WO2016133056A1

WO2016133056A1 - Infrared light-permeable polyester resin composition

Info

Publication number: WO2016133056A1
Application number: PCT/JP2016/054328
Authority: WO
Inventors: 卓也下拂; 知英中川; 安井　淳一
Original assignee: 東洋紡株式会社
Priority date: 2015-02-16
Filing date: 2016-02-15
Publication date: 2016-08-25
Also published as: JPWO2016133056A1

Abstract

The invention is a polyester resin composition that satisfies requirements (1) and (2) below and contains 0.1-1 part by mass of a C3-40 organoarboxylic acid alkali metal salt (B) and 0.05-3 parts by mass of a polycarbodiimide compound (C) per 100 parts by mass of a polyester resin (A), wherein the polyester resin composition has excellent infrared light permeability as well as good heat resistance and low gassing, and is suitable for use as a design member (in particular, a lamp member). (1) The average value of the transmittance at a wavelength of 800-1100 nm of a 2 mm thick plate obtained from this polyester resin composition is 20 to 75%. (2) The heat deformation temperature (0.45 MPa) is 150°C or higher.

Description

Infrared light transmitting polyester resin composition

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

Polybutylene terephthalate resin is widely used as an injection-molded product in the fields of automobile parts, mechanical parts, electrical / communication parts, etc. by utilizing its excellent injection moldability, mechanical properties, heat resistance, electrical properties, chemical resistance, etc. It's being used. Furthermore, it is excellent in mold transferability, and can be suitably used for lamp members for automotive extension applications that require particularly good appearance. In addition, it is necessary to highly control the heat resistance of the resin and the suppression of gas generation (low gasity) during molding.

On the other hand, in recent years, LED lights are mounted on headlamps of luxury cars and the like, and lamp designs have begun to be renewed. For example, in the reflector type (light reflected from the light source is reflected by the reflector), it is necessary to deposit aluminum on the part immediately adjacent to the light source, but this is the projector type (light source light is condensed and irradiated on the front lens). There are also designs that have been changed to have a black original specification for the part closest to the light source. However, due to this change, when the sunlight is reflected by the projector lens and the light is collected on the surrounding black part, the sunlight collection is such that the condensing part becomes very hot and scratches are caused. The light problem started to occur (although this phenomenon has been known for a long time, it has never been a problem in lamp design). In response to this problem, there is a demand for a material that transmits infrared light that does not become high temperature even when sunlight is condensed, and a material that has heat resistance and does not get scratched even at high temperatures.

As a technique for transmitting infrared light, for example, Patent Documents 1 to 3 disclose polybutylene terephthalate or a resin comprising polybutylene terephthalate and a polybutylene terephthalate copolymer, polycarbonate resin, styrene acrylonitrile resin, 1,4-cyclohexanediene. A resin composition comprising an amorphous resin such as a polyester resin containing a methanol component is disclosed. However, these technologies are useful for increasing the infrared light transmittance of polybutylene terephthalate resin, but the thermal deformation temperature is remarkably lowered by the addition of amorphous resin. It is difficult to use.

Moreover, as a technique for obtaining a black original polyester resin composition that suppresses temperature rise caused by solar sunshine, for example, Patent Document 4 discloses a polyethylene terephthalate resin composition containing a pigment that does not contain carbon black but is blackened by color matching. It is disclosed. According to the present invention, the use of a non-carbon black pigment can reduce the temperature corresponding to the amount of heat stored due to the infrared light absorption of carbon black, but its temperature rise inhibiting effect is small and greatly improved. There is room.

On the other hand, a technique for adding an alkali metal salt of an aliphatic carboxylic acid to polyester in order to enhance infrared light transmittance is disclosed (for example, see Patent Document 5). Although it is possible to increase the infrared light transmittance by this technology, according to the composition of this technology, bleedout caused by alkali metal salt of aliphatic carboxylic acid or its decomposition product and mold contamination during injection molding Is very likely to be a problem.

JP 2004-315805 A Japanese Patent No. 5034217 JP 2008-106217 A JP 2014-125588 A Special table 2014-512420 gazette

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

That is, the present invention has the following configuration.
[1] 0.1 to 1 part by mass of an organic carboxylic acid alkali metal salt (B) having 3 to 40 carbon atoms and 0.05 to 3 polycarbodiimide compound (C) with respect to 100 parts by mass of the polyester resin (A) A polyester resin composition containing a mass part, 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 2 mm-thick flat plate obtained from the polyester resin composition is 20% or more and 75% or less (2) The thermal deformation temperature (0.45 MPa) [2] The polyester resin (A) contains the polybutylene terephthalate resin (a) and the polyethylene terephthalate resin (b) in a mass ratio of 100: 0 to 50:50 [ 1] The polyester resin composition described in 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] Or the polyester resin composition as described in [2].
[4] The organic carboxylic acid constituting the alkali metal salt of organic carboxylic acid having 3 to 40 carbon atoms (B) is an aliphatic carboxylic acid having 3 to 20 carbon atoms, [1] to [3 ] The polyester resin composition in any one of.
[5] The transmittance at a wavelength of 300 to 700 nm of a 2 mm-thick flat plate obtained from the polyester resin composition containing the colorant (D) is substantially 0% [1] to [4] The polyester resin composition according to any one of [4].
[6] The polyester resin composition according to [5], including 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 by the LIE ^* L ^* a ^* b ^* system of the CIE color difference system of the polyester resin composition. ]
[7] A lamp part 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 increased 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. Furthermore, since a resin molded body in which gas generation is also highly controlled can be obtained, it is excellent in fogging resistance and it is possible to reduce mold contamination during injection molding.

Hereinafter, the present invention will be described in detail.

[Polyester resin (A)]
The polyester resin (A) that can be used in the present invention is preferably a polyester resin having a dicarboxylic acid component and a diol component as constituent units.
As the dicarboxylic acid component, those having 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, and particularly preferably 95 mol% or more with respect to all dicarboxylic acid units. In addition to aromatic dicarboxylic acids, aliphatic dicarboxylic acids can be used.

Aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2, Fragrances 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, anthracene dicarboxylic acid 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. Examples include chain or alicyclic dicarboxylic acids.
The above dicarboxylic acid components can be used alone or in admixture 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 still more preferably 10 mol% or less, based on all 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, and 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, Examples include 1,10-decanediol, 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,2-cyclohexanedimethanol and the like. Of these, ethylene glycol, 1,3-propanediol, and 1,4-butanediol are preferable.

Preferable polyester resins (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 an o-chlorophenol solution is measured at 25 ° C., and is 0.52 to 1.25 dl. / G is more suitable, more preferred is 0.58 to 1.12 dl / g, and most preferred is 0.62 to 1.02 dl / g. It 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 are improved.
In this invention, it is preferable to contain polybutylene terephthalate resin (a) and polyethylene terephthalate resin (b) with a specific compounding quantity.
Moreover, in this invention, it is also preferable to use polytrimethylene terephthalate resin (c) and polybutylene naphthalate resin (d) as a polyester resin (A). In that case, the polytrimethylene terephthalate resin (c) can be used as an alternative to the polyethylene terephthalate resin (b), and the polybutylene naphthalate resin (d) can be used as an alternative to the polybutylene terephthalate resin (a). is there.

The polybutylene terephthalate resin (a) that can be used in the present invention is a polycondensation reaction mainly comprising terephthalic acid or an ester-forming derivative thereof and 1,4-butanediol or an ester-forming derivative thereof. It is a polymer obtained by a general polymerization method. The polymer is preferably a polymer having a butylene terephthalate repeating unit of 80 mol% or more, more preferably 90 mol% or more, still more preferably 95 mol% or more, and most preferably 100 mol%. Other copolymer components may be included in a range not impairing the characteristics, for example, about 20% by mass or less. Examples of copolymers include polybutylene (terephthalate / isophthalate), polybutylene (terephthalate / adipate), polybutylene (terephthalate / sebacate), polybutylene (terephthalate / decanedicarboxylate), polybutylene (terephthalate / naphthalate), poly (butylene) / Ethylene) terephthalate, etc., may be used alone or in combination of two or more.

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. More preferably in the range of 0.52 to 1.25 dl / g, more preferably in the range of 0.58 to 1.12 dl / g, and 0.62 to 1.02 dl / g. Those in the g range are most preferred. 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 are improved.

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

The polyethylene terephthalate resin (b) that can be used in the present invention is a conventional polymerization method such as a polycondensation reaction mainly comprising terephthalic acid or an ester-forming derivative thereof and ethylene glycol or an ester-forming derivative thereof. The resulting polymer. The polymer is preferably a polymer having an ethylene terephthalate repeating unit of 80 mol% or more, more preferably 90 mol% or more, still more preferably 95 mol% or more, and most preferably 100 mol%. Other copolymer components may be included in a range not impairing 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, and the like, and may be used alone or in combination of two or more. By using the 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. More preferably in the range of 0.45 to 1.35 dl / g, more preferably in the range of 0.50 to 1.20 dl / g, and 0.55 to 1.05 dl / g. Those in the range are most preferable. When the intrinsic viscosity of (b) is 0.36 to 1.60 dl / g, the mechanical properties and moldability of the polyester resin composition of the present invention are improved.

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 blending amount of the polybutylene terephthalate resin (a) and the polyethylene terephthalate resin (b) is 100: 0 to 50:50 in terms of mass ratio ((a) :( b)) of (a) and (b). It is preferable that More preferably (a) :( b) = 100: 0 to 60:40, still more preferably (a) :( b) = 100: 0 to 70:30, particularly preferably (a) :( b) = 100 : 0 to 80:20, most preferably (a) :( b) = 100: 0 to 90:10. Although it is possible to control the molding shrinkage of the resin composition by blending the polyethylene terephthalate resin (b), if the blending amount exceeds 50 parts by mass, the mold releasability during injection molding of the resin composition may deteriorate. Since the heat resistance of the resin is reduced and the crystallization speed of the polyester resin composition is slow, crystallization gradually proceeds in a temperature environment of 100 ° C. to 200 ° C. and gradually transmits infrared light. May decrease.
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 description of the above blending amounts, “polybutylene terephthalate resin (a)” means “at least one of polybutylene terephthalate resin (a) and polybutylene naphthalate resin (d)”, “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 metal 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 decrease. Moreover, when the organic carboxylic acid alkali metal salt (B) is blended in an amount exceeding 1 part by mass, the polyester resin composition is significantly decomposed by the catalytic action of the alkali metal salt, 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). It is more preferable.

The organic carboxylic acid alkali metal salt (B) having 3 to 40 carbon atoms 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 an unsaturated group, an alicyclic group, an aromatic group or a hydroxyl group, a phosphate ester group is part of the bond. 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, mytilic acid, palmitic acid, margaric acid, stearic acid, oleic acid, linoleic acid, Montanic acid and the like are preferable, and among alkali metal salts, sodium salt is preferable in terms of solubility in polyester resin and good crystal nucleation.

The organic carboxylic acid constituting 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 from the viewpoint of melting property and compatibility with the polyester resin. An aliphatic carboxylic acid having 6 to 20 carbon atoms is more preferable. 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.

The details of the effect of improving the infrared light transmittance by the organic carboxylic acid alkali metal salt (B) are not clear, but the differential scanning calorific value of the composition of the polyester resin (A) and the organic carboxylic acid alkali metal salt (B). As a result of analysis (DSC), compared with the polyester resin (A) alone, the crystallization peak at the time of temperature shift shifted to a high temperature side and became sharper, and further, organic carboxylic acid was detected in the composition. It is estimated as follows.
The behavior of the DSC means that the crystallization speed is increased and the crystal size is made uniform. Therefore, it is considered that the alkali metal carboxylic acid metal salt (B) acts on the polyester resin (A) as a crystal nucleating agent to form microcrystals with a uniform size, thereby increasing the infrared light transmittance. Further, the alkali metal salt of organic carboxylic acid (B) changes the carboxyl group of the polyester resin (A) to an alkali metal base by an ion exchange reaction, lowers the mobility of the molecular chain terminal, 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 the infrared light transmittance with a small amount of blending compared to the alkali metal salt other than the organic carboxylic acid. This is because the organic carboxylic acid alkali metal salt (B) has a relatively small molecular weight, so when the same part by mass is added, the number of molecules increases and crystallization tends to occur, and the molecular size is relatively small. Therefore, this is considered to be due to the fact that the crystal size of the polyester resin (A) generated using this as a crystal nucleus is small (that is, the crystal is difficult to grow and microcrystallizes).

Two or more of the above organic carboxylic acid alkali metal salts (B) may be used in combination. Use of a compound having 3 to 14 carbon atoms and a compound having 14 or more carbon atoms is preferred in that the solubility of those having 3 to 14 carbon atoms is improved and the infrared light transmittance is easily improved.

[Polycarbodiimide compound (C)]
The polyester resin composition of the present invention contains 0.05 to 3 parts by mass of the polycarbodiimide compound (C) with respect to 100 parts by mass of the polyester resin (A).
By making the polycarbodiimide compound (C) within this range, it is possible to efficiently exhibit the thickening effect and the trapping effect of the gasifying component such as the organic carboxylic acid to be liberated. At the time of kneading, the melt viscosity is increased due to the thickening effect and the shear stress is increased, whereby the dispersion of the alkali metal salt of the organic carboxylic acid (B) can be promoted. Further, the growth of crystals is suppressed by the thickening effect, and it is possible to promote the microcrystallization with the organic metal carboxylate (B). Furthermore, excellent low gas properties can be realized by the trapping effect of gasifying components such as free organic carboxylic acids and free hydroxyl group-containing compounds.
If the polycarbodiimide compound (C) is more than 3 parts by mass, gelation may be caused by reaction with the polyester resin (A), or infrared light transmittance may be reduced due to compatibility problems. Further, when the polycarbodiimide compound (C) is less than 0.05 parts by mass, the dispersion of the organic carboxylic acid alkali metal salt (B) becomes non-uniform, and the scavenging effect of the free acid or the free hydroxyl group-containing compound is reduced. Low gas properties may be impaired. The blending amount of the polycarbodiimide compound (C) is preferably 0.07 parts by mass, more preferably 0.08 parts by mass with respect to 100 parts by mass of the polyester resin (A). It is more preferably 1 part by mass, particularly preferably 0.15 part by mass, and the upper limit is preferably 2 parts by mass, more preferably 1 part by mass, and 0.5 parts by mass. More preferably.

The polycarbodiimide compound (C) can have a carboxylic acid reactive group and a hydroxyl group reactive group in one molecule.
Such a compound having a carboxylic acid reactive group and a hydroxyl group reactive group in one molecule is a free acid or a free hydroxyl group-containing compound produced by decomposition of an organic carboxylic acid alkali metal salt (B) or a fatty acid ester compound, and a subsequent heat treatment. It can capture the free acid and free hydroxyl group-containing compound generated during the process and use at high temperature, and can effectively prevent volatilization.
Since free acids and free hydroxyl group-containing compounds greatly affect the generation of gas, their capture is effective in preventing volatilization. In particular, free carboxylic acid volatilizes at a relatively low temperature, and the volatiles crystallize, which often causes fogging. Therefore, capturing the free carboxylic acid is extremely important.

Examples of the functional group that reacts with the carboxylic acid include a glycidyl group, an oxazoline group, an oxetane group, and a carbodiimide group. However, general glycidyl group-containing compounds, oxazoline group-containing compounds, and oxetane group-containing compounds do not react quickly, and it may be difficult to coexist with a functional group that reacts with a hydroxyl group. Since it is intense, it is often difficult to use it in applications requiring fogging resistance. On the other hand, carbodiimide compounds have a faster reaction than glycidyl groups, oxazoline groups, and oxetane groups, and are very preferably used for capturing free carboxylic acids.
The functional group that reacts with a hydroxyl group is different from the functional group that reacts with a carboxylic acid, and examples thereof include an isocyanate group and an acid anhydride group, and an isocyanate group is particularly preferred from the viewpoint of reactivity. As a result of extensive studies, the compound having a carboxylic acid group-reactive group and a hydroxyl group-reactive group in one molecule is most preferably a compound having a carbodiimide group and an isocyanate group in one molecule.

The merit of containing a carboxylic acid group-reactive group and a hydroxyl group-reactive group in one molecule is that these functional groups can easily react with either a thermoplastic resin or a free acid or a free hydroxyl group-containing compound, and have a large molecular weight. It is that the volatilization of the fatty acid ester decomposition product can be significantly reduced by connecting the plastic resin and the decomposition product with a reactive compound. Therefore, in the case of the thermoplastic polyester resin containing a carboxylic acid as in the present invention, effects such as hydrolysis inhibition can be imparted, and effects such as improved processability as a resin composition can be exhibited.

Polycarbodiimide is a compound having two or more —N═C═N— structures in one molecule, and a known one prepared by decarbonation of a diisocyanate compound can be used (US Pat. No. 2,941,956, (See Japanese Patent Publication No. 47-3279, J. Org. Chem., 28, 2069-2075 (1963), Chemical Review 1981, Vol. 81, No. 4, 619-621).

Examples of the diisocyanate compound include aliphatic or alicyclic isocyanate compounds such as hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, cyclohexane-1,4-diisocyanate, isophorone diisocyanate, and methylcyclohexane diisocyanate, 4,4-diphenylmethane diisocyanate, 4,4- Diphenyldimethylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,5-naphthylene diisocyanate, xylylene diisocyanate, tetramethylxylylene Range isocyanate, 1,3,5-triisopropylphenylene-2,4-diisocyanate, etc. Family isocyanate compounds may be mentioned, it can be used by copolymerizing them singly or in combination.

Further, the polycarbodiimide compound (C) may have a branched structure, and a functional group other than a carbodiimide group or an isocyanate group may be introduced by copolymerization. Further, a part or all of the terminal isocyanate may be blocked. As end-capping agents, monoisocyanate compounds such as phenyl isocyanate, tris isocyanate, dimethylphenyl isocyanate, cyclohexyl isocyanate, butyl isocyanate, naphthyl isocyanate, -OH group, -COOH group, -SH group, -NH-R (R is hydrogen) A compound having an atom or an alkyl group) or the like can be used.
The merit of blocking part or all of the terminal isocyanate is that the reaction in the compound can be easily controlled, and the degree of polymerization and melt viscosity can be controlled. When a certain amount or more of a polycarbodiimide compound in which the terminal isocyanate is not blocked is added to the polyester resin (A), the melt viscosity may be remarkably increased due to thickening, and the addition amount may be limited. Thus, if the amount of polycarbodiimide compound added is limited, the expected effect may not be obtained. When such a problem arises, it can be solved by using a polycarbodiimide compound in which a terminal isocyanate is blocked.
Even if all of the terminal isocyanates are blocked, the effect of capturing the free carboxylic acid due to the high reactivity of the carbodiimide group is high, so that a sufficiently high low gas property can be obtained.

Commercially available products include Starbucks series from Rhein Chemie, Carbodilite series from Nisshinbo, Cosmonate LK from Co., Ltd., Cosmonate LL, Rupranate MM-103 from BASF INOAC Polyurethane, etc. It is done. Especially, it is preferable to use the polycarbodiimide compound which consists of an aliphatic or alicyclic structure from a compatible viewpoint with a fatty acid. If it is an aromatic polycarbodiimide, the compatibility with the fatty acid may be poor, and the carbodiimide group and the fatty acid cannot react efficiently, reducing the effect. In the above-mentioned commercial products, the Nisshinbo Carbodilite series has an aliphatic or alicyclic structure and is preferably used.

Since the polyester resin composition of the present invention has the above-described configuration, the average transmittance of a 2 mm thick flat plate obtained from the polyester resin composition at a wavelength of 800 to 1100 nm is 20% or more and 75% or less. is there. Details of the transmittance measurement are as described in the Examples section, but using a 2 mm thick flat plate obtained by injection molding the polyester resin composition at a mold temperature of 60 ° C., a spectrophotometer was used. Measured. The average value is a value obtained by dividing the sum of transmittance at each wavelength by the number of measurements in the range of 800 to 1100 nm. The number of measurements depends on the sampling pitch. For example, when the sampling pitch is 1 nm, transmittance data is obtained every 1 nm, such as 800, 801, 802,..., 1098, 1099, 1100 nm, and the number of measurements is 301. Therefore, in this case, the average value of the transmittance at a wavelength of 800 to 1100 nm is obtained by (the sum of the transmittance at each wavelength / 301).
When the average value of the transmittance at a wavelength of 800 to 1100 nm is in this range, even if sunlight is collected, it is difficult to reach a high temperature.
A feature of the polyester composition of the present invention is that the infrared light transmittance is remarkably improved while maintaining high crystallinity. For this reason, even if sunlight is condensed, it is difficult for the temperature to become very high and scratches are hardly formed. If the average transmittance of wavelengths from 800 to 1100 nm exceeds 75%, the crystallinity of the resin composition is remarkably lowered and the heat resistance is impaired. If the average value of the transmittance at a wavelength of 800 to 1100 nm is less than 20%, the temperature may become very high due to sunlight collection. The average value of transmittance at a wavelength of 800 to 1100 nm is preferably 25% or more, and more preferably 70% or less.

Since the polyester resin composition of the present invention has the above-described configuration, the thermal deformation temperature at 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 less than 150 ° C., the heat resistance is insufficient, and in particular, it may not be used for applications requiring heat resistance. When the heat distortion temperature is 150 ° C. or higher, it can be said that the polyester resin composition satisfies the heat resistance as a lamp member resin. The heat distortion temperature is preferably 155 ° C. or higher. In that case, the heat resistance as a lamp member resin is more highly satisfied, and 160 ° C. or higher is more preferable.
In general, a technique for adding an inorganic filler such as talc is known as a technique for increasing the heat distortion temperature. However, according to the present invention, high heat resistance (heat distortion temperature) can be obtained without adding an inorganic filler. It is done. This is considered to be realized by the effect of the alkali metal salt of organic carboxylic acid (B) because it is possible to form microcrystals 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, gas generation can be effectively suppressed and excellent fogging resistance can be achieved.
When the amount of gas generated is large and the haze value of the glass plate after the fogging test (160 ° C.) exceeds 5%, there is a practical problem of fogging as various lamp parts. In addition, the mold is likely to be contaminated during injection molding, which may adversely affect quality and productivity.

The fogging test can be performed by the following method.
Cut out a small piece of about 40 mm x 40 mm from an injection molded product (thickness 2 mm), put a total of 10 g in a glass tube (for example, φ65 x 80 mm) with an aluminum foil covered, and place it on a hot plate. set. Further, the glass tube is covered with a slide glass (for example, 78 mm × 76 mm × thickness 1 mm) so that there is no gap between the glass tube, and then heat treated at 160 ° C. for 24 hours. 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 can contain a colorant (D).
When a pigment is used as the colorant, the infrared transmittance is remarkably lowered. Therefore, it is preferable to use an infrared light transmitting dye. As the infrared light transmitting dye, known 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 at the time of compounding, or may be added as a master batch. From the viewpoint of dispersibility and handling properties, it is preferable to add them in a master batch. The color is preferably black from the viewpoint of design.
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 hardly thermally decomposed during compounding or injection molding of the polyester resin composition.
From the viewpoint of heat resistance and fogging properties, the molecular weight per molecule of the infrared light transmitting dye is preferably 350 or more, more preferably 380 or more, and further preferably 400 or more. The melting point is preferably 150 ° C. or higher, more preferably 180 ° C. or higher, and further preferably 200 ° C. or higher. It is sufficient that either the molecular weight or the melting point satisfy this range, and it is particularly preferable that both the molecular weight and the melting point satisfy this range. When two or more infrared light transmissive dyes are used in combination, the molecular weight and melting point of each dye alone preferably satisfy the above ranges.
However, even if the molecular weight and the melting point satisfy the above ranges, there are cases in which the dye is also volatilized due to the vaporization of the gasification component due to the high interaction with the gasification component contained in the resin. is there. In the present invention, anthraquinone compounds and perinone compounds can be preferably used from the viewpoint of fogging properties.
When the colorant (D) is contained, the content thereof 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 concealability is low and the designability may be impaired. If it exceeds 3 parts by mass, bleeding out and fogging may become a problem. The content of the colorant (D) is more preferably 0.1 to 2 parts by mass, and further preferably 0.2 to 1 part by mass.
When the colorant is commercially available as a masterbatch, the content as a colorant is usually about 5 to 20% by mass (especially in the case of dyes), although it depends on the type of base resin and colorant used. Often.

When the infrared light transmitting dye is added as a master batch, the hue of the master batch pellet (measured value in the form of pellet) is the hue L ^* value (Color-) according to the L ^* a ^* b ^* system of the CIE color difference system. L) is preferably 22 or less, hue a ^* value (Color-a) is from −1.5 to 1.5, and hue b ^* value (Color-b) is preferably from −1.5 to 1.5. (All measured values by SCE method).
When the hue of the master batch of the infrared light transmitting dye is within the above range, the polyester resin composition of the present invention can obtain sufficient blackness without impairing the dispersibility and handling 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.
Color of the masterbatch pellets is more preferably, a hue ^{L *} value according to ^{^the L} * ^a * ^{b *} system of CIE color difference system (Color-L) is 21 or less, hue ^{a *} value (Color-a) is -1 1 or less, hue b ^* value (Color-b) is −1 or more and 1 or less (both measured values by SCE method).

In the polyester resin composition of the present invention containing the colorant (D), the transmittance at a wavelength of 300 to 700 nm of a 2 mm-thick flat plate obtained from the polyester resin composition is preferably substantially 0%. . The transmittance measurement at this wavelength is the same as described above.
“Substantially” means that noise during measurement is not taken into consideration. Usually, when it is 0 ± 0.05%, it can be regarded as substantially 0%. In the present invention, the fact that the transmittance at a wavelength of 300 to 700 nm is in the range of 0 ± 0.05% is substantially 0%.
It is preferable that the transmittance at a wavelength of 300 to 700 nm is substantially 0% because the visible light hiding property is high and the design property is high. When the transmittance at a wavelength of 300 to 700 nm exceeds 0% (substantially 0%), the visible light concealing property is not sufficient, and the design property is low.

From the viewpoint of design, the polyester resin composition of the present invention containing a colorant (D) has a hue L ^* value (Color-L) of CIE color difference L ^* a ^* b ^* of 7 or less (SCE method) Measured value).
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 can exhibit sufficient blackness even in a molded product obtained by melt molding or the like. Therefore, it is excellent in design property. 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 design property 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. An inorganic filler (E) is not specifically limited, A well-known thing can be used. In addition, the inorganic filler (E) may be subjected to a surface treatment in order to improve compatibility and dispersibility with the polyester resin composition.
In view of surface appearance, the average particle size of the inorganic filler (E) is preferably 3.0 μm or less. Moreover, 1 mass part or less is preferable with respect to 100 mass parts of polyester resins (A), and, as for content of an inorganic filler (E), 0.8 mass part or less is more preferable, and 0.5 mass part or less is further more preferable. . When the amount exceeds 1 part by mass, coarse crystals may be generated 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 for increasing the heat distortion temperature. However, due to the size of the crystals that produce the inorganic filler as crystal nuclei, the infrared light transmittance may be significantly reduced, and the temperature is likely to rise due to sunlight collection. Therefore, as one preferable aspect of the polyester resin composition of the present invention, it does not contain an inorganic filler such as talc.

In order to further improve the releasability, the polyester resin composition of the present invention may contain a release agent as long as the characteristics of the present invention are not impaired.
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). If the release agent is less than 0.1 parts by mass, a sufficient release effect cannot be obtained, and there may be problems such as defective release and release wrinkles. The mold release agent itself becomes a gas and bleeds out to contaminate the mold, and adheres to the lens cover, mirror, etc. in a temperature environment in the range of 100 ° C to 200 ° C. There is a problem of generating (fogging). When the release agent exceeds 3 parts by mass, these problems become significant.

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 esters thereof, 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 a metal salt may be formed. Examples of the amide compound include ethylene bisterephthalamide and methylene bisstearyl amide. These release agents may be used alone or as a mixture. As the release agent, there is a compound overlapping with the above component (B). When such a compound is used as the release agent, the total amount of the component (B) and the amount of the release agent is as described above (B ) It must be within the range of acceptable contents of components.

In addition, the polyester resin composition of the present invention can contain various additives in a known range as long as the characteristics of the present invention are not impaired, if necessary. Examples of known additives include 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 occupies 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 95% by mass or more, and it is even more preferable to occupy 95% by mass or more.

As a method for producing the polyester resin composition of the present invention, it can be produced by mixing the above-described components and various stabilizers as necessary, and melt-kneading. Any method known to those skilled in the art can be used as the melt-kneading method, and a single screw extruder, a twin screw extruder, a pressure kneader, a Banbury mixer, or the like can be used. Among these, it is preferable to use a twin screw extruder. As general melt kneading conditions, in a 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 these, an injection molding method is preferably used from the viewpoint of versatility.

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

The 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 (head lamps, etc.), light reflectors (extensions, reflectors, housings, etc.), lighting equipment, electrical / electronic parts, household goods, etc.

Hereinafter, the present invention will be described more specifically 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 an 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 a standard white plate), a transmittance of a wavelength of 300 to 1500 nm is obtained with a sampling pitch of 1.0 nm and a slit width (12). Measurements were made to calculate the average transmittance (sum of transmittance at each wavelength / 301) at wavelengths of 800 to 1100 nm.
When the colorant was used, the transmittance at a wavelength of 300 to 700 nm was separately measured.

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

(3) Haze value A small piece having a size of about 40 mm × 40 mm was cut out from an injection molded product having a thickness of 2 mm, and a total of 10 g was put into a glass tube (φ65 × 80 mm) whose aluminum foil was covered to make a bottom, and hot It was set on a plate (Neo Hot Plate HT-1000, manufactured by AS ONE). Furthermore, after the glass tube was covered 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 due to decomposition products sublimated from the resin composition were deposited on the inner wall of the slide glass. The haze values of these slide glasses were measured using a haze meter NDH2000 (manufactured by Nippon Denshoku Industries Co., Ltd.).

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

(5) Flexural strength, deflection rate, flexural modulus 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.
Using an 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 using a mold having a mirror surface polished on # 6000 file on one side. 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. Measurements were taken with a D65 light source, 10 ° field of view, 0 ° -d method, and SCE method.
The hue of the infrared light transmissive dye masterbatch pellet was measured by the following method.
Using a precision spectrophotometric colorimeter TC-1500SX (manufactured by Tokyo Denshoku Co., Ltd.), in accordance with JIS Z 8722 and JIS Z 8781-4, put the pellet in the attached case, set it on the turntable, and hue L ^* The a ^* b ^* value (CIE color difference system) was measured. Measurements were taken with a D65 light source, 10 ° field of view, 0 ° -d method, and SCE method.

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)
Amorphous resin;
Polycarbonate resin: Caliber 301-40 (manufactured by Sumika Stylon Polycarbonate)

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

Polycarbodiimide compound (C);
(C-1) Carbodilite HMV-15CA (manufactured by Nisshinbo Chemical Co., Ltd., polycarbodiimide with all terminal isocyanates blocked)
(C-2) Carbodilite LA-1 (manufactured by Nisshinbo Chemical Co., Ltd., polycarbodiimide having an isocyanate at the end)

Colorant (D);
(D-1) Infrared light transmissive dye masterbatch: PBF-TT2399B-PBT (PBT (polybutylene terephthalate) resin-based black dye masterbatch, toning product mixed with anthraquinone compound and perinone compound, containing dye 10% by mass in total; 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 fillers;
Talc (average particle size: 2.5 μm [laser diffraction method]): Microace SG-95 (manufactured by Nippon Talc Co., Ltd.) Catalog values are used for the average particle size.

Release agent;
Triglycerin flubehenate: Poem TR-FB (manufactured by Riken Vitamin)
Stabilizers;
Antioxidant: Irganox 1010 (BASF)

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

As shown in Table 1, molded articles obtained from the polyester resin compositions of Examples 1 to 8 and 12 of the present invention have an infrared light transmittance of 20% or more and a heat distortion temperature of 150 ° C. or more, which is excellent. It can be seen that it has the characteristics. In all cases, the haze value of the glass plate after the fogging test was as good as 5% or less.
It turns out that Example 9, 10 has provided the visible light hiding property which was excellent by addition of a black coloring agent. The physical properties were the same as before the colorant addition, and all were good. Furthermore, the haze value of the glass plate after the fogging test was also good at 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 there was no addition of an organic metal carboxylic acid alkali metal salt or an inorganic filler, there was no problem in infrared light transmission and haze, but the heat distortion temperature was low. Comparative Examples 2 and 3 were at a level to which an 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 obtained. The value became high. By adding the inorganic filler (Comparative Example 4), although the heat distortion temperature slightly increased, it was not sufficient.
When an inorganic filler is added to the composition of Comparative Example 1 (Comparative Examples 5 and 6), although the heat distortion temperature is increased, the infrared light transmittance is decreased. Therefore, the heat distortion temperature and the infrared light transmissive physical properties are reduced. It was difficult to achieve both.
In Comparative Example 7 in which the amount of the organic carboxylic acid alkali metal salt was small, the infrared light transmittance and the heat distortion temperature were low.
In Comparative Example 8 not containing the polycarbodiimide compound (C), compared to Examples 2, 3 and 4, the infrared light transmittance was lowered and fogging was confirmed, and the heat distortion temperature was also low. Moreover, although it seems that dispersion | distribution of organic carboxylic-acid alkali metal salt (B) is non-uniform | heterogenous, there also existed a problem that the measurement variation was very large regarding heat deformation temperature.
In Comparative Examples 9 and 10 using a crystal nucleating agent other than the organic metal carboxylic acid alkali metal salt, improvement in transparency and heat distortion temperature was not observed. It is presumed that the microcrystallization effect was not sufficient and the crystal size was increased.

Since the polyester resin composition of the present invention is excellent in infrared light transmission and has good heat resistance and low gas properties, it is a design member (particularly for lamp members in which scratches due to sunlight collection are a problem) ) Is a polyester resin composition suitable for use as an industrial utility value.

Claims

0.1 to 1 part by mass of an organic carboxylic acid alkali metal salt (B) having 3 to 40 carbon atoms and 0.05 to 3 parts by mass of a polycarbodiimide compound (C) with respect to 100 parts by mass of the polyester resin (A) A polyester resin composition comprising the polyester resin composition, 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 2 mm-thick flat plate obtained from the polyester resin composition is 20% or more and 75% or less (2) The thermal deformation temperature (0.45 MPa) 150 ° C or higher
The polyester resin composition according to claim 1, wherein the polyester resin (A) contains a polybutylene terephthalate resin (a) and a polyethylene terephthalate resin (b) in a mass ratio of 100: 0 to 50:50. .
3. The metal constituting the alkali metal salt of organic carboxylic acid having 3 to 40 carbon atoms (B) is one or more selected from lithium, sodium, and potassium. The polyester resin composition as described.
4. The organic carboxylic acid constituting 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. The polyester resin composition as described.
The transmittance at a wavelength of 300 to 700 nm of a 2 mm-thick flat plate obtained from the polyester resin composition containing the colorant (D) is substantially 0%. A polyester resin composition according to claim 1.
The polyester resin composition according to claim 5, wherein the polyester resin composition contains a colorant (D) and satisfies the following requirement (3).
(3) Color-L ≦ 7
[In the above formula, Color-L represents the hue L * value by the LIE * L * a * b * system of the CIE color difference system of the polyester resin composition. ]
A lamp part molded using the polyester resin composition according to any one of claims 1 to 6.