JPS63280731A - Aromatic polyester having excellent fluidity - Google Patents

Abstract

PURPOSE:To obtain the titled melt-moldable polyester having excellent fluidity, heat-resistance and mechanical properties and suitable as engineering plastics, etc., by copolymerizing a disubstituted hydroquinone to an aromatic polyester at a specific ratio. CONSTITUTION:The objective polyester having a logarithmic viscosity of 0.1-20.0dl/g can be produced by (1) mixing (A) p-hydroxybenzoic acid forming the constituent unit of formula I, (B) (i) terephthalic acid and/or isophthalic acid and (ii) an aromatic dihydroxy compound such as 4,4'-dihydroxybiphenyl forming the constituent unit of formula II (X is group of formula III, etc.) and (C) a disubstituted hydroquinone [e.g. 2,5-di(t-butyl)hydroquinone] forming the constituent unit of formula IV (Y is group of formula V, etc.) and (2) subjecting the mixture e.g. to deacetylation polycondensation reaction. The ratio of the unit of formula I and that of formula II+III in the mixture are 40-90mol.% and 60-10mol.%, respectively, and the molar ratio of the unit of formula II/ formula III is 9/1-1/9.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to an aromatic polyester that can be melt-molded at 400'C or less and can provide molded products having excellent fluidity, heat resistance, and mechanical properties. It is.

<Conventional technology> In recent years, the demand for higher performance plastics has been increasing, and many polymers with various new performances have been developed and put on the market. Optically anisotropic liquid crystal polymers have attracted attention because of their excellent mechanical properties.

Fully aromatic polyesters are widely known as liquid crystal polymers, such as homopolymers of hydroxybenzoic acid and copolymers of 4,4'-dihydroxybiphenyl and phthalic acid.

However, the melting points of these hydroxybenzoic acid pomobolymers and copolymers are often too high and their melt flow properties are insufficient. For this reason, methods of copolymerizing p-hydroxybenzoic acid with various components to lower its melting point have been investigated.
- A method of copolymerizing naphthalene dicarboxylic acid (Publication Patent Publication No. 55-500215), a method of copolymerizing p-hydroxybenzoic acid with 2,6-hydroxynaphthalene and terephthalic acid (Japanese Unexamined Patent Publication No. 54-50594) and a method of copolymerizing hydroxybenzoic acid with 2,6-hydroxyanthraquinone and terephthalic acid (U.S. Patent No. 4
．． 224.433), 4. to p-hydroxybenzoic acid.
A method of copolymerizing 4°-dihydroxybiphenyl, terephthalic acid, and isophthalic acid (Japanese Patent Publication No. 57-24407, Japanese Patent Publication No. 60-25046), a method of copolymerizing phenylhydroquinone and terephthalic acid with hydroxybenzoic acid ( U.S. Pat. No. 4,242,496), No. 3
A method of copolymerizing hydroxybenzoic acid with terephthalic acid and a nuclear-transformed hydroquinone containing an alkyl group or an aralkyl group (JP-A-58-29819, JP-A-58-45224, JP-A-59-1999) 78232] etc. have been proposed.

<Problems to be solved by the invention> However, many of the aromatic polyesters obtained by these methods have comparatively low melting points of 400°C or less;
Since the fluidity is insufficient or the heat resistance is insufficient, there is a desire for better fluidity and higher heat resistance.

Among these, polyester consisting of p-oxybenzoic acid, 2,6-hydroxynaphthalene, and terephthalic acid (Japanese Patent Laid-Open No. 54-50594) has good fluidity, but on the other hand, it Deformation temperature is low,
It was found that the heat resistance was insufficient, and that 2,6-cyoxynaphthalene or its derivatives were extremely prone to sublimation during polymerization, making it impossible to obtain a polymer with a uniform composition.

On the other hand, polyesters composed of p-oxybenzoic acid, 4,4'-dihydroxybiphenyl, terephthalic acid, and isophthalic acid have comparatively good heat resistance, but on the other hand, they have poor fluidity during polymerization. It is known that it has the disadvantage that it is difficult to polymerize only by melt polymerization.

Furthermore, it has been found that polyesters composed of t-amylhydroquinone, methylbenzylhydroquinone, etc., terephthalic acid, and oxybenzoic acid have insufficient fluidity, heat resistance, mechanical properties, and the like.

Therefore, the object of the present invention is to obtain an aromatic polyester having good fluidity without impairing heat resistance.

Means for Solving the Problems〉 The present inventors have made the results of intensive studies to achieve the above object.
hydroxybenzoic acid, one or more aromatic dihydroxy compounds selected from 4.4'-dihydroxybiphenyl, t-butylhydroquinone, phenylhydroquinone, 2,6-cyoxynaphthalene, and hydroquinone, and terephthalic acid and/or isophthalic acid. The present invention has been completed based on the discovery that an aromatic polyester that satisfies the above objectives can be obtained by copolymerizing a specific aromatic dihydroxy compound with a polyester made of an acid.

That is, the present invention consists of the following structure at position 9 (I) to (III), where the structural unit (I) is 40 to 90 mol% of the total, and the unit [(II) + (1)] is 60 to 10 mol% of the total. %, the molar ratio of structural units (II)/(III) is 971 to 1/9, and the logarithmic viscosity is 1 when dissolved in pentafluorophenol at 60°C at a concentration of 0.1 g/dl. The present invention provides an aromatic polyester having good fluidity, characterized by a dρ/g of .0 to 20.0 dρ/g.

+0+CO+-・・・・・・(I) CIl.

The carbonyl groups of the fl structural unit (I[> and (1)) are in a distal or meta position relationship with each other, and 65 mol% of the
The above is the para level. > In the aromatic polyester of the present invention, position 0 (1) in the above structure is a structural unit of the polyester produced from p-hydroxybenzoic acid.

The above tM structural unit II) is one or more selected from 4,4°-dihydroxybiphenyl, (-butylhydroquinone, phenylhydroquinone, 2,6-cyoxynaphthalene, and hydroquinone), preferably 4゜4゛-dihydroxybiphenyl or 4,4°-dihydroxybiphenyl and hydroquinone) and terephthalic acid and/or isophthalic acid.

The above structural unit (III) is 2,5-di([-butyl)hydroquinone, 2,5-di(isopropyl)hydroquinone, 2,5-di(isoamyl>hydroquinone, 2゜5-di(cyclohexyl)hydroquinone, 2 , 5-bis(dimethylbenzyl)hydroquinone, 2,5-diphenylhydroquinone, preferably 2,5-di([-
butyl) hydroquinone, 2,5-di(t-amyl)hydroquinone, 2,5-di(cyclohexyl)hydroquinone, and 2,5-diphenylhydroquinone, particularly preferably 2,5-di(t-amyl)hydroquinone, and 2,5-di(t-amyl)hydroquinone. -Butyl> Indicates the structural unit of polynisder produced from hydroquinone and terephthalic acid and/or isophthalic acid.

Of the terephthalic acid and/or isophthalic acid constituting the structural units <ff) and (II[), it is essential that terephthalic acid accounts for 65 mol% or more, and it is particularly preferable that terephthalic acid accounts for 100 mol%.

The above structural unit (I> is 40 to 90 mol% of the total, and the structural unit r(I[)+(I[I)] is 60 to 10 mol% of the total
It is essential that the structural unit <I) is 90% of the total
If it exceeds mol % or is less than 40 mol %, the fluidity will be insufficient and it is not practical.

Moreover, the molar ratio of structural unit (II)/(I) is 971 to
17, preferably 872-515.

When the vJ structural unit II)/(III) value exceeds 9/l or is less than 179, the fluidity or heat resistance is insufficient and it is not practical.

The aromatic polyester of the present invention can be produced according to conventional polyester polycondensation methods, and there are no particular restrictions on the production method, but typical production methods include the following (]) to (4).
) law.

(1) Produced by deacetic acid polycondensation reaction from acylated oxycarboxylic acids such as acetoxybenzoic acid, acylated aromatic hydroxy compounds such as 4,4'-diacetoxybiphenyl, and aromatic dicarboxylic acids such as terephthalic acid. how to.

(2) A method for producing by deacetic acid polycondensation reaction from an aromatic dihydroxy compound such as oxybenzoic acid or 4,4'-dihydroxybiphenyl, an aromatic dicarboxylic acid such as terephthalic acid, and acetic anhydride.

(3) phenyl ester of oxybenzoic acid and 4.
A method for producing by dephenol polycondensation from an aromatic dihydroxy compound such as 4'-dihydroxybiphenyl and a diphenyl ester of an aromatic dicarboxylic acid such as terephthalic acid.

(4) Aromatic dicarboxylic acids such as p-oxybenzoic acid and terephthalic acid are reacted with a specified amount of diphenyl carbonate to form diphenyl esters, respectively.
, 4'-dihydroxybiphenyl and other aromatic dihydroxy compounds are added thereto, followed by a phenol-depleting polycondensation reaction.

In addition, in the methods (1) to (4), 2
．． When introducing a 6-hydroxynaphthalene residue, 2
, 6-diacedoxynaphthalene is preferred.

Typical catalysts used in the polycondensation reaction are metal compounds such as stannous acetate, tetrabutyl titanate, lead acetate, antimony dioxide, magnesium, sodium acetate, potassium acetate, and trisodium phosphate, with potassium acetate being particularly effective. De-ru.

Further, the melt viscosity of the aromatic polyester of the present invention is 50 to
15,000 voices are preferred, especially 100 to io.

00 voids is more preferred.

The melt viscosity is a value measured using a Koka type flow tester at a liquid crystal start temperature +40'C) and a slip rate of 3,000 (1/paper).

The logarithmic viscosity of these aromatic polyesters is 0.1 g/d in pentafluorophenol at 60°C, and when dissolved at a concentration of Q, the logarithmic viscosity is 1.0 to 20.0 dll/g.
and 1.0 to 10. Odoll/g is preferred;
Particularly preferred is 2.0 to 6,0017 g.

In addition, when polycondensing the aromatic polyester of the present invention, in addition to the components constituting the above (1) to (III), 4.4°
-diphenyldicarboxylic acid, 2,2°-diphenyldicarboxylic acid, 1,2-bis(phenoxy)ethane-4,4
°-Dicarboxylic acid, aromatic dicarboxylic acids such as 1,2-bis(2-chlorophenoxy)ethane-4,4-dicarboxylic acid, alicyclic dicarboxylic acids such as hexahydroterephthalic acid, bisphenol A5, bisphenol S, resorcinol , 4.4°-Aromatic dihydroxy compounds such as dihydroxydiphenyl sulfide, m-oxybenzoic acid, 2.6
- Aromatic oxycarboxylic acids such as oxynaphthoic acid, aminophenol, p-aminobenzoic acid, etc. can be further copolymerized within a small proportion that does not impair the object of the present invention.

The aromatic polyester of the present invention thus formed has a melting point of 40
It has a low temperature of 0'C and can be used in ordinary melt molding such as extrusion molding, injection molding, compression molding, and blow molding, and can be processed into fibers, films, three-dimensional molded products, containers, hoses, etc. .

In addition, during molding, for the aromatic polyester of the present invention,
Additives such as glass fibers, carbon fibers, asbestos, fillers, nucleating agents, pigments, antioxidants, stabilizers, plasticizers, lubricants, mold release agents, flame retardants, and other thermoplastic resins. By doing so, desired characteristics can be imparted to the molded product.

The strength of the thus obtained molded product can be increased by heat treatment, and the elastic modulus can also be increased in many cases.

This heat treatment can be carried out by heat treating the molded article at a temperature below the melting point of the polymer in an inert atmosphere (for example nitrogen, argon helium or water vapor) or in an oxygen-containing atmosphere (for example air) or under reduced pressure.

This heat treatment may or may not be under tension and can be carried out for several tens of minutes to several days.

The molded article obtained from the aromatic compound of the present invention has good optical anisotropy and heat resistance due to its parallel molecular arrangement, and has extremely excellent mechanical properties and fluidity.

<Example> The present invention will be explained in more detail with reference to Examples below.

Example 1 P-acetoxybenzoic acid (I) 51°8 in a test tube for polymerization
9g (28,8X12-2 mol), 21.62g (8,0
X10-2 mol), 2,5-di(dobutyl)hydroquinone diacetate (III) 9,81 g (3,2X
10-2 mol) and terephthalic acid (■) 18.61
g (11,2X10-2 mol) (I)/[(I)
+(II)] was 72 mol% and the molar ratio of (n)/(I) was 7.14/2.86, and acetic acid depolymerization was carried out under the following conditions. First, under a nitrogen gas atmosphere,
After reacting at ~340°C for 3.0 hours, the temperature was raised to 350'C, the pressure was reduced to 0.5 mmIl(], and the mixture was further heated for 1.0 hours to perform a polycondensation reaction and obtain a brown polymer. Na.

The theoretical structural formula of this polymer is as follows, and the elemental analysis results are shown in Table 1, showing good agreement with the theoretical values.

1+o-Q-co+,, ”(xnOC÷CO glaze ρ/m
/n=72/20/8 Table 1 However, it was calculated from O (%) = 100 (%) - C (%) - H (%).

We also confirmed the optical anisotropy by placing this polymer on the sample stage of a polarizing microscope and increasing the temperature and applying abrasion stress.
It showed good optical anisotropy at 293°C or higher.

The melt viscosity of this polymer is 333°C1 shear rate 3
,000 (1/sec) and 870 voids, indicating extremely good fluidity. The logarithmic viscosity of this polymer is 2.7 (!Q/g
Met.

This polyester was further polymerized in 5 batches under the same conditions, and the polymer was pulverized using a crusher manufactured by Seishi Co., Ltd., and then applied to a Susumu Nestal injection molding machine Promat 40/25 (manufactured by Susumu Heavy Industries Co., Ltd.). Under the conditions of temperature 360°C and mold temperature 30°C, 178″ thickness Xi / 2° width x 5°”
A long test piece and a 1/8" thick x 2 1/2' long mold notch test piece were prepared. This test piece was heated using a tension test piece made by Toyo Baldwin Co., Ltd., UTH-10.
Use 0, hissing speed 1nwn/min, distance between spans 5
When the bending elastic modulus was measured under the condition of 0 mm, it was 12 GPa.
Met. Izotsu impact value (mold notch) is 1.
It showed a high value of 25 kg-an/an.

In addition, the heat deformation temperature of a 1/8" thick test piece was measured at 234°C (18,
It had excellent heat resistance (56 kg/ci).

Example 2 P-acetoxybenzoic acid (1) 51, 8 in a test tube for polymerization
9 g (28,8X10-2 mol), 18.38 g (6,8X10
-2 mol), hydroquinone diacetate (In)
1.94g<1.0X10-2 mol), 2.5-di(dobutyl)hydroquinone diacetate (IV>
10.42 g <3.4X10-2 mol) and 18.61 g of terephthalic acid (V) (11,2X10-2
mole) to (■)/[(II)-(II[)+(IV)]
was prepared so that the molar ratio of [(■)t(■)1/(Iv) was 12 mol% and 6.96/3.04, and polymerization was carried out under the same polymerization conditions as in Example 1 to obtain a brown polymer. Obtained. The theoretical structural formula of this polymer is as follows, and the elemental analysis results show good agreement with the theoretical values as shown in Table 2.

-<0-Q-to CO/n%0. c@-COi/+0+0
2C-o-CO Hanawa C1]3 /, Q, /m/ n=72/17/2.5 /8.
5 Table 2 However, o (%) = 100 (%) - C (% l - 1 [(%
).

Further, this polyester was placed on the sample stage of a first edition optical microscope, and the optical anisotropy was confirmed by raising the temperature and applying abrasion stress. As a result, it showed good optical anisotropy at 313° C. or higher.

In addition, the fluidity of this polymer was extremely good, with a viscosity of 1,400 voices at 353°C and a sliding speed of 3,000 (1/sec), and the logarithmic viscosity was 3.7 d, Q/g. .

This polymer was further polymerized in 5 batches under the same conditions, pulverized in the same manner as in Example 1, and then injection molded. The bending elastic modulus is 14 GPa, the isot impact value (mold notch) is 32 kg・(7)/(7), and the thermal deformation temperature is 2.
It had excellent mechanical and thermal properties at 46°C.

Examples 3-15 Kanooxybenzoic acid (I>, 4.A'-dihydroxybiphenyl (ff), t-butylhydroquinone (I[I)
, phenylhydroquinone (rV), 2,6-diaceI-xinaphthalene (V), hydroquinone (vI),
2.5-di([-butyl)hydroquinone (■), 2
．． 5-di(isopropyl)hydroquinone (■), 2
．． 5-di([-amyl)hydroquinone (IX), 2.
5-di(cyclohexyl)hydroquinone (X), 2
．． 5-bis(dimethylbenzyl)hydroquinone, <
X engineering) 2.5-diphenylhydroquinone (XI), terephthalic acid (XI), isophthalic acid (XIV) [(II) + (II[) + (rV)) (V door)
(Vl)+(■)+(Ml+)+(IX)=(X)+
(XI)+(XI)]=[(XIII)+(XIV)]
Prepare the composition as shown in Table 3 as the number of moles of [(
1)+2X[(II)+ (I)+ (TV)” (
VI) + (■) + (■) 10 (IX) = (X) + (X
I) + (XII)] in an amount of 1.2 times the amount of acetic anhydride and reacted at 130 to 250°C for 5 hours in a nitrogen gas atmosphere, and then at 250 to 340°C for 2.0 hours. After further reaction and heating to 350℃, 0.2 to 0.6 m
The pressure was reduced to ml (), and the polycondensation reaction was further carried out for 0.5 to 1.0 hours to obtain a brown polymer.

This polymer's liquid crystal starting temperature, melt viscosity (liquid crystal starting temperature +
Table 3 shows the logarithmic viscosity.

It can be seen from this table that these polyesters have extremely excellent fluidity.

<Effects of the Invention> The aromatic polyester of the present invention can be melt-molded, and molded products with excellent fluidity and heat resistance can be obtained from the aromatic polyester of the present invention, and can be used in various applications such as engineering plastics. can do.

Claims (1)

[Claims] Consisting of the following structural units (I) to (III), the structural unit (
I) is 40 to 90 mol% of the total, unit [(II) + (III
)] constitutes 60 to 10 mol% of the total, and the structural unit (I
The molar ratio of I)/(III) is 9/1 to 1/9, and the temperature is 60°C.
An aromatic polyester having good fluidity, characterized in that it has a logarithmic viscosity of 1.0 to 20.0 dl/g when dissolved in pentafluorophenol at a concentration of 0.1 g/dl. ▲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) (However, the X in the formula 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,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼
Y is one or more groups selected from ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼
, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ Indicates one or more groups selected from 65 mol% or more of it is in the para position. )