JP5729169B2 - Thermoplastic polyester resin composition and light reflector using the same - Google Patents

Description

  The present invention relates to a thermoplastic polyester resin composition used for a light reflector part having a light reflecting layer on the surface thereof, such as a lamp for an automobile, and a light reflector formed by molding the same.

  Light reflectors such as extensions and reflectors used in automobile lamps, lighting fixtures, etc. have high luminance appearance (smoothness), uniform reflectivity, heat resistance against heat generated by light from the light source, etc. Is required. Conventionally, such products have been provided with a metal thin film on the surface of a bulk molding compound (hereinafter abbreviated as BMC) which is a thermosetting resin.

  Although BMC is excellent in heat resistance, dimensional stability, etc., the molding cycle is long, and it takes time to process burrs during molding. There was a problem. As a means for improving such problems, a method using a thermoplastic resin has been implemented.

  As an example of using a thermoplastic resin, a composition in which various reinforcing materials are blended with a crystalline resin typified by a polyester resin such as polybutylene terephthalate or polyethylene terephthalate, or an amorphous resin typified by a polycarbonate resin. Has been proposed. In particular, in light reflectors that require mechanical properties, electrical properties, heat resistance, good moldability, etc., various reinforcing materials are used, especially for polybutylene terephthalate resin alone or a mixture of polybutylene terephthalate resin and other resins. The polyester resin composition which mix | blended is widely employ | adopted.

  As a technique for forming a metal thin film or the like to give a performance as a light reflector to a molded article made of the thermoplastic resin composition described above, pretreatment by undercoat treatment before forming a light reflective metal layer on the molded article And a direct method of directly forming a metal layer.

  Of course, when the undercoat treatment is performed, the process, cost, and the like increase, so it goes without saying that the direct method that does not require the undercoat treatment is useful. However, for that purpose, the resin molded product itself needs to have good surface smoothness and high glossiness and brightness. In addition, it is necessary to highly control the heat resistance of the resin and the suppression of gas generation (low gasity) at the time of molding from the application. As a resin composition that can be vapor-deposited by the direct method, for example, there is a resin composition proposed in Patent Document 1, but since a very high level is required on all of the material surface, the mold surface, and the molding surface, The defect rate during mass production tends to be relatively high. In addition, since filler embossing occurs at the time of molding, it is necessary to use a reinforcing material with very fine particle size and to reduce the amount of addition, so it is not expected to improve rigidity and heat resistance, especially There is a high possibility that the resin properties are insufficient for the recent reduction in thickness and weight. For this reason, there are many complicated shapes, and large-sized molded products have not yet been widely adopted, and a method of performing an undercoat treatment is common.

However, there is a problem in the method of performing the undercoat treatment. Many automotive lamp parts have complicated shapes, so there is a high possibility that mold release defects will occur during molding. Therefore, a release agent is always blended in the resin. Naturally, the release property is improved by adding a release agent, but the release agent itself becomes a gas or bleeds out so that the mold becomes dirty or becomes cloudy when used as a light reflector. May occur or the adhesion to the metal layer may be insufficient.
This is particularly noticeable in the direct method. When the undercoat treatment is carried out, the degree of haze when the light reflector is used is somewhat suppressed by the influence of the undercoat layer, but if there is a lot of release agent when applying the undercoat, A phenomenon in which the coating component does not work well (hereinafter referred to as a repellency phenomenon) occurs, resulting in poor deposition appearance. Therefore, various release agents have been proposed as means for improving these (for example, Patent Documents 2 and 3).

JP 2009-102581 A JP 2008-280498 A JP 2005-97563 A

However, since the above-mentioned document 2 uses a high molecular weight olefin-based release agent, the release property may be insufficient due to the effect that bleeding out to the surface is considerably suppressed.
In the above-mentioned document 3, reference is made to releasability and heat clouding, but not to the repelling phenomenon. Thus, there has never been a clear description of the repellency phenomenon, and a resin composition that controls the repellency phenomenon particularly during the undercoat treatment and has good releasability is desired. ing. Therefore, an object of the present invention is to have good mold releasability and heat resistance while reducing mold contamination when molding a light reflector part made of resin by injection molding or the like, and the surface of the molded product It is possible to obtain a resin molded body with a highly controlled bleed-out to the surface, so it is possible to suppress the repelling phenomenon during undercoating and maintain a high brightness feeling even when exposed to a high temperature atmosphere Another object of the present invention is to provide a resin composition that maintains good shape retention even in a molded product having a small thickness.

  As a result of intensive studies, the present inventors have found that the purpose can be achieved if a specific release agent is used as a component that achieves both the repelling phenomenon and the releasability, and the degree of release agent precipitation is within a specific range. The present invention was completed by maintaining heat resistance by adding a specific amount of a heading and a specific filler.

That is, the thermoplastic resin composition of the present invention comprises (A) polybutylene terephthalate resin and (B) polyethylene terephthalate resin so that the mass ratio of (A) / (B) is 70/30 to 85/15. 70 to 95 parts by mass of the obtained resin component, 5 to 30 parts by mass of (C) inorganic filler, and 0.1 to (D) the release agent with respect to 100 parts by mass in total of (A) to (C). A thermoplastic polyester resin composition characterized by satisfying the following conditions (1) and (2) in a resin composition containing 1 part by mass, wherein the molded product is obtained by injection molding the composition.
(1) When the thermoplastic polyester resin composition was injection-molded into a flat plate shape having a cylinder temperature of 260 ° C. and a mold temperature of 100 ° C. and a thickness of 2 mmt, and the infrared spectrum of this flat plate surface was measured, 2920 cm ⁻¹ and 2964 cm ⁻ The relative intensity value of absorption appearing in ¹ is I ₂₉₂₀ / I _2964, and the value obtained by subtracting the relative intensity value of the resin composition obtained by removing only the (D) release agent component from the thermoplastic polyester resin composition is obtained from this value. When it is set as A value, this A value is in the range of 0.10 to 0.16. (2) The thermal deformation temperature at 0.45 MPa load of the resin composition based on ISO-75 is 170 ° C. or higher. is there

  According to the resin composition of the present invention, the mold has good mold releasability and heat resistance while reducing mold contamination when molding a light reflector part made of resin by injection molding or the like, and molding. Since it is possible to obtain a resin molded product with a highly controlled bleed-out to the surface of the product, it is possible to suppress the repelling phenomenon during the undercoat treatment, and even when exposed to a high temperature atmosphere, it has a high brightness feeling. It can be held, and the shape can be held well even in a molded product with a small thickness.

Hereinafter, the present invention will be described in detail.
In the thermoplastic polyester resin composition of the present invention, (A) polybutylene terephthalate resin and (B) polyethylene terephthalate resin are blended so that the mass ratio of (A) / (B) is 70/30 to 85/15. 70 to 95 parts by mass of resin component, 5 to 30 parts by mass of (C) inorganic filler, and 0.1 to 1 (D) release agent with respect to 100 parts by mass in total of (A) to (C). It is a thermoplastic polyester resin composition containing parts by weight.

In order to achieve both releasability and suppression of the repelling phenomenon during undercoat treatment, the present inventors only need to use a specific component for the release agent and have a release agent precipitation degree within a specific range. I found out. In order to obtain such a thermoplastic resin composition, the type and blending amount of the (D) release agent to be described later may be adjusted. Moreover, what is necessary is just to adjust the kind (particle size) and compounding quantity of (C) component for heat resistance maintenance.
Here, each component in the thermoplastic polyester resin composition of the present invention will be described.

  (A) The polybutylene terephthalate is not particularly limited, and is a homopolymer mainly composed of terephthalic acid and 1,4-butanediol. In addition, other components can be copolymerized up to about 5 mol% within a range that does not impair the moldability, crystallinity, surface gloss and the like.

  (A) The molecular weight of polybutylene terephthalate is reduced viscosity (0.1 g of sample is dissolved in 25 ml of a mixed solvent of phenol / tetrachloroethane (weight ratio 6/4) and measured at 30 ° C. using an Ubbelohde viscosity tube; dl / g) is preferably in the range of 0.6 to 1.2 dl / g, more preferably in the range of 0.6 to 1.0 dl / g. When the reduced viscosity is less than 0.6, it is not preferable because the toughness of the resin is lowered, and when it exceeds 1.0, the fluidity is greatly reduced.

  (B) The polyethylene terephthalate is not particularly limited, and may be a homopolymer of ethylene terephthalate units or a copolymer containing 70% by mass or more of ethylene terephthalate units in the repeating unit. Examples of the copolymerized monomer include aromatic or aliphatic polybasic acids such as isophthalic acid, naphthalenedicarboxylic acid, adipic acid, sebacic acid, trimellitic acid or esters thereof as dibasic acid components other than terephthalic acid. It is done. Examples of glycol components other than ethylene glycol include diethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol, 1,4-butanediol, 1,2-propanediol, 1,3-propanediol, and 2-methyl-1. , 3-propanediol and the like.

  (B) The molecular weight of polyethylene terephthalate is reduced viscosity (0.1 g of sample dissolved in 25 ml of a mixed solvent of phenol / tetrachloroethane (weight ratio 6/4) and measured at 30 ° C. using an Ubbelohde viscosity tube; dl / G) is preferably 0.4 to 0.8 dL / g. If the reduced viscosity is less than 0.4, the strength of the resin is lowered, which is not preferable.

  In particular, from the viewpoints of moldability and appearance, (A) polybutylene terephthalate and (B) polyethylene terephthalate are preferably used in combination, and the mixing ratio of (A) / (B) is 70/30 to 85. / 15 (mass ratio) is preferable. If the ratio of (A) is less than 70%, the crystallization characteristics of the resin composition deteriorate, so that there is a concern that defects such as defective mold release and a longer molding cycle occur. On the other hand, when the ratio of (A) is more than 85%, the resin composition is crystallized too quickly, and there is a concern that appearance defects such as embossing of the filler may occur. (A) / (B) is more preferably 73/27 to 83/17 (mass ratio).

(C) Inorganic filler in the present invention reduces mold shrinkage and improves heat resistance from the point that mold releasability and dimensional stability are required for the increase in size and shape of molded products. Used for purposes. (C) Quartz, talc, mica, clay, hydrotalcite, unfired clay, glass beads, graphite, calcium sulfate, barium carbonate, barium sulfate, magnesium carbonate, magnesium sulfate, calcium silicate, silicic acid as inorganic filler Examples include aluminum, titanium oxide, zinc oxide, magnesium oxide, silicon oxide, potassium titanate, magnesium titanate, barium titanate, bentonite, celite, wollastonite, and milled fiber which is a short glass fiber. It is not limited. These inorganic fillers may be used singly or in combination of two or more, as long as the properties are not deteriorated from the viewpoint of appearance of molded parts in automobile lamp parts. Among these, it is preferable to use plate crystals such as talc and mica, barium sulfate, and the like. Further, when the effect of improving heat resistance is taken into consideration, it is particularly preferable to use talc.
In order to exhibit the characteristics of the inorganic filler as described above, the content of (C) inorganic filler is (A) when the total of (A), (B), and (C) is 100 parts by mass. And (C) 5 to 30 parts by mass with respect to 70 to 95 parts by mass of the resin component consisting of (B). Preferably, it is 10-25 mass parts of (C) with respect to 75-90 mass parts of resin components which consist of (A) and (B).

(C) Although the particle diameter of the inorganic filler is not particularly limited, it is preferable to use an inorganic filler having an average particle diameter in the range of 3 to 10 μm in consideration of the characteristics of automobile lamp parts. When a material smaller than 3 μm is used, the appearance of the molded product is improved, but the reinforcing effect by the filler is reduced, so that rigidity and heat resistance are lowered, which is not preferable. On the other hand, when the particle diameter is larger than 10 μm, the filler is prominently raised on the surface of the molded product, and even if an undercoat treatment is performed when forming a light reflector, the surface smoothness may be inferior, which is not preferable.
(C) The inorganic filler is preferably talc having an average particle size of 3 to 10 μm. The average particle diameter of talc is more preferably 3 to 8 μm, and further preferably 4 to 7 μm.

(C) The inorganic filler may be surface-treated in order to improve compatibility and dispersibility. Even if it is not surface-treated, the amount added according to the present invention is not particularly problematic when it is formed and formed into a light reflector. However, when the surface treatment is performed, it is preferable that the surface treatment component is not gas. Examples of the surface treatment include treatment with a surface treatment agent, fatty acid treatment, SiO ₂ -Al ₂ O ₃ treatment, and the like. Examples of the surface treating agent include an aminosilane coupling agent, an epoxysilane coupling agent, a titanate coupling agent, and an aluminate coupling agent.

  (D) Release agent of this invention expresses the effect | action as a release agent as the name suggests. By forming an outer slipping film on the surface of the molded product during molding, good releasability is exhibited, and undercoat treatment is suppressed when undercoating is performed to form a light reflector. When the light reflector is held in a high temperature environment, the deposited layer is hardly fogged. (D) As a mold release agent, in order to solve the subject of the present invention, a polyglycerol type mold release agent is preferred.

The polyglycerin constituting the component (D) includes diglycerin, triglycerin, tetraglycerin, and the like, but polyglycerin higher than tetraglycerin does not exhibit sufficient releasability because the molecular weight increases. Among diglycerin and triglycerin, triglycerin is superior in volatility and bleed-out resistance.
In the present invention, the mold release agent (D) is a polyglycerin fatty acid ester in which fatty acids are bonded to all hydroxyl groups, and the polyglycerin component constituting is triglycerin or polyglycerin accounts for 80% by mass or more of triglycerin. Glycerin is preferred.

  Although the fatty acid which comprises (D) component is not restrict | limited in particular, using higher fatty acids, such as C22 (behenic acid)-C28 (montanic acid), releasability at the time of shaping | molding and suppression of the repelling phenomenon at the time of an undercoat process, In view of gas suppression, behenic acid is particularly preferable.

  (D) Content of a component is 0.1-1 mass part when the sum total of (A)-(C) component is 100 mass parts. When the content of the component (D) is less than 0.1 parts by mass, the mold release performance is deteriorated. When the content is more than 1 part by mass, the component (D) itself becomes a gas to deteriorate the appearance of the molded product, or the undercoat This is not preferable because the repelling phenomenon during processing increases. In order to achieve a good balance between releasability and suppression of the repelling phenomenon during undercoat treatment, the amount of component (D) added is particularly preferably 0.2 to 0.6 parts by mass.

The amount of precipitation of the component (D) on the surface of the molded product, that is, the region capable of achieving both the releasability and the suppression effect on the repelling phenomenon during the undercoat treatment can be quantified by infrared spectrum measurement. Since component (D) is a fatty acid ester, absorption of a methylene group is observed. Therefore, using a 2 mmt flat plate molded at a cylinder temperature of 260 ° C. and a mold temperature of 100 ° C., an absorption intensity (I ₂₉₂₀ ) of ₂₉₂₀ cm ⁻¹ attributed to the methylene group of component (D) from the infrared spectrum first. Further, the absorption intensity (I ₂₉₆₄ ) of ₂₉₆₄ cm ⁻¹ derived from the resin components (A) and (B) is read, the relative intensity (I ₂₉₂₀ / I ₂₉₆₄ ) _sample is calculated, and the release agent with respect to the resin component Calculate the percentage. Next, since 2920 cm ⁻¹ originally has absorption derived from the resin component, the resin component is subtracted, and (A = (I ₂₉₂₀ / I ₂₉₆₄ ) _sample − (I ₂₉₂₀ / I ₂₉₆₄ ) _reference ), derived from the mold release agent The amount of methylene group alone is estimated as the A value. At this time, (I ₂₉₂₀ / I ₂₉₆₄ ) _reference is calculated using a resin composition obtained by removing only the (D) release agent component from the thermoplastic polyester resin composition as a reference sample (reference). This comparison is from the viewpoint of the amount of methylene groups present on the surface. In some cases, the surface of a molded product molded under the above conditions may be used as a reference sample after washing with a solvent such as IPA to remove the component (D) on the surface layer.
The mold temperature is set to 100 ° C., which is higher than the actual molding of the lamp parts such as extensions (mold temperature 50 to 60 ° C.), so that more release agent components in the resin composition are deposited. This is to make it happen.

  The A value in the present invention is in the range of 0.10 to 0.16. When this A value was compared between the various (D) components and compared with the releasability at the time of molding and the occurrence frequency of the repelling phenomenon at the time of the undercoat treatment, it was confirmed that a correlation with the above phenomenon was obtained. In other words, when the A value is higher than 0.16, a relatively large amount of component (D) is deposited on the surface, so that the releasability is excellent but the repelling phenomenon occurs frequently. There is a tendency. On the other hand, when the A value is smaller than 0.10, the component (D) is relatively not deposited on the surface, so the repelling phenomenon is suppressed, but the releasability is low. It will decline.

  The present inventors pay attention to this A value, and find that it is very effective that the A value exists within a specific range in order to suppress the releasability and the repelling phenomenon during the undercoat treatment. In order to make the A value exist in a specific range, it has been found that it is effective to use a specific component. Since the above properties are compatible, it is of course possible to reduce mold contamination during molding, and when the light reflector is used, there is clouding of the vapor deposition surface when this molded product is held in a high temperature environment. It is possible to suppress gas generation.

  Car lamps that use extensions, etc., have a structure in which a light source device, reflector, extension, etc. are incorporated in a container sealed with a case (housing) that holds the lens and components. It will be exposed to high temperature environment. Especially in recent years, parts such as extensions are becoming thinner and thinner due to the trend toward higher design and lighter products. Therefore, in the case of thin molded products with low heat resistance of the resin, deformation occurs from its own weight or assembled parts when exposed to a high temperature environment, and the light distribution state changes, resulting in a commercial value May be reduced.

  At present, it is known that the temperature rise in the lamp component when the light source is turned on is about 170 to 180 ° C. For this reason, the resin composition is required to have approximately the same level of heat resistance. Therefore, it can be said that the heat distortion temperature at a load of 0.45 MPa is preferably 170 ° C. or higher as an index of heat resistance required for the resin composition.

In addition, the 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 colorants such as pigments, heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, plasticizers, modifiers, antistatic agents, flame retardants, and dyes.
The thermoplastic polyester resin composition of the present invention preferably occupies 85% by mass or more and 90% by mass or more in total of the components (A), (B), (C), and (D). More preferably, it occupies 95% by mass or more.

  As described above, the thermoplastic polyester resin composition of the present invention described above has excellent mold releasability and heat resistance while reducing mold contamination when molding a light reflector part made of resin by injection molding or the like. It is possible to obtain a resin molded body that has a highly controlled bleed-out to the surface of the molded product, so it is possible to reduce the repelling phenomenon during the undercoat treatment, and it is exposed to a high temperature atmosphere. In addition, it is possible to maintain a high luminance feeling, and the shape can be maintained well even in a molded product having a small thickness.

  As a method for producing the thermoplastic polyester resin composition of the present invention, it can be produced by mixing the above-described components and, if necessary, various stabilizers and pigments, and melt-kneading them. 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, and 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 220 to 270 ° C., and the kneading time is 2 to 15 minutes.

  The component for light reflectors of the present invention is formed using the thermoplastic polyester resin of the present invention. It does not restrict | limit especially as a shaping | molding method, Well-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. For the light reflector parts, vapor deposition specifications, unpainted specifications, etc. can be used according to the purpose and purpose. In addition, the smoothness and glossiness of the light reflector component surface are increased and the component having a better appearance can be obtained by setting the mold polishing count to 5000 or more.

  The light reflector of the present invention is obtained by forming a light reflective metal layer on the component for light reflector of the present invention after performing an undercoat treatment. It does not restrict | limit especially regarding undercoat and vapor deposition, A well-known method can be used.

  Examples of the light reflector thus obtained include light reflectors (extensions, reflectors, housings, etc.) of automobile lamps (headlamps, etc.).

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not restrict | limited at all by these Examples.
Each characteristic shown in the following examples and comparative examples was evaluated by the following test methods.

(1) Reduced viscosity of polyester (dl / g)
A 0.1 g sample was dissolved in 25 ml of a mixed solvent of phenol / tetrachloroethane (weight ratio 6/4) and measured at 30 ° C. using an Ubbelohde viscosity tube.
(2) A value Using a 2 mmt flat plate molded at a cylinder temperature of 260 ° C. and a mold temperature of 100 ° C., an absorption intensity of 2920 cm ⁻¹ attributed to the methylene group of component (D) from the infrared spectrum ( I ₂₉₂₀ ) and the absorption intensity (I ₂₉₆₄ ) of ₂₉₆₄ cm ⁻¹ derived from the resin components (A) and (B), and the relative intensity (I ₂₉₂₀ / I ₂₉₆₄ ) _sample is calculated. The ratio with respect to the resin component was calculated. Next, since 2920 cm ⁻¹ originally has absorption derived from the resin component, the resin component is subtracted, and (A = (I ₂₉₂₀ / I ₂₉₆₄ ) _sample − (I ₂₉₂₀ / I ₂₉₆₄ ) _reference ), derived from the mold release agent The amount of methylene group alone was estimated as the A value. At this time, as a reference sample (reference), a resin composition obtained by removing only the (D) release agent component from the thermoplastic polyester resin composition was prepared, and using this, (I ₂₉₂₀ / I ₂₉₆₄ ) _reference was calculated. . The infrared spectrum was measured at an incident angle of 45 ° by the ATR method using a Varian FT-IR apparatus FTS7000e.
(3) Bleed-out A 2 mmt flat plate (100 mm square) was produced by injection molding at a cylinder temperature of 260 ° C. and a mold temperature of 60 ° C., and this molded product was left in a 160 ° C. hot air dryer for 20 hours. The bleed out to the surface was visually observed and ranked in the following 4 levels.
A: Bleed out is not recognized at all.
○: Bleed-out is hardly recognized (a level that is slight but not a problem).
Δ: Some bleed out occurs.
X: Bleed-out is intense.
(4) Releasability When molding a flat plate shaped product with a step of 1 to 3 mm (50 mm × 100 mm) at a cylinder temperature of 260 ° C. and a mold temperature of 60 ° C., 3 seconds of injection, 5 seconds of cooling, cycle The mold release behavior at the time of continuous 50 shot molding under the condition of time 15 seconds was observed and ranked in the following three stages.
A: No problem (taken to the fixed side, deterioration of appearance due to defective mold release, etc.) is observed at 50 shots.
Δ: 50 shot continuous molding is possible, but appearance deterioration due to some mold release failure is observed.
X: The releasability is poor and continuous molding is impossible.
(5) Fogging property The molded product was cut into small pieces of about 10 mm × 10 mm, put in 10 g of a test tube (φ50 × mm), a glass plate was placed thereon, the lid was put on, and then set on a hot plate. In this state, heat treatment was carried out at 160 ° C. for 20 hours, and then the degree of cloudiness due to resin sublimate adhered to the inner wall of the glass plate was measured with a HAZE meter.
(6) Paint appearance (repellency characteristics)
A 100 × 100 × 2 mmt flat plate molded product molded at a cylinder temperature of 260 ° C. and a mold temperature of 100 ° C. is coated with a paint using a spray gun so that the thickness is uniformly about 10 μm. The state of the painted surface after drying for about 1 hour was observed and ranked in the following three levels. As a paint, Dainippon Paint Co., Ltd. Planit # 3000 was used.
○: The paint surface is hardly repelled and is in a good paint state.
Δ: Some repelling of the paint is observed on the painted surface. ×: Repelling is recognized on the painted surface in a considerable proportion.
(7) Heat resistance As a heat resistance index, a heat deformation temperature (a deflection temperature under load) at a low load (0.45 MPa) was measured by a test method based on ISO-75.

The raw materials used in the examples and comparative examples are as follows.
(A) Polybutylene terephthalate: manufactured by Toyobo Co., Ltd. Reduced viscosity 0.8 dl / g
(B) Polyethylene terephthalate: Toyobo Co., Ltd. reduced viscosity 0.7 dl / g
(C) Inorganic filler (C-1): Talc Hayashi Kasei Co., Ltd. “Talkan PK-P” average particle size 6.5 μm
(C-2): Talc “Microace SG-95” manufactured by Nippon Talc Co., Ltd., average particle diameter of 2.5 μm
(D) Mold release agent (D-1): Partially saponified ester of montanic acid “Licowax-OP” manufactured by Clariant Japan Co., Ltd.
(D-2): Triglycerin behenic acid full ester “Poem TR-FB” manufactured by Riken Vitamin Co., Ltd.
(D-3): Riken Vitamin Co., Ltd. Pentaerythritol stearate “Ricester EW-440A”
(D-4): Dipentaerythritol stearate ester “L-8483” manufactured by Riken Vitamin Co., Ltd.
(D-5): Nitto Kasei Kogyo Co., Ltd. calcium stearate “Ca-St P”
(D-6): Clariant Japan Co., Ltd. montanic acid calcium salt “CAV-102”

The thermoplastic polyester resin compositions of Examples and Comparative Examples were prepared by weighing the above raw materials according to the blending ratio (parts by mass) shown in Table 1, and using a 35φ twin screw extruder (manufactured by Toshiba Machine Co., Ltd.) with a cylinder temperature of 260 ° C., Melt kneading was performed at a screw speed of 120 rpm. All raw materials were charged from the hopper into the twin screw extruder. After the pellets of the obtained resin composition were dried, various samples for evaluation were molded with an injection molding machine. The molding conditions were a cylinder temperature of 260 ° C., a mold temperature of 60 ° C., or 100 ° C.
The evaluation results are shown in Table 1.

  In Examples 1-4, it turns out that the precipitation degree (A value) of a mold release agent component exists in an appropriate range, and the balance of various characteristics is taken well. On the other hand, in Comparative Examples 1 to 8, since the A value is out of the range, the coating appearance is particularly impaired, or the releasability is inferior. In Comparative Example 1, although the A value is within the range, the heat distortion temperature is low.

  By using the thermoplastic polyester resin composition of the present invention, good mold releasability and heat resistance can be achieved while reducing mold contamination when molding resin light reflector parts by injection molding or the like. It is possible to obtain a resin molded body that has a highly suppressed bleed-out to the surface of the molded product, so that it is possible to reduce the repelling phenomenon during the undercoat treatment and it is exposed to a high temperature atmosphere. In addition, it is possible to maintain a high luminance feeling, and the shape can be maintained well even in a molded product having a small thickness.

Claims (4)

70 to 95 parts by mass of a resin component prepared by blending (A) polybutylene terephthalate resin and (B) polyethylene terephthalate resin so that the mass ratio of (A) / (B) is 70/30 to 85/15, (C ) A resin composition containing 5 to 30 parts by mass of an inorganic filler and containing 0.1 to 1 part by mass of (D) a release agent with respect to a total of 100 parts by mass of (A) to (C), The mold release agent (D) is a polyglycerin fatty acid ester in which fatty acids are bonded to all hydroxyl groups, the polyglycerin component constituting is triglycerin, or polyglycerin in which triglycerin accounts for 80% by mass or more, and a fatty acid component is behenic acid, in a molded article obtained by injection molding the composition, the following conditions (1), a thermoplastic polyester resin composition characterized by satisfying the (2) .
(1) When the thermoplastic polyester resin composition was injection-molded into a flat plate shape having a cylinder temperature of 260 ° C. and a mold temperature of 100 ° C. and a thickness of 2 mmt, and the infrared spectrum of this flat plate surface was measured, 2920 cm ⁻¹ and 2964 cm ⁻ The relative intensity value of absorption appearing in ¹ is I ₂₉₂₀ / I _2964, and the value obtained by subtracting the relative intensity value of the resin composition obtained by removing only the (D) release agent component from the thermoplastic polyester resin composition is obtained from this value. When it is set as A value, this A value is in the range of 0.10 to 0.16. (2) The thermal deformation temperature at 0.45 MPa load of the resin composition based on ISO-75 is 170 ° C. or higher. is there The thermoplastic polyester resin composition according to claim 1, wherein the inorganic filler (C) is talc having an average particle diameter of 3 to 10 µm. Molded using a thermoplastic polyester resin composition according to claim 1 or 2 the light reflection body component. A light reflector in which a light-reflecting metal layer is formed on the surface of the component for light reflector according to claim 3 after an undercoat treatment.