JP2012133891A - Cover for guide light - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cover for a guide light, which, since it does not use a conventional flame retardant containing bromine or chlorine, has no fear of generating gas containing bromine or chlorine due to the flame retardant during burning, and that, is excellent for environment since it does not use any phosphorus-based flame retardant, and further, since it has flame resistant properties passing the UL94-5V test in a thin mold product without damaging various kinds of performance that polycarbonate resin has, is suitable for a cover for a guide light or the like requiring light-masking performance and high flame resistance properties, and has a high practical utility value.SOLUTION: The cover for a guide light is made by molding polycarbonate resin (A), a silicone compound (B) with a main chain of a branch structure and an organic functional group made of an aromatic group or an aromatic group as well as a hydrocarbon group (excluding an aromatic group), a metal salt (C) of an aromatic sulfur compound, a metal salt (D) of perfluoroalkane sulfone acid, a fiber-forming type fluorine-containing polymer (E), and titanium dioxide (F).

Description

  TECHNICAL FIELD The present invention relates to a guide lamp cover made of polycarbonate resin having high light shielding properties and excellent flame resistance. Since the resin composition according to the present invention is excellent in light-shielding properties, light leakage from the side surface can be prevented and the front display panel can be kept at high luminance. Furthermore, it maintains high flame resistance equivalent to UL94 test 5V that satisfies safety requirements, and also has excellent fluidity, impact resistance, and appearance during molding, so it can be used suitably for guide light covers. .

  In public facilities and means of transportation, guide lights are widely installed in hallways and stairs to display emergency evacuation destinations and escape destinations in the event of an emergency such as a fire. Conventionally, metals such as aluminum have been used for the guide light cover. However, in recent years, replacement with resin has been progressing for the purpose of reducing the weight of the material or reducing the cost.

  Polycarbonate resin is a thermoplastic resin excellent in transparency and impact resistance, and is widely used in fields such as electricity, electronics, machinery, and automobiles. In illumination cover applications, polycarbonate resins are attracting attention from the standpoint of heat resistance while taking advantage of the superior performance of the resins. Furthermore, the guide light cover is also required to have a high light-shielding property and a high degree of flame resistance in order to prevent light leakage.

In order to impart high light shielding properties to the polycarbonate resin, it is necessary to blend a large amount of titanium oxide. However, when a large amount of titanium oxide is blended, a reduction in flame retardancy and a reduction in mechanical strength are inevitable. In the flame retarding of polycarbonate resin, a method of blending a halogen compound or a phosphorus compound as a flame retardant has been conventionally employed (see Patent Document 1). Among these, particularly halogen compounds such as bromine and chlorine are desired to use flame retardants that do not contain them from the viewpoint of the environment, and proposals for flame retardants using silicone flame retardants have been made. (See Patent Document 2)
Patent Document 3 proposes a flame retardant polycarbonate resin composition containing titanium oxide, but does not satisfy the required flame retardant performance equivalent to UL94 test 5V, and has even better flame retardancy. There is a need for the development of materials having

JP-A-10-001600 JP 2003-155405 A Special table 2010-514890 gazette

  As described above, the polycarbonate resin used for the guide light cover has recently been required to have further safety and flame resistance equivalent to UL94 test 5V. In addition to this performance, the front display board In order to prevent a decrease in luminance, a high light shielding property is required for the purpose of preventing light leakage from the side surface.

  As a result of diligent research in view of such problems, the present inventors have found that an aromatic sulfur compound and perfluorocarbon are added to a polycarbonate resin having a light-blocking property made flame-retardant with a specific silicone compound and a fiber-forming fluorine-containing polymer. Surprisingly, it has been found that the flame resistance is remarkably improved by using a metal salt of alkanesulfonic acid in combination, and the present invention has been completed.

  That is, the present invention relates to 100 parts by weight of the polycarbonate resin (A), the main chain is a branched structure, and the organic functional group contained is an aromatic group, or an aromatic group and a hydrocarbon group (excluding an aromatic group). 0.1 to 1.5 parts by weight of a silicone compound (B), 0.01 to 0.5 part by weight of a metal salt of an aromatic sulfur compound (C), and a metal salt of a perfluoroalkanesulfonic acid (D) 0 .01-0.5 part by weight, induction formed by molding a resin composition comprising a fiber-forming fluoropolymer (E) 0.1-1.0 part by weight and titanium dioxide (F) 3-25 part by weight A lamp cover is provided.

  Since the cover for a guide light of the present invention does not use a conventional flame retardant containing bromine or chlorine, there is no concern about the generation of a gas containing bromine or chlorine due to the flame retardant during combustion, and a phosphorus-based difficulty. It is environmentally friendly because it does not use any flame retardant. Furthermore, it has a flame resistance equivalent to UL94 test 5V in thin molded products without impairing the various excellent performances of polycarbonate resin, so it is a guide light that requires high light-shielding properties, heat resistance, and high flame resistance. It is suitable for a cover and has a very high practical utility value.

  The polycarbonate resin (A) used in the present invention is obtained by a phosgene method in which various dihydroxydiaryl compounds and phosgene are reacted, or a transesterification method in which a dihydroxydiaryl 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 singly or as a mixture of two or more. However, it is preferable not to be substituted with a halogen from the viewpoint of preventing discharge of the gas containing the halogen, which is a concern during combustion, into the environment. 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 (A) is usually 10,000 to 100,000, preferably 12,000 to 35,000, and more preferably 15,000 to 28,000. In producing such an aromatic polycarbonate resin, a molecular weight regulator, a catalyst, and the like can be used as necessary.

The viscosity average molecular weight is determined by measuring the specific viscosity (ηsp) at a temperature of 20 ° C. using a Cannon-Fenske type viscosity tube using methylene chloride as a solvent and using a Cannon-Fenske type viscosity tube. η] was obtained and calculated from the following SCHNELL equation.
[Η] = 1.23 × 10 ⁻⁴ M ^0.83

The silicone compound (B) used in the present invention has a branched main structure and an organic functional group consisting of an aromatic group, or an aromatic group and a hydrocarbon group (excluding an aromatic group). Is represented by the following general formula (1).
General formula (1)

Here, R ₁ , R ₂ and R ₃ represent main chain organic functional groups, and X represents a terminal functional group.
That is, it has a T unit (RSiO _1.5 ) and / or a Q unit (SiO _2.0 ) as a branch unit. These preferably contains more than 20 mol% of the total siloxane units _{(R 3~0 SiO 2~0.5).} (R represents an organic functional group.) The silicone compound (B) preferably contains 20 mol% or more of aromatic groups among the organic functional groups contained.

  The aromatic group contained is phenyl, biphenyl, naphthalene or a derivative thereof, but a phenyl group can be preferably used.

  Of the organic functional groups in the silicone compound (B) attached to the main chain or branched side chain, the organic group other than the aromatic group is preferably a hydrocarbon group having 4 or less carbon atoms, and preferably a methyl group. Can be used. Further, the terminal group is preferably one kind selected from methyl group, phenyl group and hydroxyl group, or a mixture of these two kinds to three kinds.

  The average molecular weight (weight average) of the silicone compound (B) is preferably 3000 to 500000, and more preferably 5000 to 270000.

  The compounding quantity of a silicone compound (B) is 0.1-1.5 weight part per 100 weight part of polycarbonate resin (A). If the blending amount is out of this range, any flame retardant effect cannot be obtained. Preferably it is 0.1-1.0 weight part, More preferably, it is the range of 0.2-0.9 weight part.

  Examples of the metal salt (C) of the aromatic sulfur compound used in the present invention include a metal salt of alkanesulfonic acid, and preferably 4-methyl-N- (4-methylphenyl) sulfonyl-benzenesulfone. Amide potassium salt, potassium diphenylsulfone-3-sulfonate, potassium diphenylsulfone-3-3′-disulfonate, sodium paratoluenesulfonate, and the like can be used.

  The compounding quantity of the metal salt (C) of an aromatic sulfur compound is 0.01-0.5 weight part per 100 weight part of polycarbonate resin (A). If the blending amount is out of this range, any flame retardant effect having sufficient flame resistance cannot be obtained, which is not preferable. Preferably it is 0.02-0.3 weight part, More preferably, it is the range of 0.02-0.2 weight part.

  Examples of the metal salt (D) of perfluoroalkanesulfonic acid used in the present invention include alkali metal salts or alkaline earth metal salts of perfluoroalkanesulfonic acid. Especially, the potassium salt of perfluorobutanesulfonic acid can be used conveniently.

  The compounding amount of the metal salt (D) of perfluoroalkanesulfonic acid is 0.01 to 0.5 parts by weight per 100 parts by weight of the polycarbonate resin (A). If the blending amount is less than 0.01 parts by weight, the flame resistance and flame retardancy are lowered, which is not preferable. On the other hand, when the amount exceeds 0.5 parts by weight, there is a problem in that flame resistance and flame retardancy cannot be obtained, or surface appearance deteriorates. Preferably it is 0.05-0.3 weight part, More preferably, it is the range of 0.1-0.2 weight part.

  The fiber-forming fluorine-containing polymer (E) used in the present invention is preferably one that forms a fibril-like structure in the polycarbonate resin (A). For example, polytetrafluoroethylene, a tetrafluoroethylene copolymer (For example, tetrafluoroethylene / hexafluoropropylene copolymer, etc.), partially fluorinated polymers as shown in US Pat. No. 4,379,910, polycarbonates produced from fluorinated diphenols, and the like. In particular, polytetrafluoroethylene having a molecular weight of 1,000,000 or more and a fibril-forming ability having a secondary particle diameter of 100 μm or more is preferably used.

  The compounding amount of the fiber-forming fluoropolymer (F) is 0.1 to 1.0 part by weight per 100 parts by weight of the polycarbonate resin. If the blending amount is less than 0.1 part by weight, the anti-dripping property is inferior, and if it exceeds 1.0 part by weight, the surface appearance and granulation property are deteriorated, which is not preferable. Preferably it is 0.2-0.6 weight part, More preferably, it is the range of 0.3-0.45 weight part.

  The titanium dioxide (F) used in the present invention may be produced by either the chlorine method or the sulfuric acid method, and the crystal form may be either a rutile type or an anatase type. Further, the particle diameter of titanium dioxide is preferably about 0.1 to 0.5 μm.

Examples of commercially available titanium dioxide include DuPont R902, Resino Color Kogyo DCF 17007, Kronos 2230, Ishihara Sangyo Typek PF740, and the like.

  The compounding quantity of titanium dioxide (F) is 3-25 weight part per 100 weight part of polycarbonate resin (A). If the blending amount is less than 3 parts by weight, the light reflectivity is inferior, and if it exceeds 25 parts by weight, the appearance and mechanical strength (impact strength) are deteriorated. A more preferable blending amount is in the range of 5 to 15 parts by weight.

  The blending method of the various blending components (A), (B), (C), (D), (E) and (F) of the present invention is not particularly limited, and any mixer, for example, a tumbler, ribbon blender, high speed These can be mixed by a mixer or the like, and can be easily melt-kneaded with a normal single-screw or twin-screw extruder. Moreover, there is no restriction | limiting in particular also about these compounding orders.

  Furthermore, various heat stabilizers, antioxidants, fillers, mold release agents, antistatic agents, softeners, spreading agents (epoxy soybean oil) are added to the resin composition of the present invention within a range not impairing the effects of the present invention. , Liquid paraffin, etc.), additives such as dyes and pigments, and other polymers may be blended.

  As a method for manufacturing the guide light cover of the present invention, methods such as injection molding, injection compression molding and injection press molding can be employed.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples. Unless otherwise specified, “%” and “parts” in the examples are based on weight standards.

The raw materials used are as follows.
Polycarbonate resin:
Polycarbonate resin synthesized from bisphenol A and phosgene (Sumitomo Dow Caliber 200-20, viscosity average molecular weight: 19000
(Hereinafter abbreviated as PC)

Silicone compound (hereinafter abbreviated as silicone compound):
The silicone compound was produced according to a general production method. That is, a silicone compound partially condensed by dissolving an appropriate amount of diorganodichlorosilane, monoorganotrichlorosilane and tetrachlorosilane, or a partially hydrolyzed condensate thereof in an organic solvent, adding water and hydrolyzing it. Then, triorganochlorosilane was added and reacted to terminate the polymerization, and then the solvent was separated by distillation or the like. The structural characteristics of the silicone compound synthesized by the above method are as follows:
・ D / T / Q unit ratio of main chain structure: 40/60/0 (molar ratio)
-Ratio of phenyl group in all organic functional groups (*): 60 mol%
-Terminal group: methyl group only-Weight average molecular weight (**): 15000
*: The phenyl group is first contained in the T unit in the silicone containing the T unit, and the remaining D group is contained in the D unit. When the phenyl group is attached to the D unit, the one attached is preferential, and when the phenyl group remains, two are attached. Except for the terminal group, the organic functional group is a methyl group except for the phenyl group.
**: Weight average molecular weight is two significant digits.

Metal salts of aromatic sulfur compounds:
Sodium paratoluenesulfonate (hereinafter abbreviated as metal salt 1)
Metal salt of perfluoroalkanesulfonic acid:
Perfluorobutanesulfonic acid potassium salt (hereinafter abbreviated as metal salt 2)
Fiber-forming fluorine-containing polymer:
Daikin polyflon FA500
(Polytetrafluoroethylene, hereinafter abbreviated as PTFE)
titanium dioxide:
2230 made by Kronos
(Kronos 2230, hereinafter abbreviated as TiO2)

A method for measuring various evaluation items in the present invention will be described.
(Preparation of resin composition pellets)
Various blending components were mixed with a tumbler at the blending components and blending ratios shown in Tables 2 to 5, and melt-kneaded at a cylinder temperature of 280 degrees using a 37 mm diameter twin screw extruder (KTX37 manufactured by Kobe Steel). Various pellets were obtained.

(Evaluation of flame resistance)
The obtained pellets were dried at 125 ° C. for 4 hours, and then tested using an injection molding machine (J100C-5 manufactured by Nippon Steel Works) under the conditions of 240 ° C. and injection pressure 1600 kg / cm ² (2. 0 mm). This specimen is left in a constant temperature room at 23 ° C. and 50% humidity for 168 hours, and evaluated for flame resistance according to UL94 test (flammability test of plastic materials for equipment parts) established by Under Rutters Laboratory. went.
The evaluation criteria of UL94-5V are shown in Table 1. When the standard was cleared, it was determined to pass (O), and the others were determined to be unacceptable (X).

  Cotton ignition by drip is determined by whether or not the marking cotton, which is 300 mm below the lower end of the test piece, is ignited by a drip from the test piece.

(Appearance evaluation)
After drying the obtained various pellets at 125 ° C. for 4 hours, using an injection molding machine (Japan Steel Works J100C-5) at 300 ° C. and an injection pressure of 1600 kg / cm ² , a test piece for optical measurement (width 50 mm, 40 mm long and 2 mm thick). The occurrence of sink marks and unevenness was visually determined on the obtained test piece. Those without sink / unevenness were accepted (O), and those with sink / unevenness were rejected (X).

(Light shielding)
The obtained pellets were dried at 125 ° C. for 4 hours and then used in an injection molding machine (Japan Steel Works J100C-5) under conditions of 300 ° C. and injection pressure of 1600 kg / cm ² in three stages of length 90 mm and width 40 mm. A plate (thickness 3, 2, 1 mm) test piece was prepared, and the transmitted illuminance of a 1 mm thick portion was measured. As a light source, an xenon light source (ILV) manufactured by Olympus was used, and the test piece was irradiated with light having an illuminance of 30000 lux. A Minolta digital illuminometer T-1H was used for measurement of transmitted illuminance.
As the determination of the light shielding property, a transmittance of less than 400 lux was accepted (◯), and a transmittance of 400 lux or more was rejected (x).

  The evaluation results are shown in Tables 2 to 5, respectively.

  As shown in Tables 2 and 3, when all the constituent requirements of the present invention were satisfied (Examples 1 to 10), the evaluation items had sufficient performance.

On the other hand, as shown in Tables 4 and 5, when the configuration of the present invention was not satisfied, each case had some drawbacks.
The comparative example 1 was inferior in flame resistance in the case where the compounding quantity of a silicone compound was less than a regulation amount.
Comparative Example 2 was a case where the compounding amount of the silicone compound was larger than the specified amount, and was inferior in flame resistance and appearance.
The comparative example 3 was a case where the compounding quantity of the metal salt 1 was less than a regulation amount, and was inferior in flame resistance.
In Comparative Example 4, the compounding amount of the metal salt 1 was larger than the specified amount, and the flame resistance and the appearance were inferior.
The comparative example 5 was inferior in flame resistance in the case where the compounding amount of the metal salt 2 was less than the specified amount.
The comparative example 6 was a case where the compounding quantity of the metal salt 2 was larger than a prescribed quantity, and was inferior in flame resistance and external appearance.
In Comparative Example 7, the amount of PTFE was less than the specified amount, and the flame resistance was poor.
In Comparative Example 8, the amount of PTFE was larger than the specified amount, and the flame resistance and appearance were inferior.
Comparative Example 9 was a case where the blending amount of titanium oxide was less than the specified amount, and was inferior in light shielding properties.
Comparative Example 10 was a case where the blending amount of titanium oxide was larger than the specified amount, and was inferior in flame retardancy and appearance.

Claims (5)

  100 parts by weight of a polycarbonate resin (A), a silicone compound having a branched main chain structure and an organic functional group containing an aromatic group, or an aromatic group and a hydrocarbon group (excluding an aromatic group) ( B) 0.1 to 1.5 parts by weight, metal salt of aromatic sulfur compound (C) 0.01 to 0.5 part by weight, metal salt of perfluoroalkanesulfonic acid (D) 0.01 to 0.5 A guide lamp cover formed by molding a resin composition comprising parts by weight, 0.1 to 1.0 part by weight of a fiber-forming fluoropolymer (E) and 3 to 25 parts by weight of titanium dioxide (F).   The amount of the silicone compound (B) consisting of a branched structure and an organic functional group containing an aromatic group or an aromatic group and a hydrocarbon group (excluding an aromatic group) is a polycarbonate resin. (A) It is 0.1-1.0 weight part per 100 weight part, The cover for guide lights of Claim 1 characterized by the above-mentioned.   The compounding amount of the metal salt (C) of the aromatic sulfur compound is 0.02 to 0.2 parts by weight, and the compounding amount of the metal salt (D) of perfluoroalkanesulfonic acid is 0.1 to 0.2 parts by weight, The guide light cover according to claim 1, wherein:   The cover for a guide lamp according to claim 1, wherein the fiber-forming fluorine-containing polymer (F) is polytetrafluoroethylene.   The guide lamp cover according to claim 1, wherein the amount of the fiber-forming fluoropolymer (F) is 0.3 to 0.45 parts by weight per 100 parts by weight of the polycarbonate resin (A). .