JPH0717823B2 - Thermoplastic polyester block copolymer composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a modified high viscosity viscous polyester copolymer suitable for extrusion molding of hollow molded products such as bellows, modified cross-section molded products such as moldings, tubes and hoses. It relates to a combined composition.

(Prior Art) As a method for modifying a thermoplastic polyester copolymer, a method using a polyisocyanate compound as a chain extender (U.S. Patent Office Defense Publication No. T-908011, JP-A-52-12)
1699 and JP-A-57-78413), and a method using a polyepoxy compound (JP-A-48-100495).
There is.

(Problems to be solved by the invention) It is difficult to control the melt viscosity by a method of modifying a thermoplastic polyester copolymer with a polyisocyanate compound or a polyepoxy compound by a chain extender, and unreacted polyisocyanate in the modified polymer is difficult to control. If the nato compound or polyepoxy compound remains, a re-reaction will occur during molding of this composition, resulting in a product with a large variation in performance. In addition, there is a case where the viscosity is excessively increased during the modification, the molecular weight is remarkably increased in a part, and in some cases, an insoluble gelled product is generated.As a result, the bending fatigue resistance of the resin is centered on the gelled part. Markedly reduced.

(Means for Solving the Problems) The present invention relates to a thermoplastic polyester block copolymer having a polyoxazoline compound of 0.01 to 2 having two or more oxazoline groups.
It is to obtain a thermoplastic polyester block copolymer composition containing 10 parts by weight and 0.01 to 5 parts by weight of an organic acid anhydride. With the composition of the present invention, a resin having a uniform melt viscosity and a stable melt viscosity can be obtained. On the other hand, virtually no re-thickening occurs even if the obtained composition is heated and melted for molding. Further, since the thickening is uniform, there is almost no partial excessive thickening, that is, gelation, so that the molded article has excellent flex fatigue resistance. Further, no yellowing due to light or heat as observed when using a polyisocyanate compound is observed.

The thermoplastic polyester block copolymer in the present invention is a thermoplastic polyester block copolymer composed of a polyester segment having a melting point of 150 ° C. or higher and a polylactone segment. The polyester that constitutes the polyester segment with a melting point of 150 ° C or higher is terephthalic acid,
Isophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, p-benzoic acid, bis (p-carboxyphenyl) methane, 4,4'-sulfotyldibenzoic acid, etc. And the residue of aromatic dicarboxylic acid of ethylene glycol, propylene glycol, tetramethylene glycol, pentamethylene glycol, 2,2-dimethyltrimethylene glycol, hexamethylene glycol, decamethylene glycol, p
-A polyester consisting of a diol residue such as xylylene glycol or cyclohexanedimethanol, a copolyester using two or more kinds of these dicarboxylic acids or two or more kinds of diols, or p- (β-hydroxyethoxy) benzoic acid, Polyesters derived from oxyacids such as p-oxybenzoic acid and residues thereof, polylactones such as polypivalolactone, 1,2-bis (4,4′-dicarboxymethylphenoxy) ethane,
Polyetherester consisting of the residue of an aromatic ether dicarboxylic acid such as di (4'-carboxyphenoxy) ethane and the above-mentioned diol residue, and a combination of the above-mentioned dicarboxylic acid, oxyacid, diols, etc. Among the copolyesters, those having a melting point of 150 ° C. or higher can be mentioned. Polyethylene terephthalate is particularly preferable.

The suitable molecular weight of the polylactone segment is 400 to 6000, and the ratio in the polyester block copolymer is 5 to 80.
% By weight.

These polyester block copolymers can be produced by an ordinary polycondensation method. A preferred method is to heat the aromatic dicarboxylic acid or its dimethyl ester, the low melting point segment-forming diol and the low molecular weight diol to about 150 to 260 ° C. in the presence of a catalyst to carry out an esterification reaction or transesterification, and then A method for obtaining a polyester copolymer by carrying out a polycondensation reaction while removing excess low-molecular-weight diol under vacuum, a pre-prepared high-melting point polyester segment-forming prepolymer and a polylactone segment-forming prepolymer containing those prepolymers. A method of obtaining a polyester copolymer by mixing a bifunctional chain extender that reacts with a terminal group of a polymer, reacting the mixture, and then removing the volatile components by keeping the system in a high vacuum, and a polyester having a high degree of polymerization and a high melting point. And lactones are heated and mixed, and transesterification reaction is carried out while ring-opening polymerization of lactone. And a method of obtaining a polyester copolymer by causing.

Among them, the thermoplastic polyester copolymer particularly suitable for the present invention has a high melting point polyester segment of polybutylene terephthalate, or 5 to 50 parts by weight of butylene isophthalate based on 100 parts by weight of polybutylene terephthalate, and has a low melting point. It is a polyester / polyester type block copolymer having a polylactone segment as a polymer segment.

The polyoxazoline compound used in the present invention has a general formula: (However, n is an integer of 2 or more. X is an alkyl group, an aromatic ring,
Organic compounds composed of alicyclic rings. ) Is a polyoxazoline compound having two or more oxazoline groups, and n is preferably 2 to 3. For example, 2,2 '- (1,3-phenylene) - bis (2-oxazoline), 2,2' △ ² - and the like bisoxazoline. In addition, a small amount of monooxazoline may be used together to control the degree of thickening.

Examples of the organic acid anhydride used in the present invention include succinic anhydride, maleic anhydride, phthalic anhydride, pyromellitic anhydride, and mellitic anhydride. Preferably, organic acid anhydrides having two or more anhydrides in the molecule such as pyromellitic anhydride and mellitic anhydride are effective, and those which themselves act as a chain extender are preferable. Here, regarding the amount ratio of the polyoxozoline compound and the organic acid anhydride, the content of either the polyoxazoline compound or the organic acid anhydride is 100 parts by weight of the thermoplastic polyester block copolymer.
If it is 0.01 part by weight or less, the effect of chain extension is low and flex fatigue resistance cannot be improved. Further, when the amount of the polyoxazoline compound exceeds 10 parts by weight, the excess polyoxazoline compound serves as a plasticizer, and the surface hardness of the product decreases. Further, since the polyoxazoline compound is deposited over time, the surface property is significantly deteriorated.

In the present invention, the polyoxazoline compound and the organic acid anhydride can be contained at any stage from the polymerization of the thermoplastic polyester block copolymer to the compound, but the stabilizer and the colorant are preblended with a tumbler at the time of the compound. After being melt-mixed with a single-screw or twin-screw extruder generally in a temperature range of 180 to 250 ° C., chips are obtained by a series of processes of cooling, solidification and granulation. Granulation methods include a method of extruding into a sheet into chips using a dicer, a method of discharging strands into the air and immediately cooling with water followed by chipping with a pelletizer, and a method of cutting into chips immediately after discharging by an underwater cutter or hot cut.

Although the composition of the present invention has many desirable properties, the above properties can be remarkably easily stabilized by adding a stabilizer against ultraviolet rays, a stabilizer against thermal oxidation and a stabilizer against hydrolysis. Typical of those useful as stabilizers are substituted benzophenones or substituted benzotriazoles as stabilizers against ultraviolet rays, and phenol derivatives such as tetrakis [methylene-3 (3,5-diethanol) as stabilizers against thermal oxidation. -Syalybutyl-4'-hydroxyphenyl) propionate] methane, 1,3,5-trimethyl-2,4,6-tris [3,5-di-sialy-butyl-4-hydroxybenzyl] benzene, 4,4 Aromatic amines such as'-thiobis (3-methyl-6-tert-sialybutylphenol) and 4,4'-butylidenebis (6-tertiarybutylmethacresol), for example 4,4 '-(α, α-dimethylbenzyl) diphenylamine, N, N′-diphenyl-p-phenylenediamine, N, N ′-, bis (β-naphthyl) paraphenylenediamine, N, N′-bis There are thiodibropionate esters such as (1-methylheptyl) -paraphenylenediamine and the like, such as dilauryldithiopropionate and distearyldithiopropionate. Also, combinations of these are useful. Examples of stabilizers against hydrolysis include carbodiimides.

The composition of the present invention includes a lubricant, an antistatic agent, a plasticizer, an inorganic and organic powder filler, an organic and inorganic fibrous filler, a flame retardant, and an organic and inorganic pigment, and a brightening agent depending on the purpose. Etc. can also be blended. These compounds can be compounded at any stage from polymerization to compound.

Production Examples A and B The polymers used in Examples and Comparative Examples are as follows.

Polymer A: 100 parts by weight of polybutylene terephthalate and ε
A polyester-polyester block copolymer was produced by heating and mixing 50 parts by weight of caprolactone and subjecting the lactone to ring-opening polymerization and transesterification. A melt index of 40g / 10min, an acid value of 35eq / 10 ⁶ g
Met.

Polymer B: A polyester-polyester block copolymer having the same composition as that of Polymer A was produced under the conditions that the ring-opening polymerization and the transesterification reaction were shortened. Melt index is
It was 45 g / 10 min and the acid value was 17 eq / 10 ⁶ g.

Various properties of the polymers of Production Examples A and B are shown in Table 1.

(Examples) Hereinafter, the present invention will be described with reference to Examples. In the examples, "parts" means "parts by weight".

Surface hardness: JIS K6301 Tensile strength; same as above (JIS No. 3 dumbbell, t = 2mm used) Stretching; same as above (same as above) Melt index; JIS K7210, △ MI = 230 ℃ The value obtained by subtracting the MI of R, fluctuation within lot = heat aging resistance; high elongation JIS K6301 (JIS No. 3 dumbbell, t =
2mm use) Gear type aging type tester 150 ℃, 10 days treatment boiling water resistance; strong elongation to JIS K6301 (JIS No. 3 dumbbell, t =
2mm treatment) Treated in boiling water for 5 days Grease resistance; strong elongation to JIS K6301 (JIS No. 3 dumbbell,
t = 2mm used) Treated in grease (Molelex No. 2) at 120 ℃ for 10 days Flexing fatigue resistance; JIS K6301 Number of flexing cycles until crack reaches 10mm Example 1 Polymer A 100kg 2,2 (1,3 -Phenylene) -bis (2-oxazoline) (hereinafter, 1,3-PBO) (0.15 kg) and pyromellitic dianhydride (0.1 kg) were added, melt-mixed with a single-screw extruder and discharged, and then solidified into a strand in a water tank. Then, it was made into chips. After drying this chip, it was molded into a plate of 100 × 50 × 2t.

Example 2 To 100 kg of Polymer A, 1 kg of 1,3-PBO and 0.4 kg of pyromellitic dianhydride were added, melt-mixed with a single-screw extruder, discharged, and then solidified into a strand in a water tank and then made into chips. After drying this chip, it was molded into a plate of 100 × 50 × 2t.

Example 3 Chips were formed in the same manner as in Example 2 except that 9 kg of 1,3-PBO and 8 kg of pyromellitic anhydride were used, and then formed into a plate.

Comparative Example 1 1,5-PBO and 0.005 kg of 1,3-PBO and 0.005 kg of pyromellitic anhydride were added to 100 kg of each polymer A to form chips in the same manner as in Example 1, and then molded into plates.

Comparative Example 2 To 100 kg of Polymer A, 11 kg of 1,3-PBO and 12 kg of pyromellitic dianhydride were added, chips were formed in the same manner as in Example 1, and then molded into a plate.

Table 1 shows polymer A and resin properties and evaluation results of Examples 1 and 2 and Comparative Examples 1 and 2. It can be seen that the chips of Examples 1 and 2 not only have a higher melt viscosity (MI) than the raw material polymer A, but also have less variation, a small ΔMI, and a high melt viscosity stability.

On the other hand, in the chips of Comparative Examples 1 and 2, the MI did not become so high, the variation was large, the ΔMI was large, and the stability of the melt viscosity was low.

Further, in the evaluation of the molded plate, in Examples 1 and 2, the effect of improving heat aging resistance, boiling water resistance, grease resistance, bending resistance, etc. is remarkable, but in Comparative Example 1, the effect is small.

Further, on the surface of the plate of Comparative Example 2, white powder was observed to deposit after being left for 24 hours.

(Effects of the Invention) As is apparent from the examples and comparative examples, in the present invention, a thermoplastic polyester block copolymer containing a polyoxazoline compound having two or more oxazoline groups and an organic acid anhydride can be used for hollow molding or A thermoplastic polyester copolymer composition having a high melt viscosity suitable for extrusion processing, a small change in viscosity, and excellent durability can be obtained, which has great industrial significance.

Claims (1)

[Claims] 1. A polyoxazoline compound having 2 or more oxazoline groups in an amount of 0.01 to 10 parts by weight and an organic acid, based on 100 parts by weight of a thermoplastic polyester block copolymer having a melting point of 150 ° C. or higher and a polyester segment and a polylactone segment. A thermoplastic polyester block copolymer composition comprising 0.01 to 5 parts by weight of an anhydride.