KR970006675B1 - Wholly aromatic polyester and method for manufacturing them - Google Patents

Abstract

Wholly aromatic polyester(I) having a chemical resistance, processing ability, fire resistant, and hydrophobic properties is manufactured by reacting mixture of aromatic dicarboxylic acid or its derivatives and bisphenol compound with silica compound(ii). In formula, m,n are constant and within m/m+n is equal to or more than 0 and less than 1 ,n/m+n is more than 0 and equal to or less than 1, R is one selected from C1-C2 aliphatic alkyl or above one of benzene ring containing C6-C12 aromatic alkyl group, R1-R4, R1'-R4' are same or different.

Description

Wholly aromatic polyester and preparation method thereof

The present invention relates to a bisphenol-based wholly aromatic polyester having improved physical properties by introducing a silicon compound, a new wholly aromatic polyester, into the main chain, and a method for producing the same. More specifically, by synthesizing a bisphenol compound having silicon in the conventional wholly aromatic polyester and introducing it into the main chain by the interfacial polymerization method, various physical properties such as chemical resistance, flame retardancy, etc. are maintained while maintaining thermal stability, mechanical properties and electrical properties. The present invention relates to a wholly aromatic polyester having a new structure with excellent adhesion to additives and improved processability, and a method for producing the same.

In general, the whole aromatic polyester prepared by condensation polymerization of aromatic diol and aromatic dicarboxylic acid has thermal properties such as thermal deformation temperature, thermal decomposition temperature, tensile strength, elongation, It is widely used for various molded products, films, fibers, and coating materials by injection molding, compression molding, extrusion molding, etc. due to its excellent mechanical properties such as flexural strength, flexural recovery rate, impact resistance, dimensional stability, combustion resistance, transparency, and electrical properties. It is becoming.

The wholly aromatic polyester is bisphenol A (hereinafter referred to as BPA) as an aromatic diol, terephthalic acid (hereinafter referred to as TPA) and isophthalic acid (hereinafter referred to as IPA) as an aromatic diol. Resin polycondensed using the

In general, methods for preparing wholly aromatic polyesters composed of aromatic dicarboxylic acids and bisphenols include solution polymerization, melt polymerization, and interfacial polymerization, which are described in detail below.

First, in the solution polymerization method, a compound in which an aromatic dicarboxylic acid is treated in an acid chloride state and an aromatic diol are dissolved in a suitable organic solvent, and then pyridine or triethylamine is added as a basic compound to react in a solution. . That is, when preparing the wholly aromatic polyester resin having a structural formula represented by the above general formula, terephthalolyl dichloride (hereinafter referred to as TPDC) and isophthalodine di made of TPA and IPA in the form of acyl chloride Condensation polymerization of chloride (Isophthalolyl dichloride, hereinafter referred to as IPDC) and aromatic diol in the presence of a solvent is classified into a low temperature solution polymerization method and a high temperature solution polymerization method according to the reaction solvent and the reaction temperature. Here, representative examples of the low temperature solution polymerization include US Pat. Nos. 3,234,168, 4,049,629, and 4,051,107. In these patents, tetrahydrofuran (hereinafter referred to as THF) is used as a solvent, -10 ° C. A technique for polycondensation at ˜30 ° C. has been proposed. On the other hand, condensation polymerization at a high temperature of 215 ° C. to 220 ° C. using a high boiling point solvent such as dichloro ethyl benzene or ditolyl methane as a high temperature solution polymerization method is disclosed in US Pat. Nos. 3,133,898, 3702,838 and 3,733,306 and the like. However, such a solvent polymerization method is difficult to obtain a polymer having a high molecular weight and is uneconomical because the recovery and purification cost of the solvent is high.

Second, the melt polymerization method condensation polymerization of a compound obtained by diacetateting an aromatic diol with an aromatic dicarboxylic acid or a compound obtained by diphenyl esterizing an aromatic diol with an aromatic dicarboxylic acid at a high temperature of 220 ° C. to 330 ° C. in the presence of a catalyst. As a method of making, it is shown in Japanese Unexamined Special Publications No. 38-15247, Japanese Unlimited Publication 43-28199, Ilbo Unlimited 53-35796, US Patent Nos. 3,317,464, 3,975,487 and 3,553,167, etc. As the polymerization reaction proceeds, the melt viscosity becomes high, making it difficult to stir, and thus it is difficult to obtain a high molecular weight polymer and the color of the polymer produced due to the high reaction temperature is not very good.

Third, the interfacial polymerization method is a method in which TPDC and IPDC are dissolved in an organic solvent which is not mixed with water, and then polymerized with vigorous stirring while adding aromatic diol to a solution dissolved in an aqueous solution of caustic soda. At this time, a phase transfer catalyst such as a quaternary ammonium salt may be used if necessary [P. W. Morgan, J. Macromol. Sci. Chem., A 15, 683 (1981); H.B.Tasi and Y.D.Lee, J.Ploym. Sci., Chem. Ed. 1987, 25, 1505: US Pat. No. 4,229,565]. This polymerization process proceeds very quickly even at room temperature and can easily obtain a high molecular weight polymer, the purity of the raw material is not so much a problem, and also has the advantage of easily adjusting the molecular weight.

On the other hand, the synthesized wholly aromatic polyester resin has a high heat resistance, but the melt viscosity is very large and must be processed at a high temperature of 350 ℃ ~ 400 ℃ due to the breakage and color of the polymer chain tends to decrease the transparency and physical properties There is this. There is a technique to replace some of the RPA and IPA with aliphatic dicarboxylic acid to ameliorate this disadvantage (US Pat. No. 4,126,602). See also the introduction of a flexible group into the main chain [P. Bajaj, DNKhana, Eur. Polym. J., 17, 275 (1981); DNKjana, P. Bajaj and AKGupta, polymer, 24,596 (1983)] or dikars with flexible structures such as -O-, -S-, -SO-, -SO ₂ -and -CO- between two benzene rings. Techniques using acids are disclosed (British Patent 2,085,458). However, most of the modified wholly aromatic polyester resins can be lowered the processing temperature due to the flexibility of the chain, but is not practical because the thermal stability and mechanical strength are significantly reduced.

In order to solve the problems of the conventional wholly aromatic polyester resin, the present invention is a bisphenol having a new type of silicon called bispara-hydroxyphenyl dimethyl silane (hereinafter referred to as bis (p-hydroxyphenyl) dimethyl silane). By synthesizing derivatives and replacing part or all of BPA, it is to provide a wholly aromatic polyester resin having a new structure having chemical resistance, processability, flame retardancy and hydrophobicity while maintaining the thermal stability, mechanical strength and electrical properties of the resin as it is. There is this.

Hereinafter, the present invention will be described in detail.

The present invention is a wholly aromatic polyester represented by the following structural formula (I).

Here, m, n is an integer ranging from 0≤m / m + n1, 0n / m + n≤1, and R is an aliphatic alkyl group having 1 to 2 carbon atoms or carbon atoms containing at least one benzene ring 6 Selected from aromatic alkyl groups up to ˜12. In addition, R ₁ ~ R ₄ , R ₁ '~ R ₄ ' are the same or different and each is selected from a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms or derivatives thereof. The present invention will be described in more detail with reference to the manufacturing method as follows.

The BPSi used to prepare the new wholly aromatic polyester according to the invention was synthesized using the method mentioned in the literature [W. Davidsohn et al, J. Organic metal, Chem., 36,283 (1972)]. The synthetic route is described in detail below.

In the above formula, R is selected from an aliphatic alkyl group having 1 to 2 carbon atoms or an aromatic alkyl group having 6 to 12 carbon atoms including at least one benzene ring. In other words, the para-bromophenol solution dissolved in anhydrous tetrahydrofuran is slowly added to a container containing n-butyllithium at -70 ° C. After the end of the process, the reaction temperature is left to 0 ℃ and stirred to form a white gel of the formula (A). The white gel of formed (A) was again cooled to -70 ° C and then slowly added a dimethyldichloro silane solution diluted in tetrahydrofuran. After completion of the addition reaction, hydrolysis with dilute hydrochloric acid afforded the compound of formula (B). Silicon-containing bisphenol (BPSi) synthesized as above is added to alkaline aqueous solution with BPA while varying the molar ratio from 0.05 to 1.0 with respect to BPA, and TPDC, IPDC and phase transfer catalyst are added to the organic solvent of dichloromethane. Axis matching was carried out by the interfacial polymerization method.

The wholly aromatic polyester resin of the present invention in which the BPSi represented by the above formula (I) is introduced into the main chain has an intrinsic viscosity of 0.05 to 0.5 dL / g, and is not easily dissolved in organic solvents such as halogenated carbon and tetrahydrofuran. It does not have a characteristic, the initial decomposition occurs in the range of 470 ℃ to 510 ℃, and has a glass transition temperature (Tg) of 120 ℃ ~ 190 ℃. In addition, thermal analysis shows that 30% ~ 40% of residues in nitrogen and 2% ~ 15% in air are present at 700 ℃, which greatly affects the flame retardancy of the resin. The digestion time was confirmed to be shorter. The silicon-containing wholly aromatic polyester resin of the present invention is lower as the glass transition temperature (Tg) is increased as the content of BPSi compared to the wholly aromatic polyester resin consisting of only BPA, TPDC, and IPDC, which is polymerized with conventional BPA only. BPSi, which has increased flexibility due to the introduction of silyl groups than the wholly aromatic polyester, is introduced into the polymer chain, thereby reducing the melt viscosity at high temperature and consequently facilitating processability. In addition, the thermal decomposition temperature is about 470 ℃ ~ 510 ℃ exhibiting a similar value to the conventional wholly aromatic polyester resin while reducing the melt viscosity at high temperature shortens the high temperature residence time, thereby reducing the coloring and thermal decomposition generated during processing Can be reduced. In addition, the silicon-containing polyester resin of the present invention exhibited insolubility in general organic solvents and increased chemical resistance, and a considerable amount of residues existed during thermal analysis, and as a result, the flame retardancy evaluation (UL-94) showed that the flame retardant properties were greatly improved. .

In the present invention, the wholly aromatic polyester of the general formula (I) was synthesized using the bisphenol compound of the following general formula (III) together with the bisphenol of the general formula (II) containing silicon.

Intrinsic viscosity (η _inh ) measured in the present invention was measured at a temperature of 25 ℃ using a weight ratio of phenol and 1,1,2,2-terachloroethanol 6: 4 as a solvent, the concentration of the sample is 1.0 g / dl. Intrinsic viscosity (η _inh ) was obtained by the following equation.

Here, t ₁ is the time for the solution to pass through the capillary of the viscometer, t ₂ is the time for the solvent to pass, and C is the concentration expressed in g / dl.

The present invention will be described in detail based on Examples and Evaluation Examples. However, the present invention is not limited to this embodiment.

Synthesis Example 1

Synthesis of Bis (para-hydroxyphenyl) dimethyl silane [Bis (p-hydroxyphen-yl) dimethyl sil ane: BPSi]

243 ml (0.316 mol) of n-butyllithium (1.3M cyclohexane solution) was injected into a 1 L reactor equipped with a stirrer, a thermostat, a nitrogen injector, and a dropping funnel, followed by cooling to -70 ° C. To this solution was slowly added 27.3 (0.158 mol) of para-bromophenol solution dissolved in 400 ml of tetrahydrofuran at a rate such that the reaction temperature did not exceed -50 ° C, and then the reaction temperature was gradually raised to 0 ° C. At this time, when the solution turns to a white gel state near -10 ° C, the stirring temperature is increased to break the gel finely and the solution temperature is cooled back to -70 ° C. To this solution is added 5.75 ml (0.047 mol) of dimethyldichloro silane solution dissolved in 40 ml of tetrahydrofuran over 5 minutes. After the addition is completed, the reaction solution is gradually raised to room temperature and then hydrolyzed with diluted hydrochloric acid. The reaction solution was distilled under reduced pressure at a temperature not exceeding 40 ° C. to remove tetrahydrofuran, and then dissolved in ethyl ether solution. The organic solvent layer was washed several times with distilled water and then water was removed with a moisture desiccant and the ethyl ether solvent was dried under reduced pressure again to obtain a sticky solid. This type of solid can be obtained after washing the impurities with pentane or nucleic acid in the form of a white powder BPSi (10.51, yield 91%). The structure of the product was confirmed by ¹ H-NMR spectrum, the results are shown in Table 5.

Example 1

200 ml of 0.1N NaOH aqueous solution, 9.12g (0.04mol) bisphenol-A (hereinafter referred to as BPA), 2.44g (0.01mol) BPSi and 0.05g hydro Disulfide salt is added and stirred at a speed of 450 rpm. Here, 5.08 g (0.025 mol) of isophthalic dichloride (hereinafter referred to as IPDC), 5.08 g (0.025 mol) of terephthalic dichloride (hereinafter referred to as TPDC) and 0.024 g of tetrabutylammonium Quickly add 100 ml of the bromide dissolved methane dichloride solution. After performing interfacial condensation polymerization for 1 hour at a temperature between 5 ° C. and 30 ° C., the organic solution is washed with alkaline aqueous solution, acid aqueous solution, and aqueous solution, and then the reaction mixture is added to 300 ml of methanol to precipitate the polymer, followed by filtration and separation. . The obtained polymer was dried in a vacuum dryer at 80 ° C. for 24 hours to obtain a white powdery polymer (PAR-①). Table 1 shows the intrinsic viscosity (η _inh ) and the yield of this polymer.

In addition, the structure of PAR-① was confirmed from the ¹ H-NMR spectra shown in Table 6.

Example 2

A polymer (PAR-②) was obtained using an aqueous alkali solution in which 6.84 g (0.03 mol) of BPA and 4.88 g (0.02 mol) of BPSi were dissolved together in the same manner as in Example 1. The viscosity (η _inh ) and the yield are shown in Table 1. In addition, the structure of PAR-② can be confirmed from the ¹ H-NMR spectra shown in Table 7.

Example 3

In the same manner as in Example 1, an alkaline aqueous solution in which 4.56 g (0.02 mol) of BPA and 7.32 (0.03 mol) of BPSi was dissolved together was used. Table 1 shows the intrinsic viscosity (η _inh ) and the yield of the obtained polymer (PAR-③).

Example 4

In the same manner as in Example 1, an alkaline aqueous solution in which 2.28 g (0.01 mol) of BPA and 9.76 g (0.04 mol) of BPSi was dissolved together was used. Table 1 shows the intrinsic viscosity (η _inh ) and the yield of the obtained polymer (PAR-④).

Example 5

In the same manner as in Example 1, an alkaline aqueous solution in which 12.2 g (0.05 mol) of BPSi was dissolved was used. Table 1 shows the intrinsic viscosity (η _inh ) and the yield of the obtained polymer (PAR-⑤).

Comparative Example 1

Into a 1 liter reactor equipped with a stirrer, a nitrogen injector, and a dropping funnel, 200 ml of 0.1N NaOH aqueous solution, 11.4 g (0.05 mol) of BPA and 0.05 g of hydrosulfite salt were added and stirred at a speed of 450 rpm. To this is quickly added 100 ml of a methane dichloride solution in which 5.08 g (0.025 mol) of IPDC, 5.08 g (0.025 mol) of IPDC and 0.024 g of tetrabutylammonium bromide are dissolved. After performing interfacial condensation polymerization for 1 hour at a temperature between 5 ° C. and 30 ° C., the organic solution is washed with an alkaline aqueous solution, an acid aqueous solution, and an aqueous solution, and then the reaction mixture is added to 300 ml of methanol to precipitate a polymer and then filtered. The obtained polymer was dried in a vacuum dryer at 80 ° C. for 24 hours to obtain a white powder polymer (PAR-⑥). Table 1 shows the intrinsic viscosity (η _inh ) and the yield of the obtained polymer (PAR-⑥).

[Evaluation Example 1]

Solubility Assessment

Table 2 below shows the experimental results of the solvent of the wholly aromatic polyester resin prepared by the above examples.

* In Table 2, ○: complete dissolution △: partial dissolution ×: insoluble

According to the above experimental results, the most aromatic polyester resins prepared from TPDC, IPDC, and BPA (Comparative Example 1), which have low chemical resistance, depend on compounding or blending for products requiring such properties. Improve chemistry However, it was shown that the wholly aromatic polyester resin (Example 3, Example 4, Example 5) of this invention which contains a predetermined amount or more of silicon in a principal chain has the outstanding chemical-resistance to a general solvent. Therefore, the resin of the present invention has shown the possibility that it can be used in products requiring chemical resistance.

[Evaluation Example 2]

Differential Scanning Calorimeter (DCS)

The glass transition temperature (Tg) of the wholly aromatic polyester prepared in Examples 1 to 5 and Comparative Example 1 was measured at a heating rate of 10 ° C./min in a nitrogen atmosphere using DSC. The results are shown in Table 3.

[Evaluation Example 3]

Thermo Gravimetric Analyser (TGA)

The decomposition temperature of the wholly aromatic polyester prepared in Examples 1 to 5 and Comparative Example 1 was 10% weight loss temperature (T) and decomposition start temperature (T) at a temperature rising rate of 10 ° C./min in nitrogen and air using TGA. ), Maximum decomposition temperature (T), and the amount of residue (R) at 700 ° C. were measured. The results are shown in Table 3.

As shown in Table 3, the wholly aromatic polyester resin containing silicon in the main chain did not show any significant weight change even when heated to around 470 ° C to 510 ° C (see Tables 8 and 9) and obtained from Examples 1 to 5 In the wholly aromatic polyester resin, the glass transition temperature decreased from 120 ° C to 180 ° C as the content of the silicon compound increased.

[Evaluation Example 4]

Flame Retardant Test

The wholly aromatic polyester resin prepared in Examples 1 to 5 and Comparative Example 1 was formed at a molding temperature of 340 ° C. and an injection pressure of 1200 Kg / cm. 1/16 × 1/2 × 5 inches (thickness × width × length) of each specimen, prepared and ignited according to UL-94's flame retardancy evaluation method, and then fired from the moment the fire was removed. Flame retardancy was evaluated by measuring the time and evaluation grade of.

As shown in Table 4, as the Si content is inserted into the main chain as compared to the conventional resin, it can be seen that the fire extinguishing time is shortened after the removal of the flower source. It was confirmed that the remarkable improvement.

H-NMR analysis results of bisphenols containing a wholly aromatic polyester resin and silicon in the context of the present invention are shown in Tables 5 to 7.

Table 5 shows bisphenols (BPSi) containing silicon. Table 6 shows the results of the analysis using H-NMR, and Table 6 shows the total aromatic polyester resin containing silicon compound synthesized at a molar ratio of 2: H-NMR, Table 7 shows the total aromatic polyester resin containing a silicon compound obtained by synthesizing the molar ratio of BPSi to the molar ratio of 4: 6 to BPA. H-NMR. In addition, the results of thermal analysis (TGA) for Examples 1 to 5 and Comparative Example 1 under nitrogen atmosphere are shown in Table 8, and the results in air are shown in Table 9.

Claims (6)

The wholly aromatic polyester containing the silicon represented by the following general formula (I). Herein, m and n are integers in the range of 0 ≦ m / m + n1, 0n / m + n ≦ 1, and R is an aliphatic alkyl group having 1 to 2 carbon atoms or carbon number containing at least one benzene ring. It is selected from the aromatic alkyl group which is 6-12. In addition, R ₁ ~ R ₄ , R ₁ '~ R ₄ ' are the same or different and each is selected from a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms or derivatives thereof. A wholly aromatic polyester containing silicon represented by the general formula (I) by reacting the silicon-based compound represented by the general formula (II) to the wholly aromatic polyester main chain composed of an aromatic dicarboxylic acid or a derivative thereof and a bisphenol compound Manufacturing method. Where m and n are integers m / m + nnn / m + n In the range of 1, R is selected from an aliphatic alkyl group having 1 to 2 carbon atoms or an aromatic alkyl group having 6 to 12 carbon atoms including at least one benzene ring. In addition, R ₁ ~ R ₄ , R ₁ '~ R ₄ ' are the same or different and each is selected from a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms or derivatives thereof. Here, R is selected from an aliphatic alkyl group having 1 to 2 carbon atoms or an aromatic alkyl group having 6 to 12 carbon atoms including at least one benzene ring. The method for producing a wholly aromatic polyester according to claim 2, wherein the bisphenol-based compound is a compound represented by the general formula (III). Here, R ₁ ~ R ₄ , R ₁ '~ R ₄ ' are the same or different and each is selected from a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms or derivatives thereof. The methylene chloride solution of an aromatic dicarboxylic acid chloride containing an aqueous alkali solution and a phase transfer catalyst of bisphenols containing silicon represented by general formula (II) and bisphenols represented by general formula (III) A method for producing a wholly aromatic polyester which is mixed and reacted by interfacial polymerization. The method for producing a wholly aromatic polyester according to claim 2, wherein the amount of the bisphenol compound containing silicon represented by the general formula (II) is 0.05: 0.95 to 1.0: 0 molar ratio relative to the bisphenol represented by the general formula (III). . The method for producing an wholly aromatic polyester according to claim 2, wherein the interfacial polycondensation reaction temperature is in the range of 5 ° C to 30 ° C.