JP2003335945A - Polyarylene sulfide resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyarylene sulfide resin composition which can improve resin melt flowability and low temperature mold moldability on the molding of the polyarylene sulfide resin without causing a trouble on thermal and chemical properties of the resin and on the appearances and dimensional changes of the molded articles. <P>SOLUTION: This polyarylene sulfide resin composition is obtained by melt- kneading (A) 100 pts.wt. of a polyarylene sulfide resin with (B) 0.1 to 20 pts.wt. of a specific aromatic phosphate having a number-average polymerization degree exceeding 1 at ≥300°C. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polyarylene sulfide resin composition for molding, particularly for injection molding.
More specifically, it has a remarkable crystallization promoting effect, and a molded product having a sufficient degree of crystallinity can be obtained even if a mold at a relatively low temperature is used in molding, and shrinkage due to irregular crystallization after molding is caused. The present invention relates to a polyarylene sulfide resin composition for molding suitable for molding in which dimensional changes and the like are also improved and the surface condition of the molded product is good when molded.

[0002]

2. Description of the Related Art Electricity ・
BACKGROUND ART For electronic equipment parts materials, automobile equipment parts materials, chemical equipment parts materials, and the like, flame-retardant thermoplastic resins having excellent mechanical properties and high heat resistance and chemical resistance have been required. Polyarylene sulfide (hereinafter abbreviated as PAS) resin typified by polyphenylene sulfide (hereinafter abbreviated as PPS) is also one of the resins meeting this requirement, and particularly PAS resin containing an inorganic fibrous reinforcing agent such as glass fiber. The composition has excellent mechanical strength, and has a good ratio of physical properties to cost, which is increasing the demand.

However, when this resin is processed by injection molding or the like, it has a low crystallization rate when it is solidified from a molten state and has a high glass transition temperature.
Since a locally uneven crystal structure is likely to occur, the surface of the molded product will be uneven in appearance and structure (unevenness), which will also affect the physical properties, and in order to stably perform continuous molding It is necessary to slow down the speed (molding cycle), especially when the mold temperature is low (for example, 130 ° C or less), these obstacles are remarkable and it is necessary to raise the mold temperature. It has the problem of being inferior.

Further, particularly when an inorganic filler such as glass fiber is blended, the fluidity is deteriorated and it becomes difficult to fill the thin portion of the molded product, or the appearance of the molded product is adversely affected. .

As a means for solving the problem of moldability, a method of blending various crystallization accelerators / plasticizers with a resin has been proposed, but it cannot be said to be sufficient.

For example, 1. Addition of oligomeric ester (Japanese Patent Application Laid-Open No. 62-4565)
No. 4) 2. Addition of thioether (JP-A-62-230849) 3. Addition of carboxylic acid ester (JP-A-62-23084)
No. 8 bulletin) 4. Addition of certain phosphoric acid esters (JP-A-62-2308)
Japanese Patent Laid-Open No. 50-58453, Japanese Patent Publication No.
No. 91563, JP-A No. 1-225660, JP-A No. 11-100494) and the like are known, but gas is generated at the time of molding and melting, resulting in roughening of the molding surface or deterioration of mechanical properties. Seen. Among them, the phosphoric acid ester of JP-A-1-225660 is highly effective, but it cannot be said that the thermal stability at the time of melting at high temperature is sufficient, and there are still points to be improved in order to solve the above problems. .

Further, there is a method of adding a volatile substance or a thermally decomposable substance at a high temperature by melt-kneading at a low temperature, but it causes a problem such as generated gas at the time of molding or re-kneading at the time of recycling. become.

[0008]

In view of the present situation, the present inventor has remarkably improved the above-mentioned problems of PAS resin or its composition, and has a problem of thermal and chemical properties, appearance of molded articles, and dimensional change. As a result of repeated studies for the purpose of improving the resin fluidity at the time of molding, the moldability by a low-temperature mold without occurring, it was found that the compounding of a specific aromatic phosphate is extremely effective, and the present invention is completed. It has come.

That is, the present invention is (B) a polyarylene sulfide resin composition obtained by blending 0.1 to 20 parts by weight of an aromatic phosphate represented by the following general formula (I) and melt-kneading at 300 ° C. or higher. is there.

[0010]

[Chemical 2]

[Wherein R¹~ R¹²Are each independent
A hydrogen atom or an alkyl group having 1 to 4 carbon atoms,
X is a bond, -CH_Two-, -C (CH_Three)_Two-, -S
-, -SO _Two-, -O-, -CO- or -N = N-
Yes, n is an integer of 0 or 1, and m is the number average degree of polymerization.
Is represented, and 1 <m <20. ]

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The components constituting the composition of the present invention will be described below.

In the present invention, the base resin is (A) polyarylene sulfide resin and has the structural formula -Ar-
A polymer containing a repeating unit represented by S- (where Ar is an arylene group) in an amount of 70 mol% or more, and a typical substance thereof is structural formula -Ph-S- (where Ph is a phenylene group).
Is a polyphenylene sulfide resin having 70 mol% or more of the repeating unit represented by. Above all, temperature 310
The melt viscosity measured under conditions of ℃ and shear rate of 1200 / sec is 10 to 20,000 poise, especially 100 to 5,000.
Those in the poise range are suitable. 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. It is also effective, but the preferred PAS resin for use in the present invention has 70 mol% or more, more preferably 80 mol% of paraphenylene sulfide units as repeating units.
The main component is a homopolymer or copolymer having a substantially linear molecular structure, which is contained in an amount of at least mol%. If this repeating unit is less than 70 mol%, the original crystallinity, which is a characteristic of a crystalline polymer, tends to be low, and sufficient moldability and mechanical properties tend not to be obtained, which is not preferable. Examples of the copolymerization structural unit include a metaphenylene sulfide unit, an orthophenylene sulfide unit, p,
Examples thereof include p'-diphenylene ketone sulfide unit, -diphenylene sulfone sulfide unit, p, p'-biphenylene sulfide unit, p, p'-diphenylene ether sulfide unit, and 2,6-naphthalene sulfide unit. Particularly, as the PAS resin used in the present invention, a substantially linear high molecular weight PPS homopolymer whose repeating unit is paraphenylene sulfide, and paraphenylene sulfide as a main repeating unit, and 20 mol%
It is preferable to use a PPS copolymer mainly composed of the following metaphenylene sulfide as a main component. Further, as the polyarylene sulfide resin of the present invention, in addition to the above-described substantially linear polymer, a branched or crosslinked polyarylene polymerized by using a small amount of a monomer having three or more functional groups as a part of the monomer is used. Sulfide resins can also be used, and in particular, the above linear polymer and the above branched or crosslinked polymer (preferably 310 ° C., shear rate 200 sec).
^-1 , 5,000 to 25,000 poise) in small amount (1 to 1
25% by weight) mixed resin is particularly suitable because it suppresses the generation of burrs. Further, the PAS resin as the component (A) used in the present invention may be a polymer in which a relatively low molecular weight linear polymer is increased in melt viscosity by oxidative crosslinking or thermal crosslinking to improve molding processability. Good.

After the polymerization, the PAS resin used in the present invention is subjected to deionization treatment such as acid washing, hot water washing, organic solvent washing (or a combination thereof) to remove by-product impurities and the like and purify it. , Chlorine content and alkali metal content are each less than 500ppm, preferably 300ppm
The following are preferable.

Next, the aromatic phosphate represented by the above general formula (I), which is the characteristic component of the present invention, will be explained.

In the general formula (I), X is a bond, --CH _2- , --C (CH ₃ ) ₂ in order to obtain the effect of the present invention.
-, - S -, - SO 2 -, - O -, - CO- or -N
= A N-, as effective ones in formability at low temperatures with a small _{amount, -C (CH 3) 2 -} , - SO 2 - and particularly preferably.

The number average molecular weight m is preferably 1 <m <20, more preferably 2 ≦ m <10. When m is 1, the thermal stability at high temperatures such as during melting is insufficient, and m is 2
When it is 1 or more, the melt viscosity of the component (B) becomes high, and problems occur during the production of the composition such as kneading.

R ^{1 to} R ¹² are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. When the carbon number is too large, the affinity with PAS is poor and phase separation occurs on the molding surface. It is not preferable because peeling occurs. The blending amount of the aromatic phosphate as the component (B), which is a characteristic component of the present invention, is 0.1.
To 20 parts by weight, more preferably 0.2 to 10 parts by weight.
Parts by weight. If the blending amount is less than 0.1 part by weight, the effect is insufficient, and if the blending amount exceeds 20 parts by weight, the aromatic phosphate is not sufficiently dispersed in the polyarylene sulfide resin and a problem occurs on the molding surface and the like.

In order to remove decomposed gas, impurities, adhering water and the like from the above PAS resin composition, it is preferable to go through a process at 300 ° C. or higher during kneading. A product kneaded at 280 ° C. or lower generates volatile gas, decomposed gas, etc. during molding, which causes mold corrosion and deterioration of molding transferability.

Next, in the present invention, a molded product which is not necessarily an essential component but is excellent in performance such as mechanical strength, rigidity, heat resistance, dimensional stability (deformation resistance, warpage), and electrical properties. In order to obtain the above, it is preferable to add a filler as the component (C), and a fibrous, powdery or plate-like filler is used for this purpose. As the fibrous filler, glass fiber, asbestos fiber, carbon fiber, silica fiber, silica-alumina fiber, zirconia fiber, silicon nitride fiber, boron fiber, potassium titanate fiber, stainless steel, aluminum, titanium, copper, brass, etc. Inorganic fibrous substances such as metal fibrous substances of A particularly representative fibrous filler is glass fiber, carbon fiber, or potassium titanate fiber. It is also possible to use an organic fibrous substance having a high melting point such as aromatic polyamide, acrylic resin or fluororesin. On the other hand, as the particulate filler, carbon black, silica, quartz powder, glass beads, glass powder, calcium silicate, aluminum silicate, kaolin,
Silicates such as talc, clay, diatomaceous earth, wollastonite, oxides of metals such as iron oxide, titanium oxide, zinc oxide, alumina, carbonates of metals such as calcium carbonate and magnesium carbonate, calcium sulfate, sulfuric acid Sulfates of metals such as barium, other silicon carbide, boron nitride, silicon nitride,
Examples include various metal powders. Particularly representative ones are carbon black, silica, glass beads or glass powder, calcium carbonate, talc and the like. Examples of the plate-like filler include mica, glass flakes, various metal foils and the like. These inorganic fillers can be used alone or in combination of two or more. The combined use of fibrous fillers, especially glass fibers, carbon fibers or potassium titanate fibers with powdery and / or plate-shaped fillers has both mechanical strength, dimensional accuracy (warpage, deformation), and electrical properties. And a combination of glass fiber and calcium carbonate is particularly preferable.
When using these fillers, it is desirable to surface-treat them with a sizing agent or surface-treating agent, or to use them after converging. Examples of this treating agent are functional compounds such as epoxy compounds, isocyanate compounds, silane compounds and titanate compounds. The amount of the filler (C) added is the polyarylene sulfide resin 10
1 to 400 parts by weight per 0 parts by weight, preferably 1
0 to 300 parts by weight. If it is too small, the mechanical strength and rigidity will be reduced, and if it is too large, the fluidity will deteriorate and molding will be difficult, and the mechanical properties of the molded product will also be unfavorable.

The composition of the present invention is not particularly required, but the crystallization rate is further increased by further adding and using the crystal nucleating agent (D), and the effect of the present invention is further enhanced.
As the crystal nucleating agent used for this purpose, any of known organic nucleating agents and inorganic nucleating agents can be used. Examples of the inorganic substance include Zn powder, Al powder, graphite,
Simple substance such as carbon black, ZnO, MgO, Al
Metal oxides such as ₂ O ₃ , TiO ₂ , MnO ₂ , SiO ₂ and Fe ₃ O ₄ , nitrides such as boron nitride, Na ₂ C
O ₃ , CaCO ₃ , MgCO ₃ , CaSO ₄ , CaSi
Examples thereof include inorganic salts such as O ₃ , BaSO ₄ , and Ca ₃ (PO ₄ ) ₃ , silica, talc, kaolin, clay, and clay. As the organic substance, calcium oxalate, sodium oxalate, calcium benzoate, calcium phthalate, calcium tartrate, magnesium stearate, and other organic salts, heat-resistant polymers, crosslinked products of heat-resistant polymers, etc. are used. be able to. Particularly preferred are boron nitride; or clays such as talc, kaolin, clay and clay; polymer compounds having a crosslinked or branched structure. Here, the polymer compound having a crosslinked or branched structure is, for example, a polymer compound having a branched or crosslinked structure produced by polycondensation of a monomer having a functional group of three or more in a part of a monomer, or an existing polymer The substance may be any of those having a cross-linked structure or a branched structure, and the cross-linked P
It may be AS.

The above crystal nucleating agent contains an inorganic filler (C).
However, the amount of the (D) crystal nucleating agent used is 0.1 per 100 parts by weight of the polyarylene sulfide resin.
-10 parts by weight is sufficient, and preferably 0.1-5.
Parts by weight. If it is less than 0.1 parts by weight, the effect of increasing the crystallization rate is not sufficient.

In addition to the above-mentioned components, the composition of the present invention may be supplemented with a small amount of other thermoplastic resin in addition to the above components. Any other thermoplastic resin may be used as long as it is a thermoplastic resin that is stable at high temperatures. For example, an olefin resin such as polyethylene, polypropylene, or a copolymer obtained by modifying these, an aromatic polyester such as polyethylene terephthalate or polybutylene terephthalate, and an aromatic polyester consisting of diol or oxycarboxylic acid, nylon 66, nylon 6, Polyamide such as nylon 12, nylon 46, styrene resin such as polystyrene, AS, ABS, polyphenylene oxide, polycarbonate, polyalkyl acrylate, polyacetal, polysulfone, polyethersulfone, polyetherimide, polyetherketone, etc. it can. Further, these thermoplastic resins may be used as a mixture of two or more kinds. Furthermore, the composition of the present invention may contain stabilizers such as antioxidants and ultraviolet absorbers, antistatic agents, flame retardants, coloring agents such as dyes and pigments, and lubricating agents such as pentaerythritol ester, if necessary. Agents, alkoxysilanes, plasticizers such as alkyl mercaptans, and the like can be appropriately added depending on the required performance.

The PAS resin composition of the present invention can be prepared by the equipment and method generally used for preparing synthetic resin compositions. That is, necessary components can be mixed, melt-kneaded using a single-screw or twin-screw extruder, and extruded to obtain molding pellets. The necessary components can be used as a masterbatch by kneading with a part of PAS resin. Then, any method such as mixing and molding is possible.

[0025]

INDUSTRIAL APPLICABILITY The polyarylene sulfide resin composition of the present invention containing a specific amount of a specific aromatic carboxylic acid ester has a remarkable effect of promoting crystallization, and even when a mold at a relatively low temperature is used for molding. Molded products with sufficient crystallinity are obtained, molding workability (safety, etc.) is improved, and dimensional changes due to shrinkage due to irregular crystallization after molding are also improved, and extremely efficient molding processing is performed. It is possible to obtain a molded product having a good surface condition and the like.

[0026]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. Examples 1 to 12 and Comparative Examples 1 to 7 Deionized polyphenylene sulfide resin (Kureha Chemical Industry Co., Ltd., trade name "Fortron KPS" viscosity 2
Each component shown in Tables 1 and 2 was added to 8 Pa · s (measured at 310 ° C.) in the amounts shown in Tables 1 and 2, and premixed for 5 minutes with a Henschel mixer. In some cases, commercially available glass fiber (C) (made by Asahi Fiber Glass, diameter 10 μm, length 3
mm) was added in an amount shown in the table, mixed for 2 minutes with a blender, and the mixture was passed through an extruder (PCM30 manufactured by Ikegai Co., Ltd.) having a cylinder temperature shown in Tables 1 and 2 to form pellets of the polyphenylene sulfide resin composition. It was

Next, an injection molding machine (I manufactured by Toshiba Machine Co., Ltd.)
S50EP) with cylinder temperature 320 ° C and thickness 3m
m, size 50 mm x 70 mm flat plate test piece at 100 ° C
After being molded at the mold temperature of, and allowed to stand at room temperature for a certain period of time, the crystallinity was measured using a rad-rd X-ray diffractometer manufactured by Rigaku Denki Co., Ltd.

Further, the molded piece is kept at room temperature (23 ° C.) and humidity of 50.
% After adjusting for 24 hours in an atmosphere of
After annealing at 0 ° C. for 3 hours, the dimensions were measured, and the post-shrinkage rate was calculated. In addition, as the evaluation of the surface property, the surface gloss (surface) of the molded product was visually observed on the dumbbell portion of the tensile test piece which was not annealed, and was ranked as excellent, good, good or bad. Also, using a TGA device (TGA7 manufactured by Perkin Elmer Co., Ltd.) and using pellets after extrusion, 20
Heat loss (%) by increasing the temperature from 0 ℃ to 400 ℃ at 10 ℃ / min
Was measured.

The results are shown in Tables 1 and 2.

The components (B) and (D) used in this example are as follows.

The method for synthesizing the B component is not particularly limited.

B-1-1: Bisphenol A 200 parts by weight, phosphorus oxychloride 300 parts by weight, magnesium chloride 5
Charge 1 part by weight of the mixture into a flask and stir 120
React at ℃. The generated hydrogen chloride was collected with water. After the completion of the reaction, the pressure is reduced to 100 ° C. to recover the unreacted material, and then 370 parts by weight of cresol is added and the reaction is performed at 150 ° C.
Hydrogen chloride gas was collected with water, and after the reaction was completed, the pressure was reduced to recover unreacted cresol, which was washed with hot water and dried under reduced pressure. The obtained polyphosphate was GPC (the device was Waters, the solvent was N
MP) Flow rate 0.5 ml / min, UV (260 nm) detection was used, and the number average molecular weight was calculated from polystyrene conversion. B-1-2: Polyphosphate was obtained in the same manner as in B-1-1 except that bisphenol A was changed to 100 parts by weight. B-2: Polyphosphate was obtained in the same manner as in B-1-1 except that 370 parts by weight of cresol was changed to 320 parts by weight of phenol. B-3: Polyphosphate was obtained in the same manner as in B-1-1 except that 200 parts by weight of bisphenol A was changed to 230 parts by weight of bisphenol S. B-4: 230 parts by weight of resorcin, 400 phosphorus oxychloride
A mixture of 3 parts by weight of aluminum trichloride and 3 parts by weight of aluminum trichloride is charged into a flask and reacted at 90 ° C. with stirring. The generated hydrogen chloride was collected with water. After completion of the reaction, the pressure is reduced at 90 ° C. to recover unreacted materials, and then 400 parts by weight of cresol is added and the reaction is carried out at 150 ° C. Hydrogen chloride gas was collected with water, and after the reaction was completed, the pressure was reduced to recover unreacted cresol, which was washed with hot water and dried under reduced pressure. B-5: Polyphosphate was obtained in the same manner as in B-1-1 except that resorcin was changed to hydroquinone. B-6: tricresyl phosphate B-7: tri-2-ethylhexyl phosphate B-8: B-1 except that bisphenol A is changed to 20 parts by weight.
Polyphosphate was obtained in the same manner as in -1. D-1: Talc (Crown talc PP manufactured by Matsumura Sangyo) The structural formula and number average degree of polymerization m of the prepared aromatic phosphate are as follows.

[0033]

[Chemical 3]

[0034]

[Table 1]

[0035]

[Table 2]

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 4J002 CN011 CQ012 DA017 DA028                       DA037 DA038 DA097 DA098                       DA108 DA117 DC007 DE078                       DE107 DE108 DE117 DE118                       DE137 DE138 DE147 DE148                       DE187 DE237 DE238 DG047                       DG048 DG057 DG058 DH048                       DJ007 DJ017 DJ018 DJ027                       DJ037 DJ038 DJ047 DJ048                       DK007 DL007 EG038 EG058                       EG078 EG108 EW046 FA047                       FD017 FD208 GM00 GN00                       GQ00

Claims (5)

[Claims] 1. A (A) polyarylene sulfide resin 1
(B) represented by the following general formula (I) with respect to 100 parts by weight.
Add 0.1 to 20 parts by weight of aromatic phosphate to prepare 300
Polyarylene sulfide prepared by melt-kneading at ℃ or above
Resin composition. [Chemical 1] [In the formula, R¹~ R¹²Are each independently a hydrogen atom or
Or an alkyl group having 1 to 4 carbon atoms, X is a bond,
CH_Two-, -C (CH_Three)_Two-, -S-, -SO _Two-,
-O-, -CO- or -N = N-, n is 0 or
Is an integer of 1, m is the number average degree of polymerization, and 1 <m <
Twenty. ] 2. The polyarylene sulfide resin composition according to claim 1, wherein m of the component (B) is 2 or more. 3. The polyarylene sulfide resin composition according to claim 1, wherein X of the component (B) is —C (CH ₃ ) ₂ — or —SO ₂ —. 4. Further, 1 to 400 parts by weight of (C) an inorganic or organic filler or a mixture of both is added to 100 parts by weight of (A) polyarylene sulfide resin.
The polyarylene sulfide resin composition according to any one of 1 to 3. 5. The polyarylene according to claim 1, further comprising 0.1 to 10 parts by weight of the crystal nucleating agent (D) per 100 parts by weight of the (A) polyarylene sulfide resin. Sulfide resin composition.