Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Polymers from only ethylenic monomers or processes of...
Reexamination Certificate
2000-05-08
2002-10-01
Wu, David W. (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Polymers from only ethylenic monomers or processes of...
C526S131000, C526S290000, C526S346000
Reexamination Certificate
active
06458902
ABSTRACT:
TECHNICAL FIELD
The present invention relates to processes for preparing hydrogenated C
9
petroleum resins and hydrogenated C
9
petroleum resins obtainable by said processes.
BACKGROUND ART
Conventionally, C
9
petroleum resins are prepared by polymerizing C
9
fractions obtained by naphtha cracking or the like, in the presence of a phenol (a molecular weight modifier) using a boron trifluoride phenol complex (a Friedel-Crafts catalyst). Hydrogenated C
9
petroleum resins are obtained by hydrogenating the C
9
petroleum resins under pressure, and because of their good initial color, tack, adhesion and high compatibility with other resins, hydrogenated C
9
petroleum resins are mixed and melted with various plastics, rubbers and oil-soluble materials for use as tacky adhesives or other adhesives, sealing agents, paints, inks, polyolefin films, plastic moldings and the like. Further, hydrogenated C
9
petroleum resins are lighter in color, have less odor, and are higher in heat stability and weather resistance, than unhydrogenated C
9
petroleum resins, dicyclopentadiene (DCPD) petroleum resins and C
5
petroleum resins.
Although hydrogenated C
9
petroleum resins have excellent properties as described above, there is a demand for further improvement in their color and stability characteristics such as thermal discoloration resistance and light resistance, in the fields where the color of resins is particularly important, such as the fields of sanitary applications, foods and clear sealants. Further, conventional hydrogenated C
9
petroleum resins are highly fluorescent, and since fluorescent materials are suspected of being carcinogenic, reduction of florescence of hydrogenated C
9
petroleum resins is also demanded.
Hydrogenated C
9
petroleum resins can be improved in thermal discoloration resistance and light resistance and reduced in fluorescence by, for example, adding increased amounts of generally used additives, such as antioxidants and UV absorbers. However, this technique is economically disadvantageous since these additives are expensive. Further, addition of an increased amount of an antioxidant improves the thermal stability only to a limited extent and tends to impair the light resistance, hence undesirable from the viewpoints of performance characteristics and properties. Furthermore, although UV absorbers improve the light resistance and reduce the fluorescence, they are yellowish in color and thus impair the initial color of the resins.
Known substitutes for hydrogenated C
9
petroleum resins include hydrogenated pure monomer resins prepared by hydrogenating aromatic pure monomer resins (resins obtainable by polymerizing aromatic pure monomers) such as low-molecular styrene resins, &agr;-methylstyrene resins and isopropenyltoluene resins. The hydrogenated pure monomer resins are light in color, excellent in thermal discoloration resistance and light resistance, and less fluorescent. However, low-molecular styrene resins are prone to have a molecular weight greater than ordinary C
9
petroleum resins, and therefore tend to be less compatible with polymers and elastomers. Further, it is difficult to prepare hydrogenated &agr;-methylstyrene resins or hydrogenated isopropenyltoluene resins, since decomposition reaction is likely to proceed during hydrogenation, due to the methyl group present at the &agr;-position of the benzene ring. Moreover, all of the above resins are prepared from highly purified monomers, and thus are expensive and unsuitable for practical use.
DISCLOSURE OF INVENTION
The main object of the present invention is to provide a hydrogenated C
9
petroleum resin. and a process for preparing the same, said hydrogenated C
9
petroleum resin retaining characteristics of known hydrogenated C
9
petroleum resins and being excellent in thermal stability and light resistance and remarkably low in fluorescence.
The present inventors conducted extensive research in view of the above problems, and found that thermal stability and other properties of hydrogenated C
9
petroleum resins are adversely affected by polymerization catalysts (for example, a boron trifluoride phenol complex) used for preparation of C
9
petroleum resins as the starting materials of hydrogenated C
9
petroleum resins, or phenols used as molecular weight modifiers during polymerization. Based on this finding, they further found that hydrogenated C
9
petroleum resins obtained by the processes described below accomplish the above object.
The present invention provides the following processes for preparing hydrogenated C
9
petroleum resins, hydrogenated C
9
petroleum resins obtainable by said processes, tackifier, additive for plastics, and adhesive composition.
1. A process for preparing a hydrogenated C
9
petroleum resin, comprising hydrogenating a C
9
petroleum resin obtained by polymerizing polymerizable monomers of a C
9
fraction using a non-phenolic Friedel-Crafts catalyst in the presence or absence of a non-phenolic molecular weight modifier.
2. A process according to Item 1, wherein the non-phenolic Friedel-Crafts catalyst is boron trifluoride or a boron trifluoride ether complex.
3. A process according to Item 1 or 2, wherein the polymerizable monomers include up to 20 wt. % of a monomer fraction having a higher boiling point than indene.
4. A process according to any one of Items 1 to 3, wherein the polymerizable monomers include up to 20 wt. % of a monomer fraction having a higher boiling point than indene, at least 50 wt. % of vinyltoluene, and up to 20 wt. % of indene.
5. A process according to any one of Items 1 to 4, wherein the hydrogenation degree of the aromatic nuclei of the hydrogenated C
9
petroleum resin is at least 50%.
6. A hydrogenated C
9
petroleum resin obtainable by a process according to any one of Items 1 to 5.
7. A tackifier comprising a hydrogenated C
9
petroleum resin according to Item 6.
8. An additive for plastics, comprising a hydrogenated C
9
petroleum resin according to Item 6.
9. An adhesive composition comprising a tackifier according to Item 7 and a base resin for adhesives.
According to the process of the present invention, a hydrogenated C
9
petroleum resin is prepared by hydrogenating a C
9
petroleum resin obtained by polymerizing polymerizable monomers of a C
9
fraction. The process of the invention can be carried out by following the steps of conventional techniques for preparing hydrogenated C
9
petroleum resins, except that the C
9
petroleum resin is one obtained using a non-phenolic Friedel-Crafts catalyst in the presence or absence of a non-phenolic molecular weight modifier. The non-phenolic Friedel-Crafts catalyst and non-phenolic molecular weight modifier are employed so that the C
9
petroleum resin does not contain detectable amounts of phenols. Thus, the C
9
petroleum resin may contain phenols in a proportion smaller than the detection limit. Phenols can be detected by, for example, a color test using iron (III) chloride (“Yukikagobutsu Kakuninhou (Organic Compound Detection Method) I”, Chap. 1, pp. 9-12).
Phenols usable as phenolic Friedel-Crafts catalysts or phenolic molecular weight modifiers include C
6
-C
20
phenols having a —OH group in the molecule, such as phenol, and cresol, xylenol, p-tert-butylphenol, p-octylphenol, nonylphenol and like alkyl substituted phenols.
Any Friedel-Crafts catalysts free from phenolic components can be employed for preparation of the C
9
petroleum resin for use in the invention, without limitation. Specific examples of such catalysts include boron trifluoride, boron trifluoride ethyl ether complexes, boron trifluoride butyl ether complexes, boron trifluoride acetic acid complexes, aluminum chloride, titanium tetrachloride, tin tetrachloride and like Lewis acids; and sulfuric acid, phosphoric acid, perchloric acid and like protonic acids. From the standpoint of industrial availability, boron trifluoride and boron trifluoride ethyl ether complexes are preferred. If a Friedel-Crafts catalyst containing a phenol, such as a boron trifluoride phenol complex, is used, the hydrogenat
Keshi Hirokazu
Nagahara Eiji
Okazaki Takumi
Arakawa Chemical Industries Ltd.
Baker & Botts LLP
Cheung William K
Wu David W.
LandOfFree
Process for producing hydrogenated C9 petroleum resin and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for producing hydrogenated C9 petroleum resin and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for producing hydrogenated C9 petroleum resin and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2959553