JPH0753817B2 - Flame-retardant phenolic resin composition, prepreg using the same, honeycomb sandwich panel and laminate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is excellent in adhesiveness and processability, flame retardant,
There is little heat release (heat dissipation) and smoke release (combustion) at the time of combustion, and it is a flame-retardant phenolic resin composition that is officially used for the manufacture of interior materials and structures for aircraft, vehicles, ships, buildings, etc. The present invention relates to a prepreg used, a honeycomb sandwich panel and a laminated board.

[Conventional technology]

In recent years, in order to ensure the safety of passengers in the case of fire, interior materials for aircraft are required to be materials that are super flame-retardant, that is, have low heat release and smoke release during combustion.

In particular, panels used for aircraft interiors often use Nomex (Dupo 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 manufactured by pressurizing and heating a hachicam.

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 a matrix resin containing antimony pentoxide, 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 large adhesive peel strength, a flame-retardant phenolic resin composition for producing a honeycomb sandwich panel having low heat release and low smoke release during combustion, and a prepreg using the same, and a honeycomb sandwich panel. Providing a laminate.

[Means for Solving the Problems]

The first invention relates to a flame-retardant phenolic resin composition,
Its characteristics are as essential components: (a) Crosslinking index is 60 or more and free phenol index is
A thermosetting phenolic resin of 30 or less, (b) a polyvinyl butyral resin having a polymerization degree of 1500 or more, (c) a 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 formula: (In the formula, n is 0 to 2) and a brominated bisphenol A derivative represented by: and (d) antimony pentoxide.

A second invention relates to a prepreg using a flame-retardant phenolic resin composition, which is characterized in that the base material is impregnated with a synthetic resin, wherein the synthetic resin is flame-retardant according to the first invention. It consists of a phenolic resin composition.

A third invention relates to a honeycomb sandwich panel using a flame-retardant phenolic resin composition, which is characterized by a honeycomb sandwich panel in which a prepreg obtained by impregnating a base material with a synthetic resin and a honeycomb core are laminated and bonded. In the above, the synthetic resin comprises the flame-retardant phenolic resin composition of the first invention.

A fourth invention relates to a laminated board using a flame-retardant phenolic resin composition, which is characterized by a laminated board formed by laminating prepregs obtained by impregnating a synthetic resin into a base material,
The synthetic resin comprises the flame-retardant phenolic resin composition of the first invention.

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 determined by a gas 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 examples thereof include resoles. Among them, the crosslinking index is 60 or more, and 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.

In the present invention, a granular or powdered special phenol resin (for example, trade name “Bellpearl” manufactured by Kanebo) or novolac may be used in combination with the resole. Also in this case, the thermosetting phenolic resin as a whole needs to have the crosslinking degree index and the free phenol index within the above-mentioned specific ranges.

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 pentoxide used in the present invention is not particularly limited as long as it is dispersed in the resin composition, but usually,
The particle size is from 0.1 to 10 μm, preferably from 0.5 to 5 μm. Above all, a colloid type of antimony pentoxide having a stable hydrophilic property or hydrophobic property to improve the dispersibility is preferable. Naturally, the resin composition using this type of antimony pentoxide has good dispersibility and is hard to settle, and even if it settles, it can be easily restored to the original dispersed state with a slight stirring.

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

Examples of the organic solvent used in the present invention include alcohols, ethers, ketones, amides, and mixed solvents of two or more thereof. 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 ester of ethyl carbitol, butyl carbitol. The acetic acid ester, dimethylformamide, dimethylsulfoxide or a mixed solvent of two or more thereof are suitable.

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, 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 30% by weight of the solid content. If it is less than 0.1% by weight, the heat release will be large and 3
If it is more than 0% by weight, the smoke release becomes large.

The component ratio of antimony pentoxide is preferably 0.1 to 30% by weight, more preferably 1 to 15% by weight. If it is less than 0.1% by weight, the heat release is large and the flame retardancy becomes insufficient, and if it is more than 30% by weight, the fluidity becomes poor.

The amount of the solvent may be selected according to the use of the composition of the present invention. For example, in the case of prepreg use, solid content / solvent = 5 /
It can be 95-80 / 20.

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

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 pentoxide was added to the obtained solution, and the mixture was vigorously stirred with a homodisper or the like to be uniformly dispersed, to obtain the flame-retardant 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. Moreover, a laminated board can be obtained by stacking a plurality of the obtained prepregs and heating under pressure.

〔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

In addition, a laminated board can be obtained by stacking and fixing the prepregs.

The resulting 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 and the core.

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.

In addition, the prepreg of the present invention can be used in applications such as laminated boards and FRP, and is extremely useful.

Further, in the present invention, when an antimony pentoxide that has been subjected to a surface treatment to improve dispersibility is used, each component, in particular, antimony pentoxide is excellent in dispersion stability and has good dispersibility even after a long time. Can be maintained.

〔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]

US Federal Standard FAR (Federal Acquisition Regulation) 2
The heat release of the sandwich panel measured according to 5.853 (A) was evaluated by the total value for 2 minutes and the peak value for 5 minutes.

[Smoke release]

A D _S value in sandwich panel measured at frame method NBS method (ASTM-E-662). 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-401B method).

[Resin Solid Content] Resol resin Eg (about 0.5 g) is placed in an aluminum cup and cured at 150 ° C. for 1 hour in an oven. [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 BRS325 (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,
Degree of polymerization 2400, carboxyl modified type, 10% MEK solution) 50 parts, brominated phenol derivative, prasefty EB20
7.8 parts of 0B (manufactured by Manac, dibromophenol monoepoxy derivative, Br content of 51%) was put into a dissolution vessel equipped with a cooling jacket and a homodisper, and dissolved by stirring.
Next, antimony pentoxide (trade name: Sun Colloid AME-13
0, surface-treated product, Nissan Chemical Industries, 30% MEK solution) 17.7 parts were added, and the mixture was stirred and dispersed. Finally, the concentration was adjusted with methyl ethyl ketone. The viscosity of the obtained resin composition is 10
The solid content concentration was 0 cps and 38.5% by weight. This resin composition was impregnated into glass cloth, KS181 / S920NM (made by Kanebo Co., Ltd.), and dried by a dryer at 70 ° C for 20 minutes and further at 90 ° C for 20 minutes to give a resin adhesion amount of 42% by weight and a volatile content of 2.5% by weight. I got a prepreg of.

Next, the obtained prepreg is a honeycomb made of Nomex,
Stick on both sides of SAH1 / 8-3 (Showa Aircraft Industry),
A honeycomb sandwich panel was manufactured by raising the temperature from room temperature to 127 ° C. in a vacuum bag at a pressure of 3.5 kg / cm ² for 60 minutes, keeping it for 1 hour, and then cooling. The heat release, smoke release and drum peel strength of the obtained honeycomb sandwich panel were 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 4 Instead of the phenolic resin used in Example 1, phenolic resins having different crosslinking index and free phenol index, Shonor BRS324 (manufactured by Showa High Polymer, solid content concentration 57
%), Shonor BLS352 (Showa High Polymer, solid content concentration
51%), SHOUL BRS310S (Showa High Polymer, solid content 62.5%) 104 parts, and Shonor BRL274 (Showa High Polymer, solid content 67.5%) 44 parts were used in the same manner as in Example 1. Then, a resin composition, a prepreg and a honeycomb sandwich panel were prepared.

The resulting honeycomb sandwich panel has heat release, smoke release and drum peel strength of 1st
As shown in the table, heat release and smoke release tended to increase as the degree of crosslinking decreased or the free phenol index increased, and the drum peel strength tended to decrease. This tendency was the same when two types of phenolic resins were mixed.

Comparative Example 1 Instead of the phenol resin in Example 1, a phenol resin having a low degree of crosslinking index and a high free phenol index, Shonor CKS343 (manufactured by Showa High Polymer, solid content concentration 46
%) Was used in the same manner as in Example 1 to produce 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. 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 5 The amount of polyvinyl butyral resin in Example 1 was set to 100.
A resin composition was prepared in the same manner as in Example 1 except that the parts were changed.
A prepreg and a honeycomb sandwich panel were obtained. The results are shown in Table 2, and although the adhesiveness was further improved, the viscosity of the resin composition was slightly increased.

Example 6 Instead of the polyvinyl butyral resin in Example 1,
Non-carboxyl modified 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 7 to 8 Instead of the brominated phenol derivative in Example 1, 7.0 parts of Pyrogard 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.
(Manac, decabromodiphenyl ether, Br content
82%) was used, the impregnating property of the resin composition into the prepreg was poor and only a poor appearance was obtained, and the fluidity was insufficient, and molding could not be performed smoothly.

Examples 9 to 10 Instead of the antimony pentoxide used in Example 1, 17.7 parts of Sun colloid AMT-130 (manufactured by Nissan Chemical Industries, surface-treated product, 30% methanol solution) or Sun Epoch EFR-6NJ (Nissan Chemical Co., Ltd.) A resin composition, a prepreg, and a honeycomb sandwich panel were prepared in the same manner as in Example 1 using 5.3 parts of an industrial product, an untreated product, a particle size of 1 μ powder).

The heat release, smoke release and drum peel strength of the obtained panel are as shown in Table 5, and the surface-treated product showed slightly better performance.

In addition, the resin composition using the untreated product caused a precipitate during storage, and it was necessary to stir and redisperse it before use.
On the other hand, the resin composition using the surface-treated product was able to be easily redispersed although it slightly settled during storage.

Example 11 The same method as in Example 1 except that carbon cloth, CF3101 (produced by Kanebo) was used instead of the glass cloth in Example 1 and the resin adhesion amount 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 6, 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 7.

Example 12 Six prepregs obtained in the same manner as in Example 1 were laminated and heated and pressed in a vacuum bag to produce a laminated plate. The pressurizing and heating conditions were such that the press pressure was 3.5 kg / cm ² , the press temperature was elevated from room temperature to 127 ° C. over 60 minutes, and kept for 1 hour.

The total heat release of the obtained laminate is 28 KW ・ mi.
n / m ² , peak is 26KW / m ² , smoke release has D _S value of 1
It was 0, and the laminate was excellent in flame retardancy.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location C08K 5/15 C08L 61/10 LMR 63/00 NJN // (C08L 61/10 29:04) 61 : 06 (56) Reference JP-A-60-161423 (JP, A) JP-A-60-58454 (JP, A) JP-A-60-58453 (JP, A)

Claims (4)

[Claims] 1. An essential component comprising: (a) a crosslinking degree index of 60 or more and a free phenol index of
A thermosetting phenolic resin of 30 or less, (b) a polyvinyl butyral resin having a polymerization degree of 1500 or more, (c) a 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 general 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 pentoxide. 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. 3. A honeycomb sandwich panel in which a prepreg made by impregnating a base material with a synthetic resin and a honeycomb core are laminated and bonded together, wherein the synthetic resin comprises the flame-retardant phenolic resin composition according to claim 1. Honeycomb sandwich panel characterized by that. 4. A laminate comprising laminated prepregs 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. Laminated board.