Abstract: There is described a process for silylizing carbohydrates in liquid nitrogen compounds,the carbohydrates being reacted under pressure in an autoclave at a tempperature of about 0.degree. to 200.degree. C. with a silylizing agent of the formula (I) ##STR1## in a liquid nitrogen compound of the formula (II) ##STR2## the respective radicals in the two formulas (I) and (II) being, independently of each other:hydrogen, a low alkyl group with 1 to 4 carbon atoms, a cycloalkyl group with 3 to 6 carbon atoms, an aryl group in the form of a phenyl or naphthyl radical, an aralkyl group with 7 to 18 carbon atoms, an alkylaryl group with 7 to 18 carbon atoms, or an O-, S- or N-containing heterocyclic group with 2 to 5 carbon atoms.An especially suitable silylizing agent is hexamethyl disilazane. As liquid nitrogen compound preferably ammonia is taken, which under the process conditions is liquid. The process according to the invention is of advantage ecologically and economically.

Abstract: This invention relates to a process for preparing polyurethanes having liquid crystal properties comprising reacting, in proportions corresponding to an NCO/OH equivalent ratio of from about 0.9:1 to 1.1:1, an organic polyhydroxyl compound with an organic diisocyanate having at least two phenylene groups and at least one carboxylic ester group. The organic diisocyanate comprises an aliphatic diisocyanate wherein at least one of the carboxylic ester groups connects an aliphatic group to a phenylene group or an aromatic diisocyanate wherein at least one of the carboxylic acid groups connects two phenylene groups.This invention further relates to preferred diisocyanates used in the process according to this invention.

Abstract: The invention relates to alternating copolymers having the formula ##STR1## wherein one of R.sup.1, R.sup.2, and R.sup.3 in each repeating unit is hydrogen and the others of R.sup.1, R.sup.2, and R.sup.3 in each repeating unit are CN or COOR.sup.5, wherein R5 is C.sub.1 -C.sub.8 alkyl; and n is from 10 to 5,000. This invention further relates to a process for preparing such alternating copolymers by copolymerization of appropriate alkenyl isocyanates and electron deficient olefins.

Abstract: This invention relates to a novel process for the preparation of isocyanates containing silylated alcoholic or phenolic hydroxyl groups as substituents and to the use of the compounds obtained by this process as reactants for isocyanatocarboxylic acid halide in the preparation of polyisocyanates containing ester groups.

Abstract: This invention relates to a process for preparing polyurethanes having liquid crystal properties comprising reacting, in proportions corresponding to an NCO/OH equivalent ratio of from about 0.9:1 to 1.1:1, an organic polyhydroxyl compound with an organic diisocyanate having at least two phenylene groups and at least one carboxylic ester group. The organic diisocyanate comprises an aliphatic diisocyanate wherein at least one of the carboxylic ester groups connects an aliphatic group to a phenylene group or an aromatic diisocyanate wherein at least one of the carboxylic acid groups connects two phenylene groups.This invention further relates to preferred diisocyanates used in the process according to this invention.

Abstract: This invention relates to a novel process for the preparation of isocyanates containing silylated alcoholic or phenolic hydroxyl groups as substituents and to the use of the compounds obtained by this process as reactants for isocyanatocarboxylic acid halides in the preparation of polyisocyanates containing ester groups.

Abstract: This invention relates to a novel process for the preparation of isocyanates containing silylated alcoholic or phenolic hydroxyl groups as substituents and to the use of the compounds obtained by this process as reactants for isocyanatocarboxylic acid halides in the preparation of polyisocyanates containing ester groups.

Abstract: Isocyanates containing ester and/or amide groups are produced by reacting (a) an isocyanatocarboxylic acid chloride with (b) an organic compound containing a silylated alcoholic group and/or silylated phenolic hydroxyl group and/or silylated amino group which compound contains no other group which is reactive with isocyanate and chlorocarbonyl groups under the reaction conditions. The reaction of (a) with (b) is carried out at a temperature of from -20.degree. to 150.degree. C. This process makes it possible to produce the desired isocyanates with a high degree of selectivity.

Abstract: The instant invention relates to a process for the production of polyurethane foams by reacting polyisocyanates with polyhydroxyl compounds of a specified molecular weight range in the presence of blowing agents and chain lengthening or cross-linking agents and optionally in the presence of catalysts, foam stabilizers and other additives generally known. The improvement resides in(a) the polyisocyanates used containing aliphatically and/or cycloaliphatically bound isocyanate groups;(b) the polyhydroxyl compounds used containing ether groups; and(c) the chain lengthening or cross-linking agents comprising at least in part a member selected from the group consisting of a monoalkoxylated hydrazine, a dialkoxylated hydrazine, a reaction product of a monoalkoxylated or dialkoxylated hydrazine with an aliphatic monoisocyanate in a molar ratio of 1:1. The reaction is carried out in the presence of additional chain lengthening agents having a specified molecular weight.

Abstract: The instant invention is directed to a process for the production of a cellular polyurethane elastomer having a density of 0.45 to 0.8 g/cm.sup.3, comprising:(a) preparing a prepolymer having an isocyanate content of 10 to 25% by weight from aromatic polyisocyanates and a portion of one or more polyhydroxyl compounds having a molecular weight of from 400 to 6,000; and(b) reacting said prepolymer with the remainder of said polyhydroxyl compound and water;wherein the quantity of said water is 0.3 to 1% by weight and the equivalent ratio of isocyanate groups to isocyanate reactive compounds is in the range of 0.95:1 to 1.1:1, characterized in that from 0.1 to 0.8% by weight, based on the whole reaction mixture, of aromatic diprimary diamines having a molecular weight from 108 to 500 are also used in (a) or (b).

Abstract: The instant invention is directed to a process for the production of molded foams having a compact surface and cellular core and an integral density distribution over the cross-section of the body, comprising reacting(A) polyisocyanates, and(B) relatively high molecular and/or low molecular compounds having an average of at least two isocyanate-reactive hydrogen atoms in the presence of:(C) catalysts for the isocyanate polyaddition reaction and(D) blowing agents and optionally other known additives, in a closed mold under the conditions of foaming inside molds, the improvement wherein said polyisocyanates are aliphatic and/or alicyclic polyisocyanates and said catalysts are catalyst combinations of:(i) an alkali metal and/or alkaline earth metal hydroxide and(ii) a metal compound, the metal compound being the acetylacetonate of iron, C.sub.1 -C.sub.

Abstract: A process is disclosed for producing polyurethane resins using novel catalysts selected from the group consisting of a process for the production of cellular or non-cellular polyurethane resins comprising reacting:(a) polyisocyanates; with(b) compounds having at least 2 isocyanate reactive hydrogen atoms; in the presence of(c) tertiary amines as catalysts; optionally with the addition of(d) blowing agents, stabilizers and other known additives; characterized in that the substances used as component (c) comprise compounds selected from the group consisting of ##STR1## and mixtures thereof in which formulae: the symbols R may be the same or different and represent straight or branched-chain alkyl groups having from 1 to 4 carbon atoms;the symbols n may be the same or different and represent 2 or 3;the symbols m may be the same or different and represent 2 or 3; andk represents an integer of from 1 to 5.

Abstract: A mucotome or mucous membrane cutter for mucogingival membrane surgery is disclosed. The mucotome comprises a handle having a small, compactly designed cutting head arranged on its forward end, the cutting head including a circular cylindrical blade-holding roller which is reciprocable parallel to the blade edge in a guide by means of a drive shaft having an eccentric crank pin engaging in cross grooves of the blade-holding roller. A cutting shoe is mounted to the ends of the blade-holding roller and is rotatable relative to the cutting head through a limited angle. The cutting head is also selectively positionable in at least two angular positions relative to its support. The cutting blade is secured in a longitudinal radial slot in the roller and projects therefrom through a guide slit formed in a crosspiece of the cutting shoe. The construction and arrangement of the cutting head and cutting shoe assure a compact, versatile structure having a number of adjustment possibilities.

Abstract: A mucotome or mucous membrane cutter for mucogingival membrane surgery is disclosed. The mucotome comprises a handle having a small, compactly designed cutting head arranged on its forward end, the cutting head including a circular cylindrical blade-holding roller which is reciprocable parallel to the blade edge in a guide by means of a drive shaft having an eccentric crank pin engaging in cross grooves of the blade-holding roller. A cutting shoe is mounted to the ends of the blade-holding roller and is rotatable relative to the cutting head through a limited angle. The cutting head is also selectively positionable in at least two angular positions relative to its support. The cutting blade is secured in a longitudinal radial slot in the roller and projects therefrom through a guide slit formed in a crosspiece of the cutting shoe. The construction and arrangement of the cutting head and cutting shoe assure a compact, versatile structure having a number of adjustment possibilities.

Abstract: This invention relates to a process for the production of polyurethane resins (more particularly foam resins) in which linear polyamines containing at least four tertiary nitrogen atoms are used as catalysts. The compounds correspond to the general formula: ##STR1## wherein the groups R, which may be the same or different, represent methyl or ethyl groups; m represents an integer of from 2 to 7; and the integers n, which may be the same or different, represent 2 or 3.

Abstract: The instant invention relates to novel diisocyanato-diketenes, i.e., compounds which contain the isocyanate and diketene groups of the .beta.-lactone type in one molecule, and to a process for the production thereof.