JPS6248985B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a phenolic resin composition which is used to produce a cured product having excellent electrical properties and extremely good punching workability, particularly a laminate suitable for arranging and holding electrical parts. It is about things. In recent years, due to technological innovations in communication equipment and electronic equipment, a high ratio of electrical and physical properties of laminates has become required. Further, from the viewpoint of automation of processing equipment, labor saving, etc., laminates are required to have excellent punching characteristics at room temperature or relatively low temperatures around room temperature. In response to these demands, methods have been tried in the past, such as adding thermoplastic polymers and plasticizers to phenolic resins, using phenol derivatives with long-chain hydrocarbon substituents as raw materials, and incorporating rubber into them. Ta. However, these methods do not provide sufficient flexibility, deteriorate electrical or physical properties, or
The work efficiency is deteriorated and a fully satisfactory result is not obtained. A method has also been proposed in which phenols are reacted with drying oil or liquid polybutadiene in the presence of an acid catalyst and then reacted with formaldehyde to produce a flexible phenolic resin for laminated boards. However, the addition of phenols to drying oils or liquid diolefin polymers having non-conjugated double bonds is relatively slow, and side reactions such as cyclization and polymerization of the double bond portion also occur. Therefore, when trying to add a large amount of phenol, these side reactions also occur actively, resulting in a high molecular weight that becomes difficult to dissolve in polar solvents when made into varnish, poor compatibility with phenolic resin, and paper or cloth. Penetration is poor and smearing. Due to these drawbacks, it is difficult to obtain a laminate with good properties. Drying oils with conjugated double bonds, such as phenolic resins modified with tung oil, have relatively few of the above-mentioned drawbacks and can provide excellent flexibility, but because they are natural oils, price fluctuations are large, and the development of electronic technology New flexibility-imparting agents are desired because we have reached the stage where we can no longer meet the increasing levels of physical and electrical properties required by the industry. (A) (a) Maleic anhydride adducts of drying oils having conjugated and/or non-conjugated double bonds have the general formula (Ar is an aryl group, R ₁ is an alkyl group or an aralkyl group having 1 to 20 carbon atoms) and (b) a drying oil with a half-amide group obtained by reacting an aromatic secondary amine represented by an aryl group and a number average molecular weight of General formula for maleic anhydride adducts of butadiene polymers and/or copolymers from 300 to 10,000 (A'r is an aryl group, _R2 is an alkyl group or an aralkyl group having 1 to 20 carbon atoms) Butadiene polymer and/or copolymer having a semi-amide group obtained by reacting an aromatic secondary amine represented by A curable phenolic resin composition containing as an essential component a resol type phenolic resin obtained by reacting one or two selected from among the combinations and (B) phenols and formaldehyde in the presence of an alkali catalyst. It is. The drying oil semi-amidated with an aromatic secondary amine contained as one of the phenolic resin compositions used in the present invention will be described. Drying oils having conjugated and/or non-conjugated double bonds with an iodine value of 100 or more that can be employed in the present invention include linseed oil, edible oil, and linseed oil containing linolenic acid, linoleic acid, and eleostearic acid as main components; Examples include soybean oil, tung oil, dehydrated castor oil, and the like. The maleic anhydride adduct of drying oil in the present invention can be produced by a conventionally known method of reacting the drying oil and maleic anhydride at a temperature of 50 to 300°C. In the case of a drying oil having a conjugated double bond, maleic anhydride is added by the Diels-Alder mechanism, so the maleation reaction can be carried out at a relatively low temperature of 50 to 150°C. On the other hand, in the case of drying oils having non-conjugated double bonds, it is better to carry out the treatment at a somewhat higher temperature, such as 150 to 300°C. The reaction temperature can also be lowered somewhat by adding a small amount of organic peroxide or by using an aerated drying oil. A gelling inhibitor is usually not required during the maleic anhydride addition reaction, but depending on the reaction conditions, a small amount of phenylene diamines, pyrogallols, naphthols, etc. may be added to prevent the gelling reaction. The amount of maleic anhydride added is preferably 0.05 to 1.0 mol, preferably 0.1 to 0.5 mol, per 100 g of drying oil. In the present invention, not only drying oils having conjugated double bonds but also drying oils having non-conjugated double bonds, which have conventionally been difficult to put into practical use for general purposes, can be used. This is because the maleation reaction of drying oils with non-conjugated double bonds is easy, maleic anhydride addition is possible with relatively few side reactions such as polymerization, and half-amide formation with secondary amines is possible. This is because the reaction can be carried out under mild conditions and no undesirable side reactions occur. The maleic anhydride adduct of the drying oil is then reacted with an aromatic secondary amine to yield a semi-amidated drying oil. Succinic anhydride groups attached to drying oils readily react with aromatic secondary amines under mild conditions to give semi-amide compounds. The aromatic secondary amine used in the present invention has the general formula (Here, Ar is an aryl group, R ₁ is a carbon number of 1 to 20
alkyl group or aralkyl group). Ar preferably has 6 to 30 carbon atoms and has hydrogen directly bonded to the aromatic ring. Representative examples of these include N-methylaniline, N-
Ethylaniline, N-butylaniline, α-(N
-methyl)naphthylamine, N-methyltoluidine, and the like. The amount of the aromatic secondary amine to be used is preferably 0.2 to 3.0 in equivalent ratio to the succinic anhydride group. The semi-amidation reaction can be carried out at 0 to 150°C. The reaction is usually very fast, and a reaction time of 1 to 2 hours is sufficient. This reaction can be carried out in the presence or absence of a solvent. When using a solvent, it is preferable to use a hydrocarbon solvent or an ether solvent that is not reactive with amines, carboxylic acid anhydrides, and the like. However, even with reactive compounds such as alcohols, it is also possible to open a part of the succinic anhydride group with alcohol to synthesize and utilize a drying oil that has both half-amide and half-ester groups. It is also possible. Next, the butadiene polymer semi-amidated with an aromatic secondary amine used in the present invention is a butadiene homopolymer having a number average molecular weight of 300 to 10,000 or a butadiene copolymer having 50% or more butadiene units, and anhydrous maleate. It can be synthesized by reacting with an acid and reacting the resulting maleated butadiene polymer with an aromatic secondary amine. First, the raw material butadiene polymer used in the present invention is, for example, one obtained by homopolymerizing butadiene in a hydrocarbon solvent using an alkali metal such as lithium or sodium or an organometallic compound thereof as a catalyst, or one obtained by homopolymerizing butadiene and a vinyl monomer such as styrene. Copolymerization of butadiene and diolefin such as isoprene are preferably used. Also preferably used are butadiene monopolymerized or copolymerized with an alkali metal such as sodium as a catalyst in a polar solvent such as tetrahydrofuran using a polycyclic aromatic compound such as naphthalene or anthracene as an activator. Furthermore, butadiene polymers or copolymers obtained by using a coordination anion polymerization catalyst, and polymers obtained by telomerizing butadiene etc. with a radical initiator can also be used in the same way. . The number average molecular weight of the butadiene polymer referred to in the present invention is in the range of 300 to 10,000, preferably 500 to 5,000. If the molecular weight is too low, the molecular weight between the crosslinking points will be too small, which will not only result in poor flexibility, but also result in poor performance such as strength, heat resistance, and chemical resistance of the cured product. If the molecular weight is too large, the viscosity becomes extremely high, resulting in decreased workability and difficulty in obtaining a uniform cured product. The microstructure of the butadiene polymer used in the present invention is not particularly limited, and either a polymer with many 1,2-bonds or a polymer with many 1,4-bonds can be used. The maleic anhydride adduct of the butadiene polymer or copolymer or mixture thereof of the present invention is produced by a conventionally known method of reacting the above-described butadiene polymer or copolymer with maleic anhydride at a temperature of 100 to 300°C. can. Moreover, a method of suppressing the gelation reaction by adding a small amount of a gelling inhibitor such as phenylene diamines, pyrogallols, or naphthols when carrying out the addition reaction can be preferably employed. In addition, the amount of maleic anhydride added in this reaction is 0.05 to 1.0 mol per 100 g of butadiene polymer or copolymer.
Preferably it is 0.1 to 0.5 mol. The maleic anhydride adduct of butadiene polymer is
Next, a semi-amidated butadiene polymer is obtained by reacting with an aromatic secondary amine. Succinic anhydride groups attached to butadiene polymers readily react with aromatic secondary amines under mild conditions to give semi-amide compounds. The aromatic secondary amine used in the present invention has the general formula (Here, A′r is an aryl group, R ₂ is a carbon number of 1 to 20
is an alkyl group or an aralkyl group. ) is a compound represented by A′r preferably has 6 carbon atoms
-30 and has hydrogen directly connected to the aromatic ring. Representative examples of these include N-methylaniline,
N-ethylaniline, N-butylaniline, α-
Examples include (N-methyl)naphthylamine and N-methyltoluidine. The amount of aromatic secondary amine used is 0.2 to 3.0 in equivalent ratio to succinic anhydride group.
is preferably applied. The semi-amidation reaction can be carried out at 0 to 150°C. The reaction is usually very fast, and a reaction time of 1 to 2 hours is sufficient. This reaction can be carried out in the presence or absence of a solvent. When using a solvent, it is preferable to use a hydrocarbon solvent or an ether solvent that is not reactive with amines, carboxylic acid anhydrides, and the like. However, even with reactive compounds such as alcohols, it is possible to open a part of the succinic anhydride group with an alcohol to synthesize and utilize a butadiene polymer that has both a half-amide group and a half-ester group. is also possible. Similar reaction conditions can be used in the synthesis of the above-mentioned derivatives of the semi-amidated drying oil with an aromatic secondary amine and the above-mentioned butadiene polymer. It is also possible to react an acid and further react with an aromatic secondary amine. The other constituent of the thermosetting resin composition of the present invention, the phenol-formaldehyde resin, is obtained by condensing phenols and aldehydes with a basic catalyst. As the phenols, in addition to phenol, cresol, xylenol, resorcinol, bisphenol, etc. are used alone or in combination. As aldehydes, in addition to formaldehyde, it is also possible to use paraformaldehyde, which decomposes to generate formaldehyde. As the basic catalyst used for phenolic resin condensation, hydroxides of alkali metals or alkaline earth metals, ammonia, amines, etc. are preferably used. The drying oil semi-amidated with an aromatic secondary amine, butadiene polymer derivative and phenol-formaldehyde resin can be synthesized separately and used as a mixture, or the drying oil semi-amidated with an aromatic secondary amine can be used. It is also possible to condense phenols with formaldehyde in the presence of drying oils and/or derivatives of butadiene polymers. Drying oil semi-amidated with aromatic secondary amines,
The mixing ratio of the butadiene polymer derivative and the phenol-formaldehyde resin can be varied over a wide range, and cured products having various properties can be obtained depending on the mixing ratio. When a drying oil semi-amidated with an aromatic secondary amine or a derivative of a butadiene polymer is blended alone with a phenol-formaldehyde resin, the amount of the drying oil derivative or a derivative of a butadiene polymer and the phenol-formaldehyde resin. The weight ratio is 5/95 to 80/20, and even 20/80 to 60/40.
The following range is preferably adopted in order to obtain a cured product having desirable characteristics. In addition, when a drying oil derivative and a butadiene polymer derivative are used at the same time, the weight ratio of the total amount of both to the amount of phenol-formaldehyde resin is 5/95 to 80/20, or even 20/80 to 60. A range of /40 is preferably adopted in order to obtain a cured product having desirable properties. Here, the weight ratio of the drying oil semiamidated with an aromatic secondary amine and the butadiene polymer derivative can be, for example, 5:95 to 95:5. The thermosetting resin composition of the present application can be cured at a temperature of 100 to 250°C without particularly adding a catalyst. In order to obtain a laminate plate suitable for arranging and holding electrical components, such as a wiring printed board or a chassis board, using this thermosetting resin, it is preferable to carry out the following procedure, for example. That is, the drying oil semi-amidated with an aromatic secondary amine and/or a butadiene polymer derivative contained in the thermosetting resin composition, and the phenol-formaldehyde resin are mixed with alcohols such as methanol, ethanol, butanol, and acetone. , ketones such as methyl ethyl ketone, and aromatic hydrocarbons such as benzene, toluene, and xylene. Next, the above-mentioned varnish is impregnated into a fibrous base material for a laminate and dried to obtain a laminate material having a dry resin content of 30 to 70% by weight, preferably 35 to 55% by weight. Paper as a fibrous base material;
Cloth, synthetic fiber cloth, asbestos cloth, glass cloth, etc. are used. The semi-amidated drying oil and butadiene polymer derivatives of the present invention have excellent solubility in methanol-based solvents and provide a varnish with extremely low viscosity, so it has excellent permeability into fibrous substrates. ing. Laminate the desired number of layers of this laminated material, usually 20 to 200.
Kg/cm ² , temperature 130 to 180°C, and time 20 to 180 minutes to mold by thermocompression to obtain a final product, a laminate. Furthermore, the phenolic resin composition of the present invention not only exhibits excellent flexibility when cured, but also a drying oil semi-amidated with an aromatic secondary amine and a drying oil semi-amidated with an aromatic secondary amine. Butadiene polymer has excellent compatibility with phenolic resin and has a fast curing reaction with phenolic resin, so the crosslinking density is kept high, making it possible to produce laminates with excellent boiling resistance, heat resistance, solvent resistance, and dimensional stability. Obtainable. The resin composition of the present invention can be widely applied not only to laminate products but also to fields such as electrical insulation coatings. The present invention will be specifically explained below using Examples. Synthesis example 1 1000g of linseed oil and 333g of maleic anhydride at 195℃
The mixture was reacted for 3 hours to obtain maleated linseed oil with an acid value of 143 mgKOH/g. 1000g of the above maleated linseed oil, toluene 636
g was placed in a 3-separable flask equipped with a reflux condenser and heated to 50°C, and 273 g of N-methylaniline was added dropwise over about 30 minutes while stirring. 50 minutes after completion of dripping
After stirring was continued for 1 hour while maintaining the temperature at °C, the mixture was cooled to room temperature and 636 g of methanol was added to obtain a varnish with a resin concentration of 50% by weight. Synthesis Example 2 Number average molecular weight 980, synthesized by polymerizing butadiene using a sodium catalyst.
1000g of butadiene polymer with 58% vinyl bonds and 325g of maleic anhydride were reacted at 195℃ for 5 hours to obtain an acid value.
A maleated butadiene polymer containing 140 mgKOH/g was obtained. 1000 g of the above maleated butadiene polymer and 634 g of toluene were placed in a 3-separable flask equipped with a reflux condenser, heated to 50° C., and 268 g of N-methylaniline was added dropwise over about 30 minutes while stirring. After the dropwise addition was completed, the mixture was kept at 50° C. and stirred for 1 hour, then cooled to room temperature and 634 g of methanol was added to obtain a varnish with a resin concentration of 50% by weight. Synthesis Example 3 485 g of 37% formaldehyde aqueous solution, 470 g of phenol and 34 g of 25% ammonia aqueous solution were heated at 90°C.
After the mixture was reacted for 30 minutes and dehydrated under reduced pressure, a mixed solution of toluene and methanol (1:1 weight ratio) was added to obtain a varnish with a resin concentration of 50% by weight. Examples 1 to 3 The varnishes thus obtained were blended in the proportions shown in the table below, and kraft paper was impregnated with the resulting mixed varnish. All varnishes had excellent permeability into paper. After drying, a resin-impregnated paper with a resin content of 50% by weight was obtained. Nine sheets of this resin-impregnated paper were stacked together and heated and pressed for 45 minutes at 150° C. and 100 kg/cm ² to obtain a laminate with a thickness of 1.6 mm. The properties of this laminate are shown in the table below. Comparative Example 1 500 g of tung oil, 756 g of metacresol, and 2 g of para-toluenesulfonic acid were mixed and reacted at 100° C. for 2 hours. Next, 738 g of 37% formalin and 48 g of 25% aqueous ammonia were added and reacted at 90°C for 3 hours.
Water was removed under reduced pressure and methanol-toluene (1
1 weight ratio) was added to prepare a varnish with a resin concentration of 50% by weight. Kraft paper was impregnated with the varnish thus obtained and dried to obtain resin-impregnated paper with a resin content of 50% by weight. This was made into a laminate under exactly the same conditions as Examples 1 to 3. The properties of the laminate are shown in the table below. Comparative Example 2 500 g of linseed oil, 756 g of metacresol, and 3 g of paratoluenesulfonic acid were mixed and reacted at 120° C. for 2 hours. Next, 738 g of 37% formalin and 48 g of 25% aqueous ammonia were added and reacted at 90°C for 3 hours.
Water was removed under reduced pressure and methanol-toluene (1
1 weight ratio) was added to prepare a varnish with a resin concentration of 50% by weight. Kraft paper was impregnated with the varnish thus obtained and dried to obtain resin-impregnated paper with a resin content of 50% by weight. Example 1
A laminate was prepared under exactly the same conditions as in ~3. The properties of the laminate are shown in the table below. As is clear from the results shown in the table below, compared to conventional phenolic resins modified with tung oil and linseed oil, drying oil semi-amidated with aromatic secondary amines, butadiene polymer derivatives, and mixtures of the two are more effective than resols. It is clear that when blended with mold phenolic resin, solvent resistance, heat resistance, and punching workability are improved without deteriorating electrical properties. 【table】

Claims (1)

[Claims] 1 (A) (a) A maleic anhydride adduct of a drying oil having a conjugated and/or non-conjugated double bond with the general formula (Ar is an aryl group, R ₁ is an alkyl group having 1 to 20 carbon atoms or an aralkyl group) A drying oil having a semi-amide group obtained by reacting an aromatic secondary amine represented by General formula for maleic anhydride adducts of butadiene polymers and/or copolymers from 300 to 10,000 (A'r is an aryl group, _R2 is an alkyl group or an aralkyl group having 1 to 20 carbon atoms) A butadiene polymer and/or copolymer having a semi-amide group obtained by reacting an aromatic secondary amine represented by A curable phenolic resin composition containing as an essential component a resol-type phenolic resin obtained by reacting one or two selected from the group consisting of (B) phenols and formaldehyde in the presence of an alkali catalyst.