TWI428361B - Production method of vinyl chloride-based resin (2) - Google Patents

Description

Method for producing chlorinated vinyl chloride resin (2) Field of invention

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

Background of the invention

A vinyl chloride resin (hereinafter referred to as "PVC") is a material excellent in mechanical strength, weather resistance, and chemical resistance, and is used in many technical fields. However, chlorinated vinyl chloride resin (hereinafter referred to as "CPVC") which further chlorinates PVC to improve heat resistance has been developed due to poor heat resistance.

CPVC has the characteristics of flame retardancy, weather resistance and chemical resistance, which are advantages of PVC, and improves the mechanical properties at high temperatures, which are known as PVC defects, and is used in various applications for useful resins. on. That is, CPVC retains the excellent flame retardancy, weather resistance and chemical resistance of PVC, and the heat distortion temperature is 20~40 °C higher than that of PVC. Therefore, the upper limit temperature of PVC is about 60~70 °C, and CPVC is 100. It can be used around °C, and is used in heat-resistant tubes, heat-resistant sheets, and heat-resistant industrial boards.

However, CPVC is produced when the chlorine content is above 65% by weight. Many unstable structures due to an increase in the proportion of additional chlorine atoms have a problem of deterioration in thermal stability.

In order to solve such problems, various methods for producing heat-stable CPVC have been proposed.

For example, a method of supplying chlorine having an oxygen concentration of 0.05 to 0.35% by volume at a specific flow rate and chlorinating at a temperature of 55 to 80 ° C to produce a CPVC having good thermal stability has been proposed (refer to Patent Document 1) ). However, in such a production method, since the oxygen concentration is high and the reaction is carried out at a low temperature, the thermal stability is not particularly excellent, and it is not possible to withstand long-term extrusion molding and injection molding.

Further, as a different production method, a method of chlorinating with chlorine having an oxygen concentration of 200 ppm or less and chlorination under ultraviolet irradiation has been proposed (see, for example, Patent Document 2), but such a production method is irradiated with ultraviolet rays. When the reaction is carried out at a low temperature, CPVC which is particularly excellent in thermal stability cannot be obtained.

In addition, a method of using hydrogen peroxide to control the reaction rate has been proposed. For example, a method has been proposed in which a polyvinyl chloride is suspended in an aqueous solvent in a closable container, and after decompressing the inside of the container, chlorine is introduced into the container to be polymerized at a temperature of 90 to 140 ° C. Chlorinated ethylene chloride; and, in the chlorination process, when the chlorine content of the polyvinyl chloride in the reaction is 60% by weight or more, hydrogen peroxide is added to the polyvinyl chloride at a rate of 5 to 50 ppm/hr (refer to For example, Patent Document 3). However, since this method controls the reaction rate at a fixed chlorine content of 60% by weight regardless of the chlorine content of the CPVC to be produced, it is desirable to manufacture a CPVC for higher heat-resistance (for example, a chlorine content of 65 wt%). When CPVC is above %, the more the chlorine content is increased, the reaction The speed is extremely reduced, and the productivity is significantly deteriorated, so that thermal stability and productivity cannot be fully taken into account.

Patent Document 1: Japanese Patent Publication No. 45-30883

Patent Document 2: Japanese Patent Laid-Open No. Hei 9-328518

Patent Document 3: Japanese Patent Laid-Open Publication No. 2001-151815

Summary of invention

The present invention has been made in view of the above-described problems of the prior art, and an object of the invention is to provide a chlorinated vinyl chloride resin having a low stability structure and excellent thermal stability and a molded article thereof.

Further, an object of the present invention is to provide a chlorinated vinyl chloride resin which is excellent in productivity and which has excellent thermal stability by suppressing generation of unstable structure (particularly, a chlorinated vinyl chloride having a chlorine content of 65% by weight or more A method of producing a resin).

The chlorinated vinyl chloride resin (CPVC) of the present invention is characterized in that the chlorine content is 65% by weight or more and less than 69% by weight, the -CCl2- contained in the molecular structure is 6.2 mol% or less, and the -CHCl- is 58.0. More than or equal to mol%, and -CH2- is 35.8 mol% or less.

Moreover, such CPVC is preferably: (1) -CCl2- contained in the molecular structure is 5.9 mol% or less, -CHCl- is 59.5 mol% or more, and -CH2- is 34.6 mol% or less; (2) The vinyl chloride unit of the tetrad or higher contained in the molecular structure is 30.0 mol% or less; (3) the UV absorbance at a wavelength of 216 nm It is 0.8 or less; and/or (4) The time required for the amount of dehydrochlorination at 190 ° C to reach 7000 ppm is 50 seconds or more.

Further, another CPVC of the present invention is characterized in that the chlorine content is 69% by weight or more and less than 72% by weight, the -CCl2- contained in the molecular structure is 17.0 mol% or less, and the -CHCl- is 46.0 mol% or more. And -CH2- is 37.0 mol% or less.

Moreover, such CPVC is preferably: (1) -CCl2- contained in the molecular structure is 16.0 mol% or less, -CHCl- is 53.5 mol% or more, and -CH2- is 30.5 mol% or less; (2) The vinyl chloride unit of the tetrad or higher contained in the molecular structure is 18.0 mol% or less; (3) the UV absorbance at a wavelength of 216 nm is 8.0 or less; and/or (4) at 190 ° C The time required for the amount of dechlorination to reach 7000 ppm is 100 seconds or more.

In addition, in the case of the above-mentioned CPVC, it is more preferable to: obtain the chlorine by introducing liquid chlorine or gaseous chlorine into the reactor for chlorination by suspending the vinyl chloride resin in an aqueous solvent; It is especially preferred that the ultraviolet rays are not irradiated, and only the combination of heat or heat with hydrogen peroxide to carry out the combination of the vinyl chloride resin and the excitation of chlorine is preferred.

Further, the molded article of the present invention is characterized in that it is obtained by molding the above-mentioned CPVC.

Further, in the method for producing CPVC of the present invention, a vinyl chloride resin is dispersed in an aqueous medium in a sealed reaction vessel, and after decompressing the inside of the reaction vessel, chlorine is introduced into the vessel to chlorinate the vinyl chloride resin. The method for manufacturing the CPVC includes the step of controlling the rate of chlorine consumption, that is, at a time point when the chlorinated vinyl chloride resin reaches a final chlorine content of 5% by weight. The chlorine consumption rate (the chlorine consumption per 5 kg of the raw material vinyl chloride resin, the same definition below) is chlorinated in the range of 0.010 to 0.020 kg/PVC-Kg‧5 min; and the final chlorine content is still 3 At the time of weight %, chlorination was carried out at a chlorine consumption rate in the range of 0.005 to 0.015 kg/PVC-Kg‧5 min.

In this method, the chlorine consumption rate should be controlled so that when the final chlorine content (1) is 65% by weight or more and less than 70% by weight, the chlorine consumption rate is 0.010% at the time point when the difference is 5% by weight. Chlorination in the range of 0.015kg/PVC-Kg‧5min, and chlorination at a chlorine consumption rate of 0.005~0.010kg/PVC-Kg‧5min at the time of reaching 3% by weight; or When (2) is 70% by weight, chlorination is carried out at a chlorine consumption rate in the range of 0.015 to 0.020 kg/PVC-Kg‧5 min at a time point of reaching 5% by weight, and 3 weights are reached at the time of arrival. At the time point of %, chlorination was carried out at a chlorine consumption rate in the range of 0.005 to 0.015 kg/PVC-Kg‧5 min.

The invention can produce a CPVC with less stable structure and excellent thermal stability.

In addition, because of its excellent thermal stability, it can be used in construction components, construction piping machinery and residential materials, especially large heat-resistant components that require heat resistance and thermal stability.

Further, CPVC (especially CPVC having a chlorine content of 65% by weight) which is excellent in productivity and which is excellent in thermal stability by suppressing generation of unstable structure can be easily and simply manufactured.

Detailed description of the preferred embodiment Best mode for carrying out the invention

The chlorinated vinyl chloride resin (CPVC) of the present invention is a chlorinated vinyl chloride resin (PVC).

The PVC may, for example, be a vinyl chloride monomer, a monomer having an unsaturated bond copolymerizable with a vinyl chloride monomer, a copolymer of a vinyl chloride monomer (preferably containing 50% by weight), and a polymer and a vinyl chloride. The monomer is a graft copolymer copolymerized by a graft copolymerization or the like. These polymers may be used alone or in combination of two or more.

Examples of the monomer having an unsaturated bond copolymerizable with the above vinyl chloride monomer include α-olefins such as ethylene, propylene, and butylene; vinyl esters such as vinyl acetate and vinyl propionate; and butyl vinyl ester. And vinyl esters such as cetyl vinyl ester; (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl acrylate and phenyl methacrylate; styrene, α- An aromatic vinyl such as methyl styrene; a halogenated ethylene vinyl such as vinylidene chloride or vinylidene fluoride; an N-substituted Malay such as N-phenyl maleimide or N-cyclohexylmaleimide Yttrium imines; (meth)acrylic acid; maleic anhydride; and, acrylonitrile. These may be used singly or in combination of two or more.

The polymer which graft-polymerizes the above-mentioned vinyl chloride is only required to be a graft polymerization of vinyl chloride, and is not particularly limited, and examples thereof include ethylene-vinyl acetate copolymer and ethylene-acetic acid. Vinyl ester-carbon monoxide copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer, ethylene-butyl acrylate-carbon monoxide copolymer, ethylene-methyl methacrylate copolymer, ethylene-propylene copolymer, propylene Nitrile-butadiene copolymer, poly Aurethane, chlorinated polyethylene, chlorinated polypropylene, and the like. These may be used singly or in combination of two or more.

The average degree of polymerization of the aforementioned PVC is not particularly limited, and is preferably from 400 to 3,000, more preferably from 600 to 1,500, which is usually used. Further, the average particle diameter of the PVC is preferably from 100 to 200 μm in consideration of the time required for the operation and the chlorination reaction.

The polymerization method of the above PVC is not particularly limited, and examples thereof include water suspension polymerization, bulk polymerization, solution polymerization, emulsion polymerization, and the like which have hitherto been known. In the polymer, for example, a vinyl chloride monomer, an aqueous solvent, a dispersing agent, and a polymerization initiator are added to the polymerization vessel, and the polymerization is carried out by raising the temperature to a predetermined polymerization temperature to increase the polymerization conversion ratio of the vinyl chloride monomer to 70. After a predetermined ratio of ~90% by weight, the treatment of cooling, venting and demonomerization is carried out to obtain a slurry containing PVC, and the slurry is dehydrated and dried to obtain PVC.

Examples of the dispersing agent include water-soluble celluloses such as methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, and hydroxypropyl methyl cellulose; partially saponified polyvinyl alcohol, oxidized polyethylene, and acrylic polymer. And water-soluble polymers such as gelatin; water-soluble emulsifiers such as sorbitan monolaurate and polyoxyethylene sorbitan monolaurate.

The polymerization initiator may, for example, be peroxydicarbonate such as dioxane; diisopropyl peroxycarbonate, di-2-ethylhexyl peroxycarbonate or diethoxyethyl peroxycarbonate; Peroxyesteric acid α-anisole, peroxynonic acid tert-butyl ester, peroxytriacetic acid tert-butyl ester, peroxy neopentyl tridecyl ester and other peroxy ester compounds; 2, 2-even Azobutyronitrile, 2,2-azobis-2,4-dimethylvaleronitrile, 2,2-azobis(4-methoxy-2,4-dimethylvaleronitrile) Compound.

Further, a polymerization regulator, a chain shifting agent, a pH adjuster, a crosslinking agent, a stabilizer, a filler, an antioxidant, and a scale inhibitor may be added to the polymerization of vinyl chloride.

The chlorine content of the CPVC of the present invention is preferably 65% by weight or more, and if the chlorine content is less than 65% by weight, the heat resistance is likely to be insufficient. Further, when heat resistance is required to be particularly high, it is preferably 69% by weight or more, and the formability is also improved.

In this case, it is preferred that -CCl2- contained in the molecular structure is 17.0 mol% or less, -CHCl- is preferably 46.0 mol% or more, and -CH2- is preferably 37.0 mol% or less.

The ratio of -CCl2-, -CHCl-, and -CH2- contained in the molecular structure reflects the portion into which chlorine is introduced during chlorination of PVC. The PVC before chlorination is desirably approximately -CCl2- of 0 mol%, -CHCl- is 50.0 mol%, and -CH2- is 50.0 mol%.

With chlorination (as the degree of chlorination increases) -CH2- decreases, -CCl2- and -CHCl- increase. At this time, since the three-dimensional structure hinders the large and unstable - excessive increase of CCl2-, if the portion which is chlorinated in the same molecule of CPVC is biased with the portion which is not chlorinated, the unevenness of the chlorinated state increases, and The thermal stability is greatly impaired. Therefore, the components in the molecular structure are preferably within the aforementioned ranges.

In particular, the chlorine content of the CPVC is more preferably (1) 65 wt% or more and less than 69 wt%, or (2) 66 wt% or more and less than 69 wt%, or (3) 69 wt% or more, or (4) 69% by weight or more and less than 72% by weight.

When the chlorine content is (1) or (2), -CCl2- is preferably 6.2 mol% or less. Preferably, -CHCl- is 58.0 mol% or more and -CH2- is preferably 35.8 mol% or less. This is to minimize the effects of uneven chlorination to improve thermal stability. Further, when -CCl2- is 5.9 mol% or less, -CHCl- is 59.5 mol% or more, and -CH2- is 34.6 mol% or less, thermal stability is more preferable, and therefore it is more preferable.

When the chlorine content is (3) or (4), -CCl2- is preferably 17.0 mol% or less in the molecular structure, -CHCl- is preferably 46.0 mol% or more, and -CH2- is preferably 37.0 mol% or less. . Although CPVC has a tendency to increase -CCl2- and increase chlorination unevenness as the degree of chlorination increases, the thermal stability can be further improved by making it into the aforementioned range. Further, it is more preferable that -CCl2- is 16.0 mol% or less, -CHCl- is 53.5 mol% or more, and -CH2- is 30.5 mol% or less.

The CPVC of the present invention has a vinyl chloride unit (hereinafter referred to as "VC unit") having a tetrad or higher in a molecular structure of preferably 30.0 mol% or less, more preferably 28.0 mol% or less.

In particular, when the CPVC chlorine content of the present invention is (3) and (4), the CPVC content of the CPVC or more in the molecular structure is preferably 18.0 mol% or less.

The VC unit present in the CPVC will be the starting point for dehydrochlorination, and if the VC unit is continuous, it will easily cause a continuous dehydrogenation reaction called a chain reaction. That is to say, the larger the amount of VC units above the four-unit group, the more likely the dehydrogenation reaction is caused and the thermal stability is lowered.

In addition, the aforementioned VC unit means an unchlorinated PVC unit, which is -CH2-CHCl-, and a VC unit of four or more units means 4 or more VC units. A unit that is continuously combined.

Further, the UV absorbance of the CPVC of the present invention at a wavelength of 216 nm is preferably 8.0 or less. In particular, when the chlorine content of the CPVC of the present invention is (1) and (2), it is preferably 0.8 or less.

In the case of CPVC, the heterogeneous structure of the molecular chain during the chlorination reaction can be quantified by the UV absorbance value as an indicator of thermal stability. In CPVC, a chlorine atom attached to a carbon atom adjacent to a carbon atom bonded by a double bond is unstable, and dehexamation is started as a starting point. That is, the greater the UV absorbance, the more likely the dehydrogenation occurs and the lower the thermal stability.

In general, in order to obtain CPVC with high chlorination degree, it will be exposed to catalyst or ultraviolet light for a long time during chlorination, or placed in a high temperature for a long time, so that the heterogeneous structure in the CPVC molecular chain increases, resulting in heat. Stability is greatly impaired.

The value of UV absorbance is determined by the method of measuring the ultraviolet absorption spectrum, and then reading the heterogeneous structure in CPVC - CH=CH-C(=O)- and -CH=CH-CH=CH-absorbable UV absorbance at 216 nm.

The time required for the amount of de-HCl of the CPVC to reach 7000 ppm at 190 ° C is preferably 50 seconds or more, more preferably 60 seconds or more, and still more preferably 70 seconds or more.

In particular, when the chlorine content of the CPVC of the present invention is (3) and (4), the time required for the amount of dehydrochlorination at 190 ° C to reach 7000 ppm is preferably 100 seconds or more, more preferably 120 seconds or more, and more preferably. It is more than 140 seconds.

In the case of CPVC, it can be reached by the amount of de-HCl in 190 °C. The time required for 7000 ppm is used as an indicator of thermal stability. If the CPVC is exposed to high temperatures, it will cause thermal decomposition, at which point HCl gas will occur. That is, the shorter the time required for the amount of de-HCl to reach 7000 ppm at 190 ° C, the lower the thermal stability.

As the degree of chlorination of CPVC increases, the VC unit of unchlorinated PVC units will decrease, so the amount of HCl removal tends to decrease. However, at the same time, an uneven chlorination state and an increase in heterogeneous structure are caused, and thermal stability is lowered, so that the amount of de-HCl is required to be suppressed to be small.

The CPVC-based PVC chlorinated resin of the present invention can be chlorinated by any of the known methods. For example, it is preferred to suspend the PVC in an aqueous solvent in a reactor, and then introduce liquid chlorine or gaseous chlorine into the reactor for chlorination.

For example, the reaction vessel is preferably a hermetic pressure-resistant container equipped with a stirring device, a heating device, a cooling device, a pressure reducing device, and an illuminating device. The material of the reaction container can be applied to a material generally used such as stainless steel or titanium which is provided in a glass crucible.

The method of adjusting the PVC to the suspension state is not particularly limited, and a cake-like PVC obtained by subjecting the polymerized PVC to de-monomerization may be used, and the dried PVC may be resuspended in an aqueous solvent. in. Alternatively, a suspension from which the material which is not suitable for chlorination is removed from the polymerization system may also be used. Among them, a block resin obtained by subjecting the polymerized PVC to de-monomerization treatment is preferred. The amount of the aqueous solvent to be charged into the reactor is not particularly limited, and is usually 2 to 10 parts by weight based on 100 parts by weight of the PVC.

Chlorine is not particularly limited and can be in a liquid or gaseous state. In. In the process, the use of liquid chlorine is more efficient, but it is also possible to blow chlorine gas more appropriately for the pressure adjustment in the middle of the reaction or the chlorine supply accompanying the chlorination reaction. It is preferred to use chlorine having a chlorine concentration of 100 ppm or less, more preferably 10 ppm or less.

The atmospheric pressure in the reactor is not particularly limited, but the higher the chlorine pressure, the easier the chlorine permeates into the interior of the PVC particles, preferably in the range of 0.3 to 2 MPa.

Further, it is preferred to depressurize the inside of the reaction vessel and remove oxygen before introducing chlorine. If a large amount of oxygen is present, the control of the chlorination reaction is hindered. Therefore, it is preferred to reduce the amount of oxygen in the reaction vessel to 100 ppm or less. At this time, if the supply of chlorine is decreased, the progress of the chlorination reaction is slow, and if a large amount of unreacted chlorine remains after the completion of the reaction, it is not economical. Therefore, it is preferable to supply the chlorine partial pressure in the reaction vessel to 0.03 to 0.5 MPa.

The method for chlorinating PVC is not particularly limited, and examples thereof include a method of promoting chlorination by combining and exciting chlorine by heat (hereinafter referred to as thermal chlorination), and photoreactively promoting chlorine by irradiating light. The method (hereinafter referred to as photochlorination); and the method of heating and simultaneously irradiating light.

The heating method for chlorination by thermal energy is not particularly limited, and for example, heating by an external kit from the reactor wall is effective. In particular, when chlorination is carried out only by heating, the reaction temperature tends to decrease as the chlorination rate is lowered. If the reaction temperature is too high, the dehydrochlorination reaction occurs in parallel with the chlorination reaction, resulting in a tendency of the obtained CPVC to be colored, so that the reaction temperature is preferably It is 70~140 °C, more preferably 100~135 °C.

Further, when light energy such as ultraviolet light is used, it is necessary to irradiate light energy such as ultraviolet light under high temperature and high pressure conditions. Chlorine reaction The chlorination reaction temperature is 40 to 80 °C.

When chlorinating, hydrogen peroxide may be added without irradiating light. When the amount of hydrogen peroxide added is decreased, the effect of increasing the chlorination rate tends to be reduced, and if the amount of hydrogen peroxide is increased, the heat resistance of the obtained PVC tends to be lowered. Therefore, it is preferable to add PVC to the amount of 5 to 500 ppm per hour. . The chlorination rate can be increased by the addition of hydrogen peroxide, and the reaction temperature when adding hydrogen peroxide is preferably 60 to 140 ° C, more preferably 65 to 110 ° C.

In the above chlorination method, a thermal chlorination method which does not perform ultraviolet ray irradiation is preferred, and a method of promoting the chlorination reaction by combining the vinyl chloride resin with hydrogen peroxide by hydrogen or heat and exciting the chlorine to promote the chlorination reaction is preferred.

When chlorination is carried out by ultraviolet rays, the amount of light energy required for chlorination of PVC is greatly affected by the distance between the PVC and the light source. Therefore, the surface and the inside of the PVC particles differ depending on the difference in the amount of the energy, and it is more difficult to perform uniform chlorination. On the other hand, a method of combining only PVC by heat or heat with hydrogen peroxide and exciting chlorine for chlorination without ultraviolet irradiation can achieve a more uniform chlorination reaction and further improve the thermal stability of CPVC.

When the chlorination rate is slowed down, the productivity tends to decrease. When the chlorination is accelerated, the dehydrochlorination reaction occurs, and the obtained CPVC is colored, and the heat resistance tends to be lowered. Therefore, in the present invention, it is preferred to control the chlorination rate (i.e., the rate of chlorine consumption) in the chlorination of PVC.

The method of controlling the chlorine consumption rate includes, for example, controlling the amount of irradiation of light, the reaction rate, and adding hydrogen peroxide.

The light irradiation loses energy as the irradiation distance is extended, so that it is easy to carry out the reaction only in the vicinity of the light irradiation device, and it is difficult to maintain the reaction uniformity. For grams To take this problem, the mixing efficiency must be greatly improved, and the equipment needs to be modified. Further, in order to increase the light irradiation intensity, it is necessary to enhance the ability of the light irradiation device. This requires a large-scale device or a light-increasing device, so it is difficult to change easily and is not economical.

When the temperature is higher than the initial stage of the reaction (above the glass transition temperature of PVC), the chlorination rate will accelerate, but at the same time, the PVC itself will also undergo the dehydrochlorination reaction, and must be set within a range that does not adversely affect the thermal stability. Therefore, the control range of the reaction temperature is made narrower. What's more, it will not be economical to create many equipment expansions such as preparations for high-temperature resistant reaction vessels and peripheral equipment.

The chlorination rate differs even under the same conditions due to the different conditions of chlorination. This is because, as chlorination proceeds, the portion from which the chlorine is easily added in the PVC structure is preferentially reacted. When the chlorine content is more than a certain level, the energy required to add chlorine to the structure increases, and the unstable chlorine will be removed. In the case of a hydrochloric acid reaction or the like, reactions other than chlorine addition also occur at the same time, which is accompanied by a complicated reaction.

From this, it can be seen that in the initial stage of the chlorination reaction, the chlorination rate is generally maintained at a high level even by light irradiation and heating temperature, but in the middle to late stages of the chlorination reaction, the energy is insufficient. The chlorination rate is extremely reduced. To compensate for this phenomenon, a peroxide such as hydrogen peroxide can be added as a catalyst to increase the reaction rate.

When hydrogen peroxide is used as a catalyst for the chlorination reaction, the reaction rate can be controlled by the concentration of hydrogen peroxide and the rate of addition. In particular, hydrogen peroxide can be rapidly and evenly dispersed in an aqueous medium. Can be easily controlled by pump, etc. Add speed. Therefore, it is very suitable for the control by chlorination.

When hydrogen peroxide is introduced in the initial stage of the chlorination reaction, the reaction rate is naturally accelerated to a relatively high speed, and the chlorination reaction time itself can be shortened. However, if the reaction rate is too fast, it will cause an exothermic reaction, and the dehydrochlorination reaction which usually occurs in the late stage of the chlorination reaction becomes easy to occur from the initial stage, so that CPVC will have more double bonds and branches than usual. The unstable structure, the most important initial coloring property and thermal stability are reduced.

The medium to late chlorination reaction can be controlled so that the reaction rate does not decrease by, for example, adding hydrogen peroxide. When it is not added, the time required to reach the chlorine content of the product is prolonged, and the productivity is greatly deteriorated. Even if the heating temperature is to be maintained while maintaining productivity, the effect is not good, and the heating process in the chlorination reaction time is increased, resulting in a decrease in thermal stability.

From this, it can be seen that the state of chlorination (chlorine content) and the rate of chlorine consumption can be controlled by adding hydrogen peroxide, productivity can be improved, the generation of unstable structures can be suppressed, and the thermal history of the heat can be minimized, thereby producing heat. CPVC with excellent stability.

The CPVC production method (see, for example, Patent Document 1) in the prior art controls the chlorine consumption rate at a time when the chlorine content is 60% by weight, thereby improving productivity and initial coloration. However, when the method is applied to a product having a chlorine content of 65% by weight or more, although it has an effect on performance such as heat stability, the productivity is higher as the chlorine content is higher. This is because even if the chlorine content of the CPVC is changed during the reaction, the reaction rate is not controlled with the mixing.

The invention controls the chlorine elimination step by step with the chlorine content of CPVC The speed is consumed, so that the production stability can be ensured while suppressing the occurrence of unstable structures.

For example, the chlorine consumption rate is in the range of 0.005 to 0.05 kg ‧ PVC-Kg ‧ min, to reach the two stages of the final chlorine content of the CPVC to be manufactured, which is still 5% by weight and 3% by weight The method of control.

The method for producing such a CPVC is particularly suitable for producing CPVC having a chlorine content of 65% by weight or more, but the higher the chlorine content, the lower the productivity. In addition, thermal stability is also reduced due to the generation of many unstable structures. In order to balance productivity and thermal stability, it is necessary to control the chlorination rate more precisely.

Therefore, in the case of chlorination of PVC, and to obtain a CPVC having a final chlorine content of 65% by weight or more and less than 70% by weight, it is preferable to control the time point at which the final chlorine content is still 5% by weight. Chlorination at a chlorine consumption rate (5 minutes of chlorine consumption per 1 kg of raw material vinyl chloride resin) in the range of 0.010 to 0.015 kg/PVC-Kg‧5 min; and, after reaching the final chlorine content, the difference is 3% by weight. At the time point, chlorination was carried out at a chlorine consumption rate in the range of 0.005 to 0.010 kg/PVC-Kg‧5 min.

Further, in order to obtain a CPVC having a final chlorine content of 70% by weight or more, and preferably less than 72% by weight, it is preferred to control the chlorine consumption rate at a time point when the final chlorine content is further reduced by 5% by weight. Chlorination in the range of 0.015~0.020kg/PVC-Kg‧5min; and, at the time when the final chlorine content is still 3% by weight, the chlorine consumption rate is 0.005~0.015kg/PVC-Kg‧5min Chlorination is carried out within the range.

Thereby, CPVC having less chlorination unevenness and excellent thermal stability can be obtained.

Further, the control of the chlorine consumption rate may be carried out stepwise or extremely rapidly, but it is preferably carried out slowly.

The molding system of the present invention is obtained by molding the above-mentioned CPVC.

The manufacturing method of the molded body can be any conventionally known manufacturing method, such as an extrusion molding method and an injection molding method. The obtained molded body is excellent in thermal stability.

Additives such as stabilizers, lubricants, processing aids, impact modifiers, heat-resistant improvers, antioxidants, ultraviolet absorbers, light stabilizers, fillers, and pigments may be added to the molded body as needed.

The stabilizer is not particularly limited, and examples thereof include a thermal stabilizer and a thermal stabilizer. The thermal stabilizer is not particularly limited, and examples thereof include decyl dibutyltin, decyldioctyltin, decyldimethyltin, decylbutyltin, dibutyltin maleate, dibutyltin maleate polymer, and dioctyl Organotin stabilizers such as base tin maleate, dioctyltin maleate polymer, dibutyltin laurate, dibutyltin laurate polymer; lead stearate, lead bisphosphite, ternary Lead-based stabilizers such as lead sulfate; calcium-zinc stabilizers; barium-zinc stabilizers; and barium-cadmium stabilizers. These may be used alone or in combination of two or more.

The stabilizer is not particularly limited, and examples thereof include epoxidized soybean oil, phosphate ester, polyhydric alcohol, magnesite, and zeolite. These may be used alone or in combination of two or more.

Examples of the slip agent include internal slip agents and external slip agents.

The internal lubricant is used for the purpose of reducing the dynamic viscosity of the molten resin during the forming process and preventing frictional heat generation. Internal lubricant is not particularly limited, For example, butyl stearate, lauryl alcohol, stearyl alcohol, epoxidized soybean oil, glyceryl monostearate, stearic acid, and biguanide are listed. These may be used alone or in combination of two or more.

The external lubricant is intended to improve the lubricating effect between the molten resin and the metal surface during the forming process. The external lubricant is not particularly limited, and examples thereof include paraffin wax, polyolefin wax, ester wax, and montan wax. These may be used alone or in combination of two or more.

The processing aid is not particularly limited, and examples thereof include an acrylic processing aid such as an alkyl acrylate-alkyl methacrylate copolymer 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 methacrylate-methyl methacrylate copolymer, 2-ethylhexyl acrylate-methyl methacrylate-butyl methacrylate copolymerization. Things and so on. 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-ethylene copolymer (MBS), chlorinated polyethylene, and acrylic rubber.

The heat-resistant improver is not particularly limited, and examples thereof include α-methylstyrene-based and N-phenylmaleamide-based resins.

The antioxidant is not particularly limited, and examples thereof include phenolic antioxidants.

The ultraviolet absorber is not particularly limited, and examples thereof include ultraviolet absorbers such as a salicylate type, a benzophenone type, a benzotriazole type, and a cyanoacrylate type.

The photostabilizer is not particularly limited, and examples thereof include a light stabilizer such as a hindered amine system.

The filler is not particularly limited, and examples thereof include calcium carbonate and talc. The pigment is not particularly limited, and examples thereof include a base pigment such as an azo system, a phthalocyanine system, a threne system, and a lake dye; an oxide system, a molybdenum chromate system, and a sulfide. Inorganic pigments such as ‧ selenide and ferrocyanine.

In order to improve the workability at the time of molding, a plasticizer may be added to the molded body, but the heat resistance of the molded body may be lowered, and it is not preferable to use it in a large amount. The plasticizer is not particularly limited, and examples thereof include dibutyl phthalate, di-2-ethylhexyl phthalate, di-2-ethylhexyl adipate, and the like.

Further, for the purpose of improving workability, a thermoplastic elastomer may be added to the molded body. The thermoplastic elastomer is not particularly limited, and examples thereof include acrylonitrile, butadiene copolymer (NBR), ethylene-vinyl acetate copolymer (EVA), and ethylene-vinyl acetate-carbon monoxide copolymer (EVACO). , vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride thermoplastic elastomer, styrene thermoplastic elastomer, olefin thermoplastic elastomer, polyurethane thermoplastic elastomer, poly An ester-based thermoplastic elastomer, a polyamide-based thermoplastic elastomer, or the like. These thermoplastic elastomers may be used singly or in combination of two or more.

The method of mixing the additive in the CPVC is not particularly limited, and examples thereof include thermal blending and cold blending.

The examples of the method for producing CPVC, the molded article and the CPVC of the present invention are described below, but the present invention is not limited to the following examples.

(Example 1) Modulation of chlorinated vinyl chloride resin

200 parts by weight of ion-exchanged water and 50 parts by weight of PVC having an average degree of polymerization of 1000 were supplied to a glass lining reaction vessel having an internal volume of 300 liters, stirred to uniformly disperse PVC into ion-exchanged water, and oxygen in the reaction vessel was removed under reduced pressure while heating up. To 90 ° C.

No ultraviolet rays were irradiated in this chlorination step.

Next, chlorine is supplied to the reaction vessel to have a chlorine partial pressure of 0.4 MPa, and a chlorination reaction is carried out while adding 0.2% by weight of hydrogen peroxide per 1 hour by weight (320 ppm/hour), and the reaction proceeds to chlorination. The chlorine content of the vinyl chloride resin was as high as 62% by weight.

Next, when the chlorine content of the chlorinated vinyl chloride resin reached 62% by weight (about 5% by weight difference), the addition amount of 0.2% by weight of hydrogen peroxide was reduced to 0.1 part by weight (200 ppm/hour) per hour. , the average chlorine consumption rate is adjusted to 0.012 kg / PVC-Kg ‧ 5 min and then chlorination, and when it reaches 64% by weight (by 3% by weight difference), the amount of 0.2% by weight of hydrogen peroxide is reduced to each After 1 hour of 150 ppm/hour, the average chlorine consumption rate was adjusted to 0.008 kg/PVC-Kg‧5 min, followed by chlorination to obtain a chlorinated vinyl chloride resin having a chlorine content of 66.9 wt%.

Production of CPVC 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 Sankyo Organic Co., Ltd.) and an impact modifier (manufactured by Kaneka Chemical Co., Ltd., trade name) were added. "M511") 1 part by weight of a slip agent (manufactured by Mitsui Chemicals, Inc., trade name "Hiwax 2203A") and 0.5 part by weight of a lubricant (manufactured by Riken Vitamin Co., Ltd., trade name "SL800"), and stirred to obtain CPVC. Composition. The obtained CPVC composition is supplied to an extruder (Changtian The product name "SLM-50" manufactured by Seisakusho Co., Ltd. was extruded at a temperature of 205 ° C and a number of revolutions of 19.5 rpm to prepare a tubular molded body having an outer diameter of 20 mm and a thickness of 3 mm.

(Example 2)

200 parts by weight of ion-exchanged water and 50 parts by weight of PVC having an average degree of polymerization of 1000 were supplied to a glass lining reaction vessel having an internal volume of 300 liters, stirred to uniformly disperse PVC into ion-exchanged water, and oxygen in the reaction vessel was removed under reduced pressure while heating up. To 100 ° C. No ultraviolet rays were irradiated in this chlorination step.

Next, chlorine is supplied to the reaction vessel to have a chlorine partial pressure of 0.4 MPa, and a chlorination reaction is carried out while adding 0.2% by weight of hydrogen peroxide per 1 hour by weight (320 ppm/hour), and the reaction proceeds to chlorination. The chlorine content of the vinyl chloride resin was as high as 62% by weight.

Next, when the chlorine content of the chlorinated vinyl chloride resin reached 62% by weight (about 5% by weight difference), the addition amount of 0.2% by weight of hydrogen peroxide was reduced to 0.1 part by weight (200 ppm/hour) per hour. , the average chlorine consumption rate is adjusted to 0.012 kg / PVC-Kg ‧ 5 min and then chlorination, and when it reaches 64% by weight (by 3% by weight difference), the amount of 0.2% by weight of hydrogen peroxide is reduced to each After 1 hour of 150 ppm/hour, the average chlorine consumption rate was adjusted to 0.008 kg/PVC-Kg‧5 min, followed by chlorination to obtain a chlorinated vinyl chloride resin having a chlorine content of 67.3 wt%.

A tubular molded body was obtained in the same manner as in Example 1 using the obtained chlorinated vinyl chloride resin.

(Example 3) Modulation of chlorinated vinyl chloride resin

200 parts by weight of ion-exchanged water and 50 parts by weight of PVC having an average degree of polymerization of 1000 were supplied to a glass lining reaction vessel having an internal volume of 300 liters, stirred to uniformly disperse PVC into ion-exchanged water, and oxygen in the reaction vessel was removed under reduced pressure while heating up. To 100 ° C. No ultraviolet rays were irradiated in this chlorination step.

Next, chlorine is supplied to the reaction vessel to have a chlorine partial pressure of 0.4 MPa, and a chlorination reaction is carried out while adding 0.2% by weight of hydrogen peroxide per 1 hour by weight (320 ppm/hour), and the reaction proceeds to chlorination. The chlorine content of the vinyl chloride resin was as high as 66% by weight.

Next, when the chlorine content of the chlorinated vinyl chloride resin reaches 66% by weight (about 5% by weight difference), the addition amount of 0.2% by weight of hydrogen peroxide is reduced to 200 ppm/hour per hour to make the average chlorine consumption. The speed was adjusted to 0.016 kg/PVC-Kg‧5 min and chlorination was carried out, and when it reached 68% by weight (from 3% by weight difference), the addition amount of 0.2% by weight of hydrogen peroxide was reduced to 150 ppm/hour per hour. After the average chlorine consumption rate was adjusted to 0.012 kg/PVC-Kg·5 min, chlorination was carried out to obtain a chlorinated vinyl chloride resin having a chlorine content of 70.7 wt%.

Production of CPVC molded body

To 100 parts by weight of the obtained CPVC, 2.0 parts by weight of an organic tin stabilizer (trade name "ONZ-100F", manufactured by Sankyo Organic Co., Ltd.) and an impact modifier (manufactured by Kaneka Chemical Co., Ltd., trade name "M511") were added. In an amount of 1.5 parts by weight, a lubricant (manufactured by Mitsui Chemicals, Inc., trade name "Hiwax 2203A"), 1.5 parts by weight, and a slip agent (manufactured by Riken Chemical Co., Ltd., trade name "SL800"), 1.0 part by weight, were stirred and mixed to obtain a CPVC composition. The obtained CPVC composition was supplied to an extruder (manufactured by Nagata Seisakusho Co., Ltd., trade name "SLM-50"), and the temperature of the extruded resin was 205 ° C. The number of revolutions of the propeller was 19.5 rpm, and extrusion molding was carried out to prepare a tubular molded body having an outer diameter of 20 mm and a thickness of 3 mm.

(Example 4)

200 parts by weight of ion-exchanged water and 50 parts by weight of PVC having an average degree of polymerization of 1000 were supplied to a glass lining reaction vessel having an internal volume of 300 liters, stirred to uniformly disperse PVC into ion-exchanged water, and oxygen in the reaction vessel was removed under reduced pressure while heating up. To 110 ° C. No ultraviolet rays were irradiated in this chlorination step.

Next, chlorine is supplied to the reaction vessel to have a chlorine partial pressure of 0.4 MPa, and a chlorination reaction is carried out while adding 0.2% by weight of hydrogen peroxide per 1 hour by weight (320 ppm/hour), and the reaction proceeds to chlorination. The chlorine content of the vinyl chloride resin was as high as 66% by weight.

Next, when the chlorine content of the chlorinated vinyl chloride resin reached 66% by weight (about 5% by weight difference), the amount of addition of 0.2% by weight of hydrogen peroxide was reduced to 0.1 part by weight (200 ppm/hour) per hour. , the average chlorine consumption rate is adjusted to 0.016 kg / PVC-Kg ‧ 5 min and then chlorination, and when it reaches 68 wt% (from 3% by weight difference), the amount of 0.2% by weight of hydrogen peroxide is reduced to each After 1 hour of 150 ppm/hour, the average chlorine consumption rate was adjusted to 0.010 kg/PVC-Kg·5 min, and chlorination was carried out to obtain a chlorinated vinyl chloride resin having a chlorine content of 70.9 wt%.

A tubular molded body was obtained in the same manner as in Example 3 using the obtained chlorinated vinyl chloride resin.

(Comparative Example 1)

200 parts by weight and average polymerization degree of ion-exchanged water supplied to a glass lining reaction vessel having a light irradiation device inside and having an internal volume of 300 liters 50 parts by weight of a vinyl chloride resin of 1,000 was stirred to uniformly disperse the vinyl chloride resin in ion-exchanged water, and the oxygen in the reaction vessel was removed under reduced pressure while raising the temperature to 60 °C.

Next, chlorine was supplied to the reaction vessel to have a chlorine partial pressure of 0.05 MPa, and the mercury lamp was irradiated with an intensity of 30 kwh to carry out a chlorination reaction until the chlorine content of the chlorinated vinyl chloride resin reached 67.3% by weight.

A tubular molded body was obtained in the same manner as in Example 1 using the obtained chlorinated vinyl chloride resin.

(Example 5) Modulation of chlorinated vinyl chloride resin

200 parts by weight of ion-exchanged water and 50 parts by weight of PVC having an average polymerization degree of 800 were supplied to a glass lining reaction vessel having a light irradiation apparatus and an internal volume of 300 liters, and the mixture was uniformly dispersed in ion-exchanged water by stirring, and the reaction was removed under reduced pressure. The oxygen in the vessel was simultaneously raised to 60 °C.

Next, chlorine was supplied to the reaction vessel to have a chlorine partial pressure of 0.05 MPa, and the mercury lamp was irradiated with an intensity of 30 kwh to carry out a chlorination reaction until the chlorine content of the chlorinated vinyl chloride resin reached 70.0% by weight.

A tubular molded body was obtained in the same manner as in Example 3 using the obtained chlorinated vinyl chloride resin.

The chlorine content, UV absorbance and dehydrochlorination time of the chlorinated vinyl chloride resin obtained in the above Examples 1 to 5 and Comparative Example 1 were measured, and molecular structure analysis was carried out to determine -CCl2-, -CHCl-, and -CH2- Ear ratio and four units The molar ratio of the VC units above the group is shown in Table 1.

The above measurement method is as follows.

(1) Determination of chlorine content

The measurement was carried out in accordance with JIS K 7229.

(2) Analysis of molecular structure

The measurement was carried out in accordance with the NMR measurement method described in R.A. Komorowski, R.G. Parker, J.P. Shocker, Macromolecules, 1985, 18, 1257-1265.

The NMR measurement conditions are as follows.

Device: FT-NMRJEOLJNM-AL-300

Determination of the core: 13C (proton completely decoupled)

Pulse amplitude: 90°

PD: 2.4sec

Solvent: o-dichlorobenzene: heavy hydrogenated benzene (C5D5) = 3:1

Reagent concentration: about 20%

Temperature: 110 ° C

Reference material: The central signal of benzene is 128 ppm.

Cumulative number: 20,000 times

(3) Determination of UV absorbance (216 nm)

The UV absorbance in the wavelength of 216 nm was measured under the following conditions.

Device: Self-recording spectrophotometer Hitachi Ltd. U-3500

Solvent: THF

Concentration: reagent 20 mg / THF 25 ml ... 800 ppm (Examples 1, 2 and Comparative Example 1)

Reagent 10 mg / THF 25 ml ... 400 ppm (Examples 3 to 5)

(4) Dehexamation time

1 g of the obtained chlorinated vinyl chloride resin was placed in a test tube, and heated at 190 ° C using an oil bath, and the produced HCl gas was recovered and dissolved in 100 ml of ion-exchanged water, and the pH was measured. A few g of HCl was produced per 10,000 g of chlorinated vinyl chloride resin from the pH value, and the time to reach 7000 ppm was calculated from this value.

(5) Thermal stability assessment

The obtained tubular molded body was cut into 2 cm × 3 cm, and placed in a gear-oven at 200 ° C in a predetermined number of sheets, taken out every 10 minutes, and the blackening time was measured.

(Example 6)

200 parts by weight of ion-exchanged water and 50 parts by weight of PVC having an average degree of polymerization of 1000 were supplied to a glass lining reaction vessel having an internal volume of 300 liters, stirred to uniformly disperse PVC into ion-exchanged water, and oxygen in the reaction vessel was removed under reduced pressure while heating up. To 100 ° C. No ultraviolet rays were irradiated in this chlorination step.

Next, chlorine is supplied to the reaction vessel to make the partial pressure of chlorine 0.4 MPa, and 0.2% by weight of hydrogen peroxide is added at 320 ppm/hour to cause chlorination. Initially, the reaction was carried out until the chlorine content of the chlorinated PVC reached 62% by weight.

Then, when the chlorine content of the chlorinated PVC reaches 62% by weight (about 5% by weight difference), the addition amount of 0.2% by weight of hydrogen peroxide is reduced to 200 ppm/hour, and the chlorine consumption rate is adjusted to 0.012 kg/PVC. -Kg‧5min is further chlorinated, and when the chlorine content reaches 64% by weight (by 3% by weight difference), the addition amount of 0.2% by weight of hydrogen peroxide is reduced to 150 ppm (/hour) per hour to make chlorine After the consumption rate was adjusted to 0.008 kg/PVC-Kg·5 min, chlorination was carried out, and after 6.0 hours of chlorination, CPVC having a chlorine content of 67% by weight was obtained.

(Example 7)

200 parts by weight of ion-exchanged water and 50 parts by weight of PVC having an average degree of polymerization of 1000 were supplied to a glass lining reaction vessel having an internal volume of 300 liters, stirred to uniformly disperse PVC into ion-exchanged water, and oxygen in the reaction vessel was removed under reduced pressure while heating up. To 100 ° C. Further, no ultraviolet rays are irradiated in the chlorination step.

Next, chlorine is supplied to the reaction vessel to make the partial pressure of chlorine 0.4 MPa, 0.2% by weight of hydrogen peroxide is added at 320 ppm/hour to start the chlorination reaction, and the reaction proceeds until the chlorine content of the chlorinated PVC reaches 66% by weight. .

Next, when the chlorine content of the chlorinated PVC reached 66% by weight (about 5% by weight difference), the addition amount of 0.2% by weight of hydrogen peroxide was reduced to 300 ppm/hour, and the chlorine consumption rate was adjusted to 0.016 kg/ PVC-Kg‧5min was further chlorinated, and when the chlorine content reached 68% by weight (about 3% by weight difference), the addition amount of 0.2% by weight of hydrogen peroxide was reduced to 200 ppm/hour, and the chlorine consumption rate was adjusted to After chlorination at 0.012 kg/PVC-Kg‧5 min, after 9.0 hours of chlorination, a CPVC having a chlorine content of 71% by weight was obtained.

(Comparative Example 2)

200 parts by weight of ion-exchanged water and 50 parts by weight of PVC having an average degree of polymerization of 1000 were supplied to a glass lining reaction vessel having an internal volume of 300 liters, stirred to uniformly disperse PVC into ion-exchanged water, and oxygen in the reaction vessel was removed under reduced pressure while heating up. To 100 ° C. Further, no ultraviolet rays are irradiated in the chlorination step.

Next, chlorine is supplied to the reaction vessel to make the partial pressure of chlorine 0.4 MPa, 0.2% by weight of hydrogen peroxide is added at 320 ppm/hour to start the chlorination reaction, and the reaction proceeds until the chlorine content of the chlorinated PVC reaches 60% by weight. .

When the chlorine content of the chlorinated vinyl chloride resin reaches 60% by weight (by 7% by weight difference), the addition amount of 0.2% by weight of hydrogen peroxide is reduced to 150 ppm/hour, and the chlorine consumption rate is adjusted to 0.005 kg/ PVC-Kg ‧ 5 min was further chlorinated and chlorinated for 8.0 hours to obtain CPVC having a chlorine content of 67% by weight.

(Comparative Example 3)

200 parts by weight of ion-exchanged water and 50 parts by weight of PVC having an average degree of polymerization of 1000 were supplied to a glass lining reaction vessel having an internal volume of 300 liters, stirred to uniformly disperse PVC into ion-exchanged water, and oxygen in the reaction vessel was removed under reduced pressure while heating up. To 100 ° C. Further, no ultraviolet rays are irradiated in the chlorination step.

Next, chlorine is supplied to the reaction vessel to make the partial pressure of chlorine 0.4 MPa, 0.2% by weight of hydrogen peroxide is added at 320 ppm/hour to start the chlorination reaction, and the reaction proceeds until the chlorine content of the chlorinated vinyl chloride resin reaches 60 weight. %until.

Then, when the chlorine content of the chlorinated PVC reaches 60% by weight (by 11% by weight difference), the addition amount of 0.2% by weight of hydrogen peroxide is adjusted so that the chlorine consumption rate is 0.012 kg/PVC-Kg. Chlorination, chlorination, 5 min CPVC having a chlorine content of 67% by weight was obtained in 5.8 hours.

(Comparative Example 4)

200 parts by weight of ion-exchanged water and 50 parts by weight of PVC having an average degree of polymerization of 1000 were supplied to a glass lining reaction vessel having an internal volume of 300 liters, stirred to uniformly disperse PVC into ion-exchanged water, and oxygen in the reaction vessel was removed under reduced pressure while heating up. To 100 ° C. Further, no ultraviolet rays are irradiated in the chlorination step.

Next, chlorine is supplied to the reaction vessel to make the partial pressure of chlorine 0.4 MPa, 0.2% by weight of hydrogen peroxide is added at 320 ppm/hour to start the chlorination reaction, and the reaction proceeds until the chlorine content of the chlorinated vinyl chloride resin reaches 60 weight. %until.

Next, when the chlorine content of the chlorinated PVC reaches 60% by weight (by 11% by weight difference), the addition amount of 0.2% by weight of hydrogen peroxide is reduced to 150 ppm/hour, and the chlorine consumption rate is adjusted to 0.005 kg. /PVC-Kg‧5min was further chlorinated and chlorinated for 18 hours to obtain a CPVC having a chlorine content of 71% by weight.

1.5 parts by weight of an organic tin-based stabilizer (manufactured by Sankyo Organic Synthetic Co., Ltd., trade name "ONZ-100F"), and an MBS-based impact modifier (manufactured by Kaneka Chemical Co., Ltd., trade name "M511"). 8 parts by weight, an acrylic processing aid (manufactured by Mitsubishi Rayon Co., Ltd., trade name "Mitamoto P-550"), 1 part by weight, and a stearic acid-based lubricant (manufactured by Riken Vitamin Co., Ltd., trade name "SL800") 0.5 part by weight of the resin composition was wound up on a roll by a roll of 195 ° C, and the mixture was stirred by a roll for 3 minutes. Further, a heat aging test (200 ° C, every 10 × 140 minutes) for a static thermal stability test was carried out using the obtained roll, and the time (minutes) until blackening was measured.

1 g of the obtained CPVC was placed in a 10 ml glass test tube, heated in an oil bath at 190 ° C under a nitrogen stream, and the hydrochloric acid produced by CPVC was captured in water, and the pH of the water was measured to thereby determine the amount of hydrochloric acid generated. The time to reach 5000ppm.

The chlorination conditions, blackening time, and dehydrochlorination time of each of the examples and comparative examples are shown in Table 2.

Claims (13)

A method for producing a chlorinated vinyl chloride resin, wherein the chlorinated vinyl chloride resin has a chlorine content of 65% by weight or more and less than 68% by weight, and -CCl ₂ - contained in the molecular structure is 6.2 mol% or less, -CHCl - 58.0 mol% or more, and -CH ₂ - is 35.8 mol% or less, and the production method is characterized in that after the chlorinated vinyl chloride resin reaches a final chlorine content of 5% by weight, The chlorine consumption rate (the chlorine consumption per 5 kg of the raw material vinyl chloride resin) is chlorinated in the range of 0.010 to 0.015 kg/PVC-Kg‧5 min, and the time to reach the final chlorine content is also 3 wt%. After that, the chlorination was carried out in a range of 0.005 to 0.010 kg/PVC-Kg‧5 min, which was slower than the chlorine consumption rate and the chlorine consumption rate (the chlorine consumption per 5 kg of the raw material vinyl chloride resin). The method for producing a chlorinated vinyl chloride resin according to the first aspect of the invention, wherein the chlorinated vinyl chloride resin has a molecular structure of -CCl ₂ - of 5.9 mol% or less, and -CHCl- of 59.5 mol. % or more, and -CH ₂ - is 34.6 mol % or less. In the method for producing a chlorinated vinyl chloride resin according to the first or second aspect of the invention, the vinyl chloride unit of the tetrad or higher contained in the molecular structure of the chlorinated vinyl chloride resin is 30.0 mol%. the following. The method for producing a chlorinated vinyl chloride resin according to claim 1 or 2, wherein the chlorinated vinyl chloride resin has a UV absorbance of 0.8 or less at a wavelength of 216 nm. The method for producing a chlorinated vinyl chloride resin according to claim 1 or 2, wherein the time required for the amount of dechlorination of the chlorinated vinyl chloride resin to reach 7000 ppm at 190 ° C is 50 seconds or longer. A method for producing a chlorinated vinyl chloride resin, wherein the chlorinated vinyl chloride resin 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, -CHCl - 46.0 mol% or more, and -CH ₂ - is 37.0 mol% or less, and the production method is characterized in that chlorine is used after the chlorinated vinyl chloride resin reaches a final chlorine content of 5% by weight. The consumption rate (chlorine consumption per 5 kg of raw material vinyl chloride resin) is chlorinated in the range of 0.015 to 0.020 kg/PVC-Kg‧5 min, and the time at which the final chlorine content is still 3% by weight is reached. Thereafter, chlorination was carried out in a range of 0.005 to 0.015 kg/PVC-Kg‧5 min, which is slower than the chlorine consumption rate and the chlorine consumption rate (the chlorine consumption per 5 kg of the raw material vinyl chloride resin). The method for producing a chlorinated vinyl chloride resin according to claim 6 of the invention, wherein the chlorinated vinyl chloride resin has a molecular structure of -CCl ₂ -16.0 mol% or less, and -CHCl- is 53.5 mol % or more, and -CH ₂ - is 30.5 mol% or less. The method for producing a chlorinated vinyl chloride resin according to claim 6 or 7, wherein the vinyl chloride unit of the chlorinated vinyl chloride resin has a tetramethyl or higher vinyl chloride unit content of 18.0 mol%. the following. A method for producing a chlorinated vinyl chloride resin according to claim 6 or 7, wherein the chlorinated vinyl chloride resin is UV-absorbed at a wavelength of 216 nm. The luminosity is 8.0 or less. The method for producing a chlorinated vinyl chloride resin according to claim 6 or 7, wherein the time required for the amount of dechlorination of the chlorinated vinyl chloride resin to reach 7000 ppm at 190 ° C is 100 seconds or longer. The method for producing a chlorinated vinyl chloride resin according to any one of claims 1, 2, 6 or 7 wherein the liquid chlorine or the liquid chlorine is used in a state in which the vinyl chloride resin is suspended in an aqueous solvent. Gaseous chlorine is introduced into the reactor for chlorination. The method for producing a chlorinated vinyl chloride resin according to the eleventh aspect of the invention, wherein the chlorination is carried out without ultraviolet irradiation, and the combination with the hydrogen peroxide to carry out the combination of the vinyl chloride resin and the excitation of the chlorine. A molded article obtained by molding a chlorinated vinyl chloride resin in a method for producing a chlorinated vinyl chloride resin according to any one of claims 1 to 12.