Accelerator compositions, particularly for use with cyanoacrylate adhesive compositions

Abstract

Provided herein is a composition comprising: a) at least one F-substituted 3 or 4 carbon alkene with at least one Cl- or Br-substituent thereon, wherein said alkene is non-flammable as measured by Setaflash closed-cup method apparatus as described in ASTM D3278-95, has a calculated molecular weight in the range of about 90 to about 700, and has a boiling point greater than about 30°C; and b) at least one N-containing aromatic compound, present in the composition in an amount of about 0.1 percent by weight to about 2 percent by weight.

Description

2024P00331ACCELERATOR COMPOSITIONS, PARTICULARLY FOR USE WITH CYANOACRYLATE ADHESIVE COMPOSITIONSBACKGROUNDField

[0001] Provided herein is a composition comprising:a) at least one F-substituted 3 or 4 carbon alkene with at least one Cl-or Br-substituent thereon, wherein said alkene is non-flammable as measured by Setaflash closed-cup method apparatus as described in ASTM D3278-95, has a calculated molecular weight in the range of about 90 to about 700, and has a boiling point greater than about 30°C; andb) at least one N-containing aromatic compound, present in the composition in an amount of about 0.1 percent by weight to about 2 percent by weight.Brief Description of Related Technology

[0002] Cyanoacrylate adhesives are ubiquitous for many consumer and industrial adhesive applications because of their excellent ability to rapidly bond a wide range of substrates, generally in a number of minutes and depending on the particular substrate, often in a number of seconds. Cyanoacrylate adhesives are particularly suitable for the assembly of small, close-fitting parts. Their universality derives partly from the fact that polymerization of the cyanoacrylate monomer, which makes up the bulk of most cyanoacrylate adhesives, is initiated by nucleophiles found on many surfaces under normal atmospheric conditions. The initiation by surface chemistry means that sufficient initiating species are available when two surfaces are in close contact with a small layer of cyanoacrylate adhesive between the two surfaces. Under these conditions a strong bond is obtained in a short time. Thus, in essence the cyanoacrylate adhesive is often referred to as an instant adhesive.

[0003] Generally, performance of the cyanoacrylate adhesive is quite rapid for most substrates. But with some substrates cure times for cyanoacrylate adhesives can be significantly longer. In these instances, it may be beneficial to use a primer, activator or accelerator to initiate cure. In some cases, an accelerator can be added directly to the2024P00331cyanoacrylate to form a one-part system or separated in a second housing to form a two part system and mixed with the cyanoacrylate shortly before use. Alternatively, an accelerator may be disposed directly onto the substrate in a low boiling solvent prior to cyanoacrylate adhesive application or in reverse order with the cyanoacrylate adhesive applied first with the accelerator applied thereafter.

[0004] Unfortunately, there are a number of disadvantages associated with the use of existing solvent-based activators. It is frequently difficult to specify exactly the amount of activator used (particularly in manual operations) and overuse of the activator is associated with lower bond strength. Occasionally, use of some activators can lead to production of lower bond strengths or failure to form a bond, depending on the substrates used. In addition, activated polymerization can result in opaque, whitened bond lines. Also, many of the low boiling point solvents used can attack plastics. Often, there is a solvent extraction / notification requirement associated with the use of low boiling point organic solvents in the workplace. And significantly to this end many of the solvents or carriers in use today are flammable and thus subject to enhanced regulatory labelling requirements and environmental and workplace safety scrutiny.

[0005] The state of the art has addressed in the past the issue of the desire of activators, even for cyanoacrylate compositions, that offer different physical properties.

[0006] For instance, US Patent No. 8,933,168 (Hally) is directed to and claims two-part cyanoacrylate adhesive composition comprising: Part A: a cyanoacrylate; and Part B: (a) a 2-substituted benzothiazole, and (b) a plasticizer selected from triacetin, dioctyl phthalate, dibutyl phthalate, trioctyl trimellitate, dioctyl adipate, dioctyl glutarate, butyl cyanoacetate, trimethyl trimellitate, diethylene glycol dibenzoate, diethyl malonate, triethyl-O-acetyl citrate, benzylbutyl phthalate, dipropylene glycol dibenzoate, diethyl adipate, tributyl-O-acetyl citrate, dimethyl sebacate, tributyl-O-acetyl citrate, triethyl-O-acetyl citrate, dipropylene glycol dibenzoate, diethylene glycol dibenzoate, benzylbutyl phthalate, dibutyl adipate, dibutyl sebacate, dicapryl adipate, dicapryl phthalate, diethyleneglycol dibenzoate, diethyl adipate, diethyl glutarate, diethyl malonate, diethyl pimelate, diisononyl phthalate, dimethyl adipate, dimethyl glutarate, dimethyl sebacate, dioctyl phthalate, diprophyleneglycol dibenzoate, ethyl caproate, glyceroltrioleate, isopropyl myristate, methyl laurate, methyl stearate, pentaerythritol tetraacrylate,2024P00331pentaerythriotoltetrabenzoate, poly(neopentyl glycoladipate), tributyl-O-acetyl citrate, tricapryl trimellithate, triethyl-O-acetyl citrate, trihexyl trimellithate, tris(isopropyl phenyl)phosphate, trimethyl trimellithate, trioctyl trimellithate, and combinations thereof, wherein the 2-substituted benzothiazole is selected from a specified group of chemical compounds.

[0007] Other efforts in this regard include:Great Britain Patent No. 1,414,317, which describes cyanoacrylate adhesive accelerator / activator compounds having — N — C(-)=S or — N=C(-) — S — groups, but which do not contain Lewis acid groups, which are noted as tending to inhibit cure. The compounds as accelerator are added directly to the adhesive at the time of use, or are applied to at least one of the substrates prior to application of adhesive when used as activator. Examples of suitable activators in the GB '317 patent include certain N-disubstituted metallic dithiocarbamates, N-substituted benzothiazole-2-sulfenamides and N,N-tetrasubstituted thiuram mono- or oligosulfides.

[0008] European Patent No. EP 785865 describes a non-environmentally hazardous and non-volatile adhesive promoter composition for promotion of adhesive cure comprising amongst others, tert-butyl benzothiazole sulfenamide and N-oxydiethylene benzothiazoles-2-sulfenamide, present in an amount of about 0.01% to about 10% by weight. The activators are provided in a high boiling point solvent, wherein the activator and adhesive formulation may be provided as two liquids and cure may be achieved by manual mixing or by co-extrusion through a static mixer. The method is useful, since it allows metered addition of activator. In particular, tert-butyl benzothiazole sulfenamide and N-oxydiethylene benzothiazole-2 -sulfanamides have been used in this manner.

[0009] Japanese Patent Publication No. 62-022877 describes the use of aromatic amines as activators. The main associated advantage with use of these compounds being that there is no unpleasant odour and relevantly good efficient acceleration is provided, particularly when N,N-Dimethyl-p-Toluidine (DMPT) is used.

[0010] U.S. Patent No. 6,547,917 describes superior activator compounds for accelerating hardening having the structural element — N=C — S — S — C=N — . The compounds described such as dithiopyridine, N-t-butyl-2-benzothiazole-sulfenamide, N-cyclohexyl-2-benzothiazole-sulfenamide, dibenzothiazyl disulfide, promote hardening to2024P00331occur within a few seconds. These compounds are superior since they allow a substantially longer waiting time between application of the activator and application of the adhesive and thus tend to avoid superficial hardening.

[0011] Notwithstanding the state of the art, it would be desirable to provide an activator composition that does not use a solvent or liquid carrier that is subject to such regulatory and workplace scrutiny and does not possess the technical issues noted above.SUMMARY

[0012] The present invention solves these concerns.

[0013] Thus, provided herein is a composition comprising:a) at least one F-substituted 3 or 4 carbon alkene with at least one Cl-or Br-substituent thereon, wherein said alkene is non-flammable as measured by Setaflash closed-cup method apparatus as described in ASTM D3278-95, has a calculated molecular weight in the range of about 90 to about 700, and has a boiling point greater than about 30°C; andb) at least one N-containing aromatic compound, present in the composition in an amount of about 0.1 percent by weight to about 2 percent by weight.

[0014] The composition is useful as an activator for cyanoacrylate compositions. More specifically, the composition may be disposed onto at least a portion of a surface to be bonded of a first substrate over which a cyanoacrylate may be disposed prior to mating a second substrate with the first one to adhesively bond the two substrates together. Or the composition may be disposed over a cyanoacrylate composition which was disposed onto at least a portion of a surface to be bonded of a first substrate.Thereafter, a second substrate may be disposed over the composition to make the first one to adhesively bond the two substrates together.

[0015] Desirably, the at one least F-substituted 3 or 4 carbon alkene with at least one Cl- or Br-substituent thereon of the composition is non-flammable as measured by Setaflash closed-cup method apparatus as described in ASTM D3278-95, has a calculated molecular weight in the range of about 94 to about 627, and has a boiling point greater than about 30°C.2024P00331

[0016] Also provided herein is a kit comprising the composition and a cyanoacrylate component.DETAILED DESCRIPTION

[0017] As noted above, provided herein is a composition comprising:a) at least one F-substituted 3 or 4 carbon alkene with at least one Cl-or Br-substituent thereon, wherein said alkene is non-flammable as measured by Setaflash closed-cup method apparatus as described in ASTM D3278-95, has a calculated molecular weight in the range of about 90 to about 700, and has a boiling point greater than about 30°C; andb) at least one N-containing aromatic compound, present in the composition in an amount of about 0.1 percent by weight to about 2 percent by weight.

[0018] In one embodiment, the alkene of a) is a 3 carbon alkene.

[0019] In another embodiment, the alkene of a) is a 4 carbon alkene.

[0020] In yet another embodiment, the alkene of a) has at least 3 F substituents.

[0021] In still yet another embodiment, the alkene of a) has at least 3 F substituents, all on the same carbon atom.

[0022] In a further embodiment, the alkene of a) has at least 1 Cl substituent.

[0023] In yet a further embodiment, the alkene of a) has at least 2 Cl substituents.

[0024] In still yet a further embodiment, the alkene of a) has at least 1 Br substituent.

[0025] The alkene of a) may be selected from 1 ,2-dichloro-3,3,3-trifluoropropene; cis-1-chloro-3,3,3-trlfluoropropene; and (Z)-1-chloro-2,3,3-trifluoroprop-1-ene; and combinations thereof.

[0026] The alkene of a) should have a boiling point greater than about 30°C up to about 100°C.

[0027] In one embodiment, the N-containing aromatic compound is a toluidine, a pyridine or a benzothiazole.

[0028] In one aspect of this embodiment, the N-containing aromatic compound is a toluidine selected from N,N-dimethyl-o-toluidine or N,N-dimethyl-p-toluidine.

[0029] In another aspect of this embodiment, the N-containing aromatic compound is pyridine or a derivative thereof, such as 2 ,2’-dithioldipyridine.2024P00331

[0030] In yet another aspect of this embodiment, the N-containing aromatic compound is a 2-substituted benzothiazole or a derivative thereof. For instance, the 2-substituted benzothiazole or a derivative thereof may have substitutions at the 2-position of the benzothiazole ring, such as C1-C4 alkyl groups like methyl, ethyl, propyl or butyl groups.

[0031] Suitable alkene substituents at the 2-position of the benzothiazole ring may be C1-C4 alkene groups such as an allyl, a propylene or a butylene groups. The alkene bond may be terminal to the 2-position of the benzothiazole ring or may be in an intermediate position along the hydrocarbon chain.

[0032] Suitable ether substituents at the 2-position of the benzothiazole ring may be C1-C10 alkylether group, a branched or unbranched C1-C10 alkylether group containing at least one double bond or triple bond, in the alkyl chain. Desirably, the ether group oxygen atom is directly linked to the benzothiazole at the 2-position.

[0033] Other suitable benzothiazole compounds have a sulfenamide positioned at the 2-position of the benzothiazole compounds. Suitable sulfenamide substituents include sulfenamide wherein the amide portion of the sulfenamide is a cyclohexylamine.

[0034] Alternatively, the benzothiazole compounds may have an alkylbenzyl group at the 2-position of the benzothiazole. Suitably the alkylbenzyl group may comprise a branched or unbranched C1-C4 alkyl chain, which is further substituted with a benzyl group at any of the C1-C4 positions. Desirably, the compound has the benzyl group at the terminal carbon in the hydrocarbon chain.

[0035] Suitably, the benzothiazole compounds may have a halo group at the 2-position of the benzothiazole ring, which may be Cl, Bror F. Benzothiazole compounds having at least one Cl substituent on the benzene ring of the benzothiazole provides compounds which are particularly desirable as activators for cyanoacrylate compositions.

[0036] The 2-substituted benzothiazoles or derivatives thereof of the invention may be selected from:2024P003312-[(tcrl-bulylaminojihio]-l,3-bcnzothiazDl-5-o5-bromo-2-inethyl-L3 -benzothiazoleVb-dichloro^-mcihyl-l^-bcr zolhiazolc6-bromo-2-tnethyl-l, 3 -benzo thiazoleCl6>7-dichloro-2-rnethy]-l,3-benzothiazolt*4,5,6,7-tetrai luoro-2-jnethy 1-1.3-beiizotluazok2, S-dimethyl-kl benzc thiazole2024P00331 2 (allyd oxy) 1,3-benzo thiazole2-methyl-5 -(methylthio)-!, 3-benzothiazole2-( ethylthio)-] .3-benzothiazole2-(he?cyloxy)-l, 3-benzothiazole2-(l,3-dinicihylbuioxy>k3-bcnz0thiazolc2-(Octadccyhhio)bcnzothiazolc2 -( I - eth y 1 but o xy ) - 1 , 3 -ben 70 th i a zo I e2-(octyloxy)-1.3 benzothiazole2024P003312024P00331

[0037] The composition is useful as an activator for cyanoacrylate compositions. More specifically, the composition may be disposed onto at least a portion of a surface to be bonded of a first substrate over which a cyanoacrylate may be disposed prior to mating a second substrate with the first one to adhesively bond the two substrates together. Or the composition may be disposed over a cyanoacrylate composition which was disposed onto at least a portion of a surface to be bonded of a first substrate.Thereafter, a second substrate may be disposed over the composition to mate the first one to adhesively bond the two substrates together.

[0038] Desirably, the at one least F-substituted 3 or 4 carbon alkene with at least one Cl- or Br-substituent thereon of the composition is non-flammable as measured by Setaflash closed-cup method apparatus as described in ASTM D3278-95, has a calculated molecular weight in the range of about 94 to about 627, and has a boiling point greater than about 30°C.

[0039] Also provided herein is a kit comprising the composition and a cyanoacrylate component. More specifically, the cyanoacrylate component of the kit may be selected2024P00331from H2C=C(CN)-COOR, wherein R is selected from alkyl, alkoxyalkyl, cycloalkyl, alkenyl, aralkyl, aryl, allyl and haloalkyl groups. Prime among such selections are ethyl-2-cyaonacrylate, butyl cyanoacrylates, octyl cyanoacrylates, and [3-methoxyethyl cyanoacrylate.

[0040] The invention as so described is further illustrated by the examples presented below, which in no way should be construed to limit the breadth of this technical advance.EXAMPLES

[0041] In Table 1 , Sample Nos. 1 -5, each within the scope of the present invention, were formulated with the listed constituents in the respective noted amounts. Sample No. 6 was provided for comparative purposes.Table 1Sample Nos. / Amt (wt%) Constituents1 2 3 4 5 6!cis-1-Chloro-3,3,3-trifluoropropene 99.3 49.65(Z)-1-Chloro-2,3,3-trifluoroprop-1-ene* 99.3 49.65 99.5Amolea AS-300AT*** 99.3Ethoxy-nonafluorobutane@ 99.1 N,N-dimethyl-p-toluidine 0.7 0.7 0.7 0.7 0.7 2,2'-dithioldipyridine 0.5Odor mask 0.2Total 100 100 100 100 100 100!LOCTITE SF 7109® 3M NOVEC 7200Contains ~10% of the E-isomerAMOLEA AS-300AT is reported by the supplier to be an azeotropic mixture of 1-Chloro- 2,3,3-trifluoroprop-1-ene (30-40 %) and trans-1 ,2, dichloroethylene (60-70%)

[0042] Each of Sample Nos. 1-5 was visually observed to be clear and colorless and remain so at a temperature of about 22°C over a period of time of about 1 to about 1.5 months and based on data obtained under accelerated aging conditions of about 38°C the samples may have a shelf life of up to about two years and may be longer. Each of2024P00331these samples was also determined to be non-flammable as measured in accordance with UL-94 V-0. More specifically, non-flammability as measured by the flash point method described in ASTM D3278-95, a flash point equal to or greater than 93°C is a measure of non-flammability. These samples each had a flash point of equal to or greater than 93°C.

[0043] In Table 2, bond strength measurements were recorded on various substrates both with a prior application of Sample Nos. 1-6 and with a subsequent application of Sample Nos. 1-6. Fixture times were also measured and recorded in Table 2.Table 2Physical Property with pre-application Sample Nos.of CA adhesive# 1 2 3 4 5 6 Tensile shear strength, 2 min RTC, N / mm2On grit blasted mild steel (GBMS) 7.6 9.1 10.3 8.0 10.8 8.6 On PVC 4.3$3.7$4.1$4.2$3.9$4.2$Fixture time (seconds)On GBMS <=5 5-10 5-10 <=5 5-10 <=5 On PVC <=5 <=5 5-10 <=5 5-10 <=5 Physical Property with post-applicationof CA adhesive#% of Area with "blooming" 0 0 0 0 0 48LOCTITE 416, available commercially from Henkel Corporation, Rocky Hill, CT, US Substrate failure

[0044] Where no accelerator was applied to the substrate(s) and CA was simply used to make an adhesive bond, the following data was observed and collected: no tensile strength was measured on GBMS and only 0.9 N / mm2was observed on PVC; a fixture time of greater than 90 seconds was observed on GBMS and 75-90 seconds was observed on PVC; and as no appreciable adhesive bond was formed no blooming could be observed either.

Claims

2024P00331What is Claimed is:

1. A composition comprising:a) at least one F-substituted 3 or 4 carbon alkene with at least one Cl-or Br-substituent thereon, wherein said alkene is non-flammable as measured by Setaflash closed-cup method apparatus as described in ASTM D3278-95, has a calculated molecular weight in the range of about 90 to about 700, and has a boiling point greater than about 30°C; andb) at least one N-containing aromatic compound, present in the composition in an amount of about 0.1 percent by weight to about 2 percent by weight.

2. The composition of Claim 1 , wherein the alkene is a 3 carbon alkene.

3. The composition of Claim 1 , wherein the alkene is a 4 carbon alkene.

4. The composition of Claim 1 , wherein the alkene has at least 3 F substituents.

5. The composition of Claim 1 , wherein the alkene has at least 3 F substituents, all on the same carbon atom.

6. The composition of Claim 1 , wherein the alkene has at least 1 Cl substituent.

7. The composition of Claim 1 , wherein the alkene has at least 2 Cl substituents.

8. The composition of Claim 1 , wherein the alkene has at least 1 Br substituent.2024P003319. The composition of Claim 1 , wherein the alkene is a member selected from the group consisting of 1 ,2-dichloro-3,3,3-trifluoropropene; cis-1-chloro-3,3,3-trlfluoropropene; and (Z)-1-chloro-2,3,3-trifluoroprop-1-ene; and combinations thereof.

10. The composition of Claim 1 , wherein the alkene has a boiling point greater than about 30°C up to about 100°C.

11. The composition of Claim 1 , wherein the N-containing aromatic compound is a toluidine, a pyridine or a benzothiazole.

12. The composition of Claim 1 , wherein the N-containing aromatic compound is N,N-dimethyl-o-toluidine or N,N-dimethyl-p-toluidine.

13. The composition of Claim 1 , wherein the N-containing aromatic compound is pyridine or a derivative thereof.

14. The composition of Claim 1 , wherein the N-containing aromatic compound is 2,2’-dithioldipyridine.

15. The composition of Claim 1 , wherein the N-containing aromatic compound is a 2-substituted benzothiazole or a derivative thereof.

16. The composition of Claim 1 , wherein the N-containing aromatic compound is a 2-substituted benzothiazole or a derivative thereof, wherein the 2-substituent is an alkyl, an alkene, an alkylbenzyl, an alkylamino, an alkoxy, an alkylhydroxy, an ether, a sulfenamide, a thioalkyl or a thioalkoxy group.

17. The composition of Claim 1 , wherein the N-containing aromatic compound is a 2-substituted benzothiazole is selected from the group consisting of:2024P003312-[(tcrl-bulylaminojihio]-l,3-bcnzothiazDl-5-o5-bromo-2-inethyl-L3 -benzothiazoleVb-dichloro^-mcihyl-l^-bcr zolhiazolc6-bromo-2-tnethyl-l, 3 -benzo thiazoleCl6>7-dichloro-2-rnethy]-l,3-benzothiazolt*4,5,6,7-tetrai luoro-2-jnethy 1-1.3-beiizotluazok2, S-dimethyl-kl benzc thiazole2024P00331 2 (allyd oxy) 1,3-benzo thiazole2-methyl-5 -(methylthio)-!, 3-benzothiazole2-( ethylthio)-] .3-benzothiazole2-(he?cyloxy)-l, 3-benzothiazole2-(l,3-dinicihylbuioxy>k3-bcnz0thiazolc2-(Octadccyhhio)bcnzothiazolc2 -( I - eth y 1 but o xy ) - 1 , 3 -ben 70 th i a zo I e2-(octyloxy)-1.3 benzothiazole2024P003312024P0033118. The composition of Claim 1 , wherein the at one least F-substituted 3 or 4 carbon alkene with at least one Cl- or Br-substituent thereon, wherein said alkene is non-flammable as measured by Setaflash closed-cup method apparatus as described in ASTM D3278-95, has a calculated molecular weight in the range of about 94 to about 627, and has a boiling point greater than about 30°C.

19. A kit comprising the composition of Claim 1 and a cyanoacrylate component.

20. The kit of Claim 19, wherein the cyanoacrylate component is H2C=C(CN)-COOR, wherein R is selected from alkyl, alkoxyalkyl, cycloalkyl, alkenyl, aralkyl, aryl, allyl and haloalkyl groups.

Images