JP2002264215A - Heat shrinkable polyethylene terephthalate tube for lithium ion battery coating - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To reduce the embrittlement of a tube before coating on a lithium-ion battery, have good cutting properties, and have excellent shrinkage characteristics and opening properties when coating on a lithium-ion battery. It is an object of the present invention to provide a heat-shrinkable polyethylene terephthalate tube for coating a lithium ion battery having excellent heat resistance and impact resistance after coating. SOLUTION: (A) A diethylene glycol component is used for 1.
A tube formed of a resin composition mainly composed of a thermoplastic resin (component (A)) containing 70% by weight or more of a polyethylene terephthalate resin containing 0 to 9.0% by mole, and 30% of hot water at 100 ° C. of the tube. A heat-shrinkable polyethylene terephthalate tube for coating a lithium ion battery, wherein the heat-shrinkage ratio when immersed for 2 seconds is 20 to 50% in the radial direction of the tube and 0 to 20% in the length direction of the tube.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a heat-shrinkable resin for lithium-ion battery coating formed from a resin composition mainly composed of a thermoplastic resin containing 70% by weight or more of a polyethylene terephthalate resin for use in lithium-ion battery coating applications. It relates to a polyethylene terephthalate tube. More specifically, a stretched tube obtained by stretching an unstretched tube using a polyethylene terephthalate resin in which a diethylene glycol component is in a specific range, wherein the heat shrinkage of the stretched tube is in a specific value range. The present invention relates to a heat-shrinkable polyethylene terephthalate tube for coating a lithium ion battery. Furthermore, when coated on electronic components, etc., it is a tube with excellent cutting properties, and has excellent heat resistance and shock resistance, which is excellent in shrinkage characteristics and opening properties, and can maintain a good coating state. Heat-shrinkable polyethylene terephthalate tube.

[0002]

2. Description of the Related Art Conventionally, general-purpose heat-shrinkable tubular electric insulating materials for lithium ion batteries include conventional polyvinyl chloride tubes and polyethylene terephthalate (P).
Heat-shrinkable tubes such as ET) tubes are known.

[0003] However, vinyl chloride tubes are inexpensive but have insufficient heat resistance. If they are coated with a lithium ion battery or the like and then subjected to a high-temperature treatment, they may cause secondary shrinkage and shoulder slippage. Also, it has been pointed out that in the case of burning and discarding, if a special incinerator is not used, the incinerator is likely to be damaged and harmful substances are easily generated, so that management at the time of disposal requires labor. From these aspects, polyethylene terephthalate (PET) tubes have been used.

In general, polyethylene terephthalate resin is produced using terephthalic acid and its derivatives as dicarboxylic acid components and ethylene glycol and its derivatives as diol components. Regarding the production method, in the presence of a heavy catalyst containing titanium, germanium, antimony, manganese, etc., the above-mentioned raw materials are polymerized while being heated according to a conventional method, and water or excess ethylene glycol is discharged out of the system. It is performed by By the way, diethylene glycol by-produced during the polymerization of polyethylene terephthalate resin is taken into the polymer structure because it has the same reactivity as ethylene glycol. Therefore,
In polyethylene terephthalate resins used for fibers and films, efforts have been made to reduce the content of diethylene glycol as the diethylene glycol contained therein decreases the thermal stability of the polyethylene terephthalate resin. For example, the content of diethylene glycol produced during the production of polyethylene terephthalate resin is as follows.
No. 267 (1967), when a polyethylene terephthalate resin is synthesized by polycondensation of bishydroxyethyl terephthalate using various metal compounds as catalysts, the amount of generated diethylene glycol is 1.4 to 2
0.84 mol%. In Japanese Patent Publication No. 47-51235, the content of diethylene glycol by-produced is reduced to 0.6 mol%.

The heat shrinkable tube for coating a lithium ion battery is mainly required to have the following characteristics. First, the heat shrinkable tube has good coating processability.
Second, the machinability of the heat-shrinkable tube is good. In recent years, in order to produce PCs and mobile phones overseas, many companies also procure lithium ion batteries overseas, and it is necessary to export heat-shrinkable tubing from Japan to cover lithium-ion batteries with heat-shrinkable tubing. More. For example, when exported to a tropical region such as Southeast Asia, it is often stored at a high temperature of 40 ° C. for a long time. In this case, if the heat-shrinkable tube becomes brittle with time, there is a possibility that a defect such as cracking of the tube at the time of opening and coating may occur. Therefore, the third problem is that the heat-shrinkable tube does not become brittle with time even in such a case. Fourth, the heat resistance of the heat-shrinkable tube is good. That is, when performing a drop test by covering a heat-shrinkable tube on a lithium-ion battery,
It is required at least that the insulating plate does not come out even if the tube cracks.

In a heat-shrinkable tube made of a polyester resin, Japanese Patent Application Laid-Open No.
No. 224723 discloses that the crystallinity of a tube is 4 to 4.
Heat shrinkable polyester tubes that are 20% have been proposed. To improve the second characteristic, Japanese Patent Application Laid-Open No. Hei 4-303620 proposes a method for producing a copolymerized polyester tube containing fine particles and a heat-shrinkable polyester tube having specific characteristics.

However, in the tube proposed above, if the tube is exposed to a condition of 40 ° C. for a long time, the elongation of the tube is greatly reduced and the tube becomes brittle, so that cracks occur when the tube is opened or covered. Might be. Further, since the opening property of the polyester tube is much lower than that of the polyvinyl chloride tube, an inorganic and / or organic lubricant is contained as a method for improving the opening property. However, the wear of the blade that cuts the tube is severe due to the influence,
There is a possibility that a defect in which the cut surface is jagged may occur.
Further, in a conventionally used heat-shrinkable polyester tube obtained by stretching at a high magnification, swelling does not occur, but secondary shrinkage occurs, and sufficient coating is not performed. Therefore, there has been a demand for a heat-shrinkable tube which is coated on a lithium ion battery without the above-mentioned defects, has good heat resistance and impact resistance, and does not cause secondary shrinkage.

[0008]

DISCLOSURE OF THE INVENTION The present invention provides a heat-shrinkable polyethylene terephthalate tube which has less embrittlement before coating the tube on a lithium ion battery, has good cutting properties, and has shrinkage characteristics and openability upon coating. It is an object of the present invention to provide a heat-shrinkable polyethylene terephthalate tube for coating a lithium ion battery, which is excellent in heat resistance and impact resistance.

As a result of intensive studies to achieve the above object, the present inventor has found that by using a polyethylene terephthalate resin in which the content of diethylene glycol as a by-product is in a specific range, the polyethylene terephthalate resin before coating on a lithium ion battery can be obtained. Less brittleness of the tube, less defective finish at the end after cutting the tube, and excellent heat resistance and impact resistance ensure that the tube does not crack, swell, and lose its shoulder due to secondary shrinkage. Heading, the present invention has been reached.

That is, while efforts have been made to reduce the amount of diethylene glycol contained in the polyethylene terephthalate resin used in the field of fibers and films, the polyethylene terephthalate resin of the present invention achieves the object of the invention. Therefore, the finding that it is necessary to contain a predetermined amount of the diethylene glycol component is completely incalculable than the conventional finding.

[0011]

According to the present invention, there is provided a resin mainly composed of (A) a thermoplastic resin (component A) containing not less than 70% by weight of a polyethylene terephthalate resin containing 1.0 to 9.0 mol% of a diethylene glycol component. A tube formed from the composition, and 100% of the tube;
The heat shrinkage when immersed in warm water of 30 ° C. for 30 seconds is 20 to 50% in the radial direction of the tube, and 0 to 20 in the length direction of the tube.
% Of the heat-shrinkable polyethylene terephthalate tube for coating a lithium ion battery.

Further, the present invention preferably provides a polyethylene terephthalate resin (A-1 component) containing from 1.0 to 9.0 mol% of the (A-1) diethylene glycol component.
9 wt% and (A-2) 1 to 30 wt% of a polyethylene naphthalate resin (A-2 component) and / or (A-
3) Polyester elastomer (A-3 component) 1-3
The present invention relates to a heat-shrinkable polyethylene terephthalate tube for coating a lithium ion battery which is 0% by weight.

Further, the present invention preferably provides a resin composition comprising A
(B) inorganic lubricant (component B) based on 100 parts by weight of component
0.02 to 4 parts by weight and / or (C) an organic lubricant (C
Component) The present invention relates to a heat-shrinkable polyethylene terephthalate tube for coating a lithium ion battery, comprising 0.02 to 4 parts by weight.

Further, in the present invention, preferably, the unstretched tube is stretched 1.2 to 3.0 times in the radial direction of the tube and 1.0 to 2.0 times in the length direction of the tube. It relates to the obtained heat-shrinkable polyethylene terephthalate tube for coating a lithium ion battery.

In the present invention, more preferably, the resin composition comprises 0.05 to 1 parts by weight of (B) an inorganic lubricant (Component B) and (C) an organic lubricant (Component C) based on 100 parts by weight of Component A. 1.) A heat-shrinkable polyethylene terephthalate tube for coating a lithium ion battery comprising 0.05 to 1 part by weight.

The details of the present invention will be described below. still,
The term “mainly” used in the present invention means that the resin composition is 100% by weight.
50% by weight or more, particularly 92% by weight or more.

The polyethylene terephthalate resin (A-1 component) referred to in the present invention may be produced using terephthalic acid as a dicarboxylic acid component and ethylene glycol as a diol component. It was done. The content of the diethylene glycol component in this PET resin was 100 mol% of the diol component.
In the formula, 1.0 to 9.0 mol%, preferably 1.2 to 7.5 mol%, more preferably 2.0 to 5.0 mol%,
3.0-5.0 mol% is more preferable. Further, in order to control the content of the diethylene glycol component within the above range, it is also possible to add a small amount of diethylene glycol in advance of the polymerization before the polymerization. Further, a small amount, preferably 1 mol% or less of a diol component such as polyethylene glycol may be copolymerized within the range not impairing the present invention during polymerization.

If the content of the diethylene glycol component in the PET resin is less than 1.0% by mole in 100% by mole of the diol component, the shrinkage at low temperatures is insufficient, so that the productivity during coating decreases, and The cutting surface tends to be jagged after coating due to poor cutting during machining due to poor cutting. On the other hand, if the content exceeds 9.0 mol%, the intrinsic viscosity of the PET resin tends to decrease during extrusion production, so that the mechanical properties, breaking strength, and elongation of the tube tend to decrease.

The structure of the terminal group of the polyethylene terephthalate resin used in the present invention is not particularly limited, and is not limited to the case where the ratio of the hydroxyl group and the carboxyl group in the terminal group is almost the same, but when one of the ratios is large. There may be. Further, the terminal groups may be blocked by reacting a compound having reactivity with such terminal groups.

The method for producing the polyethylene terephthalate resin used in the present invention is a conventional method in which a dicarboxylic acid component and the diol component are heated with heating in the presence of a polycondensation catalyst containing titanium, germanium, antimony and the like. Is carried out by discharging water or lower alcohol as a by-product to the outside of the system. For example, germanium-based polymerization catalysts, germanium oxide,
Hydroxides, halides, alcoholates, phenolates and the like can be exemplified, and more specifically, germanium dioxide,
Examples thereof include germanium hydroxide, germanium tetrachloride, tetramethoxygermanium, and antimony trioxide.

In the present invention, compounds such as manganese, zinc, calcium, and magnesium used in a transesterification reaction which is a prior step of a conventionally known polycondensation can be used together. Alternatively, it is possible to deactivate such a catalyst with a phosphorous acid compound or the like to perform polycondensation.

The method for producing the polyethylene terephthalate resin can be any of a batch method and a continuous polymerization method.

The intrinsic viscosity of the PET resin is preferably from 0.4 to 1.5, more preferably from 0.5 to 1.0, more preferably from 0.5 to 1.0, as measured at 35 ° C. using o-chlorophenol as a solvent. 55 to 0.95 is more preferable, and 0.
6 to 0.9 is particularly preferred. If the intrinsic viscosity is less than 0.4, the mechanical properties, rupture strength and elongation of the tube will be low, and if it exceeds 1.5, the melt processability of the tube will be poor, which is not preferable.

The above PET resin may be one kind,
Also, two or more kinds may be mixed.

Accordingly, a preferred embodiment of the PET resin in the present invention is that terephthalic acid is used as a substantially dicarboxylic acid component having an intrinsic viscosity of 0.5 to 1.0 measured at 35 ° C. using o-chlorophenol as a solvent. PET resin which is a resin made of ethylene glycol as a diol component and contains 1.0 to 9.0 mol% of diethylene glycol as a by-product as a diol component in 100 mol% of the diol component.

The polyethylene terephthalate resin is preferably a thermoplastic resin composed of 70% by weight or more, more preferably 80% by weight or more based on 100% by weight of the thermoplastic resin.

The thermoplastic resin of the present invention may contain the following components in addition to 30% by weight or less of the above PET resin in 100% by weight thereof.

First, in the present invention, a polyethylene naphthalate resin (component A-2) can be added, in addition to the above PET resin, for the purpose of improving heat resistance, and is preferably used. Polyethylene naphthalate resin (hereinafter sometimes abbreviated as PEN resin) is a resin mainly using 2,6-naphthalene dicarboxylic acid as a dicarboxylic acid component and using ethylene glycol as a diol component. The components may be copolymerized.

The method for producing the polyethylene naphthalate resin of the component A-2 used in the present invention is the same as that of the polyethylene terephthalate resin, according to a conventional method, in the presence of a polycondensation catalyst containing germanium, antimony, titanium or the like. This is carried out by polymerizing the dicarboxylic acid component and the diol component while discharging water or lower alcohol by-product to the outside of the system. For example, examples of the germanium-based polymerization catalyst include oxides, hydroxides, halides, alcoholates, and phenolates of germanium, and more specifically, germanium dioxide, germanium hydroxide, germanium tetrachloride, tetramethoxygermanium, And antimony trioxide.

In the present invention, compounds such as manganese, zinc, calcium, and magnesium used in a transesterification reaction which is a prior stage of a conventionally known polycondensation can be used together. Alternatively, it is possible to deactivate such a catalyst with a phosphorous acid compound or the like to perform polycondensation.

The method for producing the polyethylene naphthalate resin can be any of a batch method and a continuous polymerization method.

The intrinsic viscosity of the PEN resin is preferably 0.4 to 1.5, more preferably 0.5 to 1.0, more preferably 0.5 to 1.0, as measured at 35 ° C. using o-chlorophenol as a solvent. 55 to 0.95 is more preferable, and 0.
6 to 0.9 is particularly preferred. If the intrinsic viscosity is less than 0.4, the mechanical properties, rupture strength and elongation of the tube will be low, and if it exceeds 1.5, the melt processability of the tube will be poor, which is not preferable.

The terminal group structure of the polyethylene naphthalate resin used in the present invention is not particularly limited.
Other than the case where the ratio of the hydroxyl group to the carboxyl group in the terminal group is substantially the same, the case where one of the ratios is large may be used. Further, the terminal groups may be blocked by reacting a compound having reactivity with such terminal groups.

The content of the polyethylene naphthalate resin is a total of 1 component, A-2 component and A-3 component.
00% by weight, polyethylene naphthalate resin 0 to 30
%, Preferably 3 to 25% by weight, more preferably 3 to 20% by weight. If the content is more than 30% by weight, the coating processability decreases.

Further, in the present invention, in addition to the above PET resin, a polyester elastomer resin (component A-3) can be added for the purpose of improving mechanical properties such as impact resistance. is there. Polyester-based elastomer resin (hereinafter sometimes abbreviated as TPEE resin) is a resin in which a high melting point and high crystalline aromatic polyester is used for a hard segment and an amorphous polyester or an amorphous polyether is used for a soft segment. ,
The former is a polyester ester resin, and the latter is a polyether ester resin.

The polyetherester resin has 5 to 95% by weight of a hard segment and 5 to 95% by weight of a soft segment when the polyetherester resin is 100% by weight, and has an intrinsic viscosity of 0.4 to 2.0%. Range.

As the aromatic polyester of the hard segment of the polyetherester resin of the present invention, the dicarboxylic acid and diol components constituting the above-mentioned aromatic polyester resin can be used.
C. or higher is preferred.

Specifically, polybutylene terephthalate and polybutylene naphthalate, which are essentially composed of 1,4-butanediol and terephthalic acid or naphthalenedicarboxylic acid, are preferred. Such polybutylene terephthalate or polybutylene naphthalate includes other diols other than 1,4-butanediol, for example, ethylene glycol,
Diethylene glycol, triethylene glycol, neopentyl glycol, cyclohexane dimethanol, etc. can be copolymerized in an amount of 5 mol% or less based on 100 mol% of all diol components, and dicarboxylic acids other than terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, etc. Preferably, isophthalic acid can be copolymerized in an amount of 100 mol% or less and 10 mol% or less of all dicarboxylic acid components. Most preferred is polybutylene terephthalate consisting solely of 1,4-butanediol and terephthalic acid.

In the soft segment of the polyetherester resin of the present invention, the alkylene portion has 3 to 12 carbon atoms.
Mainly composed of a polyether glycol which is an alkylene or a 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 50% by weight or less of ether glycol], copolytetramethylene-1,2-cyclohexylene dimethylene glycol [where 1,2-cyclohexylene dimethylene oxide unit is 1 to 20% by mole of copolyether glycol] ] And other copolyether glycols. Of these, polytetramethylene is preferred.

When the polyester ester resin of the present invention is 100% by weight of the polyester ester resin,
5 to 95% by weight of hard segment, 5 of soft segment
９５95% by weight, with an intrinsic viscosity in the range of 0.4-2.0.

As the aromatic polyester of the hard segment of the polyester ester resin of the present invention, the dicarboxylic acid and diol components constituting the above-mentioned aromatic polyester resin can be used, and the melting point of this segment is 100 ° C.
The above is preferred.

Specifically, polybutylene terephthalate substantially consisting of 1,4-butanediol and terephthalic acid is preferred. 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 based on 100 mol% of all diol components. A dicarboxylic acid other than terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, or the like, 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 solely of 1,4-butanediol and terephthalic acid.

The soft segment of the polyester ester resin of the present invention is polycaprolactam, an aliphatic polyester such as polyethylene adipate from the above-mentioned aliphatic dicarboxylic acid and aliphatic diol, or a dicarboxylic acid component whose main component is an aromatic dicarboxylic acid. Wherein the alkylene moiety is an alkylene having 3 to 12 carbons or 4-1.
It is a polyester ether (hereinafter sometimes abbreviated as an aromatic polyester ether) with a diol component mainly composed of 0 cycloalkylene polyether glycols. Among them, aromatic polyester ethers are preferred.

As the dicarboxylic acid component of such an aromatic polyester ether, an aromatic dicarboxylic acid is preferably 70 mol% or more, more preferably 80 to 99 mol%, and most preferably 90 to 90 mol% in 100 mol% of the dicarboxylic acid component. 98 mol%. As such aromatic dicarboxylic acids, terephthalic acid, isophthalic acid and naphthalenedicarboxylic acid are preferred, and isophthalic acid is most preferred.
In addition, as the aliphatic dicarboxylic acid, adipic acid, sebacic acid, azelaic acid and the like, preferably adipic acid is copolymerized in less than 30 mol%, more preferably 1 to 20 mol%, most preferably 2 to 10 mol%. it can. On the other hand, typical examples of the diol component of the aromatic polyester ether include polyether glycols such as polypropylene glycol, polytrimethylene glycol, and polytetramethylene glycol, or copolyethylene-propylene glycol, copolyethylene-tetramethylene glycol [here, ethylene Oxide units comprise 50% by weight or less of copolyether glycol], copolytetramethylene-1,2-cyclohexylene dimethylene glycol [provided that 1,2-cyclohexylene dimethylene oxide units are 1 to 20% of copolyether glycol. Mol%]. Of these, polytetramethylene glycol is preferred.

The content of the polyester elastomer resin is as follows: A-1 minute, A-2 component and A-3 component in total of 1 minute.
00% by weight, polyester elastomer resin 0 to 3
The range is 0% by weight, preferably 3 to 25% by weight, and more preferably 3 to 20% by weight. If the content is more than 30% by weight, the coating processability deteriorates, and further, it becomes easy to swell at high temperatures.

As the aromatic polyester resin other than the PET resin, of the dicarboxylic acid component and the diol component forming the polyester resin, the dicarboxylic acid component 10
It is also possible to add a polyester resin in which 70 mol% or more, preferably 90 mol% or more, and most preferably 99 mol% or more of 0 mol% is an aromatic dicarboxylic acid.

Examples of the dicarboxylic acid include terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2,5-
Dichloroterephthalic acid, 2-methylterephthalic acid, 4,
4-stilbene dicarboxylic acid, 4,4-biphenyl dicarboxylic acid, orthophthalic 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 dicarboxylic acid, 5
-Na sulfoisophthalic acid, ethylene-bis-p-benzoic acid and the like. These dicarboxylic acids can be used alone or in combination of two or more.

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

As the diol component, for example, 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,
Examples thereof include 3-cyclohexanedimethanol, decamethylene glycol, cyclohexanediol, p-xylene diol, bisphenol A, tetrabromobisphenol A, and tetrabromobisphenol A-bis (2-hydroxyethyl ether). These can be used alone or in combination of two or more.

Specific examples of the aromatic polyester resin comprising a dicarboxylic acid component and a diol component include polybutylene terephthalate resin, polyethylene isophthalate resin, polyethylene naphthalate resin, polybutylene naphthalate resin, and polyethylene terephthalate / isolate. Examples include phthalate copolymer resins and polyethylene / neopentyl terephthalate copolymer resins. Among them, polyethylene naphthalate resin is preferred. These resins may be used alone or in combination of two or more.

The terminal group structure of the aromatic polyester resin that can be used in the present invention is not particularly limited, and the hydroxyl group and the carboxyl group in the terminal group may be substantially equal to each other, or if one of the ratios is large. There may be. Further, the terminal groups may be blocked by reacting a compound having reactivity with such terminal groups.

As a method for producing an aromatic polyester resin which can be used in the present invention, a production method similar to that for a polyethylene terephthalate resin can be employed.

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, polycarbonate resin,
Polyamide resin, acrylic resin, and various thermoplastic elastomers (for example, styrene, olefin, urethane, polyamide, 1,2-polybutadiene, vinyl chloride, fluorine [fluororubber], ionomer resin, chlorinated polyethylene , Silicones, etc.). Furthermore, IPN (Interpenerating)
Composite rubber of acrylic rubber and silicon rubber using Polymer Networks (interpenetrating network structure) technology. For example, Mitsubishi Rayon Co., Ltd. product name Metablen S-2
001 etc. One or more of these thermoplastic resins other than the polyester resin can be used.

The resin composition of the present invention is provided with an inorganic lubricant (component B) and / or an organic lubricant (component C) in order to impart lubricating properties and obtain good opening properties and good finishing properties when coated. Preferably. More preferably, it comprises a specific amount of a combination of an inorganic lubricant and an organic lubricant.

Examples of the inorganic lubricant of the component B of the present invention include kaolin, clay, calcium carbonate, silicon oxide,
Examples include inorganic inert external particles such as calcium terephthalate, aluminum oxide, titanium oxide, calcium phosphate, and lithium fluoride. The average particle size 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 size of the inorganic inert inert external particles is the particle size when the cumulative weight distribution of the weight distribution measured using a laser diffraction method (SALD-1100 manufactured by Shimadzu Corporation) becomes 50%. As the particle size distribution, it is extremely preferable to contain large inorganic inert particles having a particle size in the range of 4 to 30 μm. In such a range, even if the tube has a small thickness, a defect does not occur in the tube, and a good opening property can be achieved. The content of the large-diameter inorganic inert external particles is preferably from 2 to 80% by weight, more preferably from 10 to 70% by weight, most preferably from 20 to 60% by weight based on 100% by weight of all the inorganic inert external particles. is there.

The effect of the inclusion of the large-sized inorganic inert external particles is as follows.
In particular, it is remarkable in a tube having a low stretching ratio in which projections of large-diameter inorganic inert external particles due to stretching hardly occur. In addition, since these tubes are expanded by applying internal pressure to the unstretched tube and the diameter is regulated by the stretched tube, the outer surface in contact with the stretched tube has small projections of large-diameter inorganic inert external particles and has good printability. . On the other hand, on the inner surface of the tube that does not come into contact with the stretched tube, projections of large-diameter inorganic inert external particles are likely to appear, and therefore the opening property is improved.

The organic lubricant of the component C of the present invention includes hydrocarbon lubricants such as paraffin and polyethylene wax, higher fatty acid lubricants such as stearic acid, metal soap lubricants such as calcium stearate, and ester lubricants such as montanic acid wax. And organic fine particles such as a crosslinked acrylic resin containing benzoguanamine or polymethyl methacrylate as a main component. In particular, an organic lubricant which has a synergistic effect with an inorganic lubricant is optimally one which improves external lubricity and has good compatibility with a resin. In addition, it is necessary to satisfy conditions such as having heat stability at the time of extrusion. For a resin composition containing 70% by weight or more of a polyester resin, montanic acid wax is particularly preferable.

The montanic acid wax is a fossil wax montan wax mainly containing fatty acids and fatty alcohols having 21 to 34 carbon atoms obtained by solvent extraction of lignite, and a wax obtained by esterifying or partially saponifying the montan wax. It is. Specifically, Hoechst WAX S (Hoechs WAX) obtained by oxidizing montan wax
Hoechs, a montanic acid diester obtained by esterifying montan wax with ethylene glycol.
t WAX E (manufactured by Hoechst), montanic acid diester Hostalub WE40 (manufactured by Hoechst), which is obtained by esterifying montan wax with glycerin, and montan wax partially esterified with butylene glycol, and the remainder is saponified with calcium hydroxide. Hoechst is a partially saponified montanic acid ester
WAX OP (manufactured by Hoechst), among which Hoechst WAX E, HostalubW
E40 is preferred.

Inorganic lubricant (component B), organic lubricant (component C)
Is added to each of 100 parts by weight of the component A.
It is preferably from 02 to 4 parts by weight, more preferably from 0.1 to 2.5 parts by weight. In a more preferred embodiment, 0.05 to 1 part by weight of the component B and 0.0 part by weight of the component C are added to 100 parts by weight of the component A
It is a resin composition comprising 5 to 1 part by weight.

By combining an organic lubricant and an inorganic lubricant, effective formation of particle projections and surface lubricity are improved without problems such as a decrease in heat resistance, and an improvement in openability is achieved. Further, when the tube is cut, covered, or shrunk by the automatic mounting machine, the adhesion 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.

Such a heat-shrinkable tube is often folded into a tape, wound on a reel, and then shipped as a product. At this time, if the surface of the tube is poor in lubricity, it often occurs with a polyester film or the like. In some cases, a blocking phenomenon occurs, and the tubes adhere to each other so that they do not come off. This resin composition can also improve such a problem.

The most preferred 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 form a heat-shrinkable tube. In addition, there is a method in which a film extruded and stretched by using a T-die or an I-die is bonded by welding, welding, or bonding to form a tube, and a method in which the tube or film is spirally bonded to form a tube. .

Here, a method of extruding an unstretched tube by using a ring die and then stretching to form a heat-shrinkable tube will be described in further detail. The resin composition comprising the aromatic polyester resin 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, 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. Among them, a method of immersing in low-temperature water is effective because the cooling efficiency is high.
The unstretched tube may be continuously supplied to the next stretching step, or may be wound once into a roll and then used as a raw material in the next stretching step. From the viewpoint of production efficiency and thermal efficiency, a method in which an unstretched tube is continuously supplied to the next stretching step is preferable.

The unstretched tube thus obtained is biaxially stretched by pressurizing the inside of the tube with a compressed gas. Although the stretching method is not particularly limited, for example, pressure is applied from one end of an unstretched tube by a compressed gas to the inside of the tube while being sent at a constant speed, and then preheated with hot water or an infrared heater, and the like. Biaxial stretching is performed by placing the film in a stretching tube heated to a stretching temperature that regulates the stretching ratio. Temperature conditions and the like are set so that stretching is performed at an appropriate position in the stretching tube. After stretching, it is cooled, and is taken up and wound up as a stretching tube while holding the stretching pressure while being sandwiched between a pair of nip rolls. Stretching may be performed in either the longitudinal direction or the radial direction, but is preferably performed simultaneously.

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

The stretching conditions vary depending on the properties of the polymer to be used and the heat shrinkability of the target tube, but the stretching temperature is usually equal to or higher than the glass transition temperature to 105 ° C., preferably 70 ° C.
１００100 ° C.

The heat-shrinkable polyethylene terephthalate tube for coating a lithium ion battery of the present invention is obtained by stretching the unstretched tube 1.2 to 3.0 times in the radial direction and 1.0 to 2.0 times in the length direction. Those obtained by stretching are preferred. Further, the stretching ratio in the radial direction of the tube is 1.3 to 2.
5 times is preferable, and 1.4 to 2.0 times is more preferable. The stretching ratio in the longitudinal direction of the tube is preferably 1.02 to 1.5 times, 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 amount of shrinkage may not be obtained. On the other hand, if it exceeds three times, the heat resistance is reduced, and the tube swells at high temperature and cracks are likely to occur. Further, it is difficult to control the stretching ratio in the longitudinal direction of the tube.

If the stretching ratio in the longitudinal direction of the tube exceeds 2.0 times, the amount of shrinkage in the longitudinal direction increases, and it becomes difficult to stably coat the lithium ion battery, and the yield of the lithium ion battery is reduced. May decrease.

Regarding the structure of the component A, it is important that factors that enhance crystallinity, for example, a long-chain diol component, are not increased more than necessary. On the other hand, as described above, such a diol component is effective for obtaining good shrinkage characteristics, and is therefore preferably contained to some extent. Therefore, from this viewpoint, as the component A, as described above, diethylene glycol is used in an amount of 1.0 mol% in 100 mol% of the diol component.
PET containing not less than 9.0 mol% as a lower limit
Resins can be mentioned as a preferred embodiment.

Next, the reason why the cutting property of the tube affects the coating processability is not clear, but the present inventor considers as follows. In other words, when the blade for cutting the tube becomes severely worn, the cutting is not performed well, and the tube is easily stretched at the time of cutting. At that time, at the molecular level, the molecular chains of the non-crystalline portion are stretched and crystallized,
The stretched portion during the coating process was considered to be jagged at the cut surface because it was crystallized and did not shrink.

The heat-shrinkable polyethylene terephthalate tube for coating an aluminum electrolytic capacitor of the present invention obtained as described above is widely used for various purposes.
However, especially in the field where heat resistance is required,
It is desirable that the heat shrinkage be in a specific range. Since such a draw ratio greatly affects the heat shrinkage, it is necessary to achieve the required heat shrinkage as low as possible.

From this point of view, the stretched polyethylene terephthalate tube of the present invention can be used in hot water at 100 ° C. for 30 minutes.
Heat shrinkage when immersed for 20 seconds in the radial direction of the tube
A preferred embodiment of the present invention is a heat-shrinkable polyethylene terephthalate tube having 50% and 0 to 20% in the length direction of the tube. Such a shrinkage ratio range provides both the good coverage and the heat resistance of the coated aluminum electrolytic capacitor component. More preferably, the heat shrinkage is 35 to 45% in the radial direction of the tube and 1 to 15% in the longitudinal direction of the tube.

The resin composition of the present invention may be used by mixing the above-mentioned components in advance using a mixer such as a tumbler, a V-type blender, a Nauter mixer, a Banbury mixer, a kneading roll, and an extruder. The measured components may be directly supplied to a supply port of an extruder for extruding a stretching tube, or separately measured components may be supplied to each supply port of an extruder having two or more supply ports.

Further, various additives and inorganic fillers may be added in amounts not to impair the object of the present invention, so that the effects are exhibited. 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 (such as sodium antimonate and antimony trioxide), anti-dripping agents (such as polytetrafluoroethylene having fibril forming ability), antioxidants (such as hindered phenol compounds), ultraviolet absorbers, and mold release Agents, lubricants, coloring agents and the like. Examples of the inorganic filler include glass beads, talc, and mica.

In order to avoid hydrolysis of the polyethylene terephthalate resin, the resin composition of the present invention has a water content of 0.1 in advance.
It is dried so as to be 1% by weight or less, preferably 0.05% by weight or less. For example, 170 ° C. for 3 hours, 150 ° C. for 1 hour
Dry for 2 hours at 120 ° C. for 24 hours under vacuum.

The structure of the lithium ion battery in the present invention is not particularly limited, but a composite metal oxide composed of Li ions and a specific metal (for example, LiCO ₂ , LiMn ₂ O _2, etc.) as a cathode material Using a carbonaceous material as a negative electrode active material, forming a laminated electrode between a positive electrode and a negative electrode with a diaphragm interposed therebetween, and using LiPF ₆ , L
Examples thereof include those using an aprotic organic solvent in which a Li salt such as iBF ₄ , LiClO ₄ , and LiAsF ₆ is dissolved (for example, dimethyl sulfoxide, ethylene carbonate, propylene carbonate, 1,3-dooxolan, tetrahydrofuran, and the like). Examples of the shape include a paper battery, a button battery, a stacked battery, a cylindrical battery, a square battery, and the like. These are applications requiring higher energy density, smaller size and lighter weight than nickel-cadmium batteries or nickel-metal hydride batteries, which have been the mainstream of small secondary batteries, such as notebook computers, mobile phones, personal digital assistants, and portable M-cells.
It is used as a power source for D players and the like. In recent years, it is a rechargeable secondary battery whose market is rapidly expanding. The shrinking of the heat-shrinkable tube into the lithium-ion battery is performed by inserting the lithium-ion battery into the tube and using a heat source such as hot air or a far-infrared heater to reduce the temperature from 120 ° C to 30 ° C.
Heating is performed at a temperature of 0 ° C. for 5 seconds to several tens of seconds.

[0078]

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

(1) Amount of Diethylene Glycol About 0.2 g of PET was precisely weighed, and an ethanol decomposition solution (a substance accurately weighed to about 0.2 g of tetraethylene glycol dimethyl ether (TEGDME) and precisely adjusted to 50 ml with purified ethanol) was prepared. And 1 ml together in a glass pressure-resistant container. After decomposing with ethanol at 260 ± 5 ° C. for 5 hours in an autoclave, measurement is performed by gas chromatography using TEGDME as an internal standard.

(2) Heat Shrinkage Rate A heat-shrinkable tube having a length of 10 cm was placed in hot water at 100 ° C. for 30 minutes.
The length before and after the immersion for 2 seconds and the outer diameter were measured with a digital caliper, and were calculated by the following equation (1). Five samples were measured and the average was calculated.

[0081]

(Equation 1)

(3) Heat resistance test A lithium ion battery was inserted into a heat-shrinkable tube, and 200
The lithium ion battery covered with this heat-shrinkable tube was shrink-processed at 18 ° C. × 18 seconds, and dried at 150 ° C. for 2 seconds.
After standing for a period of time, the swelling, dissolution, cracking and detachment of the shoulder due to secondary shrinkage of the tube were visually evaluated. The evaluation was performed on 10 samples for each sample. (Evaluation) ；: No change in tube swelling, dissolution, cracking, and off-shoulder was observed in all coated lithium ion batteries of heat-shrinkable tube after heat resistance test. △: Tube swelling, dissolution, crack, Some of the heat shrink tubing changes slightly off shoulder. However, this is a level that does not cause any problem in the function of the product. ×: After the heat resistance test, any change of tube swelling, melting, cracking, or off-shoulder has occurred, which may cause problems in the function of the product. did.

(4) Impact Resistance Insert a lithium ion battery into a heat-shrinkable tube and insert
The lithium-ion battery covered with the heat-shrinkable tube was shrunk at 18 ° C. × 18 seconds.
Drop to a concrete surface from a height of cm. At that time,
Visually check whether cracks have occurred in the tube and the insulating plate has not protruded. The evaluation was performed on 10 samples for each sample. (Evaluation) ；: After the drop test, no crack was generated in the tube, and no insulating plate was observed in all lithium ion batteries.

Δ: After the drop test, cracks were generated in the tube, but no insulating plate was seen. However, this is a level at which there is no problem in the function as a product. ×: After the heat resistance test, cracks occurred in the tube, an insulating plate was seen, and there was a problem that caused a problem in the function as a product.

(5) Cutting performance A condenser was inserted into the stretched tube, and the tube was cut by an automatic cutter.
Allow the capacitor to coat in seconds. Thereafter, the end portion of the cut surface was visually evaluated. The evaluation was performed on 10 samples for each sample. ；: The end of the cut surface is covered neatly. C: A part or the whole of the end of the cut surface is jagged.

(6) Opening property The rolled tube was bent in parallel with the length direction after pressure bonding with a roll so that air did not remain on the inner surface of the stretched tube, and evaluated as follows. ；: Mouth opened with only one bend and good opening. △; Mouth opened two times. ×; Mouth did not open even after three or more turns, resulting in poor opening.

(7) Embrittlement with time The stretched tube was left in a dryer at 40 ° C. for 4 weeks, and then the elongation at break of the tube in the length direction was measured. The elongation at break in the length direction of the stretched tube before the heat treatment was also measured. The elongation at break was measured by punching a test piece in parallel with the length direction using an ASTM D638 type V dumbbell at a tensile speed of 10 mm / min.

Examples 1 to 9 and Comparative Examples 1 to 6 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, and immersed in water.
0.5 kg of an unstretched tube obtained by cooling and solidifying is used as it is in 90 ° C. hot water using a stretched tube having an inner diameter of 18.8 mmφ.
The tube was stretched under the conditions shown in Tables 1 and 2 by applying an internal pressure to the tube with compressed air of / cm ² and then cooled with water to obtain a stretched heat-shrinkable tube shown in Tables 1 and 2. Tables 1 and 2 show the shape and characteristics of the obtained heat-shrinkable tube.

The abbreviations in Tables 1 and 2 mean the following. (A-1) Polyethylene terephthalate resin PET-1: An acid component is composed of 100 mol% of terephthalic acid, a diol component is composed of 96.6 mol% of ethylene glycol, and diethylene glycol is composed of 3.4 mol%, and [η] = 0.
85 polyethylene terephthalate resin PET-2: 100 mol% of terephthalic acid as an acid component, 98.8 mol% of ethylene glycol as a diol component, 1.2 mol% of diethylene glycol, and [η] = 0.
Polyethylene terephthalate resin of No. 65 (A-2) Polyethylene naphthalate resin PEN: Polyethylene naphthalate resin of [η] = 0.60 (A-3) Polyester elastomer resin TPE-1: The hard segment is polybutylene terephthalate and Polyetherester resin in which the soft segment is composed of polytetramethylene glycol TPE-2: Polyesterester resin in which the hard segment is polybutylene terephthalate and the soft segment is composed of an aromatic polyesterether (other than the component A) PET-3: An acid component 100 mol% of terephthalic acid, 99.4 mol% of a diol component of ethylene glycol and 0.6 mol% of diethylene glycol, and [η] = 0.
Polyethylene terephthalate resin No. 65 PET-4: 100 mol% of terephthalic acid in acid component, 90.0 mol% of diol component in ethylene glycol, 10.0 mol% of diethylene glycol, [η] =
0.85 polyethylene terephthalate resin PET-5: polyethylene terephthalate / isophthalate in which the acid component is composed of 89 mol% of terephthalic acid, 11 mol% of isophthalic acid, the diol component is composed of 100 mol% of ethylene glycol, and [η] = 0.7. Resin PET-6: Neopentyl copolymerized polyethylene terephthalate resin in which the acid component is 100 mol% of terephthalic acid, the diol component is 88 mol% of ethylene glycol and 12 mol% of neopentyl glycol, and [η] = 0.71.

(B) Inorganic lubricant Inorganic lubricant; average particle size 4.8 μm, particle size 4.0 to 5.3 μm
m of the large external inert particles of 13.4% by weight, 5.3 to 5.3%
7.5 μm at 16.2 wt%, 7.5 to 11.0 μm at 15.0 wt%, 11 to 16 μm at 10.4 wt%, 1
2.6% by weight of 6 to 22 μm, 0.2% by weight of 22 to 30 μm
Kaolin containing by weight. (All inert external particles 10
5 to 30 μm of large external inert particles in 0% by weight
(Contains 7.8% by weight)

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

[0092]

[Table 1]

[0093]

[Table 2]

[0094]

The heat-shrinkable aromatic polyethylene talephthalate tube comprising a thermoplastic resin containing at least 70% by weight of the polyethylene terephthalate resin of the present invention and an inorganic lubricant and / or an organic lubricant is added. As is clear from the examples 1 and 2, the amount of the diethylene glycol component in the polyethylene terephthalate resin is from 1.0 to 1.0.
When the content is in the range of 9.0 mol%, the material has excellent cutting properties, excellent shrinkage properties and openability when coated on a lithium ion battery, and excellent heat resistance and impact resistance capable of maintaining a good coated state. It is. Further, even when the drawn tube is stored at a high temperature of 40 ° C. for a long time, the tube is excellent in less embrittlement with time. Further, the present invention provides a heat-shrinkable polyethylene terephthalate tube which can make use of the burning resistance, electrical properties, and chemical resistance of the resin composition and can utilize these properties as a material for coating a lithium ion battery.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01M 2/02 H01M 2/02 F // B29K 67:00 B29K 67:00 105: 02 105: 02 B29L 23 : 00 B29L 23:00 F term (reference) 4F071 AA43 AA45 AA46 AA47 AA71 AB15 AB18 AB21 AB25 AB26 AB30 AC09 AE11 AF61 AH04 BB07 BC05 4F210 AA24 AB07 AE01 AG08 AH33 RA03 RC02 RG02 RG07 RG30 CF04 RG43 BF4 003 CF173 DD036 DE136 DE146 DE236 DH046 DJ016 DJ036 EF057 EG037 EG106 EU187 FD174 FD176 FD177 GG02 5H011 AA02 AA09 AA17 CC00 CC02 DD09 DD23 KK00 KK02

Claims (5)

[Claims] (1) The diethylene glycol component (A) comprises:
A tube made of a resin composition mainly composed of a thermoplastic resin (component (A)) containing 70% by weight or more of a polyethylene terephthalate resin containing 0 to 9.0% by mole, and 30% of hot water at 100 ° C. of the tube. A heat-shrinkable polyethylene terephthalate tube for coating a lithium ion battery, wherein the heat-shrinkage ratio when immersed for 2 seconds is 20 to 50% in the radial direction of the tube and 0 to 20% in the length direction of the tube. 2. A component (A-1) comprising 70 to 99% by weight of a polyethylene terephthalate resin (A-1 component) containing 1.0 to 9.0 mol% of a diethylene glycol component; The heat shrinkage for coating a lithium ion battery according to claim 1, wherein the phthalate resin (A-2 component) is 1 to 30% by weight and / or the (A-3) polyester elastomer (A-3 component) is 1 to 30% by weight. Polyethylene terephthalate tube. 3. The resin composition is used in an amount of 0.02 to 4 parts by weight of (B) an inorganic lubricant (component B) and / or 0.02 to 4 parts by weight of (C) an organic lubricant (component C) based on 100 parts by weight of component A. The heat-shrinkable polyethylene terephthalate tube for coating a lithium ion battery according to claim 1, which is a resin composition containing parts by weight. 4. The tube is obtained by stretching an unstretched tube 1.2 to 3.0 times in the radial direction of the tube and 1.0 to 2.0 times in the length direction of the tube. The heat-shrinkable polyethylene terephthalate tube for coating a lithium ion battery according to claim 1. 5. The resin composition comprises (B) 0.05 to 1 part by weight of an inorganic lubricant (component B) and 0.05 to 1 part by weight of (C) an organic lubricant (component C) based on 100 parts by weight of component A. The heat-shrinkable polyethylene terephthalate tube for coating a lithium ion battery according to claim 1, comprising a part.