JPH0277463A - Letter erasing material comprising vinyl chloride resin - Google Patents

Abstract

PURPOSE:To obtain the title letter erasing material having little migration of plasticizer, excellent letter erasing properties and ready molding by blending a vinyl chloride resin with a combination of octylbenzyl phthalate and another plasticizer. CONSTITUTION:In a letter erasing material comprising a vinyl chloride resin containing a plasticizer, a combination of octylbenzyl phthalate and another plasticizer is used as a plasticizer. The amount of octylbenzyl phthalate is 10-50wt.% and the rest is another plasticizer. >=8C phthalic ester-based plasticizer, trimellitic ester-based plasticizer and polyester-based plasticizer having >=1,000 molecular weight are used as the other plasticizer.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to an erasable material made of vinyl chloride resin, and more specifically, it has low plasticizer migration, excellent erasability, and is easy to mold. The present invention relates to an easily extinguishable material made of vinyl chloride resin.

[Prior art and problems]

Vinyl chloride resin erasers are currently the mainstream of erasers because of their excellent erasability, feel during erasing, and excellent decorative properties. However, PVC resin erasers require plasticizers, and contain large amounts of dibutyl phthalate, dihebutyl phthalate, dioctyl phthalate, etc.
Plasticizers migrate to polyvinyl chloride, polystyrene, and ABS resins, as well as aromatic oil-based, tung oil-based, nitrocellulose lacquer, and alkyd resin-based coatings, softening the surface of the resin or coating, and causing adhesion. It has the disadvantage that it may cause the surface to peel off or the surface itself may peel off.

In particular, pencil cases, underlays, desk cloaks, etc. are made of polyvinyl chloride.
Pencils are often made of polystyrene, and the coating on pencils is nitrocellulose lacquer or the like, so when the eraser comes into contact with these surfaces, the plasticizer transfers and attacks the pencil case. This phenomenon not only ruins pencil cases and is therefore uneconomical, it also reduces the quality of the eraser itself, and it also contaminates hands and paper, which is an extremely troublesome problem.

In order to solve these problems, (a) the use of plasticizers such as trialkyl trimellitates and tetraalkyl pyromellitates (Japanese Patent Application Laid-Open No. 57-35000), (b) chlorine such as diphenyl chloride, chlorinated paraffin, etc. Use of synthetic plasticizers (Japanese Patent Publication No. 44-25905), (c) Use of isocyanates (Japanese Patent Publication No. 46-42018), (d) Use of natural or synthetic rubber (Japanese Patent Publication No. 55-34990), (e) Starch (Japanese Patent Publication No. 57-22948), (f) Use of a compound obtained by polymerizing unsaturated polyester with a polymerizable monomer in the presence of AIBN (Japanese Patent Publication No. 51-4134), (g)
The use of a methacrylonitrile-butadiene-styrene terpolymer (Japanese Patent Application Laid-Open No. 74139/1983) has been proposed.

However, (a) trimellitic acid-based plasticizers have a high gelation temperature, and when a large amount of trimellitic acid plasticizers is mixed and extruded, it is difficult to cool them with stable dimensions, and it is difficult to use plasticizers with low migration properties. The problem with erasers is that they break easily, have a lot of eraser debris, and are very hard.
Since a large amount of chlorinated plasticizers used as secondary plasticizers are blended, it is unavoidable that these less compatible plasticizers bleed from the surface, wetting other resin products and coatings, and causing ( In c), the molding method and conditions are difficult, and compounds that easily react with isocyanate are not used, so there is a risk of unreacted isocyanate remaining in the eraser, and it is not recommended for erasers that children may lick. There are doubts about safety,
(d) is very difficult to knead and requires an additional step of mixing with rubber, resulting in poor productivity; (e) has little effect on improving migration; (f) has toxicity problems; ) includes problems such as bleeding of chlorinated plasticizers, similar to (b) above, and the reality is that none of them can satisfy all of the requirements of stability, transferability, safety, and moldability. It is.

[Means for solving problems]

In view of this situation, the present inventors conducted intensive research to solve the above problems, and as a result, they discovered that the intended purpose could be achieved by using octylbenzyl phthalate as a plasticizer, and completed the present invention. did.

That is, the first aspect of the present invention is a consumable material made of a vinyl chloride resin containing a plasticizer, wherein the plasticizer is a combination of octylbenzyl phthalate and another plasticizer. A second aspect of the present invention is a disposable material made of a vinyl chloride resin containing a plasticizer, wherein the plasticizer contains octylbenzyl phthalate, dicyclohexyl phthalate, and other plasticizers. Each content is a consumable material made of vinyl chloride resin, which is characterized by being composed of a combination of

The present inventors searched for a plasticizer that has low-temperature gelling properties, is easy to mold into erasers, has excellent elasticity, gives appropriate elasticity to erasers, and has a small amount of migration, and found that octylbenzyl phthalate ( We have found that the above objective can be achieved by finding OBP (hereinafter abbreviated as OBP) and combining it with existing plasticizers for disposable materials.

In the present invention, there are no particular restrictions on the plasticizer to be used in combination with OBP, but a plasticizer that migrates too much is not suitable. A preferred plasticizer is dioctyl phthalate (DO
P), dinonyl phthalate (DNP), diisononyl phthalate (DINP), diisodecyl phthalate (DIDP)
), phthalate ester plasticizers with an alkyl group having 8 or more carbon atoms such as ditridecyl phthalate (DTDP) and diundecyl phthalate (DUP); trioctyl trimellitate (TOTM), diisooctyl trimellitate T
Examples include trimellitic acid ester plasticizers such as 'lOTM; polyester plasticizers having a molecular weight of 11,000 or more. Phthalate plasticizers having less than 8 carbon atoms have extremely poor migration properties, and these may be used alone or in combination of two or more. The usage ratio of OBP and other plasticizers is 10 to 50% by weight of 0BP and 90 to 50% by weight of other plasticizers.
% by weight is preferred, and more preferably the former is 20-45% by weight and the latter is 80-55% by weight.

If the amount of OBP added is less than the above, the gelation temperature will rise and the formability will decrease, and in the case of press working, the surface quality of the resulting letter will be significantly reduced, and the inside will also be hard to form even if it is close to the surface. Sexuality decreases, and lovemaking becomes uneven. Also,
As the hardness increases, especially when erasing with an eraser containing trimellitic acid-based plasticizer as the main ingredient, it feels like being rubbed with soap. On the other hand, if the amount of OBP added is larger than the above, the plasticizer will bleed, resulting in a decrease in transferability.

In the present invention, if very elasticity is not required, OB
P, dicyclohexyl phthalate (hereinafter abbreviated as DCHP) and other plasticizers are used in combination. In this case, the usage ratio is 0BP5-30% by weight, DCHP2-30% by weight.
Preferably 15% by weight and the balance consists of other plasticizers, more preferably 0BPIO to 25% by weight, DCHP
5 to IO weight percent and the balance constitutes other plasticizers. O
If the BP is less than or greater than the above range, the above-mentioned phenomenon will occur, and if the DCHP is less than the above range, the effect of reducing elasticity will be insufficient, and if it is more than the above range, it will become easy to slip during erasing.

The above plasticizer is 6 parts by weight per 100 parts by weight of vinyl chloride resin.
The polyvinyl chloride resin-made expendable material of the present invention is produced in the same manner as in the conventional method. That is, a molding composition consisting of a vinyl chloride resin, a plasticizer, and, if necessary, a stabilizer, a coloring agent, a fragrance, etc. is kneaded, defoamed, and then molded by press molding, injection molding, extrusion molding, etc. The product is molded using a method and cut into predetermined dimensions.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to examples.
The present invention is not limited in any way by these.

Example 1 Polyvinyl chloride paste resin (PSH-10, Kanebuchi Chemical Industry ■) 100 parts by weight Octylbenzyl phthalate (Pracizer B-8, Kyowa Hakko 1?l)
30 parts by weight Dioctyl phthalate 90 parts by weight Calcium carbonate
20 parts by weight dibutyltin mercapto stabilizer
After mixing 2 parts by weight of the above ingredients and defoaming, the mixture was poured into a mold with a depth of about 10 m and press-molded (about 125°C, about 15 m
minutes) and product samples were obtained.

Example 2 Polyvinyl chloride paste resin (PSH-10) 100
Part by weight Octylbenzyl phthalate (Pracizer-B-8) 30
Part by weight Trioctyl trimellitate 90 parts by weight Calcium carbonate 20 parts by weight Dibutyltin mercapto stabilizer 2 parts by weight After mixing and defoaming the above ingredients, it was poured into a mold with a depth of about 10 m and press molded. (
(approximately 130° C. for approximately 17 minutes) to obtain a product sample.

, Example 3 Polyvinyl chloride paste resin (PSH-10>100
Part by weight Octylbenzyl phthalate (Brushizer B-8) 20
Heavy part Dioctyl phthalate 95 parts by weight Dicyclohexyl phthalate (Unimol 6.6, Bayer)
5 parts by weight calcium carbonate
20 parts by weight diptyltin mercapto stabilizer
After mixing 2 parts by weight of the above ingredients and defoaming, the depth is approximately IQ.
It was poured into a ms mold and press-molded (approximately 125℃,
for about 15 minutes) to obtain product samples.

Comparative Example 1 Polyvinyl chloride paste resin (PSH-10) 100
Parts by weight Dibutyl phthalate 30 parts by weight Dioctyl phthalate 90 parts by weight Calcium carbonate
20 parts by weight Dibutyltin mercapto stabilizer 2 parts by weight After mixing and defoaming the above ingredients, it was poured into a mold with a depth of about IQms, and press molded (about 12 parts by weight).
5° C. for about 15 minutes) to obtain a sample.

Comparative Example 2 Polyvinyl chloride paste resin (PSH-10) 100
Parts by weight Diheptyl phthalate 120 parts Calcium carbonate 20 parts Dibutyltin mercapto stabilizer 2 parts by weight After mixing and defoaming, the above ingredients were poured into a mold with a depth of about 10 m, and press molded (
(at about 125° C. for about 15 minutes) to obtain a sample.

Comparative Example 3 Polyvinyl chloride paste resin (PSH-10) 100
Part by weight Dioctyl phthalate 120 parts by weight Calcium carbonate 20 parts by weight Dibutyltin mercapto stabilizer 2 parts by weight After mixing the above ingredients and defoaming, it was poured into a mold with a depth of about 10 mm and press molded. (
(at about 130° C. for about 15 minutes) to obtain a sample.

Comparative Example 4 Polyvinyl chloride paste resin (PS) (-10) 10
0 parts by weight Trioctyl trimellitate 120 parts by weight Calcium carbonate 20 parts by weight Dibutyltin mercapto stabilizer 2 parts by weight After mixing and defoaming the above ingredients, it was poured into a mold with a depth of about 10 fins, Press molding(
(at about 140° C. for about 20 minutes) to obtain a sample.

Comparative example 5, t! IJ Vinyl chloride paste resin (PSH-1
0) 100 parts by weight Dioctyl phthalate 110 parts by weight Dicyclohexyl phthalate (Unimol 6.6) 10 parts by weight Calcium carbonate 20 parts by weight Dibutyltin mercapto stabilizer 2 parts by weight After mixing the above ingredients and defoaming, the depth The sample was poured into a mold of about 10 m and press-molded (about 120° C., about 15 minutes) to obtain a sample.

For the product samples and samples obtained in Examples 1 to 3 and Comparative Examples 1 to 5 above, the erasing rate, transferability, hardness, and gelation temperature were measured, and the results are shown below.

Listed in Table 1. At the same time, a comprehensive evaluation was also posted.

The measurement method was as follows.

■) Erasure rate (%) Test method based on JISK6050.

2) Migration A, Migration test method l) Cut the letter eraser sample into 5 x 2, 5 x 1 cm, sandwich it between polystyrene plates with a diameter of 5 cs*, and then sandwich it between a glass plate from above the polystyrene plate to make the letter eraser. A weight was placed on the sample so that the load was approximately 50 g/-, and the sample was left at 70° C. for 24 hours.

Divide the difference in the weight of the polystyrene plate before and after the test by the contact area with the eraser to calculate the amount of migration (unit ■/d>. Also,
The appearance of the polystyrene plate was observed, and if there was no change before and after the test, it was evaluated as ○, and if the surface deteriorated after the test, it was evaluated as ×.

B. Migration test method 2) Measurement and evaluation were carried out in the same manner as in A above, except that the sample was left at 50° C. for 2 weeks.

C0 migration test method 3) Measurement and evaluation were carried out in the same manner as in A above, except that the sample was left at room temperature for half a year.

D. Migration test method 4) Test method based on JIS 6050.

3) Hardness Test method based on JTSK6050.

4) Gelation temperature The sol obtained by blending and mixing the Examples and Comparative Examples is poured into a groove with a depth of approximately 2R on a temperature gradient plate, an aluminum foil is placed on top of this, and after heating for 3 minutes, aluminum The foil was peeled off from the direction of the highest temperature, and the temperature at which the sol was attached to the aluminum foil was determined to be the gelling temperature.

[Action/Effect]

As you can see, according to the present invention, it is possible to provide a polyvinyl chloride-based resin-made extinguishable material that has excellent properties, migration properties, and moldability. Furthermore, the erasable material of the present invention has appropriate elasticity and feels good when erasing. Furthermore, since the molding conditions and molding method are the same as those for conventional vinyl chloride resin molding materials, there is an advantage in that it is only necessary to change the formulation of the composition.

Claims (1)

[Claims] 1. A consumable material made of a vinyl chloride resin containing a plasticizer, wherein the plasticizer is a combination of octylbenzyl phthalate and another plasticizer. An extinguishable material made of resin. 2. The consumable material according to claim 1, wherein the content is 10 to 50% by weight of octylbenzyl phthalate, and the remainder is other plasticizers. 3. The other plasticizer consists of at least one selected from phthalate plasticizers whose alkyl group has 8 or more carbon atoms, trimellitic acid ester plasticizers, and polyester plasticizers whose molecular weight is 1000 or more. The expendable material according to claim 1 or 2. 4. A consumable material made of a vinyl chloride resin containing a plasticizer, wherein the plasticizer is a combination of octylbenzyl phthalate, dicyclohexyl phthalate, and another plasticizer. The word ``extinguished material'' consists of . 5. The consumable material according to claim 4, wherein the octylbenzyl phthalate is 5 to 30% by weight, the dicyclohexyl phthalate is 2 to 15% by weight, and the remainder is other plasticizers. 6. The other plasticizer consists of at least one selected from phthalate plasticizers whose alkyl group has 8 or more carbon atoms, trimellitic acid ester plasticizers, and polyester plasticizers whose molecular weight is 1000 or more. The expendable material according to claim 4 or 5.