JPH04189533A - Tubular molded product - Google Patents

Abstract

PURPOSE:To mold the above product excellent in weather resistance and heat resistance and appearance free from a change and reduce a weight change ratio and dimensional change ratio, by a method wherein the product is comprised of a copolymer polyamide containing a dimerized fatty acid component as a copolymer component. CONSTITUTION:Polymer fatty acid obtained by polymerizing basic fatty acid or synthetic basic fatty acid from natural oils and fats and possessing at least a double bond or a triple bond, for example, of 8-24C is used. A main component of a copolymer polyamide is a polyamide obtainable by condensation polymerization of diamine with lactam of three or more membering structure, polymerizable omega-amino acid, or dibasic acid. A tubular molded product is that though it is not specially limited when the same is a cylindrical and long tube or hose, concretely a tubular molded product having the inner diameter of 1-50mm and a wall thickness is in 0.1-10mm is preferable. Then the same may be the tube comprised of only one layer of a resin layer containing the copolymer polyamide or a laminated layer tube provided with the next resin layer on its inside or outside.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a tubular molded article made of a specific polyamide resin or resin composition.

Specifically, since the material is sufficiently flexible, there is no need to include large amounts of plasticizer, so there is no appearance defect due to plasticizer bleed-out that occurs during tube use, and plasticizer dissipation in high-temperature environments. This article relates to an excellent tubular molded product that does not undergo significant weight or dimensional changes due to

[Prior Art and Section B] Polyamide resin has excellent resistance to chemicals, oil, gasoline, etc., and is therefore used for various types of tube materials for industrial use, automobile use, and the like. However, the nylon 6, nylon 12, or nylon 11 resins that have conventionally been commonly used for such applications do not necessarily have sufficient flexibility, and for applications that require flexibility, PO is used as a plasticizer.
It was necessary to add 5-30% by weight of a low molecular weight compound such as BO (paraoxybenzoic acid octyl ester). For this reason, when using tube molded products, the plasticizer bleeds out and powdery matter adheres to the surface, resulting in poor appearance, and especially when used in high-temperature environments such as the engine room of a car. There was a disadvantage that the plasticizer impregnated in the tube was dissipated rapidly, resulting in a significant decrease in weight and dimensions, and as a result, the flexibility of the tube was lost. There was a desire to obtain a tubular molded product that was sufficiently flexible and maintained the chemical resistance, oil resistance, and gasoline resistance characteristic of nylon.

[Means for Solving the Problems] In view of the above-mentioned problems, the present inventors have made extensive studies and have found that by using a specific polyamide resin or resin composition, the flexibility of the tube can be increased without adding much plasticizer. The inventors have discovered that it is possible to obtain a tubular molded product that maintains the same temperature, and also largely eliminates appearance defects due to plasticizer bleed-out, weight loss due to plasticizer dispersion in high-temperature environments, and size reduction. Reached.

That is, the gist of the present invention is as follows: (1) A tubular molded article made of a copolyamide containing a dimerized fatty acid component as a copolymerization component;
(a) 35 to 98% by weight of copolyamide containing a duplex fatty acid component as a copolymerization component, (b) α, β
The present invention relates to a tubular molded article comprising a polyamide resin composition comprising 2 to 65% by weight of an olefin polymer copolymerized with or modified with an unsaturated carbonic acid or a derivative thereof.

The present invention will be explained in detail below.

The main component of the copolyamide referred to in the present invention is a polyamide obtained by polycondensation of a lactam having three or more membered rings, a polymerizable ω-amino acid, or a dibasic acid and a diamine. Specifically, the raw materials for these polyamides are:
Lactams such as ε-caprolactam, enantholactam, capryllactam, lauryllactam, α-pyrrolidone, α-piperidone, 6-aminocaproic acid, 7-
Omega-amino acids such as aminohebutanoic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, adipic acid, glutaric acid, pimelic acid, superric acid, azelaic acid, sebacic acid, undecanedioic acid, dodecadionic acid, hexadeca Dionic acid, hexadecenedioic acid, eicosandioic acid, eicosadienedionic acid, diglycolic acid, 2
, 2,4-trimethyladipic acid, xylylene dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, dibasic acids such as isophthalic acid, hexamethylene diamine, tetramethylene diamine, nonamethylene diamine, undecamethylene Diamine, dodecamethylene diamine, 2,2,.4 (or 2°4; 4)'-trimethylhexamethylene diamine, bis-(4,4'-
Examples include diamines such as aminocyclobexyl)methane and metaxylylene diamine.

Specific examples of such polyamides include nylon 4, 6, 7, 8.11, 12, 6.6.6.9.6.
10.6.11.6.12.6T, 6/6.6.6/1
Examples include 2.6/6T.

゛ The dualized fatty acids used in the present invention include unsaturated fatty acids ζ, for example, basic fatty acids from natural fats and oils having 8 to 24 carbon atoms and one or more double bonds or triple bonds, or synthetic monobasic fatty acids. A polymerized fatty acid obtained by polymerizing a fatty acid is used. Specific examples include duplexes of linuric acid and linoleic acid.

Commercially available polymerized fatty acids usually have dimerized fatty acids as the main component and also contain raw fatty acids and trimerized fatty acids, but the dimerized fatty acid content is 70% by weight or more, preferably 95% by weight. It is desirable that the amount is at least 98% by weight, more preferably at least 98% by weight.

The commercially available product is also called dimer acid.

Furthermore, commercially available polymerized fatty acids may be used after being distilled to increase the content of dimerized fatty acids, or, depending on the case, may be hydrogenated to reduce the degree of unsaturation.
~ Diamines used to prepare the polymer with dimerized fatty acids include ethylenediamine, 1,4-diaminobutane, hexamethylenediamine, nonamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2.2; 4 (or aliphatic diamines such as 2.4,414-limethylhexamethylenecyamine, bis-(4,
Examples include diamines such as alicyclic diamines such as 4'-aminocyclohexol methane and aromatic diamines such as metaxylylene diamine.

The content of dimerized fatty acids in the copolymerized amide is from 1 to 80% by weight, preferably from 10 to 50% by weight. If this amount is low, the effect of improving resistance to heat at low temperatures cannot be expected. On the other hand, if it is too high, the melt viscosity will be too low, making it inconvenient for extrusion molding.

The melt viscosity of the copolyamide of the present invention is 2,000 to 15,000 voids, preferably 4,000 to 10,000 voids, as measured at 240°C.

If the melt viscosity is too low, the physical properties of the molded article will be poor. On the other hand, if it is too high, molding becomes difficult, which is not preferable.

In the copolyamide containing a dimerized fatty acid component, the polyamide terminal may be alkylated, and if the polyamide terminal is alkylated, the terminal group of the polyamide may be in addition to the hydrocarbon group introduced by the alkylation. , there are amino groups and/or carboxyl groups derived from the raw materials for the polyamide described above.

Hydrocarbon groups are obtained by hydrolyzing polyamide using hydrochloric acid.
Measured by gas chromatography. Amino groups are determined by dissolving the polyamide in phenol and titrating with 0.05 N base. In addition, carboxyl groups can be obtained by dissolving polyamide in benzyl alcohol. Measured by titration with IN caustic soda.

The total number of terminal groups is the sum of the numbers of the above hydrocarbon groups, amino groups and/or carboxyl groups.

In the present invention, the number of the above-mentioned hydrocarbon groups when terminally alkylated is 25 equivalent % or more, preferably 30 equivalent % or more of the total number of terminal groups. Also, industrially 40~
The content is preferably 95% by weight, more preferably 50 to 90% by weight.

The terminally alkylated copolyamide can be obtained by polycondensing the above-mentioned polyamide raw material in the presence of a monocarboxylic acid having 7 to 23 carbon atoms.

The above monocarboxylic acids having 7 to 23 carbon atoms include enanthic acid, caprylic acid, capric acid, pelargonic acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid,
Aliphatic monocarboxylic acids such as myristoleic acid, valmitic acid, stearic acid, oleic acid, linoleic acid, arachidic acid, hehenic acid, cycloaliphatic monocarboxylic acids such as cyclohexanecarboxylic acid, methylcyclohexanecarboxylic acid, benzoic acid , aromatic monocarboxylic acids such as toluic acid, ethylbenzoic acid, and phenylacetic acid. It is also possible to use corresponding derivatives, such as acid anhydrides, esters, amides, etc., which can play the same role as the above-mentioned acids during the reaction for producing polyamides.

In the present invention, a polyalkylene oxide can be added to the copolymerized polyamide and used as a resin mixture, but the polyalkylene oxide used here is preferably a polyalkylene oxide having an alkylene chain having 2 to 4 carbon atoms. Specific examples thereof include polyethylene oxide, polypropylene oxide, polytetramethylene oxide, and the like. Also, this molecular weight is usually
It is preferably about 300 to 6,000.

As a method for preparing the polyamide resin mixture of the present invention, polyalkylene oxide may be added to the above-mentioned copolymerized polyamide and melt-mixed, but since polyalkylene oxide has poor dispersibility, it is usually carried out at the production stage of the polyamide resin. Preferably, the polyalkylene oxide is added at . In this case, when starting the reaction and polymerizing the polyamide raw material according to a conventional method, the polyalkylene oxide can be added at any stage from the start of the reaction until the start of the reaction under reduced pressure.

The amount of the polyalkylene oxide added is usually 0.1 to 10% by weight, preferably 0.1 to 10% by weight, based on the entire resin mixture.
．． It is 5 to 5% by weight, more preferably 1 to 4% by weight. If the amount added is too small, the effect of improving moldability, especially mold releasability, will not be significant, while if it is too large, gas generation will occur during molding, making it undesirable for melt molding.

The polyalkylene oxide in the resin mixture of the present invention is significant in that it exists in the resin in an unreacted (as is) state, unlike known polyetheramides and polyetheresteramides, and it forms a covalent bond with the polyamide. In the case of reacting with polyester, ie, forming polyether-thylamide or polyetheresteramide, the effect of improving moldability is not significant.

Next, olefin polymers copolymerized with or modified with α,β-unsaturated carboxylic acids or derivatives thereof will be explained.

α, β-unsaturated carboxylic acid or its derivative is 3 to 1
Ethylenically unsaturated mono- or dicarboxylic acids with 2 carbon atoms, and monocarboxylic acids with alcohols of 1 to 29 carbon atoms, diesters of dicarboxylic acids and monoesters of dicarboxylic acids, and 0 to 100% of carboxylic acid groups
are metal salts of monocarboxylic acids, dicarboxylic acids, and monoesters of dicarboxylic acids that have been ionized by neutralization with metal ions.

Specifically, metals such as methyl methacrylate, butyl acrylate, ethyl acrylate, alkyl esters of acrylic acid and methacrylic acid, sodium methacrylate, zinc methacrylate, maleic acid, maleic anhydride, maleic acid monoethyl ester, and maleic acid monoethyl ester. salts, fumaric acid, fumaric acid monoethyl ester, metal salts of fumaric acid monoethyl ester, maleic acid, alkyl monoesters of fumaric acid having up to 29 carbon electrons, glycidyl methacrylate, glycidyl acrylate, and the like. These α, β-unsaturated carboxylic acids or derivatives thereof may be randomly copolymerized with monomers such as ethylene, propylene, butene, or may be graft polymerized or graft-reacted with olefin polymers such as ethylene, propylene, butene. You can leave it there.

Therefore, examples of olefin polymers useful in the present invention include the following random copolymers and graft products. Namely, ethylene/methacrylic acid or zinc salt of methacrylic acid: ethylene/isobutyl acrylate/zinc salt of methacrylic acid: ethylene/methyl acrylate/monoethyl ester of maleic anhydride and 0 to 100 thereof.
% Neutralized Zinc, Sodium, Calsulam, Lithium, Antimony, and Potassium Salts: Ethylene/Propylene/g-R Hydromaleic Acid: Ethylene/Butene/g-Maleic Anhydride: Ethylene/Methyl Acrylate/Methacrylic Acid and its Zinc Salts : Ethylene/vinyl acetate/methacrylic acid and its zinc salt: ethylene/propylene/1.4-
Hexadiene/g-maleic anhydride: ethylene/propylene/norbornadiene/g-maleic anhydride: ethylene/propylene/tetrahydroindene/g-fumaric acid: ethylene/glycidyl methacrylate: ethylene/
Vinyl acetate/glycidyl methacrylate: Ethylene/propylene/g-tetrahydrofurfuryl methacrylate: Ethylene/buty2propy1fufug-maleic anhydride/g-tetrahydrofurfuryl methacrylate: Ethylene/butene/g-4! l maleic acid/g-tetrahydrofurfuryl methacrylate (g means graft)
etc.

If the α,β-unsaturated carboxylic acid or its derivative is randomly copolymerized, the amount of α,β-unsaturated carboxylic acid or its derivative is 50
The amount may be less than 0.01 to 2% by weight in the case of grafting.

In the present invention, when adding an olefin polymer copolymerized with such α,β-unsaturated carboxylic acid or its derivative or modified with these, a resin of this and the above copolyamide or copolyamide and polyalkylene oxide is used. The blending ratio with the mixture (hereinafter sometimes simply referred to as copolyamide) is 35 to 35%.
Preference is given to 2 to 65% by weight of the olefin polymer relative to 98% by weight. Addition of the olefin polymer has the effect of improving the toughness of the molded product, but if the amount exceeds 65% by weight, the heat resistance of the tube molded product will deteriorate. More preferably, it is 2 to 60% by weight.

In addition, the copolyamide and polyamide resin composition constituting the tubular molded product of the present invention may optionally contain reinforcing agents such as glass fiber and carbon fiber, clay, silica, alumina, silica alumina, silica magnesia, Known additives such as fillers such as glass peas, asbestos, graphite, gypsum, etc., dyes and pigments, flame retardants, antistatic copper compounds, antioxidants, etc. can also be included.

The tubular molded product of the present invention is not particularly limited as long as it is a long, cylindrical tube or hose, but specifically, it has an inner diameter of 1 to 50 points and a wall thickness of 0.1 to 1
A 0 mm tubular molded product is preferred. Further, it may be a tube consisting only of resin layers containing the copolymerized polyamide of the present invention, or it may be a laminated tube with the following resin layer provided inside and/or outside. Examples of other resin layers include thermoplastic resins such as polyolefin and ethylene-vinyl acetate copolymer.

There are no particular restrictions on the method of molding the tubular molded product, and it can be molded using an ordinary extruder.

(Examples) Hereinafter, the present invention will be specifically explained using Examples, but the present invention is not limited thereto.

In addition, % in the following examples indicates weight % unless otherwise specified.

<Production of copolyamide> (Copolyamide 1, 2) 2001 Into an autoclave, dimerized fatty acids (dimer: 96%, monomer: 1%, trimer) were added in the amounts shown in Table 1 below. =
3%, manufactured by Henkel, trade name Enpol '1010) Hexamethylene diamine and a salt of dimerized fatty acid and diamine in an amount of water to make a 75 wt% aqueous solution, and after replacing with N2, the solution shown in Table 1 was prepared. The reaction was carried out for 1 hour at temperature and internal pressure.

ε-caprolactam and polyalkylene oxide heated to 250°C in the amounts shown in Table 1 were added to this mixture, and the internal temperature was 250°C.
After reacting for 1 hour at 70° C. and an internal pressure of 8 kg, the pressure was reduced to the pressure shown in Table 1 and polycondensation reaction was carried out for 1 hour.

After restoring the pressure to normal pressure by introducing nitrogen, it was extracted into strands and turned into berent, unreacted monomers were extracted and removed using boiling water, and the mixture was dried.

The physical properties of the copolyamide' thus obtained are shown in Table 1 below.

(Copolymerized Polyamide 3.4) A polycondensation reaction was carried out in the same manner as in Production Examples 1 and 2 except that polyalkylene oxide was not added.

The results are shown in Table 1.

The polyalkylene oxides in Table 1 are as follows.

SANNIX PP-300'O: Polypropylene glycol manufactured by Sanyo Chemical ■ (molecular weight 3000) 2 SANNIX PP-1000: Same as above (molecular weight 10
00) The physical properties of the copolyamides listed in Table 1 were measured according to the following method.

(1) Tensile test: Based on ASTM D638 (
2) Bending test: Based on ASTM D790 (
3) Izod impact test: Based on ASTM D256 (4) Using a melt viscosity flow tester (Shimadzu CFT 500A), at a shear rate of 100 (sec-') at 240°C.
I read μa at that point.

<Production method of polyamide resin composition> Copolyamides 1 to 4 and the olefin polymers shown in Table 2 were blended in the proportions shown in Table 2, and a vented twin-screw extruder with a cylinder diameter of 30 mm was used. using a resin temperature of 240~
Pellets were obtained by melt-mixing at 260°C.

Examples 1 to 6 Die diameter: outer diameter 16 φ/inner diameter 11 φ, sizing die diameter 8.5 mm, take-up speed 2.2 m/akin,
A tube with an outer diameter of 8 mm, an inner diameter of 6 m, and a length of 12 C1 was molded using a 45 mm tube extruder at a resin temperature of 250°C. The weather resistance of the obtained tube was tested by exposing it to a sunshine weather oven for 400 hours under the following conditions: black panel temperature 63°C, tank internal temperature 44°C, irradiation/rainfall time = 60/l 2 (min/m1n). , observed changes in appearance.

In addition, as for the heat resistance of the tube, the weight loss rate and the dimensional change rate of the tube length were measured with respect to the initial value before the test when the tube was stored in a hot air oven at 120° C. for 500 hours.

Comparative Examples 1 to 4 Under the same conditions as Examples 1 to 6, polyamide 11 resin or polyamide 12 resin having the flexural modulus shown in Table 2 was molded into a tube, and similar tests were conducted. Ta.

/ (Effects of the invention) As described above, the tubular molded product obtained by the present invention has excellent weather resistance and heat resistance, no change in surface appearance,
Moreover, since the weight change rate and dimensional change rate are small, its commercial value is high, especially when used in harsh environments such as automobile parts.

Claims (3)

[Claims] (1) A tubular molded product made of a copolyamide containing a duplexed fatty acid component as a copolymerization component. (2) (a) 35 to 98% by weight of copolyamide containing a duplexed fatty acid component as a copolymerization component and (b) olefin polymer copolymerized with α,β-unsaturated carboxylic acid or its derivative or modified with these. Combine 2-6
5% by weight of a polyamide resin composition. (3) The copolyamide containing a dimerized fatty acid component as a copolymerization component is a polyalkylene oxide of 0.1 to 10%
The tubular molded article according to claim 1 or 2, which is a resin mixture containing % by weight.