JPH0931435A - Highly reactive modified phenolic resin adhesive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a highly reactive modified phenolic resin adhesive which contains a resin composition comprising a specific highly reactive phenolic resin and an epoxy resin, has high adhesion resistant to water and heat, excellent corrosion prevention and adhesion to metal and high dimensional stability, and is useful in assembling of vehicles. SOLUTION: This adhesive comprises (A) a modified phenolic resin prepared by effecting polycondensation reaction between petroleum heavy oil or pitch, formaldehyde polymer and phenol in the presence of an acid catalyst and (B) an epoxy resin, when necessary, (C) a curing (accelerating) agent.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel highly reactive modified phenolic resin adhesive. More specifically, the present invention relates to an adhesive containing a novel highly reactive modified phenolic resin in which a modified phenolic resin made from petroleum heavy oils or pitches is made into a low molecular weight compound with phenols. More specifically, since the adhesive of the present invention uses the above-mentioned novel highly reactive modified phenolic resin as an essential resin component, it has excellent water-resistant adhesiveness, heat-resistant adhesiveness, and excellent corrosion resistance to metals. A modified phenolic resin that is suitable for the field of adhesives used in the assembly of vehicles such as railroad vehicles, aircraft, ships, home appliances, electronic parts, etc., because it exhibits corrosion resistance, high adhesion to metals, and excellent dimensional stability. A system adhesive is provided.

[0002]

2. Description of the Related Art Heretofore, as an adhesive exhibiting water-resistant adhesion, an epoxy resin composition containing a hydrocarbon resin, a phenol-modified coumarone-indene resin, a phenol-modified resin and the like have been known. However, when these materials are used as a paint, they are effective in improving the swelling of the coating film, but are insufficient for application in the adhesive field where higher adhesiveness is required. It was Further, heat resistance adhesion, corrosion resistance to metals and the like were also important issues for these applications.

[0003]

As a result of various studies on the above-mentioned problems, the present inventor has found that a modified phenol resin prepared from petroleum heavy oils or pitches as a raw material is modified with a phenol to give a highly reactive modification. It was found that a resin composition in which a phenol resin is mixed with an epoxy resin exhibits water-resistant and heat-resistant adhesion, excellent corrosion resistance without corrosiveness to metals, high adhesion to metals, and excellent dimensional stability. The present invention has been completed.

That is, the present invention provides: (A) a modified phenolic resin obtained by polycondensing a heavy petroleum oil or pitches, a formaldehyde polymer and a phenol in the presence of an acid catalyst, an acid catalyst Provided is a highly reactive modified phenolic resin-based adhesive containing a resin composition comprising a highly reactive modified phenolic resin, which has been reduced to a low molecular weight by reacting with a phenol in the presence of the above, and (B) an epoxy resin. The resin composition is also characterized in that it further contains a curing agent and / or a curing accelerator (C). Further, the compounding ratio of the highly reactive modified phenolic resin (A) / epoxy resin (B) is 10/90 to 90/10 (parts by weight).
It is also characterized in that

Hereinafter, the present invention will be described in detail. (1) Adhesive Resin Component Highly Reactive Modified Phenolic Resin Component (A) (i) In the present specification, petroleum heavy oils or pitches, formaldehyde polymer and phenols are used as acid catalysts. The reaction product obtained by polycondensation in the presence is referred to as "modified phenol resin", and modified phenol resin having a low molecular weight with phenols used as a resin component constituting the adhesive in the present invention is "highly reactive". They are referred to as "modified phenolic resins" (A), and they are usually used as a product free from impurities through a purification process.

The highly reactive modified phenolic resin (A) used in the present invention is basically prepared by modifying the modified phenolic resin obtained in a specific polycondensation step with a low molecular weight step of phenols under specific conditions. It is produced by a method consisting of polymerizing. The resin component constituting the adhesive of the present invention has the greatest feature in using the highly reactive modified phenolic resin (A) as an essential component.

As the resin component constituting the adhesive of the present invention, the above-mentioned highly reactive modified phenolic resin (A) and the below-mentioned epoxy resin (B) are blended, and the highly reactive modified phenolic compound is further added. Various modifier resins described below may be added in a small amount so long as the function of the resin (A) is not impaired. Of course, a curing agent and / or a curing accelerator (C) described below and, if necessary, various additives may be added to the adhesive component in advance.

(2) Production of Modified Phenolic Resin The highly reactive modified phenolic resin (A) which is one component of the adhesive according to the present invention is a modified phenolic resin obtained by a specific polycondensation step. It is produced by lowering the molecular weight in the molecular weight reduction step under the conditions. The method for producing the modified phenolic resin is preferably carried out by the method described in Japanese Patent Application No. 5-40646, and more specifically by the following method.

Modified phenol resin and method for producing the same The modified phenol resin raw material used in the present invention is obtained by polycondensing heavy petroleum heavy oils or pitches shown below, phenols and formaldehyde polymer in the presence of an acid catalyst. To be (A) Petroleum-based heavy oils or pitches It is necessary to use petroleum-based heavy oils or pitches as a raw material. The petroleum heavy oils or pitches have an aromatic hydrocarbon fraction fa value and an aromatic ring hydrogen content Ha value of
It is desirable to use the one shown in the following formula.

[0010]

[Equation 1] (The fa value can be determined by ¹³ C-NMR,
The Ha value can be determined by ¹ H-NMR. ) The aromatic hydrocarbon fraction fa value is 0.40 to 0.95,
Preferably 0.5 to 0.8, more preferably 0.55
˜0.75 and the aromatic ring hydrogen content Ha value is 20 to 80.
%, Preferably 25-60%, more preferably 25-
Desirably, it is 50%.

The petroleum-based heavy oils or pitches as raw materials are
The number of condensed rings of the aromatic hydrocarbon constituting this is not particularly limited, but it is preferably a condensed polycyclic aromatic hydrocarbon mainly having 2 to 4 rings. In the case of a condensed polycyclic aromatic hydrocarbon having five or more rings, the boiling point exceeds 450 ° C. in most cases, so that it is difficult to collect those having a narrow boiling point range and the quality is not stable. The heavy petroleum-based oils or pitches used as raw materials are
It is obtained as a distillation residual oil of crude oil, a hydrogenolysis residual oil, a catalytic cracking residual oil, a thermal decomposition residual oil of naphtha or LPG and a vacuum distillate of these residual oils, an extract by solvent extraction or a heat-treated product. From these, the fa value and H
It is preferable to select and use a suitable a value.

(B) Formaldehyde Polymer As the raw material formaldehyde polymer, there can be mentioned linear polymer such as paraformaldehyde, polyoxymethylene (particularly, oligomer) and cyclic polymer such as trioxane. The mixing ratio of heavy petroleum oils or pitches (a) and formaldehyde polymer (b) is
The number of moles of the formaldehyde polymer in terms of formaldehyde is 1 to 15, preferably 2 to 12, and more preferably 3 to 11 per 1 mole of the average number of moles calculated from the average molecular weight of heavy petroleum oils or pitches. I need to be there.

If the mixing ratio is less than 1, an adhesive having sufficient physical properties may not be obtained, which is not preferable. On the other hand, when the mixing ratio is more than 15, the performance of the obtained adhesive and the yield of the modified phenol resin hardly change, so it is considered useless to use more formaldehyde polymer. Further, the excess formaldehyde polymer may hinder the molecular weight reduction of the modified phenol resin in the molecular weight reduction step described later.

(C) Phenols Examples of phenols as raw materials include phenol, cresol, xylenol, resorcin, catechol, hydroquinone, bisphenol A, bisphenol F and α-.
One or more phenolic compounds selected from the group of naphthol and β-naphthol can be mentioned. The amount of phenols added is 0.3 to 5, preferably 0.5 to 3, as the number of moles of phenols per 1 mole of the average number of moles calculated from the average molecular weight of heavy petroleum oils or pitches. I need to be there.

If the amount added is less than 0.3, the reactivity of heavy petroleum oils or pitches with formaldehyde will be inferior to that of phenols with formaldehyde, so a sufficient crosslinking density will be obtained. Therefore, an adhesive having sufficient physical properties cannot be obtained. On the other hand, when the addition amount of phenols exceeds 5, the modifying effect due to the modification of the phenol resin tends to decrease.

Phenols are preferably added sequentially by a method such as dropping. The rate of addition is from 0.05 to 5% by weight, preferably 0.1 to 2% by weight, based on the total weight of the reaction mixture. The timing for starting the addition of the phenols is not particularly limited, but the timing for starting the addition may be the time at which the reaction between the petroleum heavy oil or pitches and formaldehyde has not substantially progressed. In practice, from the state in which the reaction rate of formaldehyde estimated from the amount of remaining free formaldehyde is substantially 0,
It is desirable to start the sequential addition of phenols at the time of 0% or less, preferably 50% or less.

(D) Acid catalyst As the acid catalyst, a Bronsted acid or a Lewis acid can be used, but a Bronsted acid is preferably used. As the Bronsted acid, toluenesulfonic acid,
Xylene sulfonic acid, hydrochloric acid, sulfuric acid, formic acid and the like can be used, but p-toluene sulfonic acid and hydrochloric acid are particularly excellent.
The amount of the acid catalyst used is 0.1 to 30% by weight, preferably 1 to 30% by weight based on the total amount of the petroleum heavy oil or pitches, the formaldehyde polymer and the phenols, which are raw materials for production.
It is 20% by weight.

(V) Reaction conditions In order to produce a modified phenolic resin in the polycondensation step using the above raw materials and catalysts, for example, petroleum heavy oils or pitches and formaldehyde polymer should be in the above proportions. It is preferable that the mixture is heated and stirred in the presence of an acid catalyst, and phenols are successively added to the mixture until the above ratio is reached to polycondense these raw materials. At that time, the reaction temperature is 50 to 160 ° C, preferably 60 to 120 ° C. The reaction temperature is determined in consideration of the raw material composition, the reaction time, the properties of the resin produced, and the like. Reaction time is 0.5-10
Hours, preferably 1 to 5 hours. The reaction time is determined in consideration of the raw material composition, the reaction temperature, the addition rate of phenols, the properties of the resin to be formed, and the like.

When the reaction is carried out batchwise, it can be carried out in one step, and preferably carried out in one step. In addition, when the continuous method is used, it is not necessary to use a device that is difficult to control, such as continuously mixing two or more kinds of reaction products, which are used in the conventional modified phenol resin, in a fixed amount, and the intermediate portion is used. A reaction vessel of a complete mixing type may be placed, and the phenols to be added may be fed into the reaction vessel in fixed amounts.
Such a device is relatively inexpensive and has good operability.

In the present invention, such a polycondensation reaction can be carried out without a solvent, but in that case, it is necessary to pay attention to the uniformity of the reaction. A suitable solvent may be used to reduce the viscosity of the reaction system so that a uniform reaction may occur.
The solvent is not particularly limited, but is, for example, aromatic hydrocarbon such as benzene, toluene, xylene;
Halogenated aromatic hydrocarbons such as chlorobenzene; Nitrated aromatic hydrocarbons such as nitrobenzene; Nitrated aliphatic hydrocarbons such as nitroethane and nitropropane; Halogenated fats such as perkrene, trichlene and carbon tetrachloride Examples thereof include group hydrocarbons.

Step of Purifying Modified Phenolic Resin The highly reactive modified phenolic resin according to the present invention is prepared by lowering the molecular weight of the modified phenolic resin obtained by the polycondensation reaction in the lowering molecular weight step according to the method of the present invention. it can. However, in the modified phenol resin obtained by the polycondensation step, in addition to the target modified phenol resin, an acid catalyst, unreacted components, reaction solvent, and the like may remain, and these are low molecular weight reaction. It affects the reaction conditions and the amount of raw materials, catalysts, etc. involved in the reaction. For example, when the modified phenol resin used in the step of lowering the molecular weight contains a large amount of a formaldehyde polymer which is a crosslinking agent as an unreacted component, a modified phenol resin,
The polycondensation reaction of the formaldehyde polymer and the phenols may precede the inhibition of lowering the molecular weight.

Therefore, in order to suitably set the reaction conditions in the low molecular weight reduction step so that the modified phenolic resin can efficiently reduce the low molecular weight by the reaction between the modified phenol resin and the phenols, it is necessary to use in the low molecular weight reduction step. It is desirable that the modified phenolic resin obtained does not contain an acid catalyst or formaldehyde polymer in an amount that inhibits the molecular weight reduction reaction. That is, after the polycondensation step, it is preferable to perform the following purification steps on the modified phenol resin in any order or, if necessary, simultaneously in order to control the reaction to reduce the molecular weight of the phenols.

(I) A purification step of treating / precipitating with a specific solvent to remove solvent-soluble components including unreacted components, and (i
i) A purification step of dissolving in a specific solvent to remove the catalyst residue and the cross-linking agent can be mentioned. That is, in the refining step (i) for removing such unreacted components, the reactivity contained in the raw material petroleum heavy oils or pitches is low, and the unreacted or insufficiently reacted. No ingredients,
And a step of removing the solvent used in the reaction.

Specifically, the reaction product obtained in the polycondensation step is treated with an aliphatic hydrocarbon having 10 or less carbon atoms or an alicyclic ring having 10 or less carbon atoms at any time after the completion of the heating reaction. At least one selected from the group consisting of formula hydrocarbons
Pour into a specific solvent containing various compounds to precipitate the resin main component, and remove components soluble in the solvent, that is, components that remain unreacted and low reaction and reaction solvent during polycondensation reaction. Done by. Specific examples of such a hydrocarbon solvent include aliphatic or alicyclic hydrocarbons such as pentane, hexane, heptane, and cyclohexane, and n-hexane is particularly preferable.

In the purification step (ii) for removing the catalyst residue such as acid and the cross-linking agent, in order to remove the catalyst residue such as acid and the cross-linking agent remaining in the reaction mixture obtained by the polycondensation step, an acid catalyst is used. The solubility of the cross-linking agent is 0.1 or less, preferably 0.07 or less, and it is hardly soluble. However, it is performed by performing an extraction treatment using an extraction solvent that dissolves most of the modified phenolic resin. The extraction solvent is hardly soluble when the solubility of the acid catalyst and the cross-linking agent is 0.1 or less, but is not particularly limited as long as it is a solvent capable of dissolving most of the modified phenolic resin. For example, benzene, toluene, xylene, and other aromatic compounds. Group hydrocarbons are preferred, and toluene is more preferred.

In the present invention, the refining step (ii) is not limited to the conditions such as its temperature, but may be carried out under the conditions that the above-mentioned characteristics of the solvent are sufficiently exhibited. In the purification step (ii), the reaction product may be added to the solvent, or conversely, the solvent may be added to the reaction product. Of course, the catalyst residue such as acid and the cross-linking agent can be substantially removed only by the above extraction treatment. However, if desired, the modified phenolic resin after the purification step (ii) by the extraction treatment is usually followed by the following steps. Neutralization treatment and /
Alternatively, washing with water may be performed to further remove catalyst residues such as acids in the resin.

Particularly, after the extraction treatment, the neutralization treatment is preferably performed when a slight amount of acid catalyst or the like may remain in the extraction solution. Examples of the neutralization treatment include addition of a basic substance to the modified phenol resin after the purification step (ii). Examples of the basic substance include hydroxides of alkali metals such as sodium hydroxide, potassium hydroxide, calcium hydroxide and magnesium hydroxide, alkaline earth metal hydroxides; ammonia, diethylenetriamine, triethylenetetramine, aniline, phenylenediamine, etc. Can be mentioned.

In the purification step of the present invention, such purification steps (i) and (ii) can be performed in any order. However, the modified phenolic resin after the purification step (ii) is usually in the form of a varnish dissolved in a solvent, and this varnished modified phenolic resin is used as it is or after adjusting the resin concentration by concentrating or adding an organic solvent. It can be used as a raw material in the step of lowering the molecular weight. In addition, the varnish-like modified phenol resin is collected as a powdery modified phenol resin which is put into a solvent in which the modified phenol resin is insoluble, for example, n-hexane and is re-precipitated, and is a raw material for the subsequent low molecular weight conversion step. You may use as.

Production of highly reactive modified phenolic resin The novel highly reactive modified phenolic resin of the present invention can be obtained by the method described in Japanese Patent Application No. 6-23617, for example, such modified phenolic resin, that is, a polycondensation step. The reaction product thus obtained can be produced as it is or after purification, by reacting it with a phenol in the absence of a formaldehyde polymer and other cross-linking agent and in the presence of an acid catalyst to lower the molecular weight.

In such a low molecular weight reaction, the modified phenolic resin is cut and dissociated by breaking and dissociating the acetal bond and / or methylene ether bond present in the molecule, and the phenols are added to the dissociated terminal portion. It is considered that since these compounds bind to each other to increase the phenol content of the modified phenolic resin, a highly reactive modified phenolic resin having a low resin melt viscosity and excellent reactivity with an epoxy resin can be obtained.

Therefore, the amount of the raw material and the acid catalyst used in the step of lowering the molecular weight, the type and combination thereof, the reaction conditions such as the reaction temperature, etc., are the lower molecular weight of the modified phenol resin and the reaction activity with the epoxy resin. There is no particular limitation as long as it is a range that can improve the above. However, it is important to appropriately select the reaction conditions such as the type and amount of the acid catalyst used in the molecular weight reduction step, the reaction temperature, and / or the type and amount of the reaction solvent. The phenols and acid catalysts used in the molecular weight reduction step may include the compounds exemplified in the polycondensation step.

In the step of lowering the molecular weight of the present invention, the phenols react sufficiently if they are 10% by weight or more based on the weight of the modified phenol resin, but if too much phenol is used, a large amount of unreacted phenols is used. Remains, resulting in an increase in the cost required for the post-treatment, so the content is preferably 10 to 300% by weight. Further, the addition of phenols does not necessarily have to be sequential addition, and the entire amount may be introduced into the reaction system at the start of the reaction.

The amount of the acid catalyst used is 0.1% by weight or more, preferably 0.1 to 1% by weight based on the weight of the modified phenolic resin.
It is desirable to use 5% by weight, more preferably 0.1 to 10% by weight, and even more preferably 0.2 to 10% by weight. In the step of lowering the molecular weight, the reaction solvent may or may not be used. The reaction solvent used is not particularly limited as long as it does not inhibit the above-mentioned molecular weight reduction reaction,
Examples thereof include solvents used in the polycondensation reaction, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone: alcohols such as methyl alcohol, ethyl alcohol and n-butyl alcohol: ethers such as tetrahydrofuran.

Such a solvent is preferably used in an amount of 0 to 300% by weight based on the modified phenolic resin. The reaction temperature is not particularly limited, but is usually 50 to 120 ° C, preferably 80 to 120 ° C. The reaction time is not particularly limited, and is, for example, 15 minutes to 3.0 hours, preferably 30 minutes to 2.0 hours.

Post-Treatment of Highly Reactive Modified Phenolic Resin Since the highly reactive modified phenolic resin may leave unreacted components, catalyst residues such as acids, etc., it may be purified by a method such as washing with water, It is necessary to remove catalyst residues such as reaction components and acids. Preferably, the reaction product is diluted using a mixed solvent of toluene and alcohols such as methanol and ethanol or a mixed solvent of toluene and ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, and then distilled water and / or Alternatively, washing treatment is performed with a mixed liquid of distilled water and isopropyl alcohol to remove unreacted components such as phenols and catalyst residues such as acids.

Further, the highly reactive modified phenolic resin is
After removing unreacted components and catalyst residues such as acids as described above, the extraction solvent is desolvated, or a solvent in which the highly reactive modified phenolic resin is insoluble, that is, an aliphatic or alicyclic group having 10 or less carbon atoms. The resin is preferably precipitated by treatment with a formula hydrocarbon or a mixed solvent thereof. Examples of such a hydrocarbon solvent include the solvents described in the step of purifying the modified phenolic resin, and n-hexane is particularly preferable.

Features of highly reactive modified phenolic resin (A) (a) The highly reactive modified phenolic resin (A) itself has the following features as compared with the modified phenolic resin. -The number average molecular weight decreases, and the number average molecular weight is 300-
It has a molecular weight of 800, improves reactivity with epoxy resin, and lowers resin melt viscosity. Therefore, when the highly reactive modified phenolic resin (A) is used as a mixture with the epoxy resin (B), it has excellent heat-resistant adhesiveness and adhesiveness with metal, and does not substantially contain acid, so that it corrodes the metal. And has excellent water-resistant adhesion.

Epoxy Resin Component (B) When the highly reactive modified phenolic resin (A) of the present invention is used as an essential resin component of an adhesive, it is necessary to blend an epoxy resin. The adhesive obtained by this further improves the dimensional stability of the adhesive layer after adhesion,
It is possible to improve the adhesiveness with metal and the like. In this case, it is a more preferable embodiment to incorporate a curing agent and / or a curing accelerator (C). As epoxy resin,
For example, glycidyl ether type, glycidyl ester type,
Examples thereof include glycidyl amine type, mixed type and alicyclic type epoxy resins.

More specifically, as the glycidyl ether type (phenol type), bisphenol A type epoxy resin, biphenyl type epoxy resin, bisphenol F are used.
Type epoxy resin, tetrabromobisphenol A type epoxy resin, tetraphenylolethane type epoxy resin,
Phenol novolac type epoxy resin, o-cresol novolac type epoxy resin and the like; glycidyl ether type (alcohol type) such as polypropylene glycol type epoxy resin and water-added bisphenol A type epoxy resin; glycidyl ester type such as hexahydroanhydrous Phthalic acid type epoxy resin, dimer acid type epoxy resin, etc .;

Examples of the glycidylamine type include diaminodiphenylmethane type epoxy resin, isocyanuric acid type epoxy resin, hydantoic acid type epoxy resin, and the like; mixed types include p-aminophenol type epoxy resin, p-
Examples thereof include oxybenzoic acid type epoxy resin. Of the above epoxy resins, bisphenol A type epoxy resin, glycidyl amine type epoxy resin, phenol novolac type epoxy resin, and biphenyl type epoxy resin are preferable. A combination of two or more of the above epoxy resins can also be used.

The mixing ratio of the highly reactive modified phenolic resin (A) and the epoxy resin (B) is not particularly limited, but the highly reactive modified phenolic resin (A) and the epoxy resin (B) are included.
The total of 100 parts by weight is 10/90 to 90/10
(Parts by weight) is preferable, and more preferably 20
/ 80 to 80/20 (parts by weight). Here, if the weight ratio of the highly reactive modified phenolic resin (A) is less than 10 parts by weight, the effect of improving the heat resistance and weather resistance of the obtained adhesive layer is not sufficient, and if it exceeds 90 parts by weight, the epoxy resin is added. The compounding effect is halved, and the dimensional stability of the adhesive layer, the adhesiveness with metal, etc. become poor.

Addition of Curing Agent and / or Curing Accelerator (C) The highly reactive modified phenolic resin (A) used as an essential component of the adhesive, together with the epoxy resin (B), the curing agent and / or the curing accelerator (C). It is desirable to add. Various things can be used as a hardening agent and / or a hardening accelerator (C). Examples of the curing agent include cyclic amines, aliphatic amines, polyamides, aromatic polyamines and acid anhydrides.

Specifically, for example, as cyclic amines, hexamethylenetetramine and the like; as aliphatic amines, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, diethylaminopropylamine, N-aminoethylpiperazine, isophoronediamine. , Bis (4-amino-3-methylcyclohexyl) methane, menthanediamine, etc .; as polyamides, vegetable oil fatty acid (dimer or trimer acid), aliphatic polyamine condensate, etc .;

As aromatic polyamines, m-phenylenediamine, 4,4'-diaminodiphenylmethane,
4,4′-diaminodiphenyl sulfone, m-xylylenediamine, etc .; as the acid anhydrides, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride,
Trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, chlorendic anhydride, dodecynyl succinic anhydride, methyltetrahydrophthalic anhydride,
Methyl endomethylene tetrahydrophthalic anhydride etc. can be mentioned.

The curing accelerator is not particularly limited as long as it accelerates the curing reaction, and for example, diazabicycloalkene such as 1,8-diazabicyclo (5,4,0) undecene-7 and its derivatives; triethylenediamine. , Benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris (dimethylaminomethyl)
Tertiary amines such as phenol; imidazoles such as 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-heptadecylimidazole; tributylphosphine, methyl Organic phosphines such as diphenylphosphine and triphenylphosphine; Tetra-substituted phosphonium / tetra-substituted borate such as tetraphenylphosphonium / tetraphenylborate; 2-
Tetraphenylboron salts such as ethyl-4-methylimidazole tetraphenylborate, N-methylmorpholine tetraphenylborate, Lewis acids such as boron trifluoride-amine complex and tris (dimethylaminomethyl) phenol, benzyldimethyl Examples thereof include amines, dicyandiamide, Lewis bases such as adipic acid dihydrazide, and polymercaptans and polysulfides. Further, these curing agents and curing accelerators may be used alone or in combination of two or more.

Composition of Adhesive (i) Addition of Various Modifier Resins and Additives In the adhesive of the present invention, other modifier resins may be added as required to function as the highly reactive modified phenolic resin (A). It may be added in a small amount within the range that does not impair. Examples of these modifier resins include thermosetting acrylic resins, phenol resins, melamine resins, blocked isocyanates, and the like. Further, various additives can be added if necessary. Examples of these additives include various chelating agents, inorganic fillers (talc, clay, calcium carbonate, silicate), antioxidants, ultraviolet absorbers, silane coupling agents, and the like.

(Ii) Organic solvent (diluent) In the adhesive of the present invention, an organic solvent (diluent) for dissolving the resin component constituting the adhesive and / or diluting the obtained adhesive liquid. Is a necessary ingredient. Therefore, the organic solvent (diluent) used in the present invention is not particularly limited as long as it is a good solvent that can dissolve and / or dilute the resin component of the adhesive used as a soluble component as much as possible. It may be a mixed solvent. In this case, the content of the resin component in the adhesive is usually 50 per 100 parts by weight of the adhesive.
To 90 parts by weight, preferably 60 to 80 parts by weight.

Examples of good solvents for the highly reactive modified phenolic resin (A) include aromatic hydrocarbons such as benzene, toluene and xylene; amides such as dimethylformamide; halogenated aromatic hydrocarbons such as chlorobenzene. Ethers such as tetrahydrofuran and dioxane; alcohols such as methanol and ethanol; glycols such as ethyl cellosolve; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone;
Esters such as ethyl acetate; chloroform, methylene chloride, perclen or a mixture thereof can be mentioned. Among them, it is preferable to use at least one organic solvent selected from aromatic hydrocarbons, amides, ketones, alcohols and halogenated aromatic hydrocarbons.

On the other hand, the good solvent for the epoxy resin (B) is appropriately selected and used from organic solvents which have been widely used in the past. For example, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; methanol, Preference is given to alcohols such as ethanol; aromatic hydrocarbons such as toluene and xylene, or a mixture thereof.

(Iii) Preparation of Adhesive To manufacture the adhesive of the present invention, basically, a highly reactive modified phenolic resin (A) and an epoxy resin (B) and, if necessary, a curing agent and / or A curing accelerator (C) and the above-mentioned various modifier resins are dissolved in an organic solvent to prepare an adhesive solution. An appropriate additive is added to and mixed with this to prepare an adhesive. Regarding the operation and conditions for dissolving the resin components such as the highly reactive modified phenolic resin (A) and the epoxy resin (B) and the curing agent and / or the curing accelerator (C) in the organic solvent, the organic solvent to be used It may be appropriately selected depending on the type of the adhesive and the type of the adhesive resin component.

For example, 10 to 70% at room temperature or under heating
The highly reactive modified phenolic resin (A) is added to the organic solvent in such a proportion that it becomes a solution, and after stirring for about 10 minutes to 1 hour, insoluble components are removed by filtration or the like, if necessary. The solution is appropriately concentrated to produce a highly reactive modified phenolic resin solution. Separately, an epoxy resin solvent solution is manufactured by the same operation. After that, both are mixed at a predetermined ratio to obtain an adhesive. This mixing method is operationally preferable.

Further, after adding the highly reactive modified phenolic resin (A) to the organic solvent, the epoxy resin (B) may be subsequently added to obtain an adhesive solution. Or conversely, after adding the above epoxy resin (B) to the organic solvent,
Highly reactive modified phenolic resin (A) may be added. Further, the highly reactive modified phenolic resin (A) and the epoxy resin (B) are simultaneously added to the organic solvent, or the highly reactive modified phenolic resin (A) and the epoxy resin (B) are mixed in advance and then the organic solvent is added. May be added to.

[0053]

[Function] Since the highly reactive modified phenolic resin (A) as an essential component of the adhesive has a condensed condensed polycyclic aromatic nucleus in its skeleton, it has a water content higher than that of a normal phenolic resin. Since it hardly penetrates into the adhesive interface, the water-resistant adhesive property becomes good. Since it has a heat-resistant condensed polycyclic aromatic nucleus in the skeleton, it has excellent heat resistance, does not deteriorate even in a high-temperature atmosphere for a long time, and has excellent heat-resistant adhesiveness. Since the resin does not contain a corrosive acid, it has a function of not corrosive to metals.

[0054]

The present invention is illustrated by the following examples, which do not limit the scope of the invention. In the following examples, all parts are by weight unless otherwise specified, and the properties of the feedstock used as a starting material are shown in Table 1.
Shown in These feedstocks are obtained by distilling the bottom oil obtained by fluid catalytic cracking (FCC) of vacuum gas oil.

[0055]

[Table 1]

(Example 1) 334 g of raw material oil shown in Table 1,
Paraformaldehyde (370 g), p-toluenesulfonic acid monohydrate (137 g) and p-xylene (678.5 g) were charged into a glass reactor and heated to 95 ° C. with stirring. After holding at 95 ° C. for 1 hour, 209 g of phenol was appropriately applied at an appropriate rate of 1.3 g / min, and after completion of the appropriate amount of phenol, the mixture was further stirred for 15 minutes. Then the reaction mixture is n
-Pour into 3300 g of hexane to precipitate a reaction product, and filter to remove unreacted components and reaction solvent. 16
After washing the precipitate with 00 g of n-hexane, vacuum drying,
A crude modified phenolic resin powder containing an acid was obtained.

This resin powder was dissolved in 10 times the weight of toluene, and the insoluble material containing p-toluenesulfonic acid monohydrate as the main component was filtered. The obtained resin toluene solution was concentrated to a resin concentration of 50% by weight to obtain an acid-free modified phenol resin toluene solution. After a slight amount of triethylenetetramine was added to the solution to neutralize it, this toluene solution was poured into 3.3 times by weight of n-hexane to precipitate a resin, which was then filtered. Then, vacuum drying was performed to obtain 580 g of acid-free modified phenol resin powder. 100 g of the obtained acid-free modified phenolic resin powder, 200 g of phenol, and 5 g of p-toluenesulfonic acid were charged into a 500 ml glass reaction vessel and stirred at a speed of 250 to 350 rpm to obtain 9
The temperature was raised to 5 ° C and the reaction was carried out at 95 ° C for 90 minutes to obtain a reaction product.

The above reaction product was mixed with a toluene / methylisobutylketone mixed solution in an amount twice that of the product (mixing ratio 4/1).
To prepare a resin solution. The resin solution obtained was washed with distilled water / isopropanol mixed solution to extract and remove the acid and unreacted components contained in the reaction product, and then the toluene / methyl isobutyl ketone mixed solution was removed with an evaporator, Further, it was vacuum dried under heating to obtain 190 g of a highly reactive modified phenol resin powder containing substantially no acid. Methyl ethyl ketone was added to this resin powder so that the resin concentration was 60% by weight, to obtain 317 g of a highly reactive modified phenol resin solution.

On the other hand, 285 g of a bifunctional epoxy resin [Epicoat 828, manufactured by Yuka Shell Epoxy Co., Ltd.] and 2.85 g of 2-ethyl-4-methylimidazole were added to 71 g of methyl ethyl ketone to obtain an epoxy resin solution. . The above-mentioned highly reactive modified phenolic resin solution was mixed with the obtained epoxy resin solution to obtain an adhesive resin solution having a ratio of 4 parts by weight of highly reactive modified phenolic resin and 6 parts by weight of epoxy resin. Test pieces were prepared from this adhesive solution as follows, and the following tests were conducted. The results are shown in Table 2.
Summarized in

(A) Method of preparing test piece After applying an adhesive agent to each of two aluminum plates (25 × 125 × 0.5 mm) using a bar coater, the two sheets were pasted together, and 180 ° C. for 3 hours A heat-cured test piece was prepared. (B) Adhesion test In accordance with the T-type peeling test method of JIS K-6854, "peeling adhesive strength of adhesive" is measured, and further, JIS K-685.
"Tensile shear adhesive strength" of 0 was measured (here, a pulling speed of 50 mm / min and an ambient temperature of 25 ° C).

(C) Water resistance test After treatment according to JIS K-6857 "Adhesive water resistance test method", an adhesion test was carried out by the test method (B). (D) Heat resistance test The test piece was kept in an atmosphere of 150 ° C., and an adhesion test was conducted by the test method of (b). Further, it was stored in a gear oven under the condition of 150 ° C., and an adhesion test was conducted by the test method (b).

Example 2 The same operation as in Example 1 was carried out to obtain a modified phenol resin powder containing substantially no acid.
500 g of 100 g of the obtained resin powder, 66 g of phenol, 40 g of toluene and 1.5 g of p-toluenesulfonic acid are added.
Charge to a ml glass reaction vessel, 250-350 rpm
The temperature was raised to 95 ° C with stirring at the speed of
The reaction was carried out by holding for a minute to obtain a reaction product containing a highly reactive modified phenolic resin. The reaction product is
Double volume of toluene / methyl alcohol mixture (mixing ratio 4 /
It melt | dissolved in 1) and prepared the resin solution.

The obtained resin solution is washed with distilled water / isopropanol mixed solution to extract and remove the acid and unreacted components contained in the reaction product, and then the toluene / methyl alcohol mixed solution is removed with an evaporator. Then, it was vacuum dried under heating to obtain 140 g of a highly reactive modified phenol resin powder containing substantially no acid. Methyl ethyl ketone was added to this resin powder so that the resin concentration was 60% by weight, to obtain 233 g of a highly reactive modified phenol resin solution.

On the other hand, 285 g of the bifunctional epoxy resin used in Example 1 was added to 71 g of methyl ethyl ketone and 2-ethyl-
An epoxy resin solution in which 2.85 g of 4-methylimidazole was added and dissolved was obtained. The epoxy resin solution thus obtained was mixed with the highly reactive modified phenolic resin solution, and an adhesive solution was prepared in the same manner as in Example 1. A test piece was prepared from this adhesive solution in the same manner as in Example 1 and tested. The results are summarized in Table 2.

[0065]

[Table 2]

[0066]

As described above, according to the novel highly reactive modified phenolic resin adhesive of the present invention, high water-resistant and heat-resistant adhesive properties, excellent anticorrosion property without corrosiveness against metals, and the like Provides high adhesion and excellent dimensional stability.

Claims (3)

[Claims] 1. A modified phenolic resin obtained by polycondensing (A) a petroleum heavy oil or pitches, a formaldehyde polymer and a phenol in the presence of an acid catalyst in the presence of an acid catalyst. A highly reactive modified phenolic resin-based adhesive comprising a resin composition comprising a highly reactive modified phenolic resin which has been reduced to a low molecular weight by reacting with phenols and (B) an epoxy resin. 2. The highly reactive modified phenolic resin adhesive according to claim 1, wherein the resin composition further contains a curing agent and / or a curing accelerator (C). 3. A highly reactive modified phenolic resin (A) / epoxy resin (B) compounding ratio of 10/90 to 90/10.
The highly reactive modified phenolic resin adhesive according to claim 1, which is (parts by weight).