CN100453585C - Production method of thermoplastic resin microporous membrane - Google Patents

Production method of thermoplastic resin microporous membrane Download PDF

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Publication number
CN100453585C
CN100453585C CNB2004800250073A CN200480025007A CN100453585C CN 100453585 C CN100453585 C CN 100453585C CN B2004800250073 A CNB2004800250073 A CN B2004800250073A CN 200480025007 A CN200480025007 A CN 200480025007A CN 100453585 C CN100453585 C CN 100453585C
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solvent
clean
mentioned
cleaning
film
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CN1845955A (en
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铃木贞胜
君岛康太郎
滝田耕太郎
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Toray Industries Inc
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Tonen Sekiyu Kagaku KK
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Abstract

A method for producing a micro-porous film of a thermoplastic resin, wherein a thermoplastic resin and a solvent for forming a film are together molten and kneaded to form a solution, the solution is extruded from a die and then cooled to prepare a gelated product, the residue of the above solvent for film forming is removed from the gelated product by using a solvent for cleaning, and the solvent for cleaning is removed, which comprises using, as the solvent for cleaning, a solvent having (a) a surface tension at 25 DEG C of 24 mN/m or less, (b) a boiling point under atmospheric pressure of 100 DEG C or lower, and (c) a solubility into water at 16 DEG C of 600 ppm (on mass basis) or less, and further comprises removing the residue of the above solvent for cleaning from the product after the above cleaning by the use of warm water.

Description

The manufacture method of thermoplastic resin micro-porous film
Technical field
The present invention relates to the manufacture method of thermoplastic resin micro-porous film, particularly, relate to and suppressing to be used to remove film forming with solvent clean volatilization and the film method of making thermoplastic resin micro-porous film when shrinking with solvent.
Background technology
Thermoplastic resin micro-porous film is widely used in various uses such as battery separator, electrolytic condenser barrier film, various strainer, moisture-permeability waterproof dress material, osmosis filtration film, ultra-filtration membrane, secondary filter film.
When making thermoplastic resin micro-porous film, use solvent or softening agent, but, be necessary to remove the gel forming composition after film forming for not residual in end article by damp process.The solvent (film forming solvent) or the softening agent that add when removing film forming, use usually methylene dichloride etc. volatile clean with solvent the gel forming composition is cleaned after, carry out warm air drying.,, cause microporous membrane to shrink, therefore, have the hole rate of micro-porous film and the problem that perviousness reduces because evaporable is cleaned with the surface tension between solvent and the micro-pore wall when warm air drying.
Therefore, in the past, gel forming composition remained on tenter machine on one side be blown into hot blast on one side, or carried out drying by contacting with the multistage warming mill., particularly when removing clean solvents such as high-volatile methylene dichloride, the convergent force of micro-porous film is excessive for the tentering mode, and existence must injure micro-porous film and the problem of clamping (グ リ Star プ).And this kind mode needs a large amount of hot blasts.On the other hand, though multistage warming mill mode is used the path roller usually, the problem that exists micro-porous film to shrink at width in the roller gap.Though the drying means of combination multistage warming mill and hot blast insufflation is also arranged, clean and use the volatilization of solvent violent, it is difficult cleaning with solvent with simple cooling cohesion recovery.And, any method, clean when using solvent what use that methylene dichloride etc. has environmental pollution danger, must prevent its leakage.
Make the method for micro-porous film as the contraction when suppressing dry, the spy opens 2002-256099 number (patent documentation 1), and to have proposed to use the surface tension under 25 ℃ temperature be the method for 24mN/m or the clean usefulness solvent below the 24mN/m.If use so clean solvent of using, when drying, can suppress because the contraction of the reticulattion that the tension force of the inner liquid-vapo(u)r interface of micropore produces., because heating micro-porous film or air-dry exists and cleans with the slow-footed problem of removing of solvent.In addition, also exist evaporable to clean and be leaked to problem outside the manufacturing system easily with solvent.
The spy opens 2003-82151 number (patent documentation 2) and has proposed in the manufacturing process of micro-porous film, with suction roll handover gel forming composition on one side remove the method cleaned with solvent on one side.This method can prevent to clean the evaporation distribution with solvent.If particularly for cleaning, clean and remove the effect height with solvent with suction gel forming composition in the poor solvent of solvent., in the method, exist in formation on the micro-porous film because the suction socket of roller or the problem of the vestige (suction vestige) that cause in the hole.
Patent documentation 1: the spy opens 2002-256099 number
Patent documentation 2: the spy opens 2003-82151 number
Summary of the invention
The problem that invention will solve
Therefore, the object of the present invention is to provide when suppressing to be used to remove the clean volatilization and film contraction with solvent of film forming, promptly make the method for appearance character thermoplastic resin excellent micro-porous film with solvent.
Solve the means of problem
Present inventors in view of above-mentioned problem and concentrate one's attention on research found that, (a) by using cleaning of low surface tension and low water solubility to remove the film forming solvent with solvent, use simultaneously the forming composition of warm water after cleaning and remove the remaining above-mentioned clean solvent of using, the volatilization and the film that can suppress to clean with solvent shrink, and promptly make appearance character thermoplastic resin excellent micro-porous film simultaneously; And (b) by clean with solvent remove film forming with solvent after, so that the forming composition after cleaning with for above-mentioned clean poor solvent state of contact with solvent, forming composition after making above-mentioned poor solvent by above-mentioned clean by suction unit is removed above-mentioned clean when using solvent, by adjusting the forming composition after above-mentioned clean and the duration of contact of above-mentioned suction unit, the volatilization and the film that can suppress to clean with solvent shrink, simultaneously promptly make appearance character thermoplastic resin excellent micro-porous film, finished the present invention based on this discovery.
Promptly, the manufacture method of first kind of thermoplastic resin micro-porous film of the present invention is characterised in that, have by mouth mould extruding thermoplastic resins and film forming and carry out melting mixing with solvent and the solution that obtains, and by clean with solvent remove above-mentioned film forming remaining in the gel forming composition that cooling obtains with solvent after, remove above-mentioned clean operation with solvent, as the above-mentioned clean solvent of using, use (a) surface tension under 25 ℃ temperature as 24mN/m or below the 24mN/m, (b) boiling point under atmospheric pressure is below 100 ℃ or 100 ℃, and (c) solubleness to water is 600ppm (quality criteria) or the solvent below the 600ppm under 16 ℃ temperature, simultaneously, use warm water, from the forming composition after above-mentioned the cleaning, remove remaining above-mentioned cleaning and use solvent.
More than preferred above-mentioned clean boiling point-5 with solvent (below, only otherwise specify, be called " clean and use solvent orange 2 A ") of the lower limit temperature of warm water ℃ or the boiling point-5 ℃, be more preferably boiling point or more than the boiling point, especially preferably more than boiling point+3 ℃ or boiling point+3 ℃.The crystallization dispersion temperature of the preferred above-mentioned thermoplastic resin of ceiling temperature of warm water or below it is more preferably below crystallization dispersion temperature-5 ℃ or the crystallization dispersion temperature-5 ℃.Forming composition after clean (below, only otherwise specify, be called " cleaning forming composition ") in remove clean with solvent orange 2 A remove can by with the method for the clean forming composition of warm water drip washing, will clean forming composition and be immersed in the method in the warm water or undertaken by these the method for combination.As the method for cleaning forming composition with warm water drip washing, preferred one side carries the drip washing on one side of clean forming composition to clean the method that the forming composition volume hangs over the part on the roller by roller continuously.Be immersed in method in the warm water as cleaning forming composition, preferably in warm water, shake clean forming composition, perhaps carry continuously by roller on one side and clean forming composition and clean the method that the forming composition volume hangs over the part dipping on the roller to the major general on one side.The duration of contact of cleaning forming composition and warm water is preferred below 15 seconds or 15 seconds.
In order to obtain having the thermoplastic resin micro-porous film of excellent specific property, above-mentioned cleaning preferably satisfied following condition (1)~(11) with solvent orange 2 A.
(1) surface tension is 20mN/m or below the 20mN/m under 25 ℃ temperature.
(2) boiling point under atmospheric pressure is below 80 ℃ or 80 ℃.
(3) under 16 ℃ temperature, be 300ppm (quality criteria) or below the 300ppm to the solubleness of water.
(4) be that 5~7 n-paraffin, carbonatoms are that 5~7 isoparaffin and carbonatoms are at least a in 5~7 the naphthenic hydrocarbon for being selected from hydrofluoroalkane, hydrogen fluorine ether, perfluor alkane, perfluor ether, carbonatoms.
(5) hydrofluoroalkane of record is composition formula C in above-mentioned (4) 5H 2F 10The chain hydrofluoroalkane of expression.
(6) the hydrogen fluorine ether of record is composition formula C in above-mentioned (4) 4F 9OCH 3Or C 4F 9OC 2H 5The compound of expression.
(7) the perfluor alkane of record is composition formula C in above-mentioned (4) 6F 14Or C 7F 16The compound of expression.
(8) the perfluor ether of record is composition formula C in above-mentioned (4) 4F 9OCF 3Or C 4F 9OC 2F 5The compound of expression.
(9) carbonatoms of record is that 5~7 n-paraffin is to be selected from least a in Skellysolve A, normal hexane and the normal heptane in above-mentioned (4).
(10) carbonatoms of record is that 5~7 isoparaffin is for being selected from 2-methylpentane, 3-methylpentane, 2 in above-mentioned (4), 2-dimethylbutane, 2,3-dimethylbutane, 2-methyl hexane, 3-methyl hexane, 3-ethylpentane, 2,2-dimethylpentane, 2,3-dimethylpentane, 2,4-dimethylpentane, 3,3-dimethylpentane and 2,2, at least a in the 3-triptane.
(11) carbonatoms of record is that 5~7 naphthenic hydrocarbon is to be selected from least a in pentamethylene, hexanaphthene and the methylcyclopentane in above-mentioned (4).
Can be undertaken by two-stage or the operation more than the two-stage with removing of solvent by above-mentioned clean above-mentioned film forming with solvent.At this moment, use to clean in terminal stage at least and use solvent orange 2 A, also can use above-mentioned clean with beyond the solvent orange 2 A cleaned with solvent (below, only otherwise specify, be called " the clean solvent B that uses ").Can use separately to clean and use solvent orange 2 A, perhaps also can use and clean with solvent orange 2 A and the clean solvent B that uses.Clean operation is not limited to the two-stage, also can be for three stages or more than three stages.The upper limit of cleaning the hop count of operation can be for about seven stages.
Clean and preferably satisfy following condition (12)~(25) with solvent B.
(12) for being selected from methylene dichloride, tetracol phenixin, Halothane, methylethylketone, pentane, hexane, heptane, ether with at least a in the diox.
(13) boiling point is more than 100 ℃ or 100 ℃, and flash-point is the non-water solvent more than 0 ℃ or 0 ℃.
(14) non-water solvent of record is that to be selected from carbonatoms be n-paraffin more than 8 or 8 in above-mentioned (13), the carbonatoms that at least a portion of hydrogen atom is replaced by halogen atom is the n-paraffin more than 5 or 5, carbonatoms is the isoparaffin more than 8 or 8, carbonatoms is the naphthenic hydrocarbon more than 7 or 7, the carbonatoms that at least a portion of hydrogen atom is replaced by halogen atom is the naphthenic hydrocarbon more than 5 or 5, carbonatoms is the aromatic hydrocarbons more than 7 or 7, the carbonatoms that at least a portion of hydrogen atom is replaced by halogen atom is the aromatic hydrocarbons more than 6 or 6, the carbonatoms that the part of hydrogen atom is replaced by halogen atom is 5~10 alcohol, the carbonatoms that the part of hydrogen atom is replaced by halogen atom is 5~14 ester, the carbonatoms that the part of hydrogen atom is replaced by halogen atom is 4~14 ether, and carbonatoms is at least a in 5~10 the ketone.
(15) in above-mentioned (14) carbonatoms of record be n-paraffin 8 or 8 or more to be more preferably carbonatoms be 8~12, particularly, for being selected from octane, positive nonane, n-decane, at least a in hendecane, the positive 12 carbon alkane just.
(16) carbonatoms that at least a portion of hydrogen atom of record is replaced by halogen atom in above-mentioned (14) is that n-paraffin more than 5 or 5 is for being selected from 1-chloropentane, 1-chlorohexane, 1-chloroheptane, 1-chloro-octane, 1-bromo pentane silane, hexyl bromide 1 bromohexane, 1-heptyl bromide, 1-bromooctane, 1,5-dichloropentane, 1,6-dichloro hexane and 1, at least a in 7-two chloroheptanes.
(17) carbonatoms of record is that isoparaffin more than 8 or 8 is for being selected from 2,3,4-trimethylpentane, 2,2 in above-mentioned (14), 2,5-trimethyl cyclohexane, 2,3,5-trimethyl cyclohexane, 2,3,5-trimethylammonium heptane and 2,5, at least a in the 6-trimethylammonium octane.
(18) carbonatoms of record is that naphthenic hydrocarbon 7 or 7 or more is for being selected from suberane, cyclooctane, methylcyclohexane, suitable-and instead-1 in above-mentioned (14), 2-dimethyl cyclohexane, suitable-and anti--1,3-dimethyl cyclohexane and suitable-and anti--1, at least a in the 4-dimethyl cyclohexane.
(19) carbonatoms that the part of hydrogen atom of record is replaced by halogen atom in above-mentioned (14) is that the naphthenic hydrocarbon more than 5 or 5 is to be selected from least a in chlorocyclopentane and the chlorocyclohexane.
(20) carbonatoms of record is that aromatic hydrocarbons more than 7 or 7 is to be selected from least a in toluene, o-Xylol, m-xylene and the p-Xylol in above-mentioned (14).
(21) carbonatoms that the part of hydrogen atom of record is replaced by halogen atom in above-mentioned (14) is that the aromatic hydrocarbons more than 6 or 6 is to be selected from least a in chlorobenzene, 2-toluene(mono)chloride, 3-toluene(mono)chloride, 4-toluene(mono)chloride, 3-chloro-o-xylene, 4-chloro-o-xylene, 2-chloro-m-xylene, 4-chloro-m-xylene, 5-chloro-m-xylene and the 2-chloro-p-xylene.
(22) carbonatoms that the part of hydrogen atom of record is replaced by halogen atom in above-mentioned (14) is that 5~10 alcohol is to be selected from least a in primary isoamyl alcohol, tertiary amyl alcohol, cyclopentanol, hexalin, 3-methoxyl group-1-butanols, 3-methoxyl group-3-methyl isophthalic acid-butanols, propylene glycol n-butyl ether and the 5-chloro-1-amylalcohol.
(23) carbonatoms that the part of hydrogen atom of record is replaced by halogen atom in above-mentioned (14) is that 5~14 ester is to be selected from least a in diethyl carbonate, ethyl maleate, n-propyl acetate, n-butyl acetate, Isoamyl Acetate FCC, acetate 3-methoxyl group butyl ester, acetate 3-methoxyl group-3-methyl butyl ester, butanic acid ethyl ester, ethyl n-valerate and the acetate 2-chloroethene ester.
(24) carbonatoms that the part of hydrogen atom of record is replaced by halogen atom in above-mentioned (14) is that 4~14 ether is to be selected from least a in n-butyl ether, ethyl isobutyl ether and the Dichloroethyl ether.
(25) carbonatoms of record is that 5~10 ketone is to be selected from least a in 2 pentanone, propione, methyl-n-butyl ketone, 3-hexanone, cyclopentanone and the pimelinketone in above-mentioned (14).
The manufacture method of second kind of thermoplastic resin micro-porous film of the present invention is characterised in that, have from mouth mould extruding thermoplastic resins and film forming and carry out melting mixing with solvent and the solution that obtains, and by clean with solvent from the gel forming composition that cooling obtains, remove remaining above-mentioned film forming with solvent after, so that the forming composition after above-mentioned clean with for above-mentioned clean poor solvent state of contact with solvent, forming composition after making above-mentioned poor solvent by above-mentioned clean by suction unit is removed above-mentioned clean operation with solvent, and makes the forming composition after above-mentioned the cleaning and t duration of contact (second) of above-mentioned suction unit satisfy following general formula (1):
t≤(100-T) 3/(1100×P 0.5×logL)...(1)
[in the formula, T be above-mentioned poor solvent temperature (℃), P is swabbing pressure (kPa), L is the size (diameter of the maximum inscribed circle of above-mentioned open-work (μ m)) of the open-work of above-mentioned suction unit] scope.
The forming composition after above-mentioned the cleaning and the duration of contact of above-mentioned suction unit are preferred more than 0.05 second or 0.05 second, are more preferably more than 0.2 second or 0.2 second.As above-mentioned suction unit, preferred suction roll is more preferably and is selected from least a in wire roll, slit roller (ス リ Star ト ロ one Le), the punching roller (パ Application チ Application グ ロ one Le), preferred especially wire roll.Above-mentioned open-work gravel size decision 10~5000 μ m are more preferably 20~2000 μ m, preferred especially 50~500 μ m.Preferred 0.5~the 60kPa of above-mentioned swabbing pressure is more preferably 1~40kPa, preferred especially 3~20kPa.The preferred above-mentioned clean boiling point-10 with solvent of the temperature of above-mentioned poor solvent ℃~boiling point+50 ℃ are more preferably above-mentioned clean boiling point~boiling point+50 with solvent ℃, preferred especially above-mentioned clean boiling point+3 with solvent ℃~boiling point+50 ℃.Above-mentioned poor solvent preferably water.
As the method that above-mentioned clean forming composition is contacted with above-mentioned poor solvent, preferably with above-mentioned poor solvent drip washing to above-mentioned clean forming composition volume hang over the part on the roller method, clean the forming composition volume to the major general and hang over part on the roller and be immersed in the method in the above-mentioned poor solvent or the method for their combination.
Above-mentioned thermoplastic resin preferably satisfies following condition (26)~(35).
(26) for being selected from least a in polyolefine, polyester, polymeric amide, poly-inferior aryl oxide and the polyarylene sulfide.
(27) polyolefine of record is polyethylene or polyethylene composition in above-mentioned (26).
(28) the poly weight-average molecular weight of record is 1 * 10 in above-mentioned (27) 4~5 * 10 6
(29) the poly weight-average molecular weight of record is 1 * 10 in above-mentioned (28) 5~4 * 10 6
(30) polyethylene of each record in above-mentioned (27)~(29) is to be selected from least a in ultrahigh molecular weight polyethylene(UHMWPE), high density polyethylene(HDPE), medium-density polyethylene and the new LDPE (film grade).
(31) polyethylene of each record in above-mentioned (27)~(30) is that weight-average molecular weight is 5 * 10 5Or 5 * 10 5Above ultrahigh molecular weight polyethylene(UHMWPE).
(32) the ratio Mw/Mn (molecular weight distribution) of the poly weight-average molecular weight (Mw) of each record in above-mentioned (27)~(31) and number-average molecular weight (Mn) is 5~300.
(33) polyethylene composition of record must have ultrahigh molecular weight polyethylene(UHMWPE) in above-mentioned (27), in addition, also contains and is selected from least a in high density polyethylene(HDPE), medium-density polyethylene and the new LDPE (film grade).
(34) in above-mentioned (33) polyethylene composition of record to contain weight-average molecular weight be 5 * 10 5Or 5 * 10 5Above ultrahigh molecular weight polyethylene(UHMWPE) and weight-average molecular weight are 1 * 10 4Or 1 * 10 4More than but less than 5 * 10 5High density polyethylene(HDPE).
(35) weight-average molecular weight that is selected from that the polyethylene composition of record contains as any composition in above-mentioned (33) or (34) is 1 * 10 4~4 * 10 6Polypropylene, weight-average molecular weight in the scope are 1 * 10 4~4 * 10 6Polybutene-1, weight-average molecular weight in the scope are 1 * 10 3~4 * 10 4Polyethylene wax and weight-average molecular weight in the scope are 1 * 10 4~4 * 10 6At least a polyolefine in the ethylene of scope.
The effect of invention
According to first and second kinds of manufacture method of the present invention, can suppress to be used to remove film forming with solvent clean with solvent volatilization and the film contraction in promptly make thermoplastic resin micro-porous film.By first and second kinds of thermoplastic resin micro-porous films that manufacture method obtains of the present invention, hole rate, Gas permeability and heat-resisting shrinkability excellence, and do not have washmarking (bullate vestige) and suction vestige, appearance character is also excellent.Micro-porous film with such characteristic is suitable in battery separator, the strainer etc.
Description of drawings
Fig. 1 is the photo of outward appearance that the micro-porous film of embodiment 1 is shown.
Fig. 2 is the photo of outward appearance that the micro-porous film of comparative example 2 is shown.
The preferred plan that carries out an invention
[1] thermoplastic resin
As operable thermoplastic resin when the manufacturing of thermoplastic resin micro-porous film of the present invention, can enumerate polyolefine, polyester, polymeric amide, poly-inferior aryl oxide and polyarylene sulfide, wherein, preferred polyolefm.Polyolefine can be any one of single thing or the composition that is made of two or more polyolefine.
As polyolefine, can use any in the homopolymer of ethene, propylene, butene-1, amylene-1, hexene-1,4-methylpentene-1, octene, vinyl acetate between to for plastic, methyl methacrylate, vinylbenzene etc. and the multipolymer.Wherein, as polyolefine, preferably polyethylene.Poly weight-average molecular weight is not particularly limited, and is generally 1 * 10 4~1 * 10 7, preferred 1 * 10 4~5 * 10 6, be more preferably 1 * 10 5~4 * 10 6
As polyethylene, can enumerate ultrahigh molecular weight polyethylene(UHMWPE), high density polyethylene(HDPE), medium-density polyethylene and new LDPE (film grade).These polyethylene also can be to contain the multipolymer of other alpha-olefin on a small quantity.Other alpha-olefin as beyond the ethene can use propylene, butene-1, amylene-1, hexene-1,4-methylpentene-1, octene, vinyl acetate between to for plastic, methyl methacrylate, vinylbenzene etc.Wherein, as polyethylene, preferred ultrahigh molecular weight polyethylene(UHMWPE).The weight-average molecular weight of ultrahigh molecular weight polyethylene(UHMWPE) preferred 5 * 10 5Or 5 * 10 5More than, be more preferably 1 * 10 6~15 * 10 6Scope in, preferred especially 1 * 10 6~5 * 10 6Scope in.
When polyethylene is one matter or the composition that is made of two or more polyethylene any, the ratio Mw/Mn (molecular weight distribution) of its weight-average molecular weight (Mw) and number-average molecular weight (Mn) is also unqualified, but in preferred 5~300 the scope, be more preferably in 10~100 the scope.In order to adjust molecular weight distribution, can prepare polyethylene by multi-stage polymeric.But, be not the polyethylene that is defined in multi-stage polymeric, certainly, also can use the polyethylene of one-step polymerization.
As polyolefin compositions, preferably be the composition of necessary composition with the polyethylene, being more preferably with above-mentioned ultrahigh molecular weight polyethylene(UHMWPE) is the composition of necessary composition.With above-mentioned ultrahigh molecular weight polyethylene(UHMWPE) serve as must composition polyolefin compositions preferably contain and be selected from least a in high density polyethylene(HDPE), medium-density polyethylene and the new LDPE (film grade), be more preferably and contain high density polyethylene(HDPE).The weight-average molecular weight of these high density polyethylene(HDPE)s, medium-density polyethylene and new LDPE (film grade) preferred 1 * 10 4~less than 5 * 10 5
In the composition that with above-mentioned ultrahigh molecular weight polyethylene(UHMWPE) serves as necessary composition, the weight-average molecular weight that is selected from that can add as any composition is 1 * 10 4~4 * 10 6Polypropylene, weight-average molecular weight in the scope are 1 * 10 4~4 * 10 6Polybutene-1, weight-average molecular weight in the scope are 1 * 10 3~~4 * 10 4Polyethylene wax and weight-average molecular weight in the scope are 1 * 10 4~4 * 10 6At least a polyolefine in the ethylene in the scope.With polyolefin compositions all as 100 mass parts, preferred 80 mass parts of these polyolefinic additions that can add arbitrarily or below 80 mass parts.
[2] manufacture method of thermoplastic resin micro-porous film
Any of first and second kinds of manufacture method of the present invention all comprises: (1) carries out melting mixing after adding in the above-mentioned thermoplastic resin with solvent film forming, preparation thermoplastic resin solution's operation; (2), and cool off and the operation of formation gel forming composition by die orifice extruding thermoplastic resins solution; (3) by cleaning with the film forming of solvent the operation of removing with solvent; And (4) remove the operation of cleaning with solvent from the film that obtains.Optionally, can also the operation of (3) before or after, stretching process be set.Can also after the operation of (1)~(4), the operation of desciccator diaphragm, the crosslinking Treatment operation of passing through ionizing radiation, heat treatment step, hydrophilicity-imparting treatment operation, surface-coated treatment process etc. be set.Below, successively first and second kinds of manufacture method are described.
(A) first kind of manufacture method
(1) thermoplastic resin solution's preparation process
At first, in thermoplastic resin, add suitable film forming with solvent after, carry out melting mixing, the preparation thermoplastic resin solution.In the scope of not damaging effect of the present invention, can in the thermoplastic resin solution, add various additives such as oxidation inhibitor, UV light absorber, antiblocking agent, pigment, dyestuff, inorganic filling material.For example, can add micro mist silicic acid as the hole forming agent.
As the film forming solvent, can use any in liquid solvent and the solid solvent.As liquid solvent, can enumerate fat group or ring type hydrocarbon and boiling point and these corresponding Dormant oils cuts such as nonane, decane, naphthane, p-Xylol, hendecane, 12 carbon alkane, whiteruss.In order to obtain solvent amount stable gel shape forming composition, preferably use the liquid solvent of non-volatilities such as whiteruss.The preferred fusing point of solid solvent is the material below 80 ℃ or 80 ℃, as such solid solvent, can enumerate paraffin, ceryl alcohol, stearyl alcohol, dicyclohexyl phthalate etc.Can also use liquid solvent and solid solvent simultaneously.
The viscosity of liquid solvent preferably is in the scope of 30~500cSt, to be more preferably in the scope of 50~200cSt under 25 ℃ temperature.During this viscosity deficiency 30cSt, the thermoplastic resin solution is from the heterogeneity that spues of die orifice, and mixing difficulty.On the other hand, when surpassing 500cSt, be difficult to remove liquid solvent.
The melting mixing method is not particularly limited, but preferably carries out mixing method equably in forcing machine.This method is suitable for preparing the highly concentrated solution of thermoplastic resin.In the scope of the fusing point of melt temperature preferred thermoplastic resin+10 ℃~+ 100 ℃.Particularly, in preferred 140~230 ℃ scope of melt temperature, be more preferably in 170~200 ℃ the scope.At this, said fusing point is meant the K7121 based on JIS, the value of obtaining by differential scanning calorimetric measurement (DSC).Film forming can be added before mixing beginning with solvent, also can add from the way of forcing machine in mixing, but preferably add and carry out in advance solubilisate before mixing beginning.When melting mixing,, preferably add oxidation inhibitor in order to prevent the oxidation of thermoplastic resin.
Among the thermoplastic resin solution, thermoplastic resin and film forming be with the cooperation ratio of solvent, and as 100 quality %, thermoplastic resin is 1~50 quality %, preferred 20~40 quality % with both total amount.If the ratio deficiency of thermoplastic resin 1 quality %, in extruding thermoplastic resins solution, the width of cloth phenomenon that expands or contract in the mould exit becomes big, the formability of gel forming composition and self-supporting reduction.On the other hand, if the ratio of thermoplastic resin surpasses 50 quality %, the formability of gel forming composition reduces.
(2) the gel forming composition forms operation
After extruding the thermoplastic resin solution of melting mixing or temporarily cool off and carry out granulationization from the mouth mould directly or by other forcing machine from forcing machine, extrude from the mouth mould by forcing machine once more.As die orifice, use usually and make the sheet die orifice of rectangular tube head shape, but also can use two layers of hollow form die orifice cylindraceous, expansion die orifice etc.When sheet was used die orifice, the slit of die orifice was generally in the scope of 0.1~5mm, heats under 140~250 ℃ temperature when extruding.In the scope that the preferred 0.2~15m/ of the extruded velocity of heated solution divides.
Solution cooling by extruding from die orifice like this forms the gel forming composition.Preferably be cooled to gelling temperature at least or below the gelling temperature with the speed more than 50 ℃/minute or 50 ℃/minute.By carrying out such cooling, thermoplastic resin can have been carried out the structure immobilization that is separated of microphase-separated with solvent by film forming.Cooling preferably proceeds to below 25 ℃ or 25 ℃.Usually, if speed of cooling is slack-off, it is big that the false cell unit becomes, the hyperstructure chap of the gel forming composition that obtains, and if speed of cooling accelerates, then become fine and close cell unit.If 50 ℃/minute of speed of cooling less thaies, the crystallization degree rises, and is difficult to become suitable tensile gel forming composition.As method of cooling, the method that can use contacts, the method that contacts with cooling roller etc. with cold medium such as cold wind, water coolant.
(3) film forming is removed operation with solvent
From above-mentioned gel forming composition, remove the film forming solvent.In order to remove the film forming solvent, can use (a) the surface tension under 25 ℃ the temperature as 24mN/m or below the 24mN/m, (b) boiling point under atmospheric pressure is below 100 ℃ or 100 ℃, (c) under 16 ℃ temperature to the solubleness of water as 600ppm (quality criteria) or below the 600ppm, and with thermoplastic resin immiscible clean with solvent (below, only otherwise specify, be called " clean and use solvent orange 2 A ").
To clean with the surface tension of solvent under 25 ℃ temperature be 24mN/m or below the 24mN/m by making, can make to clean to diminish, and can suppress the contraction densification that warm water is removed the reticulattion that causes when cleaning with solvent of passing through in following stage with the surface tension between solvent and the micro-pore wall.Therefore, can improve the hole rate and the perviousness of micro-porous film.In present specification, so-called " surface tension " is meant the tension force that produces on the interface of gas and liquid, is based on the value that JIS K 3362 measures.Clean with the preferred 20mN/m of the surface tension of solvent orange 2 A under 25 ℃ temperature or below the 20mN/m.Though clean surface tension with solvent orange 2 A along with the rising of use temperature step-down, use to clean in boiling point or the temperature range below the boiling point usually and use solvent orange 2 A.
Is below 100 ℃ or 100 ℃ by making clean with solvent boiling point under atmospheric pressure, can promptly remove to clean by warm water and use solvent.If this boiling point surpasses 100 ℃, cleaning with removing of solvent needs for a long time, and it is low to make efficient.If cleaning needs for a long time with removing of solvent, be 24mN/m or below the 24mN/m, owing to heating for a long time by warm water, therefore, hole rate and perviousness also are inadequate even clean with the surface tension of solvent under 25 ℃ temperature.Clean preferred below 80 ℃ or 80 ℃ with solvent orange 2 A boiling point under atmospheric pressure.
To clean with solvent be 600ppm (quality criteria) or below the 600ppm to the solubleness of water under 16 ℃ temperature by making, and can prevent from removing the clean washmarking (bullate vestige) that forms during with solvent by warm water on micro-porous film.The preferred 300ppm of this solubleness (quality criteria) or below the 300ppm.Clean and uprise along with the rising of use temperature with the solubleness of solvent orange 2 A to water., as long as solubleness 16 ℃ under is 600ppm (quality criteria) or below the 600ppm, just the clean washmarking that forms during with solvent can not removed on micro-porous film by warm water.
As the object lesson of cleaning with solvent orange 2 A, can enumerate, for example fluoride compound, carbonatomss such as hydrofluoroalkane, hydrogen fluorine ether, perfluor alkane, perfluor ether are that 5~7 n-paraffin, carbonatoms are that 5~7 isoparaffin, carbonatoms are naphthenic hydrocarbon of 5~7 etc.
As fluoride compound, be preferably selected from, for example composition formula C 5H 2F 10Chain hydrofluoroalkane, for example composition formula C of expression 4F 9OCH 3And C 4F 9OC 2H 5Hydrogen fluorine ether, for example composition formula C of expression 6F 14And C 7F 16Perfluor alkane, for example composition formula C of expression 4F 9OCF 3And C 4F 9OC 2F 5The expression perfluor ether at least a.These fluoride compounds even they are dispersed into outside the manufacturing system, also can reduce the load to environment owing to there is not ozone layer destroying.In addition, because the flash-point of these fluoride compounds is (a part of compound does not have flash-point) more than 40 ℃ or 40 ℃, therefore, the dangerous low of blast of igniting.
As carbonatoms is 5~7 n-paraffin, can enumerate Skellysolve A, normal hexane and normal heptane, but preferred Skellysolve A.It as carbonatoms 5~7 isoparaffin, can enumerate 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl hexane, 3-methyl hexane, 3-ethylpentane, 2,2-dimethylpentane, 2,3-dimethylpentane, 2,4-dimethylpentane, 3,3-dimethylpentane, triptane etc.As carbonatoms is 5~7 naphthenic hydrocarbon, can enumerate pentamethylene, hexanaphthene and methylcyclopentane, but preferred surface tension under 20 ℃ temperature is 24mN/m or the pentamethylene below the 24mN/m.
As cleaning in the compound enumerate with the example of solvent orange 2 A, be shown in Table 1 with the surface tension of representational material, boiling point with to the solubleness of water.
[table 1]
Composition formula or compound name Surface tension (25 ℃) (mN/m) Boiling point (normal atmosphere) (℃) Solubleness (ppm (quality criteria)) to water
C 4F 9OCH 3 14 61 12(25℃)
C 4F 9OC 2F 5 17 76 <20(25℃)
C 6F 14 12 56 ≤100(25℃)
Skellysolve A 16 36 225(16℃)
Normal hexane 18 68.7 13(16℃)
Normal heptane 20 98.4 Do not dissolve
Pentamethylene 22 49.3 142(16℃)
Hexanaphthene 24 80.7 52(16℃)
Can suitably select to clean to use solvent orange 2 A with solvent corresponding to film forming.Cleaning with solvent orange 2 A both can be the material of single composition, also can be by a plurality of mixtures that constitute with solvent orange 2 A of cleaning.As long as clean the condition that satisfies above-mentioned (a)~(c) with solvent orange 2 A, can also contain other solvent of any one condition of not satisfying above-mentioned (a)~(c).As such mixture, for example can use, being selected from above-mentioned fluoride compound, above-mentioned carbonatoms is that 5~7 n-paraffin, above-mentioned carbonatoms are that 5~7 isoparaffin and above-mentioned carbonatoms are in the middle of at least a in 5~7 the naphthenic hydrocarbon, adds for example composition formula C on a small quantity 5H 3F 7The cycloalkyl hydroperoxide fluothane of expression or boiling point are the fatty ether, aliphatic ketone, fatty alcohol, aliphatic ester below 100 ℃ or 100 ℃ etc.Use the different clean solvent orange 2 As of using, can clean by two-stage or the operation more than the two-stage.
Before use cleaning, can remove the film forming solvent with solvent (below, unless otherwise specified, be called " clean and use solvent B ") by cleaning with clean beyond the solvent orange 2 A with solvent orange 2 A.By the clean solvent B and clean with the two-stage of solvent orange 2 A or the clean operation more than the two-stage that uses that use is suitably selected with solvent corresponding to film forming, clean effect further improves.Use solvent orange 2 A by using to clean, can remove the clean solvent B that uses of stage use in front, and can prevent the contraction densification that warm water is removed the reticulattion that causes when cleaning with solvent of passing through in following stage in the terminal stage of cleaning operation.Below, will remove film forming with solvent B and be called " washing processing " with cleaning by cleaning with the solvent orange 2 A processing with the formed body of solvent.
Clean with solvent B so long as the material that does not have an intermiscibility for thermoplastic resin gets final product, can enumerate, for example non-water solvents such as hydrochloric ether, hydrofluoric ether, paraffinic compound, aromatic hydrocarbon, alcohol, ester, ether, ketone.
In the above-mentioned non-water solvent, as removing for example solvent of film forming usefulness solvent, hydrochloric ethers such as preferred common methylene dichloride, tetracol phenixin; Hydrofluoric ethers such as Halothane; Skellysolve A; Ethers such as ether, diox; Methylethylketone etc.
The preferred example of other of above-mentioned non-water solvent is under the arbitrary temp below 80 ℃ or 80 ℃, and surface tension is 24mN/m or the following solvent of 24mN/m.If use so non-water solvent, even the film of non-water solvent when cleaning more the evaporable occasion also can suppress film and shrink.As so non-water solvent, can enumerate, for example Skellysolve A, hexane, heptane, Halothane, ether, 2-methylpentane, 3-methylpentane, hexanaphthene, pentamethylene, acetone, methylethylketone etc.
The other preferred example of above-mentioned non-water solvent be that under atmospheric pressure boiling point is more than 100 ℃ or 100 ℃, and flash-point is the solvent more than 0 ℃ or 0 ℃.Non-water solvent like this is difficult volatile, and is low to the load of environment, and therefore the dangerous low of blast of igniting, be safe in the use.In addition, owing to be high boiling, recycling is easily reclaimed easily in cohesion easily.Here, so-called " flash-point " is meant the value of measuring based on JIS K 2265.Above-mentioned flash-point is preferred more than 5 ℃ or 5 ℃, is more preferably more than 40 ℃ or 40 ℃.
As boiling point is more than 100 ℃ or 100 ℃, and flash-point is the non-water solvent more than 0 ℃ or 0 ℃, is preferably selected from carbonatoms and is the n-paraffin more than 8 or 8, the carbonatoms that at least a portion of hydrogen atom is replaced by halogen atom is the n-paraffin more than 5 or 5, carbonatoms is the isoparaffin more than 8 or 8, carbonatoms is the naphthenic hydrocarbon more than 7 or 7, the carbonatoms that at least a portion of hydrogen atom is replaced by halogen atom is the naphthenic hydrocarbon more than 5 or 5, carbonatoms is the aromatic hydrocarbons more than 7 or 7, the carbonatoms that at least a portion of hydrogen atom is replaced by halogen atom is the aromatic hydrocarbons more than 6 or 6, the carbonatoms that the part of hydrogen atom is replaced by halogen atom is 5~10 alcohol, the carbonatoms that the part of hydrogen atom is replaced by halogen atom is 5~14 ester, the carbonatoms that the part of hydrogen atom is replaced by halogen atom is 4~14 ether, and carbonatoms is at least a in 5~10 the ketone.
As carbonatoms is n-paraffin more than 8 or 8, and preferred octane, positive nonane, n-decane, positive hendecane, positive 12 carbon alkane are more preferably octane, positive nonane and n-decane.
The carbonatoms that is replaced by halogen atom as at least a portion of hydrogen atom is the n-paraffin more than 5 or 5, preferred 1-chloropentane, 1-chlorohexane, 1-chloroheptane, 1-chloro-octane, 1-bromo pentane silane, hexyl bromide 1 bromohexane, 1-heptyl bromide, 1-bromooctane, 1,5-dichloropentane, 1,6-dichloro hexane and 1,7-two chloroheptanes are more preferably 1-chloropentane, 1-chlorohexane, 1-bromo pentane silane and hexyl bromide 1 bromohexane.
As carbonatoms is isoparaffin more than 8 or 8, preferred 2,3,4-trimethylpentane, 2,2,3-trimethylpentane, 2,2,5-trimethyl cyclohexane, 2,3,5-trimethyl cyclohexane, 2,3,5-trimethylammonium heptane and 2,5,6-trimethylammonium octane is more preferably 2,3,4-trimethylpentane, 2,2,2,5-trimethyl cyclohexane and 2,3, the 5-trimethyl cyclohexane.
As carbonatoms is naphthenic hydrocarbon more than 7 or 7, preferred suberane, cyclooctane, methylcyclohexane, suitable-and anti--1,2-dimethyl cyclohexane, suitable-and anti--1,3-dimethyl cyclohexane and suitable-and anti--1, the 4-dimethyl cyclohexane is more preferably methylcyclohexane.
The carbonatoms that is replaced by halogen atom as at least a portion of hydrogen atom is the naphthenic hydrocarbon more than 5 or 5, and preferred chlorocyclopentane and chlorocyclohexane are more preferably chlorocyclopentane.
As carbonatoms is aromatic hydrocarbons more than 7 or 7, and preferred toluene, o-Xylol, m-xylene and p-Xylol are more preferably toluene.
The carbonatoms that is replaced by halogen atom as at least a portion of hydrogen atom is the aromatic hydrocarbons more than 6 or 6, preferred chlorobenzene, 2-toluene(mono)chloride, 3-toluene(mono)chloride, 4-toluene(mono)chloride, 3-chloro-o-xylene, 4-chloro-o-xylene, 2-chloro-m-xylene, 4-chloro-m-xylene, 5-chloro-m-xylene and 2-chloro-p-xylene, preferred chlorobenzene, 2-toluene(mono)chloride, 3-toluene(mono)chloride and 4-toluene(mono)chloride.
The carbonatoms that is replaced by halogen atom as the part of hydrogen atom is 5~10 alcohol, preferred primary isoamyl alcohol, tertiary amyl alcohol, cyclopentanol, hexalin, 3-methoxyl group-1-butanols, 3-methoxyl group-3-methyl isophthalic acid-butanols, propylene glycol n-butyl ether and 5-chloro-1-amylalcohol are more preferably 3-methoxyl group-1-butanols, 3-methoxyl group-3-methyl isophthalic acid-butanols, propylene glycol n-butyl ether and 5-chloro-1-amylalcohol.
The carbonatoms that is replaced by halogen atom as the part of hydrogen atom is 5~14 ester, preferred diethyl carbonate, ethyl maleate, n-propyl acetate, n-butyl acetate, Isoamyl Acetate FCC, acetate 3-methoxyl group butyl ester, acetate 3-methoxyl group-3-methyl butyl ester, butanic acid ethyl ester, ethyl n-valerate, acetate 2-chloroethene ester are more preferably Isoamyl Acetate FCC, acetate 3-methoxyl group butyl ester, acetate 3-methoxyl group-3-methyl butyl ester, butanic acid ethyl ester and acetate 2-chloroethene ester.
The carbonatoms that is replaced by halogen atom as the part of hydrogen atom is 4~14 ether, and preferred dipropylene glycol dme, n-butyl ether, ethyl isobutyl ether and Dichloroethyl ether are more preferably dipropylene glycol dme and Dichloroethyl ether.
As carbonatoms is 5~10 ketone, and preferred 2 pentanone, propione, methyl-n-butyl ketone, 3-hexanone, cyclopentanone and pimelinketone are more preferably 2 pentanone and propione.
Clean and suitably to select with solvent corresponding to film forming with solvent B.Cleaning with solvent B can be the material of single composition, also can be by the multiple clean mixture that constitutes with solvent B.In addition, as any composition C, can also add being selected from, for example composition formula C 5H 2F 10Chain hydrofluoroalkane, for example composition formula C of expression 4F 9OCH 3And C 4F 9OC 2H 5Hydrogen fluorine ether, for example composition formula C of expression 5H 3F 7Cycloalkyl hydroperoxide fluothane, for example composition formula C of expression 6F 14And C 7F 16The perfluor alkane of expression and composition formula C for example 4F 9OCF 3And C 4F 9OC 2F 5At least a solvent in the perfluor ether of expression.Clean with solvent B by containing, can reduce the load of environment and the danger of igniting and exploding as above-mentioned any composition C.The amount of any composition C, all as 100 mass parts, preferred 2~98 mass parts are more preferably 5~50 mass parts with mixed solvent.Particularly, if clean with solvent B and any composition C being that 24mN/m or the ratio below the 24mN/m are mixed at the lower surface of the temperature arbitrarily tension force below 80 ℃ or 80 ℃, even when clean, clean with solvent morely when film volatilizees, also can suppress the film contraction.
Conduct below is shown at the clean solvent B of using of the fs use of cleaning operation and the clean preferred material of combination of using solvent orange 2 A that uses in subordinate phase.As combination, can enumerate, for example clean and clean with solvent orange 2 A=methylene dichloride/C with solvent B/ 4F 9OCH 3, methylene dichloride/C 4F 9OC 2H 5, methylene dichloride/C 6F 14, methylene dichloride/C 7F 16, methylene dichloride/normal heptane, methylene dichloride/normal hexane, ether/hydrogen fluorine ether, n-paraffin/hydrogen fluorine ether, isoparaffin/hydrogen fluorine ether, naphthenic hydrocarbon/hydrogen fluorine ether and ketone/hydrogen fluorine ether.In the middle of the aforesaid combination, preferably clean and clean with solvent orange 2 A=methylene dichloride/C with solvent B/ 4F 9OCH 3, methylene dichloride/C 4F 9OC 2H 5, methylene dichloride/C 6F 14, methylene dichloride/C 7F 16, methylene dichloride/normal heptane, methylene dichloride/normal hexane, normal heptane/C 4F 9OCH 3, and normal heptane/C 6F 14But, do not limit to clean with the two-stage and carry out.
Independent or clean by cleaning with solvent orange 2 A and clean with cleaning that the combination of solvent B is carried out with solvent orange 2 A, optionally also can be three stages or the operation more than three stages.The clean hop count of such operation is not particularly limited, and is generally for three stage~sevens' stages, preferred three~quadravalence section.
Cleaning of gel forming composition can be by cleaning method with solvent, the gel forming composition being immersed in cleaning with the method in the solvent, pass through the method etc. of these combination to the drip washing of gel forming composition.These are cleaned to handle preferably and carry the gel forming composition to carry out continuously or intermittently on one side on one side.As the e Foerderanlage of gel forming composition, use common roller.Carry the gel forming composition to be immersed on one side continuously on one side and clean when using in the solvent, make the gel forming composition by cleaning with in the bath of solvent.Carry the gel forming composition to be immersed on one side intermittently on one side and clean when using in the solvent, the clean position of the gel forming composition that preferably will temporarily stop to be immersed in to be cleaned with in the solution bath, and shakes with the vibration number about 100rpm.When shaking the gel forming composition, preferably will clean the position around be fixed on the deckle board etc.
Clean with solvent orange 2 A and clean usage quantity,, preferably be respectively 300~30000 mass parts with respect to gel forming composition 100 mass parts with solvent B.Use to clean with solvent orange 2 A and clean with solvent B and by two-stage or two-stage during above operation treatment gel shape forming composition, will clean usage quantity with solvent B as 100 mass parts, preferably making the usage quantity of cleaning with solvent orange 2 A is 50~200 mass parts.Clean and preferably to proceed to the film forming that remains in the gel forming composition and reach for its addition with solvent phase and be lower than 1 quality %.
The use temperature of cleaning with solvent orange 2 A depends on its surface tension.Particularly, be that 24mN/m or the temperature below the 24mN/m or this use more than temperature preferably cleaning surface tension with solvent orange 2 A.Clean with solvent orange 2 A because under paramount 25 ℃ temperature, its surface tension is 24mN/m or below the 24mN/m, therefore, generally at room temperature uses.Optionally can also heat cleaning with solvent orange 2 A.
The use temperature of cleaning with solvent B depends on its boiling point.Be generally in 20~80 ℃ the scope.When cleaning boiling point with solvent B and be below 150 ℃ or 150 ℃, can at room temperature clean, optionally can heat the clean solvent B that uses.When clean boiling point with solvent B surpasses 150 ℃, use the poor permeability of solvent B to film inside owing at room temperature clean, therefore, preferred heating is cleaned and is used solvent B.
(4) clean and to remove operation with solvent
By removing the remaining clean solvent orange 2 A of using in the forming composition of warm water after clean (below, only otherwise specify, be called " cleaning forming composition ").Clean with outflow and/or the volatilization of solvent orange 2 A from clean forming composition by using warm water as the medium of cleaning with solvent orange 2 A of removing, promptly causing.Therefore, compare, can very rapidly remove to clean and use solvent orange 2 A, and improve and make efficient with the situation of using warm wind.Because cleaning of extracting mainly is diffused in the warm water with solvent orange 2 A, therefore,, can suppress to clean the volatilization of using solvent orange 2 A by the warm water that will pollute frequency and the exchange of untapped warm water with appropriateness from clean forming composition.
The lower limit temperature of warm water is more preferably boiling point or more than the boiling point preferably more than the clean boiling point-5 with solvent orange 2 A that will remove ℃ or boiling point-5 ℃, more than preferred especially boiling point+3 ℃ or boiling point+3 ℃.Lower limit temperature by making warm water can promptly be removed to clean and use solvent orange 2 A for more than the clean boiling point-5 with solvent orange 2 A that will remove ℃ or the boiling point-5 ℃.The crystallization dispersion temperature of the ceiling temperature preferred thermoplastic resin of warm water or below it is more preferably below crystallization dispersion temperature-5 ℃ or the crystallization dispersion temperature-5 ℃.If make the ceiling temperature of warm water surpass the crystallization dispersion temperature, the danger of resin remollescent arranged.As mentioned above, for example, poly crystallization dispersion temperature is generally 90 ℃.At the crystallization dispersion temperature of thermoplastic resin is more than 95 ℃ or 95 ℃ the time, and for the steam vapour amount that suppresses to produce from warm water, the temperature that preferably makes warm water is below 95 ℃ or 95 ℃, is more preferably below 85 ℃ or 85 ℃.
The duration of contact of cleaning forming composition and warm water is preferred below 15 seconds or 15 seconds.Because the boiling point of cleaning with solvent orange 2 A is below 100 ℃ or 100 ℃, therefore, common situation following duration of contact is to be exactly sufficient below 15 seconds or 15 seconds.
From clean forming composition, remove clean with solvent orange 2 A can by with the method for the clean forming composition of warm water drip washing, will clean forming composition and be immersed in method in the warm water, wait by these the method for combination and carry out.These remove processing, Yi Bian on one side the preferred method that forming composition is carried out of cleaning of carrying continuously or intermittently.Warm water amount when cleaning forming composition drip washing warm water, preferred 50~5000ml/m 2, be more preferably 100~2000ml/m 2If the warm water quantity not sufficient 50ml/m of drip washing 2, for clean forming composition, drip washing warm water equably, on the other hand, if surpass 5000ml/m 2, it is difficult that the cycle control of warm water becomes.In the time of will cleaning forming composition and be immersed in the warm water, preferably spray warm water to cleaning with forming composition in warm water bath, thus, the extraction rate of cleaning with solvent orange 2 A accelerates more, and cleanly spreading easily in warm water with solvent orange 2 A of extracting.As the means of spraying warm water, can enumerate for example nozzle.
Carry continuously on one side and clean when handling with warm water on one side, preferably use roller and drip washing to clean the forming composition volume and hang over part on the roller, perhaps clean the part that the forming composition volume hangs on the roller and be immersed in the warm water to the major general with forming composition.By such treatment process, roller is heated by warm water, uses forming composition thereby can promptly heat to clean, and therefore, the speed of cleaning with solvent orange 2 A of removing becomes faster.Also warming mill internally optionally.The crystallization dispersion temperature of the Heating temperature preferred thermoplastic resin of roller or below the crystallization dispersion temperature is more preferably below crystallization dispersion temperature-5 ℃ or the crystallization dispersion temperature-5 ℃.
Preferred 3~the 100cm of the diameter of roller is more preferably 5~30cm.During this diameter deficiency 3cm, the contact area of cleaning forming composition and roller is little, and the heat of roller can not be transmitted to fully to be cleaned on the forming composition, and on the other hand, if surpass 100cm, equipment too maximizes.Carry clean forming composition to remove the transfer rate of cleaning when using solvent orange 2 A on one side on one side continuously, from making the viewpoint of efficient, preferred 0.5~80m/min is more preferably 1~50m/min.Roller usually with 1 for well, optionally also can be a plurality of.
When carrying clean forming composition to be immersed in the warm water on one side on one side intermittently, preferably in warm water, shake the solvent of cleaning forming composition and remove the position.When shaking, preferably remove the position, and shake with for example vibration number about 100rpm with fixing solvents of cleaning forming composition such as deckle boards.
With dried film quality is 100 quality %, and preferably using warm water to make clean amount with solvent remaining in the thermoplastic resin micro-porous film is 5 quality % or below the 5 quality %, is more preferably 3 quality % or below the 3 quality %.A large amount of remaining clean when use solvent in film owing to remove insufficient, hole rate reduces when the thermal treatment of back, and so the perviousness deterioration is not preferred.
(5) drying process
To remove clean film by aeration drying, heat drying method etc. and carry out drying with solvent.Because the affinity of water and micro-porous film is low, be blown into warm wind by the film after warm water is handled, can remove easily and promptly.The crystallization dispersion temperature of drying temperature preferred polyolefm or its following temperature are especially preferably than the low temperature more than 5 ℃ or 5 ℃ of crystallization dispersion temperature.
(6) stretching process
Remove before the operation with solvent and/or stretch afterwards if necessary in the film forming of above-mentioned (3).Stretching is more preferably at film forming and removes with solvent and carry out before the operation.Stretching can stretch the combination of gel forming composition heating back by common tentering method, roller method, inflation process, rolling process or these methods with the multiplying power of stipulating.Stretching can be that unilateral stretching also can be two-way stretch, but preferred two-way stretch.During two-way stretch, can be two-way stretch simultaneously or any mode of tensile successively, but preferred two-way stretch simultaneously.Improve physical strength by stretching.
Stretching ratio is according to the thickness of gel forming composition and difference, but preferably stretches when unilateral stretching more than 2 times or 2 times, is more preferably 3~30 times.When two-way stretch, by stretching more than at least 3 times or 3 times on the direction arbitrarily, that is, the area multiplying power is more than 9 times or 9 times, can improve bur intensity, so preferred.During 9 times of area multiplying power less thaies, it is insufficient to stretch, and can not obtain snappiness and high-intensity thermoplastic resin micro-porous film.On the other hand, if the area multiplying power surpasses 400 times, produce restriction at aspects such as stretching device, stretched operations.
Below the fusing point of draft temperature preferred thermoplastic resin+10 ℃ or fusing point+10 ℃, be more preferably from the crystallization dispersion temperature in the scope that is lower than crystalline melt point.If draft temperature surpasses fusing point+10 ℃, the resin fusion can not be carried out the orientation by the tensile molecular chain.In addition, during draft temperature is not enough crystallization dispersion temperature, resin softening insufficient, by the easy rupture of membranes that stretches, can not the stretching of high magnification ground.In the present invention, making draft temperature usually is in 100~140 ℃ the scope, is more preferably in 110~120 ℃ the scope.Here said crystallization dispersion temperature is meant based on ASTM D 4065 and measures the value of trying to achieve by the temperature profile of dynamic viscoelastic.
(7) crosslinking Treatment operation
For the exsiccant micro-porous film, preferably implement crosslinking Treatment by ionizing radiation.As ionizing radiation, can use alpha-ray, β ray, gamma-rays, electron rays etc.By the crosslinking Treatment of ionizing radiation, can be undertaken by the electron rays amount of 0.1~100Mrad and the acceleration voltage of 100~300kV.By crosslinking Treatment temperature of fusion is improved.
(8) heat treatment step
The clean film with solvent of preferably will having gone out is heat-treated.By thermal treatment, the crystallization-stableization of micro-porous film, laminated layer homogenization.As heat treating method, can use any method in thermal stretch processing, heat-set treatment or the thermal contraction processing, these methods can suitably be selected corresponding to the desired rerum natura of micro-porous film.These thermal treatments are carried out under the fusing point of polyolefin micro porous polyolefin membrane or the temperature below the fusing point, preferably carry out in the temperature range of 60 ℃~fusing point-10 ℃.
Thermal stretch is handled and is undertaken by normally used tentering mode, roller mode or calendering mode, preferably carries out at the stretching ratio of at least one direction with 1.01~2.0 times, and the stretching ratio that is more preferably with 1.01~1.5 times carries out.
Heat-set treatment is undertaken by tentering mode, roller mode or calendering mode.Thermal contraction is handled and is undertaken by tentering mode, roller mode or calendering mode, perhaps also can use endless belt conveyor or unsteady (Off ロ one テ イ Application グ) to carry out.Thermal contraction is handled and is preferably being carried out in the scope below 50% or 50% at least one direction, and the scope that is more preferably at below 30% or 30% is carried out.
Also can make up a plurality of above-mentioned thermal stretch processing, heat-set treatment and thermal contractions handles and carries out.Particularly, handle, can obtain low-shrinkage and high-intensity micro-porous film, so preferred if after thermal stretch is handled, carry out thermal contraction.
(9) hydrophilicity-imparting treatment operation
Can implement hydrophilicity-imparting treatment to having removed clean film with solvent.As hydrophilicity-imparting treatment, use monomer-grafted processing, tensio-active agent processing, Corona discharge Treatment etc.Monomer-grafted processing is preferably carried out behind ionizing radiation.
As tensio-active agent, can use any in nonionic surface active agent, cats product, anion surfactant or the zwitterionics, but preferably use nonionogenic tenside.When using tensio-active agent, tensio-active agent can be made the aqueous solution, make the solution of lower alcohols such as methyl alcohol, ethanol, Virahol, flood then or use the method for scraper that micro-porous film is carried out hydrophilization.
The hydrophilization micro-porous film that obtains is carried out drying.When drying, improve in order to make perviousness, preferably prevent that in the fusing point of polyolefin micro porous polyolefin membrane or the temperature bottom below the fusing point contraction edge from heat-treating.As while preventing to shrink the method for heat-treating, for example can enumerate the hydrophilization micro-porous film is implemented the method that above-mentioned thermal stretch is handled.
(10) surface-coated treatment process
Clean the micro-porous film that obtains with solvent by removing, by coat fluorine-type resin porous material or porous materials such as polyimide, polyphenylene sulfide such as polyvinylidene difluoride (PVDF), tetrafluoroethylene on the surface, can improve the melting characteristic when using as battery separator.In addition, clean the micro-porous film that obtains with solvent by removing, is 0.12~0.88 polypropylene film by form raceme on the surface to the mark of (2 monomeric units that link to each other are the structural unit of mirror each other), the hot properties raising when using as battery separator.
(B) second kind of manufacture method
Second kind of manufacture method, with respect to first kind of manufacture method, except (i) removes in the operation cleaning of using with solvent this point and (ii) removing in the operation with solvent cleaning without limits with solvent in film forming, so that clean the forming composition contact for the state of cleaning with the poor solvent of solvent, by suction unit poor solvent is removed by clean forming composition and cleaned with beyond this some difference of solvent, other operation all is identical.Therefore, only film forming is removed operation with solvent below and clean and remove operation with solvent and describe.
(1) film forming is removed operation with solvent
In second kind of manufacture method operable clean with solvent so long as with the immiscible solvent of thermoplastic resin, then be not particularly limited.Can use for example above-mentioned clean with solvent orange 2 A and B.Use is cleaned can be same as described above with the method for cleaning of solvent orange 2 A and B.
(2) clean and to remove operation with solvent
Make and clean forming composition and, make poor solvent remove the clean solvent of using by cleaning forming composition by suction unit for above-mentioned clean poor solvent state of contact with solvent.To clean when aspirating simultaneously, and make t duration of contact (second) that cleans forming composition and suction unit satisfy following general formula with solvent and poor solvent
(1):
t≤(100-T) 3/(1100×P 0.5×logL)...(1)
[in the formula, T represent poor solvent temperature (℃), P represents swabbing pressure (kPa), L represents the size (diameter of the maximum inscribed circle of above-mentioned open-work (μ m)) of the open-work of suction unit] scope.If duration of contact, t surpassed above-mentioned scope, because the suction force of suction unit, the film distortion perhaps forms the suction vestige on the film surface, and thus, the outward appearance of film worsens.According to circumstances physics value such as Gas permeability, hole rate also worsens sometimes.From cleaning the viewpoint of removing with solvent fully, in the scope that satisfies above-mentioned general formula (1), duration of contact, t was preferred more than 0.05 second or 0.05 second, was more preferably more than 0.2 second or 0.2 second.
As suction unit, can enumerate suction roll, suction band etc., but preferred suction roll.By using suction roll, carry the gel forming composition with solvent while can aspirate to clean at its periphery.In addition, owing to can give tension force, can suppress film and shrink cleaning forming composition.If be not accompanied by suction, owing to clean pneumatolysis, for the tension force of the cleaning forming composition heterogeneity that becomes easily with solvent only with the dry forming composition of cleaning of warming mill.If the use suction roll owing to can promptly remove the clean solvent of using that gasifies because of heating, even improve transfer rate, also can be kept cleaning the tension force with forming composition.
Suction roll is not particularly limited, can enumerate, for example possess (i) have in the inboard can vacuum-load hole portion, have the tubular axle body of a plurality of open-works that are communicated with hole portion and (ii) be arranged on the two ends of body shaft at side face, and offered the pair of side plates of the communicating pores that is communicated with hole portion and (iii) offered the suction roll of pair of bearings portion of the communicating pores of the communicating pores that has been communicated with side plate at least one end.Hole portion is by using vacuum pump suction the becoming decompression that is communicated with by pipe arrangement from the communicating pores of bearing portion, suction roll can be by motor while rotating at its periphery pumping liquid and gas.As suction roll, for example can use No. the 2630870th, patent, No. the 2899226th, patent, spy open clear 63-247251 number, spy open clear 63-267648 number, spy open flat 4-260561 number, spy open flat 8-133536 number, spy open flat 8-208100 number, spy open flat 9-67053 number, spy open flat 2002-160857 number, spy open 2002-255423 number etc. in disclosed suction roll.
Wherein, as suction roll, be preferably selected between the space between metal wire etc. the formation open-work wire roll, form the slit roller (ス リ Star ト ロ one Le) of slot-shaped open-work and formed at least a in the perforated punching roller (パ Application チ Application グ ロ one Le), be more preferably wire roll.
Said in this manual open-work size is meant the diameter of the maximum inscribed circle that is arranged on the open-work on the suction unit.For example, as suction unit, when using wire roll, slit roller or punching roller, said open-work size refer to respectively the slit between the metal wire interval, slit weak point direction length and in be connected to perforated maximum circular diameter.
Open-work gravel size decision 10~5000 μ m.If the open-work size is littler than 10 μ m, not only clean pumping velocity with solvent is low, and exists because the clean of suction removed the metal powder in the groove and the danger that produces pin hole is arranged on micro-porous film with solvent.On the other hand, if the open-work size is bigger than 5000 μ m, the suction vestige takes place easily on micro-porous film.The open-work size is more preferably 20~2000 μ m, preferred especially 50~500 μ m.
The aperture opening ratio of suction roll is not particularly limited, but preferred 1~50%.If this aperture opening ratio less than 1%, suction force worsens, on the other hand, if surpass 50%, because the weakened of roller, so not preferred.Interval along roll axial direction between the open-work is not particularly limited, preferred 0.5~10mm.
Preferred 5~the 500cm of the diameter of suction roll is more preferably 10~200cm.The not enough 5cm of this diameter, the contact area of cleaning forming composition and roller is little, cleans with the suction of solvent insufficient.On the other hand, if diameter surpasses 500cm, equipment too maximizes.
Preferably making swabbing pressure (the hole portion pressure of normal atmosphere and suction unit poor) is 0.5~60kPa, is more preferably 1~40kPa, is preferably 3~20kPa especially.If swabbing pressure is littler than 0.5kPa, clean removing property deterioration with solvent, perhaps be difficult to give tension force to cleaning forming composition, on the other hand,, then be easy to generate the suction vestige if bigger than 60kPa.
Clean the method that forming composition contact with poor solvent as making, have cleaning method that the forming composition volume hangs over the part drip washing poor solvent on the roller, cleaning forming composition to the major general and roll up the part that hangs on the roller and be immersed in method in the poor solvent, these the method etc. of combination.These are removed to handle preferably and carry the method that forming composition is carried out of cleaning on one side continuously on one side by suction roll.From making the viewpoint of efficient,, be more preferably 2~60m/min by the preferred 0.5~80m/min of the transfer rate of suction roll.Usually suction roll with one for well, but be not defined as one.
When cleaning forming composition drip washing poor solvent, the preferred 50~10000ml/m of poor solvent amount 2, be more preferably 100~5000ml/m 2If the not enough 50ml/m of poor solvent amount of drip washing 2, for being removed face, drip washing poor solvent equably, on the other hand, if surpass 10000ml/m 2, then becoming to be difficult to control circulates poor solvent.In the time of will cleaning forming composition and be immersed in the poor solvent, also can in bathing, poor solvent spray poor solvent to cleaning forming composition.Thus, the extraction rate of cleaning with solvent accelerates more, and cleaning of extracting not only be sucked with solvent, and is diffused in the poor solvent, therefore, removes the efficient raising.
Poor solvent is so long as for cleaning the material that lacks intermiscibility with solvent, then be not particularly limited.For example, use methylene dichloride or hydrogen fluorine ether as cleaning when use solvent, as poor solvent, water is suitable, when using pentane as clean when using solvent, and as poor solvent, water, N, dinethylformamide (DMF), ethylene glycol etc. are suitable.
Poor solvent preferably heats, and thus, can promote to clean the gasification with solvent, thereby make rapidization of cleaning with solvent of removing.But from preventing the remollescent viewpoint of thermoplastic resin, the ceiling temperature of poor solvent is the crystallization dispersion temperature of thermoplastic resin or below it, is preferably below crystallization dispersion temperature-5 ℃ or the crystallization dispersion temperature-5 ℃.In the crystallization dispersion temperature or the scope below it of thermoplastic resin, the temperature of poor solvent is more preferably the clean boiling point-10 with solvent that will remove ℃~boiling point+50 ℃, preferred especially cleaning with boiling point~boiling point+50 of solvent ℃, the most preferred cleaning with boiling point+3 of solvent ℃~boiling point+50 ℃.If make the temperature of poor solvent be lower than the boiling point cleaned with solvent-] 0 ℃, it is slack-off that then solvent is removed speed.On the other hand, if the temperature that makes poor solvent clean with boiling point+50 of solvent ℃ for surpassing owing to cause the gasification of cleaning with solvent tempestuously, therefore, the danger that has the outward appearance of film to worsen.
When making water as poor solvent, preferred 30~95 ℃ of its temperature is more preferably 35~90 ℃, preferred especially 40~85 ℃.If the temperature of water is lower than 30 ℃, it is slack-off that solvent is removed speed, if be higher than 95 ℃, the generation of water vapour significantly increases, the operating efficiency variation.
If the volume of cleaning forming composition is hung over the poor solvent of the part drip washing heating on the roller or at least a portion of suction roll is immersed in the poor solvent of heating, suction roll is heated by poor solvent, optionally also can be by heating suction rolls such as storage heaters.The Heating temperature of suction roll is the crystallization dispersion temperature of thermoplastic resin or below it, is preferably below crystallization dispersion temperature-5 ℃ or the crystallization dispersion temperature-5 ℃.In the crystallization dispersion temperature or the scope below it of thermoplastic resin, the Heating temperature of suction roll is more preferably the clean boiling point-10 with solvent that will remove ℃~boiling point+50 ℃, preferred especially cleaning with boiling point~boiling point+50 of solvent ℃, the most preferred cleaning with boiling point+3 of solvent ℃~boiling point+50 ℃.
[3] thermoplastic resin micro-porous film
The rerum natura of the micro-porous film that the method by is as above made, in normal circumstances, hole rate is 25~80%, percent thermal shrinkage all is below 15% or 15% at operating direction (MD) and vertical direction (TD).Particularly, by the film that first method is made, the Gas permeability that is converted into thickness 30 μ m is 10~2000 seconds/100cc, does not have washmarking on the surface.By the film that second method is made, the Gas permeability that is converted into thickness 20 μ m is 10~2000 seconds/100cc, does not aspirate vestige on the surface, also not distortion.
The thickness of thermoplastic resin micro-porous film can suitably be selected corresponding to purposes, for example, when using as battery separator, is preferably 5~200 μ m.The thermoplastic resin micro-porous film that obtains according to manufacture method of the present invention shows excellent perviousness, therefore, is suitable as battery separator, strainer etc.
Embodiment
By following embodiment the present invention is described in further detail, but the present invention is not limited to these examples.
Embodiment 1
In the weight-average molecular weight by 25 quality % is 2.0 * 10 6Ultrahigh molecular weight polyethylene(UHMWPE) (UHMWPE) and the weight-average molecular weight of 75 quality % be 3.5 * 10 5High density polyethylene(HDPE) (HDPE) polyethylene (135 ℃ of fusing points that constitute, Mw/Mn=16, the crystallization dispersion temperature is 90 ℃) in, add in per 100 mass parts compositions 0.375 mass parts as oxidation inhibitor four [methylene radical-3-(3, the 5-di-tert-butyl-hydroxy phenyl) propionic acid ester group] methane, obtain polyethylene composition.Polyethylene composition 25 mass parts that obtain are put into biaxial extruder (internal diameter 58mm, L/D=42, strong mixed milling type), supply with the whiteruss of 75 mass parts from the side direction feeder of this biaxial extruder, under the condition of 200 ℃ and 200rpm, carry out melting mixing, in forcing machine, prepare polyethylene solution.Then, thickness is to extrude this polyethylene solution from the die orifice that is arranged on the forcing machine front end about 40 μ m when making two-way stretch, forms the gel sheet while take out with the cooling roller of temperature adjustment to 50 ℃.For the gel sheet that obtains, use continuous stretcher under 116 ℃, to carry out two-way stretch, so that reach 5 * 5 times, obtain stretched film.The stretched film that obtains is fixed on deckle board [size: 20cm * 20cm, aluminum (down together)] on, and be immersed in Skellysolve A [surface tension: the 15.5mN/m (25 ℃) of temperature adjustment to 23 ℃, boiling point: 36 ℃, solubleness to water: 225ppm (quality criteria) (16 ℃)] ablution groove in, on one side shake with 100rpm and to clean on one side in 30 seconds.According to circumstances Skellysolve A is more renewed liquid on one side, Yi Bian carry out 3 above-mentioned a series of clean operations more repeatedly.Semi-transparent film after cleaning is fixed in the warm water tank that is impregnated into temperature adjustment to 50 ℃ on the deckle board, shakes on one side and carry out the warm water processing and be extracted out and make the film whitening up to Skellysolve A.Remove clean with the needed time of solvent be 5 seconds.To blow with blower attached to the water on the film that obtains and fly,, make microporous polyethylene film again in 122 ℃ of following thermal-settings 60 seconds.
Embodiment 2
Similarly to Example 1, the biaxial stretching film of making is fixed on the deckle board, and be immersed in methylene dichloride [surface tension: the 27.3mN/m (25 ℃) of temperature adjustment to 23 ℃, boiling point: 40.0 ℃, solubleness to water: 20000ppm (quality criteria) (20 ℃)] first ablution groove in, on one side shake with 100rpm and to clean on one side in 30 seconds.According to circumstances methylene dichloride is more renewed liquid on one side, Yi Bian carry out 2 above-mentioned a series of clean operations more repeatedly.Then, film is fixed on the deckle board, and is immersed in the methyl perfluorobutyl ether [composition formula: C of temperature adjustment to 23 ℃ 4F 9OCH 3Trade(brand)name: ノ ベ Star Network HFE-7100, Sumitomo 3M (strain) makes, surface tension: 13.6mN/m (25 ℃), boiling point: 61 ℃, solubleness to water: 12ppm (quality criteria) (25 ℃) does not have flash-point] second ablution groove (flushed channel) in, on one side shake with 100rpm and to wash processing on one side in 20 seconds.The methyl perfluorobutyl ether is replaced by new liquid, repeats above-mentioned a series of flushing operation again.Semi-transparent film after cleaning is fixed in the warm water tank that is impregnated into temperature adjustment to 70 ℃ on the deckle board, shakes on one side and carry out the warm water processing and be extracted out and make the film whitening up to the methyl perfluorobutyl ether.Remove clean with the needed time of solvent be 10 seconds.Then, will blow with blower attached to the water on the film and fly, in 122 ℃ of following heat settings 60 seconds, make microporous polyethylene film again.
Embodiment 3
Except n-decane [surface tension: 23.4mN/m (25 ℃) by temperature adjustment to 60 ℃, boiling point: 173 ℃, solubleness to water: 50ppm (quality criteria) (20 ℃)] carry out cleaning in first ablution groove (cleaning number of times: amount to 3 times), and the temperature that makes warm water is beyond 80 ℃, similarly to Example 2, make microporous polyethylene film.Remove clean with the needed time of solvent be 2 seconds.
Embodiment 4
Similarly to Example 1, make the biaxial stretching film of length 600m and wide 0.4m.The stretched film that obtains by the speed of dividing with 2m/ by cleaning in the continous way decontaminating apparatus.As the continous way decontaminating apparatus, use first ablution groove with 3 methylene dichloride that contain temperature adjustment to 23 ℃ and 2 to contain the decontaminating apparatus of second ablution groove of the methyl perfluorobutyl ether of temperature adjustment to 23 ℃.Residence time in 3 first ablution grooves was respectively 30 seconds, and the residence time in 2 second ablution grooves was respectively 20 seconds.Film after cleaning in the warm water tank by temperature adjustment to 70 ℃, is removed to clean and is used solvent.In warm water tank, the roller of diameter 10cm is set and makes the warm water liquid level be positioned at the position of the following 2cm in axle center, and by making film touch almost half circumference of roller bottom, film contacts with warm water to do one's utmost state of contact with roller.Warm water is kept 70 ℃, and can not cleaned with solvent excessive soil ground and supply with continuously, extracts out simultaneously.The residence time (duration of contact of film and warm water) of film in warm water tank is 4 seconds.Clean remove with solvent after, will blow with blower attached to the water on the film that obtains and fly, again in 122 ℃ of following thermal-settings 60 seconds, make microporous polyethylene film.
Embodiment 5
Similarly to Example 1, make the biaxial stretching film of length 600m and wide 0.4m.The stretched film that obtains by the speed of dividing with 2m/ by cleaning in the continous way decontaminating apparatus.As the continous way decontaminating apparatus, use first ablution groove with 3 methylene dichloride that contain temperature adjustment to 23 ℃ and 2 to contain the perflexane [composition formula: C of temperature adjustment to 23 ℃ 6F 14Trade(brand)name: Off ロ リ Na one ト HC-72, the friendly 3M in position (strain) makes, surface tension: 12.0mN/m (25 ℃), boiling point: 56 ℃, to the solubleness of water: 100ppm (quality criteria) or 100ppm following (25 ℃)] the decontaminating apparatus of second ablution groove (flushed channel).Residence time in 3 first ablution grooves was respectively 30 seconds, and the residence time in 2 second ablution grooves was respectively 20 seconds.The cleaning of containing after cleaning of film removed by the warm water of 75 ℃ of drip washing with solvent.The roller of diameter 10cm is set, and by making film touch the state of almost half circumference on roller top in groove, the warm water that a plurality of nozzles of the axis direction by being configured in roller divide the film drip washing 5L/ that moves from the top of roller.Be 4 seconds the duration of contact of film and warm water.Then, will blow with blower attached to the water on the film and fly,, make microporous polyethylene film again in 122 ℃ of following thermal-settings 60 seconds.
Comparative example 1
Except the n-decane by temperature adjustment to 60 ℃ carries out the processing (cleaning number of times: amounts to 4 times) of the gel forming composition in ablution groove, and to make the temperature of warm water be beyond 80 ℃, similarly to Example 1, and the manufacturing microporous polyethylene film.Remove clean with the needed time of solvent be 600~900 seconds.
Comparative example 2
Except the methylene dichloride by temperature adjustment to 23 ℃ carries out the processing (cleaning number of times: amounts to 4 times) of the gel forming composition in ablution groove, and to make the temperature of warm water be beyond 70 ℃, similarly to Example 1, and the manufacturing microporous polyethylene film.Remove clean with the needed time of solvent be 3 seconds.
Comparative example 3
Except ether [surface tension: 16.4mN/m (25 ℃) by temperature adjustment to 23 ℃, boiling point: 35 ℃, solubleness to water: 65000ppm (quality criteria) (20 ℃)] carry out the processing (clean number of times: amount to 4 times) of the gel forming composition in ablution groove, and the temperature that makes warm water is beyond 70 ℃, similarly to Example 1, make microporous polyethylene film.Remove clean with the needed time of solvent be 2 seconds.
Comparative example 4
Except cleaning by the method that is blown into 70 ℃ warm wind, similarly to Example 2, make microporous polyethylene film with the removing of solvent.Remove clean with the needed time of solvent be 40 seconds.
Comparative example 5
Except cleaning with solvent of flushed channel changed to the methylene dichloride, similarly to Example 4, make microporous polyethylene film.Remove clean with the needed time of solvent be 8 seconds.
The surface picture of the micro-porous film of the embodiment 1 that takes and comparative example 2 is shown among Fig. 1 (embodiment 1) and Fig. 2 (comparative example 2).As depicted in figs. 1 and 2, the surface of the micro-porous film of embodiment 1 does not have washmarking, be homogeneous, and the surface of the micro-porous film of comparative example 1 has produced washmarking.
The rerum natura of the thermoplastic resin micro-porous film that obtains in embodiment 1~5 and the comparative example 1~5 is measured with following method.The results are shown in the table 2.
(1) appearance character: pass through Visual Confirmation.
Zero: do not confirm washmarking;
*: confirmed the generation of washmarking.
(2) film thickness: measure by contact thickness gauge (ミ of Co., Ltd. Star ト ヨ manufacturing).
(3) Gas permeability: measure (being converted into thickness 30 μ m) according to JIS P8117.
(4) hole rate: measure by mass method.
(5) percent thermal shrinkage: measure respectively 3 times with micro-porous film when down exposing 8 hours for 105 ℃ MD and the shrinking percentage of TD, calculate its mean value.
[table 2]
[table 2 is continuous]
Figure C20048002500700301
[table 2 is continuous]
Figure C20048002500700311
Annotate: (1) Mw/Mn=16
(2) ultrahigh molecular weight polyethylene(UHMWPE), Mw=2.0 * 10 6
(3) high density polyethylene(HDPE), Mw=3.5 * 10 5
(4) two-way stretch simultaneously
(5) 30 μ m convert
(6) clean number of times
(7) ablution groove number
(8) methyl perfluorobutyl ether
(9) perflexane
As shown in table 2, appearance character, hole rate, Gas permeability and the heat-resisting shrinkability excellence of the thermoplastic resin micro-porous film of the embodiment 1~5 that makes according to first kind of manufacture method of the present invention.On the other hand, in the comparative example 1, wash processing owing to surpass 100 ℃ clean with boiling point with solvent, therefore, cleaning with removing of solvent needs for a long time, and hole rate and Gas permeability are poor.In comparative example 2,5, because the surface tension that is used in 25 ℃ surpasses 24mN/m, and the solubleness to water under 16 ℃ is cleaned processing and/or flushing processing above cleaning with solvent of 600ppm (quality criteria), and therefore, appearance character, hole rate and Gas permeability are poor.In comparative example 3, surpass cleaning of 600ppm (quality criteria) and clean processing owing to be used under 16 ℃ solubleness to water with solvent, therefore, appearance character, hole rate and Gas permeability are poor.In comparative example 4, use solvent owing to removing with warm wind to clean, therefore, cleaning needs long-time with removing of solvent.
Embodiment 6
In the weight-average molecular weight by 20 quality % is 2.0 * 10 6Ultrahigh molecular weight polyethylene(UHMWPE) (UHMWPE) and the weight-average molecular weight of 80 quality % be 3.5 * 10 5High density polyethylene(HDPE) (HDPE) polyethylene (135 ℃ of fusing points that constitute, Mw/Mn=16.8, the crystallization dispersion temperature is 90 ℃) in, add in per 100 mass parts compositions 0.375 mass parts as oxidation inhibitor four [methylene radical-3-(3, the 5-di-tert-butyl-hydroxy phenyl) propionic acid ester group] methane, obtain polyethylene composition.Polyethylene composition 30 mass parts that obtain are put into biaxial extruder (internal diameter 58mm, L/D=42, strong mixed milling type) in, supply with the whiteruss of 70 mass parts from the side direction feeder of this biaxial extruder, under the condition of 210 ℃ and 200rpm, carry out melting mixing, in forcing machine, prepare polyethylene solution.Then, extrude this polyethylene solution,, form the gel forming composition while take out with the cooling roller of temperature adjustment to 40 ℃ so that thickness is about 45 μ m during two-way stretch from the T type mouth mould that is arranged on the forcing machine front end.For the gel forming composition that obtains, use continuous stretcher to implement two-way stretch, so that be issued to 5 * 5 times at 119 ℃.Then, be that 40cm ground is rolled onto the end cut-out on the paper tube on one side Yi Bian make the width of the biaxial stretching film that obtains, obtain the stretched film that length is 600m.
The stretched film that obtains by the transfer rate of dividing with 16m/ by cleaning in the continous way decontaminating apparatus.As the continous way decontaminating apparatus, use has 3 methylene dichloride [surface tension: 27.3mN/m (25 ℃) that contain temperature adjustment to 26 ℃, boiling point: 40.0 ℃, to the solubleness of water: 20000ppm (quality criteria) (20 ℃)] first ablution groove and 2 methyl perfluorobutyl ether [composition formulas: C that contain temperature adjustment to 26 ℃ 4F 9OCH 3, trade(brand)name: ノ ベ Star Network HFE-7100, Sumitomo 3M (strain) make, surface tension: 13.6mN/m (25 ℃), boiling point: 61 ℃, to the solubleness of water: 12ppm (quality criteria) (25 ℃), do not have flash-point] the decontaminating apparatus of second ablution groove (flushed channel).Regulate each ablution groove liquid level so that the residence time of each first ablution groove and each second ablution groove be respectively 10 seconds.In addition, each ablution groove is provided with new liquid supply line in the bottom, and the height location at liquid level is provided with overflow extraction pipeline simultaneously, on one side with continuous various new liquid, the extract phase amount together on one side supplied with of 4L/min.
The clean forming composition that obtains contact on one side with 85 ℃ warm water on one side remove the clean solvent of using by the suction wire roll.Round metal wire (diameter: 0.8mm) the suction wire roll of Chan Raoing [open-work size (gap between the metal wire): 50 μ m is set in warm water tank, diameter: 10cm], so that the warm water liquid level is positioned at the up position of 4cm of roller foot, make the semicircumference part of cleaning forming composition touch roll bottom.Cleaning forming composition is 0.59 second with the duration of contact of aspirating wire roll, and swabbing pressure is 5kPa.Warm water can not cleaned with solvent excessive soil ground and be supplied with continuously, extracts out simultaneously.To remove in the aluminum frame that clean film with solvent is fixed on 20cm * 20cm, and under 124 ℃, carried out thermal-setting in 120 seconds, thus, made microporous polyethylene film.
Embodiment 7
Except the transfer rate that makes stretched film be the 8m/ branch, supply to that new liquid feed speed in each first ablution groove and each second ablution groove is that 2L/min, swabbing pressure are that the temperature of 20kPa, warm water is 75 ℃, duration of contact of cleaning forming composition and suction wire roll is 1.18 seconds, similarly to Example 6, make microporous polyethylene film.
Embodiment 8
Except making flushing handle with cleaning with solvent is that the metal wire gap of methylene dichloride, suction wire roll is the 100 μ m, similarly to Example 6, and the manufacturing microporous polyethylene film.
Embodiment 9
Is Skellysolve A [surface tension: 15.5mN/m (25 ℃) except making the clean of first ablution groove and second ablution groove with solvent, boiling point: 36 ℃, solubleness to water: 225ppm (quality criteria) (16 ℃)], the transfer rate of stretched film is the 12m/ branch, the new liquid feed speed that supplies in each first ablution groove and each second ablution groove is 3L/min, the metal wire gap of suction wire roll is 200 μ m, swabbing pressure is 10kPa, the temperature of warm water is 80 ℃, cleaning forming composition is beyond 0.79 second with the duration of contact of aspirating wire roll, similarly to Example 6, make microporous polyethylene film.
Embodiment 10
Except making poor solvent is the N of temperature adjustment to 80 ℃, and dinethylformamide replaces beyond the warm water, similarly to Example 9, makes microporous polyethylene film.
Embodiment 11
Except the solvent that makes first ablution groove is that n-decane [surface tension: 23.4mN/m (25 ℃), boiling point: 173 ℃, to the solubleness of water: 50ppm (quality criteria) (20 ℃)], the clean of flushed channel of temperature adjustment to 55 ℃ is perflexane [composition formula: C with solvent 6F 14Trade(brand)name: Off ロ リ Na one ト HC-72, Sumitomo 3M (strain) makes, surface tension: 12.0mN/m (25 ℃), boiling point: 56 ℃, solubleness to water: 100ppm (quality criteria) or 100ppm following (25 ℃)], the metal wire gap of suction wire roll is that 200 μ m, swabbing pressure are that the temperature of 20kPa, warm water is beyond 70 ℃, similarly to Example 6, makes microporous polyethylene film.
Comparative example 6
Except being the duration of contact that the transfer rate that makes stretched film is the 8m/ branch, to supply to new liquid feed speed in each first ablution groove and each second ablution groove be 2L/min, clean forming composition and suction wire roll 1.18 seconds, similarly to Example 6, make microporous polyethylene film.
Comparative example 7
Except making swabbing pressure is the 20kPa, similarly to Example 6, makes microporous polyethylene film.
Comparative example 8
Except being the duration of contact that the transfer rate that makes stretched film is the 8m/ branch, to supply to new liquid feed speed in each first ablution groove and each second ablution groove be 2L/min, clean forming composition and suction wire roll 1.18 seconds, similarly to Example 8, make microporous polyethylene film.
The rerum natura of the thermoplastic resin micro-porous film that obtains in embodiment 6~11 and the comparative example 6~8 is measured with following method.The results are shown in the table 3.
(1) appearance character: pass through Visual Confirmation.
Zero: do not confirm the suction trace;
*: confirmed the generation of suction trace.
(2) film thickness, (3) hole rate, (4) Gas permeability and (5) percent thermal shrinkage are according to measuring (still, Gas permeability is that thickness 20 μ m convert) with the same method of embodiment 1~5.
[table 3]
[table 3 is continuous]
Figure C20048002500700361
[table 3 is continuous]
Figure C20048002500700371
Annotate: (1) Mw/Mn=16.8
(2) ultrahigh molecular weight polyethylene(UHMWPE), Mw=2.0 * 10 6
(3) high density polyethylene(HDPE), Mw=3.5 * 10 5
(4) 20 μ m convert
As shown in table 3, the thermoplastic resin micro-porous film appearance character of the embodiment 6~11 that makes according to method of the present invention is excellent especially, and hole rate, Gas permeability and heat-resisting shrinkability are also excellent.On the other hand, the micro-porous film of comparative example 6~8 owing to clean the scope that exceed above-mentioned general formula (1) expression the duration of contact of forming composition and suction roll, therefore produces the suction vestige of striated on the surface of film, and outward appearance worsens.In addition, comparative example 6 is removed the identical embodiment of condition 7 with film forming with solvent and is compared, and hole rate and Gas permeability are poor, and comparative example 7 is removed the identical embodiment of condition 6 with film forming with solvent and compared, and hole rate and Gas permeability are also poor.

Claims (3)

1. method of making thermoplastic resin micro-porous film, this method is by being extruded by the mouth mould thermoplastic resin and film forming to be carried out the solution that melting mixing obtains with solvent, and by clean with solvent remove above-mentioned film forming remaining in the gel forming composition that cooling obtains with solvent after, remove the above-mentioned method of making thermoplastic resin micro-porous film with solvent of cleaning, it is characterized in that, as the above-mentioned clean solvent of using, use (a) surface tension under 25 ℃ temperature as 24mN/m or below the 24mN/m, (b) boiling point under atmospheric pressure is below 100 ℃ or 100 ℃, and (c) solubleness to water is counted 600ppm or the solvent below the 600ppm with quality criteria under 16 ℃ temperature, simultaneously, do not use suction unit, use warm water from removing the remaining described clean solvent of using the above-mentioned forming composition of cleaning with solvent after clean, the ceiling temperature of described warm water is the crystallization dispersion temperature of thermoplastic resin, and lower limit temperature is for cleaning with the boiling point-5 of solvent ℃.
2. the manufacture method of a thermoplastic resin micro-porous film, this method is by being extruded by the mouth mould thermoplastic resin and film forming to be carried out the solution that melting mixing obtains with solvent, and by clean with solvent remove above-mentioned film forming remaining in the gel forming composition that cooling obtains with solvent after, so that the forming composition after above-mentioned clean with for above-mentioned clean poor solvent state of contact with solvent, forming composition after making above-mentioned poor solvent by above-mentioned clean by suction unit is removed the above-mentioned clean method of making thermoplastic resin micro-porous film with solvent, it is characterized in that, make the forming composition after above-mentioned clean and t duration of contact of above-mentioned suction unit satisfy the scope of following general formula (1):
t≤(100-T) 3/(1100×P 0.5×logL)...(1)
In the formula, duration of contact, the unit of t was second; T is the temperature of above-mentioned poor solvent, and unit is ℃; P is a swabbing pressure, and unit is kPa; L is the size of the open-work of the above-mentioned suction unit of the above-mentioned clean usefulness solvent of suction, and this is of a size of the diameter of the maximum inscribed circle of above-mentioned open-work, and unit is μ m.
3. the manufacture method of the described thermoplastic resin micro-porous film of claim 2, wherein said poor solvent is a warm water, and the ceiling temperature of described warm water is the crystallization dispersion temperature of thermoplastic resin, and lower limit temperature is for cleaning with the boiling point-5 of solvent ℃.
CNB2004800250073A 2003-09-05 2004-08-31 Production method of thermoplastic resin microporous membrane Expired - Fee Related CN100453585C (en)

Applications Claiming Priority (3)

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JP2003314039A JP5083927B2 (en) 2003-09-05 2003-09-05 Method for producing polyolefin microporous membrane
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JP4634192B2 (en) * 2005-03-10 2011-02-16 日東電工株式会社 Method for producing porous membrane
JP5832907B2 (en) * 2012-01-10 2015-12-16 鉄郎 野方 Method for producing polyolefin microporous membrane
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JP2001081229A (en) * 1999-09-16 2001-03-27 Toyo Cloth Co Ltd Biodegradable porous membrane and its preparation
JP2002256099A (en) * 2001-03-02 2002-09-11 Tonen Chem Corp Method for producing thermoplastic resin microporous membrane
JP2003082151A (en) * 2001-09-06 2003-03-19 Tonen Chem Corp Process for producing thermoplastic resin molded product and fine porous membrane composed of its thermoplastic resin molded product
CN1437629A (en) * 2000-06-30 2003-08-20 东燃化学株式会社 Method for producing thermoplastic resin micro-porous film

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JP2001081229A (en) * 1999-09-16 2001-03-27 Toyo Cloth Co Ltd Biodegradable porous membrane and its preparation
CN1437629A (en) * 2000-06-30 2003-08-20 东燃化学株式会社 Method for producing thermoplastic resin micro-porous film
JP2002256099A (en) * 2001-03-02 2002-09-11 Tonen Chem Corp Method for producing thermoplastic resin microporous membrane
JP2003082151A (en) * 2001-09-06 2003-03-19 Tonen Chem Corp Process for producing thermoplastic resin molded product and fine porous membrane composed of its thermoplastic resin molded product

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