Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
2001-08-02
2002-04-02
Henderson, Christopher (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
C524S127000, C524S203000, C524S155000, C524S560000, C524S601000
Reexamination Certificate
active
06365654
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
This invention relates to transparent resin compositions that absorb near infrared radiation (with wavelengths in the range of 780-1800 nm). More particularly, it relates to excellent transparent resin compositions capable of both efficiently absorbing near infrared radiation and efficiently transmitting visible light (380-780 nm).
BACKGROUND OF THE PRIOR ART
Transparent resin materials with near infrared absorption characteristics possess both clearness and ability of heat radiation shielding by near infrared absorption. These features make them attractive as light-admitting materials for buildings, windows of transport vehicle, ceilings, doors, arcades, garages, sunrooms, greenhouses, etc.
Their ability of absorbing near infrared radiation also promises their uses in such applications as eye-protecting lenses and other safety glasses, infrared-sensitive filters, and photosensitive materials using semiconductor laser beam sources.
As a conventional transparent resin material with near infrared absorption characteristics, a polymer prepared by dissolving tungsten hexachloride and tin chloride in methyl methacrylates for polymerization is known (U.S. Pat. No. 3,692,688).
Other near infrared absorbers are, for example, a thiol-nickel complex (Japanese Patent Application Publication (Kokoku) No. 60-21294), chromium-cobalt complex salt (Japanese Patent Application Publication (Kokoku) No. 60-42269), anthraquinone derivative (Japanese Patent Application Public Disclosure (Kokai) No. 61-115958), and squarilium compound (Japanese Patent Application Public Disclosure (Kokai) No. 61-218551).
Instead of adding a near-infrared absorber to resins, vapor deposition of aluminum, silver or other metal on one side of a polyethylene terephthalate film has also been practiced to manufacture a heat radiation reflecting film. The reflecting film, when laminated to a transparent resin material, achieves the dual effects of reflecting a heat radiation from the outside and suppressing an increase of the internal temperature.
Problems to be Solved by the Invention
The near infrared-absorbing, transparent resin materials of the prior art have had problems. For example, the near infrared absorbers of organic type are inferior in durability and have difficulties in sustaining their effect. Meanwhile, the absorbers of complex type are durable but absorb part of the radiation in the visible region too, and they often are colored and hence limited in use depending on the application.
Another prior art system of tungsten hexachloride and tin chloride is a good absorber of near infrared radiation but presents a problem of fading upon standing for many hours in the dark.
The heat radiation reflecting film obtained by the above-mentioned metal vapor deposition rather than by the addition of a near infrared absorber causes a problem of dimming rooms when it is laminated to window glasses: The metal vapor deposition layer reflects not merely heat radiation but visible light too, thus reducing the light transmission through the film. Moreover, adhering the film to a transparent resin material with adhesive tends to entrap air between the adhered surfaces. The entrapped air forms “blisters”, which can swell. This can seriously reduce the transmission or cause the film to come off easily. A further problem is the tendency of metal oxidation with time, which leads to discoloration or diminished heat radiation reflectivity.
SUMMARY OF THE INVENTION
The present inventors have intensively searched for solutions to the foregoing problems. It has now been found, as a result, that mixing a transparent thermoplastic resin with a specific thiuram compound and/or a metal dithiocarbamate compound and a specific copper compound gives a transparent resin composition capable of efficiently absorbing near infrared radiation and also efficiently transmitting visible light and which, moreover, exhibits excellent durability. The present invention is predicated upon this finding.
In brief, the subject of the invention is a transparent resin composition with excellent near infrared absorption characteristics which comprises 100 parts by weight of a transparent thermoplastic resin, about 0.01 to about 2 parts by weight of a thiuram compound of the general formula (A):
in which R
1
and R
2
are the same or different and represent monovalent groups selected from the group consisting of hydrogen, alkyl, cycloalkyl, aryl, aralkyl, and 5- or 6-membered heterocyclic groups, each of which may contain one or more substituents, or form together a ring, and m and n are integers of 1 to 4 each, and/or a metal dithiocarbamate compound of the general formula (B):
in which R
3
and R
4
are the same or different and represent monovalent groups selected from the group consisting of hydrogen, alkyl, cycloalkyl, aryl, aralkyl, and 5- or 6-membered heterocyclic group, each of which may contain one or more substituents, or form a ring, M is Zn, Co, Ni, Fe, Na or K, and p is an integer of 1 to 4 equivalent to the valency of M, and about 0.01 to about 2 parts by weight of a copper compound of the general formula (C):
X
q
Cu (C)
in which X is sulfur, fluorine, chlorine, —CN, phthalocyanyl, sodium chlorophyllin, bisacetylacetate or R
5
—Y (wherein R
5
is a monovalent group selected from the group consisting of hydrogen, alkyl, cycloalkyl, aryl, aralkyl, and heterocyclic group, each of which may contain one or more substituents, and Y is —COO, —SO
4
, —SO
3
, —PO
4
or —O), and q is 1 or 2.
Another subject of the invention is a transparent resin composition with excellent near infrared absorption characteristics which comprises 100 parts by weight of a transparent thermoplastic resin, about 0.01 to about 2 parts by weight of a copper dithiocarbamate compound of the general formula (D):
in which R
6
and R
7
are the same or different and represent monovalent groups selected from the group consisting of hydrogen, alkyl, cycloalkyl, aryl, aralkyl, and 5- or 6-membered heterocyclic group, each of which may contain one or more substituents, or form together a ring, and 0 to about 2 parts by weight of a copper compound of the general formula (C) above.
DETAILED DESCRIPTION OF THE INVENTION
The invention will now be described in more detail.
Transparent thermoplastic resin which may be used for the present invention includes, but are not limited to, transparent resin material such as polycarbonate, polyester, methacrylic, styrene, polyvinyl chloride, polyolefin and polyamide resin. These resins may be used singly or as a mixture of two or more.
The term polycarbonate resin as used herein means the polymers obtained either by the phosgene process in which any of varied dihydroxydiaryl compound is reacted with phosgene or by the ester exchange process in which a dihydroxydiaryl compound is reacted with carbonic ester such as diphenyl carbonate. Typical of them is a polycarbonate resin produced from 2,2-bis(4-hydroxyphenyl)propane (bisphenol A).
Examples of the dihydroxydiaryl compounds, besides bisphenol A, are: bis(hydroxyaryl)alkanes, such as bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)octane, bis(4-hydroxyphenyl)phenylmethane, 2,2-bis(4-hydroxyphenyl-3-methylphenyl)propane, 1,1-bis(4-hydroxy-3-tert.butylphenyl)propene, 2,2-bis(4-hydroxy-3-bromophenyl)propane, 2,2-bis(4-hydroxy-3,5-dibromophenyl)propane and 2,2-bis(4-hydroxy-3,5-dichlorophenyl)propane; bis(hydroxyaryl)cycloalkanes, such as 1,1-bis(4-hydroxyphenyl)cyclopentane and 1,1-bis(4-hydroxyphenyl)cyclohexane; dihydroxydiaryl ethers, such as 4,4′-dihydroxydiphenyl ether and 4,4′-dihydroxy-3,3′-dimethyldiphenyl ether; dihydroxydiaryl sulfides, such as 4,4′-dihydroxydiphenyl sulfide; dihydroxyaryl sulfoxides, such as 4,4′-hydrodiphenyl sulfoxide and 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfoxide; and dihydroxydiaryl sulfones, such as 4,4′-dihydroxydiphenyl sulfone and 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfone.
Such a dihydroxyar
Kawamoto Naoyoshi
Tomari Yukio
Gary C. Cohn PLLC
Henderson Christopher
Sumitomo Dow Limited
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