Stock material or miscellaneous articles – Composite – Of addition polymer from unsaturated monomers
Reexamination Certificate
2002-02-04
2003-12-02
Nakarani, D. S. (Department: 1773)
Stock material or miscellaneous articles
Composite
Of addition polymer from unsaturated monomers
C428S035400, C428S036600, C428S036700, C428S451000, C428S520000, C524S104000, C524S186000, C524S233000, C524S261000, C524S394000, C524S399000, C524S404000
Reexamination Certificate
active
06656602
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a gas barrier coating composition used for package applications and the like in pharmaceutical, food, cosmetic, cigarette and toiletry fields and the like, and effective for preventing the permeation of oxygen, water vapor and other gases deteriorating the contents, and a gas barrier coating film excellent in gas barrier properties using the same.
BACKGROUND ART
In recent years, as package materials used for package applications and the like in pharmaceutical, food, cosmetic, cigarette and toiletry fields and the like, materials with gas barrier properties through which oxygen, water vapor and other gases deteriorating the contents do not permeate have been used, for example, for food use, in order to prevent deterioration of the contents such as oxidation of proteins or fats and oils to keep qualities of such as taste.
Complying with such conventional problems, for example, Japanese Patent Laid-open Publication (Hei) 7-266485 proposes a gas barrier material obtained by a procedure that a coating agent containing as a main agent a mixed solution of at least one metal alkoxide or hydrolysate thereof and an isocyanate compound having at least two or more isocyanate groups in its molecule is applied onto a substrate composed of a polymer resin composition, and dried by heating to form a gas barrier coating layer. However, this gas barrier material contains the isocyanate compound having isocyanate groups, melamine, formaldehyde, tin chloride and the like, which might be indirectly orally introduced into the human body, particularly in medical and food applications. Accordingly, the gas barrier material has the problem that it is harmful to the human body.
On the other hand, Japanese Patent No. 1,476,209 proposes a coat material free from an isocyanate and the like and composed of polyvinyl alcohol low in harmfulness. However, the use for retort package for food requires oxygen barrier properties under high humidity, because retorting is carried out under high-temperature, high-humidity conditions of 120° C. or more. The coat material composed of polyvinyl alcohol has the problem that gas barrier properties thereof are significantly influenced by humidity, and the gas barrier properties thereof largely decrease under high humidity.
The present invention has been made against the background of the above-mentioned conventional technical problems, and it is an object of the invention to provide a gas barrier coating composition which undergoes no decrease in barrier properties to gases such as oxygen and water vapor even under high-humidity conditions, which composition does not contain compounds thought to be harmful to the human body, such as an isocyanate group-containing isocyanate compound, melamine, formaldehyde and tin chloride, and which composition is harmless to the human body; and a gas barrier coating film using the same, which film is excellent in gas barrier properties.
DISCLOSURE OF THE INVENTION
The present invention relates to a gas barrier coating composition comprising (a) polyvinyl alcohol resin (hereinafter also referred to as “component (a)”) and (b) at least one member selected from the group consisting of a metal alcoholate represented by general formula (1), a hydrolysate of the metal alcoholate, a condensate of the metal alcoholate, a chelate compound of the metal alcoholate, a hydrolysate of the chelate compound and a metal acylate (hereinafter also referred to as “component (b)”):
R
1
m
M(OR
2
)
n
(1)
wherein M represents a metal atom, R
1
, which may be either identical to or different from each other, represents an organic group having 1 to 8 carbon atoms, R
2
, which may be either identical to or different from each other, represents an alkyl group having 1 to 5 carbon atoms, an acyl group having 1 to 6 carbon atom or a phenyl group, and m and n are each integers of 0 or more and m+n is a valence of M.
Here, the above-mentioned polyvinyl alcohol resin (a) includes at least one member selected from the group consisting of polyvinyl alcohol and an ethylene-vinyl alcohol copolymer.
Further, the above-mentioned polyvinyl alcohol resin (a) includes an ethylene-vinyl alcohol copolymer having a melt flow index of 1 to 50 g/10 minutes under the conditions of 210° C. and a load of 21.168 N.
It is preferred in some cases that the gas barrier coating composition of the present invention further contains (c) a nitrogen-containing organic solvent (hereinafter also referred to as “component (c)).
Further, it is preferred in some cases that the gas barrier coating composition of the present invention further contains (d) fine inorganic particles (hereinafter also referred to as “component (d)).
Still further, it is preferred in some cases that the gas barrier coating composition of the present invention further contains (e) a boron compound (hereinafter also referred to as “component (e)).
Yet still further, it is preferred that the gas barrier coating composition of the present invention has a heating gelation rate of 1 to 90%.
Then, the present invention relates to a method for producing the above-mentioned gas barrier coating composition comprising hydrolyzing the above-mentioned component (b) in water or a mixed solvent of water and a hydrophilic organic solvent, followed by mixing with the above-mentioned component (a).
Further, the present invention relates to a gas barrier coating film in which a coating film formed of the above-mentioned gas barrier coating composition is laminated onto a synthetic resin film.
Furthermore, the present invention relates to a gas barrier coating film in which a vapor-deposited film of a metal and/or an inorganic compound and a coating film formed of the above-mentioned gas barrier coating composition are laminated onto a synthetic resin film.
As the above-mentioned vapor-deposited film, a vapor-deposited film of an inorganic oxide by a chemical vapor deposition method and/or a physical vapor deposition method is preferred.
REFERENCES:
patent: 6171663 (2001-01-01), Hanada et al.
patent: 2-47144 (1990-02-01), None
patent: 3-164249 (1991-07-01), None
patent: 6-192454 (1994-07-01), None
patent: 6-329821 (1994-11-01), None
patent: 7-233293 (1995-09-01), None
patent: 8-216325 (1996-08-01), None
patent: 9-193284 (1997-07-01), None
patent: 2000-52475 (2000-02-01), None
Ishikawa Satoshi
Izawa Hideki
Shiho Hiroshi
Yamamoto Hiroshi
Yamazaki Takuya
JSR Corporation
Nakarani D. S.
LandOfFree
Gas barrier coating composition, process for producing the... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Gas barrier coating composition, process for producing the..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Gas barrier coating composition, process for producing the... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3181139