Chinese Academy of Sciences

Bobst (shanghai) Ltd.

Qiang Fang

Kai Lin Li

Chao Yuan

Yingchun Liu

Mingliang Zhou

Shen Diao

Nicolas Panchaud

Kaikai Jin

Michael Cochard

The invention relates to a device () for holding a sheet-like element () during the stage of introducing it into a workstation () of a forming machine (), such as a waste-ejection station (), the said holding device () comprising a suction member () configured so as to partially retain each sheet () by its rear part during the stage when the said sheet () is introduced into the said workstation (), characterized in that the suction member () has at least two motorized fans () with propellers () installed transversely at the entrance to the workstation (), beneath the plane (P) along which the sheet-like elements move, the axes of rotation (A) of the propellers () of the fans () being substantially parallel to one another and perpendicular to the plane (P) along which the sheet-like elements move, the direction of rotation and the inclination of the propellers () being configured so as to generate a flow of air capable of applying suction to the rear of the lower face of the sheet-like element () during the stage in which the said sheet () is introduced into the said workstation ().

Holding device for a workstation of a forming machine

The present invention belongs to the field of preparation of high performance polymers, and specifically relates to a low dielectric constant polymer containing dinaphthyl and hexafluorocyclobutyl ether units, and preparation method and use thereof. The polymer is prepared as follows: under the effect of an alkali, 1-naphthol bromotetrafluoroethane ether is prepared from 1-naphthol and tetrafluorodibromoethane in an organic solvent, and then reduced by a zinc powder so as to obtain 1-naphthol trifluorovinyl ether. 1-naphthol trifluorovinyl ether is treated at a high temperature to obtain a bisnaphthol hexafluorocyclobutyl ether monomer. The monomer is subjected to oxidative coupling in the presence of ferric trichloride so as to obtain a thermal polymer containing dinaphthyl and hexafluorocyclobutyl structural units with a good film-forming property, and in a nitrogen atmosphere, the temperature for 5% weight loss (T) of the obtained film is 437&#xb0; C., and the carbon residue yield at 1000&#xb0; C. is 54.24%. The dielectric constant (30 MHz) of the film is 2.33. The polymer is suitable for use in the electronic and electrical industries as an insulation coating layer and an encapsulating material for electron components.

Low dielectric constant polymer containing dinaphthyl and hexafluorocyclobutyl ether unit, preparation method and use

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Shanghai, China

Qiang Fang