(12) Patent Application Publication (10) Pub. No.: US 2016/0304749 A1 Terai Et Al

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US 20160304749A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2016/0304749 A1 Terai et al. (43) Pub. Date: Oct. 20, 2016

(54) CYANOACRYLATE ADHESIVE (52) U.S. Cl. FORMULATION AND METHOD OF MAKING CPC. C09J 4/00 (2013.01); C09J 9/00 (2013.01); (71) Applicant: Toagosei America Inc., West Jefferson, C09J II/06 (2013.01); C08K 5/107 (2013.01) OH (US) (72) Inventors: Hiroyuki Terai, Dublin, OH (US); (57) ABSTRACT Masanari Shinoda, Dublin, OH (US); Masafumi Yamamoto, Takaoka (JP) A composition and method of making are provided for a (21) Appl. No.: 14/685,928 cyanoacrylate adhesive formulation comprising a calixarene stabilizer which exhibits improved shelf life, as measured by (22) Filed: Apr. 14, 2015 aging and stability testing, while maintaining good bonding Publication Classification performance. One embodiment comprises ethyl-2-cyano acrylate and 4-t-butylcaliX4arene-tetraacetic acid tetra (51) Int. Cl. ethyl ester as a stabilizer. A further embodiment comprises C09, 4/00 (2006.01) C09 II/06 (2006.01) mixing a suitable cyanoacrylate with Sufficient calixarene C09J 9/00 (2006.01) stabilizer to provide improved aging. Patent Application Publication Oct. 20, 2016 Sheet 1 of 3 US 2016/0304749 A1

Patent Application Publication Oct. 20, 2016 Sheet 2 of 3 US 2016/0304749 A1

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Patent Application Publication Oct. 20, 2016 Sheet 3 of 3 US 2016/0304749 A1

US 2016/0304749 A1 Oct. 20, 2016

CYANOACRYLATE ADHESIVE diol) chemical formula: CH(OH), SMILES: c1 cc FORMULATION AND METHOD OF MAKING (ccc1O)O, t-butylcatechol chemical formula: CoHO, SMILES: CC(C)(C)c1 ccc.(c(c1)O)O. hydroquinone CROSS-REFERENCES TO RELATED monomethyl ether (4-methyoxyphenol) chemical formula: APPLICATIONS ((CHO)CH(OH)), CAS: 150-76-5, SMILES: COc1ccc (cc1)O, and pyrogallol (1,2,3-trihydroxybenzene) chemi 0001 (Not Applicable) cal formula: (CH(OH)), SMILES: c1cc(c(c(c1)O)OOO, STATEMENT REGARDING CAS: 87-66-1. FEDERALLY SPONSORED RESEARCH AND 0008. Thickeners include methyl methacrylate-methyl DEVELOPMENT acrylate, acrylate resins such as poly(methyl methacrylate), poly(ethyl methacrylate), and poly(vinyl alkyl ethers) Such 0002 (Not Applicable) as poly(vinyl methyl ether). 0009 Promoters include 3- or 4-arm polyol podands THE NAMES OF THE PARTIES TO AJOINT (See, e.g., U.S. Pat. No. 4,386, 193 to Reich et al. issued May RESEARCH AGREEMENT 31, 1983), hydroxyl-terminated poly(dimethyl siloxane) 0003 (Not Applicable) OHISi)O(CH), H. poly(alkylene oxides, and so-called crown ethers. Crown ethers are of a class of cyclic REFERENCE TO AN APPENDIX compounds that consist of a ring containing a number of ether groups. R O R', where R and R are organic radi 0004 (Not Applicable) cals, generally carbon chains. Crown ethers are designated as X-crown-y, where X total number of atoms in the cyclic BACKGROUND OF THE INVENTION backbone and y number of ether structures (oxygen atoms). 0005. This description relates generally to cyanoacrylate Known crown ethers include, for example, 15-crown-5 adhesive formulations and more particularly to cyanoacry chemical formula: (CHO)s. SMILES: late adhesive formulations comprising calixarenes added to C1 COCCOCCOCCOCCO1 and 18-crown-6 chemical for improve aging and stability of the formulation. mula: C12H24O6. SMILES: 0006 Cyanoacrylate adhesives are a general class of C1 CCOCCOCCOCCOCCOCC1 O adhesives which are widely used and which cure quickly. C1COCCOCCOCCOCCOCCO1). Finally, calixarenes have Cyanoacrylate adhesives comprise cyanoacrylates, gener been used as promoters. Calixarenes are reported to provide ally, chemical formula: CHNOR, SMILES: NHC/C(=C) Substantially reduced fixture and cure times (See, e.g., U.S. C(=O)CR where R is an alkyl having up to eight carbon Pat. No. 4,718,966 to Harris, et al. issued Jan. 12, 1988.) and atoms and include, among others, methyl cyanoacrylate as curing accelerators (See, e.g., U.S. Pat. No. 6,547,985 to chemical formula: CHNO, SMILES: NHC/C(=C)C Tajima et al. issued Apr. 15, 2003.). (=O)CC or COC(=O)C(—C)CHN: ethyl cyanoacrylate 0010 While it is important to promote curing of cyano (ethyl-2-cyanoacrylate) chemical formula: CH7NO. acrylate adhesives, aging and stability are also important and SMILES: NHCC(—C)C(=O)CCC: propyl cyanoacrylate can be in tension with promoting curing. In general, cyano chemical formula: CHNO, SMILES: CCCOC(=O)C acrylate adhesives have a shelf life, if unopened, of about (—C)CHN; butyl cyanoacrylate chemical formula: one year from manufacture and one month if opened. Aging CHNO, SMILES: NHCC(—C)C(=O)CCCCC); octyl can cause cyanoacrylate adhesives to thicken (increased cyanoacrylate chemical formula: CHNO, SMILES: Viscosity) and cure more slowly. Control over increases in N#CC(C(OCCCCCCCC)—O)—C; and 2-octyl cyanoacry viscosity can improve the ability of the adhesive to with late chemical formula: CHNO, SMILES: C=C(CHN) stand the effects of aging and Stability and provide improved C(OC(C)CCCCCC)—O, isopropyl cyanoacrylate chemi performance than would otherwise be expected. A formula cal formula: CHNO, SMILES: C(#N)C(C(=O)CC(C)C) tion that is designed to a certain viscosity to provide good —C, CAS: 10586-17-1 isobutyl cyanoacrylate chemical initial performance can provide improved performance after formula: CHNO, SMILES: NHCC—CC(=O)CCCC(C) an extended shelf life if viscosity increases can be con C, CAS: 1069-55-2), and 2-ethoxyethyl cyanoacrylate trolled. A typical aging test involves storing a container (e.g., chemical formula: CHNO, SMILES: CCOC COC 20 grams) of the adhesive formulation at a specified tem (=O)C(=C)CHN, CAS: 21982-43-4). In addition to for perature and relative humidity for a specified period of time mulations with a single cyanoacrylate, cyanoacrylate adhe to predict shelf life. One aging test involves storing con sives may contain two or more cyanoacrylates. tainers of the adhesive at 50 deg. C. and 95 percent relative 0007. In addition to cyanoacrylates, cyanoacrylate adhe humidity for between 4 and 10 weeks. Alternatively, con sive formulations generally include various stabilizers to tainers of the adhesive are stored at 60 deg. C. for like inhibit premature polymerization of the cyanoacrylate in the periods of time. Samples are periodically removed from the container, thickeners to control viscosity for ease of appli aging environment and tested for viscosity, moisture, setting cation and to help control bonding, and promoters to accel time, and adhesive strength. Stability testing involves gath erate the rate of polymerization of the cyanoacrylates. Sta ering of more real-world shelf life data. For example, bilizers include those to control anionic polymerization, containers of the adhesive are stored at 25 deg. C. and 65 such as boron trifluoride methanol complex (BF.CHOH) percent relative humidity for between 3 and 18 months. As and sulfur dioxide (SO), as well as those to control radical with aging testing, samples are periodically removed from polymerization, Such as 2,2'-methylenebis(4-methyl-6-tert the stability testing environment and tested for viscosity, butylphenol) chemical formula: CHCHC(CH)(CH) moisture, setting time, and adhesive strength. Setting time is OHI, SMILES: CC(C)(C)c1cc(c(c(c1)C(C)(C)C)O)Cc2cc defined as the time to cure to a bond that cannot be easily (cc(c2O)C(C)(C)C)C(C)(C)C. hydroquinone (benzene-1,4 broken by hand. US 2016/0304749 A1 Oct. 20, 2016

0011. Therefore, there is a need for a cyanoacrylate 0020. In a further embodiment, the composition of matter adhesive formulation that extends shelf life without sacri comprises about 91.5 percent by weight cyanoacrylate and ficing curing. the cyanoacrylate is ethyl-2-cyanoacrylate. 0021. In a further embodiment, wherein the composition BRIEF SUMMARY OF THE INVENTION of matter comprises about 0.16 by weight calixarene and the 0012. It has been surprisingly and unexpectedly found calixarene is 4-t-butylcalix4arene-tetraacetic acid tetra that calixarenes, when added to cyanoacrylate adhesive ethyl ester. formulations in particular amounts, can, indeed, extend the 0022. In a further embodiment, the Viscosity Change shelf life, both aging and stability, without sacrificing curing Ratio of the composition of matter satisfies at least one of: performance. Various embodiments of the present invention less than about 1.2 following aging for 4 weeks at 50 deg. include cyanoacrylate adhesive formulations comprising, by C. and 95 percent relative humidity; less than about 1.2 weight of the formulation, between about 80 percent to following aging for 6 weeks at 50 deg. C. and 95 percent about 99.9 percent by weight of a suitable cyanoacrylate relative humidity; less than about 1.5 following aging for 8 adhesive; sufficient amounts of suitable stabilizers; between weeks at 50 deg. C. and 95 percent relative humidity; less about 0.1 to about 0.5 percent by weight of a suitable than about 4.0 following aging for 10 weeks at 50 deg. C. calixarene stabilizer, and, optionally, a suitable thickener. and 95 percent relative humidity; less than about 1.3 fol 0013. In one embodiment, a cyanoacrylate adhesive for lowing aging for 4 weeks at 60 deg. C.; less than about 1.6 mulation comprises, based upon the weight of the formula following aging for 6 weeks at 60 deg. C., less than about 1.8 tion, between about 80 percent to about 99.9 percent by following aging for 8 weeks at 60 deg. C.; and less than weight of a suitable cyanoacrylate adhesive; between about about 3.5 following aging for 10 weeks at 60 deg. C. 0.002 percent to about 0.01 percent by weight of a suitable 0023. In a further embodiment, the formulation retains stabilizer for anionic polymerization; between about 0.1 the average steel tensile strength following aging for 10 percent to about 0.3 percent by weight of a suitable stabilizer weeks at 50 deg. C. and 95 percent relative humidity for radical polymerization; between Zero percent to about 20 compared with the initial average steel tensile strength. percent by weight of a suitable thickener; and between about 0024. In a further embodiment, the composition of matter 0.01 to about 0.5 percent by weight of a suitable calixarene retains 90 percent of the average steel tensile strength stabilizer. The resulting adhesive formulation provides a following aging for 10 weeks at 60 deg. C. Viscosity Change Ratio (VCR) of the formulation of less 0025. In a further embodiment, the composition of matter than about 2.5 following aging for 10 weeks at 50 deg. C. retains the average steel tensile strength following stability and 95 percent relative humidity, where VCR is defined as testing for 18 months at 25 deg. C. and 65 percent relative the viscosity after aging or stability testing divided by the humidity. initial viscosity. For example, if the viscosity after 4 weeks at 50 deg. C. and 95 percent relative humidity in a 20-gram 0026. In a further embodiment, a process of preparing a container is 46.5 cps, and the initial viscosity was 45.0 cps, cyanoacrylate adhesive formulation comprises the step of the VCR will be 1.03. As discussed above, control over mixing between about 80 percent to about 99.9 percent, by increases in Viscosity translate into improved shelf life and weight of the formulation, of a suitable cyanoacrylate with the ability to maintain cure performance over time. between about 0.01 and 0.5 percent by weight of the 0014. In a further embodiment, the formulation com formulation of a suitable calixarene, wherein the Viscosity prises about 0.025 percent to about 0.25 percent by weight Change Ratio for the formulation satisfies at least one of: calixarene and the calixarene is 4-t-butylcaliX4arene-tet less than about 3.5 following aging for 10 weeks at 50 deg. raacetic acid tetraethyl ester. C. and 95 percent relative humidity; and less than about 3.5 0.015. In a further embodiment, the formulation com following aging for 10 weeks at 60 deg. C. prises about 0.16 percent by weight 4-t-butylcalix4arene 0027. In a further embodiment, the process includes tetraacetic acid tetraethyl ester. ethyl-2-cyanoacrylate as a cyanoacrylate and 4-t-butylcalix 0016. In a further embodiment, the formulation retains 4arene-tetraacetic acid tetraethyl ester as a calixarene. the average steel tensile strength following aging for 10 0028. In a further embodiment, the process provides a weeks at 50 deg. C. and 95 percent relative humidity formulation where the Viscosity Change Ratio of the for compared with the initial average steel tensile strength. mulation satisfies at least one of: less than about 1.2 fol 0017. In a further embodiment, the formulation retains 90 lowing aging for 4 weeks at 50 deg. C. and 95 percent percent of the average Steel tensile strength following aging relative humidity; less than about 1.2 following aging for 6 for 10 weeks at 60 deg. C. weeks at 50 deg. C. and 95 percent relative humidity; less 0.018. In a further embodiment, the formulation retains than about 1.5 following aging for 8 weeks at 50 deg. C. and the average steel tensile strength following stability testing 95 percent relative humidity; less than about 4.0 following for 18 months at 25 deg. C. and 65 percent relative humidity. aging for 10 weeks at 50 deg. C. and 95 percent relative 0019. In a further embodiment, a composition of matter humidity; less than about 1.3 following aging for 4 weeks at comprises, based upon the weight of the composition of 60 deg. C.; less than about 1.6 following aging for 6 weeks matter, between about 80 percent to about 99.9 percent by at 60 deg. C.; less than about 1.8 following aging for 8 weeks weight of a suitable cyanoacrylate and between about 0.1 to at 60 deg. C.; and less than about 3.5 following aging for 10 about 0.5 percent by weight of a suitable calixarene stabi weeks at 60 deg. C. lizer, wherein the Viscosity Change Ratio of the formulation 0029. In a further embodiment, the process provides a satisfies at least one of less than about 3.5 following aging formulation which retains the average Steel tensile strength for 10 weeks at 50 deg. C. and 95 percent relative humidity; following aging for 10 weeks at 50 deg. C. and 95 percent and less than about 3.5 following aging for 10 weeks at 60 relative humidity compared with the initial average steel deg. C. tensile strength. US 2016/0304749 A1 Oct. 20, 2016

0030. In a further embodiment, the process provides a numerous cyanoacrylates, and combinations of cyanoacry formulation which retains 90 percent of the average steel lates are also suitable candidates for embodiments of the tensile strength following aging for 10 weeks at 60 deg. C. present invention, as are other concentrations of the cyano 0031. In a further embodiment, the process provides a acrylate. formulation which retains the average Steel tensile strength 0040 Similarly, while boron trifluoride methanol com following stability testing for 18 months at 25 deg. C. and 65 plex and Sulfur dioxide are included as anionic polymeriza percent relative humidity. tion stabilizers, and at the indicated proportions, other anionic polymerization stabilizers at other proportions are BRIEF DESCRIPTION OF THE SEVERAL also possible. FIGURES 0041 Table 1 lists 2,2'-methylenebis(4-methyl-6-tert-bu 0032 FIG. 1 is Table 2 and shows Initial Formulation tylphenol) and hydroquinone as radical polymerization sta Data for eight embodiments (Formulation Embodiments, bilizers at the indicated proportions. However, other radical FE) and two Conventional Formulations (CF). polymerization stabilizers at other proportions are also pos 0033 FIG. 2 is Table 3 and shows results for an Aging sible. Test at 50 deg. C. and 95 percent relative humidity with a 0042. As further shown in Table 1, two exemplary thick 20-gram container for eight Formulation Embodiments and eners are included, methyl methacrylate-methyl acrylate two Conventional Formulations. (Delpowder 70HTM from Asahi Kasei has been used with 0034 FIG. 3 is Table 4 and shows results for an Aging good results) and poly(methyl methacrylate) (Acrycon Test at 60 deg. C. with a 20-gram container for eight ACTM from Mitsubishi Rayon has been used with good Formulation Embodiments and two Conventional Formula results) at the indicated proportions. Other thickeners at tions. other proportions are also possible. 0035 FIG. 4 is Table 5 and shows results for a Stability 0043 Finally, a calixarene, 4-t-butylcalix4arene-tet Test at 25 deg. C. and 65 percent relative humidity with a raacetic acid tetraethyl ester, has been added which provides 20-gram container for one Formulation Embodiment and enhanced stability as discussed above. As shown in Table 1, two Conventional Formulations. the proportion of the indicated calixarene ranges from 0036. In describing the various embodiments of the 0.025% w/w (FE8) to 0.16% w/w (FE1-FE7). invention, specific terminology will be resorted to for the 0044 Shown in Table 1 for comparison are two crown sake of clarity. However, it is not intended that the invention ethers, 15-crown-5 and 18-crown-6, which are typically be limited to the specific term(s) so selected and it is to be used as promoters. understood that each specific term includes all technical 0045 Turning now to FIG. 1, Table 2 shows Initial equivalents which operate in a similar manner to accomplish Formulation Data for the formulations listed in Table 1. a similar purpose. Looking first at Viscosity, these tests were performed under ASTM D 1084-97 (Reapproved 2005), entitled Standard DETAILED DESCRIPTION OF THE Test Methods for Viscosity of Adhesives. Looking next at INVENTION Setting Time, the times for steel for FE1-FE8 are consistent 0037 Illustrative embodiments of the present invention at five seconds. The performance for steel of CF1 and CF2 along with two conventional formulations for comparison are affected by the proportions of the crown ethers. Looking are shown is Table 1 below. at chloroprene rubber (CR), a peel test, while not wishing to TABLE 1. Composition (% ww.

Component FE1 FE2 FE4 FE5 FE6 FE7 FE8 CF1 CF2 Ethyl-2-Cyanoacrylate 91.5 91.5 91.5 91.5 91.5 91.5 91.5 91.5 91.5 97.8 Boron Trifluoride Methanol Complex O.004 O.004 O.004 O.OO6 O.004 OOO4 O.OO4 OOO4 OOO)4 Sulfur Dioxide O.OO2 O.004 2,2'-Methylenebis(4-methyl-6-tert-butylphenol) O.1 O.2 O.1 O.2 O.2 O.2 O.2 O.2 O.12 Hydroquinone O.O6 O.O6 O.O6 O.O6 Methyl Methacrylate-Methyl Acrylate 8.5 8.5 8.5 8.5 8.5 8.5 8.5 8.5 (MMA-MA copolymer) Poly(Methyl Methacrylate) 2.2 (PMMA) 4-t-Butyl-calix4arene-tetraacetic O16 O16 O16 O16 O.25 O.10 O.OS O.O2S acid tetraethyl ester 15-Crown-5 O16 18-Crown-6 O.O1

0038. Data are expressed in weight percent (% w/w). be bound by any particular theory, the setting time for FE3 Embodiments of the present invention are listed as Formu may be higher due to the presence of sulfur dioxide. The lation Embodiments (FE), while conventional formulations, results for FE1-FE8 for birch plywood, a tensile shear test, included for comparison purposes only, are listed as Con are all comparable. The results for FE1-FE8 for paper, a ventional Formulations (CF). tensile shear test, are all comparable. The results for leather, 0039 While ethyl-2-cyanoacrylate is used in the illus a tensile shear test, are comparable for FE1-FE5. While not trated embodiments, and at 91.5% w/w, as discussed above, wishing to be bound by any particular theory, it is possible US 2016/0304749 A1 Oct. 20, 2016

that the presence of lower levels of the calixarene account modifications may be adopted without departing from the for the difference. Finally, Initial Test Data are shown for invention or scope of the following claims. tensile testing of steel under ASTM D2095-96 (Reapproved 1. The composition of matter of claim 11, wherein the 2002), entitled Standard Test Method for Tensile Strength of composition of matter further comprises: Adhesives by Means of Bar and Rod Specimens. between about 0.1 percent to about 0.3 percent by weight 0046 Turning now to FIG. 2, Table 3 shows Aging Test of a suitable stabilizer for radical polymerization; and data at 50 Deg. C and 95 percent relative humidity. As between Zero percent to about 20 percent by weight of a discussed above, control over viscosity changes (VCR) can suitable thickener. have a marked effect on shelf life. At four weeks, as Table 2. The composition of matter of claim 11, wherein the 3 clearly shows, FE1-FE8, containing the calixarene, all Initial Setting Time for chloroprene rubber is less than about exhibit significantly better VCR values than CF1 or CF2. 5 seconds. 3. The composition of matter of claim 11, wherein the 0047. Setting Time for chloroprene rubber shows little, if Initial Setting Time for leather is less than about 5 seconds. any degradation, but for FE7 and FE8. While not wishing to 4. The composition of matter of claim 11, wherein the be bound by any particular theory, it is possible that the cyanoacrylate is chosen from the list consisting essentially presence of lower levels of the calixarene account for the of methyl cyanoacrylate, ethyl cyanoacrylate, butyl cyano differences shown. acrylate, octyl cyanoacrylate, 2-octyl cyanoacrylate, isopro 0048 Looking now at Table 3 at six weeks, FE1-FE8, pyl cyanoacrylate, isobutyl cyanoacrylate, and 2-ethoxy containing the calixarene, all continue to exhibit signifi ethyl cyanoacrylate. cantly better VCR performance than CF1 or CF2. Good 5. The composition of matter of claim 11, wherein the results are shown for Setting Time for chloroprene rubber. composition of matter comprises between about 90 percent Finally, the tensile test results for steel indicate improved to about 99.9 percent by weight cyanoacrylate and the bond strength over the values in the Initial Data shown in cyanoacrylate is ethyl-2-cyanoacrylate. FIG. 1, Table 2. 6. The composition of matter of claim 11, wherein the composition of matter comprises about 0.025 percent to 0049 Looking now at Table 3 at eight weeks, FE1-FE8, about 0.25 percent by weight calixarene stabilizer and the containing the calixarene, all continue to exhibit signifi calixarene Stabilizer is 4-t-butylcalix4arene-tetraacetic cantly better VCR values than CF1 or CF2. Possibly due to acid tetraethyl ester. the increased proportion of the calixarene in FE5, the VCR 7. The composition of matter of claim 6, wherein the value is higher than the other FE formulations. composition of matter comprises about 0.16 percent by 0050 Looking now at Table 3 at ten weeks, FE1-FE8, weight 4-t-butylcalix4arene-tetraacetic acid tetraethyl containing the calixarene, all continue to exhibit signifi ester. cantly better VCR values than CF1 or CF2. As with the 8. The composition of matter of claim 6, wherein the results at four, six, and eight weeks, FE5 shows a higher composition of matter retains the average Steel tensile VCR value, possible due to the increased proportion of the strength following aging for 10 weeks at 50 deg. C. and 95 calixarene in that formulation. percent relative humidity compared with the initial average 0051 Turning now to FIG. 3, Table 4 shows Aging Test steel tensile strength. data at 60 Deg. C. FE1-FE8 show consistently better VCR 9. The composition of matter of claim 6, wherein the values than CF1 or CF2. The tensile test results for FE1 and composition of matter retains 90 percent of the average steel FE2 for steel indicate improved bond strength over the tensile strength following aging for 10 weeks at 60 deg. C. values in the Initial Data shown in FIG. 1, Table 2 and over 10. The composition of matter of claim 6, wherein the the values shown for CF1 and CF2 Likewise, all FE formu composition of matter retains the average Steel tensile lations but FE5, discussed above, indicate better VCR values strength following stability testing for 18 months at 25 deg. than CF1 and CF2 at ten weeks. C. and 65 percent relative humidity. 11. A composition of matter, comprising, based upon the 0052 Turning now to FIG.4, Table 5 shows Stability Test weight of the composition of matter: data at 25 deg. C. and 65 percent relative humidity. As between about 80 percent to about 99.9 percent of a shown, FE2 gives consistently better results than both CF1 suitable cyanoacrylate; between about 0.002 percent to and CF2 in nearly all categories over the entire time period. about 0.01 percent of a suitable stabilizer for anionic 0053 Thus, the addition of a calixarene, a known pro polymerization; and moter, unexpectedly provides improved shelf life while between about 0.1 to about 0.5 percent of a suitable maintaining good bonding performance. calixarene stabilizer, wherein the Viscosity Change 0054. This detailed description in connection with the Ratio of the formulation satisfies at least one of: figures is intended principally as a description of the pres less than about 1.2 following aging for four weeks at 50 ently preferred embodiments of the invention, and is not deg. C. and 95 percent relative humidity; intended to represent the only forms in which the present less than about 1.2 following aging for six weeks at 50 invention may be formulated or produced. The description deg. C. and 95 percent relative humidity; sets forth the formulations and processes of making those less than about 1.5 following aging for eight weeks at 50 formulations in connection with the described embodiments. deg. C. and 95 percent relative humidity; It is to be understood, however, that the same or equivalent less than about 2.5 following aging for 10 weeks at 50 functions and features may be accomplished by different deg. C. and 95 percent relative humidity; embodiments that are also intended to be encompassed less than about 3.5 following aging for 10 weeks at 50 within the spirit and scope of the invention and that various deg. C. and 95 percent relative humidity; US 2016/0304749 A1 Oct. 20, 2016

less than about 4.0 following aging for 10 weeks at 50 20. The process of claim 18, wherein the Viscosity deg. C. and 95 percent relative humidity; Change Ratio of the formulation satisfies at least one of: less than about 1.3 following aging for four weeks at 60 less than about 1.2 following aging for 4 weeks at 50 deg. deg. C.; C. and 95 percent relative humidity; less than about 1.6 following aging for six weeks at 60 less than about 1.2 following aging for 6 weeks at 50 deg. deg. C.; C. and 95 percent relative humidity; less than about 1.8 following aging for eight weeks at 60 less than about 1.5 following aging for 8 weeks at 50 deg. deg. C., and C. and 95 percent relative humidity; less than about 3.5 following aging for 10 weeks at 60 less than about 4.0 following aging for 10 weeks at 50 deg. C. deg. C. and 95 percent relative humidity; 12. The composition of matter of claim 5, wherein the less than about 1.3 following aging for 4 weeks at 60 deg. composition of matter comprises about 91.5 percent by C.; weight ethyl-2-cyanoacrylate. less than about 1.6 following aging for 6 weeks at 60 deg. 13-17. (canceled) C.; 18. A process of preparing a cyanoacrylate adhesive less than about 1.8 following aging for 8 weeks at 60 deg. formulation, comprising the step of C.; and (a) mixing between about 80 percent to about 99.9 per less than about 3.5 following aging for 10 weeks at 60 cent, by weight of the formulation, of a suitable cya deg. C. noacrylate with between about 0.01 and 0.5 percent by weight of the formulation of a suitable calixarene, 21. The process of claim 20, wherein the formulation wherein the Viscosity Change Ratio for the formulation retains the average Steel tensile strength following aging for satisfies at least one of 10 weeks at 50 deg. C. and 95 percent relative humidity less than about 3.5 following aging for 10 weeks at 50 compared with the initial average steel tensile strength. deg. C. and 95 percent relative humidity; and 22. The process of claim 20, wherein the formulation less than about 3.5 following aging for 10 weeks at 60 retains 90 percent of the average steel tensile strength deg. C. Question: The spreadsheet just says “dry”. Is following aging for 10 weeks at 60 deg. C. there a RH value associated with “dry”? 23. The process of claim 20, wherein the formulation 19. The process of claim 18, wherein: retains the average steel tensile strength following stability the cyanoacrylate is ethyl-2-cyanoacrylate; and testing for 18 months at 25 deg. C. and 65 percent relative the calixarene is 4-t-butylcalix4arene-tetraacetic acid humidity. tetraethyl ester.