JP2007224152A - Two-pack type phenolic resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a two-pack type phenolic resin composition having a long pot life and excellent in cure characteristics when a phenolic resin, excellent in stability with time and storage and handleability under ordinary temperature, and a curing agent are mixed and used. <P>SOLUTION: The composition is formed by mixing an alkyl-etherified phenolic resin (a) having a methyl ether group and a methylol group bonded to a phenolic ring and an acid compound (b) as the curing agent. In the above alkyl-etherified phenolic resin (a), the ratio of the etherification by the above methyl ether group is preferably ≥50 mol% to the total of the methyl ether group and the methylol group. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a two-component phenol resin composition.

Phenolic resin compositions are used in many fields such as molding materials, laminates, friction materials, grindstones, polishing cloths, refractories, paints, and binders for various substrates. Examples of the phenolic resin include novolak-type phenolic resins and resol-type phenolic resins. Among them, resol-type phenolic resins are liquid, solid, or pulverized solids and are commercialized as powders. Among these, liquid products are often used.
As a method for curing the resol type phenol resin, a method by heating without using a curing agent and a method by a two-component type in which an acidic compound or the like is used as a curing agent are known.

On the other hand, the resol type phenol resin usually undergoes a polycondensation reaction gradually in the temperature range (30 to 40 ° C.) assuming a normal temperature in summer, and the molecular weight increases to increase the viscosity. Generally, up to about twice the viscosity immediately after production is within the usable range, but when the reaction further proceeds, it finally gels through a viscous liquid.
For this reason, it is necessary to store at 10 ° C. or less, preferably 5 ° C. or less by a refrigeration apparatus or the like at the time of storage and transportation, resulting in an increase in equipment cost and maintenance management cost.

As a technique for improving the storage stability of a resol-type phenolic resin, it has been disclosed that the change with time is the smallest at around pH 5 (for example, see Non-Patent Document 1).
In addition, a technique for improving storage stability by using a specific neutralizing agent such as using an acidic phosphate ester as a neutralizing agent is also disclosed (for example, see Patent Documents 1 and 2).

  In addition, it is known to suppress reactivity by etherifying a methylol group. As a general etherification method, it is known that methylol groups are etherified to form a dimethylene ether bond (see, for example, Non-Patent Document 2, Patent Documents 3 and 4).

Also, a technique for blocking a methylol group by reacting a monoalcohol such as butanol with a methylol group mainly for coating applications has been disclosed (for example, see Non-Patent Document 3).
Moreover, the technique about the method of ethyl-ether-izing using ethanol is also disclosed (for example, refer patent document 5, 6).

  However, in spite of the above-described studies, further improvement is desired for a phenol resin composition having excellent stability over time, storage and handling at room temperature, and fast curing speed. Yes.

  On the other hand, in the case of the two-component type in which an acidic compound is used as a curing agent, the above-mentioned stability over time cannot be solved, and the pot life is short and the handling is difficult.

Polmer ENGINEERING SCIENCE Vol. 27 No. 13; P976-978 (1987/07) Phenolic Resin Chemistry, P49-52, July 10, 1987 2nd Edition, Plastics Age Andre Knop, Louis A. Translated by Pirate, Shoji Seto Phenolic Resin Chemistry, P128-129, July 10, 1987 2nd Edition, Plastics Age Andre Knop, Louis A. Translated by Pirate, Shoji Seto JP 54-64588 A JP 11-26934 A JP-A-51-73094 JP-A-52-108492 JP 58-67712 A JP-A-54-65699

  The present invention is a two-component phenolic resin composition having a long pot life and excellent curing characteristics when a phenolic resin excellent in stability over time, storage and handling at room temperature, and a curing agent are mixed. Is intended to provide.

Such an object is achieved by the following present inventions (1) to (10).
(1) A two-component phenol resin comprising an alkyl etherified phenol resin (a) having a methyl ether group and a methylol group bonded to a phenol ring, and an acidic compound (b) as a curing agent. Composition.
(2) The alkyl etherified phenol resin (a) has a methyl etherification rate of the methyl ether group of 50 mol% or more based on the total of the methyl ether group and the methylol group. Two-component phenolic resin composition.
(3) The two-component phenol resin composition according to claim 1 or 2, wherein the alkyl etherified phenol resin (a) has a weight average molecular weight of 100 to 20,000.
(4) The two-component phenol resin composition according to any one of claims 1 to 3, wherein the acidic compound (b) contains an inorganic acid and / or an organic acid.
(5) The acidic compound (b) has a dissociation multiplier pKa of 2 or less (the two-component phenol resin composition according to any one of 1 to 4).
(6) The two-component phenol resin composition according to any one of claims 1 to 5, wherein the acidic compound (b) contains succinic acid and / or p-toluenesulfonic acid.
(7) The two-component phenolic resin composition according to any one of claims 1 to 6, wherein the acidic compound (b) releases an acidic substance having a dissociation constant pKa of 2 or less.
(8) The thermal decomposition temperature at which the acidic compound (b) releases an acidic substance having a dissociation constant pKa of 2 or less is 120 to 150 ° C. The two-component phenol according to any one of claims 1 to 7 Resin composition.
(9) The two-component phenol resin composition according to any one of claims 1 to 8, wherein the acidic compound (b) contains cyclohexyl aromatic sulfonates.
(10) The two-component phenol resin composition according to any one of claims 1 to 9, wherein the acidic compound (b) contains cyclohexyl benzenesulfonate.

According to the present invention, a two-component phenol resin composition having a long pot life and excellent curing characteristics can be obtained using a phenol resin excellent in stability over time and storage and handling at room temperature.
Also,

  The present invention is a phenol resin composition comprising an alkyl etherified phenol resin (a) having a methyl ether group and a methylol group bonded to a phenol ring, and further mixed with an acidic compound (b) as a curing agent. A two-component phenolic resin composition characterized by

Hereinafter, the two-component phenolic resin composition of the present invention (hereinafter sometimes simply referred to as “composition”) will be described.
The composition of the present invention is characterized by using an alkyl etherified phenol resin (a).
The alkyl etherified phenol resin (a) is obtained by reacting methanol with a phenol resin having a methylol group bonded to a phenol ring, and the methyl ether group has a methyl etherification rate of the methyl ether group. It is preferable that it is 50 mol% or more with respect to the sum total of a methylol group. Thereby, the activity of a methylol group can be suppressed and stability over time can be improved. When this methyl etherification rate is less than 50 mol%, for example, the temporal stability under a temperature condition of 30 to 40 ° C may be lowered.
Therefore, for such purposes, the methyl etherification rate of the methyl ether group is more preferably 80 mol% or more. Thereby, stability with time can be further improved.

In addition, the methyl etherification rate of the methyl ether group with respect to the sum total of the said methylol group and methyl ether group can be measured with a NMR apparatus.
Specifically, for example, an alkyl etherified phenol resin is acetylated, measured with a 1H-NMR apparatus, and the chemical shift portion of the terminal methyl group of the methylol group, ether group, or methyl ether group bonded to the phenol ring is measured. It can be calculated from the integral value.

As described above, a phenol resin having a methylol group bonded to a phenol ring is obtained by reacting phenols with formaldehyde in the presence of a basic catalyst. This phenol resin has a form in which a methylene group and a dimethylene ether group are bonded to a phenol ring in addition to a methylol group.
Of these linking groups, it is mainly methylol groups that contribute to the curing reaction when phenol resins are used, but methylol groups have high reaction activity, so that the time-dependent change of phenol resins having methylol groups is suppressed. It was necessary to store and handle at low temperature.

  The alkyl etherified phenol resin (a) is obtained by methyl etherifying this methylol group with methanol. The methyl ether group is a state in which the methylol group is blocked by methyl etherification, and can suppress a change with time under a temperature condition of 30 to 40 ° C. The pH is neutral even at 100 ° C. or less. If the curing agent does not coexist, the stability is high. On the other hand, by adding a curing agent such as an acidic compound at the time of use, this block can be easily removed and the intended curing reaction can be performed.

The weight average molecular weight of the alkyl etherified phenol resin (a) is preferably 100 to 20000. More preferably, it is 200-5000.
Since particularly good curing reaction proceeds by setting the weight average molecular weight within the above range, the mechanical strength and heat resistance of the cured product can be improved. The effect which improves property can be heightened.

In addition, the said weight average molecular weight is measured on condition of the following by the gel permeation chromatography method.
1) Device body: “HLC-8120” manufactured by TOSOH
2) Analysis column: manufactured by TOSOH (G1000HXL: 1, G2000HXL: 2, G3000HXL: 1)
Was subjected to GPC measurement using a differential refractometer as a detector under the analysis conditions of a flow rate of 1.0 ml / min, elution solvent tetrahydrofuran and a column temperature of 40 ° C., and the molecular weight was converted by standard polystyrene.

  Although the said alkyl etherified phenol resin (a) is not specifically limited, For example, it can manufacture by the following methods. Phenols and aldehydes are reacted in the presence of a basic catalyst to synthesize a resol-type phenol resin mainly containing methylol groups, pH is adjusted to 2 to 8 using an acidic substance, methanol is added, and methylol groups And a methylol group.

The composition of the present invention is characterized by containing an acidic compound (b).
As the acidic compound (b) used in the present invention, an inorganic acid and / or an organic acid can be used. By using these, the resin can be cured particularly by heating.
Examples of the inorganic acid include sulfuric acid (pKa = 1.6) and phosphoric acid (pKa = 2.1), and it is preferable to use phosphoric acid from the viewpoint of curing speed.
Examples of the organic acid include p-toluenesulfonic acid (pKa = 1.7) formic acid (pKa = 3.8), oxalic acid (pKa = 1.3), and p-toluenesulfone from the viewpoint of curing speed. It is preferable to use an acid (pKa = 1.7).

The acidic compound (b) preferably has a dissociation multiplier pKa of 2 or less. More preferably, it is 0.5-2.
By setting the dissociation multiplier pKa in the above range, a sufficient sufficient curing speed can be obtained particularly at the time of heat curing, and the restriction on the material of the container and mold used for heat curing from the point of corrosion can be reduced.

  The acidic compound (b) preferably contains oxalic acid and / or p-toluenesulfonic acid. By using these alone or in combination, the curing speed of the resin can be increased particularly by heating, and the corrosion that is not limited by the material of the container and mold used for thermosetting from the point of corrosion by acid is minimized. Can be suppressed.

The acidic compound (b) is preferably capable of releasing an acidic substance having a dissociation multiplier pKa of 2 or less. Examples of the acidic substance include the organic acids described above, and any compound that releases them by thermal decomposition is preferable, and cyclohexyl aromatic sulfonate is preferable. Among these, cyclohexyl benzenesulfonate that releases p-toluenesulfonic acid is particularly preferable.
By releasing an acidic substance by thermal decomposition, the pot life at the time of mixing an acidic compound at a normal temperature is long, a sufficient curing rate can be obtained at the time of heat curing, and the dissociation multiplier pKa is in the above range. In particular, a sufficient curing rate can be obtained during heat curing.

  The thermal decomposition temperature at which the acidic compound (b) releases an acidic substance having a dissociation multiplier pKa of 2 or less is preferably 120 to 150 ° C. By making the temperature of the thermal decomposition within the above range, adverse effects such as thickening due to aging at the time of compounding acidic compounds at normal temperature can be inhibited, pot life can be lengthened, and sufficient curing speed can be obtained even during heat curing. .

  Examples of the cyclohexyl sulfonates include cyclohexyl = 4-methylbenzenesulfonate, 2-methylcyclohexyl = 4-methylbenzenesulfonate, 3-methylcyclohexyl = 4-methylbenzenesulfonate, 4-methylcyclohexyl = 4-methyl. Benzenesulfonate, 4-butylcyclohexyl = 4-methylbenzenesulfonate, 4-cyclohexylcyclohexyl = 4-methylbenzenesulfonate, 2,6-dimethylcyclohexyl = 4-methylbenzenesulfonate, 2,4-dimethylcyclohexyl = 4-methylbenzenesulfonate 3,4-dimethylcyclohexyl 4-methylbenzenesulfonate, 3,5-dimethylcyclohexyl 4-methylbenzenesulfonate, 2-isopropyl Pyr-5-methylcyclohexyl = 4-methylbenzenesulfonate, 2-hydroxycyclohexyl = 4-methylbenzenesulfonate, 4-hydroxycyclohexyl = 4-methylbenzenesulfonate, cyclohexyl = 4-biphenylsulfonate and 4,4′-bicyclohexyl = Benzylsulfonate cyclohexyls such as bis (4-methylbenzenesulfonate), and cyclohexyl naphthalenesulfonates such as cyclohexyl = 1-naphthalenesulfonate and cyclohexyl = 2-naphthalenesulfonate can be used, and among these, benzenesulfonic acid Hexyls are preferred, and further cyclohexyl = 4-methylbenzenesulfonate, 3-methylcyclohexyl = 4-methylbenzenesulfonate, 3,5-di Tylcyclohexyl 4-methylbenzene sulfonate, 4-butylcyclohexyl 4-methylbenzene sulfonate, 2-isopropyl-5-methylcyclohexyl 4-methylbenzene sulfonate, 2-hydroxycyclohexyl 4-methylbenzene sulfonate and 4-hydroxycyclohexyl = 4-methylbenzenesulfonate is preferred, and cyclohexyl = 4-methylbenzenesulfonate is particularly preferred.

  Examples of the cyclohexyl benzenesulfonates include cyclohexyl = 4-methylbenzenesulfonate, 3-methylcyclohexyl = 4-methylbenzenesulfonate, 3,5-dimethylcyclohexyl = 4-methylbenzenesulfonate, 4-butylcyclohexyl = 4- Examples include methylbenzene sulfonate, 2-isopropyl-5-methylcyclohexyl = 4-methylbenzene sulfonate, 2-hydroxycyclohexyl = 4-methylbenzene sulfonate, 4-hydroxycyclohexyl = 4-methylbenzene sulfonate, and the like. Among these, cyclohexyl = 4-methylbenzenesulfonate is particularly preferable from the viewpoint of curing speed.

  The content of the acidic compound (b) in the present invention is 0.1 to 10 parts by weight with respect to 100 parts by weight of the alkyl etherified phenol resin (a). By setting the content of the acidic compound (b) within the above range, a sufficient curing rate can be obtained particularly at the time of thermosetting by heating, and the restriction on the material of the container and mold used for thermosetting from the point of corrosion is reduced. be able to.

  The method of using the two-component phenolic resin composition of the present invention is not particularly limited, but an alkyl etherified phenolic resin (a) and an acidic compound (b) and, if necessary, other additives such as a filler as a stirrer A known method of mixing with a mixer or the like can be used.

Moreover, as a filler, an inorganic filler, an organic filler, etc. can be used.
The inorganic filler is not particularly limited. For example, silicates such as talc and calcined clay, oxides such as alumina, silica and fused silica, calcium carbonate and carbonates such as hydrotalcite, aluminum hydroxide, Examples thereof include hydroxides such as magnesium hydroxide, sulfates or sulfites such as barium sulfate and calcium sulfite, borates such as zinc borate, and nitrides such as aluminum nitride and silicon nitride.
Further, the organic filler is not particularly limited, but for example, various thermosetting resins such as phenol resin, epoxy resin, acrylic resin, polyamide, polysulfone, polystyrene, fluororesin or powder of thermoplastic resin, or these resins. Examples thereof include powdery organic fillers such as copolymers, and fibrous organic fillers such as wood flour, pulp, kenaf, aramid fibers, and polyester fibers.

  Hereinafter, the present invention will be described in detail with reference to examples. Here, “parts” indicates “parts by weight” and “%” indicates “% by weight”.

1. Preparation of resol type phenol resin solution <Production Example 1>
In a 5 L three-necked flask equipped with a stirrer and a thermometer, 1000 parts of phenol, 1725 parts of a 37% formaldehyde aqueous solution (corresponding to 2.0 moles per mole of phenol) and 100 parts of barium hydroxide were added. The mixture was reacted at 70 ° C. for 1 hour to synthesize a resol type phenol resin.
Next, the reaction system was neutralized using a 25% aqueous sulfuric acid solution and adjusted to pH = 4.5.
Thereafter, the pressure of the reaction system was reduced to 5000 Pa, the temperature was raised to 70 ° C., and distillation was performed under reduced pressure. After dehydration until the water content in the reaction system became 2.0%, 1021 parts of methanol (1 mol of phenols) 2 mol parts of resol type phenol resin solution A was obtained.

<Production Example 2>
In a 5 L three-necked flask equipped with a stirrer and a thermometer, 1000 parts of phenol, 1725 parts of a 37% formaldehyde aqueous solution (corresponding to 2.0 moles per mole of phenol) and 100 parts of barium hydroxide were added. The mixture was reacted at 80 ° C. for 2 hours to synthesize a resol type phenol resin.
Next, the reaction system was neutralized using a 25% aqueous sulfuric acid solution and adjusted to pH = 4.5.
Thereafter, the pressure of the reaction system was reduced to 5000 Pa, the temperature was raised to 70 ° C., and distillation was performed under reduced pressure. After dehydration until the water content in the reaction system became 2.5%, 1021 parts of methanol (1 mol of phenols) 2 mol parts of a resol type phenol resin solution B was obtained.

<Production Example 3>
In a 5 L three-necked flask equipped with a stirrer and a thermometer, 1000 parts of phenol, 1725 parts of a 37% formaldehyde aqueous solution (corresponding to 2.0 moles per mole of phenol) and 100 parts of barium hydroxide were added. The mixture was reacted at 90 ° C. for 3 hours to synthesize a resol type phenol resin.
Next, the reaction system was neutralized using a 25% aqueous sulfuric acid solution and adjusted to pH = 4.5.
Thereafter, the pressure of the reaction system was reduced to 5000 Pa, the temperature was raised to 70 ° C., and distillation was performed under reduced pressure. After dehydration until the water content in the reaction system became 3.0%, 1021 parts of methanol (1 mol of phenols) To 2 mol of resol-type phenolic resin solution C.

<Production Example 4>
In a 5 L three-necked flask equipped with a stirrer and a thermometer, 1000 parts of phenol, 1725 parts of a 37% formaldehyde aqueous solution (corresponding to 2.0 moles per mole of phenol) and 100 parts of barium hydroxide were added. The mixture was reacted at 70 ° C. for 1 hour to synthesize a resol type phenol resin.
Next, the reaction system was neutralized using a 25% aqueous sulfuric acid solution and adjusted to pH = 4.5. The water content in the reaction system was 40.0%. Subsequently, 1021 parts of methanol (corresponding to 3.0 moles per mole of phenols) was added to obtain D3841 parts of a resol type phenol resin solution.

2. Production of alkyl etherified phenol resin <Production Example 5>
In a 1 L autoclave equipped with a stirrer, 276 parts of the resol-type phenol resin solution A obtained in Production Example 1 and 306 parts of methanol (methanol amount: equivalent to 12.0 moles per mole of phenols) are placed. The temperature was raised, and the mixture was reacted at 150 ° C. for 1 hour, and then cooled.
The obtained resin was taken out and placed in a 1 L three-necked flask equipped with a stirrer and a thermometer. Thereafter, vacuum distillation was performed at a reduced pressure of 5000 Pa, the viscosity was adjusted to 105 mPa · s, and E179 parts of an alkyl etherified phenol resin E was obtained.

<Production Example 6>
In a 1 L autoclave equipped with a stirrer, 276 parts of the resol-type phenol resin solution A obtained in Production Example 1 and 306 parts of methanol (methanol amount: equivalent to 12.0 moles per mole of phenols) are placed. The temperature was raised, and the mixture was reacted at 130 ° C. for 1 hour, and then cooled.
The obtained resin was taken out and placed in a 1 L three-necked flask equipped with a stirrer and a thermometer. Thereafter, vacuum distillation was performed at a reduced pressure of 5000 Pa, the viscosity was adjusted to 98 mPa · s, and an alkyl etherified phenol resin F195 part was obtained.

<Production Example 7>
In a 1 L autoclave equipped with a stirrer, 276 parts of the resol-type phenol resin solution A obtained in Production Example 1 was added, the temperature was raised, the reaction was carried out at 150 ° C. for 1 hour, and then cooled.
The obtained resin was taken out and placed in a 1 L three-necked flask equipped with a stirrer and a thermometer. Thereafter, vacuum distillation was performed at a reduced pressure of 5000 Pa, the viscosity was adjusted to 102 mPa · s, and 180 parts of an alkyl etherified phenol resin G was obtained.

<Production Example 8>
In a 1 L autoclave equipped with a stirrer, 274 parts of the resol type phenolic resin solution B obtained in Production Example 2 and 306 parts of methanol (methanol amount: equivalent to 12.0 moles per mole of phenols) are placed. The temperature was raised, and the mixture was reacted at 150 ° C. for 1 hour, and then cooled.
The obtained resin was taken out and placed in a 1 L three-necked flask equipped with a stirrer and a thermometer. Thereafter, vacuum distillation was performed at a reduced pressure of 5000 Pa, the viscosity was adjusted to 102 mPa · s, and 198 parts of an alkyl etherified phenol resin H was obtained.

<Production Example 9>
In a 1 L autoclave equipped with a stirrer, 274 parts of the resol type phenolic resin solution B obtained in Production Example 2 and 306 parts of methanol (methanol amount: equivalent to 12.0 moles per mole of phenols) are placed. The temperature was raised, and the mixture was reacted at 130 ° C. for 1 hour, and then cooled.
The obtained resin was taken out and placed in a 1 L three-necked flask equipped with a stirrer and a thermometer. Thereafter, vacuum distillation was performed at a reduced pressure of 5000 Pa, the viscosity was adjusted to 99 mPa · s, and I223 parts of an alkyl etherified phenol resin was obtained.

<Production Example 10>
Into a 1 L autoclave equipped with a stirrer, put 277 parts of the resol type phenol resin solution C obtained in Production Example 3 and 306 parts of methanol (methanol amount: equivalent to 12.0 moles per mole of phenols). The temperature was raised, and the mixture was reacted at 150 ° C. for 1 hour, and then cooled.
The obtained resin was taken out and placed in a 1 L three-necked flask equipped with a stirrer and a thermometer. Thereafter, vacuum distillation was performed at a reduced pressure of 5000 Pa, and the viscosity was adjusted to 100 mPa · s to obtain J179 part of an alkyl etherified phenol resin.

<Production Example 11>
In a 1 L autoclave equipped with a stirrer, 384 parts of the resol-type phenol resin solution obtained in Production Example 4 and 306 parts of methanol (methanol amount: equivalent to 12.0 moles per mole of phenols) are placed. The temperature was raised, and the mixture was reacted at 150 ° C. for 1 hour, and then cooled.
The obtained resin was taken out and placed in a 1 L three-necked flask equipped with a stirrer and a thermometer. Thereafter, vacuum distillation was performed at a reduced pressure of 5000 Pa, the viscosity was adjusted to 103 mPa · s, and 180 parts of an alkyl etherified phenol resin was obtained.

<Production Example 12>
Into a 1 L autoclave equipped with a stirrer, 274 parts of the resol-type phenol resin solution A obtained in Production Example 1 was placed and distilled under reduced pressure at a reduced pressure of 5000 Pa to adjust the viscosity to 100 mPa · s. A type phenol resin L210 part was obtained.

<Production Example 13>
Into a 1 L autoclave equipped with a stirrer, 274 parts of the resol-type phenolic resin solution B obtained in Production Example 2 was placed and distilled under reduced pressure at a reduced pressure of 5000 Pa to adjust the viscosity to 102 mPa · s. Type phenol resin M241 part was obtained.

<Production Example 14>
To a 1 L autoclave apparatus equipped with a stirrer, 277 parts of the resol type phenol resin solution C obtained in Production Example 3 was added, distilled under reduced pressure at a reduced pressure of 5000 Pa, and the viscosity was adjusted to 105 mPa · s, Resol type phenol resin N268 parts was obtained.

<Production Example 15>
In a 1 L autoclave equipped with a stirrer, 276 parts of the resol-type phenol resin solution A obtained in Production Example 1 and 306 parts of methanol (methanol amount: equivalent to 12.0 moles per mole of phenols) are placed. The temperature was raised and the reaction was carried out at 90 ° C. for 5 hours, followed by cooling.
The obtained resin was taken out and placed in a 1 L three-necked flask equipped with a stirrer and a thermometer. Thereafter, vacuum distillation was performed at a reduced pressure of 5000 Pa, and the viscosity was adjusted to 105 mPa · s to obtain 202 parts of an alkyl etherified phenol resin.

<Production Example 16>
In a 1 L autoclave equipped with a stirrer, 276 parts of the resol-type phenol resin solution A obtained in Production Example 1 and 306 parts of methanol (methanol amount: equivalent to 12.0 moles per mole of phenols) are placed. The temperature was raised, and the mixture was reacted for 24 hours under reflux conditions, and then cooled.
The obtained resin was taken out and placed in a 1 L three-necked flask equipped with a stirrer and a thermometer. Thereafter, vacuum distillation was performed at a reduced pressure of 5000 Pa, the viscosity was adjusted to 99 mPa · s, and P205 part of an alkyl etherified phenol resin was obtained.

<Production Example 17>
Into a 1 L autoclave equipped with a stirrer, put 277 parts of the resol type phenol resin solution C obtained in Production Example 3 and 306 parts of methanol (methanol amount: equivalent to 12.0 moles per mole of phenols). The temperature was raised and the reaction was carried out at 90 ° C. for 5 hours, followed by cooling.
The obtained resin was taken out and placed in a 1 L three-necked flask equipped with a stirrer and a thermometer. Thereafter, vacuum distillation was performed at a reduced pressure of 5000 Pa, the viscosity was adjusted to 98 mPa · s, and Q203 parts of an alkyl etherified phenol resin was obtained.

  Table 1 shows the characteristics and changes with time of the alkyl etherified phenol resins obtained in Production Examples 5 to 17.

<Evaluation method>
(1) Water content About the water content in the resol type phenol resin solution obtained by manufacture examples 1-4, and the water content in the reaction system at the time of the methyl etherification reaction start in manufacture examples 5-17, JIS According to K 0068, the measurement was performed by the Karl Fischer method.

(2) Amount of methanol The amount of methanol in the reaction system at the start of the methyl etherification reaction was calculated from the amount charged, and expressed as a molar ratio relative to the starting phenol.

(3) Viscosity Based on JIS K 6909, it measured at 25 degreeC using the synchronous electric rotational viscometer.

(4) Resin content In accordance with JIS K 6909, about 2 ml of liquid phenolic resin is placed in an aluminum foil container, and the ratio of the resin content (solid content) from the remaining amount after heating in a drying device at 135 ° C. for 1 hour. Was calculated.

(5) Number average molecular weight, weight average molecular weight It measured using the liquid chromatography method.
The liquid chromatography method uses GPC (gel permeation chromatography), uses tetrahydrofuran as an elution solvent, detects a differential refractometer at a flow rate of 1.0 ml / min, and a column temperature of 40 ° C. The molecular weight was converted by standard polystyrene.
The device
1) Body: "HLC-8120" manufactured by TOSOH
2) Analysis column: manufactured by TOSOH, “G1000HXL”, “G2000HXL”, “G3000HXL”,
It was used.

(6) Methylol group, methyl ether group, methylene group, dimethylene ether group ratio:
The liquid phenol resins obtained in Examples and Comparative Examples were measured by H ¹ -NMR using resins acetylated by the following method.

(6.1) Acetylation Liquid phenolic resin was placed in an eggplant-shaped flask, immersed in cold ethanol and freeze-dried under reduced pressure to remove moisture and methanol. 1 g of the lyophilized resin was placed in a 20 ml Erlenmeyer flask, the Erlenmeyer flask was immersed in ice water, 10 g of pyridine was added thereto to dissolve the resin, and then 10 g of acetic anhydride was added.
Subsequently, the Erlenmeyer flask was allowed to stand at 5 ° C. for 24 hours so that it was not exposed to light, and then the contents of the Erlenmeyer flask were placed in 200 ml of pure water. The precipitate was taken out using filter paper, and the precipitate was thoroughly washed with pure water on the filter paper. The precipitate was dissolved in acetone, placed in an eggplant-shaped flask, immersed in cold ethanol, freeze-dried under reduced pressure, the solvent and water were removed, and the resin was acetylated.

(6.2) H ¹ -NMR measurement The acetylated resin was measured in a heavy acetone solvent using tetramethylsilane (TMS) as a standard peak of 0 ppm. The device
Body: JEOL Ltd. “JNM-AL300”
It was used.

(6.3) Methylolization rate of methylol group, methyl ether group, methylene group, dimethylene ether group Calculated from the integrated value of each peak by H ¹ -NMR measurement. The calculation method is as follows. A: Peak integrated value of benzene ring near 6.7 to 7.5 ppm B: Peak integrated value of methylol group near 5 ppm C: Peak integrated value of ether group near 4.5 ppm D: 4 ppm Peak integration value of methylene group in the vicinity E: Peak integration value of methyl group in the vicinity of 3.3 ppm From the above integration value Phenol molar index: α = (A + B / 2 + C / 2 + E) / 5
Number of moles of methylol group to phenol: β = B / 2α
Number of moles of methylene group to phenol: γ = D / 2α
Number of moles of methyl ether group to phenol: δ = (D / 3) / 2α
Number of moles of dimethylene ether group to phenol: ε = (C-2 (D / 3)) / 4α
Number of moles of all bonds to phenol (formaldehyde / phenol reaction molar ratio): ζ = α + β + γ + δ + ε
And the ratio of each linking group was calculated according to the following formula.
Methylol group ratio (mol%): a = β / ζ
Methylene group ratio (mol%): b = γ / ζ
Methyl ether group ratio (mol%): c = δ / ζ
Proportion of dimethylene ether (mol%): d = ε / ζ

(7) Change in viscosity over time A liquid phenolic resin was placed in a 100 cc glass container and sealed, and this was placed in a constant temperature bath at 40 ° C., and the viscosity was measured every 2 weeks up to 8 weeks.

<Examples 1-12>
The alkyl etherified phenol resin and the acidic compound were blended according to the blending table of Table 2, and immediately mixed with a hand homomixer at room temperature for 1 minute to obtain a phenol resin composition. Table 2 shows the gelation time and pot life of each phenol resin composition.

<Examples 13 to 18>
The alkyl etherified phenol resin and the acidic compound were blended according to the blending table of Table 3, and immediately mixed with a hand homomixer at room temperature for 1 minute to obtain a phenol resin composition. Table 3 shows the gelation time and pot life of each phenol resin composition. In addition, Table 3 shows the acidic substance release temperature of each acidic compound.

<Comparative Examples 1-12>
A phenol resin and an acidic compound were blended according to the blending table of Table 4, and immediately mixed with a hand homomixer at room temperature for 1 minute to obtain a phenol resin composition. Table 4 shows the gelation time, pot life, and acidic substance release temperature of each acidic compound for each phenol resin composition.

(8) Gelation time Based on JIS K6909, it measured on a 150 degreeC hot platen using about 2 ml of liquid phenolic resins.

(9) Pot life The viscosity was measured immediately after the addition of the curing agent and when the mixture was allowed to stand at 30 ° C. for 2 hours, and was calculated according to the following calculation.
Viscosity when left for 2 hours at X = 30 ° C./Viscosity immediately after mixing with curing agent When X is a value close to 1, there is no change in viscosity, the pot life is long and good, and when X is large, the pot life is short It is judged to be bad. In addition, when the sample left to stand at 30 ° C. for 2 hours was gelled, measurement was impossible, but the pot life was also poor, and gelation was assumed.

(10) Acid release temperature About the compound which discharge | releases the acidic substance mix | blended in Examples 13-18 and Comparative Examples 6-12, the temperature which releases acid by thermal decomposition was calculated | required by TG-DTA measurement.
[Measurement condition]
Equipment: Seiko Instruments TG / DTA220
Temperature range: 30 ° C to 300 ° C (partially stopped)
Temperature increase rate: 10 ° C / min
Atmospheric gas: Nitrogen Sample weight: Approximately 20 mg

Each of the present inventions of Examples 1 to 18 is a two-pack type phenol resin composition of the present invention in which an alkyl etherified phenol resin and an acidic compound are mixed and used as a curing agent. As is clear from Table 1, the change in viscosity during storage at 40 ° C. in the resin before the addition of the curing agent was low, and the stability over time was excellent. Further, as is apparent from Tables 2 and 3, after adding the curing agent at the time of use, the pot life was long and excellent because the change in viscosity was small. In particular, the inventions of Examples 13 to 18 had an even better pot life because the acidic compound released an acidic substance during heat curing.
On the other hand, in Comparative Examples 1-12 which did not use an alkyl etherified phenol resin, the viscosity change at the time of 40 degreeC storage with the resin before adding a hardening | curing agent was large, and it was a result with bad storage stability. Moreover, after adding the curing agent, the viscosity change was large and the pot life was short.

Claims (10)

A two-pack type phenol resin composition comprising an alkyl etherified phenol resin (a) having a methyl ether group and a methylol group bonded to a phenol ring, and an acidic compound (b) as a curing agent. . The two-pack type according to claim 1, wherein the alkyl etherified phenol resin (a) has a methyl etherification rate of the methyl ether group of 50 mol% or more based on the total of the methyl ether group and the methylol group. Phenolic resin composition. The two-component phenol resin composition according to claim 1 or 2, wherein the alkyl etherified phenol resin (a) has a weight average molecular weight of 100 to 20,000. The two-component phenolic resin composition according to any one of claims 1 to 3, wherein the acidic compound (b) contains an inorganic acid and / or an organic acid. The dissociation multiplier pKa of the acidic compound (b) is 2 or less. The two-component phenol resin composition according to any one of claims 1 to 4. The two-component phenol resin composition according to any one of claims 1 to 5, wherein the acidic compound (b) contains succinic acid and / or p-toluenesulfonic acid. The two-component phenol resin composition according to any one of claims 1 to 6, wherein the acidic compound (b) releases an acidic substance having a dissociation constant pKa of 2 or less. The two-component phenol resin composition according to any one of claims 1 to 7, wherein a thermal decomposition temperature at which the acidic compound (b) releases an acidic substance having a dissociation constant pKa of 2 or less is 120 to 150 ° C. . The two-component phenol resin composition according to any one of claims 1 to 8, wherein the acidic compound (b) contains cyclohexyl aromatic sulfonates. The two-component phenolic resin composition according to any one of claims 1 to 9, wherein the acidic compound (b) contains cyclohexyl benzenesulfonate.