Akzo Nobel N.v.

Nouryon Chemicals International B.v.

Cooperatie Koninklijke Cosun U.a.

Akzo Nobel Chemicals International B.v.

Paulus Pieter De Wit

Erwin W Erdhuisen

John Griffiths

Gijsbert Adriaan Van Ingen

Conrardus Hubertus Joseph Theeuwen

Franciscus Adrianus Ludovicus Maria Staps

Martin Bosma

Stephen J Picken

Andre Steenbergen

Johan B Reesink

Kasali A Bello

The present invention relates to methods for processing plant and/or micro-organism derived cellulose materials into rheology/structuring agents. More in particular, the present invention relates to methods wherein plant and/or micro-organism derived cellulose material is co-processed with carboxycellulose. The methods of the present invention provide a variety of benefits, in terms of process efficiency and scalability as well as in relation to the properties of the materials that are obtainable using these methods. For instance, it has been found that (highly) concentrated products produced using the method of the invention are easily (re)dispersible in water and aqueous systems to regain much of the cellulose component's original rheological performance.

Cellulose processing

The invention relates to a dry or slurry process to prepare phosphate-crosslinked cellulose ethers from a cellulose starting material comprising the steps of adding an alkalizing agent to the cellulose starting material to achieve mercerization, adding an ethehfying agent to the reaction mixture to achieve etherification of the cellulose, and adding a crosslinking agent to the reaction mixture to achieve crosslinking of the cellulose, wherein at least part of the alkalizing agent is added to the cellulose starting material before the etherification and/or crosslinking reactions take place to obtain alkalized cellulose; the crosslinking agent and the etherifying agent are added one after the other in random order or simultaneously; the crosslinking agent is an alkali metal thmetaphosphate; and the crosslinking and etherification steps are performed at an elevated temperature. Additionally, the invention relates to crosslinked cellulose ethers obtainable by the above process having a viscosity and/or water absorption capacity higher than their non-crosslinked equivalents and the use thereof.

Process to prepare crosslinked cellulose ethers, crosslinked cellulose ethers obtainable by such process and the use thereof

The invention relates to a dry or slurry process to prepare phosphate-crosslinked cellulose ethers from a cellulose starting material comprising the steps of adding an alkalizing agent to the cellulose starting material to achieve mercerization, adding an etherifying agent to the reaction mixture to achieve etherification of the cellulose, and adding a crosslinking agent to the reaction mixture to achieve crosslinking of the cellulose, wherein at least part of the alkalizing agent is added to the cellulose starting material before the etherification and/or crosslinking reactions take place to obtain alkalized cellulose; the crosslinking agent and the etherifying agent are added one after the other in random order or simultaneously; the crosslinking agent is an alkali metal thmetaphosphate; and the crosslinking and etherification steps are performed at an elevated temperature. Additionally, the invention relates to crosslinked cellulose ethers obtainable by the above process having a viscosity and/or water absorption capacity higher than their non-crosslinked equivalents and the use thereof.

The invention is directed to a liquid crystalline display comprising a display cell containing liquid crystalline material and a retardation layer. The retardation layer comprises a, preferably slightly cross-linked, high-molecular weight material layer and a substrate, wherein the high-molecular weight material has a nematic phase above its Tg and a dynamic viscosity at the working temperature of at least 100 Pa.s. The difference of the Tc of the high-molecular weight material and the Tc of the low-molecular weight material of the display cell (TC.sub.cell) is in the range of -30.degree. C. to +30.degree. C., preferably in the range of -20.degree. C. to +20.degree. C., and more preferably in the range of -10.degree. C. to +10.degree. C.; and the Tg of the high-molecular weight liquid crystalline material is lower than 50.degree. C. It was found that if high-molecular weight material is used with a Tc comparable with that of the, preferably low-molecular weight, liquid crystalline material of the active cell, the temperature dependency of the retardation value of the retardation layer is comparable with that of the active cell. Thus, the retardation value of the retardation layer is comparable with that of the active cell within the temperature range in which displays are used. It was further found that by cross-linking of the high molecular weight liquid crystalline material, the retardation layers according to the invention become less susceptible to pinhole forming and unwanted variation of the twist, and have improved mechanical stability.

Temperature matched retardation layer

Disclosed are liquid-crystalline and infrared-sensitive liquid-crystalline polyesters for optical data storage, processes for the preparation of the same, and an apparatus comprising an infrared-sensitive liquid-crystalline polyester. Owing to covalently bonded dye the liquid crystalline polyester is infrared sensitive and high concentrations of dye are obtainable, without having detrimental effects on the properties of the liquid-crystalline polyester. This results in a highly sensitive liquid-crystalline polyester for optical data storage. Infrared dyes which are preferably bonded in liquid-crystalline polyester are croconium, squarilium, azo, and azamethine dyes.

Liquid crystalline and infrared-sensitive liquid-crystalline polyesters

The invention is in the field of intrinsically thermochromic material. We have found that infrared absorbing dyes of the azamethine type have intrinsically thermochromic properties. The use of said dyes as thermochromic material has the advantage that they can be thermally activated by infrared irradiation. Irradiation of such material with a laser causes a color change that can be used in imaging and optical data storage. The thermochromic dyes can be mixed with polymeric material and from the resulting polymer composition films can be made. If the dye contains polymerizable groups, it may be covalently incorporated into the polymer.

Thermochromic infrared dyes

The invention relates to a liquid-crystalline polyurethane having a side chain comprising a mesogenic group, giving a clear polyurethane which does not isomerize under the influence of light. Such liquid-crystalline polyurethanes are highly suited to be used for optical data storage. The invention further relates to infrared-sensitive liquid-crystalline polyurethanes and liquid-crystalline polyurethane compositions, films containing said liquid-crystalline polyurethanes or polyurethane compositions, and a device for optical data storage containing said liquid-crystalline polyurethanes or polyurethane compositions.

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Westervoort, Netherlands

Paulus Pieter De Wit