Method of preparing a bodied siloxane resin including M, Q, and T-propyl units and capped with additional M units

1. A method of preparing a post-capped bodied siloxane resin, said method comprising:

capping a bodied siloxane resin comprising M, Q, and T-propyl units with a silicon-containing M group capping agent in a reaction vessel to form the post-capped bodied siloxane resin.

2. The method of claim 1 wherein the step of capping the bodied siloxane resin with the silicon-containing M group capping agent is performed in the presence of an organic solvent, the method further comprising:

conducting a solvent-exchange between the organic solvent and an alternative carrier solvent.

3. The method of claim 2 wherein the organic solvent comprises one or more hydrocarbons.

4. The method of claim 2 wherein the alternative carrier solvent comprises isododecane, 2-butyloctanol, isohexadecane, C 12-15 alkyl benzoate, castor oil, hydrogenated palm oil, glycerin, isopropyl palmitate, cyclic siloxane, short-chain siloxane, or aliphatic hydrocarbon.

5. The method of claim 1 wherein the step of capping the bodied siloxane resin comprises heating the bodied siloxane resin and silicon-containing M group capping agent to a temperature ranging from 25 to 60° C.

6. The method of claim 5 wherein the step of heating the bodied siloxane resin and the silicon-containing M group capping agent is conducted for a duration ranging from 30 to 600 minutes.

7. The method of claim 1 further comprising removing residual silicon-containing M group capping agent from the reaction vessel after the step of capping the bodied siloxane resin.

8. The method of claim 1 further comprising distilling residual silicon-containing M group capping agent from the reaction vessel.

9. The method of claim 1 wherein the bodied siloxane resin capped with the silicon-containing M group capping agent comprises the units:

(R 1 3 SiO 1/2 ) a ;

(R 2 2 SiO 2/2 ) b ;

(R 3 SiO 3/2 ) c ;

(SiO 4/2 ) d , wherein:

each R 1 , R 2 , and R 3 is independently selected from a substituted or unsubstituted carbon-containing group comprising from 1 to 10 carbon atoms, an amino group, and a sulfido group, with the proviso that at least 0.40 mole of the R 3 groups per mole of silicon in the R 3 SiO 3/2 units are propyl groups, and

a+b+c+d=1.

10. The method of claim 9 wherein a ranges from 0.05 to 0.50, b ranges from 0 to 0.30, c is greater than 0, and d ranges from 0.05 to 0.60.

11. The method of claim 1 wherein the bodied siloxane resin capped with the silicon-containing M group capping agent has an initial molecular weight (M wi ) and an aged molecular weight (M wa ) after aging the bodied siloxane resin capped with the silicon-containing M group capping agent at 110° C. for 70 hours, wherein the M wa increases 100% or less from the M wi .

12. The method of claim 1 wherein said M wa increases 50% or less from said M wi .

13. The method of claim 1 wherein the bodied siloxane resin capped with the silicon-containing M group capping agent contains less silanol groups than the bodied siloxane resin before being capped with the silicon-containing M group capping agent.

14. The method of claim 1 wherein the bodied siloxane resin capped with the silicon-containing M group capping agent comprises from 0.02 to 0.20 moles of silanol groups per mole of silicon.

15. The method of claim 1 wherein the bodied siloxane resin is selected from a group including:

((CH 3 ) 3 SiO 1/2 ) a (CH 3 CH 2 CH 2 SiO 3/2 ) c (SiO 4/2 ) d ;

((CH 3 ) 3 SiO 1/2 ) a ((CH 3 ) 2 SiO 2/2 ) b )(CH 3 CH 2 CH 2 SiO 3/2 ) c (SiO 4/2 ) d ;

((CH 3 ) 3 SiO 1/2 ) a (CH 3 ) 2 SiO 2/2 ) b ((CH 3 )(C 6 H 5 )SiO 2/2 ) b′ (CH 3 CH 2 CH 2 SiO 3/2 ) c (SiO 4/2 ) d ;

((CH 3 ) 3 SiO 1/2 ) a ((CH 3 ) 2 SiO 2/2 ) b (CH 3 CH 2 CH 2 SiO 3/2 ) c (C 6 H 5 SiO 3/2 ) c (SiO 4/2 ) d ;

((CH 3 ) 3 SiO 1/2 ) a ((CH 3 ) 2 SiO 2/2 ) b ((CH 3 )(C 6 H 5 )SiO 2/2 ) b′ (CH 3 CH 2 CH 2 SiO 3/2 ) c (C 6 H 5 SiO 3/2 ) c (SiO 4/2 ) d , and

wherein a ranges from 0.05 to 0.5, the sum of b+b′ ranges from 0 to 0.3, c ranges from 0.05 to 0.65, and d ranges from 0.05 to 0.6.

16. The method of claim 1 wherein the silicon-containing M group capping agent is represented by the following general formula:

wherein:

Z is Cl, an alkoxy group containing from 1 to 10 carbon atoms, or a hydrocarbyl group containing from 1 to 10 carbon atoms,

each R 4 , R 5 , and R 6 is independently hydrocarbyl groups containing from 1 to 10 carbon atoms,

X is O or NH, and

y ranges from 0 to 10.

17. The method of claim 1 wherein the silicon-containing M group capping agent comprises trimethylchlorosilane, trimethylalkoxysilane, hexamethyldisiloxane, or hexamethyldisilazane.