JP3354594B2 - Aminophosphazene epoxy resin curing agent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aminophosphazene epoxy resin curing agent capable of obtaining a cured epoxy resin having excellent flame retardancy and heat resistance.

[0002]

2. Description of the Related Art Epoxy resins are used for sealing materials, electric and electronic materials such as laminated boards, paints, adhesives for automobiles, ships, cans, and the like.
Widely used for civil engineering and building materials, composite materials for aerospace and space. As the curing agent for this epoxy resin, aliphatic amines, aromatic amines, polyamides, acids, acid anhydrides, and the like have been conventionally known. [Masaki Shinzumi, "Epoxy Resin Handbook" (1987) Nikkan Kogyo Shimbun).

[0003]

In recent years, among the above-mentioned uses of epoxy resins, in particular, electric / electronic materials, aviation /
In composite materials for space and the like, higher flame retardancy and heat resistance are required. Therefore, a brominated bisphenol A type epoxy resin having relatively excellent flame retardancy is used, and antimony trioxide or aluminum hydroxide is further added as a flame retardant so as to obtain higher flame retardancy. ing.

[0004] However, when antimony trioxide is used in combination, there is a problem that the arc resistance is lowered and the insulating property is deteriorated. On the other hand, when aluminum hydroxide is used, there is a problem that the mechanical properties are lowered. Further, the halogen compound-based flame retardant has a problem that toxic gas is generated during combustion.

[0005] In view of such circumstances, the present invention provides an aminophosphazene-based epoxy resin curing agent which can provide high flame retardancy and can provide an epoxy resin cured product having excellent physical properties such as heat resistance. It is an object.

[0006]

In order to achieve such an object, the present invention provides a method for producing N ₃ P ₃ (NH ₂ ) ₂ (O-φ
₂ ) ₂ (NHCH ₂ CH ₂ NH ₂ ) ₂ , N ₃ P ₃ (NH
-Φ ₁ -CH ₂ -φ ₁ -NH ₂ ) ₆ and N ₃ P ₃
(NH-φ ₂ ) ₃ (NH-φ ₁ -CH ₂ -φ ₁ -NH ₂ )
One Aminohosufa selected from a compound group consisting of ₃
Zen-based epoxy resin curing agent (However, in the formula, φ ₁ is in para position
Benzene ring which functional groups are added, respectively, phi ₂ is benzene
It is a ring. ) .

The epoxy resin which can be cured by the curing agent of the present invention includes bisphenol A type resin, bisphenol F type resin, bisphenol AD type resin, phenol novolak type resin, cresol novolak type resin, cycloaliphatic epoxy resin, glycidyl ester type resin. Any epoxy resin such as a resin, a glycidylamine-based resin, and a heterocyclic epoxy resin may be used.

The amount of the curing agent used is preferably about 0.1 to 1.5 equivalents as active hydrogen equivalent in the curing agent molecule per equivalent of the epoxy group of the epoxy resin. In addition to the curing agent of the present invention, an ordinary curing agent such as diaminodiphenylmethane may be used in combination, or a curing accelerator such as benzyldimethylamine may be used in combination.

Further, if necessary, a filler such as glass fiber, an antifoaming agent, a coloring agent and the like may be contained in the epoxy resin to be cured. When the curing agent of the present invention is used, it is not particularly limited, but is usually 50 ° C to 200 ° C.
The epoxy resin can be cured by heating to a temperature of ° C.

[0010]

When the epoxy resin is cured by using the above epoxy resin curing agent, the content of phosphorus and nitrogen in the cured epoxy resin obtained can be increased, and the epoxy resin is provided with flame retardancy. Is done. And since the said hardening | curing agent has a ring structure, the heat resistance of an epoxy resin is improved. Further, since the epoxy resin reacts with the epoxy and is cured by the amino group on the outside that is not bonded to phosphorus, the curing temperature may be relatively low.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail by comparing its embodiments with comparative examples. In Examples and Comparative Examples, “parts” indicate “parts by weight”, “φ ₁ ” indicates “benzene ring having a functional group at the para-position”, and “φ ₂ ” indicates “benzene ring”.

Example 1 A 2-liter four-necked round-bottomed flask was charged with 150 g (0.43 g).
Mol) of hexachlorocyclotriphosphazene,
After dissolving in 600 ml of diethyl ether, the mixture is cooled in a water bath, and stirred with 450% of 28% aqueous ammonia.
g (7.4 mol) was added dropwise. After the completion of the dropwise addition, the mixture was refluxed for 2 hours to react. After completion of the reaction, the diethyl ether layer was separated with a separating funnel, washed three times with water, and dried overnight over anhydrous calcium chloride. After drying, diethyl ether was distilled off with a rotary evaporator to obtain a white powder. The obtained white powder was refluxed with n-heptane for 2 hours, and then hot filtered and dried under reduced pressure.
7 g (40.4% yield) of 1,1-diaminotetrachlorocyclotriphosphazene was obtained. m. p. Is 164 ~
165 ° C.

5 g (0.0162 mol) of 1,1-diaminotetrachlorocyclotriphosphazene synthesized by the above method was placed in a 500 ml three-necked round bottom flask, dissolved in 50 ml of dioxane, and then 3.05 g of phenol was added. (0.0324 mol) and 4.92 g (0.0486 mol) of triethylamine in dioxane 5
This dioxane solution was dropped into the flask while stirring. After dropping, 70 ° C
And reacted for 2 hours. After the reaction, the generated triethylamine hydrochloride was filtered to obtain a colorless and transparent reaction solution (dioxane solution).

3.89 g (0.0668 mol) of ethylenediamine was placed in a 500 ml three-necked round bottom flask, dissolved in 50 ml of dioxane, and the reaction solution obtained as described above was added dropwise. After dropping, the mixture was stirred at 70 ° C. for 2 hours to be reacted. After the reaction, the produced ethylenediamine hydrochloride was filtered, dioxane was distilled off from the filtrate by a rotary evaporator, and diaminodiphenoxydi (2aminoethylamino) cyclotripheosphazene (N ₃ P ₃ (NH
_{2) 2 (O-φ 2} ) 2 (NHCH 2 CH 2 NH 2) 2)
Was obtained in an amount of 2.46 g (yield: 32.2%).

10 parts of bisphenol A-epichlorohydrin type epoxy prepolymer (Epicoat 828 manufactured by Yuka Shell Epoxy Co., Ltd.), and diaminodiphenoxydi (2aminoethylamino) cyclotripheosphazen obtained by the above method 6.27 parts were mixed, and after degassing, 80 ° C × 4
Precuring for 150 hours and post-curing for 4 hours at 150 ° C gave a cured epoxy resin. The resulting cured epoxy resin had a limiting oxygen index of 28.2, indicating flame retardancy. The dynamic viscoelasticity measurement results show that the peak temperature of the loss elastic modulus (E ″) is 170 ° C. and the peak temperature of the loss tangent (tan δ) is 182.
° C.

The curing behavior of the cured product up to the curing was measured by a rheometer (MR-300 Solkid meter manufactured by Rheology Co., Ltd.) at a heating rate of 3 ° C./min. As a result, curing started at 133 ° C., and the storage elastic modulus (G ′) reached an order of 10 ⁶ at 141 ° C.

Example 2 68.52 g (0.3456 mol) into a 1 liter four-necked round bottom flask equipped with a stirrer, a condenser and a dropping funnel.
Of diaminodiphenylmethane, 20.98 g (0.20 g
74 mol) of triethylamine, and dioxane 50
Dissolve in 0 ml. A solution prepared by dissolving 10 g (0.0288 mol) of hexachlorocyclotriphosphazene in 100 ml of dioxane was added dropwise with stirring, refluxed for 9 hours, and reacted by stirring. After the reaction, the produced triethylamine hydrochloride was filtered, and dioxane was distilled off from the filtrate obtained by a rotary evaporator, and the filtrate was concentrated to a solution of 50 ml.
The concentrated solution was poured into 500 ml of benzene, and the product was precipitated to give pale yellow hexa (4-
(4′-aminobenzyl) phenylamino) cyclotriphosphazene (N ₃ P ₃ (NH-φ ₁ -CH ₂ -φ _1-
NH _{2) 6)} was obtained 35.38g of (96.7% yield).

10 parts of bisphenol A-epichlorohydrin type epoxy prepolymer (Epicoat 828) and 5.63 of hexa (4- (4'-aminobenzyl) phenylamino) cyclotriphosphazene obtained by the above method.
After degassing, the mixture was precure at 80 ° C. × 4 hours,
Post-curing was performed at 0 ° C for 4 hours to obtain a cured epoxy resin.

The limiting oxygen index of the obtained cured epoxy resin was 26.3. The dynamic viscoelasticity measurement results show that the peak temperature of the loss elastic modulus (E ″) is 170 ° C. and the loss tangent (t)
An δ) peak temperature was 184 ° C. The curing behavior of the cured product up to curing was measured by a rheometer at a rate of temperature increase of 3 ° C./min. As a result, curing starts at 132 ° C. and at 145 ° C., the storage elastic modulus (G ′) is 10 ⁶
Reached the order.

Example 3 10 g (0.0288 mol) of hexachlorocyclotriphosphazene was placed in a 500 ml three-necked round bottom flask equipped with a stirrer, a condenser and a dropping funnel, and dissolved in 100 ml of toluene. Heat to 80 ° C. Then, 8.05 g (0.0864 mol) of aniline and 11.95 g (0.1181 mol) of triethylamine were added dropwise with stirring. After the dropping, the mixture was refluxed for 4 hours, stirred and reacted. After the reaction, the formed triethylamine hydrochloride was filtered, toluene was distilled off by a rotary evaporator, and the mixture was concentrated to a 20 ml toluene solution. Then, the mixture was left overnight to obtain 7.05 g (yield: 47.3%) of trianilinotrichlorocyclotriphosphazene as pale pink crystals. _{m. p.} it was 180~185 ℃.

In a 500 ml three-necked round bottom flask, 3.13 g (0.029 g) of diaminodiphenylmethane was added.
0 mol), 3.03 g (0.0299) of triethylamine.
Mol) was dissolved in 100 ml of dioxane. Then, 5 g (0.0097 mol) of trianilinotrichlorocyclotriphosphazene synthesized as described above was dissolved in 100 ml of dioxane and added dropwise. After the dropwise addition, the mixture was refluxed for 6 hours, stirred, and reacted.
After the reaction, the generated triethylamine hydrochloride was filtered, and dioxane was distilled off from the obtained filtrate with a rotary evaporator to give a pale yellow solid. N ₃ P ₃ (NH ₂ ) ₃ (NH
9.18 g (yield 94.7%) of -φ ₁ -CH ₂ -φ ₁ -NH ₂ ) ₃ (trianilinotri (4- (4'-aminobenzyl) phenylamino) cyclotriphosphazene) was obtained.

10 parts of bisphenol A-epichlorohydrin type epoxy prepolymer (Epicoat 828) and trianilinotri (4- (4'-aminobenzyl) phenylamino) cyclotriphosphazene (N ₃ P ₃ (NH-φ ) ₃ (NH-φ-CH ₂ -φ-N
H ₂ ) ₃ ) After mixing and degassing, 8.89 parts were pre-cured at 80 ° C. × 4 hours and post-cured at 150 ° C. × 4 hours to obtain a cured epoxy resin. The critical oxygen index of the obtained cured epoxy resin was 27.2. The dynamic viscoelasticity measurement results show that the peak temperature of the loss elastic modulus (E ″) is 168 ° C.
The peak temperature of the loss tangent (tan δ) was 180 ° C.

(Comparative Example 1) 10 parts of bisphenol A-epichlorohydrin type epoxy prepolymer (Epicoat 828) and 2.64 parts of diaminodiphenylmethane were mixed, and after deaeration, precured at 80 ° C for 4 hours and post-treated at 150 ° C for 4 hours. It was cured to obtain a cured epoxy resin. The critical oxygen index of the obtained cured epoxy resin was 25.0. The dynamic viscoelasticity measurement results show that the peak temperature of the loss elastic modulus (E ″) is 162 ° C.
The peak temperature of the loss tangent (tan δ) was 174 ° C.

The curing behavior of the cured product up to curing was measured by a rheometer at a rate of temperature rise of 3 ° C./min. As a result, curing started at 133 ° C., and the storage elastic modulus (G ′) reached an order of 10 ⁶ at 147 ° C.

(Comparative Example 2) 10 parts of bisphenol A-epichlorohydrin type epoxy prepolymer (Epicoat 828) and 1.30 parts of triethylenetetramine were mixed, and after deaeration, precured at 80 ° C for 4 hours and 150 ° C for 4 hours. Post cure was performed to obtain a cured epoxy resin. The critical oxygen index of the obtained cured epoxy resin was 21.1. As a result of the dynamic viscoelasticity measurement, the peak temperature of the loss elastic modulus (E ″) was 107 ° C., and the peak temperature of the loss tangent (tan δ) was 128 ° C.

(Comparative Example 3) Diaminotetraphenoxycyclotria was used as a curing agent.
Minophosphazene (N ₃ P ₃ (NH ₂ ) ₂ (O-φ ₂ )
₄ ) Using bisphenol A-epichlorohydrin type d
Curing of the epoxy prepolymer (Epicoat 828)
Curing behavior up to 3 ° C /
Measured in minutes. As a result, curing started at 191 ° C.
At 7 ° C, the storage modulus (G ') reaches the order of 10 ⁶
Was.

[0027] Examples 1 to 3 and Comparative Examples 1 and 2
Et al., The aminophosphazene-based compounds of the present invention. Poxy resin curing agent
The epoxy resin cured products of Examples 1 to 3 obtained by using
Excellent flame retardancy and heat resistance compared to the comparative example
You can see that. In addition, the above Examples 1 and 2 and Comparative
From Example 3, the same aminophosphazene-based epoxy resin curing
Agent, the aminophosphazene-based epoxy of the present invention
As with resin hardeners, outer
The structure is such that the amino groups react with the epoxy and cure.
It can be seen that the curing temperature is relatively low.

[0028]

Since the epoxy resin curing agent according to the present invention is constituted as described above, it is possible to obtain a cured epoxy resin having excellent properties such as high flame retardancy and heat resistance. Also, since it does not contain halogen, no toxic gas is generated during combustion. Therefore, electrical and electronic materials, paints,
An epoxy resin cured product that is effective for applications such as adhesives and composite materials can be provided. And it's not bound to phosphorus
Reacts with epoxy due to amino groups on the outside and cures
Therefore, the curing temperature may be relatively low.

──────────────────────────────────────────────────続 き Continued on the front page (72) Minoru Kayaki, Inventor 357, Kobe, Kishikawa-cho, Naga-gun, Wakayama Prefecture (72) Masami Iyo, 52-1 Kurumebe, Uchida-cho, Naga-gun, Wakayama Prefecture (72) Yoshio Horiuchi Wakayama, Inventor 247-1 Ichisankuzu (56) References JP-A-61-190522 (JP, A) JP-A-4-279625 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08G 59/50 C07F 9/659-9/6593

Claims (1)

(57) [Claims] (1)Formula N _Three P _Three (NH _Two ) _Two (O-φ _Two )
_Two (NHCH _Two CH _Two NH _Two ) _Two , N _Three P _Three (NH-φ
₁ -CH _Two −φ ₁ -NH _Two ) ₆ , And N _Three P _Three (N
H-φ _Two ) _Three (NH-φ ₁ -CH _Two −φ ₁ -NH _Two )
One aminophospha selected from the group of compounds
Zen epoxy resin curing agent (However, φ in the formula ₁ Is para
A benzene ring to which each functional group is added, φ _Two Is Benze
It is a ring. ).