Sulfur-containing oligomers and high index polyurethanes prepared therefrom

• US 20070142605A1
• Filed: 12/16/2005
• Published: 06/21/2007
• Est. Priority Date: 12/16/2005
• Status: Active Grant

• Current Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Original Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Inventors: Bojkova, Nina, Smith, Robert, McDonald, William, Herold, Robert, Graham, Marvin
• Granted Patent: US 8,017,720 B2
• Time in Patent Office: Days
• US Class Current: 528/44
• CPC Class Codes: C08G 18/10 Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
• CPC Class Codes: C08G 18/1816 having carbocyclic groups
• CPC Class Codes: C08G 18/3876 containing mercapto groups
• CPC Class Codes: C08G 18/52 Polythioethers
• CPC Class Codes: C08G 18/758 containing two or more cycloaliphatic rings

Abstract

The present invention provides polythiol oligomer formed by the reaction of at least two or more different dienes and at least one or more dithiol wherein stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0:1.0; and wherein said two or more different dienes comprise (a) at least one non-cyclic diene and at least one cyclic diene; or (b) at least one aromatic ring-containing diene and at least one non-aromatic cyclic diene; or (c) at least one non-aromatic monocyclic diene and at least one non-aromatic polycyclic diene; Sulfur-containing polyurethane of the present invention can be prepared by combining polyisocyanate, polyisothiocyanate, or mixture thereof; the polythiol oligomer described above; and active hydrogen-containing material.

Claims

1. Polythiol oligomer formed by the reaction of two or more different dienes and one or more dithiol wherein stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0:

1.0, and wherein said two or more different dienes comprise

(a) at least one non-cyclic diene and at least one cyclic diene;

or

(b) at least one aromatic ring-containing diene and at least one non-aromatic cyclic diene;

or

(c) at least one non-aromatic monocyclic diene and at least one non-aromatic polycyclic diene.

2. The polythiol oligomer of claim 1(a) wherein said cyclic diene is selected from non-aromatic monocyclic dienes, non-aromatic polycyclic dienes, aromatic ring-containing dienes, and mixtures thereof.

3. The polythiol oligomer of claim 1(b) wherein said non-aromatic cyclic diene is selected from non-aromatic monocyclic dienes, non-aromatic polycyclic dienes, and mixtures thereof.

4. The polythiol oligomer of claim 1 wherein said stoichiometric ratio is from 1.1:

1.0 to 1.5;

1.0.

5. The polythiol oligomer of claim 1 further comprising trifunctional or higher-functional polythiol.

51. The polythiol oligomer of claim 1 wherein said dithiol is chosen from aliphatic dithiols, cycloaliphatic dithiols, aromatic dithiols, dithiols having heterocyclic group, polymeric dithiols, dithiols containing ether linkages, dithiols containing one or more sulfide linkages and/or disulfide linkages, or combinations thereof.

6. A sulfur-containing polyurethane comprising the reaction product of polyisocyanate, polyisothiocyanate, or mixture thereof;

polythiol oligomer formed by the reaction of two or more different dienes and one or more dithiol, wherein stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0;

1.0; and

active hydrogen-containing material including at least one material selected from trifunctional or higher-functional polyol, trifunctional or higher-functional polythiol, trifunctional or higher-functional material containing both hydroxyl and SH groups, or mixtures thereof.

7. The sulfur-containing polyurethane of claim 6 wherein said two or more different dienes comprises at least one non-cyclic diene and at least one cyclic diene.

8. The sulfur-containing polyurethane of claim 7 wherein said cyclic diene is selected from non-aromatic monocyclic diene, non-aromatic polycyclic diene, aromatic ring-containing diene, and mixtures thereof.

9. The sulfur-containing polyurethane of claim 6 wherein said two or more different dienes comprises at least one aromatic ring-containing diene and at least one non-aromatic cyclic diene.

10. The sulfur-containing polyurethane of claim 9 wherein said non-aromatic cyclic diene is selected from non-aromatic monocyclic diene, non-aromatic polycyclic diene, and mixtures thereof.

11. The sulfur-containing polyurethane of claim 6 wherein said two or more different dienes comprises at least one non-aromatic monocyclic diene and at least one non-aromatic polycyclic diene.

12. The sulfur-containing polyurethane of claim 6 wherein said stoichiometric ratio is from 1.1:

1.0 to 1.5;

1.0.

13. The sulfur-containing polyurethane of claim 6 wherein said polythiol oligomer further comprises trifunctional or higher-functional polythiol.

14. The sulfur-containing polyurethane of claim 6 wherein said active hydrogen-containing material further comprises at least one material selected from diol, dithiol, difunctional material containing both hydroxyl and SH groups, or mixtures thereof.

15. The sulfur-containing polyurethane of claim 14 wherein said dithiol includes dithiol oligomer.

16. The sulfur-containing polyurethane of claim 6 having a refractive index of at least 1.55 and an Abbe number of at least 30, when polymerized.

17. The sulfur-containing polyurethane of claim 6 having a refractive index of at least 1.55 and an Abbe number of at least 35, when polymerized.

18. The sulfur-containing polyurethane of claim 6 having a refractive index of at least 1.57, and an Abbe number of at least 30, when polymerized.

19. The sulfur-containing polyurethane of claim 6 having a refractive index of at least 1.57 and an Abbe number of at least 35, when polymerized.

20. The sulfur-containing polyurethane of claim 6 having a refractive index of at least 1.59 and an Abbe number of at least 30, when polymerized.

21. The sulfur-containing polyurethane of claim 6 prepared by:

(a) reacting polyisocyanate, polyisothiocyanate, or mixture thereof;

polythiol oligomer formed by the reaction of two or more different dienes and one or more dithiol, wherein stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0;

1.0; and

active hydrogen-containing material including at least one material selected from trifunctional or higher-functional polyol, trifunctional or higher-functional polythiol, trifunctional or higher-functional material containing both hydroxyl and SH groups, or mixtures thereof, to form sulfur-containing polyurethane prepolymer; and

(b) reacting said sulfur-containing polyurethane prepolymer with active hydrogen-containing material including at least one material selected from polyol, polythiol, polyfunctional material containing both hydroxyl and SH groups, or mixtures thereof.

22. The sulfur-containing polyurethane of claim 21 wherein said active hydrogen-containing material of (a) further comprises at least one material selected from diol, dithiol, difunctional material containing both hydroxyl and SH groups, or mixtures thereof.

23. The sulfur-containing polyurethane of claim 22 wherein said dithiol includes dithiol oligomer.

24. The sulfur-containing polyurethane of claim 21 wherein said polythiol of (b) includes dithiol oligomer.

25. The sulfur-containing polyurethane of claim 6 prepared by:

(a) reacting polyisocyanate, polyisothiocyanate, or mixture thereof; and

polythiol oligomer formed by the reaction of two or more different dienes and one or more dithiol, wherein stoichiometric ratio of sum of number of equivalents of all polythiols to sum of number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0;

1.0;

to form sulfur-containing polyurethane prepolymer; and

(b) reacting said sulfur-containing polyurethane prepolymer with active hydrogen-containing material including at least one material selected from trifunctional or higher-functional polyol, trifunctional or higher-functional polythiol, trifunctional or higher-functional material containing both hydroxyl and SH groups, or mixtures thereof.

26. The sulfur-containing polyurethane of claim 25 wherein (a) further comprises active hydrogen-containing material including at least one material selected from polyol, polythiol, polyfunctional material containing both hydroxyl and SH groups, or mixtures thereof.

27. The sulfur-containing polyurethane of claim 26 wherein said polythiol includes dithiol oligomer.

28. The sulfur-containing polyurethane of claim 25 wherein said active hydrogen-containing material of (b) further comprises at least one material selected from diol, dithiol, difunctional material containing both hydroxyl and SH groups, or mixtures thereof.

29. The sulfur-containing polyurethane of claim 28 wherein said dithiol includes dithiol oligomer.

30. The sulfur-containing polyurethane of claim 6 prepared by reacting polyisocyanate, polyisothiocyanate, or mixture thereof;

polythiol oligomer formed by the reaction of two or more different dienes and one or more dithiol, wherein stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0;

1.0; and

active hydrogen-containing material including at least one material selected from trifunctional or higher-functional polyol, trifunctional or higher-functional polythiol, trifunctional or higher-functional material containing both hydroxyl and SH groups, or mixtures thereof, in a one-pot process.

31. The sulfur-containing polyurethane of claim 30 wherein said active hydrogen-containing material further comprises at least one material selected from diol, dithiol, difunctional material containing both hydroxyl and SH groups, or mixtures thereof.

32. The sulfur-containing polyurethane of claim 31 wherein said dithiol includes dithiol oligomer.

33. The sulfur-containing polyurethane of claim 6 wherein said polyisocyanate is chosen from aliphatic polyisocyanates, cycloalophatic polyisocyanates, aromatic polyisocyanates, cyclic dimers and cyclic trimers thereof, and mixtures thereof.

34. The sulfur-containing polyurethane of claim 33 wherein said polyisocyanate is chosen from 1,3-bis(1-isocyanato-1-methylethyl)benzene;

3-isocyanato-methyl-3,5,5-trimethyl cyclohexyl isocyanate;

4,4′

-methylene bis(cyclohexyl isocyanate);

meta-xylylene diisocyanate;

or mixtures thereof.

35. The sulfur-containing polyurethane of claim 21 wherein said polyisocyanate, polyisothiocyanate, or mixture thereof used to prepare said sulfur-containing polyurethane prepolymer is polyisocyanate.

36. The sulfur-containing polyurethane of claim 35 wherein the amount of said polyisocyanate, the amount of said polythiol oligomer, and the amount of said active hydrogen-containing are selected such that the equivalent ratio of (NCO):

(SH+OH) is from 2.0;

1.0 to 5.5;

1.0.

37. The sulfur-containing polyurethane of claim 21 wherein the amount of said sulfur-containing polyurethane prepolymer and the amount of said active hydrogen-containing of (b) to form sulfur-containing polyurethane are selected such that the equivalent ratio of (OH+SH):

(NCO) is from 1.1;

1.0 to 0.85;

1.0

38. The sulfur-containing polyurethane of claim 25 wherein said polyisocyanate, polyisothiocyanate, or mixture thereof used to prepare said sulfur-containing polyurethane prepolymer is polyisocyanate.

39. The sulfur-containing polyurethane of claim 38 wherein the amount of said polyisocyanate, and the amount of said polythiol oligomer are selected such that the equivalent ratio of (NCO):

(SH) is from 2.0;

1.0 to 5.5;

1.0.

40. The sulfur-containing polyurethane of claim 25 wherein the amount of said sulfur-containing polyurethane prepolymer and the amount of said active hydrogen-containing material of (b) to form sulfur-containing polyurethane are selected such that the equivalent ratio of (OH+SH):

(NCO) is from 1.1;

1.0 to 0.85;

1.0

50. The sulfur-containing polyurethane of claim 6 wherein said trifunctional or higher functional polythiol includes at least one material selected from pentaerythritol tetrakis(2-mercaptoacetate), pentaerythritol tetrakis(3-mercaptopropionate), and materials represented by the following structural formulas:

wherein n is an integer from 1 to 20

wherein n is an integer from 1 to 20.

wherein n is an integer from 1 to 20.

52. The sulfur-containing polyurethane of claim 6 wherein said dithiol is chosen from aliphatic dithiols, cycloaliphatic dithiols, aromatic dithiols, dithiols having heterocyclic group, polymeric dithiols, dithiols containing ether linkages, dithiols containing one or more sulfide linkages and/or disulfide linkages, or combinations thereof.

53. The sulfur-containing polyurethane of claim 6 wherein said polythiol is chosen from aliphatic polythiols, cycloaliphatic polythiols, aromatic polythiols, polythiols having hetrocyclic group, polymeric polythiols, polythiols containing ether linkages, polythiols containing one or more sulfide linkages and/or disulfide linkages, or combinations thereof.

41. A method of preparing sulfur-containing polyurethane comprising:

(a) reacting polyisocyanate, polyisothiocyanate, or mixture thereof;

polythiol oligomer formed by the reaction of two or more different dienes and one or more dithiol, wherein stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0;

1.0; and

active hydrogen-containing material including at least one material selected from trifunctional or higher-functional polyol, trifunctional or higher-functional polythiol, trifunctional or higher-functional material containing both hydroxyl and SH groups, or mixtures thereof, to form sulfur-containing polyurethane prepolymer; and

(b) reacting said sulfur-containing polyurethane prepolymer with active hydrogen-containing material including at least one material selected from polyol, polythiol, polyfunctional material containing both hydroxyl and SH groups, or mixtures thereof, to form said sulfur-containing polyurethane.

42. Method of claim 41 wherein said active hydrogen-containing material of (a) further comprises at least one material selected from diol, dithiol, difunctional material containing both hydroxyl and SH groups, or mixtures thereof.

43. Method of claim 41 wherein said polythiol of (b) includes dithiol oligomer.

44. Method of preparing sulfur-containing polyurethane comprising:

(a) reacting polyisocyanate, polyisothiocyanate, or mixture thereof; and

polythiol oligomer formed by the reaction of two or more different dienes and one or more dithiol, wherein stoichiometric ratio of sum of number of equivalents of all polythiols to sum of number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0;

1.0;

to form sulfur-containing polyurethane prepolymer; and

(b) reacting said sulfur-containing polyurethane prepolymer with active hydrogen-containing material including at least one material selected from trifunctional or higher-functional polyol, trifunctional or higher-functional polythiol, trifunctional or higher-functional material containing both hydroxyl and SH groups, or mixtures thereof, to form said sulfur-containing polyurethane.

45. Method of claim 44 wherein a) further comprises active hydrogen-containing material including at least one material selected from polyol, polythiol, polyfunctional material containing both hydroxyl and SH groups, or mixtures thereof.

46. Method of claim 44 wherein said active hydrogen-containing material of (b) further comprises at least one material selected from diol, dithiol, difunctional material containing both hydroxyl and SH groups, or mixtures thereof.

47. A method of preparing sulfur-containing polyurethane comprising reacting:

(a) polyisocyanate, polyisothiocyanate, or mixture thereof;

(b) polythiol oligomer formed by the reaction of two or more different dienes and one or more dithiol, wherein stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0;

1.0; and

(c) active hydrogen-containing material including at least one material selected from trifunctional or higher-functional polyol, trifunctional or higher-functional polythiol, trifunctional or higher functional material containing both hydroxyl and SH groups;

in a one-pot process.

48. Method of claim 47 wherein (c) further comprises at least one material chosen from diol, dithiol, difunctional material containing both hydroxyl and SH groups, or mixtures thereof.

49. Method of claim 48 wherein said dithiol includes dithiol oligomer.

54. An optical article comprising a sulfur-containing polyurethane, wherein said sulfur-containing polyurethane comprises the reaction product of polyisocyanate, polyisothiocyanate, or mixture thereof;

polythiol oligomer formed by the reaction of two or more different dienes and one or more dithiol, wherein stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0;

1.0; and

active hydrogen-containing material including at least one material selected from trifunctional or higher-functional polyol, trifunctional or higher-functional polythiol, trifunctional or higher-functional material containing both hydroxyl and SH groups, or mixtures thereof.

55. An ophthalmic lens comprising a sulfur-containing polyurethane, wherein said sulfur-containing polyurethane comprises the reaction product of polyisocyanate, polyisothiocyanate, or mixture thereof;

polythiol oligomer formed by the reaction of two or more different dienes and one or more dithiol, wherein stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0;

1.0; and

active hydrogen-containing material including at least one material selected from trifunctional or higher-functional polyol, trifunctional or higher-functional polythiol, trifunctional or higher-functional material containing both hydroxyl and SH groups, or mixtures thereof.

56. A photochromic article comprising a sulfur-containing polyurethane, wherein said sulfur-containing polyurethane comprises the reaction product of polyisocyanate, polyisothiocyanate, or mixture thereof;

polythiol oligomer formed by the reaction of two or more different dienes and one or more dithiol, wherein stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0;

1.0; and

active hydrogen-containing material including at least one material selected from trifunctional or higher-functional polyol, trifunctional or higher-functional polythiol, trifunctional or higher-functional material containing both hydroxyl and SH groups, or mixtures thereof.

57. The photochromic article of claim 56 wherein it comprises a polymerized substrate, and at least a photochromic amount of a photochromic substance.

58. The photochromic article of claim 57 wherein said photochromic substance is imbibed into said substrate.

59. The photochromic article of claim 57 wherein said substrate is coated with a coating composition comprising at least a photochromic amount of a photochromic substance.

60. The photochromic article of claim 57 wherein said photochromic substance comprises at least one naphthopyran.

61. The photochromic article of claim 57 wherein said photochromic substance is chosen from spiro(indoline)naphthoxazines, spiro(indoline)benzoxazines, benzopyrans, naphthopyrans, organo-metal dithizonates, fulgides and fulgimides, and mixtures thereof.

62. A photochromic article comprising a sulfur-containing polyurethane, wherein said sulfur-containing polyurethane comprises the reaction product of polyisocyanate, polyisothiocyanate, or mixture thereof, polythiol oligomer formed by the reaction of two or more different dienes and one or more dithiol, wherein stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0:

1.0, and active hydrogen-containing material including at least one material selected from trifunctional or higher-functional polyol, trifunctional or higher-functional polythiol, trifunctional or higher-functional material containing both hydroxyl and SH groups, or mixtures thereof;

a polymerized substrate;

a photochromic amount of a photochromic material wherein said photochromic material is imbibed into said substrate

63. A photochromic article comprising a sulfur-containing polyurethane, wherein said sulfur-containing polyurethane comprises the reaction product of polyisocyanate, polyisothiocyanate, or mixture thereof;

polythiol oligomer formed by the reaction of two or more different dienes and one or more dithiol, wherein stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0;

1.0; and

active hydrogen-containing material including at least one material selected from trifunctional or higher-functional polyol, trifunctional or higher-functional polythiol, trifunctional or higher-functional material containing both hydroxyl and SH groups, or mixtures thereof;

a polymerized substrate, wherein said substrate is coated with a coating composition comprising at least a photochromic amount of a photochromic material.

64. A sulfur-containing polyurethane comprising the reaction product of polyisocyanate, polyisothiocyanate, or mixture thereof;

polythiol oligomer formed by the reaction of two or more different dienes and one or more dithiol, wherein stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0;

1.0; and

active hydrogen-containing material including at least one material selected from trifunctional or higher-functional polyol, trifunctional or higher-functional polythiol, trifunctional or higher-functional material containing both hydroxyl and SH groups, or mixtures thereof;

wherein said sulfur-containing polyurethane contains di-sulfide linkage.

65. The sulfur-containing polyurethane of claim 64 prepared by

(a) reacting polyisocyanate, polyisothiocyanate, or mixture thereof;

polythiol oligomer formed by the reaction of two or more different dienes and one or more dithiol, wherein stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0;

1.0; and

active hydrogen-containing material including at least one material selected from trifunctional or higher-functional polyol, trifunctional or higher-functional polythiol, trifunctional or higher-functional material containing both hydroxyl and SH groups, or mixtures thereof, to form sulfur-containing polyurethane prepolymer; and

(b) reacting said sulfur-containing polyurethane prepolymer with active hydrogen-containing material including at least one material selected from polyol, polythiol, polyfunctional material containing both hydroxyl and SH groups, or mixtures thereof.

66. The sulfur-containing polyurethane of claim 64 prepared by

(a) reacting polyisocyanate, polyisothiocyanate, or mixture thereof;

and polythiol oligomer formed by the reaction of two or more different dienes and one or more dithiol, wherein stoichiometric ratio of sum of number of equivalents of all polythiols to sum of number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0;

1.0;

to form sulfur-containing polyurethane prepolymer; and

(b) reacting said sulfur-containing polyurethane prepolymer with active hydrogen-containing material including at least one material selected from trifunctional or higher-functional polyol, trifunctional or higher-functional polythiol, trifunctional or higher-functional material containing both hydroxyl and SH groups, or mixtures thereof.

67. A sulfur-containing polyurethane prepared by

(a) reacting polyisocyanate, polyisothiocyanate, or mixture thereof;

polythiol oligomer formed by the reaction of two or more different dienes and one or more dithiol, wherein stoichiometric ratio of the sum of the number of equivalents of all polythiols to the sum of the number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0;

1.0; and

active hydrogen-containing material including at least one material selected from trifunctional or higher-functional polyol, trifunctional or higher-functional polythiol, trifunctional or higher-functional material containing both hydroxyl and SH groups, or mixtures thereof, to form sulfur-containing polyurethane prepolymer; and

(b) reacting said sulfur-containing polyurethane prepolymer with active hydrogen-containing material including at least one material selected from polyol, polythiol, polyfunctional material containing both hydroxyl and SH groups, or mixtures thereof;

wherein at least one of (a) or (b) contains disulfide linkage.

69. The sulfur-containing polyurethane of claim 67 wherein said polythiol oligomer that is formed by the reaction of two or more different dienes and one or more dithiol, wherein stoichiometric ratio of sum of number of equivalents of all polythiols to sum of number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0:

1.0;

includes material containing disulfide linkage.

70. The sulfur-containing polyurethane of claim 67 wherein said active hydrogen-containing material of (a) includes material containing disulfide linkage.

71. The sulfur-containing polyurethane of claim 67 wherein said active hydrogen-containing material of (b) includes material containing disulfide linkage.

68. A sulfur-containing polyurethane prepared by

(a) reacting polyisocyanate, polyisothiocyanate, or mixture thereof;

and polythiol oligomer formed by the reaction of two or more different dienes and one or more dithiol, wherein stoichiometric ratio of sum of number of equivalents of all polythiols to sum of number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0;

1.0;

to form sulfur-containing polyurethane prepolymer; and

(b) reacting said sulfur-containing polyurethane prepolymer with active hydrogen-containing material including at least one material selected from trifunctional or higher-functional polyol, trifunctional or higher-functional polythiol, trifunctional or higher-functional material containing both hydroxyl and SH groups, or mixtures thereof;

wherein at least one of (a) or (b) contains disulfide linkage.

72. The sulfur-containing polyurethane of claim 68 wherein said polythiol oligomer formed by the reaction of two or more different dienes and one or more dithiol, wherein stoichiometric ratio of sum of number of equivalents of all polythiols to sum of number of equivalents of all dienes used to form said polythiol oligomer is greater than 1.0:

1.0;

includes material containing disulfide linkage.

73. The sulfur-containing polyurethane of claim 68 wherein said active hydrogen-containing material of (b) includes material containing disulfide linkage.