JPH0142982B2 - - Google Patents

Description

[Detailed description of the invention]

(a) Industrial application field The present invention relates to α-cyanoacrylate adhesives, and its purpose is to improve initial adhesive strength, especially adhesion, which has been difficult to adhere to with conventional α-cyanoacrylate adhesives. The goal lies in improving the initial adhesive strength of materials. (b) Conventional technology α-cyanoacrylate is extremely susceptible to anionic polymerization, and can be polymerized and cured in a short time without adding a catalyst or heating due to anionic active species such as solid surfaces, moisture in the air, and alkali substances. Because of its properties, it is widely used as an instant adhesive for bonding rubber, plastic, metal, glass, etc. However, instant adhesives and adhesives have traditionally been difficult to bond to α-cyanoacrylate adhesives, such as wood, chrome plating, nickel plating, polyester (FRP), Bakelite, etc. Bonding has a rather low strength and requires short time work, and there are restrictions on its use, and there is a strong desire to improve the initial bonding strength. (c) Problems to be Solved by the Invention The present inventors have previously investigated the improvement of the initial adhesive strength of α-cyanoacrylate adhesives, and have developed α-cyanoacrylate using the following formula [] [In the formula, X ₃ is a hydrogen atom or a methyl group, X ₄ is a hydrogen atom, a methyl group or a cyano group, and X ₅ is a hydrogen atom,
R ₂ or R ₂ CO (R ₂ represents a hydrocarbon residue containing no anionically polymerizable group). However, when X ₄ is a cyano group, it is excluded that X ₅ is a hydrogen atom. l, m, n are integers (l+m)≧1, n≧1
It is. By blending the polyether compound shown in ] with pyrogallol, the objective was achieved and a patent application was filed. (Patent Application No. 56-54631) The previous invention is characterized in that α-cyanoacrylate is combined with pyrogallol and a specific polyalkyl ether compound having a functional group that can be copolymerized with α-cyanoacrylate. However, as the present inventors proceeded with their studies, they discovered that if the specified polyphenols were used, one of the polyalkyl ethers did not need to be copolymerized with α-cyanoacrylate, and that specific alcohols and We have completed the present invention by discovering that even with this ester, it is possible to improve the initial adhesive strength without losing the stability and strength of conventional α-cyanoacrylates, which was the objective of the prior invention. (d) Means for solving the problems That is, the present invention uses α-cyanoacrylate (1)
Polyhydric alcohol or its derivative, or formula [] (In the formula, X ₁ and X ₂ are hydrogen atoms, halogen atoms,
Indicates a hydroxyl group, a substituted or unsubstituted alkyl group, an alkenyl group, an aryl group, an aralkyl group, and X ₁
and X ₂ may be the same or different. p represents an integer of 1 or more, q represents an integer of 2 or more, and the terminal may be formed into a ring. ) Compounds 0.1-2 selected from the group of compounds having a repeating unit
Weight% and formula (2) [] (In the formula, r is 2 to 3, and at least two hydroxyl groups are adjacent to each other.) 0.01-0.1% by weight of an α-cyanoacrylate adhesive composition. It is a thing. However, the formula for α-cyanoacrylate [] [In the formula, X ₃ is a hydrogen atom or a methyl group, X ₄ is a hydrogen atom, a methyl group or a cyano group, and X ₅ is a hydrogen atom,
R ₂ or R ₂ CO (R ₂ represents a hydrocarbon residue containing no anionically polymerizable group). However, when X ₄ is a cyano group, except that X ₅ is a hydrogen atom.
l, m, and n are integers, and (l+m)≧1 and n≧1. The case where the polyether compound shown in ] and pyrogallol are combined is excluded from the present invention. The α-cyanoacrylate used in the present invention is represented by the general formula [], In the formula, R ₄ includes substituted or unsubstituted alkyl, alkenyl, aryl, cyclohexyl, etc., and specifically, for example, methyl, ethyl, n-,
i-propyl, n-, i-, sec-butyl, pentyl, hexyl, octyl, ethylhexyl, dodecyl, allyl, propargyl, methoxyethyl,
These α-cyanoacrylates include not only one type but also two types.
It is also possible to use a mixture of more than one species. Examples of polyhydric alcohols to be blended with α-cyanoacrylate in the present invention include ethylene glycol, propylene glycol, tetramethylene glycol, hexamethylene glycol, octamethylene glycol, polybutadiene diol, chloropropylene glycol, 3-methylpentanediol, , 2-diethylpropanediol, 2-ethyl-1,4-butanediol, glycerin, trimethylolmethane, trimethylolethane, trimethylolpropane, 1,2,6
-Hexanetriol, 2,5-hexanediol, etc., and derivatives thereof include alkyl, alkenyl, aryl, and aralkyl ethers or esters thereof, specifically, for example, methyl cellosolve, ethyl cellosolve, ethylene glycol- n-butyl ether, ethylene glycol phenyl ether, ethylene glycol benzyl ether, propylene glycol methyl ether, tetramethylene glycol propyl ether, ethylene glycol diethyl ether, ethylene glycol acetate, ethylene glycol monolaurate, ethylene glycol monostearate, ethylene glycol Examples include, but are not limited to, distearate, ethyl cellosolve stearate, glycerin monolaurate, glycerin monostearate, sorbitan monolaurate, cellosolve acrylate, cellosolve methacrylate, and cellosolve crotonate. In the compound having a repeating unit of the formula [] to be blended into α-cyanoacrylate in the present invention, X ₁ and X ₂ are as described above, but they may be the same or different, and X ₁ and/or X ₂ in the repeat unit and also X ₁ and/or X ₂ in the repeat unit of q
You can use the same or different ones. In the formula, p means a repeating carbon main chain in the main chain skeleton, and q shows a repeating unit of polyether. When p=1, the skeleton is a methylene group or a substituted methylene group, and when p≧2, the skeleton is an ethylene group, a trimethylene group, a polymethylene group, or a substituted polyethylene group thereof, but in the present invention, preferably p is 2 to 6. Further, the preferable range of q is about 2 to 3,000, and if it exceeds this value, especially 10,000 or more, the compatibility with α-cyanoacrylate becomes poor and a uniform composition cannot be obtained. In addition, the polyether compound having a repeating unit of formula [] may form a ring structure,
Examples include crown ethers. In the present invention, specific examples of compounds having a repeating unit of formula [] to be blended into α-cyanoacrylate include the following compounds,
It is not limited to these. Formaldehyde condensates, acetaldehyde condensates, trioxane polymers, polyalkylene glycols (e.g. diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol (400, 1000, etc.), dipropylene glycol, polypropylene glycol, polytetramethylene oxide, poly 3,3-
Bis(chloromethyl)butylene oxide, poly 1,3-dioxolane, ethylene oxide propylene oxide block polymer, etc. ), polyalkylene glycol monoethers (e.g., motyl carbitol, carbitol, diethylene glycol-n-butyl ether, diethylene glycol phenyl ether, diethylene glycol benzyl ether, dipropylene glycol ethyl ether, tripropylene glycol methyl ether, polyethylene glycol methyl ether,
Polyethylene glycol propyl ether, polyethylene glycol lauryl ether, polyethylene glycol stearyl ether, polyoxyethylene nonyl phenyl ether, polyethylene glycol allyl ether, etc. ), polyalkylene glycol diethers (e.g., diethylene glycol diethyl ether, diethylene glycol di-n-butyl ether, triethylene glycol dimethyl ether, tetraethylene glycol distearyl ether, polyethylene glycol dimethyl ether, etc.), polyalkylene glycol monoesters (e.g., diethylene glycol monoester), Propionate, tetraethylene glycol monoacetate, tripropylene glycol mono-n-butyrate, polyethylene glycol monoacetate, polyethylene glycol monopropionate, polyethylene glycol laurate, polyethylene glycol cesylate, polyethylene glycol stearate, polyethylene glycol oleate ate, polyoxyethylene sorbitan monolaurate, diethylene glycol acrylate, diethylene glycol methacrylate, diethylene glycol crotonate, etc.),
Polyalkylene glycol diesters (e.g.
Diethylene glycol diacetate, diethylene glycol dipropionate, diethylene glycol diacrylate, diethylene glycol distearate, diethylene glycol dimethacrylate, tetraethylene glycol dicrotonate, polyethylene glycol diacetate, polyethylene glycol di-n-butyrate, polyethylene glycol diurarate, polyethylene glycol Diacrylate, polyethylene glycol dimethacrylate, polyethylene glycol dicrotonate, polyethylene glycol di-α-
Cyanoacrylate, polyethylene glycol stearyl methacrylate, polyethylene glycol lauryl acrylate, etc. ), polyalkylene glycol monoether monoesters (e.g. acrylates, methacrylates, crotonates of glycol monoether compounds such as methyl carbitol, carbitol, tetraoxyethylene methyl ether, polyoxyethylene lauryl ether, polyoxyethylene nonyl phenyl ether) , or α-cyanoacrylate, etc.), other bisphenol A-polyalkylene oxide adducts, trimethylolpropane-polyalkylene oxide adducts, chrycerin-polyalkylene oxide adducts, adipic acid-polyalkylene oxide adducts, trimethic acid -Polyalkylene oxide adducts, etc. Examples of other cyclic compounds include 18-crown-6, 15-crown-5, 18-crown-5, dithia-15-crown, dibenzo-18-crown-6, dicyclohexyl-18-crown-6, 1,2 -Naft-15
-Crown-5, 1,2-methylbenzo-18-crown-6, etc. can also be used. In the present invention, the polyhydroxy compound of formula [] to be blended with α-cyanoacrylate is as follows:
Mention may be made of caterol, pyrogallol and 1,2,4-benzenetriol. The polyhydric alcohols or ether compounds having a repeating unit represented by the formula [] used in the present invention may be used in combination of two or more selected from these groups, and the amount of these compounds used may be is preferably determined comprehensively by the amount of polyhydroxybenzene represented by the formula []. However, the amount of polyhydric alcohol or/and ether compound added is preferably 0.05-20% by weight, preferably 0.1-2% by weight based on α-cyanoacrylate, and the amount of polyhydroxybenzene added is particularly good for α-cyanoacrylate. 0.0001-0.5% by weight, preferably 0.01-0.1
The range of weight % is particularly good; if both are too small, there will be no change in the effect, but if either is added too much, it is not preferable because it will reduce both the curing speed and adhesive strength of the α-cyanoacrylate monomer. The adhesive composition of the present invention has been found to have superior initial adhesive strength when adhering to adherends that are slightly acidic compared to other materials such as wood, chrome plating, nickel plating, polyester (FRP), Bakelite, etc. It will be done. The above (1) polyhydric alcohols, specific ether compounds, and (2) specific polyhydroxybenzene are α
-The reason why cyanoacrylate has this effect is not clear, but it is thought that some kind of interaction between the compound groups (1) and (2) accelerates the curing speed of α-cyanoacrylate. . In addition, the adhesive obtained by the present invention has a conventional α
- Stabilizers used in cyanoacrylate adhesives (e.g. anionic polymerization inhibitors such as sulfur dioxide, sulfonic acid, sultone, radical polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, etc.), thickeners (for example, polymethyl methacrylate), plasticizers, colorants, fragrances, containers, etc. may also be added and blended as appropriate depending on the purpose within a range that does not impede the stability of the monomer. (E) Examples Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples. All percentages in the examples indicate weight percentages, and the adhesive strength was measured by the following method. Two steel plates (100 x 25 x 1.6 mm) bonded area 25 x
They were bonded together with 12.5 mm layers and cured under the environmental conditions of 20℃ and 60% RH. After 5 minutes and 24 hours, the tensile shear strength was measured at a tensile speed of 50 mm/min, and the results were as follows: Kg・f/
Expressed in ^cm2 . Examples 1 to 5, Comparative Examples 1 to 3 Sulfur dioxide 0.002 as an anionic polymerization inhibitor for ethyl α-cyanoacrylate monomer
% and hydroquinone as a radical polymerization inhibitor
Ethyl α-cyanoacrylate adhesive containing 0.1%, 2% of various polyhydric alcohols or polyhydric alcohol derivatives shown in Table 1 based on α-cyanoacrylate, and 0.05% of polyhydroxybenzene shown in formula [] A steel-to-steel adhesion test was conducted on each of the two, and the results are shown in Table 1. Regarding the ethyl α-cyanoacrylate adhesive used in this example (no polyhydric alcohol or polyhydroxybenzene added), and the adhesive agent containing only either polyhydric alcohol or polyhydroxybenzene, An adhesion test was also conducted, and the results are shown in Table 1 as a comparative example. As shown in Table 1, α-
Cyanoacrylate adhesives have significantly improved initial bond strength.

[Table] Examples 6 to 11, Comparative Examples 4 to 7 Polyethylene glycol distearate and polyethylene glycol monomethyl monomer were added to ethyl α-cyanoacrylate adhesive containing 0.0015% sulfur dioxide and 0.1% hydroquinone based on ethyl α-cyanoacrylate monomer. Methacrylate, pyrogallol, and catechol were added and blended in various amounts shown in Table 2, and the adhesive strength of each was measured. Table 2 shows the results. However, polyethylene glycol distearate was used after being dissolved in the same amount of dioxane as shown in the table. There was no effect on storage stability. From Table 2, ether compounds of formula [] and formula []
A wide range of mixing ratios with compounds is recognized;
The improvement in initial bond strength is obvious.

[Table] Examples 12 to 18 Repeating units of the formula [] shown in Table 4 were added to an ethyl α-cyanoacrylate adhesive containing 0.002% sulfur dioxide and 0.1% hydroquinone based on the ethyl α-cyanoacrylate monomer. Table 3 shows the results of a steel-to-steel adhesion test of various ether compounds containing the following formulas and various compounds of the formula []. In each example, initial adhesion strength and 24
The strength after hours has been improved.

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Claims (1)

[Claims] 1 α-cyanoacrylate (1) polyhydric alcohol or its derivative, or formula [] (In the formula, X ₁ and X ₂ are hydrogen atoms, halogen atoms,
Indicates a hydroxyl group, a substituted or unsubstituted alkyl group, an alkenyl group, an aryl group, an aralkyl group, and X ₁
and X ₂ may be the same or different. p represents an integer of 1 or more, q represents an integer of 2 or more, and the terminal may be formed into a ring. ) Compounds 0.1 to 2 selected from the group of compounds having a repeating unit
Weight% and formula (2) [] (In the formula, r is 2 to 3, and at least two hydroxyl groups are adjacent to each other.) 0.01 to 0.1% by weight of an α-cyanoacrylate adhesive composition. thing. However, α-cyanoacrylate has the formula [ ] [In the formula, X ₃ is a hydrogen atom or a methyl group, X ₄ is a hydrogen atom, a methyl group or a cyano group, X ₅ is a hydrogen atom,
R ₂ or R ₂ CO (R ₂ represents a hydrocarbon residue containing no anionically polymerizable group). However, when X ₄ is a cyano group, it is excluded that X ₅ is a hydrogen atom. l, m, n are integers (l+m)≧1, n≧1
It is. ] Excludes the case where the polyether compound shown by and pyrogallol are blended.