Cyanoacrylate composition

Abstract

The present invention provides a cyanoacrylate composition that improves high-temperature strength performance while maintaining a desirable level of heat resistance. [Solution] A cyanoacrylate composition is provided, comprising (a) a cyanoacrylate component comprising a combination of (i) allyl cyanoacrylate and (ii) another cyanoacrylate selected from the group consisting of methyl cyanoacrylate, ethyl-2-cyanoacrylate, propyl cyanoacrylate, butyl cyanoacrylate, octyl cyanoacrylate and β-methoxyethyl cyanoacrylate, (b) fluorobenzonitrile, (c) hydrogenated aromatic anhydride, and (d) a reinforcing component.

Description

[Technical Field]

[0001] The present invention relates to a cyanoacrylate-containing composition that, upon curing, improves high-temperature strength performance without impairing heat resistance. [Background technology]

[0002] Cyanoacrylate adhesive compositions are well known and widely used as rapid-curing instant adhesives for a variety of applications. See Adhesives Handbook, Vol. 27, pp. 463-77, "Cyanoacrylate Adhesives" by H.V. Coover, D.W. Dreyfus and J.T. O'Connor, edited by I. Skist, Van Nostrand-Reinhold, New York, 3rd edition (1990). See also "Cyanoacrylate Adhesives" in Structural Adhesives by GH.Millet: Chemistry and Technology, edited by S.R. Hartshorne, Plenum Press, New York, pp. 249-307 (1986).

[0003] Efforts have been made to improve the thermal durability of cured products of cyanoacrylate compositions, particularly when exposed to high-temperature conditions, such as 120°C, 150°C, and 180°C. Because cured products are inherently thermoplastic, they tend to soften as the temperature rises, and above the material's Tg, the cured products begin to flow. As the temperature rises further, degradation begins, and the physical properties deteriorate. As a result, the commercial applications of cyanoacrylates exposed to high-temperature conditions have proven difficult to handle and limited.

[0004] Many attempts have been made in the past to improve this situation.

[0005] Additives such as heat-resistance imparters are known to be used with cyanoacrylates, and most of these involve additive chemistry, although some involve the use of allyl cyanoacrylate and / or bis-cyanoacrylate. For example, U.S. Patent No. 5,328,944 (ATALWALA) (Improved cyanoacrylate monomer adhesive formulation, the formulation comprising an amount effective in enhancing the heat resistance of cured polymers of sulfur-containing compounds of specific chemical formulas, including anhydrous sulfites, sulfoxides, sulfites, sulfonates, methanesulfonates, p-toluenesulfonates, sulfinates and cyclic sulfinates); U.S. Patent No. 5,288,794 (ATALWALA) (Improved cyanoacrylate monomer adhesive formulation, the formulation comprising an amount effective in enhancing the heat resistance of cured polymers of mono, poly, or heteroaromatic compounds characterized by at least three substitutions on their aromatic ring, where two or more substitutions are electron-withdrawing groups, and an example of an aromatic compound is 2,4-dinit See also U.S. Patent No. 5,424,343 (ATALWALA) (a polymer-curable cyanoacrylate monomer adhesive formulation comprising a cyanoacrylate monomer and a naphthosultone compound substituted with at least one electron-withdrawing group as strong as nitro, in an amount effective in improving the heat resistance of the cured polymer).

[0006] Furthermore, it is known that carboxylic acids and their anhydrides are used in cyanoacrylate compositions to improve heat resistance and moisture resistance. See, for example, U.S. Patent No. 3,832,334 (addition of maleic anhydride, which has been reported to produce a cyanoacrylate adhesive with improved heat resistance (during curing) while maintaining a fast curing rate); U.S. Patent No. 4,196,271 (tri, tetra and higher carboxylic acids or their anhydrides, which have been reported to be useful for improving the heat resistance of cured cyanoacrylate adhesives); U.S. Patent No. 4,450,265 (phthalic anhydride, which improves the heat resistance of cyanoacrylate adhesives); and U.S. Patent No. 4,532,293 (benzophenonetetracarboxylic acid or its anhydride, which has excellent heat resistance).

[0007] It is also known that rubber or elastomers are used as additives to strengthen cyanoacrylate. See, for example, U.S. Patent No. 4,440,910 (O'Connor) (Use of certain organic copolymers of lower alkene monomers with (i) acrylic acid esters, (ii) methacrylic acid esters, or (iii) elastomers, i.e., vinyl acetate as a reinforcing additive having rubbery properties); U.S. Patent No. 9,944,830 (Ataruwara) (Rubber-reinforced cyanoacrylate, the rubber reinforcing agent essentially consisting of (a) a reaction product of a combination of monomers having ethylene, methyl acrylate, and carboxylic acid curing sites, (b) an ethylene-methyl acrylate dipolymer, and a combination of (a) and (b), substantially free of release agents, antioxidants, stearic acid and / or polyethylene glycol ether wax, with further additions of N,N'-meth-phenylene bismaleimide and phthalic anhydride); and U.S. Patent No. 5,536,799 (Takahashi) (Dipentaerythritol ester in cyanoacrylate for improving thermal aging).

[0008] Recently, Henkel Adhesive Technologies has invented several techniques to address the improvement of the heat resistance of cured cyanoacrylate compositions. One concerns cyanoacrylate adhesive compositions comprising (a) a monofunctional cyanoacrylate component (e.g., allyl-2-cyanoacrylate) and (b) a polyfunctional cyanoacrylate component (e.g., bis-cyanoacrylate). See U.S. Patent Application Publication No. 2017 / 0233618. Another concerns cyanoacrylate-containing compositions comprising, in addition to cyanoacrylate components, hydrogenated phthalic anhydride and optionally benzonitrile. See U.S. Patent No. 9,120,957 (Heddaman). Another example is U.S. Patent Application Publication No. 2018 / 0251659 (Tally), which broadly provides a cyanoacrylate composition that, upon curing, provides improved thermal and humidity performance through a combination of (a) a cyanoacrylate component, (b) a reaction product of a combination of (i) ethylene, methyl acrylate and monomers having carboxylic acid curing sites, (ii) a dipolymer of ethylene and methyl acrylate and a rubber reinforcing agent consisting of a combination of (i) and (ii), (c) a component containing at least two (meth)acrylate functional groups, and (d) an anhydride component. Yet another example is U.S. Patent Application Publication No. 2020 / 0102480 (Tally), which provides (a) a cyanoacrylate component, (b) a reinforcing agent containing a copolymer of polyethylene and polyvinyl acetate, (c) a component having at least two (meth)acrylate functional groups, (d) a benzonitrile component, and (e) an anhydride component.

[0009] Despite these efforts, there has been a persistent need to achieve more robust high-temperature strength performance without compromising the heat resistance of cured cyanoacrylate compositions. Therefore, providing such a solution to a long-recognized but unmet need would be highly advantageous. [Overview of the Initiative] [Means for solving the problem]

[0010] The present invention provides such a solution.

[0011] By navigating through the intersection of known technologies, the inventors have surprisingly discovered that by removing additives that contribute to heat resistance and adding a group of other additives, it is possible to improve high-temperature strength performance while maintaining a desirable level of heat resistance.

[0012] Therefore, the present invention provides a cyanoacrylate composition that, upon curing, exhibits improved high-temperature strength performance without impairing heat resistance. The composition comprises (a) a cyanoacrylate component including a combination of (i) allyl cyanoacrylate and (ii) another cyanoacrylate selected from the group consisting of methyl cyanoacrylate, ethyl-2-cyanoacrylate, propyl cyanoacrylate, butyl cyanoacrylate, octyl cyanoacrylate and β-methoxyethyl cyanoacrylate, (b) fluorobenzonitrile, (c) hydrogenated aromatic anhydride, and (d) ethylene vinyl acetate copolymer and / or polymers of monomers having ethylene, methyl acrylate and carboxylic acid curing sites.

[0013] Importantly, when a cyanoacrylate composition is devoid of hexanediol diacrylate, which contributes to the heat resistance of the cyanoacrylate composition (as described in Publication 659), not only is the high-temperature strength performance improved, but the heat resistance is also maintained.

[0014] Furthermore, the reinforcing component must be present in an amount of 8% by weight or less in order to improve high-temperature strength performance without impairing heat resistance. If present in an amount exceeding 8% by weight, no improvement in high-temperature strength performance and / or maintenance of heat resistance will be observed.

[0015] Unless otherwise specified, weight percentages refer to weights based on the total weight of the composition.

[0016] The observed performance improvement may be explained by the cured product of the cyanoacrylate composition exhibiting the following physical properties: (a) approximately 18 N / mm² 2 The above initial adhesive strength; (b) The adhesive strength after about 1000 hours at a temperature of about 135°C is about 7 N / mm 2 or more; and (c) The high-temperature strength at about 135°C is about 3 N / mm 2 or more.

[0017] The present invention also targets a method for joining two substrate surfaces, which includes applying the above composition to at least one of the substrate surfaces and then bringing the substrate surfaces together.

[0018] Furthermore, the present invention targets the cured product of the composition of the present invention.

[0019] Also, the present invention targets a method for preparing the composition of the present invention.

[0020] The present invention will be more fully understood by reading the section entitled "Detailed Description" below.

Brief Description of the Drawings

[0021] [Figure 1] Figure 1 shows the initial tensile strength of the cured products of the cyanoacrylate formulations labeled with sample numbers 1 to 6 for a grit-blasted mild steel (GBMS) lap shear substrate. [Figure 2] Figure 2 shows the tensile strength performance of the cured products of sample numbers 1 to 6 on a GBMS lap shear substrate after thermal aging at 120°C, 135°C, and 150°C for 1000 hours. [Figure 3] Figure 3 shows the high-temperature strength performance of the cured products of sample numbers 1 to 6 on a GBMS lap shear substrate at 120°C, 135°C, and  150°C.

Modes for Carrying Out the Invention

[0022] As described above, the present invention relates to a cyanoacrylate composition that, upon curing, exhibits improved high-temperature strength performance without impairing heat resistance. The composition comprises (a) a cyanoacrylate component including a combination of (i) allyl cyanoacrylate and (ii) another cyanoacrylate selected from the group consisting of methyl cyanoacrylate, ethyl-2-cyanoacrylate, propyl cyanoacrylate, butyl cyanoacrylate, octyl cyanoacrylate and β-methoxyethyl cyanoacrylate, (b) fluorobenzonitrile, (c) hydrogenated aromatic anhydride, and (d) an ethylene vinyl acetate copolymer and / or a polymer of monomers having ethylene, methyl acrylate and carboxylic acid curing sites.

[0023] Importantly, when a cyanoacrylate composition is devoid of hexanediol diacrylate, which contributes to the heat resistance of the cyanoacrylate composition (as described in Publication 659), not only is the high-temperature strength performance improved, but the heat resistance is also maintained.

[0024] Furthermore, the reinforcing component must be present in an amount of 8% by weight or less in order to improve high-temperature strength performance without impairing heat resistance. If it is present in an amount exceeding 8% by weight, no improvement in high-temperature strength performance and / or maintenance of heat resistance will be observed, as will be explained in detail later.

[0025] High-temperature conditions for evaluating high-temperature strength performance and heat resistance performance include temperatures of approximately 120°C or higher, such as approximately 135°C and approximately 150°C.

[0026] High-temperature strength is measured according to ISO 4587, and lap shear strength is measured in an oven set to a specified temperature after the adhesive test specimen has been cured at room temperature for 24 hours.

[0027] Heat resistance or durability is measured according to ISO 4587, and the wrap shear strength is measured at room temperature after the adhesive test specimen is cured at room temperature for 24 hours and aged for 1000 hours in an oven at a specified temperature prior to the test.

[0028] The cyanoacrylate components include combinations of (i) allyl cyanoacrylate and (ii) another cyanoacrylate selected from methyl cyanoacrylate, ethyl-2-cyanoacrylate, propyl cyanoacrylate, butyl cyanoacrylate, octyl cyanoacrylate, and β-methoxyethyl cyanoacrylate. Particularly preferred combinations are allyl cyanoacrylate and ethyl-2-cyanoacrylate.

[0029] The cyanoacrylate component should be included in the composition in an amount ranging from approximately 50% to approximately 99.98% by weight, preferably in the range of approximately 80% to approximately 96% by weight of the total composition.

[0030] The weight ratio of allyl cyanoacrylate to other cyanoacrylates should be in the range of approximately 4:1 to approximately 1:4, for example, approximately 2:1 to approximately 1:2, preferably approximately 1:1.

[0031] Fluorobenzonitrile may be selected from one or more of the following: pentafluoronitrobenzene; pentafluorobenzonitrile; α,α,α-2-tetrafluoro-p-tolunitrile; and tetrafluoroisophthalonitrile.

[0032] Fluorobenzonitrile should be present in an amount of approximately 5% by weight, such as approximately 0.01% to 3% by weight, or approximately 0.1% to 1% by weight, with approximately 0.5% by weight being particularly desirable.

[0033] The hydrogenated aromatic anhydride should be a hydrogenated phthalic anhydride such as 3,4,5,6-tetrahydrophthalic anhydride. However, its isomers and partially hydrogenated forms of phthalic anhydride may also be used.

[0034] Hydrogenated phthalic anhydride should be used in an amount of approximately 0.5% by weight, preferably in the range of approximately 0.01% to approximately 0.2% by weight, and more preferably in the range of approximately 0.05% to approximately 0.1% by weight.

[0035] The reinforcing component may be selected from one of several possibilities, but the amount of the reinforcing component used in the cyanoacrylate composition should be 8% by weight or less.

[0036] One such possibility is an ethylene vinyl acetate copolymer containing 30% to 95% by weight of vinyl acetate, for example, about 50% to about 90% by weight of vinyl acetate, preferably about 90% by weight of vinyl acetate, based on the total weight of the copolymer.

[0037] Polyethylene and polyvinyl acetate copolymers, sold by Lanxess under the trade names Levamelt or Levaprene, are particularly desirable for use herein.

[0038] Various copolymers under the Levamelt brand are available, such as Levamelt 400, Levamelt 600, and Levamelt 900. These copolymers differ in the amount of vinyl acetate present. For example, Levamelt 400 represents an ethylene-vinyl acetate copolymer containing 40% by weight of vinyl acetate, based on the total weight of the copolymer.

[0039] The copolymer may be an ethylene-vinyl acetate copolymer containing about 30% by weight to about 95% by weight of vinyl acetate based on the total weight of the copolymer. For example, the copolymer may contain about 50% to about 95% by weight of vinyl acetate, for example, about 70% to about 95% by weight, preferably about 90% by weight, based on the total weight of the copolymer.

[0040] Particularly desirable copolymers include polyethylene and polyvinyl acetate, with vinyl acetate present in an amount of 90% by weight based on the total weight of the copolymer.

[0041] The structural representation of the copolymer is shown below:

[0042] [ka]

[0043] Another such possibility is a reaction product of a combination of monomers having ethylene, methyl acrylate, and carboxylic acid curing sites. For example, ethylene acrylic elastomers available from DuPont under the trade names Bamak, such as Bamak N123 and Bamak B-124, may be used. Bamak N123 and Bamak B-124 are reported by DuPont as masterbatches of ethylene / acrylic elastomers. DuPont's Bamak G is a similar copolymer, but does not contain fillers that provide color or stabilizers. Bamak VCS rubber appears to be a base rubber from which the rest of the Bamak product line is formulated. Bamak VCS (formerly known as Bamak MR) is a reaction product of a combination of monomers having ethylene, methyl acrylate, and carboxylic acid curing sites, and once formed, is substantially free of release agents such as octadecylamine, complex organophosphates and / or stearic acid, and antioxidants such as substituted diphenylamines.

[0044] Alternatively, the reinforcing component may be a dipolymer of ethylene and methyl acrylate. In one variation of this alternative, the dipolymer thus formed is substantially free of processing aids and antioxidants. Of course, the rubber reinforcing agent may also be a combination of the reaction product from the previous paragraph and the dipolymer from this paragraph, either or both of which may be substantially free of processing aids and antioxidants.

[0045] The reinforcing ingredients should be present at a concentration of approximately 1.5% to a maximum of 8% by weight, for example, approximately 5% to a maximum of 8% by weight, with approximately 7% to a maximum of 8% by weight being particularly desirable. Amounts exceeding 8% by weight are undesirable.

[0046] As mentioned, the cyanoacrylate compositions exclude hexanediol diacrylate ("HDDA"). Although HDDA is known to improve the thermal performance of cyanoacrylates, its presence has been shown to be detrimental to the high-temperature strength of the cured products of the cyanoacrylate compositions. See the examples below. Therefore, HDDA is excluded from the cyanoacrylate compositions of the present invention.

[0047] The cyanoacrylate composition of the present invention may include any one or more accelerators selected from calixarenes and oxacalixarenes, silacron, crown ethers, cyclodextrins, poly(ethylene glycol) di(meth)acrylates, ethoxylated hydrogen compounds, and combinations thereof.

[0048] Many calixarenes and oxacalixarenes are known and reported in the patent documents. See, for example, U.S. Patents 4,556,700, 4,622,414, 4,636,539, 4,695,615, 4,718,966 and 4,855,461. The disclosures of each of these are expressly incorporated herein by reference.

[0049] For example, with respect to calixarenes, those with the following structures are useful in this specification.

[0050] [ka]

[0051] In the formula, R 1 R is an alkyl, alkoxy, substituted alkyl, or substituted alkoxy, 2 is H or alkyl, and n is 4, 6, or 8.

[0052] One particularly desirable calixarene is tetrabutyltetra[2-ethoxy-2-oxoethoxy]calix-4-arene.

[0053] Many crown ethers are known. For example, examples that may be used herein, individually or in combination, or in combination with other first accelerators, include 15-crown-5, 18-crown-6, dibenzo-18-crown-6, benzo-15-crown-5-dibenzo-24-crown-8, dibenzo-30-crown-10, tribenzo-18-crown-6, asym-dibenzo-22-crown-6, dibenzo-14-crown-4, dicyclohexyl-18-crown-6, dicyclohexyl-24-crown-8, cyclohexyl-12-crown-4, 1,2-decaryl-15-crown-5, 1,2-naphtho-15-crown-5, 3,4,5-naphthyl-16-crown-5, 1,2-methyl-benzo-18-crown-6, 1,2-methylbenzo-5, 6-methylbenzo-18-crown-6, 1,2-t-butyl-18-crown-6, 1,2-vinylbenzo-15-crown-5, 1,2-vinylbenzo-18-crown-6, 1,2-t-butyl-cyclohexyl-18-crown-6, asym-dibenzo-22-crown-6, and 1,2-benzo-1,4-benzo-5-oxygene-20-crown-7.

[0054] [Chemical formula]

[0055] See U.S. Patent No. 4,837,260 (Sato). The disclosure is hereby expressly incorporated herein by reference.

[0056] Among the sila crowns, many are also known and reported in the literature. For example, a typical sila crown may be represented within the following structure.

[0057] Wherein, R 3 and R 4 are organic groups that do not themselves cause the polymerization of the cyanoacrylate monomer, R 5 is H or CH3, and n is an integer from 1 to 4. Suitable R 3 and R 4Examples of groups include the R group, alkoxy groups such as methoxy, and aryloxy groups such as phenoxy. 3 and R 4 The group may contain a halogen or other substituent, an example being trifluoropropyl. However, R 4 Group, R 5 Unsuitable groups include basic groups such as amino groups, substituted amino groups, and alkylamino groups.

[0058] Specific examples of silacrown compounds useful in the composition of the present invention are as follows:

[0059] [ka]

[0060] [ka]

[0061] [ka]

[0062] See, for example, U.S. Patent No. 4,906,317 (Lieu). Its disclosure is expressly incorporated herein by reference.

[0063] Many cyclodextrins may be used in connection with the present invention. For example, those described and claimed in U.S. Patent No. 5,312,864 (Wentz) (the disclosure of which is expressly incorporated herein by reference) as hydroxyl group derivatives of α, β, or γ-cyclodextrins that are at least partially soluble in cyanoacrylates would be a suitable choice.

[0064] For example, poly(ethylene glycol) di(meth)acrylates suitable for use in this specification include those with the following structures:

[0065] [ka]

[0066] In the formula, n is greater than 3, for example, in the range of 3 to 12, with a particularly desirable n being 9. More specific examples include PEG200DMA (n approximately 4), PEG400DMA (n approximately 9), PEG600DMA (n approximately 14), and PEG800DMA (n approximately 19), where the number (e.g., 400) represents the average molecular weight in grams / moles of the glycol portion of the molecule excluding the two methacrylate groups (i.e., 400 g / mol). A particularly desirable PEG DMA is PEG400DMA.

[0067] And, among the ethoxylated hydrogen compounds (or ethoxylated fatty alcohols may be used), a suitable one may be selected from those with the following structures:

[0068] [ka]

[0069] In the formula, C m m can be a linear or branched alkyl or alkenyl chain, m is an integer between 1 and 30, for example, 5 to 20, n is an integer between 2 and 30, for example, 5 to 15, and R may be an alkyl such as H or C1-6 alkyl.

[0070] Commercially available examples of the materials in the above structure include those offered under the trade name Dehydrol by BASF SE in Ludwigshafen, Germany.

[0071] When used, the accelerator contained in the above structure should be included in the composition in an amount ranging from about 0.01% to about 10% by weight of the total composition, in the range of about 0.1% to about 0.5% by weight, with about 0.4% by weight being particularly desirable.

[0072] Stabilizer packages are also typically included in cyanoacrylate compositions. The cyanoacrylate composition of the present invention is no exception. The stabilizer package may contain one or more free radical stabilizers and anionic stabilizers, the nature and amount of each of which are well known to those skilled in the art. See, for example, U.S. Patents 3,742,018, 5,530,037, and 6,607,632. The disclosures of each of these are incorporated herein by reference.

[0073] Commonly used free radical stabilizers include phenolic stabilizers such as hydroquinone and its derivatives (see, for example, Patent '018), and commonly used anion stabilizers include boron trifluoride, boron trifluoride etherate, sulfur trioxide (and its hydrolysis products), sulfur dioxide, and methanesulfonic acid.

[0074] Other additives may be included to impart additional physical properties such as impact resistance (e.g., citric acid), thickness (e.g., polymethyl methacrylate), thixotropy (e.g., fumed silica), and color (e.g., dyes).

[0075] These other additives may, of course, be used individually in the composition of the present invention in amounts of about 0.05% to about 20% by weight, for example, about 1% to 15% by weight, preferably 5% to 10% by weight, depending on the identity of the additive. More specifically, for example, citric acid may be used in the composition of the present invention in amounts of 5 to 500 ppm, preferably 10 to 100 ppm.

[0076] In another embodiment, a method is provided for joining two substrate surfaces, comprising applying the above composition to at least one of the substrate surfaces, and then bringing the substrates together for a sufficient time to allow the adhesive to set. The substrate surfaces should be fixed in less than about 150 seconds depending on the composition, and in about 30 seconds depending on the substrate. Furthermore, the composition should exhibit tensile strength on the substrate surface to which they are applied, and as described herein, the cured product exhibits improved high-temperature strength performance without impairing thermal durability.

[0077] In yet another embodiment, a cured product of the composition of the present invention is provided.

[0078] In yet another embodiment, a method for preparing such a composition is provided. This method includes providing the enumerated components of a cyanoacrylate composition and mixing them to form a cyanoacrylate composition.

[0079] In yet another embodiment, a method for joining two substrate surfaces is provided. This method involves applying a cyanoacrylate composition to at least one of the substrate surfaces and joining the substrate surfaces for a sufficient time to allow the cyanoacrylate composition to form its cured product between the joined substrate surfaces.

[0080] In a further embodiment, a method for preparing a cyanoacrylate-containing composition is provided. This method comprises the steps of (a) providing (i) allyl cyanoacrylate, (ii) another cyanoacrylate selected from methyl cyanoacrylate, ethyl-2-cyanoacrylate, propyl cyanoacrylate, butyl cyanoacrylate, octyl cyanoacrylate and β-methoxyethyl cyanoacrylate, (b) fluorobenzonitrile, (c) hydrogenated aromatic anhydride, and (d) a reinforcing component, and mixing the components together for a time sufficient to form the cyanoacrylate composition.

[0081] In yet another embodiment, a method is provided for imparting improved high-temperature strength to a cured product of a cyanoacrylate composition while maintaining its heat resistance. The method comprises the steps of: providing a cyanoacrylate component comprising (a) a combination of (i) allyl cyanoacrylate and (ii) another cyanoacrylate selected from the group consisting of methyl cyanoacrylate, ethyl-2-cyanoacrylate, propyl cyanoacrylate, butyl cyanoacrylate, octyl cyanoacrylate and β-methoxyethyl cyanoacrylate; (b) fluorobenzonitrile; (c) a hydrogenated aromatic anhydride; and (d) an ethylene vinyl acetate copolymer, or a monomer having polymers of ethylene, methyl acrylate and carboxylic acid curing sites; applying the cyanoacrylate composition to at least one substrate surface, joining the substrate surfaces to which the cyanoacrylate composition has been applied, and maintaining the substrate surfaces in a joined relationship for a sufficient time to form a cured product of the cyanoacrylate composition between them to form a joined assembly; and exposing the joined assembly to high temperature conditions of about 120°C or higher, for example, about 135°C or about 150°C.

[0082] In one embodiment, the cyanoacrylate composition of the present invention comprises a cyanoacrylate component present in an amount of about 90% by weight of the total composition, wherein allyl cyanoacrylate and ethyl-2-cyanoacrylate are present in a weight ratio of preferably about 1.5:1 to about 1:1.5, preferably in approximately equal amounts; the hydrogenated aromatic anhydride is tetrahydrophthalic anhydride, present in an amount of less than about 0.1% by weight of the total composition, preferably about 0.05% to about 0.1% by weight; the fluorobenzonitrile is pentafluorobenzonitrile, present in an amount of less than about 1% by weight of the total composition, preferably about 0.5% to about 1% by weight; and the reinforcing component is present in an amount of about 5% to a maximum of 8% by weight of the total composition.

[0083] In another embodiment, the cyanoacrylate composition of the present invention comprises (a) (i) a cyanoacrylate component comprising a combination of allyl cyanoacrylate and (ii) another cyanoacrylate selected from methyl cyanoacrylate, ethyl-2-cyanoacrylate, propyl cyanoacrylate, butyl cyanoacrylate, octyl cyanoacrylate and β-methoxyethyl cyanoacrylate; (b) fluorobenzonitrile; (c) a hydrogenated aromatic anhydride; (d) an ethylene vinyl acetate copolymer having a vinyl acetate content of about 90%; (e) optionally a stable amount of acid stabilizers and free radical inhibitors; (f) optionally an accelerator component; (g) optionally an impact-resistant additive; (h) optionally a thixotropy imparter; (i) optionally a thickener; and (j) optionally a dye.

[0084] The cyanoacrylate composition of the present invention exhibits improved high-temperature strength performance without compromising heat resistance. Advantageously, when the cyanoacrylate composition of the present invention is cured at room temperature between two substrates, each composed of steel, it exhibits (a) approximately 18 N / mm². 2 (b) The initial adhesive strength is as described above, and the adhesive strength after approximately 1000 hours at a temperature of approximately 135°C is approximately 7 N / mm². 2 The above, and (c) high-temperature strength at approximately 135°C is approximately 3 N / mm 2 The above physical properties are observed.

[0085] These aspects of the present invention are further illustrated by the following examples. [Examples]

[0086] In the examples, various compositions were formulated and evaluated to highlight the benefits and advantages of the compositions of the present invention. Numerous components were used in the compositions shown in Table 1 below, varying both in specificity and quantity. Sample No. 3 contained HDDA. Sample No. 2 contained calixarene and crown ether, while the remaining samples contained only crown ether. Sample No. 1 also contained PMMA. Sample No. 2 also contained silica and bismaleimide. Furthermore, samples No. 5 and 6 contained citric acid. All samples contained stabilizer packages.

[0087] [Table 1]

[0088] The evaluation results recorded in Tables 2 to 4 and Figures 1 to 3 demonstrate the surprisingly unexpected performance of the compositions of the present invention (sample numbers 5 and 6) compared to compositions selected for comparison (sample numbers 1 to 4).

[0089] [Table 2]

[0090] The initial lap shear strengths of the grit-blasted mild steel (GBMS) samples 1-6 after 24 hours of room-temperature curing were 18.4-23.7 N / mm². 2 It has been shown to be within the range (Table 2; Figure 1).

[0091] [Table 3]

[0092] The heat resistance of these samples was investigated by aging the cured adhesive on GBMS at progressively increasing temperatures of 120°C, 135°C, and 150°C for 1000 hours (Table 3; Figure 2). Here, sample numbers 1-2 achieved a resistance of 5 N / mm² after 1000 hours at 120°C. 2It was observed that these samples maintained a lap shear strength exceeding [a certain value]. However, these samples did not show strength after 1000 hours at 135°C and 150°C. In contrast, samples 3-6 showed improved heat resistance (durability) after 1000 hours, particularly at high temperatures of 135°C and 150°C.

[0093] [Table 4]

[0094] However, when evaluating overall high-temperature performance, the high-temperature strength performance of a cyanoacrylate composition is a useful measure. At a specific temperature, it is 3 N / mm². 2 The above high-temperature strength is 7 N / mm 2 When combined with the heat resistance (durability) described above, it is considered sufficient to demonstrate the thermal performance at that temperature.

[0095] Therefore, the high-temperature strengths observed for samples 1-6 were determined by measuring the wrap shear strength of the GBMS of the cured compositions at 120°C, 135°C, and 150°C (Table 4; Figure 3).

[0096] Samples 1-2 exhibit sufficient high-temperature strength at both 120°C and 135°C. However, these samples demonstrate poor heat resistance (durability) at 135°C, meaning these cyanoacrylate compositions are considered to have high-temperature performance only up to a maximum of 120°C. Sample 3, containing HDDA, maintained a strength of 3 N / mm² at all the high temperatures evaluated, namely 120°C, 135°C, and 150°C. 2 The above threshold requirements are not met. Therefore, although sample number 3 has heat resistance (durability) at these temperatures, it does not meet the overall high-temperature performance requirements.

[0097] Samples 4-6 demonstrate improved high-temperature strength performance achievable by excluding HDDA. However, quite unexpectedly, samples 5 and 6 maintain a strength of 3 N / mm at both 120°C and 135°C without compromising heat resistance. 2 It exhibits the above high-temperature strength.

Claims

1. (a) (i) Allyl cyanoacrylate and (ii) Another cyanoacrylate selected from the group consisting of methyl cyanoacrylate, ethyl-2-cyanoacrylate, propyl cyanoacrylate, butyl cyanoacrylate, octyl cyanoacrylate and β-methoxyethyl cyanoacrylate, Cyanoacrylate components including combinations of (b) Fluorobenzonitrile, (c) Hydrogenated aromatic anhydrides, and (d) Strengthening ingredient A cyanoacrylate composition containing the above.

2. A cyanoacrylate composition according to claim 1, which does not contain hexanediol diacrylate.

3. The hardened product has the following physical properties: (a) Approximately 18 N / mm ２ The above initial adhesive strength; (b) Adhesion strength of approximately 7 N / mm after approximately 1000 hours at a temperature of approximately 135°C. ２ The above; and (c) High-temperature strength at approximately 135°C is approximately 3 N / mm ２ That's all. A cyanoacrylate composition according to claim 1 or 2, which exhibits the characteristics of the cyanoacrylate composition described in claim 1 or 2.

4. The cyanoacrylate composition according to claim 3, wherein the aforementioned physical properties were measured on a steel substrate.

5. A cyanoacrylate composition according to any one of claims 1 to 4, wherein allyl cyanoacrylate and another cyanoacrylate are present in a weight percentage ratio of about 1:

1.

6. The cyanoacrylate composition according to any one of claims 1 to 5, wherein the fluorobenzonitrile is selected from pentafluoronitrobenzene, pentafluorobenzonitrile, α,α,α-2-tetrafluoro-p-tolunitrile, and tetrafluoroisophthalonitrile.

7. A cyanoacrylate composition according to any one of claims 1 to 6, wherein fluorobenzonitrile is present in an amount of about 0.01% to about 3% by weight.

8. The cyanoacrylate composition according to any one of claims 1 to 7, wherein the hydrogenated aromatic anhydride is selected from tetrahydrophthalic anhydrides such as 3,4,5,6-tetrahydrophthalic anhydride.

9. A cyanoacrylate composition according to any one of claims 1 to 8, wherein a hydrogenated aromatic anhydride is present in an amount of up to about 0.5% by weight.

10. The cyanoacrylate composition according to any one of claims 1 to 9, wherein fluorobenzonitrile is present in an amount about an order of magnitude greater than that of the hydrogenated aromatic anhydride.

11. The cyanoacrylate composition according to any one of claims 1 to 10, wherein the reinforcing component is present in an amount of about 5% to a maximum of 8% by weight.

12. The composition according to any one of claims 1 to 11, further comprising a filler.

13. The composition according to claim 12, wherein the filler is selected from the group consisting of carbon black, silica, and combinations thereof.

14. The composition according to any one of claims 1 to 13, further comprising a stable amount of an acid stabilizer and a free radical inhibitor.

15. The composition according to any one of claims 1 to 14, wherein the reinforcing component is selected from the group consisting of ethylene vinyl acetate copolymer, ethylene polymer, methyl acrylate, monomers having carboxylic acid curing sites, and combinations thereof.

16. The composition according to any one of claims 1 to 15, further comprising an accelerator component selected from the group consisting of calixarene, oxacalixarene, silacrone, cyclodextrin, crown ether, poly(ethylene glycol) di(meth)acrylate, ethoxylylated hydrogen compounds, and combinations thereof.

17. The composition according to claim 16, wherein the calixarene is tetrabutyltetra[2-ethoxy-2-oxoethoxy]calix-4-arene.

18. Crown ethers include 15-crown-5,18-crown-6, dibenzo-18-crown-6, benzo-15-crown-5-dibenzo-24-crown-8, dibenzo-30-crown-10, tribenzo-18-crown-6, asym-dibenzo-22-crown-6, dibenzo-14-crown-4, dicyclohexyl-18-crown-6, dicyclohexyl-24-crown-8, cyclohexyl-12-crown-4, 1,2-decalyl-15-crown-5, 1,2-naphtho-15-crown-5, and 3,4,5-naphthyl The composition according to claim 16, selected from the group consisting of -16-crown-5, 1,2-methyl-benzo-18-crown-6, 1,2-methylbenzo-5,6-methylbenzo-18-crown-6, 1,2-t-butyl-18-crown-6, 1,2-vinylbenzo-15-crown-5, 1,2-vinylbenzo-18-crown-6, 1,2-t-butyl-cyclohexyl-18-crown-6, asym-dibenzo-22-crown-6, 1,2-benzo-1,4-benzo-5-oxygen-20-crown-7 and combinations thereof.

19. Poly(ethylene glycol) di(meth)acrylate has the following structure: 【Chemistry 1】 (In the formula, n is greater than 3) The composition according to claim 16.

20. The composition according to any one of claims 1 to 19, further comprising an additive selected from the group consisting of impact-resistant additives, thixotropy-imparting agents, thickeners, dyes, heat-degradation-resistant enhancers, and combinations thereof.

21. (a) (i) Allyl cyanoacrylate and (ii) Another cyanoacrylate selected from the group consisting of methyl cyanoacrylate, ethyl-2-cyanoacrylate, propyl cyanoacrylate, butyl cyanoacrylate, octyl cyanoacrylate and β-methoxyethyl cyanoacrylate, The cyanoacrylate components, (i) and (ii), including the combination of (i) and (ii), are present in a weight percentage ratio of approximately 1.5:1 to approximately 1:1.

5. (b) an amount of less than approximately 1.0% by weight of fluorobenzonitrile (c) A hydrogenated aromatic anhydride in an amount of less than approximately 0.1% by weight, and (d) Ethylene vinyl acetate copolymer having a vinyl acetate content of approximately 90% in an amount of less than approximately 8% by weight, A cyanoacrylate composition containing the above.

22. (a) (i) Allyl cyanoacrylate and (ii) Another cyanoacrylate selected from the group consisting of methyl cyanoacrylate, ethyl-2-cyanoacrylate, propyl cyanoacrylate, butyl cyanoacrylate, octyl cyanoacrylate and β-methoxyethyl cyanoacrylate, Cyanoacrylate components including combinations of (b) Fluorobenzonitrile, (c) Hydrogenated aromatic anhydride, (d) Ethylene vinyl acetate copolymer having a vinyl acetate content of approximately 90%, (e) Optionally, a stable amount of an acid stabilizer and a free radical inhibitor, (f) Optionally, accelerator components, (g) Optionally, impact-resistant additives, (h) Optionally, a thixotropic agent, (i) Optionally, a thickener, and (j) Optionally, dyes, A cyanoacrylate composition comprising the following.

23. A cured product of the composition according to any one of claims 1 to 22.

24. A step of applying the cyanoacrylate composition according to any one of claims 1 to 22 to at least one surface of a substrate, and A step of joining the substrate surfaces for a sufficient time to allow the cyanoacrylate composition to form its cured product between the joined substrate surfaces, A method for joining two substrate surfaces, including [a specific component].

25. (a) (i) Allyl cyanoacrylate and (ii) Another cyanoacrylate selected from the group consisting of methyl cyanoacrylate, ethyl-2-cyanoacrylate, propyl cyanoacrylate, butyl cyanoacrylate, octyl cyanoacrylate and β-methoxyethyl cyanoacrylate, (b) Fluorobenzonitrile, (c) Hydrogenated aromatic anhydrides, and (d) a reinforcing component; A process of providing components selected from, A step of mixing the components together for a sufficient amount of time to form the cyanoacrylate composition, A method for preparing a cyanoacrylate-containing composition according to any one of claims 1 to 22, comprising the above.

26. A method for imparting improved high-temperature strength to a cured product of a cyanoacrylate composition while maintaining its heat resistance, (a) (i) Allyl cyanoacrylate and (ii) Another cyanoacrylate selected from the group consisting of methyl cyanoacrylate, ethyl-2-cyanoacrylate, propyl cyanoacrylate, butyl cyanoacrylate, octyl cyanoacrylate and β-methoxyethyl cyanoacrylate, Cyanoacrylate components including combinations of (b) Fluorobenzonitrile, (c) Hydrogenated aromatic anhydrides, and (d) Ethylene vinyl acetate copolymer, or an ethylene polymer, methyl acrylate and monomer having a carboxylic acid curing site, A step of providing a cyanoacrylate composition containing, The steps include: applying the cyanoacrylate composition to at least one substrate surface, joining the substrate surfaces to which the cyanoacrylate composition has been applied, and maintaining the substrate surfaces in a joined position for a sufficient time to form a cured product of the cyanoacrylate composition between them and to form a bonded assembly; A step of exposing the joined assembly to high-temperature conditions of approximately 120°C or higher, Methods that include...

27. The method according to claim 26, wherein the high temperature condition is approximately 135°C.

28. The method according to claim 26, wherein the high temperature condition is approximately 150°C.

29. The method according to any one of claims 26 to 28, wherein the base material is made of steel.

30. The thermal durability is substantially maintained, with a load of approximately 7 N / mm² after approximately 1000 hours at a temperature of approximately 135°C. ２ The adhesive strength is as described above, and the high-temperature strength under the aforementioned high-temperature conditions is 3 N / mm when the cyanoacrylate composition is placed between steel substrates and cured. ２ The method according to any one of claims 26 to 29.

Images