JPH03275715A - Copolymer polyester resin - Google Patents

Abstract

PURPOSE:To obtain the title resin useful as plastic, etc., having excellent balance of heat resistance and mechanical properties, improved strength at welded part, by copolymerizing compounds selected from specific ester-forming reactive group-containing aromatic compounds. CONSTITUTION:The objective resin which is obtained by copolymerizing at least one structural unit comprising structural units shown by formula I to formula IV (R1 is group shown by formula V, formula VI, etc. ; R2 is group shown by formula V, formula VII, etc.) and obtained from polyfunctional compounds having structural units shown by formula VIII and formula IX (X1 to X7 are each independently polyester-forming -O- or group shown by formula X; Ar1 is trisubstituted aromatic residue; Ar2 is tetrasubstituted aromatic residue) and has 0.01-5 mol% structural units shown by formulas (VIII+ IX) based on structural units shown by formulas (I+II+III+IV) and 0.5-15 dl logarithmic viscosity.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention provides a polymer with a high degree of polymerization obtained only by melt polymerization, exhibits melt liquid crystallinity, and has excellent mechanical properties that can be molded with an ordinary molding machine. The present invention relates to a copolyester having high weld strength.

<Conventional technology> In recent years, the demand for higher performance plastics has been increasing, and many polymers with various new performances have been developed.Among them, optically anisotropic liquid crystal polymers have excellent mechanical properties. (Japanese Unexamined Patent Publication No. 51-83)
9.5, JP-A-49-72393).

As the above-mentioned liquid crystal polymer, for example, a liquid crystal polymer obtained by copolymerizing polyethylene terephthalate with p-hydroxybenzoic acid is known (Japanese Patent Application Laid-Open No. 72393/1983). However, injection molded products made of this polymer have drawbacks such as insufficient heat resistance and poor mechanical properties, and it has been found that injection molded products satisfying both properties cannot be obtained from this polymer. Furthermore, it has been found that in order to improve heat resistance, the amount of p-hydroxybenzoic acid must be 80 mol % or more, but solidification occurs during polymerization and solid phase polymerization is necessary.

On the other hand, as a means to improve the fluidity of such polymers, improve melt moldability, and further improve mechanical properties, for example, as described in Japanese Patent Application Laid-Open No. 51-8395, polyethylene A method has been proposed in which terephthalate is copolymerized with ρ-acyloxybenzoic acid, dicarboxylic acid, and aromatic diol, but although this method also improves the mechanical properties of the injection molded products obtained, the heat resistance is insufficient. I understand. On the other hand, the special public official
As described in Japanese Patent No. 7870, an injection molded product made of a wholly aromatic polyester made by copolymerizing p-hydroxybenzoic acid with 4.4'-dihydroxybiphenyl and terephthalic acid has good heat resistance, but has a low softening temperature. It was found that melt polymerization was difficult because the temperature was 400°C or higher, and the mechanical properties were not fully satisfactory.

Furthermore, as a method to solve these problems,
The polymer described in Publication No. 3-30523, which is made by copolymerizing polyethylene terephthalate with ρ-human'Oxybenzoic acid, a specific aromatic dihydroxy compound, and an aromatic dicarboxylic acid, has a satisfactory balance of mechanical properties and heat resistance. However, it was found that problems remained, such as the mechanical properties of the molded product, particularly the strength of the weld part, which was somewhat low.

<Problems to be Solved by the Invention> The present invention solves the above-mentioned problems and provides a copolymerized polyester that can provide a molded product with an excellent balance of mechanical properties and heat resistance, and particularly improved strength in the weld area. The challenge is to obtain resin.

<Means for Solving the Problems> Therefore, the present inventors made extensive studies to achieve the above object, and found that p-hydroxybenzoic acid, 4゜4-dihydroxybiphenyl, specific aromatic dihydroxy compounds, aromatic A copolymerized polyester obtained by reacting a polyester produced from a dicarboxylic acid or ethylene glycol with an aromatic dicarboxylic acid, and at least one compound selected from aromatic compounds having a trifunctional or tetrafunctional ester-forming reactive group. The present invention has been achieved by discovering that the above object can be achieved by copolymerizing.

That is, the present invention provides the following structural units (I), (n), (I
II) and (IV), and further copolymerized with at least one kind of structural unit obtained from a polyfunctional compound shown in the following structural units (V) and (VI), and the structural unit [(V) + (VH] is the structural unit [(I) + (IF
) + (III) + (V) + (VI)] 00.
occupies 01 to 5 moles and has a logarithmic viscosity of 0.5 to 15 dI/g
The present invention relates to a copolymerized polyester resin characterized by the following.

1+O-R□-O+ 1+C0-R2-C0+- ...(III) ...〈1v〉 Indicates one or more groups selected from -CH2CH2-.

Here, Y represents a chlorine atom or a hydrogen atom. Further A
r1 represents a 3-substituted aromatic residue, and Ar2 represents a 4-substituted aromatic residue. In addition, Xl, x2, x, , x4, xS, x, and X7 are each independently polyester-forming -O-
or -C-. 〉 The method of reacting a polyfunctional compound having three or more reactive functional groups with liquid crystalline polyester is disclosed in Japanese Patent Application Laid-Open No. 62-70419.
However, the purpose of this is to crosslink and fix the liquid crystal polyester by adding a large amount of a polyfunctional compound to the liquid crystal polyester and reacting it. This is completely different from the present invention, in which a functional compound is added during polymerization to improve the weld strength without impairing the fluidity of the liquid crystal polyester.

The above structural unit (I) is a structural unit of polyester produced from (A>p-hydroxybenzoic acid), and the structural unit (
II) is a structural unit produced from (B) 4.4"-dihydroxybiphenyl, and structural unit (1) is a structural unit produced from hydroquinone, 2.6-dihydroxynaphthalene, 4.4°-dihydroxydiphenyl ether, 7-butylhydroquinone, phenyl A structural unit produced from one or more dihydroxy compounds selected from hydroquinone, 3.1,5°5-tetramethyl-4,4-monodihydroxybiphenyl, and ethylene glycol can also be used as structural unit (IV).
are terephthalic acid, isophthalic acid, 4.4-monodiphenyldicarboxylic acid, 2.6-naphthalenedicarboxylic acid, 1.
2-bis<phenoxy>ethane-4゜4-monodicarboxylic acid, 1,2-bis(2-chlorophenoxy>ethane-4
, 4°-dicarboxylic acid, and 4.4-mono-diphenyl ether dicarboxylic acid.

is particularly preferred.

Further, the structural unit (V) is a structural unit generated from an aromatic compound having a trifunctional polyester-forming reactive group, Ar represents a trisubstituted aromatic residue, trisubstituted benzene, trisubstituted naphthalene, Examples include 3-substituted biphenyl.

Examples of the polyester-forming reactive group of the compound constituting the structural unit (V) include hydroxyl group, acetoxy group, carboxyl group, carboxyphenyl group, etc. Compounds in which two adjacent carboxyl groups form an acid anhydride can also be preferably used.

Preferred specific examples of the compound having a trifunctional polyester-forming reactive group constituting the structural unit (V) include trimellitic acid, trimesic acid, hemimellitic acid, trimellitic anhydride, hemimellitic anhydride, -Hydroxyisophthalic acid, 2.3-dihydroxybenzoic acid, 2.4
-Dihydroxyamma, folic acid, 2.5-dihydroxybenzoic acid, 2.6-dihydroxybenzoic acid, 1°2.4-benzenetriol, 1.4-dihydroxy-2-naphthoic acid, 3.5-dihydroxy- 2-naphthoic acid, 3.7
-dihydroxy-2-naphthoic acid and its ester derivatives.

In addition, the structural unit (VI) is a structural unit generated from an aromatic compound having a tetrafunctional polyester-forming reactive group, and Ar2 represents a tetrasubstituted aromatic residue, such as tetrasubstituted benzene, tetrasubstituted naphthalene, Examples include 4-substituted biphenyl.

The polyester-forming reactive group of the compound providing the structural unit (VI> is the same as that for the structural unit (V),
Preferred specific examples of the compound providing the structural unit (VI) include pyromellitic acid, 1.4,5°8-naphthalenetetracarboxylic acid, 3.4.3-. Examples include 4-biphenyltetracarboxylic acid and its acid anhydrides and ester derivatives.

On the other hand, among the above structural units, the structural unit [<V>+(VI
)] is the structural unit [(I>+(II)+(III)+
It is necessary that the copolymerization amount is 0.01 to 5 mol % based on (V) + (VI). Structural unit [(
V) ten (VI) ] is the structural unit [(I) + (II
) + (III) + (V) + (VI) ] If it is less than 0°01 mol%, the effect of the present invention is not significant and the weld strength is not sufficiently improved. Also,
If it is more than 5 mol %, melt fluidity tends to decrease, which is not preferable in any case.

Further, in the structural unit (III), R1 is CH2C
In the case of H2-, the structural unit [(1)+(n)] is [(
II+(II>+(III))] is preferably 75 to 95 mol%, more preferably 82 to 93 mol%, and 85 to 9
Particularly preferred is 0 mol%.

Also, the structural unit (nl) is [(I>+<II)+(■>
] is preferably 25 to 5 mol%, more preferably 18 to 7 mol%, particularly preferably 15 to 10 mol%.

In addition, the molar ratio of structural units (I)/(II) is 75/25
-9515 is preferable, and 78/22 - 93/7 is more preferable.

Moreover, R1 of the structural unit (III) is -CH.

In cases other than CH2-, the structural unit (I> is [(I)
+(I[)+(III)] is preferably 440 to 90 mol, more preferably 60 to 88 mol%, particularly preferably 70 to 85 mol%.

Furthermore, the molar ratio of the structural units (n)/(III) is 1
/9 to 9/1 is preferable, more preferably 7.5/2°
5 to 2.5/7.5, particularly preferably 7.5/2.5 to
It is 4/6.

In addition, the structural unit [(II) + (III)] and the structural unit (
IV) is preferably substantially equimolar; however, in the present invention, since an aromatic compound having a trifunctional or tetrafunctional ester-forming reactive group is copolymerized, the composition ratio of IV) is as shown in the following formula. You may do so.

. , <[(II) +(III) 1<t, , (IV) The method for producing the copolyester resin of the present invention is not particularly limited, and it can be produced according to known polyester polycondensation methods.

For example, in the presence of a polyester or oligomer consisting of an aromatic dicarboxylic acid such as terephthalic acid and ethylene glycol or a bis(β-hydroxyethyl) ester of an aromatic dicarboxylic acid, p-hydroxybenzoic acid, 4,4-monodihydroxybiphenyl, etc. Aromatic hydroxyl compounds, aromatic dicarboxylic acids such as terephthalic acid, and compounds having trifunctional or tetrafunctional polyester-forming reactive groups such as trimellitic anhydride are treated with acetic anhydride to acetylate the hydroxyl groups, and then decomposed. A particularly preferred example is a method of producing by acetic acid polycondensation reaction.

Catalysts can also be used for the polycondensation reaction, such as stannous acetate,
Examples include metal compounds such as tetrabutyl titanate, potassium acetate, antimony trioxide, magnesium, and sodium acetate.

Furthermore, the melt viscosity of the copolymerized polyester resin of the present invention is lO
~15,000 boiz is preferred, especially 20-5.00
0 voice is more preferable.

Note that this melt viscosity is a value measured using a Koka type flow tester at a temperature of +40° C. to the liquid crystal start temperature and a slip rate of 1,000 (1/sec).

On the other hand, the logarithmic viscosity of the copolymerized polyester resin of the present invention is 0.
．． The value measured in pentafluorophenol at a concentration of 1 g/clQ and 60°C is 0.5 to L'5d'J/g. In addition, -CH2CH as Ro in the structural unit (I[[)
When containing 2-, it is 1.0 to 3. Odj! /g is preferred.

In addition, when polycondensing the copolymerized polyester resin of the present invention, 3.3'-diphenyldicarboxylic acid and 2.2-diphenyldicarboxylic acid are used in addition to the components constituting the above structural units (I) to (1v). Aromatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid, aliphatic dicarboxylic acids such as dodecanedioic acid, alicyclic dicarboxylic acids such as hexahydroterephthalic acid, aromatic dihydroxy compounds such as chlorohydroquinone and methylhydroquinone, 1
．． 4-butanediol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanediol, ■.

Aliphatic and alicyclic diols such as 4-cyclohexane dimetatool, aromatic hydroxycarboxylic acids such as m-hydroxybenzoic acid and 2,6-hydroxynaphthoic acid, and polyesters having imide bonds in the molecule. Aromatic imidodicarboxylic acids, aromatic imidodihydroxy compounds, aromatic imidohydroxycarboxylic acids, etc. which can be used may be further copolymerized within a small proportion that does not impair the object of the present invention.

The copolymerized polyester resin of the present invention thus obtained can be obtained by only melt polymerization, and has good melt fluidity and
It exhibits excellent mechanical properties and heat resistance with improved weld strength, and can be subjected to conventional melt molding such as extrusion molding, injection molding, compression molding, and blow molding, and can be used for fibers, films, three-dimensional molded products, containers, It is possible to process it into hoses, etc.

In addition, for the copolymerized polyester resin of the present invention, reinforcing agents such as glass fibers, carbon fibers, and asbestos, fillers, lubricants, mold release agents, nucleating agents, plasticizers, flame retardants, heat stabilizers, ultraviolet absorbers, and pigments. , dyes, other thermoplastic resins, etc. can be added as necessary to impart desired properties.

Although any means can be used to blend fillers, additives, reinforcing agents, etc. into the copolymerized polyester resin of the present invention, for example, a screw extruder can be preferably used.

In addition, the injection molded product obtained in this way can have its strength increased by heat treatment, and may also have its elastic modulus increased.

This heat treatment can be carried out by heat treating the injection molded article in an inert atmosphere (eg nitrogen, argon, helium or water vapor) or in an oxygen-containing atmosphere (eg air) at a temperature below the melting point of the polymer. This heat treatment may or may not be under tension, and can be carried out for a period of several tens of minutes to several days.

<Example> The present invention will be further explained below with reference to Examples.

Example 1 994 g (7-2 mol) of p-hydroxybenzoic acid, 134 g (0.72 mol) of 4゜4゛-dihydroxybiphenyl, and 1112 g (0,675 mol) of terephthal P were placed in a reaction vessel equipped with a stirrer and a distillation tube. 〉, acetic anhydride 970g
(9.5 mol), 216 g (1,125 mol) of polyethylene terephthalate with an intrinsic viscosity of 0.6, and 8.64 g (0,045 mol) of trimellitic anhydride were charged, and acetic acid depolymerization was carried out under the following conditions. Ta.

First, under a nitrogen gas atmosphere at 100 to 250°C for 5 hours,
After reacting at 50 to 320°C for 1.5 hours, 320°C,
The pressure was reduced to 0.5 mmH (l) in 1 hour, and the reaction was further carried out for 1.0 hour to complete the polycondensation, whereupon a nearly theoretical amount of acetic acid flowed out, and a polymer having the following theoretical structural formula was obtained.

+0CH2CH20→-/ to/N /m/n10=80/8/12.5/2010
．． 5 Also, place this polyester on the sample stage of a polarizing microscope,
As a result of confirming the optical anisotropy by raising the temperature, the liquid crystal start temperature was 283°C, indicating good optical anisotropy.

The obtained polymer was subjected to a Sumitomo Nestal injection molding machine Promat 40/25 (manufactured by Sumitomo Heavy Industries, Ltd.) to form a 1/8"
×1/2″×5″ test piece and ASTM NQ4
Molded dumbbells. ASTM No. 4 dumbbell is a normal mold with a gate at one end of the dumbbell (dumbbell ■)
and a weld mold (dumbbell ■) with gates on both ends of the dumbbell.And ASTM D
According to the 648 standard, the load deflection temperature [HDT] of 1/8-thick test piece (18,6hg f/cA)
was measured. In addition, according to ASTM D638 standard,
A STM No. 4 The breaking strength of the dumbbell was measured, and the ratio of the breaking strength of the dumbbell ■ to that of the dumbbell ■ was taken as the weld strength retention rate.

As a result, the HDT was 226°C, the strength of the dumbbell ■ (non-welded) was 1120 kgf/ca, the strength of the dumbbell ■ (welded) was 195 kgf/W, and the weld strength retention rate was 17.4%.

The logarithmic viscosity (in pentafluorophenol, 60°C) of this polymer was 1.92 dll/g, and the melt viscosity was 900 voids at a shear rate of 1,000 (1/sec), indicating extremely good fluidity. Ta.

Example 2 In a reactor similar to Example 1, p-hydroxybenzoic acid 9 was added.
94 g (7,2 mol), 231 g (1,24 mol) of 4.4″ dihydroxybiphenyl, 147 g (0,60 mol) of 2,6-diacedoxynaphthalene, 299 g (1,8 mol) of terephthalic acid and Acid anhydride a 1087g (
10,64 mol) and trimellitic anhydride 8°64
g (0,045 mol) and set the final polymerization temperature to 34
Polymerization was carried out under the same conditions as in Example 2, except that the temperature was 0°C.

As a result, a polymer having the following theoretical structural formula was obtained.

k/fJ/m/n10=80/13.8/6.7/2
010.5 Also, place this polyester on the sample stage of a polarizing microscope,
As a result of confirming the optical anisotropy by increasing the temperature, the liquid crystal initiation temperature was 296° C., indicating good optical anisotropy.

The obtained polymer was subjected to a Sumitomo Nestal injection molding machine Promat 40/25 (manufactured by Sumitomo Heavy Industries, Ltd.) under the conditions of a cylinder temperature of 320°C and a mold temperature of 90°C to 1/8"
Xi/2″×5~ test piece and ASTM Nα4
Molded dumbbells. ASTM NQ4 dumbbells were molded using both a regular mold (dumbbell ■) with a gate at one end of the dumbbell and a weld mold (dumbbell ■) with gates at both ends of the dumbbell. and ASTM D6
The load deflection temperature [HDT] (18,6 kgf/cn) of a 1/8" thick test piece was measured according to the ASTM D638 standard.
The breaking strength of STM No. 4 dumbbells was measured, and the ratio of the breaking strength of dumbbell ■ to dumbbell ■ was taken as the weld strength retention rate.

As a result, the strength of the dumbbell ■ (non-welded > 1320 kgf /cA) was HDT 262°C, the strength of the dumbbell ■ (welded > 220 kgf /cA, and the weld strength retention rate was 16.7%, which was good as in Example ■). Met.

The logarithmic viscosity (in pentafluorophenol, 60°C) of this polymer is 5.21 dU/g, and the melt viscosity is 336.
℃ and a shear rate of 1,000 (1/sec), the fluidity was 580 poise, which was extremely good.

Comparative Example 1 An experiment similar to Example 2 was conducted on a polymer having a composition that does not contain the structural units (V), (VI), and (VI) of the present invention.

In a reaction vessel similar to Example 1, 994% p-hydroxybenzoic acid was added. g (7,2 mol), 4,4-dihydroxybiphenyl 126 g (0,675 mol), acetic anhydride 960 g
(9,4 mol>, terephthalic acid 112 g (0,67
5 moles) and 216 g (1,1,25 moles) of polyethylene terephthalate having an intrinsic viscosity of 0.6 were charged, and acetic acid removal polymerization was carried out under the same conditions as in Example I to obtain a polymer having the following theoretical structural formula.

+0CH2CH20→-/ ni/, 1)/m/n=80/7.5/12.5/20 Also, place this polyester on the sample stage of a polarizing microscope,
As a result of confirming the optical anisotropy by increasing the temperature, the liquid crystal initiation temperature was 294°C.

This polymer was molded in the same manner as in Example 1, and HD
As a result of measuring T and breaking strength, HD7231℃, dumbbell strength (non-welded) 1200kgf /c
a. Strength of dumbbell ■ (weld > 150 kgf/ca
It was found that the weld strength retention rate was 12.5%, which was lower than in the example.

<Effects of the Invention> The copolymerized polyester of the present invention can be obtained using only a melt polymerization method to obtain a polymer with a high degree of polymerization. Since improved molded products can be obtained, they can be used in various applications such as plastic substitutes for metals.

Claims (1)

[Claims] Consisting of the following structural units (I), (II), (III) and (IV), and further comprising a polyfunctional compound obtained from the following structural units (V) and (VI). Both are made by copolymerizing one type of structural unit, and the structural unit [(V) + (VI)] is 0.0% of the structural unit [(I) + (II) + (III) + (V) + (VI)]. occupies 01 to 5 mol% and has a logarithmic viscosity of 0.5 to 15 d
1/g. ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(III) ▲Mathematical formulas , chemical formulas, tables, etc. ▼...(IV) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼...(V) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼...(VI) (However, (III ) R_1 in the formula is ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲Mathematical formulas, chemical formulas,
There are tables, etc. ▼ ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Mathematical formulas, chemical formulas,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ and -CH_2CH_2- Indicates one or more groups selected from. Also, R_2 in formula (IV) is ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲Mathematical formulas, chemical formulas, tables, etc. Indicates one or more groups selected from ▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼ and ▲There are mathematical formulas, chemical formulas, tables, etc.▼. Here, Y represents a chlorine atom or a hydrogen atom,
Further, Ar_1 represents a 3-substituted aromatic residue, and Ar_2 represents a 4-substituted aromatic residue. Also, X_1, X_2, X_3,
_4, X_5, X_6 and X_7 each independently represent polyester-forming -O- or ▲There are numerical formulas, chemical formulas, tables, etc.▼. )