JP4901130B2 - Method for producing chlorinated vinyl chloride resin - Google Patents

Description

The present invention relates to a method for producing a chlorinated vinyl chloride resin.

  Vinyl chloride resin (hereinafter referred to as “PVC”) is used in many fields as a material excellent in mechanical strength, weather resistance, chemical resistance and the like. However, since it is inferior in heat resistance, a chlorinated vinyl chloride resin (hereinafter referred to as “CPVC”) in which heat resistance is improved by chlorinating PVC has been developed.

  Since PVC has a low heat distortion temperature and a usable upper limit temperature is around 60 to 70 ° C., it cannot be used for hot water, whereas CPVC has a heat deformation temperature 20 to 40 ° C. higher than PVC. It can also be used for hot water, and is suitably used for heat-resistant pipes, heat-resistant joints, heat-resistant valves, and the like.

  However, CPVC has a problem that when the chlorine content is 65% by weight or more, there are many unstable structures due to an increase in the ratio of added chlorine atoms, resulting in poor thermal stability. was there.

In order to solve such a problem, various methods for producing CPVC having good thermal stability have been proposed. For example, a method has been proposed in which chlorine having an oxygen concentration of 0.05 to 0.35% by volume is supplied at a specific flow rate and chlorinated at a temperature of 55 to 80 ° C. to obtain CPVC having good thermal stability. However, in this production method, the oxygen concentration is high and the reaction at low temperature is not so excellent in thermal stability, and it is suitable for long-term extrusion molding and injection molding. I couldn't stand it.
Japanese Examined Patent Publication No. 45-30833

Further, as a different production method, a method of chlorinating under ultraviolet irradiation using chlorine having an oxygen concentration of 200 ppm or less has been proposed (see, for example, Patent Document 2). Because of this reaction, CPVC with extremely excellent thermal stability was not obtained.
JP-A-9-328518

The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a method for producing a chlorinated vinyl chloride-based resin having a less unstable structure and excellent thermal stability.

The method for producing a chlorinated vinyl chloride resin according to claim 1, wherein the chlorine content is 65 wt% or more and less than 68 wt%, and —CCl ₂ — contained in the molecular structure is 6.2 mol% or less, A method for producing a chlorinated vinyl chloride resin having —CHCl— of 58.0 mol% or more and —CH ₂ — of 35.8 mol% or less, reaching 5% by weight from the final chlorine content Chlorination after the time when the chlorine consumption rate (chlorine consumption for 5 minutes per 1 kg of raw vinyl chloride resin) is in the range of 0.010 to 0.015 kg / PVC-Kg · 5 min, and 3% by weight Chlorination after the point of reaching the front, chlorine consumption rate (chlorine consumption for 5 minutes per kg of raw vinyl chloride resin) is slower than the chlorine consumption rate and 0.005-0.010 kg / PVC-Kg · 5 min It is carried out at the range And features.

The chlorinated vinyl chloride resin (CPVC) is a resin obtained by chlorinating a vinyl chloride resin (PVC).
The PVC is a vinyl chloride homopolymer, a copolymer of a monomer having an unsaturated bond copolymerizable with a vinyl chloride monomer and a vinyl chloride monomer, or a graft copolymer obtained by graft copolymerizing a vinyl chloride monomer to a polymer. Etc. These polymers may be used independently and 2 or more types may be used together.

  Examples of the monomer having an unsaturated bond copolymerizable with the vinyl chloride monomer include α-olefins such as ethylene, propylene, and butylene; vinyl esters such as vinyl acetate and vinyl propionate; butyl vinyl ether, cetyl vinyl ether, and the like. Vinyl ethers; (meth) acrylic esters such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl acrylate, and phenyl methacrylate; aromatic vinyls such as styrene and α-methylstyrene; vinylidene chloride and vinylidene fluoride And halogenated vinyl vinyls such as N-substituted maleimides such as N-phenylmaleimide and N-cyclohexylmaleimide, and one or more of these are used.

  The polymer for graft copolymerization of vinyl chloride is not particularly limited as long as vinyl chloride is graft-polymerized. For example, ethylene-vinyl acetate copolymer, ethylene-vinyl acetate-carbon monoxide copolymer, Ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate-carbon monoxide copolymer, ethylene-methyl methacrylate copolymer, ethylene-propylene copolymer, acrylonitrile-butadiene copolymer, polyurethane, chlorinated polyethylene, chlorinated Polypropylene etc. are mentioned, These may be used independently and 2 or more types may be used together.

  The average degree of polymerization of the PVC is not particularly limited, and is usually 400 to 3,000, and more preferably 600 to 1,500.

  The polymerization method of the PVC is not particularly limited, and examples thereof include conventionally known water suspension polymerization, bulk polymerization, solution polymerization, and emulsion polymerization.

  When the chlorine content of CPVC is less than 65% by weight, the heat resistance is not sufficiently improved, and when it is 68% by weight or more, the molding processability becomes difficult. It is less than wt%, preferably 66 wt% or more and less than 68 wt%.

The ratio of —CCl ₂ —, —CHCl— and —CH ₂ — contained in the molecular structure of CPVC reflects the site where chlorine is introduced when PVC is chlorinated. Ideally, the PVC before chlorination is in a state in which -CCl ₂ -is 0 mol%, -CHCl- is 50.0 mol%, and -CH ₂ -is 50.0 mol%. With the conversion, -CH _2- decreases and -CHCl- and -CCl _2- increase. At this time, if the steric hindrance and unstable -CCl _2- increases too much, or if the chlorinated portion and the non-chlorinated portion are biased in the same particle of CPVC, the chlorinated state is highly uneven. Thus, the thermal stability is greatly impaired. -CCl ₂ - 6.2 mol% or less, -CHCl- 58.0 mol% or more, and, -CH ₂ - is the out of the range of less than 35.8 mol%, the effect of this inhomogeneous chlorinated Therefore, -CCl _2- contained in the molecular structure of CPVC according to claim 1 is 6.2 mol% or less, and -CHCl- is 58.0 mol%. In addition, —CH ₂ — is 35.8 mol% or less. It is preferable that -CCl ₂ -is 5.9 mol% or less, -CHCl- is 59.5 mol% or more, and -CH ₂ -is 34.6 mol% or less because thermal stability is more excellent.

  The CPVC preferably contains 30.0 mol% or less of vinyl chloride units (hereinafter referred to as “VC units”) having a quadruple or more contained in the molecular structure.

The VC unit is an unchlorinated PVC unit, which is —CH ₂ —CHCl—, and a VC unit of 4 or more means a unit in which 4 or more VC units are continuously bonded. .

  The VC unit present in CPVC serves as a starting point for de-HCl, and if this VC unit is continuous, a continuous de-HCl reaction called a zipper reaction tends to occur. That is, as the amount of VC units of the quadruple or larger is increased, de-HCl is more likely to occur and the thermal stability is lowered. Therefore, when the VC unit of 4 or more is more than 30.0 mol%, de-HCl reaction tends to occur and the thermal stability is greatly impaired, so 30.0 mol% or less is preferable, more preferably 28 0.0 mol% or less.

  The CPVC preferably has a UV absorbance at a wavelength of 216 nm of 0.8 or less.

  The UV absorbance is a UV absorbance at a wavelength of 216 nm, in which UV absorption spectrum is measured and -CH = CH-C (= O)-and -CH = CH-CH = CH-, which are different structures in CPVC, have absorption. It is measured by reading the value of.

  In CPVC, the heterogeneous structure in the molecular chain during the chlorination reaction can be quantified based on the value of UV absorbance, and used as an index of thermal stability. In CPVC, since the chlorine atom attached to the carbon adjacent to the double-bonded carbon is unstable, de-HCl occurs from that point, that is, the larger the UV absorbance value, the easier the de-HCl occurs. The thermal stability will be low. When the value of UV absorbance exceeds 0.8, the influence of heterogeneous structures in the molecular chain increases, and as a result, the thermal stability becomes poor. Therefore, the UV absorbance is preferably 0.8 or less.

  Further, the CPVC preferably has a time required for the amount of deHCl to reach 7000 ppm at 190 ° C. of 50 seconds or longer.

  In CPVC, the time required for the amount of HCl removed at 190 ° C. to reach 7000 ppm can be used as an indicator of thermal stability. CPVC undergoes thermal decomposition when exposed to high temperatures, but HCl gas is generated at that time. In other words, the shorter the time required for the amount of HCl removed at 190 ° C. to reach 7000 ppm, the lower the thermal stability. If it is less than 50 seconds, the thermal stability is greatly impaired. It is preferably at least 2 seconds, more preferably at least 60 seconds, and even more preferably at least 70 seconds.

The method for producing a chlorinated vinyl chloride resin according to claim 6 has a chlorine content of 70% by weight or more and less than 72% by weight, and -CCl _2- contained in the molecular structure is 17.0 mol% or less, A method for producing a chlorinated vinyl chloride resin having —CHCl— of 46.0 mol% or more and —CH ₂ — of 37.0 mol% or less, reaching 5% by weight from the final chlorine content Chlorination after the point of time, chlorine consumption rate (chlorine consumption for 5 minutes per 1 kg of raw material vinyl chloride resin) in the range of 0.015-0.020 kg / PVC-Kg · 5 min, and 3% by weight Chlorination after the point of reaching the front, the chlorine consumption rate (chlorine consumption for 5 minutes per 1 kg of the raw vinyl chloride resin) is slower than the chlorine consumption rate and 0.005-0.015 kg / PVC-Kg · 5 min this carried out at the range The features.

  The chlorinated vinyl chloride resin (CPVC) is the same as CPVC according to claim 1, except that the chlorine content is 70 wt% or more and less than 72 wt%. Since the chlorine content is 70% by weight or more and less than 72% by weight, it is suitable for applications requiring particularly high heat resistance, but if it is less than 70% by weight, the improvement in heat resistance is insufficient. If it is 72% by weight or more, moldability becomes extremely difficult.

In general, as CPVC has a higher degree of chlorination, -CC1 _2- increases and the non-uniformity of the chlorination state tends to increase, so the thermal stability is greatly impaired. CPVC contains —CCl ₂ — in the molecular structure of 17.0 mol% or less, —CHCl— of 46.0 mol% or more, and —CH ₂ — of 37.0 mol% or less, preferably − CCl ₂ − is 16.0 mol% or less, —CHCl— is 53.5 mol% or more, and —CH ₂ — is 30.5 mol% or less.

  In the case of CPVC, if the vinyl chloride unit having a quadruple or more contained in the molecular structure exceeds 18.0 mol%, the HCl removal reaction tends to occur and the thermal stability is greatly impaired. Mole% or less is preferable.

  In general, in order to obtain CPVC having a high degree of chlorination, it is exposed to a catalyst or ultraviolet rays for a long time during chlorination, or placed in a high temperature for a long time. However, if the UV absorbance value exceeds 8.0, the influence of heterogeneous structures in the molecular chain increases and the thermal stability becomes inferior. The UV absorbance of CPVC is preferably 8.0 or less.

  Furthermore, the CPVC preferably has a time required for the amount of deHCl to reach 7000 ppm at 190 ° C. of 100 seconds or longer.

  In general, CPVC tends to decrease the amount of deHCl because VC units which are unchlorinated PVC units decrease as the degree of chlorination increases. However, at the same time, a non-uniform chlorination state and an increase in heterogeneous structures occur, resulting in a decrease in thermal stability. When the time required for the amount of HCl removed at 190 ° C. to reach 7000 ppm is less than 100 seconds, the thermal stability is greatly reduced, so it is preferably 100 seconds or more, more preferably 120 seconds or more, Preferably it is 140 seconds or more.

  The chlorinated vinyl chloride resin (CPVC) is a resin obtained by chlorinating a vinyl chloride resin (PVC), and chlorination may be performed by any conventionally known method. It is preferable that liquid chlorine or gaseous chlorine is introduced into the reactor in a state of being suspended in an aqueous solvent.

  As the material of the reactor used for the chlorination reaction, commonly used materials such as a titanium reactor can be applied in addition to a stainless steel reactor with glass lining.

  The method for adjusting the PVC to a suspended state is not particularly limited, and a cake-like PVC obtained by removing a monomer from the polymerized PVC may be used, or the dried PVC is suspended again in an aqueous medium. Alternatively, a suspension obtained by removing undesired substances for the chlorination reaction from the polymerization system may be used. However, it is preferable to use a cake-like resin obtained by removing the polymerized PVC from the monomer. . The amount of the aqueous medium charged into the reactor is not particularly limited, but is generally preferably 2 to 10 parts by weight with respect to 100 parts by weight of PVC.

  Introducing chlorine is efficient in introducing liquid chlorine in the process. In order to adjust the pressure during the reaction and to supply chlorine as the chlorination reaction proceeds, gaseous chlorine can be appropriately blown in addition to liquid chlorine. Moreover, it is preferable to use chlorine after purging 5 to 10% by weight of cylinder chlorine. Although the gauge pressure in the said reactor is not specifically limited, Since chlorine will osmose | permeate the inside of a PVC particle, so that a chlorine pressure is high, the range of 0.3-2 Mpa is preferable.

  The method of chlorinating PVC in the suspended state is not particularly limited. For example, a method of accelerating chlorination by exciting PVC bonds or chlorine with heat (hereinafter referred to as thermal chlorination), irradiation with light. Then, a method of promoting chlorination photoreactively (hereinafter referred to as photochlorination) and the like. The heating method for chlorination with thermal energy is not particularly limited, and for example, heating by an external jacket system from the reactor wall is effective. In addition, when using light energy such as ultraviolet light, an apparatus capable of light energy irradiation such as ultraviolet irradiation under high temperature and high pressure conditions is required. The chlorination reaction temperature in the case of photochlorination is preferably 40 to 80 ° C.

  Among the chlorination methods, a thermal chlorination method in which ultraviolet irradiation is not performed is preferable, and a method of accelerating the chlorination reaction by exciting bonds of vinyl chloride resin or chlorine with only heat or heat and hydrogen peroxide is preferable.

  In the case of chlorination reaction by ultraviolet irradiation, the amount of light energy required for chlorinating PVC is greatly affected by the distance between the PVC and the light source. Due to the difference in energy magnitude, it becomes more difficult to perform uniform chlorination. On the other hand, the method of exciting and chlorinating PVC bonds and chlorine with only heat or heat and hydrogen peroxide without irradiating with ultraviolet rays enables more uniform chlorination reaction, and improves the thermal stability of CPVC. Is possible.

  In the case of chlorination only by heating, when the temperature is lowered, the chlorination rate is lowered, and when it is too high, a deHCl reaction occurs in parallel with the chlorination reaction, and the obtained CPVC is colored. ° C is preferred, more preferably 100-135 ° C.

  The amount of hydrogen peroxide added is preferably from 5 to 500 ppm per hour with respect to PVC because the effect of improving the rate of chlorination is lost when the amount is reduced and the heat resistance of the obtained CPVC is reduced when the amount is increased. The reaction temperature in the case of adding hydrogen peroxide is preferably 60 to 140 ° C., more preferably 65 to 110 ° C., because the chlorination rate is improved by adding hydrogen peroxide.

In claim 1, when obtaining CPVC having a final chlorine content of 65% by weight or more and less than 68% by weight by chlorination of the PVC, after the point when the final chlorine content reaches 5% by weight or less. Chlorination reached a chlorine consumption rate (chlorine consumption for 5 minutes per 1 kg of raw vinyl chloride resin) in the range of 0.010 to 0.015 kg / PVC-Kg · 5 min, and 3% by weight. Chlorination after the time point: Chlorine consumption rate (chlorine consumption for 5 minutes per 1 kg of raw vinyl chloride resin) is slower than the chlorine consumption rate and in the range of 0.005-0.010 kg / PVC-Kg · 5 min It intends line. By doing so, CPVC with less non-uniformity in the chlorinated state and excellent thermal stability can be obtained.

Further, in claim 6, when obtaining a CPVC having a final chlorine content of 70 wt% or more and less than 72 wt% by chlorination of the PVC, a point after the point when the final chlorine content reaches 5 wt% or less is obtained . Chlorination reached a chlorine consumption rate (5 minutes of chlorine consumption per 1 kg of raw vinyl chloride resin) in the range of 0.015 to 0.020 kg / PVC-Kg · 5 min and 3% by weight. Chlorination after the time point, chlorine consumption rate (chlorine consumption for 5 minutes per 1 kg of vinyl chloride resin) is slower than the chlorine consumption rate and in the range of 0.005 to 0.015 kg / PVC-Kg · 5 min It intends line. By doing so, CPVC with less non-uniformity in the chlorinated state and excellent thermal stability can be obtained.

As a method for producing a molded product by molding the obtained CPVC, any conventionally known production method may be employed, for example, an extrusion molding method, an injection molding method, etc. Since it is the molded object which shape | molded the chlorinated vinyl chloride type resin of any one of Claims 1-12, thermal stability is excellent.

  If necessary, the molded product may contain stabilizers, lubricants, processing aids, impact modifiers, heat improvers, antioxidants, ultraviolet absorbers, light stabilizers, fillers, thermoplastic elastomers, pigments, etc. An additive may be added.

  The stabilizer is not particularly limited, and examples thereof include a heat stabilizer and a heat stabilization aid. The heat stabilizer is not particularly limited. Organotin stabilizers such as dibutyltin laurate and dibutyltin laurate polymer; lead stabilizers such as lead stearate, dibasic lead phosphite and tribasic lead sulfate; calcium-zinc stabilizer; barium Zinc-based stabilizers; barium-cadmium-based stabilizers and the like. These may be used alone or in combination of two or more.

  The stabilization aid is not particularly limited, and examples thereof include epoxidized soybean oil, phosphate ester, polyol, hydrotalcite, and zeolite. These may be used alone or in combination of two or more.

Examples of the lubricant include an internal lubricant and an external lubricant.
The internal lubricant is used for the purpose of lowering the flow viscosity of the molten resin during molding and preventing frictional heat generation. The internal lubricant is not particularly limited, and examples thereof include butyl stearate, lauryl alcohol, stearyl alcohol, epoxy soybean oil, glycerin monostearate, stearic acid, and bisamide. These may be used alone or in combination of two or more.

  The external lubricant is used for the purpose of increasing the sliding effect between the molten resin and the metal surface during molding. The external lubricant is not particularly limited, and examples thereof include paraffin wax, polyolefin wax, ester wax, and montanic acid wax. These may be used alone or in combination of two or more.

    The processing aid is not particularly limited, and examples thereof include acrylic processing aids such as alkyl acrylate-alkyl methacrylate copolymers having a weight average molecular weight of 100,000 to 2,000,000. The acrylic processing aid is not particularly limited, and examples thereof include n-butyl acrylate-methyl methacrylate copolymer and 2-ethylhexyl acrylate-methyl methacrylate-butyl methacrylate copolymer. These may be used alone or in combination of two or more.

The impact modifier is not particularly limited, and examples thereof include methyl methacrylate-butadiene-styrene copolymer (MBS), chlorinated polyethylene, and acrylic rubber.
The heat resistance improver is not particularly limited, and examples thereof include α-methylstyrene-based and N-phenylmaleimide-based resins.

It does not specifically limit as said antioxidant, For example, a phenolic antioxidant etc. are mentioned.
The light stabilizer is not particularly limited, and examples thereof include hindered amine light stabilizers.

The ultraviolet absorber is not particularly limited, and examples thereof include salicylic acid ester-based, benzophenone-based, benzotriazole-based, and cyanoacrylate-based ultraviolet absorbers.
The filler is not particularly limited, and examples thereof include calcium carbonate and talc.

  The pigment is not particularly limited, and examples thereof include organic pigments such as azo, phthalocyanine, selenium, and dye lakes; oxides, molybdenum chromates, sulfides / selenides, ferrocyanides, and the like. Examples include inorganic pigments.

  In addition, a plasticizer may be added to the molded body for the purpose of improving processability at the time of molding. However, since the heat resistance of the molded body may be lowered, it is not preferable to use a large amount. Absent. The plasticizer is not particularly limited, and examples thereof include dibutyl phthalate, di-2-ethylhexyl phthalate, and di-2-ethylhexyl adipate.

  Furthermore, a thermoplastic elastomer may be added to the molded body for the purpose of improving workability. The thermoplastic elastomer is not particularly limited. For example, acrylonitrile-butadiene copolymer (NBR), ethylene-vinyl acetate copolymer (EVA), ethylene-vinyl acetate-carbon monoxide copolymer (EVACO). , Vinyl chloride thermoplastic elastomers such as vinyl chloride-vinyl acetate copolymer and vinyl chloride-vinylidene chloride copolymer, styrene thermoplastic elastomer, olefin thermoplastic elastomer, urethane thermoplastic elastomer, polyester thermoplastic elastomer And polyamide-based thermoplastic elastomers. These thermoplastic elastomers may be used alone or in combination of two or more.

  The method for mixing the additive with CPVC is not particularly limited, and examples thereof include a method using hot blending and a method using cold blending.

The structure of the manufacturing method of the chlorinated vinyl chloride resin of the present invention is as described above, and the obtained chlorinated vinyl chloride resin has few unstable structures and is excellent in thermal stability. Moreover, since the molded body is excellent in thermal stability, it is suitably used in applications such as building members, pipe construction equipment, and housing materials. In particular, it is suitably used for large heat-resistant members that require heat resistance and thermal stability.

  Examples of the present invention will be described below, but the present invention is not limited to the following examples.

Example 1
Preparation of chlorinated vinyl chloride resin 200 parts by weight of ion-exchange water and 50 parts by weight of vinyl chloride resin having an average polymerization degree of 1000 are supplied to a glass-lined reaction vessel having an internal volume of 300 liters, and the vinyl chloride resin is ion-exchanged by stirring. After uniformly dispersing in water, the pressure was reduced to remove oxygen in the reaction vessel, and the temperature was raised to 90 ° C.

Next, chlorine is supplied into the reaction vessel so that the partial pressure of chlorine is 0.4 MPa, and the chlorination reaction is performed while adding 1 part by weight (320 ppm / hour) of 0.2 wt% hydrogen peroxide per hour. The reaction was continued until the chlorine content of the chlorinated vinyl chloride resin was 62 % by weight.

  When the chlorine content of the chlorinated vinyl chloride resin reaches 62% by weight (before 5% by weight), the addition amount of 0.2% by weight hydrogen peroxide is 0.1 parts by weight (200 ppm / hour). ), The average chlorine consumption rate is adjusted to 0.012kg / PVC-kg · 5min, chlorination is advanced, and when it reaches 64% by weight (before 3% by weight), 0.2% by weight The amount of hydrogen peroxide added was reduced to 150 ppm / hour per hour, the chlorination was advanced by adjusting the average chlorine consumption rate to 0.008 kg / PVC-kg · 5 min, and the chlorine content was 66.9. A weight percent chlorinated vinyl chloride resin was obtained.

Production of Chlorinated Vinyl Chloride-Based Resin Molded Body To 100 parts by weight of the obtained chlorinated vinyl chloride resin, 1.5 parts by weight of an organic tin stabilizer (trade name “ONZ-100F” manufactured by Sansha Co., Ltd.), 8 parts by weight of impact modifier (trade name “M511” manufactured by Kaneka Chemical Co., Ltd.), 1 part by weight of lubricant (trade name “Hiwax 2203A” manufactured by Mitsui Chemicals, Inc.) and lubricant (trade name “SL800” manufactured by Riken Vitamin Co., Ltd.) ) 0.5 part by weight was added and mixed by stirring to obtain a chlorinated vinyl chloride resin composition. The obtained chlorinated vinyl chloride resin composition was supplied to an extruder (trade name “SLM-50” manufactured by Nagata Seisakusho Co., Ltd.), and extrusion molding was performed at an extrusion resin temperature of 205 ° C. and a screw rotation speed of 19.5 rpm. A pipe-shaped molded body having an outer diameter of 20 mm and a thickness of 3 mm was produced.

(Example 2)
200 parts by weight of ion-exchanged water and 50 parts by weight of vinyl chloride resin having an average polymerization degree of 1000 were supplied to a glass-lined reaction vessel having an internal volume of 300 liters, and the vinyl chloride resin was uniformly dispersed in the ion-exchanged water by stirring. Thereafter, the pressure was reduced to remove oxygen in the reaction vessel, and the temperature was raised to 100 ° C.

Next, chlorine is supplied into the reaction vessel so that the partial pressure of chlorine is 0.4 MPa, and the chlorination reaction is performed while adding 1 part by weight (320 ppm / hour) of 0.2 wt% hydrogen peroxide per hour. The reaction was continued until the chlorine content of the chlorinated vinyl chloride resin was 62 % by weight.

When the chlorine content of the chlorinated vinyl chloride resin reaches 62% by weight (before 5% by weight), the addition amount of 0.2% by weight hydrogen peroxide is 0.1 parts by weight (200 ppm / hour). ), The average chlorine consumption rate is adjusted to 0.012kg / PVC-kg · 5min, chlorination is advanced, and when it reaches 64% by weight (before 3% by weight), 0.2% by weight The amount of hydrogen peroxide added was reduced to 150 ppm per hour, and the chlorination was advanced by adjusting the chlorine consumption rate to 0.008 kg / PVC-kg · 5 min. The chlorine content was 67.3 wt%. A chlorinated vinyl chloride resin was obtained.
Using the obtained chlorinated vinyl chloride resin, a pipe-like molded body was produced in the same manner as in Example 1.

Example 3
Preparation of chlorinated vinyl chloride resin 200 parts by weight of ion-exchange water and 50 parts by weight of vinyl chloride resin having an average polymerization degree of 1000 are supplied to a glass-lined reaction vessel having an internal volume of 300 liters, and the vinyl chloride resin is ion-exchanged by stirring. After uniformly dispersing in water, the pressure was reduced to remove oxygen in the reaction vessel, and the temperature was raised to 100 ° C.

Next, chlorine is supplied into the reaction vessel so that the partial pressure of chlorine is 0.4 MPa, and the chlorination reaction is performed while adding 1 part by weight (320 ppm / hour) of 0.2 wt% hydrogen peroxide per hour. The reaction was continued until the chlorine content of the chlorinated vinyl chloride resin reached 66 % by weight.

When the chlorine content of the chlorinated vinyl chloride resin reached 66% by weight (5% by weight), the amount of 0.2% by weight hydrogen peroxide was reduced to 200 ppm per hour, and the average chlorine consumption The rate is adjusted to 0.016 kg / PVC-kg · 5 min, chlorination proceeds, and when the amount reaches 68% by weight (before 3% by weight), the addition amount of 0.2% by weight hydrogen peroxide is 1 Reduced to 150 ppm per hour and adjusted the chlorine consumption rate to 0.012 kg / PVC-kg · 5 min to advance chlorination to obtain a chlorinated vinyl chloride resin with a chlorine content of 70.7 wt% It was.

Production of Chlorinated Vinyl Chloride Resin Molded Body To 100 parts by weight of the obtained chlorinated vinyl chloride resin, 2.0 parts by weight of an organic tin stabilizer (trade name “ONZ-100F” manufactured by Sansha Gosei Co., Ltd.) , Impact modifier (trade name “M511” manufactured by Kaneka Chemical Co., Ltd.) 8 parts by weight, lubricant (manufactured by Mitsui Chemicals, trade name “Hiwax 2203A”) 1.5 parts by weight and lubricant (trade name, manufactured by Riken Vitamin Co., Ltd.) "SL800") 1.0 part by weight was added and mixed with stirring to obtain a chlorinated vinyl chloride resin composition. The obtained chlorinated vinyl chloride resin composition was subjected to an extrusion machine (trade name “SLM-50”, manufactured by Nagata Seisakusho Co., Ltd.) and subjected to extrusion molding at an extrusion resin temperature of 205 ° C. and a screw rotation number of 19.5 rpm. A pipe-shaped molded body having a diameter of 20 mm and a thickness of 3 mm was produced.

Example 4
200 parts by weight of ion-exchanged water and 50 parts by weight of vinyl chloride resin having an average polymerization degree of 1000 were supplied to a glass-lined reaction vessel having an internal volume of 300 liters, and the vinyl chloride resin was uniformly dispersed in the ion-exchanged water by stirring. Thereafter, the pressure was reduced to remove oxygen in the reaction vessel, and the temperature was raised to 110 ° C.

Next, chlorine is supplied into the reaction vessel so that the partial pressure of chlorine is 0.4 MPa, and the chlorination reaction is performed while adding 1 part by weight (320 ppm / hour) of 0.2 wt% hydrogen peroxide per hour. The reaction was continued until the chlorine content of the chlorinated vinyl chloride resin reached 66 % by weight.

When the chlorine content of the chlorinated vinyl chloride resin reaches 66% by weight (before 5% by weight), the amount of 0.2% by weight hydrogen peroxide added is 0.1 parts by weight ( 200 ppm / hour). Time), the average chlorine consumption rate is adjusted to 0.016kg / PVC-kg · 5min, chlorination is advanced, and when it reaches 68 wt% (3 wt% before), 0.2 wt% % Hydrogen peroxide was reduced to 150 pm per hour, the chlorine consumption rate was adjusted to 0.010 kg / PVC-kg · 5 min, and chlorination proceeded, resulting in a chlorine content of 70.9 wt. % Chlorinated vinyl chloride resin was obtained.
Using the obtained chlorinated vinyl chloride resin, a pipe-shaped molded body was produced in the same manner as in Example 3.

(Comparative Example 1)
200 parts by weight of ion-exchanged water and 50 parts by weight of a vinyl chloride resin having an average polymerization degree of 1000 are supplied to a glass-lined reaction vessel having an internal volume of 300 liters and stirred to ionize the vinyl chloride resin. After being dispersed in the exchanged water, the pressure was reduced to remove oxygen in the reaction vessel, and the temperature was raised to 60 ° C.

Next, chlorine is supplied into the reaction vessel so that the partial pressure of chlorine is 0.05 MPa, and a chlorination reaction is performed by irradiating a mercury lamp at an intensity of 30 kwh. The chlorine content of the chlorinated vinyl chloride resin The reaction was continued until 67.3 wt%.
Using the obtained chlorinated vinyl chloride resin, a pipe-like molded body was produced in the same manner as in Example 1.

( Comparative Example 2 )
Preparation of chlorinated vinyl chloride resin 200 parts by weight of ion-exchanged water and 50 parts by weight of vinyl chloride resin having an average degree of polymerization of 800 parts are fed into a 300-liter glass-lined reaction vessel having a light irradiation facility inside and stirred. Then, after the vinyl chloride resin was dispersed in ion-exchanged water, the pressure was reduced to remove oxygen in the reaction vessel, and the temperature was raised to 60 ° C.

Next, chlorine is supplied into the reaction vessel so that the partial pressure of chlorine is 0.05 MPa, and a chlorination reaction is performed by irradiating a mercury lamp at an intensity of 30 kwh. The chlorine content of the chlorinated vinyl chloride resin The reaction was continued until 70.0% by weight.
Using the obtained chlorinated vinyl chloride resin, a pipe-shaped molded body was produced in the same manner as in Example 3.

Above Examples 1 to 4 and the chlorine content of the chlorinated vinyl chloride resin obtained in Comparative Examples 1 and 2, by measuring the UV absorbance and de HCl time, -CCl perform molecular structure analysis ₂ -, - CHCl- And the molar ratio of —CH ₂ — and the molar ratio of VC units of four or more ligands were measured, and the results are shown in Table 1. Further, the thermal stability of the obtained pipe-shaped molded body was measured, and the results are shown in Table 1.

The measurement method is as follows.
(1) Measurement of chlorine content The chlorine content was measured according to JIS K 7229.

(2) Molecular structure analysis A. Komoroski, R.A. G. Parker, J .; P. Measurement was performed in accordance with the NMR measurement method described in Shocker, Macromolecules, 1985, 18, 1257-1265.

The NMR measurement conditions are as follows.
Apparatus: FT-NMRJEOLJNM-AL-300
Measurement nucleus: 13C (proton complete decoupling)
Pulse width: 90 °
PD: 2.4 sec
Solvent: o-dichlorobenzene: deuterated benzene (C5D5) = 3: 1
Sample concentration: about 20%
Temperature: 110 ° C
Reference substance: The number of integrations when the central signal of benzene is 128 ppm: 20000 times

(3) Measurement of UV absorbance (216 nm)
The UV absorbance at a wavelength of 216 nm was measured under the following measurement conditions.
Apparatus: Self-recording spectrophotometer Hitachi U-3500
Solvent: THF
Concentration: Sample 20 mg / THF 25 ml... 800 ppm (Examples 1 and 2 and Comparative Example 1)
Sample 10 mg / THF 25 ml ... 800 ppm (Examples 3 to 5)

(4) 1 g of chlorinated vinyl chloride resin obtained in the HCl removal time is placed in a test tube, heated at 190 ° C. using an oil bath, the generated HCl gas is recovered, dissolved in 100 ml of ion-exchanged water, and the pH is measured. did. From the pH value, it was calculated how many g of HCl was generated per 1 million g of the chlorinated vinyl chloride resin, and the time until this value reached 7000 ppm was measured.

(5) Evaluation of thermal stability The obtained pipe-shaped molded body was cut into 2 cm x 3 cm, a predetermined number was put in a gear oven at 200 ° C, taken out every 10 minutes, and the blackening time was measured.

Claims (12)

The chlorine content is 65 wt% or more and less than 68 wt%, -CCl _2- contained in the molecular structure is 6.2 mol% or less, -CHCl- is 58.0 mol% or more, and -CH ₂ -Is a method for producing a chlorinated vinyl chloride resin having 35.8 mol% or less, and the chlorination after the point when the final chlorine content reaches 5% by weight is the chlorine consumption rate (raw material vinyl chloride resin) Chlorination after the point of reaching 3 wt% in the range of 0.010 to 0.015 kg / PVC-Kg · 5 min (chlorine consumption for 5 minutes per kg) Chlorinated vinyl chloride resin characterized in that the chlorine consumption for 5 minutes per kg of vinyl resin) is slower than the chlorine consumption rate and in the range of 0.005 to 0.010 kg / PVC-Kg · 5 min. Manufacturing method. -CCl _2- contained in the molecular structure of the chlorinated vinyl chloride resin is 5.9 mol% or less, -CHCl- is 59.5 mol% or more, and -CH ₂ -is 34.6 mol% or less. The method for producing a chlorinated vinyl chloride resin according to claim 1, wherein:   3. The production of a chlorinated vinyl chloride resin according to claim 1 or 2, wherein the vinyl chloride unit of 4 or more ligands contained in the molecular structure of the chlorinated vinyl chloride resin is 30.0 mol% or less. Method.   The method for producing a chlorinated vinyl chloride resin according to claim 1, 2, or 3, wherein the UV absorbance of the chlorinated vinyl chloride resin at a wavelength of 216 nm is 0.8 or less. The method for producing a chlorinated vinyl chloride resin according to any one of claims 1 to 4, wherein the time required for the amount of HCl removed at 190 ° C of the chlorinated vinyl chloride resin to reach 7000 ppm is 50 seconds or more. . The chlorine content is 70 wt% or more and less than 72 wt%, —CCl ₂ — contained in the molecular structure is 17.0 mol% or less, —CHCl— is 46.0 mol% or more, and —CH ₂ -Is a method for producing a chlorinated vinyl chloride resin having a content of 37.0 mol% or less, wherein the chlorination after the point when the final chlorine content reaches 5% by weight is determined by the chlorine consumption rate (raw material vinyl chloride resin). Chlorination after the point of reaching 5 wt% in the range of 0.015-0.020kg / PVC-Kg · 5min) (chlorine consumption for 5 minutes per kg) Chlorinated vinyl chloride resin characterized in that the chlorine consumption for 5 minutes per kg of vinyl resin) is slower than the chlorine consumption rate and in the range of 0.005 to 0.015 kg / PVC-Kg · 5 min. Manufacturing method. -CCl ₂ contained in the molecular structure of the chlorinated vinyl chloride resin - 16.0 mol% or less, -CHCl- is 53.5 mol% or more, and, -CH ₂ - is at 30.5 mol% The method for producing a chlorinated vinyl chloride resin according to claim 6.   The production of a chlorinated vinyl chloride resin according to claim 6 or 7, wherein a vinyl chloride unit of 4 or more ligands contained in the molecular structure of the chlorinated vinyl chloride resin is 18.0 mol% or less. Method.   9. The method for producing a chlorinated vinyl chloride resin according to claim 6, 7 or 8, wherein the UV absorbance of the chlorinated vinyl chloride resin at a wavelength of 216 nm is 8.0 or less.   The method for producing a chlorinated vinyl chloride resin according to any one of claims 6 to 9, wherein the time required for the amount of HCl removed at 190 ° C of the chlorinated vinyl chloride resin to reach 7000 ppm is 100 seconds or more. .   The chlorination is carried out by introducing liquid chlorine or gaseous chlorine into the reactor while the vinyl chloride resin is suspended in an aqueous solvent. A method for producing a chlorinated vinyl chloride resin. 12. The method for producing a chlorinated vinyl chloride resin according to claim 11, wherein the chlorination is carried out by irradiating the bond of vinyl chloride resin or chlorination with heat and hydrogen peroxide without performing ultraviolet irradiation.