Daikin Industries, Ltd.

Hideyuki Kiyotani

Yoshiyuki Shibuya

Kunihiko Inui

Osamu Tanaka

Shinichi Chaen

Makoto Kobayashi

Seigo Yamamoto

Hitoshi Niinuma

Li Bao

Taku Yamanaka

Shunji Kasai

Osamu Inoue

Seiichi Hirano

Hideki Aomi

Satoshi Hara

Tatsumi Sakano

Emi Kiritani

A tetrafluoroethylene polymer is provided in an air filter medium having a pressure loss that can be reduced and made uniform at a plurality of positions. The tetrafluoroethylene polymer may also be provided in an air filter medium, a filter pack, or an air filter unit. The tetrafluoroethylene polymer has drawability and non-melt processability. The tetrafluoroethylene polymer has a ratio S/Sof 0.60 or more, where Srepresents an endotherm mJ/mg in a range of T° C. or higher and 350° C. or lower, T° C. is a temperature 2.5° C. lower than a temperature T° C. (340≤T≤345) at which a minimum point is given on a heat-of-fusion curve obtained by measuring an unbaked polymer for measurement having no history of heating to a temperature of 300° C. or higher using a differential scanning calorimeter at a temperature-increasing rate of 2° C./min, and Srepresents an endotherm mJ/mg in a range of 320° C. or higher and T° C. or lower.

Tetrafluoroethylene polymer, air filter medium, filter pack, and air filter unit

A filter medium for an air filter includes a pre-collection member, a first porous film, and a second porous film arranged in order from the side that is upstream of the air current. Each of the first porous film and the second porous film has a pressure loss of 30 Pa or more and 90 Pa or less when air is passed through each porous film at a flow rate of 5.3 cm/s, and has a collection efficiency of 95% or more and 99.9% or less for NaCl particles having a particle diameter of 0.3 &#x3bc;m when air containing the NaCl particles is passed through each of the porous films at a flow rate of 5.3 cm/s. The pre-collection member has a pressure loss of 5 Pa or more and less than 55 Pa when air is passed through the pre-collection member at a flow rate of 5.3 cm/s, has a collection efficiency of 15% or more and less than 85% for NaCl particles having a particle diameter of 0.3 &#x3bc;m when air containing the NaCl particles is passed through the pre-collection member at a flow rate of 5.3 cm/s, and has a thickness of more than 0.4 mm.

Filter medium for air filter, filter pack, air filter unit and method for producing the filter medium for air filter

A filtering medium includes first and second porous membranes mainly composed of fluororesin, and a plurality of air permeable supports to support the first and second membranes. The second membrane is disposed downstream of the first membrane. When air containing polyalphaolefin particles with a count median diameter of 0.25 &#x3bc;m is continuously passed through at a flow rate of 5.3 cm/sec and pressure loss is increased by 250 Pa, the first membrane has a dust retention amount larger than the second membrane. The filtering medium has a pressure loss of less than 200 Pa when air is passed through at a flow rate of 5.3 cm/sec. A collecting efficiency of NaCl particles with a particle diameter of 0.3 &#x3bc;m is 99.97% or more when air containing the NaCl particles is passed through at a flow rate of 5.3 cm/sec. The dust retention amount is 25 g/mor more.

Filtering medium for air filter, filter pack, air filter unit, and method for producing filtering medium for air filter

A mixed powder and a material for molding have polytetrafluoroethylene as a main component. Each includes polytetrafluoroethylene that can be fibrillated, a non-hot melt processable component that is not fibrillated, and a hot melt processable component with a melting point of lower than 320&#xb0; C. that is not fibrillated. The non-hot melt processable component that is not fibrillated is contained in a range of 20 to 40% by weight of the total weight. The hot melt processable component is contained at equal to or more than 0.1% by weight but less than 20% by weight of the total weight. A drawn porous body includes a plurality of fibrils, and a plurality of knotted portions that are connected to each other by the fibrils.

Mixed powder and material for molding having PTFE as main component, and drawn porous body

A composition, a mixed powder and a material for molding have polytetrafluoroethylene as a main component. Each includes polytetrafluoroethylene that can be fibrillated, a non-hot melt processable component that is not fibrillated, and a hot melt processable component with a melting point of lower than 320&#xb0; C. that is not fibrillated. The hot melt processable component is contained at equal to or more than 0.1% by weight but less than 20% by weight of a total weight. A filtering medium for an air filter includes a porous membrane made of these components, and an air permeable support. The porous membrane is manufactured, by mixing these components, extruding the mixture, rolling and drawing.

Composition having PTFE as main component, mixed powder, material for molding, filtering medium for filter, air filter unit, and a method for manufacturing a porous membrane

A method of manufacturing a filter medium that has a PF value that exceeds 32, the PF value calculated from the pressure loss and the collection efficiency of the filter medium according to the following formula:PF=[&#x2212;log(permeability (%)/100)/(pressure loss (Pa)]&#xd7;1000[Formula 1]in which permeability (%)=100&#x2212;collection efficiency (%). In this method, 380 ml or more of a liquid lubricant at 20&#xb0; C. is added per 1 kg of a PTFE fine powder, this compound is processed into a tape shape and elongated to obtain a PTFE porous film, and an air permeable support member is heat laminated to at least one surface of the PTFE porous film.

Method for preparing filtering material

The present invention provides a culture container and a cap for a container having a ventilation filter medium or a medium similar thereto that can exchange carbon dioxide gas in the culture container with atmospheric air, and prevent the contamination of sterilized culture medium inside the culture container with fungi, mites, and the like. A culture bottle includes a bottle unit, and a cap that is mounted on an opening. The cap includes a cap unit, and a ventilation filter medium. A hole is provided in the cap unit. The ventilation filter medium includes a plurality of micropores having a pore diameter between 0.1 and 50 micrometers, and is mounted on the hole.

Ventilation filter medium for container, and container and container cap equipped with ventilation filter medium

An air filter medium is provided with a porous film made from a polytetafluoroethylene, and a non-woven fabric laminated on at least one side of the porous film. The non-woven fabric has an apparent density satisfying the following equation: apparent density (g/cm )<1.5&times;(basis weight (g/m )/1000)&plus;0.11. The filter medium is produced by a process that includes a first step of producing a porous film formed from a polytetrafluoroethylene, and a second step of laminating a non-woven fabric on at least one side of the porous film on heating roll that has undergone a non-adhesive treatment. The filter medium is used to manufacture an air filter pack, while the air filter pack is used to manufacture an air filter unit.

Growing community of inventors

Settsu, Japan

Hideyuki Kiyotani