JPH0143790B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an α-cyanoacrylate adhesive, and its purpose is to improve the initial adhesive strength, particularly for adherend materials that are difficult to adhere to with conventional α-cyanoacrylate adhesives. be. α-Cyanoacrylate is extremely susceptible to anionic polymerization, and has the property of polymerizing and curing in a short time without adding a catalyst or heating due to anionic active species such as solid surfaces, moisture in the air, and alkaline substances. It is widely used as an instant adhesive to bond plastics, metals, 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, and other adherends. Adhesive strength is rather low, and there are restrictions on the use of adhesives that require short-time work, and there is a strong desire to improve the initial adhesive strength. The present inventors have previously investigated the improvement of the initial adhesive strength of α-cyanoacrylate adhesives, and have determined that α-cyanoacrylate has 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. ] and the following formula [] (In the formula, R ₃ is a hydrogen atom or a substituted or unsubstituted hydrocarbon residue, and h is an integer of 2 or more.) By blending the product with a polyhydroxycarboxylic acid represented by the formula, the object was achieved and a patent application was filed. (Special request 1977
-173813) The previous invention is characterized in that α-cyanoacrylate is combined with a polyhydroxycarboxylic acid 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 found that if the specified polycarboxylic acid was used, one polyalkyl ether did not need to be copolymerized with α-cyanoacrylate, and that specific alcohols and their The present invention was completed based on the discovery that even with esters, the initial adhesive strength can be improved without losing the object of the prior invention, that is, the stability and strength of conventional α-cyanoacrylates. 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 form a ring. ) A compound selected from the group of compounds having a repeating unit of the formula (2) [] (HOOC-)eA-(COOR ₁ ) f [] (wherein A is a hydrogen atom or a substituted or unsubstituted Hydrocarbon residue or heterocyclic compound residue, R ₁ is a substituted or unsubstituted hydrocarbon residue, e≧1 integer, f≧
Indicates an integer of 0. However, when A has two or more phenolic hydroxyl groups, e=0 may be used only when f≧1. Further, the polyhydric carboxylic acid may be ring-closed to become an anhydride. This is an α-cyanoacrylate adhesive composition which is blended with a compound selected from the group of carboxylic acids or esters shown in (a). However, the case where the following compounds (3) and (4) are combined with α-cyanoacrylate is excluded from the present invention. (3) 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, except that X ₅ is a hydrogen atom.
l, m, and n are integers, and (l+m)≧1 and n≧1. ] and the polyether compound represented by formula (4) [] (In the formula, R ₃ is a hydrogen atom or a substituted or unsubstituted hydrocarbon residue, and h is an integer of 2 or more.) A polyhydroxycarboxylic acid represented by the formula: 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 Examples include, but are not limited to, glycol 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 the repeating unit of p may be 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 3000, and if it exceeds this value, particularly 10000 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 condensate, acetaldehyde condensate, trioxane polymer, polyalkylene glycol (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 polymers, etc. ), polyalkylene glycol monoethers (e.g. methyl 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 dimethyl 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 Monopropionate, 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, 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, glycerin-polyalkylene oxide adducts, adipic acid-polyalkylene oxide adducts, trimet Examples include acid-polyalkylene oxide adducts. 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 carboxylic acid of the formula [ ] and its anhydride and ester compounds to be blended into the α-cyanoacrylate must have one or more phenolic hydroxyl groups, unless the compound has two or more phenolic hydroxyl groups.
It must have at least one free carboxy group. Specific examples of these carboxylic acids are listed below, but the invention is not limited thereto. Examples of aliphatic carboxylic acids include formic acid, acetic acid,
Glycolic acid, β-hydroxypropionic acid, lactic acid, α-hydroxyisobutyric acid, mannonic acid, gluconic acid, talonic acid, oxalic acid, malonic acid, succinic acid,
Succinic anhydride, α-ketosuccinic acid, α-methylsuccinic acid, methylmalonic acid, glutaric acid, glutaric anhydride, maleic acid, itaconic acid, itaconic acid monoethyl ester, tartronic acid, ethyltartronic anhydride, malic acid, α -oxy-α'-methylsuccinic acid, methyltartaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, 1-methyl-butane-1,4-dicarboxylic acid, 2-methylene-5
-Methyladipic acid, muconic acid, butenylsuccinic anhydride, α-chloroadipic acid, ethylene bispropionic acid, aconitic acid, aconitic acid di-
n-butyl ester, 1-butene-2,3,4-
Tricarboxylic acid, carboxymethyloxysuccinic acid, 1-cyano-propane-1,2,3-tricarboxylic acid, ethane-1,1,2,2-tetracarboxylic acid, cyclohexanedicarboxylic acid and its anhydride, 3-methylhexene -4,5,6-tricarboxylic acid, cyclopentanetetracarboxylic acid,
1,2-dibromo-3-methylcyclohexane-
4,5,6-tricarboxylic acid, cinnamic acid, m-hydroxycinnamic acid, mandelic acid, attractic acid, 1
-phenyloxybutane-2,4-dicarboxylic acid and the like. Examples of aromatic carboxylic acids include benzoic acid,
Salicylic acid, 3-hydroxy-2-nitrobenzoic acid, vanillic acid, 5-hydroxy-3methylbenzoic acid, 5-nitrovanilic acid, resorcylic acid, protocatekyic acid, protocatekylic acid propyl ester, piperonic acid, gallic acid, dichlorogallic acid Acid, gallic acid methoxyethyl ester, 3,6-
Dichlorophthalic acid, 4,5-dioxyphthalic acid,
Examples include 3-nitrophthalic anhydride, diphenic acid, naphthalene 1,5-dicarboxylic acid, trimellitic acid, trimellitic anhydride, pyromellitic acid, and pyromellitic anhydride. Examples of the heterocyclic carboxylic acid include quinoline phosphoric acid, pyrrole-2,3-dicarboxylic acid, quinoxaline-2,3-dicarboxylic acid, 2,5-thiophenedicarboxylic acid, and tetrahydrofuran tetracarboxylic acid. The polyhydric alcohols or ether compounds having repeating units represented by the formula [] used in the present invention can be used in combination of two or more selected from the group, and the amount of these compounds to be used is determined by the formula [ ] It is preferable to comprehensively determine the amount of carboxylic acids used. However, the amount of polyhydric alcohol or/and ether compound added is usually 0.05 to 20% by weight based on α-cyanoacrylate, and the amount of carboxylic acids added is 0.0001 to 0.0001% by weight based on α-cyanoacrylate.
A range of 0.5% by weight is particularly good; if both are too small, there will be no change in the effect; however, adding too much of either one is undesirable because it reduces 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. Although it is not clear why the compound group consisting of (1) polyhydric alcohols, specific ether compounds, and (2) specific carboxylic acids has such an effect on α-cyanoacrylate, (1) and
It is thought that the curing speed of α-cyanoacrylate is accelerated by some kind of interaction between the compound group (2). 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. 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 at 12.5 mm, cured under environmental conditions of 20°C and 60% RH, and measured for tensile shear strength at a tensile rate of 50 mm/min after 5 minutes and 24 hours.
Expressed in f/ ^cm2 . Examples 1 to 7, 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
To the 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 various carboxylic acids shown in formula [] A steel-to-steel adhesion test was conducted on each of the two, and the results are shown in Table 1. The ethyl α-cyanoacrylate adhesive used in this example (no addition of polyhydric alcohol or carboxylic acid) and the adhesive agent containing only either polyhydric alcohol or carboxylic acid may also be used. The results are shown in Table 1 as a comparative example. As shown in Table 1, the initial adhesive strength of the α-cyanoacrylate adhesive prepared by mixing polyhydric alcohol or its derivatives with various carboxylic acids is significantly improved.

[Table] Examples 8 to 13, Comparative Examples 4 to 7 Ethyl α-cyanoacrylate adhesive containing 0.0015% sulfur dioxide and 0.1% hydroquinone based on ethyl α-cyanoacrylate monomer, polyethylene glycol distearate and polyethylene glycol monomethyl methacrylate and gallic acid methoxyethyl ester and itaconic acid in various amounts shown in Table 2,
The adhesive strength of each was measured and the results are shown in Table 2. 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 15 Ethyl α-cyanoacrylate adhesive containing 0.002% sulfur dioxide and 0.1% hydroquinone to ethyl α-cyanoacrylate monomer and 0.5% polyethylene glycol distearate to α-cyanoacrylate. % and further blended with 0.05% of various carboxylic acids shown in Table 3.
A steel adhesion test was conducted and the results are shown in Table 3.

【table】

[Table] In this example, in the carboxylic acid of formula [],
This paper examines the relationship between hydroxycarboxylic acids and their esters. Examples 12, 13 and 14 are examples of aromatic carboxylic acids in which A is free and B is ester. In these three examples, Examples 12 and 13 are trivalent and divalent hydroxy compounds, respectively, so there is no difference in effectiveness between the free acid and the ester, and both improve the initial adhesive strength.
The strength after a while also improved. However, example 14
For monohydric hydroxycarboxylic acids, their esters
14B has poor improvement effect. In contrast to aromatic carboxylic acids, as seen in Example 15D, with aliphatic carboxylic acids, even divalent hydroxy compounds have little effect on improving both initial adhesive strength and 24-hour strength when using esters. Examples 16-22 Ethyl α-cyanoacrylate adhesives containing 0.002% sulfur dioxide and 0.1% hydroquinone based on ethyl α-cyanoacrylate monomers were treated with various repeating units of the formula [] shown in Table 4. The ether compound and various compounds of formula [] were blended, and the results of the respective steel-to-steel adhesion tests are shown in Table 4. In each example, initial adhesion strength and 24
The strength after hours has been improved. Examples 23-43 0.0015% sulfur dioxide and 0.1% hydroquinone on ethyl alpha-cyanoacrylate monomer
Various ether compounds containing repeating units of formula [] shown in Table 5 and various compounds of formula [] were blended into the ethyl α-cyanoacrylate adhesive containing The results are shown in Table 5. In each example, the initial adhesion strength and the strength after 24 hours were improved.

【table】

【table】

[Table] Examples 44-46 Comparative Examples 8-10 Sulfur dioxide 0.0018% and hydroquinone 0.05% based on ethyl α-cyanoacrylate monomer
Polyethylene glycol distearate is added to the ethyl α-cyanoacrylate adhesive containing α
- Add 0.5% to cyanoacrylate, and further mix 0.05% of the compound of the formula [] shown in Table 6 to α-cyanoacrylate, and use the same adhesive to make steel, lauan plywood, chrome-plated steel. ,
The adherends of the same type of Bakelite were adhered to each other and an adhesion test was conducted, and the results are shown in Table 6. The air contact test method is for each adherend {100×25×1.6mm,
Chrome plated steel), 2mm (Bakelite), 3mm
(lauan plywood)} with an adhesion area of 25 x 12.5 mm and cured at 20°C and 60% RH. Bakelite was bonded after 5 minutes and 24 hours, lauan plywood and chrome-plated steel were bonded after 3 minutes and chrome-plated steel. The tensile shear strength was measured after 24 hours, and the results are shown in Table 6.
The unit is Kgf/ ^cm3 . According to the results revealed in Table 6, the conventional α
- The present invention α- It is clear that the use of cyanoacrylate adhesives serves a sufficient adhesive purpose. In Table 6, the tensile shear strength in the upper row is the measured value after 5 minutes of adhesion for steel and Bakelite, the measured value after 3 minutes for lauan plywood and chrome plated steel, and the lower row is the strength after 24 hours. *mark indicates broken wood.

【table】

Claims (1)

[Claims] 1 α-cyanoacrylate containing (1) a polyhydric alcohol or a derivative thereof, or the 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. ) 0.1 to 2% by weight of a compound selected from the group of compounds having a repeating unit of the formula (2) [] (HOOC-)eA-(COOR ₁ ) f [] (wherein A is a hydrogen atom or a substituted or An unsubstituted hydrocarbon residue or a heterocyclic compound residue, R ₁ is a substituted or unsubstituted hydrocarbon residue, an integer of e≧1, and an integer of f≧0.However, A has two or more phenolic When the carboxylic acid has a hydroxyl group, e may be 0 only when f≧1.Also, the polycarboxylic acid may be ring-closed to become an anhydride. An α-cyanoacrylate adhesive composition comprising 0.01 to 0.1% by weight of a compound selected from the following. 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, 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. ] and a polyether compound represented by the formula [] (In the formula, R ₃ is a hydrogen atom or a substituted or unsubstituted hydrocarbon residue, and h is an integer of 2 or more.)