JPH0370773A - Polyarylene sulfide resin composition having improved crystallinity - Google Patents

Abstract

PURPOSE:To obtain a polyarylene sulfide resin composition having improved crystallinity and high crystallization rate by compounding a specific amount of a crystalline oligomer having a specific flow temperature. CONSTITUTION:The objective composition is produced by compounding (A) 100 pts.wt. of a polyarylene sulfide resin with (B) 0.01 30 pts.wt. (preferably 0.1-20 pts.wt.) of a crystalline oligomer having a flow temperature of <=35 deg.C (temperature corresponding to a melt viscosity of 48,000 poise measured by extruding a hot molten polymer through a nozzle having an inner diameter of 1mm and a length of 10mm using a capillary rheometer at a heating rate of 4 deg.C/min) and composed mainly of the recurring unit of formula.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a polyarylene sulfide resin composition with improved crystallinity, that is, with a high crystallization rate.

[Conventional technology]

Polyarylene sulfide resins, such as polyphenylene sulfide, have been attracting attention in recent years as engineering plastics with excellent heat resistance, flame retardance, rigidity, and chemical resistance, and demand has been increasing, especially for applications such as electrical parts and automobile parts. There is. However, since this resin has a high glass transition temperature and a slow crystallization rate, when a molded article is obtained from this resin by injection molding, it is necessary to set the mold temperature to 130° C. or higher. This is a considerably high temperature compared to other engineering plastics such as nylon and polybutylene terephthalate resin, and it is desired that molding can be performed at a lower mold temperature by increasing the crystallization rate of the resin.

[Problem to be solved by the invention]

In the case of polyethylene terephthalate resin, it is known that by adding an inorganic substance as a nucleating agent for crystal nuclei (hereinafter referred to as a nucleating agent), the crystallinity of the resin can be improved and the processability can be improved. As for sulfide resins, few attempts have been made to improve processability by adding a nucleating agent.

[Means to solve the problem]

As a result of intensive studies on nucleating agents that improve the crystallinity of polyarylene sulfide resin, the present inventors found that the resin has a specific flow temperature: inner diameter 1 mm, length 1 mm.
Using a capillary rheometer with a 0 mm nozzle,
Salinity at which the melt viscosity is 48,000 poise when the heated melt is extruded from the nozzle at a heating rate of °C/min.

The polyarylene sulfide used in the present invention is a polymer represented by the general formula -eAr-3+-7, where -Ar
-, for example, has discovered that the above object can be achieved by adding a specific amount of a liquid crystalline oligomer as a component, and has arrived at the present invention.

That is, the present invention provides polyarylene sulfide resin 1
00 parts by weight, the flow temperature determined by the following method is 3.
The present invention provides a polyarylene sulfide resin composition with improved crystallinity, which has a temperature of 50° C. or lower and is made by adding 0.01 to 30 parts by weight of a liquid crystalline oligomer as a component.

It is an aromatic residue, and each aromatic ring has F, CI, B
Substituents such as r and CHs may also be introduced.

Particularly typical polyarylene sulfide has the general formula −
It is polyphenylene sulfide (hereinafter abbreviated as PPS) represented by ←〈□S←S+-1, and is generally commercially available, for example, under the trademark "Rydon" from Phillips Petroleum Company in the United States. The manufacturing method is described in U.S. Patent No. 3,354,129 and the corresponding Japanese Patent Publication No. 4
It is disclosed in Japanese Patent No. 5-3368, and N-methyl-2
- It can be produced by converting paradichlorobenzene in a pyrrolidone solvent at 160 to 250°C under pressure. In addition, Special Publication No. 52-12240, Special Publication No. 52-12240,
As disclosed in Japanese Patent Publication No. 3-25588 and Japanese Patent Publication No. 53-25589, when a catalyst such as lithium acetate or lithium chloride is used in combination, the degree of polymerization of P is further increased.
PS can also be manufactured.

The liquid crystalline oligomer used in the present invention as a component having a specific flow temperature is one that is composed only of the repeating structural unit (hereinafter abbreviated as POB oligomer), or one that is composed of the repeating structural unit and other repeating structural units. It is composed of a combination (hereinafter abbreviated as copolymerized oligomer),
It can be obtained by general reactions called acetitorsion method and phenyl esterification method, solution polymerization using a high boiling point solvent, and melt polymerization substantially free of solvent.

The flow salinity of the oligomer is 350° C. or less when measured by the method described above using a capillary rheometer. In this case, at the temperature at which the molten polyarylene sulfide resin solidifies and crystal nuclei are generated, the oligomer forms a crystalline structure and functions as an excellent nucleating agent.

If the flow temperature is higher than 350°C, the oligomer will not melt during melt-kneading, making it impossible to obtain a uniform composition.

Regarding the relationship between the flow temperature and molecular weight of the oligomer, -C is:
Only the oligomer with low flow temperature is tetrafluorophore 1.
It is only slightly soluble in special solvents such as alcohol,
It's difficult to clarify. However, by accurately measuring the amount of acetic acid distilled out in the acetitorsion method and the amount of phenol distilled out in the phenyl esterification method, it is possible to estimate the number average degree of polymerization of the oligomer. A correlation with flow temperature can be obtained.

The amount of the oligomer containing the O-turn structural unit as a main component depends on the flow temperature of the oligomer, but is generally in the range of 0.01 to 30 parts by weight per 100 parts by weight of polyarylene sulfite. When the amount of the oligomer added is less than 0.01 parts by weight, almost no crystallinity improvement effect is observed, and 30
If the amount exceeds 1 part by weight, the crystallinity is greatly improved, but the oligomer may partially decompose during melt mixing and the composition may foam.

In view of the balance between the nucleating effect and other physical properties, the amount of the OIJ sesame added to 100 parts by weight of polyarylene sulfide is particularly preferably in the range of 0.1 to 20 parts by weight.

Furthermore, in the present invention, heat stabilizers, antioxidants, ultraviolet absorbers, lubricants, mold release agents, dyes, pigments, flame retardants, flame retardant aids, which are usually added to polyarylene sulfide resins as necessary, One or more types of additives such as antistatic agents can be blended.

Also small amounts of other thermoplastics (e.g. polyethylene,
One or more types of thermosetting resins (eg, phenolic resin, epoxy resin, etc.) can be added.

Furthermore, reinforcing agents such as glass fiber, carbon fiber, boron fiber, silicon carbide fiber, asbestos fiber, and metal fiber,
It is also possible to incorporate fillers such as clay, mica, talc, silica, graphite, glass beads, alumina, and calcium carbonate. In particular, filling of glass fiber or carbon fiber has a remarkable effect of improving rigidity and heat resistance, and in order to provide a more useful composition, it is preferable to fill the entire composition in a range of 1O to 60wtX. . The fibers are chipped strands, chipped fibers, or long fiber rovings, which are bundles of several hundred to several thousand single fibers with a diameter of 5 to 15 μm and a length of 3 to 8 mm, and the average fiber length is added to the final composition. is 0°15~0.5mm
It is preferable to uniformly disperse the amount within the range of .

The raw material mixing means for obtaining the molding material of the present invention is not particularly limited. That is, it is common to mix the polyarylene sulfide resin and the oligomer with fillers such as glass fibers, pigments, heat stabilizers, etc. using a Henschel mixer, tumbler, etc., and then melt-knead them using an extruder, etc. .

[Action of the invention]

The oligomer, which has a specific flow temperature, is molten during kneading, and a uniform composition can be obtained without causing poor dispersion due to secondary aggregation, unlike inorganic nucleating agents. In addition, the oligomer forms a crystal structure at a temperature at which the polyarylene sulfide resin matrix solidifies and crystal nuclei are generated, and functions as an excellent nucleating agent.

〔Effect of the invention〕

The composition of the present invention has a higher crystallization rate than polyarylene sulfide resin alone, and therefore, in injection molding, it is possible to mold at a lower mold temperature and shorten the molding cycle.

〔Example〕

Examples of the present invention will be shown below, but the present invention is not limited thereto. In addition, the physical properties in Examples were measured by the following method.

○Flow temperature: Flow tester C manufactured by Shimadzu Corporation
The melt viscosity was measured using an FT-500 model, and when extruding an oligomer heated and melted at a heating rate of 4°C/min through a nozzle with an inner diameter of 1 mm and a length of 10 mm under a load of 100 kg/cm, the melt viscosity was 48. This is the temperature at a point showing .000 poise.This temperature is a measure of the degree of polymerization.

○Optical anisotropy: The optical anisotropy of the resin in the molten state is
The temperature of a powdered oligomer placed on a heating stage was raised at 10° C./min under polarized light, and observation was performed with the naked eye. In addition, if complete melting was not achieved under standing conditions, spring pressure was used to perform the melting under increased pressure.

- Crystallization temperature: 10 mg of the composition was melted by heating at 360°C for 5 minutes, and then immersed in liquid nitrogen to freeze the amorphous state. This material was heated at a rate of 10° C./min, and the exothermic peak accompanying crystallization was measured using a differential scanning calorimeter (DSC), and the peak temperature was defined as the heating crystallization temperature. Furthermore, 36
After incubating at 0° C. for 5 minutes, the temperature was lowered at a rate of 10° C./min, and the crystallization temperature at lower temperature was measured in the same manner as when the temperature was raised.

Examples 1 to 10, Comparative Examples 1 to 4 (Synthesis of POB oligomer) N-mer (n = 2.3.4.5.7.9.12) POB oligomers were synthesized according to the following procedure. 10 moles of p-hydroxybenzoic acid and 10(n-1)/n moles of acetic anhydride were charged into a polymerization tank equipped with an anchor-type stirring blade that was sufficiently purged with nitrogen, and the temperature was raised while stirring in a nitrogen gas atmosphere to 180 mols of acetic anhydride. When the temperature reached °C, the reaction was carried out under reflux for 3 hours to effect acetylation. Thereafter, the temperature was raised to 300°C, and the reaction was continued until the distillation of acetic acid by-produced by acetylation and acetic acid by-produced by condensation stopped, and the system was gradually cooled while crushing the reactants under strong stirring. After reaching a temperature of 120° C. or lower, the reaction mixture was taken out of the system. This was ground to 200 μm using a wire micron pantam mill.
Particles were set to be less than m.

Assuming that 100x acetylation has been achieved, calculating from the distilled amount of by-produced acetic acid, it is n・2.3.4°5,7
．． 9. The number average degrees of polymerization of POB oligomers corresponding to 12 n-mers are 1.8, 2, 6, 3, 5, 4, respectively.
．． It was 3°6.2.8.0.10.6. Furthermore, the flow temperature and the temperature at which optical anisotropy of these oligomers was determined were determined by the methods described above. The oligomer with a number average degree of polymerization of 10.6 did not flow at temperatures below 350°C and did not exhibit optical anisotropy even under pressure. These results can be expressed as family 1
are summarized in Furthermore, in order to confirm the terminal groups of these oligomers, infrared absorption spectra were measured using the KBr method.
A peak based on a hydroxyl group was detected near cm-', and a peak based on an acetyl group at 1.370 cm-' was not detected. Therefore, it was shown that both oligomers were terminally terminated with p-hydroxybenzoic acid which did not undergo acetylation.

(Characteristics of the composition) Polyphenylene sulfide (manufactured by Topren Co., Ltd.,
Various POB oligomers synthesized by the above method were mixed with "Toprene" PPS T-4) in the composition shown in Table 2, and the total amount of 40 g was mixed at 320 ° C. using a new Brabender Plastomill manufactured by Toyo Seiki Co., Ltd. Under high purity nitrogen, 50
The mixture was melt-kneaded at rpm for 5 minutes (Examples 1 to 10, Comparative Examples 2 to 4). Similarly, polyphenylene sulfide PPS T-4 containing no POB oligomer was also melt-kneaded (Comparative Example 1). The crystallization temperatures of these samples were measured by the method described above, and the results are summarized in Table 2.

The compositions of Examples 1 to 10 comprising the compositions of the present invention all have lower heating crystallization temperatures and higher cooling crystallization temperatures than the composition containing no POB oligomer (Comparative Example 1), that is, crystallization It can be seen that the properties have been improved. In addition, in a system in which a POB oligomer with a flow temperature of 250°C and a number average degree of polymerization determined from the amount of distilled acetic acid of 4.3 was added, the amount added was less than 0.01 part by weight (Comparative Example 2) The effect of improving crystallinity was slight, and when the amount added was more than 30 parts by weight (Comparative Example 3), the composition foamed violently when taken out from the Brabender blast mill. Furthermore, P with a number average degree of polymerization of 10.6 determined from the amount of distilled acetic acid
In the system in which OB oligomer was added (Comparative Example 4), the oligomer did not melt during melt-kneading and a uniform composition could not be obtained.

Examples 11 to 15, Comparative Example 5.6 (Synthesis of copolymerized oligomer) Copolymerized oligomers having the repeating structural units shown below were synthesized in the following procedure.

p-acetoxybenzoic acid 1,080 g (6 mol), terephthalic acid 249 g (1.5 mol), isophthalic acid 83
g (0.5 mol) and 540 g (2 mol) of 4.4゛-diacetoxydiphenyl were charged into a polymerization tank having an anchor-type stirring blade, and the temperature was raised while stirring in a nitrogen gas atmosphere, and the reaction was carried out at 310°C. 510g (8.5 moles) of acetic acid
At the time of flow out, the temperature was lowered to 280° C., 138 g (1 mol) of p-hydroxybenzoic acid was added, and the reaction was continued until the distillation of acetic acid stopped, and then the reaction mixture was taken out of the system. The terminal end of the reaction mixture reacts with the carboxyl group of p-hydroxybenzoic acid, and theoretically becomes a hydroxyl terminal. Grind this with a wire Micron pantam mill to 20
The flow temperature and optical anisotropy temperature were determined using the method described above for particles of 0 μm or less.
It was 00℃.

(Characteristics of the composition) The copolymerized oligomer synthesized by the above method was added to polyphenylene sulfide PPS T-4 so as to have the composition shown in Table 3, and the crystallization temperature was measured in the same manner as in Examples 1 to 10. It was summarized in 3. POB also in the case of copolymerized oligomers
It can be seen that it has a nucleation effect similar to oligomers (Examples 11 to 15). Furthermore, when the amount added was less than 0.01 parts by weight (Comparative Example 5), the effect of improving crystallinity was slight, and when the amount added was more than 30 parts by weight (Comparative Example 6), the composition foamed violently. .

Claims (2)

[Claims] (1) The flow temperature determined by the following method for 100 parts by weight of polyarylene sulfide resin is 350°C or less, and the liquid crystalline property is mainly composed of the repeating structural unit of ▲Formula, chemical formula, table, etc. 0.01 oligomer
-30 parts by weight of a polyarylene sulfide resin composition with improved crystallinity. Flow temperature: Using a capillary rheometer with a nozzle with an inner diameter of 1 mm and a length of 10 mm, when extruding the heated melt through the nozzle at a heating rate of 4°C/min, the melt viscosity is 48,
Temperature indicating 000 poise. (2) The resin composition according to claim 1, wherein the polyarylene sulfide is polyphenylene sulfide.