MXPA97005076A - Ethylene copolymers that contain fl - Google Patents

Abstract

Ethylene copolymers containing fluorine of the type ECTPE and ETFE, optionally in the presence of a third comonomer in an amount comprised between 0.1 and 10% in moles, having a viscosity between 10-2 and 10-6 Pa.sec with shear rates of 1 sec-1 measurements at a temperature of almost 30 ° C higher than the second melting temperature, and having a rheological curve in the shear viscosity / shear velocity plot with a slope greater than 200, calculated as the ratio between the viscosity in Pa.seg and the shear rate in sec-1 on the shear rate scale between 1 and 10 sec-1. and having a zone of processing capacity with shear velocity values greater than 10 s

Description

ETHYLENE COPOLIGIERQS CONTAINING FLUOR DESCRIPTIVE GOODS The present invention relates to fluorinated-containing e + full copolymers having a good processing capacity and alias mechanical properties. More particularly, the fluorine-containing copolymers are copolymers of the leno with TFE (t.et rat 1 uoroeti Leño) (ETFE) or copolymers of ethylene with CTFE (chlorot and fluoroethylene) (ECTFE). The trade name of ECTFE is Halar *. It is known that the modified or unmodified fluorine-containing copolymers of ECTFE (ethylene-chlorotri-luoroetheyl), and of modified ETFE (see the above-mentioned monomers), have good mechanical properties which nevertheless are decomposes dramatically with the decrease in the viscosity of the molten bath (low molecular weights). Unfortunately, the use of these products that have molecular weights higher than those used in the present, for pipes, pipes and cables, is not possible. due to the impossibility of processing them in the conventional machines used at present, as explained in detail below, it is known, said machines operate with a shear rate of 1 to 10000 sec-i of the molten bath, preferably For example, Halar products available in the market are of type 900, TO and 500, which differ in the viscosity of the molten bath (the says of the Flow of the Molten Bath (tFT)). The type 900 is characterized in that it has a very high molecular weight (MFI ba) and, therefore, good mechanical characteristics, however, it has the disadvantage that it can not be processed with shear rates greater than about 40. seg-i, and is usually used from 1 to 20 sec- * 1. Rdemas, if this speed of shear is exceeded, the manufactured article shows some rigidity and / or the molten bath shows phenomena of instability in the processing, which does not allow to obtain the manufactured article. Therefore, the productivity of these procedures is very low. Therefore, the shear rate scale is defined as the window area or the processing capacity of the rheological curve of the molten bath (shear viscosity / shear rate), where surface stiffness phenomena do not appear. and / or flow instability. In general, the viscosity measurement is carried out at temperatures of about 10 ° C-50 ° C higher than the second fume temperature of the copolymer. fidernás, if you want to prepare cables, it is not possible to obtain them with grade 900, since the cable lines operate at higher shear rates, usually greater than 100 sec-i. The available alternative was to use the 500 grade for the cables. Grade 500 has a very low viscosity compared to 900, and has a processing capacity window at re 100-500 sec-i. However, the mechanical properties are much lower with respect to the 900 degree, especially at high temperatures, where the cables do not show good mechanical properties. The grade 300 has an intermediate viscosity between 900 and 500; therefore, it has superior mechanical properties compared to 500; however, not yet enough to give a profile of optimal properties. 0 more than the processing capacity window is not yet wide enough, it can also be processed up to a maximum of 60 sec-i. Therefore, it can not be used for cables. Therefore, it would be desirable to have available a grade similar to 900 (good mechanical properties), but with a window of processing capacity in the area of type 500. There is no product on the market capable of meeting these requirements. On the other hand, if higher mechanical properties are desired than those of grade 900, this is not possible. This is due to the window of narrow processing capacity of the product, which would have a molecular weight higher than the 900 degree, reducing productivity, so it is necessary to change towards the lower limit of the scale of processing capacity where the machines work. An example of this application is to prepare pipes with very high performance, such as good mechanical resistance, even when subjected to thermal cycles at high temperature, and sheets in thermoformable processes. The Applicant has surprisingly found that it is possible to synthesize fluorine-containing ethylene copolymers with [-CTFF and F.TFE under these conditions to obtain products which have a good processability combined with excellent mechanical properties, especially at high temperatures, generally of 100 at 200 ° C, preferably from 140 to 180 ° C. The processing capacity of the copolymers of the invention is possible at shear rates greater than 100 seconds as the 500 degree, but with much greater mechanical properties, similar or even higher than the 900 degree. In particular, to obtain cables of Pulling, the copolymers of the invention having a molten bath viscosity of less than 10 * Pa.sec are used at shear rate of 1 sec-i, preferably greater than 102, measured at the temperature of 275 ° C. The viscosity measurement is generally carried out at temperatures of about 30 ° C-50 ° C higher than the second melting temperature of the copolymer. In the case of tubes and sheets, for example, the processing capacity of the copolymers is possible at shear rates of less than 60 sec-1 co or the 300 degree, but with mechanical properties clearly superior to the 900 degree. In particular, To obtain these Halar articles, the copolymers of the invention having a molten bath viscosity of less than 105 Pa.sec with shear rates of 1 sec-1, and preferably greater than 105, measured at the temperature of 275 ° C. The measurement of the viscosities is generally carried out at temperatures of about 30 ° -50 ° C higher than the second melting temperature of the copolymer. The copolymers of the invention, optionally in the presence of one or more co-workers, the total amount of which is comprised between 0.1 and 10 mole%, show a viscosity between 102 and 1 Pa.sec with effort velocities. cutting of 1 sec-1 measures at the temperature of almost 30"-5Q ° C higher than the second melting temperature, and show a rheological curve in the diagram of viscosity of shear stress versus shear velocity having a greater gradient- 200, calculated as a ratio between the viscosity in Pa.seg and the shear rate in sec-1 in the shear rate scale between 1 and 10 sec-1, said curve having a zone of processing capacity with shear velocity values greater than 10 sec-1, preferably greater than 50 sec-1 The copolymers of the invention generally exhibit a bi-oral molecular weight distribution, i.e. low molecular weight limicer having a viscosity comprised between 1 and 10 3 Pa.sec as above. Said low molecular weight fraction generally being between 5 and 60% by weight, preferably between 30 and 55% by weight; the remaining part having a higher molecular weight and being in amounts corresponding to the complement for 100% by weight. The distributions of high and low molecular weight can be more or less broad, and / or more or less narrow, which shows the contemporary presence of polymers that have different molecular weight, one with a low frequency of molecular weights and the other with a frequency of high molecular weights. In general, the measurement of the molecular weights of the polymers of the invention, as is known, is easily feasible due to the poor solubility of the fluorine-containing ethylene copolymers in solvents, for example, ethyl ketone (MEK), at room temperature. Therefore, gel permeation chromatography (GPC) to determine molecular weights can not be used. The flow curve, indicated above, of shear viscosity / shear rate, is measured in accordance with the patent fiSTM D3835. A method which can be used for the synthesis of the copolymers of the invention consists of modifying the processes for preparing Halar; see for example, MX 9705125A Batch: N98MA127 Date: 09/09/1998 Number of pages: 29 Previous document: MX 9705077A Next document: MX 9705149A COIL FOR MIXED LABELS Owner: Monarch Marking Systems, Inc. P.O. Box 608 Dayton, Ohio 45401 E.U.A.

Of North American nationality, Inventors: Thomas R. Loemker 50 Sunnie Hol and Drive Fairfield, CT 06430 E.U.A.

Paul H. Hamisch, Jr. 2653 Youngdale Drive Las Vegas, NV 89134 E.U.A.

Donald L. Karn 180 Pine Cone Tin Springboro, OH 45066 E.U.A.

Rudolph J. Klein 7213 Fawn Willow Court Centerville OH 45459 E.U.A.

All of North American nationality. from L to 6 carbon atoms; carbonates of b? s (alkyl), wherein the alkyl has from 1 to 5 carbon atoms; etc. Among them, chloroform and methylcyclopentane are particularly preferred. The total amount of the chain transfer agent used may vary within very wide limits, depending on the type of monomers used, the reaction temperature and the pressure. In general, said amount varies from 0.01 to 30% by weight, preferably from 0.05 to 10% by weight, with respect to the total amount of inonorneros introduced into the reactor. As modifying co-terminomers of the copolymers of the invention, there may be mentioned those well known in the art such as, for example, a fluorine-containing vinyl coronomer, such as a (per) fluoroalkylvinyl ether, wherein the alkyl has from 1 to 4 atoms of car-bond, in particular perfluoropropylvinyl ether, see the EUfl patent. USP-3,624,250. Possible alternative cornonary types of the above, having for example the formula R-CH = CH2, wherein R is a perfluoroalkyl or a perfluoroalkoxyperfluoroalkyl, are described in EP 185,241, EP 185,242, USP 3,847,881 and USP 4,513,129. The applicant has found that other modifying co -omers such as fluorodioxolee can also be used, see for example USP-3,865,845, EP-76,581, EP-80,187, EP-95,077 and EP-73,087; European patent application EP 720,991, in particular 2, 2, 4, -tri fluoro-5- tp f Luoi ometox? -1, 3-d? oxol (TTD). The copolymer of the present invention comprises: (a) from 30 to 70%, preferably from 40 to 60%, in moles of et al. (b) from 30 to 70%, preferably from 40 to 60%, in moles of a fluorine-containing mono-orne selected from tetrafluoroethylene, chloro-1-f-1-oleoethylene, or mixtures thereof; (c) from 0.1 to 10%, preferably < ie 0.3 to 5%, even more preferably from 0.5 to 5% by mole with respect to the total amount of monomers (a) and (b), of a modifying monomer as indicated above. The copolymers of the present invention can be prepared according to known techniques, by copolymerization of the corresponding monomers, in suspension in organic medium or in aqueous emulsion, in the presence of an appropriate radical initiator, at a temperature ranging from -60 ° and + 150 ° C, preferably between -20 ° and + 100 ° C. The reaction pressure is generally between 0.5 and 100 bar, preferably between 5 and 40 bar. Among the different radical initiators, in particular: (i) bis-acyl oxides of formula (Rf-C0-0) 2, where Rf is a (per) halogenoalkyl of Ci-Cio (cf. for example, patents EP-185,242 and USP-4, 513, 129), or a perfluoropolyoxyalkylamino group (see, for example, patents EP-186,215 and USP-5, 021, 516); among them, bis-trichloroacetyl peroxide and b-dichlorofluoroacetyl peroxide on a regular basis or re fe r t; (11) dialkyl per-oxides, of which diterbutyl peroxide (DTBP) is particularly preferred; (ni) water-soluble inorganic peroxides, such as ammonium or alkali metal persulfates or persulfates; ammonium or potassium per-sulfate is particularly preferred; (iv) dialkyl idicarbonates, wherein the alkyl has from 1 to 8 carbon atoms, such as, for example, dioxidi carbonate di-n-ropylo and peroxid carbonate di-isopropyl (see EP- 526,216); (v) organic or organic oxide-reduction systems, such as arnonium persulfate / sodium sulfate, hydrogen peroxide / arninoiminornetansulfinic acid, etc. In the case of polymerization of the suspension, the reaction medium It is formed by an organic phase, to which water is often added to favor the dispersion of heat that occurs during the reaction. The organic phase can be formed by the monomers themselves, without the addition of solvents, or by the workers dissolved in an appropriate organic solvent. As organic solvents, chlorofluorocarbons are conventionally used, such as: CC12F2 (CFC-12), CCI3F (CFC-11), CCI2FCCIF2 (CFC-113), CCIF2CCIF2 (CFC-114), etc. Since these products have a destructive effect on the ozone present in the stratosphere, alternative products have recently been proposed, such as the compounds containing only carbon, fluorine, hydrogen and optionally oxygen, described in patent USP-5,182,342. A valid alternative is branched chain hydrocarbons described in patent application EP 612,767, having from 6 to 25 carbon atoms and a ratio between methyl groups and carbon atom numbers greater than 0.5, such as eg 2, 3-d ? net 11 but ano, 2, 3 ~ d? rnet ligno, 2,2,4-tri ethylpentane, 2,2,4,6,6-pentamet? l heptane, 2,2,4,4,6-pent ametiiheptano, etc., or their mixtures. In the case of (co) polymerization in aqueous emulsion, the presence of an appropriate LVO surfactant is required. The most commonly used are surfactants containing fluorine having the formula: Rf -xr? + Where Rf in a (per) fluoroalkyl chain of C5-C16 or a (per) fluoropoiioxialqui lénica chain, X- is - C00- or O3-, N + is selected from: H +, NH4 +, an alkali metal ion. Among them are mentioned: perfluoro-octanoate or ammonium and / or sodium, (per) fluoropolyoxyalkylenes terminated with one or more carboxyl groups, etc. The object process of the present invention can be advantageously carried out in the presence of perfluoropolyoxyalkylene emulsions or emulsions, in accordance with US Pat. Nos. 4,789,717 and USP-4,864,006, or else fluoropolysiloxyalkylene icroernulsions having terminal groups containing hydrogen and / or repeating units containing hydrogen, optionally in admixture with a hydrocarbon, in accordance with European patent application EP 625,526 and EP 712,882 in the name of the applicant. Some useful examples of the present invention are reported below, the purpose of which is merely illustrative, but not limiting, of the scope of the invention.

EXAMPLE 1 In an 18-liter enameled autoclave equipped with a deflector and agitator running at 450 rpm in Hastel loy C, 4.3 liters of mineralized water, 1.7 1. (1.36 1-g) methyl alcohol, 685 g of perfluoropropyl alcohol were introduced. and 3 kg of chlorotrifluoroethylene. Afterwards, the temperature was brought to 5 ° C. Then the full feed was fed at a pressure of 1.1.35 bar. Absolute. In the autoclave, the radical initiator was then introduced, in the form of a solution, maintained at -17 ° C, of tpcloroacetyl peroxide (TCAP) in isooctane having a title reported in the table, with a flow rate of 7.5 cc / hour until an ethylene consumption of 125 g. At this conversion, 40 ml of chloroform were introduced and successively the flow rate of the initiator was increased to 60 cc / hour. The pressure was maintained constant throughout the polymerization time by continuously feeding and cycling in the reactor to a consumption of 250g. The other parameters of the reaction, the molten bath flow index (HFI) according to ASTM 3275-89, and the second melting temperature (Tm (II)) determined by differential scanning calorimetry (DSC) of the polymer obtained, are reported in the table. The mechanical properties at 175 ° C reported in the table were obtained in accordance with the OST DI 708 patent, using molded compression plates. The flow curve (shear viscosity / shear rate) of the polymer was obtained at 275 ° C in accordance with ASTM D3835 on the scale of 1-1000 s_1, from which the capacity window is obtained of processing and the slope determined between 1 and 10 sec-1 of constant effort velocity.

Obtaining the viscosity of the low molecular weight fraction 1. Obtaining the calibration curve Several products were pollenized by introducing different amounts of chloroform into the autoclave only at the beginning, in order to have different concentration ratios between chloroform (ml) and chlorotrifluoroethylene (kg). The operating conditions of the reactions (pressure and temperature) are those of the examples. These synthesized products were characterized from the theological point of view, evaluating in particular the viscosity of shear stress at the shear rate of 1 sec- (at 275 ° C). In this way, a viscosity-concentration ratio curve is obtained, so by regression the following formula is obtained for the viscosity n in Pa.sec: rnL of GHC13 (T) n (a 1 i) 24000 exp C -D •? w Kg of CTFE 2. Evaluation of the viscosity The evaluation of the viscosity of the low molecular weight fraction is obtained by calculating the concentration ratio between chlorotorrn and full chlorotri fluoroel remaining in the reaction at the time of the chloroform addition. For example, for the reaction of example 1, the r-shelf amount of CTFE is almost 2.2 kg, from the mass balance, thus introducing 40 ml of CHCI3 in the autoclave obtaining a proportion of 18.2 rnl / kg. Therefore, from the equation (I), a viscosity of 255 Pa.s. is obtained.

EXAMPLE 2 Tube extrusion test The polymer of example 1 was used, the amount necessary from which the extrusion was obtained by several polypeptides. The polymer was processed in an individual screw extruder having a diameter of 45 m with a die of internal diameter of 54.7 nm and an external diameter of 65.66 nm.

The operating conditions of the extrusion test are as follows: - Screw speed = 60 rprn Flow rate = 25 Kg / hour - Line speed - Ob rn / run - Temperature of the molten bath - 280 ° C In this way, a tube having a diameter of 50 rn with a thickness of 3.2 m was obtained. The tube has a smooth surface inside and outside, with mechanical properties practically equal to those described in example 1.

EXAMPLE 3 Example 1 was repeated, except that at the conversion of 125 g, 60 ml of chloroform was introduced.

EXAMPLE 4 In an enameled autoclave equipped with deflectors and agitator - running at 450 rprn in Hastelloy C, they were introduced 4. 3 liters of demineralized water, 1.7 liters of methyl alcohol, 300 g of? , 2, 4 -t p fluoro -5-t ri fluorornetox? -1, 3-d? Oxol (TTD) and 3 kg of. lorot r 1 uoroethylene. The autoclave was then brought to the reaction temperature of 5 ° C. Then ethylene is fed at a pressure of 11.35 bar. Absolute. In the autoclave, the initiator of the radical was then introduced, under the form of a solution, maintained at -17 ° C, of tpcloroacet peroxide (TCAP) in isooctane having the title reported in the table, with a flow rate of 7.5 cc / hour up to a consumption of otiieno of 175 g "At this conversion, 54 ml of chloroform were introduced and successively the flow rate of the initiator was increased up to 60 cc / hour. The pressure was maintained constant throughout the polymerization time, continuously feeding the leno into the reactor to a consumption of 250g. The other parameters of the reaction, the flow rate of the molten bath (MFT), the second melting temperature (Trn (ID), the mechanical properties at 175 ° C and the window of the polymer processing capacity, they report in the box.

EXAMPLE 5 (comparative) Example 4 was repeated, except that 5 rnl of chloroform were introduced after the addition of the methyl alcohol, while no amount of chloroform was added during the reaction and the flow rate of the radical initiator was always maintained at 7.5 cc / hour.

EXAMPLE 6 The polymer of Example 1 was processed in an individual screw extruder having a diameter of 45 nm equipped with a flat head to produce sheets. The operating conditions of the test are as follows: Screw speed: 35 rpm Line speed: 0.6 rn / rnin Melt bath temperature: 275 ° C Calendering temperature: 225 ° C Thus, a sheet having a thickness was obtained of 1 nm. EXAMPLE 7 The sheet of Example 6 was tempered at 170 * 0 and 185 ° C and at two forming speeds of 1 mm / min and 50 rn / rnin No fractures have been observed in any of the four cases.

EXAMPLE 8 The polymer of Example 1 was processed in an individual screw extruder having a diameter of 38 nm equipped with a die having an internal diameter of 2.1 nm and an outer diameter of 3.2 mm.

The operating conditions of the test are the following: Screw speed: 33 rprn Line speed: 160 m / rnin Temperature of the molten bath: 286 ° C A wire was obtained having the conductor (copper) of 0.8 mm diameter and thickness of the insulator 0.22 rn.

EXAMPLE 9 Example 1 was repeated, except that 0.5 rnl of chloroform had been fed after the addition of methyl alcohol.

TABLE 1 (1) Values evaluated with equation (I) for the low molecular weight fraction. (2) The product ext noise shows a slight roughness.

Claims (2)

1. NOVELTY OF THE INVENTION CLAIMS 1. - Ethylene copolymers containing fLuor of the ECTFE and ETFE type, optionally in the presence of one or more grades, the total amount of which is comprised in re 0.1 and 10% by weight, having a viscosity between 102 and LO5 Pa .. sec. on shear velocities of i sec- to the ternporature measured at about 30 ° -50 ° C higher than the second melting temperature, and having a rheological curve in the shear viscosity diagram / velocity of Shear stress having a slope greater than 200, calculated as a ratio between the viscosity in Pa.sec and the shear rate in sec-1 in the shear rate scale between 1 and 10 sec-1, said curve having a zone of processing capacity with shear velocity values greater than 10 s_.
2. 2. Copolymers of ethylene containing fluorine of the ECTFE and ETFE type, according to claim 1, wherein the copolymers show a molecular weight distribution of bimodal type, that is, they contain a polymerase fraction with ba or molecular weight having a viscosity comprised between 1 and 5,103 Pa.sec, said fraction of ba or molecular weight- being between 5 and 60% by weight, the r-shelf part having a higher molecular weight and being in "> ' cant Lenses that correspond to the complement to 100% by weight. 3.- Fluorine-containing ethylene copolymers of the ECTFE and FTFE type, according to claim 2, wherein the low molecular weight fraction is comprised in -30 and 55% by weight. 4"- Copolymers of ethylene containing fluorine of the ECTFE and ETFE type, according to claims 2 and 3, wherein the distributions of low and high molecular weight are more or less broad and / or more or less narrow, which show the contemporary presence of polymers that have different molecular weight, one frequently with low molecular weights and the other frequently with high molecular weights. 5. Use of ethylene copolymers containing fluorine of the ECTFE and ETFE type, according to claims 1 to 4, for preparing tubes, sheets and cables. 6. Use of ethylene copolymers containing fluorine of the type ECTFE and ETFE, according to claim 5, for the preparation of flexible tubes for the transport of petroleum to be used at high depths of the sea. 7. Useable procedure for the synthesis of the copolymers of claims 4, wherein the respective comonomers are polyperated by 40-95% by weight on the total polymer obtained, then adding the chain transfer agent to prepare -ar the low molecular weight fraction as defined above. 8. - Process for the synthesis of the copolymers according to claim 7, wherein in the preparation phase of the high molecular weights, a quantity of chain transfer agent is present, less than 20% by weight of the Total used in the preparation of the final copolymer "9.- Procedure for the synthesis of copolymers according to claim 8, wherein in the phase of preparation of high molecular weights, it is operated in the absence of transfer agents of chain, or in the presence of chain transfer agents in amount less than 1% by weight with respect to the total monorneros, preferably less than 0.2% by weight, for the preparation of the high molecular weight fraction. 10. Process for the synthesis of the copol irion according to claims 7 to 9, wherein the chain transfer agents are selected from: ketones, esters, ethers or aliphatic alcohols having from 3 to 10 carbon atoms. carbon; hydrocarbons or hydrocarbons containing halogen, having from 1 to 6 carbon atoms; bis (alkyl) carbonates in which the alkyl has from 1 to 5 carbon atoms. 11. Process for the synthesis of the copolymers according to claim 10, wherein the transfer agents are chloroform or ne-cyclopentane. 12. - Procedure for the synthesis of the codend! Utensuses according to claims 10 and 11, wherein the total amount of chain transfer agent used varies from 0.01 to 30% by weight with respect to the total number of millionaires. 13. Process for the synthesis of the copoL u eros in accordance with claim 12, wherein the total amount of the chain transfer agent used varies from 0.05 to 10% by weight. 14. Process for the synthesis of the copolyrners according to claims 7 to 13, wherein as one or more monomers selected from a fluorine-containing vinyl fluorine, coronorbents of formula are used as comonorders modifying the copolymers. R-CH-CH, wherein R is a perfluoroalkyl or a per-luoroalkoxyl-perfluoroalkyl, fluorod oxoles. 15. Process for the synthesis of the copol rans in accordance with claim 14, wherein the coinonornero modifier is selected from 2,2,4-tpfluoro-5-tr? Fluoro? Netox? -1, 3-d Oxol (TTD), (per) fluoroalkylvinyl ethers, wherein the alkyl has from 1 to 4 carbon atoms, in particular perfluoropropylvinyl ico ether. 16. Process for the synthesis of the copolymers according to claims 7 and 15, wherein the obtained human copol comprises: (a) from 30 to 70% by moles of ethylene; (b) from 30 to 70 mole% of a monomer that? r-, contains fluorine selected from tetra fl uoroethylene, cLorotr fluoroet i le or, or mixtures thereof; (c) from 0.1 to 10% in dollars with respect to the total number of merchants (a) and (b) of a modifying monomer of the preceding claims. 17. Process for the synthesis of copolymers according to claim 16, wherein the copolunor obtained comprises: (a) from 40 to 60 mol% of the full; (b) from 40 to 60% by mole of a nrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr Fluorine selected from tetrofluoroet i leño, cl orotp luoroet i leño, or mixtures thereof; (c) from 0.5 to 2.5 mole% with respect to the total amount of onorneros (a) and (b) of a monomer-or modifier of the preceding claims.