Primer compositions for use with cyanoacrylate compositions
The use of a primer composition with triarylphosphine and tetraalkyl alkylene diamine enhances cyanoacrylate adhesive bonding to plastics, achieving substantial strength improvements on polypropylene and polycarbonate substrates.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- HENKEL KGAA
- Filing Date
- 2025-10-01
- Publication Date
- 2026-05-15
AI Technical Summary
Existing cyanoacrylate adhesive compositions face challenges in effectively bonding to hard-to-bond surfaces such as plastics, necessitating the development of effective primers or activators that enhance adhesion across various substrate materials.
A primer composition comprising triarylphosphine and tetraalkyl alkylene diamine is used to improve the bonding of cyanoacrylate adhesives to plastic substrates, enhancing adhesion strength through a combination of these components.
The primer composition significantly increases adhesive bond strength on plastic substrates, demonstrating up to three times the strength on polypropylene and at least 10% on polycarbonate compared to compositions without the primer, after curing for 24 hours at room temperature.
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Abstract
Description
PRIMER COMPOSITIONS FOR USE WITH CYANOACRYLATE COMPOSITIONSBACKGROUNDField
[0001] This invention relates to primer compositions for use with cyanoacrylate compositions, particularly to bond plastics substrates. The primer compositions include the combination of triarylphosphine, and tetraalkyl alkylene diamine.Brief Description of Related Technology
[0002] Cyanoacrylate adhesive compositions are well known, and widely used as quick setting, instant adhesives with a wide variety of uses. See H. V. Coover, D. W. Dreifus and J. T. O'Connor, “Cyanoacrylate Adhesives” in Handbook of Adhesives, 27, 463-77, I. Skeist, ed., Van Nostrand Reinhold, New York, 3rd ed. (1990). See also G. H. Millet, “Cyanoacrylate Adhesives” in Structural Adhesives: Chemistry and Technology, S. R. Hartshorn, ed., Pienun Press, New York, p. 249-307 (1986).
[0003] Despite their fast-acting nature, sometimes cyanoacrylate adhesive compositions could benefit from the assistance of a primer or activator, particularly on hard to bond surfaces, such as plastic substrates. Application onto the surface of such a substrate of a destabilizing chemical, such as a nitrogen containing compound, is used to prime or activate the surface.
[0004] Notwithstanding the state of the art and the efforts to date to identify and evaluate any such primers or activators for cyanoacrylate compositions, there remains a long felt, yet unmet, need to provide such alternatives that perform well irrespective of the materials from which the substrate(s) are constructed. That need has been outstanding until now.SUMMARY
[0005] This invention in one aspect is directed to a composition comprising or consisting of the combination of triarylphosphine, and tetraalkyl alkylene diamine.
[0006] In another aspect, provided herein is a kit comprising: A. a cyanoacrylate component; and B. a composition as so-described.
[0007] In yet another aspect, provided herein is a method of applying a primer composition to a substrate formed of a plastic material, steps of which comprise Providing a primer composition comprising the combination of triarylphosphine and tetraalkyl alkylene diamine, wherein the primer composition is housed within a container having an end dimensioned and disposed to dispense the primer composition therefrom, wherein the end is fitted with a felt-tip, a brush, or a spray nozzle through which the primer composition may flow or from which the primer composition may be applied; Providing at least one substrate onto which the primer composition may be received on at least a portion of a surface thereof; Dispensing the primer composition from the dispensing end of the container onto at least a portion of the surface of the substrate.
[0008] In still yet another aspect, provided herein is a method of bonding a first substrate formed of a plastic material to a second substrate, steps of which comprise: Providing a first substrate and a second substrate; Applying onto at least a portion of a bonding surface of at least one of the first or the second substrate a composition comprising the combination of: triarylphosphine and tetraalkyl alkylene diamine; Providing onto at least a portion of a bonding surface of at least one of the first or the second substrate a cyanoacrylate composition; and Mating the first and the second substrate for a time sufficient to form an adhesive bond therebetween.
[0009] In a further aspect, provided herein is a use of a composition comprising the combination of triarylphosphine and tetraalkyl alkylene diamine as a primer for substrates constructed of a plastic material to be adhesively bonded with a cyanoacrylate composition.
[0010] The invention will be more fully understood by a reading of the section entitled “Detailed Description”, which follows.DETAILED DESCRIPTION
[0011] As noted above, this invention in one aspect is directed to a composition comprising or consisting of the combination of triarylphosphine, and tetraalkyl alkylene diamine. This composition is particularly useful as a primer for plastics bonding using a cyanoacrylate adhesive.
[0012] For instance, the triarylphosphine may be triphenylphosphine.
[0013] The triarylphosphine may be present in an amount of about 0.05% by weight to about 0.3% by weight, based on the total amount of the composition, such as in an amount of about 0.06% by weight to about 0.1% by weight, based on the total amount of the composition.
[0014] The tetraalkyl alkylene diamine may be tetraethyl ethylene diamine.
[0015] The tetraalkyl alkylene diamine may be present in an amount of about 0.1 % by weight to about 1 .0% by weight, based on the total amount of the composition, such as in an amount of about 0.2% by weight to about 0.7% by weight, based on the total amount of the composition.
[0016] The composition may further comprise a solvent, such as one selected from liquid alkanes, liquid alcohols, liquid ketones, liquid esters, liquid ethers, and combinations thereof.
[0017] The liquid alkane solvents may be selected from butanes, pentanes, hexanes, heptanes, octanes, nonanes and decanes, and combinations thereof.
[0018] The liquid alcohol solvents may be selected from methanol, ethanol, propanols, butanols, pentanols, hexanols, heptanols, octanols, nonanols and decanols, and combinations thereof.
[0019] The liquid ketone solvents may be selected from propanones, butanones, pentanones, hexanones, heptanones, octanones, nonanones and decanones, and combinations thereof.
[0020] The liquid ester solvents may be selected from alkyl acetates, alkyl propionoates, alkyl butanoates and combinations thereof, such as methyl acetate, methyl propionates, methyl butanates, ethyl acetate, ethyl propionates, ethyl butanates, propyl acetates, propyl propionates, propyl butanates, butyl acetates, butyl propionates, butyl butanates and combinations thereof.
[0021] The liquid ether solvents may be selected from dialkyl ethers, alkyl-alkoxy ethers, dialkoxy ethers, diaryl ethers, al kyl-ary I ethers, and combinations thereof.
[0022] In another aspect, provided herein is a kit comprising: A. a cyanoacrylate component; and B. a composition as so-described.
[0023] In yet another aspect, provided herein is a method of applying a primer composition to a substrate formed of a plastic material, steps of which comprise Providing a primer composition comprising the combination of Triarylphosphine, and Tetraalkyl alkylene diamine, wherein the primer composition is housed within a container having an end dimensioned and disposed to dispense the primer composition therefrom, wherein the end is fitted with a felt-tip, a brush, or a spray nozzle through which the primer composition may flow or from which the primer composition may be applied; Providing at least one substrate onto which the primer composition may be received on at least a portion of a surface thereof; Dispensing the primer composition from the dispensing end of the container onto at least a portion of the surface of the substrate.
[0024] In still yet another aspect, provided herein is a method of bonding a first substrate formed of a plastic material to a second substrate, steps of which comprise: Providing a first substrate and a second substrate; Applying onto at least a portion of a bonding surface of at least one of the first or the second substrate a composition comprising the combination of: Triarylphosphine, and Tetraalkyl alkylene diamine; Providing onto at least a portion of a bonding surface of at least one of the first or the second substrate a cyanoacrylate composition; and Mating the first and the second substrate for a time sufficient to form an adhesive bond therebetween.
[0025] In this aspect, at least one of, and desirably each of, the first or the second substrates is formed from a plastic material selected from for example ABS, PC, PLA, PC / ABS, HDPE, LDPE, PP, PPSU and PEI, acetal, PEEK, nylon, and PTFE. The inventive primer composition is particularly useful in assisting cyanoacrylate compositions to bond together polyolefin substrates, such as PE-or PP.
[0026] In this aspect, the adhesive bond that forms demonstrates a significant increase-(up to 3 times the strength) on PP lapshear substrates after curing for about 24 hours at about room temperature than compared to PP lapshear substrates having not been applied a composition comprising the combination of triarylphosphine and tetraalkyl alkylene diamine.
[0027] The so-formed adhesive bond demonstrates at least about a 10% increase in strength on PC lapshear substrates after curing for about 24 hours at about roomtemperature than compared to PC lapshear substrates having not been applied a composition comprising the combination of triarylphosphine and tetraalkyl alkylene diamine.
[0028] The cyanoacrylate component includes cyanoacrylate monomers which may be chosen with a raft of substituents, such as those represented by H2C=C(CN) — COOR, where R is selected from C1-15 alkyl, alkoxyalkyl, cycloalkyl, alkenyl, aralkyl, aryl, allyl and haloalkyl groups. Desirably, the cyanoacrylate monomer is selected from methyl cyanoacrylate, ethyl-2-cyanoacrylate, propyl cyanoacrylates, butyl cyanoacrylates (such as n-butyl-2-cyanoacrylate), octyl cyanoacrylates, allyl cyanoacrylate, p-methoxyethyl cyanoacrylate and combinations thereof. Particularly desirable ones are ethyl-2 -cyanoacrylate and p-methoxyethyl cyanoacrylate. Also blends of allyl cyanoacrylate and ethyl-2-cyanoacrylate benefit from use of the inventive primer compositions.
[0029] The cyanoacrylate component should be included in the composition in an amount within the range of from about 50% to about 99.98% by weight, with the range of about 90% to about 99% by weight being desirable, and about 95% by weight of the total composition being particularly desirable.
[0030] The invention will be further illustrated by the examples which follow.EXAMPLES
[0031] Unless otherwise specified, all adhesive samples were prepared using ethyl cyanoacrylate (“ECA”) or beta-methoxyethyl cyanoacrylate (“BMeOCA”), or either as used in a commercial product, such as LOCTITE Power Flex, LOCTITE Precision, LOCTITE Pure Gel, LOCTITE 60s Universal Glue, or LOCTITE 460.
[0032] The primer compositions were selected from the commercially available products LOCTITE A (TEEDA in a solvent), LOCTITE B (an aliphatic amine in isopropyl acetate), LOCTITE C (an aliphatic amine in n-heptane), Competitor 1 (believed to contain heptane, 3-ethyl pentane, methyl cyclohexane, triethylenediamine, and TPP) or Competitor 2 (believed to contain isopropanol, ethyl acetate, 2-methyl-1 -pentene, toluene, 2-butoxyethanol, butylated hydroxy anisole, 2,4,6- tris(dimethylaminomethyl)phenol and a C13 amine).
[0033] In a first series of evaluations, an ethyl cyanoacrylate composition was used to bond together polyethylene substrates and polypropylene substrates, using no primer and various combinations of concentrations of TPP and TEEDA in heptane solvent.
[0034] Table 1 below shows the concentrations of TPP and TEEDA used in heptane and the lap shear bond strength in N / mm2after 24 hours of room temperature cure.Table 1 : Heptane-based TPP / TEEDA Primer Formulations A in terms of bond strength after 24 hour room temperature cure (N / mm2) on PP and PE with LOCTITE Superglue
[0035] It is clear from results in Table 1 that the use of a primer improves the bond strengths of a cyanoacrylate composition adhering together the polyolefin substrates over no use of a primer at all.
[0036] It was subsequently observed that while higher levels of TPP seemingly improved performance on polyethylene and polypropylene, such levels detracted from performance on other substrates, such as polycarbonate.
[0037] In a second series of evaluations, commercially available cyanoacrylate compositions containing either ethyl cyanoacrylate (LOCTITE POWER FLEX, LOCTITE 60 sec UNIVERSAL GLUE and LOCTITE PRECISION) or p-methoxyethyl cyanoacrylate (LOCTITE PURE GEL or LOCTITE 460) were used to bond together polypropylene substrates, using no primer, a commercially available primer (LOCTITE Primer A, 0.22% TEEDA in heptane) and various combinations of concentrations of TPP and TEEDA in heptane solvent.
[0038] Table 2 below shows the concentrations of TPP and TEEDA used in heptane in comparison with no primer and LOCTITE Primer A, and the lap shear bond strength on polypropylene in N / mm2after 24 hours of room temperature cure.Table 2: Heptane-based TPP / TEEDA Primer Formulations compared to LOCTITE Primer A in terms of bond strength after 24 hour room temperature cure (N / mm2) on PP with a range of commercially available LOCTITE products
[0039] Table 2 shows good performance for the TPP / TEEDA combination on polypropylene substrates for ethyl cyanoacrylate compositions as well as p- methoxyethyl cyanoacrylate compositions, compared with no primer and the commercially available LOCTITE Primer A.
[0040] In a third series of evaluations, commercially available primers, Competitor 1 (believed to contain heptane, 3-ethyl pentane, methyl cyclohexane, triethylenediamineand TPP) and Competitor 2 (believed to contain isopropanol, ethyl acetate, 2-methyl-1- pentene, toluene, 2-butoxyethanol, butylated hydroxy anisol, 2,4,6- tris(dimethylaminomethyl)phenol and a C13 amine), were evaluated against the combination of 0.075% TPP / 0.5% TEEDA in heptane (Prototype A2) on each of polypropylene and polyethylene substrates.
[0041] Table 3 below shows the performance of these three primers on the noted substrates together with an ethyl cyanoacrylate composition in terms of lap shear bond strength in N / mm2after 24 hours of room temperature cure.Table 3: Bond strength after 24 hours at room temperature cure (N / mm2) of Prototype A on PE and PP versus Competitor samples on PP with ECA
[0042] In a fourth series of evaluations, three different cyanoacrylate compositions (ECA, BMeOCA and an Allyl CA / ECA blend) were used to bond together polyethylene substrates and polypropylene substrates, using no primer, LOCTITE Primer B, LOCTITE Primer C and primer compositions to include TPP at a level of 0.2% and the combination of TPP at a level of 0.075% and TEEDA at a level of 0.5%, each by weight in a variety of solvents. The solvents as well as the lap shear bond strength performance after application and 24 hour of room temperature cure are shown below in Tables 4 and 5.Table 4: Effect of Solvent on Bond Strength after 24 hour room temperature cure (N / mm2) on PETable 5: Effect of Solvent on Bond Strength after 24 hour room temperature cure (N / mm2) on PP
[0043] It is clear from results in Tables 4 and 5 that the use of the composition comprising TPP at a level of 0.075% by weight and TEEDA at a level of 0.5% by weight in various solvents as a primer improved the bond strengths across all cyanoacrylatecompositions (and particularly ECA) over no use of a primer at all, and in some instances over the other commercially available primer compositions.
[0044] In a fifth series of evaluations, an ECA based LOCTITE product was used to bond together PE and PP substrates, using the combination of TPP at a level of 0.075% and TEEDA at a level of 0.5%, each by weight in a variety of solvents (Prototypes E - H). The solvents as well as the lap shear bond strength performance N / mm2after application and 24 hour of room temperature cure are shown below in Table 6.Table 6:TPP / TEEDA based Prototypes in Various Solvents on Bond Strength after 24 hour room temperature cure (N / mm2) on PE and PP, with ECA Loctite Product
[0045] The results in Table 6 show the use of the combination of TPP at a level of 0.075% by weight and TEEDA at a level of 0.5% by weight in the listed solvents heptane as a primer together with ECA provide improved the bond strengths adhering together the polyolefin substrates over no use of a primer at all and TPP alone.
[0046] In Table 7 below, a series of cyanoacrylate compositions were evaluated with a primer comprising the combination of TPP at a level of 0.075% by weight and TEEDA at a level of 0.5% by weight in heptane to bond together PC substrates.Table 7
[0047] Apart from LOCTITE Superglue Professional, which showed increased bond strength over the other three compositions but substrate failure when comparisons of with and without primer were attempted, the remaining three cyanoacrylate compositions showed increases in bond strength ranging from 13% to 39%.
Claims
What is Claimed is:1 . A composition comprising the combination of:Triarylphosphine, andTetraalkyl alkylene diamine.
2. The composition of Claim 1 , wherein the triarylphosphine is triphenylphosphine.
3. The composition of Claim 1 or Claim 2, wherein the tetraalkyl alkylene diamine is tetraethyl ethylene diamine.
4. The composition of any of the preceding claims, wherein the triarylphosphine is present in an amount of about 0.05% by weight to about 0.3% by weight, based on the total amount of the composition.
5. The composition of any of the preceding claims, wherein the triarylphosphine is present in an amount of about 0.06% by weight to about 0.1 % by weight, based on the total amount of the composition.
6. The composition of any of the preceding claims, wherein the tetraalkyl alkylene diamine is present in an amount of about 0.1 % by weight to about 1 .0% by weight, based on the total amount of the composition.
7. The composition of any of the preceding claims, wherein the tetraalkyl alkylene diamine is present in an amount of about 0.2% by weight to about 0.7% by weight, based on the total amount of the composition.
8. The composition of any of the preceding claims, further comprising a solvent.
9. The composition of any of Claims 1 to 7, further comprising a solvent selected from the group consisting of liquid alkanes, liquid alcohols, liquid ketones, liquid esters, liquid ethers, and combinations thereof.
10. The composition of Claim 9, wherein the liquid alkanes are selected from the group consisting of butanes, pentanes, hexanes, heptanes, octanes, nonanes and decanes, and combinations thereof.11 . The composition of Claim 9 or Claim 10, wherein the liquid alcohols are selected from the group consisting of methanol, ethanol, propanols, butanols,pentanols, hexanols, heptanols, octanols, nonanols and decanols, and combinations thereof.
12. The composition of any of Claims 9 to 11 , wherein the liquid ketones are selected from the group consisting of propanones, butanones, pentanones, hexanones, heptanones, octanones, nonanones and decanones, and combinations thereof.
13. The composition of any of Claims 9 to 12, wherein the liquid esters are selected from the group consisting of alkyl acetates, alkyl propionoates, alkyl butanoates and combinations thereof.
14. The composition of any of Claims 9 to 13, wherein the alkyl acetates, alkyl propionates, and alkyl butanoates are selected from the group consisting of methyl acetate, methyl propionates, methyl butanates, ethyl acetate, ethyl propionates, ethyl butanates, propyl acetates, propyl propionates, propyl butanates, butyl acetates, butyl propionates, butyl butanates and combinations thereof.
15. The composition of any of Claims 9 to 14, wherein the liquid ethers are selected from the group consisting of dialkyl ethers, alkyl-alkoxy ethers, dialkoxy ethers, diaryl ethers, alkyl-ary I ethers, and combinations thereof.
16. A composition consisting of:Triarylphosphine, andTetraalkyl alkylene diamine.
17. The composition of Claim 16, further comprising a solvent.
18. The composition of Claim 17, further comprising a solvent selected from the group consisting of liquid alkanes, liquid alcohols, liquid ketones, liquid esters, liquid ethers, and combinations thereof.
19. A composition comprising the combination of:Triphenylphosphine present in an amount of about 0.5% by weight, based on the total amount of the composition, andTetraethyl ethylene diamine present in an amount of about 0.075% by weight, based on the total amount of the composition.
20. A kit comprising:A. a cyanoacrylate component; andB. a composition of any of the preceding claims.21 . A method of applying a primer composition to a substrate formed of a plastic material, steps of which compriseProviding a primer composition comprising the combination of: Triarylphosphine, and Tetraalkyl alkylene diamine, wherein the primer composition is housed within a container having an end dimensioned and disposed to dispense the primer composition therefrom, wherein the end is fitted with a felt-tip, a brush, or a spray nozzle through which the primer composition may flow or from which the primer composition may be applied;Providing at least one substrate onto which the primer composition may be received on at least a portion of a surface thereof; andDispensing the primer composition from the dispensing end of the container onto at least a portion of the surface of the substrate.
22. A method of bonding a first substrate formed of a plastic material to a second substrate, steps of which compriseProviding a first substrate and a second substrate;Applying onto at least a portion of a bonding surface of at least one of the first or the second substrate a composition comprising the combination of:Triarylphosphine, andTetraalkyl alkylene diamine;Providing onto at least a portion of a bonding surface of at least one of the first or the second substrate a cyanoacrylate composition; andMating the first and the second substrate for a time sufficient to form an adhesive bond therebetween.
23. The method of Claim 22, wherein at least one of the first or the second substrates is formed from a plastic material selected from the group consisting of ABS, PC, PLA, PC / ABS, HDPE, LDPE, PP, PPSU, PEI, acetal, PEEK, nylon, and PTFE.
24. The method of Claim 22, wherein each of the first and the second substrates are formed from a plastic material selected from the group consisting of ABS, PC, PLA, PC / ABS, HDPE, LDPE, PP, PPSU, PEI, acetal, PEEK, nylon, and PTFE.
25. The method of any of Claims 22 to 24, wherein the adhesive bond that forms demonstrates at least 3 times the strength on PP lapshear substrates after curing for about 24 hours at about room temperature than compared to PP lapshear substrates having not been applied a composition comprising the combination of Triarylphosphine and Tetraalkyl alkylene diamine.
26. The method of any of Claims 22 to 25, wherein the adhesive bond that forms demonstrates at least about a 10% increase in strength on PC lapshear substrates after curing for about 24 hours at about room temperature than compared to PC lapshear substrates having not been applied a composition comprising the combination of Triarylphosphine and Tetraalkyl alkylene diamine.
27. Use of a composition comprising the combination of Triarylphosphine and Tetraalkyl alkylene diamine as a primer for substrates constructed of a plastic material to be adhesively bonded with a cyanoacrylate composition.