JPS6132331B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel cyclopentenylphenol polymer. More specifically, unlike novolak-type alkylphenol resins obtained from alkylphenols and formalin, which have been conventionally known as curing agents for epoxy resins or reinforcing materials for rubber, they have superior mechanical properties compared to those resins in the above-mentioned applications. In addition, it has good adhesion to glass when cured with hexamethylenetetramine.
This invention relates to a novel cyclopentenylphenol polymer useful as a resin for laminates. Several polymers or alkylation products derived from alkenylphenols have been proposed in the past. For example, in Organic Synthetic Chemistry Vol. 34, page 1000 (1976), a polymer of isopropenylphenol is reported. However, the polymer of isopropenylphenol is a polymer produced by a reaction between isopropenyl groups as shown in formula [A],
A polymer in which the isopropenyl group is alkylated to the other phenol nucleus is not produced. Furthermore, in JP-A-55-145626, an alkylation reaction of allyl alkylphenol is described, but as shown in formula [B], it is an alkylation reaction with phenol, and it is a polymer having repeating units. I haven't gotten it. (In the formula, m is 1 or 2) Furthermore, British Patent No. 741446 (1955)
In addition to p-cyclopentenylphenol or o-cyclopentenylphenol being synthesized by 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 formula []. The present invention provides a polymer different from these conventional alkenylphenol-derived polymers or alkylated products, and also provides a polymer that is different from the conventional alkenylphenol-derived polymers or alkylation products, and also provides a polymer that is different from the conventional alkenylphenol-derived polymers or alkylation products. However, it also provides a polymer with a higher degree of polymerization. That is, the present invention provides general formula [] (However, in the formula, R is hydrogen or an alkyl group having 1 to 5 carbon atoms, and the cyclopentane ring is bonded to the phenol nucleus at the o-position or p-position with respect to the OH group, and the cyclopentane ring The bond has a repeating unit represented by
-20,000 cyclopentenylphenol polymer. The repeating unit represented by general formula [I] includes:
General formula [] (However, R is the same as the general formula [], and OH
The repeating unit and general formula are bonded to the group at the m-position or p-position, and the bonds of the cyclopentane ring are at the 1-position and 2-position or the 1-position and 3-position) [] (However, R is the same as the general formula [], and OH
It is bonded to the group at the o-position or m-position where the cyclopentane ring is not bonded, and the bonds of the cyclopentane ring are at the 1-position and 2-position or the 1-position and 3-position. ) including repeating units represented by The weight average molecular weight of the polymer according to the present invention is 320~
20000 (standard polystyrene equivalent) is practical. The novel cyclopentenylphenol polymer according to the present invention can be obtained by subjecting a cyclopentenylphenol compound to a heating reaction in the presence of an acidic catalyst. Cyclopentenylphenol compounds have the general formula [] (However, in the formula, R is the same as in the general formula [], and the cyclopentenyl group has an o-
or p-position, and R is bonded to any other position). Compounds included in the general formula [] include p-
(2-cyclopentenyl)phenol, o-(2-
cyclopentenyl) phenols and monoalkyl substituents of these phenol groups. Examples of monoalkyl substituents include those having bond positions and alkyl groups 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. As acidic catalysts used in the reaction of cyclopentenylphenol compounds, mineral acids such as sulfuric acid, phosphoric acid, nitric acid, and hydrochloric acid, para-toluenesulfonic acid, and boron trifluoride are used. The amount of these catalysts varies depending on the type of catalyst used, but from 0.05 to
5% by weight, preferably 0.1-2.0% by weight. When the amount of catalyst is less than 0.05% by weight, the reaction is slow, monomer remains, and the molecular weight of the product is low, which is not preferred. If the amount exceeds 5% by weight, the acidic catalyst used will be neutralized with an alkaline substance after the reaction is completed, but the amount of neutralized salt generated will increase. The reaction temperature varies depending on the type of catalyst used, but is 0°C to 200°C, preferably 50°C to 170°C. If the reaction temperature is less than 0℃, the reaction will be slow, and if the reaction temperature is less than 200℃
When the amount exceeds 100%, dealkylation reactions of cyclopentenyl groups and alkyl groups tend to occur. In the reaction, a solvent does not need to be used if the reaction is carried out at a temperature higher than the temperature at which the cyclopentenylphenol compound melts (62°C), but when used, aromatic solvents such as benzene, toluene, and xylene, chloroform, Examples include chlorine-containing solvents such as carbon tetrachloride and chlorobenzene, and solvents such as ethyl ether. 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, the produced cyclopentenylphenol polymer is dissolved in a solvent such as acetone, tetrahydrofuran, methanol, or dioxane, and a base such as sodium hydroxide, potassium hydroxide, or sodium carbonate is added to this. Neutralize by adding a chemical compound. 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 desoluting, unreacted monomers are distilled off under reduced pressure, or after the above neutralization, by adding a poor solvent such as n-hexane, only the cyclopentenylphenol polymer is left in the lower part of the container. Precipitate and collect. Next, a synthesis example of a cyclopentenylphenol compound will be shown. Synthesis example 1 (synthesis of b-cyclopentenylphenol) 1 equipped with a dropping funnel, thermometer and stirrer
300g of toluene and phenol in a three-necked flask
Prepare 188g (2.0mol). Further as a catalyst 85
% phosphoric acid was added thereto, and the mixture was heated to 30°C and stirred. In this state, 99g of cyclopentanediene was 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 put into a distiller equipped with a Claisen type fractionating tube to remove toluene and unreacted phenol, and then a 1 mmHg fraction of 90°C to 115°C was obtained. As a result of gas chromatography, o-(2-cyclopentenylphenol) was detected in this product.
It was a mixture of 15.5% p-(2-cyclopentenyl)phenol and 84.5% p-(2-cyclopentenyl)phenol. This sample will be used as raw material [A]. Synthesis Example 2 (Synthesis of p-(2-cyclopentenyl)phenol) 100 g of cyclopentenyl phenol, the raw material [A] obtained in Raw Material Synthesis Example 1, was added to 100 g of n-hexane.
After cooling, 60 g of crystalline p-(2-cyclopentenyl)phenol was obtained. The obtained p
-(2-Cyclopentenyl)phenol has a melting point of
It was colorless acicular crystals with a temperature of 60-62°C. This sample will be used as raw material [B]. Synthesis Example 3 (Synthesis of 2-methyl-4-cyclopentenylphenol) 500 with a dropping funnel, thermometer and stirrer installed
150 g of toluene and 93.1 g (0.861 mol) of o-cresol were added to a three-neck flask, and 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, add 62 g (0.94 mol) of cyclopentadiene from the dropping funnel.
was gradually dripped for 30 minutes. Reaction temperature 24℃～
The reaction was further stirred at 27°C for 8 hours. After the reaction, the reaction solution was transferred to a separatory funnel to remove the phosphoric acid that had accumulated in the lower layer, and then neutralized in the separatory funnel by adding a 20% aqueous sodium carbonate solution. 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 is liquid at room temperature, and NMR,
From the results of elemental analysis, it was confirmed that it was 2-methyl-4-cyclopentenylphenol. Next, examples of the present invention will be shown. Example 1 50 g of p-(2-cyclopentenyl)phenol, the raw material [B] 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, and para-toluenesulfone was added. Add 0.5g of acid,
Heating and stirring was continued for 2 hours and 30 minutes. After the reaction is complete, the contents are transferred to a stainless steel plate and cooled to solidify. Grind the solid 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, after which the neutralized salt and excess sodium carbonate were removed. Remove acetone from the neutralized acetone solution using a rotary evaporator, and obtain 45 g of black solid cyclopentenylphenol polymer [B].
Obtained. The softening point of this cyclopentenylphenol polymer [B] was 75°C. Additionally, this eliminates the limit of 5000 columns (column agent
GELKO A-120, Hitachi Chemical Co., Ltd. product name) 4
They were connected in series and analyzed by high performance liquid chromatography using tetrahydrofuran as an eluent, and the weight average molecular weight was determined using a standard polystyrene calibration curve, and the weight average molecular weight was 770. Next, FIG. 1 shows the results of nuclear magnetic resonance analysis of the cyclopentenylphenol polymer [B]. 1 in Figure 1 is the analysis result of p-(2-cyclopentenyl)phenol of raw material [B], and 2 in Figure 1 is the analysis result of p-(2-cyclopentenyl)phenol.
is the analysis result of cyclopentenylphenol polymer [B]. The peak at the δ value of 5.7 ppm in 1 in Figure 1 is the double bond proton of the cyclopentenyl group of p-(2-cyclopentenyl)phenol, but this peak disappears in the cyclopentenylphenol polymer [B]. It can be seen that it is used for polymerization. Also, there is a peak of the benzene ring proton at a position centered on the δ value of 6.8 ppm, but in the case of p-(2-cyclopentenyl) phenol, there are four symmetrical peaks, whereas cyclopentenyl phenol In system polymer [B], symmetry is lost and there is one broad peak, so it is a di-substituted phenol. Furthermore, the amount of benzene ring protons and the amount of alkyl group protons are as shown in Table 2,
This indicates that the polymer was obtained not through polymerization due to the reaction between double bonds, but through an alkylation addition reaction of the cyclopentenyl group to the phenol nucleus.

[Table] Example 2 p-(2-cyclopentenyl)phenol and o-(2-cyclopentenyl) obtained in Synthesis Example 1
50 g of raw material [A], which is a mixture with phenol, 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 desolubization were carried out in the same manner as in Example 1 to obtain 46 g of cyclopentenylphenol polymer [A]. The softening point of the cyclopentenylphenol polymer [A] was 85°C. In addition, a column with an exclusion limit of 5000 (column agent: GELKO A120, Hitachi Chemical
Co., Ltd. (trade name) was connected in series and analyzed by high performance liquid chromatography using tetrahydrofuran as the eluent, and the weight average molecular weight was determined using a standard polystyrene calibration curve.The molecular weight was 5000.
Weight average molecular weight 1100 with some molecules exceeding
It was a polymer of From this, o-(2-cyclopentenyl)
It can be seen that a polymer similar to the cyclopentenylphenol polymer [B] was produced even if phenol was present. Next, FIG. 2 shows the results of nuclear magnetic resonance analysis of the cyclopentenylphenol polymer [A]. 3 in FIG. 2 is the analysis result of the raw material [A], and 4 in FIG. 2 is the analysis result of the cyclopentenylphenol polymer [A]. 3 in Figure 2 is the δ value
The peak at 5.8 ppm is the double bond proton of the cyclopentenyl group, but this disappeared in the cyclopentenylphenol polymer [A], indicating that it was used in the polymerization. Example 3 40 g of 2-methyl-4-cyclopentenylphenol obtained in Synthesis Example 3 was added to a thermometer and a stirrer.
Pour into a 100ml three-necked flask, add 0.4g of para-toluenesulfonic acid, and react at 150°C for 5 hours.
After the reaction, neutralization and dissolution were carried out in the same manner as in Example 1 to obtain 34 g of cyclopentenylphenol polymer [C]. The softening point of this cyclopentenylphenol polymer [C] was 72°C. In addition, Example 2
When analyzed by high performance liquid chromatography in the same manner as above, it was found to be a polymer with a weight average molecular weight of 850. FIG. 3 shows the results of nuclear magnetic resonance analysis of this cyclopentenylphenol polymer [C]. 5 in FIG. 3 is the result for the raw material 2-methyl-4-cyclopentenylphenol, and 6 in FIG. 3 is the result for the cyclopentenylphenol polymer [C]. The double bond proton of the cyclopentenyl group in 5 in Figure 3 with a δ value of 5.7 ppm disappeared in 6 in Figure 3, indicating that 2-methyl-4-cyclopentenylphenol was similarly polymerized. . The present invention provides a novel cyclopentenylphenol polymer, which can be used as an epoxy resin curing agent, a reinforcing agent for rubber, a resin with excellent adhesion between hexamethylenetetramine and glass to be cured, etc. Useful. Application examples are shown below, where "part" indicates a polymerization part. Application example (tire rubber reinforcing material) Natural rubber obtained by masticating 10 parts of the cyclopentenylphenol polymer [A] obtained in Example 2
100 parts, carbon black 50 parts, zinc oxide 5 parts,
70 with 2 parts stearic acid and 5 parts spindle oil
The mixture was mixed with a roll for 5 minutes at 70°C, and further 2.5 parts of sulfur, 1 part of a thiazole vulcanization accelerator, and 1 part of hexamethylene diamine were added and kneaded with a roll for 10 minutes at 70°C 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 50 parts of phenol, 20 parts of 80% paraformaldehyde and 25 parts of toluene were placed in a flask, and 0.1 part of paratoluenesulfonic acid was added as a catalyst.
After reacting for 3 hours at ℃ and 2 hours at 100℃,
Neutralize the catalyst with an aqueous NaOH solution, remove the neutralized salt, and remove toluene using an evaporator.
A phenolic novolak resin was obtained. The weight average molecular weight of this resin was 920 (standard polystyrene equivalent). 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 30% by weight of meta-cresol and 70% by weight of para-cresol in place of 50 parts of phenol in Comparative Application Example 1
A yellow cresol novolak resin with a softening point of 80° C. was obtained by carrying out the reaction in exactly the same manner as in Comparative Application Example 1, except that 85 parts of mixed cresol consisting of the following were used. The weight average molecular weight of this resin was 870 (standard polystyrene equivalent). 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 also shows the results.

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

[Brief explanation of the drawing]

Figure 1 shows the nuclear magnetic resonance spectrum of p-(2-cyclopentenyl)phenol and its polymer;
The figure shows a nuclear magnetic resonance spectrum of a mixture of p-(2-cyclopentenyl)phenol and o-(2-cyclopentenyl)phenol and a copolymer of the mixture, and Figure 3 shows 2-methyl-4-cyclopentenylphenol. and the nuclear magnetic resonance spectra of its polymer. Explanation of symbols, 1...Nuclear magnetic resonance spectrum of p-(2-cyclopentenyl)phenol, 2...
Nuclear magnetic resonance spectrum of p-(2-cyclopentenyl)phenol polymer, 3...Nuclear magnetic resonance spectrum of mixture of p-(2-cyclopentenyl)phenol and o-(2-cyclopentenyl)phenol, 4... nuclear magnetic resonance spectrum of a polymer of a mixture of p-(2-cyclopentenyl)phenol and o-(2-cyclopentenyl)phenol;
5... Nuclear magnetic resonance spectrum of 2-methyl-4-cyclopentenylphenol, 6... Nuclear magnetic resonance spectrum of 2-methyl-4-cyclopentenylphenol polymer.

Claims (1)

[Claims] 1. General formula [] (However, in the formula, R is hydrogen or an alkyl group having 1 to 5 carbon atoms, and the cyclopentane ring is bonded to the phenol nucleus at the o-position or p-position with respect to the OH group, and the cyclopentane ring The bond has a repeating unit represented by
~20000 cyclopentenylphenol polymer.