JPS6118565B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a modified phenolic resin for laminates. More specifically, the present invention relates to a method for producing a modified phenolic resin for laminates (hereinafter abbreviated as LB modified resol) obtained by reacting polybutadiene with formaldehyde. The laminate using the modified phenolic resin obtained by the present invention has excellent machinability, chemical resistance, hardening properties, etc., and is equivalent to or better than the conventionally used phenolic resin modified with drying oil. It is characterized by its physical properties and being manufactured at low cost. Although phenolic resins generally have excellent properties such as water resistance, heat resistance, and electrical properties, they are hard and brittle, and cannot be used alone, so they are used in combination with various base materials. For laminates, paper, cotton cloth, asbestos paper,
It is widely used as an electrical insulating material by impregnating uncured phenolic resin into a base material such as asbestos cloth or glass cloth, then layering several sheets together and then heating and pressing them to form a sheet. Among these, paper phenol laminates with a thickness of about 0.8 to 3.2 mm and copper-clad laminates for printed wiring boards are often used for light electrical equipment. In the latter case, when inserting components such as resistors, diodes, and capacitors using an automatic insertion machine, punching workability at room temperature is required to improve the punching dimensional accuracy, and it is necessary to insert parts such as resistors, diodes, capacitors, etc. Modified resols modified with modifying agents such as vegetable oils, alkylphenols, and polyethers are used to impart flexibility. Currently, tung oil is a typical modifier, but if it is a natural product, the market fluctuates significantly and is expensive, as most of the products in Japan are imported, and the supply is not stable. Therefore, there is a strong demand for the supply of modified resols using synthetic drying oil as a modifying agent instead of tung oil. The present invention relates to a method for producing a modified phenolic resin for laminates that meets these demands,
It is characterized in that a specific polybutadiene is reacted with one or more phenols instead of tung oil, which is conventionally used to impart flexibility to phenolic resin laminates. Conventionally, a method for synthesizing an adduct of a conjugated diolefin polymer and a phenol has been disclosed in JP-A No. 48-20890.
Publication No. 49-53628, Japanese Patent Publication No. 53628-
Methods such as those disclosed in Publication No. 61493 and Japanese Unexamined Patent Publication No. 47-39220 are known. Although JP-A No. 49-53628 discloses the use of the same as a coating material, there is no mention of its use in laminates. On the other hand, a method for obtaining a methylolated product by reacting an adduct of a conjugated diolefin polymer and a phenol with formalin was disclosed in Japanese Patent Application Laid-Open No. 1973-
Although the specification of Publication No. 20890 states that it can be converted into methylol, there are no examples, and there is no indication that it can be used in a phenol laminate. Also, JP-A-48-79895, JP-A-47-43312
The publication discloses that 1,2 type polybutadiene is added with phenol and then converted into methylol to form a phenol laminate. The reason why it was limited to type 1,2 polybutadiene is, for example, in the
As shown in Japanese Patent No. 43312, polybutadiene with 1,2-type bonds of 20% or less was considered unfavorable from the viewpoint of performance and compatibility because the amount of addition with phenols is small. Furthermore, JP-A-109285 discloses a resin in which polybutadiene containing about 40% vinyl groups is converted into methylol after addition of phenol, but does not disclose its use in phenol laminates. Under these circumstances, the present inventors conducted various studies on polybutadiene as a modifier in order to produce an excellent modified phenolic resin for laminates, and found that it is possible to use polybutadiene rich in type 1 and 2 structures. During the addition reaction with phenol, the coexisting Lewis acid catalyst causes a violent cyclization reaction of the double bonds of polybutadiene at the same time as the addition reaction, resulting in a high glass transition point of the cured resin obtained by curing the LB modified sol. It was found that the flexibility was insufficient. Therefore, the inventors have developed a method that does not have such drawbacks.
As a result of intensive studies to produce LB modified resol, we found that using polybutadiene with 80% or more of 1,4 type structure as a modifier can improve the performance of laminates, especially the flexibility required during processing. The present invention was completed after discovering that the present invention is effective and performing various studies. In other words, the present invention uses polybutadiene having 80% or more of the 1,4 type structure and a hydrocarbon or/and
and a halogenated hydrocarbon in the presence of a Lewis acid catalyst to form a composition (A).
The present invention provides an excellent method for producing a modified phenolic resin for laminates, which is characterized by reacting the composition (A) with formaldehyde in the presence of a solvent and a basic catalyst. The LB-modified resol produced by the present invention uses a polybutadiene rich in 1,4 structures, and uses a hydrocarbon or/and halogenated hydrocarbon as a solvent during the addition reaction with phenols. As a result of suppressing the chemical reaction, the compatibility improves, resulting in a uniform varnish, and when it is made into a resin, a laminate with good transparency and solvent resistance, a low glass transition temperature, and extremely excellent flexibility can be obtained. It will be done. The polybutadiene used in the present invention has at least 80% of the 1,4 type structure. The number average molecular weight of this polybutadiene is 150
A range of 10,000 to 10,000 is preferred. Phenols in the present invention include phenol, cresol, xylenol, n-propylphenol, isopropylphenol, n-butylphenol, paratertiary butylphenol, alkylphenols such as nonylphenol, resorcinol, hydroquinone, catechol, saligenin, etc. Examples include monohydric or polyhydric phenols, and mixtures thereof can also be used. In addition, the solvent used for this phenol addition reaction has a solvent dielectric constant of 15 or less at 25°C, preferably
10 or less, and for example, hydrocarbons such as benzene, toluene, xylene, n-beptane, n-hexane, and cyclohexane, and halogenated hydrocarbons such as monochlorobenzene and dichlorobenzene can be used. The amount of solvent to be used is preferably 5 to 500 parts by weight, preferably 10 to 100 parts by weight, per 100 parts by weight of polybutadiene. In this case, if it is less than 5 parts by weight based on 100 parts by weight of polybutadiene, the curing properties of the final resin varnish will be poor, and when heated at 160°C for 20 minutes, the resulting cured product will be uneven and transparent. Moreover, if it exceeds 500 parts by weight, the addition rate of phenol to polybutadiene is low, resulting in poor uniform curing properties. In the present invention, when producing the composition (A) from polybutadiene and phenols, 10 to 1000 parts by weight, preferably 50 to 300 parts by weight of phenols are added to 100 parts by weight of polybutadiene, and 0.01 parts by weight of phenols are added. Polybutadiene is added all at once, preferably in portions, to the mixture with 10 parts by weight of Lewis acid catalyst. In this case, if the amount of one or more phenols is less than 10 parts by weight per 100 parts by weight of polybutadiene, the curing speed of the LB modified resol will be insufficient when processing the LB modified resol into a laminate, and Poor chemical resistance required for boards. Also, one or more phenols are added to 100 parts by weight of polybutadiene.
If the amount exceeds 1000 parts by weight, the room-temperature punching workability of the obtained laminate decreases. Also, the phrase "add in portions" means that the phenol and Lewis acid catalyst are not added to the mixture all at once.
It refers to the purposeful operation of mixing continuously within a certain period of time or discontinuously mixing parts of the mixture in several batches at certain time intervals. However, regarding the addition time and addition interval time,
There are no particular limitations. These are determined by the relationship between the molecular weight and chemical structure of polybutadiene, the quantitative ratio of polybutadiene and phenol, the Lewis acid catalyst, and the reaction temperature. Examples of the Lewis acid catalyst used in the present invention include aluminum chloride, ferric chloride, boron triboride, and boron triborate phenol complex. The concentration of the catalyst can be arbitrarily selected within the range of 0.01 parts by weight to 10 parts by weight based on 100 parts by weight of the polymer. The reaction temperature is not particularly limited, but is preferably from 40°C to 170°C. In the present invention, when formaldehyde is reacted with composition (A), in the presence of a basic catalyst, it is 0.6 to 3.0 mol in terms of formaldehyde based on the total amount of phenols used to produce the resol resin.
It is preferred to use an amount of formalin or paraformaldehyde corresponding to . If the amount is less than 0.6 mol, methylolization will not be sufficient, and the performance of the laminate produced from the obtained LB modified resol will be poor, especially the curing properties and solvent resistance. If it is more than 3.0 mol, the methylolation rate will be extremely high, making it difficult to control the reaction. Therefore, it is inappropriate for practical use. In addition, the basic medium used in the present invention is ammonia, hexamethylenetetramine, trimethylolamine, ethylenediamine, dimethylamine,
Examples include amines such as diethylamine and triethylamine, and hydroxides such as sodium hydroxide, potassium hydroxide, barium hydroxide, etc., and one or more of these may be used in combination. is possible. The amount of the catalyst used can be arbitrarily selected within the range of 0.001 to 0.5 mol based on the total amount of phenol used to produce composition (A). Other reaction conditions are not particularly limited, but the reaction temperature is preferably 60℃~
The mixture is reacted at 120°C for 60 to 180 minutes and used as a varnish, or it is subsequently dehydrated under reduced pressure and diluted with a solvent that provides uniformity. As the solvent used in the methylolation reaction, hydrocarbons, halogenated hydrocarbons, alcohols, ethers, ketones, esters, etc. are used. Examples of hydrocarbons include benzene, toluene, xylene, diylene, hexane, heptane, pentane, and octane. Examples of halogenated hydrocarbons include monochlorobenzene, monobromobenzene, dichlorobenzene, dichloroethane, perchloroethylene, hexyl chloride, and octyl chloride, and benzene, toluene, xylene, etc. are preferred because they are inexpensive. Alcohols are alcohols having 1 to 27 carbon atoms, such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, tert-butyl alcohol, and n-butyl alcohol. Amyl alcohol, sec-
amyl alcohol, diethylmethanol, isoamyl alcohol, tert-amyl alcohol, tert
-Butylmethanol, methylisopropylmethanol, n-hexyl alcohol, methylisobutylcarbinol, methylamylcarbinol, n
-heptyl alcohol, methyl-n-amylcarbinol, n-octyl alcohol, caprylic alcohol, 2-ethyl-n-hexyl alcohol, isooctyl alcohol, n-nonyl alcohol, n-decyl alcohol, n-undecyl alcohol, n- -Dodecyl alcohol, n-tridecyl alcohol, n-tetradecyl alcohol,
Saturated monohydric alcohols such as n-pentadecyl alcohol, cetyl alcohol, stearyl alcohol, n-nonadecyl alcohol, behenyl alcohol and cyclohexanol, allyl alcohol, propargyl alcohol, crotyl alcohol, oleyl alcohol, elaidyl alcohol, linoleyl alcohol and unsaturated monohydric alcohols such as geraniol, aromatic alcohols such as benzyl alcohol, β-phenylethyl alcohol and hydrocinnamyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene One or a mixture of two or more of ether alcohols such as glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, triethylene glycol monomethyl ether, furfuryl alcohol and tetrafurfuryl alcohol can be used. Dihydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, propanediol and butanediol can also be used, but low molecular weight alcohols are preferred so that the solvent can be easily removed during the drying process when the varnish is pre-dried. . Examples of the ether include dimethyl ether, diethyl ether, dipropyl ether, and tetrahydrofuran. Examples of ketones include acetone, diethyl ketone, dipropyl ketone, and cyclohexanone. As esters, ethyl formate, ethyl acetate,
Includes isoamyl acetate, ethyl butyrate, etc. When a mixture of hydrocarbon and alcohol is used, the amount is preferably 0 to 100 parts by weight, preferably 0 to 5 parts by weight, per 1 part by weight of the hydrocarbon. Further, the amount of the solvent is 1 to 2000 parts by weight, preferably 20 to 500 parts by weight, per 100 parts by weight of the composition (A). The method for producing a laminate plate using the LB modified resol obtained by the present invention is a conventional method that can be applied as it is. The resin of the present invention can be impregnated into a base material such as and dried to form a prepreg, or the base material is first impregnated with a predetermined amount of water-soluble phenolic resin and/or amine-modified phenolic resin and dried. A desired laminate plate is obtained by impregnating and drying a fixed amount to form a prepreg, and then laminating the required number of sheets and molding them by hot pressing. Examples are shown below, but the present invention is not limited to the following examples. Example 1 Viscosity at 20°C is 660 centipoise, number average molecular weight is 1700 as measured by non-pressure permeameter, physical properties include cis 1,4 structure of 70% or more, trans 1,4 structure of 20% or more, and vinyl structure of 3% or less. 100g of liquid polybutadiene heated to 70℃~75℃, 15g of phenol, 50g of toluene and 0.5g of _BF3 /phenol complex salt.
Mix dropwise into the mixture for 20 minutes and then heat to 80°C.
After reacting with stirring for 2 hours, 1.0 g of triethylamine was added to obtain composition (A). This composition (A) is a mixture of liquid polybutadiene-phenol adduct and unreacted phenol, and analysis results confirmed that the former contains an average of 7.5 molecules of phenol per molecule of liquid polybutadiene. . For 100 g of this obtained composition (A), 20.8 g of paraformaldehyde, hexamethylenetetramine
1.5g, 68g of toluene as a solvent, and 32g of isopropyl alcohol were added to the reactor and heated to 80°C with stirring.
After reacting at ~83℃ for 2 hours, concentrate under reduced pressure to remove the resin content.
A 50% by weight uniform transparent LB modified resol varnish was produced. Cotton linter paper, which had been previously undercoated with a water-soluble phenol formaldehyde varnish for undercoating, was impregnated with the above varnish and dried to produce a resin-impregnated base material with a resin adhesion content of 45% by weight. Layer the specified number of sheets together and heat to 160℃80.
A resin laminate with a thickness of 1.6 mm was manufactured by heat-pressing for 50 minutes under lamination conditions of Kg/cm ² to 100 Kg/cm ² . Example 2 To 100 g of the composition (A) obtained in Example 1, 20.8 g of paraformaldehyde, 3.0 g of hexamethylenetetramine, 52 g of toluene and 48 g of isopropanol as solvents were added to a reactor, and the mixture was heated to 80 g with stirring.
After reacting for 2 hours at 83°C to 83°C, the mixture was concentrated under reduced pressure to produce a homogeneous and transparent LB modified resol varnish with a resin content of 50% by weight. The thickness was measured in the same manner as in Example 1.
A 1.6 mm resin laminate was obtained. Comparative Example 1 100g of liquid polybutadiene used in Example 1
15g of phenol heated to 70℃~75℃ and BF ₃ .
It was added dropwise to a mixture of 0.5 g of phenol complex salt over 20 minutes and reacted with stirring at 80°C for 2 hours, and then 1.0 g of triethylamine was added to form composition (A).
I got it. The thickness is 1.6mm using the same method as in Example 1.
A resin laminate was obtained. Table 1 shows the characteristics of the LB modified resol varnish and resin laminate described in the Examples and Comparative Examples above for comparison.
Shown below.

[Table] From Table 1, Examples 1 and 2 in which the addition reaction between polybutadiene and phenol was carried out in a toluene solvent, and the reaction between the adduct and formaldehyde (methylolation reaction) were carried out in a mixed solvent of toluene and isopropyl alcohol. It can be seen that, compared to Comparative Example 1 in which both the addition reaction and the methylolation reaction were carried out without using a solvent, the transparency, curability, punching workability of the laminate, and solvent resistance were significantly superior.

Claims (1)

[Claims] 1 Composition (A ) and then reacting the composition (A) with formaldehyde in the presence of a solvent and a basic catalyst. 2 The number average molecular weight of polybutadiene is 150 to 10,000
The manufacturing method according to claim 1. 3 10 to 1000 per 100 parts by weight of polybutadiene
3. The method according to claim 1, wherein polybutadiene is added to the mixture using parts by weight of phenols and 0.01 to 10 parts by weight of Lewis acid catalyst. 4 Claims 1 to 8 in which 5 to 500 parts by weight of hydrocarbon or/and halogenated hydrocarbon are used as a solvent based on 100 parts by weight of polybutadiene.
Manufacturing method described in section. 5. Claims 1 to 5, in which, when formaldehyde is reacted with composition (A), formalin or paraformaldehyde is used in an amount equivalent to 0.6 to 3.0 mol in terms of formaldehyde based on the total amount of phenols used. The manufacturing method described in Section 4. 6. The manufacturing method according to claims 1 to 5, wherein 1 to 2000 parts by weight of the solvent is used per 100 parts by weight of the composition when formaldehyde is reacted with the composition (A).