Compositions: coating or plastic – Materials or ingredients – Pigment – filler – or aggregate compositions – e.g. – stone,...
Reexamination Certificate
2002-06-13
2003-08-05
Green, Anthony J. (Department: 1755)
Compositions: coating or plastic
Materials or ingredients
Pigment, filler, or aggregate compositions, e.g., stone,...
C106S479000, C106S499000, C106S503000
Reexamination Certificate
active
06602339
ABSTRACT:
TECHNICAL FIELD
The present invention relates to aluminum pigments useful in water metallic paints, water metallic inks or the like, method for their preparation and resin compositions containing them.
PRIOR ARTS
The incorporation of aluminum pigments into aqueous varnishes causes various problems such as an explosion of a container during storage due to the reaction with water contained in the varnishes to produce hydrogen gas and an agglomeration of the aluminum pigment to form grainings. Many techniques for resolving the problems have been developed. Among them, JP-B-89/054386 (1989), JP-A-59/074201 (1984), JP-B-85/008057 (1985), JP-A-04/318181 (1992), U.S. Pat. No. 5,296,032, JP-A-06/057171 (1994) and JP-A-09/328629 (1997) are known as recent techniques having high possibility of practical use.
JP-B-89/054386 (1989) discloses a method comprising treating an aluminum pigment with chromic acid. Although chemical stability of the aluminum pigment is improved according to the method, the method has problems such that the aluminum pigment in the finely divided form cannot be treated due to a strong reactivity of the treating liquid used and that the hygiene for operators and environment are damaged by using hexavalent chromium. Thus, the above method is not almost subjected to the practical use.
JP-A-59/074201 (1984) discloses a method comprising treating an aluminum pigment with ammonium vanadate. Color tone of the aluminum pigment is significantly changed by this treatment. Thus, the above method has not been practically applied.
JP-B-85/008057 (1985) discloses a method comprising coating an aluminum pigment with an acid phosphate ester. Although color tone and chemical stability of the aluminum pigment are better, the treating agent adversely affects an adhesion between the aluminum pigment and a resin when a film is formed according to the two-coat/one-bake coating method or the two-coat/two-bake coating method so that a base metallic film and a top coat will be delaminated, which becomes problematic.
JP-A-04/318181 (1992) discloses a method comprising treating an aluminum pigment with a treating liquid containing an oxidizing agent such as molybdic acid, a phosphate ion and an alkaline earth metal ion. Although the resultant aluminum pigment has excellent chemical stability, the phosphate ion and the alkaline earth metal ion contained in the treating liquid tend to lower physical properties including a moisture resistance of a film.
U.S. Pat. No. 5,296,032 discloses a method comprising treating an aluminum pigment with a heteropolyanion such as phosphomolybdic acid and the like. Although the aluminum pigment treated with phosphomolybdic acid is chemically stable, the phosphate ion contained in the treating liquid lowers physical properties including a moisture resistance of a film. Sufficient chemical stability is not obtained when any other treating agent is used.
JP-A-06/057171 (1994) discloses a method for stabilizing an aluminum pigment comprising treating the aluminum pigment with ammonium molybdate and then adding molybdate salt or the like. Although the resultant aluminum pigment has excellent chemical stability and the resultant film has better physical properties, the preparation process is complicated.
JP-A-09/328629 (1997) discloses an aluminum pigment treated with peroxo-polyanion. Since a coating derived from peroxo-polyanion is dense and has excellent corrosion resistance, an aluminum pigment which is chemically very stable to a varnish for water paints and water inks can be obtained by forming the coating on a surface of the aluminum pigment. In addition, since a component adversely affecting physical properties of a film such as a phosphate ion and an alkaline earth metal ion is not contained in the coating, moisture- and weather-resistances of the resultant film are not lowered even by incorporating the aluminum pigment having the above coating. Thus, the aluminum pigment is excellent chemical stability together with better physical properties of a film, but it has problems such that the aluminum pigment tends to be agglomerated during its preparation so that grainings are produced on the resultant film or it adversely affects an appearance of the resultant film. Thus, the above aluminum pigment is not practically applied.
SUMMARY OF THE INVENTION
The present inventors investigated to form a better coating derived from peroxo-polyanion on a surface of an aluminum pigment without agglomelating the aluminum pigment during its preparation. As the result, they found that it is effective to add at least one amine selected from alkylamine, allylamine, arylamine, alkanolamine and alkoxylamine to peroxo-polymolibdate and the chemical stability of the resultant coating and the prevention of an aluminum pigment from agglomerating can be improved by forming an adsorption layer of an organic phosphorus compound onto the coating.
DETAILED EXPLANATION OF THE INVENTION
According to the present invention made based on these findings, the aluminum pigment excellent in water resistance comprises at least one amine selected from alkylamine, allylamine, arylamine, alkanolamine and alkoxylamine and has a coating derived from polymolybdic acid peroxide formed on a surface thereof.
Preferably, 0.025 to 5 parts by weight of molybdenum (Mo) and 0.08 to 20 parts by weight of oxygen (O) are contained per 100 parts by weight of aluminum.
It is preferable to further have an adsorption layer of an organic phosphorus compound which is preferably an acidic phosphate ester derived from an aliphatic monohydric or polyhydric alcohol containing 4 to 18 carbon atoms, on the inorganic coating.
The aluminum pigment of the present invention is prepared by adding to an aluminum pigment composition containing an organic solvent, at least one amine selected from alkylamine, allylamine, arylamine, alkanolamine and alkoxylamine together with a solution of a metallic molybdenum dissolved in an aqueous hydrogen oxide and a hydrophilic solvent and then stirring and mixing to form an inorganic coating on a surface of the aluminum and if necessary, adding an organic phosphorus compound before getting paste.
Further, the resin composition according to the present invention is obtained by adding the aluminum pigment of the present invention.
Several essential features of the present invention and the reason for the numerical limitation of each essential feature are fully described below.
(1) Peroxo-polymolybdate
The peroxo-polymolybdate used in the present invention is represented by the compositional formula:
MoO
3
.m
H
2
O
2
.n
H
2
O or MoO
3-m
(O
2
)
m
.n
H
2
O
wherein Mo is a molybdenum, O is oxygen, 0≦m≦1 and 1≦is≦2. A solution comprising polymolybdic acid peroxide having the above composition is prepared by the method comprising dissolving a metallic molybdenum in hydrogen oxide as described in, for example, Solid States Ionics, pp. 507-512, 1992. Owing to peroxo-polymolybdate having the above composition, a coating excellent in chemical stability can be formed on a surface of the aluminum pigment. And, such a pigment does not lower physical properties of the resultant film even if incorporated into a resin composition.
(2) Mo (Molybdenum) Content
The Mo content in the coating formed on the surface of the aluminum pigment is 0.02 to 5 parts by weight per 100 parts by weight of aluminum. If it is less than 0.02 part by weight, the desired chemical stability is hardly obtained. On the other hand, if it is above 5 parts by weight, the aluminum pigment agglomerates so that its design and its hiding property are impaired. Although JP-A-09/328629 (1997) describes that an amount of a metallic element is most suitably in the range from 0.01 to 2 parts by weight per 100 parts by weight of aluminum, the agglomeration of the aluminum pigment does not occur even if the amount of peroxo-polymolibdate is further increased, thereby a thicker coating with an improved chemical stability can be formed according to the present invention.
Preferably, the Mo content will be varied depending on a water coveri
Hashizume Yoshiki
Nakao Takayuki
Green Anthony J.
Nixon & Vanderhye P.C.
Toyo Aluminium Kabushiki Kaisha
LandOfFree
Aluminum pigment, process for its production and resin... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Aluminum pigment, process for its production and resin..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Aluminum pigment, process for its production and resin... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3075841