JPH04323253A - Polyester composition - Google Patents

Abstract

PURPOSE:To obtain a polyester composition, hardly decomposing and capable of readily providing molded bodies without deteriorating mechanical properties even in exposure to high temperatures for a long period. CONSTITUTION:A polyester composition is obtained by blending (A) a polyester composed of (A1) an aliphatic dicarboxylic acid (e.g. oxalic acid or malonic acid) expressed by formula I [n is 0-10], (A2) an aliphatic diol (e.g. ethylene glycol or polyethylene oxide) and (A3) a dihydroxy compound (e.g. 4,4''dihydroxy- p-terphenyl) expressed by formula II [R<1> and R<2> are alkylene; p is 3 or 4; q and r are 0 or integers of >=1] and/or a monohydroxy compound (e.g. 4-hydroxy- p-terphenyl) expressed by formula III [R<3> is alkylene; l is 2 or 3; m is 0 or an integer of >=1]as constituent components with (B) 0.05-5wt.% tri- or polyfunctional epoxy compound (e.g. trimethylolpropane triglycidyl ether).

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composition capable of producing a polyester molded article having properties as a thermoplastic elastomer, and particularly having excellent thermal stability and hydrolysis resistance.

0002

2. Description of the Related Art Thermoplastic elastomers exhibit rubber elasticity at room temperature and can be molded, so they are widely used in various industrial products. In particular, polyesters containing dihydroxy or monohydroxy compounds having p-terphenyl or p-quarterphenyl skeletons,
A thermoplastic elastomer with excellent mechanical properties can be provided,
The present applicant has already filed an invention regarding a resin composition containing this polyester (for example, Japanese Patent Application No. 2-256353
issue).

0003

[Problems to be Solved by the Invention] In order to prepare the above resin composition, it is necessary to melt and knead the polyester and other additives at a high temperature, and the molding is also carried out at a relatively high temperature. In addition, the obtained polyester molded product has an excellent heat distortion temperature, so it is expected to be used in a high-temperature atmosphere.

However, when a resin composition is melt-kneaded for a long time or a polyester molded product is used at high temperatures, the polyester is decomposed and the molecular weight decreases, resulting in a decrease in the mechanical properties of the molded product. Ta. In particular, when handled at high temperatures and high humidity, the molecular weight decreases significantly.

In order to reduce such deterioration of resins, attempts have been made to add additives such as hindered phenol antioxidants and phosphoric acid stabilizers. However, although such a method is effective to some extent, it has limitations.

The present invention was made to solve the above-mentioned conventional drawbacks, and its purpose is to create a polyester molded product that is resistant to thermal decomposition and whose mechanical properties do not deteriorate even when exposed to high temperatures for a long time. The object of the present invention is to provide a polyester composition that can be easily obtained.

[0007]

[Means for Solving the Problems] The present inventors have discovered that stability at high temperatures can be improved by using polyester and a trifunctional or higher functional epoxy compound in combination, and have completed the present invention.

The polyester composition of the present invention comprises an aliphatic dicarboxylic acid whose general formula is represented by the following formula [I]; an aliphatic diol; and a dihydroxy compound whose general formula is represented by the following formula [II]; and a dihydroxy compound whose general formula is represented by the following formula [III]. ] A polyester containing at least one of the monohydroxy compounds represented by the following as a constituent component, and a trifunctional or more functional epoxy compound, and the epoxy compound accounts for 0.05% to 5% by weight based on the polyester. It is contained in a proportion of .00% by weight, thereby achieving the above object.

HOOC-(CH2)n-COOH
[I] (In the formula, n represents an integer from 0 to 10.)

[
0010

[Chemical formula 3]

(In the formula, R1 and R2 independently represent an alkylene group, p is 3 or 4, and q and r independently represent an integer of 0 or 1 or more.)

0012

[C4]

(In the formula, R3 represents an alkylene group, l is 2 or 3, and m is an integer of 0 or 1 or more.)

The polyester used in the present invention has properties as a thermoplastic elastomer, has excellent heat resistance and mechanical properties, and is also excellent in moldability.

If a dicarboxylic acid having more than 10 carbon atoms is used among the aliphatic dicarboxylic acids mentioned above, the physical properties of the molded article obtained from the polyester will deteriorate. Examples of the dicarboxylic acids include oxalic acid, malonic acid, succinic acid,
Glutaric acid, adipic acid, suberic acid, and sebacic acid are preferably used.

[0016] Examples of the aliphatic diols include glycols and polyalkylene oxides. Examples of the above glycol include ethylene glycol, propylene glycol, trimethylene glycol, 1,4-butanediol, 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol. Diol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, cyclopentane-1,2-diol, cyclohexane-1,2-diol, cyclohexane-1,3-diol, cyclohexane- 1,4-diol, cyclohexane-1,4-
Examples include dimethanol, which may be used alone or in combination of two or more.

[0017] Examples of the above polyalkylene oxide include polyethylene oxide, polypropylene oxide, polytetramethylene oxide, polyhexamethylene oxide, etc., and these may be used alone or in combination of two or more. good. The number average molecular weight of the polyalkylene oxide is 100 to 20,000, because if it becomes small, the ability to impart flexibility to the polyester produced will decrease, and if it becomes too large, the physical properties such as thermal stability of the polyester obtained will decrease. is preferable, and more preferably 500 to 5,000.

In the dihydroxy compound represented by the above formula [II], the alkylene groups R1 and R2 are preferably an ethylene group or a propylene group, q and r are preferably 0 or 1, and the compound is represented by the following formula [A]. 4,4''-dihydroxy-p-terphenyl, 4,4''-dihydroxy-p-quarterphenyl represented by the following formula [B], 4,4'' represented by the following formula [C] '-di(2-hydroxyethoxy)-p-quarterphenyl and the like are preferably used.

[0019]

[C5]

The melting point of 4,4''-dihydroxy-p-terphenyl [A] is 260°C, and that of 4,4''-dihydroxy-p-quarterphenyl [B] is 33°C.
6 °C, 4,4'''-di(2-hydroxyethoxy)
-p-Quarterphenyl[C] has a temperature of 403°C. Each of the above dihydroxy compounds [II] may be used alone or in combination.

Dihydroxy compound [II] has high crystallinity, and as mentioned above, it has 4,4''-dihydroxy-p-terphenyl [A], 4,4''-dihydroxy-p-
Quarter phenyl [B] and 4,4'''-di(2-
hydroxyethoxy)-p-quarterphenyl [C]
Because of their high melting points, when these dihydroxy compounds [II] are incorporated into the polymer chain, the polymers exhibit unique properties. That is, since the dihydroxy compound [II] exhibits crystallinity and has a high melting point, a strong and highly heat-resistant physical crosslink is formed even when the amount of the dihydroxy compound [II] is small. As a result, it is presumed that a thermoplastic elastomer with high heat resistance can be obtained without impairing the flexibility derived from the soft segment.

The monohydroxy compounds represented by the above formula [III] are rigid low-molecular compounds having a paraphenylene skeleton, and the melting points of these compounds are extremely high reflecting their characteristic molecular structure. Therefore, when the above-mentioned monohydroxy compound [III] is incorporated at the end of the polymer, very strong and highly heat-resistant physical crosslinking is produced, and a thermoplastic elastomer with excellent heat resistance is produced.

In the monohydroxy compound represented by the above formula [III], R3 is preferably an ethylene group or a propylene group, and n is preferably 0 or 1. As the monohydroxy compound, for example, 4-hydroxy-p
-terphenyl, 4-hydroxy-p-quarterphenyl, 4-(2-hydroxyethoxy)-p-terphenyl, 4-(2-hydroxyethoxy)-p-quarterphenyl, and the like. The monohydroxy compounds [III] may be used alone or in combination.

A polyester consisting of at least one of the above aliphatic dicarboxylic acid [I], an aliphatic diol, a dihydroxy compound [II], and a monohydroxy compound [III], a polysilicone having two hydroxyl groups, and a lactone. , and aromatic hydroxycarboxylic acid may be contained as constituent components.

The above-mentioned polysilicone has two hydroxyl groups, preferably a polysilicone with two hydroxyl groups at the ends of the molecule, such as dimethylpolysiloxane and diethyl polysiloxane, which have two hydroxyl groups at both ends of the molecule. Examples include polysiloxane and diphenylpolysiloxane. As the number average molecular weight of polysilicone decreases, its ability to impart flexibility to the resulting polyester decreases.
As the size increases, it becomes difficult to produce polyester.
100 to 20,000 is preferable, more preferably 5
00 to 5,000.

The above-mentioned lactone reacts with an acid and a hydroxyl group by ring-opening and adds an aliphatic chain, which imparts flexibility to the polyester, and which has four or more carbon atoms in the ring. It is preferable to have a 5- to 8-membered ring, and examples thereof include ε-caprolactone, δ-valerolactone, and γ-butyrolactone.

The above-mentioned aromatic hydroxycarboxylic acids impart rigidity and liquid crystallinity to polyester, and include salicylic acid, metahydroxybenzoic acid, parahydroxybenzoic acid, 3-chloro-4-hydroxybenzoic acid, and 3-bromo-benzoic acid. 4-hydroxybenzoic acid, 3-methoxy-4-hydroxybenzoic acid, 3-methyl-4-hydroxybenzoic acid,
Examples include 3-phenyl-4-hydroxybenzoic acid, 2-hydroxy-6-naphthoic acid, 4-hydroxy-4'-carboxybiphenyl, and preferably parahydroxybenzoic acid, 2-hydroxy-6-naphthoic acid, 4-
Hydroxy-4'-carboxybiphenyl.

Furthermore, the above polyester may contain an aromatic diol or an aromatic dicarboxylic acid other than the dihydroxy compound [II] as a constituent component in order to improve the mechanical properties of the polyester.

Examples of the aromatic diol include hydroquinone, resorcinol, chlorohydroquinone, bromohydroquinone, methylhydroquinone, phenylhydroquinone, methoxyhydroquinone, phenoxyhydroquinone, 4,4
'-dihydroxybiphenyl, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxybenzophenone, 4,
4'-dihydroxydiphenylmethane, bisphenol A, 1,1-di(4-hydroxyphenyl)cyclohexane, 1,2-bis(4-hydroxyphenoxy)
Ethane, 1,4-dihydroxynaphthalene, 2,6
-Dihydroxynaphthalene, etc. Examples of the aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, metal salts of 5-sulfoisophthalic acid, 4,4'-dicarboxybiphenyl, 4,4'-dicarboxydiphenyl ether, and 4,4'-dicarboxydiphenyl sulfide. , 4,4'-dicarboxydiphenylsulfone, 3,3'-dicarboxybenzophenone, 4,4'-
Examples include dicarboxybenzophenone, 1,2-bis(4-carboxyphenoxy)ethane, 1,4-dicarboxynaphthalene, and 2,6-dicarboxynaphthalene.

[0030] In the polyester composed of the dihydroxy compound [II], an aliphatic diol, and an aliphatic dicarboxylic acid, when the content of the dihydroxy compound [II] decreases, the heat resistance decreases, and when the content increases, the elastic modulus increases and the flexibility decreases. The content of the dihydroxy compound [II] is preferably 0.1 to 30 mol%, more preferably 0.5 to 30 mol% of the total monomers constituting the polyester. It is 20 mol%, more preferably 1.0 to 10 mol%. still,
When polyalkylene oxide or polysilicone is used as a non-aromatic diol, its constituent unit is counted as one monomer. That is, polyethylene oxide with a degree of polymerization of 10 is counted as 10 monomers.

[0031] Furthermore, the above monohydroxy compound [III
], aliphatic diol, and aliphatic dicarboxylic acid, when the content of monohydroxy compound [III] decreases, the heat resistance decreases, and when the content increases, the molecular weight of the polyester does not increase sufficiently, resulting in poor physical properties. 0.1 of all monomers constituting polyester
It is preferable to set it as 20 mol%. In addition, the above dihydroxy compound [II] and monohydroxy compound [III]
In a polyester composed of an aliphatic diol and an aliphatic dicarboxylic acid, the heat resistance decreases when the content of the hydroxy compound, which is a combination of the dihydroxy compound [II] and the monohydroxy compound [III], decreases, and when the content increases, the flexibility decreases. and 0.1 to 30 mol% of the total monomers constituting the polyester because a sufficient increase in molecular weight cannot be obtained.
It is preferable that At this time, the dihydroxy compound [I
I] and the monohydroxy compound [III] preferably satisfies 0<[III]/[II]+[III]<2/3.

[0032] The polyester comprising the above-mentioned components can be produced using any of the generally known polycondensation methods listed below.

(2) A method of directly reacting a dicarboxylic acid with a diol component (including aliphatic diols, dihydroxy compounds, monohydroxy compounds, etc.).

(2) A method in which a lower ester of dicarboxylic acid and a diol component are reacted using transesterification.

(2) A method in which a dicarboxylic acid halide and a diol component are reacted in a suitable solvent such as pyridine.

(2) A method in which a metal alcoholate as a diol component is reacted with a dicarboxylic acid halide.

(2) A method of reacting an acetylated diol component with a dicarboxylic acid using transesterification.

[0038] In the polycondensation, catalysts generally used in producing polyester may be used. This catalyst includes metals such as lithium, sodium, potassium, cesium, magnesium, calcium, barium, strontium, zinc, aluminum, titanium, cobalt, germanium, tin, lead, antimony, arsenic, cerium, boron, cadmium, manganese, etc. Examples thereof include organometallic compounds, organic acid salts, metal alkoxides, and metal oxides.

Particularly preferred catalysts are calcium acetate, diacyltinn, tetraacyltinn, dibutyltin oxide, dibutyltin dilaurate, dimethyltin malate,
These are tin dioctanoate, tin tetraacetate, triisobutylaluminum, tetrabutyl titanate, germanium dioxide, and antimony trioxide. Two or more of these catalysts may be used in combination. Furthermore, in order to efficiently distill off water, alcohol, glycol, etc. that are by-produced during polymerization and obtain a high molecular weight polymer, it is preferable to reduce the pressure of the reaction system to 1 mmHg or less in the late stage of polymerization. The reaction temperature is generally 150-350°C.

[0040] Also, during polymerization, dihydroxy compound [II]
It is also possible to control the structure of the resulting polyester by changing the order of addition. For example, when dihydroxy compound [II] is charged together with dicarboxylic acid and other diol components, a random copolymer is easily obtained, and in the late stage of polymerization, dihydroxy compound [II]
It becomes easier to obtain a block copolymer when this is charged. Alternatively, the above-mentioned dihydroxy compound [II] or an acetyl compound of the dihydroxy compound is kneaded with a pre-synthesized polyester under reduced pressure and heat, and a segment based on the dihydroxy compound [II] is introduced into the molecular chain by deethylene glycol or transesterification reaction. is also possible.

The epoxy compound used in the present invention is not particularly limited in structure as long as it has three or more epoxy groups in the same molecule. Specific examples of epoxy compounds include trimethylolpropane triglycidyl ether, triglycidyl-p-aminophenol,
Triglycidyl isocyanurate, tetraglycidyl metaxylene diamine, tetraglycidyl-1,3-bisaminomethylcyclohexane, tetraglycidyldiaminodiphenylmethane and phenol having the following structure:
Glycidyl ethers are formaldehyde novolacs.

[0042]

[C6]

In the formula, R4 represents an alkyl group, and X is 1 to
Indicates an integer of 6.

The amount of the epoxy compound added varies depending on the capacity of the end groups of the polyester, but it is added at a rate of 0.05% to 5.00% by weight based on the polyester.

By adding the epoxy compound to the polyester in this manner, when kneaded or used at high temperatures, the epoxy compound reacts with the polyester to extend its molecular weight and/or the epoxy group is added to the polyester. It is thought that thermal stability (hydrolysis resistance) is improved by sealing the terminal carboxyl group. In other words, when an epoxy compound having three or more epoxy groups in one molecule is used, the terminal carboxyl groups of polyester are blocked, the catalytic decomposition promoting effect of the carboxyl groups is suppressed, and the two terminal carboxyl groups are blocked. It is presumed that this linkage suppresses the decrease in molecular weight.

[0046] Content of epoxy compound is 0.05% by weight
Below this, the above effects cannot be achieved. 5.00% by weight
If it exceeds , the mechanical strength etc. of the resulting polyester composition will decrease.

A catalyst may be added to promote the reaction between the above-mentioned epoxy compound and polyester.

The following additives may be further added to the polyester composition of the present invention within a range that does not impair its practicality. Namely, inorganic fibers such as glass fiber, carbon fiber, boron fiber, silicon carbide fiber, alumina fiber, amorphous fiber, silicon/titanium/carbon fiber; organic fiber such as aramid fiber; calcium carbonate, titanium oxide, mica, and talc. Inorganic fillers such as triphenyl phosphite, trilauryl phosphite, trisnonylphenyl phosphite, 2-tert-butyl-α-(3-
Heat stabilizers such as tert-butyl-4-hydroxyphenyl)-p-cumenylbis(p-nonylphenyl) phosphite, hexabromocyclododecane, tris-(2,
Flame retardants such as 3-dichloropropyl) phosphate, pentabromophenyl allyl ether, p-tert-butylphenyl salicylate, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-2
UV absorbers such as '-carboxybenzophenone and 2,4,5-trihydroxybutyrophenone, butylated hydroxyanisole, butylated hydroxytoluene, distearylthiodipropionate, dilaurylthiodipropionate, hindered phenolic antioxidants, etc. antistatic agents such as N,N-bis(hydroxyethyl)alkylamines, alkylarylsulfonates, and alkylsulfanates; inorganic substances such as barium sulfate, alumina, and silicon oxide; sodium stearate, barium stearate, Examples include higher fatty acid salts such as sodium palmitate; organic compounds such as benzyl alcohol and benzophenone; and crystallization promoters such as highly crystallized polyethylene terephthalate and polytrans-cyclohexanedimethanol terephthalate.

The method for producing the polyester composition of the present invention is not particularly limited, and polyester, epoxy compounds,
And, if necessary, after mixing a catalyst and the like, the mixture is melt-kneaded using a commonly known method. For example, an extruder,
There are melt-kneading methods using a Banbury mixer, rolls, kneaders, etc. The temperature during melt kneading is 150 to 280
A range of 0.degree. C. is preferred.

Furthermore, the polyester composition of the present invention:
It may be mixed with other thermoplastic resins such as polyolefins, modified polyolefins, polystyrene, polyamides, polycarbonates, polysulfones, polyesters, etc., or mixed with rubber components to modify its properties.

The polyester composition of the present invention is made into a molded article by press molding, extrusion molding, injection molding, blow molding or the like. The physical properties of the molded product can be arbitrarily changed depending on its constituent components, their blending ratios, and the like. When polyester is prepared as a thermoplastic resin elastomer, the molded product is suitably used for flexible molded products such as automobile parts, hoses, belts, gaskets, paints, adhesives, and the like.

[0052]

EXAMPLES The present invention will be explained below based on examples. In addition, the intrinsic viscosity and physical properties of the polyester compositions obtained in the following examples were measured according to the following methods.

[0053] Intrinsic viscosity [η]: Measured at 30°C in o-chlorophenol solvent using an Ubbelohde viscosity tube.

■Tensile strength at break and tensile elongation at break: JIS K-
6301, a No. 3 dumbbell test piece with a thickness of 2 mm was prepared. Using this, a test was conducted at a tensile speed of 50 mm/min.

Examples 1 to 4 and Comparative Example 1 [Synthesis of polyester] 292.5 g (2 mol) of adipic acid, 298 g (2.4 mol) of ethylene glycol and 4,4'
''-dihydroxy-p-quarterphenyl (hereinafter referred to as
To 67.7 g (0.02 mol) of monomer mixture (referred to as DHQ), 200 mg of germanium dioxide was added as a catalyst.
and 1,3,5-trimethyl-2,4,6 as a stabilizer.
- Tris(3,5-di-t-butyl-4hydroxybenzyl)benzene 400 mg, Tris(2,4-di-t-
400 mg of (butylphenyl) phosphite was added, and the reaction system was maintained at 200° C. for 2 hours under nitrogen to carry out an esterification reaction. Next, this reaction system was heated to 320°C for 30 minutes, maintained at normal pressure for 20 minutes, and then heated to 320°C for 30 minutes.
The polycondensation reaction was carried out for 2 hours while the temperature was lowered to 0° C. and the pressure was reduced to 1 mmHg or less, and as a result, a pale yellow resin was obtained. The intrinsic viscosity [η] of the obtained polyester was 1.10.

[Epoxy compound] The epoxy compound shown below was used.

A: Epolite 100MF manufactured by Kyoeisha Yushi Kagaku Kogyo Co., Ltd.

[0058]

[C7]

B: TETRAD-X, manufactured by Mitsubishi Gas Chemical Co., Ltd.

[0060]

[Chemical formula 8]

C: Sumiepoxy ESCN manufactured by Sumitomo Chemical Co., Ltd.
-220L

[0062]

[Chemical formula 9]

[Preparation of polyester composition and measurement of its physical properties] The above polyester and the epoxy compounds shown in Table 1 were added in the amounts shown in Table 1 and 0.5 weight of Irganox 1010 (phenolic stabilizer, manufactured by Ciba Geigy). The mixture was extruded at 240° C. using a Brabender Plastograph extruder, cooled with water, and then cut into pellets. The intrinsic viscosity of this pellet was measured. In addition,
Residence time in the extruder was 4 minutes.

Next, the obtained pellets were allowed to stay in the cylinder of a Koka-type flow tester (Flow Tester CFT-500 manufactured by Shimadzu Corporation) at 240°C for 30 minutes, and the intrinsic viscosity after the stay was measured. The results are shown in Table 1.

Examples 5 to 8 and Comparative Example 2 The pellets obtained in Examples 1 to 4 were molded into dumbbell test pieces by injection, and the test pieces were heated in a gear oven for 150 min.
The temperature was maintained at ℃. The tensile strength at break and tensile elongation at break of this test piece were measured, and the tensile strength retention rate and tensile elongation retention rate at break were calculated. The results are shown in Table 2.

Examples 9 to 12 and Comparative Example 3 Examples 1 to 4
The pellets obtained were molded into dumbbell test pieces by injection, and the test pieces were immersed in ion-exchanged water at 70°C for 7 days. The tensile strength at break and tensile elongation at break of this test piece were measured, and the tensile strength retention rate and tensile elongation retention rate at break were calculated. The results are shown in Table 3.

[0067]

[Table 1]

[0068]

[Table 2]

[0069]

[Table 3]

[0070]

According to the present invention, it is possible to provide a polyester composition in which deterioration caused by long-term heating during processing and deterioration caused by molded articles being used at high temperature and high humidity for a long time is reduced. The polyester composition obtained in this way has a segment based on a dihydroxy compound or monohydroxy compound with high crystallinity and a high melting point introduced into the aliphatic polyester mainly composed of an aliphatic dicarboxylic acid and an aliphatic diol. Since it contains polyester, it can be used for various parts as a thermoplastic elastomer with excellent heat resistance, mechanical properties, moldability, etc.

Claims (1)

[Claims] Claim 1: An aliphatic dicarboxylic acid whose general formula is represented by the following formula [I]; an aliphatic diol; and an aliphatic diol whose general formula is represented by the following formula [I]
Dihydroxy compound represented by I] and the following formula [III]
A polyester composition containing a polyester having at least one of the monohydroxy compounds represented by the following as a constituent component, and a trifunctional or higher functional epoxy compound, wherein the epoxy compound has a 0.0. Polyester composition containing 05% to 5.00% by weight: HOOC-(CH2)n-COOH [I](
In the formula, n represents an integer of 0 to 10. ) [Formula, R1 and R2 independently represent an alkylene group, p is 3 or 4, and q and r are independently 0 or 1
Indicates an integer greater than or equal to ) [In the formula, R3 represents an alkylene group, l is 2 or 3, and m represents an integer of 0 or 1 or more.