JP6690530B2 - Infrared light transmitting polyester resin composition - Google Patents

Description

  The present invention relates to a polyester resin composition having excellent infrared light transmittance, good heat resistance, and low gas properties, which is suitable for use as a design member (particularly a lamp member).

  Polybutylene terephthalate resin is widely used as an injection molded product in the fields of automobile parts, mechanical parts, electric / communication parts, etc. by utilizing its excellent injection moldability, mechanical properties, heat resistance, electrical properties, chemical resistance, etc. It's being used. Furthermore, it has excellent mold transferability, and is suitable for use as a lamp member for automobile extensions and the like, which requires a particularly good appearance. Further, from the use, it is necessary to highly control the heat resistance of the resin and the suppression of gas generation (low gas property) during molding.

  On the other hand, in recent years, LED lights have been mounted on headlamps of high-end cars and the like, and the lamp design has begun to be renewed. For example, in the reflector type (reflecting the light from the light source and irradiating it with a reflector), it is necessary to vapor-deposit aluminum in the area immediately adjacent to the light source, but with the projector type (light from the light source is focused and emitted to the front lens) Some designs have been changed, and the part closest to the light source has been designed to be black-dyed. However, due to this change, when the sunlight is reflected by the projector lens and the light is condensed on the surrounding black part, it will be scratched due to the condensing part becoming extremely hot. Light problems began to occur (this phenomenon has been known for a long time, but it has not been a problem so far due to the lamp design). In response to this problem, there is a demand for a material that transmits infrared light that does not reach a high temperature even when sunlight is condensed, and a material that has heat resistance and that is not scratched even at a high temperature.

  As a technique for transmitting infrared light, for example, in Patent Documents 1 to 3, resins made of polybutylene terephthalate or polybutylene terephthalate and polybutylene terephthalate copolymers, and polycarbonate resins, styrene acrylonitrile resins, 1,4-cyclohexanediene are disclosed. A resin composition prepared by blending an amorphous resin such as a polyester resin containing a methanol component is disclosed. However, although these techniques are useful for increasing the infrared light transmittance of the polybutylene terephthalate-based resin, the addition of the amorphous resin significantly lowers the heat distortion temperature, so that it is particularly useful as a lamp member application. Difficult to use.

  As a technique for obtaining a black primary coating polyester resin composition that suppresses a temperature rise due to solar radiation, for example, Patent Document 4 discloses a polyethylene terephthalate resin composition containing a pigment that does not contain carbon black but is blackened by toning. It is disclosed. According to the present invention, by using a non-carbon black pigment, it is possible to lower the temperature corresponding to the amount of heat stored due to the infrared light absorption of carbon black, but the effect of suppressing the temperature rise is small, which is a great improvement. There is room.

  On the other hand, a technique has been disclosed in which an alkali metal salt of an aliphatic carboxylic acid is added to polyester in order to enhance infrared light transmittance (see, for example, Patent Document 5). Although it is possible to increase infrared light transmission with this technology, the composition of this technology allows bleed-out and mold stains during injection molding due to alkali metal salts of aliphatic carboxylic acids and their decomposition products. Etc. is very likely to be a problem.

JP, 2004-315805, A Japanese Patent No. 5034217 JP, 2008-106217, A JP, 2014-125588, A Japanese Patent Publication No. 2014-512420

  The present invention has been made against the background of the problems of the related art. That is, an object of the present invention is to provide a polyester resin composition having excellent infrared light transmittance, good heat resistance, and low gas properties, which is suitable for use as a design member (particularly a lamp member). is there.

That is, the present invention has the following configurations.
[1] 0.1 to 1 part by mass of an organic carboxylic acid alkali metal salt having 3 to 40 carbon atoms (B) and a polyfunctional glycidyl group-containing styrene-based polymer (C) with respect to 100 parts by mass of the polyester resin (A). A polyester resin composition containing 0.05 to 3 parts by mass, wherein the polyester resin composition satisfies the following requirements (1) and (2).
(1) The average value of the transmittance at a wavelength of 800 to 1100 nm of a flat plate having a thickness of 2 mm obtained from the polyester resin composition is 20% or more and 75% or less (2) The heat distortion temperature (0.45 MPa) is It is 150 ° C. or higher [2] The polyester resin (A) contains the polybutylene terephthalate resin (a) and the polyethylene terephthalate resin (b) at a mass ratio of 100: 0 to 50:50 [ 1] The polyester resin composition according to item 1.
[3] The metal constituting the organic carboxylic acid alkali metal salt (B) having 3 to 40 carbon atoms is one or more selected from lithium, sodium, and potassium [1] Alternatively, the polyester resin composition according to [2].
[4] The organic carboxylic acid forming the organic carboxylic acid alkali metal salt (B) having 3 to 40 carbon atoms is an aliphatic carboxylic acid having 3 to 20 carbon atoms, [1] to [3] ] The polyester resin composition in any one of these.
[5] A flat plate containing a colorant (D) and having a thickness of 2 mm obtained from the polyester resin composition has a transmittance of substantially 0% at a wavelength of 300 to 700 nm [1] to The polyester resin composition according to any one of [4].
[6] The polyester resin composition according to [5], which contains a colorant (D) and the polyester resin composition satisfies the following requirement (3).
(3) Color-L ≦ 7
[In the above formula, Color-L represents the hue L ^* value of the CIE color difference system L ^* a ^* b ^* system of the polyester resin composition. ]
[7] A lamp component molded using the polyester resin composition according to any one of [1] to [6].

  One of the characteristics of the polyester resin composition of the present invention is that the infrared light transmittance is dramatically improved while maintaining high crystallinity. Therefore, good heat resistance (high heat distortion temperature) can be realized without adding a reinforcing filler such as talc, and both high infrared light transmittance and excellent heat resistance can be achieved. Further, since it is possible to obtain a resin molded body in which gas generation is highly controlled, it is possible to reduce fouling resistance and to reduce mold stains during injection molding.

  Hereinafter, the present invention will be described in detail.

[Polyester resin (A)]
The polyester resin (A) usable in the present invention is preferably a polyester resin having a dicarboxylic acid component and a diol component as constitutional units.
As the dicarboxylic acid component, those containing an aromatic dicarboxylic acid as a main component are preferable. The main component is usually 70 mol% or more, preferably 80 mol% or more, more preferably 90 mol% or more, particularly preferably 95 mol% or more, based on all dicarboxylic acid units. Besides the aromatic dicarboxylic acid, an aliphatic dicarboxylic acid can be used.

As aromatic dicarboxylic acids, terephthalic acid, isophthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2, Aroma such as 7-naphthalenedicarboxylic acid, diphenyl-4,4'-dicarboxylic acid, 4,4'-biphenyl ether dicarboxylic acid, 1,2-bis (phenoxy) ethane-p, p'-dicarboxylic acid and anthracene dicarboxylic acid Group dicarboxylic acids are mentioned, and among these, terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid are preferable.
Specific examples of the aliphatic dicarboxylic acid include oxalic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, dodecanedioic acid, dimer acid and cyclohexanedicarboxylic acid, which usually have 2 to 40 carbon atoms. A chain or alicyclic dicarboxylic acid may be mentioned.
The above dicarboxylic acid components may be used alone or in combination of two or more.
In addition to the dicarboxylic acid component and the diol component, a hydroxycarboxylic acid component or a lactone component may be copolymerized. The amount used is preferably 30 mol% or less, more preferably 20 mol% or less, and further preferably 10 mol% or less, based on all the monomer components.

  Examples of the diol component include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5. -Pentanediol, 2-methyl-1,5-pentanediol, 2,2-diethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,9-nonanediol, 1,10-decanediol, 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,2-cyclohexanedimethanol and the like can be mentioned. Among these, ethylene glycol, 1,3-propanediol and 1,4-butanediol are preferable.

Examples of preferable polyester resin (A) include polybutylene terephthalate, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene naphthalate, and polyethylene naphthalate.
The polyester resin (A) preferably has an intrinsic viscosity (IV) of 0.36 to 1.60 dl / g when measured in an o-chlorophenol solution at 25 ° C., and 0.52 to 1.25 dl. / G is more preferable, 0.58 to 1.12 dl / g is further preferable, and 0.62 to 1.02 dl / g is most preferable. Is. When the intrinsic viscosity of (A) is 0.36 to 1.60 dl / g, the mechanical properties and moldability of the polyester resin composition of the present invention will be good.
In the present invention, it is preferable to contain the polybutylene terephthalate resin (a) and the polyethylene terephthalate resin (b) in a specific blending amount.
In the present invention, it is also preferable to use a polytrimethylene terephthalate resin (c) or a polybutylene naphthalate resin (d) as the polyester resin (A). In that case, the polytrimethylene terephthalate resin (c) can be used as a substitute for the polyethylene terephthalate resin (b), and the polybutylene naphthalate resin (d) can be used as a substitute for the polybutylene terephthalate resin (a). is there.

  The polybutylene terephthalate resin (a) that can be used in the present invention includes a polycondensation reaction containing terephthalic acid or its ester-forming derivative and 1,4-butanediol or its ester-forming derivative as main components. It is a polymer obtained by a general polymerization method. The polymer is preferably 80 mol% or more of butylene terephthalate repeating units, more preferably 90 mol% or more, even more preferably 95 mol% or more, and most preferably 100 mol% of butylene terephthalate repeating units. Other copolymer components may be contained within a range that does not impair the characteristics, for example, about 20% by mass or less. Examples of the copolymer include polybutylene (terephthalate / isophthalate), polybutylene (terephthalate / adipate), polybutylene (terephthalate / sebacate), polybutylene (terephthalate / decanedicarboxylate), polybutylene (terephthalate / naphthalate), poly (butylene). / Ethylene) terephthalate and the like may be used, and they may be used alone or in combination of two or more kinds.

  The polybutylene terephthalate resin (a) that can be used in the present invention preferably has an intrinsic viscosity (IV) of 0.36 to 1.60 dl / g when an o-chlorophenol solution is measured at 25 ° C. Yes, those in the range of 0.52 to 1.25 dl / g are more preferable, those in the range of 0.58 to 1.12 dl / g are more preferable, and 0.62 to 1.02 dl / g Those in the range of g are most preferred. When the intrinsic viscosity of (a) is 0.36 to 1.60 dl / g, the polyester resin composition of the present invention has good mechanical properties and moldability.

  The polybutylene naphthalate resin (d) that can be used in the present invention is also the same as the polybutylene terephthalate resin (a).

  The polyethylene terephthalate resin (b) that can be used in the present invention is obtained by a usual polymerization method such as polycondensation reaction of terephthalic acid or its ester-forming derivative and ethylene glycol or its ester-forming derivative as main components. The resulting polymer. The ethylene terephthalate repeating unit is preferably a polymer having 80 mol% or more, the ethylene terephthalate repeating unit is more preferably 90 mol% or more, further preferably 95 mol% or more, and most preferably 100 mol%. Other copolymer components may be contained within a range that does not impair the characteristics, for example, about 20% by mass or less. Examples of copolymers include polyethylene (terephthalate / isophthalate), polyethylene (terephthalate / adipate), polyethylene (terephthalate / sebacate), polyethylene (terephthalate / decanedicarboxylate), polyethylene (terephthalate / naphthalate), poly (ethylene). / Cyclohexanedimethyl) / terephthalate, poly (butylene / ethylene) terephthalate, etc. may be used alone or in combination of two or more. By using the above polyethylene terephthalate resin (b), the molding shrinkage of the resin composition can be controlled.

  The polyethylene terephthalate resin (b) that can be used in the present invention preferably has an intrinsic viscosity (IV) of 0.36 to 1.60 dl / g when an o-chlorophenol solution is measured at 25 ° C. , 0.45 to 1.35 dl / g is more preferable, 0.50 to 1.20 dl / g is further preferable, 0.55 to 1.05 dl / g. Those within the range are most preferable. When the intrinsic viscosity of (b) is 0.36 to 1.60 dl / g, the polyester resin composition of the present invention has good mechanical properties and moldability.

  The polytrimethylene terephthalate resin (c) that can be used in the present invention is the same as the polyethylene terephthalate resin (b).

In the present invention, the polybutylene terephthalate resin (a) and the polyethylene terephthalate resin (b) are blended in a mass ratio ((a) :( b)) of (a) and (b) of 100: 0 to 50:50. Is preferred. More preferably (a) :( b) = 100: 0 to 60:40, further preferably (a) :( b) = 100: 0 to 70:30, and particularly preferably (a) :( b) = 100. : 0 to 80:20, and most preferably (a) :( b) = 100: 0 to 90:10. By blending the polyethylene terephthalate resin (b), it is possible to control the molding shrinkage of the resin composition, but if the blending amount exceeds 50 parts by mass, the releasability of the resin composition during injection molding may deteriorate. Since the heat resistance of the resin decreases and the crystallization rate of the polyester resin composition slows, crystallization gradually progresses in a temperature environment in the range of 100 ° C to 200 ° C, and infrared light is gradually transmitted. There is a case where the sex is deteriorated.
In the present invention, the total amount of the polybutylene terephthalate resin (a) and the polyethylene terephthalate resin (b) in the polyester resin (A) is preferably 80% by mass or more, more preferably 90% by mass or more, and 95% by mass or more. Is more preferable, and may be 100% by mass.

  In the above description of the blending amount, "polybutylene terephthalate resin (a)" means "at least one of polybutylene terephthalate resin (a) and polybutylene naphthalate resin (d)" and "polyethylene terephthalate resin (b)". , "At least one of polyethylene terephthalate resin (b) and polytrimethylene terephthalate resin (c)".

[Alkali metal salt of organic carboxylic acid having 3 to 40 carbon atoms (B)]
The polyester resin composition of the present invention contains 0.1 to 1 part by mass of an organic carboxylic acid alkali metal salt (B) having 3 to 40 carbon atoms with respect to 100 parts by mass of the polyester resin (A).
When the organic carboxylic acid alkali metal salt (B) is less than 0.1 part by mass, the infrared light transmittance of the polyester resin composition tends to be lowered. When the organic carboxylic acid alkali metal salt (B) is blended in an amount of more than 1 part by mass, the catalytic action of the alkali metal salt causes the polyester resin composition to be significantly decomposed, resulting in a decrease in molecular weight and mechanical strength. The blending amount of the organic carboxylic acid alkali metal salt (B) is preferably 0.1 to 0.7 parts by mass, and 0.15 to 0.5 parts by mass with respect to 100 parts by mass of the polyester resin (A). Is more preferable.

The alkali metal salt of an organic carboxylic acid having 3 to 40 carbon atoms (B) used in the present invention is an alkali metal salt of an aliphatic, alicyclic or aromatic carboxylic acid having 3 to 40 carbon atoms. As the alkali metal, sodium, potassium and lithium are preferable.
An aliphatic carboxylic acid is a compound in which a linear or branched aliphatic group has a carboxyl group, and a part of the bond is an unsaturated group, an alicyclic group, an aromatic group or a hydroxyl group, a phosphoric acid ester group. It may have other substituents such as

  Among the aliphatic carboxylic acids, propionic acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, mistyric acid, palmitic acid, margaric acid, stearic acid, oleic acid, linoleic acid, Montanic acid and the like are preferable, and among the alkali metal salts, sodium salt is preferable in terms of solubility in polyester resin and good crystal nucleation property.

  The organic carboxylic acid that constitutes the alkali metal salt of an organic carboxylic acid having 3 to 40 carbon atoms (B) is an aliphatic carboxylic acid having 3 to 20 carbon atoms from the viewpoint of meltability and compatibility with the polyester resin. It is more preferably an aliphatic carboxylic acid having 6 to 20 carbon atoms. Among these, the aliphatic carboxylic acid metal salt having less than 14 carbon atoms is preferable in that the infrared light transmittance can be improved with a small amount of the compound.

Although the details of the infrared light transmittance improving effect of the organic carboxylic acid alkali metal salt (B) are not clear, the differential scanning calorific value of the composition of the polyester resin (A) and the organic carboxylic acid alkali metal salt (B) is not clear. As a result of the analysis (DSC), the crystallization peak at the time of cooling was shifted to the high temperature side to be sharper than that of the polyester resin (A) alone, and the organic carboxylic acid was detected in the composition. Is estimated as.
That is, the behavior of the DSC means that the crystallization rate is high and the crystal size is uniform. Therefore, it is considered that the organic carboxylic acid alkali metal salt (B) acts as a crystal nucleating agent on the polyester resin (A) to form microcrystals having a uniform size, thereby increasing the infrared light transmittance. Further, the organic carboxylic acid alkali metal salt (B) changes the carboxyl group of the polyester resin (A) into an alkali metal base by an ion exchange reaction, lowers the mobility of the molecular chain end, and inhibits further crystallization, It is considered that the organic carboxylic acid is liberated as the ion exchange reaction proceeds.

  The organic carboxylic acid alkali metal salt (B) can effectively improve infrared light transmissivity with a small amount of the compound, as compared with alkali metal salts other than organic carboxylic acid-based alkali metal salts. This is because the organic carboxylic acid alkali metal salt (B) has a relatively small molecular weight, so that when the same mass parts are added, the number of molecules increases and crystallization easily occurs, and the molecular size is relatively small. Therefore, it is considered that this is due to the fact that the crystal size of the polyester resin (A) generated by using this as a crystal nucleus becomes small (that is, the crystal is hard to grow and finely crystallizes).

  The organic carboxylic acid alkali metal salt (B) may be used in combination of two or more kinds. The combined use of the one having 3 or more and less than 14 carbon atoms and the one having 14 or more carbon atoms is preferable because the solubility of the one having 3 or more and less than 14 carbon atoms is improved and the infrared light transmittance is easily improved.

[Polyfunctional glycidyl group-containing styrene polymer (C)]
The polyester resin composition of the present invention contains 0.05 to 3 parts by mass of a polyfunctional glycidyl group-containing styrene-based polymer (C) per 100 parts by mass of the polyester resin (A).
By setting the polyfunctional glycidyl group-containing styrene-based polymer (C) in this range, the thickening effect and the trapping effect of the liberated organic carboxylic acid and other gasification components can be efficiently exhibited. At the time of kneading, the melt viscosity is increased by the thickening effect and the shear stress is increased, so that the dispersion of the organic carboxylic acid alkali metal salt (B) can be promoted. Further, the thickening effect hinders the growth of crystals, which makes it possible to promote microcrystallization by the alkali metal salt of an organic carboxylic acid (B). Furthermore, excellent low gas properties can be realized due to the trapping effect of gasifying components such as organic carboxylic acids that are released.
When the amount of the styrenic polymer (C) containing a polyfunctional glycidyl group is more than 3 parts by mass, gelation may occur due to the reaction with the polyester resin (A), or the infrared light transmissivity may decrease due to compatibility problems. . Further, if the polyfunctional glycidyl group-containing styrene-based polymer (C) is less than 0.05 parts by mass, the dispersion of the organic carboxylic acid alkali metal salt (B) will be non-uniform, or the releasing organic carboxylic acid trapping effect will be obtained. It may become smaller and impair low gas properties. The amount of the polyfunctional glycidyl group-containing styrene-based polymer (C) to be blended is preferably 0.1 to 3 parts by mass, and 0.15 to 2 parts by mass, relative to 100 parts by mass of the polyester resin (A). It is more preferably 0.2 to 1 part by mass, further preferably 0.2 to 0.7 parts by mass.

The polyfunctional glycidyl group-containing styrene-based polymer (C) used in the present invention is preferably one that has good compatibility with the polyester resin (A) and has a small difference in refractive index from the polyester resin (A). The weight average molecular weight (Mw) is preferably 1000 or more, and the epoxy value is preferably 0.5 meq / g or more, more preferably 1.0 meq / g or more.
As a specific component of the polyfunctional glycidyl group-containing styrene polymer (C), a copolymer of a glycidyl group-containing unsaturated monomer and a vinyl aromatic monomer is preferable.

  Examples of the glycidyl group-containing unsaturated monomer include unsaturated carboxylic acid glycidyl ester, unsaturated glycidyl ether, and the like, and examples of the unsaturated carboxylic acid glycidyl ester include glycidyl acrylate, glycidyl methacrylate, and monoglycidyl itaconic acid. Examples thereof include esters, but glycidyl methacrylate is preferable. Examples of unsaturated glycidyl ethers include vinyl glycidyl ether, allyl glycidyl ether, 2-methylallyl glycidyl ether, and methacryl glycidyl ether, with methacryl glycidyl ether being preferred.

  Examples of the vinyl aromatic-based monomer include styrene-based monomers such as styrene, methylstyrene, dimethylstyrene, and ethylstyrene, with styrene being preferred.

The copolymerization ratio of the glycidyl group-containing unsaturated monomer and the vinyl aromatic monomer is such that the copolymerization amount of the glycidyl group-containing unsaturated monomer is preferably 1 to 30% by mass, and more preferably Is 2 to 20% by mass.
When the copolymerization amount of the glycidyl group-containing unsaturated monomer is less than 1% by mass, the crystallinity-inhibiting effect is small and sufficient infrared light transmission cannot be obtained, and the capturing effect of the released organic carboxylic acid becomes small, It tends to adversely affect low gas properties. If it exceeds 30% by mass, the stability as a resin composition may be impaired.

  As long as the compatibility with the polyester resin (A) is not impaired, alkyl esters of acrylic acid or methacrylic acid having 1 to 7 carbon atoms, such as methyl, ethyl, propyl, isopropyl, and butyl esters of (meth) acrylic acid ( (Meth) acrylic acid ester monomers, (meth) acrylonitrile monomers, vinyl acetate monomers such as vinyl acetate and vinyl propylate, (meth) acrylamide monomers, maleic anhydride, monoesters of maleic acid, A monomer such as diester may be copolymerized. However, since α-olefins such as ethylene, propylene and butene-1 tend to impair the compatibility with the polyester resin (A), those not copolymerized are preferable.

  The polyfunctional glycidyl group-containing styrene polymer (C) is preferably a polyfunctional glycidyl styrene acrylic polymer having a weight average molecular weight (Mw) of 1,000 or more and an epoxy value of 0.5 meq / g or more. At this time, the weight average molecular weight (Mw) is more preferably 5,000 or more, further preferably 7,000 or more, and particularly preferably 8,000 or more. If the weight average molecular weight (Mw) is less than 1000, the number of glycidyl groups per molecule decreases, and the effect of capturing the released organic carboxylic acid decreases, which is not preferable. The weight average molecular weight (Mw) is preferably 50,000 or less from the viewpoint of compatibility with the polyester resin (A). Further, the epoxy value is more preferably 0.6 meq / g or more, further preferably 0.65 meq / g or more. If the epoxy value is less than 0.5 meq / g, the effect of capturing the released organic carboxylic acid will be low, which is not preferable. The epoxy value is preferably 3 meq / g or less from the viewpoint of suppressing excessive reaction with the polyester resin (A).

Since the polyester resin composition of the present invention has the above-mentioned constitution, the average value of the transmittance at a wavelength of 800 to 1100 nm of the flat plate having a thickness of 2 mm obtained from the polyester resin composition is 20% or more and 75% or less. is there. The details of the transmittance measurement are as described in the section of Examples, but using a flat plate having a thickness of 2 mm obtained by injection molding the polyester resin composition at a mold temperature of 60 ° C., using a spectrophotometer. To be measured. The average value is a value obtained by dividing the sum of the transmittances at each wavelength at 800 to 1100 nm by the number of measurements. The number of measurements depends on the sampling pitch. For example, when the sampling pitch is 1 nm, transmittance data for each 1 nm such as 800, 801, 802, ..., 1098, 1099, 1100 nm is obtained, and the number of measurements is 301. Therefore, in this case, the average value of the transmittances at wavelengths of 800 to 1100 nm is calculated by (sum of transmittances at each wavelength / 301).
Since the average value of the transmittance at wavelengths of 800 to 1100 nm is in this range, it is difficult for the sunlight to reach a high temperature even if it is condensed.
A feature of the polyester composition of the present invention is that the infrared light transmittance is dramatically improved while maintaining high crystallinity. Therefore, even if sunlight is collected, it is unlikely that the temperature will be extremely high and scratches will not easily occur. If the average value of the transmittance at a wavelength of 800 to 1100 nm exceeds 75%, the crystallinity of the resin composition is significantly lowered and the heat resistance is impaired, which is not preferable. If the average value of the transmittance at wavelengths of 800 to 1100 nm is less than 20%, the temperature may become extremely high due to the concentration of sunlight. The average value of the transmittance at wavelengths of 800 to 1100 nm is preferably 25% or more and 70% or less.

Since the polyester resin composition of the present invention has the above-mentioned constitution, the heat deformation temperature under a load of 0.45 MPa is 150 ° C or higher. The heat distortion temperature is measured as described in the Examples section.
When the heat distortion temperature is lower than 150 ° C, the heat resistance is insufficient, and it may not be used in applications where heat resistance is required. It can be said that when the heat distortion temperature is 150 ° C. or higher, the polyester resin composition satisfies the heat resistance as the resin for the lamp member. The heat distortion temperature is preferably 155 ° C. or higher, in which case the heat resistance as the resin for the lamp member is more highly satisfied, and 160 ° C. or higher is more preferable, and in that case, it can be said that it is further highly satisfied.
Generally, a technique of adding an inorganic filler such as talc is known as a technique for increasing the heat distortion temperature, but according to the present invention, high heat resistance (heat distortion temperature) can be obtained without adding the inorganic filler. To be It is considered that this is achieved because the effect of the organic carboxylic acid alkali metal salt (B) enables formation of fine crystals of uniform size while maintaining or increasing the crystallinity of the resin composition.

In the polyester resin composition of the present invention, the haze value of the glass plate after the fogging test (160 ° C) can be 5% or less. According to the present invention, generation of gas can be effectively suppressed, and excellent fogging resistance can be obtained.
If a large amount of gas is generated and the haze value of the glass plate after the fogging test (160 ° C.) exceeds 5%, there is a problem of fogging in practical use as various lamp parts. Furthermore, the mold is likely to be contaminated during injection molding, which may adversely affect the quality and productivity.

The fogging test can be performed by the following method.
A small piece of about 40 mm x 40 mm is cut out from an injection molded product (thickness 2 mm), and a total of 10 g of the small piece is put into a glass tube (for example, φ65 x 80 mm) whose bottom is covered with aluminum foil and placed on a hot plate. set. Further, after covering with a slide glass (for example, 78 mm × 76 mm × thickness 1 mm) so that there is no gap in the glass tube, heat treatment is performed at 160 ° C. for 24 hours (as a result of this heat treatment, the inner wall of the slide glass is covered with polyester). Deposits due to decomposition products sublimated from the resin composition are deposited). The haze value of the slide glass is measured using a haze meter or the like.

[Colorant (D)]
The polyester resin composition of the present invention may contain a colorant (D).
When a pigment is used as the colorant, the infrared transmissivity is remarkably reduced, so that it is preferable to use an infrared transmissive dye. Known infrared ray transmissive dyes can be used, and one kind or a mixture of two or more kinds of dyes may be used. The dye may be added directly to the resin during compounding, or may be added as a masterbatch. From the viewpoint of dispersibility and handleability, it is more preferable to add them in a masterbatch. The color is preferably black from the viewpoint of designability.
Examples of the dye that can be added to the polyester resin composition include dyes such as quinoline compounds, anthraquinone compounds, and perinone compounds. These have good heat resistance and are unlikely to be thermally decomposed during compounding or injection molding of a polyester resin composition.
From the viewpoint of heat resistance and fogging property, the molecular weight per molecule of the infrared light transmissive dye is preferably 350 or more, more preferably 380, even more preferably 400 or more. The melting point is preferably 150 ° C or higher, more preferably 180 ° C or higher, even more preferably 200 ° C or higher. Either the molecular weight or the melting point may satisfy this range, and it is particularly preferable that both the molecular weight and the melting point satisfy this range. When two or more types of infrared ray transmissive dyes are mixed and used, it is preferable that the molecular weight and melting point of each dye alone satisfy the above ranges.
However, even if the molecular weight and melting point satisfy the above range, the interaction with the gas component contained in the resin is high, etc., so that the gasification component may be induced when it volatilizes and the dye may volatilize together. . In the present invention, anthraquinone compounds and perinone compounds can be preferably used from the viewpoint of fogging property.
When the colorant (D) is contained, its content is preferably 0.05 to 3 parts by mass with respect to 100 parts by mass of the polyester resin (A). If it is less than 0.05 part by mass, the hiding property is low and the designability may be impaired. If it exceeds 3 parts by mass, bleed-out or fogging may become a problem. The content of the colorant (D) is more preferably 0.1 to 2 parts by mass, still more preferably 0.2 to 1 part by mass.
When the colorant is commercially available as a masterbatch, the content as a colorant (especially in the case of a dye) is usually about 5 to 20% by mass, although it depends on the type of base resin or colorant used. Often

When the infrared light transmissive dye is added as a masterbatch, the hue of the masterbatch pellets (measured value in pellet form) is L ^* a ^* b ^* hue L ^* value (Color- L) is 22 or less, the hue a ^* value (Color-a) is −1.5 or more and 1.5 or less, and the hue b ^* value (Color-b) is −1.5 or more and 1.5 or less. (All values measured by SCE method).
When the hue of the masterbatch of the infrared transmissive dye is within the above range, the polyester resin composition of the present invention can obtain sufficient blackness without impairing the dispersibility and handleability of the dye.
If the hue of the masterbatch exceeds the above range, the polyester resin composition may not obtain sufficient blackness, and the designability may be impaired.
The hue of the masterbatch pellets is more preferably a hue L ^* value (Color-L) of 21 or less and a hue a ^* value (Color-a) of -1 or more according to the L ^* a ^* b ^* system of the CIE color difference system. 1 or less, the hue b ^* value (Color-b) is -1 or more and 1 or less (all are measured by the SCE method).

In the polyester resin composition of the present invention containing the colorant (D), it is preferable that a flat plate having a thickness of 2 mm obtained from the polyester resin composition has a transmittance of substantially 0% at a wavelength of 300 to 700 nm. . The transmittance measurement at this wavelength is the same as above.
“Substantially” means that noise during measurement is not considered. Generally, when 0 ± 0.05%, it can be regarded as substantially 0%. In the present invention, the transmittance within the range of 0 ± 0.05% at wavelengths of 300 to 700 nm is substantially 0%.
When the transmittance at a wavelength of 300 to 700 nm is substantially 0%, the visible light hiding property is high and the design property is high, which is preferable. When the transmittance at a wavelength of 300 to 700 nm exceeds 0% (substantially 0%), the visible light hiding property is insufficient, and the designability is low.

From the viewpoint of designability, the polyester resin composition of the present invention containing the colorant (D) has a hue L ^* value (Color-L) of 7 or less in the CIE color difference system L ^* a ^* b ^* system (SCE method). (Measured value according to 1.) is preferable.
Color-L ≦ 7 (I)
When the L ^* value is 7 or less, the polyester resin composition of the present invention can have sufficient blackness, and a molded product obtained by melt molding or the like can also exhibit sufficient blackness. Therefore, the design is excellent. The hue L ^* value is preferably 6 or less, more preferably 5 or less. When the hue L ^* value is higher than 7, the blackness is insufficient and the designability is low.

In order to further improve heat resistance and rigidity, the polyester resin composition of the present invention may contain an inorganic filler (E) as long as the characteristics of the present invention are not impaired. The inorganic filler (E) is not particularly limited, and known ones can be used. The inorganic filler (E) may be surface-treated in order to improve compatibility and dispersibility with the polyester resin composition.
From the viewpoint of surface appearance, the average particle diameter of the inorganic filler (E) is preferably 3.0 μm or less. The content of the inorganic filler (E) is preferably 1 part by mass or less, more preferably 0.8 part by mass or less, still more preferably 0.5 part by mass or less, relative to 100 parts by mass of the polyester resin (A). . If it exceeds 1 part by mass, coarse crystals may be formed using the inorganic filler as a crystal nucleating agent, and the infrared transmittance may be significantly reduced.
As described above, a technique of adding an inorganic filler such as talc is generally known as a technique of increasing the heat distortion temperature. However, the infrared light transmissivity may be significantly reduced due to the size of the crystal generated from the inorganic filler as crystal nuclei, and the temperature tends to rise due to the concentration of sunlight. Therefore, in one preferable embodiment of the polyester resin composition of the present invention, an inorganic filler such as talc is not contained.

The polyester resin composition of the present invention may contain a release agent in order not to impair the characteristics of the present invention, in order to further improve the releasability.
The content of the release agent is preferably 0.1 to 3 parts by mass with respect to 100 parts by mass of the polyester resin (A). When the amount of the release agent is less than 0.1 parts by mass, a sufficient release effect cannot be obtained, and defective release or release wrinkles may become a problem. The mold release agent itself becomes a gas or bleeds out to contaminate the mold, or adheres to the lens cover or mirror under the temperature environment of 100 ° C to 200 ° C to cause fogging. There is a problem of causing (fogging). When the release agent exceeds 3 parts by mass, these problems become remarkable.

  The type of release agent is not particularly limited as long as it can be used for polyester. For example, long-chain fatty acids or their esters, metal salts, amide compounds, polyethylene wax, silicon, polyethylene oxide and the like can be mentioned. The long-chain fatty acid preferably has 12 or more carbon atoms, and examples thereof include stearic acid, 12-hydroxystearic acid, behenic acid, and montanic acid. Partial or total carboxylic acid is esterified with monoglycol or polyglycol. Or may form a metal salt. Examples of the amide compound include ethylene bis terephthalamide and methylene bis stearyl amide. These release agents may be used alone or as a mixture. As the release agent, there is a compound which overlaps with the above-mentioned component (B). When such a compound is used as the release agent, the total amount of the component (B) and the release agent is as described above (B). ) It must be within the range of the allowable content of the component.

In addition, the polyester resin composition of the present invention may contain various additives within the known range, if necessary, as long as the characteristics of the present invention are not impaired. Known additives include, for example, heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, plasticizers, modifiers, antistatic agents, flame retardants and the like.
The polyester resin composition of the present invention preferably accounts for 85% by mass or more in total of the components (A), (B), (C), and (D) (the component (D) is an optional component), 90 It is more preferable to occupy mass% or more, and it is further preferable to occupy 95 mass% or more.

  As the method for producing the polyester resin composition of the present invention, the above-mentioned components and, if necessary, various stabilizers and the like are mixed and melt-kneaded. As the melt-kneading method, any method known to those skilled in the art can be used, and a single-screw extruder, a twin-screw extruder, a pressure kneader, a Banbury mixer or the like can be used. Above all, it is preferable to use a twin-screw extruder. As a general melt-kneading condition, in the twin-screw extruder, the cylinder temperature is 230 to 270 ° C. and the kneading time is 2 to 15 minutes.

  The method for molding the polyester resin composition of the present invention is not particularly limited, and known methods such as injection molding, extrusion molding and blow molding can be used. Among them, the injection molding method is preferably used from the viewpoint of versatility.

  In the molded product of the polyester resin composition of the present invention, the light-reflecting metal layer can be directly formed (vapor deposited) on at least a part of the surface. The vapor deposition method is not particularly limited, and a known method can be used.

  A molded product molded using the polyester resin composition of the present invention can be suitably used as a design member (particularly a lamp member). For example, it can be used as a member for automobile lamps (headlamps, etc.), light reflectors (extensions, reflectors, housings, etc.), and also for lighting fixtures, electric / electronic parts, household sundries, etc.

  Hereinafter, the present invention will be described in more detail with reference to Examples, but 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) Transmittance of infrared light (wavelength 800 to 1100 nm) / visible light (wavelength 300 to 700 nm) The pellets obtained in Examples and Comparative Examples were molded using an injection molding machine. Using a injection molding machine EC-100N (manufactured by Toshiba Machine Co., Ltd.), a flat plate molded product having a thickness of 100 mm × 100 mm × 2 mm was injection molded. Molding was performed at a cylinder temperature of 260 ° C and a mold temperature of 60 ° C.
Using a spectrophotometer UV-3150 (manufactured by Shimadzu Corporation) (a barium sulfate-based white plate is used as the standard white plate), a sampling pitch of 1.0 nm and a slit width (12) of a transmittance of 300 to 1500 nm are used. The measurement was performed, and the average value of the transmittances at wavelengths of 800 to 1100 nm (sum of transmittances at each wavelength / 301) was calculated.
When a colorant was used, the transmittance at a wavelength of 300 to 700 nm was measured separately.

(2) Heat distortion temperature (load: 0.45 MPa)
A multipurpose test piece of ISO-3167 was molded using an injection molding machine EC-100N, and the heat distortion temperature was measured according to ISO-75 under a load of 0.45 MPa.

(3) Haze value A small piece with a size of about 40 mm x 40 mm is cut out from an injection-molded product having a thickness of 2 mm, and 10 g of the piece is put into a glass tube (φ65 x 80 mm) having a bottom covered with an aluminum foil and hot. It was set on a plate (Neo Hot Plate HT-1000, manufactured by As One Co.). Furthermore, after covering the glass tube with a slide glass (78 mm × 76 mm × thickness 1 mm), heat treatment was performed at 160 ° C. for 24 hours. As a result of this heat treatment, deposits such as decomposition products sublimated from the resin composition were deposited on the inner wall of the slide glass. The haze value of these slide glasses was measured using a haze meter NDH2000 (manufactured by Nippon Denshoku Industries Co., Ltd.).

(4) MFR (melt flow rate)
It was measured by method A according to ISO-1133. The temperature and load conditions were measured at 250 ° C. and 2160 g.

(5) Flexural strength, flexural modulus, flexural modulus It was measured according to ISO-178.

(6) Hue L ^* Value The hue of the flat plate of the polyester resin composition was measured by the following method.
An injection molding machine EC-100N (manufactured by Toshiba Machine Co., Ltd.) was used to injection-mold a flat plate molded product having a thickness of 100 mm × 100 mm × 2 mm using a die having a mirror surface # 6000 polished on one surface. Molding was performed at a cylinder temperature of 260 ° C and a mold temperature of 60 ° C.
Using a precision spectrophotometric colorimeter TC-1500SX (manufactured by Tokyo Denshoku Co., Ltd.), the hue L ^* value (CIE color difference system) on the mirror surface side of the molded plate is measured according to JIS Z 8722 and JIS Z 8781-4. did. D65 light source, 10 ° visual field, 0 ° -d method, SCE method were used for measurement.
The hue of the infrared transparent dye masterbatch pellet was measured by the following method.
Using a precision spectrophotometric colorimeter TC-1500SX (manufactured by Tokyo Denshoku Co., Ltd.), according to JIS Z 8722, JIS Z 8781-4, put the pellets in the attached case and set them on the turntable to set the hue L ^*. The a ^* b ^* value (CIE color difference system) was measured. D65 light source, 10 ° visual field, 0 ° -d method, SCE method were used for measurement.

  The compounding components used in Examples and Comparative Examples are shown below.

Polyester resin (A);
Polybutylene terephthalate resin (a): IV = 0.83 dl / g, acid value = 30 eq / t
Polyethylene terephthalate resin (b): IV = 0.62 dl / g, acid value = 30 eq / t
Polytrimethylene terephthalate resin (c): IV = 0.93 dl / g, Cortera (manufactured by Shell Co.)
Amorphous resin;
Polycarbonate resin: Caliber 301-40 (manufactured by Sumika Styron Polycarbonate)

Aliphatic carboxylic acid alkali metal salt (B);
(B-1) Sodium caprylate (manufactured by Nitto Kasei Co., Ltd., melting point 220 ° C.)
(B-2) Sodium stearate (NOF Corporation, melting point 230 ° C.)
Other nuclear agents:
(B-3) ADEKA STAB NA-11 (not aromatic carboxylic acid alkali metal salt, aromatic nucleating agent, manufactured by ADEKA, melting point ≧ 400 ° C.)
(B-4) ADEKA STAB NA-21 (not aromatic carboxylic acid alkali metal salt, aromatic nucleating agent, manufactured by ADEKA, melting point ≧ 210 ° C.)

Polyfunctional glycidyl group-containing styrene acrylic polymer (C);
(C-1) ARUFON UG-4050 (manufactured by Toagosei Co., Ltd., Mw: 8500, epoxy value 0.67 meq / g, refractive index 1.55)
(C-2) ARUFON UG-4070 (manufactured by Toagosei Co., Ltd., Mw: 9700, epoxy value 1.4 meq / g, refractive index 1.57)

Colorant (D);
(D-1) Infrared light transmissive dye masterbatch: PBF-TT2399B-PBT (PBT (polybutylene terephthalate) resin-based black dye masterbatch, toning product in which anthraquinone compound and perinone compound are mixed, containing dye Rate total 10% by mass; manufactured by Resino Color Industry Co., Ltd.), Pellet hue: Color-L = 19.5, Color-a = -0.2, Color-b = -0.9.
(D-2) Purple dye: DCC-V01301 (manufactured by Ningbo DCC Chemicals)

Inorganic filler;
Talc (average particle diameter: 2.5 μm [laser diffraction method]): Microace SG-95 (manufactured by Nippon Talc Co., Ltd.) As the average particle diameter, a catalog value was adopted.

Release agent;
Triglycerin fulbehenate: Poem TR-FB (manufactured by Riken Vitamin Co.)
Stabilizer;
Antioxidant: Irganox 1010 (manufactured by BASF)

(Examples 1 to 12, Comparative Examples 1 to 10)
The compounding ingredients compounded in the combinations shown in Tables 1 and 2 were obtained by compounding with a co-direction twin-screw extruder set to a cylinder temperature of 250 ° C. (260 ° C. for Example 8 and Comparative Examples 2, 3, 4). The cooled strands were water cooled and pelletized. Each of the obtained pellets was dried at 130 ° C. for 4 hours and used in each of the above evaluation tests. The results are shown in Tables 1 and 2.

As shown in Table 1, the molded articles obtained from the polyester resin compositions of the present invention in Examples 1 to 8 and 12 have an infrared light transmittance of 20% or more and a heat distortion temperature of 150 ° C or more, which are excellent. It can be seen that it has excellent characteristics. Further, in all cases, the haze value of the glass plate after the fogging test was as good as 5% or less.
It can be seen that in Examples 9 and 10, the addition of the black colorant can impart excellent visible light hiding properties. The physical properties were the same as before the addition of the colorant, and all were good. Further, the haze value of the glass plate after the fogging test was as good as 5% or less. In Example 11 using the purple dye, the infrared light transmittance and other physical properties were good, but the hue L ^* exceeded 7, and the blackness was insufficient.
In Comparative Example 1, since the organic carboxylic acid alkali metal salt and the inorganic filler were not added, the infrared light transmittance and haze were not a problem, but the heat distortion temperature was low. In Comparative Examples 2 and 3, the amorphous resin was added, and high infrared light transmittance was obtained, but the heat distortion temperature was lower than that of Comparative Example 1, and the haze of the glass plate after the fogging test was The value has increased. By adding the inorganic filler (Comparative Example 4), the heat distortion temperature slightly increased, but it was not sufficient.
When an inorganic filler is added to the composition of Comparative Example 1 (Comparative Examples 5 and 6), the heat distortion temperature is increased, but the infrared light transmittance is lowered, so that the physical properties of the heat distortion temperature and the infrared light transmittance are reduced. It was difficult to achieve both.
In Comparative Example 7 in which the amount of the alkali metal salt of an organic carboxylic acid added was small, the infrared light transmittance and the heat distortion temperature were low.
Comparative Example 8 not containing the styrenic polymer (C) containing a polyfunctional glycidyl group was confirmed to have lower infrared light transmittance, worse fogging, and a lower heat distortion temperature than Examples 2, 3, and 4. . It is also considered that the dispersion of the organic carboxylic acid alkali metal salt (B) is non-uniform, but there was also a problem that the measurement variation was very large regarding the heat distortion temperature.
In Comparative Examples 9 and 10 in which a crystal nucleating agent other than the alkali metal salt of an organic carboxylic acid was used, improvement in transparency and heat distortion temperature was not observed. It is presumed that the cause was that the microcrystallization effect was not sufficient and the crystal size became large.

  INDUSTRIAL APPLICABILITY The polyester resin composition of the present invention has excellent infrared light transmittance, and also has good heat resistance and low gas properties, so that it is used as a design member (especially for lamp members in which scratches due to sunlight concentration are a problem). It is a polyester resin composition suitable for use as a) and has a great industrial utility value.

Claims (6)

0.1 to 1 part by mass of an organic carboxylic acid alkali metal salt having 3 to 40 carbon atoms (B) and 100 parts by mass of a polyester resin (A), and a polyfunctional glycidyl group-containing styrene polymer (C) 0.05. Is a polyester resin composition containing 3 to 3 parts by mass, wherein the polyester resin (A) is a polybutylene terephthalate resin (a) and a polyethylene terephthalate resin (b) in a mass ratio of 100: 0 to 50:50. in comprises a polyester resin composition the polyester resin composition is characterized by satisfying the following requirements (1) and (2).
(1) The average value of the transmittance at a wavelength of 800 to 1100 nm of a flat plate having a thickness of 2 mm obtained from the polyester resin composition is 20% or more and 75% or less (2) The heat distortion temperature (0.45 MPa) is Must be 150 ° C or higher The metal constituting the organic carboxylic acid alkali metal salt (B) having 3 to 40 carbon atoms is one kind or two or more kinds selected from lithium, sodium, and potassium, and is described in claim 1 . Polyester resin composition. Organic carboxylic acid constituting the organic carboxylic acid alkali metal salt of the 3 to 40 carbon atoms (B) is, in any one of claims 1-2, characterized in that an aliphatic carboxylic acid having 3 to 20 carbon atoms The polyester resin composition described. It includes a colorant (D), any of claim 1 to 3 in which the transmittance at a wavelength of 300~700nm flat plate having a thickness of 2mm was obtained from the polyester resin composition is characterized by a substantially 0% The polyester resin composition according to the item 1. The polyester resin composition according to claim 4 , comprising a colorant (D), wherein the polyester resin composition satisfies the following requirement (3).
(3) Color-L ≦ 7
[In the above formula, Color-L represents the hue L ^* value of the CIE color difference system L ^* a ^* b ^* system of the polyester resin composition. ] Are parts lamp molding using a polyester resin composition according to any one of claims 1-5.