JPS604032A - Antistatic plastic welding bar - Google Patents

Abstract

PURPOSE:To make unattractive the seams of light-color sheets when welded by adding a conductive oxide, e.g., zinc oxide, titanium oxide, etc., to the termoplastic resin of a welding bar for plastic sheets subjected to an antistatic treatment. CONSTITUTION:A conductive zinc oxide, for example, is obtained by baking a mixture of 100mol% zinc oxide and 0.05-5mol% an organoaluminium compound containing aluminium atom at a temperature of 800-1,100 deg.C and then finely grinding the mixture so baked. The conductive zinc oxide so obtained is a white powder having a low intrinsic resistivity of several ohm.cm in general, exerting no influence on coloration. The addition of the white powder and a colorant in appropriate amounts to a welding bar makes it not only light-color but also any desired clear color.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an antistatic material that is suitably used when welding plastic sheets that contain conductive oxide powder particles to reduce the overall resistivity in order to obtain an antistatic effect. Regarding highly effective plastic welding rods.

In recent years, synthetic resin sheets with decorative patterns have been widely used as flooring and wall covering materials, but as is well known, the polyvinyl chloride resin sheets that serve as the base material for this type of material are susceptible to frictional static electricity. Since it is easily charged, it has various problems such as a large amount of dust adhering to it, and when the amount of charge increases, it may discharge to the human body and give an electric shock.

In order to deal with these problems, conventional methods have been developed. A method of incorporating carbon black, which is a carbonaceous material, has generally been adopted.

However, the fcT&) method described above has the disadvantage of durability in that the coating layer of the antistatic agent wears out within a relatively short period of time and loses its antistatic effect. Although it has good durability, there are significant restrictions on the type and amount of antistatic agent used due to moldability.
In reality, it is difficult to sufficiently reduce the volume resistivity of the plastic sheet, and a satisfactory antistatic effect cannot be expected.Furthermore, the above method (0) requires a large amount of carbon black. Therefore, there is no problem when manufacturing black-based plastic sheets, but when coloring other colors, the color may be darkened and dirty, or the color may be bright and pale. There was a drawback that it was impossible to color the basolateral color (for example, pale yellow, yellow, yellow-green, pale green, pale blue, pale pink, pink, pink-red, white, etc.).

Therefore, in order to solve such problems, the applicant has
Previously, Japanese Patent Application No. 56-205624 and Japanese Patent Application No. 57-
No. 229110 proposed an antistatic plastic sheet containing a conductive oxide in the plastic sheet.

According to the antistatic plastic sheet according to this proposal, a greater antistatic effect can be obtained, and the conductive oxide contained does not adversely affect the coloring of pale blue to white powder particles, making it colorful. This has the advantage that the pattern can be colored.

The object of the present invention is to provide a welding rod which is used in particular for welding plastic sheets which have been subjected to such antistatic treatment.

That is, the welding rod of the present invention contains 70 to 90% by weight of a conductive oxide such as conductive zinc oxide, conductive titanium oxide, conductive tin oxide, and conductive antimony oxide in a thermoplastic resin. This article relates to an antistatic plastic welding rod, in which the conductive oxide particles contained inside the resin are all completely chained or non-conductive with partially missing parts within a few angstroms. It is thought that a complete chain is formed, and this complete or incomplete chain is used as a conductive path to release frictional static electricity to the outside, thereby exhibiting a good antistatic effect.

Among the conductive oxides used to form the welding rod of the present invention having such characteristics, conductive zinc oxide is zinc oxide (preferably one with a semi-average particle size of 0.1 to 1.θμ). )
A mixture of 0.06 to 6 moles of an organoaluminum compound containing an aluminum atom (e.g., aluminum salt of carboxylic acid, aluminum alkoxide, aluminum complex salt, etc.) per 100 moles of aluminum is mixed at a ratio of about 800 to 600 moles. The conductive zinc oxide obtained in this way is generally manufactured by heating and firing at a temperature of °C and then pulverizing, or by a similar method. It is a white powder that has a low resistivity of Ωcm and does not affect the coloring, so by mixing an appropriate amount of coloring agent with it, the welding rod of the present invention can be made into a bright light color. It is possible to color it in any desired vivid color.

Conductive titanium oxide is a combination of titanium and titanium oxide at 1560
It can be produced by heating and firing at ~1750°C (vacuum) and then pulverizing, or by a similar method. In addition, conductive tin oxide and conductive antimony oxide are manufactured by igniting naturally occurring ores such as cassiterite and nantimony tetroxide in air, or by a similar method. All of these generally form light blue to white powder grains having a low resistivity of several Ω·ω to several tens of cm.

Like Jin, the above-mentioned conductive oxides are pale blue to white powder particles that have no negative effect on coloring, so by kneading an appropriate amount of coloring agent, bright pale colors can be created. It is possible to color the material in any desired vivid color.

However, as mentioned above, the content of such conductive oxide is 70 to 90% of the total weight of the antistatic welding rod.
#, it is desirable to make it about a row.

Generally, the volume resistivity of thermoplastic synthetic resin is ・lO~l
If the content of the conductive oxide is about 0Ω・cm, it will exhibit a good antistatic effect.If the content of the conductive oxide is less than 70% by weight, the volume resistivity of the welding rod will be larger than the above range and will be good. It becomes difficult to exhibit the antistatic effect9, and conversely, if the weight exceeds 90 weight tφ, it becomes easy to break during operation, making it difficult to put it into practical use as a welding rod.

Furthermore, when the content of conductive oxides, etc. is less than 70 mm, the volume resistivity increases and good antistatic effect cannot be obtained because of the lack of conductive oxides. It is inferred that this is because the above-mentioned complete or incomplete series #J, which serve as a conductive path for the static conductor 114A, are not sufficiently formed inside the plastic sheet.

The welding rod of the present invention is produced by blending appropriate amounts of various auxiliary materials such as plasticizers, stabilizers, and colorants with the thermoplastic resin as the main material, as well as the above-mentioned blending of conductive oxides such as conductive titanium oxide. It is manufactured by mixing and kneading to prepare a material and molding this material using a desired molding method such as an extrusion mold.In the case of jin, polyvinyl chloride is used as the main thermoplastic resin. Thermoplastic resins that are easily charged, such as resins, polyethylene resins, polypropylene resins, ethylene vinyl acetate copolymer resins, polymethyl methacrylate resins, polycarbonate resins, -bonate resins, and cellulose resins can also be used.69 Also, plasticizers can be used. It goes without saying that any of the various auxiliary materials commonly used in conventional thermoplastic resins can be used for auxiliary materials such as stabilizers and colorants.

As described above, the welding rod of the present invention contains a conductive oxide, which is considered to form a complete or incomplete chain as a conductive path for static electricity, throughout the inside of the thermoplastic resin. Even if the plastic sheets are welded together by heating and melting into the grooves formed in the adjacent parts of the plastic sheets in the same way as a welding rod, the antistatic effect will not be impaired. In addition, since the contained conductive oxide is a pale blue to white powder particle that does not have a negative effect on coloring, it is possible to color the desired vivid color by mixing an appropriate amount of colorant. Therefore, even when welding light-colored plastic sheets, the joints will not be noticeable.

The antistatic plastic welding rod of the present invention having these advantages is particularly desirable for use as a welding rod for the above-mentioned antistatic plastic sheet proposed by the applicant. It is used in places where durability and strict antistatic properties are required, such as floor coverings in chemical factory laboratories and hospital operating rooms, or as coverings for assembly workbenches of electronic equipment and precision machinery. It is extremely useful for use as a welding rod for antistatically treated plastic sheets.

Next, examples will be given.

(Example 1) 100 parts of polyvinyl chloride resin (parts by weight, same below), D
OP5Q part, 3 parts of stabilizer, 400 parts of conductive zinc oxide, and 1 part of pigment (phthalocyanine mixed pigment) are kneaded and extruded to form an antistatic product with a content of conductive titanium oxide of about 72 x 1 volume. A rod-shaped body (outer diameter 3 sieves) of polyvinyl chloride resin was produced.

The obtained welding rod has a clear, bright blue-green color, and its volume resistivity is approximately 1070 cm.
+ indicates good antistatic properties.

(Example 2) Fi Example 1 except that the amount of conductive zinc oxide was changed to 600 parts
In the same manner as above, a rod-shaped body of antistatic polyvinyl chloride resin having a conductive zinc oxide content of about 80% by weight was obtained.

As in Example 1, the obtained welding rod exhibited a bright blue-green color without clouding, and its volume resistivity was approximately 1.
Good antistatic properties were exhibited at 060 cm.

(Example 3) The conductive titanium oxide content was about 80 parts by weight in the same manner as in Example 1 except that the amount of conductive zinc oxide was changed to 800 parts and 1 part of Bengara pigment was added as a coloring agent. A rod-shaped body of antistatic polyvinyl chloride resin was manufactured.

The obtained welding rod had a bright red color without turbidity, and exhibited excellent antistatic properties with its volume resistivity hto'Ω·cIIl (Example 4) 100 parts of polyvinyl chloride resin (parts by weight, same below),
3 parts of DOP5Gms stabilizer, 400 parts of conductive titanium oxide, and 1 part of pigment (phthalocyanine-based mixed pigment) were kneaded and extruded to give a content of conductive titanium oxide of approximately 72 weight φ.
Rod-shaped body of antistatic polyvinyl chloride resin (outer diameter 3 mm)
was manufactured.

The obtained welding rod has a bright blue-green color with no cloudiness, and its volume resistivity is approximately 1070 cm.
It exhibited good antistatic properties.

(!l! Example 6) Example 1 except that the amount of conductive titanium oxide was changed to 600 parts.
Similarly, the content of conductive titanium oxide is approximately 80% by weight.
Obtained a rod-shaped body made of antistatic polyvinyl chloride resin.

As in Example 1, the obtained welding rod has a bright blue-green color without any clouding, and its volume resistivity is approximately 1.
Exhibits good antistatic properties at 0'Ω・Cl11.

(Example 6) The content of conductive titanium oxide was about 84 parts by weight in the same manner as in Example 1 except that the amount of conductive titanium oxide was changed to 800 parts and Bengara pigment Iku was added as a coloring agent. A rod-shaped body of antistatic polyvinyl chloride resin was manufactured.

The obtained welding rod had a bright red color with no turbidity, and its volume resistivity was 10 5 Ω·cm, exhibiting excellent antistatic properties.

Note that although examples using conductive tin oxide and conductive antimony oxide are omitted, the same effects as in the above examples were obtained.

Patent applicant Takiron Co., Ltd. Representative Ryutabe Heki demon

Claims (2)

[Claims] (1) An antistatic plastic welding rod characterized by containing a conductive oxide such as conductive zinc oxide, conductive titanium oxide, conductive tin oxide, or conductive antimony oxide in a thermoplastic resin. (2) The content of the conductive oxide is 70 to 90% of the total content.
% by weight of the antistatic plastic welding rod according to claim 1.