JPS61201255A - Insulating recording film - Google Patents

Abstract

PURPOSE:To obtain an image high in contrast and easy to be read by regulating at least one of a plastic film and an electrostatic latent image forming layer to a Hunter whiteness of >=50. CONSTITUTION:The plastic film is made of a usually known insulating thermoplastic resin or a thermosetting resin,and the electrostatic latent image forming layer is composed of an insulating binder resin, such as a thermoplastic resin or thermosetting resin, and a spacer means made of a filler. The insulating recording film having a Hunter whiteness of >=50 can be obtained by controlling at least one of the plastic film and the electrostatic latent image forming layer to a Hunter whiteness of >=50. To realize it, a white pigment is added to an thermoplastic resin or thermosetting resin or an org. or inorg. material or a gas contg. air is added or blended.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an insulating recording film used in an electrostatic recording system that directly converts an electrical signal into an electrostatic latent image. More specifically, recording is performed by sandwiching an insulating recording film in which an electrostatic latent image forming layer is laminated on a plastic film, and installing a recording electrode on the side of the electrostatic latent image forming layer and a toner developing device on the side of the plastic film. Insulation used for displays in electrostatic recording method (so-called "contrography")-1 Recently, a method has been proposed in which a toner visible image formed by electrostatic recording method is used for display purposes.

On the other hand, recently, an improvement method has been developed for the electrostatic recording method (so-called "powder contrastography") in which an insulating recording film in which an electrostatic latent image forming layer is laminated on a plastic film is sandwiched and a recording electrode toner developing device is installed to perform recording. have been proposed (for example, JP-A-57-1G 57.58, JP-A-57-1952.58, etc.). According to these proposals, the electrostatic latent image forming surface formed by the recording electrode and the toner developing device
Since it is possible to separate the image forming surface by ζ,
When used repeatedly as a master film, it is easy to clean and can extend the life of the recording medium.The process is also simpler than that of the conventional electrostatic recording method, so the equipment can be made smaller. .

The insulating recording film used in the above recording method is generally thin because if it is too thick, the resolution will be poor, so the film permeability during manufacture is important.

Sufficient mechanical strength is required for processability and repeated use as a master film.

In addition, in order to obtain stable image characteristics as a master film, the electrostatic latent image forming layer has side corona properties, old abrasion properties,
On the other hand, it has good charge retention under high humidity.

The toner image forming section has toner cleanability.

Toner filming properties and toner abrasion properties are required.

However, when a conventional insulating recording film on which a visible image of toner is formed is used for a display, it is advantageous to have a high contrast between the two images, and it is almost impossible to read the visible image of toner as is. It was impossible.

[Problem that the invention seeks to solve]

It is an object of the present invention to provide an insulating recording film that does not have the above-mentioned drawbacks, that is, an insulating recording film that can provide a visible image of toner that has high contrast and is easy to read.

[Failure to solve the problem]

The present invention has a nine-order configuration to achieve the objects stated in the following.

That is, in an insulating recording film used in an electrostatic recording method in which an insulating recording film in which an electrostatic latent image forming layer is laminated on a plastic film is sandwiched and a recording electrode and a toner developing device are provided for recording.

The present invention is characterized by an insulating recording film in which at least one of the plastic film or the electrostatic latent image forming layer has a Hunter whiteness of 50 or more.

The plastic film in the present invention is a film made of a commonly known insulating thermoplastic resin or thermosetting resin. The resins for this film include polyester, polyolefin, polyamide, polyester amide, polyether, polyimide, polyamideimide, polystyrene, poly(h-hon), poly(P-enylene sulfide), polyether ester, polychloride. Vinyl, poly(meth)acrylic acid ester, etc. are preferred.

Furthermore, copolymers, blends, and crosslinked products of these can also be used. Further, these resins are preferably stretched because they improve mechanical strength, dimensional stability, thermal properties, optical properties, and the like. Among these, polyester is preferably used. Here, the polyester is a polyester containing an aromatic dicarboxylic acid as a main acid component and an alkylene glycol as a main glycol component.

Specific examples of aromatic dicarboxylic acids include terephthalic acid,
Isophthalic acid, naphthalene dicarboxylic acid.

Diphenoxyethane dicarboxylic acid, diphenyl dicarboxylic acid, diphenyl ether dicarboxylic acid.

Diphenylmelphonicarboxylic acid, dienylketonedicarboxylic acid, anthracenedicarboxylic acid.

α,β-bis(2-chlorophenoxy)ethane-4,4
'-dicarboxylic acids and the like. Among these, terephthalic acid is particularly desirable.

Specific examples of alkylene glycol include ethylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, hexylene glycol, and the like. Among these, ethylene glycol is particularly desirable.

Of course, these polyesters may be homopolyesters or copolyesters (copolyesters), and examples of copolymerizable components include diethylene glycol, propylene glycol, neopentyl glycol, polyalkylene glycol, Diol components such as P-xylylene glycol, 1,4-cyclohexane dimetatool, and 5-sodium sulforesorcin.

Adipic acid, sebacic acid, phthalic acid, isophthalic acid, 2
, 6-naphthalene dicarboxylic acid, 5-1-)! Dicarboxylic acid component of Jumsulfoisophthalic acid.

Examples include polyfunctional dicarboxylic acid components such as trimellitic acid and pyromellitic acid, and oxycarboxylic acid components such as P-oxyethoxybenzoic acid.

The thickness of the plastic film is 5 μm to 50 μm.
It is preferable that More preferably 5 μm-25
It is desirable that it is μm. If it is thinner than this, the film will not have sufficient mechanical strength, and if it is thicker than this, the resolution will deteriorate, which is not preferable.

These plastic films may be subjected to known surface treatments, such as corona discharge treatment, plasma discharge treatment, anchor coating, etc., to improve adhesion, if necessary.

Also, as long as it does not impair the effects of the present invention.

Toner 9 Cleanability, 1IJ) A release agent may be added to improve toner filming properties.

A release agent may be applied on the surface opposite to the electrostatic latent image forming layer, or a release film may be laminated on top.

The electrostatic latent image forming layer consists of an insulating polymer, a binder and a spacer means. The linear polymer binder is made of a thermoplastic resin or a curable resin, and the base material is not particularly limited as long as it is a commonly known resin or filler. Insulating wire: high, outer triple binder: heat, plasticity, resin, for example 9. , moth, lyester, polyester, su, thylamide, polyvinyl acetal,
Polyvinyl chloride, polyurethane, acrylic ester, polyamide, polyurethane.

Polycarbonate, polystyrene, 4-polymethyl styrene, alkyd resin 9, polyamide-imide, silicon.

Base resins, fluororesins, copolymers and blends thereof, and curable resins that harden with heat, light, oxygen, etc., such as phenol resins, melamine resins, epoxy resins, crosslinked organosilicon compounds9 Examples include those obtained by adding a crosslinking agent to a poly(meth)winteric acid ester copolymer containing a reactive monomer to crosslink it. Among these, those obtained by adding a crosslinking agent to a poly(meth)acrylic acid ester copolymer containing a reactive monomer and crosslinking are particularly preferred.

Such reactive monomers include functional groups.

for example. Carboxyl group (for example, (meth)acrylic acid, etc.), water, acid group ((meth)1 acrylic acid 2-hydroquine, ethyl, etc.), amide group 1 ((ita)acrylic acid, etc.), amide group 1 ((ita)acrylic acid, etc.)
, lylic acid, amino1. Examples include compounds containing a glycidyl group ((meth)7cryl, acid glycidyl group, etc.), an amine group (2-diethylamineethyl (meth)acrylate, etc.), and the like. . , to these reactive moss and tsuma. As a crosslinking agent, voice, e, and ba are used.

Amino resin, epoxy resin9. Melami 1.4. ．． ．． N2
It is appropriately selected from resins, 9-isocyanates, 8-s, and the like. ,Additives such as Nehashi and accelerators may also be added. 4.

When the insulating polymer binder is used repeatedly,
When exposed to corona discharge, electricity, and ozone, ρ, which has good corona properties and side ozone properties, is preferably used. 1. Examples of such products include polycarbonates, polyesters, polystyrene copolymers, crosslinked poly(meth)alyl, sulfuric acid, and esterified polyesters, among others.

Typical combinations 5, etc. are particularly desirable.
1. As for the spacer, the quillani that constitutes the step.

It is used by appropriately selecting from among commonly known inorganic fillers and organic fillers. ,Ko,Re,Ra,9Fi,
Ra can be used alone or in combination of two or more.
stomach.

In addition, in terms of wear resistance during repeated use, the pacer means is an inorganic material with a Mohs hardness of 5 degrees or more.

Containing at least one type of colorant is preferred. Examples of such inorganic fillers include 9. For example, Akumi, O (9 on the Mohs scale), Steak, Ito (8 on the Mohs scale).

Suhi, Nek (8. entered, Quartz (7), Jill, Ko, Nia,.

(, ibid., 7), etc. are preferably used. These 1
．． Alumina is preferred even in □, and Schiff is used, especially 5α type crystal with purity of 11 degrees of 95, weight coefficient or higher, 1
Contains alkali and potassium metals! ,.

However, less is better. Furthermore, the porosity is most preferably small, moderately <11, and substantially 0.

,.

In the present invention,... The aforementioned plastin 1. Khufu 5, i.

Le, mu, ma, or static, electric, submerged,! Formation, layer 1. It is important to make the whiteness of at least one layer of Hunter 50 or higher.
, it is possible to obtain an insulating recording film having a diameter of 55.0 or more than 6 degrees. 8 Hands, 4 Lies 5, - Whiteness, 50 or above, 1 move 4 steps 1,
Strange 7, ha.

You can take any of the four appropriate methods. 1, 1
,(1) Pura, Hunter of Suchitkufi 9rum,
, white, year 1.

5.0 or more, we regret that (A) the above-mentioned, kneadable thermoplastic resin,! 9. Heat, hard particles, and a white pigment mixed into the resin, or (B), the substrate, become 8
, insulation, thermoplastic, plastic resin, resin 1. There is a difference in refractive index of 0.2 compared to that of gloss hardening.

(C) adding or blending an organic or inorganic material or a gas containing air; (C) matting at least one surface of the plastic film; (D)
) A white layer made of the above-mentioned insulating polymer binder and white pigment is laminated on at least one of the plastic films. Which method is adopted?

(2) In order to make the electrostatic latent image forming layer have a 7-intertone whiteness of 50 or more, (A) a white pigment is added to the layer.

Methods such as these are adopted.

Among these, (1) (A) * (D) 9 (
2) (A) is a preferred method. As such a white pigment, 9 commonly known pigments can be used. Among them, preferred compositions include titanium oxide, zinc oxide, antimony oxide, lithopone, basic lead carbonate, magnesium sulfate, barium sulfate, and the like. The average particle size of these white pigments varies depending on the thickness of the plastic film and the white layer, but is preferably 10 ILm or less, preferably 27μm.
The following is desirable.

These white pigments may be used alone or in combination. The amount of white pigment added depends on the thickness of the plastic film and white layer, but (1) (
In case of A), 6-50% by weight, (]) In case of (D), 60-80% by weight12) In case of (A), 925-80
It is preferable that the weight ratio be appropriately selected within the range of weight. If it is less than this range, whiteness cannot be obtained, while if it is thicker than this range, the strength of the film or membrane will be weakened, which is preferable.

The surface roughness of the electrostatic latent image forming layer of the present invention is 5 μm to 30 t.
Preferably h m. More preferably 5)
It is desirable that Lm~20/Zrn. If it exceeds this range, the discharge stability during recording will be poor and the image characteristics will be poor, which is not preferable. For this reason, the average particle diameter of the scrubber means is appropriately selected within the range of approximately 5) m to 60 μm, although it depends on the amount of coating.

When a white pigment is added to the electrostatic latent image forming layer, the weight ratio of polymer binder/spacer means/white pigment is 100/1 to 1.
It is preferable to select it appropriately within the range of 50,150 to 250. If it is smaller than this range, the discharge stability will be poor, while if it is thicker than this range, the film strength of the electrostatic latent image forming layer will be weak, which is not preferable.

In addition, in the spacer means, an inorganic filler with a Mohs hardness of 7 or more (referred to as filler (■)) and a Mohs hardness of 7 or more are used.
Inorganic filler or organic filler (filler (T
The weight ratio of filler (■)/filler (referred to as I) is
II) = 10010 to 10/90 is preferred from the viewpoint of wear resistance. Further, the average particle diameter is preferably filler (■)>filler (TI) from the viewpoint of abrasion resistance.

The electrostatic latent image forming layer may be a single layer or a plurality of laminated layers, and an intermediate layer such as an adhesive layer may be provided between the plastic film and the electrostatic latent image forming layer. .

Generally known methods can be effectively used to add the electrostatic latent image forming layer of the present invention. For example, brush painting, dip painting,
The coating is appropriately selected from knife coating, roll coating, spray coating, 9-turn flow coating (spinner, Whaler, etc.).

The electrostatic latent image forming layer of the present invention having a moisture absorption rate of 0.5% or less is particularly preferably used because it has good image characteristics under high humidity.

〔Effect of the invention〕

The present invention provides an insulating recording film in which an electrostatic latent image forming layer is laminated on the second layer of a plastic film. By this,
The visible image of the toner on the insulating recording film has a high contrast.

An image that is easy to read is obtained. As a result, it can be used very conveniently and repeatedly for display purposes, as well as for ordinary uses of insulating recording films.
For example, it can be used as a master film for facsimile machines or printers, or as a note copy film that is directly fixed.

[Method of measuring characteristics, evaluation criteria]

(1) Electrostatic copying paper testing device (EPA'-
Using S P-42'E3), apply a voltage of +5kv for 5 seconds on the electrostatic latent image forming layer of the insulating recording film to determine the electrostatic charge acceptance potential (Vo).9 Then, leave it for 60 seconds. The subsequent potential (v3o) is determined and the charge retention rate (-v5o
, 7 Vox 10.0C%)). It is preferably 80% or more.

(2) Moisture absorption The insulating recording film was treated in 20°065% RH for 24 hours, and then its weight was measured.WIL.Then, it was treated in a hot air open at 150°C for 15 hours, dried, and its weight was measured.W2. ).

Moisture absorption rate (%) = (w, -w2) / W2x 1-00
Calculated as

It is particularly preferable that the moisture absorption rate is 0.5% or less.

(3) Evaluation of image characteristics A Celti stylus recording electrode is placed on the surface of the electrostatic latent image forming layer with an insulating recording film in between, and a magnetic toner developing device is placed oppositely on the toner image forming surface. While bringing the tip of the magnetic brush with body toner into contact with the toner image forming surface of the insulating recording film, 800 V is applied between the multi-stylus recording electrode and the magnetic toner developing device to generate an electrostatic charge on the electrostatic latent image forming layer. The powder toner of the magnetic toner developing machine was held on the toner image forming surface by this electrostatic charge and visualized to obtain a toner image. .

Note that the insulating recording film is static-neutralized. The remaining toner was cleaned and used again and again. In addition.

Image contrast is made by Fuji Photo Film ■.

Fuji standard one piece (16 stages) was used. (4)
Surface roughness, Rt) Indicates the maximum roughness measured by a stylus surface roughness meter (cutoff 0.25 mnl, measured value 4rrrrrp, 1 =
59 average value).

(5) Hunter whiteness.

Made by Kollmorgen, using Macbeth 2:0.00,
a and 'b were measured, and Hunter whiteness (W) was calculated from the following formula (measured at 550 nm). , W −= 1
00-((-100-L)"10', a2+b2],,
,',<'Hereinafter, one embodiment of the present invention will be described based on Examples. The present invention is not limited to
211, -21, Example 1
P: A self-crosslinking acrylic emulsion was applied to one side of a 15 μm thick biaxially stretched polyester film 1 (“Lumirror” manufactured by Toshi ■) so that the thickness after drying was 0,
5) μm: After coating and spreading the adhesive layer,
4. Containing above all the white pigment shown in the first example. ,
＠, q latent image: After coating the formation area (after drying, the weight of one layer of i-electronic latent image formation is 1287 m'), Example 1) was obtained. - Insulated, sex records.

The various properties of the film are summarized in Table 2. Note that the surface roughness (Rt) is 17 μm. ”□Curvature 20μ
1. Forming an electrostatic latent image forming layer on one side of a biaxially oriented polyester film (containing a 1-color pigment (grained titanium, tan, etc.) (electrostatic latent image forming layer after drying) The weight of “g”
/n? ) Insulating recording film of the present invention (Example 2
) was obtained. The characteristics of the obtained insulating recording film were
It is summarized in the table.

Example 3 After corona discharge treatment was applied to both sides of a 15 μm thick biaxially stretched polyester film (“Lumirror” manufactured by Toshi ■), one side was treated with white pigment oxidation based on the weight part of thermally crosslinkable acrylic resin -10D. Titanium (average particle size 0.6 μm) 1
00 parts by weight of the white layer)-(Weight of the white layer after dry crosslinking-5g/')': Literary color: "a'1.("y
° A Shirasuk film was obtained. On the other side of the white layer of the layer 4≠Tsukufilm, it is shown as Table 1.
Coating the '7'i4 electrostatic latent image forming layer (after drying):
Electrostatic latent shrine Example 4:
After forming an adhesive layer by applying a crylic emulsion to a dry thickness of 0.5 μm, 0.01 μm of γ-glycidoxypropyl methyljethoxysilane was applied on top of the adhesive layer.
100 parts by weight of a hydrolyzate obtained by hydrolysis with an aqueous N-hydrochloric acid solution (containing a solid content of 61%), 45 parts by weight of an epoxy resin, and colloidal silica dispersed in methanol (solid content concentration 60%).
%), 9 parts by weight of aluminum acetylacetonate, 032 parts by weight of silicone surfactant, and 200 parts by weight of a 2/1 mixture of isopropyl alcohol/n-butyl alcohol as a solvent. A toner image forming layer was formed with a subsequent thickness of 6 μm. Next, on the opposite side of the toner image forming layer, an adhesive layer was formed using a self-crosslinking acrylic emulsion so that the thickness after drying was approximately 0.5 μm, and then an electrostatic layer containing the same white pigment as in Example 1 was applied. A latent image forming layer was applied (the weight of the electrostatic latent image forming layer after drying was 12 g/m') to obtain an insulating recording film of the present invention (Example 4). Various properties of the obtained insulating recording film are summarized in Table 2.

Example 5 The electrostatic latent image forming layer of Example 2 was coated on the white layer of the white plastic film obtained in Example 2 (the weight of the electrostatic latent image forming layer after drying was 8 g/m ”).

An insulating recording film (Example 5) of the present invention was obtained.

Various properties of the obtained insulating film are summarized in Table 2.

Table 2 shows the insulating recording film of the present invention.

Low adsorption and blending rate, good charge retention, stable images can be obtained even when used repeatedly, and high whiteness provides high contrast, allowing the visible image of the toner to be read as is.9 images It is clear that the properties are excellent.

Comparative Example 1 Biaxially stretched polyester film with a thickness of 15 μm (electronic
After forming an adhesive layer by applying a self-crosslinking acrylic emulsion to a dry thickness of 0.5 μm on one side of Lumirror (manufactured by Lumirror), the electrostatic latent image forming layer of Example 2 was applied on top of this. (The weight of the electrostatic latent image forming layer after drying is 8 g.
/') *Comparative example 1 was obtained. Various characteristics of Comparative Example 1 are summarized in Table 2.

Comparative Example 1 has a lower whiteness than Examples 1 to 5, so it is rated 1.
It has poor image characteristics and is unsuitable for display purposes.

Claims (1)

[Claims] (1) In an insulating recording film used in an electrostatic recording method in which an insulating recording film in which an electrostatic latent image forming layer is laminated on a plastic film is sandwiched and a recording electrode and a toner developing device are provided for recording, the plastic An insulating recording film characterized in that at least one of the film or the electrostatic latent image forming layer has a Hunter whiteness of 50 or more.