摘要:
A process for preparing polyamides which comprises polymerizing a polyamide-forming compound selected from the group consisting of .omega.-aminocarboxylic acids, .omega.-lactams and an equimolar mixture of a diamine and a dicarboxylic acid and modifying the polyamide formed in the polymerization by incorporating at least one compound of the formula (I) ##STR1## wherein M represents an alkali metal or an alkaline earth metal; n is an integer of 2 to 4; and m is an integer of 2 or more; before, during or after the polymerization.
摘要:
A non-woven fabric usable as a substratum sheet for artificial leather having a relatively high flexural rigidity is prepared by a process in hich fibrous bundles, each consisting of a plurality of extremely fine filaments or fibers having a denier of 0.005 to 0.5, is provided while allowing the filaments or fibers to spontaneously adhere to each other without using an adhesive, the fibrous bundles are massed into the form of sheet or web, and the sheet or web is then subjected to a non-woven fabric forming operation in which the fibrous bundles are entangled with each other.
摘要:
A composite fabric useful as a substratam sheet for artificial leather is composed of a woven or knitted fabric constituent and at least one non-woven fabric constituent consisting of numerous fibrous bundles composed of a plurality of individual fibers arranged parallel to each other, and varying in the number of the individual fibers from which the bundles are formed, and numerous individual fibers independent from each other and from the fibrous bundles, the individual fibers and the fibrous bundles being randomly distributed and entangled with each other to form a body of non-woven fabric, and the non-woven fabric constituent and woven or knitted fabric constituent being superimposed and bonded together, to form a body of composite fabric, in such a manner that portions of the individual fibers and the fibrous bundles of the non-woven fabric constituent penetrate into the inside of the woven or knitted fabric and are entangled with a portion of fibers in the woven or knitted fabric constituent.
摘要:
A method of providing a fibrous thermoplastic resin for depolymerization thereof wherein the fibrous thermoplastic resin is formed into a shaped article having a specific gravity of at least 1/2 of the true specific gravity of the fibrous thermoplastic resin, said shaped article consisting of the fibrous thermoplastic resin mass having on its surface a crusty thin resin layer which may be press-bonded or melt-bonded to the mass. The thus provided shaped article of the fibrous thermoplastic resin can be advantageously employed as a starting material for the depolymerization reaction. In accordance with this invention, the time required for completion of the depolymerization can be greatly shortened as compared with that of the conventional technique and the rate and efficiency of the depolymerization can be greatly improved. Further, according to this invention, fibrous thermoplastic resins can be depolymerized effectively on an industrial scale while automatically conducting unit-operations such as storing, transportation, weighing, and charging into a reaction vessel in much simplified manners.
摘要:
A receiving tray 6 is disposed on a pedestal surface 1a of a base member 1 vertically and movably, while below the pedestal surface 1a are disposed a push-up member 7 interlocked with the receiving tray and a spring 8 for urging the push-up member 7 downwards. A seating surface if for package leads P2 is formed along side portions of the pedestal surface 1a, and a large number of contacts 2 are arranged side by side, the contacts 2 having respective contact portions 2a for contact with the leads P2 which contact portions 2a are urged inwards to obtain a predetermined contact pressure for the leads. There are used movable cams 4 adapted to rotate upon depression of a cover 5 which covers the base member, to displace the contact portions 2a of the contacts 2 outwards away from the package leads P2. The movable cams 4 are each provided with an actuating arm 4c which comes into abutment with the push-up member 7 upon depression of the cover 5 and consequent rotation of the cam 4 to push up the receiving tray 6.