JPS63145305A - Preparation of chlorinated vinyl chloride resin - Google Patents

Abstract

PURPOSE:To prepare a chlorinated vinyl chloride resin providing a molten product which is sparingly colored and retains a good transparency when heated, by chlorinating a vinyl chloride resin while a mixture of the resin and chlorine is irradiated with light containing ultraviolet rays of a specified wavelength or longer. CONSTITUTION:A vinyl chloride resin is chlorinated while a mixture of the resin and chlorine is irradiated with light containing ultraviolet rays not including those having wavelengths less than 340nm. It is preferable that light containing such ultraviolet rays be applied to a suspension of the mixture of the resin and chlorine in an aqueous medium, because the resulting chlorinated vinyl chloride resin is sparingly colored when heated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for producing chlorinated vinyl chloride resin. An object of the present invention is to obtain a chlorinated vinyl chloride resin which, when heated, produces a melt with little coloration and good transparency.

(Conventional technique WI) Chlorinated vinyl chloride resin (hereinafter referred to as CPVC) is vinyl chloride resin (hereinafter referred to as PvC)
It is made by chlorinating. CPVC is a resin that maintains the advantages of PvC while improving the disadvantages of PVC, and is therefore being used in a variety of fields. Specifically, CPVC retains the excellent properties of PvC, such as weather resistance and chemical resistance. Furthermore, CPVC has a heat distortion temperature 20-40°C higher than PVC. Jutte, PVC is 60-
CP softens and cannot be used at temperatures above 70°C.
VC has improved properties such that it can be used at temperatures close to 100°C. Therefore, cpvc is Pv
It is about to be used in a wider variety of fields than C.

However, conventional CPVC was not suitable for new uses. Because conventional cp
This is because when VC was heated for molding in order to be used for such purposes, CPVC was colored yellow and could not become colorless and transparent. In other words, new applications require colorless and transparent materials such as transparent plates, nameplates, and electrical insulation sheets used for industrial purposes, and conventional CPVC can be used to create such items. When heated, it was already colored yellow and could not become transparent, which limited its use. Therefore, it has been desired to provide CPVC that is colorless and transparent without being colored when heated.

In addition, CPVC is made by chlorinating PVC as mentioned above, but if chlorination is performed while irradiating ultraviolet rays, the chlorination reaction will be accelerated and the efficiency will increase.
It is known that PVC can be obtained. Therefore, chlorination of PvC under ultraviolet irradiation has been practiced. However, selecting and using ultraviolet rays with specific wavelengths from among ultraviolet rays has not been done until now. Furthermore, it was not well known what kind of improved characteristics the obtained CPVC would have if the chlorination reaction was carried out while irradiating with ultraviolet rays.

(Problems to be Solved by the Invention) In response to the above-mentioned needs, the present invention seeks to provide a CPVC that does not become colored when heated and is colorless and transparent.

(Means for Solving the Problem) The inventor has improved the process of chlorinating PvC to make CPVC, thereby reducing coloring caused by heating.
In an attempt to obtain a CPVC that would give a colorless and transparent molded product,
We tried various experiments. As a result, if a component with a particularly long wavelength is selected from ultraviolet rays and PVC is chlorinated while being irradiated with this component, the resulting CPVC will reduce the coloring caused by heating and will become a colorless and transparent molded product. I found out.

That is, until now, it was only known that the chlorination reaction of PvC is accelerated when it is irradiated with light having a wavelength generally called ultraviolet rays. The wavelength is 84Qn from ultraviolet rays.
It has been found that when PvC is chlorinated while irradiating ultraviolet rays with a wavelength of m or more, the resulting CPVC is less likely to be colored by heating, and a colorless and transparent molded article can be obtained. This invention was thus born based on the knowledge of the relationship between the wavelength of ultraviolet rays and the properties of the obtained resin.

This invention selects a light ray that contains ultraviolet rays excluding ultraviolet rays with a wavelength of less than 340 nm from among the rays,
The present invention relates to a method for producing a chlorinated vinyl chloride resin, which comprises irradiating a mixture of the vinyl chloride resin and chlorine with a selected light beam to chlorinate the vinyl chloride resin.

This invention requires that ultraviolet rays having a wavelength of less than 340 nm be excluded from the light beam, and a beam containing the remaining ultraviolet rays is used. In the first place, ultraviolet rays are a general term for light rays whose upper limit is 400-380 nm, which is the shortest wavelength limit among visible light rays, and whose lower limit is about 1 nm. This invention is based on the wavelength of 8 among such light rays.
Use one that excludes ultraviolet rays of less than 40 nm. That is, the light rays used in the present invention include ultraviolet rays having a wavelength of 340 nm or more and 400 nm or less, and visible rays that are in contact with the ultraviolet rays. Among ultraviolet rays, ultraviolet rays with a wavelength of 300 nm or more are called near ultraviolet rays, but in this invention, only a part of the near ultraviolet rays with longer wavelengths are used as ultraviolet rays.

Various methods can be used to generate ultraviolet light. Ultraviolet rays of a single wavelength can be obtained directly using a laser beam, but when other light sources are used, ultraviolet rays of various wavelengths can be obtained as a mixture. As light sources, iron or carbon arc lamps, thorium bulbs, flashlight bulbs, high or low pressure mercury lamps, underwater spark discharges, hydrogen discharge lamps, xenon discharge lamps, helium discharge tubes, Lyman spark discharges, etc. can be used. In addition, sunlight can also be used in this invention.

In the case of ultraviolet rays obtained by mixing UV rays with various wavelengths, it is necessary to remove those with short wavelengths of less than 340 nm. For this purpose, a filter for transmitting ultraviolet light is used to absorb and remove light with a wavelength of less than 340 nm. Ultraviolet transmission filters that selectively absorb ultraviolet rays within a specific wavelength range are commercially available, and it is convenient to use such filters.

The reason why this invention excludes ultraviolet rays having a wavelength of less than 3 AOnm is based on the results of experiments. That is, by removing ultraviolet rays with a wavelength of less than 340 nm,
This is based on the fact that when chlorinated while being irradiated with ultraviolet rays of m or more, the obtained CPVC has no initial coloration upon heating and melts to give a colorless and transparent molded body.

Furthermore, based on the fact that when irradiated with ultraviolet rays including ultraviolet rays with a wavelength of less than 340 nm, the obtained CPVC will have an initial coloration, and therefore a colorless and transparent molded product will not be obtained. There is.

This invention uses conventional chlorination methods as is, except for the intention of using ultraviolet light with a wavelength of 340 nm or more. That is, in general, chlorination of PvC can be carried out in a gas phase state or a liquid phase state, and the present invention is no exception to this, and chlorination can be carried out in either state.

As an example, the case of chlorination in a liquid phase will be explained as follows. First, PVC powder and an aqueous medium are placed in a reaction vessel and stirred to form a suspension, and an inert gas is blown into the vessel to drive out oxygen within the reaction vessel.

Next, chlorine is pressurized into the suspension thus obtained to maintain the inside of the container at an appropriate temperature. At this time, an ultraviolet light source is provided in the container and the suspension is irradiated with ultraviolet rays of the above wavelength. Then, PvC is gradually chlorinated to become cpvc. In this way, when PvC is chlorinated in a suspended state, the resulting CPVC becomes less colored, especially when heated.

The aqueous medium mentioned above is not limited to water, but may be water with an organic solvent added. As the organic solvent, chloroform, carbon tetrachloride, dichloroethane, etc. can be used. There is something like this! When water containing a ll solvent is used, PVC can be chlorinated in a swollen state with an organic solvent. When chlorinated in this swollen state, there is an advantage that the whole can be uniformly chlorinated in a short time.

Chlorination is discontinued when the resulting CPVC is considered to have the desired chlorine content. At this point, Pv
The chlorination process of C can be estimated from graphs showing the relationship between temperature and time.

CPVC yields a chlorine content in the range of 57-74% by weight, depending on the degree of progress of the chlorination reaction. Preferred among these is CPVC with a chlorine content of 60-70% by weight.

The PvC of the raw materials that can be used in this invention is:
It is not limited to vinyl chloride homopolymers. That is, it may be a copolymer of vinyl chloride and other monomers. Other monomers include, for example, vinyl chloride, sodan, α-olefins such as ethylene and propylene, acrylonitrile, vinyl acetate, vinyl stearate, acrylic esters, methacrylic esters, and alkyl vinyl ethers.

PvC may be polymerized by any method. In addition, PVC is
As described in Japanese Patent No. 3806, it may be polymerized using a modifier. Further, it is particularly preferable that PvC has a viscosity average degree of polymerization within the range of 300-3000.

When making the cpvc thus obtained into a molded body, cpvc
Add various additives to vc. Additives include stabilizers, lubricants, processing aids, reinforcing agents, antioxidants, ultraviolet absorbers, plasticizers, dyes, pigments, and the like. Among these, the stabilizer is CPV
From the viewpoint that C does not become colored in the initial stage of heating and maintains transparency, organic tin compounds are suitable, and dialkyltin sulfur-containing compounds are particularly suitable. For example, TVS #8B31 manufactured by Nitto Kagaku Co., Ltd., 0T-4 manufactured by Tokyo Fine Chemical Co., Ltd., or 0NZ manufactured by Sankyoki Gosei Co., Ltd.
This is a compound called -41F. Such dialkyltin sulfur compounds have a CPVC of 0.5-5
Preferably, it is expressed as % by weight.

Examples of lubricants include polyethylene waxes, higher fatty acid esters such as stearin monoglyceride,
Higher alcohols such as stearyl alcohol and higher fatty acids such as stearic acid can be used. As a processing aid, for example, Metablen P manufactured by Mitsubishi Rayon Co., Ltd.
Acrylic compounds such as 501 and P2O3 can be used. As the reinforcing agent, for example, methyl methacrylate/butadiene/styrene terpolymer, ethylene/vinyl acetate copolymer, or the like can be used. As the antioxidant, for example, a hindered phenol compound can be used. As the ultraviolet absorber, for example, benzotriazole compounds can be used. As the plasticizer, for example, phthalate esters such as dioctyl phthalate, adipic esters such as dioctyl adipate, and those known as polyester plasticizers can be used.

(Effects of the Invention) According to the present invention, ultraviolet rays having a wavelength of 340 parts m are selected except for the ungrooved ultraviolet rays, and the mixture of vinyl chloride resin and chlorine is irradiated with the selected ultraviolet rays to chlorinate the mixture of vinyl chloride resin and chlorine. Since the vinyl resin is chlorinated, the obtained CPVC has little initial coloring when heated, and when it is melted to form a molded product, the molded product becomes colorless and transparent. Therefore, vinyl chloride resin has good weather resistance and chemical resistance, but it is used in fields where vinyl chloride resin lacks heat resistance, and in addition, it is required to be colorless and transparent. Until now, there has been no product in the field that satisfies these requirements, but the present invention can provide a product that satisfies these requirements, and exhibits great value in this respect.

Examples and comparative examples will be given below to clarify the reason why this invention limits the wavelength of ultraviolet rays to 340 parts m or more, and to explain why this invention is superior. In the following, parts simply mean parts by weight. In addition, in the Examples and Comparative Examples, initial coloring is measured, but the measurement is based on evaluating the yellowness difference ΔN from a standard white board using a color difference meter manufactured by Nippon Denshoku Industries Co., Ltd. It is.

Example 1 PV with an average degree of polymerization of about 600 made by suspension polymerization method
The CIQQ portion and 500 parts of ion-exchanged water were placed in a reaction vessel and stirred to suspend PVC in the water, and then nitrogen gas was blown into the vessel to drive out oxygen within the vessel. Thereafter, the suspension was maintained at 70°C, chlorine gas was introduced into it, and the chlorination reaction was started while irradiating the suspension with sunlight that had passed through an ultraviolet transmission filter. As a filter, an ultraviolet transmission filter UV-36 manufactured by HOYA Co., Ltd. was used, and ultraviolet rays having a wavelength of less than 340 nm were removed using this filter for irradiation.

In this way, the chlorination reaction was carried out for about 6 hours, and the chlorine content was reduced to 6.
5% by weight of CPVC was obtained. After removing chlorine and hydrochloric acid remaining in the CPVC, it was dehydrated and dried. This drying c
2 parts of dioctyltin sulfur-containing compound (TVS#8881 manufactured by Nitto Chemical Co., Ltd.) as a stabilizer to PVC, and 0.5 part of Metaprene L-1000 (manufactured by Mitsubishi Rayon Co., Ltd.) as a processing aid.
As lubricants, 0.2 parts of Hiwax 4202E (manufactured by Mitsui Petrochemicals) and 0.2 parts of F-3 (manufactured by Yoken Fine Chemicals) were used.
8 parts and 5 parts of Kane Ace B-11A (manufactured by Ichifuchi Kagaku Co., Ltd.) as a reinforcing agent were added and mixed well. This mixture was kneaded using a 6-inch roll at 80°C for 5 minutes to obtain a rolled sheet. This rolled sheet was pressed at 180° C. for 10 minutes to obtain a pressed plate. When the initial coloring of this press plate was measured, ΔN was 38.

It has been found that this results in less initial coloring and therefore produces a molded article with good transparency.

Example 2 CPVC with a chlorine content of 65% by weight was obtained after 6 hours of chlorination reaction by performing exactly the same operation as in Example 1, except that a high-pressure mercury lamp was used instead of sunlight. Ta.

A pressed plate was made using this CPVC in exactly the same manner as in Example 1, and when the initial coloring of this pressed plate was measured, a value of 87 was obtained for ΔN.

It was confirmed that this gave a transparent molded product with little initial coloring.

Example 3 L instead of UV-36 as ultraviolet transmission filter
The chlorination reaction was carried out in exactly the same manner as in Example 2, except that ultraviolet rays with a wavelength of less than 370 nm were removed using UV-40, and therefore, a light beam containing ultraviolet rays with a wavelength of 370 nm or more was used. After an hour's chlorination reaction, a CPVC with a chlorine content of 65% by weight was obtained.

This CPVC was treated in exactly the same manner as in Example 1 to produce a pressed plate, and when the initial coloration of this pressed plate was measured, a value of 39 was obtained for ΔN.

It has been found that this results in less initial coloring and therefore provides a transparent molded product.

Comparative Example 1 The same operation as in Example 1 was carried out, except that sunlight was used as it was without using an ultraviolet transmission filter, and after 6 hours of chlorination reaction, the chlorine content was reduced to 6.
5% by weight of CPVC was obtained.

Using this CPVC, it was subjected to exactly the same operations as in Example 1 to obtain a pressed plate. When the initial coloring of this press plate was measured, ΔN was 46. As a result, it was found that the initial coloring was large and therefore a colorless and transparent molded product could not be obtained.

Comparative Example 2 U instead of UV-36 as a filter for ultraviolet transmission
The chlorination reaction was carried out in the same manner as in Example 2, except that the light from the high-pressure mercury lamp was filtered using V-32 and a light beam containing ultraviolet light with a wavelength of 300 nm or more was used. After 6 hours, a CPVC with a chlorine content of 65% by weight was obtained.

Using this CPVC, a pressed plate was obtained by processing in exactly the same manner as in Example 2. When the initial coloring of this press plate was measured, a value of 44 was obtained as the value of ΔN. As a result, it was found that when irradiated with a light beam containing an excess of ultraviolet light having a wavelength of 300-340 nm, the initial coloring was large and, therefore, a colorless and transparent molded product could not be obtained.

Patent applicant: Tokuyama Sekisui Kogyo Co., Ltd. Procedural amendment December 16, 1986 2. Name of the invention Method for producing chlorinated vinyl chloride resin 2-4-4 Nishitenma, Kita-ku, Osaka City Tokuyama Sekisui Kogyo Co., Ltd. 4. Agent & Target of correction Detailed description of the invention in the specification 6. Contents of amendment On page 15, line 15 of the specification, "80℃" There is a certain "180℃" Correct.

that's all

Claims (1)

[Claims] 1. Chlorinating the vinyl chloride resin while irradiating the mixture of the vinyl chloride resin and chlorine with a light beam that contains ultraviolet rays excluding ultraviolet rays with a wavelength of less than 340 nm. A method for producing a chlorinated vinyl chloride resin, characterized by: 2. Chlorination according to claim 1, characterized in that a mixture of vinyl chloride resin and chlorine is suspended in an aqueous medium and irradiated with light containing ultraviolet rays. A method for producing vinyl resin. 3. The chlorinated vinyl chloride resin according to claims 1 and 2, characterized in that ultraviolet rays with a wavelength of 340 nm or less are removed from the light beam using a glass filter for transmitting ultraviolet rays. Production method.