JP2001172343A - Preparation method of fluorine-containing block copolymer and fluorine-containing block polymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a fluorine-containing block copolymer having excellent solvent resistance and cold resistance. SOLUTION: A preparation method of the fluorine-containing block copolymer comprises copolymerizing (a) vinylidene fluoride, (b) another monomer copolymerizable with the vinylidene fluoride and (c) a perfluoropolyether having allyl groups at both ends, represented by formula [1]: CH2=CHCH2NHCOCF (CF3)O[CF2CF(CF3O]mRf[OCF(CF3)CF2]nOCF(CF3)CONHCH2CH=CH2, [wherein Rf is a 2-6C perfluoroalkylene group; (m) and (n) are each a positive integer and the sum of (m) and (n) is >=20], and the fluorine-containing block copolymer obtained by this method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a fluorinated block copolymer and a fluorinated block copolymer, and more particularly, to a method for producing a fluorinated block copolymer having excellent solvent resistance and cold resistance. The present invention relates to a method and a fluorinated block copolymer having the above properties obtained by the method.

[0002]

TECHNICAL BACKGROUND OF THE INVENTION Fluorine-based elastomers and fluorine-containing (co) polymers are
Generally, it has good resistance to heat, solvents, and corrosive chemicals, and is required to have heat resistance, chemical resistance, etc., such as films, gaskets, O-rings, coated cloths, electric wire insulation coating materials, and hoses. Used as a protective coating material.

[0003] Such a fluorine-containing (co) polymer has room for further improvement in solvent resistance, cold resistance, etc., depending on the use and the like.
Various technologies relating to polymers have been proposed. For example, Japanese Patent Publication No. 54-1585 discloses a fluorine-containing polymer composition comprising a fluorine-containing polymer containing 3 mol% or less of a bromine-containing olefin unit as a copolymer component unit and an organic peroxide. I have. The peroxide crosslinked product obtained from this composition, although showing some degree of cold resistance, has a problem of poor solvent resistance.

Further, Japanese Patent Publication No. 58-4728 discloses that
A fluorine-containing multi-segmented polymer obtained by copolymerization using an iodine compound as a chain transfer agent is described.However, since the iodine compound used as a chain transfer agent is a low molecular compound, the cold resistance is improved. Can not expect at all. For this reason, the polymer described in the publication cannot be used as a vulcanization molding material such as a fuel oil-based sealing material which requires solvent resistance and cold resistance.

[0005]

An object of the present invention is to solve the problems associated with the prior art as described above, and to provide a method for producing a fluorine-containing copolymer excellent in solvent resistance and cold resistance. It is an object. Another object of the present invention is to provide a fluorinated copolymer having excellent solvent resistance and cold resistance obtained by the above method.

[0006]

SUMMARY OF THE INVENTION The process for producing a fluorine-containing block copolymer according to the present invention comprises the steps of (a) vinylidene fluoride, (b) the above vinylidene fluoride (a) and the following perfluoropolyether (c). and other monomers capable, (c) formula _{[I]: CH 2 = CHCH} 2 NHCOCF (CF 3) O [CF 2 CF (CF 3) O] m Rf [OCF (CF 3) CF 2] n _{OCF (CF 3) CONHCH 2 CH} = CH 2 ... [I] (In the formula [I], Rf is a perfluoroalkylene group having 2 to 6 carbon atoms, m and n are positive integers, and the sum of both is 20 or more. ) And a perfluoropolyether having allyl groups at both ends represented by the formula (1).

In the present invention, the above vinylidene fluoride is used.
(a): 40 to 85 mol%, other monomer other than vinylidene fluoride (b): 10 to 35 mol%, and the above perfluoropolyether (c) [to hexafluoropropylene oxide (HFPO) Conversion and calculation]: 1 to 25 mol% (however, (a) + (b) + (c) = 100 mol%) is preferably copolymerized.

In the present invention, the "other monomer" (b) other than the above vinylidene fluoride includes (a) another fluorine-containing monomer other than the above vinylidene fluoride, and (b) an unsaturated carbon It is desirable that at least one monomer selected from hydrogen monomers is used. In the present invention, the fluorine-containing monomer (a) is an unsaturated hydrocarbon having 2 to 8 carbon atoms in which at least a part of a hydrogen atom is substituted by fluorine; an alkyl group (at least a part of a hydrogen atom is substituted by fluorine) And the remainder may be substituted with another halogen atom.) A perfluoroalkylvinyl ether having 1 to 5 carbon atoms; an alkyl group and an alkoxy group (provided that one part of the hydrogen atom of the alkoxy group and the alkyl group is Perfluoro (alkoxy) having 1 to 20 carbon atoms may be substituted by a halogen atom other than a fluorine atom, or an oxygen atom may be interposed between adjacent carbon atoms. Alkyl vinyl ether); one or more selected from the group consisting of:

In the present invention, the unsaturated hydrocarbon monomer (b) is an olefin having 2 to 6 carbon atoms,
15 unsaturated vinyl esters, wherein the alkyl group has 1 carbon atom
1 selected from alkyl vinyl ethers of
It is desirable that the number of species is two or more. The fluorinated block copolymer according to the present invention comprises (a-1) a component unit derived from vinylidene fluoride, and (b-1) the above vinylidene fluoride (a) and perfluoropolyether (c). A component unit derived from another polymerizable monomer, and (c-1) a compound represented by the following formula (I-
a] a perfluoropolyether component unit represented by the formula: [Ia]:

[0010]

Embedded image

(In the formula [Ia], Rf is a perfluoroalkylene group having 2 to 6 carbon atoms, m and n are positive integers, and the sum of both is 20 or more.) In the fluorine-containing block copolymer, the vinylidene fluoride component unit (a-1) was copolymerized with the above vinylidene fluoride (a) and the following perfluoropolyether (c) in an amount of 40 to 85 mol%. The component units (b-1) derived from other possible monomers are present in an amount of 10 to 35 mol%, and the perfluoropolyether component units (c
-1) [calculated in terms of hexafluoropropylene oxide (HFPO) units] in an amount of 1 to 25 mol% ((a-1) + (b-
1) + (c-1) = 100 mol%).

In the present invention, the monomer component unit (b-1) other than the above vinylidene fluoride is (A) a component unit derived from a fluorine-containing monomer other than the above vinylidene fluoride, And (b) at least one monomer component unit selected from component units derived from unsaturated hydrocarbon monomers.

In the present invention, the fluorine-containing monomer component unit (a) is preferably an unsaturated hydrocarbon having 2 to 8 carbon atoms in which at least a part of a hydrogen atom is substituted by fluorine; an alkyl group (hydrogen atom May be substituted with fluorine, and the remainder may be substituted with another halogen atom.) A perfluoroalkyl vinyl ether having 1 to 5 carbon atoms; an alkyl group and an alkoxy group (provided that an alkoxy group, an alkyl group May be substituted with a halogen atom other than a fluorine atom, or an oxygen atom may be interposed between adjacent carbon atoms to form an ether bond.) ~ 20 perfluoro (alkoxyalkyl vinyl ethers); component units derived from one or more selected from the group.

In the present invention, the unsaturated hydrocarbon monomer component unit (b) may be an olefin having 2 to 6 carbon atoms, an unsaturated vinyl ester having 4 to 15 carbon atoms, or a carbon atom of an alkyl group. Is preferably derived from one or more monomers selected from among 1 to 5 alkyl vinyl ethers. According to the present invention, a fluorinated copolymer excellent in solvent resistance and cold resistance is provided.

[0015]

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the method for producing the fluorinated block copolymer according to the present invention and the fluorinated block copolymer obtained by the production method will be specifically described. <Production of Fluorine-Containing Block Copolymer> In the present invention, when producing a fluorinated block copolymer, (a) vinylidene fluoride (VdF) and (b) the above vinylidene fluoride (a)
And and the following perfluoropolyether (c) copolymerizable with the monomers, (c) formula _{[I]: CH 2 = CHCH} 2 NHCOCF (CF 3) O [CF 2 CF (CF 3) O] _m Rf [OCF (CF ₃ ) CF ₂ ] _n OCF (CF ₃ ) CONHCH ₂ CH = CH ₂ ... [I] (In the formula [I], Rf is a perfluoroalkylene group having 2 to 6 carbon atoms, m and n are positive integers, and the sum of both is 20 or more. ) Is copolymerized with a perfluoropolyether having allyl groups at both ends.

Hereinafter, the "other monomer" (b), the perfluoropolyether (c), and the like used in producing the above-mentioned fluorinated block copolymer will be sequentially described. <Other monomer (b)> Examples of other monomers (b) copolymerizable with the above vinylidene fluoride (a) and the following perfluoropolyether (c) include (a) the above vinylidene fluoride And other fluorine-containing monomers copolymerizable with (a) and (a) and (a).

Of these monomers, vinylidene fluoride
(A), copolymerizable with unsaturated hydrocarbon monomer (b), etc.
The following are examples of other fluorine-containing monomers (a).
I can do it. That is, (i): a chain or ring structure (aromatic ring, alicyclic ring)
Water in unsaturated hydrocarbons having 2 to 8 carbon atoms which may be present
Those in which some or all of the elementary atoms have been replaced by fluorine atoms,
For example, tetrafluoroethylene (TFE), hexafu
Luoropropene (HFP), pentafluoropropene,
Hexafluoroisobutene, vinyl fluoride, trifluoro
Roethylene, perfluorocyclobutene, perfluoro
(Methylcyclopropene), 1,2,2-trifluorostyrene
(Ii): having a chain or ring structure (aromatic ring, alicyclic ring)
Of hydrogen atoms in unsaturated hydrocarbons having 2 to 8 carbon atoms
Part is replaced with a fluorine atom, and all or all of the remaining hydrogen atoms
Is partially substituted with another halogen atom, such as
For example, chlorotrifluoroethylene, 1-bromo-2,2
-Difluoroethylene (BDFE), bromotrifluoro
Roethylene (BTFE), 1-iodo-2,2-diflu
Oroethylene (IDFE), iodotrifluoroethylene
(ITFE), trichlorofluoroethylene (CTF)
(Iii): an alkyl perf having 1 to 5 carbon atoms in the alkyl group.
Fluorovinyl ether such as methyl perfluorobi
Nyl ether, ethyl perfluorovinyl ether, n
-Or iso-propyl perfluorovinyl ether,
n-, iso- or tert-butyl perfluorovinyl ether
Ether, n- or iso-amyl perfluorovinyl ether
(Iv): an alkyl group (provided that a part of a hydrogen atom of the alkyl group is included)
May be substituted with a halogen atom other than a fluorine atom.
No. ) Having 1 to 5 carbon atoms
Ether) such as perfluoro (methyl vinyl ether)
-Tel) (FMVE), perfluoro (ethyl vinyl ether)
Ter), perfluoro (n- or iso-propylbi)
Nyl ether), perfluoro (n-, iso- or
3-butyl vinyl ether), perfluoro (n-
Is iso-amyl vinyl ether), perfluoro (bro
Moethyl vinyl ether) (FBrVE), perfluoro
B (iodoethyl vinyl ether) (IEVE) and the like; (v): an alkoxy group and an alkyl group (however, alkoxy
One part of the hydrogen atom of the di- or alkyl group is other than a fluorine atom
May be substituted with a halogen atom and
Oxygen atoms are interposed between the atoms to form an ether bond.
You may. ) Having 1 to 20 carbon atoms
Coxyalkyl vinyl ether), for example, perfluoro
B (methoxypropyl vinyl ether) (MPVE),
Perfluoro (methoxy isopropyl vinyl ether)
(MiPVE), perfluoro (propoxypropylbi)
Nyl ether), perfluoro (hexaoxytrideca)
Nyl vinyl ether) (TDVE: CF_Two= CFOC_TwoF
_Four(OCF_Two)_FiveOCF_Three), Perfluoro (heptaoxy)
Pentadecanyl vinyl ether) (PDVE: CF _Two=
CFOC_TwoF_Four(OCF_Two)₆OCF_Three), Perfluoro
(3,6-dioxy-1,2-trifluoromethylnonanyl vinyl
Ether) (P3VE: CF_Two= CFO [CF_Two(C
F_Three) O]_TwoC_ThreeF₇(Vi): a perfluoro group having 1 to 5 carbon atoms in the alkoxy group.
(Alkoxy vinyl ether), for example, perfluoro
(Methoxyvinyl ether), perfluoro (ethoxy)
Vinyl ether), perfluoro (propoxyvinyl ether)
-Tel) and the like.

Of these fluorine-containing monomers (a),
Carbon number 2 in which at least a part of hydrogen atoms is substituted by fluorine
To 8 unsaturated hydrocarbons (i), an alkyl group (at least part of the hydrogen atoms may be substituted with fluorine, and the remainder may be substituted with another halogen atom). Alkyl vinyl ether (iv), alkyl group and alkoxy group (provided that a part of the hydrogen atom of the alkoxy group and the alkyl group may be substituted with a halogen atom other than a fluorine atom, and that an oxygen atom is located between adjacent carbon atoms. One or more fluorine-containing monomers selected from perfluoro (alkoxyalkyl vinyl ether) (v) having 1 to 20 carbon atoms (an ether bond may be formed therebetween). The body is preferred.

In particular, among the unsaturated hydrocarbons (i) having 2 to 8 carbon atoms in which at least a part of the hydrogen atoms are substituted by fluorine, tetrafluoroethylene (TFE) and hexafluoropropene (HFP) are preferable. In the above perfluoro (alkyl vinyl ether) (iv), perfluoro (methyl vinyl ether) (FMVE), perfluoro (ethyl vinyl ether), perfluoro (n -Or iso-propyl vinyl ether), perfluoro (n
-, Iso- or tert-butyl vinyl ether) and perfluoro (n- or iso-amyl vinyl ether) are preferred, and among the above perfluoro (alkoxyalkyl vinyl ethers) (v), perfluoro (methoxyisopropyl vinyl ether) (MiPVE) Is preferred.

The unsaturated hydrocarbon monomer (b) can be copolymerized with the above vinylidene fluoride (a),
It can be used as long as it can be copolymerized with a copolymer component such as `` another fluorine-containing monomer '' (a), and as such an unsaturated hydrocarbon monomer (b), an olefin, preferably having a carbon number of Two
6 olefins, for example, ethylene, propylene, butene, etc .; unsaturated vinyl esters, preferably (total) unsaturated vinyl esters having 4 to 15 carbon atoms, for example, vinyl acetate; alkyl vinyl ethers, preferably alkyl groups having carbon atoms of 1-5 alkyl vinyl ethers, for example, methyl vinyl ether, ethyl vinyl ether and the like.

In such an unsaturated hydrocarbon monomer, a part of the hydrogen atoms contained therein may be replaced by halogen atoms such as fluorine and bromine. <Perfluoropolyether (c)> perfluoropolyethers (c) has the formula _{[I]: CH 2 = CHCH} 2 NHCOCF (CF 3) O [CF 2 CF (CF 3) O] m R f [OCF ( _{CF 3) CF 2] n OCF} (CF 3) CONHCH 2 CH = CH 2 ..... Represented by [I] and having an allyl group at both ends (CH ₂ ＣＨCHCH ₂ —)
Is a compound having

In the above formula [I], Rf is a perfluoroalkylene group having 2 to 6 carbon atoms, m and n are positive integers, and the sum (m + n) of both is 20 or more, preferably 3 or more.
It is 0 or more, particularly preferably 30 to 40. The weight average molecular weight (Mw) of such a perfluoropolyether (c) is usually 1,000 to 7000, preferably 5 to 7000.
000-7000. Such molecular weight (degree of polymerization)
When the perfluoropolyether (c) is used, the resulting fluorine-containing block copolymer tends to have excellent solvent resistance and cold resistance.

Such a perfluoropolyether (c)
Is manufactured, for example, according to the method described in the column of [Prior Art and Problems to be Solved by the Invention] in JP-A-10-101788. The hexafluoropropylene oxide (HFP) in this perfluoropolyether (c)
O) The number of ether bonds in the compound (c) increases in proportion to the amount of the unit, and the resulting fluorine-containing block copolymer tends to have improved cold resistance.

The amount of HFPO is measured by ¹⁹ F-NMR. Also such perfluoropolyether (c)
Examples thereof include the following. (i) In the above formula [I], Rf = CFCF ₃ O [CF ₂ CF (C
F ₃ ) O] _m CF ₂ CF ₂ [OCF (CF ₃ ) CF ₂ ] _n OCFC
It is F _3, an m + n = 32, weight average molecular weight (M
w) = 5747.

In the present invention, the copolymerizable compound as described above
When copolymerizing (a), (b) and (c), when the total of (a), (b) and (c) is 100 mol%, vinylidene fluoride
(a) is used in an amount of from 30 to 85 mol%, preferably from 40 to 85 mol%, particularly preferably from 60 to 85 mol%. However, the amount of perfluoropolyether (c) is calculated by converting it to the amount of hexafluoropropylene oxide (HFPO).

The "other monomer" (b) copolymerizable with the vinylidene fluoride (a) or the like includes the above "other fluorine-containing monomer" (a), an unsaturated hydrocarbon-based monomer. Monomer (olefinic compound) (b) in a total of 10 to 35 mol%, preferably 12 mol%.
Used in an amount of ３０30 mol%. In particular, the “other fluorine-containing monomer” (a) is one in all monomers ((a) + (b) + (c)).
In an amount of 0 to 30 mol%, in other words, in an amount of 5 to 40% by weight, the unsaturated hydrocarbon-based monomer (b) is converted into the total monomer ((a) +
(b) + (c)) in an amount of 10 mol% or less, in other words, 1
It is used in an amount of 0% by weight or less.

The perfluoropolyether (c) having allyl groups at both ends represented by the above formula [I] is HF
1 to 25 mol%, preferably 2 to 25 mol% in terms of PO amount
It is used in an amount of mol% ((a) + (b) + (c) = 100 mol%). When converted to a weight ratio, the above vinylidene fluoride
(a) is in an amount of 10 to 80% by weight, preferably 20 to 70% by weight, and the "other monomer" (b) is a total of ((a) +
(B)) in an amount of 10 to 50% by weight, preferably 20 to 40% by weight, the perfluoropolyether (c) having allyl groups at both ends represented by the above formula [I] is 5% in terms of HFPO. To 40% by weight, preferably 10 to 40% by weight ((a)
+ (B) + (c) = 100% by weight).

If the vinylidene fluoride (a) is used in an amount smaller than the above amount, the resulting fluorine-containing block copolymer tends to have low cold resistance, while if it is used in an amount larger than the above amount, the obtained fluorine-containing block copolymer has The rubber-like properties of the polymer (ie, rubber elasticity, ease of molding, chemical cross-linkability, Young's modulus of cross-linked rubber showing a low value of 1 to 10 MPa, etc.) tend to decrease. When vinylidene fluoride (a) is used in an amount within the above range, a fluorine-containing block copolymer excellent in both cold resistance and rubber properties tends to be obtained.

When the amount of the "other monomer" (b) is less than the above amount, the chemical resistance tends to decrease. When the amount is more than the above amount, copolymerization tends to be difficult. In addition, when the perfluoropolyether (c) is used in an amount smaller than the above amount, the desired solvent resistance may not be obtained and the effect of improving cold resistance may not be sufficiently exhibited, while it is obtained by using a larger amount than the above amount. There is a tendency that the viscosity of the copolymer becomes too high and the processability tends to decrease.If the perfluoropolyether (c) is used in an amount within the above range, the copolymer containing excellent solvent resistance, cold resistance and processability. There is a tendency to obtain a fluorine block copolymer.

The copolymerization reaction of vinylidene fluoride (a) with "other monomer" (b) and perfluoropolyether (c) is usually carried out in the presence of a catalyst, a solvent, etc. It is carried out by a solution polymerization method or a radical solution suspension polymerization method (polymer A of Example 1). This vinylidene fluoride
(a) and "other monomers" (b) and perfluoropolyether
The conditions for the copolymerization reaction with (c) vary depending on the polymerization method, the type of monomer used, the catalyst, etc., and are not determined unconditionally, but are usually at a temperature of about 0 to 80 ° C, preferably about 20 to 60 ° C. Done. At a reaction temperature higher than this, the molecular weight of the produced copolymer decreases, and the decomposition rate of the polymerization catalyst becomes too high, resulting in a decrease in efficiency.On the other hand, at a temperature lower than this, the polymerization rate decreases, and in practice, Absent. The polymerization pressure is preferably as high as possible, as long as a copolymer having a uniform composition can be obtained, but a pressure of about 100 kg / cm ² G or less is generally used.

Examples of the polymerization catalyst include radicals such as bis (heptafluorobutyl) peroxide, bis (isopropoxycarbonyl) peroxide, bis (cyclohexyloxycarbonyl) peroxide, bis (propoxycarbonyl) peroxide and bis (hexadecyloxycarbonyl) peroxide. And a polymerization initiator. Solvents, particularly fluorine-based solvents, include C ₇ F ₁₆ (trade name “P
F5070 "(manufactured by 3M), C ₈ F ₁₈ (trade name" PF5080 "(3M), the trade name of" FC7
7 "(manufactured by 3M), C ₈ F ₁₆ O (trade name" EF-
L102 "(Taupe Chemical Co., _{Ltd.), C 5 H 2 F 10} ( trade name" Vertrel XF "(Du Pont-Mitsui Fluorochemicals Co., Ltd.)," _{CF 3 CF 2 CHCl 2 + CClF} 2 CF 2 CHC
IF "(trade name" AK225 "(manufactured by Asahi Glass Co., Ltd.)) and the like.

In the present invention, the fluorinated block obtained by using a chain transfer agent such as methanol, ethanol, isopentane, diethyl malonate, carbon tetrachloride or the like, if necessary, in the above copolymerization reaction. The molecular weight of the copolymer (fluoroelastomer) can also be adjusted.
Thus, when vinylidene fluoride (a), `` other monomer '' (b) and perfluoropolyether (c) are copolymerized, vinylidene fluoride (a) and `` other monomer '' ( b) Vinylidene fluoride copolymer block (FKM)
However, a fluorinated block copolymer having a structure in which the perfluoropolyether (c) is bonded via cleaved allyl groups at both ends is obtained. <Fluorine-containing block copolymer> Such a fluorine-containing block copolymer comprises (a-1) a component unit derived from vinylidene fluoride, and (b-1) the above-mentioned vinylidene fluoride and perfluoropolyether ( Component units derived from `` other monomers '' as described above, which can be copolymerized with c), and (c-1)
And a perfluoropolyether component unit [Ia] derived from the above formula [I] and having a structure in which an allyl group double bond at both ends is cleaved, represented by the following formula [Ia]. Formula [Ia]:

[0033]

Embedded image

(In the formula [Ia], Rf is the same as Rf in the formula [I].
Is a perfluoroalkylene group having 2 to 6 carbon atoms, m and n are also positive integers as in the formula [I], and the sum of both is 20 or more, preferably 30 or more; More preferably, it is 30 to 40. ) Specific examples of such a fluorinated block copolymer will be described later.

When the (m + n) value of the perfluoropolyether component unit (c-1) is within the above range,
The fluorinated block copolymer has excellent balance of solvent resistance, cold resistance, and the like. In such a fluorinated block copolymer, each component unit (a-1), (b-1), (c-1) is a corresponding copolymerization monomer (a), (b), (c) The vinylidene fluoride component unit (a-1) is usually present in an amount of about 30 to 85 mol%, preferably about 40 to 85 mol%, particularly preferably 60 to 85 mol%. The component unit (b-1) derived from another monomer copolymerizable with the copolymerizing monomer such as the vinylidene fluoride (a) is usually 10 to 35 mol%, preferably 12 to 30 mol%. The perfluoropolyether (PFE) component unit (c-1) is usually present in an amount of 1 to 25 mol%, preferably 2 to 25 mol% in the amount of (a-1). ) + (B-1) + (c-1) = 1
00 mol%). The amount of the PFE component unit (c-1) is H
It is shown as a value converted to the FPO unit amount.

When the vinylidene fluoride component unit (a-1), which is a main component unit of the fluorinated block copolymer, is within the above range, the copolymer is excellent in both cold resistance and rubber-like properties. When the component unit (b-1) derived from the other monomer is in the above range, the copolymer is preferable because of excellent chemical resistance. Further, when the amount of the perfluoropolyether component unit (c-1) is in the above range, the obtained block copolymer has an appropriate viscosity, is excellent in workability, and is excellent in both solvent resistance and cold resistance.

In particular, the other monomer component units (b-1) copolymerizable with the above vinylidene fluoride (a) include: (a) the above vinylidene fluoride (a) and the following (b), (c) )) And other component units derived from “other fluorinated monomers” copolymerizable with the copolymerizable monomer, and (b): the copolymerizability of the above (a), (a), (c), etc. Component units derived from an unsaturated hydrocarbon-based monomer copolymerizable with a monomer, When selected from the above, the fluorine-containing monomer component unit (A), the copolymerizable monomer Correspondingly, at least a part of the hydrogen atom has 2 to 8 carbon atoms substituted by fluorine.
Perfluoroalkyl vinyl ether having 1 to 5 carbon atoms of an alkyl group (at least one part of a hydrogen atom may be substituted by fluorine and the remainder may be substituted by another halogen atom). (iv); an alkyl group and an alkoxy group (provided that a part of hydrogen atoms of the alkoxy group and the alkyl group may be substituted with a halogen atom other than a fluorine atom, and that an oxygen atom is interposed between adjacent carbon atoms. May form an ether bond.)
It is preferable that the monomer is derived from one or more selected from perfluoro (alkoxyalkyl vinyl ether) (v), and the above unsaturated hydrocarbon monomer component unit (b) ) Is derived from a monomer selected from olefins having 2 to 6 carbon atoms, unsaturated vinyl esters having 4 to 15 carbon atoms, and alkyl vinyl ethers having 1 to 5 carbon atoms in the alkyl group. It is desirable.

Specifically, for example, among the fluorine-containing block copolymers described below, reference numerals 15, 19, 24, 36,
37 and the like are preferable. The fluorine-containing block copolymer according to the present invention has rubber-like properties, and a vinylidene fluoride-based copolymer obtained by copolymerizing vinylidene fluoride (a) and `` other monomer '' (b) (FKM) block has a structure linked via cleaved allyl groups at both ends of perfluoropolyether (c) (PFE), for example,

[0039]

Embedded image

(N: number of repetitions). The molecular weight of such a fluorinated block copolymer is determined in consideration of the processability, mechanical properties, and the like of the fluorinated block copolymer. For example, the weight average molecular weight (Mw, measuring method:
GPC) is usually 1,000 to 100,000, preferably 10,000 to 100,000. Further, the solution viscosity η _sp / C as an index of the molecular weight is desirably about 0.3 to 2.0 dl / g, preferably 0.5 to 1.3 dl / g. In order to obtain a fluorine-containing block copolymer having a molecular weight corresponding to such a solution viscosity in such a range, a chain transfer agent such as ethyl malonate, acetone, or isopropanol may be used during the polymerization reaction as necessary, as described above. Is used.

The vulcanization characteristics of the fluorinated block copolymer (180% by “MDR2000” manufactured by Monsanto Co.)
Measured at 6 ° C for 6 minutes. DIN 53505, 5350
Based on 4. ) Has a TC90 (minute) value of usually 2.0 to 3.0.
0, and the minimum torque (ML) is usually 0.1 to
1.0dN ・ m, and the maximum torque (MH) is
Usually, it is in the range of 10.0 to 25.0 dN · m.

Further, for example, the tensile strength of the vulcanized product is usually in the range of 15 to 25 MPa, and the elongation at break is usually 150.
~ 250%, hardness (JIS-A compliant),
Usually in the range of 50 to 100, the compression set (“DI
Measured at 200 ° C. with a 25% compression over 70 hours in accordance with N53517. ) Is usually in the range of 30 to 75%, and the volume change rate (%) in the solvent resistance test (held in methanol at 40 ° C. for 70 hours) is usually in the range of 20 to 130%. (TR test, measured in methanol) (TR0), usually in the range of -35 to -45 ° C.

The method for vulcanizing (crosslinking) such a fluorine-containing block copolymer as described above is not particularly limited, and various conventionally known crosslinking methods can be employed. Crosslinking method (Organic peroxide is usually 0.1 to 10 per 100 parts by weight of the fluorine-containing block copolymer
Parts by weight), polyamine crosslinking, radiation,
An energy beam crosslinking method using an electron beam or the like can be used.

The fluorinated block copolymer according to the present invention can be used for other substances having peroxide crosslinking properties, for example,
Blended with silicone oil, silicone rubber, fluorophosphazene rubber, etc. at 140-220 ° C for 2-6
Co-crosslinking can also be performed by heating for about 0 minutes. Further, in the case of secondary crosslinking, 150 to 250 ° C. in an inert gas atmosphere such as in air or nitrogen gas.
The temperature may be maintained for about 1 to 50 hours.

When the fluorinated block copolymer of the present invention is vulcanized and used, the above peroxide crosslinking agent (for example,
In addition to a cross-linking agent such as triallyl isocyanurate), a component to be blended during the preparation of an ordinary vulcanized molded product, for example, a cross-linking aid; a filler such as talc and carbon black; a pigment such as zinc white; Accelerator (Example: "Perhexa 2.5B-4
0 "); a plasticizer; and additives such as a stabilizer.

As an example of the vulcanization molding method, each of the above-mentioned components is kneaded with a mixing roll, and the obtained kneaded material is heated at 150 to 200 ° C. for several minutes to several tens of minutes, for 100 to 100 minutes.
Press-vulcanized under a pressure condition of 150 kgf / cm ² to form a desired mold.
The vulcanization may be sufficiently performed by performing oven vulcanization at 250 ° C. for about 15 to 25 hours.

As described above, examples of the fluorine-containing block copolymer according to the present invention include the following, and as described above, the numbering (37) is preferred. Note that, for example, “(VdF / HFP) (PF
In (E), the former “(VdF / HFP)” indicates a vinylidene fluoride-based copolymer block (FKM). For example, (1): vinylidene fluoride / hexafluoropropene / perfluoropolyether copolymer ((VdF / HFP) (PFE) copolymer), (2): vinylidene fluoride / hexafluoropropene / 1
-Bromo-2,2-difluoroethylene / perfluoropolyether copolymer ((VdF / HFP / BDFE) (PFE) copolymer), (3): vinylidene fluoride / hexafluoropropene / perfluoro (bromoethyl) (Vinyl ether) / perfluoropolyether copolymer ((VdF / HFP / FBrVE) (PFE) copolymer), (4): vinylidene fluoride / hexafluoropropene / bromotrifluoroethylene / perfluoropolyether copolymer ((VdF / HFP / BTFE) (PFE) copolymer), (5): vinylidene fluoride / hexafluoropropene / 1
-Iodo-2,2-difluoroethylene / perfluoropolyether copolymer ((VdF / HFP / IDFE) (PFE) copolymer), (6): vinylidene fluoride / hexafluoropropene / perfluoro (iodoethyl) (Vinyl ether) / perfluoropolyether copolymer ((VdF / HFP / IEVE) (PFE) copolymer), (7): vinylidene fluoride / hexafluoropropene / iodotrifluoroethylene / perfluoropolyether copolymer ((VdF / HFP / ITFE) (PFE) copolymer), (8): vinylidene fluoride / tetrafluoroethylene / hexafluoropropene / perfluoropolyether copolymer ((VdF / TFE / HFP) (PFE) (9): vinylidene fluoride / perfluoro (methyl vinyl ether) / perfluoropolyether copolymer ((V
dF / FMVE) (PFE) copolymer), (10): vinylidene fluoride / trichlorofluoroethylene / perfluoropolyether copolymer ((VdF / CTF
E) (PFE) copolymer), (11): vinylidene fluoride / hexafluoropropene /
Ethylene / perfluoropolyether copolymer ((VdF / H
(FP / E) (PFE) copolymer), (12): vinylidene fluoride / tetrafluoroethylene /
Perfluoro (methyl vinyl ether) / perfluoropolyether copolymer ((VdF / TFE / FMVE) (PFE) copolymer), (13): vinylidene fluoride / trichlorofluoroethylene / ethylene / perfluoropolyether copolymer (14): Vinylidene fluoride / perfluoro (methyl vinyl ether) / ethylene / perfluoropolyether copolymer ((VdF / FMVE / E) ((VdF / CTFE / E) (PFE) copolymer) (PFE) copolymer), (15): vinylidene fluoride / tetrafluoroethylene /
Perfluoro (methyl vinyl ether) / ethylene / perfluoropolyether copolymer ((VdF / TFE / FMVE / E) (P
FE) copolymer), (16): vinylidene fluoride / tetrafluoroethylene /
Trichlorofluoroethylene / perfluoropolyether copolymer ((VdF / TFE / CTFE) (PFE) copolymer), (17): vinylidene fluoride / tetrafluoroethylene /
Hexafluoropropene / ethylene / perfluoropolyether copolymer ((VdF / TFE / HFP / E) (PFE) copolymer), (18): vinylidene fluoride / tetrafluoroethylene /
Trichlorofluoroethylene / ethylene / perfluoropolyether copolymer ((VdF / TFE / CTFE / E) (PFE) copolymer), (19): vinylidene fluoride / tetrafluoroethylene /
Hexafluoropropene / perfluoro (methyl vinyl ether) / perfluoropolyether copolymer ((VdF
/ TFE / HFP / FMVE) (PFE) copolymer), (20): vinylidene fluoride / trichlorofluoroethylene / tetrafluoroethylene / perfluoro (methyl vinyl ether) / perfluoropolyether copolymer ((VdF / CTFE) / TFE / FMVE) (PFE) copolymer), (21): vinylidene fluoride / tetrafluoroethylene /
Hexafluoropropene / perfluoro (methyl vinyl ether) / ethylene / perfluoropolyether copolymer ((VdF / TFE / HFP / FMVE / E) (PFE) copolymer), (22): vinylidene fluoride / trichlorofluoro Ethylene / tetrafluoroethylene / perfluoro (methyl vinyl ether) / ethylene / perfluoropolyether copolymer ((VdF / CTFE / TFE / FMVE / E) (PFE) copolymer), (23): vinylidene fluoride / Tetrafluoroethylene /
Perfluoro (methyl vinyl ether) / 1-bromo-
2,2-difluoroethylene / perfluoropolyether copolymer ((VdF / TFE / FMVE / BDFE) (PFE) copolymer), (24): vinylidene fluoride / tetrafluoroethylene /
Perfluoro (methyl vinyl ether) / perfluoro (bromoethyl vinyl ether) / perfluoropolyether copolymer (VdF / TFE / FMVE / FBrVE) (PFE) copolymer, (25): vinylidene fluoride / tetrafluoroethylene /
Perfluoro (methyl vinyl ether) / 1-iodo-
2,2-difluoroethylene / perfluoropolyether copolymer ((VdF / TFE / FMVE / IDFE) (PFE) copolymer), (26): vinylidene fluoride / tetrafluoroethylene /
Perfluoro (methoxypropyl vinyl ether) / perfluoropolyether copolymer ((VdF / TFE / MPVE) (P
FE) copolymer), (27): vinylidene fluoride / tetrafluoroethylene /
Perfluoro (methoxypropyl vinyl ether) / ethylene / perfluoropolyether copolymer ((VdF / TFE
/ MPVE / E) (PFE) copolymer), (28): vinylidene fluoride / tetrafluoroethylene /
Perfluoro (methoxypropyl vinyl ether) / perfluoro (bromoethyl vinyl ether) / perfluoropolyether copolymer ((VdF / TFE / MPVE / FBrVE) (P
FE) copolymer), (29): vinylidene fluoride / tetrafluoroethylene /
Perfluoro (methoxy isopropyl vinyl ether)
/ Perfluoropolyether copolymer ((VdF / TFE / MiPV
E) (PFE) copolymer), (30): vinylidene fluoride / tetrafluoroethylene /
Perfluoro (propoxyisopropyl vinyl ether) / perfluoropolyether copolymer ((VdF / TFE / P
iPVE) (PFE) copolymer), (31): vinylidene fluoride / tetrafluoroethylene /
Perfluoro (hexaoxytridecanyl vinyl ether) / perfluoropolyether copolymer ((VdF / TFE / T
(DVE) (PFE) copolymer), (32): vinylidene fluoride / tetrafluoroethylene /
Perfluoro (heptaoxypentadecanyl vinyl ether) / perfluoropolyether copolymer ((VdF / TFE
/ PDVE) (PFE) copolymer), (33): vinylidene fluoride / tetrafluoroethylene /
Perfluoro (3,6-dioxy-1,2-trifluoromethylnonanyl vinyl ether) / perfluoropolyether copolymer ((VdF / TFE / P3VE) (PFE) copolymer), (34): fluorination Vinylidene / tetrafluoroethylene /
Perfluoro (hexaoxytridecanyl vinyl ether) / perfluoro (bromoethyl vinyl ether) / perfluoropolyether copolymer ((VdF / TFE / TDVE / FBr
VE) (PFE) copolymer), (35): vinylidene fluoride / tetrafluoroethylene /
Perfluoro (heptaoxypentadecanyl vinyl ether) / perfluoro (bromoethyl vinyl ether) /
Perfluoropolyether copolymer ((VdF / TFE / PDVE / F
(BrVE) (PFE) copolymer), (36): vinylidene fluoride / tetrafluoroethylene /
Perfluoro (methoxy isopropyl vinyl ether)
/ Perfluoro (bromoethyl vinyl ether) / perfluoropolyether copolymer ((VdF / TFE / MiPVE / FBrV
E) (PFE) copolymer), (37): vinylidene fluoride (VdF) / perfluoro (methyl vinyl ether) (FMVE) / hexafluoropropylene
(HFPO) / perfluoropolyether (PFE) copolymer ((Vd
F / FMVE / HFPO) (PFE) copolymer).

Such a fluorinated block copolymer, especially a vulcanizate thereof, is excellent in solvent resistance and cold resistance, and is used in fields where excellent solvent resistance, chemical resistance, etc. are required, for example, films and seals. Materials, gaskets, O-rings, coated cloths, wire insulation coatings, hoses, protective coatings, and the like are suitably used in the fields of the semiconductor industry, medical materials, and the food industry.

[0049]

The fluorine-containing block copolymer according to the present invention comprises a perfluoropolyether (c) component unit in the main chain, that is, a vinylidene fluoride (a) component unit as a main component unit, and By introducing in a block manner into the main chain composed of the other monomer (b) component unit bonded thereto, fluorine-containing (co) composed of vinylidene fluoride (a) and other monomer (b) The fluorine content is higher than that of the polymer, so that the solvent resistance is improved and the cold resistance is also improved.

The fluorinated block copolymer of the present invention having solvent resistance and cold resistance as described above is particularly suitably used as a vulcanization molding material or the like for a fuel oil seal material. Note that, since ordinary fluororubber having vinylidene fluoride as a main component unit does not have an ether bond, it is generally not possible to mix perfluoropolyether oil as a plasticizer in the fluororubber from the viewpoint of compatibility. Since the fluorine-containing copolymer of the present invention has an appropriate amount of ether bond,
Perfluoropolyether oil can be blended as a plasticizer.

[0051]

EXAMPLES Hereinafter, the method for producing a fluorinated block copolymer and the fluorinated block copolymer according to the present invention will be described more specifically based on examples, but the present invention is not limited to these examples. Not done. The components used in the following Examples and Comparative Examples are as follows.

Note (i): "MT-carbon black", carbon black manufactured by SEIST Co., Ltd. Note (ii): ZnO (two types of zinc white), manufactured by Ishihara Sangyo Co., Ltd. Note (iii): "Talc M-60", Talc manufactured by Nippon Kasei Co., Ltd. Note (iv): "Perhexa 2.5B-40", a vulcanization accelerator manufactured by NOF Corporation.

[0053]

Example 1 and Comparative Example 1 The following components were kneaded with a 4-inch mixing roll, and the obtained kneaded material was mixed with the mixture for 18 minutes.
Press vulcanization at 0 ° C. for 10 minutes and 22 ° C. at 230 ° C.
Time oven vulcanization was performed. Polymer A or B 100 parts by weight MT-carbon black (Note (i)) 30 parts by weight ZnO (two kinds of zinc white) (Note (ii)) 6 parts by weight Talc M-60 (Note (iii)) 6.7 parts by weight Part Perhexa 2.5B-40 (Note (iv)) 1.34 parts by weight The obtained vulcanized product was measured for each item shown in Table 1 below.

The components shown in the table are as follows. Polymer A (used in Example 1) : vinylidene fluoride [VdF] / perfluoro (methyl vinyl ether)
[FMVE] / perfluoropolyether [PFE] =
75.9 / 15.9 / 6.2 (mol%) (PFE amount is
<Value converted to the amount of HFPO (hexafluoropropylene oxide)) <Production method of polymer A> In an autoclave having a capacity of 500 mL, (a) vinylidene fluoride [VdF] 44 g (b) perfluoro (methyl vinyl ether) [FMVE] 32 g ( c) the following PFE 13.4 g having both ends allyl <PFE> formula _{[I]: CH 2 = CHCH} 2 NHCOCF (CF 3) O [C
F ₂ CF (CF ₃ ) O] _m Rf [OCF (CF ₃ ) CF ₂ ] _n O
CF (CF ₃ ) CONHCH ₂ CH = CH ₂ (However, in the formula [I], Rf = “— CF ₂ CF ₂ —”;
m + n = 32 and Mw = 5747. (D) 0.25 g of ICF ₂ CF ₂ Br (e) 108.5 g of C ₇ F ₁₆ (PF5070, manufactured by 3M) (f) 117.3 g of ion-exchanged water was charged and heated to 25 ° C. (Heptafluorobutyryl) peroxide (5% dilution; Parloyl FB)
5Nippon Yushi Co., Ltd.) (18.0 g) was charged to initiate a polymerization reaction. The stirring speed was 620 rpm. After reacting for 505 minutes, the mixture was cooled and unreacted gas was released to stop the polymerization reaction.

The reaction mixture was separated by filtration, the solid substance was dried under reduced pressure, washed twice with 150 ml of a fluorinated solvent (trade name “FC77” manufactured by 3M), filtered, and dried under reduced pressure.
62.9 g of fluorine-containing block copolymer (recovery rate 70%)
I got Polymer B (used in Comparative Example 1) ; vinylidene fluoride [VdF] / perfluoromethyl vinyl ether [FMVE] =
82.2 / 17.8 (mol%) <Production method of polymer B> In a pressure-resistant container with a stirrer having a capacity of 100 liters, 3660 g of deoxygenated and demineralized water was added.
154 g of ammonium perfluorooctanoate as a surfactant, 1 ammonium persulfate as a polymerization initiator
1 g, ICF ₂ CF ₂ B as a crosslinking site introducing compound
r: 50g and _{CF 2 BrCF 2 OCF = CF 2} : 12
1 g of Na ₂ HPO ₄ .12H ₂ O as a buffer
After charging 0 g, the whole content was cooled to -30 ° C.

Next, after sufficiently purging the internal space with pure nitrogen, it was purged and pressed into the vessel in the order of 6530 g of perfluoromethyl vinyl ether (FMVE) and 8930 g of vinylidene fluoride (VdF). Thereafter, the temperature inside the system was raised to 50 ° C., and after stirring was started after confirming the melting of the ice, the reaction proceeded, and the pressure of 36 kg / cm ² was 1
After 4 hours, it decreased to 0 kg / cm ² . After confirming that no further pressure drop was observed, the unreacted mixed gas was purged to stop the polymerization reaction.

An 8% aqueous sodium chloride solution was added to the obtained aqueous emulsion to coagulate the resulting copolymer, washed with water and dried to obtain a rubbery random copolymer (Polymer B) 13.5.
20 g (90% recovery) were obtained. With respect to the obtained vulcanized product, each item shown in the following Table 1 was measured. <Test conditions> The test conditions in the table are as follows. Vulcanization properties: 18 with Monsanto “MDR2000”
The temperature was kept at 0 ° C. for 6 minutes, and the vulcanization characteristics were measured. Vulcanization properties: Based on "DIN53505, DIN53504". Compression set: 200 ° C. in accordance with “DIN 53517”
At 25% compression over 70 hours (hr).

(3 pieces of test piece punching, 6 mm
Thickness) Solvent resistance test: Using a glass test tube with a condenser,
It was kept at 40 ° C. for 70 hours to measure the solvent resistance. Low temperature property test: TR according to (ASTM D-1329)
The test was measured in methanol.

[0059]

[Table 1]

Claims (10)

[Claims] (A) vinylidene fluoride; (b) another monomer copolymerizable with the vinylidene fluoride; and (c) formula [I]: CH ₂ ＝ CHCH ₂ NHCOCF (CF ₃ ). _{O [CF 2 CF (CF 3} ) O] m Rf [OCF (CF 3) CF 2] n OCF (CF 3) CONHCH 2 CH = CH 2 ... [I] (In the formula [I], Rf is a perfluoroalkylene group having 2 to 6 carbon atoms, m and n are positive integers, and the sum of both is 20 or more. ) And a perfluoropolyether having an allyl group at both ends represented by the formula (1). 2. The vinylidene fluoride (a): 40 to 85 mol%, and the other monomer (b) copolymerizable with the vinylidene fluoride:
10 to 35 mol%, and the above perfluoropolyether (c) [calculated in terms of hexafluoropropylene oxide (HFPO)]: 1 to 2
The method for producing a fluorine-containing block copolymer according to claim 1, wherein 5 mol% ((a) + (b) + (c) = 100 mol%) is copolymerized. 3. The other monomer (b) copolymerizable with vinylidene fluoride comprises: (a) a fluorine-containing monomer other than vinylidene fluoride, and (b) an unsaturated hydrocarbon-based monomer. The method for producing a fluorinated block copolymer according to any one of claims 1 to 2, wherein the monomer is at least one monomer selected from the group consisting of: 4. The fluorine-containing monomer (a) has a carbon atom of at least a part of which is hydrogen-substituted.
To 8 unsaturated hydrocarbons; a perfluoroalkyl vinyl ether having 1 to 5 carbon atoms in an alkyl group (at least one part of a hydrogen atom may be substituted with fluorine and the remainder may be substituted with another halogen atom); Alkyl group and alkoxy group (provided that a part of the hydrogen atom of the alkoxy group and the alkyl group may be substituted by a halogen atom other than a fluorine atom, and that an oxygen atom is interposed between adjacent carbon atoms to form an ether bond; May be formed) having 1 to 2 carbon atoms.
4. The method for producing a fluorinated block copolymer according to claim 3, wherein the fluorinated block copolymer is at least one member selected from the group consisting of 0 perfluoro (alkoxyalkyl vinyl ether). 5. The unsaturated hydrocarbon monomer (b) is an olefin having 2 to 6 carbon atoms, an unsaturated vinyl ester having 4 to 15 carbon atoms, or an alkyl vinyl ether having an alkyl group having 1 to 5 carbon atoms. The method for producing a fluorinated block copolymer according to any one of claims 3 to 4, which is at least one member selected from the group consisting of: 6. A component unit derived from (a-1) vinylidene fluoride, (b-1) a component unit derived from a monomer other than the above vinylidene fluoride, and (c-1) And a perfluoropolyether component unit represented by the following formula [Ia]: [Ia]: (In the formula [Ia], Rf is a perfluoroalkylene group having 2 to 6 carbon atoms, m and n are positive integers, and the sum of both is 20 or more.) 7. The vinylidene fluoride component unit (a-1) having a content of 4
In an amount of 0 to 85 mol%, other monomer component units (b-1) other than the above vinylidene fluoride
Is an amount of 10 to 35 mol%, and the perfluoropolyether component unit (c-1) [calculated in terms of hexafluoropropylene oxide (HFPO) unit] is 1 to 25 mol% ((a-1) + (b-1) + (c-1) = 10
The fluorine-containing block copolymer according to claim 6, which is present in an amount of 0 mol%). 8. The above monomer unit (b-1) copolymerizable with vinylidene fluoride may comprise: (a) a component unit derived from a fluorine-containing monomer other than the above vinylidene fluoride The fluorine-containing block according to any one of claims 6 to 7, which is at least one monomer component unit selected from the group consisting of: and (b) a component unit derived from an unsaturated hydrocarbon monomer. Copolymer. 9. The fluorine-containing monomer unit (a) has a carbon atom of at least a part of which is hydrogen-substituted.
To 8 unsaturated hydrocarbons; a perfluoroalkyl vinyl ether having 1 to 5 carbon atoms in an alkyl group (at least one part of a hydrogen atom may be substituted with fluorine and the remainder may be substituted with another halogen atom); Alkyl group and alkoxy group (provided that a part of the hydrogen atom of the alkoxy group and the alkyl group may be substituted by a halogen atom other than a fluorine atom, and that an oxygen atom is interposed between adjacent carbon atoms to form an ether bond; May be formed) having 1 to 2 carbon atoms.
9. The fluorinated block copolymer according to claim 8, which is a component unit derived from one or more perfluoro (alkoxyalkyl vinyl ethers). 10. The unsaturated hydrocarbon monomer component unit
(B) is derived from one or more selected from olefins having 2 to 6 carbon atoms, unsaturated vinyl esters having 4 to 15 carbon atoms, and alkyl vinyl ethers having 1 to 5 carbon atoms in the alkyl group. The fluorinated block copolymer according to any one of claims 8 to 9, which has been prepared.