JPS60161199A - Eraser and manufacture thereof - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel erasing eraser and a method for producing the same, and more specifically, it is possible to stably contain a large amount of erasing liquid in a base resin, and therefore has excellent erasing power. Moreover, the present invention relates to an eraser that does not cause bleeding and a manufacturing method thereof.

Various types of erasers for erasing handwriting using oil-based or water-soluble ink have been proposed so far.

Among them, solid erasers, which are made by kneading erasing liquid (binder resin in ink, solvent that can dissolve dye) into eraser base resin such as vinyl chloride resin, are easy to handle and easy to erase. It has the advantage of being easy. However, when the erasing liquid is simply kneaded into the eraser base material and molded, severe bleeding occurs even when only 2 to 5 phr is added, and after the bleeding, the erasing ability is significantly reduced. on the other hand,
When using an erasing fluid that is highly compatible with vinyl chloride resin, etc., this type of erasing fluid also functions as a plasticizer, resulting in a weakened effectiveness as an erasing fluid. In addition, regardless of the compatibility with the base resin, products made by adding erasing liquid to profiteering resins within a range that does not cause bleeding generally have low erasing ability and cannot satisfy practicality. .

On the other hand, Japanese Patent Publication No. 58-52520 proposes an eraser in which eraser-containing microcapsules whose film material is an aggregate of silica fine particles are dispersed in a base resin. In general, press molding is superior to extrusion, injection molding, and other methods for manufacturing plastic erasers; however, in such microcapsule-containing erasers, silica, which is a membrane material, is a paste of vinyl chloride resin. The viscosity becomes very high, causing problems in press processing, etc.
There is a problem in that the amount of microcapsules added is limited, and therefore the erasing ability is limited. Furthermore, the silica film does not have sufficient strength, and there is a possibility that the eraser and plasticizer may not only mix, but also seep into the eraser. Further, according to additional tests conducted by the present inventors, it is not possible to easily form microcapsules even if the operations described in the publication are carried out, and a fairly advanced technique is required.

Furthermore, Japanese Patent Application Laid-open No. 72121/1983 proposes an eraser in which a microscopic inorganic hollow body that occludes an eraser is arranged in an eraser. However, balloons such as glass balloons are easily broken when kneaded with rolls, and it is difficult to mold them so as not to break by extrusion or injection molding, and therefore there are restrictions on the formulation. Furthermore, erasers containing balloons have the problem of being slippery when erasing characters and difficult to break during erasing operations. Also, it takes 120kg/C to absorb the erasing liquid.
It is necessary to pressurize to ++1 or more, which inevitably increases the cost of the equipment.

In view of the above-mentioned circumstances, the inventors of the present invention have conducted intensive M research in order to solve these problems, and as a result, they have found that by making the eraser exist in the base resin as a gel-like or wax-like fine powder, the intended purpose can be achieved. The present invention has been completed based on the discovery that the following can be achieved.

That is, the first aspect of the present invention is an eraser made by dispersing in a base resin a gel-like or wax-like fine powder made of a binder resin for water-based or oil-based ink and a solvent capable of melting the dye. The second aspect of the invention is to add a gelling agent to the erasing liquid to form a gel or wax form, which is then finely ground in a dispersion medium.
The contents include a method for manufacturing an eraser, which is characterized by adding and mixing a dispersant, then removing the dispersion medium, dispersing a gel-like or wax-like eraser fine powder into a base resin, and heat-molding it. Further, the third aspect of the present invention is to add a gelling agent to the eraser to make it gel-like or wax-like. is finely pulverized in a dispersion medium to form a suspension of gel-like or wax-like eraser fine powder, and then a water-soluble polymer is added to the suspension with high speed stirring. Microcapsules are separated from the dispersion medium, and the microcapsules are separated from the dispersion medium, and the microcapsules are separated from the dispersion medium, and the microcapsules have a core material of the gel-like or waxy eraser powder obtained by phase separation or insolubilization, and the water-soluble polymer is the glandular material. The subject matter is a method for producing an eraser, which is characterized by dispersing it in a base resin and then heat molding it.

The erasing liquid used in the present invention is one that has the ability to dissolve the binder resin of the ink, and becomes gel-like or wax-like at a temperature of room temperature or higher, preferably 50°C or higher, due to the kelizing agent. Example let: d51J ethylene glycol, polypropylene glycol, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol, diethylene glycol 7-methyl ether, diethylene glycol monoethyl ether acetate, I.
Liebulene glycol, polycopyrene gellicol, Mexico: coolant desolamine, polymexyethylene alcoholic amine, alkylamine, dodecylamine, monoethanolamine, jetanolamine, triethanolamine, diethylethanolamine, ethyl jetanol Included are amines, ethylene carbonate, propylene carbonate, ethyl lactate, and the like.

Gelling agents used in the present invention include dihensylidene sorbitol, trihensylidene sorbitol, etc., and other resins that are mixed with the eraser and hold the eraser in a gel or waxy state, such as polyvinyl alcohol, Acetylcellulose, acedelbutylcellulose, nitromono1nolose, edylcellulose,
These include polymethyl methacrylate, I5 ribinyl butyral, and the like.

The content of the gelling agent is preferably 0.2 to 30% by weight, more preferably 5 to 30% by weight of the eraser.

If it is less than the above range, it will not form a gel or waxy state, while if it is more than the above range, there will be problems such as the need to increase the heating temperature of the pot to dissolve the gelling agent and increase the stirring time. Sign.

In the eraser of the present invention, for example, a gelling agent is added to the eraser and melted by heating to form a gel or wax shape. This is coarsely pulverized, then finely pulverized using a homomixer or the like in a dispersion medium that has poor compatibility with the eraser, and after a dispersant is added and mixed, the dispersion medium is removed.

Suitable dispersants include powdered erasing base materials such as calcium carbonate, silica, and polyvinyl chloride, and mixtures thereof.
Among these, mixtures of calcium carbonate and silica are preferred.

By using hydrophobic silica as the silica, it is advantageous to repel moisture and thus prevent the eraser from absorbing moisture. The dispersant is a gel-like or waxy substance1
The range of 50 to 300 parts by weight per 00 parts by weight is 117
I am a connoisseur.

As a dispersion medium, a solvent with poor compatibility with the eraser is used, such as n-hexyne, n-heptano, n-octane, iso-
Hydrocarbon solvents such as octane are preferred, with n-hexitine being particularly preferred.

The eraser gel-like or waxy fine powder obtained in this way is separated from the dispersion medium, mixed with the eraser profit resin, and an eraser can be obtained by extrusion, injection, press molding, etc.The base resin is a resin. , a plasticizer, a filler, a stabilizer, etc., and an example of their formulation is: 70 to 180 parts by weight of a plasticizer, 1 to 3 parts by weight of a stabilizer, and 0 to 120 parts by weight of a filler per 100 parts by weight of vinyl chloride paste. part is preferred.

In the present invention, since the erasing liquid exists in a gel or wax form, it is stably dispersed and held in the base resin. However, in the range of 2 to 10 pk+r, the eraser is completely dry (it does not cause bleed, but just in case, for the purpose of preventing bleed, use a material that absorbs the eraser at room temperature, such as silica or organic hetonite). It is desirable to add a substance having the following properties, or to add an eraser such as propylene carbonate, which has good compatibility with polyvinyl chloride, in a liquid state or in the form of a gel-like or wax-like fine powder.

In addition, the gel-like or wax-like fine powder of the eraser contains some liquid eraser that has not gelled, and if there is a large amount of liquid eraser, it may cause bleeding, but if the gel-like or wax-like fine powder is washed with water, By washing away the eraser that remains in liquid form,
Bleed can be effectively prevented.

In the present invention, by microcapsulating the gel-like or liquid-erasing solution with a water-soluble polymer and dispersing it in the base resin, the volatilization of the erasing solution over time is more effectively suppressed, and the gel-erasing solution is gelatinized during heat molding. and waxy eraser.
χ protection, and also prevents the eraser from seeping into the base resin.

The water-soluble polymers include sodium alginate, sodium polyacrylate, polyvinylpyrrolidone, PV
A etc. are preferred. To carry out microencapsulation using sodium alginate, for example, the gel-like or wax-like eraser is finely pulverized in a dispersion medium to form a suspension of gel-like or wax-like eraser fine powder, and then After adding sodium alginate water/8/& under stirring,
A Ca CI 2 aqueous solution is gradually added to obtain microcapsules having water-insoluble calcium alginate as a membrane material and gel-like or wax-like eraser fine powder as a core material.

The concentration of the sodium alginate aqueous solution is preferably 0.54%, and 10 to 30% is added to the quench/& mixture.

The CaCl2 aqueous solution preferably has a concentration of about 5 to 30%. The dispersion medium is preferably a solvent that has low compatibility with the erasing liquid and is incompatible with the membrane material and water, such as hydrocarbon solvents such as RL-Hexane.

On the other hand, when using sodium polyacrylate as a membrane material, for example, add 0.1 to 3% water/8 solution of sodium polyacrylate to a suspension of gel-like or wax-like powder in a high-speed stirring state. 10~ for liquid gel or waxy fine powder
After adding 30%, a water-compatible solvent such as acetone is added to phase separate polyacrylic acid and notorium.
Microcapsules are obtained in which the core material is gel-like or waxy eraser powder and the membrane material is sodium polyacrylate.

The obtained microcapsules are filtered, dried, dispersed in base material 4, and heated and molded.

In the case of microcapsulation, a dispersant is not necessarily required, but by adding it in the process before separating it from the dispersion medium, it can not only prevent the membrane materials from adhering to each other and form clumps, but can also be used as an eraser in certain devices. Since the amount of gelling agent can be increased, there is an advantage that productivity can be improved.

According to the present invention, (1) the erasing liquid is dispersed in the base resin in the form of a gel or wax, so it retains its gel or wax shape even when subjected to shearing; It temporarily turns into droplets in the resin, but returns to its original gel-like or wax-like form when it cools down (by selecting the erasing liquid and gelling agent, it is possible to create a product that does not liquefy even at the molding temperature).
, ■ Compared to the case where it is dispersed and contained in liquid form, volatilization over time is not only small, but there is virtually no seepage into the 7A'FA resin, ■ Content of erasing liquid in the base resin. Because you can make the image larger, you can improve your erasing ability.■
The microcapsules of the present invention are chemically stable and stable against heat during molding, and have many advantages such as being more completely prevented from volatilizing over time and seeping into the base resin.

The present invention will be described below with reference to Examples, but the present invention is not limited thereto in any way.

Example 1 34 g of ethylene glycol and 6 g of dihenzylidene sorbitol ([Gelol DJ, manufactured by Shin Nippon Rika) were mixed at a rotation speed of 2.
A gel-like material was obtained by heating and mixing at about 180°C while stirring at 000 to 250 lrpm.

The gel material was then coarsely ground and finely ground to a particle size of 0.1 mm in n-hexane using a homomixer. 80 g of calcium carbonate was added to this and mixed with a mixer. After filtration, a waxy fine powder of ethylene glycol and calcium carbonate was obtained through vacuum drying.

The obtained waxy fine powder was blended with a base resin as shown below, and after degassing, it was poured into a press mold and press molded (approximately 125 mm
°C for about 15 minutes) to obtain a product, and the erasure rate was measured. For comparison, we also measured the erasure rate of commercially available erasers, and the results are shown in Table 1.
10j: rPSL -378 J=6:4)
100 (g) Diisononyl phthalate (plasticizer) 11
0 Dihebyl phthalate (plasticizer) 5 Calcium carbonate (dispersant) 20 Waxy fine powder 120 rFG-5008 (stabilizer, manufactured by Nitto Kasei) 1rS
C-36J (stabilizer, made by Adeka Argus) 0, 5 Silica (rR972j, made by Nippon Aerosil) 3 Example 2 38 g of diethylene glycol 7-methyl ether and polyvinyl butyral ([Nisrex BX-H1 Sekisui Kai!
Stir 1.2g of polyvinyl butyral
After iIlj, 4 g of dihenzylidene sorbitol ([-gelol D, manufactured by Shin Nippon Rika) was added and boiled at 160°C.
<56 solved. Also, after cooling this to 140"C, 0℃
Stir (3000 rpm) in n-hexane cooled to
The mixture was gradually added to form a waxy powder. A diethylene glycol monomethyl ether waxy powder in n-hexane was pulverized in a homomixer to a particle size of about 0.1 mm. 40 g of polyvinyl chloride (rPSH-10J, manufactured by Line On Kagaku Co., Ltd.) was added to this and mixed in a mixer, filtered and vacuum dried to form a mixture of waxy fine powder of diethylene glycol 7-methyl ether and polyvinyl chloride (η).

Propylene carbonate 1-4.5g & Konohengylidene Sorbitol (Gel All DJ, New Japan Rika) 05g
7Jl at 160°C], cooled to 140°C, and stirred in n-hexane cooled to 0°C for 1't! (
(3,000 rpm) Cina M, D, L, and C were further finely pulverized using a homomixer (6,000 rpm) to give particles of about 0.1 mm. Calcium carbonate 15
g and mixed with a mixer to obtain a mixture of waxy fine powder of propylene carbonate and calcium carbonate.

The obtained two kinds of waxy powders were blended with a base resin as shown below, and after defoaming, they were cast into a press mold to obtain a press-molded product (approximately 125°C, approximately 15 minutes). . Table 1 shows the erasure rate of the obtained products.

Polyvinyl chloride base (+'l'SL-378)
, made by Line On Kagaku) 60 (g) Dibdelphthalate (plasticizer) 11゜Dibdelphthalate (plasticizer)] 0 Calcium carbonate (filler) 5 Waxy fine powder of diethylene glycol monomedyl ether + polyvinyl chloride mixture 8゜Propylene carbonate powder] Tube-shaped fine powder + calcium carbonate mixture 20 r57LJ (stabilizer, manufactured by Dainippon Ink) 1.5 Example 3 Polyethylene glycol (r#200'', Japan m>IJ
After adding 10 tr of Nhenzilidene sorbitol ("Gel All D", manufactured by Shin Nippon Rika) to 90 g (manufactured by I) and dissolving it by heating (160°C), it was cooled to room temperature to obtain a gel-like substance, which was cut into a cutter. It was cut into pieces with a blade of 3 to 5 mm. Next, this was added to n-hexane and pulverized using a homomixer.

Next, 1.5% sodium alginate water/8m20g
was stirred (500 rpm
)i, while adding 2o%C;+C12rk'
The TFI solution was gradually added with stirring (2000 rpm). Filtration and drying were performed to obtain microcapsules whose core material was polyethylene glycol and whose membrane material was calcium alginate. A microscopic photograph of the microcapsules is shown in FIG.

The obtained microcapsules were blended with a base resin as described below, and after degassing, they were cast into a press mold and press-molded (approximately 12
A shredded product was obtained (about 15 minutes).

Table 1 shows the erasure rate of the obtained products.

Polyvinyl chloride base (rpso-1o J,
Line On Kagaku) 10100 (diisononyl phthalate (plasticizer) 100 dihebyl phthalate (plasticizer) 1° calcium carbonate (filler)
80 Microcapsule 50 r57LJ (stabilizer, manufactured by Dainippon Ink)] rSC-3
6J (Stabilizer, manufactured by Adeka Argus) 0, 5 Table 1 (Request: %) (Sho) Erasing rate is I Racing Film (SALIRA)
ICO, I, Tr), , S 200.50μ) to 50
X 5 (l rn Cut out m, and use a line drawing pen (special black ink) to make sure the lines do not overlap.
Use a test paper with a straight line of 6; 1 layer 6
The test was conducted in accordance with JIS S-6050 except that the weight was 0.00 g, and the number of times of 7 erasure was 5, 10, and 20 times (all round trips).

Large, ** Eraser is contained in the eraser and material in liquid form to the extent that it does not cause bleed, and consists of the following formulation.

l-Sample 1'' [Sample 2'' Polyvinyl chloride base ['5l(-10J 100 (g) 1.00 (g
) 1] ○P 70 90 1) HP 10 20 Calcium carbonate 100 100 rFG-500 -F was used, but this has good compatibility with PVC and functions as a plasticizer, weakening its action as an eraser and making it impractical.On the other hand, in (-sample 21), diethylene glycol mono Perhaps medyl ether was used as the erasing liquid, but a sufficient erasing effect could not be obtained.

[Brief explanation of the drawing]

FIG. 1 is a microscopic photograph of the microcapsules produced in Example 3. Procedure Neho Seiichi = (spontaneous) ■, Indication of the case 1982 Patent Application No. 16811 2, Erasing the name of the invention and its manufacturing method 3, Person making the amendment Relationship with the case: Patent applicant address Osaka City 3-5-25, Uchishiro-cho, Bejima-ku Name: Seed Rubber Industries Co., Ltd. Representative: Hiroshi Tamai - 4, Agent address: 3-2-4-5, Nishitenma, Kita-ku, Osaka, subject to amendment: r3.8gJ Correct it to "38g". What is the procedure? +V4f Formal writing (method) % formula % 2. Name of the invention and its manufacturing method 3 Relationship with the case of the person making the amendment = Patent applicant address 3-5-25 Uchishiromachi, Bejima-ku, Osaka City Name Sea 1 Rubber Industry Co., Ltd. Representative Director Hiroshi Tamai =・4, Agent Address 3-2-4-5 Nishitenma, Kita-ku, Osaka City, ? April 4, 1959 (Date of dispatch: April 2, 1959)
4) Correct the photo.

Claims (1)

[Claims] (1) Gel-like or wax-like fine powder made of a binder resin for water-based or oil-based ink and a solvent capable of dissolving the dye (hereinafter referred to as erasing liquid) by /8 is dispersed in the base resin. Naruji eraser. 2. The eraser according to claim 11fj, wherein the gel-like or wax-like fine powder is obtained by phase-separating or insolubilizing a water/8-based polymer and encapsulating the resultant microphone. 3. The eraser according to claim 2, wherein the water-soluble polymer is at least one selected from sodium alginate, sodium polyacrylate, polyvinylpyrrolidone, and PVA. 4. Add a gelling agent to the erasing liquid to make a gel or wax, pulverize it in a dispersion medium, add and mix the dispersant, and then remove the dispersion medium to obtain a gel or wax. A method for manufacturing an eraser, characterized by dispersing Li&powder of the eraser into a resin material and molding it under heat. 5. The manufacturing method according to claim 4, wherein the dispersion medium is a solvent with poor compatibility with the eraser. 6. The manufacturing method according to claim 4 or 5, wherein the dispersion medium is n-hexane or n-hebutane. 7. The manufacturing method according to claim 4, wherein the dispersant is selected from powdered erasing base materials such as calcium carbonate, silica, polyvinyl chloride, and mixtures thereof. 8. Add a gelling agent to the eraser to make it gel-like or wax-like, and pulverize it in a dispersion medium to make gel-like or wax-like eraser fine powder. ”, a fine powder of a gel-like or wax-like eraser obtained by adding a water-soluble polymer to the suspension, which is stirred at high speed, and then phase-separating or insolubilizing the water-soluble polymer, is used as a core. A method for producing an eraser, characterized in that microcapsules having a membrane material of a water-soluble polymer are separated from the dispersion medium, and further the microcapsules are dispersed in a base resin and heated and molded.90 Dispersion medium. The manufacturing method according to claim 8, wherein the dispersion medium is a solvent that has low compatibility with the eraser and is incompatible with the membrane material and water. 10. The method of claim 8, wherein the dispersion medium is n-hexane. 8
The manufacturing method according to item 9 or item 9. 11. The manufacturing method according to claim 8, wherein the dispersant is selected from powdered powders such as calcium carbonate, silica, polyvinyl chloride, and mixtures thereof. 12 The water-soluble polymer is 1-lium alginate, storium polyacrylate, polyvinylpyrrolidone, PVA
9. The manufacturing method according to claim 8, wherein at least one type is selected from the following.