JP3487378B2 - Method for producing polyarylene sulfide resin molded article - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention has a high crystallization rate,
The present invention relates to a method for producing a polyarylene sulfide resin molded product having a sufficient crystallinity even when molded at a mold temperature as low as 0 ° C or less.

[0002]

2. Description of the Related Art Polyphenylene sulfide (hereinafter referred to as PP
Polyarylene sulfide (hereinafter abbreviated as PAS) resin represented by a resin (S) is excellent in heat resistance itself,
Molding materials, which have chemical resistance and are reinforced with reinforcing materials such as glass fiber, are being used as metal substitutes in the fields of automobile parts, electronics-related parts, etc. There is.

However, the PAS resin represented by the PPS resin is originally a crystalline resin, but it has a drawback that the crystallization rate is very slow. For this reason, other thermoplastic resins such as polyethylene, polypropylene, polyacetal, polybutylene terephthalate, and polyamide may be used at room temperature to 10
In contrast to molding at a mold temperature of 0 ° C, PAS resin cannot be molded into a fully crystallized mold unless the mold temperature is 120 ° C or higher, generally 150 ° C or higher. Even if it can be molded at the mold temperature, the molded product appearance and releasability from the mold itself are extremely poor, and the molded product can be obtained only when the molded product is deformed or cracked. It was often not. In addition, a molded product molded at a low mold temperature has a defect that it is deformed when left in an atmosphere having a glass transition temperature or higher. In addition, since the mold temperature is higher than 150 ° C, the worker is liable to get burned, especially during insert molding, and the mold temperature rise time is longer than usual, or the mold life is long. There was also a problem of poor workability such as short length. Furthermore, for example, in precision molded products that are extremely disliked by the occurrence of burrs and require heat resistance such as solder heat resistance, burrs are suppressed and mold release is possible at a mold temperature of less than 90 ° C. After molding, it was necessary to perform post-treatment such as annealing at 120 ° C. or higher to sufficiently raise the crystallinity and use the PPS resin in a state where the original heat resistance was not lost.

In order to solve these problems, the following method has been proposed as a method for high-speed crystallization using a die at a relatively low temperature. The method of adding an oligomeric ester described in JP-A-62-45654, the method of adding another thioether described in JP-A-62-230849, and the carboxylic acid ester described in JP-A-62-230848 Method of addition, JP-A-62-230850, JP-A 1-22
5660, a method of adding a phosphoric acid ester described in JP-A-3-91563, a method of adding a certain silicon compound containing a mercapto group described in JP-A-2-225565, JP-A-6-192473. 1, 2, 3, described in Japanese Patent Publication
A method of adding a 4-butanetetracarboxylic acid imide compound and the like.

[0005]

However, among these methods, ~ is not sufficient in the effect of promoting crystallization, or if a large amount is added to increase the effect, the compound or resin is generated during molding or use. There is a practical problem that gas or decomposed gas is generated to cause inconvenience such as adhesion to a mold or the like for contamination, deterioration of the environment, and adverse effects on physical properties. Although the method (1) is relatively effective, it uses 1,2,3,4-butanetetracarboxylic acid or its anhydride as a starting material, and thus is very expensive, resulting in an increase in cost. Further, it has a high hygroscopicity, and if a large amount of this is added, the water absorption of the PPS molded article becomes large, and there is a drawback that the physical properties such as electrical characteristics or mechanical characteristics in a high humidity atmosphere are deteriorated.

[0006]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made it a drawback in the past, particularly in injection molding, by increasing the crystallization rate when a PAS resin composition, particularly a PPS resin composition, is melted and solidified. The need for a high mold temperature, which was previously required, has sufficient crystallinity even when molding at a low mold temperature, and has earnestly studied to obtain a low-cost PAS resin molded product that does not adversely affect various physical properties. As a result, in the composition obtained by adding a small amount of the specific imide compound and the crystal nucleating agent to the PPS resin, the crystallization rate at the time of melt solidification is high, and further, the crystallinity is high even at a mold temperature lower than the conventional one, Further, they have found that a PAS resin molded product having good heat resistance can be molded, and completed the present invention.

That is, the present invention provides a polyarylene sulfide resin (a) represented by the following general formula:

[0008]

[Chemical 2]

(Wherein A is an aliphatic group, an alicyclic group or an aromatic group, and X ₁ and X ₂ are a hydrogen atom, an alkyl group or a halogen), and a monoimide compound (b) and The present invention relates to a method for producing a polyarylene sulfide resin molded article, which comprises molding a polyarylene sulfide resin composition containing a crystal nucleating agent (c) as an essential component at a mold temperature of 90 ° C or higher and lower than 120 ° C.

An example in which the same maleimide compound used in the present invention is added to a PPS resin to increase the melt viscosity of the PPS resin is described in JP-A-63-205357. However, simply increasing the melt viscosity does not solve the above-mentioned problems. The present invention uses a monoimide compound and a crystal nucleating agent in combination and
The PAS composition added in a small amount to the S resin has a high crystallization rate in the case of melt solidification, and has sufficient crystallinity even in molding at a mold temperature lower than that of the conventional PA.
We have found that it is possible to manufacture S molded products,
The present invention described above is based on such findings.

The PAS resin as the base material in the present invention is
A polymer containing a repeating unit represented by the general formula [-Ar-S-] (wherein -Ar- represents a divalent aromatic group containing at least one carbon 6-membered ring) in an amount of 70 mol% or more. so,
The representative substance is structural formula [-φ-S-] (however, -φ
-Represents a repeating unit represented by p-phenylene group) 70
It is a polymer containing at least mol%.

PAS resins are generally known to have a substantially linear molecular structure having no branched or crosslinked structure and one having a branched or crosslinked structure depending on the production method.
In the present invention, both types are effective. Further, the PPS resin used in the present invention, which has been subjected to washing treatment such as hot water washing, organic solvent washing, and acid washing at the time of its production, has a more effective effect. Desirable for improving crystallization characteristics. Moreover, it is preferable to use a PPS resin having a sodium content of 2000 ppm or less.

A preferred PAS resin (a) for use in the present invention is a PPS resin containing 70 mol% or more of the repeating unit [-φ-S-] (where -φ- is a p-phenylene group). is there. 70 mol% of this repeating unit
When it is above, the crystallinity, which is a characteristic of the crystalline polymer, is high, sufficient strength is obtained, and the toughness and chemical resistance are excellent.

The PPS resin may contain less than 50 mol%, preferably less than 30 mol%, of other copolymerized structural units shown below.

[0015]

[Chemical 3]

[0016]

[Chemical 4]

[0017]

[Chemical 5]

[0018]

[Chemical 6]

[0019]

[Chemical 7]

[0020]

[Chemical 8]

[0021]

[Chemical 9]

[0022]

[Chemical 10]

[0023]

[Chemical 11]

And the like. Of these, the trifunctional unit is 1
It is also preferable that the content is mol% or less from the viewpoint of not lowering the crystallinity.

The monoimide compound (b) used in the present invention is a maleimide compound represented by the general formula (1). More specifically, the monoimide compound used in the present invention is represented by the following general formula (2).

[0026]

[Chemical 12]

[Wherein R ₁ is an alkyl group having 1 to 22 carbon atoms, an alkenyl group, an alkynyl group, a cycloalkyl group having 4 to 6 carbon atoms, or

[0028]

[Chemical 13]

[0029]

[Chemical 14]

A group represented by R ₃ and R ₅ are each an alkyl group having 1 to 22 carbon atoms, an alkenyl group, an alkynyl group,
It represents an aryl group, an aralkyl group, a hydrogen atom or a halogen atom, and R ₂ and R ₄ are single bonds or have 1 to 22 carbon atoms.
In the formula ( ₁₎ , X ₁ and X ₂ represent a hydrogen atom, an alkyl group or halogen. a and b are integers from 0 to 2,
n and m represent the integer of 0-3. The-(D)-group represents an arylene group represented by the following formulas (3) to (5).

[0031]

[Chemical 15]

[0032]

[Chemical 16]

[0033]

[Chemical 17]

Here, X _{3 to} X ₆ represent an alkyl group having 1 to 22 carbon atoms, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group, a hydrogen atom or a halogen atom. ]
Is a monomaleimide compound.

These monoimide compounds are obtained by dehydration condensation of an acid anhydride such as maleic anhydride with an aliphatic-class amine, an alicyclic-class amine, or an aromatic-class amine having a predetermined structure. It can be easily obtained by decarboxylation reaction with an isocyanate derivative of amine,
The present invention does not define this.

Examples of the aliphatic-grade amine used in the present invention include methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, undecylamine, dodecylamine, tridecylamine. Examples include decylamine, tetradecylamine, pentadecylamine, hexadecylamine, heptadecylamine, octadecylamine and derivatives thereof.

Cyclobutylamine, cyclopentylamine, cyclohexylamine, alicyclic-primary amine,
Cyclohexylmethylamine, cyclohexylethylamine, methylcyclohexylamine, dimethylcyclohexylamine and their derivatives are mentioned.

As the aromatic-classified amine, methylaniline, ethylaniline, propylaniline, butylaniline, pentylaniline, hexylaniline, heptylaniline, octylaniline, nonylaniline, decylaniline, undecylaniline, dodecylaniline, tridecylaniline. , Tetradecylaniline, pentadecylaniline, hexadecylaniline, heptadecylaniline, octadecylaniline and derivatives thereof.

The amines preferably used among these secondary amines are aliphatic amines having 4 or more carbon atoms and their derivatives, or aromatic amines and their derivatives.

As a dehydration reaction for producing these monoimide compounds, a method by heating is industrially most preferable, but a dehydrating agent such as acetic anhydride-pyridine or carbodiimide may be used if necessary. Is not limited.

In some cases, the monoimide compound of the present invention may have an organic functional group in the molecule of the imide compound. The organic functional group used in the present invention is -COO.
_{H, -OH, -NH 2, -CN} , NO 2, -NCO, -O
They are CN, -SH, an oxazoline group, and a glycidyl group.
The monoimide compound of the present invention may be a metal salt, for example, a metal salt of sodium, calcium, potassium, magnesium, barium, aluminum, zinc or the like is used, preferably a metal salt of sodium or calcium.

The amount of the monoimide compound of the present invention used is PP
The amount is 0.1 to 20 parts by weight, preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the S resin. If it is less than 0.1 part by weight, the effect of the present invention is not obtained, and if it exceeds 20 parts by weight, the physical properties are extremely deteriorated.

On the other hand, the crystal nucleating agent (c) used in the present invention
Is a commonly known crystal nucleating agent. Specifically, talc, mica, silica, kaolin, clay,
Attapulgite, romite powder, quartz powder, zinc white, diatomaceous earth, montmorillonite, verculite, amorphous silica, crystalline silica, glass powder, alumina silica, wollastonite, hytron, boron nitrite, carbon black, pyro Inorganic nucleating agents such as ferrite, graphite, zinc sulfide, boron nitride, silicon resin powder, calcium, magnesium, aluminum, lithium, barium, titanium silicates, sulfates, phosphates, aluminates, oxides, etc., fats Aromatic carboxylic acid, metal salt of aromatic carboxylic acid such as benzoic acid and terephthalic acid, aromatic phosphonic acid and its metal salt, aromatic aromatic phosphoric acid ester metal salt, aromatic sulfonic acid such as benzenesulfonic acid and naphthalenesulfonic acid Metal salt of β-diketones, metal salt of carboxyl group That the polymer compound, 4,6 nylon,
Examples thereof include polymer compounds having a melting point higher than that of the PAS resin, such as polyether ether ketone, polyether ketone, and polysulfide ketone, and powdered products thereof. Among these, preferable crystal nucleating agents include talc, boron nitride, and aromatic phosphoric acid ester metal salts.

The amount of the crystal nucleating agent used in the present invention is PPS resin 1
It is 0.05 to 10 parts by weight, preferably 0.1 to 5 parts by weight, relative to 00 parts by weight. If it is less than 0.01, the effect of the present invention is not obtained, and if it is more than 10 parts by weight, the physical properties are extremely deteriorated.

The composition of the present invention may optionally contain
The following reinforcing agents and / or fillers can be added. Examples of these reinforcing materials and / or fillers include powdery, flat, scale-like, needle-like, spherical or hollow and fibrous forms. Specifically, calcium sulfate, calcium silicate, clay, talc, alumina, silica sand, glass powder, metal powder, graphite, silicon carbide, silicon nitride, silica, boron nitride, aluminum nitride,
Granular filler such as carbon black, mica, glass plate, sericite, metal foil such as aluminum flake, flat or scale-like filler such as graphite, shirasu balloon, metal balloon, hollow filler such as glass balloon, Examples thereof include organic fibrous fillers such as glass fibers, carbon fibers, graphite fibers, whiskers, metal fibers, asbestos, wosnite, fibrous fillers and aromatic polyamide fibers.

Further, other thermoplastic resins may be added to the composition of the present invention within a range not departing from the gist of the present invention. Other thermoplastic resins include polyethylene, polypropylene, polystyrene, imide-modified polystyrene, polybutylene terephthalate, polyethylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyamide, polycarbonate, ABS resin. , Imide-modified ABS resin, AES resin,
Polysulfone, polyphenylene ether, copolymer and / or mixture of polyphenylene ether and polystyrene, thermoplastic resin such as polyethersulfone, polysulfide ketone, polysulfide sulfone, polyether ether ketone, polyamideimide, polyester system, Polyamide-based, polyurethane-based, polyolefin-based, polystyrene-based, etc. thermoplastic elastomers, and these thermoplastic elastomers, glycidyl groups, carboxylic acids and acid anhydrides thereof, amino groups, isocyanate groups, mercapto groups, oxazoline groups and other organic functional Examples include modified products modified with an organic compound containing a group. Preferably, polypropylene, polybutylene terephthalate,
Polyamide, polyphenylene ether, copolymer and / or mixture of polyphenylene ether and polystyrene.

In the present invention, an inorganic flame retardant such as magnesium hydroxide, aluminum hydroxide and antimony trioxide, a halogen-based compound, a halogen-based compound,
Add additives such as phosphorus-based organic flame retardants, antioxidants, UV inhibitors, lubricants, dispersants, silane coupling agents, titanium coupling agents, foaming agents, crosslinking agents, colorants, plasticizers, etc. You can

As a method for producing a molded article made of the PAS resin composition of the present invention, a general method is used. The most common method is to blend the formulation with a suitable mixer such as a tumbler,
After uniformly mixing with a Henschel mixer, tumbler, etc., supplying to an extruder, melting and kneading, extruding into a strand shape, cooling, cutting and making into a product for molding material (for example, pellets), this is molded Supplied to the machine and above 90 ℃ 12
There is a method of injection molding at a mold temperature of less than 0 ° C. In short, it is possible to omit the extrusion step and directly supply the compound of the present invention to a molding machine to perform injection molding at a mold temperature of 90 ° C or higher and lower than 120 ° C. It is not prescribed.

As described above, according to the method of the present invention, 90 ° C.
As described above, even at a relatively low mold temperature of less than 120 ° C., it is not necessary to anneal at 120 ° C. or higher after molding, and a molded product with sufficient crystallization can be obtained as it is.

The composition of the present invention can be molded at a mold temperature lower than that of the conventional PAS resin composition and does not impair mechanical properties and heat resistance. Therefore, like the conventional PAS resin, it can be used for various functional parts, and is particularly suitable for those obtained by injection molding. For example, injection molded products are automobile parts, electric machines, electronic components, encapsulating materials, and extrusion products, which are commonly used for profile extrusion,
It is useful as an extruding material for tubes, hoses, pipes, fibers, films, electric wire coatings, blow molding, and rotational molding materials.

[0051]

The present invention will be further described with reference to examples.

Measurement of Melt Index (MI) After drying about 6 g of a sample at 120 ° C. for 3 hours, a predetermined temperature (315.6 ° C.) was set using an orifice having a diameter of 2.096 mm and a length of 8.001 mm. It is put into a melt indexer (T01 type manufactured by Toyo Seiki Co., Ltd.) to remove air bubbles, apply a predetermined load (5000 g), preheat for 5 minutes, and then measure.

HDT (Heat Strain Temperature) Measuring Method The measurement is performed according to ASTM D648. Test piece: length 125 mm x width 12.5 mm x thickness 3.0 mm (injection molded product) Measuring instrument: HDT tester S3FH manufactured by Toyo Seiki Co., Ltd.
Mold load: 4.6kgf / cm ²

[0054]Glass transition temperature (Tg), crystallization temperature
(T _C1 , T _C2 ) and melting point (Tm) measurement About 10 g of the composition of the present invention was added to a chrome mesh having a thickness of 0.6 mm.
Scissors on a plate and put it in a 37t heat press set at 300 ° C.
Set and melt for 3 minutes. Then 20kg in gauge pressure
/ Cm²After applying pressure for 20 seconds, chrome plating
Remove the plate and immediately quench it with cold water at 5 ° C or less
Obtain a PPS sheet. Glass transition temperature, crystallization temperature,
As for the melting point, about 6 mg of this sheet is 50 ° C by DSC.
Temperature to 350 ° C. at a heating rate of 20 ° C./min.
After holding at 50 ℃ for 3 minutes, cooling rate of 20 ℃ / min
At 150 ° C. Journal of Polymer Sciennc
e; Part B; Polymer Physics, Vol.30, 163-176 (1992)
The glass transition temperature (Tg) that appears when the temperature rises, and
And the peak temperature of the crystallization exothermic peak are raised.
_C1), And the endothermic peak is measured as the melting point (Tm).
Decided In addition, the exothermic peak that appears during cooling is cooled down.
Crystallization temperature (T_C2) Was measured.

Usually, JP-A-55-139448,
Plastic Age Vol.28, No.9, 106-113 (1982), Jour
nal of Polymer Sciennce; Part B; Polymer Physics, Vo
As described in l.30, 163-176 (1992), Tg
It is said that a mold having a low T _{c1 and a} low T _c1 can be molded with a relatively low temperature mold, and a mold having a high T _c2 has a faster molding cycle. Therefore, it is necessary for injection molding to satisfy both T _c1 and t _c2. is there.

[0056] Measuring instrument: Perkin Elmer DSC7 Atmosphere: In nitrogen atmosphere

Examples 1 to 3 and Comparative Examples 1 to 3 As PPS resin (1), linear type PP washed with hot water having MI of 300 g / 10 minutes and sodium content of 356 ppm.
S resin as an imide compound (2) was synthesized from maleic anhydride and laurylamine

[0058]

[Chemical 18]

The lauryl maleimide represented by the formula (1) was blended with talc (manufactured by Micron White Hayashi Kasei Co., Ltd.) as a crystal nucleating agent (3) using a tumbler with the composition shown in Table 1 and a barrel temperature of 290 ° C. Was kneaded by a twin-screw extruder (TEM-35B manufactured by Toshiba Machine Co., Ltd.), and the extruded strand was cooled and solidified, and then pelletized. The obtained pellets were dried at 120 ° C. for 4 hours, and then, using an injection molding machine (IS-50AM: manufactured by Toshiba Machine), the cylinder temperature was 290 ° C., the mold temperature was 100 ° C. and 15
Molding was performed at 0 ° C to obtain a test piece for HDT measurement. Also, Tg, T _C1 , T _C2 , and Tm were measured according to the method described above.
The results are shown in Table-1.

[0060]

[Table 1]

As is clear from the results, in the present invention, the crystallization rate is increased without lowering the melting point, and the heat resistance is equivalent to that of the molded product by the high temperature mold.

Examples 4 to 6 and Comparative Examples 4 to 6 PAS resins (1) were crosslinked PPS resins with MI of 170 g / 10 min, and imide compounds (2) were represented by the following structural formulas.

[0063]

[Chemical 19]

Phenylmaleimide represented by: and a sodium salt of an aromatic phosphoric acid ester (NA-11 as a crystal nucleating agent (3))
Asahi Denka Kogyo Co., Ltd.) and blended using a tumbler with the composition shown in Table 2 to obtain a barrel temperature of 29.
The mixture was kneaded by a twin-screw extruder (TEM-35B manufactured by Toshiba Machine) set at 0 ° C., and the extruded strand was cooled and solidified, and then pelletized. The resulting pellets are 4 at 120 ° C
After drying for an hour, an injection molding machine (IS-50AM: made by Toshiba Machine) has a cylinder temperature of 290 ° C and a mold temperature of 100 ° C.
Molding was carried out at 150 ° C. to obtain a test piece for HDT measurement.
Also, Tg, T _C1 , T _C2 , and Tm were measured according to the method described above. The results are shown in Table-2.

[0065]

[Table 2]

As is clear from the results, the present invention has a high crystallization rate without lowering the melting point, and has heat resistance equivalent to that of a molded product by a high temperature mold.

[0067]

The crystallization rate is high and the mold temperature is 120 ° C.
Mold temperature is less than 1
It has the same heat resistance and molded product appearance as a molded product molded by a molding machine at 50 ° C. Therefore, according to the method of the present invention, the molding workability is improved, which is also advantageous for the safety of workers.

─────────────────────────────────────────────────── --Continued from the front page (56) Reference JP-A-63-205357 (JP, A) JP-A-6-192473 (JP, A) JP-A-5-140451 (JP, A) JP-A-3- 91563 (JP, A) JP-A 1-225660 (JP, A) JP-A 63-260952 (JP, A) JP-A 62-230850 (JP, A) JP-A 62-81451 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08J 5/00-5/24 C08L 1/00-101/14

Claims (2)

(57) [Claims] 1. A polyarylene sulfide resin (a),
Below-general formula (In the formula, A represents an aliphatic group, an alicyclic group or an aromatic group,
X ₁ and X ₂ are a hydrogen atom, an alkyl group or halogen. ), The polyarylene sulfide resin composition containing the monoimide compound (b) and the crystal nucleating agent (c) as essential components is molded at a mold temperature of 90 ° C or higher and lower than 120 ° C. Manufacturing method of resin molded product. 2. A polyarylene sulfide resin (a).
Is a linear type, a heat-crosslinking type, or a branched type.