JP2005105119A - Heat shrinkable aromatic polyester resin tube with excellent heat shrinkable characteristics - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat shrinkable aromatic polyester resin tube having a small embrittlement and fine opening properties by using an aromatic polyester resin having the glass transition temperature above a specific range and having a specific range of shrinkage rate in the radial direction in the specific range at low temperatures while the fine appearance of a coated product is achieved by reducing wrinkles formed by a coating process. <P>SOLUTION: The thermally shrinkable aromatic polyester resin tube is formed by drawing a resin composition containing mainly a thermoplastic resin (A component) containing ≥70 wt.% of an aromatic polyester resin. The drawn tube has: (1) the glass transition temperature of the aromatic polyester resin of ≥70°C measured by the DSC measurement following JIS K7121 and (2) the shrinkage ratio of ≤10% in the radial direction after immersed in warm water of 65°C for 30 seconds. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a heat-shrinkable aromatic polyester resin tube formed from a resin composition mainly composed of a thermoplastic resin containing 70% by weight or more of an aromatic polyester resin, and use thereof. More specifically, when the glass transition temperature of the aromatic polyester resin is not less than a specific temperature, and the shrinkage ratio in the radial direction of the drawn tube in warm water at 65 ° C. is not more than a specific range, the wrinkle during the coating process is reduced. The present invention relates to a heat-shrinkable aromatic polyester resin tube that does not cause appearance defects and the like, and an inorganic material product that is covered with the tube.

  Conventionally, a heat-shrinkable tube mainly made of polyvinyl chloride has been widely used as a heat-shrinkable tube-like electric insulating material used for coating of aluminum electrolytic capacitors and lithium ion batteries. However, in recent years, the use of polyvinyl chloride due to the problems of heavy metal contamination of lead and cadmium contained in polyvinyl chloride stabilizers, the problem of phthalic acid free used in plasticizers, and the problem of dioxins during combustion. As a substitute for this, a heat-shrinkable tube made of polyester resin or the like is used. However, as a result of changing from a conventional polyvinyl chloride to a heat-shrinkable tube made of polyester resin, there is a problem that the amount of heat at the time of coating is insufficient and the coating is not sufficiently formed. Currently, as a countermeasure, by increasing the temperature of the processing furnace, the conventional production rate is maintained and productivity is maintained, or polybutylene terephthalate resin having a low glass transition temperature is added to polyethylene terephthalate resin (see Patent Document 1). ), Polyethylene terephthalate resin containing a large amount of copolymer components is used (see Patent Document 2).

However, if the coating processability of the heat-shrinkable tube made of polyethylene terephthalate resin is close to that of polyvinyl chloride, there is a problem that wrinkles are likely to occur when coating an aluminum electrolytic capacitor or a lithium ion battery. Accordingly, there has been a demand for a heat-shrinkable tube that does not have the above-described defects and is covered with a capacitor or a lithium ion battery, has a good tube opening property, is less brittle with time, and does not undergo secondary shrinkage.
JP 2002-120288 A JP-A-4-303620

  The present invention is excellent in coating processability when a heat-shrinkable aromatic polyester resin tube is coated on a consumer battery such as an aluminum electrolytic capacitor part or a lithium ion battery, has less brittleness, and has a shrinkage characteristic when coated. Another object of the present invention is to provide a heat-shrinkable polyethylene terephthalate tube having excellent opening properties.

  As a result of intensive studies to achieve the above object, the present inventors have found that the glass transition temperature of the aromatic polyester resin is not less than a specific range and the shrinkage ratio in the radial direction in the low temperature region is in a specific range. By using it, it was found that the appearance at the time of coating was good, the tube was less brittle and the opening was excellent, and the present invention was achieved.

  According to the present invention, the heat-shrinkable tube described in 1) to 9) below and a product using the same are provided.

1) A heat-shrinkable stretched tube formed from a resin composition mainly composed of a thermoplastic resin (component A) containing 70% by weight or more of (A) an aromatic polyester resin, the stretched tube comprising (1) JIS The glass transition temperature of the aromatic polyester resin determined by DSC measurement in accordance with K7121 is 70 ° C. or higher, and (2) the radial shrinkage ratio after being immersed in 65 ° C. warm water for 30 seconds is 10% or lower. A heat-shrinkable aromatic polyester resin tube characterized by that.

2) The heat-shrinkable aromatic polyester according to 1), wherein the heat shrinkage rate when immersed in hot water at 100 ° C. for 30 seconds is 20 to 50% in the radial direction of the tube and 20% or less in the length direction of the tube. Resin tube.

3) 0.04 to 4 parts by weight of (B) inorganic lubricant (component B) and / or 100 parts by weight of the thermoplastic resin (component A) containing 70% by weight or more of the aromatic polyester resin in the resin composition (C) The heat-shrinkable aromatic polyester resin tube according to 1) above, which is a resin composition comprising 0.02 to 4 parts by weight of an organic lubricant (component C).

4) The above-mentioned stretched tube is obtained by stretching an unstretched tube 1.2 to 2.0 times in the radial direction of the tube and 1.0 to 1.5 times in the length direction of the tube. ) Heat-shrinkable aromatic polyester resin tube as described.

5) An inorganic material product whose surface is coated with the heat-shrinkable aromatic polyester resin tube described in any one of 1) to 4) above.

6) The inorganic material product according to 5) above, wherein the inorganic material product is an aluminum electrolytic capacitor.
7) The inorganic material product according to 5) above, wherein the inorganic material product is an electric double layer capacitor.
8) The inorganic material product according to 5) above, wherein the inorganic material product is a lithium ion battery.
9) The inorganic material product according to 5) above, wherein the inorganic material product is a fuel cell.

  The present invention will be described in further detail below.

  The aromatic polyester resin in the present invention (hereinafter sometimes simply referred to as “polyester resin”) is 70 mol% or more of the dicarboxylic acid component of the dicarboxylic acid component and diol component forming the polyester resin, preferably 90 mol% or more, and most preferably 99 mol% or more of the polyester resin is an aromatic dicarboxylic acid.

  Examples of this dicarboxylic acid include terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2,5-dichloroterephthalic acid, 2-methylterephthalic acid, 4,4-stilbene dicarboxylic acid, 4,4-biphenyldicarboxylic acid, orthophthalic acid. Acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, bisbenzoic acid, bis (p-carboxyphenyl) methane, anthracene dicarboxylic acid, 4,4-diphenyl ether dicarboxylic acid, 4,4-diphenoxyethane Examples thereof include dicarboxylic acid, 5-Na sulfoisophthalic acid, and ethylene-bis-p-benzoic acid. These dicarboxylic acids can be used alone or in admixture of two or more.

  In addition to the above aromatic dicarboxylic acid, the polyester resin of the present invention can be copolymerized with an aliphatic dicarboxylic acid component of less than 30 mol%. Specific examples thereof include adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid and the like.

  Examples of the diol component include ethylene glycol, diethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 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, bisphenol A, tetrabromobisphenol A, tetrabromobisphenol A-bis (2-hydroxyethyl ether), and the like. These can be used alone or in admixture of two or more.

  Specific examples of the aromatic polyester resin comprising 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 / Examples thereof include isophthalate copolymer resins and polyethylene / neopentylene terephthalate copolymer resins.

  Among these, polyethylene terephthalate resin, polyethylene naphthalate resin, polyethylene terephthalate / isophthalate copolymer resin, and polyethylene / neopentyl terephthalate copolymer resin are preferable.

  Furthermore, polyethylene terephthalate resin, polyethylene terephthalate / isophthalate copolymer resin, and polyethylene / neopentylene terephthalate copolymer resin are more preferable. The most preferred embodiment is a polyethylene terephthalate resin.

  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, polyethylene / neopentylene terephthalate copolymer resin are used for the purpose of further improving heat resistance while maintaining heat shrink properties. Polyethylene naphthalate resin and polybutylene naphthalate resin can be mixed in an amount of 3 to 30% by weight. Further, for the purpose of improving the heat shrink property at low temperature, 0.1 to 20% by weight of polybutylene terephthalate resin can be mixed with polyethylene terephthalate resin.

  In the present invention, a polyethylene terephthalate resin (hereinafter sometimes abbreviated as “PET resin”) is a resin substantially composed of terephthalic acid as a dicarboxylic acid component and ethylene glycol as a diol component.

  Further, a PET resin obtained by slightly copolymerizing polyethylene glycol as the diol component is preferable. Here, polyethylene glycol is a general term for compounds having ethylene glycol as its polymer component. Therefore, diethylene glycol is also included. The upper limit molecular weight is preferably about 6,000.

  The composition ratio of the polyethylene glycol component is preferably 5% by weight or less, more preferably 3% by weight or less, and still more preferably 2% by weight or less in 100% by weight of the diol component. The lower limit is preferably 0.5% by weight or more, and more preferably 1% by weight or more.

  The introduction of the polyethylene glycol component has the advantage that the mobility of the molecular chain is increased and the entropy elasticity necessary for the heat shrink property can be increased. On the other hand, if too much is included, the heat resistance is lowered and the crystallinity tends to be high. In order to balance these advantages and disadvantages, it is preferable to lower the molecular weight of polyethylene glycol. That is, it is more preferable to introduce components such as diethylene glycol and triethylene glycol. More preferably, diethylene glycol is introduced. It is also preferable to introduce components such as trimethylene glycol and tetramethylene glycol.

  That is, the PET resin suitable as the resin of the present invention is a resin substantially composed of terephthalic acid as the dicarboxylic acid component and ethylene glycol as the diol component. The content of the diethylene glycol component in the PET resin is 100 mol% of the diol component. Among them, 1.0 to 9.0 mol% is preferable, 1.2 to 7.5 mol% is more preferable, and 2.0 to 5.0 mol% is most preferable. In order to control the diethylene glycol component content within the above range, it is also possible to polymerize by adding a small amount of diethylene glycol before polymerization. Further, a small amount of a diol component such as polyethylene glycol or the like, preferably 1 mol% or less, may be copolymerized as long as the present invention is not impaired during polymerization.

  Ratio of terephthalic acid and isophthalic acid of dicarboxylic acid component constituting polyethylene terephthalate / isophthalate copolymer resin (hereinafter sometimes abbreviated as “TA / IA copolymer resin”) which is a preferred example of the resin of the present invention The terephthalic acid is 80 to 99.9 mol%, preferably 85 to 99 mol%, more preferably 90 to 99 mol% when the total dicarboxylic acid component is 100 mol%. Moreover, isophthalic acid is 0.1-20 mol%, Preferably it is 1-15 mol%, More preferably, it is 1-10 mol%.

  In this TA / IA copolymer resin, the aromatic dicarboxylic acid such as naphthalenedicarboxylic acid other than terephthalic acid and isophthalic acid is 10 mol% or less, preferably 5 mol% or less, and the aliphatic such as adipic acid. Although it is possible to copolymerize a dicarboxylic acid in an amount of 5 mol% or less, preferably 3 mol% or less, it is most preferable that the dicarboxylic acid component consists only of terephthalic acid and isophthalic acid.

  Further, ethylene glycol alone is most preferable as the diol component in the TA / IA copolymer resin, but the above diol components such as diethylene glycol other than ethylene glycol can be copolymerized at 10 mol% or less, preferably 5 mol% or less.

  Ethylene glycol and neopentylene glycol as diol components constituting polyethylene / neopentylene terephthalate copolymer resin (hereinafter sometimes abbreviated as “EG / NPG copolymer resin”) which is a preferred example of the resin of the present invention. The amount of ethylene glycol is 90 to 99 mol%, preferably 95 to 99 mol%, more preferably 97 to 99 mol%, based on 100 mol% of all diolic acid components. Moreover, neopentylene glycol is 1-10 mol%, Preferably it is 1-5 mol%, More preferably, it is 1-3 mol%. The diol components such as diethylene glycol other than ethylene glycol and neopentylene glycol can be copolymerized in an amount of 5 mol% or less, preferably 3 mol% or less.

  In this EG / NPG copolymer resin, the aromatic dicarboxylic acid such as naphthalenedicarboxylic acid other than terephthalic acid is 10 mol% or less, preferably 5 mol% or less, and the aliphatic dicarboxylic acid such as adipic acid is contained. Although it is possible to copolymerize 5 mol% or less, preferably 3 mol% or less, it is most preferable that the dicarboxylic acid component is terephthalic acid alone. The aliphatic dicarboxylic acid other than ethylene glycol and neopentylene glycol can be copolymerized in an amount of 5 mol% or less, preferably 3 mol% or less.

  The end group structure of the aromatic polyester resin used in the present invention is not particularly limited, except when the ratio of the hydroxyl group and the carboxyl group in the end group is almost the same, and the ratio of one is large. Also good. Moreover, those terminal groups may be sealed by means such as reacting a compound having reactivity with such terminal groups.

  About the manufacturing method of the aromatic polyester resin used for this invention, a dicarboxylic acid component and the said diol component are superposed | polymerized in the presence of the polycondensation catalyst containing titanium, germanium, antimony, etc. according to a conventional method. The by-product water or lower alcohol is discharged out of the system. For example, germanium-based polymerization catalysts include germanium oxides, hydroxides, halides, alcoholates, phenolates, and the like, and more specifically, germanium dioxide, germanium hydroxide, germanium tetrachloride, and tetramethoxygermanium. Illustrated. Examples of the antimony catalyst include antimony trioxide.

  Further, in the present invention, compounds such as manganese, zinc, calcium, magnesium, etc., which are used in a transesterification reaction that is a prior stage of a conventionally known polycondensation, can be used in combination, and phosphoric acid or phosphorous after completion of the transesterification reaction. Such a catalyst can be deactivated and polycondensed with an acid compound or the like.

  The production method of the aromatic polyester resin can be either a batch method or a continuous polymerization method.

  The intrinsic viscosity [η] of the aromatic polyester resin is preferably 0.4 to 1.5, more preferably 0.5 to 1.0, in the intrinsic viscosity measured at 35 ° C. using o-chlorophenol as a solvent, 0.55-0.95 is more preferable, and 0.6-0.9 is particularly preferable. If [η] is less than 0.4, the mechanical properties, breaking strength, and elongation of the tube are low, and if it exceeds 1.5, the melt processability of the tube is inferior.

  Therefore, as a preferred embodiment of the polyester resin in the present invention, η measured at 35 ° C. using o-chlorophenol as a solvent is 0.5 to 1.0, and terephthalic acid as a dicarboxylic acid component and ethylene as a diol component Particularly preferred is a resin comprising glycol and containing 1.0 to 9.0 mol% of diethylene glycol as the diol component in 100 mol% of the diol component.

  The polyester resin constituting the heat-shrinkable tube of the present invention may be one type or two or more types, and a recycled polyester resin may be used. For example, a TA / IA copolymer resin can be used alone or mixed with a PET resin, and isophthalic acid in 100 mol% of the total dicarboxylic acid component in the mixed resin of the TA / IA copolymer resin and the PET resin. Can be used by blending such that 0.1 to 20 mol%, preferably 0.1 to 15 mol%, more preferably 0.1 to 10 mol%.

  The copolymerization may be a block copolymer or a random copolymer. For example, the TA / IA copolymer resin may be a block copolymer substantially composed of a polyethylene terephthalate chain and a polyethylene isophthalate chain, or a random copolymer of ethylene terephthalate and ethylene isophthalate.

  The polyester resin is preferably 70% by weight or more, more preferably 80% by weight or more in 100% by weight of the thermoplastic resin (A).

The thermoplastic resin of the present invention can contain a thermoplastic resin other than the polyester resin in 30% by weight or less, preferably 20% by weight or less, out of 100% by weight. Other thermoplastic resins other than the polyester resin include polysulfone resin, polyether ether ketone resin, polyphenylene sulfide resin, polyphenylene ether resin, polyethylene resin, polyolefin resin such as polypropylene resin, polystyrene resin, ABS resin, AS resin, Styrenic resin such as MBS resin, polycarbonate resin, polyarylate resin, polyamide resin, acrylic resin, and various thermoplastic elastomers (for example, styrene, olefin, urethane, polyester, polyamide, 1,2-polybutadiene) Vinyl chloride type, fluorine type [fluoro rubber], ionomer resin, chlorinated polyethylene, silicone type, etc.). Further, there is a composite rubber of acrylic rubber and silicon rubber using IPN (Interpenetrating Polymer Networks) technology, for example, Mitsubishi Rayon Co., Ltd. trade name Metabrene S-2001. One or more types of thermoplastic resins other than these polyester resins can be used.
Among these thermoplastic resins other than the polyester resin, a thermoplastic polyester elastomer resin having good compatibility with the polyester resin is preferable from the viewpoint of improving the hot water resistance.

  This thermoplastic polyester elastomer resin (hereinafter sometimes abbreviated as “TPEE resin”) uses an aromatic polyester having a high melting point and high crystallinity for the hard segment, and amorphous polyester or amorphous for the soft segment. Resin using polyether. The former is a polyester ester resin and the latter is a polyether ester resin.

  The latter polyether ester resin has a hard segment of 5 to 95 wt% and a soft segment of 5 to 95 wt% when the polyether ester resin is 100 wt%, and its intrinsic viscosity is in the range of 0.4 to 2.0. It is.

  As the aromatic polyester of the hard segment of the polyether ester resin, the dicarboxylic acid and the diol component constituting the aromatic polyester resin can be used, and the melting point of this segment is preferably 100 ° C. or higher.

  Specifically, polybutylene terephthalate or polybutylene naphthalate substantially consisting of 1,4-butanediol and terephthalic acid or naphthalenedicarboxylic acid is preferred. Such polybutylene terephthalate or polybutylene naphthalate contains other diols other than 1,4-butanediol, such as ethylene glycol, diethylene glycol, triethylene glycol, neopentylene glycol, cyclohexane dimethanol, etc. 5 mol% or less can be copolymerized, and other dicarboxylic acids other than terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, etc., preferably isophthalic acid is copolymerized to 100 mol% or less and 10 mol% or less of the total dicarboxylic acid component. be able to. Most preferred 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. Representative examples of such polyether glycols include polyether glycols such as polypropylene glycol, polytrimethylene glycol and polytetramethylene glycol, or copolyethylene-propylene glycol, copolyethylene-tetramethylene glycol [provided that the ethylene oxide unit is a copolyol. Comprising 50% by weight or less of ether glycol], copolytetramethylene-1,2-cyclohexylenedimethylene glycol [wherein 1,2-cyclohexylenedimethylene oxide units comprise 1 to 20 mol% of copolyether glycol. ] Copolyether glycol. Of these, polytetramethylene glycol is preferred.

  The polyether ester resin of the present invention has a hard segment of 5 to 95% by weight and a soft segment of 5 to 95% by weight when the polyether ester resin is 100% by weight. A range of zero.

  As the aromatic polyester of the hard segment of the polyether ester resin, the dicarboxylic acid and diol component constituting the above-described aromatic polyester resin can be used, and the melting point of this segment is preferably 100 ° C. or higher.

  Specifically, polybutylene terephthalate substantially consisting of 1,4-butanediol and terephthalic acid is preferable. Such polybutylene terephthalate contains other diols other than 1,4-butanediol, such as ethylene glycol, diethylene glycol, triethylene glycol, neopentylene glycol, cyclohexane dimethanol, and the like in an amount of 5 mol% or less in 100 mol% of all diol components. The dicarboxylic acid other than terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, etc., preferably isophthalic acid, can be copolymerized with 100 mol% or less and 10 mol% or less of all dicarboxylic acid components. Most preferred is polybutylene terephthalate consisting only of 1,4-butanediol and terephthalic acid.

  The soft segment of the polyether ester resin is polycaprolactone, an aliphatic polyester (for example, polyethylene adipate) from the aliphatic dicarboxylic acid and an aliphatic diol, and the main component of the dicarboxylic acid component is an aromatic dicarboxylic acid, Polyester ether with a diol component mainly composed of a polyether glycol in which the alkylene part is alkylene having 3 to 12 carbon atoms or cycloalkylene having 4 to 10 carbon atoms (hereinafter abbreviated as aromatic polyester ether). There is.) Of these, aromatic polyester ethers are preferred.

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

  The TPEE resin is preferably 0.1 to 10% by weight, more preferably 0.5 to 5% by weight, in 100% by weight of component A.

  The resin composition of the present invention provides an inorganic lubricant (component B) and / or an organic lubricant (component C) in order to impart slipperiness and to obtain a good opening property of the tube and good finish characteristics when coated. It is preferable to include. More preferably, it contains a specific amount of a combination of an inorganic lubricant and an organic lubricant.

  Examples of the inorganic lubricant of component B of the present invention include inorganic inactive external particles such as kaolin, clay, calcium carbonate, silicon oxide, calcium terephthalate, aluminum oxide, titanium oxide, calcium phosphate, and lithium fluoride. The average particle diameter of the inorganic inert external particles is 0.01 to 10 μm, preferably 0.1 to 10 μm, and more preferably 4 to 10 μm. Here, the average particle diameter of the inorganic inactive external particles is a particle diameter when the cumulative weight distribution of the weight distribution measured using a laser diffraction method (SALD-1100 manufactured by Shimadzu Corporation) is 50%. As the particle size distribution, it is very preferable to contain large-sized inorganic inactive external particles having a particle size of 4 to 30 μm. In such a range, even if the tube is thin, no defects are generated in the tube, and good openability can be achieved. The content of the large particle size inorganic inert external particles is preferably 2 to 80% by weight, more preferably 10 to 70% by weight, and most preferably 20 to 60% by weight in 100% by weight of all inorganic inert external particles. is there.

  The effect of containing large-diameter inorganic inert external particles is particularly remarkable in a low-stretch ratio tube where protrusion of large-diameter inorganic inert external particles due to stretching is unlikely to occur. In addition, since these tubes are expanded by applying an internal pressure to the unstretched tube and the diameter is regulated by the stretched tube, the protrusions of the large-size inorganic inactive external particles are reduced on the outer surface in contact with the stretched tube, and the printability is improved. . On the other hand, the inner surface of the tube that does not come into contact with the drawn tube is likely to develop protrusions of large-particle-size inorganic inactive external particles, so that the openability is improved.

  As the organic lubricant of component C of the present invention, hydrocarbon lubricants such as paraffin and polyethylene wax, higher fatty acid lubricants such as stearic acid, metal soap lubricants such as calcium stearate, ester lubricants such as montanic acid wax, benzoguanamine, Examples thereof include organic fine particles such as a crosslinked acrylic resin mainly composed of polymethyl methacrylate. In particular, an organic lubricant that provides a synergistic effect with an inorganic lubricant is most suitable for improving external lubricity and having good compatibility with a resin. In addition to this, it is necessary to satisfy conditions such as heat stability during extrusion, and montanic acid wax is particularly preferable for a resin composition containing 70% by weight or more of a polyester resin.

  The montanic acid wax is a fossil wax montan wax mainly containing a fatty acid having 21 to 34 carbon atoms and an aliphatic alcohol obtained by solvent extraction of lignite, and a wax obtained by esterifying or partially saponifying the montan wax. . Specifically, Hoechst WAX S (manufactured by Hoechst) obtained by oxidizing montan wax, Hoechst WAX E (manufactured by Hoechst), which is a montanic acid diester obtained by esterifying montan wax with ethylene glycol, and montan wax was esterified with glycerin. Montalnic acid diester Hostalb WE40 (manufactured by Hoechst), Montan wax is partially esterified with butylene glycol, and the remainder is partially saponified montanic acid ester Hoechst WAX OP (manufactured by Hoechst) Among them, Hoechst WAX E and Hostalb WE40 are preferable.

  The added amount of the inorganic lubricant (component B) and the organic lubricant (component C) is preferably 0.02 to 4 parts by weight, more preferably 0.1 to 2.5 parts by weight, per 100 parts by weight of the component A. A more preferred embodiment is a resin composition comprising 0.05 to 1 part by weight of B component and 0.05 to 1 part by weight of C component with respect to 100 parts by weight of A component.

  By combining an organic lubricant and an inorganic lubricant, effective particle protrusion formation and surface lubricity can be improved without problems such as a decrease in heat resistance, and the openability can be improved. Furthermore, when the tube is cut, covered, and contracted by an automatic mounting machine, the close contact of the cut portion is reduced, and the insertability of the coated body into the tube is improved, so that stable processing can be performed.

  Also, such heat-shrinkable tubes are often folded as tapes and wound up on reels before being shipped as products. The tube may stick to each other and become difficult to peel off, but this resin composition can also improve such problems.

  As a method for producing the tube of the present invention, a method in which an unstretched tube is extruded using a ring die and then stretched to obtain a heat-shrinkable tube is most preferred. In addition, there are a method in which a film extruded and stretched using a T die or an I die is bonded by fusion, welding, or adhesion to form a tube, and a method in which the tube or film is bonded in a spiral shape to form a tube. .

  Here, the method of extruding an unstretched tube using a ring die and then stretching it into a heat-shrinkable tube will be described in more detail. The resin composition composed of the aromatic polyester resin described above is heated and melted to a temperature equal to or higher than the melting point by a melt extruder, continuously extruded from a ring die, and then forcibly cooled and molded into an unstretched tube. As a means for forced cooling, a method of immersing in low-temperature water, a method using cooling air, or the like can be used. Of these, the method of immersing in low-temperature water is effective because of its high cooling efficiency. The unstretched tube may be continuously supplied to the next stretching step, or after being wound up into a roll, the unstretched roll may be 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 pressurized with compressed gas from the inside of the tube and biaxially stretched. The stretching method is not particularly limited, but, for example, it is sent out from one end of an unstretched tube at a constant speed while applying pressure by a compressed gas to the inside of the tube, and then preheated with hot water or an infrared heater, etc. Biaxial stretching is performed 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 on the drawing pipe. It cools after extending | stretching, and is taken up and wound up as an extending | stretching tube, hold | maintaining extending | stretching pressure by pinching with a pair of nip rolls. Stretching may be performed in any order in the length direction or the radial direction, but is preferably performed simultaneously.

  The stretching ratio in the length direction is determined by the ratio of the feed speed of the unstretched tube and the nip roll speed after stretching, and the stretching ratio in the radial direction is determined by the ratio of the unstretched outer diameter to the stretched tube outer diameter. As another stretching and pressurizing method, a method of maintaining the internal pressure of the compressed gas in which both the unstretched tube feed side and the stretched tube take-up side are sandwiched and sealed between nip rolls can be employed.

  The stretching conditions vary depending on the properties of the polymer used and the heat shrinkability of the target tube, but the stretching temperature is usually above the glass transition temperature to 105 ° C, preferably 70 to 100 ° C.

  The heat-shrinkable aromatic polyester tube of the present invention is obtained by stretching an unstretched tube 1.2 to 2.0 times in its radial direction and 1.0 to 1.5 times in its length direction. Is preferred. Furthermore, the draw ratio in the radial direction of the tube is preferably 1.3 to 1.9 times, and more preferably 1.4 to 1.8 times. The draw ratio in the length direction of the tube is preferably 1.02 to 1.5 times, and more preferably 1.02 to 1.3 times.

  If the draw ratio in the radial direction of the tube is less than 1.2 times, a sufficient amount of shrinkage may not be obtained. On the other hand, if it exceeds twice, the heat resistance is lowered, the tube swells at a high temperature, and secondary contraction tends to occur. Further, it is difficult to obtain a good appearance at both ends when coated on an aluminum electrolytic capacitor or a battery. Also, it is difficult to control the draw ratio in the length direction of the tube.

  When the draw ratio in the length direction of the tube exceeds 1.5 times, the amount of shrinkage in the length direction becomes large, making it difficult to align and difficult to stably coat various products. Yield may decrease.

  In the heat-shrinkable tube of the present invention, the glass transition temperature of the aromatic polyester resin is 70 ° C. or higher, preferably 72 to 85 ° C., and the heat shrinkage rate when immersed in warm water of 65 ° C. for 30 seconds is It is 10% or less, preferably 1 to 9% in the radial direction. Such a shrinkage rate range can provide good coverage to the electronic parts, batteries, and the like to be coated. That is, when the electronic component and battery are covered with a hot stove or the like, if the shrinkage rate in the radial direction under the above conditions is higher than 10%, the tube shrinks considerably in the radial direction without increasing the surface temperature of the covering. For this reason, air remains between the cover and the tube, and the body portion is wrinkled, and the appearance of both ends of the covered portion is wavy or wrinkled.

  A heat-shrinkable tube having a heat shrinkage rate of 20 to 50% in the tube radial direction and 20% or less in the tube length direction when immersed in hot water at 100 ° C. for 30 seconds is suitable for the present invention. As an embodiment. This range of shrinkage ratio provides both good coating and heat resistance for the electronic parts and batteries to be coated. As a more preferable range, the heat shrinkage rate is 30 to 50% in the radial direction of the tube and 1 to 15% in the length direction of the tube. Although these dimensions are not particularly limited, for example, a heat shrinkable tube having an inner diameter of 3 to 100 mm and a wall thickness of 25 to 500 μm.

  The resin composition of the present invention may be used by previously mixing the above components with a mixer such as a tumbler, V-type blender, nauter mixer, Banbury mixer, kneading roll, extruder, etc. Each component weighed may be directly supplied to the supply port of the extruder to be extruded, or the component weighed separately may be supplied to each supply port of the extruder having two or more supply ports.

  Furthermore, you may add the various additive and inorganic filler of the quantity which the effect expresses in the range which does not impair the objective of this invention. Various additives include 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 aids (sodium antimonate, antimony trioxide, etc.), anti-dripping agents (eg, polytetrafluoroethylene having fibril-forming ability), antioxidants (eg, hindered phenol compounds), UV absorbers, mold release Agents, lubricants, colorants and the like. Examples of the inorganic filler include glass beads, talc, and mica.

  In order to avoid hydrolysis of the polyester resin, the resin composition of the present invention is previously dried so that the water content is 0.1% by weight or less, preferably 0.05% by weight or less. For example, drying is performed under conditions such as 170 ° C. for 3 hours, 150 ° C. for 12 hours, and vacuum at 120 ° C. for 24 hours.

  Thus, according to the present invention, a product in which the surface of various inorganic material products is coated using the heat-shrinkable aromatic polyester resin tube is also provided. As a product to be coated on the surface, any product that can utilize the characteristics (insulation, heat resistance, chemical resistance, mechanical properties such as high elastic modulus) of the aromatic polyester resin as the main component may be used. Examples include metal material products and glass products. Specifically, the metal material products include aluminum electrolytic capacitors (lead type, chip type, substrate self-supporting type, screw terminal type), electric wires (round wire, square wire), electric double layer capacitor, consumer primary, 2 Examples of secondary batteries include primary, secondary batteries, fuel cells, steel pipes, roller parts, or electrical devices such as various lithium ion batteries and nickel metal hydride batteries (tubular and rectangular), and examples of such electrical devices include motor coils. Including end, transformer, lead wire, and the whole small motor can be covered. Further, examples of glass products include light bulbs and fluorescent lamps, and in particular, they can also be used as fluorescent lamp-coated tubes for facsimiles and image scanners.

  Table 1 shows a heat-shrinkable aromatic polyester resin tube comprising a thermoplastic resin containing 70% by weight or more of the aromatic polyester resin of the present invention and a resin composition added with an inorganic lubricant and / or an organic lubricant as required. As apparent from FIG. 4, the glass transition temperature of the aromatic polyester resin is 70 ° C. or higher, and the shrinkage ratio in the radial direction after being immersed in 65 ° C. hot water for 30 seconds is 10% or less, so that the coating appearance at the time of coating is achieved. In addition to being excellent in openability, the stretched tube is excellent in that it is less brittle with time even when stored at a high temperature of 40 ° C. for a long time. Furthermore, a heat-shrinkable aromatic polyester resin tube that can make use of the combustion resistance, electrical characteristics, and chemical resistance of the resin composition and can be used as a coating material or a protective material is provided. In addition, an industrially advantageous manufacturing method of the tube and an inorganic material product in which various products are coated or protected using the heat shrinkability are provided.

  Therefore, it is useful not only for capacitors used in conventional vinyl chloride heat-shrinkable tubes and polyethylene terephthalate resin tubes, but also for applications such as protective coatings for fluorescent lamps and insulation coatings for lithium ion batteries.

  Hereinafter, the present invention will be described in more detail with reference to examples. In addition, the typical physical property in an Example was measured with the following method.

(1) Glass transition temperature Using a differential scanning calorimetry (DSC) apparatus, the glass transition temperature was measured at 20 ° C. per minute according to JIS K7121, and the glass transition temperature was measured.

(2) Heat Shrinkage The length before and after the heat shrinkable tube having a length of 10 cm was immersed in hot water at 65 ° C. and 100 ° C. for 30 seconds and the outer diameter were measured with a digital caliper and calculated from the following formula (1). . Five samples were measured and the average value was calculated.

Thermal contraction rate (%) = [[(length before hot water immersion) − (length after hot water immersion)]]
/ (Length before immersion in hot water)]] × 100 (1)

(3) Coated appearance Insert an aluminum electrolytic capacitor for Φ18 into the heat-shrinkable tube, and visually evaluate the coated state of the tube after coating at 230 ° C. for 20 seconds using a hot stove.

○: The coating appearance is good.
×: Wrinkles remain on the body or part of the edge is standing,
The coating appearance is not good.

(4) Opening property After crimping with a roll so that air does not remain on the inner surface of the heat-shrinkable tube, the wound tube was bent in parallel with the length direction and evaluated as follows.

○: The mouth opens just by being bent once, and the opening is good. Δ: The mouth is opened twice. ×: Even if folded back three times or more, the mouth does not open and the opening is poor.

(5) Embrittlement with time After the heat-shrinkable tube was left in a dryer at 40 ° C. for 10 weeks, the breaking elongation of the tube in the length direction was measured. Further, the elongation at break in the length direction of the stretched tube before the heat treatment was also measured. The breaking elongation was measured at a tensile speed of 10 mm / min by punching a test piece in parallel with the length direction using ASTM D638 type V dumbbell.

[Examples 1-8 and Comparative Examples 1-3]
The unstretched tube obtained by melting the resin composition shown in Table 1 with an extruder set at a cylinder temperature of 270 ° C., extruding through a ring die, immersing in water, and cooling and solidifying it as it is in 98 ° C. warm water, inside diameter 18.8 mmφ The drawn tube was used, an internal pressure was applied to the tube with 0.5 kg / cm ² of compressed air, and the tube was drawn and cooled with water under the conditions shown in Table 1 to obtain drawn heat-shrinkable tubes shown in Table 1. The shape and characteristics of the obtained heat-shrinkable tube are shown in Table 1.

Each abbreviation in Table 1 means the following.
(A-1) Aromatic polyester resin PET-1: The acid component is 100 mol% terephthalic acid, the diol component is 96.6 mol% ethylene glycol, and 3.4 mol% diethylene glycol, [η] = 0.85. Polyethylene terephthalate resin PET-2: Acid component is 98.5 mol% terephthalic acid, isophthalic acid 1.5 mol%, diol component is ethylene glycol 98 mol%, diethylene glycol 2 mol%, and [η] = 0. 68 polyethylene terephthalate resin. Product name YPR clear pellet made by Yono PET Bottle Recycle Co., Ltd. PEN: Polyethylene naphthalate resin with [η] = 0.6 PBT: Polybutylene terephthalate resin with [η] = 0.7

(Other than component A)
PET-3: Neopentyl copolymerized polyethylene terephthalate resin in which the acid component is 100 mol% terephthalic acid, the diol component is 88 mol% ethylene glycol, and 12 mol% neopentyl glycol, and [η] = 0.71.

(A-2) Polyester elastomer resin TPE-1: Polyether ester resin in which the hard segment is polybutylene terephthalate and the soft segment is polytetramethylene glycol.

(B) Inorganic lubricant Inorganic lubricant: 13.4% by weight of large-size inert external particles having an average particle size of 4.8 μm and a particle size of 4.0-5.3 μm, and 5.3-7.5 μm of 16.2 Contains 15.0% by weight, 7.5-11.0 μm, 10.4% by weight of 11-16 μm, 2.6% by weight of 16-22 μm, and 0.2% by weight of 22-30 μm. Kaolin. (Contains 57.8% by weight of 4-30 μm large-sized inert external particles out of 100% by weight of all inert external particles)

(C) Organic lubricant: Organic lubricant: Hoechst WAX E manufactured by Hoechst, which is a montanic acid diester obtained by esterifying montanic acid with ethylene glycol

Claims (9)

(A) A heat-shrinkable stretched tube formed from a resin composition mainly composed of a thermoplastic resin (component A) containing 70% by weight or more of an aromatic polyester resin, the stretched tube according to (1) JIS K7121 The glass transition temperature of the aromatic polyester resin obtained by the DSC measurement in conformity is 70 ° C. or higher, and (2) the radial shrinkage ratio after being immersed in 65 ° C. warm water for 30 seconds is 10% or lower. Characteristic heat-shrinkable aromatic polyester resin tube. The heat-shrinkable aromatic polyester resin tube according to claim 1, wherein the heat-shrinkage rate when immersed in hot water at 100 ° C for 30 seconds is 20 to 50% in the radial direction of the tube and 20% or less in the length direction of the tube. . The resin composition is 0.02 to 4 parts by weight of (B) inorganic lubricant (component B) and / or (C) with respect to 100 parts by weight of the thermoplastic resin (component A) containing 70% by weight or more of the aromatic polyester resin. 2. The heat-shrinkable aromatic polyester resin tube according to claim 1, which is a resin composition comprising 0.02 to 4 parts by weight of an organic lubricant (component C). The stretched tube is obtained by stretching an unstretched tube 1.2 to 2.0 times in the radial direction of the tube and 1.0 to 1.5 times in the length direction of the tube. Heat shrinkable aromatic polyester resin tube. The inorganic material product by which the surface was coat | covered using the heat-shrinkable aromatic polyester resin tube of any one of Claims 1-4. The inorganic material product according to claim 5, wherein the inorganic material product is an aluminum electrolytic capacitor. The inorganic material product according to claim 5, wherein the inorganic material product is an electric double layer capacitor. The inorganic material product according to claim 5, wherein the inorganic material product is a lithium ion battery. The inorganic material product according to claim 5, wherein the inorganic material product is a fuel cell.