JPH04250034A - Manufacture of modified phenol resin laminated sheet - Google Patents

Abstract

PURPOSE:To develop the above modified phenol resin laminated sheet with high mechanical strength, heat resistance and electric insulating properties. CONSTITUTION:The modified phenol resin laminated sheet is made by using material varnish prepared by dissolving specific modified phenol resin with which a lamination material such as glass cloth is impregnated to be followed by procedures such as drying and lamination molding.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a method for producing a modified phenolic resin laminate, and more specifically, a varnish prepared by dissolving a specific modified phenolic resin in an organic solvent is used as a raw material, and a laminated base material such as glass cloth is impregnated with the varnish. The present invention relates to a method for efficiently producing a modified phenolic resin laminate having excellent physical properties such as mechanical strength, heat resistance, and electrical insulation by drying and laminating.

0002

[Prior Art] Phenolic resin laminates, which are generally used as electrical insulating materials and various other industrial materials, are made of resol-type phenolic resin obtained by reacting phenols such as phenol and alkyl-substituted phenols with formaldehyde. It is manufactured by impregnating a fibrous base material with varnish and drying it, then laminating a predetermined number of semi-cured laminated materials and molding them. However, these materials have insufficient physical properties such as electrical insulation and heat resistance, and improvements are desired.

Under such circumstances, the reaction product obtained by reacting aromatic hydrocarbon formaldehyde resin with phenols containing trifunctional or higher functional phenols under an acidic catalyst contains drying oil, rosin, etc. and formaldehyde in a predetermined ratio, heat the reaction under an alkali catalyst to produce a resol-type oil-modified aromatic hydrocarbon phenol resin varnish, and impregnate a base material for a laminate with this varnish to produce a resin laminate. It is proposed to do (
(Special Publication No. 51-16068).

[0004] Furthermore, mesitylene resin obtained by reacting formaldehyde with alkylbenzene, mainly mesitylene, is modified with a drying oil and phenols in the presence of an acidic catalyst, and then the modified resin is treated with formaldehyde in the presence of a basic catalyst. It has been proposed to use a dry oil-modified mesitylene-phenol-formaldehyde resin obtained by reacting with a resin to form a resol as a resin for laminates (Japanese Patent Publication No. 5707/1983). Furthermore, a technique has been reported in which a large amount of magnesium hydroxide is contained in the resin of a laminated plate formed by impregnating a phenolic resin into a glass fiber nonwoven fabric (Japanese Patent Application Laid-Open No. 2-39928).

[0005]

[Problems to be Solved by the Invention] However, even with these resin laminates, electrical insulation properties, heat resistance, etc. are still insufficient, and further improvements are required. Therefore, it is desired to develop a phenolic resin laminate that has well-balanced improvements in various physical properties such as electrical insulation, heat resistance, mechanical strength, and water resistance. By the way, the group of the present inventors recently succeeded in developing a modified phenolic resin with excellent various physical properties (Japanese Patent Application Laid-open No. 2-274714).
Its use is being expanded.

[0006]

[Means for Solving the Problems] Under these circumstances, the present inventors have conducted extensive research in order to solve the above-mentioned conventional problems and develop a phenolic resin laminate with excellent various physical properties. It has been found that a resin laminate meeting the above purpose can be obtained by using a varnish in which the above-mentioned modified phenol resin is dissolved in an organic solvent in the process. The present invention was completed based on this knowledge.

That is, the present invention provides aromatic hydrocarbon fraction f
a value is 0.40 to 0.95, aromatic ring hydrogen amount Ha is 20
A formaldehyde polymer is mixed with 1 mole of petroleum heavy oil or pitch having a concentration of ~80% so that the number of moles in terms of formaldehyde is 1 to 10, and the mixture is heated and stirred in the presence of an acid catalyst. At the same time, phenols are added at a rate of 0.05 to 5% by weight/min based on the total weight of the petroleum heavy oil or pitch and the formaldehyde polymer. A modified phenol resin obtained by polycondensation such that the number of moles of phenol added per mole of oil or pitch is 0.3 to 5 is dissolved in an organic solvent to obtain a varnish, and then The present invention provides a method for producing a modified phenolic resin laminate, which comprises impregnating a laminated base material with the varnish, drying the varnish, and then laminating and molding the obtained prepreg.

First, the modified phenol resin used in the method of the present invention will be explained. This modified phenol resin is obtained by polycondensing specific petroleum heavy oils or pitches with a formaldehyde polymer under certain conditions. Here, the petroleum-based heavy oils or pitches must have an aromatic hydrocarbon fraction fa value of 0.40 to 0.95 and an aromatic ring hydrogen content Ha value of 20 to 80%. In addition, this aromatic hydrocarbon fraction fa value and aromatic ring hydrogen amount Ha
is shown in the following formula. Fa value = (number of aromatic carbons in oil or pitch) / (total number of carbons in oil or pitch) Ha value = (number of aromatic hydrogens in oil or pitch) / (total number of hydrogens in oil or pitch) ×100 This fa value can be determined by 13C-NMR. Further, the Ha value can be determined by 1H-NMR.

[0009] In producing the modified phenolic resin used in the method of the present invention, as the fa value of petroleum heavy oils or pitches decreases, the aromatic content decreases.
The effect of improving the performance of the resulting modified phenolic resin tends to be small. In particular, if the fa value is less than 0.4, this modification effect becomes extremely small, which is not preferable. Further, in the case of petroleum heavy oils or pitches having an fa value greater than 0.95, the reactivity between aromatic ring hydrogen and formaldehyde decreases, which is not preferable. Therefore, f
The a value is preferably 0.4 to 0.95, particularly preferably 0.
．． It is 5 to 0.8. In addition, when the Ha value of raw petroleum heavy oils or pitches decreases, the amount of aromatic ring hydrogen that reacts with formaldehyde decreases, resulting in poor reactivity, which reduces the effect of improving the performance of phenolic resins. Undesirable. H
Regarding the a value, it is considered that 20% or more is practical. On the other hand, as the Ha value increases, the reactivity of aromatic ring hydrogen tends to gradually decrease. Ha value is 8
When using petroleum-based heavy oils or pitches larger than 0% as raw materials, the strength of the modified phenolic resin decreases,
Furthermore, the strength of the resin laminate obtained using this tends to decrease, which is not preferable. In the present invention, H
The a value is preferably 20 to 80%, particularly preferably 25
~60%.

[0010] The number of condensed rings in the petroleum heavy oils or pitches used here is not particularly limited, but it is preferably a condensed polycyclic aromatic hydrocarbon having mainly 2 to 4 rings. In the case of fused polycyclic aromatic hydrocarbons with 5 or more rings,
Since the boiling point exceeds 450° C. in most cases, it is difficult to collect materials with a narrow boiling point range, and there is a problem that the quality is unstable. Furthermore, when the hydrocarbon is mainly a monocyclic aromatic hydrocarbon, the reactivity with formaldehyde is low, so there is a problem that the effect of modifying the performance of the phenol resin is small.

The petroleum heavy oils or pitches that are raw materials for the modified phenolic resin used in the present invention include crude oil distillation residue, hydrogen cracked residue, catalytic cracked residue, naphtha, or LPG.
They are obtained as pyrolysis residual oils, vacuum distillates of these residual oils, extracts by solvent extraction, or heat-treated products, and those with appropriate fa and Ha values are selected from these and used. In addition, formaldehyde polymers, which are raw materials for modified phenolic resins, include paraformaldehyde, polyoxymethylene (especially oligomers)
and cyclic polymers such as trioxane.

The mixing ratio of petroleum heavy oils or pitches and formaldehyde polymer is the formaldehyde polymer in terms of formaldehyde per 1 mole of the average number of moles calculated from the average molecular weight of the petroleum heavy oil or pitch. The number of moles is 1 to 10. If this mixing ratio is less than 1, the strength of the resulting resin laminate will not be sufficiently high, which is undesirable. On the other hand, if it exceeds 10, the performance and yield of the resulting modified phenol resin varnish will hardly change, so it is considered wasteful to use more formaldehyde polymer. Here, the mixing ratio of petroleum heavy oil or pitch to formaldehyde polymer is preferably 2 to 8.

[0013] As the acid catalyst used in producing the above-mentioned modified phenolic resin, a Brønsted acid or a Lewis acid can be used, but a Brønsted acid is preferably used. As the Bronsted acid, toluenesulfonic acid, xylenesulfonic acid, hydrochloric acid, sulfuric acid, formic acid, etc. can be used, but p-toluenesulfonic acid and hydrochloric acid are particularly excellent. The amount of acid catalyst used is 0.1 based on the total amount of petroleum heavy oil or pitch and formaldehyde polymer.
-30% by weight, preferably 1-10% by weight. When the amount of the acid catalyst used is small, the reaction time tends to be long, and the reaction tends to be insufficient unless the reaction temperature is raised. On the other hand, even if the amount of acid catalyst used increases, the reaction rate does not increase accordingly, which may be disadvantageous in terms of cost. Additionally, recovery and neutralization of the acid catalyst may be required, which may incur extra costs.

The phenols used in the method of the present invention are preferably one or more phenolic compounds selected from the group of phenol, cresol, xylenol, and resorcinol. In producing the above-mentioned modified phenolic resin, phenols are added little by little and mixed by a method such as dropping. The rate of addition is from 0.05 to 5% by weight/min, preferably from 0.1 to 2% by weight/min, based on the total weight of the reaction mixture. Adding speed is 0
．． If it is less than 0.05% by weight/min, the time required for addition is too long and the cost increases, which is not preferable. On the other hand, if the addition rate exceeds 5% by weight/min, the added phenol reacts rapidly with free formaldehyde, making it difficult to form a homogeneous mixture or cocondensate, which is not preferred. The reason for this non-uniformity is
This is because the reactivity of phenols to formaldehyde is significantly greater than that of heavy petroleum oils or pitches, and unless the initial concentration of phenols is kept low,
It is speculated that this is because formaldehyde selectively reacts with phenols or a condensate of phenols and formaldehyde produced by the reaction, making them poorly soluble in the system. Alternatively, formaldehyde may be consumed first in the reaction between phenols or a condensate of phenols and formaldehyde produced by the reaction, resulting in heavy petroleum oils or pitch or heavy petroleum oils produced by the reaction. Alternatively, it is speculated that the condensate of pitches and formaldehyde cannot further react with formaldehyde and is separated from the reaction system.

In the above operation, the timing to start adding phenols is not particularly limited, but when the reaction rate of formaldehyde estimated from the amount of remaining free formaldehyde is 70% or less, preferably 50% or less, phenols are added. Add. The addition may be started at a time when the reaction between heavy petroleum oils or pitches and formaldehyde has not substantially progressed. If the reaction rate with formaldehyde exceeds 70%, the amount of formaldehyde that reacts with phenols will decrease, resulting in a significant decrease in the performance of the resulting resin, and in extreme cases, it will not cure unless a curing agent is added, so this is not preferred. do not have.

The amount of phenols added is from 0.3 to 1 mole of phenol per 1 mole of the average mole calculated from the average molecular weight of petroleum heavy oil or pitch.
It is 5. If the amount added is less than 0.3, the reactivity between heavy petroleum oils or pitches and formaldehyde is inferior to the reactivity between phenols and formaldehyde, and therefore sufficient crosslinking density cannot be achieved. However, there is a problem that the strength after curing is lower than that of general phenolic resins. In particular, it has low impact resistance and is brittle. On the other hand, if the amount of phenol added exceeds 5, the modification effect due to modification of the phenol resin will be small, which is not preferable. The amount of this phenol added is preferably 0.5 to 3.

[0017] The reaction temperature is 50 to 160°C, preferably 60 to 120°C. This reaction temperature may be determined in consideration of the raw material composition, reaction time, properties of the resin to be produced, and the like. The reaction time is 0.5 to 10 hours, preferably 1 to 5 hours.
It's time. The reaction time is determined in consideration of the raw material composition, reaction temperature, addition rate of phenols, properties of the resin produced, etc. When the above reaction is carried out batchwise, it can be carried out in one step, and is preferably carried out in one step. In addition, when performing in a continuous manner, there is no need to use difficult-to-control equipment that continuously mixes two or more reaction products in fixed amounts, which is used in conventional modified phenolic resins. A mixing type reaction vessel may be placed and the phenols to be added may be fed into the vessel in fixed amounts. Such devices are relatively inexpensive and easy to operate.

A solvent can be used during the above-mentioned reaction. Although the reaction can be carried out without a solvent, the use of a solvent reduces the viscosity of the reaction system and improves the uniformity of the reaction. However, the solvent must be removed before curing, which generally increases costs, except for special cases. Examples of solvents include, but are not limited to, aromatic hydrocarbons such as benzene, toluene, and xylene, halogenated aromatic hydrocarbons such as chlorobenzene and dichlorobenzene, nitrated aromatic hydrocarbons such as nitrobenzene, and nitroethane. , nitrated aliphatic hydrocarbons such as nitropropane, halogenated aliphatic hydrocarbons such as perchlorene, trichlene, carbon tetrachloride, etc. can be used.

In the method of the present invention, a varnish is prepared by using a modified phenol resin obtained by the above-described operation and dissolving it in an organic solvent. The organic solvent used here is not particularly limited as long as it can dissolve as many components as possible in the modified phenol resin as soluble components. Usually, aromatic hydrocarbons such as toluene and xylene, ethers such as tetrahydrofuran and dioxane, alcohols such as methanol and ethanol, glycols such as ethyl cellosolve, ketones such as acetone and methyl ethyl ketone, and acetic acid. Examples include esters such as ethyl, chloroform, methylene chloride, perchlorene, halogenated aromatic hydrocarbons (such as chlorobenzene), or mixtures thereof. One of these days,
Toluene and chloroform are particularly preferred.

[0020] When dissolving the above-mentioned modified phenolic resin in these organic solvents, the operation and conditions may be appropriately selected depending on the type of organic solvent used, the type of modified phenolic resin, etc. Usually, the above-mentioned modified phenol resin may be added to an organic solvent at a ratio of 10 to 50% solution at room temperature or under heating, and stirred for about 10 minutes to 1 hour. Next, components insoluble in the organic solvent are removed by filtration, if necessary, to obtain a solution of the modified phenol resin in an organic solvent (for example, a chloroform solution) as a varnish. Note that it is also effective to further wash this organic solvent solution with water to remove dissolved water-soluble components such as the acid catalyst.

[0021] In the method of the present invention, the varnish thus obtained is impregnated into a laminated base material either as it is or after being appropriately concentrated. Here, various materials can be used as the laminated base material, such as glass cloth, glass fiber nonwoven fabric, paper (kraft paper, linter paper, etc.), cloth, or fiber structure such as carbon fiber cloth or carbon fiber nonwoven fabric. Glass cloth is particularly preferred. The amount of impregnation is not particularly limited and may be selected depending on the situation, but generally the amount of impregnated dry resin is 10 to 50% by weight, preferably 1% by weight, based on the resin-impregnated laminated base material.
It ranges from 5 to 40% by weight. After the laminated base material is impregnated with varnish in this manner, it is dried to remove the used organic solvent, and if necessary, a portion of the impregnated modified phenolic resin is cured.

In the method of the present invention, after drying as described above, the obtained prepreg is dried in a predetermined number (for example, 5 to 5 sheets).
(about 30 sheets) are stacked and formed. There are various methods for molding at this time, but usually a predetermined number of prepreg sheets are stacked at a temperature of 150 to 300°C and a pressure of 10 to 200 kg/cm.
The molding may be carried out under heat and pressure for about 10 minutes to 3 hours under the conditions of 2. Then, during this laminated molding, if necessary, metal foil such as copper, nickel, aluminum, chromium, etc. is placed on one or both sides of the prepreg and hot-press molded, making it suitable for use as electrical and electronic materials. laminates can be obtained.

[0023]

EXAMPLES Next, the present invention will be explained in more detail and concretely by way of examples. These do not limit the invention. Table 1 shows the properties of raw material oil I and raw material II used in the following examples. These feedstock oils are obtained by distilling the bottom oil of a fluid catalytic cracker (FCC) for vacuum gas oil.

[0024]

[Table 1]

Example 1 696 g of raw oil I shown in Table 1, 538 g of paraformaldehyde, p-toluenesulfonic acid (monohydrate) 1
A glass reactor was charged with 340 g of p-xylene and 340 g of p-xylene, and the temperature was raised to 98° C. with stirring. When the temperature reached 98°C, 240 g of phenol was added dropwise at a rate of 3 cc/min.
The reaction mixture was stirred for a minute. After the reaction is complete, the reaction mixture is
000 g of n-hexane to precipitate the reaction product. The precipitate was filtered, washed, and dried under reduced pressure at 25°C to obtain 1250 g of modified phenol resin. 800 g of toluene was added to 100 g of the obtained modified phenol resin, and after stirring for 30 minutes, toluene insoluble matter (about 20% by weight based on the total amount of resin) was removed by filtration. The obtained toluene solution was concentrated to obtain a varnish with a resin content of 50% by weight. Apply this varnish to glass cloth (plain weave, H201SD105)
B. (manufactured by Unitika U.M. Glass) was impregnated, dried, and further heat-treated at 245° C. for 10 minutes to obtain a prepreg in which a portion of the impregnated resin was cured. The obtained 20 sheets of prepreg were stacked alternately and heated at 250°C and 30kgf/
cm2 for 60 minutes to obtain a modified phenol resin laminate having a resin content of 27%. Its characteristics are shown in Table 2.

Example 2 500 g of raw oil I shown in Table 1, 408 g of paraformaldehyde, p-toluenesulfonic acid (monohydrate) 6
1 g of o-dichlorobenzene and 640 g of o-dichlorobenzene were charged into a glass reactor, and the temperature was raised to 95°C while stirring. 9
When the temperature reached 5℃, add 311g of phenol to 4cc/
After the dropwise addition of phenol was completed, the mixture was stirred for an additional 15 minutes to react. After the reaction was completed, the reaction mixture was poured into 4000 g of n-hexane to precipitate the reaction product. The precipitate was filtered, washed, and dried under reduced pressure at 25°C to obtain 900 g of modified phenol resin. Add 500 g of chloroform to 100 g of the obtained modified phenol resin.
After stirring for 30 minutes, chloroform-insoluble matter (about 15% by weight based on the total amount of resin) was removed by filtration. The resulting chloroform solution was washed with water to remove the residual acid catalyst, and then concentrated to obtain a varnish with a resin content of 33% by weight. A glass cloth (satin weave, S525E103, manufactured by Unitika U.M. Glass) was impregnated with this varnish, dried, and further heat-treated at 225° C. for 10 minutes to obtain a prepreg in which a portion of the resin was cured. Eighteen sheets of the obtained prepreg were stacked and heated and pressure molded at 250° C. and 75 kgf /cm 2 for 60 minutes to obtain a modified phenol resin laminate with a resin content of 22%. Its characteristics are shown in Table 2.

Example 3 135 g of raw oil I shown in Table 1, 110 g of paraformaldehyde, 1 p-toluenesulfonic acid (monohydrate)
6.5 g and 220 g of o-dichlorobenzene were charged into a glass reactor, and the temperature was raised to 95°C while stirring. When the temperature reached 95℃, add 1 cc of 84 g of phenol.
The mixture was added dropwise at a rate of 1/min, and after the addition of phenol was completed, the mixture was stirred for an additional 15 minutes to react. After the reaction was completed, the reaction mixture was poured into 1000 g of n-hexane to precipitate the reaction product. The precipitate was filtered, washed, and dried under reduced pressure at 25°C to obtain 250 g of modified phenol resin. Add 50 g of chloroform to 100 g of the obtained modified phenol resin.
After adding 0 g of the resin and stirring for 30 minutes, the chloroform-insoluble content (approximately 15% by weight based on the total amount of resin) was removed by filtration. The resulting chloroform solution was washed with water to remove the residual acid catalyst, and then concentrated to obtain a varnish with a resin content of 33% by weight. Apply this varnish to glass cloth (ECM208UM 661-
1040, manufactured by Unitika Um Glass),
A prepreg was obtained by drying. Twenty sheets of the obtained prepreg were stacked and heated and pressure molded at 270° C. and 25 kgf /cm 2 for 30 minutes to obtain a modified phenolic resin laminate with a resin content of 25%. Its characteristics are shown in Table 2.

Example 4 The modified phenol resin obtained in Example 3 was dissolved in chloroform and treated in the same manner to obtain a varnish with a resin content of 55% by weight. Next, impregnate the glass cloth with this varnish,
It was dried and further heat-treated at 170° C. for 30 minutes to obtain a prepreg in which the impregnated modified phenol resin was partially cured. The 13 sheets of prepreg obtained were stacked and heated at 250°C, 7
The product was heated and press-molded at 5 kgf/cm2 for 60 minutes to obtain a modified phenol resin laminate having a resin content of 53% by weight. Its characteristics are shown in Table 2.

Example 5 150 g of raw material II shown in Table 1, 97 g of paraformaldehyde, 1 p-toluenesulfonic acid (monohydrate)
6.4 g and 200 g of o-dichlorobenzene were placed in a glass reactor, and the temperature was raised to 95°C while stirring. When the temperature reached 95℃, add 81g of phenol to 1cc/
After the dropwise addition of phenol was completed, the mixture was stirred for an additional 15 minutes to react. After the reaction was completed, the reaction mixture was poured into 1000 g of n-hexane to precipitate the reaction product. The precipitate was filtered, washed, and dried under reduced pressure at 25°C to obtain 222 g of modified phenol resin. Add 500 g of chloroform to 100 g of the obtained modified phenol resin,
After stirring for a minute, chloroform-insoluble matter (about 25% by weight based on the total amount of resin) was removed by filtration. The obtained chloroform solution was concentrated to obtain a varnish with a resin content of 40% by weight. A carbon fiber cloth was impregnated with this varnish and dried to obtain a prepreg. Stack the 10 sheets of prepreg obtained and
The product was heated and press-molded at 80° C. and 20 kgf /cm 2 for 60 minutes to obtain a modified phenol resin laminate having a resin content of 35% by weight. Its characteristics are shown in Table 2.

[0030]

[Table 2]

[0031]

[Effects of the Invention] As described above, according to the method of the present invention,
A phenolic resin laminate with well-balanced improvements in comprehensive physical properties such as electrical insulation, heat resistance, mechanical strength, and water resistance can be obtained. In particular, the resin laminate produced by the method of the present invention has significantly improved heat resistance compared to conventional phenolic resin laminates. Therefore, the resin laminate produced by the method of the present invention is expected to be widely and effectively used in various fields that require electrical insulation, heat resistance, and mechanical strength, including insulating members for electrical and electronic products. be done.

Claims (5)

[Claims] Claim 1: Aromatic hydrocarbon fraction fa value is 0.40 to 0.
．． 95.Formaldehyde polymer is added to 1 mole of petroleum heavy oil or pitch having an aromatic ring hydrogen content Ha value of 20 to 80%.
10, and while heating and stirring in the presence of an acid catalyst, the phenols are added to 0 based on the total weight of the petroleum heavy oil or pitch and the formaldehyde polymer.
．． The phenol is added at an addition rate of 0.05 to 5% by weight/min, and the number of moles of phenol added per mole of the petroleum heavy oil or pitch is 0.3 to 5. It is characterized by dissolving a modified phenolic resin obtained by polycondensation in an organic solvent to obtain a varnish, then impregnating a laminated base material with the varnish and drying it, and then laminating and molding the obtained prepreg. A method for producing a modified phenolic resin laminate. 2. The method according to claim 1, wherein the organic solvent is at least one solvent selected from chloroform, methylene chloride, aromatic hydrocarbons, and halogenated aromatic hydrocarbons. 3. The production method according to claim 2, wherein the aromatic hydrocarbon is at least one compound selected from benzene, toluene and xylene. 4. The manufacturing method according to claim 1, wherein the laminated base material is glass cloth, glass fiber nonwoven fabric, paper, cloth, carbon fiber cloth, or carbon fiber nonwoven fabric. 5. The manufacturing method according to claim 1, further comprising curing a portion of the modified phenolic resin impregnated into the laminated base material after drying and prior to lamination molding.