JPH03210356A - Thermosetting phenolic resin composition - Google Patents

Abstract

PURPOSE:To provide the title compsn. which is flame-retardant and excellent in the flowability and gives a honeycomb sandwich panel with an excellent peeling strength by mixing a thermosetting phenolic resin with an epoxy resin, a rubber component, a modified silicone oil, and an org. solvent. CONSTITUTION:A thermosetting phenolic resin is mixed with an epoxy resin (e.g. a bisphenol A epoxy resin), a rubber component (e.g. a styrene-butadiene rubber), a modified silicone oil (e.g. an epoxidized silicone oil and a carboxylated silicone oil), and an org. solvent (e.g. methanol) to give the title compsn., which is impregnated into a glass cloth, etc., to give a prepreg. A honeycomb sandwich panel made by fixing the prepreg to a honeycomb core is suitably used as an interior or structural material for an airplane, an automobile, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a thermosetting phenolic resin composition with excellent adhesive properties, more specifically, it is flame retardant, has excellent fluidity, and is suitable for use in aircraft, The present invention relates to a thermosetting phenolic resin composition suitable for manufacturing interior materials and structural materials for vehicles, ships, buildings, etc.

(Prior Art) In recent years, honeycomb sand winch panels are mainly used as structural materials for aircraft because they are lightweight and have excellent strength and rigidity.

A honeycomb sand winch panel is a molded product made by layering surface material on both sides of a honeycomb and heating and pressing it.
-a, the honeycomb core is made of aluminum or Nomex (manufactured by Nosex DuPont, aromatic polyamide nonwoven fabric), and the surface material is made of aluminum or fiber-reinforced plastic.

In particular, aircraft interior panels often use Nomex honeycomb and plastic surface materials reinforced with glass fiber, Kevlar fiber, and carbon fiber. Furthermore, in order to ensure the safety of passengers in the event of a fire, flame-retardant materials are required for the interior materials of recent aircraft.

Conventionally, fabrics of these reinforcing materials were impregnated with epoxy resin or phenol resin as a matrix resin to form a prepreg, and the honeycomb was pressurized and heated to form a honeycomb sandwich panel.

However, although epoxy resin has good adhesion, it lacks flame retardancy, and phenol resin, although flame retardance, has low adhesion/separation strength when used as the surface material of honeycomb sandwich panels. There was a drawback.

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, so they have poor R storage stability, and moreover, they generate bad odors during the prepreg manufacturing process. There are many problems in terms of work, such as the need for high-concentration festivals.

For this reason, Japanese Patent Application Laid-Open No. 1-7425, which is filed by the applicant,
No. 4 proposes a thermosetting phenolic resin composition consisting of a thermosetting phenolic resin, an epoxy resin, an organic solvent-soluble rubber component, and an organic solvent, but the above composition has poor fluidity; When used in honeycomb sandwich panels, it is difficult to form fillets, so uneven adhesion tends to occur, and there are quality problems such as areas with high adhesive strength and areas with low adhesive strength.

(The problem that the invention attempts to solve!!l!) The present inventors
In view of the above problems, as a result of intensive research, we found that a thermosetting phenolic resin blended with epoxy resin, rubber components, and modified silicone oil has excellent adhesive properties, flame retardancy, and even fluidity. Discover what's great,
This completes the present invention.

An object of the present invention is to provide a thermosetting phenolic resin composition that has high adhesive peel strength, excellent flame retardancy and fluidity, and is suitable for manufacturing honeycomb sandwich panels.

(Means for Solving the Problems) The above object of the present invention is to provide a thermosetting phenolic resin composition comprising a thermosetting phenolic resin, an epoxy resin, a rubber component, a modified silicone oil, and an organic solvent. achieved by

The thermosetting phenolic resin used in the present invention is produced from formalin and phenols, and includes, for example, resol resin and novolak resin, and is further disclosed in Japanese Patent Publication No. 62-30210 and Japanese Patent Publication No. 62-30211.
Powdered resins (hereinafter referred to as "granular phenol resins") proposed in the above publications are preferably used, but the resin is not limited thereto.

The above-mentioned "granular phenol resin" is a condensation product of phenols and formaldehyde, and has a larger molecular weight than resol resins and novolak resins, and has a polystyrene conversion molecular weight of 1,000 or more, preferably 2,000 to 2,000 by GPC (gel permini-silane chromatography). 20,000 granular or powdered resin with a T1-released phenol content of 500 as measured by liquid chromatography.
ppm or less, preferably 50 ppm or less.

When the above-mentioned granular phenolic resin is used, there is almost no phenol odor during work, and it has excellent stability and storage stability.
Prepreg has a long gelation time and is tack-free (in a down state with no stickiness), making it easy to form sheets, making it suitable.

In the present invention, epoxy resins include, for example, bisphenol A type, cresol novolac type, phenol novolac type, polyglycol type, cycloaliphatic type, long 11 II
l aliphatic type, brominated bisphenol type.

Examples include, but are not limited to, polyether-modified types, hydantoin types, and isocyanate types. Preferably, a bisphenol type phenol novolac type or a polyglycol type is used, and more preferably a polyether modified type is used.

In the present invention, the rubber component is not particularly limited, and includes, for example, nitrile rubber (NBR), styrene butadiene rubber (SBR), high styrene rubber, polybutadiene rubber, polyisoprene rubber, acrylic rubber, epichlorohydrin rubber, and hydrogenated nitrile rubber. , butyl rubber, etc., but NBR is preferably used, and a terpolymer copolymer having a carboxylic component is particularly suitable because it has strong adhesive strength.

The modified silicone oil used in the present invention is a linear polymer with siloxane bonds as its main chain, and has an organic functional group at the end or side chain in order to improve compatibility with carriers and reactivity. This has been introduced.

Specific examples include various modified silicone oils such as epoxy-modified, alkyl-modified, 7-amino-modified, carboxyl-modified, and alcohol-modified silicone oils, but are not limited to these.

The organic solvent used in the present invention is preferably one that dissolves thermosetting phenolic resin, epoxy resin, rubber component, and modified silicone oil, but is not limited to this, and some of the above components may be dissolved. It may be mixed with a solvent that does not dissolve it.

In addition, the solvent does not need to dissolve the entire amount of the resin component, and it is sufficient that it does not substantially inhibit impregnation in the prepreg impregnation process. There is virtually no problem even if this is not done. If undissolved components are particularly desired to be removed, a filtrate filtered using a glass filter, filter cloth, filter paper, or wire mesh filter may be used.

Examples of organic solvents used in the present invention include alcohols, ethers, and esters! 111. /y)

Examples include amides or mixed solvents of two or more thereof, such as methanol, propatool, butanol, acetone 2-methyl ethyl ketone, methyl isobutyl ketone, and methyl cellosolve.

Ethyl cellosolve, tetrahydrofuran, ethyl calpitol, butyl calpitol, acetic acid ester of ethyl ethyl calpitol acetate, acetic acid ester of butyl calpitol, DMF, DMSO, or a mixed solvent of two or more thereof are suitable, especially acetone and Methyl ethyl ketone is particularly preferred in terms of ease of handling and solubility.

In the composition of the present invention, the higher the blending ratio of phenolic resin, the better the flame retardance will be, but the adhesiveness will tend to be worse. 1! The ratio is preferably phenol resin J1M/(epoxy resin + rubber component decamodified silicone oil) -50150 to 9515, more preferably 60/40 to 90/10.

Further, the composition ratio of the epoxy resin and the rubber component is preferably epoxy resin/rubber component -50150 to 9 in terms of weight ratio.
0/10, more preferably 60/40 to 80/20. If the proportion of the rubber component is too small, the adhesion tends to deteriorate, and if the proportion of the rubber component is too large, the smoke generation properties will deteriorate, and in the process of impregnating the composition into glass cloth etc., impregnation spots will increase. It is in the 1st direction where it is difficult to obtain a uniform prepreg.

In the present invention, as the blending amount of modified silicone oil increases, the fluidity tends to improve and the fillet becomes longer, and the blending amount may be appropriately selected so as to obtain the desired fluidity and fillet length. Preferably 0.5 to 30% by weight based on the combined weight of the resin component and rubber component
, more preferably 1-15% by weight. Furthermore, in the present invention, although the rubber component improves adhesion, it tends to worsen fluidity. Therefore, the composition ratio of the rubber component and modified silicone oil is preferably such that the weight ratio of rubber component/modified silicone oil is Oil = 90/lO~20/80
The ratio is more preferably 75/25 to 30/70.

In the composition of the present invention, if the ratio of organic solvent is too high, the amount of resin deposited in the impregnation step will be small, and it will be necessary to repeat the impregnation to obtain the desired amount of deposit, and if the ratio is too low, the amount of resin deposited in the impregnation step will be small. Therefore, the weight ratio of the solvent is preferably (resin component/rubber component/modified silicone oil)/organic solvent -5/95.
~80/20, more preferably 30/70 ~ 60/4
It is 0.

The composition of the present invention may contain other additives, colorants, stabilizers, etc. in addition to the above-mentioned essential components.

In order to produce the thermosetting phenolic resin composition of the present invention, the above-mentioned resin component, NBR component, and modified silicone oil may first be dissolved in an organic solvent to form a solution, and the dissolution may be carried out by heating. However, in order to maintain the stability of the composition, it is preferable to carry out the dissolution at room temperature, and stirring may be performed using a homodisper, homogenizer, etc. Each component may be dissolved individually or simultaneously.

The composition of the present invention may be made immediately before prepreg production, for example by impregnating glass cloth immediately before use;
It may be manufactured and stored in advance.

A prepreg is obtained by impregnating a glass cloth with the composition of the present invention, for example, by dipping or spraying, and then drying the cloth. Further, by bonding the obtained prepreg with, for example, a Nomex honeycomb core and then heating and pressurizing it, a honeycomb sand winch panel can be obtained.

(Effects of the invention) In the present invention, the fluidity of the resin composition is improved by using the modified silicone oil, and prepregs obtained by impregnating glass cloth etc. with the thermosetting phenolic resin composition of the present invention has excellent surface smoothness, and can be fixed to a honeycomb core to form a honeycomb sand winch panel. The obtained honeycomb sandwich panel is M-flammable, has a large fillet length, has a stable and uniform adhesive state with little adhesive unevenness, and has a high adhesive peel strength. Such honeycomb sand winch panels are very suitably used as interior materials for aircraft, as well as for interiors of ships, vehicles, and buildings.

Furthermore, the composition of the present invention can be used for applications such as laminated boards and FRP as a face with good workability, and is very useful.

The present invention will be explained in detail with reference to Examples below. Before that, methods for measuring various characteristic values and a method for producing "granular phenol resin" in this specification will be described.

+11 Adhesive peel strength (Drum Beer strength) Measured on honeycomb sandwich panels by the Ni Drum Beer method (MIL-3TD-401B method).

+21 Flammability (self-extinguishing property): 6 sheets of the obtained prepreg were stacked together at a temperature of 150°C.
The composite material was heated and pressurized for 1 hour at a pressure of 3 kg/cm" to obtain a composite material. After igniting this composite material, one that extinguished within 15 seconds was considered to have self-extinguishing properties.

(3) Fluidity (fillet length) The prepreg obtained as shown in Fig. 1 was pasted on both sides of the honeycomb core, heated and pressed using ripe breath heat to form a honeycomb sand winch panel, and the cross section of this was observed. , second
As shown in the figure, the height of the resin flowing from the glass cloth to the honeycomb core was measured and determined as the fillet length.

Moreover, the "granular phenol resin" of this example was manufactured as follows.

"Production method of granular phenolic resin" In a 10j separable flask, 18% by weight hydrochloric acid and 7
10 kg of mixed aqueous solution containing % by weight of formaldehyde
I put it in. Although the room temperature was 20°C, the temperature of the mixed aqueous solution was maintained at 18°C by temperature adjustment. While stirring this, a diluted solution prepared by diluting 315 g of phenol with 35 g of water was added at once. Stirring was stopped 45 seconds after adding the diluent and the mixture was allowed to stand still, but the mixture suddenly became cloudy 68 seconds after stopping stirring, and a milky white product was observed, and this milky white product gradually turned pink. did. The liquid temperature is 18℃ as above.
The temperature gradually rose from 100 to 32°C, reached a peak of 32°C 15 minutes after adding the diluent, and then fell again. After the diluted solution was added and left for 160 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 at 30-3%
After being treated 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. Moisture content after drying is 0.
3% by weight, and the yield was 377g.

Most of the above contents were found to have a particle size of 1 when observed using an optical microscope.
It was a spherical to granular fine powder of ~15 microns, and more than 99% of the particles passed through a 100-meter mesh sieve. Furthermore, the weight average molecular weight in terms of polystyrene by GPC method was 3200, and the free phenol content was 32 ppm as measured by HPLC method. Chemical company, viscosity 30
~60 cps/25°C, epoxy equivalent 175~2
05] and liquid nitrile rubber (NBR) two balls DN60
1 (manufactured by Nippon Zeon).

Acrylonitrile value 27%, viscosity 600Qcps/70
°C, carboxyl group-containing ternary copolymer] and epoxy-modified silicone oil BY16-855 [manufactured by Toray Silicone, viscosity 24 cpa / 25 °C, epoxy equivalent 650] in a composition ratio (weight ratio) of phenol resin. /Epoxy resin/NBR/Modified silicone oil-7
0/201515 was dissolved in methyl ethyl ketone to obtain a festival with a solid content of 29% by weight.

Glass cloth KS1581/S920MN for this festival
(manufactured by Kanebo Co., Ltd.) and dried in a dryer at 110°C for 4 minutes to obtain a prepreg with a resin adhesion amount of 39%.This prepreg has a long gelation time and is tack-free.
Furthermore, there was no phenol odor and the workability was good.

Next, the obtained prepreg is made of Nomex honeycomb 5A.
Laminate on both sides of HI/8-3.0 (Showa Aircraft Industrial Model) and press at 150°C using a heat press.

A honeycomb sandwich panel was produced by molding at a pressure of 3.5 kg/cm'' for 1 hour.

Adhesion @ separation strength (drum beer strength) of the obtained prepreg and honeycomb sandwich panels.

The flammability and fluidity remained as shown in Table 1. As shown in Table 1, it has a high adhesive peel strength and is self-extinguishing,
It had a large fillet length.

(Comparative Examples 1 to 4) Faces were prepared by excluding the epoxy-modified silicone oil from the face components of Example 1 and using the blending amounts of the other components as shown in Table 1. Subsequently, prepreg and honeycomb sandwich panels were produced in the same manner as in Example 1. Various properties of the obtained prepreg and honeycomb sandwich panels are shown in Table 1, and the fillet length was short (Examples 2 to 7) Using the face component used in Example 1, granular phenolic resin and epoxy The ratio of resin is approximately 7:2 (weight ratio),
A festival, prepreg, and honeycomb sandwich panel were produced in the same manner as in Example 1, except that the amounts of other festival ingredients were as shown in Table 2. Various properties of the obtained prepreg and honeycomb sandwich panel are shown in Table 2 (Example 8.9).Instead of the epoxy modified silicone oil used in Example 1, the modified silicone oil shown in Table 3 (both manufactured by Toray Silicone) was used. ) was used, but a festival, prepreg, and honeycomb sand winch panel were produced in the same manner as in Example 1.

Various properties of the obtained prepreg and honeycomb sand winch panel are shown in Table 3. In the case of any of the modified silicone oils, the various properties are (Example 10.11) In place of the granular phenol resin used in Example 1 as the phenol resin, resol resin Shitsuunol BRL-24 was used.
0 or novolak resin Cytaunol BRL-592 (
A face, a prepreg, and a honeycomb sand winch panel were produced in the same manner as in Example 1, except that all of them were of the Showa Polymer type.

Various properties of the obtained prepreg and honeycomb sandwich panels are shown in Table 4.

Resol resin or Novo (Example 12.13) was used as the phenol IfMJ11. Instead of the polyglycol type used in Example 1 as the epoxy resin, bisphenol A type epoxy resin YD-12 was used.
8 or phenol novolank type epoxy resin YDPN
Example 1 except that -638 (all manufactured by Tobu Kasei) was used.
Fes, prepreg, and honeycomb sandwich panels were fabricated in the same manner as above.

Various properties of the obtained prepreg and honeycomb sand winch panel are shown in Table 5.

Even if bisphenol A type or phenol novolak type is used as the epoxy resin, various properties will be different (Example 14)
．． 15) Liquid NBR two balls D used in Example 1 as a rubber component
Instead of N601, use solid NBR Niball 1072J or styrene-butadiene rubber (SBR) Niball 2001.
A festival, prepreg, and honeycomb sandwich panel were produced in the same manner as in Example 1, except that the material (all manufactured by Nippon Zeon) was used.

Various properties of the obtained prepreg and honeycomb sandwich panels are shown in Table 6.

Liquid NBR, solid NBR or SBR as rubber component
Various properties were good no matter which one was used.

(Examples 16 to 19) In Example 1, bisphenol A was used as the epoxy resin.
A face, prepreg, and honeycomb sand winch panel were prepared in the same manner as in Example 1 using the same ingredients as in Example 1 in the amounts shown in Table 7, except that type epoxy resin YD-128 (manufactured by Tobu Kasei Co., Ltd.) was used. did. Various properties of the obtained prepreg and honeycomb sandwich panels are described in the seventh section.

[Brief explanation of drawings]

Figures 1 and 2 are diagrams explaining the method of measuring the fillet length, Figure 1 is an explanatory diagram explaining the structure of the honeycomb sandwich panel according to the present invention, and Figure 2 is a diagram explaining the method of measuring the fillet length. It is a cross-sectional explanatory view for explanation. 1...Glass cloth, 2...Honeycomb, 3.
...resin composition, 4...bubble, L...fillet length. Figure Figure

Claims (1)

[Claims] Thermosetting phenolic resin, epoxy resin, rubber component,
A thermosetting phenolic resin composition comprising a modified silicone oil and an organic solvent.