JP5637529B2 - Lighting cover made of polycarbonate resin - Google Patents

Description

  The present invention relates to a lighting cover made of polycarbonate resin used for a lighting fixture, particularly an LED lamp. More specifically, the flame retardancy is improved without containing halogen-based flame retardants such as chlorine and bromine compounds and phosphorus-based flame retardants, and mechanical properties such as excellent impact resistance inherent in polycarbonate resin, The present invention relates to an illumination cover made of polycarbonate resin having high optical characteristics without impairing performance such as fluidity.

  For lighting covers such as lighting fixtures, indicator lamps, and fluorescent tubes, highly transparent materials are required so as not to reduce the amount of light. However, when the light source is seen through, it is felt dazzling with the naked eye. Therefore, there is a demand for a material that does not reduce the amount of light and does not show through the light source.

  Conventionally, frosted glass and milky white vinyl chloride resin have been used for lighting covers, but the former has the problem of handling that it is easy to break and the problem of relatively heavy weight. Synthetic lighting covers are also used. In recent years, the development of LED lighting fixtures has been accelerated with the advent of high-intensity white LEDs. LED lighting fixtures are highly expected as next-generation lighting fixtures because of the high brightness, long life, and energy saving of LED light sources.

  However, the LED lighting fixture has a problem in that the LED chip, which is a light source, emits heat to the back side (substrate side) when emitting light, so that heat accumulates inside the lighting cover and generates high heat. In order to solve this problem, means such as installation of a heat radiating member such as aluminum die cast and cooling by a heat pipe have been proposed. However, these means complicate the structure and lead to an increase in cost, so that a fundamental improvement has been desired.

As a synthetic resin for a lighting cover having such performance, polycarbonate resin having excellent transparency, impact resistance, heat resistance, and flame retardancy has attracted attention.
In order to prevent the visibility of the light source, a method (Patent Document 1) in which a light diffusing agent such as calcium carbonate, barium sulfate, silicon oxide, and titanium oxide is added to and mixed with the polycarbonate resin has been proposed. Because it has basic chemical properties, it may cause destabilization of polycarbonate resin, especially when it receives a thermal history such as molding, causing problems such as coloration (yellowing) and a decrease in molecular weight. was there.

   In order to solve this problem, there has been proposed a method (Patent Document 2) that suppresses molecular weight reduction and yellowing during molding by combining calcium carbonate and polyorganohydrogensiloxane, and calcium carbonate has a crystal structure. Due to the cubic shape, there is a problem that a sufficient effect cannot be obtained for scattering light.

  As a method of using a spherical light diffusing agent that can be used for a polycarbonate resin, methods of adding acrylic fine particles having a refractive index different from that of the polycarbonate resin (Patent Documents 3 and 4) have been proposed. Simply kneading the agent into the polycarbonate resin only improves the optical properties such as light transmittance and light diffusivity, and further improvements have been desired in terms of flame retardancy.

Japanese Patent Publication No.57-24816 JP 2000-169695 A JP-A 63-137911 Japanese Patent Laid-Open No. 10-46018

  As a technique for imparting flame retardancy to a polycarbonate resin, a method in which chlorine, a bromine compound, or a phosphorus compound is blended as a flame retardant is employed. However, chlorine and bromine-based flame retardants exhibit excellent flame retardant effects, but have problems such as corrosion of molding machine screws and product molds during injection molding. Moreover, although the phosphorus-based flame retardant is mainly used as a condensed phosphate ester-based flame retardant, there is a problem that an extreme decrease in heat resistance or impact strength occurs. In view of these remarkable physical properties and environmental considerations, it is desired to use a flame retardant that does not contain halogen compounds such as bromine and chlorine and phosphorus compounds.

Furthermore, it is necessary to impart flame retardancy while maintaining excellent optical characteristics in the use of lighting covers, and it has been desired to develop a lighting cover made of synthetic resin that satisfies both of these characteristics at the same time.

  An object of the present invention is to provide a lighting cover made of polycarbonate resin having the above-mentioned problems, that is, high optical characteristics and excellent flame retardancy, and particularly suitable for an LED light source.

  As a result of intensive studies to solve the above problems, the present inventors have obtained a specific silicone-based flame retardant, an organometallic salt compound, and a fiber-forming fluorine-containing polymer without using a halogen-based flame retardant. It was found that a polycarbonate resin lighting cover having high optical properties and excellent flame retardancy can be obtained by combining the use with a light diffusing agent, and the present invention has been completed.

That is, the present invention is a polycarbonate resin lighting cover,
(1) The lighting cover is formed by molding a polycarbonate resin composition containing the following components (A) to (E), and (2) UL94 test method (for plastic materials for equipment parts) Based on a flammability test), when a combustion test was performed using a test piece having a thickness of 1.5 mm formed by molding the resin composition, it had a V-0 rating, and (3) based on JIS K7361, The total light transmittance measured using a test piece having a thickness of 1.5 mm formed by molding the resin composition is 50% or more, and the haze is 80% or more. The present invention provides a polycarbonate resin lighting cover, wherein the lighting cover is a lighting cover for a lighting fixture using an LED light source.
(A) Polycarbonate resin 100 parts by weight (B) 0.01 to 0.5 part by weight of an organometallic salt compound which is a metal salt of aromatic sulfonamide, a metal salt of aromatic sulfonic acid or a metal salt of perfluoroalkanesulfonic acid (C) Fiber-forming fluorine-containing polymer 0.05 to 1 part by weight (D) R ¹ R ² R ³ SiO _1/2 (wherein R ¹ , R ² and R ³ are the same or different, carbon A monovalent hydrocarbon group which may be substituted of 1 to 6). The organopolysiloxane containing a siloxane unit represented by formula (1), which is essentially a phenyl group as a substituent bonded to a silicon atom. Each containing 2 wt% or less of an alkoxy group and / or a hydroxyl group, and having a weight average molecular weight of 2,000 or more Part (E) Light diffusing agent 0.01-5 parts by weight

  Further, in the polycarbonate resin lighting cover of the present invention, the polycarbonate resin composition to be used further comprises (F) up to 0.3 parts by weight of a brightening agent and / or (G) 1 weight of an ultraviolet absorber. May be included (on the basis of 100 parts by weight of (A) polycarbonate resin, respectively). (F) By containing a fluorescent brightening agent, the hue is improved and further excellent optical properties can be imparted. Moreover, weather resistance improves by containing (G) ultraviolet absorber, and it can be used conveniently also in the lighting fixture of an outdoor use.

  The polycarbonate resin lighting cover of the present invention provides excellent flame retardancy without impairing the excellent optical properties of the polycarbonate resin, so that it can be used for lighting, indicator lamps, fluorescent tubes, lighting domes, top lights, arcades, roads It can be suitably used as a lighting cover for a lighting device such as a side wall plate. In particular, it is characterized by high brightness and high directivity, and is suitable for use as a lighting cover of a lighting fixture using an LED light source that emits heat to the back side (base side) when emitting light.

  The (A) polycarbonate resin used in the present invention is obtained by a phosgene method in which various dihydroxy diaryl compounds and phosgene are reacted, or a transesterification method in which a dihydroxy diaryl compound and a carbonate such as diphenyl carbonate are reacted. A typical example of the polymer is a polycarbonate resin produced from 2,2-bis (4-hydroxyphenyl) propane (bisphenol A).

  Examples of the dihydroxydiaryl compound include bisphenol 4-, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) butane, 2, 2-bis (4-hydroxyphenyl) octane, bis (4-hydroxyphenyl) phenylmethane, 2,2-bis (4-hydroxyphenyl-3-methylphenyl) propane, 1,1-bis (4-hydroxy-3) -Tert-butylphenyl) propane, 2,2-bis (4-hydroxy-3-bromophenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis ( Bis (hydroxyaryl) alkanes such as 4-hydroxy-3,5-dichlorophenyl) propane, 1,1- (4-hydroxyphenyl) cyclopentane, bis (hydroxyaryl) cycloalkanes such as 1,1-bis (4-hydroxyphenyl) cyclohexane, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3 Dihydroxy diaryl ethers such as 3,3'-dimethyldiphenyl ether, dihydroxy diaryl sulfides such as 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxy-3,3 ' Dihydroxy diaryl sulfoxides such as dimethyldiphenyl sulfoxide, dihydroxy diary such as 4,4′-dihydroxydiphenyl sulfone, 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfone Sulfone, and the like. These are used individually or in mixture of 2 or more types. In addition to these, piperazine, dipiperidyl hydroquinone, resorcin, 4,4'-dihydroxydiphenyl, and the like may be mixed and used.

  Furthermore, the above dihydroxyaryl compound and a trivalent or higher phenol compound as shown below may be used in combination. Trihydric or higher phenols include phloroglucin, 4,6-dimethyl-2,4,6-tri- (4-hydroxyphenyl) -heptene, 2,4,6-dimethyl-2,4,6-tri- (4 -Hydroxyphenyl) -heptane, 1,3,5-tri- (4-hydroxyphenyl) -benzol, 1,1,1-tri- (4-hydroxyphenyl) -ethane and 2,2-bis- [4 4- (4,4′-dihydroxydiphenyl) -cyclohexyl] -propane and the like.

  The viscosity average molecular weight of the polycarbonate resin is usually 10,000 to 100,000, preferably 15,000 to 35,000, and more preferably 17,000 to 28,000. In producing such a polycarbonate resin, a molecular weight regulator, a catalyst and the like can be used as necessary.

Examples of the (B) organometallic salt compound used in the present invention include an aromatic sulfonamide metal salt represented by the following general formula 1 or 2, and an aromatic sulfonic acid metal salt represented by the following general formula 3. And metal salts of perfluoroalkanesulfonic acid.
General formula 1

（式中、Ａｒはフェニル基又は置換フェニル基を、Ｍは金属陽イオンを表わす。）

(In the formula, Ar represents a phenyl group or a substituted phenyl group, and M represents a metal cation.)

General formula 1

（式中、Ａｒはフェニル基又は置換フェニル基を、Ｒ'はスルホニル又はカルボニルを含む有機基を、Ｍは金属陽イオンを表わす。ただし、ＡｒとＲとが結合してもよい。）
一般式３

(In the formula, Ar represents a phenyl group or a substituted phenyl group, R ′ represents an organic group containing sulfonyl or carbonyl, and M represents a metal cation. However, Ar and R may be bonded.)
General formula 3

（式中、Ｒ’’、及びＲ’’’は炭素原子が１〜６個の脂肪族基又は１〜２個のフェニル基若しくは置換フェニル基を、ＡはＳＯ_３Ｍ（Ｍは、金属陽イオンを表す。）基を表わす。）

(Wherein R ″ and R ′ ″ are an aliphatic group having 1 to 6 carbon atoms or a phenyl group or substituted phenyl group having 1 to 2 carbon atoms, A is SO ₃ M (M is a metal positive group) Represents an ion) represents a group)

Preferred examples of the metal salt of aromatic sulfonamide include a metal salt of saccharin, a metal salt of N- (p-tolylsulfonyl) -p-toluenesulfimide, and a metal of N- (N′-benzylaminocarbonyl) sulfanilimide. And metal salts of N- (phenylcarboxyl) -sulfanilimide. In addition, as the metal salt of aromatic sulfonic acid, metal salt of diphenylsulfone-3-sulfonic acid, metal salt of diphenylsulfone-3,3′-disulfonic acid, and metal salt of diphenylsulfone-3,4′-disulfonic acid Is mentioned. These may be used alone or in combination.
Suitable metals include Group I metals (alkali metals) such as sodium and potassium, or Group II metals, copper, aluminum and the like, with alkali metals being particularly preferred.

Among these, in particular, potassium salt of N- (p-tolylsulfonyl) -p-toluenesulfimide, potassium salt of N- (N′-benzylaminocarbonyl) sulfanilimide, or potassium salt of diphenylsulfone-3-sulfonic acid Are preferably used, and more preferably a potassium salt of N- (p-tolylsulfonyl) -p-toluenesulfoimide or a potassium salt of N- (N′-benzylaminocarbonyl) sulfanilimide.

  Preferable examples of the metal salt of aromatic sulfonic acid include p-toluenesulfonic acid, p-styrenesulfonic acid, 1-naphthalenesulfonic acid, dimethyl-5-sulfonic acid isophthalate, 2,6-naphthalenedisulfonic acid, and benzenesulfone. Acid, benzenedisulfonic acid, dimethyl 2,4,6-trichloro-5-sulfoisophthalate, 2,5-dichlorobenzenesulfonic acid, 2,4,5-trichlorobenzenesulfonic acid, p-iodobenzenesulfonic acid, 7- An alkali metal salt such as amino-1,3-naphthalenedisulfonic acid is preferred. These may be used alone or in combination.

Of these, one or more sodium salts selected from dimethyl 2,4,6-trichloro-5-sulfoisophthalate, 2,5-dichlorobenzenesulfonic acid, and 2,4,5-trichlorobenzenesulfonic acid And / or potassium salt; in p-toluenesulfonic acid, p-styrenesulfonic acid, 1-naphthalenesulfonic acid, isophthalic acid dimethyl-5-sulfonic acid, 2,6-naphthalenedisulfonic acid, benzenesulfonic acid, benzenedisulfonic acid One or two or more sodium salts selected from the above can be preferably used.

  Preferred examples of the metal salt of perfluoroalkanesulfonic acid include metal salt of perfluoromethanesulfonic acid, metal salt of perfluoroethanesulfonic acid, metal salt of perfluoropropanesulfonic acid, metal salt of perfluorobutanesulfonic acid, Examples thereof include metal salts of perfluoromethylbutanesulfonic acid, metal salts of perfluorohexanesulfonic acid, metal salts of perfluoroheptanesulfonic acid, and metal salts of perfluorooctanesulfonic acid. These may be used alone or in combination. Of these, the potassium salt of perfluorobutanesulfonic acid can be suitably used.

  (B) The compounding quantity of an organometallic salt compound is 0.01-0.5 weight part with respect to 100 weight part of polycarbonate resin (A). If the blending amount is less than 0.01 parts by weight, it is difficult to obtain a flame retardant effect, and if it exceeds 0.5 parts by weight, the thermal stability at the time of injection molding may be inferior. Since it adversely affects the moldability and impact strength, it is not preferable. This amount is more preferably 0.01 to 0.1 parts by weight, still more preferably 0.01 to 0.05 parts by weight.

  The (C) fiber-forming type fluorine-containing polymer used in the present invention is preferably (A) one that forms a fiber structure (fibril structure) in a polycarbonate resin, such as polytetrafluoroethylene and tetrafluoroethylene. Examples thereof include a system copolymer (for example, tetrafluoroethylene / hexafluoropropylene copolymer, etc.), a partially fluorinated polymer as shown in US Pat. No. 4,379,910, a polycarbonate produced from a fluorinated diphenol, and the like.

  (C) The compounding quantity of a fiber formation type fluorine-containing polymer is 0.05-1 weight part with respect to 100 weight part of (A) polycarbonate resin. If the blending amount is less than 0.05 parts by weight, the effect of preventing dripping at the time of combustion is inferior, and if it exceeds 1 part by weight, granulation becomes difficult, which hinders stable production. This amount is more preferably 0.1 to 0.5 parts by weight, still more preferably 0.1 to 0.3 parts by weight.

The organopolysiloxane (D) used in the present invention contains a monofunctional siloxane unit represented by R ¹ R ² R ³ SiO _1/2 and has an essential substituent bonded to a silicon atom in the molecule. As a phenyl group. Here, R ¹ , R ² and R ³ are each selected from the same or different monovalent hydrocarbon group having 1 to 6 carbon atoms which may be substituted, for example, methyl group, ethyl group, propyl group , Alkyl groups such as butyl group, hexyl group and cyclohexyl group, alkenyl groups such as vinyl group and allyl group, phenyl group and the like, and methyl group and phenyl group are particularly preferable.

(D) The phenyl group content of the organopolysiloxane greatly affects the moldability of the resin composition, the transparency of the molded product, the mechanical strength, and the like. The higher the phenyl group content of the organopolysiloxane, the higher the dispersibility and compatibility with the (A) polycarbonate resin, and the better the moldability, transparency, and mechanical strength. Therefore, the proportion of phenyl groups in the total organic substituents bonded to silicon atoms of the organopolysiloxane molecule is preferably 30 to 90% by weight, more preferably 50 to 90% by weight. The phenyl group content is defined as follows. That is, (D) average composition formula (C ₆ H ₅ ) _m R _n Si (OR ′) _p (OH) _q O _{(4-mnpq) / 2}
(In the formula, R represents an organic substituent other than a phenyl group and an alkoxy group, is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 6 carbon atoms, and R ′ is a monovalent hydrocarbon having 1 to 6 carbon atoms. Is a group represented by the following formula (MW represents the molecular weight of each substituent).
Phenyl group content (wt%)
= {MW (C ₆ H ₅ ) × m × 100} / {MW (C ₆ H ₅ ) × m + MW (R) × n + MW (R ′) × p}

In the case where (D) the organopolysiloxane is represented by the above composition formula, R is preferably an alkyl group, particularly a methyl group, and R ′ is also preferably an alkyl group. A tertiary alkyl group is preferred. m, n, p, q are 0.5 ≦ m ≦ 2.0, 0.1 ≦ n ≦ 2.3, 0 ≦ p ≦ 0.13, 0 ≦ q ≦ 0.17, 0.92 ≦ m + n + p + q. It is preferably selected from positive numbers satisfying ≦ 2.85.

  (D) Organopolysiloxane makes it possible to recycle the resin composition, but in order not to lower the moldability, appearance and transparency of the molded product, the number of reactive groups in the molecule is as small as possible. It is important to. For this reason, it is necessary to make the content of alkoxy groups and hydroxyl groups as substituents bonded to silicon atoms in the molecule equal to or less than a certain amount.

  The alkoxy group content is 2% by weight or less. By reducing the amount of alkoxy groups that contribute to the hydrolysis reaction, it is possible to obtain a lighting cover with significantly improved moisture resistance and excellent transparency. From the point of hydrolysis reactivity and flame retardancy of the alkoxy group, the remaining alkoxy group is further selected from 2 to 3 carbon atoms selected from isopropoxy group, 2-butoxy group, tert-butoxy group, cyclohexyloxy group and the like. It is preferable to use a tertiary and / or tertiary alkoxy group. On the other hand, the hydroxyl group content is 2% by weight or less. More preferably, it is 1 weight% or less. The smaller the number of these alkoxy groups and hydroxyl groups, the better.

The weight average molecular weight of (D) organopolysiloxane is 2,000 or more. When the weight average molecular weight is less than 2,000, the flame retardancy is lowered, which is not preferable. Preferably it is 2,000-50,000, More preferably, it is 2,000-20,000.

Further, (D) the organopolysiloxane is represented by 10 to 75 mol% of monofunctional siloxane units represented by R ¹ R ² R ³ SiO _1/2 in the molecule and R ⁴ R ⁵ SiO _2/2. 0 to 80 mol% of the bifunctional siloxane unit, 0 to 80 mol% of the trifunctional siloxane unit represented by R ⁶ SiO _3/2 , and 0 of the tetrafunctional siloxane unit represented by SiO _4/2. Those containing ˜15 mol% can be used. Preferably, the monofunctional siloxane unit represented by R ¹ R ² R ³ SiO _1/2 is 10 to 50 mol%, and the bifunctional siloxane unit represented by R ⁴ R ⁵ SiO _2/2 is 0 to 80 mol%. A compound containing 10 to 80 mol% of a trifunctional siloxane unit represented by mol%, R ⁶ SiO _3/2 and 0 to 10 mol% of a tetrafunctional siloxane unit represented by SiO _4/2 is used. . Here, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ are each selected from the same or different monovalent hydrocarbon groups having 1 to 6 carbon atoms which may be substituted, An alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group and a cyclohexyl group, an alkenyl group such as a vinyl group and an allyl group, and a phenyl group, with a methyl group and a phenyl group being particularly preferred.

  In general, the structure of organopolysiloxane is composed of monofunctional siloxane units (M units), bifunctional siloxane units (D units), trifunctional siloxane units (T units), and tetrafunctional siloxane units (Q units). It is configured by any combination. In the present invention, preferred combinations of these units are M / D system, M / T system, M / D / T system, M / D / Q system, M / T / Q system, M / D / T / The Q system, more preferably the M / D / T system, provides good flame retardancy and dispersibility. On the other hand, the molecular weight is too low for the M alone system and the flame retardant effect is not exerted. In the M / Q system, the inorganic properties of the organopolysiloxane are too strong and the dispersibility in the synthetic resin containing the aromatic ring is poor. There is. For the same reason, in the M / D / Q system and the M / D / T / Q system, the content of the Q unit is preferably 15 mol% or less, more preferably 10 mol% or less.

  The (D) organopolysiloxane contains only methyl groups as organic substituents other than phenyl groups and residual alkoxy groups in the molecule, that is, R = methyl group in the above average composition formula. It is preferable from the viewpoint of ease and cost. Further, (D) the organopolysiloxane is preferably a solid resin at room temperature which is soluble in an organic solvent such as toluene and has a softening point of 50 ° C. or higher.

  (D) The compounding quantity of organopolysiloxane is 0.01-0.5 weight part with respect to 100 weight part of polycarbonate resin (A). If the blending amount is out of this range, the flame retardancy is lowered, which is not preferable. Preferably it is 0.01-0.3 weight part, More preferably, it is the range of 0.03-0.1 weight part.

The (E) light diffusing agent used in the present invention is not particularly limited as long as it is a light diffusing agent that scatters light inside the (A) polycarbonate resin, but particularly shows a spherical form. Are preferably used. Examples of the light diffusing agent exhibiting a spherical shape include silicone-based and acrylic light diffusing agents. In particular, an acrylic light diffusing agent can be suitably used in lighting cover applications that require light transmission.
Momentive Japan's Tospearl 120S is commercially available as a silicone light diffusing agent, and Gantz Pearl GM0449S by Gantz Kasei Co., Ltd. and Chemisnow KMR-3TA by Soken Chemical Co., Ltd. are commercially available as acrylic light diffusing agents.

   (E) The compounding quantity of a light-diffusion agent is 0.01-5 weight part per 100 weight part of (A) polycarbonate resin. If the blending amount is less than 0.01 parts by weight, the light scattering inside the (A) polycarbonate resin cannot be obtained sufficiently and the effect of preventing the visibility of the light source is inferior, and if it exceeds 5 parts by weight, the transmittance is significantly reduced. This is not preferable. More preferably, it is 0.01-3 weight part, More preferably, it is the range of 0.01-2 weight part.

  The (F) fluorescent brightening agent used in the present invention is not limited as long as it absorbs light in the ultraviolet region and emits an excitation peak in the vicinity of 400 nm, but particularly in the visible light region. Those that absorb less light are preferably used. As the optical brightener, Hostalux KSN manufactured by Clariant Japan and Kayalite OS manufactured by Nippon Kayaku Co., Ltd. are commercially available.

  (F) The compounding quantity of a fluorescent whitening agent is to 0.3 weight part per 100 weight part of (A) polycarbonate resin. If the blending amount exceeds 0.3 parts by weight, thermal decomposition tends to occur, such being undesirable. (F) By blending a fluorescent brightening agent, the yellowishness is alleviated and a good hue is obtained.

  Examples of the (G) ultraviolet absorber used in the present invention include one or more ultraviolet absorbers selected from benzotriazole, benzophenone, triazine, and malonate. Tinuvin 329 manufactured by Ciba Specialty Chemical Company, LA31 manufactured by Asahi Denka Kogyo Co., Ltd., and Tinuvin 1577 manufactured by Ciba Specialty Chemical Company are commercially available.

  The blending amount of the (G) ultraviolet absorber is up to 1 part by weight per 100 parts by weight of the (A) polycarbonate resin. If the amount exceeds 1 part by weight, thermal decomposition tends to occur, which is not preferable. (G) A weather resistance becomes favorable by mix | blending a ultraviolet absorber.

  There is no restriction | limiting in any embodiment and order for obtaining the polycarbonate resin composition containing said various compounding components. For example, (A) a polycarbonate resin, (B) an organometallic salt compound, (C) a fiber-forming fluoropolymer, (D) an organopolysiloxane and (E) a light diffusing agent and optionally (F) fluorescent whitening Agent and / or (G) UV absorber is weighed in an arbitrary amount, mixed together with a tumbler, riboblender, high-speed mixer, etc., and then the mixture is melted using a normal single-screw extruder or twin-screw extruder A method of kneading and pelletizing, or a method in which individual or all of individual components are weighed separately, introduced into an extruder from a plurality of feeders, and melt-mixed. Can be blended at a high concentration, once melt-mixed and pelletized to form a master batch, and then the master batch and the remaining components can be mixed in a desired ratio. Then, when these components are melt-mixed, arbitrary conditions such as the position to be fed into the extruder, the extrusion temperature, the screw rotation speed, and the supply amount can be selected and pelletized.

  The polycarbonate resin composition used in the polycarbonate resin lighting cover of the present invention is further provided with a heat stabilizer, an antioxidant, a colorant, a filler, a release agent, and a softening material within the range not impairing the effects of the present invention. , Additives such as antistatic agents, impact modifiers, and other polymers may be blended.

  The method for obtaining the flame-retardant lighting cover of the present invention is not particularly limited as long as it is generally a method of molding a thermoplastic resin, and examples thereof include injection molding, sheet extrusion molding, and profile extrusion molding.

  EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, “%” and “part” in the examples are based on weight standards.

The raw materials used are as follows.
(A) Polycarbonate resin:
Polycarbonate resin synthesized from bisphenol A and phosgene (Sumitomo Dow Caliber 200-13, viscosity average molecular weight: 21500,
(Hereinafter abbreviated as PC)
(B) Organometallic salt compound Paratoluenesulfonic acid sodium salt (hereinafter abbreviated as “metal salt”)
(C) Fiber-forming fluorine-containing polymer:
Polytetrafluoroethylene (Daikin Polyflon FA500C)
(Hereafter, abbreviated as “PTFE”.)
(D) Organopolysiloxane:
Organopolysiloxanes 1 to 6 obtained in Synthesis Examples 1 to 6 below were used.

Synthesis example 1
A 1 L flask equipped with a stirrer, a cooling device, and a thermometer was charged with 288 g (16 mol) of water and 93 g of toluene, and heated to an internal temperature of 80 ° C. in an oil bath. A dropping funnel was charged with 148 g (0.7 mol) of phenyltrichlorosilane, 51 g (0.2 mol) of diphenyldichlorosilane and 13 g (0.1 mol) of dimethyldichlorosilane, and dropped into the flask over 1 hour while stirring. After completion of the dropwise addition, the mixture was further aged by continuing stirring at an internal temperature of 80 ° C. for 1 hour. Subsequently, 27 g (0.25 mol) of trimethylchlorosilane was dropped into the flask over 10 minutes while stirring, and after completion of the dropwise addition, the mixture was further aged by continuing stirring at an internal temperature of 80 ° C. for 30 minutes. After adding 100 g of toluene, the water layer that had been separated by leaving to stand while cooling to room temperature was removed, and subsequently 10% sodium sulfate aqueous solution was mixed, stirred for 10 minutes, and then left to stand for 30 minutes to separate the separated water. The water washing operation for removing the layer was repeated until the toluene layer became neutral, and the reaction was stopped. An ester adapter was attached, and the toluene layer containing the organopolysiloxane was heated and refluxed to remove water from the toluene layer. After the internal temperature reached 110 ° C., the mixture was further continued for 1 hour, and then cooled to room temperature. The obtained organopolysiloxane solution was filtered to remove insolubles, and then toluene and low-molecular siloxane were removed by distillation under reduced pressure to obtain 135 g of solid phenyl group-containing organopolysiloxane-1.
The obtained organopolysiloxane-1 contains 15 mol% of M units, 25 mol% of D units, and 60 mol% of T units, and the phenyl group content in all organic substituents is 87 wt%, The content was 0% by weight, the hydroxyl group content was 0.4% by weight, the appearance was a colorless transparent solid, and the weight average molecular weight was 9,200. The softening point of this resin was 96 ° C.

Synthesis example 2
720 g (40 mol) of water and 400 g of toluene were charged into a 2 L flask equipped with a stirrer, a cooling device, and a thermometer, and heated to an internal temperature of 80 ° C. with an oil bath. A dropping funnel was charged with 169 g (0.8 mol) of phenyltrichlorosilane, 20 g (0.08 mol) of diphenyldichlorosilane and 15 g (0.12 mol) of dimethyldichlorosilane, and dropped into the flask over 1 hour while stirring. After completion of the dropwise addition, the mixture was further aged by continuing stirring at an internal temperature of 80 ° C. for 1 hour. Subsequently, 54 g (0.5 mol) of trimethylchlorosilane was dropped into the flask over 15 minutes while stirring, and after completion of the dropwise addition, the mixture was further aged at an internal temperature of 80 ° C. for 40 minutes. Water washing operation that removes the separated aqueous layer by cooling to room temperature and removing the separated aqueous layer, followed by mixing with 10% aqueous sodium sulfate solution and stirring for 10 minutes, and then standing for 30 minutes. The reaction was stopped by repeating until the toluene layer became neutral. An ester adapter was attached, and the toluene layer containing the organopolysiloxane was heated and refluxed to remove water from the toluene layer. After the internal temperature reached 110 ° C., the mixture was further continued for 1 hour, and then cooled to room temperature. The obtained organopolysiloxane solution was filtered to remove insolubles, and then toluene and low-molecular siloxane were removed by distillation under reduced pressure to obtain 137 g of solid phenyl group-containing organopolysiloxane-2.
The obtained organopolysiloxane-2 contains 27 mol% of M units, 15 mol% of D units and 58 mol% of T units, and the phenyl group content in all organic substituents is 78 wt%, The content was 0% by weight, the hydroxyl group content was 0.9% by weight, the appearance was a colorless transparent solid, and the weight average molecular weight was 3,100. The softening point of this resin was 71 ° C.

Synthesis example 3
A 1 L flask equipped with a stirrer, a cooling device, and a thermometer was charged with 20 g of isopropanol, 200 g of toluene, 226 g (0.8 mol) of phenyltriisopropoxysilane and 35 g (0.2 mol) of dimethyldiisopropoxysilane and stirred. However, 396 g (22 mol) of 0.2N hydrochloric acid was added dropwise at room temperature over 1 hour, and after completion of the dropwise addition, the internal temperature was raised to 90 ° C., and the by-produced isopropanol was distilled off. Further, the mixture was aged by continuing stirring at 90 ° C. for 1 hour. Water washing operation that removes the separated aqueous layer by cooling to room temperature and removing the separated aqueous layer, followed by mixing with 10% aqueous sodium sulfate solution and stirring for 10 minutes, and then standing for 30 minutes. The reaction was stopped by repeating until the toluene layer became neutral. An ester adapter was attached, and the toluene layer containing the organopolysiloxane was heated and refluxed to remove water from the toluene layer. After the internal temperature reached 110 ° C., the mixture was further continued for 1 hour, and then cooled to room temperature. Subsequently, 45 g (0.28 mol) of hexamethyldisilazane was dropped into the flask with stirring over 15 minutes. After completion of the dropping, the internal temperature was raised to 100 ° C., and stirring was continued for 1 hour to ripen, Cooled to room temperature. The obtained organopolysiloxane solution was filtered to remove insolubles, and then toluene and low-molecular siloxane were removed by distillation under reduced pressure to obtain 132 g of a solid phenyl group-containing organopolysiloxane-3.
The obtained organopolysiloxane-3 contains 24 mol% of M units, 15 mol% of D units, and 61 mol% of T units, and the phenyl group content in all organic substituents is 73 wt%, The (isopropoxy group) content was 1.3% by weight, the hydroxyl group content was 0.5% by weight, the appearance was a colorless transparent solid, and the weight average molecular weight was 5,800. The softening point of this resin was 89 ° C.

Synthesis Examples 4-6
In the same preparation method as in Synthesis Example 1, various types of organopolysiloxanes 4 to 6 were obtained by changing the type of organochlorosilane to be used and the amounts (molar ratio) of organochlorosilane, water and toluene.

  The phenyl group content (% by weight) in all organic substituents in each organopolysiloxane obtained in the above synthesis example was calculated by the above formula from the NMR measurement data, and the alkoxy group content (% by weight) in all molecules. ) And the hydroxyl group content (wt%) as Si-OH groups in all molecules according to the Grignard method by reacting a predetermined amount of organopolysiloxane with a methyl Grignard reagent to quantify the methane gas produced. The weight average molecular weight was converted from the GPC measurement data using a calibration curve prepared with a polystyrene standard sample. Table 1 shows the physical property values of organopolysiloxanes 1 to 6 obtained in Synthesis Examples 1 to 6.

(E) Light diffusing agent:
Gantz Pearl GM0449S manufactured by Gantz Kasei
(Acrylic diffusing agent, hereinafter abbreviated as LD)
(F) Optical brightener:
Nippon Kayaku Kayalite OS (hereinafter abbreviated as OS)
(G) UV absorber:
Tinuvin 329 manufactured by Ciba Specialty Chemicals (hereinafter abbreviated as UVA)

(Preparation of polycarbonate resin composition)
Each of the above-mentioned various raw materials was put into a tumbler at the blending ratios shown in Tables 3 to 6, and after dry mixing for 10 minutes, a twin-screw extruder (TEX30α manufactured by Nippon Steel Co., Ltd. (L / D = 42, Φ = 30 mm) )) And kneading at a melting temperature of 260 ° C. to obtain pellets.

(Creation of optical test piece)
Using the obtained pellets, a plate-like test piece having a width of 50 mm, a length of 90 mm and a thickness of 1.5 mm was prepared with an injection molding machine (J100EII-P, manufactured by Nippon Steel).

(Test piece evaluation method)
1. Total light transmittance:
Using the obtained test piece, the total light transmittance was measured in accordance with JIS K7361. At a thickness of 1.5 mm, 50% or more was accepted.
2. Haze:
Using the obtained test piece, haze was measured according to JIS K7136. At a thickness of 1.5 mm, 80% or more was accepted.
3. Flame retardance:
(Creation of test piece for UL94 combustion test)
Using the obtained pellets, a strip-shaped test piece having a width of 13 mm, a length of 127 mm, and a thickness of 1.5 mm was prepared with an injection molding machine (J100EII-P, manufactured by Nippon Steel).
The test piece is allowed to stand for 48 hours in a thermostatic chamber at a temperature of 23 ° C. and a humidity of 50%, and is flame retardant in accordance with UL94 test (flammability test of plastic materials for equipment parts) established by Underwriters Laboratories. Sexuality was evaluated. The criteria are shown in Table 2.

The after-flame time shown above is the length of time that the test piece continues to burn with flame after the ignition source is moved away. The ignition of cotton by drip is about 300 mm below the lower end of the test piece. It is determined by whether a certain marking cotton is ignited by a drip from the specimen.

Examples 1 to 6 are cases where organopolysiloxanes 1 to 6 were used and the metal salt, PTFE, organosiloxane, and light diffusing agent were added in amounts described in the specification. Haze and flame retardancy showed good results.
Examples 7 to 14 are cases in which the metal salt, PTFE, organosiloxane, and light diffusing agent were changed within the range of addition amounts described in the specification, but all had good results in transmittance, haze, and flame retardancy. showed that.
Examples 15 to 17 are cases where a metal salt, PTFE, organosiloxane, and a light diffusing agent were added as described in the specification, and OS and UVA were added according to the added amounts described in the specification. The rate, haze and flame retardancy showed good results.

When metal salts (Comparative Examples 1 and 2), PTFE (Comparative Examples 3 and 4) and organopolysiloxane (Comparative Examples 5 and 6) were used beyond the range of addition amounts described in the specification, The light transmittance and haze showed good results, but both were inferior in flame retardancy.
Comparative Example 7 was a case where the amount of the light diffusing agent used was less than the amount described in the specification, and the total light transmittance and flame retardancy showed good results, but the haze was inferior.
In Comparative Example 8, the amount of the light diffusing agent used was larger than the amount described in the specification, and the haze and flame retardancy were good, but the total light transmittance was inferior.
Comparative Examples 9 to 11 are cases where metal salt, PTFE, organosiloxane, and light diffusing agent were added as described in the specification, and OS and / or UVA was added in excess of the amount described in the specification. The total light transmittance and haze showed good results, respectively, but both were inferior in flame retardancy.

Claims (5)

A lighting cover made of polycarbonate resin,
(1) The lighting cover is formed by molding a polycarbonate resin composition containing the following components (A) to (E), and (2) UL94 test method (for plastic materials for equipment parts) Based on a flammability test), when a combustion test was performed using a test piece having a thickness of 1.5 mm formed by molding the resin composition, it had a V-0 rating, and (3) based on JIS K7361, The total light transmittance measured using a test piece having a thickness of 1.5 mm formed by molding the resin composition is 50% or more, and the haze is 80% or more. A lighting cover made of polycarbonate resin, wherein the lighting cover is a lighting cover for a lighting fixture using an LED light source.
(A) Polycarbonate resin 100 parts by weight (B) Organometallic salt compound which is a metal salt of aromatic sulfonamide, a metal salt of aromatic sulfonic acid or a metal salt of perfluoroalkanesulfonic acid 0.01 to 0.5 part by weight (C) Fiber-forming fluorine-containing polymer 0.05 to 1 part by weight (D) R ¹ R ² R ³ SiO _1/2 (wherein R ¹ , R ² and R ³ are the same or different, carbon A monovalent hydrocarbon group which may be substituted of 1 to 6). The organopolysiloxane containing a siloxane unit represented by formula (1), which is essentially a phenyl group as a substituent bonded to a silicon atom. Each containing 2 wt% or less of an alkoxy group and / or a hydroxyl group, and having a weight average molecular weight of 2,000 or more Part (E) Light diffusing agent 0.01-5 parts by weight   The polycarbonate resin lighting cover according to claim 1, wherein the polycarbonate resin composition further comprises (F) a fluorescent brightening agent up to 0.3 parts by weight per 100 parts by weight of the (A) polycarbonate resin.   The polycarbonate resin lighting cover according to claim 1 or 2, wherein the polycarbonate resin composition further comprises (G) an ultraviolet absorber up to 1 part by weight per 100 parts by weight of the polycarbonate resin (A). .   2. The polycarbonate resin lighting cover according to claim 1, wherein the (D) fiber-forming fluorine-containing polymer is polytetrafluoroethylene.   The polycarbonate resin lighting cover according to claim 1, wherein the (E) light diffusing agent is an acrylic and / or silicone light diffusing agent.