GB2169296A - Electrically conductive compositions - Google Patents

Abstract

A composition comprising an electrically conductive alkali metal titanate and a binder is useful for preparing an electrically conductive shaped product such as a sheet or film.

Description

SPECIFICATION Composition Containing Electrically Conductive Alkali Metal Titanate and Shaped Products thereof The present invention relates to a composition containing an electrically conductive alkali metal titanate (hereinafter referred to as "EAT") and shaped products thereof.

To meet diversified needs for electrically conductive materials in recent years, it has been desired to develop conductive compositions which are outstanding in heat resistance, chemical resistance, process ability, etc. and shaped products thereof. Various conductive compositions comprising a filler and a binder have been developed. While binders heretofore made available have high resistance to heat or chemicals, conventional non-reinforcing materials such as carbon powder, metal or metallic oxide powders, and powders of cuprous iodide and like copper salts are used as conductive fillers. When the composition contains an increased amount of conductive filler so as to have enhanced conductivity, the composition exhibits seriously reduced strength.Thus, the adjustment of mechanical properties and conductivity of the composition requires great skill in selecting its components, production process control, etc. These conventional conductive powders are generally unstable; some become less conductive when subjected to a chemical change such as oxidation, or some vary in conductivity when adsorbing water or the like. In fact, the known powders have difficulty in retaining stable conductivity over a prolonged period of time. Accordingly it has been desired in the art to develop conductive fillers which are excellent in compatability with binders, reinforcing properties and stability.Although attempts have been made to use carbon fibers or metal fibers as substitutes to give improved reinforcing properties, it is difficult to obtain such fibers of uniform length, while these materials have problems in respect of surface smoothness, shapability, productivity and workability of shaped articles obtained. Conductive fillers of noble metal such as gold or platinum are stable in conductivity but are expensive. Thus, the conventional fillers do not fulfill all the requirements.

An object of the present invention is to provide an electrically conductive composition containing a conductive filler which is outstanding in stability, reinforcing properties and compatibility with binders.

Another object of the invention is to provide a conductive composition for giving shaped articles which are excellent in surface smoothness, shapability, productivity and workability after shaping.

These and other objects of the invention will become apparent from the following description.

The present invention provides a composition comprising an EAT and a binder, and a shaped product thereof.

The composition of the present invention are usable for materials which must be electrically conductive, such as conductive materials, resistance materials, antistatic materials, electrostatic charge protecting materials, electromagnetic wave shielding materials, etc. Especially when made into shaped products, the present composition provides conductive materials which are outstanding in heat resistance, chemical resistance and surface smoothness.

The EAT's of the present invention includes: (1) EAT's (I) represented by the formula M2O-aTiOxZbH20 wherein M is an alkali metal such as Li, Na or K, 0 < a'8, 0b4 and 0 < x < 2, a, b and x being each a real number. The EAT (I) is generally termed a reduced alkali metal titanate or bronze alkali metal titanate.

(2) EAT's (II) prepared by coating an alkali metal titanate represented by the formula M2OaTiOybH2O wherein M, a and b are as defined above, and 0 < y2 with at least one of conductive metals and conductive metal compounds such as conductive metallic oxides and halides.

(3) EAT's (III) prepared in a reducing atmosphere or prepared in an oxidizing atmosphere, followed by a reducing or doping treatment when required, when an alkali metal titanate represented by the formula M2OaTiOybH2O wherein M, a, b and y are as defined above is produced under such condition that a conductive metal and/or a conductive metal compound (e.g. conductive metal oxide or halide) will form a eutectic with the titanate, or crystallize or separate out on the surface of the titanate, i.e. when the titanate of the formula is produced in the presence of the materials therefor, and one of conductive metals and conductive metal compounds (e.g. oxides, hydroxides, halides, carbonates, nitrates and sulfates of such metals) or a mixture of at least two thereof.The EAT's of the invention further include mixtures of at least two of these EAT's.

The EAT's of the present invention are distinguished from an alkali metal titanate (IV) (hereinafter referred to as "AT (IV)") represented by the formula M2O-aTiO2 bH20 wherein a and b are as defined above.

Generally AT (lV) is obtained as a fibrous single crystal, is useful as a heat-resistant reinforcing filler but is an electrical insulator. When used singly, AT (IV) is unable to provide a conductive composition.

Accordingly a conductive composition having the reinforcing and heat-resistant properties of AT (IV) is obtained by using an EAT of the invention, or a conductive filler, conductive resin or the like which is generally used, in combination with AT (lV). Conductivity can not be given to the composition without making use of this property of a material other than AT (IV).

As regards EAT's of the present invention, we have already developed or invented a process for producing EAT (I) from AT (IV), a process for producing EAT (II) from AT (IV), and further a process for producing AT (IV) in connection with a process for producing EAT (III). We have also invented a process for imparting conductivity to electrically insulating AT (IV) by chemically coating the titanate with a conductive metal and/or conductive metal compound or forming a eutectic of such substances thereon, and further a process for preparing EAT by separating out or crystallizing such substance(s) on AT (IV). We have further found it technically possible to economically coat AT (IV) with a conductive material by a chemical or physical treatment such as CVD (Chemical Vapor Deposition) or PVD (Physical Vapor Deposition). Thus we have developed or invented various processes for producing EAT's which effectively retain the physical properties of alkali metal titanates, and filed patent applications for these processes.

Typical of the inventions on EAT's we have accomplished are those disclosed in Japanese Patent Applications No. 1981-119481, 1982-14146, -16742, -114890, -133943 and -21230, and Published Unexamined Japanese Patent Application No. 1983-20722. However, EAT's of the present invention are not limited to those disclosed in these publications.

The EAT's to be used in the present invention are conductive materials which are excellent in reinforcing properties and resistance to chemical deterioration. They are produced chiefly by the following processes.

(i) EAT (I) can be produced by heat-treating AT (IV) at a temperature of at least 300"C, preferably at least 5002C, in a reducing atmosphere containing a reducing gas such as H2 or CO, or in a non-oxidizing atmosphere in the presence of a reducing agent such as carbon or the like. Alternatively EAT (I) can be produced directly from a system for preparing AT (IV) by maintaining the system in a reducing atmosphere, or in a non-oxidizing atmosphere in the presence of a reducing agent. When the metal M in the formula M2O-aROxw bH2O (wherein M, a, b and x are as defined above) is potassium, EAT (I) is a reduced potassium titanate which, with the variation of x, undergoes the color change of: whitish purple, purple, black, blackish purple, gold and silver white in the order mentioned.In view of conductivity, the EAT (I) useful for the present invention is preferably one which has been reduced to such an extent that x1.99, more preferably x < 1.95, with a pale purple to black color.

(ii) EAT (II) is produced by coating EAT (I) and/or AT (IV) with a conductive compound. Useful coating methods are electroless plating, wet neutralization, CVD, PVD, etc. which are generally used at present for giving conductivity to surfaces, while we have accomplished a technique for producing EAT (11) by depositing a conductive compound of tin, indium, antimony, copper, nickel or the like on the surface of AT (IV) by wet reaction. We have further accomplished a technique for producing EAT (II) comprising an alkali metal titanate represented by the formula M2O.aTiOy.bH2O (wherein M, a, b and y are as defined above) and coated with at least one metal selected from the group consisting of Ni, Cu, Pt, Ag, Au, Cr and Pd.We have found that of the compounds represented by the above formula, reduced titanate compounds represented by the formula M2OaTiOxbH2O (wherein M, a, b and x are as defined above) are conductive by themselves and can be coated with a conductive metal compound easily by electroless plating to give improved conductivity.

EAT (Il) of the present invention has higher conductivity than EAT (I) and is therefore advantageous to use. Also advantageous is a white EAT (II) produced by coating insulating AT (IV) with a transparent conductive metal compound such as tin oxide, antimoney oxide, indium, copper iodide or the like.

(iii) EAT (III) is produced when an alkali metal titanate of the formula M2O-aTiOy.bH2O (wherein M, a, b and y are as defined above) is prepared from a titanium source such as titanium oxide or titanium hydroxide and an alkali source such as alkali carbonate or halide, by heating these sources at 500 to 1200"C or with microwaves in the presence of an oxide, halide, carbonate, sulfate, nitrate or the like of tin, copper, silver or the like. Typical of such EAT (III) is a white EAT which is formed by the reaction of titanium oxide, potassium carbonate and tin chloride in a molten state and in which tin oxide is separated out on the surface of potassium titanate whiskers.

While typical examples of EAT's of the present invention have been described, the EAT's of the present invention further include mixtures of at least two of EAT's (I) to (III), and other reinforcing or non-reinforcing EAT's. Preferable from the viewpoint of actual use are EAT's in the form of fine fibers which are 0.1 to 100 Fm in diameter and about 1 to about 1000 in aspect ratio, whereby a reinforcing effect and surface smoothness can be given to the shaped product obtained. However, the form and conductivity of EAT is not limited particularly but should be determined in accordance with the contemplated use.

According to the present invention, various binders are usable.

Examples of suitable binders are setting resins having at least one active reactant group selected from the group consisting of hydroxyl, alkoxyl, carboxyl, amino, cyano, epoxy, vinyl and acetyl. Typical examples of setting resins are amino resin, phenolic resin, alkyd resin, epoxy resin, urethane resin, polyamide resin, polyester resin, vinyl resin, polyimide resin, polymercapto resin, silicone resin, fluorocarbon resin, boron resin, organotitanium resin, inorganic settable substances such as silicate, phosphate and borate, mixtures of at least two of such materials, and prepolymers thereof, these materials being curable into insoluble and nonmeltable binders with heat, light, electron rays, catalysts or the like.

Although suitable curable binders are generally organic setting resins, inorganic curable binders are also usable insofar as they have processability and binding ability.

In view of ease of processability, curable binders are generally given in the form of prepolymers before being cured into insoluble nonmeltable binders. Usually, therefore, the binder is provided or used in the form of a powder, liquid, solution containing a solvent, dispersion or emulsion containing a dispersant or emulsifier or, in a special case, gas. Binders of those forms include those which are not stable but immediately react or cure in the natural atmosphere at room temperature, those which cure when made into a mixture of at least two kinds of binders, and those which are cured by the addition of a catalyst, without being exposed to external energy such as heat or light.These reactive binders must be preserved in a reaction inhibiting environment such as an inert gas atmosphere or cold dark place, require addition of a reaction inhibitor, or need to be preserved as individually separated from one another or as separated from the catalyst. Even such binders are usable provided that they bind and cure EAT of the invention.

Other examples of suitable binders for the present invention are soft binders for forming a soft coating layer and hard binders for forming a hard coating layer.

Examples of preferred soft binders are 1) amorphous or low-melting hydrocarbon compounds or derivatives thereof such as vaseline, lanolin, petralatum and bitumenous compounds, 2) oils and fats such as glyncerin esters of fatty acids, 3) polyalkylene oxides in the form of homopolymers or copolymers of alkylene oxides such as ethylene oxide and propylene oxide, 4) alkylpolyalkylene oxides which are adducts of fatty acid glycerin oxides and alkylene oxides, and derivatives thereof, and 5) compounds which are liquid or plastic at room temperature, such as liquid polyethylene, liquid polypropylene, liquid acrylic resin, etc. These binders are used singly, or at least two of them are used in admixture.

Binders which are generally used for coating compositions, inks, adhesives, sealants, etc. are usable as such to serve as the latter hard binders. Examples of preferred hard binders are higher fatty acid derivatives, polyolefin compounds, rubbers, acrylic resin, vinyl ether resin, vinyl formal resin, vinyl acetal resin, cellulose resin, polyacetal, polysulfone, polyimidazole, polyoxazoline, polyoxazolam, etc., mixtures or copolymers of at least two of these compounds, etc.

EAT and the binder can be mixed together by any of common means, such as a dispersing device, mixer or kneader, in a desired atmosphere, such as a room-temperature atmosphere, heated atmosphere, cooled atmosphere, vacuum or atmosphere replaced by a specific gas. According to the invention, the binder is usable in the form of a solution, or an emulsion, colloid or dispersion with use of a solvent or dispersant. To prepare and/or use the present composition with ease, additives which are generally used can be incorporated into the composition during or after the process of incorporating EAT into the binder, or before or after the composition is used.Examples of useful additives are a solution, solvent, auxiliary dispersant, viscosity adjusting agent, disinfectant, fungicide, coloring agent, plasticizer, precipitation preventing agent, flame retardant, catalyst, promotor, curing agent, auxiliary curing agent, antioxidant, aging preventing agent, and modifiers for adjusting hardness, adhesion and flexibility.

According to the present invention, the proportions of EAT and the binder are dependent on the contemplated purpose, and kinds of EAT and binder. When too small an amount of EAT is used, satisfactory conductive characteristics can not be obtained in respect of conductivity, antistatic effect, charge preventing effect, etc., whereas use of too small an amount of binder results in low binding ability, failing to give sufficient strength to the shaped product obtained. To assure usefulness, it is generally preferable to use 0.1 to 1000 parts (by weight, the same as hereinafter), more preferably 1 to 500 parts of EAT, per 100 parts by weight of the binder. Since EAT's of the present invention have various colors and are excellent as reinforcing fillers, compositions incorporating EAT are useful also for applications where the reinforcing property and/or the color will be utilized but substantially no use is made of the electrical properties thereof. Such a composition may be made conductive by other conductive substance incorporated therein. The compositions of the present invention include these compositions.

In the case where an unstable binder is used, the binder is likely to cure or cause curing in the natural atmosphere at room tempeature when it is admixed with other binder(s) or when the binders are further mixed with EAT and other additives, catalyst, etc. In such a case, the unstable binder should beheld separated until use and should be mixed with the other components immediately before use.

The present composition is curable with heat when the binder is thermosetting, or with ultraviolet rays or electron rays when the binder is photo-setting. If the binder is curable in the presence of moisture or anaerobically, the composition is cured in a corresponding special atmosphere. The composition may be cured in a vacuum or with application of pressure. Electrically conductive compositions of the present invention are usable singly or in the form of a mixture of at least two of them. Furthermore, the present composition is applicable to a substrate or an electrically conductive or insulating material to provide a composite material. For this purpose, any of conventional methods including coating and printing is usable.

The electrically conductive composition of the invention has high resistance to heat and chemicals and affords shaped products which are excellent in surface smoothness, strength and durability. The composition is usable for covers, sheets, other shaped articles, various composite materials and also as substitutes for members wherein metal is used as a conductive material, such as electromagnetic wave shields, electric circuits, electric contacts, etc.

The electrically conductive composition of the present invention is characterized in that it contains EAT.

EAT's which are generally fibrous, exhibit a reinforcing effect as well as conductive properties, therefore act also as reinforcing fillers and are very useful for industries. According to the use or purpose, the composition further incorporates additives or materials which are usually used, such as coloring pigments, extender pigments, reinforcing or non-reinforcing fillers, and reinforcing or non-reinforcing conductive fillers including platinum, gold, silver, copper, nickel, aluminum and carbon. The composition is then exhibit, in addition to excellent conductivity and reinforcing properties, heat resistance afforded by EAT, a particular metallic color given by EAT and orientation in conductivity if the fibrous EAT is arranged in a particular orientation. Thus, the composition has high industrial usefulness.

The present invention further provides conductive sheets or films (hereinafter referred to collectively as "sheets") which are prepared from the present conductive composition comprising EAT and a binder.

The conductive sheets of the invention are useful as hard copy materials, resistance materials, conductive materials, antistatic materials, charge preventing materials, electromagnetic wave shield materials, etc. These conductive sheets include those comprising a conductive portion only, those comprising at least one conductive layer and at least one insulating layer, those comprising at least two conductive layers of different conductivities, those comprising at least two conductive layers of different conductivities and at least one insulating layer, and those comprising a conductive layer and/or insulating layer which are/is partly cut out in the form of a desired pattern. At least one conductive layer of each of these sheets is composed of EAT.

The conductive sheets are prepared by a usual method, for example, by applying or spreading the present conductive composition to a releasable surface, by applying or spreading the composition to a sheet-like substrate layer such as paper, fabric of organic or inorganic fibers or resin film, or by forming a multi-layer structure in like manner. The composition can be made into a sheet directly by a suitable technique such as blow molding. Conductive sheets of the invention may have incorporated therein a usual modifier other than EAT and binder. The conductive sheets of the invention include those having a substrate layer.

The conductive sheets of the invention have high strength because EAT has excellent reinforcing properties. The sheet is adjustable in the orientation of its conductivity because EAT can be oriented in a particular direction when required. The sheet is stable because EAT is stable, is not susceptible to physical or chemical changes such as oxidation in the usual atmosphere and also has high heat resistance.

Thus the sheet is extremely useful for industries.

The present invention further provides pressure-sensitive conductive sheets or films (hereinafter referred to collectively as "sheets") comprising EAT and an elastic binder. These sheets have the characteristics of being substantially sensitive to an external pressure, which alters the conductivity of the sheet.

The elastic binders to be used for the pressure-sensitive conductive sheets of the invention are not particularly limited provided that they are pressure-sensitive or elastic. For example, among the binders exemplified above, those having elasticity or a linear or ladder-like structure are used. More specific examples are natural rubber, synthetic rubber, silicone rubber, urethane resin, vinyl chloride resin, acrylic resin, etc.

Preferred elastic binders are those having resilience of about 40 to 65% as measured according to JIS K 6301, Physical Test Method for Vulcanized Rubbers.

The pressure-sensitive conductive sheets of the invention can be prepared in the same manner as the conductive sheets with the exception of using an elastic binder as the binder.

The present invention will be described in greater detail with reference to the following examples, in which the volume resistivity was measured by the following method unless otherwise specified.

A form is placed on a Teflon sheet, and the composition is poured into the form to a thickness of 6 mm to obtain a specimen sheet, 2.0cm in width and 10.0cm in length. The thickness of the specimen is measured by a micrometer having precision of 0.01mm.

A silver foil is pressed into contact with each end face of the specimen, and two silver electrodes, 2.0 cm in length, are held in contact with the foiled end faces and spaced apart by 10.0cm. The electric resistance across the two electrodes is measured by a digital multimeter, TR-6841 (product of Takeda Riken Co., Ltd.).

The volume resistivity is calculated from the following equation.

thickness of sheet x lengthe of electrode x electric resistance Volume resistivity= distance between electrodes The surface resistivity is measured using a square sheet specimen, 10-cm-long in each side, prepared on a Teflon sheet in the same manner as above, or using a smooth-surfaced square specimen of the same size as above and at least 1.Omm in thickness. With use of a sample chamber Model TR-42 and digital multimeter TR-6841 (products of Takeda Riken Co., Ltd.), the resistance across the electrodes is measured. The surface resistivity is calculated from the following equation according to JIS K 6911.

# (D+d) Surface resistivity = x electric resistance D - d Under the above measuring condition, D and d are 7.0cm and 5.0cm, respectively.

TABLE 1 Kinds of Conductive Potassium Titanates No. 1 Reduced potassium titanate TISMO BK (product of Otsuka Kagaku Kabushiki laisha). Black No. 2 Cu-reduced type Titanate No. 1 as chemically Cu-plated. Cu/No. 1=2/1 (by weight). Titanate No. 1 was treated in chemical Cu plating bath (product of Ueno Seiyaku Co., Ltd.) at 400C for 15min with stirring. Metallic copper color.

No. 3 Ni-reduced type Titanate No. 1 as chemically Ni-plated. Ni/No.1= 2.5/1 (by weight). Treated in the same manner as No. 2 except using chemical Ni plating bath (product of Ueno Seiyaku Co., Ltd.) Silver white.

No. 4 Cu-TISMO type Potassium titanate (TISMO D, product of Otsuka Kagaku) was pretreated with palladium activating agent (product of Ueno Seiyaku), followed by the same treatment as for No. 2. Cu/TISMO D=3.5/1 (by weight).

Metallic copper color.

No. 5 Antimony type TISMO D as treated with antimony oxide-containing tin oxide. Sn02/TISMO D=2.5/1 (by weight). Methanol solution of antimony chloride and tin chloride (3/97 in mole ratio) was applied to TISMO D and dried in air, followed by baking at 700"C for 10min and then at 300 C for 3 hours. White.

No. 6 Cul - TISMO type Potassium titanate (TISMO L, product of Otsuka Kagaku) as treated with copper iodide. Cu 1/TISMO L=2/1 (by weight). TISMO L was dispersed in aqueous solution of sulfurous acid, 6.6% of copper sulfate and 8.7% of potassium iodide were added dropwise in equal amounts with stirring, and reaction product was filtered off, washed with water and dried at 50 C Pale yellow.

Note: Both TISMO D and TISMO L are electrical insulators.

Example 1 An electrically conductive thermosetting composition was prepared from 85 parts of conductive alkali metal titanate No.1 and 100 parts of epoxy resin (DER 324, product of Dow Chemical Corp.). The composition was heated to 50 C, and 21.5 parts of N- (2-aminoethyl)piperazine (curing catalyst) was then admixed therewith. The mixture was applied to a steel plate (SPCC-B) according to JIS G 3141 to a thickness of 5 mm and cured at 50 C for 30 minutes to form a 5 -mm-thick, cured conductive coating layer on the steel plate. The composition was found to have volume resistivity and surface resistivity of 1.01 ohm-cm and 170 ohms, respectively, by the foregoing methods.

The specimen obtained was tested for electrodeposition using electrodeposition alkyd resin (Watersol, product of Dainippon Ink & Chemicals Inc.), and the coating was baked at 1500C for 30 minutes. The resin was satisfactorily deposited on the surface of the conductive composition as well as at the interface between the composition and the steel plate. Thus, the composition exhibited good properties for use as a conductive backing composition.

Example 2 Thermosetting conductive compositions were prepared from conductive alkali metal titanate No. 3 in Table 1, the same binder as used in Example 1 and N-(2-aminoethyl)piperazine. In the same manner as in Example 1, each composition was checked for volume resistivity and surface resistivity, with the results shown in Table 2.

Before the measurement of resistivities, the specimen was heat-treated at 50 C for 30 minutes and then at 1500C for 30 minutes for curing.

Table 2

Electro- Volume resistance Surface resistance onductive Thick- Electric Volume Electric Surface No. alkali Binder ness esistance resistivity esistance resistivity titanate (mm) (#) (# # cm) (#) (#) -1 25 100 5.0 1.50x104 1500 1.03x105 1.94X106 @-2 50 100 5.1 798 81.4 1.23x103 2.31x104 -3 75 100 5.3 14.4 1.53 54.14 1020 @-4 100 100 4.8 7.81 0.75 44.05 830 -5 ~ 125 ~ 100 5.0 1.3 0.13 5.47 103 2-6 150 100 5.1 0.196 0.02 0.63 11.9 Example 3 Conductive setting compositions 3-1 to 3-11 listed in Table 3 were prepared from different conductive alkali metal titanates and binders in varying ratios. Table 4 shows the volume resistivities and surface resistivities of the compositions measured.

Table 3

Electro conductive No. alkali Binder O ther additive titanate Kind Parts Kind Parts Kind Parts Epoxy resin 3-1 2 100 100 Curing agent 21.5 (Ex. 1) Silicone resin 3-2 3 100 (Toray Silicone 100 Catalyst 2 Co Ltd) Acrylic resin 3-3 3 80 (Dainippon Ink and 100 Chemicals Inc) Amino # alkyd resin 3-4 3 30 (Dainippon Ink and 100 Xylene 30 Chemicals Inc) Phenolie resin 3-5 4 70 (Dainippon Ink and 100 Chemicals Inc) Polyester resin 3-6 4 50 (Dainippon Ink and 100 Curing agent 2 Chemicals Inc) T a b I e 3 (continued)

Electro conductive No. alkali B i n d e r Other additive titanate Kind Parts Kind Parts Kind Parts Alkyd resin -7 5 50 (Dainippon Ink and 100 Curing agent 0.2 Chemicals Inc) Polyamideresin Methanol 7 0 -8 6 5 (Torayzin 15 Isopropano 30 F-30) Silicone resin 9 1 50 (Toray Silicone 1 0 0 Catalyst 2 Co Ltd) -10 1 7-0 Urethane resin 1 0 0 F luorine-contained -11 1 1 30 resin (Daikin 1 0 0 Catalyst Industries Ltd) T a b l e 4

Volume resistance Surface resistance Thick- Electric Volume Electric Surface No. ness esistance resistivity resistance resistivity (mm) (#) (# # Cm) (#) 3-1 3.00 15.8 0.95 5.47 103 3-2 3.01 30.4 1.83 23.9 451 3-3 2.98 106 6.29 57.3 1080 3-4 4.99 2020 121 9.13X102 1072x104 3-5 3.00 3120 187 2.98x103 5.61X104 @-6 3.01 1.78x104 1070 1.17x104 2.21x105 @-7 3.05 3.85x104 2350 2.98x104 5.61x105 3-8 3.00 1.35X105 8100 5.79x104 1.09X106 @-9 3.03 3.14x104 1900 2.03x104 3.83x105 @-10 3.00 4180 251 2.28x103 4.29x104 3-11 3.00 3.50 0.21 5.15 97 Example 4 Coating compositions No.1 to No. 6 were prepared from titanate No. 1 listed in Table 1 and materials listed in Table 5 with use of a three-roll kneader. Table 5 shows the volume resistivity measurements of these compositions.

Table 5

Coating Tismo Acrylic Methyl Thick- Electric Volume composition resin ness esistance resistivity No. BK (* 1) cellosolve ( ) (#) (# # cm) 1 25 100 - 41 5.49X106 4500 2 50 100 25 35 2.47X105 173 3 100 100 100 30 6.42X103 3.85 4 125 100 150 25 2.00x103 1.00 5 150 100 200 25 1.66X103 0.83 (* 1) Elecond PQ-50B, product of Soken Kagaku Co.Ltd, Non-volatile=50% Example 5 Coating compositions No.21 to No.24 were prepared in the same manner as in Example 4 except that reduced potassium titanate (TISMO BK) which was chemically copper-plated was used as EAT along with the materials listed in Table 6. Table 6 also shows the volume resistivity measurements.

The reduced potassium titanate was chemically plated with copper by treating TISMO BK in a chemical copper plating bath (product of Ueno Seiyaku Co., Ltd.) at 40 C for 15 minutes with stirring. This treatment gave a conductive potassium titanate comprising TISMO BK coated with copper, having a copper/ TISMO BK ratio of 3/1 by weight and assuming a metallic copper color.

Table 6

Coating Electro- Epoxy Methyl Thick- Electric Volume composi- onductive resin cello- ness resistance resistivity tion- alkali solve No. titanate (* 1) ( ) (#) (# # cm) 2 1 30 100 - 45 2.22X10' 2000 2 2 130 100 50 37 1.38X104 10.2 2 3 170 100 100 28 2.14x102 0.12 2 4 220 100 150 19 2.10X102 0,08 (* 1 ) Araldite AZ-15, product of Ciba-Geigy AG.

7 parts of N-(2-auinoethyl)piperazine were used per 100 parts of the epoxy resin Example 6 Coating compositions No. 31 to No. 33 were prepared in the same manner as in Example 4 except that potassium titanate (TISMO D, product of Otsuka Kagaku Kabushiki Kaisha) coated with a white deposit of tin oxide containing antimony oxide was used as EAT along with the materials listed in Table 7. Table 7 also shows the volume resistivities of the compositions measured in the same manner as in Example 4.

The EAT used was prepared by applying a methanol solution of antimony chloride and tin chloride (3/ 97 in mole ratio) to TISMO D, drying the coating in air and baking the coating at 7000C for 60 minutes and then at 300 for 3 hours. The EAT had a tin oxide/TISMO D ratio of 2.5/1 by weight.

Table 7

Coating Electro-Acrylic Thick- Electric Volume composi- onductive mulsion Water | ness esistance esistivity tion alkali No. titanale (* 1) ( ) (#) (# # cm) 3 1 25 100 - 45 4.174X108 3.75x105 3 2 50 100 20 30 1.92X106 1.15X103 3 3 100 100 50 30 3.42X101 205 (* 1) Mowinyl 709, Non-volatile=50% Example 7 Coating compositions No.41 to No. 48 and comparison coating composition No. 1 listed in Table 8 were prepared in the same manner as in Example 4 with the exception of using the EAT's listed in Table 1 and other materials in different proportions. The compositions were tested for volume resistivity in the same manner as in Example 4.Table 9 shows the results.

Experimental Example 1 Some of the coating compositions obtained in Example 7 were checked.for surface resistivity by the foregoing method. Table 9 shows the results. Experimental Example 2 Specimens were prepared from some of the coating compositions of Example 7 in the same manner as the test specimens used for measuring the volume resistivity. The specimens were immersed in 0.5N hydrochloric acid or 0.5N sodium hydroxide at room temperature for 24 hours and then checked for volume resistivity and appearance. Table 10 shows the results.

Table 8

Coating Eleetro- conposi-conductive tion alkali B i n d e r Other additive No. titanate @ind Parts Kind Parts Kind arts Epoxy resin Methyl 4 1 1 1 2 0 1 0 0 150 (Ex. 2) cellosolve Epoxy resin Methyl cellosolve 100 42 3 100 100 (Ex. 2) silver powder 20 Acrylic Methyl 4 3 2 1 2 0 resin 100 100 (Ex. 1) cellosolve Amino # alkyd Methyl cellosolve 70 4 4 5 1 0 0 resin 1 0 0 (Oil-less) Butanol 30 Polyumide resin Methanol 40 4 5 6 4 0 (Toravzin 3 0 F-30) Propanol 60 Butyral resin Propanol 60 46 1 20 15 (Denki Katgaku) Butanol 40 4 7 1 1 0 0 Silicone resin 1 00 Xylene 50 Acrylic resin Methyl cellosolve 170 48 1120 100 (Ex. 1) Ketjenblack 30 Acrylic resin Coin. Ex. * 1 1 20 Methyl cellosolve 100 (Ex. 1) 100 (* 1) Electrolytic copper powder (EC -1110) Table 9

Volume resistance Surface resistance Thick- Electric Volume Electric Surface No. ness resistance resistvity resistance resistivity (mm) (#) (# # cm) (#) (#) 4 1 25 6.50x103 3.25 5.47 103 4 2 27 1.54x103 0.83 8.65 163 4 3 30 2.02X103 1.09 10.83 204 4 4 29 2.71x104 15.7 55.73 1050 4 5 27 9.59X104 51.8 168.3 3170 4 6 28 18.39x104 103 30.78 58000 4 7 32 4.50x103 2.88 16.19 305 4 8 30 3.27x103 1.96 21.76 410 Com. Ex. 25 2.26x103 1.13 7.27 137 Table 10

0.5N # HCl 0.5 N # NaOH Volume Volume No. resistivity Appearance resistivity Appearance (# # cm) (# # cm) 41 3.10 A 3.33 A 42 1.09 B 1.22 B 43 1.24 B 1.13 B 44 17.1 B 30.9 B 45 75.9 B 1 0 7 B 46 101 A 98 A 47 2.44 A 2.79 A 48 1.83 A 1.93 A Com.Ex. 6700 C 8 9 0 0 C A: No change B: Slightly faded C: Faded Example 8 Conductive compositions No. 8-1 to No. 8-5 were prepared from titanate No. 1 listed in Table 1 and the materials listed in Table 11 with use of a three-roll kneader. Conductive sheets No. 8-1 to No. 8-5 were prepared from these compositions and checked for volume resistivity and surface resistivity. Table 11 shows the results.

Table 11

Electro Epoxy Volume resistance Surface resistance conductive resin Thick- Electric Volume Electric Surface No. @@@@@@ ness resistance resistivity resistance resistivity @@@anate (*1) (mm) (#) (# # c.) (#) (#) @-1 15 100 5.21 1.83x104 2010 2.86X104 5.39X10s 5-2 50 100 5.77 8.75X102 101 9.40X102 1.77X104 8-3 75 100 5.91 48.3 5.71 26.1 492 -4 100 100 5.49 9.56 1.05 9.71 183 -5 120 100 5.83 7.98 0.93 5.36 101 Example 9 A conductive composition was prepared from 100 parts of titanate No. 5 in Table 1,20 parts of vinyl chloride resin 0.01 to lii in particle size, 25 parts of dioctyl phthalate, 0.3 part of dibutyltin maleate and 15 parts of 4,4'-isopropylidenediphenol (chromogenic material for dyes). The composition was applied to paper by a bar coater and heated at 160 C for 2 minutes to obtain a conductive sheet of 5g/m2 and 40 kiloohms in surface resistivity.

A mixture of 1.5 parts of Crystal Violet lactone, 1.5 parts of polyvinyl alcohol and 50 parts of water was applied to the conductive sheet by a bar coater and dried at 80 C for 5 minutes to obtain a conductive record paper having a coating layer containing an acid color forming dye and formed on the conductive sheet in an amount of 0.8g/m2.

When the record paper was used for a facsimile system for discharge breakdown record paper, hard copies were obtained with sharp blue images at a record speed of 1m/sec and a.c. voltage of 100V.

Example 10 Conductive sheets No.51 to No.59 in Table 12 were prepared in the same manner as in Example 8 except that different EAT's and different binders were used in varying proportions. The sheets were checked for volume resistivity and surface resistivity with the results given in Table 13.

Table 12

Coating Electro- composi - onductive tion alkali B i n d e r Other additive No. titanate Kind Parts Kind Parts Kind arts 5 1 1 1 5 OUrethane resin O O Ethyl cellosolve 50 Silicone resin 52 1 120 (Toray Silicone 100 Xylene 50 Co Ltd) Butyral resin 5 3 1 4 0 2 0 Butanol 150 (Denke Kagaku) Polyamide resin 5 4 2 60 (Torayzin 3 0 Isopropanol 100 F--30) Epoxy resin 55 3 85 100 (Ex. 1) Epoxy resin 56 4 100 100 (Ex. 1) Vinyl chloride A 25 5 7 5 1 2 0 resin 2 0 B 0.3 (Ex. 2) C 20 Vinyl chloride A 25 5 8 5 1 0 0 resin 2 0 B 0.3 -(Ex. 2) 9 C 15 Vinyl chloride A 30 5 9 6 8 5 resin 2 5 B 0.5 (Ex. 2) C 15 Epoxy resin Com. Ex.* 1120 100 Ethyl cellosolve 20 (Ex. 8) * 1 Electrolytic copper powder (EL-1110) A: Diootyl phthalate B: Dibutyltin saleate C: 4,4' - Isopropylidenediphenol Table 13

Volume resistance Surface resistance Thick- Electric Volume Electric Surface No. ness esistance resistivity resistance revs resistivity (mm) (#) (# # cm) (#) (#) 5 1 4.21 12.5 1.05 4.41 83.1 5 2 3.85 42.7 3.29 5.68 107 5 3 2.75 1.84X102 10.1 20.4 385 5 4 3.12 3.69 0.23 ;;.41X10- 10.2 5 5 1.08 89.3 1.93 3.99 75.1 5 6 2.01 2.96X103 119 59.4 1120 5 7 1.19 1.29X104 307 141 2650 5 8 3.62 1.42X10' 1030 .08X103 1.71X105 5 9 2.20 4.64x104 2040 2.10X104 3.95X10s Com.Ex. 3.01 | 17.9 1.08 4.16 78.3 Example 11 Fifty parts of titanate No. 1 listed in Table 1, 50 parts of dimethylpolysiloxane of the terminal hydroxyl brock type (product of Toshiba Silicone Co., Ltd., 20000cst.) and 12.5 parts of propioxyphosphonitrile (SR 200, product of Otsuka Kagaku Kabushiki Kaisha) were throughly mixed together by a three-roll kneader to obtain a conductive composition, to which 3 parts of methyltrimethoxysilane and 0.3 part of dibutyltin laurate were then added. The mixture was poured into the aforementioned form for preparing volume resistivity measuring specimens to obtain an elastic pressure-sensitive conductive sheet, 6.0mm in thickness, 2.0cm in width and 10.0cm in length.

The sheet was found to have a volume resistivity of 1050ohm-cm (875ohms in electric resistance).

The electric resistance of the sheet was 1780 ohms when measured with square electrodes, 1.0cmx 1.0cm, opposed to each other in contact with opposite surfaces of the sheet at the center thereof.

The resistance reduced to 3.2ohms when measured by the same electrodes in the same position with application of pressure thereto to compress the sheet to a thickness of 1.Omm. The volume resistivity was then 32ohm-cm. Thus the conductivity increased about 33 times.

Example 12 Pressure-sensitive conductive sheets No. 121 to No. 125 listed in Table 14 were prepared in the same manner as in Example 11 except that the amount of titanate used in Example 11 was varied. The sheets were checked for change in volume resistivity, with the results given in Table 14.

Table 14

Initial volume resistance Volume resistance E lectro- after compression @ampls couductive Thick- Eleclric Volume Thick- Electric Volume No. alkali ness resistance resistivity ness esistance resis- titanate tivity (mm) (#) (# # cm) (mm) (#) (# # cm) 1 2 1 5 6.0 5.06x107 6.02X106 1.0 261 2610 1 2 2 2 0 6.0 8.91X104 1.70X104 1.0 10.7 107 1 2 3 40 6.0 3,21X104 3850 1.0 5.95 59.5 1 2 4 8 0 6.0 1792 215 1.0 0.08 0.8 1 25 1 0 0 6.0 12.6 1.51 1.0 0.01 0.1 Example 13 Pressure-sensitive conductive sheets were prepared in the same manner as in Example 11 with the exception of using various EAT's and 100 parts of silicone rubber (TSE 200, product of Toshiba Silicone Co., Ltd.) as a binder to obtain test specimens No. 131 to No.136. In the same manner as in Example 11, the specimens were checked for change in volume resistivity. Table 15 shows the results.

Table 15

Initial volume resistance Volume resistance Electro- after compression Sample conductive Thick- Electric Volume Thick- Electric Volume No. alkali ness resistance resistivity ness resistance resis titanate tivity Kind Parts (mm) (#) (# # cm) (mm) (#) (# # cm) 131 1 30 6.0 8.58x104 1.03x104 1.0 7.10 71.0 132 2 30 6.0 7.34x104 8.81x103 1.0 5.33 53.3 133 3 30 6.0 7.52x104 9.02x103 1.0 4.29 42.9 134 4 40 6.0 2.21x105 2.65x104 1.0 9.01 90.1 135 5 50 6.0 1.60x105 1.92x104 1.0 6.33 63.3 136 6 50 6.0 1.38x105 1.66x104 1.0 7.68 76.8 Example 14 Pressure-sensitive condutive sheets were prepared in the same manner as in Example 11 with the exception of using different EAT's and binders in varying amounts to obtain test specimens NO. 141 to No.

150 listed in Table 16. In the same manner as in Example 11, the specimens were checked for change in volume resistivity. Table 17 shows the results.

Table 16

E lectro- Sample conductive No. alkali B i n d e r titanate Kind Parts K i n d IP arts 141 1 50 S B R 100 1 4 2 1 4 5 Neoprene rubber 1 0 0 1 43 2 3 5 Silicone rubber 1 0 0 (same as Ex. 11) 144 2 30 S B R 100 145 3 40 N B R 100 1 4 6 3 2 5 Chlorosulfonated rdbber 1 0b0 147 4 50 S B R 100 148 4 60 N B R 100 1 4 9 5 5 0 Chloroprene rubber 1 0 0 150 6 45 N B R 100 T a b l e 17

Initial volume resistance Volume resistance after compression Sample Thick- Electric Volume Thick- Electric Volume No. ness esistance resistivity ness resistance resins tivity (mm) (#) (# # cm) (mm) (#) (# # cm) 1 4 1 6.0 1.61X104 1.92X103 1.0 2.33 23.3 1 4 2 6.0 2.09X104 2.51X103 1.0 3.65 36.5 1 4 3 6.0 4.31X104 5.17X103 1.0 8.09 80.9 1 4 4 6.0 6.61X104 7.93X103 1.0 6.81 68.1 1 4 5 6.0 1.74X104 2.09X103 1.0 1.86 18.6 1 4 6 6.0 1.67X105 Z.O1X104 1.0 7.01 70.1 1 4 7 6.0 8.-27X104 9.93X103 1.0 6.53 65,3 1 4 8 6.0 9.01X104 1.08X103 1.0 7.91 79.1 1 4 9 6.0 1.71X105 2.05X10' 1.0 5.77 57.7 1 5 0 6.0 9.92X104 1.19X104 1.0 8.02 80.2

Claims (9)

1. A composition comprising an electrically conductive alkali metal titanate and a binder.

2. A composition as defined in claim 1 wherein the binder is at least one setting resin selected from the group consisting of amino resin, phenolic resin, alkyd resin, epoxy resin, urethane resin, polyamide resin, polyester resin, vinyl resin, polyimide resin, polymercapto resin, silicone resin, fluorocarbon resin, boron resin, organotitanium resin, inorganic settable substances such as silicate, phosphate and borate, mixtures of at least two of such materials, and prepolymers thereof.

3. A composition as defined in claim 1 wherein the binder is at least one selected from the group consisting of vaseline, linolin, petrolatum, bitumenous compounds, glycerin esters of fatty acids, polyalkylene oxides in the form of homopolymers or copolymers of alkylene oxides, alkylpolyalkylene oxides which are adducts of fatty acid glycerin oxides and alkylene oxides, and derivatives thereof, liquid polyethylene, liquid polypropylene and liquid acrylic resin.

4. A composition as defined in claim 1 wherein the binder is at least one selected from the group consisting of higher fatty acid derivatives, polyolefin compounds, rubbers, acrylic resin, vinyl ether resin, vinyl formal resin, vinyl acetal resin, cellulose resin, polyacetal, polysulfone, polyimidazole, polyoxazoline, polyoxazolam, mixtures or copolymers of at least two of these compounds.

5. A composition as defined in claim 1 wherein 0.1 to 1000 parts by weight of the electrically conductive alkali metal titanate is used per 100 parts by weight of the binder.

6. An electrically conductive shaped product which is prepared from a composition comprising an electrically conductive alkali metal titanate and a binder.

7. An electrically conductive shaped product as defined in claim 6 which is in the form of a sheet or film.

8. An electrically conductive sheet or film as defined in claim 7 wherein the binder is an elastic binder and the sheet or film is pressure-sensitive.

9. An electrically conductive sheet or film as defined in claim 8 wherein the elastic binder is at least one selected from the group consisting of natural rubber, synthetic rubber, silicone rubber, urethane resin, vinyl chloride resin and acrylic resin.