JPS5823423B2 - Soft writing composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a soft writing composition, more specifically a crayon,
This invention relates to relatively soft writing compositions such as pastels and colored pencil leads.

Various types of soft writing compositions have been proposed in the past, such as those in which a reaction product of an epoxidized diene polymer and a carboxylic acid or dicarboxylic acid is mixed with a wax oil, an extender, or a pigment ( JP-A No. 51-2527) Polymers of esters such as acrylic acid and methacrylic acid with pigments and extenders added (JP-A No. 51-9
No. 0622), ionomer resin made by ionically crosslinking a copolymer of ethylene and methacrylic acid with sodium or zinc, and oxystearyl alcohol (
JP-A No. 52-80924), a wax composition prepared by heating and mixing polyethylene and a polyhydric alcohol or polyhydric alcohol ester that is compatible with polyethylene and is solid at room temperature, and a dye added to it (specially Publication No. 51-6582) and those containing olefin polymers, ethylene-vinyl acetate copolymers, and high-boiling esters (Japanese Patent Publication No. 51-6582)
1-25183) etc. have been proposed.

Conventional soft writing compositions have good coloring properties, and those that can be coated in layers tend to stain the paper surface and the writer's hands after writing.
In addition, it is difficult to erase, and conversely, if you try to erase easily and reduce the dirt on the paper surface and hands, the soft composition for writing that can be obtained is easy to break, has poor coloring properties, and has a poor writing quality. However, we have not been able to find anything that satisfies these contradictory demands at the same time.

The present invention provides a soft writing composition that does not stain the paper surface or the user's hands, is easy to erase, has a good writing feel, has good coloring properties, can be overcoated, is resistant to folding, and is easy to scrape. It is.

The present invention comprises a film layer of a composition containing polyethylene, a polymer of an olefin compound other than ethylene, petroleum wax, and synthetic rubber, and a layer mainly containing one or more of natural resins, vegetable waxes, and fatty acid salts that are solid at room temperature. This is based on the knowledge that the above-mentioned characteristics can be achieved by mixing the two components or by dispersing the latter component in the former.

The gist of the present invention is a soft writing composition comprising polyethylene, a polymer of an olefin compound below ethylene, petroleum wax, and synthetic rubber containing at least one of a natural resin, a vegetable wax, and a fatty acid salt that is solid at room temperature. .

Furthermore, the soft writing composition of the present invention has polyethylene 10 to
40% by weight, 5-30% by weight of polymers of olefin compounds other than ethylene, 10-40% by weight of petroleum wax,
Even better properties can be obtained by including extenders and pigments in a mixed composition consisting of 3 to 10% by weight of synthetic rubber, natural resin, vegetable wax, and at least one of fatty acid salts that are solid at room temperature. .

The polyethylene used has a molecular weight of 10,000 to 40,000, although it is determined depending on the types of other raw materials to be blended with it.

As the polymer of an olefin compound other than ethylene, a polymer of an olefin compound having 3 to 12 carbon atoms may be used alone or a mixture thereof.

As the synthetic rubber, Buna S, Buna N1 neobrene, butyl rubber, polysulfide rubber, incyanato rubber, fluororubber, and silicon rubber are used.

Examples of natural resins include copal, dammar, rosin, palsams, shellac, etc.

Fatty acid salts that are solid at room temperature include calcium, sodium or potassium salts of fatty acids such as palmitic acid and stearic acid.

In the soft writing composition of the present invention, not only the respective composition components complement each other's properties, but also the coexistence of these components makes it possible to simultaneously enjoy mutually contradictory properties.

If polyethylene, polymers of olefin compounds other than ethylene, waxes, and synthetic rubbers deviate from the above-mentioned ranges, the mixed composition of these components may differ from the remaining component pigments, extender natural resins, oils and fats, fatty acid salts, etc. Because a layered composition is not formed microscopically or the latter component is not dispersed in the former, it becomes more smudged, more prone to folding, and cannot be recoated.

In addition, at least one of natural resins, vegetable waxes, and fatty acid salts that are solid at room temperature are added to polyethylene, polymers of olefin compounds other than ethylene, and synthetic rubber that are mutually dissolved and integrated into a flat surface. Since the shaped or lattice shaped film covers the soft writing composition of the present invention,
Not only does it not stain like conventional products just by touching it with your hands, but it also does not stain the clothing surface even if you actively rub it on the surface of the clothing. Since they are scattered on the film surface of the aforementioned polyethylene, polyolefin, synthetic rubber, etc., they can be easily written on paper or both paper surfaces with normal writing pressure, and can leave handwriting on the screen or paper surface.

Moreover, since this handwriting is formed by pigments in and on the surface of the film, which is mainly made of polyethylene or ethylene synthetic rubber, the handwriting can be erased without blurring with a small number of rubs with an ordinary rubber eraser.

Furthermore, the strength of the light writing composition of the present invention can be increased by the comprehensive formulation, especially the melt products of polyethylene, polymers of polyolefin compounds other than ethylene, synthetic rubbers, and waxes.

Specifically, even if a Freon molded body with a diameter of 8 mm and a length of 55 mm is dropped from a height of 3 meters onto a concrete surface, it will not be damaged at all, and even if it is heated to 60°C to 70°C, it will hardly soften. I can't do it.

Next, the embodiments of the present invention will be described with reference to Examples, but the present invention is not limited thereto.

Note that % in the text indicates weight % unless otherwise specified.

Example 1 To mix, first put petroleum wax in a heating mixer and
℃, and then about half of the predetermined blended amounts of polypropylene and polyethylene were gradually charged thereinto to uniformly melt them.

After melting, synthetic rubber, wax, sodium stearate, and finally polyethylene and polypropylene were added, and after uniformly melting, talc and pigment were added.

After the composition was made uniform, it was molded into a plate shape, and the molded product was crushed and injection molded to have a diameter of 8 mm and a length of 5501 mm and 71 L.

The properties of this molded article, such as breakability, erasability, and softening properties, were as shown in Table 1 below.

Breakability: When a sample is dropped parallel to a concrete surface, the height to the concrete surface at which the sample begins to break.

Erasability: The number of times an eraser is rubbed in the same direction until it is erased.

Softening property: Place the sample in a constant temperature bath, fix one end by 10 mm and leave the other end free, keep at a predetermined temperature for 1 hour, and show the deviation of the free end of the sample after 1 hour before and after the start of the test.

The amount of adhesion is the amount of adhesion when applied once evenly in both the vertical and horizontal directions on drawing paper No. AI with a load of 350 g.

As comparative examples, two types of commercially available products were selected and tested according to Example 1, and the results obtained are shown in Table 1.

Example 2 A molded article of a soft writing composition having the following formulation and the same shape as in Example 1 was produced according to Example 1, and its characteristics were tested according to Example 1.

The amount of adhesion is 1180μ? , erasability is 3 times and softening is 70℃
However, no deviation was observed, and it did not break even after falling from a height of 3.5 m.

Example 3 A molded article of a soft writing composition having the following formulation and the same shape as in Example 1 was produced according to Example 1, and its characteristics were tested according to Example 1.

The resulting soft writing composition had a coating weight of 1160 μg, erasability was 3 times, no softening was observed even at 70° C., and it did not break even when dropped from a height of 3.5 m.

Example 4 A molded article of a soft writing composition having the following formulation and the same shape as in Example 1 was produced according to Example 1, and its characteristics were tested according to Example 1.

Wax (vegetable wax) 5 parts lard
5 parts calcium palmitate 5 parts talc
5 parts pigment
The 6 parts of the obtained soft writing composition had a coating weight of 1170 μg, erasability was 3 times, no softening was observed even at 70°C, and it did not break even when dropped from a height of 3.5 m. Ta.

Claims (1)

[Claims] 1 10 to 40% by weight of polyethylene, 5 to 30% by weight of polymers of olefin compounds other than ethylene, 10 to 40% by weight of petroleum wax, 3 to 10% by weight of synthetic rubber, and the remainder is at least a natural resin, a plant that is solid at room temperature A soft writing composition comprising a mixed composition comprising one or more of wax and a fatty acid salt that is solid at room temperature, and an extender and a pigment.