Hoechst Aktiengesellschaft

Az Electronic Materials (luxembourg) S.a.r.l.

Hoechst Celanese Corporation

Hoechst Aktiengellschaft

Hartmut Wiezer

Gerhard Pfahler

Norbert Mayer

Helmut Korbanka

Hans-Dieter Frommeld

Harald Knorr

Klaus Rode

Harald Haberlein

Gunther Nowy

Werner H Mueller

Ulrich Geissler

Franz Scheidl

Debra A Ryan

Hubert Liebe

Josef Ertl

Lars Blankenburg

Sandra Stojanovic

James A Foster

The invention relates polysilazane-containing coatings for increasing the light permeability of sun-facing covers of solar cells. The coating for surfaces contains at least one polysilazane of formula (1) &#x2014;(SiRR'R&#x2033;&#x2014;NR&#x2032;&#x2033;1)n- (1), wherein R&#x2032;, R&#x2033;, R&#x2032;&#x2033; are the same or different or represent an optionally substituted alkyl, aryl, vinyl or (trialkoxysilyl)alkyl group, n being an integer and n being chosen in such a manner that the perhydropolysilazane has a number average molecular weight of 150 to 150,000 g/mol, a solvent and a catalyst. The cured coating has a thickness of at least 0.50-10 micrometer, preferably 0.2 to 5 micrometer, especially preferred 0.5 to 1.5 micrometer. It is especially suitable as transmission-promoting coating for use in sun-facing covers of solar cells.

Polysilazane-containing coatings for increasing the conversion efficiency of encapsulated solar cells

The invention relates to a method for producing passivation layers on crystalline silicon by a) coating the silicon with a solution containing at least one polysilazane of the general formula (1): &#x2014;(SiR'R&#x2033;&#x2014;NR&#x2032;&#x2033;)-n, wherein R&#x2032;, R&#x2033;, R&#x2032;&#x2033; are the same or different and stand independently of each other for hydrogen or a possibly substituted alkyl, aryl, vinyl, or (trialkoxysilyl)alkyl group, wherein n is an integer and n is chosen such that the polysilazane has a number average molecular weight of 150 to 150,000 g/mol, b) subsequently removing the solvent by evaporation, whereby polysilazane layers of 50-500 nm thickness remain on the silicon wafer, and c) heating the polysilazane layer at normal pressure to 200-1000&#xb0; C. in the presence of air or nitrogen, wherein upon tempering the ceramic layers release hydrogen for bulk passivation of the silicon.

Method for producing ceramic passivation layers on silicon for solar cell manufacture

A process for the production of N-acylaminophenols by the concurrent hydrogenation of a nitrophenol to an aminophenol and the acylation of the aminophenol with acyl anhydride takes place on a continuous basis in a stirred tank reactor in which liquid product is continuously withdrawn from the reactor. Of particular interest is the manufacture of acetaminophen, N-acetyl-p-aminophenol by continuous reaction of p-ntirophenol, hydrogen and acetic anhydride.

Process for preparing acyl aminophenols

Radiation-polymerizable composition which comprises

Radiation-polymerizable composition and recording material prepared from

The invention describes a process for stabilizing a leuco-dye solution in an organic solvent against oxidation in air. In the process, a compound containing at least one 2,2,6,6-tetraalkylpiperidine, 2,2-dialkylpiperidine-6-spiro-cycloalkane or piperidine-2,6-dispiro-cycloalkane grouping is added to the solution. The process is, in particular, used for stabilizing photoresist solutions which, apart from the leuco dye, contain polymerizable compounds and photoinitiators, especially radiation-sensitive trihalomethyl compounds.

Process for stabilizing a leuco-dye solution by means of a piperidine

The invention comprises a photopolymerizable mixture comprising as the essential constituents a polymeric binder, a compound capable of forming a polymer by free-radical initiated polymerization, a photoinitiator, a leuco dye and a leuco dye stabilizer having at least one epoxy group. The mixture has a better shelf life in the dark than known compositions and is preferably used in the preparation of dry photoresists.

Photopolymerizable compositions a leuco dye and a leuco dye stabilizer

The reaction for the preparation of 1-oxa-3,8-diaza-4-oxo-spiro[4.5]decane compounds of the formula ##STR1## proceeds more rapidly and more completely if it is performed in the presence of a phase transfer catalyst in an aromatic hydrocarbon which is liquid at room temperature.

Process for the preparation of 1-oxa-3,8-diaza-4-oxo-spiro(4.5)decane

New polyalkyldiazaspirodecanylacetic acid derivatives are prepared by reacting diazaspirodecanes of the formula ##STR1## in which X is ##STR2## with halogenoacetic acid derivatives, and, if desired, reacting products thus obtained further with alcohols or amines. The compounds can be used as light stabilizers for plastics and lacquers.

Polyalkyldiazaspirodecanylacetic acid derivatives, a process for their

Polyalkyldiazaspirodecanes which are substituted in the 2-position by functional radicals and have the formula ##STR1## are prepared from polyalkylpiperidine cyanohydrins and ketones which are substituted by functional radicals. The products are suitable for stabilizing organic polymers against photo-oxidative degradation.

Polyalkyldiazaspirodecane derivatives

Polytriazinylpiperidylamines of the general formula ##STR1## are obtained by reacting cyanuric halides with a monofunctional amino compound and a difunctional amine, it being necessary for at least the difunctional amine to be substituted by a polyalkylpiperidyl radical. The new resinous polymers have a very low volatility. They have an atactic structure and are used to stabilize synthetic polymers towards photoinduced oxidative degradation.

Polytriazinylamines, process for their preparation

New esters and urethanes containing polyalkylpiperidylaminotriazine groups of the formula ##STR1## are prepared from carboxylic acid exters or isocyanates and triazinyl alcohols. The compounds are valuable stabilizers for polymeric materials.

High-molecular esters and urethanes containing piperidine groups, a

Poly-bis-triazinylimides of the formula ##STR1## are prepared from bis-(2,4-dichloro-1,3,5-triazin-6-yl)imides and polyalkylpiperidylamines. They are used as light stabilizers for polymers.

Poly-bis-triazinylimides, their preparation

Halogenophosphazenes of the formula ##STR1## in which n denotes 3 to 100, are reacted with alcohols or amines having polyalkylpiperidyl groups to give compounds which are suitable for stabilizing synthetic polymers and are distinguished by a very high migration resistance.

Phosphazenes useful as stabilizers in polymers

The invention relates to new light stabilizers and heat stabilizers which have a low volatility and are migration-resistant, for use in organic polymers. They are obtained by reacting cyanuric halides with a monoamine containing piperidine groups and a polyamine component.

Triazine stabilizers

Poly-bis-triazinylaminotriazinylamines are prepared from cyanuric chloride, triazinylamines and two different diamino compounds. They are light stabilizers, of low volatility and resistant to migration, for synthetic polymers.

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Gersthofen, Germany

Hartmut Wiezer