Hot melt adhesive compositions comprising polyolefin and dac-b resin

Claim 2

A hot melt adhesive composition comprising a mixture of from 65 to 75 parts by weight of polyethylene having a density of 0.90 to 0.92, ring and ball softening point of 105* to 107*C. and 25 to 35 percent of a light-color, high softening point hydrocarbon resin having a ring and ball softening point of 125* to 135* C. and having excellent thermal stability prepared by polymerizing DAC-B using aluminum chloride as a catalyst in a two-stage reaction system wherein the polymerization is conducted at a temperature of about 50* to 100* C. in the first stage for about 6-10 hours and subsequently polymerized in the second stage at a temperature of about 125* C. to 150* C. for about 6-10 hours to obtain a solution containing a high softening point crude resin in good yields, removing the chlorides from the resin solution by methanol extraction or high temperature lime treatment followed by low pressure hydrogenation at hydrogen pressure of 100-1,000 psig. and/or alumina treatment, followed by high pressure-high temperature hydrogenation at hydrogen pressures of 3,000-6,000 psig. and temperature greater than 300* C. to remove color and reduce unsaturation and thereafter stripping the resin solution to obtain low color, color stable, high softening point hydrocarbon resin in good yields.

Claim 3

A hot melt adhesive composition according to claim 3 in which the melt viscosity range is 1,500 to 4,500 cp at 177* C.

Claim 4

A hot melt adhesive composition according to claim 3 which contains 0.10 to 2.0 percent of antioxidants.

Claim 5

A hot melt adhesive composition having improved thermal and color stability consisting essentially of a mixture of from 50 to 90 parts by weight of a poly-alpha-olefin component and 10 to 50 percent by weight of a light-color, high softening point hydrocarbon resin having a ring and ball softening point of 120* to 155* C. prepared by polymerizing DAC-B using aluminum chloride as a catalyst in a two-stage reaction system wherein the polymerization is conducted at a temperature of about 50* to 100* C. in the first stage for about 6-10 hours and subsequently polymerized in the second stage at a temperature of about 125* to 150* C. for about 6- 10 hours to obtain a solution containing a high softening point crude resin in good yields, removing the chlorides from the resin solution by methanol extraction or high temperature lime treatment followed by low pressure hydrogenation at hydrogen pressure of 100-1000 psig. and/or alumina treatment, followed by high pressure-high temperature hydrogenation at hydrogen pressures of 3,000-6,000 psig. and temperature greater than 300* C. to remove color and reduce unsaturation and thereafter stripping the resin solution to obtain low color, color stable, high softening point hydrocarbon resin in good yields, said mixture containing 0.10 to 2.0 percent by weight of antioxidants. 190*

Claim 6

A hot melt adhesive composition according to claim 6 wherein the poly-alpha-olefin component is polyethylene which has a viscosity in the range of 400 cp at 125* C. to 500,000 cp at 190* C.

Claim 7

A hot melt adhesive composition according to claim 7 wherein said antioxidants are dilauryl 3,3''-thiodipropionate and lauryl stearyl thiodipropionate.

Claim 8

A hot melt adhesive composition according to claim 7 wherein said antioxidants are lauryl stearyl thiodipropionate and 2,2''-methylene bis (4-methyl-6-t-butyl phenol).