JP3399591B2 - Method for producing ethylene-tetrafluoroethylene copolymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION The present invention relates to ethylene-tetrafluoro
Such as ethylene copolymer (hereinafter abbreviated as ETFE).
Tylene-tetrafluoroethylene copolymer (hereinafter referred to as E
TFEs),Molding
Efficient ETFEs with good heat resistance, heat resistance and chemical resistance
To a method of manufacturing. [0002] 2. Description of the Related Art ETFEs,Heat resistance, solvent resistance, chemical resistance
Because it is a polymer material with excellent properties,
Utilized in various applications. [0003] As a method for producing ETFEs, a solution polymerization method is used.,
Suspension polymerization methodandEmulsion polymerization is known and is known as solution polymerization.
Chlorofluoroca
Inert such as carbonMediumBut high molecular weightETFEsGive
And polymerization speedIs fastFrom the point of view, usually used
Have been. As a specific example of the chlorofluorocarbon
Means trichlorofluoromethane, dichlorodifluorometh
Tan, trichlorotrifluoroethane, dichlorotetra
Examples include fluoroethane, but from the point of handling.
Lichlorotrifluoroethane is mainly used. [0004]NearbyDepletion of the ozone layer will result in global environmental damage
Has been raised internationally as a problem.
Chlorofluorocarbons are pointed out and globally abolished
I'm facing you. For this reasonETFEsMadeTo buildUse
The need to stop using chlorofluorocarbons
coming. Also, ETFEsWhen manufacturingAs a polymerization medium
hand,Represented by the above-mentioned trichlorotrifluoroethane
When using chlorofluorocarbon, it is slight
Is chlorofluorocarbon,Rimmer growing end boom
Reacts with chlorine, and chlorine is bonded to the end of the polymer molecular chain.
ToETFEsButGenerateI do. At the end of this polymer molecular chain
Carbon-chlorine bond has thermal stabilityLow, highLong time release in warm
PutETFEsColoringLet me do it.AlsoThis
Una ETFEsUse as wire covering materialWhen,Coating
Chlorine when shapedContainedPolymer ends decompose,Corrosion of core wireRaw
causeYou. U.S. Pat. No. 5,182,342ToIs chlorine
Specific hydrofluorocarbons not includedDuring ~ETF at
EKindofManufacturing methodExampleHave beenButThe ETFEs areMinute
The melt size is too high for melt moldingwon. [0006] SUMMARY OF THE INVENTION,Rimmer minutes
Chlorine is bonded to the end of the child chainETFEsButGenerateLet
ET with excellent moldability, heat resistance, solvent resistance, and chemical resistance
To provide a method for economically and efficiently producing FEs.
For the purposeYouYou. [0007] Means for Solving the Problems The present inventors have achieved the above object.
As a result of intensive research to achieve
Using a specific hydrofluorocarbon,Chain transfer agent
Of ETFE and concentration of ETFE at the end of polymerizationAdjust
Is obtained byETFEsMelt flow rateTo
To a certain rangeControlThat can achieve its purpose
Was found. That is, the present invention relates to the presence of a chain transfer agent.
under,In polymerization mediumsopolymerizationTo makeByToTEFEsMade of
LawHaving 3 to 10 carbon atoms as a polymerization mediumSaturationYes
Drofluorocarbon (however, 1 ≦ number of hydrogen atoms ≦
Elementary atoms),E with a default flow rate of 1 to 30
Get TFEsAs shown, the amount of chain transfer agent added and the polymerization
The concentration of ETFEs at the timeET characterized by the following
Provide FE manufacturing methodsYou. In the present invention, tetrafluoroethylene is usually used.
Chilen(Hereinafter referred to as TFE)/ethylene(Hereinafter E
That. )The charged molar ratio of 30/70 to 95/5, especially
40/60 to 90/10SaturationHydrofluoroca
In the BonnTFEWhenE andTo make ETFE
Can be built. ETFEs other than ETFE include:TF
E and EIn addition to a small amount of a comonomer further copolymerized
Is mentioned. These comonomers include,CF_Two= C
FCl, CF_Two= CH_TwoSuch as fluoroethylenes, CF
_Two= CFCF_Three, CF_Two= CHCF_ThreeSuch as fluoroprop
Rens, CF_ThreeCF_TwoCF_TwoCF_TwoCH = CH_Two ,CF_ThreeCF
_TwoCF_TwoCF_TwoCF = CH_TwoPerfluoroalkyl groups such as
(Perfluoroalkyl) ethylene having 4 to 12 carbon atoms
,R ^f (OCFXCF_Two)_mOCF = CF_Two(In the formulaR ^f
Is a perfluoroalkyl group having 1 to 6 carbon atoms, X is fluorine
An atom or a trifluoromethyl group, m is an integer of 1 to 5
Represent. ) And the like, CH_Three
OC (= O) CF_TwoCF_TwoCF_TwoOCF = CF_Two ,FSO_Two
CF_TwoCF_TwoOCF (CF_Three) CF_TwoOCF = CF_TwoSuch as
Has a group that can be easily converted to a carboxylic acid group or a sulfonic acid group.
Vinyl ethers, Propylene, isobutylene, etc.
OlefinsSuchToAlone or a combination of two or more
Can also be used. ThisCopolymerization ratio of these comonomers
Is, 30 mol% or less, especially about 0.1 to 15 mol%DegreeHope
Good. The polymerization medium used in the present invention is,H
NatomAnd at least oneAndAt most fluorineatomof
Number of hydrogens equal to the numberatomAnd 3-10 carbonsatomOnly
Consisting of saturatedHydrofluorocarbonIt is. Charcoal
ElementaryatomIs less than 2ThenBoiling point too lowhandPolymerization pressure is high
Rises again,11 or moreThenBoiling point is too highHeavy
AfterETFEsIt is difficult to separate the polymerization medium
This is disadvantageous in manufacturing. Also, fluorineatomNumber ofis more than
hydrogenatomExistsHydrogen atomIs a chain transferWill be a point
so, Undesirable. Particularly desirable polymerization media are, Cycl
o-C_FourF_FourH_Four, C_FourF₈H_Two, C_FiveF₁₁H, C_FiveF_TenH_Two,
C₆F₁₃H, C₆F₁₂H_TwoOr C₆F₉H_FiveAnd specifically
Is,1,1,2,2-tetrafluorocyclobutane, C
F_TwoHCF_TwoCF_TwoCF_TwoH, CF_ThreeCFHCF_TwoCF_TwoC
F_Three, CF_ThreeCF_TwoCF_TwoCF_TwoCF_TwoH, CF_ThreeCF_TwoCFH
CF_TwoCF_Three, CF_ThreeCFHCFHCF_TwoCF_Three, CF_TwoHC
F_TwoCF_TwoCF_TwoCF_TwoH, CF_TwoHCFHCF_TwoCF_TwoC
F_Three, CF_ThreeCF_TwoCF_TwoCF_TwoCF_TwoCF_TwoH, CF_ThreeCH
(CF_Three) CF_TwoCF_TwoCF_Three ,CF_ThreeCF (CF_Three) CFH
CF_TwoCF_Three, CF_ThreeCF (CF_Three) CFHCFHCF_Three,
CF_ThreeCH (CF_Three) CFHCF_TwoCF_Three , CF_ThreeCF_TwoCF
_TwoCF_TwoCH_TwoCH_ThreeAnd so on. In the present invention, as the polymerization medium,Bored
sumInert such as water on hydrofluorocarbonMediumIncluding
It can also be used. The amount of polymerization medium used is heavy
Depends on the type of monomer to be combined.Can be changedBut monomer
3 to 100 times the total weight, preferably 5 to 100 times
50 times the amount. In the present invention, the polymerization method is a solution weight.
Either a legal or suspension polymerization method can be employed. Ma
Was, HeavySynthetic initiators include fluorine-based and hydrocarbon-based initiators.
Organic peroxides and azo compounds can be used.
Organic and hydrocarbon organic peroxidesETFEs
Is preferred in terms of thermal stability. With fluorine-based organic peroxides
Then, for example, (ClCF_Two(CF_Two)_nCOO)_TwoSuch as
Screw(Chlorofluoroacyl)-OkiShiDo, (CF
_Three(CF_Two)_nCOO)_Two, (CF_ThreeCF_TwoCF_Two(CF (C
F_Three) CF_TwoO)_nCF (CF_Three) COO)_TwoSuch asScrew
(Perfluoroacyl)-OkiShiDo, (HCF_Two(C
F_Two)_nCOO)_TwoSuch asScrew(ω-Hydroperfluo
Loacyl)-OkiShiFor example (where,n
Is0 toInteger of 8Is shown.). Hydrocarbon organic
As a peroxide, for example,TheAcetyl peroxyShiDoThe
Isobutyryl peroxyShiDiacyl peroxyShi
De, diisopropyl peroxydicarbonate, di-n
-Peroxy, such as propylperoxydicarbonate
Dicarbonate, t-butyl peroxyisobutyrate
T, t-butyl peroxypivalate, t-butyl
3,5,5-trimethylPeroxyHexanoate, etc.
And the like. Polymerization initiator
The amount used may vary as appropriate depending on the type, copolymerization reaction conditions, etc.
ChangeCanHowever, usually, the whole monomer to be polymerized is
0.005 to 5% by weight, especially 0.05 to 0.5% by weight
% Is adopted. The present inventionInAndETFEsThe molecular weight of
Chain transfer for control purposesAgentIs usually added.
ofChain transfer agentMust be soluble in the polymerization medium. Only
And a large chain transfer constantChain transfer agentIs,Molecular weight control
Considering ease, it is only necessary to dissolve in the polymerization medium
No. Also, The chain transfer agentHas a small ozone depletion potential
Is desirable. Meet these demandsChain transfer agentIs
For example, hydrocarbons such as hexane, CF_TwoH_Two
Such as, A saturated hydrofluorocarbon as the polymerization medium
Other thanHydrofluorocarbons, CF_ThreeCF_Two
CHCl_TwoSuch as HideBChlorofluorocarbons,
Ketones such as acetone, methanol, ethanol, etc.
Alcohols,Mercapta such as chill mercaptan
And others. The amount of addition,UseChain transfer agentChain transfer
Varies depending on the magnitude of the dynamic constantCan be changedBut to the polymerization medium
About 0.01% to 50% by weightUntilIs adoptedCan
You. [0015]ClearlyInIs,ETFEsThe molecular weight of
For control purposesETFEsAdjust the concentration.
ETFEsWhat is concentration,Polymerization medium at the end of polymerizationVolumeTo
ObtainedETFEs0.03 ~
0.2g /mLofWithin rangeDetermined as appropriateCanYou.ETFEs
ofThe concentration is 0.03 g /less than mLSo productivityLowAgain
0.2g /Over mLNow the resulting slurry becomes sandy,
It is not preferable in the manufacturing process. preferableETFEsDark
The degree is 0.05-0.1g /mLIt is. The present inventionAtHas a wide rangepolymerizationCondition
Adopted without particular limitationCanYou. For example, heavyJoint temperatureEvery time
Starts polymerizationAgentOptimal value depending on the type ofToSelectionCanTo
However, usually about 0 ~ 100 ℃, especially about 30 ~ 90 ℃
RecruitCanYou. Also,polymerizationPressure is also selected appropriatelyCanBut usually
Is 2 to 100 kg / cm^Two, Especially 5-20kg / cm^TwoAbout
It is desirable to adopt degrees. In the present invention,
polymerizationThe polymerization can be carried out advantageously without the need for pressureBut, Update
High pressureAndDecompression stripCan be adoptedYou. MaWasBatch type, continuous
Appropriate operation such as continuation typeCan be adoptedYou. [0017] Melt of ETFEs obtained in the present invention
The flow rate is 1 to 30InYou. Melt floray
Is1If smaller, molding is difficult, and30Greater than
WhenETFEsMechanicalSpecialPoor sexTo. Preferred melt flow
Rate is2 to 28, especially2-20.here
The melt flow rate is defined by ASTM-D3159.
This is a value measured by the specified method. [0019]ETFEsThe melt flow rate ispolymerization
ETFEs at the endConcentration and chain transfer agentAmount ofTones
By settingCan controlYou. LowETFE at the end of polymerization
Kindconcentration,OrManyChain transfer agentAmount addedThen,bigI Mel
Flow rateETFEsAnd conversely highpolymerization
ETFEs at the endConcentration, orFewChain transfer agentAmount added
Then,smallHigh melt flow rateETFEsIs obtained
You. [0020] Embodiment 1 Stainless steel with an inner volume of 1.2 literssteelMadepolymerizationDegas container
And CF as a polymerization medium_ThreeCF (CF_Three) CFHCFHC
F_Three of1200 g, n-pentane as a chain transfer agentof
0.8g,TFE45g,E's3.7 g,
(Perfluorobutyl) ethyleneofCharge 0.8g
It is. The temperature was maintained at 65 ° C., and t-butyl was used as a polymerization initiator.
10 weight of tilperoxyisobutyrate% Dissolutionliquid(Dissolution
Medium: 1,1,2-trichloro-1,2,2-trifluoro
Ethane)3mLChargePolymerizationWas started.polymerization
Medium, in the systemTFE / EMixed gas (molar ratioTFE/E=
53/47)polymerizationPressure 17.5 g / cm^Two
Held. After 6 hours, 85 g of white copolymer is slurry.
ー StatesoGot.The copolymer concentration was 0.116 g /mL
Met. The copolymer is,270 ° C melting point, starting point of thermal decomposition
340 ° C., melt flow rate 7.2, 300
℃In the form ofA good compression molded article without coloring was obtained.compression
MoldingGenuineTensile strength is 420kg / cm^Two, Tensile elongation is 5
40%.compressionHold the molded product at 250 ° C for 3 days
Even coloring is almostWhowon. Embodiment 2 As a chain transfer agent,Methanol instead of n-pentane
ofExcept for the 3.9g,In the same manner as in Example 1,
Polymerization was performed. After 6 hours, 74 g of the white copolymer
Lee statesoObtained. The copolymer is,272 ° C, heat
Decomposition starting point: 345 ° C., melt flow rate: 9.6
300 ° CIn the form ofGives good compression molded products without coloring
I got it.compressionMoldingGenuineTensile strength is 418kg / cm^Two, Pull
Tensile elongation was 440%.compressionMolded product at 250 ℃ 3
Coloring is almost constant even after holding for daysWhowon. Embodiment 3 As a polymerization medium,CF_ThreeCF (CF_Three) CFHCFHCF
_ThreeofTeensRatherTo CF_ThreeCF_TwoCFHCFHCF_Three of1300g
ToExcept for the charge,Polymerization was carried out in the same manner as in Example 1.
Was(Where CF _Three CF _Two CFHCFHCF _Three Is TFE
And hexafluoropropylene with AlCl _Three / CFCl _Three
Using a Pd / C catalyst to convert the adduct obtained using
It is a compound obtained by hydrogenation. ). After 4.5 hours
90g of white copolymer in slurrysoObtainedWas.Both
The polymer concentration is 0.109 g /mLMet. The copolymer
Is,Melting point 268 ° C, pyrolysis starting point 355 ° C, melt flow
The rate is 5.0 and theIn the form ofColorless
Good compression molded articles were given.compressionMoldingGenuineTensile strength is 4
60kg / cm^TwoThe tensile elongation was 470%.compression
Even if the molded product is kept at 250 ° C for 3 days, coloring is almostWho
won. Comparative Example 1 0.1 g of chain transfer agentdidexcept,Example
Polymerization was carried out in the same manner as in Example 1, and after 6 hours, 92 g of white copolymer was obtained.
The body is in a slurry statesoGot.The copolymer concentration is 0.12
6g /mLMet. The copolymer is,270 ° C, heat
Decomposition start point 340 ° C, melt flow rate is 0,
300 ℃In the form ofIs extrusionIMoldingButProfitIsDid not. Comparative Example 2 In the same manner as in Example 1,Perform polymerization,14g after 2 hours
White copolymer in slurry statesoObtainedWas.Copolymer concentration
The degree is 0.02g /mLMet.TheThe copolymer is,Melting point 2
70 ° C, thermal decomposition starting point 320 ° C, melt flow rate
85.compressionMoldingGenuineTensile strength is 270kg / c
m^Two, Tensile elongation is 185%,compressionMolded products are brittle
It was. [0025] According to the present invention, the terminal of the polymer molecular chain
Is bound to chlorineETFEsButDo not generate.Also,
ETFE with excellent moldability, heat resistance, solvent resistance, and chemical resistance
KindEconomically efficientIn constructionWear.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-298810 (JP, A) JP-A-6-298809 (JP, A) JP-A-3-243607 (JP, A) JP-A-3-299 17106 (JP, A) JP-A-57-38808 (JP, A) Table ⁷ 7-504224 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08F 2/00-2 / 60 C08F 214/26

Claims (1)

(57) the presence of polymerization of in the polymerization medium of the Claims: 1. A chain transfer agent
By that ethylene be - a manufacturing method of a tetrafluoroethylene copolymer, 3 to 10 carbon atoms as a polymerization medium
Saturated hydrofluorocarbons (where, 1 ≦ hydrogen atoms ≦ fluorine atoms) using a main belt flow rate 1
And the amount of the chain transfer agent at the end of the polymerization so as to obtain an ethylene-tetrafluoroethylene copolymer of from 30 to 30.
Controls the concentration of the len-tetrafluoroethylene copolymer
A process for producing an ethylene-tetrafluoroethylene copolymer.