JPS6351454A - Polyamide composition - Google Patents

Abstract

PURPOSE:To obtain a polyamide composition giving a molded article having excellent tensile elongation without lowering the tensile strength, thermal stability and impact strength of base resin, by compounding a polyamide resin with a specific polyester ether block copolymer. CONSTITUTION:The objective composition contains (A) 100pts.wt. of a polyamide resin and (B) 2-35pts.wt. of a polyester ether block copolymer composed of (i) 45-90wt.% segment consisting of terephthalic acid and 2-4C glycol as main constituent components and (ii) 10-55wt.% polyalkylene glycol segment of formula I or formula II, preferably formula II (R is 2-4C hydrocarbon group; lis 10-40; X is bivalent bonding group or direct bond, preferably isopropylidene group; m and n are 5-20, preferably 5-10) and having a molecular weight of 400-3,000, preferably 500-2,000.

Description

[Detailed description of the invention] [Industrial application fields] The present invention relates to polyamide compositions for molding.

[Prior Art/Problems to be Solved by the Invention] Polyamide resins have excellent mechanical strength and are therefore widely used as engineering plastics in various fields.

However, it has the disadvantage that the tensile elongation becomes small depending on the conditions of use.

One way to solve this drawback is to copolymerize polyalkylene glycol to improve the tensile elongation.
This method reduces tensile strength and heat resistance.

The present invention was made in order to create a composition that provides molded articles with excellent tensile elongation without reducing tensile strength, thermal stability, or impact strength.

[Means for Solving the Problems] The present invention provides: (1) i) (45 to 90% (12%, same below) of ω polyester segment to 100 parts (parts by weight, same below) of polyamide resin) 2) Polyester ether block copolymer consisting of 10-55% of polyalkylene glycol segments with an average molecular weight of 400-3000
35 parts of the polyamide composition.

[Example] Polyamide resins used in the present invention include ε-caprolactam, 6-aminocaproic acid, ω-enantholactam, 7-aminoheptanoic acid, 11-aminoundecanoic acid,
Polymers from 9-aminononanoic acid, α-pyrrolidone, α-piperidone, etc., diamines such as hexamethylene diamine, nonamethylene diamine, undecamethylene diamine, dodecamethylene diamine, metaxylylene diamine, and terephthalic acid, isophthalic acid, adipine. Polymers obtained by polycondensing acids, dicarboxylic acids such as sebacic acid, copolymers of the above monomers, and the like can be used.

The polyester ether block copolymer used in the present invention is a block copolymer consisting of polyester and polyalkylene glycol.

Examples of the pre-λ polyester include polyesters made of terephthalic acid and glycols having 2 to 4 carbon atoms, and examples of glycols having 2 to 4 carbon atoms include ethylene glycol, propylene glycol, and butanediol.

The glycol and terephthalic acid constituting the polyester each contain other glycols (for example, hexanediol, cyclohexane dimetatool, etc.) and other dicarboxylic acids (for example, isophthalic acid, naphthalene dicarboxylic acid, etc.) within a range of 10 mol% or less. It's okay to stay.

The polyalkylene glycol has the general formula fl)
or molecules 2400 to 3000 represented by (I[),
Preferably polyalkylene glycols giving 500 to 2000 polyalkylene glycol segments may be used.

-(HR-0 → "(I) (wherein, R is a C2-C4 hydrocarbon group, ρ is 10-40
represents an integer. ) (In the formula, R represents a 02-C4 hydrocarbon group, X represents a divalent bonding group or a direct bond, and 0 and n each represent 5-4.
Represents an integer of 20. ) Specific examples of those represented by the above general formula (1) include segments from polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and the like.

Specific examples of those represented by the above general formula tU) include, for example, R is a C2-C4 hydrocarbon group such as an ethylene group, a propylene group, a tetramethylene group, Xf)<-C-1-
C) Divalent hydrocarbon preplants such as 12CH2-, -s-, -
o-, -3O2-, -co-1-NY- (wherein, Y is a hydrogen atom, a substituted or unsubstituted alkyl group of CI -cs)
or a direct bond, such as those in which m and n are each an integer of 5 to 20. In addition, X
is −〇− (in the formula, Y is the same as above), −〇− or −
502- is particularly desirable from the viewpoint of moldability. Furthermore, those in which the benzene nucleus is substituted with an alkyl group such as a methyl group or an ethyl group, or a halogen atom can also be used.

Regarding the degree of polymerization of the polyalkylene glycol, from the viewpoint of thermal stability and solvent resistance, ρ is preferably 40 or less, ■ and n are each preferably 20 or less, and from the viewpoint of crystallization properties and impact resistance, g is 10 or more, Each of m and n is preferably 5 or more.

In a preferred embodiment of the present invention, the polyester segment is a polyethylene terephthalate segment, and the polyalkylene glycol segment is a segment represented by the general formula (If).A particularly preferred embodiment is the case where the polyester segment is a polyethylene terephthalate segment and the polyalkylene glycol segment is a segment represented by the general formula (If). is an isopropylidene group, and m and n are each from 5 to 10.

The proportion of polyalkylene glycol segments in the polyester ether block copolymer is 10-55%, preferably 15-50%. If the cough volume is less than 10%, it is not possible to improve the tensile elongation of the molded product, and if it exceeds 55%, the heat distortion temperature,
Tensile strength decreases.

Logarithmic viscosity (I
V) is phenol/tetrachloroethane-50150 (
Weight ratio) in a mixed solvent with a concentration of 0.5 g/dN at 25°C.
The range of 0.5 to 1.4 is preferable. IV is 0.
When the IV is less than 5, the tensile strength decreases, and when the IV exceeds 1.4, phase separation tends to occur during blending. A more preferable IV is 0.6 to 1.2, particularly preferably 0.7 to 1.0.

The amount of the polyester ether block copolymer added to 100 parts of the polyamide resin is 2 to 35 parts, preferably 5 to 30 parts. If the amount is less than 2 parts, no improvement in tensile elongation will be observed, and if it exceeds 35 parts, the tensile strength and heat distortion temperature will decrease.

Although there are no particular restrictions on the method of blending the polyester ether block copolymer with the polyamide, a common method is to melt-knead the polyamide resin and the polyester ether block copolymer using an extruder.

If necessary, the composition of the present invention may contain other known resins such as polyethylene, polypropylene, EP rubber, ethylene-vinyl acetate copolymer, ionomer, ABS resin, nylon, PBT resin, and PET resin. In addition, fillers such as glass fiber, glass peas, carbon fiber, steel fiber, talc, clay, calcium carbonate, calcium sulfate, mica, carbon powder, zinc oxide, titanium oxide, etc. pigment,
Dyes, antioxidants, ultraviolet absorbers, flame retardants, etc. may be added.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto.

In addition, the tensile strength, tensile elongation, and tensile modulus of the test pieces in the examples are ASTM-D638, heat distortion temperature (4.6 kg
/c+J weight) was measured based on ASTM-DB4g, and notched Izot impact strength was measured based on ASTM-D25B.

Thermal stability was determined by the coloration of the resin when it remained in an injection molding machine at 260° C. for 5 minutes. No coloration at all was evaluated as ◎, and slight coloration was evaluated as ◎.

Examples 1 to 3 and Comparative Examples 1 to 2 A polyethylene terephthalate block copolymer (IV-0,80) obtained using 6100 parts of nylon and 30% of an ethylene oxide adduct of bisphenol A (number average molecule ff1looO) was used. After tri-blending in the proportions shown in Table 1, the mixtures were extruded using a twin-screw extruder to form pellets, and test pieces were prepared by injection molding and tested for mechanical strength.

The results are shown in Table 1.

A sample containing no polyester ether block copolymer as Comparative Example 1 and a sample containing 40 parts of the polyester ether block copolymer as Comparative Example 2 were similarly tested. The results are shown in Table 1.

Example 4 Polyethylene terephthalate block copolymer (IV-0,8) obtained using 6100 parts of nylon and 30% of polyethylene glycol (number average molecule H800)
After triblending with 10 parts, the test was carried out in the same manner as in Example 1. The results are shown in Table 1.

Example 5 6100 parts of nylon and polytetramethylene glycol (
polybutylene terephthalate block copolymer (IV
-1,1) After triblending 10 parts, the test was carried out in the same manner as in Example 1. The results are shown in Table 1.

[Margins below] From the results in Table 1, it can be seen that the tensile elongation of molded products using the composition of the present invention is greatly improved, and the tensile strength, heat distortion temperature, and notched Izot impact strength do not decrease. I understand.

[Effects of the Invention] When a molded article is manufactured using the composition of the present invention, a molded article having a large tensile elongation can be obtained without reducing the tensile strength, thermal stability, and impact strength of the polyamide resin molded article.

Claims (1)

[Claims] 1(i) 100 parts by weight of polyamide resin, (ii)
) (a) 45 to 90% by weight of polyester segments and (
b) A polyamide composition containing 2 to 35 parts by weight of a polyester ether block copolymer comprising 10 to 55% by weight of polyalkylene glycol segments having an average molecular weight of 400 to 3,000.