JPS6013868A - Pressure-sensitive adhesive composition having anaerobic curability - Google Patents

Abstract

PURPOSE:To obtain the titled composition having excellent curability and adhesivity, and suitable as a pressure-sensitive adhesive tape and prepreg, by adding a specific metallic compound to a pressure-sensitive adhesive composition containing a (meth)acryloyl-containing oligo(meth)acrylate, a rubbery polymer, etc. CONSTITUTION:The objective composition can be produced by mixing (A) a (meth)acryloyl-containing oligo(meth)acrylate [e.g. epoxy-(meth)acrylate] with (B) a polymer which is rubbery at normal temperature [e.g. rubber having (meth)acryloyl group at the side chain], (C) a curing catalyst comprising an organic hydroperoxide, and (D) one or more compounds soluble in an organic solvent and selected from preferably organic Co, Fe, Mn and Mo compounds (e.g. an octylic acid salt). The amount of the component D is preferably 0.01ppm-1wt% based on the sum of the components A and B. EFFECT:Uniform curability. Applicable also to a nonmetallic material.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an adhesive composition having anaerobic curability suitable for adhesive tapes or prepregs.

Although a wide variety of proposals have been made regarding anaerobic curable adhesives, there are few proposals regarding adhesive compositions for adhesive tapes or prepregs. -For example,
For example, adhesive compositions are known in which necessary components such as hydroperoxides, aromatic tertiary amines, and stabilizers are added to liquid oligoacrylates. Nonwoven fabrics are impregnated with this adhesive composition to form prepregs. Attempts have been made to manufacture and use it in backings.

However, this prepreg does not exhibit so-called stickiness,
Most importantly, the curing speed of the composition is not practical, and especially when the composition layer becomes thick, it is difficult to cure. Therefore, even if sufficient pressure can be applied and the thickness of the composition layer can be made constant, such as with backings, it is difficult to cure the composition with just a finger pressure.

Furthermore, the objects to be bonded are limited to metals, particularly iron and copper products, and it is difficult to use it for other materials, so it has not been used industrially to date. However, when applied to adhesive tape or prepreg, it retains its original adhesiveness, is used as an adhesive tape or prepreg before use, and cures after adhesion, dramatically improving adhesive strength, and can be applied to various materials. If a pressure-sensitive adhesive composition that can be used for this purpose were to appear, it is thought that there would be a wide variety of uses for pressure-sensitive adhesive tapes or prepregs using this pressure-sensitive adhesive composition.

The present inventors have conducted various studies on adhesive compositions having anaerobic curability suitable for adhesive tapes or prepregs, regardless of the object to be bonded, from the above-mentioned viewpoints. (1) An oligo(meth)acrylate having one or more acryloyl group and/or methacryloyl group in one molecule, (11) a polymer that is rubbery at room temperature, and (iii)
It has been found that a composition containing organic hydroperoxides can achieve this purpose and has already been proposed. However, this composition had problems in that it required time to cure and was likely to cause variations in curing, and was not necessarily satisfactory.

However, as a result of further research, the present inventors found that by further blending at least one compound selected from a cobalt compound, an iron compound, a manganese compound, and a molybdenum compound soluble in an organic solvent to the three components, ,
Knowing that satisfactory results could be obtained, the present invention was completed.

That is, the present invention provides (A) oligo(meth)acrylates having one or more acryloyl groups and/or methacryloyl groups in one molecule, (B) polymers that are rubbery at room temperature, (C) organic hydroperoxides, and (D) an adhesive composition having anaerobic curability, characterized in that it contains at least one compound selected from a cobalt compound, an iron compound, a manganese compound, and a molybdenum compound that are soluble in an organic solvent. Regarding.

By blending such a specific metal compound, (1)
The curing speed of the adhesive composition can be accelerated. It is possible to cure even difficult adhesive compositions with a thickness of 50μ or more, (iv) it is possible to bond objects other than metals, and (V) the adhesive strength is high. , its practicality is great.

In the present invention, an oligo(meth)acrylate having one or more acryloyl group and/or methacryloyl group in one molecule [hereinafter referred to as
The following types of oligo(meth)acrylates can be mentioned.

(1) Vinyl ester resin (epoxy (meth)acrylate) An oligomer having one or more acryloyl group and/or methacryloyl group in one molecule obtained by heating and reacting an epoxy resin with acrylic acid or methacrylic acid. (Meth)acrylates, - Examples include:

H2 Typical epoxy resins include homologs of bisphenol A diglycidyl ether type with different molecular weights, polyglycidyl ethers of novolak, polyglycidyl esters of polybasic acids, and epoxy resins obtained by oxidizing intramolecular double bonds with peracetic acid. It can be cited as something.

The reaction is carried out in the presence of a catalyst such as a tertiary amine, a secondary or tertiary amine salt, or a quaternary ammonium by heating at 150° C. or lower in air.

In order to use a vinyl Nisder resin in the present invention, it is not necessarily necessary to use a monomer together, but when using a viscous J agent composition with anaerobic curability, for example, in a prepreg type, it is also possible to use a monomer in combination. ((ii) The same applies to the following oligo (meta) acrylic (/-))
.

(11) Polyester (meth)acrylate An oligo(meth)acrylate synthesized by combining acrylic acid or methacrylic acid with any polybasic acid or polyhydric alcohol, examples of which include the following: .

During condensation, an acid catalyst is generally used, and by-produced water is removed by azeotropic distillation with an organic solvent.

H2C-C-C-0 ■ l-l3 Apart from the above, it can also be synthesized by transesterification using acrylic esters and methacrylic esters. Specific examples include those having the following structure.

C=O CI-ICH2 Polybasic acid or its acid anhydride, polyhydric alcohol,
There is no need to impose any particular restrictions on Nisdel polybasic acids.

(iii) Boron-(meth)acrylate Obtained by reacting an unsaturated alcohol, a polyhydric incyanate compound, a polyhydroxyl compound, or a polyhydroxyl polymer that shares a hydroxyl group and an acryloyl group or a methacryloyl group in the same molecule. , is an oligoacrylate having one or more acryloyl group and/or methacryloyl group in the molecule, and specific examples include the following.

ONCO H3 unsaturated alcohols include 2-hydroxy-ethyl acrylate, 2-hydroxyprobyl acrylate,
Examples include 2-hydroxy-propyl methacrylate and 2-hydroxy-ethyl methacrylate.

Examples of incyanate compounds include tolylene diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate, inphorone diisocyanate, 1,5-naphthylene diisocyanate, partial adducts of these with polyhydric alcohols (incyanate group remaining type), polyhydric Examples include polyisocyanates derived from phenol.

Examples of the polyhydroxyl compound or polyhydroxyl polymer include hydroxyl polyesters, polyethers, polymers having hydroxyl groups in side chains, and polyhydric alcohols.

aφ spiroacetal-(meth)acrylate (11
1) An oligo(meth) having a spiroacetal structure in its molecular structure obtained by reacting the same unsaturated alcohol, polyhydroxyl compound or polyhydroxyl polymer as mentioned above with diarylidene pentaerythritol.
The oligo(meth)acrylate mentioned above is an acrylate, and the simplest structure is shown by the following formula:
It is preferable that the molecular weight is 200 or more. molecular weight is 2
If it is less than 0.00, it will be volatile and will be disadvantageous in imparting tackiness.

Examples of polymers that are rubbery at room temperature and are used as components (,, B) in the present invention include those having a glass transition temperature of 0° C. or lower.

Polymers that are rubbery at room temperature include (1) methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and 2-ethylhexyl methacrylate. , nonyl methacrylate,
Decyl methacrylate, acrylonitrile, vinyl acetate,
A polymer obtained by polymerizing at least one monomer selected from vinyl propionate, butadiene, styrene, and ethylene that exhibits a rubber-like shape upon polymerization, (2) at least one of the above monomers and an acryloyl group in the side chain. or a monomer having a functional group for introducing a methacryloyl group, such as selected from maleic anhydride, acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, and 2-hydroxypropyl methacrylate. (3) in the presence of the polymer of (2), 2-hydroxyethyl (meth)acrylate, 2-
Such as hydroxypropyl (meth)acrylate (
Alcohols having a (meth)acryloyl group, epoxy compounds having a (meth)acryloyl group such as glycidyl (meth)acrylate, adducts of tolylene diisocyanate and 2-hydroxypropyl methacrylate, 1. Adducts of isophorone diisocyanate and hydroxyethyl acrylate Examples include polymers having an acryloyl group or a methacryloyl group in the side chain obtained by reacting a (meth)acryloyl group such as an adduct with an unsaturated incyanato compound having an incyanato group.

Examples of the rubbery polymer having an acryloyl group or methacryloyl group in the side chain in (3) above include the following.

(a) It is obtained by reacting a polymer having an acid anhydride structure with an alcohol having an acryloyl group or a methacryloyl group, and specific examples include the following nine.

(b) It is obtained by reacting a polymer having a carboxyl group in its structure with an epoxy compound having an acryloyl group or a methacryloyl group, and specific examples include the following.

(c) An unsaturated isocyanate containing an incyanato group and an acryloyl group or a methacryloyl group in the molecule in a polymer having a hydroxyl group in the structure. It is obtained by reacting compounds, and specific examples include the following.

A rubber-like polymer having an acryloyl group and/or a methacryloyl group in the side chain of CH2 or higher can be obtained by, for example, synthesizing the basic polymer by solution polymerization, and then carrying out a reaction to introduce an acryloyl group or a methacryloyl group into the side chain in the solution state. You can get it by doing it.

The polymer, which is rubbery at room temperature, is the main material that imparts tackiness to the pressure-sensitive adhesive composition. Furthermore, the fact that the polymer, which is rubbery at room temperature, has an acryloyl group and/or a methacryloyl group in its side chain imparts anaerobic curability to the polymer itself.

The blending ratio of the polymer, which is rubbery at room temperature, and the aforementioned oligo(meth)acrylate varies widely depending on the form of the required adhesive material, such as an adhesive tape or prepreg, and the properties of the adhesive composition.

For example, when an adhesive composition is used for a banking material, etc., oligo(meth)acrylate is the main amount, and the polymer, which is rubbery at room temperature, acts as a viscosity-imparting agent. In this case, on the other hand, the polymer, which is rubbery at room temperature, is the main amount, and the oligo(meth)acrylate acts as an adhesion agent.

Considering these factors, the practical mixing ratio of the two is 5% to 95% rubbery polymer at room temperature, oligo(
The content of meth)acrylate is preferably 95% or less and 5% or more.

In the present invention, organic hydroperoxides (as component Q) are used as curing catalysts. Examples of organic hydroperoxides include tertiary-butyl hydroperoxide, cumene hydroperoxide,
Diisopropylbenzene hydroperoxide, paramenthane hydroperoxide, 2,5-dimethylhexane-
Examples include 2,5-dihydroperoxide and 1,1,3.3-tetramethylbutyl hydroperoxide. The blending amount of organic hydroperoxides is 10% of the total amount of oligo(meth)acrylate and polymer that is rubbery at room temperature.
It is 0.1 to 10 parts by weight per 0 parts by weight.

If it is less than 0.1 part by weight, it is not sufficient to promote anaerobic hardening, and if it is added in excess of 10 parts by weight, the hardening promoting effect corresponding to the amount added cannot be obtained.

The compounds of cobalt, iron, manganese, and molybdenum used as zero components in the present invention include those that are soluble in organic solvents, preferably soluble in organic solvents, and oligo(meth)acrylates and/or Examples include those that are soluble in rubbery polymers at room temperature. Although both organic and inorganic components can be used as the zero component, organic components are preferred.

Examples of organic compounds include cobalt, iron, manganese, or molybdenum salts of oil-soluble C3 or higher carboxylic acids such as retic acid, naphthenic acid, lauric acid, oleic acid, and rosin.

Cobalt, iron, manganese or molybdenum salts of lower carboxylic acids such as acetic acid, acrylic acid, methacrylic acid, etc. have poor solubility in organic solvents, and are rather water-soluble, and therefore are not necessary for the present invention.

Other examples include metal chelate compounds such as acetylacetonate of iron, cobalt, manganese or molybdenum, which are preferably used as an acidic alkyl phosphate solution.

The above-mentioned component 0 of the present invention makes no difference 9) even when used in combination with other metal organic acid salts or chelate compounds.

The blending amount of the organic solvent-soluble component is preferably 0.01 ppm or more and 1% by weight or less as a metal, based on the total weight of the oligo(meth)acrylate and the polymer that is rubbery at room temperature. The amount of component 0 is 0.01ppm
If it is less than 1% by weight, the effect will be small, and even if it is added in an amount greater than 1% by weight, the effect corresponding to the amount added will not be obtained.

The curable pressure-sensitive adhesive composition of the present invention comprises (2) an oligo(meth)acrylate, (B) a polymer that is rubbery at room temperature, an organic hydroperoxide, and a cobalt compound soluble in an organic solvent; It is prepared by blending at least one compound selected from iron compounds, manganese compounds, and molybdenum compounds in any order.

The curable adhesive composition of the present invention is useful as an adhesive for adhesive materials such as adhesive tapes and prepregs.

Adhesive materials such as adhesive tapes and prepregs are essentially obtained by blending the above-mentioned four components in any order and then applying and impregnating the mixture onto a base material according to a conventional method. Coating and impregnation are performed by dissolving the adhesive composition in a desired organic solvent and then removing the organic solvent.

Examples of the base material used in the adhesive include porous materials such as nonwoven fabric, paper, cloth, porous plastic (preferably open-cell foam), and non-breathable films such as cellophane and polyethylene terephthalate films.

In the case of the former porous material, the adhesive composition having anaerobic curing properties is impregnated with non-porous material and is suitable for use as an anaerobic curing banking material, while the latter non-porous film is suitable for use as an anaerobic curing banking material. Suitable for use as adhesive tape.

The adhesive composition having anaerobic curability of the present invention may optionally contain stabilizers such as aromatic polyvalent phenols, quinones, etc., which are used in general anaerobic curable adhesives. Of course, additives such as aromatic tertiary amine accelerators can be added.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

In the examples, "parts" and "%" are expressed on a weight basis unless otherwise specified.

Example 1 [Synthesis of rubber having a methacryloyl group in the side chain] Ethyl acetate 3001 was placed in an 11 four-eye flask equipped with a stirrer, a thermometer with a gas introduction hole, a reflux condenser, and a separating funnel.
% Azobisisobutyronitrile 1g and lauryl mercaptan 0.2g were charged, and in a nitrogen stream at a temperature of 70°C, butyl acrylate 170g 1 acrylonitrile 20g, 2-
A mixed monomer of 10 g of hydroxypropyl methacrylate was fed.

After the feeding, the reflux state was maintained for 12 hours and the temperature was increased to 60't.
0.1 g of hydroquinone was added to the solution to terminate the reaction.

Next, 1 mole of 2-hydroxypropyl methacrylate and 2
．． 4-) Add 30y of a 1:1 mol reaction product of lylene diisocyanate, which has a hydroxyl value of substantially zero and has 1 mol of incyanate groups remaining, and stir at 60°C for 3 hours. did.

As a result of infrared analysis, it was confirmed that the hydroxyl groups and incyanate groups had almost completely disappeared.

Further, 300 g of ethyl acetate was added to obtain a rubber having a methacryloyl group in the side chain as a slightly yellow and viscous solution. The glass transition temperature of this rubber was about -30'C.

[Synthesis of vinyl ester resin]

In a JL five-inch flask equipped with a stirrer, a thermometer, and a reflux condenser, 500.9. Prepare 86 g of methacrylic acid, 3 g of triphenylphosphine, and 6.2 g of hydroquinone, and heat to 135°C.
When heated and stirred at ~1.400G for 3 hours, the acid value was 4.
9, heating and stirring were discontinued.

The resulting resin was yellowish brown starch syrup-like and extremely viscous oligomethacrylate-1.

214 g of ethyl acetate was added to this to make a homogeneous solution to obtain a vinyl ester resin.

[Manufacture of prepreg]

Made from polyester fibers with a thickness of about 0.3 mm, the composition consists of vinyl ester resin (solution) 40 parts cumene hydroperoxide 2 parts jetanol aniline 05 parts cobalt naphthenate (6% cobalt) 0.5 parts ethyl acetate 60 parts Apply a uniform solution of the substance, impregnate it, and heat at 40°C.
The prepreg was air-dried in an oven to obtain a prepreg with strong adhesiveness.

Cut this into a length of 12mm, 150mm x 25mm
Between two polished copper plates cleaned with X21nH triflene,
After sandwiching and crimping and leaving it in a constant temperature oven at 40℃ for 5 hours, the adhesive strength by tensile shear was measured, and it was 1.2 to 1.9 kg / cr15 before being brought into the constant temperature oven.
After standing for 5 hours, the adhesive strength was 61 to 98 kg/i, and the adhesive strength after standing for 5 hours had increased by an order of magnitude.

Incidentally, the prepreg did not lose its adhesiveness even after being left in the air at 40° C. for one month.

On the other hand, when we conducted a similar experiment using a composition in which cobalt naphthenate was omitted in the above [manufacture of prepreg], we found that the adhesive strength due to shearing was 1.
．． 2-1.9 kg/d 11-3.4 after being left for 15 hours
kg/cytX.

Example 2 [Synthesis of rubber having a methacryloyl group in the side chain] 300 g of benzene, 300 g of benzene,
Add 08 g of azobisisobutyronitrile and 0.29 g of lauryl mercaptan, and while refluxing toluene under a nitrogen atmosphere, add 08 g of azobisisobutyronitrile and 20 g of styrene.
A mixed monomer mixture of 1 maleic anhydride, 2] and 9 was heated. After the dropwise addition was completed, reflux was continued for 16 hours, the temperature was lowered to 60°C, and hydroquinone o and osg were added to terminate the reaction.

Then 2-hydroxyethyl methacrylate-1.30g1
0.69 g of dibutyltin oxide was added, and the mixture was further heated at the boiling point of toluene for 6 hours.

The acid value (in terms of solid content) of the product was 541, and it was estimated that most of the acid anhydride groups were converted into unsaturated alcohol monosuteres. After cooling to room temperature, 300 g of methyl ethyl ketone was further added to synthesize a rubber having a methacryloyl group in the side chain. The glass transition temperature of this rubber is approximately -3
It was 0°C.

[Polyester-Methacrylate Synthesis J&] Phthalic anhydride <1.
48,9, 344 g of methacrylic acid, 268 g of trimethylolpropane, 240 g of toluene, 6 L of paratoluenesulfonic acid, and 0.69 g of hydroquinone were charged, and the toluene was refluxed at the boiling point of toluene while removing the generated water azeotropically to perform esterification. I proceeded. Esterification was stopped at an acid value of 9.1, the temperature was lowered to 60°C, 300 g of 5% sodium bicarbonate water was added, and the mixture was stirred and washed. After further washing with water, toluene was distilled off while heating under reduced pressure of 300 to 350 mmH.

Toluene approx. 150. ! When i' was distilled off and no more water came out, 150 g of methyl ethyl ketone was added and dissolved uniformly to synthesize polyester-methacrylate.

After the solvent was air-dried, the resin was light yellowish brown and had a very viscous starch syrup consistency.

[Manufacture of prepregs and adhesive tapes] Rubber having methacryloyl groups in side chains (solution) 100 parts Polyester-methacrylate (solution) 50 parts tertiary-butyl hydroperoxide 3 parts dimethyl para-toluidine 0.3 parts Manganese octylate (8 parts) % manganese) 1 part methyl ethyl ketone A composition consisting of 50 parts methyl ethyl ketone was uniformly dissolved and impregnated into a nonwoven fabric similar to that used in Example 1, and air-dried in a dry oven at 50°C. The obtained prepreg exhibited strong adhesiveness.

This was cut to a width of 25++m and a length of 12 mrn, which was sandwiched between two steel plates identical to those used in Example 1 and crimped. When the adhesive strength by tensile shear was measured, the results were as follows.

Immediately after adhesion 2.9-3.6 kg/ctA After leaving for 1 night
52 to 149 kg/ff11 The improvement in adhesive strength after standing overnight was remarkable.

In addition, the above-mentioned composition was applied to cellophane with a percoater to a thickness of 0.2 mrtt, and after drying indoors,
Cut it into a length of 300 mm and 150 mm in the same way.
Glued to a 25m door x 2mm steel plate to a length of 100m,
When left overnight, it was completely cured, and the cellophane broke in the 180°J peel test.

On the other hand, the above [manufacture of prepreg and adhesive tape]
When an experiment was conducted using a composition in which manganese octylate was omitted, the adhesive strength due to shearing was 2.9 to 3.6, 9/i, immediately after adhesion.

After leaving it for one night, it was 33-79 kg/crl.

Example 3 [Synthesis of rubber having a methacryloyl group in the side chain] 300 g of benzene and 0.8 g of azobisisobutyronitrile were placed in a four-liter flask equipped with a stirrer, a thermometer with a gas introduction hole, a reflux condenser, and a dropping funnel. , 0.2 g of lauryl mercaptan was added, and 2 acrylic acid was added in a nitrogen gas stream.
-ethyl to -t/l'10011 vinyl acetate 9211
8 g of acrylic acid mixed monomers were added dropwise under refluxing benzene.

After the dropwise addition was completed, reflux was continued for 16 hours, and then the temperature was lowered to 60'C, and hydroquinone 0.1, 9. 15 g of glycidyl methacrylate and 1 (l) of triethylamine were added, and the temperature was further raised and the reaction continued for 10 hours while the contents were refluxed. When the acid value was measured, the acid value became virtually zero, and the reaction was judged to have been completed. Ta.

After distilling off a portion of triethylamine and benzene under a reduced pressure of about 400 mm H9, 300 mm of acetone was further distilled off.
g was added, and benzene was replenished to bring the total amount of solvent to 600 g.

A rubbery polymer having methacryloyl groups in the side chains was obtained. The glass transition temperature of this rubber was approximately -20°C.

[Urethane-methacrylate composition 120 g of a sill-shaped prepolymer with a hydroxyl value of 466 synthesized from 2 moles of adipic acid and 3 moles of trimethylolpropane was charged into a 1L three-meter flask equipped with a stirrer, a thermometer, and a reflux condenser, and 301 g of benzene was added. ．． After adding and dissolving 0.3.9 of dioctyltin urethane, it is an adduct of 1 mole of 2-hydroxypropyl methacrylate and 1 mole of inphorone diisocyanate, with virtually no hydroxyl groups observed and 1 mole of isocyanate groups remaining. The temperature was then raised to 60°C, and the reaction was allowed to proceed for 3 hours. As a result of infrared analysis, no absorption of incyanate groups was observed, and the reaction was judged to have been completed, and ethane-methacrylate was obtained. After being formed into a thin film and removing benzene, the urethane-methacrylate was semi-solid and sticky.

[Manufacture of adhesive prepreg]

Cut kraft paper to 300 mm x 25 ai, impregnate it with the following composition, and air dry to obtain a sticky prepreg Rubber having methacryloyl groups in the side chain (solution) 100 parts urethane-methacrylate (solution) 200 parts paramenthane hydroperoxide 3 parts molybdenum acetylacetonate (26% molybdenum) + 7) 10%
One part of the acidic butylphospade solution was cut into 12 mm pieces, which were sandwiched between 25 mm wide and 150 mm long steel plates and crimped in the same manner as in Example 1.

The adhesive strength measured by tensile shear was as follows, and the addition of molybdenum acetylacetonate was confirmed.

Example 4 Butyl acrylate 85 mol (%), acrylonitrile 1
0 moles (□□□), 5 moles of 2-ethylhexyl acrylate (glass transition temperature approximately -35°C'), i o o part of ethyl acetate so.

After dissolving 370 g of a liquid epoxy resin with an epoxy equivalent of 187 as an oligoacrylate in the solution, 144 g of acrylic acid and trimethylbenzylammonium chloride i I S hydroxyl were added. , epoxy-acrylate 1 obtained by reaction in the presence of 15I to an acid value of 41
00 parts, trimethylolpropane triac+)ray-)5
parts, further 5 parts of cumene hydroperoxide, 0.5 parts of dimethyl para-toluidine, 0.02 parts of nograbenzoquinone,
One part of iron naphthenate (12% iron) was mixed to obtain a homogeneous composition.

This was impregnated into a nonwoven fabric based on polyester fibers having a thickness of 0.2 yr, and air-dried at room temperature to produce an anaerobic curable prepreg.

A steel plate with a width of 25 mm, a length of 150 mm, and a thickness of 2 mm is ≠600 mm.
After polishing with abrasive paper and cleaning with Triclean, the prepreg was cut into 12 mm lengths, glued between the steel plates, and left at room temperature for 2 days.

The results of measuring adhesive strength by tensile shear were as follows.

Immediately after crimping 17-3.0kg/i After 2 days of storage 69-121kl? /i That is, a remarkable increase in adhesive strength was observed due to curing of the adhesive prepreg.

On the other hand, when a similar experiment was conducted using a composition in which iron naphthenate was omitted in the above method, the adhesive strength due to shearing was 1.7 to 3.0 kg/cd immediately after pressure bonding, 2.
It was 27 to 59 kg/cnl after being left for one day.

Example 5 100 g of a hydroxyl polyester with a hydroxyl value of 59.4 and an acid value of 24 obtained by esterifying a mixture of 8 moles of ethylene glycol, 2 moles of propylene glycol, 1 mole of trimethylolpropane, and 10 moles of adipic acid was added to 401 g of toluene. The mixture was dissolved, 15 g of tolylene diisocyanate was added, and the mixture was stirred at 60° C. for 3 hours.
Next, 25I of an adduct of tolylene diisocyanate and 2-hydroxypropyl methacrylate in a 1:1 molar ratio and 2(l) of polyvinyl methyl ether were added to the toluene solution of the polyester-tolylene diisocyanate, and
The reaction was continued for hours to obtain a toluene solution of a mixture of polyurethane-acrylate resin and polyvinyl methyl ether.

To this, 5 g of cumene hydroperoxide and g of dimethycin were added to obtain a pressure-sensitive adhesive composition.

The above adhesive composition was applied to a corona discharge-treated polypropylene film having a thickness of 50 μm using a bar coater, and the film was air-dried at 40 to 50° C.

This was cut to a width of 25 mvt, wrapped around a copper vibrator with a diameter of 1.1 mm, and when an attempt was made to peel it off after one day, it was found to have hardened and adhered, and the peeling occurred from the adhesive and the polypropylene film layer.

On the other hand, when a similar experiment was conducted using a composition in which cobalt octylate was omitted in the above method, peeling occurred in the adhesive layer due to insufficient strength development of the adhesive layer.

Patent applicant: Showa Kobunshi Co., Ltd. Representative Patent Attorney Sei Kikuchi

Claims (1)

[Scope of Claims] (A) an oligo(meth)acrylate having one or more acryloyl and/or methacryloyl groups in one molecule, (B) a polymer that is rubbery at room temperature, <c) an organic hydroperoxide, and 0. An adhesive composition having anaerobic curability, characterized in that it contains at least one compound selected from a cobalt compound, an iron compound, a manganese compound, and a molybdenum compound that are soluble in an organic solvent.