MOLDING RESIN COMPOSITION AND MOLDED ARTICLE

Abstract

The present invention aims to provide a resin composition for molding that makes it possible to achieve excellent continuous productivity and to produce a molded article having high surface smoothness, capable of reducing defective molding, less likely to crack during use, and also having excellent shock resistance. The present invention also aims to provide a molded article including the resin composition for molding. Provided is a resin composition for molding, containing: a chlorinated polyvinyl chloride resin; and a melt additive, the resin composition containing three components including a A.sub.100 component, a B.sub.100 component, and a C.sub.100 component, and having a percentage of the C.sub.100 component [C.sub.100 component/(A.sub.100 component+B.sub.100 component+C.sub.100 component)] of 30% or less, the three components being identified by measuring the resin composition by a solid echo method using pulse NMR at 100° C. to give a free induction decay curve of .sup.1H spin-spin relaxation, and subjecting the free induction decay curve to waveform separation into three curves derived from the A.sub.100 component, the B.sub.100 component, and the C.sub.100 component in order of shorter relaxation time using the least square method.

Claims

1. A resin composition for molding, comprising: a chlorinated polyvinyl chloride resin; and a melt additive, the resin composition containing three components including a A.sub.100 component, a Brno component, and a C.sub.100 component, and having a percentage of the C.sub.100 component [C.sub.100 component/(A.sub.100 component+B.sub.100 component+C.sub.100 component)] of 30% or less, the three components being identified by measuring the resin composition by a solid echo method using pulse NMR at 100° C. to give a free induction decay curve of .sup.1H spin-spin relaxation, and subjecting the free induction decay curve to waveform separation into three curves derived from the A.sub.100 component, the B.sub.100 component, and the C.sub.100 component in order of shorter relaxation time using the least square method.

2. The resin composition for molding according to claim 1, wherein the melt additive has an area ratio of a peak B observed in a range of 0.6 to 1.0 ppm to a peak A observed in a range of 9.5 to 10 ppm (Area of peak B/Area of peak A) of 1 to 1,000 when a .sup.1H NMR spectrum is measured by solution NMR.

3. A molded article molded from the resin composition for molding according to claim 1.

4. A molded article molded from the resin composition for molding according to claim 2.

Description

DESCRIPTION OF EMBODIMENTS

[0145] The present invention is hereinafter described in more detail with reference to examples; however, the present invention should not be limited to the examples.

(Preparation of Chlorinated Polyvinyl Chloride Resin A)

[0146] A glass-lined reaction vessel having an inner capacity of 300 L was charged with 130 kg of deionized 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. Subsequently, the inside of the reaction vessel was depressurized to remove oxygen (oxygen content 100 ppm). Thereafter, while stirring was performed such that the vortex formed at the liquid-gas interface by stirring had a vortex volume of 2.2 L, chlorine (oxygen content 50 ppm) was introduced at a partial pressure of chlorine of 0.04 MPa. After three hours, heating was started, and irradiation of ultraviolet light having a wavelength of 365 nm was performed at an irradiation intensity of 350 W with a high-pressure mercury lamp, thereby starting chlorination reaction.

[0147] Then, the chlorination temperature was kept at 70° C. and the partial pressure of chlorine was kept at 0.04 MPa. 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 irradiation of ultraviolet light with the high-pressure mercury lamp and the supply of chlorine gas were terminated, whereby chlorination was terminated.

[0148] Next, unreacted chlorine was removed by nitrogen gas aeration, followed by washing with water, dehydration, and drying. Accordingly, a powdery chlorinated polyvinyl chloride resin (amount of added chlorine: 10.6% by mass) was obtained.

(Preparation of Chlorinated Polyvinyl Chloride Resin B)

[0149] A glass-lined reaction vessel having an inner capacity of 300 L was charged with 130 kg of deionized water and 50 kg of a polyvinyl chloride resin having an average degree of polymerization of 700. They were stirred to disperse the polyvinyl chloride resin in water to prepare an aqueous suspension. Subsequently, the inside of the reaction vessel was depressurized to remove oxygen (oxygen content 100 ppm). Thereafter, while stirring was performed such that the vortex formed at the liquid-gas interface by stirring had a vortex volume of 2.2 L, chlorine (oxygen content 50 ppm) was introduced at a partial pressure of chlorine of 0.04 MPa. After three hours, heating was started, and irradiation of ultraviolet light having a wavelength of 365 nm was performed at an irradiation intensity of 350 W with a high-pressure mercury lamp, thereby starting chlorination reaction.

[0150] Then, the chlorination temperature was kept at 70° C. and the partial pressure of chlorine was kept at 0.04 NPa. The average chlorine consumption rate was adjusted to 0.02 kg/PVC-kg.Math.5 min. When the amount of added chlorine reached 10.6% by mass, the irradiation of ultraviolet light with the high-pressure mercury lamp and the supply of chlorine gas were terminated, whereby chlorination was terminated.

[0151] Next, unreacted chlorine was removed by nitrogen gas aeration, followed by washing with water, dehydration, and drying. Accordingly, a powdery chlorinated polyvinyl chloride resin (amount of added chlorine: 10.6% by mass) was obtained.

(Preparation of Chlorinated Polyvinyl Chloride Resin C)

[0152] A glass-lined reaction vessel having an inner capacity of 300 L was charged with 130 kg of deionized 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. Subsequently, the inside of the reaction vessel was depressurized to remove oxygen (oxygen content 100 ppm). Thereafter, while stirring was performed such that the vortex formed at the liquid-gas interface by stirring had a vortex volume of 2.2 L, chlorine (oxygen content 50 ppm) was introduced at a partial pressure of chlorine of 0.04 MPa. After three hours, heating was started, and irradiation of ultraviolet light having a wavelength of 365 nm was performed at an irradiation intensity of 350 K with a high-pressure mercury lamp, thereby starting chlorination reaction.

[0153] Then, the chlorination temperature was kept at 70° C. and the partial pressure of chlorine was kept at 0.04 MPa. The average chlorine consumption rate was adjusted to 0.02 kg/PVC-kg.Math.5 min. When. the amount of added chlorine reached 5.3% by mass, the irradiation of ultraviolet light with the high-pressure mercury lamp and the supply of chlorine gas were terminated, whereby chlorination was terminated.

[0154] Next, unreacted chlorine was removed by nitrogen gas aeration, followed by washing with water, dehydration, and drying. Accordingly, a powdery chlorinated polyvinyl chloride resin (amount of added chlorine: 5.3% by mass) was obtained.

(Evaluation of Chlorinated Polyvinyl Chloride Resin)

(1) Measurement of Amount of Added Chlorine

[0155] The amount of added chlorine in the obtained chlorinated polyvinyl chloride resin was measured in conformity with JIS K 7229.

(2) Molecular Structure Analysis

[0156] The molecular structure of the obtained chlorinated polyvinyl chloride resin 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).

[0157] The NMR measurement conditions were as follows.

Apparatus: ET-NMRJEOLJNM-AL-300

[0158] Measured nuclei: 13C (proton complete decoupling)
Pulse width: 90°

PD: 2.4 sec

[0159] Solvent: o-dichlorobenzene:deuterated benzene (C5D5)=3:1
Sample concentration: about 20%

Temperature: 110° C.

[0160] Reference material: central signal for benzene set to 128 ppm
Number of scans: 20,000

(3) Weight Average Molecular Weight Measurement

[0161] A sample was dissolved in THF, and filtered through a filter having a pore size of 0.2 μm before the weight average molecular weight was measured using a GPC unit (pump unit: PU-4180, detector unit: RI-4030, column oven: CO-4065) produced by JASCO Corporation and SHODEX columns LF-804 (two columns connected). The measurement was performed by eluting the sample at a measurement flow rate of 0.7 ml/min and an oven temperature of 40° C. and determining the weight average molecular weight using a calibration curve base generated with standard polystyrene equivalent.

(Preparation of Melt Additive X1)

[0162] Raw material polyethylene (5 kg) was fed and melted in a 23-L small polymerizer equipped with a thermometer, a manometer, a stirring device, a gas inlet tube, and a gas exhaust tube. After the internal temperature reached 145° C., the stirring device was set to 250 rotations/min, and air was introduced into the molten product at 1.0 L/min. The raw material polyethylene used was Hi-WAX 800P (produced by Mitsui Chemicals, Inc., molecular weight 8,000, density 970 kg/m.sup.3, crystallinity 84%, melting point 127° C., softening point 140° C.)

[0163] The pressure inside the polymerizer was adjusted to 0.69 MPa via a control valve on the gas exhaust tube side. While air was introduced, the reaction temperature was maintained at 145° C., the stirring speed was maintained at 250 rotations/min, and the pressure was maintained at 0.69 MPa. The reaction was terminated after five hours, whereby a melt additive Xi was obtained. Here, the crystallinity of the polyethylene was measured by X-ray diffractometrv.

(Preparation of Melt Additive Y1)

[0164] A melt additive Y1 was obtained in the same manner as the melt additive X1 except that instead of Hi-WAX 800P, Hi-WAX 720P (produced by Mitsui Chemicals, Inc., molecular weight 7,200, density 920 g/m.sup.3, crystallinity 60%, melting point 113° C., softening point 118° C.) was used as the polyethylene.

(Melt Additive Evaluation)

(1) .SUP.1.H NMR Spectrum

[0165] The obtained melt additive was dissolved in o-dichlorobenzene-d.sub.4 at 130° C. A 400 MHz .sup.1H NMR spectrum was measured by solution NMR using a Bruker spectrometer AV400 model at 130° C. to measure the area ratio of a peak B observed in the range of 0.6 to 1.0 ppm to a peak A observed in the range of 9.5 to 10 ppm.

(2) Melting Point

[0166] The obtained melt additive was subjected to measurement using a differential scanning calorimetry (DSC) device (produced by TA Instruments—Waters LLC, DSC Q20) at a heating rate of 3° C./min in a temperature range of 20° C. to 200° C. in a nitrogen atmosphere.

(3) Molecular Structure Analysis

[0167] An NMR spectrum was used to measure the percentages of the structural units (1) to (3).

[0168] Here, X in the formula (2) was at least one of a hydroxy group, a carboxy group, or an ether group (having an alkyl group bonded thereto).

(4) Weight Average Molecular Weight Measurement

[0169] The weight average molecular weight was measured by a method in conformity with JIS-K-7367-1 (viscosity method).

(Preparation of Melt Additives X2 and X3)

[0170] Melt additives X2 and X3 were obtained by adjusting the molecular structure, the weight average molecular weight (Mw), and the melting point as shown in Table 1. The raw material polyethylenes used were as follows.

[0171] Melt additive X2: polyethylene (molecular weight: 900, density: 950 kg/m.sup.3, crystallinity: 90%, melting point: 116° C., softening point: 121° C.)

[0172] Melt additive X3: polyethylene (molecular weight: 2,000, density: 970 kg/m.sup.3, crystallinity: 87%, melting point: 122° C., softening point: 130° C.)

(Preparation of Melt Additives Y2 and Y3)

[0173] Melt additives Y2 and Y3 were obtained by adjusting the molecular structure, the weight average molecular weight (Mw), the melting point as shown in Table 1. The raw material polyethylenes used were as follows.

[0174] Melt additive Y2: polyethylene (molecular weight: 4,000, density: 930 kg/m.sup.3, crystallinity: 70%, melting point: 113° C., softening point: 118° C.)

[0175] Melt additive Y3: polyethylene (molecular weight: 3,000, density: 930 kg/m.sup.3, crystallinity: 65%, melting point: 109° C., softening point: 114° C.)

EXAMPLE 1

[0176] A resin composition for molding was obtained by uniformly mixing, in a super mixer, 100 parts by mass of the chlorinated polyvinyl chloride resin A with 2.0 parts by mass of an organotin stabilizer (produced by Nitto Kasei Co., Ltd., TVS#1380) as a thermal stabilizer, 4.0 parts by mass of titanium oxide (produced by Venator Materials PLC, R-TC30) as inorganic matter, and 3.0 parts by mass of the melt additive X.

EXAMPLES 2 to 7

[0177] A resin composition for molding was obtained as in Example 1 except that the type of the chlorinated polyvinyl chloride resin. and the type and amount of the melt additive added were changed as shown in Table 1.

Comparative Example 1

[0178] A resin composition for molding was obtained as in Example 1 except that the melt additive Yl was used.

Comparative Examples 2 and 3

[0179] A resin composition for molding was obtained as in Example 1 except that the type and the amount of the melt additive added were changed as shown in Table 1.

[0180] (Evaluation)

[0181] The resin compositions for molding obtained in the examples and the comparative examples were evaluated as follows. Table 1 shows the results.

(Evaluation of resin composition for molding)

(1) Pulse NMR Measurement

[0182] The obtained powdery resin composition for molding 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 100° C. (after holding for 20 minutes) under the conditions below, thereby obtaining a free induction decay curve of .sup.1 H spin-spin relaxation.

<Solid echo method>
Scans: 128 times
Recycle delay: 1 sec
Acquisition scale: 1.0 ms

(Measurement at 100° C.)

[0183] The free induction decay curve up to 0.5 ms obtained at 100° C. was subjected to waveform separation into three curves derived from the A.sub.100 component, the B.sub.100 component, and the C.sub.100 component. The waveform separation was performed by fitting to both a Gaussian model and an exponential model. The percentages of the three components were determined from the curves derived from the components obtained in the measurement.

[0184] Using analysis software “TD-NMRA (Version 4.3, Rev. 0.8)” produced by BRUKER, a Gaussian-model fitting was applied to the A.sub.100 component, and an exponential model fitting was applied to the B.sub.100 component and C100 component in conformity with the product manual.

[0185] The following equation was used in the fitting.

[00001]$\begin{array}{cc}Y=A⨯\exp \left(-\frac{1}{2}⨯{\left(\frac{t}{T_A}\right)}^2\right)+B⨯\exp \left(-\frac{1}{2}⨯{\left(\frac{t}{T_B}\right)}^2\right)+C⨯\exp \left(-\frac{t}{T_C}\right)& \left[\mathrm{Math}.1\right]\end{array}$

[0186] In the formula, A represents the percentage of the A.sub.100 component, B represents the percentage of the B.sub.100 component, C represents the percentage of the C.sub.100 component, T.sub.A represents the relaxation time of the A.sub.100 component, T.sub.B represents the relaxation time of the B100 component, T.sub.C represents the relaxation time of the C100 component, and t represents time.

[0187] The A.sub.100 component, the B.sub.100 component, and the C.sub.100 component are components defined in order of shorter relaxation time in pulse NMR measurement. The value of the relaxation time of each component is not limited.

(2) Surface Smoothness

(Preparation of Extrusion-Molded Article)

[0188] The obtained resin composition for molding was fed to a single screw 65-mm extruder (produced by Ikegai Corporation, “FS-65 mm”) and formed into flat plate-shaped molded articles, each having a thickness of 2 mm and a width of 20 mm, at a resin temperature of 190° C. to 200° C. and an extrusion amount of 20 to 25 kg/hr.

[0189] A surface of a molded article obtained 15 minutes after the start of molding was subjected to measurement of the arithmetic average wavelength (Zλa) using a 3D measurement system (produced by Keyence Corporation, VR-3100).

(3) Presence or Absence Of Deposits During Molding

[0190] In “(2) Surface smoothness”, the presence or absence of deposits on a forming tube five hours after the start of molding was visually determined. “0 (Good)” was given when no deposit was observed, and “x (Poor)” was given when deposits were observed.

[0191] A forming tube is a fixture secured at the end of an extruder and used to adjust the shape of a molded article. When deposits on a molded article surface adhere to a forming tube during extrusion molding, the shape of the molded article cannot be adjusted, causing defective molding.

(4) Continuous Productivity

[0192] Further, a surface of a molded article obtained five hours after the start of molding was similarly subjected to the measurement of the arithmetic average wavelength (Zλa). The continuous productivity was evaluated as “0 (Good)” when the change in the Zλa from after 15 minutes to after 5 hours was within ±110%, and “×(Poor)” when the Zλa changed more than ±10%.

(5) Charpy Impact Value

[0193] An obtained molded article was cut to prepare a specimen (width 10 mm×length 90 mm×thickness 3 mm×notch depth 1 mm) in conformity with JIS K 7111-1:2012. This specimen was subjected to impact value measurement using “U-F IMPACT TESTER SEPT. 1972” produced by Ueshima Seisakusho Co., Ltd. at a temperature of 23° C. The measurement was repeated four times, and each obtained impact value was divided by the thickness of the specimen.

[0194] The average of the quotients was taken as the Charpy impact value of the molded article, and evaluated in accordance with the following criteria.

o (Good): a Charpy impact value of 5 KJ/m.sup.2 or more
x (Poor): a Charpy impact value of less than 5 KJ/m.sup.2

(6) Crack Test

[0195] An obtained molded article was cut to a length of 150 mm to prepare a specimen. This specimen was used to measure crack properties at a temperature of 23° C. using “SHIMADZU AUTOGRAPH AGS”, produced by Shimadzu Corporation. A three-point bend fixture to apply a load to the center of the specimen was used. The loading member was descended by 20 mm at a descent speed of 3 ram/min to apply a load, and the specimen was held for 10 minutes with the load applied thereto. The presence or absence of crack(s) was visually determined, and evaluated in accordance with the following criteria.

[0196] High entanglement in particles of a molded article allows excellent melting and large plastic deformation before breakage, resulting in ductility. Small plastic deformation results in brittleness, causing cracks. The table shows the time until the occurrence of cracking.

o (Good): No crack was observed.
x (Poor): Crack(s) was(were) observed.

TABLE-US-00001 TABLE 1 Example 1 2 3 4 5 6 Resin Chlorinated Amount of added chlorine % 10.6 10.6 10.6 10.6 10.6 5.3 composition polyvinyl by mass for molding chloride Structure Structural unit mol % 25.6 25.6 25.6 25.6 24.2 15.6 resin (b) —CH.sub.2—CCl.sub.2— Weight average — 142000 142000 142000 142000 96600 135000 molecular weight (Mw) Type — A A A A B C Amount parts 100 100.0 100.0 100.0 100.0 100.0 by mass Thermal Organotin thermal stabilizer parts 2.0 2.0 2.0 2.0 2.0 2.0 stabilizer by mass Inorganic Titanium oxide parts 4.0 4.0 4.0 4.0 4.0 4.0 matter by mass Melt Structure Structural unit mol % 95.8 95.8 95.8 87.09 95.8 95.8 additive (1) —CH.sub.2—CH.sub.2— Structural unit mol % 4.1 4.1 4.1 12.10 4.1 4.1 (2) —CH.sub.2—CHX— Structural unit mol % 0.1 0.1 0.1 0.51 0.1 0.1 (3) —CH.sub.2—CHCHO— Before Crystallinity % 84.0 84.0 84.0 90.0 84.0 84.0 modifi- cation After Weight average — 8100 8100 8100 920 8100 8100 modifi- molecular weight (Mw) cation Melting point ° C. 131.8 131.8 131.8 112.4 131.8 131.8 Type — X1 X1 X1 X2 X1 X1 Amount parts 3.0 0.5 7.5 3.0 3.0 3.0 by mass Structural unit (2)/CPVC structural unit (b) — 0.16 0.16 0.16 0.47 0.17 0.26 Molecular weight of melt additive/Molecular — 0.06 0.06 0.06 0.01 0.08 0.06 weight of CPVC Evaluation Melt Solution Area of peak B/Area of peak A 35 35 35 3.5 35 35 additive NMR Resin Pulse 100° Per- A.sub.100 % 71 59 57 79 69 63 composition NMR C. cent- B.sub.100 % 16 13 16 12 19 15 for molding age C.sub.100 % 13 2.6 26.9 9 12.5 22 Molded Surface smoothness (arithmetic μm 140 145 150 170 121 135 article average wavelength Zλa) Deposits (forming side) Rating ∘ ∘ ∘ ∘ ∘ ∘ Continuous productivity Change 5.0 5.5 5.3 7.6 5.8 5.2 (%) Rating ∘ ∘ ∘ ∘ ∘ ∘ Charpy impact value KJ/m.sup.2 7.0 5.7 8.5 6.5 5.2 5.9 Rating ∘ ∘ ∘ ∘ ∘ ∘ Crack test Time 11.2 12.7 10.6 10.8 10.1 10.5 (min) Rating ∘ ∘ ∘ ∘ ∘ ∘ Example Comparative Example 7 1 2 3 Resin Chlorinated Amount of added chlorine % 10.6 10.6 10.6 10.6 composition polyvinyl by mass for molding chloride Structure Structural unit mol % 25.6 25.6 25.6 25.6 resin (b) —CH.sub.2—CCl.sub.2— Weight average — 142000 142000 142000 142000 molecular weight (Mw) Type — A A A A Amount parts 100.0 100.0 100.0 100.0 by mass Thermal Organotin thermal stabilizer parts 2.0 2.0 2.0 2.0 stabilizer by mass Inorganic Titanium oxide parts 4.0 4.0 4.0 4.0 matter by mass Melt Structure Structural unit mol % 93.01 70.30 99.81 75.17 additive (1) —CH.sub.2—CH.sub.2— Structural unit mol % 6.61 29.66 0.01 23.70 (2) —CH.sub.2—CHX— Structural unit mol % 0.01 0.0 0.01 0.82 (3) —CH.sub.2—CHCHO— Before Crystallinity % 87.0 60.0 70.0 65.0 modifi- cation After Weight average — 2200 7410 4050 3100 modifi- molecular weight (Mw) cation Melting point ° C. 118.7 97.4 108.1 96.0 Type — X3 Y1 Y2 Y3 Amount parts 3.0 3.0 3.0 3.0 by mass Structural unit (2)/CPVC structural unit (b) — 0.26 1.16 0.0004 0.93 Molecular weight of melt additive/Molecular — 0.02 0.05 0.03 0.02 weight of CPVC Evaluation Melt Solution Area of peak B/Area of peak A 470 1150 1062 620 additive NMR Resin Pulse 100° Per- A.sub.100 % 61 55 53 55 composition NMR C. cent- B.sub.100 % 10 12 12 13 for molding age C.sub.100 % 29 33 35 32 Molded Surface smoothness (arithmetic μm 144 420 361 398 article average wavelength Zλa) Deposits (forming side) Rating ∘ x x x Continuous productivity Change 5.6 16.7 11.1 14.3 (%) Rating ∘ x x x Charpy impact value KJ/m.sup.2 6.7 4.0 4.5 4.5 Rating ∘ x x x Crack test Time 11.0 9.1 9.9 9.2 (min) Rating ∘ x x x

INDUSTRIAL APPLICABILITY

[0197] The present invention can provide a resin composition for molding that makes it possible to achieve excellent continuous productivity and to produce a molded article having high surface smoothness, capable of reducing defective molding, less likely to crack during use, and also having excellent shock resistance. The present invention can also provide a molded article including the resin composition for molding.