Polycarbonate diol and producing method thereof, and polyurethane and active energy ray-curable polymer composition both formed using same
A novel polycarbonate diol is useful as a raw material for producing a polycarbonate diol-based polyurethane with a high degree of hardness, superior abrasion resistance, and superior hydrophilicity. The polyurethane is useful in paints, coating agents, synthetic leathers, artificial leathers, and highly-functional elastomers, or the like. The polycarbonate diol is also useful for producing an active-energy radiation curable polymer composition giving a cured film having superior contamination resistance and high degree of hardness. The curable polymer composition contains a urethane(meth)acrylate oligomer obtained from the polycarbonate diol. The polycarbonate diol is obtained, for example, by reacting two specific types of diols with diester carbonate in the presence of a transesterification catalyst. The catalyst has a metal of Group 1 or 2 on the periodic table. A metal content of the transesterification catalyst is 100 weight ppm or less.
1. A polycarbonate diol, obtained by reacting (i) at least one diol selected from isosorbide, isomannide, and isoidide, (ii) a diol having 1 to 15 carbons which may contain a hetero atom, and (iii) a diester carbonate, wherein:
the reaction of (i), (ii), and (iii) is carried out in the presence of a transesterification catalyst;
the transesterification catalyst is either a compound containing a metal of Group 1 of the periodic table or a compound containing a metal of Group 2 of the periodic table;
the polycarbonate diol contains the transesterification catalyst in an amount of 100 ppm or less, calculated as a weight ratio of catalyst metal in the polycarbonate diol;
the number average molecular weight of the polycarbonate diol is 250 to 5,000;
at least part of a molecular chain of the polycarbonate diol contains a repeating unit (A)
and a repeating unit (B)
where X is a divalent group having 1 to 15 carbons which may contain a hetero atom; and the polycarbonate diol has a terminal (A) ratio (I) of 1.2 to 1.8, the terminal (A) ratio (I) being calculated by the following formula:
terminal ( A ) ratio ( I )={(number of terminal units ( A ) in molecular chain)/(total number of terminal units ( A ) and terminal units ( B ) in molecular chain)}/{(number of units ( A ) in molecular chain)/(total number of units ( A ) and units ( B ) in molecular chain)}.
2. The polycarbonate diol according to claim 1 , wherein the polycarbonate diol contains the transesterification catalyst in an amount of 0.1 to 100 ppm, calculated as a weight ratio of catalyst metal in the polycarbonate diol.
3. The polycarbonate diol according to claim 1 , wherein the transesterification catalyst is a compound containing a metal of Group 2 of the periodic table.
4. The polycarbonate diol according to claim 1 , wherein the highest temperature during the reaction of (i), (ii), and (iii) is less than 180° C.
5. The polycarbonate diol according to claim 1 , wherein the number average molecular weight of the polycarbonate diol is 250 to 900.
6. A method for obtaining the polycarbonate diol of claim 1 , comprising:
reacting (i) at least one diol selected from isosorbide, isomannide, and isoidide, (ii) a diol having 1 to 15 carbons which may contain a hetero atom, and (iii) a diester carbonate, in the presence of a transesterification catalyst, to obtain a polycarbonate diol:
wherein:
the transesterification catalyst is either a compound containing a metal of Group 1 of the periodic table or a compound containing a metal of Group 2 of the periodic table; and
the highest temperature during the reaction of (i), (ii), and (iii) is less than 180° C.
7. The method according to claim 6 , wherein the transesterification catalyst is a compound containing a metal of Group 2 of the periodic table.
8. The polycarbonate diol according to claim 1 , wherein the diester carbonate (iii) is diphenyl carbonate.
9. The polycarbonate diol according to claim 1 , wherein the polycarbonate diol comprises unreacted diester carbonate in an amount of 1 weight % or less, based on the total weight of the polycarbonate diol.
10. The polycarbonate diol according to claim 1 , wherein the diol (i) contains 20 ppm or less of formic acid.
11. The polycarbonate diol according to claim 1 , wherein 5% or less of all molecular chain terminals of the polycarbonate diol are either an alkyloxy group or an aryloxy group.
12. The polycarbonate diol according to claim 1 , wherein the Hazen color number value (APHA value: according to JIS K0071-1) of the polycarbonate diol is 100 or less.
13. The polycarbonate diol according to claim 1 , wherein the molecular weight distribution (Mw/Mn) of the polycarbonate diol is 1.5 to 3.5.
14. A method, comprising:
reacting the polycarbonate diol according to claim 1 and a polyisocyanate to obtain a prepolymer; and
reacting the prepolymer with a chain extender.
15. A method, comprising:
mixing the polycarbonate diol according to claim 1 , a polyisocyanate, and a chain extender together at once; and
reacting the obtained mixture.
16. The polycarbonate diol according to claim 1 , wherein 95% or more of molecular chain terminals of the polycarbonate diol are hydroxyl groups.
17. The method according to claim 6 , wherein 95% or more of molecular chain terminals of the obtained polycarbonate diol are hydroxyl groups.
18. The polycarbonate diol according to claim 1 , wherein the highest temperature during the reaction of (i), (ii), and (iii) is less than 180° C., wherein the number average molecular weight of the polycarbonate diol is 250 to 900, and wherein the molecular weight distribution (Mw/Mn) of the polycarbonate diol is 1.5 to 3.5.