JPS6233873A - Full-aromatic polyamide fiber and fiber reinforced composite - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention provides a fully aromatic polyamide u1. with improved adhesion to a matrix resin. The present invention relates to fiber-reinforced resin composites using the fibers as reinforcing components.

Prior art poly(3,4'-oxydiphenylene terephthalamide)
p-phenylene terephthalamide) copolymer, poly(p-)
So-called "aramid fibers" made of wholly aromatic polyamides such as poly(rn-phenylene terephthalamide) and poly(rn-phenylene terephthalamide) have good +Ik mechanical properties and thermal properties. In combination with various matrix resins, it is widely used as a fiber-reinforced composite material in aircraft, space vehicles, automobiles, electronic equipment, etc. That is, the fiber-reinforced composite material can be used as a unidirectional prepreg, a laminate board using a careful method, a honeycomb board, a filament winding molded eyelid, a pultrusion molded product, or a FRT.
It is widely used in forms such as P.

However, these wholly aromatic polyamide fibers are chemically stable, that is, inert, and have a high non-electrosecondary transition point, so they are used as ma) It has been pointed out that there is no
・Ru.

However, although some methods have been proposed to improve the adhesiveness of fully aromatic polyamide fibers when used as reinforcing materials for rubber products (Japanese Patent Publication No. 53-37473), there are no methods for improving the adhesiveness of fully aromatic polyamide fibers to resins. An effective method for doing so is not yet known.

Object of the Invention The object of the present invention is to provide fully aromatic polyamide fibers with improved adhesion to resin, and fiber-reinforced resin composites with high tensile shear strength, interleaved l4i1 strength, etc., using the fibers as a reinforcing component. It's about offering your body.

Constituent Structure of the Invention In order to improve the electrical properties of wholly aromatic polyamide fibers with matrix resin, the surface of the fibers must have high affinity or reactivity with the wholly aromatic polyamide, and be modified to have high responsivity or reactivity with the matrix resin. It is considered that a method of forming a hidden layer having affinity is appropriate.

Therefore, as a result of extensive research, the present inventor has discovered that the present inventor has 0T ability to react with fully aromatic polyamide fibers, and
We focused on polyalkyleneimine compounds as compounds that have reactivity with the main matrix resins of epoxy resins, polyimide resins, unsaturated polyester resins, and phenolic resins. For example, polyethyleneimine has these properties and is thought to be able to improve adhesiveness.

However, such polylower alkylene imines have extremely high water permeability, and there is a concern that the resulting Jt layer will also be a layer with too high hydrophilicity.

Based on the above findings, the present inventors believe that as a result of thinning, the reactivity towards both fragments as described above can be maintained by using an adduct in which an oligoalkylene imine and an epoxy compound are reacted in advance. It was found that the balance between hydrophilicity and hydrophobicity was adjusted, and the affinity with epoxy resins and the like was also improved. As a result of further studies, we found that by covering fully aromatic polyamide fibers with the above-mentioned adducts, we were able to achieve a combination of the fibers and the matrix tree! R
The present invention was developed based on the recognition that the t-characteristics are the same as those described above.

That is, the present invention has the following features: (1) At least a part of the fiber surface is coated with an adduct of an oligoalkylene imine and an epoxy compound, and the flit property with Maddox resin is improved.
and (2) a wholly aromatic polyamide fiber in which at least a portion of the fiber surface is coated with one duct of an oligoalkylene imine and an epoxy compound as a reinforcing material. It is a fiber-reinforced resin composite with excellent mechanical properties.

In the present invention, the following repeating units (A) &
Or polyamide fibers consisting of (B) can be mentioned.

-Qtl-personr -00-NH-8r, -NH-...
・・・・・・・・・(N-OOA r 3N H-・・・・
(4 (λfl, 2, and r3 represent the same or different divalent 'jfIF group groups.) Such wholly aromatic polyamide fibers include, for example, polyamide fibers. (m-phenylene terephthalamide), poly(p-phenylene terephthalamide), poly(4,4'-biphenylene terephthalamide), poly(p-benzamide), poly(
3,4'-dioxydiphenylterephthalamide/p-)
Among them, poly(3,4'-2oxydiphenylterephthalamide/p-), which is classified as a so-called high Young's modulus and high strength fiber, can be mentioned. Unilene terephthalamide) copolymerized volume poly(p-) unilenterephthalamide) Jm is favorable.

On the other hand, in the present invention, an adduct of an oligoalkyleneimine and an epoxy compound is used as the coating component. The term "oligoalkyleneimine" as used herein mainly refers to those represented by the following general formula.

H2N-+几-NH+nWNH2 (However, in the formula, R and 几' represent at least one kind of fullkylene group having 2 to 5 carbon atoms, and m represents O or an integer of 10 or less.) Such oligoalkylene imine is , for example, the above m −0 to oligoethyleneimine such as ethylenediamine, diethylenetriamine, triethylenetriamine, tetraethylenepentamine, pentaethylenehexamine, etc.
1O oligomers or mixtures thereof are used.

In addition, similar propylene imine oligomers and N%N'
-bis(3-amylablepyr)ethylenediamine and the like can also be used.

Among the above oligoalkylene imines, m = 1
-4 oligoethyleneimines are particularly preferred.

In addition, as described below, in special cases, polyethyleneimine with a high degree of polymerization may also be included in the oligoalkyleneimine referred to in the present invention.

Epoxy compounds used to make adducts include addition reactions with oligoalkylene imines such as those mentioned above,
It is preferable to use an epoxy compound that can generate a tact of 7 tact, but in general, an epoxy compound containing 1 to 4 (especially preferably 2 to 3) epoxy groups in one molecule is used.

Specific examples of suitable epoxy compounds include the following, which may be used alone or in combination of two or more.

and suitenols/diglydyl ethers (including oligomeric diglydyl ethers in which bisphenols are linked with 2-hydroxytrimethylene diether or false) ethylene glycol diglycidyl ether polyethylene glycol diglycidyl ether glycerin diglycidyl ether Resorcin diglycidyl ether N, N'-diglycidyl hydantoin triphenylmethane triglycidyl ether triglycidyl isocyanate 9-7 minophenol N, N, 0-) diglycidyl tetraphenylethane tetraglycidyl ether N) N, N', N '-Tetraglycidyl methylene dianiline phenol novola, 2 glycidyl ether compound phenol glycidyl ether styrene oxide ethylene glycol monoglycidyl ether N-glycidyl phthalimide In particular, when an epoxy resin is used as the matrix resin, the epoxy compound of the resin It is preferable to appropriately select the epoxy compound used for adduct production in consideration of compatibility.

The secondary amino group reacts with one epoxy group and returns, so if you try to make an adduct by making the 7-mino group and the epoxy group equal equivalents, the amine will easily glue. The reaction must be carried out in a significant excess of groups.

In general, when the epoxy compound is a jepoxy compound, the oligofulkyleneimine is considered to be trifunctional and is combined with geboxy in y equimolar amounts. If the alkylene imine is considered to be monofunctional, it may be used after determining experimentally the ratio at which a soluble product can be obtained, ranging from a ratio that is equivalent to epoxy to a range in which epoxy is slightly excessive.

As a matter of course, it is preferable to carry out the reaction so that the oligoalkylene imine is constantly present in excess even during the course of the reaction, that is, to gradually add the epoxy compound to the oligoalkylene imine. More specifically, an adduct may be generated by gradually adding a solution or a finely powdered epoxy compound to an aqueous solution of oligoalkylene imines.

The reaction temperature is from room temperature to about 60°C. It is also possible to carry out the reaction at room temperature initially, and then gradually raise the temperature after the addition of the epoxy compound to complete the reaction.

When adding an epoxy compound that is insoluble in water, it may be used by dissolving it in a low boiling point solvent that mixes with water, such as methanol, ethanol, and 7-setone.

The produced adduct is generally water-soluble, and when coating fibers, the organic solvent can be distilled off beforehand.

Generally, the reaction concentration is 3 at the end of the reaction.
-20% by weight (particularly preferably 5-15% by weight).

Insoluble matter may be suspended in the solution, but in this case, F
You can use it as you see fit.

A common method for coating the surface of fully aromatic polyamide fibers with an adduct of oligoalkyleneimine and an epoxy compound is to prepare a soluble adduct in advance and attach it to the fiber surface in the form of a solution. However, as another method, first an oligoalkylene imine and then an epoxy compound are applied to the fiber surface (preferably in the form of a tack solution), and the adducts are produced directly on the fiber surface by dry heat treatment as appropriate. You can also take a method of coercion. In particular, the latter method can be preferably used when the adduct has a composition that is easily glued. In particular, in this case, high molecular weight polyalkyleneimine <*polyethyleneimine) can also be used in the same way as oligofulkyleneimine.

That is, in the latter method, an aqueous solution of oligoalkylene imine is applied to the surface of wholly aromatic polyamide fibers by spray, brush, roller, etc., or the fibers are immersed in the aqueous solution and then squeezed with a roller. Partial drying is performed with hot air, and then a solution of the epoxy compound (an aqueous solution is preferable, but if it is insoluble, a solution in a low-boiling organic solvent such as acetone, methanol, or ethanol may also be used) is applied as is or immersed in the same way. After that, a method can be adopted in which heat treatment is performed to obtain adduct-coated fibers.

However, as mentioned above, the method usually used is to apply the obtained adduct solution to the surface of the fibers using a spray, a roller, etc., or to immerse the fibers in the solution, squeeze the fibers, and then dry them immediately. It will be done.

As the solution, an aqueous solution or a solution dissolved in a mixture of water and a low-boiling organic solvent is used, and an aqueous solution is particularly preferred. The adduct concentration in the solution is suitably in the range of 0.5 to 10 times IL, preferably about 1 to 7 Nim%.

It is preferable that the adduct coating formed on the surface of the wholly aromatic polyamide fiber be as uniform as possible.

The coating amount is generally 0.1 to 10 times the weight of the fiber, and preferably 0.1 to 5 times the weight of the fiber.

The adduct aqueous solution can also be added to the fiber treatment oil and applied to the fibers simultaneously with the oil treatment of the fibers.

In the present invention, after the fiber surface is coated with the adduct, it is preferable to perform heat treatment before applying the matrix resin, and the heat treatment temperature is generally 150°C or less, preferably about 50 to 120°C.

In addition, in the present invention, after applying the above-mentioned adduct solution to the fiber surface, an epoxy compound bismaleimide compound, a polyester prevolamer having an unsaturated bond, a phenol resin,
By applying a resol or the like as a solution to the upper layer of the adduct layer, preferably before the adduct layer is completely dry, and forming a pre-cured layer in advance, the compatibility and reactivity with the matrix resin can be further improved. can be done.

Application of the matrix resin to the fully aromatic polyamide fiber coated with the above-mentioned adduct, shaping and curing can be carried out by a conventional method.

The morphology of the wholly aromatic polyamide fibers is strand or roving, unidirectionally aligned prepreg 1 woven fabric, knitted fabric, mat-like ##! It can take various forms depending on its use, such as fibers and short fibers. Further, the wholly aromatic polyamide fibers can be used in combination with other reinforcing fibers such as carbon fibers, silicon carbide fibers, glass 4 fibers, etc. in the form of a hybrid.

M) As mentioned above, major matrix resins such as epoxy resin, polyimide resin, phenol resin, and unsaturated polyester resin can be used for IJ sock resin.
Depending on the case, various elastomers can also be used.

The Mk (Mf) of the fibers used in the composite is 5 to 70% by weight, preferably 20 to 65% by weight, particularly preferably 4
A range of 5 to 60 filtration is used. ◇ Effects of the invention The wholly aromatic polyamide fiber coated with the above adduct according to the invention is a matrix resin, especially a thermosetting resin! A fiber-reinforced composite with good mechanical properties is formed due to good adhesion.

Various methods are available for measuring the unreliability of reinforcing fibers and matrix resin in composites, and measurement is possible using any of these methods. It is common practice to measure violence intensity, etc.

The fiber-reinforced composite obtained according to the invention is collapsed in both tensile shear strength and interlaminar shear peel strength,
It can be advantageously used in various forms such as aircraft, space models, automobiles, and alpha equipment.

The reason why coating with such an adduct improves the fiber-matrix resin adhesion is that the oligoalkyleneimine segment in the adduct has reactivity with the surface of the wholly aromatic polyamide fiber and the main matrix resin This is thought to be because both are reactive.

That is, the adduct has good reactivity with the epoxy resin,
Carry out an addition reaction. In addition, a polyamide resin containing a bismaleimide compound undergoes a Michael addition type reaction and a reaction in which an imide resin including a normal polyimide is ring-opened by an amino group. Furthermore, unsaturated polyesters have the possibility of undergoing a valley J4Jvc reaction by a Michael addition type reaction with maleic acidity and a fumaric segment, and a 7-midorisis into an ester group.

In addition, the epoxy compound residue in the adduct often has an effect of increasing the affinity with the matrix resin, and compared to the case where polyalkylene imine is used alone, the epoxy compound residue has an effect of increasing the affinity with the matrix resin. Since the water resistance decreases in the order of Al1, it is expected that the effect of improving the water resistance of the obtained fiber reinforced composite material is expected.

EXAMPLES The present invention will be explained with reference to Examples below.
The present invention is not limited in any way by these examples.

Example 1 Natra Echire/Pentamine 51it S a Degree of Water Center fF! While stirring L100 Jusaka part at 35 to 10℃, add 5 ml of bisphenol A-diglylylether type epoxy resin j1ji [j-pico-■) 828J (Yuka Shell ■Hanko) prepared in advance. 6 parts of concentrated methanol and IGO were gradually added. 2 o'clock+
+-1f L was mixed, filtered, and the amine epoxy adduct was dissolved as a homogeneous solution.

The amine epoxy adduct compound m? Poly(3,4'-oxy) diluted with methanol and prepared in a paper box to 1"m!-1,3% fQ, which was impregnated with fully aromatic polyamide fiber (Teijin ``HM ~ 50'') consisting of diphenylene terephclamide/p-phenylene terephthalamide) TX combination (copolymerization ratio 50150) and coated with a solution; After drying at 120°C for 2 hours, the amount of amine epoxy adduct deposited was 1.17, 31, and 2.17, respectively.
A fiber was obtained which had been subjected to surface waves of 5 to give a weight of 31% and a thickness of 4.02%. The break [fiber is made of epoxy resin material] IJ
Lux fat ("Ebiko") 828J ■ 100 double parts, "
Ebicure 2" ■ (4,4'-diaminodiphenylsulfone hardening agent) This prepreg is 14F! 1. MXd and fiber content (vf) using a heat press with the following curing conditions:
A unidirectional reinforced composite material plate with 60 stacked plates and dimensions of 127 mm x 12.5 m width x 2 dragon knobs is used.

Curing conditions Main curing: 160°C for 20 minutes Heat press force/reduction post-curing: 160°C for 2 hours Compensating pressure
Therefore, the short beam three-point bending (f″C interlayer shear 4fr strength) was measured.

The values are 7, 1 kg /
an”, 7.3 # / m2.7.1 kl /
It was an2. For comparison, the inter-helical shear strength of a composite conductive plate obtained in the same manner using yarn without any coating treatment was 6.4 h/an2, and the strength was significantly increased by the coating treatment. It was confirmed that there was an improvement in

Next, the above-mentioned composite material board using 2.17 mfi of fibers and, for comparison, a similar composite material board using completely untreated fibers were each heated 14 times in 6 liters of water. After taking out the treated bag and thoroughly wiping it with a piece of paper, Xt was measured, and the water absorber was measured based on the one piece before treatment.

For coated fibers, 2.55 weight) 1%, untreated J! l1
In the case of ffi fiber, it is 2.56 layers, and the coating treatment does not have any negative effect on water absorption, and therefore it is predicted that it has no effect on water resistance.

Example 2 Implementation ff1J In place of tetraethylenobentamine in 1, pentaethylenehexamine was used, and 10011
Example 91J was carried out in the same manner as in Example 1, except that the It part was replaced with 120 parts.
Similar to 1, this adduct copolymerizes fully aromatic polyamide! T! L fiber (kijin ■rHM-50J) k coated, adak) (t#to, 69 Arashi 1%, 2.83m consideration chi, 4.
41 coats of each treated fiber were obtained.

A unidirectionally reinforced composite board was made from the fibers and the strength of each layer was measured.

The values are 7.2.7.1.7 in the order of appendix a↑A above.
．． 3 and 2, and it can be seen that the atonement note has been changed in both cases.

In addition, the water absorption rate after 9 hours of water treatment as in Example 1 was 2.54% and 1%, which was not different from the untreated water absorption rate of 2.55It%. It is thought that there is no adverse effect on water resistance.

Then, 4 fibers of the same type were treated in the same manner as in Example except for 100% by weight of 115 parts by weight of a 5-9% methanol solution of a mixture of 50 mol of the same compound and 50 mol of triglycidyl isocyanurate. , Attached a way 3.l 5 *' A unidirectional Hakama composite material board was prepared in the same manner as in g1, and the strength Iα was measured. It showed a value of .5 Yu71m2.

Example 4 Instead of [Epicor] 828j■ alone in Example 1, an 81% concentration water m solution of glycerin diglycidyl ether 9
A unidirectionally reinforced composite material board was prepared in the same manner as in Example 1, except that a 51 pocket was used, using 11+ coated fibers with a coating amount of 2.1 east expansion. This '+' 41 itl cutting 4
A measurement of one-strong rebound showed a value of 7.2Y7m11.

Example 5 Instead of the copolymerized fully aromatic polyamide + i fiber of Example 1,
Example 1 except that poly-p-phenylene terephthalamide fiber (Kevlar 49 manufactured by DuPont) was used.
3.315 is the Q [fi 1 (
Similarly, unidirectionally reinforced composite material plate ft++f, knee o
Konomono i! 7.4 kg/1+m (7) layer 111'!
It gave 114% degree. The tentative strength of the composite material obtained from fibers that have been washed without any treatment is 411]
In comparison, the interlayer φi of the present invention is 1111'ftt.
If is improved by 1'4.

Claims (2)

[Claims] (1) A wholly aromatic polyamide fiber characterized in that at least a portion of the fiber surface is coated with an adduct of an oligoalkyleneimine and an epoxy compound. (2) A fiber-reinforced resin composite comprising, as a reinforcing component, a wholly aromatic polyamide fiber whose fiber surface is at least partially coated with an adduct of an oligoalkylene imine and an epoxy compound.