Polyester-polyol compositions for polyurethane foam with improved hydrolytic stability

Abstract

The invention relates to compositions of glycidyl ester used as a stabilizer in polyurethane foams formulations having a good resistance to hydrolysis, improved damping with equivalent or improved physical properties, and high sound absorption capacity. The mono or poly-carboxylic acids glycidyl ester is used in amount of 0.1 to 10 weight % over the polyester polyol resin.

Claims

1. A composition of polyurethane foams, comprising: an organic polyisocyanate; and a blend comprising: (a) a polyester polyol resin produced by a polycondensation reaction of an organic dicarboxylic acid or a derivative, and a polyol mixture; and (b) a poly-carboxylic acid glycidyl ester in amount of 0.1 to 10 weight % over the polyester polyol resin.

2. The composition of claim 1, wherein the poly-carboxylic acid glycidyl ester (b) is a poly-carboxylic glycidyl ester of an aliphatic poly acid with 18 to 36 carbon atoms or a cycloaliphatic poly acid with 5 to 15 carbon atoms.

3. The composition of claim 1, wherein the poly-carboxylic acid glycidyl ester (b) is blended with the polyester polyol resin (a) at an end of the polycondensation reaction at a temperature above 120° C.

4. The composition of claim 1, wherein the poly-carboxylic acid glycidyl ester (b) is blended with the polyester polyol resin (a) at a temperature below 120° C.

5. The composition of claim 1, wherein the poly-carboxylic acid glycidyl ester (b) is present in a level of 0.2 to 8 weight % over the polyester polyol resin.

6. The composition of claim 1, wherein the poly-carboxylic acid glycidyl ester (b) is present in a level of 0.3 to 5 weight % over the polyester polyol resin.

7. The composition of claim 1, wherein the poly-carboxylic acid glycidyl ester (b) is present in a level of 0.5 to 1 weight % over the polyester polyol resin.

8. The composition of claims 1, further comprising: a catalyst for condensing the polyester polyol resin and the organic polyisocyanate: and a blowing agent.

9. The composition of claim 1, further comprising a chain extender, an additive, or both.

10. The composition of claim 1, wherein the blend has an acid value below 2 mg KOH/g.

11. The composition of claim 1, wherein the derivative is an anhydride.

12. A polyurethane foam composition, comprising: an organic polyisocyanate; and a mixture comprising: a polyester polyol resin produced by a polycondensation reaction of: an organic dicarboxylic acid or an anhydride; and a polyol mixture; and a poly-carboxylic acid glycidyl ester in an amount of 0.1 to 10 weight % over the polyester polyol resin.

13. The polyurethane foam composition of claim 12, wherein the poly-carboxylic acid glycidyl ester is a poly-carboxylic acid glycidyl ester of an aliphatic poly acid with 18 to 36 carbon atoms.

14. The polyurethane foam composition of claim 12, wherein the poly-carboxylic acid glycidyl ester is a poly-carboxylic acid glycidyl ester of a cycloaliphatic poly acid with 5 to 15 carbon atoms.

15. The polyurethane foam composition of claim 12, wherein the poly-carboxylic acid glycidyl ester is mixed with the polyester polyol resin at an end of the polycondensation reaction at a temperature above 120° C.

16. A polyurethane foam composition, comprising: an organic polyisocyanate; and a mixture comprising: a polyester polyol resin produced by reacting: an anhydride; and a polyol mixture; and a poly-carboxylic acid glycidyl ester in an amount of 0.1 to 10 weight % over the polyester polyol resin.

17. The polyurethane foam composition of claim 16, wherein the anhydride is a phthalic anhydride.

18. The polyurethane foam composition of claim 16, wherein the mixture has an acid value below 1 mg KOH/g.

19. The polyurethane foam composition of claim 16, wherein the poly-carboxylic acid glycidyl ester is a poly-carboxylic acid glycidyl ester of an aliphatic poly acid with 18 to 36 carbon atoms.

20. The polyurethane foam composition of claim 16, wherein the poly-carboxylic acid glycidyl ester is a poly-carboxylic acid glycidyl ester of a cycloaliphatic poly acid with 5 to 15 carbon atoms.

Description

DISCLOSURE OF THE INVENTION

(1) Accordingly, the invention provides polyurethane foams with good resistance to hydrolysis and improved mechanical properties and particularly with a high compression strength and favourable damping behaviour.

(2) More in particular the invention relates to the compositions a polyester polyol known in the art can be used, including those produced when a dicarboxylic acid or anhydride is reacted with an excess of a diol. Non-limiting examples include adipic acid or phthalic acid or phthalic anhydride reacting with ethylene glycol or butanediol. However, most common polyester polyols are made from phthalic, isophthalic and terephthalic acids and derivatives. Esterification of these acids with polyol initiators such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butanediol, polyethylene glycols of various molecular weights, glycerin, pentanetriol, and the like can yields polyester polyols with different physical properties, molecular weights and molecular architectures but all characterized by their poor hydrolytic stability. Also, polyester polyols useful in the present invention can be produced by reacting a lactone with an excess of a diol, for example, caprolactone reacted with propylene glycol.

(3) The above polyester-polyol resins are combined with a glycidyl ester of a mono or poly-carboxylic acids in amount of 0.1 to 10 weight % over the polyester polyol resin. The glycidyl ester is a mono carboxylic acids glycidyl ester of aliphatic tertiary saturated acid or α,α-branched alkane acid, which contain mostly 9 to 15 carbon atoms, such as Cardura 9 or Cardura 10 (available from Hexion).

(4) In another embodiment the glycidyl ester is a poly carboxylic acids glycidyl ester of aliphatic poly acid with 18 to 36 carbon atoms or cycloaliphatic poly acid with 5 to 15 carbon atoms, such as for example Epikote 760 or Heloxy 71 (available from Hexion).

(5) The blend of the glycidyl ester and the polyester-polyol resin can be done at the end of the manufacturing of the polyol resin at a temperature above 120° C. to reduce the acid value below 2 mg KOH/g, preferably below 1 mg KOH/g, or by blending during the preparation of the part A at temperature below 120° C., of the polyurethane foam compositions.

(6) The part A of the formulation comprise the polyol resin and the glycidyl ester, a blowing agent, such as water, a catalyst for the polyol-isocyanate condensation such as tin derivatives, amines and additives.

(7) The range of glycidyl esters as described above is from 0.1 to 10 weight % of the polyester-polyol resin. The preferred range is form 0.2 to 8 weight %, the most preferred range is from 0.3 to 5 weight % and even further preferred range is from 0.5 to 1 weight % all over the polyester polyol resin.

EXAMPLES

(8) Raw Material

(9) Stepanol PS 3152: Diethylene Glycol-phtalic anhydride based polyester polyol ex Stepan;

(10) Cardura 10 ex Hexion

(11) Epikote 758: ex Hexion

(12) DMEA: N,N-dimethylethanolamine (ex Sigma)

Example 1

(13) Reaction Condition

(14) Ratio acid/Acid Scavenger 1:1.5

(15) Reaction Temperature: 160° C.

(16) Reaction Time: 3 hours

(17) Procedure

(18) Mixture of polyester polyol with the Acid scavenger.

(19) Heat the mixture at the reaction temperature

(20) Follow the acid content

(21) Results

(22) TABLE-US-00001 Raw material Addition Addition of Starting of Cardura10 Epikote material 10 GP 758 Acid value, 2.8 0.22 0.82 mgKOH/g

Example 2

(23) Storage Stability of the Part a (Polyol+Water+DMEA)

(24) The compositions of glycidyl ester used as stabilizer in polyurethane foams formulations having a good resistance to hydrolysis is demonstrated below,

(25) Preparation and Storage Conditions

(26) Part A is prepared by mixing Polyester polyol with

(27) Water=2.78%

(28) DMEAt=3.06%

(29) Reaction Temperature: 80 and 100° C.

(30) Reaction Time: 1 day

(31) Procedure

(32) Part A is mixed with the acid scavenger: Cardura 10 and Epikote 758

(33) The acid scavenger ratios are 0%, 0.5%, 1%, 2% and 5%.

(34) The mixture is placed in the oven at the temperature described here above 1 day at 80° C. and 100° C.

(35) The acid value is measured after 1 day. (initial acid value 2.8 mg KOH/gr)

(36) Results

(37) Storage stability at 80° C. —1 Day, as acid value increase.

(38) TABLE-US-00002 Ac. Scavenger level, % 0 0.5 1 2 5 Cardura 10 5.63 4.45 3.61 3.25 2.61 Epikote 758 5.56 3.89 3.68 3.46 3.36
Storage stability at 100° C. —1 Da, as acid value increase.

(39) TABLE-US-00003 Ac. Scavenger level, % 0 0.5 1 2 5 Cardura 10 15.29 12.24 10.99 10.22 8.17 Epikote 758 15.29 12.28 11.53 9.97 6.68