JPS621626B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel aromatic polyamide fiber-reinforced ionomer resin composition obtained by adding fibers whose surfaces have been modified by N-substitution reaction to an olefinic ionomer polymer. As heat-resistant polymers, so-called fully aromatic polyamides, in which all of the divalent hydrocarbon groups bonded through amide bonds are aromatic cyclic groups, are being used practically as fibers, films, etc., and are attracting attention. This is known. Among them, according to Japanese Patent Publication No. 47-2489 and others, molded products such as fibers and films made of para-oriented wholly aromatic polyamides whose aromatic cyclic groups are represented by paraphenylene groups have high strength, high elastic modulus, and excellent properties. Due to its heat resistance, it is useful in a variety of applications. In particular, fibers are added to various thermoplastic resins and thermosetting resins as reinforcing fibers due to their properties of high strength and high elastic modulus, and the mechanical properties, heat resistance, etc. of the compositions are being studied. For example, Tokko Akira
No. 47-51829, Special Publication No. 52-500, Journal of Polymer Engineering Science, Vol. 14, p. 633 (1974), Journal of Applied Polymer Science, Vol. 20, p. 435 (1976) ),
Rubber Chemical Technology Magazine, Volume 50,
See page 945 (1977)]. However, this composition has poor adhesion between the para-oriented wholly aromatic polyamide fibers and the matrix resin, and does not exhibit good mechanical properties and heat resistance.
Furthermore, para-oriented wholly aromatic polyamide has a high affinity between self-molecules, so it tends to aggregate when mixed with a matrix resin, and has the disadvantage that it is difficult to obtain a composition in which fibers are uniformly dispersed. In view of these current circumstances, the present inventors have conducted extensive research and found that the above problems can be solved by modifying the surface of para-oriented wholly aromatic polyamide fibers by N-substitution reaction, and have thus arrived at the present invention. That's what I did. That is, the present invention comprises 40 to 99.9 parts by weight of an olefinic ionomer polymer and a compound having the general formula -NH- _Ar1-
NH−CO−Ar ₂ −CO− and/or −NH−
The surface of the para-oriented wholly aromatic polyamide fiber consisting of repeating units Ar ₃ −CO− has the following Q ₁ to
This is an aromatic polyamide fiber-reinforced ionomer resin composition comprising 60 to 0.1 parts by weight of fibers modified by N-substitution with one or more groups selected from the group _Q6 . Q ₁ =-C _k H _2k+1 , Q ₂ = (-CH ₂ ) _-l Ar ₄ ,

[Formula] Q ₄ = (−CH ₂ )− _o COOM,

【formula】

[Formula] (In the above formula, Ar ₁ , Ar ₂ and Ar ₃ each independently represent a divalent para-oriented aromatic group, k, l, m, n,
i, j are arbitrary integers, and Ar ₄ is

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

Aromatic groups selected from [Formula], R ₁ , R ₂ , R ₃ , R ₄ are the same or different -
NH _{, -CH3} , _{-CH2CH2 , -C2H5} , _{-C3H7 ,}

【formula】

[Formula] -CH2 _- O- _CH2 -CH= _CH2 , M represents -H or an alkali metal selected from Li, Na, K, Rb, and Cs. ) The olefin-based ionomer polymer used in the present invention includes a copolymer of one or more olefins and an unsaturated carboxylic acid, with some or all of the carboxyl groups neutralized with metal ions. be able to. Typical examples of olefinic ionomer polymers include ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-itaconic acid copolymer, ethylene-maleic acid copolymer,
Carboxylic acids such as ethylene-fumaric acid copolymer, ethylene-methacrylic acid-alkyl methacrylate copolymer, and ethylene-acrylic acid-alkyl methacrylate copolymer are alkali metal ions such as Li, Na, and K, or Mg Examples include those neutralized with alkaline earth metal ions such as , Ca, and Zn. The para-oriented wholly aromatic polyamide used in the present invention is a divalent para-oriented aromatic group, that is, the divalent bonding groups are 1,4-phenylene, 4,4'-biphenylene, 1・Like 4-naphthylene, coaxially opposite direction from the aromatic ring,
Or it consists of groups arranged in opposite directions along parallel axes, such as 1,5-naphthylene and 2,6-naphthylene. Examples of its structures include polyparabenzamide, polyparaphenylene terephthalamide, poly-4,4'-diaminobenzanilide terephthalamide, poly-N/N'-p-phenylene bis(p
-benzamide) terephthalamide, polyparaphenylene-2,6-naphthalitukuamide, copolyparaphenylene/4,4'-(3,3'-dimethylbiphenylene)-terephthalamide, copolyparaphenylene/2 -5-pyridylene-terephthalamide, copolyparaphenylene-isocincomelonamide/terephthalamide, etc. The method for producing fibers from these para-oriented wholly aromatic polyamides is not particularly limited in carrying out the present invention. The method for producing these para-oriented wholly aromatic polyamides is not limited in carrying out the present invention, and for example, from the corresponding diamine and diacid chloride,
It can be easily produced by the low-temperature solution polymerization method known from Publication No. 14399 and the like. The para-oriented wholly aromatic polyamide fiber used in the present invention is disclosed in Japanese Patent Publication No. 42-815, Japanese Patent Publication No. 50-12485,
Further, high modulus fibers can be produced by methods described in Japanese Patent Publications No. 50-12006, Japanese Patent Publications No. 47-39458, etc.; It can be manufactured by the method described in each publication such as No. Commercially available products include DuPont's Kepler 29 and Kepler 49 (both trademarks of DuPont and called PPTA fibers). The brand of para-oriented wholly aromatic polyamide fiber used in the present invention is not particularly limited, and can be arbitrarily set depending on the intended use, such as the number of fibers, total denier, etc. Microfibrils obtained by dropping a concentrated sulfuric acid solution into water under high-speed stirring or into water under ultrasonic action [see Kobunshi Ronshu, Vol. 34, p. 129 (1977), etc. ] can also be used as reinforcing fibers. Modification of the surface of the para-oriented wholly aromatic polyamide fiber of the present invention by N-substitution reaction can be carried out by the method described in Japanese Patent Application No. 116970/1983 by the present inventors. That is, the para-oriented wholly aromatic polyamide fibers described above are mixed with sodium or sodium hydride, or with DMSO in dimethyl sulfoxide (hereinafter abbreviated as DMSO) and/or hexamethylphosphoramide (hereinafter abbreviated as HMPA). and/or N-sodification of the surface layer in the presence of reactants with HMPA,
Then, the general formula Q′ ₁ =X−C _k H _2k+1 , Q′ ₂ =X(−
CH ₂ ) − _l Ar ₄ ,

[Formula] Q′ ₄ =X(−CH ₂ )− _o COOM,

【formula】

The reaction may be performed with one or more compounds selected from the group Q' ₁ to Q' ₆ represented by the formula (in the above formula, X is a halogen selected from chlorine, bromine, or iodine). (others are as above). DMSO used in carrying out this reaction
It is preferable that HMPA is used after being subjected to pretreatment such as purification and dehydration if necessary, and it is also possible to include first and second solvents that do not inhibit the reaction. The temperature and time of the reaction are also not particularly limited, and generally a temperature between 0°C and the boiling point of the system, particularly between 10 and 50°C, is preferably used, and a suitable time is about 1 minute to 10 minutes. The compounds represented by the general formulas Q' ₁ to Q' ₆ for introducing the surface-modifying substituents of the present invention are compounds corresponding to the above-mentioned substituents Q ₁ to Q ₆ , respectively, and Q As the halogen groups for ' ₁ , Q' ₂ , Q' ₄ and Q' ₆ , chlorine or bromine is generally used, but depending on reactivity etc., iodine compounds can also be used. The epoxide compound represented by the general formula Q' ₃ gives Q ₃ , which is a graft product, through a ring-opening reaction. Specific examples of combinations of R ₁ to _{R 4} are shown in the following table.

[Table] Furthermore, the compound represented by the general formula Q' ₅ is acrylonitrile, and gives Q ₅ through a graft reaction. As is clear from these reaction examples, para-oriented wholly aromatic polyamide fibers are treated with DMSO and/or
N-sodiumated wholly aromatic polyamide fibers reacted with sodium or sodium hydride, or their reaction products with DMSO and/or HMPA in HMPA, the polyamide in the surface layer is N-sodiumated, Reacts with a wide range of reagents, including but not limited to the N-substituents listed above.
It is easily understood that it is useful as a precursor fiber that can be modified and modified in a wide range. The characteristics of the resin composition of the present invention will be described below. General formula Q ₁ =-C _k H _2k+1 and/or Q ₂ =(-
The surface-modified para-oriented fully aromatic polyamide fibers with groups represented by CH ₂ ) _-l Ar ₄ disperse extremely well in ionomer resins, and have the characteristic of being uniformly dispersed even when the amount added is small. has.
Also, the general formula

[Formula] Q ₄ = (- CH ₂ ) - _o COOM,

[Formula] and and/or

The fiber whose surface has been modified with the group represented by the formula has extremely good adhesion with the ionomer resin, and the resin composition of the present invention has mechanical properties such as tensile strength, tensile modulus, and bending strength. It has the characteristics of significantly improving properties and heat resistance. The surface-modified para-oriented wholly aromatic polyamide fiber content in the resin composition of the present invention is 0.1
~60% by weight, more preferably 1~40% by weight. If the content of the polyamide fiber in the resin composition of the present invention is less than 0.1%, it is not preferable because no substantial effect as a reinforcing material is observed. In order to exhibit the characteristics of the present invention, at least 0.1% by weight,
Preferably 1% by weight of the polyamide fibers is required. If the amount of the polyamide fibers added increases, the molding processability will be significantly reduced, so the limit of the amount added is 60% by weight, preferably up to 40% by weight. The resin composition of the present invention may be mixed by any method, such as an extruder, a heating roll,
A melt mixing method using a Banbury mixer, a kneader blender, etc., a solution method in which the ionomer polymer is dissolved in a solvent, and the polyamide fiber is added thereto, etc. are used. The resin composition of the present invention may also contain glass fibers, carbon fibers, whiskers, glass beads, mica, asbestos reinforcements and/or other additives for special purposes, such as pigments, flame retardants, stabilizers. ,
It is also possible to contain a mold release agent and the like. EXAMPLES Hereinafter, in order to further clarify the present invention, the present invention will be described using Examples, but the scope of the present invention is not limited by the Examples. In addition, in the examples, parts indicate parts by weight. Example 1 3.6 g of sodium hydride was added to 1000 g of dimethyl sulfoxide (DMSO), heated at 70°C for 1 hour to completely dissolve, and then cooled to 30°C. Polyparaphenylene terephthalamide (hereinafter abbreviated as PPTA) fiber 10 with a diameter of 12 μm and a length of 5 mm
g was added to the above DMSO system and stirred at 30°C for 1 hour. Next, add 10g of monochloroacetic acid and heat at 50°C.
After reacting for 3 hours, a small amount of water was added to stop the reaction, and the fibers were separated using a glass filter. The fibers were washed three times alternately with acetone and water and then dried under vacuum at 40°C. In order to confirm the surface reaction of the fiber, the fiber was immersed in concentrated sulfuric acid to dissolve the surface layer, and then the sulfuric acid solution was poured into a large amount of water to precipitate the dissolved polymer. shows absorption of carboxyl group at 1750 cm ^-1 and N
-It was confirmed to be carboxymethyl-substituted PPTA. 3 parts of this surface-modified PPTA fiber and 97 parts of a resin in which the carboxylic acid of the ethylene-methacrylic acid copolymer was neutralized with sodium ions were mixed in a melt-kneader for 220 min.
After mixing at ℃, molding with a compression molding machine to a thickness of 0.4 mm.
A sheet-like sample was manufactured. As a result of a tensile test of this composition at room temperature, the yield strength was 335 Kg/cm ² ,
Tensile modulus is 7830Kg/cm ² , elongation is 27%, and
When measured at 80°C, the yield strength was 137 Kg/cm ² , the tensile modulus was 3180 Kg/cm ² , and the elongation was 160%. For comparison, a tensile test was also conducted on a resin composition containing 3% by weight of unmodified PPTA fibers. The results are shown in Table 1 (measured at room temperature) and Table 2 (measured at 80°C) together with the results of Example 1.

【table】

[Table] Example 2 Propylene oxide instead of monochloroacetic acid
Using 10 g, the surface was coated with N in the same manner as in Example 1.
-Propylene oxide graft modified
PPTA fiber is manufactured and 10 parts of this fiber is mixed with ethylene.
The carboxylic acid of the methacrylic acid copolymer was melt-mixed at 230°C with 90 parts of a resin in which the carboxylic acid was neutralized with zinc ions. The physical properties of this resin composition are yield strength: 1230Kg/
cm ² , tensile modulus of elasticity was 33500 Kg/cm ² , and elongation was 45%. The physical properties of the resin composition containing 10% by weight of unmodified PPTA fibers were a tensile strength of 740 Kg/cm ² , a tensile modulus of 16300 Kg/cm ² and an elongation of 65%. Example 3 In the same manner as in Example 1, epichlorohydrin 10
g was reacted at 20°C to modify the surface of the PPTA fiber. Five parts of this fiber and 95 parts of a resin in which the carboxylic acid of an ethylene-methyl methacrylate-methacrylic acid copolymer was neutralized with calcium ions were melt-mixed at 230°C. The physical properties of this fiber are yield strength 780
Kg/cm ² , tensile modulus of elasticity was 21000 Kg/cm ² , and elongation was 22%. The physical properties of the resin composition containing 5% by weight of unmodified PPTA fibers were a tensile strength of 420 Kg/cm ² , a tensile modulus of 9800 Kg/cm ² and an elongation of 90%. Example 4 In the same manner as in Example 1, 10 g of acrylonitrile
was reacted at 60°C to modify the surface of the PPTA fiber. 20 parts of this fiber and 80 parts of a resin in which the carboxylic acid of an ethylene-methacrylic acid copolymer was neutralized with potassium ions were melt-mixed at 230°C. The physical properties of this composition are yield strength 1860Kg/cm ² and tensile modulus
The weight was 36400Kg/cm ² and the elongation was 30%. The resin composition containing 20% by weight of unmodified PPTA fibers had a tensile strength of 1420 Kg/cm ² , a tensile modulus of 30300 Kg/cm ² and an elongation of 35%. Example 5 In the same manner as in Example 1, 5 g of n-stearyl chloride and 5 g of monochloroacetic acid were reacted at 40°C to modify the surface of PPTA fibers. Two parts of this fiber and 98 parts of a resin in which the carboxylic acid of an ethylene-isobutyl methacrylate-methacrylic acid copolymer was neutralized with magnesium ions were melt-mixed at 210°C. The physical properties of this composition include yield strength of 295Kg/cm ² ,
The tensile modulus was 6300 Kg/cm ² and the elongation was 95%. In addition, in the resin composition to which 2% by weight of unmodified PPTA fibers were added, the fibers were unevenly dispersed, making it impossible to measure the physical properties. Example 6 In the same manner as in Example 1, benzyl chloride 5
g and 5 g of epichlorohydrin were reacted at 20°C to modify the surface of the PPTA fiber. 230 parts of this fiber and 85 parts of a resin in which the carboxylic acid of the ethylene-methacrylic acid copolymer has been neutralized with lithium ions
Melt mixed at °C. The physical properties of this composition are yield strength 2090Kg/cm ² , tensile modulus 48600Kg/cm ² , and elongation.
It was 33%. For comparison, unmodified PPTA fiber 15% by weight
The physical properties of the resin composition added are tensile strength of 1170
Kg/cm ² , tensile modulus of elasticity was 24200 Kg/cm ² , and elongation was 40%. As specifically illustrated in Examples and Comparative Examples above, by applying the surface modification treatment that is a feature of the present invention, wholly aromatic polyamide fibers can be converted into resin without any surface modification that has been done in the past. It is clear that a significant reinforcing effect can be obtained compared to the case of blending. This is because the modification of the fiber surface increases the affinity with the resin and improves adhesive strength, and because of this affinity, wetting with the resin becomes better and the dispersibility of the fiber in the resin is improved. This seems to be due to the synergistic effect of

Claims (1)

[Claims] 1. 40 to 99.9 parts by weight of an olefin-based ionomer polymer and a compound having the general formula -NH-Ar ₁ -NH-CO-Ar ₂ -
The surface of the para-oriented wholly aromatic polyamide fiber consisting of repeating units of CO- and/or -NH-Ar ₃ -CO- is coated with one or more types selected from the group Q ₁ to Q ₆ below. An aromatic polyamide fiber-reinforced ionomer resin composition comprising 60 to 0.1 parts by weight of N-substituted fibers. Q ₁ = -C _k H _2k+1 , Q ₂ = (-CH ₂ ) - _l Ar ₄ ,
[Formula] Q ₄ = (-CH ₂ ) - _o COOM, [Formula] [Formula] (In the above formula, Ar ₁ , Ar ₂ and Ar ₃ each independently represent a divalent para-oriented aromatic group, k, l, m, n,
i and j are arbitrary integers, Ar ₄ is an aromatic group selected from [Formula] [Formula] [Formula] [Formula] [Formula] [Formula] [Formula] [Formula] [Formula], R ₁ , R ₂ , R ₃ , R ₄ are the same or different −
H, _-CH3 , -CH= _{CH2 , -C2H5} , _{-C3H7 ,}
[Formula] [Formula] -CH ₂ -O -CH ₂ -CH=CH ₂ A group selected from -H or an alkali metal selected from Li, Na, K, Rb and Cs. )