PROCESSING ZINC DIACRYLATE DISPERSED IN HIGH-CIS POLYBUTADIENE
The present invention provides a method and product that provides a dust-free homogeneous dispersion of zinc diacrylate in polybutadiene for use in golf balls in which a first and a second processing promoters are used in the production of the dispersion and incorporated into the dispersions, such first processing promoters including low molecular weight polyethylene, fatty acids, and zinc salts of fatty acids and such second processing promoters being metal oxides including zinc oxide, magnesium oxide, and calcium oxide.
1 . A rubber dispersion composition comprising:
from about 12 to 50 parts by weight of a polybutadiene;
from about 50 to 85 parts by weight of zinc diacrylate;
from about 0.5 to 5 parts by weight of a first processing promoter selected from the group consisting of low molecular weight polyethylene, fatty acids, zinc salts of fatty acids and mixtures thereof; and
from about 0.5 to 5 parts by weight of a second processing promoter which is a metal oxide,
all parts by weight being based on the total weight of said dispersion.
2 . The composition according to claim 1 , wherein said metal oxide is selected from the group consisting of zinc oxide, magnesium oxide, calcium oxide and mixtures thereof
3 . The composition according to claim 1 , wherein said metal oxide is zinc oxide.
4 . The composition according to claim 1 , wherein said polybutadiene is a high-cis-polybutadiene.
5 . The composition according to claim 1 , wherein said dispersion comprises from 12 to 22 parts by weight of said polybutadiene.
6 . The composition according to claim 1 , wherein said dispersion comprises 15 to 19 parts by weight of said polybutadiene.
7 . The composition according to claim 1 , wherein said dispersion comprises 70 to 85 parts by weight of zinc diacrylate based on the total weight of said dispersion.
8 . The composition according to claim 1 , wherein said dispersion comprises 75 to 85 parts by weight of zinc diacrylate based on the total weight of said dispersion.
9 . The composition according to claim 1 , wherein said first processing promoter is a low molecular weight polyethylene having a molecular weight from 750 to 2500.
10 . The composition according to claim 1 , wherein said first processing promoter is a blend of polymer olefin and polyethylene wax having a softening point around 112° C. and is present at 0.5 to 5.0 percent by weight of the total product.
11 . The composition according to claim 9 , wherein said first processing promoter is present at 2.5 to 3.5 percent by weight of the total product.
12 . The composition according to claim 1 , wherein said first processing promoter is a low molecular weight polyethylene with a softening point around 85° C.
13 . The composition according to claim 1 , wherein said first processing promoter is a low molecular weight polyethylene having a density of 1.33 g/cc and an ML(1+4)100° C. of 37.
14 . The composition according to claim 1 , wherein said first processing promoter comprises zinc salts of mainly unsaturated fatty acids.
15 . The composition according to claim 1 , wherein said first processing promoter is a blend of zinc salts of mainly saturated fatty acids having a density of 1.08 g/cc and a softening point about 100° C.
16 . The composition according to claim 1 , wherein said fatty acid is oleic acid.
17 . The composition according to claim 1 , wherein said zinc salts of fatty acids is a zinc salt of oleic acid.
18 . A process for making a rubber dispersion comprising the steps of:
mixing
i) from about 12 to 50 parts by weight of a polybutadiene;
ii) from about 50 to 85 parts by weight of zinc diacrylate;
iii) from about 0.5 to 5 parts by weight of a first processing promoter selected from the group consisting of low molecular weight polyethylene, fatty acids, zinc salts of fatty acids and mixtures thereof; and
iv) from about 0.5 to 5 parts by weight of a second processing promoter which is a metal oxide; thereby forming a mixture,
where all parts by weight being based on the total weight of said dispersion; and
extruding said mixture thereby forming an extruded mixture; and
pelletizing or slabbing said extruded mixture.
19 . The process according to claim 18 , wherein said metal oxide is selected from the group consisting of zinc oxide, magnesium oxide , calcium oxide and mixtures thereof
20 . The process according to claim 18 , wherein said metal oxide is zinc oxide.
21 . The process according to claim 18 , wherein said polybutadiene is a high-cis-polybutadiene.
22 . The process according to claim 18 , wherein said dispersion comprises from 12 to 22 parts by weight of said polybutadiene.
23 . The process according to claim 18 , wherein said dispersion comprises 15 to 19 parts by weight of said polybutadiene.
24 . The process according to claim 18 , wherein said dispersion comprises 70 to 85 parts by weight of zinc diacrylate based on the total weight of said dispersion.
25 . The process according to claim 18 , wherein said dispersion comprises 75 to 85 parts by weight of zinc diacrylate based on the total weight of said dispersion.
26 . The process according to claim 16 , wherein said first processing promoter is a low molecular weight having a molecular weight from 750 to 2500 polyethylene.