Color Change Cyanoacrylate Adhesives

2008/030903 A1 ||||||||||||||ll||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||| (19) World Intellectual Property Organization _ in (51) (21) (22) (25) (26) (30) (71) (72) (74) International Bureau (43) International Publication Date 13 March 2008 (13.03.2008) International Patent Classification: C09] 4/00 (2006.01) C09B 11/02 (2006.01) International Application Number: PCT/US2007/077679 International Filing Date: 6 September 2007 (06.09.2007) Filing Language: English Publication Language: English Priority Data: 60/824,970 8 September 2006 (08.09.2006) US Applicant: 3M INNOVATIVE PROPERTIES COM- PANY [US/U S]; 3M Center, Post Office Box 33427, Saint Paul, Minnesota 55133-3427 (US). Inventors: MELANCON, Kurt C.; 3M Center, Post Of- fice Box 33427, Saint Paul, Minnesota 55133-3427 (US). TIERS, George Van Dyke; 3M Center, Post Office Box 33427, Saint Paul, Minnesota 55133-3427 (US). LIEN, Larry A.; 3M Center, Post Office Box 33427, Saint Paul, Minnesota 55133-3427 (US). PEARSON, Scott D.; 3M Center, Post Office Box 33427, Saint Paul, Minnesota 55133-3427 (US). Agents: ADAMSON, Trisha D. et al.; 3M Center, Office of Intellectual Property Counsel Post Office Box 33427, Saint Paul, Minnesota 55133-3427 (US). (81) (34) (12) INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) ' ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||| (10) International Publication Number WO 2008/030903 A1 Designated States (unless otherwise indicated, for every kind of national protection available ): AE, AG, AL, AM, AT, AU, AZ, BA, BB, BG, BH, BR, BW, BY, BZ, CA, CH, CN, CO, CR, CU, CZ, DE, DK, DM, DO, DZ, EC, EE, EG, ES, FI, GB, GD, GE, GH, GM, GT, HN, HR, HU, ID, IL, IN, IS, JP, KE, KG, KM, KN, KP, KR, KZ, LA, LC, LK, LR, LS, LT, LU, LY, MA, MD, ME, MG, MK, MN, MW, MX, MY, MZ, NA, NG, NI, NO, NZ, OM, PG, PH, PL, PT, RO, RS, RU, SC, SD, SE, SG, SK, SL, SM, SV, SY, TJ, TM, TN, TR, TT, TZ, UA, UG, US, UZ, VC, VN, ZA, ZM, ZW. Designated States (unless otherwise indicated for every kind of regional protection available ): ARIPO (BW, GH, GM, KE, LS, MW, MZ, NA, SD, SL, SZ, TZ, UG, ZM, ZW), Eurasian (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), European (AT, BE, BG, CH, CY, CZ, DE, DK, EE, ES, FI, FR, GB, GR, HU, IE, IS, IT, LT, LU, LV, MC, MT, NL, PL, PT, RO, SE, SI, SK, TR), OAPI (BF, BJ, CF, CG, CI, CM, GA, GN, GQ, GW, ML, MR, NE, SN, TD, TG). Declarations under Rule 4.17: as to applicants entitlement to apply for and be granted a patent (Rule 4.1 7(ii)) as to the applicants entitlement to claim the priority of the earlier application (Rule 4.1 7(iii)) Published: (54) Title: COLOR CHANGE CYANOACRYLATE ADHESIVES with international search report before the expiration of the time limit for amending the claims and to be republished in the event of receipt of amendments (57) Abstract: A cyanoacrylate—based adhesive composition is disclosed. The cyanoacrylate—based adhesive composition includes a cyanoacrylate monomer, and a bleachable dye including a Michler’s hydrol cation or derivatized Michler’s hydrol cation, paired with a non—nucleophilic anion that provides a stable color to the cyanoacrylate—based adhesive. WO 2008/030903 PCT/US2007/077679 COLOR CHANGE CYANOACRYLATE ADHESIVES Cross-Reference to Related Application This application claims the benefit of United States Provisional Patent 5 Application Serial Number 60/824,970, filed on September 8, 2006, which is incorporated by reference herein. Background The present disclosure relates generally to color change cyanoacrylate adhesives and methods of using the same. 10 Cyanoacrylate adhesives, also known as “super glues,” are a versatile family of adhesives known to cure in seconds and provide strong adhesion to a wide variety of surfaces. In spite of these noteworthy attributes, several issues exist that limit the popularity of this adhesive class with consumers. One issue with cyanoacrylate adhesives is that these adhesives bond instantly l5 with skin. This issue is compounded by the fact that cyanoacrylate adhesives are usually colorless and difficult to observe when applied to a substrate. The inability of the end- user to observe where the adhesive is (or is not), as well as whether the adhesive is cured, often leads to unintended bonding of skin to itself or other substrates. Some cyanoacrylate adhesives are lightly tinted to provide the end-user some 20 ability to discriminate where the adhesive has and has not been applied. However, these color tints are often so light that a thinly applied adhesive layer is not perceptible. Increasing the intensity of color tint so that the thinly applied adhesive layer is perceptible, results in the cured adhesive remaining visible on the completed project which may be objectionable to the consumer. 25 Summary In an exemplary implementation, cyanoacrylate-based adhesive compositions are disclosed that include a cyanoacrylate monomer and a bleachable dye such as, for example, a Michler’s hydrol cation or Michler’s hydrol cation derivative, that provides a 30 stable color to the uncured cyanoacrylate-based adhesive when paired with a non- nucleophilic anion. WO 2008/030903 PCT/US2007/077679 In another exemplary implementation, the method includes combining an appropriately stabilized cyanoacrylate monomer with a bleachable dye such as, for example, a Michler’s hydrol cation or derivatized Michler’s hydrol cation paired with a non-nucleophilic anion to form a dye pair. The stabilized cyanoacrylate monomer and 5 dye pair forms a cyanoacrylate-based adhesive composition. The dye pair provides a stable color to the cyanoacrylate-based adhesive composition. These and other aspects of the adhesives according to the subject invention will become readily apparent to those of ordinary skill in the art from the following detailed description together with the Examples. 1 0 Detailed Description Accordingly, the present disclosure is directed to color change cyanoacrylate adhesives and methods of using the same. In particular, the cyanoacrylate adhesive is colored in the uncured state and becomes colorless or light-colored upon cure. In 15 another embodiment, the cyanoacrylate adhesive is a first color in the uncured state and changes to a second color upon cure. These color change adhesives can allow the end- user to easily observe the lay of the adhesive as it is dispensed, and additionally, affords a means of visually assessing uniformity of bond lines, as well as determining where excess adhesive has been applied. These color change adhesives can allow the end-user 20 a means of indicating the state-of-the-cure of the adhesive. In one example, if during the gluing operation the adhesive is colored, it is not cured, and accordingly, when said adhesive is fully cured, it is colorless or lightly colored. Normally if exposed adhesive is colorless or lightly colored it is sufficiently cured so that it may be touched without fear of bonding to the skin. While the present invention is not so limited, an appreciation of 25 various aspects of the invention will be gained through a discussion of the examples provided below. Unless otherwise indicated, all numbers expressing feature sizes, amounts, and physical properties used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the 30 contrary, the numerical parameters set forth in the following specification and attached WO 2008/030903 PCT/US2007/077679 claims are approximations that all variation depending upon the desirable properties sought to be obtained by those skilled in the art utilizing the teachings disclosed herein. The recitation of numerical ranges by endpoints includes all numbers subsumed within that range (e.g. l to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5) and any range 5 within that range. As used in this specification and the appended claims, the singular forms “a”, “an”, and “the” encompass embodiments having plural referents, unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term “or” is generally employed in its sense including “and/or” unless the content clearly 10 dictates otherwise. The term “polymer” will be understood to include polymers, copolymers (e.g., polymers formed using two or more different monomers), oligomers and combinations thereof, as well as polymers, oligomers, or copolymers that can be formed in a miscible blend. 15 The term “alkyl” refers to a straight or branched chain monovalent hydrocarbon radical optionally containing one or more heteroatomic substitutions independently selected from S, O, Si, or N. Alkyl groups generally include those with one to twenty atoms or from one to ten atoms. Alkyl groups may be unsubstituted or substituted with those substituents that do not interfere with the specified function of the composition. 20 Substituents include alkoxy, hydroxy, mercapto, amino, alkyl substituted amino, or halo, for example. Examples of “alkyl” as used herein include, but are not limited to, methyl, ethyl, n-propyl, n-butyl, n-pentyl, isobutyl, and isopropyl, and the like. The phrase “stable color” will be understood to mean that a color or color intensity that visually persists for at least 14 days as measured by the test method 25 described in the Examples herein. For example, a flowable cyanoacrylate adhesive is said to possess a “stable color” if the color or color intensity (e.g., blue color) visually persists for at least 14 days in a sealed container. In some embodiments, the samples remain usefully colored for a period of at least six months, or at leastl year, or at least 2 years. 30 Unlike conventional pH indicators which are sequentially reversible, i.e., reversing color upon sequential exposure altemately to acid and to base, the bleachable WO 2008/030903 PCT/US2007/077679 dyes of the present invention tend to bleach irreversibly when formulated in color change cyanoacrylate compositions. The cyanoacrylate-based adhesive composition described herein includes a cyanoacrylate monomer and a bleachable dye cation paired with a non-nucleophilic 5 anion that provides the bleachable dye with a stable color. As this cyanoacrylate-based adhesive cures, it becomes colorless or lightly colored. In many embodiments, the bleachable dye cation paired with a non-nucleophilic anion is blended with the cyanoacrylate monomer prior to being applied to a substrate. In some embodiments, the bleachable dye cation paired with a non-nucleophilic anion is not blended with the 10 cyanoacrylate monomer before the cyanoacrylate monomer is disposed on a substrate. In these embodiments, the bleachable dye cation paired with a non-nucleophilic anion can be disposed on the substrate and then the cyanoacrylate monomer is disposed on the bleachable dye cation paired with a non-nucleophilic anion. The bleachable dye cation or cations can be chosen to produce any color, as 15 desired. In many embodiments, the bleachable dye cation produces a blue or deep blue color. In many embodiments, the bleachable dye cation is formed from a Michler’s hydrol (i.e., 4,4’-bis(dimethylamino)benzhydrol) or a derivative thereof. Michler’s hydrol or 4,4’-bis(dimethylamino)benzhydrol) is commercially available (from Sigma-Aldrich, St. Louis, MO 63103) and has the following chemical H3C\N : T S N/CH3 / I \cH 3 H30 H 20 structure: Michler’s hydrol is a dye base and is colorless in its free (pure) form, and because this dye base by virtue of its amine substituents is nucleophilic, and as such will cause immediate polymerization of cyanoacrylate monomer, it is acidified prior to introduction 25 into the cyanoacrylate described herein. When acidified, Michler’s hydrol cation provides a blue (cyan) color: the color intensity varying with the acidified dye concentration. Selection of the appropriate acid stabilizer or non-nucleophilic anion to maintain dye (color) stability upon aging is described below. While not being bound by any particular theory, it is believed that Michler’s hydrol cation is a dye that is degraded 30 (e.g., bleached) concomitant with curing of the cyanoacrylate adhesive composition. 4 WO 2008/030903 PCT/US2007/077679 Derivatized Michler’s hydrol can be used for the bleachable dye cation. Useful derivatized Michler’s hydrols include, for example, the following molecules: bis[4-(4-morpholinyl)phenyl]methanol (CAS# l 23 344- l 3 -8) having a chemical structure: N O H N 0 fl mil? Q 5 l , l -bis(4-dimethylaminophenyl)ethanol (CAS#3 3 905 -89-4) having a chemical structure: O H3C OH CH3 l,l-bis(4-dimethylaminophenyl)ethylene (CAS# 22057-85-8) having a chemical structure : H3C\ /N \ 10 “ac Q s , (It is believed that this compound is converted by proton addition to the methylene group into the same bleachable dye cation as provided by the preceding structure.) bis(4-dimethylamino)-2-methylphenyl)methanol) l5 (CAS#4300 1 -46-3) having a chemical structure: bis(3 -bromo-4-dimethylaminophenyl)methanol having a chemical structure: Me2N NMe2 9 Br Br C H3C OH CH3 N-[bis(4-dimethylaminophenyl)methyl]morpholine (CAS#2l295-86-3) having a 20 chemical structure: 10 WO 2008/030903 PCT/US2007/077679 (E: Me 2 N H NMe 2 N-[bis[4-(diniethy1an1ino)phenyl]n1ethy1]-N’-n-butyl-urea (CAS#27086-41-5) having a H30‘ H ’CH3 /N O W H C HN CH 3 3 chemical structure: 0 HN\/V N- [bis [4-(din1ethy1an1ino)pheny1]methyl]-N'-(4-ethoxyphenyl)-urea (CAS#3 7171-10-1) having a chemical structure: NMe2 O /©i H_NH_ ii_ N Me2N OEt I N- [bis [4-(diniethylan1ino)pheny1]n1ethy1] -N'-(4-niethylphenyl)-urea (CAS#123 344-13 -8) having a chemical structure: NMe2 O /@7 H_NH_g_NH Me2N M e .~' [retrieved on 2008-02-04] page 9 K. HUNGER: "lndustriai Dyes - Chemistry, Properties, Appiications" 2003, WILEY , XP002467701 pages 63-64, paragraph 2.6.3 US 4 495 509 A (CHAO HUNG-YA [US]) 22 January 1985 (1985-01-22) abstract coiumn 5 Fonn PCT/ISA/210 (continuation of second sheet) (April 2005) page 2 of 2 INTERNATIONAL SEARCH REPORT Information on patent family members EP 1580200 A 28-09-2005 2003280712 1714107 2004041876 3852395 2004155905 20050084643 2004254272 NO 0230363 A 18-04-2002 2423594 01979467 1326573 2214984 2004510796 200400624 6528555 US 4495509 A 22-01-1985 559596 2374784 8402809 1208503 3464855 78084 0128700 8602435 840561 81888 56349 1507029 59228931 63056818 160617 842329 206653 78337 8309184 Form PCT/ISA/210 (patent fami|y annex) (April 2005) International application No PCT/US2007/077679 Patent document Publication Patent family cited in search report date member(s) Publication date 07-06-2004 28-12-2005 21-05-2004 29-11-2006 03-06-2004 26-08-2005 16-12-2004 18-04-2002 15-07-2004 16-07-2003 01-10-2004 08-04-2004 21-05-2004 04-03-2003 12-03-1987 13-12-1984 21-05-1985 29-07-1986 27-08-1987 10-12-1984 19-12-1984 16-03-1986 10-12-1984 12-12-1984 03-07-1991 13-07-1989 22-12-1984 09-11-1988 28-03-1990 10-12-1984 11-06-1986 01-04-1984 25-07-1984