摘要:
A process of producing a perfluorocarboxylic acid fluoride having the formula (1): ##STR1## wherein n is an integer of at least 2, comprising effecting oligomerization of hexafluoropropylene oxide in the presence of an alkali metal fluoride a sulfone or a mixture of a sulfone with an ether having the formula (2):CH.sub.3 O(CH.sub.2 CH.sub.2 O).sub.m CH.sub.3 (2)where m is an integer of 2 to 6. This process makes it possible to improve production yield of hexafluoropropylene oxide oligomers remarkably, and to raise a reaction temperature for the oligomerization, as compared with conventional methods, thereby shortening reaction time therefor.
摘要:
Fluorinated organic silicon compound of the general formula: ##STR1## wherein R is an alkyl group having 1 to 6 carbon atoms, n is an integer of from 1 to 6, and m is equal to 1, 2 or 3 are novel and useful as treating agents and intermediates for the synthesis of fluorinated cyclic organic silicon compounds. The fluorinated organic silicon compounds are prepared by reacting a chlorosilane with a fluorinated olefin.
摘要:
In a ring network system comprising a plurality of nodes, each node is provided with a node information table which is logically divided into node areas each corresponding to a single node within the ring network. Each node collects node information stored in the node information tables of the two adjacent nodes by regularly accessing the node information tables of those nodes, and updates the contents of its own node information table. As a result of the above information collecting operation that is performed by each node, all the node information can be stored in the node information table of each node.
摘要:
Oligohexafluoropropylene oxide derivatives represented by the general formula (I): ##STR1## wherein R.sub.f represents a perfluoroalkyl group having 1 to 10 carbon atoms and n is an integer of 0 to 100 or the general formula (II): ##STR2## wherein R.sub.f ' represents a perfluoroalkylene group having 2 to 10 carbon atoms and a and b are each independently an integer of 0 to 20. These compounds are novel and are useful as intermediates for synthesizing iodine-containing oligohexafluoropropylene oxides useful as raw materials for fluororesins, fluororubbers, and fluorine-containing surfactants.
摘要:
The present invention provides a heat-curable fluorosilicone rubber composition to be cured by hydrosilation reactions and having outstanding physical properties, especially improved transparency and processability, said composition comprising(A) a polydiorganosiloxane having at least two unsaturated aliphatic hydrocarbon groups and represented by the general formula (1):R.sub.a.sup.1 SiO.sub.(4-a)/2 ( 1) wherein R.sup.1 represents a substituted or unsubstituted monovalent hydrocarbon group containing 0.01 to 15 mole % of an unsaturated aliphatic hydrocarbon group, a is a positive number of from 1.95 to 2.05.(B) a polyorganohydrogensiloxane having at least three hydrogen atoms directly bonded to silicon atoms in a molecule and represented by the general formula: ##STR1## wherein R.sup.2, R.sup.3 and R.sup.4 independently represents a substituted or unsubstituted monovalent hydrocarbon group, X represents CF.sub.2 or C.sub.3 F.sub.6 O, b is equal to 2 or 3, c is equal to 1 or 2, b+c=3, m is an integer of 2 or more, n is an integer of 1 or more, and k is an integer of 2 or more,(C) a silica filler having a specific surface area of at least 50 m.sup.2 /g, and(D) an addition reaction catalyst.
摘要:
In a method of mounting and demounting at least two, upper and lower dies to and from a press molding machine, a workpiece is inserted into a press position between the upper and lower dies. The workpiece is then pressed or stamped at the press position by the upper and lower dies. The upper and lower dies are maintained at the press position to leave the workpiece after having been pressed or stamped, at the press position between the upper and lower dies. The upper and lower dies are mounted and demounted to and from the press molding machine, with the workpiece maintained at the press position between the upper and lower dies.
摘要:
A process of producing a silethylene oxide represented by the following general formula (1): ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 each represent a hydrocarbon group having 1 to 8 carbon atoms such as a methyl group, comprising the steps of thermally decomposing the hydrolyzate of 1,4-dichloro-1,1,4,4-tetrahydrocarbyl-1,4-disilabutane in the presence of an alkali, bringing the thermally decomposed product in contact with carbon dioxide and distilling the reaction mixture. According to this process, in the distillation, since polymerization or formation of 2,5-disilahexane-2,5-diol can be obviated, a purified silethylene oxide can be obtained in high yield. Further, the distillation apparatus will not be clogged with by-products.
摘要:
An organosilicon compound having the general formula (I): ##STR1## wherein R.sup.1 represents the methyl group or the ethyl group, R.sup.2 represents an alkyl group having from 1 to 4 carbon atoms, and n represents an integer of from 1 to 3. This compound is useful in preparing room temperature vulcanizable organopolisiloxane compositions which have good storage stability, and release no smelly or corrosive condensation by-product on curing.
摘要:
A pattern inspection system for inspecting a pattern formed on a base, such as a photomask, by means of laser beam scanning which includes a device for detecting the body and edges of the pattern, a memory device having a plurality of memory units for separately storing the detected body and plurality of edges of the pattern, a device for measuring the width of the body of the pattern between two parallel edges of the pattern, a device for detecting and correcting missing pattern edges, a device for inverting the pattern, a device for reducing the pattern, and a device for eliminating pinholes and stains within the pattern.