JPS6116764B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel method for producing a cyclopentenylphenol polymer. More specifically, unlike novolak-type alkylphenol resins, which are synthesized from alkylphenols and conventional formalin, which are conventionally known as curing agents for epoxy resins or reinforcing agents for rubber, they have lower mechanical properties compared to the above-mentioned resins. The present invention relates to a method for producing a novel cyclopentenylphenol polymer useful as a resin for laminates, which has excellent adhesion to glass when cured with hexamethylenetetramine. Several polymers or alkylation products derived from alkenylphenols have been proposed. For example, in Organic Synthetic Chemistry Vol. 34, page 1000 (1976), a polymer of isopropenylphenol is reported. However, a polymer of isopropenylphenol is a polymer produced by a reaction between isopropenyl groups, as shown in formula [A], and a polymer in which isopropenyl groups are alkylated to the other phenol nucleus is not produced. Furthermore, JP-A-55-145626 describes the alkylation reaction of alkylphenols, but as shown in formula [B], it is an alkylation reaction with phenol, and the polymer having repeating units is I haven't gotten it. Furthermore, British Patent No. 741446 (1955)
In addition to synthesizing p-cyclopentenylphenol or o-cyclopentenylphenol through the alkylation reaction of cyclopentadiene and phenol, the formula [C] Although a compound represented by the following has been submitted, there is no mention of a polymer having a repeating unit represented by the following general formula []. The present invention provides a method for producing a polymer different from these conventional alkenylphenol-derived polymers or alkylated products, and also provides a method for producing a polymer that is different from the conventional alkenylphenol-derived polymers or alkylation products, and also provides a method for producing a polymer that is different from the conventional alkenylphenol-derived polymers or alkylated products. In contrast,
This makes it possible to produce polymers with a higher degree of polymerization. That is, the present invention provides general formula [] (In the formula, R is hydrogen, halogen, nitro group, alkyl group or alkoxy group having 1 to 5 carbon atoms, m is 1 or 2, and n is 1,2
or 3, m+n is 4 or less, and OH
Hydrogen is bonded to at least one of the two o- and p-positions with respect to the group). The present invention relates to a method for producing a cyclopentenylphenol polymer. The cyclopentenylphenol polymer obtained by the present invention has the general formula [] (However, in the formula, R and n are the same as in the general formula [], and the cyclopentane ring is bonded to the phenol nucleus at the o-position or p-position with respect to the OH group, are 1- and 2-
or in the 1- and 3-positions). The cyclopentenylphenol compound represented by the general formula [] is the o-position or p-position of the phenol nucleus.
At least one of the - positions is hydrogen. This is because the cyclopentenyl group attached to the phenol nucleus forms an otom of another phenol nucleus through an alkylation reaction.
This is necessary because high molecular weight compounds are produced by addition at the - or p-positions. Typical cyclopentenylphenol compounds include o-cyclopentenylphenol, p-cyclopentenylphenol, 2-methyl-4-cyclopentenylphenol, 2-cyclopentenyl-4-methylphenol, 2,4 -dicyclopentenylphenol, etc., and monoalkyl substituents other than those listed here include those shown in Table 1.

[Table] In Table 1, propyl group is either n-propyl group or isopropyl group, and butyl group is n-propyl group.
It is either a butyl group, a sec-butyl group or a tert-butyl group, and a pentyl group is either an n-pentyl group or other structurally isomeric groups. In reacting these cyclopentenylphenol compounds, acidic catalysts used include mineral acids such as sulfuric acid, phosphoric acid, nitric acid, and hydrochloric acid, and paratoluenesulfonic acid, as well as Lewis acid catalysts such as boron trifluoride, aluminum chloride, and molybdenum chloride. Acid can be given. The amount of these catalysts varies depending on the type of catalyst used, but 0.05
-5% by weight is preferred, particularly 0.1-2.0% by weight. When the amount of catalyst is less than 0.05% by weight, the reaction is slow, the molecular weight of the product is small, and a large amount of raw material monomer tends to remain. However, the amount of neutralized salt generated tends to be large. The reaction temperature varies depending on the type of catalyst used and the amount of catalyst, but is preferably 0°C or more and 200°C or less,
Particularly preferred is 50°C or higher and 170°C or lower. When the reaction temperature is low, such as less than 0°C, the reaction tends to be slow, and when the reaction temperature exceeds 200°C, a reaction in which the cyclopentenyl group and other substituents are eliminated tends to occur. In the reaction, the solvent does not need to be used if the reaction is carried out at a temperature higher than the melting temperature of the cyclopentenylphenol compound, but when used, aromatic solvents such as benzene, toluene, xylene, chloroform, carbon tetrachloride, Examples include chlorine-containing solvents such as chlorobenzene, and ethyl ether. Furthermore, a phenol compound can be added to adjust the molecular weight of the cyclopentenylphenol polymer obtained in the present invention and to modify the obtained polymer. Examples of the phenol compound include phenol, alkylphenol having an alkyl group having 1 to 6 carbon atoms, bisphenol compound, etc. The amount of these compounds added is determined as appropriate depending on the molecular weight of the polymer to be obtained. However, 0 to 20 for cyclopentenylphenol compounds
Weight percent is preferred. If this value is exceeded, generally only a polymer with a small molecular weight can be obtained. The cyclopentenylphenol polymer after the reaction contains the acidic catalyst used in the reaction and unreacted monomers, so if purification is necessary, the following purification method is adopted. To remove the acidic catalyst used in the reaction, dissolve the generated cyclopentenylphenol compound in a solvent such as acetone, tetrahydrofuran, methanol, or dioxane, and add a basic solution such as sodium hydroxide, potassium hydroxide, or sodium carbonate to this. Add compound to neutralize. After neutralization, the neutralized salt is removed by filtration, and the solvent used is then distilled off. In addition, to remove unreacted monomers, neutralization and
After desolvation, unreacted monomers are distilled off under reduced pressure, or after the above neutralization, a poor solvent such as n
- By adding hexane, cyclohexane, etc., only the polymer is obtained as a precipitate at the bottom of the container. Next, a synthesis example of a cyclopentenylphenol compound will be shown. Synthesis Example 1 (Synthesis of cyclopentenylphenol) 1 equipped with a dropping funnel, thermometer, and stirrer
Charge 300 g of toluene and 188 g (2.0 mol) of phenol into a three-necked flask. Furthermore, as a catalyst
20g of 85% phosphoric acid was added, and the mixture was heated and stirred at 30°C. In this state, 99g of cyclopentadiene is added from the dropping funnel.
(1.5 mol) was added dropwise over 30 minutes. Since it was an exothermic reaction, it was added dropwise with some cooling. After the dropwise addition, stirring was continued for 8 hours at 30°C to advance the reaction. It was confirmed by gas chromatography that cyclopentadiene had disappeared through the reaction, and 15 g of sodium carbonate was added to neutralize the phosphoric acid as a catalyst. After neutralization, the neutralized salt and excess sodium carbonate were removed by filtration. The resulting neutralized reaction solution was placed in a distiller equipped with a Claisen type fractionating tube to remove toluene and unreacted phenol, and then a fraction of 90°C to 115°C was obtained at 1 mmHg. As a result of gas chromatography, this product was found to be a mixture containing 15.5% by weight of o-cyclopentenylphenol and 84.5% by weight of p-cyclopentenylphenol. Synthesis Example 2 (Synthesis of p-cyclopentenylphenol) 100 g of o-, p-mixed cyclopentenyl phenol obtained in Synthesis Example 1 was dissolved in 100 g of n-hexane, cooled, and the precipitated crystals were collected. The mixture was dried to obtain 60 g of p-cyclopentenylphenol. The obtained p-cyclopentenylphenol was colorless needle-like crystals with a melting point of 60-62°C. Synthesis Example 3 (Synthesis of 2-methyl-4-cyclopentenylphenol) A dropping funnel, thermometer, and stirrer were installed.
150 g of toluene and 93.1 g (0.861 mol) of o-cresol were added to a 500 ml three-necked flask, and further 18.6 g of 85% phosphoric acid was added as a catalyst and stirring was started. The temperature inside the reactor was 24°C. In this state,
62 g (0.94 mol) of cyclopentadiene was added dropwise from the dropping funnel over a period of 30 minutes. reaction temperature 24
The reaction was further stirred at 27°C to 27°C for 8 hours. After the reaction, transfer the reaction solution to a separating funnel and remove the phosphoric acid that had accumulated in the lower layer, then add a 20% aqueous sodium carbonate solution to neutralize it in the analytical funnel. After separating and removing the lower aqueous layer, the upper toluene layer was dehydrated with anhydrous sodium sulfate in a beaker. The resulting neutralized reaction solution was put into a distiller equipped with a Claisen type fractionating tube to remove toluene and unreacted o-cresol, and then a fraction of 138 to 141° C. was obtained at 4 mmHg. This substance was liquid at room temperature, and was confirmed to be 2-methyl-4-cyclopentenylphenol from the results of nuclear magnetic resonance (NMR) spectrum and elemental analysis. Example 1 50 g of 4-cyclopentenylphenol obtained in Synthesis Example 2 was placed in a 100 ml three-necked flask equipped with a thermometer and a stirrer, heated to 150°C, 0.5 g of para-toluenesulfonic acid was added, and the mixture was heated for 2 hours. The mixture was heated and stirred for several minutes. After the reaction is complete, transfer the contents to a stainless steel plate.
Grind the solid to be solidified by cooling and add 100g of acetone.
Further, 5 g of sodium carbonate was added and stirring was continued for 5 hours to neutralize the para-toluenesulfonic acid used as a catalyst, and the neutralized salt and excess sodium carbonate were then removed by filtration. Acetone was removed from the neutralized acetone solution under reduced pressure using a rotary evaporator to obtain 45 g of a black solid resin. The softening point of this resin was 75°C. In addition, this resin was analyzed by high-performance liquid chromatography using four columns with an exclusion limit of 5000 (column material: GELKO A-120, Hitachi Chemical Co., Ltd. product name) connected in series and using tetrahydrofuran as the eluent. , using a standard polystyrene calibration curve,
When the weight average molecular weight was determined, it was a polymer with a weight average molecular weight of 770. Furthermore, when we performed NMR analysis and compared the raw material 4-cyclopentenyl phenol and the produced resin, we found that 4-cyclopentenyl phenol had a δ value of
A double bond proton of the cyclopentene ring was present at 5.7 ppm, but it was found that this double bond proton disappeared in the resulting resin and was used for polymerization. In addition, when the amount of benzene ring protons and the amount of alkyl group protons were compared, as shown in Table 2, the double bond of the cyclopentenyl group was alkylated to the o-position of another cyclopentenyl phenol, resulting in a polymer. It was found that the following was obtained.

[Table] Example 2 50 g of mixed cyclopentenyl phenol in which the o-cyclopentenyl phenol obtained in Synthesis Example 1 and p-cyclopentenyl phenol are present at 15.5% by weight and 84.5% by weight, respectively, was added to Example 1.
The mixture was poured into the same flask, 0.5 g of para-toluenesulfonic acid was added, and the mixture was reacted at 150°C for 5 hours. After the reaction, neutralization and desolubization were carried out in the same manner as in Example 1 to obtain 46 g of a black and colored resin. The softening point of this resin was 85°C. In addition, a column with an exclusion limit of 5000 (column agent: GELKO A-120,
When two bottles of Hitachi Chemical Co., Ltd. (trade name) were connected in series and analyzed by high performance liquid chromatography using tetrahydrofuran as the eluent, the molecular weight
The polymer had a weight average molecular weight of 1100, with some molecules exceeding 5000. The results of NMR analysis of this polymer show that the raw material
A peak with a δ value of 5.8 ppm detected by NMR analysis (the peak of the double bond proton of the cyclopentenyl group)
has disappeared, indicating that it was used for polymerization. From the above, it can be seen that o-cyclopentenylphenol reacts in the same manner as p-cyclopentenylphenol to produce a polymer. Example 3 25 g of 2-methyl-4-cyclopentenylphenol obtained in Synthesis Example 3 was placed in the same flask as in Example 1, 25 g of toluene was added as a solvent, and 0.5 g of para-toluenesulfonic acid was added. The reaction was carried out at ℃ for 8 hours. After the reaction, add 10% of tetrahydrofuran to the flask.
After adding g, the liquid in the flask was put into a separating funnel, water was added, and para-toluenesulfonic acid was removed by washing with water. Thereafter, the solvents toluene and tetrahydrofuran were removed using a rotary evaporator to obtain 15 g of a black polymer. When this polymer was analyzed by high performance liquid chromatography in the same manner as in Example 2, it was found to be a polymer with a weight average molecular weight of 1300, and when nuclear magnetic resonance analysis was performed, it was found that raw material 2 had a δ value of 5.75 ppm. It was found that the double bond proton of -methyl-4-cyclopentenylphenol disappeared. This shows that cyclopentenylphenol compounds having an alkyl group also produce polymers. Example 4 A mixed phenol raw material obtained by adding 5 g of phenol to 45 g of mixed cyclopentenyl phenol containing 15.5% by weight and 84.5% by weight of o-cyclopentenylphenol and p-cyclopentenylphenol obtained in Synthesis Example 1 was carried out. The mixture was placed in the same flask as in Example 1, 0.5 g of para-toluenesulfonic acid was added, and the mixture was reacted at 150°C for 5 hours. After the reaction, neutralization and desolution were carried out in the same manner as in Example 1 to obtain 46 g of a black polymer. The softening point of this resin was 72°C, and as a result of high performance liquid chromatography analysis in the same manner as in Example 1, the weight average molecular weight was 750. From this, even if phenol is present,
It can be seen that phenol is incorporated into the polymer. Application example (tire rubber reinforcing material) 10 parts of the resin obtained in Example 2 was heated at 70°C with 100 parts of masticated natural rubber, 50 parts of carbon black, 5 parts of zinc oxide, 2 parts of stearic acid, and 5 parts of spindle oil. Mix on a roll for 5 minutes, then add sulfur.
2.5 parts of the mixture, 1 part of a thiazole vulcanization accelerator, and 1 part of hexamethylene diamine were added and kneaded with rolls at 70°C for 10 minutes to obtain a kneaded dough. This kneaded dough was press-vulcanized at 140° C., 10 kg, and 30 minutes to obtain a rubber sheet. Table 3 shows the physical properties of this rubber sheet. Comparative Application Example 1 A flask was charged with 50 parts of phenol, 20 parts of 80% paraformaldehyde, and 25 parts of toluene, and 0.1 part of paratoluenesulfonic acid was added as a catalyst.
After reacting at 80°C for 3 hours and at 100°C for 2 hours, the catalyst was neutralized with an aqueous NaOH solution, the neutralized salt was removed, and the toluene was distilled off using an evaporator. Resin was obtained. The average molecular weight of this resin was 920. This phenol novolak resin was kneaded into a dough using the same formulation as in the application example, press vulcanization was performed, and the physical properties of the rubber were measured. The results are also shown in Table 3. Comparative Application Example 2 The reaction was carried out in exactly the same manner as in Practical Application Example 1, except that 85 parts of mixed cresol of 30% metacresol and 70% para-cresol was used instead of 50 parts of phenol in Comparative Application Example 1, and the softening point was 80°C. A yellow cresol novolak resin was obtained. The average molecular weight of this resin is
It was 870. This cresol novolak resin was kneaded into a dough using the same formulation as in the application example, press vulcanized, and the physical properties of the rubber were measured. Table 3
The results are also shown here.

[Table] Table 3 shows that when a cyclopentenyl phenol polymer is used, the hardness of the rubber and the strength and elongation in the tensile test are lower than those of the phenol novolak resin and the cresol novolak resin.
shown to improve.

Claims (1)

[Claims] 1. General formula [] (In the formula, R is hydrogen, halogen, nitro group, alkyl group having 1 to 5 carbon atoms, or alkoxy group, m is 1 or 2, n is 1, 2 or 3, and m+n is 4 or less,
At least one type of cyclopentenyl phenol compound represented by hydrogen bonded to at least one of the two O-positions and P-position with respect to the OH group under an acidic catalyst. A method for producing a cyclopentenylphenol polymer, characterized by: