JPH02167339A - Modified rigid polymer and molecular composite material - Google Patents

Abstract

PURPOSE:To obtain a polyphenylene phthalamide-based polymer chemically bonding to a matrix resin and becoming a transparent useful composite material having excellent physical and chemical properties, having a specific structure. CONSTITUTION:A modified polyphenylene phthalamide-based polymer having at least 50% based on total amounts of repeating units shown by formula I and formula II (R1 and R2 are H, 1-20C alkyl and/or 2-20C aliphatic group or substituted aromatic group containing an olefin having polymerization activity, at least 5 % of R1 and R2 is group containing olefin having polymerization activity and <=20% of sum of R1 and R2 is hydrogen). The polymer has preferably 1,000-350,000 weight-average molecular weight, is soluble in a polymerizable monomer such as methyl methacrylate or styrene, has improved compatibility with and affinity for thermoplastic resin, thermosetting resin or rubber and is usable for strengthening and reinforcing a wide range of matrix resins.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a newly modified polyphenylene phthalamide-based rigid polymer, a method for producing the same, and a molecular composite material using the rigid polymer.

(Prior art) In the past, the development of composite materials that mutually complement the properties of the constituent materials and create new effective functions by combining two or more types of materials has been actively conducted. Regarding composite reinforcement with so-called high-strength fibers such as glass fibers, carbon fibers, and aramid fibers useful as reinforcement f'R#l, for example, elastic modulus, heat distortion temperature,! A wide range of performance improvements, including mechanical properties, have been reported and studied.

The present inventors N-alkylated the aramid bonds of the straight polymer of polyphenylene terephthalamide yarn according to Japanese Patent Application Laid-Open No. 61-227508, and uniformly dispersed the modified rigid polymer in the matrix of polymethyl methacrylate yarn resin. We proposed a dental material made of molecular composite materials.

(Problem to be Solved by the Invention) However, even when the organic polymer and the modified polyaramid are combined, the properties of the composite materials differ significantly, so the compatibility, adhesiveness, etc. It has the essential drawback that it has poor interfacial affinity, cannot exhibit sufficient composite effects, and also suffers from a decline in some of the physical properties inherent to organic polymers, such as toughness, and furthermore, the cured composition may be opaque. However, there were also problems in terms of water resistance and solvent resistance.

(Means for Solving the Problems) In view of the above-mentioned current situation, the present inventors have conducted intensive studies to solve the above-mentioned problems. Yu obtained a newly modified polyphenylene 7-talamide-based rigid polymer by introducing a functional group having a double bond at the N-position of a long-chain polyaramid directly connected to two aromatic rings. It was discovered that the modifier TiE polymer can be dispersed in molecular form in the IJ Lux resin2.
The present invention was completed based on the discovery that a new transparent composite material with excellent physical and chemical properties can be obtained by a cross-linked structure that is chemically bonded to a matrix resin.

That is, the present invention provides a modified rigid polymer R20 having at least 50 total repeating units represented by the following structural formula or and/or an aliphatic group or substituted aromatic group having 2 to 20 carbon atoms having an olefinic group having polymerization activity,
and at least five of the total of R1 and R2 are organic groups having an olefin group having polymerization activity, and R1 and R2
The purpose of the present invention is to provide a molecular composite material composition in which the modified polyaramid-based rigid polymer is uniformly dispersed in a matrix of 20% or less of the sum of 20% or less) and an organic resin.

All of the rigid t1f polymers of the present invention have the structural formula [1] or [2
], but it may also include other repeating units as long as it is 50 or less, and it is preferable that the other repeating units are 154 or less, More preferably, the number is 10 or less. Examples of such repeating units include aliphatic polyamides such as 6-nylon and 66-nylon.

R1 *R2 in formulas (■, ■) is hydrogen and has 1 to 2 carbon atoms
0, preference indicates an alkyl group having 5 to 20 carbon atoms, or an aliphatic group having 2 to 20 carbon atoms or a substituted aromatic group having an olefin group having polymerization activity, and an aliphatic group having an olefin group. The group preferably has 2 to 8 carbon atoms, and the substituted aromatic group having an olefin group has 8 carbon atoms.
-10 is preferred. Examples of the alkyl group include a pentyl group, a hekynyl group, an octyl group, a decyl group, an undecyl group, a dodecyl group, a tetradecyl group, a pentadecyl group, an octadecyl group, and the alkyl group may be linear or branched. Good too. Aliphatic groups having an olefin group include allyl group, 2-methylallyl group, n-
Examples include a butyl group, and examples of the substituted aromatic group having an olefin group include a styryl group and a styryl 1d-substituted alkyl group such as a styryl-substituted methyl group.

R1e R2 does not need to contain hydrogen, but
From the viewpoint of solubility, there is no particular problem as long as the total number of H crab Rt@R= is 20 or less, and it is preferably 104 or less.

In the present invention, the modified polyphenylene terephthalamide-based or polyphenylene metaphthalamide yarn rigid polymer obtained by substituting a functional group having a double bond at the N-position is, for example, the following general formula or In the presence of an alkali metal hydride, an aliphatic or substituted aromatic halide compound having 2 to 30 carbon atoms containing an olefin group having polymerization activity is added to a polyaramid-based rigid polymer having more than 50 or more repeating units in total. It can be produced by reaction. In this case, the halide compound may be reacted directly, but since the N-substitution reactivity of fully aromatic polyamides is generally low, the N-position is partially substituted with a predetermined amount of alkyl group in advance, and then reacted in a strong polar solvent. It is suitable to react the halide compound in the presence of an alkali metal hydride in order to carry out modification with a desired substitution rate.

As the strong polar solvent, dimethyl sulfoxide, N-methylpyrrolidone, dimethylacetamide, hexamethylphosphoramide, N, y, NHr-tetramethylurea, etc. are used, but dimethyl sulfoxide is particularly preferred. As the halide compound having a group, aliphatic halides or substituted aromatic halides having 2 to 20 carbon atoms are preferred in terms of reactivity and are therefore preferably used. Specific examples include chlorofuroben, chloromethylpropene, chlorobutene, chloromethylstyrene, chlorostyrene, bromobutene, bromostyrene, vinyl chloroacetate, and the like.

Further, the alkyl halide compound necessary for partial substitution with an alkyl group in advance is not particularly limited.
In particular, alkyl halides of 5 to 20 have good compatibility with the matrix resin and adhesive properties. Specific examples include chlorodeca/, chlorododecane, chlorooctadecane, bromohexane, bromooctane, bromodecane, bromododecane, bromotetradecane, bromopentadecane, and the like. The alkyl group may be either linear or monobranched.

The resulting modified polyphenylene phthalamide preferably has a weight average molecular Tt in the range of 1,000 to 350,000, and can be used not only in solvents such as chloroform, tetrahydrofuran, and carbon tetrachloride, but also in polymerizable solvents such as methyl methacrylate and styrene. It has improved compatibility and affinity with thermoplastics, thermosetting resins, and rubbers.
It can be used in a wide range of areas to strengthen matrix resins and as a reinforcing material. For example, specific examples of thermoplastic resins include polyacrylate, polymethacrylate, polymethyl methacrylate, methyl methacrylate/styrene copolymer, polystyrene thread, styrene/acrylonitrile copolymer, polyacrylonitrile, and styrene/acrylonitrile/butadiene. Examples include copolymer resins, among which (meth)acrylic resins are particularly preferred since they can form a molecular composite material with the above-mentioned modified polyphenylene terephthalamide or hapolyphenylene metaphthalamide. These monofunctional (co)! In addition to combining, depending on the purpose of use, the following formula ■ ○H, =, :0-co+aam, ca2yao-co-a
Ethylene glycol diacrylate and methacrylate, diethylene glycol diacrylate and methacrylate, triethylene glycol diacrylate represented by ■ (wherein R1 and R4 are H or a methyl group, and p is an integer of 1 to 20) and methacrylate, polyethylene glycol diacrylate and methacrylates, 1,4-butanediol diacrylate and methacrylate, 1,3-butanediol diacrylate and methacrylate, 1.6-
hexanediol diacrylate and methacrylate,
Glycerin diacrylate and methacrylate and the following formula ■ 0+OH, OH snow 0←C0-C=CH@ ・
・・■(In the formula, R5 and R6 are H or a methyl group, p is 1
(an integer of 20 to Functional compounds can also be used. When the above-mentioned (meth)acrylic resin is used as a polymer, its weight average molecular weight is 5.
．． OOO~2. A range of OOO,000 is preferred.

The weight ratio of the IJ lux component to the modified rigid polymer component is 85:15 to 99.
5: CL 5, preferably 94:6'1Thl, -
It is preferable that the ratio of the rigid polymer component be in the range of 99:1, and the ratio of the rigid polymer component may be higher than this, but the effect of improving performance will not be large, and on the other hand, the composite material may become too hard. So good! It's not right. Also, the ratio is rl, 5
If the weight ratio is less than that, the reinforcing effect will be insufficient.

To produce a composite material using the modified rigid polymer of the present invention as a reinforcing material, there are two methods: starting from a matrix resin monomer, mixing it with a polymer, and an intermediate method. Starting from a matrix resin monomer or a mixture of a monomer and a polymer, the monomer components are polymerized using a polymerization initiator,
Curing is particularly preferred since it is possible to obtain a composite material with more uniform molecular dispersion. Any known compound can be used as the polymerization initiator, but when curing by heating, it is preferable to use a compound that decomposes during heating. Substances capable of initiating polymerization include, for example, benzoyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, dicumyl peroxide, acetyl peroxide, lauroyl peroxide, azobisin butyronitrile, and the like. In the case of polymerization and curing at room temperature, for example, a combination of peroxide and amines, peroxide and sulfinic acids, or peroxide and cobalt compounds can be used. When using a combination of polymerization initiators, the composition of the present invention is divided into two parts, the peroxide is mixed in one half, and the amines, sulfinic acids, etc. are mixed in the other half. or cobalt compounds.

When performing polymerization curing by irradiation with light such as ultraviolet rays or visible light, a photosensitizer such as benzoin methyl ether,
Preferably, benzoin ethyl ether, benzoin propyl ether, a combination of camphorquinone and amines, etc. are used.

The amount of the polymerization initiator to be used is determined as appropriate, but Q is preferably 01 to 10% by weight based on the entire mixture.

On the other hand, to produce the composite material of the invention, for example in the case of a polymer resin matrix, conventionally known molding techniques such as extrusion molding, injection molding, pressure molding, blow molding, etc. can also be applied.

The composite material of the present invention may further contain inorganic fillers, colorants, polymerization inhibitors, ultraviolet absorbers, oxidation stabilizers, and the like, if necessary.

Next, the present invention will be explained in more detail with reference to Examples. still,
Performance evaluation of the cured composite material was performed by the method shown below.

[Bending strength]

The test piece was a 25 x 4 mm cylinder, and a three-point bending method with a span of 20 planes was used, and the test piece was determined using the following formula.

π x [Test specimen diameter] [Indirect tensile (diametral) strength] The test piece is a cylinder of 6 x 6 flφ, and when compressive force is applied in the diametrical direction, tensile stress is generated in the direction perpendicular to the compressive force. The value is calculated using the following formula using a standard tensile test method.

[Water absorption]

The test piece was a cylinder of 110 x 1φ, and was measured after being stored in water at 57°C for 7 days.

[Acetone swelling degree]

The test piece was 10 x 1-φ and measured after being stored at room temperature for 24 hours.

Example 1 Into a 500 m separable flask, put 350 ml of dimethyl sulfoxide, add sodium hydride [LOD 84 mol] under a nitrogen gas flow, and add 70 to 75 mol of dimethyl sulfoxide while stirring.
After being maintained at ℃ for 40 minutes, it was cooled to room temperature 1.
-] Two elm terephthalamide) [10,042 mol was added and stirred for 4 hours. Next, bromooctane (n-octylbromide) a0042 moles were added, and after stirring for an additional 16 hours, the reaction mixture was poured into a large excess of water.
The precipitated product was separated, thoroughly washed with water, followed by ethanol, and dried at 50-60°C, with a degree of substitution of 5.
0 molar N-octyl-poly(p-phenylene terephthalamide) [hereinafter abbreviated as 0ct(50'1)PPTA] was obtained. Next, dimethyl sulfoxide 150- was placed in the same separable flask as described above, and 10,029 moles of dimethyl sulfoxide was hydrogenated under a stream of nitrogen gas, and the mixture was kept at 70 to 75°C for 40 minutes while stirring. After that, it was cooled to room temperature 1, and the oct(501)PPTAll
Added 29 moles of LQQ and stirred for 4 hours. Next, 0.0029 mol of chloromethylsteref was added, and 1
After stirring for 6 hours, the reaction mixture was poured into a large excess of water, the precipitated product was separated, thoroughly washed with water, then washed with ethanol and dried at 50-60°C to obtain the desired product. Modified poly(p-)22-terephthalamide) C
Hereinafter referred to as Oct-M8-PPT] was obtained. The Oct-Mi9-PPTA is dissolved in chloroform, tetrahydrofuran and methyl methacrylate;
It has been modified to a state where it can be dispersed in molecules and shapes. The infrared absorption spectrum (FT-IR) was measured using the KBr method with 10 integrations using the tetrahydrofuran solution and 2 integrations using a 5 weight superior solution of deuterated chloroform.
Nuclear magnetic resonance absorption spectrum (pT-H-
Qualitative and quantitative analysis was performed by NMR). The results are shown in Figures 1- and 2, respectively. 1650 from Figure 1.
Absorption peaks of double bonds were observed at 18151 cm-' and 1915 cm-', and an absorption peak of the carbonyl group of the ester was observed at 1715 cm-'. Also, from Figure 2, 4.9
A double bond peak was observed at ~a 8 ppm, and the ratio of octyl groups to methylstyrene groups was approximately 1 based on the resonance change of the number of protons of the phenylene group in the main chain and side chain versus the number of protons from the second N position onward. Furthermore, no matter how many N-bonded aqueous systems were estimated, it was far less than 10 parts, confirming that the desired modified product was produced.

Example 2 For methyl methacrylate, Oct-
Ms-PPTAli-i4 and benzoyl peroxide (15
Dissolving heavy-1id and sealing the mixture in a glass tube,
The mixture was heated and polymerized at 60°C for 24 hours, then at 100°C for 24 hours.

The obtained cured product was transparent and had an acetone swelling degree of 1.
43, and it was found that Oct-M8-PPT and polymethyl methacrylate, which is a matrix resin, form a crosslinked structure through chemical bonding.

It has excellent mechanical strength with a bending strength of 2250 9 f 7cm" and an indirect tensile strength of 412 kgfA-, and has a water absorption of 0.52 vq/l-, resulting in significant improvements in physical performance such as improved solvent resistance. was seen.

For comparison, a cured product obtained by polymerizing under similar conditions using only methyl methacrylate without adding Oct-M B-P PTA had a bending strength of 16871.
if/crn", indirect tensile strength 376 kgf/cm"
, water absorption '4 (L 74η/Cm") and acetone swelling degree ψ.

Example 3 Oct-M S -P P T A in Example 2
A cured product was produced in exactly the same manner as in Example 2 except that the amount of was increased to 3% by weight. This one has a bending strength of 2072
kgf/cm', indirect tensile strength of 401! 9f/
Closed 2, water absorption CL52η/ω2 and acetone swelling degree 10
7, and the transparency of the cured product was also good.

Example 4 Oct -M El -P P T divided into Example 2
A cured product was prepared in the same manner as in Example 2 except that the amount of A was increased to 6% by weight. This one has a bending strength of 184
2kgf/c1n”, indirect tensile strength 391k17fA-
1 water absorption 1 (150η/cm” and acetone swelling degree 69%)
and the transparency of the cured product was also good.

(Effects of the Invention) As explained above, according to the present invention, the modified wholly aromatic polyamide-based rigid polymer is characterized in that the amide group in the polymer is converted into N-fil by a specific compound. As a result of the reaction, the 1llIII[! 1" This results in a significant decrease in the cohesive force between molecules, and the strong hydrogen bonds between molecules of conventional aromatic polyamides are inhibited, resulting in self-cohesion when mixed with thermoplastic resins, rubbers, or thermosetting resins. Furthermore, by using the modified rigid polymer, it is possible to significantly improve the compatibility and adhesiveness with various resins, making it possible to improve the compatibility and adhesion of materials with only organic resins. In comparison, the favorable performance of fully aromatic polyamide-based rigid molecules is utilized in composite materials reinforced with the modified polymer, resulting in advantages such as high reinforcement effect, extended service life, and improved fatigue resistance. Due to this effect, for example, various molding materials such as plates, rods, vibrators, artificial marble, various composite resins, adhesives, resin teeth (artificial teeth), resins for denture bases, clothing materials such as resins for inlays, various thermoplastics and thermoplastics. Suitable as curable paint materials, various nameplates, cover materials, general display boards, stickers - various marks, reflective plates, various decorative boards, coating materials such as protective materials, modifiers for various resins, etc.

[Brief explanation of the drawing]

@1 Figure is Oct-MS-P obtained in Example 1.
This is an infrared absorption spectrum (FT-IR) obtained by the PTA (D KBr method), and FIG. 2 is a hydrogen proton nuclear magnetic resonance absorption spectrum ('IPT-a-Nux) measured with a deuterated chloroform solution.

Claims (3)

[Claims] (1) A modified rigid polymer having at least 50% of its total repeating units represented by the following structural formula [1] or [2]. ▲There are mathematical formulas, chemical formulas, tables, etc.▼...[1] ▲There are mathematical formulas, chemical formulas, tables, etc.▼...[2] (In the formula, R_1 and R_2 are hydrogen and an alkyl group having 1 to 20 carbon atoms. and/or an aliphatic group or substituted aromatic group having 2 to 20 carbon atoms having an olefin group having polymerization activity, and at least 5% of the total of R_1 and R_2 is a group having an olefin group having polymerization activity. , R_1
and 20% or less of the total of R_2 is hydrogen) (2) Polyphenylene phthalamide having at least 50% of the total repeating units represented by the following structural formula [3] or [4] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ ... [3] ▲ Mathematical formulas, chemical formulas , tables, etc. ▼...[4] After partially substituting some of the hydrogens in the aramid bond with an alkyl group having 1 to 20 carbon atoms, the unsubstituted aramid group is replaced with an alkali metal or alkyl group in a strong polar solvent. Claim 1, characterized in that it is made into an alkali metal salt with an alkali metal hydride, and then reacted with an aliphatic or substituted aromatic halide compound having 2 to 20 carbon atoms and having an olefin group having polymerization activity. A method for producing the modified rigid polymer described. (3) A composite material in which the modified rigid polymer according to claim 1 is molecularly dispersed in an acrylic or methacrylic resin matrix.