Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
1999-08-18
2001-02-27
Cain, Edward J. (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
C423S335000, C423S625000, C428S404000, C428S405000, C428S406000, C428S407000, C523S214000, C523S216000, C523S217000
Reexamination Certificate
active
06194489
ABSTRACT:
FIELD OF THE INVENTION
Thermoplastic resins such as a polycarbonate resin (PC), a polybutylene terephthalate resin (PBT), a polyethylene terephthalate resin (PET), a blend thereof and a mixture obtained by blending one or a plurality of the above resins with other resins bring about thermal decomposition when they are heated and molten in various molding processes and lower in mechanical properties. The present invention relates to a resin additive which prevents thermal decomposition thereof and to a resin additive which prevents thermal decomposition (reduction in molecular weight) and does not reduce the impact strength to a large extent.
DESCRIPTION OF THE RELATED ART
Resin materials, particularly respective resins of PC, PBT and PET are heavily reduced in a molecular weight in melting by heating, so that the molecular weights have notably been reduced by heat given in various molding processes and shear stress exerted in kneading. Accordingly, it was difficult to recycle sprues and runners produced in molding as well as recycling of the products. According to researches made by the present inventors, the resins described above could be inhibited from lowering in a molecular weight in heating and melting by adding inorganic particles subjected to surface treatment with tannic acid to the resins, but there was the problem that the IZOD impact strengths were reduced.
Intensive researches of a resin additive of tannic acid continued by the present inventors have resulted in finding that thermoplastic resins can be inhibited from lowering in a molecular weight in heating and melting and prevented from lowering in an IZOD impact strength by adding to the above resins, a resin additive obtained by subjecting inorganic particles to surface treatment with tannic acid and further subjecting them to surface treatment with a coupling agent or subjecting the inorganic particles to surface treatment with tannic acid and then subjecting them to surface treatment with a phenone compound or saccharides, followed by further subjecting them to surface treatment with a coupling agent.
SUMMARY OF THE INVENTION
Accordingly, the first object of the present invention is to provide a resin additive which is obtained by allowing the surface of inorganic particles to be contacted with a tannic acid solution and further treating them with a coupling agent or subjecting the inorganic particles subjected to surface treatment with tannic acid to surface treatment with a phenone compound or saccharides and subsequently subjecting them to surface treatment with a coupling agent and which not only can thermally stabilize a resin but also can prevent the resin from lowering in an IZOD impact strength. According to the present invention, there can be provided, a resin additive which can thermally stabilize the resin by tannic acid and reduce the impact stress by the saccharides or phenone compound and which strengthens the bond of the inorganic particles with the matrix resin by the coupling agent to thereby prevent not only a reduction in the molecular weight caused by a thermal degradation of the resin but also a reduction in the IZOD impact strength.
The second object of the present invention is to provide a resin additive which not only provides a thermoplastic resin with heat stability in heating and melting the resin but also prevents the resin from lowering in an IZOD impact strength.
Further, the third object of the present invention is to provide a resin additive which not only provides a thermoplastic polycarbonate resin, a thermoplastic polyester resin or a thermoplastic resin comprising these polycarbonate resin and polyester resin with heat stability in heating and melting the resin but also prevents the resin from lowering in an IZOD impact strength.
Another object of the present invention is to provide a resin additive which makes it possible to recycle the product.
Still another object of the present invention shall become more distinct from the following explanations.
DISCLOSURE OF THE INVENTION
It has been found that the preceding objects of the present invention can be achieved by:
1. a resin additive prepared by subjecting inorganic particles to surface treatment with tannic acid and further subjecting them to surface treatment with a coupling agent,
2. a resin additive prepared by subjecting inorganic particles to surface treatment with tannic acid and then subjecting them to surface treatment with a phenone compound, followed by further subjecting them to surface treatment with a coupling agent, or
3. a resin additive prepared by subjecting inorganic particles to surface treatment with tannic acid and then subjecting them to surface treatment with saccharides, followed by further subjecting them to surface treatment with a coupling agent.
DETAILED DESCRIPTION OF THE INVENTION
The resin additive of the present invention shall be explained below in further details.
The inorganic particles used in the present invention shall not specifically be restricted and may be any inorganic particles as long as they can effectively be used for the objects of the present invention. Specific examples thereof include silica salts such as silica, anhydrous silica, silica gel, talc, clay, mica aluminum silicate and kaolinite, alumina and salts thereof such as aluminates. In addition thereto, inorganic substances staying in a glass state, that is, glass can also be used as an inorganic material in the present invention. Various materials such as oxide glass, particularly silicate glass, powder of glass fiber, glass beads, glass balloon and fly ash can be used. Further, carbon and powder of carbon fiber can be used as well for the inorganic particles. Among them, silica powder is produced in nature and therefore is excellent in profitability, so that it is particularly preferably used. The particle size and form of the inorganic particles used shall not specifically be restricted and are suitably selected and used according to the kind and the use purposes thereof.
Next, tannic acid used in the present invention is a polyhydric phenol compound which forms gallic acid represented by a formula (2) by hydrolysis and is contained widely in plants in the natural world. It is said that to be roughly classified, tannic acid includes two kinds of a hydrolysis type and a condensation type, and both are natural compounds, so that a lot of tannic acid having different structures are present. Tannic acid used in the present invention may be either type. Further, tannic acid is also called tannin and shall not specifically be distinguished therefrom in the present invention.
Chinese gallotannin which is typical hydrolysis type tannin is shown by a formula (1). Further, to specify Chinese gallotannin, it has been confirmed that in Chinese gallotannin, 10 gallic acid groups coordinate in the circumference of a glucose residue on the same surface and 2 gallic acid groups are bonded in a vertical direction. However, the center of the compound is not necessarily restricted to glucose and may be a cellulose base compound in a certain case. Further, a didepside of gallic acid represented by the formula (2) obtained by hydrolysis of tannic acid can be used as well. As described above, tannic acid is a compound contained widely in plants in the natural world, and therefore it is readily presumed that tannic acid is partially different in a chemical structure. In the present invention, hydrolysis type tannic acid and condensation type tannic acid can synonymously be used without putting a distinction therebetween. Quebro tannin and Turkish tannin are shown as tannins having different chemical structures by a formula (3) and a formula (4).
Polyhydric phenol compounds having a dye-fixing effect and a tanning effect for leather are called ┌synthetic tannins┘, and among these synthetic tannins, the compounds capable of being effectively used for the objects of the present invention can be used as well in the present invention. At present, tannic acid is used for ink as a daily living article, medically for a hemostatic
Kanno Maki
Nikkeshi Susumu
Cain Edward J.
Tohoku Munekata Co Ltd
LandOfFree
Resin Additive does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Resin Additive, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Resin Additive will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2573810