Abstract: A polyarylate resin includes repeating units represented by formulas (1), (2), (3), and (4). A percentage of the number of repeats of the repeating unit represented by formula (3) relative to the total number of repeats of the respective repeating units represented by formulas (1) and (3) is greater than 0% and less than 20%. In formula (1), R1 and R2 each represent, independently of one another, a hydrogen atom or a methyl group and X represents a divalent group represented by formula (X1) or (X2). In formula (2), W represents, a divalent group represented by formula (W1) or (W2).

Abstract: A polyarylate resin includes repeating units represented by formulas (1), (2), and (4). The polyarylate resin further includes a repeating unit represented by formula (3) and a percentage of the number of repeats of the repeating unit represented by formula (3) relative to the total number of repeats of the respective repeating units represented by formulas (1) and (3) is greater than 0% and less than 50%. Or, the polyarylate resin does not include the repeating unit represented by formula (3). In formula (1), R1 and R2 each represent, independently of one another, a hydrogen atom or a methyl group and X represents a divalent group represented by formula (X1) or (X2). In formula (3), R5 and R6 each represent, independently of one another, a hydrogen atom or a methyl group.

Abstract: A backup power source device includes the following elements: a capacitor; a charging circuit provided in the charging path of the capacitor and performing step-down operation; a boost circuit provided in the output path of the capacitor; and a door-lock-releasing output terminal connected to the boost circuit.

Abstract: A backup power source device includes the following elements: a capacitor; a charging circuit provided in the charging path of the capacitor and performing step-down operation; a boost circuit provided in the output path of the capacitor; and a door-lock-releasing output terminal connected to the boost circuit.

Abstract: Disclosed is a both-side roughened copper foil with a protection film, comprising a metal foil as soft as or softer than copper, or an organic type film having a melting point equal to or higher than a lamination temperature, laminated on one side of a copper foil with both sides roughened, the metal foil or organic film being continuously or continually bonded or adhered to the copper foil. It is possible to protect the ruggedness on the roughened surface at the time the both-side roughened copper foil is cut, packed, transported or stacked on another both-side roughened copper foil, simplify the press molding work, and improve the production efficiency particularly in the step of fabricating a copper-clad laminated board for a printed circuit board as well as the quality of the acquired copper-clad laminated board.

Abstract: A copper foil for an inner layer circuit of a multi-layered printed circuit board, which comprises a black metal plated layer formed on at least the rough surface which becomes a surface of an inner layer circuit of a copper foil having both sides roughened in advance, in order to enhance the bonding strength to a prepreg, make it safe from haloing and facilitate optical checking of the copper foil.

Abstract: A method for preparing a copper-clad laminated board for a printed circuit board which comprises: (a) preparing a prepreg by permeating a thermosetting resin into a fabric and then drying the resulting material to a half-hardened state, (b) laminating a both-side roughened copper foil on both sides or one side of the prepreg or a plurality of prepregs bonded together, (c) placing the resulting laminate from step (b) between both press plates of a press machine, (d) placing a polyamide film having a melting point equal to or higher than 170.degree. C. between the exposed side of the both-side roughened copper foil of the laminate and a press plate, (e) pressing the laminate with the press plates of the press machine at a temperature of 170.degree. C. or higher, a pressure of 10 kgf/cm.sup.2 or higher for a time of 60 minutes or longer, (f) separating the laminate from the press machine and (g) peeling the polyamide film from the laminate to obtain the copper-clad laminated board.

Abstract: A high-ortho phenolic novolac resin having excellent curability, heat stability and flowability can be produced safely at low cost by a process which comprises reacting a phenol and an aldehyde at a temperature of more than 100.degree. C. with (A) a catalyst effective for the addition reaction selected from the salts of divalent metals in combination with (B) a catalyst effective for the condensation reaction, or comprises reacting a phenol and an aldehyde under reflux in the presence of the catalyst (A), adding an acid to adjust the pH to 1-5, removing water under reduced pressure and then subjecting the product to reaction at a temperature of more than 100.degree. C. This process enables the addition reaction and the condensation reaction to proceed with a good balance, can solve problems arising in the prior process such as gelation, low yield and the like, and can produce a high-ortho type phenolic novolac resin safely at low cost. Accordingly, this process is quite advantageous in industry.