JPS6063266A - Anaerobic adhesive and sealing agent composition for precoated bolt containing microencapsulated catalyst - Google Patents

Abstract

PURPOSE:The titled composition, obtsaned by dispersing a microencapsulated catalyst tertiary amine in a solution of a slightly volatile anaerobically curable methacrylate monomer, a catalyst benzoyl sulfimide, etc., and having improved storage stability, and useful for fastening tools, etc. for vehicles. CONSTITUTION:An anaerobic adhesive and sealing agent composition obtained by dispersing (B) 1-6wt% based on a component (i) microencapsulated catalyst aromatic tertiary amine, e.g. dimethylaniline, in (A) a solution prepared by dissolving (i) a slightly volatile anaerobically curable methacrylate monomer, e.g. triethylene glycol dimethacrylate, and (ii) a thermoplastic resin compatible with the monomer (i), e.g. polyvinyl butyral, preferably at 50:50 ratio, and dissolving (iii) catalyst benzoyl sulfimide in an organic solvent. In the process, the solvent is preferably adjusted to give about 300mu thickness of the coated and dried film.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a one-piece adhesive #ll composition. The composition includes a non-volatile methacrylate monomer, a thermoplastic resin that can be plasticized with the monomer, a non-adhesive film on the bolt, and a catalyst aromatic that prevents the bolts from blocking each other. Microcapsules of tertiary amine and benzoyl sulfimide catalyst are dispersed and dissolved in an organic solvent, preferably a hydrophobic organic solvent, and do not contain organic peroxides, which are polymerization initiators that are generally included in anaerobic adhesives. It is a composition.

Generally, in order for an anaerobic adhesive to have storage stability without gelling in the presence of air, the liquid composition must not gel even if it is left in the presence of air for 50 minutes at room temperature. It is commercially available as being stable for about 1 year. At the same time, there is no problem when applying this to soft steel or zinc chromate bolts, which is the object of the present invention, and immediately tightening them. When stored for a long time, the anaerobic adhesive will contact the iron ions that accelerate hardening, so that the film will not cause adhesive blocking during storage and transport. (Despite the presence of Y, it hardens in a short period of time, making it difficult to screw in the nut, loses adhesive strength, and does not exhibit sealing properties. Also, in the case of zinc chromate bolts, the catalyst of the anaerobic adhesive Since the system is a gold VB compound, it undergoes a chemical change in the presence of air, although the mechanism is not clear, and does not cure even when air is shut off, resulting in it not exhibiting adhesive sealing properties.This instability This anaerobic composition can be used as a liquid in the presence of air even when the strong catalytic aromatic tertiary amine and benzoyl sulfimide are used as a catalyst system, excluding organic peroxides that cause oxidation.
Even if it is stable for 10 days at 0°C, the coating applied to mild steel bolts will harden if left at 50°C for 4 to 5 hours. To avoid this, less active secondary amines are used, but they are unable to prevent the hardening of the bolt base material by iron ions, and zinc chromate bolts are difficult to harden and therefore exhibit low torque and adhesive sealing properties. do not have. Combining the catalyst system with the low φ term 2 and the low φ term 2 and the lower part of the catalytic system will result in a certain degree of stability, but the curing will be slow even if the adhesive is hardened. Low quality -'+---, e-break -.

Conventionally, in order to prevent bolts coated with anaerobic adhesives from stacking up on each other during storage, eliminating air and hardening before use, Tokuko Publication No. 45 Agent-11051 is an anaerobic adhesive containing a catalyst system. - A proposal has been made to encapsulate the entire acid in microcapsules and disperse the binder in the dissolved calcined solution, but this is not necessarily stable because the microcapsule film obstructs air entry. In order to improve this point, JP-A-50-151229 made microcapsules containing only methacrylate monomers and added thiosalcylic acid, which is nonvolatile like benzoyl peroxide, which is a solid organic peroxide that is nonvolatile in organic solvents. They suggest dispersing it in sodium paratoluene sulfinate plus a binder. However, both the core-based NISSO microencapsulation method using gelatin and the interfacial condensation polymerization method that forms a condensation polymerizable resin, and the microencapsulation method using urea resin or melamine resin as a film, have complicated manufacturing processes. Since the quality is not necessarily good, it is a direct price. Furthermore, all the microcapsules are not destroyed when tightening the bolts, making it even more economical. Therefore, in order to improve the HfM stability and avoid the increase in cost due to microencapsulation of the main components, the invention of JP-A No. 192426/1980 has partially added water as a binder to an anaerobic methacrylate monomer. A pre-coated bolt sealing/adhesive composition is proposed in which an emulsion of a soluble ethylene maleic anhydride copolymer is added and a polymerization initiator, an organic peroxide, encapsulated in microcapsules is added together with an accelerator. However, since the binder resin in this composition is an emulsion, the adhesive strength of this composition is weak and although it has sufficient adhesive strength for 1 bolt of soft bolt, it has insufficient adhesive strength for zinc chromate bolt, which lacks adhesiveness, and requires application drying. When trying to screw a nut into a pre-coated bolt, the coated film peels off and is pushed out to the outside of the nut, making it unable to stay in the gap between the bolt and nut. This problem has been solved by applying a composition containing an emulsion and a methacrylate monomer to the surface of the zinc chromate thread, which has been previously surface-treated with a silane coupling agent.

On the other hand, since the composition of the present invention is made by dissolving a thermoplastic resin in an organic solvent, it has sufficient adhesion and the dried film applied to zinc chromate does not peel off when a nut is screwed in, so pretreatment with a primer is not necessary. Microencapsulating a portion of the catalyst is economically more advantageous than microencapsulating the main component.

Bolts and nuts are used as tightening members in assembly processes such as the vehicle industry, and in the past, it was thought that a sealing function was sufficient, so pre-coated bolts made of alkyd resin as a main component were used. High performance requires improved heat resistance and adhesion in addition to sealing properties, and alkyd resins can only maintain sealing properties up to 80°C, whereas anaerobic adhesives can withstand heat up to 150°C. Because of its properties, it is non-adhesive and does not cause blocking even if the pre-applied material is stored and used as needed during assembly.Furthermore, despite the addition of the thermoplastic resin, it hardens for unknown reasons. The methacrylate is graft polymerized to the thermoplastic resin, or the interpolymer network for entanglement of the polymers has the same degree of heat resistance as the arylate cross-linked polymer, and the thermoplastic resin is heated. No decrease in heat resistance occurs.

That is, according to the present invention, if a nut is screwed into a bolt coated with the composition of 1. After being left at 150°C for 10 days, the bolt will not suffer thermal deterioration and will not undergo thermal deterioration if the destructive torque applied when loosening the nut is 1 lll after being left at 150°C for 10 days. The tearing torque at the time of application is not much different from the value immediately after application, and the tearing torque at the time of heating is only about 15% lower than the value at cooling.

Next, as the methacrylate single jh substance used in the present invention, polyalkylene gelicol dimethacrylate, which is hardly volatile, and among them, triethylene glycol dimethacrylate and tetraethylene glycol dimethacrylate are preferable, and trimethylol dimethacrylate is preferable. Propane trimethacrylate, glycerin dimethacrylate, glycerin trimethacrylate, polypropylene glycol dimeta 1,6-hexanesiol dimethacrylate, neopentylguhar monomethacrylate, 2-hydroxypropylene monomethacrylate are high It gives a torque composition, but since ethylene glycol dimethacrylate, dietereglycol dimethacrylate, and butylene glycol dimethacrylate have high C volatility, if the coated bolt is stored for a long period of time, the monomer will volatilize. Although it is suitable, there is no problem if it is mixed in a small amount or used for a short time after application and drying.

Next, the thermoisoplastic resin plasticized with the above-mentioned methacrylate monomer is compatible with the methacrylate monomer, and the plasticized film does not cause adhesion blocking with each other during storage and transportation of coated bolts, and is compatible with metals. These are types that have adhesive properties and do not separate when screwed into a nut, and do not impair the stability of methacrylate monomers, such as polyacrylate polymers and their copolymers, polyvinyl butyral,
Cellulose esters, particularly cellulose acetate, are preferred. It is desirable to appropriately mix several types of them in order to balance adhesiveness and non-adhesiveness. Next, the mixing ratio of methacrylate monomer and thermoplastic resin +, t20:80
A ratio of 80:20 to 50:50 (7) is preferable in view of the balance between torque and non-stick properties.

Examples of the catalytic aromatic tertiary amines to be encapsulated in microcapsules include dimethylaniline, dimethylp-toluidine, diethylaniline, diethylp-toluidine, N-
Ethylbenzylaniline.

Jetanolaniline, tetramethyldiaminodiphenylmethane.

These medium solid amines such as leuco crystal violet are dissolved in heat-linkable high-boiling solvents or liquid aromatic amines and then microencapsulated. The membrane material for the microcapsules is gelatin, urea resin, melamine resin, etc., and is produced by commonly known methods such as coacservation method or interfacial polymerization method. The appropriate blending ratio of the methacrylate monomer is 1 to 6%.

Next, the catalyst benzoyl sulfimide added to the above dC composition is 0.5 to 3% based on the monomer methacrylate, and the stabilizer hydroquinone-substituted phenols and oxalic acid are added at 100%
~200 PPM is suitable.

Further, as the solvent to be used, a hydrophobic solvent that does not easily lead the aromatic tertiary amine in the microcapsules out of the capsule is suitable, such as toluene, xylene, and triclene among halogenated hydrocarbons, among others. The proportion of the solvent is adjusted so that the viscosity of the coated and dried film is about 300μ.

Next, the application method is dipping, spraying, etc. to apply F to the bolts.
However, it is appropriate to apply it.

Degreased MloxPl, 5 mild steel bolts and zinc chromate bolts were immersed in the composition of the present invention, pulled up, and then dried and cooled at 50° C. for 1 hour. Next, the coated bolt nut is screwed in until it comes into contact with the head of the bolt, and the torque required for this is taken as the consumed torque. In this case, the tightening torque is OIC4
-cm, and after being left at this volt f temperature for 24 hours.

The torque used when the relative position of the nut and bolt head moves when loosening the nut, and this is further processed/4
The torque required to return the rotation is the escape torque.

Next, screw in the nut, apply λσ, put the bolt in a constant temperature bath at 50℃, leave it for a specified number of days, cool it, screw in the nut at room temperature, measure the torque consumption, and then leave it at room temperature for 24 hours. and escape torque are measured and compared with the respective values immediately after application to evaluate stability. This test was conducted on the compositions of each example below, and it was found that in the case of soft 1 bolt, it was 4 to 5 days, and in the case of zinc chromate bolt, it was 10 days or more.
0 drop is also small, /4 to 5 for PH1 volt
This shows that zinc chromate bolts are stable even when stored at temperatures of 11' for about one year.

On the other hand, when the aromatic tertiary amine is directly added without being encapsulated in microcapsules, the liquid composition is stable without gelling for 10 days at 50°C in the presence of air, but it is
・Applied to 1 volt i & 50℃, Luk is 30 to 10 V
, or even more than that, it becomes obvious that the scraps used to screw the nut harden and the screwing becomes difficult, and the contact force decreases significantly and the breaking torque becomes significantly lower.

Example 1,1 Tetraethylene glycol dimethacrylate (molecule 'M, 330) 100 parts Hydroquinone monomethyl ether 0.01 #Oxalic acid o, o it
t Dimethyl para-toluidine microcapsule 30 Benzoyl sulfimide 1. OI Cellulose acetate (CAB551.0.01 made by Istman Kodak Co., Ltd.) 50 parts Polyacrylate tree Hr1 (Dyanal BR-8Q made by Mitsubishi Rayon Co., Ltd.) 5 o Toluene 170 Example 2. Tetraethylene glycol dimethacrylate (molecular weight 330) 100 parts Hydroquinone 0.012 # Oxalic acid 0.01 part Dimethyl para-toluidine microcapsules 3.07 Penzoyl sulfimide 1.0 Cellulose acetate butyrate (CAB・500・5 100# (manufactured by Eastman Kodak Co., Ltd.) Triclean 480〃 Example 3. Tetraethylene glycol dimethacrylate (molecular weight 330) 100 parts Hydroquinone dimethyl ether 0.015 N oxalic acid 0.01 // Tetramethyldiaminodiphenylmethane microcapsules (25% α-methyl-naphthalene solution) 10 Acetate butylene rW fiber cord ( CAB500-5 Istoman Kodatsu'M) 50 #Polyacrylate resin (Titanal BR-89 manufactured by Mitsubishi Rayon Co., Ltd.) 50 Toluene 45
0. Example ζ Triethylene glycol dimethacrylate (molecular weight 286) 100 parts Hydroquinone monomethyl ether 0.015 N oxalic acid 0.01# Dimethyl para-toluidine microcapsules 3.0 Benzoyl sulfimide 1. o Vinegar (TMJ acid fiber ml (CAB551-0.01 Istman Kodatsu W) 501 Polyacrylate resin (Dyanal BRso manufactured by Mitsubishi Rayon Co., Ltd.) 5o Silica powder 5ON Toluene 180 Lr Example 5. Tetraethylene Glycol dimethacrylate (molecule ff1330) 100 parts Hydroquinone 0
．． 015 N Oxalic acid 0.01 Benzoyl sulfimide 1.0 Dimethylaniline microcapsules 3. CI polyvinyl butyral resin (S-LEC 1007riL8 manufactured by Sekisui Chemical Co., Ltd.) 100 parts Silica powder 12o Ezyl acetate E9o Example 6. Trimedylolpropane trimethacrylate (molecule ff1338) 100M hydroquinone
0.015 // i1 customer r11 0.01# benzoyl sulfimide 1. o Dimedyl para-toluidine microcapsules 3.0/1
Acetic acid r@Acid fiber a (CAB500.5 Istman Kodatsu Co., Ltd.) 100〃Silica powder 5o〃Trichlene -43o〃

Claims (1)

[Scope of Claims] 1. In a solution of a refractory anaerobic curable methacrylate monomer, a thermoplastic resin compatible with the monomer, and a catalyst penzoyl sulfimide in an organic solvent, An anaerobically curable precoated Bolton Al and adhesive composition containing an encapsulated catalytic aromatic tertiary amine dispersed therein and no FFI polymerization initiator or organic peroxide. 2. The composition according to claim 1, wherein the thermoplastic resin is a thermoplastic polymer that is compatible with the methacrylate monomer so that the applied and dried bolts do not stick to each other, or a fiber cord ester or a mixture thereof. . 3. A pre-coated bolt coated with the composition of claim 1.