JPH02129234A - Flame-retardant phenol resin prepreg - Google Patents

Abstract

PURPOSE:To obtain the title prepreg with excellent adhesiveness and flame retardancy and low heat buildup and smoking characteristics by compounding a thermosetting phenol resin with an epoxy resin, an acrylonitrile-butadiene rubber and a resin-coated red phosphorus. CONSTITUTION:A thermosetting phenol resin (a specified granular phenol resin is especially pref. as it emits hardly phenolic odor, provides a varnish with a high viscosity, has excellent stability and storage characteristics, and exhibits little tackiness) is compounded with an epoxy resin (a polyglycol type epoxy resin is pref. as the flexibility is increased by using it), an acrylonitrile-butadiene rubber and a resin-coated red phosphorous. The title prepreg with excellent adhesiveness and flame retardancy and low heat buildup and smoking characteristics during burning and suitable for preparing honeycomb sandwich panels used for structural materials of airplanes, sporting goods, ships, buildings, etc., is obtd.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a flame-retardant phenolic resin prepreg with excellent adhesion and processability, and more specifically, it has a low calorific value and smoke emission during combustion, and is suitable for aircraft use. , relates to a flame-retardant phenolic resin prepreg suitable for manufacturing structural materials and interior materials for vehicles, ships, buildings, etc.

(Prior Art) In recent years, honeycomb sandwich panels have been widely used as structural materials for aircraft, sporting goods, ships, buildings, etc. because they are lightweight and have excellent strength and rigidity.

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 Nomex DuPont, aromatic polyamide nonwoven fabric), and the surface material is made of aluminum or wA fiber reinforced plastic material.

In particular, aircraft interior panels often use Nomex honeycomb and plastic surface materials reinforced with glass@fiber, Kevlar fiber, and carbon fiber. In addition, modern aircraft interior materials are designed to ensure the safety of passengers in the event of a fire.
There is a need for materials that are flame retardant and generate less smoke and less heat when burned.

Conventionally, woven fabrics of these reinforcing materials have been impregnated with matrix resin and epoxy resin or phenol resin to form prepregs, and honeycombs have been pressurized and heated to form honeycomb sandwich panels.

However, although epoxy m8Iv has good adhesion,
The heat generated during combustion and the amount of smoke emitted are unfavorable, and although phenolic resin is flame retardant and has low smoke emitting properties, it has the disadvantage of low adhesive peel strength when used as a surface material for honeycomb panels. .

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 storage stability and may generate bad odors during the prepreg manufacturing process. , there are many problems such as the need for high-concentration festivals and work.

(Problems to be Solved by the Invention) In view of the above problems, the present inventors have conducted extensive research and have found that:
A mixture of thermosetting phenolic resin, epoxy resin, acrylonitrile-butadiene rubber, and red phosphorus coated with resin has excellent adhesion and flame retardancy, especially low heat generation and low smoke generation when burned. I found out that
This completes the present invention.

An object of the present invention is to provide a flame-retardant phenolic resin prepreg for manufacturing honeycomb sandwich panels, which has high adhesive peel strength, generates low heat generation and smoke when burned.

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

(Means for Solving the Problems) The above object of the present invention is a! In the fat prepreg, flame-retardant phenolic resin prepreg is characterized by using thermosetting phenolic resin, epoxy resin, acrylonitrile-butadiene rubber, and a matrix resin whose main component is red phosphorus coated with resin. achieved.

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. 62-10211.
Powdered phenol resin (hereinafter referred to as "granular phenol resin") proposed in the above publication is preferably used, but is not limited thereto.

Granular phenolic resin has a larger molecular weight and less free phenol than resol resins and novolac resins, so there is almost no phenol odor during operation, and it is easy to obtain high-viscosity surfaces (and has excellent stability and storage stability). ,
It is extremely suitable for use because it has less sticky residue and is easy to form sheets.

In the present invention, epoxy resins include, for example, bisphenol A type, cresol novolac type, phenol novolac type, polyglycol type, cycloaliphatic type, long chain aliphatic type, brominated bisphenol type, hydantoin type, isocyanate type, etc. but is not limited to these. Preferably, bisphenol A type, cresol novolac type, phenol novolak type, and polyglycol type are used, and polyglycol type is particularly preferred since it increases the flexibility of the prepreg. Also, epoxy m1
ll may be either liquid or solid as long as it becomes a solution as a composition.

In the present invention, acrylonitrile-butadiene rubber (hereinafter referred to as NBR) refers to a copolymer rubber containing acrylonitrile and butadiene as main components, but also includes a ternary copolymer rubber containing, for example, acrylic acid and methacrylic acid. It will be done. In particular, 3 with carboxylic components
It is preferable that the original copolymer has strong adhesive strength.

The red phosphorus coated with fat used in the present invention is red phosphorus whose surface has been coated with a resin. can be mentioned.

With the above resin? & The particle size of the overturned red phosphorus is preferably 10
It is 0μ or less, more preferably 60μ or less, and still more preferably 20μ or less. When the particle size exceeds 100 μm, dispersion tends to be poor and non-uniform, and impregnation spots and insufficient concentration tend to occur during the step of impregnating the obtained matrix resin onto the base material. Furthermore, if the particle size exceeds 50μ, the dispersibility and flame retardancy tend to be poor.

Note that red phosphorus that is not coated with a resin is chemically unstable and decomposes under the influence of the atmosphere and moisture in the solvent, so it cannot be applied to the present invention.

In the matrix resin of the present invention, phenolic Ij
The greater the blending ratio of B fat, the better the smoke generation properties will be, but the adhesion will be poor (there is a tendency for the composition ratio to be a weight ratio, preferably phenol gs/<, x boxy resin + NBR component). -50150 to 9515, more preferably 7 G/30 to 90/10.

Further, the composition ratio of the epoxy resin and the NBR component is preferably epoxy resin/NER component = 50150 in terms of weight ratio.
~9G/10, more preferably 80/40~8G/
It is 20. If the proportion of the NBR component is too small, the adhesion tends to be poor.If the proportion of the NBR component is too large, the smoke generation properties will be poor, and in the process of impregnating the composition into glass cloth, etc., there will be many impregnated spots. Therefore, it tends to be difficult to obtain a uniform prepreg.

Examples of the base material in the present invention include various glass fibers,
Examples include, but are not limited to, carbon fiber, aramid fiber, graphite fiber, silicon carbide fiber, and the like. Further, the form of the base material is not limited to am itself, but may be in the form of a fiber structure such as a satin-woven, plain-woven, or twill-woven fiber or a unidirectional fiber. These base materials have the required strength, stiffness,
It can be freely selected depending on weight and economic efficiency.

Next, a general method for producing the flame-retardant phenolic Li1 fat prepreg of the present invention will be explained.

First, the thermosetting phenolic resin, epoxy resin,
and NBR are dissolved in an organic solvent to form a solution. Examples of organic solvents include methanol, propatool, butanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl cellosolve, ethyl cellosolve, tetrahydrofuran, ethyl calpitol, butyl calpitol, ethyl acetate, acetic acid ester of ethyl calpitol,
Butylcarpitol acetate, DMF%DM80
etc., or a mixed solvent of two or more of them is suitable.
Among these, acetone and methyl ethyl ketone are particularly preferred in terms of ease of handling and solubility.

Next, the matrix resin of the present invention can be produced by adding the red phosphorus coated with the resin described above while stirring.

As the amount of resin-coated red phosphorus increases, the flame retardancy improves and the amount of PjI4 emitted during combustion decreases, but if it is too large, the viscosity of the solution becomes low and the impregnating process of the base material becomes difficult. Impregnating properties deteriorate.In the present invention, red phosphorus coated with resin exhibits a sufficient effect with a content of about a few percent, so it is preferably 10% by weight or less, more preferably 5% by weight or less based on the resin component. used.

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

Next, the matrix resin for impregnation obtained by the above method is impregnated into the base material by, for example, dipping, spraying, or a hot melt method, and then dried as necessary (the W1 flammable phenol of the present invention). Any type prepreg can be obtained.

Furthermore, a honeycomb sandwich panel can be obtained by laminating the prepreg of the present invention on both sides of a honeycomb core made of Nomex paper, for example, and then pressurizing and heat-forming the core using a heat press machine, an autoclave, or the like.

The present invention will be explained in detail with reference to Examples below. Before that, we will explain the method for measuring the retention time and the manufacturing method for "granular phenol S" in this specification.

(1) Adhesive peel strength (drum peel strength): A honeycomb sandwich panel was measured using a drum peel method (MIL-8TD-401B method).

(2) Smoke generation (N]3S Ds@): NBS method (
The honeycomb sandwich panel was measured using ASTM-E-662 (non-flame method). If the light transmittance inside the chamber is T%, then DS=1311oy on o.

(5) Calorific value: After taking the resin component in the prepreg into an aluminum foil cup and heating it in a hot oven at 150°C for 1 hour,
Cooled. The cooled material was pulverized, heated to 700°C at 10°C/min using TG-DTA (manufactured by Rigaku Denki), and determined from the exothermic peak area.

(4) Ratio between the weight difference before and after heating and the weight before heating when volatile content nipuri preg is heated at 150°C for 15 minutes.

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

"Production method of granular phenolic resin" In a separable flask of 101, add 18% by weight hydrochloric acid and 7
10 k of mixed water bath solution containing % by weight of formaldehyde
I put y. Although the room temperature was 20°C, the temperature of the mixed water bath was maintained at 18°C by temperature adjustment. While stirring this, a diluted solution prepared by diluting phenol 315f with water 559 was added all 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 temperature of the liquid gradually rose from 18°C, and reached 32°C within 15 minutes after adding the diluent.
It reached a peak of °C and dropped again. After adding diluent 6
After standing for 0 minutes, the resulting mixed water bath solution was stirred again for 5 minutes. The solid-liquid separated contents were washed with water using a glass filter, and treated in an aqueous ammonia solution of o, sit amount % at a temperature of 30 to 32"C for 2 hours, and then washed with water.
It was then dehydrated and dried at a temperature of 35°C for 8 hours. The moisture content after drying was 0.3% by weight, and the yield was 571f.

When observed with an optical microscope, the majority of the contents marked with are found to have a particle size of 1.
It was a spherical to granular fine powder of ~15μ.

Furthermore, the weight average molecular weight in terms of polystyrene by GPO method was 3200, and the free phenol content was 32 ppm as measured by HPLO method.

(Example 1) Granular phenol resin, bisphenol type epoxy m fat Edetoto YD128 (manufactured by Toto Kasei, epoxy equivalent: 18
9] and acrylonitrile-butadiene rubber (NBR
) Two-ball 1072J (manufactured by Nippon Zeon, acrylonitrile value 27%, carboxyl foundation F ternary copolymer) was added to methyl ethyl ketone at room temperature with a composition ratio (weight ratio) of phenol resin/epoxy resin/NB = 8/2/1. A varnish was obtained.The solid content concentration of this varnish was 49.1%.

Next, Red Phosphorus Noballet 120UF (manufactured by Phosphorus Handicraft Co., Ltd., average particle size 10 μm) coated with 11% J was added to the resin component of this varnish to prepare Mad JTxΩ fingers.

This matrix resin is applied to glass cloth KS 181/A.
-11001 made by MBO] and then put in a dryer))
It was dried at 80"C for 0 minutes to produce a prepreg with an M content of 40% and a volatile content of 4.5%.
The state of dispersion of Nopalette 120UF in the matrix resin was good, and there were no impregnation spots in the obtained prepreg. Furthermore, there was no phenol odor associated with the phenolic resin, and the workability was good.

Next, the obtained prepreg was coated with a Nomex honeycomb 8
It was pasted on both sides of AH1/8-3.0 (manufactured by Showa Aircraft Industry Co., Ltd.) and heated to a temperature of 5G"o using a heat press.

A honeycomb sandwich panel was produced by molding at a pressure of 3.5 J/am2 for 1 hour.

The adhesive peel strength, exothermic property and smoke emitting property during combustion of the obtained prepreg and honeycomb sandwich panel were as shown in Table 1. As shown in Table 1, the heat generation amount due to combustion was small (the amount of g!! produced was small (and the adhesive peel strength was large), and the property results were good.

(Examples 2 to 5) Red phosphorus nobalette 12 coated with resin in Example 1
The blending amount of 0 UF was not 35% by weight based on the resin component of the varnish, but the resins shown in Table 1 were blended in the range of 1 to 10% by weight. The other methods were the same as in Example 1.
, prepared prepreg and honeycomb sandwich panels, respectively.

Table 1 shows the combustion heat generation properties, smoke generation properties, and adhesive peel strengths of the obtained prepreg and honeycomb sandwich panels. The adhesive peel strength tends to decrease slightly as the amount of resin-coated red phosphorus increases, and the calorific value reaches saturation at a compounding amount of about 5 weight 2, and furthermore, the amount of smoke emitted increases as the compounding amount increases. There was a tendency to decrease.

(Comparative Example 1) A prepreg and a honeycomb sandwich panel were created in the same manner as in Example 1, except that the resin-coated red phosphorus was not blended.

Various properties of the obtained prepreg and honeycomb sandwich panels are shown in Table 1. As shown in Table 1, the adhesive peel strength was large and good, but the amount of heat generated was large (unfavorable).

(Comparative Example 2) A prepreg and a honeycomb sandwich panel were prepared in the same manner as in Example 1, using only a granular phenolic resin as the matrix resin component.

Table 1 shows the grip properties of the obtained prepreg and honeycomb sandwich panels. As shown in Table 1, the adhesive peel strength is low and the calorific value is high. (Example 6) The same procedure as in Example 1 was used except that Norbalet 120 with an average particle size of 25 μm was used as the resin-coated red phosphorus. Matrix resin and prepreg were prepared by the method. No bullet 1
The state of dispersion of No. 20 into the matrix resin was slightly inferior to that of Noballet 120UF, which had a smaller average particle size.

Subsequently, a honeycomb sandwich panel was created in the same manner as in Example 1.

Various properties of the obtained prepreg and honeycomb sandwich panel are shown in Table 2, including those of Example 1 and Comparative Example 1 for comparison. As shown in Table 2, the smaller the particle size of red phosphorus coated with resin, the more it burns (Example 7). ,
Prepreg and honeycomb sandwich panels were created in the same manner as in Example 1.

Table 5 shows various properties of the obtained prepreg and honeycomb sandwich panel. As shown in Table 5 (adhesion and peeling strength is the same as in the case of granular phenol even when resol resin is used as the phenolic resin, (Example 8) Nipol 1042 [manufactured by Nippon Zeon, acrylonitrile value 33] was used instead of Nipol 1072J. %, carboxyl group-free copolymer] was used as the NER component, prepregs and honeycomb sandwich panels were prepared in the same manner as in Example 1.

Table 4 shows the properties of the prepreg and honeycomb sandwich panels obtained. The temperature characteristics were good.

(Comparative Example 3) A matrix resin, a prepreg, and a honeycomb sandwich panel were produced in the same manner as in Example 1, except that NBR was not used as the matrix resin component.

Table 4 shows various properties of the obtained prepreg and honeycomb sandwich panel. N in the matrix resin component
If BR was not used, the adhesive peel strength was low, which was not preferable.

(Examples 9 to 12) As epoxy m81 in the matrix resin component, the fifth
A matrix resin, prepreg, and honeycomb sandwich panel were prepared in the same manner as in Example 1, except that the materials shown in the table were used.

Table 5 shows the combustion heat generation properties, smoke generation properties, and adhesive peel strengths of the obtained prepreg and honeycomb sandwich panels. In the case of any epoxy resin (Examples 13 to 18) Example 1 except that the blending ratio of epoxy resin and NE in the matrix resin component was as shown in Table 6.
Matrix resin, prepreg, and honeycomb sandwich panels were prepared in the same manner as described above.

The temperature characteristics of the obtained prepreg and honeycomb sandwich panels are shown in Table B. The adhesive peel strength increases as the NB phosphoric acid component ratio increases, but (Examples 19 to 25) the same polyglycol type epoxy resin DER738 and NBR Nibor 1072J used in Example 1 were used in a composition ratio of epoxy resin/NBR. Ingredients = 3/1, granular phenol li! was dissolved in methyl ethyl ketone at a composition ratio of fat as shown in Table 1, and then Red Phosphorus Norvalet 120 [JF coated with 2 to 5% by weight of resin was blended to prepare a matrix resin. Subsequently, prepreg and honeycomb sandwich panels were produced in the same manner as in Example 1. Table 7 shows the various custom orders obtained.

As shown in Table 7, the adhesive peel strength tended to increase as the epoxy resin and NB layer increased.

The following is a blank □＼,"・,・;V] (Examples 26 to 27) As the base material, instead of glass cloth Kg 181/A-1100, Kevlar cloth 285/KE420 [manufactured by Kanebo], carbon cloth OIMIO1 (manufactured by Kanebo), the resin content was 58% in the case of Kevlar cloth, 49% in the case of carbon cloth, and the same method as in Example 1 except that the matrix weight per unit area was the same as in the case of glass cloth. Honeycomb sandwich panels were made using the prepreg prepared in 1, and the characteristics of 6 panels were investigated.The results are shown in Table 8.

As shown in Table 8, the same effects were obtained even when the types of substrates were different.

The details of the base materials used in the above examples are shown in Table 9 (Effects of the Invention) The flame-retardant phenolic resin prepreg of the present invention has excellent adhesive properties and can be used in addition to honeycomb sandwich panels, laminates,
It can also be used for FRP and other purposes. The honeycomb sandwich panel made using the prepreg of the present invention is flame retardant, produces low smoke and heat generation even when burned, and is used as an interior material for aircraft, as well as interior materials for ships, vehicles, and buildings. It is also suitable as

(Spontaneous) June 1, 1999] Display of the case Patent Application No. 283202 of 1988 Title of the invention 5゜6゜ Contents of the amendment in the "Detailed Description of the Invention" column of the specification subject to the amendment (1 ) Bisphenol A type epoxy resin on page 12, lines 18 to 20 of the specification...Epoxy equivalent: 189
) J and it says “Polyglycol type epoxy resin DER7
36 (manufactured by Dow Chemical, epoxy equivalent weight 193, n-3
Corrected to 33.

Address 5-17-4 Sumida, Sumida-ku, Tokyo 1-5-90 Tomobuchi-cho, Bejima-ku, Osaka 534 Kanebo Co., Ltd. Patent Department Telephone (06) 911-1251

Claims (1)

[Claims] In resin prepreg, thermosetting phenolic resin,
A flame-retardant phenolic resin prepreg characterized by using epoxy resin, acrylonitrile-butadiene rubber, and a resin-coated matrix resin whose main component is red phosphorus.