Racemic amino derivatives of the formula

The present invention relates to a new process for preparing racemic amino derivatives by racemization of optically active amides.
Already known is the preparation of optically active amides by enantioselectively acylating racemic amines and separating the resulting mixture of optically active amine and optically active amide (=acylated amine) (cf. DE-A 43 32 738, Chimia 48, 570 (1994)). Furthermore, it is already known that optically active amides can be obtained by enantioselective hydrolysis of racemic amides and subsequent separation of the resulting mixture of optically active amide and optically active amine (cf. EP-A 0 399 589). In order to make these processes for resolution of racemates economical, the undesired enantiomer in each case has to be racemized again and returned to the circuit. If the component which is not required is an optically active amine, the racemization can be carried out by treatment with alkoxides in the presence of dimethyl sulphoxide (cf. DE-A 40 38 356). However, if the undesired isomer is an amide, a disadvantage of the work-up is that a saponification of the optically active amide is first required and the racemization of the optically active amine formed can only be carried out in a further step.
It has now been found that racemic amino derivatives of the formula
in which
n represents the numbers 0, 1 or 2,
R1 represents unsubstituted or substituted alkyl, unsubstituted or substituted cycloalkyl, unsubstituted or substituted cycloalkenyl, unsubstituted or substituted aryl or unsubstituted or substituted heterocyclyl,
R2 represents unsubstituted or substituted alkyl, unsubstituted or substituted cycloalkyl, unsubstituted or substituted cycloalkenyl, unsubstituted or substituted aryl or unsubstituted or substituted heterocyclyl, but with R1 and R2xe2x80x94(CH2)nxe2x80x94 not being identical, and
R represents hydrogen or xe2x80x94COxe2x80x94R3, where
R3 represents hydrogen, amino, unsubstituted or substituted alkyl or unsubstituted or substituted alkoxy, with the carbon chain being able, in the case of those radicals containing more than one carbon atom, to be interrupted by heteroatoms or hetero groups, or
R3 represents unsubstituted or substituted cycloalkyl, unsubstituted or substituted cycloalkenyl, unsubstituted or substituted aryl or unsubstituted or substituted heterocyclyl,
are obtained when optically active amides of the formula
in which
R1,R2,R3 and n are as defined above,
are reacted with strong bases, optionally in the presence of an organic diluent and, if desired, the resulting racemic amides of the formula
in which
R1, R2, R3 and n are as defined above,
are reacted either
a) with water in the presence of a base or an acid and optionally in the presence of an organic diluent,
or
b) if the compounds of the formula (Ia) are amides in which R3 is hydrogen, with alkali metal hydroxide or alkaline earth metal hydroxide.
It must be regarded as extremely surprising that racemic amides and amines can be prepared by the process of the invention, since it was not previously known from the prior art that racemization of optically active amides is possible without prior saponification.
The process of the invention has a series of advantages. Thus, it makes possible the preparation of racemic amides or amines from the respective undesired enantiomers in high yield. It is also advantageous that the optically active amides required as starting materials can be obtained in a simple manner and that the acyl radical can be varied within a wide range. Finally, the reaction procedure and the isolation of the desired substances also present no difficulties at all.
Alkyl represents, in the present case, unless otherwise defined, saturated aliphatic hydrocarbon radicals which can be straight-chain or branched.
Cycloalkyl represents, in the present case, unless otherwise defined, saturated, carbocyclic radicals which may optionally, together with further condensed-on or bridged rings, form a bicyclic or polycyclic ring system.
Cycloalkenyl represents, in the present case, unless otherwise defined, unsaturated, carbocyclic radicals which may optionally, together with further condensed-on or bridged rings, form a bicyclic or polycyclic ring system.
Aryl represents, in the present case, unless otherwise defined, aromatic, monocyclic, bicyclic or polycyclic hydrocarbon radicals such as phenyl, naphthyl, anthryl, phenanthryl, preferably phenyl or naphthyl, in particular phenyl.
Heterocyclyl represents, in the present case, unless otherwise defined, saturated or unsaturated, cyclic radicals in which at least one ring atom is a heteroatom, i.e. an atom different from carbon. If the ring contains a plurality of heteroatoms, these can be identical or different. Heteroatoms are preferably oxygen, nitrogen or sulphur. Optionally, the cyclic radicals together with further carbocyclic or heterocyclic, condensed-on or bridged rings, form a bicyclic or polycyclic ring system. Preference is given to monocyclic or bicyclic ring systems, in particular monocyclic or bicyclic ring systems having aromatic character.
In the definitions, the saturated or unsaturated carbon chains such as alkyl, alkanediyl, alkenyl or alkinyl, including those linked to groups bonded by heteroatoms, i.e. groups such as alkoxy, alkylthio or alkylamino are in each case straight-chain or branched.
Halogen represents, in the present case, unless otherwise defined, fluorine, chlorine, bromine or iodine, preferably fluorine, chlorine or bromine, in particular fluorine or chlorine.
If (S)-N-[1-(4-chlorophenyl)-ethyl]-acetamide is used as starting material and potassium hydroxide as strong base, then the course of the first stage of the process of the invention can be depicted by the following reaction scheme:
If racemic N-[1-(4-chlorophenyl)-ethyl]-acetamide is used as starting component and aqueous hydrochloric acid as reaction component, then the course of the second stage of the process of the invention can be depicted by the following reaction scheme:
The optically active amides required as starting materials for carrying out the process of the invention are generally defined by the formula (II). In this formula, the asymmetrically-substituted carbon atom is denoted by (*). In other formulae for optically active compounds, centres of chirality are also each marked in the same manner.
n also preferably represents the numbers 0, 1 or 2.
R1 preferably represents straight-chain or branched alkyl having from 1 to 8 carbon atoms, with the alkyl radicals being able to be monosubstituted or polysubstituted, identically or differently, by halogen, amino, hydroxy, formyl, carboxy, carbamoyl, straight-chain or branched alkoxy or straight-chain or branched alkylthio each having from 1 to 6 carbon atoms;
and/or by straight-chain or branched halogenoalkoxy or straight-chain or branched halogenoalkylthio each having from 1 to 6 carbon atoms and from 1 to 13 identical or different halogen atoms;
and/or by alkylamino, dialkylamino, alkylcarbonyl, alkylcarbonyloxy, alkoxycarbonyl, alkylsulphonyloxy, hydroximinoalkyl or alkoximinoalkyl which may each be straight-chain or branched and each have from 1 to 6 carbon atoms in the individual alkyl parts;
or by doubly linked alkylene having from 1 to 6 carbon atoms, or by doubly linked dioxyalkylene having from 1 to 4 carbon atoms, with the two latter radicals themselves being able to be monosubstituted or polysubstituted, identically or differently, by halogen, straight-chain or branched alkyl having from 1 to 4 carbon atoms and/or straight-chain or branched halogenoalkyl having from 1 to 4 carbon atoms and from 1 to 9 identical or different halogen atoms, or
R1 preferably represents cycloalkyl having from 3 to 7 carbon atoms, with these radicals being able to be monosubstituted to tetrasubstituted, identically or differently, by halogen and/or alkyl having from 1 to 4 carbon atoms, or
represents cycloalkenyl having from 3 to 7 carbon atoms, with these radicals being able to be monosubstituted to tetrasubstituted, identically or differently, by halogen and/or alkyl having from 1 to 4 carbon atoms, or represents saturated or unsaturated heterocyclyl having from 3 to 7 ring atoms, of which in each case from 1 to 3 are identical or different hetero-atoms such as oxygen, nitrogen or sulphur, with the radicals being able to be monosubstituted to trisubstituted, identically or differently, by halogen, alkyl having from 1 to 4 carbon atoms, alkoxy having from 1 to 4 carbon atoms and/or halogenoalkyl having from 1 to 4 carbon atoms and from 1 to 5 identical or different halogen atoms, or
represents aryl having from 6 to 10 carbon atoms, with each of these radicals being able to be monosubstituted to pentasubstituted, identically or differently, by halogen, straight-chain or branched alkyl having from 1 to 4 carbon atoms, straight-chain or branched halogenoalkyl having from 1 to 4 carbon atoms and from 1 to 9 identical or different halogen atoms, straight-chain or branched alkoxy or alkylthio having from 1 to 4 carbon atoms, straight-chain or branched halogenoalkoxy or halogenoalkylthio having from 1 to 4 carbon atoms and from 1 to 9 identical or different halogen atoms, phenyl, phenoxy, phenylthio, benzyloxy, benzylthio or phenylethyloxy,
or by doubly linked alkylene having 3 or 4 carbon atoms or by doubly linked dioxyalkylene having 1 or 2 carbon atoms, with the two latter radicals themselves being able to be monosubstituted or polysubstituted, identically or differently, by halogen, straight-chain or branched alkyl having from 1 to 4 carbon atoms and/or straight-chain or branched halo-genoalkyl having from 1 to 4 carbon atoms and from 1 to 9 identical or different halogen atoms.
R2 preferably represents straight-chain or branched alkyl having from 1 to 8 carbon atoms or
R2 preferably represents cycloalkyl having from 3 to 7 carbon atoms, with these radicals being able to be monosubstituted to tetrasubstituted, identically or differently, by halogen and/or alkyl having from 1 to 4 carbon atoms, or
represents cycloalkenyl having from 3 to 7 carbon atoms, with these radicals being able to be monosubstituted to tetrasubstituted, identically or differently, by halogen and/or alkyl having from 1 to 4 carbon atoms, or represents saturated or unsaturated heterocyclyl having from 3 to 7 ring atoms of which in each case from 1 to 3 are identical or different hetero-atoms such as oxygen, nitrogen or sulphur, with the radicals being able to be monosubstituted to trisubstituted, identically or differently, by halogen, alkyl having from 1 to 4 carbon atoms, alkoxy having from 1 to 4 carbon atoms and/or halogenoalkyl having from 1 to 4 carbon atoms and from 1 to 5 identical or different halogen atoms, or
represents aryl having from 6 to 10 carbon atoms, with each of these radicals being able to be monosubstituted to pentasubstituted, identically or differently, by halogen, nitro, amino, hydroxy, formyl, carboxy, carbamoyl, thiocarbamoyl; alkyl, alkoxy, alkylthio, alkylsulphinyl, or alkylsulphonyl which may each be straight-chain or branched and each have from 1 to 6 carbon atoms; straight-chain or branched alkenyl or straight-chain or branched alkenyloxy each having from 2 to 6 carbon atoms; halogenoalkyl, halogenoalkoxy, halogenoalkylthio, halogenoalkylsulphinyl or halogenoalkylsulphonyl which may each be straight-chain or branched and each have from 1 to 6 carbon atoms and from 1 to 13 identical or different halogen atoms;
straight-chain or branched halogenoalkenyl or straight-chain or branched halogenoalkenyloxy each having from 2 to 6 carbon atoms and from 1 to 13 identical or different halogen atoms; alkylamino, dialkylamino, alkylcarbonyl, alkylcarbonyloxy, alkoxycarbonyl, alkylsulphonyloxy, hydroximinoalkyl or alkoximinoalkyl which may each be straight-chain or branched and each have from 1 to 6 carbon atoms in the individual alkyl parts; phenyl, phenoxy, phenylthio, benzyloxy, benzylthio or phenylethyloxy,
or by doubly linked alkylene having 3 or 4 carbon atoms or by doubly linked dioxyalkylene having 1 or 2 carbon atoms, with the two latter radicals themselves being able to be monosubstituted or polysubstituted, identically or differently, by halogen, straight-chain or branched alkyl having from 1 to 4 carbon atoms and/or straight-chain or branched halogenoalkyl having from 1 to 4 carbon atoms and from 1 to 9 identical or different halogen atoms.
R3 preferably represents hydrogen, amino, or
R3 preferably represents straight-chain or branched alkyl having from 1 to 10 carbon atoms or straight-chain or branched alkoxy having from 1 to 6 carbon atoms, with the alkyl radicals or alkoxy radicals being able to be monosubstituted or polysubstituted, identically or differently, by halogen, nitro, amino, hydroxy, formyl, carboxy, carbamoyl;
and/or by alkoxy, alkylthio, alkylsulphinyl or alkylsulphonyl which may each be straight-chain or branched and each have from 1 to 6 carbon atoms;
and/or by straight-chain or branched alkenyl or straight-chain or branched alkenyloxy each having from 2 to 6 carbon atoms;
and/or by halogenoalkoxy, halogenoalkylthio, halogenoalkylsulphinyl or halogenoalkylsulphonyl which may each be straight-chain or branched and each have from 1 to 6 carbon atoms and from 1 to 13 identical or different halogen atoms;
and/or by alkylamino, dialkylamino, alkylcarbonyl, alkylcarbonyloxy, alkoxycarbonyl, alkylsulphonyloxy, hydroximinoalkyl or alkoximinoalkyl which may each be straight-chain or branched and each have from 1 to 6 carbon atoms in the individual alkyl parts;
or by doubly linked alkylene having from 1 to 6 carbon atoms or by doubly linked dioxyalkylene having from 1 to 4 carbon atoms, with the two latter radicals themselves being able to be monosubstituted or polysubstituted, identically or differently, by halogen, straight-chain or branched alkyl having from 1 to 4 carbon atoms and/or straight-chain or branched halogenoalkyl having from 1 to 4 carbon atoms and from 1 to 9 identical or different halogen atoms, or
by phenyl, or
R3 preferably represents cycloalkyl having from 3 to 7 carbon atoms, with these radicals being able to be monosubstituted to tetrasubstituted, identically or differently, by halogen and/or alkyl having from 1 to 4 carbon atoms, or
represents cycloalkenyl having from 3 to 7 carbon atoms, with these radicals being able to be monosubstituted to tetrasubstituted, identically or differently, by halogen and/or alkyl having from 1 to 4 carbon atoms, or represents saturated or unsaturated heterocyclyl having from 3 to 7 ring atoms of which in each case from 1 to 3 are identical or different hetero atoms such as oxygen, nitrogen or sulphur, with the radicals being able to be monosubstituted to trisubstituted, identically or differently, by halogen, alkyl having from 1 to 4 carbon atoms, alkoxy having from 1 to 4 carbon atoms and/or halogenoalkyl having from 1 to 4 carbon atoms and from 1 to 5 identical or different halogen atoms, or
represents aryl having from 6 to 10 carbon atoms, with each of these radicals being able to be monosubstituted to pentasubstituted, identically or differently, by halogen, straight-chain or branched alkyl having from 1 to 4 carbon atoms, straight-chain or branched halogenoalkyl having from 1 to 4 carbon atoms and from 1 to 9 identical or different halogen atoms, straight-chain or branched alkoxy or alkylthio having from 1 to 4 carbon atoms, straight-chain or branched halogenoalkoxy or halogenoalkylthio having from 1 to 4 carbon atoms and from 1 to 9 identical or different halogen atoms,
phenyl, phenoxy, phenylthio, benzyloxy, benzylthio or phenylethyloxy,
or by doubly linked alkylene having 3 or 4 carbon atoms, or by doubly linked dioxyalkylene having 1 or 2 carbon atoms, with the two latter radicals themselves being able to be monosubstituted or polysubstituted, identically or differently, by halogen, straight-chain or branched alkyl having from 1 to 4 carbon atoms and/or straight-chain or branched halogenoalkyl having from 1 to 4 carbon atoms and from 1 to 9 identical or different halogen atoms.
n also particularly preferably represents the numbers 0, 1 or 2.
R1 particularly preferably represents methyl, ethyl, n-propyl or isopropyl.
R2 particularly preferably represents cyclohexyl, norbornyl or cyclohexenyl, with these radicals being able to be monosubstituted to tetrasubstituted, identically or differently, by fluorine, chlorine, methyl and/or ethyl, or represents furyl, pyridyl or thienyl, with these radicals being able to be monosubstituted to trisubstituted, identically or differently, by fluorine, chlorine, bromine, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, methoxy, ethoxy, n-propoxy, i-propoxy, trifluoromethyl and/or trifluoroethyl, or
represents phenyl or naphthyl, with each of these radicals being able to be monosubstituted to pentasubstituted, identically or differently, by fluorine, chlorine, bromine, nitro, amino, hydroxy, formyl, carboxy, carbamoyl, thiocarbamoyl, methyl, ethyl, n- or i-propyl, n-, i-, s- or t-butyl, methoxy, ethoxy, n- or i-propoxy, methylthio, ethylthio, n- or i-propylthio, methylsulphinyl, ethylsulphinyl, methylsulphonyl or ethylsulphonyl, trifluoromethyl, trifluoroethyl, difluoromethoxy, trifluoromethoxy, difluorochloromethoxy, trifluoroethoxy, difluoromethylthio, difluorochloromethylthio, trifluoromethylthio, trifluoromethylsulphinyl or trifluoromethylsulphonyl, methylamino, ethylamino, n- or i-propylamino, dimethylamino, diethylamino, methoxycarbonyl, ethoxycarbonyl, phenyl, phenoxy, phenylthio, benzyloxy, benzylthio or phenylethyloxy, or by in each case doubly linked trimethylene (propane-1,3-diyl), methylenedioxy or ethylenedioxy which may each be unsubstituted, monosubstituted or polysubstituted, identically or differently, by fluorine, chlorine, methyl, trifluoromethyl, ethyl, n- or i-propyl.
R3 particularly preferably represents hydrogen, amino, methyl, ethyl, n- or i-propyl, n-, i-, s-butyl, pentyl, hexyl, heptyl, octyl, methoxy, ethoxy, hydroxymethyl, 1-hydroxy-1-ethyl, methoxymethyl, methoxyethyl, methoxypropyl, ethoxymethyl, ethoxyethyl, 2-carboxy-1 -hydroxy-1-ethyl, 2-carboxy-1-ethyl, 3-carboxy-1-propyl or benzyl.
The optically active amides of the formula (II) are known and/or can be prepared by known methods (cf. DE-A 4332738 and Chimia 48, 570 (1994)).
Suitable diluents for carrying out the first stage of the process of the invention are all polar, aprotic, organic solvents. Preference is given to using nitriles such as acetonitrile, propionitrile, n- or i-butyronitrile or benzonitrile; amides such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methylformanilide, N-methylpyrro-lidone or hexamethylphosphoramide, sulphoxides such as dimethyl sulphoxide; sulphones such as sulpholane.
Suitable bases for carrying out the first stage of the process of the invention are all customary inorganic and organic acid binders having high basicity. Preference is given to using alkaline earth metal or alkali metal hydrides, hydroxides, amides or alkoxides, for example sodium hydride, sodium amide, sodium methoxide, sodium ethoxide, potassium tert-butoxide, sodium hydroxide or potassium hydroxide.
The reaction temperatures for carrying out the first stage of the process of the invention can be varied within a relatively wide range. Use is generally made of temperatures between 0xc2x0 C. and 280xc2x0 C., preferably between 20xc2x0 C. and 250xc2x0 C.
Both the first and second stages of the process of the invention are generally carried out under atmospheric pressure. However, it is also possible in each case to use increased or reduced pressure. Thus, the reactions can be carried out under pressures between 0.1 bar and 10 bar.
Furthermore, both the first and second stages of the process of the invention can be carried out under an inert gas atmosphere, preferably under nitrogen or argon.
In carrying out the first stage of the process of the invention, use is generally made of from 0.01 to 2 mol, preferably from 0.02 to 1 mol, of strong base per 1 mol of optically active amide of the formula (II). The work-up is carried out by customary methods. If the reaction is carried out in the absence of diluents, the procedure is generally to admix the reaction mixture with an organic solvent which is sparingly miscible with water, to wash the resulting mixture with water, then dry and evaporate it. If the reaction is carried out in the presence of diluents, the procedure is generally to evaporate the reaction mixture, to admix the residue with water, to extract with an organic solvent which is sparingly miscible with water and to dry and evaporate the combined organic phases.
For carrying out the second stage of the process of the invention according to variant (a), suitable bases are all customary strong inorganic and organic bases. Preference is given to those bases which have been specified as preferred in connection with the first stage of the process of the invention. Additional possibilities are acids such as dilute sulphuric acid and hydrochloric acid.
Suitable diluents for carrying out the second stage of the process of the invention according to variant (a) are all organic solvents customary for the saponification of amides. Preference is given to using alcohols such as methanol, ethanol, n-butanol and propanol, in addition dimethyl sulphoxide and also water, and mixtures of these solvents.
The reaction temperatures for carrying out the second stage of the process of the invention according to variant (a) can also be varied within a relatively wide range. Use is generally made of temperatures between 0xc2x0 C. and 200xc2x0 C., preferably between 20xc2x0 C. and 150xc2x0 C.
For carrying out the second stage of the process of the invention according to variant (a), use is generally made of from 0.1 to 5 mol, preferably from 1 to 3 mol, of base or acid per 1 mol of racemic amide of the formula (Ia). The work-up is carried out by customary methods. The procedure is generally to extract the reaction mixture, if desired after prior evaporation, with an organic solvent which is sparingly miscible with water, and to wash, dry and evaporate the combined organic phases.
For carrying out the second stage of the process of the invention according to variant (b), preferred hydroxides are sodium hydroxide, potassium hydroxide or calcium hydroxide.
The reaction temperatures for carrying out the second stage of the process of the invention according to variant (b) can also be varied within a relatively wide range. Use is generally made of temperatures between 40xc2x0 C. and 220xc2x0 C., preferably between 40xc2x0 C. and 180xc2x0 C.
For carrying out the second stage of the process of the invention according to variant (b), use is generally made of from 0.02 to 5 mol of alkali metal hydroxide or a corresponding amount of alkaline earth metal hydroxide per 1 mol of racemic amide of the formula (Ia). The work-up is carried out by customary methods. The procedure is generally to admix the reaction mixture with water, then extract it with an organic solvent which is sparingly miscible with water and to dry and evaporate the combined organic phases.
In a preferred embodiment, the procedure in carrying out the process of the invention is to generally use from 0.02 to 1.0 mol, preferably from 0.05 to 0.5 mol, of alkali metal hydroxide per 1 mol of optically active amide of the formula (II) and to heat the mixture to temperatures between 20xc2x0 C. and 280xc2x0 C., preferably between 50xc2x0 C. and 250xc2x0 C., so that a melt is formed. After racemization is complete (after from 0.5 to 36 hours), the resulting racemic amide of the formula (Ia) can be saponified by addition of from 20 to 2000 ml of water per mol of amide and, if desired, by addition of further alkali metal hydroxide or of alkaline earth metal hydroxide to give the racemic amine, by heating to temperatures between 20xc2x0 C. and 100xc2x0 C.
A further preferred embodiment of the process of the invention comprises using from 0.02 to 1.0 mol, preferably from 0.05 to 0.5 mol, of an alkali metal hydride, preferably sodium hydride, per 1 mol of optically active amide of the formula (II) and heating the mixture to temperatures between 20xc2x0 C. and 280xc2x0 C., preferably between 50xc2x0 C. and 250xc2x0 C., so that a melt is formed. If desired, this can be followed by saponification of the amide.
In a further preferred embodiment, the procedure for the process of the present invention is to use from 0.02 to 1.0 mol, preferably from 0.05 to 0.5 mol, of an alkali metal or alkaline earth metal alkoxide, preferably potassium tert-butoxide per 1 mol of optically active amide of the formula (II) and to work in the presence of a polar, aprotic, organic solvent. As solvents, preference is here given to using nitriles such as acetonitrile, propionitrile, n- or i-butyronitrile or benzonitrile; also amides such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-formanilide, N-methylpyrrolidone or hexamethylphosphoramide; in addition sulphoxides such as dimethyl sulphoxide; and also sulphones such as sulpholane, optionally also in admixture with alcohols such as tert-butanol.
This can be followed by saponification of the amide.
In another preferred embodiment, the procedure for the process of the invention is to generally use from 0.02 to 1.0 mol, preferably from 0.05 to 0.5 mol, of a metal alkoxide, preferably an alkali metal, alkaline earth metal or earth metal alkoxide, in particular potassium tert-butoxide, per 1 mol of optically active amide of the formula (II) and to heat the mixture to temperatures between 40xc2x0 C. and 220xc2x0 C., so that a melt is formed. If the amide of the formula (II) is a compound in which R3 is hydrogen, then the corresponding racemic amine can be obtained directly after the racemization step by addition of from 0.02 to 5 mol of an alkali metal or alkaline earth metal hydroxide, such as sodium hydroxide, potassium hydroxide or calcium hydroxide, per mol of amide and again heating to temperatures between 40xc2x0 C. and 220xc2x0 C. (from 0.5 to 24 hours).
In a further preferred embodiment of the process of the invention, the procedure is to use generally from 0.02 to 1 mol, preferably from 0.05 to 0.5 mol, of an alkali metal, alkaline earth metal or earth metal hydroxide, in particular potassium hydroxide, per 1 mol of optically active amide of the formula (II) and to work in the presence of a polar, aprotic, organic solvent. As solvents, preference is here given to using nitriles such as acetonitrile, propionitrile, n- or i-butyronitrile or benzonitrile; also amides such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methylformanilide, N-methylpyrrolidone or hexamethylphosphoramide; in addition sulphoxides such as dimethyl sulphoxide; and also sulphones such as sulpholane, optionally in admixture with alcohols such as tert-butanol.
Saponification of the amide can follow.
The racemic amides and amines obtainable by the process of the invention can be used directly or after prior resolution of the racemate as intermediates for further syntheses. Particularly (R)-amines of the formula (I) are valuable intermediates for preparing pharmaceuticals or active compounds having insecticidal, fungicidal or herbicidal properties (cf. EP-A 0 519 211, EP-A 0 453 137, EP-A 0 283 879, EP-A 0 264 217 and EP-A 0 341 475). Thus, for example, the fungicidally active compound of the formula
is obtained by reacting the (R)-1-(4-chloro-phenyl)-ethylamine of the formula
with 2,2-dichloro-1-ethyl-3-methyl-1-cyclopropanecarboxylic chloride of the formula
in the presence of an acid binder and in the presence of an inert organic diluent.

Process for preparing racemic amino derivatives

Abstract: are prepared by a new process which comprises reacting an optically active amide of the formula

Abstract: in which

Abstract: with a strong base, optionally in the presence of an organic diluent and, if desired, reacting the resulting racemic amide.

Abstract: either

Abstract: or

Abstract: b) if the compound of the formula (I) is an amide in which R3 is hydrogen, with an alkali metal hydroxide or an alkaline earth metal hydroxide.


A digital transmission system comprising a receiver, the receiver including a receiver input stage and a digital memory for storing a sequence of binary symbols of sample values, formed in the receiver input stage, of a signal distorted by a transmission channel, and an equalizer for forming a sequence of binary estimates from the sample values by an impulse response of a substitute system describing the transmission channel, the impulse response being determined by first correlations of coefficients of a known training sequence with the sample values of a part of the known training sequence extended by at least one binary symbol. To make a channel estimation possible for a higher degree of the impulse response of the transmission channel, and also to carry out the channel estimation always with a maximum quality, a variable first correlation window size and a variable number of first correlations are used for adapting the impulse response of the substitute system to the impulse response of the transmission channel. A reduction of the correlation window size enables more cross-correlation values to be formed with one sequence of sample values, so that an increase of the degree of the impulse response of the estimated transmission channel becomes possible. With a more favorable transmission behavior, the correlation window size can be extended by one or more known binary symbols, so that the quality of the estimate of the impulse response is enhanced.

The invention relates to a digital transmission system comprising a receiver, the receiver including a receiver input stage and a digital memory for storing a sequence of binary symbols of sample values 1 formed in the receiver input stage 1 of a signal distorted by a transmission channel, and an equalizer for forming a sequence of binary estimates from the sample values by means of an impulse response of a substitute system describing the transmission channel, this impulse response being determined by first correlations of coefficients of a known training sequence with the sample values of a part of the known training sequence extended by at least one binary symbol.
Furthermore, the invention relates to a receiver including a receiver input stage 1 and including a digital memory for storing a sequence of binary symbols of sample values 1 formed in the receiver input stage 1 of a signal distorted by a transmission channel, and an equalier for forming a sequence of binary estimates from the sample values by means of an impulse response of a substitute system describing the transmission channel, this impulse response being determined by first correlations of coefficients of a known training sequence with the sample values of a part of the known training sequence extended by at least one binary symbol.

Equalizer with extended channel estimation for a receiver in a digital transmission system


A packaging system for a corrugated cardboard shipping container. The system uses two vertical compartmented inserts divided by a horizontal insert. The compartmented insert can be configured by a packer to consist of four to two rectangular compartments. The horizontal insert can be folded in half or have a quarter section folded away in order to accommodate a loading plan that requires items to protrude above the height of the bottom vertical compartmented insert. An optional diagonal divider and dunnage may be used prior to sealing the container.

Technical Field
The present invention relates to a packaging system and corrugated cardboard packaging box with inserts used for shipping goods. Specifically, the invention relates to a set of components used in a corrugated cardboard box that compartmentalize the box into weight bearing compartments, thus allowing for the simultaneous packaging within the box of items having disparate shapes, sizes, and density. This creates a unique ability to ship light and fragile products with heavy products.
Description of Related Art
Retail online purchasing by consumers has exploded over recent years. Consumer goods of all types can now be ordered online and shipped directly to the consumer. The means for shipping such product is typically a corrugated box in which the product ordered is placed, along with dunnage (such as filler paper, plastic bubble wrap, styrofoam pieces, etc.), which is used to protect the product from damage during shipping. Shipping product in this way, in a corrugated box with dunnage, is adequate for most packaging solutions. However, an emerging retail grocery market available through online ordering and delivery to the consumer presents challenges to this standard shipping method. Specifically, consumers have begun to order grocery items online through outlets such as Amazon's PrimePantry™ and Walmart.com.
The model of offering grocery items to a consumer through online sale and shipped delivery poses unique challenges and problems. Many grocery items don't combine well in a single box. Yet, the model for retail online grocery services requires that all items be shipped in as few boxes as possible in order to limit shipping cost. In fact, some models for online grocery shopping limit the consumer to the filling of a single box per order based on the weight and cubic size of the order. Consequently, any packaging used to support this model must provide protection for products of disparate shape, size, weight, and density, as is typical of a grocery order.
For example, a single order from a consumer may include canned goods, various boxes and bottles, various bagged goods such as bread products and flexible pillow bags with crushable contents such as potato chips. The problems faced in this situation can be understood when imaging a box filled with heavy canned goods combined with several pillow bags holding potato chips and tortilla chips. While packing this box, the best protection that can be provided under current practices is to place all the heavier items (the canned goods) at the bottom of the box and the lighter items (the pillow bags) at the top of the box. Some dunnage can be added to provide some extra protection. However, unless the box maintains the same orientation throughout the entire shipping process, the heavier items on the bottom of the box will at some point crush the pillow bags placed at the top of the box. This usually results in rupturing of the bags and crushing of the food product found within the pillow bags.
A prior art alternative to a corrugated box with dunnage involves a corrugated box with a modular product protection system comprising one or more vertical compartmented insert. This compartmented insert is illustrated in FIGS. 1A, 1B, 1C, 1D, 1E, and 1F. FIG. 1A shows one embodiment of a compartmented insert in a folded or flat configuration suitable for storage. The insert is typically made from corrugated cardboard. Shown in FIG. 1A is one side of the insert when in the folded configuration. Six panels 10, 12, 14, 16, 18, 20 of the insert can be seen. The top panels 10, 12, 14 are separated from the bottom panels 16, 18, 20 by a cut 62 through on side of the piece. Also shown are folding points 60.
The insert is deployed by first forming the flat insert shown in FIG. 1A into a two-tiered rectangular insert shown in FIG. 1B. The interior panels on the top of the insert 26, 32, 34, as well as an interior divider 22 can now be seen. Also shown is an interior flap 30 which attaches the interior divider 22 to one of the interior side panels 34.
Also shown in FIG. 1B is a folding point 64 about which the upper portion of the now expanded insert comprising the upper panels 10, 12, 14 will be separated from the lower half of the insert comprising the lower panels 16, 18, 20 at the cut line 62. This process is shown in FIG. 1C wherein the upper portion of the insert comprising the upper panels 10, 12, 14 is being rotated away about the fold line 64 from the bottom half of the insert comprising the lower panels 16, 18, 20. Also revealed are additional internal panels 28, 36, 38 and an additional interior divider 24.
FIG. 1D shows the continuation of the action shown in FIG. 1C as the upper half of the compartmented insert is further rotated about the folding line 64 toward a final deployment. Interior panels 26, 28, 32, 34, 36, 38 are again visible along with two interior dividers 22, 24.
The final deployment of the vertical compartmented insert is illustrated in FIG. 1E. It can be seen that what was formerly an upper panel 14 is now in the same horizontal plane as a lower panel 20 and that these two panels 14, 20 abut. The deployed insert is now ready for placement in a box. Two additional panels 40, 42 are now also apparent from the interior of the compartmented insert. It can also be seen that the fold line 64 has now become a ridge 64 made up of one edge of a continuous piece of material consisting of two corrugated cardboard sheets. Further, it can be seen that two of the panels 36, 38 are now panels on an interior divider made up on one of the sheets of corrugated cardboard that forms the strong ridge 64 bisecting the center of the now fully deployed vertical compartmented insert. This deployed compartmented insert, as shown, has four compartments or cells, each cell defined by four interior panels/dividers.
This deployed compartmented insert is of such dimension as to nest in a companion corrugated box 190 such as the one illustrated in FIG. 1F. As is standard of a rectangular-shaped corrugated box 190, the box 190 illustrated in FIG. 1F is show in an open position with two wide flaps 194, and two long flaps 192, which can be used to seal the box 190. The compartmented insert is nested into the corrugated box 190 by placing it through the opening created by folding back the flaps 192, 194. The box 190 has now been transformed from one compartment to four compartments, thus reducing the direct interaction between products placed therein. Extra dunnage can be added as well to provide additional protection.
This prior art solution of a compartmented container using a compartmented insert nested in a corrugated box is an improvement over the prior art method of packaging a corrugated box with product protected by dunnage. However, the prior art usage of a compartmented insert does not provide the flexibility that an open box with dunnage provides in accommodating product of various sizes and shapes.
Consequently, a packaging system using a corrugate cardboard box as the outer shell is needed that provides both separation of product like a compartmented insert system provides as well as the ability to configure the interior of the box to accommodate products with varying shapes and sizes. This packaging solution should allow for quick and simple construction using common components. This packaging solution should provide protection for product within a corrugated cardboard box wherein the product consists of individual items of various sizes, shapes, and density.


An apparatus for controlling the movement of a vehicle such as a damp truck or the like so as to allow the movement of the vehicle to be correctly induced is disclosed. With the apparatus constructed to the present invention, a first electric wave (m.sub.1), a second electric wave (m.sub.2) and a third electric wave (m.sub.3) are transmitted in synchronization with each other from predetermined locations on the ground different from each other. Then, the electric wave (m.sub.1), the electric wave (m.sub.2) and the electric wave (m.sub.3) are received by two antennas mounted on the vehicle (20), whereby the position where the vehicle (20) is presently located and the attitude angle assumed by the vehicle (20) are detected based on the difference between the time the electric wave (m.sub.1) reaches the vehicle (20) and the time when the electric wave (m.sub.2) reaches the vehicle (20) as well as the difference between the time when the electric wave (m.sub.1) reaches the vehicle (20) and the time when the electric wave (m.sub.3) reaches the vehicle (20).

With respect to an apparatus for allowing a vehicle to move along a preset target course while the movement of the vehicle is automatically induced, it is essential that the apparatus exactly detects the position where the vehicle is presently located, and performances of the apparatus are practically determined depending on how exactly the present position of the vehicle is detected.
A conventional apparatus of the foregoing type which assures that the target course can be changed to another one, i.e., a conventional apparatus of the foregoing type having excellent flexibility in respect of a target course to be assumed by the vehicle is typically disclosed in an official gazette of, e.g., Japanese Laid-Open Patent NO. 70618/1986 which is titled "System for allowing a vehicle to move in an unmanned manner". According to the system of the prior invention, as the vehicle moves, a distance of movement of the vehicle on a two-dimensional coordinate is sequentially calculated with reference to the speed of movement of the vehicle and the orientation angle of movement of the vehicle so that the present position of the vehicle on the two-dimensional coordinate is detected based on the sequentially calculated values.
With the conventional apparatus as described above, the speed of movement of the vehicle is detected by a vehicle speed sensor and the orientation angle of movement of the vehicle is detected by a gyro-compass serving as an orientation sensor. For the reason, it is unavoidable that detection errors derived from these sensors are increased accumulatively. Especially, an error of the running speed appearing due to slippage of tires during movement of the vehicle and an error of the orientation angle appearing due to offset drift of the gyro-compass remarkably degrade the detection accuracy in respect of the position of the vehicle to be detected.
Therefore, the conventional apparatus has a drawback that induction control is generally accomplished with a deteriorated accuracy.
To obviate the foregoing drawback, a proposal has been made such that a station having suitable marks and induction cables laid thereon is installed at a known important location on the target course and a sensor is mounted on the vehicle to detect the magnetic field generated by the marks and the induction cables, whereby the detection error derived from the speed sensor and other components is periodically corrected based on outputs from the sensor. According to the aforementioned proposal having exterior induction units such as marks or the like employed therefor, however, the conventional apparatus has still a drawback that it fails to secure certain flexibility in respect of variation of the target course to another one to be assumed by the vehicle, because the target course is unchangeably determined.
The present invention has been made with the foregoing background in mind.
Therefore, an object of the present invention is to provide an apparatus for controlling the movement of a vehicle wherein the apparatus assures that the movement of the vehicle can exactly be induced while an advantage of flexibility in respect of a target course to be assumed by the vehicle is sustained.

Apparatus for controlling movement of vehicle


An image capture system is presented where the dynamic range of photo imaging devices, such as a still or video camera, is increased by varying sensor exposure time on a pixel-by-pixel basis under digital camera processor control. The systems photo sensors are continuously illuminated without reset over the exposure interval. In addition to being interrogated at the end of the exposure interval, the pixels are also non-destructively interrogated at one or more intermediate times during the interval. At each interrogation, the image capture system determines individually whether the pixels have saturated and if not, the parameter value is recorded; if the pixel has saturated, the previously stored value from the preceding interval is maintained. To produce the final sensor value for the whole exposure interval, the data for pixels that reached the saturation level are adjusted to compensate for their shortened exposure.

The present invention relates generally to image capturing systems, and, more particularly, to increasing the dynamic range of image sensing devices, such a CMOS pixel circuits, having limited dynamic range.
Digital cameras and other electronic image capturing systems have become increasingly common. In such systems, photographic film is replaced by an array of photo sensors. Although such systems have a number of advantages with respect to film based system, they typically lack the dynamic range of photographic film.
A common type of image sensing element uses CMOS active picture elements. Such image sensor devices of the CMOS active picture element variety rely on having an image sensing area divided into a large number of photosensitive areas, or pixels. These areas produce an output signal determined by the light incident on the physical location of the pixel, with the pixel information being read out to a set of external electronics following a predetermined scanning sequence. Random addressing, sequential addressing, or some combination of the two may be used. A typical pixel circuit using three transistors is shown in FIG. 1.
In FIG. 1, the diode D1 is normally biased in its reverse direction, so that if it is previously charged to a voltage, photons impinging on the diode will produce carriers which discharge its terminal voltage as seen at wire 3. Transistor M1 serves as a reset transistor for recharging the diode voltage. When the row voltage VRES on wire 1 is taken in a sufficiently positive direction, it causes conduction in transistor M1 and charges the diode voltage towards the voltage VDD on wire 4. This reset action is normally initiated at the start of a time when the diode will be used to accumulate photon information about the impinging light's intensity.
After a predetermined exposure time, the light intensity information for this pixel is read out by using the transistors M2 and M3. Transistor M2 serves as a source follower, with the voltage on its source at 5 being a function of the diode voltage at 3. The voltage source VDD on wire 4 provides a current to operate the source follower. When the particular row of pixels containing this pixel is selected for readout, the row voltage VSEL on wire 2 is taken in a positive direction, turning on transistor M3. Transistor M3 is usually operated as a switch, to connect the source terminal of M2 to the readout column line 6. A current sink I at the end of the column line provides operating current for the source follower M2, so that the output voltage on the column line VOUT will be proportional to the voltage on the diode at 3.
After the intensity information is read out and is no longer needed, the row reset input VRES may be activated to cause the pixel voltages to be restored to the value representing zero light intensity. In addition to functioning as a reset transistor, M1 may also be used to limit the lower voltage to which wire 3 may descend. This prevents diode D1 from becoming zero or forward biased, and therefore prevents the injection of minority charges into the substrate. Charges injected into the substrate may diffuse to adjacent pixels, causing spreading or blooming in the image of bright image spots. In many systems, this anti-blooming feature is used to hold the pixel voltages at their lower level until the reset action is initiated to prepare for a new image exposure.
For simple image sensor usage, the pixel in FIG. 1 may be formed into an array of cells with control and readout circuitry surrounding it on a single silicon integrated circuit. FIG. 2 shows an exemplary two-dimensional image sensor conceptual diagram.
In the two-dimensional imager of FIG. 2, a rectangular area 10 is populated with an array of pixels such as those shown in FIG. 1, with some of the row and column wires shown for clarity. Control logic 11, primarily located at an edge of the pixel array, operates the VSEL and VRES wires for each row of the pixel array. Counters, gates, and/or shift registers in this logic generate the control signals needed to follow the desired pixel readout sequence. When a pixel row is selected, the information from it goes to the readout circuitry 12, as signals on the columns wires 13. The resulting pixel information is output on 14 as either analog or digital signals as needed.
For normal sequential scanning, the control logic 11 activates one row reset signal VRES at a time, following a linear scan pattern descending from the top of the pixel array 10 to the bottom. Consider for this example that at the time of interest, the VRES signal is being applied to row A. At the same time, the control logic also sends the select signal VSEL to a different row, which we may choose to be row B in this example. The pixel information from row B will then be sent to the readout circuitry 12 on the entire set of column wires, of which 13 is an example, and the readout circuitry will choose which column information to send out on the connection 14.
The total pixel exposure interval for a row of image sensor pixels is determined by the delay time between the application of a first VRES and a second VRES to a particular pixel row. During this time period the light illuminating the image sensor is not interrupted. The amount of sensor pixel row exposure per interrogation cycle interval is determined by the delay time between the application of the VRES and the VSEL to a particular sensor pixel row. If rows are being scanned in a regular periodic manner, this time interval will be determined in turn by the row number spacing between row A and row B. Thus the amount of time the image sensor is exposed to light will be a function of the row timing delay between the row reset action and the row readout action as determined by the control logic. Image readout from a different row, such as row C with a different relative location, will give different effective image exposure time.
Although this discussion is based on one of the simpler three transistor cells in use, this configuration exhibits the sort of limited dynamic range due to saturation that is also found in the various other image sensing element designs known in the art. Compared to the dynamic range available from film, such elements will consequently exhibit saturation when exposed to a bright image while still being under exposed for a dark image.
There are numerous methods and apparatus that have been proposed to increase the dynamic range of photo sensors in general, and CMOS sensors in particular. Perhaps the most straightforward is just to increase amount of charge that is stored by the diode D1 of FIG. 1; however, this results in a larger pixel circuit, when the trend is to reduce pixel size in order to increase resolution.
The prior art present a number of alternate techniques for dealing with these problems; however, these suffer from one or more serious practical problems, such as requiring non-standard sensors, increased memory requirements, or multiple sensor resets. For example, U.S. Pat. No. 6,977,685 is illustrative of the class of CMOS sensor dynamic range enhancement technologies that rely upon resetting individual pixels during the course of photo sensor exposure to light as the primary means of effecting dynamic range extension. In U.S. Pat. No. 6,946,635 the sensor pixels are read out two or more times without resetting the image sensor, but require that these readings are separated by a shutter opening and closing cycle at the point of sensor (photo detector) re-exposure, so that the exposure of the array is not continuous for a single image. U.S. Pat. No. 6,115,065 employs a specific, specialized image sensor that incorporates a memory cell with each image sensor pixel and calls for resetting and reading each sensor pixel site twice, one over a short exposure interval and one over a long exposure interval, and clocking out both of these values from the photo sensor. According to the teachings of U.S. Pat. No. 6,018,365, the dynamic range of an imaging system that utilizes an array of active pixel sensor cells is increased by reading each cell in the array multiple times during each integration period, saving the number of photons collected by the cell, resetting the cell if it would normally saturate by the end of the integration period, and summing of the values collected during the integration period, an approach requiring both the resetting of cells and additional memory. United States Patent Application 20020067415 offers a method of operating a solid state image sensor having an image sensing array that includes a plurality of active pixels, the resetting of each pixel, and after successive time periods, reading outputs from each pixel, to obtain multiple sets of image data having different dynamic ranges that are then combined, an approach again requiring both the resetting of cells and additional memory.
All these various approaches suffer from the need to either use non-standard CMOS sensors that are significantly more costly to manufacture and control than the CMOS sensors commonly in use, or require significantly more image buffer memory to properly operate. One proposed approach for increasing CMOS sensor dynamic range, while using standard CMOS sensors, is to capture two to more images, taken very close together in time, at different exposures, at least one which displays the shadow detail of the image (taken at a high exposure) and at least one which displays the highlight detail (taken at a low exposure). These multiple images, which need to be corrected for any motion present in the images occurring between individual image capture, are combined into a single image that displays both shadow and highlight detail. This approach does result in an increase of dynamic range; however, the processing complexity to motion compensate and appropriately combine the two or more captured images, and the additional buffer memory required, is excessive by current standards, and therefore this solution, to date, has not been shown as a practical answer to the problem. The need to use specialized, non-standard sensors, add memory, or reset pixels during the expose interval all have serious drawbacks. Consequently, there is a need for improved techniques to increase the dynamic range of photo sensors.

Wide dynamic range image capturing system method and apparatus


A switch (110R.3) uses a forwarding database (140F) to forward multicast packets. The switch participates in a multicast protocol (e.g. PIM) with other switches, and also uses a snooping database (e.g. for IGMP snooping) to learn about local group members, i.e. members for which the router serves as a local multicast router (e.g. the local members do not participate in the multicast protocol). When the switch learns of a local member of a multicast group, the switch updates the snooping database but may or may not install the snooping information in the forwarding database. Thus, the forwarding database is not necessarily provisioned for locally sourced data packets addressed to the group until receipt of a locally sourced data packet addressed to the group. If no such packets are received, the forwarding database is not provisioned for such packets, and therefore its size is reduced. Other features are also provided.

The present invention relates to telecommunications networks, and more particularly to multicast transmissions.
FIG. 1 illustrates a telecommunications network having network nodes 110 interconnected by links 130. Nodes 110 include switches or routers 110R.1, 110R.2, and end stations 110E.1, 110E.2, . . . . Each link 130 may be a wired or wireless link or may be a network (e.g. LAN, i.e. Local Area Network). A switch may forward packets 210 (FIG. 2) based on the packets' L2 (layer 2) destination address DA2 and/or L3 (layer 3) destination address DA3. As shown, the packet also has a layer-2 source address SA2 and may have a layer-3 source address SA3. As used herein, the terms "switch" and "router" are synonymous and refer to any computer that forwards packets transmitted over a network, but the term "router" is preferred for layer 3 forwarding.
A multicast protocol may allow a packet's destination address (DA2 and/or DA3) to specify a group of nodes 110. (Actually, an address usually identifies a node's network interface; when we say that an address identifies a node, we mean that the address identifies one or more of the node's interfaces.) A multicast transmission to a group of nodes conserves network resources compared to separate, unicast transmissions to each node. For example, if nodes 110E.1, 110E.2, 110E.11 form a group, and node 110E.10 sends a packet to the group, then only one copy of the packet is delivered to router 110R.1 and then to router 110R.2. Router 110R.2 sends one copy of the packet to router 110R.5 for delivery to node 110E.11, and sends another copy to router 110R.4 for delivery to the remaining group members. Network resources are conserved compared to sending a separate copy of the packet from source node 110E.10 to each of the three group members.
Well-known multicast protocols for IP (Internet Protocol) networks include PIM (Protocol Independent Multicast) and IGMP (Internet Group Management Protocol). IGMP version 3 is described for example in RFC 4604 (Internet Engineering Task Force (IETF), August 2006). IGMP version 2 is described in RFC 2236 (IETF, November 1997). Sparse-Mode PIM is defined by RFC 4601 (IETF August 2006). RFCs 4604, 2236, and 4601 are incorporated herein by reference. IGMP defines how a node 110 can join or leave a multicast group. PIM defines how IP routers 110R set up multicast paths for distribution of multicast packets.
IP addresses are layer-3 addresses, and a multicast group in PIM and IGMP is defined by an IP address; in IPv4 (version 4), the multicast address is any IP address in the range of 126.96.36.199 to 188.8.131.52 inclusive. For example, suppose that node 110E.1 wishes to join a group with address 18.104.22.168. Then node 110E.1 sends an IGMP packet of type Report (report group membership) to the node's local multicast router, e.g. 110R.3. Router 110R.3 uses its database (DB) 140 to make packet-forwarding decisions, and router 110R.3 updates this database in response to the IGMP packet. More particularly, DB 140 (FIG. 3) includes a membership list 140L of all group members for which the router serves as a local multicast router (such a router is called "Designated Router" in PIM). The membership list 140L is updated when the router receives an IGMP message of type Report or Leave (leave the group), or when the router does not receive a repeated Report message from a group member within predefined time (the group members periodically re-send Reports in order to retain the group membership). In the example of FIG. 3, the list 140L includes group members 110E.1, 110E.2 for group 184.108.40.206.
DB 140 also includes a Multicast Routing Information Base (MRIB) 140P constructed based on the PIM protocol and used by the router to determine the outgoing interfaces for multicast packets. An exemplary MRIB entry 144 (such as 144.1, 144L.2, or 144L.3) includes:                Source address "SA" (layer 3 address, matched against the packet's source address SA3). The asterisk (*) is a wild card meaning that the entry 144 applies to any Source.        Group Address "GA" (220.127.116.11 for example).        Incoming interface "iif". An interface can be a physical interface (e.g. a port number of a physical port), but an interface may also include virtual information, e.g. the virtual LAN (VLAN). In entry 144.1, the incoming interface is a VLAN with VLAN ID of 200. This corresponds to VLAN 150.1 in FIG. 1. This VLAN is defined for link 130 connecting the router's port P5 to port P1 of router 110R.4. Link 130 may be connected to additional nodes (not shown), and VLAN 150.1 is defined for the traffic between the two routers so that the routers can distinguish this traffic from the traffic to and from other nodes connected to the link. (We will sometimes refer to VLAN 150.1 as VLAN 200; in this document, a VLAN can be referred to by its reference numeral (such as 150.1) or its ID (such as 200).)        Outgoing interface "oif" for the packet, and actions to be performed in packet forwarding. (For example, the actions may specify the layer-2 addresses for packet forwarding.)
According to entry 144.1, if a multicast data packet (as opposed to control packets) is received on VLAN 200, and has the DA3 destination address of 255.1.1.1, then the packet is forwarded on VLAN 150.2 (having VLAN ID of 10) on ports P1, P2 (for delivery to group members 110E.1, 110E.2).
According to PIM, multicast packets are distributed to the group members via one or more distribution trees rooted at pre-determined routers 110. For example, a distribution tree can be rooted at a router called the Rendezvous Point (RP). Assuming for example that the router 110R.2 is the RP, a multicast data packet received by router 110R.3 on VLAN 150.2 (VLAN 10) should be forwarded to router 110R.4 for delivery to the RP. This is accomplished via entry 144L.2: if a packet is received on VLAN 10, and has the DA3 destination address of 255.1.1.1, then the packet is forwarded on VLAN 200. (We use the letter L in 144L.2 to mark entries for locally sourced multicast packets, i.e. packets sourced by nodes for which the router is a local multicast router; such nodes are called "local nodes" below; local nodes may or may not be directly attached to the router.)
Similarly, per entry 144L.3, if a multicast data packet is received on VLAN 20 (VLAN 150.3) and has the DA3 address of 255.1.1.1, then the packet is forwarded to the RP on VLAN 200. An entry of type 144L is created for each incoming interface that can receive locally sourced multicast data packets.
Also, multicast data packets received on VLANs 10 and 20 should be forwarded to the local group members 110E.1, 110E.2 directly rather than through the RP. This is because the RP does not transmit the packets on the interfaces on which the packets are received, and therefore will not return the packets to the routers from which the packets are received. Therefore, router 110R.3 uses a non-PIM mechanism to forward the locally-sourced packets to local group members. One possible mechanism is simply to flood such packets on local VLANs (such as VLANs 10 and 20). This however undesirably increases network traffic. To avoid flooding, the locally sourced multicast data packets are sometimes forwarded only to the group members, i.e. only to nodes in the list 140L for the group.
To speed up and simplify the forwarding process, the router builds a forwarding database 140F (shown in FIG. 3 as MFIB, which stands for Multicast Forwarding Information Base). This database combines all the information needed for fast forwarding decisions. For the packets arriving on VLAN 200, the database entry 148.1 provides the same information as entry 144.1. For the packets arriving on VLAN 10, the entry 148L.2 shows that the packets must be forwarded on VLAN 200 (to the RP, per entry 144L.2) and must also be forwarded on VLAN 10 (ports P1, P2) to the local group members in list 140L. In this way, the forwarding can be performed using the MFIB 140F without consulting the list 140L.
Similarly, per entry 148L.3, the packets arriving on VLAN 20 are to be forwarded on VLAN 200 to the RP and on VLAN 10 (ports P1, P2) to the local group members.
As noted above, forwarding of locally sourced packets to the local group members is based on the IGMP messages. More particularly, DB 140 includes "IGMP snooping" database 140G. Each entry 160 of IGMP snooping database 140G has the same types of fields as entries 144 and 148. Exemplary entry 160.1 shown in FIG. 3 specifies that if a packet has any source address SA3 (as indicated by wild card *), and has IP destination address 255.1.1.1, and the packet arrived on VLAN 10, then the packet should be forwarded on VLAN 10 (ports P1 and P2). Entry 160.2 specifies the same forwarding for the packets arriving on VLAN 20. The router builds IGMP snooping database 140G based on the IGMP messages. The router combines MRIB 140P and IGMP snooping database 140G to construct MFIB 140F. When a multicast data packet arrives, the router searches MFIB 140F for a matching entry (i.e. an entry having the same source address (or the wildcard) as the packet's SA3, the same incoming interface as the interface on which the packet arrived, and the same group address as the packet's DA3). If a matching entry is found, the router forwards the packet based on the entry's outgoing interface, and the router does not need to consult the list 140L. If no matching entry is found, then the router floods the packet on the same VLAN on which the packet arrived, and/or floods the packet on other VLANs, and/or consults other information (e.g. list 140L), depending on the router and the router's configuration.
A router is sometimes conceptualized as having a "forwarding plane" and a "control plane". The forwarding plane is the router portion that receives and transmits packets. The control plane is the router portion that builds and maintains various databases (such as 140) and performs other control functions (that differ from switch to switch). In particular, the control plane processes control messages such as IGMP messages: such messages are sent to the control plane by the forwarding plane. The forwarding plane forwards data packets based on databases such as MFIB 140F that are optimized for forwarding (a similar database can be provided for unicast forwarding). If additional action may be needed to process a packet, the packet is sent to the control plane.
FIG. 4 illustrates an exemplary sequence of events. At step 310, group members 110 (e.g. nodes 110E.1, 110E.2, 110E.11) inform their respective local multicast routers (such as 110R.3 and 110R.5), via IGMP, that these nodes are members of a group (e.g. group 126.96.36.199). This is accomplished by each group member sending an IGMP Report packet 314 to the node's local multicast router. IGMP Report packet 314 is an IP packet having the same general format as in FIG. 2, and in particular the packet 314 includes the destination addresses DA3, DA2 of the local multicast router's interface(s), and the packet includes the source addresses SA2, SA3 of the sending node ("the sender", i.e. the group member). These addresses are not shown in FIG. 4. The Internet Protocol requires a packet to have the Protocol Number field 210P, which must be 2 for IGMP; and Type field 210T, which indicates whether the sender 110 is reporting its membership in the group or is leaving the group. The Type 210T is "Report" in the example shown. The packet's Group Address field 210G is the group address (184.108.40.206). In IGMP version 3, the packet may also include the L3 source addresses from which the sender desires to receive multicast transmissions (these addresses would be inserted instead of the wildcard "*" in MRIB 140P, MFIB 140F, and IGMP snooping database 140G).
At step 320, the local multicast routers updates their DB 140 (databases 140L, 140P, 140G, 140F) as needed. If the IGMP Report sender 110 is the only member of the group in list 140L, then the router notifies all other multicast routers via PIM (PIM's Join message) that the router wishes to receive packets addressed to the group.
FIG. 5 illustrates a possible state of DB 140 of router 110R.3 after execution of step 320 for group members 110E.1, 110E.2. List 140L and IGMP snooping database 140G are as in FIG. 3. MRIB entry 144.1 is the same as in FIG. 3; this entry is used to forward non-locally-sourced traffic. However, it is assumed that the router has not received a locally sourced data packet addressed to the group. Therefore, entries 144L are absent for the group.
According to PIM, if router 110R.3 starts receiving locally sourced data packets addressed to a group before the router's forwarding database is provisioned to forward such packets to non-local group members, the router must encapsulate the packets into unicast packets and forward the encapsulated packets to the RP via unicast transmission. (This is called Register operation.) When the RP receives an encapsulated packet, the RP will send a PIM Join message towards router 110R.3. (This is called "Register Stop".) The Join message will travel to router 110R.4 and then 110R.3, and in response to the Join message the routers will provision their MRIBs and MFIBs to forward the group's data packets to the RP. In particular, router 110R.3 will create entries 144L.2, 144L.3 as in FIG. 3.
MFIB 140F of FIG. 5 is formed from MRIB 140P and IGMP snooping database 140G. MFIB 140F is the same as in FIG. 3 except that it is not provisioned to forward locally sourced data packets to the RP. In particular, in entries 148L.2 and 148L.3, the outgoing interface includes only local VLANs. However, in addition to forwarding the locally sourced packets on the local VLANs, the forwarding plane should be configured to send such packets to the control plane for the Register operation. In some routers, this is accomplished as follows.
First, note on terminology: If an entry such as 144, 148, or 160, has a wildcard for the source address, the entry is sometimes referred to as (*,G). If the source address is specified, the entry is called (S,G). In FIGS. 3 and 5, all the entries are (*,G). There can be multiple entries for the same group and incoming interface, with different source addresses. Routers prefer to forward packets based on (S,G) entries, i.e. the entries having the same source addresses as the packets' SA3 addresses. If there is no matching (S,G) entry for a packet but there is a matching (*,G) entry, then the packet is forwarded based on the (*,G) entry.
In some routers, the Register operation is initiated as follows. Whenever the forwarding plane forwards a packet based on an (*,G) entry, the packet is also sent to the control plane. In the example of FIG. 5, all the IGMP snooping entries 160 are (*,G), and so are the MFIB entries; there are no (S,G) entries. Therefore, when a locally sourced packet arrives, it is forwarded to local group members per an MFIB entry 148L, and in addition the packet is sent to the control plane. The control plane searches MRIB 140P, finds a matching MRIB entry for the packet, and initiates the Register operation.
However, if the IGMP snooping plane includes an (S,G) entry, then the MFIB 140F may include an (S,G) entry 148L for locally sourced traffic. In this case, the Register operation is initiated as follows. Each entry 148 includes an indicator (called a "HIT bit", not shown) indicating whether or not the entry is being used for forwarding a packet. The control plane polls (periodically checks) the HIT bits for all the entries 148L. If for any entry 148L the HIT bit indicates that the entry is used for forwarding, then the control plane checks the MRIB, and if the MRIB is not provisioned for the locally sourced traffic addressed to the group, the control plane instructs the forwarding plane to send the packet to the control plane. The control plane then initiates the Register operation on the packet.
At step 330, a network node 110 (e.g. 110E.10 or 110E.5) sends a multicast packet to the group (i.e. with DA3 address of 220.127.116.11). At step 340, the packet reaches the local multicast router, e.g. 110R.3 or 110R.5. At step 350, the local multicast router forwards the packet to the respective group members per MFIB 140F.
Improved multicast schemes are desirable.

Delayed updating of forwarding databases for multicast transmissions over telecommunications networks


It is an object to provide, in a data storage circuit for storing data, a power saving data storage circuit and a data writing method in the data storage circuit, and, further, to provide a data storage device. Thus, in the present invention, reading out existing data stored in a storage element M is performed prior to performing writing of new data to the storage element M to compare the existing data and the new data. The data storage circuit is configured so that in a case where the existing data and the new data are identical with each other, writing to the storage element M is not performed, and, in a case where the existing data and the new data are not identical with each other, writing of the new data to the storage element M is performed. The data storage circuit is formed on a semiconductor substrate to have a data storage device.

Conventionally, in electronic computers including personal computers, a data storage circuit composed of a combination of a large number of storage elements is provided in a semiconductor device such as a CPU and a memory IC. Data are stored in the data storage circuit so as to execute various types of processing.
The storage elements in such a data storage circuit are normally configured so that 1-bit data is stored in each of the storage elements. More specifically, the storage element is capable of keeping two different states. When one state is represented by "0" and the other state by "1", data of "0" or "1" is stored by keeping any one of the states. A large number of such storage elements are provided to enable the storage of data in an amount corresponding to the number of provided storage elements.
Storage elements having a wide variety of structures are known as such storage elements. For example, a storage element of a flash memory, which consists of a N-channel MOSFET (Metal Oxide Silicon Field Effect Transistor), is capable of storing data "0" and "1" while a state where charges are accumulated in a floating gate layer provided for a gate electrode section is represented by "1" and a state where no charge is accumulated in the floating gate layer is represented by "0" or vice versa.
A storage element of a MRAM (Magnetic Random Access Memory), which consists of a ferromagnetic tunnel junction element, is capable of storing data "0" and "1" while a state where the direction of magnetization of a free magnetization layer is anti-parallel to that of a fixed magnetization layer is represented by "1" and a parallel state by "0" or vice versa.
In a data storage circuit provided with these storage elements, in a case where data of "0" or "1" is newly stored in a certain storage element, a state of change is induced by application of a predetermined voltage to the storage element or by allowing a current to pass therethrough. At this time, the storage element is forced into a predetermined state by application of a predetermined voltage to the storage element or by allowing a current to pass therethrough, regardless of whether existing data that is previously stored in the storage element is "0" or "1", thereby storing new data.
In a data storage device consisting of a semiconductor device including the conventional data storage circuit described above, however, new data is written by application of a voltage to the storage element or by allowing a current to pass therethrough even though the previously stored existing data and the new data to be written are identical. Therefore, there is a problem that substantially ineffective power consumption is generated which hinders power saving.
In particular, the storage element used for the flash memory or the MRAM described above requires a considerable amount of electric power in view of its structure to cause a change of state in order to write new data. Therefore, wasteful power consumption is increased in the data storage circuit, such as the flash memory or the MRAM, by the corresponding amount to further hinder power saving.

Power saving data storage circuit, data writing method in the same, and data storage device


The invention relates to a photographic element comprising a paper base, at least one photosensitive silver halide layer, a biaxially oriented polymer sheet between said paper base and said silver halide layer, wherein said polymer sheet has a thickness of between 13 microns and 65 microns and a Young's modulus of between 700 and 5200 MPa wherein said base paper has a Young's modulus between 1380 MPa and 13800 MPa, a thickness between 75 microns and 200 microns, and an average roughness on the emulsion side of between 0.18 and 0.68 microns and wherein the ratio of thickness between said polymer sheet and said base paper is between 0.1 and 0.5.

In the formation of color paper it is known that the base paper has applied thereto a layer of polymer, typically polyethylene. This layer serves to provide waterproofing to the paper, as well as providing a smooth surface on which the photosensitive layers are formed. The formation of a suitably smooth surface is difficult requiring great care and expense to ensure proper laydown and cooling of the polyethylene layers. One defect in prior formation techniques is caused when an air bubble is trapped between the forming roller and the polyethylene which will form the surface for casting of photosensitive materials. This air bubble will form a pit that will cause a defect in the photographic performance of photographic materials formed on the polyethylene. It would be desirable if a more reliable and improved surface could be formed at less expense.
In color papers there is a need for providing color papers with improved resistance to curl. Present color papers will curl during development and storage. Such curl is thought to be caused by the different properties of the layers of the color paper as it is subjected to the developing and drying processes. Humidity changes during storage of color photographs lead to curling. There are particular problems with color papers when they are subjected to extended high humidity storage such as at greater than 50% relative humidity. Extremely low humidity of less than 20% relative humidity also will cause photographic papers to curl.
In photographic papers the polyethylene layer also serves as a carrier layer for titanium dioxide and other whitener materials as well as tint materials. It would be desirable if the colorant materials rather than being dispersed throughout the polyethylene layer could be concentrated nearer the surface of the layer where they would be more effective photographically.
It has been proposed in U.S. Pat. No. 5,244,861 to utilize biaxially oriented polypropylene in receiver sheets for thermal dye transfer.
It would be desirable if paper base materials could be made smoother. In conventional practice paper base materials are coated with a layer of polyethylene which serves as the base for imaging layers. The method of casting of the polyethylene onto the paper base results in imperfections in the surface onto which the imaging layers are cast. These imperfections are at least the result of the roughness of the paper base material. The paper base has a particularly objectionable roughness in the spatial frequency range of 0.3 to 6.35 mm. This results in a defect usually referred to as orange peel. It would be desirable if this defect in photographic base paper could be minimized or eliminated.
Problem to be Solved by the Invention
There remains a need for photographic papers that have less surface roughness so that the photographic images are glossier and smoother.

Roughness elimination by control of strength of polymer sheet in relation to base paper


Environmental sensors are distributed in a computer system to sense environmental conditions, and the sensors are polled at polling intervals which are adjusted in response to changing environmental conditions, thus allowing deteriorating or improving conditions to be recognized and monitored more or less closely as desired.

Environmental sensors are an important component in modern computer systems, especially high-end servers for commercial and enterprise operations in which reliability is of extreme importance. The environmental sensors are positioned within a computer system to detect environmental conditions that can adversely affect the operation or performance of the computer system. The most common environmental sensors measure temperatures of certain components or at specific locations within the computer system, especially for those components or locations where a large amount of heat is generated or the operation of the system component is relatively sensitive to temperature. Examples of other environmental sensors within the computer system include voltage sensors to sense unacceptable voltages, and fan speed sensors to ensure adequate airflow for cooling.
Heat is generated as a result of conducting electrical currents within various electrical components including semiconductor integrated circuits (ICs), power supplies and other internal components. The amount of heat generated depends upon the type of component and the amount and frequency of current it conducts. A central processing unit (CPU) generates considerable heat because of its constant, very high frequency operation. A power supply, which converts conventional commercial alternating current (AC) power to direct current (DC) power used by the computer components, is usually another significant source of heat. Other components, such as memory ICs, generate relatively moderate amounts of heat due to the more intermittent nature of the electrical currents they conduct. Other components, such as a motherboard which retains many of the significant ICs used in the computer and the temperature sensors associated with them generally represent the overall temperature of multiple grouped components. Other sensors, such as ambient air sensors located on a front panel or backplane of the computer measure the temperature of the ambient air which cools the computer system. An increased temperature of the ambient air diminishes the cooling capacity.
Due to the variable amounts of heat that are generated from the different system components, each component within the computer system that is vital to its continued operation and reliability possesses a dedicated temperature sensor to monitor the temperature or condition of that component. In the event that any of the temperature sensors detects a temperature or condition which exceeds a temperature or condition threshold, the computer system can take the appropriate preventive or remedial action. Each of the environmental sensors produces environmental sensor signals which characterize the current status of the environmental condition sensed by the environmental sensor. The computer system responds to the environmental sensor signals and manages any adverse environmental condition indicated by the environmental sensor signals. Typical responses include logging changing environmental conditions, producing and displaying warning messages about the environmental conditions, and shutting down or turning off the computer system or some portion of it when the environmental condition threatens operation or performance.
A primary consideration for sensing environmental conditions is the technique of supplying signals from the environmental sensors to a central processing unit (CPU) or processor of the computer system which then evaluates the sensor signals and responses to be taken. In one scenario, the environmental sensors continuously provide sensor signals to the processor, but such an approach unduly wastes computational resources. In an alternative scenario in which computational resources are conserved, the environmental sensors provide the sensor signals to the processor intermittently. Two ways of intermittently supplying the sensor signals to the processor are an interrupt routine and a polling routine.
An interrupt routine involves continuously sensing the environmental conditions by the environmental sensors, but the sensor signals are not sent to the processor until they exceed a predetermined threshold which indicates a potentially threatening condition. The computations by the processor are then interrupted and an interrupt service routine is executed to interrogate the environmental sensor, receive the environmental sensor signal, and take an appropriate response.
Because the interrupt routine is event driven, it does not involve transmitting the sensor signals unless a threshold event is detected. In this manner, the interrupt routine conserves computational resources because other processor operations are not delayed unless a potentially threatening condition is detected. However, the interrupt routine requires special hardware, such as separate dedicated interrupt conductors directly connecting each sensor to the processor and threshold determination circuits associated with each environmental sensor to establish the condition under which the interrupt signal is delivered to the processor. Additional conductors linking the environmental condition sensors and the processor are usually difficult and expensive to produce on motherboards where space and connectivity is at a premium.
A polling routine involves continuous sensing of the environmental conditions by the environmental sensors and repetitively "polling" or interrogating and receiving the sensor signals back from the interrogated environmental sensors at a set polling time interval (or polling interval). The polling is conducted over a communication bus which links most of the IC components of the computer system, so no additional conductors are required. Comparing the sensor signals to threshold values is easily accomplished by the processor executed software, thereby eliminating the costs for separate threshold determination circuits associated with each environmental sensor. Initiating an appropriate response is easily integrated with other software controlled actions.
The polling routine is a time interval based routine which occurs repeatedly with a set periodicity regardless of whether or not an adverse condition is detected by the sensor. The polling routine can beneficially provide advanced warning of adverse conditions by monitoring the trends associated with the sensor signals in advance of the actual occurrence of the adverse event. However, the polling routine is inefficient at conserving system resources because of the repetitive nature of the continuous polling of all the sensors.
Many sensed environmental conditions have the potential of changing very quickly and thereby very quickly adversely affecting or threatening the computer system. For example, if a cooling fan on the processor stops operating, or if a heat sink connected to the processor becomes disconnected, the temperature of the processor can rapidly increase to a dangerous level. On the other hand, the ambient air used for cooling the computer system generally does not rapidly increase in temperature. However, the polling routine must be established with a relatively short polling interval to accommodate the critical components having the potential for rapid change, and will inherently consume extra computational resources in the inefficient and needless polling of the less critical environmental sensors at the same high frequency as the more critical components.

Apparatus and method for sensing and responding to environmental conditions of a computer system at non-uniform polling intervals


A modified porous non-conductor is provided wherein its outer and inner, surfaces have been treated by placing the porous non-conductor between a pair of electrodes which are located opposite to each other and carry a dielectric layer on a surface facing the other electrode, respectively, so that the porous non-conductor is brought into contact with both dielectric layers without coming into contact with the electrodes; and then, applying an alternating current voltage having a frequency of about 0.1 Khz to about 100 Khz between the electrodes to thereby induce an electric discharge in voids contained in the porous non-conductor and sandwiched between a pair of the electrodes.

1. Field of the Invention
The present invention relates to a process for treating the outer-inner surfaces of a porous non-conductor or an electrically-non-conductive porous article, and a modified porous non-conductor or a modified electrically-non-conductive porous article. According to the present invention, for example, hydrophilic, hydrophobic or adhesive properties may be imparted to the outer-inner surfaces of a porous non-conductor, such properties may be enhanced, or a roughening of the outer-inner surfaces of a porous non-conductor may be obtained.
2. Description of the Related Art
Hitherto, for example, an alternating current (AC) or direct current (DC) corona discharge, or a low-pressure or atmospheric-pressure glow discharge has been used, when treating a surface of a porous or non-porous non-conductive material with an electric discharge.
In a process using an AC corona discharge, an article to be treated is brought into contact with a surface of a dielectric layer disposed on a counter electrode or an inducing electrode, such as a plane electrode. A discharge electrode, such as a wire or needle electrode, is spaced apart from the article to be treated at a predetermined interval, generally about 1 mm to several millimeters. Then, an AC high-voltage is applied between the discharge electrode and the counter electrode, in air or an other gas, whereby the surface of the article is treated with a linear corona emitted from the discharge electrode. A dielectric layer is generally disposed between the counter electrode and the article to be treated, to stabilize the emitted linear corona. A suitable gas may be selected in accordance with the functional groups to be introduced to the surface of the article. The surface of the article may be also treated, using a DC corona discharge caused by applying a DC high-voltage instead of the AC high-voltage.
In the above process, more than a certain degree of an electric intensity between the discharge electrode and the counter electrode must be produced, namely, a high-voltage sufficient to initiate the corona discharge, to generate the corona discharge. If the voltage applied is too high, however, a spark discharge between the electrodes may occur through weak portions of the article to be treated, to thereby damage the article, for example, by producing large holes therein. When an article having a rugged or rough surface is treated, a uniform discharge cannot be obtained, and therefore, a uniform treatment of the surface is not obtained, and the article may be damaged, for example, by the producing of holes therein. Further, the gas used has a considerable affect on the stability of the discharge. Some gases cannot generate a stable discharge, and thus, the required treatment may not be obtained.
In a process using a low-pressure glow discharge, a pair of electrodes are positioned separate from and opposite to each other in a discharge chamber in which a vaccum has been obtained. The article to be treated is located between the electrodes, and then the pressure of air or other gas in the chamber is reduced to about 10.sup.-2 Torr to about 10 Torr. An AC voltage of generally several kilohertzs (KHz) to several megahertzs (MHz) is applied between the electrodes, to generate a glow discharge, and the surface of the article is treated therewith. In this process, the AC voltage is applied while the article is not in contact with the electrodes or is in contact with only one of the electrodes. Further, intervals between the electrodes will facilitate the discharge under a reduced pressure, as apparent from Paschen's law, and thus the electrodes can be positioned farther apart than those used in the above process using the AC corona discharge. Under a reduced pressure, very little inactivation of ionized chemical species occurs, with a corresponding reduction of the spark discharge. Therefore, more gases may be used, in comparison with the above process using the AC corona discharge.
The process requires a vaccum apparatus to reduce the pressure in the discharge chamber, and thus is not suitable for a continuous treatment. When an article containing volatile materials, such as water or a plasticizing agent, is treated, it is difficult to control the pressure to one suitable therefor. Further, when a porous article is treated using the low-pressure glow discharge, a discharge cannot occur in small pores, such as pores having a pore size of less than 0.1 mm, in the presence of some gases or under some degrees of reduced pressure, in accordance with Paschen's law. Therefore, an article having surfaces with such small pores cannot be treated.
In a process using an atmospheric-pressure glow discharge, as disclosed in, for example, Kogyo-Kanetsu (Engineering Heating), Vol. 27, No. 1, 1990, a pair of electrodes are positioned separate from and opposite to each other at a predetermined distance (generally, several millimeters) in a discharge chamber which may be sealed. An AC voltage of several kilohertzs (KHz) to several tens of megahertzs (MHz) is applied between the electrodes, while a gas mixture containing one or more rare gases, particularly helium, as a main component, with one or more predetermined reactive gases used to introduce one or more functional groups, is supplied into the discharge chamber. The surface of the article is treated by the glow discharge generated between the electrodes. In this process, a dielectric layer is generally disposed on at least one of the electrodes, to stabilize the generated discharge. Further, the AC voltage is applied while the article is not in contact with the electrodes and/or the dielectric layers, or is in contact with only one of the electrodes and/or the dielectric layers.
This process requires an expensive rare gas to produce a stable generation of the discharge. When the amount of the reactive gases used to introduce the functional groups is increased, the discharge becomes unstable, and thus, the amount of the gases that can be used is limited. The gas mixture may generally contain up to about 10% of the reactive gases. In this process, the discharge occurs only at the portion where the gas flows. When a porous article is treated, the reactive gases cannot easily enter voids in the article. Therefore, it is difficult to treat the surfaces of such voids, and thus it is difficult to uniformly treat the outer-inner surfaces of porous article.
Japanese Unexamined Patent Publication (Kokai) No. 4-74525 discloses a process for a treatment using an atmospheric-pressure glow discharge wherein each of the electrodes located opposite to each other is covered with a dielectric layer. In the process disclosed in Kokai No. 4-74525, an AC voltage is applied while the article is not in contact with the electrodes and/or the dielectric layers, or is in contact with only one of the electrodes and/or the dielectric layers. The above-mentioned Publication does not disclose a process wherein an AC voltage is applied while the article is in direct contact with each of the dielectric layers. Further, the process disclosed in Kokai No. 4-74525 is not operative in air but requires the use of an expensive rare gas as a gas for a stable generating of the discharge.
In the process using the atmospheric-pressure glow discharge, the discharge occurs at the portion where the reactive gas flows. Therefore, it is difficult to uniformly treat the outer-inner surfaces of porous article containing voids, because a treating of the surfaces of voids where the reactive gases do not easily enter is difficult to obtain.
Japanese Unexamined Patent Publication (Kokai) No. 7-119021 discloses an apparatus for a discharge treatment using the atmospheric-pressure glow discharge wherein a pair of cylindrical electrodes covered with a ceramic layer (thickness=0.5 to 2 mm) are disposed in parallel. This apparatus requires an expensive rare gas, more particularly, an atmospheric gas containing mainly a gas mixture of helium and argon. In view of obtaining a stable discharge, the gases which may be used to generate a stable discharge are limited, and the concentration of oxygen is preferably 0.5% or less. The apparatus is not operative in air. Further, the apparatus can treat only the portion in contact with the reactive gases. Therefore, it is difficult to uniformly treat the outer-inner surfaces of porous article containing voids, because a treatment of the surfaces of voids where the reactive gases do not easily enter is difficult to obtain.