Organosilicon compounds (P) containing xcex1,xcex2-unsaturated carboxylic acid radicals, of the general formula (1)

The present invention relates to a process for the preparation of organosilicon compounds (P) containing xcex1,xcex2-unsaturated carboxylic acid radicals, to polymers of the organosilicon compounds (P), to compositions comprising organosilicon compounds (P), and to optically anisotropic layers produced by alignment and polymerization of liquid-crystalline organosilicon compounds (P).
The syntheses and applications of crosslinkable organosiloxanes and organosilanes, in particular siloxanes and silanes containing methacryloyl groups, are described in large number in the literature. Frequently used materials, which are, for example, employed for coatings, are alkoxy-substituted silanes, which, besides the methacryloyl groups, usually also contain methoxy or ethoxy groups. Owing to the relatively low reactivity of the methacryloyl groups, however, the crosslinking density of the polymerized layers produced from these compounds is comparatively low. In many applications, an increase in the crosslinking density could produce better material properties, for example an improvement in the solvent stability, an improvement in the adhesion to the surfaces to be coated, or an increase in the hardness of the coatings. Possible solutions to the preparation of highly crosslinked structures of this type are to increase the number of polymerizable groups, and to use polymerizable groups of higher reactivity than that of the methacryloyl groups, for example acryloyl groups. However, the processes disclosed hitherto for the preparation of such organosiloxanes and organosilanes containing polymerizable groups of high reactivity can only be carried out with difficulty on an industrial scale, or do not give the desired result for reasons associated with the method of production. This is particularly true in the case of acryloyl groups.
It is known that crosslinked organosiloxanes having a liquid-crystalline structure are frequently insufficiently stable to external influences, such as exposure to certain organic solvents. U.S. Pat. No. 5,362,315 discloses, for example, pigments comprising liquid crystalline substances having a chiral phase which are distinguished by the fact that their color depends on the viewing angle. These pigments are employed in various transparent media, such as coatings, binders or plastics. However, EP-A-724005 discloses that when these pigments are prepared from liquid-crystalline organosiloxanes in which the polymerizable groups are exclusively methacryloyl groups, they then, depending on the processing conditions and the medium into which the pigments are incorporated, exhibit color changes which cannot be tolerated in a large number of applications. A solution to this problem, or at least a reduction in its magnitude, can likewise be achieved by increasing the network density of the aligned and crosslinked liquid-crystalline structure.
Various methods are known for the preparation of organosiloxanes and silanes containing methacryloyl groups. A process which is frequently used on an industrial scale comprises the hydrosilylation of di-unsaturated compounds containing double or triple bonds of different reactivity. The aim in this process is for an xcfx89-olefinically unsaturated group to be the target of Sixe2x80x94H attack, while the second unsaturated group is not hydrosilylated. To this end, the reactivity of the group which is not to be hydrosilylated must be lower than the reactivity of the other unsaturated groups. The unsaturated group of lower reactivity is preferably the methacryloyl double bond, but, in principle, the methacryloyl double bond can also be hydrosilylated. In general, more than 10% of side-reactions of methacryloyl groups with Sixe2x80x94H groups take place, the proportion of these side-reactions corresponding to the concentration of the methacryloyl double bonds. In general, the competing hydrosilylation of the two different unsaturated systems thus necessitates that undesired byproducts, for example, dimers, are always produced in such processes, in a proportion which generally depends on the nature of the unsaturated groups and on the manner in which the reaction is carried out.
If the polymerizable groups to be used are xcex1,xcex2-unsaturated carboxylic acid radicals of relatively high reactivity, such as, for example, the acryloyl double bond, the competition with xcfx89-olefinically unsaturated groups is significantly higher than in the case of methacryloyl double bonds under the conditions of the hydrosilylation reaction. Organosiloxanes or silanes containing acryloyl groups are therefore not readily accessible in the manner described above, since the high proportion of side-reactions results in partial crosslinking even during the hydrosilylation reaction, or in the case of siloxanes or silanes containing only one hydrogen atom bonded directly to silicon, in double addition of the siloxane or silane moiety to the di-unsaturated compound. If the organosiloxanes contain mesogenic side groups, the consequent increase in the viscosity usually reduces the mobility of the mesogens so much that a uniformly aligned liquid-crystalline phase can form only with difficulty, if at all.
U.S. Pat. No. 5,211,877 therefore describes, as an alternative method for the preparation of liquid-crystalline organosiloxanes or silanes containing methacryloyl or acryloyl groups, a multistep synthesis in which the methacryloyl or acryloyl group is introduced subsequently, by esterification using a reactive methacryloyl or acryloyl compound after hydrosilylation of a precursor containing a hydroxyl group protected by a protecting group, and subsequent removal of the protecting group. Owing to the large number of reaction steps necessary, however, this method tends to be more practicable for small laboratory syntheses. It is unsuitable for the production of highly crosslinkable organosiloxanes and organosilanes on an industrial scale.
An object of the present invention is to provide a process which can be implemented on an industrial scale for the preparation of crosslinkable organosilicon compounds containing xcex1,xcex2-unsaturated carboxylic acid radicals in high selectivity.
The invention relates to a process for the preparation of organosilicon compounds (P) containing xcex1,xcex2-unsaturated carboxylic acid radicals, of the general formula (1)
xe2x80x94Axe2x80x94Oxe2x80x94C(O)xe2x80x94CRxe2x95x90CH2xe2x80x83xe2x80x83(1),
in which, in a first step,
organosilicon compounds (H) containing hydrogen atoms bonded directly to silicon are reacted with olefinically unsaturated compounds (U) containing a terminal double or triple bond, of the general formula (2)
xcexa9-Oxe2x80x94C(O)xe2x80x94CRHxe2x80x94CH2xe2x80x94Zxe2x80x83xe2x80x83(2),
in the presence of metals or compounds from the platinum group as catalyst, to give organosilicon compounds (E) containing radicals of the general formula (3)
xe2x80x94Axe2x80x94Oxe2x80x94C(O)xe2x80x94CRHxe2x80x94CH2xe2x80x94Zxe2x80x83xe2x80x83(3),
and, in a second step, Hxe2x80x94Z compounds are eliminated from organosilicon compounds (E), where
A is a divalent organic radical,
xcexa9 is a monovalent organic radical containing a terminal double or triple bond,
R is an H atom or a methyl radical, and
Z is Cl, I, Br or 4-methyltoluenesulfonyl.
The process proceeds in high selectivity in both steps and therefore gives very pure organosilicon compounds (P) since the undesired hydrosilylation of the xcex1,xcex2-unsaturated radical xe2x80x94CRxe2x95x90CH2 in the general formula (1), and premature polymerizations caused thereby, are avoided.
The elimination of the Hxe2x80x94Z compounds is preferably carried out by means of a base, such as a tertiary amine, for example triethylamine or tributylamine, or a basic metal salt of an acid, such as, for example, K2CO3, Na2CO3, KHCO3, NaHCO3, Na acetate and KOC(O)C(CH3)xe2x95x90CH2. The Hxe2x80x94Z compound is then chemically bound to the base as a salt.
The organosilicon compounds (H) employed are, in particular, organosiloxanes, which may be linear, branched, or crosslinked organosiloxanes, or which may be in the form of organosilsesquioxanes, or organosilanes.
The organosiloxanes (H) employed are preferably built up from at least 2 identical or different units of the general formula (4)
[HpRlqSiO(4-p-q)/2]xe2x80x83xe2x80x83(4),
in which
R1 is a C1- to C10-alkyl or phenyl radical which is unsubstituted or substituted by halogen atoms, and
p and q each have the value 0, 1, 2 or 3,
where the sum of p and q is at most 3, and in at least one unit per molecule, p has the value 1, 2 or 3.
The organosiloxanes (H) are preferably built up from 2 to 30 units, in particular 2 to 15 units, of the general formula (4). The subscripts p and q preferably each have the value 1 in at least 30% of all units of the general formula (4). Preferred radicals R1 are methyl radicals. Particularly preferred siloxanes of the general formula (4) are cyclotetrasiloxanes, cyclopentasiloxanes, tetra-methyldisiloxanes and linear polymethylsiloxanes preferably having from 4 to 15 silicon atoms and trimethylsilyl groups as end groups.
The organosilanes (H) employed preferably have the general formula (5)
HsSiR2txe2x80x83xe2x80x83(5),
in which
R2 is a halogen atom or a C1- to C10-alkyl or phenyl radical which is unsubstituted or substituted by halogen atoms,
s has the value 1, 2, 3 or 4, and
t has the value 0, 1, 2, 3 or 4,
where the sum of s and t is at most 4.
The subscript s preferably has the value 1 or 2. Particularly preferred silanes of the general formula (5) are those which contain radicals R2 which are either all identical and are each a chlorine atom, or are different and are a combination of one or two halogen atoms and C1-C4-alkyl radicals or phenyl radicals.
Preference is given to compounds (U) in which, in the general formula (2), xcexa9 is R3xe2x80x94A0, where R3 is a monovalent radical of the formula CH2 xe2x95x90CHxe2x80x94(CH2)n or HCxe2x89xa1Cxe2x80x94(CH2)n, in which n is an integer having a value of from 0 to 8, and in which one or more non-adjacent methylene units may be replaced by oxygen atoms or dimethylsilyl radicals, and A0 is a chemical bond or a divalent organic radical.
A0 can be prepared by known processes of synthetic organic chemistry. A hydrosilylatable group can be bonded to A0 by known chemical reactions, such as esterification, condensation, etherification, alkylation, alkenylation, alkynylation or acylation. A0 may additionally be capable of forming an ester bond by virtue of the organic radical A0 being bonded to the divalent oxygen atom of an ester carbonyloxy group.
In a preferred embodiment, the first process step is carried out using compounds (U) in which A0 is (CRH)mxe2x80x94, where m is an integer having a value of from 0 to 12, and R is an H atom or a methyl radical, and where one or more non-adjacent methylene units may be replaced by oxygen atoms, dimethylsilyl radicals, 1,4-substituted phenylene, or cyclohexylene units. The organosiloxanes (P) prepared therefrom are particularly suitable for the production of highly crosslinked coatings and as additives for surface-coating preparations.
In order to prepare liquid-crystalline organosiloxanes (P), mesogenic compounds are hydrosilylated onto the organosilicon compounds (H) in this process.
In a preferred embodiment, polymerizable liquid-crystalline organosiloxanes (P) are prepared. To this end, use may be made, in a first process step, of mesogenic compounds, preferably selected from compounds of the general formula (6)
R3xe2x80x94X1xe2x80x94(A1xe2x80x94X2)dxe2x80x94R5xe2x80x94Oxe2x80x94C(O)xe2x80x94CH(R)xe2x80x94CH2xe2x80x94Zxe2x80x83xe2x80x83(6)
and compounds of the general formula (7)
R3xe2x80x94X1xe2x80x94(A1xe2x80x94X2)dxe2x80x94R5xe2x80x94A2xe2x80x83xe2x80x83(7),
where
R3, R and Z are as defined above,
R5 is a chemical bond or a radical of the formula (CH2)m, in which m is an integer having a value of from 1 to 12, and in which one or more non-adjacent methylene units may be replaced by oxygen atoms or dimethylsilyl radicals,
X1 is selected from a chemical bond and the divalent radicals xe2x80x94Oxe2x80x94, xe2x80x94C(O)Oxe2x80x94 and xe2x80x94OC(O)xe2x80x94,
X2 is a binding member selected from a chemical bond and the divalent radicals xe2x80x94C(O)Oxe2x80x94, xe2x80x94OC(O)xe2x80x94, xe2x80x94CH2CH2xe2x80x94, xe2x80x94CHxe2x95x90Nxe2x80x94, xe2x80x94Nxe2x95x90CHxe2x80x94, xe2x80x94Nxe2x95x90Nxe2x80x94, xe2x80x94C(O)NHxe2x80x94, xe2x80x94NHC(O)xe2x80x94, xe2x80x94Cxe2x89xa1Cxe2x80x94, xe2x80x94CHxe2x95x90CHxe2x80x94, xe2x80x94Nxe2x95x90N(O)xe2x80x94 and xe2x80x94N(O)xe2x95x90Nxe2x80x94,
A1 is a divalent radical selected from six-membered homocyclic or heterocyclic rings, such as 1,4-phenylene, 1,4-cyclohexylene, 2,5-pyridinylene, 2,5-pyranylene, 2,5-pyrimidinylene, 5,2-pyrimidinylene, 2,5-(1,3-dioxanylene) and 5,2-(1,3-dioxanylene), which are unsubstituted or substituted by cyano, fluorine or methyl groups, or from bicyclic compounds consisting of six-membered rings, such as 2,6-naphthylidene, 2,7-naphthylidene and 1,4-naphthylidene,
A2 is an end group selected from hydrogen, halogen, hydroxyl, nitrile, methacryloyloxy, methacryloylethyleneoxy, cholestane, cholesteryl, doristeryl, monofunctional dianhydrohexitol, cyclohexyl and alkenyl radicals having 1 to 10 carbon atoms, in which one or more non-adjacent methylene units may be replaced by oxygen atoms or dimethylsilyl radicals, and
d can have the value 2 or 3.
Preferably, at least 5% of the radicals of the organosiloxanes (P) are prepared by hydrosilylation using compounds selected from mesogenic compounds of the general formula (6) and compounds of the general formula (2) in which A0 is a chemical bond or a divalent organic radical of the above formula (CRH)mxe2x80x94.
Preferably, at least 20% of the radicals of the organosiloxanes (P) are mesogenic radicals. The term xe2x80x9cmesogenic radicalsxe2x80x9d is taken to mean groups which can produce liquid-crystalline properties in a molecule. A regularly updated collection of known mesogenic groups is published by V. Vill et al. as a database entitled LiqCryst (can be purchased from LCI Publisher GmbH, Eichenstr. 3, D-20259 Hamburg).
It has been found that the introduction of the xe2x80x94C(O)Oxe2x80x94 or xe2x80x94OC(O)xe2x80x94 groups as radicals X2 favorably affects the formation of homogeneous liquid-crystalline phases. These radicals are therefore preferred.
Preferred mesogenic compounds (U) of the general formula (6) are the compounds (U) of the general formula (8)
where X2, R5 and Z are as defined for the general formula (6).
In the particularly preferred compounds (U) of the general formula (8), X2 are selected from a chemical bond and divalent radicals from the group consisting of xe2x80x94C(O)Oxe2x80x94 and xe2x80x94OC(O)xe2x80x94, R5 are selected from a chemical bond and C1- to C6-alkyl radicals, and Z is a chlorine atom. R3 is preferably a CH2 xe2x95x90CHxe2x80x94CH2xe2x80x94 group.
In the hydrosilylation, the organosiloxanes (H) containing hydrogen atoms bonded directly to silicon, which are preferably built up from units of the general formula (4) or (5), are reacted simultaneously or successively with a freely adjustable mixture of olefinically unsaturated compounds (U) containing terminal double or triple bonds, of the general formula (2), in the presence of, preferably, at least one metal from the platinum group and/or compounds thereof, where the total number of moles of the olefinically unsaturated compounds (U) corresponds to the total number of Sixe2x80x94H bonds in the organosiloxanes (H), or, in order to ensure complete saturation, an excess of one of the two components (H) and (U) of up to 20% is initially introduced. Suitable hydrosilylation processes are described, for example, in U.S. Pat. No. 5,211,877, U.S. Pat. No. 5,214,077 and DE-A-19541838.
Examples of metals from the platinum group and/or compounds thereofxe2x80x94referred to below as platinum catalystxe2x80x94which can be employed in the process according to the invention are platinum, palladium, rhodium, iridium and compounds thereof, preferably platinum and/or compounds thereof. It is possible to employ all catalysts which have also been employed hitherto for the addition reaction of hydrogen atoms bonded directly to Si atoms onto aliphatically unsaturated compounds. Examples of such catalysts are metallic and finely divided platinum, which can also be on supports such as silicon dioxide, aluminum oxide or activated carbon, compounds or complexes of platinum such as platinum halides, for example PtCl4, H2PtCl6.6 H2O, Na2PtCl4.4 H2O; platinum-olefin complexes, platinum-alcohol complexes, platinum-alkoxide complexes, platinum-ether complexes, platinum-aldehyde complexes, platinum-ketone complexes, including products of the reaction of H2PtCl6.6H2O and cyclohexanone, platinum-vinylsiloxane complexes, in particular platinum-divinyltetramethyldisiloxane complexes with or without a content of detectable inorganically bound halogen, bis(gamma-picolinyl)platinum dichloride, trimethylenedipyridinylplatinum dichloride, dicyclopentadienylplatinum dichloride, (dimethyl sulfoxide)ethyleneplatinum(II) dichloride and products of the reaction of platinum tetrachloride with an olefin and a primary amine, a secondary amine, or both a primary amine and a secondary amine, such as the product of the reaction of platinum tetrachloride dissolved in 1-octene with sec-butylamine, or ammonium-platinum complexes as described in EP-B 110 370.
The platinum catalyst is preferably employed in amounts of from 0.05 mmol to 0.50 mmol, based on the amount of elemental platinum or the platinum compounds used per mole of the Si""H groups present in the siloxane employed. The reaction is preferably carried out at temperatures of from 0xc2x0 C. to 110xc2x0 C. and preferably at pressures of from 0.05 MPa to 1.0 MPa.
The hydrosilylation can be carried out in the presence or absence of solvents, such as hydrocarbons, ethers or esters. If the reaction is carried out in a solvent or solvent mixture, aprotic solvents or solvent mixtures having a boiling point of up to 160xc2x0 C. at about 0.1 MPa are preferred. The individual reactants need not necessarily be soluble in the solvent, since the reaction can also be carried out in a suspension or emulsion. The reaction can also be carried out in a solvent mixture having a miscibility gap if at least one of the reactants is soluble in each of the two phases.
An advantage of this hydrosilylation process is that work-up of the reaction product containing organosilicon compounds (E) is not necessary before the elimination of the Hxe2x80x94Z compounds in the second process step. After completion of the elimination reaction and purification of the organosilanes (P) formed as reaction product, these organosilanes (P) containing hydrolyzable radicals R2 and preferably prepared from silanes of the general formula (5) can be equilibrated and condensed by known processes, as described, for example, in U.S. Pat. No. 5,214,077, to form organosiloxanes (P). In particular, the elimination process can also be used for the production of organosiloxanes (P) having a liquid-crystalline phase.
The organosilicon compounds (P) prepared by the elimination process can be used, for example, for the preparation of highly crosslinked coatings by polymerization, and if these compounds have liquid-crystalline phases, aligned and crosslinked layers having a liquid-crystalline structure can be produced and prepared for various applications. It is also possible to prepare compositions which comprise organosilicon compounds (P) which can be crosslinked to give polymers.
The elimination process enables the production of organosiloxanes and organosilanes (P) having a high concentration of xcex1,xcex2-unsaturated carboxylic acid radicals of high reactivity, such as, for example, acryloyl groups. In the polymerization of these compounds, a high crosslinking density is achieved. The coatings produced therefrom are particularly distinguished by increased hardness, improved scratch resistance and increased resistance to organic solvents.
The liquid-crystalline organosilanes and organosiloxanes (P) prepared by the elimination process can be used for the preparation of highly crosslinked, liquid-crystalline polymers, for which various possible applications are known from the prior art. Owing to their optically anisotropic properties, they are particularly suitable, for example, for the production of optically anisotropic layers, for example optical retardation films, interference pigments and wavelength- and polarization-selective optical filters.
The production of optically anisotropic layers of this type generally requires a uniform alignment of the mesogens in the shortest possible time after application of the layer. Such additional requirements, such as, for example, rapid alignment, which is favored by a low viscosity of the crosslinkable liquid-crystalline polymer, can be achieved more easily by admixing suitable low-molecular-weight components. The organosiloxanes (P) prepared by the elimination process are therefore also used in mixtures with other liquid-crystalline or non-liquid-crystalline materials so long as these additional mixture components do not prevent the formation of the liquid-crystalline phase.
The preferred additional mixture components used are compounds of the general formula (6) and compounds of the general formulae (9) and (10)
R7xe2x80x94X1xe2x80x94(A1xe2x80x94X2)dxe2x80x94R5xe2x80x94A3xe2x80x83xe2x80x83(9),
A4xe2x80x94R5xe2x80x94(X2xe2x80x94A1)dxe2x80x94X1xe2x80x94R5xe2x80x94Kxe2x80x94R5xe2x80x94X1xe2x80x94(A1xe2x80x94X2)axe2x80x94R5xe2x80x94A4xe2x80x83xe2x80x83(10),
where
R5, X1, X2, A1 and d, independently, can be the same or can be different from one another and are as defined for the general formulae (6) and (7),
R7 is selected from the group consisting of acryloyloxy, methacryloyloxy and acryloyl- and methacryloylethyleneoxy radicals and the group of radicals having the formula H2Cxe2x95x90CHxe2x80x94(CjH2j-l), in which j is an integer having a value of from 1 to 8, and in which one or more non-adjacent methylene units may be replaced by oxygen atoms or dimethylsilyl radicals,
A3 is selected from the group consisting of hydrogen atoms, halogen atoms, hydroxyl, nitrile, acryloyloxy, methacryloyloxy, acryl- and methacryloxyethyleneoxy radicals, cholestane radicals, cholesteryl radicals, doristeryl radicals, dianhydrohexitol radicals, cyclohexane radicals and alkenyl radicals having 1 to 10 carbon atoms, in which one or more non-adjacent methylene units may be replaced by oxygen atoms or dimethylsilyl radicals
K is selected from the group consisting of dianhydrohexitol derivatives and in particular dianhydrosorbide or dianhydromannitol,
A4 are identical or different radicals selected from the group consisting of hydrogen atoms, halogen atoms, hydroxyl, nitrile, acryloyloxy, methacryloyloxy, acryl- and methacryloxyethyleneoxy radicals, cyclohexane radicals and alkenyl radicals having 1 to 10 carbon atoms, in which one or more non-adjacent methylene units may be replaced by oxygen atoms or dimethylsilyl radicals.
The invention likewise relates to optically anisotropic layers comprising liquid-crystalline organosiloxanes (P) prepared by the elimination process, or mixtures thereof, both with one another and with other liquid-crystalline or non-liquid-crystalline materials, so long as these additional mixture components do not prevent the formation of a liquid-crystalline phase.
The optically anisotropic layers are preferably produced by a process in which liquid-crystalline organosiloxanes (P) or mixtures containing organo-siloxanes (P) are applied to a substrate, aligned and subsequently fixed by a chemical reaction. The optically anisotropic layers are most preferably produced using liquid-crystalline organosiloxanes (P) prepared from compounds of the general formulae (4), (5), (6) and (7) and mixture components of the general formulae (6), (9) and (10).
The liquid-crystalline organosiloxanes (P) or an LC mixture containing the liquid-crystalline organosiloxanes (P) can be applied to the substrate surface in solution or as a dry substance at above the glass transition temperature of the solvent-free dry substance, for example by spin coating or using a knife coater or roller. If a solvent is used for the application, this must be removed in a subsequent drying step.
The thickness of the dry LC layer on the substrate depends on the requirements of the particular application. If the layer is used, for example, as a retardation plate, the necessary thickness is then the quotient of the optical retardation required and the optical anisotropy of the aligned LC layer. The thickness of the dry LC layer is preferably between 1 xcexcm and 500 xcexcm, particularly preferably between 1 xcexcm and 60 xcexcm,
The application and alignment of the LC mixture can be carried out fully continuously, semi-continuously or discontinuously. A fully continuous process is described in U.S. Pat. No. 5,362,315.
The LC layer can be covered by a second substrate. The mesogens are aligned, for example, by shearing the material during application or, for example, after application through the interaction of the mesogens with the appropriately selected substrate surface(s) or by means of an electric field.
The LC mixture is preferably aligned in a temperature range from above the glass transition temperature to below the commencement of clearing of the particular LC mixture. In order to facilitate a simple industrial process, the composition of the LC mixture is preferably adjusted so that the suitable alignment temperature is between 20xc2x0 C. and 150xc2x0 C.
If the alignment of the mesogens is to take place through an interaction with the substrate surface(s), a suitable alignment layer can, in order to improve the aligning action, be applied to the substrate surface(s) by known coating, printing or dipping processes described in large number in the literature. The alignment layers or the substrates can be provided with a surface structure which favors alignment through additional treatment, for example rubbing. A local change in the alignment direction is possible, for example, by known methods for structuring the alignment layer by means of exposure to polarized UV light. Suitable methods for achieving a tilt between the mesogens of a liquid-crystalline phase and their interfaces are likewise described in the literature, for example the vapor deposition of inorganic materials at an oblique angle. In order to achieve a tilt of the mesogens at an angle of from 10xc2x0 to 80xc2x0 relative to the substrate surface, a layer of silicon oxide is particularly preferably applied by vapor deposition.
Substrates which can be used are all materials which are known for the production of optical elements. Preference is given to organic and inorganic substrates which are transparent or semi-transparent in the wavelength range relevant for the particular application. The substrates can be planar or curved. Particular preference is given to substrates which do not change their physical properties at the production, processing and use temperature of the LC layers.
Very particular preference is given to glass and quartz plates and polymer films, such as, for example, polycarbonates, polysulfones, polyethylene terephthalates, polyimides and cellulose acetates. If necessary, the substrate(s) can be provided with an additional alignment aid, such as, for example, a layer of polyimide, polyamide, polyvinyl alcohol or silicon oxide.
When the alignment is complete, the liquid-crystalline organosiloxanes (P) or the LC mixtures containing these liquid-crystalline organosiloxanes (P) are fixed in the optically anisotropic layers. To this end, the organosiloxanes (P) are crosslinked via the xcex1,xcex2-unsaturated carboxylic acid radicals present in the mesogenic radicals. This crosslinking is preferably effected by means of free radicals generated by peroxides or other suitable thermally activatable free-radical formers, by UV light, by high-energy electromagnetic radiation, or by warming. However, the crosslinking can also be effected by means of crosslinking agents containing hydrogen atoms bonded directly to silicon with catalysis by platinum metal catalysts. It can also take place cationically or anionically. Particular preference is given to the UV light crosslinking described in U.S. Pat. No. 5,211,877 and U.S. Pat. No. 5,214,077.
The resultant fixed layer can be used together with the substrate in the form of a laminate, as a film open on one side, or, after removal of the substrate(s), also as a free film. Preference is given to the use as a film together with the substrate or as a film open on one side.
Another use form of the optically anisotropic layers is as optically anisotropic platelets, which are also referred to hereinbelow as LC platelets. U.S. Pat. No. 5,362,315 discloses how pigments having a liquid-crystalline structure with a chiral phase which reflect light in colors can be prepared by detaching a polymerized cholesteric film from the substrate and subsequently comminuting the rough fragments obtained in this way. The pigments can then be incorporated into a suitable binder system and applied to a substrate. DE-A-196 19 460 describes how platelets having a negative refractive index anisotropy for visible light can be prepared and used by a similar process. The layers described above can likewise be comminuted after crosslinking to give optically anisotropic platelets and subsequently incorporated into a binder and applied to a substrate.
The LC platelets are most preferably produced using liquid-crystalline organosiloxanes and organosilanes (P) prepared by the elimination process from compounds of the general formulae (4), (5), (6) and (7) and mixture components of the general formulae (6), (9) and (10).
Coherent films of the layers of liquid-crystalline organosiloxanes (P) can be employed for all purposes for which the optically anisotropic layers of positive and negative refractive index anisotropy are suitable, for example as optical retarder films for improving the properties of liquid-crystal displays, which are described in large number in the literature. Depending on the choice of substrates and alignment layers and the composition of the liquid-crystalline organosiloxanes (P) and the LC mixtures containing these organosiloxanes (P), it is possible to achieve different forms of alignment, which can advantageously be employed, for example, in liquid-crystal displays, such as TN or STN displays. Examples of possible alignments of the mesogens in the layers are a homogeneous and planar alignment of all mesogens, a hybrid alignment in which the alignment changes continuously from planar to homeotropic from one surface to the opposite surface, a completely homeotropic alignment of all mesogens, a planar alignment which is twisted about the surface perpendiculars, in which the mesogens are aligned, for example, by doping with a chiralic or by means of mutually twisted alignment layers, in a similar manner to in a TN or STN cell, or a cholesteric alignment with a pitch which is less than the wavelength of visible light, which, as described in DE-A-196 19 460, results in a negative refractive index anisotropy.
Further applications can be accomplished through slight modification of the above-described process for the production of the optically anisotropic layers. For example, absorptive polarizing filters can be produced if a mixture is used which, in addition to the liquid-crystalline organosiloxanes (P), also contains suitable dye molecules which align along the mesogens and at the same time do not prevent the formation of the liquid-crystalline phase. Optical storage media, which are based on a local change in the refractive index, can be produced by locally modifying the alignment of the mesogenic radicals of the liquid-crystalline organosiloxane (P) before crosslinking. This can be achieved, for example, by local UV crosslinking through a mask which is opaque to UV radiation if the alignment forces acting from the outside or the temperature of the LC layer are modified between the individual exposure steps. Another possibility is structuring of the alignment layer, as used, for example, in LCD manufacture for the production of sub-pixels.
If the liquid-crystalline organosiloxanes (P) or mixtures thereof either with one another or with other liquid-crystalline or non-liquid-crystalline which do not prevent the formation of a liquid-crystalline phase, contain compounds which induce a chiral nematic phase (chiralics), then these can be used for the production of polarizing and wavelength-selective optical filters or LC platelets.
Cholesteric liquid crystals (CLCs) of this type reflect circular-polarized electromagnetic radiation in a wavelength range which depends on the helical structure of the CLC. The chiralics produce either a right-handed or left-handed twisted structure which reflects circular-polarized light of the same helicity. The central wavelength of the reflection band, which is referred to below as the reflection wavelength, is determined by the refractive index and the pitch of the helical structure, which decreases with increasing concentration of the chiralic. In addition, the reflection wavelength is dependent on the viewing angle.
The width of the band is determined by the optical anisotropy of the mesogenic radicals of the liquid-crystalline organosiloxanes (P) and the other mixture components. In most cases, it is between 5% and 15% of the reflection wavelength. For special applications, suitable measures during film production, as described, for example, in U.S. Pat. No. 5,506,704 and U.S. Pat. No. 5,691,789, allow a varying pitch of the helical structure to be produced, which results in an additionally broadened reflection band.
A large number of suitable optically active dopants are known from the literature. For materials with a left-handed helix, it is often possible to rely on cholesterol compounds, which, in addition to chirality, also introduce good mesogenic properties, for example the cholesterol derivatives disclosed by H. Finkelmann, H. Ringsdorf et al., in Makromol. Chem. 179, 829-832 (1978). A suitable steroid system with a right-handed helix based on cholest-8(14)-en-3-ol (doristerol) or derivatives thereof is described in U.S. Pat. No. 5,695,680. Non-steroidal systems tend to reduce the stability of the liquid-crystalline phase at high concentrations. Examples are the tartarimide derivatives disclosed in U.S. Pat. No. 4,996,330 and U.S. Pat. No. 5,502,206. DE-A-43 42 280 and DE-A-44 08 171 describe crosslinkable monomeric hexitol derivatives and mixtures of monomeric dianhydrohexitol derivatives with other liquid-crystalline compounds which are employed as monomeric dopants for the production of cholesteric networks. DE-A-196 19 460 claims liquid-crystal mixtures which contain liquid-crystalline organosiloxanes and dianhydrohexitol derivatives as chiral additives with a left-handed or right-handed helix. The dianhydrohexitol derivatives described therein are preferably compounds from the group consisting of dianhydrosorbide, dianhydromannitol and dianhydroiditol.
CLC mixtures of this type which contain liquid-crystalline organosiloxanes (P) and chiralics can be used for the production, by the process described above, of layers having a cholesteric alignment which reflect circular-polarized light wavelength-selectively. In these applications, the thickness of the LC layer is preferably greater than three times the pitch, up to a maximum layer thickness of 500 xcexcm. Layer thicknesses of from 1 xcexcm to 50 xcexcm are particularly preferred.
Layers of this type having a cholesteric alignment are highly suitable for decorative applications if the concentration of the chiralics is selected so that the reflection wavelength of the cholesteric band is in the visible wavelength region. Owing to the viewing angle-dependent color impression and the metallic sheen, these layers facilitate special color effects. In applications in security paper printing and trademark protection, good copying protection is additionally achieved owing to these color effects and the polarization of the reflected light.
An example of an optical application is a planar CLC filter, as described in U.S. Pat. No. 859,03 1. CLC filters which reflect in the infra-red region (IR) can be employed, for example, for heat-protection glazing. U.S. Pat. No 5,682,212 discloses how wavelength- and polarization-selective elements which are optically imaging for visible light as far as the near ultra-violet (UV) can be produced on curved substrates using cholesteric liquid crystals. Possible use forms of these optical elements are, for example, beam splitters, mirrors and lenses. The liquid-crystalline organosiloxanes (P) are suitable for the production of optical elements of this type from the IR into the UV region, which is accessible, for example, by using the mixtures described in DE-A-196 19 460.
In some applications of the optically anisotropic layers, it is also possible to use a layer containing LC platelets instead of a coherent film. In this way, the special optical effects of the liquid-crystalline organosiloxanes (P) can be applied with significantly less effort, since the user can utilize conventional printing and coating technologies instead of himself carrying out the more complex production of the films, which requires an alignment and crosslinking operation.
To this end, the LC platelets are incorporated into a suitable binder system, as described, for example, in U.S. Pat. No. 5,362,315 and U.S. Pat. No. 5,683,622. The LC platelets containing liquid-crystalline organosiloxanes (P) containing xcex1,xcex2-unsaturated carboxylic acid radicals of high reactivity, such as, for example, acryloyl groups, are particularly suitable for this purpose since, owing to their high crosslinking density, they have improved stability in the binder.
The requisite properties of the binder systems, in particular the optical properties, also depend on the intended application of the LC platelets. For example, in applications which utilize the polarization- and wavelength-selective reflection of LC platelets containing chiral additives, the binders preferably employed are optically transparent at least in the region of the reflection wavelength. For applications which utilize the optical anisotropy in the region of visible light, preferred binders are colorless and transparent throughout the visible wavelength region.
Preferred binder systems for optical elements are those whose mean refractive index after curing is similar to the mean refractive index of the LC platelets. For the production of durable layers containing LC platelets, curable binder systems are preferably suitable. However, non-curable binders, such as, for example, oils, pastes or thermoplastics, can also be used for specific applications.
Particular preference is given to binder systems which do not alter the physical properties of the LC platelets, or only do so in a defined manner. Examples of suitable binder systems are polymerizable resins (UP resins, silicone resins, epoxy resins), dispersions, solvent-containing or water-based coatings, or all transparent plastics, for example polyvinyl chloride, polymethyl methacrylate and polycarbonate. Besides these isotropic binders, the binder used can also be liquid-crystalline systems, for example liquid-crystalline polymers or polymerizable liquid-crystalline resins, and polymerizable LC silicones. In order to produce a layer or a film having specific optical properties, the LC platelets are stirred into a liquid binder. The alignment of the platelets parallel to the surface of the layer is achieved, as in surface coating with liquid-crystalline colored pigments, for example as described in U.S. Pat. No. 5,362,315, on application of a thin layer of the pigment/binder mixture to a substrate or on extrusion of the mixture. Depending on the requirements of the particular application and the properties of the binder, the film can be detached from the substrate after curing.
The applications of the LC platelets produced can, as in the case of the films, be restricted to pure phase retardation of electromagnetic waves from the ultra-violet to the infra-red region or, if a liquid-crystalline organosiloxane containing chiralics is used for the production of the platelets, LC platelets having a liquid-crystalline structure with a chiral phase which reflect electromagnetic waves of a certain wavelength in a circular-polarized manner can also be produced therefrom, as described in U.S. Pat. No. 5,362,315.
An example of an application of LC platelets is the production of optically imaging, wavelength- and polarization-selective elements on curved substrates, as described in U.S. Pat. No. 5,683,622.
The LC platelets are particularly suitable for decorative purposes if the concentration of the chiralics is selected so that the reflection wavelength of the cholesteric band is in the visible wavelength region. In applications in security paper printing and trademark protection, the viewing angle-dependent color impression and the polarization of the reflected light are additional security features. On simultaneous use of LC platelets having a left-handed and right-handed helical structure, prints can be produced, as described in U.S. Pat. No. 5,599,412, which allow the formation of a three-dimensional image on viewing through polarizing spectacles.
For the production of security marks for protection against counterfeiting of, for example, bank notes, security paper prints, documents or in trademark protection, LC platelets can be employed with particular advantage since they can usually be incorporated with relatively little effort into the printing or other coating processes which already exist in these applications. As marks which are invisible to the human eye, IR-reflective LC platelets, which are obtained at low concentrations of chiralics, or UV-reflective LC platelets, which are obtained at high concentrations of chiralics, are particularly suitable since, owing to their good reflection, they can easily be read by instruments having suitable detectors. For such applications, the LC platelets are preferably transparent and colorless in the region of visible light. The wavelength of the reflection band here is preferably above 750 nm or below 400 nm. Besides the reflection wavelength, the circular polarization of the reflected radiation can be detected as an additional security feature. For this application, the CLC platelets are preferably incorporated into an IR- or UV-transparent binder for application to a substrate to be marked.

Preparation of organosilicon compounds containing xcex1, xcex2-unsaturated carboxylic acids

Abstract: xe2x80x94Axe2x80x94Oxe2x80x94C(O)xe2x80x94CRxe2x95x90CH2 xe2x80x83xe2x80x83(1),

Abstract: are prepared by a process in which, in a first step, organosilicon compounds (H) containing hydrogen atoms bonded directly to silicon are reacted with olefinically unsaturated compounds (U) containing a terminal double or triple bond, of the general formula (2)

Abstract: A is a divalent organic radical,

Abstract: R is an H atom or a methyl radical, and

Consortium fur Elektrochemische Industrie GmbH


A positive electrode active material for a nonaqueous electrolyte secondary battery contains a first lithium-metal composite oxide represented by General Formula: Lis1Ni1-x1-y1-z1Cox1Mny1Mz1O2+α and containing a secondary particle formed of a plurality of flocculated primary particles and either one or both of a first compound containing lithium and boron and a second compound containing lithium and tungsten. Either one or both of the following characteristics (1) and (2) are satisfied: (1) the first compound covers surfaces of the primary particles, and a boron content is at least 0.01% by mass and up to 0.5% by mass relative to the entire positive electrode active material; and (2) the second compound covers the surfaces of the primary particles, and a tungsten content is at least 0.01% by mass and up to 1.0% by mass relative to the entire positive electrode active material.

In recent years, with the proliferation of portable electronic equipment such as cellular phones and notebook personal computers, development of a nonaqueous electrolyte secondary battery with reduced size and weight having high energy density is intensely demanded. Development of a secondary battery excellent in output characteristics and charging/discharging cycle characteristics is intensely demanded as a battery for electric vehicles including hybrid cars.
A positive electrode active material for a nonaqueous electrolyte secondary battery is a secondary battery satisfying such a demand; a lithium-ion secondary battery is a representative secondary battery. This lithium-ion secondary battery includes a negative electrode, a positive electrode, and an electrolyte solution, in which for active materials of the negative electrode and the positive electrode, materials that can de-insert and insert lithium are used.
Among lithium-ion secondary batteries, the research and development of which are currently energetically being conducted, lithium-ion secondary batteries containing a layered or spinel type lithium-metal composite oxide as a positive electrode active material can obtain as high voltage as 4 V class and are thus being practically used as batteries having high energy density.
Examples of the positive electrode active material that have been so far mainly presented include a lithium-cobalt composite oxide (LiCoO2), which is relatively easily synthesized; a lithium-metal composite oxide (LiNiO2) and a lithium-nickel-cobalt-manganese composite oxide (LiNiv3Co1/3Mn1/3O2) containing nickel, which is lower in price than cobalt; and a lithium-manganese composite oxide (LiMn2O4) containing manganese.
To further improve charging/discharging cycle characteristics, containing lithium excessively than a stoichiometric composition relative to metal elements such as nickel, cobalt, and manganese is effective, for example.
By the way, a positive electrode of a nonaqueous electrolyte secondary battery is formed by mixing the positive electrode active material, a binder such as polyvinylidene fluoride (PVDF), and an organic solvent such as N-methyl-2-pyrrolidone (NMP) together to make a positive electrode mixture paste and applying the positive electrode mixture paste to a collector such as aluminum foil, for example.
When the positive electrode mixture paste is produced, lithium may be released from the positive electrode active material in the positive electrode mixture paste, react with water contained in the binder and the like, and form lithium hydroxide. The formed lithium hydroxide and the binder react with each other, and the positive electrode mixture paste may gelate. Gelation of the positive electrode mixture paste brings about bad operability and worsening of yield.
Given these circumstances, some attempts to inhibit gelation of the positive electrode mixture paste are made. Patent Literature 1 presents a positive electrode composition for a nonaqueous electrolyte solution secondary battery containing a positive electrode active material containing a lithium-transition metal composite oxide and additional particles of acidic oxide particles, for example. It is said that in this positive electrode composition, lithium hydroxide formed through a reaction with water contained in a binder preferentially reacts with the acidic oxide to inhibit a reaction between the formed lithium hydroxide and the binder and to inhibit gelation of a slurry for a positive electrode. It is also said that the acidic oxide plays a role as a conductive material within the positive electrode, reduces the resistance of the entire positive electrode, and contributes to improvement in the output characteristics of the battery.
Patent Literature 2 presents a method for producing a lithium-ion secondary battery including preparing a lithium-transition metal oxide containing LiOH outside its composition as a positive electrode active material;
grasping a molar amount P of LiOH contained per 1 g of the positive electrode active material; preparing tungsten oxide in an amount of at least 0.05 mol in terms of tungsten atom per 1 mol of LiOH relative to the molar amount P of LiOH; and kneading the positive electrode active material and tungsten oxide together with a conductive material and a binding agent with an organic solvent to prepare a positive electrode paste.
Patent Literature 3 presents a positive electrode composition for a nonaqueous electrolyte solution secondary battery containing a lithium-transition metal composite oxide essentially containing nickel and tungsten and a boron compound containing a boron element and an oxygen element. It is said in Patent Literature 3 that using the positive electrode composition containing the lithium-transition metal composite oxide and the specific boron compound can improve the output characteristics and cycle characteristics of the positive electrode composition containing the lithium-transition metal composite oxide and inhibit an increase in the viscosity of a positive electrode slurry.

Positive electrode active material for nonaqueous electrolyte secondary battery, method for producing the same, positive electrode mixture paste for nonaqueous electrolyte secondary battery, and nonaqueous electrolyte secondary battery


The invention provides a superconductor comprising particles made of a superconductive material, and a conductive material. The conductive material is selected to be driven to a superconductive state when in proximity to the superconductive material, and preferably at least includes gallium. An unbroken length of the conductive material is located sufficiently close to a plurality of the particles to be driven to a superconductive state by the superconductive material.

1). Field of the Invention
The present invention relates to a superconductor.
2). Discussion of Related Art
The discovery of high critical temperature (Tc) superconducting ceramics (HTS ceramics) has inspired an enormous interest in their application. Conventional niobium alloy superconductors such as NbTi must be cooled to below 10K to achieve useful superconductivity. HTS superconductors, on the other hand, can have Tcs over 100K. Due to the great expense of cryogenic refrigeration, the HTS ceramics could find much wider application in industrial and laboratory devices. Of particular interest are materials which have Tc above 77K, because this is the temperature of liquid nitrogen, a common and relatively inexpensive refrigerant.
HTS ceramics have not been used in many potential applications because they suffer from a number of shortcomings. The most severe problems with the HTS ceramics are as follows:
1) HTS ceramics are brittle. They are not flexible and thus cannot be made into wires or other useful shapes. Cracks and boundaries between adjacent crystals severely limit supercurrent flow.
2) HTS ceramics are highly anisotropic. Supercurrents preferentially flow in certain directions with respect to the crystal lattice, reducing the maximum current density in randomly oriented multicrystalline pieces.
3) HTS ceramics are strong oxidizing agents. Most metals, such as copper, lead, tin, aluminum, indium, and niobium, are oxidized by contact with the ceramic superconductors. Insulating oxide layers impede supercurrent flow. Only noble metals such as gold, silver palladium and their alloys are not oxidized by the HTS ceramics.
A less severe undesirable feature of the HTS ceramics is that they can lose their superconducting properties under certain circumstances. The superconducting structure inside the HTS ceramics has an abundance of oxygen atoms which are necessary for superconductivity. Heating, grinding, etching, or prolonged exposure to ambient atmosphere or vacuum may liberate the oxygen and destroy superconductivity. Both the oxygen content and the superconductivity can be restored by annealing the HTS ceramic in an atmosphere of oxygen.
It would be an advance in the art of applied superconductivity to provide a superconducting wire employing HTS ceramics that is ductile, has a high Tc, and has a high critical current density (Jc). Such a wire must overcome the problems with the HTS ceramics. Prior art HTS ceramic wires made of a combination of HTS ceramic particles in a silver matrix generally have poor superconducting properties such as low Jc. Also, bending the prior art wires tends to greatly reduce the Jc. This is highly undesirable.
There are other ceramic superconductor materials which have some of the same disadvantages as HTS cuprate materials. For example, the A15 family of superconductors such as Nb3Sn are also brittle materials (although they are not anisotropic and relatively nonreactive). Their poor mechanical properties have precluded their use in many applications requiring ductility such as wires. This is unfortunate because they generally have good superconducting properties such as relatively high Tcs, high critical magnetic fields, and high critical current densities.
Other examples of brittle, nonductile superconductors include materials possessing the NaCl crystal structure (the AB family), Laves phase ceramics, Chevrel phase ceramics, and metallic borides. These materials may have superior superconducting properties, but are unusable in many applications (e.g., conducting wires) because they are brittle. It would be an advance in the art of applied superconductivity to provide flexible wires made from brittle superconductor materials.
U.S. Pat. No. 5,091,362 to Ferrando discloses a method for forming a silver coating on HTS ceramic particles. U.S. Pat. No. 4,971,944 to Charles et al. teaches a method for electroless deposition of gold onto HTS ceramic particles.
U.S. Pat. No. 5,041,416 to Wilson describes a superconducting composite material. Powders of HTS ceramic and normal metal are mixed and the mixture is subjected to heat and high pressure. The composite materials of Wilson have a relatively low Jc due to reactivity between the HTS ceramics and the metal matrix. The wires also have a low Jc if silver is used as the normal metal.
U.S. Pat. No. 5,202,307 to Hayashi describes a superconducting composite material having HTS ceramic particles in a metal matrix. The composite materials of Hayashi have a relatively low Jc due to reactivity between the HTS ceramic particles and the metal matrix and/or due to poor superconducting properties of the metal matrix materials.
U.S. Pat. No. 5,194,420 to Akihama describes a composite cuprate superconductor/metal superconducting material consisting of HTS ceramic particles dispersed in a matrix of silver. The composite materials of Akihama will also have a relatively low critical current density due to the choice of silver as the metal matrix material.
U.S. Pat. No. 5,081,072 to Hosokawa et al. describes a method preparing a HTS superconducting ceramic powder and forming the powder into a superconducting material. A low Jc is also a problem with the materials of Hosokawa.
U.S. Pat. No. 5,547,924 to Ito et al. describes a superconducting ceramic composite material having HTS ceramic particles in a noble metal matrix. The composite materials have relatively poor superconducting properties due to the poor superconducting properties of the metal matrix materials used.
U.S. Pat. No. 5,132,278 to Stevens et al. describes a cuprate superconductor wire having continuous filaments of HTS ceramic surrounded by metal matrix. A noble metal chemically protects the HTS ceramic. The wires of Stevens et al. are characterized in that they do not conduct current between wires, and do not rely on the superconducting proximity effect.
There exists a need for the HTS ceramic superconducting material that is ductile and has a high Jc that is not reduced by bending. Also, there exists a need for ductile superconducting materials made from brittle superconductors that have a high Jc high Tc, and high ductility.


In order to design a motor chain saw with a chain brake device releasable as a back kick brake and as a coasting brake comprising a tension lever (2), movable with respect to the housing of the motor chain saw, which can be moved between a brake position (B) and a ready position (b), a release lever (19) which can take up a coasting brake position (A) and a disengaging position (f), in combination with a supplementary brake device known as a coasting brake, it is proposed that the tension lever (2) is placed linearly slidingly movable with respect to the housing of the motor chain saw and that the release lever (1) is placed slidingly movable with respect to the tension lever (2), whereby both axles of the sliding movement are parallel to each other.

This invention relates to a motor-driven chain saw with a chain brake device releasable as a back kick brake and as a coasting brake comprising
a tension lever movable with respect to the housing of the motor chain saw which can be moved between a brake position and a ready position,
a release lever movably placed on the tension lever which can take up a coasting brake position and a disengaging position,
a Bowden cable the actuation of which causes a relative movement of the release lever and of the tension lever against the action of the restoring force of a spring member,
a brake which is operatively connected with the release lever in such a way that the saw chain is released only when the tension lever is in the ready position and the release lever in the disengaging position.
Motor chain saws with a so-called back kick brake are known by the prior art since a long time. For these saws, the run of the saw chain is stopped for safety reasons when a dangerous situation takes place. Such a dangerous situation is generally recognized or defined in that a jerk movement takes place with a high acceleration of the saw (back kick). Due to its inertia of mass, the hand-guard releases the brake device for the saw chain. Such a release can also take place directly by manually actuating the hand-guard.
The braking of the saw chain takes place by a brake device generally in such a way that a brake band which winds round a coupling drum is tightened and thus the rotation of the coupling drum is stopped by friction. The coupling drum is connected free of rotation with a chain wheel which drives the saw chain.
The brake device can also be actuated independently from the back kick brake with a supplementary brake device known as a coasting brake in a second way.
The coasting brake is to avoid that the saw chain coasts for a certain time (typically for a few seconds) after having disconnected the drive because of the inertia of mass of the drive. This coasting can cause namely a damage of the saw chain when laying down the device. Moreover, the coasting constitutes an endangering potential for the user of the saw. A coasting brake is useful and necessary independently of the fact if it is a motor saw with an electric motor or an internal combustion engine. The actuation of the coasting brake is generally coupled with the gas pedal to be actuated by the user or with the locking key with which the gas pedal can be stopped. This means that, when pulling through the gas pedal (xe2x80x9cstepping on the acceleratorxe2x80x9d), the coasting brake is disengaged so that the saw chain can rotate. Inversely, when releasing the gas pedal, the brake is immediately actuated and the run of the saw stopped. A coupling of the coasting brake functions similarly with the locking key. The coasting brake is released only when the locking key is pressed.
The aim of this invention is to work out a motor chain saw with the brake device mentioned in the introduction in combination with a supplementary brake device known as a coasting brake. The design priority should be a compact construction and a high safety of function.
This aim is achieved by the characteristics indicated in claim 1.
The brake device of the motor chain saw thus has a construction consisting of a tension lever, a release lever, a Bowden cable and a brake of the type explained in the introduction and known from the prior art. According to the invention, it is characterized in that the tension lever is placed linearly slidable with respect to the housing of the motor chain saw and that the release lever is also placed linearly slidable with respect to the tension lever, the two mentioned movement axles of the displacement being appropriately parallel to each other.
This has the advantage that a compacter construction can be achieved since no space is necessary for providing long lever arms. Moreover, the linearity of the movements allows that the tension lever and the release lever can be placed at least partially in the inside of the spring(s) so that there is a further gain of space. The whole mechanism obtains a longish extension which can be surrounded by a protective housing in a simple way. This reduces the susceptibility of the mechanism to troubles from outside and thus contributes to a higher reliability of the brake system.
In a further development of the invention according to claim 2, the tension lever is pressed by a spring member into the brake position. When the tension lever is in the brake position, the saw chain is not disengaged, i.e. it is braked. Due to the effect of the spring member, the brake device thus tends to take up the safe position in which the saw chain is braked. Furthermore, due to the effect of the spring member, it is guaranteed that already low forces can be sufficient to release the back kick brake since the main energy is made available by the spring member for moving the tension lever.
A brake device of the last mentioned type with a spring member on the tension lever can be further developed according to claim 3 so that the tension lever is held in the ready position by an articulated lever connected with the hand-guard of the motor chain saw against the pressure of the spring member. An articulated lever is an element substantially consisting of two segments, whereby the segments are connected with each other over a hinged articulation. The segments can be moved into an extended position in which the angle of the articulated lever is 1800 or slightly more and a further extension is avoided by a stopper. This extended position of the articulated lever is stable against axial forces of pressure, a relatively low force onto the knee link in vertical direction to the articulated lever axle can however cause the collapse of the articulated lever. The articulated lever can thus be used in the extended position to held the tension lever in the ready position against the high force of the spring member. A relatively low force transmitted by the hand-guard to the articulated lever can then however cause the collapsing of the articulated lever so that the tension lever can move under the action of the elastic force immediately and unhindered from the ready position into the brake position. A stop of the saw chain is thus achieved by the brake.
Moreover, the above described connection of the tension lever with a spring member can be further developed according to claim 4 so that the release lever which is in a disengaging position, fixed to the tension lever but linearly movable is operatively connected with said spring member. For example, the release lever can have a direct contact with the spring member. This construction measure has the advantage that in the disengaging position of the release lever the force of the spring member can be directly transmitted to the release lever. Should it thus come to a release of the back-kick brake with which the force of the spring member is released, this force can act directly and without intermediate elements onto the release lever and thus onto the brake. Additional time delays due to the intermediate elements are avoided here. Furthermore, the safety of the system is increased since the intermediate elements are avoided as possible sources of error.

Motor-driven chain saw with back kick brake and coasting brake


The invention relates to a porous material comprising particles of polymer P assembled by a block copolymer, said block copolymer comprising at least one block consisting of a polymer sequence immiscible with polymer P, and at least two blocks consisting of polymer sequences which are miscible with polymer P. The invention also relates to films produced with this material.

A nanometric-scale organization of the active layer of filtration membranes is increasingly sought in order to better control their selectivity while at the same time maintaining great permeability.
Polyvinylidene fluoride (PVDF) is a polymer of choice for producing such membranes, owing in particular to its good mechanical strength and its resistance to chemical attacks.
Since PVDF is hydrophobic, it offers a high water resistance. For this reason, document WO 2010/051150 describes polymer membranes consisting of a PVDF-based polymer matrix, blended with an amphiphilic block copolymer, in order to increase the hydrophilic nature of the matrix. In this document, the PVDF is intimately blended with the block copolymer.
Document WO 2014/139977 describes an improved version of this technology, in which use is made of particular block copolymers comprising a hydrophilic first block which can be obtained from n-butyl acrylate and hydroxyethyl methacrylate monomers, and a hydrophobic second block of poly(methyl methacrylate) type.
There is still a need to provide a material which makes it possible to produce membranes having a precise and uniform pore size, where appropriate with a desired surface functionalization. There is also a need to reduce the amount of solvents consumed during the production of such a material. There is also a need to be able to apply such a material to various supports.

Porous films obtained from polymer latex


A rigid replica of a flag of the United States consists of a background, a field and a plurality of emblems, the background comprising individual U-shaped channels comprising colored red and white horizontal stripes, the field comprising a solid blue panel and the emblem comprising a white star, the channels affixed to spaced apart vertical rafters, the rafters forming a frame of the rigid flag replica, the channels alternately uprightly and invertedly disposed whereby an exposed surface of the uprightly disposed channels is disposed at a different elevation than an exposed surface of the invertedly disposed channels, the uprightly and invertedly disposed channels providing depth and definition to the exposed surface of the rigid flag replica, the blue field having 50 white stars affixed thereto in rows and columns, the blue field applied to the horizontal stripes in an upper left hand corner, the blue field overlying the red and white horizontal stripes.

1. Field of the Invention
This invention relates to a rigid flag replica of any nation, organization, state, individual, family, entity or signal flag by arranging a plurality of alternately uprightly and invertedly parallel U-shaped channels horizontally upon a frame whereby an exposed surface of the uprightly disposed channels is disposed at a different elevation than an exposed surface of the invertedly disposed channels.
2. Prior Art Statement
Government standards indicate that a typical cloth flag will last approximately 90 days based on daily usage during daylight hours only. This assumes there will not be inclement weather. Flags flown 24 hours a day may only last one fourth as long. There are also expensive time and maintenance issues involved with cloth flags. Perhaps the most costly item involved with a cloth flag is the cost and installation of a flag pole as the flag pole often costs more than the sum of the flags purchased over an organization's life time.
Planar flags painted upon a flat surface such as building walls or roofs or parts thereof are known to the inventor. Also known to the instant inventor are planar flag decals which may be affixed to a flat surface. For instance, aluminum plate frames with waving flags applied thereto may be found at various decal shops or on the internet site of AutoPlates. Other substantially planar flag appliques may be found at the internet site of CaseArts. Some decal flags have curved stripes to give the appearance of waving, however, the appearance does not change for passersby as no depth nor definition is present in planar flags. Furthermore, planar flags cannot change appearance with respect to oblique lighting. Painted or decal planar flags are also subject to rapid weathering and must be replaced or repaired often. Therefore, there is a need for a rigid flag replica which is low in maintenance, has depth and definition, changes appearance with respect to passersby and/or with respect to oblique lighting and can be constructed of various materials to be assembled on site.
It is known to provide a rigid display board comprising spaced rigid vertical metal frame members, horizontally adjacently arranged sheet metal channel shaped card holders having the webs thereof imposed upon the frame members and secured thereto to provide a generally rectangular rigid structure. For instance, see the U.S. Pat. No. 1,964,484 issued on Jun. 26, 1934, to Theodore E. Schroeder. The display board of Schroeder does not have a background, a field and a plurality of emblems nor are the channels alternately disposed in upright and inverted fashion and therefore, the display board of Schroeder cannot be used to display a flag having raised and lowered surfaces to give an appearance of waving to passersby. Therefore, there is a need for a rigid replica of a flag which has the below described novel features.
It is also known to provide a program display board comprising supporting means including upper and lower rails, a plurality of board units slidably mounted on and between the rails wherein the boards have parallel ribs protruding from one face thereof adapted to receive a plurality of visually distinctive markers snapped over one of the ribs and engaged in a channel between the ribs. For instance, see the U.S. Pat. No. 3,419,979 issued on Jan. 7, 1969 to McVicker, et al. The markers must be stacked one upon the other on each rib and thus could not have a background, a field and a plurality of emblems wherein the background comprises alternately disposed upright and inverted channels. Thus, the program display board of McVicker, et al., cannot be used to display a flag of an organization, nation, state, individual, family or other entity. Therefore, there is a need for a rigid replica of a flag which has the below described novel features.
It is further known to provide a sign board of rigid extruded shallow channels having concave sidewalls. The concave sidewalls are snap-fitted over convex shaped clips of a mounting panel, and when so arranged, provide a planar surface for the sign board. For instance, see U.S. Pat. No. 4,059,914 issued on Nov. 29, 1977 to Dobson. All the channels of Dobson have the same planar face facing outwardly and thus cannot have alternately disposed upright and inverted channels on the same face. Thus, the need for a rigid replica of a flag which has these and other novel features still exists.
Also known in the art is a signage system comprising a frame and at least one removable plate-shaped lettering insert, the frame including a vertical support plate with a horizontal mounting flange which receives the plate-shaped lettering insert thereover. For instance, see the U.S. Pat. No. 4,344,244 issued on Aug. 17, 1982 to Charles R. Tyke. The signage system has plate-shaped lettering inserts across the entire face thereof and thus the entire face does not have alternately elevated and depressed surfaces thereupon. Accordingly, this signage system cannot be used to display a flag of various nations, organizations, states, individuals, families or other entities. Hence, there is a need for a rigid replica of flags of different countries having alternately elevated and depressed surfaces. Similar cumulative U.S. Patents are U.S. Pat. No. 5,224,610 issued on Jul. 6, 1993 to Veazey and U.S. Pat. No. 5,718,072 issued on Feb. 17, 1998 to Garfinkle.
Finally, it is known to provide a metal awning comprising a plurality of pan channels having upwardly directed flanges and a plurality of cover channels having downwardly directed flanges, the pan and cover channels arranged in parallel, alternate, overlapping relation and joined together at the flanges thereof to produce a corrugated top structure. For instance, see the U.S. Pat. No. 2,619,691 issued on Dec. 2, 1952 to J. R. Bottom. The awning produced thereby has found utility as a window or door covering to shield the window or door from the elements, however has not heretofore been utilized for other purposes as the awning comprises only parallel cover and channel pans of certain colors and does not have a separate field applied thereto nor emblems of the entity displayed thereon.

Rigid flag replica and methods of making the same


A hinging mechanism attaching an access panel to a housing is provided that has a latching device rigidly mounted to the inner surface of the panel and releasably pivotally secured to the interior surface of the housing, whereby the panel is detachable from the housing and free to move between open and closed positions. Preferably, the mechanism further includes a linkage member movably mounted to the interior surface, whereby the mechanism has articulation at independent points between the housing and the panel. The mechanism is also preferably one where the latching device includes a latch-bracket and a latch, the latch being pivotally attached to the latch-bracket.

Many electrical appliances and area lighting fixtures include housings that hold a number of the electrical components needed to operate the device. Such housings typically have a hinged access panel that give skilled personnel access to the equipment inside the housing for purposes of performing regular service and needed repairs on the apparatus. These housings have, however, a number of problems and shortcomings.
There are many occasions where access into certain housings is prevented by the presence of adjacent and abutting structures that obstruct and interfere in the full or even partial opening of the access panel. Physically detaching the panel from the housing is one solution but doing so may be quite strenuous since it will often involve removing fasteners and other hardware from the hinging mechanism to disassemble it from the housing. Moreover, removal of the panel can also be dangerous since the individual needing access to the housing may oftentimes perform this work from the top of a ladder.
If the housing is located outdoors and the hinging mechanism itself is mounted on the exterior of the housing, the hinging mechanism may also be exposed to the elements, leading to corrosion and other damage that will make opening and closing of the access panel difficult.
Quite apart from the harm created by the weather, access to the inside of many housings may often be difficult and time consuming because of their inconvenient location. Certain area lighting fixtures are, for instance, typically high in the air. The problems in working on such devices are compounded by the fact that, even with the access panel in its fully opened position, reaching into the housing to access all areas inside can still be awkward and frustrating.
This invention addresses these problems and shortcomings in a simple and inexpensive manner.

Detachable hinging mechanism for access panel


In a paper feeding apparatus, a paper feeding unit has a paper mounting surface provided with an air-blowing outlet. The paper feeding structure feeds an uppermost sheet of a stack of paper on the paper mounting surface. An air pump supplies air to an air-blowing outlet, a first air-blowing member and a second air-blowing member. The air-blowing outlet is so provided as to blow air to an approximately whole undersurface of the paper stacked on the paper mounting surface. When air is being supplied to the air-blowing outlet, an electronic control unit inhibits the feeding of sheets of paper by the paper feeding unit.

1. Field of the Invention
The present invention relates, generally) to a paper feeding apparatus and, more specifically, to an apparatus for feeding the uppermost sheet of paper from a stack of paper.
2. Description of the Related Art
Laid-open Japanese patent publication number H05-319669 discloses an example of a multi-functional document integrating apparatus that carries out post-processing such as bookbinding. The apparatus of the '669 publication achieves such post-processing by successively taking out the uppermost sheet of paper from a stack of paper loaded on a tray. Such an apparatus requires the advance stacking of sheets of paper on the tray in the order of processing that will follow.
When stacking sheets of paper on such a tray, it is difficult to place them in the correct horizontal position that assures proper feeding of the uppermost sheet of paper. For example, where the sheets of paper are stacked by various types of paper stacking apparatuses, the stacked position of sheets on the tray may vary with the paper stacking apparatuses and the sizes of the sheets of paper whereby it may be all the more difficult to stack the sheets in correct position. Hence, it is a general practice that after the sheets have been stacked on a tray, the user manually shifts the stacked sheets of paper to a position appropriate for paper feeding. A user generally shifts the stacked sheets of paper to a position appropriate for paper feeding after the sheets have been stacked on a tray.
There often occurs friction between the stacked paper and tray, however, when the stacked sheets of paper are moved in a horizontal direction. This friction makes it difficult to move the slack of paper horizontally while retaining the form of the stack. As such, there is a need in the art to overcome such difficulties.

Paper feeding apparatus for feeding sheets of paper


A vibration damper for a motor vehicle with a support spring, includes a damper tube with a longitudinal extension axis A, a spring disk, a protective insert, and a protective accordion boot which has a first end portion and a second end portion, wherein the protective accordion boot is secured at least indirectly to a piston rod by its first end portion, and wherein the protective accordion boot encloses damper tube in circumferential direction by its second end portion. The protective insert has at least one radially outwardly extending supporting portion, wherein the protective accordion boot is axially supported by the second end portion thereof at the supporting portion of the protective insert accompanied by a defined axial pre-loading, and wherein, with respect to the longitudinal extension axis A of the damper tube, the supporting portion extends radially beyond the inner diameter d of an end coil of support spring supported at the spring disk.

1. Field of the Invention
The present invention is directed to a vibration damper for a motor vehicle including an accordion boot and a protective insert.
2. Description of the Related Art
DE 10 2010 063 101 A1 discloses a generic vibration damper which has a damper tube with a longitudinal extension axis (A), a spring disk, a protective insert and a protective accordion boot. The spring disk has a tubular spring disk collar surrounding a damper tube in circumferential direction. The spring disk further has a contact portion spaced apart axially from the spring disk collar, a support spring being axially supported at the substantially plate-shaped radial extension of the contact portion. With its disk-shaped portion, the protective insert covers the surface of the contact portion of the spring disk facing the support spring. The spring disk collar is covered by the tubular portion of the protective insert. The protective accordion boot surrounds the damper tube in circumferential direction, one end of the protective accordion boot being axially supported at the protective insert.
When the vibration damper is under heavy stress, for example, when driving over potholes, it cannot be ruled out in view of the relatively small difference in diameter between the outer diameter of the protective insert and the inner diameter of the protective accordion boot in the shared contact area that the protective accordion boot will slip over the protective insert and come in contact with the support spring. If this were to happen, the protective accordion boot would rub against the spring during compression and/or rebound of the vibration damper and would damage the corrosion-resistant coating, which would inevitably lead to premature corrosion and breakage of the support spring.
In view of the set of problems mentioned above, it is an object of the present invention to further develop a vibration damper so as to prevent rubbing contact between the protective accordion boot and the support spring.


The object of the present invention is that the surplus vibration involved therewith simultaneously generating a sound wave by the vibration of the vibrating cone of the loudspeaker unit is generated in the loudspeaker system, which has impaired the sound quality of the loudspeaker system. The purpose of the present invention is to provide a technique for improving the sound quality by reducing the this surplus vibration which are the loudspeaker frame vibration and the cabinet vibration like a front baffle vibration. The present invention is characterized in being configured with a viscoelastic material layer upon rear portions such as the frame surface of the loudspeaker unit and inside and outside surfaces of each surface configuring the loudspeaker cabinet, and additionally suppresses vibration by addition of a heavy member or pressurization caused by constraint of a binding member.

Common loudspeaker equipment is shown in FIG. 22 in full-range loudspeaker unit use and an enclosure formal cabinet, furthermore FIG. 23 shows generating of sound and the vibrational state of a loudspeaker unit and the vibrational state of the cabinet by vibration of the vibrating cone of a loudspeaker unit, and the direction of an arrow of the figure is shown in the state in case the vibrating cone operates ahead by plus polarity, and FIG. 24 shows the schematic drawing the vibration propagation process. The loudspeaker system is established by the vibrating cone anteroposterior vibration of the loudspeaker unit by Fleming's left-hand rule between the magnetic field of the loudspeaker magnet and the magnetic field of the voice coil of the loudspeaker input signal, on the base of the stationary point of the non-vibration, and, thereby, a realistic reproduction sound of high resolution can be obtained. Especially for this high resolution, there is also a historical background needs of high-resolution sound that has been growing in an era of image is high resolution and has become a full high-definition video.
However, the loudspeaker unit of the loudspeaker system is a vibration generator, sound emission by the vibration of the loudspeaker vibrating cone is a purpose, and the loudspeaker frame and the all panels of the cabinet should be a stationary point of the non-vibrating, but the vibrating cone unit vibrates vibration accompanying occurs with adverse effect these vibrations are superimposed on the generated sound from the vibrating member of the loudspeaker unit direct sound emission from a cabinet is also made. With the sound generation of the air vibrations P1 forward due to vibration of the loudspeaker vibrating cone SPa, the vibration of the loudspeaker frame SPd through the loudspeaker damper SPb or loudspeaker edge SPc is generated specifically, the loudspeaker cabinet according to the frame vibration P3 of the front baffle 1a occurs. By complex of the air transmission of the rear air vibration P2 due to the vibrating cone vibration of the loudspeaker unit, and the solid propagation of the vibration of the front baffle, the surplus vibration P4 each side of the cabinet 1b•1c•1d occurs further. In addition to these, the resonance by the cabinet wall reflection is added, the vibration P5 flocks to vibrating cone backside of the loudspeaker unit again, then it makes the surplus vibration to the vibrating cone SPa, and the sound passes through the vibrating cone SPa. There is a vibration P6 of the reverse phase of the magnet side by the action and reaction of the vibration of the vibrating cone SPa of the loudspeaker unit in addition to this, this is work in momentum conflicting back and forth movement of the vibrating cone. The loudspeaker system serves as a sound generation, including also the variety surplus vibrations, and these caused the superimposition of distortion and sound masking fine sound to the air vibration P1 forward due to vibration of the vibrating cone SPa, therefore a fundamental and comprehensive solution for the removal of surplus vibration of all these is requiring.
For the cabinet and the loudspeaker unit is a two major elements of the loudspeaker system, proposal of material structure and many have been made so far, is an example of the loudspeaker cabinet to suppress the vibration by forming a reinforcing rib of the mountain-shaped cabinet rear panel vibration reduction of the cabinet (see for example, Patent Document 1), there is produced a composite baffle plate which inserted a viscoelastic sheet having airtightness large vibration damping effect a loudspeaker cabinet to suppress, such as rubber (see for example, Patent Document 2). The suppression of vibrations radiation consists of laminate obtained by laminating damping alloy (see for example, Patent Document 3), and resin plate box, and wood brittle material stone, concrete, ceramic, with silica fume mortar, plastic, and viscosity, such as iron, and further there is cabinet combined the toughness and material or elastic material, is constructed by interlacing particle board and filament winding (see for example, Patent Document 4). Further example, is an example of viscous material in the cabinet, a large number of forms a porous air chamber by an elastic structure inside the cabinet as the use of an elastic material, filled with viscous material, volume increasing effect and sound absorption some purposes even but elastic structure use, of the viscous structure is also conducted (see for example, Patent Document 5). As for the frame of the loudspeaker unit, the suppression of vibration have sought, providing a reinforcing rib reinforcing the frame has also been (see for example, Patent Document 6). However, in a schematic diagram of the process of propagation of the vibration shown in FIG. 24, for the deformation of each place and vibration propagation emanating from the loudspeaker unit that occur at the same time sound comes out at the start of the first vibration, the current situation is hardly addressed comprehensively and fundamentally.
The adverse effect of vibration P5 coming from the cabinet, the adverse effect of action and reaction vibration P6, and the adverse effect to the vibrating cone due to the elasticity resistance with an air capacity of cabinet, for these three adverse effects, the analysis is further described. The additional vibration P5 to the back surface of the vibrating cone of the loudspeaker unit by the vibration of the cabinet wall and reflected sound from the cabinet wall is a big factor, as a means for reducing this, of the shown in FIG. 25, in the prior art arrangement are placed back and forth for the two loudspeaker units SP1 and SP2, is driven with the same phase to form a common sound chamber 6, isolate the adverse effects of the cabinet is known. Thus, in addition to eliminating the vibration of the rear vibrating cone to isolate the effect of the cabinet in common sound chamber 6, for two loudspeakers to operate in the same phase, the rear loudspeaker unit forms the state that is easy to vibrate for front loudspeaker unit SP. By two vibrating cones to operate in the same phase polarity, the common sound chamber is the noise cancellation state, regarded the cabinet vibration as a noise, at the same time in this state, it is also possible to see the back assist states of the vibrating cone operation of the front loudspeaker unit by the rear loudspeaker unit. Thus, if two of three adverse effects are manufactured enough in consideration of rigidity and a vibration suppression, it will go towards solution, however, in this arrangement, it has not been solved about the vibration P6 by the side of the loudspeaker magnet by the action and reaction of vibration of the vibrating cone of a loudspeaker unit, and also since two loudspeaker units operate in the same direction for the same volume, the action and reaction vibration P6 increases. There is a back-to-back arrangement for the two loudspeaker units to offset the solution of the vibration caused by the action and reaction, and there is a arrangement to emit a sound outside for both loudspeakers (see for example, Patent Document 7), and there is a arrangement to emits a sound inside of a cabinet for one side loudspeaker (see for example, Patent Document 8). The action and reaction vibration P6 headed in the direction of resolution, the arrangement to make this back-to-back will bring forward the playback of sound fine if you manufacture in consideration to damping, however, for the additional vibration P5 to the back surface of the vibrating cone of the loudspeaker unit and the vibrating cone vibration caused by the elasticity of the air cabinet, the adverse effect reduction has not been made.
Therefore, for the purpose of solving both at the same time, there is suggestion to be shown in FIG. 26. In the back-to-back two loudspeaker units operated in the same phase polarity, so offsetting the vibration of the magnet according to action and reaction, it is guided by the sound path from the rear portion sound of the front loudspeaker unit SP1 to the vibrating cone front portion of the rear loudspeaker unit SP2, sound path although the diffraction, to form a common sound chamber 6 between SP2 and SP1, as well as before and after arrangement of the loudspeaker in FIG. 25, and it is what led to the cabinet from the vibrating cone rear portion sound of the rear loudspeaker unit SP2 further (see for example, Patent Document 9). By the loudspeaker placement of back-to-back, the offset reduction of action and reaction vibration P6, due to the formation of common sound chamber 6 and isolation of the additional vibration P5 by cabinet due to noise cancellation state of common sound chamber 6, back assist by the rear loudspeaker unit has been conducted, if production in consideration to the damping and stiffness, the improvement of reality by the reproduction of the sound clear and crisp sound reproduction of the fine is confirmed.


The use of a class of non-azo 1,8-naphthalimide dyes for the detection and quantitation of a paramagnetic metal cation in a non-aqueous medium and some of the dyes that will complex with a paramagnetic metal cation. The concentration of the paramagnetic metal cation is determined by monitoring differences in the detected fluorescent emission spectra of the non-azo 1,8-naphthalimide dye solution when it is mixed with paramagnetic metal cations present in the non-aqueous medium. The detected fluorescent emission spectra will vary in relation to the presence or amount of the paramagnetic metal cation in the mixture.

In any mechanical system, moving parts are subjected to wear. Despite the fact that mechanical systems are designed and lubricated in an effort to minimize wear, wear will always exist. It is important to be able to assess engine wear and avoid unpredicted equipment failure. The presence of an excessive amount of wear metal in an engine's lubricant indicates either lubricant failure or an impending mechanical failure of the system.
Spectrometric oil analysis programs (SOAP) can serve to identify problem areas before the loss of equipment to catastrophic failure by monitoring the concentration of wear metals suspended in an engine's lubricant. The success of the SOAP system is attested to by the required routine analysis of the lubricants of all aircraft and military mechanical systems. In addition, voluntary lubricant analysis is commonplace in fleet vehicles.
At present atomic emission methods are used to detect metal ions for military samples. The advantage of this methodology is that it can detect 21 elements (Fe, Cr, Cu, Ni, Mn, Ag, Al, Mg, Pb, Si, Na, Sn, Ti, V, Cd, Ca, P, B, Mo, Zn, and Ba) in the 1-1500 ppm range simultaneously. Problems associated with this methodology are: Its inability to detect metals in particles larger than 10 microns; the expense of the equipment required; the instability of the atomic absorption spectrophotometer's flame when testing hydraulic fluids; and the inability to assign oxidation levels to any wear metals present in the oil.
There are two major components to wear in any mechanical system, mechanical wear and corrosive wear. Mechanical wear is simply the scraping of metal particles from a surface while corrosive wear is the oxidation of metal on the surface giving a species that easily crumbles from the surface often without mechanical contact. Magnesium alloys are particularly sensitive to corrosive wear. Atomic admission spectra detect fine metal particles, colloidal suspensions, and discrete ions to the same extent. Lacking the speciation between these forms of the metals precludes the assessment of wear due to corrosion and that due to mechanical abrasion.
Based on the foregoing, a need has arisen for a faster, less expensive, more accessible method of oil analysis that would be practical for both large and small fleets of vehicles.

Non-azo 1,8-naphthalimide dyes for the detection and quantitation of a paramagnetic metal cation in a non-aqueous medium