Abstract:
There is provided a modified ion exchange resin catalyst which exhibits higher bisphenols selectivity than the conventional modified ion exchange resins in processes wherein bisphenols are produced by reacting a phenolic compound with ketones, and to provide such a process for producing bisphenols. A modified ion exchange resin is characterized in that at least one compound selected from (A) and (B) shown below is ionically bonded to an acidic functional group of an acidic ion exchange resin: (A) Compound represented by Formula (1) and (B) Compound represented by Formula (2)
Abstract:
The present invention provides a process for producing bisphenol A by reacting phenol with actone, wherein reaction is performed at higher temperatures while maintaining high selectivity, and thus high productivity is obtained. The invention relates to a cation-exchange resin, wherein a cation-exchange group is introduced into a syndiotactic polystyrene polymer and the amount of acid is 0.8 milliequivalent/g or more, to a catalyst comprising the cation-exchange resin, and to a process for producing bisphenol A using a cation-exchange resin catalyst.
Abstract:
The present invention provides a process for producing bisphenol A by reacting phenol with acetone, wherein reaction is performed at higher temperatures while maintaining high selectivity, and thus high productivity is obtained. The invention relates to a cation-exchange resin, wherein a cation-exchange group is introduced into a syndiotactic polystyrene polymer and the amount of acid is 0.8 milliequivalent/g or more, to a catalyst comprising the cation-exchange resin, and to a process for producing bisphenol A using the cation-exchange resin catalyst.
Abstract:
A control circuit is used during slow or stop-motion playback operation of a video tape device to drive video tape intermittently. In order to avoid errors in the stopping position of the tape, a pulse width modulated (PWM) signal is provided to a motor controller circuit associated with the capstan motor of the video tape device. A frequency signal generator coupled to this motor generates a frequency signal that varies with the capstan motor speed, and this frequency signal is provided to a retrigger monostable multivibrator which generates a PWM signal whose duty ratio changes in proportion to the capstan motor speed. A drive pulse generator and a brake pulse generator provide drive start and brake start signals, respectively, when it is desired to commence and stop movement of the tape. A drive circuit, including the retrigger monostable multivibrator, receives the drive start signal, the brake start signal, and the frequency signal to generate the PWM signal which is supplied to the motor controller circuit. The frequency signal is selected to have a pulse rate several tens of times the ripple frequency of the motor's torque ripple characteristic so that inaccuracies in stopping position of the motor are eliminated.
Abstract:
There is provided a modified ion exchange resin catalyst which exhibits higher bisphenols selectivity than the conventional modified ion exchange resins in processes wherein bisphenols are produced by reacting a phenolic compound with ketones, and to provide such a process for producing bisphenols. A modified ion exchange resin is characterized in that at least one compound selected from (A) and (B) shown below is ionically bonded to an acidic functional group of an acidic ion exchange resin: (A) Compound represented by Formula (1) and (B) Compound represented by Formula (2)
Abstract:
There is provided a modified ion exchange resin catalyst which exhibits higher bisphenols selectivity than the conventional modified ion exchange resins in processes wherein bisphenols are produced by reacting a phenolic compound with ketones, and to provide such a process for producing bisphenols. A modified ion exchange resin is characterized in that at least one compound selected from (A) and (B) shown below is ionically bonded to an acidic functional group of an acidic ion exchange resin: (A) Compound represented by Formula (1) and (B) Compound represented by Formula (2)
Abstract:
The present invention provides an ion-exchange resin catalyst, as a catalyst for preparing bisphenol from phenol compounds and ketone, which has a higher selectivity to bisphenol and a longer life time, as compared to a conventional ion-exchange resin, and a method for preparing the same.The present invention also provides a method for preparing bisphenol comprising reacting phenol compounds with ketone, wherein the modified acidic ion-exchange resin in which at least one kind of cationic compound selected from the following (a), (b), (c) and (d) ionically binds to an acidic functional group, is used as a catalyst: (a) a quaternary phosphonium ion, (b) a quaternary ammonium ion, (c) a bis(phosphoranylidene) ammonium ion, and (d) an N-substituted nitrogen-containing aromatic cation.
Abstract:
The present invention provides a process for producing bisphenol A by reacting phenol with actone, wherein reaction is performed at higher temperatures while maintaining high selectivity, and thus high productivity is obtained. The invention relates to a cation-exchange resin, wherein a cation-exchange group is introduced into a syndiotactic polystyrene polymer and the amount of acid is 0.8 milliequivalent/g or more, to a catalyst comprising the cation-exchange resin, and to a process for producing bisphenol A using a cation-exchange resin catalyst.
Abstract:
The present invention provides an ion-exchange resin catalyst, as a catalyst for preparing bisphenol from phenol compounds and ketone, which has a higher selectivity to bisphenol and a longer life time, as compared to a conventional ion-exchange resin, and a method for preparing the same.The present invention also provides a method for preparing bisphenol comprising reacting phenol compounds with ketone, wherein the modified acidic ion-exchange resin in which at least one kind of cationic compound selected from the following (a), (b), (c) and (d) ionically binds to an acidic functional group, is used as a catalyst: (a) a quaternary phosphonium ion, (b) a quaternary ammonium ion, (c) a bis(phosphoranylidene) ammonium ion, and (d) an N-substituted nitrogen-containing aromatic cation.
Abstract:
The present invention provides a process for preparing bisphenol A with a high conversion and selectivity by reacting phenol with acetone in the presence of both a polyorganosiloxane having a mercapto group-containing hydrocarbon group and an acid. It is preferable that the polyorganosiloxane having a mercapto group-containing hydrocarbon group and the acid is a polyorganosiloxane having both a mercapto group-containing hydrocarbon group and a sulfonic acid group.