KR101432773B1 - Reworkable thermo-reversible elastomer with high abrasion-resistant and method for preparing the same - Google Patents

Abstract

The present invention relates to a thermally reversible elastomer composition excellent in abrasion resistance and mechanical properties and capable of reprocessing. More specifically, the present invention relates to a thermally reversible elastomer composition capable of reworking, in which a monomer containing an acid group is grafted to an elastic rubber, a nanosilica hybrid compound is reacted with the monomer, onium salt, or amide structure, the nanosilica hybrid structure together with the structure in which the network is formed through the secondary bonding of the ionic bond and the hydrogen bond has a higher abrasion resistance than the elastomer crosslinked with sulfur or peroxide As a result of the reworkability as described above, since it is not only environmentally friendly but also has excellent abrasion resistance and mechanical properties as well as mechanical properties, it can be used for automobile, shipbuilding, building materials Conventional It relates to a heat reversible elastomer composition to replace the elastic body can be replaced by material of the product used.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermally reversible elastomer which is excellent in abrasion resistance and can be reprocessed, and a method of manufacturing the same. BACKGROUND OF THE INVENTION < RTI ID = 0.0 &

The present invention relates to a thermally reversible elastomer which is excellent in abrasion resistance and can be reprocessed and a method for producing the same. More specifically, the present invention relates to a thermally reversible elastomer which is excellent in abrasion resistance and which can be reprocessed by reacting an organic nano- Thermally reversible elastomers which exhibit mechanical properties superior to conventional cured crosslinked elastomers and exhibit excellent abrasion resistance, dissociate at high temperatures, and recombine at low temperatures, and to a process for producing the same.

The elastomers which are widely used throughout the industry such as the construction industry and the automobile industry are generally used after being cross-linked with sulfur or peroxide, and most of them can not be reprocessed after being used, and some of them are powdered and reused Only a fraction of them are recycled. In addition, there is a problem of secondary contamination such as dioxin when incinerating the used elastomer after use. As the amount of disposal of elastomers increases, the problem of environment depletion due to resource depletion and abandoned products has been raised.

 Therefore, in order to overcome the disadvantages of ordinary crosslinked elastomer, thermoplastic elastomer (TPE), which has the elasticity of the rubber due to the physical agglomeration of the hard segment at room temperature and the physical agglomeration is disassociated at high temperature, In recent years, environmental problems have been highlighted most in society and industry. Research and development has been actively carried out to replace rubber with such materials, and the application field is gradually expanding.

However, since the thermoplastic elastomer has a high productivity because it has no complicated crosslinking process and has an advantage of being able to use existing plastic processing apparatus without modification, compared with the conventional crosslinked rubber having a chemical crosslinking structure, the heat resistance, durability, Strain, abrasion resistance, and the like.

 Accordingly, in order to overcome such disadvantages, a thermoplastic vulcanizate (TPV), which is a material having elasticity similar to that of a conventional thermosetting rubber, has been developed due to the blend structure of a soft rubber and a hard plastic and a soft rubber portion bridged .

However, since plasticity is imparted mainly by polypropylene or polyethylene, it is difficult to use the filler in an amount of 30 wt% or more, and the permanent compression strain is inferior to the crosslinked rubber composition in physical properties.

 In recent years, as a means for solving such problems, there have been many researches on elastomers which exhibit physical properties of crosslinked elastomer and which have thermoreversibility and can be reused.

In the study of thermoreversible elastomers, an elastomer having a modulus value similar to that of a crosslinked elastomer was developed in Yokohama Rubber, Japan, by adding active hydrogen compounds such as amines, alcohols and thiols to maleophilic liquid isoprene rubber, DSM developed an elastomer that exhibits physical properties through hydrogen bonding and ionic bonding using a maleic ethylene-propylene copolymer. In addition, Huarony in China has developed a butyl rubber with thermoreversible properties by reacting 4-aminouracil with brominated butyl rubber.

However, the thermally reversible elastomers developed so far can be reprocessed and the mechanical properties are improved to a great extent, but the properties such as sensibility quality and permanent compression toughness are still insufficient as compared with crosslinked elastomers.

In addition, Japanese Patent Application Laid-Open No. 10-1997-0027193 of Patent Document 1 proposes a technique for "thermoplastic vulcanizing rubber obtained from EPDM or conjugated diene rubber and isobutylene rubber", but the thermoplastic vulcanizing rubber is partially To about 10 to 90 parts by weight of a crosslinked rubber compound. The rubber composition is thermoplastic and has a modulus similar to that of a vulcanized rubber. However, despite its excellent performance, there is a problem in that the elastic restoring force is inferior due to the rubber composition of the partial crosslinking .

: Korean Patent Publication No. 10-1997-0027193 "Thermoplastic vulcanizing rubber obtained from EPDM or conjugated diene rubber and isobutylene rubber"

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a process for producing an elastomer composition, which comprises reacting an elastomer having a reactive monomer grafted with an acidic group and an organic / inorganic nanosilica hybrid compound, A thermally reversible elastomer which is dissociated at a high temperature and recombined at a low temperature to be reworkable, and a method for producing the same.

The present invention relates to a process for producing an elastomer by grafting an acrylic monomer containing an acid structure to an elastic polymer resin and then producing an elastomer by introducing a nanosilica hybrid through reaction between an acid group and an amine group, A thermally reversible elastomer exhibiting mechanical properties superior to crosslinked elastomers by covalent bonding by peroxide or the like and excellent in abrasion resistance, and a process for producing the same.

In addition, the thermally reversible elastomer composition excellent in abrasion resistance and mechanical properties as described above and capable of reprocessing can be reprocessed, and thus it is environmentally friendly as well as excellent in abrasion resistance and mechanical properties, so that conventional crosslinked elastomers such as automobile, shipbuilding, A thermally reversible elastomer and a method of manufacturing the same.

In order to solve the above problems, according to the present invention,

The present invention relates to a process for producing a reactive monomer having an acid group grafted with an acid group represented by the following general formula (1) and reacting with an organic / inorganic nanosilica hybrid compound having an amine group end represented by the following general formula (2) Thermally reversible elastomer as a solution to the problem.

(Formula 1)

In Formula 1,

R is a C2 to C10 hydrocarbon derivative containing a double bond of CH ₂ = CH-, CH ₃ -CH = CH-, HOOC-CH = CH- or HOOC = CH- and contains a carboxyl group in the molecule

(2)

In Formula 2,

의 구조이며, Si-O-Si 결합구조를 갖는 실리카 화합물이고,Z is

And is a silica compound having a Si-O-Si bond structure,

Y is an element containing a non-covalent electron pair selected from N, O or S,

R ^{1 is a} C ₁ to C ₁₂ aliphatic, alicyclic or aromatic hydrocarbon derivative,

R ^{2 is a} C ₂ to C ₁₈ aliphatic hydrocarbon derivative, a C ₄ to C ₁₅ alicyclic hydrocarbon derivative or a C ₆ to C ₁₅ aromatic hydrocarbon derivative,

R ³ is a hydrocarbon derivative having a C ₁ to C ₂₀ aliphatic, alicyclic or aromatic structure.

At this time, the elastomer in which the reactive monomer having an acid group is grafted,

It is preferable that 1 to 20 parts by weight of a monomer containing an acid group is added to 100 parts by weight of an elastic rubber put into an organic solvent to effect a graft reaction.

In addition, the thermo-reversible elastomer may contain,

It is preferable to add 30 to 100 parts by weight of the nano-silica hybrid compound to 100 parts by weight of the elastic rubber in which the reactive monomer grafted with the above-mentioned acid group is grafted.

In addition, the above-

Butadiene rubber, nitrile rubber, chloroprene rubber, ethylene-propylene rubber, ethylene-propylene-diene rubber, butyl rubber, acrylic rubber, or a combination of two or more thereof.

The present invention also relates to a process for producing an elastomer comprising the steps of: 1) preparing an elastomer having an acid group grafted with an acid group represented by the formula 1 of claim 1;

2) reacting the organic and inorganic nanosilica hybrid compound represented by the formula (2) of claim 1 with an amine group terminal;

Which is excellent in abrasion resistance and can be reprocessed, as another solution to the problem.

The present invention relates to a rubber composition which is obtained by grafting a monomer containing an acid group to an elastic rubber and reacting it with a nanosilica hybrid compound to have an onium salt or amide structure, And the nanosilica hybrid structure together, they exhibit better wear resistance and mechanical properties than the elastomer crosslinked with sulfur or peroxide in the prior art, but dissociate at a high temperature and recombine at a low temperature, It is not only environmentally friendly but also has excellent abrasion resistance and mechanical properties, so that it is possible to replace the conventional crosslinked elastomeric materials such as automobiles, shipbuilding, and building materials with the materials of the products to be used.

1 is a view for confirming an elastic body to which a silica hybrid is bonded

In order to achieve the above-mentioned effects, the present invention relates to a thermally reversible elastomer which is excellent in abrasion resistance and can be reprocessed, and a method of manufacturing the same. It will be omitted so as not to disturb the gist of the present invention.

Hereinafter, a thermally reversible elastomer having excellent abrasion resistance and reworkability according to the present invention will be described in detail as follows.

The present invention relates to a process for producing a reactive monomer having an acid group grafted with an acid group represented by the following general formula (1) and reacting with an organic / inorganic nanosilica hybrid compound having an amine group end represented by the following general formula (2) Thermally reversible elastomer.

(Formula 1)

In Formula 1,

R is _{CH 2 = CH-, CH 3 -CH} = CH-, a hydrocarbon derivative of a C2 ~ C10 containing a double bond-CH = CH- or HOOC = HOOC CH-, may include a carboxyl group in the molecule. Examples of the compound having the structure of formula (1) include acrylic acid, methacrylic acid, and the like.

(2)

In Formula 2,

의 구조이며, Si-O-Si 결합구조를 갖는 실리카 화합물이고,Z is

And is a silica compound having a Si-O-Si bond structure,

Y is an element containing a non-covalent electron pair selected from N, O or S,

R ^{1 is a} C ₁ to C ₁₂ aliphatic, alicyclic or aromatic hydrocarbon derivative,

R ^{2 is a} C ₂ to C ₁₈ aliphatic hydrocarbon derivative, a C ₄ to C ₁₅ alicyclic hydrocarbon derivative or a C ₆ to C ₁₅ aromatic hydrocarbon derivative,

R ³ is a hydrocarbon derivative having a C ₁ to C ₂₀ aliphatic, alicyclic or aromatic structure.

The thermoplastic elastomer grafted with the reactive monomer having an acidic group is grafted to 100 parts by weight of the elastic rubber put into the organic solvent by the addition of 1 to 20 parts by weight of a monomer containing an acid group, Wherein 30 to 100 parts by weight of the nano-silica hybrid compound is added to 100 parts by weight of the elastic rubber put into the solvent to effect the reaction.

The elastic rubber may be used alone or in combination of two or more among butadiene rubber, isoprene rubber, styrene-butadiene rubber, nitrile rubber, chloroprene rubber, ethylene-propylene rubber, ethylene-propylene-diene rubber, butyl rubber, .

The technical construction of the thermo-reversible elastomer will be described later in detail in the description of the method for producing the thermo-reversible elastomer, and a detailed description thereof will be omitted here.

Hereinafter, the method for producing thermally reversible elastomer according to the present invention will be described in detail as follows.

The present invention relates to a process for preparing an elastomer comprising the steps of: 1) preparing an elastomer in which a reactive monomer having an acid group represented by Formula 1 is grafted;

2) reacting the organic and inorganic nano-silica hybrid compound represented by Formula 2 with the amine group terminal;

The present invention relates to a thermally reversible elastomer having excellent abrasion resistance and reworkability.

The elastomer obtained by grafting the reactive monomer having an acid group in 1) above is prepared by charging 5 to 15% by weight of an elastic rubber to 85 to 95% by weight of an organic solvent, 1 to 20 parts by weight of monomers are added and mixed, and 0.1 to 5 parts by weight of an azo initiator is added thereto to carry out a graft reaction.

In the present invention, the elastic rubber is preferably added to 85 to 95% by weight of the organic solvent and 5 to 15% by weight of the elastic rubber. When the amount of the elastic rubber is less than 5% by weight, the graft reaction may not be performed well, and when the amount is more than 15% by weight There is a possibility that the gel becomes a gel during the grafting reaction.

In order to introduce a nanosilica hybrid, the present invention first grafts an acrylic monomer having an acid group having the structure shown in Formula 1 to the main chain of the elastomer, thereby forming a hydrogen bond and an ionic bond, thereby exhibiting crosslinking properties. In this case, the monomer is used in an amount of 1 to 20 parts by weight based on 100 parts by weight of the elastic polymer resin. When the monomer is used in an amount of less than 1 part by weight, the mechanical properties and the permanent compression toughness are extremely low. When the monomer is used in an amount exceeding 20 parts by weight, There is a concern.

The reaction initiator is used for a radical reaction, and it is preferable that 0.1 to 5 parts by weight of a peroxide-based or azo-based initiator is added to 100 parts by weight of the elastic rubber to effect a graft reaction. When the amount of the initiator is less than 0.1 part by weight, the reaction rate is low and the grafting rate is low. When the amount of the initiator is more than 5 parts by weight, the reaction rate is too fast to produce a gel.

On the other hand, the initiator may be a conventional peroxide initiator such as dialkyl peroxide, tertiary butyl hydroperoxide, azo type initiator 2,2'-azobis (isobutyronitrile), 1,1'-azobis Cyclohexanecarbonitrile) and the like can be used.

In the present invention, 30 to 100 parts by weight of a nanosilica hybrid compound having the structure of the above formula (2) is added to an elastomer grafted with a reactive monomer having an acid group in the above 2), and the mixture is added at a temperature of 80 to 120 ° C (See Reaction Scheme 1 below), and then reacting the thus synthesized compound with a compound represented by the following formula (1), after forming an onium salt (reaction at room temperature) or an amide structure (reaction at 80 to 120 캜) Separate and refine into acetone-soluble and non-soluble parts to produce pure elastomers from which unreacted materials have been removed.

(Scheme 1)

The nanosilica hybrid compound may be used in an amount of 30 to 100 parts by weight based on 100 parts by weight of the polymer resin. When the amount is less than 30 parts by weight, When the physical properties are lowered and the amount exceeds 100 parts by weight, the abrasion resistance is excellent, but the elasticity and elongation percentage of the elastic body may be lowered.

Meanwhile, the nanosilica hybrid compound used in the present invention is synthesized by the following method.

First, an alkoxysilane having an Y-containing element such as a mercapto group, an amino group, an alcohol group and an epoxy group capable of reacting with an isocyanate at the terminal is reacted with a diisocyanate at a reaction temperature of room temperature to 80 ° C to obtain a terminal isocyanate group To prepare a material as shown in the following reaction formula (2).

(Scheme 2)

Here, R ¹ represents a C ₁ -C ₁₂ aliphatic, alicyclic or aromatic hydrocarbon derivative or the like. Such compounds include methyl, ethyl, propyl, butyl, hexamethyl, cyclohexyl, phenyl, and dodecanemethyl groups. Suitable compounds for R ² include C ₂ to C ₁₈ aliphatic hydrocarbon derivatives such as butylene, hexamethylene, octamethylene, dodecanemethylene, and the like, and C ₄ to C ₁₅ alicyclic hydrocarbon derivatives, for example, Isophorone, cyclohexylene, isocyanatocyclohexyl, and the like, or C ₆ to C ₁₅ aromatic hydrocarbon derivatives such as phenylene, naphthalene, diphenylmethyl, and toluylene. R ⁴ includes a hydrogen atom and represents a C ₁ -C ₈ alkyl group or an aryl group, and examples thereof include a methyl group, an ethyl group, a butyl group, a propyl group, and an octyl group.

In the next reaction, the material synthesized in the above Reaction Scheme 2 and the diamine compound are stirred at a temperature of 60 ° C for 1 to 3 hours until all the isocyanates are reacted to form an amine-terminated alkoxysilane complex .

(Scheme 3)

Here, R ₃ is a compound having an aliphatic, alicyclic or aromatic structure of C ₁ to C ₂₀ .

Then, a silane compound containing four alkoxy groups is added to the alkoxysilane complex at the terminal of the amine group synthesized by the reaction scheme 3, and the catalyst and water are added thereto to hydrolyze the alkoxide group to convert the alkoxide group into hydroxy (OH ) Group, followed by condensation of Si-OH to produce a nanosilica compound having the structure of Formula 2, which has a Si-O-Si bond structure. The reaction temperature is from room temperature to 80 ° C for 3 to 24 hours The reaction is terminated by stirring. As the catalyst used herein, strong acids such as hydrochloric acid, sulfuric acid and nitric acid, and weak acids such as acetic acid and phosphoric acid can be used, and basic catalysts such as potassium hydroxide, sodium hydroxide and amine can also be used.

(Scheme 4)

Wherein Y is an element containing a non-covalent electron pair selected from N, O or S, R ¹ is a C ₁ to C ₁₂ aliphatic, alicyclic or aromatic hydrocarbon derivative, R ² is C ₂ to C _A C ₄ to C ₁₅ alicyclic hydrocarbon derivative or a C ₆ to C ₁₅ aromatic hydrocarbon derivative; and R ³ is a hydrocarbon derivative having a C ₁ to C ₂₀ aliphatic, alicyclic or aromatic structure.

In the meantime, since Z is already mentioned in the description of Formula 2, it is omitted.

Specifically, a thermally reversible elastomer having excellent abrasion resistance and mechanical properties and capable of reprocessing is prepared by using the elastic rubber, monomer, and nanosilica hybrid as described above. Specifically, a thermally reversible elastomer having a 5-necked separable flask equipped with a stirrer, a condenser, And then the mixture was stirred at a speed of 100 to 300 rpm while the temperature was raised to 60 to 100 ° C with nitrogen, and the resin was completely dissolved. Then, the acrylic monomer to be grafted was added and stirred for about 30 minutes Mix well. Subsequently, an azo-based initiator such as peroxide-based or dialkyl peroxide such as dialkyl peroxide or tertiary butyl hydroperoxide, or 2,2'-azobis (isobutyronitrile) or 1,1'-azobis (cyclohexanecarbonitrile) And reacting the mixture at a temperature of 60 to 100 ° C for 4 to 10 hours while introducing nitrogen to prepare an elastomer grafted with a reactive monomer containing an acid group. A silica hybrid compound is added and the silica hybrid is combined with the silica hybrid compound to form an onium salt (reaction at room temperature) or an amide structure (reaction at 80 to 120 ° C) at room temperature or at a temperature of 80 to 120 ° C for 2 to 6 hours (See Reaction Scheme 1), the thus synthesized compound is separated and purified by dissolving in an acetone-soluble portion and a non-soluble portion to obtain a pure elastomer from which unreacted materials have been removed Joe would.

Meanwhile, in the present invention, a filler can be applied as an additive for improving the physical properties of the elastic body, and 20 to 200 parts by weight of the filler can be used as the filler for 100 parts by weight of the elastic body, They are generally used for improving the physical properties of the synthetic resin composition and therefore are not a feature of the present invention. If necessary, additives such as a stabilizer such as a heat stabilizer, an anti-aging agent, and an ultraviolet absorber and a plasticizer may be used, and 0.5 to 2 parts by weight may be used.

Hereinafter, the structure of the present invention will be described in detail with reference to the following Production Examples, Examples and Comparative Examples. However, the constitution of the present invention is not necessarily limited to the following description.

1. Preparation of Nanosilica Hybrid Compounds

(Production Example 1)

44 g of isophorone diisocyanate and 70 g of bis (trimethoxysilylpropyl) amine were reacted at 50 DEG C at a rate of 150 rpm for 2 hours to prepare a silane compound having an isocyanate group at the terminal.

28 g of 2-hydroxyethyl methacrylate and 50 g of methyl ethyl ketone were mixed with the above compound, and then 0.1 g of dibutyl tin dilaurate as a reaction catalyst was added thereto. The mixture was stirred in an oil bath at 50 ° C under a nitrogen atmosphere for 6 hours to obtain an Silane compound. To 192 g of the compound, 100 g of tetramethoxysilane, 50 g of 3-methacryloxypropyltrimethoxysilane and 10 g of 1N hydrochloric acid aqueous solution were added and stirred at room temperature for 24 hours to obtain a nano-silica hybrid compound.

2. Preparation of Thermo-reversible Elastomers

(Example 1)

100 parts by weight of an ethylene-propylene-diene copolymer (EPDM, KEP-570, KKPC) and 900 parts by weight of toluene were placed in a five-necked separable flask equipped with a stirrer, a condenser and a nitrogen gas injector. And the mixture was stirred at a speed of 150 rpm to completely dissolve the resin. One part by weight of the methacrylic acid monomer was added to the dissolved EPDM, followed by stirring for about 30 minutes. Then, 1 part by weight of benzoyl peroxide was added as an initiator, and the mixture was allowed to react for 6 hours while introducing nitrogen at a temperature of 80 DEG C to prepare an EPDM elastomer grafted with an acrylic monomer containing an acid group. After the temperature of the reaction mixture was lowered to room temperature, 30 parts by weight of the organic and inorganic nanosilica hybrid compound at the amine terminal end of Preparation Example 1 was added and reacted at room temperature for 3 hours to prepare an elastomer in the form of a salt- Respectively. The synthesized compound was separated and purified by dissolving in an acetone-soluble portion and a non-soluble portion to prepare a pure elastomer from which unreacted material was removed.

0.6 parts by weight of S-1076 (Songwon Chemical Co.) as an antioxidant was added to 100 parts by weight of the elastomer prepared above, and the film was subjected to a lowering operation at 160 DEG C for 10 minutes and then pressed at 150 DEG C for 10 minutes The mechanical properties were evaluated, and the reworkability was evaluated by repeatedly evaluating the properties of the specimen after the evaluation of physical properties, and then measuring the physical properties after the film was manufactured.

(Example 2)

100 parts by weight of an ethylene-propylene-diene copolymer (EPDM, KEP-570, KKPC) and 900 parts by weight of toluene were used in Example 1, 20 parts by weight of a monomer and 100 parts by weight of a nanosilica hybrid compound , An elastomer was prepared in the same manner as in Example 1, and evaluation specimens were prepared to evaluate mechanical properties and reworkability.

(Comparative Example 1)

0.6 parts by weight of an antioxidant, S-1076, was added to 100 parts by weight of an ungrafted ethylene-propylene-diene copolymer (KEP-570, KKPC) For 10 minutes to evaluate the mechanical properties. After the evaluation of the physical properties, the specimens were re-lowered to measure the physical properties after the film was formed, and the reworkability was evaluated.

(Comparative Example 2)

1 part by weight of sulfur (crosslinking agent), which is an antioxidant, 1.5 parts by weight of bis (2-benzothiazole) disulfide as a vulcanization accelerator, 100 parts by weight of tetramethylthiourea (KEP- 1 part by weight of uream monosulfide and 0.6 part by weight of S-1076 were added and subjected to a lowering operation on a roll at a temperature of 160 占 폚 and then pressed at 200 占 폚 for 10 minutes to prepare a film crosslinked with sulfur to evaluate the mechanical properties, After the evaluation, the specimen was again lowered to measure the physical properties after the film was formed, and the reworkability was evaluated repeatedly.

(Comparative Example 3)

100 parts by weight of an ethylene-propylene-diene copolymer (EPDM, KEP-570, KKPC) and 900 parts by weight of toluene were placed in a five-necked separable flask equipped with a stirrer, a condenser and a nitrogen gas injector. And the mixture was stirred at a speed of 150 rpm to completely dissolve the resin. Ten parts by weight of the methacrylic acid monomer was added to the dissolved EPDM, followed by stirring for about 30 minutes. Then, 1 part by weight of benzoyl peroxide was added as an initiator, and the mixture was allowed to react for 6 hours while introducing nitrogen at a temperature of 80 DEG C to prepare an EPDM elastomer grafted with an acrylic monomer containing an acid group. The synthesized compound was separated into acetone-soluble portion and non-soluble portion and purified to prepare a pure elastomer from which unreacted material was removed. Then, 0.6 parts by weight of an antioxidant, S-1076 (Songwon Chemical Co., Ltd.) was added, and evaluation specimens were prepared in the same manner as in Example 1 to evaluate mechanical properties and reworkability.

(Comparative Example 4)

An ethylene-propylene-diene copolymer grafted with methacrylic acid was synthesized in the same manner as in Example 1, and then the temperature of the reaction mixture was lowered to room temperature. Thereafter, a solution of nano-silica Aerosil 300, Degussa), and the mixture was stirred at room temperature for 3 hours to prepare an elastomer blended with nanosilica. The thus synthesized compound was separated into acetone-soluble portions and non-soluble portions, and purified to prepare pure elastomers from which unreacted materials were removed. Then, 0.6 parts by weight of an antioxidant, S-1076 (Songwon Chemical Co., Ltd.) was added, and evaluation specimens were prepared in the same manner as in Example 1 to evaluate mechanical properties and reworkability.

(Comparative Example 5)

An ethylene-propylene-diene copolymer grafted with methacrylic acid was synthesized in the same manner as in Example 1, and then the temperature of the reactant was lowered to room temperature. Then, in place of the organic and inorganic nanosilica hybrid compound at the terminal of the amine group, (MEK-ST, Nissan chemical) were added and stirred at room temperature for 3 hours to prepare an elastomer blended with the nanosilica. The thus synthesized compound was separated into acetone-soluble portions and non-soluble portions, and purified to prepare pure elastomers from which unreacted materials were removed. Then, 0.6 parts by weight of an antioxidant, S-1076 (Songwon Chemical Co., Ltd.) was added, and evaluation specimens were prepared in the same manner as in Example 1 to evaluate mechanical properties and reworkability.

3. Identification of silica hybrid-bonded elastomers

The compound of Preparation Example 1 was analyzed by infrared spectroscopy (FT-IR spectrometers) to confirm the structure of the elastomer to which the nano-silica hybrid compound was bonded. The results are shown in FIG. 1 and the following.

- Example 1,2 < RTI ID =

^{3400cm -1 (OH stretch of SiOH)} , 1718cm -1 (C = O stretch of 3-methacryloxypropyltrimethoxysilane), 1636,1561cm -1 (asymmetric stretching vibration of CO 2 -, peak by caboxylic acid amine salt), 1080 ~ 1150cm ^-1 (SiO ₂ stretch, peak generated by hybrid nanosilica)

4. Evaluation of the production of thermally reversible elastomers

The thermally reversible elastomers according to the above Examples and Comparative Examples were evaluated according to the following test methods, and the results are shown in Table 1 below.

(1) Hardness

The hardness was measured using a type A durometer according to ASTM D2240. The measurement was made at least ten times at arbitrary points on the specimen and the average value was used.

(2) Tensile strength & Elongation

The obtained elastic body was made to have a thickness of about 5 mm, and then a test piece was prepared with a B type cutter according to KS M 6518, and tensile strength and elongation were measured. At this time, five test pieces were used in the same test.

(3) abrasion resistance

In order to measure the abrasion resistance of the test specimens, NBS abrasion test was carried out by the following formula. After five specimens were tested, the maximum and minimum values were averaged to determine the wear resistance test value.

division
Example Comparative Example One 2 One 2 3 4 5

Mechanical properties

Hardness
(A type) 63 67 36 53 55 62 61 The tensile strength
(kgf / cm ² ) 134 155 15 54 73 108 119 Elongation (%) 800 770 1200 600 780 750 770 300% modulus 41 50 7 25 34 38 40 Abrasion
(NBS)% 85 94 20 80 35 39 46 Remanufacture ^{Note 1)} ○ ○ ○ × △ △ △ Note 1)
○: Excellent reworkability
: Reduced physical properties to less than 70% by reprocessing
X: No remodeling

As shown in Table 1, the present invention shows dissolution at high temperature and re-assembly at low temperature to exhibit superior abrasion resistance and mechanical properties over conventional elastomers crosslinked with sulfur or peroxide, As it can be reworked, it is not only environmentally friendly but also has excellent abrasion resistance and mechanical properties, so that it can be replaced with a material of a product using a conventional crosslinked elastomer such as automobile, shipbuilding, and building materials.

As described above, the heat-reversible elastomer composition excellent in abrasion resistance and mechanical properties according to the present invention and capable of reprocessing has been confirmed to be superior in the above-mentioned embodiments, and those skilled in the art will appreciate that the following patent claims It will be understood that various modifications and alterations may be made therein without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (5)

An inorganic or organic nanosilica hybrid compound having an amine group end represented by the following general formula (2) is reacted with an elastomer grafted with a reactive monomer having an acid group represented by the following general formula (1), and a thermally reversible elastomer .

(Formula 1)

In Formula 1,
R is a C2 to C10 hydrocarbon derivative containing a double bond of CH ₂ = CH-, CH ₃ -CH = CH-, HOOC-CH = CH- or HOOC = CH- and contains a carboxyl group in the molecule

(2)

In Formula 2,
Z is

And is a silica compound having a Si-O-Si bond structure,
Y is an element containing a non-covalent electron pair selected from N, O or S,
R ^{1 is a} C ₁ to C ₁₂ aliphatic, alicyclic or aromatic hydrocarbon derivative,
R ^{2 is a} C ₂ to C ₁₈ aliphatic hydrocarbon derivative, a C ₄ to C ₁₅ alicyclic hydrocarbon derivative or a C ₆ to C ₁₅ aromatic hydrocarbon derivative,
R ³ is a hydrocarbon derivative having a C ₁ to C ₂₀ aliphatic, alicyclic or aromatic structure.
The method according to claim 1,
The elastomer in which the reactive monomer having an acid group is grafted,
Characterized in that 1 to 20 parts by weight of a monomer containing an acid group is added to 100 parts by weight of an elastic rubber put into an organic solvent to perform a graft reaction.
3. The method of claim 2,
Characterized in that 30 to 100 parts by weight of a nanosilica hybrid compound is added to 100 parts by weight of an elastic rubber obtained by grafting a reactive monomer having an acidic group and then the reactive monomer is reacted to react the thermosensitive elastomer with excellent abrasion resistance.
4. The method according to any one of claims 2 to 3,
The above-
Characterized in that they are used alone or in combination of two or more kinds selected from among butadiene rubber, isoprene rubber, styrene-butadiene rubber, nitrile rubber, chloroprene rubber, ethylene-propylene rubber, ethylene- This excellent, reworkable thermo-reversible elastomer.
1) a step of preparing an elastomer grafted with a reactive monomer having an acid group represented by the general formula (1) of claim 1;
2) reacting the organic and inorganic nanosilica hybrid compound represented by the formula (2) of claim 1 with an amine group terminal;
Wherein the thermally reversible elastomer is manufactured through the steps of:

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