摘要:
Butadiene polymers containing 70% or more of 1,2-structure and a relatively low melting point are produced by polymerizing 1,3-butadiene in the presence of a catalyst which has been prepared by admixing (A) an organic solvent solution containing 1,3-butadiene, a cobalt compound and an organoaluminium compound; (B) an amide compound of the formula (2) or (3): ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 are respectively an H atom, aliphatic hydrocarbon radical of 1 to 7 carbon atoms or aromatic hydrocarbon radical of 6 or 7 carbon atoms, R.sub.3 is H or an aliphatic hydrocarbon radical of 1 to 3 carbon atoms and n is 2 to 5, and; (C) carbon disulfide.
摘要:
A process for producing a polybutadiene is provided wherein, first, 1,3-butadiene is polymerized in the presence of a particular cis-1,4-polymerization catalyst and subsequently, the polymerization is continued in the presence of a particular 1,2-polymerization catalyst. The resulting polybutadiene is characterized as containing 2 to 40% of the 1,2-structure, the melting point of the 1,2-structure portion being 110.degree. to 215.degree.C, and containing 60 to 98% of the cis-1,4-structure and having an intrinsic viscosity [.eta.] of 0.9 to 8 in tetraline at 135.degree.C. A vulcanized product of the polybutadiene is characterized as possessing improved tear strength, flex-crack resistance and tensile strength.
摘要:
Disclosed is a sliding member including an overlay layer made of a Bi based alloy comprising Cu as an essential element and at least one element selected from the group of Sn and In, wherein the Bi based alloy comprises 0.1 to 10 mass % of Cu and 0.5 to 10 mass % in total of the at least one element selected from the group of Sn and In.
摘要:
Disclosed is a sliding member having a bearing alloy layer and a composite plating film provided on the bearing alloy layer. The composite plating film is made of a lead alloy containing 0.1 to 10 mass percent in total of copper and 0.3 to 25 volume percent in total of co-deposited inorganic particles. The outermost surface layer of the composite plating film, which has a thickness proportion of 10 to 40% to the entire thickness of the composite plating film, does not contain inorganic particles and copper. The lower layer of the composite plating film contains Cu and inorganic particles, such as Si3N4, dispersed therein.
摘要翻译:公开了一种具有轴承合金层和设置在轴承合金层上的复合镀膜的滑动构件。 复合镀膜由含有0.1〜10质量%的铜和0.3〜25体积%的共沉积无机粒子的铅合金构成。 与复合镀膜的整个厚度相比,厚度比例为10〜40%的复合镀膜的最外表面层不含有无机粒子和铜。 复合镀膜的下层含有Cu和分散在其中的Si 3 N 4等无机粒子。
摘要:
A sliding bearing apparatus having a superior resistance to fretting comprising: a sliding bearing provided with a back metal layer having an inner face and a rear face, and a bearing alloy layer provided on an inner face of said back metal layer; and a housing having an inner face on which said sliding bearing is mounted, the rear face of said back metal layer and/or the inner face of said housing being provided with a coating made of a ceramic.
摘要:
Disclosed is a plain bearing comprising a back metal, a bearing alloy layer provided on the inner surface of the back metal, an intermediate layer provided on the bearing alloy layer and an overlay provided on the intermediate layer. The bearing alloy layer has a textured uneven inner surface, comprising a number of protrusions, which has been formed by etching of the inner surface provided with a mask. A feature and a pattern of the uneven surface can be optionally and accurately formed by designing appropriately the mask. For example, the protrusions may be a form of square, circle or lozenge cross-section, or a ridge extending in an optional direction, e.g. circumferentially, perpendicularly or obliquely to the circumference. After the overlay considerably wears, there will appear a surface state in which the bearing alloy layer, the intermediate layer and the residual soft overlay in the etched recess coexist.
摘要:
Disclosed is a plain bearing having a back metal, a bearing alloy layer and an overlay layer, in which the bearing alloy layer and the overlay layer are formed on the inner surface of the metal in this order. The inner surface of the bearing alloy is provided with circumferential broad width recesses and narrow recesses in which the overlay material is filled. The fatigue resistance and were resistance are ensured by the zone of the narrow width recesses. The plain bearing exhibits high embeddability for a foreign substance by presence of the zone of the broad width recesses.
摘要:
A process for preparing a 2,2,6,6-tetrahalocyclohexaneimine derivative (I) which comprises reacting a 2,2,6,6-tetrahalocyclohexanone with a primary amine or ammonia in the presence of a Lewis acid, a process for preparing a 2,6-dihaloaniline derivative (II) which comprises subjecting the 2,2,6,6-tetrahalocyclohexaneimine derivative (I) to dehydrohalogenation in the presence or absence of a catalyst, and an N-phenyl-2,2,6,6-tetrahalocyclohexaneimine. According to the process of the present invention, the 2,2,6,6-tetrahalocyclohexaneimine derivative (I) can be prepared from inexpensive starting materials in high yield through a few steps. Also, the 2,6-dihaloaniline derivative (II) can be prepared from inexpensive starting materials in high yield and high purity through a few steps. Further, the N-phenyl-2,2,6,6-tetrahalocyclohexaneimine is very useful in the preparation of N-phenyl-2,6-dihaloaniline.
摘要:
A process for preparing a 2,2,6,6-tetrahalocyclohexanimine derivative (I) which comprises reacting a 2,2,6,6-tetrahalocyclohexanone with a primary amine or ammonia in the presence of a Lewis acid, a process for preparing a 2,6-dihaloaniline derivative (II) which comprises subjecting the 2,2,6,6-tetrahalocyclohexaneimine derivative (I) to dehydrohalogenation in the presence or absence of a catalyst, and an N-phenyl-2,2,6,6-tetrahalocyclohexaneimine. According to the process of the present invention, the 2,2,6,6-tetrahalocyclohexaneimine derivative (I) can be prepared from inexpensive starting materials in high yield through a few steps. Also, the 2,6-dihaloaniline derivative (II) can be prepared from inexpensive starting materials in high yield and high purity through a few steps. Further, the N-phenyl-2,2,6,6-tetrahalocyclohexaneimine is very useful in the preparation of N-phenyl-2,6-dihaloaniline.
摘要:
A polybutadiene rubber having an enhanced mechanical strength is produced in such a manner that the content of water in a solution of 1,3-butadiene in an inert organic solvent is controlled to 0.2 to 5 millemoles per liter of 1,3-butadiene; a first polymerization mixture is prepared from the controlled 1,3-butadiene solution, an organic aluminum compound of the formula Al R.sub.n X.sub.3-n, wherein R=C.sub.1-6 alkyl, phenyl, or cycloalkyl, X=halogen, and n=1.5-2.0, and a cobalt compound, for example, by aging a mixture of the controlled 1,3-butadiene solution with the aluminum compound for at least one minute and then by admixing the aged mixture with the cobalt compound; the first polymerization mixture is subjected to a cis-1,4-polymerization; a second polymerization comprising the resultant cis-1,4-polybutadiene, non-reacted 1,3-butadiene, the inert organic solvent, and a catalyst comprising an organic aluminum compound of the formula AlR.sub.3, a cobalt compound, and carbon disulfide is subjected to a 1,2-polymerization to produce a polybutadiene rubber consisting essentially of 5% to 30% by weight of a boiling n-hexane-insoluble fraction and 70% to 95% by weight of a boiling n-hexane-soluble fraction thereof and having an excellent mechanical strength; and after the 1,2-polymerization is shortstopped, the resultant polybutadiene rubber is isolated from the 1,2-polymerization mixture.