JPH0715040B2 - Flame-retardant phenolic resin composition and prepreg using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is excellent in adhesiveness and processability, flame retardant,
A flame-retardant phenolic resin composition suitable for producing interior materials and structures for aircraft, vehicles, ships, buildings, etc., which has small heat release (heat dissipation) and smoke release (smoke) during combustion, and uses thereof It was about prepreg.

[Conventional technology]

In recent years, in order to ensure the safety of passengers in the event of a fire, an ultra-flame retardant material, that is, a material having low heat release and smoke release at the time of combustion, has been demanded for aircraft interior materials.

In particular, panels used for aircraft interiors often use Nomex (DuPont aromatic polyamide non-woven fabric) honeycomb or plastic surface material reinforced with glass fiber, Kevlar fiber or carbon fiber. The need for ultra flame retardant is required.

Conventionally, a woven fabric of these reinforcing materials is impregnated with an epoxy resin as a matrix resin to form a prepreg, and a honeycomb sandwich panel is formed by pressurizing and heating the honeycomb.

However, although the epoxy resin has good adhesiveness, the heat release and the smoke release during combustion are large, which is not preferable.

Therefore, an attempt was made to use a phenol resin as a matrix resin. Phenolic resin has a low smoke release, but has a large heat release, and has a disadvantage of low adhesive peel strength when used as a surface material of a honeycomb panel. was there.

[Problems to be Solved by the Invention]

The present inventors, in view of the above problems, as a result of earnest research,
Using a specific thermosetting phenolic resin, a specific polyvinyl butyral resin, a specific brominated flame retardant and an antimony trioxide matrix resin, it is flame-retardant and has excellent adhesiveness and low heat during burning. The present invention has been completed by finding that it is a release and a low smoke release.

An object of the present invention is to provide a flame-retardant phenolic resin composition for producing a honeycomb sandwich panel, which has a large adhesive peeling strength and a low heat release and a low smoke release at the time of burning, and a prepreg using the same.

[Means for Solving the Problems]

The object of the present invention is as follows: (a) a crosslinking degree index of 60 or more and a free phenol index of 30
The following thermosetting phenolic resin, (b) polyvinyl butyral resin having a polymerization degree of 1500 or more, (c) general formula, (In the formula, R ₁ is -H or Or CH ₂ CH ₂ O _{m ′} H, and R ₂ is —H or —CH ₃
And m is 1 to 3 and m ′ is 1 to 3), or a brominated phenol derivative represented by the following formula: (In the formula, n is 0 to 2) and a brominated bisphenol A derivative represented by the following formula (d) and (d) antimony trioxide are used.

Further, another object of the present invention is achieved by a prepreg obtained by impregnating a base material with a synthetic resin, the synthetic resin comprising the flame-retardant phenolic resin composition.

In the present invention, the degree of crosslinking index is a phenolic resin Ag
(About 10g) in an aluminum tray, 1 at 120 ℃ in the oven
After curing for an hour, the weight of the undissolved material when immersed in acetone for 30 minutes is Bg, It is the value obtained by.

The free phenol index is defined as the amount of free phenol quantified by the Gala chromatography method as C% and the solid content concentration of the phenolic resin as D%, It is the value obtained by.

In the present invention, the thermosetting phenolic resin is a resin produced from aldehydes and phenols, and can be mentioned as, for example, resole, but in particular, the crosslinking degree index is 60 or more, the free phenol index is Below 30.

In the present invention, the degree of crosslinking of the thermosetting phenolic resin is
When the free phenol index is 60 or more, the object of low heat release and low smoke release is achieved when the free phenol index is 30 or less, but the crosslinking index is preferably 80 or more and the free phenol index is 30 or less, more preferably the crosslinking degree. Index is
90 or more and a free phenol index of 15 or less.

The polyvinyl butyral resin used in the present invention is, for example, a polyvinyl acetal resin obtained by reacting polyvinyl alcohol with butyraldehyde, and particularly has a degree of polymerization of 1500 or more.

In the present invention, the polymerization degree of polyvinyl butyral resin is 1500
In the above cases, the purpose of high adhesiveness is achieved. If it is less than 1500, the adhesion will be poor.

The polyvinyl butyral resin used in the present invention usually has three components of a vinyl butyral component, a vinyl alcohol component and a vinyl acetate component. Particularly, a carboxyl-modified resin as the fourth component has particularly high adhesiveness. preferable.

The brominated phenol derivative and brominated bisphenol A derivative used in the present invention are bromine compounds having a reactive group and usually soluble in an organic solvent. Therefore, the prepreg of the present invention obtained by impregnating the resin composition of the present invention in, for example, glass cloth and drying the prepreg of the present invention, when the prepreg is heat-cured and molded, the bromine compound is integrated as a flame retardant. Therefore, there is no bleeding (bleeding) from the product or deterioration of the adhesiveness, and the performance of the product is not deteriorated.
In particular, when a brominated phenol derivative is used, the fluidity of the prepreg becomes good, and there are great advantages such that it melts during heat treatment and spreads well.

The antimony trioxide used in the present invention is not particularly limited as long as it is dispersed in the resin composition, but usually has a particle size of 0.1 to 10 μm, preferably 0.5 to 5 μm.

The resin composition of the present invention may be used without a solvent, that is, by hot melt, but it is usually used as a solution. As the solvent, an organic solvent is generally used, but an aqueous medium may be used if it is soluble. Further, the solvent is preferably a solvent that dissolves the organic three components of the phenol resin, butyral resin and bromine compound in the resin composition of the present invention, but does not dissolve antimony trioxide, but is not limited thereto. Instead, it may be a mixture of some solvents that do not dissolve the above components.

Examples of the organic solvent used in the present invention include alcohols, ethers, ketones, amides, and the like.
Examples include mixed solvents of one or more kinds. Specifically, for example,
Methanol, propanol, butanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl cellosolve, ethyl cellosolve, tetrahydrofuran, ethyl carbitol, butyl carbitol, ethyl acetate,
Acetic acid ester of ethyl carbitol, butyl carbitol and acetic acid ester, dimethylformamide, dimethylsulfoxide or a mixed solvent of two or more thereof are suitable, and among them, acetone and methyl ethyl ketone are particularly preferable in terms of handleability and solubility.

The amount of the solvent used may be selected according to the use of the composition of the present invention, and for example, in the case of prepreg use, the solid content / solvent may be 5/95 to 80/20.

The blending ratio of each component in the composition of the present invention is not particularly limited and may be selected according to the desired performance.

The higher the component ratio of the thermosetting phenolic resin in the composition, the higher the flame retardancy, so the compounding ratio may be selected according to the desired flame retardancy, and usually 50% by weight or more of the solid content. , Preferably used in an amount of 60 to 95% by weight. If it is less than 50% by weight, the smoke release becomes large.

As the component ratio of the polyvinyl butyral resin is higher, the adhesiveness is better, but if it is too large, the viscosity of the composition increases or the flame retardancy decreases, so that the solid content is preferably 1 to 15 %, More preferably 2 to 12% by weight, further preferably 3 to 10% by weight. If it is less than 1% by weight, the adhesiveness will be poor, and if it is more than 15% by weight, the viscosity of the resin composition will be high.

Although the heat release decreases as the component ratio of the bromine compound increases, it is usually used at 0.1 to 20% by weight of the solid content. If less than 0.1% by weight, the heat release becomes large, and 2
If it is more than 0% by weight, the smoke release becomes large.

The component ratio of antimony trioxide is 0.1 to 20% by weight, preferably 1 to 15% by weight. If it is less than 0.1% by weight, heat release is large and flame retardancy becomes insufficient. If it is more than 20% by weight, the dispersion of this component is poor and it is difficult to form a uniform resin composition.

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

The thermosetting phenolic resin composition of the present invention and the prepreg using the same can be produced, for example, as follows. That is, the thermosetting phenol resin, polyvinyl butyral resin and bromine compound are added to an organic solvent and dissolved to form a solution. The polyvinyl butyral resin may be dissolved in an organic solvent in advance and added. Dissolution
In order to maintain the stability of the resin composition, it is preferably performed at room temperature or lower, and may be stirred with a homodisper or the like. Subsequently, antimony trioxide is added to the obtained solution, and the mixture is vigorously stirred with a homodisper or the like to be uniformly dispersed to obtain the thermosetting phenolic resin composition of the present invention.

Subsequently, the obtained resin composition is impregnated into a glass cloth with a prepreg machine or the like and dried to obtain the prepreg of the present invention. Furthermore, after bonding this with a honeycomb core made of Nomex, for example, by heating under pressure,
It can be a honeycomb sandwich panel.

〔The invention's effect〕

The resin composition of the present invention and a prepreg using the same,
Unusually low heat release and low smoke release, yet capable of exhibiting high adhesiveness, the thermosetting phenolic resin prepreg obtained in the present invention is fixed to the honeycomb core to form a honeycomb sandwich panel. You can

The obtained honeycomb sandwich panel is flame-retardant, has low heat release and low smoke release, and has a high adhesive peel strength between the surface material, the core and the surface material.

Such a honeycomb sandwich panel is very suitably used not only as an interior material for an aircraft, but also as an interior material for ships, vehicles and structures.

Further, the prepreg of the present invention can be used in applications such as a laminate and FRP, and is extremely useful.

〔Example〕

 Hereinafter, the present invention will be further described with reference to examples.

The measurement of various characteristic values in this specification was based on the following methods.

[Heat release]

A sandwich panel and heat release measured according to US Federal Standard FAR 25.853 (A) were evaluated with a total value of 2 minutes and a peak value of 5 minutes.

[Smoke release]

It is the Ds value in the sandwich panel measured by the NBS method (ASTM-E-662) and the flame method. When the transmittance in the chamber is T%, [Adhesive peel strength (drum peel strength)] The honeycomb sandwich panel was measured by the drum peel method (MIL-STD-401 B method).

(Resin solid content)

Taking the resol resin Eg (about 0.5g) in an aluminum cup and curing it in an oven at 150 ° C for 1 hour, the weight of the solid content is Fg, [Volatile content] If the weight after heating prepreg Gg of 100 × 100 mm in size at 150 ° C for 15 minutes is Hg, Example 1 Phenolic resin, Shonor BRS 325 (manufactured by Showa Polymer Co., Ltd., methanol solution, solid content concentration 62.1%, crosslinking degree index 9
3, 153 parts of free phenol index 11), polyvinyl butyral resin, Denka butyral 6000EP (manufactured by Denki Kagaku Kogyo,
Polymerization degree 2400, carboxyl modified type, 10% MEK solution) 5
0 part, brominated phenol derivative, prasefty EB200 B
(Manufactured by Manac, dibromophenol monoepoxy derivative, Br content 51%) 7.8 parts was put into a dissolution vessel equipped with a cooling jacket and a homodisper, and dissolved by stirring. Next, 4.7 parts of antimony trioxide and PATOX-C (manufactured by Nippon Seiren Co., Ltd.) were added, and the mixture was stirred and dispersed. Finally, the concentration was adjusted with methyl ethyl ketone.

The obtained resin composition has a viscosity of 97 cps and a solid content concentration of 38.5.
% By weight. This resin composition is treated with glass cloth, KS 1
After impregnating 81 / S920 NM (made by Kanebo), dry it at 70 ℃
10 minutes, and further dried at 90 ° C for 15 minutes to obtain a prepreg having a resin adhesion amount of 42% by weight and a volatile content of 5.9% by weight.

Next, the obtained prepreg is a Nomex type honeycomb,
It sticks on both sides of SAH 1 / 8-3 (Showa Aircraft Industry Co., Ltd.), and it is 45 at a pressure of 3.5kg / cm ² from room temperature to 121 ° C with a heat press machine.
The temperature was raised in minutes, the temperature was maintained for 1 hour, and then cooled to manufacture a honeycomb sandwich panel. The heat release, smoke release and drum peel strength of the obtained honeycomb sandwich panel are as shown in Table 1, and the heat release, smoke release and heat release were low, and the adhesive peeling strength was large, showing good characteristic results.

Examples 2 to 3 Instead of the phenolic resin used in Example 1, phenolic resins having different cross-linking index and free phenol index, Shonor BRS 324 (manufactured by Showa High Polymer, solid content concentration 5)
7%), and Shonor BLS 352 (manufactured by Showa High Polymer, solid content concentration 51%) in the same manner as in Example 1 to prepare a resin composition, a prepreg and a honeycomb sandwich panel.

The heat release, smoke release and drum peel strength of the obtained honeycomb sandwich panel are as shown in Table 1, and the heat release and smoke release increase as the crosslinking index decreases or the free phenol index increases, and the drum release increases. The peel strength tended to decrease.

Comparative Example 1 Instead of the phenolic resin in Example 1, a phenolic resin having a low crosslinking index and a high free phenolic index, Shonor CKS 343 (manufactured by Showa High Polymer, solid content concentration 4
6%) was used to manufacture a resin composition, a prepreg and a honeycomb sandwich panel in the same manner as in Example 1.

The heat release, smoke release, and drum peel strength of the obtained honeycomb sandwich panel are as shown in Table 1. When the crosslinking index is small and the free phenol index is large, the heat release and smoke release are large, and the flame retardancy is high. It was insufficient.

Example 4 The amount of polyvinyl butyral resin in Example 1 was set to 100.
Resin composition in the same manner as in Example 1 except that parts are changed to
A prepreg and a honeycomb sandwich panel were obtained. The results are shown in Table 2, and although the adhesiveness was further improved, the clay of the resin composition was slightly higher.

Example 5 Instead of the polyvinyl butyral resin in Example 1,
Non-carboxylated Denka Butyral 6000c
A resin composition, a prepreg, and a honeycomb sandwich panel were obtained in the same manner as in Example 1 except that (Electrochemical Industry Co., Ltd., polymerization degree 2400, 10% MEK solution) was used. The results are shown in Table 3, and the adhesiveness was slightly inferior to that of the carboxyl type resin, but the adhesiveness was sufficiently good.

Comparative Example 2 Instead of the polyvinyl butyral resin in Example 1,
A resin composition prepreg and a honeycomb sandwich panel were obtained in the same manner as in Example 1 except that Denka Butyral 3000-4 having a degree of polymerization of 830 (manufactured by Denki Kagaku Kogyo, 10% MEK solution) was used. The results are shown in Table 3, and the adhesiveness deteriorated as the degree of polymerization decreased.

Examples 6 to 7 Instead of the brominated phenol derivative in Example 1, 7.0 parts of Piroguard SR324 (Daiichi Kogyo Seiyaku Co., tribromophenol ethylene oxide adduct, Br content 57%) or Epotote YDB400 (Toto Kasei, Tetra. A resin composition prepreg and a honeycomb sandwich panel were prepared in the same manner as in Example 1 using 8.2 parts of a bromobisphenol A derivative and a Br content of 49%).

The heat release, smoke release and drum peel strength of the obtained panel are as shown in Table 4, and almost the same performance was exhibited by using any of the reactive bromine compounds.

Comparative Example 3 Instead of the brominated phenol derivative used in Example 1, a non-reactive additive type bromine compound, Prasefty EB-10.
When 9.8 parts of 0 (manac, decabromodiphenyl ether, Br content 82%) was used, impregnating ability of the resin composition into the prepreg was poor, and only a resin having a poor appearance was obtained,
In addition, molding could not be performed smoothly due to insufficient fluidity.

Example 8 The same method as in Example 1 except that carbon cloth, CF3101 (made by Kanebo) was used instead of the glass cloth in Example 1, and the amount of resin adhered per unit area was the same as in the case of glass cloth. Honeycomb sandwich panels were prepared using the prepreg prepared in the above, and heat release, smoke release and drum peel strength were measured. The results are shown in Table 5, and the same effect was exhibited even when the type of the base material was different. The details of the base material used in the above examples are shown in Table 6.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location C08L 61/06 LMS // (C08L 61/06 29:02) (56) Reference JP-A-58 -224038 (JP, A) JPB 49-14951 (JP, B1)

Claims (2)

[Claims] 1. As an essential component, (a) a crosslinking degree index of 60 or more and a free phenol index of 30.
The following thermosetting phenolic resin, (b) polyvinyl butyral resin having a polymerization degree of 1500 or more, (c) general formula, (In the formula, R ₁ is -H or Or CH ₂ CH ₂ O _{m ′} H, and R ₂ is —H or —CH ₃
And m is 1 to 3 and m ′ is 1 to 3), or a brominated phenol derivative represented by the following formula: (In the formula, n is 0 to 2) A flame-retardant phenolic resin composition comprising a brominated bisphenol A derivative represented by: and (d) antimony trioxide. 2. A prepreg obtained by impregnating a base material with a synthetic resin, wherein the synthetic resin comprises the flame-retardant phenolic resin composition according to claim 1.