Hydrogenation process

Details Hydrogenation process Hydrogenation process

2000-06-13

2002-08-13

Lipman, Bernard (Department: 1713)

Synthetic resins or natural rubbers -- part of the class 520 ser

Synthetic resins

Mixing of two or more solid polymers; mixing of solid...

C525S327900, C525S333700, C525S339000

Reexamination Certificate

active

06433104

ABSTRACT:

FIELD
This invention relates to an improved resin hydrotreating process which maintains resin softening point and aromaticity as well as catalyst lifetime. The process is particularly useful for hydrotreating resins containing halogen residue.
BACKGROUND
Petroleum resin hydrogenation processes are well known. Hydrocarbon resins obtained from thermal or catalytic polymerization of olefin and diolefin containing streams are often dark in color which is undesirable for many applications. Hydrogenation processes are used to lighten the color and improve heat and ultraviolet light stabilities. Hydrogenation processes, however, have their own limitations. For example, catalytically polymerized resins may contain halogen residue derived from the catalyst. These catalyst residues tend to accumulate on the acidic surface of the hydrogenation catalyst. This accumulation in combination with hydrogenation conditions tends to hydrocrack the resin and deteriorate key resin properties such as resin softening point and reduces product yield. We have discovered a unique hydrogenation process that reduces resin color while maintaining softening point and catalyst life.
U.S. Pat. No. 4,629,766 describes a hydrogenation process intended for thermally polymerized resins that uses high hydrogen pressure to improve yields, color and heat stability.
U.S. Pat. No. 5,491,214 describes a batch hydrogenation process that uses specific catalysts designed to hydrogenate only color bodies in the resin without hydrogenating the resin's carbon-carbon double bonds.
U.S. Pat. No. 5,552,363 describes a specific hydrogenation catalyst that is resistant to halogen contaminants in the resin. U.S. Pat. No. 5,820,749 also describes a specific hydrogenation catalyst designed primarily to increase productivity.
SUMMARY
The processes described herein generally enable hydrotreatment of resins on a continuous basis without prior treatment of the resins to remove catalyst residues. Process conditions are provided for different types of resin to limit cracking of the resin backbone while improving the resin color. In particular the processes of this invention are directed to a one-step hydrogenation process comprising:
(a) introducing hydrocarbon resin having from about 50 ppm by weight to about 2000 ppm by weight of one or more halogen residues into a reactor, said resin having a softening point X, where X is a temperature of from about 70° C. to about 150° C.;
(b) hydrotreating the resin in the reactor with a catalyst using pressure of not more than 2000 psi for a time period of at least 800 hours at a temperature in the range of from about 100° C. to about 350° C. thereby producing at least 350 tons of polymer per ton of catalyst; and
(c) recovering from the reactor hydrotreated resin having a softening point Y° C. of no less than X−8.
DESCRIPTION
This invention is directed to processes for hydrotreating hydrocarbon resin or rosin under suitable hydrotreating conditions, with a mono or bi-metallic catalyst system based on Group 6,7,8,9,10 and 11 elements (IUPAC notation Handbook of Chemistry and Physics, 70th Ed., 1989/1990) supported on an acidic support such as alumina. Hydrocarbon resins prepared from catalytic or thermally polymerized petroleum feed streams and hydrogenated according to the invention exhibit lighter color compared to the original and with aromaticity, softening point properties equivalent to the original resin.
The catalytically polymerized resins obtained from the polymerization of C
5
-C
10
with Friedel-Crafts or Lewis Acids catalysts and hence contain catalyst halogen residues. The processes described herein enable hydrotreatment of the resins on a continuous basis without prior treatment of the resins to remove catalyst residues. Process conditions are provided for different types of resin to limit cracking of the resin backbone while improving the resin color. Cracking deteriorates important physical properties such as resin softening point, molecular weights, decreases product yield and reduces effective catalyst life.
Although this hydrogenation process may be conducted batch-wise, it is uniquely suited to a one-step or one-stage, continuous, fixed-bed hydrogenation process. “One-step” or “one-stage” means that the entire hydrogenation is conducted in one reactor without further hydrogenation in a separate vessel and without any prior step to remove impurities such as halogen residues from the resin. Preferably the process is continuous and is conducted at a rate of at least 350 tons of polymer produced per ton of catalyst used for at least 800 hours, more preferably at least 1000 hours, even more preferably at least 1500 hours and most preferably at least 3000 hours.
In the most preferred process, hydrogenation is conducted using petroleum resins obtained from the cationic polymerization of steam-cracked naphtha using a Friedel-Crafts catalyst such as aluminum trichloride or boron trifluoride. Resins can also be obtained from thermal polymerization using cyclo-aliphatic or cyclo-aliphatic and aromatic feeds. The preferred resins are those known to be useful as tackifiers for adhesive applications and road-marking applications and polymer modification. Petroleum resins include hydrocarbon resins that have been modified with aromatic or terpene containing feedstream; hydrocarbon resins from pure aromatic monomers, the coumarone-indene resins and the polyterpenes resins. For additional description of feedstream derivation, monomer composition, methods of polymerization and hydrogenation, reference can be made to technical literature, e.g.
Hydrocarbon Resins,
Kirk-Othmer,
Encyclopedia of Chemical Technology,
4th Ed. v.13, pp. 717-743. The natural resins, rosins including gum rosins, wood rosin, and tall oil rosins can also be hydrotreated according to this process.
The hydrogenation process of this invention is particularly useful for hydrotreating halogen containing resins. Resins produced by Friedel-Crafts polymerization typically contain between about 50 ppm by weight and about 2000 ppm halogen residue, some contain between about 1000 ppm by weight and about 1500 ppm by weight halogen residue. As used herein, “halogen residue” means any compound containing one or more halogen atoms.
Petroleum resins are typically produced by thermally or catalytically polymerizing petroleum fractions. These polymerizations may be batch, semi-batch or continuous. Petroleum fractions containing aliphatic C
5
to C
6
linear, branched, alicyclic monoolefins, diolefins, alicyclic C
10
diolefins can be polymerized. The aliphatic olefins can comprise one or more natural or synthetic terpenes, preferably one or more of alpha-pinene, beta-pinene, delta-3-carene, dipentene, limonene or isoprene dimers. C
8
-C
10
aromatic olefinic streams containing styrene, vinyl toluenes, indene, methyl-indenes can also be polymerized as such or in mixture with the aliphatic streams.
Thermal polymerization is usually carried out at a temperature between 160° C. and 320° C., e.g., at about 250° C., for a period of 0.5 to 9 hours, typically 1.5 to 4 hours. Catalytic polymerization is usually carried out with a Friedel-Crafts or Lewis Acid catalyst such as metallic halides such as aluminum trichloride or boron trifluoride, aluminum tribromide or mixture thereof, as well as ternary complexes of the halides, aromatic compounds and hydrogen halides. A polymerization reaction is usually run at a temperature between −20° C. to 200° C., preferably between 0° C. and 120° C. and more preferably between 20° C. and 80° C. Catalytic polymerization is usually accomplished in a polymerization solvent and removal of solvent and catalyst by washing and distillation. The hydrotreating process of this invention is essentially useful for treating catalytically polymerized aliphatic or aromatic resins containing catalyst-derived halogen residue.
The polymeric resin so produced is dissolved in an inert, de-aromatized or non-de-aromatized hydrocarbon solvent such as Exxsol™ or Varsol™ or base white spirit in proportions varying from

Affiliated with

Also associated with

Rating

Hydrogenation process does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Hydrogenation process, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hydrogenation process will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2948919