JPS5893750A - Polyester resin composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. which gives moldings having good surface gloss at a low mold temperature, consisting of polyethylene terephthalate, a nucleating agent and a specified amide ester. CONSTITUTION:0.05-10pts.wt. at least one nucleating agent selected from polyamides which have two or more amide bonds per molecule and are not molten nor decomposed at a temp. below 270 deg.C, metal salts of org. acids of formulasI and II (wherein M, M' are each an alkali metal; m,n is each 1 or 2) and talc, and 0.5-10pts.wt. amide ester of formula III (wherein R1, R3 are each a 6- 15C hydrocarbon group; R2 is 7C or lower hydrocarbon group) are blended with 100pts.wt. polyethylene terephthalate having an intrinsic viscosity of 0.4 or above. EFFECT:The compsn. does not contain any components which volatilize during melt kneading or during molding, exhibit excellent moldability even at a low mold temp. of nearly 100 deg.C, and gives moldings having excellent surface gloss and shape retention.

Description

[Detailed description of the invention] The present invention relates to polyester resin compositions.

More specifically, it is a polyester composition for molding with improved surface gloss.By blending a special ester amide compound with a crystal nucleating agent, there are fewer components that evaporate during molding, and the surface gloss is improved even at low mold temperatures. The present invention relates to a polyester composition that can give molded articles with good properties.

Conventionally, when polyethylene terephthalate is used as an injection molded product for plastic applications, the mold temperature used for normal molding, i.e. 70 to 110 degrees Celsius, is extremely low.
When molding was performed using a normal molding die at ℃, a homogeneous molded product with good physical properties could not be obtained. In particular, the shape stability of the molded product is extremely poor, and the surface of the molded product has avatar-like patterns, giving it a dull and rough appearance. Therefore, it is necessary to use a special high-temperature mold for conventional polyethylene terephthalate molding and maintain the temperature at 150'C or higher. At such high mold temperatures, the molding cycle becomes significantly longer, resulting in a large production cost. This is a negative factor. For this reason, it has been necessary to promote the crystallization of polyethylene terephthalate to improve these drawbacks (various countermeasures have been proposed in the past). for example,
Special Publication No. 44-7542 specifically mentions talc? A method of increasing the crystallization rate by blending about 20.2 to 2 weight of a crystal nucleating agent made of inorganic particles as a typical example is shown. Further, Japanese Patent Publication No. 48-4097 discloses a method of blending an alkali metal salt of an organic carbo/acid. However, the nucleating agent added in these methods alone is not sufficient to increase the total crystallization rate of polyethylene terephthalate, and as a result,
When these compositions are used as molding materials, the mold temperature still needs to be as high as 130-140°C or higher. Further, JP-A-54-158452 discloses a composition in which polyethylene terephthalate is combined with glass fiber, an organic carboxylic acid sodium salt, and a low-molecular organic plasticizer. Such a compounding composition promotes the crystallization of polyethylene terephthalate at low temperatures, but when a molding material made of this composition is subjected to injection molding, so-called mold deposits, in which precipitates form in the mold cavity, are observed. Since the low-molecular organic plasticizer used here is volatile, there are many problems such as gas generation when mixed with polyethylene terephthalate and when the resulting mixed material is dried and molded. Ta.

The inventors of the present invention have conducted intensive research to eliminate the drawbacks of conventional polyethylene terephthalate injection molding materials, and as a result, they have arrived at the polyester resin composition of the present invention.

That is, the present invention relates to polyethylene terephthalate) (A
) IQQ parts by weight, Jil agent (n) to, os~10
A polyester composition comprising 0.5 to 10 parts by weight of an amide ester compound (0) represented by the following general formula (1).

al-ooo-a, -NHOO-am (+
) (wherein - and R3 are hydrocarbon groups having 6 to 15 carbon atoms,
a represents a hydrocarbon group having 7 or less carbon atoms. ) Polyethylene terephthalate, which is the uninvented component (A), is a polyethylene terephthalate homopolymer, at least 7
A copolymer containing 0 moles or more of ethylene terephthalate repeating units, or a mixture with an equivalent amount of other polyester, in a mixed solvent with a weight ratio of phenol to tetrachloroethane of 6:4 at 35°C. It is desirable that the intrinsic viscosity determined by is 0.4 or more.

The crystal nucleating agent used as component (B) in the present invention can be various conventionally known compounds, such as those described in the literature Plastics A
Examples include aluminum silicate, aluminum calcium silicate, metal oxides, inorganic powders such as mica, sodium stearate, sodium benzoate, and monomethyl terephthalate. These include sodium salts of organic carboxylic acids such as sodium, sodium salts of copolymers of ethylene and acrylic acid or methacrylic acid, and sodium salts of copolymers of styrene and maleic anhydride. Polyamides in which two or more polyamides are connected and do not melt or decompose at temperatures below 270'C (ii) Metal salts of organic acids represented by the following general formula (1) (where hi and d are the same or They are different alkali metals, and l and m are 1 or 2.) (li) Talc, and particularly preferably (i) + (ii). These nucleating agents are
When polyethylene terephthalate, which is a component of the present invention, is cooled in a mold from a molten state, it has a strong effect of causing crystallization without requiring a long fermentation period, and (0)
It has excellent effects such as a strong synergistic crystallization promoting effect with other components, and less deterioration of component (A) polyethylene terephthalate when these nucleating agents are used.

Here, the polyamides in (:) above are NHArl
0O- NHArc NH- 00Ar3 0O- NHAr4 Co 'Ar6 (wherein, ^rl and Ar11Ar3 are divalent hydrocarbon groups,
Ar4, Ar5 are monovalent hydrocarbon groups) are polyamides in which two or more types of amide-forming groups are connected by amide bonds, and the number of amide bonds in the molecule of the polyamides is 2 or more. , and is a polyamide that does not melt or decompose at temperatures below 270°C.

etc., and Ar4. Examples of Ar5 include λrI, Arc and Ar3 each being a divalent aromatic hydrocarbon group, and Ar4 HAr
Both of 5 are monovalent aromatic hydrocarbon groups, which are excellent in terms of thermal stability as well as effectiveness as a nucleating agent.

These polyamides may be homopolymers, random copolymers, block copolymers, or may be block copolymers or graft copolymers with other polymers, but the polyamides do not melt or decompose at temperatures below 270°C. especially preferably 30
It does not melt or decompose at temperatures below 0°C.

The sum of the numbers of amide bonds in the polyamide molecules is 2 or more, and there is no particular upper limit. However, these polyamides as crystal nucleating agents need to be dispersed in an extremely fine state in polyethylene terephthalate, which is component (A). A method of precipitating the solution with a coprecipitant to make it easier to disperse and blending it with component #, (^),
There is a method of solution blending the Ml of polyamides with a solution of polyethylene terephthalate, which is component (A), but for oligoamides having 2 to 6 amide bonds in the polyamide molecule, a strong mixer, for example 2 Direct melt blending can be achieved by a mixer in which screws rotate in the same or different directions.

(Margin below) etc.

(Hereinafter referred to as fU) Examples of the metal salt of aromatic oxy/sulfonic acid represented by the general formula (Otori) or (11) include disodium para-phenolsulfonate, disodium 2-naphthol-6-sulfonate, Examples include sodium, disodium 2-naphthol-8-sulfonate, atrasodium resorcin-4,6-disulfonate, and trisodium 2,3-7taledio-6-sulfonate. The above general formula (
In order to blend the compound represented by 1) or (1) into polyethylene terephthalate, it is preferably carried out at any stage during the esterification reaction, transesterification reaction or polycondensation reaction in the manufacturing process of polyethylene terephthalate. Even if the compound of general formula (1) or (Rin) is blended after the completion of polycondensation of terephthalate, the crystallization rate will not become too high.

The blending amount of these crystal nucleating agents is 0.05 to 10 parts per 100 parts by weight of polyethylene terephthalate, and lOs
Above this level, the melt viscosity becomes high and mold deposits are caused, which is unfavorable in terms of molding.

The compound is a compound selected from the compounds represented by the general formula 2〇〕, and in these ester amide compounds, among the three hydrocarbons that constitute the general formula (+), the hydrocarbon groups at both ends are aromatic rings or alicyclic rings. It is a hydrocarbon group containing 1@. These ester amide compounds are preferably those that do not decompose even at about 300°C and do not react with polyethylene terephthalate, which is component (A). For example, in the compound represented by the general formula (+), "1 and a are the same or different, and these aromatic rings or cyclohexane rings may be substituted with an alkyl group, an alkoxy group, or a halogen atom Yanitro group. Preferred examples of compounds of general formula (1) are as follows.

These amide ester compounds can be synthesized by using various conventionally known methods for forming amide bonds and ester bonds.

For example, to give a specific example, acid chloride is prepared using thionyl, and the blending amount of the esteramide compound (0) is the amount of polyethylene tele-7 (lambda). The amount is 0.5 to 10 parts by weight, preferably 1 to 8 parts by weight, based on 100 parts by weight of tallate. If this amount is less than 1 part by weight of O,S, it is difficult to obtain a molded product with excellent gloss, and if it exceeds 10 parts by weight, mold deposits and other undesirable toranols may occur in the molding process. .

The composition of the present invention as described above contains an ester amide compound as a component (C) together with a crystal nucleating agent as a component (B).
By blending it with the component polyethylene terephthalate, a molded product with good surface gloss and good shape stability can be obtained even when molded at a mold temperature of around 100°C. It has been shown that it has the effect of facilitating the alignment of polyethylene terephthalate and promoting crystallization over a wider temperature range. In addition, it has the advantage that not only is it not volatile, it does not generate gas due to decomposition products and is less likely to escape during kneading with component (A) polyethylene terephthalate or during heating operations such as molding. are doing.

The composition of the present invention can be prepared by any commonly used method. For example, a mixture obtained by adding a crystal nucleating agent of component (g) during polymerization of polyethylene terephthalate of component (A) and (0)
It can be prepared by compounding the component esteramide compounds using an extruder, by triblending, by compounding all the components at the same time using an extruder, and the like.

The composition of the present invention may contain various additives, such as reinforcing fillers, antioxidants, etc., depending on the purpose and B. Various components such as ultraviolet absorbers, lubricants, mold release agents, heat retardants, antistatic agents, and colorants can be blended.

Examples of reinforcing fillers include fibrous organic and inorganic substances such as aramid fibers, 2-glass fibers, carbon fibers and asbestos fibers, and non-fibrous inorganic substances such as talc and mica. A particularly preferred example of these reinforcing fillers is glass fiber. In addition, the amount of these reinforcing fillers blended is 5 to 60% by weight based on the total weight of the composition, and if it is less than 5% by weight, the provision of shape stability is insufficient;
If it exceeds 0% by weight, brittleness increases and practical value decreases.

The composition of the present invention thus obtained exhibits excellent moldability not only when molded in a high-temperature mold, but also when molded in a low-temperature mold around 100°C, and has excellent surface gloss and shape. In addition to providing molded products with good stability,
The composition does not contain components that volatilize during melt mixing and molding. In this way, it has the ability to be molded and processed at low temperatures, which is rarely possible with conventional polyethylene terephthalate, and together with its inherent heat resistance and chemical resistance, it is extremely useful as an industrial resin. When manufacturing resin,
Even when it is dried, molded, and put into practical use, it has almost no volatile components, making it an excellent resin in terms of occupational hygiene.

Next, the present invention will be explained using examples.

Example-1 64 parts by weight of polyethylene terephthalate with an intrinsic viscosity of 0.7, 1 part by weight of talc (1Ms type Nippon Talc) as a crystal nucleating agent, and a glass chop strand (1-uA4z98j Asahi Fiberglass Co., Ltd.) with a length of 3cm ) and 5 parts by weight of the amide compound were mixed in a rotary drum blender. Next, this was put into the hopper of a 70 wmyi pent type extruder, and the cylinder temperature was 260-280-280.
The mixture was melt-mixed and pelletized at 'C. The obtained pellet was dried under reduced pressure for 5 hours using T-140'C, and the cylinder temperature was 270-280°C using an injection molding machine manufactured by KO-201 Kawaro Iron Works.
280℃, injection pressure 30-6okyIi, cooling time 10
A human STM No. 1 dumbbell test piece was molded at a mold temperature of 80 to 150° C. with a molding cycle of 25 seconds. Mold deposit and mold releasability are determined by observing the mold surface after continuous 3° shots, and mold releasability is determined by the drop rate due to protrusion from the mold! expressed.

The surface gloss was determined by measuring the center part of the obtained dumbbell test piece.
Measured at an angle of 20 degrees based on TM-D-528. The heat shrinkage rate was determined from the following formula, where the length dimension of the dumbbell test piece after molding was Ll, which was the 0 length dimension after heat treatment at 120'C in an air oven for 15 hours.

L (1-L.

Heat shrinkage rate (chronic) --X 100 O Tensile strength was measured based on A8TM-D-638.

In addition, as a method for measuring the amount of volatilization that occurs during heating, a dumbbell test piece obtained by molding is crushed, and the powder of 100 mesh baths is heated at 150°C using an IR moisture measuring needle.
The weight change rate was determined by measuring the weight ωo1 before heating and the weight ωo1 after heating, and using the following equation. These results are shown in Table-3.

Weight change rate (chi) = -X 100 ωO Comparative Example-1 An experiment similar to Example-1 (the compounding composition is shown in Table-1) without using a crystal nucleating agent and an esteramide compound (c-conducted) The results are shown in Table 3, and even when molded at a high mold temperature of 150°C, the surface gloss, mold release rate, and shrinkage rate were extremely poor.

Comparative Example 2 An experiment similar to Example 1 was conducted (the blending composition is shown in Table 1) except that an esteramide compound was added but no crystal nucleating agent was used. Results 1 are shown in Table 3.

Comparative Example 3 An experiment similar to Comparative Example 2 was carried out using a mixture composition of ester amide compound No. 9 and known noester 4-1. The results are shown in Table 3, and it was found that there were significantly more volatile components during heating compared to Example 1.

Comparative Example 4 An experiment similar to Example 1 was conducted using the formulation shown in Table 1, except that talc was used as the crystal nucleating agent and no esteramide compound was used. The results are shown in Table-3. At a mold temperature of 120° C., the molded product has poor surface diiiift, roughness, and heat shrinkage, as well as poor mold releasability.

Examples-2 to 10 p-phenol sulfonic acid dinoda (also ij: 2-su7)-6-sulfo/acid disoda) was added during polyethylene terephthalate polymerization, that is, 2000 parts of dimethyl terephthalate, 1420 parts of ethylene glycol, p- 20 m of sodium phenolsulfonate, 1.0 part of manganese acetate, antimony trioxide, and Os were charged into a reactor, and transesterification was carried out at 190°C for 3 hours under a nitrogen stream to distill off most of the methanol. -, then add 0.03 part of heat stabilizer (tetrimethyl phosphate), and then add 2 parts of heat stabilizer.
The temperature was raised to 50°C and the pressure was reduced to 0.5■Hg (7) under a vacuum of 27
Polycondensation reaction was carried out at 0°C for 4 hours. The obtained polycondensate was white, had a melting point of 253 to 258°C, and an intrinsic viscosity of 0.60. This polycondensate, other compounding agents, and various esteramide compounds were pelletized and evaluated in the same manner as in Example 1 with the composition shown in Table 1. The results are shown in Table 3.
Shown below.

Example-11 Example-1 was prepared by adding talc as a crystal nucleating agent and other additives to the polycondensate obtained in Example-2 with the composition shown in Table-1.
It was pelletized and evaluated in the same manner as above. The results are shown in Table-3.

Example-12, 13 10 parts by weight of poly-para-phenylene terephthalamide solution polymerized in N-methylpyrrolidone (crystal nucleating agent)
After the completion of the polycondensation reaction, 25 parts by weight of polyethylene terephthalate adipate (TAR; terephthalyl/adipine l!l/ethylene glycol = 60/40/100 molar ratio) was added to a solution of poly-para-phenylene terephthalamide, Co-precipitated with methanol. This was filtered, washed with methanol and water, and heated to 90°C for 5 minutes.
Vacuum dried for hours. The resulting coprecipitate contained about 30 units of polyvalent monoylene terephthalamide.

3.5 parts by weight of this coprecipitate and other ingredients were weighed in the proportions shown in Table 2, melt-mixed with polyethylene terephthalate in the same manner as in Example 1, pelletized, and evaluated. The results are shown in Table-4.

Examples 14, 15, 16 Using polyethylene prephthalamide instead of poly-para-phenylene terephthalamide in Example 1l,
Experiment similar to Example-1l (composition is shown in Table-2)
I did it. The results are shown in Table 4.

Example-17 Using polyparabenzamide instead of poly-para-phenylene terephthalamide in Example-11, Example-11
An experiment similar to that (the composition is shown in Table 3) was conducted. The results are shown in Table 4.

Examples 18 to 21 Experiments similar to Example 1 were carried out using oligomers of para-phenylene terephthalamide instead of poly-para-phenylene terephthalamide in Example z (composition composition Table 2). ) was carried out.

The results are shown in Table-4.

(Hereafter, extra colors)

Claims (1)

[Claims] 1. 100 parts by weight of polyethylene terephthalate (A), parts by weight of crystal nucleating agent (s) o, os to lO, the following:
Amide ester compound (O) represented by general formula 0)
Polyester composition J consisting of parts by weight of O, S to lO
000 R2NHOOR-i (1) (wherein,
al and s are hydrocarbon groups having 6 to 15 carbon atoms, R2 is a hydrocarbon group having 7 or more carbon atoms; Any one of polyamides that are linked together as above and do not melt or decompose below 270°C, (11) the following general formula (door), a metal salt of an organic acid represented by (2)), and (■) Merck. The polyester resin composition according to claim 1, which is a species or two or more species (wherein M, l/ are the same or phase, different alkali metals, and 2m is 1 or 2) crystals. Nucleating agent (B
) are connected by two or more amide bonds and do not melt or decompose at temperatures below 270°C, and the polyamides are polyamides in which two or more of the amide-forming groups represented by the following general formula % are amide bonds. The polyester resin composition according to claim 2, which is a linked polyamide (wherein Arl, kf,
(kf3 is a divalent hydrocarbon group, Ar41A r6 is a monovalent hydrocarbon group) Claim 2, wherein the crystal nucleating agent (B) is an oxysulfonic acid metal salt having the following general formula: The polyester resin, resin composition & crystal nucleating agent (B) has the following general formula: NHArl 0O- NHAr2 NH- 00Ar3 0O- NHAr4 and 100-murs, ArI, Ar2. Ar3 is a divalent aromatic hydrocarbon group, Ar4. The polyester resin composition according to claim 3, wherein Ars is a monovalent aromatic hydrocarbon group.