JPS58180524A - Crystallization accelerator for thermoplastic polyester and polyester resin composition containing same - Google Patents

Abstract

PURPOSE:A crystallization accelerator which, when added to a thermoplastic polyester, causes less degradation of polyester, allows rapid crystallization and causes no softening of the resin, comprising a specified polyester oligomer. CONSTITUTION:A crystallization accelerator for thermoplastic polyesters, which comprises a polyester oligomer in which above 90mol% of the dicarboxylic acid residues are terephthalic acid residues and above 90mol% of the diol residues are 2-6C aliphatic diol residues (e.g., ethylene glycol residues), said oligomer having an intrinsic viscosity of below 0.4, and above 1mueq./g of groups of the formula, wherein Me is an alkali metal bound to molecular terminals. This crystallization accelerator, when added to a thermoplastic polyester, can suppress degradation of the polyester as low as possible and exhibit a large effect of promoting crystallization without detriment to the excellent properties inherent in the polyester.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermoplastic polyester crystallization accelerator and a polyester resin composition containing the same.

More specifically, a crystallization accelerator characterized by comprising a polyester oligomer having 1 μ equivalent/or more of a group represented by the general formula % (Me represents an alkali metal) bonded to the molecular chain end; A polyester resin composition comprising:

Although polyethylene terephthalate (hereinafter referred to as PET) has excellent physical strength, electrical properties, and heat resistance, until now it has been used as a molding resin only by polybutylene terephthalate (hereinafter referred to as PET), which is a type of thermoplastic polyester. It lags far behind the Japanese government (also known as T). The reason for this is due to the poor moldability of PET, and this poor quality is due to the fact that PET has a lower crystallization rate during injection molding than PBT. It promotes early extrusion of poorly crystallized molded products from the mold, and it also has the possibility of continuing to crystallize with a unique volume change during product use, resulting in poor dimensional stability. . In order to achieve sufficient crystallization in a special injection mold, it is necessary to keep the mold temperature at 130°C or higher and the molded product therein for a long time, which is disadvantageous in terms of energy. This is a fatal flaw for engineering resins, which are not stupid and have long molding cycles.

In order to improve the injection moldability of PIT,
Research to improve the crystallization rate of ET has been vigorously pursued, and various crystallization promoters have been discovered. However, each has its advantages and disadvantages. For example, fine inorganic nucleating agents such as talc do not have a large effect on promoting crystallization, and metal salts of organic carboxylic acids such as sodium benzoate and sodium stearate have a large effect on promoting crystallization, but they promote the decomposition of polyester. Therefore, it is not desirable. Furthermore, polymers with carboxylic acid metal salts in their side chains (e.g., ethylene-methacrylic acid-alkali metal methacrylate ternary copolymers), so-called ionomers, have a large effect of promoting crystallization and are less likely to cause degradation of polyester. This has the disadvantage of greatly reducing the rigidity of the material.

In view of the situation described in Section F, the present inventors conducted various studies in order to obtain a compound that minimizes the decomposition of polyester and exhibits a large crystallization promoting effect without reducing the original excellent physical properties of polynisdel. As a result, we have arrived at the present invention. That is, the present invention provides a method in which at least 90 mo/l/% of dicarboxylic acid residues are terephthalic acid residues,
At least 90 dio/L' residues have 2 or more carbon atoms.
A polyester oligomer consisting of aliphatic di-/L/@l groups of 0.4
A thermoplastic resin comprising a polyester oligomer having an intrinsic viscosity of less than A crystallization accelerator for plastic polyester and a polyester resin composition containing gold therein.

In the polyester oligomer used as a crystallization promoter in the present invention, at least 90 moles of the dicarboxylic acid residues are terephthalic acid residues and at least 90 moles of the sidiol residues are aliphatic di- fi7$U
Consists of base. By using such a polyester oligomer, it is possible to prevent the physical properties of the polyester from deteriorating, which promotes crystallization. As the aliphatic diol having 2 to 6 carbon atoms, ethylene glycol, globylene glycol/L
Examples include 1.4-butanedio-11,6-hexanediol and neobentyl glycol.

Less than 10% of the dicarboxylic acid component and/or diol component may be replaced with components other than those mentioned above, but examples of such dicarboxylic acid component or diol component include isophthalic acid, orthophthalic acid, adipic acid, and sebacic acid. , L4-hexane dimetatool and polyethylene glycol.

The polyester oligomer used in the present invention is
a Viscosity (pheno-iv/tetofuclolethane 1:1 (
Weight ratio) (measured value at 50°C in a mixed solvent) is required to be less than 0.4. When the intrinsic viscosity is 04 or higher, the number of terminal groups decreases, so
This is not preferable because it becomes difficult to combine a large amount of l&f. There is no particular restriction on the lower limit of the degree of polymerization, but if it is too small, bleed-out to the surface of the molded product is likely to occur and decomposition of the polyester is also likely to occur, so it is preferable that the degree of polymerization is 2 or more.

The polyester oligomer used in the present invention is
At the end of the molecular chain, there is a group represented by the general formula -000Me of 1μ
It is necessary that the bonding amount is at least equivalent/g, preferably at least 10 μequivalent/f, particularly preferably at least 50 μequivalent/f. If the number of such groups is less than 1 μ equivalent/9, the effect of promoting crystallization will be reduced, which is not preferable. There is no particular restriction on the upper limit, and the larger the value, the greater the crystallization promoting effect, so the groups described above may be bonded to all molecular chain terminals. -Me in the above group represents an alkali metal, and sodium and potassium are preferably used as the alkali metal.

Examples of methods for producing the polyester oligomer used in the present invention include the following two methods. One method is to proceed the polycondensation reaction until a predetermined degree of polymerization is reached in the same manner as the usual polyester polycondensation method, and then add dicarboxylic acid tm to stop the polycondensation and introduce a carboxyl group at the terminal. , further react with an alkali metal compound to convert the carboxyl group into an alkali metal salt, or dissolve the oligomer obtained by polycondensation in an appropriate solvent to have a bonding property to the hydroxyl group end of the oligomer. A carboxyl group is introduced at the end by reacting a functional group (e.g., a bony acid chloride group) with a compound having a carboxyl group (e.g., terephthalic acid monochloride), and then a carboxyl group is introduced into an alkali metal group by reacting a carboxyl group with an alkali metal compound. This is a method of turning it into salt.

Another method involves carrying out a polycondensation reaction of polyester in the presence of an alkali metal compound, and stopping the polycondensation when a predetermined degree of polymerization is reached. There is C. The alkali metal compounds used to convert carboxyl groups into alkali metal salts include, for example, caustic alkalis such as sodium hydroxide and potassium hydroxide, alkali metal alcoholides such as sodium methylate, sodium ethylate, and potassium butyfut; Examples include alkali metal salts of weak acids such as potassium formate. Caustic alkali is preferred when added to a polyester polycondensation reaction system, and potassium butyfut is most preferred when added to a solution of polyvarnish 7'μ oligomer.

Also by the method described above, more than 20 layers of f-COOMe can be converted to f-COOMe at the end of the molecular chain of a polyester oligomer.

The crystallization accelerator for thermoplastic polyester of the present invention can be mixed with thermoplastic polyester by a normal melt mixing method. Examples of thermoplastic polyester include PET,
PBT and a part of these dicarboxylic acid components or diol components' are replaced with ugly dicarboxylic acids (isophthalic acid, ortho-7-acid, adipic acid, sepacic acid, etc.) or di-
Copolymerized polyesters substituted with A/(1,3-propanediol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanedimetatool, polyethylene glyco-y, etc.) can be mentioned. but,
The crystallization accelerator of the present invention has a particularly great effect on polyesters mainly composed of PET or PETt. Suitably, the thermoplastic polyester has an intrinsic viscosity of 0.5 or more. The blending ratio of the crystallization promoter to the thermoplastic polyester is -COOM in the crystallization promoter.
Depending on the content of e-end groups, thermoplastic polyester ~
It is appropriate to blend the -(300Me terminal group) in an amount of 0.1 μ equivalent/g or more, preferably 1 μ equivalent/g or more with respect to the total amount of the crystallization accelerator and the crystallization promoter of the present invention. The content of 1000Me end groups is 1000.
Since μ per unit is 11 or less, thermoplastic polyester 100
It is necessary to mix at least 1 part by weight of the crystallization promoter qO. Furthermore, the crystallization accelerator of the present invention is different from conventionally used crystallization accelerators in that it hardly reduces the rigidity of the compound even if it is blended in large quantities with thermoplastic polyester. However, if it is added in too large a quantity, it may lead to lowering the apparent degree of polymerization of the compound, which may lead to a decrease in strength, so it is usually appropriate to use 25 parts by weight or less per 100 parts by weight of the thermoplastic resin. .

Although the crystallization accelerator of the present invention can be incorporated alone into thermoplastic polyester, a great effect can be obtained;
Even greater effects can be obtained by jointly using plasticizers such as organic esters and polyalkylene glycols described in JP-A-65354, JP-A-54-158452, and JP-A-56-445943. The appropriate amount of these plasticizers to be used is 0.1 to 5 parts by weight per 100 parts by weight of thermoplastic polyester A.

When the crystallization accelerator of the present invention is blended into thermoplastic polynisdel, various auxiliaries, fillers, and pigments may be added to improve the thermal stability, oxidation stability, and light stability of the thermoplastic polyester, if necessary. , a colorant, a flame retardant, a chain extender, a mold release agent, etc. may be added at the same time. Preferred fillers include glass fiber, glass beads, mica, aluminum silicate, asbestos, etc., and the blending ratio is 10 to 15 parts by weight per 100 parts by weight of thermoplastic polyester.
0 parts by weight is suitable.

The thermoplastic polyester, the crystallization accelerator, and the above-mentioned compounding agents can be mixed using known mixing methods, such as drying and melt-mixing each component in a suitable mixer or rotating machine, or mixing the thermoplastic polyester with the crystallization accelerator and the above-mentioned ingredients. This can be carried out by adding it to the reaction system during the polycondensation step. Both temperature and pressure during mixing are not critical and can be carried out under normal conditions. The composition obtained by K in this way is
It can be molded into various shapes 111 such as a block shape, a rod shape, a sheet shape, and a fi/A shape using various known molding methods.

The present invention will be explained more specifically using an example of a dormitory.
The present invention is not limited to such embodiments. In addition, unless otherwise specified, all parts in steel mean parts by weight.

Example 1 190 dimethyl terephthalate in 500d three-necked 7-fusco
immersed in an oil bath kept at ℃. After dissolving dimethyl terephthalate, start stirring using a rotating tool with a diameter of about 63 mm, and set the rotation speed to 3.
0 rpm). After the system reached 190°C, it took about 4 hours for the methanol to stop dripping. Here antimony trioxide (sb2o3) o, o 4t.

Trif I II IV 7 Male 7E) ((C6H50
) 3 F = 0 ) 0.0495f ethylene glycol ~
The mixture was dispersed into approximately 10% and added. After that, increase the oil bath temperature to 2
Ecthermia was started at 80°C. When 240°CK was reached, suction using 7 spirators was started and continued for 50 minutes.

During this time, the temperature of the system reached 280°C. At this stage, add terephthalic acid 109 (0,06!1101) to the outside of the generated water and ethylene glyco-A/l system, stirring at normal pressure for about 1 hour, then switching to a vacuum pump for 50 minutes. When I continued suctioning, the reaction system turned into a clear liquid. P obtained by sampling at this stage
The intrinsic viscosity of the ET oligomer (measured at 50°C in a mixed solvent of pheno-/L//tetofchloroethane (1:1 weight ratio); the same applies hereinafter) is 0.20□, and the average molecular weight calculated from this is 3600 (however, log(η)”
-3,1568+0.685 logMn viscosity -
(using the molecular weight formula). The total number of end groups is therefore 278 x 2μ equivalents/-. Force ~ Phoxyl group t-0,01N-Na0
When quantified using HJ solution, it was 600μ equivalent, /I, indicating that most of the terminals were carboxyl groups.

Sodium hydroxide A L2 f (0.03 mol) t-x was added to the polyester oligomer obtained by 5K.
+Dissolve in about 101F of Lengelicol and add. Immediately, the solution was suctioned with a vacuum bomb 1 for sO to remove the ethylene glyco-A/l used as a solvent. The intrinsic viscosity of the obtained oligomer was ij Q, S Odl/fl, and the average molecular weight calculated therefrom was 6,500. Therefore, the final number is 154×2μ equivalents/g. The carboxyl group is 0.
01 Quantitated with N-NaOH solution, 35μ equivalent/
It was f. This oligomer's infrared absorption spectrum) A
/1kKBr When measured by the tablet method, it is 1580ff.
There was a large peak attributable to the C-O antisymmetric stretching motion of the 111C carboxylic acid at position i. NaO
Almost no peak is observed at this position in the oligomer before H addition, and if it is the sodium terephthalic acid salt produced when free terephthalic acid reacts with N-Hata OH, it is 156
Since it is known that the absorption occurs at the 0 mw position, [X at the 15803 position is bonded to the end of the polyester oligomer and clearly indicates the presence of a 9-COOH group. Additionally, the amount of 100ONa groups determined using sodium terephthalate as an external standard was 120 μeq/f.

5 parts of the polyester oligomer obtained as described above were mixed with 100 parts of PET having an intrinsic viscosity of 0.78, and iT! As a single agent, it was melt-kneaded with 5 parts of polyethylene glycol dimethyl ether having a molecular weight of 1000 in a Plastograph (manufactured by Puchbender) (conditions were 275°C, rotor speed 30 rpm), and the intrinsic viscosity of the resulting composition was measured. This composition was melted at t-280°C and press-molded into a sheet having a thickness of 58 parts, and immediately transferred to a press at 100°C and cooled (4 minutes).

After 4 minutes, it was further transferred to a cooling press kept at room temperature and rapidly cooled. The surface infrared spectrum /L/ of the 5-inch thick sheet obtained by this series of press molding, which can be called pseudo-injection molding (the 100°C press in the middle is equivalent to the mold in injection molding), is Measured its 1342m
absorption (trans OH2 in PE'r crystal (
OcDconfig-uratio of C-C bond rotation
n) of the magnitude of 7953
-1 absorption (1 internal thiakness b
The value t% of the ratio to the size of (ind, PET o) which is not greatly influenced by whether it is crystalline or amorphous is the crystallinity puff meter. This buff meter also indicates the magnitude of the crystallization rate of PET in the composition; the higher the value, the higher the degree of crystallinity. Results! l! Shown in 1. The pottery strength of the sheet was measured using an Instron universal testing machine. The results are shown in Table 1.

Example 2 In the same manner as in Example 1, 100 parts of PET with an intrinsic viscosity of 0.78, 5 parts of the polyester oligomer having a terminal of 100 ONm obtained in Example 1, and 5 parts of neopentyl glycol dibenzoate were added to a defrosting agent. 7
(The line conditions in 5 are the same as in Example 1). After measuring the intrinsic viscosity of this composition, series press molding was performed in the same manner as in Example 1 to obtain a sheet with a thickness of 5 parts, and the crystallinity was measured using a buff meter based on the surface infrared spectrum, and the total bending strength was measured. . The results are shown in Table 1.

Example 3 190 dimethyl terephthalate in a 300-three-neck flask
immersed in an oil bath kept at °C. After dimethyl terephthalate was dissolved, stirring was started using a rotary blade having a diameter of about 6a11 (rotation speed: 50 rpm). It took about 4 hours for the methanol to stop dripping after the system reached 190°C. Here, terephthalic acid 43 f (0,258 mol), ethylene glycol/l/489 (0,774 mol), and potassium hydroxide 3.59 (0,063 mol, potassium hydroxide was added as an ethylene glycol solution) were added. When the temperature reached 280°C, ectotherm started completely. After reaching 280°C, incubation was continued for 50 minutes. The 20 produced by the esterification during the 7-day period was separated from the ethylene glycol by a distillation tube with a length of about 153, and was discharged.

After removing the distillation tube, it was connected to an aspirator and suction was applied for about 40 minutes. Thereafter, the vacuum pump was switched on and suction was carried out for 1 hour. The obtained oligomer had an intrinsic viscosity of 0.27 and a carboxyl group of 54 μ equivalent/'9.

The infrared absorption spectrum A/ of this oligomer is still t
580 car-' IfC-Cool has a large peak indicating the presence of the end, and the amount of -coox group is 10
It was 0μ equivalent/f.

5 parts of the thus obtained friend polyester oligomer were combined with 1QQ part of PET having an intrinsic viscosity of 0.76, and 4I! I
f! It was dissolved in Plastograph along with 1415 parts of polyethylene glycol dimethide with a molecular weight of 1000 as an agent.
The mixture was kneaded (mixing conditions were the same as in Example 1).

After measuring the intrinsic viscosity of this composition, a sheet of 3 g thickness was obtained by series press molding in the same manner as in Example 1, and the crystallization rate and flexural strength were measured using a puff meter. The results are shown in Table 1.

Comparative Example 1 Sheet 1 was obtained in the same manner as in Example 1, except that 100 parts of PΣT with an intrinsic viscosity of 0.78 and 15 parts of polyethylene glycol dimethyl ether/L were kneaded in Example J [1] without blending Boriesdey oligomer. , its crystallinity parameters and bending strength were measured. The intrinsic viscosity of the crosstalk was also measured.

The results are shown in Table 1.

Comparative Example 2 A 3 m
One thick sheet was obtained, and its crystallinity buff meter and bending strength were measured. It is also useful to measure the intrinsic viscosity of the kneaded composition. The results are shown in Table 1.

Comparative Example 5 Instead of blending the polyester oligomer in Example 1, Surlyn 1707 (DuPont, ionomer,
A three-layer thick sheet was obtained in exactly the same manner as in Example 1 except that 8 parts of ethylene-methacrylic acid-alkali metal methacrylic acid ternary copolymer was used, and its crystallinity parameters,
Bending strength was measured.

The intrinsic viscosity of the crosstalk composition was also measured. The results are shown in Table 1.

! 11 As can be seen from the table, all the systems to which the crystallization promoter of the present invention was added had significantly higher crystallinity parameters than the system to which it was not added (Comparative Example 1), indicating that the crystallization promoting effect was It shows that it is excellent.

In addition, a system using sodium stearate, a conventionally used crystallization accelerator (Comparative Example 2), is excellent in terms of crystallinity buff meter, but PET decomposition is severe and the intrinsic viscosity is low. This is not desirable in this respect. Furthermore, in the case of using an ionomer (Comparative Example 3), PE
It also has less decomposition of T, which is preferable in terms of crystallinity buff meter.

The composition tends to soften and its bending strength decreases,
This is not desirable in this respect.

Thus, it can be seen that the crystallization accelerator of the present invention causes less decomposition of polyester, rapidly crystallizes the polyester, and does not soften the resin, making it a very preferable crystallization accelerator.

Claims (2)

[Claims] (1) At least 907% of the dicarboxylic acid residues are terephthalic acid residues, and at least 90% of the dicarboxylic acid residues are aliphatic di-/1/$U with a prime number of 2 to 6.
The polyester oligomer has an intrinsic viscosity of less than 0.4 and has a group represented by the general formula % (Me represents an alkali metal) at the end of the molecular chain in an amount of 1 μ equivalent/ 1. A crystallization accelerator for thermoplastic polyester, comprising a polyester oligomer having more than 100 g bonded together. (2) [M] 100 parts by weight of a thermoplastic polyester having an intrinsic viscosity of 0.5 to 1; and (B'') at least 90 moles of dicarboxylic acid residues are terephthalic acid residues; s) t -A/residues; At least 90 mofi/% of the aliphatic geo-A/s with leg primes 2 to 6
A polyester oligomer consisting of one group, the polyester oligomer has an intrinsic viscosity of less than 0.4, and has a group represented by the general formula % (Me represents an alkali metal) at the end of the molecular chain in an amount of 1 μ equivalent. A polyester resin composition containing 0.01 to 25 parts by weight of polyester oligomers having /f or more bonds.