JPH0354221A - Flame-retardant, optically anisotropic polyester - Google Patents

Abstract

PURPOSE:To improve the flame-retardant properties of an optically anisotropic polyester without adversely affecting the balance between mechanical properties and heat resistance by incorporating specific structural units into the polyester. CONSTITUTION:A diacylated product of an arom. dihydroxyl compd., an arom. dicarboxylic acid, and ethylene glycol are reacted to produce a flame-retardant, optically anisotropic polyester which has a melt viscosity [measured with a Koka type Flow Tester at the liq. crystallization-starting temp. plus 40 deg.C and at a shear rate of 1,000(1/sec)] of 10-15,000P and a logarithmic viscosity (measured at 0.1g/dl concn. in 60 deg.C pentafluorophenol) of 0.5-5.0dl/g and comprises structural units selected from the group consisting of structural units of formulas I to VII [wherein R1 is formula VIII, etc.; Y is C(CH3)2 or SO2; n is 0-2; m is 0 or 1; R2 is formula IX or X, etc.; R3 is formula XI, etc.; R4 is formula IX or XII, etc.; X1 to X4 are each H, Cl, or Br, and at least one of them is not H; and (formulas III+IV+V) and (formulas VI+VII) are substantially equimolar to each other]. In these formulas, the ratio of (formulas I+II+III+IV +V) is 40-5mol%; and the molar ratio of (formulas I+II) to (formulas III+IV) is (75:25)-(95:5); and formula XIII is satisfied.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention provides a polymer with a high degree of polymerization that can be obtained only by melt polymerization, and has excellent optical anisotropy, heat resistance, and rigidity that can be formed using an ordinary molding machine. , relates to a flame-retardant polyester that has mechanical properties such as impact resistance and is excellent in flame retardancy.

(Conventional technology) In recent years, the demand for higher performance plastics has been increasing, and a large number of 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)
No. 95, JP-A-49-72393>.

As the above-mentioned liquid crystal polymer, for example, a liquid crystal polymer obtained by copolymerizing p-hydroxybenzoic acid with polyethylene terephthalate is known (Japanese Patent Laid-Open No. 72393/1983). However, injection-molded products made of this polymer have the drawbacks of insufficient heat resistance and poor mechanical properties, and it is difficult to obtain injection-molded products that satisfy both properties from this polymer. Understood. 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 p-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 found out something.

Furthermore, when copolymerizing monomers with aliphatic units such as polyethylene terephthalate, the flame retardance is inferior to that of fully aromatic liquid crystalline polyester, so it is not suitable for applications that require flame retardancy, such as electronic and electrical applications. It was found that the addition of flame retardant was essential for this purpose. Techniques for imparting flame retardancy to polyesters that generally have poor flame retardancy, such as polyethylene terephthalate and polybutylene terephthalate, by adding flame retardants are known in the industry, but when a large amount of flame retardant is added, It is known that there are problems such as deterioration of retention stability and mechanical properties, and bleed-out of flame retardant.

<Problems to be Solved by the Invention> The present invention solves the above problems and provides a shaped product with improved flame retardance without impairing the balance between the excellent mechanical properties and heat resistance of liquid crystal polyester. The objective is to obtain a flame-retardant polyester that can

<Means for Solving the Problems> As a result of intensive studies to achieve the above object, the inventors of the present invention have found that an aromatic compound containing a chlorine atom and/or a bromine atom having a specific structure is copolymerized. The present inventors have discovered that essentially flame retardancy can be obtained even when a polyester produced from ethylene glycol and an aromatic dicarboxylic acid is copolymerized, and the above object can be achieved, and the present invention has been achieved.

That is, the present invention consists of a structural unit selected from the following structural units (I) to (VI), and the structural unit [ () + (
II) + (I[[) + (IV)] is [(I)
+ (I) + (III) + (IV) + (
V)] 60 to 95 mol%, the structural unit (V) is [(■
〉+ (II) + (III) + (IV) +
(V) ]-40 to 5 mol%, and the structural unit [()
+(II)]/[(III)+(IV)] T:R ratio is from 75/25 to 95/5, and the number of moles of each structural unit satisfies the formula (A>) This invention relates to a flame-retardant optically anisotropic polyester.

. ,. 1, [I] [III] +
+ [I] + [II] [II[] + [IV] [
VI] + [VI] (A> +O-Rl-0+- +O-R.-0+- +0-CH 2CH2 -0-}- +CO-R 3-CO+- +C○-R4-CO-}- <However ( III) In the formula, R represents one or more groups selected from, Y is C(CH3)2
or SO2, n represents O-2, and m represents O or 1. R2 in formula (1v) represents a group of at least 7':l selected from R3 in formula (Vl) and R4 in formula (■) represents a group of at least 7':1 selected from. X1~ in each formula
X4 is selected from a hydrogen atom, a chlorine atom or a bromine atom,
At least one is not a hydrogen atom. In addition, the structural unit [
(I([) + (IV> + (V)] and [(VI
)+(■)] are substantially equimolar. 〉 The above structural unit () is a structural unit of a polyester produced from 4-hydroxybenzoic acid in which at least one of the 3.5-positions is substituted with chlorine or bromine; for example, 3-chloro-4-hydroxy Examples include benzoic acid, 3-bromo-4-hydroxybenzoic acid, 3,5-dichloro-4-hydroxybenzoic acid, and 3,5-dibromo-4-hydroxybenzoic acid.

The above structural unit (II) is a structural unit of polyester produced from p-hydroxybenzoic acid.

In addition, the above structural unit (DH is 4.4゜゛-dihydroxybiphenyl, 2.2-bis(
4-hydroxyphenyl)propane, bis(4-hydroxyphenyl)sulfone, 4 in which at least one of the 1.1- and 2.2-positions is substituted with a chlorine atom or a bromine atom
．． Aromatic dihydroxy selected from 4'-dihydroxy-3.1.5.5-tetramethylbiphenyl and hydroquinone in which at least one of the positions 2, 3, 5, 6 is substituted with a chlorine atom or a bromine atom. A structural unit derived from a compound or its derivative, examples of which include 3
．． 3-. 5.5---Tetrabromobisphenol A,
4,4'-dihydroxy-3.3+. 5.5"-tetrabuphenyl, bis(3,5-dibromo-4-hydroxyphenyl)sulfone, 4.4°-dihydroxy-
2,2゛-dibromo-3,3゜. Examples include 5.5-tetramethylbiphenyl and its ethylene oxide adduct, and 3.3-,5.5-1tetrabromobisphenol A or its ethylene oxide adduct is preferred.

In addition, the above structural unit (IV) is 4.4-dihydroxybiphenyl, hydroquinone, 2,6-dihydroxynaphthalene, 2.7-dihydroxynaphthalene, 4.4-dihydroxydiphenyl ether, t-butylhydroquinone, 3.3°,5.5”-tetramethyl-4,4
The structural unit (V) is a structural unit produced from an aromatic dihydroxy compound selected from monodihydroxybiphenyl and phenylhydroquinone or its derivative, and the structural unit (V) is a structural unit produced from ethylene glycol.
> means that at least one of the hydrogen atoms at the 2.2″ and 6.6-positions of the aromatic ring of 1.2-bis(phenoxy)ethane-4.4-1-dicarboxylic acid is substituted with a chlorine atom or a bromine atom. This refers to a structural unit produced from an aromatic dicarboxylic acid or a derivative thereof selected from a dicarboxylic acid and a terephthalic acid in which at least one hydrogen atom on an aromatic ring is substituted with a chlorine atom or a bromine atom. Structural units (■) are terephthalic acid, isophthalic acid, 4.4''-diphenyldicarboxylic acid, 2,6-naphthalene dicarboxylic acid, 1.2-bis(phenoxy)ethane-4.4''
-dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, or a derivative thereof.

A preferable combination of these t# structural units is [ (
I) + <IV) + (V) + (Vl> ] are mandatory precepts, and [ () + (II)
+ (IV) + (V) + (Vl) ] or [(f
A polyester consisting of f>+(III)+(IV)+(V)+(■>) is preferable, and is preferable as R2.

The flame-retardant optically anisotropic polyester of the present invention consists of the structural units (I) to (■), and the structural units [()+(I)+
(III) + (IV) ] is [(■〉+ (II)
+ (III) + (IV) + (V) ]ノ6
It is 0 to 95 mol%, preferably 80 to 92 mol%. Moreover, the structural unit (V) is [(I)+(II)+ (I
II) + (IV) + (V)], preferably 45 to 5 mol%, more preferably 20 to 8 mol%. Structural unit (V) is [()+ (II)+ (I[[)+
If (IV>+ (V)) is less than 5 mol %, the fluidity of the molded product will be impaired, and if it exceeds 40 mol %, the heat resistance of the molded product will not be sufficient, which is not preferable in either case.

Also, among the above structural units, the structural unit [(ENG〉+(I)]
The molar ratio of /[(III)+(IV)] is 75/25 to 9
5/5, preferably 78/22 to 92/8. If it is less than 75/25 or greater than 95/5, the heat resistance or fluidity will be poor, making it impossible to achieve the object of the present invention.

Furthermore, each of the structural units (I) to (VI) must satisfy the following condition.

. ．． . 1, [I] [I] ++ [I] + []I] [III] + [IV] If the value of this formula is less than 0.01, the effect of improving flame retardance is not sufficient. No effect is obtained. On the other hand, if it is larger than 1, mechanical properties and heat resistance may deteriorate, which is not preferable.

The method for producing the flame-retardant optically anisotropic polyester of the present invention is not particularly limited, and it can be produced according to known polyester polycondensation methods.

A typical method for producing the flame-retardant optically anisotropic polyester of the present invention includes the following method.

(1) Acetoxycarboxylic acids such as 4-chloro-3-acetoxybenzoic acid, p-acetoxybenzoic acid, 4.4-1-diacetoxybiphenyl, 3.3-. 5.5--Diacylated aromatic dihydroxy compounds such as tetrabromobisphenol A and paraacetoxybenzene, aromatic dicarboxylic acids such as terephthalic acid, and polymers or oligomers thereof or bis(β- A method of producing hydroxyethyl) terephthalate, etc. through acetic acid removal polycondensation reaction.

(2) Hydroxycarboxylic acids such as 4-chloro-3-acetoxybenzoic acid and p-hydroxybenzoic acid, 4,4°-dihydroxybiphenyl, 3.3-. 5.5-Aromatic dihydroxy compounds such as tetrabromobisphenol A and hydroquinone, aromatic dicarboxylic acids such as acetic anhydride and terephthalic acid, ethylene glycol, and aromatic dicarboxylic acids, and their oligomers or bis(β-hydroxyethyl ) A method of producing terephthalate, etc. by deacetic acid polycondensation reaction.

Although these polycondensation reactions proceed without a catalyst, a catalyst may be used. Examples of the catalyst used in the polycondensation reaction include stannous acetate, tetrabutyl titanate, potassium acetate, antimony dioxide, magnesium, and sodium acetate.

Further, the melt viscosity of the flame-retardant optically anisotropic polyester of the present invention is preferably 10 to 15,000 poise, particularly 20 to 5,000 poise.
．． 000 poise 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 flame-retardant optically anisotropic polyester of the present invention can be measured in pentafluorophenol at a concentration of 0.1 g/cH and 60°C, and is 0.5 to 5.0 dll/cH.
g is preferable, and 1.0 to 3. Odd/. is particularly preferred.

In addition, when polycondensing the flame-retardant optically anisotropic polyester of the present invention, 3.3--diphenyldicarboxylic acid, 2. Aromatic dicarboxylic acids such as 2-1 diphenyldicarboxylic acid, aliphatic dicarboxylic acids such as adivic acid, azelaic acid, sebacic acid, dodecanedioic acid, alicyclic dicarboxylic acids such as hexahydroterephthalic acid, methylhydroquinone,
4,4°-dihydroxydiphenyl sulfide, 4.4
'-dihydroxybenzophenone, 2,2-bis(4-
Aromatic diols such as hydroxyphenyl>propane, bis(4-hydroxyphenyl>sulfone), 1.4-butanediol, 1.6-hexanediol, neopentyl glycol, diethylene glycol, polyethylene glycol, 1.4-cyclohexanediol, 1. Aliphatic and alicyclic diols such as 4-cyclohexanedimethanol, aromatic hydroxycarboxylic acids such as m-hydroxybenzoic acid and 2.6-hydroxynaphthoic acid, etc., in small proportions that do not impair the purpose of the present invention. Further copolymerization can be carried out within the range of .

The thus obtained flame-retardant optically anisotropic polyester of the present invention can be obtained by melt polymerization alone, exhibiting good optical anisotropy, mechanical properties, and heat resistance, and can be formed by extrusion molding,
It can be subjected to ordinary melt molding such as injection molding, compression molding, and blow molding, and can be processed into fibers, films, three-dimensional articles, containers, hoses, etc.

Furthermore, the molded article obtained exhibits excellent flame retardancy.

In addition, for the flame-retardant optically anisotropic polyester of the present invention, reinforcing agents such as glass fiber, carbon fiber, and asbestos, fillers, lubricants, mold release agents, nucleating agents, plasticizers, heat stabilizers, ultraviolet absorbers, Pigments, dyes, other thermoplastics, etc. can be added as needed to impart desired properties. Also,
In order to impart further flame retardancy, a flame retardant and a flame retardant aid such as an antimony compound may be used in combination.

Although any means can be used to blend fillers, additives, reinforcing agents, etc. into the flame-retardant optically anisotropic polyester 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 (e.g. nitrogen, argon, helium or steam) or in an oxygen-containing atmosphere (e.g. air) at a temperature below the melting point of the volima. The heat treatment may or may not be under tension, and can be carried out for several tens of minutes to several days.

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

Example 1 828.6 g (4.80 mol) of 3-chloro-4-hydroxybenzoic acid, p
-Hydroxybenzoic acid 165.7+r (1.20 mol), 4.4--dihydroxybi7enyl 149. Og
(0.80 mol) and anhydrous vinegar R816.7g (8
．． 36 mol), terephthalic acid 132.9 g (0.80
mol) and 230.6 g (1.20 mol) of polyethylene terephthalate having an intrinsic viscosity of about 0.6 were charged, and acetic acid depolymerization was carried out under the following conditions.

First, under a nitrogen gas atmosphere at 100 to 250°C for 5 hours,
After reacting at 50 to 300°C for 1.5 hours, 300°C,
The pressure was reduced to 0.5 g Hg during the working time, and the reaction was further carried out for 2.25 hours to complete the polycondensation, and almost the theoretical amount of acetic acid was distilled out to obtain a volima.

The theoretical structural formula of this Borima is as follows, and the elemental analysis results showed good agreement with the theoretical value.

/+OCH2 CH2 O→1n k. / M / m / n / o = 6 0
/ 1 5 / 1 0 / 1 5/25 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 268° C., indicating good optical anisotropy.

This Borima is Sumitomo Nestal injection molding machine Promat 4
0/25 (manufactured by Sumitomo Heavy Industries, Ltd.) under the conditions of a cylinder temperature of 290°C and a mold temperature of 90°C. 32"
A combustion test piece measuring 1/2" thick x 5" long was prepared.

The flexural modulus was measured using a 1/8" thick test bead and Tensilon UTM-100 manufactured by Toyo Baldwin under conditions of a strain rate of 1!ltIII/min and a span distance of N5oTrn. The flexural modulus was 9. 6G
It was Pa.

Further, as a result of performing a vertical combustion test according to the UL94 standard using a combustion test piece, the flammability was found to be V-0.

The logarithmic viscosity (in bentafluorophenol, at 60° C.) of this bolimmer was 1.67 dN/g, and the melt viscosity was 2200 voids at a shear rate of 1.000 (1/sec), indicating extremely good fluidity.

Comparative Example 1 Into the same reaction vessel as in Example, p-human xybenzoin '#t
i828.7 g (6.0 mol), 4.4-dihydroxybiphenyl 149.0 Fr (080 mol) and acetic anhydride 853.5 g (8.36 mol), terephthalic acid 13
2.9 g (0.80 mole) and intrinsic viscosity of approximately 0.6
of polyethylene terephthalate 230.6g (1.2
When polymerization was carried out under the same conditions as in Example 1, a polymer having the following theoretical structural formula was obtained.

+OCH2CH20←/ m k/J! /m/n=7 5/ 1 0/ 1 5/
25 The liquid crystal initiation temperature of this Borima was 275°C.

This bolima was subjected to the same molding machine as in Example 1, and the cylinder temperature was 300°C and the mold temperature was 90°C.
A test piece measuring 1/2" wide x 5 long and a combustion test piece measuring 1/32" thick x 1/2" wide x 5 to long were prepared.

Using a 1/8" thick test bead and Tensilon UTM-100 manufactured by Toyo Baldwin, the strain rate was 1 f.
When the bending elastic modulus was measured under the conditions of flIII/min and span distance of 50III, the bending elastic modulus was 10.2.
It was GPa.

Further, as a result of a vertical combustion test using a combustion test piece according to the UL94 standard, the flammability was 1-2.

Example 2 3-bromo-4-hydroxybenzoic acid (I) 325. 5g (1.5mol), p-hydroxybenzoic acid (II) 621.6g (4.5mol)
, 4.4”-dihydroxybiphenyl 149.0g (
0.80 mol) and acetic anhydride 816.7 g (8.3
6 mol>, 132.9 g (0.80 mol) of terephthalic acid and 230.6 g (1.20 mol) of polyethylene terephthalate having an intrinsic viscosity of about 0.6 were charged, and polymerization was carried out under the same conditions as in Example 1. A volima with the following theoretical structural formula was obtained. This volima showed good optical anisotropy. This volima was injected or shaped under the same conditions as in Example 1, and a combustibility test was conducted. As a result, the flammability was VO.

+OCH. CH2 O→-/ n k/j /m/n/o=18.8/56.2/1 0/
1 5/2 5 Comparative Example 2 Into the reaction vessel of Example 1, 440.4 g (1.7 mol) of 3-bromo-4-acetoxybenzoic acid () and 918.918. = (5.1 mol)
and an intrinsic viscosity of about 0. 614.4g (3.2 mol) of polyethylene terephthalate from No. 6 was charged,
After reacting at 00'C for 2.5 hours, the pressure was reduced to 0.5m+aHg for 1 hour at 300°C, and the reaction was further carried out for 3.5 hours to obtain a borimer having the following structural formula.

A flammability test was conducted using this volima after injection molding in the same manner as in Example 1, and the result was V-2.

+OCH2CH2 0← m k/I /m/n=17/51/32/83 Example 3 In a reaction vessel similar to Example 1, 8 p-hydroxybenzoic acids were added.
28.7g (6.0 mol), 4.4-1-dihydroxy-3.3-,5.5-tetrabu-mobiphenyl 200
．． 7 g (0.40 mol), 74.5' g (0.40 mol) of 4,1-dihydroxybiphenyl and 8535 g (8.36 mol) of acetic anhydride, 1329 g (8.36 mol) of terephthalic acid.
230.6 g (1,20 mol) of polyethylene terephthalate with Fr (0.80 mol> and intrinsic viscosity of about 0.6)
was charged, and acetic acid depolymerization was performed under the following conditions.

First, under a nitrogen gas atmosphere at 100 to 250°C for 5 hours,
After reacting at 50 to 300°C for 1.5 hours, 300°C,
The pressure was reduced to 0.5 mmHg in 1 hour, and the reaction was continued for a further 2.25 hours to complete the polycondensation, whereupon almost the theoretical amount of acetic acid was distilled out, and a borimer having the following theoretical structural formula was obtained. This volima showed good optical anisotropy.

+oCH2 CH2 0→-/n k/j /m/n. /o=7 5/5/5/L 5/2
5 This volima was injected or shaped under the same conditions as in Example 1, and a combustibility test was conducted. As a result, the flammability was VO.

Example 4 P-hydroxybenzoic acid 8 was placed in the same reaction vessel as in Example.
28.7 g (6.0 mol) 4.4 -1-dihydroxybiphenyl 149.0 g (0.8 mol) and acetic anhydride 853.5 g (8.3 benzoic acid 828.7 g (6
．． 0 mol), 4.4-1-dihydroxybiphenyl 149
．． 0 g (08 mol) and acetic anhydride 853.5 g (
8.36 mol>, terephthalic acid 132.9 g (0.8
0 mole> and the logarithmic viscosity is approximately 0.3 d. A polyethylene terephthalate low polymer (1.2 mol) copolymerized with 20 mol % of tetrabromobisphenol A (Q/g) was charged and polymerized in the same manner as in the example to obtain a polymer having the following theoretical structural formula. This volima showed good optical anisotropy.

+0-CH2 C I{2 O÷11/m k/. 0 / m / n / o = 75 / 10 / 3 / 12 / 25 680 parts of this borimer, 20 parts of anhydrous sodium antimonate and 300 parts of glass fiber were melt-blended in an extruder of 40 Trrnφ and then injection molded. I did this. A flammability test was conducted and the result was V-O.

Effects of the Invention The optically anisotropic polyester of the present invention can be used to obtain a polymer with a high degree of polymerization using only the melt polymerization method, and from this polymer, an injection polymer with an excellent balance of heat resistance and mechanical properties and excellent flame retardance can be obtained. Since it can be obtained in shaped products, it can be used in various applications such as electrical and electronic parts as a plastic substitute for metals.

Claims (1)

[Claims] Consisting of structural units selected from the following structural units (I) to (VII), the structural unit [(I) + (II) + (III) + (IV)
] is 60 to 95 mol% of [(I)+(II)+(III)+(IV)+(V)], and the structural unit (V) is [(I)+(II)
)+(III)+(IV)+(V)], and the structural unit is [(I)+(II)]/[(III)+(IV)
] A flame-retardant optically anisotropic polyester, characterized in that the molar ratio of 75/25 to 95/5 and the number of moles of each structural unit satisfy the following formula (A). 0.01≦[I]/([I]+[II])+[III]/
([III] + [IV]) + [VI] / ([VI] + [VII]) ≦
1 (A) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(II) -(O-R_1-O)-...(III) -(O-R_2 -O)-...(IV) -(O-CH_2CH_2-O)-...(V)-(CO-
R_3-CO)-...(VI) -(CO-R_4-CO)-...(VII) (However, R_1 in formula (III) is ▲There are mathematical formulas, chemical formulas, tables, etc.▼ ▲There are mathematical formulas, chemical formulas, tables, etc. Yes ▼ ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ Indicates one or more groups selected from, Y is C (CH_3)
_2 or SO_2, n represents 0 to 2, and m represents 0 or 1. (IV) R_2 in the formula ▲ has a mathematical formula, chemical formula, table, etc. ▼, ▲ has a mathematical formula, chemical formula, table, 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. ▼, ▲ Mathematical formulas, chemical formulas,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ R_3 in the (VI) formula is ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Numerical formulas, chemical formulas , tables, etc. ▼ R_4 in the (VII) formula is ▲ mathematical formulas, chemical formulas, tables, etc. ▼, ▲ mathematical formulas, chemical formulas,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼
Indicates 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.▼. X_1 to X in each formula
_4 is selected from hydrogen atom, chlorine atom or bromine atom,
At least one is not a hydrogen atom. In addition, the structural unit [
(III)+(IV)+(V)] and [(VI)+(VII)] are substantially equimolar. )