JPH05193074A - Electrostatic recording paper - Google Patents

Abstract

PURPOSE:To provide electrostatic recording paper excellent in conductivity and excellent in the compatibility with a conductive agent and a high resistance dielectric. CONSTITUTION:In electrostatic recording paper wherein a conductor and a high resistance dielectric are laminated on base paper, the conductor is composed of a linear irregularly-arranged polyolefinic resin with a wt. average molecular weight of 1000-50000 consisting of 45-98.5mol% of an olefin structural unit represented by general formula (I) (wherein R<1> is a hydrogoen atom or a methyl group), 0-15mol% of an acrylate structural unit represented by general formula (II) (wherein R<2> is a l-4C alkyl group), 0.5-5mol% of an alkylmaleimide structural unit represented by general formula III (wherein R<3> is a 8-18C alkyl group or a 8-18C aryl group) and 1-35mol% of a cationized maleimide structural unit.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to electrostatic recording paper.
More specifically, the present invention relates to an electrostatic recording sheet that can be suitably used as a printing sheet such as an electronic copying machine sheet and a high speed facsimile sheet.

[0002]

2. Description of the Related Art Generally, an electrostatic recording paper is coated with a polymer electrolyte such as polyvinylbenzyltrimethylammonium chloride or a conductive agent such as an ionic activator on one or both sides of a base paper, and the like. Obtained by applying a resistive dielectric.

However, all of these conductive agents exhibit hydrophilicity, but the high-resistance dielectric material has lipophilicity such as silicone, vinyl chloride resin, vinyl acetate type copolymer, polyacrylic acid ester and polystyrene. Since it is a resin to be exhibited, there is a problem that the affinity between the two is poor, it is difficult to uniformly apply the high resistance dielectric to the conductor, and the image becomes unclear.

Further, a conductive agent having a relatively small molecular weight, that is, having a weight average molecular weight of 1,000 or less migrates to a base paper or a high resistance dielectric with the passage of time, and has a problem of impairing recording performance. ..

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above prior art, and it is excellent not only in conductivity but also in affinity between a conductive agent and a high resistance dielectric. It is intended to provide an electrostatic recording sheet.

[0006]

The present invention is an electrostatic recording paper comprising a base paper and a conductor and a high resistance dielectric laminated on the base paper, wherein the conductor is represented by the general formula (I):

[0007]

[Chemical 9]

(Wherein R ¹ represents a hydrogen atom or a methyl group) 45 to 98.5 mol% of an olefin structural unit represented by the general formula (II):

[0009]

[Chemical 10]

An acrylate structural unit represented by the formula (wherein R ² represents an alkyl group having 1 to 4 carbon atoms) in an amount of 0 to 15 mol%, and a general formula (III):

[0011]

[Chemical 11]

(Wherein R ³ represents an alkyl group having 8 to 18 carbon atoms or an aryl group having 8 to 18 carbon atoms), and 0.5 to 5 mol% of an alkylmaleimide structural unit and the general formula (IV):

[0013]

[Chemical 12]

(In the formula, R ⁴ is an alkylene group having 2 to 8 carbon atoms, R ⁵ and R ⁶ are each an alkyl group having 1 to 4 carbon atoms, R ⁷ is an alkyl group having 1 to 12 carbon atoms, and 6 carbon atoms. 12 arylalkyl group, alicyclic alkyl group of the epoxy group or C6-12 2 to 4 carbon atoms which may be substituted by an alkyl group, X is a halogen atom, CH ₃ OSO ₃ or C ₂ H ₅ And a polyolefin resin having a weight average molecular weight of 1000 to 50000 and having a weight average molecular weight of 1000 to 50000, which is composed of 1 to 35 mol% of a cationized maleimide structural unit represented by OSO ₃ ) and a general formula (I):

[0015]

[Chemical 13]

(Wherein R ¹ is the same as above) 45 to 98.5 mol% of an olefin structural unit represented by the general formula (II):

[0017]

[Chemical 14]

(Wherein R ² is the same as above) 0 to 15 mol% of an acrylate structural unit represented by the general formula (V):

[0019]

[Chemical 15]

(Wherein R ¹ and R ³ are the same as above, m
Represents 0 or 1) and an alkylmaleimide structural unit represented by formula (VI): 0.5 to 5 mol%;

[0021]

[Chemical 16]

(Wherein R ¹ , R ⁴ , R ⁵ , R ⁶ , R ⁷ ,
X and m are the same as those described above) and contain at least one selected from polyolefin resins having a weight average molecular weight of 1000 to 50,000 linearly irregularly arranged and composed of 1 to 35 mol% of a cationized maleimide structural unit. The present invention relates to an electrostatic recording paper, which is a polyolefin resin.

[0023]

ACTION AND EXAMPLES As described above, the electrostatic recording paper of the present invention has the general formula (I):

[0024]

[Chemical 17]

(In the formula, R ¹ represents a hydrogen atom or a methyl group) 45 to 98.5 mol% of an olefin structural unit represented by the general formula (II):

[0026]

[Chemical 18]

(Wherein R ² represents an alkyl group having 1 to 4 carbon atoms) 0 to 15 mol% of an acrylate structural unit represented by the general formula (III):

[0028]

[Chemical 19]

(In the formula, R ³ represents an alkyl group or an aryl group having 8 to 18 carbon atoms), 0.5 to 5 mol% of an alkylmaleimide structural unit, and general formula (IV):

[0030]

[Chemical 20]

(Wherein R ⁴ is an alkylene group having 2 to 8 carbon atoms, R ⁵ and R ⁶ are each an alkyl group having 1 to 4 carbon atoms, R ⁷ is an alkyl group having 1 to 12 carbon atoms, and 6 carbon atoms. 12 arylalkyl group, alicyclic alkyl group of the epoxy group or C6-12 2 to 4 carbon atoms which may be substituted by an alkyl group, X is a halogen atom, CH ₃ OSO ₃ or C ₂ H ₅ Of the cationized maleimide structural unit represented by OSO ₃ ) having a weight average molecular weight of 1000 to 50000 and having a weight average molecular weight of 1000 to 50000 (hereinafter referred to as polyolefin resin A), and ( B) an olefin structural unit represented by the general formula (I) 45
98.5 mol% Acrylate structural unit represented by the general formula (II) 0-15 mol%, the general formula (V)

[0032]

[Chemical 21]

(Wherein R ¹ and R ³ are the same as above,
m represents 0 or 1) 0.5 to 5 mol% of an alkylmaleimide structural unit represented by the general formula (VI):

[0034]

[Chemical formula 22]

(Wherein R ¹ , R ⁴ , R ⁵ , R ⁶ , R ⁷ ,
X and m are the same as the above), and a polyolefin resin having a weight average molecular weight of 1000 to 50,000 and linearly irregularly arranged of 1 to 35 mol% of a cationized maleimide structural unit (hereinafter referred to as polyolefin resin B) At least one selected from the above is used as a conductor.

First, the polyolefin resin A and its intermediate will be described.

The proportion of the olefin structural unit represented by the general formula (I) in the polyolefin resin A is 45 to 9
It is 8.5 mol%. When the proportion of the olefin structural unit is less than 45 mol%, the glass transition point of the polyolefin resin A becomes high, which not only impairs the original flexibility of the resin but also causes many cationic groups. Nevertheless, the antistatic property is not so good, and 98.5 mol%
If it exceeds, the antistatic property of the polyolefin resin A becomes too small.

In the above olefin structural unit, R ¹ is a hydrogen atom or a methyl group, and these groups may be mixed in one molecule. The proportion of the olefin structural unit is preferably 85 to 97 mol% from the viewpoint of antistatic property and balance of glass transition point.

The above general formula (I
The ratio of the acrylate structural unit represented by I) is 0 to
It is 15 mol%. When the proportion of the acrylate structural unit exceeds 15 mol%, the softening point of the polyolefin resin A becomes low and tack and stickiness occur. In the present invention, when the acrylate structural unit is contained, toughness and impact resistance are imparted, which is preferable. In the present invention, the proportion of the acrylate structural unit is particularly preferably 1 to 15 mol%, especially 3 to 7 mol% from the viewpoint of the balance between the softening point and the toughness and impact resistance.

In the acrylate structural unit, R ²
Is an alkyl group having 1 to 4 carbon atoms. Specific examples of R ² include, for example, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group and the like, and these groups are mixed in one molecule. May be. Among these groups, the methyl group and the ethyl group are particularly preferable in maintaining the softening point of the polyolefin resin A.

The above general formula (I
The ratio of the alkylmaleimide structural unit represented by II) is
It is 0.5 to 5 mol%. The alkylmaleimide structural unit has the property of improving the compatibility with other polyolefin-based resins, improves the flexibility of the polyolefin-based resin A, and imparts the property of making the antistatic property less dependent on environmental humidity. It is a thing. When the proportion of the alkylmaleimide structural unit is less than 0.5 mol%, the compatibility with other polyolefin-based resins becomes particularly poor,
Further, if it exceeds 5 mol%, the antistatic property becomes small. Therefore, the proportion of the alkylmaleimide structural unit is preferably 1 to 3 mol% in terms of the compatibility and antistatic property.

In the alkylmaleimide structural unit represented by the general formula (III), R ³ is an alkyl group having 8 to 18 carbon atoms or an aryl group having 8 to 18 carbon atoms. From the viewpoint of compatibility with the polyolefin resin, a long-chain alkyl group having 16 to 18 carbon atoms is preferable.

The above general formula (I
The proportion of cationized maleimide structural units represented by V) is 1-35 mol%. When the proportion of the cationized maleimide structural unit is less than 1 mol%, the antistatic property becomes too small, and when it exceeds 35 mol%, the polyolefin resin A has hygroscopicity, and The compatibility with the polyolefin resin becomes poor. A preferable ratio of the cationized maleimide structural unit is 3 to 15 mol%.

In the cationized maleimide structural unit represented by the general formula (IV), specific examples of R ⁴ include, for example, ethylene group, propylene group, hexamethylene group,
Examples thereof include neopentylene group, and these groups may be mixed in one molecule. Among these groups, ethylene group and propylene group are preferable from the viewpoint of easiness of production of the polyolefin resin A of the present invention, economy and the like. R ⁵ and R ⁶ are alkyl groups having 1 to 4 carbon atoms, and specific examples of R ⁵ and R ⁶ include, for example, methyl group, ethyl group, propyl group and butyl group. It may be mixed in the molecule. Among these groups, a methyl group and an ethyl group are preferable in order to impart sufficient antistatic properties. R ⁷ has 1 carbon
Is an alkyl group having 12 to 12 carbon atoms, an arylalkyl group having 6 to 12 carbon atoms, an epoxy group having 2 to 4 carbon atoms which may be substituted with an alkyl group, or an alicyclic alkyl group having 6 to 12 carbon atoms. Of the above R ⁷ , in order to improve the heat resistance of the polyolefin resin A, a linear alkyl group or an arylalkyl group is preferable. Particularly preferred R ⁷ is
Examples thereof include a methyl group and an ethyl group. X is, for example, a halogen atom such as Cl, Br or I, CH ₃ OSO ₃ or C ₂ H ₅ OSO ₃ , and these may be mixed in one molecule. Among these, Cl, CH ₃ OSO ₃ and C ₂ H ₅ OSO ₃ are included from the viewpoint of antistatic property.
Is preferred.

The ratio of the alkylmaleimide structural unit represented by the general formula (III) to the cationized maleimide structural unit represented by the general formula (IV) (alkylmaleimide structural unit / cationized maleimide structural unit: molar ratio) Is 1/70 to 1/2, especially 1/70 to 1 in order to impart sufficient antistatic properties to the polyolefin resin A.
It is preferably 1/43.

The weight average molecular weight of the polyolefin resin A is 1,000 to 50,000. The weight average molecular weight is 1000
If the amount is less than 50%, the molecular weight becomes too small and volatilizes when the polyolefin resin A is heated.
If it exceeds 000, the viscosity of the polyolefin resin A when it is melted becomes too large and the workability becomes poor. The preferred weight average molecular weight is 3000 to 35000.

The weight average molecular weight as used herein means gel permeation chromatography (GP).
The monodisperse polystyrene-equivalent weight average molecular weight measured in C).

The above-mentioned polyolefin resin A cannot be easily measured because it is difficult to measure because it is hardly soluble in the usual gel permeation eluent such as tetrahydrofuran (THF) or xylene, but it can be easily measured by the ultra high temperature GPC method (Kinukawa, Taka It can be measured in accordance with Molecular Papers, Vol. 44, No. 2, pp. 139-141 (1987)).

45 to 98.5 mol% of the olefin structural unit represented by the general formula (I) which is an intermediate of the polyolefin resin A, and the acrylate structural unit represented by the general formula (II) 0 to
15 mol%, 0.5 to 5 mol% of an alkylmaleimide structural unit represented by the general formula (III) and the general formula (VII):

[0050]

[Chemical formula 23]

(Wherein R ⁴ , R ⁵ and R ⁶ are the same as those described above), the dialkylaminomaleimide structural unit having a weight average molecular weight of 1000 to 50000 randomly arranged in a linear arrangement of 1 to 35 mol%. The copolymer (hereinafter referred to as intermediate A) can be obtained, for example, by the following method.

First, the raw material of the intermediate A is not particularly limited, and for example, benzene, toluene or the like is used as a solvent in an autoclave to dissolve a radical polymerization initiator such as acrylate, maleic anhydride and benzoyl peroxide. Blowing a predetermined amount of olefin into the solution, 50
An olefin-acrylate-maleic anhydride copolymer obtained by a known method such as a method of reacting at -80 ° C for 8 to 12 hours, and then adding the content in the autoclave to a large amount of a solvent such as ether is known. can give. Here, the charged molar ratio of each monomer is almost equal to the ratio of the structural units of the target copolymer.

The method for producing the polyolefin resin A and its intermediate A from the above raw materials is not particularly limited, but one example thereof will be described below.

For example, benzene, toluene,
It is dissolved in an aromatic or aliphatic hydrocarbon such as xylene, cyclohexanone, decane, cumene or cymene, or an inert solvent such as a ketone, and first, an alkyl group having 8 to 18 carbon atoms is obtained to obtain a maleimide structure corresponding to the general formula (III). An amine is added and reacted at 130 to 180 ° C. to convert the acid anhydride group contained in the maleic anhydride structural unit into an alkylimide group. Then add dialkylaminoalkylamine,
All of the remaining maleic anhydride structural units are converted to dialkylaminoalkylmaleimide structural units by reacting at 130 to 180 ° C. to give Intermediate A. The amount of the alkylamine used is 1.4 to 83 mol%, preferably 1.4 to 30 mol% based on the acid anhydride group of the maleic anhydride structural unit so that the amount of the alkyl maleimide structural unit is 0.5 to 5 mol%.
Is. The amount of the dialkylaminoalkylamine used is 100 to 150 mol%, preferably 100 to 1 mol% with respect to the remaining maleic anhydride structural unit in order to adjust the dialkylaminoalkylmaleimide structural unit to 1 to 35 mol%.
It is 10 mol%.

The resulting intermediate A is further cation-modified with a known quaternizing agent such as alkyl halide, dialkyl sulfuric acid and epichlorohydrin to convert the dialkylaminoalkylmaleimide structural unit into a cationized maleimide structural unit. It is converted to obtain the polyolefin resin A.

Next, the polyolefin resin B and its intermediate will be described.

As described above, the polyolefin resin B is an olefin structural unit 45 represented by the general formula (I).
To 98.5 mol%, an acrylate structural unit represented by the general formula (II) 0 to 15 mol%, an alkylmaleimide structural unit represented by the general formula (V) 0.5 to 5 mol%, and a general formula (VI)
A cationized maleimide structural unit represented by 1 to 35 mol% of linearly irregularly arranged weight average molecular weight of 1000
It is a maleimide copolymer having a molecular weight of up to 50,000.

The proportion of the olefin structural unit represented by the general formula (I) in the polyolefin resin B is 45 to 9
It is 8.5 mol%. When the proportion of the olefin structural unit is less than 45 mol%, the glass transition point of the polyolefin resin B becomes high, and not only the original flexibility of the resin is impaired but also many cationic groups are present. Nevertheless, the antistatic property is not so good, and 98.5 mol%
If it exceeds, the antistatic property of the polyolefin resin B becomes too small. In the olefin structural unit, R ¹ is a hydrogen atom or a methyl group, and these groups may be mixed in one molecule. The proportion of the olefin structural unit is preferably 85 to 97 mol% from the viewpoint of antistatic property and balance of glass transition point.

The above-mentioned general formula (I
The ratio of the acrylate structural unit represented by I) is 0 to
It is 15 mol%. When the proportion of the acrylate structural unit exceeds 15 mol%, the softening point of the polyolefin resin B becomes low, and tack or stickiness occurs. In the present invention, when the acrylate structural unit is contained, it is preferable because it is imparted with toughness and impact resistance when blended with other polyolefin resins. In the present invention, the proportion of the acrylate structural unit is particularly preferably 1 to 15 mol%, especially 3 to 7 mol% from the viewpoint of the balance between the softening point and the toughness and impact resistance.

In the acrylate structural unit, R ²
Is an alkyl group having 1 to 4 carbon atoms. Specific examples of R ² include the same as the acrylate structural unit of the polyolefin resin A.

The above general formula in the polyolefin resin B
The proportion of the alkylmaleimide structural unit represented by (V) is
It is 0.5 to 5 mol%. The alkylmaleimide structural unit has the property of improving the compatibility with other polyolefin-based resins, improves the flexibility of the polyolefin-based resin B, and imparts the property of making the antistatic property less dependent on environmental humidity. To do. When the proportion of the alkylmaleimide structural unit is less than 0.5 mol%, the compatibility with other polyolefin resins becomes poor, and when it exceeds 5 mol%, the antistatic property decreases. .. Therefore, the proportion of the alkylmaleimide structural unit is preferably 1 to 3 mol% in terms of the compatibility and antistatic property.

In the alkylmaleimide structural unit represented by the general formula (V), R ³ is an alkyl group having 8 to 18 carbon atoms or an aryl group having 8 to 18 carbon atoms. From the viewpoint of compatibility with the polyolefin resin, etc., a long chain alkyl group having 16 to 18 carbon atoms is preferable.

The proportion of the cationized maleimide structural unit represented by the general formula (VI) in the polyolefin resin B is 1 to 35 mol%. When the ratio of the cationized maleimide structural unit is less than 1 mol%, the antistatic property becomes too small, and when it exceeds 35 mol%, the polyolefin resin B is blended with another polyolefin resin. At times, hygroscopicity occurs, and the compatibility with other polyolefin-based resins becomes poor. A preferable ratio of the cationized maleimide structural unit is 3 to 15 mol%.

In the cationized maleimide structural unit represented by the general formula (VI), R ⁴ , R ⁵ , R ⁶ and R
Specific examples of ⁷ and X include the same as the cationized maleimide structural unit represented by the general formula (IV) of the polyolefin resin A.

The ratio of the alkylmaleimide structural unit represented by the general formula (V) to the cationized maleimide structural unit represented by the general formula (VI) (alkylmaleimide structural unit / cationized maleimide structural unit: molar ratio)
Is 1/70 to 1/2, especially 1/70 to 1 /, in order to impart sufficient antistatic properties to the polyolefin resin B.
It is preferably 43.

The weight average molecular weight of the polyolefin resin B is 1,000 to 50,000. When the weight average molecular weight is less than 1000, the molecular weight becomes too small to volatilize when the polyolefin resin B is heated, and when it exceeds 50,000, the viscosity when melted becomes too large. , Workability becomes poor. A preferred weight average molecular weight is
3000 to 35000.

The weight average molecular weight of the polyolefin resin B can be measured in the same manner as the polyolefin resin A.

The polyolefin resin B and its intermediate (hereinafter referred to as intermediate B) can be obtained, for example, by the following method.

The method for producing the maleic anhydride graft-olefin-acrylate copolymer, which is a raw material of the intermediate B, is not particularly limited. For example, a commercially available low molecular weight polypropylene-ethyl acrylate copolymer is used. Obtained by graft polymerization of maleic anhydride in the presence of an organic peroxide such as benzoyl peroxide.

The olefin-acrylate copolymer grafted with maleic anhydride thus obtained is reacted with an alkylamine and a dialkylaminoalkylamine in the same manner as in the case of the polyolefin resin A, to give 45 to 98.5 mol% of olefin structural unit represented by formula (I), 0 to 15 mol% of acrylate structural unit represented by general formula (II), 0.5 to 5 mol% of alkylmaleimide structural unit represented by general formula (V) , And the general formula (VIII):

[0071]

[Chemical formula 24]

(Wherein R ¹ , R ⁴ , R ⁵ , R ⁶ and m
Is the same as the above), and an intermediate B having a weight average molecular weight of 1000 to 50,000 and linearly and irregularly arranged and composed of 1 to 35 mol% of a dialkylaminomaleimide structural unit is obtained.

The amount of the alkylamine used is 1.4 to 83 based on the grafted maleic anhydride structural unit so that the amount of the alkylmaleimide structural unit is 0.5 to 5 mol%.
Mol%, preferably 1.4 to 30 mol%. The amount of the dialkylamine used is 100 to 150 mol% with respect to the remaining maleic anhydride structural unit in order to adjust the dialkylaminoalkylmaleimide structural unit to 1 to 35 mol.
It is preferably 100 to 110 mol%.

Then, by reacting with a quaternizing agent similar to that used in the production of the polyolefin resin A, the polyolefin resin containing the grafted cationized maleimide structural unit represented by the general formula (VI) is used. You can get B.

Polyolefin resin A thus obtained
Both B and B have excellent antistatic properties, and the antistatic properties are not significantly affected by environmental humidity. Thus, the reason why the polyolefin resins A and B have excellent properties is not clear, but the cationized maleimide structural unit contained in the polyolefin resins A and B takes in water in the air, and X ⁻ is It is considered that this is due to the fact that it exhibits low electrical resistance because it ionizes and exhibits electrical conductivity. On the other hand, the alkylmaleimide structural units in the polyolefin resins A and B also have long alkyl groups in their side chains, so that the flexibility is improved and the antistatic property is excellent in being less dependent on environmental humidity. It is estimated that

Further, in the present invention, since the cationized maleimide structural unit does not exhibit volatility even at high temperature and is chemically incorporated in the polyolefin resin, it does not vaporize during processing, It is considered that blocking does not occur after processing.

In the present invention, the polyolefin resins A and B may be used alone or in admixture of two or more.

The electrostatic recording paper of the present invention is provided with a resin containing the above polyolefin resin as a conductor. As the conductor, the polyolefin resin alone or a mixture of the polyolefin resin and another polyolefin resin is used.

Examples of the other polyolefin resins include polyvinyl acetate, ethylene-vinyl acetate copolymer, saponified ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid copolymer, ethylene.
-(Meth) acrylic acid ester copolymer, ethylene-
Examples include (meth) acrylic acid-maleic anhydride terpolymer, ethylene- (meth) acrylic acid ester-maleic anhydride terpolymer, etc. These resins may be used alone or in combination of two or more. Used.

When the polyolefin resin and the other polyolefin resin are used in combination, the amount of at least one of the polyolefin resins A and B used is 100 parts by weight of the obtained resin for resin layer (weight: 1 part or more, preferably 5 parts or more with respect to 1 part, the same as the following), in order to impart antistatic properties.

The method of providing the conductor on the base paper is not particularly limited. For example, the conductor is made into an emulsion, and the reverse roll coating method, the gravure coating method,
Examples thereof include a coating method such as a bar coating method.

The thickness of the conductor after drying is appropriately adjusted according to the intended use of the electrostatic recording material, but is usually 0.
It is 1 to 5 μm, especially 0.5 to 3.0 μm.

On the formed conductor, 20 weight of a metal powder or inorganic fine particle having electron conductivity, which is plated with a metal such as gold, tin, or copper, according to the required electric resistance value, is added. If it is in the range of%, the resistance value may be controlled by adding it.

In the present invention, as the base paper, paper made of natural fiber pulp, synthetic paper made of synthetic resin fiber pulp, synthetic paper made of resin such as polycarbonate, styrene polymer, biaxially oriented polyester, polymethylmethacrylate, etc. However, the present invention is not limited to such examples.

As the high resistance dielectric material provided on the conductor layer formed on the base paper, known materials can be used. An example thereof is a high-conductivity resin mixed with inorganic fine powder.

The high dielectric resin has an electric resistance of 1 × 10 5.
A resin having a resistance of ¹² Ω or more. Specific examples thereof include vinyl chloride, vinyl acetate, vinyl acetal, vinylidene chloride, ethylene, styrene, butadiene, (meth) acrylic acid ester, and (meth) acrylic acid. Examples thereof include organic solvent-based or water-dispersed resins such as resins or copolymers having a single structure.

Examples of the inorganic fine powder include calcium carbonate, hydrated alumina sol, silica, and those whose surface is surface-treated with a titanate coupling agent and have a particle size of 2 μm or less.

The content of the inorganic fine powder in the high dielectric resin is usually 3 to 50 parts, especially 10 to 40 parts per 100 parts of the high dielectric resin.

The high resistance dielectric is provided on the conductor as an organic solvent solution such as emulsion or methyl ethyl ketone. The thickness of such a high resistance dielectric material after drying is appropriately adjusted according to the intended use of the electrostatic recording material, but is usually 0.5 to 10 μm, especially 5 to 7 μm.
Is.

Next, the electrostatic recording sheet of the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

Example 1 Formula:

[0092]

[Chemical 25]

85 mol% of olefin structural unit represented by the formula:

[0094]

[Chemical formula 26]

5 mol% of an acrylate structural unit represented by the formula:

[0096]

[Chemical 27]

1 mol% of an alkylmaleimide structural unit represented by the formula:

[0098]

[Chemical 28]

[0099] fine paper emulsion solution containing 24% by weight of cationized maleimide structural unit 9 mol% linear irregularly arranged with weight average polyolefin resin having a molecular weight of 31300 composed of represented by (basis weight: 60 g / m ² ) Was coated by the bar coating method to a thickness of 2 μm, and further, it was supplied to a hot air drying oven at 100 ° C. and dried. The thickness after drying was 0.5 μm.

After coating this conductor layer, the surface resistivity at a relative humidity (RH) of 20%, 40%, 60% or 80% at a temperature of 20 ° C. was measured according to the following method.
9.0 x 10 ⁷ Ω, 7.5 x 10 ⁷ Ω, 7.0 x 10 ⁷ Ω, 6.8 x 10
^It showed extremely excellent conductivity of ⁷ Ω, and the humidity dependence of the resistance value, which was a defect of the conductivity due to the conventional ionic conduction, was improved, and the humidity dependence of the resistance value was extremely small.

A fine powder of light calcium carbonate surface-treated with an ethylene-acrylic acid (acrylic acid concentration 20% by weight) copolymer and an ethylene-imine coupling agent on the surface of the base paper coated with the conductive layer. Was coated with a water-dispersed emulsion solution containing 20% by weight by a bar coating method to a thickness of 5 μm to form a high resistance dielectric layer, which was then supplied to a hot air drying oven at 110 ° C. for drying. This was placed in an atmosphere of 20 ° C. and 60% RH for 24 hours, and the humidity was adjusted to obtain an electrostatic recording paper. The back side of the coating layer of this electrostatic recording paper was reinforced with cellophane adhesive tape, and the cellophane adhesive tape was attached to the reinforced coating layer surface and quickly peeled off 180 °. No peeling was observed at each interface, and the cohesive failure of the high-quality paper caused the adhesive state to be good.

This electrostatic recording paper was mounted on a high-speed facsimile machine and image recording was carried out by using a magnet dry toner under the conditions of linear density of 8 liter / mm, pulse width of 12 μsec, applied voltage of pin electrode −300 V and sub electrode +300 V. Was done. The density of the obtained image was measured as a reflection density with a Macbeth densitometer (RD-100R type, manufactured by Macbeth Co.), and the result was 0.9 to 1.
A very high density recorded image was obtained.

(Surface specific resistance) Electrostatic recording paper 10 cm x 10 cm
Cut it out and leave it in a constant temperature and humidity room controlled at 20%, 40%, 60% or 80% RH at 20 ° C for 48 hours for aging.

After aging, the surface resistivity is measured in the atmosphere.

Measuring instrument: Ultra-insulator (VE-40 type) manufactured by Kawaguchi Electric Co., Ltd. and a room temperature measuring box (RD-02 type) connected Measuring conditions: Applied voltage 100 V Value measured by this instrument To adopt.

The surface resistivity is 1 × 10 ¹³ Ω
The following are excellent in conductivity.

Example 2 A conductor layer was formed in the same manner as in Example 1 except that the solid concentration of the polyolefin resin emulsion was 25% by weight and the thickness was 3 μm. .. The thickness of the conductor layer after drying was 0.7 μm.

Next, the support for electrostatic recording paper obtained above was smoothed by applying a super calendar. The surface resistivity of this product was 6.7 × 10 ⁷ Ω.

On the conductor layer, 35 g of calcium carbonate, 15 g of acrylic resin (LR472 manufactured by Mitsubishi Rayon Co., Ltd.),
An emulsion consisting of 80 mg of phthalic anhydride and 20 g of toluene was applied by a bar coating method to a thickness of 5 μm and dried to form a high resistance dielectric layer.

The back surface of the base paper of the obtained electrostatic recording paper was lined with cellophane adhesive tape, and then a peeling test of the coated surface was conducted with the cellophane adhesive tape, but no peeling of the coated surface was observed.

This electrostatic recording paper was mounted on a high-speed facsimile machine and an image was formed using a magnet dry toner under the conditions of linear density of 8 liters / mm, pulse width of 12 μsec, applied voltage of pin electrode −300 V and sub electrode +300 V. A record was made. Macbeth densitometer (RD-100R type,
As a result of measurement as reflection density by Macbeth Co.), 0.9-
A recorded image with an extremely high density of 1.2 was obtained.

Example 3 In Example 2, as the polyolefin resin, the alkylmaleimide structural unit has the formula:

[0113]

[Chemical 29]

An electrostatic recording paper was obtained in the same manner as in Example 2 except that the polyolefin resin represented by

When the physical properties of the obtained electrostatic recording paper were examined, peeling between the base paper and the conductive layer and between the conductive layer and the high resistance dielectric layer was not recognized, as in the case of the one obtained in Example 2. The image was excellent in recordability.

Example 4 In Example 1, the alkylmaleimide structural unit has the formula:

[0117]

[Chemical 30]

The cationized maleimide structural unit is represented by the formula:

[0119]

[Chemical 31]

An electrostatic recording paper was obtained in the same manner as in Example 2 except that the polyolefin resin represented by

When the physical properties of the obtained electrostatic recording paper were examined, peeling between the base paper and the conductive layer, and between the conductive layer and the high resistance dielectric layer was not recognized, as in the case of Example 2. The image was excellent in recordability.

Example 5 The same procedure as in Example 2 was repeated except that the polyolefin resin used in Example 2 and the polyolefin resin used in Example 4 were mixed at a weight ratio of 1: 1. I got the electrostatic recording paper.

When the physical properties of the obtained electrostatic recording paper were examined, peeling between the base paper and the conductive layer, and between the conductive layer and the high-resistance dielectric layer was not recognized, as in the case of Example 2. The image recording property was excellent.

Comparative Example 1 A 25% emulsion solution of a cationic polymer conductive agent (polyvinylbenzyltrimethylammonium chloride) was used as a conductor on the same base paper as in Example 2, and the film thickness after drying was 2 μm.
After being coated so as to be m, the same high resistance dielectric as in Example 2 was coated to obtain an electrostatic recording sheet.

The base paper surface of the obtained electrostatic recording paper was lined with a cellophane adhesive tape, and a peeling test of the coated surface was performed with the cellophane adhesive tape. As a result, peeling between the conductive layer and the high resistance dielectric layer was observed.

An image was recorded on this electrostatic recording sheet by the same method as in Example 2. As a result, although the image was similar to the present invention in terms of the reflection density of the image, image bleeding or recording unevenness was observed, which was unsatisfactory. It was something.

Comparative Example 2 A cationic polymer conductive agent (poly (N, N-
Dimethyl-3,5-methylenepiperidinium chloride)), and a styrene resin (Teisan Resin N101, manufactured by Teikoku Kasei Co., Ltd.) as a resin component for the high resistance dielectric layer.
Conducted using a 10% toluene solution in which 40% by weight of calcium carbonate is added to a 1.25: 1 (weight ratio) mixture of acrylic resin (Acridic 7-1021, manufactured by Dainippon Ink and Chemicals, Inc.). An electrostatic recording paper was obtained in the same manner as in Example 2.

The coated back surface of the obtained electrostatic recording paper was lined with a cellophane adhesive tape, and a peeling test of the coated surface was performed with the cellophane adhesive tape. As a result, a conductive layer and a high resistance dielectric film were obtained as in Comparative Example 1. Peeling between the body layers was observed.
Further, as a result of recording an image by the same method as in Example 2, defects such as bleeding and recording unevenness were recognized.

[0129]

The electrostatic recording paper of the present invention is excellent not only in conductivity but also in adhesiveness between the base paper, the conductor and the high resistance dielectric.

Therefore, the electrostatic recording sheet of the present invention can be suitably used in the information transmission field of the electrostatic recording system such as high speed facsimile.

Claims (1)

[Claims] 1. An electrostatic recording paper comprising a base paper and a conductor and a high resistance dielectric laminated on the base paper, wherein the conductor is represented by the general formula (I).
: [Chemical 1] (In the formula, R ¹ represents a hydrogen atom or a methyl group) 45 to 98.5 mol% of an olefin structural unit represented by the general formula (I
I): [Chemical 2] (In the formula, R ² represents an alkyl group having 1 to 4 carbon atoms) 0 to 15 mol% of an acrylate structural unit represented by the general formula (I
II): [Chemical Formula 3] (Wherein R ³ represents an alkyl group having 8 to 18 carbon atoms or an aryl group having 8 to 18 carbon atoms), and 0.5 to 5 mol% of an alkylmaleimide structural unit and the general formula (IV): (In the formula, R ⁴ is an alkylene group having 2 to 8 carbon atoms, R ⁵ and R ⁶ are each an alkyl group having 1 to 4 carbon atoms, R ⁷ is an alkyl group having 1 to 12 carbon atoms, and 6 to 12 carbon atoms. Arylalkyl group, 2 to 2 carbon atoms which may be substituted with an alkyl group
An epoxy group having 4 or an alicyclic alkyl group having 6 to 12 carbon atoms,
X is a halogen atom, CH ₃ OSO ₃ or C ₂ H ₅ OS
O ₃ ) and a polyolefin resin having a weight average molecular weight of 1000 to 50000 linearly and irregularly arranged of 1 to 35 mol% of a cationized maleimide structural unit, and a general formula (I): (In the formula, R ¹ is the same as above) 45 to 98.5 mol% of the olefin structural unit represented by the general formula (II): (Wherein R ² is the same as above) 0 to 15 mol% of an acrylate structural unit represented by the general formula (V): (In the formula, R ¹ and R ³ are the same as above, m is 0 or 1
Is represented by) and an alkylmaleimide structural unit represented by 0.5
~ 5 mol% and general formula (VI): (Wherein R ¹ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , X and m are the same as described above), and the cationized maleimide structural units represented by 1 to 35 mol% are linearly and irregularly arranged. An electrostatic recording paper comprising a polyolefin resin containing at least one selected from polyolefin resins having a weight average molecular weight of 1,000 to 50,000.