JPS6356500A - Eraser for correcting electrostatic process copying picture - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an eraser for correcting images formed by electrostatic copying, and particularly for correcting electrostatic copied images formed on plain paper. This invention relates to an eraser suitable for use in.

(Prior art and its problems) In general, the surface of a piece of paper has irregularities due to nine overlapping weavings of paper fibers. This cannot be completely erased with a pencil eraser.

Conventionally, in order to erase these images, the main methods used were to scrape off the area to be erased with the edge of a cutter knife, or to erase the area by rubbing with an abrasive eraser called a sand eraser. According to these methods 2
Other problems arise, such as being labor-intensive, and peeling off the fibers from the surface of the paper, which has been torn off, damages the surface of the paper, making it look unsightly, and making it impossible to write on it again.

(Means for Solving the Problems) In order to solve these problems, the present inventors have conducted various studies on the composition of the eraser.

In an eraser that contains a solvent that dissolves toner, if the weight of the plasticizer is small compared to the resin that is the base material of the eraser, the eraser will be hard and will remove the toner while dissolving it, so it will erase quickly. However,
In reality, it is not possible to take out the toner that is in the recesses on the paper surface and it cannot be completely erased, and if the weight of the plasticizer is large, the eraser is soft and dissolves the toner, but it is difficult to remove it from the paper surface. Erasing is slow because the force is weak, so after erasing with a hard eraser with a small amount of plasticizer, erase with a soft eraser with a large amount of plasticizer to erase the paper that could not be completely removed with a hard eraser with a small amount of plasticizer. It has been discovered that since the soft eraser comes into contact with the toner contained in the four parts, the toner can be dissolved and completely removed, making it possible to erase the toner.

The present inventors based on two or more findings.

It has been discovered that the problems of the conventional eraser can be eliminated by constructing the eraser containing a solvent that dissolves toner by using two types of erasers with different proportions of plasticizer to resin as a base material. This invention has finally been completed.

That is, the present invention provides an eraser containing a solvent with a boiling point of 120° C. or higher having the following conditions, in which the weight of the plasticizer with respect to the resin as a base material is 1.5 to α5 of the plasticizer to 1 of the resin. The object of the present invention is to provide an eraser for correcting electrostatic copying images, characterized in that it is composed of two types: a plasticizer and a plasticizer α5 to α2.

Conditions> When the hydrogen bonding force is weak, the solubility parameter (δ) is 7,
0 to 11.1 (m/d) 2 When the resultant hydrogen force is medium, the solubility parameter (δ) is 7,
4 to 14.7 (m/c'!) 2 or more 2 The present invention will be described in detail.

The solvent contained in the eraser may be any solvent that dissolves the toner and has a boiling point of 120° C. or more, preferably 200° C. or more, since it can be dispersed in the eraser raw material and heated and molded.

In addition, the solubility parameters of polystyrene, which is the main resin in the binder of toner, vary somewhat depending on the manufacturer and clade, but the values are 7.0 to 11 for (weak) hydrogen introduction power.
．． 1 ((alt/712).

(middle) and 7. a ~14.7 ((cat/crl
: ] 2).

Furthermore, depending on the grade and copolymer, the hydraulic bond strength (strong) may be q, s ~ 14. s ((aO1t
/d)2) Some have the value <.

For this reason, the solubility parameter is the hydrogen bonding force (
Weak) 7.0 to 11.1. (Medium) and Z4 to 14.5, and the above-mentioned boiling point is 120 ° C or higher, preferably 20 ° C.
The temperature will be 0°C or higher.

Specific examples of the above-mentioned solvents are shown in the following table.

These solvents can be used alone or in a mixture of two or more. Note that the solvents that can be used are not limited to those mentioned above.

The amount of solvent used is 5 to 50% by weight, preferably 5 to 50% by weight, based on the total amount of the eraser.

Next, the solvent can be contained in the eraser in the form of microcapsules with the solvent as a core material, or
A conceivable form is to contain it as a porous powder adsorbed with a solvent.

The former has the advantage of less deterioration in performance over time. Conventional methods such as the coacervation method, the powder bed method, the in-5-itu polymerization method, and the interfacial precipitation method can be used to produce microcapsules, and the microcapsules are easily destroyed by the pressure when using an eraser. It is fine as long as it is something.

Furthermore, although the latter has slightly inferior performance over time compared to the former, it has the advantage of being easier to manufacture and can be manufactured at low cost.

The porous powder may be appropriately selected from inorganic or organic materials that have a relatively large flow rate.

Specific examples include activated alumina, talc, bentonite, calcium carbonate, activated clay, and porous resin powder.

Note that the amounts of microcapsule material (wall material), porous powder, and solvent used are not necessarily uniform depending on the type of microcapsule, material, and porous powder, but are However, if the amount of solvent is too small, the erasing effect will be poor, and if it is too large, the solvent may seep into the eraser or migrate to the surface of the eraser, resulting in the formation of microcapsules. It is preferable to set the ratio (weight) of the material and the porous powder to the solvent in the range of 1:α4 to 1:10.

Next, the base material of the eraser, which is a feature of the present invention, will be described.

Conventionally known resins can be used as the eraser base material, and 2% preferably includes polyvinyl chloride, a copolymer of polyvinyl chloride and polyvinyl acetate, and these include 2% of known plasticizers, such as divinyl chloride and polyvinyl acetate. The eraser used in the present invention is one in which tylphthalate, dibutyl phthalate, etc. are added, but one eraser has a weight ratio of plasticizer to resin of 1 to 1.5.
~α5 and plasticizer Q,5~(L2).In other words, the weight of plasticizer to resin is 1.5 to 0 plasticizer to resin 1. ．．
5.

Plasticizer (15 to [1 and 2) can be molded and then combined to form a laminated structure to form a single eraser, or one of them can be crushed after molding,
By dispersing and mixing this into another molded product, one eraser is constructed. In the latter dispersion-mixing type eraser, it is preferable that the weight of the one dispersing 9 is 115 to 5 compared to the one surrounding it, with the weight of the surrounding one being 1. . In reality, if the number is less than 115, not much effect can be expected, and if it is more than 5, there will be problems in molding, and the eraser will become thick. In order to obtain an even better effect with this eraser, use one with a high proportion of plasticizer in the two dispersion-mixed parts, and one with a small proportion of plasticizer in the one surrounding it. good. This is because if you cover it with a material with a large amount of plasticizer, the entire structure will become soft and crumble easily, but if you use a structure with a hard material with a small amount of plasticizer, the entire structure will become hard and the eraser will have no force. This is because it is difficult to break down even if added, and it becomes easier to erase.

1. In the present invention, various fillers,
Of course, fragrances and the like can be added.

(Example) The present invention will be described in detail below based on examples.

Manufacturing method of microcapsules, powder bed method> 105 parts by weight of 2-phenoxyethanol (hereinafter simply referred to as “
%) and 67.5 parts of calcium carbonate were stirred and mixed to obtain 172.5 parts of a paste-like material.

This was stirred at high speed in 30 parts of ultrafine silica powder to obtain 202.5 parts of silica wall microcapsules.

Manufacturing method of eraser that is dispersed> Polyvinyl chloride (Geon 121. manufactured by Nippon Zeon ■) 1
00 parts dioctyl phthalate (plasticizer) 80 parts epoxidized soybean oil (stabilizer) 3 parts These ingredients were uniformly stirred and mixed to obtain 183 parts of a paste-like product, to which was added 44 parts of the silica-walled microcapsules. After stirring and mixing uniformly, press molding was performed at 110° C. for 20 minutes to obtain eraser A, which was cut into a size of about 1W square.

Manufacturing method of eraser> Polyvinyl chloride (Geon 121. Manufactured by Nippon Zeon ■) 1
00 parts・Dioctyl phthalate (plasticizer) 30 parts・
5 parts of epoxidized soybean oil These ingredients were uniformly stirred and mixed to obtain 135 parts of a paste-like product, and to this were added 30 parts of the aforementioned silica-walled microcapsules and 165 parts of the aforementioned cut eraser, and the mixture was uniformly stirred and mixed. after.

Eraser B was obtained by press molding at 110° C. for 20 minutes.

(Comparative example 1) Eraser AO in the above embodiment (however.

(uncut) (Comparative example 2) Eraser BO in the above example (however.

(Not containing Eraser A) (Effects of the Invention) When the erasers obtained in Examples and Comparative Examples 1 and 2 were used to erase images drawn on ordinary plain paper using the electrostatic printing method, comparison results were obtained. With the eraser of Example 1, the image became thinner, but the toner that had entered the recesses on the surface of the paper could not be removed and the image was not completely erased. Further, in the eraser of Comparative Example 2, the toner was not easily removed from the paper surface, which caused a practical problem. On the other hand, the eraser of the example was able to quickly and completely erase the image without damaging the paper surface.

The eraser for correcting electrostatographic images according to the present invention exhibits excellent effects.

Claims (1)

[Scope of Claims] An eraser containing a solvent with a boiling point of 120° C. or more and having the following conditions, wherein the weight of plasticizer to resin as a base material is 1.5 to 0.
5 and 2 with a plasticizer of 0.5 to 0.2.
An eraser for correcting electrostatic copying images, characterized in that it is composed of seeds. <Conditions> When the hydrogen bonding force is weak, the solubility parameter (δ) is 7.
0 to 11.1 (cal/cm^■)^1^/^2 When the hydrogen bond strength is medium, the solubility parameter (δ) is 7.4 to 1
4.7 (cal/cm^■)^1^/^2