JPH05295339A - Aqueous adhesive composition - Google Patents

Abstract

PURPOSE:To obtain a microcapsuled aqueous adhesive composition for locking which is used by coating the screw thread of a threading member, wherein the microcapsules are firmly fixed onto the screw thread and the wall film is in a dry state so that it has no stickiness and causes no environmental pollution. CONSTITUTION:This composition composed of a dispersion of a self-emulsifiable epoxy resin, an epoxy resin curing agent and a microcapsuled adhesive in water, wherein the microcapsuled adhesive is composed of (i) a wall film made of an aldehyde resin or urea resin and (ii) an epoxy adhesive or acrylic adhesive as the core material contained in the wall film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microcapsule type water-based adhesive composition which is applied to a screwing surface of a screwing member such as a screw, a bolt or a nut so as to prevent loosening or to provide adhesion.

[0002]

2. Description of the Related Art As a micro-capsule type adhesive for locking which is applied to a screwing surface of a screwing member such as a screw, bolt or nut, a microcapsule containing a solvent composed of an organic solvent or water and a reactive adhesive has been conventionally used. A composition containing a capsule and a binder composed of various resins is known. (See JP-B-45-11051, JP-B-52-46339, JP-A-2-308876, JP-A-53-11883)

[0003]

However, when the binder of the above-mentioned microcapsule type adhesive is a resin solution, the adhesive force for fixing the microcapsules to the screwing surface is weak, so that the microcapsules are distributed or when the screwing member is used. There was a defect that the microcapsules would peel off from the screwed surface when tightened.

Further, an acrylic resin is used as the resin,
In the emulsion type in which this is dispersed with a surfactant or the like, dispersion of the curing agent for the adhesive encapsulated in the capsule in the emulsion impairs dispersion stability and increases the viscosity.

Further, when the capsule wall film is made of polyvinyl alcohol or gelatin, the performance of the microcapsule type adhesive is deteriorated due to swelling with water or the like. For this reason, an organic solvent is used in this type of microcapsule type adhesive, but this not only pollutes the environment but also adversely affects the health of the worker during the operation of applying the microcapsule type adhesive to the screw member.

Therefore, an object of the present invention is that the microcapsule type adhesive is firmly fixed to the screwed surface, the wall film is in a dry state, is not sticky, and does not cause environmental pollution. It is an object of the present invention to provide a microcapsule type water-based adhesive composition in which the drawbacks existing in the technology are improved.

[0007]

According to the present invention, the above object is obtained from an aqueous dispersion of (a) a self-emulsifying epoxy resin, (b) an epoxy resin curing agent, and (c) a microcapsule type adhesive. The microcapsule type adhesive is (i) a wall film made of an aldehyde resin or a urea resin, and (ii) an epoxy adhesive or an acrylic adhesive as a core material enclosed in the wall film. This is achieved by a water-based loosening-preventing adhesive composition that is applied to the threaded surface of the threaded member.

[0008]

DETAILED DESCRIPTION OF THE INVENTION The self-emulsifying epoxy resin used in the present invention is a polyglycidyl ether of a polyhydric alcohol, a polyglycidyl ether of a polyhydric phenol derivative,
Examples thereof include polyglycidyl ester of polycarboxylic acid.

Examples of polyhydric alcohols are ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, polyoxypropylene glycol, 1,3-propylene glycol, 1,4-
Butylene glycol, 1,5-pentanediol, 1,2,6
-Hexanetriol, glycerol, bis- (4-hydroxycyclohexyl) -2,2-propane and the like.

Examples of polyvalent phenols are resorcin, hydroquinone, 2,2-bis- (4-hydroxyphenyl) -propane (bisphenol A), a mixture of isomers of dihydroxydiphenylmethane (bisphenol) and tetra. Bromobisphenol A, 4,4'-dihydroxydiphenylcyclohexane, 4,4'-dihydroxy-3,3'-dimethyldiphenylpropane, 4,4'-dihydroxydiphenyl, 4,4'-dihydroxybenzophenol, Bis- (4-hydroxyphenyl) -1,1'-
Ethane, 4,4'-dihydroxybenzophenol, bis- (4-hydroxyphenyl) -1,1'-isobutane, bis- (4-hydroxy-tert-butylphenyl) -2,2 '
-Propane, bis- (2-hydroxynaphthyl) -methane, 1,5-dihydroxynaphthalene, tris- (4-hydroxyphenyl) ether, bis- (4-hydroxyphenyl) ether, bis- (4-hydroxyphenyl) And chlorinated or brominated products of the above compounds.

Examples of polycarboxylic acids are oxalic acid,
Examples include succinic acid, adipic acid, glutaric acid, phthalic acid, terephthalic acid, hexahydrophthalic acid, and 2,6-naphthalenecarboxylic acid. The above-mentioned polyhydric alcohol, polyhydric phenol, and polycarboxylic acid for modifying the epoxy resin into a self-emulsifying epoxy resin are known, and the present invention is not limited to the above types.

Further, the dispersion solvent in the present invention may be either water alone or a mixed system of water and an organic solvent such as alcohols. Further, in order to promote dispersion of the self-emulsifying epoxy resin in water, a surface active agent is used. The agent may be added up to 10% by weight based on the weight of the self-emulsifying epoxy resin.

The epoxy resin curing agent used in the present invention is a basic curing agent such as polyalkylene amines, alicyclic amines, araliphatic amines, Mannich bases, addition products of polyepoxide and polyamine, and the like. , Polycarboxylic acids, acid anhydrides, acidic curing agents such as phenols, and condensation products of aldehydes.

As the above-mentioned polyalkyleneamines, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, 2,2,4- or 2,4,4-trimethylhexamethylenediamine, bis- (3-aminopropyl) methylamine , 1,4-bis- (3-aminopropyl) -piperazine, N, N-bis- (3-aminopropyl) ethylenediamine and the like.

The alicyclic amines include 1,2- or 1,
3-diaminocyclohexane, 1,4-diamino-3,6-
Diethylhexane, 1,2-diamino-4-ethylcyclohexane, 1,4-diamino-3,6-diethylcyclohexane, 1-cyclohexyl-3,4-diaminocyclohexane, isophoronediamine, 4,4'-diaminodicyclohexylmethane, 4,4'-diaminodicyclohexylpropane, 2,2'-bis- (4aminocyclohexyl) propane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 3-amino-1-cyclohexaneaminopropane, 1 , 3- or 1,4-bis- (aminomethyl) -cyclohexane.

The araliphatic amines include xylene diamine or hydrogenated products thereof.

As the Mannich base, there are condensation products of aldehydes and phenols in polyamines.

The addition products of polyepoxy and polyamine include polyepoxy compounds such as terminal epoxide compounds, polyglycidyl ethers and polyglycidyl esters, and ethylenediamine, hexamethylenediamine, m-
It is an addition reaction product with a diamine such as xylenediamine or a polyamidoamine.

Examples of the polycarboxylic acid include cyclopentanecarboxylic acid, butanetetracarboxylic acid, cyclobutanetetracarboxylic acid, aconitic acid, citric acid, and acid esters having free COOH of polyhydric alcohol and polycarboxylic acid.

Examples of the phenols include resoles, formaldehyde-phenol carboxylic acid resins and etherified phenol resin resoles.

Other acidic curing agents include p-toluenesulfonic acid, cyclohexanesulfamic acid and acidic butyl phosphate, which can be used in combination with an amine type curing agent.

As the aldehyde condensation products, amine aldehyde resins of amines and aldehydes, melamine resins of melamine and aldehydes, urea resins of urea and aldehydes, acetoguanamine resins of acetoguanamine and aldehydes, etc. There is.

As the wall film of the microcapsule used in the present invention, an aldehyde resin or a urea resin is used. Examples of the aldehyde resin include urea-formaldehyde resin and melamine-aldehyde resin, and examples of the urea resin include polyurea and polyurethane. These wall membranes have the property of being non-swelling and impermeable to water.

The reactive adhesive contained in the microcapsules used in the present invention is an epoxy adhesive or an acrylic adhesive. In the epoxy adhesive, the epoxy compound is encapsulated in microcapsules, and the amine compound as the curing agent is preferably a water-insoluble solid, which is used by dispersing it in the binder composition described above. In the acrylic adhesive, acrylic monomers or oligomers are encapsulated in microcapsules. The peroxide, which is a curing agent, may be used by dispersing it in the above-mentioned binder or encapsulating it in microcapsules.

Further, in the present invention, a colorant, a filler, an antifreezing agent, an adhesion imparting agent, a dispersant and the like may be added for convenience.

[0026]

In the present invention, since the binder is a self-emulsifying epoxy resin, the microcapsule is firmly fixed to the screwed surface by the adhesive force of the epoxy resin, and the coating film of the microcapsule type adhesive applied to the screwed surface. Is a dry film and has no surface stickiness. Therefore, it does not come off during the distribution process of the screw member. Further, even when the screwing member is tightened, the microcapsule type adhesive does not come off and the microcapsule type adhesive easily enters the screwing surface such as the bolt and the nut. The reactive adhesive contained in the microcapsules is crushed and the adhesive force is more effectively exerted on the screwing surface.

Unlike the resin emulsion in which the self-emulsifying epoxy resin is emulsified by the dispersing effect of the surfactant, it does not contain a surfactant and therefore does not aggregate even if an ionic compound or the like is mixed. Therefore, the aqueous adhesive composition of the present invention is also characterized by excellent storage stability.

[0028]

EXAMPLES OF THE INVENTION The following Examples 1-5 and Comparative Examples 1-3
Samples of each formulation shown in 1 were prepared. In these formulations, parts indicate parts by weight.

[0029]

Example 1 * Epicoat 828-encapsulated capsule 100 parts (encapsulation rate 70%, urea formalin wall film) * 1.3 DPP (hardener) 20 parts * Self-emulsifying epoxy resin 22 parts (EP122 (Hoechst synthesis)) * Self-emulsifying epoxy Resin curing agent 28 parts (EH-623 (Hoechst synthesis)) * Pure water 100 parts

[0030]

Example 2 * Epicoat 152 encapsulation capsule 100 parts (encapsulation rate 70%, urea formalin wall film) * Hexamethylenediamine (curing agent) 30 parts * Self-emulsifying epoxy resin 22 parts (EP122 (Hoechst synthesis)) * Self-emulsifying Epoxy resin curing agent 28 parts (EH-623 (Hoechst synthesis)) * Pure water 100 parts

[0031]

Example 3 * Capsule Bisphenol dimethacrylate (BPE-4, Shin-Nakamura Chemical) 94 parts Neopentyl glycol diacrylate 18 parts Benzoyl peroxide 2 parts (encapsulation rate 70%, urea formalin wall film) 100 parts * TSA 4 parts * Calcium carbonate 20 parts * Self-emulsifying epoxy resin 22 parts (EP122 (Hoechst synthesis)) * Self-emulsifying epoxy resin curing agent 28 parts (EH-623 (Hoechst synthesis)) * Pure water 100 parts

[0032]

[Example 4] * Capsule bisphenol dimethacrylate (BPE-2.6, Shin-Nakamura Chemical) 98 parts Benzoyl peroxide 2 parts (encapsulation rate 70%, urea formalin wall membrane) 100 parts * Thiosalicylic acid 4 parts * Calcium carbonate 10 parts * Titanium dioxide 10 parts * Self-emulsifying epoxy resin 22 parts (EP122 (Hoechst synthesis)) * Self-emulsifying epoxy resin curing agent 28 parts (EH-623 (Hoechst synthesis)) * Pure water 100 parts * Defoaming Agent 0.5 parts * Methanol 2 parts

[0033]

[Example 5] * Peroxide microcapsule (benzoyl peroxide 100 parts) 10 parts (encapsulation rate 70%, urea formalin wall membrane) * Monomer capsule bisphenol dimethacrylate (BPE-2.6, Shin-Nakamura) Chemistry) 80 parts Neopentyl glycol diacrylate 20 parts (encapsulation rate 70%, urea formalin wall film) 100 parts * Hydroxyethyl methacrylate 5 parts * Hydroxypropyl methacrylate 10 parts * Silica-based filler 5 parts * 2 Titanium oxide 10 parts * Self-emulsifying epoxy resin 22 parts (EP122 (Hoechst synthesis)) * Self-emulsifying epoxy resin curing agent 28 parts (EH-623 (Hoechst synthesis)) * Pure water 100 parts * Defoamer 0.5 part * Methanol 2 parts * Anti-corrosion agent 0.5 parts

[0034]

[Comparative Example 1] * Epicoat 828 encapsulation capsule 100 parts (encapsulation rate 70%, urea formalin wall membrane) * 1.3 Dipiperidyl propane 20 parts * Polyvinyl alcohol (20% solution) (binder) 50 parts * Flat silica 5 Part * Pure water 100 parts

[0035]

Comparative Example 2 * Epicoat 828-encapsulated capsule 100 parts (encapsulation rate 70%, urea formalin wall membrane) * 1.3 Dipiperidyl propane 20 parts * Aqueous emulsion resin (trade name Primalun-580-S Nippon Acrylic Chemistry) ( Binder) 50 parts * Flat silica 5 parts * Pure water 100 parts

[0036]

Comparative Example 3 * Epicoat 828-encapsulated capsule 100 parts (encapsulation rate 70%, gelatin wall film) * 1.3 DPP 20 parts * Self-emulsifying epoxy resin 22 parts (EP122 (Hoechst synthesis)) * Self-emulsifying epoxy resin curing agent 28 Part (EH-623 (Hoechst synthesis)) * 100 parts pure water

[Test Method] Each sample of the above Examples 1 to 5 and Comparative Examples 1 to 3 (adhesive composition) was applied to a bolt having a diameter of 10 mm.
Was applied and air dried to prepare a test piece. The test piece was fastened to a female screw with an inner diameter of 10 mm with a torque of 300 kgf-cm. After leaving the microcapsules to stand for a predetermined time to cure the adhesive, the return torque when the test piece was loosened was measured. The results are shown in Table 1.

[0038]

[Table 1]

[0039]

As shown in Table 1 above, in Examples 1 to 5 of the present invention, compared with Comparative Examples 1 to 3, the microcapsule type adhesive is firmly fixed to the screwed surface and tightened. Capsules do not fall off during filling, and the wall film is in a dry state without stickiness and does not thicken during compounding. Also,
In the present invention, since an organic solvent is not used as a solvent and pure water is used, it does not cause environmental pollution and is safe from the viewpoint of work hygiene.

Claims (2)

[Claims] 1. An aqueous dispersion of (a) a self-emulsifying epoxy resin, (b) an epoxy resin curing agent, (c) a microcapsule type adhesive, wherein the microcapsule type adhesive is (i) an aldehyde-based adhesive. A wall film made of a resin or a urea resin, (ii) applied to the screwing surface of a screwing member which is included in the wall film and is made of an epoxy adhesive or an acrylic adhesive as a core material. A water-based adhesive composition for loosening prevention used. 2. The aqueous adhesive composition according to claim 1, wherein the self-emulsifying epoxy resin is polyglycidyl ether of polyhydric alcohol, polyglycidyl ether of polyhydric phenol derivative, or polyglycidyl ester of polycarboxylic acid.