JPH0491164A - Polyamide resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition having excellent mechanical properties, oil resistance, chemical resistance and gas barrierness and remarkably improved tensile properties and moldability by compounding a specific polyamide copolymer with a modified polyester elastomer. CONSTITUTION:The objective composition is produced by compounding (A) a polyamide copolymer derived from a diamine containing >=70mol% of m- xylylenediamine, an alpha,omega-aliphatic dicarboxylic acid and a polyamide-forming component other than the above compounds and (B) a modified polyester elastomer produced by reacting a polyester elastomer with a monomer selected from unsaturated carboxylic acid and unsaturated carboxylic acid derivative. The component A is preferably a copolymer having a melting point of 170-230 deg.C and a relative viscosity of >=2.0.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a polyamide resin composition that has excellent flexibility, chemical resistance, oil resistance, impact resistance, and moldability, and is applicable to automobile parts, various mechanical parts, etc. The object of the present invention is to provide a polyamide resin composition that can be widely used for.

(Prior Art) Polyamide resins have excellent properties such as moldability, oil resistance, chemical resistance, and heat resistance, and are therefore in great demand as engineering plastics. However, its applications are currently limited due to poor properties such as impact resistance and flexibility.

Many attempts have been made to improve impact resistance and flexibility. For example, polyamide resin compositions are known in which a large amount of plasticizer is added to impart flexibility. Special polyamide resins such as nylon 12, copolymers of various nylons, and polyamide elastomers are known as those with improved impact resistance and flexibility, and in addition, polyamide resins such as polyolefins, styrene/olefin copolymers, etc. Compositions in which a polyamide resin modified with a saturated carboxylic acid or the like is blended are also known.

(Problem to be solved by the invention) However, in such a polyamide resin composition,
Various problems have arisen. The polyamide resin composition containing a large amount of plasticizer has the drawback that the plasticizer flows out and the composition loses flexibility when used for a long period of time or at high temperatures. Nylon 12, various nylon copolymers, polyamide elastomers, etc. are more expensive than other engineering pluses, so their use is limited. In systems containing modified polyolefins, modified styrene/olefin copolymers, etc., as the blending amount increases, the excellent properties originally possessed by polyamide resins are lost. That is, moldability deteriorates, and oil resistance, chemical resistance, and heat resistance decrease.

Therefore, the present inventors developed a polyamide resin containing a modified polyester elastomer obtained by reacting a commonly used polyamide resin with a monomer selected from unsaturated carboxylic acids and unsaturated carboxylic acid derivatives and a polyester elastomer. A composition was proposed to solve the above problem.

However, when melt-molding the composition, the thermal decomposition temperature of the modified polyester elastomer is lower than that of polyamide, so it decomposes, resulting in a decrease in mechanical properties such as tensile elongation of the molded product. occured.

(Means for Solving the Problems) In order to solve the above-mentioned drawbacks, the present inventors further devoted themselves to research and examination, and as a result, they finally completed the present invention. That is, the present invention is (A) (a) Diamine containing 70 mol% or more of metaxylylene diamine, (b) α.

ω-aliphatic dicarboxylic acid and (c) a polyamide copolymer obtained from lactams and/or aminocarboxylic acids, and (B) a monomer and polyester elastomer selected from unsaturated carboxylic acids and unsaturated carboxylic acid derivatives This is a polyamide resin composition containing a modified polyester elastomer obtained by reacting with.

The components constituting the polyamide copolymer contained in the composition of the present invention include (a) diamine containing 70 mol% or more of metaxylylene diamine, <b> α, ω
- an aliphatic carboxylic acid and (c) a polyamide-forming component other than the above, specifically containing metaxylylene diamine as component (a) in an amount of at least 70 mol%, and optionally the remainder being tetra Aliphatic diamines such as methylene diamine, pentamethylene diamine, hexamethylene diamine, octamethylene diamine, and nonamethylene diamine; Aromatic diamines such as paraxylylene diamine and paraphenylene diamine; 1,3-4'aminomethylcyclohexane, ■ , 4-bisaminomethylcyclohexane, and other aliphatic diamines, one or more diamines can be appropriately selected and used.

(b) Component α, ω-aliphatic dicarboxylic acids include adipic acid, succinic acid, glutaric acid, pimelic acid, superic acid, azelaic acid, sebacic acid, undecanedioic acid,
One or more types of aliphatic dicarboxylic acids such as dodecanoic acid may be selected as desired.

In addition, as the polyamide forming component (c),
Examples include lactams such as caprolactam, enantlactam, and laurinlactam, α, σ amino acids, aminocarboxylic acids such as aminoundecanoic acid, and nylon salts such as hexamethylenediammonium adipate and cyclohexane bis(methylammonium) adipate.

The method for producing the polyamide copolymer contained in the present invention is not limited, and for example, components (a) to (c) may be simultaneously added and reacted, or component (a) and (
A nylon salt may be prepared in advance with component (b), and then component (c) may be added and reacted.

The melting point of the polyamide copolymer used in the present invention is 170°C
Relative viscosity (JIS K681
0-1970, measured in 98% sulfuric acid) is 1.8 or more, and preferably 2.0 or more, so the components (a) to (c) are adjusted to form the polyamide copolymer. The blending ratio may be selected as appropriate.

Next, examples of the polyester elastomer used to prepare the modified polyester elastomer (B) contained in the composition of the present invention include polyester-polyether block copolymers, polyester-type block copolymers, and the like.

The above polyester-polyether block copolymer is
- It is a block copolymer that has the properties of a rubber-like elastic body because polyester is used as a hard segment and polyether is used as a soft segment, and these segments are arranged alternately and repeatedly.

The acids and alcohols constituting such polyester units are mainly aromatic dicarboxylic acids and alkylene glycols having 2 to 15 carbon atoms, respectively. Specific examples of dicarboxylic acids include terephthalic acid, isophthalic acid, ethylenebis(P-oxybenzoic acid), naphthalene dicarboxylic acid, adipic acid, sebacic acid, 1,4-cyclohexanedicarboxylic acid, p-(β-hydroxyethoxy) Examples include benzoic acid. A specific example of glycol is
Ethylene glycol, propylene glycol, tetramethylene glycol, pentamethylene glycol, 2.2
-Dimethyltrimethylene glycol, hexamethylene glycol, decamethylene glycol, cyclohexane dimetatool, cyclohexane jetanol, benzenedimetatool, benzenedethanol and the like. Suitable dicarboxylic acids and glycols have a melting point of 200° C. or higher when made into a polyester having a molecular weight sufficient to form fibers.

The polyether unit, which is the soft segment of the block copolymer, is a polyoxyalkylene glycol having an average molecular weight of about 500 to 5,000.

The monomer unit of this polyoxyalkylene glycol unit is an oxyalkylene group in which the alkylene group has 2 to 9 carbon atoms. Specifically, preferred examples include poly(oxyethylene) glycol, poly(oxypropylene) glycol, poly(oxypropylene) glycol, poly(oxytetramethylene) glycol, and the like.

The polyether may be a single polyether, a random copolymer, a block copolymer, or a mixture of two or more polyethers. Furthermore, the polyether may have a small amount of aliphatic group, aromatic group, etc. in its molecular chain, or may be a modified polyether containing sulfur, nitrogen, phosphorus, etc.

The polyester-polyether block copolymer contains 1 to 85% by weight of polyether units, preferably 5 to 80% by weight.
1% by weight, and the polyester units are 99-15
It is contained in an amount of 95 to 20% by weight, preferably 95 to 20% by weight.

Examples of polyester-type block copolymers include those obtained by reacting crystalline aromatic polyesters with lactones; examples of crystalline aromatic polyesters include:
Examples include polymers mainly having ester bonds or ester bonds and ether bonds, having at least one aromatic group as a main repeating unit, and having a hydroxyl group at the end of the molecule. The crystalline aromatic polyester preferably has a melting point of 150°C or higher when formed into a polymer with a high degree of polymerization. When the polyamide resin composition of the present invention is used as a molding material,
Polymers with a molecular weight of 5,000 or more are preferred, but when used for adhesives or coatings, polymers with a molecular weight of 5,000 or less may be used. Preferred specific examples of crystalline aromatic polyesters include homopolyesters, polyester ethers, copolymerized polyesters, It can be found in copolymerized polyester ethers, etc. Examples of homopolyesters include:
Examples include polyethylene terephthalate, polytetramethylene terephthalate, poly-1,4-cyclohexylene dimethylene terephthalate, polyethylene-2,6 naphthalate, and the like. Examples of polyester ethers include:
Examples include polyethylene oxyhenzoate, poly-p-phenylene bisoxyethoxy terephthalate, and the like.

The copolymerized polyester or copolymerized polyester ether mainly includes tetramethylene terephthalate units,
Alternatively, examples include polymers having ethylene terephthalate units and further having other copolymer components. Such copolymerization components include tetramethylene terephthalate units,
Ethylene isophthalate unit, tetramethylene adipate unit, ethylene adipate unit, tetramethylene sebacate Ii position, ethylene sebacate unit, ■, 4-cyclohexylene dimethylene terephthalate unit, tetramethylene p-oxybenzoate unit, ethylene-p-
Examples include oxybenzoate units. It is preferable that the copolymerized polyester and the copolymerized polyester ether contain 60 mol% or more of tetramethylene terephthalate units or ethylene terephthalate units.

As the lactone, which is the other component forming the polyester type block copolymer, ε-caprolactone is most preferred, but enantlactone, cabrylolactone, etc. can also be used. Two or more types of these lactones may be used.

The polyester type block copolymer contains the crystalline aromatic polyester and lactones in a weight ratio of 97/3 to 5/9.
It is obtained by copolymerization using a ratio of 95%. Preferably, this weight ratio is 9515 to 30/70. In the above copolymerization, a catalyst is added if necessary, and the reaction is allowed to proceed by heating and mixing. Polyester elastomer (polyester-polyether block copolymer and/or polyester type block copolymer) obtained in this way
may be used alone or in combination of two or more.

The modifier which is reacted with the polyester elastomer to obtain the modified polyester elastomer is selected from unsaturated carboxylic acids and their derivatives. Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, α-ethyl acrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, endobicyclo(2,2,1) hepto -5-ene-2,3-dicarboxylic acid (nadic acid), methyl-endocys-bicyclo(2,2,1) hept-5-ene-
Examples include 23-dicarboxylic acid (methylnadic #). Examples of derivatives of unsaturated carboxylic acids include derivatives of the above acids, such as acid halides, amides, imides, acid anhydrides, and esters. Specific examples include maleyl chloride, maleimide, maleic anhydride, citraconic anhydride, monomethyl maleate, dimethyl maleate, and glycidyl maleate. Among these, unsaturated dicarboxylic acids or unsaturated dicarboxylic acid anhydrides are preferably used, and maleic acid, nadic acid, or acid anhydrides thereof are particularly preferred.

These modifiers are used in an amount ranging from about 0.01 to about 20% by weight, preferably from about 0.02 to about 20% by weight, based on the polyester elastomer. If it is less than 0.01% by weight, the effect of improving the physical properties of the polyamide resin composition is small (,2
If it exceeds 0% by weight, gelation tends to occur during the grafting reaction, which is not preferable.

The method of reacting the modifier with the polyester elastomer (graft copolymerization) is not particularly limited, but it is desirable that the resulting modified polyester elastomer does not contain undesirable components such as gel. It is undesirable that the processability deteriorates if the Specifically, for example, the above-mentioned polyester elastomer, a modifier, and a radical generator are blended and melt-kneaded to cause a graft reaction, and a modified polyester elastomer is obtained. As a radical generator,
Known organic peroxides or diazo compounds may be used.

Specific examples include benzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, cumene hydroperoxide, and azobisisobutyronitrile. The amount of the radical generator used is 0.05% by weight or more, preferably 0.1 to 0.1% by weight based on the polyester elastomer.
It is 1.5% by weight.

In the polyamide resin composition of the present invention, a polyamide copolymer (A) and a modified polyester elastomer (
B) Weight ratio (^) / (B) to 9515 ~ 5/
95, more preferably (A)/(B
) is preferably 90/10 to 10/90. If the weight ratio of the modified polyester elastomer is less than 9515, impact resistance, flexibility, etc. will not be improved.

If the weight ratio of the modified polyester elastomer is greater than 5/95, gas permeability, water resistance, etc. will decrease.

The compositions of the present invention may further contain other additives.

Examples of additives include colorants, stabilizers, inorganic fillers, organic fillers, fibrous reinforcing agents, and other various auxiliaries.Usually, polyamide copolymers (A) and modified polyester elastomers (B) are used. ) is mixed under heat,
The above additives may be added at any of the initial, intermediate, or final stages of mixing. The above mixture is
Conventionally known devices can be used. For example, a mixing device such as a reaction device with stirring blades, a screw or twin-screw extruder, a Banbury mixer, a Nigu, a mixing roll, etc. can be used alone or in combination. The heating and mixing temperature is preferably equal to or higher than the melting points of the polyamide copolymer (A) and the modified polyester elastomer (B).

(Function) The modified polyester elastomer (B) is obtained by subjecting a polyester elastomer to a graft reaction with a modifier selected from unsaturated carboxylic acids and derivatives thereof. It is presumed that by mixing this and the polyamide copolymer resin (A) under heating, the graft-reacted carboxylic acid and its derivatives partially react with the amino end groups of the polyamide resin. It is presumed that this reaction promotes homogeneous and compatible dispersion of the polyamide resin and modified polyester elastomer. In this way, flexibility, impact resistance, etc. can be added while maintaining the excellent properties of polyamide resin.

Furthermore, by using a polyamide copolymer, processing can be performed in a low temperature range, and decomposition of the polyester elastomer can be prevented and moldability and general mechanical properties can be maintained.

(Example) The present invention will be specifically explained using examples.

In this example, a polyamide copolymer with a relative viscosity of 2.
12 (in 98% sulfuric acid; 1 g/100 d25'
A copolymer (hereinafter referred to as CoM) obtained by reacting 90 wt% metaxylylene adipamide with 10 wt% ε-caprolactam (c) was used after vacuum drying at 100°C for 16 hours.

Examples of polyester elastomers include ■Polyether-polyester elastomer of polytetramethylene glycol and polytetramethylene terephthalate (Belprene P150B manufactured by Toyobo Co., Ltd.), and ■Polyester-type block copolymer of polycaprolactone and polytetramethylene terephthalate (Toyobo Co., Ltd.). Perblane S-1000 manufactured by Co., Ltd. was used.

In addition, in Examples and Comparative Examples, tensile properties were measured by the following method.

(ii) A No. 3 dumbbell test piece as described in JIS 46301 was prepared using the obtained sheet molded product. Test pieces were punched out with a dumbbell so that the length direction was perpendicular to the flow direction, and test sheets with pins were punched out with a dumbbell so that the fused bond was in the center.

The test piece was 50m/wi according to JIS-6301 method.
It was stretched perpendicular to the flow direction at a gross head speed of n, and the load at breakage was measured. The initial cross-sectional area (
The value divided by cj) was taken as the tensile strength, and the elongation of the sample at break with respect to the initial sample length was taken as the tensile elongation (%).

Production Example Maleic anhydride-modified polyester elastomers (referred to as ■' and ■', respectively) were synthesized as follows.

100 parts by weight of the above (1) or (2), 0.5 parts by weight of maleic anhydride, and 0.3 parts by weight of Tsukumil peroxide were uniformly mixed in a mixer. This mixture was supplied to a twin-screw extruder, and a maleic anhydride modification reaction was carried out at a cylinder temperature of 200 to 230°C. The reaction products thus obtained were dried in a vacuum dryer at 80°C for 12 hours to obtain modified polyester elastomers 0' and 2'.

Examples 1 to 4 The above copolyamide resin and the modified polyester elastomer ■' or ■' obtained in the above production example were triblended at the ratio shown in Table 1, and then mixed using a 3°■φ twin screw extruder. A beret was manufactured. The cylinder temperature at that time was 235°C. The obtained pellet was heated to 16°C at 70°C.
Vacuum dried for an hour.

Using the pellets obtained above, each test sheet was produced using a sheet extrusion die attached to the tip of a 30 mm diameter twin-screw extruder. Detachable φ1 for sheet extrusion die
By installing a bottle, the flow of resin is divided once,
It is now possible to prepare sheets for testing the melt adhesion of resins.

The cylinder temperature at that time was 235"C, and a sheet molded product with a width of 12c and a thickness of 0.8m was obtained using a take-off device.

Comparative Examples 1 to 4 Test pieces were prepared in the same manner as in Examples using polymethaxylylene adipamide (MXD-6) with a relative viscosity of 2.2 as the polyamide resin and having the compositions shown in Table 1.

Comparative Examples 5-6 The copolyamide resin used in Examples 1-4 was used. However, unmodified polyester elastomers (1) and (2) were used and the compositions shown in Table 1 were used.

The above results are also listed in Table 1.

(Effects of the Invention) As is clear from Table 1, the tensile properties of the test pieces prepared using the copolyamide resin compositions of Examples 1 to 4 were lower than that of the samples with a melt-bonded part provided with a bottle. The tensile properties of the sort made without using a bottle (sort made without using a bottle) are also almost unchanged.

However, it can be seen that in Comparative Examples 1 to 4, the sheets without an adhesive part are equivalent to Examples 1 to 4, but the tensile properties of the sheets with a fused adhesive part are significantly lower in both strength and elongation.

In addition, in Comparative Examples 5 and 6, the compatibility between the copolyamide resin and the polyester elastomer was insufficient, and although pellets could be prepared, sheet molding was not possible due to unstable fluidity, and tensile properties could not be measured. Became.

When tubular molded products were extruded using the compositions of these Examples and Comparative Examples, Examples 1 to 4 were similar to the above results.
The specimens of Comparative Examples 1 to 4 had a slight discoloration, cracks in the spider portion, and a decrease in strength, although beautiful tubular bodies with excellent surface gloss and no discoloration were obtained.

The polyamide resin composition of the present invention has not only excellent mechanical properties, oil resistance, chemical resistance, and gas barrier properties, but also
In particular, it has excellent tensile properties and moldability, making it useful as an engineering plastic.
It can be molded into films and sheets, and can be used in a wide range of applications, from extrusion molded products such as tubes, hoses, and belts to injection molded products such as noise reduction gears, making it a great contribution to industry.

Patent applicant: Toyobo Co., Ltd.

Claims (1)

[Claims] (A) A polyamide copolymer obtained from (a) a diamine containing 70 mol% or more of metaxylylene diamine, (b) an α,ω-aliphatic dicarboxylic acid, and (c) a polyamide-forming component other than the above, and (B) A polyamide resin composition containing a modified polyester elastomer obtained by reacting a monomer selected from unsaturated carboxylic acids and unsaturated carboxylic acid derivatives with a polyester elastomer.