JPH0741535A - Phenol resin composition - Google Patents

Abstract

PURPOSE:To obtain a phenol resin compsn. excellent in moisture resistance, heat resistance, etc., by reacting a butadiene polymer with a phenol compd. in the presence of an acid catalyst and compounding the resulting high-mol.-wt. polymer with a specified amt. of a curative. CONSTITUTION:A phenol-modified butadiene polymer with a number average mol.wt. of 500-5,000 is produced by reacting a butadiene polymer (e.g. a butadiene homopolymer or a butadiene-isoprene block copolymer) with a phenol (e.g. phenol or m-cresol) in the presence of an acid catalyst (e.g. sulfuric acid). A phenol resin compsn. is prepd. by compounding 100 pts.wt. the modified butadiene polymer with 5-20 pts.wt. curative (e.g. hexamethylenetetramine or paraformaldehyde). Thus obtd. compsn., giving a cured article excellent in resistance to thermal shock, is useful for various molding materials, electric parts, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phenolic resin composition which is excellent in moisture resistance and heat resistance and is useful as a molding material, a laminate material, a paint, an adhesive, a friction material and the like.

[0002]

2. Description of the Related Art Phenolic resins are inexpensive and have excellent moldability, mechanical properties, heat resistance, electrical insulation, etc., so various molding materials, electrical parts, laminated materials, paints, adhesives, friction materials It is used for materials. A phenol novolac resin is generally used as the phenol resin, but when the phenol novolac resin is used, it has a high hygroscopic property, and therefore, there is a problem that the insulating property deteriorates when used for a long period of time. Is not suitable.
Further, since the heat resistance and the humidity resistance are insufficient, there is a problem that the mechanical strength rapidly deteriorates when kept at a temperature of 250 ° C. or higher for a long time. Further, when used as a friction material, for example, a brake material, the low molecular weight component decomposes to generate gas due to a temperature rise when the brake is used harshly, and the gas lowers the friction coefficient of the brake surface. There is a problem that the effectiveness of is reduced.

The heat resistance of the phenol novolac resin,
Recently, various resins having different structures have been proposed for the purpose of improving moisture resistance and the like. For example, Japanese Patent Publication No. 47-1511
Japanese Patent Publication No. 1 proposes a resin obtained by subjecting a phenol compound and an aralkyl compound to a condensation reaction. However, the resin is insufficient in heat resistance and has a low bending strength at a high temperature of 200 ° C. or higher, so that there is a problem in using it as a molding material used at a high temperature. In addition, JP-A-5-70
Japanese Patent No. 668 proposes a dicyclopentadiene phenol resin obtained by reacting dicyclopentadiene and a phenolic compound. However, since the dicyclopentadiene phenol resin has many low molecular weight components, there is a problem that mechanical strength, heat resistance and humidity resistance are insufficient.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and provide a phenol resin composition having excellent moisture resistance, heat resistance and thermal shock resistance after curing.

[0005]

According to the present invention, (A)
Number average molecular weight of 500 to 5000 obtained by reacting a butadiene polymer with a phenol compound in the presence of an acid catalyst.
There is provided a phenolic resin composition containing 100 parts by weight of the phenolized butadiene polymer of 5) and 5 to 20 parts by weight of the curing agent (B) as essential components.

The present invention will be described in more detail below.

The number average molecular weight of the butadiene polymer used in the present invention is preferably 300 to 4000, particularly 500 to
It is preferably 3000.

Examples of the butadiene polymer include a polymer obtained by homopolymerizing butadiene or a copolymer obtained by copolymerizing with butadiene.
Preferred examples of the other copolymerizable comonomer include conjugated diolefins such as isoprene and 1,3-pentadiene; aromatic vinyl monomers such as styrene, α-methylstyrene, vinyltoluene and vinylbenzene; and the like. The butadiene copolymer can be obtained by block-copolymerizing or random-copolymerizing these with butadiene. The mixing ratio of butadiene and other comonomer copolymerizable is butadiene 1
0.05 mol of other copolymerizable comonomer
The amount is preferably 0.8 mol, particularly preferably 0.1 to 0.7 mol.

Preferred examples of the phenol compound used in the present invention include phenols represented by the following general formula 1 and / or alkylnaphthols represented by the following general formula 2.

[0010]

[Chemical 1]

[0011]

[Chemical 2]

If m, n, p and q in the formula are 4 or more, the production is difficult.

Examples of the phenol compound include compounds obtained by combining R ¹ and R ² listed above, and examples thereof include phenol, o-cresol, m-cresol, p-cresol, o-ethylphenol, m-
Ethylphenol, p-ethylphenol, o-isopropylphenol, m-propylphenol, p-propylphenol, p-sec-butylphenol, p-
Monohydric phenols such as tert-butylphenol, p-cyclohexylphenol, p-chlorophenol, o-bromophenol, m-bromophenol, p-bromophenol; resorcin, catechol, hydroquinone, 2,2-bis (4'-hydroxy). Naphtholphenols such as phenyl) propane, 1,1′-bis (dihydroxyphenyl) methane, 1,1′-bis (dihydroxynaphthyl) methane; tetramethylbiphenol,
Preferred examples include dihydric phenols such as biphenols; trisphenols such as trishydroxyphenylmethane and mixtures thereof. Especially phenol,
O-cresol, m-cresol, 2,2-bis (4'-hydroxyphenyl) propane and the like are desirable from the viewpoint of economy and ease of production.

The phenolated butadiene polymer used in the present invention can be prepared by a method of reacting the butadiene polymer with the phenol compound in the presence of an acid catalyst.

The blending ratio of the phenolic compound to the butadiene polymer is preferably 1: 1 to 10 by weight. When the blending ratio of the phenolic compound is less than the above range, gelation occurs, and when it is more than the above range, it is not possible. It is not preferable because recovery of phenol in the reaction requires a large amount of energy and is not economical.

The acid catalyst is not particularly limited as long as it is a Friedel-Clafurt catalyst used in the alkylation reaction. For example, boron trifluoride, sulfonic acid having 1 to 12 carbon atoms, and sulfuric acid. , Heteropolyacid, activated clay, silica-alumina and the like can be preferably mentioned and can be appropriately selected according to the purpose. The amount of the acid catalyst used varies depending on the type of the catalyst used, but is preferably 0.1 to 10% by weight based on the butadiene polymer,
In particular, it is preferably 0.5 to 5% by weight.

In preparing the phenolated butadiene polymer, a solvent may be used as long as it does not inhibit the reaction. When a solvent is used, examples of the solvent include aromatic compounds such as benzene, toluene, xylene and chlorobenzene. Preferred examples include system compounds. The reaction conditions can be appropriately selected according to the purpose. For example, the reaction temperature is preferably 30 to 150 ° C, and particularly 50 to 1
It is preferably 20 ° C. The reaction time is preferably about 0.5 to 5 hours, and the amount of water in the system is 30 to 1
It is preferably 00 ppm. Further, since the reaction is an exothermic reaction, it is desirable to add the butadiene polymer sequentially or continuously to the solution of the catalyst and the phenol compound in order to prevent the temperature from rising due to the heat of reaction.

Further, it is desirable to appropriately select the type of catalyst, the amount of catalyst, the amount of water in the system, and the reaction time depending on the structure of the desired phenolated butadiene polymer. For example, a carbon obtained by adding a carbon atom of a benzene ring or a condensed ring of a phenol compound to a double bond part of a butadiene polymer.
The purpose of the present invention is to produce a resin having a structure having an ether bond in which a phenolic hydroxyl group of a phenol compound is added to a double bond portion of a butadiene polymer in a carbon bond structure and a structure in which a double bond of a butadiene polymer partially remains. In the case of, the method of using a catalyst having a relatively low acid strength, the method of reducing the amount of the catalyst, and the amount of water in the system of 150 to 300 weight pp.
It is desirable to use a method of increasing m or a method of shortening the reaction time. Further, for example, in order to produce a resin having a structure in which a phenol compound does not have an ether addition structure by reacting until the double bond of the butadiene polymer completely disappears, the water content in the system is set to 100 ppm by weight or less. It is desirable to use a method of manufacturing.

The phenolic hydroxyl group equivalent of the phenolated butadiene polymer used in the present invention is 160 to 600 g /
eq is preferable, and particularly 220 to 400 g / eq.
Is desirable. At this time, when the phenolic hydroxyl group equivalent is less than 160 g / eq, the moisture resistance is insufficient, and when the phenolic hydroxyl group equivalent exceeds 600 g / eq, the crosslinking density is low and the heat resistance is lowered, which is not preferable. The number average molecular weight is preferably 500 to 5,000, and more preferably 700 to 3,500. At this time, when the number average molecular weight is less than 500, the mechanical strength and heat resistance of the cured product are insufficient, and when the number average molecular weight exceeds 5000, the softening point of the resin is high and the melting temperature is high, resulting in moldability. Is inferior, which is not preferable. Furthermore, the softening point is 90-1
It is preferably 80 ° C.

The phenolized butadiene polymer used in the present invention has a high curing rate and is excellent in mechanical and thermal stability and moisture resistance, and moreover, compared with phenol novolac resin, aralkylphenol resin and dicyclopentadienephenol resin. Since the phenyl group is not bonded to the same carbon and the low molecular weight component is very small, it has excellent heat resistance. For example, it is preferable because it has a feature that it can be handled stably even at 300 ° C. or higher and gives a cured product having excellent heat resistance.

The curing agent used in the present invention is not particularly limited, but any curing agent used for phenol resins can be used. Generally, for example, hexamethylenetetramine, paraformaldehyde, trioxane, 1,3-dioxane, 4-methyl-
Preference is given to 1,3-dioxane and the like.

The phenol resin composition of the present invention can be prepared, for example, by a method of mixing a specific amount of a phenolized butadiene polymer and a specific amount of a curing agent. As the method of mixing the above-mentioned phenolized butadiene polymer and the curing agent, a method of mixing a general phenol resin and the curing agent can be used. For example, after preparing the phenolized butadiene polymer, the curing agent A method of mixing while pulverizing using a hammer mill or the like, a method of pulverizing a phenolized butadiene polymer using a hammer mill or the like, and then adding a curing agent and mixing using a ribbon blender or the like, phenol A preferable method is, for example, a method in which the butadiene butadiene polymer and the curing agent are heated and mixed at 90 to 180 ° C. using a kneader, roll, mixer or the like, and then pulverized.

The phenol resin composition of the present invention contains a curing agent in an amount of 5 to 20 parts by weight, preferably 8 to 17 parts by weight, based on 100 parts by weight of the phenolized butadiene polymer.
At this time, if the amount of the curing agent is less than 5 parts by weight, the curing reaction does not proceed sufficiently and the mechanical strength and heat resistance are insufficient. Can not.

Further, the phenol resin composition of the present invention comprises, in addition to the phenolized butadiene polymer and the curing agent,
Further, another phenol resin can be used together. Examples of the other phenol resin include bisphenol A
Type phenolic resin, novolac type phenolic resin, brominated novolac type phenolic resin, polyvinylphenol, brominated polyvinylphenol, tetrabromobisphenol A, limonene phenolic resin, paraxylenephenolic resin, dicyclopentadienephenolic resin, etc. The blending ratio of these phenolic resins is preferably 5 to 80 parts by weight, and particularly preferably 10 to 50 parts by weight, based on 100 parts by weight of the phenolized butadiene polymer.

The phenol resin composition of the present invention contains, for example, a filler, a pigment, a release agent, and a flame retardant in addition to the phenol resin composition, and is kneaded and molded by a hot roll at 90 to 180 ° C. After being made into powder, it can be used as a heat-resistant molded body such as an electric component or a friction material by molding at 140 to 250 ° C. by a molding method such as compression molding, transfer molding, injection molding or the like. As the filler used at this time, for example, wood powder, coconut shell powder, glass fiber, mica, silica, metal powder, carbon fiber, clay, wollastonite, calcium carbonate, barium sulfate, graphite,
Preference is given to carbon powder and the like.

The phenol resin composition of the present invention is dissolved in a solvent to form a varnish, and after impregnated into various base materials such as glass cloth, glass mat, asbestos paper, synthetic fiber mat, paper, cotton paper, etc. By removing the solvent, it can be used as a dry prepreg for a laminated material.

Further, the phenol resin composition of the present invention comprises an alcohol solvent such as ethyl alcohol; a ketone solvent such as methyl ethyl ketone; an ether solvent such as ethylene glycol monomethyl ether; an ester solvent such as ethyl acetate; an aroma such as toluene. Used as a coating resin by preparing a varnish by adding a group solvent or the like alone or by adding a mixed solvent thereof, and modifying it with tung oil, linseed oil, epoxy resin, furan resin, coumarone resin, etc. as necessary. can do.

Furthermore, the phenol resin composition of the present invention can be used as an adhesive by heating and softening it, and a heat-curing adhesive using an epoxy resin and an epoxy resin curing accelerator together. Can also be used as

On the other hand, the phenol resin composition of the present invention comprises, for example, epoxy modified or melamine modified phenolic resin, fibrous substances such as asbestos, metal fibers, ceramic fibers, glass fibers and aramid fibers, cashew dust and rubber powder. Organic substance: Barium sulfate, iron oxide, inorganic powder such as graphite, metal powder such as copper powder, iron powder, etc. are added and mixed by a mixer or the like, and usually 200-300 ° C. after compression molding at 140-250 ° C. 1-10 at the temperature of
It can be used as a heat resistant friction material by performing a heat treatment for a period of time.

[0030]

Since the phenol resin composition of the present invention has excellent moisture resistance, heat resistance and thermal shock resistance after curing, it can be used in various molding materials, electric parts, laminating materials, paints, adhesives, friction materials, etc. Is useful over a wide range of.

[0031]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

[0032]

Example 1 Stirrer, cooling internal coil, dropping funnel,
In a 3 liter separable flask equipped with a reflux condenser and a Liebig condenser, under a nitrogen atmosphere, trade name "Nisseki Polybutadiene B-700" (manufactured by Nippon Petrochemical Co., Ltd., number average molecular weight 700, 1, 2). Double bond 65%, 1,
350 g of 4 double bonds (35%), 900 g of phenol and 300 g of toluene were charged and immersed in an oil bath. The temperature of the oil bath was raised to 160 ° C. and about 240 g of toluene and water were distilled off with stirring. At this time, the water content in the raw material was changed by the Karl Fischer device (Mitsubishi Kasei Co.
50 when analyzed by the company, trade name "CA-06 type")
It was ppm. After the completion of dehydration, the internal temperature of the obtained raw material was cooled to 50 ° C., and 12.5 g of boron trifluoride-phenol complex was added dropwise over 1 hour while stirring.
At this time, the internal temperature rose due to the reaction heat due to the dropping of the catalyst, but the internal temperature was reduced to 80 ° C by cooling with the internal coil.
It was controlled so that After stirring for another 2 hours at 80 ° C., 12.5 g of calcium hydroxide was added and reacted. After the reaction was completed, 300 g of toluene was added to the reaction solution to reduce the viscosity, and the catalyst residue in the reaction solution was filtered off. The resulting filtrate was distilled and concentrated to obtain 490 g of a phenolized butadiene polymer. The phenolized butadiene polymer has a softening point of 130 ° C. and a number average molecular weight of 10
00, the hydroxyl equivalent was 317 g / eq.

Then, hexamethylenetetramine (manufactured by Kishida Chemical Co., Ltd., purity 99.5%) 12 as a curing liquid is added to 100 parts by weight of the phenolized butadiene polymer.
A part by weight was added and crushed with a hammer mill to obtain a phenol resin composition. To the resulting phenol resin composition, various additives shown in Table 1 were further added in predetermined amounts, and the temperature was raised to 150 ° C
After kneading for 3 minutes using a hot roll, it was pulverized to obtain a molding powder of the phenol resin composition.

The obtained molding powder was heated at 160 ° C. and 100 kg /
20 minutes after compression molding for 7 minutes under the condition of cm ^2.
After post-curing at 0 ° C. for 7 hours, the following measurement method was used.
Each measurement of hygroscopicity, strength under heat, and heat resistance was performed. The results are shown in Table 2.

(1) Water Absorption Rate The weight increase rate when the phenol resin molded product was kept in steam at 120 ° C. and 2 atm for 24, 48, 72 and 168 hours was shown as water absorption rate.

(2) Strength under heat Bending strength was measured by conducting a bending test at 200 ° C and 250 ° C according to JIS-K-6911.

(3) Heat resistance After the phenol resin molded product was kept in a gear oven at 270 ° C. for 168 hours and 336 hours, the bending strength was measured at room temperature according to JIS-K-6911.

[0038]

[Table 1]

[0039]

Example 2 Phenolic butadiene having a softening point of 120 ° C., a number average molecular weight of 1000 and a hydroxyl group equivalent of 333 g / eq was obtained in the same manner as in Example 1 except that phenol was replaced with o-cresol. After adding the additives shown in Table 1 to the obtained phenolated butadiene polymer, a molding powder of a phenol resin composition was obtained according to Example 1. Table 2 shows each measurement result.

[0040]

[Example 3] Product name "Nisseki Polybutadiene B-700"
Was replaced by the trade name "Nisseki Polybutadiene B-1000" (manufactured by Nippon Petrochemical Co., Ltd., number average molecular weight 1000) in the same manner as in Example 1 except that the softening point was 150 ° C and the number average molecular weight was 1500. A phenolized butadiene polymer having a hydroxyl equivalent of 355 g / eq was obtained. After adding the additives shown in Table 1 to the obtained phenolated butadiene polymer, a molding powder of a phenol resin composition was obtained according to Example 1. Table 2 shows each measurement result.

[0041]

[Example 4] Product name "Nisseki Polybutadiene B-700"
Was replaced by the trade name "Nisseki Polybutadiene B-1800" (manufactured by Nippon Petrochemical Co., Ltd., number average molecular weight 1800), in the same manner as in Example 1 except that the softening point was 180 ° C and the number average molecular weight was 2500. A phenolized butadiene polymer having a hydroxyl equivalent of 325 g / eq was obtained. After adding the additives shown in Table 1 to the obtained phenolated butadiene polymer, a molding powder of a phenol resin composition was obtained according to Example 1. Table 2 shows each measurement result.

[0042]

[Comparative Example 1] A phenol resin composition having a softening point of 83 ° C,
Molded powder was obtained in the same manner as in Example 1 except that the phenol novolac resin having a number average molecular weight of 600 and a hydroxyl group equivalent of 104 g / eq was used instead. Table 2 shows each measurement result.

[0043]

COMPARATIVE EXAMPLE 2 A phenol resin composition obtained by reacting p-xylylenedimethyl ether with phenol in the presence of an acid catalyst has a softening point of 92 ° C. and a number average molecular weight of 280.
A molding powder was obtained in the same manner as in Example 1 except that the phenol araalkyl resin having 0 and a hydroxyl equivalent of 190 g / eq was used instead. Table 2 shows each measurement result.

[0044]

Comparative Example 3 Dicyclopentadiene having a softening point of 103 ° C., a number average molecular weight of 800 and a hydroxyl equivalent of 178 g / eq, which is obtained by reacting a phenol resin composition with dicyclopentanediene and phenol in the presence of an acid catalyst. Molded powder was obtained according to Example 1, except that the phenol resin was used instead. Table 2 shows each measurement result.

[0045]

[Table 2]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Otsuki 8 Chidori-cho, Naka-ku, Yokohama-shi, Kanagawa Nihon Sekiyu Co., Ltd. Central Technology Research Institute

Claims (1)

[Claims] 1. 100 parts by weight of (A) a phenolized butadiene polymer having a number average molecular weight of 500 to 5000 obtained by reacting a butadiene polymer with a phenol compound in the presence of an acid catalyst, and (B) a curing agent 5 to A phenolic resin composition containing 20 parts by weight as an essential component.