JP4526756B2 - Thermoplastic resin composition, molded article and lighting fixture comprising the same - Google Patents

Description

【００８６】
【発明の効果】
本発明によれば、成形加工時にシルバーが発生せずに良好な表面外観が得られると共に、優れた耐候変色性及び光線反射性能を有するポリブチレンテレフタレート樹脂からなる熱可塑性樹脂組成物並びにそれからなる成形体等を得ることができる。さらに帯電防止剤を配合した場合には、優れた帯電防止性を併せて得ることができる。
【図面の簡単な説明】
【図１】本発明の評価試験に使用した薄型（ランプ横型）ダウンライト器具を例示する斜視図である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a thermoplastic resin composition comprising polybutylene terephthalate and a molded article comprising the same, and more specifically, a thermoplastic resin composition comprising polybutylene terephthalate having excellent light discoloration resistance and surface appearance and high light reflection performance. The present invention relates to a product and a molded body comprising the same.
[0002]
[Prior art]
Conventionally, as a light reflecting plate used for a lighting fixture, a glass or resin molded product obtained by depositing a metal plating or a metal thin film, or a coated product has been used. However, glass reflectors are disadvantageous in that they are heavy and easy to break, and reflectors made by depositing metal plating or metal thin films on resin molded products have a high cost for plating and vapor deposition, resulting in a high total cost. There was a point. Therefore, there has been a demand for a resin molded product having a high light reflectivity without the need for post-processing at a low price.
[0003]
In addition, reflectors with metal plating or metal thin film deposited have a very high ratio of regular reflectance to the entire light reflectance, and conversely low diffuse reflectance. Easy to generate. For example, when used in reflectors of luminaires such as downlights with open bottoms and base lights, or louvers, it may cause a very glaring sensation or an unpleasant sensation of darkness depending on the viewing angle. It was. Therefore, a white resin molded product having a high light reflectance and a very high ratio of the diffuse reflectance to the whole light reflectance has been demanded.
[0004]
In recent years, as a white resin reflector, a polyethylene terephthalate foam film (hereinafter abbreviated as “PET foam film”) or a polycarbonate resin composition is frequently used. The PET foamed film is obtained by foaming polyethylene terephthalate to which a white pigment is added to form microvoids, thereby providing a high light reflection function. A reflection plate made of a PET foam film has a high light reflection function and is in the form of a film, so that it does not have the freedom of shape as in injection molding, and it is difficult to combine a plurality of parts. Furthermore, since the mechanical strength is low, it has been difficult to apply to a member having a structural function. In order to increase the mechanical strength, it is necessary to use a plurality of pieces or to combine backup parts, and there is a problem that the cost is increased.
[0005]
On the other hand, the polycarbonate resin composition contains a polycarbonate resin, a white pigment (mainly titanium oxide) and a polycarbonate resin stabilizer, and the reflector made of the polycarbonate resin composition has a light reflection effect by the white pigment. Is to be used. Since the light-shielding property of this reflector can be adjusted by adjusting its thickness, it is possible to obtain a reflector having a higher luminance than when a reflector made of a PET foam film is used. Further, by increasing the content of titanium oxide in the polycarbonate resin composition, it is possible to improve the light shielding property and increase the light reflectance without increasing the thickness of the titanium oxide.
[0006]
However, in the conventional polycarbonate resin composition used as a material for the reflector, when the titanium oxide content is increased, the polycarbonate is heated and melted under the heat melting condition due to the chemically active sites present on the titanium oxide surface. As a result, the molecular weight of the material decreases and the mechanical properties deteriorate, and at the same time, coloring and silver are generated, so that a satisfactory reflector cannot be provided.
[0007]
In order to solve such problems, various polycarbonate resin stabilizers have been studied so far, and reflectors made of a polycarbonate resin composition containing them have been put into practical use. However, when such a resin stabilizer is blended, there is a problem in that the material cost increases and the light discoloration resistance decreases.
[0009]
In addition, since the PET foam film and the polycarbonate resin composition do not usually have antistatic properties, they are used, for example, as reflectors or louvers for lighting fixtures such as downlights with open bottoms and base lights. In this case, dust in the atmosphere adheres in a short time, causing not only a decrease in light reflectance, but also a cause of deteriorating appearance quality. Furthermore, since these are inferior in light discoloration resistance, they cannot be applied to a reflector of a luminaire used for a long time adjacent to a light source such as a fluorescent lamp.
[0010]
  Further, the use of a polybutylene terephthalate resin to which a treatment agent is added to titanium oxide other than that used in the present invention described below is also effective in improving the reflectance, but as in the present invention. The minimum value of total light reflectivity at a wavelength of 450 to 800 nm is 92% or more.RukoIt was not possible. In addition, by adding a fluorescent brightening agent, the minimum value of total light reflectance at a wavelength of 450 to 800 nm immediately after molding can be made 92% or more, but the light fast discoloration is remarkably inferior, and the luminaire It was not applicable to the reflector.
[0011]
[Problems to be solved by the invention]
An object of the present invention is to eliminate the above-mentioned problems, have a good surface appearance, and have a thermoplastic resin composition mainly composed of a polybutylene terephthalate resin having excellent light discoloration resistance and light reflection performance, and a molded body comprising the same. Is to provide.
[0012]
Another object of the present invention is to provide a thermoplastic resin composition mainly composed of a resin having an excellent antistatic property in addition to the surface appearance, light discoloration resistance and light reflection performance, and a molded article comprising the same. There is.
[0013]
[Means for Solving the Problems]
As a result of diligent research on the above problems, the inventors of the present invention compounded polybutylene terephthalate resin with a processed titanium oxide obtained by treating a rutile type titanium oxide having a very low content of a coloring metal material with a specific treatment agent. It has been found that the above-mentioned problems can be achieved by doing so.
[0014]
  That is, the present invention provides the following (1) to (9).
[0015]
  (1) Polybutylene terephthalate resin (A)For 100 parts by weightProcessed titanium oxide (B)5-10 parts by weight, 10 parts by weight or less of antistatic agent (C), and no fluorescent brightening agentA processing agent comprising a thermoplastic resin composition, wherein the processed titanium oxide (B) comprises alumina hydrate and silicic acid hydrate in rutile titanium oxide (a) having a coloring metal material content of 70 ppm or less. A thermoplastic resin composition obtained by adding (b) and having a content of the rutile-type titanium oxide (a) in the processed titanium oxide (B) of 96 to 99% by weight.
[0018]
  (2) The processed titanium oxide (B) has an average particle diameter of 0.10 to 0.24 μm(1)The thermoplastic resin composition described in 1.
[0019]
  (3) For 100 parts by weight of the polybutylene terephthalate resin (A),SaidSaid (1) which mix | blended 0.5-10 weight part of antistatic agent (C).Or (2)The thermoplastic resin composition as described.
[0020]
  (4) The polybutylene terephthalate resin (A) contains 100 to 1000 ppm of a phenolic antioxidant, and the solution haze of the polybutylene terephthalate resin (A) is 5% or less (1) to (3). The thermoplastic resin composition according to any one of
[0021]
  (5) The antistatic agent (C) is sodium alkanesulfonateAny of (1) to (4)The thermoplastic resin composition described in 1.
[0022]
  (6(1) to (1) to (1) to (2) where the total light reflectance is 92% or more when the molded product having a thickness of 2 mm is irradiated with light having a wavelength of 450 to 800 nm.5). The thermoplastic resin composition according to any one of
[0023]
  (7) (1) to (6A molded body formed by molding the thermoplastic resin composition according to any one of the above.
[0024]
  (8) (1) to (6A light reflecting plate obtained by molding the thermoplastic resin composition according to any one of the above.
[0025]
  (9) (8The lighting fixture using the light reflecting plate as described in).
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
[0027]
In the thermoplastic resin composition of the present invention, the polybutylene terephthalate resin (A) constituting the matrix resin is composed mainly of terephthalic acid or an ester-forming derivative thereof and 1,4-butanediol or an ester-forming derivative thereof. And a polymer obtained by a usual polymerization method such as a polycondensation reaction. The polybutylene terephthalate resin (A) may contain other copolymerization components as long as the properties of the polybutylene terephthalate resin are not impaired, for example, in a range of about 20% by weight or less. Preferred examples of these polymers include polybutylene terephthalate, polybutylene (terephthalate / isophthalate), polybutylene (terephthalate / adipate), polybutylene (terephthalate / sebacate), polybutylene (terephthalate / decanedicarboxylate), polybutylene (terephthalate / naphthalate). ), Poly (butylene / ethylene) terephthalate, and the like. These may be used alone or in admixture of two or more.
[0028]
The polybutylene terephthalate resin (A) can be produced as follows. That is, in producing a polybutylene terephthalate resin using (lower alkyl ester such as terephthalic acid or its ester) and 1,4-butanediol as main raw materials, oxidation is carried out in an organic titanium compound or organic tin compound solution used as a reaction catalyst. It is preferable to polymerize by adding an inhibitor. The reaction catalyst is preferably organic titanium alone. As the antioxidant, a phenol compound, a sulfur compound, and a phosphorus compound can be preferably used. Among these, a hindered phenol compound can be particularly preferably used.
[0029]
  In the present invention, the titanium oxide to be blended with the polybutylene terephthalate resin (A) is a rutile titanium oxide (a) having a coloring metal material content of 70 ppm or less, preferably 15 ppm or less. Obtained by adding treatment agent (b) containing acid hydrateAnd the content of rutile type titanium oxide (a) is 96 to 99% by weight.Processed titanium oxide (B) is used.
[0030]
Crystal forms of titanium oxide include rutile type and anatase type, but rutile type titanium oxide has an excellent concealing action, and thus has an action of improving light reflectivity. Moreover, although there exist a sulfuric acid method and a chlorine method in the manufacturing method of a rutile type titanium oxide, what was manufactured by the chlorine method is used preferably. Titanium oxide produced by the chlorine method is more colored than metallic oxide impurities such as iron (Fe), chromium (Cr) and vanadium (V) contained in the titanium oxide crystal system, compared to titanium oxide produced by the sulfuric acid method. Is extremely low and the purity is high, the whiteness is excellent, and higher light reflection performance can be obtained.
[0031]
As the rutile-type titanium oxide, those having a content of the coloring metal material of 70 ppm or less, more preferably 15 ppm or less are used. When the content of the colorable metal material is more than 70 ppm, the whiteness becomes low, and it becomes difficult to obtain a desired high light reflection performance as a molded product when the thermoplastic resin composition is molded.
[0032]
  As the surface treatment agent for the processed titanium oxide (B), a treatment agent (b) containing alumina hydrate and silicic acid hydrate is used in order to improve dispersibility with the resin. The amount of the treating agent (b) is suppressed to the minimum necessary to ensure high light reflectance.LikeThe content of rutile titanium oxide in the processed titanium oxide (B) is 96 to 99% by weight.And goodPreferably 97-98 parts by weight.
[0033]
Further, the average particle diameter of the processed titanium oxide (B) is preferably 0.10 to 0.24 μm, more preferably 0.15 to 0.22 μm. When the average particle diameter is smaller than 0.10 μm, the dispersibility is deteriorated, causing aggregation and reducing light resistance and light reflectance. Moreover, when larger than 0.24 micrometer, the external appearance defect of a molded product will generate | occur | produce and the light reflectivity will also fall.
[0034]
  The blending amount of the processed titanium oxide (B) with respect to the polybutylene terephthalate resin (A) is 5 to 10 weights of the processed titanium oxide (B) with respect to 100 parts by weight of the polybutylene terephthalate resin (A).Part,Preferably 7-9 parts by weightTheIf the amount of the processed titanium oxide (B) is less than 5 parts by weight, it is difficult to ensure light reflectivity, and if it exceeds 10 parts by weight, it is difficult to ensure fluidity and toughness of mechanical strength during molding. become.
[0035]
Antistatic properties can be imparted to the thermoplastic resin composition of the present invention by further blending an antistatic agent (C). As this antistatic agent (C), those known as surfactants are preferably used. For example, lauric acid metal salt, stearic acid metal salt, N-laurylmethylaminoacetic acid polyetheresteramide, glycerin monostearate Rate, ammonium dodecylbenzenesulfonate, maleic anhydride monoglyceride, maleic anhydride diglyceride, sodium alkanesulfonate and the like. Among them, sodium alkanesulfonate can be exemplified.
[0036]
  The blending amount of the antistatic agent is 100 parts by weight of the polybutylene terephthalate resin (A).10 parts by weight or less, preferably0.5-10 parts by weightTheAntistatic agentWhen blendingWhen the amount is less than 0.5 parts by weight, the antistatic effect is not sufficiently exhibited. When the amount is more than 10 parts by weight, the light discoloration resistance and the light reflectance are adversely affected.
[0037]
The thermoplastic resin composition comprising the polybutylene terephthalate resin (A) of the present invention as a main material has a release agent, a filler, an antioxidant, a stabilizer, and an ultraviolet absorber as long as the effects of the present invention are not impaired. Ordinary additives such as colorants, flame retardants, flame retardant aids, impact modifiers, lubricants, and small amounts of other polymers can be added.
[0038]
Mold release agents include plant waxes such as carnauba wax and rice wax, animal waxes such as beeswax and lanolin, mineral waxes such as montan wax, petroleum waxes such as paraffin wax and polyethylene wax, castor oil and its Fatty waxes such as derivatives, fatty acids and derivatives thereof may be mentioned.
[0039]
Various types of fillers are used, such as glass fibers, carbon fibers, aramid fibers, metal fibers, asbestos, whiskers and other fibrous fillers, glass beads, glass flakes, calcium carbonate, talc, mica. And spherical or amorphous powdered natural or synthetic fillers such as aluminum oxide, magnesium hydroxide, boron nitride, beryllium oxide, calcium silicate, clay, and metal powder.
[0040]
Antioxidants include 2,6-di-t-butyl-4-methylphenol, tetrakis (methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate) methane, tris (3 , 5-di-t-butyl-4-hydroxybenzyl) isocyanurate and the like, sulfur compounds such as dilauryl-3,3′-thiodipropionate and dimyristyl-3,3′-thiodipropionate And phosphorus compounds such as trisnonylphenyl phosphite and distearyl pentaerythritol diphosphite.
[0041]
Stabilizers include benzotriazole compounds including 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, and benzophenone compounds such as 2,4-dihydroxybenzophenone, mono- or distearyl phosphate, trimethyl phosphate And phosphoric acid esters.
[0042]
These various additives may be used alone or in combination since two or more kinds may have a synergistic effect. For example, the additive exemplified as the antioxidant may act as a stabilizer or an ultraviolet absorber. Some of those exemplified as stabilizers also have an antioxidant action and an ultraviolet absorption action. In other words, the classification is for convenience and does not limit the action.
[0043]
Examples of the ultraviolet absorber include 2-hydroxy-4-n-dodecyloxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone, and bis (5-benzoyl-4-hydroxy-2-methoxyphenyl) methane. Benzophenone-based ultraviolet absorbers represented by
[0044]
Examples of the ultraviolet absorber include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-tert-amylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-bis (α, α′-dimethylbenzyl) phenylbenzotriazole, 2,2′methylenebis [4- (1,1,3,3-tetramethylbutyl)- 6- (2H-benzotriazol-2-yl) phenol], methyl-3- [3-tert-butyl-5- (2H-benzotriazol-2-yl) -4-hydroxyphenylpropionate-polyethylene glycol The benzotriazole type ultraviolet absorber represented by the condensate can be mentioned.
[0045]
Further, examples of the ultraviolet absorber include 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-hexyloxyphenol, 2- (4,6-bis (2,4- And hydroxyphenyltriazine compounds such as dimethylphenyl) -1,3,5-triazin-2-yl) -5-hexyloxyphenol.
[0046]
Also, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, tetrakis (2,2,6,6) -Tetramethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate, tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) -1,2,3,4-butane Tetracarboxylate, poly {[6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl] [(2,2,6,6-tetramethyl Piperidyl) imino] hexamethylene [(2,2,6,6-tetramethylpiperidyl) imino]}, polymethylpropyl 3-oxy- [4- (2,2,6,6-tetramethyl) piperidinyl] siloxane Etc. even it can include hindered amine light stabilizers typified, such light stabilizers in combination with the ultraviolet absorber and various antioxidants, exhibit better performance in terms of weather resistance.
[0047]
  Flame retardants are halogen-based, phosphoric ester-based, metal salt-based, red phosphorus, silicon-based, metal hydrate-based, and the like, and also include anti-dripping agents. Examples of the colorant include organic dyes, organic pigments, and inorganic pigments. Other,Examples thereof include phosphorescent pigments, fluorescent dyes, flow modifiers, inorganic and organic antibacterial agents, photocatalytic antifouling agents, impact modifiers typified by graft rubber, infrared absorbers, and photochromic agents.However, no optical brightener is added.
[0048]
Moreover, as polybutylene terephthalate resin (A) used by this invention, what added 100-1000 ppm of phenolic antioxidants is preferable. This is because when an organic titanium compound is used as a reaction catalyst during the production of PBT, the organic titanium easily absorbs moisture, which causes a problem that the organic titanium compound undergoes hydrolysis to significantly reduce the catalytic activity. Moreover, this deactivated organotitanium compound becomes insoluble foreign matter in the polymer, which may adversely affect the light reflectance.
[0049]
On the other hand, when a phenolic antioxidant is used in combination with the organic titanium compound catalyst, the above problem can be avoided, and a thermoplastic resin composition comprising a polybutylene terephthalate resin having a higher light reflectance. Can be obtained. In addition, when an organic tin compound is used in combination with an organic titanium compound as a polymerization catalyst, the solution haze generated during polymerization thereby increases, and as a result, the light reflectivity of the polybutylene terephthalate resin composition decreases. It is preferable to use titanium alone.
[0050]
In order to express the above effects, it is preferable to add 100 ppm or more of a phenolic antioxidant, and addition of more than 1000 ppm leads to a decrease in light discoloration resistance and light reflectance due to discoloration of the antioxidant itself, and therefore 100 to 1000 ppm. It is preferable to be in the range.
[0051]
The solution haze is preferably 5% or less. The solution haze of the polymer represents the turbidity generated by the precipitation of the catalytic metal compound in the reaction system. When this value is high, the light reflectance is lowered. If it is 5% or less, the light reflectivity is not greatly affected. Therefore, by setting this value to 5% or less, a resin composition having a high light reflectivity can be obtained.
[0052]
In the thermoplastic resin composition of the present invention, it is preferable that these blending components are uniformly dispersed. The blending method is not particularly limited, and any method can be used. A typical example is a method of melt kneading at a temperature of 200 to 350 ° C. using a known melt mixer such as a single or twin screw extruder, a Banbury mixer, a kneader, or a mixing roll. Each component may be mixed in advance and then melt kneaded. Alternatively, for a small amount of additive component such as 1 part by weight or less with respect to 100 parts by weight of the total amount of components (A) to (C), the other components are kneaded and pelletized by the above method or the like. It can also be added before molding. In addition, although it is better that the water | moisture content adhering to each component is less and it is desirable to dry beforehand, not all the components need to be dried.
[0053]
As an example of a preferable production method, a twin screw extruder having a cylinder temperature of 230 to 300 ° C. is used, and a raw material blended with the components (A) to (C) and other additives is supplied to the extruder and kneaded. Is mentioned.
[0054]
The thermoplastic resin composition of the present invention is generally molded by known molding methods for thermoplastic resins such as injection molding, extrusion molding, blow molding, transfer molding, vacuum molding, and casting. But injection molding is preferred.
[0055]
By molding the thermoplastic resin composition of the present invention, various molded products can be molded, and particularly when molded into a light reflecting plate, those having excellent performance can be obtained. For example, when the thermoplastic resin composition is molded into a molded product having a thickness of 2 mm, the total light reflectance for light in the wavelength range of 450 to 800 nm can be 92% or more.
[0056]
Such light reflectors are used for various lighting fixtures, for example, downlights, base lights, stands, reflectors and louvers for brackets, backlight reflectors for liquid crystal monitors, automobiles, motorcycles and the like. Although it can use suitably for the reflector for lamps etc., it can use suitably especially for the reflector for downlights.
[0057]
From the above, it is possible to obtain a thermoplastic resin composition having excellent surface appearance and excellent light discoloration resistance and high light reflection performance, and a molded article molded therefrom. Furthermore, by blending an antistatic agent, a thermoplastic resin composition to which excellent antistatic properties are added and a molded article molded therefrom can be obtained. Moreover, from the molded object, the light reflection board provided with the said outstanding characteristic and a lighting fixture which has it can be obtained.
[0058]
【Example】
The present invention will be specifically described below with reference to examples.
[0059]
The blend compositions used in the examples and comparative examples are as follows.
[0060]
(1) Resin component
(A-1) Polybutylene terephthalate resin: intrinsic viscosity 0.85 (“Toraycon” 1200S ”manufactured by Toray Industries, Inc.), solution haze 15%.
(A-2) Polybutylene terephthalate resin: Inherent viscosity 0.85 ("Torcon" manufactured by Toray Industries, Inc.), solution haze 4.5%.
[0061]
The molar ratio of BG to terephthalic acid and the amount of tetrabutoxy titanate to be added were adjusted to 0.04 wt%. The temperature was raised while gradually controlling within the above range, 160 ppm of a phenolic antioxidant was added to the solution, and the esterification reaction was carried out until the reaction solution became almost transparent while distilling the water produced.
[0062]
Next, tetrabutoxy titanate as a polymerization catalyst is added to this product in an amount of 0.03 wt% with respect to the produced polymer and 220 ppm of a phenolic antioxidant, and the produced polymer is transferred to another reaction vessel under reduced pressure at 250 ° C. ( At a pressure of 133 Pa or less, polycondensation was continued until a predetermined degree of polymerization was obtained, and this time was taken as a polymerization time, and discharged to obtain a pellet made of a polyester resin composition. This pellet was treated at 196 ° C. under a reduced pressure of 0.2 kPa for 7.5 hours to obtain a used polybutylene terephthalate resin.
[0063]
(A-3) Polycarbonate resin: A polycarbonate resin having a viscosity average molecular weight of 20000 (Mitsubishi Engineering Plastics Co., Ltd. “Iupilon” 3000) and bisphenol A as starting materials.
[0064]
(2) Titanium oxide component
(B-1) Processed titanium oxide (Ishihara Sangyo Co., Ltd. “Taipeke” CR63)
An average particle size of 0.21 μm, a rutile type 2 titanium oxide having a content of 13 ppm of a coloring metal material produced by the chlorine method, and only two kinds of alumina hydrate and silicate hydrate are used as treatment agents. used. The content of rutile titanium oxide is 97% by weight.
[0065]
(B-2) Processed titanium oxide (Ishihara Sangyo Co., Ltd. “Taipeke” CR60)
Alumina hydrate alone was used as a treating agent for rutile type 1 titanium oxide having an average particle size of 0.21 μm and a content of 13 ppm of a coloring metal material produced by the chlorine method. The rutile titanium oxide content is 95% by weight.
[0066]
(B-3) Processed titanium oxide (Ishihara Sangyo Co., Ltd. “Typaque” CR50-2) average particle size of 0.25 μm, rutile type 2 having a content of 13 ppm of a colored metal material produced by the chlorine method Alumina hydrate alone was used as the treating agent for the class of titanium oxides. Titanium oxide content is 95% by weight.
[0067]
(3) Antistatic component
(C-1) Surfactant ("Electro Stripper" PC-3 manufactured by Kao Corporation)
(4) Fluorescent whitening agent (“Whiteford” manufactured by Sumika Color Co., Ltd.).
[0068]
(5) Resin stabilizer (“n-hexadecyltrimethoxysilane” manufactured by Toray Dow Corning Silicone Co., Ltd.).
[0069]
The characteristic values used in Examples and Comparative Examples were evaluated by the following measurement methods.
(1) Total light reflectance
The total light reflectance at a wavelength of λ = 555 nm was measured with a self-recording spectrophotometer U-4000 manufactured by Hitachi, Ltd. using a reflector for a thin (lamp horizontal) downlight fixture shown in FIG.
[0070]
(2) Surface appearance
After forming the same reflector as the measurement of the total light reflectance described above, the appearance of the light reflecting surface was visually confirmed, and the surface state was determined by ◎, ○, Δ, × as follows.
A: No abnormalities such as silver and discoloration are observed.
○: Some abnormalities such as silver and discoloration are observed.
Δ: Abnormalities such as silver and discoloration are observed.
X: Abnormalities such as remarkable silver and discoloration are observed.
[0071]
(3) Light resistance (Practical lighting test)
Using the same reflector as the total light reflectance measurement described above, using a compact fluorescent lamp 32W (manufactured by Matsushita Electronics Co., Ltd .: FHT32EXN), 24 hours continuous lighting (reflector maximum temperature 130 ° C.), test period 3 months Thereafter, the total light reflectance at a wavelength λ = 555 nm was measured with a self-recording spectrophotometer U-4000 manufactured by Hitachi, Ltd., and the degree of discoloration was judged by ◎, ○, Δ, and × as follows by the decrease in the reflectance. .
A: Reflectance decrease is within 3%, no discoloration is observed.
○: Reflectance decrease is over 3% and within 10%, and some discoloration is observed.
Δ: Reflectivity decreased over 10% and within 20%, discoloration observed.
X: Reflectivity decreased by more than 20% and significant discoloration was observed.
[0072]
(4) Dust adhesion (atmospheric exposure test)
Using the same reflector as the total light reflectance measurement described above, leave it in the indoor atmosphere, visually check the appearance of the light reflecting surface after 3 months of the test period, and the degree of dust adhesion as follows: , ○, Δ, ×.
A: Dust adhesion is not observed at all.
○: Dust adhesion is slightly observed.
Δ: Adherence of dust is observed.
X: Significant dust adhesion is observed.
[0073]
(5) Solution haze
The polymer solution haze represents the turbidity generated by the precipitation of the catalytic metal compound in the reaction system. Phenol and ethane tetrachloride (60:40 wt%) are used as a mixed solvent, and 5.4 g of polymer chips are heated and dissolved in 40 ml of the solvent. The polymer solution was placed in a 30 ml quartz cell and measured with an integrating sphere haze meter (manufactured by Nippon Seimitsu Optics).
[0074]
Examples 1-4
Components (A) to (C) were blended in combinations shown in Table 1.
Example 1 is a formulation in which 8 parts by weight of a specified processed titanium oxide and 0.75 parts by weight of an antistatic agent are blended with a PBT having a solution haze of 15%.
Example 2 is a formulation in which 10 parts by weight of the designated processed titanium oxide and 0.75 parts by weight of the antistatic agent are blended with PBT having a solution haze of 15%.
Example 3 is a formulation in which 8 parts by weight of the designated processed titanium oxide is blended with PBT to which 380 ppm of a phenolic antioxidant is added and the solution haze is reduced to 5% or less.
Example 4 is a formulation obtained by adding an antistatic agent to Example 3.
[0075]
The manufacturing method of the material described in each Example is as follows. That is, it was manufactured using a twin screw extruder having a screw diameter of 57 mmφ set at a cylinder temperature of 250 ° C. (A) Component (polybutylene terephthalate resin), (B) component (processed titanium oxide), (C) component (antistatic agent) and other additives are all supplied from the original charging section and melt-kneaded, from the die The discharged strand was cooled in a cooling bath and then pelletized with a strand cutter.
[0076]
Each material obtained was dried by a hot air dryer at 130 ° C. for 3 hours or longer, and then molded by the method described in the evaluation method, and the total light reflectance, surface appearance, light resistance, and dust adhesion were measured. The results are also shown in Table 1. All of the obtained compositions were excellent in total light reflectance, surface appearance, light resistance, and dust adhesion.
[0077]
Comparative Examples 1-6
Table 1 shows the formulation of the comparative example and the evaluation results.
[0078]
In Comparative Example 1, 8 parts by weight of the specified processed titanium oxide was blended with PBT having a melt haze of 15%. However, since the content of titanium oxide is as low as 95% by weight and the surface treatment agent is different, The reflectivity did not develop more than 92%.
[0079]
In Comparative Example 2, 8 parts by weight of processed titanium oxide was blended with PBT having a melt haze of 15%, but the titanium oxide content was as low as 95% by weight, and the titanium oxide particle size was as large as 0.25 μm. The total light reflectance is further lowered.
[0080]
Comparative Example 3 is the same as Comparative Example 1 in which 10 parts by weight of processed titanium oxide and 0.3 parts by weight of an antistatic agent are blended, but the total light reflectance does not develop 92% or more, and dust Adhesion was also observed.
[0081]
In Comparative Example 4, 12 parts by weight of an antistatic agent was added to the formulation of Example 1, but the total light reflectance was lowered and discoloration after the light resistance test was also observed.
[0082]
Comparative Example 5 is a system in which a fluorescent brightener is added to the formulation of Example 1. Although effective in improving the initial light reflectivity, a significant decrease in light discoloration resistance was observed.
[0083]
Comparative Example 6 is a system in which 8 parts by weight of the specified processed titanium oxide is blended with polycarbonate, but the total light reflectance, light discoloration resistance, and molded appearance are not satisfactory.
[0084]
Comparative Example 7 was a formulation in which a resin stabilizer was added to the formulation of Comparative Example 6, but the molding appearance was improved, but no effect of improving light reflectance and light discoloration resistance was observed.
[0085]
[Table 1]

[0086]
【The invention's effect】
According to the present invention, a thermoplastic resin composition comprising a polybutylene terephthalate resin having excellent weather resistance and light reflection performance, and a molding comprising the same can be obtained without generating silver during molding. A body etc. can be obtained. Furthermore, when an antistatic agent is blended, excellent antistatic properties can be obtained together.
[Brief description of the drawings]
FIG. 1 is a perspective view illustrating a thin (lamp lateral) downlight apparatus used in an evaluation test of the present invention.

Claims (9)

While blending 5 to 10 parts by weight of processed titanium oxide (B) and 10 parts by weight or less of antistatic agent (C) with respect to 100 parts by weight of polybutylene terephthalate resin (A) , avoid adding a brightening agent. The processed titanium oxide (B) is a process comprising a rutile type titanium oxide (a) having a coloring metal material content of 70 ppm or less containing alumina hydrate and silicate hydrate. A thermoplastic resin composition obtained by adding the agent (b) and having a content of the rutile titanium oxide (a) in the processed titanium oxide (B) of 96 to 99% by weight . The thermoplastic resin composition according to claim 1 , wherein the average particle diameter of the processed titanium oxide (B) is 0.10 to 0.24 μm. The thermoplastic resin composition according to claim 1 or 2 , wherein 0.5 to 10 parts by weight of the antistatic agent (C) is blended with 100 parts by weight of the polybutylene terephthalate resin (A). The polybutylene terephthalate resin (A) contains 100~1000ppm a phenolic antioxidant, and according to any one of claims 1 to 3 solution haze of the polybutylene terephthalate resin (A) is 5% or less Thermoplastic resin composition. The thermoplastic resin composition according to any one of claims 1 to 4, wherein the antistatic agent (C) is sodium alkanesulfonate. The thermoplastic resin composition according to any one of claims 1 to 5 , which has a total light reflectance of 92% or more when a molded product having a thickness of 2 mm is irradiated with light having a wavelength of 450 to 800 nm. The molded object formed by shape | molding the thermoplastic resin composition in any one of Claims 1-6 . The light reflection board formed by shape | molding the thermoplastic resin composition in any one of Claims 1-6 . A lighting fixture using the light reflecting plate according to claim 8 .

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