Manufacturing of rigid foam using etherified modified aromatic polyols

In a method for the preparation of a rigid polyisocyanurate foam composition wherein an excess of an aromatic polyisocyanate is reacted with a polyol component in the presence of an isocyanurate catalyst, a blowing agent, and a surfactant under basic conditions:

• the improvement for obtaining a rigid polyisocyanurate foam having improved properties which comprises:
• utilizing a polyol component comprising an etherified modified aromatic polyol, said etherified modified aromatic polyol having been prepared by:
• digesting a polyalkylene terephthatlate with a low molecular weight polyol selected from a group consisting essentially of ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, glycerol, and trimethyol propane with the ratio of about 0.5 to about 1 mole equivalents of polyalkylene terephthalate to about 1 to about 0.5 moles of low molecular weight polyol at a temperature of about 180.degree. to about 250.degree. C. to provide a digested polyol;
• reacting said digested polyol with about 0.01 to about 0.7 moles of an additional low molecular weight polyol containing about 3 to about 8 hydroxyl groups and a molecular weight from about 90 to about 350 per mole equivalent of polyalkylene terephthalate at a temperature of about 120.degree. to about 200.degree. C. from about 1 to about 4 hours to form an intermediate product;
• and
• alkoxylating in the presence of a basic alkoxylation catalyst said intermediate product with an alkoxylation component comprising from about 1 to about 4 mole equivalents of alkylene oxide per mole equivalent of said polyalkylene terephthalate, said alkylene oxide consisting of from 0 to about 4 moles of ethylene oxide and, correspondingly, from 4 to about 0 moles of propylene oxide with the temperature not exceeding about 200.degree. C.

A rigid polyurethane foam composition prepared by reacting an excess of an aromatic polyisocyanate with a polyol component in the presence of a catalyst, a blowing agent and a surfactant:

• said polyol component being composed of from 100 to about 80 wt. % of an etherified modified aromatic polyol and, correspondingly , from 0 to about 20 wt. % of a polyoxyalkylene polyol component, said etherified modified aromatic polyol having been prepared by:
• digesting a polyalkylene terephthalate with a low molecular weight polyol selected from a group consisting essentially of ethylene glycol, propylene glycoo, butylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, glycerol, and trimethyol propane with the ratio of about 0.5 to about 1 mole equivalents of polyalkylene terephthalate to about 1 to about 0.5 moles of low molecular weight polyol at a temperature of about 180.degree. to about 250.degree. C. to provide a digested polyol;
• reacting said digested polyol with about 0.01 to about 0.7 moles of an additional low molecular weight polyol containing from about 3 to about 8 hydroxyl groups and a molecular weight from about 90 to about 350 per mole equivalent of polyalkylene terephthalate at a temperature of about 120.degree. to about 200.degree. C. from about 1 to about 4 hours to form an intermediate product;
• and
• alkoxylating in the presence of a basic alkoxylation catalyst said intermediate product with an alkoxylation component comprising from about 1 to about 4 moles equivalents of alkylene oxide per mole equivalent of said polyalkylene terephthalate, said alkylene oxide consisting of from 0 to about 4 moles of ethylene oxide and, correspondingly, from 4 moles to about 0 moles of propylene oxide with the temperature not exceeding about 200.degree. C.;
• said polyoxyalkylene polyol component having been prepared by reacting an initiator having a functionality of about 3 to about 6 with an alkylene oxide component consisting of from 100 to about 80 wt. % of propylene oxide and 0 to about 20 wt. % of ethylene oxide;
• and
• said polyoxyalkylene polyol component having a hydroxyl number of about 200 to about 800.

A rigid polyisocyanurate foam composition prepared by reacting an excess of an aromatic polyisocyanate with a polyol component in the presence of an isocyanurate catalyst, a blowing agent and a surfactant under basic conditions:

• said polyol component being composed of from 100 to about 80 wt. % of an etherified modified aromatic polyol and, correspondingly, from 0 to about 20 wt. % of a polyoxyalkylene polyol component having a hydroxyl number of about 200 to 800, said etherified modified aromatic polyol having been prepared by:
• digesting a polyalkylene terephthalate with a low molecular weight polyol selected from a group consisting essentially of ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, glycerol, and trimethyol propane with the ratio of about 0.5 to about 1 mole equivalents of polyalkylene terephthalate to about 1 to about 0.5 moles of low molecular weight polyol at a temperature of about 180.degree. to about 250.degree. C. to provide a digested polyol;
• reacting said digested polyol with about 0.01 to about 0.7 moles of an additional low molecular weight polyol containing from about 3 to about 8 hydroxyl groups and a molecular weight from about 90 to about 350 per mole equivalent of polyalkylene terephthalate at a temperature of about 120.degree. to about 200.degree. C. from about 1 to about 4 hours to form an intermediate product;
• and
• alkoxylating in the presence of a basic alkoxylation catalyst said intermediate product with an alkoxylation component comprising from about 1 to about 4 mole equivalents of alkylene oxide per mole equivalent of said polyalkylene terephthalate, said alkylene oxide consisting of from 0 to about 4 moles of ethyelen oxide and, correspondingly, from 4 moles to about 0 moles of propylene oxide with the temperature not exceeding about 200.degree. C.;
• said polyoxyalkylene polyol component having been prepared by reacting an initiator having a functionality of about 3 to about 6 with an alkylene oxide component consisting of from 100 to about 80 wt. % of propylene oxide and 0 to about 20 wt. % of ethylene oxide.

A rigid polyisocyanurate foam composition prepared by reacting an excess of an aromatic polyisocyanate with a polyol component in the presence of a catalyst, a blowing agent and a surfactant:

• said polyol component being composed of from about 10% to about 50% fluorocarbon solubilizer and, correspondingly, from about 90% to about 50% of an etherified modified aromatic polyol having been prepared by:
• digesting a polyalkylene terephthalate with a low molecular weight polyol selected from a group consisting essentially of ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, glycerol, and trimethol propane with the ratio of about 0.5 to about 1 mole equivalents of polyalkylene terephthalate to about 1 to about 0.5 moles of low molecular weight polyol at a temperature of about 180.degree. to about 250.degree. C. to provide a digested polyol;
• reacting said digested polyol with about 0.01 to about 0.7 moles of an additional low molecular weight polyol containing from about 3 to about 8 hydroxyl groups and a molecular weight from about 90 to about 350 per mole equivalent of polyalkylene terephthalate at a temperature of about 120.degree. to about 200.degree. C. from about 1 to about 4 hours to form an intermediate product;
• and
• alkoxylating in the presence of a basic alkoxylation catalyst said intermediate product with an alkoxylation component comprising from about 1 to about 4 mole equivalents of alkylene oxide per mole equivalent of said polyalkylene terephthalate, said alkylene oxide consisting of from 0 to about 4 moles of ethylene oxide and, correspondingly, from 4 moles to about 0 moles of propylene oxide with the temperature not exceeding about 200.degree. C.