JP2002200890A - Eraser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an eraser wherein when the eraser is incinerated, no harmful gas containing chlorine is generated, and incineration residues are collected as is a case with a vinyl chlorine eraser. SOLUTION: In the eraser, eraser containing no chlorine compound is incorporated in a base material, a filler, a plasticizer, a stabilizer, etc., while a small quantity of an uncrosslinked ethylene-propylene rubber is added to the eraser.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eraser for erasing handwriting such as a pencil and a mechanical pencil.

[0002]

2. Description of the Related Art Erasers are generated when an eraser is used.
The scraps are incinerated as garbage. At this time, if a chlorine compound is contained in the eraser waste, a chlorine-containing toxic gas is generated, which causes air pollution. 2. Description of the Related Art Conventionally, a polyvinyl chloride-based eraser, which has been the mainstream of erasers, causes air pollution because the base material polyvinyl chloride is a chlorine compound containing a large amount of chlorine. Therefore, in recent years, research and development of an eraser containing no chlorine compound has been performed.

[0003] Erasers made of chlorine-based compounds include polyvinyl chloride-based erasers based on polyvinyl chloride,
Chlorinated polyethylene without using polyvinyl chloride,
Chloroprene rubber, white sub, those containing chlorinated paraffin, etc., specifically, those comprising ethylene vinyl acetate copolymer, ethylene propylene copolymer, white sub, chlorine plasticizer, etc. (JP-B-52-44545). No.)
And those composed of chlorinated polyethylene, white sub, chlorinated paraffin and the like (JP-B-59-53197).

[0004] Erasers made of non-chlorine compounds are composed of a base material, a filler, a plasticizer,
It is made of a material that does not contain a chlorine compound in a stabilizer or the like. As an example of an eraser made of a non-chlorine compound,
A styrene-butadiene-styrene block copolymer containing 40% by weight of butadiene and polybutadiene and chalk (Japanese Patent Publication No. 2-13638); a styrene-isoprene-styrene block copolymer and polybutadiene;
One composed of chalk (Japanese Patent Publication No. 5-45440), one composed of an amorphous polyalphaolefin and an olefin-based thermoplastic elastomer (JP-A-5-92692), an ethylene-vinyl acetate copolymer and / or an attack tactic Polypropylene and styrene-butadiene copolymer, polybutene, titanium oxide, diatomaceous earth (JP-B-57-32680), ethylene ethyl acrylate copolymer and styrene-butadiene-styrene copolymer, calcium carbonate, naphthenic oil (JP-A-61-57398), styrene-based thermoplastic elastomer, polyethylene, terpene resin, calcium carbonate, process oil (JP-B-4-3)
9440) and the like.

[0005]

However, although the eraser made of a non-chlorine compound has no significant difference in the erasure performance as compared with the polyvinyl chloride eraser, the eraser is less cohesive. When erasing, a polyvinyl chloride-based eraser sticks to the
~ Several lumps, erased scum is well organized. On the other hand, in an eraser made of a non-chlorine-based compound, particularly in an eraser using a styrene-based thermoplastic elastomer as a base material, the fineness of the eraser dust is remarkable, the fine eraser dust spreads on the paper surface, and the eraser dust is discarded. It was very difficult.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an eraser made of a non-chlorine-based compound and having an eraser that is well organized.

[0007]

According to the present invention, there is provided an eraser comprising a non-chlorine compound, wherein the eraser comprises 0.1 to 10% by weight, based on the substrate, of an uncrosslinked ethylene propylene rubber. And

Hereinafter, the present invention will be described in detail. The eraser made of a non-chlorine compound is a material that does not contain a chlorine compound in a base material, a softener, a filler, a stabilizer, and the like, that is, a material that does not contain a chlorine compound in a compounding material constituting the eraser. is there. The base material is a main compounding material of the eraser, and in the present invention, a resin or rubber containing no chlorine is used. Examples of the resin or rubber include a thermoplastic elastomer, a soft resin, and a crosslinked rubber.

A thermoplastic elastomer is a polymer material which exhibits the properties of a vulcanized rubber at room temperature, but is plasticized at a high temperature and can be molded by an ordinary plastic processing machine. A rubber component having entropy elasticity in its molecule (software) Segment) and a molecular constraint component (hard segment) for preventing plastic deformation. Thermoplastic elastomers are roughly classified into styrene, olefin, ester, urethane and others. Of these, styrene-based and olefin-based materials are particularly preferred as eraser materials because they are not too hard and erased residue is easily generated.

The styrene-based thermoplastic elastomer is a block copolymer in which both ends of a rubber component are sandwiched between molecular constrained components, a two-block copolymer of a rubber component and a molecular constrained component, and the molecular constrained component is polystyrene. It is. As a classification of the rubber component in which both ends are sandwiched between molecular constrained components, the rubber component is a styrene-butadiene-styrene copolymer in which polybutadiene is used, a styrene-isoprene-styrene copolymer in which polyisoprene is used, and hydrogenated polybutadiene, Styrene-ethylene butylene-styrene copolymer as butylene, styrene-ethylene propylene-styrene copolymer as hydrogenated polyisoprene and polyethylene propylene as ethylene propylene, and styrene as polybutadiene butylene selectively hydrogenated specific portions of polybutadiene. Butadiene butylene-styrene copolymer and styrene-ethylene ethylene propylene-styrene copolymer obtained by hydrogenating polyisoprene-butadiene to obtain polyethylene ethylene propylene.

An example of a commercially available styrene-based thermoplastic elastomer is described below. Examples of the styrene-butadiene-styrene copolymer include tufprene A, 125 and 20.
0, 315, 912, Solprene T-411, T
-414, T-475, Asaprene T-420, T
-430, T-431, and T-450 (all manufactured by Asahi Kasei Corporation), Clayton D-1101, and D-11
02, D-1155, D-KX405, D-KX
408, D-KX410, D-KX414, D-
KX415, D-1116, D-1184, D-
1122X (Craton Polymer Japan Co., Ltd.
Manufactured). Examples of the styrene-isoprene-styrene copolymer include Kraton D-1107 and D-107.
Nos. 1161, D-1111 (manufactured by Clayton Polymer Japan KK), and Tuftec H1062 and H1 as styrene-ethylenebutylene-styrene copolymers
052, H1141, H1041, H1053,
H1043 (all manufactured by Asahi Kasei Corporation), Clayton G1650, G1651, G1652, G16
54X (Craton Polymer Japan Co., Ltd.
Septon 8004, 8006, 8007 (Kuraray Co., Ltd.), Lavalon SJ4400, SJ
5400, same SJ6400, same SJ7400, same SJ8
400, SJ9400, SE5400, SE64
00, SE7400, SE8400, ME530
1, ME6301, MJ4300, MJ530
2, MJ6300, MJ7300, MJ830
MJ9301 (all manufactured by Mitsubishi Chemical Corporation) and the like. Examples of styrene-ethylene propylene-styrene copolymers include Septon 2002, 2005, and 2
006, 2007, 2043, 2063, 21
04 (Kuraray Co., Ltd.), Clayton G1730
(Manufactured by Clayton Polymer Japan Co., Ltd.). Examples of the styrene-butadienebutylene-styrene copolymer include Tuftec P JT-82 and JT-83.
JT-84P (above, manufactured by Asahi Kasei Corporation) and the like. Septon 4033 and 405 as styrene-ethylene-ethylene-propylene-styrene copolymers
5, 4077 (all manufactured by Kuraray Co., Ltd.) and the like.

Further, as the diblock copolymer of the molecular constrained component of polystyrene and the rubber component, Kraton G1 of styrene-ethylene propylene-diblock copolymer may be used.
701 (manufactured by Clayton Polymer Japan KK), Septon 1001, and 1050 (manufactured by Kuraray Co., Ltd.). Further, a combination of a diblock copolymer and a block copolymer in which both ends of a rubber component are sandwiched between molecular constrained components is also known, and as these, styrene-isoprene-diblock copolymer is known. D-1112, D-1113 and D-1 which are mixtures of styrene-isoprene-styrene-triblock copolymers
117, D-1119, D-1124, D-KX
406, the same D-KX603 (manufactured by Clayton Polymer Japan KK), or Clayton D-1118, which is a mixture of a styrene-butadiene-diblock copolymer and a styrene-butadiene-styrene-triblock copolymer.
(Clayton Polymer Japan Co., Ltd.), styrene-ethylenebutylene-diblock copolymer and styrene-
Clayton G1657 and G1726 (both manufactured by Clayton Polymer Japan Ltd.), which are mixtures of ethylene butylene-styrene-triblock copolymers, and the like.

The olefin-based thermoplastic elastomer has a molecular constraint component composed of a polyolefin mainly composed of polyethylene and polypropylene, and a rubber component composed of an olefin-based rubber, for example, ethylene propylene rubber or ethylene propylene terpolymer rubber. Types of olefin-based thermoplastic elastomers include those obtained by partially crosslinking a rubber component and those obtained by completely crosslinking.

An example of a commercially available olefin-based thermoplastic elastomer is described below. Sumitomo TPE820, TPE822 and TPE82 as partially crosslinked
1, TPE824, TPE1710, TPE53
8, TPE3650, TPE5260, TPE5
280 (all manufactured by Sumitomo Chemical Co., Ltd.), Thermorun 3
551, 3652, 3602, 3702, 38
01, 3981 (all manufactured by Mitsubishi Chemical Corporation), Mirastomer 5030, 6030, 7030, 803
0, 8032, 9020 (above, Mitsui Chemicals, Inc.)
Manufactured). Santoplane 201-55, 201-64, 201
-73, 201-80, 201-87, 203-
40, 203-50, 211-45, 211-5
5, 211-64, 211-73, 211-8
0 and 211-87 (all manufactured by AES Japan K.K.).

Examples of the soft resin include ethylene vinyl acetate copolymer, ethylene ethyl acrylate copolymer, attack polypropylene, ionomer resin, amorphous polyalphaolefin, and styrene oligomer.

Examples of the crosslinked rubber include crosslinked natural rubber and synthetic rubber. As the synthetic rubber, styrene butadiene rubber, nitrile rubber, isoprene rubber,
Examples thereof include butadiene rubber, butyl rubber, and ethylene propylene rubber.

The uncrosslinked ethylene propylene rubber is used to collect erased scraps, and it is necessary to use 0.1 to 10 parts by weight based on 100 parts by weight of the base material. If the amount used is less than 0.1 part by weight, the effect of collecting erased scraps cannot be sufficiently obtained, and if used in excess of 10 parts by weight, the surface of the eraser body and the erased scraps become sticky, and the erased scraps are printed on the paper. It happens to stick.

The ethylene propylene rubber used in the present invention is a copolymer of ethylene and propylene (hereinafter referred to as EPM) or an unsaturated bond introduced by copolymerizing ethylene, propylene and a non-conjugated diene monomer. It refers to an ethylene-propylene-diene terpolymer (hereinafter referred to as EPDM) capable of sulfur crosslinking, a quaternary polymer using two kinds of diene in combination, and the like. EPDM is used as a diene to be copolymerized with ethylene and propylene in view of copolymerization reactivity and in consideration of 5-ethylidene-2-norbornene (hereinafter, referred to as ENB) and dicyclopentadiene (hereinafter, referred to as ENB).
It is called DCPD. ), 1,4-hexadiene (hereinafter, H
It is called D. ) Can be used alone or in combination of two or more.

An example of a commercially available ethylene propylene rubber is described below. Mitsui EPT0045 as EPM
(Manufactured by Mitsui Chemicals, Inc.), JSR EP11, T794
2, EP01P, EP02P, EP07P, E
P912P, EP922P, EP941P, EP
961SP (all manufactured by JSR Corporation), and the like.
EPDMs using DCPD as a diene include Mitsui EPT1035, 1045, 1070, and 10
70L (all manufactured by Mitsui Chemicals, Inc.), JSR EP75
F (manufactured by JSR Corporation) and the like. An EPDM using ENB as a diene is Mitsui EPT301.
2P, 3042E, 3045, 3070, 30
62E, 3072E, 3085, 3091, 3
090E, 3095, 4010, 4021, 1
4030, 4045, 4070, 4095, 8
075E (all made by Mitsui Chemicals, Inc.), JSR EP4
3, EP93, EP21, EP22, EP2
4, EP25, EP27, EP51, EP57
F, EP57C, EP103AF, EP107
F, T7141, EP33, EP35, EP3
7F, EP65, EP57P, EP96, EP
98, T7501EF and EP503EF (J.
SRDM), and a quaternary EPDM using DCPD and ENB as diene is JSR
T7881F, EP801E (above, JSR Corporation)
Manufactured). These can be used alone or in combination of two or more.

In order to include uncrosslinked ethylene propylene rubber in the eraser, it can be achieved by not using a crosslinking agent in the compounding material. Alternatively, even when a cross-linked rubber is used for the base material and a cross-linking agent is used for the compounding material, the ethylene-propylene rubber is not cross-linked by kneading and molding at a temperature as low as 160 ° C. or less, at which the ethylene-propylene rubber is cross-linked. Can also be contained. As another method, for example, as ethylene propylene rubber, E
When PM is combined with sulfur as a cross-linking agent, the EPM is not cross-linked regardless of the temperature. Employing the above-mentioned conventionally known method allows the uncrosslinked ethylene propylene rubber to be contained in the eraser.

Further, a softener can be used to make the eraser soft and easy to wear. Examples of the softening agent include petroleum-based oils and liquid polymers that do not contain chlorine.

The petroleum-based oil is a mixture of paraffin-based hydrocarbons, naphthenic ring-based hydrocarbons and aromatic hydrocarbons derived from petroleum. Extender oil for oil and rubber,
Liquid paraffin, spindle oil, machine oil and the like in addition to the process oil for compounding are known. Liquid paraffin includes industrial liquid paraffin described in JIS K2231 and standardized products of the Japanese Pharmacopoeia Food Sanitation Law.
Christol 5 conforms to these standards.
2, 70, 72, 102, 142, 172,
202, 262, 322, 352 (all manufactured by Esso Oil Co., Ltd.), Daphne CP15N, CP32
N, CP38N, CP68N, KP8, KP1
5, KP32, KP68, and KP100 (all manufactured by Idemitsu Kosan Co., Ltd.).

Further, petroleum-based oils are classified into three types, paraffin-based oils, naphthenic-based oils, and aromatic-based oils, and each is exemplified. Paraffin oils are Diana PX-32 and PX-9
0, PW-32, PW-90, PW-380, PS-32, PS-90, and PS-430 (all manufactured by Idemitsu Kosan Co., Ltd.), Shellflex 210, and 31
0, 790, 1210, 1310, Lubflex 26, 100, 460 (all Shell Chemical Co., Ltd.)
Manufactured), Kyoishi process P200, P300, 500
Kyoishi EPT750 (all manufactured by Kyodo Sekiyu KK) and the like. Naphthenic oils are Diana NS-24, NS
-100, NM-26, NM-280, NP-2
4, NU-80, NF-90 (all manufactured by Idemitsu Kosan Co., Ltd.), Shelflex 371JY, 371
N, 451, N-40, 22, 22R, 32
R, 100R, 100S, 100SA, 220
RS, 20S, 260, 320R, 680 (all manufactured by Shell Chemical Co., Ltd.), Kyoishi process R25, R
R200, R200, and R1000 (all manufactured by Kyodo Sekiyu KK). Aromatic oil is Diana A
C-12, AC-460, AH-16, AH-5
8 (manufactured by Idemitsu Kosan Co., Ltd.), Deuterex 72
9UK, 739 (all manufactured by Shell Chemical Co., Ltd.), Kyoishi Process X50, X140 (all, Kyodo Oil Co., Ltd.)
Manufactured).

As the liquid polymer, liquid polyisoprene, liquid polybutadiene, polybutene, a liquid polymer of alpha-olefin, a liquid polymer of ethylene and alpha-olefin, and the like are known. Examples of the polybutene include Nisseki Polybutene LV-5, LV-10, LV-25, LV-50, LV-100, and HV-15 (all manufactured by Nippon Petrochemical Co., Ltd.) and Idemitsu Polybutene 0H, 5H, 1
0H, 15H, 0R, and 15R (all manufactured by Idemitsu Petrochemical Co., Ltd.). Examples of the liquid polymer of alpha-olefin include Mobil SHF21 and SHF.
41, the same SHF61, the same SHF82, the same SHF401,
SHF1001 (above, manufactured by Mobile Chemical Co., USA) and the like. Examples of liquid polymers of ethylene and alpha-olefin include Lucant A-5202, A-6002, A-5215, A-5515, A-5215.
-5260, A-5560, and A-5329H (all manufactured by Mitsui Chemicals, Inc.).

A filler may be used to make the eraser hard and easy to wear. Examples of the filler include organic powders and inorganic powders containing no chlorine.
Organic powder is rubber powder, resin powder, etc., and inorganic powder is, for example, heavy calcium carbonate, light calcium carbonate,
Magnesium carbonate, titanium oxide, kaolin, clay, silica and the like.

Further, a stabilizer, a coloring agent and the like which do not contain a chlorine-based compound can be appropriately used.

The production of the eraser is carried out by kneading the above components with a conventional heating type kneader such as a heated two-roll mill, a pressure kneader or a Banbury mixer, and using a molding machine such as a press machine, an injection molding machine or an extrusion molding machine. Can be obtained using

[0028]

[Effect] By blending a small amount of ethylene propylene rubber with an eraser made of a non-chlorine compound without cross-linking, the eraser scum generated at the time of use can be slightly sticky, and the eraser stalks are united, and the scum on the paper surface is reduced. It is not scattered finely.

[0029]

The present invention will be described below in more detail with reference to examples. Among the above components, Septon 2002 and Mitsui EPT0045 were kneaded with a two-roll heated to 120 ° C. After sufficient kneading, the remaining components were added thereto, and kneading was further performed. Put the finished kneading in the mold
Press molding was performed at 20 ° C. for 10 minutes to obtain a block-shaped eraser.

[0030] Among the above components, Sumitomo TPE1710 and Clayton G165
0 and Mitsui EPT1045 were kneaded with a two-roll heated at 150 ° C., and the other steps were the same as in Example 1 to obtain an eraser.

[0031] In the above components, Septon 2007 and Sorprene T-41
1. After kneading JSR EP11 with a two-roll heated to 120 ° C., the rest was the same as in Example 1 to obtain an eraser.

[0032] In the above components, Septon 2007 and Septon 4033, J
After kneading SR24 with a two-roll heated to 120 ° C., an eraser was obtained in the same manner as in Example 1 except for kneading.

[0033] After kneading Septon 2002 with two rolls heated to 120 ° C. in the above components, the rest was the same as in Example 1 to obtain an eraser.

[0034] After kneading Septon 2002 and Mitsui EPT0045 with the two rolls heated to 120 ° C.,
The rest was the same as in Example 1 to obtain an eraser.

[0035] After kneading Septon 2002 and Mitsui EPT0045 with the two rolls heated to 120 ° C.,
The rest was the same as in Example 1 to obtain an eraser.

Using the erasers obtained in Examples 1 to 4 and Comparative Examples 1 to 3, the erasure rate was measured according to the method of JIS S6050. The erasers obtained in Examples 1 to 4 and Comparative Examples 1 and 2 all had erasure rates of 80% or more and satisfied the JIS standard. However, in the eraser obtained in Comparative Example 3, the eraser was stuck on the erased paper surface, and it was impossible to measure. Moreover, when the handwriting of the pencil and the mechanical pencil was erased by hand, Examples 1 to 4 disappeared well and erased residues were collected. In Comparative Examples 1 and 2, although erased scum appeared, it was scattered finely and hardly collected. In Comparative Example 3, when scraping with force, erased scraps stuck to the paper surface.

[0037]

As described in detail above, the eraser according to the present invention does not use a chlorine-containing compound as a raw material, and therefore does not generate chlorine-containing toxic gas during incineration. It has an excellent property that an eraser is formed like a polyvinyl chloride eraser.

Claims (1)

[Claims] 1. An eraser comprising a non-chlorine compound, wherein the eraser is 0.1 to 10% by weight based on a base material.
Eraser containing uncrosslinked ethylene propylene rubber.