Compositions – Reductive bleachant – deoxidant – reductant – or generative – Deoxidant or oxygen scavenging
Reexamination Certificate
1999-06-14
2001-06-19
Anthony, Joseph D. (Department: 1714)
Compositions
Reductive bleachant, deoxidant, reductant, or generative
Deoxidant or oxygen scavenging
C252S400510, C252S400520
Reexamination Certificate
active
06248258
ABSTRACT:
BACKGROUND OF THE INVENTION
1) Field on the Invention
The present invention relates to an oxygen absorbent with functions absorbing oxygen, inorganic gases, organic gases and moisture, which is applicable to preservation of metal parts, electronic parts, electrical parts, precise parts, magnetic or optical parts, jewelry, weapons, airplanes, automobiles, glasses, rubber products, photographic films, foodstuffs, medicines, pressed flowers, paintings ancient documents and unearthed articles.
2) Prior Art
Oxygen absorbents containing metal powders, catechol, ascorbic acid, etc., as main ingredients are known. However, it has been required that such oxygen absorbents is used under a high humidity in the interior of the system since they need moisture to absorb oxygen, so that articles to be preserved have been limited. Therefore, an oxygen absorbent requiring no moisture in absorption of oxygen has been desired. Japanese Patent Publication No. 62-60936 discloses an oxygen absorbent containing an unsaturated fatty acid(s) or a fat and oil containing an unsaturated fatty acid(s) as main ingredient to be oxidized and a transition metal(s) as catalyst. Japanese Patent Kokai (Laid open) No. 4-29741 discloses an oxygen absorbent containing an aliphatic hydrocarbon(s) with an unsaturated group(s) and/or an unsaturated fatty acid compound(s) as main ingredient to be oxidized and a transition metal(s) as catalyst.
On the other hand, there has been desired an oxygen absorbent with a high performance in which an oxygen absorbing time to be required for decreasing an oxygen concentration in the interior of the system to an oxygen concentration of 0.1% or below to be able to neglect substantially oxygen is efficiently shortened. Thus, since an amount of an oxygen absorbent to be used is reduced and a size of an oxygen absorbent can be made small by improving an oxygen absorbing velocity, also from the viewpoint that recent resource saving and energy saving can be attained,it has been desired to attain such art for improvement of an oxygen absorbing velocity.
In above-mentioned prior art oxygen absorbent, an oxygen absorbing time is sharply prolonged since an oxygen absorbing velocity becomes low after absorbing a small amount of oxygen. Further, it is difficult to attempt not to contact perfectly the oxygen absorbent with oxygen during production of the oxygen absorbent. Also when the oxygen absorbent is actually applied or also when necessary amount of the oxygen absorbent is taken out from a sealed bag enclosed a specific amount of the oxygen absorbent and then remained amount of the oxygen absorbent is preserved, it is difficult to attempt to not to contact perfectly it with oxygen. Therefore, in order not to contact the oxygen absorbent with oxygen, it is necessary to handle it under an atmosphere of an inert gas such as nitrogen which results in inconvenience of its handling.
SUMMARY OF THE INVENTION
It is an object of the present invention to improve an oxygen absorbing velocity of an oxygen absorbent containing an aliphatic hydrocarbon(s) with an unsaturated group(s) and/or an unsaturated fatty acid compound(s) as main ingredient to be oxidized.
Further, it is an object of the present invention also to provide an oxygen absorbent convenient in handling in which an oxygen absorbing velocity is not so lowered even after absorbing a small amount of oxygen during its production or its application.
As a result of extensive studies to attain above-mentioned objects, the inventors have found that addition of non-transition metal salts(s) alone to an aliphatic hydrocarbon(s) with an unsaturated group(s) and/or an unsaturated fatty acid compound(s) as the main ingredient to be oxidized promotes no oxygen absorption, but addition of a mixture of a transition metal salt(s) with a non-transition metal salt(s) to above-mentioned main ingredient remarkedly promotes an oxygen absorbing velocity, and has accomplished the present invention
Further, surprisingly, it has become possible to depress lowering of the oxygen absorbing velocity after absorbing a small amount of oxygen by mixing above-mentioned main ingredient with both the transition metal salt(s) and the non-transition metal salt(s).
That is, the present invention provides an oxygen absorbent comprising: an aliphatic hydrocarbon(s) with an unsaturated group(s) and/or an unsaturated fatty acid compound(s) and a catalyst containing both a transition metal salt(s) and a non-transition metal salt(s).
Further, in the present invention, it is preferable that the transition metal salt(s) is (are) at least one salt of metal selected from the group consisting of Cu, Fe, Co, Ni, Cr, and Mn and the non-transition metal salt(s) is (are) at least one salt of metal selected from the group consisting of Ca, Pb and Zn.
It is preferable also that a weight ratio of metal in a transition metal salt(s) to metal of a non-transition metal salt(s) is 1/0.01 to 1/40.
It is preferable that the aliphatic hydrocarbon(s) with an unsaturated group(s) and/or an unsaturated fatty acid compound(s) is a liquid hydrocarbon oligomer and particularly, a liquid butadiene oligomer.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail below.
Examples of the aliphatic hydrocarbon with an unsaturated group(s) as the main ingredient to be oxidized include liquid low or middle molecular polymers including liquid butadiene oligomers, liquid isoprene oligomers, squalene, liquid acetylene oligomers, liquid pentadiene oligomers, liquid oligoesteracrylate, liquid butene oligomers, liquid BR, liquid SBR, liquid NBR, liquid chloroprene oligomers, liquid sulfide oligomers, liquid isobutylene oligomers, liquid butyl rubber, liquid cyclopentadine type petroleum resins, liquid oligostyrene, liquid hydroxypolyolefin oligomers, liquid alkyd resins, liquid unsaturated polyester resins, and natural rubbers.
Examples of the unsaturated fatty acid compound include unsaturated fatty acids such as linoleic acid, linolenic acid, arachidonic acid, parinaric acid and dimer acid, and fats and oils containing esters of said unsaturated fatty acids and metal salts of acid unsaturated fatty acids.
As the unsaturated fatty acid, fatty acids obtained from vegetable oils or animal oils, i.e., linseed oil fatty acid, soybean oil fatty acid, tung oil fatty acid, rice bran oil fatty acid, sesame oil fatty acid, cotton seed oil fatty acid, rapeseed oil fatty acid, tall oil fatty acid, and the like are used.
Among the above-mentioned aliphatic hydrocarbons with an unsaturated group(s) and unsaturated fatty acid compounds, liquid butadiene oligomers are preferable since an amount of gases generating after absorbing oxygen is small and they emit few odor.
The aliphatic hydrocarbon with an unsaturated group(s) and/or the unsaturated fatty acid is not necessarily one kind of substance and may be a mixture of two species or above thereof, or a copolymer thereof. A small amount of impurities such as solvents mixed during production thereof may be allowed in an ordinary range.
The aliphatic hydrocarbon with an unsaturated group(s) and/or the unsaturated fatty acid compound(s) may have a substituted group(s) other than unsaturated group. For example, they may be substituted with a functional group(s)including alicyclic hydrocarbon group, aromatic hydrocarbon group, halogen group, hydroxyl group, hydroperoxy group, epoxy group, oxo group, carbonyl group, hydroxymethyl group, ether group, carboxyl group, ester group, acyl group, amino group, imino group, nitrile group, nitro group, nitroso group, amido group, imido group, cyano group, isocyano group, cyanate group, isocyanate, diazo group, azido group, hydrazino group, azo group, thio group, thioxo group, mercapto group, thiocarbonyl group, sulfonyl group, sulfinyl group, sulfone group, thiocyanate group, isothiocyanate group and heterocyclic group.
As the transition metal salt(s) to be used in the catalyst of the present invention, at least one salt of metal selected the group consisting of Cu, Fe, Co, Ni, Cr and Mn is (are) preferable. The t
Baba Junko
Himeshima Tomoharu
Iwai Tatsuo
Tomita Kazuyuki
Watanabe Takayuki
Anthony Joseph D.
Armstrong Westerman Hattori McLeland & Naughton LLP
Mitsubishi Gas Chemical Company Inc.
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