KR20160020382A - Artificial resin for color sharp pencil lead, and method for preparing thereof - Google Patents

Abstract

The present invention relates to a processed resin for manufacturing a color sharp pencil lead comprising 30-40 wt% of a nitro-cellulose resin, 1-10 wt% of a liquid acryl resin, 30-45 wt% of a vegetable plasticizer, and the remainder of a solvent. According to the present invention, a processed resin with little risk of explosion can be manufactured by a naturally aging method without applying heat to overcome a problem of the nitro-cellulose resin having excellent properties, but having a risk of explosion at 90°C or more. And, an environmentally-friendly vegetable plasticizer is used in manufacturing of the processed resin to manufacture a sharp pencil lead harmless to a human body to be safely used by children. When the processed resin manufactured according to the present invention is used, adhesion and curing velocity of the processed resin are easily controlled, so workability of manufacturing a color sharp lead is effectively improved.

Description

TECHNICAL FIELD [0001] The present invention relates to a processing resin for manufacturing a color pencil, and a method for manufacturing the same,

TECHNICAL FIELD The present invention relates to a processing resin in a gel state to be used for manufacturing a color pencil and a method of manufacturing the same.

In general, the sharpness is made of black graphite and can not be displayed only in black, so there is a disadvantage that it can not display various colors such as a ballpoint pen using ink.

Therefore, in order to display various colors in various colors, it was impossible to use a ballpoint pen. However, when using a ballpoint pen, the eraser can not completely erase it. Instead, it is erased using a collection tape coated with white paint, There was a flaw that made it messy and messy.

On the other hand, due to the popularization of computers and printers, the use of the pencil has shifted from the writing instrument to the check pencil era.

Therefore, as a check pencil, it is required to express various colors in a sharp sense in order to make it more conspicuous and to enhance its function. In addition, productivity and safety are guaranteed and mass productivity is required.

Such a color shampoo is basically used as a raw material pigment and includes a processing resin used as an adhesive for the pigment.

Since the processed resin is used as an adhesive for pigments, it is required to have good adhesive strength, good ductility and appropriate curing speed, so that it is excellent in processing and workability. In addition, since the processed resin affects physical properties such as abrasiveness, bending strength, elasticity, and writing feel associated with chromaticity, it is important to ensure such physical properties.

These processed resins are prepared by adding a solvent, a plasticizer and other additives to the polymer resin.

Currently processed resins include polyvinyl chloride (PVC), nitrocellulose (NC), and the like.

However, the PVC polymer has a problem in that it can not provide excellent chromaticity due to its abrasion resistance of the final manufactured color pencil due to its rigid physical properties.

In addition, NC is a soft resin, which is good in chromaticity but lacks a point of viscosity, is hard to cure, and is a non-volatile polymer material having a risk of explosion upon heat treatment at 90 ° C or more. Therefore, it is very difficult and dangerous to meet the working conditions because the NC resin has to work at a temperature of 60 ° C or less.

Korean Patent Publication No. 2014-0104797

Accordingly, the present invention is directed to solving and compensating for problems such as high explosion risk in using a processing resin used in the manufacture of a conventional color pencil, in particular, a nitrocellulose resin, and an object of the present invention is to provide an explosion The present invention provides a processed resin having good adhesion and good ductility because it can be used as an adhesive for pigments.

Another object of the present invention is to provide a process for producing the above-mentioned processed resin.

According to an embodiment of the present invention, the processed resin for manufacturing a color cap includes a nitrocellulose resin, a liquid acrylic resin, a vegetable plasticizer, and a residual amount of a solvent.

The processed resin for manufacturing a color sharp shaft according to an embodiment of the present invention is characterized by comprising 30 to 40 wt% of nitrocellulose, 1 to 10 wt% of a liquid acrylic resin, 30 to 45 wt% of a vegetable plasticizer, and a residual solvent do.

According to one embodiment of the present invention, the vegetable plasticizer is preferably mixed at a weight ratio of 30:70 to 70:30 in the two species selected from the group consisting of camphor, castor oil, and soybean oil.

According to another embodiment of the present invention, the vegetable plasticizer may be composed of 30 to 90% by weight of camphor, 1 to 35% by weight of castor oil, and 3 to 35% by weight of soybean oil.

In addition, the present invention provides a process for producing a processed resin for color shaft sharpening, comprising the steps of mixing a nitrocellulose polymer, a liquid acrylic resin, a vegetable plasticizer and a solvent, naturally aging the mixture, Dissolving the polymer; And holding the dissolved mixture to prepare a gel state.

The natural ripening is preferably performed at a temperature of 1 to 30 DEG C for 24 to 72 hours.

The dissolution is preferably performed at 5 to 20 占 폚.

The gel state may be such that the viscosity of the dissolved mixture is maintained for 70 to 80 hours.

According to the present invention, it is possible to manufacture a processed resin having no risk of explosion by a method of naturally aging the nitrocellulose resin, which has excellent physical properties and is explosive at a temperature above 90 ° C, without heating.

In addition, in the present invention, by using a plant-based plasticizer that is environmentally friendly in producing a processed resin, it is possible to manufacture a sharp horn which is harmless to human body, so that children can use it safely.

In addition, when the processed resin produced according to the present invention is used, it is possible to easily adjust the adhesive force and the curing rate of the processed resin, thereby effectively improving the workability in the production of the color shaft.

In addition, the processed resin according to the present invention has excellent abrasion resistance so that the color feeling can be easily stuck to paper, exhibits the best slippery force and is excellent in feeling, excellent in bending strength so as not to break the color sharpness well, So that it has an excellent elasticity property.

Hereinafter, the present invention will be described in more detail.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a,""an," and "the" include singular forms unless the context clearly dictates otherwise. Also, " comprise "and / or" comprising "when used herein should be interpreted as specifying the presence of stated shapes, numbers, steps, operations, elements, elements, and / And does not preclude the presence or addition of one or more other features, integers, operations, elements, elements, and / or groups.

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a processing resin used for manufacturing a color sharp shaft and a method of manufacturing the same.

In the present invention, in order to solve the problem of the sharp-point manufacturing process which is difficult due to the NC resin having a high explosion risk in the conventional manufacturing process, a resin that is preliminarily processed so as to avoid explosion danger is manufactured and used for manufacturing the sharp-point.

Therefore, the term "processed resin" used throughout the specification of the present invention means a resin prepared by adding other components to the NC resin.

To this end, the processed resin according to the present invention is characterized by containing a nitrocellulose resin, a liquid acrylic resin, a vegetable plasticizer, and a residual amount of a solvent.

Specifically, it may contain 30 to 40% by weight of nitrocellulose, 1 to 10% by weight of a liquid acrylic resin, 30 to 45% by weight of a vegetable plasticizer, and a residual solvent.

The nitrocellulose resin contained in the processed resin is excellent in abrasion resistance, exhibits good color representation of the sharpness, and has excellent bending strength. However, there is a problem in that the adhesive strength to the pigment included in the production of the sharp point is inferior because of the lack of the softness (softness). In addition, since the curing rate is too high, the workability is weak.

Accordingly, the present invention includes a liquid acrylate (LAC) to compensate for the above disadvantages while maintaining the abrasion and bending strength required in the drawing. The 'liquid acrylic resin' according to the present invention means a resin in which acrylic resin is melted to form a liquid phase or mixed with water to form a liquid phase.

The liquid acrylic resin is excellent in adhesion (softness) because of its good viscosity (softness), good in slipperiness and excellent in feeling of feeling, and excellent in tension (elasticity). Also, it can be liquefied because it can apply heat, and it can be dried at high temperature because there is no danger of explosion, and it is liquid, which can delay the hardening of the processing resin.

Therefore, by mixing the nitrocellulose resin and the liquid acrylic resin, it is possible to manufacture a processed resin having excellent color strength, softness and viscosity while maintaining the flexural strength and elasticity and improving the workability.

In the present invention, the nitrocellulose resin is preferably contained in an amount of 30 to 40% by weight and the liquid acrylic resin may be contained in an amount of 1 to 10% by weight in order to have a synergistic effect due to the mixing of the two resins.

When the content of the nitrocellulose resin is less than 30% by weight, there is a problem in that the chromaticity is insufficient and the flexural strength is lowered. When the content is more than 40% by weight, the flexural strength is improved but it is difficult to control the curing rate. The type of the nitrocellulose resin is not particularly limited and may be any of those used for the processing resin included in the manufacture of the cap.

When the content of the liquid acrylic resin is less than 1% by weight, the addition effect is not obtained. When the content exceeds 10% by weight, the elasticity is improved but the wear resistance is lowered.

The processed resin according to the present invention is prepared by previously adding a plasticizer which was added separately at the time of manufacturing the conventional cap. The plasticizer used herein may be preferably a vegetable plasticizer derived from a natural material.

The vegetable plasticizer according to an embodiment of the present invention is preferably a mixture of two or more selected from the group consisting of camphor, castor oil, and soybean oil.

Concretely, the two species selected from the group consisting of camphor, castor oil and soybean oil can be mixed at a weight ratio of 30:70 to 70:30. If the mixing ratio of the above two types of plasticizers to be mixed is out of the above range, there is a problem that ductility, workability and explosion risk reduction rate are lowered, which is not preferable.

In the present invention, two or more selected from the three plasticizers can be mixed. However, since the castor oil and the soybean oil have similar characteristics, it is more preferable to mix any one selected from castor oil and soybean oil with the camphor desirable.

According to another embodiment of the present invention, the vegetable plasticizer may be composed of 30 to 90% by weight of camphor, 1 to 35% by weight of castor oil, and 3 to 35% by weight of soybean oil.

If the content of the camphor is less than 30% by weight, the content of other constituents increases, which results in a slippery and poor ductility, deteriorating the adhesive force with the polymer resin and failing to effectively control the explosion risk. Which is not preferable.

Also, when the castor oil and soybean oil are less than the above range, the content of camphor becomes too high to increase the hardening speed, resulting in a decrease in workability. When the content exceeds the above range, the viscosity is lowered, which is undesirable.

The working resin according to the present invention is prepared by adding a solvent to the nitrocellulose resin, the liquid acrylic resin and the vegetable plasticizer. The above three compositions may be added in a predetermined amount, and a remaining amount of the solvent may be added to adjust the amount to 100 wt%. The solvent is not particularly limited, but methyl ethyl ketone is preferably used.

Hereinafter, a method for producing a processed resin for forming a color cap according to the present invention will be described. The processed resin according to the present invention is characterized in that there is no risk of explosion.

Concretely, it is preferable to mix the nitrocellulose resin, the liquid acrylic resin, the vegetable plasticizer and the solvent as the raw materials, naturally aging the mixture at a temperature of 1 to 30 ° C for 24 to 72 hours, Dissolving the nitrocellulose polymer at 5 to 20 ° C, and maintaining the viscosity of the dissolved mixture for 70 to 80 hours to prepare a gel.

First, the first step is to mix each raw material contained in the working resin according to the above-mentioned predetermined contents. The mixing method is not particularly limited and can be carried out by a conventional method.

It is very dangerous to heat the mixed raw material because the nitrocellulose resin among the mixed raw materials has a property of exploding at 90 ° C or higher. Therefore, in the present invention, the mixture is subjected to natural aging at 1 to 30 ° C at room temperature for 24 to 72 hours. Since it naturally ages at the above-mentioned temperature, it has the effect of eliminating the danger of explosion of the nitrocellulose resin. It is preferable that the aging condition is carried out for a sufficient time in the vicinity of room temperature, but it is preferable to appropriately adjust the aging time because it falls into the invention when it exceeds 72 hours. In addition, if the natural aging temperature is too low to be less than 1 占 폚, there is a problem that it needs to be re-thawed, and it is preferable to minimize the risk of explosion by not exceeding 30 占 폚.

The naturally aged mixture is subjected to a step of dissolving the nitrocellulose polymer at a temperature of 5 to 20 ° C. At this temperature, the nitrocellulose polymer is sufficiently dissolved in methyl ethyl ketone as a solvent. The dissolution time is preferably 10 to 30 hours.

Further, the dissolved mixture is subjected to a step of maintaining the viscosity thereof for 70 to 80 hours to prepare a gel state. In the present invention, it is preferable to maintain the viscosity of the melted mixture for producing a processed resin in a gel state so that sufficient blending with the processed pigment to be added at the time of manufacturing the next sharp point can be ensured without explosion risk. Therefore, the term 'gel state' according to the present invention includes a state of flowability sufficient to sufficiently disperse the powdery processed pigment, and the viscosity thereof is not particularly limited.

The processed resin in the gel state can be used after being sealed and refrigerated, and taken out whenever necessary.

Hereinafter, preferred embodiments of the present invention will be described in detail. The following examples are intended to illustrate the present invention, but the scope of the present invention should not be construed as being limited by these examples. In the following examples, specific compounds are exemplified. However, it is apparent to those skilled in the art that equivalents of these compounds can be used in similar amounts.

Example: Processed resin production

According to the composition shown in the following Table 1, nitrocellulose resin, liquid acrylic resin, vegetable plasticizer, and methyl ethyl ketone solvent were mixed. The mixed material was put into a pot and subjected to natural aging at 15 DEG C for 24 hours. The naturally aged mixture was kept at 10 DEG C for 24 hours to dissolve the nitrocellulose resin. Then, while maintaining the viscosity at the time of dissolution, the resin was stored for 72 hours to obtain a processed resin in a gel state. The obtained processed resin was sealed and stored in a refrigerator.

Content (% by weight) Example Comparative Example One 2 3 One 2 3 Nitrocellulose 30 36.5 40 20.5 45 60 Liquid acrylic resin 5.5 8.5 3 15 5 - Vegetable
Plasticizer Campa 12.9 26.4 23.1 32 10 20 ^* Castor oil 20.1 1.2 6.6 8 10 Soybean oil 30 2.4 3.3 - 10 Solvent (methyl ethyl ketone) 21.5 25.5 24 24.5 20 20 * Is prepared by using DBP which is a conventional chemical plasticizer and heating under the conventional conditions

Experimental Example: Measurement of Physical Properties

The physical properties of the processed resin prepared according to the examples and preparation examples were measured as follows, and the results are shown in Table 2 below.

1) Adhesion

The degree of adhesion at the time of mixing the above-prepared processed resin into the pigment was evaluated under the weight, and the results are shown in Table 2 below. The case where the processed resin and the pigment were well adhered and maintained for 10 minutes or more, and the case where the resin was separated by more than 50% at the elapse of 10 minutes and completely separated at the elapse of 10 minutes was evaluated as below.

2) Workability

The degree of workability at the time of working with the above-prepared processed resin was evaluated and the relative value was evaluated based on the workability of commercially available synthetic resin as 100. [

3) Possibility of Explosion

And whether or not it exploded during the production of the processed resin was measured.

4) Measurement of bending strength

The bending strength refers to the bearing force (resistance to external force when bending or bending) until breaking, and there are no international and domestic standards for current shims. In the case of black shins, international standards (Japan JS) are 10,000 ~ 15,000, and the domestic standard (KS) is 8,000 ~ 10,000.

In the present invention, the flexural strength was measured according to the following equation (1) using a standardized flexural strength meter. In the present invention, a color pencil manufactured by using the above-mentioned processed resin was used for measuring the bending strength.

(1)

Where F is the bending strength, P is the load, L is the inter-beam distance, and D is the diameter of the core.

sample Adhesion Workability Explosion potential Flexural strength Example 1 Prize Prize X 100 Example 2 Prize Prize X 90 Example 3 Prize Prize X 95 Comparative Example 1 medium Ha X 60 Comparative Example 2 Ha Ha X 79 Comparative Example 3 Prize Ha ○ 60

Referring to the results of Table 2 above, it can be seen that the processed resin prepared by the natural aging process by adding the liquid acrylic resin to the nitrocellulose resin as described in the present invention and using the vegetable plasticizer has the excellent effect of adhesion, workability and bending strength Respectively. In addition, the possibility of explosion as in Comparative Example 3 when a processed resin was manufactured using nitrocellulose resin using a conventional chemical plasticizer could be completely solved through a natural aging process.

However, as in Comparative Example 1, when the content of the nitrocellulose resin was too large or the content of the liquid acrylic resin was too large, it was confirmed that the control of the curing rate was difficult and the workability was very poor.

Claims (3)

A nitrocellulose resin, a liquid acrylic resin, a vegetable plasticizer, and a residual amount of a solvent.
The method according to claim 1,
Wherein the processed resin comprises 30 to 40% by weight of a nitrocellulose resin, 1 to 10% by weight of a liquid acrylic resin, 30 to 45% by weight of a vegetable plasticizer, and a residual amount of a solvent.
The method according to claim 1,
Wherein the vegetable plasticizer is a mixture of two kinds selected from the group consisting of camphor, castor oil, and soybean oil at a weight ratio of 30:70 to 70:30.