HYDROGENATION PROCESS

Abstract: This invention relates to an improved resin hydrotreating process that maintains resin softening point and aromaticity as well as catalyst lifetime. The process is particularly useful for hydrotreating resins containing one or more halogen residues. Pressures are maintained at 2000 psi or less. Color is substantially reduced while softening point is not decreased by more than 8 DEG C.

Description: HYDROGENATION PROCESS FIELD This invention relates to an improved resin hydrotreating process that 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 diolefϊn- containing streams are often dark in color, which is undesirable for many applica- tions. Hydrogenation processes lighten the color and improve heat and ultraviolet light stabilities. But hydrogenation processes have their own limitations. For example, catalytically polymerized resins may contain halogen residue from the catalyst. These residues tend to accumulate on the hydrogenation catalyst's acidic surface. This accumulation, in combination with hydrogenation conditions, hy- drocracks the resin and deteriorates 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. Patent No. 4,629,766 describes a hydrogenation process intended for thermally polymerized resins that uses high hydrogen pressure to improve yield, color, and heat stability. U.S. Patent 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. Patent No. 5,552,363 describes a specific hydrogenation catalyst that is resistant to resin halogen contaminants. U.S. Patent No. 5,820,749 also describes a specific hydrogenation catalyst primarily designed to increase productivity. SUMMARY The described processes generally allow resin hydrotreatment on a con- tinuous basis without prior catalyst residue removal. Process conditions are provided for different types of resin that limit resin backbone cracking while improving the resin color. In particular, the processes of this invention are directed to a one-step hydrogenation process comprising: • introducing hydrocarbon resin having from 50 ppm by weight to 2000 ppm by weight of one or more halogen residues into a reactor, said resin having an initial softening point of from 70-150 °C; • hydrotreating the resin in the reactor with a catalyst using pressure of not more than 2000 psi for at least 800 hours at a tem- perature from 100-350 °C thereby producing at least 350 tons of polymer per ton of catalyst; and • recovering from the reactor hydrotreated resin having a final softening point depressed less than 8 °C below the initial softening point, i.e. the final softening point is greater than the initial softening point minus 8 °C. DESCRIPTION This invention is directed to processes for hydrotreating hydrocarbon resin or rosin under suitable conditions with a mono- or bi-metallic catalyst system based on Group-6,-7,-8,-9,-10, or -11 elements that are supported on an acidic support such as alumina. The described processes allow continuous resin hydro- treatment without prior catalyst residue removal. 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 level and softening point equivalent to the original resin. The resins obtained from polymerizing C 5 -C 10 substrates with Friedel- Crafts or Lewis acid catalysts contain halogen residue from the catalyst. Process conditions are provided for different resin types and are chosen to limit resin backbone cracking while improving resin color. Cracking deteriorates important physical properties such as resin softening point and molecular weight, decreases product yield, and reduces effective catalyst life. Although these hydrogenation processes may be conducted batch-wise, they are uniquely suited to one-step or one-stage, continuous, fixed-bed processes. "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 produced polymer per ton of catalyst, and the process can run without catalyst regeneration for at least 800 hours, more preferably at least 1,000 hours, even more preferably at least 1,500 hours, and most preferably at least 3,000 hours. In the most preferred process, hydrogenation is conducted using petroleum resins obtained from polymerizing steam-cracked naphtha using a Friedel- Crafts catalyst such as aluminum trichloride or boron trifluoride. Thermal polymerization using cyclo-aliphatic or mixed cyclo-aliphatic/aromatic feeds also produces useful resins. The preferred resins are those known to be useful as tackifi- ers for adhesive and road-marking applications and polymer modification. Petroleum resins include aromatic- or terpene-modified hydrocarbon resins; pure- aromatic-monomer hydrocarbon resins, coumarone-indene resins, and polyterpene resins. For additional description of feedstream derivation, monomer composition, polymerization methods, and hydrogenation methods, see, e.g. Hydrocarbon Resins, Kirk-Othmer, Encyclopedia of Chemical Technology, 4th Ed. v.13, pp. 717-743. The natural resins and rosins, including gum rosins, wood rosin, and tall oil rosins, can also be hydrotreated according to this process. Invention hydrogenation processes are particularly useful for hydro- treating halogen-containing resins. Resins produced with Friedel-Crafts catalysts typically contain between 50 ppm by weight and 2000 ppm catalyst halogen residue, some contain between 1000 ppm by weight and 1500 ppm by weight halogen residue. "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 -C 5 linear, branched, or alicyclic monoolefϊns; diolefms; or alicyclic CJQ diolefins can be polymerized. Aliphatic olefϊns can contain one or more natural or synthetic terpe- nes, preferably one or more of α-pinene, β-pinene, Δ-3-carene, dipentene, li- monene or isoprene dimers. Cs-Cio aromatic olefinic streams containing styre- nes, vinyl toluenes, indenes, or methyl-indenes can also be polymerized as such or as mixed with the aliphatic streams. Thermal polymerization usually occurs between 160 to 320 °C, e.g., at 250 °C, for 0.5-9 hours, typically 1.5^1 hours. Catalytic polymerization usually employs Friedel-Crafts or Lewis acid catalysts such as metallic halides including aluminum trichloride or boron trifluoride, aluminum tribromide or their mixtures, as well as ternary halide/aromatic/hydrogen-halide complexes. Polymerization reactions are usually run at -20 to 200 °C, preferably 0 to 120 °C and more preferably 20 to 80 °C. Polymerization is usually conducted in a solvent. Washing or distillation typically removes the solvent and catalyst. Invention processes are useful for treating catalytically polymerized aliphatic or aromatic resins that con- tain catalyst-derived halogen residue. The produced resin is dissolved in an inert, de-aromatized or non- de- aromatized hydrocarbon solvent such as Exxsol or Narsof , or base white spirit in proportions varying from 10-60% and preferably around 30% by weight polymer. Hydrogenation is then conducted in a fixed-bed, continuous reactor with an upflow or downflow feed, liquid phase or trickle-bed operation. Hydrogenation or hydrotreating generally use reaction temperatures from 100 to 350 °C, preferably from 150 to 300 °C, more preferably from 160 to 270 °C. The reactor hydrogen pressure should not exceed 2000 psi, preferably 1500 psi, and most preferably 1000 psi. The hydrogenation pressure depends on hydrogen purity, and the overall reaction pressure should be higher if the hydrogen contains impurities. Typically, the optimal pressure is between 750-1500 psi, preferably between 800-1000 psi. The hydrogen-to-feed volume ratio in the reactor under standard conditions (25°C, 1 atm) typically ranges from 20-200. Catalyst activity typically decreases over time due to carbonaceous fouling of the catalyst support. This fouling can be partially eliminated or removed by regenerating the catalyst with hydrogen at temperatures between 310 to 350 °C. Pressures from 60-180 bar can be used. This regeneration is best accomplished without hydrocarbon feed to the reactor, e.g., when the hydrogenation process is interrupted. Typically, the reactor is fed with an inert solvent such as Exxsol ® or Narsol ® during regeneration. Catalysts employed for resin hydrogenation are typically supported monometallic and bimetallic catalysts systems based on Group-6,-7,-8,-9,-10 and -11 elements. Catalysts based on cobalt, nickel, tungsten, palladium, copper, or zinc are particularly suitable. The catalyst preferably used in this process is a hy- drodesulphurization catalyst prepared by supporting nickel and tungsten oxides onto alumina, preferably a high surface area alumina such as γ-alumina. The preferred components are nickel and tungsten on a γ-alumina support. Metal concentration in the catalyst is important for good performance. The alumina support's pore size distribution is also important for good performance. Catalyst metal con- centration can be as low as 2-4 weight percent nickel oxide (ΝiO) and 10-16 weight percent tungsten oxide (WO 3 ). The metal concentration can go as high as 5-10 weight percent nickel and 20-25 weight percent tungsten. The catalyst is prepared such that the small-pore pore volume (those with 15-300 A radius) is less than 70% of the total pore volume, and that the large-pore or channel volume (with radii of 10,000 to 75,000 A) are at least 10% of the total pore volume. This results in a fresh catalyst surface area of the support typically in the range of 120- 300 m 2 /g. Other suitable catalysts are detailed in U.S. Pat. No. 5,820,749. Particularly suitable catalysts described in this patent include those comprising nickel and/or cobalt and one or both of molybdenum or tungsten on a support. A suitable support comprises porous, refractory, substrate particles having: • a mean, maximum diffusion path length less than or equal to twice the hydraulic radius; • a pore volume distribution in which • pores having diameters >150,000 A (1.5xl0 -5 m) constitute greater than 2% of the total volume, • pores having diameters >20,000 A and < 150,000 A constitute greater than 1% of the total volume, and • pores having diameters >2,000 A (2.0x10 "7 m) and <20,000 A (2.0xl0 "6 m) constitute greater than 12% of the total volume; and • a total pore volume of from 45-86% of the total volume of the substrate particles. The catalyst can be prepared by mixing the support material with water- soluble compounds of nickel and/or cobalt and either molybdenum or tungsten as described in U.S. Pat. No. 5,820,749. Suitable catalyst supports are high-surface- area alumina such as η -alumina and γ-alumina. After impregnation, the support containing the nickel and/or cobalt and tungsten or molybdenum compounds is dried to remove water or other solvent. The dried support containing the nickel and/or cobalt and tungsten or molybdenum compounds is heated to decompose the metal compounds to their oxides. Suitable temperatures range from 300 to 550 °C. The amount of nickel oxide and/or cobalt oxide on the support ranges from 2% to 10%> by weight. The amount of tungsten or molybdenum oxide on the support ranges from 5% to 25% by weight. Preferably the catalyst contains 4% to 7% by weight nickel oxide and 18% to 22%) by weight tungsten oxide. Typical catalyst activators include sulfiding agents in the presence of hydrogen. Useful sulfur compounds include H 2 S, carbon disulfide, methyldisul- fide, ethyldisulfide, propyldisulfide, isopropyldisulfide, butyldisulfide, tertiary butyldisulfide, thianaphthene, thiophene, secondary dibutylsulfide, tertiary butyl- sulfide, dithiols and sulfur-bearing gas oils. Any other organic sulfur source that can be converted to H 2 S over the catalyst in the presence of hydrogen can be used. These catalysts can also be activated by an organo-sulfur process as described in U.S. Pat. No. 5,530,917. In addition an alkali promoter may be used with the metal compounds, particularly if improved halogen resistance is sought. Promoters include metals from Groups 1-3 of the periodic table including the lanthanides and actinides. The preferred promoters are typically lanthanum and potassium. The alkali promoters may be used in amounts of as low as 0.25-1 % and as high as 3-10% by weight. Invention hydrogenation processes provide commercially acceptable resin decolorization while avoiding or limiting resin backbone cracking due to hydrochloric acid formation caused by resin dehalogenation and acidic support surface. Because most of the halogen, typically chlorine, passes through the- reactor rather than accumulating on the catalyst bed, not only is cracking reduced, but catalyst life is greatly increased. After hydrogenation, the reactor mixture may be flashed and separated to recycle solvent and hydrogen and to recover the hydrogenated resin. The reactor mixture is flashed or distilled in an oxygen-free or oxygen-reduced atmosphere to separate the solvent, and afterwards may be steam distilled to separate oligomers, preferably while limiting resin temperature to 250 °C or below to avoid degrading the color and other resin properties. Resins thus obtained have a color of 5 YI to 40 YI depending on the initial color and resin structure. Using invention processes, the color is typically reduced by 30- 80%, preferably by at least 40%), more preferably by at least 50%. The final softening point after this hydrogenation process should not di- minish by more than 8°C, preferably not more than 5°C, even more preferably not more than 3°C and most preferably there should be no detectable reduction in resin softening point before and after hydrogenation using invention processes. In invention processes, resins are hydrogenated such that carbon-carbon double bonds are reduced at least 1.0% by weight. In one embodiment, the carbon-carbon double bonds are reduced at least 2.0% by weight, and in another at least 2.5%, or even at least 3.0%) by weight. The aromatic resins are hydrogenated such that the aromaticity level does not change by more than 5% by weight of equivalent styrene, preferably not more than 2%, even more preferably there should be no detectable change in aro- matic resin aromaticity before and after hydrogenation using invention processes. Resin aromaticity and carbon-carbon double bonds levels may be determined by H-NMR. Aromaticity is the integration of aromatic protons versus an internal standard (1,2 dichloroethane) given as weight percent of equivalent styrene, (104 g/mol). Carbon-carbon double bonds is the integration of olefmic pro- tons versus an internal standard (1,2 dichloroethane) given as weight percent of equivalent -CH=CH-, (26 g/mol). The resins obtained from this process preferably include hydrocarbon resins suitable as tackifiers for adhesive compositions, particularly adhesive compositions comprising polymeric base systems of either natural or synthetic elasto- mers including natural rubber, styrene block copolymers, ethylene-vinyl ester co- polymers, and metallocene polymers. Such compositions function in hot melt adhesives, pressure-sensitive adhesives, and adhesive emulsions. Resins obtained from this process can also be used in road-marking compositions, as ink resins, and as components in varnishes, paints and polymer modifiers. The following examples are presented to illustrate the foregoing discussion. Although the examples may be directed to certain embodiments of the present invention, they do not limit the invention in any specific respect. EXAMPLES Resin Characterization Resin color was determined using a Hunter Ultrascan colorimeter. Samples were prepared by weighing 10 grams (±0.02 g) of resin into a 20 ml. scintillation vial. An equal weight of toluene was added to the vial. The vial was then shaken until all of the resin dissolved. The solution was poured into a quartz cu- vette and analyzed for Yellowness Index (YI) color using the colorimeter. Resin color stability is the resin color after aging in a ventilated oven. A sample of 10 g (±0.1 g) of resin was heated at 175 °C (±0.5 °C) for 5 hours. The sample was allowed to cool to room temperature and the resin color was measured in the same way as the initial color. Resin Softening Point was determined according to the Ring & Ball method based on ASTM E-28 (Revision 1996). Resin melt viscosity was determined according to a method based on ASTM D-3236-88. The resin melt viscosity is the resin's apparent viscosity measured in millipascalseconds (mPas) with Spindle 21 and at 150 or 160 °C as specified in the Examples. Resin molecular weight was measured by Low-Temperature Size Exclusion Chromatography against polystyrene standards. A differential refractometer (DRI) and a UN-detector were used. The chromatography temperature was 40 °C, and tetrahydrofuran was the solvent. Molecular weight averages are reported as polystyrene-equivalent molecular weights. Resin aromaticity and carbon-carbon double bonds levels were determined by H-NMR. Aromaticity is the integration of aromatic protons versus an internal standard (1,2 dichloroethane) given as weight percent of equivalent styrene, (104 g/mol). Carbon-carbon double bond levels are the integration of ole- fϊnic protons versus an internal standard (1,2 dichloroethane) given as weight percent of equivalent -CH^CH-, (26 g/mol). Catalyst Sulfidation Procedure The catalyst was flushed for over 10 hours with as Exxsol ® D40. After flushing, the catalyst was activated by treating with dimethyldisulfi.de (DMDS) following known procedures. Hydrogenation Following Activation The resin feeds used in the Examples were solutions of commercially available, catalytically polymerized, hydrocarbon resin obtained by polymerizing C -C 6 olefins and conjugated diolefms and Cs- o aromatic olefins with alumi- num chloride at a temperature between 20 to 100 °C, preferably from 40 to 80 °C. The finished resin was further diluted in Exxsol ® D40 (Available from ExxonMobil Chemical Company). This resin solution was the feedstock. It was passed through the hydrotreating reactor at a temperature between 160 to 250 °C at a liquid-feed-to gas-volume ratio of 100 and at a space velocity of 1.0-1.5 volumes of feed per volume of catalyst per hour (VVH). The hydrogen flow rate was 27 Nl/hr and the hydrogen pressure was 870 psi. Product samples were collected from the reactor, the polymerizate was processed to hard resin and analyzed for neat resin properties such as initial color, color stability, softening point, molecular weight distribution, aromaticity level and carbon-carbon double bonds level. The weight of resin produced per weight of catalyst used (T/T) and run length (in hours) were recorded to compare the performance of the hydrotreating process versus the resin decoloring performance and softening point preservation. In the following examples data are provided for different resin types. Example 1 The feedstock, a fresh solution of Escorez ® 1102 RM (an aliphatic resin commercially available from ExxonMobil Chemical Company) diluted to 30 wt% resin in Exxsol ® D40 (available from ExxonMobil Chemical Company). The feedstock was hydrotreated on a freshly activated catalyst charge of a commercially available catalyst (UCI T-2557 E). Reactor inlet temperature was from 210 to 230 °C. Resin properties before and after hydrotreating and catalyst performance are reported in Table- 1. This example shows that the catalyst has been used for 1768 hours. After 1457 hours, the catalyst was regenerated through a catalyst hydrotreat. The obtained resin has a final softening point of 100 °C versus an initial softening point of 101 °C and a color of 32 YI versus 49 YI before treating. A second feedstock, a fresh solution of Escorez ® 2101 (an aromatic-modified resin commercially available from ExxonMobil Chemical Company) diluted to 30 wt% resin in Exxsol ® D40 was hydrotreated with the same catalyst charge, and the reactor inlet temperature was from 220 to 240 °C. The catalyst was used for another 901 hours. A second catalyst hydrotreat was performed after 2397 hours. The obtained resin had a final softening point of 88 °C versus an initial softening point of 93 °C and a color of 23 YI versus 79 YI. That resin's aromaticity level decreased by 0.5 wt% equivalent styrene. The total run time was 2669 hours or 1040 tons of resins per ton of catalyst. Example 2 The second feedstock of Example 1 was hydrotreated on a freshly activated catalyst charge of UCI T-2601 E (a catalyst, as described in U.S. Patent No. 5,820,749.) The inlet temperature of that test was 200 to 210 °C, lower than in the preceding Example. After 354 hours, a resin with 93 °C softening point and an initial color of 17 YI was obtained, (Table-2). The resin aromaticity level was unchanged. This Example shows that the lower severity of the run compared to the preceding one resulted in a product with improved initial color without change of softening point. In a second part of the test, ECR-373 (an aromatic-modified resin commercially available from ExxonMobil Chemical Company) was hydro- genated with the same catalyst charge. The inlet temperature of that test was 210 to 225 °C. A resin with 20 YI Initial Color (versus 80 YI before hydrogenation) and 91 °C final softening point (versus an 89 °C initial softening point) was obtained. The difference of 2°C higher for the hydrogenated product versus the pre- cursor results from the stripping of the resin solution into hard resin. Example 3 Similarly to the previous examples, four feedstocks made from different resins were consecutively hydrotreated on the same catalyst charge of UCI T-2601 E (a catalyst, as described in U.S. Patent No. 5,820,749.) These feedstocks were respectively, freshly made solutions of Escorez ® 2184, ECR-413, ECR-184 (commercially available aromatic-modified aliphatic resins available from ExxonMobil Chemical Company) and ECR-415 (an aliphatic resin commercially available from ExxonMobil Chemical Company) diluted to 30 wt% resin in Exxsol ® D40 (available from ExxonMobil Chemical). Run conditions and resins properties are reported in Table 3. The catalyst was regenerated once before switching to ECR-184 feedstock. The total run length was 951 hours or 476 tons of resin per ton of catalyst. Efficient resin decoloration is achieved without cracking as indicated by resin softening point and molecular weights. Example 4 Same as Example 3, four feedstocks were consecutively hydrotreated on a new catalyst charge of UCI T-2601 E. These feedstocks were respectively freshly made solutions of ECR-415 and Escorez ® 1102 RM (aliphatic resins commercially available from), Escorez ® 2203 (an aromatic-modified resin commercially available from ExxonMobil Chemical Company), and Escorez ® 1310 (an aliphatic resin commercially available from ExxonMobil Chemical) diluted to 30 wt%> resin in Exxsol ® D40 (commercially available from ExxonMobil Chemical). Process conditions and resin properties are reported in the Table-4. The last feedstock of Example 3, ECR-415, was hydrotreated using an inlet temperature of 180 °C, lower than in the preceding example. Less severe condition produced a resin with a higher softening point, 100 °C, versus 101 °C for the precursor with a significant color improvement: 22 YI versus 90 YI for the precursor. The catalyst was regenerated once before switching to Escorez ® 2203 feedstock. Table-1 Resin Type Escorez 1102 RM Escorez 2101 Inlet Temperature °C 210-230 220-240 Outlet Temperature °c 220-250 235-260 Run Length hours 1768 901 Resin / Cat ratio T/T 689 351 Soft. Point of the resin °C 101 93 Soft. Point after H2 °C 100 88 Initial Color YI 49 79 Initial Color after H2 YI 32 23 Heat Stability YI 121 148 Heat Stability after H2 YI 53 81 Melt Viscosity mPa.s 1970(*) 1335(#) Melt Viscosity after H2 mPa.s 1870(*) 676(#) Aromaticity (eq. styrene) wt% - 29 Aromaticity after H2 wt% - 28.5 residual -CH2=CH2- wt% 5.0 3.2 residual -CH2=CH2- after H2 wt% 3.0 0.7 Mn g/mol 1340 830 Mn after H2 g/mol 1400 800 Mw g/mol 3630 1680 M w after H2 g/mol 3570 1500 (*) at 160°C (#) at 150°C Table-2 Resin Type Escorez 2101 ECR-373 Inlet Temperature °C 200-210 210-225 Outlet Temperature °C 215-225 225-240 Run Length hours 354 482 Resin / Cat ratio T-T 167 228 Soft. Point of the resin °C 93 89 Soft. Point after H2 °C 93 91 Initial Color YI 79 80 Initial Color after H2 YI 17 20 Heat Stability YI 148 157 Heat Stability after H2 YI 112 105 Melt Viscosity at 150°C mPa.s 1335 Melt Viscosity after H2 mPa.s 1175 938 Aromaticity (eq. styrene) wt% 29 25 Aromaticity after H2 wt% 29 25 residual -CH2=CH2- wt% 3.2 3.9 residual -CH2=CH2- after H2 wt% 0.9 1.4 Mn g/mol 830 770 Mn after H2 g/mol 840 780 Mw g/mol 1680 1510 Mw after H2 g/mol 1600 1420 Table-3 Resin Type Escorez 2184 ECR-413 ECR-184 ECR-415 Inlet Temperature °C 210 210-220 169-185 190-200 Outlet Temperature °C 226 225-235 170-206 197-218 Run Length hours 284 374 139 154 Resin / Cat ratio TtT 139 190 70 77 Soft. Point of the resin °C 96 96 94 101 Soft. Point after H2 °C 97 95 97 95 Initial Color YI 81 81 16 90 Initial Color after H2 YI 11 38 9 10 Heat Stability YI 148 - - 149 Heat Stability after H2 YI 61 103 - - Melt Viscosity at 150°C mPa.s 1800 - - 3100 Melt Viscosity after H2 mPa.s 1225 - - - Aromaticity (eq. styrene) wt% 31 9 5.7 - Aromaticity after H2 wt% 31 9 5.7 - residual -CH2=CH2- wt% 2.7 3.6 6.1 - residual -CH2=CH2- after H2 wt% 0.5 3.1 4.6 - Mn g/mol 810 1180 1180 1100 Mn after H2 g/mol 800 1070 1180 1070 Mw g/mol 1810 2590 1890 2090 Mw after H2 g/mol 1560 2290 1850 1910 Table-4 Resin Type ECR-415 Escorez 1102 RM Escorez 2203 Escorez 1310 Inlet Temperature °C 180 196 170 170-180 Outlet Temperature °C 187 203 176 173-184 Run Length hours 168 282 310 234 Resin / Cat ratio T/T 83 141 154 116 Soft. Point of the resin °C 101 99 96 95 Soft. Point after H2 °C 100 102 96 96 Initial Color YI 90 42 24 32 Initial Color after H2 YI 22 19 6 10 Heat Stability YI 149 97 83 Heat Stability after H2 YI 93 85 - 73 Melt Viscosity at 150°C mPa.s 3100 - 1775 Melt Viscosity after H2 mPa.s - - 1887 Aromaticity (eq. styrene) wt% - - 8 Aromaticity after H2 wt% - - 7 residual -CH2=CH2- wt% 5.6 5.3 6.2 4.5 residual -CH2=CH2- after H2 wt% 3.3 3.7 3.9 4.2 Mn g/mol 1100 1330 1160 1180 Mn after H2 g/mol 1090 1350 1150 1210 Mw g/mol 2090 3870 2020 1810 Mw after H2 g/mol 2010 3750 1960 1860 The above Examples show that efficient hydrocarbon resin decoloration can be achieved without significant cracking provided that the appropriate hydro- treating conditions are selected. Pertinent conditions include inlet temperature and hydrogen pressure. Success is indicated by the small variation in resin softening point and molecular weights. While certain representative embodiments and details have been provided to illustrate the invention, it will be apparent to skilled artisans that various process and product changes from those disclosed in this specification may be made without departing from this invention's scope, which the appended claims define. These are considered to be within the scope of the current invention. All patents, test procedures, and other documents cited in this specification are fully incorporated by reference for all jurisdictions in which such incorporation is permitted, but only to the extent that that material is consistent with this specification.

Claims: CLAIMS What is claimed is: 1. A one-stage hydrogenation process comprising: (a) providing a hydrocarbon resin containing from 50-2000 ppm by weight of one or more halogen residues, wherein the resin has an initial softening point from 70 to 150 °C; (b) introducing the hydrocarbon resin into a reactor; (c) hydrotreating the resin with a catalyst using: (i) a pressure of not more than 2000 psi; (ii) a reaction time of at least 800 hours; (iii) a temperature from 100 to 350 °C wherein the catalysts produces at least 350 tons of polymer per ton of catalyst; and (d) recovering hydrotreated resin from the reactor wherein the resin has a final softening point greater than or equal to the initial softening point minus 8 °C. 2. The hydrogenation process of claim 1 wherein the halogen residue is not removed from the resin prior to step (b). 3. The hydrogenation process of claim 1 wherein the resin of step (a) has carbon-carbon double bonds that are hydrogenated in step (c) such that at least 1% by weight of the carbon-carbon double bonds are converted to saturated carbon-carbon bonds. 4. The hydrogenation process of claim 1-3 wherein step (c) is conducted using a pressure of not more than 1500 psi (10,342.5 kPa). 5. The hydrogenation process of claim 1-3 wherein step (c) is conducted using a pressure of not more than 1000 psi (6,895 kPa). 6. The hydrogenation process of claim 1-4 wherein step (c) is conducted using a temperature from 150 to 300°C. 7. The hydrogenation process of claim 1-4 wherein step (c) is conducted using a temperature from 160 to 270°C. 8. The hydrogenation process of claim 1-7 conducted for at least 1000 hours. 9. The hydrogenation process of claim 1-7 conducted for at least 1500 hours. 10. The hydrogenation process of claim 9 wherein the catalyst used in step (c) is supported on an acidic support. 11. The hydrogenation process of claim 10 wherein the hydrotreated resin recovered in step (d) has a final softening point less than 5°C below the initial softening point. 12. The hydrogenation process of claim 10 wherein the hydrotreated resin recovered in step (d) has a final softening point greater than or equal to the initial softening point. 13. The hydrogenation process of claim 1-12 wherein the hydrotreated resin recovered in step (d) has an aromaticity level that is not decreased by more than 5% equivalent styrene during step (c). 14. The hydrogenation process of claim 1-12 wherein the hydrotreated resin recovered in step (d) has an aromaticity level that is not decreased by more than 2% equivalent styrene during step (c). 15. The hydrogenation process of claim 1-14 wherein the color (yellowness index) is reduced by at least 40%. 16. The hydrogenation process of claim 1-15 wherein the hydrocarbon resin is catalytically polymerized. 17. The hydrogenation process of claim 1-16 wherein the hydrocarbon resin of step (a) contains from 100-1500 ppm by weight of one or more halogens. 18. A continuous, one-stage hydrogenation process according to claims 1-17 wherein the process is conducted in a continuous fashion. 19. A resin produced using the process of any of claims 1-18. 20. An article comprising the resin of claims 1-18.

Inventors: HALUSKA JERRY L, MACEDO ANNE V, HALUSKA, JERRY, L., MACEDO, ANNE, V.
Applicants: EXXONMOBIL CHEM PATENTS INC, EXXONMOBIL CHEMICAL PATENTS INC.
Application year: 2001
Main classification: C08F8
IPC codes: C08C19, C08F8