounted on the electronic substrate in a lead-free soldering manner, each component must be capable of withstanding It is formed by welding a material having a reflow temperature of 260 °C. The melting point (melting peak temperature) of the material must be 280 ° C or higher. In particular, in addition to such heat resistance, the reflecting plate is required to have a surface reflectance for efficiently extracting light and durability against heat and ultraviolet rays. From this point of view, various types of heat-resistant plastic materials such as ceramics, semi-aromatic polyamides, liquid crystal polymers, and thermosetting polyfluorenes have been studied. Among them, high-refractive fillers such as titanium oxide are dispersed in half. A resin composed of an aromatic polyamide and a polyester has a good balance between mass productivity, heat resistance, surface reflectance, and the like, and is most widely used. Recently, with the ubiquity of LEDs, it is necessary to further improve the processability and reliability of the reflector, and it is required to improve long-term heat resistance and light resistance.

As a polyester resin composition for an LED reflector, for example, Patent Documents 1 to 2 are proposed.

Patent Documents 1 and 2 propose (a) containing i) a citric acid residue of 70 to 100 mol%; ii) an aromatic dicarboxylic acid residue having a carbon number of 20 or less; 0 to 30 mol%; and iii) a dicarboxylic acid component having 0 to 10 mol% of an aliphatic dicarboxylic acid residue having a carbon number of 16 or less; and (b) i) 2,2,4,4-tetramethyl-1,3-cyclobutane Alcohol residue 1 to 99 mol %; and ii) 1,4-cyclohexane dimethanol residue 1 to 99 mol% of the diol component (here, the total molar % of the dicarboxylic acid component is 100 mol) The ear %, the total molar % of the diol component is 100 mol%), and the mechanical properties tend to be good, but there are still problems of formability and light resistance. Further, Patent Document 3 proposes a flame-retardant polyester resin composition for a reflector for an illumination device using a semiconductor light-emitting element as a light source, characterized in that (B) anion is blended with respect to 100 parts by mass of the (A) polyester resin. a part of the phosphinate salt of the phosphinic acid or the aluminum salt of 2 to 50 parts by mass, (C) 0.5 to 30 parts by mass of the titanium oxide, and (D) the polyolefin resin having a polar group of 0.01 to 3 parts by mass, but There is still the problem of heat resistance, heat resistance and light resistance of gold/tin solder. Further, Patent Document 4 proposes a resin composition obtained by a melt kneading step comprising the following steps: 100 parts by mass of a wholly aromatic thermal liquid crystal polyester, and alumina (including a hydrate) 3~ 15% by mass (total of 100% by mass), 8 to 42 parts by mass of titanium oxide particles, which are surface-treated with 97 to 85% by mass of titanium oxide obtained by the method for calcination, and glass fibers 25 to 50 The mass portion and the other inorganic fillers are composed of 0 to 8 parts by mass, and at least a part of the glass is supplied from the lower side of the cylinder of the biaxial kneading machine from the lower side of the cylinder of 30% or more using the biaxial kneading machine. The step of fiber, but there are still problems of heat resistance and weather resistance.

Further, Patent Document 5 proposes an unsaturated polyester resin composition for an LED mirror, which is characterized in that it contains at least an unsaturated polyester resin, a polymerization initiator, an inorganic filler, a white pigment, a release agent, And a dry unsaturated polyester resin composition of the reinforcing material, wherein the unsaturated polyester resin is in a range of 14 to 40% by mass based on the total amount of the composition, and the amount of the inorganic filler blended with the white pigment In the range of 44 to 74% by mass based on the total amount of the composition, the ratio of the white pigment to the total amount of the inorganic filler and the white pigment blended is 30% by mass or more, and the unsaturated polyester resin is mixed. There are unsaturated alkyd resins and cross-linking agents, but there are still problems of formability and light resistance. Further, the surface-mounted LED reflectors of the prior art have various problems of heat-resistant coloring property, light resistance, and water absorption, although various polyimides are used.

As described above, the polyester and polyamine which have been proposed in the past have heat-resistant coloring properties. It is used for the problem of light resistance and formability.

Furthermore, in recent years, development of lighting applications has also been actively carried out. Considering the development of lighting applications, it is further required to reduce costs and power, improve life and improve long-term reliability. Therefore, as a strategy for improving reliability, gold/tin eutectic soldering with less deterioration and high thermal conductivity is used instead of the conventional epoxy resin/silver paste for bonding the lead frame and the LED wafer. However, since the processing of the gold/tin eutectic soldering is performed at a temperature of 280 ° C or higher and lower than 290 ° C, the melting point of the resin to be used is required to be 290 ° C or higher in order to withstand the process. Further, in the processing of gold/tin eutectic soldering, in order to prevent swelling (foaming) of the surface of the molded article due to moisture in the resin, the resin is required to have low water absorption.

As described above, the polyester resin which can be used for the surface-mounted reflective sheet for LEDs preferably has a melting point of 280 ° C or higher, preferably 290 ° C or higher, and a high aromatic ring concentration. However, a polyester resin which can be used for a surface-mounted reflective sheet for LEDs which satisfies these characteristics has not been reported so far.

[Previous Technical Literature] [Patent Literature]

Patent Document 1: Special Table 2008-544030

Patent Document 2: Japanese Patent Publication No. 2008-544031

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

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

Patent Document 5: Japanese Patent No. 4844699

The present invention has been made in view of the above-described problems of the prior art, and an object thereof is to provide moldability, fluidity, dimensional stability, low water absorption, weld heat resistance, surface reflectance, and light resistance which are suitable for injection molding. Polyester tree used for the material of the surface mount type LED reflector fat. Further, an object of the present invention is to provide a polyester resin suitable for use as a material for a surface-mounted LED reflector, which can achieve long-term reliability and can be adapted to gold/tin eutectic soldering. The high melting point of the step, the low water absorption for reducing the expansion of the molded article due to the moisture in the welding step, the outdoor use and the light resistance at the time of long-term use.

In order to achieve the above object, the inventors of the present invention have intensively studied to satisfy the characteristics as an LED reflector and to facilitate the injection molding and reflow steps, and also excellent in heat resistance, low water absorption, and light resistance of gold/tin eutectic soldering. The composition of the ester, as a result, completed the present invention.

That is, the present invention has the following constitution.

(1) A polyester resin for a surface mount type LED reflector, characterized in that it is an acid component composed of 4,4'-biphenyldicarboxylic acid and another dicarboxylic acid, and a diol component. The constituent component has a melting point of 280 ° C or higher.

(2) The polyester resin for a surface mount type LED reflector according to (1), wherein 30 mol% or more of all the acid components constituting the polyester resin is 4,4'-biphenyldicarboxylic acid.

(3) The polyester resin for a surface mount type LED reflector according to (1) or (2), wherein the other dicarboxylic acid constituting the polyester resin is p-citric acid and/or 2,6-naphthalene dicarboxylate. acid.

(4) The polyester resin for a surface mount type LED reflector according to any one of (1) to (3), wherein 30 to 90 mol% of all the acid components constituting the polyester resin is 4, 4' -biphenyldicarboxylic acid, the other dicarboxylic acid is p-citric acid and / or 2,6-naphthalenedicarboxylic acid, the diol component is selected from ethylene glycol, 1,4-cyclohexane dimethanol, 1 One or more of 3-propanediol, neopentyl glycol, and 1,4-butanediol.

(5) The polyester resin for a surface mount type LED reflector according to any one of (1) to (4) wherein a difference between a melting point (Tm) of the polyester resin and a temperature-lowering crystallization temperature (Tc2) is 40. Below °C.

(6) The polyester resin for a surface mount type LED reflector according to any one of (1) to (5), wherein the polyester resin has an acid value of 1 to 40 eq/t.

In the case where the polyester resin of the present invention is used as a material for a surface-mounted reflective sheet for LED, moldability and weld resistance at the time of injection molding are in addition to high heat resistance and low water absorption. Since the heat resistance and the like are also excellent in the workability, it is industrially advantageous to manufacture a reflector for a surface mount type LED which satisfies all necessary characteristics.

Moreover, since the polyester resin of the present invention has high melting point and excellent heat resistance, it can also be adapted to the gold/tin eutectic soldering step, and further, it exhibits excellent heat resistance and toughness due to a high aromatic ring concentration. It is also characterized by weather resistance and adhesion to the sealing material.

[Formation of the Invention]

The polyester resin of the present invention is intended to be used as a material for a surface-mounted reflector for LEDs. The surface mount type LED includes a wafer LED type using a printed wiring board, a gull wing type using a lead frame, a PLCC type, and the like, and the polyester resin of the present invention can be manufactured by an injection molding method. Reflective plate.

The polyester resin of the present invention is a surface-mounted polyester resin for a LED reflector, which is obtained by using an acid component composed of 4,4'-biphenyldicarboxylic acid and another dicarboxylic acid, and a diol component. The constituent component has a melting point of 280 ° C or higher.

The polyester resin of the present invention is characterized in that, in addition to high melting point and low water absorption, excellent light resistance can be achieved due to high reliability, and 4,4'-biphenyldicarboxylic acid and An acid component composed of another dicarboxylic acid and a diol component are constituent components, and the melting point is 280 ° C or higher. Since the polyester resin has the following constitution, the melting point can be 280 ° C or higher. The melting point of the polyester resin is preferably 290 ° C or higher, more preferably 300 ° C or higher, and still more preferably 310 ° C or higher. The upper limit of the melting point of the polyester resin is not particularly limited, and is limited to 340 ° C or less by the raw material component which can be used.

The polyester resin preferably has a content of 4,4'-biphenyldicarboxylic acid of 30 mol% or more of all the acid components, more preferably 50 mol% or more of 4,4'-biphenyldicarboxylic acid, or more. Preferably, it is 60 mol% or more, particularly preferably 63 mol% or more, and most preferably 70 mol% or more. When the 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 4,4'-biphenyldicarboxylic acid is preferably 90 mol% or less of the total acid component. When it exceeds 90 mol%, the melting point of the polyester resin becomes too high, and it tends to be difficult to set polymerization conditions.

Examples of the other dicarboxylic acid include p-citric acid, 2,6-naphthalene dicarboxylic acid, meta-decanoic acid, diphenoxyethane dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, and 4 An aromatic dicarboxylic acid such as 4'-diphenylketone dicarboxylic acid; an aliphatic dicarboxylic acid such as adipic acid, sebacic acid, succinic acid, glutaric acid or dimer acid; An alicyclic dicarboxylic acid such as citric acid, hexahydrometacolic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid or 1,4-cyclohexanedicarboxylic acid Among these, from the viewpoint of polymerizability, cost, and heat resistance, it is preferably citric acid, 2,6-naphthalenedicarboxylic acid, or a mixture thereof. Further, a combination of a hydroxy acid such as p-hydroxybenzoic acid or hydroxycaproic acid, trimellitic acid, pyromellitic acid, benzophenone tetracarboxylic acid, diphenyltetracarboxylic acid, diphenyltetracarboxylic acid or the like is used in combination. The carboxylic acid and its anhydride are also irrelevant. The acid component constituting the polyester resin is preferably 80 mol% or more, more preferably 90 mol% or more, and 95 mol%, based on the total of 4,4'-biphenyldicarboxylic acid and another dicarboxylic acid. The above is better, 97% or more is particularly good, even if it is 100% by mole, it does not matter.

Moreover, examples of the diol component of the polyester resin include ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,2-butanediol, and 1, 3-butanediol, 2,3-butanediol, 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 Base-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-positive 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-nonanediol, 1,12-dodecanediol, triethylene glycol, polyethylene glycol, polytrimethylene Aliphatic diol such as diol, polytetramethylene glycol or polypropylene glycol, hydroquinone, 4,4'-dihydroxybisphenol, 1,4-bis(β-hydroxyethoxy)benzene, 1 ,4-bis(β-hydroxyethoxyphenyl)anthracene Bis (p-hydroxyphenyl) ether, bis (p-hydroxyphenyl) sulfone, bis (p-hydroxyphenyl) methane, 1,2-bis (p-hydroxyphenyl) ethane, bisphenol A, bis An aromatic diol such as an alkylene oxide adduct of phenol A. Among these, from the viewpoints of heat resistance, polymerizability, molding, cost, and the like, ethylene glycol, 1,4-cyclohexanedimethanol, 1,3-propanediol, neopentyl glycol, and 1, are preferably used. One or a mixture of two or more selected from the group consisting of 4-butanediol. More preferably, it is one or more selected from ethylene glycol and 1,4-butanediol. Further, in the case where ethylene glycol is used for the diol component, in the case of producing a polyester resin, diethylene glycol may be produced as a copolymerization component. In this case, the by-produced diethylene glycol is about 1 to 5 mol% with respect to ethylene glycol contained in the polyester resin according to the production conditions. Further, it is also possible to use a polyvalent polyol such as trimethylolethane, trimethylolpropane, glycerin or pentaerythritol.

When the polyester resin of the present invention is 200 mol% of the total constituent component, the total amount of the dicarboxylic acid component and the diol component is preferably 160 mol% or more, more preferably 180 mol%. The above is more preferably 190 mol% or more, and even 200 mol% (in this case, 100 mol% of the dicarboxylic acid component and 100 mol% of the diol component) may be used.

When the diol component of the polyester resin is ethylene glycol in all the amounts, the 4,4'-biphenyldicarboxylic acid as the acid component is preferably 63 mol% or more, and 70 mol% or more is more. good. Further, in this case, in order to achieve a more preferable high melting point, it is particularly preferable that the 4,4'-biphenyldicarboxylic acid as the acid component is 75 mol% or more, more preferably 80 mol% or more.

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

The catalyst to be used in the production of the polyester resin is not particularly limited, and at least one compound selected from the compounds of Ge, Sb, Ti, Al, Mn or Mg is preferably used. These compounds can be added to the reaction system as a slurry, an aqueous solution, a glycol solution, a slurry of ethylene glycol, or the like.

As the Ge compound, a slurry of amorphous ceria, crystalline cerium oxide powder or ethylene glycol, a solution obtained by heating and dissolving crystalline cerium oxide in water, or a B may be added thereto. a solution obtained by heat-treating a diol, etc., in particular, in order to obtain a polyester used in the present invention, a solution obtained by heating and dissolving cerium oxide in water or adding ethylene glycol thereto is preferably used. The solution should be heated. Further, a compound such as ruthenium tetroxide, ruthenium hydroxide, ruthenium oxalate, ruthenium chloride, tetraethoxy ruthenium, tetra-n-butoxy ruthenium or ruthenium phosphite can also be used. These polycondensation catalysts can be added during the esterification step. In the case of using a Ge compound, the amount of Ge remaining in the polyester is preferably from 10 to 150 ppm, more preferably from 13 to 100 ppm, even more preferably from 15 to 100 parts by mass based on the mass of the polyester resin. 70 ppm, preferably in the range of 15 to 50 ppm.

The Ti compound may, for example, be a tetraalkyl titanate such as tetraethyl titanate, tetraisopropyl titanate, tetra-n-propyl titanate or tetra-n-butyl titanate, or a part thereof. Hydrolyzate, titanium acetate, titanium oxytitanate, oxytitanium oxalate, sodium oxytitanate, potassium oxytitanate, calcium oxytitanate, oxytitanium oxalate, etc. Titanyl acid compound, titanium trimellitate, titanium sulfate, titanium chloride, hydrolyzate of titanium halide, titanium bromide, titanium fluoride, potassium hexafluorophosphate, ammonium hexafluorophosphate, titanium hexafluoride Cobalt acid, manganese hexafluoride, titanium acetylacetonate, titanium complex with hydroxypolycarboxylic acid or nitrogen-containing polycarboxylic acid, composite oxide composed of titanium and cerium or zirconium, titanium alkoxide and phosphorus A reaction product of a compound, a reaction product of a titanium alkoxide with an aromatic polycarboxylic acid or an anhydride thereof, and a specific phosphorus compound. The Ti compound is preferably added in an amount of 0.1 to 50 ppm, more preferably 0.5 to 10 ppm based on the mass of the polyester resin, in terms of the amount of Ti remaining in the produced polymer.

The Sb compound may, for example, be antimony trioxide, antimony acetate, barium tartrate, barium potassium tartrate, barium oxychloride, ethylene glycol hydrazine, ruthenium pentoxide or triphenylphosphonium. The Sb compound is a residual amount of Sb in the produced polymer, and is preferably 50 to 300 ppm, more preferably 50 to 250 ppm, still more preferably 50 to 200 ppm, most preferably 50 to 180 ppm, based on the mass of the polyester resin. The range is added.

Examples of the Al compound include inorganic acid salts such as aluminum acetate, basic aluminum acetate, aluminum chloride, aluminum hydroxide, aluminum hydroxide, aluminum carbonate, aluminum phosphate, and aluminum phosphonate, and aluminum n-propoxide and isopropyl chloride. Aluminum sulphate such as aluminum alkoxide, aluminum n-butoxide, aluminum aluminobutoxide, aluminum acetylate pyruvate, aluminum acetate, aluminum ethyl acetoacetate, aluminum ethyl acetoacetate An organoaluminum compound such as a compound, trimethylaluminum or triethylaluminum, or a partial hydrolyzate thereof, alumina or the like. Among these, it is particularly preferred to be aluminum acetate, alkaline aluminum acetate, aluminum chloride, aluminum hydroxide, aluminum chloride hydroxide and acetonitrile. Titanium acid. The aluminum compound is preferably from 5 to 200 ppm, more preferably from 10 to 100 ppm, still more preferably from 10 to 50 ppm, most preferably from 12 to 1 by mass based on the mass of the polyester resin. Add a range of 30 ppm.

Further, an alkali metal compound or an alkaline earth metal compound may be used in combination as needed. The alkali metal or alkaline earth metal is preferably at least one selected from the group consisting of Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, and Ba, and more preferably an alkali metal or a compound thereof. In the case of using an alkali metal or a compound thereof, Li, Na, and K are particularly preferably used.

Examples of the compound of the alkali metal and the alkaline earth metal include saturated aliphatic carboxylic acid salts such as formic acid, acetic acid, propionic acid, butyric acid, and oxalic acid; and unsaturated aliphatic compounds such as acrylic acid and methacrylic acid. a carboxylate; an aromatic carboxylate such as benzoic acid; a halogen-containing carboxylate such as trichloroacetic acid; a hydroxycarboxylic acid salt such as lactic acid, citric acid or salicylic acid; carbonic acid, sulfuric acid, nitric acid, phosphoric acid or phosphine Inorganic acid salts of acid, hydrogencarbonate, hydrogen phosphate, hydrogen sulfide, sulfurous acid, thiosulfuric acid, hydrochloric acid, hydrobromic acid, chloric acid, bromic acid, etc.; 1-propanesulfonic acid, 1-pentanesulfonic acid, naphthalenesulfonate An organic sulfonate such as an acid; an organic sulfate such as lauryl sulfate; an alkoxide such as a methoxy group, an ethoxy group, a n-propoxy group, an isopropoxy group, a n-butoxy group or a third butoxy group; And a compound, a hydride, an oxide, a hydroxide, etc. which are combined with an acetamidine salt or the like.

The aforementioned alkali metal compound or alkaline earth metal compound can be added to the reaction system as a powder, an aqueous solution, an ethylene glycol solution or the like. The alkali metal compound or the alkaline earth metal compound is preferably added in an amount of from 1 to 50 ppm based on the mass of the polyester resin in terms of the residual amount of the elements in the resulting polymer.

Furthermore, the polyester resin related to the present invention may further comprise: a group consisting of lanthanum, manganese, iron, cobalt, zinc, gallium, lanthanum, zirconium, hafnium, molybdenum, indium, tin, antimony, bismuth, and tungsten. a metal compound of at least one element selected from the group consisting of. Examples of the metal compound include a saturated aliphatic carboxylate such as an acetate of these elements, an unsaturated aliphatic carboxylate such as an acrylate, an aromatic carboxylate such as benzoic acid, or trichloroacetic acid. a halogen-containing carboxylate, a hydroxycarboxylate such as lactate, a mineral acid salt such as a carbonate, an organic sulfonate such as 1-propanesulfonate, or an organic compound such as lauryl sulfate. a compound such as a sulfate, an oxide, a hydroxide, a chloride, an alkoxide or an acetonide salt can be added to the reaction as a slurry, an aqueous solution, an ethylene glycol solution, or a slurry of ethylene glycol. In the system. The metal compound is preferably added in an amount of from 0.05 to 3.0 mol per 1 ton of the elemental residual amount of the metal compound. These metal compounds can be added at any stage of the aforementioned polyester formation reaction step.

Further, as the stabilizer, phosphoric acid esters such as phosphoric acid, polyphosphoric acid, and trimethyl phosphate are preferably used; a phosphonic acid compound, a phosphinic acid compound, a phosphine oxide compound, a phosphinic acid compound, and a sub-order. At least one phosphorus compound selected from the group consisting of a phosphonic acid compound and a phosphine compound. Specific examples include phosphoric acid, trimethyl phosphate, triethyl phosphate, tributyl phosphate, triphenyl phosphate, monomethyl phosphate, dimethyl phosphate, monobutyl phosphate, and phosphoric acid. Dibutyl ester, phosphorous acid, trimethyl phosphite, triethyl phosphite, tributyl phosphite, methylphosphonic acid, dimethyl methylphosphonate, dimethyl phosphinate Ester, dimethyl phenylphosphonate, diethyl phenylphosphonate, diphenyl phenylphosphonate, and the like. These stabilizers can be added to the esterification reaction step by a slurry mixing tank for citric acid and ethylene glycol. The phosphorus compound is preferably used in an amount of 5 to 100 ppm, more preferably 10 to 90 ppm, still more preferably 10 to 80 ppm, most preferably 20 to 70 ppm, based on the mass of the polyester resin. The range is added.

In the case where an aluminum compound is used as the polycondensation catalyst, it is preferred to use a phosphorus compound in combination, and it is preferred to use a solution or slurry obtained by mixing an aluminum compound and a phosphorus compound in a solvent in advance. In the case of the aluminum compound, a more preferable phosphorus compound is selected from the group consisting of a phosphonic acid compound, a phosphinic acid compound, a phosphine oxide compound, a phosphinic acid compound, a phosphinic acid compound, and a phosphine compound. At least one phosphorus compound. By using these phosphorus compounds, the effect of improving the catalytic activity can be observed, and the effect of improving the physical properties such as thermal stability of the polyester can be observed. Among these, when a phosphonic acid-based compound is used, the physical property improving effect and the catalytic activity are improved, which is preferable. Among the above-mentioned phosphorus compounds, when a compound having an aromatic ring structure is used, the effect of improving the physical properties and the effect of improving the catalytic activity are large, which is preferable.

Further, it is preferable that the above-mentioned catalyst, stabilizer, etc., a solution, a slurry, etc., at the time of preparation or blending, preferably have an oxygen concentration of 5 ppm or less, preferably 3 ppm or less, more preferably 2 ppm or less, and most preferably. The blunt gas of 1 ppm or less is foamed, or the same blunt gas can be circulated in the gas phase after foaming by a passive gas.

The acid value of the polyester resin of the present invention is preferably from 1 to 40 eq/ton. When the acid value exceeds 40 eq/ton, the light resistance tends to decrease. Moreover, when the acid value is less than 1 eq/ton, the polycondensation reactivity is lowered and the productivity tends to be deteriorated.

The melting point (Tm) of the polyester resin of the present invention in DSC measurement is 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 the Tm of the polyester resin of the present invention is preferably 340 ° C or lower for the following reasons. When the Tm exceeds the above upper limit, the processing temperature required for the injection molding of the composition using the polyester resin of the present invention is extremely high, so that the polyester resin is decomposed during processing, and the desired physical properties cannot be obtained. With the appearance of the situation. On the other hand, when the Tm is less than the lower limit, the crystallization rate is slow, and it is difficult to form the film in any case. Further, there is a fear that the solder heat resistance is lowered. If the Tm is 310 ° C or more, since the heat resistance of the reflow soldering at 280 ° C can be satisfied, it is preferable to be able to adapt even in the gold/tin eutectic soldering step.

Further, in the DSC measurement of the polyester resin of the present invention, the difference between the melting point (Tm) and the temperature-lowering crystallization temperature (Tc2) is preferably 40 ° C or lower, more preferably 35 ° C or lower, and most preferably 30 ° C or lower. The temperature crystallization temperature (Tc2) is a temperature at which crystallization starts when the temperature is lowered by a temperature higher than the melting point by 10 ° C or higher in the DSC measurement. The melting point (Tm) and the temperature-lowering crystallization temperature (Tc2) can be measured by the methods described in the items of the following examples. The difference between the melting point (Tm) and the temperature-lowering crystallization temperature (Tc2) is 40° C. or less, and crystallization is easily performed, 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 reflector for LED is molded by a short period of injection molding, and thus sufficient crystallization may not be performed. Since it is difficult to form a mold or the like, and it is not possible to sufficiently crystallize at the end, deformation and crystal shrinkage occur during heating in the subsequent step, which causes a problem of peeling off from the sealing material and the lead frame, and the reliability is insufficient.

The ultimate viscosity (IV) of the polyester resin of the present invention is preferably from 0.10 to 0.70 dl/g, more preferably 0.20 to 0.65 dl/g, further preferably 0.25 to 0.60 dl/g.

The polyester resin of the present invention has a high melting point and moldability, is excellent in balance between low water absorbability and fluidity, and is excellent in weather resistance. According to this, the polyester resin composition obtained from the polyester resin is suitable for heat resistance and crystallinity (formability) because it has a high melting point of 280 ° C or higher in the formation of the reflector of the surface mount type LED. A polyester resin composition of a reflector for a surface mount type LED which is excellent in heat yellowing resistance, weather resistance, and low water absorption.

The polyester resin of the present invention can be produced by a conventionally known production method. The acid component composed of 4,4'-biphenyldicarboxylic acid and another dicarboxylic acid can be directly reacted with the diol component, and the water can be distilled off and esterified, followed by polymerization under reduced pressure. a direct esterification method of condensation or reacting an acid component composed of dimethyl 4,4′-biphenyldicarboxylate and other dimethyl dicarboxylate with a diol component to distill off methanol and After the transesterification, the transesterification method of polycondensation under reduced pressure was carried out to carry out the production.

A material suitable for a surface mount LED reflector can be formed by blending titanium oxide, a reinforcing material, a non-fibrous or a non-needle filler into the polyester resin of the present invention to form a polyester resin composition. There is a tendency to increase mechanical strength and weather resistance via blending.

The titanium oxide is blended in order to increase the surface reflectance of the reflecting plate, and examples thereof include rutile-type and anatase-type titanium oxide (TiO ₂ ) and titanium oxide (TiO) produced by a sulfuric acid method and a chlorine method. Titanium trioxide (Ti ₂ O ₃ ) or the like is particularly preferably a rutile type titanium oxide (TiO ₂ ). The average particle diameter of the titanium oxide is generally in the range of 0.05 to 2.0 μm, preferably 0.15 to 0.5 μm, and one type may be used, or titanium oxide having a different particle diameter may be used in combination. The concentration of the titanium oxide component is 90% or more, preferably 95% or more, and more preferably 97% or more. Further, as the titanium oxide, a surface treatment can be carried out using a metal oxide such as vermiculite, alumina, zinc oxide or zirconium oxide, a coupling agent, an organic acid, an organic polyol, a decane or the like.

The proportion of the titanium oxide is preferably 0.5 to 100 parts by mass, more preferably 10 to 80 parts by mass, per 100 parts by mass of the polyester resin. If the ratio of titanium oxide is less than the above lower limit, the surface reflectance is lowered. When the above-mentioned upper limit is exceeded, there is a fear that the physical properties are greatly lowered and the formability such as a decrease in fluidity is lowered.

The reinforced material is blended to improve the formability of the polyester resin composition and the strength of the molded article, and at least one selected from the group consisting of a fibrous reinforcing material and a needle-shaped reinforcing material can be used. Examples of the fibrous reinforcing material include glass fiber, carbon fiber, boron fiber, ceramic fiber, and metal fiber. Examples of the needle-shaped reinforcing material include potassium titanate whisker, aluminum borate whisker, zinc oxide whisker, and carbonic acid. Calcium whiskers, magnesium sulfate whiskers, ashstones, etc. As the glass fiber, chopped strands or continuous long fiber 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, and more preferably 10 μm or less. Further, it is preferable that the physical surface and the fluidity are glass fibers having a non-circular cross section. The glass fiber having a non-circular cross section may include a cross section perpendicular to the longitudinal direction of the fiber length, which is slightly elliptical, slightly rounded, or slightly sinuous, and preferably has a flatness of 1.5 to 8. Here, the flatness is a rectangle having a minimum area circumscribing a cross section perpendicular to the longitudinal direction of the glass fiber, and the length of the long side of the rectangle is a long diameter, and the length of the short side is a long diameter. The ratio of the diameter to the short diameter. The thickness of the glass fiber is not particularly limited, and the short diameter is 1 to 20 μm and the long diameter is about 2 to 100 μm. Further, it is preferable to use a glass fiber which is formed into a fiber bundle and cut into a stranded felt having a fiber length of about 1 to 20 mm. In addition, in order to increase the surface reflectance of the polyester resin composition, the difference in refractive index from the copolymerized polyester resin is preferably large, and it is preferred to use a composition that changes the glass and a surface treatment to increase the refractive index.

The proportion of the reinforcing material is preferably from 0 to 100 parts by mass, more preferably from 5 to 100 parts by mass, even more preferably from 10 to 60 parts by mass, per 100 parts by mass of the polyester resin. Although the reinforcing material is not an essential component, if the ratio is 5 parts by mass or more, the mechanical strength of the molded article is preferably improved. When the ratio of the reinforcing material exceeds the above upper limit, the surface reflectance and the formability tend to be lowered.

Examples of the non-fibrous or non-needle-shaped fillers include reinforcing fillers, conductive fillers, magnetic fillers, flame-retardant fillers, thermally conductive fillers, and fillers for suppressing thermal yellowing, and specific examples thereof include glass beads. Granules, glass flakes, glass spheres, vermiculite, talc, kaolin, mica, alumina, hydrotalcite, montmorillonite, graphite, carbon nanotubes, fullerenes, 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 ash, potassium titanate, aluminum borate, magnesium sulfate, magnesium acetate, zinc oxide, calcium carbonate, and the like. These fillers can be used alone or in combination of several types. Among these, talc is preferred because it lowers Tc1 and improves formability. The amount of the filler to be added may be an optimum amount, and may be added in an amount of at most 50 parts by mass based on 100 parts by mass of the polyester resin, and is preferably 0.1 to 20 parts by mass from the viewpoint of mechanical strength of the resin composition. More preferably, it is 1 to 10 parts by mass. Further, in order to improve the affinity between the fibrous reinforcing material and the filler and the polyester resin, it is preferred to use a combination of an organic treatment and a coupling agent, or a coupling agent, and a coupling agent, and a coupling agent may be used as the coupling agent. Any one of a coupling agent, a titanate coupling agent, and an aluminum coupling agent is preferable to an amine decane coupling agent or an epoxy decane coupling agent.

Various additives of the conventional polyester resin composition for LED reflectors can be added to the polyester resin composition described above. Examples of the additive include a stabilizer, an impact-improving material, a flame retardant, a mold release agent, a slidability-improving material, a colorant, a fluorescent whitening agent, a plasticizer, a crystal nucleating agent, and a thermoplastic resin other than polyester. .

The polyester resin composition described above can be produced by blending the above-described respective constituent components by a conventionally known method. For example, a method in which each component is added during a polycondensation reaction of a polyester resin, a polyester resin and other components are dry blended, or a constituent component is melt-kneaded using a biaxial spiral type extruder may be mentioned.

[Examples]

Hereinafter, the present invention will be more specifically described by the examples, but the present invention is not limited to the examples. Further, the measured values described in the examples were measured by the following methods.

(1) Ultimate viscosity of polyester resin (IV)

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

(2) Acid price

After 0.1 g of polyester resin was dissolved in 10 ml of benzyl alcohol, a solution of 0.1 N NaOH was used. The alcohol/benzyl alcohol (1/9 volume ratio) solution was determined by titration.

(3) Melting point (Tm) of polyester resin and temperature of crystallization (Tc2)

It was measured by a differential thermal analyzer (DSC) manufactured by Seiko Instruments Inc., and RDC-220. The temperature was raised at a temperature increase rate of 20 ° C / min, and after maintaining at 330 ° C for 3 minutes, the temperature was lowered from 330 ° C to 130 ° C at 10 ° C / min. The apex temperature of the melting peak portion observed at the time of temperature rise was taken as the melting point (Tm), and the apex temperature of the crystallization peak portion observed at the time of temperature drop was taken as the temperature crystallization temperature (Tc2).

(4) Formability and dimensional stability

Using a Toshiba mechanical injection molding machine EC-100, the cylinder temperature was set to the melting point of the resin + 20 ° C, the mold temperature was set to 120 ° C, and a flat plate having a film gate of 100 mm in length, 100 mm in width, and 1 mm in thickness was used. Injection molding was carried out by using a mold. The molding was carried out at an injection speed of 50 mm/sec, a holding pressure of 30 MPa, an injection time of 10 seconds, and a cooling time of 10 seconds, and the moldability was evaluated as follows.

○: A molded article having no problem was obtained.

△: Sometimes the sprue remains on the mold.

X: The mold release property was insufficient, and the molded article was attached to the mold to be deformed.

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

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

The dimensional stability is evaluated as follows.

○: The dimensional change is less than 0.2%

×: The dimensional change amount is 0.2% or more

(5) Diffusion reflectivity

Using a Toshiba mechanical injection molding machine EC-100, the cylinder temperature was set to the melting point of the resin + 20 ° C, the mold temperature was set to 140 ° C, and a flat plate having a vertical length of 100 mm, a width of 100 mm, and a thickness of 2 mm was injection-molded to prepare a test piece for evaluation. . Self-scoring by Hitachi, Ltd. using this test piece An integrating sphere made by the same company was placed in the photometer "U3500", and the reflectance from a wavelength of 350 nm to 800 nm was measured. The comparative aspect of the reflectance is the diffuse reflectance at a wavelength of 460 nm. Barium sulfate is used for the reference.

(6) Solder heat resistance

Using a Toshiba mechanical injection molding machine EC-100, the cylinder temperature was set to the melting point of the resin + 20 ° C, the mold temperature was set to 140 ° C, and the test beads for the UL combustion test were formed with a molding length of 127 mm, a width of 12.6 mm, and a thickness of 0.8 mmt. Granules to make test pieces. The test piece was placed in an environment of 85 ° C and 85% RH (relative humidity) for 72 hours. The test piece was preheated to 190 ° C at a temperature increase rate of 0.5 ° C / min in a air reverberatory furnace (AIS-20-82C manufactured by Eightech), which was heated from room temperature to 150 ° C for 60 seconds and then subjected to preliminary heating. Then, the temperature was raised to a predetermined set temperature at a rate of 100 ° C/min, and the temperature was maintained at a predetermined temperature for 10 seconds, followed by cooling. The set temperature is raised from a temperature of 240 ° C at a pitch of 5 ° C, and the highest set temperature at which the surface is not expanded and deformed is used as a reflow heat resistance temperature, and is used as an index of solder heat resistance.

◎: Reflow heat resistance temperature is 280 ° C or higher

○: Reflow heat resistance temperature is 260 ° C or more and less than 280 ° C

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

(7) Saturated water absorption rate

Using a Toshiba mechanical injection molding machine EC-100, the cylinder temperature was set to the melting point of the resin + 20 ° C, the mold temperature was set to 140 ° C, and a flat plate having a vertical length of 100 mm, a width of 100 mm, and a thickness of 1 mm was injection-molded to prepare a test piece for evaluation. . The test piece was immersed in hot water at 80 ° C for 50 hours, and the saturated water absorption ratio was determined from the saturated water absorption time and the dry weight by the following formula.

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

(8) Liquidity

Using Toshiba mechanical injection molding machine IS-100, the cylinder temperature was set to 330 ° C, the mold temperature was set to 120 ° C, the injection pressure setting value was 40%, the injection speed setting value was 40%, the measurement was 35 mm, and the injection time was 6 seconds. The conditions for the cooling time of 10 seconds were injection-molded by a flow length measuring die having a width of 1 mm and a thickness of 0.5 mm to prepare a test piece for evaluation. As the evaluation of the fluidity, the measurement is made The flow length (mm) of the test piece.

(9) Polyoxymethylene adhesion

Using a Toshiba mechanical injection molding machine EC-100, the cylinder temperature was set to the melting point of the resin + 20 ° C, the mold temperature was set to 140 ° C, and a flat plate having a vertical length of 100 mm, a width of 100 mm, and a thickness of 2 mm was injection-molded to prepare a test piece for evaluation. . A polyfluorene sealant (manufactured by Shin-Etsu Chemical Co., Ltd., ASP-1110, sealant hardness D60) was applied to one side of the test piece so as to have a coating thickness of about 100 μm, and after preheating at 100 ° C for 1 hour. The 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 adhesion of the sealing material film on the test piece was evaluated by a checkerboard test (100 mm in a 1 mm width) based on JIS K5400.

○: The number of stripped grids is 10 or less

×: peeling occurred when the lattice was formed before the peeling test

(10) Light resistance

Using a Toshiba mechanical injection molding machine EC-100, the cylinder temperature was set to the melting point of the resin + 20 ° C, the mold temperature was set to 140 ° C, and a flat plate having a vertical length of 100 mm, a width of 100 mm, and a thickness of 2 mm was injection-molded to prepare a test piece for evaluation. . The test piece was subjected to UV irradiation at an illumination of 50 mW/cm ² in an environment of 63 ° C and 50% RH using an ultra-promoted weathering tester "EYE SUPER UV TESTER SUV-F11". The light reflectance of the test piece at a wavelength of 460 nm was measured before irradiation and after 60 hours of irradiation. The retention of the light reflectance of the test piece after the irradiation was evaluated based on the following criteria with respect to the light reflectance of the test piece before the irradiation.

○: The retention rate is 90% or more

△: The retention rate is less than 90% to 85% or more

×: The retention rate is less than 85%

(11) Heat-resistant yellowing

Using a Toshiba mechanical injection molding machine EC-100, the cylinder temperature was set to the melting point of the resin + 20 ° C, the mold temperature was set to 140 ° C, and a flat plate having a vertical length of 100 mm, a width of 100 mm, and a thickness of 2 mm was injection-molded to prepare a test piece for evaluation. . Use this test piece at 150 ° C in a hot air dryer After 2 hours, the yellowing was confirmed visually.

○: no change

△: There are several yellowing

×: There is yellowing

<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 phthalate, and 3 times the molar amount of the acid component were fed. After ethylene glycol, 2 g of manganese acetate, and 0.86 g of cerium oxide were subjected to transesterification, the temperature was raised to 300 ° C in 60 minutes, and the pressure of the reaction system was gradually lowered to 13.3 Pa (0.1 Torr). The polycondensation reaction was carried out at 310 ° C and 13.3 Pa. The pressure was gradually released, and the resin under slight pressure was spouted into a thin strip and 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 polyester had an ultimate viscosity of 0.60 dl/g, and the resin composition was measured by ¹ H-NMR, which was 65 mol% for 4,4'-biphenyldicarboxylic acid and 35 mol% for tannic acid. Ethylene glycol was 98.2 mol% and diethylene glycol was 1.8 mol%. The characteristic values and the like 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 the raw materials used were changed. The characteristic values and the like of each of the obtained polyester resins are shown in Table 1. In addition, diethylene glycol is produced by the 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 phthalate, and 3 times the molar amount of the acid component were fed. After ethylene glycol, 2 g of manganese acetate, and 0.86 g of cerium oxide were subjected to transesterification, 8 g of high-purity citric acid was added, and after heating for 300 minutes to 300 ° C, the pressure of the reaction system was gradually lowered to 13.3. Pa (0.1 Torr), and a polycondensation reaction was carried out at 310 ° C and 13.3 Pa. The pressure was gradually released, and the resin under slight pressure was spouted into a thin strip in water and cooled, and then cut by a cutter to obtain a cylindrical pellet having a length of about 3 mm and a diameter of about 2 mm. The obtained polyester had an ultimate viscosity of 0.60 dl/g, the resin composition was determined by ¹ H-NMR, 4,4'-biphenyldicarboxylic acid was 65 mol%, and p-citric acid was 35 mol%, B. The diol was 98.2 mol% and the diethylene glycol was 1.8 mol%. The characteristic values and the like of the obtained polyester resin are shown in Table 1.

(Comparative Synthesis Example 1)

In a 20 liter stainless steel autoclave with a stirrer, feed high purity p-citric acid with 2 times the molar amount of ethylene glycol, adding 0.3 mol% triethylamine relative to the acid component, at 0.25 MPa The water was distilled off at 250 ° C under pressure while performing an esterification reaction to obtain a mixture of bis(2-hydroxyethyl)-p-citric acid and an oligomer having an esterification ratio of about 95% (hereinafter referred to as BHET). mixture). As the polymerization catalyst, cerium oxide (Ge was 100 ppm) was added to the BHET mixture, followed by stirring at 250 ° C for 10 minutes under a nitrogen atmosphere. Then, the temperature was raised to 280 ° C for 60 minutes while the pressure of the reaction system was gradually lowered to 13.3 Pa (0.1 Torr), and the polycondensation reaction was carried out at 280 ° C and 13.3 Pa. The pressure was gradually released, and the resin under slight pressure was spouted into a thin strip and cooled, and then cut by a cutter to obtain a cylinder-shaped 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 measured by ¹ H-NMR, and was 100 mol% for citric acid, 98.0 mol% for ethylene glycol, and 2.0 mol% for diethylene glycol. The characteristic values and the like of the obtained polyester resin are shown in Table 2.

(Comparative Synthesis Example 2~4)

The 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 the raw material to be used was changed. The characteristic values and the like of each of the obtained polyester resins are shown in Table 2.

(Comparative Synthesis Example 5: Polyamide resin)

3272.9g (19.70 moles) of citric acid, 2849.2g (18.0 moles) of 1,9-nonanediamine, 316.58g (2.0 moles) of 2-methyl-1,8-octanediamine, 73.27 of benzoic acid g (0.60 mol), 6.5 g of sodium hypophosphite monohydrate (0.1% by weight relative to the raw material), and 6 liters of distilled water were placed in an autoclave having an internal volume of 20 liters, and replaced with nitrogen. After stirring at 100 ° C for 30 minutes, the internal temperature was raised to 210 ° C for 2 hours. At this time, the autoclave was pressurized to 22 kg/cm ² . After continuing the reaction for 1 hour, the temperature was further raised to 230 ° C, and then the temperature was maintained at 230 ° C for 2 hours, and the water vapor was gradually released and the pressure was maintained at 22 kg / cm ² while reacting. Next, the pressure was lowered to 10 kg/cm ^{2 for} 30 minutes, and the reaction was further carried out for 1 hour to obtain a prepolymer having an ultimate 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 subjected to solid phase polymerization at 230 ° C and 0.1 mmHg for 10 hours to obtain a white polyamine having a melting point of 310 ° C, an ultimate viscosity [η] of 1.33 dl / g, and a terminal blocking ratio of 90%.

(Examples 1 to 8 and Comparative Examples 1 to 5)

Using the polyester resin and the polyamide resin obtained in the above synthesis examples and comparative synthesis examples, a Cooperion biaxial extruder STS-35 was used in the ratio of the components and mass ratios shown in Tables 3 and 4 to The resin was melt-kneaded at a melting point of +15 ° C to obtain a resin composition for evaluation. The materials used in Tables 3 and 4 other than the resin are as follows.

Titanium oxide: TIPAQUE CR-60, rutile TiO ₂ manufactured by Ishihara Industry Co., Ltd.

Reinforced material with an average particle diameter of 0.2 μm: glass fiber (Japan East Textile Co., Ltd., CS-3J-324)

Release agent: magnesium stearate

Stabilizer: pentaerythritol. Tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] (Ciba Specialty Chemicals, IRGANOX 1010)

The polyester resin composition and the polyamide resin composition obtained in Examples 1 to 8 and Comparative Examples 1 to 5 were evaluated for various characteristics. The results are shown in Tables 3 and 4.

It can be seen from Tables 1 and 3 that in the case where the melting point of the polyester resin measured by DSC is 280 ° C or higher, it can be adapted to the reflow step, and when the melting point exceeds 310 ° C, the reflow heat resistance temperature is 280 ° C or more, and the display is also It can be adapted to the solder heat resistance of the gold/tin eutectic soldering step, and it is confirmed that the important characteristics in the LED application, that is, the adhesion to the sealing material and the surface reflectance are excellent, and the formability, fluidity, and dimensional stability are further improved. The low water absorption and light resistance are also excellent special effects. On the other hand, as can be seen from Tables 2 and 4, the comparative examples cannot fully satisfy these characteristics. Although the polyamide resin of Comparative Example 5 has a high melting point, it has a water absorption property due to the guanamine structure, and therefore cannot satisfy the reflow heat resistance temperature of 280 ° C or higher.

[Industrial use possibilities]

When the polyester resin of the present invention is used as a material for a surface-mounted LED reflector, it has excellent moldability and solder heat resistance at the time of injection molding in addition to high heat resistance and low water absorption. Processability, can highly satisfy the necessary characteristics, and industrially can help Surface mount LED reflectors.

Claims (6)

A polyester resin for a surface-mounted LED reflector, characterized in that an acid component composed of 4,4'-biphenyldicarboxylic acid and another dicarboxylic acid, and a diol component are used as constituent components, and The melting point is 280 ° C or more. The polyester resin for a surface mount type LED reflector according to the first aspect of the invention, wherein 30 mol% or more of all the acid components constituting the polyester resin is 4,4'-biphenyldicarboxylic acid. A polyester resin for a surface mount type LED reflector according to claim 1 or 2, wherein the other dicarboxylic acid constituting the polyester resin is p-citric acid and/or 2,6-naphthalene dicarboxylic acid. The polyester resin for surface mount type LED reflectors according to any one of claims 1 to 3, wherein 30 to 90 mol% of all acid components constituting the polyester resin is 4,4'-biphenyl a carboxylic acid, the other dicarboxylic acid is a tereic acid and/or 2,6-naphthalenedicarboxylic acid, and the diol component is selected from the group consisting of ethylene glycol, 1,4-cyclohexanedimethanol, and 1,3-propanediol. One or more of neopentyl glycol and 1,4-butanediol. The polyester resin for a surface mount type LED reflector according to any one of claims 1 to 4, wherein a difference between a melting point (Tm) and a temperature-lowering crystallization temperature (Tc2) of the polyester resin is 40 ° C or less. The polyester resin for a surface mount type LED reflector according to any one of claims 1 to 5, wherein the polyester resin has an acid value of 1 to 40 eq/t.