JP2002212250A - Cashew oil modified phenol resin and its production process and use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cashew oil modified phenol resin having a softening point in spite of its high molecular weight, to provide its production process and a rubber composition containing the cashew oil modified phenol resin. SOLUTION: The cashew-oil-modified phenol resin has a wt. average mol.wt. of 20,000-100,000 and a softening point of 80-115 deg.C and is produced by a process comprising (I) the step of reacting a phenol with an aldehyde to give a phenol resin and (II) the step of reacting the phenol resin with a cashew oil to modify the phenol resin. In the step (II), the phenol resin and the cashew oil are reacted at a temperature lower than 180 deg.C and then the aging reaction is conducted at 190-230 deg.C. The rubber composition contains the cashew-oil-modified phenol resin and a rubber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a cashew oil-modified phenol resin suitable as a rubber composition. More specifically, the present invention relates to a cashew oil-modified phenol resin having a high molecular weight and a constant softening temperature, a method for producing the same, and a rubber composition using the cashew oil-modified phenol resin.

[0002]

2. Description of the Related Art Cashew oil-modified phenolic resins have been conventionally used for rubber additives and the like. For example, when the obtained rubber composition is used for tires, the dynamic viscosity after vulcanization is increased. Improvements in performance such as elasticity and tensile strength are required. In order to improve these performances, it is effective to use a modified phenolic resin having a high molecular weight as an additive. Not only for use as a rubber additive, but also in various fields, cashew oil-modified phenol having a higher molecular weight is used. There is a need for resins. However, in general, a cashew oil-modified phenolic resin having a high molecular weight tends to have a high softening temperature at the same time, and as described above, when the obtained rubber composition is used for a tire, the workability before vulcanization is increased. This will cause problems such as damage.

[0003]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a cashew oil-modified phenol resin which maintains a constant softening temperature despite its high molecular weight, a method for producing the same, and a cashew oil-modified phenol resin. An object of the present invention is to provide a rubber composition using a phenol resin.

[0004]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that the above problems can be solved by performing an aging reaction in a specific temperature range higher than the conventional reaction temperature in the cashew oil denaturation step. Heading, and led to the present invention. The cashew oil-modified phenolic resin of the present invention is a phenolic resin modified with cashew oil, having a weight average molecular weight of 20,000 to 100,000 and a softening temperature of 80 to 115 ° C. Features. The method for producing a cashew oil-modified phenolic resin of the present invention comprises the step (I) of reacting a phenol with an aldehyde to obtain a phenolic resin, and modifying the phenolic resin by reacting the phenolic resin with cashew oil. A method for producing a cashew oil-modified phenol resin comprising a step (II), wherein in the step (II), the phenol resin and the cashew oil are reacted at a temperature of less than 180 ° C, and then further reacted at 190 to 230 ° C. It is characterized by performing an aging reaction.

[0005] The rubber composition of the present invention comprises the cashew oil-modified phenolic resin of the present invention and a rubber.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The cashew oil-modified phenolic resin of the present invention comprises a step (I) of reacting a phenol with an aldehyde to obtain a phenol resin; And a step (II) of modifying the resin. The phenols used as a raw material in the step (I) are not particularly limited, and include, for example, phenol or nucleus-substituted phenol. Examples of the nucleus-substituted phenol include cresol,
Xylenol, ethylphenol, propylphenol, n-butylphenol, isobutylphenol, t
-Butylphenol, n-amylphenol, isoamylphenol, n-hexylphenol, isohexylphenol, n-octylphenol, t-octylphenol, nonylphenol, n-decylphenol,
Examples include isodecylphenol, n-undecylphenol, isoundecylphenol, and nucleus-substituted phenols obtained by reacting phenol with a compound having an aliphatic unsaturated group in the presence of an acid catalyst. In addition, as phenols, one or more of these can be used.

The aldehyde used as a raw material in the step (I) is not particularly limited, but includes aldehydes such as formalin, acetaldehyde, paraformaldehyde, and benzaldehyde in an aqueous formaldehyde solution. Two or more can be used, but formalin is practical.
In the step (I), the phenols and the aldehydes are mixed with phenols: aldehydes = 1: 0.3.
It is preferable to use them in a ratio of 0 to 1: 0.75 (molar ratio). When the amount of phenols is larger than the above range, only low molecular weight products tend to be obtained. On the other hand, when the amount of phenols is smaller than the above range, gelation may occur, which is not preferable.

In the step (I), for example, a catalyst conventionally used in the reaction, such as paratoluenesulfonic acid, sulfuric acid, oxalic acid, phenolsulfonic acid, etc., can be used. The amount of the catalyst used is not particularly limited, but is usually 0.0
The range of 5 to 10% by weight is preferable. Step (I)
The reaction conditions and the reaction method in are not particularly limited. For example, the reaction temperature is usually 50 to 150.
° C, preferably 80 to 120 ° C, and the reaction time is usually 1 to 30 hours, preferably 2 to 20 hours. Further, the reaction is performed at 67 to 800 hPa
It may be carried out under a reduced pressure.

The cashew oil used as a raw material in the step (II) is a cashew nut shell oil, and those conventionally used industrially can be used. In the step (II), the phenol resin and the cashew oil obtained in the step (I) are mixed with phenol resin: cashew oil = 1: 0.3 to 1: 0.8.
(Weight ratio). If the amount of cashew oil is less than the above range, gelation may occur. On the other hand, if the amount of cashew oil is more than the above range, the molecular weight tends not to increase sufficiently, which is not preferable.

In the step (II), the method of reacting cashew oil with the phenolic resin is as follows.
There is no particular limitation except that the reaction is performed at a temperature lower than ℃,
A known method may be adopted. If the reaction temperature is raised to 180 ° C. or higher immediately after the introduction of cashew oil, the reaction may occur rapidly and gel may occur. Preferably, 140 to 180
The reaction is preferably performed at a temperature of 3 to 20 hours under reduced pressure of about 67 to 800 hPa or at normal pressure. In the step (II), for example, a catalyst conventionally used in the reaction, such as paratoluenesulfonic acid, sulfuric acid, oxalic acid, and phenolsulfonic acid, can be used. The amount of the catalyst used is not particularly limited, but is usually preferably in the range of 0.05 to 10% by weight based on the phenol. Usually, the catalyst used in the step (I) remains in the phenol resin, and the phenol resin obtained continuously without removing the remaining catalyst is often subjected to the step (II). The reaction of the step (II) can be advanced by the action of the remaining catalyst used in the step (I) without using a new catalyst in the step II).

In the present invention, it is important that in the step (II), after the phenol resin is reacted with cashew oil, an aging reaction is further performed at 190 to 230 ° C. By carrying out the aging reaction in a specific temperature range in this way, it is possible to increase the molecular weight while maintaining a constant softening temperature. If the temperature at the time of the aging reaction is lower than 190 ° C., a large amount of time is required to increase the molecular weight, while if it exceeds 230 ° C., the molecular weight may increase rapidly and gel may occur. Further, the time of the aging reaction may be appropriately set according to the desired molecular weight, and is not particularly limited, but is preferably, for example, about 2 to 30 hours.

In the present invention, the cashew oil-modified phenolic resin obtained from the step (I) and the step (II) may be further tableted. The tableting step can be performed by a conventionally known method, and is not particularly limited. For example, the cashew oil-modified phenolic resin obtained from the step (I) and the step (II) may be melted at 150 to 200 ° C. and granulated by a funnel or the like. The cashew oil-modified phenolic resin of the present invention obtained as described above has a weight average molecular weight of 20,000 to 100,000 and a softening temperature of 80 to 115 ° C. Weight average molecular weight of 20,
When it is less than 000, for example, when used as a rubber composition for tires, the performance such as dynamic viscoelasticity and tensile strength after vulcanization becomes insufficient. When it exceeds 100,000, the unvulcanized rubber sheet becomes It becomes hard and causes a problem in workability before vulcanization. When the softening temperature is lower than 80 ° C., blocking tends to occur during storage and transportation of the resin, and
If the temperature exceeds 15 ° C., the unvulcanized rubber sheet becomes hard, which causes a problem in workability before vulcanization. The cashew oil-modified phenolic resin of the present invention may be obtained by a method other than the above-described production method, and the production method is not particularly limited.

The rubber composition of the present invention comprises the cashew oil-modified phenolic resin of the present invention and a rubber. The rubber is not particularly limited, and examples thereof include known rubbers such as natural rubber, diene rubber, diene copolymer rubber, halogenated butyl rubber, and blends thereof. In the rubber composition of the present invention, the mixing ratio of the cashew oil-modified phenol resin and the rubber is not particularly limited, but is preferably, for example, 2 to 40 parts by weight based on 100 parts by weight of the rubber.

In the rubber composition of the present invention, if necessary,
For example, zinc oxide, carbon black, stearic acid,
Conventionally known additives such as sulfur and a vulcanization accelerator can be contained. The amounts of these additives are not particularly limited, and may be set as appropriate. The rubber composition of the present invention has excellent performance such as dynamic viscoelasticity and tensile strength after vulcanization, and also has good workability before vulcanization, so that it can be suitably used as a tire.

[0015]

The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. The weight average molecular weight was measured by GPC, and the softening temperature was measured by a ball and ring method. (Example 1) Phenol 940 g (10 mol) and 37%
527.0 g of formalin (6.5 mol of formaldehyde) were placed in a flask equipped with a reflux condenser, and heated to 50 ° C. Next, 9.6 g of phenolsulfonic acid was added,
After reacting at 100 ° C. for 6 hours, the mixture was heated and concentrated under reduced pressure of 200 hPa until the temperature reached 140 ° C. After concentration, 564 g of cashew oil was added, and the temperature was raised to 180 ° C. while reducing the pressure at 107 hPa. Then, at 230 ° C., 2
After aging for 0 hours, the weight average molecular weight was 60,00.
0, a cashew oil-modified phenol resin having a softening temperature of 101 ° C. was obtained.

(Example 2) In Example 1, 37% formalin 28 was used instead of 527.0 g of 37% formalin.
The same method was used except that 3.8 g (3.5 mol of formaldehyde) was used and 329 g of cashew oil was used instead of 564 g of cashew oil, and the weight average molecular weight was 25.0.
A cashew oil-modified phenol resin having a softening temperature of 85 ° C. was obtained. (Example 3) In Example 1, 37% formalin 52 was used.
Instead of 7.0 g, 405.4 g of 37% formalin (5.0 mol of formaldehyde) was used, and cashew oil 56
A cashew oil-modified phenol resin having a weight average molecular weight of 40,000 and a softening temperature of 92 ° C. was obtained using the same method except that 470 g of cashew oil was used instead of 4 g.

Example 4 940 g (10 mol) of phenol and 567.6 g (7.0 mol of formaldehyde) of 37% formalin were placed in a flask equipped with a reflux condenser, and 50%
Heated to ° C. Next, 4.7 g of oxalic acid was added, and 100
After reacting at 6 ° C. for 6 hours, the mixture was heated and concentrated under reduced pressure of 200 hPa until the temperature reached 140 ° C. After concentration, 10 g of 98% sulfuric acid and 423 g of cashew oil were added, and 107 hPa
The temperature was raised to 180 ° C. while reducing the pressure. Thereafter, the mixture was further subjected to an aging reaction at 220 ° C. for 12 hours to obtain a cashew oil-modified phenol resin having a weight average molecular weight of 35,000 and a softening temperature of 105 ° C.

(Example 5) In Example 4, 37% formalin 32 was used instead of 567.6 g of 37% formalin.
The same method was used except that 4.3 g (4.0 mol of formaldehyde) was used, 376 g of cashew oil was used instead of 423 g of cashew oil, and the aging reaction time was changed from 12 hours to 25 hours. Is 55,000,
A cashew oil-modified phenol resin having a softening temperature of 81 ° C. was obtained. (Example 6) In Example 4, 37% formalin 56
Instead of 7.6 g, use 486.5 g of 37% formalin (6.0 mol of formaldehyde), and use cashew oil 42
The same method was used except that 564 g of cashew oil was used instead of 3 g, and the aging reaction time was changed from 12 hours to 25 hours, and the weight average molecular weight was 70,000 and the softening temperature was 9
A cashew oil-modified phenol resin at 3 ° C. was obtained.

(Comparative Example 1) The procedure of Example 1 was repeated, except that the aging reaction was not carried out. The obtained cashew oil-modified phenol resin had a weight average molecular weight of 7,000 and a softening temperature of 95 ° C. there were. (Comparative Example 2) The same procedure as in Example 3 was carried out except that the aging reaction was not carried out. The obtained cashew oil-modified phenol resin had a weight average molecular weight of 4,000 and a softening temperature of 86 ° C.

(Comparative Example 3) The procedure of Example 4 was repeated, except that the aging reaction was not performed. The obtained cashew oil-modified phenol resin had a weight average molecular weight of 8,500 and a softening temperature of 98 ° C. there were. (Comparative Example 4) When the same procedure as in Example 6 was carried out except that the aging reaction was not carried out, the obtained cashew oil-modified phenol resin had a weight average molecular weight of 5,000 and a softening temperature of 86 ° C.

Comparative Example 5 The same method was used as in Comparative Example 4, except that 188 g of cashew oil was used instead of 564 g of cashew oil, and the weight average molecular weight was 33,000.
A cashew oil-modified phenol resin having a softening temperature of 126 ° C. was obtained. (Comparative Example 6) A cashew oil-modified phenol resin was obtained using the same method as in Comparative Example 1 except that 235 g of cashew oil was used instead of 564 g of cashew oil.

Next, using the cashew oil-modified phenolic resins obtained in Examples 1 to 6 and Comparative Examples 1 to 5, AS
A rubber sheet was prepared according to TM-D-3184, and the following evaluation was performed. Table 1 shows the results. (Green Strength) A 2 mm-thick unvulcanized rubber sheet was used to punch a JIS No. 2 type tensile test piece, and the tensile stress of the obtained test piece was measured according to JIS-K-6301. (Tensile strength after vulcanization) An unvulcanized rubber sheet was vulcanized at 160 ° C. for 20 minutes under a load of 100 kg / cm ² to obtain a vulcanized rubber sheet. Using this vulcanized rubber sheet, JI
An S3 type tensile test piece was punched out, and 2
A tensile test was performed at 0 ° C., and the stress at break was measured.

(Dynamic Viscoelasticity) The vulcanized rubber is 20 mm in length,
A test piece having a width of 5 mm and a thickness of 2 mm was measured for dynamic viscoelasticity under the conditions of 20 ° C., a dynamic strain of 1%, and a frequency of 10 Hz.

[0024]

[Table 1]

[0025]

The cashew oil-modified phenolic resin of the present invention has a high molecular weight and an appropriate softening temperature, and can be suitably used, for example, as a rubber composition for tires.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J002 AC011 AC021 BB241 CC072 GN01 4J033 CA01 CA02 CA03 CA05 CA11 CA12 CA37 CB03 CB18 CC03 CC08 CC09 CD04 HA02 HA04 HB01

Claims (5)

[Claims] 1. A phenol resin modified with cashew oil, having a weight average molecular weight of 20,000 to 10.
A cashew oil-modified phenolic resin having a molecular weight of 000 and a softening temperature of 80 to 115 ° C. 2. A cashew comprising a step (I) of reacting a phenol with an aldehyde to obtain a phenol resin, and a step (II) of reacting the phenol resin with a cashew oil to modify the phenol resin. A method for producing an oil-modified phenol resin, characterized in that in the step (II), the phenol resin is reacted with cashew oil at a temperature of less than 180 ° C, and then an aging reaction is further performed at 190 to 230 ° C. A method for producing a cashew oil-modified phenol resin. 3. In the step (I), a phenol and an aldehyde are converted into a phenol and an aldehyde.
Used in a ratio of 1: 0.30 to 1: 0.75 (molar ratio),
Further, in the step (II), the phenol resin and the cashew oil are mixed, and the phenol resin: cashew oil = 1:
The method for producing a cashew oil-modified phenolic resin according to claim 2, wherein the phenolic resin is used in a ratio of 0.3 to 1: 0.8 (weight ratio). 4. A rubber composition comprising the cashew oil-modified phenolic resin according to claim 1 and a rubber. 5. The rubber composition according to claim 4, which is used as a tire.