Toughened cyanoacrylate compositions

Patent metadata

Field	Value
Publication number	US-11299651-B2
Application number	US-202016841583-A
Country	US
Kind code	B2
Filing date	Apr 6, 2020
Priority date	Oct 6, 2017
Publication date	Apr 12, 2022
Grant date	Apr 12, 2022

Abstract

Curable cyanoacrylate compositions are reported that comprise cyanoacrylate and a thermoplastic polyurethane (TPU) components. Such compositions are toughened cyanoacrylate compositions exhibiting long term viscosity stability when stored for prolonged periods at room temperature (25° C.). TPU components are reported having structural units in which at least one of the structural units has the formula —O—R1—O—Ar—O—R2—O—, wherein Ar is a C6-C20 aromatic group with at least one aromatic ring; R1 is a C2-C10 alkyl group; and R2 is a C2-C10 alkyl group. The thermoplastic polyurethane (TPU) component may be present in the curable cyanoacrylate composition from about 1 wt % to about 40 wt %, for example from about 2 wt % to about 30 wt %, such from about 3 wt % to about 20 wt %, suitably from about 5 wt % to about 10 wt %, based on the total weight of the composition.

First claim

The invention claimed is:

1. A curable cyanoacrylate composition comprising:
(i) a cyanoacrylate; and
(ii) a thermoplastic polyurethane (TPU) having a chain formed from structural units;

wherein at least one of the structural units of the chain of the TPU (ii) has the formula:
—O—R 1 —O—Ar—O—R 2 —O—,

wherein:
Ar is a C 6 -C 20 aromatic group with at least one aromatic ring;
R 1 is a C 2 -C 10 alkyl group; and
R 2 is a C 2 -C 10 alkyl group,

and wherein the TPU (ii) is present in the curable cyanoacrylate composition from about 1 wt % to about 40 wt %, based on the total weight of the composition.

2. A curable cyanoacrylate composition as claimed in claim 1 wherein the aromatic group Ar in the structural unit with the formula:
—O—R 1 —O—Ar—O—R 2 —O—

is selected from: benzene, methyl benzene, dimethylbenzene, ethylbenzene, trimethylbenzene, tetramethylbenzene, diethylbenzene, triethylbenzene, naphthalene, methylnaphthalene, dimethylnaphthalene, trimethylnaphthalene, tetraethylbenzene, tetramethylnaphthalene, pentamethylnaphtalene, hexamethylnaphthalene, ethylnaphthalene, diethylnaphthalene, or triethylnaphthalene.

3. A curable cyanoacrylate composition as claimed in claim 1 wherein the aromatic group Ar in the structural unit with the formula:
—O—R 1 —O—Ar—O—R 2 —O—

is a benzene group or a naphthalene group.

4. A curable cyanoacrylate composition according to claim 1 wherein at least one of the alkyl groups R 1 and R 2 in the structural unit with the formula:
—O—R 1 —O—Ar—O—R 2 —O—

is a C 2 alkyl group.

5. A curable cyanoacrylate composition according to claim 1 wherein the alkyl groups R 1 and R 2 in the structural unit with the formula:
—O—R 1 —O—Ar—O—R 2 —O—

are both C 2 alkyl groups.

6. A curable cyanoacrylate composition as claimed in claim 1 wherein the structural unit with the formula:
—O—R 1 —O—Ar—O—R 2 —O—

is formed from hydroquinone bis( 2 -hydroxyethyl) ether (HQEE).

7. A curable cyanoacrylate composition according to claim 1 , wherein the structural unit with the formula:
—O—R 1 —O—Ar—O—R 2 —O—

is present in the TPU (ii) in an amount from about 0.5 wt % to about 50 wt %, based on the total weight of the thermoplastic polyurethane (ii).

8. A curable cyanoacrylate composition as claimed in claim 1 , wherein the TPU (ii) is prepared using a polyol selected from the group consisting of a polyester-polyol, a co-polyester-polyol, a polyether-polyol, a co-polyether-polyol, a polycaprolactone-polyol, and a co-polycaprolactone-polyol.

9. A curable cyanoacrylate composition as claimed in claim 8 , wherein the polyol used in the preparation of the thermoplastic polyurethane (TPU) (ii) is a polyester-polyol or a co-polyester-polyol.

10. A curable cyanoacrylate composition as claimed in claim 9 , wherein the polyol used in the preparation of the TPU (ii) is a co-polyester formed from a dicarboxylic acid and 1,6-hexanediol.

11. A curable cyanoacrylate composition as claimed in claim 10 wherein the polyol used in the preparation of the TPU) (ii) is a linear polyester-polyol formed from a dicarboxylic acid and 1,6-hexanediol, and wherein the linear polyester-polyol has a hydroxyl number of from about 1 to about 60 mg KOH/g, as measured according to ASTM E222.

12. A curable cyanoacrylate composition according to claim 1 wherein the cyanoacrylate (i) is selected from the group consisting of ethyl 2-cyanoacrylate and β-methoxycyanoacrylate.

13. A curable cyanoacrylate composition according to claim 1 wherein the cyanoacrylate (i) is present in an amount of about 50 wt % to about 99 wt % based on the total weight of the cyanoacrylate composition.

14. A curable cyanoacrylate composition according to claim 1 wherein the cyanoacrylate (i) is present in an amount of about 60 wt % to about 90 wt % based on the total weight of the cyanoacrylate composition.

15. A curable cyanoacrylate composition according to claim 1 wherein the TPU (ii) is present in an amount of about 1 wt % to about 40 wt % based on the total weight of the cyanoacrylate composition.

16. A curable cyanoacrylate composition according to claim 1 wherein the TPU (ii) is present in an amount of about 5 wt % to about 20 wt % based on the total weight of the cyanoacrylate composition.

17. A curable cyanoacrylate composition according to claim 1 further comprising a stabiliser in an amount from about 0.0005 wt % to about 5 wt % based on the total weight of the cyanoacrylate composition.

18. A curable cyanoacrylate composition according to claim 17 wherein the stabiliser is selected from BF 3 , SO 2 , or HF.

19. A curable cyanoacrylate composition according to claim 1 further comprising ultra-high molecular weight polyethylene in an amount from about 0.05 wt % to about 5 wt % based on the total weight of the cyanoacrylate composition.

20. A curable cyanoacrylate composition as claimed in claim 1 wherein the viscosity of the uncured composition as measured at 25° C. does not decrease by greater than 5% from the starting viscosity over 30 days of storage at 25° C.

21. A curable cyanoacrylate composition as claimed in claim 1 , wherein the composition further comprises an antioxidant at an amount from about 0.01 wt % to about 1 wt %, by weight based on the total weight of the composition.

22. A curable cyanoacrylate composition as claimed in claim 21 , wherein the antioxidant is pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate).

23. A method of preparing a curable cyanoacrylate composition that retains a stable viscosity for at least 30 days when stored at 25° C., the viscosity measured at 25° C., wherein the method involves preparing a composition comprising from about 60 wt % to about 90 wt % of a cyanoacrylate with from about 1 wt % to about 40 wt % of a TPU, wherein the percentages are by weight based on the total weight of the composition and wherein the TPU has been prepared from:
a polyol selected from the group consisting of a polyester-polyol, a co-polyester-polyol, a polyether-polyol, a co-polyether-polyol, a polycaprolactone-polyol, and a co-polycaprolactone-polyol; and
an isocyanate compound selected from the group consisting of 1,4-diisocyanatobenzene (PPDI), toluene diisocyanate (TDI), 4,4′-diphenylmethane diisocyanate (4,4′-MDI), 2,4′-diphenylmethane diisocyanate (2,4′-MDI), polymethylene poly(phenyl isocyanate) (PMDI), 1,5-naphthalene diisocyanate (NDI), bitolylene diisocyanate (TODI), 1,3-xylene diisocyanate (XDI),p-1,1,4,4-tetramethylxylene diisocyanate (p-TMXI), m-1,1,3,3-tetramethylxylylene diisocyanate (m-TMXDI), 1,6-diisocyanato-2,4,4-trimethylhexane, 1,4-cyclohexane diisocyanate (CHDI), 1,4-cyclohexanebis(methylene isocyanate) (BDI), 1,3-bis(isocyanatomethyl)cyclohexane (H6XDI), 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI), dicyclohexylmethane diisocyanate (H12MDI), and triphenylmethane -4,4′,4″-triisocyanate; and
a chain extender with the formula:
HO—R 1 —O—Ar—O—R 2 —OH,

wherein Ar is a C 6 -C 20 aromatic group with at least one ring,
R 1 is a C 2 -C 10 alkyl group, and
R 2 is a C 2 -C 10 alkyl group.

24. The method according to claim 23 , wherein the TPU has been prepared from a polyol selected from the group consisting of a polyester-polyol, a co-polyester-polyol, a polyether-polyol, a co-polyether-polyol, a polycaprolactone-polyol, and a co-poly

Assignees

• Henkel IP & Holding GmbH
• Henkel Ag & Co Kgaa

Inventors

• Barnes Rory R
• Tully Raymond
• Burns Barry

Classifications

• C08F222/322

  Alpha-cyano-acrylic acid ethyl ester, e.g. ethyl-2-cyanoacrylate · CPC title

• C08G18/3221

  hydroxylated esters of carboxylic acids other than higher fatty acids · CPC title

• C08G18/3215

  containing aromatic groups or benzoquinone groups · CPC title

• C08G18/44

  Polycarbonates · CPC title

• C08F222/328

  Alpha-cyano-acrylic acid with more than one oxygen in the ester moiety · CPC title