JPH11334287A - Rubber based eraser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely erase in the case a trace of a pencil or a mechanical pencil is erased without staining a paper face by a method wherein at least regenerated rubber which does not contain carbon black, a filler, and an erasure improving agent are contained. SOLUTION: A blend wherein the raw material components are 17 wt.% of regenerated rubber, 22 wt.% of regenerated glass and heavy calcium carbonate, 52 wt.% of white factice, 0.5 wt.% of process oil, 0.5 wt.% of titanium oxide, 7 wt.% of magnesium oxide, 0.5 wt.% of TMTD, and 0.5 wt.% of precipitated sulfur, is well stirred and kneaded e.g. by a Banbury mixer or the like. Then, the mixture is molded by either one of molding methods of a compression molding, an extrusion molding and an injection molding, and a rubber based eraser of a proper shape is obtained. In the function maintenance of the obtained rubber based eraser for temperatures, the generation amount of waste of erasure at 60 deg.C or at 80 deg.C is not different from the generation amount at normal temperature. That is, this rubber based eraser is excellent in the performance maintenance at the time of a high temperature as compared with a TPE based eraser.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber-based eraser (generally referred to as an eraser) mainly composed of rubber for erasing handwriting of a pencil, a mechanical pencil or the like, and particularly to an environmental treatment problem. Used rubber products (waste rubber) that are disposed of as waste at the time of use
And a rubber-based eraser using

[0002]

2. Description of the Related Art Polyvinyl chloride (PVC) is blended with a plasticizer and an inorganic filler and the like is gelled by heating.
A system eraser is already known (Japanese Patent Publication No. 46-2924).
No. 9). As an eraser using a used rubber product, for example, a thermoplastic elastomer (TP
E), there is known a TPE-based eraser obtained by blending used tire powder (waste tire powder) as a filler and eraser improving agent (see JP-A-5-345499).

[0003]

However, since the above-mentioned conventional TPE-based eraser uses tire powder of used tires of automobiles and the like, it is necessary to erase the handwriting of a pencil or a mechanical pencil from the paper. Sometimes, when the eraser is rubbed against the paper surface, carbon black contained in a large amount in the tire powder is transferred to the paper surface, and the paper surface may be stained black. In other words, the cause of soiling the paper surface is the presence of carbon black contained in the TPE-based eraser, and when the eraser is rubbed against the paper surface, the carbon black may remain as black streaks on the paper surface. Was desired.

[0004] Further, the conventional TPE-based eraser uses a thermoplastic elastomer which is inferior in heat property, and thus has a problem in maintaining performance at high temperatures. Specifically, the thermoplastic elastomer is softened by the softening of the polymer in a high-temperature atmosphere of, for example, 60 ° C. to 80 ° C., and the amount of erased dust generated when handwriting is erased increases. In other words, the conventional eraser using a thermoplastic elastomer has an abnormally large amount of eraser dust generated at the time of erasing and is intensely consumed, so that its life is short and uneconomical.

The present invention has been made in view of such circumstances as described above, and an object of the present invention is to provide a method for erasing handwriting such as a pencil or a mechanical pencil without soiling the paper surface. An object of the present invention is to provide a low-cost rubber-based eraser which is made of waste rubber products (waste rubber) which is excellent in heat resistance and is excellent in environmental protection.

[0006]

Means for Achieving the Object To achieve the object, the present invention is greatly characterized in that it contains at least a recycled rubber not containing carbon black, a filler, and a eraser. Specifically, the used rubber product containing no carbon black is processed and regenerated by a well-known reclaimed rubber production method. Recycled rubber, filler, eraser, further softener, colorant, vulcanization accelerator, Vulcanization accelerator, vulcanizing agent These raw materials are contained in a required amount (% by weight).

Further, the present invention is directed to a used rubber powder containing no carbon black, a natural rubber, a synthetic rubber emulsion rubber or a polypropylene or polyethylene plastic alone or a composite material thereof, a filler, and an improved eraser. There is a great feature in that the composition contains at least an agent.
Specifically, used rubber products that do not contain carbon black are processed and pulverized to a predetermined particle size by a well-known rubber powder manufacturing method, and natural rubber, filler, eraser, and softener are added to the used rubber powder. , Colorant, vulcanization accelerator, vulcanization accelerator, vulcanizing agent.
It is contained in.

In the present invention, used rubber products which do not contain a carbon rack used as recycled rubber and used rubber powder include white rubber such as rubber bands and rubber gloves.
The particle diameter of the used rubber powder is 1 mm or less, preferably 0.5 mm or less, particularly preferably 0.3 mm or less.
Examples of the filler include heavy calcium carbonate, inorganic powders such as recycled glass powder, and the average particle diameter of the inorganic powder is in the range of 1 to 120 μm. And a white sub such as a compound obtained by adding sulfur chloride. In particular, a white sub using a compound obtained by adding sulfur chloride to regenerated rapeseed oil (hereinafter simply referred to as white sub) is desirable. Further, examples of the softening agent include process oil and the like. In addition, examples of the coloring agent include titanium oxide.
In addition, examples of the vulcanization accelerator include magnesium oxide. Examples of the vulcanization accelerator include tetramethylthiuram disulfide (hereinafter abbreviated as TMTD). The vulcanizing agent includes precipitated sulfur and the like.

According to the rubber-based eraser according to the above-described technical means of the present invention, when erasing a handwriting such as a pencil or a mechanical pencil from the paper surface, the paper surface becomes dirty even if the eraser is rubbed against the paper surface. There is no. That is, since carbon black, which causes soiling of the paper surface, is not included in the eraser, there is no possibility that the paper surface will be soiled. In addition, since it is excellent in heat resistance, there is no possibility that a problem occurs in maintaining performance at high temperatures. That is, the amount of erase dust generated at the time of erasing can be suppressed to the same state as at normal temperature.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail with reference to specific examples. The rubber-based eraser of the present invention according to claims 1 and 4 contains at least a recycled rubber not containing carbon black, a filler, and a character eraser as essential components. Specifically, used rubber products that do not contain carbon black, such as rubber bands and rubber gloves, are processed and reclaimed by a well-known reclaimed rubber production method. , Titanium oxide, magnesium oxide, TMT
D, Precipitated sulfur These are required to be contained in a required amount (% by weight). In addition, heavy calcium carbonate used as a filler, recycled glass powder has an average particle diameter of 1 to 120μ
m is desirable.

Example 1 Recycled rubber 17% by weight Recycled glass powder, heavy calcium carbonate 22% by weight White sub 52% by weight Process oil 0.5% by weight Titanium oxide 0.5% by weight Magnesium oxide 7% by weight TMTD 0.5% by weight Precipitated sulfur 0.5% by weight % After well mixing and kneading the above raw materials with a well-known eraser production method, for example, a Banbury mixer or the like, the kneaded material is molded by any one of compression molding, extrusion molding, and injection molding to obtain an appropriately shaped rubber system. Get an eraser.

Further, the rubber-based eraser of the present invention according to claims 1 to 2 and 4 contains at least a recycled rubber not containing carbon black, a natural rubber, a filler, and a character eraser as essential components. . Specifically, natural rubber, heavy calcium carbonate, recycled glass powder, white sub, process oil, titanium oxide, magnesium oxide, TMTD, and precipitated sulfur are added to the above-mentioned recycled rubber in a required amount (% by weight). It is to contain.

Example 2 Recycled rubber 11% by weight Natural rubber 6% by weight Recycled glass powder 22% by weight heavy calcium carbonate 52% by weight White oil 0.5% by weight Titanium oxide 0.5% by weight Magnesium oxide 7% by weight TMTD 0.5% by weight 0.5% by weight of precipitated sulfur

Example 3 Natural rubber 11% by weight Recycled rubber 6% by weight Recycled glass powder 22% by weight heavy calcium carbonate 52% by weight Process oil 0.5% by weight Titanium oxide 0.5% by weight Magnesium oxide 7% by weight TMTD 0.5% by weight 0.5% by weight of precipitated sulfur

Next, a function retention test with respect to temperature of the rubber-based eraser of the present invention obtained in each of Examples 1 to 3 and the conventional TPE-based eraser was performed under the following test conditions. Table 1 shows the results. Here, ○ shown in the table indicates that the amount of erased dust is not different from that at normal temperature, Δ indicates that the amount of erased dust is about twice that at normal temperature, and × indicates the amount of erased dust. It shows that the generation amount is about three times that at normal temperature. Test conditions Pencil used: HB of pencil specified in JIS S 6006 Test paper: Paper A specified in JIS P 3201 Room temperature: 23 ° C Heater: Key-type heat aging tester

[0016]

[Table 1]

As is clear from Table 1, the rubber-based eraser of the present invention shows that the amount of erased dust at 60 ° C. and 80 ° C. in each of Examples 1 to 3 is less than that at room temperature. It turns out that it does not change. On the other hand, in the case of the conventional TPE-based eraser, the amount of erased dust at 60 ° C. is about twice that at normal temperature, and at 80 ° C., the amount of erased dust is about three times that at normal temperature. Accordingly, it can be seen that the rubber-based eraser of the present invention is superior in maintaining performance at high temperatures as compared with the conventional TPE-based eraser.

The rubber-based eraser of the present invention according to claim 3 or 4 is a rubber-based eraser which does not contain carbon black as an essential component, natural rubber, synthetic rubber emulsion rubber or polypropylene or polyethylene plastic. It is to contain at least a simple substance or a composite material thereof, a filler, and a eraser. Specifically, used rubber products that do not contain carbon black are processed and pulverized to a predetermined particle size by a well-known rubber powder manufacturing method, and natural rubber, heavy calcium carbonate, recycled glass powder, white powder , Process oil, titanium oxide, magnesium oxide, TMTD, precipitated sulfur, etc. in a required amount (% by weight). The particle diameter of the used rubber powder not containing carbon black used in the present invention is 1 mm or less, preferably 0.5 mm or less, particularly preferably 0.3 mm or less. In these examples, the amounts (% by weight) of the respective raw material components are basically the same as those of the above-described Examples 1 to 3, and thus the description thereof is omitted.

[0019]

Since the rubber-based eraser of the present invention is constituted as described above, the following effects are obtained. . When erasing handwriting such as a pencil or a mechanical pencil from the paper surface, the paper surface is not stained even if an eraser is rubbed against the paper surface. That is, since carbon black, which is a factor that stains the paper surface, is not included in the eraser, there is no risk of soiling the paper surface. In addition, there is no fear that a problem occurs in maintaining the performance at a high temperature. That is, the amount of erase dust generated at the time of erasing can be suppressed to the same state as at normal temperature.

[0020] As a used filler, the used recycled glass powder that serves as an abrasive when rubbed against the paper surface is used, so it is possible to reduce costs, as well as handwriting such as pencils and mechanical pencils from the paper surface. When erasing characters to be erased, an excellent erasing effect can be obtained with a light force without strongly rubbing the paper. That is,
An excellent erasing effect (erasing performance) can be obtained in which handwriting such as a pencil or a mechanical pencil penetrating into the fibers of the paper surface, that is, graphite, is erased from the paper surface by contacting it with the eraser.

Therefore, according to the present invention, since recycled rubber or used rubber powder containing no carbon black is used, when erasing a handwriting such as a pencil or a mechanical pencil, a carbon fiber such as a conventional TPE-based eraser is used. There is no danger that the black will transfer to the paper surface and stain the paper surface, and the handwriting can be erased reliably and neatly. Moreover, 60
To provide a rubber-based eraser that is effective for environmental protection, which is expected to have many effects such as longer life than conventional TPE-based erasers because of its excellent heat resistance against a high temperature atmosphere of ℃ to 80 ° C. Can be.

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[Procedure amendment]

[Submission date] August 12, 1999

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document name]

[Title of the Invention] Rubber eraser

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber-based eraser (generally referred to as an eraser) mainly composed of rubber for erasing handwriting of a pencil, a mechanical pencil or the like, and particularly to an environmental treatment problem. Used rubber products (waste rubber) that are disposed of as waste at the time of use
And a rubber-based eraser using

[0002]

2. Description of the Related Art Polyvinyl chloride (PVC) is blended with a plasticizer and an inorganic filler and the like is gelled by heating.
System eraser is already known (JP-B-4 9 -2924
No. 9). As an eraser using a used rubber product, for example, a thermoplastic elastomer (TP
To E), used tires powder (powder of waste tires), and is TPE based eraser made by blending the eraser enhancers known as a filler (see JP-flat 5-345499).

[0003]

However, since the above-mentioned conventional TPE-based eraser uses tire powder of used tires of automobiles and the like, it is necessary to erase the handwriting of a pencil or a mechanical pencil from the paper. Sometimes, when the eraser is rubbed against the paper surface, carbon black contained in a large amount in the tire powder is transferred to the paper surface, and the paper surface may be stained black. In other words, the cause of soiling the paper surface is the presence of carbon black contained in the TPE-based eraser, and when the eraser is rubbed against the paper surface, the carbon black may remain as black streaks on the paper surface. Was desired.

[0004] Further, the conventional TPE-based eraser uses a thermoplastic elastomer which is inferior in heat property, and thus has a problem in maintaining performance at high temperatures. Specifically, the thermoplastic elastomer is softened by the softening of the polymer in a high-temperature atmosphere of, for example, 60 ° C. to 80 ° C., and the amount of erased dust generated when handwriting is erased increases. In other words, the conventional eraser using a thermoplastic elastomer has an abnormally large amount of eraser dust generated at the time of erasing and is intensely consumed, so that its life is short and uneconomical.

The present invention has been made in view of such circumstances as described above, and an object of the present invention is to provide a method for erasing handwriting such as a pencil or a mechanical pencil without soiling the paper surface. An object of the present invention is to provide a low-cost rubber-based eraser which is made of waste rubber products (waste rubber) which is excellent in heat resistance and is excellent in environmental protection.

[0006]

Means for Achieving the Object To achieve the object, the present invention is greatly characterized in that it contains at least a recycled rubber not containing carbon black, a filler, and a eraser. Specifically, the used rubber product containing no carbon black is processed and regenerated by a well-known reclaimed rubber production method. Recycled rubber, filler, eraser, further softener, colorant, vulcanization accelerator, Vulcanization accelerator, vulcanizing agent These raw materials are contained in a required amount (% by weight).

[0007] Further, the present invention is used rubber powder containing no carbon black, natural rubber, charge Hamazai great feature that comprising at least erasers improver. Specifically, a used rubber product which does not contain carbon black is processed and pulverized to a predetermined particle size by a well-known rubber powder manufacturing method, and the used rubber powder is used as a natural rubber, a filler, a eraser,
Further, a softener, a colorant, a vulcanization accelerator, a vulcanization accelerator, and a vulcanizing agent are required to contain these raw materials in a required amount (% by weight).

In the present invention, used rubber products which do not contain a carbon rack used as recycled rubber and used rubber powder include white rubber such as rubber bands and rubber gloves.
The particle diameter of the used rubber powder is 1 mm or less, preferably 0.5 mm or less, particularly preferably 0.3 mm or less.
Examples of the filler include heavy calcium carbonate, inorganic powders such as recycled glass powder, and the average particle diameter of the inorganic powder is in the range of 1 to 120 μm. And a white sub such as a compound obtained by adding sulfur chloride. In particular, a white sub using a compound obtained by adding sulfur chloride to regenerated rapeseed oil (hereinafter simply referred to as white sub) is desirable. Further, examples of the softening agent include process oil and the like. In addition, examples of the coloring agent include titanium oxide.
In addition, examples of the vulcanization accelerator include magnesium oxide. Examples of the vulcanization accelerator include tetramethylthiuram disulfide (hereinafter abbreviated as TMTD). The vulcanizing agent includes precipitated sulfur and the like.

According to the rubber-based eraser according to the above-described technical means of the present invention, when erasing a handwriting such as a pencil or a mechanical pencil from the paper surface, the paper surface becomes dirty even if the eraser is rubbed against the paper surface. There is no. That is, since carbon black, which causes soiling of the paper surface, is not included in the eraser, there is no possibility that the paper surface will be soiled. In addition, since it is excellent in heat resistance, there is no possibility that a problem occurs in maintaining performance at high temperatures. That is, the amount of erase dust generated at the time of erasing can be suppressed to the same state as at normal temperature.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail with reference to specific examples. The rubber-based eraser of the present invention according to claims 1 and 4 contains at least a recycled rubber not containing carbon black, a filler, and a character eraser as essential components. Specifically, used rubber products that do not contain carbon black, such as rubber bands and rubber gloves, are processed and reclaimed by a well-known reclaimed rubber production method. , Titanium oxide, magnesium oxide, TMT
D, Precipitated sulfur These are required to be contained in a required amount (% by weight). In addition, heavy calcium carbonate used as a filler, recycled glass powder has an average particle diameter of 1 to 120μ
m is desirable.

Example 1 Recycled rubber 17% by weight Recycled glass powder, heavy calcium carbonate 22% by weight White sub 52% by weight Process oil 0.5% by weight Titanium oxide 0.5% by weight Magnesium oxide 7% by weight TMTD 0.5% by weight Precipitated sulfur 0.5% by weight % After well mixing and kneading the above raw materials with a well-known eraser production method, for example, a Banbury mixer or the like, the kneaded material is molded by any one of compression molding, extrusion molding, and injection molding to obtain an appropriately shaped rubber system. Get an eraser.

Further, the rubber-based eraser according to the present invention according to claims 2 and 4 contains at least a recycled rubber, a natural rubber, a filler and a eraser which does not contain carbon black as essential components. Specifically, in the above-mentioned recycled rubber, natural rubber, heavy calcium carbonate, recycled glass powder,
White sub, process oil, titanium oxide, magnesium oxide, TMTD, precipitated sulfur, and the like, in a required amount (% by weight).

Example 2 Recycled rubber 11% by weight Natural rubber 6% by weight Recycled glass powder, heavy calcium carbonate 22% by weight White sub 52% by weight Process oil 0.5% by weight Titanium oxide 0.5% by weight Magnesium oxide 7% by weight TMTD 0.5% by weight 0.5% by weight of settled sulfur

Example 3 Natural rubber 11% by weight Recycled rubber 6% by weight Recycled glass powder, heavy calcium carbonate 22% by weight White sub 52% by weight Process oil 0.5% by weight Titanium oxide 0.5% by weight Magnesium oxide 7% by weight TMTD 0.5% by weight 0.5% by weight of settled sulfur

Next, a function retention test with respect to temperature of the rubber-based eraser of the present invention obtained in each of Examples 1 to 3 and the conventional TPE-based eraser was performed under the following test conditions. Table 1 shows the results. Here, ○ shown in the table indicates that the amount of erased dust is not different from that at normal temperature, Δ indicates that the amount of erased dust is about twice that at normal temperature, and × indicates the amount of erased dust. It shows that the generation amount is about three times that at normal temperature. Test conditions Pencil used: HB of pencil specified in JIS S 6006 Test paper: Paper A specified in JIS P 3201 Room temperature: 23 ° C Heater: Key-type heat aging tester

[0016]

[Table 1]

As is clear from Table 1, the rubber-based eraser of the present invention shows that the amount of erased dust at 60 ° C. and 80 ° C. in each of Examples 1 to 3 is less than that at room temperature. It turns out that it does not change. On the other hand, in the case of the conventional TPE-based eraser, the amount of erased dust at 60 ° C. is about twice that at normal temperature, and at 80 ° C., the amount of erased dust is about three times that at normal temperature. Accordingly, it can be seen that the rubber-based eraser of the present invention is superior in maintaining performance at high temperatures as compared with the conventional TPE-based eraser.

The rubber eraser of the present invention according to claim 3 or 4, used rubber powder containing no carbon black as an essential component, is to at least containing natural rubber, charging Hamazai, the eraser improver . Specifically, used rubber products that do not contain carbon black are processed and pulverized to a predetermined particle size by a well-known rubber powder manufacturing method, into natural rubber, heavy calcium carbonate, recycled glass powder,
White sub, process oil, titanium oxide, magnesium oxide, TMTD, precipitated sulfur, and the like, in a required amount (% by weight). The particle diameter of the used rubber powder not containing carbon black used in the present invention is 1 mm or less, preferably 0.5 mm or less, particularly preferably 0.3 mm or less. In these examples, the blending amount (% by weight) of each raw material component is basically the same as the details of each of Examples 1 to 3 described above, and thus the description thereof is omitted.

[0019]

Since the rubber-based eraser of the present invention is constituted as described above, the following effects are obtained. . When erasing handwriting such as a pencil or a mechanical pencil from the paper surface, the paper surface is not stained even if an eraser is rubbed against the paper surface. That is, since carbon black, which is a factor that stains the paper surface, is not included in the eraser, there is no risk of soiling the paper surface. In addition, there is no fear that a problem occurs in maintaining the performance at high temperatures. That is, the amount of erase dust generated at the time of erasing can be suppressed to the same state as at normal temperature.

[0020] As a used filler, the used recycled glass powder that serves as an abrasive when rubbed against the paper surface is used, so it is possible to reduce costs, as well as handwriting such as pencils and mechanical pencils from the paper surface. When erasing characters to be erased, an excellent erasing effect can be obtained with a light force without strongly rubbing the paper. That is,
An excellent erasing effect (erasing performance) can be obtained in which handwriting such as a pencil or a mechanical pencil penetrating into the fibers of the paper surface, that is, graphite, is erased from the paper surface by contacting it with the eraser.

Therefore, according to the present invention, since recycled rubber or used rubber powder containing no carbon black is used, when erasing a handwriting such as a pencil or a mechanical pencil, a carbon fiber such as a conventional TPE-based eraser is used. There is no danger that the black will transfer to the paper surface and stain the paper surface, and the handwriting can be erased reliably and neatly. Moreover, 60
To provide a rubber-based eraser that is effective for environmental protection, which is expected to have many effects such as longer life than conventional TPE-based erasers because of its excellent heat resistance against a high temperature atmosphere of ℃ to 80 ° C. Can be.

Claims (4)

[Claims] A recycled rubber containing no carbon black;
A rubber-based eraser comprising at least a filler and a eraser. 2. The rubber eraser according to claim 1, further comprising a simple substance of natural rubber, synthetic rubber emulsion rubber, polypropylene, polyethylene plastic or a composite material thereof. System eraser. 3. At least at least one of a used rubber powder not containing carbon black, a natural rubber, a synthetic rubber emulsion rubber or a polypropylene or a polyethylene plastic alone or a composite material thereof, a filler, and a eraser. A rubber-based eraser characterized by containing. 4. The rubber-based eraser according to claim 1, wherein the filler contains at least a recycled glass powder.