JPS6221392B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a two-component curable composition that can be cured in a short time and has excellent adhesive properties such as impact adhesive strength, tensile shear adhesive strength, and durability. In recent years, in various industrial fields, the number of processes for assembling material parts using adhesives has increased, and curable compositions such as epoxy adhesives, acrylate adhesives, and cyanoacrylate adhesives are widely used. In the assembly process, belt conveyor systems are often used to improve productivity and save labor, and it is desirable to obtain the required initial bond strength in a short time, preferably within one minute. Depending on the purpose of use, impact resistance, heat resistance, weather resistance, and high adhesive strength, which are essential conditions for so-called structural adhesives, are required. However, if we look at the individual adhesives currently available, structural adhesives such as epoxy adhesives and acrylate adhesives have poor impact resistance,
Although it exhibits excellent weather resistance and adhesive strength, the actual setting time is still 10 to 30 minutes even when a two-component adhesive is used. On the other hand, cyanoacrylate adhesives have extremely fast set times ranging from a few seconds to several tens of seconds, and have strong adhesive strength and excellent performance, but are said to have insufficient impact resistance and heat resistance. There is. Such problems are inherent characteristics of these adhesive compositions, and their solution is desired. As a result of various studies to solve these problems, the present inventors have developed a radically polymerizable redox-type acrylate composition and a cyanoacrylate composition containing a sulfur-based compound other than sulfamides or an aldehyde-amine reaction product. By forming a two-component curable composition using the former/latter preferably in the range of 20/1 to 20/6 (weight ratio), the composition can be cured in an extremely short time, and It has been found that a composition is provided that does not lose any of the excellent adhesive properties inherent in acrylate-based compositions. The curing mechanism of cyanoacrylate compositions is based on an ionic polymerization reaction, and usually a very small amount of water adhering to the surface of the adherend acts as a polymerization initiator, causing rapid curing. Furthermore, it is known that the setting time can be further accelerated by treating the surface to be adhered with a primer containing a basic compound such as caustic soda, an organic amine, or a quaternary ammonium salt as an active ingredient. The curing mechanism of the cyanoacrylate composition in which the redox-type acrylate composition according to the present invention is involved is based on sulfur-based compounds other than sulfamides and/or aldehyde-amine reaction products and hydroplasts contained in the acrylate composition.
Due to the single action of organic peroxides such as oxides or their synergistic action, if desired, modifiers such as elastomers and silane compounds, and furthermore, when coloring agents and others are blended, each product including them It is presumed that the components act alone or in synergy to initiate and further accelerate the ionic polymerization reaction of the cyanoacrylate composition. The composition of the present invention can be applied to all fields in which acrylate compositions or cyanoacrylate compositions have been used, but its most distinctive feature is the ability to combine instant adhesiveness and structural adhesiveness. Therefore, it is extremely useful for bonding, in a line process, parts that have joints or fitting parts between two planes that are subject to impact force or vibration. Typical examples of suitable applications for the two-component curable composition of the present invention include adhesion of various parts in aircraft, ships, and vehicles, adhesion of window frame sashes in construction, and bonding of speaker magnets and plates in electrical equipment. Adhesion, adhesion of the rotor and shaft of small motors, assembly and adhesion of mechanical parts such as gears, pulleys, bearings, etc. and shafts, other musical instruments, sports equipment, such as skis, etc.
Examples include adhesion of golf parts. There are various adhesion methods using the composition of the present invention, and representative examples include the following. For example, in flat adhesion, (1) an acrylate composition is applied to the outer periphery of one surface of the adherend, and a cyanoacrylate composition is applied to the center of that surface, and both surfaces are bonded together. (2) Apply an acrylate composition to the outer periphery of one surface of the adherend, and apply a cyanoacrylate composition to the center of the other surface, and bring both surfaces together. (3) A method in which an acrylate composition is applied to the entire surface of one surface of the adherend, and a cyanoacrylate composition is applied to a portion or the entire surface of the other surface to bring both sides together. There is also a method for fitting adhesion: (1) A method in which an acrylate composition is applied to the male side, and after insertion into the female side, a cyanoacrylate composition is applied to the surface of the mating part. (2) A method in which an acrylate composition is applied to the entire surface of the male side, and a cyanoacrylate composition is applied to a part or the entire inner surface of the female side, and then inserted. (3) When fitting with a large clearance, there is a method in which the male is inserted into the female side in advance, the acrylate composition is injected, and then the cyanoacrylate composition is applied. These working methods are selected depending on the shape, size, etc. of the material part, and for efficiency of coating, it is preferable to use an automatic coating machine rather than manual coating. The acrylate composition used in the present invention is
The main component is a radically polymerizable (meth)acrylate monomer (acrylate monomer and/or methacrylate monomer is referred to as (meth)acrylate monomer herein), and organic peroxide polymerization initiation is added to this. and sulfur-based compounds other than sulfamides and/or as decomposition accelerators for organic peroxides.
Or it is a redox reaction system containing an aldehyde-amine reaction product. Representative examples of (meth)acrylate monomers used in the present invention include those shown in the following [] to []. [] Mono(meth)acrylate This is represented by the general formula below. However, R ₁ = H, CH ₃ R ₂ = H, C ₁ to C ₈ alkyl group,

【formula】

【formula】

[Formula] ―CH ₂ ―CH ₂ ―O―GH ₃ ― CH ₂ ―CH ₂ ―O―C ₂ H ₅ ,

【formula】

【formula】

[Formula] ― CH ₂ ―CH ₂ ―N (CH ₃ ) ₂ , ―CH ₂ ―CH ₂ ―N
( _{C2H5 )2 etc.} [] A compound having the structure of the general formula M-G-OH, where M = acrylic acid or methacrylic acid residue G = glycol residue [] Polyester poly(meth)acrylate For details, see JP-A No. 49-120889 It is as explained as "[]polyester polyacrylate and/or polyester polymethacrylate" in the publication. [] Polyol poly(meth)acrylate The details of this are as described as "[]polyhydric alcohol polyacrylate and/or polyhydric alcohol polymethacrylate" in JP-A-49-120889. [] Epoxy poly(meth)acrylate The details are as described in JP-A-50-9686 as "(2) Epoxy polyacrylate and/or epoxy polymethacrylate". [] Polyurethane poly(meth)acrylate The details of this product are as described in Japanese Patent Publication No. 12400/1983, and it is a compound represented by the following general formula. However, R ₁ = H, -CH ₃ R ₂ = divalent organic group selected from the group consisting of C ₁ to _{C 8} lower alkylene, phenylene, and naphthylene groups, X = -O-, and

[Formula] R is selected from H and C ₁ -C ₇ lower alkyl groups. B = substituted or unsubstituted alkyl,
alkenyl, cycloalkyl, aryl,
A polyvalent organic group selected from the group having aralkyl and heterocyclic groups. n=an integer of 2 to 6 The monomers shown above can be used alone or in combination of two or more as the main monomer component in the acrylate composition. The organic peroxides to be added to the acrylate compound are preferably those that act effectively during curing of the composition and do not impair storage stability; these include cumene hydroperoxide, 2,5-dimethylhexane, 2,5-dihydroperoxide, pinene hydroperoxide, paramenthane hydroperoxide, diisopropylbenzene hydroperoxide, tert-butyl hydroperoxide, benzoyl peroxide, methyl ethyl ketone hydroperoxide, dicumyl peroxide and so on. These organic peroxides may be used alone or in combination of two or more, but in either case, the amount added is based on the (meth)acrylate monomer.
0.1-10wt%, preferably 0.5-5wt%. If the amount added is too small, the curing reaction will be slow, which is impractical, and if it is too large, the performance will deteriorate and the storage properties will deteriorate, which is not preferable. The sulfur compound and/or aldehyde-amine reaction product used in the present invention is an organic peroxide decomposition promoter, and includes the following compounds. (1) Sulfur-based compounds other than sulfamides Thiourea, ethylenethiourea, acetylthiourea, tetramethylthiourea, mercaptobenzimidazole, 0-sulfobenzsulfimide, benzoylthiourea, etc. (2) Aldehyde-amine reaction product Preferred aldehyde-amine reaction products are:
1.0 aldehyde represented by the general formula R-CHO per 1 mole of the amine represented by the general formula R ₁ R ₂ NH
It is a product obtained by reacting ~3.5 mol, preferably 1.5 to 3.0 mol, according to a conventional method. In these general formulas, R ₁ is a C ₁ to C ₁₄ hydrocarbon group, R ₂ is H, a C ₁ to C 14 hydrocarbon group, and R is a C ₁ to C ₁₄ hydrocarbon group.
It is a group of _C8 hydrocarbons. Representative examples of combinations of aldehydes and amines in aldehyde-amine reaction products include the following. Formaldehyde-P-benzylaniline, acetaldehyde-benzylamine, butyraldehyde-butylamine, butyraldehyde-aniline, hydrominaldehyde-butylamine, naphthaldehyde-0-toluidine, heptaldehyde-N-allylaniline, etc. The amount of decomposition accelerator added is 0.1 to 10 wt%, preferably 0.5 to 5 wt% based on the (meth)acrylate monomer.
%. Polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, benzoquinone, and phenol derivatives can be added to the acrylate composition in order to improve its storage stability. These additives may be added in amounts generally used. For acrylate compositions, modifiers such as elastomers and silane compounds, and if desired, thermoplastic phenolic resins and their derivatives, or fillers are used to further improve impact resistance and peel adhesion strength. , an anti-aging agent, a coloring agent, etc. may be added. Compatible elastomers include NBR, chloroprene, polybutadiene, acrylic rubber,
SBR, urethane rubber, etc. are available, but unvulcanized ones are preferable in order to dissolve them uniformly in the (meth)acrylate monomer. The amount of the (meth)acrylate monomer added to the elastomer is preferably 0.5 to 50 wt%, more preferably 5 to 30 wt%. If the amount added is too small, the expected improvement in performance will not be observed, and if it is too large, the viscosity of the composition will increase and workability will deteriorate. Suitable silane compounds include vinyltrichlorosilane and α-methacryloxyalkyltrialkoxysilane. Since the acrylate composition of the present invention has a short pot life and poor long-term storage stability, the (meth)acrylate monomer is usually divided into two parts, one part is mixed with an organic peroxide, and the other part is mixed with an organic peroxide. Either add a decomposition accelerator to one side, or separate the composition consisting of (meth)acrylate monomer and organic peroxide from the decomposition accelerator or its solvent solution, and then mix it immediately before or at the time of use. It is preferable to form an acrylate composition and put it into practical use by a method in which both are mixed and then applied, or by a method in which both are brought into contact or mixed at the application site. The most desirable embodiment is a method in which the (meth)acrylate monomer is divided into two parts and the organic peroxide and the decomposition accelerator are separately blended. The cyanoacrylate composition, which is the other component of the two-component curable composition according to the present invention, contains a 2-cyanoacrylate monomer as a main component, and a stabilizer is added to this to improve storage stability. is used. In addition, if desired, a thickener,
Modifiers, plasticizers, colorants, etc. can also be added. The 2-cyanoacrylate monomer used in the present invention is represented by the following general formula. R=C ₁ to C ₈ alkyl, methoxyethyl,
Organic groups such as ethoxyel, benzyl, phenyl, cyclohexyl, 2-chloroethyl, hexafluoroisopropyl, trifluoroethyl, 2-cyanoethyl. As stabilizers, sulfur dioxide, sulfonic acids,
Saltone, lactone, boron fluoride, hydroquinone, hydroquinone monomethyl ether, catechol, pyrogallol, etc. are added at 1 to 1000 ppm. When a composition with added viscosity is required for the purpose of work, methyl methacrylate polymer, ethyl acrylate polymer, 2
- A few percent of cyanoacrylate polymer, acrylic rubber, etc. can be added. In addition, modifiers, plasticizers, colorants, etc. can be added as necessary. Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples. Parts in each example are parts by weight. Example 1 and Comparative Examples 1-2 100 parts of methyl methacrylate, a type of mono(meth)acrylate, glycidyl methacrylate
40 parts and 2-hydroxyethyl methacrylate 60, which is a type of compound represented by the formula M-G-OH
A solution (M ₁ ) prepared by dissolving 50 parts of nitrile rubber [product name Nitzpol 1042, manufactured by Nippon Zeon Co., Ltd.] in 100 parts of mixed monomer is divided into two parts, and cumene is added to 100 parts of one part (M ₁ ). A composition (A ₁ ) was prepared by uniformly blending 5 parts of hydroperoxide. A composition (B ₁ ) was prepared by uniformly blending 5 parts of methacrylic acid and 1 part of ethylenethiourea with 100 parts of the other (M ₁ ). On the other hand, as a cyanoacrylate composition, 2
-95 parts of methyl cyanoacrylate and 0.01 parts of sulfur dioxide
1 part, 0.05 part of hydroquinone, and 5 parts of methyl methacrylate polymer were uniformly dissolved. The adhesion test was conducted by the following method. Set time and tensile shear adhesive strength; Compliant with JISK6861-1977 "Test method for α-cyanoacrylate adhesives". Impact adhesive strength: Compliant with JISK6855-1973 "Impact adhesive strength testing method for adhesives". As a test piece, the material is iron S10C.
(JISG3102), whose surface was degreased with trichloroethane after sandblasting. First, equal amounts of the above-mentioned (A ₁ ) and (B ₁ ) are mixed as an acrylate composition, and this is applied around the joint surface of one test piece, and then the cyanoacrylate composition is applied to the other test piece. It was applied to the center of the joint surface of the test piece, and after applying finger pressure to both sides together, they were pressed together with a load of 500 g/6.25 cm ² . The adhesive strength was measured after being left at room temperature for 24 hours. The coating ratio of the acrylate composition to the cyanoacrylate composition was approximately 4:1. Further, as comparative examples, similar tests were conducted on acrylate compositions [mixture of equal amounts of (A ₁ ) and (B ₁ )] and cyanoacrylate compositions, each of which was adhered individually. The above test results are shown in Table-1. Example 2 and Comparative Examples 3 to 4 140 parts of acetyloxyethyl methacrylate, a type of mono(meth)acrylate, formula MG
A mixed monomer of 20 parts of 2-hydroxyethyl methacrylate, which is a type of compound represented by -OH, and 20 parts of trimethylolpropane triacrylate, which is a type of polyol poly(meth)acrylate, is mixed with butadiene-based synthetic rubber [product name JSR- 0080 manufactured by Japan Synthetic Rubber Co., Ltd.] A solution (M ₂ ) in which 60 parts of
A composition (A ₂ ) was prepared by uniformly dissolving 5 parts of tert-butyl hydroperoxide in 100 parts of one of the two (M ₂ ). A composition (B ₂ ) was prepared by uniformly blending 5 parts of methacrylic acid and 2 parts of benzylthiourea with 100 parts of the other (M ₂ ). On the other hand, as a cyanoacrylate composition, 2
-Ethyl cyanoacrylate 97 parts Sulfur dioxide 0.005
1 part, 0.05 part of hydroquinone monomethyl ether, and 3 parts of methyl methacrylate polymer were uniformly dissolved. The adhesion test was conducted in the same manner as in Example 1 and Comparative Examples 1 and 2, and the results shown in Table 1 were obtained.

【table】

[Table] Example 3 and Comparative Examples 5 to 6 2 moles of toluene diisocyanate and 2,2-
(P,P-dihydroxydiphenyl)-85 parts of a product, which is a type of polyurethane (meth)acrylate, obtained by reacting a reaction product with 1 mole of propane and 2 moles of hydroxyethyl methacrylate were mixed with polyurethane [Product name: Iron A solution (M ₃ ) in which 15 parts of Rubber M (manufactured by Nippon Oil Seal Co., Ltd.) was uniformly dissolved was divided into two parts, and 3 parts of cumene hydroperoxide was uniformly dissolved in 50 parts of (M ₃ ). A composition (A ₃ ) was obtained. A composition (B ₃ ) was obtained by blending 2 parts of methacrylic acid and 1 part of formaldehyde-P-benzylaniline compound, which is an aldehyde-amine reaction product, into 50 parts of the other (M ₃ ). On the other hand, as a cyanoacrylate composition, 2
- A homogeneous solution of 0.005 parts of sulfur dioxide, 0.03 parts of hydroquinone, and 3 parts of acrylic rubber in 97 parts of methyl cyanoacrylate monomer was used. The adhesion test was conducted as follows. The test piece consists of a cylindrical body with a diameter of 10 mmφ and a hole with a thickness of 10 mm in the center.
A shaft-fit assembly type member made of iron (SS-41 JISG3031) with a clearance of 5/100 mm was used, consisting of an annular body of mm. First, equal amounts of acrylate compositions (A ₃ ) and (B ₃ ) were mixed, applied to a cylindrical body of a test piece, and inserted into a fitting hole to assemble the member. Next, a cyanoacrylate composition was applied to the mating part, the set time was measured, and the composition was left at room temperature for 24 hours.
After standing for a period of time, the evacuation strength was measured using an Amsler type material testing machine at a loading rate of 10 mm/min. The coating amount ratio was acrylate composition:cyanoacrylate composition≈3:10. In addition, as a comparative example, either an acrylate composition [a mixture of equal amounts of (A ₃ ) and (B ₃ )] or a cyanoacrylate composition was applied to a cylindrical body in the same manner as above, and a member was assembled. The set time and evacuation pressure strength were measured. The results are shown in Table-2.

【table】

Claims (1)

[Claims] 1. One component is a redox-type acrylate composition consisting of a radically polymerizable (meth)acrylate monomer, an organic peroxide, a sulfur compound other than sulfamides, and/or an aldehyde-amine reaction product, and 2- A two-component adhesive composition, the other component of which is a cyanoacrylate composition comprising a cyanoacrylate monomer and a stabilizer.