JP2003211542A - Heat-shrinkable conductive aromatic polyester resin tube and product of inorganic material covered therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat-shrinkable conductive aromatic polyester tube which is excellent in shrinkage characteristics and opening properties when it is to be put on a component such as a charged roller and which has equal electric characteristics with a usual conductive film layer using a conductive coating solution and further has an excellent chemical resistance on the occasion when the tube is put as a cover on the component and then left for a long time under a high temperature and a high humidity. <P>SOLUTION: The heat-shrinkable conductive aromatic polyester resin tube is formed of a resin composition which contains a conductive filler (B) (component B) of 0.5-50 pts.wt. to 100 pts.wt. of a thermoplastic resin (A) (component A) containing an aromatic polyester resin of 70 wt.% or more. The crystallinity of the aromatic polyester resin in the tube is less than 4%. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-shrinkable conductive aromatic compound formed of a resin composition mainly containing a thermoplastic resin containing a conductive filler and containing 70% by weight or more of an aromatic polyester resin. TECHNICAL FIELD The present invention relates to a polyester resin tube and its use. More specifically, a heat-shrinkable tube obtained by stretching an aromatic polyester resin composition containing a conductive filler, characterized in that the crystallinity of the stretched tube is not more than a specific value. The present invention relates to a heat-shrinkable conductive aromatic polyester resin tube and an inorganic material product whose surface is coated with a layer obtained by heat-treating the tube.

[0002]

2. Description of the Related Art Conventionally, the materials used for the protective layer of charging roller parts used in copying machines, printers, etc. are
A coating liquid containing conductive carbon black as a main component is mainly used to impart conductivity. In recent years, a heat-shrinkable tube having conductivity has been attracting attention as an alternative to the simplification of the process and the reduction of labor at the time of disposal for the purpose of cost reduction. However, when a heat-shrinkable tube is used, it is difficult to produce a thin product such as a coating layer, and there are major problems in surface smoothness, chemical stability and coating processability. The following characteristics are mainly required for the heat shrinkable tube for coating in charging roller parts such as copying machines and printers.

First, the heat-shrinkable tube has good electrical characteristics. That is, the volume resistivity is 10 ⁶
Less variation within the range of -10 ¹⁰ Ω · cm. Further, it is required that the resistance value does not fluctuate in the facility environment and during use. Secondly, it has excellent chemical stability. That is, the heat-shrinkable tube is required to be chemically stable against the photoconductor, the toner, and the plasticizer contained in the rubber elastic layer, which are in direct contact with each other. Thirdly, the surface smoothness is required to mechanically remove the toner adhering to the surface. Fourthly, the heat-shrinkable tube has good coating workability.

In order to improve the above characteristics in a charging roller used in an electrophotographic image forming apparatus such as a copying machine or a printer, JP-A-9-160352 discloses a polyolefin-based outermost layer in contact with a photoreceptor. It has been proposed to use heat shrinkable tubing.
However, the tube proposed above has a problem that the wall thickness after shrinkage is 150 to 500 μm, which is larger than that of the conductive coating layer, and the machinability is poor. Further, there is a problem that the plasticizer contained in the rubber elastic layer is slightly unstable chemically. Further, JP-A-8-262873 proposes to use a specific conductive carbon black as a coating liquid for forming a coating layer. However, with the method proposed here, it is difficult to obtain a uniform thickness and surface smoothness, and there is a problem that labor is required for recycling and sorting at the time of disposal, as compared with a heat-shrinkable tube. Therefore, without the above-mentioned inconvenience, for example, the electric characteristics are good in a state of being coated on the charging roller,
The appearance of a thin-walled heat-shrinkable tube having excellent coating processability has been demanded.

[0005]

DISCLOSURE OF THE INVENTION The present invention relates to an aromatic polyester resin tube containing a conductive filler, and in particular, a polyester tube formed from an aromatic polyester having ethylene terephthalate units as main repeating units. It is an object of the present invention to provide a heat-shrinkable conductive aromatic polyester resin tube which has good electrical properties when coated on other parts and is excellent in chemical stability, and further has excellent surface smoothness, shrinkage characteristics and openability. To do. The present inventor has conducted extensive studies to achieve the above object. In particular, the difference in crystallization characteristics when a tube made of an aromatic polyester containing ethylene terephthalate units containing a conductive filler as the main repeating unit is stretched affects the final coating processability and surface smoothness. It was considered that it would give. As a result, surprisingly, a heat-shrinkable conductive aromatic compound satisfying that the stretched tube obtained by stretching the aromatic polyester resin tube containing the conductive filler has a crystallinity within a specific value range. It has been found that the group polyester resin tube can solve the above-mentioned object, and completed the present invention.

[0006]

Means for Solving the Problems The present invention comprises: (1) (A) 100 parts by weight of a thermoplastic resin (A component) containing 70% by weight or more of an aromatic polyester resin (A),
A tube formed from a resin composition containing 0.5 to 50 parts by weight of a conductive filler (component B), wherein the crystallinity of the aromatic polyester resin in the tube is less than 4%. 2. A heat-shrinkable conductive aromatic polyester resin tube according to item 1), wherein the tube has an inner diameter of 3 mm to 300 mm and a wall thickness of 25 μm to 125 μm. 3) The heat-shrinkable electrically conductive aromatic polyester resin tube according to item 1) or 2), wherein the aromatic polyester resin is an aromatic polyester having an ethylene terephthalate unit as a main repeating unit, 4) the electrically conductive filling 5. The heat-shrinkable conductive aromatic polyester resin tube according to any one of items 1) to 3), wherein the material is conductive carbon black. An acetylene black conductive filler, an average primary particle size is and a specific surface area 25 to 60 nm 30
The heat-shrinkable electrically conductive aromatic polyester resin tube according to any one of Items 1) to 4), which has a content of 0 m ² / g or less.

6) The heat-shrinkable conductive aromatic polyester resin tube according to any one of items 1) to 5), wherein the aromatic polyester resin is amorphous, 7) the heat-shrinkable conductive aromatic The polyester resin tube was obtained by stretching an unstretched conductive aromatic polyester resin tube 1.2 to 4.0 times in the radial direction of the tube and 1.0 to 4.0 times in the length direction of the tube. The heat-shrinkable electrically conductive aromatic polyester resin tube according to any one of 1) to 7), 8) the heat shrinkage rate when immersed in hot water at 100 ° C. for 30 seconds is 10 in the radial direction of the tube. 60% and 0 to 40% in the length direction of the tube, wherein the heat-shrinkable conductive aromatic polyester resin tube according to any one of items 1) to 7), 9) 70% by weight of the aromatic polyester resin. Thermoplastic resin (including A tubular layer formed from a resin composition containing 0.5 to 50 parts by weight of (B) a conductive filler (B component) with respect to 100 parts by weight of the (A component), and the inner diameter of the tubular layer is An inorganic material product whose surface is coated with a layer having a thickness of 2.5 mm to 295 mm and a thickness of 26 μm to 130 μm, 10) the aromatic polyester resin is an aromatic polyester having ethylene terephthalate units as main repeating units. Item 9) surface-coated inorganic material product, 11) Item 9) or Item 10) surface-coated inorganic material product, wherein the conductive filler is conductive carbon black, 12) an acetylene black conductive fillers, according to the average primary particle size of 25 to 60 nm, and specific surface area is less than 300 meters ² / g, any one of Items 9) to claim 11) A surface-coated inorganic material product, 13) wherein the tubular layer is obtained by heat-shrinking the heat-shrinkable conductive aromatic polyester resin tube according to any one of items 1) to 8). , Item 9) to item 1
Item 14. The inorganic material product coated with the surface according to any one of 2), and 14) the inorganic material product is a charging roller, a transfer roller or a developing roller. A surface-coated inorganic material product.

The details of the present invention will be described below. The aromatic polyester resin (hereinafter sometimes abbreviated as polyester resin) in the present invention is preferably 70 mol% or more, preferably 100 mol% or more based on 100 mol% of the dicarboxylic acid component of the dicarboxylic acid component and the diol component forming the polyester resin. Is a polyester resin in which 90 mol% or more, and most preferably 99 mol% or more is an aromatic dicarboxylic acid.

Examples of this dicarboxylic acid include terephthalic acid, isophthalic acid, 2-chloroterephthalic acid and 2,5-
Dichloroterephthalic acid, 2-methylterephthalic acid, 4,
4-stilbenedicarboxylic acid, 4,4-biphenyldicarboxylic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, bisbenzoic acid, bis (p-carboxyphenyl) methane, anthracenedicarboxylic acid, 4,4-diphenyl ether dicarboxylic acid, 4,4-diphenoxyethane dicarboxylic acid, 5
-Na sulfoisophthalic acid, ethylene-bis-p-benzoic acid and the like can be mentioned. These dicarboxylic acids can be used alone or in admixture of two or more. The aromatic polyester resin of the present invention may be copolymerized with an aliphatic dicarboxylic acid component of less than 30 mol% in addition to the above aromatic dicarboxylic acid. Specific examples thereof include adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, and 1,3.
-Cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid and the like.

Examples of the diol component of the present invention include ethylene glycol, diethylene glycol, 1,2-propylene glycol, 1,3-propanediol, and 2,2.
-Dimethyl-1,3-propanediol, trans- or -2,2,4,4-tetramethyl-1,3-cyclobutanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, 1,3
-Cyclohexanedimethanol, decamethylene glycol, cyclohexanediol, p-xylenediol,
Examples thereof include bisphenol A, tetrabromobisphenol A, tetrabromobisphenol A-bis (2-hydroxyethyl ether) and the like. These may be used alone or in combination of two or more.

Specific examples of the aromatic polyester resin composed of such a dicarboxylic acid component and a diol component include polyethylene terephthalate resin, polybutylene terephthalate resin, polyethylene isophthalate resin,
Polyethylene naphthalate resin, polybutylene naphthalate resin, polyethylene (terephthalate / isophthalate) copolymer resin [where, "(a / b)" such as "(terephthalate / isophthalate)" means a and b It means that the above components are present as a copolymerization component in a mixed state. same as below. ], Poly (ethylene / 1,4-
Examples thereof include dimethylene / cyclohexane) terephthalate copolymer resin and poly (ethylene / neopentylene) terephthalate copolymer resin.

Among them, polyethylene terephthalate resin,
A polyethylene naphthalate resin, a polyethylene (terephthalate / isophthalate) copolymer resin, and a poly (ethylene / 1,4-dimethylene cyclohexane) terephthalate copolymer resin are preferable. Further, a polyethylene terephthalate resin, a polyethylene (terephthalate / isophthalate) copolymer resin, and a poly (ethylene / 1,4-dimethylene cyclohexane) terephthalate copolymer resin are more preferable. A more preferable form is poly (ethylene /
1,4-dimethylene / cyclohexane) terephthalate copolymer resin. The aromatic polyester of the present invention is particularly preferably one in which the main repeating unit is an ethylene terephthalate unit, and particularly preferably one in which ethylene terephthalate units account for 50 mol% or more, preferably 60 mol% or more, of all the repeating units. .

These resins may be used alone or in combination of two or more. Polyethylene terephthalate resin, polybutylene terephthalate resin, polyethylene isophthalate resin, polyethylene (terephthalate /
Isophthalate) copolymer resin, poly (ethylene / 1,4)
-Dimethylene / cyclohexane) terephthalate copolymer resin and poly (ethylene / neopentylene) terephthalate copolymer resin are polyethylene naphthalate resin, for the purpose of further improving heat resistance while maintaining heat shrinkability.
The polybutylene naphthalate resin can be mixed in an amount of 10 to 30% by weight. The terminal group structure of the aromatic polyester resin used in the present invention is not particularly limited,
In addition to the case where the ratio of the hydroxyl group and the carboxyl group in the terminal group is almost the same, the case where one ratio is large may be used. Further, those terminal groups may be blocked by reacting a compound having reactivity with such terminal groups.

Regarding the method for producing the aromatic polyester resin used in the present invention, the dicarboxylic acid component and the diol component are heated in the presence of a polycondensation catalyst containing titanium, germanium, antimony, etc. according to a conventional method. Is polymerized, and by-produced water or lower alcohol is discharged to the outside of the system. For example, as the germanium-based polymerization catalyst, germanium oxide, hydroxide, halide, alcoholate, phenolate and the like can be exemplified, and more specifically, germanium dioxide, germanium hydroxide, germanium tetrachloride, tetramethoxygermanium, Examples thereof include antimony trioxide and the like.
In the present invention, compounds such as manganese, zinc, calcium and magnesium used in the transesterification reaction which is a prior stage of polycondensation which is conventionally known can be used in combination.
Further, it is also possible to deactivate such a catalyst with a compound of phosphoric acid or phosphorous acid after completion of the transesterification reaction to carry out polycondensation.

The aromatic polyester can be produced by either a batch method or a continuous polymerization method. The intrinsic viscosity of the aromatic polyester resin is preferably 0.4 to 1.5, more preferably 0.5 to 1.0, and even more preferably 0.55 in the intrinsic viscosity measured at 35 ° C. with o-chlorophenol as a solvent. ~ 0.95 is more preferable, and 0.6
~ 0.9 is particularly preferred. If the intrinsic viscosity is less than 0.4, the mechanical properties, breaking strength and elongation of the tube will be low, and 1.
If it exceeds 5, the melt processability of the tube is deteriorated, which is not preferable. The polyester resin constituting the tube of the present invention,
It may be one kind or two or more kinds. For example, a terephthalic acid / isophthalic acid (TA / IA) copolymer resin can be used alone or in a mixture with a polyethylene terephthalate (PET) resin. This TA / IA copolymer resin and PET resin mixed resin Isophthalic acid in 100 mol% of the acid component is 0.1 to 20 mol%, preferably 0.1 to 15 mol%, and more preferably 0.1 to 1 mol%.
It can also be used by blending so as to be 0 mol%.

The polymer copolymerized with the polyester resin may be a block copolymer or a random copolymer. For example, TA / IA copolymer resin is
It may be a block copolymer consisting essentially of polyethylene terephthalate chains and polyethylene isophthalate chains, or a random copolymer of ethylene terephthalate units and ethylene isophthalate units. The aromatic polyester resin, especially the aromatic polyester resin having ethylene terephthalate units as main repeating units, is preferably 70% by weight or more, and more preferably 80% by weight or more based on 100% by weight of the thermoplastic resin. The thermoplastic resin of the present invention may be mixed with 30% by weight or less of 100% by weight of the aromatic polyester resin other than the above aromatic polyester or other thermoplastic resin.

Other thermoplastic resins include polysulfone resins, polyether ether ketone resins, polyphenylene sulfide resins, polyphenylene ether resins; polyolefin resins such as polyethylene resins and polypropylene resins; polystyrene resins, ABS resins, AS resins, M
Styrene resin such as BS resin; other polycarbonate resin, polyamide resin, acrylic resin, and various thermoplastic elastomers (for example, styrene resin, olefin resin, urethane resin, polyester resin, polyamide resin, 1,
2-polybutadiene type, vinyl chloride type, fluorine type [fluorine rubber], ionomer resin, chlorinated polyethylene, silicone type, etc.). Furthermore, IPN (Interp
A composite rubber of acrylic rubber and silicone rubber using enetrating Polymer Networks technology. For example, Mitsubishi Rayon Co., Ltd., trade name Metabrane S-2001
Etc. One kind or two or more kinds of thermoplastic resins other than these polyester resins can be used.

Among the thermoplastic resins other than these polyester resins, a thermoplastic polyester elastomer resin having good compatibility with the polyester resin is preferable from the viewpoint of improving hot water resistance. This thermoplastic polyester-based elastomer resin (hereinafter sometimes abbreviated as TPEE resin) uses an aromatic polyester having a high melting point and a high crystallinity for a hard segment, and an amorphous polyester or an amorphous polyether for a soft segment. Is a resin using.
The former is a polyester ester resin and the latter is a polyether ester resin. Such a polyetherester resin has a hard segment of 5 to 95% by weight and a soft segment of 5 to 95% by weight when the polyetherester resin is 100% by weight, and its intrinsic viscosity is 0.4 to 2.2.
The range is 0. The aromatic polyester as the hard segment of the polyether ester resin can use the dicarboxylic acid and diol components constituting the aromatic polyester resin described above, and the melting point of this segment is 10
It is preferably 0 ° C or higher.

Specifically, polybutylene terephthalate or polybutylene naphthalate which is essentially composed of 1,4-butanediol and terephthalic acid or naphthalenedicarboxylic acid is preferable. Such polybutylene terephthalate or polybutylene naphthalate includes 1,4-
Other diols other than butanediol, such as ethylene glycol, diethylene glycol, triethylene glycol, neopentyl glycol, cyclohexanedimethanol can be copolymerized in an amount of 5 mol% or less in 100 mol% of all diol components, and other than terephthalic acid. Other dicarboxylic acids, isophthalic acid, naphthalenedicarboxylic acid, etc., preferably isophthalic acid, are used as the total dicarboxylic acid component 10.
It is possible to copolymerize 0 mol% or less and 10 mol% or less.
Most preferably, it is polybutylene terephthalate consisting only of 1,4-butanediol and terephthalic acid.

The soft segment of the polyether ester resin is mainly composed of polyether glycol whose alkylene portion is alkylene having 3 to 12 carbon atoms or cycloalkylene having 4 to 10 carbon atoms. Typical examples of such polyether glycols include polyether glycols such as polypropylene glycol, polytrimethylene glycol, and polytetramethylene glycol, or copolyethylene-propylene glycol, copolyethylene-tetramethylene glycol [where the ethylene oxide unit is 50% by weight or less of ether glycol], copolytetramethylene-1,2-cyclohexylene dimethylene glycol [wherein 1,2-cyclohexylene dimethylene oxide unit is 1 to 20 mol% of copolyether glycol] ] And other copolyether glycols. Of these, polytetramethylene glycol is preferred.

The polyester ester resin has a hard segment of 5 to 95% by weight and a soft segment of 5 to 95% by weight when the polyester ester resin is 100% by weight, and its intrinsic viscosity is 0.4 to 2.0. It is a range. The hard segment aromatic polyester of the polyester ester resin may use the dicarboxylic acid and diol components constituting the aromatic polyester resin described above, and the melting point of this segment is preferably 100 ° C. or higher.
Specifically, polybutylene terephthalate consisting essentially of 1,4-butanediol and terephthalic acid is preferable. Such polybutylene terephthalate includes diols other than 1,4-butanediol, such as ethylene glycol, diethylene glycol, triethylene glycol,
Neopentyl glycol, cyclohexane dimethanol, etc. can be copolymerized in an amount of 5 mol% or less in 100 mol% of all diol components, and dicarboxylic acids other than terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, etc., preferably isophthalic acid can be used. 100 mol% of all dicarboxylic acid components
Up to 10 mol% can be copolymerized. Most preferably, it is polybutylene terephthalate consisting only of 1,4-butanediol and terephthalic acid.

In the soft segment of the polyester ester resin, polycaprolactone, an aliphatic polyester (for example, polyethylene adipate) from the above-mentioned aliphatic dicarboxylic acid and an aliphatic diol, and the main component of the dicarboxylic acid component are aromatic dicarboxylic acids. , The alkylene portion is an alkylene having 3 to 12 carbon atoms or 4 to 1 carbon atoms
It is a polyester ether (hereinafter sometimes abbreviated as aromatic polyester ether) with a diol component mainly composed of 0 polyether glycol which is cycloalkylene. Of these, aromatic polyester ethers are preferable.

As the dicarboxylic acid component of such an aromatic polyester ether, 70 mol% or more of aromatic dicarboxylic acid is preferable in 100 mol% of dicarboxylic acid component, more preferably 80 to 99 mol%, most preferably 90 to 90 mol%. It is 98 mol%. As such an aromatic dicarboxylic acid, terephthalic acid, isophthalic acid and naphthalenedicarboxylic acid are preferable, and isophthalic acid is most preferable.
The aliphatic dicarboxylic acid may be copolymerized with adipic acid, sebacic acid, azelaic acid, etc., preferably adipic acid of less than 30 mol%, more preferably 1 to 20 mol%, most preferably 2 to 10 mol%. it can. On the other hand, as typical examples of the diol component of this aromatic polyester ether, polyether glycol such as polypropylene glycol, polytrimethylene glycol, polytetramethylene glycol or copolyethylene-propylene glycol, copolyethylene-tetramethylene glycol [however, ethylene Oxide unit comprises 50% by weight or less of copolyether glycol], copolytetramethylene-1,2-cyclohexylene dimethylene glycol [wherein 1,2-cyclohexylene dimethylene oxide unit is 1 to 20 of copolyether glycol]. Consisting of mol%]. Of these, polytetramethylene glycol is preferred.

The conductive filler which is the component B of the present invention is
A filler having a volume resistivity of 1 Ω · m or less. Examples of such conductive fillers include metal-based conductive fillers, non-metal-based conductive fillers such as metal oxides, and carbon-based conductive fillers. Examples of the metal-based conductive filler include powders and flakes of various metals such as aluminum, copper, iron, nickel and silver. Furthermore, it is also possible to use those obtained by coating the surface of various fillers with these metals by a method such as vapor deposition or plating. Examples thereof include glass short fibers, glass flakes, short carbon fibers, mica, wollastonite, and the like, the surface of which is coated with nickel, copper, gold, silver, or the like. Examples of the non-metal conductive filler include powders of tin oxide, zinc oxide and the like. Further, a type in which fine particles such as tin oxide are coated on the surface of another metal oxide can be mentioned. For example, aluminum substrate surface coated with zinc oxide, titanium oxide surface coated with tin oxide, aluminum borate surface coated with tin oxide, potassium titanate surface coated with tin oxide. And so on.

Further, examples of the carbon-based conductive filler include carbon black (conductive oil furnace black, channel black, lamp black, acetylene black, thermal black, etc.), graphite, carbon fiber and the like. As the carbon fiber, an extremely fine carbon fiber having a diameter of 1 μm or less is preferable from the viewpoint of impact resistance. Such carbon fibers can be produced by a vapor growth method and a method of spinning and carbonizing a formalin condensate of an aromatic sulfonate without passing through an infusibilizing step. Among the above, conductive carbon black is more preferable from the viewpoint of compatibility of surface smoothness, impact resistance and conductivity, and among them, acetylene black is particularly preferable as the conductive filler.

The conductive carbon black has an average primary particle diameter of 100 nm or less and a DBP oil absorption of 100.
~ 500ml / 100g, specific surface area of 1500m ² / g
The following conductive carbon black is used. Preferably, the average primary particle size is 25 to 75 nm, the DBP oil absorption is 100 to 350 ml / 100 g, and the specific surface area is 1000.
m ² / g or less, more preferably an average primary particle diameter of 25 to 60 nm and a DBP oil absorption of 100 to 200 ml /
100 g, specific surface area is 300 m ² / g or less. The conductive filler is 0.5 to 100 parts by weight of the thermoplastic resin.
It is preferably 50 parts by weight, more preferably 1 to 35 parts by weight, still more preferably 5 to 30 parts by weight. If it is less than 0.5 parts by weight, the conductivity will be insufficient, and if it is more than 50 parts by weight, the melt processability of the tube will be deteriorated.

The most preferable embodiment of the method for producing the tube of the present invention is a method in which an unstretched tube is extruded using a ring die and then stretched to obtain a heat-shrinkable tube. In addition, there is a method in which a film extruded / stretched using a T-die or an I-die is attached by fusion, welding or adhesion to form a tube, and further, the tube or film is attached in a spiral shape to form a tube. . Here, a method of extruding an unstretched tube using a ring die and then stretching it to obtain a heat-shrinkable tube will be described in more detail. The above-mentioned resin composition comprising an aromatic polyester resin is heated and melted at a temperature equal to or higher than the melting point by a melt extrusion device, continuously extruded from a ring die, then forcibly cooled and molded into an unstretched tube. As a method of forced cooling, a method of immersing in cold water, a method of using cooling air, or the like can be used. Among them, the method of soaking in low temperature water is effective because of high cooling efficiency.
This unstretched tube may be continuously supplied to the next stretching step, or may be once wound into a roll and then used as a raw material for the next stretching step. From the viewpoint of production efficiency and thermal efficiency, a method of continuously supplying an unstretched tube to the next stretching step is preferable.

The unstretched tube thus obtained is biaxially stretched by applying a compressed gas from the inside of the tube. The stretching method is not particularly limited, for example, from one end of the unstretched tube is fed at a constant rate while applying a pressure of compressed gas to the inside of the tube, then preheated by hot water or an infrared heater, etc., in the radial direction. Biaxial stretching is carried out by placing in a stretching tube heated to a stretching temperature that regulates the stretching ratio. Temperature conditions and the like are set so that the film is drawn at an appropriate position in the drawing tube. After stretching, it is cooled, sandwiched by a pair of nip rolls, and stretched and wound as a stretching tube while maintaining the stretching pressure. Stretching may be performed in either the length direction or the radial direction, but it is preferable to perform the stretching at the same time. The stretching ratio in the length direction is determined by the ratio of the feed speed of the unstretched tube to the nip roll speed after stretching, and the stretching ratio in the radial direction is determined by the ratio of the unstretched outer diameter and the stretched tube outer diameter.
As a stretching pressurizing method other than this, a method of maintaining the internal pressure of the compressed gas enclosed by sandwiching both the unstretched tube delivery side and the stretched tube take-up side with nip rolls can be adopted.

The stretching conditions differ depending on the properties of the polymer used and the heat shrinkability of the target tube, but the stretching temperature is usually the glass transition temperature (Tg ° C.) to (Tg + 50) of the resin.
The temperature is selected within the range of 100 ° C., and the stretching is conveniently performed using hot water in the vicinity of 100 ° C. The heat-shrinkable conductive aromatic polyester resin tube of the present invention is obtained by stretching an unstretched tube in its radial direction by 1.2 to 4.0 times and in its length direction by 1.0 to 4.0 times. The obtained one is preferable. Further, the draw ratio in the radial direction of the tube is preferably 1.3 to 3.5 times, more preferably 1.4 to 3.0 times, and 1.4 to 3.0 times.
2.0 times is more preferable. The draw ratio in the lengthwise direction of the tube is preferably 1.02 to 3.5 times, more preferably 1.02 to 3.0 times, and even more preferably 1.02 to 1.3 times. If the stretching ratio in the radial direction of the tube is less than 1.2 times, a sufficient shrinkage amount may not be obtained. On the other hand, if it exceeds 4 times, it becomes difficult to keep the crystallinity at a predetermined ratio while satisfying the heat resistance. Furthermore, it is difficult to control the draw ratio in the length direction of the tube.

When the stretching ratio in the lengthwise direction of the tube exceeds 4.0 times, the shrinkage amount in the lengthwise direction becomes large, which makes it difficult to stably coat the components and the like, and the yield of the components is reduced. There is. The heat-shrinkable conductive aromatic polyester resin tube of the present invention has a crystallinity of less than 4.0% when formed into a stretched tube. It is preferably 3.8% or less, and particularly preferably 3.5% or less. For the crystallinity, the density of the sample is measured by the density gradient tube method, and the density when the conductive filler is removed is calculated based on the result.
After that, the density of the sample that has been heat-treated at a high temperature of 200 ° C or higher for 24 hours is measured, and the ratio of the crystal part is obtained by X-ray diffraction. To do. The density when completely amorphous is measured in advance. From the above results, the crystallinity of the sample was obtained. In order to obtain such crystallinity, the structure of the component A, the type and content of the component B, the tube manufacturing method, etc. are important factors.

The heat-shrinkable conductive aromatic polyester resin tube of the present invention preferably has a heat shrinkage rate of 10 to 60 in the radial direction of the tube when immersed in hot water at 100 ° C. for 30 seconds.
%, And 0 to 40% in the length direction of the tube. Such shrinkage range provides good coverage, such as on the part being coated. As a more preferable range, the heat shrinkage ratio is 20 to 50% in the radial direction of the tube and 1 to 2 in the longitudinal direction of the tube.
It is 0%. The resin composition of the present invention may be used by previously mixing the above components with a mixer such as a tumbler, a V-type blender, a Nauter mixer, a Banbury mixer, a kneading roll, and an extruder, and using an unstretched tube. Directly feed each measured component to the extruder feed port,
Furthermore, the components weighed separately may be fed to each feed port of an extruder having two or more feed ports.

Further, various additives and inorganic fillers may be added in an amount that produces the effect within the range not impairing the object of the present invention. As various additives, flame retardants [brominated bisphenol, brominated polystyrene, carbonate oligomer of brominated bisphenol A, triphenyl phosphate, resorcinol bis (dixylenyl phosphate), bisphenol A bis (diphenyl phosphate), red phosphorus, etc.] , Flame retardant aid (sodium antimonate, antimony trioxide, etc.), anti-drip agent (polytetrafluoroethylene, etc., which has fibril-forming ability), antioxidant (hindered phenolic compound, etc.), UV absorber, mold release Agents, lubricants, coloring agents and the like. Examples of the inorganic filler include glass beads, talc and mica.

The resin composition of the present invention has a water content of 0.1% by weight in order to prevent hydrolysis of the aromatic polyester resin.
After that, it is dried preferably to 0.05% by weight or less. For example, 170 ℃ for 3 hours, 150 ℃ for 12 hours,
Dry under vacuum at 120 ° C. for 24 hours or the like. Thus, according to the present invention, there is also provided a product obtained by coating the surface of various inorganic material products using the heat-shrinkable aromatic polyester resin tube. The product to be coated on the surface should be one that can utilize the characteristics (conductivity, heat resistance, chemical resistance, mechanical characteristics such as high elastic modulus) of the main component conductive aromatic polyester resin. Well, examples include inorganic material products. Specifically, as an inorganic material product, it can be used as a covering tube for roller parts such as a charging roller, a transfer roller and a developing roller.

Inorganic material products, in particular, a method of providing a coating tube on roller parts such as a charging roller, a transfer roller and a developing roller is basically the method of providing a heat-shrinkable conductive aromatic compound of the present invention on these products or parts. A polyester resin tube is covered and then heat treated. The conditions of such heat treatment vary depending on the size of the roller component to be coated, but it is preferable to perform heat treatment in a hot air dryer at a temperature of 80 ° C to 150 ° C for several minutes to 30 minutes. Furthermore, in order to finish the coating appearance after shrinkage in these products well, before coating the heat-shrinkable conductive aromatic polyester resin tube of the present invention, roller parts such as a charging roller, a transfer roller, a developing roller, etc. It is preferable to keep it warm.
The heat retention temperature is preferably in the range of 40 ° C to 60 ° C.
By such a treatment, a conductive aromatic polyester resin tubular layer is formed on the surface of the product or component as described above. The conductive aromatic polyester resin tubular layer contains (B) a conductive filler (B component) of 0.5 to 100 parts by weight of a thermoplastic resin (A component) containing 70% by weight or more of an aromatic polyester resin. A tubular layer formed from a resin composition containing 50 parts by weight, wherein the tubular layer has an inner diameter of 2.5 mm to 295 mm and a wall thickness of 26.
The layer has a thickness of μm to 130 μm.

[0035]

EXAMPLES The present invention will now be described in more detail with reference to examples. In addition, the typical physical properties in the examples were measured by the following methods. (1) Heat shrinkage rate A heat shrinkable tube with a length of 10 cm was immersed in hot water at 100 ° C.
The length before and after soaking for 0 seconds and the outer diameter were measured with a digital caliper and calculated from the following formula. Five samples were measured and the average value was calculated. Thermal shrinkage (%) = {[(length before hot water immersion)-(length after hot water immersion)] / (length before hot water immersion)} × 100 (2) Crystallinity For the crystallinity of the heat-shrinkable tube, the density of the sample is measured by the density gradient tube method, and the density when the conductive filler is removed is calculated based on the result. After that, the density of the sample that has been heat-treated at a high temperature of 200 ° C or higher for 24 hours is measured, and the ratio of the crystal part is obtained by X-ray diffraction. To do. The density when completely amorphous is measured in advance. From the above results, the crystallinity of the sample was obtained. (3) Volume resistivity According to JIS K 7194. (4) Stability of volume resistivity A pipe made of a polycarbonate resin is covered with a conductive heat-shrinkable tube, and the volume resistivity before and after wet heat treatment is measured. (Wet heat treatment condition: 50 ° C. × 50% RH × 10
Day)

(5) Chemical stability A conductive heat-shrinkable tube is coated on a charging roller, and the appearance of the tube after wet heat treatment is visually evaluated. (Wet heat treatment condition: 50 ° C. × 50% RH × 10 days) As the charging roller, one having a conductive elastic layer (containing acetylene / carbon black) made of butadiene acrylonitrile rubber on a stainless steel metal shaft is used. Number of test samples: 5 ○: No change in the heat-shrinkable tube such as bleeding, tube swelling and cracks due to the plasticizer is observed after the wet heat treatment. Δ: A slight change in the heat-shrinkable tube due to bleeding of the plasticizer is observed after the moist heat treatment. However, as a product, there is no problem. X: After heat-moisture treatment, changes in the heat-shrinkable tube such as bleeding, tube swelling, and cracking due to the plasticizer occurred. (6) Surface smoothness The surface appearance of the conductive heat-shrinkable tube is visually evaluated. ◯: The conductive carbon black does not float and the surface appearance is good. Δ: The conductive carbon black is slightly floated and the surface is slightly rough. X: The conductive carbon black is floating and the surface is rough. (7) After being pressure-bonded with a roll so that air did not remain on the inner surface of the open conductive heat-shrinkable tube, the wound tube was bent parallel to the length direction and evaluated as follows. ◯: The mouth opens with only one bending, and the opening is good. Δ: The opening returns twice, and the opening does not open even after folding three times or more, and the opening is poor. (8) Image characteristics Using a copying machine whose roller was covered with the conductive heat-shrinkable tube of the present invention, a large number of copies were continuously taken, and image comparison with the initial one was performed. As a result of comparing the initial one and the one obtained when a large number of sheets were taken, one having almost no change was evaluated as ◯.

Examples 1 to 5 and Comparative Example 1 The resin compositions shown in Table 1 were melted by an extruder set at a cylinder temperature of 270 ° C., extruded through a ring die, dipped in water and solidified by cooling to obtain an unstretched product. 90 tube as it is
4.9 in a warm water of ℃, using a stretch tube with an inner diameter of 18.8 mm
An internal pressure was applied to the tube by a compressed air of × 10 ⁴ Pa (0.5 kg / cm ² ), and the tube was drawn under the conditions shown in Tables 1 and 2 and then cooled with water to obtain a drawn heat-shrinkable tube having a thickness of 50 μm.
The shape and properties of the resulting heat-shrinkable tube are shown in Tables 1 and 2. The abbreviations in Tables 1 and 2 mean the following. (A-1) Polyethylene terephthalate resin PET-1: Acid component is 100 mol% terephthalic acid, diol component is 68 mol% ethylene glycol, 30 mol% 1,4-cyclohexanedimethanol, 2 mol% diethylene glycol, and [η] = 0.78 amorphous polyethylene terephthalate resin PET-2: Polyethylene of [η] = 0.7, wherein the acid component is 89 mol% terephthalic acid, 11 mol% isophthalic acid, and the diol component is 100 mol% ethylene glycol. Terephthalate / isophthalate resin PET-3: prepared by using 100 mol% of terephthalic acid as an acid component and 100 mol% of ethylene glycol as a diol component,
The amount of diethylene glycol by-product after production is 3.4 mol%
A polyethylene terephthalate resin PET-4 having [η] = 0.85: an acid component of 100 mol% terephthalic acid and a diol component of 100 mol% ethylene glycol,
The amount of diethylene glycol by-product after production is 1.2 mol%
A polyethylene terephthalate resin (A-2) having an [η] of 0.65, an aromatic polyester resin TPE: a polyester elastomer resin, a polyether ester in which the hard segment is polybutylene terephthalate and the soft segment is polytetramethylene glycol. resin. (B) Conductive filler Conductive carbon black-1 (CB-1); Acetylene black conductive carbon black-2 (CB-) having a primary particle diameter of 42 nm, a DBP oil absorption amount of 115 ml / 100 g and a specific surface area of 61 m ² / g. 2); Oil furnace black having a primary particle diameter of 25 nm, a DBP oil absorption amount of 350 ml / 100 g, and a specific surface area of 1,000 m ² / g.

Example 6 A charging roller having a conductive elastic layer (containing acetylene / carbon black) made of butadiene acrylonitrile rubber on a metal shaft made of stainless steel was coated with the conductive heat-shrinkable tube obtained in Example 1 and heat-treated. After shrinking,
Wet heat treatment was performed (treatment condition: 50 ° C. × 50% RH ×
10th). Then, the charging roller before and after the treatment was incorporated into a commercially available copying machine, and a large number of copies were continuously taken to compare the images with those at the initial stage. As a result, the charging characteristics were almost unchanged before and after the treatment. .

Example 7 A conductive elastic layer made of ethylene propylene rubber (acetylene.
The conductive heat-shrinkable tube obtained in Example 1 was coated on a transfer roller containing carbon black) and heat-shrinked. Then, the transfer roller was incorporated into a commercially available copying machine, and a large number of copies were continuously taken to compare the images with those at the initial stage (the contact pressure between the photosensitive drum and the transfer roller was 300 g / cm ² or less, and the contact width was 2 mm). As a result, the transfer characteristics were almost unchanged.

Example 8 A magnet roller is arranged on a metal shaft, and the outside of the magnet roller is coated with the conductive heat-shrinkable tube obtained in Example 1 on a developing roller having a cylindrical pipe made of aluminum. , Heat shrunk. Then, the developing roller was incorporated into a commercially available copying machine using a one-component magnetic developer, and a large number of copies were continuously taken to compare the images with those at the initial stage (30 between the photosensitive drum and the developing roller).
0 μm). As a result, the developing characteristics were almost unchanged.

[0041]

[Table 1]

[0042]

[Table 2]

[0043]

The aromatic polyester resin of the present invention is 70
A tube formed from a resin composition in which a thermoplastic resin containing more than or equal to wt% and a conductive filler is added has a crystallinity of the tube obtained by stretching of less than 4.0%. It has excellent shrinkage characteristics and openability when coating parts, and also when coated with charging roller parts,
It is chemically stable to the plasticizer and toner contained in the rubber layer and has excellent surface smoothness. Further provided is a heat-shrinkable aromatic polyester resin tube which can utilize the conductivity, combustion resistance and chemical resistance of the above resin composition and can utilize these characteristics as a coating material or a protective material. In addition, the present invention provides an industrially advantageous method for producing the tube and an inorganic material product obtained by coating or protecting various products by utilizing the heat shrinkability.

Therefore, it is very useful for replacing the conventional conductive coating layer with a conductive coating liquid.

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) F16C 13/00 F16C 13/00 E 4F210 G03G 15/00 550 G03G 15/00 550 4J002 15/02 101 15/02 101 15 / 08 501 501 08 501D 15/16 103 15/16 103 // B29K 67:00 B29K 67:00 105: 16 105: 16 B29L 23:00 B29L 23:00 F term (reference) 2H071 BA43 DA06 DA08 DA09 2H077 AD06 FA13 FA26 FA27 2H200 HA02 HA28 HB12 HB45 HB46 HB47 JA02 JA25 JA26 JA27 MA04 MA12 MA13 MA14 MA20 MB04 MC06 MC20 3J103 AA02 AA51 AA85 FA18 GA57 GA58 HA45 HA54 4F071 AA46 AB03 AD02 AD06 AE15 AF28 BB08A05A16 AF12 AH46 AF12 AH46 AF12 AF16 AH46 AF12 AA24D AB11 AB18 RA03 RC02 RG02 RG07 RG43 4J002 BB032 BB122 BC062 BN152 BN162 CF041 CF061 CF071 CF081 CF102 CF171 CH072 CH092 CN012 CN032 DA036 DA076 DA086 DE096 DE106 DJ006 DJ056 DL006 FA76 FA01646FB0

Claims (14)

[Claims] 1. A conductive filler (component B) in an amount of 0.5 to 50 parts by weight per 100 parts by weight of a thermoplastic resin (component A) containing 70% by weight or more of an aromatic polyester resin (A). A tube formed from the resin composition,
A heat-shrinkable electrically conductive aromatic polyester resin tube, characterized in that the crystallinity of the aromatic polyester resin in the tube is less than 4%. 2. The inner diameter of the tube is 3 mm to 300 mm
The heat-shrinkable conductive aromatic polyester resin tube according to claim 1, which has a wall thickness of 25 μm to 125 μm. 3. The heat-shrinkable electrically conductive aromatic polyester resin tube according to claim 1, wherein the aromatic polyester resin is an aromatic polyester having an ethylene terephthalate unit as a main repeating unit. 4. The heat-shrinkable conductive aromatic polyester resin tube according to claim 1, wherein the conductive filler is conductive carbon black. 5. The heat shrinkage according to claim 1, wherein the conductive filler is acetylene black, and the average primary particle diameter is 25 to 60 nm and the specific surface area is 300 m ² / g or less. Conductive aromatic polyester resin tube. 6. The heat-shrinkable electrically conductive aromatic polyester resin tube according to claim 1, wherein the aromatic polyester resin is amorphous. 7. The heat-shrinkable conductive aromatic polyester resin tube is 1.2 to 4.0 times the unstretched conductive aromatic aromatic polyester resin tube in the radial direction of the tube, and 1 in the length direction of the tube. The heat-shrinkable conductive aromatic polyester resin tube according to any one of claims 1 to 7, which is obtained by stretching 0.0 to 4.0 times. 8. The heat shrinkage rate when immersed in hot water at 100 ° C. for 30 seconds is 10 to 60% in the radial direction of the tube and 0 to 40% in the longitudinal direction of the tube. The heat-shrinkable conductive aromatic polyester resin tube according to any one of claims. 9. Based on 100 parts by weight of a thermoplastic resin (component A) containing 70% by weight or more of an aromatic polyester resin,
(B) A tubular layer formed from a resin composition containing 0.5 to 50 parts by weight of a conductive filler (component B),
An inorganic material product whose surface is covered with a layer having an inner diameter of 2.5 mm to 295 mm and a wall thickness of 26 μm to 130 μm. 10. The surface-coated inorganic material product according to claim 9, wherein the aromatic polyester resin is formed of an aromatic polyester having ethylene terephthalate units as main repeating units. 11. The surface-coated inorganic material product according to claim 9, wherein the conductive filler is conductive carbon black. 12. The conductive filler is acetylene black, which has an average primary particle diameter of 25 to 60 nm and a non-surface area of 300 m ² / g or less.
An inorganic material product coated with the surface according to any one of 1. 13. The tubular layer is obtained by heat-shrinking the heat-shrinkable electrically conductive aromatic polyester resin tube according to any one of claims 1 to 8. An inorganic material product coated with the surface according to any one of 1. 14. The surface-coated inorganic material product according to claim 9, wherein the inorganic material product is a charging roller, a transfer roller or a developing roller.