HEAT-TREATED FINE POLYARYLENE SULFIDE POWDER AND MANUFACTURING METHOD FOR MANUFACTURING SAME

Abstract

A heat treated fine polyarylene sulfide powder. (i) The heat treated fine polyarylene sulfide powder is manufactured from separation liquid. (ii) The heat treated fine polyarylene sulfide powder is obtained by subjecting the separation liquid to solid-liquid separation to obtain a raw material fine powder polyarylene sulfide. Thereafter the raw material fine powder polyarylene sulfide is subjected to pre-heat treatment and heat treatment. (iii) The heat treated fine polyarylene sulfide powder has an average particle size of from 1 to 80 m. (iv) The heat treated fine polyarylene sulfide powder has a melt viscosity of 1 Pa.Math.s or greater. (v) A generated gas amount of the heat treated fine polyarylene sulfide is 10 ppm or less.

Claims

1. (canceled)

2. (canceled)

3. A manufacturing method for manufacturing a heat treated fine polyarylene sulfide powder, the manufacturing method comprising the following steps: (a) a polymerization step, wherein at least one sulfur source selected from the group consisting of an alkali metal sulfide and an alkali metal hydrosulfide and a dihalo aromatic compound are subjected to a polymerization reaction in organic amide solvent; (b) a separation step, wherein a reaction solution containing produced granular polyarylene sulfide is separated into the granular polyarylene sulfide and a separation liquid through solid-liquid separation; (c) a solid-liquid separation step, wherein the separation liquid is subjected to solid-liquid separation to obtain a raw material fine powder polyarylene sulfide; (d) a pre-heat treatment step, wherein the raw material fine powder polyarylene sulfide is preheated at from 50 to 150 C. to obtain a pre-heat treated raw material fine powder polyarylene sulfide; and (e) a heat treatment step, wherein the pre-heat treated raw material fine powder polyarylene sulfide is heated at from 160 to 260 C. to obtain a heat treated fine powder polyarylene sulfide.

4. The manufacturing method according to claim 3, wherein the separation step is implemented using at least one screen with an aperture size in a range of 75 to 180 m.

5. The manufacturing method according to claim 1, wherein the pre-heat treatment step is implemented under reduced pressure.

6. (canceled)

7. The manufacturing method according to claim 1, further comprising a washing step prior to the pre-heat treatment step, wherein the raw material fine powder polyarylene sulfide is washed using water, alcohol, acetone, acetic acid, acetic acid salt, hydrochloric acid, or a mixture thereof

8. The manufacturing method according to claim 1, wherein the heat treatment step is implemented in an inert gas atmosphere.

9. The manufacturing method according to claim 1, further comprising a pre-solid-liquid separation step and a byproduct alkali metal salt removal step prior to the solid-liquid separation step.

10. (canceled)

11. (canceled)

12. (canceled)

Description

EXAMPLES

[0191] Below, the present invention is described in more detail using Manufacturing Examples, Working Examples, and Comparative Examples. The present invention is not limited by the following examples. In the following Working Examples and Comparative Examples, unless otherwise stated, parts and % are by mass.

[0192] Below, the measurement methods for each physical property are described.

[0193] (1) The Granular PAS Recovery Ratio and Fine PAS Powder Product Rate (mass %)

[0194] The granular PAS recovery ratio and heat treated fine PAS powder product rate are calculated as the entire amount of PAS obtained, based on the mass (theoretical amount) of PAS when it is assumed that all the effective sulfur component within the charged sulfur source present in the reaction vessel after the dehydration step has been converted into PAS.

[0195] In other words, the granular PAS recovery ratio is the mass of recovered granular PAS/mass of PAS (theoretical amount).

[0196] The product rate of heat treated fine PAS powder is the mass of productized heat treated fine PAS powder/mass of PAS (theoretical amount).

[0197] (2) Granular PAS Average Particle Size

[0198] The average particle size of the recovered granular PAS was measured using sieves of mesh #7 (aperture size 2,800 m), #12 (aperture size 1,410 m), #16 (aperture size 1,000 m), #24 (aperture size 710 m), #32 (aperture size 500 m), #60 (aperture size 250 m), #100 (aperture size 150 m), #145 (aperture size 105 m), and #200 (aperture size 75 m).

[0199] (3) Raw Material Fine PAS Powder and Heat Treated fine PAS Powder Average Particle Size

[0200] The average particle size of raw material fine PAS powder and heat treated fine PAS powder were measured using a laser diffraction particles size distribution measuring device (SALD manufactured by Shimadzu Corporation).

[0201] (4) Weight Average Molecular Weight, and Peak Top Molecular Weight

[0202] The weight average molecular weight (Mw) of granular PAS, raw material fine PAS powder and heat treated fine PAS powder were measured using a high temperature gel permeation chromatograph (GPC) SSC-7101, manufactured by Senshu Scientific, Co., Ltd., under the following conditions. Weight average molecular weight, and peak top molecular weight are calculated using polystyrene as the standard.

[0203] Solvent: 1-chloronaphthalene,

[0204] Temperature: 210 C.,

[0205] Detector: UV detector (360 nm),

[0206] Quantity of sample inserted: 200 l (concentration: 0.1 mass %),

[0207] Flow rate: 0.7 mL/min,

[0208] Standard polystyrene: Five types of standards polystyrene, 616,000, 113,000, 26,000, 8,200, and 600.

[0209] (5) Amount of Generated Gas

[0210] Generated gas was measured using the detector tube method.

[0211] Gas sampling set GASTEC GV-100S 1 minute retention

[0212] Gas detector tube

[0213] 4.0 ppm or less: GASTEC No. 4LT

[0214] from 4 to 40 ppm: GASTEC No. 4LK

[0215] from 40 to 240 ppm: GASTEC No. 4L

[0216] Measurement Method

[0217] The dry block bath was heated to 280 C. (actual temperature) and the test tube set in place. Once it was confirmed that the test tube had heated to 280 C., a sample weighing 0.1000 g was inserted. After insertion, the test tube was quickly closed with a stopper with a gas insert tube and a gas output tube, and nitrogen gas was introduced at a flow rate of 16.67 mL/min. The gas discharged was collected in a Tedlar bag (1 L) for one hour, and measurement was performed using the abovementioned measuring device.

[0218] (6) Melt Viscosity

[0219] Approximately 20 g of dry product granular PAS, raw material fine PAS powder, and heat treated fine PAS powder was used to measure melt viscosity, using a Capillograph 1-C manufactured by Toyo Seiki Seisaku-sho, Ltd. A flat die having a diameter of 1 mm and length of 10 mm was used as the capillary, with the temperature set at 310 C. The abovementioned PAS specimens were inserted in the device and retained for 5 minutes, after which melt viscosity was measured at shear rate 1,216 sec.sup.1.

PRODUCTION EXAMPLE

[0220] (Dehydration Step)

[0221] A 20 liter autoclave was used to hold 6,001 g NMP, 2,000 g sodium hydrosulfide aqueous solution (NaSH: purity 62 mass %), and 1,171 g sodium hydroxide (NaOH: purity 74.0 mass %).

[0222] After the inside of the autoclave was purged with nitrogen gas, it was stirred by a stirrer for 4 hours at a rotation speed of 250 rpm, while being heated gradually to 200 C., after which 1,014 g water (H.sub.2O), 763 g NMP, and 12 g hydrogen sulfide (H.sub.2S) were distilled away.

[0223] (Polymerization Step)

[0224] After the dehydration step the contents of the autoclave were cooled to 150 C., and 3.360 g pDCB, 2.707 g NMP, 19 g sodium hydroxide, and 167 g water were added, before heating to 220 C. and leaving to react for 5 hours to implement the first polymerization.

[0225] The ratio of NMP/charged sulfur source (hereinafter referred to as preparation S) within the vessel (g/mol) was 375, pDCB/preparation S (mol/mol) was 1.050, and H.sub.2O/preparation S (mol/mol) was 1.50.

[0226] The pDCB conversion ratio after the first polymerization was 92%.

[0227] After the first polymerization was completed, the stir rotation speed was raised to 400 rpm, and 443 g ion-exchanged water was added to the autoclave while stirring. H.sub.2O/preparation S (mol/mol) was 2.63. After the pressurized addition of ion-exchanged water, the temperature was raised to 255 C., and after 4 hours of reaction, the second polymerization was implemented.

[0228] (Separation Step)

[0229] After the second polymerization, the mixture was cooled to around room temperature, and the contents sieved using a screen with aperture size 150 m (100 mesh), to obtain a wet cake of granular PPS on the sieve, and separation liquid below the sieve.

[0230] Subsequently, the granular PPS on the sieve was subjected to typical washing, drying and other recovery steps, and particle PPS for product was obtained with a recovery ratio of 88 mass %. The average particle size was 360 m, the weight average molecular weight was 42,800, and the peak top molecular weight was 51,200.

Working Example 1

[0231] The separation liquid obtained from under the sieve in the separation step in Working Example 1 was processed as below.

[0232] The separation liquid was filtered, to implement pre-solid-liquid separation and obtain raw material fine PPS powder and filtration liquid (pre-solid-liquid separation step). The raw material fine PPS powder was washed twice in acetone, and then filtered once again to separate it into raw material fine PPS powder and filtration liquid. The raw material fine PPS powder was dried using a dryer at 140 C. Next, washing was implemented using distilled water (byproduct alkali metal salt removal step), and solid-liquid separation was implemented using a filter press, obtaining a wet cake (solid-liquid separation step). Part of the wet cake obtained after solid-liquid separation was dried for 24 hours at room temperature, before its average particle size, weight average molecular weight, peak top molecular weight, and melt viscosity were measured.

[0233] Furthermore, the wet cake was washed (washing step). The washed wet cake was filtered using a filtration device. Next, the wet cake was dried for 3 hours at 60 C. under reduced pressure (90 KPa) as a pre-heat treatment step.

[0234] Next, the pre-heat treated raw material fine PPS powder that was pre-heat treated in the pre-heat treatment was heat treated for 3 hours at 220 C. in a nitrogen atmosphere as the heat treatment step, after which recovery was implemented to obtain a heat treated fine PPS powder. The results are shown in Table 1.

Working Example 2

[0235] This was prepared in the same way as Working Example 1, except that the pre-heat treatment step was carried out under regular pressure conditions, at 140 C. for 3 hours. The results are shown in Table 1.

Working Example 3

[0236] This was prepared in the same way as Working Example 1, except that the pre-heat treatment step was carried out under regular pressure conditions, at 120 C. for 3 hours. The results are shown in Table 1.

Comparative Example 1

[0237] This was prepared in the same way as Working Example 1, except that no pre-heat treatment step was carried out, and a heat treatment step was carried out under regular pressure conditions, in a nitrogen atmosphere, at 220 C. for 6 hours. The results are shown in Table 1.

Comparative Example 2

[0238] This was prepared in the same way as Working Example 1, except that the pre-heat treatment step was carried out under regular pressure conditions at 120 C. for 6 hours, and no heat treatment step was carried out. The results are shown in Table 1.

TABLE-US-00001 TABLE 1 Working Working Working Comparative Comparative Example 1 Example 2 Example 3 Example 1 Example 2 Granular PPS Weight average 42,800 42,800 42,800 42,800 42,800 (100 mesh on) molecular weight Peak top molecular 51,200 51,200 51,200 51,200 51,200 weight Melt viscosity (Pa .Math. s) 30 30 30 30 30 Average particle 360 360 360 360 360 size (m) Recovery ratio (%) 88 88 88 88 88 Raw material Weight average 27,000 27,000 27,000 27,000 27,000 fine PPS molecular weight powder Peak top molecular 44,500 44,500 44,500 44,500 44,500 weight Average particle 10-15 10-15 10-15 10-15 10-15 size (m) Melt viscosity (Pa .Math. s) 2 2 2 2 2 Pre-heat Conditions 60 C. 140 C. 120 C. None 120 C. treatment step 3 hours 3 hours 3 hours 6 hours Reduced Regular Regular Regular pressure pressure pressure pressure Heat Conditions 220 C. 220 C. 220 C. 220 C. None treatment step 3 hours 3 hours 3 hours 6 hours Nitrogen Nitrogen Nitrogen Nitrogen atmosphere atmosphere atmosphere atmosphere Heat treated Average particle 10-15 10-15 10-15 10-15 10-15 fine PPS size (m) powder Weight average 41,800 42,500 41,000 40,100 27,800 molecular weight Peak top molecular 41,500 41,900 42,700 43,000 45,000 weight Melt viscosity (Pa .Math. s) 20 23 22 14 3 Amount of 2 2 2 12 68 generated gas (ppm) Product Rate Product Rate 4.8 5.1 5.1 5.2 5.1 (mass %)

Working Example 4

[0239] A mixture of 60 mass % PPS, comprising 95 mass % of the granular PPS manufactured in the Production example and 5 mass % of the heat treated fine PPS powder manufactured in Working Example 1, along with 39.8 mass % fibrous filler (13 m glass fiber) and 0.2 mass % mold releasing agent was combined for 5 minutes, after which it was melted and kneaded in a dual screw extruder with a cylinder temperature of 320 C. to form pellets. While the melted and kneaded pellets were being formed, no bad odor such as that seen in Comparative Example 3 described below was noted. 10 g of the pellets formed were measured into a 10 mm diameter test tube, and an SKD 11 metal piece measuring 8 mm square (2 mm thick) was placed on top of the accumulated pellets, before closing the tube with a silicone stopper. Subsequently, the test tube was placed in an aluminum block bath, and heated at 340 C. for 4 hours. When the volatile substance adhered to the metal piece was observed prior to and after the experiment, it looked the same as when no heat treated fine PPS powder had been added.

Comparative Example 3

[0240] Except for using the fine PPS powder that was subjected only to pre-heat treatment in Comparative Example 2 in place of the heat treated fine PPS powder, the same process was implemented as that in Working Example 4. While pellets were being formed by melting and kneading, a terrible smell occurred. There was also a significant adhesion of volatile substances to the metal piece.

[0241] Observations

[0242] In Comparative Example 1, no pre-heat treatment was carried out, and heat treatment was implemented immediately in a nitrogen atmosphere at 220 C. for 6 hours. Since no pre-heat treatment was implemented, a significant quantity of gas was generated, and melt viscosity was low. Furthermore, despite the fact that the heat treatment time was twice as long as that in Working Examples, the melt viscosity was lower than that anticipated from the Working Examples. This suggests that if there is a large quantity of generated gas, melt viscosity is low.

[0243] In Comparative Example 2, pre-heat treatment was implemented at 120 C. for 6 hours, but no heat treatment was implemented. For that reason, there was a highly significant amount of generated gas from the pre-heat treated raw material fine PPS powder, while the weight average molecular weight and melt viscosity were low. In this case, despite the fact that the pre-heat treatment was implemented for a long time, no effect was noted.

[0244] Working Examples 1 to 3 were pre-heat treated, respectively, at 60 C. for 3 hours under reduced pressure; at 140 C. for 3 hours under regular pressure; and at 120 C. for 3 hours under regular pressure, after which each of them was heat treated at 220 C. for 3 hours. Because pre-heat treatment and then heat treatment were implemented in a state where the fine PPS powder thermal history had been accurately adjusted, impurities are well volatilized and there was little gas generated; furthermore, the heat treatment resulted in weight average molecular weight, melt viscosity and peak top molecular weight that were sufficient for practical use.

[0245] Furthermore, when the fine PPS powder from Comparative Example 3 and Comparative Example 2, which had not been subjected to heat treatment, were used in melted and kneaded pellets, a terrible smell occurred, and a significant quantity of volatile substances adhered to the metal piece. In comparison, in Working Example 4, when heat treated fine PPS powder was used as part of the compound, nothing adhered to the metal piece, indicating a high level of practical applicability.

INDUSTRIAL APPLICABILITY

[0246] The heat treated fine PAS powder of the present invention can be reused as one component in a compound. The heat treated fine PAS powder of the present invention is manufactured from raw material fine PAS powder within the separation liquid that was conventionally disposed and not used, and it is extremely significant that it can now be reused without contaminating the work environment.