Thermoplastic polyurethane resin having broad rubbery-state region and process for producing the same

A process for producing a polyurethane resin having a broad rubbery-state region which has a number-average molecular weight of from 30,000 to 500,000 and comprises repeating units (A) represented by formula (I):

• --CONH-X-NHCOO-Y-O-- (I)
• wherein X represents the divalent residue formed by removing the isocyanate groups from an aromatic diisocyanate selected from the group consisting of p-phenylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, and 3,3'-dimethyldiphenyl 4,4-diisocyanate, and Y represents the divalent residue formed by removing the hydroxyl groups from a poly(alkylene ether) diol whose main chain is made up of the group represented by --CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.2 O-- and a group represented by --CHR.sub.1 CHR.sub.2 CHR.sub.3 CHR.sub.4 O-- where one of R.sub.1, R.sub.2, R.sub.3, and R.sub.4 is a lower alkyl group and the remaining three each is a hydrogen atom, and which has a number-average molecular weight of from 500 to 10,000, and repeating units (B) represented by formula (II):
• --CONH-X-NHCOO-Z-O-- (II)
• wherein X represents the divalent residue formed by removing the isocyanate groups from an aromatic diisocyanate selected from the group consisting of p-phenylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, and 3,3'-dimethyldiphenyl 4,4-diisocyanate, and Z represents the divalent residue formed by removing the hydroxyl groups from 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane), the repeating units (A) and (B) being bonded together in a random sequence, with the proportion of (A)/(B) being from 0.1 to 2.0,
• which comprises reacting an aromatic diisocyanate selected from the group consisting of p-phenylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, and 3,3'-dimethyldiphenyl 4,4-diisocyanate with a poly(alkylene ether) diol whose main chain is made up of the group represented by --CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.2 O-- and a group represented by --CHR.sub.1 CHR.sub.2 CHR.sub.3 CHR.sub.4 O-- where one of R.sub.1, R.sub.2, R.sub.3, and R.sub.4 is a lower alkyl group and the remaining three each is a hydrogen atom, and which has a number-average molecular weight of from 500 to 10,000 in a molar ratio (r) of (1.5-10.0):1 in an inert atmosphere either in an inert solvent or without a solvent at a temperature of from room temperature to 130.degree. C. to form a partial prepolymer composed of components represented by formula (III) and (IV):
• OCN-(-X-NHCOO-Y-O-CONH--)p-X-NCO (III)
• q.times.(OCN-X-NCO) (IV)
• wherein p and q each is a positive number, provided that (p+q+1)/p=r, X represents the divalent residue formed by removing the isocyanate groups from an aromatic diisocyanate selected from the group consisting of p-phenylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, and 3,3'-dimethyldiphenyl 4,4-diisocyanate, and Y represents the divalent residue formed by removing the hydroxyl groups from a poly(alkylene ether) diol whose main chain is made up of the group represented by --CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.2 O-- and a group represented by --CHR.sub.1 CHR.sub.2 CHR.sub.3 CHR.sub.4 O-- where one of R.sub.1, R.sub.2, R.sub.3, and R.sub.4 is a lower alkyl group and the remaining three each is a hydrogen atom, and which has a number-average molecular weight of from 500 to 10,000, and
• then adding 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane to the resulting reaction system in an amount of from 0.90 to 1.10 mol per mol of the partial prepolymer composed of the components represented by formulae (III) and (IV) to conduct a polyaddition reaction in an inert atmosphere.

A process for producing a polyurethane resin having a broad rubbery-state region which has a number-average molecular weight of from 30,000 to 500,000 and comprises repeating units (A) represented by formula (I):

• --CONH-X-NHCOO-Y-O-- (I)
• wherein X represents the divalent residue formed by removing the isocyanate groups from an aromatic diisocyanate selected from the group consisting of p-phenylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, and 3,3'-dimethyldiphenyl 4,4-diisocyanate, and Y represents the divalent residue formed by removing the hydroxyl groups from a poly(alkylene ether) diol whose main chain is made up of the group represented by --CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.2 O-- and a group represented by --CHR.sub.1 CHR.sub.2 CHR.sub.3 CHR.sub.4 O-- where one of R.sub.1, R.sub.2, R.sub.3, and R.sub.4 is a lower alkyl group and the remaining three each is a hydrogen atom, and which has a number-average molecular weight of from 500 to 10,000, and repeating units (B) represented by formula (II):
• --CONH-X-NHCOO-Z-O-- (II)
• wherein X represents the divalent residue formed by removing the isocyanate groups from an aromatic diisocyanate selected from the group consisting of p-phenylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, and 3,3'-dimethyldiphenyl 4,4-diisocyanate, and Z represents the divalent residue formed by removing the hydroxyl groups from 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane), the repeating units (A) and (B) being bonded together in a random sequence, with the proportion of (A)/(B) being from 0.1 to 2.0,
• which comprises polyaddition reacting (a) an aromatic diisocyanate selected from the group consisting of p-phenylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, and 3,3'-dimethyldiphenyl 4,4-diisocyanate with (b) a poly(alkylene ether) diol whose main chain is made up of the group represented by --CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.2 O-- and a group represented by --CHR.sub.1 CHR.sub.2 CHR.sub.3 CHR.sub.4 O-- where one of R.sub.1, R.sub.2, R.sub.3, and R.sub.4 is a lower alkyl group and the remaining three each is a hydrogen atom, and which has a number-average molecular weight of from 500 to 10,000 and (c) 3,9-bis(1,1-dimethyl-.sub.2 -hydroxyethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane in an (a)/{(b)+(c)} molar ratio of from 0.90 to 1.10 in an inert atmosphere either at a temperature of from room temperature to 130.degree. C. in an inert solvent or at a temperature of from 180.degree. to 230.degree. C. without a solvent.