The invention relates to a semi-permeable membrane separation process and device in which the said membranes comprise sulphonated polyimides.

The invention relates to a semi-permeable membrane separation process and device in which the said membranes comprise sulphonated polyimides.
The present invention also relates to the use of sulphonated polyimide membranes in separation processes and devices using semi-permeable membranes.
In a general manner, the technical field of the invention can be described as that of industrial processes, in particular separation processes using semi-permeable membranes.
The first characteristic of the membranes used in these processes is that they favour the movement of certain species. The membrane is therefore considered to have a certain selectivity which, associated with the permeation flow, allows the performance of the membranes to be defined.
Amongst semi-permeable membranes, ion exchange membranes or ionic membranes are very widespread and very widely used.
They are used, in particular, in processes that use an electrical field to favour the transfer and the separation of different species of ion, such as electro-dialysis, electro-osmosis or in electrochemical cells used in the treatment of various effluents, in this latter case, the membranes then act as separators between the anodic and cathodic compartments.
Two types of ion exchange membranes are mainly distinguished:
anionic membranes, which are only permeable to anions and whose functional group is, for example, a quaternary ammonium group.
cationic membranes, which are only permeable to cations and whose functional group is, for example, an acid group.
The properties of the membranes, which determine the general properties of the processes and the devices which are used in them, are mainly permselectivity, selectivity, ionic conductivity, electrical resistance and mechanical strength.
Permselectivity, or the cationxe2x80x94anion transfer restriction factor, is one of the fundamental properties of an ion exchange membrane. It is characterised by the value of the transfer number of the mobile ion or counter ion (in other words, the ion which should normally pass through the membrane; in the case of a cationic membrane, the counter ion is thus the cation) in the membrane.
By definition, the transference number for a perfectly permselective membrane is equal to one. In fact, it is more accurate to measure the increase in the transference number value in the membrane compared to its value in solution. The permselectivity of a membrane is therefore actually defined by:   Ps  =                    t        ~            -      t              1      -      t
where {overscore (t)} is the transference number of the counter ion in the membrane and t is the transference number of the said ion in the solution.
The permselectivity of a membrane must be as high as possible; the permselectivity of most membranes is generally greater than 80%.
Selectivity is defined in a more or less analogous manner, as being the transference restriction factor between two ions with the same polarity. This selectivity must also, preferably, be as high as possible.
The ionic conductivity of the membrane, expressed by "sgr" in S.cmxe2x88x921, must be as high as possible and depends, amongst other things, on the structure of the membrane (swelling, concentration in groups of exchangers and physical structure).
The electrical resistance of the membrane must be as low as possible, in such a way that it does not lead to too high consumption of energy; the electrical resistance is, for a given conductivity, proportional to the thickness of the membrane.
The mechanical strength of the membrane must also be high in order to resist any pressure differences and stresses that may occur during the manufacture of the devices.
Other important properties are the temperature resistance, which must be as high as possible, in order to make it possible to treat media at high temperature, and the resistance to extremes of pH, in other words, very basic or very acidic and/or very oxidising media.
In the conditions of use corresponding to extremely acidic pHs or in very oxidising media, the operational life of the membranes can be very limited.
It has been observed that the membranes presently available for semi-permeable separation processes or devices do not meet all of the criteria and requirements mentioned above while, at the same time, being at an acceptable cost. In particular, membranes that can operate in extreme pH media, for example, very acidic and/or very oxidising media, are certainly known, but they do not meet one or all of the other criteria defined above and they are very expensive.
The document FR-A-2 050 251 describes sulphonated polyimides and their use as cationic membranes in electro-dialysis. However, these polymers, due the process used for their preparation, are completely statistical polymers with a random structure whose properties, such as conductivity, are completely uncontrolled and difficult to master. As a result, these polymers are unsuitable for applications in any separation process and do not meet, in fact, any of the criteria defined above.
There is therefore a need for a semi-permeable membrane separation process and device in which the said membranes meet all of the criteria mentioned above and which have improved performance compared to existing membranes.
Furthermore, there is also a need for a process and a device whose membranes are not expensive to manufacture and whose resistance in extremely acidic pH media and/or very oxidising media is excellent.
The aim of the invention is to provide a semi-permeable membrane separation process and device in which the membranes meet the requirements mentioned above, and which do not have the demerits, disadvantages, defects or limitations of the processes and devices of the prior art and which overcome the problems of the prior art.
This aim and others are achieved according to the invention by a semi-permeable membrane separation process in which the said membrane(s) comprise a sulphonated polyimide that has the following general formula (I):
In which the groups C1 and C2 may be identical or different, and each represent a tetravalent group comprising at lease one aromatic carbon ring, which may be substituted, having 6 to 10 carbon atoms and/or a heterocyclic ring with an aromatic character, which may be substituted, having 5 to 10 atoms and comprising one or several heteroatoms chosen from the group S, N and O: C1 and C2 each form, with the neighbouring imide groups, rings with 5 or 6 atoms.
The groups Ar1 and Ar2 may be identical or different, and each represent a divalent group comprising at least one aromatic carbon ring, which may be substituted, having 6 to 10 carbon atoms and/or a heterocyclic ring with an aromatic character, which may be substituted, having 5 to 10 atoms and comprising one or several heteroatoms chosen from the group S, N and O: at least one of the said aromatic carbon and/or heterocyclic rings of Ar2 being, in addition, substituted with at least one sulphonic acid group. In the formula (I), each of the groups R1 and R2 represent NH3, or a group with the formula:
Where C3 is a divalent group comprising at least one aromatic carbon ring, which may be substituted, having 6 to 10 carbon atoms and/or a heterocyclic ring with an aromatic character, which may be substituted, having 5 to 10 atoms and comprising one or several heteroatoms from the group S, N and O; C3 forming, with the neighbouring imide group, a 5 or 6 atom ring.
In addition, in the formula (I) above:
m represents a whole number, preferably between 2 and 20, and even more preferably, between 2 and 10
n represents a whole number, preferably between 2 and 30, and even more preferably, between 2 and 20
o represents a whole number, preferably between 2 and 10, and even more preferably, between 2 and 6.
The copolymer used in the process according to the invention may be defined as being a sequenced or block copolymer comprising two types of structures.
The molecular weight of the polyimide according to the invention is generally between 10 000 and 100 000, and preferably between 20 000 and 80 000.
The equivalent molecular weight of the polyimide according to the invention is preferably between 400 and 2 500 and, even more preferably, between 500 and 1 200.
The equivalent molecular weight is defined as the weight of the polymer in grams per acid equivalent.
As a result, the numbers m and n will be selected in such a way so that the equivalent molecular weight is between 400 and 2 500, and even more preferably between 500 and 1 200.
In a general manner, it is known that heterocyclic polymers and, in particular, polyimides, allow films to be formed, thanks to their synthesis in two stages.
These xe2x80x9cheterocyclicxe2x80x9d polymers are used, for example, in aeronautic and space applications, which require excellent mechanical properties and good oxidation resistance. These applications are very far from the scope of the present application.
The specific sulphonic copolyimides of the present invention are described, in part, in document FR-A-2 748 485.
This document indicates that these polymers have the properties required for making membranes and, in particular, cation exchange membranes, specifically designed for fuel cells, and their performance characteristics are essentially compatible with applications in fuel cells.
In particular, these copolymers can be easily formed into films or membranes with an adequate thickness.
These copolymers have a very high ion exchange capacity, greater than 0.4 meq/g, for example, from 0.8 to 2.5 meq/g.
Membranes made out of these polymers also have very good thermal stability and particularly high temperature acid hydrolysis resistance, in other words, the most stable membranes can go up to a temperature of, for example, 100 xc2x0 C. and moreover, for long periods, for example, 3 000 hours.
These conditions are application conditions that can arise in fuel cells where the membranes, described in this document, are mainly used.
In the same way, the membranes described in this document have excellent resistance to reduction and oxidation.
The membranes comprising the sulphonated polyimides, described above, have therefore been developed with the specific purpose of their being used in fuel cells and their mechanical, physical, chemical and electrical properties are thus specific to this limited application field.
However, it has been shown that membranes comprising certain sulphonated polyimides, cited above in the document FR-A-2 748 485, also posses, in a totally unexpected manner, particularly excellent selectivity and permselectivity properties, which make them, in a 15 surprising manner, particularly suitable for use in semi-permeable membrane separation processes. These are sequenced polymers with the formula (I).
In a general manner, the permselectivity Ps of the membrane according to the invention is between 90 and 100 %, without this range being limiting; in fact, Ps depends on the electrolytic concentration and, for example, if a Ps of 75 % can be considered as poor for concentrations of 1 M, it is excellent for a concentration of 4 M.
Also in a general manner, the selectivity H+/ MZ+, where Z is generally a whole number between 1 and 6 (Z=1, 2, 3, 4, 5, 6), is between 0.70 and 0.95, without this range being limiting; in fact, as for Ps, the selectivity depends, for example, on the nature of the cation associated with the proton, the ratio H+/ Mz+, and certainly the total concentration of cations.
For example, the membranes according to the invention have a permselectivity Ps of between 100 and 95 % in aqueous hydrochloric acid solutions with respective concentrations of 0.1 molar and 1 molar.
Moreover, the membranes according to the invention have, for example, a selectivity, measured by the transference number of the proton under a current equal to 0.76, 0.80 and 0.91, for the cation pairs H+/Na+, H+/Cu2+, and H+/Cr3+, in equimolar H++Mz+ aqueous solutions with a total cation concentration equal to 0.1 mole concentration per liter and under an applied current density of 100 A per m2.
These permselectivity and selectivity properties are not described in the document FR-A-2 748 485 and can absolutely not be inferred from this document, which exclusively concerns the application of these membranes in fuel cells, in which such properties are not at all sought.
Furthermore, in a particularly advantageous manner, one can easily vary and adapt the selectivity and/or permselectivity properties of the sulphonated polyimides of the membranes used in the invention process by modifications to the synthesis of the sulphonated polyimide by changing, for example, the nature of the dianhydrides and the diamines, the concentration of the sulphonic groups, the concentration of these groups, etc.
In this way it will be possible to very easily adapt the selectivity and permselectivity of the polyimide as a function of the desired specific application.
The permselectivity and selectivity values cited above are, in a surprising manner, considerably improved compared to other values shown by semi-permeable membranes used in the prior art, such as Nafion(copyright) membranes.
The semi-permeable membrane separation process according to the invention, in which the said membrane(s) comprise a sulphonated polyimide with the formula (I) above, have, on the one hand, all of the advantages linked to the new properties of selectivity and permselectivity of these membranes and, on the other hand, all of the advantages linked to the properties of these membranes, already mentioned above and, in particular, good conductivity and excellent behaviour in acidic media.
It is, moreover, extremely important to note that, amongst the polymers described in the document FR-A-2 748 485, which can also be statistical sequenced polymers (namely with n and m equal to 1), only ordered sequenced (xe2x80x9cblockxe2x80x9d) polymers, described by the formula (I) above have been retained for use in the semi-permeable membrane separation process of the invention. This specific chemical structure of the formula (I) allows, also, a specific physical structure (a xe2x80x9cblockxe2x80x9d structure) of the semi-permeable membrane, which is fundamentally the basis of the surprising and advantageous properties of these membranes, to be obtained, which makes them particularly suited to a semi-permeable membrane separation process. These surprising properties cannot, in any case, be shown by statistical polymers, such as those described in the document FR-A-2 050 251, Thus, the structure of the polymers of formula (I) with, in particular, a perfectly defined distribution of the sulphonic groups in the different sequences, right along the polymer chain, is especially the reason for the excellent and better conductivity of the membranes specifically used in the invention, which leads, in particular, to a better yield when they are used in the separation process according to the invention.
In the statistical, random polymers of the document FR-A-2 050 251, the distribution of the sulphonic groups in the polymer is completely random and anarchic, and as a result the conductivity is mediocre and uncontrollable. The specific chemical structure of sequenced, ordered polymers with the formula (I) induces a physical structure that gives better resistance to chemical attack and/or electrochemical attack and better ageing resistance in the operating conditions of the membranes, which are those of the separation process according to the invention. Once again, such a physical structure cannot be obtained with the statistical polymers of document FR-A-2 050 251, which have a poorly defined structure.
The process according to the invention thus provides a solution to the problems that are posed in semi-permeable processes according to the prior art using other membranes, due to the fact that the semi-permeable membranes used in the process according to the invention meet, simultaneously, all of the criteria defined previously and have, moreover, improved permselectivity and selectivity compared to membranes of the prior art. As a result, the process according to the invention has better efficiency and provides a considerable saving in energy compared to the prior art.
In a particularly advantageous manner, it turns out that the process according to the invention may be carried out with extremely acidic pH media and/or very oxidising media, without the operational life of the membranes being reduced in a prohibitive manner.
The process according to the invention, carried out with such media, is low cost, linked to the low cost of the specific membranes used according to the invention. In fact, the production cost of these membranes isxe2x80x94at identical, or even superior, performancexe2x80x94considerably lower than that of existing semi-permeable membranes, which operate in extreme pH and/or very oxidising media.
In fact, the polyimides that are used in the manufacture of the membranes used according to the invention are prepared in a simple manner using proven industrial methods and from raw materials that are available and not expensive.
In the formula (I) cited above, C1 and C2 may be identical or different and each represent, for example, a benzene ring, which may be substituted by one or two substituents chosen from alkyl and alkoxy groups with 1 to 10 C and halogen atoms; or several benzene rings which may be substituted by one or several subsituents chosen from alkyl and alkoxy groups with 1 to 10 C atoms and halogen atoms, for example between 2 and 4 rings, linked to each other by a single bond or by a divalent group.
The said divalent group is chosen, for example, from:
a divalent group derived from a linear or branched alkyl group (for example, an alkylidene or alkylene group) with 1 to 10 C atoms, which may be substituted, preferably on the same carbon atom, by one or several halogens chosen from F, Cl, Br and I and/or by one or several hydroxyl groups and, even more preferably, the said divalent group is a divalent group derived from a perfluorated alkyl group, for example, perfluorated alkylene.
a heteroatom chosen from O, S
a group
a group
a group
a group
a group
a group
where R3 is chosen from alkyl groups with 1 to 10 C atoms such as methyl, ethyl, isopropyl, etc.
C1 and C2 may also each represent a condensed polycyclic carbon group, which may be substituted by one or several substituents chosen from the alkyl and alkoxy groups with 1 to 10 C atoms and halogen atoms, comprising, for example, from 2 to 5 benzene rings, chosen, for example, from naphthalene, phenanthrene, coronene, perylene, etc.
C1 and C2 may also each represent a heterocycle or a condensed heterocycle, with an aromatic character, such as thiophene, pyrazine, pyridine, furan, quinolene, quinoxaline, isobenzofuran; this heterocycle, which may be substituted by one or several substituents chosen from the alkyl groups (for example, methyl, ethyl, isopropyl, etc.) and alkoxy groups with 1 to 10 C atoms, and the halogen atoms (F, Cl, Br, I).
Amongst the polyimides that may be used within the scope of the invention, one can cite those in which C1 is a benzene ring and C2 a set of two benzene rings linked to each other by an oxygen bridge; or C1 comprises benzene rings, and even more preferably, two benzene rings linked to each other by one or several perfluoroalkylene groups and C2 comprises benzene rings and, even more preferably, two benzene rings linked to each other by one or several divalent perfluoroalkyl or perfluoroalkylene groups; or C1 is a benzene ring and C2 a naphthenic ring; or C1 and C2 are both naphthalene rings.
Ar1 and Ar2 may be identical or different and each represent, for example, a divalent benzene ring with meta or para links; which may be substituted by one or several subsituents chosen from the alkyl and alkoxy groups with from 1 to 10 C atoms such as methyl, ethyl, isopropyl, butyl, methoxy, etc., and halogen atoms; or several benzene rings, which may be substituted by one or several substituents chosen from the alkyl and alkoxy groups with from 1 to 10 C atoms and the halogen atoms, for example, with 2 to 5 rings, linked to each other by a single bond or by a divalent group. The said divalent group is chosen, for example, from:
a heteroatom, chosen from O, S
a group
a group
a group
a group
a group
a group
where R3 is chosen from alkyl groups with 1 to 10 C atoms such as methyl, ethyl, isopropyl, etc.
Ar1 and Ar2 may also each represent a condensed polycyclic carbon group, which may be substituted by one or several substituents chosen from the alkyl and alkoxy groups with 1 to 10 C atoms and the halogen atoms, comprising, for example, 2 to 5 benzene rings, chosen, for example, from naphthalene, phenanthrene, coronene, perylene, etc.
Ar1 and Ar2 may also represent, for example, a heterocycle or a condensed heterocycle with an aromatic character, for example thiophene, pyrazine, pyridine, furan, quinolene, quinoxaline, isobenzofuran, and this heterocycle may be substituted by one or several substituents chosen from the alkyl and alkoxy groups with 1 to 10 C atoms, for example, methyl, ethyl, isopropyl, methoxy, and the halogen atoms (F, Cl, Br, I).
According to the invention, at least one of the cycles of Ar2, for example benzene or polyphenyl or others, is substituted, in addition, by one or several sulphonic acid groups.
The preferred polymers are those in which Ar1 is a diphenylmethane group and Ar2 is a biphenyl-disulphonic group; or Ar1 is a benzene group and Ar2 is a biphenyl-disulphonic group; or Ar1 is a diphenylether group and Ar2 is a biphenyl-disulphonic group.
C3 is, for example, a benzene or naphthalene ring, which may be substituted by one or several substituents chosen from the alkyl and alkoxy groups with 1 to 10 C atoms and the halogen atoms.
Examples of C1 and C2 groups are as follows:
Examples of Ar1 groups are as follows:
Examples of Ar2 groups are as follows:
Amongst the Ar2 groups, one can also site any of the Ar1 groups cited above bearing, in addition, one or several SO3H group(s) on its or their ring(s) and/or heterocycle(s).
Examples of C3 groups are as follows:
The polyimides used in the process and the device according to the invention may be obtained by any process known to those skilled in the art for the preparation of polyimides in general.
Examples of known processes for the preparation of polyimides are, notably, as follows:
reaction of a dianhydride with a diamine
reaction of a diacid diester with a diamine
It is obvious that the polyimides according to the invention can be prepared by processes deriving from the processes cited above.
Any necessary process adaptations and optimisations known and described in the literature can be easily made by those skilled in the art.
Preferably, one uses to prepare the polyimides according to the invention, the condensation of dianhydrides with diamines via a two stage synthesis.
This type of process if completely different to the preparation process described, for example, in the document FR-A-2 050 251, in which the polymerisation is carried out in the polyamide form and a subsequent thermal treatment allows the cyclisation reaction to take place in order to obtain heterocyclic polyimide structures from polyamic acids. On the contrary, in the preparation process used preferably in the present application, the polymerisation involves a polycondensation reaction between dianhydrides, for example, naphthalenic dianhydrides and diamines. The imide structures therefore exist beforehand and no subsequent treatment is necessary.
This fundamental difference between the synthetic approach used to prepare the polyimides according to the invention and that in document FR-A-2 050 251 has a consequent effect on the structure of the polyimides obtained and, in particular, on the distribution of the sulphonic groups along the polymer chains: this distribution is statistical and random when the process described in the document FR-A-2 050 251 is used, while it is totally modulable between statistical andxe2x80x94specifically for polymers with formula (I)xe2x80x94blocks or sequences of different lengths, thanks to the two stage synthesis process used according to the invention.
It is precisely the specific, ordered and sequenced chemical structure of the polymers of formula (I) that confers them with, as indicated previously, the advantageous properties profitably highlighted in the separation process according to the invention.
The two stage synthesis process is widely used in industry and only requires slight adaptations to allow the polyimides according to the invention to be prepared.
The synthesis of a condensation polyimide thus generally conforms to the following two stage diagram:
In the first stage, the condensation reaction of a dianhydride and a diamine is carried out in order to obtain an intermediate polyamidexe2x80x94acid with the formula (VI), termed xe2x80x9cprepolymerxe2x80x9d, according to the diagram below, given for the first type of recurrent polyimide structure according to the invention:
or according to the diagram below for the second type of recurrent polyimide structure according to the invention:
The initial reaction products, whether they are the dianhydrides (II) (IIxe2x80x2) or the bi-primary diamines (III) (IV) are products that are easily obtainable and, for the most part, not very expensive.
As a result, and in compliance with one of the particularly interesting characteristics of the present application, the polymers prepared, and as a result, the membranes obtained from these polymers, have a relatively low cost; around, for example, one tenth of the cost of membranes prepared according to the previous art, which are presently used in semi-permeable membrane devices and processes.
One can thus envisage, a consequent reduction in the cost price of these devices.
Amongst the dianhydrides with a general formula (II):
Where C1 has the signification already given above.
One can cite, as an example, the dianhydrides of the following aromatic tetracarboxylic acids: benzene-1,2, 3,4-tetracarboxylic acid; benzene-1,2,4,5-tetracarboxylic acid; 1,1xe2x80x2-biphenyl-2,3xe2x80x2,5xe2x80x2,6xe2x80x2-tetracarboxylic acid; 1,1xe2x80x2-biphenyl-3,3xe2x80x2,4,4xe2x80x2-tetracarboxylic acid; 1,1xe2x80x2-biphenyl-2,2xe2x80x2,3,3xe2x80x2-tetracarboxylic acid; 1,1xe2x80x2,1xe2x80x3-terphenyl-2xe2x80x2,3xe2x80x2, 5xe2x80x2,6xe2x80x2-tetracarboxylic acid; naphthalene-1,2,5,6-tetracarboxylic acid; naphthalene-2,3,6,7-tetracarboxylic acid; naphthalene-1,2,4,5-tetracarboxylic acid; naphthalene-1,4,5,8-tetracarboxylic acid; perylene-3,4,9,10-tetracarboxylic acid; phenanthrene-1,8,9,10-tetracarboxylic acid; 4,4xe2x80x2-oxybis-(benzene-1,2-dicarboxylic acid); 4,4xe2x80x2-thiobis-(benzene-1,2-dicarboxylic acid); 4,4xe2x80x2-sulphonylbis-(benzene-1,2-dicarboxylic acid); 4,4xe2x80x2-methylenebis-(1,2-dicarboxylic acid); 4,4xe2x80x2-difluoromethylene-bis-(benzene-1,2-dicarboxylic acid); 3,3xe2x80x2-carbonylbis-(benzene-1,2-dicarboxylic acid); 4,4xe2x80x2-carbonylbis-(benzene-1,2-dicarboxylic acid); 4,4xe2x80x2-methyl-1-ethylidene-1,1xe2x80x2-bis-(benzene-1,2-dicarboxylic acid); 4,4xe2x80x2-trifluoromethyl-1-trifluoro-2,2,2-ethylidene-1,1-bis-(benzene-1,2-dicarboxylic acid); 4,4xe2x80x2-phenylene-1,3-bis(carbonylbenzene-1,2-dicarboxylic acid); 4,4xe2x80x2-phenylene-1,4-bis(carbonylbenzene-1,2-dicarboxylic acid); 4,4xe2x80x2-phenylene-1,3-bis-(oxybenzene-1,2-dicarboxylic acid); 4,4xe2x80x2-phenylene-1,4-bis-(oxybenzene-1,2-dicarboxylic acid): 4,4xe2x80x2-methyl-1-ethylidene-1,1bis-(phenyl-1,4-oxy)-bis-(benzene-1,2-dicarboxylic acid); pyrazine-2,3,5,6-tetracarboxylic acid; thiophene-2,3,4,5-tetracarboxylic acid and 3,3xe2x80x2,4,4xe2x80x2tetracarboxy-benzanilide.
The dianhydrides of the general formula (IIxe2x80x2):
where C2 has the signification already given above and may be chosen from the same compounds cited above for the dianhydrides of formula (II).
Amongst the biprimary diamines of formula (III) H2Nxe2x80x94Ar1xe2x80x94NH2 where Ar1 has the signification already given above and which may be used in the preparation of the polyimides according to the invention, one may cite, for example: 1,3-benzene diamine; 1,4-benzene diamine; 6-methyl-1,3-benzene diamine; 2-methyl-1,3-benzene diamine; 5-methyl-1,3-benzene diamine; 4,4xe2x80x2-diamino-1,1xe2x80x2-biphenyl; 4,4xe2x80x2-diamino-3,3xe2x80x2-dimethyl-1,1xe2x80x2-biphenyl; 4,4xe2x80x2diamino-3,3xe2x80x2-dimethoxy-1,1xe2x80x2biphenyl; 4,4xe2x80x2-diamino-3,3xe2x80x2-dichloro-1,1xe2x80x2biphenyl; 4,4xe2x80x2-methylenebis-(benzene amine); 3,3xe2x80x2-methylenebis-(benzene amine); 4,4xe2x80x2-methylenebis-(methyl-3,3xe2x80x2-benzene diamine); 4,4xe2x80x2-methylene-bis(isopropyl-3-benzene amine); 4,4xe2x80x2-oxybis (benzene amine); 3,3xe2x80x2-oxybis-(benzene amine); 4,4xe2x80x2-carbonylbis-(benzeneamine); 3,3xe2x80x2-carbonylbis-(benzene amine); 4,4xe2x80x2-thiobis-(benzene amine); 3,3xe2x80x2-thiobis-(benzene amine); 4,4xe2x80x2-sulphonylbis-(benzene amine); 3,3xe2x80x2-sulphonylbis-(benzene amine); 4,4xe2x80x2-hydroxymethylenebis-(benzene amine); 3,3xe2x80x2-hydroxymethylenebis-(benzene amine); 4,4xe2x80x2-difluoro-methylenebis-(benzene amine); 4,4xe2x80x2-methyl-1-ethylidenebis-(benzene amine); 4,4xe2x80x2-trifluoro-methyl-1-trifluoro-2,2,2-ethylidenebis-(benzene amine); 3,3xe2x80x2-phenylene-1,3-dioxybis-(benzene amine); 4,4xe2x80x2-phenylene-1,3-dioxybis-(benzene amine); 3,3xe2x80x2-phenylene-1,4-dioxybis-(benzene amine); 4,4xe2x80x2-phenylene-1,4-dioxybis-(benzene amine); 3,3xe2x80x2-diamino-benzanilide; 3,4-diamino-benzanilide; 4,4xe2x80x2-diamino-benzanilide; bis (amino-3-phenyl)-dimethylsilane; bis-(amino-4-phenyl)-dimethylsilane and 9-fluoro-ylidene-bisphenyl-amine.
Amongst the biprimary sulphonated diamines with formula (IV):
Where Ar2 has the signification already given above, and that one can use, within the scope of the preparation of polyamides according to the invention. One can cite, for example, 1,4-diaminobenzene-3-sulphonic acid, and 4,4xe2x80x2-diamino-1,1xe2x80x2-biphenyl-di-2,2xe2x80x2 sulphonic acid.
The condensation of dianhydrides with diamines can be carried out, within the scope of the invention, either with or without a chain limiting agent.
However, it is preferable to use a chain limiting agent, preferably an anhydride type, since by doing this one avoids the presence at the end of the polymer chain of an easily oxidisable amine group.
Amongst the anhydride type chain limiting agents that are suitable for preparing the polymers according to the invention, one can cite the functional anhydrides with the following formula (V):
where C3 has the signification already given above.
Examples of anhydrides with formula (V) are phthalic anhydrides and 3-fluorophthalic anhydride, naphthalene-1,8-dicarboxylic anhydride, etc.
In a second stage, the actual synthesis of the polyimide is carried out according to the following diagram given as an example of the first type of recurrent structure:
In the first stage of the preparation process for the polyimides according to the invention, one can dissolve the basic reagents in an appropriate solvent.
The solvent may be any appropriate solvent known by those skilled in the art as suitable for polycondensation reactions of dianhydrides with diamines.
In a preferred embodiment of the invention, the solvent is an aprotic polar solvent chosen, for example, from dimethylformamide, dimethylacetamide, N-methylpyrrolidone, either singly or as mixtures with, for example, aromatic solvents such as xylene or glycol ether type solvents.
The solvent may also be a phenolic type solvent, in other words, chosen, for example, from phenol, phenols substituted by one or several halogens (Cl, I, Br, F), creosols (o-, m- and p-cresol), cresols substituted by one or several halogens (Cl, I, Br, F), and mixtures of these solvents.
The preferred solvents are those comprising m-cresol and a mixture of para-chloro-phenol or meta-chloro-phenol and phenol, for example in the proportions of 20% phenol and 80% para- or meta-chloro-phenol.
Reagents are taken to mean compounds (II), (III), (IIxe2x80x2) (IV) and possibly (V), already described above. One may, for example, begin by reacting, as initial reagents present in the mixture, a dianhydride (II) and/or a dianhydride (IIxe2x80x2) with a sulphonated diamine (IV), then adding the second diamine (III).
All of the possible combinations concerning the order of addition of the reagents may easily be determined by those skilled in the art.
The first stage condensation reaction is carried out in solvent, generally at ordinary temperature, for example 20-25xc2x0 C., and it forms the intermediate polyamide-acid, or prepolymer.
The intermediate polyamide-acid obtained may be used, for example, to prepare a film, for example, by casting; the solvent is then evaporated at a temperature of 50 to 150xc2x0 C. in order to give a final polyamide acid, and the polyimide according to the invention is obtained in accordance with the second stage, either by thermal treatment at a temperature below 250xc2x0 C. (in other words, below the desulphonation temperature), or by chemical dehydration by using acetic anhydride.
Another preferred alternative consists in heating the initial solution containing, in the first instance, all of the reagents, to a temperature of, for example, 120 to 200xc2x0 C. for, for example, 6 to 72 hours.
The initial solution may, as has already been mentioned above, only contain in a second case, part of the reagents required for the preparation of the final polyimide, for example the initial mixture may only contain compounds (II) and/or (IIxe2x80x2), and (IV). In this case, the mixture is heated to a temperature of, for example, 120 to 200xc2x0 C. for, for example, 6 to 72 hours, then the mixture is allowed to cool to a temperature of, for example, 20 to 50xc2x0 C. and then the remainder of the reagents, for example compounds (III) and (II), are added.
The temperature of the mixture is then raised to, for example, 120 to 200xc2x0 C. for, for example, 6 to 72 hours.
In both cases, the heating causes the cyclisation of the amide acid into the imide and one obtains the polyimide, according to the invention, as the final product.
The polymerisation is stopped by cooling the solution, for example, to ambient temperature. The solution is then poured, preferably slowly, for example under very vigorous agitation, into a recipient containing, for example, methanol or ethanol.
The normally fibrous solid that precipitates is separated, for example, by filtration and is then preferably washed once or several times, for example with a sufficient quantity of, for example, methanol.
The polymer obtained is then dried, preferably at a temperature between 50 and 120xc2x0 C., for example, in a forced air oven for sufficient time.
The films or membranes comprising the sulphonated polyimide described above can be prepared by conventional methods, for example by casting, in other words, the polymer according to the invention is put into solution in a suitable solvent such as cresol, or N-methylpyrrolidone or phenol, then poured onto a flat surface such as a plate of glass, then dried in order to form a film with a thickness of, for example, 5 to 200xcexc.
In a particularly advantageous embodiment, the membranes, according to the process and device of the invention, have thicknesses considerably below those of membranes according to the prior art used in analogous semi-permeable processes and devices, and the thickness of the membranes will be preferably, according to the invention, be from 1 to 100xcexc and even more preferably 50 xcexc, although it is preferably 100 to 200xcexc, and even more preferably 200xcexc, in membranes according to the prior art. The specific properties conferred on the membranes by the specific polyimides of formula (I) according to the invention have been described above.
The lower thickness, with equivalent or even superior mechanical strength, leads to, for example, a lower ohmic drop and, as a result, better overall yield in the process.
In the same way, it is possible to considerably reduce the quantities of sulphonated polyimide used in the process and device according to the invention, by forming membranes in the form of porous polymer structures, for example, in PTFE (polytetrafluoroethylene) or in polyimide or even polypropylene, or porous structures obtained, for example, from glass or carbon cloth or matting, which provide the necessary mechanical strength and which are impregnated with the polymers according to the invention. Thanks to the excellent properties of the polymers according to the invention, one thus manages to reduce the thickness of the equivalent membrane and one minimises, as a consequence, the associated ohmic drops.
The process according to the invention may be chosen from all of the known separation processes that use semi-permeable membranes.
The process according to the invention is chosen, preferably, from semi-permeable membrane separation processes in which the separation is achieved under the action of an electrical field.
Amongst the semi-permeable membrane separation processes according to the invention one can cite, for example, dialysis, electro-dialysis, osmosis, reverse osmosis, electro-osmosis, electrolysis, and any other electrochemical process using a separating membrane between the anodic and cathodic compartments.
The process according to the invention allows, according to a particularly advantageous aspect, one to treat extremely acidic pH or very oxidising media.
By very acidic is generally meant media with a pH below 1.
The very acidic media treated are generally aqueous solutions of inorganic and/or organic acids, such as hydrochloric acid, nitric acid, sulphuric acid, hydrofluoric acid or a mixture of these acids at a concentration of, for example, 10xe2x88x925 to 10xe2x88x921 to mol/l.
The process according to the invention may be applied to the concentration in metals and/or salt and/or other compounds, such as acids, bases or others, of all types of media, for example, effluents and, in particular, aqueous effluents; the metals may be chosen, for example, from nickel, copper, silver, etc., the salts can be chosen, for example, from NaCl, MgSO4, CaSO4, CUCl2, CrCl2, ZnSO4, CuSO4, AgNO3, etc.
The process according to the invention may, in particular, be a sea water or brackish water desalination process.
In a more precise manner, and thanks to the unexpected permselectivity and selectivity properties of the membranes according to the invention, associated with their other properties, such as conductivity and resistance in acidic media, the process according to the invention will, notably, be a dialysis or electro-dialysis process applied to dialysis and electro-dialysis processes in areas such as the recovery of effluents containing metals, the desalination of sea water, the concentration of salt in sea water, the concentration of dilute solutions, etc.
The process according to the invention may also be an osmosis or electro-osmosis process that allows a substrate to be oxidised, such as an organic acid, or the dissolution of a metal oxide, by an electro-generated transmitter, such as an Ag II ion; this process is generally used in a very acidic medium, such as that described above.
The process according to the invention may also be a process for recovering metals, such as one of those cited above, by electrolysis.
The process according to the invention may also be a concentration process of any type of solution by electro-dialysis.
Finally, the process according to the invention may be any other electrochemical process, in which a separating membrane is used between an anode and a cathode.
The invention also concerns a device for the application of the process according to the invention, whereby such a device only essentially differs from devices of the prior art by the fact that one uses a specific membrane according to the invention, instead of and in place of the membranes used in devices of the prior art.
The structure of such devices is known in itself and only requires minimum adaptations in order to receive the membranes of the invention.
It should however be noted that, due to the excellent properties of the membranes according to the invention, linked notably to the excellent properties of sequenced polyimides with formula (I), the cost of such devices will be less, their size possibly reduced, their energy consumption reduced and their operational life extended.
Finally, the invention concerns the use of a membrane, as described above, in a semi-permeable membrane process or device.
The invention will now be described in more detail, using as references the attached diagrams, in which:

Separation method and device with semi-permeable membranes comprising sulphonated polyimides

Abstract: The present invention also relates to the use of sulphonated polyimide membranes in separation processes and devices using semi-permeable membranes. The said sulphonated polyimide comprises recurrent structures with the formula (In):

Abstract: and recurrent structures with the formula (Im):


The program for a control system can be created in a relatively short time, and a program that has been used in the past can be re-used. A user without specialist knowledge can change the operation and control of the controlled elements. These features are achieved by establishing a program which has standardized modes and mode transitions for each controlled element comprising a system to be controlled. A program for each controlled element is then created by starting with this standardized program and changing the parameters to suit each particular controlled element. If the operation and control of the controlled elements have to be altered, an operating chart which the user has written out is translated into a language which the control system can understand and the program is automatically altered.

The present invention claims priority from Japanese Patent Application No. 10-40638 filed Feb. 23, 1998, No. 10-101438 filed Apr. 13, 1998, and No. 10-146103 filed May 27, 1998, the contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a technique for standardizing computer programs used for control. It relates in particular to a technique for standardizing and thereby readily implementing the design, modification and major alteration of such computer programs.
The present invention further relates to a control program of a control system created by combining a plurality of control modules, each of which separately controls at least one of a plurality of controlled elements contained in a single controlled system, and control modules for hierarchically controlling these control modules.
2. Description of Related Art
When a plurality of controlled elements are provided in a single system, it is a widely practiced technique to provide a plurality of control modules for controlling these controlled elements, and to connect these control modules hierarchically so that each of a plurality of first-level control modules controls at least one controlled element, second-level control modules control first-level control modules, and so on, whereby the system as a whole is controlled.
FIG. 2 is a control system diagram schematically representing a single system, and is applicable to both the prior art and embodiments of the present invention. The system depicted in FIG. 2 comprises a plurality n of controlled elements E(1)-E(n) and has the following hierarchical structure. Namely, control module M(1) controls controlled elements E(1)-E(3). Control module M(2) controls controlled elements E(4), E(5), . . . . Control module M(k) controls controlled elements E(i)-E(n). Control module M(k+1) controls control modules M(1) and M(2), and control module M(k+2) controls a plurality of control modules up to control module M(k). Control module M(k+3) controls these two control modules M(k+1) and M(k+2).
A communications memory COMA is provided and each control module M(1)-M(k+3) is configured so that it can access this communications memory COMA by means of a corresponding communications line C(1)-C(k+3). Each control module M(1)-M(k+3) is configured so that at prescribed intervals it accesses communications memory COMA and reads communications addressed to itself that have been written in an allocated region of the communications memory, and if necessary writes communications addressed to another module in a region of the communications memory which has been allocated to that other module.
This will be explained by way of an illustration in order to make it easier to understand. On the assumption that this system is a semiconductor fabrication system, then controlled element E(1) might be the vacuum pump of a first vacuum chamber, controlled element E(2) the elevator inside this first vacuum chamber, and controlled element E(3) the pressure valve of the first vacuum chamber. Controlled element E(4) might be the vacuum pump for a chamber connecting with a second vacuum chamber, and controlled element E(5) might be the transfer belt of this connecting chamber. Controlled element E(i) might be a product exit door, controlled element E(nxe2x88x921) a product exit elevator, and controlled element E(n) a product exit transfer apparatus.
These controlled elements E(1)-E(n) are under the overall control of control module M(k+3) and are hierarchically controlled by control modules M(1)-M(k+2), whereby a continuous series of semiconductor fabrication steps is carried out. Namely, silicon wafers are transferred into the first vacuum chamber and set in a prescribed position, the degree of vacuum is increased by operation of the vacuum pump, and deposition is carried out. Finally, the product (or semi-finished product) is transferred to the product exit.
Each controlled element has a sensor, and information output from this sensor is sent to the control module which controls the controlled element. Each control module performs servo-control in accordance with the information output from this sensor. Information relating to other control modules is transmitted to and from the other control modules via communications memory COMA.
The present inventor has been working for a long time on the design of control programs for control systems of the sort illustrated in FIG. 2, where a plurality of control modules control a plurality of controlled elements. Controlled elements E(1)-E(n) may be valves, the switches of motors, or rotating shafts of robot devices. Control modules with different specifications have therefore hitherto been utilized to suit different types of controlled element.
Namely, when designing a control program for a control system of this sort it has been necessary to design control modules which were appropriate to the properties and characteristics of the respective controlled elements E(1)-E(n). This has meant that the design of a control program for a control system has taken a large number of man-hours. It has also meant that each time a specification change or modification becomes necessary, it takes a large number of man-hours to change the control program of the control modules. That is to say, if a design change is required for one of the hierarchically combined control modules, this design change will impact on both higher-level control modules and lower-level control modules, so that a large number of control modules have had to have design changes.
Moreover, even if the controlled elements comprising a new controlled system include controlled elements that were used in the past, the designer has to grasp the overall operation of the new controlled system all over again and create a program with reference to the whole series of operations from initial step to final step. Consequently, if a past design is appropriated, the program for the higher-order and lower-order control modules of the new system has to be changed to fit the past design. Accordingly, even if parts of the program for the controlled elements that were used in the past can be transferred to and used in the program for the new controlled system, as a rule the scope for such transfer has been extremely limited.
It is accordingly an object of the present invention to provide a program control system and a method of creating a control program thereof, capable of utilizing, without modification, important portions of the program of a previously designed control module. It is a further object of the present invention to provide a control system and a method of creating a control program thereof, capable of considerably reducing the man-hours required to create a control program of a control system comprising a combination of control modules. It is another object of the present invention to provide a control system and a method of creating a control program thereof, capable of rationalizing the process of creating a control program. It is yet another object of the present invention to provide a control system and a method of creating a control program thereof, capable of incorporating the program of previously designed control modules with only slight changes, despite the devices to be controlled and the controlled elements being different. It is a further object of the present invention to provide a control system and a method of creating a control program thereof whereby a small number of man-hours is sufficient to adjust to changes or modifications which have occurred in controlled elements or control conditions. It is yet another object of the present invention to provide a control system and a method of creating a control program thereof whereby a general user without specialist knowledge can deal with changes or modifications which have occurred in controlled elements or control conditions.
A first feature of the present invention is that, in a control system for controlling a single system, the control module modes and mode transitions are standardized for all the control modules. Even if a mode of the basic module is not used in a certain control module, that mode is still provided in accordance with the basic module. It is also ensured that the modes and mode transitions are restricted to those provided in the basic module. If there is a need to extend the modes and mode transitions available, another basic module is designed. All the control module modes and mode transitions are standardized in at least one closed system. All sorts of control modes can be designed by setting parameters for these modes and mode transitions in accordance with the conditions imposed by the control conditions and controlled elements.
Namely, in a first aspect, the present invention is a control system for controlling a single controlled system comprising a plurality of controlled elements, said control system comprising a plurality of control modules and communication means for communicating between these plurality of control modules; wherein the plurality of control modules are connected in an hierarchical structure so that the lowest level control modules each control at least one of the aforesaid plurality of controlled elements, and the control modules of one level are controlled by the control modules of the immediately higher level; and the modes and mode transitions of each of the aforesaid plurality of control modules are mutually standardized. The distinguishing feature of the invention in this aspect is that the modes and mode transitions of the plurality of control modules are standardized.
Each of the aforesaid plurality of control modules preferably has specific sequence data tables in which are recorded, on the basis of instructions from an hierarchically higher-level control module, the procedures for controlling the aforesaid plurality of controlled elements, and an interpretive control means which controls the aforesaid controlled elements by referring to these sequence data tables. The sequence data tables can preferably be modified by access from a terminal device when an aforesaid control module is not operating.
The sequence data tables are recorded using an intermediate language which an expert can understand, and the control system preferably has translation means for automatically translating, into the format of the sequence data tables, an ordinary language based expression which is input to the aforesaid terminal device and which even a user without specialist knowledge can understand.
This enables the user of a control system according to the present invention to rewrite, by himself, the actions of its controlled elements. That is to say, a general user without specialist knowledge can deal with situations in which the controlled elements or control conditions have changed or been modified.
The aforesaid ordinary language based expression can be a flowchart, a timing chart, or a sequence table.
The translation means preferably includes indication means which, if the aforesaid ordinary language based expression that has been input to the terminal device is inadequate and cannot be translated, prompts for re-input to the terminal device.
User data in a form suitable for a control system according to this invention can thus be obtained by interaction with the user. This interaction enables the user to provide the control system with optimum user data, since even a user without specialist knowledge can discover, by interaction with the control system, whether he has input too much or too little data.
The aforementioned modes and mode transitions of the control modules comprise: a start mode for controlling the starting of the corresponding controlled elements; a normal operation mode to which direct transition can be made from the start mode, and which controls the normal operation of said controlled elements; a stop mode to and from which mutual direct transitions can be made from and to the normal operation mode, said stop mode controlling the stopping of said controlled elements; a hold mode to and from which mutual direct transitions can be made from and to the stop mode, and from which direct transition can be made to the aforementioned start mode, said hold mode controlling the aforementioned controlled elements in a hold state; a reverse mode to which direct transition can be made from the hold mode, and to and from which mutual direct transitions can be made from and to the aforementioned stop mode, said reverse mode controlling the reversing of the aforementioned controlled elements; a manual control mode to which direct transition can be made from the hold mode, and to and from which mutual direct transitions can be made from and to the stop mode, and from which transitions can be made to the normal operation mode or the start mode, said manual control mode being used for manual control of the aforementioned controlled elements; an alarm mode to which transition can be made from any of the aforesaid modes, and which generates an alarm; an exceptional operation mode to which transition can be made from any of the aforesaid modes, and which temporarily causes at least some of the aforesaid control modules to operate out-of-step from the other control modules; and an end mode to which direct transition can be made from the aforesaid hold mode, and which terminates the control of the controlled elements.
The aforesaid start mode comprises a cold start mode which creates a control file, and a hot start mode to which a transition is made from the cold start mode, and which writes the file data to RAM.
The aforesaid normal operation mode comprises an origin mode which confirms that the controlled elements are at their starting point, a restoration mode which restores a sequence of events of automatically operating controlled elements to the state just before the sequence was interrupted, a preparation mode which prepares for automatic operation of the controlled elements, and a running mode for automatically operating the controlled elements.
The aforesaid stop mode comprises an emergency stop mode for urgently stopping the operation of the controlled elements, a decelerating stop mode which gradually stops the operation of the controlled elements, and a stepped stopping mode which temporarily stops the operation of the controlled elements at each operating step in their event sequence.
The aforesaid hold mode comprises a CPU stop mode capable of stopping the CPU, a control release mode which releases the controlled elements from control, a control restore mode which returns the released controlled elements to control, and a diagnostic mode which can convert the operating state of the controlled elements to data and can change the control specification.
The aforesaid alarm mode comprises an abnormal stop mode which stops the operation of a controlled element when an abnormality has been detected in its operation, and an emergency stop mode which performs an emergency stop in accordance with external directions, irrespective of the operating state.
In a second aspect, the present invention is a method of programming the aforesaid control system, comprising steps of duplicating the basic module, for which modes and mode transitions have been established, a plural number of times; creating a plurality of control modules corresponding to the various control specifications by editing each of the duplicated basic modules while maintaining the mode and mode transitions of the basic module, and creating a control program for a single system by hierarchically combining these plurality of control modules.
The aforementioned modes and mode transitions of the aforesaid basic module comprise: a start mode for controlling the starting of the corresponding controlled elements; a normal operation mode to which direct transition can be made from the start mode, and which controls the normal operation of said controlled elements; a stop mode to and from which mutual direct transitions can be made from and to the normal operation mode, and which controls the stopping of said controlled elements; a hold mode to and from which mutual direct transitions can be made from and to the stop mode, and from which direct transition can be made to the aforementioned start mode, said hold mode controlling the aforementioned controlled elements in a hold state; a reverse mode to which direct transition can be made from the hold mode, and to and from which mutual direct transitions can be made from and to the aforementioned stop mode, said reverse mode controlling the reversing of the aforementioned controlled elements; a manual control mode to which direct transition can be made from the hold mode, and to and from which mutual direct transitions can be made from and to the stop mode, and from which transitions can be made to the normal operation mode or the start mode, said manual control mode being used for manual control of the aforementioned controlled elements; an alarm mode to which transition can be made from any of the aforesaid modes, and which generates an alarm; an exceptional operation mode to which transition can be made from any of the aforesaid modes, and which temporarily causes at least some of the aforesaid control modules to operate out-of-step from the other control modules; and an end mode to which direct transition can be made from the aforesaid hold mode, and which terminates the control of the controlled elements.
In a third aspect, the present invention is a machine readable recording medium. A distinguishing feature of this aspect of the invention is that a control program for control modules is created by setting numerical values in standardized programs, which are then recorded on the machine readable recording medium, wherein each control module comprises: a start mode for controlling the starting of the corresponding controlled elements; a normal operation mode to which direct transition can be made from the start mode, and which controls the normal operation of said controlled elements; a stop mode to and from which mutual direct transitions can be made from and to the normal operation mode, and which controls the stopping of said controlled elements; a hold mode to and from which mutual direct transitions can be made from and to the stop mode, and from which direct transition can be made to the aforementioned start mode, said hold mode controlling the aforementioned controlled elements in a hold state; a reverse mode to which direct transition can be made from the hold mode, and to and from which mutual direct transitions can be made from and to the aforementioned stop mode, said reverse mode controlling the reversing of the aforementioned controlled elements; a manual control mode to which direct transition can be made from the hold mode, and to and from which mutual direct transitions can be made from and to the stop mode, and from which transitions can be made to the normal operation mode or the start mode, said manual control mode being used for manual control of the aforementioned controlled elements; an alarm mode to which transition can be made from any of the aforesaid modes, and which generates an alarm; an exceptional operation mode to which transition can be made from any of the aforesaid modes, and which temporarily causes at least some of the aforesaid control modules to operate out-of-step from the other control modules; and an end mode to which direct transition can be made from the aforesaid hold mode, and which terminates the control of the controlled elements.
As has been explained above, according to the present invention, because the control modules are utilized after being standardized on the basis of a basic module, important portions of the program of previously designed control modules can be utilized without modification. The man-hours required to create a control program of a control system comprising a combination of control modules can therefore be considerably reduced. The present invention can rationalize the process of creating a control program. It can also incorporate the program of a previously designed control module with only slight changes, despite the devices to be controlled and the controlled elements being different. In addition, according to this invention a small number of man-hours is sufficient to adjust to changes or modifications which have occurred in the controlled elements or control conditions. Further, a general user without specialist knowledge can deal with changes or modifications which have occurred in controlled elements or control conditions.


The present invention is directed to a card member for receiving a tissue specimen to be processed for histological examination including an absorbent portion for maintaining the tissue specimen in engageable contact with the card member, and a generally non-adhesive portion for allowing separation of the tissue specimen from the card member, where the card member provides the specimen with a known, consistent orientation throughout processing.

It is a standard procedure to prepare tissue samples for microscopic examination by embedding the tissue in paraffin and slicing the paraffin-embedded tissue very thinly with a microtome. Preparatory to embedding, the tissue is treated in various solutions appropriate to its examination and long-term stability. Typically, prior to paraffin embedding, the tissue sample is fixed, dehydrated, and cleared and then infiltrated with molten paraffin.
Typically, the tissue sample collected for examination is a unitary, connected portion of tissue, however, small parts of the tissue sample may be dislocated during tissue processing. Alternatively, a biopsy may be performed on minute fragments less than 1.0 mm in diameter, such as bronchial washings, cytology preparations and aspiration biopsies which may be gathered by skinny needles or imaging technology-guided tissue biopsy devises. Generally, this technique is called "tissue processing," and it includes the following: (1) collection of the specimen; (2) fixation of the specimen to preserve tissue components; (3) sampling of a representative portion or aliquot; and (4) cutting of the non-processed tissue in a section plane to be presented to the microtome blade (for microscopic examination and information collection) and placement of this plane face down in a tissue processing cassette for containment during the "tissue processing phase."
Information obtained in the microscopic study of biological tissue is taken from microtome cut sections that, on average, are less than 10 μthick. Thus, in view of the small size of the tissue sample and the precision with which the microtome cut sections are cut, it is of paramount importance to select a cutting plane and to maintain this plane as closely as possible, if not exactly, during processing, embedding and sectioning. Further, in the instance of minute specimens (approximately 1 mm or less), it may also be desirable to preserve the orientation of the tissue sample in relation to the adjacent structures from which it was collected. Such information may provide guidance for surgical or other treatments.
Tissue placed in a processing cassette may be fresh or fixed. The tissue sample is then passed through fixatives to remove water from the sample. Following dehydration, the tissue sample is then processed with a solvent that will dissolve fatty materials and "clear" the tissue sample. After being "cleared", the tissue sample is placed in molten paraffin and it is infiltrated with the wax. Molten wax replaces the solvent which will evaporate or be diluted to trace levels, causing all the tissue to be infiltrated with a common wax binder.
Next, the cassette is opened and the infiltrated tissue is placed into a metal or similar base mold filled with melted wax. A considerable effort must be made at this moment to cause the "face down" selected cutting plane of the tissue to be positioned in the exact same planar relationship that was selected by the doctor or technician who placed the sample and selected the portion of the tissue that would be cut in microtomy. It is critical in many examinations, such as cancer diagnosis, to maintain the parallel relationships of: (a) selected cutting surface; (b) microtomy cut surface; (c) glass slide stained and covered cut section; and (d) microscopic section orientation for examination.
The technician thus must attempt to present the specimen to the microtome cutting blade in the exact position previously selected. The technician prepares the specimen for microscopic examination by subsequently mounting, staining and cover-slipping the microtome cut section on a microscope slide. Although it is desirable to maintain the positioning of the specimen, it is very difficult to control the position of the specimen particularly with minute tissue samples. A small (0.25-1.0 mm) specimen may likely shift its position in the cassette during processing or when it is removed from the processing cassette to the embedding mold prior to wax casting, so that the pre-selected position of the specimen may be lost.
Apparatuses are known that may be used for processing of tissue samples, such as described in U.S. Pat. Nos. 4,557,903 and 4,569,647, both to McCormick. In both the '903 and '647 patents, the tissue sample is deposited somewhat randomly in the cassette. It is a limitation that, although the tissue sample is disposed in an enclosed area, it may move freely within that area as the tissue sample is contacted with solvents during processing. Additionally, the apparatus of the '903 patent requires removing the tissue sample from the cassette and placing it in a mold for casting in paraffin. A shortcoming of the '903 and '647 patents is their inability to maintain the tissue sample in a desired orientation throughout processing.
There remains a need for an apparatus and processing method that permits the tissue plane selected by the surgeon or pathologist to be processed in situ without disturbing the orientation of the tissue specimen. More particularly, there is a need for an assembly and method that maintains the desired position of the tissue sample during the fixing, processing, and wax embedding steps, as well as during subsequent sectioning in a microtome and mounting of the desired section on a glass slide for staining, cover-slipping and microscopic examination. Such a system should be adaptable for both large specimen sections and minute fragments of less than 1 mm in size.

Card member for receiving a tissue specimen to be processed for histological examination


A vehicle seat is disclosed which comprises a seat cushion (1), first and second seat backs (2, 3) separated from each other in a vehicle width direction and pivotally supported to the seat cushion (1), a first recliner device (22) for allowing the first seat back (2) to be pivoted in a forward/rearward direction with respect to the seat cushion (1), and a second recliner device (34) for allowing the second seat back (3) to be pivoted in the forward/rearward direction with respect to the seat cushion (1).

Generally, in a vehicle such as a wagon car, a three-passenger seat which includes a center seat section provided between left and right seat sections is installed as a rear seat such as a second seat or a third seat. In this three-passenger seat, the respective seat sections are formed independently from one another, provided with recliner devices, and configured so as to be pivotable forward and rearward through the recliner devices (Japanese Patent Application Laid-Open Nos. 2001-301496 and 2001-310667).
When the seat sections of the three-passenger seat are formed independently from one another, the recliner devices are required to be provided at both sides of each of the seat sections and brackets between which the recliner devices are arranged interposedly are also required to be provided at seat cushions and seat backs of the three-passenger seat, so that an effective sitting-space for a passenger in each seat section which is measured in a vehicle width direction is inevitably made relatively narrow.
In lieu of the related art seat which has been discussed above, there may be proposed a vehicle seat which includes a single seat cushion and two seat backs separated from each other in a vehicle width direction and supported to the single seat cushion through recliner devices so as to be independently pivotable forward and rearward with respect to the seat cushion.
Even in the case where the two seat backs are supported to the single seat cushion so as to be independently pivotable, when the recliner devices are provided at both sides of each seat back, brackets between which the recliner devices are arranged interposedly are required to be provided at the seat cushion and the seat backs, so that effective sitting-spaces for passengers which are enough in the vehicle width direction cannot be obtained.


An electrical connection assembly includes a first connector which includes a first electrical contact surrounded by a first connector wall defining a first connector cavity. The first connector wall includes a plurality of ribs extending into the first connector cavity. A second connector is matable with the first connector along a mating axis and includes a second electrical contact in electrical communication with the first electrical contact when the first connector is mated with the second connector. The second connector includes a second connector body surrounding the second electrical contact.

There are applications where a high-voltage, high-current, large device connection system may require a finger test probe certification that indicates that a test probe, when inserted into a section of a connector half of the device connection system, is prevented from making electrical contact with an electrical terminal disposed therein. The finger test certification is desired so that, for example, if the connection system is employed in an electric or hybrid electric vehicle, a human operator's finger, if making contact with connection system, does not make contact with the electrical contact of the device connection system.
One related connection system is a complex, moving part connection system 100, as shown in FIGS. 1 and 2. Connection system 100 generally includes a first connector half 102 having a first electrical terminal 104 and a second connector half 106 having a second electrical terminal 108. First connector half 102 employs a protective piece 110 that is moveable between a protective position as shown in FIG. 1 when the first connector half 102 is not mated with second connector half 106 to a non-interfering position as shown in FIG. 2 when first connector half 102 is mated with second connector half 106. As shown in FIG. 1, protective piece 110 is locked in the protective position when first connector half 102 is not mated with second connector half 106. Thus, protective piece 110 prevents a finger of a user from coming into contact with first electrical terminal 104. As shown in FIG. 2, mating of first connector half 102 with second connector half 106 unlocks protective piece 110 from the protective position and allows protective piece 110 to move upward into the non-interfering position. Movement of protective piece 110 upward allows first electrical terminal 104 to make electrical contact with second electrical terminal 108. Conversely, when first connector half 102 is unmated from second connector half 106, protective piece 110 moves downward and locks into the protective position. Connection system 100 is tightly toleranced in order to allow protective piece 110 to move between the protective position and the non-interfering position. The tight tolerances required of connection system 100 may lead to increased manufacturing costs.
What is needed is an electrical connection system which minimizes or eliminates one or more of the shortcomings as set forth above.


A thermoelectric power generation system of the present disclosure includes first and second thermoelectric power generation units. Each of the thermoelectric power generation units includes a plurality of tubular thermoelectric generators. The first and second thermoelectric power generation units are electrically connected to each other such that a first impedance caused by the tubular thermoelectric generator included in the first thermoelectric power generation unit is matched with a second impedance caused by the tubular thermoelectric generator included in the second thermoelectric power generation unit.

1. Field of the Invention
The present disclosure relates to a thermoelectric power generation unit provided with a thermoelectric conversion element converting heat into power. The present disclosure also relates to a thermoelectric power generation system provided with a plurality of thermoelectric power generation units.
2. Description of the Related Art
The thermoelectric conversion element can convert the heat into the power or convert the power into the heat. The thermoelectric conversion element made of a thermoelectric material exerting a Seebeck effect can acquire thermal energy from a heat source having relatively low temperature (for example, 200° C. or less) to convert the heat into the power. The thermal energy that is conventionally abandoned into a surrounding environment in a state of vapor, hot water, or emission gas can be recovered and effectively used in a thermoelectric power generation technology in which the thermoelectric conversion element is used.
Hereinafter, the thermoelectric conversion element made of the thermoelectric material is referred to as a "thermoelectric generator". A general thermoelectric generator has what is called a "t-type structure" in which a p-type semiconductor and an n-type semiconductor, in which electric poralities of carriers are different from each other, are combined (for example, see Unexamined Japanese Patent Publication No. 2013-016685). In the thermoelectric generator having the "π-type structure", the p-type semiconductor and the n-type semiconductor are electrically connected in series, and thermally connected in parallel. In the "π-type structure", a thermal flow direction and a current flow direction are parallel or anti-parallel to each other. For this reason, it is necessary to provide an output terminal in an electrode on a high-temperature heat source side or a low-temperature heat source side. Accordingly, a wiring structure becomes complicated in order to electrically connect a plurality of thermoelectric generators having the "π-type structure" in series.
International Patent Publication No. 2008/056466 discloses a thermoelectric generator including a stacked body in which bismuth layers and metallic layers made of metal except bismuth are alternately stacked between a first electrode and a second electrode. The first electrode and the second electrode are opposed to each other. In the thermoelectric generator disclosed in International Patent Publication No. 2008/056466, a stacking plane is tilted with respect to a direction of a straight line connecting the first electrode and the second electrode. Tube-type thermoelectric generators are disclosed in International Patent Publication No. 2012/014366, Kanno et al., Proceedings of the 72nd JSAP Autumn Meeting, 30a-A-14 "Tubular power generator via off-diagonal thermoelectric effect" (2011), and A. Sakai et al., International conference on thermoelectrics 2012, 328 "Enhancement in performance of the tubular thermoelectric generator (TTEG)" (2012).

Thermal power generation unit and thermoelectric power generation system


Embodiments of the present invention provide a receiver and a receiving method. The receiver comprises: a branch forming unit a plurality of signal branches; each of the signal branches comprising a joint processing unit; and the joint processing unit being used to eliminate an inter-carrier interference of the subcarrier signal in a present signal branch and the subcarrier signals in other signal branches adjacent to the present signal branch. With the embodiments of the present invention, the inter-carrier interference may be eliminated and the performance of the system may be improved; and the sampling rate of the analog digital converter may also be lowered.

In order to improve the capacity and spectrum usage rate of optical communications, coherent OFDM has attracted the interests of the researchers recently. An OFDM superchannel comprises a plurality of optical carriers, each of the optical carriers individually being modulated, forming several sub-channels, with these sub-channels jointly constituting a superchannel. Each of the optical carriers may use a high-level modulation format (such as QPSK).
In such a system, an interval between subcarriers equals to a baud rate, and severe overlapping exists in the spectrum of each of the sub-channels; however, due to the orthogonality between them, theoretically, each of the sub-channels can still be demodulated and does not interfere with each other. At a receiving side, after being frequency mixed with a local oscillator laser, an optical signal is converted into an electrical signal by an optoelectric detector, and after analog-digital conversion, the electrical signal is subjected to a series of digital signal processing (DSP). DSP comprises subcarrier separation, adaptive equalization, frequency offset compensation, phase recovery etc., and compensates for such effects as transmission damage, frequency offset, line width, etc., and finally recovers the transmitted data. The DSP technique used in a receiver is one of the key techniques of the superchannel. A method reported in an existing document is to use a plurality of local oscillator lasers to target at different subcarriers respectively, so as to receive the subcarriers, and individually perform DSP processing on each of the received subcarriers to demodulate the data.
FIG. 1 is a schematic diagram of the structure of a superchannel receiver of the prior art. As shown in FIG. 1, the receiver divides a signal into multiple paths by using a coupler after receiving the signal from a transmitter. As shown in FIG. 1, a signal branch corresponding to a path of signal may comprise a front end processing device 101 and a signal compensating device 102. Wherein, the front end processing device 101 may comprise a local oscillator (LO) laser 1011, a mixer (HB) 1012, an anti-aliasing filter (AAF) 1013, an analog digital converter (ADC) 1014, a captive dispersion compensator (CDC) 1015 and an adaptive equalizer (AEQ) 1016. And the signal compensating device 102 may comprise a frequency offset compensator (FOC) 1021, a carrier phase recoverer (CPR) 1022 and a data recoverer (DR) 1023.
As shown in FIG. 1, each path of signal may correspond to a local oscillator laser 1011. In a practical system, a plurality of local oscillator lasers may come from an independent laser, and may also come from a multicarrier light source (in non-patent document 1), or a mode-locked laser, etc. In general, it may be a certain laser source containing a plurality of discrete wavelengths.
As shown in FIG. 1, a superchannel optical signal is respectively mixed with local oscillator lasers with different wavelengths, and may be converted into a baseband electrical signal by an optoelectric detector in the mixer 1012. When only one subcarrier is demodulated in each time of sampling, a plurality of local oscillator light sources respectively target to frequencies of a plurality of subcarriers. And then the electrical signals are converted to a digital domain after being sampled by the anti-aliasing filter 1013 and the analog digital converter 1014, and are subsequently subjected to a series of digital signal processing.
Wherein, the captive dispersion compensator 1015 is configured to compensate for the accumulated dispersion after long-haul optical fiber transmission; the adaptive equalizer 1016 is configured to compensate for residual dispersion, polarization mode dispersion and other dynamic linear damages; the frequency offset compensator 1021 is configured to compensate for the frequency offsets of the lasers at the transmitting side and the receiving side; the carrier phase recoverer 1022 is configured to compensate for the phase noise of the lasers at the transmitting side and the receiving side; and the data recoverer 1023 is configured to recover the transmitted data. FIG. 1 shows the case where only one subcarrier is demodulated in each time of sampling, and multiple subcarriers may also be demodulated in each time of sampling.
FIG. 2 is another schematic diagram of the structure of a superchannel receiver of the prior art. As shown in FIG. 2, the front end processing device 201 further comprises a subcarrier separator (SCS) 2010, by which an input signal is separated into two carriers. However, it is not limited thereto, and the input signal may be separated into more carriers, and the numbers of the carriers separated by the subcarrier separators may be identical or different. The number of carriers separated by the subcarrier separator of each branch depend on the system design, and how many branches the whole superchannel is separated into for reception and how many carriers in each branch in which data are recovered should be specified in the system design.
In the implementation of the present invention, the inventors found that the cost of the code error rate can only be lowered to an acceptable level when the sampling rate is very high. As the baud rate of an optical sub-channel is relatively high (at a magnitude of 10 GHz), the sampling rate of an existing analog digital converter cannot satisfy such a requirement. Hence, simple use of methods in which sampling rate is increased is greatly restricted.
In the prior art, digital signal processing on subcarriers is performed independently. Such a method of independently processing subcarriers is at a certain cost of code error rate, and such independent processing cannot eliminate the interference between the subcarriers, and the performance of the system is hence affected.
Non-patent document 1: Benyuan Zhu et al, Ultra-long-haul transmission of 1.2 Tb/s multicarrier no-guard-interval CO-OFDM superchannel using ultra-large-area fiber, Photonics Technology Letters, vol. 22, no. 11, p. 826, 2010;
Non-patent document 2: S. Chandrasekhar et al, Terabit superchannels for high spectral efficiency transmission, ECOC 2010, Tu.3.C.5;
Non-patent document 3: S. Chandrasekhar et al, Experimental investigation on the performance of closely spaced multi-carrier PDM-QPSK with digital coherent detection, Optics Express, vol. 17, no. 24, p. 21350, 2009; and
Non-patent document 4: S. J. Savory et al, Transmission of 42.8 Gb/s polarization multiplexed NRZ-QPSK over 6400 km of standard fiber with no optical dispersion compensation. OTuA1, OFC 2007.