A pipe connector incorporates a main body, a first gripper and a second gripper; wherein the first gripper is installed on one end of the main body and the second gripper installed on the other end of the main body; and the first gripper and second gripper face different directions. The present invention can be used in conjunction with additional pipe connectors so as to increase the number of pipe combinations.

1. Field of the Invention
The present invention relates to a pipe connector which fixes two pipes in relative positions.
2. Description of Prior Arts
Generally in the designs of structures of housing, scaffolding, green house, fence, shelving, and stall, pipes are used to reserve a path for wiring or drainage purpose.
To adopt designs of various constructions, each pipe is usually converged and staggered at a certain area. To avoid pipes impacting each other or with other structure due to shaking and result in pipe ruptures, pipe connectors (or pipe fittings) such as the one shown in FIG. 2 are installed at the converging position. The pipe connector 90 of the prior art shown in FIG. 2 is a 2-way pipe connector that comprises two inserts 901 and 902. Place pipes P1 and P2 respectively into the inserts 901 and 902 of pipe connector 90 to secure the positions of two pipes. The interval between P1 and P2 is thus fixed and formed as preset in FIG. 1 to avoid impact.
However, the pipe connector 90 of the prior art is in standard specification and can not be used to combine other number of pipes. As shown in FIGS. 3 and 4, to fix three pipes P1, P2, and P3, the pipe connector used must be the kind of three-way pipe connector 91 that comprises at least three inserts 911, 912, and 913; the foresaid two-way pipe connector 90 can not be applied. From here we know that to secure the positions of different quantities of pipes, the pipe connectors used must be with corresponding quantities of inserts. Moreover, the more the number of pipes to be secured and connected, the wider the derived patterns. In other words, patterns of pipe connectors to be prepared are more diverse.
It is known from the above, it is necessary to prepare various corresponding type of pipe connectors to connect different quantities of pipes. The fact that the constructor must carry various types of pipe connectors to the working site is indeed causing trouble to constructor or who is in charge of material preparation, and indirectly affect construction schedule. In addition, in response to variety of needs, the manufacturers produce various types of pipe connectors, resulting in inventory increase and relatively increase the cost of pipe connectors.


A mounting apparatus for mounting a battery includes a base and a bracket. The bracket is configured for receiving the battery. The bracket is rotatably mounted to the base.

1. Technical Field
The present disclosure relates to mounting apparatuses and, more particularly, to a mounting apparatus for mounting a battery.
2. Description of Related Art
Generally speaking, a printed circuit board (PCB) of a computer system includes a battery holder fixed thereon for mounting a battery, such as a button cell battery to supply power for a basic input output system (BIOS) of the computer system after the computer system is shutdown. Therefore, the BIOS can keep time even though the computer system is shutdown.
Currently, battery holders maintain batteries fixedly to the PCB, either parallel or vertical, which limits options in the layout of the PCB.
What is desired, therefore, is an apparatus for mounting a battery which overcomes the above-mentioned shortcoming.


An improved level shifter circuit with AC feed-forward is disclosed. The integrated circuit device includes a first circuit part biased from a lower voltage supply and a second circuit part biased from a higher voltage supply. One of the circuit parts has an RS flip-flop with two complementary signal outputs and the other one has a signal input and a first and a second switching transistor. The first and the second switching transistors each have a current channel DC coupled in series with a respective cascode-connected transistor which is connected to a respective one of the signal outputs. One of these outputs is coupled to the input through a first feed-forward AC series circuit of an inverter and a first coupling capacitor, and the other output is coupled to the input through a second feed-forward AC circuit including a second coupling capacitor.

Integrated circuit (IC) devices with positive and negative supply, IC devices with separate circuit parts biased from first and second supplies, respectively, that have a common reference, or circuits with a supply voltage higher than a maximum permissible gate-to-source voltage of a MOS transistor within the device, typically need a signal level shifter circuit communicating an input signal received at an input of one of the first and second circuit parts to an output of the other circuit part. In the present disclosure, assuming the case of a first supply with a Ground terminal referred to as "GND" and a supply terminal referred to as VCC (a usual convention in IC circuits), and a second supply also with a Ground terminal "GND" and a supply terminal "VCC", the second supply being referenced to the GND terminal of the first supply and having a voltage level higher than the voltage level of the first supply, the lower supply has supply terminals referred to as GND_LOW and VCC_LOW, and the upper supply has supply terminals referred to as GND_UPP and VCC_UPP. In a configuration with positive and negative supplies that have a common GND terminal, similar designations would be used mutatis mutandis.
A signal level shifter should transfer a ground-referenced DC signal to a DC signal referenced to the VCC terminal, a VCC referenced DC signal to a Ground referenced DC signal, or a DC signal referenced to any terminal of a first supply to a DC signal referenced to any terminal of a second supply. Standard DC signal level shifters in integrated MOS, CMOS or BiCMOS circuits have a relatively high propagation delay, especially when cascode stages are needed for blocking excessive voltages between circuit parts or circuit components.

High-speed lever shifter with AC feed-forward


Apparatus according to the subject invention includes two independent acquisition systems, wherein one of the two independent acquisition systems acquires the acquisition clock of the other acquisition system along with a signal from a known acquisition reference point. In general, the first independent acquisition system is a logic analyzer, and the second independent acquisition system can be an ILA, a second logic analyzer, an oscilloscope, or other sampling device.

A logic analyzer is a test and measurement instrument that acquires data samples from a system under test (also known as a target system or simply a target) over a large number of channels. Logic analyzers typically store a timestamp with each acquisition sample that records the precise time at which that sample was acquired, relative to the beginning of the acquisition process. In typical logic analysis systems, such as the TLA family of Logic Analyzers, manufactured by Tektronix, Inc. of Beaverton, Oreg., the acquisition start signal and timestamp clock are distributed to all acquisition units in the system so that all units act in concert. Thus, when an acquisition is complete, it is possible to sort and display samples from all of the units in an ordered sequence based on the timestamp values stored with each sample. This process is known as Time Correlation.
However, in some instances, it is necessary to use multiple, independent, acquisition systems to acquire data simultaneously. Independent, in this case, means that the acquisition systems do not share both a common start signal and common timestamp clock. As such, the mechanism described above cannot be applied. Nevertheless, it is desirable to be able to present the data acquired by these independent systems in a time-correlated display.
One example of a pair of independent systems that suffer from this problem consists of a logic analyzer in concert with a Xilinx ILA (Integrated Logic Analyzer), manufactured by Xilinx, Inc. of San Jose, Calif. The Xilinx ILA gives users of Xilinx FPGAs (Field Programmable Gate Arrays) the ability to acquire data from internal FPGA nodes and to save that data in memory in the FPGA for later retrieval and display. The user defines a custom ILA for his/her specific application, specifying which nodes to acquire, which nodes to use for triggering, and clocking, and the acquisition buffer depth. The ILA definition is merged with the user's own FPGA source code, and is then programmed into the target component. The logic analyzer gives users visibility of logic signals external to the FPGA while the ILA provides visibility of FPGA internal nodes. It would be desirable for users to be able to view both sets of data in a time-correlated presentation such that relationships between internal and external activity could be analyzed. Yet, these two systems, the ILA and logic analyzer, use independent acquisition clocks and do not share a common start signal. Furthermore, the ILA does not save timestamp information with its samples at all.
Agilent Technologies, Inc. of Palo Alto, Calif., has developed an approach and a tool for time correlation, which enables data acquired by their 16700 series logic analyzer to be time correlated with data from a Xilinx ILA under limited circumstances. In this prior art solution, the ILA trigger signal is routed to one of the FPGA external pins, such that it can be acquired by the logic analyzer along with other external data. A transition on this signal provides a single reference point in the 16700 acquisition corresponding to a known sample in the ILA acquisition. In this prior art solution, the user must specify the period of the clock that is being used to acquire the ILA data It is then possible to calculate effective timestamps for the remaining ILA samples, relative to the known timestamp at the trigger point. This solution is explained in detail in an Agilent product note entitled, Using the Agilent Technologies 16700 Series Logic Analysis System with the Xilinx ChipScope ILA, published in November 2000.
This prior art approach enables the Agilent 16700 to effectively time correlate the data from the ILA with its own acquisition data, but is limited to systems in which the ILA acquisition clock has a regular, fixed and known period. It will not function properly if the acquisition clock is irregular or is qualified (temporarily inhibited) by other system logic. This solution also suffers from drift between the Agilent 16700 timestamp clock and the clock being used for ILA acquisition. The cumulative effect of this drift decreases the accuracy of derived timestamps for the ILA samples as the time interval between the known reference point and any given sample increases. What is needed is a solution that provides time correlation between two independent acquisition systems without requiring the use of a common timestamp clock nor an acquisition clock with a known, fixed, period.

Time correlation of data acquisition samples from independent systems in a logic analyzer


Disclosed herein are novel amorphous tetrafluoroethylene-hexafluoropropylene (TFE-HFP) dipolymers, and other copolymers containing TFE, HFP and a third monomer, many of which are more random than previous amorphous TFE-HFP copolymers, as well as a novel high productivity continuous process for making these polymers. The polymers are particularly useful in the form of coatings, films and encapsulants.

This invention concerns copolymers containing hexafluoropropylene and tetrafluoroethylene which are amorphous. They may be produced by a novel high pressure continuous process.
Amorphous fluorinated polymers, particularly perfluorinated polymers, are highly useful, particularly as coatings and encapsulants, because of their unusual surface properties, low refractive index, low dielectric constant., and the relative ease of coating or encapsulating objects with such polymers. However, the use of such polymers has been limited because of their high cost, which usually derives from the high cost of the monomers and/or the high cost of the polymerization process to make the polymers. Therefore, such polymers, and the processes for making them, which are lower in cost are constantly being sought.
U.S. Pat. No. 3,062,793 describes amorphous copolymers of tetrafluoroethylene (TFE) and hexafluoropropylene (HFP) which are made by a high pressure free radical polymerization. The only process described therein is a batch process which has a relatively low productivity.
This invention concerns a continuous polymerization process, comprising, contacting at a pressure of about 41 MPa to about 690 MPa, and a temperature above about 200xc2x0 C., preferably about 200xc2x0 C. to about 400xc2x0 C., tetrafluoroethylene, hexafluoropylene, and a radical initiator, to produce an amorphous polymer which contains at least 30 mole percent, of repeat units derived from said hexafluoro-propylene, at least 1 mole percent of repeat units derived from said tetrafluoro-ethylene, and provided that said continuous polymerization has an average residence time of about 5 seconds to about 30 minutes.
This invention also concerns an amorphous polymer, consisting essentially of repeat units of the formula:
(a) at least about 30 mole percent of
xe2x80x94CF2xe2x80x94CF(CF3)xe2x80x94xe2x80x83xe2x80x83(I)
(b) at least about 1 mole percent
xe2x80x94CF2xe2x80x94CF2xe2x80x94xe2x80x83xe2x80x83(II)
xe2x80x83and
(c) 0 to about 10 mole percent
wherein X is xe2x80x94CnF2n+1 or xe2x80x94OCnF2n+1, m is 2, 3 or 4, and n is either an integer of 2 to 20 with alkyl groups xe2x80x94CnF2n+1 or an integer of 1-20 with alkoxy groups xe2x80x94OCnF2n+1.
provided that in said polymer less than 20 mole percent of (I) is present in the form of triads.
The invention also concerns a continuous polymerization process, comprising, contacting at a pressure of about 41 MPa to about 690 MPa, and a temperature of about 200xc2x0 C. to about 400xc2x0 C., tetrafluoroethylene, hexafluoro-propylene, and a third monomer and a radical initiator, to produce an amorphous polymer which contains at least 15 mole percent, preferably 30 mole percent of repeat units derived from said hexafluoropropylene, at least 0-70 mole percent of repeat units derived from said tetrafluoroethylene, and 0-70 mole percent of repeat units derived from said third monomer, and provided that said continuous polymerization has an average residence time of about 5 seconds to about 30 minutes.
This invention also concerns a compound of the formula (C4F9)2NSCF3.
A novel compound herein is R6R7CFSO2R8 wherein R6 is perfluoroalkyl, perfluoroalkyl containing one or more ether oxygen atoms, perfluoroalkoxy or perfluoroalkoxy containing one or more ether oxygen atoms, R7 is perfluoroalkyl or perfluoroalkyl containing one or more ether oxygen atoms, and R8 is perfluoroalkyl. It is preferred that each of R6, R7 and R8 independently contain 1 to 30 carbon atoms. It is also preferred that R8 is perfluoro-n-alkyl containing 1 to 20 carbon atoms. It is more preferred that R6 is perfluoro-n-propoxy, R7 is trifluoromethyl, and R8 is perfluoro-n-octyl. This compound is useful as an initiator for the polymerizations described herein.
Also disclosed herein is an amorphous polymer containing repeat units derived from:
27-60 mole percent hexafluoropropylene, up to 35 mole percent total of one or more second monomers, and the balance tetrafluoroethylene, provided that at least one mole percent of TFE is present in the polymer, and wherein said second monomer is ethylene, vinyl fluoride, trifluoroethylene, 3,3,3-trifluoro-propene, 2,3,3,3-tetrafluoropropene, 4-bromo-3,3,4,4-tetrafluoro-1-butene, CH2xe2x95x90CHO(Cxe2x95x90O)R2 wherein R2 is perfluoro-n-alkyl containing 1 to 8 carbon atoms, CH2xe2x95x90CHR3 wherein R3 is perfluoro-n-alkyl containing 1 to 8 carbon atoms, CH2xe2x95x90CH(Cxe2x95x90O)OR4 wherein R4 is CnFxHy wherein x+y=2n+1 and n is 1 to 8, chlorotrifluoroethylene, or allyltrimethoxysilane;
27-60 mole percent hexafluoropropylene, up to 5 mole percent total of one or more fourth monomers and the balance tetrafluoroethylene, provided that the polymer contains at least 1 mole percent tetrafluoroethylene, wherein said fourth monomer is perfluorocyclopentene, perfluorocyclobutene, CF2xe2x95x90CFCF2CN, CF2xe2x95x90CFR5 wherein R5 is perfluoroalkyl optionally containing one or more of one or more ether groups, one cyano group, or one sulfonyl fluoride group, perfluoro-(2-metylene-4-methyl-1,3-dioxolane), perfluoro(2-methyl-2,3-dihydro-1,4-dioxin), or FSO2CF2CF2OCF(CF3)CF2OCFxe2x95x90CF2; or
up to 30 mole percent total of one or more second monomers and up to 5 mole percent total of one or more fourth monomers.
Described herein is an amorphous copolymer, consisting essentially of:
(a)  greater than 15 mole percent of the repeat unit
xe2x80x94CF(CF3)xe2x80x94CF2xe2x80x94xe2x80x83xe2x80x83(I)
(b) at least 1 to about 60 mole percent of the repeat unit
xe2x80x94CF2xe2x80x94CF2xe2x80x94xe2x80x83xe2x80x83(II)
(c) about 0.1 to about 85 mole percent of the repeat unit
xe2x80x94CH2xe2x80x94CF2xe2x80x94xe2x80x83xe2x80x83(IV)
wherein no more than about 20 mole percent of (I) is present in triads.
Also described herein is an amorphous copolymer, consisting essentially of repeat units of the formula:
(a)  greater than 15 mole percent of the repeat unit
xe2x80x94CF(CF3)xe2x80x94CF2xe2x80x94xe2x80x83xe2x80x83(I)
(c) about 0.1 to about 85 mole percent of the repeat unit
xe2x80x94CH2xe2x80x94CF2xe2x80x94xe2x80x83xe2x80x83(IV)
wherein no more than about 20 mole percent of (I) is present in triads.
Described herein is an amorphous copolymer, consisting essentially of:
(a)  greater than 10 mole percent of the repeat unit
xe2x80x94CF(CF3)xe2x80x94CF2xe2x80x94xe2x80x83xe2x80x83(I)
(b) up to about 32 mole percent of the repeat unit
xe2x80x94CF2xe2x80x94CF2xe2x80x94xe2x80x83xe2x80x83(II)
(c) about 53 to about 85 mole percent of the repeat unit
xe2x80x94CH2xe2x80x94CF2xe2x80x94xe2x80x83xe2x80x83(IV)
wherein the sequence
xe2x80x94(CH2CF2)xe2x80x94(CH2CF2)xe2x80x94(CF2CH2)xe2x80x94xe2x80x83xe2x80x83(S1)
is present in an amount according to an equation
mole percent S1xe2x89xa70.23(mole percent VF2 in polymer)xe2x88x9210.2.
The TFE/HFP copolymer made herein is amorphous. By an amorphous polymer is meant that the polymer has a heat of melting of less than 1 J/g when measured by Differential Scanning Calorimetry (DSC) at a heating rate of 10xc2x0 C./min, in the case of a TFE/HFP dipolymer. This is measured on a xe2x80x9cfirst heatxe2x80x9d, that is virgin polymer is heated to at least 300xc2x0 C. in the DSC (at 10xc2x0 C./min), and the heat of melting, if any, is measured. In the case of terpolymers, where the residual third monomer is often removed from the polymer by heating for about four hours, at 150xc2x0 C., in a vacuum oven, DSC xe2x80x9csecond heatsxe2x80x9d, at 10xc2x0 C./min to at least 200xc2x0 C., were used.
These polymers are made via a continuous polymerization process in which the initial ingredients are fed to the reactor in an essentially continuous manner and in which the product stream is essentially continuously withdrawn at approximately the same rate at which the ingredients are added. Such types of reactions are generally known to the artisan, see for instance H. F. Mark, et al., Ed., Kirk-Othmer Encyclopedia of Chemical Technology, 3rd Ed., vol. 19, John Wiley and Sons, New York, 1982, p. 880-914. Such continuous reactors include continuous stirred tank reactors and pipeline (tubular) reactors. Under the conditions employed in the process as described herein, the productivity of the process is exceptionally high. By productivity herein is meant the weight of polymer produced in a unit volume of reactor in a unit volume of time. Productivities herein are reported as kg/L/hr.
The process described herein has typical productivities of about 0.8 to about 15 kg/L/hr. The Examples illustrate that typically higher polymerization temperatures give higher productivities. By contrast, a batch polymerization, making a somewhat similar polymer, reported in U.S. Pat. No. 3,062,793, has productivities (from the Examples) of about 0.01 to about 0.03 kg/L/hr, more than an order of magnitude less than that for the continuous process. This means a lower cost for polymer produced by the continuous process.
The process is run at a pressure of about 41 to about 690 MPa (xcx9c6,000 to xcx9c100,000 psi), preferably about 55 to about 172 MPa (xcx9c8,000 to xcx9c25,000 psi), more preferably about 62 to about 152 MPa (xcx9c9,000 to about 22,000 psi), and especially preferably about 69 to about 103 MPa (xcx9c10,000 to xcx9c15,000 psi). As pressure drops down towards 41 MPa the molecular weight of the polymers formed and the conversion of monomers to polymer both tend to drop.
It is preferred that solvents not be used in the process, since at these pressures the monomers, particularly HFP, usually dissolve the polymer. Nonetheless, solvents can be used in the reactor. If the final product is to be a polymer solution, making the polymer solution directly may be preferable, to reduce costs (see Example 43). Sometimes for convenience in handling, small quantities of initiator are best introduced when diluted to a larger volume with a small amount of solvent (see Example 51). Solvent may also be used for other reasons, such as to decrease the viscosity of the process mixture, or to help keep lines clear of polymer, particularly at lower pressures. When solvents are used it is preferred that they be essentially inert under process conditions. Useful solvents include perfluorodimethylcyclobutane and perfluoro(n-butyltetrahydrofuran).
The polymer is soluble in the monomer(s) under the process conditions. Therefore, one method of polymer isolation is to reduce the pressure below that required for solution of the polymer, and isolate the polymer from that, as by decantation, filtration or centrifugation. Indeed, it may not be necessary to reduce the pressure of the unreacted monomers to atmospheric pressure, but merely that required for phase separation of the polymer. Therefore these monomers can be recycled with only a xe2x80x9cpartialxe2x80x9d repressurization, thereby saving energy costs. Alternatively the pressure can be reduced to atmospheric pressure, while the volatile monomers are vented off, leaving the product polymer. The monomers can of course be recovered and reused.
The apparatus for running the polymerization may be any suitable pressure apparatus in which the reactant and products streams may be added and removed at appropriate rates. Thus the apparatus may be a stirred or unstirred autoclave, a pipeline type reactor, or other suitable apparatus. Agitation is not necessary, but preferable, especially to obtain polymers with low MWD""s. The material of construction should be suitable for the process ingredients, and metals such as stainless steel are often suitable.
The polymerization is carried out above about 200xc2x0 C., preferably from about 200 to about 400xc2x0 C., more preferably from about 225 to about 400xc2x0 C., and most preferably from about 250 to about 400xc2x0 C. The initiator is chosen so that it will generate active free radicals at the temperature at which the polymerization is carried out. Such free radical sources, particularly those suitable for hydrocarbon vinyl monomers at much lower temperatures, are known to the artisan, see for instance J. Brandrup, et al., Ed., Polymer Handbook, 3rd Ed., John Wiley and Sons, New York, 1989, p. II/1 to II/65. The preferred temperature for running our process depends on both the monomers and the initiator and is often a compromise between raising temperature to favor high productivities and high conversions and lowering temperature to minimize chain transfer and monomer degradation. For the copolymerization of HFP with TFE, for example, where chain transfer is not a problem, C2F5SO2C2F5 initiation is a good choice on account of the very high productivities it affords at 400xc2x0 C. For the polymerization of HFP/TFE/PMVE, however, where PMVE chain transfer is of prime concern, NF3 which retains good efficiency at 250xc2x0 C., is an excellent choice for initiator.
Suitable free radical initiators include NF3, RfNF2, Rf2NF, Rf3N, R1Nxe2x95x90NR1, RfOORf, perfluoropiperazine, and hindered perfluorocarbons of the formula CnF2n+2 such as are described in World Patent Application 88/08007, wherein each Rf is independently perfluoroalkyl, preferably containing 1 to 20 carbon atoms, hindered perfluoroalkenes of the formula CnF2n, perfluoro-(dialkylsulfones) of the formula R1SO2R1, perfluoroalkyl iodides of the formula R1I, R1SO2F, R1SO2Cl, ClSO2Cl, perfluoroalkylene diiodides of the formula IR6I where the two iodides are not vicinal or geminal wherein R6 is perfluoroalkylene containing 3 to 20 carbon atoms, perfluoro(dialkyldisulfides) R1SSR1, and perfluoroalkyl compounds containing nitrogen-sulfur bonds of the formula R12NSR1, wherein each R1 is independently saturated perfluorohydrocarbyl optionally containing one or more ether groups, isolated iodine, bromine or chlorine substituents, or perfluoroamino groups. By xe2x80x9csaturated perfluorohydrocarbylxe2x80x9d is meant a univalent radical containing only carbon and fluorine and no unsaturated carbon-carbon bonds. By an xe2x80x9cisolatedxe2x80x9d iodine, bromine or chlorine substituent is meant that there are no other iodine, chlorine of bromine atoms on carbon atoms alpha or beta to the carbon atom bonded to the isolated iodine, bromine or chlorine atom. All of these initiators are illustrated in one or more of the Examples. Some of these initiators may only be active at the higher end of the temperature range of the polymerization process. This too is illustrated in the Examples, and the activity of any particular initiator molecule may be readily determined by minimal experimentation. Preferred initiators are NF3 Rf2NF, RfNF2, perfluoropiperazine, perfluoro(dialkylsulfones), i.e. R1SO2R1, and hindered perfluorocarbons. NF3 is an especially preferred initiator. If higher molecular weight polymers are desired, the initiator should preferably not have any groups present in its structure that cause any substantial chain transfer or termination during the polymerization. Such groups usually include, for instance, organic bromides or iodides or carbon-hydrogen bonds.
The amount of free radical initiator used will vary depending on process conditions. Generally speaking an effective amount is used, an effective amount being that which causes more polymerization to take place with the initiator than without. It is likely that any polymerization without deliberately added initiator present is due to adventitious impurities which can act as initiators at the high polymerization temperatures. Effort should be made to minimize these impurities, such as oxygen. A useful range of initiator concentration has been found to be about 0.003 to about 0.5 g of initiator/kg monomer, preferably about 0.1 to about 0.3 g/kg. Higher or lower amounts are also useful depending upon the initiator, the monomers, goal molecular weights, process equipment, and process conditions used, and can readily be determined by experimentation. The initiator may be added to the reactor as a solution in the monomer(s).
While xe2x80x9csolventsxe2x80x9d may be added to the polymerization so that the polymerization is carried out in solution or slurry, it is preferred if little or no solvent is added. The polymer formed is often soluble in the supercritical HFP under the process conditions. The polymer may be isolated simply by reducing the pressure below about 34 MPa (xcx9c5,000 psi), at which point the polymer becomes insoluble. The polymer may also be isolated as fibers or fibrils by flash spinning from solvent and by direct flash spinning of the polymerization mixture. Small amounts of solvents may be used for convenience, as for a carrier for the initiator. FC-75, perfluoro(2-n-butyltetrahydrofuran), and the cyclic dimer of HFP are examples of useful solvents. Another useful solvent is supercritical CO2.
The polymer produced by the instant process is amorphous. Whether this type of a polymer would be amorphous depends on the composition (relative amounts of HFP and TFE and other monomers if present), and the distribution of the two repeat units in the polymer. If a dipolymer, the polymer product should preferably contain at least about 30 mole percent of (I) and at least 1 mole percent of (II), preferably at least 30 mole percent of (II), more preferably about 35 to about 50 mole percent of (I) and about 50 to about 65 mole percent of (II) when a dipolymer is made [no repeat unit (III) present]. Optionally up to about 10 mole percent of repeat unit (III) may be present. When (III) is present a preferred composition is about 35 to about 65 mole percent (I), about 35 to about 65 mole percent (II), and about 0.1 to about 10 mole percent of (III). Various comonomers (III) may be used in the polymerization process, and be incorporated into the polymer. Perfluoro(alkyl vinyl ethers) and perfluorinated terminal alkenes, each optionally substituted with ether, cyano, halo (other than fluorine), sulfonyl halide, hydrogen or ester groups may be used. Also unfluorinated or partially fluorinated olefins or vinyl ethers, optionally substituted as above, may also be used. Useful comonomers include CF2xe2x95x90CFOCF2CF(CF3)OCF2CF2SO2F, ethylene, propylene, isobutylene, vinylidene fluoride, vinyl fluoride, trifluoroethylene, 3,3,3-trifluoropropene, 2,3,3,3-tetrafluoropropene, 4-bromo-3,3,4,4-tetrafluoro-1-butene, perfluoro(8-cyano-5-methyl-3,6-dioxa-1-octene), CF2xe2x95x90CF(CF3)COF, CH2xe2x95x90CHO(C=O)R2 wherein R2 is perfluoro-n-alkyl containing 1 to 8 carbon atoms, CH2xe2x95x90CHR3 wherein R3 is perfluoro-n-alkyl containing 1 to 8 carbon atoms, CH2xe2x95x90CH(Cxe2x95x90O)R4 wherein R4 is CnFxHy wherein x+y=2n+1 and n is 1 to 8, allyltrimethoxysilane, perfluorocyclopentene, perfluorocyclobutene, CF2xe2x95x90CFCF2CN, CF2xe2x95x90CFR5 wherein R5 is perfluoroalkyl optionally containing one or more of one or more ether groups, cyano groups, and/or sulfonyl fluoride groups and preferably only one cyano or sulfonyl fluoride is present, perfluoro(2-methylene-4-methyl-1,3-dioxolane), perfluoro(2-methyl-2,3-dihydro-1,4-dioxin), FSO2CF2CF2OCF(CF3)CF2OCFxe2x95x90CF2, methyl vinyl ether, CFClxe2x95x90CF2, CH2xe2x95x90CFCF3, CH2xe2x95x90CHCF3, CH2xe2x95x90CHCF2CF2CF2CF3, CH2xe2x95x90CHCF2CF2Br, CF2xe2x95x90CFCF2CN, and CF2xe2x95x90CFCF2OCF2CF2SO2F. In preferred compounds R2 is trifluoromethyl, R3 is trifluoromethyl or perfluoro-n-butyl, R4 is 1,1,1,3,3,3-hexafluoroisopropyl, and R5 is xe2x80x94CF2CN.
The above monomers (and others) can be used to make copolymers containing repeat units derived from HFP, TFE and one or more of the above monomers of the following compositions, and in these compositions:
 greater than 30 mole percent HFP, up to 25 mole percent X with the balance TFE, provided the polymer contains at least 1 mole percent TFE, wherein X is ethylene propylene, isobutylene, or methyl vinyl ether;
 greater than 15 mole percent HFP, 0.1 to 85 mole percent vinylidene fluoride, and up to 60 mole percent TFE (note that this polymer may also be a dipolymer of HFP and vinylidene fluoride), preferably  greater than 20 mole percent HFP, 0.1 to 75 mole percent vinylidene fluoride and up to 60 mole percent TFE, and more preferably  greater than 30 mole percent HFP, 0.1 to 65 mole percent vinylidene fluoride and up to 60 mole percent TFE;
 greater than 30 mole percent HFP, up to 2 mole percent CF2xe2x95x90CF(CF3)COF, with the balance TFE, provided the polymer contains at least 1 mole percent TFE;
27-60 mole percent HFP, up to 35 mole percent X, and the balance TFE provided that at least one mole percent of TFE is present in the polymer, wherein X is vinyl fluoride, trifluoroethylene, 3,3,3-trifluoropropene, ethylene 2,3,3,3-tetrafluoropropene, 4-bromo-3,3,4,4-tetrafluoro-1-butene, CH2xe2x95x90CHO(Cxe2x95x90O)R2 wherein R2 is perfluoro-n-alkyl containing 1 to 8 carbon atoms, CH2xe2x95x90CHR3 wherein R3 is perfluoro-n-alkyl containing 1 to 8 carbon atoms, CH2xe2x95x90CH(Cxe2x95x90O)OR4 wherein R4 is CnFxHy wherein x+y=2n+1 and n is 1 to 8, chlorotrifluoroethylene, and allyltrimethoxysilane, and preferred polymers contain 30-50 mole percent HFP, up to 20 mole percent X and the balance TFE, and more preferred polymer contain 30-45 mole percent HFP, up to 10 mole percent X and the balance TFE.
27-60 mole percent HFP, up to 5 mole percent X and the balance TFE provided that the polymer contains at least 1 mole percent TFE, wherein X is perfluorocyclopentene, perfluorocyclobutene, CF2xe2x95x90CFCF2CN, CF2xe2x95x90CFR5 wherein R5 is perfluoroalkyl optionally containing one or more of one or more ether groups, one cyano group, or one sulfonyl fluoride group, perfluoro(2-metylene-4-methyl-1,3-dioxolane), perfluoro(2-methyl-2,3-dihydro-1,4-dioxin), or FSO2CF2CF2OCF(CF3)CF2OCFxe2x95x90CF2, and preferred polymers contain 30-50 mole percent HFP, up to 2 mole percent X and the balance TFE.
In all polymers which contain a monomer other than HFP, TFE and vinylidene fluoride, it is preferred that minimum level of additional monomer is 0.05, more preferably 0.1 mole percent. Also more than one monomer xe2x80x9cXxe2x80x9d may be present in any of the above polymers. When the xe2x80x9climitationxe2x80x9d on any particular monomer or monomers xe2x80x9cXxe2x80x9d is a given percentage, the polymer may contain up to that percentage (total) of that xe2x80x9ctypexe2x80x9d of monomer in the polymer. For example a copolymer may contain up to 35 mole percent combined of trifluoroethylene and 3,3,3-trifluoropropene, or another polymer may contain up to 5 mole percent CF2xe2x95x90CFCF2CN and up to 30 mole percent 3,3,3-trifluoropropene. The total amount of xe2x80x9cXxe2x80x9d which may be in the copolymer may not exceed the highest amount for any of the individual monomers, as given above.
Polymer containing HFP, vinylidene fluoride (VF2) and optionally TFE may be analyzed by 19F NMR to determine the microstructure of the polymer. In particular, the microstructure of monomer sequences of isolated repeat units derived from HFP and xe2x80x9csurroundedxe2x80x9d by monomer units derived from VF2 may be determined. These are:
Herein the above sequences will be referred to by their Sequence No. For determining these sequences, 19F NMR spectra were acquired on 5% solutions in hexafluorobenzene (HFB). Spectra were taken at 80 C on a Bruker AC 250 operating at 235.4 MHz for 19F. The acquisition conditions included a 90 degree pulse width of 5.0 xcexcsec, 20 second recycle delay, and 64 co-added scans. Spectra were referenced to HFB at xe2x88x92162.46 ppm.
Composition was determined from the 19F NMR spectrum in the following way. Because of the high concentration of HFP, it was assumed that all VF2 next to HFP was represented by the signal at xe2x88x9275 ppm. VF2 which was non-adjacent to HFP was taken from the signal at xe2x88x9282 ppm. The sum of these areas was converted to moles of VF2. The amount of HFP was determined from the sum of the areas at xe2x88x9275 ppm and xe2x88x9270 ppm, converted into moles of HFP. In samples containing TFE, the TFE was determined from the area of the signals between xe2x88x9295 and xe2x88x92125 ppm corrected for CF2s from HFP and corrected for the CF2s from VF2 represented in the signal of HFP CF3s adjacent to CH2s from VF2 adjacent to CH2s from VF2.
For at least one sample, the composition of VF2 determined in this manner was confirmed by adding an internal standard of trifluoromethyldichlorobenzene to a weighed amount of polymer and determining the amount of CF2 from the 1H spectrum. For the sample tested, the results agreed within 3% relative.
HFP centered sequences were used as a way to identify differences in polymerization. The 19F signal at xe2x88x92179 to xe2x88x92179.5 ppm was identified as the CF in an HFP centered VF2/HFP/NVF2 sequence in which the CH2""s are beta to the CF. The signal at xe2x88x92180.4 to xe2x88x92181.2 ppm was identified as a CF in a VF2/HFP/VF2 sequence in which there were one CH2 alpha and one CH2 beta to the CF in the HFP. The final signal at xe2x88x92181 to xe2x88x92181.8 ppm was identified as VF2/HFP/NVF2 in which one CH2 is alpha and one CH2 is gamma and one CF3 is delta to the CF.
Amorphous polymer containing HFP, VF2, and optionally TFE or other monomers, but preferably only TFE, may also be analyzed by 13C NMR. These analyses may yield additional information about these polymers. In particular, VF2 centered sequences may be determined, see for instance F. A. Bovey, et al., Macromolecules, vol. 10, p. 559 et seq. (1977), and R. E. Cais, et al., Analytica Chimica Acta, vol. 189, p. 101 et seq. (1986), both of which are hereby included by reference. In particular the sequence
xe2x80x94(CH2CF2)xe2x80x94(CH2CF2)xe2x80x94(CF2CH2)xe2x80x94xe2x80x83xe2x80x83(S1)
may be detected by its signal at 42.5 ppm (vs. hexafluorobenzene internal standard, see below for 13C NMR procedure). Any of the repeat units in the polymers, including VF2 units, may be bonded to the end of this sequence. It has been found (see Examples 133 to 136, and their 13C analyses) that polymers containing 53 or more mole percent of VF2, preferably about 58 or more mole percent VF2, and about 10 or more mole percent HFP, preferably about 15 or more mole percent HFP, and optionally containing TFE, made using the high pressure/high temperature polymerization processes described herein have a higher amount of this sequence than similar polymers made by xe2x80x9cconventionalxe2x80x9d methods.
The mole percent of VF2 in S1 in the polymer, based on the total amount of VF2 in the polymer (from the 13C analysis) is represented by the equation
mole percent S1xe2x89xa70.23(mole percent VF2 in polymer)xe2x88x9210.2
More preferably, the mole percent of S1 is
mole percent S1xe2x89xa70.23(mole percent VF2 in polymer)xe2x88x929.8
All of the polymers herein may be crosslinked by methods known in the art. Perfluorinated polymers may be crosslinked by exposure to ionizing radiation. Polymers containing hydrogen or functional groups such as nitrile or sulfonyl halide may be crosslinked by methods known in the art. When crosslinked these polymers are of course crosslinked elastomers if their Tg is below ambient temperature.
As mentioned above, the properties of the polymer will be affected not only by the overall composition of the polymer, but by the distribution of the various monomer units in the polymer. The instant process yields a polymer in which the monomer units are more uniformly distributed in the polymer, which gives polymer with more consistent properties. One measure of polymer uniformity is randomness of the monomer units in the polymer. A measure of this is relative amounts of isolated repeat units, diads, triads etc. By diads and triads are meant instances in which two or three repeat units from the same monomer, respectively, occur in the polymer.
Many of the polymers (including some of the polymers containing 3 or more different repeat units) made by the process described herein have relatively small amounts of triads of repeat unit (I), which of course derived from HFP. Thus in such polymers less than 20 mole percent of (I) is in the form of triads, and preferably less than about 15% and more preferably less than about 10%. As would be expected, in polymers with higher amounts of (I), there is a tendency towards higher triad content. The amount of triads in the polymer can be determined by 19F NMR (see below for procedure). See the summary of triad data for polymers prepared in Examples 23 and 33-36 in the table following Examples 45 to 49. See Examples 23 and 33-36 and Comparative Example 1 for triad amounts in various polymers.
The instant polymers also have a narrower molecular weight distribution (MWD) than prior art polymers. By MWD is meant the weight average molecular weight divided by the number average molecular weight (Mw/Mn). Polymers described herein often have MWD""s of less than 5, preferably less than 4. Such polymers often have a better combination of processability and physical properties.
Repeat unit (III) may be present to help suppress crystallization and/or lower a glass transition temperature, or for other purposes, and are derived from the corresponding xcex1-perfluoroolefin, perfluorocycloolefin or perfluoro(alkyl vinyl ether). Preferred monomers for unit (III) in which xe2x80x94CnF2n+1 is present are those in which CnF2n+1 is perfluoro-n-alkyl. When X is xe2x80x94CnF2n+1 it is preferred if n is 2 to 14, while if X is xe2x80x94OCnF2n+1 it is preferred if n is 1 to 4, more preferably 1 or 3.
Since TFE is considerably more reactive in the polymerization than HFP, an excess of HFP is needed to achieve the desired polymer composition. Typically this also means that at the end of the polymerization, much or all of the TFE will have polymerized, but there will be (a considerable amount of) unpolymerized HFP. In a sense this is an advantage, since the HFP can act to help carry the polymer from the reactor, and no additional carrier (such as a solvent) is needed. Typically the TFE will be about 1 to 15 mole percent of the total amount of monomer being fed to the process, with the HFP and other monomer(s) (if present) being the remainder.
The average residence time is the average amount of time any of the material fed to the reactor actually spends in the reactor, and is a function of the volume of the reactor and the volumetric flow of the process ingredients through the reactor. A preferred residence time is about 20 sec to about 10 min, more preferably about 30 sec to about 5 min, especially preferably about 40 sec to about 2 min. A minimum preferred residence time is about 10 sec., more preferably about 15 sec. A maximum preferred residence time is 10 min.
When the process fluids are being added to the reactor, it is preferred if they are preheated just before they enter the reaction to a temperature somewhat less than that of the actual reactor temperature, about 20xc2x0 C. to about 100xc2x0 C. less. This allows one to maintain a uniform constant temperature in the reactor itself, and for the newly added materials to start the polymerization reaction immediately upon entry to the reactor.
The amorphous polymers described herein are useful in a variety applications, many of which are related to the fact that the polymers are readily soluble in certain halogenated, especially perfluorinated solvents, and so the polymers are readily useable as films, coatings and encapsulants. Useful solvents include xe2x80x9cdimerxe2x80x9d, perfluorobenzene, perfluoro(n-butyltetrahydrofuran), and FC-10 (tradename of xe2x80x9cdimerxe2x80x9d 3M fluorocarbon fluid). Another type of useful solvent is a perfluorinated (organic) compound containing sulfur, such as perfluoro-1,4-dithiane, perfluorothiepane, perfluorodiethylsulfone, and perfluorooctanesulfonyl fluoride.
In one preferred form, the solvent used to form solutions of the amorphous polymers herein is a mixed solvent. By a mixed solvent is meant a solvent that contains two or more liquid compounds that are miscible with each other in the proportion used. The compounds in the mixed solvent need not be solvents for the amorphous polymer if used alone, but it is preferred that at least one of the compounds of the mixed solvent is a solvent for the amorphous polymer. It is preferred that one of the compounds of the mixed solvent be a perfluorinated compound, as described in the preceding paragraph. Another preferred compound is a hydrofluorocarbon or hydrochlorofluorocarbon as described in Example 128. A preferred procedure for forming a solution of the amorphous polymer in a mixed solvent is to dissolve the amorphous polymer in a perfluorinated compound, and then add the other compound(s).
Since the polymers are relatively chemically resistant, they may be used to encapsulate articles which must be protected from contamination, corrosion and/or unwanted adhesion to other materials. Films and coatings may be particularly useful because of the inherent properties of the polymer, such as, lack of crystallinity (polymer is clear), low surface energy (and hence poor wetting by water or most organic liquids), low dielectric constant, low index of refraction, low coefficient of friction, low adhesion to other materials, etc.
The TFE/HFP copolymers (including di- and terpolymers) of this invention can be used in many ways. One use is as a processing aid in polyolefins. This aspect of the invention is discussed in detail below.
The TFE/HFP and TFE/HFP/(III) copolymer solutions and copolymer/solvent systems of this invention can be used in many ways, making it possible to achieve end results that could not be achieved with previously available perfluoropolymers or could be achieved only in less convenient ways. These results include any of the results for which polymer solutions are used, such as coating, encapsulation, impregnation, and the casting of film. The copolymer solutions and copolymer/solvent systems of the invention can be employed in any of the methods by which solutions are known to be used, including dipping, painting, and spraying.
The copolymer solutions and copolymer/solvent systems of this invention can be used to make coatings on a broad range of substrate materials, including metal, semiconductor, glass, carbon or graphite, and natural and synthetic polymers. The substrates can be in a broad range of physical forms, including film or paper, foil, sheet, slab, coupon, wafer, wire, fiber, filament, cylinder, sphere, and other geometrical shapes, as well as in a virtually unlimited number of irregular shapes. Coatings can be applied by methods known in the art, including dipping, spraying, and painting. For plane substrates of suitable dimensions, spin coating can be employed. Porous substrates can also be coated or impregnated. These include, for example, screens, foams, microporous membranes, and woven and non-woven fabrics. In making such coatings, the solvent can be driven off by heat leaving a dry copolymer coating. Another advantage is that extremely thin coatings can be achieved, as thin as 100 angstroms or possibly even thinner depending on the coating characteristics required.
Coatings of the copolymers of this invention can be a sole coating on a substrate, or a component of a multilayer coating. For example, a TFE/HFP copolymer coating of this invention can be used as a first or primer, intermediate, or final coating in a multilayer fluoropolymer coating system. The coatings of this invention include coatings resulting from several successive applications of solution or copolymer/solvent systems to increase coating thickness to desired levels.
Coatings of this invention can consist of the copolymers of this invention alone, or of the copolymers admixed with minor amounts of other materials either soluble in the solvent or dispersed in the coating solution, suspension, or copolymer/solvent system. A minor amount can be up to about 10 wt % based on the combined weight of copolymer and additive.
Specific coated articles are within the scope of this invention.
Coated articles include polymer extrusion dies and molds for rubber and plastic parts, such as o-rings, bottle caps, golf balls, golf ball covers, golf ball cover half shells, and the like. The copolymers of this invention can be used in coatings. Both interior and exterior surfaces of extrusion dies may be coated to, respectively, facilitate extrusion and alleviate die drip buildup.
Coated articles include gasoline engine carburetor parts; internal parts of internal combustion engines such as valves and piston skirts; razor blades; metal containers such as cans, pans, trays, vessels, and the like; metal sheets and foils; continuous metal belts, metal rods, tubes, bars, profiles, and the like; bolts, nuts, screws, and other fasteners.
Coated articles include an article bearing a machine-readable marking on at least one surface, especially but not limited to a tag that can be attached to another object to provide information about inventory identification, contents, ownership, hazards, operating conditions, or maintenance requirements, for example.
Coated articles include wire for electrical and mechanical service. In either case, the metal wire may be solid or stranded. Wires for mechanical service include catheter guide wire and the actuating wire of push-pull cable.
Coated articles include rubber o-rings, seals, beading, gasketing, fish hooks, and the like.
Coated articles include paper and textile materials, including woven fabric including glass fabric, non-woven fabric, felts, and the like, fibers including filaments, yarns, e.g., staple and continuous filament, and strands.
Coated articles include foams, membranes, and the like.
Coated articles include optical fibers in which the substrate is a glass or plastic fiber.
Coated articles include semiconductors, semiconductor devices, magnetic storage media including disks, photoconductors, electronic assemblies, and the like, wherein the coating thickness may be as little as 200 angstroms or even as little as 100 angstroms or even as little as 50 angstroms. Use of solutions containing low concentrations of the TFE/HFP copolymer of this invention, e.g., as low as 0.001 wt % copolymer can be especially advantageous to form these very thin coatings.
One use for the TFE/HFP copolymers of this invention is as a processing aid in polyolefins. When the TFE/HFP copolymer of this invention is used as a processing aid in the polyolefin for film applications, the polyolefin generally will have a melt index (ASTM D-1238) of 5.0 or less at 190xc2x0 C., preferably 2.0 or less. For high-shear melt processing such as fiber extrusion or injection molding, even high-melt-index resins, for example, those having a melt index of 20 or more, may suffer processing difficulties. Such polyolefins may comprise any thermoplastic hydrocarbon polymer obtained by the homopolymerization or copolymerization of one or more monoolefins of the formula CH2xe2x95x90CHRxe2x80x2 wherein Rxe2x80x2 is an alkyl radical, usually of not more than eight carbon atoms. In particular, this invention is applicable to the following: polyethylene, both of the high-density type and the low-density type having densities within the range 0.89-0.97; polypropylene; polybutene-1; poly(3-methylbutene); poly(4-methylpentene); and linear low density copolymers of ethylene and an alpha-olefin, such as propylene, butene-1, pentene-1, hexene-1, heptene-1, octene-1, decene-1, octadecene-1, or n-methylpentene-1.
Because of the different melt characteristics of the olefin polymers mentioned, the addition of the fluoropolymer process aids of this invention may be of greater value in some polyolefins than in others. Thus, polyolefins such as polypropylene and branched polyethylene, that have low molecular weight or broad molecular weight distributions and, therefore, have good melt flow characteristics even at low temperature, may not require the use of the fluoropolymer additives or be noticeably improved by them, except under unusual, adverse extrusion conditions. However, for polymers such as high molecular weight, high density polyethylene or linear low density ethylene copolymers, particularly those with narrow or very narrow molecular weight distributions, addition of the fluoropolymers is especially beneficial.
Such polyolefins are typically processed by extrusion techniques at melt processing temperatures Tp in the range of 175-275xc2x0 C. The commercially important blown-film process is usually carried out at Tp in the range of 200-250xc2x0 C., and commonly at 200-230xc2x0 C.
The polyolefins and thus the polymer blend composition containing the fluoropolymer processing aid may contain assorted additives used in the art, such as but not limited to antioxidants, acid scavengers, light stabilizers, pigments, slip agents, and lubricants. In particular, finely divided solids such as silica or talc may be incorporated as antiblock agents.
The concentration of fluoropolymer processing aid in the host resin at fabrication into the final article should be high enough to achieve the desired effect in improving processibility, but not so high as to have adverse economic impact. The amount required can vary with the effect desired, the host resin, additives used in the host resin, and the processing conditions which may be different from the laboratory conditions reported in the following examples. Under certain conditions, concentrations of 100 ppm or less, as low as 50 ppm or even 25 ppm, can be effective. Under other conditions, the effective amount may be 1000, 2000, or even 5000 ppm. For special purposes, concentrations of 10% or even 25% may be appropriate. Thus from about 25 ppm to about 25% by weight of the fluoropolymer may be present, with preferred ranges being from about 100 ppm to about 10% by weight, and even more preferable, about 100 ppm to about 2000 ppm by weight of the fluoropolymer. The fluoropolymer processing aid can be incorporated into the host resin at the desired final concentration, or can be incorporated into a masterbatch or concentrate that is added to the host resin in a ratio calculated to yield the desired final concentration.
A novel compound herein is R6R7CFSO2R8 wherein R6 is perfluoroalkyl, perfluoroalkyl containing one or more ether oxygen atoms, perfluoroalkoxy or perfluoroalkoxy containing one or more ether oxygen atoms, R7 is perfluoroalkyl or perfluoroalkyl containing one or more ether oxygen atoms, and R8 is perfluoroalkyl. It is preferred that each of R6, R7 and R8 independently contain 1 to 30 carbon atoms. It is also preferred that R8 is perfluoro-n-alkyl containing 1 to 20 carbon atoms. It is more preferred that R6 is perfluoro-n-propoxy, R7 is trifluoromethyl, and R8 is perfluoro-n-octyl. This compound is useful as an initiator for the polymerizations described herein.
In the Examples, the 19F NMR, which is used to determine the HFP distribution in the polymer, was measured on Bruker AC 250 NMR operating at 235 MHz. Polymer samples were loaded in 5 mm NMR tubes and heated to 250 to 360xc2x0 C. in a narrow bore probe. In the melt, the methine CF""s of the HFP units appear at xe2x88x92183.5 ppm if present as isolated units, at xe2x88x92179.5 if present as head to tail diads, and at xe2x88x92177 ppm if present as head to tail triads. It is uncertain whether or not the integration for the HFP triads at xe2x88x92177 ppm also includes higher (than triads) oligomeric blocks. The amount of HFP triads was determined from the ratio of the areas of the 19F NMR signal at xe2x88x92177 ppm to the total areas of the signals at xe2x88x92177, xe2x88x92179.5 and xe2x88x92183.5 ppm.
In the Examples, 13C NMR spectra were obtained using 20 weight percent solutions of the polymers in hexafluorobenzene. Spectra were taken at 60xc2x0 C. on a Bruker AMX 360 spectrometer operating at 90.5 MHz, using proton but not fluorine decoupling, 90xc2x0 pulses, inverse gated decoupling, a 30 second recycle delay, and taking 500-2000 coadded scans per sample. Vinylidene fluoride centered sequences were identified using much the same methodology described in F. A. Bovey, et al., Macromolecules, vol. 10, p. 559 et seq. (1977), and R. E. Cais, et al., Analytica Chimica Acta, vol. 189, p. 101 et seq. (1986).
In the Examples, pressure change was used to calculate the weight of tetrafluoroethylene (TFE) added to the mixing reservoir (2). For the tetrafluoroethylene calculations in Examples 1-13, 50, 51 and 65, gauge pressure of TFE was incorrectly assumed to be absolute pressure. Based upon this incorrect assumption the quantity 160 g of TFE was shown for Examples 1-13, 50, 51 and 65. The actual TFE added in these Examples was about 217 g to 228 grams. The actual amounts of TFE that were added are shown and labeled as such in parenthesis in Examples 1 and 50,51 and 65. The table on page 12 showing Examples 1-13 reflects the actual TFE measured.
In the Examples, the following abbreviations are used:
8CNVExe2x80x94perfluoro(8-cyano-5-methyl-3,6-dioxa-1-octene)
Conv.xe2x80x94conversion
GPCxe2x80x94gel permeation chromatography
HFPxe2x80x94hexafluoropropylene
I.D.xe2x80x94inside diameter
IRxe2x80x94infrared (spectrum)
Mnxe2x80x94number average molecular weight
Mwxe2x80x94weight average molecular weight
Mvxe2x80x94viscosity average molecular weight
O.D.xe2x80x94outer diameter
PETxe2x80x94poly(ethylene terephthalate)
PMVExe2x80x94perfluoro(methyl vinyl ether)
TFExe2x80x94tetrafluoroethylene
TGAxe2x80x94thermogravimetric analysis
VF2 or VF2xe2x80x94vinylidene fluoride
In the Examples, the following materials are used:
xe2x80x9cdimerxe2x80x9dxe2x80x94a perfluorinated solvent which is defined in U.S. Pat. No. 5,237,049
FC-40xe2x80x94Fluorinert electronic liquid sold by 3M Industrial Chemicals Division, thought to be substantially perfluoro(tributylamine).
FC(copyright)xe2x80x9475xe2x80x94Fluorinert(copyright) Electronic Liquid, sold by 3M Industrial Chemicals Products Division, thought to be substantially perfluoro(2-butyl-tetrahydrofuran)
Kalrcz(copyright) Perfluoroelastomer Partsxe2x80x94a tetrafluoroethylene/perfluoro(methyl vinyl ether) and curesite monomer copolymer part available from E. I. du Pont de Nemours and Company, Inc., Wilmington, Del., USA
Kapton(copyright) Polyimide Filmxe2x80x94a polyimide film available from E. I. du Pont de Nemours and Company, Inc., Wilmington, Del., USA
Mylar(copyright) Polyester Filmxe2x80x94a poly(ethylene terephthalate) film available from E. I. du Pont de Nemours and Company, Inc., Wilmington, Del., USA
Nordel(copyright) Hydrocarbon Rubberxe2x80x94an EPDM elastomer available from E. I. du Pont de Nemours and Company, Inc., Wilmington, Del., USA
PETxe2x80x94poly(ethylene terephthalate)
Viton(copyright) Fluoroelastomerxe2x80x94a copolymer of vinylidene fluoride, hexafluoropropylene, and optionally tetrafluoroethylene made by free radical polymerization in aqueous emulsion, in a continuous process, and available from E. I. du Pont de Nemours and Company, Inc., Wilmington, Del., USA


A vehicle bed extender for attaching to a tailgate. The vehicle bed extender has a rear panel, the inner edge of which is hinged to the outer border of the tailgate. Side panels are provided, the bottom edges of which are hinged to the side border of the tailgate. The outer edges of the side panels are releasably hinged to the outer edge of the rear panel by a single hinge. The side panels have a diagonal hinge which folds inwardly when the rear panel is pushed toward the tailgate.

1. Field of the Invention
This invention is in the field of extending the length of beds of trucks and other vehicles.
2. Description of the Prior Art
British Patent No. 1,085,670 to Cronk Feb. 3, 1914--teaches a foldable carrier to be secured to the end of a vehicle in which a platform is hingedly folded down for use and up for nonuse. Straps are used to secure items stored on the platform and to secure a cover over the items to protect them from the elements. The platform apparatus is generally secured to the axle of the vehicle and has spring supports to absorb energy from the bumpy ride of the vehicle.
British Patent No. 1,280,761 to Dobbs Oct. 8, 1918--teaches an add-on carrier for luggage which is to be secured to the back end of any automobile. In its stored position the carrier is relatively flat and stored in an upright position behind the car. The bottom platform support is hinged to the mounting apparatus and can be pulled down and the back end of the carrier is hingedly secured to the bottom platform and can then be raised into position. The side panels are pivoted into place forming a box-like carrier.
U.S. Pat. No. 2,214,575 to Cercownay Sep. 16 1940--teaches an extender to a pickup truck in which an extension of the bed slides out over the opened tailgate and beyond the extension of the tailgate of the truck. A slidable support for this extension moves outwardly under this extension from the bumper and supports the extension.
U.S. Pat. No. 3,132,781 to Poczatek May. 12 1964--teaches a collapsible carrier to be positioned overlie the back bed area of a station wagon. The carrier can be supported by rollers or the like in order to permit ease in sliding the carrier toward the rear of the station wagon for ease in loading and unloading. Moreover, the rear upwardly extending wall of the carrier can be lowered to overlie the tailgate of the station wagon to protect the tailgate while loading and unloading.
U.S. Pat. No. 4,023,850 to Tillery May. 17 1977--teaches an extender for the tailgate of the pickup truck. Basically, an extension is mounted to the top of the tailgate and hinged arms support it to the side walls of the bed. This structure can be readily seen in the FIGS.
U.S. Pat. No. 4,824,158 to Peters Apr. 25 1989--teaches a carrier tray that is slidable from within the bed of the pickup truck outwardly. A support bracket is mounted to the bottom of the bed of the pickup truck in which the bracket carries the carrier tray. Once the carrier tray is inserted into the support bracket, it can be slid into storage position within the bed of the truck and can be slid into storage position within the bed of the truck and can be slid outwardly from the bed with the tailgate in a downward position. The tray can be locked in intermediate positions with the tray extending outwardly from the bed of the truck. The support bracket provides vertical support to the tray with the tray in an extended outward position. With the tray in position overlying the bed of the truck, it provides protection to the bed floor.
U.S. Pat. No. 5,090,335 to Russell Feb. 25 1992--teaches a sliding extension of the bed of the pickup truck. In which the extension in its extended position is supported at one end by the bed and at the other end with legs to the ground. This extender is not for carrying any loads with the vehicle in operation but is a portable work table.
U.S. Pat. No. 5,441,324 to Gold Aug. 15 1995--teaches an extender for a van. The open rear doors act as side walls and fold down sections from each door act as a floor extender. There is no rear wall.
U.S. Pat. No. 5,501,500 to Cannon Mar. 26 1996--teaches for an extender plate to be stored on a pickup truck and then when needed extended outwardly out of the back end of the truck bed. The extender plate in the extended position is supported by a bumper extension structure. There are no rear or side walls to the extender.


An electrochemical sensor for detecting gas includes stacked reference, counter and sensing electrodes within a body and having a quantity of a liquid electrolyte in an electrolyte chamber therein. A support is provided for holding the electrodes and mats in contact with each other and at an inner end of a cavity within the sensor. A gas passage, such as a diffusion limiter, is provided through the sensor body and permits gas to reach the sensing electrode. The reference electrode is formed in a wraparound structure, with the reference electrode provided with a plurality of integral extensions which extend around the support and the counter electrode and into contact with the liquid electrolyte, thereby providing a large reference electrode fitted into a small body.

1. Field Of The Invention
This invention relates to electrochemical gas detectors and, more particularly, to a three-electrode electrochemical sensor having a compact design.
2. Background Art
The theory and general operation of three-electrode electrochemical sensors used in toxic or other gas detector systems are well known. These sensors, also referred to as cells, typically include a sensing electrode, a reference electrode spaced from the sensing electrode by a porous separating mat containing an aqueous-based electrolyte contacting the sensing and reference electrodes through the mat, and a counter electrode also separated from the reference electrode by a porous mat containing the electrolyte, and a gas diffusion limiting means. The sensing electrode can be a porous, gas diffusion electrode having a coating of a catalytic material on the surface adjacent to the electrolyte. The gas to be sensed, referred to as the object gas, diffuses either alone or in combination with other gases through the diffusion limiting means to the sensing electrode. The object gas undergoes a reaction, either a reduction or an oxidation, at the interface of the electrolyte and the catalytic material on the sensing electrode. The catalytic material is selected to promote the reaction with a particular object gas, but to catalyze little or none of the other gases that may accompany the object gas.
The reference electrode is used in conjunction with an electronic circuit to maintain a predetermined potential difference between the sensing and reference electrodes. This potential difference also is selected so as to encourage the desired oxidation or reduction reaction of the object gas at the sensing electrode. This potential difference also is selected so that other undesirable reactions will be suppressed as much as possible and, thereby, will not interfere with the desired reaction resulting from the presence of the object gas. The predetermined potential difference between the reference electrode and the sensing electrode is maintained by the electronic circuit without drawing current from the reference electrode. Within limits, this potential difference does not affect the magnitude of the current generated by the reaction of the object gas at the sensing electrode. The magnitude of the current is controlled by the diffusion limiting means.
The result of either the oxidation or reduction reaction at the sensing electrode is the production of ions and electrons. These charged ions migrate through the electrolyte to the counter electrode. A conductive wire or other conduction path is connected external of the cell between the sensing and counter electrodes to complete the electrical path, to allow electrons to flow between the counter and sensing electrodes, and to permit another electrochemical reaction to take place at the counter electrode. With all other conditions remaining constant, such as temperature, gas pressure, and humidity, the number of electrons generated by the reaction at the sensing electrode will be directly proportional to the amount of object gas diffusing to the sensing electrode. The electronic current flowing through the external circuit between the sensing and counter electrodes can be measured by an ammeter or the like and provide a quantitative reading of the concentration of object gas present.
Prior art three-electrode electrochemical sensors useful for detecting an object gas in an atmosphere are shown, for example, in U.S. Pat. Nos. Re. 31,914, Re. 31,915 and Re. 31,916. A two-electrode sensor is shown in U.S. Pat. No. 3,755,125. However, these sensors are rather bulky due to the positioning of the electrodes with respect to each other and because they require an electrolyte reservoir in the cell.
It is, accordingly, a first object of the present invention to provide a three-electrode electrochemical sensor for gas detection which has a compact design.
The prior art has provided numerous designs of three-electrode electrochemical sensors of compact design, as shown, for example, in U.S. Pat. Nos. 4,406,770, 4,521,290, 4,633,704 and 4,769,122, and U.K. Patent Application No. 2 140 566. See also U.S. Pat. Nos. 3,950,980, 4,025,412, 4,132,616, and 4,587,003.
The reference electrodes used in three-electrode electrochemical sensors are conveniently of the air type. While the steady-state air-electrode potential depends on variables such as gas pressure, temperature, and electrolyte composition, it is desirable that the reference potential be stable. However, fluctuations from this potential do occur in normal operation. Such fluctuations affect the accuracy of the measurements developed by a sensor, render the sensor less immune to interference from other gases, and cause the sensor's operation to vary over its life. This deviation in the air reference electrode's redox potential from the theoretical value is often characterized as an instability in the reference electrode potential. The stability problems with air reference electrodes are reduced or minimized in three-electrode electrochemical sensors when the overall air reference electrode is large in size. Problems have been observed when the reference electrode is reduced to the small sizes used in compact designs. In such compact electrochemical sensors, the reference electrode is often not sufficiently stable and reproducible to provide accurate, dependable and consistent gas measurements.
Therefore, it is a second object of the present invention to provide a compact, three-electrode electrochemical sensor for gas detection which includes a large and stable air reference electrode that can operate reliably at the air-electrode potential.

Electrochemical gas sensor with wraparound reference electrode


A golf clubhead has been multi-angularly streamlined so that it presents reduced aerodynamic drag when swung throughout the entire 120 degrees prior to impact with a golf ball. During this portion of the swing, golfers typically rotate their golf club about the axis of its shaft by up to 135 degrees. During the 120 degrees of swing prior to ball impact, the club is typically accelerated from about 50 MPH to 100 MPH or more. The streamline shape is developed for higher efficiency for air flow encountered at the high speed portion of the swing arc at the expense of reduced streamline efficiency during the slower portion of the swing. The shapes herein conform to U.S.G.A. rules. Allowance is also made in the streamline shape for the non-radial sweep of the shaft during the earlier portion of the swing. In the preferred embodiment, a high strength faceplate is fitted to a low density aerodynamic fairing thereby creating a clubhead combination with a center-of-mass close to the plane of impact. The club shaft is preferably fitted to an extension of this faceplate. Test clubs have exhibited increased driving distance and increased accuracy, believed to be due to higher club speed and reduced perturbation of the club path by air turbulence.

1. Technical Field
This invention relates to golf clubs. It further relates to the aerodynamic shaping of the head of a golf club. It relates still further to an aerodynamically streamlined golf club made by the combination of a faceplate fixed to an aerodynamic fairing.
2. Description of the Prior Art
Golfe' is noted in a decree of the Scottish parliament under James II dated March 1457 at which time people seemed to be playing too much golf at the expense of their skill at bowemerkis (archery). In 1471, another decree under James III was passed to discourage golfe and futeball and in 1491 King James IV issued a decree with pains and penalties attached wherein "Futeball and Golfe Forbidden" because he decided it was degrading Scotland's level of defense preparedness against the threat of invasion by England. Shortly afterwards, James IV shifted his defense budget from the Bowers Guild to the Alchemists and the fire arms makers, and then legalized golf once again so that the suddenly unemployed Bowers could now make and sell golf clubs and support their families.
Throughout five centuries of recorded golf history, one reads of occasional conflict, usually driven by social or technological forces independent of the game. A current minor example of conflict in golf equipment utility can be found in the needs and desires of manufacturers to generate profits in juxtaposition to the desire of golf's regulating bodies to maintain the game. The development of new golf equipment has been slow during the 20th century as most of the world's scientists and engineers have taken defense related research jobs. Industries such as golf whose products relate to leisure have been unable to compete as the brightest people were employed elsewhere while leisure equipment has been left behind.
Golf clubs, to be allowed for use in tournament and competition play, must conform to the rules of The United States Golf Association (U.S.G.A.) founded in 1894 and The Royal and Ancients Golf Club (R & A, and also known as the R.A.G.C.) of St. Andrews, Scotland founded in 1754. These two groups together form the traditional regulating body governing the rules of golf and its equipment. In this capacity, the U.S.G.A. and the R & A will on occasion accept an advance in science or technology and permit the application of such to the making of a change in club or ball manufacture when in their judgement they believe such change will benefit the spirit and traditions and customs of golf.
Notable changes brought on by technology are illustrated by the development of the golf ball. The earliest known ball was the "feather", a hatful of feathers packed into a sewn up leather cover. The best player could hit a feather about 150 yards. In 1848, the "guttie" was introduced, a smooth ball made of rubbery gutta-percha which could be hit about 195 yards. A new guttie would duck and twist erratically in flight but performed better and better as it became scarred and rough. It was accordingly modified by players to make it rough and then by manufacturers who added dimples that made the flight path more predictable. In 1898, a rubber cored ball was introduced that gave a more precise trajectory than the guttie and could be hit about 255 yards by a good player. The rubber ball was more reliable in play, the guttie having had the perplexing tendency to fly into several pieces when played.
To limit the ingenuity of golf ball manufacturers, the U.S.G.A. introduced a machine in 1941 to automatically play the ball. A ball at a temperature of 23 +/-1 degree C. must not leave the machine at greater than 250 feet per second. The average distance a ball will travel in carry and roll, when driven by a standardized machine, is now limited to 280 yards.
Not all technical "improvements" have been acceptable. Several manufacturers marketed recently a new golf ball that once again improved the range obtainable with a normal drive. On this occasion, the regulating bodies judged it to be not in the best interests of the traditions and nature of golf and determined that the new ball does not conform to the rules.
Golf clubs have gone through a similar technical transition. The earliest known clubs had a wooden head fitted to a wooden shaft. In 1929, use of the steel shaft was sanctioned by the R.A.G.C. and the U.S.G.A. The head of the "wood" was then changed to a hollow steel shell, and now is permitted in a variety of metals as well as fiber reinforced plastic, the core frequently being filled with a foam plastic. The shaft may also be composed of a fiber reinforced plastic composite.
In the area of aerodynamics as applied to the golf club, some research has been done and several patents have been granted for clubs claimed to have reduced aerodynamic drag whereby the golfer can attain increased swing speed and an increased distance for the golf ball. U.S. Pat. No. 5,190,289 by Nagai et al describes the use of a wind tunnel to measure drag on a golf club. Factors such as lift and pitching moment were not mentioned however and the improvement in performance was cited as 3%.
Air resistance and drag is mentioned in U.S. Pat. No. 5,398,935 by Katayama which shows an aerodynamic shape, but does not address the changing forces as the clubhead rotates.
Iriarte in U.S. Pat. No. 5,435,558 shows a design with two channels as cavities that direct the airflow alongside the clubhead to give stabilization and minimize undesired vibration.
Davis et al in U.S. Pat. No. 5,318,297 add airfoils to stabilize and smooth out airflows on a clubhead, but in no manner would the inventions of Iriarte or Davis et al conform to the U.S.G.A. rules as they are now interpreted.
In U.S. Pat. No. 5,092,599 Okumoto et al show a spoiler on the clubhead that distorts and changes the airflow on the clubhead, but for only one specified direction of club motion.
In U.S. Pat. No. 2,447,967, Stone covered the problem of the different characteristics between the two types of clubs known as "woods" and "irons", and he attempts to improve upon this ergonomic and aerodynamic problem. His solution is based upon vibration, mechanical commonality, visual factors, and materials available. The result was a slight improvement in the aerodynamic lift characteristics of his club set.
No prior art was found regarding the problem of air flow over the clubhead as the club rotates, during a golfer's swing, about the longitudinal axis of the shaft.
The Wright brothers historic flight in 1903 and their subsequent patent showed the principle of aerodynamic lift forces through their careful study of aerodynamics as it could be applied to the shape, form, and fashion of their invention. These aerodynamic forces now affect a considerable portion of mankinds' activity and yet they are not yet utilized in the design of golf clubs.
In this invention, two aerodynamic problems of woods golf clubs were studied. The first of these problems is that of "lift" or "dive force acting on the club. In a series of tests run at Georgia Institute of Technology, School of Aerospace Engineering in their Low Turbulence Wind Tunnel, it was found that a Spalding 2 wood generated 0.144 pounds of lift directed along the axis of the shaft towards the grip at a freestream air speed of 70 feet per second flowing perpendicular to the clubface. This velocity is approximately 40% of that achieved by the professional golfer so the lift force in actual use of a club is over five times this value or approximately 0.75 pounds. Similar tests made on a Wilson 4 iron showed 0.27 pounds of lift, corresponding to approximately 1.35 pounds lift at peak swing speed.
Tests comparing other woods and irons have shown that most irons exhibit a diving force while typical woods exhibits a lifting force. This strong difference between woods and irons can of course confuse the casual golfer as he switches between say a five wood and a number one iron. The difference between the wood and the iron is really only controllable by the dedicated or professional golfer who practices driving and plays golf often enough to learn how to compensate for the differing eccentricities between his clubs.
A second aerodynamic problem occurs in golf clubs. This is that during the common golf swing of a wood or an iron, the club shaft is rotated by 90 degrees or more and in many cases as much as 135 degrees about its longitudinal axis during the 90 degrees of swing prior to striking the ball. During this same portion of the swing, the club is accelerated from approximately 65 miles per hour (MPH) to over 100 MPH, and in the case of a professional golfer, to as high as 140 MPH. Add to this the fact that golf is frequently carried on when winds or wind gusts may exceed 30 MPH, this velocity being added or subtracted from the swing velocity according to the direction of ambient wind past the golfer.
This means that airflow over the club flows from the heel to the toe when the shaft is horizontal (at 90 degrees prior to impact) and has shifted to flow from the face to the back of the clubhead when the club is reaching impact.
Another factor to consider in a study of aerodynamic effects on the clubhead is that a blunt clubhead will generate von Karman vortices behind it when traveling at these speeds. Such vortices grow in size and follow behind the clubhead, then break away only to be immediately followed by growth of a new vortex of opposite rotational direction which repeats the process.
The problem with such vortices is twofold. First, the alternating vortices create an oscillating force on the body which is generally perpendicular to the direction of air flow and which may equal or even exceed the magnitude of the previously mentioned lift forces. In this case the oscillating force will operate in the same direction as the maximum component of the lift/dive forces. Such an oscillating force on the clubhead when it is only supported by a limber shaft can cause it to deviate from its non-perturbed flight path and cause a poor shot or even a miss altogether.
The second problem is that these vortices indicate that a high drag factor is operating. Such drag of course will decrease club speed and diminish the distance obtained with the ball.


An apparatus is provided for controlling the flow of air for external cooling of a tubular film issuing from an extruder head. To ensure that the flow of the air for external cooling to the point at which the tubular film begins to expand can be controlled regardless of the distance from that point to the extruder head, flow-directing flaps are evenly distributed around the tubular film and are displaceable along the tubular film.

1. Field of the Invention
This invention relates to an apparatus for controlling the flow of air for external cooling of a tubular film, issuing from an extruder head.
2. Description of the Prior Art
Such an apparatus is known from U.S. Pat. No. 4,209,475. In the known apparatus the air for external cooling is supplied through the extruder head in passages, which are disposed radially outwardly of the die through which the extrudate is discharged from the extruder head, and longitudinally adjustable, upwardly inclined plates extend into said passages.
The known apparatus can be used only when the extruder is operated in the so-called "short-neck" mode. On the other hand, if a tubular film is to be extruded in the so-called "long-neck" mode, the known apparatus will no longer be sufficient because in that case the region in which the tubular film is expanding is too far away from the extruder head so that the known apparatus can no longer act on said region.

Apparatus for controlling the flow of air for external cooling of an extruder tubular film


The invention discloses a fermentation method for production of fucoxanthin by Nitzschia laevis, including the following steps of: step A, preparation of inocula; step B, fermentation culture: inoculating of Nitzschia laevis according to a certain volume ratio to reaction kettle containing sterile fermentation medium for aeration fermentation, preparing fucoxanthin fermentation broth through culture mean of fed-batch nutrient components; step C, obtaining high fucoxanthin induction culture solution by aeration induction culture under irradiation of monochromatic light or mixed light; extracting fucoxanthin from high fucoxanthin induction culture solution. The invention optimized fermentation condition by fed-batch nutrient components during aeration culture of alga Nitzschia laevis, thereby significantly increasing the cell density of Nitzschia laevis in sterile fermentation broth, and then treating high density fucoxanthin induction culture solution of Nitzschia laevis by using light treatment, inducing the accumulation of fucoxanthin, thereby further increasing productivity of fucoxanthin produced by fermentation.

Fucoxanthin is mainly derived from large seaweed and microalgae such as Laminaria japonic, diatoms and golden algae. It is a natural carotenoid and participates in reaction of photosystem II in photosynthesis. Fucoxanthin harbors a very unique structure with an allenic bond endowing fucoxanthin with special properties. In recent years, studies have found that fucoxanthin has multiple functional activities in cells, animals, and humans, including antioxidant, anti-inflammatory, anti-cancer, anti-obesity, anti-diabetic, anti-angiogenic, and anti-malarial activities. It has protective effects on organs such as liver, brain blood vessels, bones, skin and eyes. Based on the above functions, fucoxanthin is a natural product with broad prospects for health food and drug development. The market capacity of fucoxanthin is 500 tons, and the price of a 10% fucoxanthin extract (w/w) reaches over 40,000 RMB/kg. Therefore, it has great market value.
The significant role of fucoxanthin in weight loss has attracted more and more attention. It can achieve weight loss by inhibiting the formation of fat cells and accelerating fat catabolism. Currently, fucoxanthin is mainly extracted from large seaweeds such as Undaria pinnatifida and Laminaria japonica. However, the use of marine macroalgae as a source of fucoxanthin has important shortcomings, such as thick cell wall, high polysaccharide content, difficulty in purification, and marine pollution. Furthermore, the fucoxanthin content in seaweeds is extremely low (only 0.01%-0.07% of cell dry weight), which limits its application. The content of fucoxanthin in marine microalgae reach up to 0.6% (of cell dry weight), which is nearly 100 times that of large seaweeds. Therefore, microalgae are better alternative sources of fucoxanthin.
Nitzschia laevis is a unicellular alga belonging to Bacillariophyta. There are few studies on the production of fucoxanthin by Nitzschia laevis. The applicant's previous research found that the Nitzschia laevis had the highest fucoxanthin productivity of 9.88 mg/(L·d), and could be cultured heterotrophically without light (Application Number: 201710523735.6). Nitzschia laevis, a unicellular plant, contained a fucoxanthin content of up to 1.38% (of dry cell weight) with autophototrophic culture, but the biomass concentration is very low, usually less than 1 g/L (Patent Application Number: 201710525234.1). After fermentation optimization, the cell density of Nitzschia laevis was up to 21.2 g/L, which was 20-30 times that of autophototrophic culture. However, the fucoxanthin content in the cells after fermentation was only 0.75% (accounting for dry weight of cell). It is only half of the culture under autophototrophic culture conditions. Therefore, how to effectively improve the fucoxanthin content in the Nitzschia laevis fermentation broth prepared by heterotrophic culture has become one of the technical problems to be solved in this process.
The applicant found through retrieving that Qi (2015) found different light quality (blue light, green light and red light) had significant effects on fucoxanthin content of the diatom Phaeodactylum tricornutum under autophototrophic culture conditions (Chinese Marine Science, 2015, 39(7): 1-6). Red light promoted the growth of Phaeodactylum tricornutum and increased the content of fucoxanthin, while green light and blue light inhibited cell growth and reduced the content of fucoxanthin. However, Phaeodactylum tricornutum was cultured by continuous irradiation of monochromatic light. Heui-Chun et al. studied the effects of different light qualities (blue, green, red and white) on the accumulation of fucoxanthin in the Chaetoceros calcitrans, and found that blue light stimulated the accumulation of fucoxanthin. Red light inhibited the accumulation of fucoxanthin. But this research used Chaetoceros calcitrans, and used continuous irradiation culture through monochromatic light. There was rare investigation on the heterotrophic culture characteristics of algae and the effects of cells after fermentation on the accumulation of fucoxanthin. (Bulletin of the Korean Society of Fisheries Technology, 2014, 50: 447-454). To the best of applicants' knowledge, this is the first effort to figure out the effect of light quality on fucoxanthin accumulation of in Nitzschia laevis.

Fermentation method for production of fucoxanthin by


A method and device for enhanced capture of target analytes is disclosed. This invention relates to collection of chemicals for separations and analysis. More specifically, this invention relates to a solid phase microextraction (SPME) device having better capability for chemical collection and analysis. This includes better physical stability, capacity for chemical collection, flexible surface chemistry and high affinity for target analyte.

Solid phase microextraction (SPME) is a demonstrated and attractive method for sampling and preconcentrating trace level analytes, since it is a flexible, rapid, solvent-free extraction technique that is applicable to liquid and/or gas sampling environments. Further, SPME can be directly interfaced with wide range of analytical instrumentation for analyte detection such as gas chromatography (GC), gas chromatography mass spectroscopy (GC-MS), high-performance liquid chromatography (HPLC), liquid cromotography mass spectroscopy (LC-MS), and desorption electrospray ionization mass spectroscopy (DESI-MS), making it amenable to automation and a convenient technique. Due to its broad applicability and sensitivity SPME has been widely utilized in a variety of fields.
SPME was first successfully developed as a polymer coating on silica fibers in the early 1990s and, presently, various polymer phases are available commercially. Many types of polymers and composites with different chemical characteristics are available for the extraction of a variety of analytes of interest. Since polymer phases can be blended, different surface properties of polymers can simply be coated and tailored onto a single fiber. This leads to a certain extend application of polymer coated fibers in many fields.
However, a number of drawbacks of polymer SPME sometimes limit their applications. They are unstable with some solvents, have insufficient mechanical strength and tend to degrade at high operating temperatures. Additionally, the coatings are occasionally stripped, and they suffer from contaminations and unstable coatings on new fibers.
The demand for better chemical capacity, sensitivity, selectivity, as well as thermal, chemical, and mechanical stability has pushed continued research in the SPME field. Since the fiber coating is one of the most significant factors impacting SPME function, many different approaches have been explored to improve performance. For example, the sol-gel technology physically incorporated with polydimethysiloxane (PDMS) has been shown to enhance the thermal stability and sensitivity higher than normal PDMS. The planar geometry substrate was first applied for PDMS coating in order to increase the surface area and volume of the polymer phase, which subsequently enhances the capacity of SPME.
Certain coating polymers and polymer composites (i.e. BSP3 polymer, acrylate/silicone co-polymer, polyrrole, poly(phthalazine ether sulfone ketone)) and different preparation techniques (i.e. electrochemical, molecular imprinting, physical deposition) have also been employed to SPME for improved performance of the polymer coating.
SPME with nonpolymer coatings has been explored to overcome some of weakness of polymer coatings, specifically the limited capacity, selectivity, and chemical and thermal stability. Inorganic porous sorbents with high surface area such as, carbon nanotubes, activated charcoal, and porous silica coated SPME have been explored and reported to be effective materials for improvement in the extraction of analytes for some conditions. Metals and metal oxides such as, La (III), Al, and Nb2O5 have been investigated and developed for enhanced capturing and releasing of target analytes.
Among alternative nonpolymeric SPME materials, silica and silica composites are among the most promising coating materials. Some nanoporous silica materials can have a very high surface area per unit volume, sometimes over 1000 m2/g, while retaining hydrothermal stability. Further, they are amenable to the installation of a wide range of surface chemistries. However, integrating the silica materials into a functioning SPME device is not a trivial task. Challenges include the fragile nature of fused silica support fibers (which need extra care during SPME manufacture and application), the brittleness of ceramic coatings, and the challenge of creating a uniform thin film on the silica support fiber. It is important to maintain the available surface area of nanoporous silica material during the attachment process of coating to the support. The retention of a large relative surface area offers installation of selective silane functional groups (able to obtain high density of binding sites), resulting in high sorption capacity and sensitivity to analytes of interest. Effectively attaching nanoporous material onto the SPME fibers depends upon the attachment method. A glue method utilizing epoxy has been reported for attaching functionalized/unfunctionalized mesoporous silica and other porous silica particles onto SPME supports.
Rapid detection of organic chemicals is important for a range of areas including biomedical, agricultural, industrial, environmental, forensic and a range of health and safety related areas. The threat of terrorism has heightened the significance of rapid fieldable detection of trace level organics for security concerns. SPME is an ideal approach for improving methods for sampling and analysis of the forensic signatures, chemical weapons and explosives.
What is needed is a device and method of making with improved capacity for trace analyte capture, enhanced affinity and selectivity of target analytes.

Device and method for enhanced collection and assay of chemicals with high surface area ceramic