JPH0284574A - Surface-modified wholly aromatic polyamide fiber - Google Patents

Abstract

PURPOSE:To obtain the subject fiber without any fluffing, scumming, etc., in twisting yarns, excellent in adhesion to resins and useful for FRP, etc., by adhering a cation exchangeable inorganic compound to the surface of a fiber and applying an oiling agent consisting of a specific alkylene oxide copolymer thereto. CONSTITUTION:The objective fiber obtained by spinning a wholly aromatic polyamide (e.g., copolyp-phenylene.3,4-oxydiphenylene.terephthalamide), washing the resultant fiber with water, applying an aqueous dispersion of a solid cation exchangeable inorganic compound (e.g., bentonite) to the fiber surface, drawing the fiber while heating and then applying an oiling agent composed of a random or block copolymer of propylene oxide and ethylene oxide with 400-800 average molecular weight at (70/30)-(0/100) copolymerization molar ratio to the fiber surface.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to wholly aromatic polyamide fibers (hereinafter referred to as aramid fibers) used in 1a fiber-reinforced resin materials (FRP).

<Prior art> Aramid fibers, a representative high-tech fiber, have recently been put into practical use as advanced composites in fields that require light weight, high strength, and high rigidity, taking advantage of their characteristics such as heat resistance, high strength, high modulus, and chemical resistance. It is being done.

However, in order for the fiber to function as a reinforcing fiber, the most important factor is the adhesiveness between the fiber and the matrix resin. The main matrix resins used here are epoxy, urethane, and epoxy acrylate.

By the way, in general, aramid fibers exhibit excellent strength in the fiber axis direction, but in the direction perpendicular to the fibers, fibrillation is likely to occur due to the orientation and crystallinity in the fiber axis direction being too high.
Also, the interfacial adhesion with other materials becomes low. Furthermore, compared to aliphatic amines, the aromatic amines constituting the aramid fibers have extremely weak basicity due to the influence of the phenyl group adjacent to the amino group, and therefore have weak reactivity with epoxy.

The oil for spinning aramid m-fibers inhibits the adhesion between the fibers and the matrix resin.

<Purpose of the Invention> The present invention satisfies the operability in subsequent processes such as spinning and twisting of aramid fibers when forming a composite material from aramid fibers and matrix resin, and also provides a composite material made of aramid fibers and a matrix resin. The purpose of this invention is to provide surface-modified aramid fibers that do not reduce the functionality of the material.

<Structure of the Invention> In other words, the present invention is based on ``a solid cation-exchangeable inorganic compound fixed to the fiber surface, and one type of random block copolymer of propylene oxide and ethylene oxide (hereinafter referred to as Pluronics) or A wholly aromatic polyamide fiber to which an oil agent composed of two or more types is attached, the copolymerization ratio of a copolymer of propylene oxide and ethylene oxide is 70/30 to O/100 (molar ratio), and the average molecular weight is 400-800, viscosity at 50℃ is 25c
``Surface-modified wholly aromatic polyamide fibers characterized by having a surface-modified fully aromatic polyamide fiber having a

Here, the copolymerization ratio of Pluronics is 70/30~0
/100 (molar ratio), especially 70/30 to 3
0/70 (mole ratio) is desirable 0 molar ratio is 70/3
If it exceeds 0, the water solubility of Pluronics decreases, resulting in poor solution stability.

The average molecular weight of Pluronics is 400-800.

If it is less than 400, smoke generation on the hot plates and heating rollers increases in the spinning process, deteriorating the working environment, and increasing stick-slip due to oil film rupture under high contact pressure, resulting in fuzz generation.

If it exceeds 800, the viscosity of the oil increases, which promotes the formation of sticky scum on the yarn guiding guide, which has a particularly low roughness, and causes frequent fluffing during long-term running.

The viscosity at 50"C is 25C3t or less, preferably 5 to 25cst. The viscosity was measured at 50C using a Canon Fenske.

If Pluronix has a viscosity of 5 cst and is not grooved, a lot of smoke will be emitted on the hot plates and heating rollers during the spinning process, leading to a deterioration of the working environment.If the viscosity exceeds 25C3t, the coefficient of friction against metal will increase and the winding machine will Fixed guides with low surface roughness, such as traverse hook guides and traveler guides, generate fuzz when bent and rubbed.

The copolymerization form of Pluronics may be either a block polymer or a random copolymer. It is desirable to include a block copolymer from the viewpoint of the effect of lowering the surface tension of the aqueous dispersion. Alcohols or basic acids are used as the initiator for Pluronics. .

The amount of the treatment agent applied is preferably in the range of 0.5 to 5.0% by weight, particularly preferably 1.0 to 3.0% by weight, from the viewpoint of operability from the spinning process to the post-processing process and improvement of adhesiveness with the resin. It is 5% by weight.

If it is less than 0.5% by weight, the lubricity and the cohesiveness of the fiber threads will decrease. If it exceeds 5.0 weight and 1%, product stains will occur due to oil seepage.

The pluronics of the present invention (1) plays the role of an oil agent in the yarn spinning process and then decomposes and volatilizes on a heating roller or hot plate, so that only a viscosity that does not impede adhesion remains in the stretched yarn.

(2) The coefficient of friction against metal is reduced to a large rl.

(3) It has excellent compatibility and diffusivity with epoxy resin, urethane resin, or epoxy acrylate resin, so it does not intervene at the interface between aramid fibers and matrix resin during composite molding, so it is easy to bond aramid l fibers and matrix resin. It does not interfere with sexuality.

Epoxy resins used include, for example, bisphenol A type epoxy resin, novolac type epoxy resin, and polyglycol type epoxy resin.

Bisphenol F type epoxy resin, triglycidyl-P
High molecular weight epoxy resins such as aminophenol type epoxy resin, polynuclear phenol/glycidyl ester type epoxy resin, tetraglycidyl methylene dianiline type epoxy resin, triazine type epoxy resin, triglycidyl isocyanurate, glycerin triglycidyl ether,
N-butyl glycidyl ether, 2.6- (2,3
- low molecular weight epoxy resins such as phenyl glycidyl ether (epoxy dipropyl), etc. The epoxy resin curing agents used in combination include aliphatic polyamines, polyamide resins, etc. as room temperature curing agents, and aromatic diamines, tertiary amines, amine salts, imidazole acid anhydrides, etc. as high temperature curing agents. The epoxy acrylate is an ester of bisphenol A type epoxy resin and acrylic acid, and the curing catalyst is dialkyl dicarbamate, benzoyl peroxide, t-butyl perbenzoate, or the like.

The aramid fiber of the present invention is copolyvararphenylene 3
.

Alternatively, the surface of the m-fiber may be plasma-treated.

<Effects of the Invention> 1. There are no operational problems such as smoke generation due to heat treatment, fuzz and scum generation due to friction with various guides during the yarn twisting process.

2. Since the Pluronics of the present invention is compatible with the matrix resin, there is no untreated residue left at the interface between the resin and fibers during the Breeprig stage, and the binding effect between the resin and aramid fibers is more effectively exerted. Improves adhesion.

Hereinafter, the manufacturing method of the present invention will be specifically explained with reference to Examples.

<Example> Aramid consisting of terephthalic acid dichloride, P-phenylene diamine, and 3,4°-diaminodiphenyl ether was spun into a fiber bundle of 1500 denier/1000 filaments, and washed with water for 1! Then, after washing with water, a bentonite aqueous dispersion was applied and the film was stretched at a high temperature of 500'C. The amount of bentonite fixed was 0.42%.

As for the oil agent, a 20% concentration aqueous emulsion oil agent was applied at the level shown in Table 1 so that the amount of 0PU was 1.5%. The strength of the obtained fiber was 27 g/de, and the elongation was 4.9%.
Met. In the Examples, yarn spinning stability and other evaluations were carried out by the following methods.

Evaluation 3. Adhesion (interlaminar shear strength; abbreviated as ILSS) evaluation method 1. Silk spinning stability (fluff) After 5 hours of continuous spinning at a winding speed of 300 m/min, the surface fluff of the rolled cheese was evaluated.

Epicote 828 Evomate B001 Evaluation method 2. Silk spinning stability (smoking) 5 hours after the start of running, the state of smoke was visually judged on a heating roller set at 180°C. 6 Bunacol EX-703 Glycidyl The fibers were immersed in the above epoxy resin and oriented in one direction. Hardening treatment was performed while the sheets were aligned. The curing conditions were as follows: After being left at room temperature for 48 hours, after being cured under pressure at 120°C for 2 hours,
Further, post-curing treatment was performed at 180°C for 1 hour.

A test piece with a length of 20 inches, rl 6 m+, and thickness of 3 cm was prepared from the molded product thus obtained (fiber content 60%), and the span spacing was Interlaminar shear strength (ILSS, unit: kIr/-) was measured in 13 cities at a crosshead speed of 1.0 mi/min.

As shown in Table 1, it can be seen that when the surface-modified aramid fibers of the present invention are used, clearly excellent spinning properties and molded product quality can be obtained.

table The stability of this emulsion is poor. hand Continued Neho 1 book October 1986 1ma1ko'1r1°Mr. 1.Display of the incident special request Tte 2. Name of the invention Surface-modified wholly aromatic polyamide fiber (1) The scope of the claims is on the attached sheet.

(2) The statement "...on the inorganic compound..." on page 3, line 12 of the specification was deleted, and replaced with "...on the surface of the aromatic polyamide fiber..." Insert.

(3) Delete the statement "One or more types of..." on page 3, lines 14-15 of the specification.

(4) Statement on page 10, line 4 of the specification [Evomate 80
02..." is corrected to "Epomate BOOIW...J.

(5) Description on page 10, line 8 of the specification “Epomate BO
Correct O1J to "Epomate BOOI Oath".

(6) Statement on page 10, line 10 of the specification “Bunacol E
X-703..." to "Bunacol EX-191...
” he corrected.

(7) Description 6 on page 10, line 11 of the specification, contents of amendment ○ ” I am corrected.

(Attachment) Scope of claims! An aromatic polyamide fiber having a cation-exchangeable inorganic compound fixed to the surface of the fiber, and an oil agent composed of a random or block copolymer of propylene oxide and ethylene oxide attached to the surface of the aromatic polyamide fiber. and the copolymerization ratio of the copolymer of propylene oxide and ethylene oxide is 70/30-0/
100 (molar ratio).

A surface-modified aromatic polyamide fiber having an average molecular weight of 400 to 800.

Claims (1)

[Claims] (1) Whole aromatic fragrance in which a solid cation-exchangeable inorganic compound is fixed to the fiber surface and an oil agent composed of one or more random or block copolymers of propylene oxide and ethylene oxide is attached to the inorganic compound. group polyamide fiber, the copolymerization ratio of the copolymer of propylene oxide and ethylene oxide is 70/30 to 0/
100 (mole ratio), average molecular weight 400-800, 50
A surface-modified wholly aromatic polyamide fiber having a viscosity of 25 cst or less at °C.