Processes for making low volatile tackifier compositions

1. A process for making a tackifier composition, said process comprising the following steps performed in the following order:

(a) polymerization of one or more monomers to form at least one partially or fully hydrogenated thermoplastic hydrocarbon resin;

(b) removing at least a portion of volatile organic compounds from the at least one thermoplastic hydrocarbon resin; and

(c) adding an antioxidant composition to said at least one thermoplastic hydrocarbon resin;

wherein the antioxidant composition comprises at least one primary antioxidant, at least one secondary antioxidant, and at least one hindered amine light stabilizer (HALS);

wherein said primary antioxidant is a hindered phenolic antioxidant or a secondary arylamine, and wherein said primary antioxidant is present in an amount of about 0.1% to about 1% based on the weight of the thermoplastic hydrocarbon resin;

wherein said secondary antioxidant is an organo-phosphite or a hydroxyl-amine, and wherein said secondary antioxidant is present in an amount of about 0.1% to about 1% based on the weight of said thermoplastic hydrocarbon resin;

wherein when said primary antioxidant is a hindered phenolic antioxidant, said secondary antioxidant is a hydroxyl-amine;

wherein when said secondary antioxidant is an organo-phosphite, then said primary antioxidant is a secondary arylamine;

wherein the antioxidant composition is added to the at least one thermoplastic resin both before and after step (b) to produce the tackifier composition;

wherein the levels of individual volatile organic compound in the tackifier composition are less than about 0.5 ppm as measured by GC/MS headspace analysis; and

wherein the amount of said HALS ranges from about 0.05% to about 0.5% by weight based on the weight of said at least one thermoplastic hydrocarbon resin.

2. The process according to claim 1 , wherein said primary antioxidant is the sterically hindered phenol and is selected from one or more of the group consisting of (CI)-(CXIX):

3. The process according to claim 1 , wherein said primary antioxidant is the secondary arylamine.

4. The process according to claim 1 , wherein said secondary antioxidant is the organo-phosphite and is selected from the group consisting of: 2,2′,T-Nitrilo[triethyl-[3,3,5,5-tetra-tert.-butyl-1,1-biphenyl-2,2-diyl] phosphite (CAS 80410-33-9); Bis(2,4-di-tert.-butyl-6-methylphenyl)-ethyl-phosphite (CAS 145650-60-8); Tris(2,4-di-tert.butylphenyl) phosphite (CAS 31570-04-4); Tetrakis(2,4-di-tert-butylphenyl)[1,1-biphenyl]-4,4′-diylbisphosphonite (CAS 119345-01-6); and Tri-(nonylphenol)-phosphite.

5. The process according to claim 1 , wherein said HALS is at least one selected from the group consisting of: (AII)-(AX):

6. The process according to claim 1 , wherein said volatile organic compounds are removed from said thermoplastic hydrocarbon resin by at least one process selected from the group consisting of: membrane separation, selective precipitation, selective polymerization conditions, evaporation and distillation, and preparative gel permeation chromatography.

7. The process according to claim 6 wherein said evaporation and distillation comprises steam stripping.

8. The process according to claim 7 wherein said steam stripping is conducted in a counter current contacting device.

9. The process according to claim 8 , wherein said contacting device is operated under vacuum at about 10 mbar to about 1000 mbar.

10. The process according to claim 8 , wherein said contacting device is operated at a temperature of about 180° C. to about 280° C.

11. The process according to claim 6 , wherein a rotary film evaporator is utilized to remove the volatile organic compounds from said thermoplastic hydrocarbon resin.

12. The process according to claim 1 , wherein said primary antioxidant is pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), wherein said HALS is bis(2,2,6,6,-tetramethyl-4-piperidyl) sebacate, and wherein said thermoplastic hydrocarbon resin is C9 thermoplastic resin.

13. The process according to claim 1 , wherein said thermoplastic hydrocarbon resin is C9 thermoplastic resin.