Semi-rigid polyurethane foam used in packaging

Claim 2

A semi-rigid polyurethane foam prepared from a reaction mixture having an over-all index from about 30 to about 60, which mixture comprises: a. a polyether polyol characterized by (1) a molecular weight of at least 4,000, (2) a polyhydroxy alcohol nucleus having a functionability of 2-4, (3) polyoxyalkylene chain segments attached to said nucleus and (4) a ratio of primary to secondary hydroxy groups ranging from about 1:1 to about 6:1. b. a polymeric polyisocyanate, c. water in a proportion of about 12-28 parts per every 100 parts by weight of total polyol in said mixture, d. a halogenated hydrocarbon foaming agent in a proportion of about 30-60 parts per every 100 parts by weight of total polyol in said mixture, e. an amine catalyst, and f. a non-hydrolyzable silicon-based surfactant in a proportion of about 1.5-3.2 parts per every 100 parts by weight of total polyol in said mixture.

Claim 3

The polyurethane foam of claim 1 wherein said polyether polyol is a triol having a molecular weight of about 4,500-7,500 and a ratio of primary to secondary hydroxyl groups ranging from about 1.5:1 to about 5:1.

Claim 4

The polyurethane foam of claim 2 wherein said polymeric polyisocyanate is polymethylene polyphenylisocyanate having an average NCO functionability of about 2.1-3.5.

Claim 5

The polyurethane foam of claim 3 wherein a. said polyether polyol is an oxypropylated then oxyethylated aliphatic triol having a ratio of primary to secondary hydroxyl groups from about 2:1 to about 4.5:1, b. said amine catalyst is a tertiary amine, and c. said halogenated hydrocarbon foaming agent is trichloromonofluoromethane.

Claim 6

The polyurethane foam of claim 4 wherein per every 100 parts by weight of total polyol in said mixture, there are employed: a. about 14-24 parts of said water, b. about 38-52 parts of said trichloromonofluoromethane, and c. about 1.8-3.0 parts of said silicon-based surfactant.

Claim 7

The polyurethane foam of claim 5 wherein said index ranges from about 35 to about 55 and said polymethylene polyphenylisocyanate has an average NCO functionability of about 2.3-3.0.

Claim 8

The polyurethane foam of claim 6 wherein said polymethylene polyphenylisocyanate is employed in the form of an isocyanate-terminated prepolymer thereof with a polyol having 2-8 hydroxy groups, said prepolymer having a ratio of NCO:OH groups ranging from about 10:1 to about 100:1.

Claim 9

A polyurethane foam as claimed in claim 7 which is prepared from a reaction mixture having an index of about 42-52 and comprises a. a polyether triol which is the product of condensing glycerin first with about 85-100 moles of propylene oxide and then with about 10-15 moles of ethylene oxide, b. an isocyanate-terminated prepolymer having a ratio of NCO:OH groups from about 20:1 to about 90:1 which is the product of reacting (1) polymethylene polyphenylisocyanate having an average NCO functionability of about 2.3-3.0 with (2) a polyether polyol having an average hydroxyl number of about 300-450 which is the product of condensing 4,4,4-trichloro-1,2-epoxybutane with a mixture of dextrose and ethylene glycol, c. water in a proportion of about 16-22 parts per every 100 parts by weight of total polyol in said mixture, d. trichloromonofluoromethane in a proportion of about 38-52 parts per every 100 parts of total polyol in said mixture, e. a catalytic proportion of a tertiary amine catalyst, and f. a non-hydrolyzable silicon-based surfactant in a proportion of about 1.8-3.0 parts per every 100 parts by weight by total polyol in said mixture.

Claim 10

A process wherein the polyurethane foam of claim 1 is generated on-site by means of a portable foaming apparatus.

Claim 11

A process wherein the polyurethane foam of claim 4 is generated on-site by means of a portable foaming apparatus.

Claim 12

A process wherein the polyurethane foam of claim 7 is generated on-site by means of a portable foaming apparatus.

Claim 13

A process wherein the polyurethane foam of claim 8 is generated on-site by means of a portable foaming apparatus.

Claim 14

In a method for packaging fragile articles with a cellular, shock-absorbing material, the improvement of using as said cellular material the polyurethane foam of claim 1.

Claim 15

In a method for packaging fragile articles with a cellular, shock-absorbing material, the improvement of using as said material the polyurethane foam of claim 8.