Abstract: The present invention provides a flexible metal-clad laminate obtained by directly applying a polyimide precursor to a metallic conductive foil, and then drying, heating and curing the precursor to form a polyimide film, this flexible metal-clad laminate being characterized in that the polyimide film is composed of two or more polyimide layers, the linear thermal expansion coefficient of at least one of the second and later polyimide layers is larger than that of the first layer brought into contact with the metallic conductive foil, and the requirements of the following formulae are met:3.0<Q.sub.n-1 .times.t.sub.n <50,t.sub.n-1 >t.sub.n and ##EQU1## wherein t.sub.n is the thickness (.mu.m) of the outermost layer (the nth layer) of the polyimide layers, t.sub.n-1 is the thickness (.mu.m) of the film comprising the first layer to the (n-1)th layer of the polyimide layers, and Q.sub.

Abstract: A silicon-modified, adhesive polyimide film composed mainly of the repetition units of the formula (I) and a process for producing a polyimide film composite product using the above film are provided, the formula (I) being ##STR1## the above process for producing a polyimide film composite product comprising subjecting the above-silicon-modified polyimide film to contact-bonding on heating to a material to be adhered, at an ultimate curing temperature of 130.degree.-230.degree. C.The above polyimide film is highly adhesive and heat-resistant in spite of heating at a relatively low temperature.

Abstract: The present invention provides a process for producing molded articles of a polyimide precursor by a use of a usual extrusion technique, and physical properties of polyimide products prepared by the heat treatment of the molded articles of the polyimide precursor at 400.degree. C. are excellent. This process is characterized by drying a solid obtained by pouring a dilute solution of a polyimide precursor including an aromatic tetracarboxylic acid component and an aromatic diamine component 1 into a liquid in which the precursor is only poorly soluble to obtain a dry solid having a polyimide precursor concentration of 50-70% by weight, and then extruding this dry solid at 80.degree.-130.degree. C.

Abstract: A method for producing circuit boards with a film having improved printing properties, adhesion, flexibility and heat resistance which comprises applying a liquid printing ink composition comprising an admixture of a solvent, a polyamide-acid and a partially imidized polyamide-acid, then heat to effect drying and curing.

Abstract: A flexible copper-applied substrate comprises a copper foil and a resin layer comprising a composite material of a polyimide and a polyimide silicone, the resin layer being directly formed on the surface of the copper foil, said substrate being producible by applying a polyamide acid composite composed of a mixed solution of a polyamide acid and a polyamide acid alkylsilane to a copper foil and heating.

Abstract: A flexible double-sided copper-clad printed-circuit base board is provided with a core resin layer of a composite material essentially composed of a specific rigid-structured polyimide and a specific flexible-structured crosslinked polyimide silicone in a state of being inseparable from each other, wherein the core resin layer is formed directly between two copper foils. This base board is produced by coating a surface of a copper foil with a polyamic acid solution mixture of a specific polyamic acid and a specific polyamic acid - alkylsilane, heat-treating the resulting coated copper foil, and contact-bonding another copper foil to the resulting copper-foil/polyimide laminate.

Abstract: In a process for producing a flexible printed base by directly coating a copper foil with a polyimide precursor, followed by heating, drying and curing, a process affording a flexible printed base having a superior folding endurance and a good heat resistance at a cheap cost is provided, which process comprises carrying out the curing in an inert gas under a tension of 0.02 to 0.2 Kg/cm and at 200.degree. and 450.degree. C.

Abstract: A polyimide having a low elastic modulus and also superior heat resistance and mechanical characteristics and soluble in solvents and a process for producing the same are provided,which polyimide comprises as main components, 60 to 99% by mol of repetition units of the formula (I) and 1 to 40% by mol of repetition units of the formula (II) ##STR1## wherein Ar is a tetravalent aromatic group; X and Y are at least one group bonded to phenyl group at o-position relative to N atom and selected from 1-4C alkyl, CO group or OH group; R.sup.1 is a 3-5C divalent alkyl or phenylene; R.sup.2 is 4 or less C alkyl or phenyl; l and m are each 1 to 4; and n is 20 to 300, andwhich polyimide is produced by reacting diamino compounds consisting of 60 to 99% by mol of an aromatic diamine of the formula (V) and 1 to 40% by mol of a silicone diamine of the formula (VI), with an aromatic tetracarboxylic acid dianhydride of the formula (IV) in an organic polar solvent at 20.degree.-250.degree. C., ##STR2## wherein Ar, X, Y, R.sup.

Abstract: A crystalline polyimide polymer having a practical effectiveness that extrusion or injection molding which has so far been applied to thermoplastic resins, but could not have been achieved by conventional polyimides, are possible due to its melting point in the range of 300.degree. C. to 450.degree. C., and a process for producing the polymer, are provided, which polyimide polymer contains the following imide repetition unit (I) in 30% by mol based on the polymer and containing or not containing at least one of other imide repetition units and also having an inherent viscosity of 0.1 to 5 dl/g in conc. sulfuric acid at 30.+-.0.01.degree. C.: ##STR1## wherein X is divalent CO, divalent SO.sub.2 group, S, O or a single bond.

Abstract: A process for producing .alpha.-olefin polymers having high crystallinity and good particle form, with a high yield is provided. The polymerization therefor is carried out in the presence of a preactivated catalyst suitable particularly to gas phase polymerization or gas phase polymerization following slurry or bulk polymerization.The catalyst is prepared by reacting a reduction solid prepared by reducing TiCl.sub.4 with an organoaluminum compound, with an electron donor and an electron acceptor to obtain a solid product, andcombining this solid product with an organoaluminum compound, an .alpha.-olefin and a reaction product of an organoaluminum compound with an electron donor.

Abstract: A preactivated catalyst for producing .alpha.-olefin polymers is provided, which is obtained by the steps which comprises:reacting an organoaluminum compound (O-Al.sub.1) with an electron donor (ED.sub.1) to obtain a reaction product (I);reacting (I) with TiCl.sub.4 to obtain a solid product (II);reacting (II) with an electron donor (ED.sub.2) and an electron acceptor to obtain a solid product (III);combining (III) with an organoaluminum compound (O-Al.sub.2) and a reaction product (RP) of an organoaluminum (O-Al.sub.3) with an electron donor (ED.sub.3) (III), (O-Al.sub.2) and (PP) being referred to as catalyst components), and in this combination, subjecting a part or the whole of the catalyst components to polymerization treatment with an .alpha.-olefin at least in the presence of (III) and said (O-Al.sub.2) to obtain a preliminarily activated catalyst; andpolymerizing an .alpha.-olefin in the presence of the catalyst.

Abstract: A process for producing terpolymers of propylene (as a main monomer), ethylene and another .alpha.-olefin having superior and well-balanced physical properties, almost without forming soluble polymer is provided.This process is characterized by preliminarily activating a catalyst consisting of a titanium trichloride composition and a specified organoaluminum halide, with a small amount of an .alpha.-olefin of 2 to 12 carbon atoms, a trialkylaluminum and an aromatic ester, and copolymerizing specified amounts of propylene, ethylene and an .alpha.-olefin of 4 to 12 carbon atoms in the presence of the preliminarily activated catalyst obtained above.

Abstract: A process for producing .alpha.-olefin polymers with a controlled stereoregularity and with a higher yield is provided, which process comprises: combining a TiCl.sub.3 -containing composition obtained by reducing TiCl.sub.4, with an organoaluminum compound; thereafter subjecting the composition to a polymerization treatment with an .alpha.-olefin; before, during or after the polymerization treatment, adding an electron donor or/and an electron acceptor or a reaction product of these two; as well as adding a reaction product of a trialkylaluminum with an electron donor having a specified molar ratio of the electron donor to the trialkylaluminum selected in the range of 0.01 to 5; and polymerizing an .alpha.-olefin in the presence of the resulting preactivated catalyst.

Abstract: A method for producing .alpha.-olefin polymers is provided. This method provides products having superior properties such as higher bulk density and uniform particle form which is close to sphere, with such an extremely higher catalyst efficiency that ash-removal step can be omitted without fear of coloring.

Abstract: A process for producing .alpha.-olefin polymers characterized by employing an organomagnesium compound in the preparation of a preactivated catalyst therefor is provided. The resulting polymers have particularly a higher rigidity in addition to various superior properties. The process comprises reacting a trivalent metal halide with a divalent metal compound to obtain a solid product (I); reacting this product with an organomagnesium compound, an electron donor (ED) and an electron acceptor (EA), once to 10 times, and at that time, using TiCl.sub.4 at least once as the (EA) to obtain a solid product (II); combining this product with an organoaluminum compound (OAl) and an (ED), and at that time, subjecting a combination of (II) and (OAl) or that of (II), (OAl) and (ED) to polymerization treatment with an .alpha.-olefin, and in the case of the former combination, further adding (ED), to obtain a preactivated catalyst; and polymerizing .alpha.-olefin(s) in the presence of this catalyst.

Abstract: A process for producing .alpha.-olefin polymers is provided, which comprises: reacting an organoaluminum compound with an electron donor in a specified ratio in a solvent at a specified temperature to obtain a solid product (I); reacting solid product (I) with TiCl.sub.4 at a specified temperature in a specified ratio of Al/Ti and then removing a liquid portion from the resulting material followed by washing to obtain a solid product (II) having no free TiCl.sub.4 ; reacting solid product (II) with an electron donor and an electron acceptor in a specified ratio at a specified temperature to obtain a solid product (III); and polymerizing .alpha.-olefin(s) in the presence of a catalyst comprising a combination of solid product (III) with an organoaluminum compound. This process provides a catalyst having a high storing and thermal stability and a polymer having a uniform particle size.

Abstract: A process for producing high-quality .alpha.-olefin polymers with a higher yield in a long lasting stabilized manner even in the case of gas phase polymerization is provided. In the production process of .alpha.-olefin polymers which comprises reacting a trivalent metal halide with a divalent metal compound to obtain a solid product (I); reacting this product with at least one electron donor (ED) and at least one electron acceptor (EA), once to 10 times, and at that time, using TiCl.sub.4 at least once as the (EA) to obtain a solid product (II); combining this product with an organoaluminum compound (OAl) and an (ED) (these three being referred to as catalyst components), the improvement which comprises subjecting a part or the whole of the catalyst components to polymerization treatment with a small amount of an .alpha.-olefin, at least in the coexistence of the solid product (II) and (OAl), in the combination of the catalyst components to obtain a preactivated catalyst, and subjecting .alpha.

Abstract: A method for producing .alpha.-olefin polymers which enables to control molecular weight distribution in a narrower range, with a higher yield and a higher crystallinity of products, is proposed. A catalyst used in said method is also proposed. The solid component of said catalyst is obtained by reacting a trivalent metal halide with a hydroxide, an oxide, a carbonate of a divalent metal, a double compound containing any of these compounds or a hydrate of a compound containing a divalent metal to produce a solid product (I); reacting one or more electron donors and one or more electron acceptors separately or simultaneously each in from one step 10 steps but by using TiCl.sub.4 as an acceptor at least in one step, with said solid product (I) to obtain a solid product (II); and then combining an organoaluminum compound and an electron donor with said solid product (II).

Abstract: A process for producing .alpha.-olefin polymers is provided which comprises:reacting an organoaluminum compound (A.sub.1) with an electron donor (B.sub.1) to obtain a reaction product (I);reacting (I) with TiCl.sub.4 to obtain a solid product (II);reacting (II) with an electron donor (B.sub.2) and an electron acceptor to obtain a solid product (III);combining (III) with an organoaluminum compound (A.sub.2) and a reaction product (G) of an organoaluminum (A.sub.3) with an electron donor (B.sub.3) ((III), (A.sub.2) and (G) being referred to as catalyst components), and in this combination, subjecting a part or the whole of the catalyst components to polymerization treatment with an .alpha.-olefin at least in the presence of (III) and said (A.sub.2) to obtain a preliminarily activated catalyst;andpolymerizing an .alpha.-olefin in the presence of the catalyst.

Abstract: A process for producing .alpha.-olefins is provided which comprises:milling (A) a trivalent metal halide together with (B) a divalent metal compound, in a specified ratio of (A) to (B), and reacting them to obtain a solid product (I);reacting with this product (I), (C) an electron donor and (D) an electron acceptor, (C) and (D) being respectively reacted once or more up to ten times, and TiCl.sub.4 being employed as the electron acceptor at least once, to obtain a solid product (II);combining with this product (II), (E) a trialkylaluminum and (G) a reaction product of an electron donor with an electron acceptor, and in this combination, subjecting a part or the whole of the catalyst components (product (II), (E) and (G)) to polymerization treatment by reacting (F) an .alpha.-olefin at least in the presence of the product (II) and trialkylaluminum, to obtain a preliminarily activated catalyst; andpolymerizing an .alpha.-olefin in the presence of this catalyst.