JPH04189812A - Method for preparing novolak type aromatic hydrocarbon-formaldehyde resin, epoxy resin curing agent and epoxy resin composition - Google Patents

Abstract

PURPOSE:To prepare the subject resin useful as a curing agent for epoxy resins and giving cured products having excellent water resistance, by reacting a resol type phenolic resin with a condensed polycyclic aromatic hydrocarbon containing phenolic hydroxyl groups. CONSTITUTION:(A) A resol type phenolic resin (preferably a resin produced from a phenol compound and an aldehyde in the presence of a basic catalyst) is reacted with (B) a condensed polycyclic aromatic hydrocarbon having a phenolic hydroxyl group) (e.g. alpha-naphthol) preferably so that the equivalent of the methylol groups in the component A is the same as the equivalent of hydrogen atoms capable of reacting with the formaldehyde in the component B or so that the equivalent of the hydrogen atoms in the component B is excessive, thus providing the objective resin.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for producing a novolak aromatic hydrohydrogen-formaldehyde resin, an epoxy resin curing agent, and an epoxy resin composition.

<Prior art> A novolac type phenol resin made by reacting a resol type phenol resin with phenols is disclosed in Japanese Patent Application Laid-Open No. 63-254.
It is known from JP-A No. 123, JP-A-62-212410, JP-A-63-77915, and JP-A-56-92908.

(Problem to be solved by the invention) However, when the novola and 7-type phenolic resins described in the above publication are used as curing agents for epoxy resins, for example, the cured products have poor water resistance. There were drawbacks.

<Means for Solving the Problems> In view of the above-mentioned circumstances, the present inventors conducted extensive studies and found that a novolac-type phenol obtained by using a condensed polycyclic aromatic hydrocarbon having a phenolic hydroxyl group in place of phenols. The inventors have discovered that a resin can solve the above problems and have completed the present invention.

That is, the present invention provides a resol-type phenolic resin (A) and a condensed polycyclic aromatic hydrocarbon having a phenolic hydroxyl group (B).
) A method for producing a novolac-type aromatic hydrocarbon-formaldehyde resin, which is characterized by reacting a resol-type phenolic resin (A) with a condensed polycyclic aromatic hydrocarbon having a phenolic hydroxyl group (B). Nohora that was obtained.

In an epoxy resin curing agent made of a resol type aromatic hydrocarbon-formaltehyde resin and an epoxy resin composition consisting of an epoxy resin and a curing agent, the curing agent is a resol type phenolic resin (A) and a condensed polyester having a phenolic hydroxyl group. The present invention provides an epoxy resin composition characterized by using a novolac type aromatic hydrocarbon-formaldehyde resin obtained by reacting a cyclic aromatic hydrocarbon (B) with a cyclic aromatic hydrocarbon (B).

The novolac type aromatic hydrocarbon-formaldehyde resin of the present invention can be produced by reacting the resol type phenol resin (A) with a condensed polycyclic aromatic hydrocarbon having a phenolic hydroxyl group. As the resol type phenolic resin (A) used in this case, any known and commonly used resin can be used. For convenience, the method for producing the 7-horank aromatic hydrocarbon-formaldehyde resin of the present invention is as follows:
It is divided into processes. For example, resol type phenolic resin (
If the manufacturing process of A) is the first step, this first step is
This is a process in which phenols and formaldehyde are reacted using a resolization catalyst. After this process, substantially all of the nuclear hydrogens in the phenols that are reactive with formaldehyde are combined with formaldehyde, forming methylene groups, Forms a methylol group and a dimethylene ether group. In addition, the nuclear hydrogen which is reactive with formaldehyde of the above-mentioned phenols is a hydrogen atom located at the ortho position and the para position with respect to the phenolic hydroxyl group of the phenol.

The phenols used in the first step of the present invention include:
For example, phenol, cresol, xylenol, resorcinol, tert-butylphenol, 5ec-
Butylphenol, octylphenol, nonylphenol, bisphenol A1 Bisphenol F1 Bromophenol, fluorophenol, chlorophenol, and other ortho, meta, and rose isomers are listed, and contain at least two nuclear hydrogen atoms that can react with formaldehyde.
Those having more than 100% are used as essential components. Of course, if necessary, a phenol having less than two nuclear hydrogen atoms capable of reacting with at least formaldehyde may be used in combination.

Formaldehyde used in the present invention includes an aqueous solution such as forma-1-one, a solid such as paraform and trioxane,
It can be used either in the form of a gas or in the form of a gas. However, a water-soluble form such as formalin is preferred because it is industrially easiest to handle.

In the first step, formaldehyde is usually phenol 1
It is used in an amount exceeding 1 mole per mole.

The amount of formaldehyde used is preferably 1.0 to 3.5 mol per 1 mol of phenol.

For example, when using only phenols having two nuclear hydrogen atoms capable of reacting with formaldehyde, the amount is preferably 1.6 to 2.6 mol per mol of phenol.

As the resolization catalyst used in the first step of the present invention, any known and commonly used catalyst can be used, such as alkali metal hydroxides, alkaline earth metal hydroxides or oxides, and organic acids thereof. Salt is an example. Specific examples include lithium hydroxide, sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, sodium carbonate, magnesium oxide, zinc acetate, and the like.

These catalysts may be used alone or in combination of two or more.

The amount of the catalyst used is not particularly limited, but is usually in the range of 0.5 to 20 parts by weight per 100 parts by weight of the phenol.

The reaction in the first step of the present invention is carried out at a temperature of 30 to 150°C, preferably 30 to 80°C.

The reaction time may be any reaction time necessary for substantially all of the nuclear hydrogen to be added to the reaction of the phenols to react, and is usually in the range of 30 minutes to 24 hours.

When resol type phenolic resin is industrially produced, a method is adopted in which a part of the reaction raw material is added to the reaction vessel sequentially or in stages in order to avoid rapid temperature rise due to reaction heat. This method can also be adopted in the first step. In this case, a method may be used in which one or both of phenols and formaldehyde are continuously added to the reaction vessel.

In the first step of the present invention, benzene,
Toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, ethyl cellosolve, butyl cellosolve,
An inert organic solvent capable of dissolving the reaction product, such as ethyl carpitol, can also be added at the beginning, during or after the reaction.

The resol type phenolic resin (A
) can be neutralized with acid to terminate the reaction, if necessary. Examples of acids that can be used in this case include mineral acids such as hydrochloric acid, sulfuric acid, and phosphoric acid, and organic acids such as oxalic acid, formic acid, p-toluenesulfonic acid, and phenolsulfonic acid.

After the first step, unreacted formaldehyde and phenols can be removed from the reaction product by washing with water or distilling. The above-mentioned water washing separation is also important in that, for example, in the case where the resolization catalyst or the neutralized salt thereof can be removed. This water washing and separation removes components derived from the catalyst when a catalyst is used in the first step, so that the noholak-forming reaction in the second step, which will be described later, proceeds smoothly.

The novolac type aromatic hydrocarbon-formaldehyde resin according to the present invention is produced by adding, for example, a fused polycyclic aromatic hydrocarbon (B) having a phenolic hydroxyl group to the resol type phenol resin (A) obtained in the above first step. It can be easily produced by reaction. Hereinafter, this step will be referred to as the second step.

In the second step, resol type phenolic resin (A
) and the condensed polycyclic aromatic hydrocarbon (B) having a phenolic hydroxyl group is not particularly limited, but is usually based on the equivalent of the methylol group of the resol type phenolic resin (A) and the aromatic hydrocarbon (B). The equivalent ratio of nuclear hydrogen that can react with formaldehyde is the same or the aromatic hydrocarbon (B)
The ratio is such that the equivalent amount of nuclear hydrogen is in excess.

In this second step, only the condensed polycyclic aromatic hydrocarbon (B) having a phenolic hydroxyl group may be used, but if necessary, the known and commonly used phenols used in the first step may be used in combination therewith. There is absolutely no problem with that. However, it is preferable from the viewpoint of physical properties to use as much of the aromatic hydrocarbon (B) component as possible.

Also in the second step, it is preferable that the methylol group equivalent of the resol type phenolic resin (A) and the nuclear hydrogen equivalent of the aromatic hydrocarbon (B) be made equal. When using other phenols in addition to the aromatic hydrocarbon (B) in this second step, resol type phenolic resin (
It is preferable to match the methylol group equivalent of A) with the total nuclear hydrogen equivalent of the aromatic hydrocarbon (B) and other phenols.

Examples of the aromatic hydrocarbon (B) include α-naphthol, β-naphthol, dihydroxynaphthalene, and the like.

In the second step, the methylol group of the resol type phenol resin (A) obtained in the first step and the aromatic hydrocarbon (B) are combined.
The reaction is carried out by reacting these in the presence of an acidic catalyst.

As the acidic catalyst used in the second step of the present invention, any known and commonly used catalyst used in the production of novolac type phenolic resins can be used. Suitable examples of such acidic catalysts include formic acid, phosphoric acid, p-toluenesulfonic acid, phenolsulfonic acid, hydrochloric acid, sulfuric acid, and phosphoric acid.

The reaction in the second step can be carried out without a solvent, or in the presence of an organic solvent to reduce the viscosity of the reaction system. The organic solvent that can be used at that time is not particularly limited, but
Examples include benzene, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, ethyl cellosolve, butyl cellosolve, ethyl carpitol and the like.

The amount of the acidic catalyst used in the second step is not limited, but it is usually the weight at which the pH of the mixture of renyl-type fer resin (A) and aromatic hydrocarbon (B) is 4 or less; That is, the weight is such that the pH of the reaction system is 4 or less, and the pH is 2 to 3.
It is particularly preferred to use an acidic catalyst having a weight of 5.

The reaction temperature is in the range of 40 to 200 °C, preferably 5
The temperature is 0 to 180°C. The reaction temperature does not need to be isothermal throughout the second step.

In this case, the higher the reaction temperature, the faster the reaction will proceed,
If the temperature is raised rapidly, the reaction within the system will proceed too quickly, which is dangerous, so a reaction method in which the temperature is held at around 100'C for a predetermined period of time and then the temperature is raised is preferred.

Further, when this condensation reaction is carried out at a temperature exceeding 100°C, it is preferable to carry out the reaction while distilling.

After the completion of the second step, unreacted phenols remaining in the obtained novolac resin are removed as necessary by conventional methods such as distillation, vacuum distillation, and steam distillation to obtain the novolac resin according to the present invention. I can do it.

The novolak type aromatic hydrocarbon-formaldehyde resin according to the present invention obtained in this way can be used in adhesives, paints, etc.
It can be used for applications such as molding materials and various binders.

For example, in combination with a hardening agent such as hexamethylenetetramine, it can be used as a binder for foundry sand, a binder for abrasives, a binder for filters, a binder for prepregs, a binder for refractories, a binder for carbon materials, etc. . It can also be used as a curing agent for epoxy resins.

The novolac type aromatic hydrocarbon-formaldehyde resin of the present invention can be mixed with an epoxy resin and cured by heating to obtain a cured product with excellent physical properties.

As the epoxy resin in this case, any known and commonly used epoxy resin can be used; for example, a polyglycidyl ether type epoxy resin obtained by reacting a polyhydric phenol such as bisphenol A1, halogenated bisphenol A, or resorcinol with epichlorohydrin; Ebogyo dinovolac resin obtained by reacting novolac phenol resin and epichlorohydrin, Evogyosilicated olefins or epoxidized polybutageno obtained by epoxidizing unsaturated bonds by a peroxidation method, or amine compound and epichlorohydrin. Examples include glycidylamine-based epoxy resins obtained by reaction.

In obtaining the epoxy resin composition of the present invention, when the number of epoxy groups in the above epoxy resin is 1, the number of hydroxyl groups in the novolak type aromatic hydrocarbon-formaldehyde resin obtained in the present invention is 0. Both of these resins may be blended within the range of 5 to 1.5.

Of course, the novolak resin obtained in the present invention may be used in combination with other curing agents such as phenol novolak resin, cresol novolac resin, polyamide amine, dicyandiamide, acid anhydride, low molecular polyamine, Mannhich condensate, etc. good.

The epoxy resin composition of the present invention may contain various curing accelerators generally used for curing epoxy resins, if necessary. Such curing accelerators include:
For example, imidazoles such as imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl4-methylimidazole, 2-phenylimidazole or N-butylimitasol, benzyldemethylamine, triethylamine, N-aminopiperazine, bis (
4-amino-3-methylcyclohexyl)methane or 3,9-bis(3-aminopropyl)-2,4°8
．． Amine compounds such as 10-tetraoxaspiro(5,5) lanthican, or triethylamine and BF,
Examples include BF, salts, and triphenylphosphine. The amount of the curing accelerator used is not particularly limited, but it is usually 0.02% of the epoxy resin.
Approximately 2% by weight is appropriate.

In the epoxy resin composition according to the present invention, when a 7-borac resin polyglycidyl ether type epoxy resin such as a phenol novolac type epoxy resin or a cresol novolac type epoxy resin is selected as the epoxy resin,
In particular, the curable epoxy resin composition can be made suitable as a molding material for semiconductor encapsulating materials and the like.

The epoxy resin composition of the present invention may contain additives such as fillers, mold release agents, colorants, plasticizers, coupling agents, and flame retardants as appropriate. Fillers such as silica, talc, alumina, calcium carbonate or glass fibers, mold release agents such as stearic acid, zinc stearate or synthetic waxes, and coloring agents such as pigments such as carbon black. Or various dyes, plasticizers such as silicone oil, coupling agents such as aminosilane, epoxysilane, vinylane, etc., and flame retardants such as decabromobisphenol A1, tetrabromobisphenol digly/rin ether, and phosphoric acid compounds. Examples include.

<Example> Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples. In the following, "parts" and "%" all mean parts by weight unless otherwise specified. shall be.

Example 1 362 parts of orthocresol, 36 parts of sodium hydroxide
1 part was placed in a flask, and 484 parts of 42% formalin were gradually added thereto while maintaining the temperature at 50°C. After maintaining the same temperature for 4 hours, hydrochloric acid was added little by little to neutralize the system to pH 7. Next, after adding 400 parts of water, the aqueous layer was removed and separated by washing with water. Further, water washing and separation were performed using 400 parts of water for each of the four samples to obtain a resol type phenol resin solution (A-1,). This resol type phenol resin solution (A-1) had a methylol group equivalent of 134 and a nonvolatile content of 62%.

Next, this resol type phenolic resin solution (A-1)
200 parts of butyl cellosolve and 742 parts of β-naphthol were added to the mixture, and 1.5 parts of 7-euric acid were added to make 8.
It was heated to 0°C to uniformly dissolve it. The pH of the reaction system at this time was 2.5.

This was heated to 100°C, held for 2 hours, and then heated to 200°C while distilling. Distillation was carried out under reduced pressure at 200'C for 2 hours at a reduced pressure of 5 mmHg to obtain the desired novolac-type aromatic hydrocarbon-formaldehyde resin.
Obtained 000 copies. Hereinafter, this novolac resin will be abbreviated as C-1, and its properties are shown in Table 1. The softening point is the value measured by the ring and ball method at a heating rate of 3°C per minute, and the hydroxyl equivalent of the borac-type aromatic hydrocarbon-formaldehyde resin is the value determined by carbon-13 nuclear magnetic resonance spectroscopy, which is one phenolic hydroxyl group. The average molecular weight per unit was calculated and then determined.

Example 2 181 parts of orthocresol and 482 parts of β-naphthol were added to the resol type phenolic resin melt e (A-1) obtained in the same manner as in Example 1, and 1 part of oxalic acid was added to the solution.
．． After adding 5 parts, the same procedure as in Example 1 was carried out to obtain 1000 parts of the desired novolak type aromatic hydrocarbon-formaldehyde resin.

Hereinafter, this novolac resin will be abbreviated as C-2, and its properties are shown in Table 1.

Example 3 Resol-type fluorine obtained in the same manner as in Example 1
362 parts of orthocresol and β were added to the fat solution (A-1).
- 241 parts of naphthol and 241 parts of α-suphthol
1000 parts of the desired novolak type aromatic hydrocarbon-formaldehyde resin was obtained in the same manner as in Example 1 by adding 1.5 parts of oxalic acid. Hereinafter, this novolak resin will be abbreviated as C-3, and its properties are shown in Table 1.

Example 4 362 parts of orthocresol and β-
Adding 294 parts of naphthol and 239 parts of 1,6-cyhydroquine naphthalene, and further adding 1.5 parts of oxalic acid, the following procedure was repeated in the same manner as in Example 1 to obtain the desired noholac-type aromatic hydrocarbon-formaldehyde resin. 1,000 copies were obtained.

Hereinafter, this novolak resin will be abbreviated as C-4, and its properties are shown in Table 1.

Comparative Example 1 616 parts of orthocresol was added to the resol type phenol resin solution (A-1) obtained in the same manner as in Example 1, and 1.5 parts of oxalic acid was added, and the following Example 1 was prepared. In the same manner as above, 1000 copies of the desired Nohora Ri were obtained.

Hereinafter, this novolac resin will be abbreviated as C-5 [-1] Its properties are shown in Table 1.

Examples 5 to 8 and Comparative Examples 2 to 3 Nophoranok-type aromatic hydrocarbon-formaltehyde resin or Barkum TD obtained in Examples 1 to 4 and Comparative Example 1
-2093 (phenol novolac resin manufactured by Inu Nippon Ink Chemical Industries, Ltd.), Epiclon N-673 (phenol novolac type epoxy resin manufactured by Dainippon Ink Chemical Industries, Ltd.) and 2-ethyl-4-methyl imitasol. 2. Mix the specified amount shown in Table 2 and heat at 140'C to 150°C.
A thermosetting epoxy resin composition is prepared by uniformly heating and melting and blending, and then using each composition, J
It is cast according to the method of boiling water absorption test (for molding materials) of ISK-6911, and then each cast disc is
It was cured by heat treatment at 70°C for 2 hours.

In this way, the water absorption after boiling for 1 hour was determined for 5 samples from each epoxy resin composition according to JISK-6911 boiling water absorption test (molding materials), and the average value of the 5 samples was determined. Table 2 shows the results of the rate test.

On the other hand, using each of the above Epoquine compositions, a thickness of 5.
It was poured into a plate shape with a thickness of 2 mm and then heated at 170°C
It was cured by heat treatment for a period of time.

Thereafter, the glass transition temperature of each cured product was measured as a heat resistance test. The results of the boiling water absorption test (which is a measure of water resistance) and the glass transition temperature (which is a measure of heat resistance) are shown in Table 2.

As can be seen from Table 1 and Table 2, the cured epoxy resin obtained by using the novolak type aromatic hydrocarbon-formaldehyde resin obtained by the production method of the present invention as a curing agent is different from that of the conventional one. It can be seen that it is significantly superior in terms of water resistance compared to hardening agents.

<Effects of the Invention> In the production method of the present invention, in the production method of a novolac type aromatic hydrocarbon-formaldehyde resin in which a resol type phenol resin and a phenol are reacted, the phenol is a fused polycyclic resin having a phenolic hydroxyl group. Since aromatic hydrocarbons are used, the obtained Nophora-type aromatic hydrocarbon-formaldehyde resin is the same as the conventional Nohora-type aromatic hydrocarbon-formaldehyde resin.

Compared to the aromatic hydrocarbon-formaltehyde resin,
For example, when used as an epoxy resin curing agent, a particularly remarkable effect can be obtained in that a cured epoxy resin product having extremely excellent water resistance can be obtained.

Agent: Patent Attorney Katsutoshi Takahashi

Claims (1)

[Claims] 1. A novolak-type aromatic hydrocarbon characterized by reacting a resol-type phenolic resin (A) with a condensed polycyclic aromatic hydrocarbon (B) having a phenolic hydroxyl group.
Method for producing formaldehyde resin. 2. The production method according to claim 1, wherein the resol type phenolic resin (A) is obtained by reacting phenols and aldehydes in the presence of a basic catalyst. 3. The manufacturing method according to claim 2, wherein the phenol is an alkylphenol. 4. The manufacturing method according to claim 1, wherein the reaction between the resin (A) and the hydrocarbon (B) is carried out in the presence of an acid catalyst. 5. An epoxy resin curing agent comprising a novolak aromatic hydrocarbon-formaldehyde resin obtained by reacting a resol type phenolic resin (A) with a condensed polycyclic aromatic hydrocarbon having a phenolic hydroxyl group (B). 6. In an epoxy resin composition consisting of an epoxy resin and a curing agent, the curing agent is obtained by reacting a resol type phenolic resin (A) with a condensed polycyclic aromatic hydrocarbon (B) having a phenolic hydroxyl group. An epoxy resin composition characterized in that it uses a novolak type aromatic hydrocarbon-formaldehyde resin.