JPS6147898A - 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 (Industrial Application Field) The present invention relates to conductive paper, and more specifically to packaging materials for electronic components that prevent static electricity problems, electronic devices incorporating the components, and facsimiles, The present invention relates to conductive paper that can be applied to the conductive layer of electrostatic recording paper used in printers and the like.

Electrostatic recording paper has a conductive layer and a dielectric layer as essential components, and further includes a base layer and a protective layer as necessary. The present invention applies an electrostatic layer to the recording layer (dielectric layer),
In addition to electrostatic recording paper in a narrow sense to which a developer is transferred, the a-angle can also be applied to heat-sensitized electrostatic recording paper using a heat-sensitive recording method, discharge recording paper using a discharge printing method, and the like.

(Conventional technology) Conductive paper for removing static electricity is often used today.

Usually has a volume resistivity of 10' to 1ΩcI11,
Also? t'l' electrographic paper usually requires a conductive layer with a surface resistivity of 1σ to ICfΩcm. Furthermore, heat-sensitized electrostatic recording paper (electrothermal recording paper) uses a low-resistance conductive layer.
Electrostatic recording paper that develops an electrostatic latent image after it is formed requires a high-resistance conductive layer. For this reason, in the former, for example, conductive carbon powder, metal powder, or metal fibers are used as low-resistance conductive substances, and in the latter, conductive resins, surfactants, etc. are used as high-resistance conductive substances. It's here.

However, since carbon powder, metal powder, etc. are colored conductive substances, it is extremely difficult to adjust the color tone of the surface of a recording paper containing them to white or any other desired color tone.

Therefore, the conductive layer placed on the top surface of the conductive layer must be made of a material with excellent hiding power, and although various improvements have been made to meet this requirement, there is still no technology that can satisfy this requirement. On the other hand, with high-resistance conductive layers using conductive polymers, the problem of color tone has already been solved, but the stability of conductivity against humidity and water resistance during use remain unresolved. Problems remain← In addition to the above, metal powders traditionally added for the purpose of imparting electrical conductivity have a poor reinforcing effect even when mixed with pulp slurry, and furthermore, metal powders that have been added for the purpose of imparting conductivity have a poor reinforcing effect, and furthermore, It is also difficult to disperse it uniformly. Therefore, the product obtained here is an excellent conductive paper with a remarkable difference between the front and back sides. In this regard, conductive materials made of long fibers such as metal fibers have excellent paper-mixability and reinforcing properties, and have good conductivity, but microscopically, there are irregularities in conductivity corresponding to the fiber length, so It has been pointed out that the disadvantage is that the resolution deteriorates over the life of the paper, making it difficult to obtain clear images.

(Problems to be Solved by the Invention) The problems to be solved by the present invention are to arbitrarily adjust the conductivity of various conductive papers by utilizing conductive alkali metal titanate as a new conductive material. In addition to creating a means to do so, it also facilitates color adjustment of recording paper, and furthermore, by utilizing the reinforcing effect of the conductive alkali metal titanate,
The purpose of the present invention is to provide conductive paper with excellent strength and moisture resistance.

(Means for Solving the Problems) In order to solve one or more problems, the present invention adopts a configuration in which a conductive alkali metal titanate is contained as a conductive component in part or all of the paper. Hereinafter, an outline of the alkali metal titanate, which is a main component of the present invention, will be explained.

(13 In the present invention, "conductive alkali metal titanate"
means 10'ΩcI11-10'm when measured by the method for measuring the electrical conductivity of conductive alkali metal titanate described below.
A conductivity in the range of ΩC111 is preferable; a conductivity exceeding tCPΩcat is impractical as the surface resistivity of the resulting conductive paper is less than 1CPΩ4;
Although it is convenient to obtain conductive paper with low resistance if it is less than ΩC1, it is necessary to obtain conductive paper with a surface resistivity of IQΩ or higher, which is generally used as electrostatic recording paper. The proportion of alkali metal titanate used had to be extremely reduced, and as a result, as with conventional highly conductive fillers, the blending ratio changed slightly due to fluctuations in manufacturing conditions during production. , it becomes difficult to reproduce a constant design conductivity,
This may make quality design and production management difficult.

However, even if the conductivity is less than 1OΩam or more than 1φΩam, the conductivity of the titanium titanate of the present invention can be used as long as the conductivity is as good as can be expected with various conventional conductive fillers or conductive substances. For electrostatic recording paper that does not require the various features resulting from the use of acid-alkali metals, it is possible to use conductive alkali metal titanates having any conductivity without being restricted to the above conductivity range. It is of a nature that should only be evaluated.

(2) Representative examples of conductive alkali metal titanates suitable for carrying out the present invention are detailed below. That is.

(A) General formula, M20 ++ n T i 02-, e mH20
(In the formula, o < n < 3, 0 < b < 4, o < x < 2
.

,

CB) Conductive alkali metal titanate in which a different metal is introduced into alkali metal titanate.

(C) A conductive alkali metal titanate obtained by firing or reducing and firing a compound consisting of an alkali metal titanate and a different element.

(D) Alkali metal titanate and/or - as mentioned above (A
) to (C) The conductivity obtained by chemically coating the surface of the conductive alkali metal titanate with a conductive metal and/or metal compound or forming a eutectic with these metals and/or metal compounds. alkali metal titanate.

etc. Incidentally, the present inventor has already completed various inventions regarding methods for producing conductive alkali metal titanates that impart effective electrical conductivity to the alkali metal titanates without degrading their physical properties, and these inventions are currently in progress. Application is pending.

What are some of the most representative inventions?

Patent application No. 55-179902, No. 55-L L 9481
, 57-(4)46, 57-16742, 57-
114890. 57-21 green onions, etc. However, the conductive titanium alkali metal of the present invention is of course not limited to those described in the original specification of the invention.

The conductive alkali metal titanate in the present invention includes not only the above-mentioned conductive alkali gold titanate E (A) to (D) alone or in a mixture, but also all reinforcing or non-reinforcing conductive alkali metal titanates. However, from a practical point of view, fine fibers are preferable, and the fiber diameter is usually 0.14.
~100 μs and an aspect ratio of about lN1000 are preferable from the viewpoint of imparting surface smoothness to the product as well as reinforcing effect.

There is no particular limitation on the conductivity of the conductive paper according to the present invention, and it is sufficient to select one that suits the usage conditions, but it is normal to select one that has a specific volume resistivity of 1O° to ICf'Ωc11. Practical, therefore, the electrical conductivity of the conductive alkali metal titanate, which is the main material of the paper of the present invention, is also 1O-1.
The conductive alkali metal titanates having a conductivity of 10" to 1 Of Ω C1l+, which are preferably those in the range of 0"0 cm, are particularly those described in the above-mentioned conductive alkali metal titanates (A) to (C). It exhibits a pale blue to deep purple color. Therefore, when this is used for conductive paper, the color becomes light blue to light purple, and the color can be easily adjusted using commonly used colorants.

Incidentally, highly conductive alkali metal titanates with a conductivity of lO-'' to 10 Ωcm generally exhibit black, blackish-purple, or gold colors, and are convenient for making low-resistance conductive paper. However, as it is, the coloration is significant, so in order to utilize it for electrostatic recording, it is necessary to improve the hiding power of the dielectric layer, as in the prior art.

Conductive paper (I), which is the first aspect of the present invention, can be obtained by dispersing conductive alkali metal titanate in a pulp slurry and carrying out papermaking, drying, etc. in a conventional manner. The pulps used at this time include ordinary vegetable pulp obtained from wood, steel pulp derived from asbestos, synthetic lA11m pulp such as vinylon, etc.
Each can be used alone or in combination.

As mentioned above, in conventional conductive paper, the conductivity was mainly adjusted by the amount of conductive material mixed in (mff1), but in the present invention, conductive alkali titanate having the desired conductivity was used. Since the metal can be freely selected, the amount of the conductive alkali metal titanate to be mixed may be determined by taking into consideration the paper processability when making conductive paper, the strength of the product paper, etc. However, in general, the mixing ratio of conductive alkali metal titanate is about 1 to 40% by weight based on the pulp. In addition, during papermaking, additives commonly added in the production of ordinary paper or conductive paper, such as paper strength enhancers, sizing agents, fillers, etc.
Dyes, pigments, wettability improvers, etc. can be added as necessary. Furthermore, if necessary, conductive materials such as carbon black, metal powder, metal oxide powder, metal fiber, carbon fiber, etc., which are commonly used in addition to the conductive alkali metal titanate, may be used. Zero or more additives that may be used in combination can further improve the conductivity homogeneity and surface smoothness of the product compared to the case where conductive alkali metal titanate 84k is used alone. In addition, reinforcing binders commonly used in paper making, such as solutions of water-soluble polymeric substances or water-based resin emulsions, or auxiliary agents such as conductive binders or conductive surfactants may also be used.

A second aspect of the present invention relates to a conductive paper (II) having a conductive coating layer containing a conductive alkali metal titanate on a base paper. The "base paper" referred to here refers to a fabric made of organic, organic and/or inorganic fibers, and an organic film attached to both or one side of the fabric, or the film is attached between two sheets of the fabric. It means a fabric with a laminated structure sandwiched together. A conductive coating layer is provided on one or both sides of these fabrics. In some cases, one or more of the above-mentioned conductive coating layers may be bonded together.
A superimposed multi-layer A-layer structure may also be employed. In the above, the conductive coating layer is obtained by forming a film of a conductive alkali metal titanate homogeneously dispersed in a dispersion medium containing a binder, and the coating on the base paper is the conductive alkali metal titanate. The following methods are used: (1) applying a homogeneous dispersion of an alkali metal onto a base paper to form a film; and (2) attaching a conductive film that has been separately formed into a film using a commonly used method to the base paper. However, the method of coating and forming a film is preferable due to the ease of the process. However, in the case of a complex laminated structure with multiple conductive coating layers, the method of pasting a pre-formed film is preferable. Sometimes it's easy. Of course, the conductive paper and electrostatic recording paper for removing static electricity that are commonly used in practical use are:
The coating method is sufficient.

In the above, as the binder, either a conductive binder or an electrically insulating binder can be used, but in reality, taking into account the characteristics of various binders, the hygroscopicity should be reduced after film formation. It is preferable to select, depending on the intended use, a material that has good humidity stability, low thermal and photodeterioration, or good resistance to various chemical substances and water resistance.

The present invention stabilizes the content of the conductive alkali metal titanate in the dispersion medium or binder by arbitrarily selecting the conductivity of the conductive alkali metal titanate depending on the desired conductivity of the conductive paper. A major feature is that it allows Therefore, the binder of the present invention should be arbitrarily selected depending on the application (purpose of use), but usually, the volume concentration of the conductive alkali metal titanate to the binder is determined by the critical volume concentration (cpvc). This critical volume concentration, which is preferably around or below, varies depending on the type of binder, but is usually 100 fflffi parts (hereinafter referred to as parts) of the binder.
The total conductive alkali titanate concentration is 1 to 200 parts, preferably 10 to Zoo parts, below the cpvc for commonly used binders. If the amount of conductive alkali metal titanate is too large compared to CPVC, the bonding strength will be insufficient,
It becomes easily desorbed from the base paper and is easily influenced by external factors such as humidity. On the other hand, if there are too few stars of conductive alkali metal titanate, homogeneous dispersion of conductive alkali metal titanate will need to be taken into consideration during film formation, as in the conventional technology, and quality control and production control will need to be precise. will be done.

In the present invention, for dispersing the conductive alkali metal titanate into the binder, commonly used dispersion means can be used as is. It is preferable to use an aqueous emulsion, but it may also be dissolved or dispersed in an organic solvent.
In particular, for those that are bonded after forming into a sheet, a heat-melting binder can also be used.

Next, regarding the film forming method, when forming a film on the base paper,
Any conventional coating method such as brush coating, roller coating, roll coater method, spray method, or jet spray method can be applied. Further, in the case of the sheet pasting method, any means such as adhesion with an adhesive, adhesion with an adhesive, heat welding, thermal transfer method, etc. can be selected.

In the present invention, in the coating layer or in the dispersion before forming the coating layer, various commonly used additives such as dispersants, color rejuvenators, coating improvers, film forming aids, reinforcing agents, In addition to the non-reinforcing filler, any film-forming success agent may be added, and if necessary, other commonly used conductive fillers may be used in combination.

Conductive paper (1 and II') of the first or second aspect of the present invention
) can be used as is or in combination with other commonly used sub-materials to produce wrapping paper, paperboard, storage boxes, etc. for static electricity removal.
Used as transportation tools and packaging materials. Its conductivity varies depending on the purpose of use, but it is usually 10' to 1o'2Ω.
It is preferable that the conductive alkali metal titanate has a volume resistivity of 10"3 to 1".
0''ΩCl11 is preferred.

A third aspect of the present invention relates to electrostatic recording paper CI [[] using the conductive paper of the present invention.

Generally, electrostatic recording paper is roughly divided into electrostatic printing, discharge printing, and current-heat-sensitive printing methods based on the difference in the single-image phenomenon method, but all of these require a conductive layer and a dielectric layer. do. It is necessary for this conductive layer to maintain stable conductivity as designed in the range of surface resistivity from lO' to 1pi04. Since the ratio can be arbitrarily selected depending on the set conductivity of the conductive paper, the conductivity of the conductive paper can be adjusted without changing the physical properties.

The electrostatic recording paper (m) according to this embodiment is manufactured by using the conductive paper (I or II) of the first embodiment or the second embodiment as a conductive layer and combining it with any commonly used dielectric layer. Ru. That is, the above electrostatic recording paper (m) is one in which a dielectric layer is provided directly on the surface of the conductive paper (No. At this time, the difference in conductivity between the conductive layer and the dielectric layer is difficult to limit as it varies depending on the application and implementation, but usually a difference in volume resistivity of 10S to 10"0cm or more is required. be.

As the dielectric layer in the recording paper of the present invention, any commonly used dielectric resin can be arbitrarily selected, and representative examples include alkyd resin, epoxy resin, polyethylene resin, polyester resin, vinyl acetate resin, vinyl chloride resin, Vinylidene chloride resin, styrene resin, acrylic resin,
Examples include methacrylic resin, polyvinyl butyl resin, polyvinyl ether resin, urethane resin, silicone resin, cellulose resin, petroleum resin, toluene resin, phenol resin, and amine resin. These conductive resins may be applied alone, as a mixture of two or more, or in the form of a copolymer.

The above resins are usually printed or applied in a solution or dispersed state onto the surface of conductive paper to form a dielectric recording layer. This dielectric layer may contain cellulose fine powder, starch, synthetic resin ry5 fine powder, natural clay, fired clay, kaolin, quartz sand, calcium carbonate, zinc oxide, titanium dioxide, magnesium oxide, barium sulfate, Organic materials such as aluminum silicate, alumina, colloidal silica, aluminum hydroxide, etc., or mixtures of two or more organic materials, metal salts of organic fats for dielectric constant adjustment, dielectric aids such as surfactants, dispersants, etc. Various commonly used film-forming aids such as anti-oxidants, anti-aging agents, and concavity agents may be added.

The fourth aspect of the present invention, heat-sensitized thermal recording paper (■),
It consists of a conductive layer made of the conductive paper (C or II) of the present invention, a thermosensitive coloring layer and/or a conductive layer, a thermosensitive coloring layer and a dielectric layer, in which the conductive layer, thermosensitive coloring layer and dielectric layer The combinations are according to the commonly used formats, for example, a conductive layer with a heat-sensitive coloring layer a layer, a laminate of three layers of a conductive layer, a heat-sensitive coloring layer, and a dielectric layer, a conductive layer, a thermosensitive coloring layer, and a dielectric layer. A structure in which a conductive layer, a dielectric layer, and a heat-sensitive coloring layer are stacked in this order can be arbitrarily adopted.

The conductive layer and dielectric layer of the present invention can be arbitrarily selected from those shown in Parts 1 to 4, and the heat-sensitive coloring layer is made of bisphenol. A: This layer is composed of an electron-accepting coloring agent such as maleic anhydride, a binder such as methylcellulose or hydroxymethylcellulose, and other additives, auxiliaries, and a conductive agent.

The structure of the present invention has been described in detail above.The conductive paper of the present invention is intended to provide a conductive layer that can be applied to conductive paper for removing static electricity and electrostatic recording paper.

In this specification, the conductivity of the conductive alkali metal titanate and the conductive paper was measured by the method shown below unless otherwise specified.

1) After filling 1 g of conductive alkali metal titanate into the goo using a single-component molding machine for testing, press and mold at 200 kg/d onto both sides of the test tablet while degassing with a vacuum pump. After vacuum-depositing a Pt-Pd alloy as an electrode and leaving it in a constant temperature room adjusted to 60% humidity and 20°C for 2 hours,
Using a digital cortimeter TR-8841' (manufactured by Takeda Riken Co., Ltd.), the resistance value (R2O) between both electrodes was measured, and the apparent conductivity of the conductive alkali metal titanate was determined using the following formula.

Apparent conductivity of alkali metal titanate (right 1 ・0c
m) = 2.26 R1 (Ωca+) (2) The volume specific resistivity and surface resistivity of the conductive paper were measured using a digital cortimeter TR-6841 (Kamiyama) according to JISK6911 for the conductive paper prepared in each example. Volume resistance (R2O) and surface resistance (R3O) were measured using the attached tool TR-42 and calculated using the following formula.

Volume specific resistivity Σ2 (Ωcs+) = 19.63 R
2 (00 rin) surface resistivity and 3 (o”i = 18.8
4R3(o) Hereinafter, the modes and effects of carrying out the invention will be described using examples, but the examples are of course for illustrative purposes and are not intended to limit the spirit of the invention.

[Example 1] Wood pulp (NBKP) was beaten in a normal manner,
This was mixed with 35% of conductive alkali metal titanate (manufactured by the applicant company: BK-80, conductivity 2. I x 108Ω).
C111) and has a thickness of 100 l, a slight bluish tinge, and a volume specific resistivity of 9.3 x 10? A conductive paper of ΩCm was obtained.

[Examples 2 to 5] The same procedure as in Example 1 was performed except that the type of tetraelectric alkali metal titanate was changed, and the results shown in Table 1 below were obtained.

Table 1 C Example 6J A dispersion consisting of 30 parts of the conductive alkali titanate of Example 1, acrylic resin (Mitsui Toatsu Chemical Co., Ltd. Almatex 0XL129, concentration 50%), and 10 parts of toluene was poured onto 60 liters of high-quality paper. By coating the surface of the paper and drying it, a conductive paper coated with a pale blue conductive layer and having a surface resistivity of 1.73XloIQA was obtained.

[Examples 7 to 10] The same method as in Example 6 was carried out except that the type of conductive alkali metal titanate was changed, and the results shown in Table 1-2 were obtained.

(Margin below) Table 2 Incidentally, the conductive properties of the conductive papers obtained in Examples 7 and 8 above are suitable for electrostatic recording paper, and the conductivity properties of the conductive papers obtained in Examples 7 and 8 are suitable for electrostatic recording paper.
．． No. 10 is suitable as a static electricity removal material.

[Example 11] 30 parts of precipitated barium sulfate and styrene:butadiene = 2
A homogeneous mixture consisting of 70 parts of an emulsion consisting of a 0:80 copolymer was applied onto the surface of the conductive paper prepared in Example 1 with a bar coater to a dry basis weight of 10 g/m, and then dried. A white electrostatic recording paper was obtained.

The electrostatic recording material was charged by +100 OV corona discharge, and the transfer potential was measured to be 180 V. As a result of actual imaging experiments, clear records were obtained.

[Example 12] A white electrostatic recording paper was obtained in the same manner as in Example 11 except that the emulsion was changed to a styrene:methyl acrylate 50=50 copolymer. When the transfer potential was measured in the same manner as in Example 11, it was +190 V, and a clear recording material was obtained even in one image forming experiment.

[Example 13] The same procedure as in Example 12 was carried out except that the conductive paper of Example 7 was used instead, and an electrostatic recording paper was obtained which provided a transfer potential of +170 V and a clear recording medium even in an image forming experiment. .

[Example 14] A homogeneous dispersion consisting of 1.5 parts of crystal violet lactone, 1.5 parts of polyvinyl alcohol, and 0.1 part of p-hydroxyphenylacetate was applied to the surface of the conductive paper of Example 1 at a dry basis weight of 1 g/ The coating was coated to give a coating thickness of m'' and dried to obtain a white heat-sensitized electrostatic recording paper.

When this recording paper was applied to a facsimile machine for recording discharge breakdown, recording speed: 1 m/sec, voltage = 100 V (AC)
Under these conditions, a clear hard copy with a blue color was obtained.

(Effects of the Invention) The present invention can significantly contribute to the development of various fields that utilize conductive paper by exhibiting the following industrial effects.

(1) The conductive paper for removing static electricity and the conductive paper for electrostatic recording layer according to the present invention have high industrial utility value.

[2] The conductive paper of the present invention is extremely easy to manufacture,
Quality design and production management should be easy.

(311) The conductive paper material of the present invention has stable conductivity.

(4) The conductive paper of the present invention has a light color tone and is excellent in post-processability.

15) Since the conductivity of the conductive alkali metal titanate, which is the main material of the conductive paper of the present invention, can be adjusted as desired, conductive paper can be freely manufactured according to the purpose.

161 When the conductive paper or the coating layer forming the conductive layer contains 30 to 50% by weight of the conductive alkali metal titanate, the volume specific resistivity of the conductive paper of the present invention increases. Since it roughly matches the conductivity of
Quality design is easy: Seven.

Claims (5)

[Claims] (1) A conductive paper characterized by containing conductive alkali metal titanate as a conductive component. (2) The conductive paper according to claim 1, wherein the conductive alkali metal titanate is mixed with pulp fiber. (3) Claim 1, characterized in that it has a conductive coating layer containing conductive alkali metal titanate on the base paper.
Conductive paper as described in section. (4) In an electrostatic recording paper comprising a conductive layer and a dielectric layer,
The electrostatic recording paper according to any one of claims 1 to 3, wherein the conductive layer contains an alkali metal titanate. (5) In the heat-sensitized electrostatic recording paper comprising a conductive layer and a thermosensitive coloring layer, the heat-sensitized electrostatic recording paper according to any one of claims 1 to 3, wherein the conductive layer contains an alkali metal titanate. Electrostatic recording paper.