1,1,1,2-テトラフルオロエタン 化学特性,用途語,生産方法
用途
冷媒、溶媒、医薬品の噴射剤、発泡剤。
効能
吸入麻酔薬
化学的特性
colourless gas or cryogenic liquid with an ether-like odour
使用
Refrigerant, propellant for pharmaceuticals; blowing agent for foams.
調製方法
Tetrafluoroethane can be prepared by several different routes;
however, the following routes of preparation illustrate the methods
used:
Isomerization/hydrofluorination of 1,1,2-trichloro-1,2,2-trifluoroethane
(CFC-113) to 1,1-dichloro-1,2,2,2-tetrafluoroethane
(CFC-114a), followed by hydrodechlorination of the latter.
Hydrofluorination of trichloroethylene, via 1-chloro-1,1,1-
trifluoroethane (HCFC-133a).
一般的な説明
A colorless gas with a slight ethereal odor. Vapors are heavier than air. Shipped liquefied under own vapor pressure. Flash point 351°F. Inhalation at high concentrations is harmful and may cause heart irregularities, unconsciousness or death without warning. Liquid contact may cause frostbite. Vapors can replace the available oxygen.
空気と水の反応
Insoluble in water.
反応プロフィール
1,1,1,2-Tetrafluoroethane is chemically inert in many situations, but can react violently with strong reducing agents such as the very active metals and the active metals. Can react with strong oxidizing agents or weaker oxidizing agents under extremes of temperature.
健康ハザード
Vapors may cause dizziness or asphyxiation without warning. Vapors from liquefied gas are initially heavier than air and spread along ground. Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. Fire may produce irritating, corrosive and/or toxic gases.
火災危険
Some may burn but none ignite readily. Containers may explode when heated. Ruptured cylinders may rocket.
応用例（製薬）
Tetrafluoroethane is a hydrofluorocarbon (HFC) or hydrofluoroalkane
(HFA) aerosol propellant (contains hydrogen, fluorine, and
carbon) as contrasted to a CFC (chlorine, fluorine, and carbon). The
lack of chlorine in the molecule and the presence of hydrogen reduce
the ozone depletion activity to practically zero. Hence tetrafluoroethane
is an alternative to CFCs in the formulation of metereddose
inhalers (MDIs). It has replaced CFC-12 as a refrigerant
and propellant since it has essentially the same vapor pressure. Its
very low Kauri-butanol value and solubility parameter indicate that
it is not a good solvent for the commonly used surfactants for MDIs.
Sorbitan trioleate, sorbitan sesquioleate, oleic acid, and soya
lecithin show limited solubility in tetrafluoroethane and the amount
of surfactant that actually dissolves may not be sufficient to keep a
drug readily dispersed. Up to 10% ethanol may be used to increase
its solubility.
When tetrafluoroethane (P-134a) is used for pharmaceutical
aerosols and MDIs, the pharmaceutical grade must be specified.
Industrial grades may not be satisfactory due to their impurity
profiles.
安全性
Tetrafluoroethane is used as a refrigerant and as a non-CFC
propellant in various aerosols including topical pharmaceuticals
and MDIs. Tetrafluoroethane is regarded as nontoxic and
nonirritating when used as directed. No acute or chronic hazard
is present when exposures to the vapor are below the acceptable
exposure limit (AEL) of 1000 ppm, 8-hour and 12-hour time
weighed average (TWA). In this regard it has the same value as
the threshold limit value (TLV) for CFC-12. Inhaling a high
concentration of tetrafluoroethane vapors can be harmful and is
similar to inhaling vapors of CFC-12. Intentional inhalation of
vapors of tetrafluoroethane can be dangerous and may cause death.
The same labeling required on CFC aerosols would be required for
those containing tetrafluoroethane as a propellant (except for the
EPA requirement).
発がん性
The results from three lifetime
inhalation carcinogenesis studies with HFC 134a have been
published. The first one involved exposure of groups of
80 male and 80 female rats to levels of ≤50,000 ppm 6 h/
day, 5 days/week for 2 years.An increase inLeydig cell tumors
was seen in themale rats at 50,000 ppm(30%) compared to the
air-exposed controls (12%). Likewise, therewas an increase in
Leydig cell hyperplasia. No effects were seen at 10,000 ppm
(370). The second study with rats involved snout-only inhalation
exposures to levels of ≤50,000 ppm 1 h/day, 7 days/week
for 108 weeks. The same investigators conducted a lifetime
study withmice. In this study, groups of mice were exposed to
snout-only levels of ≤75,000 ppm 1 h/day, 7 days/week for
104 weeks. No adverse effects were seen in either rats or
mice. Since the total dose received by the rats in the high
exposure level of this study was lower than in the Collins’
study, this report supports the observation that 10,000 ppm,
6 h/day, 5 days/week for 2 years was a NOEL.
Rats were given 300 mg of HFC 134a in corn oil 5 days/
week for 52 weeks and held for a total of 125 weeks.
There was no evidence for carcinogenicity.
貯蔵
Tetrafluoroethane is a nonreactive and stable material. The liquified
gas is stable when used as a propellant and should be stored in a
metal cylinder in a cool dry place.
不和合性
The major incompatibility of tetrafluoroethane is its lack of
miscibility with water. Since it has a very low Kauri-butanol value,
tetrafluoroethane is considered to be a very poor solvent for most
drugs used in MDI formulations. It also shows a low solubility for
some of the commonly used MDI surfactants.
規制状況(Regulatory Status)
Included in the FDA Inactive Ingredients Database (aerosol
formulations for inhalation and nasal applications). Included in
nonparenteral medicines licensed in the UK.
1,1,1,2-テトラフルオロエタン 上流と下流の製品情報
原材料
2,2-ジフルオロ-1-クロロエテン
ビニリデンジフルオリド
1-クロロ-1,2,2,2-テトラフルオロエタン
1,1,2-トリフルオロエテン
1,1,1-トリフルオロ-2-クロロエタン
Benzene, (2-chloro-1,1-difluoroethoxy)-
Benzene, 1-(2-chloro-1,1-difluoroethoxy)-2-methyl-
Benzene, 1-(2-chloro-1,1-difluoroethoxy)-4-methyl-
2,2,2-trifluoroethyl ethyl ether
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