JPS60146100A - Low dustless conductive paper - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a low-dusting conductive paper.

More specifically, after making paper by mixing conductive inorganic powder and/or conductive fibers with cellulose pulp slurry, it is impregnated or coated with a polymer resin content of 10 to 50% by weight. This relates to dusty conductive paper.

In recent years, with the spread of 8' electronic equipment such as computers and digital equipment, and precision electronic equipment parts such as ICs and LSIs, the problems of 6-wave interference and static electricity interference have come into focus. To solve this problem, the emergence of materials with X-X wave shielding properties or anti-static properties has been anticipated. Conventionally, conductive inorganic materials such as cellulose pulp and slurry carbon plaque have been used to produce paper. A method of obtaining by mixing powders and milling, or by impregnating or coating.

Alternatively, a method has been proposed in which charcoal P fibers, gold@fibers, etc. are mixed and extracted.

However, it has been found that these conventionally proposed methods have the following drawbacks. That is,
In the method of mixing, impregnating, or coating paper with conductive inorganic powder such as carbon black, in order to suppress magnetic wave shielding properties or frost 1j electrical properties, it is necessary to:
It is necessary to mix, coat, coat, etc., and the conductive inorganic powder is firmly attached to the layer). There is a risk of causing problems such as destruction.Furthermore, even when conductive fibers are mixed and used, since the conductive fibers themselves do not have binding ability, they are likely to fall off and cause problems.

An object of the present invention is to overcome the drawbacks of the prior art and provide electromagnetic shielding or antistatic properties.

The object of the present invention is to provide a low-dusting conductive paper that eliminates the risk of troubles such as breakdown of insulation by preventing these conductive substances from falling off from the P layer. Examples of the conductive inorganic powder used in the conductive paper of the present invention include carbonaceous powder such as carbon black, metallic powder such as copper, zinc, nickel, tin, and aluminum, and conductive zinc oxide, tin oxide, and antimony oxide. , conductive gold such as titanium oxide 1@
cv compound.

Examples include, but are not limited to, conductive metal compounds such as iodides. The conductive fibers used in the conductive paper of the present invention include carbon fibers, stainless steel, aluminum, and other metal f! am, metallized fibers, which are inorganic fibers with a metal coating on the surface of glass fibers, acrylic fibers containing copper ions, or organic fibers with chemical plating on the surface, and carbon black mixed therein.

There are organic conductive fibers that look like spun yarn.

It is not limited to straw.

5 to 50% by weight of the conductive Th non-porous powder and/or 0.5 to 80% by weight of the conductive fibers are mixed into cellulose pulp slurry, and if necessary, cationic polyamide is added. Polyamine epichlorohydrin resin, cationized resin, acrylamide based melamine resin, polyimide resin, CMC, '4+ strength strengthening agent,
Or ordinary papermaking chemicals such as sulfuric acid, sodium aluminate, anionic, cationic, nonionic polymer flocculants, stringy polymers such as polyethylene oxide, polymer resin emulsions, rubber latex. After adding and mixing an appropriate selection from among the following.

Paper is made using a normal paper machine. (The base paper obtained here has no size and has an air permeability of 80 Pl) or less. After this, a polymer resin that imparts low dust generation, size effects, two paper layer peel strength, etc. is soaked or neat. The impregnation or coating may be carried out on the paper machine by on-machine size pressing or coating;
It may be impregnated or coated off-machine.

The polymer resins used for impregnation or coating in the present invention include polyacrylic acid ester, polyvinyl acetate, polyvinyl chloride, and polyethylene.

Copolymer resin emulsion such as polystyrene.

Or natural rubber type, SB, R type, SB type, MBR type,
One or more types selected from NBR latex, etc., with a minimum film forming temperature (MFT) of 10°C or lower, preferably 5°C or lower, or two or more types. If so, MFT is below 10℃.

The effects of the present invention can be achieved by adjusting the mixture so that the temperature is desirably 5°C or less. (f) (Also, cationic neutral sizing agent, water-soluble melamine resin, PVA, water-soluble acrylic resin, if necessary.

Methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, fluorine-based oil resistance agent/mold release agent.

Silicone water repellent agent - type 11 agent, wax emulsion, etc. may be mixed and used. These polymeric resins have a 10 to 50% heavy duty ratio for newborns, and 15 to 5'fft (・
It must be said %. If the content is less than 10% by weight, the effect of suppressing dust generation will be small.
A large amount of coarse powder falls off, making it unsuitable for the purpose of use of the present invention. On the other hand, when the content exceeds 50% by weight, the polymer resin cannot fully enter the paper layer and a thick resin film is formed on the surface of the paper, which not only obscures the tetraelectric property but also impregnates the paper layer. ,
Otherwise, blocking occurs in the rolled state during coating, making it unsuitable for the purpose of use. In addition, the electrical resistance value of the conductive paper obtained in this way is such that the volume resistance value is 108 Ω・α or less (preferably 10 7 Ω・m or less) when the purpose is antistatic property, and the electromagnetic shielding property is 10 Ω・α or less (preferably 10 7 Ω・m Objective 9
For the 7th case, it is desirable that the resistance is 102 Ω·m or less (preferably 101 Ω·m L or less). However, depending on the intended use of the box assembly, the surface resistance value may be more important than the volume resistance value.
, we can obtain a concave circle that allows optical matching.

In this way, the low-particle-producing conductive boat obtained in 1.7 is subjected to secondary processing such as coating, embossing, lamination, and molding as necessary to create electromagnetic shielding materials, electromagnetic materials, etc. It can be used satisfactorily even in environments where dust generation is extremely feared, such as inside a clean room, and its applications can be expanded to a wide range of areas. It is useful.

The present invention will now be specifically explained with reference to examples, but these examples are not intended to be exhaustive.

Example 1 Unbleached kraft pulp was weighed by Shopper Ligraf (
1% by weight (based on the pulp) of cationic polyamide resin as a wet paper strength enhancer, and 2% by weight (based on the pulp) of sulfuric acid is added to make the pH q, and then aluminium The paper was made using a Ryonagaami paper adjusted to a pitch of 7.5 using acid soda and an ft machine. The basic weight of this idea is 6b.

The size degree was 0, and the casting degree was 10 seconds. Next, the mixture was mixed with a polyacrylic acid ester copolymer in an off-machine, and after adjusting the total solid content concentration to 25%, impregnation was performed. The MF'T of this mixture was 5°C or less. As shown in Table 1, the results of measuring the performance of the paper obtained were highly practical and could be used as a carrier tape for precision electronic components such as IC chips.

Example 2 Bleached kraft pulp (shopper rigler frill),
15% titanium oxide (based on pulp) and cationic polyamide resin as a wet paper strength enhancer were mixed at 2.0% (based on pulp), and the pT was adjusted to 7.0 in the same manner as in Example 1. After that, paper was made using a Fourdrinier paper machine.The basis weight of this base paper was 801/rr?, the sizing degree was 0 seconds, and the air permeability was 5 seconds. After adjusting the paper to a polymer resin, it was impregnated.As shown in Table 1, the performance of the resulting paper was highly practical and could be used as an antistatic wall covering material. Examples 8 to 5 After beating bleached kraft pulp to a degree of freeness of 28'SR, the same carbon black and carbon fiber as in Examples 1 and 2 were used, and the amounts of each added were changed to 111I. Amount 65
9/n? , a base #'F of size 0 seconds was made.

Furthermore, the type of polymer resin to be impregnated and the minimum film forming temperature,
Furthermore, samples were prepared under the conditions shown in Table 1 with various content rates. As shown in Table 1, the results of the n-th measurements were sufficient for practical use. In addition, as a comparative example, it is possible to obtain a conductive paper f with low dust generation by the paper forming and polymer resin impregnation processing according to the present invention, as shown in the same example and comparison example as in Example 1. was completed.

Patent applicant: Kojin Co., Ltd.

Claims (1)

[Claims]] Conductive inorganic powder 5 to cellulose valve slurry
After making paper by mixing 50% by weight + J% and/or 0.5 to 30% by weight of conductive fibers. Low dust generation type 4, #, characterized by being impregnated or coated with a polymer resin content of 10 to 50%. 2. The low-dusting conductive paper according to claim 1, wherein the polymer resin has a minimum film-forming temperature adjusted to 10° C. or lower.