JPS60217145A - Composite film - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a composite membrane having polytetrafluoroethylene as a support.

(Conventional technology) As we enter an era of high crude oil prices and are increasingly pursuing energy and resource conservation,
In addition to saving energy by improving the separation technology established from rice, new separation technologies such as membrane separation are being considered. For example, oxygen/
Nitrogen separation II (oxygen enrichment membrane) is also being put into practical use.
Furthermore, it is also being considered to apply these films to diaphragms in batteries that use oxygen as an active material, such as air-zinc batteries.

Silicone rubber is an example of a material with a high gas permeability coefficient, but the drawback of silicone rubber is that its mechanical strength is weak, and it cannot be made into a thin film as it is, so it is necessary to improve the strength by modifying the silicone with polycarbonate etc. It is applied onto a porous body and cured by heat. However, with this method, pinballs may occur in the film due to heat curing.
It has the disadvantage of low productivity. In addition, the heat curing method has problems in separations that require corrosion resistance and solvent resistance.

(Object of the Invention) An object of the present invention is to provide a composite membrane that is excellent in selectively separating gases.

Another object of the present invention is to provide a composite membrane with excellent heat resistance and mechanical strength.

A further object of the present invention is to provide a composite membrane that has excellent corrosion resistance and solvent resistance and can be manufactured with high productivity.

(Structure of the Invention) The present invention comprises laminating a thin film of a resin whose main component is a repeating unit of fluorine-containing (meth)acrylate represented by the following general formula (a) or (b) on the surface of porous polytetrafluoroethylene. It relates to a composite membrane consisting of.

Two-diaphragm Ah Yu1 +c Hw -C+ Y + COO(C)k(CL)m+ (CFt)r++Z2 [x+ represents CHa, F, CI, Br or H, Y and Y2 are carbon atoms of 1 to 4 Indicates the same or different lower alkyl groups. Z represents F, CF(Ch)2 or H.

k is 0 or 1. III is an integer from 1 to 3 t nl is 0 or an integer from 1 to 12. (However, if Z is an H group, nl
is an integer from 1 to 12) 4A01 2 "+C1, -C+-CF, CF.

1 1 1 COO (CI+2)v, CF (OCF, CF)n, O
cF, cF2cF3[X2 is CH3=F-CI-
Br or H indicates. -2 is an integer of 1 to 3, and n2 is 0 or an integer of 1 to 6. ] In the present invention, porous polytetrafluoroethylene (hereinafter referred to as PTF) is used as a support for the composite membrane.
(referred to as E). Such PTFE has excellent heat resistance and is extremely suitable as a support. The porous PTFE that serves as the support is, for example, an unfired PTFE body with a density of about 0.5 to 1.8 (used for sealing threaded joints as specified in JIS K8885, and usually raw tape (un
Also called sintered tape)
, width, and thickness are arbitrary, or those that are primarily stretched leaving room for further stretching, and furthermore, such unfired bodies are heat-treated at 327 to 347°C and have a density of 1.8 to 1.8.
Examples include a PTFE molded body of about 2.3 mm (hereinafter referred to as "PTFE semi-fired body") and its subsequent stretched body.

The PTFE used in the present invention is a homopolymer of tetrafluoroethylene or a comonomer such as hexafluoropropylene, chlorotrifluoroethylene, perfluoroalkyl vinyl ether, or vinylidene fluoride in an amount of 1% by weight or less to tetrafluoroethylene. Copolymerized copolymers can be mentioned.

The average pore diameter of the pores of the porous P'TFE is preferably in the range of 0.01 to 1 μm. Note that the average pore diameter refers to the diameter when the pore area is considered to be a perfect circle. In addition, among the above-mentioned PTFE supports, the unfired body has self-adhesiveness and can be backed with a weak force without the need for an adhesive. If you don't use adhesive on the body, gas will leak.

In the present invention, fluorine-containing (meth) represented by the following general formula (a) or (b) is formed on the surface of porous PTFE as a support.
Thin films of resin mainly composed of repeating units of acrylate are laminated.

Two-pronged 0yu X.

+CH2-C) Y.

II Coo(C)k(CHI)Ill+(CFz)n+Z'
Y2 [X+ represents CH3-F-CI-Br or H,
Y and Y2 represent the same or different lower alkyl groups having 1 to 4 carbon atoms. Z represents F*CF(CFs)2 or H.

k is 0 or 1. 1Ill is an integer from 1 to 3 nl is 0
or an integer from 1 to 12. (However, if Z is an H group, n is an integer from 1 to 12).C00(CH2)11iCF(OCF2CF)n20c
F2cF2cFa[X2 is CHs*F-CI-
Indicates Br or H. -2 is an integer of 1 to 3, and n2 is 0 or an integer of 1 to 6. 1 The repeating unit of general formula (a) is derived from the following monomers, for example.

(1) C112=C(C13)COOC112CF2
C.F.

CI (2=C<CH,) COOCH, CF, CF, CF
, .

CHz=C(CHs)COOCHz(CFt)++CF
s-CHi=C(CHs)COOCHi(CF2)sC
F-C112=C(CH3)COOCIIICIICF
2CF3゜C112=C(C113)COOC12CF
2CF2CF, CF,.

CH2=C(CHj)COOCHtCHi(Ch)yc
Fs*CH2=C(CI+)C00CII2CH2(C
F2) scFie etc.C11z=C(CHI)CO
A compound represented by O(CIlz)II(CFz)nF.

(2) C112=C(C11,)COOCH2(CF
2) 2CF (CF3h.

CHz=C(CHs)COOCHt(CF2)aCF(
CFs)2-CH2=C(CH3)CH2CF2(CF
t)4CF(CF3)2.

CH2=C(C113)C00CH2CH2(CF2)
2CF(CF,)29C112=C(CHa)COOC
C such as HtCHi2(CFt)<CF(CFs)z-
l2=C(Cfl*)COO(CF12)m(CF2)
A compound represented by n(:F(CFa)a.

(3') CH2=C(C1,)COOCHt(CF2
)2H.

C11□=C(Clls)COOCHt2(CFt)J
*CHa=C(C113)COOCIl, *(CF2)
all.

C112=C (C1st 5) COOCHzCHi (Ch)
cH,=c(C1l,')COO(C
A compound represented by HI)m(CFt)nH.

(4) Cl2=CHCOOCHzCF, CHt=
CHCOOCH, CFzCFs*CHx=CRCOOC
Ih(CFt)2CFs-CH2=CHC00CI+2
(CF2)3CF3゜CHz=CHCOOCII2CH
2CFzCFs-Cl2=CHCOOCHzCF2(C
F2), CF3. CH2CHCOO(CHz)m such as
A compound represented by (CF2)nF.

(5) Cl2=CHCOOCHzCF(CF3)2-
CHz=CHCOOCH2CF2CFzCF(CFa)
2-CH2=CFICOOCR2(CFffi)4CF
(CFri2tC112=CICOOCII2CH2(C
h) tCF(CF+)z- etc. in CHz = C) ICOO
A compound represented by (CL)-(CFz)nCF(CFs)2.

(6) CHI=CHC00CHiChCF 211
CH2=CHCOOCI12(CFt), 1l-CHz
=CHCOOCL(CF2)sH-CHz=CIICO
CH*=j' such as OCHzCII2(CFz)nH-
A compound represented by HCOO(CHI)+++(CFz)nll.

(7) CH2=CFCOOC112CF2CF2CF3
tCI(2=CFCOOC1!2(CF2)ICF3f
CH2=CFCOOC112 (CF2), CF3°C1
2=CFCOOCH2(CF2)8CF3. C1 such as
A compound represented by 12=CFCOO(C1lz)ffl(CF2)nF.

(8) C112=CFCOOCH2CF(CFd21C
112=CFC00C1(2(CF2)2CF(CF,
)2°CH2=CBC00CH2(CF2)? CF(C
F3) 21 etc.C11□”CFCOO(CIlz)
A compound represented by m(CF2)nCF(CF3)2.

(9) C112=CCICOOCH2CF2CF2C
F.

CH2=CrlrCOOCH2CF2CF2CFa.

Compounds shown by etc.

(10) C11□=CFCOOCR2(CF2)+(
-C112=CFCOOCH2(CF2)4HIC1l
2 = CFCOOCII 2 (CF 2 )6
CH2=CFC00(CI(2)lIl(C
F2) nll.

C112=CBrCOO(CL2)+(CF2)nHt
C112=CCICOO(CH2)+e(CF2)nl
A compound represented by l.

(11) Also, Cl2=CHCOOC(CI, )2(CF
2) 21(.

CH2=CHC00C(CH3)2 (CF2), 1
l-CH2=CBC00C(CF13)(CJs)(C
F2)211+CI□=CHC00C(CH3)(C,
Also included are fluorine-containing (meth)acrylates substituted with methylene groups, such as 1(9)(CF2)211.

The repeating unit of general formula (b) is derived from, for example, the following monomers.

(1) CH2=C(C1(,)C00CH2CF(C
F,)OCF2CF2CF,.

CH2=C(C1(,)C00CFl'2CF(CF,
)OCF2CF(CF,)OCF2CF2CF,.

C) 12=c(C11s)C00CH2CF(CF-)
[0CF2CF(CFs)]20CF2CF2CF3゜C1(2=C(C)1.)C00CH2CF(CF,)
[0CF2CF(CFff)130CF2CF2CFl
*el+2=C(CI+, )COOCH2C112CF
(CF, )OCF2CF(CF, )OcF2cF2
CI+2 such as cF3t = C(Cl3)Coo(CF12)mCF
(CFs) [0CF2CF(CF*)]n0CF2
A compound represented by CF2CFs.

(2) C112=CflC00CF12CF(CF3
)OCF2CF2CF3-CH2=CHC00CI(2
CF(CF, )OCF2CF(CF3)OCF2C
F2CF,.

e112=CIlCOOC112CF(CL)IOC
F2CF (CF, )120CF2CF2CF,.

Cl2=CIlCOOC112C112CF (CF,
)OCF2CF(CF, )OCF2CF2CF, , etc.C112=CIlCOO(CI+2)mcF(CFs
)[0CF2eF(CF3)]n0CF2CF2C
Compound represented by F3.

(3) C12=CFCOOCH2CF(CF3)OC
F2CF2CF, l.

C11□=CFCOOCR2CF(CF, )OCF2
CF (CP, ) OCF, CF.

C.F.

C112=CFC00CH2CF(CF3)[0CF2
CF (CF3) 120CF2CF2CF! .

C12=CFCOOCH2CF(CF,)[0CF2C
F(CF3)]30CF2CF2CFs-cn2=cpcoOco2cn2cp(cp,)OCF
CL=CFCOO(CI2)IIICF(CF3)[0
CF2CF(CF3)]n0CF2CF2CF3 CH2=CBrC00(CH*)ncF(CFa)[0
CF2CF(CFi)]nOCF2CF2CF3 CH2=CBrC00(C12)mcF(CF*)[0
Examples include compounds represented by CF2CF(CFa)]n0CF and CFzCFs.

The membrane material of the present invention is composed of a resin containing a fluorine-containing (meth)acrylate repeating unit represented by the general formula (a) or (b) as a main component, preferably 50% by weight or more. In the present invention, a membrane material containing a repeating unit represented by the following general formula (e) in addition to general formulas (a) and (b) can be used.

2Ib(jy X3 -(-CH2-(J- CC00(CH2), A
2O, and l113 is an integer from 1 to 20. However, A is C
00) In the case of I, the import is 0. 1 The repeating unit of general formula (e) is derived from the following monomers, for example.

(1) C1(2=CXCOOCH1, CI+2=CX
COOCH2CH1゜C112=CXCOO(CI'+
2) Compounds represented by C1(2=CXCOO(CH2)IIIH) such as 3CH3-CHz=CXCOOC+tH3s.

(However, X is the same as X above, and the same applies hereinafter) (2) CH2
=CXC00CH, CH2011゜CH2=CXC00
(CI+2)3011C112=CXCOO(CH2)
40H Tono CH2”CXC00(CH2)IIIol
A compound represented by f.

(3) CH2=CXC00CH2CH-CH2゜\1 CH2=CXC00(CH2), Cl1-CI2, etc.\1 (4) CH2=CXC00CHzCH20COeNz
teH2=cXcOQ(CL)30CO-@-N*tC
H2=CXCOO(CH2)40CO-@-N, CH2= CXCOO(CH2)mOco eNa
t' % Rel compound.

(5) A compound represented by CL=CXCOOI.

When a functional group is contained in the structure of a gas selective permeation membrane material, it is possible to crosslink it using a method suitable for the functional group, and this can increase the strength of the membrane material, but if too much is contained. This is not preferable because the amount of gas permeation decreases.

The membrane material of the present invention can be obtained by polymerizing the above-mentioned fluorine-containing (meth)acrylate monomer and, if necessary, a monomer represented by general formula (c) by a known method. For example, it is preferable to carry out the polymerization in the presence of a radical initiator, usually at a temperature in the range of 0 to 150°C, and any of solution, suspension, emulsification, and bulk polymerization methods can be employed. Known compounds can also be used as radical initiators.

Any method may be used to laminate a thin film of the membrane material resin on the surface of a PTFE support, for example, the resin may be coated as it is or dissolved in a solvent and coated on the support using a spin coater method or a dipping method. Examples include a method of coating the resin by a method such as a method of coating the resin, a method of creating a film of the resin, placing the film on a support and adhering it tightly by a method such as thermocompression bonding. Lamination can also be carried out by a water spreading method.

Examples of the above solvent include 1,1.2-trichlorotrifluoroethane, 1,1,2,3,1.4-hexachlorohexafluorobutane, hexafluorometa-xylene,
Examples include acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, and the like.

The thickness of the support is generally preferred to be about 30 to 150 microns.

The thickness of the membrane material resin layer is usually 10μ or less, preferably about 0.1 to 10μ, more preferably about 0.2 to 10μ.
It is better to use the 5μ theory.

The composite membrane of the present invention may have various arbitrary shapes, such as films, sheets, pipes, tubes, and the like.

The composite membrane of the present invention is useful, for example, as a gas separation membrane,
It can be used for separation of oxygen/nitrogen, hydrogen/Co, tritium/hydrogen, recovery of lower hydrocarbons, helium, xenon, krypton, etc., separation of S02, CO2, etc.

(Effects of the present invention) The composite membrane of the present invention is excellent in selective separation of gases, and is also excellent in heat resistance, corrosion resistance, solvent resistance, and mechanical strength, and can be manufactured with high productivity.

(Example) EXAMPLES Examples and comparative examples of the present invention will be described below.

Examples 1 to 15 A membrane material resin consisting of general formula (a) or general formulas (a) and general formulas (c) in the proportions shown in Table 1 was dissolved in methyl ethyl ketone, and an unfired support material was coated using a spin coater method. t
A composite membrane was obtained by coating the surface of a porous PTFE membrane. The gas permeation rate of 02 and N2 in the obtained composite membrane E unit: ee (S
TP)/am2・see-cmHg, resin film thickness is 1
Table 1 shows the values for μ plane] and the Ox/Nz separation coefficient. In the Z term of general formula (a) in the table, (p) is CF (
CF, ) 2 in the term A of general formula (c).

shows. In principle, measurement of gas permeation amount is ^5TND 1
This was carried out by the method of No. 4314.

Examples 16-29 Membrane material resin consisting of general formula (b) or general formula (b) and general formula (c) listed in Table 2 was used as hexafluorophtaxylene (for Examples 16, 19 and 24, methyl ethyl ketone) Unfired P
A composite membrane was obtained by coating the surface of the TFE porous membrane. The results are shown in Table 2. (Y) in the table is the same as in Table 1.

# 1 Table (1) # 1 Table (2) 2nd Table (1) 2nd Table (2) (Continued from page 1 O Inventor 1) Reprint @ Inventor Naoaki Izumitani @ Inventor 1 ) Yasushi Settsu City Oaza-Tsuya 7001-1 Daikin Industries, Ltd. Yodogawa Plant Sakai Kogyo Sakai Plant

Claims (1)

[Scope of Claims] (1) Fluorine-containing (meth) represented by the following general formula (,) or (b) on the surface of porous polytetrafluoroethylene
A composite film made by laminating thin films of resin whose main component is repeating units of acrylate. Second ship A0y 1 -(-CI+2-C+-Y1 1 COO(C)k(CIL)m+ (CF2)n+22 [X represents CH,, F, CI, Br or H, Yl and Y2 have 1 carbon number ~4 same or different lower alkyl groups. Z represents F, CF (CF, ), or H. k is 0 or 1.ll1l is an integer of 1 to 3, n is 0 or r'Q 1 is an integer from 1 to 12) J 2412 layer upper upper 2 ■ (CI(2-C) CF, CF. 1 1 1 C00 (CH2) 1112CF (OCF2CF) n20
cF2cF2cFi[X2 is CH3, F-CI-B
Indicates r or H. ll12 is an integer from 1 to 3, n2 is O
or an integer from 1 to 6. 1(2) The density of the porous polytetrafluoroethylene is in the range of 0.5 to 1.8,
The composite membrane according to claim #1, wherein the pores have an average pore diameter of 0.01 to 1 μ-. (3) Fluorine-containing (
The proportion of repeating units of meta)acrylate is 50%
A composite membrane according to claim 1, which uses the above resin.