Patent ID: 12252577

DESCRIPTION OF EMBODIMENTS

The present invention is hereinafter described in more detail with reference to examples; however, the present invention should not be limited to these examples.

Example 1

A glass-lined reaction vessel having an inner capacity of 300 L was charged with 130 kg of ion-exchanged water and 50 kg of a polyvinyl chloride resin having an average degree of polymerization of 1,000. They were stirred to disperse the polyvinyl chloride resin in water to prepare an aqueous suspension, and then the inside of the reaction vessel was heated to raise the temperature of the aqueous suspension to 70° C. Subsequently, the inside of the reaction vessel was depressurized to remove oxygen (oxygen content 100 ppm). Thereafter, with stirring, chlorine (oxygen content 50 ppm) was introduced at a partial pressure of chlorine of 0.04 MPa, and the suspension was irradiated with ultraviolet light having a wavelength of 365 nm at an irradiation intensity of 160 W using a high-pressure mercury lamp, thereby starting chlorination reaction.

Then, the chlorination temperature was kept at 70° C., the partial pressure of chlorine was kept at 0.04 MPa, and the average chlorine consumption rate was adjusted to 0.02 kg/PVC-kg-5 min. When the amount of added chlorine reached 9.5% by mass, the ultraviolet irradiation using the high-pressure mercury lamp and the chlorine gas supply were terminated, whereby chlorination was terminated.

Subsequently, unreacted chlorine was removed by nitrogen gas aeration, and the obtained chlorinated polyvinyl chloride resin slurry was neutralized with sodium hydroxide, washed with water, and dehydrated in a centrifuge (produced by Tanabe Tekkosho K.K., O-15 model) for three minutes.

After dehydration, 0.1 parts by mass (0.05 kg) of 2-ethylhexyl thioglycolate (produced by FUJIFILM Wako Pure Chemical Corporation) was added to 100 parts by mass (50 kg) of the chlorinated polyvinyl chloride resin at 200 g/min. This was followed by stationary drying at 90° C. Thus, a powdery, photo-chlorinated polyvinyl chloride resin (amount of added chlorine: 9.5% by mass) was obtained.

Comparative Example 1

A glass-lined reaction vessel having an inner capacity of 300 L was charged with 130 kg of ion-exchanged water and 50 kg of a polyvinyl chloride resin having an average degree of polymerization of 1,000. They were stirred to disperse the polyvinyl chloride resin in water to prepare an aqueous suspension, and then the inside of the reaction vessel was heated to raise the temperature of the aqueous suspension to 140° C. Subsequently, the inside of the reaction vessel was depressurized to remove oxygen (oxygen content 100 ppm). Thereafter, with stirring, chlorine (oxygen content 50 ppm) was introduced at a partial pressure of chlorine of 0.04 MPa, thereby starting thermal chlorination.

Then, the chlorination temperature was kept at 140° C. and the partial pressure of chlorine was kept at 0.4 MPa. After the amount of added chlorine reached 4.4% by mass, addition of a 200 ppm hydrogen peroxide solution was started at 15 ppm/Hr in terms of hydrogen peroxide relative to the polyvinyl chloride resin, and the average chlorine consumption rate was adjusted to 0.05 kg/PVC-kg-5 min. When the amount of added chlorine reached 9.5% by mass, the supply of hydrogen peroxide solution and chlorine gas was terminated, whereby chlorination was terminated.

Subsequently, unreacted chlorine was removed by nitrogen gas aeration, and the obtained chlorinated polyvinyl chloride resin slurry was neutralized with sodium hydroxide, washed with water, and dehydrated in a centrifuge (produced by Tanabe Tekkosho K.K., 0-15 model) for three minutes. This was followed by stationary drying at 90° C. Thus, a powdery, thermally chlorinated polyvinyl chloride resin (amount of added chlorine: 9.5% by mass) was obtained.

Examples 2 to 8 and Comparative Examples 2 and 3

A powdery chlorinated polyvinyl chloride resin was obtained as in Example 1 except that the average degree of polymerization and the charged amount of the polyvinyl chloride resin, the amount of the sulfur compound added, the reaction temperature, the average chlorine consumption rate, the drying temperature, and the drying time were changed as shown in Table 1.

(Evaluation)

The chlorinated polyvinyl chloride resins obtained in the examples and the comparative examples were evaluated as follows. Table 1 shows the results.

(1) Pulse NMR Measurement

The obtained powdery chlorinated polyvinyl chloride resin was placed in a glass sample tube having a diameter of 10 mm (produced by BRUKER, Product No. 1824511, 10 mm in diameter, 180 mm in length, flat bottom) so as to fall within the measurement range of a pulse NMR apparatus. The sample tube was set in the pulse NMR apparatus (produced by BRUKER, “the minispec mq20”) and subjected to measurement by the solid echo method at 30° C. under the conditions below, thereby obtaining a free induction decay curve of 1H spin-spin relaxation.

<Solid Echo Method>

Scans: 128 timesRecycle delay: 1 secAcquisition scale: 0.5 ms

The free induction decay curve was subjected to waveform separation into two curves derived from the A30component and the B30component. The waveform separation was performed by fitting using a Gaussian model. The percentages of the two components were determined from the curves derived from the components obtained in the measurement.

Using analysis software “TD-NMRA (Version 4.3, Rev. 0.8)” produced by BRUKER, a Gaussian-model fitting was applied to the A30component and B30component in conformity with the product manual.

The following equation was used in the fitting.

Y=A×exp⁡(-12×(tTA)2)+B×exp⁡(-12×(tTB)2)+C×exp⁡(-1TC)[Math.1]

In the formula, A represents the percentage of the A30component, B represents the percentage of the B30component, TArepresents the relaxation time of the A30component, TBrepresents the relaxation time of the B30component, and t represents time.

The A30component and the B30component are components defined in order of shorter relaxation time in pulse NMR measurement.

(Measurement after Heating at 200° C. for Five Minutes)

The obtained powdery chlorinated polyvinyl chloride resin in an amount of 300 g was placed in an aluminum tray, uniformly levelled, and then heated in an oven (produced by Toyo Seiki Seisaku-Sho, Ltd., CO—O2) at 200° C. for five minutes. Thereafter, the percentages of the two components (A30component and B30component), the relaxation time T5Aof the A30component, and the relaxation time T5Bof the B30component were determined by the same method as above.

(Measurement after Heating at 200° C. for 20 Minutes)

The obtained powdery chlorinated polyvinyl chloride resin in an amount of 300 g was placed in an aluminum tray, uniformly levelled, and then heated in an oven (produced by Toyo Seiki Seisaku-Sho, Ltd., CO—O2) at 200° C. for 20 minutes. Thereafter, the percentages of the two components (A30component and B30component), the relaxation time T20Aof the A30component, and the relaxation time T20Bof the B30component were determined by the same method as above.

The T5B/TBand the T5B/T20Bwere calculated from the obtained TB, T5B, and T20B.

(2) Measurement of Amount of Added Chlorine

The amount of added chlorine was measured for each of the obtained chlorinated polyvinyl chloride resins in conformity with JIS K 7229.

(3) Molecular Structure Analysis

The molecular structure of each of the obtained chlorinated polyvinyl chloride resins was analyzed in conformity with the NMR measurement method described in R. A. Komoroski, R. G. Parker, J. P. Shocker, Macromolecules, 1985, 18, 1257-1265 so as to determine the amount of the structural units (a) and (b) relative to the total number of moles of the structural units (a), (b), and (c).

The NMR measurement conditions were as follows.Apparatus: FT-NMRJEOLJNM-AL-300Measured nuclei: 13C (proton complete decoupling)Pulse width: 90°PD: 2.4 secSolvent: o-dichlorobenzene: deuterated benzene (C5D5)=3:1Sample concentration: about 20%Temperature: 110° C.Reference material: central signal for benzene set to 128 ppmNumber of scans: 20,000
(4) Measurement of Sulfur Content of Chlorinated Polyvinyl Chloride Resin

An amount of 300 parts by mass of THF was added to 10 parts by mass of each of the obtained chlorinated polyvinyl chloride resins, stirred for 24 hours for dissolution, followed by further stirring in a centrifuge (produced by Kokusan Co., Ltd., H-200NR) at 14,000 rpm for 1 hour to precipitate insoluble components. The insoluble components were filtered out, and to the filtrate was added 1,000 parts by mass of methanol to reprecipitate the resin. While the resin was washed with methanol, suction filtration was performed using an aspirator (produced by AS ONE Corporation, GAS-1N) to separate the resin from the filtrate. In this manner, a sulfur-bound resin was obtained. The resin was put in a vacuum drier (produced by Tokyo Rikakikai Co., Ltd., VOS-451SD) and dried at 80° C. for 24 hours. Combustion IC was performed to detect CS bonds. The obtained sample was weighed in a ceramic boat, and then burned in an automatic sample combustion device. The generated gas was captured in 10 mL of an absorber liquid. This absorber liquid was adjusted to 15 mL with ultrapure water, and subjected to IC quantitative analysis. After a linear approximation of a SO42−anion calibration curve by measurement of a reference substance, the sample was measured to quantify the sulfur content (mass ppm) of the chlorinated polyvinyl chloride resin.

The measurement conditions for the automatic combustion device are as follows.Device: AQF-2100H, produced by Mitsubishi Chemical AnalytechInlet temperature: 1,000° C.Outlet temperature: 1,100° C.Gas flow rate O2: 400 mL/minGas flow rate Ar: 200 mL/minAr water supply unit: 100 mL/minThe conditions for IC are as follows.Device: ICS-5000, produced by Thermo Fisher ScientificSeparation column: Dionex IonPac AS18-4 μm (2 mm×150 mm)Guard column: Dionex IonPac AG18-4 μm (2 mm×30 mm)Suppressor system: Dionex AERS-500 (external mode)Detector: conductivity detectorEluent: aqueous KOH solution (eluent generator EGC500)Eluent flow rate: 0.25 mL/minSample injection volume: 100 μL
(5) Adhesion Evaluation
(Preparation of Pipe)

An amount of 4.0 parts by mass of an impact resistance modifier was added to 100 parts by mass of each of the obtained chlorinated polyvinyl chloride resins. Then, 0.5 parts by mass of a thermal stabilizer was added and mixed. The impact resistance modifier used was Kane Ace B-564 (produced by Kaneka Corporation, methyl methacrylate-butadiene-styrene copolymer). The thermal stabilizer used was TVS #1380 (produced by Nitto Kasei Co., Ltd., organotin stabilizer).

Further, 1.5 parts by mass of a polyethylene lubricant (produced by Mitsui Chemicals, Inc., Hiwax 220MP) and 0.2 parts by mass of a fatty acid ester lubricant (produced by Emery Oleochemicals Japan Ltd., LOXIOL G-32) were added. They were then uniformly mixed in a super mixer to prepare a chlorinated polyvinyl chloride resin composition.

The obtained chlorinated polyvinyl chloride resin composition was supplied to a conical counter-rotating twin screw extruder (produced by Osada Seisakusho, SLM-50) having a diameter of 50 mm and formed into pipes at a resin temperature of 200° C., each pipe having an outer diameter of 26.7 mm and a wall thickness of 2.4 mm.

(Preparation of Joint)

An amount of 5.0 parts by mass of an impact resistance modifier was added to 100 parts by mass of a chlorinated polyvinyl chloride resin (produced by Sekisui Chemical Co., Ltd., HA-24KL). Further, 3.0 parts by mass of a thermal stabilizer was added and mixed. The impact resistance modifier used was Kane Ace M-511 (produced by Kaneka Corporation, methyl methacrylate-butadiene-styrene copolymer). The thermal stabilizer used was TVS #1380 (produced by Nitto Kasei Co., Ltd., organotin stabilizer).

Further, 2.0 parts by mass of a polyethylene lubricant (produced by Mitsui Chemicals, Inc., Hiwax 220MP) and 0.3 parts by mass of a fatty acid ester lubricant (produced by Emery Oleochemicals Japan Ltd., LOXIOL G-32) were added. They were then uniformly mixed in a super mixer to prepare a chlorinated polyvinyl chloride resin composition.

The obtained chlorinated polyvinyl chloride resin composition was supplied to a conical counter-rotating twin screw extruder (produced by Osada Seisakusho, OSC-30) having a diameter of 30 mm and formed into pellets at a resin temperature of 190° C. The obtained pellets were supplied to an injection molding machine (produced by JSW, J350ADS) and formed into a socket having an outer diameter of 34.7 mm and an inner diameter of 26.9 mm.

(Preparation of Assembled Sample)

Two of the obtained pipes were cut to a length of 20 cm and bonded to the two ends of the obtained joint using an adhesive (produced by IPS, WELD-ON 724). The workpiece was then left to stand at 23° C. for 14 days, and left to stand in an oven (produced by Toyo Seiki Seisaku-Sho, Ltd., CO—O2) at 82° C. for 2 days, whereby an assembled sample was obtained.

(Adhesion Evaluation)

The inside of the obtained assembled sample was filled with water. The test was started by pressurizing the pipes to a hoop stress of 15.93 MPa using a hydrostatic pressure resistance tester (produced by IPT, 1662-0021) in an atmosphere adjusted to 65° C. with an oven. The time until a disconnection occurred between the pipe and joint to which the adhesive was applied was measured.

The adhesion was evaluated as “o” (Good) when no disconnection was observed after 1,000 hours from the start of the test, and evaluated as “x” (Poor) when a disconnection occurred by 1,000 hours.

(6) Evaluation of Short-Term Bondability

(Preparation of pipe) and (Preparation of joint) were performed in the same manner as in “(5) Adhesion evaluation”. (Preparation of assembled sample) and (Evaluation of short-term bondability) were then performed as follows.

(Preparation of Assembled Sample)

Two of the obtained pipes were cut to a length of 20 cm and bonded to the two ends of the obtained joint using an adhesive (produced by IPS, WELD-ON 724). The workpiece was then left to stand at 23° C. for 24 hours, and left to stand in an oven (produced by Toyo Seiki Seisaku-Sho, Ltd., CO—O2) at 82° C. for two days, whereby an assembled sample was obtained.

(Evaluation of Short-Term Bondability)

The inside of the obtained assembled sample was filled with water. The test was started by pressurizing the pipes to an actual pressure of 3.6 MPa using a hot internal pressure creep tester (produced by YONEKURA MFG. Co., Ltd.) in an atmosphere adjusted to 82° C. with an oven. The time until a disconnection occurred between the pipe and joint to which the adhesive was applied was measured, and the short-term bondability was evaluated in accordance with the following criteria.o (Good): No disconnection was observed after six minutes after the start of the test.x (Poor): A disconnection occurred by six minutes after the start of the test.
(7) Molded Article Strength Evaluation

The presence or absence of cracks or fractures in the pipes and joint were determined after “(5) Adhesion evaluation”, and the molded article strength was evaluated in accordance with the following criteria.o (Good): No crack or fracture was observed after 1,000 hours.x (Poor): Cracks or fractures were observed by 1,000 hours.

TABLE 1ExampleComparative Example12345678123ProductionRawAverage degree of polymerization1000100010007001000100010001000100010001000methodmaterialCharged amountkg5050505050505050502550PVCWaterIon-exchanged waterkg130130130130130130130130130130130ChlorinationReaction temperature°C70608070707070701407070conditionsReaction pressureMpa0.040.040.040.040.040.040.040.040.400.040.04PVC + waterkg180180180180180180180180180155180Resin concentrationmass %2828282828282828281628(PVC/(PVC + water))*100Average chlorine consumption ratekg/pvc-kg ·0.020.0150.020.020.020.020.020.020.050.040.025 minUV wavelengthnm365365365365365365365365—365365200 ppm hydrogen peroxideppm/hr————————150—Amount of 2-ethylhexyl thio-parts by0.10.10.10.10.10.055.00.1000.1glycolate addedmassDrying temperature°C90909090909090120909050Drying timehr121212121212126121272ChlorinatedAmount of added chlorinemass %9.59.59.59.57.39.59.59.59.59.59.5polyvinylSulfur content of resinmass ppm1313121212111813003chlorideStructureStructural unit (a) —CH2—CHCl—mol %43.442.140.140.948.543.443.443.442.031.343.4resinStructural unit (b) —CH2—CCl2—mol %24.222.736.419.122.124.224.224.220.239.324.2Pulse NMRNotRelaxationTAms0.01140.01140.01140.01140.01140.01120.01140.01140.01140.01140.0114[30° C.heatedtimeTBms0.15310.15380.15440.14850.18090.19750.11870.15100.15780.15650.1780measure-PercentageA30%97.997.997.898.598.498.897.497.898.798.197.7ment]B30%2.12.12.21.51.61.22.62.21.31.92.3AfterRelaxationT5Ams0.01140.01140.01140.01140.01140.01120.01140.01140.01150.01130.0114heating attimeT5Bms0.12650.13980.12210.13160.15180.17740.09640.12060.15990.10920.1718200° C.PercentageA30%97.797.797.798.598.498.897.497.898.997.8980for 5B30%2.32.32.31.51.61.22.62.21.12.22.0minutesAfterRelaxationT20Ams0.01140.01140.01140.01140.01140.01120.01140.01140.01160.01140.1114heating attimeT20Bms0.13770.14610.14230.15830.16280.18930.11040.13070.15990.15490.1802200° C.PercentageA30%97.997.997.998.698.298.997.397.999.198098.1for 20B30%2.12.12.11.41.81.12.72.10.92.01.9minutesRelaxation time ratioT5B/TB%82.690.979.188.683.989.881.279.9101.369.896.5Relaxation time ratioT5B/T20B%91.995.785.883.193.293.787.392.3100.070.595.3EvaluationAdhesionOccurrence ofhr10001000100010001000100010001000401000800disconnectionRating○○○○○○○○x○xShort-term bondabilityDisconnectionmin66666666456timeRating○○○○○○○○xx○Molded article strengthRating○○○○○○○○○x○

INDUSTRIAL APPLICABILITY

The present invention can provide a chlorinated polyvinyl chloride resin that enables the production of a molded article that maintains high adhesion strength even when used in a form subjected to high pressure and is less susceptible to defects such as cracks due to insufficient strength, as well as a resin composition for molding and a molded article each including the chlorinated polyvinyl chloride resin.