JPH0129380B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a resin composition with excellent impact resistance, flexibility, heat resistance, moldability, etc. In recent years, molding materials made of mixtures of polyamide and various polyolefins have been developed in order to improve the impact strength of polyamide resins when dry or at low temperatures, and to obtain materials that can withstand harsh usage conditions. However, in general, polyamides and polyolefins have poor compatibility because their polarity and reactivity are significantly different. Simply kneading the two in an extruder or the like can produce a finely dispersed structure, resulting in a material with high practical value. That is difficult. To overcome this problem and obtain a composition in which polyamide and polyolefin are intimately mixed with each other, a method that has been commonly used is to provide a copolymerized polyolefin (hereinafter simply referred to as polyolefin) with reactive points with polyamide. In this method, a carboxylic acid derivative is introduced for the purpose of achieving this, and this modified polyolefin and polyamide are blended. (For example, Special Publication No. 42-12546, Special Publication No. 12546,
54-4743, JP 55-44108, JP 56-22468, JP 57-22347, JP 55-9661, JP 55-9662, JP According to the methods shown in these prior examples, in order to utilize reactive polyolefins, the mixture of polyamide and the modified polyolefin is finely dispersed. Although the objective of improving the impact strength of polyamide is achieved by exhibiting a structure, the accompanying reaction may lead to a decrease in fluidity, especially in injection molding, and local thickening may deteriorate the surface appearance of the molded product. It was found that it has the disadvantage of causing deterioration. In other words, modified polyolefins that do not substantially react with polyamide and have the effect of increasing compatibility with polyamide are more effective than modified polyolefins that have functional groups that can react with terminal amino groups or amide groups in the main chain of polyamide. It was discovered that a modified polyolefin with a functional group introduced therein was truly ideal. Therefore, the present inventors have achieved the above-mentioned objectives all at once, and have conducted intensive studies on a resin composition made of polyamide and modified polyolefin that has excellent impact resistance, flexibility, heat resistance, moldability, etc. As a result, it was discovered that a modified polyolefin into which a specific functional group has been introduced is extremely effective, and a composition having a uniform finely dispersed structure can be obtained over a wide composition range, and the present invention has been achieved. That is, the present invention provides (A) 60 to 98% by weight of a polyamide resin and (B) 40 to 2% by weight of a modified copolymerized polyolefin containing 0.001 to 10 mol% of at least one type of functional group represented by the following formulas () to (). %. (In the formula, R ₁ to _{R 5} are hydrogen atoms or carbon atoms 1 to 30
represents an aliphatic, alicyclic or aromatic hydrocarbon residue. ) Modified polyolefins containing functional groups represented by the above formulas () to () in the side chain or main chain can extremely specifically exhibit the effect of increasing compatibility without substantially reacting with polyamide. can. The reason for this is that the above-mentioned functional groups have imide groups, amide groups, etc. and are similar in structure to the units constituting polyamide, so that the modified polyolefin of the present invention has extremely high compatibility with polyamide. As a result, a resin composition that is uniformly excellent in impact resistance, flexibility, heat resistance, fluidity, etc. can be obtained. The polyamide resin (A) used in the present invention refers to any polymer having an amide bond composed of an amino acid, a lactam, or a diamine and a dicarboxylic acid. Examples of the constituent components include 6-aminocaproic acid, 11-amino Amino acids such as undecanoic acid, 12-aminododecanoic acid, para-aminomethylbenzoic acid, lactams such as ε-caprolactam and ω-laurolactam, tetramethylene diamine, hexamethylene diamine, undecamethylene diamine, dodecamethylene diamine, 2,2 ,4-/
2,4,4-trimethylhexamethylenediamine, 5-methylnonamethylenediamine, 2,4-
Dimethyloctamethylenediamine, metaxylylenediamine, paraxylylenediamine, 1,3-
Bis(aminomethyl)cyclohexane, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, 3(4),8(9)-bis(aminomethyl)tricyclo[5,2,1,0 ^2.6 ] Decane, bis(4-aminocyclohexyl)methane, bis(3-methyl-4-aminocyclohexyl)methane, 2,2-bis(4-aminocyclohexyl)
propane, bis(aminopropyl)piperazine,
Diamines such as aminoethylpiperazine, α,ω-diaminopolyoxyethylene, α,ω-diaminopolyoxypropylene, adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanoic acid,
Select from dicarboxylic acids such as terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodium sulfoisophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, diglycolic acid, etc. can do. Polyamide resins particularly useful in the present invention include polycaproamide (nylon 6), polyhexamethylene adipamide (nylon 6), and polyhexamethylene adipamide (nylon 6).
66), polyhexamethylene sebamide (nylon
610), polyhexamethylene dodecamide (nylon
612), polyundecamethylene adipamide (nylon 116), polyundecaneamide (nylon 11),
Polydodecanamide (nylon 12), polytrimethylhexamethylene terephthalamide (nylon
TMDT), polyhexamethylene isophthalamide (nylon 6I), polybis(4-aminocyclohexyl)methandodecamide (nylon PACM12),
Polymethaxylylene adipamide (nylon
MXD6), polyundecamethylene terephthalamide (nylon 11T), polyundecamethylene hexahydroterephthalamide (nylon 11T(H)), and copolyamides and mixed polyamides of these. The polyamide used here is usually produced by melt polymerization, and there are no particular restrictions on the degree of polymerization.
Any polyamide having a relative viscosity within the range of 2.0 to 5.0 can be selected. The modified polyolefin (B) used in the present invention is a polyolefin having at least one functional group represented by the following formulas () to () in its side chain or main chain. Here, R ₁ to _{R 5} are hydrogen atoms or carbon atoms 1 to 30
represents an aliphatic, cyclic or aromatic hydrocarbon acid group. The above functional groups can be created by adding ammonia, primary or secondary aliphatic amines, alicyclic amines or aromatic amines to carboxylic acid groups, acid anhydride groups or epoxy groups. The method for introducing the above functional group into the side chain or main chain of polyolefin is to add ammonia or amines to an α,β-unsaturated carboxylic acid, its acid anhydride, or an epoxy group-containing ethylenically unsaturated compound. It is possible to prepare a -substituted imide, N-substituted amide or N-substituted hydroxyethyl compound and copolymerize it with an olefin monomer, or graft it onto a polyolefin using a radical initiator. The modified polyolefin of the present invention can also be obtained by preparing a polyolefin having a carboxylic acid group, an acid anhydride group, or an epoxy group in advance and adding ammonia or amines thereto.
where α,β-unsaturated carboxylic acid, its anhydride,
Examples of unsaturated compounds containing epoxy groups include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, methylmaleic acid, methylfumaric acid, mesaconic acid, citraconic acid, glutaconic acid, and hydrogen maleate. Methyl, ethyl hydrogen maleate, methyl hydrogen fumarate, methyl hydrogen itaconate, maleic anhydride, itaconic anhydride, citraconic anhydride, endobicyclo-[2,
2,1]-5-heptene-2,3-dicarboxylic anhydride, glycidyl acrylate, glycidyl methacrylate, vinyl glycidyl ether, allyl glycidyl ether, and the like. Examples of amine compounds that form functional groups represented by formulas () to () above by being added to the carboxylic acid group, acid anhydride group, and epoxy group of these monomers include ammonia, methylamine, ethylamine, Butylamine, hexylamine, dodecylamine, oleylamine, stearylamine, cyclohexylamine, benzylamine, aniline, naphthylamine, dimethylamine, diethylamine, methylethylamine, dibutylamine, distearylamine, dicyclohexylamine, ethylcyclohexylamine, methylaniline, phenyl Such as naphthylamine. In other words, the above formula () ~ ()
R ₁ to _{R 5} are preferably a hydrogen atom or an aliphatic, alicyclic, or aromatic hydrocarbon residue having 1 to 30 carbon atoms. Other components constituting the modified polyolefin of the present invention are ethylene, propylene, 1-butene, 1
-Pentene, 4-methylpentene-1,1-hexene, 1,4-hexadiene, dicyclopentadiene, 2,5-norbornadiene, 5-ethyl-
2,5-norbornadiene, 5-ethylidenenorbornene, 5-(1'-propenyl)-2-norbornene, isobutylene, butadiene, isoprene,
Examples include vinyl acetate, styrene, vinyl chloride, ethyl acrylate, isobutyl acrylate, methyl methacrylate, zinc methacrylate, acrylamide, and two or more of these components are selected. In particular, modified polyolefins useful in the present invention include ethylene/propylene copolymers, ethylene/butene-1 copolymers, ethylene/propylene/ 1,4-hexadiene copolymer, ethylene/propylene/5-ethylidene norbornene copolymer, ethylene/propylene/5-
These include ethyl-2,5-norbornadiene copolymer and ethylene/propylene/dicyclopentadiene copolymer. The amount of the functional groups represented by formulas () to () contained in the modified polyolefin of the present invention is in the range of 0.001 to 10 mol%, preferably 0.01 to 5 mol%, based on the number of moles of all the constituent components. If the amount of functional groups is less than 0.001 mol %, the effect of improving compatibility with the polyamide resin will be insufficient and a composition exhibiting an intimately mixed state will not be obtained, which is not preferable. On the other hand, if the amount of functional groups exceeds 10 mol%, the stability of the polyolefin decreases and side reactions such as gelation tend to occur, which is not preferable. There is no particular restriction on the degree of polymerization of the modified polyolefin, and one having a melt index of usually 0.05 to 50 g/10 minutes can be arbitrarily selected. In addition, it is also possible to mix a small amount of ordinary polyolefin which does not contain the functional groups represented by the above formulas () to () with the modified polyolefin of the present invention. In the present invention, it is not necessary for the modified polyolefin to have a functional group capable of reacting with the terminal amino group of the polyamide or the amide group in the main chain. This is because the modified polyolefin used in the present invention is sufficiently compatible with polyamide even if it does not have such a group. However, the composition of the present invention may contain a functional group capable of reacting with a small amount of amide group or amino group as long as the impact resistance, flexibility, heat resistance, fluidity, etc. of the composition of the present invention are not impaired. do not have. The resin composition of the present invention is composed of a mixture of polyamide resins of 60 to 98% by weight, 65 to 95% by weight, 40 to 2% by weight, and 35 to 5% by weight. The blending composition of the polyamide resin and modified polyolefin can be selected within the above range depending on the purpose and use. Generally, when a polyamide resin is the main component, a resin composition with improved impact resistance, flexibility, bending fatigue resistance, etc. can be obtained while maintaining the characteristics of polyamide. In particular, compared to the prior art, the resin composition of the present invention has good fluidity during molding, and molded products with excellent surface appearance can be produced. The method of mixing the polyamide resin and modified polyolefin is not particularly limited, and any commonly known method can be employed. That is, polyamide resin,
The most common method is to uniformly mix modified polyolefin pellets, powder, pieces, etc. using a high-speed stirrer, and then melt-knead them using a single-screw or multi-screw extruder with sufficient kneading capacity. In addition, since the polyamide resin and modified polyolefin of the present invention have extremely good compatibility with each other, there is a method of dry blending the polyamide resin and modified polyolefin during molding without kneading using an extruder, and then molding by injection or extrusion. can also be taken. Furthermore, the functional groups represented by the formulas () to () defined in the present invention can also be formed during melt-kneading of the polyamide resin and polyolefin.
That is, as mentioned above, the reaction between the α,β-unsaturated carboxylic acid or its anhydride introduced into the side chain or main chain of the polyolefin and amines proceeds easily, so that the reaction between the polyamide resin and the α,β-
When melt-kneading a polyolefin containing an unsaturated carboxylic acid or its acid anhydride, adding an amine or the like preferentially increases α, β- in the polyolefin.
An amine is added to an unsaturated carboxylic acid or its acid anhydride to produce a modified polyolefin having a functional group represented by the formulas () to () above, and at the same time, a composition of the modified polyolefin and a polyamide resin can be obtained. found. The resin composition of the present invention may contain other components, such as pigments, dyes, reinforcing materials, fillers, heat resistant agents, antioxidants, weathering agents, lubricants, crystal nucleating agents, as long as they do not impair its moldability and physical properties. Antiblocking agents, plasticizers, antistatic agents, other polymers, etc. can be added. The addition of reinforcing materials and fillers is particularly important, and fibrous or powdered reinforcing materials such as glass fiber, asbestos fiber, carbon fiber, wollastenite, talc, calcium carbonate, and potassium titanate whiskers are added to the mixture of polyamide resin and modified polyolefin. By adding and blending, a composition with high rigidity and high impact strength can be obtained. The composition of the present invention can be used for general injection molded products, hoses,
It is useful for various applications such as tubes, films, monofilaments, wire coatings, hollow molded products, and laminates. The present invention will be explained in more detail with reference to Examples below. The characteristics of the test pieces described in Examples and Comparative Examples were measured and evaluated in accordance with the following method. (1) Relative viscosity: JIS K6810 (2) Melt index: JIS K7210 (3) Fluidity: Evaluated by lower limit injection molding pressure. This means the minimum filling pressure into the mold, and the smaller the value, the better the fluidity. (4) Tensile properties: ASTM D638 (5) Bending properties: ASTM D790 (6) Izot impact strength: ASTM D256 (7) Heat distortion temperature: ASTM D648 (8) Surface appearance of molded product: Visual observation example A (modified Production of polyolefin (A)) 0.1 part by weight of di-t-butyl peroxide and maleic anhydride dissolved in a small amount of acetone to 100 parts by weight of an ethylene/propylene copolymer consisting of 80 mol% ethylene and 20 mol% propylene.
After adding 1.0 parts by weight, the mixture was kneaded at 200°C using an extruder with a diameter of 40 mm to form pellets. After pulverizing the pellets, unreacted maleic anhydride was extracted with acetone, and the graft-reacted maleic anhydride was quantified using an infrared absorption spectrum of the press film, and it was found that it contained 0.52% by weight of maleic anhydride. I found out. This ethylene/propylene-g-maleic anhydride copolymer ("g" represents grafting) is then
Add 2 parts by weight of cyclohexylamine to 100 parts by weight, and mix in a Banbury mixer set at 190°C for 5 minutes.
After kneading for a minute, it was ground. After immersing the crushed pieces in ethanol and extracting unreacted cyclohexylamine, the infrared absorption spectrum of the pressed film was measured, and it was found that 1820cm based on acid anhydride.
The absorptions at ^-1 and 1760 cm ^-1 completely disappeared, and a new characteristic absorption at 1710 cm ^-1 due to the 5-membered ring imide appeared. A propylene copolymer (melt index: 0.6 g/10 minutes) was obtained. Examples 1 and 2 Nylon 6 with a relative viscosity of 2.70 was obtained by melt polymerizing ε-caprolactam at 260°C. The nylon 6 obtained here and the modified polyolefin prepared by the method of Example A were mixed in the ratio shown in Table 1, and then melt-kneaded at 270°C using an extruder with a diameter of 65 mm to form pellets. After drying this beret in vacuum, it was molded into test pieces for measuring various physical properties according to ASTM standards using an injection molding machine at a cylinder temperature of 250°C and a mold temperature of 80°C.
The fluidity was evaluated from the lower limit molding pressure at that time and was found to be extremely good. In addition, the evaluation results of the bone-dry physical properties of the test pieces obtained here are as shown in Table 1, indicating that the material is of high practical value with excellent impact resistance, flexibility, heat resistance, etc. found. Comparative Example 1 The Izo impact strength (23°C) of the nylon 6 used in Examples 1 to 4 was 5.5 kg cm/cm notch,
Impact resistance was unsatisfactory. Comparative Example 2 Ethylene/propylene-g-maleic anhydride copolymer prepared in the first step of Example A: 40% by weight
After mixing nylon 6:60% by weight used in Example 2, kneading and injection molding were carried out in exactly the same manner as in Example 2. Injection molding lower limit pressure is 510Kg/cm ²
It was found that the liquidity was poor. Example B (Production of modified polyolefin (B)) Maleic anhydride and cyclohexylamine were mixed with N,
The following compound was synthesized by reacting in N-dimethylformamide at 30°C to give maleamic acid, and then ring-closing at 60°C in the presence of acetic anhydride and pyridine. 0.1 part by weight of α,α'-bis-t-butylperoxy-p-diisopropylbenzene dissolved in a small amount of acetone and the above maleimide derivative dissolved in a small amount of acetone to 100 parts by weight of a copolymer consisting of 80 mol% ethylene and 20 mol% propylene. After adding 1.0 parts by weight,
The mixture was kneaded and pelletized at 220°C using an extruder with a diameter of 40 mm. After pulverizing this pellet, the terminal reaction compound was extracted with acetone, and the infrared absorption spectrum of the pressed film was measured.
It was found that an ethylene/propylene copolymer was obtained which was exactly the same as the modified polyolefin obtained in Example 1 and which had a functional group represented by the following formula in its side chain. Examples 3 and 4 Substantially equimolar salt aqueous solutions of hexamethylene diamine and adipic acid were charged into a polymerization can and melt polymerized at 280°C to obtain nylon 66 with a relative viscosity of 2.90.
After mixing the nylon 66 obtained here and the modified polyolefin prepared by the method of Example B in the ratio shown in Table 2, using an extruder with a diameter of 65 mm
The mixture was melt-mixed at 290°C and pelletized. After vacuum drying the pellets, test pieces were molded using an injection molding machine at a cylinder temperature of 275°C and a mold temperature of 80°C to evaluate fluidity, and the physical properties of the obtained test pieces when completely dry. was measured and the results shown in Table 2 were obtained. Example 5 Cyclohexyl was added to 100 parts by weight of a mixture of 75% by weight of nylon 6 used in Example 1 and 25% by weight of the ethylene/propylene-g-maleic anhydride copolymer prepared in the first step of Example A. Amine 2
After adding parts by weight, the mixture was melt-kneaded in an extruder set at 270°C to form pellets. The pellets obtained here were immersed in meta-cresol to sufficiently extract and remove the nylon, and the infrared absorption spectrum of the insoluble part of the pressed film was measured. It was found that an ethylene/propylene copolymer having exactly the same absorption spectrum and having a functional group represented by the following formula in its side chain was produced. Further, the kneaded pellets made of nylon 6 and modified polyolefin were injection molded in the same manner as in Example 1, and the fluidity was evaluated and the physical properties of the obtained molded pieces were measured, and the following results were obtained. Injection molding lower limit pressure 390Kg/cm ² Tensile yield stress 520Kg/cm ² Tensile elongation at break >200% Bending stress 710Kg/cm ² Flexural modulus 17500Kg/cm ² Izot impact strength 23℃ No breakage 0℃ 70Kg・cm/cm Notch -20℃ 35 〃 Heat distortion temperature 158℃ Molded product surface appearance Good Example C (Production of modified polyolefin (C)) Ethylene 70 mol%, propylene 15 mol%, 1,
After adding 3.4 parts by weight of N-methylbenzylamine to 100 parts by weight of a copolymer consisting of 14 mol% of 4-hexadiene and 1 mol% of acrylic acid, the mixture was heated at 180°C.
The mixture was kneaded for 10 minutes in a rubber roll mill set at After immersing this strip in ethanol and extracting unreacted N-methylbenzylamine, we measured the infrared absorption spectrum of the press film, and found that the absorption at 1710 cm ^-1 due to the carboxyl group of acrylic acid completely disappeared. However, a new characteristic absorption of 1670 cm ^-1 due to acid amide has appeared,
Ethylene/propylene/1,4-hexadiene copolymer having 1 mol% of functional groups represented by the following formula in the main chain (melt index: 1.6 g/10 minutes)
was gotten. Examples 6 and 7 ε-caprolactam and hexamethylenediamine adipate were mixed in the composition shown in Table 3, charged into a polymerization can, and melt-polymerized at 260°C to produce a nylon 6/66 copolymer. The nylon 6/66 copolymer obtained here and the modified polyolefin prepared by the method of Example C were mixed in the ratio shown in Table 3, and then kneaded using an extruder at 280°C and pelletized. After vacuum drying the pellets, test pieces were molded using an injection molding machine at a cylinder temperature of 260°C and a mold temperature of 60°C to evaluate fluidity. The physical properties were measured and the results shown in Table 3 were obtained. Example D (Production of modified polyolefin (D)) 4.8 parts by weight of N-methylbenzylamine was added to 100 parts by weight of a copolymer consisting of 90 mol% ethylene, 8 mol% vinyl acetate, and 2 mol% glycidyl methacrylate. After that, the mixture was kneaded at 180°C using an extruder with a diameter of 40 mm to form pellets. After immersing this pellet in ethanol and extracting unreacted N-methylbenzylamine, the infrared absorption spectrum of the press film was measured, and the absorption at 1140 cm ^-1 due to glycidyl methacrylate completely disappeared. New characteristic absorption of hydroxyl group is 3300cm
Ethylene/vinyl acetate copolymer that appears in ^-1 and has 2 mol% of the functional group represented by the following formula in the main chain (melt index: 5.0 g/10 minutes)
was gotten. Examples 8 and 9 Nylon 6 and the modified polyolefin prepared by the method of Example D were mixed in the ratios shown in Table 4, and then melt-kneaded using an extruder and pelletized. After vacuum drying the pellets, a test piece was molded using an injection molding machine to evaluate fluidity, and the physical properties of the test piece obtained here were measured when completely dry.
The results shown in the table were obtained. Examples 10 to 22 The same operations as in Examples 1 to 9 were carried out by changing the type of polyamide, the type of modified polyolefin, the blending amount, etc., and the fluidity and physical properties of the obtained test pieces were measured, and the results are shown in Table 5. The results shown are obtained. It was found that in all cases shown in Table 5, materials exhibiting excellent impact strength, flexibility, and heat resistance were obtained.

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[Table] (a) Polyamide resin 610: Polyhexamethylene sebamide, 11:
Polyundecaneamide, 12: Polydodecanamide, 46: Polytetramethylene adipamide,
116: Polyundecamethylene adipamide, 6/
12: Poly(caproamide/dodecaneamide) copolymer (copolymerization ratio: 80/20% by weight), 666:
Polycaproamide polyhexamethylene adipamide mixture (mixing ratio: 5050% by weight),
MXD6: Polymethaxylylene adipamide,
6/6T: Poly(caproamide/hexamethylene terephthalamide) copolymer (copolymerization ratio:
40/60% by weight), PACM12: polybis(4-aminocyclohexyl)methandodecamide,
11T: Polyundecamethylene terephthalamide, 11T(H): Polyundecamethylene hexahydroterephthalamide, TMDT: Polytrimethylhexamethylene terephthalamide, 6I/
PACMI: Poly(hexamethylene isophthalamide/bis(4-aminocyclohexyl)methane isophthalamide) copolymer (copolymerization ratio:
(70/30% by weight) (b) Modified polyolefin [A]: Prepared by the method of Example A. [C]: Prepared by the method of Example C. [E]: Ethylene/butene-1:85/15 (mol%) copolymer having 0.4 mol% of the following functional groups in side chains. (Prepared in the same manner as Example A.) [F]: Ethylene/propylene/dicyclopentadiene having 0.3 mol% of the following functional groups in the side chain:
70/20/10 (mol%) copolymer. (Prepared in the same manner as Example A.) [J]: Polymethylpentene (prepared in the same manner as Example A) having 0.1 mol% of the following functional groups in the side chains and ethylene/methacrylic acid/
Zinc methacrylate: 90/3/7 (wt%)
Mixture of copolymers (mixing ratio: equal weight). [K]: Ethylene/propylene: 90/10 (mol%) copolymer having 1.3 mol% of the following functional groups in the main chain. (Prepared in the same manner as Example C.) [L]: Ethylene/propylene/5-ethylidenenorbornene: 80/13/7 (mol%) copolymer having 0.5 mol% of the following functional groups in side chains. (Prepared in the same manner as Example A.) [M]: Ethylene/propylene: 80/20 (mol%) copolymer having 0.4 mol% of the following functional groups in side chains. (Prepared in the same manner as Example A.

Claims (1)

[Scope of Claims] 1 Modified copolymerized polyolefin 40 to 40 containing (A) 60 to 98% by weight of a polyamide resin and (B) 0.001 to 10 mol% of at least one type of functional group represented by the following formulas () to () A resin composition consisting of 2% by weight. (In the formula, R ₁ to _{R 5} are hydrogen atoms or carbon atoms 1 to 30
represents an aliphatic, alicyclic or aromatic hydrocarbon residue. )