JPS5975940A - Production of vinyl chloride polymer composition - Google Patents

Abstract

PURPOSE:To obtain the titled compsn. suitable for use as an electromagnetic shielding material and having excellent moldability, etc., by mixing a carbon black-contg. PVC with an emulsion-polymerized PVC have a degree of polymerization higher than that of the above PVC. CONSTITUTION:At least 5wt% carbon black such as furnace black is uniformly dispersed in vinyl chloride monomer. The monomer is polymerized by bulk polymn. or suspension polymn. to prepare carbon black-contg. vinyl chloride polymer having an average degree of polymn. of 400 or above, 3-100pts.wt. emulsion- polymerized vinyl chloride polymer having a higher degree of polymn. than that of said carbon black-contg. polymer and opticonally stabilizer, plasticizer, reinforcing agent, etc. are mixed with 100pts.wt. (excluding the quantity of carbon black) said carbon black-contg. vinyl chloride polymer to obtain the desired vinyl chloride polymer compsn.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a vinyl chloride polymer composition containing carbon black.

In recent years, there has been increasing interest in conductive plastics for use in electronics-related equipment and electromagnetic shielding materials that require antistatic properties. Furthermore, carbon black is the most commonly used conductive material, except for special applications where transparency is required, because it is less expensive than other materials.

However, materials made of vinyl chloride polymer as a conductive plastic with carbon blanks dispersed therein cannot be used for purposes other than soft materials containing a large amount of plasticizer.
Although K is suitable for precision molding due to its dimensional stability of molded products and is relatively inexpensive, its use is currently extremely limited.

The reasons for this are, firstly, that the decomposition temperature of vinyl chloride polymer is low, so it is impossible to mold it in the low melt viscosity region like other polymers, and secondly, it is necessary to obtain conductivity. In order to achieve this, it is generally necessary to blend 8 to 15 percent by weight or more of carbon black, and in order to uniformly disperse it in the polymer, K requires a considerable amount of mixing time, resulting in heat generation and decomposition of the polymer. There are some things that cannot be overlooked. Also, as can be said for any polymer, blending with a polymer is extremely difficult for carbon black, especially carbon black for conductive materials, whose bulk specific gravity is extremely small and individual particles are around several hundred angstroms. , and the working environment.”
- This is a task that is often avoided by people.

On the other hand, adding vinyl chloride and carbon black
After mixing, it is also possible to polymerize to obtain a vinyl chloride polymer containing carbon blank, but if the vinyl chloride polymer containing carbon black has a high degree of polymerization, the above-mentioned stage of vinyl chloride polymer However, the range of molding conditions cannot be said to be wide due to the large amount of heat generated by crosstalk, and if the degree of polymerization is low, the mechanical strength of the molded product is even lower. There are restrictions on usage.

As a result of intensive research in order to solve the above-mentioned problems, the present inventors have discovered that carbon black is uniformly dispersed in vinyl chloride monomer or is wetted with vinyl chloride monomer and then suspended in an aqueous medium. , or a carbon black-containing vinyl chloride polymer K obtained by polymerizing a vinyl chloride monomer by a bulk polymerization method, and a vinyl chloride polymer obtained by an emulsion polymerization method K to a higher degree of polymerization than the vinyl chloride polymer. Therefore, there is no need for processing steps such as pre-mixing to uniformly disperse carbon black, and there is no decomposition of the vinyl chloride polymer due to long-term cross-wiring, etc., and the carbon has excellent processability and is suitable for extrusion molding, injection molding, etc. A black-containing vinyl chloride polymer composition was obtained, leading to the present invention. That is, the present invention combines a carbon black-containing vinyl chloride polymer obtained by adding carbon black to a vinyl chloride monomer and adding a small amount of a vinyl chloride polymer obtained by an emulsion polymerization method having a higher degree of polymerization than the vinyl chloride polymer. This is a method for producing a vinyl chloride polymer composition, which comprises mixing.

The carbon black-containing vinyl chloride polymer used in the present invention is Funesz Rank! Mixing carbon black produced by each TTG manufacturing method such as thermal black, channel black or graphite (hereinafter collectively referred to as carbon black) with vinyl chloride monomer or vinyl chloride monomer and other heptamers copolymerized with the monomer. monomer(
In the present invention, it is also simply a polymer obtained by uniformly mixing and dispersing the vinyl chloride monomer in (5) vinyl chloride monomer and then polymerizing it by bulk polymerization or turbidity polymerization. Other heptamers that can be copolymerized with vinyl chloride include olefin compounds such as ethylene and propylene; vinyl esters such as vinyl acetate and vinyl propionate; unsaturated carboxylic acids and their esters such as acrylic acid and methacrylic acid. salts; Acrylic I: l2)! J
and vinyl halides excluding vinyl chloride such as vinylidene chloride, but are not limited to these.

Next, in the present invention, the vinyl chloride polymer having a higher degree of polymerization than the vinyl chloride polymer to be mixed with the carbon black-containing vinyl chloride polymer is a vinyl chloride monomer alone or a monomer copolymerizable with vinyl chloride monomer. In this case, carbon blank-containing vinyl chloride polymer (6) is added and mixed in advance to the monomer and emulsion polymerized in the same manner. In addition, a vinyl chloride polymer with a high degree of polymerization) may also be used.

In the present invention, the blend ratio of the carbon black-containing vinyl chloride polymer obtained by suspension polymerization or bulk polymerization to the vinyl chloride polymer obtained by the emulsion polymerization method and having a higher degree of polymerization than the vinyl chloride polymer is the carbon black contained in the vinyl chloride polymer. Excluding the minute(・
If the ratio of the vinyl chloride polymer component is 100 parts by weight of the former suspension polymerized or bulk polymerized carbon 7-lacquer-containing polymer, the latter high polymerization degree vinyl chloride polymer obtained by emulsion polymerization is 100 parts by weight or less. Preferably, L < is 3 parts by weight or more, and generally 10 to 30 parts by weight.

When molding a vinyl chloride polymer with a high degree of polymerization obtained by emulsion polymerization within this range and blending it with a carbon blank-containing vinyl chloride polymer obtained by suspension or bulk polymerization, emulsion 1
``Even if the average degree of polymerization of the polymers obtained by polymerization significantly exceeds the average degree of polymerization of the vinyl chloride polymers constituting the carbon black-containing vinyl chloride polymer obtained by M turbidity or bulk polymerization, they will not easily gel. Therefore, the average degree of polymerization of both is not limited at all, but the average degree of polymerization of the former carbon black-containing vinyl chloride polymer is generally 400 or more.The average degree of polymerization referred to in the present invention is based on JISK-6721, and copolymers are also expressed as the viscosity average degree of polymerization converted to vinyl chloride homopolymer from the viewpoint of viscosity. Ta.

In particular, in order to use the vinyl chloride polymer composition obtained by the present invention as a conductive material, the VC may be adjusted so that the carbon black content is generally 5% by weight or more.

In addition, adding stabilizers, plasticizers, rubber components such as MBS, various reinforcing agents such as chlorinated polyethylene EVA, or adding carbon flanks to these carbon black-containing vinyl chloride polymers, etc. It goes without saying that scales, which are added during the molding process of ordinary vinyl chloride polymers, are also used in the same way.

Hereinafter, polymerization data of carbon black-containing vinyl chloride polymers and examples of blends of these carbon blank-containing vinyl chloride polymers will be shown, but the present invention is not limited to these examples in any way.

A polymerization iron having a polymerization internal volume of 65 liters as Sample I61 was used. After sufficiently drying the inner wall of the polymerization iron, 2 was charged into Ketjen Black EC (manufactured by Lion Akzo Co., Ltd.) 15, and after replacing the inside of the polymerization iron with nitrogen, the pressure was reduced to 70 H9 and vinyl chloride monomer 15, oKp introduced. After stirring for 20 minutes, 20 g of Gohsenol KH-20 (2-partly saponified polyvinyl acetate manufactured by Nippon Gosei Kagaku Kogyo @) and Metruze 90SH-1 were added.
00 (Shin-Etsu Chemical (9) Kogyo @) ff, 35 liters of deionized water in which 30 g of hydroxypropyl methyl cellulose) was dissolved and 38.5 F of Diimp P Bilver Oxin Carbone) were introduced into the polymerization iron. Polymerization was carried out at 57.5°C with stirring, and the pressure inside the end was about 1.5°C. OKy/cl decreases, q, sKy/
When the volume decreased to Cl, unreacted monomers were purged, and the polymer slurry was dehydrated using a centrifugal dehydrator and dried. The polymerization time was 5 hours and 5 minutes. Polymer is 100 mesh bath 88.1
%, bulk specific gravity 0.363, carbon black content 15
．． It was a 1% black powder, and the average degree of polymerization of the extracted polymer was 1025.

Sample 42 Polymerization was carried out under the same conditions as Sample/I61 except that the initiator was changed to 7zobisisoptene pnitrile 40.9 and the polymerization temperature was 70°C, and the end pressure was o, sKp/
c++! The polymerization was terminated when the temperature decreased to 11.5 no/d. Polymerization time 5 hours 30 minutes, 100 mesh passes 8
43%, bulk specific gravity 0.361. Carbon blank content 1
A carbon-containing polymer having an average degree of polymerization of 7.2 (10)% and an average degree of polymerization of 665 was obtained.

Sample/163 A polymerization iron with an internal volume of 30 liters and a paddle-type stirrer was used.

After thoroughly drying the inner wall of the polymerization iron, Ketjenblack E C0,7K9 was added and the inside of the polymerization iron was replaced with nitrogen.
70 yam I (pressure reduce to 9 and remove vinyl chloride 7 mA-7
, 0Kfl was introduced. After stirring for 20 minutes, the phosphate ester type 7-ion surfactant Gafac RE-61
0 (manufactured by Toho Chemical Industry @)) 60I! Then, 12 liters of pure water in which 20 g of ammonium persulfate was dissolved was introduced.

Polymerization was carried out at 50° C. for 10 hours with stirring to obtain a carbon black-containing vinyl chloride polymer of black powder with an i of 114.3%. The average degree of polymerization of the polymer component is 13
It was 80.

Examples 1 to 6 and Comparative Examples 1 and 2 Carbon black-containing vinyl chloride polymers of Sample/161 and Scrap 2 obtained by suspension polymerization were added to (11) Table - Carbon black-containing sample 3 obtained by emulsion polymerization A vinyl chloride polymer and Sumilit EX-A (manufactured by Sumitomo Chemical Industries, Ltd.) were blended at the mixing ratios described in each example or comparative example in Table 1. Incidentally, as a stabilizer component, 2.0 parts by weight of diptyltin mercaptan was used per 100 parts by weight of the resin component excluding carbon black.

2.0 parts by weight of epoxy soybean oil and 0.5 parts by weight of stearic acid were added. The mixture was kneaded in a steam pool at 157° C., the time required for winding it around a roll (in seconds) was determined, and after winding, mixing was continued for 5 minutes to create a sheet with a thickness of 1.1 mm. The flow characteristics of a small section of the sheet were measured using a Koka-type flow tester, and the thickness of the sheet was press-processed at 165°C for 20 minutes. The Kratschberg softness temperature and volume resistivity were determined for the OR sheet. The results obtained are shown in Table-IVC
Described. In addition, the flue characteristics are 1. Using the IZIXIO nozzle, the resin flow rate was 2 X I Q Cl! /B
This is the temperature that indicates @c.

(12) From the results of Examples 1 to 4 and Comparative Example 1 or Examples 5 and 6 and Comparative Example 2 in Table 1, it is clear that the emulsion polymerization component is blended with the suspension polymerization component even though the average degree of polymerization is high. As a result, it can be seen that in all Examples, compared to the comparative example in which the emulsion polymerization component was not pre-coated, the μm winding time was shorter, and the flow temperature also tended to be lower, indicating that the moldability was improved. .

On the other hand, the softening temperature is improved due to the blend of emulsion polymerization components with a high degree of polymerization.

On the other hand, the string-like extrudates measured using a flow tester showed a glossy and uniform thickness in all Examples.

However, in the comparative examples, the thickness was uniform, but there was almost no gloss.

It should be noted that the volume resistivity is highly dependent on the amount of carbon nolac contained, and no influence is seen by the blend.

patent applicant Sun Ap Chemical Co., Ltd. (14) 307-

Claims (1)

[Scope of Claims] (1) A carbon black-containing FU vinyl polymer obtained by adding carbon black to a vinyl chloride monomer and polymerizing it by an emulsion polymerization process having a higher degree of polymerization than the vinyl chloride polymer ( A method for producing a vinyl chloride polymer composition (2) characterized by mixing a small amount of a vinyl chloride polymer with f+
) The manufacturing method according to claim 1, wherein the carbon black-containing vinyl chloride polymer has an average degree of polymerization of 400 or more (3) A patent for producing a carbon blank-containing vinyl chloride polymer by a suspension polymerization method or a bulk polymerization method Manufacturing method according to claim 1 (4) Carbon black-containing vinyl chloride polymer (excluding carbon black content)
The manufacturing method according to claim 1, wherein the vinyl chloride polymer composition has a high degree of polymerization (excluding carbon black content) of 3 to 100 parts by weight (5) The carbon black content of the vinyl chloride polymer composition is 5 parts by weight The manufacturing method according to claim 1, which is at least % by weight.