JPH10237278A - Thermoplastic resin composition and molded item produced therefrom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive seamless belt excellent in flex resistance and a resin compsn. suitable for producing the same. SOLUTION: This compsn., having flame retardance and electrical conductivity, mainly comprises 100 pts.wt. thermoplastic polyester or polycarbonate resin (A), at least 2 pts.wt. thermoplastic polyester elastomer (B), at least 3 pts.wt. conductive filler (C), and at least 3 pts.wt. bromine-contg. flame retardant (D). Pref. the wt. ratio of the sum of ingredients C and D to the sum of ingredients A and D is 0.2-0.5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin composition having excellent flame retardancy and conductivity, and a film-like article comprising the same. The film-shaped article according to the present invention is, for example, an electrophotographic copying machine as a seamless belt,
It is suitably used for laser beam printers, facsimile machines and the like.

[0002]

2. Description of the Related Art Parts made of a conductive thermoplastic resin composition have been widely used in various electronic and office equipment. For example, in certain electrophotographic copying machines, a seamless belt made of a conductive thermoplastic resin composition is used. For example, Japanese Patent Application Laid-Open No. 3-89357 discloses that a mixture of a conductive resin and a thermoplastic resin such as polycarbonate or fluorocarbon resin is extruded into a thin cylindrical shape using an annular die, and the cylindrical film is cut into a ring. To make a seamless belt.

[0003] However, a seamless belt made of a mixture of polycarbonate and carbon black has poor bending resistance (hereinafter sometimes referred to as folding resistance), and the seamless belt is cracked and damaged during use. There is a drawback that it is easy to do. Further, when a flame retardant is added to impart flame retardancy, the folding resistance is more rapidly deteriorated. In addition, a seamless belt made of a fluorocarbon resin mixed with carbon black has high folding resistance and excellent flame retardancy, but its volume resistivity increases with time when a voltage is continuously applied. There is a problem of lowering. The present invention seeks to provide a conductive seamless belt which has high folding resistance, is excellent in flame retardancy, and whose volume resistivity does not decrease over time by voltage application, and a thermoplastic resin composition which provides such a seamless belt. Is what you do.

[0004]

Means for Solving the Problems The thermoplastic resin composition according to the present invention is characterized by mainly comprising the following components (a) to (d). (A) 100 parts by weight of thermoplastic resin selected from polyester and polycarbonate (b) 2 parts by weight or more of polyester-based thermoplastic elastomer (c) 3 parts by weight or more of conductive filler (d) 3 parts by weight or more of bromine-containing flame retardant The seamless belt according to the present invention can be manufactured by extruding the thermoplastic resin composition into a thin cylindrical shape using an annular die by a conventional method, and then cutting the obtained cylindrical film into a ring shape. .

[0005]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in more detail. The thermoplastic resin composition according to the present invention comprises a thermoplastic resin selected from polyester and polycarbonate,
It contains four components, a polyester-based thermoplastic elastomer, a conductive filler and a bromine-containing flame retardant, as essential components. Explaining each of these components, polyesters include aliphatic diols such as ethylene glycol, diethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, hexamethylene glycol, and neopentyl glycol. And cycloaliphatic or aromatic diols such as cyclohexanedimethanol and bisphenol A with aliphatic dicarboxylic acids such as adipic acid and aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid and 2,6-naphthalenedicarboxylic acid. What is condensed is used. Preferably, an aromatic dicarboxylic acid, particularly one containing terephthalic acid as a main carboxylic acid component, for example, polyethylene terephthalate or polybutylene terephthalate is used. Among them, it is preferable to use polybutylene terephthalate. The polybutylene terephthalate has a weight average molecular weight of 10,000 to 500,000, particularly 50,000.
It is preferable to use those having 0 to 150,000. The melt flow rate is preferably less than 15 g / 10 minutes. It is preferable to use a polycarbonate derived from an aromatic diol such as bisphenol A as the polycarbonate. The weight average molecular weight of the polycarbonate is 5,000
~ 100,000, especially 10,000-50,000 are preferred.

[0006] The mechanical properties of these polyesters and polycarbonates are the basis of the mechanical properties of the resin composition according to the present invention, and are selected according to the desired properties of the resin composition. For example, a seamless belt is generally required to have a low elongation. Therefore, when the resin composition according to the present invention is applied to a seamless belt, the polyester and the polycarbonate have a Young's modulus of 15,000.
0 kgf / cm ² or more, especially 20,000 kgf / cm
^It is preferable to use ^two or more.

[0007] The polyester-based thermoplastic elastomer is an elastomer containing a polyester portion, and has an effect of imparting folding resistance to a molded article made of a resin composition and inhibiting the occurrence of cracks. As a polyester-based thermoplastic elastomer, Young's modulus is 10,000 kg
f / cm ² or less, especially 100 to 5,000 kgf / cm
^{Use two} . The Young's modulus of the resin composition according to the present invention basically depends on the Young's modulus of the above-described polyester or polycarbonate, the Young's modulus of the polyester-based thermoplastic elastomer, and the amount thereof.

As the polyester-based thermoplastic elastomer, usually, an aromatic polyester is used as a hard component,
Aromatic polyester-aliphatic polyester block copolymer containing aliphatic polyether as a soft component, aromatic polyester-aliphatic polyether block copolymer, or aromatic polyester as a hard component and an aliphatic polyester as a soft component Coalescing is used.

The diol component constituting the aromatic polyester portion of the aromatic polyester-aliphatic polyether block copolymer is usually the aliphatic or alicyclic diol exemplified as the diol component of the polyester described above.
Preferably, ethylene glycol or 1,4-butanediol is mainly used. As the aromatic dicarboxylic acid component, those exemplified as the aromatic dicarboxylic acid component of the polyester described above, preferably terephthalic acid or 2,6-naphthalenedicarboxylic acid are mainly used.

Examples of the aliphatic polyether include polyethylene glycol, poly (1,2-propylene) ether glycol, poly (1,3-propylene) ether glycol, polytetramethylene ether glycol, polyhexamethylene ether glycol, ethylene oxide and propylene. A random or block copolymer of oxide, a random or block copolymer of ethylene oxide and tetrahydrofuran, or the like is used. Among them, it is preferable to use polytetramethylene ether glycol. The weight average molecular weight of the aliphatic polyether is 400 to
Preferably it is 6,000, especially 500-4,000. These aliphatic polyether components are aromatic polyester-aliphatic polyether block copolymer 5 to 5.
It preferably accounts for 95% by weight, especially 10 to 85% by weight.

When the above-mentioned diol, aromatic dicarboxylic acid and aliphatic polyether are polycondensed by a conventional method, a thermoplastic elastomer comprising an aromatic polyester-aliphatic polyether block copolymer is obtained. In the polycondensation, the aromatic dicarboxylic acid may be used as a methyl ester or the like, and the diol or the aromatic dicarboxylic acid may be used as a modifying component of an aromatic polyester such as a triol or adipic acid or another aliphatic carboxylic acid. Commonly used components may be used in small amounts.

The aromatic polyester-aliphatic polyester block copolymer is obtained by preparing an aromatic polyester-aliphatic polyether block copolymer by using an aliphatic or alicyclic dicarboxylic acid in place of the aliphatic polyether in the production of the aromatic polyester-aliphatic polyether block copolymer. It is obtained using a polyester with an aliphatic diol or an aliphatic polyester derived from an aliphatic monohydroxycarboxylic acid or a corresponding lactone.
For example, 1,4-cyclohexanedicarboxylic acid, 1,2
-Cyclohexanedicarboxylic acid, dicyclohexyl-
An alicyclic dicarboxylic acid such as 4,4'-dicarboxylic acid or an aliphatic dicarboxylic acid such as succinic acid, oxalic acid, adipic acid, sebacic acid and ethylene glycol;
Polyesters obtained by polycondensation of diols such as propylene glycol and pentamethylene glycol, and poly-ε-caprolactone obtained by ring-opening polymerization of ε-caprolactone are used.

The weight average molecular weight of these aliphatic polyesters is preferably from 400 to 6,000, particularly preferably from 500 to 4,000, and their ratio to the aromatic polyester-aliphatic polyester is from 5 to 95% by weight, in particular 10
Preferably it is 85% by weight. The polyester-based thermoplastic elastomer is used in an amount of 2 parts by weight or more, preferably 5 parts by weight or more based on 100 parts by weight of a thermoplastic resin selected from polyester and polycarbonate. However, if the amount is too large, the physical properties of the base thermoplastic resin are impaired, so the amount should be at most 200 parts by weight, usually 120 parts by weight or less. For example, when the resin composition according to the present invention is applied to a seamless belt, it is preferable to use 7 to 60 parts by weight of a polyester-based thermoplastic elastomer with respect to 100 parts by weight of a thermoplastic resin in view of overall physical properties.

As the conductive filler used in the resin composition according to the present invention, it is preferable to use carbon black. The carbon black may be any commercially available carbon black, such as acetylene black, fanace black, and channel black, but it is preferable to use acetylene black. The carbon black has a primary particle diameter of 10 to 100 nm and a specific surface area of 10 to 200 m ² /
g, pH 6-11 are preferred.

Examples of the conductive filler include not only carbon black but also other commonly used carbon-based conductive fillers such as graphite, carbon fiber, activated carbon and charcoal, and metal-based conductive fillers and metal oxide-based conductive fillers. Conductive fillers can also be used. Examples of the metal-based conductive filler include powdery materials such as silver, copper, nickel, and zinc, flakes such as aluminum, silver, and nickel, and fibrous materials such as iron, copper, and stainless steel. As the metal oxide-based conductive filler, zinc oxide, tin oxide, indium oxide, titanium oxide, and the like are used. In addition, among metal oxide-based conductive fillers, in the case where extra electrons are generated due to the presence of lattice defects to exhibit conductivity, a dopant is added to promote formation of vacancies, thereby increasing conductivity. You may use what was made. For example, aluminum is used as zinc oxide, antimony is used as tin oxide, tin is used as indium oxide, and tin is used as indium oxide. In the case of titanium oxide,
Titanium oxide coated with conductive tin oxide can also be used. These conductive fillers preferably have a weight average particle diameter of 0.001 to 10 μm, particularly preferably 0.01 to 1 μm. The specific surface area by the BET method is 1 to 10
0 m ² / g, is preferably in particular 1~80m ² / g, particle's resistance of 100 kg / cm ² of the pressure ^{1~1 × 10 8 Ω · cm,} 10 5 Ω · especially 1 to 1 × cm
It is preferred that

The conductive filler is used in an amount of 3 parts by weight or more, preferably 5 parts by weight or more, based on 100 parts by weight of a thermoplastic resin selected from polyester and polycarbonate. However, if the amount of the conductive filler used is too large, the mechanical properties of the obtained resin composition are greatly reduced, so that the amount used is 100 parts by weight or less based on 100 parts by weight of the thermoplastic resin, preferably 50 parts by weight or less. Should be.

As the bromine-containing flame retardant, an appropriate one may be selected from commercially available products. Usually, it is preferable to use bromine having a bromine content of 30% by weight or more, especially 50% by weight or more. Also, the molecular weight is generally 300 to 5
The one of about 000 is used. Oligomer having a molecular weight of 1,000 or more is preferable because bleeding from the resin composition hardly occurs. As the bromine-containing flame retardant, for example, tetrabromotoluene, tetrabromobisphenol A, oligo or polycarbonate derived therefrom, brominated phenylallyl ether or its oligomer or polymer, brominated polystyrene, copolymerization of brominated bisphenol A with epichlorohydrin An oligomer or a polymer is used. The bromine-containing flame retardant is used in an amount of 3 parts by weight or more, preferably 10 to 50 parts by weight, based on 100 parts by weight of a thermoplastic resin selected from polyester and polycarbonate.
If the amount is too large, the mechanical properties of the resin composition will decrease.

In the resin composition according to the present invention, when the thermoplastic resin and the polyester-based thermoplastic elastomer are used as the resin component, the conductive filler and the bromine-containing flame retardant are non-resin components, and the ratio of the non-resin component is generally low. The higher the value, the lower the mechanical properties of the resin composition. So usually,
Each component is preferably blended so that the ratio of the total weight of the conductive filler and the bromine-containing flame retardant to the total weight of the thermoplastic resin and the polyester-based thermoplastic elastomer is 0.2 to 0.5.

The resin composition according to the present invention basically comprises the above-mentioned four components, but if desired, other components can be used in combination. For example, when a small amount of a flame retardant other than a bromine-containing flame retardant is used in combination, higher flame retardancy can be imparted. Examples of such a flame retardant include antimony compounds such as antimony trioxide and antimony pentoxide, phosphate esters such as triphenyl phosphate and tricresyl phosphate, phosphite esters such as triphenyl phosphite, and microencapsulation. Red phosphorus such as red phosphorus, a sulfonate such as sodium o-dichlorobenzenesulfonate, a silicon-based flame retardant auxiliary, and the like are used.

In addition to the flame retardants, other thermoplastic resins and thermoplastic elastomers, antioxidants such as phenolic, sulfuric, and phosphorous, lubricants, pigments, ultraviolet absorbers, dispersants,
A crosslinking agent, a flow improver and the like can be used in combination, if desired. Also, calcium carbonate, talc, mica, alumina, aluminum hydroxide, magnesium hydroxide, barium sulfate, zinc oxide, zeolite, wollastonite, diatomaceous earth, glass fiber, glass beads, bentonite,
Non-conductive inorganic fillers such as montmorillonite and molybdenum disulfide, organic metal compounds, and organic metal salts can also be used in combination. It is preferable to use these combined components so that the total amount does not exceed 10% by weight of the resin composition.

In order to produce the resin composition according to the present invention from the above-mentioned essential four components and optionally other components, a single-screw extruder, a twin-screw extruder, a multi-screw extruder, a Banbury mixer, a roll, The components may be supplied to a conventional kneader such as a Brabender, a plastograph, or a kneader and mixed. Usually, it is kneaded with a twin-screw extruder to form a pellet-shaped compound. If desired, it can be formed directly without molding into pellets.

One of the preferable uses of the resin composition according to the present invention is a seamless belt as a part for an electrophotographic copying machine, a laser beam printer, a facsimile or the like. The object preferably has the following physical properties. Large number of folds according to JIS P8115; a seamless belt made of a resin composition having a small number of folds is likely to crack and break during use. The number of times of folding endurance is preferably 1000 times or more, and more preferably 2000 times or more. High flame retardancy; it must pass VTM-2 or VTM-1 in UL94 flame retardancy test.
It is more preferable to pass VTM-0. The change in volume resistivity due to voltage application is small; if the volume resistivity changes due to voltage application, the image may be deteriorated. In particular, when the volume resistivity is reduced, the image is significantly deteriorated. In the measurement of the volume resistivity according to JIS K6911, the change in the volume resistivity is the ratio of the measured value one hour after the voltage application to the measured value ten seconds after the voltage application at an applied voltage of 500 V (measured value one hour after application / measured value of 10 1 to 100)
Is preferable, and 1-10 are more preferable.

The resin composition according to the present invention can be used for the production of various molded articles, and the molding method can be various conventional molding methods such as a melt extrusion molding method, an injection molding method, a blow molding method and an inflation molding method. Method can be used. One of the preferable uses of the resin composition according to the present invention is a film, and the film formed into a tubular shape is suitable as a seamless belt of an electrophotographic copying machine. When used for a seamless belt, the thickness of the film is preferably 1 to 1000 μm, particularly preferably 50 to 700 μm. The seamless belt preferably has a high Young's modulus, and usually has a Young's modulus of 8,
2,000 kgf / cm ² or more, especially 12,000 kgf /
cm ² or more are used. Young's modulus is 16,000
If it is 0 kgf / cm ² or more, almost no deformation of the image due to stretching of the belt occurs, but according to the present invention, such a seamless belt having a high Young's modulus can be easily provided. Further, the volume resistivity of the seamless belt varies depending on the use of the seamless belt. When the seamless belt is used as a photosensitive belt, the average volume resistivity is 1 × 10 ³ to 1 ×.
10 ⁵ Ω · cm, adjusting the amount of 1 × 10 ⁷ ~1 × 10 of ¹³ Omega · cm what is used, but the conductive filler according to the present invention when used as an intermediate transfer belt and the conveying transfer belt By doing so, any request can be met. Further, the seamless belt is required to have a uniform volume resistivity without much difference between portions, and a ratio of a maximum value to a minimum value of the volume resistivity is required to be 100 or less, preferably 10 or less. According to the present invention, this requirement can be easily satisfied by sufficiently performing kneading at the time of preparing the resin composition.

[0024]

EXAMPLES The present invention will be described more specifically with reference to the following examples, but the present invention is not limited to the following examples. Each component constituting the resin composition was blended at a weight ratio shown in Table 1, and was melt-kneaded with a twin-screw extruder to obtain pellets. The pellets are supplied to an extruder equipped with an annular die and extruded into a molten tubular shape. The pellets are brought into contact with the outer surface of a cooling mandrel having a diameter of 180 mm which is coaxially arranged with the annular die, and solidified to a thickness of 150 μm. Cylindrical film. This was cut into a circle having a length of 340 mm to obtain a seamless belt. The following items were evaluated for this seamless belt. Table 1 shows the results. Folding resistance: Measured by JIS P8115 Flame retardancy: Measured by UL94-VTM Volume resistivity: Measured by JIS K6911 under the following devices and conditions. Unit Ω · cm Measuring device R8340A (manufactured by Advantest Corporation) Applied voltage 500 V Measurement time 10 seconds and 1 hour Terminal pressing load 4 kgf Young's modulus; Measured according to ISO 527-3. Unit kgf / cm ²

[0025]

[Table 1]

* 1 Polybutylene terephthalate (Novadol 5010 manufactured by Mitsubishi Engineering-Plastics) * 2 Polycarbonate (Iupilon E2000N manufactured by Mitsubishi Engineering-Plastics) * 3 Ethylene-tetrafluoroethylene copolymer (Aflon COP55A Asahi Glass) * 4 Polyester- Polyether elastomer (Perprene P70B, Toyobo Co., Ltd. product) * 5 Carbon black (Denka Black, manufactured by Denki Kagaku Kogyo Co., Ltd.) * 6 Tetrabromobisphenol A carbonate oligomer (FG7500, Teijin Chemicals Ltd. product)

Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08K 5/136 C08K 5/136 C08L 69/00 C08L 69/00

Claims (6)

[Claims] 1. A thermoplastic resin composition having excellent flame retardancy and conductivity, comprising mainly the following components (a) to (d). (A) thermoplastic resin selected from polyester and polycarbonate 100 parts by weight (b) polyester-based thermoplastic elastomer 2 parts by weight or more (c) conductive filler 3 parts by weight or more (d) bromine-containing flame retardant 3 parts by weight or more 2. A thermoplastic resin composition having excellent flame retardancy and conductivity, comprising mainly the following components (a) to (d). (A) 100 parts by weight of a thermoplastic resin selected from polyester and polycarbonate (b) 5 to 120 parts by weight of a polyester thermoplastic elastomer (c) 5 to 50 parts by weight of a conductive filler (d) 10 to 50 parts of a bromine-containing flame retardant Parts by weight 3. The ratio of the total weight of the components (c) and (d) to the total weight of the components (a) and (b) is 0.1.
3. The thermoplastic resin composition according to claim 1, wherein the ratio is from 2 to 0.5. 4. A film comprising the thermoplastic resin composition according to claim 1. 5. A film comprising the thermoplastic resin composition according to claim 1, which has the following physical properties (e) to (g) at the same time. (E) The number of folding endurance according to JIS P8115 is 1000 times or more. (F) VTM-0 in the flame retardancy test according to UL94.
Passes VTM-1 or VTM-2. (G) In the measurement of volume resistivity according to JIS K6911, the ratio of the measured value one hour after applying the voltage to the measured value 10 seconds after applying the voltage at an applied voltage of 500 V is 1 to 10.
0. 6. A seamless belt comprising the film according to claim 5.