JPH01236262A - Thermosetting phenol resin composition - Google Patents

Abstract

PURPOSE:To obtain the title resin composition improved in peeling strength, adhesiveness and low-smoking property, by dissolving a specified thermosetting phenol resin, a polyglycol epoxy resin and an acrylonitrile/butadiene rubber in an organic solvent. CONSTITUTION:An HCl/HCHO bath of an HCl concentration of 5-28wt.%, an HCHO concentration of 3-25wt.% and a total concentration of HCl and HCHO of 15-40wt.% is brought into contact with a phenol under conditions of a bath ratio of formula I >=8 and a molar ratio of formula II of 2-20 to obtain a thermosetting phenol resin (A) of a weight-average MW in terms of PS (gel permeation chromatography) >=1,000 and a free phenol content (liquid chromatography) <=500ppm. Component A is mixed with polyglycol epoxy resin (B) of formula III (wherein R is H or CH3, and n is 2-10), an acrylonitrile/ butadiene rubber terpolymer (C) containing a carboxylic component and an organic solvent (D) (e.g., methanol) in a weight ratio of A to (B+C) of 50/50-95/5, a weight ratio of (A+B+C) to D of 5/95-80/20 and a weight ratio of A to (B+C) of 50/50-90/10.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a thermosetting phenolic resin composition that has excellent adhesiveness and processability, and more particularly, is flame retardant and The present invention relates to a thermosetting phenolic S-finger composition suitable for manufacturing structural materials having good smoke generation properties, particularly interior materials for aircraft, vehicles, ships, etc.

(Prior Art) In recent years, honeycomb sandwich panels are mainly used as structural materials for aircraft because they are lightweight, have excellent strength, and are suitable for various purposes.

A honeycomb sandwich panel is a molded body made by layering surface materials on both sides of a honeycomb and applying heat and pressure.
Generally, the honeycomb core is made of aluminum or Nomex (manufactured by DuPont, aromatic polyamide nonwoven fabric), and the surface material is aluminum or pongee reinforced plastic.

In particular, aircraft interior panels often use plastic surface materials reinforced with Nomex honeycomb, glass fiber, Kepler, and carbon fiber.

Conventionally, fibers of these reinforcing materials were impregnated with epoxy resin as a matrix resin to form a prepreg, and honeycombs were pressurized and heated to form honeycomb sandwich panels. However, in order to ensure the safety of passengers in the event of a fire, it is becoming regulated by law to use materials that are flame retardant and have low smoke emission for the interior materials of modern aircraft. materials are needed.

Phenolic ring fingers are one of the leading candidates for this material.

However, although phenolic resin is flame retardant and has low smoke emission,
When used as a surface material for honeycomb panels, one drawback was that the peel strength was low.

In addition, ordinary phenolic resins, that is, resol resins, contain a large amount of free phenol, which is an unreacted monomer, and have a low molecular weight. There are many problems in terms of work, such as the need for one festival.

(Problems to be Solved by the Invention) In view of the above-mentioned problems of the prior art, the present inventors continued intensive research and found that specific thermosetting phenolic resins, epoxy resins and acrylonitrile-butadiene rubber (hereinafter referred to as NBR) When combined with a conventional thermosetting phenolic resin and an epoxy resin and an NB layer, the adhesion is improved and the smoke-emitting property is good, making it a flexible prepreg. The present invention was completed based on the discovery that manufacturing is possible.

An object of the present invention is to provide a thermosetting phenolic resin composition for manufacturing honeycomb sandwich panels that has good peel strength and low plasticity.

It is a further object of the present invention to provide a thermosetting phenolic resin composition for producing flexible prepregs suitable for honeycomb sandwich panel applications.

Still another object of the present invention is to provide a thermosetting phenolic resin composition that has good workability during prepreg production.

Further objects and advantages will become apparent from the description below.

(Means for Solving the Problems) The above objects of the present invention are as follows: (A) The average molecular weight in terms of polystyrene is 1000 or more as measured by GPC ('7' rubber minision chromatography), and , (B) A thermosetting phenolic resin with a free phenol content of 500 pI)m or less as measured by U-body chromatography (a) and a polyglycol type epoxy resin (b) 3 having a carboxylic component The original copolymer acrylonitrile-butadiene rubber (hereinafter abbreviated as "JNB")? → and an organic solvent), whose composition ratio is (a) / [(b) + n →] = 50 / 50
~95/5, [(a) + (b) + (c)] 7/naka → = 5
/95 ~8 0 / 2 0> f mouth)/(
C)=50/5 C1~90/10'T!
This is achieved by using a thermosetting phenolic resin composition that has excellent adhesion and low smoke emission.

The thermosetting phenolic resin used in the present invention is produced from formalin and phenols.
Particulate phenolic resin) is preferred.

The above-mentioned "granular phenolic resin" is manufactured by the following method.

(1) The following composition, (a) 5 to 28% by weight of 1 degree hydrochloric acid (Hal), (b)
Formaldehyde (HCHO) has a quality of 3 to 25% by weight, and (c) a total hardness of hydrochloric acid and formaldehyde of 15 to 4.
Using a hydrochloric acid-formaldehyde bath having a concentration of 0% by weight, (2) the following formula (3), ... Phenols are brought into contact with a hydrochloric acid-formaldehyde bath.

In addition to the eight conditions (a), (b), and (c) above, the composition of the hydrochloric acid-formaldehyde bath in (1) above is such that the following conditions are satisfied: at least 2, especially 2.5 or more , especially preferably 8 or more. The upper limit of the molar ratio (under the above conditions) is not particularly limited, but it is preferably 20 or less, especially 15 or less, and increasing the molar ratio more than this is not economically viable; When it is less than 2.5, especially less than 2, the reaction rate decreases and it becomes difficult to obtain uniform and fine granular or powdery fat. A particularly preferred range of the above molar ratio is 4-15. Setting the molar ratio to 2 or more, especially 2.5 or more is effective for beads when the bath ratio (2) is relatively low, for example, when the bath ratio is 8 to 10.

A hydrochloric acid-formaldehyde bath having the bath composition of (1) above is used at a bath ratio of 8 or more, preferably 10 to the weight of the phenol.
The phenols are brought into contact with each other while maintaining the following conditions. An important feature of the present invention is that hydrochloric acid (HCl) is
) A bath of a hydrochloric acid-formaldehyde aqueous solution having a fairly high i* degree of 1 degree and containing an excess of formaldehyde relative to the phenols is brought into contact with the phenols at a bath ratio of 8 or more, preferably 10 or more. It's about letting people know.

Such phenol-formaldehyde reaction conditions are as described above, the conventionally known novolac reaction conditions. The reaction conditions for i tiR and resol resin production are fundamentally different.

Hydrochloric acid ([01) 5 degrees in a hydrochloric acid-formaldehyde bath is 10
The formaldehyde (HCHO) concentration of the bath is preferably 5 to 20% by weight, especially 7 to 15% by weight, and The total concentration of hydrochloric acid and formaldehyde is 20-85% by weight,
26-32% by weight is suitable for beads.

When the hydrochloric acid-formaldehyde bath and phenols are brought into contact, the bath ratio expressed by the above formula (expressed in Shu) is 10 or more, especially 1
It is preferable to set it as 5-40.

When phenols are brought into contact with the hydrochloric acid-formaldehyde bath described above, and after the phenols come into contact with the bath, white slag is formed, and when walking at night, pink granular or powdery solids are produced. Do so as to form. and,
During this contact, the temperature within the reaction system is maintained at a temperature below 45°C. The contact between the hydrochloric acid-formaldehyde bath and the phenol causes the addition of the phenol into the hydrochloric acid-formaldehyde bath to first form a clear solution, then a white cloudiness, and then a pink granule or powder when walked at night. It is preferable to carry out the process in such a way that a solid substance having a shape of 1.5 mm is formed.

At this time, before adding phenols to the bath to create a white cloud, the bath is stirred so that the added phenols and the bath form a transparent solution as uniform as possible, and It is preferable not to apply any mechanical shearing force, such as stirring, to the bath (reaction liquid) during the period from the time when spores are formed until the pale pink solid is formed.

The phenol to be added may be the phenol itself, but it is preferable to dilute the phenol with formalin, an aqueous hydrochloric acid solution, water, or the like. Particularly preferably, it is used after being diluted with water.

In particular, phenols are diluted with a formalin solution containing 8 to 44% formaldehyde, preferably 20 to 40% by weight, so that the phenol concentration is 50 to 95% by weight, especially 70 to 90% by weight. It is preferable to use a diluted solution of . However, in this case, the bath composition after adding this diluted phenol solution to the hydrochloric acid-formaldehyde bath is the above-mentioned (a), (b), G/, preferably the above-mentioned (a), (
It is necessary to control so as to satisfy the conditions (b), (c), and (b).

Furthermore, the temperature of the hydrochloric acid-formaldehyde bath when adding phenols (or its diluted solution) is 40°C or less, preferably 5 to 85°C, and preferably 10 to 30°C.
It is. If the temperature of the bath exceeds 4o''C, the rate of reaction between phenols and formaldehyde will change significantly, so the highly reactive granular or powdered resin of the present invention with a methanol dissolution rate of 2Ofltffi% or more, as defined later. becomes difficult to manufacture.

Phenol is most suitable as the phenol to be used, but 0-cresol, m
-Rinisol, p-cresol, bis-phenol A1
0-lm- or p-C2-C4 alkylphenol, p
- It may be a mixture with one or more known phenol derivatives such as phenylphenol, xylenol, and resorcinol.

The granular or powdery phenol-formaldehyde solids produced in the bath as described above and on which the desired reaction has been completed are separated from the hydrochloric acid-formaldehyde bath, washed with water, and preferably It can be purified by neutralizing hydrochloric acid with an aqueous alkaline solution and washing with water.

As the aqueous alkali solution, for example, an aqueous alkali metal solution, particularly an aqueous ammonia solution is preferable. The agricultural content of ammonia is suitably 0.1 to 5% by weight, particularly -0.8 to 8% by weight. Neutralization with the alkaline aqueous solution at 50°C
Hereinafter, it is advantageous to carry out preferably at a temperature of 10 to 40°C.

The granular or powdered solid material that has been subjected to the water washing treatment or subsequent neutralization and water washing treatment may be dehydrated and used as it is for the final use, or it may be processed in a conventional manner at a temperature lower than the heat fusion temperature, e.g. After drying at 40-50°C, it can be used for final use.

Moreover, before or after drying, the product can be made into a product by being lightly pulverized using an arbitrary pulverizer.

The "granular phenol H fat" obtained by the above method is
Preferred products have a free phenol content of less than 500 pI)m as determined by liquid chromatography, and preferred products have a free phenol content of less than 400 ppm, especially less than so o ppm.

The reason why the free phenol content is so small is that, as mentioned in the above production method, phenols or diluted solutions thereof are added to a hydrochloric acid-formaldehyde bath to form an at least partially homogeneous solution. In order to generate extremely small particles and grow them into stable pink particles, substantially all of the added phenols, especially the phenols involved in the formation of the product of the present invention, are This is thought to be due to reaction with formaldehyde.

The free phenol content of the granular or powdered products suitable for the invention is low, and this fact is an important advantage for such granular or powdered products.

Furthermore, the four fingers constituting the granular or powdered product of the present invention are:
→In the 1,000-infrared absorption spectrum, D999-1015/DI600″0.2-9.〇-D
It has a characteristic of 890/Dteoo=0.09 to 1.0.

Also, preferred products of the present invention are:

D99o Dxots / D, 16QO is g, 2ゞ5
．． 〇-Waiting is 0.3-4.0, D890-/D1600 is 0.1-0.9, Samurai is 0.1
It has a characteristic of 2 to 0.8.

In the infrared absorption spectrum, the peak at D1600 indicates absorption attributed to the benzene nucleus, and the peak at D990 to 1016
It is already widely known with respect to phenol-formaldehyde that the peak D890 shows an absorption S attributed to the methylol group, and the peak D890 shows an absorption attributed to the isolated hydrogen atom of the benzene nucleus.

The product of the present invention is 0990-1015 / Dtsoo =
The characteristic values of 0.2 to 9.0 indicate that the products of the invention contain at least a moderate amount of methylol groups and that the methylol group content can be adjusted within a fairly wide range. . Especially D990-1016 = 0.2-5.
Preferred products of the invention, with a concentration of 0.0, especially 0.3 to 4.0, contain moderate, Laco-modified methylol groups and are more stable.

Furthermore, D in the infrared absorption spectrum of the product of the present invention
890/D1600 = 0-09~1.0, more suitable product is D890/D1600 = 0.1~0.9
The fact that the product of the present invention exhibits a characteristic of 0.12 to 0.8, in particular, indicates that the reaction 8Q1 (ortho and baro positions) of the phenol molecules involved in the reaction are moderately blocked by the methylo product. Indicate the fact that

Cured products of conventionally known resol resins generally have a D990 to
Both or one of 1015/D1600 and D890/D1600 is lower than the lower limit of the above characteristic value of the product of the present invention, and the characteristic value of 0890/D1600 of the novolac resin cured with hexamine is also lower than the lower limit of the characteristic value of the product of the present invention. This value is generally lower than the lower limit of 0.09.

Furthermore, the granular or powdered resin product of the present invention preferably has a methanol solubility of 20% by weight or more, preferably a methanol solubility of 80% by weight or more, particularly 40% by weight or more. . This characteristic indicates the fact that the product of the present invention contains a condensate with a relatively low molecular weight that is soluble in methanol, but as measured by G, P, and C, it is lower than that of conventional resol resins and novolak resins. Although the weight average molecular weight in terms of polystyrene is usually small, 100 to 600, and contains a large amount of free phenol, the above-mentioned granular or powdered resin has a large weight average molecular weight of 1000 or more, and when applied to the present invention, favorable results can be obtained.

The polyglycol-type epoxy resin used in the present invention has polyalkylene oxide components and is epoxidized at both ends, and preferred examples include those represented by the following general formula.

R=H or CH8 The viscosity of the epoxy resin represented by the above general formula increases as n increases, and usually those with n = 2 to 10 are used. In the present invention, the epoxy resin represented by the above general formula is a polyglycol type Favorable results can be obtained by using a material containing 50% or more of epoxy resin. However, if a bisphenol A type material is used instead of a polyglycol type material, the adhesiveness and smoke generation properties may not be sufficiently exhibited, but the flexibility of the prepreg may be insufficient.

NBR, which is a terpolymer having a carboxylic component used in the present invention, means a product obtained by copolymerizing ordinary NBR rubber with (meth)acrylic acid or the like. The ratio of carboxylic components is not particularly limited, but is usually 0.0.
1 to 0.1 eq/g is used.

The organic solvent used in the present invention is preferably a polar solvent that dissolves thermosetting phenol, polyglycol type epoxy resin, and NBR components, but is not limited to this, and some A non-dissolving solvent may be mixed.

Examples of polar solvents applicable to the present invention include alcohols,
Examples include ethers, esters, ketones, amides, or mixed solvents of two or more thereof, but preferably methanol, ethanol, propatool, butanol,
Acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl cellosolve, ethyl cellosolve, tetrahydrofuran, ethyl calpitol, butyl calpitol,
Ethyl acetate, ethyl carpitol acetate, butyl carpitol acetate, DMF.

DMSO or a mixed solvent of two or more thereof is suitable. Among these, methanol, ethanol, acetone, methyl ethyl ketone, tetrahydrofuran, methyl cellosolve, and acetate ester of ethyl calpitol are usually used in terms of ease of handling and solubility.

An important point in the present invention is the blending ratio of the composition of the present invention.

The higher the proportion of phenolic resins, the better the release properties will be, but the adhesiveness and flexibility will be worse. Therefore, the composition ratio is usually phenolic resin/polyglycol type epoxy and NBR component = 50,150 to 95 by weight.
15, preferably 70/80 to 90/l O.

In addition, the composition ratio of polyglycol type epoxy resin and NB15 is the weight ratio of polyglycol type epoxy PJ finger/NB.
R component = 50150-90/10, particularly preferably 60/40-80/20.

The more the NBR component is added, the better the adhesion is, but the smoke generation properties are worse, and in the process of impregnating glass floss with the composition, there are more impregnation spots, making it impossible to obtain a uniform prepreg. The present inventors have arrived at the present invention by finding the optimum composition ratio of the composition.

If the organic solvent component in the composition of the present invention is too large, the amount of resin deposited in the impregnation step will be reduced. Although the desired coating weight can be obtained by repeating impregnation, it is complicated and not economical. Moreover, if the organic solvent component is small, problems arise such as impregnation in the impregnation step becoming difficult. Therefore, usually resin component/organic solvent = 5/95 to 80/20, preferably 2
It is 0/80 to 60/40.

The composition of the present invention can be manufactured by blending the components constituting the composition.

That is, the resin constituting the composition is dissolved in an organic solvent.

The dissolution may be carried out with or without heating, but in order to maintain the stability of the composition, it is carried out at room temperature without heating.

Alternatively, stirring may be performed using a homodisper, homogenizer, or the like. The components may be dissolved simultaneously or individually.

When "granular phenol resin" is used as the phenol resin constituting the composition, un-tS-decomposed components are present in the solvent, but it may be selected as necessary whether to filter them or use them without any separation.

Carboxylic NBA, which is a terpolymer of rubber components constituting the composition, reacts with the epoxy resin, which is the other T33 component of the composition, and has a stronger adhesive effect.

The composition of the present invention may be blended immediately before using the composition, for example, immediately before manufacturing a prepreg for impregnating glass cloth, but it may also be blended and stored in advance. In particular, when a "granular phenol resin" is used as the heat-curable phenol resin of the present invention, it has good storage stability and is advantageous for blending into the composition.

After a glass cloth is impregnated with the composition of the present invention, it can be dried to form a prepreg.

This prepreg is laminated with, for example, a Nomex split honeycomb core and then heated under pressure to form a honeycomb sandwich panel.

In particular, the gelling time of prepreg is long (and it is flexible even with a small amount of volatile components, so the advantages are greater, such as easier molding operations.

The drum peel strength of this honeycomb sandwich panel is much superior to that of panels made solely from phenolic resin. It is also considerably superior to ordinary phenol laryngose/epoxy resin/NB combination products.

Furthermore, the flame release properties are comparable to those of phenolic resin alone, resulting in a panel with low smoke generation.

(Effect of the invention) The thermosetting phenolic resin composition obtained by the present invention is
When a prepreg is prepared by impregnating glass cloth or the like, a flexible prepreg can be obtained even with a low volatile content. Therefore, when adhesively bonded to a honeycomb core and press-molded, the honeycomb panel is easy to load into a molding machine and perform gas purification, and has self-extinguishing properties, low smoke emission, and excellent adhesive strength.

Such honeycomb sandwich panels are used as interior materials for aircraft, as well as transportation equipment for ships and vehicles, and interior materials for buildings.

In addition, this composition can be used for applications other than those mentioned above, such as laminated I-boards as a festival board with good workability, and is very useful.

Examples will be described below.

The measurements in the examples were carried out in the following manner: A T, H, F (tetrahydrofuran) solution was prepared and filtered using a 0.45μ membrane filter. The filtered filtrate was measured using G, P, C (gel perminisicon chromatography), and calculated from the polystyrene calibration curve.

2. Measure the solution sample whose viscosity was adjusted to 25°C using a B-type viscometer.

8. Gel time Measured by the LP method at a temperature of 150°C.

4. Pass through a 100 Tyler mesh sieve] After thoroughly kneading the dry sample with your hands if necessary, accurately weigh about 10 pieces of it, and pass through a 100 Tyler mesh sieve in small portions over 5 minutes. Dimensions: 200mmφ
, Shaking conditions: 200 R11) and shaken for 10 minutes after adding the sample.

The amount of passage through the 100 Tyler mesh is calculated using the following formula.

ω0 ω0: Input amount (g) ω1: Amount remaining in the final layer without passing through the 100 Tyler mesh 5. Determination of free phenol content: Precisely weigh 10 f of the sample that passed through the 100 Tyler mesh.
Heat treatment in 190 g of 100% methanol for 80 minutes under reflux. The P solution passed through a glass filter (No. 3) was subjected to high performance liquid chromatography (6000A manufactured by Waters, USA) to quantify the phenol content in the P solution, and the free phenol content in the sample was determined from a separately prepared calibration curve. The content was determined.

The operating conditions for high performance liquid chromatography are as follows.

Packaging: 6000A column carrier manufactured by Waters, USA:
u-Bondapak C14 column: 1/4 inch diameter x 1 foot length Column temperature: room temperature Eluent: methanol/water (3/7, volume ratio) Flow rate:
Q, 5ml/min detector 20V (254nm), BangeO
, 01 (1 mV) The phenol content in the F solution was determined from a previously prepared calibration curve (relationship between phenol content and peak height based on phenol).

6. Instructions for measuring infrared absorption spectra and how to determine absorption intensity Infrared spectrophotometer (Model 226) manufactured by Hitachi, Ltd.
The infrared absorption spectrum was measured for a measurement sample prepared by the usual KBr tablet method.

The absorption intensity at a specific wavelength was determined as follows. In the measured infrared absorption spectrum diagram, draw a baseline at the peak whose absorption intensity is to be determined. If the transmittance at the top of the peak is expressed as tp, and the baseline transmittance at that wavelength is expressed as tb, then the absorption intensity at that specific wavelength is given by the following formula.

[p Therefore, for example, the ratio of the absorption intensity of the peak at 899 cm l and the absorption intensity of the peak at 1600 cm is the ratio of the respective absorption intensities calculated using the above formula (D890/D16
00 ).

7. A 5 g sample passed through a heat-sealable 100 Tyler mesh at 100°C for 30 minutes was transferred to two 0.5 g samples.
Prepare the one inserted between 2 mm thick stainless steel plates,
This was heated to 100°C in advance using a heat press machine (manufactured by Shikamifuji Metal Industry Co., Ltd., single-acting compression molding machine) for 5 minutes at an initial pressure of 50 k.
Pressed at g. After releasing the press, the hot-pressed sample was taken out from between the two stainless steel plates. If the sample taken out is clearly fixed to form a flat plate due to melting or fusion, it is determined that the sample has fusible properties, and if there is almost no difference between before and after hot pressing, the sample is judged to be It was judged to be infusible.

8. Methanol Solubility (S) Sample No. 101 was accurately weighed (the exact weighed weight is Wo) and heated under reflux for 30 minutes in about 500 ml of substantially anhydrous methanol. Glass filter (No. 3)
), and the filter residue sample was further washed on the filter with about 1001M methanol, and then the filter residue sample was dried at a temperature of 40° C. for 5 hours (the exact weighed weight is Wl).

Methanol solubility was determined using the following formula.

9. Adhesive peel strength Nidram peel method (MIL-8T
Measured using D-401B method).

10. Smoke generation property: Measured by NBS method (ASTM-E-662 non-flame method).

11. Self-extinguishing property: A fire extinguished within 15 seconds after ignition was considered self-extinguishing.

12. NBSDS value: The light transmittance inside the chamber is 'T1
8. Flexibility: Place a 240 x 20 mm piece of prepreg on a horizontal table, hold one end, and heat the other 14. Volatile content nibri preg at 150°C for 15 minutes. Weight difference before and after heating and weight before heating. Example 1 The following "granular phenolic resin" having a molecular weight of 8.200 and a phenol content of 82 ppm, polyglycol type epoxy resin DIR-736 (manufactured by Dow Chemical, epoxy equivalent weight 198 n=1), and nitrile rubber Nipol 1072J (Nippon Zeon acrylonitrile value 27% carboxyl group-containing ternary copolymer) Composition ratio (weight ratio)
Phenol resin/epoxy resin/NBR=8/2/1 was added to methyl ethyl ketone at room temperature using a homodisper.
I had sex and got a festival.

Glass cloth (K8181/A-1100)
After it was impregnated into a fabric (Fa yarn), it was dried in a dryer at 70"C to produce a prepreg with a resin adhesion of 139%.

In addition, as a comparative example, the 4 cheeks of epoxy resin and NBR were changed,
A prepreg was created with the same composition.

Next, these prepregs were pasted on both sides of Nomex W/% Unicam 5AHI8-8.0 (manufactured by Showa Aircraft Industry Co., Ltd.) and heated at 150°C and 2.8k using a heat press.
A honeycomb sandwich panel was produced by molding at g/cm2 for 1 hour.

Drum beer strength of these panels, D by NH3 method
The S value flammability, volatile content and flexibility of the prepreg were as shown in Table 1.

(Left below) It can be seen that by blending specific epoxy components and NBR components, a flexible prepreg can be obtained even with a small amount of volatile components, and the adhesive strength can be greatly improved.

The "granular phenol resin" was manufactured as follows.

"Manufacture of granular phenolic resin" In a 10FF separable flask, mix water containing 18% by weight FFI hydrochloric acid and 7% by weight formaldehyde.
I put OKG. The room temperature was 20'C, but the temperature of the mixed aqueous solution was adjusted to 18°C (aunNal).
was held at While stirring the mixture, a diluted solution prepared by diluting 315 parts of phenol with 85 parts of water was added at once.

After adding the diluted solution, the stirring was stopped for 45 seconds and the machine stood still.
The mixture suddenly became cloudy 68 seconds after the stirring was stopped, and milky white products were observed, and these milky white products gradually turned pink. The liquid temperature gradually rose from the above 18°C (RunNol), reached a peak of 32°C 15 minutes after adding the diluent, and then dropped again. After adding the diluted solution and leaving it for 60 minutes, the mixed aqueous solution of the contents was stirred again for 5 minutes. The solid-liquid separated contents were washed with water using a glass filter, and dissolved in a 0.5% by weight ammonia aqueous solution.
After processing at a temperature of 2°C for 2 hours, it was washed with water and then dehydrated.
It was dried for 8 hours at a temperature of 35°C. The moisture content after drying is 0.
8% by weight, and the q or amount is 87'l f (1unNo
, 1).

Most of the above contents were found to have a particle size of 1 when observed under an optical microscope.
It was a spherical to granular fine powder of ~15 microns, and more than 99% by weight passed through a 100 taylor mesh sieve.

Examples 2 to 6 “A” with a molecular weight of 8,200 and a phenol content of 82 ppm.
Granular phenolic resin, polyglycol type epoxy resin DOW epoxy resin DER7136, and nitrile rubber NIPOL 1072J were dissolved in methyl ethyl ketone while changing the ratio (weight ratio) of the phenolic resin components to obtain a ferret.

A prepreg with a sealant adhesion of 89% was prepared using the same method as in Example 1, and was molded into a Nomex honeycomb and a sandwich panel.

Drum peel strength of these panels, D by NH3 method
The a value, flammability, volatile content and flexibility of the prepreg were as shown in Table 2.

As the epoxy resin and NBR components increase, the drum peel strength improves, but the DS value also tends to increase.

Examples 7 to 10 Same as Example 1, ``granular phenol 1 gosly fat'' and polyglycol type epoxy P! fat dow epoxy resin DER7
86 and nitrile rubber Nipol 1072J were dissolved in methyl ethyl ketone at different ratios (weight ratios) of the rubber components to form a face, and glass cloth was impregnated to prepare a prepreg.

This prepreg and Nomex honeycomb were formed into a honeycomb sandwich panel.

The drum peel strength f, DS value determined by the NBS method, flammability, volatile content and softness of the prepregs were as shown in Table 3.

(Algae white) As the rubber component content increases, the drum peel strength improves, but the DS value also tends to increase.

Example 11 A honeycomb panel was created in exactly the same manner as in Example 1 except that another epoxy resin was used instead of the epoxy resin, and the drum peel strength, ]) S value, flammability, volatile content of prepreg, and flexibility were evaluated. The results of evaluating the properties are shown in Table 4.

(The following is a blank space) ゛-1 Almost the same effect was obtained even if the fjl QTi of the epoxy resin was different.

Claims (1)

[Claims] (1) (A) The polystyrene equivalent weight average molecular weight is 1000 or more as measured by GPC (gel permeation chromatography), and (B) the free phenol content is 500 ppm or less as measured by liquid chromatography. It consists of a thermosetting phenolic resin (a), a polyglycol type epoxy resin (b), a tertiary copolymer acrylonitrile-butadiene rubber having a carboxylic component (c), and an organic solvent (d), and their composition ratios is the weight ratio (a)/
[(B) + (C)] = 50/50 to 95/5, [(B)
+(B)+(C)]/(D)=5/95~80/20,
A thermosetting phenolic resin composition with excellent adhesiveness and low smoke generation, characterized in that (b)/(c) = 50/50 to 90/10.