Patent ID: 12187883

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 155 kg of ion-exchanged water and 70 kg of a polyvinyl chloride having an average degree of polymerization of 1,000. They were stirred to disperse the polyvinyl chloride 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, while stirring was performed with a stirring blade such that the vortex formed at the liquid-gas interface by stirring had a vortex volume of 2.3 L, chlorine (oxygen content 50 ppm) was introduced at a partial pressure of chlorine of 0.04 MPa. The suspension was then 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. At this time, the height of the stirring blade was adjusted such that the ratio of the distance from liquid surface to the stirring blade to the height of the liquid surface (Distance from liquid surface to stirring blade/Height of liquid surface) was 0.107. The ratio of the stirring blade diameter to the reaction vessel diameter (Stirring blade diameter/Reaction vessel diameter) was 0.54 (m/m).

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 10.6% 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, dehydrated, and then dried. Thus, a powdery, photo-chlorinated polyvinyl chloride resin (amount of added chlorine: 10.6% by mass) was obtained.

Example 2 to 18

Chlorinated polyvinyl chloride resins were obtained as in Example 1 except that the volume of the reaction vessel, the average degree of polymerization and the charge amount of the polyvinyl chloride, the amount of the ion-exchanged water, the vortex volume in stirring, the Distance from liquid surface to stirring blade/Height of liquid surface, and the average chlorine consumption rate were changed as shown in Tables 1 and 2.

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 having an average degree of polymerization of 1,000. They were stirred to disperse the polyvinyl chloride 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, while stirring was performed with a stirring blade such that the vortex formed at the liquid-gas interface by stirring had a vortex volume of 34.5 L, chlorine (oxygen content 50 ppm) was introduced at a partial pressure of chlorine of 0.40 MPa, thereby starting thermal chlorination. At this time, the height of the stirring blade was adjusted such that the ratio of the distance from liquid surface to the stirring blade to the height of the liquid surface (Distance from liquid surface to stirring blade/Height of liquid surface) was 0.950. The ratio of the stirring blade diameter to the reaction vessel diameter (Stirring blade diameter/Reaction vessel diameter) was 0.54 (m/m).

Then, the chlorination temperature was kept at 140° C. and the partial pressure of chlorine was kept at 0.40 MPa. After the amount of added chlorine reached 4.3% by mass, addition of a 200 ppm hydrogen peroxide solution was started at 50 ppm/hr in terms of hydrogen peroxide relative to the polyvinyl chloride, and the average chlorine consumption rate was adjusted to 0.04 kg/PVC-kg·5 min. Thereafter, when the amount of added chlorine reached 15.7% 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, dehydrated, and then dried. Thus, a powdery, thermally chlorinated polyvinyl chloride resin (amount of added chlorine: 15.7% by mass) was obtained.

Comparative Examples 2, 8, and 10

Chlorinated polyvinyl chloride resins were obtained as in Comparative Example 1 except that the reaction temperature, the vortex volume in stirring, the Distance from liquid surface to stirring blade/Height of liquid surface, and the average chlorine consumption rate were changed as shown in Table 2.

Comparative Examples 3 to 7 and 9

Chlorinated polyvinyl chloride resins were obtained as in Example 1 except that the charge amount of the vinyl chloride, the amount of the ion-exchanged water, the reaction temperature, the vortex volume in stirring, the Distance from liquid surface to stirring blade/Height of liquid surface, and the average chlorine consumption rate were changed as shown in Table 2.

(Evaluation)

The chlorinated polyvinyl chloride resins obtained in the examples and the comparative examples were evaluated as follows. Tables 1 and 2 show the results.

(1) Measurement of the 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.

(2) 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), (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
(3) Raman Spectroscopic Analysis
(3-1) Raman Imaging Measurement

Each of the obtained powdery chlorinated polyvinyl chloride resins was molded into a sheet shape using a vacuum press (produced by Meiki Co., Ltd., MHPC-VF) to prepare a resin sheet having a thickness of 0.5 mm. Here, for pressurization, the vacuum press was set at 180° C. The powdery chlorinated polyvinyl chloride resin was set in the vacuum press and the air was evacuated over one minute. At this time, evacuation needs to be performed from atmospheric pressure to 10 hPa within 30 seconds, because exposure to oxygen during heating causes oxidation or dehydrochlorination. Molding was then performed at a pressure of 3 MPa, a pressure-increase time of 30 seconds, and a dwell time of 1 minute, and the pressure was rapidly decreased to atmospheric pressure, followed by cooling. Thus, the resin sheet was prepared.

The obtained resin sheet was then cut using a microtome. The obtained cross section was subjected to Raman spectroscopic measurement using a micro-Raman spectrometer (produced by Nanophoton Corporation, RAMANtouch).

The Raman spectroscopic measurement was performed under the conditions of an objective lens magnification of 20× and an excitation wavelength of 532 nm in a region of 400 μm×100 μm at 1-μm intervals in the x direction and 2-μm intervals in the y direction. Raman spectra of 20,000 points of the cross section of the resin sheet were thus obtained.

The obtained Raman spectra were baseline-corrected by linear approximation using a baseline from 400 cm−1to 850 cm−1, and the peak intensity B observed in the range of 600 to 650 cm−1and the peak intensity A observed in the range of 660 to 700 cm−1were measured. Thereafter, the ratio (A/B) of the peak intensity A to the peak intensity B was calculated, and the average of the A/B was calculated.

(3-2) Raman Spectroscopy

Raman spectra of the obtained chlorinated polyvinyl chloride resins were measured using a micro-Raman spectrometer (produced by Thermo Fisher Scientific K.K., Almega XR). Here, the Raman spectra were measured for randomly collected 50 particles of each of the obtained powdery chlorinated polyvinyl chloride resins using a laser with a wavelength of 532 nm at an exposure time of 1 second and a scan number of 32. Raman spectroscopic analysis of particles themselves allows for obtaining the peak intensities of the particle surfaces. The wavenumbers of the Raman shifts were calibrated with the metal silicon peak at 520.5 cm−1.

The obtained Raman spectra were baseline-corrected by linear approximation using a baseline from 515 cm−1to 950 cm−1. The peak intensity B observed in the range of 600 to 650 cm−1(mainly 641 cm−1) and the peak intensity A observed in the range of 660 to 700 cm−1(mainly 697 cm−1) were measured. The ratio (A/B) of the peak intensity A to the peak intensity B was then calculated, and the average of the A/B of the 50 particles and the standard deviation of the A/B were calculated.

(4) Developed Interfacial Area Ratio (Sdr) (Production of Chlorinated Polyvinyl Chloride Resin Composition)

An amount of 5.5 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, 1.5 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, 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 uniformly mixed in a super mixer, whereby a chlorinated polyvinyl chloride resin composition was obtained.

(Production of Extrusion-Molded Article)

The obtained chlorinated polyvinyl chloride resin composition was fed into a twin-screw counter-rotating conical extruder with a diameter of 50 mm (produced by Osada Seisakusho, SLM-50) to prepare a sheet-shaped molded article with a thickness of 2 mm and a width of 80 mm at a resin temperature of 205° C., a back pressure of 130 kg/cm2, and an extrusion amount of 40 kg/hr.

(Sdr Measurement)

The Sdr value of a surface of the obtained molded article was measured using a 3D measurement system (produced by Keyence Corporation, VR-3100). Each Sdr value shown in Tables 1 and 2 is the average of five measurement regions.

Sdr is a ratio representing the degree of increase in the surface area of the measured region compared to the area of the measured region. A completely level surface has an Sdr of 0. A molded article having a low Sdr has excellent smoothness. Using such a molded article as, for example, a pipe-shaped molded article for plumbing or the like can reduce noise when water is running.

(5) Scorch Marks (Discoloration) of Molded Article

The surface state of the obtained molded article was visually examined and evaluated in accordance with the following criteria.o (Good): No scorch mark (discoloration) was observed.x (Poor): Scorch mark(s) (discoloration) was/were observed.
(6) Surface Shape (Unevenness)

The surface shape of the molded article was examined visually and by touch, and evaluated in accordance with the following criteria.o (Good): Neither the visual examination nor the touch examination found surface irregularities.Δ (Fair): The visual examination found no surface irregularities but the touch examination found surface irregularities.x (Poor) The visual examination found surface irregularities.
(7) Continuous Productivity

The obtained chlorinated polyvinyl chloride resin composition was fed into a twin-screw counter-rotating conical extruder with a diameter of 50 mm (produced by Osada Seisakusho, “SLM-50”) to prepare sheet-shaped molded articles with a thickness of 2 mm and a width of 80 mm at a resin temperature of 205° C., a back pressure of 130 kg/cm2, and an extrusion amount of 40 kg/hr. The time from the start of the molding to the occurrence of a scorch mark (discoloration) in the obtained molded article was measured, and the continuous productivity was evaluated.

A longer time before the occurrence of a scorch mark (discoloration) in the molded article indicates that the chlorinated polyvinyl chloride resin is less likely to contaminate the die surface and enables excellent continuous productivity when products are continuously produced by repeating similar operations for a long time.

(8) Surface Roughness (Sa)

A surface of the molded article obtained in “(4) Developed interfacial area ratio (Sdr)” was analyzed using a 3D measurement system (produced by Keyence Corporation, VR-3100) to measure the arithmetic surface roughness (Sa) defined in JIS B 0633-2001.

(9) Gloss

The glossiness of the molded article obtained in “(4) Developed interfacial area ratio (Sdr)” was measured using a glossmeter (produced by Nippon Denshoku Industries Co., Ltd., PG-1M) at an incident angle of 60° under the optical conditions specified in JIS 28741. The gloss was evaluated in accordance with the following criteria.o (Good): A glossiness of 3.5 or higherΔ (Fair): A glossiness of 2.5 or higher and lower than 3.5x (Poor) A glossiness of lower than 2.5

TABLE 1Examples1234567ProductionReactionVolumeL300300300300300300300methodvesselRaw materialAverage degree of1000100010001000100010001000PVCpolymerizationCharge amountkg70707070707070WaterIon-exchanged waterkg155155155155155155155ChlorinationReaction temperature° C.70707070707070conditionsReaction pressureMpa0.040.040.040.040.040.040.04PVC + waterkg225225225225225225225Vortex volume inL2.32.74.313.127.719.123.0stirring(Distance fromm/m0.1070.1310.2110.4210.5380.4440.463liquid surfaceto stirringblade)/Heightof liquidsurfaceVortex volume/L/kg0.0100.0120.0190.0580.1230.0850.102(PVC + water)(PVC + water)/kg/L0.7500.7500.7500.7500.7500.7500.750Reactionvessel volumeAveragekg/0.020.010.010.030.040.020.02chlorinepvc-kg ·consumption5 minrate200 ppmppm/hr———————hydrogenperoxideUV wavelengthnm365365365365365365365ChlorinatedAmount ofmass %10.64.78.111.513.110.410.6polyvinyladded chlorinechlorideStructureStructuralmol %36.172.651.631.321.537.936.9resinunit (a)—CH2—CHCl—Structuralmol %24.510.719.024.531.324.624.9unit (b)—CH2—CCl2—Structuralmol %39.416.729.444.247.237.538.2unit (c)—CHCl—CHCl—RamanPeakAaverage1.2000.7601.2121.7121.8201.3341.345spectroscopicintensityStandard0.1270.1020.1250.1600.1810.1030.108analysisA/Bdeviation(Peak average1.5561.0791.5652.1122.2451.6551.673of A/B) +(Standarddeviation)1/2MoldedSdr0.00030.0010.00050.00070.00150.00070.0005articleScorch mark∘∘∘∘∘∘∘(discoloration)Surface shape∘∘∘∘∘∘∘(unevenness)Continuous12.05.07.27.24.25.011.5productivity (hr)Sa1.93.02.32.63.82.62.3GlossMeasured3.93.74.24.13.93.83.9valueEvaluation∘∘∘∘∘∘∘Examples891011121314ProductionReactionVolumeL300300300300300300300methodvesselRaw materialAverage degree of10001000350450190021001000PVCpolymerizationCharge amountkg70707070707070WaterIon-exchanged waterkg155155155155155155155ChlorinationReaction temperature° C.70707070707070conditionsReaction pressureMpa0.040.040.040.040.040.040.04PVC + waterkg225225225225225225225Vortex volume inL18.522.116.911.025.224.331.5stirring(Distance fromm/m0.0400.4560.4380.3990.4890.4770.673liquid surfaceto stirringblade)/Heightof liquidsurfaceVortex volume/L/kg0.0820.0980.0750.0490.1120.1080.140(PVC + water)(PVC + water)/kg/L0.7500.7500.7500.7500.7500.7500.750Reactionvessel volumeAveragekg/0.020.020.020.030.030.020.02chlorinepvc-kg ·consumption5 minrate200 ppmppm/hr———————hydrogenperoxideUV wavelengthnm365365365365365365365ChlorinatedAmount ofmass %10.710.410.411.210.911.210.9polyvinyladded chlorinechlorideStructureStructuralmol %36.237.537.633.135.033.034.5resinunit (a)—CH2—CHCl—Structuralmol %25.622.123.426.419.026.428.4unit (b)—CH2—CCl2—Structuralmol %38.240.439.040.546.040.637.1unit (c)—CHCl—CHCl—RamanPeakAaverage1.3501.3340.7950.8831.4471.8201.760spectroscopicintensityStandard0.1850.1950.1480.1570.1530.1570.153analysisA/Bdeviation(Peak average1.7801.7761.1791.2781.8382.2162.151of A/B) +(Standarddeviation)1/2MoldedSdr0.00090.0020.00030.00050.00150.0020.0005articleScorch mark∘∘∘∘∘∘∘(discoloration)Surface shape∘∘∘∘∘∘∘(unevenness)Continuous10.84.94.75.93.53.110.5productivity (hr)Sa2.94.52.02.33.84.52.3GlossMeasured3.73.74.44.34.24.13.7valueEvaluation∘∘∘∘∘∘∘

TABLE 2ExamplesComparative Examples15161718123ProductionReaction vesselVolumeL200600300300300300300methodRaw materialAverage degree of1000100010001000100010001000PVCpolymerizationCharge amountkg41.71256075505070WaterIon-exchanged waterkg108.3270156195130130155ChlorinationReaction temperature° C.707070701408080conditionsReaction pressureMpa0.040.040.040.040.400.400.04PVC + waterkg150450216270180180225Vortex volume inL12.335.119.224.834.50.943.2stirring(Distance fromm/m0.4420.4400.4460.4490.9500.0320.963liquid surfaceto stirringblade)/Height ofliquid surfaceVortex volume/L/kg0.0820.0780.0890.0920.1920.0050.192(PVC + water)(PVC + water)/kg/L0.7500.7500.7200.9000.6000.6000.750Reaction vesselvolumeAverage chlorinekg/0.020.020.020.030.040.010.02consumption ratepvc-kg ·5 min200 ppm hydrogenppm/hr————5050—peroxideUV wavelengthnm365365365365——365ChlorinatedAmount of addedmass %10.910.25.210.815.72.215.4polyvinylchlorinechlorideStructureStructuralmol %35.139.269.835.66.490.17.0resinunit (a)—CH2—CHCl—Structuralmol %26.024.19.725.438.23.972.2unit (b)—CH2—CCl2—Structuralmol %39.036.720.539.055.36.020.8unit (c)—CHC—CHCl—RamanPeakAaverage1.3611.3231.0571.7532.1400.4802.012spectroscopicintensityStandard0.1530.1450.1040.1520.0710.0410.215analysisA/Bdeviation(Peak average1.7521.7051.3802.1432.4060.6822.475of A/B) + (Standarddeviation)1/2MoldedSdr0.00050.00050.00070.00050.01310.00010.015articleScorch mark∘∘∘∘xxx(discoloration)Surface shape∘∘∘∘x∘x(unevenness)Continuous7.57.910.810.22.60.62.5productivity (hr)Sa2.32.32.62.321.31.724.2GlossMeasured3.73.93.73.92.14.03.6valueEvaluation∘∘∘∘x∘∘Comparative Examples45678910ProductionReaction vesselVolumeL300300300300300300300methodRaw materialAverage degree of1000100010004006006001200PVCpolymerizationCharge amountkg7054.280.837.5806060.8WaterIon-exchanged waterkg155140.8210.297.5208156158.2ChlorinationReaction temperature° C.7070707510070110conditionsReaction pressureMpa0.040.040.040.040.450.040.5PVC + waterkg225195291135288216219Vortex volume inL33.817.634.91.138.91.135.5stirring(Distance fromm/m0.7950.4470.5220.0770.6000.0320.949liquid surfaceto stirringblade)/Height ofliquid surfaceVortex volume/L/kg0.1500.0900.1200.0080.1350.0050.162(PVC + water)(PVC + water)/kg/L0.7500.6500.9700.4500.9600.7200.730Reaction vesselvolumeAverage chlorinekg/0.030.050.040.020.050.020.03consumption ratepvc-kg ·5 min200 ppm hydrogenppm/hr————50—50peroxideUV wavelengthnm365365365365—365—ChlorinatedAmount of addedmass %3.22.915.64.913.43.115.6polyvinylchlorinechlorideStructureStructuralmol %82.083.56.371.519.582.56.3resinunit (a)—CH2—CHCl—Structuralmol %9.98.959.218.533.39.956.2unit (b)—CH2—CCl2—Structuralmol %8.17.634.510.047.27.637.5unit (c)—CHC—CHCl—RamanPeakAaverage0.4700.4892.0340.7901.8900.4902.100spectroscopicintensityStandard0.0950.0940.2180.2050.0400.1700.105analysisA/Bdeviation(Peak average0.7780.7962.5011.2432.0900.9022.424of A/B) + (Standarddeviation)1/2MoldedSdr0.0120.0080.0090.01050.0120.01020.0125articleScorch markxxxx∘x∘(discoloration)Surface shapexxxxxxx(unevenness)Continuous2.52.61.21.22.80.93.5productivity (hr)Sa19.613.615.117.419.616.920.4GlossMeasured3.63.63.63.72.23.51.9valueEvaluation∘∘∘∘x∘x

INDUSTRIAL APPLICABILITY

The present invention can provide a chlorinated polyvinyl chloride resin that enables a molded article to have both processability and unevenness-preventing properties and also high gloss.